A composite pollen-based stratotype for inter-regional evaluation of climatic events in New Zealand over the past 30,000 years (NZ-INTIMATE project)

NASA Astrophysics Data System (ADS)

Barrell, David J. A.; Almond, Peter C.; Vandergoes, Marcus J.; Lowe, David J.; Newnham, Rewi M.

2013-08-01

Our review of paleoclimate information for New Zealand pertaining to the past 30,000 years has identified a general sequence of climatic events, spanning the onset of cold conditions marking the final phase of the Last Glaciation, through to the emergence to full interglacial conditions in the early Holocene. In order to facilitate more detailed assessments of climate variability and any leads or lags in the timing of climate changes across the region, a composite stratotype is proposed for New Zealand. The stratotype is based on terrestrial stratigraphic records and is intended to provide a standard reference for the intercomparison and evaluation of climate proxy records. We nominate a specific stratigraphic type record for each climatic event, using either natural exposure or drill core stratigraphic sections. Type records were selected on the basis of having very good numerical age control and a clear proxy record. In all cases the main proxy of the type record is subfossil pollen. The type record for the period from ca 30 to ca 18 calendar kiloyears BP (cal. ka BP) is designated in lake-bed sediments from a small morainic kettle lake (Galway tarn) in western South Island. The Galway tarn type record spans a period of full glacial conditions (Last Glacial Coldest Period, LGCP) within the Otira Glaciation, and includes three cold stadials separated by two cool interstadials. The type record for the emergence from glacial conditions following the termination of the Last Glaciation (post-Termination amelioration) is in a core of lake sediments from a maar (Pukaki volcanic crater) in Auckland, northern North Island, and spans from ca 18 to 15.64 ± 0.41 cal. ka BP. The type record for the Lateglacial period is an exposure of interbedded peat and mud at montane Kaipo bog, eastern North Island. In this high-resolution type record, an initial mild period was succeeded at 13.74 ± 0.13 cal. ka BP by a cooler period, which after 12.55 ± 0.14 cal. ka BP gave way to a progressive ascent to full interglacial conditions that were achieved by 11.88 ± 0.18 cal. ka BP. Although a type section is not formally designated for the Holocene Interglacial (11.88 ± 0.18 cal. ka BP to the present day), the sedimentary record of Lake Maratoto on the Waikato lowlands, northwestern North Island, is identified as a prospective type section pending the integration and updating of existing stratigraphic and proxy datasets, and age models. The type records are interconnected by one or more dated tephra layers, the ages of which are derived from Bayesian depositional modelling and OxCal-based calibrations using the IntCal09 dataset. Along with the type sections and the Lake Maratoto record, important, well-dated terrestrial reference records are provided for each climate event. Climate proxies from these reference records include pollen flora, stable isotopes from speleothems, beetle and chironomid fauna, and glacier moraines. The regional composite stratotype provides a benchmark against which to compare other records and proxies. Based on the composite stratotype, we provide an updated climate event stratigraphic classification for the New Zealand region. The stratotype and event classification are not intended to act as definitive statements of paleoclimate history for the New Zealand region, but rather provide a firm baseline against which to compare other records including those from the marine realm.

Sporo-pollen assemblage and paleoclimate events in shelf area of the southern Yellow Sea since 15 ka B. P.

NASA Astrophysics Data System (ADS)

Meng, Guanglan; Han, Yousong; Wang, Shaoqing; Wang, Zhenyan

2004-03-01

Based on the authors’ 1986 to 1994 sporo-pollen assemblage analysis in the southern Yellow Sea area, data from 3 main cores were studied in combination with14C, palaeomagnetic and thermoluminescence data. The evolution of the paleoclimate environments in the southern Yellow Sea since 15ka B. P. was revealed that, in deglaciation of the last glacial period, the climate of late glaciation transformed into that of postglaciation, accompanied by a series of violent climate fluctuations. These evolution events happened in a global climate background and related to the geographic changes in eastern China. We distinguished three short-term cooling events and two warming events. Among them, the sporo-pollen assemblage of subzone A1 showed some cold climate features indicating that a cooling event occurred at about 15-14ka. B. P. in early deglaciation. This subzone corresponds to the Oldest Dryas. In subzone A3, many drought-enduring herbal pollens and some few pollens of cold-resistant Picea, Abies, etc. were found, which indicated that a cooling event, with cold and arid climate, occurred at about 12-11ka. B. P. in late deglaciation. This subzone corresponds to the Younger Dryas. The sporo-pollen assemblage of zone B showed warm and arid climate features in postglaciation. Although the assemblage of subzone B2 indicated a cold and arid climate environment, the development of flora in subzone B2 climate was less cold than that in A3. Subzone B2 indicated a cooling event which occurred at about 9ka B. P. in early olocene. Subzone A2, with some distinct differences from subzone A1 and A3, indicated a warming event which occurred at 14-13ka. B.P. and should correspond to a warming fluctuation. The sporo-pollen assemblage of zone C showed features of warn-moist flora and climate, and indicated a warming event which universally occurred along the coast of eastern China at 8-3 ka B. P. in middle Holocene, and its duration was longer than that of any climate events mentioned above. This period was climatic optimum and belonged to an altithermal period in postglaciation.

Sedimentary evidence of landscape and climate history since the end of MIS 3 in the Krkonoše Mountains, Czech Republic

NASA Astrophysics Data System (ADS)

Engel, Zbyněk; Nývlt, Daniel; Křížek, Marek; Treml, Václav; Jankovská, Vlasta; Lisá, Lenka

2010-04-01

A sedimentary core recovered from the cirque basin of Labský důl valley (1039 m a.s.l.) in the Krkonoše Mountains reflects the environmental history for approximately the last 30,000 years. Analyses of magnetic susceptibility, carbon content, pollen assemblages and macrofossil data in a 15 m thick sediment sequence provide the first continuous record of Lateglacial and Holocene vegetation history in Sudetes region of the Czech Republic. The succession of sedimentary units in the lower part of the core suggests that the cirque was ice-free before the onset of the last glaciation at the beginning of marine isotope stage 2. Highly variable climate prevailed during this period with cold conditions culminating about 18 cal ka BP. Cold climates persisted until the Lateglacial period, evidenced by an identified warming and subsequent cooling event correlated with the Younger Dryas period. Sparse, treeless vegetation dominated in the catchment area at that time. The sequence of interrupted thinly laminated silts reflects the retreat and temporary readvance of a local glacier in the cirque during 12.5-10.8 cal ka BP. Subsequently, the alpine treeline ecotone gradually shifted above the cirque floor. Palaeoclimatic conditions in the early Holocene fluctuated strongly, whereas since 5.1 cal ka BP conditions have been more stable. Pollen-based climate reconstructions suggest significant cooling at around 9.8-9.3, 7.7-7.5 and 4.0-3.3 cal ka BP. Spruce forests have dominated the site since 5.0 cal ka BP when the vegetation became similar to the modern one. Two phases of increased sedimentation were identified within the Holocene culminating about 9.2-7.5 cal ka BP and 5.8-5.5 cal ka BP. Sediment yield was as high as 2.4 mm yr -1 during the period, reflecting environmental changes during the Atlantic/Sub-Boreal transition.

Environmental evolution in the Picos de Europa (Cantabrian Mountains, SW Europe) since the Last Glaciation

NASA Astrophysics Data System (ADS)

Ruiz-Fernández, Jesús; Oliva, Marc; Cruces, Anabela; Lopes, Vera; Freitas, Maria da Conceição; Andrade, César; García-Hernández, Cristina; López-Sáez, José Antonio; Geraldes, Miguel

2016-04-01

The Western Massif of the Picos de Europa (latitude 43° N, longitude 4-5° W) includes some of the highest peaks in the Cantabrian Mountains. This massif was heavily glaciated during the Last Glaciation, though the post-glacial environmental evolution is still poorly understood. Using a complementary geomorphological and sedimentological approach, we have reconstructed the environmental events occurred in this massif since the last Pleistocene glaciation. The geomorphological distribution of glacial landforms suggests the occurrence of four main glacial stages: maximum glacial advance, glacial expansion after the maximum advance, Late Glacial and Little Ice Age. Moreover, a 5.4-m long sedimentary sequence was retrieved from the karstic depression of Belbín providing a continuous record of the paleoenvironmental conditions in this area since the Last Glaciation until nowadays. This section suggests that the maximum glacial expansion occurred at a minimum age of 37.2 ka cal BP, significantly prior to the global Last Glacial Maximum. Subsequently, periglacial processes prevailed in the mid lands of the massif until glaciers expanded between 22.5 and 18.7 ka cal BP. Following the melting of the glaciers, a shallow lake appeared in the Belbín depression. Lake sediments do not show evidence of a cold stage during the Late Glacial, when moraine systems formed at higher locations. The terrestrification of this lake started at 8 ka cal BP and the area turned into grassland. At 4.9 ka cal BP the existence of charcoal particles in the sediments of Belbín sequence reveals the onset of human occupation in the massif through the use of fire activity for grazing purposes. Finally, the presence of moraines inside the highest northern cirques shows evidence of the last glacial phase that occurred during the Little Ice Age cold event. Since then, the warming climate has led to the melting of these glaciers and periglacial processes prevail in the high lands of the massif.

Geomorphological and sedimentological evidences in the Western Massif of Picos de Europa since the Last Glaciation

NASA Astrophysics Data System (ADS)

Ruiz-Fernández, Jesus; Oliva, Marc; Cruces, Anabela; Lopes, Vera; Conceição Freitas, Maria; García-Hernández, Cristina; Nieuwendam, Alexandre; López-Sáez, José Antonio; Gallinar, David; Geraldes, Miguel

2015-04-01

The Western Massif of Picos de Europa includes some of the highest peaks of the Cantabrian Mountains. However, the environmental evolution in this massif since the Last Glaciation is still poorly understood. This research provides a new geochronological approach to the sequence of environmental events occurred here since the maximum expansion of glaciers during the last Pleistocene glaciation. The distribution of the glacial landforms suggests four main stages regarding the environmental evolution in the massif: maximum glacial advance, phase of second maximum glacial expansion, Late Glacial and Little Ice Age. A 5.4-m long sedimentological section retrieved from the kame terrace of Belbín, in a mid-height area of the massif, complements the geomorphological interpretation and provides a continuous paleoenvironmental sequence from this area since the Last Glaciation until nowadays. This section suggests that the maximum glacial expansion occurred at a minimum age of 37.2 ka cal BP, significantly prior to the global Last Glacial Maximum. Subsequently, a new glacial expansion occurred around 18.7-22.5 ka cal BP. The melting of the glaciers after this phase generated a shallow lake in the Belbín depression. Lake sediments do not reveal the occurrence of a cold stage during the Late Glacial, whilst, at higher locations, moraine complexes were formed suggesting a glacier readvance. The terrestrification of this lake started at 8 ka cal BP, when Belbín changed to a peaty environment. At 5 ka cal BP human occupation started at the high lands of the massif according to the existence of charcoal particles in the section. The presence of moraines in the highest northern cirques evidences the last phase with formation of small glaciers in the Western Massif of Picos de Europa, corresponding to the Little Ice Age cold event. Since then, the warming climate has led to the melting of these glaciers.

An annually resolved marine proxy record for the 8.2K cold event from the northern North Sea based on bivalve shells

NASA Astrophysics Data System (ADS)

Butler, Paul; Estrella-Martínez, Juan; Scourse, James

2017-04-01

The so-called 8.2K cold event is a rapid cooling of about 6° +/- 2° recorded in the Greenland ice core record and thought to be a consequence of a freshwater pulse from the Laurentide ice sheet which reduced deepwater formation in the North Atlantic. In the Greenland ice cores the event is characterized by a maximum extent of 159 years and a central event lasting for 70 years. As discussed by Thomas et al (QSR, 2007), the low resolution and dating uncertainty of much palaeoclimate data makes it difficult to determine the rates of change and causal sequence that characterise the event at different locations. We present here a bivalve shell chronology based on four shells of Arctica islandica from the northern North Sea which (within radiocarbon uncertainty) is coeval with the 8.2K event recorded in the Greenland ice cores. The years of death of each shell based on radiocarbon analysis and crossmatching are 8094, 8134, 8147, and 8208 yrs BP (where "present" = AD 1950), with an associated radiocarbon uncertainty of +/-80 yrs, and their longevities are 106, 122, 112 and 79 years respectively. The total length of the chronology is 192 years (8286 - 8094 BP +/- 80 yrs). The most noticeable feature of the chronology is an 60-year period of increasing growth which may correspond to a similar period of decreasing ice accumulation in the GRIP (central Greenland) ice core record. We tentatively suggest that this reflects increasing food supply to the benthos as summer stratification is weakened by colder seawater temperatures. Stable isotope analyses (results expected to be available when this abstract is presented), will show changes at annual and seasonal resolution, potentially giving a very detailed insight into the causal factors associated with the 8.2K event and its impact in the northern North Sea.

Centennial and millennial-scale hydroclimate changes in northwestern Patagonia since 16,000 yr BP

NASA Astrophysics Data System (ADS)

Moreno, Patricio I.; Videla, Javiera

2016-10-01

We examine hydroclimate changes at centennial/millennial timescales since 16,000 yr BP in northwestern Patagonia based on the pollen and charcoal record from Lago El Salto, a small closed-basin lake located in the Chilean Lake District (41°38‧48.02″S, 73° 5‧48.42″W). We observe cold/wet conditions between 14,500-16,000 yr BP, followed by further cooling with increased precipitation until 13,000 yr BP, enhanced precipitation seasonality and/or variability between 11,600-13,000 yr BP, and an extended warm-and-dry interval between 7600 and 11,300 yr BP with peak paleofire activity. Colder-and-wetter than present conditions and muted paleofire activity prevail between 5300 and 7600 yr BP, followed by alternating cold/wet and centennial-scale warm/dry phases starting at 5300 yr BP with three conspicuous megadroughts since 2500 yr BP. The most recent megadrought occurred during the Medieval Climate Anomaly. We identify a cold reversal that spans the Antarctic Cold Reversal (ACR) and the Younger Dryas (YD) chrons with stronger-than-present westerly influence during the former and enhanced variability during the latter. These results extend the northern limit of strong cooling and increase in precipitation during the ACR and the southern limit of influence of strong hydrologic variations during the YD in terrestrial environments, suggesting an overlap in the spheres of influence of processes originating from southern and northern polar latitudes. An extended warm southern westerly wind (SWW)-minimum interval is evident between 7600 and 11,300 yr BP, followed by a rapid shift to cool-moist conditions between 5300 and 7600 yr BP brought by a mid-Holocene SWW maximum. Since then we observe centennial-scale hydroclimate variability, which has driven biodiversity and fire-regime shifts of evergreen temperate rainforests.

Differential response of vegetation in Hulun Lake region at the northern margin of Asian summer monsoon to extreme cold events of the last deglaciation

NASA Astrophysics Data System (ADS)

Zhang, Shengrui; Xiao, Jule; Xu, Qinghai; Wen, Ruilin; Fan, Jiawei; Huang, Yun; Yamagata, Hideki

2018-06-01

The response of vegetation to extreme cold events during the last deglaciation is important for assessing the impact of possible extreme climatic events on terrestrial ecosystems under future global warming scenarios. Here, we present a detailed record of the development of regional vegetation in the northern margin of Asian summer monsoon during the last deglaciation (16,500-11,000 cal yr BP) based on a radiocarbon-dated high-resolution pollen record from Hulun Lake, northeast China. The results show that the regional vegetation changed from subalpine meadow-desert steppe to mixed coniferous and deciduous forest-typical steppe during the last deglaciation. However, its responses to the Heinrich event 1 (H1) and the Younger Dryas event (YD) were significantly different: during the H1 event, scattered sparse forest was present in the surrounding mountains, while within the lake catchment the vegetation cover was poor and was dominated by desert steppe. In contrast, during the YD event, deciduous forest developed and the proportion of coniferous forest increased in the mountains, the lake catchment was occupied by typical steppe. We suggest that changes in Northern Hemisphere summer insolation and land surface conditions (ice sheets and sea level) caused temperature and monsoonal precipitation variations that contributed to the contrasting vegetation response during the two cold events. We conclude that under future global warming scenarios, extreme climatic events may cause a deterioration of the ecological environment of the Hulun Lake region, resulting in increased coniferous forest and decreased total forest cover in the surrounding mountains, and a reduction in typical steppe in the lake catchment.

High resolution dating of moraines on Kodiak Island, Alaska links Atlantic and North Pacific climatic changes during the late glacial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mann, D.H.

1992-01-01

Much less is known about the paleoclimate and paleoceanography of the North Pacific than the North Atlantic despite the North Pacific's important role in the global ocean-climate system. Kodiak Island lies in the northwestern Gulf of Alaska astride the eastern end of the Aleutian Low. On southwestern Kodiak Island, coastal bluffs section a series of moraines, kettle ponds, and bogs formed between 15 and 9 ka BP. Distinctive tephras from volcanoes on the Alaska Peninsula provide time-lines within the stratigraphy. Deformation events recorded in sediment stacks from basins within glaciotectonic landforms allows precise dating of glacial events. An ice capmore » occupied the Kodiak archipelago during the last glaciation. Three glacial advances of the southwestern margin of this ice cap occurred after 15 ka BP. At 13.4 ka, piedmont ice lobes formed large push moraines extending into Shelikof Strait during the Low Cape Advance. The less-extensive Tundra Advance culminated between 12 and 11.7 ka BP followed by glacier retreat then readvance to form the prominent Olga Moraine system between 11 and 10 ka BP. The timing of the Tundra and Olga Advances correlates closely with that of the Older and Younger Dryas cold episodes in northwestern Europe suggesting that these climatic oscillations were synchronous throughout the northern hemisphere.« less

Vegetation and climate history in arid western China during MIS2: New insights from pollen and grain-size data of the Balikun Lake, eastern Tien Shan

NASA Astrophysics Data System (ADS)

Zhao, Yongtao; An, Cheng-Bang; Mao, Limi; Zhao, Jiaju; Tang, Lingyu; Zhou, Aifeng; Li, Hu; Dong, Weimiao; Duan, Futao; Chen, Fahu

2015-10-01

Marine Isotope Stage (MIS) 2 is mostly a cold period encompassing the Last Glacial Maximum (LGM), but the regional expression of MIS2 in arid areas of China is not well known. In this paper, we use high-resolution lacustrine pollen and grain-size records from Balikun Lake to infer vegetation, lake evolution, and climate in arid western China during MIS2. Our results suggest that: 1) the regional vegetation around Balikun was mainly dominated by desert and/or desert-steppe, and Balikun Lake was relatively shallow and experienced high aeolian input during MIS2; 2) distinctive runoff from mountain glacial meltwater in the eastern parts of the Balikun basin caused a high relative abundance of Artemisia pollen during the LGM (26.5-19.2 cal kyr BP), while simultaneously the desert areas expanded as indicated by the high abundance of desert shrubs (e.g., Elaeagnaceae, Rhamnaceae, Hippophae). This cold and dry LGM climate triggered a substantial lowering of lake level; 3) an extremely cold and dry climate prevailing from 17.0 to 15.2 cal kyr BP, correlated with Heinrich event 1 (H1), would explain the low vegetation cover found then; and 4) the warm and humid Bølling/Allerød interstadial (BA: ca. 15-ca. 13 cal kyr BP) is clearly recorded in the Balikun region by the development of wetland herb communities (e.g., Poaceae, Cyperaceae, Typha), and the lake level rose due to increased runoff. Our results challenge the traditional view of cold and wet climatic conditions and high lake levels in arid western China during the LGM, and we propose that changes in local temperature modulated by July insolation was an indispensable factor in triggering vegetation evolution in the Balikun region during MIS2.

Climate variability during the Holocene inferred from northeastern Iberian speleothems

NASA Astrophysics Data System (ADS)

Moreno, A.; Bartolomé, M.; Sancho, C.; Belmonte, Á.; Stoll, H.; Cacho, I.; Edwards, R. L.; Hellstrom, J.

2012-04-01

Although the general climate trends during the Holocene in the Iberian Peninsula have been well described after the study of marine and lacustrine records, many questions regarding the timing of some of the events together with the characterization of the higher-frequency climate variability are still poorly understood. New speleothem records from several caves in northeastern Iberia provide data to explore Holocene climate changes. The selected caves are located in a latitudinal transect from the Pyrenees to the Iberian Range and placed at different altitude. Two of them, 5 de Agosto and Pot au Feu, belong to the same karstic complex in Cotiella massif (Central Pyrenees, 1600 m asl). Seso Cave, also in the Central Pyrenees but at 781 m of altitude, and Molinos cave, a cavity very rich in speleothems located at 1040 m in the Iberian Range, complete the transect. Although in all the caves precipitation coming from Atlantic fronts dominates over the year, a significant Mediterranean influence, specially in summer months, is identified after rainfall monitoring. Speleothem formation during the Holocene occurred at a very low pace in 5 de Agosto cave (80yrs/mm) and increased dramatically at low-altitude caves and during particular periods proved to be wetter (eg. Early Holocene in Molinos cave, less than 10yr/mm). In Seso and Pot au Feu caves, up to seven studied speleothems only grew during short climatic events such as the Iron Cold Period (3000-2500 cal yr BP) or the Little Ice Age (1300-1850 yr AD) that, although cold, were particularly humid periods in northeastern Spain. First stable isotope results highlight the importance of comparing speleothems with similar growing rates and from the same cave to extract climate information and discard other influences. From the integration of four stalagmites from Molinos cave covering since the Holocene onset to 2000 cal yrs BP, the Early Holocene (11.7-8.5 ka BP) with d13C values between -11 and - 9‰ appears as the wetter interval. The highest isotopic values are reached during Middle Holocene (8.5-5.5 ka BP) while there is a tendency towards more negative values during Late Holocene (last 5000 yrs). The range of d18O values is low (about 2‰) but still lighter values during Early Holocene and heavier afterwards are well marked. Shorter events characterized by more negative d13C values are observed at 4 ka, 6 ka, 7.5 ka, 8.2, 8.7, 9.2, 10.3 ka and interpreted as cold but probably wetter periods with denser vegetation cover and soil development over the cave. However, changes in the source of precipitation (Atlantic vs Mediterranean) or the influence of fresh-water outbursts in North Atlantic can not be neglected.

Late Quaternary palaeolakes, rivers, and wetlands on the Bolivian Altiplano and their palaeoclimatic implications

NASA Astrophysics Data System (ADS)

Rigsby, Catherine A.; Platt Bradbury, J.; Baker, Paul A.; Rollins, Stephanie M.; Warren, Michelle R.

2005-10-01

Drill cores of sediments from the Rio Desaguadero valley, Bolivia, provide new information about the climate of tropical South America over the past 50 000 years. The modern Rio Desaguadero is fed by Lake Titicaca overflow (and by local tributaries) in the wetter northern Altiplano and discharges into Lake Poopo in the more arid central Altiplano. During the late Quaternary the Rio Desaguadero valley was the site of several generations of palaeolakes and wetlands that formed during periods of increased precipitation and local runoff, augmented by increased overflow from Lake Titicaca. Sediments recovered by drilling in eight localities along the 390-km long valley of the Rio Desaguadero yield a regional history of lacustrine sedimentation and effective precipitation. Lacustrine strata in the drill cores record 12 distinct wet periods in the past 50 000 years. Four of these wet periods resulted in the formation of major palaeolakes in the Rio Desaguadero valley: during the last glacial maximum from before 20 000 to 16 000 cal. yr BP, during the late glacial from about 14 000 to 12 000 cal. yr BP, in the early Holocene from about 10 000 to 7900 cal. yr BP, and in the late Holocene from 4500 cal. yrBP to present. The period that appears to have been most arid was between 7900 and 4500cal.yrBP. The Altiplano wet periods were generally synchronous with North Atlantic cold events (respectively, the last glacial maximum, the Younger Dryas, the 8200cal.yrBP event, and the Neoglacial) implying a relationship between past precipitation variability in tropical South America and North Atlantic sea-surface temperature.

Preliminary Cosmogenic Surface Exposure Ages on Laurentide Ice-sheet Retreat and Opening of the Eastern Lake Agassiz Outlets

NASA Astrophysics Data System (ADS)

Leydet, D.; Carlson, A. E.; Sinclair, G.; Teller, J. T.; Breckenridge, A. J.; Caffee, M. W.; Barth, A. M.

2015-12-01

The chronology for the eastern outlets of glacial Lake Agassiz holds important consequences for the cause of Younger Dryas cold event during the last deglaciation. Eastward routing of Lake Agassiz runoff was originally hypothesized to have triggered the Younger Dryas. However, currently the chronology of the eastern outlets is only constrained by minimum-limiting radiocarbon ages that could suggest the eastern outlets were still ice covered at the start of the Younger Dryas at ~12.9 ka BP, requiring a different forcing of this abrupt climate event. Nevertheless, the oldest radiocarbon ages are still consistent with an ice-free eastern outlet at the start of the Younger Dryas. Here we will present preliminary 10-Be cosmogenic surface exposure ages from the North Lake, Flat Rock Lake, glacial Lake Kaministiquia, and Lake Nipigon outlets located near Thunder Bay, Ontario. These ages will date the timing of the deglaciation of the Laurentide ice sheet in the eastern outlet region of glacial Lake Agassiz. This will provide an important constraint for the hypothesized freshwater forcing of the cause of Younger Dryas cold event.

Evidence of resilience to past climate change in Southwest Asia: Early farming communities and the 9.2 and 8.2 ka events

NASA Astrophysics Data System (ADS)

Flohr, Pascal; Fleitmann, Dominik; Matthews, Roger; Matthews, Wendy; Black, Stuart

2016-03-01

Climate change is often cited as a major factor in social change. The so-called 8.2 ka event was one of the most pronounced and abrupt Holocene cold and arid events. The 9.2 ka event was similar, albeit of a smaller magnitude. Both events affected the Northern Hemisphere climate and caused cooling and aridification in Southwest Asia. Yet, the impacts of the 8.2 and 9.2 ka events on early farming communities in this region are not well understood. Current hypotheses for an effect of the 8.2 ka event vary from large-scale site abandonment and migration (including the Neolithisation of Europe) to continuation of occupation and local adaptation, while impacts of the 9.2 ka have not previously been systematically studied. In this paper, we present a thorough assessment of available, quality-checked radiocarbon (14C) dates for sites from Southwest Asia covering the time interval between 9500 and 7500 cal BP, which we interpret in combination with archaeological evidence. In this way, the synchronicity between changes observed in the archaeological record and the rapid climate events is tested. It is shown that there is no evidence for a simultaneous and widespread collapse, large-scale site abandonment, or migration at the time of the events. However, there are indications for local adaptation. We conclude that early farming communities were resilient to the abrupt, severe climate changes at 9250 and 8200 cal BP.

Changes in ventricular function during emotional stress and cold exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiess, M.C.; Moore, R.A.; Dimsdale, J.

1984-01-01

Patients with cardiac disease frequently develop symptoms with emotional stress or cold exposure. To investigate the effects of these stresses in normal subjects, an ambulatory ventricular function monitor (VEST) (previously reported to measure EFs which correlate well with gamma camera measurements) was employed to record sequential 2 minute time activity curves from the left ventricles of 6 healthy men (ages 19-24) during a control period and during a 30 minute stress interview with a psychiatrist. Four of the subjects were also monitored in a cold room (1/sup 0/C) for 20 min. In addition to the left ventricular time-activity curve, heartmore » rate (HR), and BP (cuff) were recorded. All subjects had increases in HR, BP and EF during the stress interview. Cold, however, produced decreases in HR and EF and an increase in BP. The results (mean +- SD) are tabulated. End-systolic and end-diastolic counts and hence volume decreased during the interview and increased during cold exposure. The results suggest that (1) ambulatory changes in ventricular function can be measured with the VEST, and (2) significant changes in cardiovascular physiology are seen in normal subjects during a stress interview and exposure to cold.« less

Seasonal dynamics of bacterial biomass and production in a coastal arctic ecosystem: Franklin Bay, western Canadian Arctic

NASA Astrophysics Data System (ADS)

Garneau, Marie-Ã. Ve; Roy, SéBastien; Lovejoy, Connie; Gratton, Yves; Vincent, Warwick F.

2008-07-01

The Canadian Arctic Shelf Exchange Study (CASES) included the overwintering deployment of a research platform in Franklin Bay (70°N, 126°W) and provided a unique seasonal record of bacterial dynamics in a coastal region of the Arctic Ocean. Our objectives were (1) to relate seasonal bacterial abundance (BA) and production (BP) to physico-chemical characteristics and (2) to quantify the annual bacterial carbon flux. BA was estimated by epifluorescence microscopy and BP was estimated from 3H-leucine and 3H-thymidine assays. Mean BA values for the water column ranged from 1.0 (December) to 6.8 × 105 cells mL-1 (July). Integral BP varied from 1 (February) to 80 mg C m-2 d-1 (July). During winter-spring, BP was uncorrelated with chlorophyll a (Chl a), but these variables were significantly correlated during summer-autumn (rs = 0.68, p < 0.001, N = 38), suggesting that BP was subject to bottom-up control by carbon supply. Integrated BP data showed three distinct periods: fall-winter, late winter-late spring, and summer. A baseline level of BB and BP was maintained throughout late winter-late spring despite the persistent cold and darkness, with irregular fluctuations that may be related to hydrodynamic events. During this period, BP rates were correlated with colored dissolved organic matter (CDOM) but not Chl a (rs BP.CDOM∣Chl a = 0.20, p < 0.05, N = 176). Annual BP was estimated as 6 g C m-2 a-1, implying a total BP of 4.8 × 1010 g C a-1 for the Franklin Bay region. These results show that bacterial processes continue throughout all seasons and make a large contribution to the total biological carbon flux in this coastal arctic ecosystem.

The abrupt climate change near 4,400 yr BP on the cultural transition in Yuchisi, China and its global linkage.

PubMed

Wang, Jianjun; Sun, Liguang; Chen, Liqi; Xu, Libin; Wang, Yuhong; Wang, Xinming

2016-06-10

Extreme climatic events have profound impacts on human society. Here we present the results of a study of organic biomarkers within a sedimentary section at the archaeological site of Yuchisi, eastern China, in order to reconstruct climatic variability during the Dawenkou (5,050-4,400 yr BP) and Longshan (4,400-4,000 yr BP) cultures. At ~4,400 yr BP, within the cultural transition horizon, abrupt changes in biomarkers, such as the fatty acid ratio C18:2/C18:0, 2C31/(C27 + C29), n-C18-ol and n-C30-ol, indicate the occurrence of local climate changes over the course of a few decades. These changes occurred during the transition from the Holocene warm period to a subsequent cold period which lasted for the following 600 years. This climatic shift has been recorded at numerous sites worldwide, and it is likely to have been the main cause of the widespread collapse of many isolated cultures at that time. The palaeoclimatic and archaeological data from the Yuchisi sediments may provide new insights into the relationship between climate change and prehistoric cultural transitions.

The abrupt climate change near 4,400 yr BP on the cultural transition in Yuchisi, China and its global linkage

PubMed Central

Wang, Jianjun; Sun, Liguang; Chen, Liqi; Xu, Libin; Wang, Yuhong; Wang, Xinming

2016-01-01

Extreme climatic events have profound impacts on human society. Here we present the results of a study of organic biomarkers within a sedimentary section at the archaeological site of Yuchisi, eastern China, in order to reconstruct climatic variability during the Dawenkou (5,050–4,400 yr BP) and Longshan (4,400–4,000 yr BP) cultures. At ~4,400 yr BP, within the cultural transition horizon, abrupt changes in biomarkers, such as the fatty acid ratio C18:2/C18:0, 2C31/(C27 + C29), n-C18-ol and n-C30-ol, indicate the occurrence of local climate changes over the course of a few decades. These changes occurred during the transition from the Holocene warm period to a subsequent cold period which lasted for the following 600 years. This climatic shift has been recorded at numerous sites worldwide, and it is likely to have been the main cause of the widespread collapse of many isolated cultures at that time. The palaeoclimatic and archaeological data from the Yuchisi sediments may provide new insights into the relationship between climate change and prehistoric cultural transitions. PMID:27283832

Holocene Asian monsoon evolution revealed by a pollen record from an alpine lake on the southeastern margin of the Qinghai-Tibetan Plateau, China

NASA Astrophysics Data System (ADS)

Zhang, Enlou; Wang, Yongbo; Sun, Weiwei; Shen, Ji

2016-02-01

We present the results of pollen analyses from a 1105 cm long sediment core from Wuxu Lake in southwestern China, which depict the variations of the East Asian winter monsoon (EAWM) and the Indian summer monsoon (ISM) during the last 12.3 ka. During the period of 12.3 to 11.3 cal ka BP, the dominance of Betula forest and open alpine shrub and meadow around Wuxu Lake indicates a climate with relatively cold winters and dry summers, corresponding to the Younger Dryas event. Between 11.3 and 10.4 cal ka BP, further expansion of Betula forest and the retreat of alpine shrubs and meadows reflect a greater seasonality with cold winters and gradually increasing summer precipitation. From 10.4 to 4.9 cal ka BP, the dense forest understory, together with the gradual decrease in Betula forest and increase in Tsuga forest, suggest that the winters became warmer and summer precipitation was at a maximum, corresponding to the Holocene climatic optimum. Between 4.9 and 2.6 cal ka BP, Tsuga forest and alpine shrubs and meadows expanded significantly, reflecting relatively warm winters and decreased summer precipitation. Since 2.6 cal ka BP, reforestation around Wuxu Lake indicates a renewed humid period in the late Holocene; however, the vegetation in the catchment may also have been affected by grazing activity during this period. The results of our study are generally consistent with previous findings; however, the timing and duration of the Holocene climatic optimum from different records are inconsistent, reflecting real contrast in local rainfall response to the ISM. Overall, the EAWM is broadly in-phase with the ISM on the orbital timescale, and both monsoons exhibit a trend of decreasing strength from the early to late Holocene, reflecting the interplay of solar insolation receipt between the winter and summer seasons and El Niño-Southern Oscillation strength in the tropical Pacific.

Holocene Asian monsoon evolution revealed by a pollen record from an alpine lake on the southeastern margin of the Qinghai-Tibetan Plateau, China

NASA Astrophysics Data System (ADS)

Zhang, E.; Wang, Y.; Sun, W.; Shen, J.

2015-10-01

We present the results of pollen analyses from a 1105-cm-long sediment core from Wuxu Lake in southwestern China, which depict the variations of the East Asian winter monsoon (EAWM) and the Indian summer monsoon (ISM) during the last 12.3 ka. During the period of 12.3 to 11.3 cal ka BP, the dominance of Betula forest and open alpine shrub and meadow around Wuxu Lake indicates a climate with relatively cold winters and dry summers, corresponding to the Younger Dryas event. Between 11.3 and 10.4 cal ka BP, further expansion of Betula forest and the retreat of alpine shrubs and meadows reflect a greater seasonality with cold winters and gradually increasing summer precipitation. From 10.4 to 4.9 cal ka BP, the dense forest understory, together with the gradual decrease in Betula forest and increase in Tsuga forest, suggest that the winters became warmer and summer precipitation was at a maximum, corresponding to the Holocene climatic optimum. Between 4.9 and 2.6 cal ka BP, Tsuga forest and alpine shrubs and meadows expanded significantly, reflecting relatively warm winters and decreased summer precipitation. Since 2.6 cal ka BP, reforestation around Wuxu Lake indicates a renewed strengthening of the ISM in the late Holocene; however, the vegetation in the catchment may also have been affected by grazing activity during this period. The results of our study are generally consistent with previous findings; however, the timing and duration of the Holocene climatic optimum from different records are inconsistent, reflecting real contrast in local rainfall response to the ISM. Overall, the EAWM is broadly in-phase with the ISM on the orbital timescale, and both monsoons exhibit a trend of decreasing strength from the early to late Holocene, reflecting the interplay of solar insolation receipt between the winter and summer seasons and El Niño Southern Oscillation strength in the tropical Pacific.

Late Pleistocene - Holocene surface processes and landscape evolution in the central Swiss Alps

NASA Astrophysics Data System (ADS)

Boxleitner, Max; Musso, Alessandra; Waroszewski, Jarosław; Malkiewicz, Małgorzata; Maisch, Max; Dahms, Dennis; Brandová, Dagmar; Christl, Marcus; de Castro Portes, Raquel; Egli, Markus

2017-10-01

The European Alps are a geomorphologically active region and experience a number of gravity-driven hillslope processes. Soil and landscape formation in the Alps has consequently undergone several minor and major traceable changes of developmental trajectories during the Holocene. Soil development is hypothesised to be often non-linear with time and characterised by stages of progressive and regressive evolution caused by upbuilding (formation, profile deepening) and erosion (profile shallowing). Several cold and warm climate phases are identified during the Holocene but it is largely unknown which effects these might have had on slope processes. By using datable moraines (10Be) and mires (14C), we have constructed a temporal framework for these processes. Using the geochemical imprint of mires in the Alpine setting of the Göschener-valley of the Central Swiss Alps, we reconstructed general (mostly erosional) landscape processes for the last ca. 10 ka. As this is the type locality for the Göschener cold phase, we assumed that this phase (Göschener cold phase I and II 1.5 and 2.5 ka BP) should have left easily recognizable traits. After deglaciation (11-12 ka BP), soil evolution was progressive. Beginning around 8 ka BP, we detect a distinct increase in erosion here, together with a vegetation change (towards tundra vegetation) and the highest measured rates of carbon sequestration. Other phases of high geomorphic activity were recognised ca. 5-6 ka BP, 4 ka BP and, to a lesser extent, 1-3 ka ago. The cold phase at 5-6 ka BP corresponds to a less distinct change in vegetation and lessened erosion. Human impact is increasingly obvious since about 2.4 ka BP which overlaps with the Göschener cold phase. Nonetheless, erosion processes were not extraordinarily high during this period and a climate effect cannot be distinguished. We detect evidence of increasing human disturbance (regressive soil evolution) for about the last 1 ka. We also detect an increase in dust flux during the last ca. 4-5 ka, presumably due to the landscape change(s) in the Sahara during this time.

Impact of climate variability on terrestrial environment in Western Europe between 45 and 9 kyr cal. BP: vegetation dynamics recorded by the Bergsee Lake (Black Forest, Germany).

NASA Astrophysics Data System (ADS)

Duprat-Oualid, Fanny; Begeot, Carole; Rius, Damien; Millet, Laurent; Magny, Michel

2016-04-01

Between 9 and 45 kyr cal. BP, two great transitions lead the global climate system to evolve from the Last-Glacial period (115-14.7 kyr cal. BP), to two successive warmer periods, the Late-Glacial Interstadial (14.7-11.7 kyr cal. BP) and the Holocene (11.7-0 kyr cal. BP). δ18O variations recorded in Greenland ice cores (GRIP & NGRIP) revealed high frequency climate variability within the Last Glacial. These reference isotopic records highlighted a succession of centennial-to-millennial warm/cold events, the so-called Greenland Interstadials (GI) and Greenland Stadials (GS). The number continental records about the period 14.7-0 kyr cal. BP is substantial. This allowed to understand the vegetation dynamics in response to climate changes this period at the North-Atlantic scale. However, sequences covering the glacial period (beyond 20 kyr cal.BP) remain rare, because of hiatuses mostly due to local glaciers. Therefore, sedimentary continuous records of vegetation dynamics are still needed to better understand climate changes during the Last Glacial in Western Europe (Heiri et al. 2014). Here we present a new high-resolution pollen record from Lake Bergsee (47°34'20''N, 7°56'11''E, 382 m a.s.l). This lake is located south of Black Forest and north of the Alps, beyond the zone of glaciers maximal extension. Therefore it could have recorded the whole last climatic cycle, i.e. 120-0 kyr cal. BP. In 2013, a 29 m long core was extracted from the Bergsee. According to the depth-age model based on 14C AMS dating and the Laacher See Tephra (LST), the record spans continuously at least the last 45 kyrs. The first series of pollen analysis, focused on the 45-9 kyr cal. BP time window, allows us to reconstruct a precise, faithful and continuous vegetation history at the centennial scale. This high temporal resolution enabled to assess the response of vegetation to secular climate events (e.g. GI-4 = 200 yrs). First, our results show that vegetation responded to climate changes at millennial/pluri-millennial scale. The well-known afforestation of the Late-Glacial interstadial and the Holocene (with pine and hazel-dominated forests respectively) are recorded. Our results also reveal a three-phase sequence in the Last-Glacial. The persistence of very cold conditions between 24 and 30 kyr cal. BP favored a drastic steppe grassland. In contrast, trees proportion increased during the two other periods (14.7-24 and 30-45 kyr cal. BP) in correlation with a relative favorable climate. Second, the respons of vegetation to centennial scale climatic events is characterized by the successive rapid establishment of two different landscapes. GS are dominated by steppic taxa (Artemisia, Helianthemum), whereas more or less complete ecological successions Juniperus-Betula-Pinus seem to occur for most GIs when edaphic conditions became more favorable. Therefore, we suggest a global forcing defined by the strong impact of the climate variability on vegetation changes. We also propose the contribution of local characteristics (latitude, topography) which favored flora migration and long distance pollen inputs from refuge areas. Heiri O., Koinig K.A., Spötl C., Barrett S, Brauer A., Drescher-Schneider R., Gaar D., Ivy-Ochs S., Kerschner H., Luetscher M., Moran A., Nicolussi K., Preusser F., Schmidt R., Schoeneich P., Schwörer C., Sprafke T., Terhorst B., Tinner W. -2014- "Palaeoclimate records 60-8 ka in the Austrian and Swiss Alps and their forelands", Quaternary Science Review, 106 : 186-205.

Hunter-Gatherer Responses to the 8.2 Ka Cold Event in the Fennoscandian Arctic

NASA Astrophysics Data System (ADS)

Manninen, M. A.

2014-12-01

Because of a marked influence of warm Atlantic water to primary productivity in the Barents Sea, the marine ecosystem in northernmost Fennoscandia is sensitive to disturbances in the North Atlantic oceanographic system. The 8.2 ka climate event, according to current knowledge, was triggered by a disturbance in the North Atlantic Thermohaline circulation. This suggests concurrent and strong climatic and marine cooling in the area covering the northernmost parts of Finland, Norway, and Sweden during the climate event. In this area ecosystem response to the 8.2 ka event can therefore be expected to have been prominent, which in turn should be reflected in the contemporary human socio-economic systems. A study that employs lithic technological, statistical, and spatial analyses of Late Mesolithic (ca. 8450-6850 cal BP) lithic technology and settlement configuration in the area indicates that lithic technology and settlement patterns were reorganised following the climatic and marine cooling. The studied groups changed their lithic technology as a result of developments that led to increased use of terrestrial resources and an accompanying long-distance coast/inland residential mobility pattern. Besides lithic technological changes and long-distance mobility on land, decreased marine productivity probably also explains the disappearance of semi-subterranean houses from the coast at ca. 8200 cal BP, while their reappearance after ca. 7500 cal BP can be linked to a increased influx of warm salty water into the Barents Sea. The results suggest that in the past a long period of decreased influx of Atlantic water into the Barents Sea has had disastrous consequences for the marine ecosystem. At present the Barents Sea fisheries have notable economic importance and produce, for example, over 90% of the Norwegian Atlantic cod (Gadus morhua) catch.

Equilibrium-line altitude during the Antarctic Cold Reversal at Río Tranquilo glacier (47°S), Central Patagonia

NASA Astrophysics Data System (ADS)

Sagredo, E. A.; Ward, D.; Gonzalez, M. A.; Lowell, T. V.; Kelly, M. A.; Aravena, J. C.

2013-12-01

Documenting the magnitude of former glacial fluctuations is critical for understanding the mechanisms and climate signals underlying these glacial events. Here, we estimate the equilibrium line altitudes (ELA) associated with the most prominent glacial advance occurred during the Last Glacial Termination (T1) at Tranquilo glacier (47°S). Geomorphic evidence suggest that, following the Last Glacial Maximum, several small glaciers, which today occupy the headwalls of Río Tranquilo valley, expanded and coalesced, forming the extended version of the Tranquilo glacier at least three different times. 10Be ages suggest that the most prominent of these glacial advances occurred ~13 kyr BP, at the end of the Antarctic Cold Reversal (ACR). Based on glacial geomorphic mapping and the application of a glaciological model (GC2D), we reconstruct the former glacial surface at Tranquilo glacier and estimate the ELA for this major glacial advance. Preliminary data show that the equilibrium line altitude at Tranquilo glacier during the ACR could have been up to 500 m lower than the present. This study represents the first effort to quantify the ELA during the Antarctic Cold Reversal in Patagonia, and provides a baseline to decipher the climatic signals driving this glacial event.

Paleoecological and climatic implications of stable isotope results from late Pleistocene bone collagen, Ziegeleigrube Coenen, Germany

NASA Astrophysics Data System (ADS)

Wißing, Christoph; Matzerath, Simon; Turner, Elaine; Bocherens, Hervé

2015-07-01

Climatic and ecological conditions during Marine Oxygen Isotope Stage (MIS) 3 are complex and the impact of cold spells on the ecosystems in Central Europe still needs to be investigated thoroughly. Ziegeleigrube Coenen (ZC) is a late Pleistocene MIS 3 locality in the Lower Rhine Embayment of Germany, radiocarbon-dated to > 34 14C ka BP. The site yielded a broad spectrum of mammal species. We investigated the carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) isotope signatures of bone collagen, since these are valuable tools in characterizing ecological niches, environmental conditions and aspects of climate and mobility. By comparison with pre- and post-Last Glacial Maximum (LGM) sites in Central Europe we show that ZC belongs in a cold event of MIS 3 and was climatically more similar to post-LGM sites than to pre-LGM sites. However, the trophic structure resembled that of typical pre-LGM sites in Belgium. This cold event in MIS 3 changed the bottom of the foodweb, but do not seem to have had a direct impact on the occurrence of the mammalian species and their ecological distribution. Apparently the (mega-) faunal community could adapt also to harsher environmental conditions during MIS 3.

Mineral magnetism and other characteristics of sediments from a sub-alpine lake (3080 m a.s.l.) in central east China and their implications on environmental changes for the last 5770 years

NASA Astrophysics Data System (ADS)

Wang, Hongya; Song, Yaqiong; Cheng, Ying; Luo, Yao; Zhang, Cai'na; Gao, Yishen; Qiu, An'an; Deng, Lei; Liu, Hongyan

2016-10-01

A sediment sequence (SQC07) was recovered from Sanqing Chi, a small sub-alpine lake (3080 m a.s.l.) on Taibai (3767 m a.s.l.), the highest mountain in east mainland China (east of 105°). The Mountain is also the highest part and central massif of the Qinling Mountain Range functioning as the boundary between the warm temperate climate zone to the north and sub-tropical climate zone to the south in east China. Soils and debris were also sampled from the catchment of Sanqing Chi. SQC07 was AMS 14C dated. Mineral magnetism was measured for the sediment sequence and catchment samples. Particle-size, TOC and TN analysis were undertaken on SQC07, while pollen analysis was made for the sediment sequence and surface-soil samples. With the mineral magnetism of the catchment materials, the magnetic and other characteristics of SQC07 indicate the environmental changes occurring on the high altitudes of Taibai Mountain during the past 5770 years. Environments were still moderately warm and wet over 5770-5100 cal. yr BP around this sub-alpine lake. Then cold and dry conditions persisted in the period of 5100-4000 cal. yr BP. Local environments began to ameliorate from 4000 cal. yr BP onwards and were thus generally warm and wet over 4000-1200 cal. yr BP. The warmth and wetness culminated in 1200-800 cal. yr BP. During the period of 800-400 cal. yr BP, cold and arid conditions again predominated. Environments have subsequently become warm and humid since ∼400 cal. yr BP. The overall trend of the changes is coincident with what have been identified at several other sites in east mainland China and Taiwan. Presumably, the deterioration over 5100-4000 cal. yr BP marks the termination of the Holocene optimum, corresponds to or encompasses Holocene event 3, while the deterioration occurring in 800-400 cal. yr BP may correspond to LIA cooling. However, they appear to have commenced earlier than the aforementioned sites at relatively low altitudes in east mainland China or even higher altitudes but far southeast in Taiwan. These differences are possibly caused partly by uncertainties and/or errors of chronologies. Nevertheless, they also could be attributed to the spatial variability of East Asian monsoon and/or earlier responses of local landscapes around Sanqing Chi to larger-scale climate-deterioration.

Vegetation changes and timberline fluctuations in the Central Alps as indicators of holocene climatic oscillations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wick, L.; Tinner, W.

Pollen and plant-macrofossil data are presented for two lakes near the timberline in the Italian (Lago Basso, 2250 m) and Swiss Central Alps (Gouille Rion, 2343 m). The reforestation at both sites started at 9700-9500 BP with Pinus cembra, Larix decidua, and Betula. The timberline reached its highest elevation between 8700 and 5000 BP and retreated after 5000 BP, due to a mid-Holocene climatic change and increasing human impact since about 3500 BP (Bronze Age). The expansion of Picea abies at Lago Basso between ca. 7500 and 6200 BP was probably favored by cold phases accompanied by increased oceanicity, whereasmore » in the area of Gouille Rion, where spruce expanded rather late (between 4500 and 3500 BP), human influence equality might have been important. The mass expansion of Alnus viridis between ca. 5000 and 3500 BP probably can be related to both climatic change and human activity at timberline. During the early and middle Holocene a series of timberline fluctuations is recorded as declines in pollen and macrofossil concentrations of the major tree species, and as increases in nonarboreal pollen in the pollen percentage diagram of Gouille Rion. Most of the periods of low timberline can be correlated by radiocarbon dating the climatic changes in the Alps as indicated by glacier advances in combination with palynological records, solifluction, and dendroclimatical data. Lago Basso and Gouille Rion are the only sites in the Alps showing complete palaeobotanical records of cold phases between 10,000 and 2000 BP with very good time control. The altitudinal range of the Holocene treeline fluctuations caused by climate most likely was not more than 100 to 150 m. A possible correlation of a cold period at ca. 7500-6500 BP (Misox oscillation) in the Alps is made with paleoecological data from North American and Scandinavia and a climate signal in the GRIP ice core from central Greenland 8200 yr ago (ca. 7400 yr uncal. BP).« less

Interhemispheric correlation of late pleistocene glacial events.

PubMed

Lowell, T V; Heusser, C J; Andersen, B G; Moreno, P I; Hauser, A; Heusser, L E; Schlüchter, C; Marchant, D R; Denton, G H

1995-09-15

A radiocarbon chronology shows that piedmont glacier lobes in the Chilean Andes achieved maxima during the last glaciation at 13,900 to 14,890, 21,000, 23,060, 26,940, 29,600, and >/=33,500 carbon-14 years before present ((14)C yr B.P.) in a cold and wet Subantarctic Parkland environment. The last glaciation ended with massive collapse of ice lobes close to 14,000(14)C yr B.P., accompanied by an influx of North Patagonian Rain Forest species. In the Southern Alps of New Zealand, additional glacial maxima are registered at 17,720(14)C yr B.P., and at the beginning of the Younger Dryas at 11,050 (14)C yr B. P. These glacial maxima in mid-latitude mountains rimming the South Pacific were coeval with ice-rafting pulses in the North Atlantic Ocean. Furthermore, the last termination began suddenly and simultaneously in both polar hemispheres before the resumption of the modern mode of deep-water production in the Nordic Seas. Such interhemispheric coupling implies a global atmospheric signal rather than regional climatic changes caused by North Atlantic thermohaline switches or Laurentide ice surges.

Effects of weather conditions on emergency ambulance calls for acute coronary syndromes

NASA Astrophysics Data System (ADS)

Vencloviene, Jone; Babarskiene, Ruta; Dobozinskas, Paulius; Siurkaite, Viktorija

2015-08-01

The aim of this study was to evaluate the relationship between weather conditions and daily emergency ambulance calls for acute coronary syndromes (ACS). The study included data on 3631 patients who called the ambulance for chest pain and were admitted to the department of cardiology as patients with ACS. We investigated the effect of daily air temperature ( T), barometric pressure (BP), relative humidity, and wind speed (WS) to detect the risk areas for low and high daily volume (DV) of emergency calls. We used the classification and regression tree method as well as cluster analysis. The clusters were created by applying the k-means cluster algorithm using the standardized daily weather variables. The analysis was performed separately during cold (October-April) and warm (May-September) seasons. During the cold period, the greatest DV was observed on days of low T during the 3-day sequence, on cold and windy days, and on days of low BP and high WS during the 3-day sequence; low DV was associated with high BP and decreased WS on the previous day. During June-September, a lower DV was associated with low BP, windless days, and high BP and low WS during the 3-day sequence. During the warm period, the greatest DV was associated with increased BP and changing WS during the 3-day sequence. These results suggest that daily T, BP, and WS on the day of the ambulance call and on the two previous days may be prognostic variables for the risk of ACS.

Blood pressure reactivity to psychological stress predicts hypertension in the CARDIA study.

PubMed

Matthews, Karen A; Katholi, Charles R; McCreath, Heather; Whooley, Mary A; Williams, David R; Zhu, Sha; Markovitz, Jerry H

2004-07-06

A longstanding but controversial hypothesis is that individuals who exhibit frequent, large increases in blood pressure (BP) during psychological stress are at risk for developing essential hypertension. We tested whether BP changes during psychological stress predict incident hypertension in young adults. We used survival analysis to predict hypertensive status during 13 years of follow-up in a sample of >4100 normotensive black and white men and women (age at entry, 18 to 30 years) enrolled in the CARDIA study. BP responses to 3 psychological challenges--cold pressor, star tracing, and video game tasks--were measured. Hypertensive status was defined as use of antihypertensive medication or measured BP > or =140/90 mm Hg. After adjustment for race, gender, covariates (education, body mass index, age, and resting pressure), and their significant interactions, the larger the BP responses were to each of the 3 tasks, the earlier hypertension occurred (P<0.0001 to <0.01). The systolic BP effect for the cold pressor task was apparent for women and for whites in race- and gender-specific models, whereas the diastolic BP effect for the video game was apparent for men. Young adults who show a large BP response to psychological stress may be at risk for hypertension as they approach midlife.

The impact of MIS-3 climate events at the transition from Neanderthals to modern humans in Europe

NASA Astrophysics Data System (ADS)

Staubwasser, M.; Dragusin, V.; Assonov, S.; Ersek, V.; Hoffmann, D.; Veres, D.; Onac, B. P.

2017-12-01

We report on last glacial stable C and O isotope records from two U-Th dated speleothems from Romania. The southerly record (Ascunsa Cave, South Carpathians) from the Danube region matches the pacing and relative change in amplitude of the Greenland ice temperature record at 30-50 ka BP as well as the abundance of coastal winter sea ice in the Black Sea. The northerly record (Tausoare Cave, East Carpathians) in parts shares the pacing of events with the Greenland or the southern Romanian record, but best matches northern Black Sea summer season temperature change. Heinrich events do not stand out in either record, but the temperature amplitudes of Greenland stadials and Black Sea records are generally reproduced. Based on similarity with the Black Sea we interpret the combined two speleothem records in terms of seasonal temperature change in central Eastern Europe. A climatic influence on the transition from Neanderthals to modern humans has long been suspected. However, the diachronous and spatially complex archaeologic succession across the Middle-Upper Paleolithic (MUPL) in Europe ( 38 - 48 ka) is difficult to reconcile with the millennial-scale pacing of northern hemisphere paleoclimate. Two extreme cold events at 44.0-43.3 recorded and 40.7-39.8 ka in the speleothems bracket the dates of the first known appearance of modern humans - the Aurignacian complex - and the disappearance of Neanderthals from most of Europe. These cold events are coeval with Greenland Stadials GS-12 and GS-10. The speleothem records generally match the paleosol/loess succession from central Europe across the MUPL. The combined record suggests that permafrost advance may have made central Europe uninhabitable at least during winter. The combined paleoclimate and archaeologic records suggest that depopulation-repopulation cycles may have occurred during and after each cold event. Repopulation of central Europe geographically favored the modern human Aurignacians from SE Europe.

Funnel Beaker weather (6200-4900 cal BP) - reconstructed from the palaeolimnological record of synchronously deposited varves in northern Germany

NASA Astrophysics Data System (ADS)

Dreibrodt, Stefan; Zahrer, Jürgen; Brauer, Achim

2013-04-01

Depositional patterns of synchronously deposited varves of Lake Belauer See and Lake Poggensee (northern Germany) were studied on thin sections under the microscope comparatively. Events and trends that occurred synchronously in the lake systems were detected and interpret as limnologic responses to supra-regional extrinsic (climate) drivers. The different thresholds of the compared lake systems implied by different lake size were utilized to infer about weather conditions. For Lake Belauer See microfacies types of sub-recent varves were proved to reflect responses of certain meteorological conditions (e.g. severity of winters). A short weather anomaly at around 5950 cal BP was detected. Cold summers of about 40 successive years (probably with sudden frost events) lead to breaks of the thermal summer stratification and the associated carbonate precipitation. Instead renewed blooms of planctic diatoms occurred. The subsequent interval of the Funnel Beaker Culture seems to have experienced a period with favorable wea¬ther conditions, with warm summers and not extra-ordinary severe winters. Between ca. 5400 and 5340 cal BP an interval with pronounced warm winters is indicated. The favorable weather conditions termina¬ted abruptly at around 5275 cal BP when the weather (in particular summers) became colder. The comparison of the sediment sequences also provides evidence for the asynchronic onset of anthropogenic activity in the catchment areas of the lakes. A significant increase of minerogenic matter (quartz grains) indication soil erosion in the lake catchment started at ca. 3850 cal BC in Lake Poggensee, and at ca. 3500 cal BC in Lake Belau. Cycles of minerogenic input have been detected with duration of 20-25 years. Whether these cycles could represent slash and burn cycles has to be studied further.

Millennial-scale precipitation variability over Easter Island (South Pacific) during MIS 3: inter-hemispheric teleconnections with North Atlantic abrupt cold events

NASA Astrophysics Data System (ADS)

Margalef, O.; Cacho, I.; Pla-Rabes, S.; Cañellas-Boltà, N.; Pueyo, J. J.; Sáez, A.; Pena, L. D.; Valero-Garcés, B. L.; Rull, V.; Giralt, S.

2015-04-01

Marine Isotope Stage 3 (MIS 3, 59.4-27.8 kyr BP) is characterized by the occurrence of rapid millennial-scale climate oscillations known as Dansgaard-Oeschger cycles (DO) and by abrupt cooling events in the North Atlantic known as Heinrich events. Although both the timing and dynamics of these events have been broadly explored in North Atlantic records, the response of the tropical and subtropical latitudes to these rapid climatic excursions, particularly in the Southern Hemisphere, still remains unclear. The Rano Aroi peat record (Easter Island, 27° S) provides a unique opportunity to understand atmospheric and oceanic changes in the South Pacific during these DO cycles because of its singular location, which is influenced by the South Pacific Anticyclone (SPA), the Southern Westerlies (SW), and the Intertropical Convergence Zone (ITCZ) linked to the South Pacific Convergence Zone (SPCZ). The Rano Aroi sequence records 6 major events of enhanced precipitation between 38 and 65 kyr BP. These events are compared with other hydrological records from the tropical and subtropical band supporting a coherent regional picture, with the dominance of humid conditions in Southern Hemisphere tropical band during Heinrich Stadials (HS) 5, 5a and 6 and other Stadials while dry conditions prevailed in the Northern tropics. This antiphased hydrological pattern between hemispheres has been attributed to ITCZ migration, which in turn might be associated with an eastward expansion of the SPCZ storm track, leading to an increased intensity of cyclogenic storms reaching Easter Island. Low Pacific Sea Surface Temperature (SST) gradients across the Equator were coincident with the here-defined Rano Aroi humid events and consistent with a reorganization of Southern Pacific atmospheric and oceanic circulation also at higher latitudes during Heinrich and Dansgaard-Oeschger stadials.

Planetary Hypothesis, sub-Milankovitch frequencies and Holocene cold events

NASA Astrophysics Data System (ADS)

Compagnucci, R. H.; Cionco, R. G.; Agosta, E.; Wanner, H.

2013-05-01

The Planetary Hypothesis of solar cycles proposes that the movement of the Sun around the solar system barycenter modulates the solar cycles at several times scales. Using a 3-D model of the solar system (Cionco and Compagnucci, 2012) we derived the solar barycentric motion and various dynamic parameters such as the angular momentum (L= Lx, Ly, Lz) for the Holocene. Angular momentum inversions are sporadic and important events in the dynamics of the MSB: Lz becomes negative and giant planets are nearly aligned. These episodes are related to some grand solar grand minima such as Maunder and Dalton, and also to the recent deep minimum 2007-2010 which was preceded by a Lz inversion in 1990. During the Holocene several negative Lz episodes occur that are grouped in approximately millennia to centuries long periods. Each group is separated by ~2000 years where the Lz values remain positive, both generating a cycle between 1500 and 2500 years. The spectral analysis shows significant peaks at sub-Milankovitch frequencies. Furthermore, the analysis of the spatiotemporal variability of temperature defined six specific cold events (8200, 6300, 4700, 2700, 1550 and 550 years BP) during the Holocene (Wanner et al, 2011). During, and /or before, of these major climates cooling, a group of negative Lz episodes were presented. Oppositely the resulted during the warms periods were the lack of the angular movement inversion together with the extremes of positive Lz . Therefore, the origin of Holocene cold events seems to be linked to the gravitational influence of the planets, that is to say the planetary torque that has a non-negligible effect on the causes of the solar magnetic cycle. Acknowledgements:The support of the Grants PID-UTN1351, UBACYT N_:20020100101049, CONICET PIP PIP 114-201001-00250 and MINCYT-MEYS ARC/11/09. References Cionco, R.G.; Compagnucci,R.H. (2012) Dynamical characterization of the last prolonged solar minima , Advances in Space Research 50(10), 1434-1444 Wanner, H.; Solomina, O.; Grosjean, M.; Ritz, S. P.; Jetel, M. (2011) Structure and origin of Holocene cold events.Quat. Sci. Rev. 30, 3109-3123.;

Perfect 24-h management of hypertension: clinical relevance and perspectives.

PubMed

Kario, K

2017-04-01

Out-of-office blood pressure (BP) measured by home BP monitoring, or ambulatory BP monitoring, was demonstrated to be superior to office BP for the prediction of cardiovascular events. The J-HOP study of a nationwide Japanese cohort demonstrated that morning home BP is the best stroke predictor. In the prospective HONEST study of >21 000 hypertensives, on-treatment morning home BP was shown to be a strong predictor both of future coronary artery disease and stroke events. In subjects whose office BP was maintained at ⩾150 mm Hg, there was no increase in cardiovascular events when their morning systolic BP was well-controlled at <125 mm Hg. Since Asians show greater morning BP surges, it is particularly important for Asians to achieve 'perfect 24-hr BP control,' that is, the 24-h BP level, nocturnal BP dipping and BP variability including morning surge. The morning BP surge and the extremes of disrupted circadian rhythm (riser and extreme dipper patterns) are independent risks for stroke in hypertensives. A morning BP-guided approach is thus the first step toward perfect 24-h BP control, followed by the control of nocturnal hypertension. In the resonance hypothesis, the synergistic resonance of BP variability phenotypes would produce an extraordinary large 'dynamic BP surge' that can trigger a cardiovascular event, especially in high-risk patients with systemic hemodynamic atherothrombotic syndrome, a vicious cycle of exaggerated BP variability and vascular disease. In the future, information and communications technology and artificial intelligence technology with the innovation of wearable continuous surge BP monitoring will contribute to 'anticipation medicine' with the goal of zero cardiovascular events.

Status of lifestyle modifications in hypertension.

PubMed

Chhabra, M K; Lal, A; Sharma, K K

2001-09-01

Hypertension is essentially the elevation of arterial blood pressure beyond an arbitrary cut off point, though the dividing line between normal and elevated BP is lacking. Hypertension can be classified into primary, essential or idiopathic hypertension on one hand, and secondary one due to some disease itself. In treating hypertension, antihypertensives have their role, but attention may be directed towards some lifestyle modifications. As regarding dietary interventions, calorie restriction may influence the minimisation of BP. Body weight reduction, less alcohol consumption, salt restriction, potassium and calcium supplementation can enhance the process of lowering BP. The role of magnesium in hypertension is debatable. Serum cholesterol level is commonly elevated in hypertensive patients and its reduction reduces the risk of non-fatal coronary events. Diet rich in plant fibres either alone or with a low fat, low sodium could lower the BP by about 5 mm Hg in hypertensives. The omega-3-polyunsaturated fatty acids found in highest concentrations in cold water fishes have a modest antihypertensive effect. Caffeine contained in two cups of coffee may raise the BP by 5 mm Hg in infrequent users but in habitual users, caffeine has no role. Deficiency of vitamin C might lead to hypertension. As regarding behavioural changes, stopping smoking, regular physical exercise, relaxation therapies like yoga, etc, have definite beneficial effect on hypertensives. The antihypertensive effect of lifestyle modifications may obviate drug therapy. For this one or more of the lifestyle modifications should be tried initially in all hypertensive patients.

Transcriptome responses to heat- and cold-stress in ladybirds (Cryptolaemus montrouzieri Mulasnt) analyzed by deep-sequencing.

PubMed

Zhang, Yuhong; Wu, Hongsheng; Xie, Jiaqin; Jiang, Ruixin; Deng, Congshuang; Pang, Hong

2015-11-19

Changed temperature not only threaten agricultural production, but they also affect individual biological behavior, population and community of many insects, and consequently reduce the stability of our ecosystem. Insect's ability to respond to temperature stress evolved through a complex adaptive process, thus resulting in varied temperature tolerance among different insects. Both high and low extreme temperatures are detrimental to insect development since they constitute an important abiotic stress capable of inducing abnormal biological responses. Many studies on heat or cold tolerance of ladybirds have focused on measurements of physiological and biochemical indexes such as supercooling point, higher/lower lethal temperatures, survival rate, dry body weight, water content, and developmental duration. And studies of the molecular mechanisms of ladybird responses to heat or cold stress have focused on single genes, such as those encoding heat shock proteins, but has not been analyzed by transcriptome profiling. In this study, we report the use of Digital Gene Expression (DGE) tag profiling to gain insight into transcriptional events associated with heat- and cold-stress in C. montrouzieri. About 6 million tags (49 bp in length) were sequenced in a heat stress group, a cold stress group and a negative control group. We obtained 687 and 573 genes that showed significantly altered expression levels following heat and cold shock treatments, respectively. Analysis of the global gene expression pattern suggested that 42 enzyme-encoding genes mapped to many Gene Ontology terms are associated with insect's response to heat- and cold-stress. These results provide a global assessment of genes and molecular mechanisms involved in heat and cold tolerance.

Repetitive Electroacupuncture Attenuates Cold-Induced Hypertension through Enkephalin in the Rostral Ventral Lateral Medulla

PubMed Central

Li, Min; Tjen-A-Looi, Stephanie C.; Guo, Zhi-Ling; Longhurst, John C.

2016-01-01

Acupuncture lowers blood pressure (BP) in hypertension, but mechanisms underlying its action are unclear. To simulate clinical studies, we performed electroacupuncture (EA) in unanesthetized rats with cold-induced hypertension (CIH) induced by six weeks of cold exposure (6 °C). EA (0.1 – 0.4 mA, 2 Hz) was applied at ST36-37 acupoints overlying the deep peroneal nerve for 30 min twice weekly for five weeks while sham-EA was conducted with the same procedures as EA except for no electrical stimulation. Elevated BP was reduced after six sessions of EA treatment and remained low 72 hrs after EA in 18 CIH rats, but not in sham-EA (n = 12) and untreated (n = 6) CIH ones. The mRNA level of preproenkephalin in the rostral ventrolateral medulla (rVLM) 72 hr after EA was increased (n = 9), compared to the sham-EA (n = 6), untreated CIH rats (n = 6) and normotensive control animals (n = 6). Microinjection of ICI 174,864, a δ-opioid receptor antagonist, into the rVLM of EA-treated CIH rats partially reversed EA’s effect on elevated BP (n = 4). Stimulation of rVLM of CIH rats treated with sham-EA using a δ-opioid agonist, DADLE, decreased BP (n = 6). These data suggest that increased enkephalin in the rVLM induced by repetitive EA contributes to BP lowering action of EA. PMID:27775047

Repetitive Electroacupuncture Attenuates Cold-Induced Hypertension through Enkephalin in the Rostral Ventral Lateral Medulla.

PubMed

Li, Min; Tjen-A-Looi, Stephanie C; Guo, Zhi-Ling; Longhurst, John C

2016-10-24

Acupuncture lowers blood pressure (BP) in hypertension, but mechanisms underlying its action are unclear. To simulate clinical studies, we performed electroacupuncture (EA) in unanesthetized rats with cold-induced hypertension (CIH) induced by six weeks of cold exposure (6 °C). EA (0.1 - 0.4 mA, 2 Hz) was applied at ST36-37 acupoints overlying the deep peroneal nerve for 30 min twice weekly for five weeks while sham-EA was conducted with the same procedures as EA except for no electrical stimulation. Elevated BP was reduced after six sessions of EA treatment and remained low 72 hrs after EA in 18 CIH rats, but not in sham-EA (n = 12) and untreated (n = 6) CIH ones. The mRNA level of preproenkephalin in the rostral ventrolateral medulla (rVLM) 72 hr after EA was increased (n = 9), compared to the sham-EA (n = 6), untreated CIH rats (n = 6) and normotensive control animals (n = 6). Microinjection of ICI 174,864, a δ-opioid receptor antagonist, into the rVLM of EA-treated CIH rats partially reversed EA's effect on elevated BP (n = 4). Stimulation of rVLM of CIH rats treated with sham-EA using a δ-opioid agonist, DADLE, decreased BP (n = 6). These data suggest that increased enkephalin in the rVLM induced by repetitive EA contributes to BP lowering action of EA.

Climatic and palaeoecological changes during the mid- to Late Holocene transition in eastern China: high-resolution pollen and non-pollen palynomorph analysis at Pingwang, Yangtze coastal lowlands

NASA Astrophysics Data System (ADS)

Innes, James B.; Zong, Yongqiang; Wang, Zhanghua; Chen, Zhongyuan

2014-09-01

The transition to the Late Holocene/Neoglacial occurred as a worldwide process of climatic deterioration from the optimum thermal conditions of the mid-Holocene, culminating in an abrupt decline around 4200 cal yr ago, in a period of severe climatic deterioration that lasted for two or three centuries. This sudden climatic event has been recorded in many proxy data archives from around the world, and its effects were manifest in different ways depending on the reaction of regional weather systems and conditions, but often as greatly increased aridity and/or cold temperatures. It has been regarded as causing or contributing to the sudden collapse of several well-established human societies at that time, including advanced agricultural Late Neolithic cultures in eastern China. We have used high-resolution pollen and non-pollen palynomorph analysis to examine the nature of this climatic transition through its impacts on the vegetation and hydrology at Pingwang, a site in the Yangtze coastal lowlands which has no evidence of complicating environmental influences such as sea-level rise or significant human land-use activity, factors previously suggested as alternative reasons for changes in forest composition. Our results show two phases of forest alteration, one gradual from about 5500 cal BP and one sudden at about 4200 cal BP., in which the frequencies of subtropical forest elements fall and are replaced by those of conifers and cold-tolerant trees. Total arboreal pollen frequencies do not decline and the proportion of temperate forest trees, tolerant of a wide range of temperatures, remains unchanged throughout, both ruling out human land clearance as a cause of the change in forest composition. As these dates accord very well with the known timings of climate deterioration established from other proxy archives in the region, we conclude that climate was the main driver of vegetation change in eastern China at the mid- to Late Holocene transition. Our hydrological results support the view that a combination of rising local water level and climatic cooling during the 4200 cal BP event was the probable cause of societal collapse in the lower Yangtze valley.

A synoptic approach to weather conditions discloses a relationship with ambulatory blood pressure in hypertensives.

PubMed

Morabito, Marco; Crisci, Alfonso; Orlandini, Simone; Maracchi, Giampiero; Gensini, Gian F; Modesti, Pietro A

2008-07-01

Higher blood pressure (BP) values in cold than in hot months has been documented in hypertensives. These changes may potentially contribute to the observed excess winter cardiovascular mortality. However, the association with weather has always been investigated by considering the relationship with a single variable rather than considering the combination of ground weather variables characterizing a specific weather pattern (air mass (AM)). We retrospectively investigate in Florence (Italy) the relationship between BP and specific AMs in hypertensive subjects (n = 540) referred to our Hypertension Unit for 24-h ambulatory BP monitoring during the period of the year characterized by the highest weather variability (winter). Five different winter daily AMs were classified according to the combination of ground weather data (air temperature, cloud cover, relative humidity, atmospheric pressure, wind speed, and direction). Multiple variable analysis selected the AM as a significant predictor of mean 24-h BP (P < 0.01 for diastolic BP (DBP) and P < 0.05 for systolic BP (SBP)), daytime DBP (P < 0.001) and nighttime BP (P < 0.01 for both SBP and DBP), with higher BP values observed in cyclonic (unstable, cloudy, and mild weather) than in anticyclonic (settled, cloudless, and cold weather) days. When the association with 2-day sequences of AMs was considered, an increase in ambulatory BP followed a sudden day-to-day change of weather pattern going from anticyclonic to cyclonic days. The weather considered as a combination of different weather variables may affect BP. The forecast of a sudden change of AM could provide important information helpful for hypertensives during winter.

Genome-wide association study identifies 8 novel loci associated with blood pressure responses to interventions in Han Chinese.

PubMed

He, Jiang; Kelly, Tanika N; Zhao, Qi; Li, Hongfan; Huang, Jianfeng; Wang, Laiyuan; Jaquish, Cashell E; Sung, Yun Ju; Shimmin, Lawrence C; Lu, Fanghong; Mu, Jianjun; Hu, Dongsheng; Ji, Xu; Shen, Chong; Guo, Dongshuang; Ma, Jixiang; Wang, Renping; Shen, Jinjin; Li, Shengxu; Chen, Jing; Mei, Hao; Chen, Chung-Shiuan; Chen, Shufeng; Chen, Jichun; Li, Jianxin; Cao, Jie; Lu, Xiangfeng; Wu, Xigui; Rice, Treva K; Gu, C Charles; Schwander, Karen; Hamm, L Lee; Liu, Depei; Rao, Dabeeru C; Hixson, James E; Gu, Dongfeng

2013-12-01

Blood pressure (BP) responses to dietary sodium and potassium intervention and cold pressor test vary considerably among individuals. We aimed to identify novel genetic variants influencing individuals' BP responses to dietary intervention and cold pressor test. We conducted a genome-wide association study of BP responses in 1881 Han Chinese and de novo genotyped top findings in 698 Han Chinese. Diet-feeding study included a 7-day low-sodium (51.3 mmol/d), a 7-day high-sodium (307.8 mmol/d), and a 7-day high-sodium plus potassium supplementation (60 mmol/d). Nine BP measurements were obtained during baseline observation and each intervention period. The meta-analyses identified 8 novel loci for BP phenotypes, which physically mapped in or near PRMT6 (P=7.29 × 10(-9)), CDCA7 (P=3.57 × 10(-8)), PIBF1 (P=1.78 × 10(-9)), ARL4C (P=1.86 × 10(-8)), IRAK1BP1 (P=1.44 × 10(-10)), SALL1 (P=7.01 × 10(-13)), TRPM8 (P=2.68 × 10(-8)), and FBXL13 (P=3.74 × 10(-9)). There was a strong dose-response relationship between the number of risk alleles of these independent single-nucleotide polymorphisms and the risk of developing hypertension during the 7.5-year follow-up in the study participants. Compared with those in the lowest quartile of risk alleles, odds ratios (95% confidence intervals) for those in the second, third, and fourth quartiles were 1.39 (0.97, 1.99), 1.72 (1.19, 2.47), and 1.84 (1.29, 2.62), respectively (P=0.0003 for trend). Our study identified 8 novel loci for BP responses to dietary sodium and potassium intervention and cold pressor test. The effect size of these novel loci on BP phenotypes is much larger than those reported by the previously published studies. Furthermore, these variants predict the risk of developing hypertension among individuals with normal BP at baseline.

Quantifying rapid changes in cardiovascular state with a moving ensemble average.

PubMed

Cieslak, Matthew; Ryan, William S; Babenko, Viktoriya; Erro, Hannah; Rathbun, Zoe M; Meiring, Wendy; Kelsey, Robert M; Blascovich, Jim; Grafton, Scott T

2018-04-01

MEAP, the moving ensemble analysis pipeline, is a new open-source tool designed to perform multisubject preprocessing and analysis of cardiovascular data, including electrocardiogram (ECG), impedance cardiogram (ICG), and continuous blood pressure (BP). In addition to traditional ensemble averaging, MEAP implements a moving ensemble averaging method that allows for the continuous estimation of indices related to cardiovascular state, including cardiac output, preejection period, heart rate variability, and total peripheral resistance, among others. Here, we define the moving ensemble technique mathematically, highlighting its differences from fixed-window ensemble averaging. We describe MEAP's interface and features for signal processing, artifact correction, and cardiovascular-based fMRI analysis. We demonstrate the accuracy of MEAP's novel B point detection algorithm on a large collection of hand-labeled ICG waveforms. As a proof of concept, two subjects completed a series of four physical and cognitive tasks (cold pressor, Valsalva maneuver, video game, random dot kinetogram) on 3 separate days while ECG, ICG, and BP were recorded. Critically, the moving ensemble method reliably captures the rapid cyclical cardiovascular changes related to the baroreflex during the Valsalva maneuver and the classic cold pressor response. Cardiovascular measures were seen to vary considerably within repetitions of the same cognitive task for each individual, suggesting that a carefully designed paradigm could be used to capture fast-acting event-related changes in cardiovascular state. © 2017 Society for Psychophysiological Research.

The spread of modern humans in Europe

PubMed Central

Hoffecker, John F.

2009-01-01

The earliest credible evidence of Homo sapiens in Europe is an archaeological proxy in the form of several artifact assemblages (Bohunician) found in South-Central and possibly Eastern Europe, dating to ≤48,000 calibrated radiocarbon years before present (cal BP). They are similar to assemblages probably made by modern humans in the Levant (Emiran) at an earlier date and apparently represent a population movement into the Balkans during a warm climate interval [Greenland Interstadial 12 (GI 12)]. A second population movement may be represented by a diverse set of artifact assemblages (sometimes termed Proto-Aurignacian) found in the Balkans, parts of Southwest Europe, and probably in Eastern Europe, and dating to several brief interstadials (GI 11–GI 9) that preceded the beginning of cold Heinrich Event 4 (HE4) (≈40,000 cal BP). They are similar to contemporaneous assemblages made by modern humans in the Levant (Ahmarian). The earliest known human skeletal remains in Europe that may be unequivocally assigned to H. sapiens (Peçstera cu Oase, Romania) date to this time period (≈42,000 cal BP) but are not associated with artifacts. After the Campanian Ignimbrite volcanic eruption (40,000 cal BP) and the beginning of HE4, artifact assemblages assigned to the classic Aurignacian, an industry associated with modern human skeletal remains that seems to have developed in Europe, spread throughout the continent. PMID:19571003

Geoarchaeological and paleohydrological evidence for a clovis-age drought in North America and its bearing on extinction

NASA Astrophysics Data System (ADS)

Haynes, C. Vance

1991-05-01

At the Murray Springs Clovis site in southeastern Arizona, stratigraphic and geomorphic evidence indicates that an abnormally low water table 10,900 yr B.P. was followed soon thereafter by a water-table rise accompanied by the deposition of an algal mat (the black mat) that buried mammoth tracks, Clovis artifacts, and a well. This water-table fluctuation correlates with pluvial lake fluctuations in the Great Basin during and immediately following Clovis occupation of that region. Many elements of Pleistocene megafauna in North America became extinct during the dry period. Oxygen isotope records show a marked decrease in δ18O correlated with the Younger Dryas cold-dry event of northern Europe which ended 10,750 yr B.P., essentially the same time as the water table began to rise in southeastern Arizona. Clovis hunters may have found large game animals easier prey when concentrated at water holes and under stress. If so, both climate and human predation contributed to Pleistocene extinction in America.

The influence of extreme seasonality on lake temperatures during Younger Dryas

NASA Astrophysics Data System (ADS)

Schenk, F.; Stranne, C.; Wohlfarth, B.

2016-12-01

The Younger Dryas cold reversal ( 12.9 to 11.7 kyr BP) is the last abrupt climate change event interrupting the warming of the late deglaciation right before the onset of the Holocene. The spatial pattern of the cooling event seen in proxy data is largely consistent with those of climate simulations and suggests that the Younger Dryas is linked to a significant slowdown of the Atlantic Meridional Overturning Circulation (AMOC). However, despite the strong ocean cooling of up to 6 K along the European coasts and a significant southward extension of sea-ice during the Younger Dryas, different climate simulations do not reproduce summer cooling over Europe as seen in July lake temperature reconstructions based on chironomids. Aquatic plants used as climate indicator species do in contrast not show such a strong cooling and are more in line with climate simulations. To investigate this discrepancy, we use two numerical lake models driven by high resolution climate model output for the Younger Dryas and the preceding warm period of the late Alleröd ( 13 kyr BP). First, we investigate to which extent simulated lake temperatures in summer still reflect atmospheric summer temperatures despite a strong increase in seasonality during Younger Dryas. Because the (paleo-)lake depths are usually not well known, we use the lake models to test their sensitivity to changes in seasonality as a function of depth. Second, we artificially change the temperatures used as forcing for the lake models to investigate how cold air temperatures would need to be to match the up to 5 K July cooling suggested by chironomids. The results show that more care needs to be taken about the location and (paleo-)lake depths when comparing lake temperatures with simulated air temperatures. The simulated atmospheric circulation patterns during summer appears to be rather insensitive to the Younger Dryas cooling owing to the dominance of high atmospheric pressure over the Euro-Atlantic region. This would support a recent study linking extremely cold North Atlantic Ocean temperature anomalies to severe heat waves in Europe since the 1980s (Duchez et al. 2016, ERL, Vol. 11, No. 7).

Efficacy and position of endurance training as a non-drug therapy in the treatment of arterial hypertension.

PubMed

Ketelhut, R G; Franz, I W; Scholze, J

1997-10-01

Regular conditioning has been well documented to exert a beneficial effect on cardiovascular risk factors and to improve overall cardiovascular health and to reduce the incidence of coronary disease. There are conflicting results concerning the effect of physical exercise on blood pressure (BP) in hypertensive patients and its importance in the treatment of hypertension. Therefore 10 male patients with mild arterial hypertension were studied in order to define the BP response to long-term aerobic training (60 min twice a week) under resting conditions, during standardised ergometric workload, during isometric exercise, during cold pressor testing and during 24-h BP monitoring. After 18 months of regular training there were significant reductions in arterial pressures at rest, during and after standardised ergometry and during isometric and cold pressor testing when compared with pre-training. The heart rate also decreased significantly during exercise testing thus implying a decrease in myocardial oxygen consumption. After long-term training, a reduction in systolic and diastolic BP could also be shown during 24-h ambulatory BP monitoring. These results demonstrate that long-term aerobic training leads to a decrease in systolic and diastolic BP at rest, during exercise and during 24-h BP monitoring and imply a beneficial effect in the management of hypertension that is nearly comparable to that of drug therapy.

Reproductive organ and vascular specific promoter of the rice plasma membrane Ca2+ATPase mediates environmental stress responses in plants.

PubMed

Huda, Kazi Md Kamrul; Banu, Mst Sufara Akhter; Pathi, Krishna Mohan; Tuteja, Narendra

2013-01-01

Plasma membrane Ca(2+)ATPase is a transport protein in the plasma membrane of cells and helps in removal of calcium (Ca(2+)) from the cell, hence regulating Ca(2+) level within cells. Though plant Ca(2+)ATPases have been shown to be involved in plant stress responses but their promoter regions have not been well studied. The 1478 bp promoter sequence of rice plasma membrane Ca(2+)ATPase contains cis-acting elements responsive to stresses and plant hormones. To identify the functional region, serial deletions of the promoter were fused with the GUS sequence and four constructs were obtained. These were differentially activated under NaCl, PEG cold, methyl viologen, abscisic acid and methyl jasmonate treatments. We demonstrated that the rice plasma membrane Ca(2+)ATPase promoter is responsible for vascular-specific and multiple stress-inducible gene expression. Only full-length promoter showed specific GUS expression under stress conditions in floral parts. High GUS activity was observed in roots with all the promoter constructs. The -1478 to -886 bp flanking region responded well upon treatment with salt and drought. Only the full-length promoter presented cold-induced GUS expression in leaves, while in shoots slight expression was observed for -1210 and -886 bp flanking region. The -1210 bp deletion significantly responded to exogenous methyl viologen and abscisic acid induction. The -1210 and -886 bp flanking region resulted in increased GUS activity in leaves under methyl jasmonate treatments, whereas in shoots the -886 bp and -519 bp deletion gave higher expression. Salicylic acid failed to induce GUS activities in leaves for all the constructs. The rice plasma membrane Ca(2+)ATPase promoter is a reproductive organ-specific as well as vascular-specific. This promoter contains drought, salt, cold, methyl viologen, abscisic acid and methyl jasmonate related cis-elements, which regulated gene expression. Overall, the tissue-specificity and inducible nature of this promoter could grant wide applicability in plant biotechnology.

Late Wisconsin and Early Holocene runoff through the upper Ohio River basin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kite, J.S.

A tentative absolute chronology is emerging from radiocarbon dates on glacial, alluvial and colluvial sediments in the upper Ohio River basin. Radiocarbon dates for Gallipolis Lock and Dam indicate the river eroded down to its present bedrock floor before 22,400 yr B.P. Data from several sites indicate aggradation began soon after 22,400 yr B.P., coincident with, or just before, a glacier advance into the upper Ohio basin. Sand and gravel aggraded in glaciated tributaries and the main valley, whereas silt, fine sand, and clay accumulated in unglaciated tributaries. Slope instability and colluvial deposition were extensive at this time. Aggradation continuedmore » until 25 to 40 m of sediments filled the Ohio River Valley. The paucity of radiocarbon dates prohibits precise determination of when peak aggradation occurred and how that peak related to glacial and climatic events. Although the Laurentide Ice Sheet retreated out of the basin by about 14,000 yr B.P., the river remained braided until at least 13,000 yr B.P., possibly because of slope instability in a cold late Wisconsin climate or the time required for the river to adjust to reduced outwash sediment supply. Coarse late-glacial channel deposits may reflect increased flood discharges after 13,000 B.P. and onset of the transition from a braided system to a meandering channel. However, the upper Ohio River seems not to have taken on its modern morphology until the early Holocene. Most dated overbank deposits on tributaries are younger than 10,000 yr B.P.; most on the Ohio River are younger than 8,500 yr B.P.« less

Cloning and Functional Analysis of Phosphoethanolamine Methyltransferase Promoter from Maize (Zea mays L.)

PubMed Central

Niu, Gai-Li; Gou, Wei; Han, Xiang-Long; Qin, Cheng; Zhang, Li-Xin; Ashraf, Muhammad

2018-01-01

Betaine, a non-toxic osmoprotectant, is believed to accumulate considerably in plants under stress conditions to maintain the osmotic pressure and promote a variety of processes involved in growth and development. Phosphoethanolamine N-methyltransferase (PEAMT), a key enzyme for betaine synthesis, is reported to be regulated by its upstream promoter. In the present investigation, by using the transgenic approach, a 1048 bp long promoter region of ZmPEAMT gene from Zea mays was cloned and functionally characterized in tobacco. Computational analysis affirmed the existence of abiotic stress responsive cis-elements like ABRE, MYC, HST, LST etc., as well as pathogen, wound and phytohormone responsive motifs. For transformation in tobacco, four 5′-deletion constructs of 826 bp (P2), 642 bp (P3), 428 bp (P4) and 245 bp (P5) were constructed from the 1048 bp (P1) promoter fragment. The transgenic plants generated through a single event exhibited a promising expression of GUS reporter protein in the leaf tissues of treated with salt, drought, oxidative and cold stress as well as control plants. The GUS expression level progressively reduced from P1 to P5 in the leaf tissues, whereas a maximal expression was observed with the P3 construct in the leaves of control plants. The expression of GUS was noted to be higher in the leaves of osmotically- or salt-treated transgenic plants than that in the untreated (control) plants. An effective expression of GUS in the transgenic plants manifests that this promoter can be employed for both stress-inducible and constitutive expression of gene(s). Due to this characteristic, this potential promoter can be effectively used for genetic engineering of several crops. PMID:29316727

Abrupt climate change around 4 ka BP: Role of the Thermohaline circulation as indicated by a GCM experiment

NASA Astrophysics Data System (ADS)

Wang, Shaowu; Zhou, Tianjun; Cai, Jingning; Zhu, Jinhong; Xie, Zhihui; Gong, Daoyi

2004-04-01

A great deal of palaeoenvironmental and palaeoclimatic evidence suggests that a predominant temperature drop and an aridification occurred at ca. 4.0 ka BP. Palaeoclimate studies in China support this dedution. The collapse of ancient civilizations at ca. 4.0 ka BP in the Nile Valley and Mesopotamia has been attributed to climate-induced aridification. A widespread alternation of the ancient cultures was also found in China at ca. 4.0 ka BP in concert with the collapse of the civilizations in the Old World. Palaeoclimatic studies indicate that the abrupt climate change at 4.0 ka BP is one of the realizations of the cold phase in millennial scale climate oscillations, which may be related to the modulation of the Thermohaline Circulation (THC) over the Atlantic Ocean. Therefore, this study conducts a numerical experiment of a GCM with SST forcing to simulate the impact of the weakening of the THC. Results show a drop in temperature from North Europe, the northern middle East Asia, and northern East Asia and a significant reduction of precipitation in East Africa, the Middle East, the Indian Peninsula, and the Yellow River Valley. This seems to support the idea that coldness and aridification at ca. 4.0 ka BP was caused by the weakening of the THC.

Calyptogena-cemented rocks and concretions from the eastern part of Nankai accretionary prism: Age and geochemistry of uranium

NASA Astrophysics Data System (ADS)

Lalou, Claude; Fontugne, Michel; Lallemand, Serge E.; Lauriat-Rage, Agnès

1992-04-01

Calyptogena valves included in a carbonate-rich cement, and fragments of a carbonate-rich chimney, have been examined for their stable isotopic (C and O) composition,14C activity and uranium series disequilibrium. The fossil shells were formed essentially with seawater carbon and a negligible contribution of cold seepage organic carbon, as shown by theirδ13C values. This allows the14C method to be used to determine their age. A fairly good concordance between the14C and230Th234U ages of the youngest shells gives confidence in the dating of the older samples using the latter technique. Thus, theCalyptogena are dated at ca. 150,000 and 20,000 yrs B.P. They have been preserved from dissolution by rapid cementation by a supersaturated carbonate solution. The cement is especially rich in uranium (as high as 75 ppm), whose source is seawater; the enrichment is due to local reducing conditions brought about by the bacterial decomposition of the soft tissues of the bivalves shortly after death. TheCalyptogena that probably developed between these two events (the events of ca. 20,000 and 150,000 yrs) have not been preserved from dissolution because, as is presently the case, the cold seepages were undersaturated with calcium carbonate. The two events probably represent periods of intense fluid venting connected with tectonic activity.

Comparative Transcriptomic Analysis of the Response to Cold Acclimation in Eucalyptus dunnii

PubMed Central

Liu, Yiqing; Jiang, Yusong; Lan, Jianbin; Zou, Yong; Gao, Junping

2014-01-01

Eucalyptus dunnii is an important macrophanerophyte with high economic value. However, low temperature stress limits its productivity and distribution. To study the cold response mechanisms of E. dunnii, 5 cDNA libraries were constructed from mRNA extracted from leaves exposed to cold stress for varying lengths of time and were evaluated by RNA-Seq analysis. The assembly of the Illumina datasets was optimized using various assembly programs and parameters. The final optimized assembly generated 205,325 transcripts with an average length of 1,701 bp and N50 of 2,627 bp, representing 349.38 Mb of the E. dunnii transcriptome. Among these transcripts, 134,358 transcripts (65.4%) were annotated in the Nr database. According to the differential analysis results, most transcripts were up-regulated as the cold stress prolonging, suggesting that these transcripts may be involved in the response to cold stress. In addition, the cold-relevant GO categories, such as ‘response to stress’ and ‘translational initiation’, were the markedly enriched GO terms. The assembly of the E. dunnii gene index and the GO classification performed in this study will serve as useful genomic resources for the genetic improvement of E. dunnii and also provide insights into the molecular mechanisms of cold acclimation in E. dunnii. PMID:25412179

Geochemical proxies of North American freshwater routing during the Younger Dryas cold event.

PubMed

Carlson, Anders E; Clark, Peter U; Haley, Brian A; Klinkhammer, Gary P; Simmons, Kathleen; Brook, Edward J; Meissner, Katrin J

2007-04-17

The Younger Dryas cold interval represents a time when much of the Northern Hemisphere cooled from approximately 12.9 to 11.5 kiloyears B.P. The cause of this event, which has long been viewed as the canonical example of abrupt climate change, was initially attributed to the routing of freshwater to the St. Lawrence River with an attendant reduction in Atlantic meridional overturning circulation. However, this mechanism has recently been questioned because current proxies and dating techniques have been unable to confirm that eastward routing with an increase in freshwater flux occurred during the Younger Dryas. Here we use new geochemical proxies (DeltaMg/Ca, U/Ca, and (87)Sr/(86)Sr) measured in planktonic foraminifera at the mouth of the St. Lawrence estuary as tracers of freshwater sources to further evaluate this question. Our proxies, combined with planktonic delta(18)O(seawater) and delta(13)C, confirm that routing of runoff from western Canada to the St. Lawrence River occurred at the start of the Younger Dryas, with an attendant increase in freshwater flux of 0.06 +/- 0.02 Sverdrup (1 Sverdrup = 10(6) m(3).s(-1)). This base discharge increase is sufficient to have reduced Atlantic meridional overturning circulation and caused the Younger Dryas cold interval. In addition, our data indicate subsequent fluctuations in the freshwater flux to the St. Lawrence River of approximately 0.06-0.12 Sverdrup, thus explaining the variability in the overturning circulation and climate during the Younger Dryas.

Geochemical proxies of North American freshwater routing during the Younger Dryas cold event

USGS Publications Warehouse

Carlson, A.E.; Clark, P.U.; Haley, B.A.; Klinkhammer, G.P.; Simmons, K.; Brook, E.J.; Meissner, K.J.

2007-01-01

The Younger Dryas cold interval represents a time when much of the Northern Hemisphere cooled from ???12.9 to 11.5 kiloyears B.P. The cause of this event, which has long been viewed as the canonical example of abrupt climate change, was initially attributed to the routing of freshwater to the St. Lawrence River with an attendant reduction in Atlantic meridional overturning circulation. However, this mechanism has recently been questioned because current proxies and dating techniques have been unable to confirm that eastward routing with an increase in freshwater flux occurred during the Younger Dryas. Here we use new geochemical proxies (??Mg/Ca, U/Ca, and 87Sr/86Sr) measured in planktonic foraminifera at the mouth of the St. Lawrence estuary as tracers of freshwater sources to further evaluate this question. Our proxies, combined with planktonic ??18Oseawater and ??13C, confirm that routing of runoff from western Canada to the St. Lawrence River occurred at the start of the Younger Dryas, with an attendant increase in freshwater flux of 0.06 ?? 0.02 Sverdrup (1 Sverdrup = 106 m3??s-1). This base discharge increase is sufficient to have reduced Atlantic meridional overturning circulation and caused the Younger Dryas cold interval. In addition, our data indicate subsequent fluctuations in the freshwater flux to the St. Lawrence River of ???0.06-0.12 Sverdrup, thus explaining the variability in the overturning circulation and climate during the Younger Dryas. ?? 2007 by The National Academy of Sciences of the USA.

Patterns of human occupation during the early Holocene in the Central Ebro Basin (NE Spain) in response to the 8.2 ka climatic event

NASA Astrophysics Data System (ADS)

González-Sampériz, P.; Utrilla, P.; Mazo, C.; Valero-Garcés, B.; Sopena, MC.; Morellón, M.; Sebastián, M.; Moreno, A.; Martínez-Bea, M.

2009-03-01

The Central Ebro River Basin (NE Spain) is the most northern area of truly semi-arid Mediterranean climate in Europe and prehistoric human occupation there has been strongly influenced by this extreme environmental condition. Modern climate conditions single out this region due to the harsh environment, characterised by the highest absolute summer temperatures of the Ebro River Basin. The Bajo Aragón region (SE Ebro River Basin) was intensively populated during the Early Holocene (9400-8200 cal yr BP) but the settlements were abandoned abruptly at around 8200 cal yr BP. We propose that this "archaeological silence" was caused by the regional impact of the global abrupt 8.2 ka cold event. Available regional paleoclimate archives demonstrate the existence of an aridity crisis then that interrupted the humid Early Holocene. That environmental crisis would have forced hunter-gatherer groups from the Bajo Aragón to migrate to regions with more favourable conditions (i.e. more humid mountainous areas) and only return in the Neolithic. Coherently, archaeological sites persist during this crisis in the nearby Iberian Range (Maestrazgo) and the North Ebro River area (Pre-Pyrenean mountains and along the northwestern Ebro Basin).

Temporal and spatial aspects of peatland initiation following deglaciation in North America

USGS Publications Warehouse

Gorham, E.; Lehman, C.; Dyke, A.; Janssens, J.; Dyke, L.

2007-01-01

A set of simple ecological models accounts well for the cumulative initiation of peatlands throughout North America in relation to glacial retreat. The most parsimonious form incorporates, first, a delay term to account for the lag during which newly deglaciated land became suitable for peatland initiation and, second, an intrinsic rate of initiation related to the probability of migration and establishment of plant propagules from elsewhere. The goodness of fit of the models, based on 1680 basal-peat dates throughout the continent, allows projection of past trends into the future. Factors contributing to the lag of about 4000 years between deglaciation and peatland initiation are suggested and data on colonization of deglaciated land by beavers (known to initiate peatlands) are presented. The rate of peatland initiation peaked between 7000 and 8000 years ago, but remains appreciable today. A marked depression of peatland initiation (8360-8040 BP) interrupted the peak rate. The time of the interruption matches the 8200 BP cold-dry event recorded in Greenland ice cores, and suggests that this event caused a substantial, continent-wide depression of an important ecosystem function, i.e., carbon sequestration from the atmosphere by peat deposition. Spontaneous initiation of new peatlands is projected to continue for millennia to come. ?? 2006 Elsevier Ltd. All rights reserved.

Reconstruction of the South Atlantic Subtropical Dipole index for the past 12,000 years from surface temperature proxy

PubMed Central

Wainer, Ilana; Prado, Luciana Figueiredo; Khodri, Myriam; Otto-Bliesner, Bette

2014-01-01

Climate indices based on sea surface temperature (SST) can synthesize information related to physical processes that describe change and variability in continental precipitation from floods to droughts. The South Atlantic Subtropical Dipole index (SASD) is based on the distribution of SST in the South Atlantic and fits these criteria. It represents the dominant mode of variability of SST in the South Atlantic, which is modulated by changes in the position and intensity of the South Atlantic Subtropical High. Here we reconstructed an index of the South Atlantic Ocean SST (SASD-like) for the past twelve thousand years (the Holocene period) based on proxy-data. This has great scientific implications and important socio-economic ramifications because of its ability to infer variability of precipitation and moisture over South America where past climate data is limited. For the first time a reconstructed index based on proxy data on opposite sides of the SASD-like mode is able to capture, in the South Atlantic, the significant cold events in the Northern Hemisphere at 12.9−11.6 kyr BP and 8.6−8.0 ky BP. These events are related, using a transient model simulation, to precipitation changes over South America. PMID:24924600

Reconstruction of the South Atlantic Subtropical Dipole index for the past 12,000 years from surface temperature proxy.

PubMed

Wainer, Ilana; Prado, Luciana Figueiredo; Khodri, Myriam; Otto-Bliesner, Bette

2014-06-13

Climate indices based on sea surface temperature (SST) can synthesize information related to physical processes that describe change and variability in continental precipitation from floods to droughts. The South Atlantic Subtropical Dipole index (SASD) is based on the distribution of SST in the South Atlantic and fits these criteria. It represents the dominant mode of variability of SST in the South Atlantic, which is modulated by changes in the position and intensity of the South Atlantic Subtropical High. Here we reconstructed an index of the South Atlantic Ocean SST (SASD-like) for the past twelve thousand years (the Holocene period) based on proxy-data. This has great scientific implications and important socio-economic ramifications because of its ability to infer variability of precipitation and moisture over South America where past climate data is limited. For the first time a reconstructed index based on proxy data on opposite sides of the SASD-like mode is able to capture, in the South Atlantic, the significant cold events in the Northern Hemisphere at 12.9-11.6 kyr BP and 8.6-8.0 ky BP. These events are related, using a transient model simulation, to precipitation changes over South America.

Did Heinrich Events Impact Climate in the Southwest Pacific? - Evidence From New Zealand Speleothems

NASA Astrophysics Data System (ADS)

Whittaker, T. E.; Hendy, C. H.; Hellstrom, J.

2008-12-01

Speleothems, layered calcium-carbonate cave deposits such as stalagmites, stalactites and flowstones, have been shown to offer much potential as paleoclimate archives. We present a new, high-resolution, independently-dated, paleoclimate record from a stalagmite which formed in Hollywood Cave (42.0°S, 171.5°E) on South Island, New Zealand. Over 700 stable oxygen and carbon isotope measurement pairs are supported by a chronology from 18 sequential 230Th dates. The stalagmite grew between 73 and 11 kyr B.P. Growth rates varied from ~1-54 mm/kyr and data resolution yields one sample per 10- 320 years. Weak covariance between δ13C and δ18O in the speleothem calcite suggests that recorded climate signals are primarily driven by mean annual precipitation amount and source. Both stable isotope proxies indicate relatively cold and dry conditions prevailed for much of the period 73-11 kyr B.P. However, abrupt-onset, millennial-scale shifts to wet and cool climate interrupt the dry conditions at 67.7-61, 56-55, 50.5-47.5, 40-39, 30.5-29, 25.5-24.3, 16.1-15, and 12.2-11.8 kyr B.P. Significantly, these eight abrupt climate changes occur synchronously with widely accepted ages for Heinrich events H6-H0 (including H5a). Many of these abrupt events can also be matched to known periods of glacier advance in the Southern Alps, New Zealand, which, arguably, were driven by increased mean annual precipitation and reduced potential for summer melting. In addition, preliminary stable isotope data (> 550 δ13C and δ18O pairs) from two North Island, New Zealand (~38°S), stalagmites will be shown that also displays abrupt shifts from relatively dry to wet climate during the period 60-6 kyr B.P. In combination, these results argue stongly for coeval climate changes in antipodean locations, and therefore provide compelling evidence for globally synchronous climate variability during the last glacial period.

The Environment and Blood Pressure.

PubMed

Brook, Robert D

2017-05-01

A host of environmental factors can significantly increase arterial blood pressure (BP) including cold temperature, high altitude, loud noises, and ambient air pollutants. Although brief exposures acutely elevate BP, over the long term, chronic exposures may be capable of promoting the development of sustained hypertension. Given their omnipresent nature, environmental factors may play a role in worsening BP control and heightening overall cardiovascular risk at the global public health level. Copyright © 2016 Elsevier Inc. All rights reserved.

Pollen record of the mid- to late-Holocene centennial climate change on the East coast of South Korea and its influential factors

NASA Astrophysics Data System (ADS)

Song, Bing; Yi, Sangheon; Jia, Hongjuan; Nahm, Wook-Hyun; Kim, Jin-Cheul; Lim, Jaesoo; Lee, Jin-Young; Sha, Longbin; Mao, Limi; Yang, Zhongyong; Nakanishi, Toshimichi; Hong, Wan; Li, Zhen

2018-01-01

To understand historical climate change in western Pacific coastal areas, a sediment core (SOJ-2) from the stable sedimentary environment of the Songjiho Lagoon on the east coast of South Korea was obtained for centennial-resolution palynological analysis. The ages of the SOJ-2 core is well controlled by carbon 14 dating with high-resolution accelerator mass spectrometry (AMS), and the results indicated a general warm to cold climate trend from the mid-Holocene to the present, which can be divided into two different stages: a warmer stage between 6842 and 1297 cal yr BP and a colder stage from 1297 cal yr BP to the present, with fluctuations during these stages. The climate was wetter from 6842 to 6227 cal yr BP and 4520 to 1297 cal yr BP and was drier from 6227 to 4520 cal yr BP. The climate changed to cold and dry during the period from 1297-425 cal yr BP. The impact of human activity on the climate began at approximately 1297 cal yr BP and became pronounced starting in 425 cal yr BP. The general cooling trend may represent a response to decreasing solar insolation; however, the relative dryness or wetness of the climate may have been co-determined by westerlies and the East Asian summer monsoon (EASM). The climate had a teleconnection with the North Atlantic region, resulting from changes in solar activity. Nevertheless, EI Niño-Southern Oscillation (ENSO) activity played an important role in impacting the EASM changes in western Pacific coastal areas.

Large Nankai Trough earthquake and tsunami found in lacustrine deposits through late Holocene-time along the western coast of Kii Peninsula, southwestern Japan

NASA Astrophysics Data System (ADS)

Okamura, M.; Matsuoka, H.; Tsuzuki, M.; Toraya, K.

2015-12-01

We continue paleo-seismic studies through Late Holocene-time in coastal marsh ponds along the Nankai Trough . These ponds which are co-seismic subsidence areas have continuous muddy sediment stratigraphy and sporadic tsunami induced coarse material. Well controlled age data has been collected from the core-sample that contains plant remains under anoxic sedimentary environment . Total 21 cores collected from two coastal ponds Ashihama-ike and Zasa-ike which locate behind beach-ridge along southeastern coast of Kii Peninsula under Tokai/Tonankai Earthquake assumption areas. Tsunami events are recognized after eighty AMS C-14 dating through recent (core top) to 7300 yBP interval. Among these interval, two remarkable events found in sediment, which are 2050yBP to 2300yBP (=2K event) and 1000yBP to 1100 yBP. 2k event consists thick sand, well rounded gravel in chaotic mud and wood fragment derived from forests surrounding lakes. Later event is correspond to the historical Ninna Nankai earthquake (AD887, 26 August under the old lunar calendar).　Rather small events are occurred in 3500yBP and 1100yBP. These events are found from both of two ponds which has two kilometers in distance each other. Cores bottom are composed of 7400yBP huge-tsunami event caused simultaneously by the Kikai-caldera eruption (over 170 cubic km ejecta) is just covered with the Kikai-Akahoya (K-Ah) tephra. The 2K and volcanic tsunami events have also found widely, not only Kii Peninsula but southern Shikoku (Tokushima Pref. and Kochi Pref.) and Kyushu through the Nankai Trough.

Symptoms of anxiety and depression are related to cardiovascular responses to active, but not passive, coping tasks.

PubMed

Yuenyongchaiwat, Kornanong; Baker, Ian S; Sheffield, David

2017-01-01

Anxiety and depression have been linked to blunted blood pressure (BP) and heart rate (HR) reactions to mental stress tests; however, most studies have not included indices of underlying hemodynamics nor multiple stress tasks. This study sought to examine the relationships of anxiety and depression with hemodynamic responses to acute active and passive coping tasks. A total of 104 participants completed the Hospital Anxiety and Depression Scales and mental arithmetic, speech, and cold pressor tasks while BP, HR, total peripheral resistance, and cardiac output (CO) were assessed. After adjustment for traditional risk factors and baseline cardiovascular activity, depression scores were negatively associated with systolic BP, HR, and CO responses to the mental arithmetic task, while anxiety scores were inversely related to the systolic BP response to mental arithmetic. High anxiety or depression scores appear to be associated with blunted cardiac reactions to mental arithmetic (an active coping task), but not to the cold pressor test or speech tasks. Future research should further examine potential mechanisms and longitudinal pathways relating depression and anxiety to cardiovascular reactivity. TCTR20160208004.

Evidence and Perspectives on the 24-hour Management of Hypertension: Hemodynamic Biomarker-Initiated 'Anticipation Medicine' for Zero Cardiovascular Event.

PubMed

Kario, Kazuomi

There are notable differences between Asians and Westerners regarding hypertension (HTN) and the relationship between HTN and cardiovascular disease (CVD). Asians show greater morning surges in blood pressure (BP) and a steeper slope illustrating the link between higher BP and the risk of CVD events. It is thus particularly important for Asian hypertensives to achieve 24-h BP control, including morning and night-time control. There are three components of 'perfect 24-h BP control:' the 24-h BP level, nocturnal BP dipping, and BP variability (BPV), such as the morning BP surge that can be assessed by ambulatory BP monitoring. The morning BP-guided approach using home BP monitoring (HBPM) is the first step toward perfect 24-h BP control, followed by the control of nocturnal HTN. We have been developing new HBPM devices that can measure nocturnal BP. BPV includes different time-phase variability from the shortest beat-by-beat, positional, diurnal, day-by-day, visit-to-visit, seasonal, and yearly changes. The synergistic resonance of each type of BPV would produce a great dynamic BP surge (resonance hypothesis), which triggers a CVD event, especially in the high-risk patients with systemic hemodynamic atherothrombotic syndrome (SHATS). In the future, the innovative management of HTN based on the simultaneous assessment of the resonance of all of the BPV phenotypes using a beat by beat wearable 'surge' BP monitoring device (WSP) and an information and communication technology (ICT)-based data analysis system will produce a paradigm shift from 'dots' BP management to 'seamless' ultimate individualized 'anticipation medication' for reaching a zero CVD event rate. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

Changes in the Indian summer monsoon intensity in Sri Lanka during the last 30 ky - A multiproxy record from a marine sediment core.

NASA Astrophysics Data System (ADS)

Ranasinghage, P. N.; Nanayakkara, N. U.; Kodithuwakku, S.; Siriwardana, S.; Luo, C.; Fenghua, Z.

2016-12-01

Indian monsoon plays a vital role in determining climate events happening in the Asian region. There is no sufficient work in Sri Lanka to fully understand how the summer monsoonal variability affected Sri Lanka during the quaternary. Sri Lanka is situated at an ideal location with a unique geography to isolate Indian summer monsoon record from iris counterpart, Indian winter monsoon. Therefore, this study was carried out to investigate its variability and understand the forcing factors. For this purpose a 1.82 m long gravity core, extracted from western continental shelf off Colombo, Sri Lanka by Shiyan 1 research vessel, was used. Particle size, chemical composition and colour reflectance were measured using laser particle size analyzer at 2 cm resolution, X-Ray Fluorescence spectrometer (XRF) at 2 cm resolution, and color spectrophotometer at 1 cm resolution respectively. Radio carbon dating of foraminifera tests by gas bench technique yielded the sediment age. Finally, principal component analysis (PCA) of XRF and color reflectance (DSR) data was performed to identify groups of correlating elements and mineralogical composition of sediments. Particle size results indicate that Increasing temperature and strengthening monsoonal rainfall after around 18000 yrs BP, at the end of last glacial period, enhanced chemical weathering over physical weathering. Proxies for terrestrial influx (XRF PC1, DSR PC1) and upwelling and nutrient supply driven marine productivity (XRF PC3 and DSR PC2) indicate that strengthening of summer monsoon started around 15000 yrs BP and maximized around 8000-10000 yrs BP after a short period of weakening during Younger Dryas (around 11000 yrs BP). The 8.2 cold event was recorded as a period of low terrestrial influx indicating weakening of rainfall. After that terrestrial input was low till around 2000 yrs BP indicating decrease in rainfall. However, marine productivity remained increasing throughout the Holocene indicating an increase in monsoonal driven upwelling. Authors recorded similar increase in monsoonal wind strength during the late Holocene, with no increase in rainfall in another sediment core extracted from the western continental shelf of Sri Lanka.

Expression Patterns of Three Genes Under Short and Long Term Cold Exposure in Thitarodes pui (Lepidoptera: Hepialidae), A Host of Ophiocordyceps sinensis.

PubMed

Min, Q; Cheng, S Y; Xi, J F; Ma, J; Xin, T R; Xia, B; Zou, Z W

　　BACKGROUND: Thitarodes larvae are the host of the caterpillar fungus Ophiocordyceps sinensis. Low temperature is the main environmental limitation for larvae growth. To better understand the cold adaption process in T. pui larvae, the expression patterns of trehalose-6-phosphate synthase (TpTPS), heat shock protein 70 (TpHSP70), and heat shock protein 90 (TpHSP90) were investigated upon short and long-term exposure to 0°C. The 6th instar T. pui larvae were collected in July 2013. TpTPS was firstly sequenced and expression patterns of TpTPS, TpHSP70 and TpHSP90 were investigated using quantitative PCR. Full-length cDNA of TpTPS was 3,012 bp, with an open reading frame of 2,472 bp and an encoding protein of 823 amino acids. TpTPS up-regulation was induced by cold exposure. TpHSP70 expression is altered by cold exposure, but remained low. TpHSP90 expression was obviously up regulated in long-term cold stimulation. All three genes (TpTPS, TpHSP70 and TpHSP90) have likely contributed to cold tolerance in T. pui larvae, TpTPS and TpHSP90 potentially being more important.

Associations of blood pressure with self-report measures of anger and hostility among black and white men and women.

PubMed

Durel, L A; Carver, C S; Spitzer, S B; Llabre, M M; Weintraub, J K; Saab, P G; Schneiderman, N

1989-01-01

This study examined associations between blood pressure (BP) and dispositional variables pertaining to anger and hostility. Black and White 25- to 44-year old male and female normotensives and unmedicated mild to moderate hypertensives completed four reliable self-report scales--the Cook-Medley Hostility (Ho) Scale, the Trait Anger subscale of the State-Trait Anger Scale (STAS-T), and the Cognitive Anger and Somatic Anger subscales of the Cognitive-Somatic Anger Scale--plus the Framingham Anger Scale and the Harburg Anger Scale. They also engaged in three laboratory tasks--Type A Structured Interview (SI), a video game, and a cold pressor task--that elicit cardiovascular reactivity. Ambulatory BP readings at home and at work were also obtained from most subjects. Blacks had significantly higher Ho and lower STAS-T scores than did Whites. Women reported higher levels of somatic anger than did men. White women showed significant positive correlations between STAS-T and systolic BP (SBP) and diastolic BP (DBP) both at rest in the laboratory and during the SI. Black women revealed significant positive relationships between STAS-T and SBP and DBP at rest in the laboratory and at work as well as with DBP during the cold pressor test. For Black men, cognitive anger and DBP at rest were positively related. In contrast, White men revealed significant negative correlations between Ho scores and SBP at rest and during the video game; these men also showed significant negative relationships between somatic anger and SBP and DBP reactivity during the cold pressor test. Women, but not men, showed significant positive relationships between all four anger measures and ambulatory BP at work. Whereas main effects relating anger and cardiovascular measures were not apparent as a function of race, Blacks demonstrated significantly greater SBP and DBP reactivity than Whites during the cold pressor test, with the converse occurring during the SI. Men demonstrated significantly greater DBP reactivity than women during the video game. The present findings indicate that self-reports on anger/hostility measures and cardiovascular responses to behavioral tasks differ as a function of race but that relationships between anger and BP regulation need to take into account possible race-sex interactions and selection of anger/hostility measures.

Revision of Ernst Antevs' New England Varve Chronology: A Record of Meltwater Production and Southeastern LIS Recession: 18.2-12.5 kyr BP (Invited)

NASA Astrophysics Data System (ADS)

Ridge, J. C.

2013-12-01

New varve cores and 54 radiocarbon ages, have allowed the correction, closure of a gap, calibration, and expansion of Ernst Antevs' (1922) New England Varve Chronology from sediments of glacial Lake Hitchcock and it's successors in the Connecticut Valley of western New England (northeastern U.S.A.). The continuous 5659-yr chronology (18.2-12.5 kyr BP) has been renumbered as the North American Varve Chronology. Glacial varve thickness (18.2-13.7 kyr BP) documents abrupt changes in meltwater production related to varying ablation rate (summer climate) that is linked to ice sheet recession rates and advances, i.e. cold intervals are times of thin varves and slower ice recession or glacial readvances. To take advantage of the varve-climate relationship it is necessary to identify non-climatic events that can cause varve thickness to change. This includes sudden changes in lake level and flood events triggered by the abrupt drainage of tributary glacial lakes. A chronology of ice recession for intervals terminated by four stillstands and readvances of 1-2 century durations have been determined for the Connecticut Valley (from S to N): 50-100 m/yr in northern Connecticut to southern Massachusetts; Chicopee Readvance; 30-40 m/yr in central Mass.; Hatfield event; 80-90 m/yr from northern Mass. to central New Hampshire; North Charlestown end moraines; 300 m/yr to northern N.H.; Littleton Readvance; >300 m/yr to Quebec. Meltwater produced by ice recession of 300 m/yr modeled as a receding 1-bar ice sheet profile (from 100 km up ice near ELA to margin, valley width of 80 km, glacier flow rate of 200 m/yr at ELA) would be a minimum glacial meltwater discharge in the Connecticut Valley of ~90 x 109 m3/yr. This is ~10X the modern Conn. River discharge at Walpole, NH compressed almost entirely to the melt season. Non-glacial varves deposited after ice receded from the basin (13.7-12.5 kyr BP) also document climate change as a result of varve thickness varying with changes in runoff, vegetation, and erosion on a recently deglaciated paraglacial landscape. However, in this case cooling events are recognized by higher sediment input and thicker varves. Comparison of varve thickness records to GISP2 ice core records (δ18O original measurements with GICC05 time scale applied) show that from 15.0-12.5 kyr BP climate changes of decadal and longer scale recorded in both records appear identical in spacing and magnitude. Independent time scales for both records (varve 14C calibration and ice core layer counts) are different by 55 yr (well within time scale uncertainties) when similar features in the two records are matched. Varves and the Greenland ice cores appear to simultaneously record the same regional climate changes or, less likely, there is a consistent offset at all scales. After 15.0 yr BP there appears to have been a link between North Atlantic climate and glacial processes (ablation, meltwater production, and ice recession/advance). Prior to 15.0 kyr BP, glacial events are marked by more subtle changes in varve thickness but there is only a weak relationship between varve thickness and Greenland climate.

Late Holocene forest dynamics in the Gulf of Gaeta (central Mediterranean) in relation to NAO variability and human impact

NASA Astrophysics Data System (ADS)

Di Rita, Federico; Lirer, Fabrizio; Bonomo, Sergio; Cascella, Antonio; Ferraro, Luciana; Florindo, Fabio; Insinga, Donatella Domenica; Lurcock, Pontus Conrad; Margaritelli, Giulia; Petrosino, Paola; Rettori, Roberto; Vallefuoco, Mattia; Magri, Donatella

2018-01-01

A new high-resolution pollen record, spanning the last five millennia, is presented from the Gulf of Gaeta (Tyrrhenian Sea, central Italy), with the aim of verifying if any vegetation change occurred in the central Mediterranean region in relation to specific well-known global and/or regional climate events, including the 4.2 ka event, the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA), and to detect possible vegetation changes related to still under-investigated climate signals, for example the so-called "Bond 2" cold event around 2.8 ka BP. The vegetation dynamics of the Gaeta record shows a recurrent pattern of forest increase and decline punctuating the mid- and late Holocene. When the timing of these patterns is compared with the climate proxy data available from the same core (planktonic foraminifera assemblages and oxygen stable isotope record) and with the NAO (North Atlantic Oscillation) index, it clearly appears that the main driver for the forest fluctuations is climate, which may even overshadow the effects of human activity. We have found a clear correspondence between phases with negative NAO index and forest declines. In particular, around 4200 cal BP, a drop in AP (Arboreal Pollen) confirms the clearance recorded in many sites in Italy south of 43°N. Around 2800 cal BP, a vegetation change towards open conditions is found at a time when the NAO index clearly shows negative values. Between 800 and 1000 AD, a remarkable forest decline, coeval with a decrease in the frequencies of both Castanea and Olea, matches a shift in the oxygen isotope record towards positive values, indicating cooler temperatures, and a negative NAO. Between 1400-1850 AD, in the time period chronologically corresponding to the LIA (Little Ice Age), the Gaeta record shows a clear decline of the forest cover, particularly evident after 1550 AD, once again in correspondence with negative NAO index.

Reproductive Organ and Vascular Specific Promoter of the Rice Plasma Membrane Ca2+ATPase Mediates Environmental Stress Responses in Plants

PubMed Central

Huda, Kazi Md. Kamrul; Banu, Mst. Sufara Akhter; Pathi, Krishna Mohan; Tuteja, Narendra

2013-01-01

Background Plasma membrane Ca2+ATPase is a transport protein in the plasma membrane of cells and helps in removal of calcium (Ca2+) from the cell, hence regulating Ca2+ level within cells. Though plant Ca2+ATPases have been shown to be involved in plant stress responses but their promoter regions have not been well studied. Results The 1478 bp promoter sequence of rice plasma membrane Ca2+ATPase contains cis-acting elements responsive to stresses and plant hormones. To identify the functional region, serial deletions of the promoter were fused with the GUS sequence and four constructs were obtained. These were differentially activated under NaCl, PEG cold, methyl viologen, abscisic acid and methyl jasmonate treatments. We demonstrated that the rice plasma membrane Ca2+ATPase promoter is responsible for vascular-specific and multiple stress-inducible gene expression. Only full-length promoter showed specific GUS expression under stress conditions in floral parts. High GUS activity was observed in roots with all the promoter constructs. The −1478 to −886 bp flanking region responded well upon treatment with salt and drought. Only the full-length promoter presented cold-induced GUS expression in leaves, while in shoots slight expression was observed for −1210 and −886 bp flanking region. The −1210 bp deletion significantly responded to exogenous methyl viologen and abscisic acid induction. The −1210 and −886 bp flanking region resulted in increased GUS activity in leaves under methyl jasmonate treatments, whereas in shoots the −886 bp and −519 bp deletion gave higher expression. Salicylic acid failed to induce GUS activities in leaves for all the constructs. Conclusions The rice plasma membrane Ca2+ATPase promoter is a reproductive organ-specific as well as vascular-specific. This promoter contains drought, salt, cold, methyl viologen, abscisic acid and methyl jasmonate related cis-elements, which regulated gene expression. Overall, the tissue-specificity and inducible nature of this promoter could grant wide applicability in plant biotechnology. PMID:23469243

Association between genetic variants of the ADD1 and GNB3 genes and blood pressure response to the cold pressor test in a Chinese Han population: the GenSalt Study.

PubMed

Wang, Laiyuan; Chen, Shufeng; Zhao, Qi; Hixson, James E; Rao, Dabeeru C; Jaquish, Cashell E; Huang, Jianfeng; Lu, Xiangfeng; Chen, Jichun; Cao, Jie; Li, Jianxin; Li, Hongfan; He, Jiang; Liu, De-Pei; Gu, Dongfeng

2012-08-01

Genetic factors influence blood pressure (BP) response to the cold pressor test (CPT), which is a phenotype related to hypertension risk. We examined the association between variants of the α-adducin (ADD1) and guanine nucleotide binding protein (G protein) β-polypeptide 3 (GNB3) genes and BP response to the CPT. A total of 1998 Han Chinese participants from the Genetic Epidemiology Network of Salt Sensitivity completed the CPT. The area under the curve (AUC) above the baseline BP during the CPT was used to measure the BP response. Twelve single-nucleotide polymorphisms (SNPs) of the ADD1 and GNB3 genes were selected and genotyped. Both single-marker and haplotype association analyses were conducted using linear mixed models. The rs17833172 and rs3775067 SNPs of the ADD1 gene and the rs4963516 SNP of the GNB3 gene were significantly associated with the BP response to CPT, even after adjusting for multiple testing. For the ADD1 gene, the AA genotype of SNP rs17833172 was associated with lower systolic BP (SBP) reactivity (P<0.0001) and faster BP recovery (P=0.0003). The TT genotype of rs3775067 was associated with slower SBP recovery (P=0.004). For the GNB3 gene, the C allele of SNP rs4963516 was associated with faster diastolic BP recovery (P=0.002) and smaller overall AUC (P=0.003). Haplotype analysis indicated that the CCGC haplotype of ADD1 constructed by rs1263359, rs3775067, rs4961 and rs4963 was significantly associated with the BP response to CPT. These data suggest that genetic variants of the ADD1 and GNB3 genes may have important roles in BP response to the CPT. Future studies aimed at replicating these novel findings are warranted.

Association between Blood Pressure Responses to Cold Pressor Test and Dietary Sodium Intervention in the Chinese Population

PubMed Central

Chen, Jing; Gu, Dongfeng; Jaquish, Cashell E.; Chen, Chung-Shiuan; Rao, DC; Liu, Depei; Hixson, James E.; Hamm, L. Lee; Gu, C. Charles; Whelton, Paul K.; He, Jiang

2008-01-01

Background Blood pressure (BP) responses to the cold pressor test (CPT) and to dietary sodium intake might be related to the risk of hypertension. We examined the association between BP responses to the CPT and to dietary sodium and potassium interventions. Methods The CPT and dietary intervention were conducted among 1,906 study participants in rural China. The dietary intervention included three 7-day periods of low-sodium-feeding (51.3 mmol/day), high-sodium-feeding (307.8 mmol/day), and high-sodium-feeding plus potassium-supplementation (60 mmol/day). A total of 9 BP measurements were obtained during the 3-day baseline observation and the last 3 days of each intervention using a random-zero sphygmomanometer. Results BP response to the CPT was significantly associated with BP changes during the sodium and potassium interventions (all p<0.0001). Compared to the lowest quartile of BP response to the CPT, systolic BP changes (95% confident interval) for the top 3 quartiles, respectively, were −2.02 (−2.87, −1.16), −3.17 (−4.05, −2.28), and −5.98 (−6.89, −5.08) mm Hg during the low-sodium intervention. Corresponding systolic BP changes during the high-sodium intervention were 0.40 (−0.36, 1.16), 0.44 (−0.35, 1.22), and 2.30 (1.50, 3.10) mm Hg, and during the potassium-supplementation were −0.26 (−0.99, 0.46), −0.95 (−1.70, −0.20), and −1.59 (−2.36, −0.83) mm Hg, respectively. Conclusions These results indicated that BP response to the CPT was associated with salt-sensitivity and potassium-sensitivity. Furthermore, a low-sodium or high-potassium diet might be more effective to lower BP among individuals with high responses to the CPT. PMID:18779460

Traditional games resulted in post-exercise hypotension and a lower cardiovascular response to the cold pressor test in healthy children

PubMed Central

Rauber, Suliane B.; Boullosa, Daniel A.; Carvalho, Ferdinando O.; de Moraes, José F. V. N.; de Sousa, Ioranny R. C.; Simões, Herbert G.; Campbell, Carmen S. G.

2014-01-01

The present study aimed to verify if blood pressure (BP) reactivity could be reduced through a previous single session of active playing when compared to sedentary leisure. Sixteen pre-pubertal healthy children participated in this study. After familiarization with procedures and anthropometric evaluation, participants performed three sessions in randomized order: (1) 30 min of traditional Brazilian games (PLAY); (2) 30 min of video game playing (DDR); and (3) 30 min of watching TV (TV). Each session lasted 80 min, being 10 min of rest; 30 min of intervention activity; and 40 min of recovery. After recovery, the Cold Pressor Test (CPT) was used for the assessment of acute cardiovascular reactivity. BP was recorded at 30 s and 1 min during the CPT. Analysis of variance showed post-exercise hypotension (PEH) only after PLAY, and that systolic and diastolic BP were significantly increased in all conditions during CPT. However, the magnitude of the CPT-induced BP response was significantly less in PLAY compared to DDR and TV. The PEH observed during recovery and the reduced BP response to CPT following playing traditional games may be due its higher cardiovascular and metabolic demand as was indicated by the increased heart rate, oxygen consumption, and BP. It was concluded that BP reactivity to stress may be reduced through a previous single session of traditional games and that PEH was recorded only after this exercise form. This benefit indicates a potential role of playing strategies for cardiovascular health in childhood. PMID:25009506

Traditional games resulted in post-exercise hypotension and a lower cardiovascular response to the cold pressor test in healthy children.

PubMed

Rauber, Suliane B; Boullosa, Daniel A; Carvalho, Ferdinando O; de Moraes, José F V N; de Sousa, Ioranny R C; Simões, Herbert G; Campbell, Carmen S G

2014-01-01

The present study aimed to verify if blood pressure (BP) reactivity could be reduced through a previous single session of active playing when compared to sedentary leisure. Sixteen pre-pubertal healthy children participated in this study. After familiarization with procedures and anthropometric evaluation, participants performed three sessions in randomized order: (1) 30 min of traditional Brazilian games (PLAY); (2) 30 min of video game playing (DDR); and (3) 30 min of watching TV (TV). Each session lasted 80 min, being 10 min of rest; 30 min of intervention activity; and 40 min of recovery. After recovery, the Cold Pressor Test (CPT) was used for the assessment of acute cardiovascular reactivity. BP was recorded at 30 s and 1 min during the CPT. Analysis of variance showed post-exercise hypotension (PEH) only after PLAY, and that systolic and diastolic BP were significantly increased in all conditions during CPT. However, the magnitude of the CPT-induced BP response was significantly less in PLAY compared to DDR and TV. The PEH observed during recovery and the reduced BP response to CPT following playing traditional games may be due its higher cardiovascular and metabolic demand as was indicated by the increased heart rate, oxygen consumption, and BP. It was concluded that BP reactivity to stress may be reduced through a previous single session of traditional games and that PEH was recorded only after this exercise form. This benefit indicates a potential role of playing strategies for cardiovascular health in childhood.

Stent thrombosis with bioabsorbable polymer drug-eluting stents: insights from the Food and Drug Administration database.

PubMed

Khan, Abdur R; Tripathi, Avnish; Farid, Talha A; Abaid, Bilal; Bhatt, Deepak L; Resar, Jon R; Flaherty, Michael P

2017-11-01

SYNERGY, a bioabsorbable polymer-based, everolimus-eluting stent (BP-DES), recently received regulatory approval in the USA for use in percutaneous coronary interventions. Yet, information on the safety of BP-DES in routine clinical practice is limited. Our aim was to compare the safety of the recently approved BP-DES with current durable polymer drug-eluting stents (DP-DES) by analyzing adverse events, namely, stent thrombosis (ST), reported to the Manufacturer and User Facility Device Experience (MAUDE) database. The MAUDE database requires nationwide mandatory notification for adverse events on devices approved for clinical use. This database was searched for adverse events reported between 1 October 2015 and 25 December 2016, encountered after the placement of either BP-DES or DP-DES. Only those adverse events were included where the exposure period to the stents was comparable after the index procedure. Of all the adverse events reported, the event of interest was ST. A total of 951 adverse events were reported. ST occurred in 48/951 of all events, 31/309 and 17/642 when BP-DES or DP-DES were used, respectively (P=0.00001). Of the 31 ST events with BP-DES, 68% (21/31) occurred within less than or equal to 24 h of the index procedure and 52% (16/31) occurred within less than or equal to 2 h. Our results raise the possibility of an increased risk of ST, particularly early ST (within 24 h), with the recently approved BP-DES. However, because of the inherent limitations of reporting within the MAUDE database, these data merely highlight a potential need for additional surveillance and randomized trials to assess further the safety of the bioabsorbable platform.

Effect of temperature and concentration on benzoyl peroxide bleaching efficacy and benzoic acid levels in whey protein concentrate.

PubMed

Smith, T J; Gerard, P D; Drake, M A

2015-11-01

Much of the fluid whey produced in the United States is a by-product of Cheddar cheese manufacture and must be bleached. Benzoyl peroxide (BP) is currently 1 of only 2 legal chemical bleaching agents for fluid whey in the United States, but benzoic acid is an unavoidable by-product of BP bleaching. Benzoyl peroxide is typically a powder, but new liquid BP dispersions are available. A greater understanding of the bleaching characteristics of BP is necessary. The objective of the study was to compare norbixin destruction, residual benzoic acid, and flavor differences between liquid whey and 80% whey protein concentrates (WPC80) bleached at different temperatures with 2 different benzoyl peroxides (soluble and insoluble). Two experiments were conducted in this study. For experiment 1, 3 factors (temperature, bleach type, bleach concentration) were evaluated for norbixin destruction using a response surface model-central composite design in liquid whey. For experiment 2, norbixin concentration, residual benzoic acid, and flavor differences were explored in WPC80 from whey bleached by the 2 commercially available BP (soluble and insoluble) at 5 mg/kg. In liquid whey, soluble BP bleached more norbixin than insoluble BP, especially at lower concentrations (5 and 10 mg/kg) at both cold (4°C) and hot (50°C) temperatures. The WPC80 from liquid whey bleached with BP at 50°C had lower norbixin concentration, benzoic acid levels, cardboard flavor, and aldehyde levels than WPC80 from liquid whey bleached with BP at 4°C. Regardless of temperature, soluble BP destroyed more norbixin at lower concentrations than insoluble BP. The WPC80 from soluble-BP-bleached wheys had lower cardboard flavor and lower aldehyde levels than WPC80 from insoluble-BP-bleached whey. This study suggests that new, soluble (liquid) BP can be used at lower concentrations than insoluble BP to achieve equivalent bleaching and that less residual benzoic acid remains in WPC80 powder from liquid whey bleached hot (50°C) than cold (4°C), which may provide opportunities to reduce benzoic acid residues in dried whey ingredients, expanding their marketability. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Stressful life events and orthostatic blood pressure recovery in older adults.

PubMed

Feeney, Joanne; Dooley, Cara; Finucane, Ciarán; Kenny, Rose Anne

2015-07-01

The majority of the literature on stress and blood pressure (BP) concerns the increased risk of cardiovascular morbidity and mortality from high BP. Because the sympathetic nervous system is critical to the maintenance of orthostatic BP, it was hypothesized that older adults who have experienced more stressful life events (SLEs) would be more likely to show impaired recovery of BP in response to orthostatic stress. A total of 3,765 participants (Mage = 61.6 years, SD = 8.2; 54% female) from the first wave of The Irish Longitudinal Study on Ageing (TILDA) were included in the current analysis. Exposure to lifetime SLEs was ascertained by self-completion questionnaire, and beat-to-beat orthostatic BP measurement was carried out. Individuals who failed to recover at least 95% of their baseline BP by 60 s post stand were characterized as having impaired orthostatic BP recovery. An independent, dose-response relationship between the number of SLEs reported and the odds of impaired systolic BP recovery was observed after adjustment for covariates (1 event: odds ratio [OR] = 1.19, 95% confidence interval [CI] [0.98, 1.45], p = .078; 2 events: OR = 1.33, 95% CI [1.03, 1.73], p = .031; 3 or more events: OR = 1.56, 95% CI [1.12, 1.73], p = .009). This relationship was not evident for diastolic BP recovery. The reporting of a higher number of SLEs is associated with greater risk of impaired systolic BP recovery from orthostatic stress. Potential clinical implications include an increased risk of cerebral hypoperfusion, which predisposes older adults to falls, faints, and changes in cognitive status. (c) 2015 APA, all rights reserved.

Physiological responses to cold (10° C) in men after six months' practice of yoga exercises

NASA Astrophysics Data System (ADS)

Selvamurthy, W.; Ray, U. S.; Hegde, K. S.; Sharma, R. P.

1988-09-01

A study was conducted on 30 healthy soldiers (age: 40 46 years) to assess the effect of selected yogic exercises (asanas) on some physiological responses to cold exposure. They were randomly divided into two groups of 15 each. One group performed regular physical exercises of physical training (PT), while the other group practised yogic exercises. At the end of 6 months of training, both the groups were exposed together to cold stress at 10°C for 2 h, and the following parameters were periodically monitored during cold exposure: heart rate ( fH), blood pressure ( BP), cardiac output(dot Q_c ), oral temperature (Tor), skin temperature ( T sk), respiratory rate ( fR), minute ventilation(dot V_E ), oxygen consumption(dot V_{O_2 } ), and shivering response by integrated electromyogram (EMG). There were progressive increases in BP, fR,dot V_E ,dot V_{O_2 } , anddot Q_c and decreases in fH, T or and T sk during cold exposure in both the groups. However, the decrease in T or and the increases indot V_{O_2 } anddot V_E were relatively lower ( P<0.01) in the yoga group as compared to the PT group. The shivering response appeared much earlier and was more intense in the PT group. These findings suggest that practice of yoga exercises may improve cold tolerance.

Strengthening of the Eastern Tropical North Pacific Oxygen Minimum Zone during Marine Isotope Stage 3 despite the intensification of Dansgaard-Oeschger and Heinrich events

NASA Astrophysics Data System (ADS)

Choumiline, K.; Lyons, T. W.; Carriquiry, J. D.; Perez-Cruz, L. L.; Raiswell, R.; Beaufort, L.; Rafter, P. A.

2017-12-01

The Eastern Tropical North Pacific (ETNP) is sensitive to climatic changes that either strengthen or weaken the Oxygen Minimum Zone (OMZ). Paleoproxy and model evidence indicate that the shifts from cold stadials (LGM, MIS4) to warm interstadials are often accompanied by sudden sea level rise, intensification of marine productivity and enhanced oceanic anoxia. These intermediate states remain enigmatic, especially with overimposed Dansgaard-Oeschger (DO) oscillations and Heinrich events. We present a high-resolution reconstruction of productivity (Corg, P, Cd, Ni, Ba) and redox (Fe/Al, FeHR/FeT, Mo, V, U) of the ETNP over the last glacial period with special emphasis on the MIS3 transition (roughly 30-60 kyr BP). We found that the OMZ was profoundly anoxic throughout that interval, based on marine sedimentary paleoproxy records. Our spatiotemporal reconstruction shows that the geographic extent of enhanced deoxygenation during the MIS3 not only encompassed the Gulf of California (Alfonso, La Paz and Guaymas Basin), Pacific margin off Mazatlan and Baja California (Soledad Basin), but also California (Santa Barbara Basin) and western Canadian margins. The OMZ achieved its peak strength during 45-60 kyr BP exposed by the highest Mo (35 mg/kg), V (120 mg/kg) and U (13 mg/kg) values, and then commenced weakening and contracting onto the LGM. Marine productivity was also reportedly high during the MIS3, mostly mirroring the redox signals. In contrast, MIS4 and LGM were well-oxygenated and depleted in redox proxies (as low as 4 mg/kg of Mo, 60 mg/kg of V and 4 mg/kg of U). Despite of enhanced anoxia or even euxinia during the MIS3, the effect of cold D-O and Heinrich events was unmistakable. Most of these perturbations corresponded to low export production (low Corg, P, Cd/Al, Ni/Al and Ba/Al) and good ventilation of the ETNP. The recoveries after these events were relatively quick and anoxic conditions were re-established within hundreds of years. As of now, there is no definitive explanation for the mechanisms by which D-O and Heinrich events exert changes in the intensity of ETNP OMZs during the MIS3, but a consensus is building. We will discuss the most popular hypotheses that involve changes in atmospheric and thermohaline circulation, as well as variability in deep-sea nutrients.

Late Holocene Drought Variability in Eastern North America: Evidence From the Peatland Archive

NASA Astrophysics Data System (ADS)

Booth, R. K.; Jackson, S. T.

2006-12-01

Tree-ring based drought chronologies from semi-arid regions of western North America have revealed substantial variability in water balance during the past 1000 years, including episodes of persistent drought more severe than any observed during historical times. Delimitation of regional and continental-scale footprints of these past drought events, including their spatial patterning in humid regions where moisture-sensitive paleoclimate records are scarce, is critical to understanding their dynamics and potential causes. Ombrotrophic peatlands are scattered throughout humid regions of North America at mid-latitudes and represent an underutilized source of multidecadal-scale information on past moisture variations. We are developing a spatial network of peatland-derived paleoclimate and paleoecological records in eastern North America, in an effort to 1) determine whether large, decadal to multidecadal droughts of the past several thousand years were spatially and temporally coherent, 2) assess whether the magnitude of past drought events was sufficient to force ecological change in terrestrial ecosystems, and 3) assess the underlying mechanisms and dynamics of widespread drought in North America. We have completed water-level reconstructions based on testate-amoeba assemblages from two ombrotrophic peatlands in mid-continental North America, Hole in the Bog (NC Minnesota) and Minden Bog (SE Michgian). We also have developed reconstructions from three Sphagnum-dominated kettle peatlands, South Rhody Peatland (NC Michigan), Hornet Peatland (NW Wisconsin), and Irwin Smith Peatland (NE Michigan). Although these kettle peatlands are not truly ombrotrophic, high-magnitude water-table fluctuations should still be attributable to climate variability, and we use these records to supplement our interpretation of regional climate history. Our results indicate that all high-magnitude fluctuations in water balance were spatially extensive, affecting bog-surface moisture conditions throughout the western Great Lakes region. These include a large drought event during the late 16th century and a series of widespread drought events between 1900-1600 BP and 1100- 700 BP. The highest magnitude droughts of the last 2000 years occurred during an interval roughly consistent with the Medieval Warm Period (MWP), with individual drought events centered on 1000 BP, 800 BP, and 700 BP. These droughts were associated with major ecological changes, including abrupt changes in vegetation and fire regime. Tree-ring records from the western United States also document a series of extensive and high-magnitude drought events during this time period, suggesting these droughts affected a large portion of mid-latitude North America. Similarly widespread drought during the last 100 years has been linked to sea surface temperature (SST) anomalies in the adjacent ocean basins, particularly an anomalously warm North Atlantic and mid-latitude Pacific, and an anomalously cold Tropical Pacific. We hypothesize that the widespread droughts apparent in our bog records were related to amplification of a similar spatial mode of moisture variability. Comparison with available proxy SST records provides some support for this hypothesis, although a more extensive network of terrestrial hydroclimate records, derived using consistent methods and proxies, needs to be used in conjunction with the developing network of proxy SST records to fully test this hypothesis.

Molecular cloning of low-temperature-inducible ribosomal proteins from soybean.

PubMed

Kim, Kee-Young; Park, Seong-Whan; Chung, Young-Soo; Chung, Chung-Han; Kim, Jung-In; Lee, Jai-Heon

2004-05-01

Three ribosomal protein genes induced by low-temperature treatment were isolated from soybean. GmRPS13 (742 bp) encodes a 17.1 kDa protein which has 95% identity with the 40S ribosomal protein S13 of Panax ginseng (AB043974). GmRPS6 (925 bp) encodes a 28.1 kDa protein which has 94% identity with the 40S ribosomal protein S6 of Asparagus officinalis (AJ277533). GmRPL37 (494 bp) encodes a 10.7 kDa protein which has 85% identity with the 60S ribosomal protein L37 of Arabidopsis thaliana (AF370216). The expression of these ribosomal protein genes started to increase 3 d after low-temperature treatment, whereas the cold-stress protein src1 was highly induced from the first day. Such late response of these ribosomal protein genes may be due to secondary signals during cold adaptation. The induction of ribosomal protein genes might enhance the translation process or help proper ribosome functioning under low-temperature conditions.

Cardiovascular reactivity to video game predicts subsequent blood pressure increases in young men: The CARDIA study.

PubMed

Markovitz, J H; Raczynski, J M; Wallace, D; Chettur, V; Chesney, M A

1998-01-01

This study was undertaken to determine the relationship between heightened reactivity of blood pressure (BP) during stress and 5-year changes in blood pressure and hypertensive status, using the CARDIA study. A total of 3364 participants (910 white men, 909 white women, 678 black men, and 867 black women), initially 20 to 32 years old and normotensive, were included. Cardiovascular reactivity to psychological stressors (video game and star-tracing tasks for 3 minutes, cold pressor test for 1 minute) was measured in 1987-1988. We then examined reactivity as a predictor of significant BP change (> or = 8 mm Hg, thought to represent a clinically significant increase) over the next 5 years. Logistic regression models were used to control for potential covariates. Significant BP change and the development of hypertension (BP greater than 140/90 or taking medication for hypertension) over the 5-year follow-up were examined in separate analyses. Increased systolic blood pressure (SBP) reactivity to the video game was associated with a significant 5-year SBP increase among the entire cohort, independent of resting SBP (p < .0001). Subsequent analyses showed that this relationship held for men but not for women. Reactivity to the star-tracing task or the cold pressor test did not predict significant BP change. Among black men only, new hypertensives (N = 36) had greater diastolic blood pressure (DBP) reactivity to the video game (p = .01). Although BP reactivity to all physical and mental stressors used in this study did not consistently predict 5-year change in BP in this young cohort, the results indicate that reactivity to a video game stressor predicts 5-year change in BP and early hypertension among young adult men. These findings are consistent with other studies showing the usefulness of stressors producing a primarily beta-adrenergic response in predicting BP change and hypertension. The results may be limited by the shortened initial rest and recovery periods used in the CARDIA protocol.

Favorable effect of aerobic exercise on arterial pressure and aortic pulse wave velocity during stress testing.

PubMed

Milatz, Florian; Ketelhut, Sascha; Ketelhut, Sascha; Ketelhut, Reinhard G

2015-07-01

Increased central pulse wave velocity is a major risk factor for cardiovascular disease. The favorable influence of exercise on arterial stiffness (AS) and blood pressure (BP) has been reported exclusively at rest. The present study investigated the influence of a single bout of acute cycling on AS and BP during recovery and, moreover, during cold pressor stress testing. 32 healthy men (33.7 ± 8 years, BMI 24 ± 2.5 kg/m²) performed a 60 minute endurance exercise on a bicycle ergometer (45 % VO2max). Before and after exercise aortic pulse wave velocity (aPWV) as well as central and peripheral BP were measured non-invasively at rest and at the end of a 2 minute cold pressor test (CPT). Even after 60 minutes of recovery aPWV (- 0.22 ± 0.3 m / sec) was significantly reduced (p < 0.01). Exercise decreased peripheral (- 8 ± 7 mmHg) and central (- 7 ± 8 mmHg) systolic BP as well as peripheral (- 3 ± 5 mmHg) and central (- 4 ± 7 mmHg) diastolic BP (p < 0.01). In comparison to measurements during CPT pre-exercise, there was a significant reduction in aPWV (- 0.19 ± 0.3 m / sec), peripheral (- 6 ± 10 mmHg) and central (- 5 ± 8 mmHg) systolic BP as well as peripheral (- 3 ± 6 mmHg) and central (- 3 ± 6 mmHg) diastolic BP during CPT after exercise (p < 0.01). The present study suggests that acute endurance exercise leads not only to decreased BP but even more reduces aPWV as a measure of AS even after 60 minutes of recovery. In particular, the investigation provides evidence that acute moderate-intensity exercise has a favorable effect on BP and aPWV during stress testing.

Identification of an 18 bp deletion in the TWIST1 gene by CO-amplification at lower denaturation temperature-PCR (COLD-PCR) for non-invasive prenatal diagnosis of craniosynostosis: first case report.

PubMed

Galbiati, Silvia; Stenirri, Stefania; Sbaiz, Luca; Barberis, Marco; Cremonesi, Laura; Restagno, Gabriella; Ferrari, Maurizio

2014-04-01

Non-invasive prenatal diagnosis has found application in a limited number of genetic diseases due to the difficulty in detecting a few copies of fetal mutated sequences in the presence of a large excess of wild-type maternal alleles, even in the case of single-base mutations. We developed conditions for the enrichment of fetal mutated alleles in maternal plasma based on CO-amplification at lower denaturation temperature-PCR (COLD-PCR). In particular, we applied a full COLD-PCR protocol to the identification of a p.A87_G92del mutation in the TWIST1 gene causing craniosynostosis in a couple at risk for the disease. The use of the COLD-PCR protocol coupled with direct sequencing enabled correct identification of the fetal paternally inherited mutated allele, in accordance with the result obtained on DNA extracted from chorionic villi. COLD-PCR proved to be a simple and powerful tool for the identification of minority mutated alleles even in the case of a moderately large deletion (18 bp) and confirmed to be very suitable for non-invasive prenatal diagnosis of a variety of genetic diseases.

The anatomy of Last Glacial Maximum climate variations in south Westland, New Zealand, derived from pollen records

NASA Astrophysics Data System (ADS)

Vandergoes, Marcus J.; Newnham, Rewi M.; Denton, George H.; Blaauw, Maarten; Barrell, David J. A.

2013-08-01

We present pollen records from three sites in south Westland, New Zealand, that document past vegetation and inferred climate change between approximately 30,000 and 15,000 cal. yr BP. Detailed radiocarbon dating of the enclosing sediments at one of those sites, Galway tarn, provides a more robust chronology for the structure and timing of climate-induced vegetation change than has previously been possible in this region. The Kawakawa/Oruanui tephra, a key isochronous marker, affords a precise stratigraphic link across all three pollen records, while other tie points are provided by key pollen-stratigraphic changes which appear to be synchronous across all three sites. Collectively, the records show three episodes in which grassland, interpreted as indicating mostly cold subalpine to alpine conditions, was prevalent in lowland south Westland, separated by phases dominated by subalpine shrubs and montane-lowland trees, indicating milder interstadial conditions. Dating, expressed as a Bayesian-estimated single 'best' age followed in parentheses by younger/older bounds of the 95% confidence modelled age range, indicates that a cold stadial episode, whose onset was marked by replacement of woodland by grassland, occurred between 28,730 (29,390-28,500) and 25,470 (26,090-25,270) cal. yr BP (years before AD, 1950), prior to the deposition of the Kawakawa/Oruanui tephra. Milder interstadial conditions prevailed between 25,470 (26,090-25,270) and 24,400 (24,840-24,120) cal. yr BP and between 22,630 (22,930-22,340) and 21,980 (22,210-21,580) cal. yr BP, separated by a return to cold stadial conditions between 24,400 and 22,630 cal. yr BP. A final episode of grass-dominated vegetation, indicating cold stadial conditions, occurred from 21,980 (22,210-21,580) to 18,490 (18,670-17,950) cal. yr BP. The decline in grass pollen, indicating progressive climate amelioration, was well advanced by 17,370 (17,730-17,110) cal. yr BP, indicating that the onset of the termination in south Westland occurred sometime between ca 18,490 and ca 17,370 cal. yr BP. A similar general pattern of stadials and interstadials is seen, to varying degrees of resolution but generally with lesser chronological control, in many other paleoclimate proxy records from the New Zealand region. This highly resolved chronology of vegetation changes from southwestern New Zealand contributes to the examination of past climate variations in the southwest Pacific region. The stadial and interstadial episodes defined by south Westland pollen records represent notable climate variability during the latter part of the Last Glaciation. Similar climatic patterns recorded farther afield, for example from Antarctica and the Southern Ocean, imply that climate variations during the latter part of the Last Glaciation and the transition to the Holocene interglacial were inter-regionally extensive in the Southern Hemisphere and thus important to understand in detail and to place into a global context.

Effects of Gui Zhi Ma Huang Ge Ban Tang on the TLR7 Pathway in Influenza Virus Infected Mouse Lungs in a Cold Environment.

PubMed

Qin, Hong-Qiong; Shi, Shan-Shan; Fu, Ying-Jie; Yan, Yu-Qi; Wu, Sha; Tang, Xiao-Long; Chen, Xiao-Yin; Hou, Guang-Hui; Jiang, Zhen-You

2018-01-01

We wished to investigate the effects of the traditional Chinese medicine Gui Zhi Ma Huang Ge Ban Tang on controlling influenza A virus (IAV) infection and improving inflammation in mouse lungs. Mice were maintained in normal and cold environments and infected with IAV by intranasal application, respectively. Real-time quantitative polymerase chain reaction was used to measure mRNA expression of TLR7, myeloid differentiation primary response 88 (MyD88), and nuclear factor-kappa B (NF- κ B)p65 in the TLR7 signaling pathway and virus replication in lungs. Western blotting was used to measure expression levels of TLR7, MyD88, and NF- κ B p65 proteins. Flow cytometry was used to detect the proportion of T-helper (Th)1/Th2 and Th17/T-regulatory (Treg) cells. Application of Gui Zhi Ma Huang Ge Ban Tang in influenza-infected mice in a cold environment showed (i) downregulation of TLR7, MyD88, and NF- κ Bp65; (ii) inhibition of transcriptional activities of promoters coding for TLR7, MyD88, and NF- κ Bp65; (iii) reduction in the proportion of Th1/Th2 and Th17/Treg cells. Gui Zhi Ma Huang Ge Ban Tang had a good therapeutic effect on mice infected with IAV, especially in the cold environment. It could reduce lung inflammation in mice significantly and elicit an anti-influenza effect by downregulating expression of the key factors in TLR7 signaling pathway.

Exercise-induced hypertension, cardiovascular events, and mortality in patients undergoing exercise stress testing: a systematic review and meta-analysis.

PubMed

Schultz, Martin G; Otahal, Petr; Cleland, Verity J; Blizzard, Leigh; Marwick, Thomas H; Sharman, James E

2013-03-01

The prognostic relevance of a hypertensive response to exercise (HRE) is ill-defined in individuals undergoing exercise stress testing. The study described here was intended to provide a systematic review and meta-analysis of published literature to determine the value of exercise-related blood pressure (BP) (independent of office BP) for predicting cardiovascular (CV) events and mortality. Online databases were searched for published longitudinal studies reporting exercise-related BP and CV events and mortality rates. We identified for review 12 longitudinal studies with a total of 46,314 individuals without significant coronary artery disease, with total CV event and mortality rates recorded over a mean follow-up of 15.2±4.0 years. After adjustment for age, office BP, and CV risk factors, an HRE at moderate exercise intensity carried a 36% greater rate of CV events and mortality (95% CI, 1.02-1.83, P = 0.039) than that of subjects without an HRE. Additionally, each 10mm Hg increase in systolic BP during exercise at moderate intensity was accompanied by a 4% increase in CV events and mortality, independent of office BP, age, or CV risk factors (95% CI, 1.01-1.07, P = 0.02). Systolic BP at maximal workload was not significantly associated with the outcome of an increased rate of CV, whether analyzed as a categorical (HR=1.49, 95% CI, 0.90-2.46, P = 0.12) or a continuous (HR=1.01, 95% CI, 0.98-1.04, P = 0.53) variable. An HRE at moderate exercise intensity during exercise stress testing is an independent risk factor for CV events and mortality. This highlights the need to determine underlying pathophysiological mechanisms of exercise-induced hypertension.

Differential influence of distinct components of increased blood pressure on cardiovascular outcomes: from the atherosclerosis risk in communities study.

PubMed

Cheng, Susan; Gupta, Deepak K; Claggett, Brian; Sharrett, A Richey; Shah, Amil M; Skali, Hicham; Takeuchi, Madoka; Ni, Hanyu; Solomon, Scott D

2013-09-01

Elevation in blood pressure (BP) increases risk for all cardiovascular events. Nevertheless, the extent to which different indices of BP elevation may be associated to varying degrees with different cardiovascular outcomes remains unclear. We studied 13340 participants (aged 54 ± 6 years, 56% women and 27% black) of the Atherosclerosis Risk in Communities Study who were free of baseline cardiovascular disease. We used Cox proportional hazards models to compare the relative contributions of systolic BP, diastolic BP, pulse pressure, and mean arterial pressure to risk for coronary heart disease, heart failure, stroke, and all-cause mortality. For each multivariable-adjusted model, the largest area under the receiver-operating curve (AUC) and smallest -2 log-likelihood values were used to identify BP measures with the greatest contribution to risk prediction for each outcome. A total of 2095 coronary heart disease events, 1669 heart failure events, 771 stroke events, and 3016 deaths occurred during 18 ± 5 years of follow-up. In multivariable analyses adjusting for traditional cardiovascular risk factors, the BP measures with the greatest risk contributions were the following: systolic BP for coronary heart disease (AUC=0.74); pulse pressure for heart failure (AUC=0.79); systolic BP for stroke (AUC=0.74); and pulse pressure for all-cause mortality (AUC=0.74). With few exceptions, results were similar in analyses stratified by age, sex, and race. Our data indicate that distinct BP components contribute variably to risk for different cardiovascular outcomes.

Rapid Vegetational Change in Coastal North America: The Response to Climate Since the LGM

NASA Technical Reports Server (NTRS)

Peteet, Dorothy; Kneller, Margaret

1999-01-01

The late-glacial interval provided rapid shifts in climate which are mirrored by dramatic vegetational changes in North America. Through a transect of lake and mire sites from Connecticut to Virginia on the east coast and Kodiak Island on the western coast, we trace the warming following the LGM with the response of forests and tundra. A brief cold reversal in Virginia is seen from 12,260 to 12,200. The subsequent longer and extreme Younger Dryas event is marked in the southern New England - New Jersey region by dramatic boreal and deciduous forest changes. In the southeastern US, forests also change rapidly, with hemlock forest expansion suggesting increased moisture. In Kodiak Island, the warm, moist tundra of the Bolling/Allerod is replaced by colder, windswept Empetrum-dominated tundra during the Younger Dryas. The Pleistocene/Holocene shift in vegetation is remarkably pronounced in eastern North America as well as the Alaskan coastline. Response time of vegetation to climate change appears to be on the order of decades throughout these coastal locations, probably because of the proximity of sites to important ecotonal boundaries, and the magnitude of the events. Even in Virginia's Holocene record, a cold reversal inferred from increases in spruce and fir is noted at 7500 C14 yr BP. This response of the forests to a short-lived cooling shows the sensitivity of the biosphere to a rapid climate shifts.

Prevalence of Inadequate Blood Pressure Control Among Veterans After Acute Ischemic Stroke Hospitalization: A Retrospective Cohort

PubMed Central

Roumie, Christianne L.; Ofner, Susan; Ross, Joseph S.; Arling, Greg; Williams, Linda S.; Ordin, Diana L.; Bravata, Dawn M.

2011-01-01

Background Reducing blood pressure (BP) after stroke reduces risk for recurrent events. Our aim was to describe hypertension care among veterans with ischemic stroke including BP control by discharge and over the 6 months post stroke event. Methods and Results The Office of Quality and Performance Stroke Special Study included a systematic sample of veterans hospitalized for ischemic stroke in 2007. We examined BP control (<140/90 mmHg) at discharge excluding those who died, enrolled in hospice, or had unknown discharge disposition (N=3640, 3382 adjusted analysis). The second outcome was BP control (<140/90 mmHg) within 6-months post-stroke, excluding patients who died /readmitted within 30 days, lost to follow-up or did not have a BP recorded (N=2054, 1915 adjusted analysis). The population was white (62.7 %) and male (97.7%); 46.9% were <65 years of age; 29% and 37% had a history of cerebrovascular or cardiovascular disease, respectively. Among the 3640 stroke patients 1573(43%) had their last documented BP prior to discharge >140/90 mmHg. Black race (adjusted OR 0.77 [95% CI 0.65, 0.91]), diabetes (OR 0.73 [95% CI 0.62, 0.86]) and hypertension history (OR 0.51 [95% CI 0.42, 0.63]) were associated with lower odds for controlled BP at discharge. Of the 2054 stroke patients seen within 6 months from their index event, 673 (32.8%) remained uncontrolled. By 6 months post event, neither race nor diabetes was associated with BP control; whereas history of hypertension continued to have lower odds of BP control. For each 10 point increase in systolic BP > 140 mmHg at discharge, odds of BP control within 6 months post discharge decreased by 12% (95% CI (8%, 18%)). Conclusions BP values in excess of national guidelines are common after stroke. Forty three percent of patients were discharged with an elevated BP and 33% remained uncontrolled by 6 months. PMID:21693725

Long-term blood pressure variability in patients with rheumatoid arthritis (RA) and its impact on cardiovascular events and all-cause mortality in RA: a population-based comparative cohort study

PubMed Central

Myasoedova, Elena; Crowson, Cynthia S.; Green, Abigail B.; Matteson, Eric L.; Gabriel, Sherine E.

2014-01-01

Objectives To examine long-term visit-to-visit blood pressure (BP) variability in rheumatoid arthritis (RA) vs non-RA subjects and to assess its impact on cardiovascular events and mortality in RA. Methods Clinic BP measures were collected in a population-based incident cohort of RA patients (1987 ACR criteria met between 1/1/1995 and 1/1/2008) and non-RA subjects. BP variability was defined as within-subject standard deviation (SD) in systolic and diastolic BP. Results Study included 442 RA patients (mean age 55.5 years, 70% females) and 424 non-RA subjects (mean age 55.7 years, 69% females). RA patients had higher visit-to-visit variability in systolic BP (13.8±4.7 mm Hg), than non-RA subjects (13.0±5.2 mm Hg, p=0.004). Systolic BP variability declined after the index date in RA (p<0.001), but not in the non-RA cohort (p=0.73), adjusting for age, sex and calendar year of RA. During the mean follow-up of 7.1 years, 33 cardiovascular events and 57 deaths occurred in RA cohort. Visit-to-visit systolic BP variability was associated with increased risk of cardiovascular events (hazard ratio [HR] per 1 mm Hg increase in BP variability 1.12, 95% confidence interval [CI] 1.01-1.25); diastolic BP variability was associated with all-cause mortality in RA (HR 1.14, 95%CI 1.03-1.27), adjusting for systolic and diastolic BP, body mass index, smoking, diabetes, dyslipidemia, use of antihypertensives. Conclusion Patients with RA had higher visit-to-visit systolic BP variability vs non-RA subjects. There was a significant decline in systolic BP variability after RA incidence. Higher visit-to-visit BP variability was associated with adverse cardiovascular outcomes and all-cause mortality in RA. PMID:24986852

Surface (sea floor) and near-surface (box cores) sediment mineralogy in Baffin Bay as a key to sediment provenance and ice sheet variations

USGS Publications Warehouse

Andrews, John T.; Eberl, D.D.

2011-01-01

To better understand the glacial history of the ice sheets surrounding Baffin Bay and to provide information on sediment pathways, samples from 82 seafloor grabs and core tops, and from seven box cores were subjected to quantitative X-ray diffraction weight percent (wt.%) analysis of the 2000 m) all show an abrupt drop in calcite wt.% (post-5 cal ka BP?) following a major peak in detrital carbonate (mainly dolomite). This dolomite-rich detrital carbonate (DC) event in JR175BC06 is possibly coeval with the Younger Dryas cold event. Four possible glacial-sourced end members were employed in a compositional unmixing algorithm to gain insight into down core changes in sediment provenance at the deep central basin. Estimates of the rates of sediment accumulation in the central basin are only in the range of 2 to 4 cm/cal ka, surprisingly low given the glaciated nature of the surrounding land.

Spatio-temporal dynamics of hydrographic reorganizations and iceberg discharges at the junction between the Northeast Atlantic and Norwegian Sea basins surrounding Heinrich event 4

NASA Astrophysics Data System (ADS)

Wary, Mélanie; Eynaud, Frédérique; Kissel, Catherine; Londeix, Laurent; Rossignol, Linda; Lapuyade, Joanna; Castéra, Marie-Hélène; Billy, Isabelle

2018-01-01

Dansgaard-Oeschger and Heinrich events constitute ones of the most enigmatic features of the last glacial period. Many studies have focused on their characteristic millennial climatic variability, testing atmospheric/cryospheric/oceanic couplings, but major uncertainties and discrepancies still remain. A new scenario, robustly supported by an approach coupling paleoreconstructions and freshwater hosing experiments simulating Heinrich-type perturbations, has recently emerged. Reconciling most of the up to now hypothesized theories, it suggests the occurrence of a regional seesaw between a cooled-down North Atlantic Ocean and warmed-up Nordic Seas during cold atmospheric phases, in relation to enhanced subsurface advection of warm Atlantic waters re-emerging in the Norwegian Sea. The associated ocean warming, thus reaching Nordic basins at a critical location beyond the Faeroe-Shetland sill, is proposed to be involved in the concomitant release of European icebergs. Here we further investigate this promising scenario over the 35-41 ka BP interval by (i) outlining its precise spatial pattern in a crucial area, i.e. the junction between the North Atlantic and the Norwegian Sea close to European ice-sheets, (ii) resolving its very fine temporal and regional evolution during critical transitions associated with the onset of warm advection, i.e. Greenland Interstadial to Greenland Stadial and Greenland Interstadial to Heinrich Stadial, and (iii) assessing its impact on the spatio-temporal dynamic of iceberg discharges from the European and Laurentide ice-sheets during cold stadial episodes especially including Heinrich event 4.

Postglacial diatom-climate responses in a small lake in the Pacific Northwest of North America

NASA Astrophysics Data System (ADS)

Egan, J.; Allott, T. E.; Fletcher, W.

2017-12-01

Understanding the variability of ocean-atmosphere interactions in the Pacific Northwest (PNW) of North America is essential for climate forecasting, particularly variations in the El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). Research suggests that global warming is increasing the frequency of extreme El Niño events, which can have global climatic impacts (e.g. disrupting global weather patterns, affecting ecosystems and agriculture and extreme weather events (flood, drought, bushfires)). A diatom record spanning 14,500 Cal yr BP from Moss Lake, Washington is used to assess Holocene climate change in the PNW including evidence for periodicities related to ocean-atmosphere interactions and/or variations in solar output, and is directly compared to the Moss Lake pollen record. Three climate phases were identified: 1) the Late Pleistocene (until 11,800 Cal yr BP), with a cold climate evidenced by the low abundance of diatoms; 2) the early to mid-Holocene (11,800 - 7500 Cal yr BP), with warm climate, longer growing seasons and shorter periods of ice cover, indicated by the increase of Cyclotella pseudostelligera and decrease of Fragilaria taxa; and 3) the mid-to-late Holocene from 7500 Cal yr BP onwards, with a cooler climate reflected by a decrease in Cyclotella pseudostelligera and an increase in Fragilaria taxa. These climate shifts correlate with the regional and local pollen record. Fluctuations in Cyclotella pseudostelligera and Aulacoseira taxa suggest climatic cycles of varying amplitude throughout. RedFit and Wavelet analyses revealed periodicities of approximately 2000, 1300, and 450 yrs. The 2000 yr cycle is attributed to solar variation; the Hallstatt Oscillation. The 1300 yr and 450 yr cycles are attributed to ENSO and PDO like cycles. The 1300 periodicity is evident throughout the Late Pleistocene and Holocene and reflects shifts from El Niño/positive PDO (weak wind intensity, warm temperature) to La Niña/Negative PDO (high wind intensity, cool temperature). Between 11,800 and 7500 Cal yr BP the cycle amplitudes are reduced and frequency increased reflecting the 450 yr periodicity. Diatom data from Moss Lake provide a sensitive record of climate-related limnological responses and refine our understanding of Holocene climate change in the PNW.

RNA-seq Analysis of Cold and Drought Responsive Transcriptomes of Zea mays ssp. mexicana L.

PubMed

Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei

2017-01-01

The annual Zea mays ssp. mexicana L. is a member of teosinte, a wild relative of the Zea mays spp. mays L. This subspecies has strong growth and regeneration ability, high tiller numbers, high protein and lysine content as well as resistance to many fungal diseases, and it can be effectively used in maize improvement. In this study, we reported a Zea mays ssp. mexicana L. transcriptome by merging data from untreated control (CK), cold (4°C) and drought (PEG2000, 20%) treated plant samples. A total of 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp) were predicted, which code for homologs of near 47% of the published maize proteome. Under cold conditions, 2,232 and 817 genes were up-regulated and down-regulated, respectively, while fewer genes were up-regulated (532) and down-regulated (82) under drought stress, indicating that Zea mays ssp. mexicana L. is more sensitive to the applied cold rather than to the applied drought stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and the ICE1-CBF pathway were up-regulated by both stresses. GA associated genes have been shown to differentially regulate the responses to cold in close subspecies in Zea mays . These findings and the identified functional genes can provide useful clues for improving abiotic stress tolerance of maize.

RNA-seq Analysis of Cold and Drought Responsive Transcriptomes of Zea mays ssp. mexicana L.

PubMed Central

Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei

2017-01-01

The annual Zea mays ssp. mexicana L. is a member of teosinte, a wild relative of the Zea mays spp. mays L. This subspecies has strong growth and regeneration ability, high tiller numbers, high protein and lysine content as well as resistance to many fungal diseases, and it can be effectively used in maize improvement. In this study, we reported a Zea mays ssp. mexicana L. transcriptome by merging data from untreated control (CK), cold (4°C) and drought (PEG2000, 20%) treated plant samples. A total of 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp) were predicted, which code for homologs of near 47% of the published maize proteome. Under cold conditions, 2,232 and 817 genes were up-regulated and down-regulated, respectively, while fewer genes were up-regulated (532) and down-regulated (82) under drought stress, indicating that Zea mays ssp. mexicana L. is more sensitive to the applied cold rather than to the applied drought stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and the ICE1-CBF pathway were up-regulated by both stresses. GA associated genes have been shown to differentially regulate the responses to cold in close subspecies in Zea mays. These findings and the identified functional genes can provide useful clues for improving abiotic stress tolerance of maize. PMID:28223998

Plasma renin and cardiovascular responses to the cold pressor test differ in black and white populations: The SABPA study.

PubMed

Gafane, L F; Schutte, R; Van Rooyen, J M; Schutte, A E

2016-05-01

Low plasma renin levels and augmented cardiovascular reactivity to stress are common in blacks and have been linked to the development of hypertension in this population. We (i) compared cardiovascular and plasma renin reactivity to a cold pressor test between a black and white population; and (ii) investigated the associations between cardiovascular and plasma renin reactivity within the black and white populations. Our population consisted of 153 black and 188 white men and women (age range, 20-65 years). We measured blood pressure (BP), heart rate (HR), stroke volume (SV), total peripheral resistance (TPR), Windkessel arterial compliance, and determined plasma renin levels at rest and during the cold pressor test. Reactivity was calculated for each participant as the percentage change from the resting value. We found lower renin and elevated BP in blacks compared with whites at rest and during stress (both, P<0.001). During stress, HR increased more in blacks (P<0.001), whereas SV (P<0.001) and arterial compliance (P=0.013) decreased more in blacks compared with whites. TPR reactivity was positively associated with renin reactivity in blacks only (β=0.17; P=0.041), while in whites diastolic BP reactivity was positively associated with renin reactivity (β=0.21; P=0.005). Although blacks had suppressed renin levels at rest and during acute stress, vascular resistance reactivity associated positively with renin reactivity only in the black population. These results suggest that low renin levels in blacks during rest and stress are linked to increased peripheral vascular responses to stress, which may contribute to elevated BP in blacks.

Rationale and design for the Asia BP@Home study on home blood pressure control status in 12 Asian countries and regions.

PubMed

Kario, Kazuomi; Tomitani, Naoko; Buranakitjaroen, Peera; Chen, Chen-Huan; Chia, Yook-Chin; Divinagracia, Romeo; Park, Sungha; Shin, Jinho; Siddique, Saulat; Sison, Jorge; Soenarta, Arieska Ann; Sogunuru, Guru Prasad; Tay, Jam Chin; Turana, Yuda; Wang, Ji-Guang; Wong, Lawrence; Zhang, Yuqing; Wanthong, Sirisawat; Hoshide, Satoshi; Kanegae, Hiroshi

2018-01-01

Home blood pressure (BP) monitoring is endorsed in multiple guidelines as a valuable adjunct to office BP measurements for the diagnosis and management of hypertension. In many countries throughout Asia, physicians are yet to appreciate the significant contribution of BP variability to cardiovascular events. Furthermore, data from Japanese cohort studies have shown that there is a strong association between morning BP surge and cardiovascular events, suggesting that Asians in general may benefit from more effective control of morning BP. We designed the Asia BP@Home study to investigate the distribution of hypertension subtypes, including white-coat hypertension, masked morning hypertension, and well-controlled and uncontrolled hypertension. The study will also investigate the determinants of home BP control status evaluated by the same validated home BP monitoring device and the same standardized method of home BP measurement among 1600 or more medicated patients with hypertension from 12 countries/regions across Asia. ©2017 Wiley Periodicals, Inc.

Intra-seasonal Characteristics of Wintertime Extreme Cold Events over South Korea

NASA Astrophysics Data System (ADS)

Park, Taewon; Jeong, Jeehoon; Choi, Jahyun

2017-04-01

The present study reveals the changes in the characteristics of extreme cold events over South Korea for boreal winter (November to March) in terms of the intra-seasonal variability of frequency, duration, and atmospheric circulation pattern. Influences of large-scale variabilities such as the Siberian High activity, the Arctic Oscillation (AO), and the Madden-Julian Oscillation (MJO) on extreme cold events are also investigated. In the early and the late of the winter during November and March, the upper-tropospheric wave-train for a life-cycle of the extreme cold events tends to pass quickly over East Asia. In addition, compared with the other months, the intensity of the Siberian High is weaker and the occurrences of strong negative AO are less frequent. It lead to events with weak amplitude and short duration. On the other hand, the amplified Siberian High and the strong negative AO occur more frequently in the mid of the winter from December to February. The extreme cold events are mainly characterized by a well-organized anticyclonic blocking around the Ural Mountain and the Subarctic. These large-scale circulation makes the extreme cold events for the midwinter last long with strong amplitude. The MJO phases 2-3 which provide a suitable condition for the amplification of extreme cold events occur frequently for November to January when the frequencies are more than twice those for February and March. While the extreme cold events during March have the least frequency, the weakest amplitude, and the shortest duration due to weak impacts of the abovementioned factors, the strong activities of the factors for January force the extreme cold events to be the most frequent, the strongest, and the longest among the boreal winter. Keywords extreme cold event, wave-train, blocking, Siberian High, AO, MJO

Event attribution: Human influence on the record-breaking cold event in January of 2016 in Eastern China

NASA Astrophysics Data System (ADS)

Qian, C.; Wang, J.; Dong, S.; Yin, H.; Burke, C.; Ciavarella, A.; Dong, B.; Freychet, N.; Lott, F. C.; Tett, S. F.

2017-12-01

It is controversial whether Asian mid-latitude cold surges are becoming more likely as a consequence of Arctic warming. Here, we present an event attribution study in mid-latitude Eastern China. A strong cold surge occurred during 21st-25th January 2016 affecting most areas of China, especially Eastern China. Daily minimum temperature (Tmin) records were broken at many stations. The area averaged anomaly of Tmin over the region (20-44N, 100-124E) for this pentad was the lowest temperature recorded since modern meteorological observations started in 1960. This cold event occurred in a background of the warmest winter Tmin since 1960. Given the vast damages caused by this extreme cold event in Eastern China and the previous mentioned controversy, it is compelling to investigate how much anthropogenic forcing agents have affected the probability of cold events with an intensity equal to or larger than the January 2016 extreme event. We use the Met Office Hadley Centre system for Attribution of extreme weather and Climate Events and station observations to investigate the effect of anthropogenic forcings on the likelihood of such a cold event. Anthropogenic influences are estimated to have reduced the likelihood of an extreme cold event in mid-winter with the intensity equal to or stronger than the record of 2016 in Eastern China by about 2/3.

Tree-ring records of near-Younger Dryas time in central North America - Preliminary results from the Lincoln quarry site, central Illinois, USA

USGS Publications Warehouse

Panyushkina, Irina P.; Leavitt, Steven W.; Wiedenhoeft, A.; Noggle, S.; Curry, B.; Grimm, E.

2004-01-01

The abrupt millennial-scale changes associated with the Younger Dryas (YD) event ("chronozone") near the dawn of the Holocene are at least hemispheric, if not global, in extent. Evidence for the YD cold excursion is abundant in Europe but fairly meager in central North America. We are engaged in an investigation of high-resolution environmental changes in mid-North America over several millennia (about 10,000 to 14,000 BP) during the Late Glacial-Early Holocene transition, including the YD interval. Several sites containing logs or stumps have been identified and we are in the process of initial sampling or re-sampling them for this project. Here, we report on a site in central Illinois containing a deposit of logs initially thought to be of YD age preserved in alluvial sands. The assemblage of wood represents hardwood (angiosperm) trees, and the ring-width characteristics are favorable to developing formal tree-ring chronologies. However, 4 new radiocarbon dates indicate deposition of wood may have taken place over at least 8000 14C yr (6000-14,000 BP). This complicates the effort to develop a single floating chronology of several hundred years at this site, but it may provide wood from a restricted region over a long period of time from which to develop a sequence of floating chronologies, the timing of deposition and preservation of which could be related to paleoclimatic events and conditions.

Blood Pressure Reduction and Secondary Stroke Prevention: A Systematic Review and Metaregression Analysis of Randomized Clinical Trials.

PubMed

Katsanos, Aristeidis H; Filippatou, Angeliki; Manios, Efstathios; Deftereos, Spyridon; Parissis, John; Frogoudaki, Alexandra; Vrettou, Agathi-Rosa; Ikonomidis, Ignatios; Pikilidou, Maria; Kargiotis, Odysseas; Voumvourakis, Konstantinos; Alexandrov, Anne W; Alexandrov, Andrei V; Tsivgoulis, Georgios

2017-01-01

Current recommendations do not specifically address the optimal blood pressure (BP) reduction for secondary stroke prevention in patients with previous cerebrovascular events. We conducted a systematic review and metaregression analysis on the association of BP reduction with recurrent stroke and cardiovascular events using data from randomized controlled clinical trials of secondary stroke prevention. For all reported events during each eligible study period, we calculated the corresponding risk ratios to express the comparison of event occurrence risk between patients randomized to antihypertensive treatment and those randomized to placebo. On the basis of the reported BP values, we performed univariate metaregression analyses according to the achieved BP values under the random-effects model (Method of Moments) for those adverse events reported in ≥10 total subgroups of included randomized controlled clinical trials. In pairwise meta-analyses, antihypertensive treatment lowered the risk for recurrent stroke (risk ratio, 0.73; 95% confidence interval, 0.62-0.87; P<0.001), disabling or fatal stroke (risk ratio, 0.71; 95% confidence interval, 0.59-0.85; P<0.001), and cardiovascular death (risk ratio, 0.85; 95% confidence interval, 0.75-0.96; P=0.01). In metaregression analyses, systolic BP reduction was linearly related to the lower risk of recurrent stroke (P=0.049), myocardial infarction (P=0.024), death from any cause (P=0.001), and cardiovascular death (P<0.001). Similarly, diastolic BP reduction was linearly related to a lower risk of recurrent stroke (P=0.026) and all-cause mortality (P=0.009). Funnel plot inspection and Egger statistical test revealed no evidence of publication bias. The extent of BP reduction is linearly associated with the magnitude of risk reduction in recurrent cerebrovascular and cardiovascular events. Strict and aggressive BP control seems to be essential for effective secondary stroke prevention. © 2016 American Heart Association, Inc.

Cold periods and coronary events: an analysis of populations worldwide

PubMed Central

Barnett, A.; Dobson, A.; McElduff, P.; Salomaa, V.; Kuulasmaa, K.; Sans, S.; t for

2005-01-01

Study objective: To investigate the association between cold periods and coronary events, and the extent to which climate, sex, age, and previous cardiac history increase risk during cold weather. Design: A hierarchical analyses of populations from the World Health Organisation's MONICA project. Setting: Twenty four populations from the WHO's MONICA project, a 21 country register made between 1980 and 1995. Patients: People aged 35–64 years who had a coronary event. Main results: Daily rates of coronary events were correlated with the average temperature over the current and previous three days. In cold periods, coronary event rates increased more in populations living in warm climates than in populations living in cold climates, where the increases were slight. The increase was greater in women than in men, especially in warm climates. On average, the odds for women having an event in the cold periods were 1.07 higher than the odds for men (95% posterior interval: 1.03 to 1.11). The effects of cold periods were similar in those with and without a history of a previous myocardial infarction. Conclusions: Rates of coronary events increased during comparatively cold periods, especially in warm climates. The smaller increases in colder climates suggest that some events in warmer climates are preventable. It is suggested that people living in warm climates, particularly women, should keep warm on cold days. PMID:15965137

Environmental and climatic conditions at a potential Glacial refugial site of tree species near the Southern Alpine glaciers. New insights from multiproxy sedimentary studies at Lago della Costa (Euganean Hills, Northeastern Italy)

NASA Astrophysics Data System (ADS)

Kaltenrieder, Petra; Belis, Claudio A.; Hofstetter, Simone; Ammann, Brigitta; Ravazzi, Cesare; Tinner, Willy

2009-12-01

It has been hypothesized that refugia of thermophilous tree species were located in Northern Italy very close to the Alps, though, this hypothesis has yet to be tested thoroughly. In contrast to Central and Southern Italy with its relative wealth of data, only a few fragmentary records are currently available from Northern Italy for the last Glacial (Würm, Weichselian). Our new study site Lago della Costa lies adjacent to the catchment of the megafans of the Alpine forelands and the braided rivers of the Northeastern Po Plain that have so far inhibited the recovery of continuous Glacial and Late-Glacial records. We analyze pollen, plant macrofossils, charcoal and ostracods to reconstruct the vegetation, fire and lake history for the period 33,000-16,000 cal. BP. We compare our data with Glacial records from Southern Europe to discuss similarities and dissimilarities between these potential refugial areas. A comparison with independent paleoclimatic proxies allows to assess potential linkages between environmental and climatic variability. New macrofossil and pollen data at Lago della Costa unambiguously document the local persistence of boreal tree taxa such as Larix decidua and Betula tree species around the study site during the last Glacial. The regular occurrence of pollen of temperate trees in the organic lake sediments (fine-detritus calcareous gyttja) suggests that temperate taxa such as Corylus avellana, Quercus deciduous, Tilia, Ulmus, Fraxinus excelsior, Carpinus, Abies alba and Fagus sylvatica, most likely survived the Last Glacial Maximum (LGM) at favorable sites in the Euganean Hills. The percentage values of temperate trees are comparable with those from Southern Europe (e.g. Monticchio in Southern Italy). We conclude that the Euganean Hills were one of the northernmost refugial areas of temperate taxa in Europe. However, the relative and absolute abundances of pollen of temperate trees are highly variable. Pollen-inferred declines of temperate tree communities (e.g. Quercetum mixtum) and low ostracod-inferred water levels at Lago della Costa correspond to the cold Heinrich events H-2 (LGM; 23,000-19,000 cal. BP) and H-3 (around 28,000 cal. BP), as recorded in the marine sediments of the North Atlantic. Similar patterns of significant temperate tree population collapses during cold Heinrich events are recorded at southern Mediterranean sites (e.g. Monticchio and the Alboran Sea). These findings suggest close linkages between Northern Atlantic and South-Central European climates during the past Glacial.

Blood pressure responses to dietary sodium and potassium interventions and the cold pressor test: the GenSalt replication study in rural North China.

PubMed

Zhao, Qi; Gu, Dongfeng; Chen, Jichun; Li, Jianxin; Cao, Jie; Lu, Fanghong; Guo, Dongshuang; Wang, Renping; Shen, Jinjin; Chen, Jing; Chen, Chung-Shiuan; Mills, Katherine T; Schwander, Karen; Rao, Dabeeru C; He, Jiang

2014-01-01

In the Genetic Epidemiology Network of Salt Sensitivity (GenSalt) study, we observed that blood pressure (BP) responses to dietary sodium and potassium interventions and the cold pressor test (CPT) varied greatly among individuals. We conducted a replication study to confirm our previous findings among 695 study participants. The dietary intervention included a 7-day low sodium (51.3 mmol/day), a 7-day high sodium (307.8 mmol/day), and a 7-day high sodium with potassium supplementation (307.8 mmol sodium and 60 mmol potassium/day). BP measurements were obtained during the baseline and each intervention phase. During the CPT, BP was measured before and at 0, 1, 2, and 4 minutes after the participants immersed their right hand in ice water for 1 minute. Systolic and diastolic BP responses (mean ± SD (range), mm Hg) were 8.1±8.4 (-39.1 to 18.2) and -3.5±5.1 (-25.1 to 11.1) to low sodium, 9.1±8.4 (-13.3 to 33.1) and 4.0±5.4 (-16.0 to 20.7) to high sodium, and -4.6±5.8 (-31.8 to 11.6) and -1.9±4.3 (-16.9 to 14.2) to potassium supplementation, respectively (all P < 0.0001 for comparison with each former phase). The mean maximum systolic and diastolic BP responses to the CPT were 16.5±10.5 (-15.3 to 63.3) and 7.6±6.1 (-8.7 to 39.3), respectively (all P < 0.0001). Our study indicates that there are large variations in BP responses to dietary sodium and potassium interventions and to the CPT among individuals.

Orbital- and Millennial-Scale Changes in the Australasian Monsoon over the Last 470,000 Years

NASA Astrophysics Data System (ADS)

Gagan, M. K.; Ayliffe, L.; Drysdale, R.; Zhao, J.; Griffiths, M. L.; Hellstrom, J.; Dunbar, G.; Hantoro, W.; Edwards, R.; Cheng, H.; Suwargadi, B.

2011-12-01

Speleothem 18O/16O records from China have revealed changes in East Asian monsoon rainfall over the last ~390,000 years (e.g. Wang et al. 2008, Cheng et al. 2010), yet little is known about orbital- and millennial-scale climate change in the 'southern half' of the Australasian monsoon domain. To fill this gap, we aim to build speleothem 18O/16O records for the seasonal monsoon rainfall belt of south-central Indonesia. Between 2006 and 2009, we sampled speleothems in Flores and southwest Sulawesi (latitudes 5-9 S) with U-series ages extending to ~90,000 yBP and ~470,000 yBP, respectively. Development of the 18O/16O records for Sulawesi is in progress, but the basal ages of the speleothems (onset of stalagmite growth) are intriguing because they cluster around glacial terminations, when the East Asian monsoon is known to have been weak (Cheng et al. 2010). There is clear antiphasing of the Flores and China speleothem 18O/16O records on precession time-scales over the last ~90,000 years. A distinct maximum in monsoon rainfall in Flores occurred ~21,000 yBP, suggesting the ITCZ moved south during the Last Glacial Maximum in response to the southern hemisphere summer insolation maximum. This important finding indicates that ITCZ positioning in tropical Australasia, through its influence on large-scale oceanic-atmospheric circulation, could have played a key role in the rapid rise of atmospheric CO2 and global warming that ultimately led to the demise of the ice age, as summarised by Denton et al. (2010) and others. The new Flores speleothem 18O/16O records also show that climate change in the North Atlantic region and Australasian monsoon rainfall are inextricably linked on millennial timescales (Griffiths et al. 2009, Lewis et al. 2011). For example, rapid warming in the North Atlantic region during Dansgaard-Oeschger Event 21 (~86,000 yBP) was linked to a synchronous northward shift of the Australasian ITCZ, marking the final demise of MIS 5b. In contrast, cooling in the North Atlantic during Heinrich Events 3 (~30,000 yBP) and 1 (~16,000 yBP) and the YD (12,800-11,500 yBP) correlates with southward shifts in the Australasian ITCZ. However, the 8,200 yBP cold snap in the North Atlantic produced drying and cooling around Flores. The key difference here is that sea level was relatively high, and cooler sea-surface temperatures in the Indonesian maritime continent at that time (based on nearby coral records) may have suppressed a southward migration of the ITCZ. Cheng, H. et al. (2010), Science, 326, 248-. Denton, G.H. et al. (2010), Science, 328, 1652-. Griffiths, M.L. et al. (2009), Nature Geoscience, 2, 636-. Lewis, S.C. et al. (2011), Earth Planet. Sci. Lett., 303, 133-. Wang, Y. et al. (2008), Nature, 451, 1090-.

Daytime variation in ambient temperature affects skin temperatures and blood pressure: Ambulatory winter/summer comparison in healthy young women.

PubMed

Martinez-Nicolas, Antonio; Meyer, Martin; Hunkler, Stefan; Madrid, Juan Antonio; Rol, Maria Angeles; Meyer, Andrea H; Schötzau, Andy; Orgül, Selim; Kräuchi, Kurt

2015-10-01

It is widely accepted that cold exposure increases peripheral vascular resistance and arterial blood pressure (BP) and, hence, increases cardiovascular risk primarily in the elderly. However, there is a lack of concomitantly longitudinal recordings at personal level of environmental temperature (PET) and cardiophysiological variables together with skin temperatures (STs, the “interface-variable” between the body core and ambient temperature). To investigate the intra-individual temporal relationships between PET, STs and BP 60 healthy young women (52 completed the entire study) were prospectively studied in a winter/summer design for 26 h under real life conditions. The main hypothesis was tested whether distal ST (Tdist)mediates the effect of PET-changes on mean arterial BP (MAP). Diurnal profiles of cardiophysiological variables (including BP), STs and PET were ambulatory recorded. Daytime variations between 0930 and 2030 h were analyzed in detail by intra-individual longitudinal path analysis. Additionally, time segments before, during and after outdoor exposure were separately analyzed. In both seasons short-term variations in PET were positively associated with short-term changes in Tdist (not proximal ST, Tprox) and negatively with those in MAP. However, long-term seasonal differences in daytime mean levels were observed in STs but not in BP leading to non-significant inter-individual correlation between STs and BP. Additionally, higher individual body mass index (BMI) was significantly associated with lower daytime mean levels of Tprox and higher MAP suggesting Tprox as potential mediator variable for the association of BMI with MAP. In healthy young women the thermoregulatory and BP-regulatory systems are closely linked with respect to short-term, but not long-term changes in PET. One hypothetical explanation could serve recent findings that thermogenesis in brown adipose tissue is activated in a cool environment, which could be responsible for the counter-regulation of cold induced increase of BP in winter leading to no seasonal differences in MAP. Our findings suggest that the assessment of diurnal patterns of STs and PET, in addition to the conventional ambulatory BP monitoring, might improve individual cardiovascular risk prediction.

Late Quaternary vegetational and climate dynamics in northeastern Brazil, inferences from marine core GeoB 3104-1

NASA Astrophysics Data System (ADS)

Behling, Hermann; W. Arz, Helge; Pätzold, Jürgen; Wefer, Gerold

2000-06-01

Late Quaternary paleoenvironments from northeastern (NE) Brazil have been studied by pollen analysis of marine sediment. The studied core GeoB 3104-1 (3°40' S, 37°43' W, 767 m b.s.l.) from the upper continental slope off NE Brazil is 517 cm long and >42,000 14C yr BP old. Chronological control was obtained by 12 radiocarbon (AMS) dates from individuals of the foraminiferal species Globigerinoides sacculifer. Modern pollen analogs were received from 15 river, lake and forest soil surface samples from NE Brazil. Marine pollen dates indicate the predominance of semi-arid caatinga vegetation in NE Brazil during the recorded period between >42,000 and 8500 14C yr BP. The increased fluvial input of terrigenous material, with high concentrations of pollen and specially fern spores, into the marine deposits, about 40,000, 33,000 and 24,000 14C yr BP and between 15,500 and 11,800 14C yr BP, indicate short-term periods of strong rainfall on the NE Brazilian continent. The expansion of mountain, floodplain and gallery forests characterize the interval between 15,500 and 11,800 14C yr BP as the wettest recorded period in NE Brazil, which allowed floristic exchanges between Atlantic rain forest and Amazonian rain forest, and vice versa. The paleodata from core GeoB 3104-1 confirm the, in general, dry pre-Last Glacial Maximum (LGM) and LGM conditions and the change to wet Lateglacial environments in tropical South America. The annual movement of the intertropical convergence zone over NE Brazil, the strong influence of the Antarctic cold fronts and changes of the high-pressure cell over the southern Atlantic, may explain the very wet Lateglacial period in NE Brazil. The documented NE Brazilian short-term signals correlate with the documented Dansgaard-Oeschger cycles and Heinrich events from the northern Hemisphere and suggest strong teleconnections.

Psychosocial Factors Are Associated With Blood Pressure Progression Among African Americans in the Jackson Heart Study

PubMed Central

Sims, Mario; Higginbotham, John C.; Crowther, Martha R.; Wyatt, Sharon B.; Musani, Solomon K.; Payne, Thomas J.; Fox, Ervin R.; Parton, Jason M.

2016-01-01

BACKGROUND Research that examines the associations of psychosocial factors with incident hypertension among African Americans (AA) is limited. Using Jackson Heart Study (JHS) data, we examined associations of negative affect and stress with incident hypertension and blood pressure (BP) progression among AA. METHODS Our sample consisted of 1,656 normotensive participants at baseline (2000–2004) (mean age 47±12; 61% women). We investigated associations of negative affect (cynical distrust, anger-in, anger-out, and depressive symptoms) and stress (perceived stress, weekly stress inventory (WSI)-event, WSI-impact, and major life events) with BP progression (an increase by one BP stage as defined by JNC VII) and incident hypertension by examination 2 (2005–2008). Poisson regression analysis was utilized to examine the prevalence ratios (PRs; 95% confidence interval (CI)) of BP tracking and incident hypertension with psychosocial factors, adjusting for baseline age, sex, socioeconomic status (SES), and hypertension risk factors. RESULTS Fifty-six percentage of the sample (922 cases) had BP progression from 2005 to 2008. After adjustment for age, sex, and SES, a high anger-out score was associated with a 20% increased risk of BP progression compared to a low anger-out score (PR 1.20; 95% CI 1.05–1.36). High depressive symptoms score was associated with BP progression in the age, sex, and SES-adjusted model (PR 1.14; 95% CI 1.00–1.30). High WSI-event scores were associated with BP progression in the fully adjusted model (PR 1.21; 95% CI 1.04–1.40). We did not observe significant associations with any of the psychosocial measures and incident hypertension. CONCLUSIONS Psychosocial factors were associated with BP progression, with the strongest evidence for number of stressful events that occurred. PMID:26964661

77 FR 53886 - February 2011 Southwest Cold Weather Event Follow-up Technical Conference; Notice of Technical...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-04

... Southwest Cold Weather Event Follow-up Technical Conference; Notice of Technical Conference Take notice that... August 16, 2011 Report on Outages and Curtailments During the Southwest Cold Weather Event of February 1... severe cold weather issues that led to rolling blackouts affecting over 4 million customers and natural...

Blood pressure targets for hypertension in older adults.

PubMed

Garrison, Scott R; Kolber, Michael R; Korownyk, Christina S; McCracken, Rita K; Heran, Balraj S; Allan, G Michael

2017-08-08

Eight out of 10 major antihypertensive trials in older adults attempted to achieve a target systolic blood pressure (BP) less than 160 mmHg. Collectively these trials demonstrated benefit for treatment, as compared to no treatment, for an older adult with BP greater than 160 mmHg. However an even lower BP target of less than 140 mmHg is commonly applied to all age groups. At the present time it is not known whether a lower or higher BP target is associated with better cardiovascular outcomes in older adults. To assess the effects of a higher (less than 150 to 160/95 to 105 mmHg) BP target compared to the lower BP target of less than 140/90 mmHg in hypertensive adults 65 years of age or older. The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to February 2017: the Cochrane Hypertension Specialised Register, MEDLINE, Embase, ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform. We also contacted authors of relevant papers regarding further published and unpublished work. Randomised trials, of at least one year's duration, conducted on hypertensive adults aged 65 years or older, which report the effect on mortality and morbidity of a higher systolic or diastolic BP treatment target (whether ambulatory, home, or office measurements) in the range of systolic BP less than 150 to 160 mmHg or diastolic BP less than 95 to 105 mmHg as compared to a lower BP treatment target of less than 140/90 mmHg or lower. Two authors independently screened and selected trials for inclusion, assessed risk of bias, and extracted data. We combined data for dichotomous outcomes using the risk ratio (RR) with 95% confidence interval (CI) and for continuous outcomes we used mean difference (MD). Primary outcomes were all-cause mortality, stroke, institutionalisation, and cardiovascular serious adverse events. Secondary outcomes included cardiovascular mortality, non-cardiovascular mortality, unplanned hospitalisation, each component of cardiovascular serious adverse events separately (including cerebrovascular disease, cardiac disease, vascular disease, and renal failure), total serious adverse events, total minor adverse events, withdrawals due to adverse effects, systolic BP achieved, and diastolic BP achieved. We found and included three unblinded randomised trials in 8221 older adults (mean age 74.8 years), in which higher BP targets of less than 150/90 mmHg (two trials) and less than 160/90 mmHg (one trial) were compared to a lower target of less than 140/90 mmHg. Treatment to the two different BP targets over two to four years failed to produce a difference in any of our primary outcomes, including all-cause mortality (RR 1.24 95% CI 0.99 to 1.54), stroke (RR 1.25 95% CI 0.94 to 1.67) and total cardiovascular serious adverse events (RR 1.19 95% CI 0.98 to 1.45). However, the 95% confidence intervals of these outcomes suggest the lower BP target is probably not worse, and might offer a clinically important benefit. We judged all comparisons to be based on low-quality evidence. Data on adverse effects were not available from all trials and not different, including total serious adverse events, total minor adverse events, and withdrawals due to adverse effects. At the present time there is insufficient evidence to know whether a higher BP target (less than150 to 160/95 to 105 mmHg) or a lower BP target (less than 140/90 mmHg) is better for older adults with high BP. Additional good-quality trials assessing BP targets in this population are needed.

Sediment record of environmental change at Lake Lop Nur (Xinjiang, NW China) from 13.0 to 5.6 cal ka BP

NASA Astrophysics Data System (ADS)

Wang, Jingzhong; Jia, Hongjuan

2017-09-01

Lake Lop Nur is located in the eastern part of the Tarim Basin in Xinjiang, northwestern China. A 220-cm-long sediment core was collected from the center of the ear-shaped depression forming the basin and dated with AMS14C. Grain size, total organic matter (TOC), total nitrogen (TN), and TOC/TN (C/N) analyses were used to reconstruct climatic conditions from 13.0 to 5.6 cal ka BP. The results showed five main climatic stages. Zone I (13.0-11.3 cal ka BP) was a wet-dry environment, whereas Zone II (11.3-8.9 cal ka BP) consisted of a primarily wet environment. Zone III (8.9-7.7 cal ka BP) was subdivided into Zone IIIa (8.9-8.2 cal ka BP) that indicated lake constriction and dry climate, and Zone IIIb (8.2-7.7 cal ka BP) in which the proxies indicated wet conditions. In Zone IV (7.7-6.6 cal ka BP), the climate presented a bit wet conditions. In Zone V (6.6-5.6 cal ka BP), abundant glauberite is present in the sediment and silt dominates the lithology; these results indicate the lake shrank and the overall climate was dry. Abrupt environmental events were also identified, including six dry events at 11.0, 10.5, 9.3, 8.6, 8.2, and 7.6 cal ka BP and one flood event from 7.8 to 7.7 cal ka BP in the Early-Middle Holocene.

A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley

USGS Publications Warehouse

Thieler, E. Robert; Butman, Bradford; Schwab, William C.; Allison, Mead A.; Driscoll, Neal W.; Donnelly, John P.; Uchupi, Elazar

2007-01-01

The Hudson Shelf Valley (HSV) is the largest physiographic feature on the U.S. mid-Atlantic continental shelf. The 150-km long valley is the submerged extension of the ancestral Hudson River Valley that connects to the Hudson Canyon. Unlike other incised valleys on the mid-Atlantic shelf, it has not been infilled with sediment during the Holocene. Analyses of multibeam bathymetry, acoustic backscatter intensity, and high-resolution seismic reflection profiles reveal morphologic and stratigraphic evidence for a catastrophic meltwater flood event that formed the modern HSV. The valley and its distal deposits record a discrete flood event that carved 15-m high banks, formed a 120-km2 field of 3- to 6-m high bedforms, and deposited a subaqueous delta on the outer shelf. The HSV is inferred to have been carved initially by precipitation and meltwater runoff during the advance of the Laurentide Ice Sheet, and later by the drainage of early proglacial lakes through stable spillways. A flood resulting from the failure of the terminal moraine dam at the Narrows between Staten Island and Long Island, New York, allowed glacial lakes in the Hudson and Ontario basins to drain across the continental shelf. Water level changes in the Hudson River basin associated with the catastrophic drainage of glacial lakes Iroquois, Vermont, and Albany around 11,450 14C year BP (∼ 13,350 cal BP) may have precipitated dam failure at the Narrows. This 3200 km3 discharge of freshwater entered the North Atlantic proximal to the Gulf Stream and may have affected thermohaline circulation at the onset of the Intra-Allerød Cold Period. Based on bedform characteristics and fluvial morphology in the HSV, the maximum freshwater flux during the flood event is estimated to be ∼ 0.46 Sv for a duration of ∼ 80 days.

The Holocene environmental history of the Verkhoyansk Mountains region (northeastern Siberia, Russia) reconstructed from high-resolution pollen data

NASA Astrophysics Data System (ADS)

Müller, S.; Tarasov, P. E.; Andreev, A. A.; Diekmann, B.

2009-04-01

The study presented here is part of the IPY project 106 "Lake Records of late Quaternary Climate Variability in northeastern Siberia" and the German Research Foundation project RI 809/17-1,2 "Late Quaternary environmental history of interstadial and interglacial periods in the Arctic reconstructed from bioindicators in permafrost sequences in NE Siberia". Both projects focus on generating high-resolution vegetation and climate proxy records mainly from lacustrine sediments along a north-south transect from Yakutia, Republic of Russia. This region is known for its climate extremes, with the Verkhoyansk Mountain Range being the coldest area in the Northern Hemisphere - "Pole of Cold". Radiocarbon-dated pollen records from Lake Billyakh (65°17'N, 126°47'E; 340 m a.s.l.) located in the central part of the Verkhoyansk Mountains were used to reconstruct vegetation and climate changes. The longest and oldest sediment core from the lake reaches back to >30 kyr BP, thus covering the last two Late Pleistocene Interstadials in Siberia. The pollen record and pollen-based biome reconstruction of the core PG 1756, which covers the last 15 kyr BP, suggest that open cool steppe and grass and sedge tundra communities with Poaceae, Cyperaceae, Artemisia, Chenopodiaceae, Caryophyllaceae and Selaginella rupestris dominated the area from 15 to 13.5 kyr BP. On the other hand, the constant presence of Larix pollen in quantities comparable to today's values points to the constant presence of boreal deciduous conifer trees in the regional vegetation during the last glaciation. A major spread of shrub tundra communities, including birch (Betula sect. Nanae), alder (Duschekia fruticosa) and willow (Salix) species, is dated to 13.5-12.7 kyr BP, indicating a noticeable increase in precipitation toward the end of the last glaciation, particularly during the Allerød Interstadial. Between 12.7 and 11.4 kyr BP pollen percentages of herbaceous taxa rapidly increased, whereas shrub taxa percentages decreased, suggesting strengthening of the steppe communities associated with the cold and dry Younger Dryas Stadial. However, the pollen data in hand indicate that Younger Dryas climate was less severe than the climate during the earlier interval from 15 to 13.5 kyr BP. The onset of the Holocene is marked in the pollen record by the highest values of shrub and lowest values of herbaceous taxa, suggesting a return of warmer and wetter conditions after 11.4 kyr BP. Percentages of tree taxa increase gradually and reach maximum values after 7 kyr BP, reflecting the spread of boreal cold deciduous and taiga forests in the region. An interval between 7 and 2 kyr BP is noticeable for the highest percentages of Scots pine (Pinus subgen. Diploxylon), spruce (Picea) and fir (Abies) pollen, indicating mid-Holocene spread of boreal forest communities in response to climate amelioration and degradation of the permafrost layer.

[Adverse Event Trends Associated with Over-the-counter Combination Cold Remedy: Data Mining of the Japanese Adverse Drug Event Report Database].

PubMed

Sasaoka, Sayaka; Hatahira, Haruna; Hasegawa, Shiori; Motooka, Yumi; Fukuda, Akiho; Naganuma, Misa; Umetsu, Ryogo; Nakao, Satoshi; Shimauchi, Akari; Ueda, Natsumi; Hirade, Kouseki; Iguchi, Kazuhiro; Nakamura, Mitsuhiro

2018-01-01

 OTC combination cold remedies are widely used in Japan. In the present study, we aimed to evaluate the adverse event profiles of OTC combination cold remedy based on the components using the Japanese Adverse Drug Event Report (JADER) database. The JADER database contained 430587 reports between April 2004 and November 2016. 1084 adverse events associated with the use of OTC combination cold remedy were reported. Reporting odds ratio (ROR) was used to detect safety signals. The ROR values for "skin and subcutaneous tissue disorders", "hepatobiliary disorders", and "immune system disorders" stratified by system organ class of the Medical Dictionary for Regulatory Activities (MedDRA) were 9.82 (8.71-11.06), 2.63 (2.25-3.07), and 3.13 (2.63-3.74), respectively. OTC combination cold remedy containing acetaminophen exhibited a significantly higher reporting ratio for "hepatobiliary disorders" than OTC combination cold remedy without acetaminophen. We demonstrated the potential risk of OTC combination cold remedy in a real-life setting. Our results suggested that the monitoring of individuals using OTC combination cold remedy is important.

Relative contributions of synoptic and intraseasonal variations to strong cold events over eastern China

NASA Astrophysics Data System (ADS)

Song, Lei; Wu, Renguang; Jiao, Yang

2018-06-01

The present study investigates the relative roles of intraseasonal oscillations (ISOs) and synoptic variations in strong cold events over eastern China during the boreal winter. The ISOs and synoptic variations explain about 55% and 20% of the total area-mean temperature anomaly in eastern China, respectively. The advection of synoptic winds on synoptic temperature gradients has a leading contribution to the temperature decrease before the cold events and thus the synoptic variations are important in determining the time of peak cold anomalies. The ISOs have a larger role in sustaining the cold events. The height anomalies associated with ISOs and synoptic variations are manifested as Rossby wave trains propagating along the polar front jet over the Eurasian continent before the cold events. They both contribute to the deepening of the East Asian trough and the development of cold events. Compared to the ISO wave train, the synoptic wave train has a smaller spatial scale and moves faster. There are obvious intraseasonal signals in the stratosphere about 1 week before the cold events over eastern China. Large negative height anomalies associated with the weakening of the polar vortex are observed over the North Atlantic. These anomalies move eastwards and propagate downwards after reaching the west coast of Europe. The downward moving stratospheric signal triggers height anomalies in the troposphere over the entrance region of the polar front jet. Then the anomalies propagate towards East Asia along the wave train, contributing to the intensification of the Siberian high and the East Asian trough and the occurrence of cold events over eastern China.

Multi-proxy dating of Holocene maar lakes and Pleistocene dry maar sediments in the Eifel, Germany

NASA Astrophysics Data System (ADS)

Sirocko, Frank; Dietrich, Stephan; Veres, Daniel; Grootes, Pieter M.; Schaber-Mohr, Katja; Seelos, Klemens; Nadeau, Marie-Josée; Kromer, Bernd; Rothacker, Leo; Röhner, Marieke; Krbetschek, Matthias; Appleby, Peter; Hambach, Ulrich; Rolf, Christian; Sudo, Masafumi; Grim, Stephanie

2013-02-01

During the last twelve years the ELSA Project (Eifel Laminated Sediment Archive) at Mainz University has drilled a total of about 52 cores from 27 maar lakes and filled-in maar basins in the Eifel/Germany. Dating has been completed for the Holocene cores using 6 different methods (210Pb and 137Cs activities, palynostratigraphy, event markers, varve counting, 14C). In general, the different methods consistently complement one another within error margins. Event correlation was used for relating typical lithological changes with historically known events such as the two major Holocene flood events at 1342 AD and ca 800 BC. Dating of MIS2-MIS3 core sections is based on greyscale tuning, radiocarbon and OSL dating, magnetostratigraphy and tephrochronology. The lithological changes in the sediment cores demonstrate a sequence of events similar to the North Atlantic rapid climate variability of the Last Glacial Cycle. The warmest of the MIS3 interstadials was GI14, when a forest with abundant spruce covered the Eifel area from 55 to 48 ka BP, i.e. during a time when also other climate archives in Europe suggested very warm conditions. The forest of this "Early Stage 3 warm phase" developed subsequently into a steppe with scattered birch and pine, and finally into a glacial desert at around 25 ka BP. Evidence for Mono Lake and Laschamp geomagnetic excursions is found in two long cores. Several large eruptions during Middle and Late Pleistocene (Ulmener Maar - 11,000 varve years BP, Laacher See - 12,900 varve years BP, Mosenberg volcanoes/Meerfelder Maar 41-45 cal ka BP, Dümpel Maar 116 ka BP, Glees Maar - 151 ka BP) produced distinct ash-layers crucial for inter-core and inter-site correlations. The oldest investigated maar of the Eifel is 40Ar/39Ar dated to the time older than 520 ka BP.

Preschool Children with Obstructive Sleep Apnea: The Beginnings of Elevated Blood Pressure?

PubMed Central

Nisbet, Lauren C.; Yiallourou, Stephanie R.; Biggs, Sarah N.; Nixon, Gillian M.; Davey, Margot J.; Trinder, John A.; Walter, Lisa M.; Horne, Rosemary S. C.

2013-01-01

Study Objectives: In adults and older children, snoring and obstructive sleep apnea (OSA) are associated with elevated blood pressure (BP). However, BP has not been assessed in preschool children, the age of highest OSA prevalence. We aimed to assess overnight BP in preschool children with snoring and OSA using pulse transit time (PTT), an inverse continuous indicator of BP changes. Design: Overnight polysomnography including PTT. Children were grouped according to their obstructive apnea-hypopnea index (OAHI); control (no snoring, with OAHI of one event or less per hour), primary snoring (OAHI one event or less per hour), mild OSA (OAHI greater than one event to five events per hour) and moderate-severe OSA (OAHI more than five events per hour). Setting: Pediatric sleep laboratory. Patients: There were 128 clinically referred children (aged 3-5 years) and 35 nonsnoring community control children. Measurement and Results: PTT was averaged for each 30-sec epoch of rapid eye movement (REM) or nonrapid eye movement (NREM) sleep and normalized to each child's mean wake PTT. PTT during NREM was significantly higher than during REM sleep in all groups (P < 0.001 for all). During REM sleep, the moderate-severe OSA group had significantly lower PTT than the mild and primary snoring groups (P < 0.05 for both). This difference persisted after removal of event-related PTT changes. Conclusions: Moderate-severe OSA in preschool children has a significant effect on pulse transit time during REM sleep, indicating that these young children have a higher baseline BP during this state. We propose that the REM-related elevation in BP may be the first step toward development of daytime BP abnormalities. Given that increased BP during childhood predicts hypertension in adulthood, longitudinal studies are needed to determine the effect of resolution of snoring and/or OSA at this age. Citation: Nisbet LC; Yiallourou SR; Biggs SN; Nixon GM; Davey MJ; Trinder JA; Walter LM; Horne RSC. Preschool children with obstructive sleep apnea: the beginnings of elevated blood pressure? SLEEP 2013;36(8):1219-1226. PMID:23904682

Role of cold surge and MJO on rainfall enhancement over indonesia during east asian winter monsoon

NASA Astrophysics Data System (ADS)

Fauzi, R. R.; Hidayat, R.

2018-05-01

Intensity of precipitation in Indonesia is influenced by convection and propagation of southwest wind. Objective of this study is to analyze the relationship between cold surge and the phenomenon of intra-seasonal climate variability Madden-julian Oscillation (MJO) for affecting precipitation in Indonesia. The data used for identifying the occurrence of cold surge are meridional wind speed data from the ERA-Interim. In addition, this study also used RMM1 and RMM2 index data from Bureau of Meteorology (BOM) for identifying MJO events. The results showed that during East Asian Winter Monsoon (EAWM) in 15 years (2000-2015), there are 362 cold surge events, 186 MJO events, and 113 cold surge events were associated with MJO events. The spread of cold surge can penetrate to equator and brought mass of water vapor that causes dominant precipitation in the Indonesian Sea up to 50-75% from climatological precipitation during EAWM. The MJO convection activity that moves from west to east also increases precipitation, but the distribution of rainfall is wider than cold surge, especially in Eastern Indonesia. MJO and cold surge simultaneously can increase rainfall over 100-150% in any Indonesian region that affected by MJO and cold surge events. The mechanism of heavy rainfall is illustrated by high activity of moisture transport in areas such as Java Sea and coastal areas of Indonesia.

The history of South American tropical precipitation for the past 25,000 years.

PubMed

Baker, P A; Seltzer, G O; Fritz, S C; Dunbar, R B; Grove, M J; Tapia, P M; Cross, S L; Rowe, H D; Broda, J P

2001-01-26

Long sediment cores recovered from the deep portions of Lake Titicaca are used to reconstruct the precipitation history of tropical South America for the past 25,000 years. Lake Titicaca was a deep, fresh, and continuously overflowing lake during the last glacial stage, from before 25,000 to 15,000 calibrated years before the present (cal yr B.P.), signifying that during the last glacial maximum (LGM), the Altiplano of Bolivia and Peru and much of the Amazon basin were wetter than today. The LGM in this part of the Andes is dated at 21,000 cal yr B.P., approximately coincident with the global LGM. Maximum aridity and lowest lake level occurred in the early and middle Holocene (8000 to 5500 cal yr B.P.) during a time of low summer insolation. Today, rising levels of Lake Titicaca and wet conditions in Amazonia are correlated with anomalously cold sea-surface temperatures in the northern equatorial Atlantic. Likewise, during the deglacial and Holocene periods, there were several millennial-scale wet phases on the Altiplano and in Amazonia that coincided with anomalously cold periods in the equatorial and high-latitude North Atlantic, such as the Younger Dryas.

A new alternative fuel for reduction of polycyclic aromatic hydrocarbon and particulate matter emissions from diesel engines.

PubMed

Yuan, Chung-Shin; Lin, Hsun-Yu; Lee, Wen-Jhy; Lin, Yuan-Chung; Wu, Tser-Son; Chen, Kung-Fu

2007-04-01

This study investigated the emissions of polycyclic aromatic hydrocarbons (PAHs), carcinogenic potential of PAH and particulate matter (PM), brake-specific fuel consumption (BSFC), and power from diesel engines under transient cycle testing of six test fuels: premium diesel fuel (PDF), B100 (100% palm biodiesel), B20 (20% palm biodiesel + 80% PDF), BP9505 (95% paraffinic fuel + 5% palm biodiesel), BP8020 (80% paraffinic fuel + 20% palm biodiesel), and BP100 (100% paraffinic fuel; Table 1). Experimental results indicated that B100, BP9505, BP8020, and BP100 were much safer when stored than PDF. However, we must use additives so that B100 and BP100 will not gel as quickly in a cold zone. Using B100, BP9505, and BP8020 instead of PDF reduced PM, THC, and CO emissions dramatically but increased CO2 slightly because of more complete combustion. The CO2-increased fraction of BP9505 was the lowest among test blends. Furthermore, using B100, B20, BP9505, and BP8020 as alternative fuels reduced total PAHs and total benzo[a]pyrene equivalent concentration (total BaPeq) emissions significantly. BP9505 had the lowest decreased fractions of power and torque and increased fraction of BSFC. These experimental results implied that BP9505 is feasible for traveling diesel vehicles. Moreover, paraffinic fuel will likely be a new alternative fuel in the future. Using BP9505 instead of PDF decreased PM (22.8%), THC (13.4%), CO (25.3%), total PAHs (88.9%), and total BaPeq (88.1%) emissions significantly.

Prognostic Significance of Blood Pressure Variability on Beat-to-Beat Monitoring After Transient Ischemic Attack and Stroke.

PubMed

Webb, Alastair J S; Mazzucco, Sara; Li, Linxin; Rothwell, Peter M

2018-01-01

Visit-to-visit and day-to-day blood pressure (BP) variability (BPV) predict an increased risk of cardiovascular events but only reflect 1 form of BPV. Beat-to-beat BPV can be rapidly assessed and might also be predictive. In consecutive patients within 6 weeks of transient ischemic attack or nondisabling stroke (Oxford Vascular Study), BPV (coefficient of variation) was measured beat-to-beat for 5 minutes (Finometer), day-to-day for 1 week on home monitoring (3 readings, 3× daily), and on awake ambulatory BP monitoring. BPV after 1-month standard treatment was related (Cox proportional hazards) to recurrent stroke and cardiovascular events for 2 to 5 years, adjusted for mean systolic BP. Among 520 patients, 26 had inadequate beat-to-beat recordings, and 22 patients were in atrial fibrillation. Four hundred five patients had all forms of monitoring. Beat-to-beat BPV predicted recurrent stroke and cardiovascular events independently of mean systolic BP (hazard ratio per group SD, stroke: 1.47 [1.12-1.91]; P =0.005; cardiovascular events: 1.41 [1.08-1.83]; P =0.01), including after adjustment for age and sex (stroke: 1.47 [1.12-1.92]; P =0.005) and all risk factors (1.40 [1.00-1.94]; P =0.047). Day-to-day BPV was less strongly associated with stroke (adjusted hazard ratio, 1.29 [0.97-1.71]; P =0.08) but similarly with cardiovascular events (1.41 [1.09-1.83]; P =0.009). BPV on awake ambulatory BP monitoring was nonpredictive (stroke: 0.89 [0.59-1.35]; P =0.59; cardiovascular events: 1.08 [0.77-1.52]; P =0.65). Despite a weak correlation ( r =0.119; P =0.02), beat-to-beat BPV was associated with risk of recurrent stroke independently of day-to-day BPV (1.41 [1.05-1.90]; P =0.02). Beat-to-beat BPV predicted recurrent stroke and cardiovascular events, independently of mean systolic BP and risk factors but short-term BPV on ambulatory BP monitoring did not. Beat-to-beat BPV may be a useful additional marker of cardiovascular risk. © 2017 The Authors.

Relative sea-level data from southwest Scotland constrain meltwater-driven sea-level jumps prior to the 8.2 kyr BP event

NASA Astrophysics Data System (ADS)

Lawrence, Thomas; Long, Antony J.; Gehrels, W. Roland; Jackson, Luke P.; Smith, David E.

2016-11-01

The most significant climate cooling of the Holocene is centred on 8.2 kyr BP (the '8.2 event'). Its cause is widely attributed to an abrupt slowdown of the Atlantic Meridional Overturning Circulation (AMOC) associated with the sudden drainage of Laurentide proglacial Lakes Agassiz and Ojibway, but model simulations have difficulty reproducing the event with a single-pulse scenario of freshwater input. Several lines of evidence point to multiple episodes of freshwater release from the decaying Laurentide Ice Sheet (LIS) between ∼8900 and ∼8200 cal yr BP, yet the precise number, timing and magnitude of these events - critical constraints for AMOC simulations - are far from resolved. Here we present a high-resolution relative sea level (RSL) record for the period 8800 to 7800 cal yr BP developed from estuarine and salt-marsh deposits in SW Scotland. We find that RSL rose abruptly in three steps by 0.35 m, 0.7 m and 0.4 m (mean) at 8760-8640, 8595-8465, 8323-8218 cal yr BP respectively. The timing of these RSL steps correlate closely with short-lived events expressed in North Atlantic proxy climate and oceanographic records, providing evidence of at least three distinct episodes of enhanced meltwater discharge from the decaying LIS prior to the 8.2 event. Our observations can be used to test the fidelity of both climate and ice-sheet models in simulating abrupt change during the early Holocene.

Acute effects of coffee consumption on self-reported gastrointestinal symptoms, blood pressure and stress indices in healthy individuals.

PubMed

Papakonstantinou, Emilia; Kechribari, Ioanna; Sotirakoglou, Κyriaki; Tarantilis, Petros; Gourdomichali, Theodora; Michas, George; Kravvariti, Vassiliki; Voumvourakis, Konstantinos; Zampelas, Antonis

2016-03-15

It has been suggested that coffee may affect the gut-brain axis with conflicting outcomes. Moreover, there is insufficient evidence to determine whether the type or temperature of coffee consumed will have a different impact on the gut-brain axis. The purpose of this study was to investigate the effects of acute coffee consumption on the following: 1. self-reported GI symptoms and salivary gastrin, 2. stress indices [salivary cortisol and alpha-amylase (sAA)] and psychometric measures, and 3. blood pressure (BP), in healthy, daily coffee consuming individuals in non-stressful conditions. This was a randomized, double blind, crossover clinical trial, in which 40 healthy individuals (20 men, 20 women), 20-55 years of age, randomly consumed four 200 ml coffee beverages containing 160 mg caffeine (hot and cold instant coffee, cold espresso, hot filtered coffee), 1 week apart. Salivary samples and psychometric questionnaires were collected at baseline and post-coffee consumption at 15,30, and 60 min for salivary gastrin and sAA measurements and at 60,120, and 180 min for cortisol measurements. BP was measured at beginning and end of each intervention. ClinicalTrials.gov ID: NCT02253628 RESULTS: Coffee consumption significantly increased sAA activity (P = 0.041), with significant differences only between cold instant and filter coffee at 15 and 30 min post-consumption (P < 0.05). Coffee temporarily increased salivary gastrin, without differences between coffee types. Coffee did not affect salivary cortisol or self-reported anxiety levels. Coffee consumption significantly increased BP, within the healthy physiological levels, in a gender specific manner at the end of the experimental periods, without differences between coffee types. Acute coffee consumption in non-stressful conditions activated sAA and BP but not salivary cortisol, indicating activation of the sympathetic nervous system. Post-coffee sAA increase without a concomitant cortisol increase may also indicate that coffee may have some anti-stress properties.

Response of North American Great Basin Lakes to Dansgaard-Oeschger oscillations

USGS Publications Warehouse

Benson, L.; Lund, S.; Negrini, R.; Linsley, B.; Zic, M.

2003-01-01

We correlate oscillations in the hydrologic and/or cryologic balances of four Great Basin surface-water systems with Dansgaard-Oeschger (D-O) events 2-12. This correlation is relatively strong at the location of the magnetic signature used to link the lake records, but becomes less well constrained with distance/time from the signature. Comparison of proxy glacial and hydrologic records from Owens and Pyramid lakes indicates that Sierran glacial advances occurred during times of relative dryness. If our hypothesized correlation between the lake-based records and the GISP2 ??18O record is correct, it suggests that North Atlantic D-O stades were associated with relatively cold and dry conditions and that interstades were associated with relatively warm and wet conditions throughout the Great Basin between 50,500 and 27,000 GISP2yr B.P. The Great Basin lacustrine climate records reinforce the hypothesis that D-O events affected the climate throughout much of the Northern Hemisphere during marine isotope stages 2 and 3. However, the absolute phasing between lake-size and ice-core ??18O records remains difficult to determine.

Psychosocial Factors Are Associated With Blood Pressure Progression Among African Americans in the Jackson Heart Study.

PubMed

Ford, Cassandra D; Sims, Mario; Higginbotham, John C; Crowther, Martha R; Wyatt, Sharon B; Musani, Solomon K; Payne, Thomas J; Fox, Ervin R; Parton, Jason M

2016-08-01

Research that examines the associations of psychosocial factors with incident hypertension among African Americans (AA) is limited. Using Jackson Heart Study (JHS) data, we examined associations of negative affect and stress with incident hypertension and blood pressure (BP) progression among AA. Our sample consisted of 1,656 normotensive participants at baseline (2000-2004) (mean age 47±12; 61% women). We investigated associations of negative affect (cynical distrust, anger-in, anger-out, and depressive symptoms) and stress (perceived stress, weekly stress inventory (WSI)-event, WSI-impact, and major life events) with BP progression (an increase by one BP stage as defined by JNC VII) and incident hypertension by examination 2 (2005-2008). Poisson regression analysis was utilized to examine the prevalence ratios (PRs; 95% confidence interval (CI)) of BP tracking and incident hypertension with psychosocial factors, adjusting for baseline age, sex, socioeconomic status (SES), and hypertension risk factors. Fifty-six percentage of the sample (922 cases) had BP progression from 2005 to 2008. After adjustment for age, sex, and SES, a high anger-out score was associated with a 20% increased risk of BP progression compared to a low anger-out score (PR 1.20; 95% CI 1.05-1.36). High depressive symptoms score was associated with BP progression in the age, sex, and SES-adjusted model (PR 1.14; 95% CI 1.00-1.30). High WSI-event scores were associated with BP progression in the fully adjusted model (PR 1.21; 95% CI 1.04-1.40). We did not observe significant associations with any of the psychosocial measures and incident hypertension. Psychosocial factors were associated with BP progression, with the strongest evidence for number of stressful events that occurred. © American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Deficits in plasma oxytocin responses and increased negative affect, stress, and blood pressure in mothers with cocaine exposure during pregnancy

PubMed Central

Light, Kathleen C.; Grewen, Karen M.; Amico, Janet A.; Boccia, Maria; Brownley, Kimberly A.; Johns, Josephine M.

2011-01-01

In animals, oxytocin enhances maternal behavior and lowers blood pressure (BP) and negative affect, while parturitional cocaine disrupts oxytocin activity and increases maternal neglect and aggression. Thus, we compared oxytocin, BP, maternal behavior, and affect in mothers of infants who used cocaine (cocaine, n = 10) or did not (no drug, n = 25) during pregnancy. Laboratory BP and circulating oxytocin, catecholamines, and cortisol were examined before and during a speech stressor on 2 days, with vs. without prestress baby holding. Ambulatory monitoring assessed BP, urinary norepinephrine, and cortisol for 24 h at home. The cocaine group had lower oxytocin levels, greater hostility and depressed mood, less support from others and mastery over life events, higher BP during all events of testing without the baby, and higher ambulatory BP and urinary norepinephrine at home, while cortisol and epinephrine responses were blunted. Although they tended to hold their babies less often at home, baby holding in the laboratory led to decreased BP in cocaine mothers who then did not differ from no-drug mothers in BP or observed affect. PMID:15451123

Work More? The 8.2 kaBP Abrupt Climate Change Event and the Origins of Irrigation Agriculture and Surplus Agro-Production in Mesopotamia

NASA Astrophysics Data System (ADS)

Weiss, H.

2003-12-01

The West Asian archaeological record is of sufficient transparency and resolution to permit observation of the social responses to the major Holocene abrupt climate change events at 8.2, 5.2 and 4.2 kaBP. The 8.2kaBP abrupt climate change event in West Asia was a three hundred year aridification and cooling episode. During this period rain-fed agriculture, established for over a millennium in northern Mesopotamia, suddenly collapsed. Irrigation agriculture, pastoral nomadism, or migration were the only subsistence alternatives for populations previously supported by cereal dry-farming. Irrigation agriculture was not, however, possible along the northern alluvial plains of the Tigris and Euphrates Rivers, where incised riverbeds were several meters below plain level. Exploitable plain-level levees were only accessible in southern-most alluvial plain, at the head of the present-day Persian Gulf. The archaeological data from this region documents the first irrigation agriculture settlement of the plain during the 8.2 kaBP event. Irrigation agriculture provides about twice the yield of dry-farming in Mesopotamia, but at considerable labor costs relative to dry-farming. With irrigation agriculture surplus production was now available for deployment. But why work more? The 8.2 kaBP event provided the natural force for Mesopotamian irrigation agriculture and surplus production that were essential for the earliest class-formation and urban life.

Orbital- and Millennial-Scale Changes in the Australasian Monsoon Through the Late Pleistocene

NASA Astrophysics Data System (ADS)

Gagan, M. K.; Ayliffe, L. K.; Scroxton, N. G.; Krause, C. E.; Kimbrough, A. K.; Hantoro, W. S.; Drysdale, R.; Hellstrom, J.; Cheng, H.; Edwards, R.; Zhao, J.; Griffiths, M. L.

2012-12-01

Speleothem 18O/16O records from China and Borneo have revealed changes in Asian monsoon rainfall over the last ~570,000 years (e.g. Wang et al. 2008, Cheng et al. 2010, Meckler et al. 2012), yet little is known about orbital- and millennial-scale climate change in the 'southern half' of the Australasian monsoon domain. To fill this gap, we aim to build speleothem 18O/16O records for the seasonal monsoon rainfall belt of south-central Indonesia. Between 2006 and 2011, we sampled speleothems in Flores and southwest Sulawesi (latitudes 5-9oS) with U-series ages extending to 92,000 yBP and ~470,000 yBP, respectively. Development of the 18O/16O records for Sulawesi is in progress, but the basal ages of the speleothems (onset of stalagmite growth) are intriguing because they cluster around glacial terminations, when the East Asian monsoon is known to have been weak (Cheng et al. 2010). There is clear antiphasing of the Flores and China speleothem 18O/16O records on precession time-scales over the last ~90,000 years. A distinct maximum in monsoon rainfall in Flores occurred ~21,000 yBP, suggesting the ITCZ moved south during the Last Glacial Maximum in response to the southern hemisphere summer insolation maximum. This finding indicates that ITCZ positioning in tropical Australasia, through its influence on large-scale oceanic-atmospheric circulation, could have played a key role in the rapid rise of atmospheric CO2 and global warming that ultimately led to the demise of the last ice age, as summarised by Denton et al. (2010) and others. The new Flores speleothem 18O/16O records also show that climate change in the North Atlantic region and Australasian monsoon rainfall are inextricably linked on millennial timescales (Griffiths et al. 2009, Lewis et al. 2011). For example, rapid warming in the North Atlantic region during Dansgaard-Oeschger Event 21 (~86,000 yBP) was linked to a synchronous northward shift of the Australasian ITCZ, marking the final demise of MIS 5b. In contrast, cooling in the North Atlantic during Heinrich Events 3 (~30,000 yBP) and 1 (~16,000 yBP) and the YD (12,800-11,500 yBP) correlates with southward shifts in the Australasian ITCZ. However, the 8,200 yBP cold snap in the North Atlantic produced drying and cooling around Flores. The key difference here is that sea level was relatively high, and cooler sea-surface temperatures in the Indonesian maritime continent at that time (based on nearby coral records) may have suppressed a southward migration of the ITCZ. Cheng, H. et al. (2010), Science, 326, 248-. Denton, G.H. et al. (2010), Science, 328, 1652-. Griffiths, M.L. et al. (2009), Nature Geoscience, 2, 636-. Lewis, S.C. et al. (2011), Earth Planet. Sci. Lett., 303, 133-. Meckler et al. (2012), Science, 336, 1301-. Wang, Y. et al. (2008), Nature, 451, 1090-.

Validity and Usefulness of `Wearable Blood Pressure Sensing' for Detection of Inappropriate Short-Term Blood Pressure Variability in the Elderly

NASA Astrophysics Data System (ADS)

Iijima, Katsuya; Kameyama, Yumi; Akishita, Masahiro; Ouchi, Yasuyoshi; Yanagimoto, Shintaro; Imai, Yasushi; Yahagi, Naoki; Lopez, Guillaume; Shuzo, Masaki; Yamada, Ichiro

An increase in short-term blood pressure (BP) variability is a characteristic feature in the elderly. It makes the management of hemodynamics more difficult, because it is frequently seen disturbed baro-reflex function and increased arterial stiffness, leading to isolated systolic hypertension. Large BP variability aggravates hypertensive target organ damage and is an independent risk factor for the cardiovascular (CV) events in elderly hypertensive patients. Therefore, appropriate control in BP is indispensable to manage lifestyle-related diseases and to prevent subsequent CV events. In addition, accumulating recent reports show that excessive BP variability is also associated with a decline in cognitive function and fall in the elderly. In the clinical settings, we usually evaluate their health condition, mainly with single point BP measurement using cuff inflation. However, unfortunately we are not able to find the close changes in BP by the traditional way. Here, we can show our advantageous approach of continuous BP monitoring using newly developing device `wearable BP sensing' without a cuff stress in the elderly. The new device could reflect systolic BP and its detailed changes, in consistent with cuff-based BP measurement. Our new challenge suggests new possibility of its clinical application with high accuracy.

Role of Shp2 in forebrain neurons in regulating metabolic and cardiovascular functions and responses to leptin.

PubMed

do Carmo, J M; da Silva, A A; Sessums, P O; Ebaady, S H; Pace, B R; Rushing, J S; Davis, M T; Hall, J E

2014-06-01

We examined whether deficiency of Src homology 2 containing phosphatase (Shp2) signaling in forebrain neurons alters metabolic and cardiovascular regulation under various conditions and if it attenuates the anorexic and cardiovascular effects of leptin. We also tested whether forebrain Shp2 deficiency alters blood pressure (BP) and heart rate (HR) responses to acute stress. Forebrain Shp2(-/-) mice were generated by crossing Shp2(flox/flox) mice with CamKIIα-cre mice. At 22-24 weeks of age, the mice were instrumented for telemetry for measurement of BP, HR and body temperature (BT). Oxygen consumption (VO2), energy expenditure and motor activity were monitored by indirect calorimetry. Shp2/CamKIIα-cre mice were heavier (46±3 vs 32±1 g), hyperglycemic, hyperleptinemic, hyperinsulinemic and hyperphagic compared to Shp2(flox/flox) control mice. Shp2/CamKIIα-cre mice exhibited reduced food intake responses to fasting/refeeding and impaired regulation of BT when exposed to 15 and 30 °C ambient temperatures. Despite being obese and having many features of metabolic syndrome, Shp2/CamKIIα-cre mice had similar daily average BP and HR compared to Shp2(flox/flox) mice (112±2 vs 113±1 mm Hg and 595±34 vs 650±40 b.p.m.), but exhibited increased BP and HR responses to cold exposure and acute air-jet stress test. Leptin's ability to reduce food intake and to raise BP were markedly attenuated in Shp2/CamKIIα-cre mice. These results suggest that forebrain Shp2 signaling regulates food intake, appetite responses to caloric deprivation and thermogenic control of body temperature during variations in ambient temperature. Deficiency of Shp2 signaling in the forebrain is associated with augmented cardiovascular responses to cold and acute stress but attenuated BP responses to leptin.

What should be the optimal levels of blood pressure: Does the J-curve phenomenon really exist?

PubMed

Banach, Maciej; Michalska, Marta; Kjeldsen, Sverre E; Małyszko, Jolanta; Mikhailidis, Dimitri P; Rysz, Jacek

2011-08-01

The blood pressure (BP) J-curve debate has lasted for over 30 years and we still cannot definitively answer all the questions. However, recent studies suggest that BP should be reduced carefully in patients with hypertension and coronary artery disease. BP should not fall below 110 - 115/70 - 75 mmHg, because this may be associated with more cardiovascular events. A retrospective analysis of the INVEST Trial and the results of the BP arm of the ACCORD Trial shows that care is needed in patients with hypertension and diabetes. Although the ACCORD BP Trial suggests important benefits connected with the significant reduction of stroke in patients being treated intensively, it also shows the lack of advantage of such therapy on each main and other additional endpoints. The ACCORD Trial also confirmed the increased risk of adverse events that might appear when intensive treatment was used in this group of patients. Most available studies were observational and randomized trials (BBB, HOT, ACCORD BP), do not have or have lost their statistical power and were inconclusive. Further studies are therefore needed to provide definitive conclusions on the subject. In the meantime, it seems that in high-risk patients with hypertension, it is necessary to carefully select those who might suffer adverse events and those who may benefit from intensive BP lowering.

Insights from a synthesis of old and new climate-proxy data from the Pyramid and Winnemucca lake basins for the period 48 to 11.5 cal ka

USGS Publications Warehouse

Benson, Larry; Smoot, J.P.; Lund, S.P.; Mensing, S.A.; Foit, F.F.; Rye, R.O.

2013-01-01

A synthesis of old and new paleoclimatic data from the Pyramid and Winnemucca lake basins indicates that, between 48.0 and 11.5·103 calibrated years BP (hereafter ka), the climate of the western Great Basin was, to a degree, linked with the climate of the North Atlantic. Paleomagnetic secular variation (PSV) records from Pyramid Lake core PLC08-1 were tied to the GISP2 ice-core record via PSV matches to North Atlantic sediment cores whose isotopic and(or) carbonate records could be linked to the GISP2 δ18O record. Relatively dry intervals in the western Great Basin were associated with cold Heinrich events and relatively wet intervals were associated with warm Dansgaard-Oeschger (DO) oscillations. The association of western Great Basin dry events with North Atlantic cold events (and vice versa) switched sometime after the Laurentide Ice Sheet (LIS) reached its maximum extent. For example, the Lahontan highstand, which culminated at 15.5 ka, and a period of elevated lake level between 13.1 and 11.7 ka were associated with cold North Atlantic conditions, the latter period with the Youngest Dryas event. Relatively dry periods were associated with the Bølling and Allerød warm events. A large percentage of the LIS may have been lost to the North Atlantic during Heinrich events 1 and 2 and may have resulted in the repositioning of the Polar Jet Stream over North America. The Trego Hot Springs, Wono, Carson Sink, and Marble Bluff tephras found in core PLC08-1 have been assigned GISP2 calendar ages of respectively, 29.9, 33.7, 34.1, and 43.2 ka. Given its unique trace-element chemistry, the Carson Sink Bed is the same as Wilson Creek Ash 15 in the Mono Lake Basin. This implies that the Mono Lake magnetic excursion occurred at approximately 34 ka and it is not the Laschamp magnetic excursion. The entrance of the First Americans into the northern Great Basin is dated to approximately 14.4 ka, a time when the climate was relatively dry. Evidence for human occupation of the Great Basin is lacking for the next 1100 years (y); i.e., the oldest western stemmed point site in the Great Basin dates to 13.3 ka. Two hypotheses are suggested for this cultural hiatus: (1) the climate had deteriorated to the point that people vacated the Great Basin, or (2) people moved to basin-bottom wetlands that persisted during the dry period, and then the subsequent Younger Dryas wet event erased the archaeological evidence deposited around the low-elevation wetland sites.

Tropical Pacific climate variability over the last 6000 years as recorded in Bainbridge Crater Lake, Galápagos

NASA Astrophysics Data System (ADS)

Thompson, Diane M.; Conroy, Jessica L.; Collins, Aaron; Hlohowskyj, Stephan R.; Overpeck, Jonathan T.; Riedinger-Whitmore, Melanie; Cole, Julia E.; Bush, Mark B.; Whitney, H.; Corley, Timothy L.; Kannan, Miriam Steinitz

2017-08-01

Finely laminated sediments within Bainbridge Crater Lake, Galápagos, provide a record of El Niño-Southern Oscillation (ENSO) events over the Holocene. Despite the importance of this sediment record, hypotheses for how climate variability is preserved in the lake sediments have not been tested. Here we present results of long-term monitoring of the local climate and limnology and a revised interpretation of the sediment record. Brown-green, organic-rich, siliciclastic laminae reflect warm, wet conditions typical of El Niño events, whereas carbonate and gypsum precipitate during cool, dry La Niña events and persistent dry periods, respectively. Applying this new interpretation, we find that ENSO events of both phases were generally less frequent during the mid-Holocene ( 6100-4000 calendar years B.P.) relative to the last 1500 calendar years. Abundant carbonate laminations between 3500 and 3000 calendar years B.P. imply that conditions in the Galápagos region were cool and dry during this period when the tropical Pacific E-W sea surface temperature (SST) gradient likely strengthened. The frequency of El Niño and La Niña events then intensified dramatically around 1750-2000 calendar years B.P., consistent with a weaker SST gradient and an increased frequency of ENSO events in other regional records. This strong interannual variability persisted until 700 calendar years B.P., when ENSO-related variability at the lake decreased as the SST gradient strengthened. Persistent, dry conditions then dominated between 300 and 50 calendar years B.P. (A.D. 1650-1900, ± 100 years), whereas wetter conditions and frequent El Niño events dominated in the most recent century.

A Storegga age turbidite at Eirik Drift, South Greenland: evidence for synchronous turbidite deposition at 8.2 ka BP in the North Atlantic?

NASA Astrophysics Data System (ADS)

Watts, Millie; Taylor, Vicki; Talling, Peter; Hunt, James; Stanford, Jennifer

2016-04-01

Eirik Drift contains a high-resolution record of climatic and oceanic variability. In addition, it records several submarine landslides throughout the Holocene. Submarine landslides and associated tsunamis are potentially damaging, and have the potential to travel significant distances across the North Atlantic. Two cores taken from Eirik Drift (D298-P2) show an expanded Holocene section of hemipelagite and contain a fine grained turbidite dated to 8.17 ka BP (+/- 200 years). This event is coincident with both the 8.2 ka BP climatic anomaly, and the Storegga Slide. Paleoenvironmental proxies suggest this 8.2 ka BP turbidite was deposited during the coldest part of the 8.2 ka BP event, interpreted here as a longer duration cooling. This Holocene Storegga Slide triggered a major tsunami, evidence of which has been found across Northern European coastlines and the East Greenland coast. Here we show that the 8.2 ka BP turbidite has a different provenance both to other turbidites within the D298 core, and the main body of the Storegga Slide turbidite, and is unique within the Eirik Drift sequence. We interpret this event within the core as a distal deposit of a turbidite transported within the Western boundary Under Current, potentially related to a more northerly Greenland impact of the Storegga Tsunami. The fine-grained nature of the deposit suggests significant transport, supporting the hypothesis this event relates to a Greenland impact of the Storegga Tsunami.

Effect of temperature and bleaching agent on bleaching of liquid Cheddar whey.

PubMed

Listiyani, M A D; Campbell, R E; Miracle, R E; Barbano, D M; Gerard, P D; Drake, M A

2012-01-01

The use of whey protein as an ingredient in foods and beverages is increasing, and thus demand for colorless and mild-tasting whey protein is rising. Bleaching is commonly applied to fluid colored cheese whey to decrease color, and different temperatures and bleach concentrations are used. The objectives of this study were to compare the effects of hot and cold bleaching, the point of bleaching (before or after fat separation), and bleaching agent on bleaching efficacy and volatile components of liquid colored and uncolored Cheddar whey. First, Cheddar whey was manufactured, pasteurized, fat-separated, and subjected to one of a number of hot (68°C) or cold (4°C) bleaching applications [hydrogen peroxide (HP) 50 to 500 mg/kg; benzoyl peroxide (BP) 25 to 100 mg/kg] followed by measurement of residual norbixin and color by reflectance. Bleaching agent concentrations were then selected for the second trial. Liquid colored Cheddar whey was manufactured in triplicate and pasteurized. Part of the whey was collected (no separation, NSE) and the rest was subjected to fat separation (FSE). The NSE and FSE wheys were then subdivided and bleaching treatments (BP 50 or 100 mg/kg and HP 250 or 500 mg/kg) at 68°C for 30 min or 4°C for 16 h were applied. Control NSE and FSE with no added bleach were also subjected to each time-temperature combination. Volatile compounds from wheys were evaluated by gas chromatography-mass spectrometry, and norbixin (annatto) was extracted and quantified to compare bleaching efficacy. Proximate analysis, including total solids, protein, and fat contents, was also conducted. Liquid whey subjected to hot bleaching at both concentrations of HP or at 100mg/kg BP had greater lipid oxidation products (aldehydes) compared with unbleached wheys, 50mg/kg BP hot-bleached whey, or cold-bleached wheys. No effect was detected between NSE and FSE liquid Cheddar whey on the relative abundance of volatile lipid oxidation products. Wheys bleached with BP had lower norbixin content compared with wheys bleached with HP. Bleaching efficacy of HP was decreased at 4°C compared with 68°C, whereas that of BP was not affected by temperature. These results suggest that fat separation of liquid Cheddar whey has no effect on bleaching efficacy or lipid oxidation and that hot bleaching may result in increased lipid oxidation in fluid whey. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Late Quaternary glaciation history of monsoon-dominated Dingad basin, central Himalaya, India

NASA Astrophysics Data System (ADS)

Shukla, Tanuj; Mehta, Manish; Jaiswal, Manoj K.; Srivastava, Pradeep; Dobhal, D. P.; Nainwal, H. C.; Singh, Atul K.

2018-02-01

The study presents the Late Quaternary glaciation history of monsoon-dominated Dokriani Glacier valley, Dingad basin, central Himalaya, India. The basin is tested for the mechanism of landforms preservation in high relief and abundant precipitation regimes of the Higher Himalaya. Field geomorphology and remote sensing data, supported by Optical Stimulated Luminescence (OSL) dating enabled identification of five major glacial events of decreasing magnitude. The oldest glacial stage, Dokriani Glacial Stage I (DGS-I), extended down to ∼8 km (2883 m asl) from present-day snout (3965 m asl) followed by other four glaciations events viz. DGS-II, DGS-III, DGS-IV and DGS-V terminating at ∼3211, 3445, 3648 and ∼3733 m asl respectively. The DGS-I glaciation (∼25-∼22 ka BP) occurred during early Marine Isotope Stage (MIS) -2, characterized as Last Glacial Maximum (LGM) extension of the valley. Similarly, DGS-II stage (∼14-∼11 ka BP) represents the global cool and dry Older Dryas and Younger Dryas event glaciation. The DGS-III glaciation (∼8 ka BP) coincides with early Holocene 8.2 ka cooling event, the DGS-IV glaciations (∼4-3.7 ka BP) corresponds to 4.2 ka cool and drier event, DGS-V (∼2.7-∼1 ka BP) represents the cool and moist late Holocene glacial advancement of the valley. This study suggests that the Dokriani Glacier valley responded to the global lowering of temperature and variable precipitation conditions. This study also highlights the close correlation between the monsoon-dominated valley glaciations and Northern Hemisphere cooling events influenced by North Atlantic climate.

Evolution via recombination: Cell-to-cell contact facilitates larger recombination events in Streptococcus pneumoniae.

PubMed

Cowley, Lauren A; Petersen, Fernanda C; Junges, Roger; Jimson D Jimenez, Med; Morrison, Donald A; Hanage, William P

2018-06-01

Homologous recombination in the genetic transformation model organism Streptococcus pneumoniae is thought to be important in the adaptation and evolution of this pathogen. While competent pneumococci are able to scavenge DNA added to laboratory cultures, large-scale transfers of multiple kb are rare under these conditions. We used whole genome sequencing (WGS) to map transfers in recombinants arising from contact of competent cells with non-competent 'target' cells, using strains with known genomes, distinguished by a total of ~16,000 SNPs. Experiments designed to explore the effect of environment on large scale recombination events used saturating purified donor DNA, short-term cell assemblages on Millipore filters, and mature biofilm mixed cultures. WGS of 22 recombinants for each environment mapped all SNPs that were identical between the recombinant and the donor but not the recipient. The mean recombination event size was found to be significantly larger in cell-to-cell contact cultures (4051 bp in filter assemblage and 3938 bp in biofilm co-culture versus 1815 bp with saturating DNA). Up to 5.8% of the genome was transferred, through 20 recombination events, to a single recipient, with the largest single event incorporating 29,971 bp. We also found that some recombination events are clustered, that these clusters are more likely to occur in cell-to-cell contact environments, and that they cause significantly increased linkage of genes as far apart as 60,000 bp. We conclude that pneumococcal evolution through homologous recombination is more likely to occur on a larger scale in environments that permit cell-to-cell contact.

Mid-Holocene palaeoflood events recorded at the Zhongqiao Neolithic cultural site in the Jianghan Plain, middle Yangtze River Valley, China

NASA Astrophysics Data System (ADS)

Wu, Li; Zhu, Cheng; Ma, Chunmei; Li, Feng; Meng, Huaping; Liu, Hui; Li, Linying; Wang, Xiaocui; Sun, Wei; Song, Yougui

2017-10-01

Palaeo-hydrological and archaeological investigations were carried out in the Jianghan Plain in the middle reaches of the Yangtze River. Based on a comparative analysis of modern flood sediments and multidisciplinary approaches such as AMS14C and archaeological dating, zircon micromorphology, grain size, magnetic susceptibility, and geochemistry, we identified palaeoflood sediments preserved at the Zhongqiao archaeological site. The results indicate that three palaeoflood events (i.e. 4800-4597, 4479-4367, and 4168-3850 cal. yr BP) occurred at the Zhongqiao Site. Comparisons of palaeoflood deposit layers at a number of Neolithic cultural sites show that two extraordinary palaeoflood events occurred in the Jianghan Plain during approximately 4900-4600 cal. yr BP (i.e.mid-late Qujialing cultural period) and 4100-3800 cal. yr BP (i.e. from late Shijiahe cultural period to the Xia Dynasty). Further analysis of the environmental context suggests that these flooding events might have been connected with great climate variability during approximately 5000-4500 cal. yr BP and at ca. 4000 cal. yr BP. These two palaeoflood events were closely related to the expansion of the Jianghan lakes driven by the climatic change, which in turn influenced the rise and fall of the Neolithic cultures in the middle reaches of the Yangtze River. Other evidence also suggests that the intensified discrepancy between social development and environmental change processes (especially the hydrological process) during the late Shijiahe cultural period might be the key factor causing the collapse of the Shijiahe Culture. The extraordinary floods related to the climatic anomaly at ca. 4000 cal. yr BP and political conflicts from internal or other cultural areas all accelerated the collapse of the Shijiahe Culture.

Efficacy and adverse events of cold vs hot polypectomy: A meta-analysis.

PubMed

Fujiya, Mikihiro; Sato, Hiroki; Ueno, Nobuhiro; Sakatani, Aki; Tanaka, Kazuyuki; Dokoshi, Tatsuya; Fujibayashi, Shugo; Nomura, Yoshiki; Kashima, Shin; Gotoh, Takuma; Sasajima, Junpei; Moriichi, Kentaro; Watari, Jiro; Kohgo, Yutaka

2016-06-21

To compare previously reported randomized controlled studies (RCTs) of cold and hot polypectomy, we systematically reviewed and clarify the utility of cold polypectomy over hot with respect to efficacy and adverse events. A meta-analysis was conducted to evaluate the predominance of cold and hot polypectomy for removing colon polyps. Published articles and abstracts from worldwide conferences were searched using the keywords "cold polypectomy". RCTs that compared either or both the effects or adverse events of cold polypectomy with those of hot polypectomy were collected. The patients' demographics, endoscopic procedures, No. of examined lesions, lesion size, macroscopic and histologic findings, rates of incomplete resection, bleeding amount, perforation, and length of procedure were extracted from each study. A forest plot analysis was used to verify the relative strength of the effects and adverse events of each procedure. A funnel plot was generated to assess the possibility of publication bias. Ultimately, six RCTs were selected. No significant differences were noted in the average lesion size (less than 10 mm) between the cold and hot polypectomy groups in each study. Further, the rates of complete resection and adverse events, including delayed bleeding, did not differ markedly between cold and hot polypectomy. The average procedural time in the cold polypectomy group was significantly shorter than in the hot polypectomy group. Cold polypectomy is a time-saving procedure for removing small polyps with markedly similar curability and safety to hot polypectomy.

Human Adaptation Along the Columbia River 4700 - 1600 BP. A Report of Test Excavation at River Mile 590, North Central Washington.

DTIC Science & Technology

1984-01-01

represent a high energy investment in shelter . Pithouses, thus represent, in our view, semi-permanent base-camp use of a site. Mussel shell and FCR... Cordillera to beyond Yellowstone Park (Wadding ton and Wright 1974; Mehringer et al. 1977). A cold-adapted form of Artemisia (sagebrush) dominated... sheltered sites, away from the cold, drying winds and root-damaging effects of permafrost (Mack et al. 1976). Birches and (i) There are problems with

Benefit and harm of intensive blood pressure treatment: Derivation and validation of risk models using data from the SPRINT and ACCORD trials

PubMed Central

Denton, Brian T.; Hayward, Rodney A.

2017-01-01

Background Intensive blood pressure (BP) treatment can avert cardiovascular disease (CVD) events but can cause some serious adverse events. We sought to develop and validate risk models for predicting absolute risk difference (increased risk or decreased risk) for CVD events and serious adverse events from intensive BP therapy. A secondary aim was to test if the statistical method of elastic net regularization would improve the estimation of risk models for predicting absolute risk difference, as compared to a traditional backwards variable selection approach. Methods and findings Cox models were derived from SPRINT trial data and validated on ACCORD-BP trial data to estimate risk of CVD events and serious adverse events; the models included terms for intensive BP treatment and heterogeneous response to intensive treatment. The Cox models were then used to estimate the absolute reduction in probability of CVD events (benefit) and absolute increase in probability of serious adverse events (harm) for each individual from intensive treatment. We compared the method of elastic net regularization, which uses repeated internal cross-validation to select variables and estimate coefficients in the presence of collinearity, to a traditional backwards variable selection approach. Data from 9,069 SPRINT participants with complete data on covariates were utilized for model development, and data from 4,498 ACCORD-BP participants with complete data were utilized for model validation. Participants were exposed to intensive (goal systolic pressure < 120 mm Hg) versus standard (<140 mm Hg) treatment. Two composite primary outcome measures were evaluated: (i) CVD events/deaths (myocardial infarction, acute coronary syndrome, stroke, congestive heart failure, or CVD death), and (ii) serious adverse events (hypotension, syncope, electrolyte abnormalities, bradycardia, or acute kidney injury/failure). The model for CVD chosen through elastic net regularization included interaction terms suggesting that older age, black race, higher diastolic BP, and higher lipids were associated with greater CVD risk reduction benefits from intensive treatment, while current smoking was associated with fewer benefits. The model for serious adverse events chosen through elastic net regularization suggested that male sex, current smoking, statin use, elevated creatinine, and higher lipids were associated with greater risk of serious adverse events from intensive treatment. SPRINT participants in the highest predicted benefit subgroup had a number needed to treat (NNT) of 24 to prevent 1 CVD event/death over 5 years (absolute risk reduction [ARR] = 0.042, 95% CI: 0.018, 0.066; P = 0.001), those in the middle predicted benefit subgroup had a NNT of 76 (ARR = 0.013, 95% CI: −0.0001, 0.026; P = 0.053), and those in the lowest subgroup had no significant risk reduction (ARR = 0.006, 95% CI: −0.007, 0.018; P = 0.71). Those in the highest predicted harm subgroup had a number needed to harm (NNH) of 27 to induce 1 serious adverse event (absolute risk increase [ARI] = 0.038, 95% CI: 0.014, 0.061; P = 0.002), those in the middle predicted harm subgroup had a NNH of 41 (ARI = 0.025, 95% CI: 0.012, 0.038; P < 0.001), and those in the lowest subgroup had no significant risk increase (ARI = −0.007, 95% CI: −0.043, 0.030; P = 0.72). In ACCORD-BP, participants in the highest subgroup of predicted benefit had significant absolute CVD risk reduction, but the overall ACCORD-BP participant sample was skewed towards participants with less predicted benefit and more predicted risk than in SPRINT. The models chosen through traditional backwards selection had similar ability to identify absolute risk difference for CVD as the elastic net models, but poorer ability to correctly identify absolute risk difference for serious adverse events. A key limitation of the analysis is the limited sample size of the ACCORD-BP trial, which expanded confidence intervals for ARI among persons with type 2 diabetes. Additionally, it is not possible to mechanistically explain the physiological relationships explaining the heterogeneous treatment effects captured by the models, since the study was an observational secondary data analysis. Conclusions We found that predictive models could help identify subgroups of participants in both SPRINT and ACCORD-BP who had lower versus higher ARRs in CVD events/deaths with intensive BP treatment, and participants who had lower versus higher ARIs in serious adverse events. PMID:29040268

Blood pressure and stroke: an overview of published reviews.

PubMed

Lawes, Carlene M M; Bennett, Derrick A; Feigin, Valery L; Rodgers, Anthony

2004-03-01

The last few years have seen a considerable increase in the amount of information available concerning blood pressure (BP) and stroke associations. This article provides an overview of published reviews of the effects on stroke seen in trials of BP-lowering drugs and compares these with the results available from cohort studies. We present a review of major overviews of prospective cohort studies and an updated meta-analysis of >40 randomized controlled trials of BP lowering, which included >188 000 participants and approximately 6800 stroke events. Cohort studies now indicate that in the Asia Pacific region as well as in North America and Western Europe, each 10 mm Hg lower systolic BP is associated with a decrease in risk of approximately one third in subjects aged 60 to 79 years. The association is continuous down to levels of at least 115/75 mm Hg and is consistent across sexes, regions, and stroke subtypes and for fatal and nonfatal events. The proportional association is age dependent but is still a strong and positive association in those aged 80 years. Data from randomized controlled trials, in which mean age at event was approximately 70 years, indicate that a 10 mm Hg reduction in systolic BP is associated with a reduction in risk of stroke of approximately one third. Per mm Hg systolic BP reduction, the benefits for stroke appear similar between agents, by baseline BP levels, and whether or not individuals have a past history of cardiovascular disease. There is, however, evidence of greater benefit with a larger BP reduction. The epidemiologically expected benefits of BP lowering for stroke risk reduction are broadly consistent across a range of different population subgroups. There are greater benefits from larger BP reductions, and initiating and maintaining BP reduction for stroke prevention is a more important issue than choice of initial agent.

Blood pressure and stroke: an overview of published reviews.

PubMed

Lawes, Carlene M M; Bennett, Derrick A; Feigin, Valery L; Rodgers, Anthony

2004-04-01

The last few years have seen a considerable increase in the amount of information available concerning blood pressure (BP) and stroke associations. This article provides an overview of published reviews of the effects on stroke seen in trials of BP-lowering drugs and compares these with the results available from cohort studies. We present a review of major overviews of prospective cohort studies and an updated meta-analysis of >40 randomized controlled trials of BP lowering, which included >188 000 participants and approximately 6800 stroke events. Cohort studies now indicate that in the Asia Pacific region as well as in North America and Western Europe, each 10 mm Hg lower systolic BP is associated with a decrease in risk of stroke of approximately one third in subjects aged 60 to 79 years. The association is continuous down to levels of at least 115/75 mm Hg and is consistent across sexes, regions, and stroke subtypes and for fatal and nonfatal events. The proportional association is age dependent but is still strong and positive in those aged 80 years. Data from randomized controlled trials, in which mean age at event was approximately 70 years, indicate that a 10 mm Hg reduction in systolic BP is associated with a reduction in risk of stroke of approximately one third. Per mm Hg systolic BP reduction, the relative benefits for stroke appear similar between agents, by baseline BP levels, and whether or not individuals have a past history of cardiovascular disease. There is, however, evidence of greater benefit with a larger BP reduction. The epidemiologically expected benefits of BP lowering for stroke risk reduction are broadly consistent across a range of different population subgroups. There are greater benefits from larger BP reductions, and initiating and maintaining BP reduction for stroke prevention is a more important issue than choice of initial agent.

New Progress in Paleoearthquake Studies of the East Sertengshan Piedmont Fault, Inner Mongolia, China

NASA Astrophysics Data System (ADS)

He, Zhongtai

2017-04-01

The two eastern segments of the Sertengshan piedmont fault have moved considerably since the Holocene. Several paleoseismic events have occurred along the fault since 30 ka BP. Paleoearthquake studies have been advanced by digging new trenches and combining the results with the findings of previous studies. Comprehensive analyses of the trenches revealed that 6 paleoseismic events have occurred on the Kuoluebulong segment since approximately 30 ka BP within the following successive time periods: 19.01-37.56 ka, 18.73 ka, 15.03-15.86 ka, 10.96 ka, 5.77-6.48 ka and 2.32 ka BP. The analyses also revealed that 6 paleoseismic events have occurred on the Dashetai segment since approximately 30 ka BP, and the successive occurrence times are 29.07 ka, 19.12-28.23 ka, 13.92-15.22 ka, 9.38-9.83 ka, 6.08-8.36 ka and 3.59 ka BP. The results indicate that quasi-periodic recurrences occurred along the two segments with an approximate 4000 a mean recurrence interval. The consistent timing of the 6 events between the two segments indicates that the segments might conform to the cascade rupturing model between the two segments of the Sertengshan piedmont fault. The latest event on the Kuoluebulong segment of the Sertengshan piedmont fault is the historical M8 earthquake that occurred on November 11, 7 BC, which was recorded by a large number of Chinese historical texts.

Evidence for higher-than-average air temperatures after the 8.2 ka event provided by a Central European δ18O record

NASA Astrophysics Data System (ADS)

Andersen, Nils; Lauterbach, Stefan; Erlenkeuser, Helmut; Danielopol, Dan L.; Namiotko, Tadeusz; Hüls, Matthias; Belmecheri, Soumaya; Dulski, Peter; Nantke, Carla; Meyer, Hanno; Chapligin, Bernhard; von Grafenstein, Ulrich; Brauer, Achim

2017-09-01

The so-called 8.2 ka event represents one of the most prominent cold climate anomalies during the Holocene warm period. Accordingly, several studies have addressed its trigger mechanisms, absolute dating and regional characteristics so far. However, knowledge about subsequent climate recovery is still limited although this might be essential for the understanding of rapid climatic changes. Here we present a new sub-decadally resolved and precisely dated oxygen isotope (δ18O) record for the interval between 7.7 and 8.7 ka BP (103 calendar years before AD 1950), derived from the calcareous valves of benthic ostracods preserved in the varved lake sediments of pre-Alpine Mondsee (Austria). Besides a clear reflection of the 8.2 ka event, showing a good agreement in timing, duration and magnitude with other regional stable isotope records, the high-resolution Mondsee lake sediment record provides evidence for a 75-year-long interval of higher-than-average δ18O values directly after the 8.2 ka event, possibly reflecting increased air temperatures in Central Europe. This observation is consistent with evidence from other proxy records in the North Atlantic realm, thus most probably reflecting a hemispheric-scale climate signal rather than a local phenomenon. As a possible trigger we suggest an enhanced resumption of the Atlantic meridional overturning circulation (AMOC), supporting assumptions from climate model simulations.

Twenty-Four-Hour Central Pulse Pressure for Cardiovascular Events Prediction in a Low-Cardiovascular-Risk Population: Results From the Bordeaux Cohort.

PubMed

Cremer, Antoine; Boulestreau, Romain; Gaillard, Prune; Lainé, Marion; Papaioannou, Georgios; Gosse, Philippe

2018-02-23

Central blood pressure (BP) is a promising marker to identify subjects with higher cardiovascular risk than expected by traditional risk factors. Significant results have been obtained in populations with high cardiovascular risk, but little is known about low-cardiovascular-risk patients, although the differences between central and peripheral BP (amplification) are usually greater in this population. The study aim was to evaluate central BP over 24 hours for cardiovascular event prediction in hypertensive subjects with low cardiovascular risk. Peripheral and central BPs were recorded during clinical visits and over 24 hours in hypertensive patients with low cardiovascular risk (Systematic Coronary Risk Evaluation ≤5%). Our primary end point is the occurrence of a cardiovascular event during follow-up. To assess the potential interest in central pulse pressure over 24 hours, we performed Cox proportional hazard models analysis and comparison of area under the curves using the contrast test for peripheral and central BP. A cohort of 703 hypertensive subjects from Bordeaux were included. After the first 24 hours of BP measurement, the subjects were then followed up for an average of 112.5±70 months. We recorded 65 cardiovascular events during follow-up. Amplification was found to be significantly associated with cardiovascular events when added to peripheral 24-hour pulse pressure ( P =0.0259). The area under the curve of 24-hour central pulse pressure is significantly more important than area under the curve of office BP ( P =0.0296), and there is a trend of superiority with the area under the curve of peripheral 24-hour pulse pressure. Central pulse pressure over 24 hours improves the prediction of cardiovascular events for hypertensive patients with low cardiovascular risk compared to peripheral pulse pressure. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

A 6900-year history of landscape modification by humans in lowland Amazonia

NASA Astrophysics Data System (ADS)

Bush, M. B.; Correa-Metrio, A.; McMichael, C. H.; Sully, S.; Shadik, C. R.; Valencia, B. G.; Guilderson, T.; Steinitz-Kannan, M.; Overpeck, J. T.

2016-06-01

A sedimentary record from the Peruvian Amazon provided evidence of climate and vegetation change for the last 6900 years. Piston cores collected from the center of Lake Sauce, a 20 m deep lake at 600 m elevation, were 19.7 m in length. The fossil pollen record showed a continuously forested catchment within the period of the record, although substantial changes in forest composition were apparent. Fossil charcoal, found throughout the record, was probably associated with humans setting fires. Two fires, at c. 6700 cal BP and 4270 cal BP, appear to have been stand-replacing events possibly associated with megadroughts. The fire event at 4270 cal BP followed a drought that caused lowered lake levels for several centuries. The successional trajectories of forest recovery following these large fires were prolonged by smaller fire events. Fossil pollen of Zea mays (cultivated maize) provided evidence of agricultural activity at the site since c. 6320 cal BP. About 5150 years ago, the lake deepened and started to deposit laminated sediments. Maize agriculture reached a peak of intensity between c. 3380 and 700 cal BP. Fossil diatom data provided a proxy for lake nutrient status and productivity, both of which peaked during the period of maize cultivation. A marked change in land use was evident after c. 700 cal BP when maize agriculture was apparently abandoned at this site. Iriartea, a hyperdominant of riparian settings in western Amazonia, increased in abundance within the last 1100 years, but declined markedly at c. 1070 cal BP and again between c. 80 and -10 cal BP.

Exposure to Racial Discrimination and Ambulatory Blood Pressure in Women with Type 2 Diabetes.

PubMed

Wagner, Julie; Tennen, Howard; Finan, Patrick; Feinn, Richard; Burg, Matthew M; Seawell, Asani; White, William B

2016-10-01

Diabetes is the only disorder in which women's risk for heart disease exceeds men's. Elevated blood pressure (BP) increases cardiovascular risk in people with type 2 diabetes. Racial discrimination and neuroticism are both associated with BP levels but have not been examined in concert. This study investigated self-reported racial discrimination, neuroticism and ambulatory BP in women with type 2 diabetes. Thirty-nine Black and 38 White women completed a race-neutral version of the Schedule of Racist Events; BP was evaluated using ambulatory monitoring devices. Actigraphy and diaries were used to document times of sleep and wakefulness. Racial discrimination interacted with neuroticism to predict systolic and diastolic BP both while awake and during sleep, after adjustment for covariates. For each, the influence of racist events was stronger at lower levels of neuroticism. Racial discrimination is associated with higher levels of 24-h BP in diabetic women who are low in neuroticism. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Partial pharmacologic blockade shows sympathetic connection between blood pressure and cerebral blood flow velocity fluctuations.

PubMed

Hilz, Max J; Wang, Ruihao; Marthol, Harald; Liu, Mao; Tillmann, Alexandra; Riss, Stephan; Hauck, Paulina; Hösl, Katharina M; Wasmeier, Gerald; Stemper, Brigitte; Köhrmann, Martin

2016-06-15

Cerebral autoregulation (CA) dampens transfer of blood pressure (BP)-fluctuations onto cerebral blood flow velocity (CBFV). Thus, CBFV-oscillations precede BP-oscillations. The phase angle (PA) between sympathetically mediated low-frequency (LF: 0.03-0.15Hz) BP- and CBFV-oscillations is a measure of CA quality. To evaluate whether PA depends on sympathetic modulation, we assessed PA-changes upon sympathetic stimulation with and without pharmacologic sympathetic blockade. In 10 healthy, young men, we monitored mean BP and CBFV before and during 120-second cold pressor stimulation (CPS) of one foot (0°C ice-water). We calculated mean values, standard deviations and sympathetic LF-powers of all signals, and PAs between LF-BP- and LF-CBFV-oscillations. We repeated measurements after ingestion of the adrenoceptor-blocker carvedilol (25mg). We compared parameters before and during CPS, without and after carvedilol (analysis of variance, post-hoc t-tests, significance: p<0.05). Without carvedilol, CPS increased BP, CBFV, BP-LF- and CBFV-LF-powers, and shortened PA. Carvedilol decreased resting BP, CBFV, BP-LF- and CBFV-LF-powers, while PAs remained unchanged. During CPS, BPs, CBFVs, BP-LF- and CBFV-LF-powers were lower, while PAs were longer with than without carvedilol. With carvedilol, CPS no longer shortened resting PA. Sympathetic activation shortens PA. Partial adrenoceptor blockade abolishes this PA-shortening. Thus, PA-measurements provide a subtle marker of sympathetic influences on CA and might refine CA evaluation. Copyright © 2016 Elsevier B.V. All rights reserved.

Relationship of Office and Ambulatory Blood Pressure With Left Ventricular Global Longitudinal Strain.

PubMed

Sera, Fusako; Jin, Zhezhen; Russo, Cesare; Lee, Edward S; Schwartz, Joseph E; Rundek, Tatjana; Elkind, Mitchell S V; Homma, Shunichi; Sacco, Ralph L; Di Tullio, Marco R

2016-11-01

Left ventricular (LV) global longitudinal strain (GLS) is an early indicator of subclinical cardiac dysfunction, even when LV ejection fraction (LVEF) is normal, and is an independent predictor of cardiovascular events. Ambulatory blood pressure (BP) is a better predictor of cardiovascular events, including heart failure, than office BP. We investigated the association of office and ambulatory BP measurements with subclinical LV systolic dysfunction in a community-based cohort with normal LVEF. Two-dimensional speckle-tracking echocardiography and 24-hour ambulatory BP monitoring were performed in 577 participants (mean age 70±9 years; 60% women) with LVEF ≥50% from the Cardiovascular Abnormalities and Brain Lesions (CABL) study. Univariable and multivariable linear regression analyses were used to assess the associations of BP measures with GLS. Higher ambulatory and office BP values were consistently associated with impaired GLS. After adjustment for pertinent covariates (age, sex, race/ethnicity, body mass index, diabetes mellitus, coronary artery disease, LV mass index, and antihypertensive medication), office diastolic BP and ambulatory systolic and diastolic BPs (24-hour, daytime and nighttime) were independently associated with GLS (P = 0.003 for office DBP, P ≤ 0.001 for all ambulatory BPs). When ambulatory and office BP values were included in the same model, all ambulatory BP measures remained significantly associated with GLS (all P < 0.01), whereas office BP values were not. Ambulatory BP values are significantly associated with impaired GLS and the association is stronger than for office BP. Ambulatory BP monitoring might have a role in the risk stratification of hypertensive patients for early LV dysfunction.

The 9.2 ka event in Asian summer monsoon area: the strongest millennial scale collapse of the monsoon during the Holocene

NASA Astrophysics Data System (ADS)

Zhang, Wenchao; Yan, Hong; Dodson, John; Cheng, Peng; Liu, Chengcheng; Li, Jianyong; Lu, Fengyan; Zhou, Weijian; An, Zhisheng

2018-04-01

Numerous Holocene paleo-proxy records exhibit a series of centennial-millennial scale rapid climatic events. Unlike the widely acknowledged 8.2 ka climate anomaly, the likelihood of a significant climate excursion at around 9.2 cal ka BP, which has been notably recognized in some studies, remains to be fully clarified in terms of its magnitude and intensity, as well as its characteristics and spatial distributions in a range of paleoclimatic records. In this study, a peat sediment profile from the Dajiuhu Basin in central China was collected with several geochemical proxies and a pollen analysis carried out to help improve understanding of the climate changes around 9.2 cal ka BP. The results show that the peat development was interrupted abruptly at around 9.2 cal ka BP, when the chemical weathering strength decreased and the tree-pollen declined. This suggests that a strong drier regional climatic event occurred at around 9.2 cal ka BP in central China, which was, in turn, probably connected to the rapid 9.2 ka climate event co-developing worldwide. In addition, based on the synthesis of our peat records and the other Holocene hydrological records from Asian summer monsoon (ASM) region, we further found that the 9.2 ka event probably constituted the strongest abrupt collapse of the Asian monsoon system during the full Holocene interval. The correlations between ASM and the atmospheric 14C production rate, the North Atlantic drift ice records and Greenland temperature indicated that the weakened ASM event at around 9.2 cal ka BP could be interpreted by the co-influence of external and internal factors, related to the changes of the solar activity and the Atlantic Meridional Overturning Circulation (AMOC).

The Renalase Asp37Glu polymorphism is not associated with hypertension and cardiovascular events in an urban-based prospective cohort: the Malmö Diet and cancer study.

PubMed

Fava, Cristiano; Montagnana, Martina; Danese, Elisa; Sjögren, Marketa; Almgren, Peter; Engström, Gunnar; Hedblad, Bo; Guidi, Gian Cesare; Minuz, Pietro; Melander, Olle

2012-07-19

Renalase (gene name RNLS), a recently discovered enzyme with monoamine oxidase activity, is implicated in the degradation of catecholamines. Recent studies delineate a possible role of this enzyme in blood pressure (BP) maintenance and cardiac protection and two single nucleotide polymorphisms, RNLS rs2576178 A > G and rs2296545 C > G have been associated with hypertension. The latter SNP leads to a non synonymous Asp to Glu substitution deleting a flavin adenine dinucleotide (FAD) binding site with possible impaired functionality. We tested the hypothesis that these polymorphisms could affect BP levels, hypertension prevalence, and risk of incident cardiovascular events in middle-aged Swedes. The polymorphisms were genotyped in 5696 participants of the population-based Cardiovascular Cohort of the "Malmö Diet and Cancer" (MDC-CC). The incidence of cardiovascular events (coronary events [n = 408], strokes [n = 330], heart failure [n = 190] and atrial fibrillation/flutter [n = 406]) was monitored for an average of approximately 15 years of follow-up. Both before and after adjustment for sex, age and BMI the polymorphisms did not show any effect on BP level and hypertension prevalence. Before and after adjustment for major cardiovascular risk factors, the hazard ratio for cardiac and cerebrovascular events was not significantly different in carriers of different genotypes. A significant interaction was found between the rs2296545 C > G and age with respect to BP/hypertension. Our data do not support a major role for these RNLS polymorphisms in determining BP level and incident events at population level. The positive interaction with age suggest that the effect of the rs2296545 C > G polymorphism, if any, could vary between different ages.

Hypertension: New perspective on its definition and clinical management by bedtime therapy substantially reduces cardiovascular disease risk.

PubMed

Hermida, Ramón C; Ayala, Diana E; Fernández, José R; Mojón, Artemio; Smolensky, Michael H

2018-05-01

Diagnosis of hypertension-elevated blood pressure (BP) associated with increased cardiovascular disease (CVD) risk-and its management for decades have been based primarily on single time-of-day office BP measurements (OBPM) assumed representative of systolic (SBP) and diastolic BP (DBP) during the entire 24-hours span. Around-the-clock ambulatory blood pressure monitoring (ABPM), however, reveals BP undergoes 24-hours patterning characterized in normotensives and uncomplicated hypertensives by striking morning-time rise, 2 daytime peaks-one ~2-3 hours after awakening and the other early evening, small midafternoon nadir and 10-20% decline (BP dipping) in the asleep BP mean relative to the wake-time BP mean. A growing number of outcome trials substantiate correlation between BP and target organ damage, vascular and other risks is greater for the ABPM-derived asleep BP mean, independent and stronger predictor of CVD risk, than daytime OBPM or ABPM-derived awake BP. Additionally, bedtime hypertension chronotherapy, that is, ingestion of ≥1 conventional hypertension medications at bedtime to achieve efficient attenuation of asleep BP, better reduces total CVD events by 61% and major events (CVD death, myocardial infarction, ischaemic and haemorrhagic stroke) by 67%-even in more vulnerable chronic kidney disease, diabetes and resistant hypertension patients-than customary on-awaking therapy that targets wake-time BP. Such findings of around-the-clock ABPM and bedtime hypertension outcome trials, consistently indicating greater importance of asleep BP than daytime OBPM or ambulatory awake BP, call for a new definition of true arterial hypertension plus modern approaches for its diagnosis and management. © 2018 Stichting European Society for Clinical Investigation Journal Foundation.

Hydrological studies of the historical and palaeoflood events on the middle Yihe River, China

NASA Astrophysics Data System (ADS)

Hu, Guiming; Huang, Chun Chang; Zhou, Yali; Pang, Jiangli; Zha, Xiaochun; Guo, Yongqiang; Zhang, Yuzhu; Zhao, Xueru

2016-12-01

Palaeo-hydrological and sedimentary investigations were carried out in the Longmenxia Gorge of the middle Yihe River. Five bedsets of flood slackwater deposits (SWD) were found interbedded into Holocene aeolian loess-soil profiles in the river bank at the Longmenxia site. They were identified as the deposits of the suspended sediment load during the extreme flood events of the Holocene. The minimum flood peak discharges were estimated to be 12, 300-15, 300 m3/s using the slope-area method. These are about twice the largest gauged record (7180 m3/s) that has occurred since 1937. These flood events occurred at 3100-3000 a B.P., 1800-1700 a B.P., 700-550 a B.P. and 350-250 a B.P., as dated by optically stimulated luminescence (OSL) in combination with stratigraphic correlation, to which may be added the recorded events of the 223 and 1761 CE floods. These were associated with Holocene monsoonal shifts and abrupt climatic events. This research not only provides palaeoflood discharge estimates on the middle Yihe River, but also provides important data for understanding interactions between regional hydro-climatic systems and global climate change in humid and semi-humid monsoonal regions, such as China.

[Prevalence of target organ damage and factors associated with cardiovascular events in subjects with refractory hypertension].

PubMed

Armario, Pedro; Oliveras, Anna; Hernández Del Rey, Raquel; Poch, Esteban; Larrouse, María; Roca-Cusachs, Alex; de la Sierra, Alejandro

2009-06-27

To asses the prevalence of target organ damage (TOD) and factors associated with cardiovascular events in subjects with refractory hypertension. Cross-sectional study of 146 patients with clinical diagnosis of refractory hypertension. TOD was defined as the presence of microalbuminuria (MA), renal failure (RF), left ventricular hypertrophy (LVH) or left atrial enlargement (LAE). Cardiovascular events were defined as the antecedent of stroke, coronary heart disease, heart failure or peripheral arterial disease. 24-h ambulatory blood pressure monitoring was (ABPM) performed with a validated Spacelabs 90207. The prevalence of LVH was 62.3%, and LAE was observed in 27.7% of the subjects. The prevalence of RF was 28.1% and MA was found in 41,4%. An association between MA and LVH was observed. After adjusting by age, the urinary albumin excretion (UAE) correlated with clinical blood pressure (BP) and BP during 24-h ABPM, whereas LVMI correlated with ambulatory BP but not with clinical BP. The prevalence of previous cardiovascular events was 22% and in the multivariate regression analysis, UAE was the only independent factor associated with the antecedent of cardiovascular events. In subjects with refractory hypertension, the prevalence of TOD was high, and an association between heart and renal organ damage was observed. UAE was independently associated with the antecedent of cardiovascular disease.

Multi-Decadal to Millennial Scale Holocene Hydrologic Variation in the Southern Hemisphere Tropics of South America

NASA Astrophysics Data System (ADS)

Ekdahl, E. J.; Fritz, S. C.; Baker, P. A.; Burns, S. J.; Coley, K.; Rigsby, C. A.

2005-12-01

Numerous sites in the Northern Hemisphere show multi-decadal to millennial scale climate variation during the Holocene, many of which have been correlated with changes in atmospheric radiocarbon production or with changes in North Atlantic oceanic circulation. The manifestation of such climate variability in the hydrology of the Southern Hemisphere tropics of South America is unclear, because of the limited number of records at suitably high resolution. In the Lake Titicaca drainage basin of Bolivia and Peru, high-resolution lacustrine records reveal the overall pattern of Holocene lake-level change, the influence of precessional forcing of the South American Summer Monsoon, and the effects of high-frequency climate variability in records of lake productivity and lake ecology. Precessional forcing of regional precipitation is evident in the Lake Titicaca basin as a massive (ca. 85 m) mid-Holocene decline in lake level beginning about 7800 cal yr BP and a subsequent rise in lake level after 4000 cal yr BP. Here we show that multi-decadal to millennial-scale climate variability, superimposed upon the envelope of change at orbital time scales, is similar in timing and pattern to the ice-rafted debris record of Holocene Bond events in the North Atlantic. A high-resolution carbon isotopic record from Lake Titicaca that spans the entire Holocene suggests that cold intervals of Holocene Bond events are periods of increased precipitation, thus indicating an anti-phasing of precipitation variation on the Altiplano relative to the Northern Hemisphere tropics. A similar pattern of variation is also evident in high-resolution (2-30 yr spacing) diatom and geochemical records that span the last 7000 yr from two smaller lakes, Lagos Umayo and Lagunillas, in the Lake Titicaca drainage basin.

Changes in northeast Atlantic hydrology during Termination 1: Insights from Celtic margin's benthic foraminifera

NASA Astrophysics Data System (ADS)

Mojtahid, M.; Toucanne, S.; Fentimen, R.; Barras, C.; Le Houedec, S.; Soulet, G.; Bourillet, J.-F.; Michel, E.

2017-11-01

Using benthic foraminiferal-based proxies in sediments from the Celtic margin, we provide a well-dated record across the last deglaciation of the Channel River dynamics and its potential impact on the hydrology of intermediate water masses along the European margin. Our results describe three main periods: 1) During the Last Glacial Maximum, and before ∼21 ka BP, the predominance of meso-oligotrophic species suggests well oxygenated water masses. After ∼21 ka BP, increasing proportions of eutrophic species related to enhanced riverine supply occurs concomitantly with early warming in Greenland air-temperatures; 2) A thick laminated deposit, occurring during a 1500-years long period of seasonal melting of the European Ice Sheet (EIS), is associated with early Heinrich Stadial 1 period (∼18.2-16.7 ka BP). The benthic proxies describe low salinity episodes, cold temperatures, severe dysoxia and eutrophic conditions on the sea floor, perhaps evidence for cascading of turbid meltwaters; 3) During late HS1 (∼16.7-14.7 ka BP), conditions on the Celtic margin's seafloor changed drastically and faunas indicate oligotrophic conditions as a result of the ceasing of EIS meltwater discharges. While surface waters were cold due to Laurentide Ice Sheet (LIS) icebergs releases, increasing benthic Mg/Ca ratios reveal a progressive warming of intermediate water masses whereas oxygen proxies indicate overall well oxygenated conditions. In addition to the well known effect of EIS meltwaters on surface waters in the Celtic margin, our benthic record documents a pronounced impact on intermediate water depths during HS1, which coincided with major AMOC disruptions.

Efficacy and tolerability of combination therapy with valsartan/hydrochlorothiazide in the initial treatment of severe hypertension.

PubMed

Calhoun, David A; Glazer, Robert D; Pettyjohn, Frank S; Coenen, P D M; Zhao, Yanxing; Grosso, Amie

2008-08-01

Most patients with severe hypertension are at high risk for cardiovascular events and require prompt blood pressure (BP)-lowering and combination therapy to achieve BP goals. This study evaluated the therapeutic efficacy and tolerability of initial treatment with the combination of valsartan and hydrochlorothiazide (HCTZ) compared with valsartan monotherapy in patients with severe hypertension. This was a 6-week, randomized, double-blind, multicenter, forced titration study that compared initial therapy with the combination of valsartan/HCTZ 160/12.5 mg (force titrated to 160/25 mg after 2 weeks and to 320/25 mg after 4 weeks) to monotherapy with valsartan 160 mg (force titrated to 320 mg after 2 weeks and sham-titrated to 320 mg after 4 weeks). Eligible patients were 18-80 years old with severe essential hypertension (mean sitting diastolic BP > or = 110 mmHg and < 120 mmHg and mean sitting systolic BP > or = 140 mmHg and < 200 mmHg). The Clinical Trial Registry number was NCT00273299. The primary efficacy variable was the rate of BP control (mean sitting BP < 140/90 mmHg) at Week 4. Tolerability was evaluated by monitoring all adverse events, vital signs, and laboratory tests including hematology and biochemistry. A total of 608 patients were randomized to either valsartan/HCTZ (n = 307) or valsartan monotherapy (n = 301). Significantly more patients achieved overall BP control (< 140/90 mmHg) with valsartan/HCTZ compared to monotherapy at Week 4 (primary efficacy variable and timepoint) (39.6% vs. 21.8%; p < 0.0001) and Week 6 (48.2% vs. 27.2%; p < 0.0001). Mean reductions in BP at Week 4 were significantly greater for valsartan/HCTZ (30.8/22.7 mmHg vs. 21.7/17.5 mmHg; p < 0.0001), with further reductions at Week 6. BP control rates were greater with combination therapy as early as Week 2. The overall incidence of adverse events was comparable between the combination therapy (34.9%) and monotherapy (36.7%) treatment groups. A potential limitation of the forced-titration design is that some patients were titrated to higher doses despite having achieved goal BP. This may impact the interpretation of the incidence of dose-dependent adverse events. Initial therapy with valsartan/HCTZ is effective and well tolerated in patients with severe hypertension.

New insights on the origin of the High Velocity Peaks in the Galactic Bulge

NASA Astrophysics Data System (ADS)

Fernández-Trincado, J. G.; Robin, A. C.; Moreno, E.; Pérez-Villegas, A.; Pichardo, B.

2017-12-01

We provide new insight on the origin of the cold high-V_{los} peaks (˜200 kms^{-1}) in the Milky Way bulge discovered in the APOGEE commissioning data (Nidever et al. 2012). Here we show that such kinematic behaviour present in the field regions towards the Galactic bulge is not likely associated with orbits that build the boxy/peanut (B/P) bulge. To this purpose, a new set of test particle simulations of a kinematically cold stellar disk evolved in a 3D steady-state barred Milky Way galactic potential, has been analysed in detail. Especially bar particles trapped into the bar are identified through the orbital Jacobi energy E_{J}, which allows us to identify the building blocks of the B/P feature and investigate their kinematic properties. Finally, we present preliminary results showing that the high-V_{los} features observed towards the Milky Way bulge are a natural consequence of a large-scale midplane particle structure, which is unlikely associated with the Galactic bar.

Animal exploitation in northeast Tibetan Plateau during Neolithic-Bronze Age

NASA Astrophysics Data System (ADS)

Dong, Guanghui; Ren, Lele; Li, Zhipeng; Zhang, Dongju; Chen, Fahu

2017-04-01

The history and driving force for prehistoric human occupation of the Tibetan Plateau has been intensively concerned in recent years. Multidisciplinary studies reveal that human extensively and year-roundly settled below 2500 m asl in northeast Tibetan Plateau (NETP) since 5200BP mainly with the utilization of millet crops, and above 3000 m asl post 3600BP primarily with cold-tolerant barley. However, the strategy for human animal utilization during Neolithic and Bronze periods in NETP still remains enigmatic. We collected and identified hundreds of animal bones from 14 Neolithic and Bronze sites in NETP, with the application of radiocarbon dating, carbon and nitrogen isotopes analysis, and ancient DNA analysis, we explore the changing patterns of animal utilization, and potential human behaviours for taming wild animals in this area throughout late prehistoric times. These works shed lights for understanding when and how husbandry and pastoral economies emerged, and how prehistoric human adapted to the high-cold environment of the Tibetan Plateau..

The early Holocene humid period in the Tayma palaeolake, NW Arabian Peninsula -- A high-resolution micro-facies and geochemical approach

NASA Astrophysics Data System (ADS)

Neugebauer, Ina; Plessen, Birgit; Dinies, Michèle; Engel, Max; Tjallingii, Rik; Brauer, Achim

2016-04-01

The Tayma palaeolake is a rare archive of the early Holocene humid period in northern Arabia (Dinies et al. 2015; Engel et al. 2012). Here we present a ca. 1 m thick and 500 years spanning annually laminated sediment section that was deposited in the centre of the former lake from ca. 8500 to 8000 calibrated years (cal. yrs) BP, as determined by AMS 14C dating of pollen concentrates (Dinies et al. 2015). High-resolution micro-facies analyses based on thin section microscopy, μXRF element scanning, δ18Ocarb and δ13Ccarb measurements on single carbonate laminae, as well as geochemical measurements on bulk samples for TOC, CaCO3, C/N ratio, δ18Ocarb, δ13Ccarb, δ13Corg and δ15N determination were performed in order to investigate the sedimentological and geochemical changes along the varved sequence in great detail. The finely laminated marl sediments are mainly composed of sub-mm thick laminae of endogenic aragonite, organic matter and diatoms, as well as occasional, often graded silt-clay layers. Following an early lake phase from ca. 8700 to 8500 cal. yrs BP characterized by coarsely laminated, presumably non-annual marl sediments that are rich in ostracods, three main varved phases can be distinguished within the investigated section: (1) aragonitic-organic varves from ca. 8500 to 8300 cal. yrs BP, (2) diatom-organic varves from ca. 8300 to 8100 cal. yrs BP that frequently include aragonite laminae and occasionally gastropod and ostracod shells, and (3) organic varves from ca. 8100 to 8000 cal. yrs BP with decreasing diatom and aragonite laminae and an increasing frequency of gypsum layers. After this period, gypsum becomes abundant and fine lamination appears only sporadically. In addition, we observe increasing trends of TOC, C/N and δ13Ccarb and decreasing δ18Ocarb during phase 1 and excess δ18Ocarb, δ13Ccarb and TOC values during phase 2, pointing towards the maximum lake productivity and increased seasonal precipitation. We interpret this sedimentological-geochemical succession as reflecting a high moisture availability during the early Holocene that culminates at around 8200 cal. yrs BP (phase 2). Stimulated by the coincidence in timing, we will discuss possible relations to the so-called 8.2 ka cold event in the North Atlantic realm. This study is a contribution to the research project "CLEAR - Holocene CLimatic Events of Northern ARabia" (https://clear2018.wordpress.com/). References: Dinies, M., Plessen, B., Neef, R., and Kürschner, H.: When the desert was green: Grassland expansion during the early Holocene in northwestern Arabia, Quaternary International, 382, 293-302, 2015. Engel, M., Brückner, H., Pint, A., Wellbrock, K., Ginau, A., Voss, P., Grottker, M., Klasen, N., and Frenzel, P.: The early Holocene humid period in NW Saudi Arabia - Sediments, microfossils and palaeo-hydrological modelling, Quaternary International, 266, 131-141, 2012.

Bisphosphonate-related osteonecrosis of the jaw: an Italian post-marketing surveillance analysis.

PubMed

Parretta, Elisabetta; Sottosanti, Laura; Sportiello, Liberata; Rafaniello, Concetta; Potenza, Simona; D'Amato, Salvatore; González-González, Rocio; Rossi, Francesco; Colella, Giuseppe; Capuano, Annalisa

2014-09-01

Although bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) is well recognized, little is known about it in terms of pathophysiology, epidemiology or management. We analyzed all suspected BRONJ reports sent to the Italian Pharmacovigilance Adverse Event Spontaneous Reporting System (Rete Nazionale Farmacovigilanza [RNF]) to determine their pattern and add new information about this relevant issue. All suspected BRONJ sent to the RNF between 2003 and 2011 were retrieved. After a case-by-case assessment procedure, we analyzed BP type, BP exposure time and time since last use. Between 2003 and 2011, 555 reports of osteonecrosis of the jaw (ONJ) after BP administration were recorded in the RNF. These events occurred mostly in patients affected by cancer (77.84%) in which zoledronate was the most frequently suspected BP. Most patients experienced ONJ after long-term use of the drug (median time of BP exposure being between 1.3 and 8.8 years). Interestingly, 139 (25.05%) cases of ONJ occurred between 2 and 121 months after BP withdrawal. This study shows that BRONJ can occur much earlier than hitherto reported, adds new data on BRONJ onset following ibandronate treatment and reveals that patients who cease BP-based therapy develop ONJ, raising the question of post-treatment monitoring strategies.

Circum-Mediterranean fire activity and climate changes during the mid Holocene environmental transition (8500-2500 cal yr BP)

NASA Astrophysics Data System (ADS)

Vannière, Boris; Power, Mitch J.; Roberts, Neil; Tinner, Willy; Carrión, José; Magny, Michel; Bartlein, Patrick

2010-05-01

In this contribution I will present a synthesis of mid- to late-Holocene fire activity from the Mediterranean basin and explore the linkages among fire, climate variability and seasonality, and people through several climatic and ecological transitions. Regional fire histories were created from 36 radiocarbon-dated sedimentary charcoal records, available from the Global Charcoal Database. During the mid-Holocene "Thermal Maximum", charcoal records from the northern Mediterranean suggest the region was more fire prone while records from the southern Mediterranean indicate a decrease in fire activity associated with wetter-than-present summers. A North-South partition at 40-43°N is apparent in the central and western Mediterranean. In the context of orbitally-induced summer insolation decrease, South Mediterranean wet conditions could be linked to the Afro-Asian summer monsoon which weakened after ca. 8000-6000 cal yr BP. Relatively abrupt changes in fire regime observed at ca. 5500-5000 cal yr BP may be associated to a threshold in this weakening influence of the orbitally-driven Afro-Asian monsoon strength. Charcoal records of past fire activity appear sensitive to both orbitally-forced climate changes and shorter lived excursions which may be related to cold events apparent in the North Atlantic record of ice-rafted debris. These results contradict former notions of gradual aridification of the entire region due to climatic forcing and/or human activities. In contrast, they suggest: 1) Teleconnections between the Mediterranean area and other climatic regions, in particular the North Atlantic and the low-latitude monsoon areas, influenced past fire regimes; 2) Gradual forcing, such as changes in orbital parameters, may have triggered more abrupt shifts in fire regime, either directly or indirectly through these teleconnections.

Altered Circadian Timing System-Mediated Non-Dipping Pattern of Blood Pressure and Associated Cardiovascular Disorders in Metabolic and Kidney Diseases

PubMed Central

Nishiyama, Akira

2018-01-01

The morning surge in blood pressure (BP) coincides with increased cardiovascular (CV) events. This strongly suggests that an altered circadian rhythm of BP plays a crucial role in the development of CV disease (CVD). A disrupted circadian rhythm of BP, such as the non-dipping type of hypertension (i.e., absence of nocturnal BP decline), is frequently observed in metabolic disorders and chronic kidney disease (CKD). The circadian timing system, controlled by the central clock in the suprachiasmatic nucleus of the hypothalamus and/or by peripheral clocks in the heart, vasculature, and kidneys, modulates the 24 h oscillation of BP. However, little information is available regarding the molecular and cellular mechanisms of an altered circadian timing system-mediated disrupted dipping pattern of BP in metabolic disorders and CKD that can lead to the development of CV events. A more thorough understanding of this pathogenesis could provide novel therapeutic strategies for the management of CVD. This short review will address our and others’ recent findings on the molecular mechanisms that may affect the dipping pattern of BP in metabolic dysfunction and kidney disease and its association with CV disorders. PMID:29385702

Ambulatory Blood Pressure Monitoring (ABPM) as the reference standard for diagnosis of hypertension and assessment of vascular risk in adults.

PubMed

Hermida, Ramón C; Smolensky, Michael H; Ayala, Diana E; Portaluppi, Francesco

2015-01-01

New information has become available since the ISC, AAMCC, and SECAC released their first extensive guidedelines to improve the diagnosis and treatment of adult arterial hypertension. A critical assessment of evidence and a comparison of what international guidelines now propose are the basis for the following statements, which update the recommendations first issued in 2013. Office blood pressure (BP) measurements should no longer be considered to be the "gold standard" for the diagnosis of hypertension and assessment of cardiovascular risk. Relying on office BP, even when supplemented with at-home wake-time self-measurements, to identify high-risk individuals, disregarding circadian BP patterning and asleep BP level, leads to potential misclassification of 50% of all evaluated persons. Accordingly, ambulatory BP monitoring is the recommended reference standard for the diagnosis of true hypertension and accurate assessment of cardiovascular risk in all adults ≥18 yrs of age, regardless of whether office BP is normal or elevated. Asleep systolic BP mean is the most significant independent predictor of cardiovascular events. The sleep-time relative SBP decline adds prognostic value to the statistical model that already includes the asleep systolic BP mean and corrected for relevant confounding variables. Accordingly, the asleep systolic BP mean is the recommended protocol to diagnose hypertension, assess cardiovascular risk, and predict cardiovascular event-free interval. In men, and in the absence of compelling clinical conditions, reference thresholds for diagnosing hypertension are 120/70 mmHg for the asleep systolic/diastolic BP means derived from ambulatory BP monitoring. However, in women, in the absence of complicating co-morbidities, the same thresholds are lower by 10/5 mmHg, i.e., 110/65 mmHg for the asleep means. In high-risk patients, including those diagnosed with diabetes or chronic kidney disease, and/or those having experienced past cardiovascular events, the thresholds are even lower by 15/10 mmHg, i.e., 105/60 mmHg. Bedtime treatment with the full daily dose of ≥1 hypertension medications is recommended as a cost-effective means to improve the management of hypertension and reduce hypertension-associated risk. Bedtime treatment entailing the full daily dose of ≥1 conventional hypertension medications must be the therapeutic regimen of choice for the elderly and those with diabetes, resistant and secondary hypertension, chronic kidney disease, obstructive sleep apnea, and medical history of past cardiovascular events, among others, given their documented high prevalence of sleep-time hypertension.

Mortality and cardiovascular events are best predicted by low central/peripheral pulse pressure amplification but not by high blood pressure levels in elderly nursing home subjects: the PARTAGE (Predictive Values of Blood Pressure and Arterial Stiffness in Institutionalized Very Aged Population) study.

PubMed

Benetos, Athanase; Gautier, Sylvie; Labat, Carlos; Salvi, Paolo; Valbusa, Filippo; Marino, Francesca; Toulza, Olivier; Agnoletti, Davide; Zamboni, Mauro; Dubail, Delphine; Manckoundia, Patrick; Rolland, Yves; Hanon, Olivier; Perret-Guillaume, Christine; Lacolley, Patrick; Safar, Michel E; Guillemin, Francis

2012-10-16

The aim of the longitudinal PARTAGE study was to determine the predictive value of blood pressure (BP) and pulse pressure amplification, a marker of arterial function, for overall mortality (primary endpoint) and major cardiovascular (CV) events, in subjects older than 80 years of age living in a nursing home. Assessment of pulse indexes may be important in the evaluation of the CV risk in very elderly frail subjects. A total of 1,126 subjects (874 women) who were living in French and Italian nursing homes were enrolled (mean age, 88 ± 5 years). Central (carotid) to peripheral (brachial) pulse pressure amplification (PPA) was calculated with the help of an arterial tonometer. Clinical and 3-day self-measurements of BP were conducted. During the 2-year follow-up, 247 subjects died, and 228 experienced major CV events. The PPA was a predictor of total mortality and major CV events in this population. A 10% increase in PPA was associated with a 24% (p < 0.0003) decrease in total mortality and a 17% (p < 0.01) decrease in major CV events. Systolic BP, diastolic BP, or pulse pressure were either not associated or inversely correlated with total mortality and major CV events. In very elderly individuals living in nursing homes, low PPA from central to peripheral arteries strongly predicts mortality and adverse effects. Assessment of this parameter could help in risk estimation and improve diagnostic and therapeutic strategies in very old, polymedicated persons. In contrast, high BP is not associated with higher risk of mortality or major CV events in this population. (Predictive Values of Blood Pressure and Arterial Stiffness in Institutionalized Very Aged Population [PARTAGE]; NCT00901355). Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Mortality risks during extreme temperature events (ETEs) using a distributed lag non-linear model

NASA Astrophysics Data System (ADS)

Allen, Michael J.; Sheridan, Scott C.

2018-01-01

This study investigates the relationship between all-cause mortality and extreme temperature events (ETEs) from 1975 to 2004. For 50 U.S. locations, these heat and cold events were defined based on location-specific thresholds of daily mean apparent temperature. Heat days were defined by a 3-day mean apparent temperature greater than the 95th percentile while extreme heat days were greater than the 97.5th percentile. Similarly, calculations for cold and extreme cold days relied upon the 5th and 2.5th percentiles. A distributed lag non-linear model assessed the relationship between mortality and ETEs for a cumulative 14-day period following exposure. Subsets for season and duration effect denote the differences between early- and late-season as well as short and long ETEs. While longer-lasting heat days resulted in elevated mortality, early season events also impacted mortality outcomes. Over the course of the summer season, heat-related risk decreased, though prolonged heat days still had a greater influence on mortality. Unlike heat, cold-related risk was greatest in more southerly locations. Risk was highest for early season cold events and decreased over the course of the winter season. Statistically, short episodes of cold showed the highest relative risk, suggesting unsettled weather conditions may have some relationship to cold-related mortality. For both heat and cold, results indicate higher risk to the more extreme thresholds. Risk values provide further insight into the role of adaptation, geographical variability, and acclimatization with respect to ETEs.

Precipitation Anomalies in Southern Brazil Associated with El Niño and La Niña Events.

NASA Astrophysics Data System (ADS)

Grimm, Alice M.; Ferraz, Simone E. T.; Gomes, Júlio

1998-11-01

The impact of El Niño and La Niña events (warm and cold phases of the Southern Oscillation) on rainfall over southern Brazil is investigated through the use of a large dataset of monthly precipitation from 250 stations. This region is partly dominated by rough orography and presents different climatic regimes of rainfall. As previous global studies on Southern Oscillation-precipitation relationships used data from only two stations in southern Brazil, this region was not included in the area of consistent Southern Oscillation-related precipitation in southeastern South America. The present analysis is based on the method by Ropelewski and Halpert, the sensitivity of which is assessed for this region. The spatial structure of the rainfall anomalies associated with warm (cold) events is analyzed and subregions with coherent anomalies are determined. Their distribution indicates the influence of relief, latitude, and proximity to the ocean. These areas are subjected to further analysis to determine the seasons of largest anomalies and assess their consistency during warm (cold) events.The whole of southern Brazil was found to have strong and consistent precipitation anomalies associated with those events. Their magnitude is even larger than in Argentina and Uruguay. All of the subregions have consistent wet anomalies during the austral spring of the warm event year, with a pronounced peak in November. The southeastern part also shows a consistent tendency to higher than average rainfall during the austral winter of the following year. There is also a consistent tendency to dryness in the year before a warm event. During the spring of cold event years strong consistent dry anomalies prevail over the whole region, also with maximum magnitude in November. They are even stronger and more consistent than the wet anomalies in warm event years. Consistent anomalies do not occur over large areas in the years before and after cold events. The wet anomalies during the austral spring of the warm event year weaken and even reverse during the following January. The same tendency, though not so clear, is observable in the dry anomalies of cold events. The seasons of largest anomalies disclosed by this study differ from those found by previous global studies for other regions in southeastern South America.This study expands the area of consistent warm (cold) event-related precipitation defined by previous studies in southeastern South America by including a region of larger anomalies, and provides a spatial and temporal refinement to the warm (cold) event-precipitation relationship.

Influence of Monsoon variations on ecosystem changes on the Central Tibetan Plateau during the last 24 ka cal BP (Invited)

NASA Astrophysics Data System (ADS)

Kasper, T.; Haberzettl, T.; Zhu, L.; Maeusbacher, R.

2013-12-01

Lakes as archives of climate and environmental change are well known and well investigated all over the world, also in high mountain areas such as the Tibetan Plateau (TP) which is one of the most important key players in global climate circulation. Lake sediment records in this area, which were subject to lots of paleoenvironmental investigations, are mostly focused on the Holocene, often showing discontinuities due to desiccation or are located at the margin of the TP, such as Lake Qinghai. Here we present the first continuous lake sediment record from the southern central TP from Lake Nam Co, comprising ~24 ka cal BP, i.e., the LGM, the post-Glacial and the entire Holocene. The record reveals environmental changes with varying intensities. Extraordinary high sediment accumulation rates (SAR = 1.3 mm a-1) and quite large quantities of minerogenic input associated with the absence of ostracods during the LGM point to a small lake within a cold and dry environment. Around 19 ka cal BP reduced SAR (~0.3 mm a-1) and the occurrence of ostracods refer to a rising lake level in a moister environment. During the post-Glacial (~16 ka cal BP) changes in the geochemical composition of the sediments and a shift in the pollen composition suggests a change in summer precipitation and wind direction associated with a stronger Indian Ocean Summer Monsoon (IOSM). Major variations in the geochemical parameters between ~12.6 and ~11.6 ka cal BP may reflect the Younger Dryas climate oscillation of the Northern Hemisphere with cool and arid environmental conditions. The most striking hydrological variation within this record occurs at ~9.5 ka cal BP in the early Holocene. A rise in TOC points to enhanced bio-productivity within the lake and the catchment as well as to hampered decomposition of organic matter at the lake floor. Pollen composition refers to alpine meadow vegetation assemblages during this time. This may reflect moist and warm conditions probably associated with a higher lake level and a strong stratification of the water body. Nevertheless, during the mid- and late-Holocene some changes of minor amplitude also occur. Around 4 ka cal BP a short-term increase in Mg points to a dry-event as seen in other monsoon dominated records. The probably most intensive shift to drier conditions with a rapidly falling lake level has been proposed to have occurred around 2 ka cal BP. Even the recent climate warming associated with higher rates of glacier melting, enhanced surface runoff and a rising lake level is reflected by this multi-proxy investigation.

Post-procedural hypertension following transcatheter aortic valve implantation: incidence and clinical significance.

PubMed

Perlman, Gidon Y; Loncar, Sasa; Pollak, Arthur; Gilon, Dan; Alcalai, Ronny; Planer, David; Lotan, Chaim; Danenberg, Haim D

2013-05-01

This study sought to investigate the blood pressure (BP) response after transcatheter aortic valve implantation (TAVI) and its correlation with short- and mid-term clinical outcomes. TAVI is an emerging therapy for aortic stenosis patients at high surgical risk. The acute hemodynamic sequelae of this procedure and their clinical relevance are yet unclear. Consecutive patients who underwent TAVI in a single center were prospectively monitored for BP response during 5 post-procedural days. Clinical parameters, adverse events, and medical treatment were recorded during hospitalization, at 30 days, and at 12 months after the procedure. Patients were divided according to their post-procedural BP response into 2 groups: increased BP and stable BP. One hundred and five patients were analyzed. Overall, systolic BP increased immediately after TAVI in the entire cohort by an average of 15 ± 31 mm Hg. This rise was sustained and led to intensification of antihypertensive treatment in 53 patients (51%); these patients were designated as the increased BP group. The increase in systolic BP after TAVI was associated with an increase in stroke volume and cardiac output and was not related to age, baseline cardiac function, or procedural outcomes. Patients with increased BP after TAVI had a significantly better prognosis with fewer adverse events in the hospital (21% vs. 62%, p < 0.01), after 30 days (30% vs. 71%, p < 0.01), and after 12 months (53% vs. 83%, p < 0.01) as compared with patients with stable BP. After TAVI, a substantial number of patients have a significant rise in systolic BP necessitating long-term treatment. This increase in BP is associated with an increase in cardiac output and predicts a better clinical outcome. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Differential Influence of Distinct Components of Increased Blood Pressure on Cardiovascular OutcomesR3

PubMed Central

Cheng, Susan; Gupta, Deepak K.; Claggett, Brian; Sharrett, A. Richey; Shah, Amil M.; Skali, Hicham; Takeuchi, Madoka; Ni, Hanyu; Solomon, Scott D.

2013-01-01

Elevation in blood pressure (BP) increases risk for all cardiovascular events. Nevertheless, the extent to which different indices of BP elevation may be associated to varying degrees with different cardiovascular outcomes remains unclear. We studied 13,340 participants (aged 54±6 years, 56% women, 27% black) of the Atherosclerosis Risk in Communities Study who were free of baseline cardiovascular disease. We used Cox proportional hazards models to compare the relative contributions of systolic (SBP), diastolic (DBP), pulse pressure (PP), and mean arterial pressure (MAP) to risk for coronary heart disease (CHD), heart failure (HF), stroke, and all-cause mortality. For each multivariable-adjusted model, the largest area under the receiver-operating curve (AUC) and smallest -2 log likelihood values were used to identify BP measures with the greatest contribution to risk prediction for each outcome. A total of 2095 CHD events, 1669 HF events, 771 stroke events, and 3016 deaths occurred during up to 18±5 years of follow up. In multivariable analyses adjusting for traditional cardiovascular risk factors, the BP measures with the greatest risk contributions were: SBP for CHD (AUC=0.74); PP for HF (AUC=0.79), SBP for stroke (AUC=0.74), and PP for all-cause mortality (AUC=0.74). With few exceptions, results were similar in analyses stratified by age, sex, and race. Our data indicate that distinct BP components contribute variably to risk for different cardiovascular outcomes. PMID:23876475

Heinrich 0 at the Younger Dryas Termination Offshore Newfoundland

NASA Astrophysics Data System (ADS)

Pearce, C.; Andrews, J. T.; Jennings, A. E.; Bouloubassi, I.; Seidenkrantz, M. S.; Kuijpers, A.; Hillaire-Marcel, C.

2014-12-01

The last deglaciation was marked by intervals of rapid climatic fluctuations accompanied by glacial advances and retreats along the eastern edge of the Laurentide ice sheet. The most severe of these events, the Younger Dryas cold reversal, was accompanied by the major detrital carbonate (DC) event generally referred to as "Heinrich event 0" (H0) in the westernmost and southern Labrador Sea. A detrital carbonate layer was observed in a high resolution marine sediment record from southern Newfoundland and the onset of the event was dated to 11,600 ± 70 cal. yrs. BP (local ΔR = 140 yrs.). A variety of different proxies was applied to investigate the transport mechanisms for deposition of the layer and provenance of the carbonates. Elevated concentrations of dolomite and calcite based on quantitative X-ray diffraction measurements, combined with the presence of several mature petrogenic biomarkers limit the source of the H0 detrital input to Palaeozoic carbonate outcrops in north-eastern Canada. The event is attributed to the rapid ice retreat from the Hudson Strait directly following the warming at the onset of the Holocene. Based on additional proxy data published earlier from the same record, the event succeeded the early Holocene resumption of the Atlantic Meridional Overturning Circulation (AMOC), indicating that the Hudson Strait meltwater event had probably no significant impact on the AMOC. The detrital carbonate layer can be found in other marine sediment records along the Labrador Current pathway, from Hudson Strait to the Grand Banks and the southern Newfoundland slope. By using the onset of deposition of the carbonates as a time-synchronous marker, the DC layer has great potential for improving marine chronologies of late glacial age in the region and evaluating spatial variations in ΔR values.

Deglacial climatic oscillations in the Gulf of California

NASA Astrophysics Data System (ADS)

Keigwin, L. D.; Jones, G. A.

1990-12-01

A high-resolution, accelerator radiocarbon dated climate record of the interval 8,000-18,000 years B.P. from Deep Sea Drilling Project site 480 (Guaymas Basin, Gulf of California) shows geochemical and lithological oscillations of oceanographic and climatic significance during deglaciation. Nonlaminated sediments are associated with cooler climatic conditions during the late glacial (up to 13,000 years B.P.), and from 10,300 to 10,800 years B.P., equivalent to the Younger Dryas event of the North Atlantic region. We propose that the changes from laminated (varved) to nonlaminated sediments resulted from increased oxygen content in Pacific intermediate waters during the glacial and the Younger Dryas episodes, and that the forcing for the latter event was global in scope. Prominent events of low δ18O are recorded in benthic foraminifera from 8,000 to 10,000 and at 12,000 years B.P.; evidence for an earlier event between 13,500 and 15,000 years B.P. is weaker. Maximum δ18O is found to have occurred 10,500, 13,500, and 15,000 years ago (and beyond). Oxygen isotopic variability most likely reflects changing temperature and salinity characteristics of Pacific waters of intermediate depth during deglaciation or environmental changes within the Gulf of California region. Several lines of evidence suggest that during deglaciation the climate of the American southwest was marked by increased precipitation that could have lowered salinity in the Gulf of California. Recent modelling studies show that cooling of the Gulf of Mexico due to glacial meltwater injection, which is believed to have occurred at least twice during deglaciation, would have resulted in increased precipitation with respect to evaporation in the American southwest during summertime. The timing of deglacial events in the Gulf of Mexico and the Gulf of California supports such an atmospheric teleconnection.

Evidence for millennial-scale climate change during marine isotope stages 2 and 3 at Little Lake, Western Oregon, U.S.A.

USGS Publications Warehouse

Grigg, L.D.; Whitlock, C.; Dean, W.E.

2001-01-01

Pollen and geochemical data from Little Lake, western Oregon, suggest several patterns of millennial-scale environmental change during marine isotope stage (MIS) 2 (14,100-27,600 cal yr B.P.) and the latter part of MIS 3 (27,600-42,500 cal yr B.P.). During MIS 3, a series of transitions between warm- and cold-adapted taxa indicate that temperatures oscillated by ca. 2??-4??C every 1000-3000 yr. Highs and lows in summer insolation during MIS 3 are generally associated with the warmest and coldest intervals. Warm periods at Little Lake correlate with warm sea-surface temperatures in the Santa Barbara Basin. Changes in the strength of the subtropical high and the jet stream may account for synchronous changes at the two sites. During MIS 2, shifts between mesic and xeric subalpine forests suggest changes in precipitation every 1000-3000 yr. Increases in Tsuga heterophylla pollen at 25,000 and 22,000 cal yr B.P. imply brief warmings. Minimum summer insolation and maximum global ice-volumes during MIS 2 correspond to cold and dry conditions. Fluctuations in precipitation at Little Lake do not correlate with changes in the Santa Barbara Basin and may be explained by variations in the strength of the glacial anticyclone and the position of the jet stream. ?? 2001 University of Washington.

Effects of Gui Zhi Ma Huang Ge Ban Tang on the TLR7 Pathway in Influenza Virus Infected Mouse Lungs in a Cold Environment

PubMed Central

Shi, Shan-Shan; Fu, Ying-Jie; Yan, Yu-Qi; Wu, Sha; Tang, Xiao-Long

2018-01-01

Objective We wished to investigate the effects of the traditional Chinese medicine Gui Zhi Ma Huang Ge Ban Tang on controlling influenza A virus (IAV) infection and improving inflammation in mouse lungs. Method Mice were maintained in normal and cold environments and infected with IAV by intranasal application, respectively. Real-time quantitative polymerase chain reaction was used to measure mRNA expression of TLR7, myeloid differentiation primary response 88 (MyD88), and nuclear factor-kappa B (NF-κB)p65 in the TLR7 signaling pathway and virus replication in lungs. Western blotting was used to measure expression levels of TLR7, MyD88, and NF-κB p65 proteins. Flow cytometry was used to detect the proportion of T-helper (Th)1/Th2 and Th17/T-regulatory (Treg) cells. Results Application of Gui Zhi Ma Huang Ge Ban Tang in influenza-infected mice in a cold environment showed (i) downregulation of TLR7, MyD88, and NF-κBp65; (ii) inhibition of transcriptional activities of promoters coding for TLR7, MyD88, and NF-κBp65; (iii) reduction in the proportion of Th1/Th2 and Th17/Treg cells. Conclusions Gui Zhi Ma Huang Ge Ban Tang had a good therapeutic effect on mice infected with IAV, especially in the cold environment. It could reduce lung inflammation in mice significantly and elicit an anti-influenza effect by downregulating expression of the key factors in TLR7 signaling pathway.

Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia

NASA Astrophysics Data System (ADS)

Mackay, Anson W.; Bezrukova, Elena V.; Leng, Melanie J.; Meaney, Miriam; Nunes, Ana; Piotrowska, Natalia; Self, Angela; Shchetnikov, Alexander; Shilland, Ewan; Tarasov, Pavel; Wang, Luo; White, Dustin

2012-05-01

Boreal ecosystems are highly vulnerable to climate change, and severe ecological impacts in the near future are virtually certain to occur. We undertook a multiproxy study on an alpine lake (ESM-1) at the modern tree-line in boreal, southern Siberia. Steppe and tundra biomes were extensive in eastern Sayan landscapes during the early Holocene. Boreal forest quickly expanded by 9.1 ka BP, and dominated the landscape until c 0.7 ka BP, when the greatest period of compositional turnover occurred. At this time, alpine meadow landscape expanded and Picea obovata colonised new habitats along river valleys and lake shorelines, because of prevailing cool, moist conditions. During the early Holocene, chironomid assemblages were dominated by cold stenotherms. Diatoms for much of the Holocene were dominated by alkaliphilous, fragilarioid taxa, up until 0.2 ka BP, when epiphytic species expanded, indicative of increased habitat availability. C/N mass ratios ranged between 9.5 and 13.5 (11.1-15.8 C/N atomic ratios), indicative of algal communities dominating organic matter contributions to bottom sediments with small, persistent contributions from vascular plants. However, δ13C values increased steadily from -34.9‰ during the early Holocene (9.3 ka BP) to -24.8‰ by 0.6 ka BP. This large shift in magnitude may be due to a number of factors, including increasing within-lake productivity, increasing disequilibrium between the isotopic balance of the lake with the atmosphere as the lake became isotopically ‘mature’, and declining soil respiration linked to small, but distinct retreat in forest biomes. The influence of climatic variables on landscape vegetation was assessed using redundancy analysis (RDA), a linear, direct ordination technique. Changes in July insolation at 60 °N significantly explained over one-fifth of the variation in species composition, while changes in estimates of northern hemisphere temperature and ice-rafted debris events in the North Atlantic were also significant, but considerably less important. The potential importance of climate and biome development (tundra, steppe, cold deciduous forest and taiga) on different trophic levels (i.e. chironomid and diatom communities) in lake ESM-1 was also assessed using RDA. Climate predictors had a more significant influence on Holocene chironomid assemblages, especially July insolation at 60 °N, estimates of regional precipitation and estimates of northern hemisphere temperature, while only the development of the taiga biome had a significant impact on these primary consumers. Diatom communities also had a small, but significant influence on Holocene chironomid populations, perhaps linked to variation in faunal feeding strategies. In contrast, climatic and biome predictors explained similar amounts of variation in the Holocene diatom assemblage (approximately 20% each), while chironomids themselves as predictors explained just under 7% of diatom variation. Lake acidity was inferred using a diatom inference model. Results suggest that after deglaciation, the lake did not undergo a process of gradual acidification, most likely due to the presence of continuous permafrost and low levels of precipitation, preventing base cations and dissolved organic carbon entering the lake (except for the period between 1.7 and 0.7 ka BP). We conclude that lakes in continental, boreal regions undergo different models of lake ontogeny than oceanic boreal regions. Unlike other regions discussed, climate is a more important driver of ecosystem change than catchment changes. We also demonstrate that the start of the period coincident with the onset of the Little Ice Age resulted in important thresholds crossed in catchment vegetation and aquatic communities.

Black p-branes versus black holes in non-asymptotically flat Einstein-Yang-Mills theory

NASA Astrophysics Data System (ADS)

Habib Mazharimousavi, S.; Halilsoy, M.

2016-09-01

We present a class of non-asymptotically flat (NAF) charged black p-branes (BpB) with p-compact dimensions in higher-dimensional Einstein-Yang-Mills theory. Asymptotically the NAF structure manifests itself as an anti-de sitter spacetime. We determine the total mass/energy enclosed in a thin shell located outside the event horizon. By comparing the entropies of BpB with those of black holes in the same dimensions we derive transition criteria between the two types of black objects. Given certain conditions satisfied, our analysis shows that BpB can be considered excited states of black holes. An event horizon r+ versus charge square Q2 plot for the BpB reveals such a transition where r+ is related to the horizon radius rh of the black hole (BH) both with the common charge Q.

Visit-to-visit variability of blood pressure and cardiovascular outcomes in patients with stable coronary heart disease. Insights from the STABILITY trial.

PubMed

Vidal-Petiot, Emmanuelle; Stebbins, Amanda; Chiswell, Karen; Ardissino, Diego; Aylward, Philip E; Cannon, Christopher P; Ramos Corrales, Marco A; Held, Claes; López-Sendón, José Luis; Stewart, Ralph A H; Wallentin, Lars; White, Harvey D; Steg, Philippe Gabriel

2017-10-01

To study the relation between visit-to-visit variability of blood pressure (BP) and cardiovascular risk in patients with stable coronary heart disease. In 15 828 patients from the STABILITY trial (darapladib vs. placebo in patients with established coronary heart disease), BP variability was assessed by the standard deviation (SD) of systolic BP, the SD of diastolic BP, maximum BP, and minimum BP, from 5 measurements (baseline and months 1, 3, 6, and 12) during the first year after randomisation. Mean (SD) average BP during the first year of study was 131.0 (13.7) mmHg over 78.3 (8.3) mmHg. Mean (SD) of the visit-to-visit SD was 9.8 (4.8) mmHg for systolic and 6.3 (3.0) mmHg for diastolic BP. During the subsequent median follow-up of 2.6 years, 1010 patients met the primary endpoint, a composite of time to cardiovascular death, myocardial infarction, or stroke. In Cox regression models adjusted for average BP during first year of study, baseline vascular disease, treatment, renal function and cardiovascular risk factors, the primary endpoint was associated with SD of systolic BP (hazard ratio for highest vs. lowest tertile, 1.30, 95% CI 1.10-1.53, P = 0.007), and with SD of diastolic BP (hazard ratio for highest vs. lowest tertile, 1.38, 95% CI 1.18-1.62, P < 0.001). Peaks and troughs in BP were also independently associated with adverse events. In patients with stable coronary heart disease, higher visit-to-visit variabilities of both systolic and diastolic BP are strong predictors of increased risk of cardiovascular events, independently of mean BP. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

BP180 Is Critical in the Autoimmunity of Bullous Pemphigoid

PubMed Central

Liu, Yale; Li, Liang; Xia, Yumin

2017-01-01

Bullous pemphigoid (BP) is by far the most common autoimmune blistering dermatosis that mainly occurs in the elderly. The BP180 is a transmembrane glycoprotein, which is highly immunodominant in BP. The structure and location of BP180 indicate that it is a significant autoantigen and plays a key role in blister formation. Autoantibodies from BP patients react with BP180, which leads to its degradation and this has been regarded as the central event in BP pathogenesis. The consequent blister formation involves the activation of complement-dependent or -independent signals, as well as inflammatory pathways induced by BP180/anti-BP180 autoantibody interaction. As a multi-epitope molecule, BP180 can cause dermal–epidermal separation via combining each epitope with specific immunoglobulin, which also facilitates blister formation. In addition, some inflammatory factors can directly deplete BP180, thereby leading to fragility of the dermal–epidermal junction and blister formation. This review summarizes recent investigations on the role of BP180 in BP pathogenesis to determine the potential targets for the treatment of patients with BP. PMID:29276517

Breast-feeding and maternal cardiovascular function.

PubMed

Mezzacappa, E S; Kelsey, R M; Myers, M M; Katkin, E S

2001-11-01

Two studies examined the effects of breast-feeding on maternal cardiovascular function. In the first experiment, groups of breast-feeding and bottle-feeding women were compared on preejection period (PEP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR) recorded for 1-min periods before and during standard laboratory stressors. Compared with bottle-feeders, breast-feeders had higher CO throughout the session, and greater decreases in CO and increases in TPR during cold pressor. In the second experiment, HR and blood pressure (BP) were compared before and after one breast-feeding and one bottle-feeding session in a within-subjects design. Both feeding methods increased BP but decreased HR, and systolic BP was higher for the breast-feeding than the bottle-feeding condition. Both studies support the notion that breast-feeding alters maternal cardiovascular function, possibly through the actions of oxytocin.

Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin

PubMed Central

do Carmo, Jussara M.; da Silva, Alexandre A.; Romero, Damian G.; Hall, John E.

2017-01-01

Interactions of hypothalamic signaling pathways that control body temperature (BT), blood pressure (BP), and energy balance are poorly understood. We investigated whether the chronic BP and metabolic actions of leptin are differentially modulated by changes in ambient temperature (TA). Mean arterial pressure (MAP), heart rate (HR), BT, motor activity (MA), and oxygen consumption (Vo2) were measured 24 h/d at normal laboratory TA (23°C), at thermoneutral zone (TNZ, 30°C) for mice or during cold exposure (15°C) in male wild-type mice. After control measurements, leptin (4 μg/kg/min) or saline vehicle was infused for 7 d. At TNZ, leptin reduced food intake (−11.0 ± 0.5 g cumulative deficit) and body weight by 6% but caused no changes in MAP or HR. At 15°C, leptin infusion did not alter food intake but increased MAP and HR (8 ± 1 mmHg and 33 ± 7 bpm), while Vo2 increased by ∼10%. Leptin reduced plasma glucose and insulin levels at 15°C but not at 30°C. These results demonstrate that the chronic anorexic effects of leptin are enhanced at TNZ, while its effects on insulin and glucose levels are attenuated and its effects on BP and HR are abolished. Conversely, cold TA caused resistance to leptin’s anorexic effects but amplified its effects to raise BP and reduce insulin and glucose levels. Thus, the brain circuits by which leptin regulates food intake and cardiovascular function are differentially influenced by changes in TA.—Do Carmo, J. M., da Silva, A. A., Romero, D. G., Hall, J. E. Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin. PMID:28228474

SYMPATHETIC NEURAL AND HEMODYNAMIC RESPONSES DURING COLD PRESSOR TEST IN ELDERLY BLACKS AND WHITES

PubMed Central

Okada, Yoshiyuki; Jarvis, Sara S.; Best, Stuart A.; Edwards, Jeffrey G.; Hendrix, Joseph M.; Adams-Huet, Beverley; Vongpatanasin, Wanpen; Levine, Benjamin D.; Fu, Qi

2016-01-01

The sympathetic response during the cold pressor test (CPT) has been reported to be greater in young blacks than whites, especially in those with a family history of hypertension. Since blood pressure (BP) increases with age, we evaluated whether elderly blacks have greater sympathetic activation during CPT than age-matched whites. BP, heart rate (HR), cardiac output (Qc), and muscle sympathetic nerve activity (MSNA) were measured during supine baseline, 2-min CPT, and 3-min recovery in 47 elderly [68±7 (SD) yrs] volunteers (12 blacks, 35 whites). Baseline BP, HR, Qc, or MSNA did not differ between races. Systolic and diastolic BP (DBP) and HR increased during CPT (all P<0.001) with no racial differences (all P>0.05). Qc increased during CPT and up to 30 sec of recovery in both groups, but was lower in blacks than whites. MSNA increased during CPT in both groups (both P<0.001); the increase in burst frequency was similar between groups, while the increase in total activity was smaller in blacks (P=0.030 for interaction). Peak change (Δ) in DBP was correlated with Δ total activity at 1 min into CPT in both blacks (r=0.78, P=0.003) and whites (r=0.43, P=0.009), while the slope was significantly greater in blacks (P=0.007). Thus, elderly blacks have smaller sympathetic and central hemodynamic (e.g., Qc) responses, but a greater pressor response for a given sympathetic activation during CPT than elderly whites. This response may stem from augmented sympathetic vascular transduction, greater sympathetic activation to other vascular bed(s), and/or enhanced non-adrenergically mediated vasoconstriction in elderly blacks. PMID:27021009

Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin.

PubMed

do Carmo, Jussara M; da Silva, Alexandre A; Romero, Damian G; Hall, John E

2017-06-01

Interactions of hypothalamic signaling pathways that control body temperature (BT), blood pressure (BP), and energy balance are poorly understood. We investigated whether the chronic BP and metabolic actions of leptin are differentially modulated by changes in ambient temperature ( T A ). Mean arterial pressure (MAP), heart rate (HR), BT, motor activity (MA), and oxygen consumption ( V o 2 ) were measured 24 h/d at normal laboratory T A (23°C), at thermoneutral zone (TNZ, 30°C) for mice or during cold exposure (15°C) in male wild-type mice. After control measurements, leptin (4 μg/kg/min) or saline vehicle was infused for 7 d. At TNZ, leptin reduced food intake (-11.0 ± 0.5 g cumulative deficit) and body weight by 6% but caused no changes in MAP or HR. At 15°C, leptin infusion did not alter food intake but increased MAP and HR (8 ± 1 mmHg and 33 ± 7 bpm), while V o 2 increased by ∼10%. Leptin reduced plasma glucose and insulin levels at 15°C but not at 30°C. These results demonstrate that the chronic anorexic effects of leptin are enhanced at TNZ, while its effects on insulin and glucose levels are attenuated and its effects on BP and HR are abolished. Conversely, cold T A caused resistance to leptin's anorexic effects but amplified its effects to raise BP and reduce insulin and glucose levels. Thus, the brain circuits by which leptin regulates food intake and cardiovascular function are differentially influenced by changes in T A -Do Carmo, J. M., da Silva, A. A., Romero, D. G., Hall, J. E. Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin. © FASEB.

South Asian climate change at the end of urban Harappan (Indus valley) civilization and mechanisms of Holocene monsoon variability

NASA Astrophysics Data System (ADS)

Staubwasser, M.; Sirocko, F.; Erlenkeuser, H.; Grootes, P. M.; Segl, M.

2003-04-01

Planktonic oxygen isotope ratios from the well-dated laminated sediment core 63KA off the river Indus delta are presented. The record reveals significant climate changes in the south Asian monsoon system throughout the Holocene. The most prominent event of the early-mid Holocene occurred after 8.4 ka BP and is within dating error of the GISP/GRIP event centered at 8.2 ka BP. The late Holocene is generally more variable and the largest change of the entire Holocene occurred at 4.2 ka BP. This event is concordant with the end of urban Harappan civilization in the Indus valley. Opposing isotopic trends across the northern Arabian Sea surface indicate a reduction in Indus river discharge at that time. Consequently, sustained drought may have initiated the archaeologically recorded interval of southeastward habitat tracking within the Harappan cultural domain. The hemispheric significance of the 4.2 ka BP event is evident from concordant climate change in the eastern Mediterranean and the Middle East. The remainder of the late Holocene shows drought cycles of approximately 700 years that are coherent with the evolution of cosmogenic radiocarbon production rates in the atmosphere. This suggests that solar variability is one fundamental cause behind late Holocene rainfall changes over south Asia.

How Many Measurements Are Needed to Estimate Blood Pressure Variability Without Loss of Prognostic Information?

PubMed Central

2014-01-01

BACKGROUND Average real variability (ARV) is a recently proposed index for short-term blood pressure (BP) variability. We aimed to determine the minimum number of BP readings required to compute ARV without loss of prognostic information. METHODS ARV was calculated from a discovery dataset that included 24-hour ambulatory BP measurements for 1,254 residents (mean age = 56.6 years; 43.5% women) of Copenhagen, Denmark. Concordance between ARV from full (≥80 BP readings) and randomly reduced 24-hour BP recordings was examined, as was prognostic accuracy. A test dataset that included 5,353 subjects (mean age = 54.0 years; 45.6% women) with at least 48 BP measurements from 11 randomly recruited population cohorts was used to validate the results. RESULTS In the discovery dataset, a minimum of 48 BP readings allowed an accurate assessment of the association between cardiovascular risk and ARV. In the test dataset, over 10.2 years (median), 806 participants died (335 cardiovascular deaths, 206 cardiac deaths) and 696 experienced a major fatal or nonfatal cardiovascular event. Standardized multivariable-adjusted hazard ratios (HRs) were computed for associations between outcome and BP variability. Higher diastolic ARV in 24-hour ambulatory BP recordings predicted (P < 0.01) total (HR = 1.12), cardiovascular (HR = 1.19), and cardiac (HR = 1.19) mortality and fatal combined with nonfatal cerebrovascular events (HR = 1.16). Higher systolic ARV in 24-hour ambulatory BP recordings predicted (P < 0.01) total (HR = 1.12), cardiovascular (HR = 1.17), and cardiac (HR = 1.24) mortality. CONCLUSIONS Forty-eight BP readings over 24 hours were observed to be adequate to compute ARV without meaningful loss of prognostic information. PMID:23955605

The J-shaped Curve for Blood Pressure and Cardiovascular Disease Risk: Historical Context and Recent Updates.

PubMed

Rahman, Faisal; McEvoy, John W

2017-08-01

The definition and treatment of hypertension have both changed dramatically over the last century, with recent trials suggesting benefit for lower blood pressure (BP) targets than ever before considered. However, tempering the enthusiasm for more intensive BP targets are long-held concerns that BP reduction below a certain threshold may pose dangers, the so-called "J-curve." In this review, we summarize the evidence for a J-curve in the treatment of hypertension. The Systolic Blood Pressure Intervention Trial (SPRINT) reported that achieving a systolic BP target of 120 mmHg reduces cardiovascular disease in high-risk individuals, supporting more intensive BP reduction. However, contemporary observational studies consistently demonstrate a BP J-curve, the threshold of which is often close to the SPRINT target. Studies also suggest that the BP level of this J-curve may vary based on patient characteristics, including age and comorbidities. There is also more compelling evidence for the specific presence of a J-curve between diastolic BP and coronary events, in contrast to conflicting evidence of a J-curve with systolic BP and cardiovascular disease more generally. There is increased risk of coronary events below a diastolic BP of 60-70 mmHg. In comparison, the presence of a systolic J-curve is less clear and some persons at high risk may actually benefit from systolic levels down to 120 mmHg. Therefore, we suggest a personalized approach to BP management considering individual risks, benefits, and preferences when choosing therapeutic targets. Further, well-designed studies are required to support our suggestions and to define J-curve thresholds more clearly.

Transcriptome profiling of Vitis amurensis, an extremely cold-tolerant Chinese wild Vitis species, reveals candidate genes and events that potentially connected to cold stress.

PubMed

Xu, Weirong; Li, Ruimin; Zhang, Ningbo; Ma, Fuli; Jiao, Yuntong; Wang, Zhenping

2014-11-01

Vitis amurensis Rupr. is an exceptional wild-growing Vitis (grape) species that can safely survive a wide range of cold conditions, but the underlying cold-adaptive mechanism associated with gene regulation is poorly investigated. We have analyzed the physiochemical and transcriptomic changes caused by cold stress in a cold-tolerant accession, 'Heilongjiang seedling', of Chinese wild V. amurensis. We statistically determined that a total of 6,850 cold-regulated transcripts were involved in cold regulation, including 3,676 up-regulated and 3,174 down-regulated transcripts. A global survey of messenger RNA revealed that skipped exon is the most prevalent form of alternative spicing event. Importantly, we found that the total splicing events increased with the prolonged cold stress. We also identified thirty-eight major TF families that were involved in cold regulation, some of which were previously unknown. Moreover, a large number of candidate pathways for the metabolism or biosynthesis of secondary metabolites were found to be regulated by cold, which is of potential importance in coordinating cold tolerance with growth and development. Several heat shock proteins and heat shock factors were also detected to be intensively cold-regulated. Furthermore, we validated the expression profiles of 16 candidates using qRT-PCR to further confirm the accuracy of the RNA-seq data. Our results provide a genome-wide view of the dynamic changes in the transcriptome of V. amurensis, in which it is evident that various structural and regulatory genes are crucial for cold tolerance/adaptation. Moreover, our robust dataset advances our knowledge of the genes involved in the complex regulatory networks of cold stress and leads to a better understanding of cold tolerance mechanisms in this extremely cold-tolerant Vitis species.

Home, automated office, and conventional office blood pressure as predictors of cardiovascular risk.

PubMed

Andreadis, Emmanuel A; Papademetriou, Vasilios; Geladari, Charalampia V; Kolyvas, George N; Angelopoulos, Epameinondas T; Aronis, Konstantinos N

2017-03-01

Automated office blood pressure (AOBP) has recently been shown to closely predict cardiovascular (CV) events in the elderly. Home blood pressure (HBP) has also been accepted as a valuable method in the prediction of CV disease. This study aimed to compare conventional office BP (OBP), HBP, and AOBP in order to evaluate their value in predicting CV events and deaths in hypertensives. We assessed 236 initially treatment naïve hypertensives, examined between 2009 and 2013. The end points were any CV and non-CV event including mortality, myocardial infarction, coronary heart disease, hospitalization for heart failure, severe arrhythmia, stroke, and intermittent claudication. We fitted proportional hazards models using the different modalities as predictors and evaluated their predictive performance using three metrics: time-dependent receiver operating characteristics curves, the Akaike's Information Criterion, and Harrell's C-index. After a mean follow-up of 7 years, 23 participants (39% women) had experienced ≥1 CV event. Conventional office systolic (hazard ratio [HR] per 1 mm Hg increase in BP, 1.028; 95% confidence interval [CI], 1.009-1.048), automated office systolic (HR per 1 mm Hg increase in BP, 1.031; 95% CI, 1.008-1.054), and home systolic (HR, 1.025; 95% CI, 1.003-1.047) were predictive of CV events. All systolic BP measurements were predictive after adjustment for other CV risk factors (P < .05). The predictive performance of the different modalities was similar. Conventional OBP was significantly higher than AOBP and average HBP. AOBP predicts equally well to OBP and HBP CV events. It appears to be comparable to HBP in the assessment of CV risk, and therefore, its introduction into guidelines and clinical practice as the reference method for assessing BP in the office seems reasonable after verification of these findings by randomized trials. Copyright © 2017 American Society of Hypertension. All rights reserved.

Blood pressure circadian rhythms and adverse outcomes in type 2 diabetes patients diagnosed with orthostatic hypotension.

PubMed

Chang, Jing; Hou, Yuan-Ping; Wu, Jin-Ling; Fang, Xiang-Yang; Li, Sheng-Li; Liu, Miao-Bing; Sun, Qian-Mei

2018-03-01

Patients with diabetes frequently develop orthostatic hypotension (OH). The present study was designed to examine the relationship of blood pressure (BP) circadian rhythms and outcomes in diabetes with OH. In the present study, 173 inpatients with type 2 diabetes were enrolled. Patients were divided into an OH group and a non-OH group according to the BP changes detected in the supine and standing position. Then, 24-h ambulatory BP was monitored. Patients were followed up for an average of 45 ± 10 months post-discharge. Outcomes - death and major adverse cardiac and cerebrovascular events, including heart failure, myocardial infarction and stroke - were recorded. There were 61 patients (35.26%) in the OH group and 112 patients (64.74%) in the non-OH group. In the OH group, the night-time systolic BP and night-time diastolic BP were higher, the blood BP rhythms were predominantly of the riser type (67.21%). OH was as an independent marker of riser type circadian rhythm (adjusted odds ratio 4.532, 95% confidence interval 2.579-7.966). In the OH group, the incidence rates of mortality, and major adverse cardiac and cerebrovascular events were increased significantly compared with those in the non-OH group (11.48 vs 2.68%, P = 0.014; 37.70 vs 8.93%, P < 0.01). In patients who had type 2 diabetes diagnosed with OH, the BP circadian rhythm usually showed riser patterns, and they had increased rates of mortality, and major adverse cardiac and cerebrovascular events. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Community Response to a Heavy Precipitation Event in High Temperature, Chemosynthetic Biofilms and Sediments

NASA Astrophysics Data System (ADS)

Meyer-Dombard, D. R.; Loiacono, S. T.; Shock, E.

2012-12-01

Coordinated analysis of the "Bison Pool" (BP) Environmental Genome and a complementary contextual geochemical dataset of ~75 parameters revealed biogeochemical cycling and metabolic and microbial community shifts in a Yellowstone National Park hot spring ecosystem (1). The >22m outflow of BP is a gradient of decreasing temperature, increasing dissolved oxygen, and changing availability of nutrients. Microbial life at BP transitions from a 92°C chemosynthetic community in the BP source pool to a 56°C photosynthetic mat community. Metagenomic data at BP showed the potential for both heterotrophic and autotrophic carbon metabolism (rTCA and acetyl-CoA cycles) in the highest temperature, chemosynthetic regions (1). This region of the outflow is dominated by Aquificales and Pyrococcus relatives, with smaller contributions of heterotrophic Bacteria. Following a 2h heavy precipitation event we observed an influx of exogenous organic material into the source pool supplied from the meadow surrounding the BP area. We sampled biomass and fluid at several locations within the outflow immediately following the event, and on several occasions for the next eight days. Elemental analysis and carbon and nitrogen isotopic analyses were conducted on biomass and sediment, and dissolved organic and inorganic carbon content and δ13C of fluids were analyzed. DNA and RNA were extracted, and following RT-PCR, nitrogen cycle functional gene expression was evaluated. Previous work at BP has shown that chemosynthetic biomass may carry isotopic signatures of fractionation during carbon fixation, via the acetyl-CoA and rTCA cycles (2). However, the addition of exogenous organic carbon during the rain event had an immediate and dramatic effect on the sediments and biofilms in the chemosynthetic zone of the outflow. Dissolved organic carbon was the highest measured in six years. Chemosynthetic biomass responded by incorporating the organic carbon. Carbon isotopic signatures in chemosynthetic biomass at "Bison Pool" have been previously measured at ~ -4‰ (2). However, immediately following the event, carbon in biomass was measured at ~ -25‰ (values similar to local soil and bison excrement). Biomass closest to the source of "Bison Pool" returned to ~ -4‰ within a few days, but biomass ~ 3m downstream was still ~ -14‰ eight days after the event. Carbon isotopic signatures of the dissolved inorganic carbon (DIC) were depleted relative to values measured in 2005-2009, possibly a result of a combination of added DIC in rain and heterotrophic waste produced using the exogenous depleted carbon; this depleted DIC persisted for the full study period. These results suggest that a shift from autotrophic to heterotrophic metabolism may occur following every significant precipitation event at BP, and support previous observations concerning potential periodic eutrophic conditions in this ecosystem (3). 1 Swingley, W.D. et al., PLoS ONE, 7(6): e38108. 2 Havig et al., 2011. JGR Biogeosciences, 116, G01005. 3 Loiacono, S.T. et al., 2012. EM, 14(5): 1272-1283.

Multi-scale Holocene Asian monsoon variability deduced from a twin-stalagmite record in southwestern China

NASA Astrophysics Data System (ADS)

Huang, Wei; Wang, Yongjin; Cheng, Hai; Edwards, Richard Lawrence; Shen, Chuan-Chou; Liu, Dianbing; Shao, Qingfeng; Deng, Chao; Zhang, Zhenqiu; Wang, Quan

2016-07-01

We present two isotopic (δ18O and δ13C) sequences of a twin-stalagmite from Zhuliuping Cave, southwestern China, with 230Th dates from 14.6 to 4.6 ka. The stalagmite δ18O record characterizes orbital- to decadal-scale variability of Asian summer monsoon (ASM) intensity, with the Holocene optimum period (HOP) between 9.8 and 6.8 ka BP which is reinforced by its co-varying δ13C data. The large multi-decadal scale amplitude of the cave δ18O indicates its high sensitivity to climate change. Four centennial-scale weak ASM events during the early Holocene are centered at 11.2, 10.8, 9.1 and 8.2 ka. They can be correlated to cold periods in the northern high latitudes, possibly resulting from rapid dynamics of atmospheric circulation associated with North Atlantic cooling. The 8.2 ka event has an amplitude more than two-thirds that of the Younger Dryas (YD), and is significantly stronger than other cave records in the Asia monsoon region, likely indicating a more severe dry climate condition at the cave site. At the end of the YD event, the δ13C record lags the δ18O record by 300-500 yr, suggesting a multi-centennial slow response of vegetation and soil processes to monsoon enhancement.

Association Between Blood Pressure Control and Risk of Recurrent Intracerebral Hemorrhage.

PubMed

Biffi, Alessandro; Anderson, Christopher D; Battey, Thomas W K; Ayres, Alison M; Greenberg, Steven M; Viswanathan, Anand; Rosand, Jonathan

2015-09-01

Intracerebral hemorrhage (ICH) is the most severe form of stroke. Survivors are at high risk of recurrence, death, and worsening functional disability. To investigate the association between blood pressure (BP) after index ICH and risk of recurrent ICH. Single-site, tertiary care referral center observational study of 1145 of 2197 consecutive patients with ICH presenting from July 1994 to December 2013. A total of 1145 patients with ICH survived at least 90 days and were followed up through December 2013 (median follow-up of 36.8 months [minimum, 9.8 months]). Blood pressure measurements at 3, 6, 9, and 12 months, and every 6 months thereafter, obtained from medical personnel (inpatient hospital or outpatient clinic medical or nursing staff) or via patient self-report. Exposure was characterized in 3 ways: (1) recorded systolic and diastolic measurements; (2) classification as adequate or inadequate BP control based on American Heart Association/American Stroke Association recommendations; and (3) stage of hypertension based on Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 7 criteria. Recurrent ICH and its location within the brain (lobar vs nonlobar). There were 102 recurrent ICH events among 505 survivors of lobar ICH and 44 recurrent ICH events among 640 survivors of nonlobar ICH. During follow-up adequate BP control was achieved on at least 1 measurement by 625 patients (54.6% of total [range, 49.2%-58.7%]) and consistently (ie, at all available time points) by 495 patients (43.2% of total [range, 34.5%-51.0%]). The event rate for lobar ICH was 84 per 1000 person-years among patients with inadequate BP control compared with 49 per 1000 person-years among patients with adequate BP control. For nonlobar ICH the event rate was 52 per 1000 person-years with inadequate BP control compared with 27 per 1000 person-years for patients with adequate BP control. In analyses modeling BP control as a time-varying variable, inadequate BP control was associated with higher risk of recurrence of both lobar ICH (hazard ratio [HR], 3.53 [95% CI, 1.65-7.54]) and nonlobar ICH (HR, 4.23 [95% CI, 1.02-17.52]). Systolic BP during follow-up was associated with increased risk of both lobar ICH recurrence (HR, 1.33 per 10-mm Hg increase [95% CI, 1.02-1.76]) and nonlobar ICH recurrence (HR, 1.54 [95% CI, 1.03-2.30]). Diastolic BP was associated with increased risk of nonlobar ICH recurrence (HR, 1.21 per 10-mm Hg increase [95% CI, 1.01-1.47]) but not with lobar ICH recurrence (HR, 1.36 [95% CI, 0.90-2.10]). In this observational single-center cohort study of ICH survivors, reported BP measurements suggesting inadequate BP control during follow-up were associated with higher risk of both lobar and nonlobar ICH recurrence. These data suggest that randomized clinical trials are needed to address the benefits and risks of stricter BP control in ICH survivors.

Oxygen isotope records of Holocene climate variability in the Pacific Northwest

NASA Astrophysics Data System (ADS)

Steinman, Byron A.; Pompeani, David P.; Abbott, Mark B.; Ortiz, Joseph D.; Stansell, Nathan D.; Finkenbinder, Matthew S.; Mihindukulasooriya, Lorita N.; Hillman, Aubrey L.

2016-06-01

Oxygen isotope (δ18O) measurements of authigenic carbonate from Cleland Lake (southeastern British Columbia), Paradise Lake (central British Columbia), and Lime Lake (eastern Washington) provide a ∼9000 year Holocene record of precipitation-evaporation balance variations in the Pacific Northwest. Both Cleland Lake and Paradise Lake are small, surficially closed-basin systems with no active inflows or outflows. Lime Lake is surficially open with a seasonally active overflow. Water isotope values from Cleland and Paradise plot along the local evaporation line, indicating that precipitation-evaporation balance is a strong influence on lake hydrology. In contrast, Lime Lake water isotope values plot on the local meteoric water line, signifying minimal influence by evaporation. To infer past hydrologic balance variations at a high temporal resolution, we sampled the Cleland, Paradise, and Lime Lake sediment cores at 1-60 mm intervals (∼3-33 years per sample on average) and measured the isotopic composition of fine-grained (<63 μm) authigenic CaCO3 in each sample. Negative δ18O values, which indicate wetter conditions in closed-basin lakes, occur in Cleland Lake sediment from 7600 to 2200 years before present (yr BP), and are followed by more positive δ18O values, which suggest drier conditions, after 2200 yr BP. Highly negative δ18O values in the Cleland Lake record centered on ∼2400 yr BP suggest that lake levels were high (and that the lake may have been overflowing) at this time as a result of a substantially wetter climate. Similarly, Paradise Lake sediment δ18O values are relatively low from 7600 to 4000 yr BP and increase from ∼4000 to 3000 yr BP and from ∼2000 yr BP to present, indicating that climate became drier from the middle through the late Holocene. The δ18O record from Lime Lake, which principally reflects changes in the isotopic composition of precipitation, exhibits less variability than the closed-basin lake records and follows a generally increasing trend from the mid-Holocene to present. These results are consistent with several proximal reconstructions of changes in lake-level, precipitation amount, and precipitation isotopic composition and may also reflect the establishment of modern El Niño Southern Oscillation (ENSO) variability in the late Holocene, as inferred from proxy evidence of synoptic ocean-atmosphere changes in the Pacific basin. Results from mid-Holocene (6000 yr BP) climate model simulations conducted as part of the Paleoclimate Modeling Intercomparison Project Phase 3 (PMIP3) indicate that in much of western North America, the cold season (October-March) was wetter and the warm season (April-September) was considerably drier relative to the late Holocene, leading to an overall drier climate in western North America with enhanced hydroclimatic seasonality. This is consistent with inferences from the Cleland and Paradise δ18O records, which lake modeling experiments indicate are strongly influenced by cold season precipitation-evaporation balance. This also explains apparent inconsistencies between the lake δ18O records and other proxies of hydroclimatic change from the greater Pacific Northwest region that are less sensitive to cold season climate and thus indicate relatively drier conditions during the mid-Holocene. The abrupt negative excursion at ∼2400 yr BP in the Cleland Lake δ18O data, as well as the marked shift to more positive values after this time, demonstrate that gradual changes in ocean-atmosphere dynamics can produce abrupt, non-linear hydroclimate responses in the interior regions of western North America.

Large mid-Holocene and late Pleistocene earthquakes on the Oquirrh fault zone, Utah

USGS Publications Warehouse

Olig, S.S.; Lund, W.R.; Black, B.D.

1994-01-01

The Oquirrh fault zone is a range-front normal fault that bounds the east side of Tooele Valley and it has long been recognized as a potential source for large earthquakes that pose a significant hazard to population centers along the Wasatch Front in central Utah. Scarps of the Oquirrh fault zone offset the Provo shoreline of Lake Bonneville and previous studies of scarp morphology suggested that the most recent surface-faulting earthquake occurred between 9000 and 13,500 years ago. Based on a potential rupture length of 12 to 21 km from previous mapping, moment magnitude (Mw) estimates for this event range from 6.3 to 6.6 In contrast, our results from detailed mapping and trench excavations at two sites indicate that the most-recent event actually occurred between 4300 and 6900 yr B.P. (4800 and 7900 cal B.P.) and net vertical displacements were 2.2 to 2.7 m, much larger than expected considering estimated rupture lengths for this event. Empirical relations between magnitude and displacement yield Mw 7.0 to 7.2. A few, short discontinuous fault scarps as far south as Stockton, Utah have been identified in a recent mapping investigation and our results suggest that they may be part of the Oquirrh fault zone, increasing the total fault length to 32 km. These results emphasize the importance of integrating stratigraphic and geomorphic information in fault investigations for earthquake hazard evaluations. At both the Big Canyon and Pole Canyon sites, trenches exposed faulted Lake Bonneville sediments and thick wedges of fault-scarp derived colluvium associated with the most-recent event. Bulk sediment samples from a faulted debris-flow deposit at the Big Canyon site yield radiocarbon ages of 7650 ?? 90 yr B.P. and 6840 ?? 100 yr B.P. (all lab errors are ??1??). A bulk sediment sample from unfaulted fluvial deposits that bury the fault scarp yield a radiocarbon age estimate of 4340 ?? 60 yr B.P. Stratigraphic evidence for a pre-Bonneville lake cycle penultimate earthquake was exposed at the Pole Canyon site, and although displacement is not well constrained, the penultimate event colluvial wedge is comparable in size to the most-recent event wedges. Charcoal from a marsh deposit, which overlies the penultimate event colluvium and was deposited during the Bonneville lake cycle transgression, yields an AMS radiocarbon age of 20,370 ?? 120 yr B.P. Multiple charcoal fragments from fluvial deposits faulted during the penultimate event yield an AMS radiocarbon age of 26,200 ?? 200 yr B.P. Indirect stratigraphic evidence for an antepenultimate event was also exposed at Pole Canyon. Charcoal from fluvial sediments overlying the eroded free-face for this event yields an AMS age of 33,950 ?? 1160 yr B.P., providing a minimum limiting age on the antepenultimate event. Ages for the past two events on the Oquirrh fault zone yield a recurrence interval of 13,300 to 22,100 radiocarbon years and estimated slip rates of 0.1 to 0.2 mm/yr. Temporal clustering of earthquakes on the nearby Wasatch fault zone in the late Holocene does not appear to have influenced activity on the Oquirrh fault zone. However, consistent with findings on the Wasatch fault zone and with some other Quaternary faults within the Bonneville basin, we found evidence for higher rates of activity during interpluvial periods than during the Bonneville lake cycle. If a causal relation between rates of strain release along faults and changes in loads imposed by the lake does exist, it may have implications for fault dips and mechanics. However, our data are only complete for one deep-lake cycle (the past 32,000 radiocarbon years), and whether this pattern persisted during the previous Cutler Dam and Little Valley deep-lake cycles is unknown. ?? 1994.

Research and Development of Information and Communication Technology-based Home Blood Pressure Monitoring from Morning to Nocturnal Hypertension.

PubMed

Kario, Kazuomi; Tomitani, Naoko; Matsumoto, Yuri; Hamasaki, Haruna; Okawara, Yukie; Kondo, Maiko; Nozue, Ryoko; Yamagata, Hiromi; Okura, Ayako; Hoshide, Satoshi

2016-01-01

Asians have specific characteristics of hypertension (HTN) and its relationship with cardiovascular disease. The morning surge in blood pressure (BP) in Asians is more extended, and the association slope between higher BP and the risk for cardiovascular events is steeper in this population than in whites. Thus, 24-hour BP control including at night and in the morning is especially important for Asian patients with HTN. There are 3 components of "perfect 24-hour BP control": the 24-hour BP level, adequate dipping of nocturnal BP (dipper type), and adequate BP variability such as the morning BP surge. The morning BP-guided approach using home BP monitoring (HBPM) is the first step toward perfect 24-hour BP control. After controlling morning HTN, nocturnal HTN is the second target. We have been developing HBPM that can measure nocturnal BP. First, we developed a semiautomatic HBPM device with the function of automatic fixed-interval BP measurement during sleep. In the J-HOP (Japan Morning Surge Home Blood Pressure) study, the largest nationwide home BP cohort, we successfully measured nocturnal home BP using this device with data memory, 3 times during sleep (2, 3, and 4 am), and found that nocturnal home BP is significantly correlated with organ damage independently of office and morning BP values. The second advance was the development of trigger nocturnal BP (TNP) monitoring with an added trigger function that initiates BP measurements when oxygen desaturation falls below a variable threshold continuously monitored by pulse oximetry. TNP can detect the specific nocturnal BP surges triggered by hypoxic episodes in patients with sleep apnea syndrome. We also added the lowest heart rate-trigger function to TNP to detect the "basal nocturnal BP," which is determined by the circulating volume and structural cardiovascular system without any increase in sympathetic tonus. This double TNP is a novel concept for evaluating the pathogenic pressor mechanism of nocturnal BP. These data are now collected using an information and communication technology (ICT)-based monitoring system. The BP variability includes different time-phase variability from the shortest beat-by-beat, positional, diurnal, day-by-day, visit-to-visit, seasonal, and the longest yearly changes. The synergistic resonance of each type of BP variability would produce great dynamic BP surges, which trigger cardiovascular events. Thus, in the future, the management of HTN based on the simultaneous assessment of the resonance of all of the BP variability phenotypes using a wearable "surge" BP monitoring device with an ICT-based data analysis system will contribute to the ultimate individualized medication for cardiovascular disease. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Extremely cold events and sudden air temperature drops during winter season in the Czech Republic

NASA Astrophysics Data System (ADS)

Crhová, Lenka; Valeriánová, Anna; Holtanová, Eva; Müller, Miloslav; Kašpar, Marek; Stříž, Martin

2014-05-01

Today a great attention is turned to analysis of extreme weather events and frequency of their occurrence under changing climate. In most cases, these studies are focused on extremely warm events in summer season. However, extremely low values of air temperature during winter can have serious impacts on many sectors as well (e.g. power engineering, transportation, industry, agriculture, human health). Therefore, in present contribution we focus on extremely and abnormally cold air temperature events in winter season in the Czech Republic. Besides the seasonal extremes of minimum air temperature determined from station data, the standardized data with removed annual cycle are used as well. Distribution of extremely cold events over the season and the temporal evolution of frequency of occurrence during the period 1961-2010 are analyzed. Furthermore, the connection of cold events with extreme sudden temperature drops is studied. The extreme air temperature events and events of extreme sudden temperature drop are assessed using the Weather Extremity Index, which evaluates the extremity (based on return periods) and spatial extent of the meteorological extreme event of interest. The generalized extreme value distribution parameters are used to estimate return periods of daily temperature values. The work has been supported by the grant P209/11/1990 funded by the Czech Science Foundation.

Hormonal control of cold stress responses in plants.

PubMed

Eremina, Marina; Rozhon, Wilfried; Poppenberger, Brigitte

2016-02-01

Cold stress responses in plants are highly sophisticated events that alter the biochemical composition of cells for protection from damage caused by low temperatures. In addition, cold stress has a profound impact on plant morphologies, causing growth repression and reduced yields. Complex signalling cascades are utilised to induce changes in cold-responsive gene expression that enable plants to withstand chilling or even freezing temperatures. These cascades are governed by the activity of plant hormones, and recent research has provided a better understanding of how cold stress responses are integrated with developmental pathways that modulate growth and initiate other events that increase cold tolerance. Information on the hormonal control of cold stress signalling is summarised to highlight the significant progress that has been made and indicate gaps that still exist in our understanding.

The colonization history of British water vole (Arvicola amphibius (Linnaeus, 1758)): origins and development of the Celtic fringe

PubMed Central

Brace, Selina; Ruddy, Mark; Miller, Rebecca; Schreve, Danielle C.; Stewart, John R.; Barnes, Ian

2016-01-01

The terminal Pleistocene and Early Holocene, a period from 15 000 to 18 000 Before Present (BP), was critical in establishing the current Holarctic fauna, with temperate-climate species largely replacing cold-adapted ones at mid-latitudes. However, the timing and nature of this process remain unclear for many taxa, a point that impacts on current and future management strategies. Here, we use an ancient DNA dataset to test more directly postglacial histories of the water vole (Arvicola amphibius, formerly A. terrestris), a species that is both a conservation priority and a pest in different parts of its range. We specifically examine colonization of Britain, where a complex genetic structure can be observed today. Although we focus on population history at the limits of the species' range, the inclusion of additional European samples allows insights into European postglacial colonization events and provides a molecular perspective on water vole taxonomy. PMID:27122559

The colonization history of British water vole (Arvicola amphibius (Linnaeus, 1758)): origins and development of the Celtic fringe.

PubMed

Brace, Selina; Ruddy, Mark; Miller, Rebecca; Schreve, Danielle C; Stewart, John R; Barnes, Ian

2016-04-27

The terminal Pleistocene and Early Holocene, a period from 15 000 to 18 000 Before Present (BP), was critical in establishing the current Holarctic fauna, with temperate-climate species largely replacing cold-adapted ones at mid-latitudes. However, the timing and nature of this process remain unclear for many taxa, a point that impacts on current and future management strategies. Here, we use an ancient DNA dataset to test more directly postglacial histories of the water vole (Arvicola amphibius, formerly A terrestris), a species that is both a conservation priority and a pest in different parts of its range. We specifically examine colonization of Britain, where a complex genetic structure can be observed today. Although we focus on population history at the limits of the species' range, the inclusion of additional European samples allows insights into European postglacial colonization events and provides a molecular perspective on water vole taxonomy. © 2016 The Author(s).

Late glacial and Early Holocene climatic conditions along the margin of the Greenland Ice Sheet, registered by glacial extents in Milne Land, east Greenland

NASA Astrophysics Data System (ADS)

Levy, L.; Kelly, M. A.; Lowell, T. V.

2010-12-01

Determining the mechanisms that caused past abrupt climate changes is important for understanding today’s rapidly warming climate and, in particular, whether we may be faced with abrupt climate change in the future. Scientists, policy makers and the public are concerned about ongoing warming because it is sending our climate into unprecedented territory at a rapid pace. The Younger Dryas cold event (~12,850-11,650 cal yr B.P.) was an abrupt climate event that occurred during the last transition from glacial to interglacial conditions. Due to its abrupt nature and the magnitude of temperature change that occurred, the Younger Dryas has been the focus of extensive research, however, the mechanisms that caused this cold event are still not well understood. Wide belts (up to 5 km) of moraines, known as the Milne Land stade moraines, are present in the Scoresby Sund region of central east Greenland. Previous work in the region using a combination of equilibrium line altitudes, surface exposure dating of moraines, and relative sea level changes indicates that mountain glacier advances during Younger Dryas time represent only moderate summer temperature cooling (~3-4C colder than at present). In contrast, Greenland ice cores, which register mean annual temperatures, indicate that Younger Dryas temperatures over the ice sheet were ~15C colder than at present. This mismatch between the two nearby paleoclimate records is interpreted to result from strong seasonality (very cold winters and only moderately cold summers) during Younger Dryas time. We are examining seasonality during Younger Dryas time by developing records of summer temperatures from local glaciers in Milne Land (71.0°N, 25.6°W). These mountain glaciers are located adjacent to the Greenland Ice Sheet, less than 50 km from the location of Renland Ice core and only ~250 km from the locations of the GISP2 and GRIP cores. We present new 10Be ages of local glacial extents in Milne Land. Ages range from 11,880 yr to 10,410 yr, indicating that glacial advances occurred during the late Younger Dryas and early Holocene time. The ELA depression of 3-4°C associated with these advances indicates strong seasonality during this time period. These new ages do not show an influence of 10Be inherited from prior periods of exposure, an issue that has hindered applications of 10Be dating in the region in the past. Thus, these ages demonstrate clear evidence for advances of late glacial and early Holocene cooling that must have also influenced the margin of the Greenland Ice Sheet.

Inferring LGM sedimentary and climatic changes in the southern Eastern Alps foreland through the analysis of a 14C ages database (Brenta megafan, Italy)

NASA Astrophysics Data System (ADS)

Rossato, Sandro; Mozzi, Paolo

2016-09-01

The analysis of a database of radiocarbon ages is proposed as a tool for investigating major glaciofluvial systems of the Last Glacial Maximum (LGM) in the Alpine foreland, and their relations with glacier dynamics and climatic fluctuations. Our research concerns the Brenta megafan (NE Italy), where 110 radiocarbon dates integrate a robust regional stratigraphic and palaeoclimatic framework. Age-depth models allowed us to calculate sedimentation rates, while the time distribution of peat layers, which recurrently formed in this region during the LGM, were estimated through meta-analysis. The reliability of statistical results was carefully evaluated using Pearson and Spearman coefficients. Sedimentation rates in the Brenta megafan markedly fluctuated during LGM: ≈1.8 m/ka between 40 and 26.7 ka cal BP; ≈3 m/ka between 26.7 and 23.8 ka cal BP and ≈1.4 m/ka from 23.8 to 17.5 ka cal BP, when the distributary system deactivated due to fan-head trenching. This is evidence that sediment input and routing in the glaciofluvial distributary system was particularly efficient during the central part of LGM, when glaciers were stable at their outermost position. Meta-analysis indicates an increase in peat formation in correspondence with global (Heinrich Event 3 and/or the Greenland Interstadial 5.1 and 4 for the 30.5, 29.6 and 28.8 ka cal BP peaks) and regional (23.5 ka cal BP) wet events. Other peaks at 22.2, 21.8, 20.2 and 19 ka cal BP correlate with fluctuations of south-eastern Alpine glaciers. Significant peat formation continued until ≈18 ka cal BP, when the last peak occurred. A marked decrease in peat formation is recorded concomitantly with the onset of Heinrich Event 2 (i.e. the 26 ka cal BP trough). The good correspondence of sedimentary events in the Brenta glaciofluvial system with the dynamics of glaciers and glaciofluvial and lacustrine systems in the southern Eastern Alps suggests a common climatic forcing on the whole region during the LGM. Peat layer formation in the floodplain fens increased significantly in correspondence with glacier withdrawals and/or wetter climatic episodes, constituting a good proxy for climatic fluctuations during glacial periods. It also allows correlations across different continental environments and regions in the northern hemisphere.

Direct Binding to Replication Protein A (RPA)-coated Single-stranded DNA Allows Recruitment of the ATR Activator TopBP1 to Sites of DNA Damage*

PubMed Central

Acevedo, Julyana; Yan, Shan; Michael, W. Matthew

2016-01-01

A critical event for the ability of cells to tolerate DNA damage and replication stress is activation of the ATR kinase. ATR activation is dependent on the BRCT (BRCA1 C terminus) repeat-containing protein TopBP1. Previous work has shown that recruitment of TopBP1 to sites of DNA damage and stalled replication forks is necessary for downstream events in ATR activation; however, the mechanism for this recruitment was not known. Here, we use protein binding assays and functional studies in Xenopus egg extracts to show that TopBP1 makes a direct interaction, via its BRCT2 domain, with RPA-coated single-stranded DNA. We identify a point mutant that abrogates this interaction and show that this mutant fails to accumulate at sites of DNA damage and that the mutant cannot activate ATR. These data thus supply a mechanism for how the critical ATR activator, TopBP1, senses DNA damage and stalled replication forks to initiate assembly of checkpoint signaling complexes. PMID:27129245

Rethinking Little Rock: The Cold War Politics of School Integration in the United States

ERIC Educational Resources Information Center

Dejong-Lambert, William

2007-01-01

Though the impact of the cold war on the civil rights movement continued long after the desegregation crisis in Little Rock, the timing of the events in Arkansas, particularly the events at Central High School, constituted a unique moment in the history of the cold war. Up until the fall of 1957, the Soviet Union had been perceived as less…

Intermittent blood pressure control: potential consequences for outcome.

PubMed

Leenen, F H

1999-05-01

Although both blood pressure (BP) and left ventricular (LV) mass at initial evaluation predict future cardiovascular risk, the actual BP and LV mass achieved over years of treatment more clearly relate to cardiovascular event rates. Intermittent compliance or noncompliance is the major reason for uncontrolled hypertension and presumably persistent LV hypertrophy. In general, drugs with rapid onset and short duration of action are not desirable because this profile may lead to large variations in BP lowering effect during actual drug intake and rapid disappearance of the antihypertensive effect with missed doses. In addition, intermittent compliance per se introduces the potential for adverse events. For drugs requiring several dose-titrations (e.g., alpha1-blockers), restarting at full doses may lead to excessive drug action and symptomatic hypotension. For other drugs (e.g., short acting beta-blockers or clonidine-like drugs), sudden discontinuation with intermittent compliance may lead to rebound-enhanced sympathetic responsiveness after one to two days, resulting not only in side effects, but also in adverse events, particularly in patients with (silent) coronary artery disease. The rapid onset, short acting dihydropyridines cause intermittent BP control at each dosing, particularly at higher doses. This intermittent control of BP is even more apparent at dosing intervals that are long relative to the duration of action. Thus, sympathetic activation and potential for adverse events can be anticipated at each dosing unless these drugs are being taken frequently at relatively low doses. For diuretics, angiotensin-converting enzyme inhibitors and angiotensin I receptor blockers, no adverse effects have been identified with intermittent compliance. Intermittent BP control is, in general, not an appropriate approach to the management of hypertension and introduces additional risks depending on the type of antihypertensive drug. In contrast, drugs with slow onset and long duration of action provide a more consistent effect during actual drug intake and a more persistent effect during short periods of noncompliance.

Time-to-onset and -resolution of adverse events before/after atomoxetine discontinuation in adult patients with ADHD.

PubMed

Upadhyaya, Himanshu; Tanaka, Yoko; Lipsius, Sarah; Kryzhanovskaya, Ludmila A; Lane, Jeannine R; Escobar, Rodrigo; Trzepacz, Paula T; Allen, Albert J

2015-01-01

Adults with attention-deficit/hyperactivity disorder treated with atomoxetine were examined for time-to-onset and -resolution of common treatment-emergent adverse events (TEAEs) and male sexual dysfunction, and for changes in blood pressure (BP) and heart rate (HR) upon atomoxetine discontinuation. 12-week open-label atomoxetine (40-100 mg/day) was followed by 12-week double-blind maintenance treatment (atomoxetine 80 or 100 mg/day). Responders were then randomized to atomoxetine (n = 266) or placebo (n = 258) for 25-week randomized withdrawal. Examined were (1) median time-to-onset and -resolution of TEAEs during atomoxetine treatment, and (2) within group, visitwise mean changes for sitting HR, systolic BP, and diastolic BP for the postrandomization placebo group. Common adverse events (AEs) appeared early, within week 1 of atomoxetine treatment. Some AEs resolve relatively rapidly, whereas others have a more lingering course of resolution (including male sexual side effects); median resolution times were 3 - 53 days. BP and HR increases during atomoxetine treatment returned to baseline upon atomoxetine discontinuation. Atomoxetine is associated with common AEs, with 3- to 53-day median resolution times. ClincialTrials.gov - NCT00700427.

Heat export from the tropics drives mid to late Holocene palaeoceanographic changes offshore southern Australia

NASA Astrophysics Data System (ADS)

Perner, Kerstin; Moros, Matthias; De Deckker, Patrick; Blanz, Thomas; Wacker, Lukas; Telford, Richard; Siegel, Herbert; Schneider, Ralph; Jansen, Eystein

2018-01-01

The Leeuwin Current (LC), an eastern boundary current, transports tropical waters from the Indo-Pacific Warm Pool (IPWP) towards southern latitudes and modulates oceanic conditions offshore southern Australia. New, high-resolution planktic foraminifer assemblage data and alkenone-derived sea surface temperatures (SST) provide an in-depth view on LC variability and mechanisms driving the current's properties during the mid to late Holocene (last c. 7.4 ka BP). Our marine reconstructions highlight a longer-term mid to late Holocene reduction of tropical heat export from the IPWP area into the LC. Mid Holocene (c. 7.4 to 3.5 ka BP) occurrence of high SSTs (>19.5 °C), tropical planktic foraminifera and a well-stratified water column document an enhanced heat export from the tropics. From c. 3.5 ka BP onwards, a weaker LC and a notably reduced tropical heat export cause oceanic cooling offshore southern Australia. The observed mid to late Holocene trends likely result from large-scale changes in the IPWP's heat storage linked to the El Niño-Southern Oscillation (ENSO) phenomenon. We propose that a strong and warm LC occurs in response to a La Niña-like state of ENSO during the mid Holocene. The late Holocene LC cooling, however, results from a shift towards an El Niño-like state and a more variable ENSO system that causes cooling of the IPWP. Superimposed on these longer-term trends we find evidence of distinct late Holocene millennial-scale phases of enhanced El Niño/La Niña development, which appear synchronous with northern hemispheric climatic variability. Phases of dominant El Niño-like states occur parallel to North Atlantic cold phases: the '2800 years BP cooling event', the 'Dark Ages' and the 'Little Ice Age', whereas the 'Roman Warm Period' and the 'Medieval Climate Anomaly' parallel periods of a predominant La Niña-like state. Our findings provide further evidence of coherent interhemispheric climatic and oceanic conditions during the mid to late Holocene, suggesting ENSO as a potential mediator.

Lateglacial vegetation dynamics in the eastern Baltic region between 14,500 and 11,400 cal yr BP: A complete record since the Bølling (GI-1e) to the Holocene

NASA Astrophysics Data System (ADS)

Veski, Siim; Amon, Leeli; Heinsalu, Atko; Reitalu, Triin; Saarse, Leili; Stivrins, Normunds; Vassiljev, Jüri

2012-04-01

This paper discusses a complete record of vegetation history since the Bølling (GI-1e) warming (14,500 cal yr BP) up to the Holocene in Latvia. To date, this is the only complete record of such age in the eastern Baltic area and the northernmost area for which Bølling records are present. Combining pollen evidence, pollen accumulation rates (PAR) and plant macrofossil data, we assess the local and regional vegetation development, and we attempt to separate the true Lateglacial vegetation signal by removing the obviously redeposited thermophilous pollen; however, we remove not only their signal, we discuss the possibilities of separating the redeposition signal of the so-called "local Lateglacial trees", pine and birch, by looking at their corrosion and degradation. The results show that the Bølling warming in the eastern Baltic area was a treeless tundra community consisting of the shrubs Betula nana, Dryas octopetala and Salix polaris. The Older Dryas cold spell is clearly recognised as a decline in the total concentration of plant macrofossils and PARs at between 14,200 and 13,500 cal yr BP. At 13,460 cal yr BP, the B. nana macrofossils disappear, and tree birch (Betula sect. Albae) appears, marking the start of tree birch forest. The presence of pine forest is confirmed by a variety of macrofossils, including bark, wood, needles and seeds, since 13,400 cal yr BP, at the same time at which pine stomata are found. The first identified pine stomata finds are associated with a Pinus PAR over 3000 grains cm-2 yr-1 and pine macrofossil finds with a Pinus PAR over 4000 grains cm-2 yr-1. During the warmest period of the GI-1a (Allerød) at 13,000-12,700 cal yr BP, a pine forest with deciduous trees (birch -Betula pendula and aspen -Populus tremula) developed in the study area. The Younger Dryas (GS-1) cooling strongly affected the floral composition in eastern Latvia. The PAR of the tree taxa declined abruptly from a maximum value at 12,700 to below 1000 grains cm-2 yr-1 at 12,600 cal yr BP. The response time for the pine forest to collapse was 100 years according to the PAR data. Pine macrofossils disappear simultaneously with the pollen signal at 12,600 cal yr BP, yet occasional Pinus stomata are recorded throughout the Younger Dryas (GS-1). The landscape was treeless shrub tundra again, with D. octopetala, S. polaris, B. nana and Juniperus present. Picea is introduced in the region within the cold Younger Dryas and is represented by stomata (12,400-12,200 cal yr BP), needles, seeds and wood (since 12,050 cal yr BP up to the Holocene). The Pleistocene/Holocene boundary at 11,650 cal yr BP is marked by changes both in vegetation composition and sediment type. The organic rich gyttja accumulated instead of silts and clays, and the start of the Holocene warm period permitted forest re-expansion in eastern Latvia.

The structure and energetics of midlatitude disturbances accompanying cold-air outbreaks over East Asia

NASA Technical Reports Server (NTRS)

Lau, N.-C.; Lau, K.-M.

1984-01-01

The evolution of extratropical transient waves as they propagate eastward from the Eurasian land mass toward the Pacific during selected cold surge events in the winter Monsoon Experiment (MONEX) is studied. The outstanding cold surge episodes during MONEX are first identified, and the salient synoptic features related to these events are described using composite streamline charts. The structure of rapidly varying disturbances accompanying the cold surges and the associated energetics are examined, and the behavior of those fluctuations over relatively longer time scales is addressed.

Indian Monsoon Rainfall Variability During the Common Era: Implications on the Ancient Civilization

NASA Astrophysics Data System (ADS)

Pothuri, D.

2017-12-01

Indian monsoon rainfall variability was reconstructed during last two millennia by using the δ18Ow from a sediment core in the Krishna-Godavari Basin. Higher δ18Ow values during Dark Age Cold Period (DACP) (1550 to 1250 years BP) and Little Ice Age (LIA) (700 to 200 years BP) represent less Indian monsoon rainfall. Whereas during Medieval Warm Period (MWP) (1200 to 800 years BP) and major portion of Roman Warm Period (RWP) 2000 to 1550 years BP) document more rainfall in the Indian subcontinent as evident from lower δ18Ow values. A significant correlation exist between the Bay of Bengal (BoB) sea surface temperature (SST) and Indian monsoon proxy (i.e. δ18Ow), which suggests that; (i) the forcing mechanism of the Indian monsoon rainfall variability during last two millennia was controlled by the thermal contrast between the Indian Ocean and Asian Land Mass, and (ii) the evaporation processes in the BoB and associated SST are strongly coupled with the Indian Monsoon variability over the last two millennia.

Late Holocene monsoon climate as evidenced by proxy records from a lacustrine sediment sequence in western Guangdong, South China

NASA Astrophysics Data System (ADS)

Zhong, Wei; Cao, jiayuan; Xue, Jibin; Ouyang, Jun; Tang, Xiaohong; Yin, Huanling; Liao, Congyun; Long, Kun

2014-02-01

The study of a 300-cm-thick exposed lacustrine sediment section in the Hedong village in Zhaoqing area which is located in sub-tropical west Guangdong Province in South China, demonstrates that the lacustrine sedimentary sequence possibly contains evidence for exploring variation of Asian monsoon climate. Multi-proxy records, including the humification intensity, total organic carbon, and grain size fractions, reveal a general trend towards dry and cold conditions in the late Holocene that this is because of a decrease in solar insolation on an orbital scale. Three intensified Asian summer monsoon (ASM) intervals (˜3300-3000 cal yr BP, ˜2600-1600 cal yr BP, and ˜900-600 cal yr BP), and three weakened ASM intervals (˜4000-3300 cal yr BP, ˜3000-2600 cal yr BP, and ˜1600-900 cal yr BP) are identified. Our humification record (HDcal) shows a good correlation on multi-centennial scale with the tree ring Δ14C record, a proxy of solar activity. A spectral analysis of HDcal reveals four significant cycles, i.e., ˜1250 yr, 300 yr, 110 yr, and 70 yr, and most of these cycles are related to the solar activity. Our findings indicate that solar output and oceanic-atmospheric circulation probably have influenced the late Holocene climate variability in the study region.

Influence of a high-intensity interval training session on peripheral and central blood pressure at rest and during stress testing in healthy individuals.

PubMed

Ketelhut, Sascha; Milatz, Florian; Heise, Walter; Ketelhut, Reinhard G

2016-09-01

Regular physical activity is known to reduce arterial pressure (BP). In a previous investigation, we could prove that even a single bout of moderate-intensity continuous exercise (MICE) causes a prolonged reduction in BP. Whether high-intensity interval training (HIIT) has a favourable influence on BP, and therefore may be followed subjects and methods by a prolonged BP reduction, should be examined on the basis of blood pressure response after exercise and during a subsequent stress test. In 39 healthy men (aged 34 ± 8 years, BMI 24 ± 2), peripheral and central BP were measured noninvasively at rest and at the end of a 2-min cold pressor test (CPT) using a Mobil-O-Graph (24 PWA monitor, IEM). Following HIIT (6 x 1 min at 98% of the previously determined maximum wattage, 4-min rest between intervals) BP was measured again throughout 60 min of rest and thereafter during a CPT. The results were compared with those obtained before HIIT. Similar to MICE, peripheral and central BPs were significantly (p < 0.05) lower 45 min after HIIT. When analysing peripheral BP during a CPT before and after exercise, significantly lower systolic (p < 0.001) and diastolic (p = 0.008) pressures were established after HIIT. This was true for systolic (p = 0.002) and diastolic (p = 0.006) central BP as well. Although there were no more significant differences between pressures at rest before and 60 min after exercise, the increase in peripheral systolic pressure due to CPT was significantly slower after HIIT (p = 0.019) when compared with BP during CPT before exercise. This was true for central systolic BP as well (p = 0.017). HIIT leads to a BP reduction, which can still be detected up to 45 min after completion of the training. Even 60 min after exercise, pressures during a CPT showed a reduced augmentation, indicating an attenuated hemodynamic response to stress testing after HIIT.

Dynamical Influence and Operational Impacts of an Extreme Mediterranean Cold Surge

DTIC Science & Technology

2013-06-01

over 45 cm of snowfall in Souda Bay, Crete, which significantly impacted operations at Naval Support Activity Souda Bay. The extratropical wave...cold surge event and its dependence on the upstream synoptic scale events. 14. SUBJECT TERMS Extratropical Cyclone, Souda Bay...Activity Souda Bay. The extratropical wave associated with the cold surge could be classified as a classic life-cycle 1 wave break. The wave-breaking

A chironomid-based record of temperature variability during the past 4000 years in northern China and its possible societal implications

NASA Astrophysics Data System (ADS)

Wang, Haipeng; Chen, Jianhui; Zhang, Shengda; Zhang, David D.; Wang, Zongli; Xu, Qinghai; Chen, Shengqian; Wang, Shijin; Kang, Shichang; Chen, Fahu

2018-03-01

Long-term, high-resolution temperature records which combine an unambiguous proxy and precise dating are rare in China. In addition, the societal implications of past temperature change on a regional scale have not been sufficiently assessed. Here, based on the modern relationship between chironomids and temperature, we use fossil chironomid assemblages in a precisely dated sediment core from Gonghai Lake to explore temperature variability during the past 4000 years in northern China. Subsequently, we address the possible regional societal implications of temperature change through a statistical analysis of the occurrence of wars. Our results show the following. (1) The mean annual temperature (TANN) was relatively high during 4000-2700 cal yr BP, decreased gradually during 2700-1270 cal yr BP and then fluctuated during the last 1270 years. (2) A cold event in the Period of Disunity, the Sui-Tang Warm Period (STWP), the Medieval Warm Period (MWP) and the Little Ice Age (LIA) can all be recognized in the paleotemperature record, as well as in many other temperature reconstructions in China. This suggests that our chironomid-inferred temperature record for the Gonghai Lake region is representative. (3) Local wars in Shanxi Province, documented in the historical literature during the past 2700 years, are statistically significantly correlated with changes in temperature, and the relationship is a good example of the potential societal implications of temperature change on a regional scale.

Stable-Isotope Perspectives on Holocene Environmental Change at Archaeological Sites in the Middle Tanana Valley, Interior Alaska

NASA Astrophysics Data System (ADS)

Johnson, W. C.; Gaines, E. P.

2010-12-01

Summer of 2009, Colorado State University Center for Environmental Management of Military Lands conducted test excavations of 29 prehistoric archaeological sites situated on a loess-mantled morainal ridge complex within the Jarvis Creek valley of the Tanana River system at Fort Wainwright in Interior Alaska. Initial loess deposition on the moraines began about 13,000 cal yr BP, with subsequent long-term, nomadic occupation of the area occurring from 9,500 to 1,060 cal yr BP. An array of data were extracted from bulk-sediment samples and used to assess past environmental conditions. Parameters and approaches used to generate these data included stable carbon isotope ratios, magnetic susceptibility, biogenic opal analysis, detrital charcoal content, quantitative color (L*a*b), and particle-size distribution. Stable carbon isotope trends, in combination with the other environmental proxy data, document major environmental changes. Data from the glacial till-loess transition and lower silt mantle indicate that the area was cold and slightly mesic, and dominated by treeless C3-dominated grassland immediately after the terminal Pleistocene glacial retreat (~12,700 cal yr BP). A dearth of particulate charcoal and charred phytoliths from sediments of this period suggests a minor role for fire, e.g., only localized, small fires. Cold, treeless environmental conditions continued throughout the Early Holocene (~12,000-7,000 cal yr BP), though it was more mesic than earlier. Middle Holocene (~7000-5000 cal yr BP) data display a shift in C3 grass species (increased δ13C values), the appearance of a shrub component to the plant community, significant surface stability, and more widespread fire occurrence. Picea glauca (white spruce) and Alnus sp. (alder) appear in the later parts of the Middle Holocene, and charcoal concentration increases. The Late Holocene (since ~5,000 cal yr BP) witnessed a decline in P. glauca by about 50%, a tenfold increase in Alnus, and the appearance of Betula sp. (birch). Further increases in isotope values and high frequencies of algal statospores in the surface soil (last ~2500 yrs) indicate that the soil has remained moist throughout most of the growing season due to rain and snowmelt. Also, a 4.5-fold increase in charcoal concentration and increase in charcoal particle size suggest common, local fires in the latter part of the Holocene, the period during which the modern vegetative community was established.

Eukaryotic diversity in premise drinking water using 18S rDNA sequencing: implications for health risks

EPA Science Inventory

The goal of this study was to characterize microbial eukaryotes over a 12 month period, so as to provide insight into the occurrence of potentially important predators and bacterial hosts in hot and cold premise plumbing. Nearly 6,300 partial (600 bp) 18S rRNA gene sequences from...

Evidence for Reverse Causality in the Association Between Blood Pressure and Cardiovascular Risk in Patients With Chronic Kidney Disease

PubMed Central

Herrington, William; Staplin, Natalie; Judge, Parminder K.; Mafham, Marion; Emberson, Jonathan; Haynes, Richard; Wheeler, David C.; Walker, Robert; Tomson, Charlie; Agodoa, Larry; Wiecek, Andrzej; Lewington, Sarah; Reith, Christina A.; Landray, Martin J.

2017-01-01

Among those with moderate-to-advanced chronic kidney disease, the relationship between blood pressure (BP) and cardiovascular disease seems U shaped but is loglinear in apparently healthy adults. The SHARP (Study of Heart and Renal Protection) randomized 9270 patients with chronic kidney disease to ezetimibe/simvastatin versus matching placebo and measured BP at each follow-up visit. Cox regression was used to assess the association between BP and risk of cardiovascular disease among (1) those with a self-reported history of cardiovascular disease and (2) those with no such history and, based on plasma troponin-I concentration, a low probability of subclinical cardiac disease. A total of 8666 participants had a valid baseline BP and troponin-I measurement, and 2188 had at least 1 cardiovascular event during follow-up. After adjustment for relevant confounders, the association between systolic BP and cardiovascular events was U shaped, but among participants without evidence of previous cardiovascular disease, there was a positive loglinear association throughout the range of values studied. Among those with the lowest probability of subclinical cardiac disease, each 10 mm Hg higher systolic BP corresponded to a 27% increased risk of cardiovascular disease (hazard ratio, 1.27; 95% confidence interval, 1.11–1.44). In contrast, the relationship between diastolic BP and cardiovascular risk remained U shaped irrespective of cardiovascular disease history or risk of subclinical disease. In conclusion, the lack of a clear association between systolic BP and cardiovascular risk in this population seems attributable to confounding, suggesting that more intensive systolic BP reduction may be beneficial in such patients. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00125593. PMID:28028192

Recurrence of stroke caused by nocturnal hypoxia-induced blood pressure surge in a young adult male with severe obstructive sleep apnea syndrome.

PubMed

Yoshida, Tetsuro; Kuwabara, Mitsuo; Hoshide, Satoshi; Kario, Kazuomi

2016-03-01

Obstructive sleep apnea syndrome (OSAS) causes resistant hypertension and a hypopnea-related nocturnal blood pressure (BP) surge. This could lead to an increase of not only the nocturnal BP level but also nocturnal BP variability, both of which increase an individual's cardiovascular risk. We recently developed a trigger sleep BP monitoring method that initiates BP measurement when an individual's oxygen desaturation falls below a variable threshold, and we demonstrated that it can detect a BP surge during apnea episodes. We here report the case of a 36-year-old man with severe OSAS who experienced the recurrence of stroke due to nocturnal hypoxia and a nocturnal BP surge measured by this trigger sleep BP monitoring device. A nocturnal BP surge during sleep in OSAS patients could be a strong trigger of cardiovascular events. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Environment and paleoecology of a 12 ka mid-North American Younger Dryas forest chronicled in tree rings

USGS Publications Warehouse

Panyushkina, Irina P.; Leavitt, Steven W.; Thompson, Todd A.; Schneider, Allan F.; Lange, Todd

2008-01-01

Until now, availability of wood from the Younger Dryas abrupt cooling event (YDE) in N. America ca. 12.9 to 11.6 ka has been insufficient to develop high-resolution chronologies for refining our understanding of YDE conditions. Here we present a multi-proxy tree-ring chronology (ring widths, “events” evidenced by microanatomy and macro features, stable isotopes) from a buried black spruce forest in the Great Lakes area (Liverpool East site), spanning 116 yr at ca. 12,000 cal yr BP. During this largely cold and wet period, the proxies convey a coherent and precise forest history including frost events, tilting, drowning and burial in estuarine sands as the Laurentide Ice Sheet deteriorated. In the middle of the period, a short mild interval appears to have launched the final and largest episode of tree recruitment. Ultimately the tops of the trees were sheared off after death, perhaps by wind-driven ice floes, culminating an interval of rising water and sediment deposition around the base of the trees. Although relative influences of the continental ice sheet and local effects from ancestral Lake Michigan are indeterminate, the tree-ring proxies provide important insight into environment and ecology of a N. American YDE boreal forest stand.

Expression of ferritin-like protein in Listeria monocytogenes after cold and freezing stress.

PubMed

Miladi, Hanene; Soukri, Abdelaziz; Bakhrouf, Amina; Ammar, Emna

2012-11-01

The cold shock protein family consists of the transfer of the foodborne pathogen Listeria monocytogenes from 37 to 4 and -20 °C and was characterized by the sharp induction of a low molecular mass protein. This major cold shock protein ferritin-like protein (Flp) has an important role in regulation of various microbial physiological processes. Flp have a molecular mass of about 18 kDa, as observed on SDS-PAGE. The purification procedure including ammonium sulfate fractionation was used. Monospecific polyclonal antibodies raised in rabbits against the purified new Flp immunostained a single 18-kDa Flp band in extracts from different cytoplasmic proteins blotted onto nitrocellulose. A 411-bp cDNA fragment that corresponds to an internal region of an flp gene was obtained by RT-PCR. Our result indicated a surexpression of major cold shock protein and an important increase in flp mRNA amount after a downshift temperature especially at -20 °C.

Predictive Value of Pulse Pressure in Acute Ischemic Stroke for Future Major Vascular Events.

PubMed

Lee, Keon-Joo; Kim, Beom Joon; Han, Moon-Ku; Kim, Joon-Tae; Cho, Ki-Hyun; Shin, Dong-Ick; Yeo, Min-Ju; Cha, Jae-Kwan; Kim, Dae-Hyun; Nah, Hyun-Wook; Kim, Dong-Eog; Ryu, Wi-Sun; Park, Jong-Moo; Kang, Kyusik; Lee, Soo Joo; Oh, Mi-Sun; Yu, Kyung-Ho; Lee, Byung-Chul; Hong, Keun-Sik; Cho, Yong-Jin; Choi, Jay Chol; Sohn, Sung Il; Hong, Jeong-Ho; Park, Tai Hwan; Park, Sang-Soon; Kwon, Jee-Hyun; Kim, Wook-Joo; Lee, Jun; Lee, Ji Sung; Lee, Juneyoung; Gorelick, Philip B; Bae, Hee-Joon

2018-01-01

This study aimed to investigate whether pulse pressure (PP) obtained during the acute stage of ischemic stroke can be used as a predictor for future major vascular events. Using a multicenter prospective stroke registry database, patients who were hospitalized for ischemic stroke within 48 hours of onset were enrolled in this study. We analyzed blood pressure (BP) data measured during the first 3 days from onset. Primary and secondary outcomes were time to a composite of stroke recurrence, myocardial infarction, all-cause death, and time to stroke recurrence, respectively. Of 9840 patients, 4.3% experienced stroke recurrence, 0.2% myocardial infarction, and 7.3% death during a 1-year follow-up period. In Cox proportional hazards models including both linear and quadratic terms of PP, PP had a nonlinear J-shaped relationship with primary (for a quadratic term of PP, P =0.004) and secondary ( P <0.001) outcomes. The overall effects of PP and other BP parameters on primary and secondary outcomes were also significant ( P <0.05). When predictive power of BP parameters was compared using a statistic of -2 log-likelihood differences, PP was a stronger predictor than systolic BP (8.49 versus 5.91; 6.32 versus 4.56), diastolic BP (11.42 versus 11.05; 10.07 versus 4.56), and mean atrial pressure (8.75 versus 5.91; 7.03 versus 4.56) for the primary and secondary outcomes, respectively. Our study shows that PP when measured in the acute period of ischemic stroke has nonlinear J-shaped relationships with major vascular events and stroke recurrence, and may have a stronger predictive power than other commonly used BP parameters. © 2017 American Heart Association, Inc.

Cold Reversal on Kodiak Island, Alaska, Correlated with the European Younger Dryas by Using Variations of Atmospheric C-14 Content

NASA Technical Reports Server (NTRS)

Hajdas, Irka; Bonani, Georges; Boden, Per; Peteet, Dorothy M.; Mann, Daniel H.

1999-01-01

High-resolution AMS (accelerator-mass-spectrometer) radiocarbon dating was performed on late-glacial macrofossils in lake sediments from Kodiak Island, Alaska, and on shells in marine sediments from southwest Sweden. In both records, a dramatic drop in radiocarbon ages equivalent to a rise in the atmospheric C-14 by approximately 70%. coincides with the beginning of the cold period at 11000 yr B.P. (C-14 age). Thus our results show that a close correlation between climatic records around the globe is possible by using a global signature of changes in atmospheric C-14 content.

Organic geochemical investigations of the Dali Lake sediments in northern China: Implications for environment and climate changes of the last deglaciation in the East Asian summer monsoon margin

NASA Astrophysics Data System (ADS)

Fan, Jiawei; Xiao, Jule; Wen, Ruilin; Zhang, Shengrui; Wang, Xu; Cui, Linlin; Yamagata, Hideki

2017-06-01

Millennial-scale environment and climate changes in the East Asian summer monsoon margin during the last deglaciation are reconstructed by systematic studies on the characteristic of sedimentary organic matter from Dali Lake in northern China. Concurrent increases in the TOC and TN concentrations indicate increases in terrestrial organic matter and nutrient inputs to the lake and a development of terrestrial vegetation and phytoplankton productivity related to increases in regional temperature and precipitation. C/N ratios reflect changes in the proportions of terrestrial and aquatic organic matter. Decreases in both δ13Corg and δ15N values indicate increases in the isotopically lighter, terrestrial carbon and nitrogen inputs to the lake, due to increases in surface runoffs; while a sharp decrease in the δ15N value implies a significant weakening in the biological activities of nitrifying and amonifying bacteria, due to abrupt decrease in the water temperature. The geochemical data indicate that regional temperature and precipitation exhibited increasing trends from 15,000 to 12,350 cal yr BP; temperature decreased abruptly at 12,350 cal yr BP and then maintained a low level from 12,350 to 11,400 cal yr BP, precipitation decreased to a relatively low level from 12,350 to 11,400 cal yr BP; and both temperature and precipitation returned to increase after 11,400 cal yr BP. The climate change in the Dali Lake region during the last deglaciation corresponds, within age uncertainties, to the Bølling-Allerød (BA) warm phase and Younger Dryas (YD) cold reversal occurring over northern high latitudes. However, the gradual and mild increasing trends of regional temperature and precipitation during the BA warm period contrasts with the general cooling trend in northern high latitude temperature, implying a dominant influence from increases in the Northern Hemisphere summer insolation; while the slight decreases in regional precipitation relative to the rapid and significant decreases in northern high latitude temperature during the YD cold period may have resulted from local moisture recycling or from an insensitive response of hydrology and ecology to the regional precipitation change.

Holocene sedimentation processes and environmental changes along the Namibian coastline

NASA Astrophysics Data System (ADS)

Schüller, Irka; Belz, Lukas; Wilkes, Heinz; Wehrmann, Achim

2016-04-01

The regional oceanic and atmospheric circulation patterns strongly control environmental conditions in southern Africa. Changes in the system may have significant consequences on climate and related processes. The hyper arid coast of Namibia is mainly influenced by (1) the cold Benguela upwelling, (2) the Benguela current and (3) the Angola current. The Benguela current transports the cool, upwelling water from south to north and interacts with the warm, contrary flowing Angola current at the Angola-Benguela Front (ABF). Today the ABF is located around the Namibian-Angolan border with minor seasonal changes. Therefore, climate and environment at the Namibian coast are affected by the cold water conditions. It is known evidently that the location of the ABF changed during the Holocene over several latitudes and enabled warm water species to expand their range farther south. Several (paleo-) lagoons (coastal salt pans) exist along the Namibian coastline. Most of them are already barred and filled by longshore sediment transport processes. Tidal flooding and active sedimentation processes are restricted to the southernmost lagoons. Two different types of sediments occur. The northern pans contain well sorted, siliciclastic medium sands. Fine-layered alternation refers to changes in mineral composition. The southern pans are dominated by typical tidal sediments with a high amount of benthic fauna (mainly bivalves and gastropods). At Cape Cross the distinct shift between both facies is documented in the cores. Age determinations of core material prove a very fast sediment filling of the distinct lagoons with high sedimentation rates. However, the age of closure differs from lagoon to lagoon. Northern pan sediments are much older (Cape Cross: ~ 5000 a BP) than southern (Sandwich Bay and Conception Bay: 1800 - 300 a BP). Additional information are supported by river clay deposits (~ 36600 a BP) and fossil reed systems (~ 47900 a BP) in Conception Bay and peat deposits at the fossil Kuiseb delta between Walvis Bay and Sandwich Bay (~ 1350 - 750 a BP). The results of our analyses of lagoon and pan sediments as well as the fossil remnants allow the reconstruction of coastal sedimentation processes as well as the associated Holocene environmental changes at the coast and the terrestrial hinterland.

Paleolimnology of Lake Ontario: AN Assessment of Glacial Meltwater Influx

NASA Astrophysics Data System (ADS)

Hladyniuk, R.; Longstaffe, F. J.

2010-12-01

The timing and extent of glacial meltwater outbursts from the Laurentide Ice Sheet (LIS) may provide insight into their potential role in initiating and/or sustaining the Younger Dryas (YD) cooling event. It has been previously proposed that meltwater from the LIS suppressed thermohaline circulation in the Atlantic Ocean, leading to an abrupt change in climate (Broecker et al. 1989). Several pathways for transport of glacial meltwater to the Atlantic Ocean have been suggested in the past, including eastern flow through the St. Lawrence River system and discharge into the Arctic Ocean via a northwestern outlet (Murton et al. 2010). Glacial meltwater contributions to Lake Ontario and its ancient equivalents during the last ~14,000 cal BP have been evaluated using the oxygen-isotope compositions of ostracode shells from three sediment cores in Lake Ontario. Glacial Lake Iroquois (~12,500 cal BP) δ18O values as low as -18‰ suggest significant contribution of glacial meltwater runoff from the LIS. This glacial sediment is characterized by occasional grains of sand and gravel. These ice-rafted particles indicate how far icebergs floated and suggest close proximity to the LIS. Early Lake Ontario sediment (~12,000 cal BP) exhibits thicker laminations, suggestive of increased winter ice cover and perhaps a colder climate, and is characterized by slightly lower δ18O values (-19.5‰). The end of glacial-dominated sedimentation at ~11,800 cal BP is demarcated by a significant increase in lakewater δ18O values (-12.0‰), reflecting mixing between regional precipitation in the watershed and upstream inflow into Lake Ontario. At ~10,800 cal BP, the δ18O value of Lake Ontario decreased to ~-15‰. This change reflects the main Algonquin highstand in Lake Huron, which flooded into Lake Ontario from both the Fenelon Falls and Port Huron outlets at this time. Shortly thereafter, the opening of the North Bay outlet and isostatic rebound at the Port Huron outlet limited discharge from the upper Great Lakes to Lakes Erie and Ontario. From ~10,500 to 7,500 cal BP, closed-basin conditions prevailed in Lake Ontario (Lewis et al. 2010). Extreme evaporation and a dry climate associated with the Holocene Thermal Maximum, beginning at ~8,000 cal BP, led to a further shift to higher δ18O values (-7.0‰). The ostracode record then ends at ~4,000 cal BP, coincident with return of significant drainage from the Upper Great Lakes. Broecker W.S., Kennett J.P., Flower B.P., Teller J.T., Trumbore S., Bonani G., Wolfli W. (1989) Routing of meltwater from the Laurentide Ice Sheet during the Younger Dryas cold episode. Nature 341, 318-321. Lewis C.F.M., Anderson T.W., Cameron G., King J.W., Heil Jr. C.W. (2010) The reduced Lakes Erie and Ontario, a severe response to past drier climate. 53rd Annual International Association for Great Lakes Research-Conference Abstract. Murton J.B., Bateman M.D., Dallimore S.R., Teller J.T., Yang Z. (2010) Identification of Younger Dryas outburst flood path from Lake Agassiz to the Arctic Ocean. Nature Letters 434, 740-743.

Expression analysis and functional characterization of a novel cold-responsive gene CbCOR15a from Capsella bursa-pastoris.

PubMed

Zhou, Mingqi; Wu, Lihua; Liang, Jing; Shen, Chen; Lin, Juan

2012-05-01

The cold-responsive (COR) genes involved in C-repeat binding factor signaling pathway function essentially in cold acclimation of higher plants. A novel COR gene CbCOR15a from shepherd's purse (Capsella bursa-pastoris) was predicted to be a homolog of COR15 in Arabidopsis. The analysis of tissue specific expression pattern as well as characterization of the CbCOR15a promoter revealed that the expression of CbCOR15a was induced by coldness not only in leaves and stem but also in roots. Sequence analysis showed that a 909 bp promoter region of CbCOR15a contained two CRT/DRE elements, two ABRE elements, one auxin-responsive TGA-element and one MeJA-responsive CGTCA-motif. In young seedlings the expression of CbCOR15a could be apparently increased by SA, ABA, MeJA and IAA, and transiently increased by GA(3) accompanied by obvious feedback suppression. According to the altered physiological index values in tobacco under cold treatments, the overexpression of CbCOR15a significantly increased the cold tolerance of transgenic tobacco plants. It can be suggested that CbCOR15a was involved in cold response of Capsella bursa-pastoris associated with SA, ABA, MeJA, IAA and GA(3) regulation and confers enhanced cold acclimation in transgenic plants.

Paleoenvironmental dynamics in South Amazonia, Brazil, during the last 35,000 years inferred from pollen and geochemical records of Lago do Saci

NASA Astrophysics Data System (ADS)

Fontes, D.; Cordeiro, R. C.; Martins, G. S.; Behling, H.; Turcq, B.; Sifeddine, A.; Seoane, J. C. S.; Moreira, L. S.; Rodrigues, R. A.

2017-10-01

Paleoenvironmental changes for the last 35,000 years were reconstructed from palynological, sedimentological and organic geochemical evidence from a well-dated sediment core from Lago do Saci (South Amazonia). Dry climatic conditions occurred between 35,000 and 18,200 cal yr BP as recorded by high frequencies of open savanna taxa and low lake level indicated by Sagittaria and low Total Organic Carbon content. Cold temperatures are indicated by the presence of Podocarpus and Ilex. A sedimentation hiatus observed between 18,200 and 9200 cal yr BP was likely related to dry conditions. The beginning of the Holocene was marked by rainforest expansion and an increase in carbon content that represented high lake levels and warmer and wetter climate conditions. Between 7500 and 5000 cal yr BP, the expansion of open savanna, seasonal forest elements and abundant black carbon suggests a dry phase. After 5000 cal yr BP, rainforest expansion and higher lake levels indicate a return to wetter conditions. A reduction of flooding taxa (Celtis and Mauritia) between 1800 and 1300 cal yr BP, high lake level conditions and maintenance of a forest physiognomy, suggests a decrease of regional precipitation and subsequent reduction of the flooded areas in a still humid climate regime.

Late Quaternary vegetation and climate history of a perennial river canyon in the Rīo Salado basin (22°S) of Northern Chile

USGS Publications Warehouse

Latorre, Claudio; Betancourt, Julio L.; Arroyo, Mary T.K.

2006-01-01

Plant macrofossils from 33 rodent middens sampled at three sites between 2910 and 3150 m elevation in the main canyon of the Rīo Salado, northern Chile, yield a unique record of vegetation and climate over the past 22,000 cal yr BP. Presence of low-elevation Prepuna taxa throughout the record suggests that mean annual temperature never cooled by more than 5°C and may have been near-modern at 16,270 cal yr BP. Displacements in the lower limits of Andean steppe and Puna taxa indicate that mean annual rainfall was twice modern at 17,520-16,270 cal yr BP. This pluvial event coincides with infilling of paleolake Tauca on the Bolivian Altiplano, increased ENSO activity inferred from a marine core near Lima, abrupt deglaciation in southern Chile, and Heinrich Event 1. Moderate to large increases in precipitation also occurred at 11,770-9550 (Central Atacama Pluvial Event), 7330-6720, 3490-2320 and at 800 cal yr BP. Desiccation occurred at 14,180, 8910-8640, and 4865 cal yr BP. Compared to other midden sites in the region, early Holocene desiccation seems to have happened progressively earlier farther south. Emerging trends from the cumulative midden record in the central Atacama agree at millennial timescales with improved paleolake chronologies for the Bolivian Altiplano, implying common forcing through changes in equatorial Pacific sea-surface temperature gradients.

24-Hour Blood Pressure Variability Assessed by Average Real Variability: A Systematic Review and Meta-Analysis.

PubMed

Mena, Luis J; Felix, Vanessa G; Melgarejo, Jesus D; Maestre, Gladys E

2017-10-19

Although 24-hour blood pressure (BP) variability (BPV) is predictive of cardiovascular outcomes independent of absolute BP levels, it is not regularly assessed in clinical practice. One possible limitation to routine BPV assessment is the lack of standardized methods for accurately estimating 24-hour BPV. We conducted a systematic review to assess the predictive power of reported BPV indexes to address appropriate quantification of 24-hour BPV, including the average real variability (ARV) index. Studies chosen for review were those that presented data for 24-hour BPV in adults from meta-analysis, longitudinal or cross-sectional design, and examined BPV in terms of the following issues: (1) methods used to calculate and evaluate ARV; (2) assessment of 24-hour BPV determined using noninvasive ambulatory BP monitoring; (3) multivariate analysis adjusted for covariates, including some measure of BP; (4) association of 24-hour BPV with subclinical organ damage; and (5) the predictive value of 24-hour BPV on target organ damage and rate of cardiovascular events. Of the 19 assessed studies, 17 reported significant associations between high ARV and the presence and progression of subclinical organ damage, as well as the incidence of hard end points, such as cardiovascular events. In all these cases, ARV remained a significant independent predictor ( P <0.05) after adjustment for BP and other clinical factors. In addition, increased ARV in systolic BP was associated with risk of all cardiovascular events (hazard ratio, 1.18; 95% confidence interval, 1.09-1.27). Only 2 cross-sectional studies did not find that high ARV was a significant risk factor. Current evidence suggests that ARV index adds significant prognostic information to 24-hour ambulatory BP monitoring and is a useful approach for studying the clinical value of BPV. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Abrupt Atmospheric Methane Increases Associated With Hudson Strait Heinrich Events

NASA Astrophysics Data System (ADS)

Rhodes, R.; Brook, E.; Chiang, J. C. H.; Blunier, T.; Maselli, O. J.; McConnell, J. R.; Romanini, D.; Severinghaus, J. P.

2015-12-01

The drivers of abrupt climate change during the Last Glacial Period are not well understood. While Dansgaard-Oeschger (DO) cycles are thought to be linked to variations in the strength of the Atlantic Meridional Ocean Circulation (AMOC), it is not clear how or if Heinrich Events—extensive influxes of icebergs into the North Atlantic Ocean that impacted global climate and biogeochemistry—are related. An enduring problem is the difficultly in dating iceberg rafted debris deposits that typically lack foraminifera. Here we present an ultra-high resolution record of methane from the West Antarctic Ice Sheet Divide ice core at unprecedented, continuous temporal resolution from 67.2-9.8 ka BP, which we propose constrains the timing of Heinrich events. Our methane record essentially mirrors Greenland ice core stable isotope variability across D-O events, except during Heinrich stadials 1, 2, 4 and 5. Partway through these stadials only, methane increases abruptly and rapidly, as at the onset of a D-O event but Greenland temperature exhibits no equivalent response. Speleothem records exhibit signatures of drought in the Northern extra-tropics and intensified monsoonal activity over South America at these times. We use a simple heuristic model to propose that cold air temperatures and extensive sea ice in the North, resulting from Heinrich events, caused extreme reorganization of tropical hydroclimate. This involved curtailment of the seasonal northerly migration of tropical rain belts, leading to intensification of rainfall over Southern Hemisphere tropical wetlands, thus allowing production of excess methane relative to a 'normal' Greenland stadial. We note that this mechanism can operate if AMOC is already in a slowed state when a Heinrich event occurs, as paleo-evidence suggests it was. Heinrich events and associated sea ice cover would therefore act to prolong the duration of this AMOC state. Our findings place the big four Heinrich events of Hudson Strait origin firmly within ice core chronologies and suggest that their impacts on AMOC and tropical hydroclimate persisted for 740-1520 yr.

Screening for Hypertension and Lowering Blood Pressure for Prevention of Cardiovascular Disease Events.

PubMed

Viera, Anthony J

2017-07-01

Hypertension affects 1 in 3 American adults. Blood pressure (BP)-lowering therapy reduces the risk of cardiovascular disease. The United States Preventive Services Task Force recommends all adults be screened for hypertension. Most patients whose office BP is elevated should have out-of-office monitoring to confirm the diagnosis. Ambulatory BP monitoring is preferred for out-of-office measurement, but home BP monitoring is a reasonable alternative. Guidelines for treatment are stratified by age (<60 vs >60 years) and include cutoffs for recommended treatment BPs and target BP goals. Quality of hypertension care is improved by incorporating population health management using registries and medication titration. Copyright © 2017 Elsevier Inc. All rights reserved.

Extreme hydrometeorological events in the Peruvian Central Andes during austral summer and their relationship with the large-scale circulation

NASA Astrophysics Data System (ADS)

Sulca, Juan C.

In this Master's dissertation, atmospheric circulation patterns associated with extreme hydrometeorological events in the Mantaro Basin, Peruvian Central Andes, and their teleconnections during the austral summer (December-January-February-March) are addressed. Extreme rainfall events in the Mantaro basin are related to variations of the large-scale circulation as indicated by the changing strength of the Bolivian High-Nordeste Low (BH-NL) system. Dry (wet) spells are associated with a weakening (strengthening) of the BH-NL system and reduced (enhanced) influx of moist air from the lowlands to the east due to strengthened westerly (easterly) wind anomalies at mid- and upper-tropospheric levels. At the same time extreme rainfall events of the opposite sign occur over northeastern Brazil (NEB) due to enhanced (inhibited) convective activity in conjunction with a strengthened (weakened) Nordeste Low. Cold episodes in the Mantaro Basin are grouped in three types: weak, strong and extraordinary cold episodes. Weak and strong cold episodes in the MB are mainly associated with a weakening of the BH-NL system due to tropical-extratropical interactions. Both types of cold episodes are associated with westerly wind anomalies at mid- and upper-tropospheric levels aloft the Peruvian Central Andes, which inhibit the influx of humid air masses from the lowlands to the east and hence limit the potential for development of convective cloud cover. The resulting clear sky conditions cause nighttime temperatures to drop, leading to cold extremes below the 10-percentile. Extraordinary cold episodes in the MB are associated with cold and dry polar air advection at all tropospheric levels toward the central Peruvian Andes. Therefore, weak and strong cold episodes in the MB appear to be caused by radiative cooling associated with reduced cloudiness, rather than cold air advection, while the latter plays an important role for extraordinary cold episodes only.

Quartz grains reveal sedimentary palaeoenvironment and past storm events: A case study from eastern Baltic

NASA Astrophysics Data System (ADS)

Kalińska-Nartiša, Edyta; Stivrins, Normunds; Grudzinska, Ieva

2018-01-01

Sediment record collected from the coastal lake serves as a powerful tool for reconstructing changes in palaeoenvironment and understanding the potential signals of past storminess. In this study, we use several proxies from sediment of the Holocene Thermal Maximum at coastal Lake Lilaste, Latvia. We focus on surface texture of quartz grains from the mineral inorganic fraction as indicators of depositional environments. We then use this as a proxy for potential storm transport and combine with information on granulometry, diatom stratigraphy and chronology to answer the question whether flux of quartz grains in the lake originated from the sea or from the land. Analyses in a binocular and scanning electron microscope reveal that most of the investigated quartz grains originate from dwelling in the seawater and wave action in the nearshore zone. Grains representing very energetic subaqueous environment similar to storm events are also present. Terrestrial record is of minor significance and visible through occurrence of aeolian quartz grains. During drier and colder conditions, an influx of sand with aeolian imprint was delivered to the lake between 8500 and 7800 cal yr BP. Marine and terrestrial conditions alternated between 7800 and 6000 cal yr BP. Storm-induced grains were likely deposited three times: at 7300 cal yr BP, 6600-6400 cal yr BP, and 6200-6000 cal yr BP. Overall stable marine environmental conditions prevailed between 6000 and 4000 cal yr BP except of the last portion of terrestrial-induced sediment at 4100 cal yr BP.

Elevated blood pressure at the first measurement predicts cardiovascular disease independently from the subsequent second reading in men, but not in women.

PubMed

Makita, Shinji; Tanaka, Fumitaka; Onoda, Toshiyuki; Ohsawa, Masaki; Tanno, Kozo; Omama, Shinichi; Yoshida, Yuki; Ishibashi, Yasuhiro; Segawa, Toshie; Takahashi, Tomohiro; Satoh, Kenyu; Itai, Kazuyoshi; Sakata, Kiyomi; Ohta, Mutsuko; Kuribayashi, Toru; Ogasawara, Kuniaki; Ogawa, Akira; Okayama, Akira; Nakamura, Motoyuki

2015-01-01

There have been no investigations concerning the association of each blood pressure (BP) reading with future cardiovascular disease (CVD) when multiple measurements are taken on one occasion. This community-based, prospective cohort study (n = 23 344, mean age = 62.4 years) investigated the associations between the BP obtained from the first and second of two consecutive measurements on one occasion and future cardiovascular events in men and women. During the mean follow-up of 5.5 years, 624 CVD events were identified. On the Cox regression analysis of age- and BP-adjusted models, the increased CVD risk of a hypertensive first measurement (systolic BP ≥ 140 mmHg) was independent from the second measurement in men. Even in subjects without a hypertensive second measurement, the CVD risk of the hypertensive first measurement was increased in men. In women, despite a hypertensive first measurement, subjects with a systolic BP < 130 mmHg on the second measurement showed a significantly reduced risk for CVD compared with subjects who retained a hypertensive level during the two measurements. An elevated BP on the first measurement should not be disregarded for CVD risk estimation in men, even if the second BP moves to the normal range. In women, elevated BP on the first measurement may have relatively less meaning for CVD prediction if the second BP shifts to a normal range.

Aliskiren alone or with other antihypertensives in the elderly with borderline and stage 1 hypertension: the APOLLO trial.

PubMed

Teo, Koon K; Pfeffer, Marc; Mancia, Giuseppe; O'Donnell, Martin; Dagenais, Gilles; Diaz, Rafael; Dans, Antonio; Liu, Lisheng; Bosch, Jackie; Joseph, Philip; Copland, Ingrid; Jung, Hyejung; Pogue, Janice; Yusuf, Salim

2014-07-01

We studied the unclear question whether blood pressure (BP) lowering reduces cardiovascular disease (CVD) in elderly individuals with systolic BP <160 mm Hg. We initiated a randomized placebo-controlled stratified 2 × 2 factorial clinical trial evaluating the effects of BP lowering in 11 000 elderly individuals with systolic blood pressure (SBP) between 130 and 159 mm Hg, for 5 years. Following 5-week active run-in, participants were randomized to aliskiren (300 mg) or placebo, and to an additional antihypertensive [hydrochlorothiazide (25 mg) or amlodipine (5 mg)], or their respective placeboes. Study was terminated by sponsor after 1759 subjects (age 72.1 ± 5.2 years, 88% receiving at least one antihypertensive) were randomized and followed for 0.6 year. Study drugs were well tolerated with few serious adverse events during run-in and after randomization, with no significant differences between treatment groups. By design, three levels of BP reductions were achieved, adjusted mean BP reductions of 3.5/1.7 mm Hg (P < 0.001) by aliskiren, 6.8/3.3 mm Hg (P < 0.001) by hydrochlorothiazide or amlodipine, and 10.3/5.0 mm Hg (P < 0.001) by double therapy compared with placebo. Twenty-five major CVD events occurred. Non-significant trends towards fewer CVD events with greater BP reductions are evident: hazard ratios (HR) 0.82 [95% confidence interval (CI): 0.37-1.81] for 3.5 mm Hg SBP reduction; HR 0.45 (95% CI: 0.19-1.04) for 6.8 mm Hg; and HR 0.25 (0.05-1.18) for 10.3 mm Hg reduction for primary composite of CV death, MI, stroke, or significant heart failure. Sizeable reductions in BP, with potential for substantial CVD reduction, can be safely achieved using combinations of BP drugs in the elderly with normal high and Stage 1 hypertension. NCT01259297. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Exercise-induced decrease in insular cortex rCBF during postexercise hypotension.

PubMed

Lamb, Kala; Gallagher, Kevin; McColl, Roderick; Mathews, Dana; Querry, Ross; Williamson, Jon W

2007-04-01

The insular cortex (IC), a region of the brain involved in blood pressure (BP) modulation, shows decreases in regional cerebral blood flow (rCBF) during postexercise hypotension (PEH). To determine whether changes in IC neural activity were caused by prior exercise or by changes in BP, this investigation compared patterns of rCBF during periods of hypotension, which was induced by prior exercise (i.e., PEH) and sodium nitroprusside (SNP) infusion and a cold pressor (CP), to restore BP. Ten subjects were studied on three different days with randomly assigned conditions: i) resting baseline; ii) PEH; and iii) SNP-induced hypotension (matched to the PEH BP decrease). Data were collected for heart rate (HR) and mean BP, and rCBF was assessed using single-photon emission computed tomography (SPECT) as an index of brain activation. Using ANOVA across conditions, there were differences (P<0.05; mean +/- SD) from baseline during PEH for HR (+12 +/- 3 bpm) and mean BP (-8 +/- 2 mm Hg) and during SNP-induced hypotension (HR = +15 +/- 4 bpm; MBP = -9 +/- 2 mm Hg), with no differences between PEH and SNP. After exercise, there were decreases (P<0.05) in the leg sensorimotor area, anterior cingulate, and the right and left inferior thalamus, right inferior insula, and left anterior insular regions. During SNP-induced hypotension, there were significant increases in the right and left inferior thalamus and the right and left inferior anterior IC. CP during PEH increased BP and IC activity. Data show that reductions in IC neural activity are not caused by acute BP decreases. Findings suggest that exercise can lead to a temporary decrease in IC neural activity, which may be a significant neural factor contributing to PEH.

Riser Pattern Is a Novel Predictor of Adverse Events in Heart Failure Patients With Preserved Ejection Fraction.

PubMed

Komori, Takahiro; Eguchi, Kazuo; Saito, Toshinobu; Hoshide, Satoshi; Kario, Kazuomi

2017-01-25

The cardiovascular prognosis of heart failure with preserved ejection fraction (HFpEF) has been shown to be similar to that of heart failure with reduced ejection fraction (HFrEF). It is unknown which factors predict cardiovascular outcome in HFpEF. We tested the hypothesis that the abnormal pattern of circadian blood pressure (BP) rhythm known as the riser BP pattern is associated with adverse outcomes in HFpEF.Methods and Results:We performed a prospective, observational cohort study of hospitalized HF patients who underwent ambulatory BP monitoring (ABPM). Five hundred and sixteen hospitalized HF patients (age, 69±13 years; male, n=321 [62%]; female, n=195 [38%]) were followed up for a median 20.9 months. The composite outcome consisting of all-cause mortality and cardiovascular events was observed in 220 patients. On Kaplan-Meier analysis, the riser BP pattern subgroup had a significantly higher incidence of the composite outcome than the other subgroups of HFpEF patients (HR, 3.01; 95% CI: 1.54-6.08, P<0.01), but not the HFrEF patients. The riser BP pattern was found to be a novel predictor of cardiovascular outcome in HFpEF patients.

The interplinian activity at Somma-Vesuvius in the last 3500 years

USGS Publications Warehouse

Rolandi, G.; Petrosino, P.; Mc, Geehin J.

1998-01-01

Between 1884 B.C. and A.D. 472, eruptive activity at Somma-Vesuvius was dominated by the three plinian eruptions of Avellino (3550 yr B.P.), Pompei (A.D. 79) and A.D. 472 and, as a result, little attention has been given to the intervening interplinian activity. The interplinian events are here reconstructed using new data from twenty stratigraphic sections around the lower flanks of the volcano. Three main eruptions have been identified fro the protohistoric period (3550 yr B.P.-A.D. 79). The first two occurred shortly after the Avellino event and both show a progression from magmatic to phreatomagmatic behaviour. The third eruption (2700 B.P.) consisted of five phreatomagmetic episodes separated by the emplacement of mud flows. Only one event, the explosive erupton of A.D. 203, has been identified for the ancient historic period (A.D. 79-472). In contrast, the A.D. 472 eruption was followed during the medievel period (A.D. 472-1631) by comparatively vigorous interplinian activity, including four strombolian-phreatomagmatic events and extensive lava effusion, which formed a summit cone (destroyed in A.D. 1631) similar to that on Vesuvius today. Such regular alternations of plinian and interplinian events are evident only since 3550 yr B.P. and provide important constraints for forecasting future behaviour at Somma-Vesuvius.

Main processes of the Atlantic cold tongue interannual variability

NASA Astrophysics Data System (ADS)

Planton, Yann; Voldoire, Aurore; Giordani, Hervé; Caniaux, Guy

2018-03-01

The interannual variability of the Atlantic cold tongue (ACT) is studied by means of a mixed-layer heat budget analysis. A method to classify extreme cold and warm ACT events is proposed and applied to ten various analysis and reanalysis products. This classification allows 5 cold and 5 warm ACT events to be selected over the period 1982-2007. Cold (warm) ACT events are defined by the presence of negative (positive) sea surface temperature (SST) anomalies at the center of the equatorial Atlantic in late boreal spring, preceded by negative (positive) zonal wind stress anomalies in the western equatorial Atlantic. An ocean general circulation model capable of reconstructing the interannual variability of the ACT correctly is used to demonstrate that cold ACT events develop rapidly from May to June mainly due to intense cooling by vertical mixing and horizontal advection. The simulated cooling at the center of the basin is the result of the combined effects of non-local and local processes. The non-local process is an upwelling associated with an eastward-propagating Kelvin wave, which makes the mixed-layer more shallow and preconditions the upper layers to be cooled by an intense heat loss at the base of the mixed-layer, which is amplified by a stronger local injection of energy from the atmosphere. The early cooling by vertical mixing in March is also shown to be a good predictor of June cooling. In July, horizontal advection starts to warm the mixed-layer abnormally and damps SST anomalies. The advection anomalies, which result from changes in the horizontal temperature gradient, are associated in some cases with the propagation of Rossby waves along the equator. During warm ACT events, processes are reversed, generating positive SST anomalies: a downwelling Kelvin wave triggers stratification anomalies and mixed-layer depth anomalies, amplified by a weaker injection of energy from the atmosphere in May-June. In July, warm ACT events are abnormally cooled due to negative horizontal advection anomalies resulting from processes similar to those that occur during cold ACT events. This additional cooling process extends the period of cooling of the ACT, reducing SST anomalies.

Improving activity recognition using a wearable barometric pressure sensor in mobility-impaired stroke patients.

PubMed

Massé, Fabien; Gonzenbach, Roman R; Arami, Arash; Paraschiv-Ionescu, Anisoara; Luft, Andreas R; Aminian, Kamiar

2015-08-25

Stroke survivors often suffer from mobility deficits. Current clinical evaluation methods, including questionnaires and motor function tests, cannot provide an objective measure of the patients' mobility in daily life. Physical activity performance in daily-life can be assessed using unobtrusive monitoring, for example with a single sensor module fixed on the trunk. Existing approaches based on inertial sensors have limited performance, particularly in detecting transitions between different activities and postures, due to the inherent inter-patient variability of kinematic patterns. To overcome these limitations, one possibility is to use additional information from a barometric pressure (BP) sensor. Our study aims at integrating BP and inertial sensor data into an activity classifier in order to improve the activity (sitting, standing, walking, lying) recognition and the corresponding body elevation (during climbing stairs or when taking an elevator). Taking into account the trunk elevation changes during postural transitions (sit-to-stand, stand-to-sit), we devised an event-driven activity classifier based on fuzzy-logic. Data were acquired from 12 stroke patients with impaired mobility, using a trunk-worn inertial and BP sensor. Events, including walking and lying periods and potential postural transitions, were first extracted. These events were then fed into a double-stage hierarchical Fuzzy Inference System (H-FIS). The first stage processed the events to infer activities and the second stage improved activity recognition by applying behavioral constraints. Finally, the body elevation was estimated using a pattern-enhancing algorithm applied on BP. The patients were videotaped for reference. The performance of the algorithm was estimated using the Correct Classification Rate (CCR) and F-score. The BP-based classification approach was benchmarked against a previously-published fuzzy-logic classifier (FIS-IMU) and a conventional epoch-based classifier (EPOCH). The algorithm performance for posture/activity detection, in terms of CCR was 90.4 %, with 3.3 % and 5.6 % improvements against FIS-IMU and EPOCH, respectively. The proposed classifier essentially benefits from a better recognition of standing activity (70.3 % versus 61.5 % [FIS-IMU] and 42.5 % [EPOCH]) with 98.2 % CCR for body elevation estimation. The monitoring and recognition of daily activities in mobility-impaired stoke patients can be significantly improved using a trunk-fixed sensor that integrates BP, inertial sensors, and an event-based activity classifier.

Severe Weather Guide Mediterranean Ports - 33. Tangier

DTIC Science & Technology

1990-11-01

building tctt, eas. : .u’.d r.i f on l’ues. b. North to northwest wrrds usually accompany cold frontal passages. .2 or vato :an rayoe Strongest fronts...principal A-S-Nao2.s A. , 0 Rue Du Clateii-Lor, B.P. 426 irect-or, Tec!!. Info~at-,cn A-aPo11 x 292075 - Brost Cadex, Franc. Defense Adv. Rach. projects

Can animal habitat use patterns influence their vulnerability to extreme climate events? An estuarine sportfish case study.

PubMed

Boucek, Ross E; Heithaus, Michael R; Santos, Rolando; Stevens, Philip; Rehage, Jennifer S

2017-10-01

Global climate forecasts predict changes in the frequency and intensity of extreme climate events (ECEs). The capacity for specific habitat patches within a landscape to modulate stressors from extreme climate events, and animal distribution throughout habitat matrices during events, could influence the degree of population level effects following the passage of ECEs. Here, we ask (i) does the intensity of stressors of an ECE vary across a landscape? And (ii) Do habitat use patterns of a mobile species influence their vulnerability to ECEs? Specifically, we measured how extreme cold spells might interact with temporal variability in habitat use to affect populations of a tropical, estuarine-dependent large-bodied fish Common Snook, within Everglades National Park estuaries (FL US). We examined temperature variation across the estuary during cold disturbances with different degrees of severity, including an extreme cold spell. Second, we quantified Snook distribution patterns when the passage of ECEs is most likely to occur from 2012 to 2016 using passive acoustic tracking. Our results revealed spatial heterogeneity in the intensity of temperature declines during cold disturbances, with some habitats being consistently 3-5°C colder than others. Surprisingly, Snook distributions during periods of greatest risk to experience an extreme cold event varied among years. During the winters of 2013-2014 and 2014-2015 a greater proportion of Snook occurred in the colder habitats, while the winters of 2012-2013 and 2015-2016 featured more Snook observed in the warmest habitats. This study shows that Snook habitat use patterns could influence vulnerability to extreme cold events, however, whether Snook habitat use increases or decreases their vulnerability to disturbance depends on the year, creating temporally dynamic vulnerability. Faunal global change research should address the spatially explicit nature of extreme climate events and animal habitat use patterns to identify potential mechanisms that may influence population effects following these disturbances. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

The Autoimmune Skin Disease Bullous Pemphigoid: The Role of Mast Cells in Autoantibody-Induced Tissue Injury

PubMed Central

Fang, Hui; Zhang, Yang; Li, Ning; Wang, Gang; Liu, Zhi

2018-01-01

Bullous pemphigoid (BP) is an autoimmune and inflammatory skin disease associated with subepidermal blistering and autoantibodies directed against the hemidesmosomal components BP180 and BP230. Animal models of BP were developed by passively transferring anti-BP180 IgG into mice, which recapitulates the key features of human BP. By using these in vivo model systems, key cellular and molecular events leading to the BP disease phenotype are identified, including binding of pathogenic IgG to its target, complement activation of the classical pathway, mast cell degranulation, and infiltration and activation of neutrophils. Proteinases released by infiltrating neutrophils cleave BP180 and other hemidesmosome-associated proteins, causing DEJ separation. Mast cells and mast cell-derived mediators including inflammatory cytokines and proteases are increased in lesional skin and blister fluids of BP. BP animal model evidence also implicates mast cells in the pathogenesis of BP. However, recent studies questioned the pathogenic role of mast cells in autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, and epidermolysis bullosa acquisita. This review highlights the current knowledge on BP pathophysiology with a focus on a potential role for mast cells in BP and mast cell-related critical issues needing to be addressed in the future. PMID:29545809

Lack of independent relationships between left ventricular mass and cardiovascular reactivity to physical and psychological stress in the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

PubMed

Markovitz, J H; Raczynski, J M; Lewis, C E; Flack, J; Chesney, M; Chettur, V; Hardin, J M; Johnson, E

1996-09-01

The objective of this study was to determine whether exaggerated blood pressure (BP) reactivity to stress and psychosocial characteristics are related to left ventricular mass (LVM) in a large cohort of young adults. Analyses were conducted with 3,742 participants of the CARDIA study (945 white men, 1,024 white women, 781 black men, and 992 black women), evaluated in 1990 to 1091 with echocardiographic measurement of LVM. Analyses were stratified by gender and race. The relationships of LVM/height2.7 and cardiovascular reactivity to physical and psychological stressors (treadmill exercise, cold pressor, video game, and star-tracing tasks), were examined in both univariate and multivariate analyses adjusting for baseline BP, weight, and other relevant biobehavioral variables. The relationships between LVM and several psychosocial characteristics (hostility, anger suppression, anxiety, depressive symptoms, and education) were also assessed. Systolic blood pressure (SBP) reactivity to exercise was significantly related to LVM in black and white men; LVM was 10% greater among white men with exaggerated (upper quintile) peak exercise SBP than among other white men. SBP reactivity to the cold pressor test was related to LVM in all race/gender groups, although the relationship remained significant only among white men and women in the multivariate analysis. Diastolic blood pressure (DBP) reactivity to the video game was related to LVM only among black men in adjusted analyses. After adjusting for resting BP, weight, and other covariates in linear multiple regression models, SBP reactivity to exercise explained only 3% of the variance in LVM among white men. Otherwise, reactivity to other stressors or psychosocial variables accounted for no more than 1% of the variance in LVM. It was concluded that among a cohort of young adults, blood pressure reactivity to physical and mental stressors did not add substantially to the prediction of LVM when resting BP, weight, and other covariates were taken into account.

The Promoter of AtUSP Is Co-regulated by Phytohormones and Abiotic Stresses in Arabidopsis thaliana.

PubMed

Bhuria, Monika; Goel, Parul; Kumar, Sanjay; Singh, Anil K

2016-01-01

Universal stress proteins (USPs) are known to be expressed in response to various abiotic stresses in a wide variety of organisms, such as bacteria, archaebacteria, protists, algae, fungi, plants, and animals. However, in plants, biological function of most of the USPs still remains obscure. In the present study, Arabidopsis USP gene ( AtUSP ) showed induction in response to abscisic acid (ABA) and various abiotic stresses viz . heat, dehydration, salt, osmotic, and cold stresses. Additionally, in silico analysis of AtUSP promoter identified several cis -elements responsive to phytohormones and abiotic stresses such as ABRE, ERE, DRE, and HSE, etc. To functionally validate the AtUSP promoter, the 1115 bp region of promoter was characterized under phytohormone and abiotic stress treatments. Deletion analysis of promoter was carried out by cloning the full length promoter (D0) and its three 5' deletion derivatives, D1 (964 bp), D2 (660 bp), and D3 (503 bp) upstream of the β-glucuronidase (GUS) reporter gene, which were then stably transformed in Arabidopsis plants. The AtUSP promoter (D0) showed minimal activity under non-stress conditions which was enhanced in response to phytohormone treatments (ABA and ACC) and abiotic stresses such as dehydration, heat, cold, salt, and osmotic stresses. The seedlings harboring D1 and D2 deletion fragments showed constitutive GUS expression even under control condition with increased activity almost under all the treatments. However, D3 seedlings exhibited complete loss of activity under control condition with induction under ACC treatment, dehydration, heat, oxidative, salt, and osmotic stresses. Thus, present study clearly showed that AtUSP promoter is highly inducible by phytohormones and multiple abiotic stresses and it can be exploited as stress inducible promoter to generate multi-stress tolerant crops with minimal effects on their other important traits.

Genome-Wide Linkage and Regional Association Study of Blood Pressure Response to the Cold Pressor Test in Han Chinese: The GenSalt Study

PubMed Central

Yang, Xueli; Gu, Dongfeng; He, Jiang; Hixson, James E.; Rao, Dabeeru C.; Lu, Fanghong; Mu, Jianjun; Jaquish, Cashell E.; Chen, Jing; Huang, Jianfeng; Shimmin, Lawrence C.; Rice, Treva K.; Chen, Jichun; Wu, Xigui; Liu, Depei; Kelly, Tanika N.

2014-01-01

Background Blood pressure (BP) response to cold pressor test (CPT) is associated with increased risk of cardiovascular disease. We performed a genome-wide linkage scan and regional association analysis to identify genetic determinants of BP response to CPT. Methods and Results A total of 1,961 Chinese participants completed the CPT. Multipoint quantitative trait linkage analysis was performed, followed by single-marker and gene-based analyses of variants in promising linkage regions (logarithm of odds, LOD ≥ 2). A suggestive linkage signal was identified for systolic BP (SBP) response to CPT at 20p13-20p12.3, with a maximum multipoint LOD score of 2.37. Based on regional association analysis with 1,351 SNPs in the linkage region, we found that marker rs2326373 at 20p13 was significantly associated with mean arterial pressure (MAP) responses to CPT (P = 8.8×10−6) after FDR adjustment for multiple comparisons. A similar trend was also observed for SBP response (P = 0.03) and DBP response (P = 4.6×10−5). Results of gene-based analyses showed that variants in genes MCM8 and SLC23A2 were associated with SBP response to CPT (P = 4.0×10−5 and 2.7×10−4, respectively), and variants in genes MCM8 and STK35 were associated with MAP response to CPT (P = 1.5×10−5 and 5.0×10−5, respectively). Conclusions Within a suggestive linkage region on chromosome 20, we identified a novel variant associated with BP responses to CPT. We also found gene-based associations of MCM8, SLC23A2 and STK35 in this region. Further work is warranted to confirm these findings. Clinical Trial Registration URL: http://www.clinicaltrials.gov; Unique identifier: NCT00721721. PMID:25028485

Long-term (52-week) safety and efficacy of Sacubitril/valsartan in Asian patients with hypertension.

PubMed

Supasyndh, Ouppatham; Sun, Ningling; Kario, Kazuomi; Hafeez, Kudsia; Zhang, Jack

2017-05-01

Sacubitril/valsartan (LCZ696), a first-in-class angiotensin receptor-neprilysin inhibitor, demonstrated significant reductions in office and 24 h ambulatory blood pressure (BP) over 8 weeks in Asian patients with hypertension. This 52-week extension to the 8-week core study was aimed at evaluating the long-term safety, tolerability and efficacy of sacubitril/valsartan. Patients who completed an 8-week randomized study (the core study) were enrolled in this 52-week open-label study and received sacubitril/valsartan 200 mg QD. The sacubitril/valsartan dose was uptitrated to 400 mg QD if BP was uncontrolled (>140/90 mm Hg) after 4 weeks. Subsequently, in patients with uncontrolled BP, treatment was intensified every 4 weeks with amlodipine 5-10 mg followed by hydrochlorothiazide 6.25-25 mg. Of the 341 patients enrolled, 7 (2.1%) discontinued the study drug due to adverse events (AEs). The incidence of AEs and serious AEs were 63.9 and 3.8%, respectively, and no deaths were reported in this study. The most frequent AEs were nasopharyngitis (18.2%) and dizziness (8.8%). Events that were potentially indicative of low BP were infrequent. One patient reported mild transient angioedema (lasting 2.5 h) that resolved without treatment but led to study drug discontinuation. The sacubitril/valsartan-based regimen provided clinically significant mean sitting systolic BP (msSBP) and mean sitting diastolic BP (msDBP) reductions from baseline (-24.7/-16.2 mm Hg). The overall BP control, msSBP and msDBP response rates were 75.3, 90.6 and 87.6%, respectively. Long-term use of sacubitril/valsartan was generally safe and well-tolerated in patients with hypertension and provided significant BP reductions from baseline.

Interannual to Decadal Variability of Atlantic Water in the Nordic and Adjacent Seas

NASA Technical Reports Server (NTRS)

Carton, James A.; Chepurin, Gennady A.; Reagan, James; Haekkinen, Sirpa

2011-01-01

Warm salty Atlantic Water is the main source water for the Arctic Ocean and thus plays an important role in the mass and heat budget of the Arctic. This study explores interannual to decadal variability of Atlantic Water properties in the Nordic Seas area where Atlantic Water enters the Arctic, based on a reexamination of the historical hydrographic record for the years 1950-2009, obtained by combining multiple data sets. The analysis shows a succession of four multi-year warm events where temperature anomalies at 100m depth exceed 0.4oC, and three cold events. Three of the four warm events lasted 3-4 years, while the fourth began in 1999 and persists at least through 2009. This most recent warm event is anomalous in other ways as well, being the strongest, having the broadest geographic extent, being surface-intensified, and occurring under exceptional meteorological conditions. Three of the four warm events were accompanied by elevated salinities consistent with enhanced ocean transport into the Nordic Seas, with the exception of the event spanning July 1989-July 1993. Of the three cold events, two lasted for four years, while the third lasted for nearly 14 years. Two of the three cold events are associated with reduced salinities, but the cold event of the 1960s had elevated salinities. The relationship of these events to meteorological conditions is examined. The results show that local surface heat flux variations act in some cases to reinforce the anomalies, but are too weak to be the sole cause.

Late Neolithic phytolith and charcoal records of human activities and vegetation change in Shijiahe culture, Tanjialing site, China

PubMed Central

Zhu, Xiao Hong; Li, Bing; Ma, Chun Mei; Zhu, Cheng; Wu, Li; Liu, Hui

2017-01-01

There is significant archaeological evidence marking the collapse of the Shijiahe culture in the middle reaches of the Yangtze River in China during the late Neolithic Period. However, the causes for this cultural collapse remain unclear. Our sedimentary records from a 3.3 m long profile and 76 phytolith and charcoal samples from the Tanjialing archaeological sites provide records of interactions between an ancient culture and vegetation change. During the early Shijiahe culture (c, 4850–4400 cal BP), the climate was warm and humid. Fire was intensively used to clear the vegetation. In the mid-period of the Shijiahe culture (c, 4400–4200 cal BP), the climate became slightly dry-cold and this was accompanied by decreasing water, leading to settlements. From c, 4200 cal BP, severe drought eroded the economic foundation of rice-cultivation. These conditions forced people to abandon the Shijiahe ancient city to find water in other regions, leading to the collapse of the Shijiahe culture. PMID:28542219

Late Neolithic phytolith and charcoal records of human activities and vegetation change in Shijiahe culture, Tanjialing site, China.

PubMed

Zhu, Xiao Hong; Li, Bing; Ma, Chun Mei; Zhu, Cheng; Wu, Li; Liu, Hui

2017-01-01

There is significant archaeological evidence marking the collapse of the Shijiahe culture in the middle reaches of the Yangtze River in China during the late Neolithic Period. However, the causes for this cultural collapse remain unclear. Our sedimentary records from a 3.3 m long profile and 76 phytolith and charcoal samples from the Tanjialing archaeological sites provide records of interactions between an ancient culture and vegetation change. During the early Shijiahe culture (c, 4850-4400 cal BP), the climate was warm and humid. Fire was intensively used to clear the vegetation. In the mid-period of the Shijiahe culture (c, 4400-4200 cal BP), the climate became slightly dry-cold and this was accompanied by decreasing water, leading to settlements. From c, 4200 cal BP, severe drought eroded the economic foundation of rice-cultivation. These conditions forced people to abandon the Shijiahe ancient city to find water in other regions, leading to the collapse of the Shijiahe culture.

[2013 Ambulatory blood pressure monitoring recommendations for the diagnosis of adult hypertension, assessment of cardiovascular and other hypertension-associated risk, and attainment of therapeutic goals (summary). Joint recommendations from the International Society for Chronobiology (ISC), American Association of Medical Chronobiology and Chronotherapeutics (AAMCC), Spanish Society of Applied Chronobiology, Chronotherapy, and Vascular Risk (SECAC), Spanish Society of Atherosclerosis (SEA), and Romanian Society of Internal Medicine (RSIM)].

PubMed

Hermida, Ramón C; Smolensky, Michael H; Ayala, Diana E; Portaluppi, Francesco; Crespo, Juan J; Fabbian, Fabio; Haus, Erhard; Manfredini, Roberto; Mojón, Artemio; Moyá, Ana; Piñeiro, Luis; Ríos, María T; Otero, Alfonso; Balan, Horia; Fernández, José R

2013-01-01

Correlation between systolic (SBP) and diastolic (DBP) blood pressure (BP) level and target organ damage, cardiovascular disease (CVD) risk, and long-term prognosis is much greater for ambulatory BP monitoring (ABPM) than daytime office measurements. The 2013 ABPM guidelines specified herein are based on ABPM patient outcomes studies and constitute a substantial revision of current knowledge. The asleep SBP mean and sleep-time relative SBP decline are the most significant predictors of CVD events, both individually as well as jointly when combined with other ABPM-derived prognostic markers. Thus, they should be preferably used to diagnose hypertension and assess CVD and other associated risks. Progressive decrease by therapeutic intervention in the asleep BP mean is the most significant predictor of CVD event-free interval. The 24 h BP mean is not recommended to diagnose hypertension because it disregards the more valuable clinical information pertaining to the features of the 24 h BP pattern. Persons with the same 24 h BP mean may display radically different 24 h BP patterns, ranging from extreme-dipper to riser types, representative of markedly different risk states. Classification of individuals by comparing office with either the 24 h or awake BP mean as "masked normotensives" (elevated clinic BP but normal ABPM), which should replace the terms of "isolated office" or "white-coat hypertension", and "masked hypertensives" (normal clinic BP but elevated ABPM) is misleading and should be avoided because it disregards the clinical significance of the asleep BP mean. Outcome-based ABPM reference thresholds for men, which in the absence of compelling clinical conditions are 135/85 mmHg for the awake and 120/70 mmHg for the asleep SBP/DBP means, are lower by 10/5 mmHg for SBP/DBP in uncomplicated, low-CVD risk, women and lower by 15/10 mmHg for SBP/DBP in male and female high-risk patients, e.g., with diabetes, chronic kidney disease (CKD), and/or past CVD events. In the adult population, the combined prevalence of masked normotension and masked hypertension is >35%. Moreover, >20% of "normotensive" adults have a non-dipper BP profile and, thus, are at relatively high CVD risk. Clinic BP measurements, even if supplemented with home self-measurements, are unable to quantify 24 h BP patterning and asleep BP level, resulting in potential misclassification of up to 50% of all evaluated adults. ABPM should be viewed as the new gold standard to diagnose true hypertension, accurately assess consequent tissue/organ, maternal/fetal, and CVD risk, and individualize hypertension chronotherapy. ABPM should be a priority for persons likely to have a blunted nighttime BP decline and elevated CVD risk, i.e., those who are elderly and obese, those with secondary or resistant hypertension, and those diagnosed with diabetes, CKD, metabolic syndrome, and sleep disorders. Copyright © 2013 Elsevier España, S.L. y SEA. All rights reserved.

Holocene fire activity and vegetation response in South-Eastern Iberia

NASA Astrophysics Data System (ADS)

Gil-Romera, Graciela; Carrión, José S.; Pausas, Juli G.; Sevilla-Callejo, Miguel; Lamb, Henry F.; Fernández, Santiago; Burjachs, Francesc

2010-05-01

Since fire has been recognized as an essential disturbance in Mediterranean landscapes, the study of long-term fire ecology has developed rapidly. We have reconstructed a sequence of vegetation dynamics and fire changes across south-eastern Iberia by coupling records of climate, fire, vegetation and human activities. We calculated fire activity anomalies (FAAs) in relation to 3 ka cal BP for 10-8 ka cal BP, 6 ka cal BP, 4 ka cal BP and the present. For most of the Early to the Mid-Holocene uneven, but low fire events were the main vegetation driver at high altitudes where broadleaved and coniferous trees presented a highly dynamic post-fire response. At mid-altitudes in the mainland Segura Mountains, fire activity remained relatively stable, at similar levels to recent times. We hypothesize that coastal areas, both mountains and lowlands, were more fire-prone landscapes as biomass was more likely to have accumulated than in the inland regions, triggering regular fire events. The wet and warm phase towards the Mid-Holocene (between ca 8 and 6 ka cal BP) affected the whole region and promoted the spread of mesophytic forest co-existing with Pinus, as FAAs appear strongly negative at 6 ka cal BP, with a less important role of fire. Mid and Late Holocene landscapes were shaped by an increasing aridity trend and the rise of human occupation, especially in the coastal mountains where forest disappeared from ca 2 ka cal BP. Mediterranean-type vegetation (evergreen oaks and Pinus pinaster- halepensis types) showed the fastest post-fire vegetation dynamics over time.

Impact of the Management of Type B Aortic Dissection on the Long-Term Blood Pressure.

PubMed

Delsart, Pascal; Ledieu, Guillaume Jean; Ramdane, Nassima; Sobocinski, Jonathan Paul; Clough, Rachel Elizabeth; Azzaoui, Richard Oussama; Mounier-Vehier, Claire; Nienaber, Christoph Anton; Haulon, Stephan

2017-08-01

Ambulatory blood pressure (BP) measurement (ABPM) is recommended to assess optimal BP control, and we studied its influence after an acute type B aortic dissection (ATBAD). We retrospectively collected data from 111 patients with ATBAD from January 2004 to September 2014. Controlled BP group was defined according to a 24-hour BP under 130/80 mm Hg during chronic phase. The population consisted of 85 men, with a mean age of 61 ± 13 years and mean body mass index of 28 ± 6 kg/m 2 . The median delay between ambulatory BP measurement and ATBAD was 2 (0.3 to 4) months. The mean 24-hour BP of the entire population was 124/71 ± 15/8.8 mm Hg. BP was not controlled in 41 patients (37%). The treatment score at discharge was 3.9 ± 1.4. The mean glomerular filtration rate was 83 ± 28 ml/min/1.73 m 2 , with no difference between groups. Visceral stent implantation in the acute phase (odds ratio [OR] 3.857 [1.199 to 12.406], p = 0.023), higher left ventricular ejection fraction (OR 1.092 [1.005 to 1.187], p = 0.038), and higher platelet count at discharge (OR 1.064 [1.018 to 1.112], p = 0.006) were identified as predictors of good BP control by multivariate analysis. The analysis showed that nighttime systolic BP was associated with aortic events during follow-up (hazard ratio [HR] 5.2 [1.01 to 27.2], p = 0.049), particularly for a threshold of 124 mm Hg or more (HR 1.967 [1.052 to 3.678], p = 0.0341). Nighttime pulse pressure showed also its significance (HR 20.1 [1.4 to 282.7], p = 0.026). In conclusion, subclinical renal malperfusion revascularization seems to improve BP control. A greater nighttime systolic BP was associated with the risk of new aortic events during follow-up. Copyright © 2017 Elsevier Inc. All rights reserved.

Involvement of 4E-BP phosphorylation in embryonic development of the silkworm, Bombyx mori.

PubMed

Gu, Shi-Hong; Young, Shun-Chieh; Tsai, Wen-Hsien; Lin, Ju-Ling; Lin, Pei-Ling

2011-07-01

Phosphorylation of the translational repressor 4E-binding protein (4E-BP) plays a critical role in regulating the overall translation levels in cells. In the present study, we investigated 4E-BP phosphorylation of Bombyx mori eggs by an immunoblot analysis of a conserved phospho-specific antibody to 4E-BP and demonstrated its role during embryonic development. When HCl treatment was applied to diapause-destined eggs at 20 h after oviposition, a dramatic increase in the phosphorylation of 4E-BP occurred 5 min after treatment with HCl, and high phosphorylation levels were maintained throughout embryonic stage in HCl-treated eggs compared to those in diapause (control) eggs. When HCl treatment was applied to diapause eggs on day 10 after oviposition, no dramatic activation in 4E-BP phosphorylation occurred, indicating stage-specific effects of HCl treatment. In both non-diapause eggs and eggs whose diapause had been terminated by chilling of diapausing eggs at 5°C for 70 days and then were transferred to 25°C, high phosphorylation levels of 4E-BP were also detected. Moreover, 4E-BP phosphorylation dramatically increased when dechorionated eggs were incubated in medium. The addition of rapamycin, a specific inhibitor of mammalian target of rapamycin (TOR) signaling, and LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, but not the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor, U0126, dose-dependently inhibited 4E-BP phosphorylation in dechorionated eggs, indicating that PI3K/TOR signaling is an upstream signaling event involved in 4E-BP phosphorylation. Examination of 4E-BP gene expression levels showed no differences between treatments with HCl and water in the first hour after treatment, indicating that changes in phosphorylation of 4E-BP upon HCl treatment are mainly regulated at the post-transcriptional level. In addition, MAPK pathways and glycogen synthase kinase (GSK)-3β phosphorylation were not significantly affected in the first hour after HCl treatment. These results demonstrate that the rapid phosphorylation of 4E-BP is an early signaling event in embryonic development in the eggs whose diapause initiation was prevented by HCl treatment, thus being involved in the embryonic development of B. mori. Copyright © 2011 Elsevier Ltd. All rights reserved.

A 27 ka paleoenvironmental lake sediment record from Taro Co, central Tibetan Plateau: implications for the interplay between monsoon and the Westerlies

NASA Astrophysics Data System (ADS)

Wang, J.; Ma, Q.; Huang, L.; Ju, J.; Guo, Y.; Lin, X.; Li, Y.; Zhu, L.

2017-12-01

The climate of Tibetan Plateau (TP) is mainly influenced by the Indian Ocean Summer Monsoon (IOSM) and the Westerlies. The interaction of these two air masses is therefore a crucial scientific issue to understand how they impact the climate in this area, especially in the geological times. However, constrained by the available archives, researches on this topic are still very few in the hinterland of the TP, especially covering the Last Glacial Maximum (LGM) period. Here we present a new lake sediment record retrieved from Taro Co covering the last 27 ka to elucidate how the IOSM and the Westerlies interact and the possible mechanisms. Taro Co (486 km2, Dmax: 132m, 4565 m a.s.l., currently closed), located on the central TP, is a fresh lake with the major supply from glaciers. Two parallel piston cores as well as several gravity cores were retrieved from the deepest parts. These cores were correlated based on high resolution XRF scanning and a continuous 1069 cm-long core was finally integrated. Chronology was determined by 210Pb, 137Cs and AMS 14C measurements. Multidiscipline analyses including grain size, total organic carbon (TOC), total nitrogen, diatom, ostracod, pollen and n-alkanes were accomplished to reconstruct paleoenvironmental changes. The lake level of Taro Co was low since 27 cal ka BP indicated by very coarse materials and diatom assemblages with gradually increased temperature and salinity (TOC and carbonate getting higher). The terrestrial water input decreased continuously reflected by such elements as Si, Ti, Fe, K. It is likely that there was a sedimentation gap between 961-954cm, corresponding to 23.4 to 18.6 cal ka BP probably demonstrated Taro Co was very shallow at that period. The first prominent abrupt change of most proxies was observed at 14.7 cal ka BP showing a great lake deepening which likely indicated an enhancement of IOSM. There were several spells with abrupt changes of cold/warm stages before the Holocene and the Younger Dryas event occurred at 11.8 cal ka BP. During the Holocene, carbonate dissolution was identified at 9.76 to 3.44 cal ka BP which indicated a high moisture availability hence high lake level even the lake became an open system. More detailed results and comparison with other studies are still in progress to have an insight into the record and its possible controlling mechanism.

Antihypertensive treatment and stroke prevention: are angiotensin receptor blockers superior to other antihypertensive agents?

PubMed

Armario, Pedro; de la Sierra, Alejandro

2009-06-01

Stroke remains a common vascular event with high mortality and morbidity. After heart disease, stroke is the second leading cause of death worldwide in adult persons. Silent or subclinical stroke is likely to occur with even greater frequency than clinical stroke and increases the risk of subsequent cerebrovascular events. Hypertension is by far the single most important controllable risk factor for stroke. The relationship between blood pressure (BP) and stroke mortality is strong, linear, and continuous in subjects with levels of BP higher than 115/75 mm Hg. Blood pressure reduction by antihypertensive treatment is clearly efficacious in the prevention of stroke (both primary and secondary). Although meta-analyses suggest that BP reduction, per se, is the most important determinant for stroke risk reduction, the question is if specific classes of antihypertensive drugs offer special protection against stroke is still controversial. Some studies have suggested that angiotensin receptors blockers (ARBs) appear to offer additional protection against stroke. This has been hypothesized in studies in hypertensives, such as LIFE and SCOPE, and especially in the only comparative trial focused on secondary stroke prevention. In the MOSES trial, the comparison of eprosartan versus nitrendipine in patients with a previous stroke resulted, despite a similar BP reduction, in a significant reduction in the primary composite endpoint of total mortality plus cardiovascular and cerebrovascular events, including recurrent events. These results may suggest a blood pressure-independent effect of ARBs, which can be mediated through several mechanisms, including their ability to counteract other markers of target organ damage, but also through a direct neuroprotective effect.

Late Quaternary paleoclimate of western Alaska inferred from fossil chironomids and its relation to vegetation histories

USGS Publications Warehouse

Kurek, Joshua; Cwynar, Les C.; Ager, Thomas A.; Abbott, Mark B.; Edwards, Mary E.

2009-01-01

Fossil Chironomidae assemblages (with a few Chaoboridae and Ceratopogonidae) from Zagoskin and Burial Lakes in western Alaska provide quantitative reconstructions of mean July air temperatures for periods of the late-middle Wisconsin (~39,000-34,000 cal yr B.P.) to the present. Inferred temperatures are compared with previously analyzed pollen data from each site summarized here by indirect ordination. Paleotemperature trends reveal substantial differences in the timing of climatic warming following the late Wisconsin at each site, although chronological uncertainty exists. Zagoskin Lake shows early warming beginning at about 21,000 cal yr B.P., whereas warming at Burial Lake begins ~4000 years later. Summer climates during the last glacial maximum (LGM) were on average ~3.5C° below the modern temperatures at each site. Major shifts in vegetation occurred from ~19,000 to 10,000 cal yr B.P. at Zagoskin Lake and from ~17,000 to 10,000 cal yr B.P. at Burial Lake. Vegetation shifts followed climatic warming, when temperatures neared modern values. Both sites provide evidence of an early postglacial thermal maximum at ~12,300 cal yr B.P. These chironomid records, combined with other insect-based climatic reconstructions from Beringia, indicate that during the LGM: (1) greater continentality likely influenced regions adjacent to the Bering Land Bridge and (2) summer climates were, at times, not dominated by severe cold.

Vegetation and climate history in the Laptev Sea region (arctic Siberia) during Late Quaternary inferred from pollen records

NASA Astrophysics Data System (ADS)

Andreev, A.; Schirrmeister, L.; Tarasov, P.

2009-04-01

A number of permafrost sections dated by 14C, TL, IRSL, and 230U/Th were analysed for pollen. Pollen spectra suggest that wet grass-sedge tundra habitats dominated during an interstadial c. 200-170 ka ago. The climate was rather wet and cold. The pollen spectra reflect sparser grass-sedge vegetation cover during the Late Saalian stadial, c. 170-130 ka BP. Environmental conditions were much more severe compared with the previous interstadial. Open Poaceae and Artemisia communities dominated at the beginning of the Last Interglacial. Some shrubs (Alnus fruticosa, Salix, Betula nana) grew in more protected and wetter places. Climate was rather warm (similar to modern conditions)during this time. Shrub tundra with Alnus fruticosa and Betula nana s.l. dominated in the area during the Eemian climatic optimum, when summer temperatures were 4-5°C higher than today. Early Weichselian pollen records reflect harsh environmental conditions; sparser vegetation (mostly grass and sedge communities) during this time. Middle Weichselian (Karginsky) Interstadial records with dominance of Cyperaceae and Poaceae with some Artemisia and Salix reflects tundra- and steppe-like associations with willow shrubs dominated the area. The climate was relatively moist and warm. A rather high content of algae colonies in the sediments indicates shallow water habitats (e.g. centres of ice wedge polygons). Dominance of Poaceae, Cyperaceae, Artemisia, and Caryophyllaceae pollen with some other herbs is typical for the 40-32 ka BP (climatic optimum) old sediments when open herb dominated the area. High pollen concentrations reflect that dense grass-sedge dominated vegetation; presence of Salix is also characteristic. The records point to climate amelioration during the Middle Weichselian compared to the Early Weichselian. Climate conditions became colder and drier c. 30-26 ka BP. Pollen spectra reflect that sedge-grass-Artemisia with some Caryophyllaceae and Asteraceae dominated the vegetation. Mostly grass conenoses with some Caryophyllaceae, Asteraceae, Cichoriaceae, Selaginella rupestris predominated during the late Weichselian (Sartan), ca 26-16 ka BP. Climate was very cold and dry. Later, 16-12 ka BP, grass and sedge associations with Caryophyllaceae, Asteraceae, and Cichoriaceae dominated the vegetation. Climate was significantly warmer and moister than during the previous interval. Accumulation of Ice Complex sediments stopped ca 12 ka BP, at the beginning of Allerød. Higher pollen concentration, the presence of willow and birch pollen points to a relatively warm climate between 12 and 11 ka BP reflecting significant climate amelioration. Pollen of shrubs disappeared from the Younger Dryas spectra pointing to the harsher climate. Early Holocene spectra are dominated by alder, birch, Poaceae, and Cyperaceae. Climate reconstruction inferred a temperature substantially warmer than present (up to 12°C). Shrubs gradually disappeared from the area after 7.6 14C ka BP and vegetation cover became similar to modern tundra.

Ethnic differences in the degree of morning blood pressure surge and in its determinants between Japanese and European hypertensive subjects: data from the ARTEMIS study.

PubMed

Hoshide, Satoshi; Kario, Kazuomi; de la Sierra, Alejandro; Bilo, Grzegorz; Schillaci, Giuseppe; Banegas, José Ramón; Gorostidi, Manuel; Segura, Julian; Lombardi, Carolina; Omboni, Stefano; Ruilope, Luis; Mancia, Giuseppe; Parati, Gianfranco

2015-10-01

Morning blood pressure (BP) surge has been reported to be a prognostic factor for cardiovascular events. Its determinants are still poorly defined, however. In particular, it is not clear whether ethnic differences play a role in determining morning surge (MS) size. Aim of our study was to explore whether differences exist in the size of MS between Japanese and Western European hypertensive patients. We included 2887 untreated hypertensive patients (age 62.3±8.8 years) from a European ambulatory BP monitoring database and 811 hypertensive patients from a Japanese database (Jichi Medical School Ambulatory Blood Pressure Monitoring WAVE1, age 72.3±9.8 years) following the same inclusion criteria. Their 24-hour ambulatory BP monitoring recordings were analyzed focusing on MS. Sleep-trough MS was defined as the difference between mean systolic BP during the 2 hours after awakening and mean systolic BP during the 1-hour night period that included the lowest sleep BP level. The sleep-trough MS was higher in Japanese than in European hypertensive patients after adjusting for age and 24-hour mean BP levels (40.1 [95% confidence interval 39.0-41.2] versus 23.0 [22.4-23.5] mm Hg; P<0.001). This difference remained significant after accounting for differences in night-time BP dipping. Age was independently associated with MS in the Japanese database, but not in the European subjects. Our results for the first time show the occurrence of substantial ethnic differences in the degree of MS. These findings may help in understanding the role of ethnic factors in cardiovascular risk assessment and in identifying possible ethnicity-related differences in the most effective measures to be implemented for prevention of BP-related cardiovascular events. © 2015 American Heart Association, Inc.

Transcriptome sequencing dissection of the mechanisms underlying differential cold sensitivity in young and mature leaves of the tea plant (Camellia sinensis).

PubMed

Li, Na-Na; Yue, Chuan; Cao, Hong-Li; Qian, Wen-Jun; Hao, Xin-Yuan; Wang, Yu-Chun; Wang, Lu; Ding, Chang-Qing; Wang, Xin-Chao; Yang, Ya-Jun

The tea plant originated in tropical and subtropical regions and experiences considerable challenges during cold winters and late spring frosts. After short-term chilling stress, young leaves of tea plants exhibit browning, a significant increase in electrolyte leakage and a marked decrease in the maximal photochemical efficiency of photosystem II (F v /F m ) compared with mature leaves. To identify the mechanisms underlying the different chilling tolerance between young and mature leaves of the tea plant, we used Illumina RNA-Seq technology to analyse the transcript expression profiles of young and mature leaves exposed to temperatures of 20 °C, 4 °C, and 0 °C for 4 h. A total of 45.70-72.93 million RNA-Seq raw reads were obtained and then de novo assembled into 228,864 unigenes with an average length of 601 bp and an N50 of 867 bp. In addition, the differentially expressed unigenes were identified via Venn diagram analyses for paired comparisons of young and mature leaves. Functional classifications based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that the up-regulated differentially expressed genes were predominantly related to the cellular component terms of chloroplasts and cell membranes, the biological process term of oxidation-reduction process as well as the pathway terms of glutathione metabolism and photosynthesis, suggesting that these components and pathways may contribute to the cold hardiness of mature leaves. Conversely, the inhibited expression of genes related to cell membranes, carotenoid metabolism, photosynthesis, and ROS detoxification in young leaves under cold conditions might lead to the disintegration of cell membranes and oxidative damage to the photosynthetic apparatus. Further quantitative real-time PCR testing validated the reliability of our RNA-Seq results. This work provides valuable information for understanding the mechanisms underlying the cold susceptibility of young tea plant leaves and for breeding tea cultivars with superior frost resistance via the genetic manipulation of antioxidant enzymes. Copyright © 2018 Elsevier GmbH. All rights reserved.

Blood pressure differences between arms and association of dominant hands with blood pressure differences and carotid atherosclerosis.

PubMed

Maeda, Shinji

2013-06-01

Guidelines for the management of hypertension recommend that blood pressure (BP) should be measured twice at every visit; it should be measured in both arms at the first visit, and the right arm BP or higher BP should be recorded. Manufacturers of home BP monitors tend to design the device for measurement of left arm BP. The arm preferred for BP measurement differs according to the methods recommended by the society and according to the home BP monitors. The BP difference (ΔBP) is calculated by subtracting left arm BP from right arm BP. Here, we aim to first investigate which hand will give the most accurate reading by a sphygmomanometer in daily medical practice. Second, we wish to assess the association of the dominant hand with absolute BP difference (|ΔBP|) of at least 10 mmHg and with early atherosclerotic markers in a subanalysis. We found that 6.4% of outpatients were left handed, and the percentage of individuals with systolic |ΔBP| (|ΔSBP|) and diastolic |ΔBP| (|ΔDBP|) of at least 10 mmHg was 14.4 and 7.2%, respectively. The dominant hand was not significantly associated with |ΔBP| of at least 10 mmHg or early atherosclerotic markers. This study suggests that BP measured in one arm is substitutable with that of the other arm because of a lack of association of |ΔBP| with the dominant hand. However, BP of both arms should be actively measured in new outpatients with moderate fever, lifestyle-related diseases, vascular events, age 65 years and above, and smoking history, all of which are factors potentially associated with |ΔBP| of at least 10 mmHg, regardless of the dominant hand.

Cold Induction of Arabidopsis CBF Genes Involves Multiple ICE (Inducer of CBF Expression) Promoter Elements and a Cold-Regulatory Circuit That Is Desensitized by Low Temperature1

PubMed Central

Zarka, Daniel G.; Vogel, Jonathan T.; Cook, Daniel; Thomashow, Michael F.

2003-01-01

The Arabidopsis CBF1, 2, and 3 genes (also known as DREB1b, c, and a, respectively) encode transcriptional activators that have a central role in cold tolerance. CBF1-3 are rapidly induced upon exposing plants to low temperature, followed by expression of CBF-targeted genes, the CBF regulon, resulting in an increase in plant freezing tolerance. At present, little is known about the cold-sensing mechanism that controls CBF expression. Results presented here indicate that this mechanism does not require a cold shock to bring about the accumulation of CBF transcripts, but instead, absolute temperature is monitored with a greater degree of input, i.e. lower temperature, resulting in a greater output, i.e. higher levels of CBF transcripts. Temperature-shift experiments also indicate that the cold-sensing mechanism becomes desensitized to a given low temperature, such as 4°C, and that resensitization to that temperature requires between 8 and 24 h at warm temperature. Gene fusion experiments identified a 125-bp section of the CBF2 promoter that is sufficient to impart cold-responsive gene expression. Mutational analysis of this cold-responsive region identified two promoter segments that work in concert to impart robust cold-regulated gene expression. These sequences, designated ICEr1 and ICEr2 (induction of CBF expression region 1 or 2), were also shown to stimulate transcription in response to mechanical agitation and the protein synthesis inhibitor, cycloheximide. PMID:14500791

Complete genome sequence of Flavobacterium psychrophilum strain CSF259-93 used to select rainbow trout for increased genetic resistance against bacterial cold water disease

USDA-ARS?s Scientific Manuscript database

The genome sequence of Flavobacterium psychrophilum strain CSF259-93, isolated from rainbow trout (Oncorhynchus mykiss), consists of a single circular genome of 2,900,735 bp and 2,701 predicted open reading frames (ORFs). Strain CSF259-93 has been used to select a line of rainbow trout with increase...

Correlation of Late-Pleistocene Lake-Level Oscillations in Mono Lake, California, with North Atlantic Climate Events

NASA Astrophysics Data System (ADS)

Benson, Larry V.; Lund, Steve P.; Burdett, James W.; Kashgarian, Michaele; Rose, Timothy P.; Smoot, Joseph P.; Schwartz, Martha

1998-01-01

Oxygen-18 ( 18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard-Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to 2000 yr. The youngest lowstand, which occurred between 15,500 and 14,000 14C yr B.P., was nearly synchronous with a desiccation of Owens Lake, California. Paleomagnetic secular variation (PSV) data indicate that three of four persistent lowstands occurred at the same times as Heinrich events H1, H2, and H4. 18O data indicate the two highest lake levels occurred ˜18,000 and ˜13,100 14C yr B.P., corresponding to passages of the mean position of the polar jet stream over the Mono Basin. Extremely low values of total inorganic carbon between 26,000 and 14,000 14C yr B.P. indicate glacial activity, corresponding to a time when summer insolation was much reduced.

Continuous monitoring of blood pressure by analyzing the blood flow sound of arteriovenous fistula in hemodialysis patients.

PubMed

Kamijo, Yuka; Kanda, Eiichiro; Horiuchi, Hayato; Kounoue, Noriyuki; Ono, Keisuke; Maeda, Keizo; Yanai, Akane; Honda, Kazuya; Tsujimoto, Ryuji; Yanagi, Mai; Ishibashi, Yoshitaka; Yoshida, Masayuki

2018-06-01

Patients with end-stage renal disease undergoing hemodialysis (HD) have an elevated risk of cardiovascular disease-related morbidity and mortality. To prevent from such a life-threatening event, the continuous blood pressure (BP) monitoring system may contribute to detect BP decline in early stages and may help to do appropriate disposal. Our research team has introduced an electronic stethoscope (Asahi Kasei Co, Ltd., Tokyo, Japan), which translates sound intensity of Arteriovenous Fistula (AVF) to BP data using the technique of Fourier transformation that can predict continuous BP non-invasively. This study, we investigated whether electronic stethoscope-guided estimated BP (e-BP) would actually reflect systolic BP measured by sphygmomanometer (s-BP), and whether e-BP could predict fall of BP during HD. Twenty-six patients who underwent HD treatment in our hospital were evaluated prospectively. We obtained sound intensity data from the electronic stethoscope which was equipped with the return line of HD. Then, the data were translated into e-BP data to be compared with s-BP. Correlation of total of 315 data sets obtained from each method was examined. An accuracy of diagnosis of intra-dialytic hypotension (IDH) was evaluated. Total of 315 data sets were obtained. A close correlation was observed between e-BP and s-BP (r = 0.887, p < 0.0001). Sensitivity and positive predictive value of predicted-BP for detection of IDH was 90 and 81.3%, respectively. Electronic stethoscope-guided BP measurement would be helpful for real-time diagnosis of BP fall in HD patients. Further investigations are needed.

Wetlands sediment record from the upper Yarlung Tsangpo valley, southwest Tibetan Plateau, reveals mid-Holocene Epipaleolithic human occupation coincident with increased early and mid-Holocene wetness driven by enhanced Indian Monsoon rainfall

NASA Astrophysics Data System (ADS)

Hudson, A. M.; Olsen, J. W.; Quade, J.; Lei, G.; Huth, T.; Zhang, H.; Perreault, C.

2016-12-01

The headwaters of the Yarlung Tsangpo river valley, located in the southwestern Tibetan Plateau, are characterized by a cold and dry climate, but contain abundant river-marginal wetlands environments, which fluctuate in extent in response to changes in local water table elevation. This region receives 80% of precipitation from the Indian Monsoon, which forms the dominant control on moisture availability, and hence wetlands extent. Our paleowetlands record, based on 14C dating of organic-rich paleowetlands deposits, provides a novel record of Holocene monsoon intensity. The wetlands deposits consist of four sedimentary units that indicate decreasing wetlands extent and monsoon intensity since 10.4 ka BP. Wet conditions occurred at ˜10.4 ka BP, ˜9.6 ka BP and ˜7.9-4.8 ka BP, with similar-to-modern conditions from ˜4.6-2.0 ka BP, and drier-than-modern conditions from ˜2.0 ka BP to present. Wetland changes correlate with monsoon intensity changes identified in nearby records, with weak monsoon intervals corresponding to desiccation and erosion of wetlands deposits. Dating of in situ ceramic and microlithic artifacts in wetlands sediments at multiple sites indicates Epipaleolithic human occupation of the YT valley after 6.6 ka BP. Artifact typology study reveals a similar microlithic technology was employed across the high plateau interior, but XRF obsidian provenance reveals separate northeast and southwest lithic conveyance zones. This indicates widespread colonization of the high, arid Tibetan Plateau interior by one or more highly mobile human populations during the early and mid-Holocene, coincident with favorable warm, wet climate conditions.

Late Quaternary vegetation and climate history of the central Bering land bridge from St. Michael Island, western Alaska

USGS Publications Warehouse

Ager, T.A.

2003-01-01

Pollen analysis of a sediment core from Zagoskin Lake on St. Michael Island, northeast Bering Sea, provides a history of vegetation and climate for the central Bering land bridge and adjacent western Alaska for the past ???30,000 14C yr B.P. During the late middle Wisconsin interstadial (???30,000-26,000 14C yr B.P.) vegetation was dominated by graminoid-herb tundra with willows (Salix) and minor dwarf birch (Betula nana) and Ericales. During the late Wisconsin glacial interval (26,000-15,000 14C yr B.P.) vegetation was graminoid-herb tundra with willows, but with fewer dwarf birch and Ericales, and more herb types associated with dry habitats and disturbed soils. Grasses (Poaceae) dominated during the peak of this glacial interval. Graminoid-herb tundra suggests that central Beringia had a cold, arid climate from ???30,000 to 15,000 14C yr B.P. Between 15,000 and 13,000 14C yr B.P., birch shrub-Ericales-sedge-moss tundra began to spread rapidly across the land bridge and Alaska. This major vegetation change suggests moister, warmer summer climates and deeper winter snows. A brief invasion of Populus (poplar, aspen) occurred ca. 11,000-9500 14C yr B.P., overlapping with the Younger Dryas interval of dry, cooler(?) climate. During the latest Wisconsin to middle Holocene the Bering land bridge was flooded by rising seas. Alder shrubs (Alnus crispa) colonized the St. Michael Island area ca. 8000 14C yr B.P. Boreal forests dominated by spruce (Picea) spread from interior Alaska into the eastern Norton Sound area in middle Holocene time, but have not spread as far west as St. Michael Island. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

Holocene South Asian Monsoon Climate Change - Potential Mechanisms and Effects on Past Civilizations

NASA Astrophysics Data System (ADS)

Staubwasser, M.; Sirocko, F.; Grootes, P. M.; Erlenkeuser, H.; Segl, M.

2002-12-01

Planktonic oxygen isotope ratios from the laminated sediment core 63KA off the river Indus delta dated with 80 AMS radiocarbon ages reveal significant climate changes in the south Asian monsoon system throughout the Holocene. The most prominent event of the early-mid Holocene occurred after 8.4 ka BP and is within dating error of the GISP/GRIP event centered at 8.2 ka BP. The late Holocene is generally more variable, and shows non-periodic cycles in the multi-centennial frequency band. The largest change of the entire Holocene occurred at 4.2 ka BP and is concordant with the end of urban Harappan civilization in the Indus valley. Opposing isotopic trends across the northern Arabian Sea surface indicate a reduction in Indus river discharge at that time. Consequently, sustained drought may have initiated the archaeologically recorded interval of southeastward habitat tracking within the Harappan cultural domain. The hemispheric significance of the 4.2 ka BP event is evident from concordant climate change in the eastern Mediterranean and the Middle East. The late Holocene cycles in South Asia, which most likely represent drought cycles, vary between 250 and 800 years and are coherent with the evolution of cosmogenic radiocarbon production rates in the atmosphere. This suggests that solar variability is the fundamental cause behind late Holocene rainfall changes at least over south Asia.

Late Neolithic Mondsee Culture in Austria: living on lakes and living with flood risk?

NASA Astrophysics Data System (ADS)

Swierczynski, T.; Lauterbach, S.; Dulski, P.; Brauer, A.

2013-07-01

Neolithic and Bronze Age lake dwellings in the European Alps became recently protected under the UNESCO World Heritage. However, only little is known about the cultural history of the related pre-historic communities, their adaptation strategies to environmental changes and particularly about the almost synchronous decline of many of these settlements around the transition from the Late Neolithic to the Early Bronze Age. For example, there is an ongoing debate whether the abandonment of Late Neolithic lake dwellings at Lake Mondsee (Upper Austria) was caused by unfavourable climate conditions or a single catastrophic event. Within the varved sediments of Lake Mondsee, we investigated the occurrence of intercalated detrital layers from major floods and debris flows to unravel extreme surface runoff recurrence during the Neolithic settlement period. A combination of detailed sediment microfacies analysis and μXRF element scanning allows distinguishing debris flow and flood deposits. A total of 60 flood and 12 debris flow event layers was detected between 7000 and 4000 varve years (vyr) BP. Compared to the centennial- to millennial-scale average, a period of increased runoff event frequency can be identified between 5900 and 4450 vyr BP. Enhanced flood frequency is accompanied by predominantly siliciclastic sediment supply between ca. 5500 and 5000 vyr BP and enhanced dolomitic sediment supply between 4900 and 4500 vyr BP. A change in the location and the construction technique of the Neolithic lake dwellings at Lake Mondsee can be observed during the period of higher flood frequency. While lake dwellings of the first settlement period (ca. 5800-5250 cal. yr BP) were constructed directly on the wetlands, later constructions (ca. 5400-4700 cal. yr BP) were built on piles upon the water, possibly indicating an adaptation to either increased flood risk or a general increase of the lake level. However, our results also indicate that other than climatic factors (e.g. socio-economic changes) must have influenced the decline of the Mondsee Culture because flood activity generally decreased since 4450 vyr BP, but no new lake dwellings have been established thereafter.

Relationships Between Components of Blood Pressure and Cardiovascular Events in Patients with Stable Coronary Artery Disease and Hypertension.

PubMed

Vidal-Petiot, Emmanuelle; Greenlaw, Nicola; Ford, Ian; Ferrari, Roberto; Fox, Kim M; Tardif, Jean-Claude; Tendera, Michal; Parkhomenko, Alexander; Bhatt, Deepak L; Steg, P Gabriel

2018-01-01

Observational studies have shown a J-shaped relationship between diastolic blood pressure (BP) and cardiovascular events in hypertensive patients with coronary artery disease. We investigated whether the increased risk associated with low diastolic BP reflects elevated pulse pressure (PP). In 22 672 hypertensive patients with coronary artery disease from the CLARIFY registry (Prospective Observational Longitudinal Registry of Patients With Stable Coronary Artery Disease), followed for a median of 5.0 years, BP was measured annually and averaged. The relationships between PP and diastolic BP, alone or combined, and the primary composite outcome (cardiovascular death or myocardial infarction) were analyzed using multivariable Cox proportional hazards models. Adjusted hazard ratios for the primary outcome were 1.62 (95% confidence interval [CI], 1.40-1.87), 1.00 (ref), 1.07 (95% CI, 0.94-1.21), 1.54 (95% CI, 1.32-1.79), and 2.34 (95% CI, 1.95-2.81) for PP<45, 45 to 54 (reference), 55 to 64, 65 to 74, and ≥75 mm Hg, respectively, and 1.50 (95% CI, 1.31-1.72), 1.00 (reference), and 1.58 (95% CI, 1.42-1.77) for diastolic BPs of <70, 70 to 79 (ref), and ≥80 mm Hg, respectively. In a cross-classification analysis between diastolic BP and PP, the relationship between diastolic BP and the primary outcome remained J-shaped when the analysis was restricted to patients with the lowest-risk PP (45-64 mm Hg), with adjusted hazard ratios of 1.53 (95% CI, 1.27-1.83), 1.00 (ref), and 1.54 (95% CI, 1.34-1.75) in the <70, 70 to 79 (reference), and ≥80 mm Hg subgroups, respectively. The J-shaped relationship between diastolic BP and cardiovascular events in hypertensive patients with coronary artery disease persists in patients within the lowest-risk PP range and is therefore unlikely to be solely the consequence of an increased PP reflecting advanced vascular disease. URL: http://www.clarify-registry.com. Unique identifier: ISRCTN43070564. © 2017 American Heart Association, Inc.

Know your limits? Climate extremes impact the range of Scots pine in unexpected places

PubMed Central

Julio Camarero, J.; Gazol, Antonio; Sancho-Benages, Santiago; Sangüesa-Barreda, Gabriel

2015-01-01

Background and Aims Although extreme climatic events such as drought are known to modify forest dynamics by triggering tree dieback, the impact of extreme cold events, especially at the low-latitude margin (‘rear edge’) of species distributional ranges, has received little attention. The aim of this study was to examine the impact of one such extreme cold event on a population of Scots pine (Pinus sylvestris) along the species’ European southern rear-edge range limit and to determine how such events can be incorporated into species distribution models (SDMs). Methods A combination of dendrochronology and field observation was used to quantify how an extreme cold event in 2001 in eastern Spain affected growth, needle loss and mortality of Scots pine. Long-term European climatic data sets were used to contextualize the severity of the 2001 event, and an SDM for Scots pine in Europe was used to predict climatic range limits. Key Results The 2001 winter reached record minimum temperatures (equivalent to the maximum European-wide diurnal ranges) and, for trees already stressed by a preceding dry summer and autumn, this caused dieback and large-scale mortality. Needle loss and mortality were particularly evident in south-facing sites, where post-event recovery was greatly reduced. The SDM predicted European Scots pine distribution mainly on the basis of responses to maximum and minimum monthly temperatures, but in comparison with this the observed effects of the 2001 cold event at the southerly edge of the range limit were unforeseen. Conclusions The results suggest that in order to better forecast how anthropogenic climate change might affect future forest distributions, distribution modelling techniques such as SDMs must incorporate climatic extremes. For Scots pine, this study shows that the effects of cold extremes should be included across the entire distribution margin, including the southern ‘rear edge’, in order to avoid biased predictions based solely on warmer climatic scenarios. PMID:26292992

Cold episodes in the Peruvian Central Andes: Composites, Types, and their Impacts over South America (1958-2014)

NASA Astrophysics Data System (ADS)

Sulca, J. C.; Vuille, M. F.; Roundy, P. E.; Trasmonte, G.; Silva, Y.; Takahashi, K.

2015-12-01

The Mantaro basin (MB) is located in the central Peruvian Andes. Occasionally, cold episodes are observed during austral summer (January-March), that strongly damage crops. However, little is known about the causes and impacts of such cold episodes. The main goal of this study is thus to characterize cold episodes in the MB and assess their large-scale circulation and teleconnections over South America (SA) during austral summer. To identify cold events in the MB daily minimum temperature (Tmin) for the period 1958-2014 from Huayao station, located within the MB was used. A cold episode is defined when daily minimum temperature drops below its 10-percentile for at least one day. Additionally, to study the sensitivity between physical mechanisms associated with cold episodes and temperature, cold episodes are classified in three groups: Weak cold episodes (7.5 ≤ Tmin ≤ 10 percentile), strong cold episodes (Tmin ≤ 2.5 percentile), but excluding the 9 coldest events (Tmin ≤ 0 ͦ C), henceforth referred to as extraordinary cold episodes. Several gridded reanalysis were used to characterize the large-scale circulation, cloud cover and rainfall over SA associated with these events. Weak and strong cold episodes in the MB are mainly associated with a weakening of the Bolivian High-Nordeste Low system by tropical-extratropical interactions. Both types of cold episodes are associated with westerly wind anomalies at mid- and upper-tropospheric levels aloft the Peruvian Central Andes, which inhibit the influx of humid air masses from the lowlands to the east and hence limit the development of cloud cover (e.g., positive OLR anomalies over MB). The resulting clear sky conditions cause nighttime temperatures to drop, leading to cold extremes below 10-percentile. Simultaneously, northeastern Brazil (NEB) registers negative OLR anomalies, strong convection and enhanced cloud cover because displacement of the South Atlantic Convergence Zone (SACZ) toward the northeast of its climatologic position. By contrast, extraordinary cold episodes in the MB are associated with cold and dry polar air advection at all tropospheric levels toward the central Peruvian Andes. On interannual timescales, El Niño may limit the occurrence of all types of cold episodes in the MB through enhanced tropical tropospheric background warming.

The 70 kDa Heat Shock Protein Assists during the Repair of Chilling Injury in the Insect, Pyrrhocoris apterus

PubMed Central

Koštál, Vladimír; Tollarová-Borovanská, Michaela

2009-01-01

Background The Pyrrhocoris apterus (Insecta: Heteroptera) adults attain high levels of cold tolerance during their overwintering diapause. Non-diapause reproducing adults, however, lack the capacity to express a whole array of cold-tolerance adaptations and show relatively low survival when exposed to sub-zero temperatures. We assessed the competence of non-diapause males of P. apterus for responding to heat- and cold-stresses by up-regulation of 70 kDa heat shock proteins (Hsps) and the role of Hsps during repair of heat- and cold-induced injury. Principal Findings The fragments of P. apterus homologues of Hsp70 inducible (PaHsp70) and cognate forms (PaHsc70) were cloned and sequenced. The abundance of mRNA transcripts for the inducible form (qPCR) and corresponding protein (Western blotting) were significantly up-regulated in response to high and low temperature stimuli. In the cognate form, mRNA was slightly up-regulated in response to both stressors but very low or no up-regulation of protein was apparent after heat- or cold-stress, respectively. Injection of 695 bp-long Pahsp70 dsRNA (RNAi) caused drastic suppression of the heat- and cold-stress-induced Pahsp70 mRNA response and the up-regulation of corresponding protein was practically eliminated. Our RNAi predictably prevented recovery from heat shock and, in addition, negatively influenced repair of chilling injuries caused by cold stress. Cold tolerance increased when the insects were first exposed to a mild heat shock, in order to trigger the up-regulation of PaHsp70, and subsequently exposed to cold stress. Conclusion Our results suggest that accumulation of PaHsp70 belongs to a complex cold tolerance adaptation in the insect Pyrrhocoris apterus. PMID:19229329

Impact of outdoor temperature on prewaking morning surge and nocturnal decline in blood pressure in a Japanese population.

PubMed

Murakami, Shougo; Otsuka, Kuniaki; Kono, Tatsuji; Soyama, Akiko; Umeda, Tatsuya; Yamamoto, Naomune; Morita, Hideaki; Yamanaka, Gaku; Kitaura, Yasushi

2011-01-01

Seasonal variations in blood pressure (BP) have often been attributed to meteorological factors, especially changes in outdoor temperature. We evaluated the direct association between meteorological factors and circadian BP variability. Twenty-four-hour ambulatory BP was monitored continuously for 7 days in 158 subjects. Mean awake, asleep, morning (first 2 h after waking) BP, prewaking morning BP surge (morning systolic BP (SBP)-mean SBP during the 2-h period before waking) and nocturnal BP decline were measured each day. We compared BP values for the lowest and highest days with regard to the daily mean outdoor temperature and mean atmospheric pressure. Morning BP and prewaking morning BP surge on the coldest day were significantly higher than those on the warmest day (morning SBP, 136.6 ± 1.6 vs. 133.1 ± 1.5 mm Hg, P = 0.002; morning diastolic BP, 84.4 ± 0.9 vs. 82.6 ± 0.9 mm Hg, P = 0.02; and prewaking morning BP surge, 20.8 ± 1.3 vs. 15.3 ± 1.3 mm Hg, P = 0.0004). The magnitude of nocturnal BP decline on the coldest day was significantly greater than that on the warmest day (15.8 ± 0.7 vs. 13.9 ± 0.7%, P = 0.01). Outdoor temperature is an important determinant of morning BP, prewaking morning BP surge and the magnitude of nocturnal BP decline. These findings may have important implications in management of hypertension and prevention of cardiovascular events.

Explosive eruptive record in the Katmai region, Alaska Peninsula: an overview

USGS Publications Warehouse

Fierstein, Judy

2007-01-01

At least 15 explosive eruptions from the Katmai cluster of volcanoes and another nine from other volcanoes on the Alaska Peninsula are preserved as tephra layers in syn- and post-glacial (Last Glacial Maximum) loess and soil sections in Katmai National Park, AK. About 400 tephra samples from 150 measured sections have been collected between Kaguyak volcano and Mount Martin and from Shelikof Strait to Bristol Bay (∼8,500 km2 ). Five tephra layers are distinctive and widespread enough to be used as marker horizons in the Valley of Ten Thousand Smokes area, and 140 radiocarbon dates on enclosing soils have established a time framework for entire soil–tephra sections to 10 ka; the white rhyolitic ash from the 1912 plinian eruption of Novarupta caps almost all sections. Stratigraphy, distribution and tephra characteristics have been combined with microprobe analyses of glass and Fe– Ti oxide minerals to correlate ash layers with their source vents. Microprobe analyses (typically 20–50 analyses per glass or oxide sample) commonly show oxide compositions to be more definitive than glass in distinguishing one tephra from another; oxides from the Kaguyak caldera-forming event are so compositionally coherent that they have been used as internal standards throughout this study. Other than the Novarupta and Trident eruptions of the last century, the youngest locally derived tephra is associated with emplacement of the Snowy Mountain summit dome (<250 14C years B.P.). East Mageik has erupted most frequently during Holocene time with seven explosive events (9,400 to 2,400 14C years B.P.) preserved as tephra layers. Mount Martin erupted entirely during the Holocene, with lava coulees (>6 ka), two tephras (∼3,700 and ∼2,700 14C years B.P.), and a summit scoria cone with a crater still steaming today. Mount Katmai has three times produced very large explosive plinian to sub-plinian events (in 1912; 12– 16 ka; and 23 ka) and many smaller pyroclastic deposits show that explosive activity has long been common there. Mount Griggs, fumarolically active and moderately productive during postglacial time (mostly andesitic lavas), has three nested summit craters, two of which are on top of a Holocene central cone. Only one ash has been found that is (tentatively) correlated with the most recent eruptive activity on Griggs (<3,460 14C years B.P.). Eruptions from other volcanoes NE and SW beyond the Katmai cluster represented in this area include: (1) coignimbrite ash from Kaguyak’s caldera-forming event (5,800 14C years B.P.); (2) the climactic event from Fisher caldera (∼9,100 14C years B.P.—tentatively correlated); (3) at least three eruptions most likely from Mount Peulik (∼700, ∼7,700 and ∼8,500 14C years B.P.); and (4) a phreatic fallout most likely from the Gas Rocks (∼2,300 14C years B.P.). Most of the radiocarbon dating has been done on loess, soil and peat enclosing this tephra. Ash correlations supported by stratigraphy and microprobe data are combined with radiocarbon dating to show that variably organics-bearing substrates can provide reliable limiting ages for ash layers, especially when data for several sites is available.>(<3,460 14C years B.P.).  Eruptions from other volcanoes NE and SW beyond the Katmai cluster represented in this area include: (1) coignimbrite ash from Kaguyak’s caldera-forming event (5,800 14C years B.P.); (2) the climactic event from Fisher caldera (∼9,100 14C years B.P.—tentatively correlated); (3) at least three eruptions most likely from Mount Peulik (∼700, ∼7,700 and ∼8,500 14C years B.P.); and (4) a phreatic fallout most likely from the Gas Rocks (∼2,300 14C years B.P.). Most of the radiocarbon dating has been done on loess, soil and peat enclosing this tephra. Ash correlations supported by stratigraphy and microprobe data are combined with radiocarbon dating to show that variably organics-bearing substrates can provide reliable limiting ages for ash layers, especially when data for several sites is available.

Safety and Efficacy Profile of Echinacea purpurea to Prevent Common Cold Episodes: A Randomized, Double-Blind, Placebo-Controlled Trial

PubMed Central

Jawad, M.; Schoop, R.; Suter, A.; Klein, P.; Eccles, R.

2012-01-01

Objective. To investigate the safety (risk) and efficacy (benefit) of Echinacea purpurea extract in the prevention of common cold episodes in a large population over a 4-month period. Methods. 755 healthy subjects were allocated to receive either an alcohol extract from freshly harvested E. purpurea (95% herba and 5% root) or placebo. Participants were required to record adverse events and to rate cold-related issues in a diary throughout the investigation period. Nasal secretions were sampled at acute colds and screened for viruses. Results. A total of 293 adverse events occurred with Echinacea and 306 with placebo treatment. Nine and 10% of participants experienced adverse events, which were at least possibly related to the study drug (adverse drug reactions). Thus, the safety of Echinacea was noninferior to placebo. Echinacea reduced the total number of cold episodes, cumulated episode days within the group, and pain-killer medicated episodes. Echinacea inhibited virally confirmed colds and especially prevented enveloped virus infections (P < 0.05). Echinacea showed maximal effects on recurrent infections, and preventive effects increased with therapy compliance and adherence to the protocol. Conclusions. Compliant prophylactic intake of E. purpurea over a 4-month period appeared to provide a positive risk to benefit ratio. PMID:23024696

Vegetation and Water Level Changes for the Northeast U.S. During the "8.2 ka Event"

NASA Astrophysics Data System (ADS)

Newby, P. E.; Donnelly, J. P.; Shuman, B.; MacDonald, D.

2006-12-01

Cool conditions, known as the "8.2 ka event", occurred between 8400 and 7900 cal yr B.P. in Greenland, Europe and elsewhere in the North Atlantic. The impact of this brief cool interval on local forests is recorded in radiocarbon-dated, high-resolution pollen stratigraphies for New Long Pond (41^{0}50'N, 70^{0}42'W) and Davis Pond (42^{0}30'N, 73^{0}19'W), Massachusetts. The vegetation response to the event is recorded differently for regions with contrasting soil types. At New Long Pond, the sandy outwash derived soils are associated with changes in jack/red, white and pitch pine populations, whereas the dominant changes in vegetation for the clay-rich, proglacial lake derived soils around Davis Pond are among oak, hemlock, and beech. At both sites, pollen evidence for the "8.2 ka event" may be easily overlooked within the more dominant regional pattern for the Northeast, which shows a shift from dry to moist conditions in conjunction with changes from predominantly white pine to oak with more mesic plant taxa between 9000 and 8000 cal yr B.P. At New Long Pond, the "8.2 ka event" is brief, preceded by a low-stand in water-level during the early Holocene and dominated by white pine pollen. After 9000 cal yr B.P., pitch pine with beech, maple, hop/hornbeam, elm and ash pollen indicate a mixed mesophytic forest. A radiocarbon-dated decrease in loss-on-ignition values at 8400 cal yr B.P., likely related to a drawdown in lake level, distinguishes the "8.2 event" and helps highlight subtle shifts in vegetation that favor colder and drier conditions than before the event. Following this brief episode, the pollen data indicate a return to warm and moist conditions until about 5600 years ago. At Davis Pond, increased oak and decreased hemlock pollen abundances, followed by an increase in beech pollen abundance is evident and show what may be the dominant regional pollen signature for the "8.2 ka event" in the Northest. This pattern is also recorded at nearby Berry and North Ponds in western Massachusetts. The appearance of ragweed pollen at both Davis and New Long Pond may indicate perturbations to the vegetation that also relate to the "8.2 ka event".

Obstructive sleep apnea syndrome and hypertension: ambulatory blood pressure.

PubMed

Kario, Kazuomi

2009-06-01

Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for hypertension and cardiovascular disease. OSAS is the frequent underlying disease of secondary hypertension and resistant hypertension. OSAS increases both daytime and night-time ambulatory blood pressures through the activation of various neurohumoral factors including the sympathetic nervous system and the renin-angiotensin-aldosterone system. In particular, OSAS predominantly increases ambulatory BP during sleep compared with the awake period, with the result that OSAS is likely to be associated with the non-dipping pattern (diminished nocturnal BP fall) or riser pattern (higher sleep BP than awake BP) of nocturnal BP. An additional characteristic of ABP in OSAS is increased BP variability. The newly developed non-invasive hypoxia-trigger BP-monitoring system detected marked midnight BP surges (ranging from around 10 to 100 mm Hg) during sleep in OSAS patients. The exaggerated BP surge may trigger OSAS-related cardiovascular events occurring during sleep. Clinically, as nocturnal hypoxia is the determinant of morning minus evening BP difference (ME difference), OSAS should be strongly suspected when morning BP cannot be controlled <135/85 mm Hg with increased ME difference even by the specific antihypertensive medications targeting morning hypertension such as bedtime dosing of antihypertensive drugs. Understanding the characteristics of OSAS-related hypertension is essentially important to achieve perfect BP control over a 24-h period, including the sleep period, for more effective prevention of cardiovascular disease.

Potentials and problems of building detailed dust records using peat archives: An example from Store Mosse (the "Great Bog"), Sweden

NASA Astrophysics Data System (ADS)

Kylander, Malin E.; Martínez-Cortizas, Antonio; Bindler, Richard; Greenwood, Sarah L.; Mörth, Carl-Magnus; Rauch, Sebastien

2016-10-01

Mineral dust deposition is a process often overlooked in northern mid-latitudes, despite its potential effects on ecosystems. These areas are often peat-rich, providing ample material for the reconstruction of past changes in atmospheric deposition. The highly organic (up to 99% in some cases) matrix of atmospherically fed mires, however, makes studying the actual dust particles (grain size, mineralogy) challenging. Here we explore some of the potentials and problems of using geochemical data from conservative, lithogenic elements (Al, Ga, Rb, Sc, Y, Zr, Th, Ti and REE) to build detailed dust records by using an example from the 8900-yr peat sequence from Store Mosse (the ;Great Bog;), which is the largest mire complex in the boreo-nemoral region of southern Sweden. The four dust events recorded at this site were elementally distinct, suggesting different dominant mineral hosts. The oldest and longest event (6385-5300 cal yr BP) sees a clear signal of clay input but with increasing contributions of mica, feldspar and middle-REE-rich phosphate minerals over time. These clays are likely transported from a long-distance source (<100 km). While dust deposition was reduced during the second event (5300-4370 cal yr BP), this is the most distinct in terms of its source character with [Eu/Eu∗]UCC revealing the input of plagioclase feldspar from a local source, possibly active during this stormier period. The third (2380-2200 cal yr BP) and fourth (1275-1080 cal yr BP) events are much shorter in duration and the presence of clays and heavy minerals is inferred. Elemental mass accumulation rates reflect these changes in mineralogy where the relative importance of the four dust events varies by element. The broad changes in major mineral hosts, grain size, source location and approximated net dust deposition rates observed in the earlier dust events of longer duration agree well with paleoclimatic changes observed in northern Europe. The two most recent dust events are much shorter in duration, which in combination with evidence of their local and regional character, may explain why they have not been seen elsewhere.

New tree-ring evidence for the Late Glacial period from the northern pre-Alps in eastern Switzerland

NASA Astrophysics Data System (ADS)

Reinig, Frederick; Nievergelt, Daniel; Esper, Jan; Friedrich, Michael; Helle, Gerhard; Hellmann, Lena; Kromer, Bernd; Morganti, Sandro; Pauly, Maren; Sookdeo, Adam; Tegel, Willy; Treydte, Kerstin; Verstege, Anne; Wacker, Lukas; Büntgen, Ulf

2018-04-01

The rate and magnitude of temperature variability at the transition from the Last Glacial Maximum into the early Holocene represents a natural analog to current and predicted climate change. A limited number of high-resolution proxy archives, however, challenges our understanding of environmental conditions during this period. Here, we present combined dendrochronological and radiocarbon evidence from 253 newly discovered subfossil pine stumps from Zurich, Switzerland. The individual trees reveal ages of 41-506 years and were growing between the Allerød and Preboreal (∼13‧900-11‧300 cal BP). Together with previously collected pines from this region, this world's best preserved Late Glacial forest substantially improves the earliest part of the absolutely dated European tree-ring width chronology between 11‧300 and 11‧900 cal BP. Radiocarbon measurements from 65 Zurich pines between ∼12‧320 and 13‧950 cal BP provide a perspective to prolong the continuous European tree-ring record by another ∼2000 years into the Late Glacial era. These data will also be relevant for pinpointing the Laacher See volcanic eruption (∼12‧900 cal BP) and two major Alpine earthquakes (∼13‧770 and ∼11‧600 cal BP). In summary, this study emphasizes the importance of dating precision and multi-proxy comparison to disentangle environmental signals from methodological noise, particularly during periods of high climate variability but low data availability, such as the Younger Dryas cold spell (∼11‧700 and 12‧900 cal BP).

High resolution stable isotopes and elemental analysis on benthic foraminifera: a 4000 yr BP record from the ria de Muros (NW Spain)

NASA Astrophysics Data System (ADS)

Pena, L. D.; Francés, G.; Diz, P.; Nombela, M. A.; Alejo, I.

2003-04-01

Carbon and oxygen stable isotopes and ICP-OES elemental ratio concentrations (Mg/Ca, Sr/Ca, Ba/Ca) from core EUGC-3B (42 45.10'N; 9 02.23'W, at 38 m.b.s.l. and 410 cm length) were measured over monospecific benthic foraminiferal samples (Nonion fabum) ranging over the last 4500 yr BP. From the oldest analysed sample (289 cm) to the core top, stable isotopes signal shows that the whole record can be separated into 4 intervals lasting each of them about 1000 yr. The lowermost interval (4300-3000 yr BP) is characterized by relatively stable delta 18O values (mean 1.77 per mil). Delta 13C is relatively low except for a maximum around 3300 cal BP (-1.50 per mil). An abrupt decrease down to the minimum value in delta 13C (-4.41 per mil) is accomplished in approximately 200 yr. Mg/Ca and Ba/Ca match perfectly this event, both of them showing the respective maxima values. Sr/Ca has a very similar behaviour to that of delta 13C but with smoother fluctuations. We attribute high values of delta 13C, Sr/Ca and Ba/Ca to periods of enhanced coastal productivity, probably due to reinforced upwelling events in the region. According to Mg/Ca signal this reinforcement took place during a relatively warmer period. The most remarkable feature during the two next periods (3000-1900 yr BP and 1900-1000 yr BP) consists of a stepwise increase of delta 13C values punctuated by a sharp decrease at the end of each interval. All the remaining proxies exhibit a nearly constant trend over these intervals. Each period can be interpreted as a weak enhance of marine productivity that the system does not hold up and finally aborts. The most recent interval represents the establishment of current conditions in the coastal system. The most conspicuous event from this interval consists of an abrupt decrease of the delta 18O that lasted for 300 yr. This event could be correlated with the well recognized warm climatic event known as the Medieval Warm Period. However the Mg/Ca ratio does not show high values at this moment. Therefore a salinity decrease caused by enhanced run off can be also invoked to explain low delta 18O values. A hypothetical warmer and wetter period could support both interpretations. Acknowledgements to EU HOLSMEER Project (EVK2-CT-2000-00060) and Paleostudies Program. Contribution 269 of EX-1.

Efficacy and Safety of S-Amlodipine 2.5 and 5 mg/d in Hypertensive Patients Who Were Treatment-Naive or Previously Received Antihypertensive Monotherapy.

PubMed

Şen, Selçuk; Demir, Meral; Yiğit, Zerrin; Üresin, Ali Yağız

2018-07-01

The aim of the present study was to evaluate the efficacy and safety of S-amlodipine 2.5 and 5 mg/d in patients with hypertension who were treatment-naive or previously received antihypertensive monotherapy. During the 8-week treatment period, all patients received S-amlodipine 2.5 mg/d for the first 4 weeks, followed by S-amlodipine 5 mg/d for the second 4 weeks. For efficacy assessments, ambulatory and office blood pressure (BP) measurements were performed during the baseline, fourth-week, and eighth-week visits. For safety assessments, all adverse events and abnormal laboratory findings were recorded. This study is registered with ClinicalTrials.gov (NCT03038451). Of 43 patients evaluated at the screening visit, 33 were enrolled. In the treatment-naive arm, significant reductions in both office and ambulatory systolic BP (SBP) and diastolic BP (DBP) were observed with S-amlodipine 2.5 mg/d and additional significant reductions were achieved with dose titration (S-amlodipine 5 mg/d). At the end of the study, the rate of the treatment-naive patients with BP under control (SBP/DBP <140/90 mm Hg) was 53% with S-amlodipine 2.5 mg and increased to 78% with S-amlodipine 5 mg. For the noninferiority evaluation, S-amlodipine 2.5 and 5 mg/d treatments were generally noninferior to both office and ambulatory BP levels achieved with the medications that the patients received before participating in the study. Five nonserious adverse events likely to be associated with the study drug were observed. No serious adverse event was encountered. Consequently, S-amlodipine can be suggested as an effective and safe treatment option for patients with hypertension.

Altered cropping pattern and cultural continuation with declined prosperity following abrupt and extreme arid event at ~4,200 yrs BP: Evidence from an Indus archaeological site Khirsara, Gujarat, western India.

PubMed

Pokharia, Anil K; Agnihotri, Rajesh; Sharma, Shalini; Bajpai, Sunil; Nath, Jitendra; Kumaran, R N; Negi, Bipin Chandra

2017-01-01

Archaeological sites hold important clues to complex climate-human relationships of the past. Human settlements in the peripheral zone of Indus culture (Gujarat, western India) are of considerable importance in the assessment of past monsoon-human-subsistence-culture relationships and their survival thresholds against climatic stress exerted by abrupt changes. During the mature phase of Harappan culture between ~4,600-3,900yrsBP, the ~4,100±100yrsBP time slice is widely recognized as one of the major, abrupt arid-events imprinted innumerous well-dated palaeo records. However, the veracity of this dry event has not been established from any archaeological site representing the Indus (Harappan) culture, and issues concerning timing, changes in subsistence pattern, and the likely causes of eventual abandonment (collapse) continue to be debated. Here we show a significant change in crop-pattern (from barley-wheat based agriculture to 'drought-resistant' millet-based crops) at ~4,200 yrs BP, based on abundant macrobotanical remains and C isotopes of soil organic matter (δ13CSOM) in an archaeological site at Khirsara, in the Gujarat state of western India. The crop-change appears to be intentional and was likely used as an adaptation measure in response to deteriorated monsoonal conditions. The ceramic and architectural remains of the site indicate that habitation survived and continued after the ~4,200yrsBP dry climatic phase, but with declined economic prosperity. Switching to millet-based crops initially helped inhabitants to avoid immediate collapse due to climatic stresses, but continued aridity and altered cropping pattern led to a decline in prosperity levels of inhabitants and eventual abandonment of the site at the end of the mature Harappan phase.

Asynchronous Glacial Chronologies in the Central Andes (15-40°S) and Paleoclimatic Implications

NASA Astrophysics Data System (ADS)

Zech, R.; Kull, C.; Kubik, P. W.; Veit, H.

2006-12-01

We have established glacial chronologies along a N-S transect over the Central Andes using 10Be surface exposure dating. Our results show that maximum glacial advances occurred asynchronously and reflect the varying influence and shifts of the major atmospheric circulation systems during the Late Quaternary: the tropical circulation in the north and the westerlies in the south. In Bolivia (three research areas in the Cordillera Real and the Cordillera Cochabamba, ~15°S) glacial advances could be dated to ~20 and 12 ka BP. This is in good agreement with published exposure age data from moraines in Bolivia and Peru (provided that all ages are calculated following the same scaling system). Accordingly, the maximum glaciation there probably occurred roughly synchronous to the temperature minimum of the global Last Glacial Maximum (LGM) and the lateglacial cold reversals. Strict correlation with neither the Younger Dryas in the northern hemisphere, nor the Antarctic Cold Reversal is possible due to the current systematic exposure age uncertainties (~10%). Glacier-Climate-Modelling corroborates the sensitivity of the reconstructed glaciers to temperature changes, rather than precipitation. On the contrary, there is good evidence for the dominant role of precipitation changes on the glacial chronologies in the lee of the Cordillera Occidental, i.e. on the Altiplano and further south. The pronounced lateglacial wet phase, which is well documented in lake transgression phases as far south as 28°S (-> tropical moisture source), seems to have caused glacial advances even at ~30°S. In two research areas in Chile at that latitude, we were able to date several lateglacial moraines. Besides, the maximum datable glaciation there occurred at ~30 ka BP. That is significantly earlier than the LGM (sensu strictu) and points to favourable climate conditions for glaciation at that time (particularly increased precipitation). We conclude that the westerlies were more intensive or shifted northward at ~30 ka BP. We have not yet been able to date LGM moraines as far south as ~40°, which would indicate the transition of precipitation- to temperature-sensitive glaciers. Instead, our preliminary exposure age chronology from Valle Rucachoroi (~39°S, Argentina) suggests that the maximum glaciation there occurred also at ~30 ka BP, but that the valleys became ice-free only by ~15 ka BP. Samples from moraines in the cirques are currently in progress and may document lateglacial re-advances.

Holocene Vegetation Changes in Eastern Kamchatka Based on Pollen and Macrofossil Records

NASA Astrophysics Data System (ADS)

Dirksen, V.

2004-12-01

Little is known about the Quaternary climate and vegetation history of Kamchatka. Only a few previous studies have provided paleoenvironmental information for this area, but these studies have poor age control and are inconsistent To reconstruct paleoclimate and both regional and local vegetation history we are analyzing continuous, high-resolution pollen and macrofossil records from peats on Kamchatka. Thin, well-dated ash layers in these peats provide excellent age control; sections sampled thus far range in age back to 12,000 years. Herein we report results from one example, the Uka peat section (57.8oN 162.2oE; about 10 m a.s.l.). This section is located on a morainal terrace close to a small lake. The basal section is lacustrine clay with a few spores pointing to scarce vegetation under cold conditions, probably latest Pleistocene. This clay is replaced upward by limnic peat, probably early Holocene (pollen zone 1). This zone is characterized by dominance of shrub alder and birch, herbs, and ferns. The highest value (in the whole section) of sage and the absence of tree pollen suggest a treeless landscape and thin vegetation cover under still cold conditions, while increase in local aquatic pollen indicates lake filling and shrinking. In Zone 2 (ca. 8000-4000 BP), mire vegetation shows successive development of eutrophic fen including three pulses of sphagnum followed by sedge peaks. Pollen concentration is very low, probably indicating high deposition rates. A warming trend is suggested by the appearance ca. 5600 BP of tree birch, increasing to the end of zone 2, while alder strongly decreases. The most pronounced changes in both regional and local vegetation are found ca. 3800 BP, when tree birch pollen reaches its highest value and a few long-transported spruce pollen grains appear. The dominant (eutrophic) sedge is suddenly replaced by a more oligotrophic one. Such local components as grasses, shrub birch and willow increase, and total pollen concentration dramatically increases. All these features suggest drier conditions in zone 3 (3800-1200 BP), however it should be supported by further studies. Zone 4 (1200 BP to present) shows development of an oligotrophic peat bog indicated by high values of heath; the establishment of shrub pine is signaled by a sharp increase in its pollen.

Historic cycles of fragmentation and expansion in Parnassius smintheus (papilionidae) inferred using mitochondrial DNA.

PubMed

DeChaine, Eric G; Martini, Andrew P

2004-01-01

Climate oscillations of the Quaternary drove the repeated expansion and contraction of ecosystems. Alpine organisms were probably isolated in sky island refugia during warm interglacials, such as now, and expanded their range by migrating down-slope during glacial periods. We used population genetic and phylogenetic approaches to infer how paleoclimatic events influenced the distribution of genetic variation in the predominantly alpine butterfly Parnassius smintheus. We sequenced a 789 bp region of cytochrome oxidase I for 385 individuals from 20 locations throughout the Rocky Mountains, ranging from southern Colorado to northern Montana. Analyses revealed at lease two centers of diversity in the northern and southern Rocky Mountains and strong population structure. Nested clade analysis suggested that the species experienced repeated cycles of population expansion and fragmentation. The estimated ages of these events, assuming a molecular clock, corresponded with paleoclimatic data on habitat expansion and contraction over the past 400,000 years. We propose that alpine butterflies persisted in an archipelago of isolated sky islands during interglacials and that populations expanded and became more connected during cold glacial periods. An archipelago model implies that the effects of genetic drift and selection varied among populations, depending on their latitude, area, and local environment. Alpine organisms are sensitive indicators of climate change and their history can be used to predict how high-elevation ecosystems might respond to further climate warming.

Formation of the southern Bay of Bengal cold pool

NASA Astrophysics Data System (ADS)

Das, Umasankar; Vinayachandran, P. N.; Behara, Ambica

2016-09-01

A pool of relatively cooler water, called here as the southern Bay of Bengal cold pool, exists around Sri Lanka and southern tip of India during the summer monsoon. This cold pool is enveloped by the larger Indian Ocean warm pool and is believed to affect the intraseasonal variations of summer monsoon rainfall. In this study, we have investigated the mechanisms responsible for the formation of the cold pool using a combination of both satellite data sets and a general circulation model of the Indian Ocean. Sea surface temperature (SST) within the cold pool, after the steady increase during the February-April period, decreases first during a pre-monsoon spell in April and then with the monsoon onset during May. The onset cooling is stronger (~1.8°C) than the pre-monsoon cooling (~0.8°C) and culminates in the formation of the cold pool. Analysis of the model temperature equation shows that SST decrease during both events is primarily due to a decrease in incoming solar radiation and an increase in latent heat loss. These changes in the net heat flux are brought about by the arrival of cloud bands above the cold pool during both periods. During the pre-monsoon period, a cloud band originates in the western equatorial Indian Ocean and subsequently arrives above the cold pool. Similarly, during the monsoon onset, a band of clouds originating in the eastern equatorial Indian Ocean comes over the cold pool region. A lead-lag correlation calculation between daily SST and rainfall anomalies suggest that cooling in SST occurs in response to rainfall events with a lag of 5 days. These sequence of events occur every year with certain amount of interannual variability.

Efficacy and safety of LCZ696, a first-in-class angiotensin receptor neprilysin inhibitor, in Asian patients with hypertension: a randomized, double-blind, placebo-controlled study.

PubMed

Kario, Kazuomi; Sun, Ningling; Chiang, Fu-Tien; Supasyndh, Ouppatham; Baek, Sang Hong; Inubushi-Molessa, Akiko; Zhang, Ying; Gotou, Hiromi; Lefkowitz, Martin; Zhang, Jack

2014-04-01

LCZ696 (Japanese adopted name: sucabitril valsartan sodium hydrate), a first-in-class angiotensin receptor neprilysin inhibitor, concomitantly inhibits neprilysin and blocks angiotensin type 1 receptor. This randomized, double-blind, placebo-controlled study, the first in Asia for this drug, evaluated the dose-related efficacy and safety of LCZ696 in patients with hypertension using 24-hour ambulatory blood pressure (BP) monitoring. Asian patients aged ≥18 years (n=389) with hypertension were randomized to receive LCZ696 100 mg (n=100), 200 mg (n=101), 400 mg (n=96), or placebo (n=92) for 8 weeks. The primary end point was mean difference across the 3 single-dose pairwise comparisons of LCZ696 versus placebo in clinic diastolic BP after 8-week treatment. Key secondary efficacy variables included changes in clinic systolic BP and pulse pressure and changes in 24-hour, daytime, and nighttime ambulatory BPs and pulse pressure. Safety assessments included recording all adverse events and serious adverse events. A total of 362 patients completed the study. Reductions in clinic systolic BP, diastolic BP (P<0.0001), and pulse pressure (P<0.001) were significantly greater with all doses of LCZ696 than with placebo. There were also significant reductions in 24-hour, daytime, and nighttime ambulatory systolic BP, diastolic BP, and pulse pressure for all doses of LCZ696 compared with placebo (P<0.0001). LCZ696 was well tolerated, and no cases of angioedema were reported. In conclusion, LCZ696 is effective for the treatment of hypertension in Asian population and, in general, is safe and well tolerated. Clinical Trial Information- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01193101.

Temperature inversions and cold-air pools study in Picos de Europa surroundings

NASA Astrophysics Data System (ADS)

Iglesias González, Miguel; Yagüe, Carlos; Maqueda, Gregorio

2017-04-01

Using surface temperature data from dataloggers located at the bottom of four different high-altitude (2000 m MSL) glaciokarstic depressions in Picos de Europa (Cantabrian Cordillera, Spain) from January 2012 to September 2016, we have analyzed the evolution of more than 200 different cold-air pools events according to different geomorphologic parameters. The ski-view determinates the cold-air pool occurrence and the temperature range, and the depression's depth is a very important factor in the permanent cold-air pools (PCAP) formation. Depending on the structure of the thermal curve, we classified all cold-air pools in each depression by using a conceptual model with eight different modes. With wind and relative humidity data, supplied by a weather station situated near the depressions, and NCAR-NCEP reanalysis data, we have characterized them at mesoscale and synoptic scale. If the ski-view is small enough, we can have undisturbed cold-air pools even though disturbed wind conditions. Snow-covered and non-snow-covered events were measured during the campaign, which allow us to recognize its influence on the temperature inversions. We also identified and analyze several permanent cold-air pools events where December minimum temperature record of -30,6°C in the Iberian Peninsula was measured. We also make a deep analyze of the Iberian Peninsula historical minimal temperature record of -32,7°C, which was measured on February 2016. Finally we use and test a simplified three-layer radiative model to describe and verify the influence of different geomorphologic factors in the cooling process of all the cold-air pools.

16-year Climatology of Cold-Season Extreme Precipitation-Drought Statistics derived from NLDAS Precipitation Data Over the Conterminous U.S.

NASA Astrophysics Data System (ADS)

Matsui, T.; Mocko, D. M.

2015-12-01

We examine radar-gauge merged 1/8-degree hourly precipitation data from the North American Land Data Assimilation System (NLDAS) Phase-II datasets from 1997 to 2013. For each 1/8 grid, we derived statistics of single-event storm duration, total accumulated precipitation, and dry period between each storm events during cold (Oct-Mar) seasons, and histogram of event-by-event statistics are used to estimate the thresholds for extreme (below-1%) and very extreme (below-0.1%) events. In this way, we constructed unique climatology maps of the extreme precipitation-drought frequencies and probability density functions. This climatology map depicted that cold-season extremely heavy precipitation events are populated over West Coast, Deep South, and coastal zone of North East, suggesting impacts of land-falling maritime storm systems. Simultaneously, datasets depicts that long-extended precipitation events are mostly populated over North West, and lower Mississippi Basin up to North East centered at Appalachian Mountains, resembling east Pacific storm tracks and nor'easter storm tracks, respectively. Furthermore, season-by-season statistics of these extreme events were examined for each National Climate Assessment (NCA) regimes in comparison with a number of major atmospheric oscillations and teleconnection patterns as well as Arctic Amplifications. Index of Arctic Amplification includes variability of 500mb zonal wind speed and pole-to-midlatitude differences in atmospheric thickness, linking to the phase speed of the Rossby wave. Finally, we present ensemble correlations scores, and discuss the physical processes and underlying mechanisms for their key characteristics as well as the predictive skill and predictability of the extreme events from sub-seasonal to interannual scales during cold seasons.

Early modern human settlement of Europe north of the Alps occurred 43,500 years ago in a cold steppe-type environment

PubMed Central

Nigst, Philip R.; Haesaerts, Paul; Damblon, Freddy; Frank-Fellner, Christa; Mallol, Carolina; Viola, Bence; Götzinger, Michael; Niven, Laura; Trnka, Gerhard; Hublin, Jean-Jacques

2014-01-01

The first settlement of Europe by modern humans is thought to have occurred between 50,000 and 40,000 calendar years ago (cal B.P.). In Europe, modern human remains of this time period are scarce and often are not associated with archaeology or originate from old excavations with no contextual information. Hence, the behavior of the first modern humans in Europe is still unknown. Aurignacian assemblages—demonstrably made by modern humans—are commonly used as proxies for the presence of fully behaviorally and anatomically modern humans. The site of Willendorf II (Austria) is well known for its Early Upper Paleolithic horizons, which are among the oldest in Europe. However, their age and attribution to the Aurignacian remain an issue of debate. Here, we show that archaeological horizon 3 (AH 3) consists of faunal remains and Early Aurignacian lithic artifacts. By using stratigraphic, paleoenvironmental, and chronological data, AH 3 is ascribed to the onset of Greenland Interstadial 11, around 43,500 cal B.P., and thus is older than any other Aurignacian assemblage. Furthermore, the AH 3 assemblage overlaps with the latest directly radiocarbon-dated Neanderthal remains, suggesting that Neanderthal and modern human presence overlapped in Europe for some millennia, possibly at rather close geographical range. Most importantly, for the first time to our knowledge, we have a high-resolution environmental context for an Early Aurignacian site in Central Europe, demonstrating an early appearance of behaviorally modern humans in a medium-cold steppe-type environment with some boreal trees along valleys around 43,500 cal B.P. PMID:25246543

Late Quaternary palaeoecological and palaeoclimatological reconstruction in the Gutaiului Mountains, northwest Romania

NASA Astrophysics Data System (ADS)

Feurdean, Angelica; Bennike, Ole

2004-12-01

Macrofossil, pollen, lithostratigraphy, mineral magnetic measurements (SIRM and magnetic susceptibility), loss-on-ignition, and AMS radiocarbon dating on sediments from two former crater lakes, situated at moderate altitudes in the Gutaiului Mountains of northwest Romania, allow reconstruction of Late Quaternary climate and environment. Shrubs and herbs with steppe and montane affinities along with stands of Betula and Pinus, colonised the surroundings of the sites prior to 14 700 cal. yr BP and the inferred climatic conditions were cold and dry. The gradual transition to open Pinus-Betula forests, slightly higher lake water temperatures, and higher lake productivity, indicate more stable environmental conditions between 14 700 and 14 100 cal. yr BP. This development was interrupted by cooler and drier climatic conditions between 14 100 and 13 800 cal. yr BP, as inferred from a reduction of open forests to patches, or stands, of Pinus, Betula, Larix, Salix and Populus. The expansion of a denser boreal forest, dominated by Picea, but including Pinus, Larix, Betula, Salix, and Ulmus started at 13 800 cal. yr BP, although the forest density seems to have been reduced between 13400 and 13200cal.yrBP. Air temperature and moisture availability gradually increased, but a change towards drier conditions is seen at 13400cal.yrBP. A distinct decrease in temperature and humidity between 12900 and 11500cal.yrBP led to a return of open vegetation, with patches of Betula, Larix, Salix, Pinus and Alnus and individuals of Picea. Macrofossils and pollen of aquatic plants indicate rising lake water temperatures and increased aquatic productivity already by ca. 11800cal.yrBP, 300 years earlier than documented by the terrestrial plant communities. At the onset of the Holocene, 11500cal.yrBP, forests dominated by Betula, Pinus and Larix expanded and were followed by dense Ulmus forests with Picea, Betula and Pinus at 11250cal.yrBP. Larix pollen was not found, but macrofossil evidence indicates that Larix was an important forest constituent at the onset of the Holocene. Moister conditions were followed by a dry period starting about 10600cal.yrBP, which was more pronounced between 8600 and 8200cal.yrBP, as inferred from aquatic macrofossils. The maximum expansion of Tilia, Quercus, Fraxinus and Acer between 10700 and 8600cal.yrBP may reflect a more continental climate. A drier and/or cooler climate could have been responsible for the late expansion (10300cal.yrBP) and late maximum (9300cal.yrBP) of Corylus. Increased water stress, and possibly cooler conditions around 8600cal.yrBP, may have caused a reduction of Ulmus, Tilia, Quercus and Fraxinus. After 8200cal.yrBP moisture increased and the forests included Picea, Tilia, Quercus and Fraxinus. Copyright

Cold thermal injury from cold caps used for the prevention of chemotherapy-induced alopecia.

PubMed

Belum, Viswanath Reddy; de Barros Silva, Giselle; Laloni, Mariana Tosello; Ciccolini, Kathryn; Goldfarb, Shari B; Norton, Larry; Sklarin, Nancy T; Lacouture, Mario E

2016-06-01

The use of scalp cooling for the prevention of chemotherapy-induced alopecia (CIA) is increasing. Cold caps are placed onto the hair-bearing areas of the scalp for varying time periods before, during, and after cytotoxic chemotherapy. Although not yet reported, improper application procedures could result in adverse events (AEs). At present, there are no evidence-based scalp cooling protocols, and there is no regulatory oversight of their use. To report the occurrence of cold thermal injury (frostbite) on the scalp, following the use of cold caps for the prevention of CIA. We identified four patients who developed cold thermal injuries on the scalp following the application of cold caps. Medical records were analyzed to retrieve the demographic and clinical characteristics. The cold thermal injuries in our patients were grade 1/2 in severity and improved with topical interventions and interruption of cold cap use, although grade 1 persistent alopecia ensued in 3 patients. The true incidence of such injuries in this setting, however, remains unknown. Cold thermal injuries are likely infrequent and preventable AEs that may result from improper device application procedures during cold cap use. Although these untoward events are usually mild to moderate in severity, the potential occurrence of long-term sequelae (e.g., permanent alopecia and scarring) or the need to discontinue cold cap use, are not known. Prospective studies are needed to further elucidate the risk and standardize healthcare delivery methods, and to improve patient/supportive/healthcare provider education.

AMS applications to the paleoclimate changing study in China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, K.; Chen, T.M.; Yuan, D.X.

1995-12-01

To study the paleoclimates changing in China, a high-resolution AMS radio-carbon dating of a loess profile at Weinan, Shaanxi Province, has been carried out and an age of 10,300 BP has been assigned to be the beginning of the HOLOCENE in the studied areas. In the south of China, a stalagmite of 1.2-m high taken from Panlong-dong cave, Guilin, Guangxi Province, has also been studied. The dating with micro-stratification sampling shows that the climate in HOLOCENE was generally damp and warm, but there was a short cola period during 10-11 Ka BP. The resolution of AMS carbon dating of stalagmitemore » is 100 years for the warm and damp period and 500 years for the dry and cold period.« less

Gender differences in the implementation of cardiovascular prevention measures after an acute coronary event.

PubMed

Dallongevillle, Jean; De Bacquer, Dirk; Heidrich, Jan; De Backer, Guy; Prugger, Christoph; Kotseva, Kornelia; Montaye, Michèle; Amouyel, Philippe

2010-11-01

To compare gender-related lifestyle changes and risk factor management after hospitalisation for a coronary event or revascularisation intervention in Europe. The EUROASPIRE III survey was carried out in 22 European countries in 2006-2007. Consecutive patients having had a coronary event or revascularisation before the age of 80 were identified. A total of 8966 patients (25.3% women) were interviewed and underwent clinical and biochemical tests at least 6 months after hospital admission. Trends in cardiovascular risk management were assessed on the basis of the 1994-1995, 1999-2000 and 2006-2007 EUROASPIRE surveys. Female survey participants were generally older and had a lower educational level than male participants (p<0.0001). The prevalences of obesity (p<0.0001), high blood pressure (BP) (p=0.001), elevated low-density lipoprotein (LDL)-cholesterol (p<0.0001) and diabetes (p<0.0001) were significantly higher in women than in men, whereas current smoking (p<0.0001) was significantly more common in men. The use of antihypertensive and antidiabetic drugs (but not that of other drugs) was more common in women than in men. However, BP (p<0.0001), LDL-cholesterol (p<0.0001) and HbA1c (p<0.0001) targets were less often achieved in women than in men. Between 1994 and 2007, cholesterol control improved less in women than in men (interaction: p=0.009), whereas trends in BP control (p=0.32) and glycaemia (p=0.36) were similar for both genders. The EUROASPIRE III results show that despite similarities in medication exposure, women are less likely than men to achieve BP, LDL-cholesterol and HbA1c targets after a coronary event. This gap did not appear to narrow between 1994 and 2007.

Short sleep duration as an independent predictor of cardiovascular events in Japanese patients with hypertension.

PubMed

Eguchi, Kazuo; Pickering, Thomas G; Schwartz, Joseph E; Hoshide, Satoshi; Ishikawa, Joji; Ishikawa, Shizukiyo; Shimada, Kazuyuki; Kario, Kazuomi

2008-11-10

It is not known whether short duration of sleep is a predictor of future cardiovascular events in patients with hypertension. To test the hypothesis that short duration of sleep is independently associated with incident cardiovascular diseases (CVD), we performed ambulatory blood pressure (BP) monitoring in 1255 subjects with hypertension (mean [SD] age, 70.4 [9.9] years) and followed them for a mean period of 50 (23) months. Short sleep duration was defined as less than 7.5 hours (20th percentile). Multivariable Cox hazard models predicting CVD events were used to estimate the adjusted hazard ratio and 95% confidence interval (CI) for short sleep duration. A riser pattern was defined when mean nighttime systolic BP exceeded daytime systolic BP. The end point was a cardiovascular event: stroke, fatal or nonfatal myocardial infarction (MI), and sudden cardiac death. In multivariable analyses, short duration of sleep (<7.5 hours) was associated with incident CVD (hazard ratio [HR], 1.68; 95% CI, 1.06-2.66; P = .03). A synergistic interaction was observed between short sleep duration and the riser pattern (P = .09). When subjects were classified according to their sleep time and a riser vs nonriser pattern, the group with shorter sleep duration plus the riser pattern had a substantially and significantly higher incidence of CVD than the group with predominant normal sleep duration plus the nonriser pattern (HR, 4.43; 95% CI, 2.09-9.39; P < .001), independent of covariates. Short duration of sleep is associated with incident CVD risk and the combination of the riser pattern and short duration of sleep that is most strongly predictive of future CVD, independent of ambulatory BP levels. Physicians should inquire about sleep duration in the risk assessment of patients with hypertension.

Real alerts and artifact classification in archived multi-signal vital sign monitoring data: implications for mining big data.

PubMed

Hravnak, Marilyn; Chen, Lujie; Dubrawski, Artur; Bose, Eliezer; Clermont, Gilles; Pinsky, Michael R

2016-12-01

Huge hospital information system databases can be mined for knowledge discovery and decision support, but artifact in stored non-invasive vital sign (VS) high-frequency data streams limits its use. We used machine-learning (ML) algorithms trained on expert-labeled VS data streams to automatically classify VS alerts as real or artifact, thereby "cleaning" such data for future modeling. 634 admissions to a step-down unit had recorded continuous noninvasive VS monitoring data [heart rate (HR), respiratory rate (RR), peripheral arterial oxygen saturation (SpO 2 ) at 1/20 Hz, and noninvasive oscillometric blood pressure (BP)]. Time data were across stability thresholds defined VS event epochs. Data were divided Block 1 as the ML training/cross-validation set and Block 2 the test set. Expert clinicians annotated Block 1 events as perceived real or artifact. After feature extraction, ML algorithms were trained to create and validate models automatically classifying events as real or artifact. The models were then tested on Block 2. Block 1 yielded 812 VS events, with 214 (26 %) judged by experts as artifact (RR 43 %, SpO 2 40 %, BP 15 %, HR 2 %). ML algorithms applied to the Block 1 training/cross-validation set (tenfold cross-validation) gave area under the curve (AUC) scores of 0.97 RR, 0.91 BP and 0.76 SpO 2 . Performance when applied to Block 2 test data was AUC 0.94 RR, 0.84 BP and 0.72 SpO 2 . ML-defined algorithms applied to archived multi-signal continuous VS monitoring data allowed accurate automated classification of VS alerts as real or artifact, and could support data mining for future model building.

Real Alerts and Artifact Classification in Archived Multi-signal Vital Sign Monitoring Data—Implications for Mining Big Data — Implications for Mining Big Data

PubMed Central

Hravnak, Marilyn; Chen, Lujie; Dubrawski, Artur; Bose, Eliezer; Clermont, Gilles; Pinsky, Michael R.

2015-01-01

PURPOSE Huge hospital information system databases can be mined for knowledge discovery and decision support, but artifact in stored non-invasive vital sign (VS) high-frequency data streams limits its use. We used machine-learning (ML) algorithms trained on expert-labeled VS data streams to automatically classify VS alerts as real or artifact, thereby “cleaning” such data for future modeling. METHODS 634 admissions to a step-down unit had recorded continuous noninvasive VS monitoring data (heart rate [HR], respiratory rate [RR], peripheral arterial oxygen saturation [SpO2] at 1/20Hz., and noninvasive oscillometric blood pressure [BP]) Time data were across stability thresholds defined VS event epochs. Data were divided Block 1 as the ML training/cross-validation set and Block 2 the test set. Expert clinicians annotated Block 1 events as perceived real or artifact. After feature extraction, ML algorithms were trained to create and validate models automatically classifying events as real or artifact. The models were then tested on Block 2. RESULTS Block 1 yielded 812 VS events, with 214 (26%) judged by experts as artifact (RR 43%, SpO2 40%, BP 15%, HR 2%). ML algorithms applied to the Block 1 training/cross-validation set (10-fold cross-validation) gave area under the curve (AUC) scores of 0.97 RR, 0.91 BP and 0.76 SpO2. Performance when applied to Block 2 test data was AUC 0.94 RR, 0.84 BP and 0.72 SpO2). CONCLUSIONS ML-defined algorithms applied to archived multi-signal continuous VS monitoring data allowed accurate automated classification of VS alerts as real or artifact, and could support data mining for future model building. PMID:26438655

Predictability of the European heat and cold waves

NASA Astrophysics Data System (ADS)

Lavaysse, Christophe; Naumann, Gustavo; Alfieri, Lorenzo; Salamon, Peter; Vogt, Jürgen

2018-06-01

Heat and cold waves may have considerable human and economic impacts in Europe. Recent events, like the heat waves observed in France in 2003 and Russia in 2010, illustrated the major consequences to be expected. Reliable Early Warning Systems for extreme temperatures would, therefore, be of high value for decision makers. However, they require a clear definition and robust forecasts of these events. This study analyzes the predictability of heat and cold waves over Europe, defined as at least three consecutive days of {T}_{min} and {T}_{max} above the quantile Q90 (under Q10), using the extended ensemble system of ECMWF. The results show significant predictability for events within a 2-week lead time, but with a strong decrease of the predictability during the first week of forecasts (from 80 to 40% of observed events correctly forecasted). The scores show a higher predictive skill for the cold waves (in winter) than for the heat waves (in summer). The uncertainties and the sensitivities of the predictability are discussed on the basis of tests conducted with different spatial and temporal resolutions. Results demonstrate the negligible effect of the temporal resolution (very few errors due to bad timing of the forecasts), and a better predictability of large-scale events. The onset and the end of the waves are slightly less predictable with an average of about 35% (30%) of observed heat (cold) waves onsets or ends correctly forecasted with a 5-day lead time. Finally, the forecasted intensities show a correlation of about 0.65 with those observed, revealing the challenge to predict this important characteristic.

The timing, two-pulsed nature, and variable climatic expression of the 4.2 ka event: A review and new high-resolution stalagmite data from Namibia

NASA Astrophysics Data System (ADS)

Railsback, L. Bruce; Liang, Fuyuan; Brook, G. A.; Voarintsoa, Ny Riavo G.; Sletten, Hillary R.; Marais, Eugene; Hardt, Ben; Cheng, Hai; Edwards, R. Lawrence

2018-04-01

The climatic event between 4.2 and 3.9 ka BP known as the "4.2 ka event" is commonly considered to be a synchronous global drought that happened as one pulse. However, careful comparison of records from around the world shows that synchrony is possible only if the published chronologies of the various records are shifted to the extent allowed by the uncertainties of their age data, that several records suggest a two-pulsed event, and that some records suggest a wet rather than dry event. The radiometric ages constraining those records have uncertainties of several decades if not hundreds of years, and in some records the event is represented by only one or two analyses. This paper reports a new record from Stalagmite DP1 from northeastern Namibia in which high 230Th/232Th activity ratios allow small age uncertainties ranging between only 10-28 years, and the event is documented by more than 35 isotopic analyses and by petrographic observation of a surface of dissolution. The ages from Stalagmite DP1 combine with results from 11 other records from around the world to suggest an event centered at about 4.07 ka BP with bracketing ages of 4.15 to 3.93 ka BP. The isotopic and petrographic results suggest a two-pulsed wet event in northeastern Namibia, which is in the Southern Hemisphere's summer rainfall zone where more rain presumably fell with southward migration of the Inter-Tropical Convergence Zone as the result of cooling in the Northern Hemisphere. Comparison with other records from outside the region of dryness from the Mediterranean to eastern Asia suggests that multiple climatic zones similarly moved southward during the event, in some cases bringing wetter conditions that contradict the notion of global drought.

Beringian Megafaunal Extinctions at ~37 ka B.P.: Do Micrometeorites Embedded in Fossil Tusks and Skulls Indicate an Extraterrestial Precursor to the Younger Dryas Event?

NASA Astrophysics Data System (ADS)

Hagstrum, J. T.; Firestone, R. B.; West, A.

2009-12-01

Studies of Late Pleistocene megafaunal fossils and their ancient DNA from Beringia (eastern Siberia, Alaska, and the emerged Bering Strait) indicate sharp declines in steppe bison population diversity and horse body size, extinction of the Alaskan wild ass, and local extinctions of brown bear and woolly mammoth genetic lines beginning at about 37 ka B.P. Beringia is also well known for its remarkably preserved Late Pleistocene frozen animal mummies. 14C ages of these mummies are bimodally distributed, having peaks coincident with the earlier ~37 ka B.P., and ~13 ka B.P. Younger Dryas, onset extinction events. Associated with the ~37 ka B.P. event are, for example, the Berezovka mammoth, headless Selerikan horse, steppe bison “Blue Babe”, and baby mammoths “Dima” and “Lyuba”. Analyses of these and other mummies indicate that they died instantly, in mostly healthy condition, with gut contents and high fat reserves indicative of a late summer to autumn season. An assortment of uneaten limbs and other body parts from a variety of species have also been found. Uniformitarian death scenarios inadequately account for the lack of evidence of normal predation and scavenging. Extensive internal injuries (e.g. large bone fractures, hemorrhaging) and apparent rapid burial of the mummies also indicate that something truly unusual happened at the time of these extinction events. We have discovered what appear to be micrometeorites embedded in seven Alaskan mammoth tusks and a Siberian bison skull acquired from commercial sources. 14C ages for five of these fossils have a weighted mean age of 33 ± 2 ka B.P. Laser ablation ICP-MS and XRF analyses of the particles indicate high Fe contents with compositions enriched in Ni and depleted in Ti, similar to Fe meteorites and unlike any natural terrestrial sources. Microprobe analyses of a Fe-Ni sulfide grain from tusk 2 also show that it contains between 3 and 20 weight percent Ni. SEM images and XRF analyses of a bison skull fragment show sharp-edged channels (~0.1 mm across) containing Fe sulfide material with botryoidal texture that appears to have cooled from a molten state. Multiple embedded particles are observed on only one side of the tusk and skull fossils, consistent with micrometeorites coming from a single direction. During recent visits to natural history collections in Berkeley, CA, New York City, and London, UK, embedded Fe-rich particles were uncovered in an additional 13 Alaskan bison, horse, and musk ox skulls, and a Siberian Elasmotherium skull. We propose that the extinctions, embedded micrometeorites, and frozen mummies contemporaneous with the ~37 ka B.P. event all resulted from an airburst (similar to the 1908 Tunguska event), or series of airbursts, across Beringia due to the breakup and deep atmospheric penetration of an Fe-Ni asteroid. The micrometeorites can be envisioned as shrapnel traveling within the blast wave(s). The instantaneous deaths, internal injuries, and possible traumatic amputations and decapitations in megafaunal mummies are consistent with blast injuries related to such a catastrophic scenario.

Exercise in the Cold

PubMed Central

Fudge, Jessie

2016-01-01

Context: Hypothermia and frostbite injuries occur in cold weather activities and sporting events. Evidence Acquisition: A PubMed search was used to identify original research and review articles related to cold, frostbite, and hypothermia. Inclusion was based on their relevance to prevention and treatment of cold-related injuries in sports and outdoor activities. Dates of review articles were limited to those published after 2010. No date limit was set for the most recent consensus statements or original research. Study Design: Clinical review. Level of Evidence: Level 5. Results: Frostbite and hypothermia are well-documented entities with good prevention strategies and prehospital treatment recommendations that have changed very little with time. A layered approach to clothing is the best way to prevent injury and respond to weather changes. Each athlete, defined as a participant in a cold weather sport or activity, will respond to cold differently depending on anthropometric measurements and underlying medical risk factors. An understanding of wind-chill temperatures, wetness, and the weather forecast allows athletes and event coordinators to properly respond to changing weather conditions. At the first sign of a freezing cold injury, ensure warm, dry clothes and move to a protected environment. Conclusion: Cold injuries can be prevented, and cold weather activities are safe with proper education, preparation, and response to changing weather conditions or injury. PMID:26857732

Circadian variation in the circulatory responses to exercise: relevance to the morning peaks in strokes and cardiac events

PubMed Central

2009-01-01

Sudden cardiac and cerebral events are most common in the morning. A fundamental question is whether these events are triggered by the increase in physical activity after waking, and/or a result of circadian variation in the responses of circulatory function to exercise. Although signaling pathways from the master circadian clock in the suprachiasmatic nuclei to sites of circulatory control are not yet understood, it is known that cerebral blood flow, autoregulation and cerebrovascular reactivity to changes in CO2 are impaired in the morning and, therefore, could explain the increased risk of cerebrovascular events. Blood pressure (BP) and the rate pressure product (RPP) show marked ‘morning surges’ when people are studied in free-living conditions, making the rupture of a fragile atherosclerotic plaque and sudden cardiac event more likely. Since cerebral autoregulation is reduced in the morning, this surge in BP may also exacerbate the risk of hemorrhagic and ischemic strokes in the presence of other acute and chronic risk factors. Increased sympathetic activity, decreased endothelial function, and increased platelet aggregability could also be important in explaining the morning peak in cardiac and cerebral events but how these factors respond to exercise at different times of day is unclear. Evidence is emerging that the exercise-related responses of BP and RPP are increased in the morning when prior sleep is controlled. We recommend that such ‘semi-constant routine’ protocols are employed to examine the relative influence of the body clock and exogenous factors on the 24-h variation in other circulatory factors. PMID:19826832

Transcriptome and gene expression analysis in cold-acclimated guayule (Parthenium argentatum)rubber-producing tissue

USDA-ARS?s Scientific Manuscript database

Natural rubber biosynthesis in guayule (Parthenium argentatum) is associated with moderately cold night temperatures. To begin to dissect the molecular events triggered by cold temperatures that govern rubber synthesis induction in guayule, the transcriptome of bark tissue, where rubber is produced...

Exercise and cardiovascular outcomes by hypertensive status: NHANES I epidemiological follow-up study, 1971-1992.

PubMed

Fang, Jing; Wylie-Rosett, Judith; Alderman, Michael H

2005-06-01

A favorable effect of exercise on cardiovascular longevity has been repeatedly demonstrated in the general population. The association of exercise and cardiovascular disease (CVD) outcome among persons with different blood pressure (BP) status is less well known. We examined the epidemiologic follow-up of the First National Health and Nutrition Examination Survey (NHANES I) (1971-1992). Of 14,407 participants, 9791 subjects aged 25 to 74 years met inclusion criteria. All cause, CVD, and non-CVD mortality rates, as well as CVD incidence rates were determined. The associations of levels of exercise and outcomes by BP status were examined. Age- and gender-adjusted rates, as well as Cox proportional hazard models were determined. During 17 years of follow-up, there were 3069 deaths, 1465 of which were CVD. In addition, 2808 subjects had incident CVD events. Overall, CVD incidence and mortality rates increased as BP rose. The association of exercise with CVD events differed by BP status (normal, prehypertension, and hypertension). Age- and gender-adjusted CVD mortality rate per 1000 person-years for least, moderate, and most exercise were 5.0, 3.6, and 2.4 among normotensive subjects (P > .05), 6.3, 4.7, and 5.2 among prehypertensive subjects (P > .05), and 11.8, 9.8, and 8.7 among hypertensive subjects (P < .01), respectively. In fact, exercise was a significant independent predictor of reduced CVD event only among hypertensive subjects, after adjusting for other CVD risk factors. Among prehypertensive and normotensive subjects, where events were fewer, those who exercise more vigorously also had lower mortality, but these differences did not reach statistical significance. This study, consistent with previous observational data, demonstrates that increased exercise is associated with decreased CVD event. Interestingly, this effect is most robust among hypertensive subjects, whereas for prehypertensive and normotensive subjects, a significant benefit of exercise on CVD outcome, perhaps because of lack of power, was not found.

Safety and efficacy of antihypertensive prescription at emergency department discharge.

PubMed

Brody, Aaron; Rahman, Tahsin; Reed, Brian; Millis, Scott; Ference, Brian; Flack, John M; Levy, Phillip D

2015-05-01

Poor blood pressure (BP) control is a primary risk factor for target organ damage in the heart, brain, and kidney. Uncontrolled hypertension is common among emergency department (ED) patients, particularly in underresourced settings, but it is unclear what role ED providers should play in the management of chronic antihypertensive therapy. The objective was to evaluate the safety and efficacy of prescribing antihypertensive therapy from the ED. This was a retrospective study of data pooled from two prospective, longitudinal, randomized controlled trials, both of which enrolled ED patients with asymptomatic hypertension. Antihypertensives were prescribed at emergency physician discretion, and this was not related to randomization arm. Demographic data, BP at screening and randomization visit, and data on adverse effects potentially related to antihypertensive therapy were compiled. Means were compared using Student's t-tests, and proportions were compared using chi-square tests. The effect of antihypertensive therapy on BP control was further analyzed using multivariable regression modeling controlling for age, race, sex, hypertension history, study cohort, and ED BP. Data were abstracted for 217 subjects. The median interval from ED visit to randomization was 12 days. Seventy-six subjects (35%) received one or more prescriptions for antihypertensive therapy. Age, sex, race, hypertension history, and mean duration of hypertension were equivalent between groups. Although mean ED BP was higher among those who received prescriptions, the mean systolic BP (sBP) reduction from ED to randomization was significantly greater (difference = 19 mm Hg, 95% confidence interval = 12 to 26 mm Hg). No patient in either group had an sBP less than 100 mm Hg at randomization. On multiple regression modeling, randomization sBP reduction was independently associated with antihypertensive prescription (p = 0.001). The incidence of adverse effects was equivalent and low in both groups. No new neurological deficits, ischemic events, or life-threatening anaphylactic reactions were reported in either group. Prescription of antihypertensive medication from the ED is associated with significantly lower sBP at short-term outpatient follow-up. Antihypertensive therapy was not associated with an increased incidence of adverse events, and BP reduction did not exceed potentially harmful levels. Initiation of chronic antihypertensive therapy in the ED is safe and effective and may be a reasonable consideration for at-risk populations. © 2015 by the Society for Academic Emergency Medicine.

Geochronology and Geomorphology of the Pioneer Archaeological Site (10BT676), Upper Snake River Plain, Idaho

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keene, Joshua L.

2015-04-01

The Pioneer site in southeastern Idaho, an open-air, stratified, multi-component archaeological locality on the upper Snake River Plain, provides an ideal situation for understanding the geomorphic history of the Big Lost River drainage system. We conducted a block excavation with the goal of understanding the geochronological context of both cultural and geomorphological components at the site. The results of this study show a sequence of five soil formation episodes forming three terraces beginning prior to 7200 cal yr BP and lasting until the historic period, preserving one cultural component dated to ~3800 cal yr BP and multiple components dating tomore » the last 800 cal yr BP. In addition, periods of deposition and stability at Pioneer indicate climate fluctuation during the middle Holocene (~7200-3800 cal yr BP), minimal deposition during the late Holocene, and a period of increased deposition potentially linked to the Little Ice Age. In addition, evidence for a high-energy erosion event dated to ~3800 cal yr BP suggest a catastrophic flood event during the middle Holocene that may correlate with volcanic activity at the Craters of the Moon lava fields to the northwest. This study provides a model for the study of alluvial terrace formations in arid environments and their potential to preserve stratified archaeological deposits.« less

Late Holocene vegetation changes in relation with climate fluctuations and human activities in Languedoc (Southern France)

NASA Astrophysics Data System (ADS)

Azuara, J.; Combourieu-Nebout, N.; Lebreton, V.; Mazier, F.; Müller, S. D.; Dezileau, L.

2015-09-01

Holocene climate fluctuations and human activities since the Neolithic have shaped present-day Mediterranean environments. Separating anthropogenic effects from climatic impacts to reconstruct Mediterranean paleoenvironments over the last millennia remains a challenging issue. High resolution pollen analyses were undertaken on two cores from the Palavasian lagoon system (Hérault, southern France). These records allow reconstruction of vegetation dynamics over the last 4500 years. Results are compared with climatic, historical and archeological archives. A long-term aridification trend is highlighted during the Late Holocene and three superimposed arid events are recorded at 4600-4300, 2800-2400 and 1300-1100 cal BP. These periods of climatic instability coincide in time with the rapid climatic events depicted in the Atlantic Ocean (Bond et al., 2001). From the Bronze Age (4000 cal BP) to the end of the Iron Age (around 2000 cal BP), the spread of evergreen taxa and loss of forest cover result from anthropogenic impact. The Antiquity is characterized by a major reforestation event related to the concentration of rural activities and populations in coastal plains leading to forest recovery in the mountains. A major regional deforestation occurred at the beginning of the High Middle Ages. Around 1000 cal BP, forest cover is minimal while cover of olive, chestnut and walnut expands in relation to increasing human influence. The present day vegetation dominated by Mediterranean shrubland and pines has been in existence since the beginning of the 20th century.

Late Holocene vegetation changes in relation with climate fluctuations and human activity in Languedoc (southern France)

NASA Astrophysics Data System (ADS)

Azuara, J.; Combourieu-Nebout, N.; Lebreton, V.; Mazier, F.; Müller, S. D.; Dezileau, L.

2015-12-01

Holocene climate fluctuations and human activity since the Neolithic have shaped present-day Mediterranean environments. Separating anthropogenic effects from climatic impacts to better understand Mediterranean paleoenvironmental changes over the last millennia remains a challenging issue. High-resolution pollen analyses were undertaken on two cores from the Palavasian lagoon system (Hérault, southern France). These records allow reconstruction of vegetation dynamics over the last 4500 years. Results are compared with climatic, historical and archeological archives. A long-term aridification trend is highlighted during the late Holocene, and three superimposed arid events are recorded at 4600-4300, 2800-2400 and 1300-1100 cal BP. These periods of high-frequency climate variability coincide in time with the rapid climatic events observed in the Atlantic Ocean (Bond et al., 2001). From the Bronze Age (4000 cal BP) to the end of the Iron Age (around 2000 cal BP), the spread of sclerophyllous taxa and loss of forest cover result from anthropogenic impact. Classical Antiquity is characterized by a major reforestation event related to the concentration of rural activity and populations in coastal plains leading to forest recovery in the mountains. A major regional deforestation occurred at the beginning of the High Middle Ages. Around 1000 cal BP, forest cover is minimal while the cover of olive, chestnut and walnut expands in relation to increasing human influence. The present-day vegetation dominated by Mediterranean shrubland and pines has been in existence since the beginning of the 20th century.

"Kill" the messenger: Targeting of cell-derived microparticles in lupus nephritis.

PubMed

Nielsen, Christoffer T; Rasmussen, Niclas S; Heegaard, Niels H H; Jacobsen, Søren

2016-07-01

Immune complex (IC) deposition in the glomerular basement membrane (GBM) is a key early pathogenic event in lupus nephritis (LN). The clarification of the mechanisms behind IC deposition will enable targeted therapy in the future. Circulating cell-derived microparticles (MPs) have been proposed as major sources of extracellular autoantigens and ICs and triggers of autoimmunity in LN. The overabundance of galectin-3-binding protein (G3BP) along with immunoglobulins and a few other proteins specifically distinguish circulating MPs in patients with systemic lupus erythematosus (SLE), and this is most pronounced in patients with active LN. G3BP co-localizes with deposited ICs in renal biopsies from LN patients supporting a significant presence of MPs in the IC deposits. G3BP binds strongly to glomerular basement membrane proteins and integrins. Accordingly, MP surface proteins, especially G3BP, may be essential for the deposition of ICs in kidneys and thus for the ensuing formation of MP-derived electron dense structures in the GBM, and immune activation in LN. This review focuses on the notion of targeting surface molecules on MPs as an entirely novel treatment strategy in LN. By targeting MPs, a double hit may be achieved by attenuating both the autoantigenic fueling of immune complexes and the triggering of the adaptive immune system. Thereby, early pathogenic events may be blocked in contrast to current treatment strategies that primarily target and modulate later events in the cellular and humoral immune response. Copyright © 2016 Elsevier B.V. All rights reserved.

Dual effects of the winter monsoon on haze-fog variations in eastern China

NASA Astrophysics Data System (ADS)

Liu, Qian; Sheng, Lifang; Cao, Ziqi; Diao, Yina; Wang, Wencai; Zhou, Yang

2017-06-01

Previous studies have revealed a negative correlation between the East Asian winter monsoon and wintertime haze-fog events in China. The winter monsoon reduces haze-fog by advecting away aerosol particles and supplying clean air through cold waves. However, it is found that the frequency of haze-fog events on subseasonal time scales displays no correlation with typical winter monsoon indices. The results show that the accumulating and maintaining effects of calm weather related to the Siberian High, which is also a part of the monsoon circulation system, are equally important for the development of haze-fog events during winter. Correlation analysis indicates that subseasonal variations in haze-fog are closely related to the intensity of the Siberian High (r = 0.49). The Siberian High may increase the occurrence of haze-fog events by reducing the near surface wind speed and enhancing the stratification stability. To quantify the contribution of these diverse effects of the winter monsoon on the variations in haze-fog events, we analyzed haze-fog events during periods of cold wave activity and calm weather separately and contrasted the relative contributions of these two effects on different time scales. On the subseasonal scale, the effect of the Siberian High was 2.0 times that of cold waves; on the interannual scale, the effect of cold waves was 2.4 times that of the Siberian High. This study reveals the dual effects of the East Asian winter monsoon on wintertime haze-fog variations in eastern China and provides a more comprehensive understanding of the relationship between the monsoon and haze-fog events.

Nebivolol withdrawal results in blood pressure returning toward pretreatment levels, but without rebound symptoms: phase IV randomized trial.

PubMed

Lewin, Andrew; Lasseter, Kenneth C; Dong, Fang; Whalen, John C

2012-01-01

Rapid withdrawal of antihypertensive drugs may lead to blood pressure (BP) increase above pretreatment values or symptoms such as palpitations, chest pain, and tremor. This phase IV trial assessed the consequences of abrupt and stepwise withdrawal of nebivolol, a β(1)-selective blocker, in individuals with stage I-II hypertension. After a 4- to 5-week placebo washout phase and 12-week single-blind nebivolol treatment (10-40 mg/day, titrated based on BP response), participants achieving BP control (systolic BP [SBP]/diastolic BP [DBP] <140/90 mm Hg) or response (SBP decrease ≥10 mm Hg or DBP decrease ≥5 mm Hg) entered a 4-week, randomized, double-blind phase of continued nebivolol treatment (n = 102) or withdrawal to placebo (n = 105). Primary and secondary efficacy measures were changes in mean sitting DBP and SBP, respectively, analyzed using an analysis of covariance model. Safety and tolerability were also assessed. In the withdrawal phase, nebivolol and placebo groups demonstrated mean DBP increases of 1.8 and 7.7 mm Hg, respectively (P < .001), and SBP increases of 3.5 and 7.6 mm Hg (P = .011). Twenty-three (22.5%) nebivolol-treated and 18 (17.1%) placebo-treated participants experienced a treatment-emergent adverse event. No adverse events associated with β-blocker withdrawal and considered causally related to nebivolol were reported. Nebivolol withdrawal resulted in a mean BP increase near pretreatment levels and was not associated with rebound hypertension. Copyright © 2012 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Late Quaternary paleoclimate of western Alaska inferred from fossil chironomids and its relation to vegetation histories

NASA Astrophysics Data System (ADS)

Kurek, Joshua; Cwynar, Les C.; Ager, Thomas A.; Abbott, Mark B.; Edwards, Mary E.

2009-05-01

Fossil Chironomidae assemblages (with a few Chaoboridae and Ceratopogonidae) from Zagoskin and Burial Lakes in western Alaska provide quantitative reconstructions of mean July air temperatures for periods of the late-middle Wisconsin (˜39,000-34,000 cal yr B.P.) to the present. Inferred temperatures are compared with previously analyzed pollen data from each site summarized here by indirect ordination. Paleotemperature trends reveal substantial differences in the timing of climatic warming following the late Wisconsin at each site, although chronological uncertainty exists. Zagoskin Lake shows early warming beginning at about 21,000 cal yr B.P., whereas warming at Burial Lake begins ˜4000 years later. Summer climates during the last glacial maximum (LGM) were on average ˜3.5 °C below the modern temperatures at each site. Major shifts in vegetation occurred from ˜19,000 to 10,000 cal yr B.P. at Zagoskin Lake and from ˜17,000 to 10,000 cal yr B.P. at Burial Lake. Vegetation shifts followed climatic warming, when temperatures neared modern values. Both sites provide evidence of an early postglacial thermal maximum at ˜12,300 cal yr B.P. These chironomid records, combined with other insect-based climatic reconstructions from Beringia, indicate that during the LGM: (1) greater continentality likely influenced regions adjacent to the Bering Land Bridge and (2) summer climates were, at times, not dominated by severe cold.

Correlation of Late-Pleistocene Lake-Level Oscillations in Mono Lake, California, with North Atlantic Climate Events

USGS Publications Warehouse

Benson, L.V.; Lund, S.P.; Burdett, J.W.; Kashgarian, Michaele; Rose, T.P.; Smoot, J.P.; Schwartz, M.

1998-01-01

Oxygen-18 (18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard-Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to 2000 yr. The youngest low-stand, which occurred between 15,500 and 14,000 14C yr B.P., was nearly synchronous with a desiccation of Owens Lake, California. Paleomagnetic secular variation (PSV) data indicate that three of four persistent lowstands occurred at the same times as Heinrich events H1, H2, and H4. 18O data indicate the two highest lake levels occurred ???18,000 and ???13,100 14C yr B.P., corresponding to passages of the mean position of the polar jet stream over the Mono Basin. Extremely low values of total inorganic carbon between 26,000 and 14,000 14C yr B.P. indicate glacial activity, corresponding to a time when summer insolation was much reduced. ?? 1998 University of Washington.

Stalagmite-inferred centennial variability of the Asian summer monsoon in southwest China between 58 and 79 ka BP

NASA Astrophysics Data System (ADS)

Zhang, Tao-Tao; Li, Ting-Yong; Cheng, Hai; Edwards, R. Lawrence; Shen, Chuan-Chou; Spötl, Christoph; Li, Hong-Chun; Han, Li-Yin; Li, Jun-Yun; Huang, Chun-Xia; Zhao, Xin

2017-03-01

We use a new spliced stalagmite oxygen isotope record from Yangkou Cave and Xinya Cave, Chongqing, southwest China, to reconstruct the centennial-millennial-scale changes in Asian Summer Monsoon (ASM) intensity between 58.0 and 79.3 thousand years before present (ka BP, before AD 1950). This multidecadally resolved record shows four strong ASM periods, corresponding to Greenland Interstadials (GIS) 17-20, and three weak ASM episodes, among which, the one starting at 61.5 ± 0.2 ka BP and ending at 59.4 ± 0.2 ka BP that may correlate with Heinrich Event 6. The close agreement of climate events between China and Greenland supports the notion that the ASM is dominantly governed by high-latitude forcings in the Northern Hemisphere. The short-lived interstadial GIS 18, however, lasted for over 3 kyr in the records derived from ASM region, reflecting a gradual decline of ASM intensity, which coincides with a millennial-scale warming trend in Antarctica. This suggests an additional forcing of the ASM by the Southern Hemisphere, which also affected GIS 8-12, H4 and H5, as shown by previous speleothem studies from the ASM region.

Localized water reverberation phases and its impact on back-projection images

NASA Astrophysics Data System (ADS)

Yue, H.; Castillo, J.; Yu, C.; Meng, L.; Zhan, Z.

2017-12-01

Coherent radiators imaged by back-projections (BP) are commonly interpreted as part of the rupture process. Nevertheless, artifacts introduced by structure related phases are rarely discriminated from the rupture process. In this study, we adopt the logic of empirical Greens' function analysis (EGF) to discriminate between rupture and structure effect. We re-examine the waveforms and BP images of the 2012 Mw 7.2 Indian Ocean earthquake and an EGF event (Mw 6.2). The P wave codas of both events present similar shape with characteristic period of approximately 10 s, which are back-projected as coherent radiators near the trench. S wave BP doesn't image energy radiation near the trench. We interpret those coda waves as localized water reverberation phases excited near the trench. We perform a 2D waveform modeling using realistic bathymetry model, and find that the sharp near-trench bathymetry traps the acoustic water waves forming localized reverberation phases. These waves can be imaged as coherent near-trench radiators with similar features as that in the observations. We present a set of methodology to discriminate between the rupture and propagation effects in BP images, which can serve as a criterion of subevent identification.

A computer model for predicting grapevine cold hardiness

USDA-ARS?s Scientific Manuscript database

We developed a robust computer model of grapevine bud cold hardiness that will aid in the anticipation of and response to potential injury from fluctuations in winter temperature and from extreme cold events. The model uses time steps of 1 day along with the measured daily mean air temperature to ca...

Relationship Between Blood Pressure Values, Depressive Symptoms, and Cardiovascular Outcomes in Patients With Cardiometabolic Disease.

PubMed

Jani, Bhautesh Dinesh; Cavanagh, Jonathan; Barry, Sarah J E; Der, Geoff; Sattar, Naveed; Mair, Frances S

2016-10-01

The authors studied the joint effect of blood pressure (BP) and depression on the risk of major adverse cardiovascular outcome in patients with existing cardiometabolic disease. A cohort of 35,537 patients with coronary heart disease, diabetes, or stroke underwent depression screening and BP measurement recorded concurrently. The authors used Cox's proportional hazards to calculate risk of major adverse cardiovascular event (MACE; myocardial infarction/heart failure/stroke or cardiovascular death) over 4 years associated with baseline BP and depression. A total of 11% (3939) had experienced a MACE within 4 years. Patients with very high systolic BP (160-240 mm Hg; hazard ratio, 1.28) and depression (hazard ratio, 1.22) at baseline had significantly higher adjusted risk. Depression had a significant interaction with systolic BP in risk prediction (P=.03). Patients with a combination of high systolic BP and depression at baseline had 83% higher adjusted risk of MACE, as compared with patients with reference systolic BP without depression. Patients with cardiometabolic disease and comorbid depression may benefit from closer monitoring of systolic BP. © 2016 The Authors. The Journal of Clinical Hypertension Published by Wiley Periodicals, Inc.

Vaccination: a novel strategy for inhibiting the renin-angiotensin-aldosterone system.

PubMed

Gradman, Alan H; Pinto, Rehka

2008-12-01

Immunologic approaches to renin-angiotensin-aldosterone system (RAAS) inhibition have been studied for more than 50 years. In animal models, vaccination against renin was effective but resulted in fatal autoimmune renal disease; vaccines directed at small peptides including angiotensin I and II and a segment of the AT(1) receptor reduced blood pressure (BP) without causing autoimmune disease. In humans, angiotensin I vaccination did not reduce BP. More promising is the AngQb vaccine, which uses an immunization technology involving conjugation of angiotensin II to virus-like particles. In a phase 2 trial, hypertensive patients vaccinated with 300 microg showed a difference of 9.0/4.0 mm Hg from baseline in mean daytime ambulatory BP after 14 weeks (P = 0.015 for systolic BP, P = 0.064 for diastolic BP), and a marked reduction in early morning BP. No serious adverse events were attributed to vaccine administration. Although questions remain regarding efficacy and safety, RAAS immunization represents an innovative and promising approach to hypertension treatment.

Short-lived high-amplitude cooling on Svalbard during the Dark Ages

NASA Astrophysics Data System (ADS)

van der Bilt, Willem; D`Andrea, William; Bakke, Jostein; Balascio, Nicholas; Werner, Johannes; Hoek, Wim

2016-04-01

As the paradigm of a stable Holocene climate has shifted, an increasing number of high-resolution proxy timeseries reveal dynamic conditions, characterized by high-amplitude climate shifts. Some of these events occurred during historical times and allow us to study the interaction between environmental and cultural change, providing valuable lessons for the near future. These include the Dark Ages Cold Period (DACP) between 300 and 800 AD, a period marked by political upheaval and climate instability that remains poorly investigated. Here, we present two temperature reconstructions from the High Arctic Svalbard Archipelago. To this end, we applied the established alkenone-based UK37 paleothermometer on sediments from two lakes on western Spitsbergen, Lake Hajeren and Lake Hakluyt. The Arctic is presently warming twice as fast as the global average and proxy data as well as model simulations suggest that this amplified response is characteristic for regional climate. The Arctic therefore provides a uniquely sensitive environment to study relatively modest climate shifts, like the DACP, that may not be adequately captured at lower-latitude sites. Owing to undisturbed sediments, a high sampling resolution and robust chronological control, the presented reconstructions resolve the attendant sub-centennial-scale climate shifts. Our findings suggest that the DACP marks a cold spell within the cool Neoglacial period, which started some 4 ka BP on Svalbard. Close investigation reveals a distinct temperature minimum around 500 AD that is reproduced in another alkenone-based temperature reconstruction from a nearby lake. At ± 1.75 °C, cooling underlines the sensitivity of Arctic climate as well as the magnitude of the DACP.

Multi-proxy Reconstructions of Deglacial Variability of Antarctic Intermediate Water Circulation in the Western Tropical Atlantic

NASA Astrophysics Data System (ADS)

Huang, K.; Oppo, D.; Curry, W. B.

2012-12-01

Reconstruction of changes in Antarctic Intermediate Water (AAIW) circulation across the last deglaciation is critical in constraining the links between AAIW and Atlantic Meridional Overturning Circulation (AMOC) and understanding how AAIW influences oceanic heat transport and carbon budget across abrupt climate events. Here we systematically establish in situ calibrations for carbonate saturation state (B/Ca), nutrient (Cd/Ca and δ13C) and watermass proxies (ɛNd) in foraminifera using multicore tops and ambient seawater samples collected from the Demerara Rise, western tropical Atlantic. Through the multi-proxy reconstructions, deglacial variability of intermediate water circulation in the western tropical Atlantic can be further constrained. The reconstructed seawater Cd record from the Demerara Rise sediment core (KNR197-3-46CDH, at 947 m water depth) over the last 21 kyrs suggests reduced presence of AAIW during the cold intervals (LGM, H1 and YD) when AMOC was reduced. Down-core B/Ca record shows elevated intermediate water Δ[CO32-] during these cold intervals, further indicating a weaker influence of AAIW in the western tropical Atlantic. The δ13C record exhibits a pronounced deglacial minimum and a clear decoupling between δ13C and Cd/Ca after the AMOC completely recovered at around 8 kyr BP. This could be due to the carbonate ion effect on benthic Cd/Ca or the influence of organic matter remineralization on benthic δ13C. A new ɛNd record for the last deglaciation will be provided to evaluate the relative proportions of southern and northern waters at this intermediate site in the western tropical Atlantic.

The Association Between Antihypertensive Medication Nonadherence and Visit-to-Visit Variability of Blood Pressure: Findings From the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial.

PubMed

Kronish, Ian M; Lynch, Amy I; Oparil, Suzanne; Whittle, Jeff; Davis, Barry R; Simpson, Lara M; Krousel-Wood, Marie; Cushman, William C; Chang, Tara I; Muntner, Paul

2016-07-01

Low adherence to antihypertensive medication has been hypothesized to increase visit-to-visit variability (VVV) of blood pressure (BP). We assessed the association between antihypertensive medication adherence and VVV of BP in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). VVV of BP was calculated using SD independent of mean, SD, and average real variability across study visits conducted 6 to 28 months after randomization. Participants who reported taking <80% of their antihypertensive medication at ≥1 study visits were categorized as nonadherent. Participants were followed up for cardiovascular events and mortality after the assessment of adherence and VVV of BP. SD independent of mean of BP was higher for nonadherent (n=2912) versus adherent (n=16 878) participants; 11.4±4.9 versus 10.5±4.5 for systolic BP; 6.8±2.8 versus 6.2±2.6 for diastolic BP (each P<0.001). SD independent of mean of BP remained higher among nonadherent than among adherent participants after multivariable adjustment (0.8 [95% confidence interval, 0.7-1.0] higher for systolic BP and 0.4 [95% confidence interval, 0.3-0.5] higher for diastolic BP]. SD and average real variability of systolic BP and diastolic BP were also higher among nonadherent than among adherent participants. Adjustment for nonadherence did not explain the association of VVV of BP with higher fatal coronary heart disease or nonfatal myocardial infarction, stroke, heart failure, or mortality risk. In conclusion, improving medication adherence may lower VVV of BP. However, VVV of BP is associated with cardiovascular outcomes independent of medication adherence. © 2016 American Heart Association, Inc.

Temporal Lobe Toxicity Analysis After Proton Radiation Therapy for Skull Base Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pehlivan, Berrin; Ares, Carmen, E-mail: carmen.ares@psi.ch; Lomax, Antony J.

2012-08-01

Purpose: Temporal lobe (TL) parenchyma toxicity constitutes one of the most frequent late adverse event in high-dose proton therapy (PT) for tumors of the skull base. We analyzed clinical events with dosimetric parameters in our patients treated for skull base tumors with spot-scanning PT. Methods and Materials: Between 1998 and 2005, a total of 62 patients received PT to a median dose of 71.7 Gy (relative biologic effectiveness [RBE]) (range, 63-74 Gy). The dose-volume histogram of each TL and the entire brain parenchyma (BP) were analyzed according to maximum, mean, and minimum dose as well as doses to 0.5, 1,more » 2, and 3 cc of brain volume (D{sub 0.5}, D{sub 1}, D{sub 2}, D{sub 3}) and correlated with clinical events. Generalized equivalent uniform dose (gEUD) values were calculated. Results: At a mean follow-up of 38 months (range, 14-92 months), 2 patients had developed symptomatic Grade 3 and 5 patients asymptomatic Grade 1 TL toxicity. Mean doses to a 2-cc volume of BP increased from 71 {+-} 5 Gy (RBE) for no toxicity to 74 {+-} 5 Gy (RBE) for Grade 1 and to 76 {+-} 2 Gy (RBE) for Grade 3 toxicity. TL events occurred in 6 of 7 patients (86%) at or above dose levels of {>=}64 Gy (RBE) D{sub 3}, {>=}68 Gy (RBE) D{sub 2}, {>=}72 Gy (RBE) D{sub 1}, and {>=}73 Gy (RBE) D{sub 0.5}, respectively (p = NS). No statistically significant dose/volume threshold was detected between patients experiencing no toxicity vs. Grade 1 or Grade 3. A strong trend for Grade 1 and 3 events was observed, when the gEUD was 60 Gy. Conclusions: A statistically significant normal tissue threshold dose for BP has not been successfully defined. However, our data suggest that tolerance of TL and BP to fractionated radiotherapy appears to be correlated with tissue volume included in high-dose regions. Additional follow-up time and patient accrual is likely needed to achieve clinical significance for these dose-volume parameters investigated. Our findings support the importance of establishing an organ-at-risk maximally permissible dose for BP.« less

An assessment of postcranial indices, ratios, and body mass versus eco-geographical variables of prehistoric Jomon, Yayoi agriculturalists, and Kumejima Islanders of Japan.

PubMed

Seguchi, Noriko; Quintyn, Conrad B; Yonemoto, Shiori; Takamuku, Hirofumi

2017-09-10

We explore variations in body and limb proportions of the Jomon hunter-gatherers (14,000-2500 BP), the Yayoi agriculturalists (2500-1700 BP) of Japan, and the Kumejima Islanders of the Ryukyus (1600-1800 AD) with 11 geographically diverse skeletal postcranial samples from Africa, Europe, Asia, Australia, and North America using brachial-crural indices, femur head-breadth-to-femur length ratio, femur head-breadth-to-lower-limb-length ratio, and body mass as indicators of phenotypic climatic adaptation. Specifically, we test the hypothesis that variation in limb proportions seen in Jomon, Yayoi, and Kumejima is a complex interaction of genetic adaptation; development and allometric constraints; selection, gene flow and genetic drift with changing cultural factors (i.e., nutrition) and climate. The skeletal data (1127 individuals) were subjected to principle components analysis, Manly's permutation multiple regression tests, and Relethford-Blangero analysis. The results of Manly's tests indicate that body proportions and body mass are significantly correlated with latitude, and minimum and maximum temperatures while limb proportions were not significantly correlated with these climatic variables. Principal components plots separated "climatic zones:" tropical, temperate, and arctic populations. The indigenous Jomon showed cold-adapted body proportions and warm-adapted limb proportions. Kumejima showed cold-adapted body proportions and limbs. The Yayoi adhered to the Allen-Bergmann expectation of cold-adapted body and limb proportions. Relethford-Blangero analysis showed that Kumejima experienced gene flow indicated by high observed variances while Jomon experienced genetic drift indicated by low observed variances. The complex interaction of evolutionary forces and development/nutritional constraints are implicated in the mismatch of limb and body proportions. © 2017 Wiley Periodicals, Inc.

Effects of finite beam and plasma temperature on the growth rate of a two-stream free electron laser with background plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahdizadeh, N.; Aghamir, F. M.

2013-02-28

A fluid theory is used to derive the dispersion relation of two-stream free electron laser (TSFEL) with a magnetic planar wiggler pump in the presence of background plasma (BP). The effect of finite beams and plasma temperature on the growth rate of a TSFEL has been verified. The twelve order dispersion equation has been solved numerically. Three instabilities, FEL along with the TS and TS-FEL instabilities occur simultaneously. The analysis in the case of cold BP shows that when the effect of the beam temperature is taken into account, both instable bands of wave-number and peak growth rate in themore » TS instability increase, but peak growth of the FEL and TS-FEL instabilities decreases. Thermal motion of the BP causes to diminish the TS instability and it causes to decrease the FEL and TS-FEL instabilities. By increasing the beam densities and lowering initial velocities (in the collective Raman regime), growth rate of instabilities increases; however, it has opposite behavior in the Campton regime.« less

Impacts of extreme climatic events on the energetics of long-lived vertebrates: the case of the greater flamingo facing cold spells in the Camargue.

PubMed

Deville, Anne-Sophie; Labaude, Sophie; Robin, Jean-Patrice; Béchet, Arnaud; Gauthier-Clerc, Michel; Porter, Warren; Fitzpatrick, Megan; Mathewson, Paul; Grémillet, David

2014-10-15

Most studies analyzing the effects of global warming on wild populations focus on gradual temperature changes, yet it is also important to understand the impact of extreme climatic events. Here we studied the effect of two cold spells (January 1985 and February 2012) on the energetics of greater flamingos (Phoenicopterus roseus) in the Camargue (southern France). To understand the cause of observed flamingo mass mortalities, we first assessed the energy stores of flamingos found dead in February 2012, and compared them with those found in other bird species exposed to cold spells and/or fasting. Second, we evaluated the monthly energy requirements of flamingos across 1980-2012 using the mechanistic model Niche Mapper. Our results show that the body lipids of flamingos found dead in 2012 corresponded to 2.6±0.3% of total body mass, which is close to results found in woodcocks (Scolopax rusticola) that died from starvation during a cold spell (1.7±0.1%), and much lower than in woodcocks which were fed throughout this same cold spell (13.0±2%). Further, Niche Mapper predicted that flamingo energy requirements were highest (+6-7%) during the 1985 and 2012 cold spells compared with 'normal' winters. This increase was primarily driven by cold air temperatures. Overall, our findings strongly suggest that flamingos starved to death during both cold spells. This study demonstrates the relevance of using mechanistic energetics modelling and body condition analyses to understand and predict the impact of extreme climatic events on animal energy balance and winter survival probabilities. © 2014. Published by The Company of Biologists Ltd.

Millennial-scale variability in south-east Australian hydroclimate between 30,000 and 10,000 years ago

NASA Astrophysics Data System (ADS)

Falster, Georgina; Tyler, Jonathan; Grant, Katharine; Tibby, John; Turney, Chris; Löhr, Stefan; Jacobsen, Geraldine; Kershaw, A. Peter

2018-07-01

Global climate variability during the late Quaternary is commonly investigated within the framework of the 'bipolar seesaw' pattern of asynchronous temperature variations in the northern and southern polar latitudes. The terrestrial hydrological response to this pattern in south-eastern Australia is not fully understood, as continuous, high-resolution, well-dated proxy records for the hydrological cycle in the region are sparse. Here we present a well-dated, highly resolved record of moisture balance spanning 30000-10000 calendar years before present (30-10 ka BP), based on x-ray fluorescence and organic carbon isotope (δ13COM) measurements of a sedimentary sequence from Lake Surprise in south-eastern Australia. The data provide a locally coherent record of the hydrological cycle. Elevated Si (reflecting windblown quartz and clays), and relatively high δ13COM, indicate an extended period of relative aridity between 28 and 18.5 ka BP, interrupted by millennial-scale episodes of decreased Si and δ13COM, suggesting increased moisture balance. This was followed by a rapid deglacial shift to low Si and δ13COM at 18.5 ka BP, indicative of wetter conditions. We find that these changes are coeval with other records from south-eastern Australia and New Zealand, and use a Monte Carlo Empirical Orthogonal Function approach to extract a common trend from three high-resolution records. Our analyses suggest that drivers of the regional hydrological cycle have varied on multi-millennial time scales, in response to major shifts in global atmosphere-ocean dynamics during the last glacial-interglacial transition. Southern Ocean processes were the dominant control on hydroclimate during glacial times, via a strong influence of cold sea surface temperatures on moisture uptake and delivery onshore. Following the last deglaciation (around 18 ka BP), the southward migration of cold Southern Ocean fronts likely resulted in the establishment of conditions more like those of the present day. Millennial-scale variability in records from the region is dominated by a persistent ca. 2300-year periodicity, consistent with other records across the Southern Hemisphere mid-latitudes; however, this pervasive periodicity is not obviously linked to the 'bipolar seesaw' and the mechanism remains equivocal.

Eastern Pacific cooling and Atlantic overturning circulation during the last deglaciation.

PubMed

Kienast, Markus; Kienast, Stephanie S; Calvert, Stephen E; Eglinton, Timothy I; Mollenhauer, Gesine; François, Roger; Mix, Alan C

2006-10-19

Surface ocean conditions in the equatorial Pacific Ocean could hold the clue to whether millennial-scale global climate change during glacial times was initiated through tropical ocean-atmosphere feedbacks or by changes in the Atlantic thermohaline circulation. North Atlantic cold periods during Heinrich events and millennial-scale cold events (stadials) have been linked with climatic changes in the tropical Atlantic Ocean and South America, as well as the Indian and East Asian monsoon systems, but not with tropical Pacific sea surface temperatures. Here we present a high-resolution record of sea surface temperatures in the eastern tropical Pacific derived from alkenone unsaturation measurements. Our data show a temperature drop of approximately 1 degrees C, synchronous (within dating uncertainties) with the shutdown of the Atlantic meridional overturning circulation during Heinrich event 1, and a smaller temperature drop of approximately 0.5 degrees C synchronous with the smaller reduction in the overturning circulation during the Younger Dryas event. Both cold events coincide with maxima in surface ocean productivity as inferred from 230Th-normalized carbon burial fluxes, suggesting increased upwelling at the time. From the concurrence of equatorial Pacific cooling with the two North Atlantic cold periods during deglaciation, we conclude that these millennial-scale climate changes were probably driven by a reorganization of the oceans' thermohaline circulation, although possibly amplified by tropical ocean-atmosphere interaction as suggested before.

Early Holocene vegetation - climate interactions in the central part of European Russia

NASA Astrophysics Data System (ADS)

Novenko, Elena; Olchev, Alexander

2017-04-01

The new Early Holocene vegetation and climate reconstruction (approximately 10100 -7800 cal. yr. BP) for the forest zone the central European Russia are based on pollen records from three key regions located in taiga, mixed coniferous-broadleaved and broadleaved forest zones. The climatic parameters (the mean annual temperature and precipitation) and total forest coverage during the early Holocene were reconstructed using the Best Modern Analogue technique. Information about moistening conditions was revealed from reconstructions of actual evapotranspiration (ET) and potential evaporation (PET). For calculation of the annual ET and PET rates of the forest landscapes a regression model was applied. The model is based on nonlinear approximations of annual values of ET and PET provided by the Levenberg-Marquardt method using the results of numerical simulations of ET and PET carried out by a Mixfor-SVAT model for the forests with different species compositions under various thermal and moistening conditions. Mixfor-SVAT is an one-dimensional model of the energy, H2O and CO2 exchange between vertically structured mono- and multi-specific forest stands and the atmosphere (Olchev et al., 2002). Obtained results showed that the considered period was characterized by relatively low air temperatures and high precipitation compared with modern conditions. Analysis of the long-term pattern of the mean annual temperature for all three regions reveal two synchronous significant cooling periods observed in 9100-9300 cal. yr. BP and 8100-8500 cal. yr. BP as well as rapid growth of the air temperature in 8100-7800 cal. yr. BP, when the annual temperatures increased by 3°C during about 300 years. The cooling phase of 8100-8500 cal. yr. BP could be corresponded to the distinct "8.2 ka event" widely recorded across Europe. Periods of climate warming are coincided with periods of precipitation rise whereas the cool phases are characterized by its decrease. The lowest ET and PET rates were obtained for northern sites in taiga and mixed coniferous-broadleaved forest zone. In particular during the cooling phases of 9100-9300 and 8100-8500 cal. yr. BP ET fell down to 220-230 mm per year and PET - to 400-410 mm year-1. For the southern region ET and PET were some higher but not exceeded 320 and 470 mm per year. The ratio of actual evapotranspiration and precipitation amount showed significant decrease of the ratio in period of cooling phases (down to 0.27). It can be a clear indicator of overwatering of the ground surface and high probability for mire formation. Relatively cold and moist climate provided relatively unfavorable conditions for forest growth. According to made reconstructions the birch and pine-birch woodlands spread over the vast area of European Russia during the Boreal and early Atlantic periods of the Holocene (10100-7900 cal. yr. BP). Forests occupied not more then 30-50% of the study area and dense forests situated only on the south of modern forest zone. The climate warming after 7900 cal. yr. BP was accomplished by expansion of broad-leaved tree species and significant increase of total forest coverage. This study was supported by the Russian Science Foundation (Grant 16-17-10045).

Genome-Wide Association Study Identifies Eight Novel Loci Associated with Blood Pressure Responses to Interventions in Han Chinese

PubMed Central

He, Jiang; Kelly, Tanika N.; Zhao, Qi; Li, Hongfan; Huang, Jianfeng; Wang, Laiyuan; Jaquish, Cashell E.; Sung, Yun Ju; Shimmin, Lawrence C.; Lu, Fanghong; Mu, Jianjun; Hu, Dongsheng; Ji, Xu; Shen, Chong; Guo, Dongshuang; Ma, Jixiang; Wang, Renping; Shen, Jinjin; Li, Shengxu; Chen, Jing; Mei, Hao; Chen, Chung-Shiuan; Chen, Shufeng; Chen, Jichun; Li, Jianxin; Cao, Jie; Lu, Xiangfeng; Wu, Xigui; Rice, Treva K.; Gu, C. Charles; Schwander, Karen; Hamm, L. Lee; Liu, Depei; Rao, Dabeeru C.; Hixson, James E.; Gu, Dongfeng

2014-01-01

Background Blood pressure (BP) responses to dietary sodium and potassium intervention and cold pressor test (CPT) vary considerably among individuals. We aimed to identify novel genetic variants influencing individuals’ BP responses to dietary intervention and CPT. Methods and Results We conducted a genome-wide association study of BP responses in 1,881 Han Chinese and de novo genotyped top findings in 698 Han Chinese. Diet-feeding study included a 7-day low-sodium (51.3 mmol/day), a 7-day high-sodium (307.8 mmol/day), and a 7-day high-sodium plus potassium-supplementation (60 mmol/day). Nine BP measurements were obtained during baseline observation and each intervention period. The meta-analyses identified eight novel loci for BP phenotypes, which physically mapped in or near PRMT6 (P=7.29×10−9), CDCA7 (P=3.57×10−8), PIBF1 (P=1.78×10−9), ARL4C (P=1.86×10−8), IRAK1BP1 (P=1.44×10−10), SALL1 (P=7.01×10−13), TRPM8 (P=2.68×10−8), and FBXL13 (P=3.74×10−9). There was a strong dose-response relationship between the number of risk alleles of these independent SNPs and the risk of developing hypertension over 7.5-year follow-up in the study participants. Compared to those in the lowest quartile of risk alleles, odds ratios (95% confidence intervals) for those in the second, third and fourth quartiles were 1.39 (0.97, 1.99), 1.72 (1.19, 2.47), and 1.84 (1.29, 2.62), respectively (P=0.0003 for trend). Conclusions Our study identified 8 novel loci for BP responses to dietary sodium and potassium intervention and CPT. The effect size of these novel loci on BP phenotypes are much larger than those reported by the previously published studies. Furthermore, these variants predict the risk of developing hypertension among individuals with normal BP at baseline. PMID:24165912

Investigation of the Mid-Atlantic coast sudden cold water

NASA Astrophysics Data System (ADS)

Sun, D.; Kafatos, M.; Liu, Z.; Chiu, L.

2003-12-01

In the midsummer of this year, it was reported that there was a tremendous change in ocean temperature along the Mid-Atlantic coast, dropping as much as 10 degrees overnight. This sudden sea surface temperature drop affected local tourism and fishing, keep the tourists out of water at this vacation time, caused local tuna fishing hasn't been as good this year, but the cold water lured chill-loving striped bass close to shore, and has two to three weeks of great rockfish, which fishermen could normally get till fall. This article investigates this event by using satellite observations, numerical model outputs, and surface weather analysis. It is found that the North Atlantic cold current, combined with the coastal upwelling driven by the weather influence might cause this sudden cold SST event.

Reconstructing Fire Disturbances in Coastal Temperate Rainforests on the Central Coast of British Columbia, Canada

NASA Astrophysics Data System (ADS)

Hoffman, Kira; Smith, Dan; Lertzman, Ken; Starzomski, Brian

2015-04-01

The coastal temperate rainforests of British Columbia's Central Coast are comprised of old growth, mixed-age stands and a mosaic of non-forested bogs. This region receives approximately 4000 mm of annual rainfall, and fire disturbances caused by lightning are thought to be very rare. Because of the late successional characteristics of these forests and the presumed lack of visible fire evidence, fires have been estimated to occur at up to 6000-year return intervals. We attempt to distinguish the roles of natural and cultural (First Nations) fires using multiple lines of evidence from tree ring records, fire-scarred trees, soil charcoal and archaeological evidence from First Nations settlement areas. To reconstruct the Holocene fire history of the study area located on Hecate Island (N 51 38 W -128 05), thirty 400m2 forest mensuration plots were systematically established in a 287-hectare area burned in 1893. Analyses focused on the relationship between fire events and climate recorded in tree rings and instrumental records, as well as nutrient concentrations and pH of soils and plant community characteristics. Four fire events (1893, 1776, 1525, 1372) were recorded in forty-five living, fire-scarred western redcedar (Thuja plicata), yellow cedar (Xanthocyparis nootkatensis) and shore pine (Pinus contorta var. contorta) trees. Five additional fire events (1785 Cal BP, 2760 Cal BP, 3355 Cal BP, 4735 Cal BP, 7740 Cal BP) were dated with accelerated mass spectrometry radiocarbon dating of in situ macro charcoal (> 5mm) buried in stratigraphy in both organic and mineral soils. The short intervals between fire events, coupled with the long history of First Nations settlement and land use in the study area, suggest purposeful and repeated low-intensity ground fires. Our research demonstrates that fires are more widespread and common than previously recorded on the very wet Central Coast of British Columbia. It is important to incorporate cultural fires into fire history research to better understand the ecological legacies associated with repeat fire disturbances in coastal temperate rainforests.

North Sea Storm Driving of Extreme Wave Heights

NASA Astrophysics Data System (ADS)

Bell, Ray; Gray, Suzanne; Jones, Oliver

2017-04-01

The relationship between storms and extreme ocean waves in the North sea is assessed using a long-period wave dataset and storms identified in the Interim ECMWF Re-Analysis (ERA-Interim). An ensemble sensitivity analysis is used to provide information on the spatial and temporal forcing from mean sea-level pressure and surface wind associated with extreme ocean wave height responses. Extreme ocean waves in the central North Sea arise due to either the winds in the cold conveyor belt (northerly-wind events) or winds in the warm conveyor belt (southerly-wind events) of extratropical cyclones. The largest wave heights are associated with northerly-wind events which tend to have stronger wind speeds and occur as the cold conveyor belt wraps rearwards round the cyclone to the cold side of the warm front. The northerly-wind events also provide a larger fetch to the central North Sea. Southerly-wind events are associated with the warm conveyor belts of intense extratropical storms developing in the right upper-tropospheric jet exit region. There is predictability in the extreme ocean wave events up to two days before the event associated with a strengthening of a high pressure system to the west (northerly-wind events) and south-west (southerly-wind events) of the British Isles. This acts to increase the pressure gradient over the British Isles and therefore drive stronger wind speeds in the central North sea.

Gazpacho consumption is associated with lower blood pressure and reduced hypertension in a high cardiovascular risk cohort. Cross-sectional study of the PREDIMED trial.

PubMed

Medina-Remón, A; Vallverdú-Queralt, A; Arranz, S; Ros, E; Martínez-González, M A; Sacanella, E; Covas, M I; Corella, D; Salas-Salvadó, J; Gómez-Gracia, E; Ruiz-Gutiérrez, V; Lapetra, J; García-Valdueza, M; Arós, F; Saez, G T; Serra-Majem, L; Pinto, X; Vinyoles, E; Estruch, R; Lamuela-Raventos, R M

2013-10-01

Hypertension is a major public health problem and a leading cause of death and disability in both developed and developing countries, affecting one-quarter of the world's adult population. Our aim was to evaluate whether the consumption of gazpacho, a Mediterranean vegetable-based cold soup rich in phytochemicals, is associated with lower blood pressure (BP) and/or reduced prevalence of hypertension in individuals at high cardiovascular risk. We selected 3995 individuals (58% women, mean age 67 y) at high cardiovascular risk (81% hypertensive) recruited into the PREDIMED study. BP, weight, and dietary and physical activity data were collected. In multivariate linear regression analyses, after adjustment, moderate and high gazpacho consumption categories were associated with reduced mean systolic BP of -1.9 mm Hg [95% confidence interval (CI): -3.4; -0.6] and -2.6 mm Hg (CI: -4.2; -1.0), respectively, and reduced diastolic BP of -1.5 mm Hg (CI: -2.3; -0.6) and -1.9 mm Hg (CI: -2.8; -1.1). By multiple-adjusted logistic regression analysis, gazpacho consumption was associated with a lower prevalence of hypertension, with OR = 0.85 (CI: 0.73; 0.99) for each 250 g/week increase and OR = 0.73 (CI: 0.55; 0.98) for high gazpacho consumption groups compared to the no-consumption group. Gazpacho consumption was inversely associated with systolic and diastolic BP and prevalence of hypertension in a cross-sectional Mediterranean population at high cardiovascular risk. The association between gazpacho intake and reduction of BP is probably due to synergy among several bioactive compounds present in the vegetable ingredients used to make the recipe. Copyright © 2012 Elsevier B.V. All rights reserved.

A 28,000 year history of vegetation and climate from Lower Red Rock Lake, Centennial Valley, Southwestern Montana, USA

USGS Publications Warehouse

Mumma, Stephanie Ann; Whitlock, Cathy; Pierce, Kenneth

2012-01-01

A sediment core extending to 28,000 cal yr BP from Lower Red Rock Lake in the Centennial Valley of southwestern Montana provides new information on the nature of full-glacial vegetation as well as a history of late-glacial and Holocene vegetation and climate in a poorly studied region. Prior to 17,000 cal yr BP, the eastern Centennial Valley was occupied by a large lake (Pleistocene Lake Centennial), and valley glaciers were present in adjacent mountain ranges. The lake lowered upon erosion of a newly formed western outlet in late-glacial time. High pollen percentages of Juniperus, Poaceae, Asteraceae, and other herbs as well as low pollen accumulation rates suggest sparse vegetation cover. Inferred cold dry conditions are consistent with a strengthened glacial anticyclone at this time. Between 17,000 and 10,500 cal yr BP, high Picea and Abies pollen percentages suggest a shift to subalpine parkland and warmer conditions than before. This is attributed to the northward shift of the jet stream and increasing summer insolation. From 10,500 to 7100 cal yr BP, pollen evidence of open dry forests suggests warm conditions, which were likely a response to increased summer insolation and a strengthened Pacific subtropical high-pressure system. From 7100 to 2400 cal yr BP, cooler moister conditions promoted closed forest and wetlands. Increases in Picea and Abies pollen percentages after 2400 cal yr BP suggest increasing effective moisture. The postglacial pattern of Pseudotsuga expansion indicates that it arrived later on the Atlantic side of the Continental Divide than on the Pacific side. The Divide may have been a physical barrier for refugial populations or it delimited different climate regions that influenced the timing of Pseudotsuga expansion.

Perspective Research Progress in Cold Responses of Capsella bursa-pastoris

PubMed Central

Noman, Ali; Kanwal, Hina; Khalid, Noreen; Sanaullah, Tayyaba; Tufail, Aasma; Masood, Atifa; Sabir, Sabeeh-ur-Rasool; Aqeel, Muhammad; He, Shuilin

2017-01-01

Plants respond to cold stress by modulating biochemical pathways and array of molecular events. Plant morphology is also affected by the onset of cold conditions culminating at repression in growth as well as yield reduction. As a preventive measure, cascades of complex signal transduction pathways are employed that permit plants to endure freezing or chilling periods. The signaling pathways and related events are regulated by the plant hormonal activity. Recent investigations have provided a prospective understanding about plant response to cold stress by means of developmental pathways e.g., moderate growth involved in cold tolerance. Cold acclimation assays and bioinformatics analyses have revealed the role of potential transcription factors and expression of genes like CBF, COR in response to low temperature stress. Capsella bursa-pastoris is a considerable model plant system for evolutionary and developmental studies. On different occasions it has been proved that C. bursa-pastoris is more capable of tolerating cold than A. thaliana. But, the mechanism for enhanced low or freezing temperature tolerance is still not clear and demands intensive research. Additionally, identification and validation of cold responsive genes in this candidate plant species is imperative for plant stress physiology and molecular breeding studies to improve cold tolerance in crops. We have analyzed the role of different genes and hormones in regulating plant cold resistance with special reference to C. bursa-pastoris. Review of collected data displays potential ability of Capsella as model plant for improvement in cold stress regulation. Information is summarized on cold stress signaling by hormonal control which highlights the substantial achievements and designate gaps that still happen in our understanding. PMID:28855910

Mitochondrial genome sequence of the Tibetan wild ass (Equus kiang).

PubMed

Luo, Yongjun; Chen, Yu; Liu, Fuyu; Jiang, Chunhua; Gao, Yuqi

2011-02-01

The Tibetan wild ass, or kiang (Equus kiang) is endemic to the cold and hypoxic (4000-7000 m above sea level) climates of the montane and alpine grasslands of the Tibetan Plateau. We report here the complete nucleotide sequence of the E. kiang mitochondrial genome. Our results show that E. kiang mitochondrial DNA is 16,634 bp long, and predicted to encode all the 37 genes that are typical for vertebrates.

Late Holocene stratigraphy of the Tetimpa archaeological sites, northeast flank of Popocatepetl volcano, central Mexico

USGS Publications Warehouse

Panfil, M.S.; Gardner, T.W.; Hirth, K.G.

1999-01-01

Late Holocene (240 km2 on the east side of the volcano with >25 cm of tephra. Lavas from eruptive sequence I dammed drainage in the lowland area near the town of San Nicolas and caused local upstream deposition of as much as 30 m of lacustrine silts, clays, and sands. These lacustrine deposits record an eruptive hiatus for the Tetimpa area of about 750 14C yr: between ca. 2100 and ca. 1350 yr B.P., no major tephras were deposited in the Tetimpa area. In upland areas, this time period is represented by an unconformity and by Entisols formed in the top of pumice deposits and lavas from eruptive sequence I. Artifacts, agricultural furrows, and dwellings record human reoccupation of this surface. At the end of this hiatus, several lahars were deposited above the lacustrine sequence and locally above the Entisol in upland positions adjacent to streams. Between ca. 1350 and ca. 1200 yr B.P., tephras from eruptive sequence II buried these paleosols, occupation sites, lacustrine sediments, and lahars. Andesitic (~62% SiO2) pumice lapilli deposits in the Tetimpa area record three pumice-fall eruptions directed northeast and east of the crater. The first and smallest of these (maximum Tetimpa area thickness = 12 cm; >52 km2 covered by >25 cm) took place at ca. 1350 yr B.P. and was accompanied by pyroclastic surge events preserved in the Tetimpa area by charcoal, sand waves, and cross-stratified sand-sized tephra. At ca. 1200 yr B.P., the products of two Plinian-style events and additional pyroclastic surges reached the Tetimpa area. The largest of these tephra-fall events covered the Tetimpa area with 0.5-1 m of tephra and blanketed an area of >230 km2 with a thickness of >25 cm. The Tetimpa record confirms two of the four periods of explosive volcanism recognized by studies conducted around Popocatepetl in the past 30 yr. Eruptive sequence I corresponds to the explosive period between 2100 and 2500 yr B.P., and eruptive sequence II corresponds to the period between 900 and 1400 yr B.P. The archaeology and lacustrine stratigraphy of the Tetimpa area help constrain the timing of the Plinian phase of eruptive sequence I to ca. 2100 yr B.P. and suggest that the pumice-fall eruptions of eruptive sequence II took place in at least two intervals between ca. 1350 and ca. 1200 yr B.P.

Know your limits? Climate extremes impact the range of Scots pine in unexpected places.

PubMed

Julio Camarero, J; Gazol, Antonio; Sancho-Benages, Santiago; Sangüesa-Barreda, Gabriel

2015-11-01

Although extreme climatic events such as drought are known to modify forest dynamics by triggering tree dieback, the impact of extreme cold events, especially at the low-latitude margin ('rear edge') of species distributional ranges, has received little attention. The aim of this study was to examine the impact of one such extreme cold event on a population of Scots pine (Pinus sylvestris) along the species' European southern rear-edge range limit and to determine how such events can be incorporated into species distribution models (SDMs). A combination of dendrochronology and field observation was used to quantify how an extreme cold event in 2001 in eastern Spain affected growth, needle loss and mortality of Scots pine. Long-term European climatic data sets were used to contextualize the severity of the 2001 event, and an SDM for Scots pine in Europe was used to predict climatic range limits. The 2001 winter reached record minimum temperatures (equivalent to the maximum European-wide diurnal ranges) and, for trees already stressed by a preceding dry summer and autumn, this caused dieback and large-scale mortality. Needle loss and mortality were particularly evident in south-facing sites, where post-event recovery was greatly reduced. The SDM predicted European Scots pine distribution mainly on the basis of responses to maximum and minimum monthly temperatures, but in comparison with this the observed effects of the 2001 cold event at the southerly edge of the range limit were unforeseen. The results suggest that in order to better forecast how anthropogenic climate change might affect future forest distributions, distribution modelling techniques such as SDMs must incorporate climatic extremes. For Scots pine, this study shows that the effects of cold extremes should be included across the entire distribution margin, including the southern 'rear edge', in order to avoid biased predictions based solely on warmer climatic scenarios. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Climate Degradation and Extreme Icing Events Constrain Life in Cold-Adapted Mammals.

PubMed

Berger, J; Hartway, C; Gruzdev, A; Johnson, M

2018-01-18

Despite the growth in knowledge about the effects of a warming Arctic on its cold-adapted species, the mechanisms by which these changes affect animal populations remain poorly understood. Increasing temperatures, declining sea ice and altered wind and precipitation patterns all may affect the fitness and abundance of species through multiple direct and indirect pathways. Here we demonstrate previously unknown effects of rain-on-snow (ROS) events, winter precipitation, and ice tidal surges on the Arctic's largest land mammal. Using novel field data across seven years and three Alaskan and Russian sites, we show arrested skeletal growth in juvenile muskoxen resulting from unusually dry winter conditions and gestational ROS events, with the inhibitory effects on growth from ROS events lasting up to three years post-partum. Further, we describe the simultaneous entombment of 52 muskoxen in ice during a Chukchi Sea winter tsunami (ivuniq in Iñupiat), and link rapid freezing to entrapment of Arctic whales and otters. Our results illustrate how once unusual, but increasingly frequent Arctic weather events affect some cold-adapted mammals, and suggest that an understanding of species responses to a changing Arctic can be enhanced by coalescing groundwork, rare events, and insights from local people.

Overview of deaths associated with natural events, United States, 1979-2004.

PubMed

Thacker, Maria T F; Lee, Robin; Sabogal, Raquel I; Henderson, Alden

2008-06-01

Analysis of the National Center for Health Statistics' Compressed Mortality File showed that between 1979 and 2004, natural events caused 21,491 deaths in the United States. During this 26-year period, there were 10,827 cold-related deaths and 5,279 heat-related deaths. Extreme cold or heat accounted for 75 per cent of the total number of deaths attributed to natural events--more than all of deaths resulting from lightning, storms and foods, and earth movements, such as earthquakes and landslides. Cold-related death rates were highest in the states of Alaska, Montana, New Mexico, and South Dakota, while heat-related deaths were highest in the states of Arizona, Missouri, and Arkansas. These deaths occurred more often among the elderly and black men. Other deaths were attributed to lightning (1,906), storms and foods (2,741), and earth movements (738). Most deaths associated with natural events are preventable and society can take action to decrease the morbidity and mortality connected with them.

Plasma characteristics of upflowing ion beams in the polar cap region

NASA Technical Reports Server (NTRS)

Chen, M. W.; Ashour-Abdalla, M.; Peterson, W. K.; Moore, T. E.; Persoon, A. M.

1990-01-01

The plasma characteristics of upflowing ion stream events with energies greater than 10 eV in the polar cap region near solar maximum are analyzed. It is found that, in 22 of the 41 polar ion streaming events studied, O(+) is the dominant ion constituent in the upflowing beam components. There are significant amounts of upflowing O(+) in the plasma even during quiet auroral conditions. In one event, the upflowing O(+) population had two components, a cold distribution and a warm one. In another event the O(+) and H(+) temperatures suggested that ionospheric ions are heated. The cold upflowing ion stream component observed in some of the polar ion streaming events exhibited a filamentary nature. A significant amount of He(+) was also found in some of the events studied.

Ambulatory Pulse Wave Velocity Is a Stronger Predictor of Cardiovascular Events and All-Cause Mortality Than Office and Ambulatory Blood Pressure in Hemodialysis Patients.

PubMed

Sarafidis, Pantelis A; Loutradis, Charalampos; Karpetas, Antonios; Tzanis, Georgios; Piperidou, Alexia; Koutroumpas, Georgios; Raptis, Vasilios; Syrgkanis, Christos; Liakopoulos, Vasilios; Efstratiadis, Georgios; London, Gérard; Zoccali, Carmine

2017-07-01

Arterial stiffness and augmentation of aortic blood pressure (BP) measured in office are known cardiovascular risk factors in hemodialysis patients. This study examines the prognostic significance of ambulatory brachial BP, central BP, pulse wave velocity (PWV), and heart rate-adjusted augmentation index [AIx(75)] in this population. A total of 170 hemodialysis patients underwent 48-hour ambulatory monitoring with Mobil-O-Graph-NG during a standard interdialytic interval and followed-up for 28.1±11.2 months. The primary end point was a combination of all-cause death, nonfatal myocardial infarction, and nonfatal stroke. Secondary end points included: (1) all-cause mortality; (2) cardiovascular mortality; and (3) a combination of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, resuscitation after cardiac arrest, coronary revascularization, or hospitalization for heart failure. During follow-up, 37(21.8%) patients died and 46(27.1%) had cardiovascular events. Cumulative freedom from primary end point was similar for quartiles of predialysis-systolic BP (SBP), 48-hour peripheral-SBP, and central-SBP, but was progressively longer for increasing quartiles for 48-hour peripheral-diastolic BP and central-diastolic BP and shorter for increasing quartiles of 48-hour central pulse pressure (83.7%, 71.4%, 69.0%, 62.8% [log-rank P =0.024]), PWV (93.0%, 81.0%, 57.1%, 55.8% [log-rank P <0.001]), and AIx(75) (88.4%, 66.7%, 69.0%, 62.8% [log-rank P =0.014]). The hazard ratios for all-cause mortality, cardiovascular mortality, and the combined outcome were similar for quartiles of predialysis-SBP, 48-hour peripheral-SBP, and central-SBP, but were increasing with higher ambulatory PWV and AIx(75). In multivariate analysis, 48-hour PWV was the only vascular parameter independently associated with the primary end point (hazard ratios, 1.579; 95% confidence intervals, 1.187-2.102). Ambulatory PWV, AIx(75), and central pulse pressure are associated with increased risk of cardiovascular events and mortality, whereas office and ambulatory SBP are not. These findings further support that arterial stiffness is the prominent cardiovascular risk factor in hemodialysis. © 2017 American Heart Association, Inc.

Early intervention of long-acting nifedipine GITS reduces brachial-ankle pulse wave velocity and improves arterial stiffness in Chinese patients with mild hypertension: a 24-week, single-arm, open-label, prospective study.

PubMed

Zhang, Jidong; Wang, Yan; Hu, Haijuan; Yang, Xiaohong; Tian, Zejun; Liu, Demin; Gu, Guoqiang; Zheng, Hongmei; Xie, Ruiqin; Cui, Wei

2016-01-01

Nifedipine gastrointestinal therapeutic system (GITS) is used to treat angina and hypertension. The authors aimed to study the early intervention impact on arterial stiffness and pulse wave velocity (PWV) independent of its blood-pressure-(BP) lowering effect in mild hypertensive patients. This single-center, single-arm, open-label, prospective, Phase IV study recruited patients with mild hypertension and increased PWV from December 2013 to December 2014 (N=138; age, 18-75 years; systolic blood pressure, 140-160 mmHg; diastolic BP, 90-100 mmHg; increased brachial-ankle pulse wave velocity [baPWV, ≥12 m/s]). Nifedipine GITS (30 mg/d) was administered for 24 weeks to achieve target BP of <140/90 mmHg. The dose was uptitrated at 60 mg/d in case of unsatisfactory BP reduction after 4 weeks. Primary study end point was the change in baPWV after nifedipine GITS treatment. Hemodynamic parameters (office BP, 24-hour ambulatory BP monitoring, and heart rate and adverse events) were evaluated at baseline and followed-up at 2, 4, 8, 12, 18, and 24 weeks. Majority of patients (n=117; 84.8%) completed the study. baPWV decreased significantly at 4 weeks compared with baseline (1,598.87±239.82 vs 1,500.89±241.15 cm/s, P <0.001), was stable at 12 weeks (1,482.24±215.14 cm/s, P <0.001), and remained steady through 24 weeks (1,472.58±205.01 cm/s, P <0.001). Office BP reduced from baseline to week 4 (154/95 vs 136/85 mmHg) and remained steady until 24 weeks. Nifedipine GITS significantly decreased 24-hour ambulatory BP monitoring ( P <0.001) after 24 weeks from baseline. Mean arterial pressure and pulse pressure were lowered significantly after 4, 12, and 24 weeks of treatment ( P <0.001). These changes in baPWV were significantly correlated with changes in systolic blood pressure, diastolic BP, and mean arterial pressure ( P <0.05), but not with changes in pulse pressure ( P >0.05). There were no other drug-related serious adverse events. Nifedipine GITS was considerably effective in reducing baPWV and BP, indicating improvement in arterial stiffness as early as 4 weeks.

Timing and east-west correlation of south Swedish ice marginal lines during the Late Weichselian

NASA Astrophysics Data System (ADS)

Lundqvist, Jan; Wohlfarth, Barbara

2000-01-01

The retreat of the Late Weichselian ice sheet over the southern part of Sweden is marked along the southwest coast by distinct marginal moraine ridges. Their timing can directly and indirectly be assessed based on a number of radiocarbon dates and pollen stratigraphic investigations on lake sediment sequences adjacent to the ice marginal lines. Along the southeastern side of the peninsula, the ice recession has been reconstructed based on a combination of clay-varve chronology, pollen and radiocarbon stratigraphy. A morphological correlation of ice marginal lines between the west and east coast is problematic since the distinct west-coast moraines cannot be followed through the central part of the peninsula towards the east coast. This paper is an attempt to reconstruct an age-equivalent west-east extension of the ice-recession lines on the basis of existing data sets. For our correlation we use calibrated radiocarbon ages for ice marginal deposits on the west coast and compare these with a partly radiocarbon-dated clay-varve chronology on the east coast. We conclude that the two oldest moraines on the west coast formed at ˜18,000-16,000 and ˜15,400-14,500 cal yr BP, respectively. During the following rapid deglaciation, which may have coincided with the beginning of the Bølling pollen zone, large parts of southernmost Sweden became ice free, except for higher elevated areas, where stagnant ice remained for another 400-500 yr. A best guess is that the formation of the next younger ice marginal lines may have occurred at ˜14,400-14,200, ˜14,200 and ˜13,400 cal yr BP and during the Younger Dryas cold event.

Cold thermal injury from cold caps used for the prevention of chemotherapy-induced alopecia

PubMed Central

Belum, Viswanath Reddy; de Barros Silva, Giselle; Laloni, Mariana Tosello; Ciccolini, Kathryn; Sklarin, Nancy T.; Lacouture, Mario E.

2017-01-01

INTRODUCTION The use of scalp cooling for the prevention of chemotherapy-induced alopecia (CIA) is increasing. Cold caps are placed onto the hair-bearing areas of the scalp for varying time periods before, during, and after cytotoxic chemotherapy cycles. Although not yet reported, improper application procedures could result in undesirable adverse events (AEs). At present, there are no evidence-based scalp cooling protocols, and there is no regulatory oversight of their use. OBJECTIVE To report the occurrence of cold thermal injury (frostbite) on the scalp, following the use of cold caps for the prevention of CIA. MATERIALS AND METHODS We identified four patients who developed cold thermal injuries on the scalp following the application of cold caps. Medical records were analyzed to retrieve the demographic, clinical, and histologic characteristics. RESULTS The cold thermal injuries in our patients were grade 1/2 in severity and improved with topical interventions, although mild persistent alopecia ensued in 3 patients. The true incidence of such injuries in this setting however, remains unknown. CONCLUSIONS Cold thermal cold injuries are likely an infrequent and preventable AE that may result from improper device application procedures during scalp cooling. Although these untoward events are usually mild to moderate in severity, the potential occurrence of long-term sequelae (e.g. permanent alopecia, scarring) are not known. Future prospective studies are needed to further elucidate the risk and standardized delivery methods, and patient/clinical education. PMID:27146710

Superficial scald and bitter pit development in cold-stored transgenic apples suppressed for ethylene biosynthesis.

PubMed

Pesis, Edna; Ibáñez, Ana M; Phu, My Lin; Mitcham, Elizabeth J; Ebeler, Susan E; Dandekar, Abhaya M

2009-04-08

The plant hormone ethylene regulates climacteric fruit ripening and plays a major role in the development of superficial scald in apple fruits during cold storage. The effect of cold storage at 0 degrees C on development of superficial scald and bitter pit (BP) in transgenic Greensleeves (GS) apples suppressed for ethylene biosynthesis was investigated. Four apple lines were used: untransformed GS; line 68G, suppressed for 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO); and lines 103Yand 130Y, suppressed for ACC synthase (ACS). Fruits from the transformed lines 68G, 103Y, and 130Y produced very little ethylene during 3 months of cold storage at 0 degrees C and after subsequent transfer to 20 degrees C, whereas untransformed fruits produced significant ethylene during cold storage, which increased dramatically at 20 degrees C. Respiration, expressed as CO(2) production, was similar in all four apple lines. After 2 months at 0 degrees C, all apple lines showed some BP symptoms, but lines 68G and 103Y were more affected than untransformed GS or line 130Y. Both transformed and untransformed apples produced alpha-farnesene, but concentrations were lower in yellow fruit than in green fruit in all lines but 68G. Line 68G produced the most alpha-farnesene after 2 months at 0 degrees C, including both (E,E) alpha-farnesene and (Z,E) alpha-farnesene. Concentrations of (E,E) alpha-farnesene were 100 times greater than those of (Z,E) alpha-farnesene in all lines. After 4 months at 0 degrees C plus 1 week at 20 degrees C, untransformed GS apples exhibited the most superficial scald, whereas fruits from lines 68G and 103Y were less affected and line 130Y had no scald. Superficial scald severity was higher in green fruit than in yellow fruit in all affected lines. These lines also exhibited significant production of 6-methyl-5-hepten-2-one (MHO), a major oxidation product of (E,E) alpha-farnesene. Line 130Y neither exhibited superficial scald nor produced MHO. It is shown here that even transgenic apples suppressed for ethylene biosynthesis genes can produce alpha-farnesene, which in turn can oxidize to free radicals and MHO, leading to scald development.

Three-dimensional circulation structures leading to heavy summer rainfall over central North China

NASA Astrophysics Data System (ADS)

Sun, Wei; Yu, Rucong; Li, Jian; Yuan, Weihua

2016-04-01

Using daily and hourly rain gauge records and Japanese 25 year reanalysis data over 30 years, this work reveals two major circulation structures leading to heavy summer rainfall events in central North China (CNC), and further analyzes the effects of the circulations on these rainfall events. One circulation structure has an extensive upper tropospheric warm anomaly (UTWA) covering North China (NC). By strengthening the upper anticyclonic anomaly and lower southerly flows around NC, the UTWA plays a positive role in forming upper level divergence and lower level moisture convergence. As a result, the warm anomalous circulation has a solid relationship with large-scale, long-duration rainfall events with a diurnal peak around midnight to early morning. The other circulation structure has an upper tropospheric cold anomaly (UTCA) located in the upper stream of NC. Contributed to by the UTCA, a cold trough appears in the upper stream of NC and an unstable configuration with upper (lower) cold (warm) anomalies forms around CNC. Consequently, CNC is covered by strong instability and high convective energy, and the cold anomalous circulation is closely connected with local, short-duration rainfall events concentrated from late afternoon to early nighttime. The close connections between circulation structures and typical rainfall events are confirmed by two independent converse analysis processes: from circulations to rainfall characteristics, and from typical rainfall events to circulations. The results presented in this work indicate that the upper tropospheric temperature has significant influences on heavy rainfall, and thus more attention should be paid to the upper tropospheric temperature in future analyses.

Effects of cold-acclimation on gene expression in Fall field cricket (Gryllus pennsylvanicus) ionoregulatory tissues.

PubMed

Des Marteaux, Lauren E; McKinnon, Alexander H; Udaka, Hiroko; Toxopeus, Jantina; Sinclair, Brent J

2017-05-08

Cold tolerance is a key determinant of temperate insect distribution and performance. Chill-susceptible insects lose ion and water homeostasis during cold exposure, but prior cold acclimation improves both cold tolerance and defense of homeostasis. The mechanisms underlying these processes are mostly unknown; cold acclimation is thought to enhance ion transport in the cold and/or prevent leak of water and ions. To identify candidate mechanisms of cold tolerance plasticity we generated transcriptomes of ionoregulatory tissues (hindgut and Malpighian tubules) from Gryllus pennsylvanicus crickets and compared gene expression in warm- and cold-acclimated individuals. We assembled a G. pennsylvanicus transcriptome de novo from 286 million 50-bp reads, yielding 70,037 contigs (~44% of which had putative BLAST identities). We compared the transcriptomes of warm- and cold-acclimated hindguts and Malpighian tubules. Cold acclimation led to a ≥ 2-fold change in the expression of 1493 hindgut genes (733 downregulated, 760 upregulated) and 2008 Malpighian tubule genes (1009 downregulated, 999 upregulated). Cold-acclimated crickets had altered expression of genes putatively associated with ion and water balance, including: a downregulation of V-ATPase and carbonic anhydrase in the Malpighian tubules and an upregulation of Na + -K + ATPase in the hindgut. We also observed acclimation-related shifts in the expression of cytoskeletal genes in the hindgut, including actin and actin-anchoring/stabilizing proteins, tubulin, α-actinin, and genes involved in adherens junctions organization. In both tissues, cold acclimation led to differential expression of genes encoding cytochrome P450s, glutathione-S-transferases, apoptosis factors, DNA repair, and heat shock proteins. This is the first G. pennsylvanicus transcriptome, and our tissue-specific approach yielded new candidate mechanisms of cold tolerance plasticity. Cold acclimation may reduce loss of hemolymph volume in the cold by 1) decreasing primary urine production via reduced expression of carbonic anhydrase and V-ATPase in the Malpighian tubules and 2) by increasing Na + (and therefore water) reabsorption across the hindgut via increase in Na + -K + ATPase expression. Cold acclimation may reduce chilling injury by remodeling and stabilizing the hindgut epithelial cytoskeleton and cell-to-cell junctions, and by increasing the expression of genes involved in DNA repair, detoxification, and protein chaperones.

North Atlantic storm driving of extreme wave heights in the North Sea

NASA Astrophysics Data System (ADS)

Bell, R. J.; Gray, S. L.; Jones, O. P.

2017-04-01

The relationship between storms and extreme ocean waves in the North Sea is assessed using a long-period wave data set and storms identified in the Interim ECMWF Re-Analysis (ERA-Interim). An ensemble sensitivity analysis is used to provide information on the spatial and temporal forcing from mean sea-level pressure and surface wind associated with extreme ocean wave height responses. Extreme ocean waves in the central North Sea arise due to intense extratropical cyclone winds from either the cold conveyor belt (northerly-wind events) or the warm conveyor belt (southerly-wind events). The largest wave heights are associated with northerly-wind events which tend to have stronger wind speeds and occur as the cold conveyor belt wraps rearward round the cyclone to the cold side of the warm front. The northerly-wind events provide a larger fetch to the central North Sea to aid wave growth. Southerly-wind events are associated with the warm conveyor belts of intense extratropical cyclones that develop in the left upper tropospheric jet exit region. Ensemble sensitivity analysis can provide early warning of extreme wave events by demonstrating a relationship between wave height and high pressure to the west of the British Isles for northerly-wind events 48 h prior. Southerly-wind extreme events demonstrate sensitivity to low pressure to the west of the British Isles 36 h prior.

No difference in acute effects of supplemental v. dietary calcium on blood pressure and microvascular function in obese women challenged with a high-fat meal: a cross-over randomised study.

PubMed

Ferreira, Thaís da Silva; Leal, Priscila Mansur; Antunes, Vanessa Parada; Sanjuliani, Antonio Felipe; Klein, Márcia Regina Simas Torres

2016-11-01

Recent studies suggest that supplemental Ca (SC) increases the risk of cardiovascular events, whereas dietary Ca (DC) decreases the risk of cardiovascular events. Although frequently consumed with meals, it remains unclear whether Ca can mitigate or aggravate the deleterious effects of a high-fat meal on cardiovascular risk factors. This study aimed to evaluate the effects of SC or DC on blood pressure (BP) and microvascular function (MVF) in the postprandial period in obese women challenged with a high-fat meal. In this cross-over controlled trial, sixteen obese women aged 20-50 years were randomly assigned to receive three test meals (2908 kJ (695 kcal); 48 % fat): high DC (HDCM; 547 mg DC), high SC (HSCM; 500 mg SC-calcium carbonate) and low Ca (LCM; 42 mg DC). BP was continuously evaluated from 15 min before to 120 min after meals by digital photoplethysmography. Before and 120 min after meals, participants underwent evaluation of serum Ca and microvascular flow after postocclusive reactive hyperaemia (PORH) by laser speckle contrast imaging. Ionised serum Ca rose significantly only after HSCM. Systolic BP increased after the three meals, whereas diastolic BP increased after LCM and HDCM. Hyperaemia peak, hyperaemia amplitude and AUC evaluated after PORH decreased with LCM. After HDCM, there was a reduction in hyperaemia peak and hyperaemia amplitude, whereas HSCM decreased only hyperaemia peak. However, comparative analyses of the effects of three test meals on serum Ca, BP and MVF revealed no significant meal×time interaction. This study suggests that in obese women SC and DC do not interfere with the effects of a high-fat meal on BP and MVF.

Autoantibodies to BP180 associated with bullous pemphigoid release interleukin-6 and interleukin-8 from cultured human keratinocytes.

PubMed

Schmidt, E; Reimer, S; Kruse, N; Jainta, S; Bröcker, E B; Marinkovich, M P; Giudice, G J; Zillikens, D

2000-11-01

Bullous pemphigoid is an inflammatory subepidermal blistering disease that is associated with auto- antibodies to the keratinocyte surface protein, BP180. In addition to the binding of autoantibodies, the infiltration of inflammatory cells is necessary for blister formation. Cytokines, including interleukin-6 and interleukin-8, have been implicated in the disease process of both human and experimental murine bullous pemphigoid. This study was aimed at testing the hypothesis that the binding of anti-BP180 antibodies to their target antigen triggers a signal transduction event that results in the secretion of these pro-inflammatory cytokines. Consistent with this hypothesis, treatment of cultured normal human epidermal keratinocytes with bullous pemphigoid IgG, but not control IgG, led to increased levels of interleukin-6 and interleukin-8, but not interleukin-1alpha, interleukin-1beta, tumor necrosis factor-alpha, interleukin-10, or monocyte chemoattractant protein-1, in the culture medium. This effect was concentration- and time-dependent and was abolished by depleting the bullous pemphigoid IgG of reactivity to two distinct epitopes on the BP180 NC16A domain. Upregulation of interleukin-6 and interleukin-8 was found at both protein and mRNA levels. In addition, bullous pemphigoid IgG did not induce the release of interleukin-6 and interleukin-8 from BP180-deficient keratinocytes obtained from a patient with generalized atrophic benign epidermolysis bullosa. These data indicate that bullous pemphigoid-associated autoantibodies to the human BP180 ectodomain trigger a signal transducing event that leads to expression and secretion of interleukin-6 and interleukin-8 from human keratinocytes.

Night-time heart rate nondipping: clinical and prognostic significance in the general population.

PubMed

Cuspidi, Cesare; Facchetti, Rita; Bombelli, Michele; Sala, Carla; Tadic, Marijana; Grassi, Guido; Mancia, Giuseppe

2018-06-01

Studies addressing the association between a reduced drop of heart rate (HR) at night with subclinical organ damage and cardiovascular events in the general population are scanty. We evaluated this issue in individuals enrolled in the Pressioni Monitorate E Loro Associazioni study. At entry, 2021 individuals underwent diagnostic tests including laboratory investigations, 24-h ambulatory blood pressure (BP) monitoring and echocardiography. Participants were followed from the initial medical visit for a time interval of 148 ± 27 months. To explore the association of circadian HR rhythm and outcomes, participants were classified in the primary analysis according to quartiles of nocturnal HR decrease. In secondary analyses, the population was also classified according nondipping nocturnal HR (defined as a drop in average HR at night lower than 10% compared with day-time values) and next in four categories: first, BP/HR dipper, second, BP/HR nondipper, third, HR dipper/BP nondipper, fourth, HR nondipper/BP dipper). A flattened circadian HR rhythm (i.e. lowest quartile of night-time HR dip) was independently associated with left atrial enlargement, but not to left ventricular hypertrophy; moreover, it was predictive of fatal and nonfatal cardiovascular events, independently of several confounders (hazard ratio 1.8, confidence interval: 1.13-2.86, P < 0.01 vs. highest quartile). A blunted dipping of nocturnal HR is associated with preclinical cardiac damage in terms of left atrial enlargement and is predictive cardiovascular morbidity and mortality in the general population.

Late Quaternary Climate and Vegetation of the Sudanian Zone of Northeast Nigeria

NASA Astrophysics Data System (ADS)

Salzmann, Ulrich; Hoelzmann, Philipp; Morczinek, Irena

2002-07-01

The Lake Tilla crater lake in northeastern Nigeria (10°23'N, 12°08'E) provides a ca. 17,000 14C yr multiproxy record of the environmental history of a Sudanian savanna in West Africa. Evaluation of pollen, diatoms, and sedimentary geochemistry from cores suggests that dry climatic conditions prevailed throughout the late Pleistocene. Before the onset of the Holocene, the slow rise in lake levels was interrupted by a distinct dry event between ca. 10,900 and 10,500 14C yr B.P., which may coincide with the Younger Dryas episode. The onset of the Holocene is marked by an abrupt increase in lake levels and a subsequent spread of Guinean and Sudanian tree taxa into the open grass savanna that predominated throughout the Late Pleistocene. The dominance of the mountain olive Olea hochstetteri suggests cool climatic conditions prior to ca. 8600 14C yr B.P. The early to mid-Holocene humid period culminated between ca. 8500 and 7000 14C yr B.P. with the establishment of a dense Guinean savanna during high lake levels. Frequent fires were important in promoting the open character of the vegetation. The palynological and palaeolimnological data demonstrate that the humid period terminated after ca. 7000 14C yr B.P. in a gradual decline of the precipitation/evaporation ratio and was not interrupted by abrupt climatic events. The aridification trend intensified after ca. 3800 14C yr B.P. and continued until the present.

6-kyr record of flood frequency and intensity in the western Mediterranean Alps - Interplay of solar and temperature forcing

NASA Astrophysics Data System (ADS)

Sabatier, Pierre; Wilhelm, Bruno; Ficetola, Gentile Francesco; Moiroux, Fanny; Poulenard, Jérôme; Develle, Anne-Lise; Bichet, Adeline; Chen, Wentao; Pignol, Cécile; Reyss, Jean-Louis; Gielly, Ludovic; Bajard, Manon; Perrette, Yves; Malet, Emmanuel; Taberlet, Pierre; Arnaud, Fabien

2017-08-01

The high-resolution sedimentological and geochemical analysis of a sediment sequence from Lake Savine (Western Mediterranean Alps, France) led to the identification of 220 event layers for the last 6000 years. 200 were triggered by flood events and 20 by underwater mass movements possibly related to earthquakes that occurred in 5 clusters of increase seismicity. Because human activity could influence the flood chronicle, the presence of pastures was reconstructed through ancient DNA, which suggested that the flood chronicle was mainly driven by hydroclimate variability. Weather reanalysis of historical floods allow to identify that mesoscale precipitation events called "East Return" events were the main triggers of floods recorded in Lake Savine. The first part of this palaeoflood record (6-4 kyr BP) was characterized by increases in flood frequency and intensity in phase with Northern Alpine palaeoflood records. By contrast, the second part of the record (i.e., since 4 kyr BP) was phased with Southern Alpine palaeoflood records. These results suggest a palaeohydrological transition at approximately 4 kyr BP, as has been previously described for the Mediterranean region. This may have resulted in a change of flood-prone hydro-meteorological processes, i.e., in the balance between occurrence and intensity of local convective climatic phenomena and their influence on Mediterranean mesoscale precipitation events in this part of the Alps. At a centennial timescale, increases in flood frequency and intensity corresponded to periods of solar minima, affecting climate through atmospheric changes in the Euro-Atlantic sector.

Safety and efficacy of over-the-counter cough and cold medicines for use in children.

PubMed

Vassilev, Zdravko P; Kabadi, Shaum; Villa, Raul

2010-03-01

Over-the-counter (OTC) cough and cold medications have been used widely for years and continue to be a preferred choice for temporary relief of symptoms of upper respiratory tract infections in children. These medications are being placed under extraordinary scrutiny in the pediatric population due to the lack of conclusive evidence about their therapeutic efficacy and increased reports of associations with serious adverse events and even mortality. A PubMed search was conducted to identify articles published up to August 2009 describing the efficacy and safety of OTC cough and cold medications in children. The objective was to provide an overview of the relevant literature and regulatory history and to comment on the available data on this important topic. The paper provides a detailed up-to-date review of the key efficacy and safety studies published on the subject. In addition, the reader is presented with an overview of the regulatory history and recent developments surrounding the use of OTC cough and cold medications in children in the US. This review confirms the lack of efficacy of OTC cough and cold products in children and reaffirms that although the overall incidence of related serious adverse events is low, such events continue to occur. The conclusions in this paper support a recommendation that OTC cough and cold medications should not be given to infants and very young children. Furthermore, additional research is needed to evaluate the safety and efficacy of these medicines in the broader pediatric population.

Blood pressure response to CPAP treatment in subjects with obstructive sleep apnoea: the predictive value of 24-h ambulatory blood pressure monitoring.

PubMed

Castro-Grattoni, Anabel L; Torres, Gerard; Martínez-Alonso, Montserrat; Barbé, Ferran; Turino, Cecilia; Sánchez-de-la-Torre, Alicia; Cortijo, Anunciacion; Duran-Cantolla, Joaquin; Egea, Carlos; Cao, Gonzalo; Sánchez-de-la-Torre, Manuel

2017-10-01

The reduction in blood pressure (BP) with continuous positive airway pressure (CPAP) is modest and highly variable. In this study, we identified the variables that predict BP response to CPAP.24-h ambulatory BP monitoring (ABPM), C-reactive protein (CRP), leptin, adiponectin and 24-h urinary catecholamine were measured before and after 6 months of CPAP in obstructive sleep apnoea (OSA) patients.Overall, 88 middle-aged, obese male patients with severe OSA (median apnoea-hypopnoea index 42 events·h -1 ) were included; 28.4% had hypertension. 62 patients finished the study, and 60 were analysed. The daytime diastolic BP (-2 mmHg) and norepinephrine (-109.5 nmol·day -1 ) were reduced after CPAP, but no changes in the 24-h BP, night-time BP, dopamine, epinephrine, CRP, leptin or adiponectin were detected. The nocturnal normotension was associated with an increased night-time-BP (+4 mmHg) after CPAP, whereas nocturnal hypertension was associated with a reduction of 24-h BP (-3 mmHg). A multivariate linear regression model showed differential night-time BP changes after CPAP. Specifically, low night-time heart rate (<68 bpm) and BP dipper profile were associated with increased night-time BP and new diagnosis of nocturnal hypertension.Our results suggest that nocturnal hypertension, circadian BP pattern and night-time heart rate could be clinical predictors of BP response to CPAP and support the usefulness of 24-h ABPM for OSA patients before treatment initiation. These results need to be confirmed in further studies. Copyright ©ERS 2017.

A new Late Weichselian and Holocene marine chronology for the western Svalbard slope 30,000-0 cal years BP

NASA Astrophysics Data System (ADS)

Jessen, Simon P.; Rasmussen, Tine L.; Nielsen, Tove; Solheim, Anders

2010-05-01

Data have been compiled from eleven sediment cores from 76° to 80°N on the western Svalbard slope. The cores are from water depths between 630 and 1880 m and show clear similarities in lithology and magnetic susceptibility. All cores penetrated into mass transported sediments from glacigenic debris flow events and turbidity flow events. The mass transport probably occurred when the ice reached the shelf edge. The deposits date between 24,080 ± 150 and 23,550 ± 185 calibrated (cal) years BP. The records also include laminated, fine grained sediments interpreted as deposits from sediment-laden meltwater plumes dated between 14,780 ± 220 and 14,300 ± 260 cal years BP. In Holocene sediments a diatom-rich fine grained layer dates 10,100 ± 150 to 9840 ± 200 cal years BP. The eleven cores have been stacked into one record with absolute age control from 35 AMS 14C dates. Together with oxygen isotope stratigraphy and contents of ice rafted detritus the stacked record provides a useful chronology tool for cores on the western Svalbard slope. Our study improves the age control of earlier well documented glacial events and shows that the maximum glacial state and the onset of the deglaciation both occurred 2500-3000 years earlier than previously reconstructed for the western Svalbard margin. The results indicate that during the last 30,000 years advance and retreat of the Svalbard-Barents Sea Ice Sheet was closely linked to the flow of Atlantic Water and Polar Water over the margin.

Oxygen-dependent acetylation and dimerization of the corepressor CtBP2 in neural stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karaca, Esra; Lewicki, Jakub; Hermanson, Ola, E-mail: Ola.Hermanson@ki.se

2015-03-01

The transcriptional corepressor CtBP2 is essential for proper development of the nervous system. The factor exerts its repression by interacting in complexes with chromatin-modifying factors such as histone deacetylases (HDAC) 1/2 and the histone demethylase LSD1/KDM1. Notably, the histone acetyl transferase p300 acetylates CtBP2 and this is an important regulatory event of the activity and subcellular localization of the protein. We recently demonstrated an essential role for CtBPs as sensors of microenvironmental oxygen levels influencing the differentiation potential of neural stem cells (NSCs), but it is not known whether oxygen levels influence the acetylation levels of CtBP factors. Here wemore » show by using proximity ligation assay (PLA) that CtBP2 acetylation levels increased significantly in undifferentiated, proliferating NSCs under hypoxic conditions. CtBP2 interacted with the class III HDAC Sirt1 but this interaction was unaltered in hypoxic conditions, and treatment with the Sirt1 inhibitor Ex527 did not result in any significant change in total CtBP2 acetylation levels. Instead, we revealed a significant decrease in PLA signal representing CtBP2 dimerization in NSCs under hypoxic conditions, negatively correlating with the acetylation levels. Our results suggest that microenvironmental oxygen levels influence the dimerization and acetylation levels, and thereby the activity, of CtBP2 in proliferating NSCs.« less

Regulation of circadian blood pressure: from mice to astronauts.

PubMed

Agarwal, Rajiv

2010-01-01

Circadian variation is commonly seen in healthy people; aberration in these biological rhythms is an early sign of disease. Impaired circadian variation of blood pressure (BP) has been shown to be associated with greater target organ damage and with an elevated risk of cardiovascular events independent of the BP load. The purpose of this review is to examine the physiology of circadian BP variation and propose a tripartite model that explains the regulation of circadian BP. The time-keeper in mammals resides centrally in the suprachiasmatic nucleus. Apart from this central clock, molecular clocks exist in most peripheral tissues including vascular tissue and the kidney. These molecular clocks regulate sodium balance, sympathetic function and vascular tone. A physiological model is proposed that integrates our understanding of molecular clocks in mice with the circadian BP variation among humans. The master regulator in this proposed model is the sleep-activity cycle. The equivalents of peripheral clocks are endothelial and adrenergic functions. Thus, in the proposed model, the variation in circadian BP is dependent upon three major factors: physical activity, autonomic function, and sodium sensitivity. The integrated consideration of physical activity, autonomic function, and sodium sensitivity appears to explain the physiology of circadian BP variation and the pathophysiology of disrupted BP rhythms in various conditions and disease states. Our understanding of molecular clocks in mice may help to explain the provenance of blunted circadian BP variation even among astronauts.

Serum levels of IGF-1 and IGF-BP3 are associated with event-free survival in adult Ewing sarcoma patients treated with chemotherapy.

PubMed

de Groot, Stefanie; Gelderblom, Hans; Fiocco, Marta; Bovée, Judith Vmg; van der Hoeven, Jacobus Jm; Pijl, Hanno; Kroep, Judith R

2017-01-01

Activation of the insulin-like growth factor 1 (IGF-1) pathway is involved in cell growth and proliferation and is associated with tumorigenesis, tumor progression, and therapy resistance in solid tumors. We examined whether variability in serum levels of IGF-1, IGF-2, and IGF-binding protein 3 (IGF-BP3) can predict event-free survival (EFS) and overall survival (OS) in Ewing sarcoma patients treated with chemotherapy. Serum levels of IGF-1, IGF-2, and IGF-BP3 of 22 patients with localized or metastasized Ewing sarcoma treated with six cycles of vincristine/ifosfamide/doxorubicin/etoposide (VIDE) chemotherapy were recorded. Baseline levels were compared with presixth cycle levels using paired t -tests and were tested for associations with EFS and OS. Continuous variables were dichotomized according to the Contal and O'Quigley procedure. Survival analyses were performed using Cox regression analysis. High baseline IGF-1 and IGF-BP3 serum levels were associated with EFS (hazard ratio [HR] 0.075, 95% confidence interval [CI] 0.009-0.602 and HR 0.090, 95% CI 0.011-0.712, respectively) in univariate and multivariate analyses (HR 0.063, 95% CI 0.007-0.590 and HR 0.057, 95% CI 0.005-0.585, respectively). OS was improved, but this was not statistically significant. IGF-BP3 and IGF-2 serum levels increased during treatment with VIDE chemotherapy ( P =0.055 and P =0.023, respectively). High circulating serum levels of IGF-1 and IGF-BP3 and the molar ratio of IGF-1:IGF-BP3 serum levels were associated with improved EFS and a trend for improved OS in Ewing sarcoma patients treated with VIDE chemotherapy. These findings suggest the need for further investigation of the IGF-1 pathway as a biomarker of disease progression in patients with Ewing sarcoma.

Day-by-Day Variability of Home Blood Pressure and Incident Cardiovascular Disease in Clinical Practice: The J-HOP Study (Japan Morning Surge-Home Blood Pressure).

PubMed

Hoshide, Satoshi; Yano, Yuichiro; Mizuno, Hiroyuki; Kanegae, Hiroshi; Kario, Kazuomi

2018-01-01

We assessed the relationship between day-by-day home blood pressure (BP) variability and incident cardiovascular disease (CVD) in clinical practice. J-HOP study (Japan Morning Surge-Home Blood Pressure) participants underwent home BP monitoring in the morning and evening for a 14-day period, and their BP levels and BP variability independent of the mean (VIM) were assessed. Incident CVD events included coronary heart disease and stroke. Cox models were fitted to assess the home BP variability-CVD risk association. Among 4231 participants (mean±SD age, 64.9±10.9 years; 53.3% women; 79.1% taking antihypertensive medication), mean (SD) home systolic BP (SBP) levels over time and VIM SBP were 134.2 (14.3) and 6.8 (2.5) mm Hg, respectively. During a 4-year follow-up period (16 750.3 person-years), 148 CVD events occurred. VIM SBP was associated with CVD risk (hazard ratio per 1-SD increase, 1.32; 95% confidence interval [CI], 1.15-1.52), independently of mean home SBP levels over time and circulating B-type natriuretic peptide levels or urine albumin-to-creatinine ratio. Adding VIM SBP to the CVD prediction model improved the discrimination (C statistic, 0.785 versus 0.770; C statistic difference, 0.015; 95% CI, 0.003-0.028). Changes in continuous net reclassification improvement (0.259; 95% CI, 0.052-0.537), absolute integrated discrimination improvement (0.010; 95% CI, 0.003-0.016), and relative integrated discrimination improvement (0.104; 95% CI, 0.037-0.166) were also observed with the addition of VIM SBP to the CVD prediction models. In addition to the assessments of mean home SBP levels and cardiovascular end-organ damage, home BP variability measurements may provide a clinically useful distinction between high- and low-risk groups among Japanese outpatients. © 2017 American Heart Association, Inc.

Interplay between Amazonia Tropical Rain Forest Fires (Mesoscale distribution) and global carbon cycle

NASA Astrophysics Data System (ADS)

Cordeiro, R. C.; Turcq, B.; Sifeddine, A.

2009-12-01

Soil samples were collected at 9 different depths, from zero to 100 cm at six points distributed along a transect of 1700 m in upland and lowland areas of the Km 41 reserve near Manaus in Central Brazilian Amazonia, in order to compare the frequency, dimension and extension of past fires in different topographic environmental situations. The average charcoal mass distribution is higher in uplands than in lowlands. This distribution shows a gradient with a high correlation between the two topographic levels, demonstrating a characteristic depth distribution pattern. The highest charcoal concentrations were found at a depth of 20-50 cm in all the six profiles. These fires have affected the upland areas more severely than the lowlands, probably allowing the survival of the vegetation along the small streams.. Two periods of intense fire activity were identified through the distribution of the biomass of charcoal: from around 1320 cal yr BP (ca 1400 14C yr BP) to 1050 cal yr BP (ca 1100 14C yr BP), and between 610 cal yr BP (ca 600 14C yr BP) to 330 cal yr BP (ca 300 yr 14C yr BP). These forest fire phases were probably favored by dry climate which is recorded in other regions of Amazonia and South America by archaeological and palaeoecological data.. Observe that the data found in this article related to the disturbances of fire events in the Central Amazon region appear to be synchronous with events of disruption of populations and vegetation changes and background to the development of indigenous people. Thus it seems plausible that these disturbance phenomena may have an origin presumably climatic than anthropogenic. This possible relationship between climate and forest, ecosystems of high productivity and biomass, and humans should be look carefully in relation to the carbon cycle dynamics demonstrated by the air bubbles extracted of the ice core records.. Increase is observed in the CO2 concentration of the Taylor Dome record just after the increase in frequency and biomass burning at 1350 cal yr BP. The maximum increase of CO2, during the Holocene, is higher at 1220 cal yr BP almost simultaneously with the highest frequency of occurrence of charcoal/biomass of charcoal between 1350 and 1100 cal yr BP. Based on the present-day and future trend of drier climate and more irregular precipitation in this region, the frequency of Amazonian rainforest fires tend to increase and to may have an impact on the CO2 future global cycle.

Responses to the 2800 years BP climatic oscillation in shallow- and deep-basin sediments from the Dead Sea

NASA Astrophysics Data System (ADS)

Neugebauer, Ina; Brauer, Achim; Schwab, Markus; Dulski, Peter; Frank, Ute; Hadzhiivanova, Elitsa; Kitagawa, Hiroyuki; Litt, Thomas; Schiebel, Vera; Taha, Nimer; Waldmann, Nicolas

2015-04-01

Laminated lake sediments from the Dead Sea basin provide high-resolution records of climatic variability in the eastern Mediterranean region, which is considered being especially sensitive to changing climatic conditions. In the study presented here, we aim to reconstruct palaeoclimatic changes and their relation to the frequency of flood/erosion and dust deposition events as archived in the Dead Sea basin for the time interval from ca 3700 to 1700 years BP. A ca 4 m thick, mostly annually laminated (varved) sediment section from the western margin of the Dead Sea (shallow-water DSEn - Ein Gedi profile) was analysed and correlated to the new ICDP Dead Sea Deep Drilling Project core 5017-1 from the deep basin. To detect even single event layers, we applied a multi-proxy approach of high-resolution microscopic thin section analyses, µXRF element scanning and magnetic susceptibility measurements, supported by grain size and palynological analyses. Based on radiocarbon and varve dating two pronounced dry periods were detected at ~3500-3300 yrs BP and ~2900-2400 yrs BP that are characterized by a sand deposit during the older dry period and enhanced frequency of coarse detrital layers during the younger dry period in the shallow-water DSEn core, both interpreted as increased erosion processes. In the 5017-1 deep-basin core these dry periods are depicted by halite deposits. The timing of the younger dry period broadly coincides with the Homeric Minimum of solar activity at ca 2800 yrs BP. Our results suggest that during this period the Dead Sea region experienced a change in synoptic weather patterns leading to an increased occurrence of flash-flood events, overprinting the overall dry climatic conditions. Following this dry spell, a 250-yrs period of increased dust deposition is observed, coinciding with more regular aragonite precipitation during less arid climatic conditions.

Altered cropping pattern and cultural continuation with declined prosperity following abrupt and extreme arid event at ~4,200 yrs BP: Evidence from an Indus archaeological site Khirsara, Gujarat, western India

PubMed Central

Pokharia, Anil K.; Sharma, Shalini; Bajpai, Sunil; Nath, Jitendra; Kumaran, R. N.; Negi, Bipin Chandra

2017-01-01

Archaeological sites hold important clues to complex climate-human relationships of the past. Human settlements in the peripheral zone of Indus culture (Gujarat, western India) are of considerable importance in the assessment of past monsoon-human-subsistence-culture relationships and their survival thresholds against climatic stress exerted by abrupt changes. During the mature phase of Harappan culture between ~4,600–3,900yrsBP, the ~4,100±100yrsBP time slice is widely recognized as one of the major, abrupt arid-events imprinted innumerous well-dated palaeo records. However, the veracity of this dry event has not been established from any archaeological site representing the Indus (Harappan) culture, and issues concerning timing, changes in subsistence pattern, and the likely causes of eventual abandonment (collapse) continue to be debated. Here we show a significant change in crop-pattern (from barley-wheat based agriculture to ‘drought-resistant’ millet-based crops) at ~4,200 yrs BP, based on abundant macrobotanical remains and C isotopes of soil organic matter (δ13CSOM) in an archaeological site at Khirsara, in the Gujarat state of western India. The crop-change appears to be intentional and was likely used as an adaptation measure in response to deteriorated monsoonal conditions. The ceramic and architectural remains of the site indicate that habitation survived and continued after the ~4,200yrsBP dry climatic phase, but with declined economic prosperity. Switching to millet-based crops initially helped inhabitants to avoid immediate collapse due to climatic stresses, but continued aridity and altered cropping pattern led to a decline in prosperity levels of inhabitants and eventual abandonment of the site at the end of the mature Harappan phase. PMID:28985232

Molecular characterizations of DNA methyltransferase 3 and its roles in temperature tolerance in the whitefly, Bemisia tabaci Mediterranean.

PubMed

Dai, T-M; Lü, Z-C; Wang, Y-S; Liu, W-X; Hong, X-Y; Wan, F-H

2018-02-01

The Bemisia tabaci Mediterranean (MED) cryptic species is an invasive pest, distributed worldwide, with high ecological adaptability and thermotolerance. DNA methylation (a reversible chromatin modification) is one possible change that may occur within an organism subjected to environmental stress. To assess the effects of temperature stress on DNA methyltransferase 3 (Dnmt3) in MED, we cloned and sequenced BtDnmt3 and identified its functions in response to high and low temperatures. The full-length cDNA of BtDnmt3 was 3913 bp, with an open reading frame of 1962 bp, encoding a 73.89 kDa protein. In situ hybridization showed that BtDnmt3 was expressed mainly in the posterior region. BtDnmt3 messenger RNA expression levels were significantly down-regulated after exposure to heat shock and significantly up-regulated after exposure to cold shock. Furthermore, after feeding on double-stranded RNA specific for BtDnmt3, both heat resistance and cold resistance were significantly decreased, suggesting that BtDnmt3 is associated with thermal stress response and indicating a differential response to high- and low-temperature stress in MED. Together, these results highlight a potential role for DNA methylation in thermal resistance, which is a process important to successful invasion and colonization of an alien species in various environments. © 2017 The Royal Entomological Society.

Mitogenome rearrangement in the cold-water scleractinian coral Lophelia pertusa (Cnidaria, Anthozoa) involves a long-term evolving group I intron.

PubMed

Emblem, Åse; Karlsen, Bård Ove; Evertsen, Jussi; Johansen, Steinar D

2011-11-01

Group I introns are genetic insertion elements that invade host genomes in a wide range of organisms. In metazoans, however, group I introns are extremely rare, so far only identified within mitogenomes of hexacorals and some sponges. We sequenced the complete mitogenome of the cold-water scleractinian coral Lophelia pertusa, the dominating deep sea reef-building coral species in the North Atlantic Ocean. The mitogenome (16,150 bp) has the same gene content but organized in a unique gene order compared to that of other known scleractinian corals. A complex group I intron (6460 bp) inserted in the ND5 gene (position 717) was found to host seven essential mitochondrial protein genes and one ribosomal RNA gene. Phylogenetic analysis supports a vertical inheritance pattern of the ND5-717 intron among hexacoral mitogenomes with no examples of intron loss. Structural assessments of the Lophelia intron revealed an unusual organization that lacks the universally conserved ωG at the 3' end, as well as a highly compact RNA core structure with overlapping ribozyme and protein coding capacities. Based on phylogenetic and structural analyses we reconstructed the evolutionary history of ND5-717, from its ancestral protist origin, through intron loss in some early metazoan lineages, and into a compulsory feature with functional implications in hexacorals. Copyright © 2011 Elsevier Inc. All rights reserved.

Yearly variation of bacterial production in the Arraial do Cabo protection area (Cabo Frio upwelling region): An evidence of anthropogenic pressure

PubMed Central

Coelho-Souza, Sérgio A.; Pereira, Gilberto C.; Coutinho, Ricardo; Guimarães, Jean R.D.

2013-01-01

Arraial do Cabo is where upwelling occurs more intensively on the Brazilian coast. Although it is a protection area it suffers anthropogenic pressure such as harbor activities and sporadic sewage emissions. Short-time studies showed a high variability of bacterial production (BP) in this region but none of them evaluated BP during long periods in a large spatial scale including stations under different natural (upwelling and cold fronts) and anthropogenic pressures. During 2006, we sampled surface waters 10 times (5 in upwelling and 5 in subsidence periods) in 8 stations and we measured BP, temperature as well as the concentrations of inorganic nutrients, pigments and particulate organic matter (POM). BP was up to 400 times higher when sewage emissions were observed visually and it had a positive correlation with ammonia concentrations. Therefore, in 2007, we did two samples (each during upwelling and subsidence periods) during sewage emissions in five stations under different anthropogenic pressure and we also measured particles abundance by flow cytometry. The 12 samples in the most impacted area confirmed that BP was highest when ammonia was higher than 2 μM, also reporting the highest concentrations of chlorophyll a and suspended particles. However, considering all measured variables, upwelling was the main disturbing factor but the pressure of fronts should not be neglected since it had consequences in the auto-heterotrophic coupling, increasing the concentrations of non fluorescent particles and POM. Stations clustered in function of natural and anthropogenic pressures degrees and both determined the temporal-spatial variability. PMID:24688533

Yearly variation of bacterial production in the Arraial do Cabo protection area (Cabo Frio upwelling region): an evidence of anthropogenic pressure.

PubMed

Coelho-Souza, Sérgio A; Pereira, Gilberto C; Coutinho, Ricardo; Guimarães, Jean R D

2013-12-01

Arraial do Cabo is where upwelling occurs more intensively on the Brazilian coast. Although it is a protection area it suffers anthropogenic pressure such as harbor activities and sporadic sewage emissions. Short-time studies showed a high variability of bacterial production (BP) in this region but none of them evaluated BP during long periods in a large spatial scale including stations under different natural (upwelling and cold fronts) and anthropogenic pressures. During 2006, we sampled surface waters 10 times (5 in upwelling and 5 in subsidence periods) in 8 stations and we measured BP, temperature as well as the concentrations of inorganic nutrients, pigments and particulate organic matter (POM). BP was up to 400 times higher when sewage emissions were observed visually and it had a positive correlation with ammonia concentrations. Therefore, in 2007, we did two samples (each during upwelling and subsidence periods) during sewage emissions in five stations under different anthropogenic pressure and we also measured particles abundance by flow cytometry. The 12 samples in the most impacted area confirmed that BP was highest when ammonia was higher than 2 μM, also reporting the highest concentrations of chlorophyll a and suspended particles. However, considering all measured variables, upwelling was the main disturbing factor but the pressure of fronts should not be neglected since it had consequences in the auto-heterotrophic coupling, increasing the concentrations of non fluorescent particles and POM. Stations clustered in function of natural and anthropogenic pressures degrees and both determined the temporal-spatial variability.

Landscape transformations at the dawn of agriculture in southern Syria (10.7-9.9 ka cal. BP): Plant-specific responses to the impact of human activities and climate change

NASA Astrophysics Data System (ADS)

Arranz-Otaegui, Amaia; López-Sáez, José Antonio; Araus, José Luis; Portillo, Marta; Balbo, Andrea; Iriarte, Eneko; Gourichon, Lionel; Braemer, Frank; Zapata, Lydia; Ibáñez, Juan José

2017-02-01

In southwest Asia, the accelerated impact of human activities on the landscape has often been linked to the development of fully agricultural societies during the middle and late Pre-Pottery Neolithic B (PPNB) period (around 10.2-7.9 ka cal. BP). This work contributes to the debate on the environmental impact of the so-called Neolitisation process by identifying the climatic and anthropogenic factors that contributed to change local and regional vegetation at the time when domesticated plants appeared and developed in southern Syria (around 10.7-9.9 ka cal. BP). In this work a multidisciplinary analysis of plant microremains (pollen and phytoliths) and macroremains (wood charcoal) is carried out along with stable carbon isotope discrimination of wood charcoals in an early PPNB site (Tell Qarassa North, west of the Jabal al-Arab area). Prior to 10.5 ka cal. BP, the results indicate a dynamic equilibrium in the local and regional vegetation, which comprised woodland-steppe, Mediterranean evergreen oak-woodlands, wetland vegetation and coniferous forests. Around 10.5-9.9 ka cal. BP, the elements that regulated the vegetation system changed, resulting in reduced proportions of arboreal cover and the spread of cold-tolerant and wetlands species. Our data show that reinforcing interaction between the elements of the anthropogenic (e.g. herding, fire-related activities) and climatic systems (e.g. temperature, rainfall) contributed to the transformation of early Holocene vegetation during the emergence of fully agricultural societies in southern Syria.

Warm ocean surface led to ice margin retreat in central-eastern Baffin Bay during the Younger Dryas

NASA Astrophysics Data System (ADS)

Oksman, Mimmi; Weckström, Kaarina; Miettinen, Arto; Juggins, Stephen; Divine, Dmitry; Jackson, Rebecca; Korsgaard, Niels J.; Telford, Richard; Kucera, Michal

2017-04-01

The Greenland ice sheet stability is linked to fast-flowing ice streams that are influenced by sea surface temperatures (SSTs) at their front. One of the largest ice streams in West Greenland is the Jakobshavn Isbræ, which has been shown to have collapsed at ca. 12.2 kyr BP in the middle of the Younger Dryas (YD) cold period (12.9-11.7 kyr BP). The cause for this collapse is still unknown yet hypotheses, such as warm Atlantic water inflow, have been put forward to explain it. Here we present the first diatom-based high-resolution reconstruction of sea surface conditions in the central-eastern Baffin Bay between 14.0 and 10.2 kyr BP. The sea surface temperatures reveal warmer conditions beginning at ca. 13.4 kyr BP and leading to intensive calving and iceberg discharge from Jakobshavn Isbræ visible as increased sedimentation rates and deposition of coarse-grained material in our sediment stratigraphy. The warm YD ocean surface conditions in Baffin Bay are out of phase with the δ18O record from the North Greenland Ice Core Project (NGRIP) and other SST records from northern North-Atlantic. We show that the ocean has had significant interactions with the Greenland ice sheet in the past and emphasize its importance under the current warming of the North Atlantic.

Therapeutic Approach to Hypertension Urgencies and Emergencies in the Emergency Room.

PubMed

Maloberti, Alessandro; Cassano, Giulio; Capsoni, Nicolò; Gheda, Silvia; Magni, Gloria; Azin, Giulia Maria; Zacchino, Massimo; Rossi, Adriano; Campanella, Carlo; Beretta, Andrea Luigi Roberto; Bellone, Andrea; Giannattasio, Cristina

2018-05-18

Hypertensive urgencies-emergencies are important and common events. They are defined as a severe elevation in BP, higher than 180/120 mmHg, associated or not with the evidence of new or worsening organ damage for emergencies and urgencies respectively. Anamnestic information, physical examination and instrumental evaluation determine the following management that could need oral (for urgencies) or intravenous (for emergencies) anti-hypertensives drugs. The choice of the specific drugs depend on the underlying causes of the crisis, patient's demographics, cardiovascular risk and comorbidities. For emergencies a maximum BP reduction of 20-25% within the first hour and then to 160/110-100 over next 2-6 h, is considered appropriate with a further gradual decrease over the next 24-48 h to reach normal BP levels. In the case of hypertensive urgencies, a gradual lowering of BP over 24-48 h with an oral medication is the best approach and an aggressive BP lowering should be avoided. Subsequent management with particular attention on chronic BP values control is important as the right treatment of the acute phase.

Lightning and severe thunderstorms in event management.

PubMed

Walsh, Katie M

2012-01-01

There are a few national position stands/guidelines that address environmental conditions in athletics, yet they do not govern all outdoor sports. Extreme heat and cold, lightning, and severe wind can all be fatal, yet the majority of outdoor sports have no published guidelines addressing these conditions in relation to activity. Available research on extreme heat and cold conditions in athletics provides prevention strategies, to include acclimatization. Lightning and severe wind are two environmental conditions to which humans cannot accommodate, and they both can be deadly. There are strong positions on extreme heat/cold and lightning safety in athletics, but none affiliated with severe winds. Medical personnel involved in planning large outdoor sporting events must know of the presence of nationally published weather-related documents and apply them to their event. In addition, research needs to be expanded in the realm of establishing guidelines for safety to participants and spectators in severe wind conditions.

Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic

NASA Astrophysics Data System (ADS)

Mienis, F.; Duineveld, G. C. A.; Davies, A. J.; Lavaleye, M. M. S.; Ross, S. W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M. J. N.; de Haas, H.; Brooke, S.; van Weering, T. C. E.

2014-05-01

The Cape Lookout cold-water coral area off the coast of North Carolina forms the shallowest and northernmost cold-water coral mound area on the Blake Plateau in the NW Atlantic. Cold-water coral habitats near Cape Lookout are occasionally bathed in the Gulf Stream, which is characterised by oligotrophic warm water and strong surface currents. Here, we present the first insights into the mound distribution and morphology, sedimentary environment and coral cover and near-bed environmental conditions as recorded by bottom landers from this coral area. The mounds occur between 320 and 550 m water depth and are characterised by high acoustic backscatter indicating the presence of hard structure. Three distinct mound morphologies were observed: (1) a mound with a flattened top at 320 m, (2) multi-summited mounds with a teardrop shape in the middle part of the area and (3) a single mound at 540 m water depth. Echosounder profiles show the presence of a strong reflector underneath all mound structures that forms the base of the mounds. This reflector cropped out at the downstream side of the single mound and consists of carbonate slabs. Video analysis revealed that all mounds are covered by Lophelia pertusa and that living colonies only occur close to the summits of the SSW side of the mounds, which is the side that faces the strongest currents. Off-mound areas were characterised by low backscatter and sediment ripples, indicating the presence of relatively strong bottom currents. Two bottom landers were deployed amidst the coral mounds between December 2009 and May 2010. Both landers recorded prominent events, characterised by large fluctuations in environmental conditions near the seabed as well as in the overlying water column. The period between December and April was characterised by several events of increasing temperature and salinity, coinciding with increased flow and near-bed acoustic backscatter. During these events temperature fluctuated by up to 9 °C within a day, which is the largest temperature variability as measured so far in a cold-water coral habitat. Warm events, related to Gulf Stream meanders, had the duration of roughly 1 week and the current during these events was directed to the NNE. The consequences of such events must be significant given the strong effects of temperature on the metabolism of cold-water corals. Furthermore, elevated acoustic backscatter values and high mass fluxes were also recorded during these events, indicating a second stressor that may affect the corals. The abrasive nature of sand in combination with strong currents might sand blast the corals. We conclude that cold-water corals near Cape Lookout live under extreme conditions that limit mound growth at present.

Vaccines for the common cold.

PubMed

Simancas-Racines, Daniel; Guerra, Claudia V; Hidalgo, Ricardo

2013-06-12

The common cold is a spontaneously remitting infection of the upper respiratory tract, characterised by a runny nose, nasal congestion, sneezing, cough, malaise, sore throat and fever (usually < 37.8˚C). The widespread morbidity it causes worldwide is related to its ubiquitousness rather than its severity. The development of vaccines for the common cold has been difficult because of antigenic variability of the common cold virus and the indistinguishable multiple other viruses and even bacteria acting as infective agents. There is uncertainty regarding the efficacy and safety of interventions for preventing the common cold in healthy people. To assess the clinical effectiveness and safety of vaccines for preventing the common cold in healthy people. We searched CENTRAL (2012, Issue 12), MEDLINE (1948 to January week 1, 2013), EMBASE (1974 to January 2013), CINAHL (1981 to January 2013) and LILACS (1982 to January 2013). Randomised controlled trials (RCTs) of any virus vaccines to prevent the common cold in healthy people. Two review authors independently evaluated methodological quality and extracted trial data. Disagreements were resolved by discussion or by consulting a third review author. This review included one RCT with 2307 healthy participants; all of them were analysed. This trial compared the effect of an adenovirus vaccine against a placebo. No statistically significant difference in common cold incidence was found: there were 13 events in 1139 participants in the vaccines group and 14 events in 1168 participants in the placebo group; risk ratio (RR) 0.95, 95% confidence interval (CI) 0.45 to 2.02, P = 0.90). No adverse events related to the live vaccine were reported. This Cochrane review has found a lack of evidence on the effects of vaccines for the common cold in healthy people. Only one RCT was found and this did not show differences between comparison groups; it also had a high risk of bias. There are no conclusive data to support the use of vaccines for preventing the common cold in healthy people. We identified the need for well-designed, adequately powered RCTs to investigate vaccines for the common cold in healthy people. Unless RCTs provide evidence of a treatment effect and the trade-off between potential benefits and harms is established, policy-makers, clinicians and academics should not recommend the use of vaccines for preventing the common cold in healthy people. Any future trials on medical treatments for preventing the common cold should assess a variety of virus vaccines for this condition. Outcome measures should include common cold incidence, vaccine safety and mortality related to the vaccine.

Effects of cold front passage on turbulent fluxes over a large inland water

NASA Astrophysics Data System (ADS)

Zhang, Q.; Liu, H.

2011-12-01

Turbulent fluxes of sensible and latent heat over a large inland water in southern USA were measured using the eddy covariance method through the year of 2008. In addition, net radiation, air temperatures and relative humidity, and water temperature in different depths were also measured. The specific objective of this study is to examine effects of a cold front passage on the surface energy fluxes. For the typical cold front event selected from April 11 to 14, air temperature decreased by 16°C, while surface temperature only dropped 6°C. Atmospheric vapor pressure decreased by 1.6 kPa, while that in the water-air interface dropped 0.7 kPa. The behavior difference in the water-air interface was caused by the passage of cold, dry air masses immediately behind the cold front. During the cold front event, sensible heat and latent heat flux increased by 171 W m-2 and 284 W m-2, respectively. Linear aggression analysis showed that the sensible heat flux was proportional to the product of wind speed and the temperature gradient of water-air interface, with a correlation coefficient of 0.95. Latent heat flux was proportional to the product of wind speed and vapor pressure difference between the water surface and overlaying atmosphere, with a correlation coefficient of 0.81. Also, the correlations between both fluxes and the wind speed were weak. This result indicated that the strong wind associated with the cold front event contributed to the turbulent mixing, which indirectly enhanced surface energy exchange between the water surface and the atmosphere. The relationship between the water heat storage energy and turbulent fluxes was also examined.

The design, rationale, and baseline characteristics of a nationwide cohort registry in China: blood pressure and clinical outcome in TIA or ischemic stroke.

PubMed

Xu, Jie; Liu, Yi; Tao, Yongli; Xie, Xuewei; Gu, Hongqiu; Pan, Yuesong; Zhao, Xingquan; Wang, Yongjun; Yan, Aoshuang; Wang, Yilong

2016-01-01

The relationship between poststroke blood pressure (BP) and clinical outcomes in ischemic stroke (IS) is still controversial. However, there is no large BP database for IS or transient ischemic attack (TIA) in China. This study aims to describe the rationale, study design, and baseline characteristics of a nationwide BP database in IS or TIA patients in China. The BOSS (blood pressure and clinical outcome in TIA or ischemic stroke) study was a hospital-based, prospective cohort study aiming to assess BP parameters and clinical outcome in IS/TIA patients. BP parameters were based on office BP, ambulatory BP, and home BP. Clinical outcomes included stroke recurrence, combined vascular events, and disability. Electronic case-report forms were used to record baseline and follow-up data. The patients were followed up for clinical outcomes at 3 months through face-to-face interview and at 12 months by telephone. Between October 2012 and February 2014, the BOSS registry recruited 2,608 patients from 61 hospitals, with a mean age of 62.5 years, 32.4% of whom were female, 88.9% with an entry diagnosis of IS, and 86% diagnosed with hypertension. The rates of patients lost-to-follow-up were 3.1% at 3 months and 5.1% at 1 year; 93% of patients completed ambulatory BP monitoring during hospitalization and 94.7% finished a 3-month BP diary. The BOSS registry will provide important evidence about BP management in the acute phase and secondary prevention for IS/TIA patients.

The Late-Glacial and Holocene Marboré Lake sequence (2612 m a.s.l., Central Pyrenees, Spain): Testing high altitude sites sensitivity to millennial scale vegetation and climate variability

NASA Astrophysics Data System (ADS)

Leunda, Maria; González-Sampériz, Penélope; Gil-Romera, Graciela; Aranbarri, Josu; Moreno, Ana; Oliva-Urcia, Belén; Sevilla-Callejo, Miguel; Valero-Garcés, Blas

2017-10-01

This paper presents the environmental, climate and vegetation changes reconstructed for the last 14.6 kyr cal BP from the Marboré Lake sedimentary sequence, the highest altitude record (2612 m a.s.l.) in the Pyrenees studied up to date. We investigate the sensitivity of this high altitude site to vegetational and climate dynamics and altitudinal shifts during the Holocene by comparing palynological spectra of the fossil sequence and pollen rain content from current moss pollsters. We hypothesize that the input of sediments in lakes at such altitude is strongly controlled by ice phenology (ice-free summer months) and that during cold periods Pollen Accumulation Rate (PAR) and Pollen Concentration (PC) reflect changes in ice-cover and thus is linked to temperature changes. Low sedimentation rates and low PC and PAR occurred during colder periods as the Younger Dryas (GS-1) and the Holocene onset (12.6-10.2 kyr cal BP), suggesting that the lake-surface remained ice-covered for most of the year during these periods. Warmer conditions are not evident until 10.2 kyr cal BP, when an abrupt increase in sedimentation rate, PC and PAR occur, pointing to a delayed onset of the Holocene temperature increase at high altitude. Well-developed pinewoods and deciduous forest dominated the mid montane belt since 9.3 kyr cal BP until mid-Holocene (5.2 kyr cal BP). A downwards shift in the deciduous forest occurred after 5.2 kyr cal BP, in agreement with the aridity trend observed at a regional and Mediterranean context. The increase of herbaceous taxa during the late-Holocene (3.5 kyr cal BP-present) reflects a general trend to reduced montane forest, as anthropogenic disturbances were not evident until 1.3 kyr cal BP when Olea proportions from lowland areas and other anthropogenic indicators clearly expand. Our study demonstrates the need to perform local experimental approaches to check the effect of ice phenology on high altitude lakes sensitivity to vegetation changes to obtain more realistic reconstructions of mountain vegetation belts dynamics.

Does the association between broken partnership and first time myocardial infarction vary with time after break-up?

PubMed

Kriegbaum, Margit; Christensen, Ulla; Andersen, Per Kragh; Osler, Merete; Lund, Rikke

2013-12-01

Marriage is associated with lower risk of coronary heart disease, but it is unknown if the association depends on time since break-up with a partner. In this study we included both married and unmarried couples to study if the association between broken partnership (BP) and first time incident myocardial infarction (MI) changes with time since BP. Register study of the entire Danish population: the population was restricted to those aged 30 to 65 years with follow-up for incident MI between 1985 and 2006 with an annual record on each individual; in total 43 million records. The register data were used to identify MI events. Poisson regression was used to study associations between time since BP and MI adjusted for socio-demographic confounders and hospital admissions. Analyses were stratified by sex. Compared with unexposed (no BP), the incidence rate ratio (IRR) of MI in men with BP in the same year was 0.97 [95% confidence interval (CI) 0.90-1.05], year before BP was 1.25 (95% CI 1.17-1.34), 2-3 years after BP was 1.12 (95% CI 1.06-1.18), 4-8 years after BP was 1.09 (95% CI 1.05-1.14) and 9+ years since BP was 1.09 (95% CI 1.05-1.12). In women, the IRR same year as BP was 1.45 (95% CI 1.26-1.66), the year after BP was 1.30 (95% CI 1.14-1.50), 2-3 years after BP was 1.26 (95% CI 1.13-1.39), 4-8 years after BP was 1.17 (95% CI 1.08-1.26) and 9+ years since BP was 1.24 (95% CI 1.17-1.32). We found both a short-term elevated risk of first time MI following BP and a weaker long-term elevated risk, in both men and women.

Medically supervised water-only fasting in the treatment of borderline hypertension.

PubMed

Goldhamer, Alan C; Lisle, Douglas J; Sultana, Peter; Anderson, Scott V; Parpia, Banoo; Hughes, Barry; Campbell, T Colin

2002-10-01

Hypertension-related diseases are the leading causes of morbidity and mortality in industrially developed societies. Surprisingly, 68% of all mortality attributed to high blood pressure (BP) occurs with systolic BP between 120 and 140 mm Hg and diastolic BP below 90 mm Hg. Dietary and lifestyle modifications are effective in the treatment of borderline hypertension. One such lifestyle intervention is the use of medically supervised water-only fasting as a safe and effective means of normalizing BP and initiating health-promoting behavioral changes. Sixty-eight (68) consecutive patients with borderline hypertension with systolic BP in excess of 119 mm Hg and diastolic BP less than 91 mm Hg were treated in an inpatient setting under medical supervision. The treatment program consisted of a short prefasting period (approximately 1-2 days on average) during which food consumption was limited to fruits and vegetables followed by medically supervised water-only fasting (approximately 13.6 days on average). Fasting was followed by a refeeding period (approximately 6.0 days on average). The refeeding program consisted of a low-fat, low-sodium, plant-based, vegan diet. Approximately 82% of the subjects achieved BP at or below 120/80 mm Hg by the end of the treatment program. The mean BP reduction was 20/7 mm Hg, with the greatest decrease being observed for subjects with the highest baseline BP. A linear regression of BP decrease against baseline BP showed that the estimated BP below which no further decrease would be expected was 96.0/67.0 mm Hg at the end of the fast and 99.2/67.3 mm Hg at the end of refeeding. These levels are in agreement with other estimates of the BP below which stroke events are eliminated, thus suggesting that these levels could be regarded as the "ideal" BP values. Medically supervised water-only fasting appears to be a safe and effective means of normalizing BP and may assist in motivating health-promoting diet and lifestyle changes.

Intensive Versus Standard Blood Pressure Control in SPRINT-Eligible Participants of ACCORD-BP.

PubMed

Buckley, Leo F; Dixon, Dave L; Wohlford, George F; Wijesinghe, Dayanjan S; Baker, William L; Van Tassell, Benjamin W

2017-12-01

We sought to determine the effect of intensive blood pressure (BP) control on cardiovascular outcomes in participants with type 2 diabetes mellitus (T2DM) and additional risk factors for cardiovascular disease (CVD). This study was a post hoc, multivariate, subgroup analysis of ACCORD-BP (Action to Control Cardiovascular Risk in Diabetes Blood Pressure) participants. Participants were eligible for the analysis if they were in the standard glucose control arm of ACCORD-BP and also had the additional CVD risk factors required for SPRINT (Systolic Blood Pressure Intervention Trial) eligibility. We used a Cox proportional hazards regression model to compare the effect of intensive versus standard BP control on CVD outcomes. The "SPRINT-eligible" ACCORD-BP participants were pooled with SPRINT participants to determine whether the effects of intensive BP control interacted with T2DM. The mean baseline Framingham 10-year CVD risk scores were 14.5% and 14.8%, respectively, in the intensive and standard BP control groups. The mean achieved systolic BP values were 120 and 134 mmHg in the intensive and standard BP control groups ( P < 0.001). Intensive BP control reduced the composite of CVD death, nonfatal myocardial infarction (MI), nonfatal stroke, any revascularization, and heart failure (hazard ratio 0.79; 95% CI 0.65-0.96; P = 0.02). Intensive BP control also reduced CVD death, nonfatal MI, and nonfatal stroke (hazard ratio 0.69; 95% CI 0.51-0.93; P = 0.01). Treatment-related adverse events occurred more frequently in participants receiving intensive BP control (4.1% vs. 2.1%; P = 0.003). The effect of intensive BP control on CVD outcomes did not differ between patients with and without T2DM ( P > 0.62). Intensive BP control reduced CVD outcomes in a cohort of participants with T2DM and additional CVD risk factors. © 2017 by the American Diabetes Association.

Hydroclimate variability in the Nile River Basin during the past 28,000 years

NASA Astrophysics Data System (ADS)

Castañeda, Isla S.; Schouten, Stefan; Pätzold, Jürgen; Lucassen, Friedrich; Kasemann, Simone; Kuhlmann, Holger; Schefuß, Enno

2016-03-01

It has long been known that extreme changes in North African hydroclimate occurred during the late Pleistocene yet many discrepancies exist between sites regarding the timing, duration and abruptness of events such as Heinrich Stadial (HS) 1 and the African Humid Period (AHP). The hydroclimate history of the Nile River is of particular interest due to its lengthy human occupation history yet there are presently few continuous archives from the Nile River corridor, and pre-Holocene studies are rare. Here we present new organic and inorganic geochemical records of Nile Basin hydroclimate from an eastern Mediterranean (EM) Sea sediment core spanning the past 28 ka BP. Our multi-proxy records reflect the fluctuating inputs of Blue Nile versus White Nile material to the EM Sea in response to gradual changes in local insolation and also capture abrupt hydroclimate events driven by remote climate forcings, such as HS1. We find strong evidence for extreme aridity within the Nile Basin evolving in two distinct phases during HS1, from 17.5 to 16 ka BP and from 16 to 14.5 ka BP, whereas peak wet conditions during the AHP are observed from 9 to 7 ka BP. We find that zonal movements of the Congo Air Boundary (CAB), and associated shifts in the dominant moisture source (Atlantic versus Indian Ocean moisture) to the Nile Basin, likely contributed to abrupt hydroclimate variability in northern East Africa during HS1 and the AHP as well as to non-linear behavior of hydroclimate proxies. We note that different proxies show variable gradual and abrupt responses to individual hydroclimate events, and thus might have different inherent sensitivities, which may be a factor contributing to the controversy surrounding the abruptness of past events such as the AHP. During the Late Pleistocene the Nile Basin experienced extreme hydroclimate fluctuations, which presumably impacted Paleolithic cultures residing along the Nile corridor.

Holocene Mass Transport Deposits in Western Norwegian fjords and lakes revealing prehistoric earthquake history of Scandinavia

NASA Astrophysics Data System (ADS)

Bellwald, B.; Hjelstuen, B. O.; Sejrup, H. P.; Kuvås, J.; Stokowy, T.

2016-12-01

The sensitivity of fjord sediments to seismic shaking makes fjord systems appropriate study sites when extending regional earthquake catalogs back in time and when estimating recurrence rates of prehistoric earthquakes in intraplate settings. In this study we compiled evidence of 140 postglacial mass movement events and their associated mass transport deposits (MTDs) from previously analyzed and new sediment cores and high-resolution seismic profiles from 22 fjord systems and six lakes in Western Norway. Evaluation of trigger mechanisms make us infer that most of these mass movement events were initiated by regional earthquakes, and that both climate-related processes and tsunamis most likely can be excluded as trigger mechanism for most of the events. A total of 33 individual earthquakes has been identified, which most likely outbalance the historically recorded events in magnitude, thus indicating magnitudes >6. Frequency plots of MTDs suggest high seismic activity in the early Holocene (11000-9700 cal. yrs BP), followed by seismic quiescence in the mid-Holocene before a seismic reactivation took place at 4000 cal. yrs BP. Coevally-triggered MTDs at 8100 cal. yrs BP are identified in all the archives, and are correlating with the age of the offshore Storegga slide. We estimate earthquake recurrence rates of 1/80 years directly after the last deglaciation of Western Norway (12800-11600 ca. yrs BP), 1/200 years for the early Holocene and 1/300 years for the last 4000 years. Our compilation suggests that the mid-Holocene is characterized by low seismic activity, suggesting recurrence rates of 1/1300 years. Comparisons of the Western Norwegian dataset with paleoseimologic studies of other previously glaciated intraplate settings indicate that both Scandinavia and the Alps show similar trends as Western Norway, whereas Eastern Canada is not correlating with the paleoseismologic trend of this study, which could be explained by different deglaciation histories.

Two cold-season derechoes in Europe

NASA Astrophysics Data System (ADS)

Gatzen, Christoph; Púčik, Tomas; Ryva, David

2011-06-01

In this study, we apply for the first time the definition of a derecho (Johns and Hirt, 1987) to European cold-season convective storm systems. These occurred on 18 January 2007 and 1 March 2008, respectively, and they are shown to fulfill the criteria of a derecho. Damaging winds were reported over a distance of 1500 km and locally reached F3 intensity. Synoptic analysis for the events reveal strongly forced situations that have been described for cold-season derechoes in the United States. A comparison of swaths of damaging winds, radar structures, detected lightning, cold pool development, and cloud-top temperatures indicates that both derechoes formed along cold fronts that were affected by strong quasi-geostrophic forcing. It seems that the overlap of the cold front position with the strong differential cyclonic vorticity advection at the cyclonic flank of mid-level jet streaks favoured intense convection and high winds. The movement and path width of the two derechoes seemed to be related to this overlap. The wind gust intensity that was also different for both events is discussed and could be related to the component of the mid-level winds perpendicular to the gust fronts.

Obstructive sleep apnea syndrome and hypertension: mechanism of the linkage and 24-h blood pressure control.

PubMed

Kario, Kazuomi

2009-07-01

Hypertensive patients with obstructive sleep apnea syndrome (OSAS) constitute a high-risk group for metabolic syndrome. OSAS directly induces negative intrathoracic pressure and decreases pulmonary stretch receptor stimulation, chemoreceptor stimulation, hypoxemia, hypercapnia and microarousal. These changes potentiate various risk factors, including the sympathetic nervous system, renin-angiotensin-aldosterone system and inflammation. Early detection and treatment of OSAS in asymptomatic hypertensive patients is essentially important to prevent hypertensive target organ damage and subsequent cardiovascular events. Continuous positive airway pressure (CPAP) therapy, a first-line treatment in hypertensive patients with moderate to severe OSAS, reduces ambulatory BP level, particularly during the sleep period, and midnight BP surge. However, individual differences in the BP-lowering effect of CPAP have been observed. OSAS hypertensive patients who do not tolerate CPAP remain at a high risk for cardiovascular disease because of negative intrathoracic pressure and need more aggressive antihypertensive treatment to achieve 24-h BP control with nocturnal BP <120/70 mm Hg.

The relationship between carotid blood pressure reactivity to mental stress and carotid intima-media thickness.

PubMed

Spartano, Nicole L; Augustine, Jacqueline A; Lefferts, Wesley K; Gump, Brooks B; Heffernan, Kevin S

2014-10-01

Brachial blood pressure (BP) reactivity to stress predicts large artery damage and future cardiovascular (CV) events. Central BP is an emerging risk factor associated with target organ damage (TOD). Currently, little is known about the central BP response to mental stress and its association to TOD. Twenty-five healthy, non-obese adults completed a computerized mental stress test. Brachial and carotid systolic (S)BP reactivity to stress were calculated as SBP during stress minus resting SBP. Resting carotid intima-media thickness (IMT) was also measured. Carotid SBP reactivity to stress was significantly associated with carotid IMT, independent of age, sex, body mass index, non-high density lipoprotein cholesterol and brachial SBP reactivity to stress (r = 0.386, p < 0.05). The relationship between carotid SBP reactivity and carotid IMT suggests that the central BP response to stress may prove to be an early risk marker for potential subclinical TOD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Extreme climatic conditions and health service utilisation across rural and metropolitan New South Wales

NASA Astrophysics Data System (ADS)

Jegasothy, Edward; McGuire, Rhydwyn; Nairn, John; Fawcett, Robert; Scalley, Benjamin

2017-08-01

Periods of successive extreme heat and cold temperature have major effects on human health and increase rates of health service utilisation. The severity of these events varies between geographic locations and populations. This study aimed to estimate the effects of heat waves and cold waves on health service utilisation across urban, regional and remote areas in New South Wales (NSW), Australia, during the 10-year study period 2005-2015. We divided the state into three regions and used 24 over-dispersed or zero-inflated Poisson time-series regression models to estimate the effect of heat waves and cold waves, of three levels of severity, on the rates of ambulance call-outs, emergency department (ED) presentations and mortality. We defined heat waves and cold waves using excess heat factor (EHF) and excess cold factor (ECF) metrics, respectively. Heat waves generally resulted in increased rates of ambulance call-outs, ED presentations and mortality across the three regions and the entire state. For all of NSW, very intense heat waves resulted in an increase of 10.8% (95% confidence interval (CI) 4.5, 17.4%) in mortality, 3.4% (95% CI 0.8, 7.8%) in ED presentations and 10.9% (95% CI 7.7, 14.2%) in ambulance call-outs. Cold waves were shown to have significant effects on ED presentations (9.3% increase for intense events, 95% CI 8.0-10.6%) and mortality (8.8% increase for intense events, 95% CI 2.1-15.9%) in outer regional and remote areas. There was little evidence for an effect from cold waves on health service utilisation in major cities and inner regional areas. Heat waves have a large impact on health service utilisation in NSW in both urban and rural settings. Cold waves also have significant effects in outer regional and remote areas. EHF is a good predictor of health service utilisation for heat waves, although service needs may differ between urban and rural areas.

Avoided climate impacts of urban and rural heat and cold waves over the U.S. using large climate model ensembles for RCP8.5 and RCP4.5

PubMed Central

Anderson, G.B.; Jones, B.; McGinnis, S.A.; Sanderson, B.

2015-01-01

Previous studies examining future changes in heat/cold waves using climate model ensembles have been limited to grid cell-average quantities. Here, we make use of an urban parameterization in the Community Earth System Model (CESM) that represents the urban heat island effect, which can exacerbate extreme heat but may ameliorate extreme cold in urban relative to rural areas. Heat/cold wave characteristics are derived for U.S. regions from a bias-corrected CESM 30-member ensemble for climate outcomes driven by the RCP8.5 forcing scenario and a 15-member ensemble driven by RCP4.5. Significant differences are found between urban and grid cell-average heat/cold wave characteristics. Most notably, urban heat waves for 1981–2005 are more intense than grid cell-average by 2.1°C (southeast) to 4.6°C (southwest), while cold waves are less intense. We assess the avoided climate impacts of urban heat/cold waves in 2061–2080 when following the lower forcing scenario. Urban heat wave days per year increase from 6 in 1981–2005 to up to 92 (southeast) in RCP8.5. Following RCP4.5 reduces heat wave days by about 50%. Large avoided impacts are demonstrated for individual communities; e.g., the longest heat wave for Houston in RCP4.5 is 38 days while in RCP8.5 there is one heat wave per year that is longer than a month with some lasting the entire summer. Heat waves also start later in the season in RCP4.5 (earliest are in early May) than RCP8.5 (mid-April), compared to 1981–2005 (late May). In some communities, cold wave events decrease from 2 per year for 1981–2005 to one-in-five year events in RCP4.5 and one-in-ten year events in RCP8.5. PMID:29520121

Possible mechanisms for four regimes associated with cold events over East Asia

NASA Astrophysics Data System (ADS)

Yang, Zifan; Huang, Wenyu; Wang, Bin; Chen, Ruyan; Wright, Jonathon S.; Ma, Wenqian

2017-09-01

Circulation patterns associated with cold events over East Asia during the winter months of 1948-2014 are classified into four regimes by applying a k-means clustering method based on the area-weighted pattern correlation. The earliest precursor signals for two regimes are anticyclonic anomalies, which evolve into Ural and central Siberian blocking-like circulation patterns. The earliest precursor signals for the other two regimes are cyclonic anomalies, both of which evolve to amplify the East Asian trough (EAT). Both the blocking-like circulation patterns and amplified EAT favor the initialization of cold events. On average, the blocking-related regimes tend to last longer. The lead time of the earliest precursor signal for the central Siberian blocking-related regime is only 4 days, while those for the other regimes range from 16 to 18 days. The North Atlantic Oscillation plays essential roles both in triggering the precursor for the Ural blocking-related regime and in amplifying the precursors for all regimes. All regimes preferentially occur during the positive phase of the Eurasian teleconnection pattern and the negative phase of the El Niño-Southern Oscillation. For three regimes, surface cooling is primarily due to reduced downward infrared radiation and enhanced cold advection. For the remaining regime, which is associated with the southernmost cooling center, sensible and latent heat release and horizontal cold advection dominate the East Asian cooling.

Multidisciplinary distinction of mass-movement and flood-induced deposits in lacustrine environments: implications for Holocene palaeohydrology and natural hazards (Lake Ledro, Southern Alps, Italy)

NASA Astrophysics Data System (ADS)

Simonneau, A.; Chapron, E.; Vannière, B.; Wirth, S. B.; Gilli, A.; Di Giovanni, C.; Anselmetti, F. S.; Desmet, M.; Magny, M.

2012-08-01

High-resolution seismic profiles and sediment cores from Lake Ledro combined with soil and river-bed samples from the lake's catchment area are used to assess the recurrence of natural hazards (earthquakes and flood events) in the southern Italian Alps during the Holocene. Two well-developed deltas and a flat central basin are identified on seismic profiles in Lake Ledro. Lake sediments are finely laminated in the basin since 9000 cal. yr BP and frequently interrupted by two types of sedimentary events: light-coloured massive layers and dark-coloured graded beds. Optical analysis (quantitative organic petrography) of the organic matter occurring in soils, river beds and lacustrine samples together with lake-sediment bulk density and grain-size analysis illustrate that light-coloured layers consist of a mixture of lacustrine sediments and mainly contain algal particles similar to the ones observed in background sediments. Light-coloured layers thicker than 1.5 cm in the main basin of Lake Ledro are dense and synchronous to numerous coeval mass-wasting deposits remoulding the slopes of the basin. They are interpreted as subaquatic mass movements triggered by historical and pre-historical regional earthquakes dated to 2005 AD, 1891 AD, 1045 AD and 1260, 2545, 2595, 3350, 3815, 4740, 7190, 9185 and 11495 cal. yr BP. Dark-coloured sedimentary event are dense and develop high-amplitude reflections in front of the deltas and in the deep central basin. These beds are mainly made of terrestrial organic matter (soils and ligno-cellulosic debris) and are interpreted as resulting from intense hyperpycnal flood events. Mapping and quantifying the amount of soil material accumulated in the Holocene hyperpycnal flood deposits of the sequence and applying the De Ploey erosion model allow estimating that the equivalent soil thickness eroded over the catchment area reached up to 4 mm during the largest Holocene flood events. Such significant soil erosion is interpreted as resulting from the combination of heavy rainfall and snowmelt. The recurrence of flash-flood events during the Holocene was however not high enough to affect pedogenesis processes and highlight several wet regional periods during the Holocene. The Holocene period is divided into four phases of environmental evolution. Over the first half of the Holocene, a progressive stabilization of the soils present through the catchment of Lake Ledro was associated with a progressive reforestation of the area and only interrupted during the wetter 8.2 event when the soil destabilization was particularly important. Lower soil erosion was recorded during the Mid-Holocene climatic optimum (8000-4200 cal. yr BP) and associated with higher algal production. Between 4200 and 3100 cal. yr BP, both wetter climate and human activities within the drainage basin drastically increased soil erosion rates. Finally, from 3100 cal. yr BP to the present-day, results suggest increasing and changing human land-use.

Persistent cold air outbreaks over North America in a warming climate

DOE PAGES

Gao, Yang; Leung, L. Ruby; Lu, Jian; ...

2015-03-30

This study examines future changes of cold air outbreaks (CAO) using a multi-model ensemble of global climate simulations from the Coupled Model Intercomparison Project Phase 5 as well as regional high resolution climate simulations. In the future, while robust decrease of CAO duration dominates in most regions, the magnitude of decrease over northwestern U.S. is much smaller than the surrounding regions. We identified statistically significant increases in sea level pressure during CAO events centering over Yukon, Alaska, and Gulf of Alaska that advects continental cold air to northwestern U.S., leading to blocking and CAO events. Changes in large scale circulationmore » contribute to about 50% of the enhanced sea level pressure anomaly conducive to CAO in northwestern U.S. in the future. High resolution regional simulations revealed potential contributions of increased existing snowpack to increased CAO in the near future over the Rocky Mountain, southwestern U.S., and Great Lakes areas through surface albedo effects, despite winter mean snow water equivalent decreases in the future. Overall, the multi-model projections emphasize that cold extremes do not completely disappear in a warming climate. Concomitant with the relatively smaller reduction in CAO events in northwestern U.S., the top 5 most extreme CAO events may still occur in the future, and wind chill warning will continue to have societal impacts in that region.« less

Decadal-scale Climate Variability on the Central Iranian Plateau Spanning the So-called 4.2 ka BP Drought Event

NASA Astrophysics Data System (ADS)

Carolin, S.; Walker, R. T.; Henderson, G. M.; Maxfield, L.; Ersek, V.; Sloan, A.; Talebian, M.; Fattahi, M.; Nezamdoust, J.

2015-12-01

The influence of climate on the growth and development of ancient civilizations throughout the Holocene remains a topic of heated debate. The 4.2 ka BP global-scale mid-to-low latitude aridification event (Walker et al., 2012) in particular has incited various correlation proposals. Some authors suggest that this event may have led to the collapse of the Akkadian empire in Mesopotamia, one of the first empires in human history, as well as to changes among other Early Bronze Age societies dependent on cereal agriculture (eg. Staubwasser and Weiss, 2006). Other authors remain doubtful of the impact of environmental factors on the collapse of past societies (eg. Middleton, 2012). While coincident timing of an environmental event with archeological evidence does not necessitate a causation, a comprehensive understanding of climate variability in the ancient Near East is nonetheless an essential component to resolving the full history of early human settlements. Paleoclimate data on the Central Iranian Plateau, a region rich with ancient history, is exceptionally sparse compared to other areas. Many karst locations are found throughout the region, however, setting the stage for the development of several high-resolution, accurate and precisely-dated climate proxy records if a correlation between the chemistry of semi-arid speleothem samples and climate is resolved. Here we present a 5.1-3.7 ka BP record of decadal-scale stalagmite stable isotope and trace metal variability. The stalagmite was collected in Gol-e zard cave (35.8oN, 52.0oE), ~100 km NE of Tehran on the southern flank of the Alborz mountain range (2530masl). The area currently receives ~270mm mean annual precipitation, with more than 90% of precipitation falling within the wet season (November-May). We use GNIP data from Tehran and local and regional meteorological data to resolve the large-scale mechanisms forcing isotopic variations in rainwater over Gol-e zard cave. We discuss possible transformation of water isotopes during transition through the karst aquifer based on site properties and simple model experiments. Finally, we discuss the timing and magnitude of significant events in the stable isotope and trace metal records, particularly in relation to the 4.2 ka BP drought event apparent in certain other regional climate records.

Hillslope gullying in the Solway Firth — Morecambe Bay region, Great Britain: Responses to human impact and/or climatic deterioration?

NASA Astrophysics Data System (ADS)

Chiverrell, R. C.; Harvey, A. M.; Foster, G. C.

2007-02-01

In the Solway Firth — Morecambe Bay region of Great Britain there is evidence for heightened hillslope instability during the late Holocene (after 3000 cal. BP). Little or no hillslope geomorphic activity has been identified occurring during the early Holocene, but there is abundant evidence for late Holocene hillslope erosion (gullying) and associated alluvial fan and valley floor deposition. Interpretation of the regional radiocarbon chronology available from organic matter buried beneath alluvial fan units suggests much of this geomorphic activity can be attributed to four phases of more extensive gullying identified after 2500-2200, 1300-1000, 1000-800 and 500 cal. BP. Both climate and human impact models can be evoked to explain the crossing of geomorphic thresholds: and palaeoecological data on climatic change (bog surface wetness) and human impact (pollen), together with archaeological and documentary evidence of landscape history, provide a context for addressing the causes of late Holocene geomorphic instability. High magnitude storm events are the primary agent responsible for gully incision, but neither such events nor cooler/wetter climatic episodes appear to have produced gully systems in the region before 3000 cal. BP. Increased gullying after 2500-2200 cal. BP coincides with population expansion during Iron Age and Romano-British times. The widespread and extensive gullying after 1300-1000 cal. BP and after 1000-800 cal. BP coincides with periods of population expansion and a growing rural economy identified during Norse times, 9-10th centuries AD, and during the Medieval Period, 12-13th centuries AD. These periods were separated by a downturn associated with the 'harrying of the north' AD 1069 to 1070. The gullying episode after 500 cal. BP also coincides with increased anthropogenic pressure on the uplands, with population growth and agricultural expansion after AD 1500 following 150 years of malaise caused by livestock and human (the Black Death) plagues, poor harvests and conflicts on the Scottish/English border. The increased susceptibility to erosion of gullies is a response to increased anthropogenic pressure on upland hillslopes during the late Holocene, and the role of this pressure appears crucial in priming hillslopes before subsequent major storm events. In particular, the cycles of expansion and contraction in both population and agriculture appear to have affected the susceptibility of the upland landscape to erosion, and the hillslope gullying record in the region, therefore, contributes to understanding of the timing and spatial pattern of human exploitation of the upland landscape.

Lateral Cortical Thickening and Bone Heterogeneity of the Subtrochanteric Femur Measured With Quantitative CT as Indicators for Early Detection of Atypical Femoral Fractures in Long-Term Bisphosphonate Users.

PubMed

Lee, Seung Hyun; Lee, Young Han; Suh, Jin-Suck

2017-10-01

The objective of our study was to compare subtrochanteric femur bone mineral density (BMD) and bone quality of long-term bisphosphonate (BP) users who sustained an atypical femoral fracture (AFF) with BP users who did not sustain a femoral fracture and BP-naïve patients with no history of femoral fracture using quantitative CT (QCT). Fourteen female BP users with an AFF (mean age, 72.6 years; mean duration of BP use, 6.2 years; mean body mass index, 21.9) who had undergone QCT before fracture events were sex-, age-, BP use duration-, and body mass index-matched to 14 BP users who did not sustain a fracture and 14 BP-naïve patients. The lateral cortical thickness index (CTI) and the mean BMD (BMD mean ) and SD of the BMD (BMD SD ) within the lateral cortex and within the entire cross-sectional area of the subtrochanteric femur were measured on axial QCT. Femoral neck-shaft angles were measured on the QCT scout image. Parameters were analyzed using the Kruskal-Wallis test. Lateral CTIs were greater in the BP users with an AFF (median, 0.28) than in the BP users without a femoral fracture (median, 0.21) (p = 0.038) and the BP-naïve group (median, 0.21) (p = 0.009). The lateral cortex BMD SD was significantly higher in the BP users with an AFF (median, 59.59 mg/cm 3 ) than the BP users without a femoral fracture (median, 39.27 mg/cm 3 ; p = 0.049) and the BP-naïve group (median, 31.02 mg/cm 3 ; p = 0.037). There was no significant difference among groups in lateral cortex BMD mean , BMD mean and BMD SD of the entire cross-sectional area, and femoral neck-shaft angle. Long-term BP users with a subsequent AFF had a thicker lateral cortex and higher lateral cortex BMD SD at the subtrochanteric area before the fracture on QCT than BP users who did not sustain a femoral fracture and BP-naïve patients.

A novel, extremely alkaliphilic and cold-active esterase from Antarctic desert soil.

PubMed

Hu, Xiao Ping; Heath, Caroline; Taylor, Mark Paul; Tuffin, Marla; Cowan, Don

2012-01-01

A novel, cold-active and highly alkaliphilic esterase was isolated from an Antarctic desert soil metagenomic library by functional screening. The 1,044 bp gene sequence contained several conserved regions common to lipases/esterases, but lacked clear classification based on sequence analysis alone. Moderate (<40%) amino acid sequence similarity to known esterases was apparent (the closest neighbour being a hypothetical protein from Chitinophaga pinensis), despite phylogenetic distance to many of the lipolytic "families". The enzyme functionally demonstrated activity towards shorter chain p-nitrophenyl esters with the optimal activity recorded towards p-nitrophenyl propionate (C3). The enzyme possessed an apparent T(opt) at 20°C and a pH optimum at pH 11. Esterases possessing such extreme alkaliphily are rare and so this enzyme represents an intriguing novel locus in protein sequence space. A metagenomic approach has been shown, in this case, to yield an enzyme with quite different sequential/structural properties to known lipases. It serves as an excellent candidate for analysis of the molecular mechanisms responsible for both cold and alkaline activity and novel structure-function relationships of esterase activity.

Multifaceted re-analysis of the enigmatic Kitimat slide complex, Canada

NASA Astrophysics Data System (ADS)

Stacey, Cooper D.; Lintern, D. Gwyn; Enkin, Randolph J.

2018-07-01

Repeat submarine landslides are challenging to study due to the tendency of subsequent slides to destroy previous deposits. Repeat slides are common in fjord head deltas where high amounts of sediment are focused in narrow valleys. This study examines a well-known slide deposit associated with the Kitimat Delta on Canada's west coast that has been linked to tsunamigenic landslides in 1974 and 1975. For the first time we incorporate multibeam bathymetry to a multifaceted dataset including new high resolution acoustic data and sediment cores to examine the history of submarine slides at the Kitimat Delta. Based on morphological analysis and age modelling using 210Pb and 14C data, we determine that the complex surface morphology of the slide lobe consists of at least two large slide deposits that reach 5 km from the delta: the known event that occurred in 1975 and an older event that occurred at 623 ± 83 cal BP (95% confidence interval). We demonstrate that slide deposits can be differentiated based on surface morphology and acoustic character. This is confirmed by age modelling. The 1975 slide resulted in a flow that ploughed through the seabed creating compression and translation along a basal shear plane, resulting in deep deformation and a surface characterized by pressure ridges. The 623 ± 83 cal BP event resulted in a large amount of blocky slide material that overran the former seafloor and was transported >5 km from the delta front. Several buried events are observed at depth, one of which occurred at 2592 ± 84 cal BP and appears to be on the same order of magnitude as the 1975 event and showing very similar acoustic characteristics. As for hazard implications, we show submarine landslides of varying sizes have naturally occurred on this delta throughout the past several thousand years.

Frequent eruptions of Mount Rainier over the last ˜2,600 years

NASA Astrophysics Data System (ADS)

Sisson, T. W.; Vallance, J. W.

2009-08-01

Field, geochronologic, and geochemical evidence from proximal fine-grained tephras, and from limited exposures of Holocene lava flows and a small pyroclastic flow document ten-12 eruptions of Mount Rainier over the last 2,600 years, contrasting with previously published evidence for only 11-12 eruptions of the volcano for all of the Holocene. Except for the pumiceous subplinian C event of 2,200 cal year BP, the late-Holocene eruptions were weakly explosive, involving lava effusions and at least two block-and-ash pyroclastic flows. Eruptions were clustered from ˜2,600 to ˜2,200 cal year BP, an interval referred to as the Summerland eruptive period that includes the youngest lava effusion from the volcano. Thin, fine-grained tephras are the only known primary volcanic products from eruptions near 1,500 and 1,000 cal year BP, but these and earlier eruptions were penecontemporaneous with far-traveled lahars, probably created from newly erupted materials melting snow and glacial ice. The most recent magmatic eruption of Mount Rainier, documented geochemically, was the 1,000 cal year BP event. Products from a proposed eruption of Mount Rainier between AD 1820 and 1854 (X tephra of Mullineaux (US Geol Surv Bull 1326:1-83, 1974)) are redeposited C tephra, probably transported onto young moraines by snow avalanches, and do not record a nineteenth century eruption. We found no conclusive evidence for an eruption associated with the clay-rich Electron Mudflow of ˜500 cal year BP, and though rare, non-eruptive collapse of unstable edifice flanks remains as a potential hazard from Mount Rainier.

Tight versus standard blood pressure control in patients with hypertension with and without cardiovascular disease.

PubMed

Reboldi, Gianpaolo; Angeli, Fabio; de Simone, Giovanni; Staessen, Jan A; Verdecchia, Paolo

2014-03-01

An excessive blood pressure (BP) reduction might be dangerous in high-risk patients with cardiovascular disease. In the Studio Italiano Sugli Effetti CARDIOvascolari del Controllo della Pressione Arteriosa SIStolica (Cardio-Sis), 1111 nondiabetic patients with systolic BP ≥150 mm Hg were randomly assigned to a systolic BP target <140 mm Hg (standard control) or <130 mm Hg (tight control). We stratified patients by absence (n=895) or presence (n=216) of established cardiovascular disease at entry. Antihypertensive treatment was open-label and tailored to each patient's needs. After 2-year follow-up, the primary end point of the study, electrocardiographic left ventricular hypertrophy, occurred less frequently in the tight than in the standard control group in the patients without (10.8% versus 15.2%) and with (14.1% versus 23.5%) established cardiovascular disease (P for interaction=0.82). The main secondary end point, a composite of cardiovascular events and all-cause death, occurred less frequently in the tight than in the standard control group both in patients without (1.47 versus 3.68 patient-years; P=0.016) and with (7.87 versus 11.22 patient-years; P=0.049) previous cardiovascular disease. In a multivariable Cox model, allocation to tight BP control reduced the risk of cardiovascular events to a similar extent in patients with or without overt cardiovascular disease at randomization (P for interaction=0.43). In conclusion, an intensive treatment aimed to lower systolic BP<130 mm Hg reduced left ventricular hypertrophy and improved clinical outcomes to a similar extent in patients with hypertension and without established cardiovascular disease.

Early intervention of long-acting nifedipine GITS reduces brachial–ankle pulse wave velocity and improves arterial stiffness in Chinese patients with mild hypertension: a 24-week, single-arm, open-label, prospective study

PubMed Central

Zhang, Jidong; Wang, Yan; Hu, Haijuan; Yang, Xiaohong; Tian, Zejun; Liu, Demin; Gu, Guoqiang; Zheng, Hongmei; Xie, Ruiqin; Cui, Wei

2016-01-01

Background Nifedipine gastrointestinal therapeutic system (GITS) is used to treat angina and hypertension. The authors aimed to study the early intervention impact on arterial stiffness and pulse wave velocity (PWV) independent of its blood-pressure-(BP) lowering effect in mild hypertensive patients. Methods This single-center, single-arm, open-label, prospective, Phase IV study recruited patients with mild hypertension and increased PWV from December 2013 to December 2014 (N=138; age, 18–75 years; systolic blood pressure, 140–160 mmHg; diastolic BP, 90–100 mmHg; increased brachial–ankle pulse wave velocity [baPWV, ≥12 m/s]). Nifedipine GITS (30 mg/d) was administered for 24 weeks to achieve target BP of <140/90 mmHg. The dose was uptitrated at 60 mg/d in case of unsatisfactory BP reduction after 4 weeks. Primary study end point was the change in baPWV after nifedipine GITS treatment. Hemodynamic parameters (office BP, 24-hour ambulatory BP monitoring, and heart rate and adverse events) were evaluated at baseline and followed-up at 2, 4, 8, 12, 18, and 24 weeks. Results Majority of patients (n=117; 84.8%) completed the study. baPWV decreased significantly at 4 weeks compared with baseline (1,598.87±239.82 vs 1,500.89±241.15 cm/s, P<0.001), was stable at 12 weeks (1,482.24±215.14 cm/s, P<0.001), and remained steady through 24 weeks (1,472.58±205.01 cm/s, P<0.001). Office BP reduced from baseline to week 4 (154/95 vs 136/85 mmHg) and remained steady until 24 weeks. Nifedipine GITS significantly decreased 24-hour ambulatory BP monitoring (P<0.001) after 24 weeks from baseline. Mean arterial pressure and pulse pressure were lowered significantly after 4, 12, and 24 weeks of treatment (P<0.001). These changes in baPWV were significantly correlated with changes in systolic blood pressure, diastolic BP, and mean arterial pressure (P<0.05), but not with changes in pulse pressure (P>0.05). There were no other drug-related serious adverse events. Conclusion Nifedipine GITS was considerably effective in reducing baPWV and BP, indicating improvement in arterial stiffness as early as 4 weeks. PMID:27799740

Variable prognostic value of blood pressure response to exercise.

PubMed

Kato, Yuko; Suzuki, Shinya; Uejima, Tokuhisa; Semba, Hiroaki; Yamashita, Takeshi

2018-01-01

The aim of this study was to evaluate the impact of patient background including exercise capacity on the relationship between the blood pressure (BP) response to exercise and prognosis in patients visiting a cardiovascular hospital. A total of 2134 patients who were referred to our hospital underwent symptom-limited maximal cardiopulmonary exercise testing, and were followed through medical records and mail. The BP response to exercise was defined as the difference between peak and rest systolic BP. The end point was set as cardiovascular events including cardiovascular death, acute coronary syndrome, hospitalization for heart failure, and cerebral infarction. During a median follow-up period of 3 years, 179 (8%) patients reached the end point (2.5%/year). Multivariate analysis showed that BP response was independently and negatively associated with the occurrence of the end point. This prognostic significance of BP response was consistent regardless of left ventricular ejection fraction, renal function, presence of heart failure symptoms, the presence of organic heart disease, and hypertension. However, peak VO 2 showed a significant interaction with the effects of BP response on the end point, suggesting that the prognostic value of BP response was limited in patients with preserved exercise capacity. The role of BP response to exercise as the predictor depends on exercise capacity of each patient. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Mid-Holocene Climate and Culture Change in the Atacama Desert, Northern Chile

NASA Astrophysics Data System (ADS)

Grosjean, Martin; Núñez, Lautaro; Cartajena, Isabel; Messerli, Bruno

1997-09-01

Twenty archaeological campsites intercalated between more than 30 debris flows caused by heavy rainfall events between 6200 and 3100 14C yr B.P. have recently been discovered at Quebrada Puripica in the Atacama Desert of northern Chile. This record provides detailed information about extreme, short-lived climatic events during the hyperarid mid-Holocene period. For the first time, we found evidence of continuous human occupation in this area, filling the regional hiatus in the Atacama basin ("Silencio Arqueologico") between 8000 and 4800 14C yr B.P. The transformation of Early Archaic hunters into the complex Late Archaic cultural tradition was an adaptive process. During this time, the site was a local ecological refuge with abundant resources in a generally hostile environment.

The Glacial and Relative Sea Level History of Southern Banks Island, NT, Canada

NASA Astrophysics Data System (ADS)

Vaughan, Jessica Megan

The mapping and dating of surficial glacial landforms and sediments across southern Banks Island document glaciation by the northwest Laurentide Ice Sheet (LIS) during the last glacial maximum. Geomorphic landforms confirm the operation of an ice stream at least 1000 m thick in Amundsen Gulf that was coalescent with thin, cold-based ice crossing the island's interior, both advancing offshore onto the polar continental shelf. Raised marine shorelines across western and southern Banks Island are barren, recording early withdrawal of the Amundsen Gulf Ice Stream prior to the resubmergence of Bering Strait and the re-entry of Pacific molluscs ~13,750 cal yr BP. This withdrawal resulted in a loss of ~60,000 km2 of ice --triggering drawdown from the primary northwest LIS divide and instigating changes in subsequent ice flow. The Jesse moraine belt on eastern Banks Island records a lateglacial stillstand and/or readvance of Laurentide ice in Prince of Wales Strait (13,750 -- 12,750 cal yr BP). Fossiliferous raised marine sediments that onlap the Jesse moraine belt constrain final deglaciation to ~12,600 cal yr BP, a minimum age for the breakup of the Amundsen Gulf Ice Stream. The investigation of a 30 m thick and 6 km wide stratigraphic sequence at Worth Point, southwest Banks Island, identifies an advance of the ancestral LIS during the Mid-Pleistocene (sensu lato), substantially diversifying the glacial record on Banks Island. Glacial ice emplaced during this advance has persisted through at least two glacial-interglacial cycles, demonstrating the resilience of circumpolar permafrost. Pervasive deformation of the stratigraphic sequence also records a detailed history of glaciotectonism in proglacial and subglacial settings that can result from interactions between cold-based ice and permafrost terrain. This newly recognized history rejects the long-established paleoenvironmental model of Worth Point that assumed a simple 'layer-cake' stratigraphy.

Transcriptome and gene expression analysis of DHA producer Aurantiochytrium under low temperature conditions

PubMed Central

Ma, Zengxin; Tan, Yanzhen; Cui, Guzhen; Feng, Yingang; Cui, Qiu; Song, Xiaojin

2015-01-01

Aurantiochytrium is a promising docosahexaenoic acid (DHA) production candidate due to its fast growth rate and high proportions of lipid and DHA content. In this study, high-throughput RNA sequencing technology was employed to explore the acclimatization of this DHA producer under cold stress at the transcriptional level. The overall de novo assembly of the cDNA sequence data generated 29,783 unigenes, with an average length of 1,200 bp. In total, 13,245 unigenes were annotated in at least one database. A comparative genomic analysis between normal conditions and cold stress revealed that 2,013 genes were differentially expressed during the growth stage, while 2,071 genes were differentially expressed during the lipid accumulation stage. Further functional categorization and analyses showed some differentially expressed genes were involved in processes crucial to cold acclimation, such as signal transduction, cellular component biogenesis, and carbohydrate and lipid metabolism. A brief survey of the transcripts obtained in response to cold stress underlines the survival strategy of Aurantiochytrium; of these transcripts, many directly or indirectly influence the lipid composition. This is the first study to perform a transcriptomic analysis of the Aurantiochytrium under low temperature conditions. Our results will help to enhance DHA production by Aurantiochytrium in the future. PMID:26403200

Transcriptome and gene expression analysis of DHA producer Aurantiochytrium under low temperature conditions.

PubMed

Ma, Zengxin; Tan, Yanzhen; Cui, Guzhen; Feng, Yingang; Cui, Qiu; Song, Xiaojin

2015-09-25

Aurantiochytrium is a promising docosahexaenoic acid (DHA) production candidate due to its fast growth rate and high proportions of lipid and DHA content. In this study, high-throughput RNA sequencing technology was employed to explore the acclimatization of this DHA producer under cold stress at the transcriptional level. The overall de novo assembly of the cDNA sequence data generated 29,783 unigenes, with an average length of 1,200 bp. In total, 13,245 unigenes were annotated in at least one database. A comparative genomic analysis between normal conditions and cold stress revealed that 2,013 genes were differentially expressed during the growth stage, while 2,071 genes were differentially expressed during the lipid accumulation stage. Further functional categorization and analyses showed some differentially expressed genes were involved in processes crucial to cold acclimation, such as signal transduction, cellular component biogenesis, and carbohydrate and lipid metabolism. A brief survey of the transcripts obtained in response to cold stress underlines the survival strategy of Aurantiochytrium; of these transcripts, many directly or indirectly influence the lipid composition. This is the first study to perform a transcriptomic analysis of the Aurantiochytrium under low temperature conditions. Our results will help to enhance DHA production by Aurantiochytrium in the future.

Comparative Effectiveness of Blood Pressure-lowering Drugs in Patients who have Already Suffered From Stroke

PubMed Central

Wang, Wei-Ting; You, Li-Kai; Chiang, Chern-En; Sung, Shih-Hsien; Chuang, Shao-Yuan; Cheng, Hao-Min; Chen, Chen-Huan

2016-01-01

Abstract Hypertension is the most important risk factor for stroke and stroke recurrence. However, the preferred blood pressure (BP)-lowering drug class for patients who have suffered from a stroke has yet to be determined. To investigate the relative effects of BP-lowering therapies [angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blockers (ARB), β blockers, calcium channel blockers (CCBs), diuretics, and combinations of these drugs] in patients with a prior stroke history, we performed a systematic review and meta-analysis using both traditional frequentist and Bayesian random-effects models and meta-regression of randomized controlled trials (RCTs) on the outcomes of recurrent stroke, coronary heart disease (CHD), and any major adverse cardiac and cerebrovascular events (MACCE). Trials were identified from searches of published hypertension guidelines, electronic databases, and previous systematic reviews. Fifteen RCTs composed of 39,329 participants with previous stroke were identified. Compared with the placebo, only ACEI along with diuretics significantly reduced recurrent stroke events [odds ratio (OR) = 0.54, 95% credibility interval (95% CI) 0.33–0.90]. On the basis of the distribution of posterior probabilities, the treatment ranking consistently identified ACEI along with diuretics as the preferred BP-lowering strategy for the reduction of recurrent stroke and CHD (31% and 35%, respectively). For preventing MACCE, diuretics appeared to be the preferred agent for stroke survivors (34%). Moreover, the meta-regression analysis failed to demonstrate a statistical significance between BP reduction and all outcomes (P = 0.1618 for total stroke, 0.4933 for CHD, and 0.2411 for MACCE). Evidence from RCTs supports the use of diuretics-based treatment, especially when combined with ACEI, for the secondary prevention of recurrent stroke and any vascular events in patients who have suffered from stroke. PMID:27082571

Nocturnal Blood Pressure in Young Adults and Cognitive Function in Midlife: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

PubMed Central

Ning, Hongyan; Muntner, Paul; Reis, Jared P.; Calhoun, David A.; Viera, Anthony J.; Levine, Deborah A.; Jacobs, David R.; Shimbo, Daichi; Liu, Kiang; Greenland, Philip; Lloyd-Jones, Donald

2015-01-01

BACKGROUND Nocturnal blood pressure (BP) is associated with risk for cardiovascular events. However, the relationship between nocturnal BP in young adults and cognitive function in midlife remains unclear. METHODS We used data from the ambulatory BP monitoring substudy of the Coronary Artery Risk Development in Young Adults Study, including 224 participants (mean age 30 years, 45% men, 63% African Americans). At the 20-year follow-up, the Stroop test (executive function), Digit Symbol Substitution Test (psychomotor speed), and Rey Auditory Verbal Learning Test (verbal memory) were assessed. RESULTS Baseline mean office, daytime, and nocturnal BP were 109/73, 120/74, and 107/59mm Hg, respectively. Nocturnal BP dipping, calculated as (nocturnal systolic BP [SBP] − daytime SBP) × 100/daytime SBP, was divided into quartiles (Q1: −39.3% to −16.9%; Q2: −16.8% to −13.2%, Q3 [reference]: −13.1% to −7.8%, and Q4: −7.7% to +56.4%). In multiple regression analyses, the least nocturnal SBP dipping (Q4 vs. reference) and higher nocturnal diastolic BP level were associated with worse Stroop scores, with adjustments for demographic and clinical characteristics, and cumulative exposure to office BP during follow-up (β [standard error]: 0.37 [0.18] and 0.19 [0.07], respectively; all P < 0.05). Digit Symbol Substitution Test and Rey Auditory Verbal Learning Test were not significantly associated with nocturnal SBP dipping or nocturnal SBP/diastolic BP levels. CONCLUSIONS Among healthy young adults, less nocturnal SBP dipping and higher nocturnal diastolic BP levels were associated with lower executive function in midlife, independent of multiple measures of office BP during long-term follow-up. PMID:25783740

Model-based decision making in early clinical development: minimizing the impact of a blood pressure adverse event.

PubMed

Stroh, Mark; Addy, Carol; Wu, Yunhui; Stoch, S Aubrey; Pourkavoos, Nazaneen; Groff, Michelle; Xu, Yang; Wagner, John; Gottesdiener, Keith; Shadle, Craig; Wang, Hong; Manser, Kimberly; Winchell, Gregory A; Stone, Julie A

2009-03-01

We describe how modeling and simulation guided program decisions following a randomized placebo-controlled single-rising oral dose first-in-man trial of compound A where an undesired transient blood pressure (BP) elevation occurred in fasted healthy young adult males. We proposed a lumped-parameter pharmacokinetic-pharmacodynamic (PK/PD) model that captured important aspects of the BP homeostasis mechanism. Four conceptual units characterized the feedback PD model: a sinusoidal BP set point, an effect compartment, a linear effect model, and a system response. To explore approaches for minimizing the BP increase, we coupled the PD model to a modified PK model to guide oral controlled-release (CR) development. The proposed PK/PD model captured the central tendency of the observed data. The simulated BP response obtained with theoretical release rate profiles suggested some amelioration of the peak BP response with CR. This triggered subsequent CR formulation development; we used actual dissolution data from these candidate CR formulations in the PK/PD model to confirm a potential benefit in the peak BP response. Though this paradigm has yet to be tested in the clinic, our model-based approach provided a common rational framework to more fully utilize the limited available information for advancing the program.

Efficacy and safety of sacubitril/valsartan in patients with essential hypertension uncontrolled by olmesartan: A randomized, double-blind, 8-week study.

PubMed

Cheung, Deanna G; Aizenberg, Diego; Gorbunov, Vladimir; Hafeez, Kudsia; Chen, Chien-Wei; Zhang, Jack

2018-01-01

A majority of patients with hypertension fail to achieve blood pressure (BP) control despite treatment with commonly prescribed drugs. This randomized, double-blind phase III trial assessed the superiority of sacubitril/valsartan 200 mg (97/103 mg) to continued olmesartan 20 mg in reducing ambulatory systolic BP after 8-week treatment in patients with mild to moderate essential hypertension uncontrolled with olmesartan 20 mg alone. A total of 376 patients were randomized to receive either sacubitril/valsartan (n = 188) or olmesartan (n = 188). Superior reductions in 24-hour mean ambulatory systolic BP were observed in the sacubitril/valsartan group vs the olmesartan group (-4.3 mm Hg vs -1.1 mm Hg, P < .001). Reductions in 24-hour mean ambulatory diastolic BP and pulse pressure and office systolic BP and diastolic BP were significantly greater with sacubitril/valsartan vs olmesartan (P < .014). A greater proportion of patients achieved BP control with sacubitril/valsartan vs olmesartan. The overall incidence of adverse events was comparable between the groups. Compared with continued olmesartan, sacubitril/valsartan was more effective and generally safe in patients with hypertension uncontrolled with olmesartan 20 mg. ©2018 Wiley Periodicals, Inc.

Intraseasonal variability in the summer South China Sea: Wind jet, cold filament, and recirculations

NASA Astrophysics Data System (ADS)

Xie, Shang-Ping; Chang, Chueh-Hsin; Xie, Qiang; Wang, Dongxiao

2007-10-01

A recent study shows that the blockage of the southwest monsoon by the mountain range on the east coast of Indochina triggers a chain of ocean-atmospheric response, including a wind jet and cold filament in the South China Sea (SCS). We extend this climatological analysis by using higher temporal resolution (weekly) to study intraseasonal variability in summer. Our analysis shows that the development of the wind jet and cold filament is not a smooth seasonal process but consists of several intraseasonal events each year at about 45-day intervals. In a typical intraseasonal event, the wind jet intensifies to above 12 m/s, followed in a week by the development of a cold filament advected by an offshore jet east of South Vietnam on the boundary of a double gyre circulation in the ocean. The double gyre circulation itself also strengthens in response to the intraseasonal wind event via Rossby wave adjustment, reaching the maximum strength in 2 to 3 weeks. The intraseasonal cold filaments appear to influence the surface wind, reducing the local wind speed because of the increased static stability in the near-surface atmosphere. To first order, the above sequence of events may be viewed as the SCS response to atmospheric intraseasonal wind pulses, which are part of the planetary-scale boreal summer intraseasonal oscillation characterized by the northeastward propagation of atmospheric deep convection. The intraseasonal anomalies of sea surface temperature and precipitation are in phase over the SCS, suggesting an oceanic feedback onto the atmosphere. As wind variations are now being routinely monitored by satellite, the lags of 1-3 weeks in oceanic response offer useful predictability that may be exploited.

When an Increase in Central Systolic Pressure Overrides the Benefits of Heart Rate Lowering.

PubMed

Messerli, Franz H; Rimoldi, Stefano F; Bangalore, Sripal; Bavishi, Chirag; Laurent, Stephane

2016-08-16

An elevated resting heart rate has been unequivocally linked to adverse cardiovascular events. Conversely, a physiologically low heart rate may confer longevity benefits. Moreover, pharmacological heart rate lowering reduces cardiovascular outcomes in patients with heart failure, with the magnitude of the reduction associated with survival benefit. In contrast, pharmacological heart rate lowering paradoxically increases cardiovascular events in hypertension, possibly because it elicits a ventricular-vascular mismatch, leading to increased central systolic blood pressure (BP). By the same hemodynamic mechanism, pharmacological heart rate lowering also engenders an increase in central (aortic) BP in coronary heart disease and, as a consequence, fails to decrease myocardial oxygen consumption. Whether in heart failure, hypertension, or coronary heart disease, or even athletes, heart rate lowering consistently increases central systolic pressure. The increase in central systolic BP is prone to abolish the potential benefits of heart rate lowering interventions, possibly accounting for failure to reduce outcomes in patients with hypertension and coronary artery disease. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Morning blood pressure surge: pathophysiology, clinical relevance and therapeutic aspects

PubMed Central

Bilo, Grzegorz; Grillo, Andrea; Guida, Valentina; Parati, Gianfranco

2018-01-01

Morning hours are the period of the day characterized by the highest incidence of major cardiovascular events including myocardial infarction, sudden death or stroke. They are also characterized by important neurohormonal changes, in particular, the activation of sympathetic nervous system which usually leads to a rapid increase in blood pressure (BP), known as morning blood pressure surge (MBPS). It was hypothesized that excessive MBPS may be causally involved in the pathogenesis of cardiovascular events occurring in the morning by inducing hemodynamic stress. A number of studies support an independent relationship of MBPS with organ damage, cerebrovascular complications and mortality, although some heterogeneity exists in the available evidence. This may be due to ethnic differences, methodological issues and the confounding relationship of MBPS with other features of 24-hour BP profile, such as nocturnal dipping or BP variability. Several studies are also available dealing with treatment effects on MBPS and indicating the importance of long-acting antihypertensive drugs in this regard. This paper provides an overview of pathophysiologic, methodological, prognostic and therapeutic aspects related to MBPS. PMID:29872338

A Comprehensive Safety Evaluation of 68Ga-Labeled Ligand Prostate-Specific Membrane Antigen 11 PET/CT in Prostate Cancer: The Results of 2 Prospective, Multicenter Trials.

PubMed

Nielsen, Julie B; Zacho, Helle D; Haberkorn, Uwe; Nielsen, Karin M; Dettmann, Katja; Langkilde, Niels C; Petersen, Lars J

2017-07-01

The aim of this study was to evaluate the clinical safety profile of the Ga-PSMA-11 ligand for PET/CT imaging in prospective clinical trials. Eighty-eight patients with newly diagnosed or recurrent prostate cancer participated in 2 prospective trials. Safety reporting was identical in the 2 trials. The Ga-PSMA-11 ligand was administered as 2 MBq/kg body weight (mean, 9.2 μg, 9.7 nmol). The reporting of clinical adverse events (AEs) and the measurement of blood pressure (BP) and heart rate (HR) were performed prior to injection (baseline); immediately after injection of Ga-PSMA-11 (postinjection); at 1, 10, and 60 minutes after injection; and after acquisition of the PET/CT scan (postscan). All hemodynamic assessments were performed in the supine position, except for the postscan measurement (sitting). The patients were interviewed regarding any AEs at baseline, postinjection, or postscan. In addition, the patients were instructed to report any AEs during the investigation and to contact the investigator if AEs occurred during the rest of the day. Adverse events were classified as mild, moderate, or severe by the patients and categorized by the investigator using the CTCAE (Common Terminology Criteria for Adverse Events) version 4.0. There were no reported clinical AEs. There were significant decreases in systolic BP (P < 0.001) and HR (P < 0.001) over time. In comparison, the diastolic BP increased significantly (P < 0.001). After removal of the last observation (supine position), there was no time-dependent change in systolic or diastolic BP, but the significant change in HR remained. The mean changes over the entire observation period were minimal (systolic BP, -6 to 5 mm Hg; diastolic BP, -2 to 3 mm Hg; HR, decrease of 5 beats/min). No patients developed hypotension. Fifty-five patients presented with hypertension at baseline, which increased by 1 CTCAE grade in 15 patients and by 2 grades in 2 patients. A large number of cases of asymptomatic (grade 1) bradycardia were observed, primarily in patients with preexisting bradycardia. One patient developed transient grade 1 tachycardia. No patients required medical intervention for cardiovascular perturbations. Ga-PSMA-11 PET/CT was very well tolerated. We consider Ga-PSMA-11 to be safe for human application.

Antihypertensive efficacy of the losartan/hydrochlorothiazide combination and its effect on plasma B-type natriuretic peptide in hypertensive patients uncontrolled by angiotensin II type 1 receptor antagonist-based therapy: a multicentre prospective observational study.

PubMed

Meno, Hiroshi; Inou, Tetsuji; Tanaka, Michiko; Tsuchiya, Yoshihiro; Shiga, Yuhei; Kobayashi, Kenji; Nakamura, Yuichiro; Ota, Takeaki; Kubara, Ichiro

2012-03-01

Although strict blood pressure (BP) control is effective in the prevention of cardiovascular events, it is often insufficient in many hypertensive patients. B-type natriuretic peptide (BNP) has been shown to be associated with cardiovascular events. We investigated the effects of the losartan/hydrochlorothiazide combination on BP and plasma BNP in hypertensive patients uncontrolled by an angiotensin II type 1 receptor antagonist (angiotensin receptor blocker [ARB])-based therapy. In a multicentre prospective observational study, we enrolled 185 patients aged 36-79 years (mean age 63.8 years) with essential hypertension but without symptoms of heart failure who received an ARB-based therapy for ≥3 months but failed to achieve a target BP recommended by the Japanese Society of Hypertension (JSH). ARBs were switched to losartan (LOS) 50 mg/hydrochlorothiazide (HCTZ) 12.5 mg. The antihypertensive efficacy, safety, and effects of this combination on blood biochemical parameters and plasma BNP were evaluated for 12 months. Mean ± SD systolic and diastolic BP decreased from 152 ± 13/87 ± 10 mmHg to 128 ± 14/74 ± 10 mmHg, respectively, after 12 months (p < 0.001). Mean ± SD plasma BNP levels decreased significantly from 46.0 ± 83.0 pg/mL to 40.8 ± 68.0 pg/mL (p < 0.05). The percentage of patients who achieved the JSH 2004 target BP was 51% after 12 months; the percentage was 63% in elderly patients aged ≥65 years without complications, and 43% in patients with concomitant diabetes mellitus or chronic kidney disease. No association was found between a decrease in plasma BNP levels and BP, age, body mass index or estimated glomerular filtration rate. There was a significant increase in serum uric acid and a decrease in serum potassium, but both were within the range of normal values. Adverse events were observed in 8.6% of the patients. Antihypertensive treatment using two types of drugs (LOS/HCTZ) with different mechanisms yielded potent antihypertensive efficacy with safety and decreased plasma BNP levels.

First Younger Dryas moraines in Greenland

NASA Astrophysics Data System (ADS)

Funder, Svend; Larsen, Nicolaj K.; Linge, Henriette; Möller, Per; Schomacker, Anders; Fabel, Derek; Kjær, Kurt H.; Xu, Sheng

2016-04-01

Over the Greenland ice sheet the Younger Dryas (YD) cold climate oscillation (12.9-11.7 kaBP) began with up to 10°C drop in temperatures and ended with up to 12°C abrupt warming. In the light of the present warming and melting of the ice sheet, and its importance for future climate change, the ice sheet's response to these dramatic changes in the past is of great interest. However, even though much effort has gone into charting YD ice margin behaviour around Greenland in recent years, no clear-cut signal of response to the oscillation has been uncovered. Here we show evidence to suggest that three major outlets from a local ice cap at Greenland's north coast advanced and retreated synchronously during YD. The evidence comprises OSL (optically stimulated luminescence) dates from a marine transgression of the coastal valleys that preceded the advance, and exposure ages from boulders on the moraines, formed by glaciers that overrode the marine sediment. The OSL ages suggest a maximum age of 12.4 ±0.6 kaBP for the marine incursion, and 10 exposure ages on boulders from the three moraines provide an average minimum age of 12.5 ±0.7 kaBP for the moraines, implying that the moraines were formed within the interval 11.8-13.0 kaBP. Elsewhere in Greenland evidence for readvance has been recorded in two areas. Most notably, in the East Greenland fjord zone outlet glaciers over a stretch of 800 km coast advanced through the fjords. In Scoresby Sund, where the moraines form a wide belt, an extensive 14C and exposure dating programme has shown that the readvance here probably culminated before YD, while cessation of moraine formation and rapid retreat from the moraine belt did not commence until c. 11.5 kaBP, but no moraines have so far been dated to YD. Readvance is also seen in Disko Bugt, the largest ice sheet outlet in West Greenland. However, here the advance and retreat of the ice stream took place in mid YD times, and lasted only a few hundred years, while YD in general was characterised by large scale, more than 200 km, retreat on the shelf. Therefore, although readvance and retreat occurred in both areas, the readvance was apparently not triggered by the initial YD cooling nor was the retreat caused by the abrupt warming at the end. At all other sites with a record that run through or into YD - Southeast Greenland, South Greenland, northern West Greenland - the ice margins were apparently retreating through YD, leaving the north coast as the only area with evidence for a climatically conditioned YD readvance/retreat. The apparent mismatch between ice core temperatures and ice margin behaviour is generally seen as a function of reduced AMOC (Atlantic Meridional Overturning Circulation), inducing both higher seasonality with very cold winters and warm summers, and also occurrence of warm subsurface water to melt the ice sheet margin along some coasts. Therefore the ice margin response to the cold oscillation was to some extent determined by the nearness to the North Atlantic - with North Greenland being the farthest away. Although this may explain why glaciers advanced in North Greenland, while they melted in more southerly parts, it still leaves the question with a bearing on the future: why don't we see any ice margin response neither to the initial YD cooling, nor to the abrupt warming at the end?

Inland aeolian deposits of the Iberian Peninsula: Sand dunes and clay dunes of the Duero Basin and the Manchega Plain. Palaeoclimatic considerations

NASA Astrophysics Data System (ADS)

Bernat Rebollal, M.; Pérez-González, A.

2008-12-01

This paper describes the latest research on the geomorphological characteristics, formation environment and chronology of the main inland aeolian deposits from the south-eastern Duero Basin (DB) and the Manchega Plain (MP) of the Iberian Peninsula. Similarities and differences between the aeolian deposits of these two locations are summarised. Wind deflation from the Guadiana and Júcar alluvial systems created the aeolian deposits of the MP. These deposits are mainly composed of quartz sands. However, in the San Juan alluvial plain (MP) there is a large extent of clay dunes formed by exposure to prevalent winds of seasonal playa-lakes with salt and clay sediments. In the DB, wind remobilisation of the small particles from Quaternary terraces and Tertiary arkosic sediments left aeolian deposits of quartz-feldspar sands. Textural parameters of the aeolian deposits show large variations depending on the location and the original deposit. Thus, in the DB the aeolian sands derived from the deflation of fluvial sediments are better sorted and smaller in grain size than those created by the deflation of arkosic sediments. Morphologically, simple and compound parabolic dunes (U-V forms, hemicyclic, lobate and elongate), crescentic and linear dunes, climbing dunes and blowout dunes have been recognized at both sites. Barchan and dome dunes are present only in the DB while "lunette lunette-clay dunes" are found only in the MP. In both locations, the large extent of aeolian sand sheets and the predominance of simple and compound parabolic dunes indicates the active role of sparse vegetation cover in the formation of this aeolian system. In the DB, dunes were formed by southwest and west winds, while in the MP the aeolian morphologies indicate that the prevalent winds were west and northwest. The chronology of the dune deposits is being determined with luminescence (TL-OSL) dating and Mass Spectrometry Analysis ( 14C-AMS). In this way, the aeolian activity and stabilisation stages can be established, the latter well marked in the DB through soil A horizon development. Thus, the main sand dune formation in the DB and the eastern regions of the MP occurred between 13.5 and 7 ka BP, during the cold and arid Younger Dryas episode and the Early Holocene. The clay dunes of the MP accumulated mainly from 29 to 19 ka BP that corresponds with Heinrich events HE-3 and HE-2 and the Last Glacial Maximum. However, clay dunes were also formed between 13.5 and 7 ka BP. In both locations, there have been reactivations of some sand deposits in the recent Holocene, with maximum activity around 5-2 ka BP and 0.5-0.2 ka BP. On the other hand, three marked stages of stabilisation of the DB aeolian system have been established with 14C-AMS, around 10.2, 6.2 and 1.2 ka BP. Finally, the main winds contributing to dune construction were also responsible for the deflation processes with the formation of erosional depressions.

The ABCs of Front Management

USDA-ARS?s Scientific Manuscript database

Frost protection or protecting plants from cold temperatures where they could be damaged must be a major consideration in orchard planning. Cold temperature protection events commonly occur during "radiation" frost conditions when the sky is clear, there is little wind and temperature inversions ca...

The 2017 Focused Update of the Guidelines of the Taiwan Society of Cardiology (TSOC) and the Taiwan Hypertension Society (THS) for the Management of Hypertension.

PubMed

Chiang, Chern-En; Wang, Tzung-Dau; Lin, Tsung-Hsien; Yeh, Hung-I; Liu, Ping-Yen; Cheng, Hao-Min; Chao, Ting-Hsing; Chen, Chen-Huan; Shyu, Kou-Gi; Ueng, Kwo-Chang; Chen, Chung-Yin; Chu, Pao-Hsien; Sung, Shih-Hsien; Wang, Kang-Ling; Li, Yi-Heng; Wang, Kuo-Yang; Chiang, Fu-Tien; Lai, Wen-Ter; Chen, Jyh-Hong; Chen, Wen-Jone; Yeh, San-Jou; Chen, Ming-Fong; Lin, Shing-Jong; Lin, Jiunn-Lee

2017-05-01

Hypertension (HT) is the most important risk factor for cardiovascular diseases. Over the past 25 years, the number of individuals with hypertension and the estimated associated deaths has increased substantially. There have been great debates in the past few years on the blood pressure (BP) targets. The 2013 European Society of Hypertension and European Society of Cardiology HT guidelines suggested a unified systolic BP target of 140 mmHg for both high-risk and low-risk patients. The 2014 Joint National Committee report further raised the systolic BP targets to 150 mmHg for those aged ≥ 60 years, including patients with stroke or coronary heart disease, and raised the systolic BP target to 140 mmHg for diabetes. Instead, the 2015 Hypertension Guidelines of the Taiwan Society of Cardiology and the Taiwan Hypertension Society suggested more aggressive BP targets of < 130/80 mmHg for patients with diabetes, coronary heart disease, chronic kidney disease with proteinuria, and atrial fibrillation patients on antithrombotic therapy. Based on the main findings from the Systolic Blood Pressure Intervention Trial (SPRINT) and several recent meta-analyses, the HT committee members of the Taiwan Society of Cardiology and the Taiwan Hypertension Society convened and finalized the revised BP targets for management of HT. We suggested a new systolic BP target to < 120 mmHg for patients with coronary heart disease, chronic kidney disease with an eGFR of 20-60 ml/min/1.73 m 2 , and elderly patients aged ≥ 75 years, using unattended automated office BP measurement. When traditional office BP measurement is applied, we suggested BP target of < 140/90 mmHg for elderly patients with an age ≥ 75 years. Other BP targets with traditional office BP measurement remain unchanged. With these more aggressive BP targets, it is foreseeable that the cardiovascular events will decrease substantially in Taiwan.

177Lu-3BP-227 for Neurotensin Receptor 1-Targeted Therapy of Metastatic Pancreatic Adenocarcinoma: First Clinical Results.

PubMed

Baum, Richard P; Singh, Aviral; Schuchardt, Christiane; Kulkarni, Harshad R; Klette, Ingo; Wiessalla, Stefan; Osterkamp, Frank; Reineke, Ulrich; Smerling, Christiane

2018-05-01

Neurotensin receptor 1 (NTR1) is overexpressed in ductal pancreatic adenocarcinoma, which is still one of the deadliest cancers, with a very poor prognosis. Eligible patients were offered salvage radiopharmaceutical therapy with the novel NTR1 antagonist 177 Lu-3BP-227. Methods: Six patients with confirmed ductal pancreatic adenocarcinoma who had exhausted all other treatment options received 177 Lu-3BP-227 for evaluation of NTR1 expression in vivo. Three patients received treatment activities of 5.1-7.5 GBq. Results: Administration of 177 Lu-3BP-227 was well tolerated by all patients. The kidneys were identified as the dose-limiting organ. The most severe adverse event was reversible grade 2 anemia. One patient achieved a partial response and experienced significant improvement of symptoms and quality of life. This patient survived 13 mo from diagnosis and 11 mo from the start of 177 Lu-3BP-227 therapy. Conclusion: This initial report provides clinical evidence of the feasibility of treatment of ductal pancreatic adenocarcinoma using 177 Lu-3BP-227. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Asynchronous marine-terrestrial signals of the last deglacial warming in East Asia associated with low- and high-latitude climate changes.

PubMed

Xu, Deke; Lu, Houyuan; Wu, Naiqin; Liu, Zhenxia; Li, Tiegang; Shen, Caiming; Wang, Luo

2013-06-11

A high-resolution multiproxy record, including pollen, foraminifera, and alkenone paleothermometry, obtained from a single core (DG9603) from the Okinawa Trough, East China Sea (ECS), provided unambiguous evidence for asynchronous climate change between the land and ocean over the past 40 ka. On land, the deglacial stage was characterized by rapid warming, as reflected by paleovegetation, and it began ca. 15 kaBP, consistent with the timing of the last deglacial warming in Greenland. However, sea surface temperature estimates from foraminifera and alkenone paleothermometry increased around 20-19 kaBP, as in the Western Pacific Warm Pool (WPWP). Sea surface temperatures in the Okinawa Trough were influenced mainly by heat transport from the tropical western Pacific Ocean by the Kuroshio Current, but the epicontinental vegetation of the ECS was influenced by atmospheric circulation linked to the northern high-latitude climate. Asynchronous terrestrial and marine signals of the last deglacial warming in East Asia were thus clearly related to ocean currents and atmospheric circulation. We argue that (i) early warming seawater of the WPWP, driven by low-latitude insolation and trade winds, moved northward via the Kuroshio Current and triggered marine warming along the ECS around 20-19 kaBP similar to that in the WPWP, and (ii) an almost complete shutdown of the Atlantic Meridional Overturning Circulation ca. 18-15 kaBP was associated with cold Heinrich stadial-1 and delayed terrestrial warming during the last deglacial warming until ca. 15 kaBP at northern high latitudes, and hence in East Asia. Terrestrial deglacial warming therefore lagged behind marine changes by ca. 3-4 ka.

A six-stalagmite composite record of East Asian Summer Monsoon in northern China since 11.5 thousand years ago

NASA Astrophysics Data System (ADS)

Shen, C. C.; Dong, J.; Kong, X.; WU, C. C.; Ren, H. A.; Wang, Y.

2017-12-01

Here we present replicated carbonate δ18O records of six stalagmites with sub-decadal to multi-decadal resolutions from Lianhua Cave (38º10'N, 113º43'E), Shanxi Province, to reveal a detailed evolution of the East Asian Summer Monsoon (EASM) intensity in northern China since 11.5 thousand years ago (ka BP, before 1950 AD). This composite record shows that solar forcing dominated hydroclimatic changes, including an intensified monsoon at the Holocene Optimum from the termination of Younger Dryas to 6.5 ka BP, and a subsequent multi-millennial weakening of monsoon intensity, that agree with cave records in central and southern China. However, the EASM has retreated southwards more rapidly than the Indian summer monsoon after 6.5 ka BP, resulting in aridity conditions occurring at 4.0 ka BP in northern China, which is almost 2000-year earlier than in central and southern China. This asynchroneity may be related to the different regional responses among the coupling of the EASM, Indian summer monsoon, the solar forcing, and the differences in thermal forcing due to complex geographical configurations. In addition, a relative enrichment of 1‰ in 18O data of Lianhua record from 9.5 to 8.1 ka BP shows that the Holocene Optimum was punctuated by a millennial-long weak monsoon interval, which is not registered among previous cave records in central and southern China. The fresh water-induced cold climate conditions in the North Atlantic region could create stronger East Asian winter monsoon and induce a weakened EASM and a southward shift of rain belt in northern China. Therefore, it shall not be surprised that there are strong heterogeneities among regional hydroclimatic conditions across monsoonal China in the Holocene.

Asynchronous marine-terrestrial signals of the last deglacial warming in East Asia associated with low- and high-latitude climate changes

PubMed Central

Xu, Deke; Lu, Houyuan; Wu, Naiqin; Liu, Zhenxia; Li, Tiegang; Shen, Caiming; Wang, Luo

2013-01-01

A high-resolution multiproxy record, including pollen, foraminifera, and alkenone paleothermometry, obtained from a single core (DG9603) from the Okinawa Trough, East China Sea (ECS), provided unambiguous evidence for asynchronous climate change between the land and ocean over the past 40 ka. On land, the deglacial stage was characterized by rapid warming, as reflected by paleovegetation, and it began ca. 15 kaBP, consistent with the timing of the last deglacial warming in Greenland. However, sea surface temperature estimates from foraminifera and alkenone paleothermometry increased around 20–19 kaBP, as in the Western Pacific Warm Pool (WPWP). Sea surface temperatures in the Okinawa Trough were influenced mainly by heat transport from the tropical western Pacific Ocean by the Kuroshio Current, but the epicontinental vegetation of the ECS was influenced by atmospheric circulation linked to the northern high-latitude climate. Asynchronous terrestrial and marine signals of the last deglacial warming in East Asia were thus clearly related to ocean currents and atmospheric circulation. We argue that (i) early warming seawater of the WPWP, driven by low-latitude insolation and trade winds, moved northward via the Kuroshio Current and triggered marine warming along the ECS around 20–19 kaBP similar to that in the WPWP, and (ii) an almost complete shutdown of the Atlantic Meridional Overturning Circulation ca. 18–15 kaBP was associated with cold Heinrich stadial-1 and delayed terrestrial warming during the last deglacial warming until ca. 15 kaBP at northern high latitudes, and hence in East Asia. Terrestrial deglacial warming therefore lagged behind marine changes by ca. 3–4 ka. PMID:23720306

Seismic Triggers of Lacustrine Subaqueous Landslides in Lake Champlain, USA

NASA Astrophysics Data System (ADS)

Manley, P.; Manley, T.; Ghosh, S. J.; Rosales-Underbrink, P.; Silverhart, P.

2017-12-01

Lacustrine slumps and debris flows (landslides) have been identified in Lake Champlain via Multibeam and CHIRP (compressed high intensity radar pulse) seismic profile data. Numerous large landslides studied by Ghosh (2012), Rosales-Underbrink (2015), and Silverhart (2016) have shown that many of these landslides are coeval. All landslides failed on a specific interface between marine Champlain Sea and modern lacustrine Lake Champlain sediments. Utilizing radionuclide dating on sediment from the unfailed slopes or undisturbed sediment above failed deposits, sedimentation rates were determined and used to calculate the approximate failure ages for each of the landslides studied. The northernmost failure, south of the Bouquet River, occurred about 950-1200 cal yr BP and is the first mass wasting event of this age to be recorded on Lake Champlain. The remaining landslides failed about 4500-5200 cal yr BP and agree with nearby Western Quebec Seismic Zone (WQSZ) with clusters of terrestrial landslides occurring at 1000 and 5000 cal yr BP triggered by large earthquakes (Brooks, 2015) along the same interface. The 5000 cal yr BP event has been attributed to a M 6.4 or greater earthquake within the WQSZ. The coeval landslides observed in Lake Champlain were likely triggered by this same earthquake. Lake tsunami models show that these simultaneous landslide failures can generate surface waves wave that can impact the Lake Champlain shoreline within 3-10 minutes after the earthquake.

Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic

NASA Astrophysics Data System (ADS)

Mienis, F.; Duineveld, G.; Davies, A. J.; Lavaleye, M. J. N.; Ross, S. W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M.; de Haas, H.; Brooke, S.; van Weering, T.

2013-12-01

The Cape Lookout cold-water coral area off the coast of North Carolina forms the shallowest and northernmost cold-water coral mound area on the Blake Plateau in the NW Atlantic. Cold-water coral habitats near Cape Lookout are occasionally bathed in the Gulf Stream, which is characterised by oligotrophic warm water and strong surface currents. Here, we present the first insights into the mound distribution and morphology, sedimentary environment and coral cover and near-bed environmental conditions as recorded by bottom landers from this coral area. The mounds occur between 320-550 m water depth and are characterised by high acoustic backscatter indicating the presence of hard structure. Three distinct mound morphologies were observed, (1) a mound with a flattened top at 320 m, (2) multi-summited mounds with a tear drop shape in the middle part of the area and (3) a single mound at 540 m water depth. Echosounder profiles show the presence of a strong reflector underneath all mound structures that forms the base of the mounds. This reflector cropped out at the downstream side of the single mound and consists of carbonate slabs. Video analysis revealed that all mounds are covered by Lophelia pertusa and that living colonies only occur close to the summits of the SSW side of the mounds, which is the side that faces the strongest currents. Off mound areas were characterised by low backscatter and sediment ripples, indicating the presence of relatively strong bottom currents. Two bottom landers were deployed amidst the coral mounds between December 2009 and May 2010. Both landers recorded prominent features near the seabed as well as in the overlying water column. The period between December and April was characterised by several events of increasing temperature and salinity, coinciding with increased flow and near-bed acoustic backscatter. During these events temperature fluctuated by up to 9 °C within a day, which is the largest temperature variability as measured so far in a cold-water coral habitat. Warm events, related to Gulf Stream meanders, had the duration of roughly one week and the current during these events was directed to the NNE. The consequences of such events must be significant given the strong effects of temperature on the metabolism of cold-water corals. Furthermore, elevated acoustic backscatter values and high mass fluxes were also recorded during these events, indicating a second stressor that may affect the corals. The abrasive nature of sand in combination with strong currents might sand blast the corals. We conclude that cold-water corals near Cape Lookout live under extreme conditions that limit mound growth at present.

Prediction of Coronary Artery Disease Risk Based on Multiple Longitudinal Biomarkers

PubMed Central

Yang, Lili; Yu, Menggang; Gao, Sujuan

2016-01-01

In the last decade, few topics in the area of cardiovascular disease (CVD) research have received as much attention as risk prediction. One of the well documented risk factors for CVD is high blood pressure (BP). Traditional CVD risk prediction models consider BP levels measured at a single time and such models form the basis for current clinical guidelines for CVD prevention. However, in clinical practice, BP levels are often observed and recorded in a longitudinal fashion. Information on BP trajectories can be powerful predictors for CVD events. We consider joint modeling of time to coronary artery disease and individual longitudinal measures of systolic and diastolic BPs in a primary care cohort with up to 20 years of follow-up. We applied novel prediction metrics to assess the predictive performance of joint models. Predictive performances of proposed joint models and other models were assessed via simulations and illustrated using the primary care cohort. PMID:26439685

Response of the Antarctic Stratosphere to Two Types of El Nino Events

NASA Technical Reports Server (NTRS)

Hurwitz, M. M.; Newman, P. A.; Oman, L. D.; Molod, A. M.

2010-01-01

This study is the first to identify a robust El Nino/Southern Oscillation (ENSO) signal in the Antarctic stratosphere. El Nino events are classified as either conventional "cold tongue" events (positive SST anomalies in the Nino 3 region) or "warm pool" events (positive SST anomalies in the Nino 4 region). The ERA-40, NCEP and MERRA meteorological reanalyses are used to show that the Southern Hemisphere stratosphere responds differently to these two types of El Nino events. Consistent with previous studies, "cold tongue" events do not impact temperatures in the Antarctic stratosphere. During "warm pool" El Nino events, the poleward extension and increased strength of the South Pacific Convergence Zone (SPCZ) favor an enhancement of planetary wave activity during the SON season. On average, these conditions lead to higher polar stratospheric temperatures and a weakening of the Antarctic polar jet in November and December, as compared with neutral ENSO years. The phase of the quasi-biennial oscillation (QBO) modulates the stratospheric response to "warm pool" El Nino events: the strongest planetary wave driving events are coincident with the easterly phase of the QBO.

A geochemical record of the link between chemical weathering and the East Asian summer monsoon during the late Holocene preserved in lacustrine sediments from Poyang Lake, central China

NASA Astrophysics Data System (ADS)

Huang, Chao; Wei, Gangjian; Li, Wuxian; Liu, Ying

2018-04-01

This paper presents relatively high-resolution geochemical records spanning the past 4000 cal yr BP obtained from the lacustrine sediments of Poyang Lake in central China. The variations in the intensity of the East Asian summer monsoon (EASM) are traced using the K/Na, Ti/Na, Al/K, kaolinite/illite and clay/feldspar ratios, together with the chemical index of alteration (CIA), as indicators of chemical weathering. During the last 4000 years, the proxy records of chemical weathering from Poyang Lake exhibit an overall enhanced trend, consistent with regional hydrological changes in previous independent records. Further comparisons and analyses demonstrate that regional moisture variations in central China is inversely correlated with the EASM intensity, with weak EASM generating high precipitation in central China. Our data reveal three intervals of dramatically dry climatic conditions (i.e., ca. 4000-3200 cal yr BP, ca. 2800-2400 cal yr BP, and ca. 500-200 cal yr BP). A period of weak chemical weathering, related to cold and dry climatic conditions, occurred during the Little Ice Age (LIA), whereas more intense chemical weathering, reflecting warm and humid climatic conditions, was recorded during the Medieval Warm Period (MWP). Besides, an intensification of chemical weathering in Poyang Lake during the late Holocene agrees well with strong ENSO activity, suggesting that moisture variations in central China may be predominantly driven by ENSO variability.

Revisiting the cold season surge generating storms of the east coast in the 20th century

NASA Astrophysics Data System (ADS)

Lee, D. E.; Kushnir, Y.; Booth, J. F.

2014-12-01

Cold season storms in the East coast of the United States often threaten the coastal livelihood. This is a study to connect the recorded extreme cold season surges with the storms in the past, spanning from the early 20th Century. We find the 20th century reanalysis data (20CR) useful for this study, for its temporal coverage sufficiently overlaps with the modern tidal records. The storm tracks are obtained from the cold season (NDJFMA) sea level pressure field from 20CR, using the popular tracking algorithm by K.Hodges. In seeking for fidelity in the storm data, we made two major efforts: The climatology and the known climate signals imbedded in the track data are verified against those of ERA-interim reanalysis, and against the storms tracked by an independent algorithm (GISS-MCMS). In addition, it is statistically confirmed that the storm tracks and the sea level pressure fields based on 20CR around the east coast area exhibit temporal homogeneity. In the Battery, we select top 100 cold season water displacement events from the 6-hour mean water height data from 1927 to 2012, with linear trend and tide removed. Among the tracks passing close enough to the Battery, we found 91 matches. Distinctive track characteristics stand out when the positive surge events are separated from the negative surge events. More characteristic parameters of the storms are investigated according to further surge classification.

Efficacy and Tolerability of Nilvadipine in Combination with an Angiotensin II Receptor Antagonist in Patients with Essential Hypertension: A Multicenter, Open-Label, Uncontrolled Study

PubMed Central

Noda, Keita; Ideishi, Munehito; Tashiro, Eiichiro; Nakashima, Yoshiyuki; Imamura, Mitsuhide; Seki, Masahiko; Fujino, Masanori; Sou, Toshimitsu; Kohara, Masaki; Kanaya, Hisashi; Saku, Nishiki; Kamei, Ritsu; Yamasaki, Misao; Sakai, Hiroshi; Gondo, Naoki; Saku, Keijiro

2003-01-01

Background: Combination therapy with different classes of antihypertensive drugs often is needed to achieve controlled blood pressure (BP). The combination of an angiotensin II receptor antagonist (AIIA) and a calcium antagonist is a preferred option for reducing uncontrolled BP. Objective: The aim of this study was to assess the clinical efficacy and tolerability of nilvadipine, a dihydropyridine calcium antagonist, in combination with an AIIA. Methods: Patients with essential hypertension whose BP was not controlled by an AIIA alone were eligible for this multicenter, open-label, uncontrolled study. One of 3 AIIAs (candesartan cilexetil, losartan potassium, or valsartan) was given for at least 10 weeks before the addition of nilvadipine (daily dose, 4 or 8 mg orally). This combination therapy was given for 8 weeks. BP and heart rate were measured between 2 and 4 weeks before and 0, 4, and 8 weeks after the start of combination therapy. Adverse events were monitored at each visit. Results: Thirty-one patients (18 women [58.1%], 13 men [41.9%]; mean [SD] age, 58.5 [10.5] years) were enrolled. At weeks 4 and 8 of combination therapy, mean systolic BP (SBP) and diastolic BP (DBP) were significantly decreased (P<0.01) (at week 8, by 22.0 mm Hg and 12.5 mm Hg, respectively). The mean BP-lowering effect did not differ significantly between the 3 AIIAs tested. Pulse pressure also decreased significantly at week 8, by 9.6 mm Hg (P<0.01). The responder rate (ie, the percentage of patients with DBP <90 mm Hg or a decrease in DBP ≥10 mm Hg) was 72.0% at week 8. Three patients experienced a total of 4 adverse events: mild or severe flushing, mild headache, and mild palpitation. All of these symptoms resolved after nilvadipine treatment was discontinued. Conclusions: Nilvadipine in combination with an AIIA showed good antihypertensive efficacy and was well tolerated in the hypertensive patients in this study. This combination also significantly decreased pulse pressure, suggesting that this combination therapy also may have a beneficial effect in elderly patients with isolated systolic hypertension. PMID:25053855

A multi-proxy approach to understanding complex responses of salt-lake catchments to climate variability and human pressure: A Late Quaternary case study from south-eastern, Spain

NASA Astrophysics Data System (ADS)

Jones, Samantha Elsie; Burjachs, Francesc; Ferrer-García, Carlos; Giralt, Santiago; Schulte, Lothar; Fernández-López de Pablo, Javier

2018-03-01

This article focuses on a former salt lake in the upper Vinalopó Valley in south-eastern Spain. The study spans the Late Pleistocene through to the Late Holocene, although with particular focus on the period between 11 ka cal BP and 3000 ka cal BP (which spans the Mesolithic and part of the Bronze Age). High resolution multi-proxy analysis (including pollen, non pollen palynomorphs, grain size, X-ray fluorescence and X-ray diffraction) was undertaken on the lake sediments. The results show strong sensitivity to both long term and small changes in the evaporation/precipitation ratio, affecting the surrounding vegetation composition, lake-biota and sediment geochemistry. To summarise the key findings the main general trends identified include: 1) Hyper-saline conditions and low lake levels at the end of the Late Glacial 2) Increasing wetness and temperatures which witnessed an expansion of mesophilic woodland taxa, lake infilling and the establishment of a more perennial lake system at the onset of the Holocene 3) An increase in solar insolation after 9 ka cal BP which saw the re-establishment of pine forests 4) A continued trend towards increasing dryness (climatic optimum) at 7 ka cal BP but with continued freshwater input 5) An increase in sclerophyllous open woody vegetation (anthropogenic?), and increasing wetness (climatic?) is represented in the lake record between 5.9 and 3 ka cal BP 6) The Holocene was also punctuated by several aridity pulses, the most prominent corresponding to the 8.2 ka cal BP event. These events, despite a paucity of well dated archaeological sites in the surrounding area, likely altered the carrying capacity of this area both regionally and locally, particularly during the Mesolithic-Neolithic transition, in terms of fresh water supply for human/animal consumption, wild plant food reserves and suitable land for crop growth.

Dehydrins from wheat x Thinopyrum ponticum amphiploid increase salinity and drought tolerance under their own inducible promoters without growth retardation.

PubMed

Qin, Yu-Xiang; Qin, Fangyuan

2016-02-01

Dehydrins confer abiotic stress tolerance in seedlings, but few dehydrins have been studied by transgenic analysis under their own promoters in relation to abiotic stress tolerance. Also the inducible promoters for transgenic engineering are limited. In this study, we isolated from wheat three salt-induced YSK2 dehydrin genes and their promoters. The cDNA sequences were 711, 785, and 932 bp in length, encoding proteins containing 133, 166 and 231 amino acids, respectively, and were named TaDHN1, TaDHN2, and TaDHN3. TaDHN2 doesn't contain introns, while the other two genes each contain one. Semi-quantitative reverse transcription PCR analysis revealed all three dehydrin genes are substantially induced by ABA and NaCl, but only TaDHN2 is induced in seedlings by PEG and by cold (4 °C). Regulatory sequences upstream of the first translation codon (775, 1615 and 889 bp) of the three dehydrin genes were also cloned. Cis-element prediction indicated the presence of ABRE and other abiotic-stress-related elements. Histochemical analysis using GUS expression demonstrated that all three promoters were induced by ABA, cold or NaCl. Ectopic over-expression of TaDHN1 or TaDHN3 in Arabidopsis under their own inducible promoters enhanced NaCl- and drought-stress tolerance without growth retardation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

De Novo Assembly and Transcriptome Analysis of Bulb Onion (Allium cepa L.) during Cold Acclimation Using Contrasting Genotypes

PubMed Central

Natarajan, Sathishkumar; Park, Jong-In; Chung, Mi-Young; Nou, Ill-Sup

2016-01-01

Bulb onion (Allium cepa) is the second most widely cultivated and consumed vegetable crop in the world. During winter, cold injury can limit the production of bulb onion. Genomic resources available for bulb onion are still very limited. To date, no studies on heritably durable cold and freezing tolerance have been carried out in bulb onion genotypes. We applied high-throughput sequencing technology to cold (2°C), freezing (-5 and -15°C), and control (25°C)-treated samples of cold tolerant (CT) and cold susceptible (CS) genotypes of A. cepa lines. A total of 452 million paired-end reads were de novo assembled into 54,047 genes with an average length of 1,331 bp. Based on similarity searches, these genes were aligned with entries in the public non-redundant (nr) database, as well as KEGG and COG database. Differentially expressed genes (DEGs) were identified using log10 values with the FPKM method. Among 5,167DEGs, 491 genes were differentially expressed at freezing temperature compared to the control temperature in both CT and CS libraries. The DEG results were validated with qRT-PCR. We performed GO and KEGG pathway enrichment analyses of all DEGs and iPath interactive analysis found 31 pathways including those related to metabolism of carbohydrate, nucleotide, energy, cofactors and vitamins, other amino acids and xenobiotics biodegradation. Furthermore, a large number of molecular markers were identified from the assembled genes, including simple sequence repeats (SSRs) 4,437 and SNP substitutions of transition and transversion types of CT and CS. Our study is the first to provide a transcriptome sequence resource for Allium spp. with regard to cold and freezing stress. We identified a large set of genes and determined their DEG profiles under cold and freezing conditions using two different genotypes. These data represent a valuable resource for genetic and genomic studies of Allium spp. PMID:27627679

De Novo Assembly and Transcriptome Analysis of Bulb Onion (Allium cepa L.) during Cold Acclimation Using Contrasting Genotypes.

PubMed

Han, Jeongsukhyeon; Thamilarasan, Senthil Kumar; Natarajan, Sathishkumar; Park, Jong-In; Chung, Mi-Young; Nou, Ill-Sup

2016-01-01

Bulb onion (Allium cepa) is the second most widely cultivated and consumed vegetable crop in the world. During winter, cold injury can limit the production of bulb onion. Genomic resources available for bulb onion are still very limited. To date, no studies on heritably durable cold and freezing tolerance have been carried out in bulb onion genotypes. We applied high-throughput sequencing technology to cold (2°C), freezing (-5 and -15°C), and control (25°C)-treated samples of cold tolerant (CT) and cold susceptible (CS) genotypes of A. cepa lines. A total of 452 million paired-end reads were de novo assembled into 54,047 genes with an average length of 1,331 bp. Based on similarity searches, these genes were aligned with entries in the public non-redundant (nr) database, as well as KEGG and COG database. Differentially expressed genes (DEGs) were identified using log10 values with the FPKM method. Among 5,167DEGs, 491 genes were differentially expressed at freezing temperature compared to the control temperature in both CT and CS libraries. The DEG results were validated with qRT-PCR. We performed GO and KEGG pathway enrichment analyses of all DEGs and iPath interactive analysis found 31 pathways including those related to metabolism of carbohydrate, nucleotide, energy, cofactors and vitamins, other amino acids and xenobiotics biodegradation. Furthermore, a large number of molecular markers were identified from the assembled genes, including simple sequence repeats (SSRs) 4,437 and SNP substitutions of transition and transversion types of CT and CS. Our study is the first to provide a transcriptome sequence resource for Allium spp. with regard to cold and freezing stress. We identified a large set of genes and determined their DEG profiles under cold and freezing conditions using two different genotypes. These data represent a valuable resource for genetic and genomic studies of Allium spp.

60,000 Year Climate and Vegetation History of Southeast Alaska

NASA Astrophysics Data System (ADS)

Wilcox, Paul S.

Sedimentological and palynological analyses of lacustrine cores from Baker Island, located in Southeast Alaska's Alexander Archipelago, indicate that glaciers persisted on the island until 14,500 cal yr. BP. However, the appearance of tree pollen, including Pinus cf. contorta ssp. contorta (shore pine) and Tsuga mertensiana (mountain hemlock) immediately following deglaciation suggests that a forest refugium may have been present on ice-free portions of neighboring islands or the adjacent continental shelf. Sedimentological and palynological analyses indicate a variable climate during the Younger Dryas interval between 13,000 and 11,500 cal yr. BP, with a cold and dry onset followed by ameliorating conditions during the latter half of the interval. An eight cm-thick black tephra dated to 13,500 +/- 250 cal yr. BP is geochemically distinct from the Mt. Edgecumbe tephra and thus derived from a different volcano. Based on overall thickness, multiple normally graded beds, and grain size, I infer that the black tephra was emplaced by a large strombolian-style paroxysm. Because the dominant wind direction along this coast is from the west, the Addington Volcanic Field on the continental shelf, which would have been subaerially exposed during the eruption, is a potential source. The similarity in timing between this eruption and the Mt. Edgecumbe eruption suggests a shared trigger, possibly a response to unloading as the Cordilleran Ice Sheet retreated. To complement the Baker Island lacustrine record, a speleothem paleoclimate record based on delta13C and delta18O values spanning the interval from 60,000 yr. BP to 11,150 yr. BP was recovered from El Capitan Cave on neighboring Prince of Wales Island. More negative delta13 C values are attributed to predominance of angiosperms in the vegetation above the cave at 22,000 yr. BP and between 53,000 and 46,000 yr. BP while more positive delta13C values in speleothem EC-16-5-F indicate the presence of gymnosperms. These data suggest limited or no ice cover above El Capitan Cave for the duration of the record, possibly indicating that this region was a nunatak during glacial periods.

3-Bromopyruvate induces rapid human prostate cancer cell death by affecting cell energy metabolism, GSH pool and the glyoxalase system.

PubMed

Valenti, Daniela; Vacca, Rosa A; de Bari, Lidia

2015-12-01

3-bromopyruvate (3-BP) is an anti-tumour drug effective on hepatocellular carcinoma and other tumour cell types, which affects both glycolytic and mitochondrial targets, depleting cellular ATP pool. Here we tested 3-BP on human prostate cancer cells showing, differently from other tumour types, efficient ATP production and functional mitochondrial metabolism. We found that 3-BP rapidly induced cultured androgen-insensitive (PC-3) and androgen-responsive (LNCaP) prostate cancer cell death at low concentrations (IC(50) values of 50 and 70 μM, respectively) with a multimodal mechanism of action. In particular, 3-BP-treated PC-3 cells showed a selective, strong reduction of glyceraldeide 3-phosphate dehydrogenase activity, due to the direct interaction of the drug with the enzyme. Moreover, 3-BP strongly impaired both glutamate/malate- and succinate-dependent mitochondrial respiration, membrane potential generation and ATP synthesis, concomitant with the inhibition of respiratory chain complex I, II and ATP synthase activities. The drastic reduction of cellular ATP levels and depletion of GSH pool, associated with significant increase in cell oxidative stress, were found after 3-BP treatment of PC-3 cells. Interestingly, the activity of both glyoxalase I and II, devoted to the elimination of the cytotoxic methylglyoxal, was strongly inhibited by 3-BP. Both N-acetylcysteine and aminoguanidine, GSH precursor and methylglyoxal scavenger, respectively, prevented 3-BP-induced PC-3 cell death, showing that impaired cell antioxidant and detoxifying capacities are crucial events leading to cell death. The provided information on the multi-target cytotoxic action of 3-BP, finally leading to PC-3 cell necrosis, might be useful for future development of 3-BP as a therapeutic option for prostate cancer treatment.

Screening for asymptomatic atrial fibrillation while monitoring the blood pressure at home: trial of regular versus irregular pulse for prevention of stroke (TRIPPS 2.0).

PubMed

Wiesel, Joseph; Abraham, Saji; Messineo, Frank C

2013-06-01

Asymptomatic atrial fibrillation (AF) is a common cause of strokes. Physician screening for AF has been recommended. Home screening for AF may increase the likelihood of detecting asymptomatic AF in patients at risk for stroke because of AF. The aim of this study was to assess the feasibility and accuracy of screening for AF when taking home blood pressure (BP) measurements using an automatic AF-detecting BP monitor. Subjects aged >64 years or those with hypertension, diabetes, congestive heart failure, or previous stroke were enrolled by their primary physicians and given the AF-BP monitor and an electrocardiographic event monitor to use at home for 30 days. The AF-BP monitor reading was compared with the electrocardiographic reading to calculate the sensitivity and specificity of the device for detecting AF. A total of 160 subjects were enrolled, with 10 withdrawing, 1 excluded, and 10 with no AF-BP monitor logs or electrocardiographic recordings. Of the 139 subjects included, 14 had known AF. There was a total of 3,316 days with AF-BP monitor readings and electrocardiographic readings. On the basis of the initial daily AF-BP monitor readings, the AF-BP monitor demonstrated sensitivity of 99.2% and specificity of 92.9% for detecting AF. Two subjects with no histories of AF had AF-BP monitor readings of AF that were confirmed by the electrocardiographic monitor. One of these subjects was started on warfarin. In conclusion, home screening for asymptomatic AF while taking BP measurements can be performed accurately. This can be used to detect new AF, allowing treatment with anticoagulation to reduce the future risk for stroke. Copyright © 2013 Elsevier Inc. All rights reserved.

Holocene climate variability and anthropogenic impacts from Lago Paixban, a perennial wetland in Peten, Guatemala

USGS Publications Warehouse

Wahl, David B.; Hansen, Richard D.; Byrne, Roger; Anderson, Lysanna; Schreiner, T.

2016-01-01

Analyses of an ~ 6 m sediment core from Lago Paixban in Peten, Guatemala, document the complex evolution of a perennial wetland over the last 10,300 years. The basal sediment is comprised of alluvial/colluvial fill deposited in the early Holocene. The absence of pollen and gastropods in the basal sediments suggests intermittently dry conditions until ~ 9000 cal yr. BP (henceforth BP) when the basin began to hold water perennially. Lowland tropical forest taxa dominated the local vegetation at this time. A distinct band of carbonate dating to ~ 8200 BP suggests regionally dry conditions, possibly associated with the 8.2 ka event. Wetter conditions during the Holocene Thermal Maximum are indicated by evidence of a raised water level and an open water lake. The timing of this interval coincides with strengthening of the Central American Monsoon. An abrupt change at 5500 BP involved the development of a sawgrass marsh and onset of peat deposition. The lowest recorded water levels date to 5500–4500 BP. Pollen, isotope, geochemical, and sedimentological data indicate that the coring site was near the edge of the marsh during this period. A rise in the water table after 4500 BP persisted until around 3500 BP. Clay marl deposition from 3500 to 210 BP corresponds to the period of Maya settlement. An increase in δ13C, the presence of Zea pollen, and a reduction in the percentage of forest taxa pollen indicate agricultural activity at this time. In contrast to several nearby paleoenvironmental studies, proxy evidence from Lago Paixban indicates human presence through the Classic/Postclassic period transition (~ 1000 BP) and persisting until the arrival of Europeans. Cessation of human activity around 210 BP resulted in local afforestation and the re-establishment of the current sawgrass marsh at Lago Paixban.

Holocene climate variability and anthropogenic impacts from Lago Paixban, a perennial wetland in Peten, Guatemala

NASA Astrophysics Data System (ADS)

Wahl, David; Hansen, Richard D.; Byrne, Roger; Anderson, Lysanna; Schreiner, Thomas

2016-03-01

Analyses of an 6 m sediment core from Lago Paixban in Peten, Guatemala, document the complex evolution of a perennial wetland over the last 10,300 years. The basal sediment is comprised of alluvial/colluvial fill deposited in the early Holocene. The absence of pollen and gastropods in the basal sediments suggests intermittently dry conditions until 9000 cal yr. BP (henceforth BP) when the basin began to hold water perennially. Lowland tropical forest taxa dominated the local vegetation at this time. A distinct band of carbonate dating to 8200 BP suggests regionally dry conditions, possibly associated with the 8.2 ka event. Wetter conditions during the Holocene Thermal Maximum are indicated by evidence of a raised water level and an open water lake. The timing of this interval coincides with strengthening of the Central American Monsoon. An abrupt change at 5500 BP involved the development of a sawgrass marsh and onset of peat deposition. The lowest recorded water levels date to 5500-4500 BP. Pollen, isotope, geochemical, and sedimentological data indicate that the coring site was near the edge of the marsh during this period. A rise in the water table after 4500 BP persisted until around 3500 BP. Clay marl deposition from 3500 to 210 BP corresponds to the period of Maya settlement. An increase in δ13C, the presence of Zea pollen, and a reduction in the percentage of forest taxa pollen indicate agricultural activity at this time. In contrast to several nearby paleoenvironmental studies, proxy evidence from Lago Paixban indicates human presence through the Classic/Postclassic period transition ( 1000 BP) and persisting until the arrival of Europeans. Cessation of human activity around 210 BP resulted in local afforestation and the re-establishment of the current sawgrass marsh at Lago Paixban.

Effect of azilsartan versus candesartan on morning blood pressure surges in Japanese patients with essential hypertension

PubMed Central

Kario, Kazuomi; Enya, Kazuaki; Sugiura, Kenkichi; Ikeda, Yoshinori

2014-01-01

Morning blood pressure (BP) surge is reported as a risk factor for cardiovascular events and end-organ damage independent of the 24-h BP level. Controlling morning BP surge is therefore important to help prevent onset of cardiovascular disease. We compared the efficacy of azilsartan and candesartan in controlling morning systolic BP (SBP) surges by analyzing relevant ambulatory BP monitoring data in patients with/without baseline BP surges. As part of a 16-week randomized, double-blind study of azilsartan (20–40 mg once daily) and candesartan (8–12 mg once daily) in Japanese patients with essential hypertension, an exploratory analysis was carried out using ambulatory BP monitoring at baseline and week 14. The effects of study drugs on morning BP surges, including sleep trough surge (early morning SBP minus the lowest night-time SBP) and prewaking surge (early morning SBP minus SBP before awakening), were evaluated. Patients with sleep trough surge of at least 35 mmHg were defined by the presence of a morning BP surge (the ‘surge group’). Sleep trough surge and prewaking surge data were available at both baseline and week 14 in 548 patients, 147 of whom (azilsartan 76; candesartan 71) had a baseline morning BP surge. In surge group patients, azilsartan significantly reduced both the sleep trough surge and the prewaking surge at week 14 compared with candesartan (least squares means of the between-group differences −5.8 mmHg, P=0.0395; and −5.7 mmHg, P=0.0228, respectively). Once-daily azilsartan improved sleep trough surge and prewaking surge to a greater extent than candesartan in Japanese patients with grade I–II essential hypertension. PMID:24710336

Effect of azilsartan versus candesartan on morning blood pressure surges in Japanese patients with essential hypertension.

PubMed

Rakugi, Hiromi; Kario, Kazuomi; Enya, Kazuaki; Sugiura, Kenkichi; Ikeda, Yoshinori

2014-06-01

Morning blood pressure (BP) surge is reported as a risk factor for cardiovascular events and end-organ damage independent of the 24-h BP level. Controlling morning BP surge is therefore important to help prevent onset of cardiovascular disease. We compared the efficacy of azilsartan and candesartan in controlling morning systolic BP (SBP) surges by analyzing relevant ambulatory BP monitoring data in patients with/without baseline BP surges. As part of a 16-week randomized, double-blind study of azilsartan (20-40 mg once daily) and candesartan (8-12 mg once daily) in Japanese patients with essential hypertension, an exploratory analysis was carried out using ambulatory BP monitoring at baseline and week 14. The effects of study drugs on morning BP surges, including sleep trough surge (early morning SBP minus the lowest night-time SBP) and prewaking surge (early morning SBP minus SBP before awakening), were evaluated. Patients with sleep trough surge of at least 35 mmHg were defined by the presence of a morning BP surge (the 'surge group'). Sleep trough surge and prewaking surge data were available at both baseline and week 14 in 548 patients, 147 of whom (azilsartan 76; candesartan 71) had a baseline morning BP surge. In surge group patients, azilsartan significantly reduced both the sleep trough surge and the prewaking surge at week 14 compared with candesartan (least squares means of the between-group differences -5.8 mmHg, P=0.0395; and -5.7 mmHg, P=0.0228, respectively). Once-daily azilsartan improved sleep trough surge and prewaking surge to a greater extent than candesartan in Japanese patients with grade I-II essential hypertension.

Adverse childhood experiences and blood pressure trajectories from childhood to young adulthood: the Georgia stress and Heart study.

PubMed

Su, Shaoyong; Wang, Xiaoling; Pollock, Jennifer S; Treiber, Frank A; Xu, Xiaojing; Snieder, Harold; McCall, W Vaughn; Stefanek, Michael; Harshfield, Gregory A

2015-05-12

The purposes of this study were to assess the long-term effect of adverse childhood experiences (ACEs) on blood pressure (BP) trajectories from childhood to young adulthood and to examine whether this relation is explained by childhood socioeconomic status (SES) or risk behaviors that are associated with ACEs. Systolic and diastolic BPs were measured up to 16 times (13 times on average) over a 23-year period in 213 African Americans and 181 European Americans 5 to 38 years of age. Retrospective data on traumatic experiences before 18 years of age were collected, including abuse, neglect, and household dysfunction. Individual growth curve modeling within a multilevel framework was used to examine the relation between exposure to ACEs and BP development. No main effect of ACEs on average BP levels was found. However, a significant interaction of ACE score with age(3) was observed (systolic BP, P=0.033; diastolic BP, P=0.017). Subjects who experienced multiple traumatic events during childhood showed a faster rise in BP levels after 30 years of age than those without ACEs. As expected, a graded association of ACEs with childhood socioeconomic status and negative health behaviors was observed (P<0.001). The ACE-systolic BP relation was not explained by these factors, whereas the ACE-diastolic BP relation was partially mediated by illicit drug use. In this novel longitudinal study, we observed that participants who were exposed to multiple ACEs displayed a greater increase in BP levels in young adulthood compared with their counterparts without ACEs. © 2015 American Heart Association, Inc.

Improving blood pressure control: increase the dose of diuretic or switch to a fixed-dose angiotensin receptor blocker/diuretic? the valsartan hydrochlorothiazide diuretic for initial control and titration to achieve optimal therapeutic effect (Val-DICTATE) trial.

PubMed

White, William B; Calhoun, David A; Samuel, Rita; Taylor, Addison A; Zappe, Dion H; Purkayastha, Das

2008-06-01

To assess the strategy of increasing the dose of a diuretic compared with using an angiotensin receptor blocker in combination with a diuretic, the authors performed a multicenter, randomized, parallel group trial in hypertensive patients (baseline blood pressure [BP], 153/97 mm Hg) whose BP remained uncontrolled on initial low-dose diuretic monotherapy (hydrochlorothiazide [HCTZ] 12.5 mg Hg). Patients with stage 1 and 2 hypertension were randomized to treatment with valsartan/HCTZ (160/12.5 mg) or to doubling of the HCTZ dose (25 mg). The primary end point was the percentage of patients whose clinic BP values were <140/90 mm Hg following 4 weeks of double-blind therapy. A significantly higher proportion (P<.001) of hypertensive patients met BP control levels in the valsartan/HCTZ (160/12.5 mg) group compared with the HCTZ 25 mg group (37% vs 16%). Changes from baseline in BP were significantly greater (P<.001) for both systolic BP and diastolic BP in the combination therapy arm compared with the diuretic monotherapy arm (-12. 4/-7.5 mm Hg in valsartan/HCTZ 160/12.5 mg group vs -5.6/-2.1 mm Hg in HCTZ 25 mg group). Tolerability and adverse events were similar in the 2 treatment groups. This study suggests that in the management of hypertension, utilizing an angiotensin receptor blocker/diuretic combination was more effective in lowering BP and achieving BP goals when compared with increasing the dose of the diuretic.

Climatic and cultural changes in the west Congo Basin forests over the past 5000 years

PubMed Central

Oslisly, Richard; White, Lee; Bentaleb, Ilham; Favier, Charly; Fontugne, Michel; Gillet, Jean-François; Sebag, David

2013-01-01

Central Africa includes the world's second largest rainforest block. The ecology of the region remains poorly understood, as does its vegetation and archaeological history. However, over the past 20 years, multidisciplinary scientific programmes have enhanced knowledge of old human presence and palaeoenvironments in the forestry block of Central Africa. This first regional synthesis documents significant cultural changes over the past five millennia and describes how they are linked to climate. It is now well documented that climatic conditions in the African tropics underwent significant changes throughout this period and here we demonstrate that corresponding shifts in human demography have had a strong influence on the forests. The most influential event was the decline of the strong African monsoon in the Late Holocene, resulting in serious disturbance of the forest block around 3500 BP. During the same period, populations from the north settled in the forest zone; they mastered new technologies such as pottery and fabrication of polished stone tools, and seem to have practised agriculture. The opening up of forests from 2500 BP favoured the arrival of metallurgist populations that impacted the forest. During this long period (2500–1400 BP), a remarkable increase of archaeological sites is an indication of a demographic explosion of metallurgist populations. Paradoxically, we have found evidence of pearl millet (Pennisetum glaucum) cultivation in the forest around 2200 BP, implying a more arid context. While Early Iron Age sites (prior to 1400 BP) and recent pre-colonial sites (two to eight centuries BP) are abundant, the period between 1600 and 1000 BP is characterized by a sharp decrease in human settlements, with a population crash between 1300 and 1000 BP over a large part of Central Africa. It is only in the eleventh century that new populations of metallurgists settled into the forest block. In this paper, we analyse the spatial and temporal distribution of 328 archaeological sites that have been reliably radiocarbon dated. The results allow us to piece together changes in the relationships between human populations and the environments in which they lived. On this basis, we discuss interactions between humans, climate and vegetation during the past five millennia and the implications of the absence of people from the landscape over three centuries. We go on to discuss modern vegetation patterns and African forest conservation in the light of these events. PMID:23878334

Temperature Studies with the Asian Citrus Psyllid, Diaphorina citri: Cold Hardiness and Temperature Thresholds for Oviposition

PubMed Central

Hall, David G.; Wenninger, Erik J.; Hentz, Matthew G.

2011-01-01

This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most serious citrus disease worldwide. D. citri was first found in Florida during 1998, and the disease was discovered during 2005. Little was known regarding cold hardiness of D. citri, but Florida citrus is occasionally subjected to notable freeze events. Temperature and duration were each significant sources of variation in percent mortality of D. citri subjected to freeze events. Relatively large percentages of adults and nymphs survived after being exposed for several hours to temperatures as low as -5 to -6° C. Relatively large percentages of eggs hatched after being exposed for several hours to temperatures as low as -8° C. Research results indicated that adult D. citri become cold acclimated during the winter through exposure to cooler winter temperatures. There was no evidence that eggs became cold acclimated during winter. Cold acclimation in nymphs was not investigated. Research with adult D. citri from laboratory and greenhouse colonies revealed that mild to moderate freeze events were usually nonlethal to the D. citri irrespective of whether they were cold acclimated or not. Upper and lower temperature thresholds for oviposition were investigated because such information may be valuable in explaining the geographic distribution and potential spread of the pest from Florida as well as how cooler winter temperatures might limit population growth. The estimated lower and upper thresholds for oviposition were 16.0 and 41.6° C, respectively; the estimated temperature of peak oviposition over a 48 h period was 29.6° C. PMID:21870969

Temperature studies with the Asian citrus psyllid, Diaphorina citri: cold hardiness and temperature thresholds for oviposition.

PubMed

Hall, David G; Wenninger, Erik J; Hentz, Matthew G

2011-01-01

This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most serious citrus disease worldwide. D. citri was first found in Florida during 1998, and the disease was discovered during 2005. Little was known regarding cold hardiness of D. citri, but Florida citrus is occasionally subjected to notable freeze events. Temperature and duration were each significant sources of variation in percent mortality of D. citri subjected to freeze events. Relatively large percentages of adults and nymphs survived after being exposed for several hours to temperatures as low as -5 to -6 °C. Relatively large percentages of eggs hatched after being exposed for several hours to temperatures as low as -8 °C. Research results indicated that adult D. citri become cold acclimated during the winter through exposure to cooler winter temperatures. There was no evidence that eggs became cold acclimated during winter. Cold acclimation in nymphs was not investigated. Research with adult D. citri from laboratory and greenhouse colonies revealed that mild to moderate freeze events were usually nonlethal to the D. citri irrespective of whether they were cold acclimated or not. Upper and lower temperature thresholds for oviposition were investigated because such information may be valuable in explaining the geographic distribution and potential spread of the pest from Florida as well as how cooler winter temperatures might limit population growth. The estimated lower and upper thresholds for oviposition were 16.0 and 41.6 °C, respectively; the estimated temperature of peak oviposition over a 48 h period was 29.6 °C.

Late-glacial and early Holocene changes in vegetation and lake-level at Hauterive/Rouges-Terres, Lake Neuchâtel (Switzerland)

NASA Astrophysics Data System (ADS)

Magny, Michel; Thew, Nigel; Hadorn, Philippe

2003-01-01

Palynological and sedimentological analyses of a sedimentary sequence sampled at Hauterive/Rouges-Terres, Lake Neuchâtel (Switzerland) provide documentation of changes in vegetation and lake-level during the Bølling, Younger Dryas and Preboreal pollen zones, and have allowed a comparison with sequences covering the same period from other sites located in the western part of the Swiss Plateau. The Juniperus-Hippophaë zone (regional pollen assemblage zone (RPAZ) CHb-2, first part of the Bølling, ca. 14 650-14 450 cal. yr BP) was characterised by a generally low lake-level. A weak rise occurred during this zone. The Juniperus-Hippophaë to Betula zone transition coincided with a lake-level lowering, interrupted by a short-lived but marked phase of higher lake-level recorded at the neighbouring site of Hauterive-Champréveyres, but not present at Hauterive/Rouges-Terres owing to an erosion surface. Shortly after the beginning of the Betula zone (RPAZ CHb-3, second part of the Bølling, ca 14 450-14 000 cal. yr BP), a marked rise in lake-level occurred. It was composed of two successive periods of higher level, coinciding with high values of Betula, separated by a short episode of relatively lower lake-level associated with raised values in Artemisia and other non-arboreal pollen. The last part of RPAZ CHb-3 saw a fall in lake-level. The lower lake-levels during RPAZ CHb-2 to early RPAZ CHb-3 can be correlated with the abrupt warming at the beginning of the Greenland Interstadial (GI) 1e thermal maximum. The successive episodes of higher lake-level punctuating the GI 1e might be linked to the so-called Intra-Bølling Cold Oscillations identified from several palaeoclimatic records in the North Atlantic area, and also documented in oxygen-isotope data sets from Swiss Plateau lakes. The Hauterive/Rouges-Terres lake-level record provides evidence for marked climatic drying through the second part of the Younger Dryas event (GS1), during the GS1-Preboreal (RPAZ CHb-4b-4c) transition (except for a rise at ca. 11 450-11 400 cal. yr BP), and at the RPAZ CHb-4c-5 (Preboreal-Boreal) transition, following the Preboreal Oscillation (after 11 150 cal. yr BP). The Preboreal Oscillation coincided with higher lake-levels, its end being followed by a rapid expansion of Corylus, Quercus, Ulmus and Tilia. The Hauterive/Rouges-Terres lake-level record suggests that radiocarbon plateau at 12 600, 10 000 and 9500 14C yr BP corresponded to periods of generally lower lake-level. This suggests that an increase in solar activity may have contributed to both climatic dryness and a decrease in atmospheric radiocarbon content.

Vaccines for the common cold.

PubMed

Simancas-Racines, Daniel; Franco, Juan Va; Guerra, Claudia V; Felix, Maria L; Hidalgo, Ricardo; Martinez-Zapata, Maria José

2017-05-18

The common cold is a spontaneously remitting infection of the upper respiratory tract, characterised by a runny nose, nasal congestion, sneezing, cough, malaise, sore throat, and fever (usually < 37.8º C). The widespread morbidity caused by the common cold worldwide is related to its ubiquitousness rather than its severity. The development of vaccines for the common cold has been difficult because of antigenic variability of the common cold virus and the indistinguishable multiple other viruses and even bacteria acting as infective agents. There is uncertainty regarding the efficacy and safety of interventions for preventing the common cold in healthy people. This is an update of a Cochrane review first published in 2011 and previously updated in 2013. To assess the clinical effectiveness and safety of vaccines for preventing the common cold in healthy people. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (September 2016), MEDLINE (1948 to September 2016), Embase (1974 to September 2016), CINAHL (1981 to September 2016), and LILACS (1982 to September 2016). We also searched three trials registers for ongoing studies and four websites for additional trials (February 2017). We included no language or date restrictions. Randomised controlled trials (RCTs) of any virus vaccines compared with placebo to prevent the common cold in healthy people. Two review authors independently evaluated methodological quality and extracted trial data. We resolved disagreements by discussion or by consulting a third review author. We found no additional RCTs for inclusion in this update. This review includes one RCT dating from the 1960s with an overall high risk of bias. The RCT included 2307 healthy participants, all of whom were included in analyses. This trial compared the effect of an adenovirus vaccine against placebo. No statistically significant difference in common cold incidence was found: there were 13 (1.14%) events in 1139 participants in the vaccines group and 14 (1.19%) events in 1168 participants in the placebo group (risk ratio 0.95, 95% confidence interval 0.45 to 2.02; P = 0.90). No adverse events related to the live vaccine were reported. The quality of the evidence was low due to limitations in methodological quality and a wide 95% confidence interval. This Cochrane Review was based on one study with low-quality evidence. We found no conclusive results to support the use of vaccines for preventing the common cold in healthy people compared with placebo. We identified a need for well-designed, adequately powered RCTs to investigate vaccines for the common cold in healthy people. Any future trials on medical treatments for preventing the common cold should assess a variety of virus vaccines for this condition. Outcome measures should include common cold incidence, vaccine safety, and mortality related to the vaccine.

BP, Cardiovascular Disease, and Death in the Folic Acid for Vascular Outcome Reduction in Transplantation Trial

PubMed Central

John, Alin; Weir, Matthew R.; Smith, Stephen R.; Hunsicker, Lawrence; Kasiske, Bertram L.; Kusek, John W.; Bostom, Andrew; Ivanova, Anastasia; Levey, Andrew S.; Solomon, Scott; Pesavento, Todd; Weiner, Daniel E.

2014-01-01

The optimal BP level in kidney transplant recipients remains uncertain. This post hoc analysis of the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) trial cohort assessed associations of BP with a pooled cardiovascular disease (CVD) outcome and with all-cause mortality. In 3474 prevalent kidney transplant patients, mean age was 52±9 years, 63% were men, 76% were white, 20% had a history of CVD, 40% had a history of diabetes mellitus, and the median time since transplant was 4.1 years (25th to 75th percentiles, 1.7–7.4); mean systolic BP was 136±20 mmHg and mean diastolic BP was 79±12 mmHg. There were 497 CVD events and 406 deaths. After adjustment for demographic and transplant characteristics and CVD risk factors, each 20-mmHg increase in baseline systolic BP associated with a 32% increase in subsequent CVD risk (hazard ratio [HR], 1.32; 95% confidence interval [95% CI], 1.19 to 1.46) and a 13% increase in mortality risk (HR, 1.13; 95% CI, 1.01 to 1.27). Similarly, after adjustment, at diastolic BP levels<70 mmHg, each 10-mmHg decrease in diastolic BP level associated with a 31% increase in CVD risk (HR, 1.31; 95% CI, 1.06 to 1.62) and a 31% increase in mortality risk (HR, 1.31; 95% CI, 1.03 to 1.66). However, at diastolic BP levels>70 mmHg, there was no significant relationship between diastolic BP and outcomes. Higher systolic BP strongly and independently associated with increased risk of CVD and all-cause mortality, without evidence of a J shape, whereas only lower levels of diastolic BP associated with increased risk of CVD and death in this trial. PMID:24627349

Constitutive activation of alternative nuclear factor kappa B pathway in canine diffuse large B-cell lymphoma contributes to tumor cell survival and is a target of new adjuvant therapies.

PubMed

Seelig, Davis M; Ito, Daisuke; Forster, Colleen L; Yoon, Una A; Breen, Matthew; Burns, Linda J; Bachanova, Veronika; Lindblad-Toh, Kerstin; O'Brien, Timothy D; Schmechel, Stephen C; Rizzardi, Anthony E; Modiano, Jaime F; Linden, Michael A

2017-07-01

Activation of the classical nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) pathway is a common molecular event observed in both human and canine diffuse large B-cell lymphoma (DLBCL). Although the oncogenic potential of the alternative NFκB pathway (ANFκBP) has also been recently identified in DLBCL, its precise role in tumor pathogenesis and potential as a treatment target is understudied. We hypothesized that up-regulation of the ANFκBP plays an important role in the proliferation and survival of canine DLBCL cells, and we demonstrate that the ANFκBP is constitutively active in primary canine DLBCL samples and a cell line (CLBL1). We further demonstrate that a small interfering RNA inhibits the activation of the NFκB pathway and induces apoptosis in canine DLBCL cells. In conclusion, the ANFκBP facilitates survival of canine DLBCL cells, and thus, dogs with spontaneous DLBCL can provide a useful large animal model to study therapies targeting the ANFκBP.

Drug treatment of hypertension in older patients with diabetes mellitus.

PubMed

Yandrapalli, Srikanth; Pal, Suman; Nabors, Christopher; Aronow, Wilbert S

2018-05-01

Hypertension is more prevalent in the elderly (age>65 years) diabetic population than in the general population and shows an increasing prevalence with advancing age. Both diabetes mellitus (DM) and hypertension are independent risk factors for cardiovascular (CV) related morbidity and mortality. Optimal BP targets were not identified in elderly patients with DM and hypertension. Areas covered: In this review article, the authors briefly discuss the pathophysiology of hypertension in elderly diabetics, present evidence with various antihypertensive drug classes supporting the treatment of hypertension to reduce CV events in older diabetics, and then discuss the optimal target BP goals in these patients. Expert opinion: Clinicians should have a BP goal of less than 130/80 mm in all elderly patients with hypertension and DM, especially in those with high CV-risk. When medications are required for optimal BP control in addition to lifestyle measures, either thiazide diuretics, angiotensin-converting-enzyme inhibitors, angiotensin receptor blockers, or calcium channel blockers should be considered as initial therapy. Combinations of medications are usually required in these patients because BP control is more difficult to achieve in diabetics than those without DM.

Mass-movement and flood-induced deposits in Lake Ledro, southern Alps, Italy: implications for Holocene palaeohydrology and natural hazards

NASA Astrophysics Data System (ADS)

Simonneau, A.; Chapron, E.; Vannière, B.; Wirth, S. B.; Gilli, A.; Di Giovanni, C.; Anselmetti, F. S.; Desmet, M.; Magny, M.

2013-03-01

High-resolution seismic profiles and sediment cores from Lake Ledro combined with soil and riverbed samples from the lake's catchment area are used to assess the recurrence of natural hazards (earthquakes and flood events) in the southern Italian Alps during the Holocene. Two well-developed deltas and a flat central basin are identified on seismic profiles in Lake Ledro. Lake sediments have been finely laminated in the basin since 9000 cal. yr BP and frequently interrupted by two types of sedimentary events (SEs): light-coloured massive layers and dark-coloured graded beds. Optical analysis (quantitative organic petrography) of the organic matter present in soil, riverbed and lacustrine samples together with lake sediment bulk density and grain-size analysis illustrate that light-coloured layers consist of a mixture of lacustrine sediments and mainly contain algal particles similar to the ones observed in background sediments. Light-coloured layers thicker than 1.5 cm in the main basin of Lake Ledro are synchronous to numerous coeval mass-wasting deposits remoulding the slopes of the basin. They are interpreted as subaquatic mass-movements triggered by historical and pre-historical regional earthquakes dated to AD 2005, AD 1891, AD 1045 and 1260, 2545, 2595, 3350, 3815, 4740, 7190, 9185 and 11 495 cal. yr BP. Dark-coloured SEs develop high-amplitude reflections in front of the deltas and in the deep central basin. These beds are mainly made of terrestrial organic matter (soils and lignocellulosic debris) and are interpreted as resulting from intense hyperpycnal flood event. Mapping and quantifying the amount of soil material accumulated in the Holocene hyperpycnal flood deposits of the sequence allow estimating that the equivalent soil thickness eroded over the catchment area reached up to 5 mm during the largest Holocene flood events. Such significant soil erosion is interpreted as resulting from the combination of heavy rainfall and snowmelt. The recurrence of flash flood events during the Holocene was, however, not high enough to affect pedogenesis processes and highlight several wet regional periods during the Holocene. The Holocene period is divided into four phases of environmental evolution. Over the first half of the Holocene, a progressive stabilization of the soils present through the catchment of Lake Ledro was associated with a progressive reforestation of the area and only interrupted during the wet 8.2 event when the soil destabilization was particularly important. Lower soil erosion was recorded during the mid-Holocene climatic optimum (8000-4200 cal. yr BP) and associated with higher algal production. Between 4200 and 3100 cal. yr BP, both wetter climate and human activities within the drainage basin drastically increased soil erosion rates. Finally, from 3100 cal. yr BP to the present-day, data suggest increasing and changing human land use.

Frequent eruptions of Mount Rainier over the last ∼2,600 years

USGS Publications Warehouse

Sisson, T.W.; Vallance, J.W.

2009-01-01

Field, geochronologic, and geochemical evidence from proximal fine-grained tephras, and from limited exposures of Holocene lava flows and a small pyroclastic flow document ten–12 eruptions of Mount Rainier over the last 2,600 years, contrasting with previously published evidence for only 11–12 eruptions of the volcano for all of the Holocene. Except for the pumiceous subplinian C event of 2,200 cal year BP, the late-Holocene eruptions were weakly explosive, involving lava effusions and at least two block-and-ash pyroclastic flows. Eruptions were clustered from ∼2,600 to ∼2,200 cal year BP, an interval referred to as the Summerland eruptive period that includes the youngest lava effusion from the volcano. Thin, fine-grained tephras are the only known primary volcanic products from eruptions near 1,500 and 1,000 cal year BP, but these and earlier eruptions were penecontemporaneous with far-traveled lahars, probably created from newly erupted materials melting snow and glacial ice. The most recent magmatic eruption of Mount Rainier, documented geochemically, was the 1,000 cal year BP event. Products from a proposed eruption of Mount Rainier between AD 1820 and 1854 (X tephra of Mullineaux (US Geol Surv Bull 1326:1–83, 1974)) are redeposited C tephra, probably transported onto young moraines by snow avalanches, and do not record a nineteenth century eruption. We found no conclusive evidence for an eruption associated with the clay-rich Electron Mudflow of ∼500 cal year BP, and though rare, non-eruptive collapse of unstable edifice flanks remains as a potential hazard from Mount Rainier.

A randomized controlled trial to compare the safety and effectiveness of doxycycline (200 mg daily) with oral prednisolone (0.5 mg kg(-1) daily) for initial treatment of bullous pemphigoid: a protocol for the Bullous Pemphigoid Steroids and Tetracyclines (BLISTER) Trial.

PubMed

Chalmers, J R; Wojnarowska, F; Kirtschig, G; Nunn, A J; Bratton, D J; Mason, J; Foster, K A; Whitham, D; Williams, H C

2015-07-01

Bullous pemphigoid (BP) is the most common autoimmune blistering disease in older people, and is associated with significant morbidity and mortality. Oral corticosteroids are usually effective but the side-effects are thought to contribute to the high morbidity and mortality rate. Treatment with oral tetracyclines may be effective but high-quality, randomized controlled trials (RCTs) are needed to confirm this. To compare the effectiveness and safety of two strategies for treating BP. This is a two-arm, parallel group, 52-week RCT comparing doxycycline with prednisolone for initial treatment of BP. Dose is fixed for the initial 6 weeks of treatment (doxycycline 200 mg daily; prednisolone 0.5 mg kg(-1) daily), after which it can be adjusted according to need. A total of 256 patients with BP will be recruited in the U.K. and Germany. The primary outcomes are: (i) effectiveness (assessor-blinded blister count at 6 weeks) and (ii) safety [proportion of patients experiencing ≥ grade 3 adverse events (i.e. severe, life: threatening or fatal) related to trial medication during the year of follow-up]. Primary effectiveness analysis will be an assessment of whether doxycycline can be considered noninferior to prednisolone after 6 weeks of treatment. Primary safety analysis is a superiority analysis at 12 months. Secondary outcomes include longer-term assessment of effectiveness, relapse rates, the proportion of patients experiencing any grade of adverse events related to treatment, quality of life and cost-effectiveness. The trial will provide good evidence for whether the strategy of starting BP treatment with doxycycline is a useful alternative to prednisolone. © 2015 British Association of Dermatologists.

Human activity accelerating the rapid desertification of the Mu Us Sandy Lands, North China.

PubMed

Miao, Yunfa; Jin, Heling; Cui, Jianxin

2016-03-10

Over the past several thousand years, arid and semiarid China has experienced a series of asynchronous desertification events in its semiarid sandy and desert regions, but the precise identification of the driving forces of such events has remained elusive. In this paper we identify two rapid desertification events (RDEs) at ~4.6 ± 0.2 ka BP and ~3.3 ± 0.2 ka BP from the JJ Profile, located in the eastern Mu Us Sandy Lands. These RDEs appear to have occurred immediately following periods marked by persistently frequent and intense fires. We argue that such fire patterns, directly linked to an uncontrolled human use of vegetation as fuel, played a key role in accelerating RDEs by ensuring that the land surface was degraded beyond the threshold required for rapid desertification. This would suggest that the future use of a massive and sustained ecological program of vegetation rehabilitation should reduce the risk of destructive fire.

Human activity accelerating the rapid desertification of the Mu Us Sandy Lands, North China

PubMed Central

Miao, Yunfa; Jin, Heling; Cui, Jianxin

2016-01-01

Over the past several thousand years, arid and semiarid China has experienced a series of asynchronous desertification events in its semiarid sandy and desert regions, but the precise identification of the driving forces of such events has remained elusive. In this paper we identify two rapid desertification events (RDEs) at ~4.6 ± 0.2 ka BP and ~3.3 ± 0.2 ka BP from the JJ Profile, located in the eastern Mu Us Sandy Lands. These RDEs appear to have occurred immediately following periods marked by persistently frequent and intense fires. We argue that such fire patterns, directly linked to an uncontrolled human use of vegetation as fuel, played a key role in accelerating RDEs by ensuring that the land surface was degraded beyond the threshold required for rapid desertification. This would suggest that the future use of a massive and sustained ecological program of vegetation rehabilitation should reduce the risk of destructive fire. PMID:26961705

Impacts of an Extreme Early-Season Freeze Event in the Interior Pacific Northwest (30 October-3 November 2002) on Western Juniper Woodlands.

NASA Astrophysics Data System (ADS)

Knapp, Paul A.; Soulé, Peter T.

2005-07-01

In mid-autumn 2002, an exceptional 5-day cold spell affected much of the interior Pacific Northwest, with minimum temperatures averaging 13°C below long-term means (1953-2002). On 31 October, minimum temperature records occurred at 98 of the 106 recording stations, with records lowered in some locations by 9°C. Calculation of recurrence intervals of minimum temperatures shows that 50% of the stations experienced a >500-yr event. The synoptic conditions responsible were the development of a pronounced high pressure ridge over western Canada and an intense low pressure area centered in the Intermountain West that promoted strong northeasterly winds. The cold spell occurred near the end of the growing season for an ecologically critical and dominant tree species of the interior Pacific Northwest—western juniper—and followed an extended period of severe drought. In spring 2003, it became apparent that the cold had caused high rates of tree mortality and canopy dieback in a species that is remarkable for its longevity and resistance to climatic stress. The cold event altered western juniper dominance in some areas, and this alteration may have long-term impacts on water budgets, fire intensities and frequencies, animal species interrelationships, and interspecific competition among plant species.

Descriptors of natural thermal regimes in streams and their responsiveness to change in the Pacific Northwest of North America

USGS Publications Warehouse

Arismendi, Ivan; Johnson, Sherri L.; Dunham, Jason B.; Haggerty, Roy

2013-01-01

1. Temperature is a major driver of ecological processes in stream ecosystems, yet the dynamics of thermal regimes remain poorly described. Most work has focused on relatively simple descriptors that fail to capture the full range of conditions that characterise thermal regimes of streams across seasons or throughout the year. 2. To more completely describe thermal regimes, we developed several descriptors of magnitude, variability, frequency, duration and timing of thermal events throughout a year. We evaluated how these descriptors change over time using long-term (1979–2009), continuous temperature data from five relatively undisturbed cold-water streams in western Oregon, U.S.A. In addition to trends for each descriptor, we evaluated similarities among them, as well as patterns of spatial coherence, and temporal synchrony. 3. Using different groups of descriptors, we were able to more fully capture distinct aspects of the full range of variability in thermal regimes across space and time. A subset of descriptors showed both higher coherence and synchrony and, thus, an appropriate level of responsiveness to examine evidence of regional climatic influences on thermal regimes. Most notably, daily minimum values during winter–spring were the most responsive descriptors to potential climatic influences. 4. Overall, thermal regimes in streams we studied showed high frequency and low variability of cold temperatures during the cold-water period in winter and spring, and high frequency and high variability of warm temperatures during the warm-water period in summer and autumn. The cold and warm periods differed in the distribution of events with a higher frequency and longer duration of warm events in summer than cold events in winter. The cold period exhibited lower variability in the duration of events, but showed more variability in timing. 5. In conclusion, our results highlight the importance of a year-round perspective in identifying the most responsive characteristics or descriptors of thermal regimes in streams. The descriptors we provide herein can be applied across hydro-ecological regions to evaluate spatial and temporal patterns in thermal regimes. Evaluation of coherence and synchrony of different components of thermal regimes can facilitate identification of impacts of regional climate variability or local human or natural influences.

Office and ambulatory blood pressure control with a fixed-dose combination of candesartan and hydrochlorothiazide in previously uncontrolled hypertensive patients: results of CHILI CU Soon

PubMed Central

Mengden, Thomas; Hübner, Reinhold; Bramlage, Peter

2011-01-01

Background Fixed-dose combinations of candesartan 32 mg and hydrochlorothiazide (HCTZ) have been shown to be effective in clinical trials. Upon market entry we conducted a noninterventional study to document the safety and effectiveness of this fixed-dose combination in an unselected population in primary care and to compare blood pressure (BP) values obtained during office measurement (OBPM) with ambulatory blood pressure measurement (ABPM). Methods CHILI CU Soon was a prospective, noninterventional, noncontrolled, open-label, multicenter study with a follow-up of at least 10 weeks. High-risk patients aged ≥18 years with previously uncontrolled hypertension were started on candesartan 32 mg in a fixed-dose combination with either 12.5 mg or 25 mg HCTZ. OBPM and ABPM reduction and adverse events were documented. Results A total of 4131 patients (52.8% male) with a mean age of 63.0 ± 11.0 years were included. BP was 162.1 ± 14.8/94.7 ± 9.2 mmHg during office visits at baseline. After 10 weeks of candesartan 32 mg/12.5 mg or 25 mg HCTZ, mean BP had lowered to 131.7 ± 10.5/80.0 ± 6.6 mmHg (P < 0.0001 for both comparisons). BP reduction was comparable irrespective of prior or concomitant medication. In patients for whom physicians regarded an ABPM to be necessary (because of suspected noncontrol over 24 hours), ABP at baseline was 158.2/93.7 mmHg during the day and 141.8/85.2 mmHg during the night. At the last visit, BP had significantly reduced to 133.6/80.0 mmHg and 121.0/72.3 mmHg, respectively, resulting in 20.8% being normotensive over 24 hours (<130/80 mmHg). The correlation between OBPM and ABPM was good (r = 0.589 for systolic BP and r = 0.389 for diastolic BP during the day). Of those who were normotensive upon OBPM, 35.1% had high ABPM during the day, 49.3% were nondippers, and 3.4% were inverted dippers. Forty-nine adverse events (1.19%) were reported, of which seven (0.17%) were regarded as serious. Conclusion Candesartan 32 mg in a fixed-dose combination with either 12.5 mg or 25 mg HCTZ is safe and effective for further BP lowering irrespective of prior antihypertensive drug class not being able to control BP. PMID:22241950

ENSO's far reaching connection to Indian cold waves.

PubMed

Ratnam, J V; Behera, Swadhin K; Annamalai, H; Ratna, Satyaban B; Rajeevan, M; Yamagata, Toshio

2016-11-23

During boreal winters, cold waves over India are primarily due to transport of cold air from higher latitudes. However, the processes associated with these cold waves are not yet clearly understood. Here by diagnosing a suite of datasets, we explore the mechanisms leading to the development and maintenance of these cold waves. Two types of cold waves are identified based on observed minimum surface temperature and statistical analysis. The first type (TYPE1), also the dominant one, depicts colder than normal temperatures covering most parts of the country while the second type (TYPE2) is more regional, with significant cold temperatures only noticeable over northwest India. Quite interestingly the first (second) type is associated with La Niña (El Niño) like conditions, suggesting that both phases of ENSO provide a favorable background for the occurrence of cold waves over India. During TYPE1 cold wave events, a low-level cyclonic anomaly generated over the Indian region as an atmospheric response to the equatorial convective anomalies is seen advecting cold temperatures into India and maintaining the cold waves. In TYPE2 cold waves, a cyclonic anomaly generated over west India anomalously brings cold winds to northwest India causing cold waves only in those parts.

Cold Electrons as the Drivers of Parallel, Electrostatic Waves in Asymmetric Reconnection

NASA Astrophysics Data System (ADS)

Holmes, J.; Ergun, R.; Newman, D. L.; Wilder, F. D.; Schwartz, S. J.; Goodrich, K.; Eriksson, S.; Torbert, R. B.; Russell, C. T.; Lindqvist, P. A.; Giles, B. L.; Pollock, C. J.; Le Contel, O.; Strangeway, R. J.; Burch, J. L.

2016-12-01

The Magnetospheric MultiScale mission (MMS) has observed several instances of asymmetric reconnection at Earth's magnetopause, where plasma from the magnetosheath encounters that of the magnetosphere. On Earth's dayside, the magnetosphere is often made up of a two-component distribution of cold (<< 10 eV) and hot ( 1 keV) plasma, sometimes including the cold ion plume. Magnetosheath plasma is primarily warm ( 100 eV) post-shock solar wind. Where they meet, magnetopause reconnection alters the magnetic topology such that these two populations are left cohabiting a field line and rapidly mix. There have been several events observed by MMS where the Fast Plasma Instrument (FPI) clearly shows cold ions near the diffusion region impinging upon the warm magnetosheath population. In many of these, we also see patches of strong electrostatic waves parallel to the magnetic field - a smoking gun for rapid mixing via nonlinear processes. Cold ions alone are too slow to create the same waves; solving for roots of a simplified dispersion relation shows the electron population damps out the ion modes. From this, we infer the presence of cold electrons; in one notable case found by Wilder et al. 2016 (in review), they have been observed directly by FPI. Vlasov simulations of plasma mixing for a number of these events closely reproduce the observed electric field signatures. We conclude from numerical analysis and direct MMS observations that cold plasma mixing, including cold electrons, is the primary driver of parallel electrostatic waves observed near the electron diffusion region in asymmetric magnetic reconnection.

Effectiveness and cost-effectiveness of blood pressure screening in adolescents in the United States.

PubMed

Wang, Y Claire; Cheung, Angela M; Bibbins-Domingo, Kirsten; Prosser, Lisa A; Cook, Nancy R; Goldman, Lee; Gillman, Matthew W

2011-02-01

To compare the long-term effectiveness and cost-effectiveness of 3 approaches to managing elevated blood pressure (BP) in adolescents in the United States: no intervention, "screen-and-treat," and population-wide strategies to lower the entire BP distribution. We used a simulation model to combine several data sources to project the lifetime costs and cardiovascular outcomes for a cohort of 15-year-old U.S. adolescents under different BP approaches and conducted cost-effectiveness analysis. We obtained BP distributions from the National Health and Nutrition Examination Survey 1999-2004 and used childhood-to-adult longitudinal correlation analyses to simulate the tracking of BP. We then used the coronary heart disease policy model to estimate lifetime coronary heart disease events, costs, and quality-adjusted life years (QALY). Among screen-and-treat strategies, finding and treating the adolescents at highest risk (eg, left ventricular hypertrophy) was most cost-effective ($18000/QALY [boys] and $47000/QALY [girls]). However, all screen-and-treat strategies were dominated by population-wide strategies such as salt reduction (cost-saving [boys] and $650/QALY [girls]) and increasing physical education ($11000/QALY [boys] and $35000/QALY [girls]). Routine adolescents BP screening is moderately effective, but population-based BP interventions with broader reach could potentially be less costly and more effective for early cardiovascular disease prevention and should be implemented in parallel. Copyright © 2011 Mosby, Inc. All rights reserved.

CacyBP/SIP nuclear translocation regulates p27Kip1 stability in gastric cancer cells

PubMed Central

Niu, Ying-Lin; Li, Ya-Jun; Wang, Jing-Bo; Lu, Yuan-Yuan; Liu, Zhen-Xiong; Feng, Shan-Shan; Hu, Jian-Guo; Zhai, Hui-Hong

2016-01-01

AIM: To investigate the mechanism of calcyclin binding protein/Siah-1 interacting protein (CacyBP/SIP) nuclear translocation in promoting the proliferation of gastric cancer (GC) cells. METHODS: The effect of CacyBP/SIP nuclear translocation on cell cycle was investigated by cell cycle analysis. Western blot analysis was used to assess the change in expression of cell cycle regulatory proteins and proteasome-mediated degradation of p27Kip1. Co-immunoprecipitation (co-IP) analysis was performed to examine the binding of CacyBP/SIP with Skp1. A CacyBP/SIP truncation mutant which lacked the Skp1 binding site was constructed and fused to a fluorescent protein. Subsequently, the effect on Skp1 binding with the fusion protein was examined by co-IP, while localization of fluorescent fusion protein observed by confocal laser microscopy, and change in p27Kip1 protein expression assessed by Western blot analysis. RESULTS: CacyBP/SIP nuclear translocation induced by gastrin promoted progression of GC cells from G1 phase. However, while CacyBP/SIP nuclear translocation was inhibited using siRNA to suppress CacyBP/SIP expression, cell cycle was clearly inhibited. CacyBP/SIP nuclear translocation significantly decreased the level of cell cycle inhibitor p27Kip1, increased Cyclin E protein expression whereas the levels of Skp1, Skp2, and CDK2 were not affected. Upon inhibition of CacyBP/SIP nuclear translocation, there were no changes in protein levels of p27Kip1 and Cyclin E, while p27Kip1 decrease could be prevented by the proteasome inhibitor MG132. Moreover, CacyBP/SIP was found to bind to Skp1 by immunoprecipitation, an event that was abolished by mutant CacyBP/SIP, which also failed to stimulate p27Kip1 degradation, even though the mutant could still translocate into the nucleus. CONCLUSION: CacyBP/SIP nuclear translocation contributes to the proliferation of GC cells, and CacyBP/SIP exerts this effect, at least in part, by stimulating ubiquitin-mediated degradation of p27Kip1. PMID:27099442

Older Thinopyrum intermedium (Poaceae) plants exhibit superior photosynthetic tolerance to cold stress and greater increases in two photosynthetic enzymes under freezing stress compared with young plants

PubMed Central

Jaikumar, Nikhil S.; Snapp, Sieglinde S.; Sharkey, Thomas D.

2016-01-01

Effects of plant age on resource acquisition and stress tolerance processes is a largely unstudied subject in herbaceous perennials. In a field experiment, we compared rates of photosynthesis (A), ribulose-1,5-bisphosphate (RuBP) carboxylation capacity (V Cmax), maximum electron transport rate (J max), and triose phosphate utilization (TPU), as well as concentrations of Rubisco and sucrose-phosphate synthase (SPS) in 5-year-old and 2-year-old intermediate wheatgrass (Thinopyrum intermedium) under both optimal growing conditions and cold stress in early spring and autumn. This species is a relative of wheat undergoing domestication. An additional experiment compared photosynthetic rates in different cohorts at mid-season and under colder conditions. We hypothesized that photosynthetic capacity in older plants would be lower under favorable conditions but higher under cold stress. Our hypothesis was generally supported. Under cold stress, 5-year-old plants exhibited higher A, TPU, and temperature-adjusted V Cmax than younger plants, as well as 50% more SPS and 37% more Rubisco. In contrast, at mid-season, photosynthetic capacities in older plants were lower than in younger plants in one experiment, and similar in the other, independent of differences in water status. Both cohorts increased A, temperature-adjusted TPU and J max, [Rubisco], and [SPS] under cold stress, but changes were greater in older plants. Photosynthetic differences were largest at 1.2 ºC in very early spring, where older plants had 200% higher A and maintained up to 17% of their peak photosynthetic capacity. We find evidence of increased cold tolerance in older cohorts of wheatgrass, consistent with a growing body of research in woody perennials. PMID:27401911

Millennial-scale Asian summer monsoon variations in South China since the last deglaciation

NASA Astrophysics Data System (ADS)

Wang, Xisheng; Chu, Guoqiang; Sheng, Mei; Zhang, Shuqin; Li, Jinhua; Chen, Yun; Tang, Ling; Su, Youliang; Pei, Junling; Yang, Zhenyu

2016-10-01

Characterizing spatiotemporal variability of the Asian summer monsoon (ASM) is critical for full understanding of its behavior, dynamics, and future impacts. The present knowledge about ASM variations since the last glaciation in South China largely relies on several precisely-dated speleothem stable oxygen isotope (δ18 O) records. Although these speleothem δ18 O signals provide useful evidence for regional past environmental changes, their validity for denoting ASM intensity remains a great controversy. The Huguangyan Maar Lake (HML) provides one of the most complete archives of environmental and climatic changes in the tropical-subtropical South and East Asia since the last glaciation. Here we document a continuous centennial- to millennial-scale ASM record over the past 16 ky BP from the high-sedimentation-rate HML sediments. In contrast with the low-amplitude variations of Chinese speleothem-derived δ18 O signals and the Chinese loess-based monsoon precipitation proxy indexes, our multi-proxy records reveal a pattern of high-amplitude regional climatic fluctuations, including fine-scale oscillations during the Bølling-Allerød warming, the 8.2 ka cooling event, and an abrupt climate shift from 6.5-5.9 ka. The existence of Bond-like cold/dry events indicates a distinct influence of the North Atlantic circulation on low-latitude monsoon changes. The broad comparability between the HML paleo-proxies, Chinese speleothem δ18 O records, and the northern hemisphere summer insolation throughout the Holocene, suggests that solar insolation exerts a profound influence on ASM changes. These findings reinforce a model of combined insolation and glacial forcing of the ASM.

Late Pliocene/Early Pleistocene environments inferred from the Lake El'gygytgyn pollen record

NASA Astrophysics Data System (ADS)

Andreev, Andrei; Wennrich, Volker; Tarasov, Pavel; Raschke (Morozova), Elena; Brigham-Grette, Julie; Nowaczyk, Norbert; Melles, Martin

2014-05-01

The Arctic is known to play a crucial role within the global climate system. The mid-Pliocene (3-3.5 Ma) is considered to be the most probable scenario of the future climate changes. However, reliable climate projections are hampered by the complexity of the underlying natural variability and feedback mechanisms. An important prerequisite for the validation and improvement of the future projections is a better understanding of the long-term environmental history of the Arctic. Unfortunately, formation of continuous paleoenvironmental records in the Arctic was widely restricted due to repeated glaciations. Continuous sequences that penetrate the entire Quaternary and further into the Pliocene are highly desired and would enable to validate the temperature rise during the mid-Pliocene that was proposed by former studies. Such a record has now become available from Lake El'gygytgyn (67º30'N, 172º05E') located in a meteorite impact crater in north-eastern Siberia. The impact nearly 3.6 Ma ago formed an 18 km wide hole in the ground that then filled with water. The retrieved lake sediments have trapped pollen from a several thousand square-kilometer source area providing reliable insights into regional and over-regional millennial-scale vegetation and climate changes of the Arctic since the Pliocene. The ''El'gygytgyn Drilling Project" of ICDP has completed three holes in the center of the lake, penetrating about 318 m thick lake sediments and about 200 m of the impact rocks below. Because of its unusual origin and high-latitude setting in western Beringia, scientific drilling at Lake El'gygytgyn offered unique opportunities for paleoclimate research, allowing time-continuous climatic and environmental reconstructions back into the Pliocene. Late Pliocene and Early Pleistocene pollen assemblages can be subdivided into 55 pollen zones, which reflect the main environmental fluctuations in the region 3.55-2.15 Ma BP. Pollen-based climate reconstructions show that conditions in the study area were the warmest about 3.55-3.4 Ma BP when spruce-pine-fir-hemlock-larch-Pseudotsuga forests dominated in nowadays tundra area. After ca 3.4 Ma BP dark coniferous taxa gradually disappeared from the vegetation. Very pronounced environmental changes are revealed about ca 3.35-3.275 Ma BP when treeless tundra and steppe habitats dominated. Treeless and shrubby environments are also indicative after ca 2.6 Ma. Dry and cold climate conditions were similar to those during the Late Pleistocene. The Early Pleistocene sediments contain pollen assemblages reflecting alternation of treeless intervals with cold and dry climate and warmer intervals when larch forests with stone pines, shrub alders and birches were also common in the region. Very dry environments are revealed after ca 2.175 Ma BP. High amounts of green algae colonies (Botryococcus) in the studied sediments point to shallow-water conditions ca 2.55, 2.45, and ca 2.175 Ma BP. Thus, pollen studies show that sediments accumulated in Lake El'gygytgyn are an excellent archive of environmental changes since 3.55 Myr BP. The record well reflects main regional paleoenvironmental fluctuations. The further high-resolution palynological study of the core will reveal climate fluctuations inside the main glacial/interglacial intervals and will give the first continuous and detailed scheme of environmental changes for a whole Arctic.

SvABA: genome-wide detection of structural variants and indels by local assembly.

PubMed

Wala, Jeremiah A; Bandopadhayay, Pratiti; Greenwald, Noah F; O'Rourke, Ryan; Sharpe, Ted; Stewart, Chip; Schumacher, Steve; Li, Yilong; Weischenfeldt, Joachim; Yao, Xiaotong; Nusbaum, Chad; Campbell, Peter; Getz, Gad; Meyerson, Matthew; Zhang, Cheng-Zhong; Imielinski, Marcin; Beroukhim, Rameen

2018-04-01

Structural variants (SVs), including small insertion and deletion variants (indels), are challenging to detect through standard alignment-based variant calling methods. Sequence assembly offers a powerful approach to identifying SVs, but is difficult to apply at scale genome-wide for SV detection due to its computational complexity and the difficulty of extracting SVs from assembly contigs. We describe SvABA, an efficient and accurate method for detecting SVs from short-read sequencing data using genome-wide local assembly with low memory and computing requirements. We evaluated SvABA's performance on the NA12878 human genome and in simulated and real cancer genomes. SvABA demonstrates superior sensitivity and specificity across a large spectrum of SVs and substantially improves detection performance for variants in the 20-300 bp range, compared with existing methods. SvABA also identifies complex somatic rearrangements with chains of short (<1000 bp) templated-sequence insertions copied from distant genomic regions. We applied SvABA to 344 cancer genomes from 11 cancer types and found that short templated-sequence insertions occur in ∼4% of all somatic rearrangements. Finally, we demonstrate that SvABA can identify sites of viral integration and cancer driver alterations containing medium-sized (50-300 bp) SVs. © 2018 Wala et al.; Published by Cold Spring Harbor Laboratory Press.

Cold Episodes, Their Precursors and Teleconnections in the Central Peruvian Andes (1958-2009)

NASA Astrophysics Data System (ADS)

Sulca, J. C.; Vuille, M. F.; Trasmonte, G.; Silva, Y.; Takahashi, K.

2014-12-01

The Mantaro valley (MV) is located in the central Peruvian Andes. Occasionally, cold episodes are observed during the austral summer (January-March), which strongly damage crops. However, little is known about the causes and impacts of such cold episodes in the MV. The main goal of this study is thus to characterize cold episodes in the MV and assess their large-scale circulation and teleconnections over South America (SA) during austral summer. To identify cold events in the MV daily minimum temperature for the period 1958-2009 from Huayao station, located within the MV was used. We defined a cold episode as the period when daily minimum temperature drops below the 10-percentile for at least one day. Several gridded reanalysis and satellite products were used to characterize the large-scale circulation, cloud cover and rainfall over SA associated with these events for same period. Cold episodes in the MV are associated with positive OLR anomalies, which extend over much of the central Andes, indicating reduced convective cloud cover during these extremes, but also affirm the large-scale nature of these events. At the same time, northeastern Brazil (NEB) registers negative OLR anomalies, strong convective activity and enhanced cloud cover because displacement of the South Atlantic Convergence Zone (SACZ) toward the northeast of its climatologic position. Further, it is associated with a weakening of the Bolivian High - Nordeste Low (BH-NL) system at upper levels, but also influenced by a low-level migratory high-pressure center develops at 30°S, 50°W; propagating from mid- to low latitudes as part of an extratropical Rossby wave train. In conclusion, cold episodes in the MV appear to be caused by radiative cooling associated with reduced cloudiness, rather than cold air advection. The reduced cloud cover in turn results from a robust large-scale pattern of westerly wind anomalies over central Peruvian Andes, inhibiting moisture influx, convective activity and hence cloud formation. At the same time NEB registers strong convective activity and enhanced cloud cover. This dipole is caused by a weakening of BH-NL system at upper levels, which is associated with a low-level migratory high-pressure center, propagating from mid- to low latitudes as part of an extratropical Rossby wave train.

Ancient charcoal as a natural archive for paleofire regime and vegetation change in the Mayumbe, Democratic Republic of the Congo

NASA Astrophysics Data System (ADS)

Hubau, Wannes; Van den Bulcke, Jan; Kitin, Peter; Mees, Florias; Baert, Geert; Verschuren, Dirk; Nsenga, Laurent; Van Acker, Joris; Beeckman, Hans

2013-09-01

Charcoal was sampled in four soil profiles at the Mayumbe forest boundary (DRC). Five fire events were recorded and 44 charcoal types were identified. One stratified profile yielded charcoal assemblages around 530 cal yr BP and > 43.5 cal ka BP in age. The oldest assemblage precedes the period of recorded anthropogenic burning, illustrating occasional long-term absence of fire but also natural wildfire occurrences within tropical rainforest. No other charcoal assemblages older than 2500 cal yr BP were recorded, perhaps due to bioturbation and colluvial reworking. The recorded paleofires were possibly associated with short-lived climate anomalies. Progressively dry climatic conditions since ca. 4000 cal yr BP onward did not promote paleofire occurrence until increasing seasonality affected vegetation at the end of the third millennium BP, as illustrated by a fire occurring in mature rainforest that persisted until around 2050 cal yr BP. During a drought episode coinciding with the 'Medieval Climate Anomaly', mature rainforest was locally replaced by woodland savanna. Charcoal remains from pioneer forest indicate that fire hampered forest regeneration after climatic drought episodes. The presence of pottery shards and oil-palm endocarps associated with two relatively recent paleofires suggests that the effects of climate variability were amplified by human activities.

Electrophysiological evidence of functional integration between the language and motor systems in the brain: a study of the speech Bereitschaftspotential.

PubMed

McArdle, J J; Mari, Z; Pursley, R H; Schulz, G M; Braun, A R

2009-02-01

We investigated whether the Bereitschaftspotential (BP), an event related potential believed to reflect motor planning, would be modulated by language-related parameters prior to speech. We anticipated that articulatory complexity would produce effects on the BP distribution similar to those demonstrated for complex limb movements. We also hypothesized that lexical semantic operations would independently impact the BP. Eighteen participants performed 3 speech tasks designed to differentiate lexical semantic and articulatory contributions to the BP. EEG epochs were time-locked to the earliest source of speech movement per trial. Lip movements were assessed using EMG recordings. Doppler imaging was used to determine the onset of tongue movement during speech, providing a means of identification and elimination of potential artifact. Compared to simple repetition, complex articulations produced an anterior shift in the maximum midline BP. Tasks requiring lexical search and selection augmented these effects and independently elicited a left lateralized asymmetry in the frontal distribution. The findings indicate that the BP is significantly modulated by linguistic processing, suggesting that the premotor system might play a role in lexical access. These novel findings support the notion that the motor systems may play a significant role in the formulation of language.

Drug-induced bullous pemphigoid in diabetes mellitus patients receiving dipeptidyl peptidase-IV inhibitors plus metformin.

PubMed

Skandalis, K; Spirova, M; Gaitanis, G; Tsartsarakis, A; Bassukas, I D

2012-02-01

Preclinical data and reports of adverse skin reactions in patients treated with dipeptidyl peptidase-IV inhibitors (gliptins) have increased awareness towards skin-targeting side-effects of these anti-hyperglycaemic drugs. Bullous pemphigoid (BP), sometimes drug-induced, is the most commonly acquired autoimmune blistering dermatosis in western countries, typically a disease of the elderly people with significant morbidity and excess mortality. To report the development of BP in five diabetics under gliptin (4 vildagliptin, 1 sitagliptin) plus metformin in fixed-dose drug combinations. From March to August 2010 six out of nine newly diagnosed BP patients in our Department were type 2 diabetics. Five of them were on gliptin plus metformin (three different trade preparations) for 2-13 months prior to BP onset. In all cases BP was controlled after withdrawal of the suspected medication and relatively mild therapeutic interventions. In two cases the eliciting role of the preceding treatment is supported by evidence at the level 'probable/likely' according to the WHO-UMC algorithm. This is the first report of drug-induced BP as a group adverse event of the gliptins plus metformin combination therapy for glycaemia control in type 2 diabetes mellitus patients. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

Holocene vegetation and climate change recorded in alpine bog sediments from the Borreguiles de la Virgen, Sierra Nevada, southern Spain

NASA Astrophysics Data System (ADS)

Jiménez-Moreno, Gonzalo; Anderson, R. Scott

2012-01-01

High-resolution pollen and magnetic susceptibility (MS) analyses have been carried out on a sediment core taken from a high-elevation alpine bog area located in Sierra Nevada, southern Spain. The earliest part of the record, from 8200 to about 7000 cal yr BP, is characterized by the highest abundance of arboreal pollen and Pediastrum, indicating the warmest and wettest conditions in the area at that time. The pollen record shows a progressive aridification since 7000 cal yr BP that occurred in two steps, first shown by a decrease in Pinus, replaced by Poaceae from 7000 to 4600 cal yr BP and then by Cyperaceae, Artemisia and Amaranthaceae from 4600 to 1200 cal yr BP. Pediastrum also decreased progressively and totally disappeared at ca. 3000 yr ago. The progressive aridification is punctuated by periodically enhanced drought at ca. 6500, 5200 and 4000 cal yr BP that coincide in timing and duration with well-known dry events in the Mediterranean and other areas. Since 1200 cal yr BP, several changes are observed in the vegetation that probably indicate the high-impact of humans in the Sierra Nevada, with pasturing leading to nutrient enrichment and eutrophication of the bog, Pinus reforestation and Olea cultivation at lower elevations.

A closer look at the relationships between meridional mass circulation pulses in the stratosphere and cold air outbreak patterns in northern hemispheric winter

NASA Astrophysics Data System (ADS)

Yu, Yueyue; Cai, Ming; Ren, Rongcai; Rao, Jian

2018-01-01

The relationship between continental-scale cold air outbreaks (CAOs) in the mid-latitudes and pulse signals in the stratospheric mass circulation in Northern Hemisphere winter (December-February) is investigated using ERA-Interim data for the 32 winters from 1979 to 2011. Pulse signals in the stratospheric mass circulation include "PULSE_TOT", "PULSE_W1", and "PULSE_W2" events, defined as a period of stronger meridional mass transport into the polar stratosphere by total flow, wavenumber-1, and wavenumber-2, respectively. Each type of PULSE event occurs on average 4-6 times per winter. A robust relationship is found between two dominant patterns of winter CAOs and PULSE_W1 and PULSE_W2 events. Cold temperature anomalies tend to occur over Eurasia with the other continent anomalously warm during the 2 weeks before the peak dates of PULSE_W1 events, while the opposite temperature anomaly pattern can be found after the peak dates; and during the 1-2 weeks centered on the peak dates of PULSE_W2 events, a higher probability of occurrence of CAOs is found over both continents. These relationships become more robust for PULSE_W1 and PULSE_W2 events of larger peak intensity. PULSE_TOT events are classified into five types, which have a distinct coupling relationship with PULSE_W1 and PULSE_W2 events. The specific pattern of CAOs associated with each type of PULSE_TOT event is found to be a combination of the CAO patterns associated with PULSE_W1 and PULSE_W2 events. The percentage of PULSE_TOT events belonging to the types that are dominated by PULSE_W2 events increases with the peak intensity of PULSE_TOT events. Accordingly, the related CAO pattern is close to that associated with PULSE_W1 for PULSE_TOT events with small-to-medium intensity, but tends to resemble that associated with PULSE_W2 events as the peak intensity of PULSE_TOT events increases.

AMS 14C and 230Th/U dating on stalagmites from North Altai Mountain, Siberia, Russia

NASA Astrophysics Data System (ADS)

Li, H. C.; Yin, J. J.; Blyakharchuk, T.; Shen, C. C.

2017-12-01

Three stalagmites, two from Lunnaya Cave (LUN-1 and LUN-2, 52º40.729'N, 88º43.854' E, 481 m a.s.l.), one from Nadezhda Cave (HOP-1, 52º38.872'N, 88º39.194'E, 550 m a.s.l.) located along Mrassy River in the northern Altai Mountains, Siberia, Russia were collected in the summer of 2016 for paleoclimate reconstruction. HOP-1 is a 21-cm long stalagmite which contains very low U content (238U = 70 ppb) and relatively high Th content (232Th = 2 9.3 ppb), resulting in unsuccessful 230Th/U dating (-262 ± 284 yr BP in the top and -19,935 ± 22,246 yr BP). Thirty one AMS 14C dates from 27 horizons of the stalagmite provide a detailed chronology, showing that the stalagmite grew from 6,350 ± 45 yr BP to 490 ± 10 Calib. yr BP. Both LUN-1 and LUN-2 are about 20-cm long. The growth feature of LUN-2 is similar to that of HOP-1 with continuous growth, clear bands of depositional cycles in white non-transparent calcite, whereas LUN-1 has light yellow transparent calcite in the center part with multiple growth hiatuses. The 230Th/U dates show that LUN-1 from 2725 ± 775 yr BP at 193 mm depth to 823 ± 28 yr BP at 12 mm depth with very fast growth rate during 900 1500 yr BP. The AMS 14C dates of LUN-1 provide similar growth pattern with very fast growth between the first hiatus at 12 mm depth and the second hiatus at 155 cm depth. Six 14C dates from this fast growth period are all around 1500 Calib. yr BP without a correct age sequence. Two 14C dates from the top 12 mm exhibit "nuclear bomb signal" (percentage of modern carbon >100%). Similar ages of AMS 14C and 230Th/U dating results in the lower part indicate that dead carbon influence in radiocarbon ages are negligible. 230Th/U dating is not successful for LUN-2. The preliminary AMS 14C dating on LUN-2 shows that the stalagmite continuously deposited from 13335 ± 150 Calib. yr BP. All three stalagmites do not have growth deposition during the Little Ice Age due to cold and dry climates. Further work on stable isotope analyses will provide us high-resolution paleoclimate changes since the deglaciation in the study area.

76 FR 6118 - Endangered Species; File No. 14726

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-03

... potential Mississippi Canyon 252 oil exposure of pelagic sea turtles associated with floating Sargassum as part of the post-spill Natural Resources Damage Assessment of the BP Deepwater Horizon event. The...

Low physical activity is a determinant for elevated blood pressure in high cardiovascular risk obstructive sleep apnea.

PubMed

Mendelson, Monique; Tamisier, Renaud; Laplaud, David; Dias-Domingos, Sonia; Baguet, Jean-Philippe; Moreau, Laurent; Koltes, Christian; Chavez, Léonidas; de Lamberterie, Gilles; Herengt, Frédéric; Levy, Patrick; Flore, Patrice; Pépin, Jean-Louis

2014-08-01

Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity, including hypertension. Beyond the severity of nocturnal hypoxia, other factors such as metabolic abnormalities but also sedentary behaviors and insufficient physical activity may contribute to elevated blood pressure (BP). To clarify the respective role of these factors as determinants of BP in OSA patients, we examined the relationship between BP and anthropometrics, severity of sleep apnea, and objectively measured physical activity and sedentary behaviors. Ninety-five adults presenting with OSA (apnea-hypopnea index > 10 events/h) and high cardiovascular risk (63.3 ± 8.8 y; body mass index: 29.9 ± 4.9 kg/m(2); apnea-hypopnea index: 41.3 ± 17.5/h; cardiovascular risk score: 13.5 ± 3.7%) were included. Physical activity and sedentary behaviors were objectively assessed by actigraphy, and self-measured home BP monitoring was measured. Logistic regression models adjusted for sex, age, and body mass index were built to identify the predictors of self-measured morning and evening BP. Physical activity was significantly related to obesity but not to the severity of sleep apnea or sleepiness. Sedentary behaviors were associated with self-measured morning and evening systolic BP (r = 0.32, P = .002; r = 0.29, P = .004). Steps per day were inversely associated with evening BP (r = -0.27, P = .01). Univariate analysis identified steps/d and time spent in vigorous physical activity as determinants for evening self-measured BP. In multivariate analysis, only steps/d were identified as a significant determinant of evening BP. Physical activity is the major determinant for evening BP in adults with OSA presenting high cardiovascular risk. Our results emphasize the need for lifestyle counseling programs in combination with CPAP to encourage regular physical activity in OSA subjects to obtain better BP control. (ClinicalTrials.gov registration NCT01226641.)

Early-Mid Holocene climatic variations in Tasmania, Australia: multi-proxy records in a stalagmite from Lynds Cave

NASA Astrophysics Data System (ADS)

Xia, Qikai; Zhao, Jian-xin; Collerson, K. D.

2001-12-01

Mass spectrometric uranium-series dating and C-O isotopic analysis of a stalagmite from Lynds Cave, northern Tasmania, Australia provide a high-resolution record of regional climate change between 5100 and 9200 yr before present (BP). Combined δ18O, δ13C, growth rate, initial 234U/238U and physical property (color, transparency and porosity) records allow recognition of seven climatic stages: Stage I (>9080 yr BP) - a relatively dry period at the beginning of stalagmite growth evidenced by elevated 234U/238U; Stage II (9080-8600 yr BP) - a period of unstable climate characterized by high-frequency variability in temperature and bio-productivity; Stage III (8600-8000 yr BP) - a period of stable and moderate precipitation and stable and high bio-productivity, with a continuously rising temperature; Stage IV (8000-7400 yr BP) - the warmest period with high evaporation and low effective precipitation (rainfall less evaporation); Stage V (7400-7000 yr BP) - the wettest period with highest stalagmite growth and enhanced but unstable bio-productivity; Stage VI (7000-6600 yr BP) - a period with a significantly reduced precipitation and bio-productivity without noticeable change in temperature; Stage VII (6600-5100 yr BP) - a period of lowest temperature and precipitation marking a significant climatic deterioration. Overall, the records suggest that the warmest climate occurred between 8000 and 7400 yr BP, followed by a wettest period between 7400 and 7000 yr BP. These are broadly correlated with the so-called 'Mid Holocene optimum' previously proposed using pollen and lake level records. However, the timing and resolution of the speleothem record from Lynds Cave are significantly higher than in both the pollen and lake level records. This allows us to correlate the abrupt change in physical property, δ18O, δ13C, growth rate, and initial 234U/238U of the stalagmite at ˜8000 yr BP with a global climatic event at Early-Mid Holocene transition.

Lacustrine records of Holocene climate and environmental change from the Lofoten Islands, Norway

NASA Astrophysics Data System (ADS)

Balascio, Nicholas L.

Lakes sediments from the Lofoten Islands, Norway, can be used to generate well resolved records of past climate and environmental change. This dissertation presents three lacustrine paleoenvironmental reconstructions that show evidence for Holocene climate changes associated with North Atlantic climate dynamics and relative sea-level variations driven by glacio-isostatic adjustment. This study also uses distal tephra deposits (cryptotephra) from Icelandic volcanic eruptions to improve the chronologies of these reconstructions and explores new approaches to crypto-tephrochronology. Past and present conditions at Vikjordvatnet, Fiskebolvatnet, and Heimerdalsvatnet were studied during four field seasons conducted from 2007--2010. Initially, each lake was characterized by measuring water column chemistry, logging annual temperature fluctuations, and conducting bathymetric and seismic surveys. Sediment cores were then collected and analyzed using multiple techniques, including: sediment density, magnetic susceptibility, loss-on-ignition, total carbon and nitrogen, delta13C and delta 15N of organic matter, and elemental compositions acquired by scanning X-ray fluorescence. Chronologies were established using radiocarbon dating and tephrochronology. A 13.8 cal ka BP record from Vikjordvatnet provides evidence for glacial activity during the Younger Dryas cold interval and exhibits trends in Ti, Fe, and organic content during the Holocene that correlate with regional millennial-scale climate trends and provide evidence for more rapid events. A 9.7 cal ka BP record from Fiskebolvatnet shows a strong signal of sediment inwashing likely driven by local geomorphic conditions, although there is evidence that increased inwashing at the onset of the Neoglacial could have been associated with increased precipitation. Heimerdalsvatnet provides a record of relative sea-level change. A 7.8 cal ka BP sedimentary record reflects changes in salinity and water column conditions as the lake was isolated and defines sea-level regression following the Tapes transgression. Cryptotephra horizons were identified in sediments of Heimerdalsvatnet, Vikjordvatnet, and Sverigedalsvatn. They were also found in a Viking-age boathouse excavated along the shore of Inner Borgpollen. These include the GA4-85, BIP-24a, SILK-N2, Askja, 860 Layer B, Hekla 1158, Hekla 1104, Vedde Ash, and Saksunarvatn tephra. This research project also explored the use of scanning XRF to locate cryptotephra in lacustrine sediments and presents experimental results of XRF scans of tephra-spiked synthetic sediment cores.

Ambulatory blood pressure and cardiovascular events in chronic kidney disease

PubMed Central

Agarwal, Rajiv

2007-01-01

Purpose of review Hypertension is an important risk factor for adverse cardiovascular and renal outcomes particularly in patients with chronic kidney disease. This review compares blood pressure measurements obtained in the clinic with those obtained outside the clinic to predict cardiovascular and renal injury and outcomes. Recent findings Data are accumulating that suggest that ambulatory blood pressure monitoring is a superior prognostic marker compared to blood pressures obtained in the clinic. Use of ambulatory blood pressure monitoring can detect white coat hypertension and masked hypertension which results in less misclassification of blood pressures. Ambulatory blood pressure monitoring is a marker of cardiovascular end points in CKD. Non dipping is associated with proteinuria and lower GFR. Although non-dipping is associated with more ESRD and cardiovascular events, adjustment for other risk factors removes the prognostic significance of non-dipping. For patients with CKD, not on dialysis, 24 hour ambulatory BP of <125/75 mm Hg, daytime ambulatory of <130/85 mm Hg and nighttime ambulatory BP of <110/70 mm Hg appear to be reasonable goal BP targets. In the management of hypertension in patients with CKD, control of hypertension is important. Ambulatory BP monitoring may be useful to assign more aggressive treatment to patients with masked hypertension and withdraw antihypertensive therapy in patients with white-coat hypertension. Summary Ambulatory blood pressure monitoring can refine cardiovascular and renal risk assessment in all stages of chronic kidney disease. The independent prognostic role of non-dipping is unclear. PMID:17868791

CBL, CBLB, TET2, ASXL1, and IDH1/2 mutations and additional chromosomal aberrations constitute molecular events in chronic myelogenous leukemia

PubMed Central

Makishima, Hideki; Jankowska, Anna M.; McDevitt, Michael A.; O'Keefe, Christine; Dujardin, Simon; Cazzolli, Heather; Przychodzen, Bartlomiej; Prince, Courtney; Nicoll, John; Siddaiah, Harish; Shaik, Mohammed; Szpurka, Hadrian; Hsi, Eric; Advani, Anjali; Paquette, Ronald

2011-01-01

Progression of chronic myelogenous leukemia (CML) to accelerated (AP) and blast phase (BP) is because of secondary molecular events, as well as additional cytogenetic abnormalities. On the basis of the detection of JAK2, CBL, CBLB, TET2, ASXL1, and IDH1/2 mutations in myelodysplastic/myeloproliferative neoplasms, we hypothesized that they may also contribute to progression in CML. We screened these genes for mutations in 54 cases with CML (14 with chronic phase, 14 with AP, 20 with myeloid, and 6 with nonmyeloid BP). We identified 1 CBLB and 2 TET2 mutations in AP, and 1 CBL, 1 CBLB, 4 TET2, 2 ASXL1, and 2 IDH family mutations in myeloid BP. However, none of these mutations were found in chronic phase. No cases with JAK2V617F mutations were found. In 2 cases, TET2 mutations were found concomitant with CBLB mutations. By single nucleotide polymorphism arrays, uniparental disomy on chromosome 5q, 8q, 11p, and 17p was found in AP and BP but not involving 4q24 (TET2) or 11q23 (CBL). Microdeletions on chromosomes 17q11.2 and 21q22.12 involved tumor associated genes NF1 and RUNX1, respectively. Our results indicate that CBL family, TET2, ASXL1, and IDH family mutations and additional cryptic karyotypic abnormalities can occur in advanced phase CML. PMID:21346257

Age of the Mono Lake excursion and associated tephra

USGS Publications Warehouse

Benson, L.; Liddicoat, J.; Smoot, J.; Sarna-Wojcicki, A.; Negrini, R.; Lund, S.

2003-01-01

The Mono Lake excursion (MLE) is an important time marker that has been found in lake and marine sediments across much of the Northern Hemisphere. Dating of this event at its type locality, the Mono Basin of California, has yielded controversial results with the most recent effort concluding that the MLE may actually be the Laschamp excursion (Earth Planet. Sci. Lett. 197 (2002) 151). We show that a volcanic tephra (Ash #15) that occurs near the midpoint of the MLE has a date (not corrected for reservoir effect) of 28,620 ?? 300 14C yr BP (??? 32,400 GISP2 yr BP) in the Pyramid Lake Basin of Nevada. Given the location of Ash #15 and the duration of the MLE in the Mono Basin, the event occurred between 31,500 and 33,300 GISP2 yr BP, an age range consistent with the position and age of the uppermost of two paleointensity minima in the NAPIS-75 stack that has been associated with the MLE (Philos. Trans. R. Soc. London Ser. A 358 (2000) 1009). The lower paleointensity minimum in the NAPIS-75 stack is considered to be the Laschamp excursion (Philos. Trans. R. Soc. London Ser. A 358 (2000) 1009).