Environmental consequences of rapid urbanization in zhejiang province, East china.

PubMed

Yang, Xuchao; Yue, Wenze; Xu, Honghui; Wu, Jingsheng; He, Yue

2014-07-11

Since reforms carried out in the late 1970s, China has experienced unprecedented rates of urban growth. Remote sensing data and surface observational data are used to investigate the urbanization process and related environmental consequences, focusing on extreme heat events and air pollution, in Zhejiang Province (ZJP, East China). Examination of satellite-measured nighttime light data indicates rapid urbanization in ZJP during the past decade, initially forming three urban clusters. With rapid urban sprawl, a significant Urban Heat Island (UHI) effect has emerged. During extreme heat events in summer, the UHI effect significantly exacerbates nocturnal heat stress in highly urbanized areas. Taking a long-term view, urbanization also causes additional hot days and hot degree days in urban areas. Urbanization also imposes a heavy burden on local and regional air quality in ZJP. Degraded visibility and an increase in haze days are observed at most meteorological stations, especially in the three urban clusters. The results show that urbanization has led to serious environmental problems in ZJP, not only on the city scale, but also on the regional scale. Maintaining a balance between the continuing process of urbanization and environmental sustainability is a major issue facing the local government.

Continuous Cultivation for Apparent Optimization of Defined Media for Cellulomonas sp. and Bacillus cereus

PubMed Central

Summers, R. J.; Boudreaux, D. P.; Srinivasan, V. R.

1979-01-01

Steady-state continuous culture was used to optimize lean chemically defined media for a Cellulomonas sp. and Bacillus cereus strain T. Both organisms were extremely sensitive to variations in trace-metal concentrations. However, medium optimization by this technique proved rapid, and multifactor screening was easily conducted by using a minimum of instrumentation. The optimized media supported critical dilution rates of 0.571 and 0.467 h−1 for Cellulomonas and Bacillus, respectively. These values approximated maximum growth rate values observed in batch culture. PMID:16345417

A New Apparatus to Evaluate Lubricants for Space Applications: The Spiral Orbit Tribometer (SOT)

NASA Technical Reports Server (NTRS)

Jones, William R., Jr.; Pepper, Stephen V.; Jansen, Mark J.; Nguyen, QuynhGiao N.; Kingsbury, Edward P.; Loewenthal, Stuart H.; Predmore, Roamer E.

2000-01-01

Lubricants used in space mechanisms must be thoroughly tested prior to their selection for critical applications. Traditionally, two types of tests have been used: accelerated and full-scale. Accelerated tests are rapid, economical, and provide useful information for gross screening of candidate lubricants. Although full-scale tests are more believable, because they mimic actual spacecraft conditions, they are expensive and time consuming. The spiral orbit tribometer compromises between the two extremes. It rapidly determines the rate of tribochemically induced lubricant consumption, which leads to finite test times, under realistic rolling/pivoting conditions that occur in angular contact bearings.

Extreme rainfall, vulnerability and risk: a continental-scale assessment for South America.

PubMed

Vörösmarty, Charles J; Bravo de Guenni, Lelys; Wollheim, Wilfred M; Pellerin, Brian; Bjerklie, David; Cardoso, Manoel; D'Almeida, Cassiano; Green, Pamela; Colon, Lilybeth

2013-11-13

Extreme weather continues to preoccupy society as a formidable public safety concern bearing huge economic costs. While attention has focused on global climate change and how it could intensify key elements of the water cycle such as precipitation and river discharge, it is the conjunction of geophysical and socioeconomic forces that shapes human sensitivity and risks to weather extremes. We demonstrate here the use of high-resolution geophysical and population datasets together with documentary reports of rainfall-induced damage across South America over a multi-decadal, retrospective time domain (1960-2000). We define and map extreme precipitation hazard, exposure, affectedpopulations, vulnerability and risk, and use these variables to analyse the impact of floods as a water security issue. Geospatial experiments uncover major sources of risk from natural climate variability and population growth, with change in climate extremes bearing a minor role. While rural populations display greatest relative sensitivity to extreme rainfall, urban settings show the highest rates of increasing risk. In the coming decades, rapid urbanization will make South American cities the focal point of future climate threats but also an opportunity for reducing vulnerability, protecting lives and sustaining economic development through both traditional and ecosystem-based disaster risk management systems.

Funnel-shaped surface depressions - Indicator or accelerant of rapid glacier disintegration? A case study in the Tyrolean Alps

NASA Astrophysics Data System (ADS)

Stocker-Waldhuber, Martin; Fischer, Andrea; Keller, Lorenz; Morche, David; Kuhn, Michael

2017-06-01

Alpine glaciers have been retreating at extreme and historically unprecedented rates. While the general course of regional retreat rates reflects long-term climatic change, individual extreme events are closely related to the geomorphological settings and processes of the specific glacier. Nevertheless, these extreme events also influence the regional means and might be an important feedback mechanism accelerating the response of glaciers to climate change. In 2009, during the recent disintegration of the terminus of Gepatschferner (46°52‧30″N, 10°45‧25″E), a shallow circular depression appeared at the glacier tongue with a decrease of surface ice flow velocity to almost nil. In 2015 the area was ice-free. During a heavy precipitation event in August 2012, a subglacial sediment layer of > 10 m was flushed out, which accelerated the subsidence of the ice surface. The development of this 15 to 30 m deep depression was monitored with a combination of methods in high detail, including direct ablation measurements and a time series of seven high-resolution airborne laser DEMs, plus recordings of ice flow velocity and surface elevation with DGPS. The thickness of ice and sediment layers was measured with vibroseismic soundings in 2012 and 2013. Similar developments were observed at three other glaciers with extreme retreat rates. Our investigation suggests that this mechanism has a major impact on and can be read as an indicator of a nonlinear increased response of glaciers to climate change.

Extreme hyperglycemia with ketoacidosis and hyperkalemia in a patient on chronic hemodialysis.

PubMed

Gupta, Arvin; Rohrscheib, Mark; Tzamaloukas, Antonios H

2008-10-01

A patient on hemodialysis for end-stage renal disease secondary to diabetic nephropathy was admitted in a coma with Kussmaul breathing and hypertension (232/124 mmHg). She had extreme hyperglycemia (1884 mg/dL), acidosis (total CO(2) 4 mmol/L), hyperkalemia (7.2 mmol/L) with electrocardiographic abnormalities, and hypertonicity (330.7 mOsm/kg). Initial treatment with insulin drip resulted in a decrease in serum potassium to 5.3 mmol/L, but no significant change in mental status or other laboratory parameters. Hemodialysis of 1.75 hours resulted in rapid decline in serum glucose and tonicity and rapid improvement of the acidosis, but no change in mental status, which began to improve slowly after the hemodialysis was stopped, but with ongoing treatment with continuous insulin infusion. The rate of decline in tonicity during hemodialysis (14.5 mOsm/kg/h) was high, raising concerns about neurological complications. In this case, extreme hyperglycemia with ketoacidosis, hyperkalemia, and coma developing in a hemodialysis patient responded to insulin infusion. Monitoring of the clinical status and the pertinent laboratory values is required to assess the need for other therapeutic measures including volume and potassium replacement and emergency dialysis. The indications for and risks of emergency dialysis in this setting are not clearly defined.

Breaking the Habit - The peculiar 2016 eruption of the remarkable recurrent nova M31N 2008-12a

NASA Astrophysics Data System (ADS)

Henze, Martin; M31N 2008-12a Monitoring Collaboration

2018-01-01

Since its discovery in 2008, the Andromeda galaxy nova M31N 2008-12a has been observed in eruption every year. This makes it the most extreme member of the new class of Rapidly Recurring Novae (RRN) which show repeated eruptions within a time span of a decade or less. Such frequent outbursts indicate a high mass accretion rate onto a white dwarf that is extremely close to the Chandrasekhar limit, thereby making RRN the most promising observable candidates for the progenitors of type-Ia supernovae currently known.The previous three eruptions of M31N 2008-12a have displayed remarkably homogeneous multi-wavelength properties. From a relatively faint peak brightness the optical light curve declined rapidly by two magnitudes in less than two days. Early spectra showed high velocities that declined significantly within days and displayed clear helium and nitrogen lines throughout. The supersoft X-ray source phase of the nova began extremely early, around day six after eruption, and only lasted for about two weeks.In contrast, the delayed 2016 eruption showed significant deviations from the established pattern. In this talk, I will discuss the observational results and their impact on our understanding of the physics and evolution of this unique nova.

Environmental Factors and Internal Processes Contributing to Interrupted Rapid Decay of Hurricane Joaquin (2015)

NASA Astrophysics Data System (ADS)

Hendricks, E. A.; Elsberry, R. L.; Velden, C.; Creasey, R.; Jorgensen, A.; Jordan, M.

2017-12-01

Hurricane Joaquin (2015) was the most intense Atlantic hurricane with a non-tropical origin during the satellite era. In addition to its rapid intensification, Joaquin was noteworthy for the difficulty in forecasting its post-recurvature track to the northeast after having struck the Bahama Islands. Such a track typically leads to a decay as the hurricane moves poleward over colder water, and Joaquin had an extreme decay rate from 135 kt to 65 kt in only 30 h. The focus of this study is on the environmental and internal factors that interrupted this extreme decay at 1800 UTC 4 October, and then how Joaquin re-intensified to 75 kt and maintained that intensity for 30 hours. The real-time Statistical Hurricane Intensity Prediction System (SHIPS) database is used to calculate each six hours six environmental variables that Hendricks et al. (2010) had found contributed to intensity change. Only the deep-layer vertical wind shear (VWS) from SHIPS, and also from the Cooperative Institute for Meteorological Satellite Studies (CIMSS), had a well-defined relationship with both the interrupted rapid decay and the subsequent constant intensity period. A special dataset of Atmospheric Motion Vectors (AMVs) at 15-minute intervals prepared by CIMSS is then utilized to create a continuous VWS record that documents the large ( 15 m s-1) VWS throughout most of the rapid decay period, and then a rapid decrease in VWS to moderate ( 8 m s-1) values at and following the rapid decay period. Horizontal distributions of these CIMSS VWSs demonstrate that during this period Joaquin was located in a large gradient region between large VWSs to the north and near-zero VWSs to the south, which was favorable for sustaining Joaquin at hurricane intensity.

Causes of rapid uplift and exceptional topography of Gongga Shan on the eastern margin of the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Cook, Kristen L.; Hovius, Niels; Wittmann, Hella; Heimsath, Arjun M.; Lee, Yuan-Hsi

2018-01-01

Erosion and tectonic uplift are widely thought to be coupled through feedbacks involving orographic precipitation, relief development, and crustal weakening. In many orogenic systems, it can be difficult to distinguish whether true feedbacks exist, or whether observed features are a consequence of tectonic forcing. To help elucidate these interactions, we examine Gongga Shan, a 7556 m peak on the eastern margin of the Tibetan Plateau where cosmogenic 10Be basin-wide erosion rates reach >5 mm/yr, defining a region of localized rapid erosion associated with a restraining bend in the left-lateral Xianshuihe Fault. Erosion rates are consistent with topography, thermochronometry, and geodetic data, suggesting a stable pattern of uplift and exhumation over at least the past 2-3 My. Transpression along the Xianshuihe Fault, orographically enhanced precipitation, thermally weakened crust, and substantial local relief all developed independently in the Gongga region and existed there prior to the uplift of Gongga Shan. However, only where all of these conditions are present do the observed topographic and erosional extremes exist, and their relative timing indicates that these conditions are not a consequence of rapid uplift. We conclude that their collocation at 3-4 Ma set into motion a series of feedbacks between erosion and uplift that has resulted in the exceptionally high topography and rapid erosion rates observed today.

De Herschel à Alma. Les galaxies dévoilent enfin leurs secrets.

NASA Astrophysics Data System (ADS)

Elbaz, David

2016-08-01

With deep surveys, one can measure the amount of stars born in slices of the Universe and infer a "cosmic rate of star formation." The latest estimates from the Herschel satellite show a rapid drop of star formation in galaxies since ten billion years. To understand the cause of this fall, we can now measure the interstellar reservoirs of galaxies by combining observations from Herschel and the millimeter interferometer ALMA. Early results suggest that this fall comes from the rapid consumption of interstellar matter which served as reservoir to galaxies. Thanks to the technique of interferometry, ALMA can map interstellar dust within galaxies observed at the time of the peak of cosmic star formation, ten billion years ago. We discover that the stars of the most massive galaxies are born not only at very high rates but also with an extreme concentration.

Drought-induced shift of a forest–woodland ecotone: Rapid landscape response to climate variation

PubMed Central

Allen, Craig D.; Breshears, David D.

1998-01-01

In coming decades, global climate changes are expected to produce large shifts in vegetation distributions at unprecedented rates. These shifts are expected to be most rapid and extreme at ecotones, the boundaries between ecosystems, particularly those in semiarid landscapes. However, current models do not adequately provide for such rapid effects—particularly those caused by mortality—largely because of the lack of data from field studies. Here we report the most rapid landscape-scale shift of a woody ecotone ever documented: in northern New Mexico in the 1950s, the ecotone between semiarid ponderosa pine forest and piñon–juniper woodland shifted extensively (2 km or more) and rapidly (<5 years) through mortality of ponderosa pines in response to a severe drought. This shift has persisted for 40 years. Forest patches within the shift zone became much more fragmented, and soil erosion greatly accelerated. The rapidity and the complex dynamics of the persistent shift point to the need to represent more accurately these dynamics, especially the mortality factor, in assessments of the effects of climate change. PMID:9843976

Drought-induced shift of a forest-woodland ecotone: Rapid landscape response to climate variation

USGS Publications Warehouse

Allen, Craig D.; Breshears, David D.

1998-01-01

In coming decades, global climate changes are expected to produce large shifts in vegetation distributions at unprecedented rates. These shifts are expected to be most rapid and extreme at ecotones, the boundaries between ecosystems, particularly those in semiarid landscapes. However, current models do not adequately provide for such rapid effects—particularly those caused by mortality—largely because of the lack of data from field studies. Here we report the most rapid landscape-scale shift of a woody ecotone ever documented: in northern New Mexico in the 1950s, the ecotone between semiarid ponderosa pine forest and piñon–juniper woodland shifted extensively (2 km or more) and rapidly (<5 years) through mortality of ponderosa pines in response to a severe drought. This shift has persisted for 40 years. Forest patches within the shift zone became much more fragmented, and soil erosion greatly accelerated. The rapidity and the complex dynamics of the persistent shift point to the need to represent more accurately these dynamics, especially the mortality factor, in assessments of the effects of climate change.

Development of Untargeted Metabolomics Methods for the Rapid Detection of Pathogenic Naegleria fowleri.

PubMed

Yu, Zhihao; Miller, Haylea C; Puzon, Geoffrey J; Clowers, Brian H

2017-04-18

Despite comparatively low levels of infection, primary amoebic meningoencephalitis (PAM) induced by Naegleria fowleri is extremely lethal, with mortality rates above 95%. As a thermophile, this organism is often found in moderate-to-warm climates and has the potential to colonize drinking water distribution systems (DWDSs). Current detection approaches require days to obtain results, whereas swift corrective action can maximize the benefit of public health. Presently, there is little information regarding the underlying in situ metabolism for this amoeba but the potential exists to exploit differentially expressed metabolic signatures as a rapid detection technique. This research outlines the biochemical profiles of selected pathogenic and nonpathogenic Naegleria in vitro using an untargeted metabolomics approach to identify a panel of diagnostically meaningful compounds that may enable rapid detection of viable pathogenic N. fowleri and augment results from traditional monitoring approaches.

The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution.

PubMed

Baniaga, Anthony E; Arrigo, Nils; Barker, Michael S

2016-06-03

The haploid nuclear genome size (1C DNA) of vascular land plants varies over several orders of magnitude. Much of this observed diversity in genome size is due to the proliferation and deletion of transposable elements. To date, all vascular land plant lineages with extremely small nuclear genomes represent recently derived states, having ancestors with much larger genome sizes. The Selaginellaceae represent an ancient lineage with extremely small genomes. It is unclear how small nuclear genomes evolved in Selaginella We compared the rates of nuclear genome size evolution in Selaginella and major vascular plant clades in a comparative phylogenetic framework. For the analyses, we collected 29 new flow cytometry estimates of haploid genome size in Selaginella to augment publicly available data. Selaginella possess some of the smallest known haploid nuclear genome sizes, as well as the lowest rate of genome size evolution observed across all vascular land plants included in our analyses. Additionally, our analyses provide strong support for a history of haploid nuclear genome size stasis in Selaginella Our results indicate that Selaginella, similar to other early diverging lineages of vascular land plants, has relatively low rates of genome size evolution. Further, our analyses highlight that a rapid transition to a small genome size is only one route to an extremely small genome. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Rapid decadal convective precipitation increase over Eurasia during the last three decades of the 20th century.

PubMed

Ye, Hengchun; Fetzer, Eric J; Wong, Sun; Lambrigtsen, Bjorn H

2017-01-01

Convective precipitation-localized, short-lived, intense, and sometimes violent-is at the root of challenges associated with observation, simulation, and prediction of precipitation. The understanding of long-term changes in convective precipitation characteristics and their role in precipitation extremes and intensity over extratropical regions are imperative to future water resource management; however, they have been studied very little. We show that annual convective precipitation total has been increasing astonishingly fast, at a rate of 18.4%/°C, of which 16% is attributable to an increase in convective precipitation occurrence, and 2.4% is attributable to increased daily intensity based on the 35 years of two (combined) historical data sets of 3-hourly synoptic observations and daily precipitation. We also reveal that annual daily precipitation extreme has been increasing at a rate of about 7.4%/°C in convective events only. Concurrently, the overall increase in mean daily precipitation intensity is mostly due to increased convective precipitation, possibly at the expanse of nonconvective precipitation. As a result, transitional seasons are becoming more summer-like as convective becomes the dominant precipitation type that has accompanied higher daily extremes and intensity since the late 1980s. The data also demonstrate that increasing convective precipitation and daily extremes appear to be directly linearly associated with higher atmospheric water vapor accompanying a warming climate over northern Eurasia.

Rapid decadal convective precipitation increase over Eurasia during the last three decades of the 20th century

PubMed Central

Ye, Hengchun; Fetzer, Eric J.; Wong, Sun; Lambrigtsen, Bjorn H.

2017-01-01

Convective precipitation—localized, short-lived, intense, and sometimes violent—is at the root of challenges associated with observation, simulation, and prediction of precipitation. The understanding of long-term changes in convective precipitation characteristics and their role in precipitation extremes and intensity over extratropical regions are imperative to future water resource management; however, they have been studied very little. We show that annual convective precipitation total has been increasing astonishingly fast, at a rate of 18.4%/°C, of which 16% is attributable to an increase in convective precipitation occurrence, and 2.4% is attributable to increased daily intensity based on the 35 years of two (combined) historical data sets of 3-hourly synoptic observations and daily precipitation. We also reveal that annual daily precipitation extreme has been increasing at a rate of about 7.4%/°C in convective events only. Concurrently, the overall increase in mean daily precipitation intensity is mostly due to increased convective precipitation, possibly at the expanse of nonconvective precipitation. As a result, transitional seasons are becoming more summer-like as convective becomes the dominant precipitation type that has accompanied higher daily extremes and intensity since the late 1980s. The data also demonstrate that increasing convective precipitation and daily extremes appear to be directly linearly associated with higher atmospheric water vapor accompanying a warming climate over northern Eurasia. PMID:28138545

Extreme rainfall, vulnerability and risk: a continental-scale assessment for South America

USGS Publications Warehouse

Vorosmarty, Charles J.; de Guenni, Lelys Bravo; Wollheim, Wilfred M.; Pellerin, Brian A.; Bjerklie, David M.; Cardoso, Manoel; D'Almeida, Cassiano; Colon, Lilybeth

2013-01-01

Extreme weather continues to preoccupy society as a formidable public safety concern bearing huge economic costs. While attention has focused on global climate change and how it could intensify key elements of the water cycle such as precipitation and river discharge, it is the conjunction of geophysical and socioeconomic forces that shapes human sensitivity and risks to weather extremes. We demonstrate here the use of high-resolution geophysical and population datasets together with documentary reports of rainfall-induced damage across South America over a multi-decadal, retrospective time domain (1960–2000). We define and map extreme precipitation hazard, exposure, affectedpopulations, vulnerability and risk, and use these variables to analyse the impact of floods as a water security issue. Geospatial experiments uncover major sources of risk from natural climate variability and population growth, with change in climate extremes bearing a minor role. While rural populations display greatest relative sensitivity to extreme rainfall, urban settings show the highest rates of increasing risk. In the coming decades, rapid urbanization will make South American cities the focal point of future climate threats but also an opportunity for reducing vulnerability, protecting lives and sustaining economic development through both traditional and ecosystem-based disaster risk management systems.

Extreme Temperature Exceedances Change more Rapidly Under Future Warming in Regions of non-Gaussian Short Temperature Distribution Tails

NASA Astrophysics Data System (ADS)

Loikith, P. C.; Neelin, J. D.; Meyerson, J.

2017-12-01

Regions of shorter-than-Gaussian warm and cold side temperature distribution tails are shown to occur in spatially coherent patterns in the current climate. Under such conditions, warming may be manifested in more complex ways than if the underlying distribution were close to Gaussian. For example, under a uniform warm shift, the simplest prototype for future warming, a location with a short warm side tail would experience a greater increase in extreme warm exceedances compared to if the distribution were Gaussian. Similarly, for a location with a short cold side tail, a uniform warm shift would result in a rapid decrease in extreme cold exceedances. Both scenarios carry major societal and environmental implications including but not limited to negative impacts on human and ecosystem health, agriculture, and the economy. It is therefore important for climate models to be able to realistically reproduce short tails in simulations of historical climate in order to boost confidence in projections of future temperature extremes. Overall, climate models contributing to the fifth phase of the Coupled Model Intercomparison Project capture many of the principal observed regions of short tails. This suggests the underlying dynamics and physics occur on scales resolved by the models, and helps build confidence in model projections of extremes. Furthermore, most GCMs show more rapid changes in exceedances of extreme temperature thresholds in regions of short tails. Results therefore suggest that the shape of the tails of the underlying temperature distribution is an indicator of how rapidly a location will experience changes to extreme temperature occurrence under future warming.

Cracking the Stoping Paradigm: Field and Modeling Constraints From the Sierra Nevada Batholith

NASA Astrophysics Data System (ADS)

Pignotta, G. S.; Paterson, S. R.; Okaya, D.

2001-12-01

The significance of stoping during pluton emplacement remains a controversial issue. This mechanism has fallen out of favor recently largely due to the apparent lack of stoped blocks preserved in plutons. Our field studies in plutons in a variety of tectonic settings clearly show evidence of stoping. This is not surprising since stoping should be favored when large thermal gradients exist at magma-host rock boundaries. Preservation of stoped blocks is uncommon however, since the rate at which blocks sink is much greater than the rate at which magmas crystallize (Paterson and Okaya, 1999). Thus, only during final crystallization when magmatic yield strength is high, should stoped blocks be trapped. The Mitchell Peak granodiorite, Sierra Nevada is a rare example of a pluton that preserves abundant stoped blocks, with the youngest intrusive phase preserving >25% stoped blocks, and locally, near the margins >50% of exposed surface area is stoped blocks. Thus stoping is an important process here, at least during the final stages of emplacement. This area is ideal to study the mechanisms of block formation and disintegration using both field and modeling techniques, because of abundant stoped blocks, excellent exposure, and nature of host rock. The host rock is a slightly older, coarse grained, granodioritic intrusion that preserves extremely weak to no magmatic fabric, and thus can be treated as a "homogeneous and isotropic" medium for the purposes of thermal-mechanical modeling. Detailed mapping indicates that preserved stoped blocks range in size from hundreds of m's to xenocrystic feldspars, and there is abundant evidence for mechanical disintegration of blocks. Thermal-mechanical models, using detailed maps from the Mitchell Peak area, further support field observations. Rates at which thermal stresses develop and exceed host rock tensile strength are extremely rapid (hours to days) compared to onset of crystal plastic flow and/or melting. The calculated pattern of thermal stresses (i.e. high magnitudes at block corners) strongly supports rapid mechanical breakdown of stoped blocks. We suggest that rapid disintegration coupled with rapid rates of sinking of blocks explains the lack of observable blocks in plutons, and is an effective way to contaminate magmas thermally, mechanically and chemically. Furthermore, lack of observable stoped blocks in plutons should not be used as evidence that stoping did not occur.

The Burmese python genome reveals the molecular basis for extreme adaptation in snakes

PubMed Central

Castoe, Todd A.; de Koning, A. P. Jason; Hall, Kathryn T.; Card, Daren C.; Schield, Drew R.; Fujita, Matthew K.; Ruggiero, Robert P.; Degner, Jack F.; Daza, Juan M.; Gu, Wanjun; Reyes-Velasco, Jacobo; Shaney, Kyle J.; Castoe, Jill M.; Fox, Samuel E.; Poole, Alex W.; Polanco, Daniel; Dobry, Jason; Vandewege, Michael W.; Li, Qing; Schott, Ryan K.; Kapusta, Aurélie; Minx, Patrick; Feschotte, Cédric; Uetz, Peter; Ray, David A.; Hoffmann, Federico G.; Bogden, Robert; Smith, Eric N.; Chang, Belinda S. W.; Vonk, Freek J.; Casewell, Nicholas R.; Henkel, Christiaan V.; Richardson, Michael K.; Mackessy, Stephen P.; Bronikowski, Anne M.; Yandell, Mark; Warren, Wesley C.; Secor, Stephen M.; Pollock, David D.

2013-01-01

Snakes possess many extreme morphological and physiological adaptations. Identification of the molecular basis of these traits can provide novel understanding for vertebrate biology and medicine. Here, we study snake biology using the genome sequence of the Burmese python (Python molurus bivittatus), a model of extreme physiological and metabolic adaptation. We compare the python and king cobra genomes along with genomic samples from other snakes and perform transcriptome analysis to gain insights into the extreme phenotypes of the python. We discovered rapid and massive transcriptional responses in multiple organ systems that occur on feeding and coordinate major changes in organ size and function. Intriguingly, the homologs of these genes in humans are associated with metabolism, development, and pathology. We also found that many snake metabolic genes have undergone positive selection, which together with the rapid evolution of mitochondrial proteins, provides evidence for extensive adaptive redesign of snake metabolic pathways. Additional evidence for molecular adaptation and gene family expansions and contractions is associated with major physiological and phenotypic adaptations in snakes; genes involved are related to cell cycle, development, lungs, eyes, heart, intestine, and skeletal structure, including GRB2-associated binding protein 1, SSH, WNT16, and bone morphogenetic protein 7. Finally, changes in repetitive DNA content, guanine-cytosine isochore structure, and nucleotide substitution rates indicate major shifts in the structure and evolution of snake genomes compared with other amniotes. Phenotypic and physiological novelty in snakes seems to be driven by system-wide coordination of protein adaptation, gene expression, and changes in the structure of the genome. PMID:24297902

The Burmese python genome reveals the molecular basis for extreme adaptation in snakes.

PubMed

Castoe, Todd A; de Koning, A P Jason; Hall, Kathryn T; Card, Daren C; Schield, Drew R; Fujita, Matthew K; Ruggiero, Robert P; Degner, Jack F; Daza, Juan M; Gu, Wanjun; Reyes-Velasco, Jacobo; Shaney, Kyle J; Castoe, Jill M; Fox, Samuel E; Poole, Alex W; Polanco, Daniel; Dobry, Jason; Vandewege, Michael W; Li, Qing; Schott, Ryan K; Kapusta, Aurélie; Minx, Patrick; Feschotte, Cédric; Uetz, Peter; Ray, David A; Hoffmann, Federico G; Bogden, Robert; Smith, Eric N; Chang, Belinda S W; Vonk, Freek J; Casewell, Nicholas R; Henkel, Christiaan V; Richardson, Michael K; Mackessy, Stephen P; Bronikowski, Anne M; Bronikowsi, Anne M; Yandell, Mark; Warren, Wesley C; Secor, Stephen M; Pollock, David D

2013-12-17

Snakes possess many extreme morphological and physiological adaptations. Identification of the molecular basis of these traits can provide novel understanding for vertebrate biology and medicine. Here, we study snake biology using the genome sequence of the Burmese python (Python molurus bivittatus), a model of extreme physiological and metabolic adaptation. We compare the python and king cobra genomes along with genomic samples from other snakes and perform transcriptome analysis to gain insights into the extreme phenotypes of the python. We discovered rapid and massive transcriptional responses in multiple organ systems that occur on feeding and coordinate major changes in organ size and function. Intriguingly, the homologs of these genes in humans are associated with metabolism, development, and pathology. We also found that many snake metabolic genes have undergone positive selection, which together with the rapid evolution of mitochondrial proteins, provides evidence for extensive adaptive redesign of snake metabolic pathways. Additional evidence for molecular adaptation and gene family expansions and contractions is associated with major physiological and phenotypic adaptations in snakes; genes involved are related to cell cycle, development, lungs, eyes, heart, intestine, and skeletal structure, including GRB2-associated binding protein 1, SSH, WNT16, and bone morphogenetic protein 7. Finally, changes in repetitive DNA content, guanine-cytosine isochore structure, and nucleotide substitution rates indicate major shifts in the structure and evolution of snake genomes compared with other amniotes. Phenotypic and physiological novelty in snakes seems to be driven by system-wide coordination of protein adaptation, gene expression, and changes in the structure of the genome.

Impacts of extreme flooding on riverbank filtration water quality.

PubMed

Ascott, M J; Lapworth, D J; Gooddy, D C; Sage, R C; Karapanos, I

2016-06-01

Riverbank filtration schemes form a significant component of public water treatment processes on a global level. Understanding the resilience and water quality recovery of these systems following severe flooding is critical for effective water resources management under potential future climate change. This paper assesses the impact of floodplain inundation on the water quality of a shallow aquifer riverbank filtration system and how water quality recovers following an extreme (1 in 17 year, duration >70 days, 7 day inundation) flood event. During the inundation event, riverbank filtrate water quality is dominated by rapid direct recharge and floodwater infiltration (high fraction of surface water, dissolved organic carbon (DOC) >140% baseline values, >1 log increase in micro-organic contaminants, microbial detects and turbidity, low specific electrical conductivity (SEC) <90% baseline, high dissolved oxygen (DO) >400% baseline). A rapid recovery is observed in water quality with most floodwater impacts only observed for 2-3 weeks after the flooding event and a return to normal groundwater conditions within 6 weeks (lower fraction of surface water, higher SEC, lower DOC, organic and microbial detects, DO). Recovery rates are constrained by the hydrogeological site setting, the abstraction regime and the water quality trends at site boundary conditions. In this case, increased abstraction rates and a high transmissivity aquifer facilitate rapid water quality recoveries, with longer term trends controlled by background river and groundwater qualities. Temporary reductions in abstraction rates appear to slow water quality recoveries. Flexible operating regimes such as the one implemented at this study site are likely to be required if shallow aquifer riverbank filtration systems are to be resilient to future inundation events. Development of a conceptual understanding of hydrochemical boundaries and site hydrogeology through monitoring is required to assess the suitability of a prospective riverbank filtration site. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

[Necrotizing fasciitis of the upper and lower extremities].

PubMed

Kückelhaus, M; Hirsch, T; Lehnhardt, M; Daigeler, A

2017-04-01

Necrotizing fasciitis is a potentially fatal soft tissue infection that may affect the upper and lower extremities, scrotum, perineum and abdominal wall. Typically, the infection demonstrates rapid spreading along the fascial planes leading to sepsis with mortality rates of 15-46%. Without adequate treatment, the mortality rate increases to close to 100%. There are four groups of pathogens that can lead to necrotizing fasciitis, namely beta-hemolytic group A streptococci, mixed infections with obligate and facultative anaerobes, clostridium species and fungal infections. Clinical signs may include erythema, edema and pain out of proportion in the early stages and soft tissue necrosis with bullae during the subsequent course. In some cases, only a deterioration of the general condition is evident and the aforementioned clinical symptoms are initially missing. The decision for treatment is based on the clinical diagnosis and surgical debridement is the cornerstone of treatment, accompanied by broad spectrum i.v. antibiotic treatment, e. g. with penicillin, ciprofloxacin and clindamycin.

Late-Quaternary exhumation of Namche Barwa constrained using low-temperature multi-OSL-thermochronometry

NASA Astrophysics Data System (ADS)

King, Georgina; Herman, Frederic

2016-04-01

The influence of climate on tectonic processes remains a controversial concept. Exhumation rates of >5 mm/yr make Namche Barwa, Tibet, one of the most rapidly exhuming places on earth, and two main hypotheses have developed to explain the very high rates of exhumation there. The tectonic aneurysm model (Zeitler et al., 2001) proposes that crustal weakening coupled with extremely active surface processes causes a spatial stationarity of exhumation. Alternatively, a northward plunging antiform that is progressively migrating north-eastward (Seward and Burg, 2008) may explain the concentration of extremely low cooling ages and rapid exhumation that characterise the Namche Barwa massif. Here we use multi-OSL-thermochronometry of feldspar, which comprises a series of different systems with closure temperatures ranging from 30 to 70 C, to quantify spatial and temporal changes in exhumation rates. We have applied this new technique to a suite of samples from the Namche Barwa massif and inverting our data enables us to precisely resolve cooling histories over 0.1 Ma timescales. Our data indicate propagation of a knick-point along the Parlung river, which can be explained by progressive north-eastward migration of a northward plunging antiform. We suggest that river incision does not therefore feedback onto tectonics, as proposed by the aneurysm model. Zeitler, P.K., Meltzer, A.S., Koons, P.O., et al., 2001. Erosion, Himalayan Geodynamics, and the Geomorphology of Metamorphism. GSA Today 11, 4-9 Seward, D., Burg, J-P., 2008. Growth of the Namche Barwa Syntaxis and associated evolution of the Tsangpo Gorge: Constraints from structural and thermochronological data. Tectonophysics 451, 282-289.

A high-performance gradient insert for rapid and short-T2 imaging at full duty cycle.

PubMed

Weiger, Markus; Overweg, Johan; Rösler, Manuela Barbara; Froidevaux, Romain; Hennel, Franciszek; Wilm, Bertram Jakob; Penn, Alexander; Sturzenegger, Urs; Schuth, Wout; Mathlener, Menno; Borgo, Martino; Börnert, Peter; Leussler, Christoph; Luechinger, Roger; Dietrich, Benjamin Emanuel; Reber, Jonas; Brunner, David Otto; Schmid, Thomas; Vionnet, Laetitia; Pruessmann, Klaas P

2018-06-01

The goal of this study was to devise a gradient system for MRI in humans that reconciles cutting-edge gradient strength with rapid switching and brings up the duty cycle to 100% at full continuous amplitude. Aiming to advance neuroimaging and short-T 2 techniques, the hardware design focused on the head and the extremities as target anatomies. A boundary element method with minimization of power dissipation and stored magnetic energy was used to design anatomy-targeted gradient coils with maximally relaxed geometry constraints. The design relies on hollow conductors for high-performance cooling and split coils to enable dual-mode gradient amplifier operation. With this approach, strength and slew rate specifications of either 100 mT/m with 1200 mT/m/ms or 200 mT/m with 600 mT/m/ms were reached at 100% duty cycle, assuming a standard gradient amplifier and cooling unit. After manufacturing, the specified values for maximum gradient strength, maximum switching rate, and field geometry were verified experimentally. In temperature measurements, maximum local values of 63°C were observed, confirming that the device can be operated continuously at full amplitude. Testing for peripheral nerve stimulation showed nearly unrestricted applicability in humans at full gradient performance. In measurements of acoustic noise, a maximum average sound pressure level of 132 dB(A) was determined. In vivo capability was demonstrated by head and knee imaging. Full gradient performance was employed with echo planar and zero echo time readouts. Combining extreme gradient strength and switching speed without duty cycle limitations, the described system offers unprecedented options for rapid and short-T 2 imaging. Magn Reson Med 79:3256-3266, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

The global decline of cheetah Acinonyx jubatus and what it means for conservation.

PubMed

Durant, Sarah M; Mitchell, Nicholas; Groom, Rosemary; Pettorelli, Nathalie; Ipavec, Audrey; Jacobson, Andrew P; Woodroffe, Rosie; Böhm, Monika; Hunter, Luke T B; Becker, Matthew S; Broekhuis, Femke; Bashir, Sultana; Andresen, Leah; Aschenborn, Ortwin; Beddiaf, Mohammed; Belbachir, Farid; Belbachir-Bazi, Amel; Berbash, Ali; Brandao de Matos Machado, Iracelma; Breitenmoser, Christine; Chege, Monica; Cilliers, Deon; Davies-Mostert, Harriet; Dickman, Amy J; Ezekiel, Fabiano; Farhadinia, Mohammad S; Funston, Paul; Henschel, Philipp; Horgan, Jane; de Iongh, Hans H; Jowkar, Houman; Klein, Rebecca; Lindsey, Peter Andrew; Marker, Laurie; Marnewick, Kelly; Melzheimer, Joerg; Merkle, Johnathan; M'soka, Jassiel; Msuha, Maurus; O'Neill, Helen; Parker, Megan; Purchase, Gianetta; Sahailou, Samaila; Saidu, Yohanna; Samna, Abdoulkarim; Schmidt-Küntzel, Anne; Selebatso, Eda; Sogbohossou, Etotépé A; Soultan, Alaaeldin; Stone, Emma; van der Meer, Esther; van Vuuren, Rudie; Wykstra, Mary; Young-Overton, Kim

2017-01-17

Establishing and maintaining protected areas (PAs) are key tools for biodiversity conservation. However, this approach is insufficient for many species, particularly those that are wide-ranging and sparse. The cheetah Acinonyx jubatus exemplifies such a species and faces extreme challenges to its survival. Here, we show that the global population is estimated at ∼7,100 individuals and confined to 9% of its historical distributional range. However, the majority of current range (77%) occurs outside of PAs, where the species faces multiple threats. Scenario modeling shows that, where growth rates are suppressed outside PAs, extinction rates increase rapidly as the proportion of population protected declines. Sensitivity analysis shows that growth rates within PAs have to be high if they are to compensate for declines outside. Susceptibility of cheetah to rapid decline is evidenced by recent rapid contraction in range, supporting an uplisting of the International Union for the Conservation of Nature (IUCN) Red List threat assessment to endangered. Our results are applicable to other protection-reliant species, which may be subject to systematic underestimation of threat when there is insufficient information outside PAs. Ultimately, conserving many of these species necessitates a paradigm shift in conservation toward a holistic approach that incentivizes protection and promotes sustainable human-wildlife coexistence across large multiple-use landscapes.

The global decline of cheetah Acinonyx jubatus and what it means for conservation

PubMed Central

Mitchell, Nicholas; Groom, Rosemary; Pettorelli, Nathalie; Ipavec, Audrey; Jacobson, Andrew P.; Woodroffe, Rosie; Böhm, Monika; Becker, Matthew S.; Broekhuis, Femke; Bashir, Sultana; Andresen, Leah; Aschenborn, Ortwin; Beddiaf, Mohammed; Berbash, Ali; Brandao de Matos Machado, Iracelma; Breitenmoser, Christine; Chege, Monica; Cilliers, Deon; Davies-Mostert, Harriet; Dickman, Amy J.; Ezekiel, Fabiano; Farhadinia, Mohammad S.; Funston, Paul; Henschel, Philipp; Horgan, Jane; de Iongh, Hans H.; Jowkar, Houman; Klein, Rebecca; Lindsey, Peter Andrew; Marker, Laurie; Marnewick, Kelly; Melzheimer, Joerg; Merkle, Johnathan; M'soka, Jassiel; Msuha, Maurus; O'Neill, Helen; Parker, Megan; Purchase, Gianetta; Sahailou, Samaila; Saidu, Yohanna; Samna, Abdoulkarim; Schmidt-Küntzel, Anne; Selebatso, Eda; Sogbohossou, Etotépé A.; Stone, Emma; van der Meer, Esther; van Vuuren, Rudie; Wykstra, Mary; Young-Overton, Kim

2017-01-01

Establishing and maintaining protected areas (PAs) are key tools for biodiversity conservation. However, this approach is insufficient for many species, particularly those that are wide-ranging and sparse. The cheetah Acinonyx jubatus exemplifies such a species and faces extreme challenges to its survival. Here, we show that the global population is estimated at ∼7,100 individuals and confined to 9% of its historical distributional range. However, the majority of current range (77%) occurs outside of PAs, where the species faces multiple threats. Scenario modeling shows that, where growth rates are suppressed outside PAs, extinction rates increase rapidly as the proportion of population protected declines. Sensitivity analysis shows that growth rates within PAs have to be high if they are to compensate for declines outside. Susceptibility of cheetah to rapid decline is evidenced by recent rapid contraction in range, supporting an uplisting of the International Union for the Conservation of Nature (IUCN) Red List threat assessment to endangered. Our results are applicable to other protection-reliant species, which may be subject to systematic underestimation of threat when there is insufficient information outside PAs. Ultimately, conserving many of these species necessitates a paradigm shift in conservation toward a holistic approach that incentivizes protection and promotes sustainable human–wildlife coexistence across large multiple-use landscapes. PMID:28028225

Genetics of Rapid and Extreme Size Evolution in Island Mice

PubMed Central

Gray, Melissa M.; Parmenter, Michelle D.; Hogan, Caley A.; Ford, Irene; Cuthbert, Richard J.; Ryan, Peter G.; Broman, Karl W.; Payseur, Bret A.

2015-01-01

Organisms on islands provide a revealing window into the process of adaptation. Populations that colonize islands often evolve substantial differences in body size from their mainland relatives. Although the ecological drivers of this phenomenon have received considerable attention, its genetic basis remains poorly understood. We use house mice (subspecies: Mus musculus domesticus) from remote Gough Island to provide a genetic portrait of rapid and extreme size evolution. In just a few hundred generations, Gough Island mice evolved the largest body size among wild house mice from around the world. Through comparisons with a smaller-bodied wild-derived strain from the same subspecies (WSB/EiJ), we demonstrate that Gough Island mice achieve their exceptional body weight primarily by growing faster during the 6 weeks after birth. We use genetic mapping in large F2 intercrosses between Gough Island mice and WSB/EiJ to identify 19 quantitative trait loci (QTL) responsible for the evolution of 16-week weight trajectories: 8 QTL for body weight and 11 QTL for growth rate. QTL exhibit modest effects that are mostly additive. We conclude that body size evolution on islands can be genetically complex, even when substantial size changes occur rapidly. In comparisons to published studies of laboratory strains of mice that were artificially selected for divergent body sizes, we discover that the overall genetic profile of size evolution in nature and in the laboratory is similar, but many contributing loci are distinct. Our results underscore the power of genetically characterizing the entire growth trajectory in wild populations and lay the foundation necessary for identifying the mutations responsible for extreme body size evolution in nature. PMID:26199233

Genetics of Rapid and Extreme Size Evolution in Island Mice.

PubMed

Gray, Melissa M; Parmenter, Michelle D; Hogan, Caley A; Ford, Irene; Cuthbert, Richard J; Ryan, Peter G; Broman, Karl W; Payseur, Bret A

2015-09-01

Organisms on islands provide a revealing window into the process of adaptation. Populations that colonize islands often evolve substantial differences in body size from their mainland relatives. Although the ecological drivers of this phenomenon have received considerable attention, its genetic basis remains poorly understood. We use house mice (subspecies: Mus musculus domesticus) from remote Gough Island to provide a genetic portrait of rapid and extreme size evolution. In just a few hundred generations, Gough Island mice evolved the largest body size among wild house mice from around the world. Through comparisons with a smaller-bodied wild-derived strain from the same subspecies (WSB/EiJ), we demonstrate that Gough Island mice achieve their exceptional body weight primarily by growing faster during the 6 weeks after birth. We use genetic mapping in large F(2) intercrosses between Gough Island mice and WSB/EiJ to identify 19 quantitative trait loci (QTL) responsible for the evolution of 16-week weight trajectories: 8 QTL for body weight and 11 QTL for growth rate. QTL exhibit modest effects that are mostly additive. We conclude that body size evolution on islands can be genetically complex, even when substantial size changes occur rapidly. In comparisons to published studies of laboratory strains of mice that were artificially selected for divergent body sizes, we discover that the overall genetic profile of size evolution in nature and in the laboratory is similar, but many contributing loci are distinct. Our results underscore the power of genetically characterizing the entire growth trajectory in wild populations and lay the foundation necessary for identifying the mutations responsible for extreme body size evolution in nature. Copyright © 2015 by the Genetics Society of America.

Miniaturized Stretchable and High-Rate Linear Supercapacitors

NASA Astrophysics Data System (ADS)

Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

2017-07-01

Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electrodes. Furthermore, we have developed fine stretchable linear supercapacitors, which exhibited an extremely high elasticity up to 400% strain with a high capacitance of about 8.7 F g-1 at the discharge current of 1 A g-1.

Miniaturized Stretchable and High-Rate Linear Supercapacitors.

PubMed

Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

2017-12-01

Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electrodes. Furthermore, we have developed fine stretchable linear supercapacitors, which exhibited an extremely high elasticity up to 400% strain with a high capacitance of about 8.7 F g -1 at the discharge current of 1 A g -1 .

Accelerated Mutation Accumulation in Asexual Lineages of a Freshwater Snail

PubMed Central

Neiman, Maurine; Hehman, Gery; Miller, Joseph T.; Logsdon, John M.; Taylor, Douglas R.

2010-01-01

Sexual reproduction is both extremely costly and widespread relative to asexual reproduction, meaning that it must also confer profound advantages in order to persist. One theorized benefit of sex is that it facilitates the clearance of harmful mutations, which would accumulate more rapidly in the absence of recombination. The extent to which ineffective purifying selection and mutation accumulation are direct consequences of asexuality and whether the accelerated buildup of harmful mutations in asexuals can occur rapidly enough to maintain sex within natural populations, however, remain as open questions. We addressed key components of these questions by estimating the rate of mutation accumulation in the mitochondrial genomes of multiple sexual and asexual representatives of Potamopyrgus antipodarum, a New Zealand snail characterized by mixed sexual/asexual populations. We found that increased mutation accumulation is associated with asexuality and occurs rapidly enough to be detected in recently derived asexual lineages of P. antipodarum. Our results demonstrate that increased mutation accumulation in asexuals can differentially affect coexisting and ecologically similar sexual and asexual lineages. The accelerated rate of mutation accumulation observed in asexual P. antipodarum provides some of the most direct evidence to date for a link between asexuality and mutation accumulation and implies that mutational buildup could be rapid enough to contribute to the short-term evolutionary mechanisms that favor sexual reproduction. PMID:19995828

Transient Response to Rapid Cooling of a Stainless Steel Sodium Heat Pipe

NASA Technical Reports Server (NTRS)

Mireles, Omar R.; Houts, Michael G.

2011-01-01

Compact fission power systems are under consideration for use in long duration space exploration missions. Power demands on the order of 500 W, to 5 kW, will be required for up to 15 years of continuous service. One such small reactor design consists of a fast spectrum reactor cooled with an array of in-core alkali metal heat pipes coupled to thermoelectric or Stirling power conversion systems. Heat pipes advantageous attributes include a simplistic design, lack of moving parts, and well understood behavior. Concerns over reactor transients induced by heat pipe instability as a function of extreme thermal transients require experimental investigations. One particular concern is rapid cooling of the heat pipe condenser that would propagate to cool the evaporator. Rapid cooling of the reactor core beyond acceptable design limits could possibly induce unintended reactor control issues. This paper discusses a series of experimental demonstrations where a heat pipe operating at near prototypic conditions experienced rapid cooling of the condenser. The condenser section of a stainless steel sodium heat pipe was enclosed within a heat exchanger. The heat pipe - heat exchanger assembly was housed within a vacuum chamber held at a pressure of 50 Torr of helium. The heat pipe was brought to steady state operating conditions using graphite resistance heaters then cooled by a high flow of gaseous nitrogen through the heat exchanger. Subsequent thermal transient behavior was characterized by performing an energy balance using temperature, pressure and flow rate data obtained throughout the tests. Results indicate the degree of temperature change that results from a rapid cooling scenario will not significantly influence thermal stability of an operating heat pipe, even under extreme condenser cooling conditions.

Introduction

NASA Astrophysics Data System (ADS)

Bouma, Brett E.

1998-09-01

The pace of technological advancement of Optical Coherence Tomography (OCT) over the last several years has been extremely rapid. The field has progressed from one-dimensional low-coherence ranging to full three-dimensional imaging with individual two-dimensional images aquired at near video rate in a span of less than eight years. Imaging applications have included polymers and advanced composites, Ophthalmology, Developmental Biology, Gastroenterology, Urology, Cardiology, Neurology, and Gynecology. These preliminary studies indicate the great potential for OCT to make a significant impact, especially in clinical medicine.

Growth analysis of pulmonary metastases from salivary gland tumors.

PubMed

Twardzik, F G; Sklaroff, D M

1976-03-01

Three cases of primary salivary gland tumors with lung metastasis are presented with extremely long survival (six, ten, and twelve years). The tumor doubling time was calculated and the growth rate of the pulmonary metastasis was found to be slow and erratic. A simplified table was devised, which permits rapid calculation of the tumor doubling time without the use of graphs. The presence of lung metastasis from some primary malignant salivary tumor is not necessarily an ominous sign: a long survival without symtoms is possible.

A case report for fatal Churg-Strauss syndrome complications: first reported death due to rapid progression of prominently huge hepatic capsular hematoma and multi-system organ hemorrhage

PubMed Central

Qian, Jiejing; Tong, Hongyan; Chen, Feifei; Mai, Wenyuan; Lou, Yinjun; Jin, Jie

2014-01-01

Churg-Strauss syndrome (CSS) is a rare disease that has an extremely low incidence rate. CSS prognosis is good, in general; and there are no reports of multiple-organ hemorrhage in CSS. We report a unique case of CSS, wherein, an elderly man experienced multiple organ hemorrhage -- a particularly huge hematoma under the capsule of the liver and poor prognosis. PMID:25419420

On the use of star-shaped genealogies in inference of coalescence times.

PubMed Central

Rosenberg, Noah A; Hirsh, Aaron E

2003-01-01

Genealogies from rapidly growing populations have approximate "star" shapes. We study the degree to which this approximation holds in the context of estimating the time to the most recent common ancestor (T(MRCA)) of a set of lineages. In an exponential growth scenario, we find that unless the product of population size (N) and growth rate (r) is at least approximately 10(5), the "pairwise comparison estimator" of T(MRCA) that derives from the star genealogy assumption has bias of 10-50%. Thus, the estimator is appropriate only for large populations that have grown very rapidly. The "tree-length estimator" of T(MRCA) is more biased than the pairwise comparison estimator, having low bias only for extremely large values of Nr. PMID:12930771

Enamel formation and growth in non-mammalian cynodonts

PubMed Central

Dirks, Wendy; Martinelli, Agustín G.

2018-01-01

The early evolution of mammals is associated with the linked evolutionary origin of diphyodont tooth replacement, rapid juvenile growth and determinate adult growth. However, specific relationships among these characters during non-mammalian cynodont evolution require further exploration. Here, polarized light microscopy revealed incremental lines, resembling daily laminations of extant mammals, in histological sections of enamel in eight non-mammalian cynodont species. In the more basal non-probainognathian group, enamel extends extremely rapidly from cusp to cervix. By contrast, the enamel of mammaliamorphs is gradually accreted, with slow rates of crown extension, more typical of the majority of non-hypsodont crown mammals. These results are consistent with the reduction in dental replacement rate across the non-mammalian cynodont lineage, with greater rates of crown extension required in most non-probainognathians, and slower crown extension rates permitted in mammaliamorphs, which have reduced patterns of dental replacement in comparison with many non-probainognathians. The evolution of mammal-like growth patterns, with faster juvenile growth and more abruptly terminating adult growth, is linked with this reduction in dental replacement rates and may provide an additional explanation for the observed pattern in enamel growth rates. It is possible that the reduction in enamel extension rates in mammaliamorphs reflects an underlying reduction in skeletal growth rates at the time of postcanine formation, due to a more abruptly terminating pattern of adult growth in these more mammal-like, crownward species. PMID:29892415

Circulation and metabolic rates in a natural hibernator: an integrative physiological model

PubMed Central

Nelson, Bethany T.; Andrews, Matthew T.

2010-01-01

Small hibernating mammals show regular oscillations in their heart rate and body temperature throughout the winter. Long periods of torpor are abruptly interrupted by arousals with heart rates that rapidly increase from 5 beats/min to over 400 beats/min and body temperatures that increase by ∼30°C only to drop back into the hypothermic torpid state within hours. Surgically implanted transmitters were used to obtain high-resolution electrocardiogram and body temperature data from hibernating thirteen-lined ground squirrels (Spermophilus tridecemlineatus). These data were used to construct a model of the circulatory system to gain greater understanding of these rapid and extreme changes in physiology. Our model provides estimates of metabolic rates during the torpor-arousal cycles in different model compartments that would be difficult to measure directly. In the compartment that models the more metabolically active tissues and organs (heart, brain, liver, and brown adipose tissue) the peak metabolic rate occurs at a core body temperature of 19°C approximately midway through an arousal. The peak metabolic rate of the active tissues is nine times the normothermic rate after the arousal is complete. For the overall metabolic rate in all tissues, the peak-to-resting ratio is five. This value is high for a rodent, which provides evidence for the hypothesis that the arousal from torpor is limited by the capabilities of the cardiovascular system. PMID:20844258

Cell wall metabolism and hexose allocation contribute to biomass accumulation in high yielding extreme segregants of a Saccharum interspecific F2 population.

PubMed

Wai, Ching Man; Zhang, Jisen; Jones, Tyler C; Nagai, Chifumi; Ming, Ray

2017-10-11

Sugarcane is an emerging dual-purpose biofuel crop for energy and sugar production, owing to its rapid growth rate, high sucrose storage in the stems, and high lignocellulosic yield. It has the highest biomass production reaching 1.9 billion tonnes in 2014 worldwide. To improve sugarcane biomass accumulation, we developed an interspecific cross between Saccharum officinarum 'LA Purple' and Saccharum robustum 'MOL5829'. Selected F1 individuals were self-pollinated to generate a transgressive F2 population with a wide range of biomass yield. Leaf and stem internodes of fourteen high biomass and eight low biomass F2 extreme segregants were used for RNA-seq to decipher the molecular mechanism of rapid plant growth and dry weight accumulation. Gene Ontology terms involved in cell wall metabolism and carbohydrate catabolism were enriched among 3274 differentially expressed genes between high and low biomass groups. Up-regulation of cellulose metabolism, pectin degradation and lignin biosynthesis genes were observed in the high biomass group, in conjunction with higher transcript levels of callose metabolic genes and the cell wall loosening enzyme expansin. Furthermore, UDP-glucose biosynthesis and sucrose conversion genes were differentially expressed between the two groups. A positive correlation between stem glucose, but not sucrose, levels and dry weight was detected. We thus postulated that the high biomass sugarcane plants rapidly convert sucrose to UDP-glucose, which is the building block of cell wall polymers and callose, in order to maintain the rapid plant growth. The gene interaction of cell wall metabolism, hexose allocation and cell division contributes to biomass yield.

Pliocene eclogite exhumation at plate tectonic rates in eastern Papua New Guinea.

PubMed

Baldwin, Suzanne L; Monteleone, Brian D; Webb, Laura E; Fitzgerald, Paul G; Grove, Marty; Hill, E June

2004-09-16

As lithospheric plates are subducted, rocks are metamorphosed under high-pressure and ultrahigh-pressure conditions to produce eclogites and eclogite facies metamorphic rocks. Because chemical equilibrium is rarely fully achieved, eclogites may preserve in their distinctive mineral assemblages and textures a record of the pressures, temperatures and deformation the rock was subjected to during subduction and subsequent exhumation. Radioactive parent-daughter isotopic variations within minerals reveal the timing of these events. Here we present in situ zircon U/Pb ion microprobe data that dates the timing of eclogite facies metamorphism in eastern Papua New Guinea at 4.3 +/- 0.4 Myr ago, making this the youngest documented eclogite exposed at the Earth's surface. Eclogite exhumation from depths of approximately 75 km was extremely rapid and occurred at plate tectonic rates (cm yr(-1)). The eclogite was exhumed within a portion of the obliquely convergent Australian-Pacific plate boundary zone, in an extending region located west of the Woodlark basin sea floor spreading centre. Such rapid exhumation (> 1 cm yr(-1)) of high-pressure and, we infer, ultrahigh-pressure rocks is facilitated by extension within transient plate boundary zones associated with rapid oblique plate convergence.

Primary (de novo) dedifferentiated liposarcoma in the extremities: a multi-institution Tohoku Musculoskeletal Tumor Society study of 18 cases in northern Japan.

PubMed

Okada, Kyoji; Hasegawa, Tadashi; Kawai, Akira; Ogose, Akira; Nishida, Jun; Yanagisawa, Michiro; Morita, Tetsuro; Tajino, Takahiro; Tsuchiya, Takashi

2011-09-01

Dedifferentiated liposarcomas usually occur in the retroperitoneal space and relatively rarely in the extremities. We identified 18 patients with primary dedifferentiated liposarcoma in the extremities from the files of Tohoku Musculoskeletal Tumor Society and analyzed demographics, histologic findings, treatments and prognostic factors. The average follow-up period was 58 months. The subjects were 12 men and 6 women with a mean age of 65 years. All tumors were in the thigh. Nine patients noticed a rapid enlargement of the long-standing tumor. Histologic subtypes of the dedifferentiated area were undifferentiated pleomorphic sarcoma (n = 12), osteosarcoma (n = 2), rhabdomyosarcoma (n = 2), leiomyosarcoma (n = 1) and malignant peripheral nerve sheath tumor (n = 1). In the patient with rhabdomyosarcoma-like dedifferentiated area, extensive necrosis was observed after the preoperative chemotherapy. One patient who underwent marginal excision developed a local recurrence, but inadequate surgical margin was not associated with a risk of local recurrence. Three patients had lung metastasis at initial presentation, and four other patients developed lung metastases during the follow-up period. The overall survival rate was 61.1% at 5 years. On univariate analyses, large size of the dedifferentiated area (>8 cm), high MIB-1-labeling index (>30%) for the dedifferentiated area and lung metastasis at initial presentation were significantly associated with poor prognosis. Primary dedifferentiated liposarcoma in the extremities predominantly occurred in the thigh and a rapid enlargement of long-standing tumors was a characteristic symptom. Although the local behavior of these tumors was less aggressive than that of retroperitoneal dedifferentiated liposarcomas, they had a relatively high metastatic potential.

Effect of Mn and Fe on the Formation of Fe- and Mn-Rich Intermetallics in Al-5Mg-Mn Alloys Solidified Under Near-Rapid Cooling.

PubMed

Liu, Yulin; Huang, Gaoren; Sun, Yimeng; Zhang, Li; Huang, Zhenwei; Wang, Jijie; Liu, Chunzhong

2016-01-29

Mn was an important alloying element used in Al-Mg-Mn alloys. However, it had to be limited to a low level (<1.0 wt %) to avoid the formation of coarse intermetallics. In order to take full advantage of the benefits of Mn, research was carried out to investigate the possibility of increasing the content of Mn by studying the effect of cooling rate on the formation of Fe- and Mn-rich intermetallics at different content levels of Mn and Fe. The results indicated that in Al-5Mg-Mn alloy with low Fe content (<0.1 wt %), intermetallic Al₆(Fe,Mn) was small in size and amount. With increasing Mn content, intermetallic Al₆(Fe,Mn) increased, but in limited amount. In high-Fe-containing Al-5Mg-Mn alloys (0.5 wt % Fe), intermetallic Al₆(Fe,Mn) became the dominant phase, even in the alloy with low Mn content (0.39 wt %). Cooling rate played a critical role in the refinement of the intermetallics. Under near-rapid cooling, intermetallic Al₆(Fe,Mn) was extremely refined. Even in the high Mn and/or high-Fe-containing alloys, it still demonstrated fine Chinese script structures. However, once the alloy composition passed beyond the eutectic point, the primary intermetallic Al₆(Fe,Mn) phase displayed extremely coarse platelet-like morphology. Increasing the content of Fe caused intermetallic Al₆(Fe,Mn) to become the primary phase at a lower Mn content.

Americium-241 and plutonium-237 turnover in mussels ( Mytilus galloprovincialis) living in field enclosures

NASA Astrophysics Data System (ADS)

Guary, J. C.; Fowler, S. W.

1981-02-01

Loss of 241Am and 237Pu from contaminated mussels ( Mytilus galloprovincialis) living in situ in the Mediterranean Sea is described as the sum of three exponential functions. In the case of 241Am, two short-lived compartments representing a total of 80% of the incorporated radionuclide turned over rapidly with biological half-lives of 2 and 3 weeks. The remaining fraction of 241Am, associated with a long-lived compartment, was lost at an extremely slow rate ( Tb1/2=1·3 years). Plutonium-237 turnover in the two short-lived compartments (containing 70% of the Pu) was more rapid ( Tb1/2=1-2 days and 2 weeks) than that of 241Am; however, there was some indication that subsequent loss rates of the two radionuclides in long-lived compartments may be similar if determined over comparable periods of time. Loss rates of 241Am differed for the various tissues, with the most rapid rates occurring in gill, viscera and shell. Abrupt changes in loss observed in muscle and mantle suggested a translocation of 241Am to muscle and mantle during depuration. Whole shell contained by far the largest fraction (˜90%) of both 241Am and 237Pu taken up; in addition, these radionuclides are not irreversibly bound to mussel shell but readily leach into the water. These observations suggest that mollusc shell may influence the biogeochemistry of transuranic elements in littoral zones.

High Resolution Simulation of a Colorado Rockies Extreme Snow and Rain Event in both a Current and Future Climate

NASA Astrophysics Data System (ADS)

Rasmussen, Roy; Ikeda, Kyoko; Liu, Changhai; Gutmann, Ethan; Gochis, David

2016-04-01

Modeling of extreme weather events often require very finely resolved treatment of atmospheric circulation structures in order to produce and localize the large moisture fluxes that result in extreme precipitation. This is particularly true for cool season orographic precipitation processes where the representation of the landform can significantly impact vertical velocity profiles and cloud moisture entrainment rates. This study presents results for high resolution regional climate modeling study of the Colorado Headwaters region using an updated version of the Weather Research and Forecasting (WRF) model run at 4 km horizontal resolution and a hydrological extension package called WRF-Hydro. Previous work has shown that the WRF modeling system can produce credible depictions of winter orographic precipitation over the Colorado Rockies if run at horizontal resolutions < 6 km. Here we present results from a detailed study of an extreme springtime snowfall event that occurred along the Colorado Front Range in March 2003. Results from the impact of warming on total precipitation, snow-rain partitioning and surface hydrological fluxes (evapotranspiration and runoff) will be discussed in the context of how potential changes in temperature impact the amount of precipitation, the phase of precipitation (rain vs. snow) and the timing and amplitude of streamflow responses. The results show using the Pseudo Global Warming technique that intense precipitation rates significantly increased during the event and a significant fraction of the snowfall converts to rain which significantly amplifies the runoff response from one where runoff is produced gradually to one in which runoff is rapidly translated into streamflow values that approach significant flooding risks. Results from a new, CONUS scale high resolution climate simulation of extreme events in a current and future climate will be presented as time permits.

Electrostatic Interactions in the Binding Pathway of a Transient Protein Complex Studied by NMR and Isothermal Titration Calorimetry*

PubMed Central

Meneses, Erick; Mittermaier, Anthony

2014-01-01

Much of our knowledge of protein binding pathways is derived from extremely stable complexes that interact very tightly, with lifetimes of hours to days. Much less is known about weaker interactions and transient complexes because these are challenging to characterize experimentally. Nevertheless, these types of interactions are ubiquitous in living systems. The combination of NMR relaxation dispersion Carr–Purcell–Meiboom–Gill (CPMG) experiments and isothermal titration calorimetry allows the quantification of rapid binding kinetics for complexes with submillisecond lifetimes that are difficult to study using conventional techniques. We have used this approach to investigate the binding pathway of the Src homology 3 (SH3) domain from the Fyn tyrosine kinase, which forms complexes with peptide targets whose lifetimes are on the order of about a millisecond. Long range electrostatic interactions have been shown to play a critical role in the binding pathways of tightly binding complexes. The role of electrostatics in the binding pathways of transient complexes is less well understood. Similarly to previously studied tight complexes, we find that SH3 domain association rates are enhanced by long range electrostatics, whereas short range interactions are formed late in the docking process. However, the extent of electrostatic association rate enhancement is several orders of magnitudes less, whereas the electrostatic-free basal association rate is significantly greater. Thus, the SH3 domain is far less reliant on electrostatic enhancement to achieve rapid association kinetics than are previously studied systems. This suggests that there may be overall differences in the role played by electrostatics in the binding pathways of extremely stable versus transient complexes. PMID:25122758

Dynamics of Superoxide Production and Decay in Natural Trichodesmium Colonies from the Sargasso Sea: Implications for Cell Signaling

NASA Astrophysics Data System (ADS)

Hansel, C. M.; Buchwald, C.; Diaz, J. M.; Dyhrman, S.; Van Mooy, B. A. S.

2014-12-01

Reactive oxygen species (ROS) are key players in the biogeochemistry of the ocean, where they serve a critical role in the cycling of carbon and metals. Research in the past decade has introduced phytoplankton and, most recently, heterotrophic bacteria as significant sources of ROS, including superoxide, within both photic and aphotic regions of the ocean. ROS are both beneficial and detrimental to life. For instance, superoxide is a vital inter- and intra-cellular signaling molecule, yet at high concentrations it induces lipid peroxidation and initiates programmed cell death (PCD). In fact, superoxide has been implicated in PCD in the nitrogen-fixing diazotroph Trichodesmium, presumably leading to the demise of blooms within oligotrophic marine systems. Here, we explore the rates of superoxide production and decay by natural Trichodesmium populations obtained from various surface waters in the Sargasso Sea. We investigate also the role of light and colony density and morphology (puff v. raft) on superoxide fluxes. We find that Trichodesmium colonies produce extracellular superoxide at extremely high rates in the dark that are on par with those of the toxic raphidophyte Chattonella. The rates of superoxide production, however, rapidly decline with increasing cell density pointing to a role for superoxide in cell signaling in these organisms. We also find extremely rapid extracellular superoxide degradation by Trichodesmium. Together, this likely reflects a need for these organisms to maintain ROS at levels that will support signaling but below the threshold level that triggers PCD or oxidative damage. We also show differences in the effect of light on superoxide fluxes as a function of Trichodesmium colony morphology, suggesting differences in either colony physiology or associated bacterial symbionts. These findings point to complex physiological, ecological, and physical influences on ROS dynamics in phytoplankton that require further exploration.

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

Khan, Fazeel Mahmood; Holley-Bockelmann, Kelly; Berczik, Peter, E-mail: khan@ari.uni-heidelberg.de, E-mail: k.holley@vanderbilt.edu

Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC 1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the largemore » SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC 1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10 Myr. By the time the SMBHs form a hard binary, gravitational wave emission dominates, and the black holes coalesce in a mere few Myr. Curiously, these extremely massive binaries appear to nearly bypass the three-body scattering evolutionary phase. Our study suggests that in this extreme case, SMBH coalescence is governed by dynamical friction followed nearly directly by gravitational wave emission, resulting in a rapid and efficient SMBH coalescence timescale. We discuss the implications for gravitational wave event rates and hypervelocity star production.« less

Vaccination strategies for future influenza pandemics: a severity-based cost effectiveness analysis

PubMed Central

2013-01-01

Background A critical issue in planning pandemic influenza mitigation strategies is the delay between the arrival of the pandemic in a community and the availability of an effective vaccine. The likely scenario, born out in the 2009 pandemic, is that a newly emerged influenza pandemic will have spread to most parts of the world before a vaccine matched to the pandemic strain is produced. For a severe pandemic, additional rapidly activated intervention measures will be required if high mortality rates are to be avoided. Methods A simulation modelling study was conducted to examine the effectiveness and cost effectiveness of plausible combinations of social distancing, antiviral and vaccination interventions, assuming a delay of 6-months between arrival of an influenza pandemic and first availability of a vaccine. Three different pandemic scenarios were examined; mild, moderate and extreme, based on estimates of transmissibility and pathogenicity of the 2009, 1957 and 1918 influenza pandemics respectively. A range of different durations of social distancing were examined, and the sensitivity of the results to variation in the vaccination delay, ranging from 2 to 6 months, was analysed. Results Vaccination-only strategies were not cost effective for any pandemic scenario, saving few lives and incurring substantial vaccination costs. Vaccination coupled with long duration social distancing, antiviral treatment and antiviral prophylaxis was cost effective for moderate pandemics and extreme pandemics, where it saved lives while simultaneously reducing the total pandemic cost. Combined social distancing and antiviral interventions without vaccination were significantly less effective, since without vaccination a resurgence in case numbers occurred as soon as social distancing interventions were relaxed. When social distancing interventions were continued until at least the start of the vaccination campaign, attack rates and total costs were significantly lower, and increased rates of vaccination further improved effectiveness and cost effectiveness. Conclusions The effectiveness and cost effectiveness consequences of the time-critical interplay of pandemic dynamics, vaccine availability and intervention timing has been quantified. For moderate and extreme pandemics, vaccination combined with rapidly activated antiviral and social distancing interventions of sufficient duration is cost effective from the perspective of life years saved. PMID:23398722

Vaccination strategies for future influenza pandemics: a severity-based cost effectiveness analysis.

PubMed

Kelso, Joel K; Halder, Nilimesh; Milne, George J

2013-02-11

A critical issue in planning pandemic influenza mitigation strategies is the delay between the arrival of the pandemic in a community and the availability of an effective vaccine. The likely scenario, born out in the 2009 pandemic, is that a newly emerged influenza pandemic will have spread to most parts of the world before a vaccine matched to the pandemic strain is produced. For a severe pandemic, additional rapidly activated intervention measures will be required if high mortality rates are to be avoided. A simulation modelling study was conducted to examine the effectiveness and cost effectiveness of plausible combinations of social distancing, antiviral and vaccination interventions, assuming a delay of 6-months between arrival of an influenza pandemic and first availability of a vaccine. Three different pandemic scenarios were examined; mild, moderate and extreme, based on estimates of transmissibility and pathogenicity of the 2009, 1957 and 1918 influenza pandemics respectively. A range of different durations of social distancing were examined, and the sensitivity of the results to variation in the vaccination delay, ranging from 2 to 6 months, was analysed. Vaccination-only strategies were not cost effective for any pandemic scenario, saving few lives and incurring substantial vaccination costs. Vaccination coupled with long duration social distancing, antiviral treatment and antiviral prophylaxis was cost effective for moderate pandemics and extreme pandemics, where it saved lives while simultaneously reducing the total pandemic cost. Combined social distancing and antiviral interventions without vaccination were significantly less effective, since without vaccination a resurgence in case numbers occurred as soon as social distancing interventions were relaxed. When social distancing interventions were continued until at least the start of the vaccination campaign, attack rates and total costs were significantly lower, and increased rates of vaccination further improved effectiveness and cost effectiveness. The effectiveness and cost effectiveness consequences of the time-critical interplay of pandemic dynamics, vaccine availability and intervention timing has been quantified. For moderate and extreme pandemics, vaccination combined with rapidly activated antiviral and social distancing interventions of sufficient duration is cost effective from the perspective of life years saved.

A change in coral extension rates and stable isotopes after El Niño-induced coral bleaching and regional stress events

NASA Astrophysics Data System (ADS)

Hetzinger, S.; Pfeiffer, M.; Dullo, W.-Chr.; Zinke, J.; Garbe-Schönberg, D.

2016-09-01

Coral reefs are biologically diverse ecosystems threatened with effective collapse under rapid climate change, in particular by recent increases in ocean temperatures. Coral bleaching has occurred during major El Niño warming events, at times leading to the die-off of entire coral reefs. Here we present records of stable isotopic composition, Sr/Ca ratios and extension rate (1940-2004) in coral aragonite from a northern Venezuelan site, where reefs were strongly impacted by bleaching following the 1997-98 El Niño. We assess the impact of past warming events on coral extension rates and geochemical proxies. A marked decrease in coral (Pseudodiploria strigosa) extension rates coincides with a baseline shift to more negative values in oxygen and carbon isotopic composition after 1997-98, while a neighboring coral (Siderastrea siderea) recovered to pre-bleaching extension rates simultaneously. However, other stressors, besides high temperature, might also have influenced coral physiology and geochemistry. Coastal Venezuelan reefs were exposed to a series of extreme environmental fluctuations since the mid-1990s, i.e. upwelling, extreme rainfall and sediment input from landslides. This work provides important new data on the potential impacts of multiple regional stress events on coral isotopic compositions and raises questions about the long-term influence on coral-based paleoclimate reconstructions.

A change in coral extension rates and stable isotopes after El Niño-induced coral bleaching and regional stress events.

PubMed

Hetzinger, S; Pfeiffer, M; Dullo, W-Chr; Zinke, J; Garbe-Schönberg, D

2016-09-13

Coral reefs are biologically diverse ecosystems threatened with effective collapse under rapid climate change, in particular by recent increases in ocean temperatures. Coral bleaching has occurred during major El Niño warming events, at times leading to the die-off of entire coral reefs. Here we present records of stable isotopic composition, Sr/Ca ratios and extension rate (1940-2004) in coral aragonite from a northern Venezuelan site, where reefs were strongly impacted by bleaching following the 1997-98 El Niño. We assess the impact of past warming events on coral extension rates and geochemical proxies. A marked decrease in coral (Pseudodiploria strigosa) extension rates coincides with a baseline shift to more negative values in oxygen and carbon isotopic composition after 1997-98, while a neighboring coral (Siderastrea siderea) recovered to pre-bleaching extension rates simultaneously. However, other stressors, besides high temperature, might also have influenced coral physiology and geochemistry. Coastal Venezuelan reefs were exposed to a series of extreme environmental fluctuations since the mid-1990s, i.e. upwelling, extreme rainfall and sediment input from landslides. This work provides important new data on the potential impacts of multiple regional stress events on coral isotopic compositions and raises questions about the long-term influence on coral-based paleoclimate reconstructions.

Rapid Extremity Pain Relief by Battlefield Acupuncture after Orthopedic Surgery: A Randomized Clinical Trial

DTIC Science & Technology

2017-03-21

FINAL REPORT Project Title: Rapid Extremity Pain Relief by Battlefield Acupuncture after Orthopedic Surgery: A Randomized Clinical Trial...Center ATTN: DTIC-OA 8725 John J. Kingman Rd Fort Belvoir, VA 22060-6218 Submitted by: Jill M. Clark, MBA/HCM, CCRP, CCRC Senior Research ...Associate/ Research Manager Clinical Investigation Program Mike O’Callaghan Federal Medical Center (MOFMC) 4700 Las Vegas Blvd North, Bldg 1300, Room

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

Blackstone, R.; Graham, L.W.

The dimensional changes observed in a range of graphitic materials following irradiation at 600, 900, and 1200 deg C are reported. The results are discussed in the light of current models for irradiation damage in graphite and it is concluded that for conventional materials the dimensional behaviour can be related to the material properties. Further confirmation of the extreme dependence of the dimensional changes on the crystallite size has been obtained. The way in which the rate of dimensional change varies with temperature is compatible with this effect being caused by vacancy loss at crystallite boundaries. For a given crystallitemore » size there appears to be a breakaway temperature above which the rate of dimensional change accelerates rapidly. (auth)« less

Trends in the lake trout fishery of Lake Huron through 1946

USGS Publications Warehouse

Hile, Ralph

1949-01-01

The estimated abundance of lake trout in the United States waters of Lake Huron (all districts combined) had reached an extremely low level in 1946 (24 percent of the 1929–1943 average), and the complete collapse of the fishery in late years is a matter of record. The rate of decline in abundance, however, was much less rapid than the spectacular decreases in production might suggest. Although each year beginning with 1940 saw a new record low yield, the abundance was still 87 percent of average in 1942 and did not drop below 70 percent until 1944. This seeming paradox is explained by the fact that relative to average conditions, fishing intensity in 1941–1946 was lower and was decreasing much more rapidly than was abundance. PDF

Reduction of ventricular size after shunting for normal pressure hydrocephalus related to CSF dynamics before shunting.

PubMed Central

Tans, J T; Poortvliet, D C

1988-01-01

Reduction of ventricular size was determined by repeated computed tomography in 30 adult patients shunted for normal pressure hydrocephalus (NPH) and related to the pressure-volume index (PVI) and resistance to outflow of cerebrospinal fluid (Rcsf) measured before shunting. Rapid and marked reduction of ventricular size (n = 10) was associated with a significantly lower PVI than slow and moderate to marked (n = 13) or minimal to mild reduction (n = 7). Otherwise no relationship could be found between the reduction of ventricular size and PVI or Rcsf. It is concluded that both rate and magnitude of reduction of ventricular size after shunting for NPH are extremely variable. High brain elasticity seems to be the best predictor of rapid and marked reduction. PMID:3379425

The performance of spatially offset Raman spectroscopy for liquid explosive detection

NASA Astrophysics Data System (ADS)

Loeffen, Paul W.; Maskall, Guy; Bonthron, Stuart; Bloomfield, Matthew; Tombling, Craig; Matousek, Pavel

2016-10-01

Aviation security requirements adopted in 2014 require liquids to be screened at most airports throughout Europe, North America and Australia. Cobalt's unique Spatially Offset Raman Spectroscopy (SORS™) technology has proven extremely effective at screening liquids, aerosols and gels (LAGS) with extremely low false alarm rates. SORS is compatible with a wide range of containers, including coloured, opaque or clear plastics, glass and paper, as well as duty-free bottles in STEBs (secure tamper-evident bags). Our award-winning Insight range has been specially developed for table-top screening at security checkpoints. Insight systems use our patented SORS technology for rapid and accurate chemical analysis of substances in unopened non-metallic containers. Insight100M™ and the latest member of the range - Insight200M™ - also screen metallic containers. Our unique systems screen liquids, aerosols and gels with the highest detection capability and lowest false alarm rates of any ECAC-approved scanner, with several hundred units already in use at airports including eight of the top ten European hubs. This paper presents an analysis of real performance data for these systems.

Modeling of intense pulsed ion beam heated masked targets for extreme materials characterization

DOE PAGES

Barnard, John J.; Schenkel, Thomas

2017-11-15

Intense, pulsed ion beams locally heat materials and deliver dense electronic excitations that can induce material modifications and phase transitions. Material properties can potentially be stabilized by rapid quenching. Pulsed ion beams with pulse lengths of order ns have recently become available for materials processing. Here, we optimize mask geometries for local modification of materials by intense ion pulses. The goal is to rapidly excite targets volumetrically to the point where a phase transition or local lattice reconstruction is induced followed by rapid cooling that stabilizes desired material's properties fast enough before the target is altered or damaged by, e.g.,more » hydrodynamic expansion. By using a mask, the longitudinal dimension can be large compared to the transverse dimension, allowing the possibility of rapid transverse cooling. We performed HYDRA simulations that calculate peak temperatures for a series of excitation conditions and cooling rates of silicon targets with micro-structured masks and compare these to a simple analytical model. In conclusion, the model gives scaling laws that can guide the design of targets over a wide range of pulsed ion beam parameters.« less

Modeling of intense pulsed ion beam heated masked targets for extreme materials characterization

NASA Astrophysics Data System (ADS)

Barnard, John J.; Schenkel, Thomas

2017-11-01

Intense, pulsed ion beams locally heat materials and deliver dense electronic excitations that can induce material modifications and phase transitions. Material properties can potentially be stabilized by rapid quenching. Pulsed ion beams with pulse lengths of order ns have recently become available for materials processing. Here, we optimize mask geometries for local modification of materials by intense ion pulses. The goal is to rapidly excite targets volumetrically to the point where a phase transition or local lattice reconstruction is induced followed by rapid cooling that stabilizes desired material's properties fast enough before the target is altered or damaged by, e.g., hydrodynamic expansion. By using a mask, the longitudinal dimension can be large compared to the transverse dimension, allowing the possibility of rapid transverse cooling. We performed HYDRA simulations that calculate peak temperatures for a series of excitation conditions and cooling rates of silicon targets with micro-structured masks and compare these to a simple analytical model. The model gives scaling laws that can guide the design of targets over a wide range of pulsed ion beam parameters.

Practice Consolidation: Forces Not of Nature, but of Government, Demographics, Economics, and Technology.

PubMed

Edlow, Richard C

2016-01-01

The demand for healthcare services is increasing more rapidly than the supply of providers, while reimbursement levels ignore the free market law of supply and demand. The regulated healthcare environment in the United States fails to increase prices (i.e., reimbursement rates) as demand outstrips supply. Healthcare practitioners must find alternative methods in order to continue providing excellent patient care while at the same time maintaining an economically viable practice. Practice consolidation with the assistance of private equity healthcare investment is an extremely attractive solution to this imbalance.

The Current State of Head and Neck Injuries in Extreme Sports

PubMed Central

Sharma, Vinay K.; Rango, Juan; Connaughton, Alexander J.; Lombardo, Daniel J.; Sabesan, Vani J.

2015-01-01

Background: Since their conception during the mid-1970s, international participation in extreme sports has grown rapidly. The recent death of extreme snowmobiler Caleb Moore at the 2013 Winter X Games has demonstrated the serious risks associated with these sports. Purpose: To examine the incidence and prevalence of head and neck injuries (HNIs) in extreme sports. Study Design: Descriptive epidemiological study. Methods: The National Electronic Injury Surveillance System (NEISS) was used to acquire data from 7 sports (2000-2011) that were included in the Winter and Summer X Games. Data from the NEISS database were collected for each individual sport per year and type of HNI. Cumulative data for overall incidence and injuries over the entire 11-year period were calculated. National estimates were determined using NEISS-weighted calculations. Incidence rates were calculated for extreme sports using data from Outdoor Foundation Participation Reports. Results: Over 4 million injuries were reported between 2000 and 2011, of which 11.3% were HNIs. Of all HNIs, 83% were head injuries and 17% neck injuries. The 4 sports with the highest total incidence of HNI were skateboarding (129,600), snowboarding (97,527), skiing (83,313), and motocross (78,236). Severe HNI (cervical or skull fracture) accounted for 2.5% of extreme sports HNIs. Of these, skateboarding had the highest percentage of severe HNIs. Conclusion: The number of serious injuries suffered in extreme sports has increased as participation in the sports continues to grow. A greater awareness of the dangers associated with these sports offers an opportunity for sports medicine and orthopaedic physicians to advocate for safer equipment, improved on-site medical care, and further research regarding extreme sports injuries. PMID:26535369

Sclerochronology - a highly versatile tool for mariculture and reconstruction of life history traits of the queen conch, textit{Strombus gigas} (Gastropoda)

NASA Astrophysics Data System (ADS)

Radermacher, Pascal; Schöne, Bernd R.; Gischler, Eberhard; Oschmann, Wolfgang; Thébault, Julien; Fiebig, Jens

2010-05-01

The shell of the queen conch Strombus gigas provides a rapidly growing palaeoenvironmental proxy archive, allowing the detailed reconstruction of important life-history traits such as ontogeny, growth rate and growth seasonality. In this study, modern sclerochronological methods are used to cross-date the palaeotemperatures derived from the shell with local sea surface temperature (SST) records. The growth history of the shell suggests a bimodal seasonality in growth, with the growing season confined to the interval between April and November. In Glovers Reef, offshore Belize, the queen conch accreted shell carbonate at rates of up to 6 mm day-1 during the spring (April-June) and autumn (September-November). However a reduced period of growth occurred during the mid-summer months (July-August). The shell growth patterns indicate a positive response to annual seasonality with regards to precipitation. It seems likely that when precipitation levels are high, food availability is increased as the result of nutrient input to the ecosystem in correspondence with an increase in coastal runoff. Slow growth rates occur when precipitation, and as a consequence riverine runoff, is low. The SST however appears to influence growth only on a secondary level. Despite the bimodal growing season and the winter cessation in growth, the growth rates reconstructed here from two S. gigas shells are among the fastest yet reported for this species. The S. gigas specimens from Belize reached their final shell height (of 22.7 and 23.5 cm in distance between the apex and the siphonal notch) at the transition to adulthood in just 2 years. The extremely rapid growth as observed in this species permits detailed, high-resolution reconstructions of life-history traits where sub-daily resolutions can be achieved with ease. The potential for future studies has yet to be further explored. Queen conch sclerochronology provides an opportunity to recover extremely high-resolution palaeotemperature records, which could be used to improve numeric climate models, where the shells essentially function as mineralized buoys. The shell recorder may also help to reveal changes in biogeochemical dynamics in benthic ecosystems on intra-seasonal timescales in the fossil record. Furthermore, sclerochronology provides a rapid, effective and highly versatile investigative strategy when compared to time- and cost-consuming fieldwork for improving fisheries management and maricultural pursuits.

Assessing a relationship between bone microstructure and growth rate: a fluorescent labelling study in the king penguin chick (Aptenodytes patagonicus).

PubMed

de Margerie, E; Robin, J-P; Verrier, D; Cubo, J; Groscolas, R; Castanet, J

2004-02-01

Microstructure-function relationships remain poorly understood in primary bone tissues. The relationship between bone growth rate and bone tissue type, although documented in some species by previous works, remains somewhat unclear and controversial. We assessed this relationship in a species with extreme adaptations, the king penguin (Aptenodytes patagonicus). These birds have a peculiar growth, interrupted 3 months after hatching by the austral winter. Before this interruption, chicks undergo extremely rapid statural and ponderal growth. We recorded experimentally (by means of fluorescent labelling) the growth rate of bone tissue in four long bones (humerus, radius, femur and tibiotarsus) of four king penguin chicks during their fastest phase of growth (3-5 weeks after hatching) and identified the associated bone tissue types ('laminar', 'longitudinal', 'reticular' or 'radial' fibro-lamellar bone tissue). We found the highest bone tissue growth rate known to date, up to 171 microm day(-1) (mean 55 microm day(-1)). There was a highly significant relationship between bone tissue type and growth rate (P<10(-6)). Highest rates were obtained with the radial microarchitecture of fibro-lamellar bone, where cavities in the woven network are aligned radially. This result supports the heuristic value of a relationship between growth rate and bone primary microstructure. However, we also found that growth rates of bone tissue types vary according to the long bone considered (P<10(-5)) (e.g. growth rates were 38% lower in the radius than in the other long bones), a result that puts some restriction on the applicability of absolute growth rate values (e.g. to fossil species). The biomechanical disadvantages of accelerated bone growth are discussed in relation to the locomotor behaviour of the chicks during their first month of life.

Pressure-strain-rate events in homogeneous turbulent shear flow

NASA Technical Reports Server (NTRS)

Brasseur, James G.; Lee, Moon J.

1988-01-01

A detailed study of the intercomponent energy transfer processes by the pressure-strain-rate in homogeneous turbulent shear flow is presented. Probability density functions (pdf's) and contour plots of the rapid and slow pressure-strain-rate show that the energy transfer processes are extremely peaky, with high-magnitude events dominating low-magnitude fluctuations, as reflected by very high flatness factors of the pressure-strain-rate. A concept of the energy transfer class was applied to investigate details of the direction as well as magnitude of the energy transfer processes. In incompressible flow, six disjoint energy transfer classes exist. Examination of contours in instantaneous fields, pdf's and weighted pdf's of the pressure-strain-rate indicates that in the low magnitude regions all six classes play an important role, but in the high magnitude regions four classes of transfer processes, dominate. The contribution to the average slow pressure-strain-rate from the high magnitude fluctuations is only 50 percent or less. The relative significance of high and low magnitude transfer events is discussed.

On the statistical properties of viral misinformation in online social media

NASA Astrophysics Data System (ADS)

Bessi, Alessandro

2017-03-01

The massive diffusion of online social media allows for the rapid and uncontrolled spreading of conspiracy theories, hoaxes, unsubstantiated claims, and false news. Such an impressive amount of misinformation can influence policy preferences and encourage behaviors strongly divergent from recommended practices. In this paper, we study the statistical properties of viral misinformation in online social media. By means of methods belonging to Extreme Value Theory, we show that the number of extremely viral posts over time follows a homogeneous Poisson process, and that the interarrival times between such posts are independent and identically distributed, following an exponential distribution. Moreover, we characterize the uncertainty around the rate parameter of the Poisson process through Bayesian methods. Finally, we are able to derive the predictive posterior probability distribution of the number of posts exceeding a certain threshold of shares over a finite interval of time.

Crystal growth of intermetallic clathrates: Floating zone process and ultra rapid crystallization

NASA Astrophysics Data System (ADS)

Prokofiev, A.; Yan, X.; Ikeda, M.; Löffler, S.; Paschen, S.

2014-09-01

We studied the crystal growth process of type-I transition metal clathrates in two different regimes: a regime of moderate cooling rate, realized with the floating zone technique, and a regime of ultra rapid cooling, realized by the melt spinning technique. In the former regime, bulk Ba8AuxSi46-x and Ba8Cu4.8GaxGe41.2-x single crystals were grown. We investigated segregation effects of the constituting elements by measurements of the composition profiles along the growth direction. The compositional non-uniformity results in a spatial variation of the electrical resistivity which is discussed as well. Structural features of clathrates and their extremely low thermal conductivities imply specifics in growth behavior which manifest themselves most pronouncedly in a rapid crystallization process. Our melt spinning experiments on Ba8Au5Si41 and Ba8Ni3.5Si42.5 (and earlier on some other clathrates) have revealed surprisingly large grains of at least 1 μm. Because of the anomalously high growth rate of the clathrate phase the formation of impurity phases is considerably kinetically suppressed. We present our scanning and transmission electron microscopy investigations of melt spun samples and discuss structural, thermodynamic and kinetic aspects of the unusual clathrate nucleation and crystallization.

Rhabdoviruses in two species of Drosophila: vertical transmission and a recent sweep.

PubMed

Longdon, Ben; Wilfert, Lena; Obbard, Darren J; Jiggins, Francis M

2011-05-01

Insects are host to a diverse range of vertically transmitted micro-organisms, but while their bacterial symbionts are well-studied, little is known about their vertically transmitted viruses. We have found that two sigma viruses (Rhabdoviridae) recently discovered in Drosophila affinis and Drosophila obscura are both vertically transmitted. As is the case for the sigma virus of Drosophila melanogaster, we find that both males and females can transmit these viruses to their offspring. Males transmit lower viral titers through sperm than females transmit through eggs, and a lower proportion of their offspring become infected. In natural populations of D. obscura in the United Kingdom, we found that 39% of flies were infected and that the viral population shows clear evidence of a recent expansion, with extremely low genetic diversity and a large excess of rare polymorphisms. Using sequence data we estimate that the virus has swept across the United Kingdom within the past ∼11 years, during which time the viral population size doubled approximately every 9 months. Using simulations based on our lab estimates of transmission rates, we show that the biparental mode of transmission allows the virus to invade and rapidly spread through populations at rates consistent with those measured in the field. Therefore, as predicted by our simulations, the virus has undergone an extremely rapid and recent increase in population size. In light of this and earlier studies of a related virus in D. melanogaster, we conclude that vertically transmitted rhabdoviruses may be common in insects and that these host-parasite interactions can be highly dynamic.

Effect of Mn and Fe on the Formation of Fe- and Mn-Rich Intermetallics in Al–5Mg–Mn Alloys Solidified Under Near-Rapid Cooling

PubMed Central

Liu, Yulin; Huang, Gaoren; Sun, Yimeng; Zhang, Li; Huang, Zhenwei; Wang, Jijie; Liu, Chunzhong

2016-01-01

Mn was an important alloying element used in Al–Mg–Mn alloys. However, it had to be limited to a low level (<1.0 wt %) to avoid the formation of coarse intermetallics. In order to take full advantage of the benefits of Mn, research was carried out to investigate the possibility of increasing the content of Mn by studying the effect of cooling rate on the formation of Fe- and Mn-rich intermetallics at different content levels of Mn and Fe. The results indicated that in Al–5Mg–Mn alloy with low Fe content (<0.1 wt %), intermetallic Al6(Fe,Mn) was small in size and amount. With increasing Mn content, intermetallic Al6(Fe,Mn) increased, but in limited amount. In high-Fe-containing Al–5Mg–Mn alloys (0.5 wt % Fe), intermetallic Al6(Fe,Mn) became the dominant phase, even in the alloy with low Mn content (0.39 wt %). Cooling rate played a critical role in the refinement of the intermetallics. Under near-rapid cooling, intermetallic Al6(Fe,Mn) was extremely refined. Even in the high Mn and/or high-Fe-containing alloys, it still demonstrated fine Chinese script structures. However, once the alloy composition passed beyond the eutectic point, the primary intermetallic Al6(Fe,Mn) phase displayed extremely coarse platelet-like morphology. Increasing the content of Fe caused intermetallic Al6(Fe,Mn) to become the primary phase at a lower Mn content. PMID:28787888

Extremely rapid directional change during Matuyama-Brunhes geomagnetic polarity reversal

NASA Astrophysics Data System (ADS)

Sagnotti, Leonardo; Scardia, Giancarlo; Giaccio, Biagio; Liddicoat, Joseph C.; Nomade, Sebastien; Renne, Paul R.; Sprain, Courtney J.

2014-11-01

We report a palaeomagnetic investigation of the last full geomagnetic field reversal, the Matuyama-Brunhes (M-B) transition, as preserved in a continuous sequence of exposed lacustrine sediments in the Apennines of Central Italy. The palaeomagnetic record provides the most direct evidence for the tempo of transitional field behaviour yet obtained for the M-B transition. 40Ar/39Ar dating of tephra layers bracketing the M-B transition provides high-accuracy age constraints and indicates a mean sediment accumulation rate of about 0.2 mm yr-1 during the transition. Two relative palaeointensity (RPI) minima are present in the M-B transition. During the terminus of the upper RPI minimum, a directional change of about 180 ° occurred at an extremely fast rate, estimated to be less than 2 ° per year, with no intermediate virtual geomagnetic poles (VGPs) documented during the transit from the southern to northern hemisphere. Thus, the entry into the Brunhes Normal Chron as represented by the palaeomagnetic directions and VGPs developed in a time interval comparable to the duration of an average human life, which is an order of magnitude more rapid than suggested by current models. The reported investigation therefore provides high-resolution integrated palaeomagnetic and radioisotopic data that document the fine details of the anatomy and tempo of the M-B transition in Central Italy that in turn are crucial for a better understanding of Earth's magnetic field, and for the development of more sophisticated models that are able to describe its global structure and behaviour.

Aluminum/water reactions under extreme conditions

NASA Astrophysics Data System (ADS)

Hooper, Joseph

2013-03-01

We discuss mechanisms that may control the reaction of aluminum and water under extreme conditions. We are particularly interested in the high-temperature, high-strain regime where the native oxide layer is destroyed and fresh aluminum is initially in direct contact with liquid or supercritical water. Disparate experimental data over the years have suggested rapid oxidation of aluminum is possible in such situations, but no coherent picture has emerged as to the basic oxidation mechanism or the physical processes that govern the extent of reaction. We present theoretical and computational analysis of traditional metal/water reaction mechanisms that treat diffusion through a dynamic oxide layer or reaction limited by surface kinetics. Diffusion through a fresh solid oxide layer is shown to be far too slow to have any effect on the millisecond timescale (even at high temperatures). Quantum molecular dynamics simulations of liquid Al and water surface reactions show rapid water decomposition at the interface, catalyzed by adjacent water molecules in a Grotthus-like relay mechanism. The surface reaction barriers are far too low for this to be rate-limiting in any way. With these straightforward mechanisms ruled out, we investigate two more complex possibilities for the rate-limiting factor; first, we explore the possibility that newly formed oxide remains a metastable liquid well below its freezing point, allowing for diffusion-limited reactions through the oxide shell but on a much faster timescale. The extent of reaction would then be controlled by the solidification kinetics of alumina. Second, we discuss preliminary analysis on surface erosion and turbulent mixing, which may play a prominent role during hypervelocity penetration of solid aluminum projectiles into water.

Telomere dynamics in an immortal human cell line.

PubMed Central

Murnane, J P; Sabatier, L; Marder, B A; Morgan, W F

1994-01-01

The integration of transfected plasmid DNA at the telomere of chromosome 13 in an immortalized simian virus 40-transformed human cell line provided the first opportunity to study polymorphism in the number of telomeric repeat sequences on the end of a single chromosome. Three subclones of this cell line were selected for analysis: one with a long telomere on chromosome 13, one with a short telomere, and one with such extreme polymorphism that no distinct band was discernible. Further subcloning demonstrated that telomere polymorphism resulted from both gradual changes and rapid changes that sometimes involved many kilobases. The gradual changes were due to the shortening of telomeres at a rate similar to that reported for telomeres of somatic cells without telomerase, eventually resulting in the loss of nearly all of the telomere. However, telomeres were not generally lost completely, as shown by the absence of polymorphism in the subtelomeric plasmid sequences. Instead, telomeres that were less than a few hundred base pairs in length showed a rapid, highly heterogeneous increase in size. Rapid changes in telomere length also occurred on longer telomeres. The frequency of this type of change in telomere length varied among the subclones and correlated with chromosome fusion. Therefore, the rapid changes in telomere length appeared occasionally to result in the complete loss of telomeric repeat sequences. Rapid changes in telomere length have been associated with telomere loss and chromosome instability in yeast and could be responsible for the high rate of chromosome fusion observed in many human tumor cell lines. Images PMID:7957062

Work Capability and physiological effects predictive studies. 4: In He-O2 excursions to pressures of 400- 800- 1200- and 1600 feet of sea water

NASA Technical Reports Server (NTRS)

Lambertsen, C. J. (Editor); Gelfand, R. (Editor); Clark, J. M. (Editor); Fletcher, M. E. (Editor)

1978-01-01

Experiments which exposed men in chambers, breathing helium with oxygen, to progressive increases of pressure equivalent to 400-800-1200-1600 feet of sea water (fsw) were conducted. Rates of compression and exposure to stable high pressure. Goals included: 1) determination of the specific character and time course of onset of physiological and performance decrements during the intentionally rapid compressions, and determination of rates of adaptation on reaching stable elevated pressure; 2) investigation of accelerated methods for decompression in deep saturation excursion diving; and 3) determination of competence in practical work performed in water at pressures equivalent to the extreme diving depths of 1200 and 1600 fsw.

Constraining the rate of oceanic deoxygenation leading up to a Cretaceous Oceanic Anoxic Event (OAE-2: ~94 Ma)

PubMed Central

Ostrander, Chadlin M.; Owens, Jeremy D.; Nielsen, Sune G.

2017-01-01

The rates of marine deoxygenation leading to Cretaceous Oceanic Anoxic Events are poorly recognized and constrained. If increases in primary productivity are the primary driver of these episodes, progressive oxygen loss from global waters should predate enhanced carbon burial in underlying sediments—the diagnostic Oceanic Anoxic Event relic. Thallium isotope analysis of organic-rich black shales from Demerara Rise across Oceanic Anoxic Event 2 reveals evidence of expanded sediment-water interface deoxygenation ~43 ± 11 thousand years before the globally recognized carbon cycle perturbation. This evidence for rapid oxygen loss leading to an extreme ancient climatic event has timely implications for the modern ocean, which is already experiencing large-scale deoxygenation. PMID:28808684

Design and quantification of an extreme winter storm scenario for emergency preparedness and planning exercises in California

USGS Publications Warehouse

Dettinger, M.D.; Martin, Ralph F.; Hughes, M.; Das, T.; Neiman, P.; Cox, D.; Estes, G.; Reynolds, D.; Hartman, R.; Cayan, D.; Jones, L.

2012-01-01

The USGS Multihazards Project is working with numerous agencies to evaluate and plan for hazards and damages that could be caused by extreme winter storms impacting California. Atmospheric and hydrological aspects of a hypothetical storm scenario have been quantified as a basis for estimation of human, infrastructure, economic, and environmental impacts for emergency-preparedness and flood-planning exercises. In order to ensure scientific defensibility and necessary levels of detail in the scenario description, selected historical storm episodes were concatentated to describe a rapid arrival of several major storms over the state, yielding precipitation totals and runoff rates beyond those occurring during the individual historical storms. This concatenation allowed the scenario designers to avoid arbitrary scalings and is based on historical occasions from the 19th and 20th Centuries when storms have stalled over the state and when extreme storms have arrived in rapid succession. Dynamically consistent, hourly precipitation, temperatures, barometric pressures (for consideration of storm surges and coastal erosion), and winds over California were developed for the so-called ARkStorm scenario by downscaling the concatenated global records of the historical storm sequences onto 6- and 2-km grids using a regional weather model of January 1969 and February 1986 storm conditions. The weather model outputs were then used to force a hydrologic model to simulate ARkStorm runoff, to better understand resulting flooding risks. Methods used to build this scenario can be applied to other emergency, nonemergency and non-California applications. ?? 2011 The Author(s).

Accelerated modern human-induced species losses: Entering the sixth mass extinction.

PubMed

Ceballos, Gerardo; Ehrlich, Paul R; Barnosky, Anthony D; García, Andrés; Pringle, Robert M; Palmer, Todd M

2015-06-01

The oft-repeated claim that Earth's biota is entering a sixth "mass extinction" depends on clearly demonstrating that current extinction rates are far above the "background" rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing.

Accelerated modern human–induced species losses: Entering the sixth mass extinction

PubMed Central

Ceballos, Gerardo; Ehrlich, Paul R.; Barnosky, Anthony D.; García, Andrés; Pringle, Robert M.; Palmer, Todd M.

2015-01-01

The oft-repeated claim that Earth’s biota is entering a sixth “mass extinction” depends on clearly demonstrating that current extinction rates are far above the “background” rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing. PMID:26601195

Rapid shifts in South American montane climates driven by pCO2 and ice volume changes over the last two glacial cycles

NASA Astrophysics Data System (ADS)

Groot, M. H. M.; Bogotá, R. G.; Lourens, L. J.; Hooghiemstra, H.; Vriend, M.; Berrio, J. C.; Tuenter, E.; van der Plicht, J.; van Geel, B.; Ziegler, M.; Weber, S. L.; Betancourt, A.; Contreras, L.; Gaviria, S.; Giraldo, C.; González, N.; Jansen, J. H. F.; Konert, M.; Ortega, D.; Rangel, O.; Sarmiento, G.; Vandenberghe, J.; van der Hammen, T.; van der Linden, M.; Westerhoff, W.

2010-10-01

Tropical montane biome migration patterns in the northern Andes are found to be coupled to glacial-induced mean annual temperature (MAT) changes; however, the accuracy and resolution of current records are insufficient to fully explore their magnitude and rates of change. Here we present a ~60-year resolution pollen record over the past 284 000 years from Lake Fúquene (5° N) in Colombia. This record shows rapid and extreme MAT changes at 2540 m elevation of up to 10 ± 2 °C within a few hundred of years that concur with the ~100 and 41-kyr (obliquity) paced glacial cycles and North Atlantic abrupt climatic events as documented in ice cores and marine sediments. Using transient climate modelling experiments we demonstrate that insolation-controlled ice volume and greenhouse gasses are the major forcing agents causing the orbital MAT changes, but that the model simulations significantly underestimate changes in lapse rates and local hydrology and vegetation feedbacks within the studied region due to its low spatial resolution.

Increasing precipitation volatility in twenty-first-century California

NASA Astrophysics Data System (ADS)

Swain, Daniel L.; Langenbrunner, Baird; Neelin, J. David; Hall, Alex

2018-05-01

Mediterranean climate regimes are particularly susceptible to rapid shifts between drought and flood—of which, California's rapid transition from record multi-year dryness between 2012 and 2016 to extreme wetness during the 2016-2017 winter provides a dramatic example. Projected future changes in such dry-to-wet events, however, remain inadequately quantified, which we investigate here using the Community Earth System Model Large Ensemble of climate model simulations. Anthropogenic forcing is found to yield large twenty-first-century increases in the frequency of wet extremes, including a more than threefold increase in sub-seasonal events comparable to California's `Great Flood of 1862'. Smaller but statistically robust increases in dry extremes are also apparent. As a consequence, a 25% to 100% increase in extreme dry-to-wet precipitation events is projected, despite only modest changes in mean precipitation. Such hydrological cycle intensification would seriously challenge California's existing water storage, conveyance and flood control infrastructure.

Impact of an extreme climatic event on community assembly.

PubMed

Thibault, Katherine M; Brown, James H

2008-03-04

Extreme climatic events are predicted to increase in frequency and magnitude, but their ecological impacts are poorly understood. Such events are large, infrequent, stochastic perturbations that can change the outcome of entrained ecological processes. Here we show how an extreme flood event affected a desert rodent community that has been monitored for 30 years. The flood (i) caused catastrophic, species-specific mortality; (ii) eliminated the incumbency advantage of previously dominant species; (iii) reset long-term population and community trends; (iv) interacted with competitive and metapopulation dynamics; and (v) resulted in rapid, wholesale reorganization of the community. This and a previous extreme rainfall event were punctuational perturbations-they caused large, rapid population- and community-level changes that were superimposed on a background of more gradual trends driven by climate and vegetation change. Captured by chance through long-term monitoring, the impacts of such large, infrequent events provide unique insights into the processes that structure ecological communities.

The Goldilocks Principle and Rapid Evolution of Antibiotic Resistance in Bacteria

NASA Astrophysics Data System (ADS)

Zhang, Qiucen; Austin, Robert

2011-03-01

Goldilocks sampled the three bear's wares for the ``just right'' combination of taste, fit and comfort. Like Goldilocks's need for the just right parameters, evolution proceeds most rapidly when there is the just right combination of a large number of mutants and rapid fixation of the mutants. We show here using a two-dimensional micro-ecology that it is possible to fix resistance to the powerful antibiotic ciprofloxacin (Cipro) in wild-type E. coli in 10 hours through a combination of extremely high population gradients, which generate rapid fixation, convolved with the just right level of antibiotic which generates a large number of mutants and the motility of the organism. Although evolution occurs in well-stirred chemostats without such Goldilocks conditions, natural environments are rarely well stirred in nature.For complex environments such as the Galapagos Islands, spatial population gradients and movement of mutants along these population gradients can be as important as genomic heterogeneity in setting the speed of evolution. The design of our micro-ecology is unique in that it provides two overlapping gradients, one an emergent and self generated bacterial population gradient due to food restriction and the other a mutagenic antibiotic gradient. Further, it exploits the motility of the bacteria moving across these gradients to drive the rate of resistance to Cipro to extraordinarily high rates. The research described was supported by Award Number U54CA143803 from the National Cancer Institute.

Formation and fate of sedimentary depocentres on Southeast Asia's Sunda Shelf over the past sea-level cycle and biogeographic implications

NASA Astrophysics Data System (ADS)

Hanebuth, Till J. J.; Voris, Harold K.; Yokoyama, Yusuke; Saito, Yoshiki; Okuno, Jun'ichi

2011-01-01

Sea-level variations are the major factor controlling sedimentation as well as the biogeographic patterns at continental margins over late Quaternary times. Fluctuations on millennial time-scales produce locally complex deposits in coasts and on shelves, associated with short-term influence on species development. This article reviews the sedimentary and biogeographic history of the tropical siliciclastic Sunda Shelf as an end-member of continental shelves regarding extreme width, an enormous sediment supply, and highest biodiversity in response to rapid sea-level fluctuations. We describe particular depositional segments as part of a genetic succession of zones from land to the deep sea based on literature data, field observations, and calculation of hydro-isostatic adjustment effects on changing relative sea level. These segments are characterized by individual sedimentary processes and deposits, and by a specific potential for material storage and re-mobilization. Long-term regressive intervals led to overall sigmoidal-promoting, extremely thick, and wide succeeding units. In contrast, rapid lateral shifts of defined depocentres over long distances took place in response to short-term sea level fluctuations. Fully isolated small-scale sediment bodies formed when sea level changed at exceptionally high rates. As a result of the high availability of organic-rich sediments, mangrove and freshwater peats formed frequently over late Quaternary times. The appearance of thick, massive and widespread peats is mainly linked to time intervals of a sea-level rise at slow rates, whilst organic matter appears much more dispersely in the sediments during episodes of rapidly changing sea level. The preservation potential of the regressive units is generally high due to highest initial sediment supply, stabilizing soil formation during exposure and rapid subsidence. Preservation of depositional elements from other periods is more exceptional and either restricted to local morphological depressions or to episodes of rapid sea level change. Besides complex channel incision, an overall lowering of the sediment surface related to erosion, as deep as 20 m or more, over wide areas took place mainly during sea level lowering. The final export of shelf material is documented by enormous mass-wasting packages on the associated continental slope. From a palaeogeographic perspective, the rapid formation or disappearance of special habitat zones, such as mangrove fringes and extended mud flats, led to species establishment or truncation in distribution. In addition, the opening or closure of ocean passages, as narrow bridges allowing limited species crossing or as fully colonized corridors, had severe impact on eco-fragmentation and the expansion or contraction of species. Independent of such particular conditions, sea-level changes have been too rapid over the past climatic cycle to allow full regeneration and mature development of coast-related ecosystems.

Biodiversity increases the resistance of ecosystem productivity to climate extremes

USDA-ARS?s Scientific Manuscript database

It remains unclear whether biodiversity buffers ecosystems against extreme climate events, which are becoming increasingly frequent worldwide. Although early results suggested that biodiversity might provide both resistance and resilience (sensu rapid recovery) of ecosystem productivity to drought, ...

Multigrid preconditioned conjugate-gradient method for large-scale wave-front reconstruction.

PubMed

Gilles, Luc; Vogel, Curtis R; Ellerbroek, Brent L

2002-09-01

We introduce a multigrid preconditioned conjugate-gradient (MGCG) iterative scheme for computing open-loop wave-front reconstructors for extreme adaptive optics systems. We present numerical simulations for a 17-m class telescope with n = 48756 sensor measurement grid points within the aperture, which indicate that our MGCG method has a rapid convergence rate for a wide range of subaperture average slope measurement signal-to-noise ratios. The total computational cost is of order n log n. Hence our scheme provides for fast wave-front simulation and control in large-scale adaptive optics systems.

The Need for Optical Means as an Alternative for Electronic Computing

NASA Technical Reports Server (NTRS)

Adbeldayem, Hossin; Frazier, Donald; Witherow, William; Paley, Steve; Penn, Benjamin; Bank, Curtis; Whitaker, Ann F. (Technical Monitor)

2001-01-01

An increasing demand for faster computers is rapidly growing to encounter the fast growing rate of Internet, space communication, and robotic industry. Unfortunately, the Very Large Scale Integration technology is approaching its fundamental limits beyond which the device will be unreliable. Optical interconnections and optical integrated circuits are strongly believed to provide the way out of the extreme limitations imposed on the growth of speed and complexity of nowadays computations by conventional electronics. This paper demonstrates two ultra-fast, all-optical logic gates and a high-density storage medium, which are essential components in building the future optical computer.

Effectiveness of using thyrocalcitonin for the prevention of a calcium metabolic disorder in the mineralized tissues of rabbits with 30 days hypokinesia

NASA Technical Reports Server (NTRS)

Volozhin, A. I.; Shashkov, V. S.; Dmitriyev, B. S.; Yegorov, B. B.; Lobachik, V. I.; Brishin, A. I.

1980-01-01

A 30 day hypokinesia in rabbits led to a considerable lag in weight gain for the skeletal bones, reduction in Ca45 uptake, and an increase in isotope resorption rate in the rapidly metabolized fraction of extremity bones. On the other hand, Ca45 content in the teeth and maxillae increased, which may be explained by redistribution of isotope among the various mineralized tissues. Injection of thyrocalcitonin (50 IU/day) produced a distinct normalizing effect on Ca45 uptake and resorption in the mineralized tissues of rabbits kept hypokinetic.

Tropical vegetation evidence for rapid sea level changes associated with Heinrich Events

NASA Astrophysics Data System (ADS)

González, Catalina; Dupont, Lydie M.

2010-03-01

A Cariaco Basin pollen record shows the development of tropical salt marshes during marine isotope stage 3. Rapid and abrupt expansions of salt marsh vegetation in tropical South America are associated with north Atlantic Heinrich Events stadials (HE-stadials). Intervals of salt marsh expansion have an internal structure, which consists of a recurrent alternation of species that starts with pollen increments of Chenopodiaceae, that are followed by increments of grasses, and subsequently by increments of Cyperaceae. This pattern suggests a successional process that is determined by the close relationship between sea-level and plant community dynamics. The salt tolerant Chenopodiaceae, indicate hypersaline intertidal environments, which were most likely promoted by extremely dry atmospheric conditions. Rapid sea-level rise characterizes the onset of HE-stadials, causing the continued recruitment of pioneer species, which are the only ones tolerating rapid rates of disturbance. Once sea-level rise decelerates, marsh plants are able to trap and stabilize sediments, favouring the establishment of more competitive species. These results add to the scarce knowledge on the dynamics of tropical salt marsh ecosystems, and provide independent paleoclimatic evidence on sea-level changes following Antarctic climate variability.

Crystal Thermoelasticity at Extreme Loading Rates and Pressures: Analysis of Higher-Order Energy Potentials

DTIC Science & Technology

2015-07-01

ARL-RP-0526 ● JULY 2015 US Army Research Laboratory Crystal Thermoelasticity at Extreme Loading Rates and Pressures : Analysis of...ARL-RP-0526 ● JULY 2015 US Army Research Laboratory Crystal Thermoelasticity at Extreme Loading Rates and Pressures : Analysis of...2015 4. TITLE AND SUBTITLE Crystal Thermoelasticity at Extreme Loading Rates and Pressures : Analysis of Higher-Order Energy Potentials 5a. CONTRACT

Submarine landslide and tsunami hazards offshore southern Alaska: Seismic strengthening versus rapid sedimentation

NASA Astrophysics Data System (ADS)

Sawyer, Derek E.; Reece, Robert S.; Gulick, Sean P. S.; Lenz, Brandi L.

2017-08-01

The southern Alaskan offshore margin is prone to submarine landslides and tsunami hazards due to seismically active plate boundaries and extreme sedimentation rates from glacially enhanced mountain erosion. We examine the submarine landslide potential with new shear strength measurements acquired by Integrated Ocean Drilling Program Expedition 341 on the continental slope and Surveyor Fan. These data reveal lower than expected sediment strength. Contrary to other active margins where seismic strengthening enhances slope stability, the high-sedimentation margin offshore southern Alaska behaves like a passive margin from a shear strength perspective. We interpret that seismic strengthening occurs but is offset by high sedimentation rates and overpressure. This conclusion is supported by shear strength outside of the fan that follow an active margin trend. More broadly, seismically active margins with wet-based glaciers are susceptible to submarine landslide hazards because of the combination of high sedimentation rates and earthquake shaking.

Increasing potential for intense tropical and subtropical thunderstorms under global warming.

PubMed

Singh, Martin S; Kuang, Zhiming; Maloney, Eric D; Hannah, Walter M; Wolding, Brandon O

2017-10-31

Intense thunderstorms produce rapid cloud updrafts and may be associated with a range of destructive weather events. An important ingredient in measures of the potential for intense thunderstorms is the convective available potential energy (CAPE). Climate models project increases in summertime mean CAPE in the tropics and subtropics in response to global warming, but the physical mechanisms responsible for such increases and the implications for future thunderstorm activity remain uncertain. Here, we show that high percentiles of the CAPE distribution (CAPE extremes) also increase robustly with warming across the tropics and subtropics in an ensemble of state-of-the-art climate models, implying strong increases in the frequency of occurrence of environments conducive to intense thunderstorms in future climate projections. The increase in CAPE extremes is consistent with a recently proposed theoretical model in which CAPE depends on the influence of convective entrainment on the tropospheric lapse rate, and we demonstrate the importance of this influence for simulated CAPE extremes using a climate model in which the convective entrainment rate is varied. We further show that the theoretical model is able to account for the climatological relationship between CAPE and a measure of lower-tropospheric humidity in simulations and in observations. Our results provide a physical basis on which to understand projected future increases in intense thunderstorm potential, and they suggest that an important mechanism that contributes to such increases may be present in Earth's atmosphere. Published under the PNAS license.

Increasing potential for intense tropical and subtropical thunderstorms under global warming

PubMed Central

Kuang, Zhiming; Maloney, Eric D.; Hannah, Walter M.; Wolding, Brandon O.

2017-01-01

Intense thunderstorms produce rapid cloud updrafts and may be associated with a range of destructive weather events. An important ingredient in measures of the potential for intense thunderstorms is the convective available potential energy (CAPE). Climate models project increases in summertime mean CAPE in the tropics and subtropics in response to global warming, but the physical mechanisms responsible for such increases and the implications for future thunderstorm activity remain uncertain. Here, we show that high percentiles of the CAPE distribution (CAPE extremes) also increase robustly with warming across the tropics and subtropics in an ensemble of state-of-the-art climate models, implying strong increases in the frequency of occurrence of environments conducive to intense thunderstorms in future climate projections. The increase in CAPE extremes is consistent with a recently proposed theoretical model in which CAPE depends on the influence of convective entrainment on the tropospheric lapse rate, and we demonstrate the importance of this influence for simulated CAPE extremes using a climate model in which the convective entrainment rate is varied. We further show that the theoretical model is able to account for the climatological relationship between CAPE and a measure of lower-tropospheric humidity in simulations and in observations. Our results provide a physical basis on which to understand projected future increases in intense thunderstorm potential, and they suggest that an important mechanism that contributes to such increases may be present in Earth’s atmosphere. PMID:29078312

Extreme limestone weathering rates due to micron-scale grain detachment

NASA Astrophysics Data System (ADS)

Emmanuel, Simon; Levenson, Yael

2014-05-01

Chemical dissolution is often assumed to control the weathering rates of carbonate rocks, although some studies have indicated that mechanical erosion could also play a significant role. Quantifying the rates of the different processes is challenging due to the high degree of variability encountered in both field and lab settings. To measure the rates and mechanisms controlling long-term limestone weathering, we analyse a lidar scan of the Western Wall, a Roman period edifice located in Jerusalem. Surface retreat rates in fine-grained micritic limestone blocks are found to be as much as 2 orders of magnitude higher than the average rates estimated for coarse-grained limestone blocks at the same site. In addition, in experiments that use atomic force microscopy to image dissolving micritic limestone, we show that these elevated reaction rates could be due to rapid dissolution along micron-scale grain boundaries, followed by mechanical detachment of tiny particles from the surface. Our analysis indicates that micron-scale grain detachment, rather than pure chemical dissolution, could be the dominant erosional mode for fine-grained carbonate rocks.

Founder effects initiated rapid species radiation in Hawaiian cave planthoppers

PubMed Central

Wessel, Andreas; Hoch, Hannelore; Asche, Manfred; von Rintelen, Thomas; Stelbrink, Björn; Heck, Volker; Stone, Fred D.; Howarth, Francis G.

2013-01-01

The Hawaiian Islands provide the venue of one of nature’s grand experiments in evolution. Here, we present morphological, behavioral, genetic, and geologic data from a young subterranean insect lineage in lava tube caves on Hawai‘i Island. The Oliarus polyphemus species complex has the potential to become a model for studying rapid speciation by stochastic events. All species in this lineage live in extremely similar environments but show strong differentiation in behavioral and morphometric characters, which are random with respect to cave age and geographic distribution. Our observation that phenotypic variability within populations decreases with increasing cave age challenges traditional views on founder effects. Furthermore, these cave populations are natural replicates that can be used to test the contradictory hypotheses. Moreover, Hawaiian cave planthoppers exhibit one of the highest speciation rates among animals and, thus, radically shift our perception on the evolutionary potential of obligate cavernicoles. PMID:23696661

Rapid Fabrication of Lightweight SiC Optics using Reactive Atom Plasma (RAP) Processing

NASA Technical Reports Server (NTRS)

Fiske, Peter S.

2006-01-01

Reactive Atom Plasma (RAP) processing is a non-contact, plasma-based processing technology that can be used to generate damage-free optical surfaces. We have developed tools and processes using RAP that allow us to shape extremely lightweight mirror Surfaces made from extremely hard-to-machine materials (e.g. SiC). We will describe our latest results using RAP in combination with other technologies to produce finished lightweight SiC mirrors and also discuss applications for RAP in the rapid fabrication of mirror segments for reflective and grazing incidence telescopes.

Preservation of cognitive and functional ability as markers of longevity.

PubMed

Schupf, Nicole; Costa, Rosann; Tang, Ming-Xin; Andrews, Howard; Tycko, Benjamin; Lee, Joseph H; Mayeux, Richard

2004-10-01

Longevity is a complex biological process for which the phenotypes have not been established. Preservation of cognitive and physical function may be important and preservation of these functions is, in part, inherited. We investigated the relation between rate of change in cognitive and functional abilities in probands and risk of death in their siblings. Probands were classified as showing no decline, slow, medium, or rapid rate of decline, based on the slope of change in cognitive and physical/functional factors over three or more assessments. Siblings of probands who did not decline on measures of memory, visuospatial/cognitive function or ADL skills were approximately half as likely to die as siblings of probands who had the most rapid decline. The reduction in risk of death in siblings of probands who did not decline in was primarily observed among siblings of probands who were older than 75 years, suggesting that genetic influences on life span may be greater at older ages. There was no association between probands' rate of change in language, IADL skills, upper or lower extremity mobility and risk of death in siblings. The results of the present study identify phenotypes associated with preserved cognitive and functional abilities which may serve as markers for longevity.

Discovery of rapid whistlers close to Jupiter implying lightning rates similar to those on Earth

NASA Astrophysics Data System (ADS)

Kolmašová, Ivana; Imai, Masafumi; Santolík, Ondřej; Kurth, William S.; Hospodarsky, George B.; Gurnett, Donald A.; Connerney, John E. P.; Bolton, Scott J.

2018-06-01

Electrical currents in atmospheric lightning strokes generate impulsive radio waves in a broad range of frequencies, called atmospherics. These waves can be modified by their passage through the plasma environment of a planet into the form of dispersed whistlers1. In the Io plasma torus around Jupiter, Voyager 1 detected whistlers as several-seconds-long slowly falling tones at audible frequencies2. These measurements were the first evidence of lightning at Jupiter. Subsequently, Jovian lightning was observed by optical cameras on board several spacecraft in the form of localized flashes of light3-7. Here, we show measurements by the Waves instrument8 on board the Juno spacecraft9-11 that indicate observations of Jovian rapid whistlers: a form of dispersed atmospherics at extremely short timescales of several milliseconds to several tens of milliseconds. On the basis of these measurements, we report over 1,600 lightning detections, the largest set obtained to date. The data were acquired during close approaches to Jupiter between August 2016 and September 2017, at radial distances below 5 Jovian radii. We detected up to four lightning strokes per second, similar to rates in thunderstorms on Earth12 and six times the peak rates from the Voyager 1 observations13.

Human Tolerance to Rapidly Applied Accelerations: A Summary of the Literature

NASA Technical Reports Server (NTRS)

Eiband, A. Martin

1959-01-01

The literature is surveyed to determine human tolerance to rapidly applied accelerations. Pertinent human and animal experiments applicable to space flight and to crash impact forces are analyzed and discussed. These data are compared and presented on the basis of a trapezoidal pulse. The effects of body restraint and of acceleration direction, onset rate, and plateau duration on the maximum tolerable and survivable rapidly applied accelerations are shown. Results of the survey indicate that adequate torso and extremity restraint is the primary variable in tolerance to rapidly applied accelerations. The harness, or restraint system, must be arranged to transmit the major portion of the accelerating force directly to the pelvic structure and not via the vertebral column. When the conditions of adequate restraint have been met, then the other variables, direction, magnitude, and onset rate of rapidly applied accelerations, govern maximum tolerance and injury limits. The results also indicate that adequately stressed aft-faced passenger seats offer maximum complete body support with minimum objectionable harnessing. Such a seat, whether designed for 20-, 30-, or 40-G dynamic loading, would include lap strap, chest (axillary) strap, and winged-back seat to increase headward and lateral G protection, full-height integral head rest, arm rests (load-bearing) with recessed hand-holds and provisions to prevent arms from slipping either laterally or beyond the seat back, and leg support to keep the legs from being wedged under the seat. For crew members and others whose duties require forward-facing seats, maximum complete body support requires lap, shoulder, and thigh straps, lap-belt tie-down strap, and full-height seat back with integral head support.

Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments

NASA Astrophysics Data System (ADS)

Sun, C.; Zheng, S.; Wei, C. C.; Wu, Y.; Shao, L.; Yang, Y.; Hartwig, K. T.; Maloy, S. A.; Zinkle, S. J.; Allen, T. R.; Wang, H.; Zhang, X.

2015-01-01

Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500°C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M23C6 precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.

Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments

DOE PAGES

Sun, C.; Zheng, S.; Wei, C. C.; ...

2015-01-15

Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304L SS with an average grain size ofmore » ~100 nm, can withstand Fe ion irradiation at 500°C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M₂₃C₆ precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.« less

Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments.

PubMed

Sun, C; Zheng, S; Wei, C C; Wu, Y; Shao, L; Yang, Y; Hartwig, K T; Maloy, S A; Zinkle, S J; Allen, T R; Wang, H; Zhang, X

2015-01-15

Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304 L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500 °C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M(23)C(6) precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.

Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments

PubMed Central

Sun, C.; Zheng, S.; Wei, C. C.; Wu, Y.; Shao, L.; Yang, Y.; Hartwig, K. T.; Maloy, S. A.; Zinkle, S. J.; Allen, T. R.; Wang, H.; Zhang, X.

2015-01-01

Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500°C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M23C6 precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments. PMID:25588326

Oral bioavailability enhancement of β-lapachone, a poorly soluble fast crystallizer, by cocrystal, amorphous solid dispersion, and crystalline solid dispersion.

PubMed

Liu, Chengyu; Liu, Zhengsheng; Chen, Yuejie; Chen, Zhen; Chen, Huijun; Pui, Yipshu; Qian, Feng

2018-03-01

The aim of this paper was to compare the in vitro dissolution and in vivo bioavailability of three solubility enhancement technologies for β-lapachone (LPC), a poorly water soluble compound with extremely high crystallization propensity. LPC cocrystal was prepared by co-grinding LPC with resorcinol. LPC crystalline and amorphous solid dispersions (CSD and ASD) were obtained by spray drying with Poloxamer 188 and HPMC-AS, respectively. The cocrystal structure was solved by single crystal x-ray diffraction. All formulations were characterized by WAXRD, DSC, POM and SEM. USP II and intrinsic dissolution studies were used to compare the in vitro dissolution of these formulations, and a crossover dog pharmacokinetic study was used to compare their in vivo bioavailability. An 1:1 LPC-resorcinol cocrystal with higher solubility and faster dissolution rate was obtained, yet it converted to LPC crystal rapidly in solution. LPC/HPMC-AS ASD was confirmed to be amorphous and uniform, while the crystal and crystallite sizes of LPC in CSD were found to be ∼1-3 μm and around 40 nm, respectively. These formulations performed similarly during USP II dissolution, while demonstrated dramatically different oral bioavailability of ∼32%, ∼5%, and ∼1% in dogs, for CSD, co-crystal, and ASD, respectively. CSD showed the fastest intrinsic dissolution rate among the three. The three formulations showed poor IVIVC which could be due to rapid and unpredictable crystallization kinetics. Considering all the reasons, we conclude that for molecules with extremely high crystallization tendency that cannot be inhibited by any pharmaceutical excipients, size-reduction technologies such as CSD could be advantageous for oral bioavailability enhancement in vivo than technologies only generating transient but not sustained supersaturation. Copyright © 2018 Elsevier B.V. All rights reserved.

Weathering, erosion and fluvial transfers of particulate and dissolved materials from the Taiwan orogen

NASA Astrophysics Data System (ADS)

Hovius, Niels; Galy, Albert; Hilton, Robert; West, Joshua; Chen, Hongey; Horng, Ming-Jame; Chen, Meng-Chiang

2010-05-01

Systematic monitoring of river loads helps refine and extend the map of internal dynamics and external feedbacks in Earth's surface and near-surface system. Our focus is on Taiwan where hillslope mass wasting and fluvial sediment transport are driven by earthquakes and cyclonic storms. The biggest trigger events cause instantaneous erosion and seed a weakness in the landscape that is removed over time in predictable fashion. This gives rise to patterns of erosion that can not be understood in terms of bulk characteristics of climate, such as average annual precipitation. Instead, these patterns reflect the distribution and history of seismicity and extreme precipitation. For example, the 1999 Mw 7.6 Chi-Chi earthquake has resulted in elevated rates of sediment transport that decayed to normal values over seven years since the earthquake. Very large typhoons, with enhanced precipitation due to a monsoonal feed, have caused a similar, temporary deviation from normal catchment dynamics. Crucially, these events do not only mobilize large quantities of clastic sediment, but they also harvest particulate organic carbon (POC) from rock mass, soils and the biosphere. In Taiwan, most non-fossil POC is carried in hyperpycnal storm floods. This may promote rapid burial and preservation of POC in turbidites, representing a draw down of CO2 from the atmosphere that is potentially larger than that by silicate weathering in the same domain. Oxidation of fossil POC during exhumation and surface transport could offset this effect, but in Taiwan the rate of preservation of fossil POC is extremely high, due to rapid erosion and short fluvial transfer paths. Meanwhile, coarse woody debris flushed from the Taiwan mountains is probably not buried efficiently in geological deposits, representing a concentrated flux of nutrients to coastal and marine environments instead.

Late-Quaternary Exhumation of Namche Barwa Constrained Using Low-temperature Multi-OSL-thermochronometry

NASA Astrophysics Data System (ADS)

King, G. E.; Herman, F.

2015-12-01

Exhumation rates >5 mm a-1 have been reported for Namche Barwa, making it one of the most rapidly exhuming places on earth. The driver of such high exhumation rates has been highly debated, and two principle hypotheses have evolved: first the aneurysm model (Zeitler et al., 2001) which proposes that a weakening of the crust coupled with extremely active surface processes causes a spatially stationary locus of exhumation. Secondly a northward plunging antiform that is progressively migrating north-eastward (Seward and Burg, 2008) may instead explain the concentration of extremely low cooling ages and rapid exhumation. Distinguishing the effects of tectonic and surface processes, as well as climate is complex, especially given that most existing thermochronometric systems are unable to resolve late-stage cooling histories. Here we present multi-OSL-thermochronometry which comprises a series of different systems with closure temperature ranging from 30 to 70 oC. We have applied this new technique to a suite of samples from the Namche Barwa massif and are able to resolve cooling histories over 0.1 Ma timescales. Our data indicate propagation of a knick-point along the Parlung river, which can be explained by progressive north-eastward migration of a northward plunging antiform. We suggest therefore that river incision does not feedback onto tectonics, as proposed by the aneurysm model. References Seward, D., Burg, J-P., 2008. Growth of the Namche Barwa Syntaxis and associated evolution of the Tsangpo Gorge: Constraints from structural and thermochronological data. Tectonophysics 451, 282-289. Zeitler, P.K., Meltzer, A.S., Koons, P.O., et al., 2001. Erosion, Himalayan Geodynamics, and the Geomorphology of Metamorphism. GSA Today 11, 4-9.

Gait pattern alteration by functional sensory substitution in healthy subjects and in diabetic subjects with peripheral neuropathy.

PubMed

Walker, S C; Helm, P A; Lavery, L A

1997-08-01

To evaluate the ability of diabetic and nondiabetic individuals to learn to use a lower extremity sensory substitution device to cue gait pattern changes. Case-control study. Gait laboratory. Thirty diabetic persons and 20 age- and education-matched nondiabetic controls responded to advertisements for study participation. Participants walked on a treadmill at three speeds (1, 2, and 2.5mph) with auditory sensory feedback to cue ground contact greater than 80% duration of baseline. The variables measured included gait cycle (steps per minute) and number of times per minute that any step during a trial exceeded 80% duration of ground contacted compared with a measured baseline step length for each speed. Persons in both groups were able to rapidly and significantly alter their gait patterns in response to signals from the sensory substitution device, by changing their gait cycles (nondiabetic group, F(17,124) = 5.27, p < .001; diabetic group, F(5,172) = 3.45, p < .001). Post hoc analyses showed early gait cycle modification and error reduction among both groups. The nondiabetic group learned to use the device significantly more quickly than the diabetic group during the slow (1mph, t = 3.57, p < .001) and average (2mph, t = 2.97, p < .05) trials. By the fast (2.5mph) ambulation trial, both groups were performing equally, suggesting a rapid rate of adjustment to the device. No technical failures from gait trainer malfunction occurred during the study. Diabetic persons with neuropathy effectively used lower extremity sensory substitution, and the technology is now available to manufacture a durable, effective lower extremity sensory substitution system.

The Dynamics of Rapidly Emplaced Terrestrial Lava Flows and Implications for Planetary Volcanism

NASA Technical Reports Server (NTRS)

Baloga, Stephen; Spudis, Paul D.; Guest, John E.

1995-01-01

The Kaupulehu 1800-1801 lava flow of Hualalai volcano and the 1823 Keaiwa flow from the Great Crack of the Kilauea southwest rift zone had certain unusual and possibly unique properties for terrestrial basaltic lava flows. Both flows apparently had very low viscosities, high effusion rates, and uncommonly rapid rates of advance. Ultramafic xenolith nodules in the 1801 flow form stacks of cobbles with lava rinds of only millimeter thicknesses. The velocity of the lava stream in the 1801 flow was extremely high, at least 10 m/s (more than 40 km/h). Observations and geological evidence suggest similarly high velocities for the 1823 flow. The unusual eruption conditions that produced these lava flows suggest a floodlike mode of emplacement unlike that of most other present-day flows. Although considerable effort has gone into understanding the viscous fluid dynamics and thermal processes that often occur in basaltic flows, the unusual conditions prevalent for the Kaupulehu and Keaiwa flows necessitate different modeling considerations. We propose an elementary flood model for this type of lava emplacement and show that it produces consistent agreement with the overall dimensions of the flow, channel sizes, and other supporting field evidence. The reconstructed dynamics of these rapidly emplaced terrestrial lava flows provide significant insights about the nature of these eruptions and their analogs in planetary volcanism.

Spurious behavior in volcanic records of geomagnetic field reversals

NASA Astrophysics Data System (ADS)

Carlut, Julie; Vella, Jerome; Valet, Jean-Pierre; Soler, Vicente; Legoff, Maxime

2016-04-01

Very large directional variations of magnetization have been reported in several lava flows recording a geomagnetic reversal. Such behavior could reflect real geomagnetic changes or be caused by artifacts due to post-emplacement alteration and/or non-ideal magnetic behavior. More recently, a high resolution paleomagnetic record from sediments pleads also for an extremely rapid reversal process during the last reversal. Assuming that the geomagnetic field would have moved by tens of degrees during cooling of moderate thickness lava flows implies brief episodes of rapid changes by a few degrees per day that are difficult to reconcile with the rate of liquid motions at the core surface. Systematical mineralogical bias is a most likely explanation to promote such behavior as recently reconsidered by Coe et al., 2014 for the rapid field changes recorded at Steens Mountain. We resampled three lava flows at La Palma island (Canarias) that are sandwiched between reverse polarity and normal polarity flows associated with the last reversal. The results show an evolution of the magnetization direction from top to bottom. Thermal demagnetization experiments were conducted using different heating and cooling rates. Similarly, continuous demagnetization and measurements. In both cases, we did not notice any remagnetization associated with mineralogical transformations during the experiments. Magnetic grain sizes do not show any correlation with the amplitude of the deviations. Microscopic observations indicate poor exsolution, which could suggests post-cooling thermochemical remagnetization processes.

Robust increase in extreme summer rainfall intensity during the past four decades observed in China

NASA Astrophysics Data System (ADS)

Xiao, Chan; Wu, Peili; Zhang, Lixia; Song, Lianchun

2016-12-01

Global warming increases the moisture holding capacity of the atmosphere and consequently the potential risks of extreme rainfall. Here we show that maximum hourly summer rainfall intensity has increased by about 11.2% on average, using continuous hourly gauge records for 1971-2013 from 721 weather stations in China. The corresponding event accumulated precipitation has on average increased by more than 10% aided by a small positive trend in events duration. Linear regression of the 95th percentile daily precipitation intensity with daily mean surface air temperature shows a negative scaling of -9.6%/K, in contrast to a positive scaling of 10.6%/K for hourly data. This is made up of a positive scaling below the summer mean temperature and a negative scaling above. Using seasonal means instead of daily means, we find a consistent scaling rate for the region of 6.7-7%/K for both daily and hourly precipitation extremes, about 10% higher than the regional Clausius-Clapeyron scaling of 6.1%/K based on a mean temperature of 24.6 °C. With up to 18% further increase in extreme precipitation under continuing global warming towards the IPCC’s 1.5 °C target, risks of flash floods will exacerbate on top of the current incapability of urban drainage systems in a rapidly urbanizing China.

Winter storms drive rapid phenotypic, regulatory, and genomic shifts in the green anole lizard.

PubMed

Campbell-Staton, Shane C; Cheviron, Zachary A; Rochette, Nicholas; Catchen, Julian; Losos, Jonathan B; Edwards, Scott V

2017-08-04

Extreme environmental perturbations offer opportunities to observe the effects of natural selection in wild populations. During the winter of 2013-2014, the southeastern United States endured an extreme cold event. We used thermal performance, transcriptomics, and genome scans to measure responses of lizard populations to storm-induced selection. We found significant increases in cold tolerance at the species' southern limit. Gene expression in southern survivors shifted toward patterns characteristic of northern populations. Comparing samples before and after the extreme winter, 14 genomic regions were differentiated in the surviving southern population; four also exhibited signatures of local adaptation across the latitudinal gradient and implicate genes involved in nervous system function. Together, our results suggest that extreme winter events can rapidly produce strong selection on natural populations at multiple biological levels that recapitulate geographic patterns of local adaptation. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Rapid changes in gene expression direct rapid shifts in intestinal form and function in the Burmese python after feeding.

PubMed

Andrew, Audra L; Card, Daren C; Ruggiero, Robert P; Schield, Drew R; Adams, Richard H; Pollock, David D; Secor, Stephen M; Castoe, Todd A

2015-05-01

Snakes provide a unique and valuable model system for studying the extremes of physiological remodeling because of the ability of some species to rapidly upregulate organ form and function upon feeding. The predominant model species used to study such extreme responses has been the Burmese python because of the extreme nature of postfeeding response in this species. We analyzed the Burmese python intestine across a time series, before, during, and after feeding to understand the patterns and timing of changes in gene expression and their relationship to changes in intestinal form and function upon feeding. Our results indicate that >2,000 genes show significant changes in expression in the small intestine following feeding, including genes involved in intestinal morphology and function (e.g., hydrolases, microvillus proteins, trafficking and transport proteins), as well as genes involved in cell division and apoptosis. Extensive changes in gene expression occur surprisingly rapidly, within the first 6 h of feeding, coincide with changes in intestinal morphology, and effectively return to prefeeding levels within 10 days. Collectively, our results provide an unprecedented portrait of parallel changes in gene expression and intestinal morphology and physiology on a scale that is extreme both in the magnitude of changes, as well as in the incredibly short time frame of these changes, with up- and downregulation of expression and function occurring in the span of 10 days. Our results also identify conserved vertebrate signaling pathways that modulate these responses, which may suggest pathways for therapeutic modulation of intestinal function in humans. Copyright © 2015 the American Physiological Society.

Submarine Landslide Hazards Offshore Southern Alaska: Seismic Strengthening Versus Rapid Sedimentation

NASA Astrophysics Data System (ADS)

Sawyer, D.; Reece, R.; Gulick, S. P. S.; Lenz, B. L.

2017-12-01

The southern Alaskan offshore margin is prone to submarine landslides and tsunami hazards due to seismically active plate boundaries and extreme sedimentation rates from glacially enhanced mountain erosion. We examine the submarine landslide potential with new shear strength measurements acquired by Integrated Ocean Drilling Program Expedition 341 on the continental slope and Surveyor Fan. These data reveal lower than expected sediment strength. Contrary to other active margins where seismic strengthening enhances slope stability, the high-sedimentation margin offshore southern Alaska behaves like a passive margin from a shear strength perspective. We interpret that seismic strengthening occurs but is offset by high sedimentation rates and overpressure within the slope and Surveyor Fan. This conclusion is supported because shear strength follows an expected active margin profile outside of the fan, where background sedimentation rates occur. More broadly, seismically active margins with wet-based glaciers are susceptible to submarine landslide hazards because of the combination of high sedimentation rates and earthquake shaking

The fast food and obesity link: consumption patterns and severity of obesity.

PubMed

Garcia, Ginny; Sunil, Thankam S; Hinojosa, Pedro

2012-05-01

Rates of extreme forms of obesity are rapidly rising, as is the use of bariatric surgery for its treatment. The aim of the present study was to examine selected behavioral factors associated with severity of obesity among preoperative bariatric surgery patients in the San Antonio area, focusing specifically on the effects of fast food consumption. We used ordered logistic regression to model behavioral and attitudinal effects on obesity outcomes among 270 patients. These outcomes were based on the severity of obesity and were measured on the basis of body mass index. Our results indicated that, among the behavioral factors, fast food consumption exerted the largest influence on higher levels of obesity. These remained after controlling for several social and demographic characteristics. Our findings suggest that higher rates of fast food consumption are connected to the increasing rates of severe obesity. Given that morbid and super morbid obesity rates are growing at a more advanced pace than moderate obesity, it is necessary to explore the behavioral characteristics associated with these trends.

Extremely high-rate, uniform dissolution of alloy C-22 in anhydrous organic solutions at room temperature

DOE PAGES

Schindelholz, Eric J.; Christie, Michael A.; Allwein, Shawn P.; ...

2016-06-21

During routine pharmaceutical development and scale-up work, severe corrosion of a Hastelloy Alloy C-22 filter dryer was observed after single, short (several hours) contact with the product slurry at room temperature. Initial investigations showed that the presence of both 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HCl was sufficient in an acetonitrile solution to cause rapid corrosion of C-22. More detailed mass loss studies showed initial corrosion rates exceeding25 mm/year that then decreased over several hours to steady state rates of 3-5 mm/year. The corrosion was highly uniform. Electrochemical measurements demonstrated that although C-22 is spontaneously passive in acetonitrile solution, the presence of HClmore » leads to the development of a transpassive region. Furthermore, DDQ is a sufficiently strong oxidizer, particularly in acidic solutions, to polarize the C-22 well into the transpassive region, leading to the observed high corrosion rates.« less

Gene alterations at Drosophila inversion breakpoints provide prima facie evidence for natural selection as an explanation for rapid chromosomal evolution.

PubMed

Guillén, Yolanda; Ruiz, Alfredo

2012-02-01

Chromosomal inversions have been pervasive during the evolution of the genus Drosophila, but there is significant variation between lineages in the rate of rearrangement fixation. D. mojavensis, an ecological specialist adapted to a cactophilic niche under extreme desert conditions, is a chromosomally derived species with ten fixed inversions, five of them not present in any other species. In order to explore the causes of the rapid chromosomal evolution in D. mojavensis, we identified and characterized all breakpoints of seven inversions fixed in chromosome 2, the most dynamic one. One of the inversions presents unequivocal evidence for its generation by ectopic recombination between transposon copies and another two harbor inverted duplications of non-repetitive DNA at the two breakpoints and were likely generated by staggered single-strand breaks and repair by non-homologous end joining. Four out of 14 breakpoints lay in the intergenic region between preexisting duplicated genes, suggesting an adaptive advantage of separating previously tightly linked duplicates. Four out of 14 breakpoints are associated with transposed genes, suggesting these breakpoints are fragile regions. Finally two inversions contain novel genes at their breakpoints and another three show alterations of genes at breakpoints with potential adaptive significance. D. mojavensis chromosomal inversions were generated by multiple mechanisms, an observation that does not provide support for increased mutation rate as explanation for rapid chromosomal evolution. On the other hand, we have found a number of gene alterations at the breakpoints with putative adaptive consequences that directly point to natural selection as the cause of D. mojavensis rapid chromosomal evolution.

Changes in extreme temperature and precipitation events in the Loess Plateau (China) during 1960-2013 under global warming

NASA Astrophysics Data System (ADS)

Sun, Wenyi; Mu, Xingmin; Song, Xiaoyan; Wu, Dan; Cheng, Aifang; Qiu, Bing

2016-02-01

In recent decades, extreme climatic events have been a major issue worldwide. Regional assessments on various climates and geographic regions are needed for understanding uncertainties in extreme events' responses to global warming. The objective of this study was to assess the annual and decadal trends in 12 extreme temperature and 10 extreme precipitation indices in terms of intensity, frequency, and duration over the Loess Plateau during 1960-2013. The results indicated that the regionally averaged trends in temperature extremes were consistent with global warming. The occurrence of warm extremes, including summer days (SU), tropical nights (TR), warm days (TX90), and nights (TN90) and a warm spell duration indicator (WSDI), increased by 2.76 (P < 0.01), 1.24 (P < 0.01), 2.60 (P = 0.0003), 3.41 (P < 0.01), and 0.68 (P = 0.0041) days/decade during the period of 1960-2013, particularly, sharp increases in these indices occurred in 1985-2000. Over the same period, the occurrence of cold extremes, including frost days (FD), ice days (ID), cold days (TX10) and nights (TN10), and a cold spell duration indicator (CSDI) exhibited decreases of - 3.22 (P < 0.01), - 2.21 (P = 0.0028), - 2.71 (P = 0.0028), - 4.31 (P < 0.01), and - 0.69 (P = 0.0951) days/decade, respectively. Moreover, extreme warm events in most regions tended to increase while cold indices tended to decrease in the Loess Plateau, but the trend magnitudes of cold extremes were greater than those of warm extremes. The growing season (GSL) in the Loess Plateau was lengthened at a rate of 3.16 days/decade (P < 0.01). Diurnal temperature range (DTR) declined at a rate of - 0.06 °C /decade (P = 0.0931). Regarding the precipitation indices, the annual total precipitation (PRCPTOT) showed no obvious trends (P = 0.7828). The regionally averaged daily rainfall intensity (SDII) exhibited significant decreases (- 0.14 mm/day/decade, P = 0.0158), whereas consecutive dry days (CDD) significantly increased (1.96 days/decade, P = 0.0001) during 1960-2013. Most of stations with significant changes in SDII and CDD occurred in central and southeastern Loess Plateau. However, the changes in days of erosive rainfall, heavy rain, rainstorm, maximum 5-day precipitation, and very-wet-day and extremely wet-day precipitation were not significant. Large-scale atmospheric circulation indices, such as the Western Pacific Subtropical High Intensity Index (WPSHII) and Arctic Oscillation (AO), strongly influences warm/cold extremes and contributes significantly to climate changes in the Loess Plateau. The enhanced geopotential height over the Eurasian continent and increase in water vapor divergence in the rainy season have contributed to the changes of the rapid warming and consecutive drying in the Loess Plateau.

Going to extremes: contrasting rates of diversification in a recent radiation of new world passerine birds.

PubMed

Barker, F Keith; Burns, Kevin J; Klicka, John; Lanyon, Scott M; Lovette, Irby J

2013-03-01

Recent analyses suggest that a few major shifts in diversification rate may be enough to explain most of the disparity in diversity among vertebrate lineages. At least one significant increase in diversification rate appears to have occurred within the birds; however, several nested lineages within birds have been identified as hyperdiverse by different studies. A clade containing the finches and relatives (within the avian order Passeriformes), including a large radiation endemic to the New World that comprises ~8% of all bird species, may be the true driver of this rate increase. Understanding the patterns and processes of diversification of this diverse lineage may go a long way toward explaining the apparently rapid diversification rates of both passerines and of birds as a whole. We present the first multilocus phylogenetic analyses of this endemic New World radiation of finch relatives that include sampling of all recognized genera, a relaxed molecular clock analysis of its divergence history, and an analysis of its broad-scale diversification patterns. These analyses recovered 5 major lineages traditionally recognized as avian families, but identified an additional 10 relatively ancient lineages worthy of recognition at the family level. Time-calibrated diversification analyses suggested that at least 3 of the 15 family-level lineages were significantly species poor given the entire group's background diversification rate, whereas at least one-the tanagers of family Thraupidae-appeared significantly more diverse. Lack of an age-diversity relationship within this clade suggests that, due to rapid initial speciation, it may have experienced density-dependent ecological limits on its overall diversity.

Creep Strain and Strain Rate Response of 2219 Al Alloy at High Stress Levels

NASA Technical Reports Server (NTRS)

Taminger, Karen M. B.; Wagner, John A.; Lisagor, W. Barry

1998-01-01

As a result of high localized plastic deformation experienced during proof testing in an International Space Station connecting module, a study was undertaken to determine the deformation response of a 2219-T851 roll forging. After prestraining 2219-T851 Al specimens to simulate strains observed during the proof testing, creep tests were conducted in the temperature range from ambient temperature to 107 C (225 F) at stress levels approaching the ultimate tensile strength of 2219-T851 Al. Strain-time histories and strain rate responses were examined. The strain rate response was extremely high initially, but decayed rapidly, spanning as much as five orders of magnitude during primary creep. Select specimens were subjected to incremental step loading and exhibited initial creep rates of similar magnitude for each load step. Although the creep rates decreased quickly at all loads, the creep rates dropped faster and reached lower strain rate levels for lower applied loads. The initial creep rate and creep rate decay associated with primary creep were similar for specimens with and without prestrain; however, prestraining (strain hardening) the specimens, as in the aforementioned proof test, resulted in significantly longer creep life.

Development and validation of polar RP-HPLC method for screening for ectoine high-yield strains in marine bacteria with green chemistry.

PubMed

Chen, Jun; Chen, Jianwei; Wang, Sijia; Zhou, Guangmin; Chen, Danqing; Zhang, Huawei; Wang, Hong

2018-04-02

A novel, green, rapid, and precise polar RP-HPLC method has been successfully developed and screened for ectoine high-yield strain in marine bacteria. Ectoine is a polar and extremely useful solute which allows microorganisms to survive in extreme environmental salinity. This paper describes a polar-HPLC method employed polar RP-C18 (5 μm, 250 × 4.6 mm) using pure water as the mobile phase and a column temperature of 30 °C, coupled with a flow rate at 1.0 mL/min and detected under a UV detector at wavelength of 210 nm. Our method validation demonstrates excellent linearity (R 2  = 0.9993), accuracy (100.55%), and a limit of detection LOQ and LOD of 0.372 and 0.123 μgmL -1 , respectively. These results clearly indicate that the developed polar RP-HPLC method for the separation and determination of ectoine is superior to earlier protocols.

Antimicrobial Resistance in Asia: Current Epidemiology and Clinical Implications

PubMed Central

Kang, Cheol-In

2013-01-01

Antimicrobial resistance has become one of the most serious public health concerns worldwide. Although circumstances may vary by region or country, it is clear that some Asian countries are epicenters of resistance, having seen rapid increases in the prevalence of antimicrobial resistance of major bacterial pathogens. In these locations, however, the public health infrastructure to combat this problem is very poor. The prevalence rates of methicillin-resistant Staphylococcus aureus (MRSA), macrolide-resistant Streptococcus pneumoniae, and multidrug-resistant enteric pathogens are very high due to the recent emergence of extremely drug-resistant gram-negative bacilli in Asia. Because antimicrobial options for these pathogens are extremely limited, infections caused by antimicrobial-resistant bacteria are often associated with inappropriate antimicrobial therapy and poor clinical outcomes. Physicians should be aware of the current epidemiological status of resistance and understand the appropriate use of antimicrobial agents in clinical practice. This review focuses on describing the epidemiology and clinical implications of antimicrobial-resistant bacterial infections in Asian countries. PMID:24265947

Temperature and neuronal circuit function: compensation, tuning and tolerance.

PubMed

Robertson, R Meldrum; Money, Tomas G A

2012-08-01

Temperature has widespread and diverse effects on different subcellular components of neuronal circuits making it difficult to predict precisely the overall influence on output. Increases in temperature generally increase the output rate in either an exponential or a linear manner. Circuits with a slow output tend to respond exponentially with relatively high Q(10)s, whereas those with faster outputs tend to respond in a linear fashion with relatively low temperature coefficients. Different attributes of the circuit output can be compensated by virtue of opposing processes with similar temperature coefficients. At the extremes of the temperature range, differences in the temperature coefficients of circuit mechanisms cannot be compensated and the circuit fails, often with a reversible loss of ion homeostasis. Prior experience of temperature extremes activates conserved processes of phenotypic plasticity that tune neuronal circuits to be better able to withstand the effects of temperature and to recover more rapidly from failure. Copyright © 2012 Elsevier Ltd. All rights reserved.

Patterns of residual stresses due to welding

NASA Technical Reports Server (NTRS)

Botros, B. M.

1983-01-01

Residual stresses caused by welding result from the nonuniform rate of cooling and the restrained thermal contraction or non-uniform plastic deformation. From the zone of extremely high temperature at the weld, heat flows into both the adjoining cool body and the surrounding atmosphere. The weld metal solidifies under very rapid cooling. The plasticity of the hot metal allows adjustment initially, but as the structure cools the rigidity of the surrounding cold metal inhibits further contraction. The zone is compressed and the weld is put under tensile stresses of high magnitude. The danger of cracking in these structural elements is great. Change in specific volume is caused by the change in temperature.

Some aspects of the thermal history of lunar glass.

NASA Technical Reports Server (NTRS)

Cooper, A. R.; Varshneya, A. K.; Sarkar, S. K.; Swift, J.; Klein, L.; Yen, F.

1972-01-01

Electron microprobe examination revealed that glassy lunar fragments had inclusions as well as boundaries between mineral glasses of different compositions. Glassy lunar spherules showed detectable heterogeneity less marked than that of the fragments. The room-temperature refractive indices and densities of the spherules are changed by heat-treating them at 500 to 700 C. The large increases (as much as 2% in density and 0.7% in index of refraction) are difficult to explain on the basis of classical glass-transition phenomena alone unless extremely rapid cooling rates are assumed. Further, the spherules darkened significantly when they were heated in air or a medium vacuum above 625 C.

Rain Characteristics and Large-Scale Environments of Precipitation Objects with Extreme Rain Volumes from TRMM Observations

NASA Technical Reports Server (NTRS)

Zhou, Yaping; Lau, William K M.; Liu, Chuntao

2013-01-01

This study adopts a "precipitation object" approach by using 14 years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Feature (PF) and National Centers for Environmental Prediction (NCEP) reanalysis data to study rainfall structure and environmental factors associated with extreme heavy rain events. Characteristics of instantaneous extreme volumetric PFs are examined and compared to those of intermediate and small systems. It is found that instantaneous PFs exhibit a much wider scale range compared to the daily gridded precipitation accumulation range. The top 1% of the rainiest PFs contribute over 55% of total rainfall and have 2 orders of rain volume magnitude greater than those of the median PFs. We find a threshold near the top 10% beyond which the PFs grow exponentially into larger, deeper, and colder rain systems. NCEP reanalyses show that midlevel relative humidity and total precipitable water increase steadily with increasingly larger PFs, along with a rapid increase of 500 hPa upward vertical velocity beyond the top 10%. This provides the necessary moisture convergence to amplify and sustain the extreme events. The rapid increase in vertical motion is associated with the release of convective available potential energy (CAPE) in mature systems, as is evident in the increase in CAPE of PFs up to 10% and the subsequent dropoff. The study illustrates distinct stages in the development of an extreme rainfall event including: (1) a systematic buildup in large-scale temperature and moisture, (2) a rapid change in rain structure, (3) explosive growth of the PF size, and (4) a release of CAPE before the demise of the event.

Transfer Rates of Magma From Planetary Mantles to the Surface.

NASA Astrophysics Data System (ADS)

Wilson, L.; Head, J. W.; Parfitt, E. A.

2008-12-01

We discuss the speed at which magma can be transferred to a planetary surface from the deep interior. Current literature describes a combination of slow percolation of melt in the mantle where convection-driven pressure-release melting is occurring, concentration of melt by source region deformation, initiation and growth of magma-filled brittle fractures (dikes) providing wider pathways for melt movement, additional growth and interconnection of dikes with decreasing depth, rise of magma to storage zones (reservoirs) located at levels of neutral buoyancy at the base of or within the crust, and transfer from the storage zones in dikes to feed eruptions or intrusions. We do not take issue with these mechanisms but think that their relative importance in various circumstances is poorly appreciated. On Earth, preservation of diamonds in kimberlites implies very rapid (hours) transfer of melts from depths of 100-300 km, and there is strong geochemical evidence that magmas at mid-ocean ridges reach shallow depths faster than is possible by percolation alone. On the Moon, the petrology of pyroclasts involved in dark-mantle-forming eruptions implies rapid (again probably hours) magma transfer from depths of up to 400 km. The ureilite meteorites, samples of the mantle of a disrupted asteroid 200 km in diameter, have compositions only consistent with the rapid (months) extraction of mafic melt from the mantle. All of these examples imply that brittle fractures (dikes) can sometimes be initiated at depths where mantle rheology would normally be expected to be plastic rather than elastic, and that melt can be fed into these dikes extremely efficiently. Further evidence for this is provided by the giant radial dike swarms observed on Earth, Mars and Venus. The dikes observed (on Earth) and inferred from the presence of radiating graben systems (Mars) and radiating fracture and graben systems (Venus) are so voluminous that they can only be understood if they are fed from extremely large magma reservoirs, probably located at the base of the crust, that are supplied from the mantle (i.e. buffered) while the dikes are being emplaced, again implying extremely efficient melt extraction from mantle source regions.

Tolerance of Lower Body Negative Pressure (LBNP) in endurance runners, weightlifters, swimmers and nonathletes

NASA Technical Reports Server (NTRS)

1980-01-01

Thirteen endurance runners (R), 12 weightlifters (WL), 12 swimmers (SW) and 10 nonathletes (NA) were tested for their tolerance of lower body negative pressure (LBNP) in consecutive 5 minute stages at -20, -30, -40, -50 and -60 torr. Each subject also performed an exercise test on a bicycle ergometer with progressive workloads to exhaustion to determined aerobic capacity. The R had a much higher aerobic capacity than any of the other groups, but a significantly lower LBNP tolerance. While responses in heart rate and pulse pressure were quite similar in all 4 groups, the rate of increase in leg volume relative to LBNP stress (leg compliance, LC) was considerably greater in R than in the other athletes and NA. The greater LC in R could be attributed not only to a more rapid shift of blood to the lower extremities but also to a greater tendency for edema formation, both contributing to a more rapid loss in effective central blood volume for a given LBNP stress. These results substantiate earlier observations which led to the conclusion that endurance running is not advisable as a training regimen for astronauts.

Extreme beach retreat history inferred from cut-and-fill beach deposits at Moruya, SE Australia

NASA Astrophysics Data System (ADS)

Tamura, T.; Woodroffe, C. D.; Oliver, T.; Cunningham, A. C.

2017-12-01

A sequence of beach ridges often records a `cut and fill', where the fair-weather swash accretion of beach sand is punctuated by storm erosion. The detailed chronology of the sequence is thus a clue to decipher past storm events and associated beach erosion, but has not been explored much. Here we explore the potential of such a sequence to detect past extreme retreats in Bengello Beach at Moruya, southeastern Australia. Beach monitoring since 1972 reveals that Bengello beach has shown a typical cut and fill, in which the beach retreats several tens of meters in relation to storms and recovers within a following few years. A storm event caused extreme retreat up to 50 m in 1974. Since then, no retreat exceeded 30 m. The beach monitoring highlights the sporadic nature of the prograded beach deposits; they can only be preserved as stratigraphic records during rapid beach recovery following a large retreat deeper than the beach profile envelope. Thus, ages of the preserved beach deposits roughly correspond to timings of large retreat. Optically-stimulated luminescence (OSL) ages were determined for beach deposits at 5-10 m intervals along a shore-normal transect from the modern foredune to beach ridge 120 m inland. The most landward sample was dated as 510 yr, indicating that the net progradation rate is 0.24 m/yr, concordant with both the long- and short-term rates since the mid Holocene and 1972, respectively. Other ages show four events of retreat around 350, 180, 130 and 90 yr, and also reflect the beach scarp resulting from the 1974 event. The retreat of each event is given by the distance between the shoreline position prior to storm erosion and relevant gap in OSL age. The position of the pre-storm shoreline is estimated by assuming a constant rate of the net progradation of 0.24 m/yr, as with long- and short-term rates. The retreat of the four events is then determined as 45-55 m, similar to the 1974 event. In summary, extreme beach retreats, including that in 1974, appear to have happened at least five times over the last 350 years with a variable recurrence interval of 50-150 years at Moruya. Multi-timescale analysis of the beach-ridge sequence as shown in Moruya has the potential to detect past extreme beach retreat that should be taken into account for the long-term coastal management.

Using Extreme Tropical Precipitation Statistics to Constrain Future Climate States

NASA Astrophysics Data System (ADS)

Igel, M.; Biello, J. A.

2017-12-01

Tropical precipitation is characterized by a rapid growth in mean intensity as the column humidity increases. This behavior is examined in both a cloud resolving model and with high-resolution observations of precipitation and column humidity from CloudSat and AIRS, respectively. The model and the observations exhibit remarkable consistency and suggest a new paradigm for extreme precipitation. We show that the total precipitation can be decomposed into a product of contributions from a mean intensity, a probability of precipitation, and a global PDF of column humidity values. We use the modeling and observational results to suggest simple, analytic forms for each of these functions. The analytic representations are then used to construct a simple expression for the global accumulated precipitation as a function of the parameters of each of the component functions. As the climate warms, extreme precipitation intensity and global precipitation are expected to increase, though at different rates. When these predictions are incorporated into the new analytic expression for total precipitation, predictions for changes due to global warming to the probability of precipitation and the PDF of column humidity can be made. We show that strong constraints can be imposed on the future shape of the PDF of column humidity but that only weak constraints can be set on the probability of precipitation. These are largely imposed by the intensification of extreme precipitation. This result suggests that understanding precisely how extreme precipitation responds to climate warming is critical to predicting other impactful properties of global hydrology. The new framework can also be used to confirm and discount existing theories for shifting precipitation.

Extreme-value dependence: An application to exchange rate markets

NASA Astrophysics Data System (ADS)

Fernandez, Viviana

2007-04-01

Extreme value theory (EVT) focuses on modeling the tail behavior of a loss distribution using only extreme values rather than the whole data set. For a sample of 10 countries with dirty/free float regimes, we investigate whether paired currencies exhibit a pattern of asymptotic dependence. That is, whether an extremely large appreciation or depreciation in the nominal exchange rate of one country might transmit to another. In general, after controlling for volatility clustering and inertia in returns, we do not find evidence of extreme-value dependence between paired exchange rates. However, for asymptotic-independent paired returns, we find that tail dependency of exchange rates is stronger under large appreciations than under large depreciations.

Tidal Disruption Events from Eccentric Nuclear Disks

NASA Astrophysics Data System (ADS)

Wernke, Heather N.; Madigan, Ann-Marie

2018-04-01

Stars that get too close to a supermassive black hole are in danger of being tidally disrupted. Stellar two-body relaxation is commonly assumed to be the main driver of these events. Recent work has shown, however, that secular gravitational torques from eccentric nuclear disks can push stars to extreme eccentricities at much higher rates than predicted by two-body relaxation. This work did not include the effects of general relativity, however, which could quench secular torques via rapid apsidal precession. Here we show that, for a star in danger of disruption, general relativity acts on a timescale of less than an orbital period. This short timescale means that general relativity does not have enough time to have a major effect on the orbit. When driven by secular torques from eccentric nuclear disks, tidal disruption event rates are not affected by general relativity.

Friction and oxidative wear of 440C ball bearing steels under high load and extreme bulk temperatures

NASA Technical Reports Server (NTRS)

Chaudhuri, Dilip K.; Slifka, Andrew J.; Siegwarth, James D.

1993-01-01

Unlubricated sliding friction and wear of 440C steels in an oxygen environment have been studied under a variety of load, speed, and temperature ranging from approximately -185 to 675 deg C. A specially designed test apparatus with a ball-on-flat geometry has been used for this purpose. The observed dependencies of the initial coefficient of friction, the average dynamic coefficient of friction, and the wear rate on load, speed, and test temperatures have been examined from the standpoint of existing theories of friction and wear. High contact temperatures are generated during the sliding friction, causing rapid oxidation and localized surface melting. A combination of fatigue, delamination, and loss of hardness due to tempering of the martensitic structure is responsible for the high wear rate observed and the coefficient of friction.

Fallout Radionuclides as Tracers in Southern Alps Sediment Studies

NASA Astrophysics Data System (ADS)

Carey, A. E.; Karanovic, Z.; Dibb, J. E.

2005-12-01

The primary geologic processes shaping the landscape are physical and chemical weathering and the transport of solids by erosion. As part of our studies on the coupling between physical erosion and chemical weathering, we have determined depositional and erosional processes in New Zealand's tectonically active, rapidly uplifting Southern Alps, specifically focusing on the Hokitika River watershed. The South Island watersheds we are studying are subject to extreme orographic precipitation (as high as 7-12 m annually) and high landslide frequency, but have modest topography due to the rapid erosion. In concert with our studies of chemical weathering and physical erosion, we have used the atmospherically-delivered radionuclides of 7Be, 137Cs and 210Pbexcess to determine the relative magnitude of particle residence time in the high elevation Cropp and Whitcombe subwatersheds and the rates of sedimentation. One- and two-box modeling with 7Be and 210Pbexcess was used to determine soil and sediment residence times. Residence time of fine suspended particles is short and particles can travel the length of the river during a single storm, probably due to the short duration, high-intensity rainfalls which produce rapidly moving, steep flood waves. The readily detected peak of 137Cs activity in Cropp terrace and Hokitika gorge soils yielded sedimentation rates of 0.06-0.12 cm yr-1. At the Cropp terrace, inventory models of 210Pbexcess yield soil accumulation rates significantly less than those determined using the 137Cs activity peak. We attribute the differences to overestimation of 210Pbexcess in surface soils and to contrasting fallout fluxes, geochemical behavior and radionuclide contents of sedimenting materials. Total inventories of 210Pbexcess in soils greatly exceed the expected direct atmospheric deposition, suggesting that lateral transport of this nuclide occurs within the watershed. At the Hokitika gorge, all nuclides studied yielded similar sedimentation rates, confirming the potential of 210Pbexcess for determining sedimentation rates in New Zealand watersheds with very low 137Cs inventories.

Rapid recovery protocol for peri-operative care of total hip and total knee arthroplasty patients.

PubMed

Berend, Keith R; Lombardi, Adolph V; Mallory, Thomas H

2004-01-01

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are among the most successful procedures performed in terms of quality-of-life years gained. The long-term goals of arthroplasty, to relieve pain, increase function, provide stability, and obtain durability, are accomplished in the vast majority of cases. The short-term goals, however, have become the target of aggressive peri-operative programs that aim to speed recovery, reduce morbidity and complications, and create a program of efficiency while maintaining the highest level of patient care. The concept of rapid recovery is built upon the burgeoning interest in less-invasive and small-incision surgeries for (THA and TKA). However, the incision size does not appear to be the most critical aspect of the program. This article outlines the specific elements of the rapid-recovery program for lower-extremity arthroplasty patients, including pre-operative patient education, peri-operative nutrition, vitamin and herbal medication supplementation, preemptive analgesia, and post-operative rehabilitation. A holistic peri-operative, rapid-recovery program has lead to a significantly decreased hospital length of stay and significantly lower hospital readmission rates in patients who undergo primary THAs and TKAs. Combining these results with minimally invasive techniques and instrumentation should make recovery even faster.

Evolution under changing climates: climatic niche stasis despite rapid evolution in a non-native plant.

PubMed

Alexander, Jake M

2013-09-22

A topic of great current interest is the capacity of populations to adapt genetically to rapidly changing climates, for example by evolving the timing of life-history events, but this is challenging to address experimentally. I use a plant invasion as a model system to tackle this question by combining molecular markers, a common garden experiment and climatic niche modelling. This approach reveals that non-native Lactuca serriola originates primarily from Europe, a climatic subset of its native range, with low rates of admixture from Asia. It has rapidly refilled its climatic niche in the new range, associated with the evolution of flowering phenology to produce clines along climate gradients that mirror those across the native range. Consequently, some non-native plants have evolved development times and grow under climates more extreme than those found in Europe, but not among populations from the native range as a whole. This suggests that many plant populations can adapt rapidly to changed climatic conditions that are already within the climatic niche space occupied by the species elsewhere in its range, but that evolution to conditions outside of this range is more difficult. These findings can also help to explain the prevalence of niche conservatism among non-native species.

Rapid isothermal detection of Phytophthora species on plant samples using recombinase polymerase amplification

USDA-ARS?s Scientific Manuscript database

Recently several isothermal amplification techniques have been developed that are extremely tolerant towards inhibitors present in many plant extracts. Recombinase polymerase amplification (RPA) assays for the genus Phytophthora have been developed which provide a simple and rapid method to macerate...

Income inequality and obesity prevalence among OECD countries.

PubMed

Su, Dejun; Esqueda, Omar A; Li, Lifeng; Pagán, José A

2012-07-01

Using recent pooled data from the World Health Organization Global Infobase and the World Factbook compiled by the Central Intelligence Agency of the United States, this study assesses the relation between income inequality and obesity prevalence among 31 OECD countries through a series of bivariate and multivariate linear regressions. The United States and Mexico well lead OECD countries in both obesity prevalence and income inequality. A sensitivity analysis suggests that the inclusion or exclusion of these two extreme cases can fundamentally change the findings. When the two countries are included, the results reveal a positive correlation between income inequality and obesity prevalence. This correlation is more salient among females than among males. Income inequality alone is associated with 16% and 35% of the variations in male and female obesity rates, respectively, across OECD countries in 2010. Higher levels of income inequality in the 2005-2010 period were associated with a more rapid increase in obesity prevalence from 2002 to 2010. These associations, however, virtually disappear when the US and Mexico have been excluded from the analysis. Findings from this study underscore the importance of assessing the impact of extreme cases on the relation between income inequality and health outcomes. The potential pathways from income inequality to the alarmingly high rates of obesity in the cases of the US and Mexico warrant further research.

Quantification of long-term erosion rates from root exposure/tree age relationships in an alpine meadow catchment

NASA Astrophysics Data System (ADS)

Scuderi, Louis A.

2017-04-01

Erosion rates derived using dendrogeomorphology have been used to quantify slope degradation in many localities globally. However, with the exception of the western United States, most of these estimates are derived from short-lived trees whose lifetimes may not adequately reflect the complete range of slope processes which can include erosion, deposition, impacts of extreme events and even long-term hiatuses. Erosion rate estimates at a given site using standard techniques therefore reflect censored local point erosion estimates rather than long-term rates. We applied a modified dendrogeomorphic approach to rapidly estimate erosion rates from dbh/age relationships to assess the difference between short and long-term rates and found that the mean short-term rate was 0.13 cm/yr with high variability, while the uncensored long-term rate was 0.06 cm/yr. The results indicate that rates calculated from short-lived trees, while possibly appropriate for local short-term point estimates of erosion, are highly variable and may overestimate regional long-term rates by > 50%. While these findings do not invalidate the use of dendrogeomorphology to estimate erosion rates they do suggest that care must be taken to select older trees that incorporate a range of slope histories in order to best approximate regional long-term rates.

Properties of Extreme Precipitation and Their Uncertainties in 3-year GPM Precipitation Radar Data

NASA Astrophysics Data System (ADS)

Liu, N.; Liu, C.

2017-12-01

Extreme high precipitation rates are often related to flash floods and have devastating impacts on human society and the environments. To better understand these rare events, 3-year Precipitation Features (PFs) are defined by grouping the contiguous areas with nonzero near-surface precipitation derived using Global Precipitation Measurement (GPM) Ku band Precipitation Radar (KuPR). The properties of PFs with extreme precipitation rates greater than 20, 50, 100 mm/hr, such as the geographical distribution, volumetric precipitation contribution, seasonal and diurnal variations, are examined. In addition to the large seasonal and regional variations, the rare extreme precipitation rates often have a larger contribution to the local total precipitation. Extreme precipitation rates occur more often over land than over ocean. The challenges in the retrieval of extreme precipitation might be from the attenuation correction and large uncertainties in the Z-R relationships from near-surface radar reflectivity to precipitation rates. These potential uncertainties are examined by using collocated ground based radar reflectivity and precipitation retrievals.

Global Landslides on Rapidly Spinning Spheroids

NASA Astrophysics Data System (ADS)

Scheeres, Daniel J.; Sanchez, P.

2013-10-01

The angle of repose and conditions for global landslides on the surfaces of small, rapidly spinning, spheroidal asteroids are studied. Applying techniques of soil mechanics, we develop a theory for, and examples of, how regolith will fail and flow in this microgravity environment. Our motivation is to develop an understanding of the "top-shaped" class of asteroids based on analytical soil mechanics. Our analysis transforms the entire asteroid surface into a local frame where we can model it as a conventional granular pile with a surface slope, acceleration and height variations as a function of the body's spin rate, shape and density. A general finding is that the lowest point on a rapidly spinning spheroid is at the equator with the effective height of surface material monotonically increasing towards the polar regions, where the height can be larger than the physical radius of the body. We study the failure conditions of both cohesionless and cohesive regolith, and develop specific predictions of the surface profile as a function of the regolith angle of friction and the maximum spin rate experienced by the body. The theory also provides simple guidelines on what the shape may look like, although we do not analyze gravitationally self-consistent evolution of the body shape. The theory is tested with soft-sphere discrete element method granular mechanics simulations to better understand the dynamical aspects of global asteroid landslides. We find significant differences between failure conditions for cohesive and cohesionless regolith. In the case of cohesive regolith, we show that extremely small values of strength (much less than that found in lunar regolith) can stabilize a surface even at very rapid spin rates. Cohesionless surfaces, as expected, fail whenever their surface slopes exceed the angle of friction. Based on our analysis we propose that global landslides and the flow of material towards the equator on spheroidal bodies are precipitated by exogenous effects such as impact induced seismic shaking or torques during planetary flybys.

Halophilic mechanism of the enzymatic function of a moderately halophilic dihydrofolate reductase from Haloarcula japonica strain TR-1.

PubMed

Miyashita, Yurina; Ohmae, Eiji; Ikura, Teikichi; Nakasone, Kaoru; Katayanagi, Katsuo

2017-05-01

Dihydrofolate (DHF) reductase coded by a plasmid of the extremely halophilic archaeon Haloarcula japonica strain TR-1 (HjDHFR P1) shows moderate halophilicity on enzymatic activity at pH 6.0, although there is no significant effect of NaCl on its secondary structure. To elucidate the salt-activation and -inactivation mechanisms of this enzyme, we investigated the effects of pH and salt concentration, deuterium isotope effect, steady-state kinetics, and rapid-phase ligand-binding kinetics. Enzyme activity was increased eightfold by the addition of 500 mM NaCl at pH 6.0, fourfold by 250 mM at pH 8.0, and became independent of salt concentration at pH 10.0. Full isotope effects observed at pH 10.0 under 0-1000 mM NaCl indicated that the rate of hydride transfer, which was the rate-determining step at the basic pH region, was independent of salt concentration. Conversely, rapid-phase ligand-binding experiments showed that the amplitude of the DHF-binding reaction increased and the tetrahydrofolate (THF)-releasing rate decreased with increasing NaCl concentration. These results suggested that the salt-activation mechanism of HjDHFR P1 is via the population change of the anion-unbound and anion-bound conformers, which are binding-incompetent and -competent conformations for DHF, respectively, while that of salt inactivation is via deceleration of the THF-releasing rate, which is the rate-determining step at the neutral pH region.

Suction is kid's play: extremely fast suction in newborn seahorses.

PubMed

Van Wassenbergh, Sam; Roos, Gert; Genbrugge, Annelies; Leysen, Heleen; Aerts, Peter; Adriaens, Dominique; Herrel, Anthony

2009-04-23

Ongoing anatomical development typically results in a gradual maturation of the feeding movements from larval to adult fishes. Adult seahorses are known to capture prey by rotating their long-snouted head extremely quickly towards prey, followed by powerful suction. This type of suction is powered by elastic recoil and requires very precise coordination of the movements of the associated feeding structures, making it an all-or-none phenomenon. Here, we show that newborn Hippocampus reidi are able to successfully feed using an extremely rapid and powerful snout rotation combined with a high-volume suction, surpassing that observed in adult seahorses. An inverse dynamic analysis shows that an elastic recoil mechanism is also used to power head rotation in newborn H. reidi. This illustrates how extreme levels of performance in highly complex musculoskeletal systems can be present at birth given a delayed birth and rapid development of functionally important structures. The fact that the head skeleton of newborn seahorses is still largely cartilaginous may not be problematic because the hydrodynamic stress on the rotating snout appeared considerably lower than in adult syngnathids.

Suction is kid's play: extremely fast suction in newborn seahorses

PubMed Central

Van Wassenbergh, Sam; Roos, Gert; Genbrugge, Annelies; Leysen, Heleen; Aerts, Peter; Adriaens, Dominique; Herrel, Anthony

2009-01-01

Ongoing anatomical development typically results in a gradual maturation of the feeding movements from larval to adult fishes. Adult seahorses are known to capture prey by rotating their long-snouted head extremely quickly towards prey, followed by powerful suction. This type of suction is powered by elastic recoil and requires very precise coordination of the movements of the associated feeding structures, making it an all-or-none phenomenon. Here, we show that newborn Hippocampus reidi are able to successfully feed using an extremely rapid and powerful snout rotation combined with a high-volume suction, surpassing that observed in adult seahorses. An inverse dynamic analysis shows that an elastic recoil mechanism is also used to power head rotation in newborn H. reidi. This illustrates how extreme levels of performance in highly complex musculoskeletal systems can be present at birth given a delayed birth and rapid development of functionally important structures. The fact that the head skeleton of newborn seahorses is still largely cartilaginous may not be problematic because the hydrodynamic stress on the rotating snout appeared considerably lower than in adult syngnathids. PMID:19324657

The Microphysical Structure of Extreme Precipitation as Inferred from Ground-Based Raindrop Spectra.

NASA Astrophysics Data System (ADS)

Uijlenhoet, Remko; Smith, James A.; Steiner, Matthias

2003-05-01

The controls on the variability of raindrop size distributions in extreme rainfall and the associated radar reflectivity-rain rate relationships are studied using a scaling-law formalism for the description of raindrop size distributions and their properties. This scaling-law formalism enables a separation of the effects of changes in the scale of the raindrop size distribution from those in its shape. Parameters controlling the scale and shape of the scaled raindrop size distribution may be related to the microphysical processes generating extreme rainfall. A global scaling analysis of raindrop size distributions corresponding to rain rates exceeding 100 mm h1, collected during the 1950s with the Illinois State Water Survey raindrop camera in Miami, Florida, reveals that extreme rain rates tend to be associated with conditions in which the variability of the raindrop size distribution is strongly number controlled (i.e., characteristic drop sizes are roughly constant). This means that changes in properties of raindrop size distributions in extreme rainfall are largely produced by varying raindrop concentrations. As a result, rainfall integral variables (such as radar reflectivity and rain rate) are roughly proportional to each other, which is consistent with the concept of the so-called equilibrium raindrop size distribution and has profound implications for radar measurement of extreme rainfall. A time series analysis for two contrasting extreme rainfall events supports the hypothesis that the variability of raindrop size distributions for extreme rain rates is strongly number controlled. However, this analysis also reveals that the actual shapes of the (measured and scaled) spectra may differ significantly from storm to storm. This implies that the exponents of power-law radar reflectivity-rain rate relationships may be similar, and close to unity, for different extreme rainfall events, but their prefactors may differ substantially. Consequently, there is no unique radar reflectivity-rain rate relationship for extreme rain rates, but the variability is essentially reduced to one free parameter (i.e., the prefactor). It is suggested that this free parameter may be estimated on the basis of differential reflectivity measurements in extreme rainfall.

Commercial Education 1926-1928. Bulletin, 1929, No. 26

ERIC Educational Resources Information Center

Malott, J. O.

1929-01-01

The extremely rapid development of new and diverse industries, the equally rapid modification of older industries and business practices, the reshaping of domestic and foreign business relationships, and recent economic changes indicate emphatically the growing responsibility of education for economic and business leadership. A continuing, capable…

Vibrio natriegens: A Rapidly Growing Micro-Organism Ideally Suited for Class Experiments

ERIC Educational Resources Information Center

Mullenger, L.; Gill, Nijole R.

1973-01-01

Describes five microbiological experiments using the marine organism Vibrio natriegens. This organism is highly suitable for laboratory work because it is non-pathogenic and grows extremely rapidly, having the distinction of the lowest mean generation time yet recorded (9.8 minutes). (JR)

[Soft tissue sarcoma of the upper extremities. Analysis of factors relevant for prognosis in 160 patients].

PubMed

Lehnhardt, M; Hirche, C; Daigeler, A; Goertz, O; Ring, A; Hirsch, T; Drücke, D; Hauser, J; Steinau, H U

2012-02-01

Soft tissue sarcomas (STS) are a rare entity with reduced prognosis due to their aggressive biology. For an optimal treatment of STS identification of independent prognostic factors is crucial in order to reduce tumor-related mortality and recurrence rates. The surgical oncological concept includes wide excisions with resection safety margins >1 cm which enables acceptable functional results and reduced rates of amputation of the lower extremities. In contrast, individual anatomy of the upper extremities, in particular of the hand, leads to an intentional reduction of resection margins in order to preserve the extremity and its function with the main intention of tumor-free resection margins. In this study, the oncological safety and outcome as well as functional results were validated by a retrospective analysis of survival rate, recurrence rate and potential prognostic factors. A total of 160 patients who had been treated for STS of the upper extremities were retrospectively included. Independent prognostic factors were analyzed (primary versus recurrent tumor, tumor size, resection status, grade of malignancy, additional therapy, localization in the upper extremity). Kaplan-Meier analyses for survival rate and local control were calculated. Further outcome measures were functional results validated by the DASH score and rate of amputation. In 130 patients (81%) wide tumor excision (R0) was performed and in 19 patients (12%) an amputation was necessary. The 5-year overall survival rate was 70% and the 5-year survival rate in primary tumors was 81% whereas in recurrences 55% relapsed locally. The 10-year overall survival rate was 45% and the 5-year recurrence rate was 18% for primary STS and 43% for recurrent STS. Variance analysis revealed primary versus recurrent tumor, tumor size, resection status and grade of malignancy as independent prognostic factors. Analysis of functional results showed a median DASH score of 37 (0-100; 0=contralateral extremity). The 5-year survival and local recurrence rates are comparable to STS wide resections with safety margins >1 cm for the lower extremities and the trunk. Analysis of prognostic factors revealed resection status and the tumor-free resection margins to be the main goals in STS resection of upper extremity.

Pediatric Major Head Injury: Not a Minor Problem.

PubMed

Leetch, Aaron N; Wilson, Bryan

2018-05-01

Traumatic brain injury is a highly prevalent and devastating cause of morbidity and mortality in children. A rapid, stepwise approach to the traumatized child should proceed, addressing life-threatening problems first. Management focuses on preventing secondary injury from physiologic extremes such as hypoxemia, hypotension, prolonged hyperventilation, temperature extremes, and rapid changes in cerebral blood flow. Initial Glasgow Coma Score, hyperglycemia, and imaging are often prognostic of outcome. Surgically amenable lesions should be evacuated promptly. Reduction of intracranial pressure through hyperosmolar therapy, decompressive craniotomy, and seizure prophylaxis may be considered after stabilization. Nonaccidental trauma should be considered when evaluating pediatric trauma patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Adaptive Tunable Laser Spectrometer for Space Applications

NASA Technical Reports Server (NTRS)

Flesch, Gregory; Keymeulen, Didier

2010-01-01

An architecture and process for the rapid prototyping and subsequent development of an adaptive tunable laser absorption spectrometer (TLS) are described. Our digital hardware/firmware/software platform is both reconfigurable at design time as well as autonomously adaptive in real-time for both post-integration and post-launch situations. The design expands the range of viable target environments and enhances tunable laser spectrometer performance in extreme and even unpredictable environments. Through rapid prototyping with a commercial RTOS/FPGA platform, we have implemented a fully operational tunable laser spectrometer (using a highly sensitive second harmonic technique). With this prototype, we have demonstrated autonomous real-time adaptivity in the lab with simulated extreme environments.

Rapid sedimentation and overpressure in shallow sediments of the Bering Trough, offshore southern Alaska

NASA Astrophysics Data System (ADS)

Daigle, Hugh; Worthington, Lindsay L.; Gulick, Sean P. S.; Van Avendonk, Harm J. A.

2017-04-01

Pore pressures in sediments at convergent margins play an important role in driving chemical fluxes and controlling deformation styles and localization. In the Bering Trough offshore Southern Alaska, extreme sedimentation rates over the last 140 kyr as a result of glacial advance/retreats on the continental shelf have resulted in elevated pore fluid pressures in slope sediments overlying the Pamplona Zone fold and thrust belt, the accretionary wedge resulting from subduction of the Yakutat microplate beneath the North American Plate. Based on laboratory experiments and downhole logs acquired at Integrated Ocean Drilling Program Site U1421, we predict that the overpressure in the slope sediments may be as high as 92% of the lithostatic stress. Results of one-dimensional numerical modeling accounting for changes in sedimentation rate over the last 130 kyr predicted overpressures that are consistent with our estimates, suggesting that the overpressure is a direct result of the rapid sedimentation experienced on the Bering shelf and slope. Comparisons with other convergent margins indicate that such rapid sedimentation and high overpressure are anomalous in sediments overlying accretionary wedges. We hypothesize that the shallow overpressure on the Bering shelf/slope has fundamentally altered the deformation style within the Pamplona Zone by suppressing development of faults and may inhibit seismicity by focusing faulting elsewhere or causing deformation on existing faults to be aseismic. These consequences are probably long-lived as it may take several million years for the excess pressure to dissipate.

Rapid screening test for gestational diabetes: public health need, market requirement, initial product design, and experimental results

NASA Astrophysics Data System (ADS)

Weigl, Bernhard H.; Zwisler, Greg; Peck, Roger; Abu-Haydar, Elizabeth

2013-03-01

Gestational diabetes is a global epidemic where many urban areas in Southeast Asia have found prevalence rates as high as 20%, exceeding the highest prevalence rates in the developed world. It can have serious and life-threatening consequences for mothers and babies. We are developing two variants of a new, simple, low-cost rapid test for screening for gestational diabetes mellitus for use primarily in low-resource settings. The pair of assays, both semiquantitative rapid diagnostic strip tests for glycated albumin, require neither fasting nor an oral glucose challenge test. One variant is an extremely simple strip test to estimate the level of total glycated albumin in blood. The other, which is slightly more complex and expensive, is a test that determines the ratio of glycated albumin to total albumin. The screening results can be used to refer women to receive additional care during delivery to avoid birth complications as well as counseling on diet and exercise during and after pregnancy. Results with the latter test may also be used to start treatment with glucose-lowering drugs. Both assays will be read visually. We present initial results of a preliminary cost-performance comparison model evaluating the proposed test versus existing alternatives. We also evaluated user needs and schematic paper microfluidics-based designs aimed at overcoming the challenge of visualizing relatively narrow differences between normal and elevated levels of glycated albumin in blood.

Rapid detection of tuberculosis using droplet-based microfluidics

NASA Astrophysics Data System (ADS)

Rosenfeld, Liat; Cheng, Yunfeng; Rao, Jianghong; Tang, Sindy K. Y.

2014-03-01

Tuberculosis is one of the most deadly diseases that kills over one million people each year and infects one-third of the world's population. The disease is spread by infection with Mycobacterium tuberculosis (Mtb). Owing to its airborne transmission, early diagnosis is critical to the prevention and control of TB. Standard diagnostic methods, acid-fast smear from sputum, often do not become positive until after transmission occurs, which allows the spread of the disease. Culture-based techniques are more sensitive, but take weeks to obtain results because of the extremely slow growth rate of Mtb. In this study a new method to detect indicator enzyme based on the isolation of tubercle bacillus in a large number of picoliter droplets combined with a fluorescent probe has been developed. We use BlaC (an enzyme naturally expressed/secreted by tubercle bacilli) as a marker and a designed BlaC-specific fluorogenic substrates as probes for Mtb detection. We present here a new method to detect the indicator enzyme based on the isolation, digitization and concentration of bacteria samples in a large number of picoliter drops. We show that by controlling the size of the droplets we can control the rate of conversion. Hence rapid increase in signal has been observed as the size of the drops has been decreased. Our vision is that this tool will be able to detect tubercle bacilli in a sensitive, rapid, specific and quantitative manner in vitro at a low cost, particularly in resource limited settings where TB is the most prevalent.

High Temperature Extremes - Will They Transform Structure of Avian Assemblages in the Desert Southwest?

NASA Astrophysics Data System (ADS)

Mutiibwa, D.; Albright, T. P.; Wolf, B. O.; Mckechnie, A. E.; Gerson, A. R.; Talbot, W. A.; Sadoti, G.; O'Neill, J.; Smith, E.

2014-12-01

Extreme weather events can alter ecosystem structure and function and have caused mass mortality events in animals. With climate change, high temperature extremes are increasing in frequency and magnitude. To better understand the consequences of climate change, scientists have frequently employed correlative models based on species occurrence records. However, these approaches may be of limited utility in the context of extremes, as these are often outside historical ranges and may involve strong non-linear responses. Here we describe work linking physiological response informed by experimental data to geospatial climate datasets in order to mechanistically model the dynamics of dehydration risk to dessert passerine birds. Specifically, we modeled and mapped the occurrence of current (1980-2013) high temperature extremes and evaporative water loss rates for eight species of passerine birds ranging in size from 6.5-75g in the US Southwest portion of their range. We then explored the implications of a 4° C warming scenario. Evaporative water loss (EWL) across a range of high temperatures was measured in heat-acclimated birds captured in the field. We used the North American Land Data Assimilation System 2 dataset to obtain hourly estimates of EWL with a 14-km spatial grain. Assuming lethal dehydration occurs when water loss reaches 15% of body weight, we then produced maps of total daily EWL and time to lethal dehydration based on both current data and future scenarios. We found that milder events capable of producing dehydration in passerine birds over four or more hours were not uncommon over the Southwest, but rapid dehydration conditions (<3 hours) were rare. Under the warming scenario, the frequency and extent of dehydration events expanded greatly, often affecting areas several times larger than in present-day climate. Dehydration risk was especially high among smaller bodied passerines due to their higher mass-specific rates of water loss. Even after accounting for the moderating effects of microsite and topoclimatic refugia, the increase in occurrence of lethal dehydration risk is cause for concern. In particular, our results suggest that smaller bodied passerines may have difficulty in avoiding extirpation over portions of their current range in the desert southwest.

Air-water oxygen exchange in a large whitewater river

USGS Publications Warehouse

Hall, Robert O.; Kennedy, Theodore A.; Rosi-Marshall, Emma J.

2012-01-01

Air-water gas exchange governs fluxes of gas into and out of aquatic ecosystems. Knowing this flux is necessary to calculate gas budgets (i.e., O2) to estimate whole-ecosystem metabolism and basin-scale carbon budgets. Empirical data on rates of gas exchange for streams, estuaries, and oceans are readily available. However, there are few data from large rivers and no data from whitewater rapids. We measured gas transfer velocity in the Colorado River, Grand Canyon, as decline in O2 saturation deficit, 7 times in a 28-km segment spanning 7 rapids. The O2 saturation deficit exists because of hypolimnetic discharge from Glen Canyon Dam, located 25 km upriver from Lees Ferry. Gas transfer velocity (k600) increased with slope of the immediate reach. k600 was -1 in flat reaches, while k600 for the steepest rapid ranged 3600-7700 cm h-1, an extremely high value of k600. Using the rate of gas exchange per unit length of water surface elevation (Kdrop, m-1), segment-integrated k600 varied between 74 and 101 cm h-1. Using Kdrop we scaled k600 to the remainder of the Colorado River in Grand Canyon. At the scale corresponding to the segment length where 80% of the O2 exchanged with the atmosphere (mean length = 26.1 km), k600 varied 4.5-fold between 56 and 272 cm h-1 with a mean of 113 cm h-1. Gas transfer velocity for the Colorado River was higher than those from other aquatic ecosystems because of large rapids. Our approach of scaling k600 based on Kdrop allows comparing gas transfer velocity across rivers with spatially heterogeneous morphology.

Gene alterations at Drosophila inversion breakpoints provide prima facie evidence for natural selection as an explanation for rapid chromosomal evolution

PubMed Central

2012-01-01

Background Chromosomal inversions have been pervasive during the evolution of the genus Drosophila, but there is significant variation between lineages in the rate of rearrangement fixation. D. mojavensis, an ecological specialist adapted to a cactophilic niche under extreme desert conditions, is a chromosomally derived species with ten fixed inversions, five of them not present in any other species. Results In order to explore the causes of the rapid chromosomal evolution in D. mojavensis, we identified and characterized all breakpoints of seven inversions fixed in chromosome 2, the most dynamic one. One of the inversions presents unequivocal evidence for its generation by ectopic recombination between transposon copies and another two harbor inverted duplications of non-repetitive DNA at the two breakpoints and were likely generated by staggered single-strand breaks and repair by non-homologous end joining. Four out of 14 breakpoints lay in the intergenic region between preexisting duplicated genes, suggesting an adaptive advantage of separating previously tightly linked duplicates. Four out of 14 breakpoints are associated with transposed genes, suggesting these breakpoints are fragile regions. Finally two inversions contain novel genes at their breakpoints and another three show alterations of genes at breakpoints with potential adaptive significance. Conclusions D. mojavensis chromosomal inversions were generated by multiple mechanisms, an observation that does not provide support for increased mutation rate as explanation for rapid chromosomal evolution. On the other hand, we have found a number of gene alterations at the breakpoints with putative adaptive consequences that directly point to natural selection as the cause of D. mojavensis rapid chromosomal evolution. PMID:22296923

Electrostatic Induced Stretch Growth of Homogeneous β-Ni(OH)2 on Graphene with Enhanced High-Rate Cycling for Supercapacitors

PubMed Central

Wu, Zhong; Huang, Xiao-Lei; Wang, Zhong-Li; Xu, Ji-Jing; Wang, Heng-Guo; Zhang, Xin-Bo

2014-01-01

Supercapacitors, as one of alternative energy devices, have been characterized by the rapid rate of charging and discharging, and high power density. But they are now challenged to achieve their potential energy density that is related to specific capacitance. Thus it is extremely important to make such materials with high specific capacitances. In this report, we have gained homogenous Ni(OH)2 on graphene by efficiently using of a facile and effective electrostatic induced stretch growth method. The electrostatic interaction triggers advantageous change in morphology and the ordered stacking of Ni(OH)2 nanosheets on graphene also enhances the crystallization of Ni(OH)2. When the as-prepared Ni(OH)2/graphene composite is applied to supercapacitors, they show superior electrochemical properties including high specific capacitance (1503 F g−1 at 2 mV s−1) and excellent cycling stability up to 6000 cycles even at a high scan rate of 50 mV s−1. PMID:24413283

Molecular evolution and emergence of avian gammacoronaviruses.

PubMed

Jackwood, Mark W; Hall, David; Handel, Andreas

2012-08-01

Coronaviruses, which are single stranded, positive sense RNA viruses, are responsible for a wide variety of existing and emerging diseases in humans and other animals. The gammacoronaviruses primarily infect avian hosts. Within this genus of coronaviruses, the avian coronavirus infectious bronchitis virus (IBV) causes a highly infectious upper-respiratory tract disease in commercial poultry. IBV shows rapid evolution in chickens, frequently producing new antigenic types, which adds to the multiple serotypes of the virus that do not cross protect. Rapid evolution in IBV is facilitated by strong selection, large population sizes and high genetic diversity within hosts, and transmission bottlenecks between hosts. Genetic diversity within a host arises primarily by mutation, which includes substitutions, insertions and deletions. Mutations are caused both by the high error rate, and limited proof reading capability, of the viral RNA-dependent RNA-polymerase, and by recombination. Recombination also generates new haplotype diversity by recombining existing variants. Rapid evolution of avian coronavirus IBV makes this virus extremely difficult to diagnose and control, but also makes it an excellent model system to study viral genetic diversity and the mechanisms behind the emergence of coronaviruses in their natural host. Copyright © 2012 Elsevier B.V. All rights reserved.

Rapid host immune response and viral dynamics in herpes simplex virus-2 infection

PubMed Central

Schiffer, Joshua T; Corey, Lawrence

2014-01-01

Herpes Simplex Virus-2 (HSV-2) is episodically shed throughout the human genital tract. While high viral load correlates with development of genital ulcers, shedding also commonly occurs even when ulcers are not present, allowing for silent transmission during coitus and contributing to high seroprevalence of HSV-2 worldwide. Frequent viral reactivation occurs despite diverse and complementary host and viral mechanisms within ganglionic tissue that predispose towards latency, suggesting that viral replication may be constantly occurring in a small minority of neurons within the ganglia. Within genital mucosa, the in vivo expansion and clearance rates of HSV-2 are extremely rapid. Resident dendritic cells and memory HSV-specific T cells persist at prior sites of genital tract reactivation, and in conjunction with prompt innate recognition of infected cells, lead to rapid containment of infected cells. Shedding episodes vary greatly in duration and severity within a single person over time: this heterogeneity appears best explained by variation in the densities of host immunity across the genital tract. The fact that immune responses usually control viral replication in genital skin prior to development of lesions provides optimism that enhancing such responses could lead to effective vaccines and immunotherapies. PMID:23467247

Getting the Gist of Events: Recognition of Two-Participant Actions from Brief Displays

PubMed Central

Hafri, Alon; Papafragou, Anna; Trueswell, John C.

2013-01-01

Unlike rapid scene and object recognition from brief displays, little is known about recognition of event categories and event roles from minimal visual information. In three experiments, we displayed naturalistic photographs of a wide range of two-participant event scenes for 37 ms and 73 ms followed by a mask, and found that event categories (the event gist, e.g., ‘kicking’, ‘pushing’, etc.) and event roles (i.e., Agent and Patient) can be recognized rapidly, even with various actor pairs and backgrounds. Norming ratings from a subsequent experiment revealed that certain physical features (e.g., outstretched extremities) that correlate with Agent-hood could have contributed to rapid role recognition. In a final experiment, using identical twin actors, we then varied these features in two sets of stimuli, in which Patients had Agent-like features or not. Subjects recognized the roles of event participants less accurately when Patients possessed Agent-like features, with this difference being eliminated with two-second durations. Thus, given minimal visual input, typical Agent-like physical features are used in role recognition but, with sufficient input from multiple fixations, people categorically determine the relationship between event participants. PMID:22984951

Modeling changes in extreme snowfall events in the Central Rocky Mountains Region with the Fully-Coupled WRF-Hydro Modeling System

NASA Astrophysics Data System (ADS)

gochis, David; rasmussen, Roy; Yu, Wei; Ikeda, Kyoko

2014-05-01

Modeling of extreme weather events often require very finely resolved treatment of atmospheric circulation structures in order to produce and localize large magnitudes of moisture fluxes that result in extreme precipitation. This is particularly true for cool season orographic precipitation processes where the representation of landform can significantly influence vertical velocity profiles and cloud moisture entrainment rates. In this work we report on recent progress in high resolution regional climate modeling of the Colorado Headwaters region using an updated version of the Weather Research and Forecasting (WRF) model and a hydrological extension package called WRF-Hydro. Previous work has shown that the WRF-Hydro modeling system forced by high resolution WRF model output can produce credible depictions of winter orographic precipitation and resultant monthly and annual river flows. Here we present results from a detailed study of an extreme springtime snowfall event that occurred along the Colorado Front Range in March of 2003. First an analysis of the simulated streamflows resulting from the melt out of that event are presented followed by an analysis of projected streamflows from the event where the atmospheric forcing in the WRF model is perturbed using the Psuedo-Global-Warming (PGW) perturbation methodology. Results from the impact of warming on total precipitation, snow-rain partitioning and surface hydrological fluxes (evapotranspiration and runoff) will be discussed in the context of how potential changes in temperature impact the amount of precipitation, the phase of precipitation (rain vs. snow) and the timing and amplitude of streamflow responses. It is shown that under the assumptions of the PGW method, intense precipitation rates increase during the event and, more importantly, that more precipitation falls as rain versus snow which significantly amplifies the runoff response from one where runoff is produced gradually to where runoff is more rapidly translated into streamflow values that approach significant flooding risks.

Increasing climate whiplash in 21st century California

NASA Astrophysics Data System (ADS)

Swain, D. L.; Langenbrunner, B.; Neelin, J. D.; Hall, A. D.

2017-12-01

Temperate "Mediterranean" climate regimes across the globe are particularly susceptible to wide swings between drought and flood—of which California's rapid transition from record multi-year dryness between 2012-2016 to extreme wetness during 2016-2017 provides a dramatic example. The wide-ranging human and environmental impacts of this recent "climate whiplash" event in a highly-populated, economically critical, and biodiverse region highlight the importance of understanding weather and climate extremes at both ends of the hydroclimatic spectrum. Previous studies have examined the potential contribution of anthropogenic warming to recent California extremes, but findings to date have been mixed and primarily drought-focused. Here, we use specific historical California flood and drought events as thresholds for quantifying long-term changes in precipitation extremes using a large ensemble of multi-decadal climate model simulations (CESM-LENS). We find that greenhouse gas emissions are already responsible for a detectable increase in both wet and dry extremes across portions of California, and that increasing 21st century "climate whiplash" will likely yield large increases in the frequency of both rapid "dry-to-wet" transitions and severe flood events over a wide range of timescales. This projected intensification of California's hydrological cycle would seriously challenge the region's existing water storage, conveyance, and flood control infrastructure—even absent large changes in mean precipitation.

Miss-distance indicator for tank main guns

NASA Astrophysics Data System (ADS)

Bornstein, Jonathan A.; Hillis, David B.

1996-06-01

Tank main gun systems must possess extremely high levels of accuracy to perform successfully in battle. Under some circumstances, the first round fired in an engagement may miss the intended target, and it becomes necessary to rapidly correct fire. A breadboard automatic miss-distance indicator system was previously developed to assist in this process. The system, which would be mounted on a 'wingman' tank, consists of a charged-coupled device (CCD) camera and computer-based image-processing system, coupled with a separate infrared sensor to detect muzzle flash. For the system to be successfully employed with current generation tanks, it must be reliable, be relatively low cost, and respond rapidly maintaining current firing rates. Recently, the original indicator system was developed further in an effort to assist in achieving these goals. Efforts have focused primarily upon enhanced image-processing algorithms, both to improve system reliability and to reduce processing requirements. Intelligent application of newly refined trajectory models has permitted examination of reduced areas of interest and enhanced rejection of false alarms, significantly improving system performance.

Capture and Genetic Analysis of Circulating Tumor Cells Using a Magnetic Separation Device (Magnetic Sifter).

PubMed

Ooi, Chin Chun; Park, Seung-Min; Wong, Dawson J; Gambhir, Sanjiv S; Wang, Shan X

2017-01-01

Circulating tumor cells (CTCs) are currently widely studied for their potential application as part of a liquid biopsy. These cells are shed from the primary tumor into the circulation, and are postulated to provide insight into the molecular makeup of the actual tumor in a minimally invasive manner. However, they are extremely rare in blood, with typical concentrations of 1-100 in a milliliter of blood; hence, a need exists for a rapid and high-purity method for isolating CTCs from whole blood. Here, we describe the application of a microfabricated magnetic sifter toward isolation of CTCs from whole blood at volumetric flow rates of 10 mL/h, along with the use of a PDMS-based nanowell system for single-cell gene expression profiling. This method allows rapid isolation of CTCs and subsequent integration with downstream genetic profiling methods for clinical applications such as targeted therapy, therapy monitoring, or further biological studies.

Too much of a good thing? Economic growth and human rights, 1960 to 2010.

PubMed

Cole, Wade M

2017-09-01

Despite widespread belief in the benefits of economic growth, some scholars emphasize the potentially negative consequences of growth-and especially rapid growth-for social and political outcomes. Using data for 149 countries between 1960 and 2010, I analyze the effect of economic growth on fundamental human rights conditions. Dynamic random-effects and two-way fixed-effects estimators, both with and without instrumental variables, yield several conclusions. First, economic growth is causally prior to rights conditions. Second, economic growth has a modest positive effect on human rights, albeit with diminishing returns at high growth rates. Third, low-income countries account for much of this relationship: growth improves rights conditions for most low-income countries, but extremely rapid growth is inimical. Growth has little effect among middle-income countries, while for high-income countries the relationship is positive but not robust. I bring these findings to bear on long-standing debates between proponents and critics of modernization theory. Copyright © 2017 Elsevier Inc. All rights reserved.

[Allocation of attentional resource and monitoring processes under rapid serial visual presentation].

PubMed

Nishiura, K

1998-08-01

With the use of rapid serial visual presentation (RSVP), the present study investigated the cause of target intrusion errors and functioning of monitoring processes. Eighteen students participated in Experiment 1, and 24 in Experiment 2. In Experiment 1, different target intrusion errors were found depending on different kinds of letters --romaji, hiragana, and kanji. In Experiment 2, stimulus set size and context information were manipulated in an attempt to explore the cause of post-target intrusion errors. Results showed that as stimulus set size increased, the post-target intrusion errors also increased, but contextual information did not affect the errors. Results concerning mean report probability indicated that increased allocation of attentional resource to response-defining dimension was the cause of the errors. In addition, results concerning confidence rating showed that monitoring of temporal and contextual information was extremely accurate, but it was not so for stimulus information. These results suggest that attentional resource is different from monitoring resource.

Twenty-one-year experience with land mine injuries.

PubMed

Adams, D B; Schwab, C W

1988-01-01

Land mines produce devastating injuries which are usually fatal. In Guantanamo Bay, there have been no survivors from close range, functioning antipersonnel mines of the M-16 series. All 15 antipersonnel mine fatalities suffered extremity amputation. Seven of the 15 patients suffered immediately fatal head, neck, or truncal injuries (Type I injury). The three patients who underwent hospital resuscitation had extremity amputation but were spared major head, neck, or truncal injury. It is in this group of injured that potentially salvageable patients can be identified; for them aggressive rescue and resuscitation must be performed. Those with Type II injuries are the highest priority in any triage plan. In a mass casualty or combat casualty scenario, Type II patients, in particular those with high bilateral above-the-knee amputations, may be reassigned to an expectant treatment category so as to allow the main focus on more salvageable patients. The prehospital management plan emphasizes rapid assessment and triage of patients, use of tourniquets to control extremity hemorrhage, supplemental oxygen or endotracheal intubation if possible, neck immobilization, use of the extremity section of the pneumatic antishock garment if applicable, and rapid transport to a hospital. Hospital management of these patients emphasizes aggressive resuscitation, early endotracheal intubation, and rapid volume replacement with simultaneous balanced salt solution and blood. Operative debridement with broad-spectrum antibiotic coverage and tetanus prophylaxis is performed; wounds are managed in an open fashion and frequently examined at subsequent dates in the operating room.

Ion beam sputter coatings for laser technology

NASA Astrophysics Data System (ADS)

Ristau, Detlev; Gross, Tobias

2005-09-01

The initial motivation for the development of Ion Beam Sputtering (IBS) processes was the need for optical coatings with extremely low optical scatter losses for laser gyros. Especially, backscattering of the gyro-mirrors couples the directional modes in the ring resonator leading to the lock in effect which limits the sensitivity of the gyro. Accordingly, the first patent on IBS was approved for an aircraft company (Litton) in 1978. In the course of the rapid development of the IBS-concept during the last two decades, an extremely high optical quality could be achieved for laser coatings in the VIS- and NIR-spectral region. For example, high reflecting coatings with total optical losses below 1 ppm were demonstrated for specific precision measurement applications with the Nd:YAG-laser operating at 1.064 μm. Even though the high quality level of IBS-coatings had been confirmed in many applications, the process has not found its way into the production environment of most optical companies. Major restrictions are the relatively low rate of the deposition process and the poor lateral homogeneity of the coatings, which are related to the output characteristics of the currently available ion sources. In the present contribution, the basic principles of IBS will be discussed in the context of the demands of modern laser technology. Besides selected examples for special applications of IBS, aspects will be presented for approaches towards rapid manufacturing of coatings and the production of rugate filters on the basis of IBS-techniques.

Source to sink evaluation of sediment routing in the Gulf of Alaska and Southeast Alaska: A thermochronometric perspective

NASA Astrophysics Data System (ADS)

Dunn, Catherine A.; Enkelmann, Eva; Ridgway, Kenneth D.; Allen, Wai K.

2017-03-01

In this study, we present a source to sink evaluation of sediment routing at the glaciated convergent margin in Southeast Alaska. We investigate the efficacy of thermochronology to record spatial and temporal exhumation patterns in synorogenic sediment using Neogene strata drilled by Integrated Ocean Drilling Program Expedition 341 in the Gulf of Alaska. We present 1641 and 529 new detrital zircon and apatite fission track ages, respectively, from strata deposited on the continental shelf, slope, and deep-sea fans. These data are compared to results from the proposed source terrains, including the St. Elias Mountains and new data from the Alsek River. We find that the offshore Bagley-Bering sediment contains grains recording cooling ages much older (80-35 Ma) than those reported from the St. Elias syntaxis (3-2 Ma), indicating that extreme rapid exhumation does not extend west of the Seward-Bagley divide. Data from the sediment on the continental shelf, slope, and proximal deep sea all yield similar results, suggesting the same general source region since 1.2 Ma and limited sediment mixing along this glaciated margin. Data from sediment in the distal deep sea show that extreme, rapid, and deep-seated exhumation was ongoing at 11-8 Ma. Overall, this study demonstrates the strengths and limitations of using detrital fission track thermochronology to understand sediment routing on a glaciated convergent margin and to record changes in exhumation rates over geologic time scales.

Bone characteristics of late-term embryonic and hatchling broilers: bone development under extreme growth rate.

PubMed

Yair, R; Uni, Z; Shahar, R

2012-10-01

The development of broilers is an extreme example of rapid growth, increasing in weight from 40 g at hatch to 2,000 g 5 to 6 wk later. Such rapid growth requires a correspondingly fast development of the skeleton. Bone development is a genetically programmed process that is modified by epigenetic factors, mainly muscle-induced stresses and strains. In this study, we describe the temporal changes in bone morphology and material properties during the prehatch period [embryonic day (E) 14, E17, E19, E21] and posthatch d 3 and 7. The bones were examined for their weight, length, ash content, mechanical properties, and cortical structure. We show that the cross-sectional shape of the tibia and femur changes during the examination period from circular to elliptical. Additionally, the changes in bone properties are time-dependent and nonuniform: from E14 to E17 and from d 3 to 7, fast bone growth was noted, with major increases in both mechanical properties (stiffness, ultimate load, and energy to fracture) and geometric properties (cross-sectional area and thickness, medullary area, and moment of inertia). On the other hand, during the last days of incubation, most mechanical and geometric properties remain unchanged or even decrease. The reasons for this finding may relate to the hatching process but also to mineral shortage during the last days of incubation. This study leads to better understanding of bone development in ovo and posthatch in fast-growing broilers.

[Role of multislice computed tomography in the diagnosis of acute rupture of the thoracic aorta and hepatic artery in a patient with severe concomitant injury].

PubMed

Muslimov, R Sh; Sharifullin, F A; Chernaia, N R; Novruzbekov, M S; Kokov, L S

2015-01-01

Acute traumatic aortic rupture is associated with extremely high mortality rates and requires emergency diagnosis and treatment. This clinical example shows the role of multislice spiral computed tomography in the emergency diagnosis of rupture of two large arterial vessels in severe concomitant injury. It presents the benefits of this rapid and noninvasive imaging technique, an algorithm of the study and the semiotics of injuries in patients with suspected traumatic aortic rupture. The paper also shows the importance of this method in defining treatment policy and then in the assessment of the results of the performed correction.

Necrotizing Fasciitis of the lower extremity: a case report and current concept of diagnosis and management

PubMed Central

Naqvi, GA; Malik, SA; Jan, W

2009-01-01

Necrotizing fasciitis is a severe soft tissue infection characterized by rapidly progressing necrosis, involving subcutaneous tissues. This rare condition carries high mortality rate and require prompt diagnosis and urgent treatment with radical debridement and antibiotics. We describe a case of 21-year old man who presented with the history of trivial injury to the knee. Initially he was admitted and treated for septic arthritis but later was diagnosed as necrotizing fasciitis which was successfully treated with no ill effects what so ever from this devastating condition. This rare condition has been reported in literature but still early diagnosis, which is a key for successful treatment, remains a challenge. PMID:19527519

Conflict on the Sex Chromosomes: Cause, Effect, and Complexity

PubMed Central

Mank, Judith E.; Hosken, David J.; Wedell, Nina

2014-01-01

Intralocus sexual conflict and intragenomic conflict both affect sex chromosome evolution and can in extreme cases even cause the complete turnover of sex chromosomes. Additionally, established sex chromosomes often become the focus of heightened conflict. This creates a tangled relationship between sex chromosomes and conflict with respect to cause and effect. To further complicate matters, sexual and intragenomic conflict may exacerbate one another and thereby further fuel sex chromosome change. Different magnitudes and foci of conflict offer potential explanations for lineage-specific variation in sex chromosome evolution and answer long-standing questions as to why some sex chromosomes are remarkably stable, whereas others show rapid rates of evolutionary change. PMID:25280765

Extreme Metal Music and Anger Processing

PubMed Central

Sharman, Leah; Dingle, Genevieve A.

2015-01-01

The claim that listening to extreme music causes anger, and expressions of anger such as aggression and delinquency have yet to be substantiated using controlled experimental methods. In this study, 39 extreme music listeners aged 18–34 years were subjected to an anger induction, followed by random assignment to 10 min of listening to extreme music from their own playlist, or 10 min silence (control). Measures of emotion included heart rate and subjective ratings on the Positive and Negative Affect Scale (PANAS). Results showed that ratings of PANAS hostility, irritability, and stress increased during the anger induction, and decreased after the music or silence. Heart rate increased during the anger induction and was sustained (not increased) in the music condition, and decreased in the silence condition. PANAS active and inspired ratings increased during music listening, an effect that was not seen in controls. The findings indicate that extreme music did not make angry participants angrier; rather, it appeared to match their physiological arousal and result in an increase in positive emotions. Listening to extreme music may represent a healthy way of processing anger for these listeners. PMID:26052277

Inspirals into a charged black hole

NASA Astrophysics Data System (ADS)

Zhu, Ruomin; Osburn, Thomas

2018-05-01

We model the quasicircular inspiral of a compact object into a more massive charged black hole. Extreme and intermediate mass-ratio inspirals are considered through a small mass-ratio approximation. Reissner-Nordström spacetime is used to describe the charged black hole. The effect of radiation reaction on the smaller body is quantified through calculation of electromagnetic and gravitational energy fluxes via solution of Einstein's and Maxwell's equations. Inspiral trajectories are determined by matching the orbital energy decay rate to the rate of radiative energy dissipation. We observe that inspirals into a charged black hole evolve more rapidly than comparable inspirals into a neutral black hole. Through analysis of a variety of inspiral configurations, we conclude that electric charge is an important effect concerning gravitational wave observations when the charge exceeds the threshold |Q |/M ≳0.071 √{ɛ }, where ɛ is the mass ratio.

Aseptic minimum volume vitrification technique for porcine parthenogenetically activated blastocyst.

PubMed

Lin, Lin; Yu, Yutao; Zhang, Xiuqing; Yang, Huanming; Bolund, Lars; Callesen, Henrik; Vajta, Gábor

2011-01-01

Minimum volume vitrification may provide extremely high cooling and warming rates if the sample and the surrounding medium contacts directly with the respective liquid nitrogen and warming medium. However, this direct contact may result in microbial contamination. In this work, an earlier aseptic technique was applied for minimum volume vitrification. After equilibration, samples were loaded on a plastic film, immersed rapidly into factory derived, filter-sterilized liquid nitrogen, and sealed into sterile, pre-cooled straws. At warming, the straw was cut, the filmstrip was immersed into a 39 degree C warming medium, and the sample was stepwise rehydrated. Cryosurvival rates of porcine blastocysts produced by parthenogenetical activation did not differ from control, vitrified blastocysts with Cryotop. This approach can be used for minimum volume vitrification methods and may be suitable to overcome the biological dangers and legal restrictions that hamper the application of open vitrification techniques.

Surface-distributed low-frequency asynchronous stimulation delays fatigue of stimulated muscles.

PubMed

Maneski, Lana Z Popović; Malešević, Nebojša M; Savić, Andrej M; Keller, Thierry; Popović, Dejan B

2013-12-01

One important reason why functional electrical stimulation (FES) has not gained widespread clinical use is the limitation imposed by rapid muscle fatigue due to non-physiological activation of the stimulated muscles. We aimed to show that asynchronous low-pulse-rate (LPR) electrical stimulation applied by multipad surface electrodes greatly postpones the occurrence of muscle fatigue compared with conventional stimulation (high pulse rate, HPR). We compared the produced force vs. time of the forearm muscles responsible for finger flexion in 2 stimulation protocols, LPR (fL = 10 Hz) and HPR (fH = 40 Hz). Surface-distributed low-frequency asynchronous stimulation (sDLFAS) doubles the time interval before the onset of fatigue (104 ± 80%) compared with conventional synchronous stimulation. Combining the performance of multipad electrodes (increased selectivity and facilitated positioning) with sDLFAS (decreased fatigue) can improve many FES applications in both the lower and upper extremities. Copyright © 2013 Wiley Periodicals, Inc.

Recovery from nonlinear creep provides a window into physics of polymer glasses

NASA Astrophysics Data System (ADS)

Caruthers, James; Medvedev, Grigori

Creep under constant applied stress is one of the most basic mechanical experiments, where it exhibits extremely rich relaxation behavior for polymer glasses. As many as five distinct stages of nonlinear creep are observed, where the rate of creep dramatically slows down, accelerates and then slows down again. Modeling efforts to-date has primarily focused on predicting the intricacies of the nonlinear creep curve. We argue that as much attention should be paid to the creep recovery response, when the stress is removed. The experimental creep recovery curve is smooth, where the rate of recovery is initially quite rapid and then progressively decreases. In contrast, the majority of the traditional constitutive models predict recovery curves that are much too abrupt. A recently developed stochastic constitutive model that takes into account the dynamic heterogeneity of glasses produces a smooth creep recovery response that is consistent with experiment.

Microbial Cells as Biosorbents for Heavy Metals: Accumulation of Uranium by Saccharomyces cerevisiae and Pseudomonas aeruginosa

PubMed Central

Strandberg, Gerald W.; Shumate, Starling E.; Parrott, John R.

1981-01-01

Uranium accumulated extracellularly on the surfaces of Saccharomyces cerevisiae cells. The rate and extent of accumulation were subject to environmental parameters, such as pH, temperature, and interference by certain anions and cations. Uranium accumulation by Pseudomonas aeruginosa occurred intracellularly and was extremely rapid (<10 s), and no response to environmental parameters could be detected. Metabolism was not required for metal uptake by either organism. Cell-bound uranium reached a concentration of 10 to 15% of the dry cell weight, but only 32% of the S. cerevisiae cells and 44% of the P. aeruginosa cells within a given population possessed visible uranium deposits when examined by electron microscopy. Rates of uranium uptake by S. cerevisiae were increased by chemical pretreatment of the cells. Uranium could be removed chemically from S. cerevisiae cells, and the cells could then be reused as a biosorbent. Images PMID:16345691

Effects of Non-equilibrium Solidification on the Material Properties of Brick Silicon for Photovoltaics

NASA Technical Reports Server (NTRS)

Regnault, W. F.; Yoo, K. C.; Soltani, P. K.; Johnson, S. M.

1984-01-01

Silicon ingot growth technologies like the Ubiquitous Crystallization Process (UCP) are solidified within a shaping crucible. The rate at which heat can be lost from this crucible minus the rate at which heat is input from an external source determines the rate at which crystallization will occur. Occasionally, when the process parameters for solidification are exceeded, the normally large multi-centimeter grain size material assocated with the UCP will break down into regions containing extremely small, millimeter or less, grain size material. Accompanying this breakdown in grain growth is the development of so called sinuous grain boundaries. The breakdown in grain growth which results in this type of small grain structure with sinuous boundaries is usually associated with the rapid crystallization that would accompany a system failure. This suggests that there are limits to the growth velocity that one can obtain and still expect to produce material that would possess good photovoltaic properties. It is the purpose to determine the causes behind the breakdown of this material and what parameters will determine the best rates of solidification.

Is there a societal need for decadal local sea level forecasting?

NASA Astrophysics Data System (ADS)

Plag, H.

2010-12-01

Global warming is expected to lead to a significant rise in Global Sea Level (GSL). Even a slow rise in GSL would increase the risks of extreme disasters caused by storm surges and hurricanes in coastal areas with dense urban settlements. Recent risk assessments demonstrate large uncertainties in the plausible range of Local Sea Level (LSL) trajectories. While recent assessments limit the upper end for GSL rise to about 2 m by 2100, palaeo-records show that the Earth system has the capability to produce larger GSL rises. During the last deglaciation, the mean GSL rise was on the order of 1.5 m/Ha (Ha = 100 years) while maximum rates may have exceeded 3 m/Ha. LSL changes deviate significantly from GSL changes and may exceed the global average by a factor of 1.5 or more. Paleo-records may not have sampled the full range of possible future LSL rates: over the last few centuries, humanity has re-engineered the Earth and created states not encountered over the past few million years (e.g., in atmospheric CO2 concentration, ocean acidity, land cover, etc.). For many of the environmental changes, the speed of change is exceptional, too. Under these unparalleled conditions, the response of the climate system may also exceed all rapid responses documented in the paleo-records. Rapid LSL changes unparalleled by those recorded in the paleo-records cannot be excluded. Particularly the LSL-rise contribution of the cryosphere is uncertain: Recent research has shown that dynamic links between climate and cryosphere are becoming more active. Observed recent changes in the ice sheets, ice caps and glaciers indicate that an early onset of significant non-linear responses of the cryosphere cannot be excluded. Current ice models cannot provide reliable long-term predictions of such a dynamic response. The extremely stable GSL experienced by human civilizations during the last 7,000 years has led many to think that sea level changes slowly. However, as recently as during the last deglaciation, rapid LSL changes altered coast lines within decades. But large-scale built environment was absent and the much smaller number of human beings could easily adopt to shifting coast lines. Today, with wide-spread built environment and crucial, potentially polluting infrastructure in coastal zones, rapid changes in coast lines and increased inundation risks during storm surges would be economically and environmentally devastating. In the absence of actionable century-scale GSL and LSL predictions, and in the face of low-probability but extremely high-risk rapid LSL events, there is a growing societal need for forecasts of LSL changes on decadal time scales. To a certain extent, a decadal sea level forecasting service would be comparable to the ongoing sky-watch for near-Earth objects, which aims to provide early detection of the low-probability/high-risk event of a large object approaching Earth. Key elements of a decadal LSL forecasting service would be a Global Cryosphere Watch (GCW) and models capable of assimilating GCW and other observations as a basis for reliable decadel LSL forecasts. Such a service could facilitate mitigation and adaptation where and when necessary. Setting up such a service now would enable the assessment of its predictive capabilities.

Stability and Performance of Rapid-Acting Insulin Analogs Used for Continuous Subcutaneous Insulin Infusion: A Systematic Review

PubMed Central

Kerr, David; Wizemann, Erik; Senstius, Jakob; Zacho, Mette; Ampudia-Blasco, Francisco Javier

2013-01-01

Aim: We review and summarize the literature on the safety and stability of rapid-acting insulin analogs used for continuous subcutaneous insulin infusion (CSII) in patients with diabetes. Methods Two predefined search strategies were systematically implemented to search Medline and the Cochrane Register of Clinical Trials for publications between 1996 and 2012. Results Twenty studies were included in the review: 13 in vitro studies and 7 clinical studies. In vitro studies investigated the effects of extreme CSII conditions (high temperature and mechanical agitation) on the risk of catheter occlusions and insulin stability factors, such as potency, purity, high molecular weight protein content, pH stability, and preservative content (m-cresol, phenol). Under these conditions, the overall stability of rapid-acting insulin analogs was similar for insulin lispro, insulin aspart, and insulin glulisine, although insulin glulisine showed greater susceptibility to insulin precipitation and catheter occlusions. A limited number of clinical trials were identified; this evidence-based information suggests that the rate of catheter occlusions in patients with type 1 diabetes using CSII treatment may vary depending on the rapid-acting analog used. Conclusions Based on a limited amount of available data, the safety, stability, and performance of the three available rapid-acting insulin analogs available for use with CSII were similar. However, there is limited evidence suggesting that the risk of occlusion may vary with the insulin preparation under certain circumstances. PMID:24351186

First-Principles Study of MoO3/Graphene Composite as Cathode Material for High-Performance Lithium-Ion Batteries

NASA Astrophysics Data System (ADS)

Cui, Yanhua; Zhao, Yu; Chen, Hong; Wei, Kaiyuan; Ni, Shuang; Cui, Yixiu; Shi, Siqi

2018-03-01

Using first-principles calculations, we have systematically investigated the adsorption and diffusion behavior of Li in MoO3 bulk, on MoO3 (010) surface and in MoO3/graphene composite. Our results indicate that, in case of MoO3 bulk, Li diffusion barriers in the interlayer and intralayer spaces are 0.55 eV and 0.58 eV respectively, which are too high to warrant fast Lithium-ion charge/discharge processes. While on MoO3 (010) surface, Li exhibits a diffusion barrier as low as 0.07 eV which guarantees an extremely fast Li diffusion rate during charge/discharge cycling. However, in MoO3/graphene monolayer, Li diffusion barrier is at the same level as that on MoO3 (010) surface, which also ensures a very rapid Li charge/discharge rate. The rapid Li charge/discharge rate in this system originates from the removal of the upper dangling O1 atoms which hinder the Li diffusion on the lower MoO3 layer. Besides this, due to the interaction between Li and graphene, the Li average binding energy increases to 0.14 eV compared to its value on MoO3 (010) surface which contributes to a higher voltage. Additionally, the increased ratio of surface area provides more space for Li storage and the capacity of MoO3/graphene composite increases up to 279.2 mAhg-1. The last but not the least, due to the high conductivity of graphene, the conductivity of MoO3/graphene composite enhances greatly which is beneficial for electrode materials. In the light of present results, MoO3/graphene composite exhibits higher voltage, good conductivity, large Li capacity and very rapid Li charge/discharge rate, which prove it as a promising cathode material for high-performance lithium-ion batteries (LIBs).

Butterflies, Black swans and Dragon kings: How to use the Dynamical Systems Theory to build a "zoology" of mid-latitude circulation atmospheric extremes?

NASA Astrophysics Data System (ADS)

Faranda, D.; Yiou, P.; Alvarez-Castro, M. C. M.

2015-12-01

A combination of dynamical systems and statistical techniques allows for a robust assessment of the dynamical properties of the mid-latitude atmospheric circulation. Extremes at different spatial and time scales are not only associated to exceptionally intense weather structures (e.g. extra-tropical cyclones) but also to rapid changes of circulation regimes (thunderstorms, supercells) or the extreme persistence of weather structure (heat waves, cold spells). We will show how the dynamical systems theory of recurrence combined to the extreme value theory can take into account the spatial and temporal dependence structure of the mid-latitude circulation structures and provide information on the statistics of extreme events.

Rapid, high-resolution measurement of leaf area and leaf orientation using terrestrial LiDAR scanning data

USDA-ARS?s Scientific Manuscript database

The rapid evolution of high performance computing technology has allowed for the development of extremely detailed models of the urban and natural environment. Although models can now represent sub-meter-scale variability in environmental geometry, model users are often unable to specify the geometr...

Seed size and its rate of evolution correlate with species diversification across angiosperms

PubMed Central

Miller, Eleanor F.; Papadopulos, Alexander S. T.; Tanentzap, Andrew J.

2017-01-01

Species diversity varies greatly across the different taxonomic groups that comprise the Tree of Life (ToL). This imbalance is particularly conspicuous within angiosperms, but is largely unexplained. Seed mass is one trait that may help clarify why some lineages diversify more than others because it confers adaptation to different environments, which can subsequently influence speciation and extinction. The rate at which seed mass changes across the angiosperm phylogeny may also be linked to diversification by increasing reproductive isolation and allowing access to novel ecological niches. However, the magnitude and direction of the association between seed mass and diversification has not been assessed across the angiosperm phylogeny. Here, we show that absolute seed size and the rate of change in seed size are both associated with variation in diversification rates. Based on the largest available angiosperm phylogenetic tree, we found that smaller-seeded plants had higher rates of diversification, possibly due to improved colonisation potential. The rate of phenotypic change in seed size was also strongly positively correlated with speciation rates, providing rare, large-scale evidence that rapid morphological change is associated with species divergence. Our study now reveals that variation in morphological traits and, importantly, the rate at which they evolve can contribute to explaining the extremely uneven distribution of diversity across the ToL. PMID:28723902

Deep Convolutional Extreme Learning Machine and Its Application in Handwritten Digit Classification

PubMed Central

Yang, Xinyi

2016-01-01

In recent years, some deep learning methods have been developed and applied to image classification applications, such as convolutional neuron network (CNN) and deep belief network (DBN). However they are suffering from some problems like local minima, slow convergence rate, and intensive human intervention. In this paper, we propose a rapid learning method, namely, deep convolutional extreme learning machine (DC-ELM), which combines the power of CNN and fast training of ELM. It uses multiple alternate convolution layers and pooling layers to effectively abstract high level features from input images. Then the abstracted features are fed to an ELM classifier, which leads to better generalization performance with faster learning speed. DC-ELM also introduces stochastic pooling in the last hidden layer to reduce dimensionality of features greatly, thus saving much training time and computation resources. We systematically evaluated the performance of DC-ELM on two handwritten digit data sets: MNIST and USPS. Experimental results show that our method achieved better testing accuracy with significantly shorter training time in comparison with deep learning methods and other ELM methods. PMID:27610128

Deep Convolutional Extreme Learning Machine and Its Application in Handwritten Digit Classification.

PubMed

Pang, Shan; Yang, Xinyi

2016-01-01

In recent years, some deep learning methods have been developed and applied to image classification applications, such as convolutional neuron network (CNN) and deep belief network (DBN). However they are suffering from some problems like local minima, slow convergence rate, and intensive human intervention. In this paper, we propose a rapid learning method, namely, deep convolutional extreme learning machine (DC-ELM), which combines the power of CNN and fast training of ELM. It uses multiple alternate convolution layers and pooling layers to effectively abstract high level features from input images. Then the abstracted features are fed to an ELM classifier, which leads to better generalization performance with faster learning speed. DC-ELM also introduces stochastic pooling in the last hidden layer to reduce dimensionality of features greatly, thus saving much training time and computation resources. We systematically evaluated the performance of DC-ELM on two handwritten digit data sets: MNIST and USPS. Experimental results show that our method achieved better testing accuracy with significantly shorter training time in comparison with deep learning methods and other ELM methods.

Far-infrared data for symbiotic stars. II - The IRAS survey observations

NASA Technical Reports Server (NTRS)

Kenyon, S. J.; Fernandez-Castro, T.; Stencel, R. E.

1988-01-01

IRAS survey data for all known symbiotic binaries are reported. S type systems have 25 micron excesses much larger than those of single red giant stars, suggesting that these objects lose mass more rapidly than do normal giants. D type objects have far-IR colors similar to those of Mira variables, implying mass-loss rate of about 10 to the -6th solar masses/yr. The near-IR extinctions of the D types indicate that their Mira components are enshrouded in optically thick dust shells, while their hot companions lie outside the shells. If this interpretation of the data is correct, then the very red near-IR colors of D type symbiotic stars are caused by extreme amounts of dust absorption rather than dust emission. The small group of D prime objects possesses far-IR colors resembling those of compact planetary nebulae or extreme OH/IR stars. It is speculated that these binaries are not symbiotic stars at all, but contain a hot compact star and an exasymptotic branch giant which is in the process of ejecting a planetary nebula shell.

FastID: Extremely Fast Forensic DNA Comparisons

DTIC Science & Technology

2017-05-19

FastID: Extremely Fast Forensic DNA Comparisons Darrell O. Ricke, PhD Bioengineering Systems & Technologies Massachusetts Institute of...Technology Lincoln Laboratory Lexington, MA USA Darrell.Ricke@ll.mit.edu Abstract—Rapid analysis of DNA forensic samples can have a critical impact on...time sensitive investigations. Analysis of forensic DNA samples by massively parallel sequencing is creating the next gold standard for DNA

Countering Internet Extremism

DTIC Science & Technology

2009-01-01

early stages of the conflict, and secure an information warfare victory. Extremists’ use of the Internet has developed rapidly since the Chechen...activities Countering Internet Extremism By Mr. Timothy L. Thomas Editorial Abstract: The author examines the modern informational environment, and...spite of all of these resources—plus all of the money the west has thrown into information (read Internet ) security—an individual known as Irhabi

Insulin pump treatment in children and adolescents with type 1 diabetes.

PubMed

Hofer, S; Meraner, D; Koehle, J

2012-08-01

Within children and adolescents with type 1 diabetes insulin pump treatment is of increasing interest. Frequency of insulin pump therapy shows a rapid and steep increase in toddlers and young children. Insulin pumps allow a close to physiologic insulin delivery due to basal rates programmed over 24 hours with circadian rhythms taken into account. Furthermore, another advantage of technical devices as insulin pumps is the application of extremely small amounts of insulin, as needed in very young children, with the possibility of titration of infusion rates down to 0.01E/h. Dawn Phenomenon and hypoglycemic events are main indications for insulin pump treatment in children and adolescents. A significant reduction of severe hypoglycemia, especially nocturnal hypoglycemia was shown, whereas a reduction of HbA1c and an improvement of metabolic control has been reported in short term and in some but not all long term studies. Ketoacidosis rate did not increase in insulin pump therapy. Complications due to continuous subcutaneous insulin infusion, like local infections and dermatological changes are frequent but were not associated with glycemic control and did not lead to discontinuation of insulin pump treatment. Pump discontinuation rate in general is low, varying from 1% in very young children up to 6% in pubertal adolescent girls. Insulin pump treatment was shown to be safe and efficient and the simplicity of handling the devices as well as an improvement of quality of life may explain the rapid increase of pump treatment in young children and adolescents with type 1 diabetes.

Rapid changes in cell physiology as a result of acute thermal stress house sparrows, Passer domesticus.

PubMed

Jimenez, Ana G; Williams, Joseph B

2014-12-01

Given that our climate is rapidly changing, Physiological Ecologists have the critical task of identifying characteristics of species that make them either resilient or susceptible to changes in their natural air temperature regime. Because climate change models suggest that heat events will become more common, and in some places more extreme, it is important to consider how extreme heat events might affect the physiology of a species. The implications of more frequent heat wave events for birds have only recently begun to be addressed, however, the impact of these events on the cellular physiology of a species is difficult to assess. We have developed a novel approach using dermal fibroblasts to explore how short-term thermal stress at the whole animal level might affect cellular rates of metabolism. House sparrows, Passer domesticus were separated into a "control group" and a "heat shocked" group, the latter acclimated to 43°C for 24h. We determined the plasticity of cellular thermal responses by assigning a "recovery group" that was heat shocked as above, but then returned to room temperature for 24h. Primary dermal fibroblasts were grown from skin of all treatment groups and the pectoralis muscle was collected. We found that glycolysis (ECAR) and oxygen consumption rates (OCR), measured using a Seahorse XF 96 analyzer, were significantly higher in the fibroblasts from the heat shocked group of House sparrows compared with their control counterparts. Additionally, muscle fiber diameters decreased and, in turn, Na(+)-K(+)-ATPase maximal activity in the muscle significantly increased in heat shocked sparrows compared with birds in the control group. All of these physiological alterations due to short-term heat exposure were reversible within 24h of recovery at room temperature. These results show that acute exposure to heat stress significantly alters the cellular physiology of sparrows, but that this species is plastic enough to recover from such a thermal insult within 24h. Copyright © 2014. Published by Elsevier Ltd.

Spatiotemporal trends in extreme rainfall and temperature indices over Upper Tapi Basin, India

NASA Astrophysics Data System (ADS)

Sharma, Priyank J.; Loliyana, V. D.; S. R., Resmi; Timbadiya, P. V.; Patel, P. L.

2017-12-01

The flood risk across the globe is intensified due to global warming and subsequent increase in extreme temperature and precipitation. The long-term trends in extreme rainfall (1944-2013) and temperature (1969-2012) indices have been investigated at annual, seasonal, and monthly time scales using nonparametric Mann-Kendall (MK), modified Mann-Kendall (MMK), and Sen's slope estimator tests. The extreme rainfall and temperature indices, recommended by the Expert Team on Climate Change Detection Monitoring Indices (ETCCDMI), have been analyzed at finer spatial scales for trend detection. The results of trend analyses indicate decreasing trend in annual total rainfall, significant decreasing trend in rainy days, and increasing trend in rainfall intensity over the basin. The seasonal rainfall has been found to decrease for all the seasons except postmonsoon, which could affect the rain-fed agriculture in the basin. The 1- and 5-day annual maximum rainfalls exhibit mixed trends, wherein part of the basin experiences increasing trend, while other parts experience a decreasing trend. The increase in dry spells and concurrent decrease in wet spells are also observed over the basin. The extreme temperature indices revealed increasing trends in hottest and coldest days, while decreasing trends in coldest night are found over most parts of the basin. Further, the diurnal temperature range is also found to increase due to warming tendency in maximum temperature (T max) at a faster rate compared to the minimum temperature (T min). The increase in frequency and magnitude of extreme rainfall in the basin has been attributed to the increasing trend in maximum and minimum temperatures, reducing forest cover, rapid pace of urbanization, increase in human population, and thereby increase in the aerosol content in the atmosphere. The findings of the present study would significantly help in sustainable water resource planning, better decision-making for policy framework, and setting up infrastructure against flood disasters in Upper Tapi Basin, India.

Soil heating and evaporation under extreme conditions: Forest fires and slash pile burns

NASA Astrophysics Data System (ADS)

Massman, W. J.

2011-12-01

Heating any soil during a sufficiently intense wild fire or prescribed burn can alter soil irreversibly, resulting in many significant and well known, long term biological, chemical, and hydrological effects. To better understand how fire impacts soil, especially considering the increasing probability of wildfires that is being driven by climate change and the increasing use of prescribe burns by land managers, it is important to better understand the dynamics of the coupled heat and moisture transport in soil during these extreme heating events. Furthermore, improving understanding of heat and mass transport during such extreme conditions should also provide insights into the associated transport mechanisms under more normal conditions as well. Here I describe the development of a new model designed to simulate soil heat and moisture transport during fires where the surface heating often ranges between 10,000 and 100,000 Wm-2 for several minutes to several hours. Model performance is tested against laboratory measurements of soil temperature and moisture changes at several depths during controlled heating events created with an extremely intense radiant heater. The laboratory tests employed well described soils with well known physical properties. The model, on the other hand, is somewhat unusual in that it employs formulations for temperature dependencies of the soil specific heat, thermal conductivity, and the water retention curve (relation between soil moisture and soil moisture potential). It also employs a new formulation for the surface evaporation rate as a component of the upper boundary condition, as well as the Newton-Raphson method and the generalized Thomas algorithm for inverting block tri-diagonal matrices to solve for soil temperature and soil moisture potential. Model results show rapid evaporation rates with significant vapor transfer not only to the free atmosphere above the soil, but to lower depths of the soil, where the vapor re-condenses ahead of the heating front. Consequently the trajectory of the solution (soil volumetric water content versus soil temperature) is very unusual and highly nonlinear, which may explain why more traditional methods (i.e., those based on finite difference or finite element approaches) tend to show more numerical instabilities than the Newton-Raphson method when used to model these extreme conditions. But, despite the intuitive and qualitative appeal of the model's numerical solution, it underestimates the rate of soil moisture loss observed during the laboratory trials, although the soil temperatures are reasonably well simulated.

Isotopic constraints on crustal growth and recycling

NASA Technical Reports Server (NTRS)

Jacobsen, Stein B.

1988-01-01

The Sm-Nd isotopic data on clastic and chemical sediments are used with the present-day age distribution of continental crustal rocks to estimate the rates of crustal accretion, growth and recycling throughout earth's history. A new method for interpreting Nd model ages on both chemical and clastic sediments is proposed. A general relationship is derived between the mean crustal residence time of material recycled from the crust to the mantle (i.e., sediments), the mean age of the crust, and the crustal growth and recycling rates. This relationship takes into account the fact that the age distribution of material in the continental crust is generally different from the age distribution of material recycled into the mantle. The episodic nature of the present-day age distribution in crustal rocks results in similar episodicity in the accretion and recycling rates. The results suggest that by about 3.8 Ga ago, about 40 percent of the present continental volume was present. Recycling rates were extremely high 3-4 Ga ago and declined rapidly to an insignificant value of about 0.1 cu km/a during most of the Phanerozoic. The Nd model age pattern on sediments suggests a fairly high rate of growth during the Phanerozoic.

Puerperal group A streptococcal infection: beyond Semmelweis.

PubMed

Anderson, Brenna L

2014-04-01

Ignaz Semmelweiss made one of the most important contributions to modern medicine when he instituted handwashing in an obstetric clinic in Austria in 1847, decreasing mortality there from more than 10% to 2%. Unfortunately, puerperal sepsis remains a leading cause of maternal mortality throughout the world. Group A streptococcus (GAS), Streptococcus pyogenes, is an organism associated with high rates of morbidity and mortality from puerperal infections. When associated with sepsis, known as streptococcal toxic shock syndrome, mortality rates approach 30-50%. Group A streptococcus can cause invasive infections in the form of endometritis, necrotizing fasciitis, or streptococcal toxic shock syndrome. The clinical presentation of women with puerperal GAS infections is often atypical with extremes of temperature, unusual and vague pain, and pain in extremities. Toxin production by the organism may allow GAS to spread across tissue planes and cause necrosis while evading containment by the maternal immune system in the form of a discrete abscess. Endometrial aspiration in addition to blood cultures may be a useful rapid diagnostic tool. Imaging may appear normal and should not dissuade the clinician from aggressive management. When suspected, invasive GAS infections should be treated emergently with fluid resuscitation, antibiotic administration, and source control. The optimal antibiotic regimen contains penicillin and clindamycin. Source control may require extensive wound or vulvar debridement, hysterectomy, or a combination of these, which may be life-saving. The benefit of immunoglobulins in management of puerperal GAS infections is unclear.

Gravitational Waves From the Kerr/CFT Correspondence

NASA Astrophysics Data System (ADS)

Porfyriadis, Achilleas

Astronomical observation suggests the existence of near-extreme Kerr black holes in the sky. Properties of diffeomorphisms imply that dynamics of the near-horizon region of near-extreme Kerr are governed by an infinite-dimensional conformal symmetry. This symmetry may be exploited to analytically, rather than numerically, compute a variety of potentially observable processes. In this thesis we compute the gravitational radiation emitted by a small compact object that orbits in the near-horizon region and plunges into the horizon of a large rapidly rotating black hole. We study the holographically dual processes in the context of the Kerr/CFT correspondence and find our conformal field theory (CFT) computations in perfect agreement with the gravity results. We compute the radiation emitted by a particle on the innermost stable circular orbit (ISCO) of a rapidly spinning black hole. We confirm previous estimates of the overall scaling of the power radiated, but show that there are also small oscillations all the way to extremality. Furthermore, we reveal an intricate mode-by-mode structure in the flux to infinity, with only certain modes having the dominant scaling. The scaling of each mode is controlled by its conformal weight. Massive objects in adiabatic quasi-circular inspiral towards a near-extreme Kerr black hole quickly plunge into the horizon after passing the ISCO. The post-ISCO plunge trajectory is shown to be related by a conformal map to a circular orbit. Conformal symmetry of the near-horizon region is then used to compute analytically the gravitational radiation produced during the plunge phase. Most extreme-mass-ratio-inspirals of small compact objects into supermassive black holes end with a fast plunge from an eccentric last stable orbit. We use conformal transformations to analytically solve for the radiation emitted from various fast plunges into extreme and near-extreme Kerr black holes.

Temporal dynamics of CO 2 and CH 4 loss potentials in response to rapid hydrological shifts in tidal freshwater wetland soils

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

RoyChowdhury, Taniya; Bramer, Lisa; Hoyt, David W.

tEarth System Models predict climate extremes that will impact regional and global hydrology. Aquatic-terrestrial transition zones like wetlands are subjected to the immediate consequence of climate change with shifts in the magnitude and dynamics of hydrologic flow. Such fluctuating hydrology can alterthe nature and rate of biogeochemical transformations and significantly impact the carbon balance ofthe ecosystem. We tested the impacts of fluctuating hydrology and, specifically, the role of antecedentmoisture conditions in determining the dominant carbon loss mechanisms in soils sampled from a tidalfreshwater wetland system in the lower Columbia River, WA, USA. Our objective was to understand shiftsin biogeochemical processesmore » in response to changing soil moisture, based on soil respiration and methaneproduction rates, and to elucidate such responses based on the observed electron acceptor and metaboliteprofiles under laboratory conditions. Metabolomics and biogeochemical process rates provided evidencethat soil redox was the principal factor driving metabolic function. Fluctuating redox conditions alteredterminal electron acceptor and donor availability and recovery strengths of their concentrations in soilsuch that a disproportionate release of carbon dioxide stemmed from alternative anaerobic degradationprocesses like sulfate and iron reduction compared to carbon loss due to methanogenesis. Our resultsshow that extended and short-term saturation created conditions conducive to increasing metaboliteavailability for anaerobic decomposition processes, with a significant lag in methanogenesis. In contrast,extended drying caused a cellular-level stress response and rapid recycling of alternate electron acceptors.« less

Temporal dynamics of CO2and CH4 loss potentials in response to rapid hydrological shifts in tidal freshwater wetland soils

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

Roy Chowdhury, Taniya; Bramer, Lisa M.; Hoyt, Davi

2018-04-15

tEarth System Models predict climate extremes that will impact regional and global hydrology. Aquatic-terrestrial transition zones like wetlands are subjected to the immediate consequence of climate change with shifts in the magnitude and dynamics of hydrologic flow. Such fluctuating hydrology can alterthe nature and rate of biogeochemical transformations and significantly impact the carbon balance ofthe ecosystem. We tested the impacts of fluctuating hydrology and, specifically, the role of antecedentmoisture conditions in determining the dominant carbon loss mechanisms in soils sampled from a tidalfreshwater wetland system in the lower Columbia River, WA, USA. Our objective was to understand shiftsin biogeochemical processesmore » in response to changing soil moisture, based on soil respiration and methaneproduction rates, and to elucidate such responses based on the observed electron acceptor and metaboliteprofiles under laboratory conditions. Metabolomics and biogeochemical process rates provided evidencethat soil redox was the principal factor driving metabolic function. Fluctuating redox conditions alteredterminal electron acceptor and donor availability and recovery strengths of their concentrations in soilsuch that a disproportionate release of carbon dioxide stemmed from alternative anaerobic degradationprocesses like sulfate and iron reduction compared to carbon loss due to methanogenesis. Our resultsshow that extended and short-term saturation created conditions conducive to increasing metaboliteavailability for anaerobic decomposition processes, with a significant lag in methanogenesis. In contrast,extended drying caused a cellular-level stress response and rapid recycling of alternate electron acceptors.« less

Predicting dietborne metal toxicity from metal influxes

USGS Publications Warehouse

Croteau, M.-N.; Luoma, S.N.

2009-01-01

Dietborne metal uptake prevails for many species in nature. However, the links between dietary metal exposure and toxicity are not well understood. Sources of uncertainty include the lack of suitable tracers to quantify exposure for metals such as copper, the difficulty to assess dietary processes such as food ingestion rate, and the complexity to link metal bioaccumulation and effects. We characterized dietborne copper, nickel, and cadmium influxes in a freshwater gastropod exposed to diatoms labeled with enriched stable metal isotopes. Metal influxes in Lymnaea stagnalis correlated linearly with dietborne metal concentrations over a range encompassing most environmental exposures. Dietary Cd and Ni uptake rate constants (kuf) were, respectively, 3.3 and 2.3 times higher than that for Cu. Detoxification rate constants (k detox) were similar among metals and appeared 100 times higher than efflux rate constants (ke). Extremely high Cu concentrations reduced feeding rates, causing the relationship between exposure and influx to deviate from linearity; i.e., Cu uptake rates leveled off between 1500 and 1800 nmol g-1 day-1. L. stagnalis rapidly takes up Cu, Cd, and Ni from food but detoxifies the accumulated metals, instead of reducing uptake or intensifying excretion. Above a threshold uptake rate, however, the detoxification capabilities of L. stagnalis are overwhelmed.

Thermotolerance and Photosystem II Behaviour in Co-occuring Temperate Tree Species Exposed to Short-term Extreme Heat Waves

NASA Astrophysics Data System (ADS)

Guha, A.; Warren, J.; Cummings, C.; Han, J.

2017-12-01

Thermal stress can induce irreversible photodamage with longer consequences for plant metabolism. We focused on photosystem II (PSII) behaviour to understand how this complex responds in different co-occuring temperate trees exposed to short-term extreme heat waves. The study was designed for understanding complex heat tolerance mechanisms in trees. During manipulative heat-wave experiments, we monitored instantaneous PSII performance and tracked both transient and chronic PSII damages using chlorophyll a fluorescence characteristics. Fluorescence signals were used to simulate PSII bioenergetic processes. The light (Fv'/Fm') and dark-adapted (Fv/Fm) fluorescence traits including fast induction kinetics (OJIP), electron transport rate, PSII operating efficiency and quenching capacities were significantly affected by the heat treatments. Loss in PSII efficiency was more apparent in species like black cottonwood, yellow poplar, walnuts and conifers, whereas oaks maintained relatively better PSII functions. The post-heat recovery of Fv/Fm varied across the studied species showing differential carry over effects. PSII down-regulation was one of dominant factors for the loss in operational photosynthesis during extreme heat wave events. Both light and dark-adapted fluorescence characteristics showed loss in photo-regulatory functions and photodamage. Some resilient species showed rapid recovery from transient PSII damage, whereas fingerprints of chronic PSII damage were observed in susceptibles. Thresholds for Fv/Fm and non-photochemical quenching were identified for the studied species. PSII malfunctioning was largely associated with the observed photosynthetic down-regulation during heat wave treatments, however, its physiological recovery should be a key factor to determine species resilience to short-term extreme heat wave events.

Case study: Rainfall partitioning across a natural-to-urban forest gradient during an extreme rain event

NASA Astrophysics Data System (ADS)

Akin, B. H.; Van Stan, J. T., II; Cote, J. F.; Jarvis, M. T.; Underwood, J.; Friesen, J.; Hildebrandt, A.; Maldonado, G.

2017-12-01

Trees' partitioning of rainfall is an important first process along the rainfall-to-runoff pathway that has economically significant influences on urban stormwater management. However, important knowledge gaps exist regarding (1) its role during extreme storms and (2) how this role changes as forest structure is altered by urbanization. Little research has been conducted on canopy rainfall partitioning during large, intense storms, likely because canopy water storage is rapidly overwhelmed (i.e., 1-3 mm) by short duration events exceeding, for example, 80 mm of rainfall. However, canopy structure controls more than just storage; it also affects the time for rain to drain to the surface (becoming throughfall) and the micrometeorological conditions that drive wet canopy evaporation. In fact, observations from an example extreme ( 100 mm with maximum 5-minute intensities exceeding 55 mm/h) storm across a urban-to-natural gradient in pine forests in southeast Georgia (USA), show that storm intensities were differentially dampened by 33% (tree row), 28% (forest fragment), and 17% (natural forests). In addition, maximum wet canopy evaporation rates were higher for the exposed tree row (0.18 mm/h) than for the partially-enclosed fragment canopy (0.14 mm/h) and the closed canopy natural forest site (0.11). This resulted in interception percentages decreasing from urban-to-natural stand structures (25% to 16%). A synoptic analysis of the extreme storm in this case study also shows that the mesoscale meteorological conditions that developed the heavy rainfall is expected to occur more often with projected climate changes.

A High-Resolution Chronology of Rapid Forest Transitions following Polynesian Arrival in New Zealand

PubMed Central

McWethy, David B.; Wilmshurst, Janet M.; Whitlock, Cathy; Wood, Jamie R.; McGlone, Matt S.

2014-01-01

Human-caused forest transitions are documented worldwide, especially during periods when land use by dense agriculturally-based populations intensified. However, the rate at which prehistoric human activities led to permanent deforestation is poorly resolved. In the South Island, New Zealand, the arrival of Polynesians c. 750 years ago resulted in dramatic forest loss and conversion of nearly half of native forests to open vegetation. This transformation, termed the Initial Burning Period, is documented in pollen and charcoal records, but its speed has been poorly constrained. High-resolution chronologies developed with a series of AMS radiocarbon dates from two lake sediment cores suggest the shift from forest to shrubland occurred within decades rather than centuries at drier sites. We examine two sites representing extreme examples of the magnitude of human impacts: a drier site that was inherently more vulnerable to human-set fires and a wetter, less burnable site. The astonishing rate of deforestation at the hands of small transient populations resulted from the intrinsic vulnerability of the native flora to fire and from positive feedbacks in post-fire vegetation recovery that increased landscape flammability. Spatially targeting burning in highly-flammable seral vegetation in forests rarely experiencing fire was sufficient to create an alternate fire-prone stable state. The New Zealand example illustrates how seemingly stable forest ecosystems can experience rapid and permanent conversions. Forest loss in New Zealand is among the fastest ecological transitions documented in the Holocene; yet equally rapid transitions can be expected in present-day regions wherever positive feedbacks support alternate fire-inhibiting, fire-prone stable states. PMID:25372150

HOXB4 overexpression mediates very rapid stem cell regeneration and competitive hematopoietic repopulation.

PubMed

Antonchuk, J; Sauvageau, G; Humphries, R K

2001-09-01

Hox transcription factors have emerged as important regulators of hematopoiesis. In particular, we have shown that overexpression of HOXB4 in mouse bone marrow can greatly enhance the level of hematopoietic stem cell (HSC) regeneration achieved at late times (> 4 months) posttransplantation. The objective of this study was to resolve if HOXB4 increases the rate and/or duration of HSC regeneration, and also to see if this enhancement was associated with impaired production of end cells or would lead to competitive reconstitution of all compartments. Retroviral vectors were generated with the GFP reporter gene +/- HOXB4 to enable the isolation and direct tracking of transduced cells in culture or following transplantation. Stem cell recovery was measured by limit dilution assay for long-term competitive repopulating cells (CRU). HOXB4-overexpressing cells have enhanced growth in vitro, as demonstrated by their rapid dominance in mixed cultures and their shortened population doubling time. Furthermore, HOXB4-transduced cells have a marked competitive repopulating advantage in vivo in both primitive and mature compartments. CRU recovery in HOXB4 recipients was extremely rapid, reaching 25% of normal by 14 days posttransplant or some 80-fold greater than control transplant recipients, and attaining normal numbers by 12 weeks. Mice transplanted with even higher numbers of HOXB4-transduced CRU regenerated up to but not beyond the normal CRU levels. HOXB4 is a potent enhancer of primitive hematopoietic cell growth, likely by increasing self-renewal probability but without impairing homeostatic control of HSC population size or the rate of production and maintenance of mature end cells.

Rapid mitochondrial adjustments in response to short-term hypoxia and re-oxygenation in the Pacific oyster, Crassostrea gigas.

PubMed

Sussarellu, Rossana; Dudognon, Tony; Fabioux, Caroline; Soudant, Philippe; Moraga, Dario; Kraffe, Edouard

2013-05-01

As oxygen concentrations in marine coastal habitats can fluctuate rapidly and drastically, sessile marine organisms such as the oyster Crassostrea gigas can experience marked and rapid oxygen variations. In this study, we investigated the responses of oyster gill mitochondria to short-term hypoxia (3 and 12 h, at 1.7 mg O2 l(-1)) and subsequent re-oxygenation. Mitochondrial respiratory rates (states 3 and 4 stimulated by glutamate) and phosphorylation efficiency [respiratory control ratio (RCR) and the relationship between ADP and oxygen consumption (ADP/O)] were measured. Cytochrome c oxidase (CCO) activity and cytochrome concentrations (a, b, c1 and c) were measured to investigate the rearrangements of respiratory chain subunits. The potential implication of an alternative oxidase (AOX) was investigated using an inhibitor of the respiratory chain (antimycin A) and through gene expression analysis in gills and digestive gland. Results indicate a downregulation of mitochondrial capacity, with 60% inhibition of respiratory rates after 12 h of hypoxia. RCR remained stable, while ADP/O increased after 12 h of hypoxia and 1 h of re-oxygenation, suggesting increased phosphorylation efficiency. CCO showed a fast and remarkable increase of its catalytic activity only after 3 h of hypoxia. AOX mRNA levels showed similar patterns in gills and digestive gland, and were upregulated after 12 and 24 h of hypoxia and during re-oxygenation. Results suggest a set of controls regulating mitochondrial functions in response to oxygen fluctuations, and demonstrate the fast and extreme plasticity of oyster mitochondria in response to oxygen variations.

Step length after discrete perturbation predicts accidental falls and fall-related injury in elderly people with a range of peripheral neuropathy.

PubMed

Allet, Lara; Kim, Hogene; Ashton-Miller, James; De Mott, Trina; Richardson, James K

2014-01-01

Distal symmetric polyneuropathy increases fall risk due to inability to cope with perturbations. We aimed to 1) identify the frontal plane lower limb sensorimotor functions which are necessary for robustness to a discrete, underfoot perturbation during gait; and 2) determine whether changes in the post-perturbed step parameters could distinguish between fallers and non fallers. Forty-two subjects (16 healthy old and 26 with diabetic PN) participated. Frontal plane lower limb sensorimotor functions were determined using established laboratory-based techniques. The subjects' most extreme alterations in step width or step length in response to a perturbation were measured. In addition, falls and fall-related injuries were prospectively recorded. Ankle proprioceptive threshold (APrT; p=.025) and hip abduction rate of torque generation (RTG; p=.041) independently predicted extreme step length after medial perturbation, with precise APrT and greater hip RTG allowing maintenance of step length. Injured subjects demonstrated greater extreme step length changes after medial perturbation than non-injured subjects (percent change = 18.5 ± 9.2 vs. 11.3 ± 4.57; p = .01). The ability to rapidly generate frontal plane hip strength and/or precisely perceive motion at the ankle is needed to maintain a normal step length after perturbation, a parameter which distinguishes between subjects sustaining a fall-related injury and those who did not. © 2014.

Decoupling of microbial carbon, nitrogen, and phosphorus cycling in response to extreme temperature events

PubMed Central

Mooshammer, Maria; Hofhansl, Florian; Frank, Alexander H.; Wanek, Wolfgang; Hämmerle, Ieda; Leitner, Sonja; Schnecker, Jörg; Wild, Birgit; Watzka, Margarete; Keiblinger, Katharina M.; Zechmeister-Boltenstern, Sophie; Richter, Andreas

2017-01-01

Predicted changes in the intensity and frequency of climate extremes urge a better mechanistic understanding of the stress response of microbially mediated carbon (C) and nutrient cycling processes. We analyzed the resistance and resilience of microbial C, nitrogen (N), and phosphorus (P) cycling processes and microbial community composition in decomposing plant litter to transient, but severe, temperature disturbances, namely, freeze-thaw and heat. Disturbances led temporarily to a more rapid cycling of C and N but caused a down-regulation of P cycling. In contrast to the fast recovery of the initially stimulated C and N processes, we found a slow recovery of P mineralization rates, which was not accompanied by significant changes in community composition. The functional and structural responses to the two distinct temperature disturbances were markedly similar, suggesting that direct negative physical effects and costs associated with the stress response were comparable. Moreover, the stress response of extracellular enzyme activities, but not that of intracellular microbial processes (for example, respiration or N mineralization), was dependent on the nutrient content of the resource through its effect on microbial physiology and community composition. Our laboratory study provides novel insights into the mechanisms of microbial functional stress responses that can serve as a basis for field studies and, in particular, illustrates the need for a closer integration of microbial C-N-P interactions into climate extremes research. PMID:28508070

Step length after discrete perturbation predicts accidental falls and fall-related injury in elderly people with a range of peripheral neuropathy

PubMed Central

Allet, L; Kim, H; Ashton-Miller, JA; De Mott, T; Richardson, JK

2013-01-01

Aims Distal symmetric polyneuropathy increases fall risk due to inability to cope with perturbations. We aimed to 1) identify the frontal plane lower limb sensorimotor functions which are necessary for robustness to a discrete, underfoot perturbation during gait; and 2) determine whether changes in the post-perturbed step parameters could distinguish between fallers and non fallers. Methods Forty-two subjects (16 healthy old and 26 with diabetic PN) participated. Frontal plane lower limb sensorimotor functions were determined using established laboratory-based techniques. The subjects' most extreme alterations in step width or step length in response to a perturbation were measured. In addition, falls and fall-related injuries were prospectively recorded. Results Ankle proprioceptive threshold (APrT; p=.025) and hip abduction rate of torque generation (RTG; p=.041) independently predicted extreme step length after medial perturbation, with precise APrT and greater hip RTG allowing maintenance of step length. Fallers demonstrated greater extreme step length changes after medial perturbation than non fallers (percent change = 16.41±8.42 vs 11.0±4.95; p=.06) Conclusions The ability to rapidly generate frontal plane hip strength and/or precisely perceive motion at the ankle is needed to maintain a normal step length after perturbation, a parameter, which distinguishes between fallers and non fallers. PMID:24183899

Halo abundance and assembly history with extreme-axion wave dark matter at z ≥ 4

NASA Astrophysics Data System (ADS)

Schive, Hsi-Yu; Chiueh, Tzihong

2018-01-01

Wave dark matter (ψDM) composed of extremely light bosons (mψ ˜ 10 - 22 eV), with quantum pressure suppressing structures below a kpc-scale de Broglie wavelength, has become a viable dark matter candidate. Compared to the conventional free-particle ψDM (FPψDM), the extreme-axion ψDM model (EAψDM) proposed by Zhang & Chiueh features a larger cut-off wavenumber and a broad spectral bump in the matter transfer function. Here, we conduct cosmological simulations to compare the halo abundances and assembly histories at z = 4-11 between three different scenarios: FPψDM, EAψDM and cold dark matter (CDM). We show that EAψDM produces significantly more abundant low-mass haloes than FPψDM with the same mψ, and therefore could alleviate the tension in mψ required by the Lyα forest data and by the kpc-scale dwarf galaxy cores. We also find that, compared to the CDM counterparts, massive EAψDM haloes are, on average, 3-4 times more massive at z = 10-11 due to their earlier formation, undergo a slower mass accretion at 7 ≲ z ≲ 11, and then show a rapidly rising major merger rate exceeding CDM by ˜ 50 per cent at 4 ≲ z ≲ 7. This fact suggests that EAψDM haloes may exhibit more prominent starbursts at z ≲ 7.

Distant Galaxy Clusters Hosting Extreme Central Galaxies

NASA Astrophysics Data System (ADS)

McDonald, Michael

2014-09-01

The recently-discovered Phoenix cluster harbors the most star-forming central cluster galaxy of any cluster in the known Universe, by nearly a factor of 10. This extreme system appears to be fulfilling early cooling flow predictions, although the lack of similar systems makes any interpretation difficult. In an attempt to find other "Phoenix-like" clusters, we have cross-correlated archival all-sky surveys (in which Phoenix was detected) and isolated 4 similarly-extreme systems which are also coincident in position and redshift with an overdensity of red galaxies. We propose here to obtain Chandra observations of these extreme, Phoenix-like systems, in order to confirm them as relaxed, rapidly-cooling galaxy clusters.

Acidic Ribosomal Proteins from the Extreme ’Halobacterium cutirubrum’,

DTIC Science & Technology

the extreme halophilic bacterium, Halobacterium cutirubrum. The identification of the protein moieties involved in these and other interactions in...the halophile ribosome requires a rapid and reproducible screening method for the separation, enumeration and identification of these acidic...polypeptides in the complex ribosomal protein mixtures. In this paper the authors present the results of analyses of the halophile ribosomal proteins using a

Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments

NASA Astrophysics Data System (ADS)

Chang, J. C.; Lockner, D. A.; Reches, Z.

2012-12-01

We simulated the slip of a fault-patch during a large earthquake by rapidly loading an experimental, ring-shaped fault with energy stored in a spinning flywheel. The flywheel abruptly delivers a finite amount of energy by spinning the fault-patch that spontaneously dissipates the energy without operator intervention. We conducted 42 experiments on Sierra White granite (SWG) samples, and 24 experiments on Kasota dolomite (KD) samples. Each experiment starts by spinning a 225 kg disk-shaped flywheel to a prescribed angular velocity. We refer to this experiment as an "earthquake-like slip-event" (ELSE). The strength-evolution in ELSE experiments is similar to the strength-evolution proposed for earthquake models and observed in stick-slip experiments. Further, we found that ELSE experiments are similar to earthquakes in at least three ways: (1) slip driven by the release of a finite amount of stored energy; (2) pattern of fault strength evolution; and (3) seismically observed values, such as average slip, peak-velocity and rise-time. By assuming that the measured slip, D, in ELSE experiments is equivalent to the average slip during an earthquake, we found that ELSE experiments (D = 0.003-4.6 m) correspond to earthquakes in moment-magnitude range of Mw = 4-8. In ELSE experiments, the critical-slip-distance, dc, has mean values of 2.7 cm and 1.2 cm for SWG and KD, that are much shorter than the 1-10 m in steady-state classical experiments in rotary shear systems. We attribute these dc values, to ELSE loading in which the fault-patch is abruptly loaded by impact with a spinning flywheel. Under this loading, the friction-velocity relations are strikingly different from those under steady-state loading on the same rock samples with the same shear system (Reches and Lockner, Nature, 2010). We further note that the slip acceleration in ELSE evolves systematically with fault strength and wear-rate, and that the dynamic weakening is restricted to the period of intense acceleration (up to 25 m/s2 during ~0.1 s). Thus, the weakening distance, dc, is reached within the initial acceleration spike. These observations are not unique, and similar weakening-acceleration associations were reported in stick-slip, rotary shear, and impact shear experiments. These studies greatly differ from each other in slip distance, normal stress, acceleration, and slip-velocities with the outstanding commonality of abrupt loading and intense acceleration. We propose that impact loading induces extremely high strain-rates that significantly increase rock brittleness, fracture tendency, and fragmentation. We envision that these processes intensify fault wear as manifested in ELSE experiments by extremely high initial wear-rates. This intense, early wear generates a layer of fine-grain gouge that reduces the fault strength by powder-lubrication. Our analysis indicates that rapid acceleration associated with earthquake rupture accelerates fault weakening and shortens the weakening-distance.

Is It Time for Synthetic Biodiversity Conservation?

PubMed

Piaggio, Antoinette J; Segelbacher, Gernot; Seddon, Philip J; Alphey, Luke; Bennett, Elizabeth L; Carlson, Robert H; Friedman, Robert M; Kanavy, Dona; Phelan, Ryan; Redford, Kent H; Rosales, Marina; Slobodian, Lydia; Wheeler, Keith

2017-02-01

Evidence indicates that, despite some critical successes, current conservation approaches are not slowing the overall rate of biodiversity loss. The field of synthetic biology, which is capable of altering natural genomes with extremely precise editing, might offer the potential to resolve some intractable conservation problems (e.g., invasive species or pathogens). However, it is our opinion that there has been insufficient engagement by the conservation community with practitioners of synthetic biology. We contend that rapid, large-scale engagement of these two communities is urgently needed to avoid unintended and deleterious ecological consequences. To this point we describe case studies where synthetic biology is currently being applied to conservation, and we highlight the benefits to conservation biologists from engaging with this emerging technology. Published by Elsevier Ltd.

Design, implementation and migration of security systems as an extreme project.

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

Scharmer, Carol; Trujillo, David

2010-08-01

Decision Trees, algorithms, software code, risk management, reports, plans, drawings, change control, presentations, and analysis - all useful tools and efforts but time consuming, resource intensive, and potentially costly for projects that have absolute schedule and budget constraints. What are necessary and prudent efforts when a customer calls with a major security problem that needs to be fixed with a proven, off-the-approval-list, multi-layered integrated system with high visibility and limited funding and expires at the end of the Fiscal Year? Whether driven by budget cycles, safety, or by management decree, many such projects begin with generic scopes and funding allocatedmore » based on a rapid management 'guestimate.' Then a Project Manager (PM) is assigned a project with a predefined and potentially limited scope, compressed schedule, and potentially insufficient funding. The PM is tasked to rapidly and cost effectively coordinate a requirements-based design, implementation, test, and turnover of a fully operational system to the customer, all while the customer is operating and maintaining an existing security system. Many project management manuals call this an impossible project that should not be attempted. However, security is serious business and the reality is that rapid deployment of proven systems via an 'Extreme Project' is sometimes necessary. Extreme Projects can be wildly successful but require a dedicated team of security professionals lead by an experienced project manager using a highly-tailored and agile project management process with management support at all levels, all combined with significant interface with the customer. This paper does not advocate such projects or condone eliminating the valuable analysis and project management techniques. Indeed, having worked on a well-planned project provides the basis for experienced team members to complete Extreme Projects. This paper does, however, provide insight into what it takes for projects to be successfully implemented and accepted when completed under extreme conditions.« less

Design implementation and migration of security systems as an extreme project.

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

Scharmer, Carol

2010-10-01

Decision Trees, algorithms, software code, risk management, reports, plans, drawings, change control, presentations, and analysis - all useful tools and efforts but time consuming, resource intensive, and potentially costly for projects that have absolute schedule and budget constraints. What are necessary and prudent efforts when a customer calls with a major security problem that needs to be fixed with a proven, off-the-approval-list, multi-layered integrated system with high visibility and limited funding and expires at the end of the Fiscal Year? Whether driven by budget cycles, safety, or by management decree, many such projects begin with generic scopes and funding allocatedmore » based on a rapid management 'guestimate.' Then a Project Manager (PM) is assigned a project with a predefined and potentially limited scope, compressed schedule, and potentially insufficient funding. The PM is tasked to rapidly and cost effectively coordinate a requirements-based design, implementation, test, and turnover of a fully operational system to the customer, all while the customer is operating and maintaining an existing security system. Many project management manuals call this an impossible project that should not be attempted. However, security is serious business and the reality is that rapid deployment of proven systems via an 'Extreme Project' is sometimes necessary. Extreme Projects can be wildly successful but require a dedicated team of security professionals lead by an experienced project manager using a highly-tailored and agile project management process with management support at all levels, all combined with significant interface with the customer. This paper does not advocate such projects or condone eliminating the valuable analysis and project management techniques. Indeed, having worked on a well-planned project provides the basis for experienced team members to complete Extreme Projects. This paper does, however, provide insight into what it takes for projects to be successfully implemented and accepted when completed under extreme conditions.« less

Global Losses and Declining Vulnerability to Tropical Cyclones

NASA Astrophysics Data System (ADS)

Narita, D.; Hsiang, S. M.

2011-12-01

Approach An extreme environmental event may generate different losses for different societies. If the physical exposure to an event is held fixed, then the magnitude of a society's loss defines its vulnerability to that event. Competing hypotheses suggest that social and economic developments could make vulnerability rise or fall over time, but previous studies have been unable to reject either hypothesis because they lacked accurate data on societies' physical exposure to extreme events. We address this problem for a specific type of event by reconstructing the exposure of 233 countries to every tropical cyclone (TC) on the planet between 1950 and 2008 in making use of the Limited Information Cyclone Reconstruction and Integration for Climate and Economics (LICRICE) model [Hsiang, 2010]. By filling a critical data gap, this reconstruction enables us to compare how revenue losses, damages, and deaths from physically similar events change over time. Our approach contrasts with a large literature, which relies almost exclusively on self-reporting data of TC damages compiled by the Emergency Events Database (EM-DAT)[OFDA/CRED, 2009]. Results On a global scale, we find that populations rapidly mitigate certain TC risks, reducing their reported damages from a TC of low intensity by a remarkable 9.4% yr-1 and death rates by 5.1% yr-1 (Figure 1). However, these rapid reductions in vulnerability are not evident for the highest intensity TCs and lost agricultural revenues, which are more difficult to observe than deaths or damages, exhibit non-declining vulnerability for events of all intensities. Because the vulnerability of agriculture has remained high while vulnerability to damages has declined rapidly, our results indicate that lost agricultural revenues have dominated TC losses ever since ˜1990. References Hsiang, S. M. (2010). Temperatures and cyclones strongly associated with economic production in the Caribbean and Central America. Proceedings of the National Academy of Sciences, 107(35):15367-15372. OFDA/CRED (2009). The International Disaster Database.

Bubble nasal CPAP, early surfactant treatment, and rapid extubation are associated with decreased incidence of bronchopulmonary dysplasia in very-low-birth-weight newborns: efficacy and safety considerations.

PubMed

Friedman, Charles A; Menchaca, Robert C; Baker, Mary C; Rivas, Clarissa K; Laberge, Raymond N; Rios, Enrique H; Haider, Syed H; Romero, Edgar J; Eason, Elizabeth B; Fraley, J Kennard; Woldesenbet, Mesfin

2013-07-01

Current literature has been inconsistent in demonstrating that minimizing the duration of mechanical ventilation in very-low-birth-weight (VLBW) newborns reduces lung damage. To determine if introduction of bubble nasal CPAP (bnCPAP), early surfactant treatment, and rapid extubation (combined bnCPAP strategy) in our community-based neonatal ICU reduced bronchopulmonary dysplasia (BPD). This was a 7-year retrospective,single-institution review of respiratory outcomes in 633 VLBW babies before and after introduction of the combined bnCPAP strategy. Coincident changes in newborn care were taken into account with a logistic regression model. The average percentage of VLBW newborns with BPD decreased to 25.8% from 35.4% (P = .02), reaching a minimum in the last post-bnCPAP year of22.1% (P = .02). When other coincident changes in newborn care during the study years were taken into account, VLBW babies in the post-bnCPAP years had a 43% lower chance of developing BPD(P = .003, odds ratio 0.43, 95% CI 0.25– 0.75). Decreases occurred in mechanical ventilation and the percentage of infants discharged on diuretics and on supplemental oxygen. Among the subset of extremely-low-birth-weight newborns, improved respiratory outcomes in the post-bnCPAP years,as compared to outcomes in the pre-bnCPAP years, included an increase in the percentage alive and off mechanical ventilation at 1 week postnatal age (P < .001), a more rapid extubation rate(P < .03), a decrease in the median days on mechanical ventilation (P = .002), and a decrease in the percentage with BPD plus died (P = .01). Post-bnCPAP extremely-low-birth-weight babies had a statistically significant decrease in retinopathy of prematurity, an increase in low-grade intraventricular hemorrhage, and a decrease in ductal ligations. A combined BnCPAP strategy may contribute to a reduction of BPD, after adjusting for concurrent treatments.

Differential Effects of Temperature Extremes on Hospital Admission Rates for Respiratory Disease between Indigenous and Non-Indigenous Australians in the Northern Territory

PubMed Central

Green, Donna; Bambrick, Hilary; Tait, Peter; Goldie, James; Schultz, Rosalie; Webb, Leanne; Alexander, Lisa; Pitman, Andrew

2015-01-01

The health gap between Indigenous and non-Indigenous Australians may be exacerbated by climate change if temperature extremes have disproportionate adverse effects on Indigenous people. To explore this issue, we analysed the effect of temperature extremes on hospital admissions for respiratory diseases, stratified by age, Indigenous status and sex, for people living in two different climates zones in the Northern Territory during the period 1993–2011. We examined admissions for both acute and chronic respiratory diagnoses, controlling for day of the week and seasonality variables. Our analysis showed that: (1) overall, Indigenous hospital admission rates far exceeded non-Indigenous admission rates for acute and chronic diagnoses, and Top End climate zone admission rates exceeded Central Australia climate zone admission rates; (2) extreme cold and hot temperatures were associated with inconsistent changes in admission rates for acute respiratory disease in Indigenous and non-Indigenous children and older adults; and (3) no response to cold or hot temperature extremes was found for chronic respiratory diagnoses. These findings support our two hypotheses, that extreme hot and cold temperatures have a different effect on hospitalisations for respiratory disease between Indigenous and non-Indigenous people, and that these health risks vary between the different climate zones. We did not, however, find that there were differing responses to temperature extremes in the two populations, suggesting that any increased vulnerability to climate change in the Indigenous population of the Northern Territory arises from an increased underlying risk to respiratory disease and an already greater existing health burden. PMID:26633456

RS3PE presenting in a unilateral pattern: case report and review of the literature.

PubMed

Keenan, Robert T; Hamalian, Gareen M; Pillinger, Michael H

2009-06-01

To review the clinical features and pathophysiologic implications of remitting seronegative symmetrical synovitis with pitting edema (RS(3)PE) presenting in a unilateral manner. We identified and characterized an index case of RS(3)PE presenting in a unilateral pattern. We subsequently performed a systematic literature search to identify other reports of patients with unilateral RS(3)PE. The index case was a 76-year-old male with a prior history of right hemiparesis owing to a cerebrovascular accident 25 years prior, who developed a classic picture of RS(3)PE involving hand (metacarpophalageal and wrist joint) arthritis and dorsal pitting edema, accompanied by an elevated erythrocyte sedimentation rate, but only in the nonhemiparetic hand. The condition responded rapidly to low-dose prednisone. Our literature search identified 5 other cases of unilateral RS(3)PE, including 2 presented only in the Italian or German literature. Of the 5 cases, 2 were in patients with preexisting neurologic disease, in which the neurologically affected side was spared. One additional case initially presented as unilateral disease but rapidly progressed to bilaterality. Two cases presented in a fully unilateral manner despite no reported neurologic abnormalities on the unaffected sides. While RS(3)PE is almost always a symmetric disease of the upper extremities, it may rarely present in a unilateral fashion. The apparent ability of neuropathic changes to protect against the expression of RS(3)PE in an extremity suggests a role for neural and possibly other local factors in the genesis/modulation of the onset or maintenance of RS(3)PE.

Rapid separation of very low concentrations of bacteria from blood.

PubMed

Buchanan, Clara M; Wood, Ryan L; Hoj, Taalin R; Alizadeh, Mahsa; Bledsoe, Colin G; Wood, Madison E; McClellan, Daniel S; Blanco, Rae; Hickey, Caroline L; Ravsten, Tanner V; Husseini, Ghaleb A; Robison, Richard A; Pitt, William G

2017-08-01

A rapid and accurate diagnosis of the species and antibiotic resistance of bacteria in septic blood is vital to increase survival rates of patients with bloodstream infections, particularly those with carbapenem-resistant enterobacteriaceae (CRE) infections. The extremely low levels in blood (1 to 100CFU/ml) make rapid diagnosis difficult. In this study, very low concentrations of bacteria (6 to 200CFU/ml) were separated from 7ml of whole blood using rapid sedimentation in a spinning hollow disk that separated plasma from red and white cells, leaving most of the bacteria suspended in the plasma. Following less than a minute of spinning, the disk was slowed, the plasma was recovered, and the bacteria were isolated by vacuum filtration. The filters were grown on nutrient plates to determine the number of bacteria recovered from the blood. Experiments were done without red blood cell (RBC) lysis and with RBC lysis in the recovered plasma. While there was scatter in the data from blood with low bacterial concentrations, the mean average recovery was 69%. The gender of the blood donor made no statistical difference in bacterial recovery. These results show that this rapid technique recovers a significant amount of bacteria from blood containing clinically relevant low levels of bacteria, producing the bacteria in minutes. These bacteria could subsequently be identified by molecular techniques to quickly identify the infectious organism and its resistance profile, thus greatly reducing the time needed to correctly diagnose and treat a blood infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Increasing Lower Extremity Injury Rates Across the 2009-2010 to 2014-2015 Seasons of National Collegiate Athletic Association Football: An Unintended Consequence of the "Targeting" Rule Used to Prevent Concussions?

PubMed

Westermann, Robert W; Kerr, Zachary Y; Wehr, Peter; Amendola, Annuziato

2016-12-01

Sports-related concussions (SRCs) have gained increased societal interest in the past decade. The National Collegiate Athletic Association (NCAA) has implemented legislation and rule changes to decrease the incidence and risk of head injury impacts. The "targeting" rule forbids initiating contact with the crown of a helmet and targeting defenseless players in the head and neck area; however, there are concerns that this rule change has unintentionally led to an increased incidence of lower extremity injuries. The purpose of this study was to evaluate the change in lower extremity injury rates in NCAA football during the 2009-2010 to 2014-2015 seasons. We hypothesized that the lower extremity injury rate has increased across the time period. Descriptive epidemiology study. Sixty-eight NCAA football programs provided 153 team-seasons of data to the NCAA Injury Surveillance Program. Lower extremity injuries (ie, hip/groin, upper leg/thigh, knee, lower leg/Achilles, foot/toes) and SRCs sustained during NCAA football games were examined. We calculated injury rates per 1000 athlete-exposures (AEs) for lower extremity injuries and SRCs. Rate ratios (RRs) compared injury rates between the 2009-2010 to 2011-2012 and 2012-2013 to 2014-2015 seasons. Overall, 2400 lower extremity injuries were reported during the 2009-2010 to 2014-2015 seasons; most were to the knee (33.6%) and ankle (28.5%) and caused by player contact (59.2%). The lower extremity injury rate increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (23.55 vs 20.45/1000 AEs, respectively; RR, 1.15; 95% CI, 1.06-1.25). This finding was retained when restricted to injuries due to player contact (RR, 1.19; 95% CI, 1.07-1.32) but not for injuries due to noncontact/overuse (RR, 0.96; 95% CI, 0.80-1.14). When examining player contact injury rates by anatomic site, only ankle injuries had an increase (RR, 1.36; 95% CI, 1.13-1.64). The SRC rate also increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (3.52 vs 2.63/1000 AEs, respectively; RR, 1.34; 95% CI, 1.08-1.66). The lower extremity injury rate has increased in NCAA football athletes. Similarly, SRC rates have increased, although this may be caused by concurrent policies related to better education, identification, and management. Targeting rule changes may be contributing to increased rates of player contact-related ankle injuries. Alongside continued surveillance research to examine longitudinal time trends, more in-depth individual-level examinations of how targeting rule changes influence coaching and player behaviors are warranted. © 2016 The Author(s).

Real-time observation of DNA recognition and rejection by the RNA-guided endonuclease Cas9.

PubMed

Singh, Digvijay; Sternberg, Samuel H; Fei, Jingyi; Doudna, Jennifer A; Ha, Taekjip

2016-09-14

Binding specificity of Cas9-guide RNA complexes to DNA is important for genome-engineering applications; however, how mismatches influence target recognition/rejection kinetics is not well understood. Here we used single-molecule FRET to probe real-time interactions between Cas9-RNA and DNA targets. The bimolecular association rate is only weakly dependent on sequence; however, the dissociation rate greatly increases from <0.006 s(-1) to >2 s(-1) upon introduction of mismatches proximal to protospacer-adjacent motif (PAM), demonstrating that mismatches encountered early during heteroduplex formation induce rapid rejection of off-target DNA. In contrast, PAM-distal mismatches up to 11 base pairs in length, which prevent DNA cleavage, still allow formation of a stable complex (dissociation rate <0.006 s(-1)), suggesting that extremely slow rejection could sequester Cas9-RNA, increasing the Cas9 expression level necessary for genome-editing, thereby aggravating off-target effects. We also observed at least two different bound FRET states that may represent distinct steps in target search and proofreading.

Chasing a complete understanding of a rapid moving rock slide: the La Saxe landslide

NASA Astrophysics Data System (ADS)

Crosta, G. B.; Cancelli, P.; Tamburini, A.; Alberto, W.; Broccolato, M.; Castellanza, R.; Frattini, P.; Agliardi, F.; Rivolta, C.; Leva, D.

2012-04-01

Large deep seated slope deformations affect entire valley flanks and are characterized by slow to extremely slow present day displacement rates. Because of their extreme size, they are frequently characterized at their interior by secondary instabilities which can be classified as rockslides, that can originate large rock avalanches or can move at much faster rates with respect to the main mass. As a consequence local instabilities and reactivation of sectors of deep seated deformations should be carefully monitored and studied especially because they can affect strongly deformed and weakened rock masses. Because of these natural conditions and their preferential location in coincidence of slope steepening, these rockslides can undergo rapid evolution and activation putting the upmost urgency for monitoring, hazard and risk assessment. We present the case study of the La Saxe rockslide (Courmayeur, Aosta valley, Italy), located within a deep seated deformation affecting most of the 10 km long left hand flank of the Ferret valley (between 1340 m and 2300 m a.s.l.) and which underwent a major phase of acceleration in the last decade. The rockslide affects the extreme south western tip of the deep seated deformation at the outlet of Ferret valley, with an estimated volume of about 8 x 106 m3 of clay schists and thinly bedded black carbonates, intensely folded and faulted. An intense investigation activity has been performed in the last 2 years to reach a more complete understanding of the phenomenon. Boreholes have been drilled, logged, and instrumented to constrain the landslide volume, the rate of displacement at depth, and the water pressure. Displacement monitoring has been undertaken at successive steps by setting up sequentially: a distance measurement network (6 optical targets), a GPS network for periodic measurements (12 stations), a ground-based interferometer (GB-InSAR, LisaLab, by Ellegi, with 10 min acquisition intervals), a geodetic network based on a total station and 25 optical targets measured at 2 h intervals, a GPS network (7 stations) for quasi-real time measurements, four differential multiparametric borehole systems (DMS columns up to 100 m long). A geotechnical network has been also implemented including open pipe piezometers, borehole wire extensometers and inclinometric casings. This enormous monitoring effort is motivated by the extreme risk associated to this phenomenon, which is hanging over a famous touristic resort, a world famous cable way, the Mont Blanc highway, and in close proximity to the Mont Blanc tunnel. Rockslide characterization, failure surface definition, and groundwater flow investigations allowed for a series of slope stability analyses to be completed, together with modelling of the expected invasion area. Relationships with snowmelt have been ascertained and an early warning system based on real time measurements redundancy and all weather capabilities has been set up. LisaLab GB-InSAR equipment continuously provide spatially distributed displacement data which have been analysed to identify different failure scenarios and sensitivity of the landslide to triggering and controlling factors. Geodetic measurements are integrated with GB-InSAR data for verification and in depth 3D displacement reconstructions.

Rapid formation and evolution of an extreme haze episode in Northern China during winter 2015

PubMed Central

Sun, Yele; Chen, Chen; Zhang, Yingjie; Xu, Weiqi; Zhou, Libo; Cheng, Xueling; Zheng, Haitao; Ji, Dongsheng; Li, Jie; Tang, Xiao; Fu, Pingqing; Wang, Zifa

2016-01-01

We investigate the rapid formation and evolutionary mechanisms of an extremely severe and persistent haze episode that occurred in northern China during winter 2015 using comprehensive ground and vertical measurements, along with receptor and dispersion model analysis. Our results indicate that the life cycle of a severe winter haze episode typically consists of four stages: (1) rapid formation initiated by sudden changes in meteorological parameters and synchronous increases in most aerosol species, (2) persistent evolution with relatively constant variations in secondary inorganic aerosols and secondary organic aerosols, (3) further evolution associated with fog processing and significantly enhanced sulfate levels, and (4) clearing due to dry, cold north-northwesterly winds. Aerosol composition showed substantial changes during the formation and evolution of the haze episode but was generally dominated by regional secondary aerosols (53–67%). Our results demonstrate the important role of regional transport, largely from the southwest but also from the east, and of coal combustion emissions for winter haze formation in Beijing. Also, we observed an important downward mixing pathway during the severe haze in 2015 that can lead to rapid increases in certain aerosol species. PMID:27243909

Halobacterium saccharovorum sp. nov., a carbohydrate-metabolizing, extremely halophilic bacterium

NASA Technical Reports Server (NTRS)

Tomlinson, G. A.; Hochstein, L. I.

1976-01-01

The previously described extremely halophilic bacterium, strain M6, metabolizes a variety of carbohydrates with the production of acid. In addition, the organism produces nitrite (but no gas) from nitrate, is motile, and grows most rapidly at about 50 C. These characteristics distinguish it from all previously described halophilic bacteria in the genus Halobacterium. It is suggested that it be designated as a new species, Halobacterium saccharovorum.

Weak linkage between the heaviest rainfall and tallest storms.

PubMed

Hamada, Atsushi; Takayabu, Yukari N; Liu, Chuntao; Zipser, Edward J

2015-02-24

Conventionally, the heaviest rainfall has been linked to the tallest, most intense convective storms. However, the global picture of the linkage between extreme rainfall and convection remains unclear. Here we analyse an 11-year record of spaceborne precipitation radar observations and establish that a relatively small fraction of extreme convective events produces extreme rainfall rates in any region of the tropics and subtropics. Robust differences between extreme rainfall and convective events are found in the rainfall characteristics and environmental conditions, irrespective of region; most extreme rainfall events are characterized by less intense convection with intense radar echoes not extending to extremely high altitudes. Rainfall characteristics and environmental conditions both indicate the importance of warm-rain processes in producing extreme rainfall rates. Our results demonstrate that, even in regions where severe convective storms are representative extreme weather events, the heaviest rainfall events are mostly associated with less intense convection.

Some implications of changing patterns of mineral consumption

USGS Publications Warehouse

Menzie, W. David; DeYoung,, John H.; Steblez, Walter G.

2003-01-01

DeYoung and Menzie (1999) examined the relations among population, Gross Domestic Product, and mineral consumption (aluminum, cement, copper, and salt) for Japan, Korea, and the United States between 1965 and 1995. They noted the extremely rapid growth of consumption in Korea between 1975 and 1995. Concomitantly, Korea's population growth rate declined. This paper extends that earlier work by examining patterns of consumption of these same commodities in the twenty most populous countries for the period 1970 through 1995. Developed countries, such as France, Germany, Japan, the United Kingdom, and the United States, show patterns of consumption that are stable (cement, copper, and salt) or grow slowly (aluminum). Some developing countries, including China, Thailand, and Turkey, show more rapid growth of consumption, especially of cement, copper, and aluminum. These changing patterns of mineral consumption in developing countries have important implications -- if they continue, there could be major increases in world mineral consumption and major increases in environmental residuals from mineral production and use. If China reaches the level of consumption of copper of developed countries, world consumption could reach levels more than twice that of 1995 (10.5 million tons).

Biomechanical consequences of rapid evolution in the polar bear lineage.

PubMed

Slater, Graham J; Figueirido, Borja; Louis, Leeann; Yang, Paul; Van Valkenburgh, Blaire

2010-11-05

The polar bear is the only living ursid with a fully carnivorous diet. Despite a number of well-documented craniodental adaptations for a diet of seal flesh and blubber, molecular and paleontological data indicate that this morphologically distinct species evolved less than a million years ago from the omnivorous brown bear. To better understand the evolution of this dietary specialization, we used phylogenetic tests to estimate the rate of morphological specialization in polar bears. We then used finite element analysis (FEA) to compare the limits of feeding performance in the polar bear skull to that of the phylogenetically and geographically close brown bear. Results indicate that extremely rapid evolution of semi-aquatic adaptations and dietary specialization in the polar bear lineage produced a cranial morphology that is weaker than that of brown bears and less suited to processing tough omnivorous or herbivorous diets. Our results suggest that continuation of current climate trends could affect polar bears by not only eliminating their primary food source, but also through competition with northward advancing, generalized brown populations for resources that they are ill-equipped to utilize.

Evolution of newborn rapidly rotating magnetars: Effects of R-mode and fall-back accretion

NASA Astrophysics Data System (ADS)

Wang, Jie-Shuang; Dai, Zi-Gao

2017-06-01

In this paper we investigate effects of the r-mode instability on a newborn rapidly-rotating magnetar with fall-back accretion. Such a magnetar could usually occur in core-collapse supernovae and gamma-ray bursts. We find that the magnetar's spin and r-mode evolution are influenced by accretion. If the magnetar is sufficiently spun up to a few milliseconds, gravitational radiation leads to the growth of the r-mode amplitude significantly. The maximum r-mode amplitude reaches an order of 0.001 when the damping due to the growth of a toroidal magnetic field balances the growth of the r-mode amplitude. If such a sufficiently spun-up magnetar was located at a distance less than 1 Mpc, then gravitational waves would be detectable by the Einstein Telescope but would have an extremely low event rate. However, if the spin-up is insufficient, the growth of the r-mode amplitude is mainly due to the accretion torque. In this case, the maximum r-mode amplitude is of the order of 10-6-10-5.

Optimizing high performance computing workflow for protein functional annotation.

PubMed

Stanberry, Larissa; Rekepalli, Bhanu; Liu, Yuan; Giblock, Paul; Higdon, Roger; Montague, Elizabeth; Broomall, William; Kolker, Natali; Kolker, Eugene

2014-09-10

Functional annotation of newly sequenced genomes is one of the major challenges in modern biology. With modern sequencing technologies, the protein sequence universe is rapidly expanding. Newly sequenced bacterial genomes alone contain over 7.5 million proteins. The rate of data generation has far surpassed that of protein annotation. The volume of protein data makes manual curation infeasible, whereas a high compute cost limits the utility of existing automated approaches. In this work, we present an improved and optmized automated workflow to enable large-scale protein annotation. The workflow uses high performance computing architectures and a low complexity classification algorithm to assign proteins into existing clusters of orthologous groups of proteins. On the basis of the Position-Specific Iterative Basic Local Alignment Search Tool the algorithm ensures at least 80% specificity and sensitivity of the resulting classifications. The workflow utilizes highly scalable parallel applications for classification and sequence alignment. Using Extreme Science and Engineering Discovery Environment supercomputers, the workflow processed 1,200,000 newly sequenced bacterial proteins. With the rapid expansion of the protein sequence universe, the proposed workflow will enable scientists to annotate big genome data.

Decrease in hydrogen sulfide content during the final stage of beer fermentation due to involvement of yeast and not carbon dioxide gas purging.

PubMed

Oka, Kaneo; Hayashi, Teruhiko; Matsumoto, Nobuya; Yanase, Hideshi

2008-09-01

We observed a rapid decrease in hydrogen sulfide content in the final stage of beer fermentation that was attributed to yeast and not to the purging of carbon dioxide (CO(2)) gas. The well known immature off-flavor in beer due to hydrogen sulfide (H(2)S) behavior during beer fermentation was closely investigated. The H(2)S decrease occurred during the final stage of fermentation when the CO(2)-evolution rate was extremely small and there was a decrease in the availability of fermentable sugars, suggesting that the exhaustion of fermentable sugars triggered the decrease in H(2)S. An H(2)S-balance analysis suggested that the H(2)S decrease might have been caused due to sulfide uptake by yeast. Further investigation showed that the time necessary for H(2)S to decrease below the sensory threshold was related to the number of suspended yeast cells. This supported the hypothesis that yeast cells contributed to the rapid decrease in H(2)S during the final stage of beer fermentation.

Rapid antibiotic-resistance predictions from genome sequence data for Staphylococcus aureus and Mycobacterium tuberculosis

PubMed Central

Bradley, Phelim; Gordon, N. Claire; Walker, Timothy M.; Dunn, Laura; Heys, Simon; Huang, Bill; Earle, Sarah; Pankhurst, Louise J.; Anson, Luke; de Cesare, Mariateresa; Piazza, Paolo; Votintseva, Antonina A.; Golubchik, Tanya; Wilson, Daniel J.; Wyllie, David H.; Diel, Roland; Niemann, Stefan; Feuerriegel, Silke; Kohl, Thomas A.; Ismail, Nazir; Omar, Shaheed V.; Smith, E. Grace; Buck, David; McVean, Gil; Walker, A. Sarah; Peto, Tim E. A.; Crook, Derrick W.; Iqbal, Zamin

2015-01-01

The rise of antibiotic-resistant bacteria has led to an urgent need for rapid detection of drug resistance in clinical samples, and improvements in global surveillance. Here we show how de Bruijn graph representation of bacterial diversity can be used to identify species and resistance profiles of clinical isolates. We implement this method for Staphylococcus aureus and Mycobacterium tuberculosis in a software package (‘Mykrobe predictor') that takes raw sequence data as input, and generates a clinician-friendly report within 3 minutes on a laptop. For S. aureus, the error rates of our method are comparable to gold-standard phenotypic methods, with sensitivity/specificity of 99.1%/99.6% across 12 antibiotics (using an independent validation set, n=470). For M. tuberculosis, our method predicts resistance with sensitivity/specificity of 82.6%/98.5% (independent validation set, n=1,609); sensitivity is lower here, probably because of limited understanding of the underlying genetic mechanisms. We give evidence that minor alleles improve detection of extremely drug-resistant strains, and demonstrate feasibility of the use of emerging single-molecule nanopore sequencing techniques for these purposes. PMID:26686880

Optimizing high performance computing workflow for protein functional annotation

PubMed Central

Stanberry, Larissa; Rekepalli, Bhanu; Liu, Yuan; Giblock, Paul; Higdon, Roger; Montague, Elizabeth; Broomall, William; Kolker, Natali; Kolker, Eugene

2014-01-01

Functional annotation of newly sequenced genomes is one of the major challenges in modern biology. With modern sequencing technologies, the protein sequence universe is rapidly expanding. Newly sequenced bacterial genomes alone contain over 7.5 million proteins. The rate of data generation has far surpassed that of protein annotation. The volume of protein data makes manual curation infeasible, whereas a high compute cost limits the utility of existing automated approaches. In this work, we present an improved and optmized automated workflow to enable large-scale protein annotation. The workflow uses high performance computing architectures and a low complexity classification algorithm to assign proteins into existing clusters of orthologous groups of proteins. On the basis of the Position-Specific Iterative Basic Local Alignment Search Tool the algorithm ensures at least 80% specificity and sensitivity of the resulting classifications. The workflow utilizes highly scalable parallel applications for classification and sequence alignment. Using Extreme Science and Engineering Discovery Environment supercomputers, the workflow processed 1,200,000 newly sequenced bacterial proteins. With the rapid expansion of the protein sequence universe, the proposed workflow will enable scientists to annotate big genome data. PMID:25313296

Managing urban water systems with significant adaptation deficits - a unified framework for secondary cities

NASA Astrophysics Data System (ADS)

Pathirana, A.; Radhakrishnan, M.; Zevenbergen, C.; Quan, N. H.

2016-12-01

The need to address the shortcomings of urban systems - adaptation deficit - and shortcomings in response to climate change - `adaptation gap' - are both major challenges in maintaining the livability and sustainability of cities. However, the adaptation actions defined in terms of type I (addressing adaptation deficits) and type II (addressing adaptation gaps), often compete and conflict each other in the secondary cities of the global south. Extending the concept of the environmental Kuznets curve, this paper argues that a unified framework that calls for synergistic action on type I and type II adaptation is essential in order for these cities to maintain their livability, sustainability and resilience facing extreme rates of urbanization and rapid onset of climate change. The proposed framework has been demonstrated in Can Tho, Vietnam, where there are significant adaptation deficits due to rapid urbanisation and adaptation gaps due to climate change and socio-economic changes. The analysis in Can Tho reveals the lack of integration between type I and type II measures that could be overcome by closer integration between various stakeholders in terms of planning, prioritising and implementing the adaptation measures.

Physiological and Transcriptional Responses of Different Industrial Microbes at Near-Zero Specific Growth Rates.

PubMed

Ercan, Onur; Bisschops, Markus M M; Overkamp, Wout; Jørgensen, Thomas R; Ram, Arthur F; Smid, Eddy J; Pronk, Jack T; Kuipers, Oscar P; Daran-Lapujade, Pascale; Kleerebezem, Michiel

2015-09-01

The current knowledge of the physiology and gene expression of industrially relevant microorganisms is largely based on laboratory studies under conditions of rapid growth and high metabolic activity. However, in natural ecosystems and industrial processes, microbes frequently encounter severe calorie restriction. As a consequence, microbial growth rates in such settings can be extremely slow and even approach zero. Furthermore, uncoupling microbial growth from product formation, while cellular integrity and activity are maintained, offers perspectives that are economically highly interesting. Retentostat cultures have been employed to investigate microbial physiology at (near-)zero growth rates. This minireview compares information from recent physiological and gene expression studies on retentostat cultures of the industrially relevant microorganisms Lactobacillus plantarum, Lactococcus lactis, Bacillus subtilis, Saccharomyces cerevisiae, and Aspergillus niger. Shared responses of these organisms to (near-)zero growth rates include increased stress tolerance and a downregulation of genes involved in protein synthesis. Other adaptations, such as changes in morphology and (secondary) metabolite production, were species specific. This comparison underlines the industrial and scientific significance of further research on microbial (near-)zero growth physiology. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Attributing Changing Rates of Temperature Record Breaking to Anthropogenic Influences

NASA Astrophysics Data System (ADS)

King, Andrew D.

2017-11-01

Record-breaking temperatures attract attention from the media, so understanding how and why the rate of record breaking is changing may be useful in communicating the effects of climate change. A simple methodology designed for estimating the anthropogenic influence on rates of record breaking in a given time series is proposed here. The frequency of hot and cold record-breaking temperature occurrences is shown to be changing due to the anthropogenic influence on the climate. Using ensembles of model simulations with and without human-induced forcings, it is demonstrated that the effect of climate change on global record-breaking temperatures can be detected as far back as the 1930s. On local scales, a climate change signal is detected more recently at most locations. The anthropogenic influence on the increased occurrence of hot record-breaking temperatures is clearer than it is for the decreased occurrence of cold records. The approach proposed here could be applied in rapid attribution studies of record extremes to quantify the influence of climate change on the rate of record breaking in addition to the climate anomaly being studied. This application is demonstrated for the global temperature record of 2016 and the Central England temperature record in 2014.

Li+ /Mg2+ Hybrid-Ion Batteries with Long Cycle Life and High Rate Capability Employing MoS2 Nano Flowers as the Cathode Material.

PubMed

Ju, Yanming; Meng, Yuan; Wei, Yingjin; Bian, Xiaofei; Pang, Qiang; Gao, Yu; Du, Fei; Liu, Bingbing; Chen, Gang

2016-12-12

The demand for large-scale and safe energy storage is increasing rapidly due to the strong push for smartphones and electric vehicles. As a result, Li + /Mg 2+ hybrid-ion batteries (LMIBs) combining a dendrite-free deposition of Mg anode and Li + intercalation cathode have attracted considerable attention. Here, a LMIB with hydrothermal-prepared MoS 2 nano flowers as cathode material was prepared. The battery showed remarkable electrochemical properties with a large discharge capacity (243 mAh g -1 at the 0.1 C rate), excellent rate capability (108 mAh g -1 at the 5 C rate), and long cycle life (87.2 % capacity retention after 2300 cycles). Electrochemical analysis showed that the reactions occurring in the battery cell involved Mg stripping/plating at the anode side and Li + intercalation at the cathode side with a small contribution from Mg 2+ adsorption. The excellent electrochemical performance and extremely safe cell system show promise for its use in practical applications. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inhibiting polysulfides diffusion of lithium-sulfur batteries using an acetylene black-CoS2 modified separator: Mechanism research and performance improvement

NASA Astrophysics Data System (ADS)

Zeng, Pan; Huang, Liwu; Zhang, Xinling; Han, Yamiao; Chen, Yungui

2018-01-01

Lithium-sulfur (Li-S) batteries are considered as one of the most promising chemistries in secondary energy storage field owing to their high energy density. However, the poor electrochemical performance mainly associated with the polysulfides shuttle has greatly hampered their practical application. Herein, a simple acetylene black (AB)-CoS2 coated separator is first designed to suppress the migration of polysulfides. The AB-CoS2 modified separator can not only efficiently capture the polysulfides by forming strong chemical bonding but also guarantee the rapid lithium ions diffusion. Moreover, the AB-CoS2 coating could serve as an upper current collector to accelerate electron transport for reinforcing the utilization of sulfur and ensuring the reactivation of the trapped active material. Consequently, the Li-S cell using AB-CoS2 modified separator shows a long-term cycling stability with an extremely low decay rate (0.09% per cycle) up to 450 cycles at a high rate of 2 C (3350 mA g-1). It also exhibits excellent rate capabilities, which maintains a capacity of 475 mAh g-1 even at 4.0 C rate.

Chandra Data Reveal Rapidly Whirling Black Holes

NASA Astrophysics Data System (ADS)

2008-01-01

A new study using results from NASA's Chandra X-ray Observatory provides one of the best pieces of evidence yet that many supermassive black holes are spinning extremely rapidly. The whirling of these giant black holes drives powerful jets that pump huge amounts of energy into their environment and affects galaxy growth. A team of scientists compared leading theories of jets produced by rotating supermassive black holes with Chandra data. A sampling of nine giant galaxies that exhibit large disturbances in their gaseous atmospheres showed that the central black holes in these galaxies must be spinning at near their maximum rates. People Who Read This Also Read... NASA’s Swift Satellite Catches First Supernova in The Act of Exploding Black Holes Have Simple Feeding Habits Jet Power and Black Hole Assortment Revealed in New Chandra Image Erratic Black Hole Regulates Itself "We think these monster black holes are spinning close to the limit set by Einstein's theory of relativity, which means that they can drag material around them at close to the speed of light," said Rodrigo Nemmen, a visiting graduate student at Penn State University, and lead author of a paper on the new results presented at American Astronomical Society in Austin, Texas. The research reinforces other, less direct methods previously used which have indicated that some stellar and supermassive black holes are spinning rapidly. According to Einstein's theory, a rapidly spinning black hole makes space itself rotate. This effect, coupled with gas spiraling toward the black hole, can produce a rotating, tightly wound vertical tower of magnetic field that flings a large fraction of the inflowing gas away from the vicinity of the black hole in an energetic, high-speed jet. Computer simulations by other authors have suggested that black holes may acquire their rapid spins when galaxies merge, and through the accretion of gas from their surroundings. "Extremely fast spin might be very common for large black holes," said co-investigator Richard Bower of Durham University. "This might help us explain the source of these incredible jets that we see stretching for enormous distances across space." One significant connection consequence of powerful, black-hole jets in galaxies in the centers of galaxy clusters is that they can pump enormous amounts of energy into their environments, and heat the gas around them. This heating prevents the gas from cooling, and affects the rate at which new stars form, thereby limiting the size of the central galaxy. Understanding the details of this fundamental feedback loop between supermassive black holes and the formation of the most massive galaxies remains an important goal in astrophysics. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Forty years of economic growth and plummeting mortality: the mortality experience of the poorly educated in South Korea.

PubMed

Bahk, Jinwook; Lynch, John W; Khang, Young-Ho

2017-03-01

South Korea has experienced rapid economic development and a substantial increase in life expectancy in an extremely short period. Whether this rapid development has been able to adequately address inequalities in health in South Korea may have important policy implications. This paper explores long-term trends in inequalities in mortality related to education in South Korea between 1970 and 2010. We used secondary data on population size and deaths in 1970 and 1980 from a previously published study, and census and death certificate data from Statistics Korea from 1990, 1995, 2000, 2005 and 2010. Trends in age-standardised mortality rates for men and women aged 25-64 according to education, as well as the rate ratio (RR), rate difference (RD), relative index of inequality (RII) and slope index of inequality (SII), were examined over the period 1970-2010. Despite overall mortality declines of 70-80% in the past 4 decades, educational inequalities have increased or been stagnant. There was minimal decline in mortality since 1970 in South Koreans with only a primary or lower level of education. The RR and RD between tertiary education and primary or lower education increased over the study period, while the RII and the SII in both genders remained stable. The South Korean experience over the past 40 years suggests that plummeting mortality rates and huge advances in education at the population level do not translate into reduced educational inequalities in mortality. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Synthesis and anti-cancer efficacy of rapid hydrolysed water-soluble paclitaxel pro-drugs.

PubMed

Ryu, Beom-Young; Sohn, Jeong-Sun; Hess, Michael; Choi, Soo-Kyung; Choi, Jae-Kon; Jo, Byung-Wook

2008-01-01

A new series of poly(ethylene glycol)(PEG)-paclitaxel conjugates that increases water solubility of paclitaxel was synthesized. We developed well-designed self-immolating linkers between a drug and a water-soluble polymer moiety which gave an extremely rapid hydrolysis rate to convert a pro-drug into a parent drug without any reduction in drug efficacy. The self-immolating spacer groups were introduced between the solubilizing PEG and C7-OH of paclitaxel in order to control the rate of enzymatic hydrolysis. All these pro-drugs had a water-solubility of 400 mg/ml or more compared with a solubility of about 0.01 mg/ml. The rate of hydrolysis for the pro-drugs in rat plasma showed considerable variation of t((1/2)) ranging from 0.94 min to 42.7 min. To evaluate the anti-tumor efficacy of the pro-drug which had the fastest enzymatic hydrolysis rate, the growth inhibitory effect (IC(50)), the anti-tumor activity and the anti-metastatic potential of the pro-drug were examined. The pro-drug was potent to inhibit the growth of various cancer cell lines, such as human lung, ovarian, colon and melanoma cancer cells. On the development of melanoma lung colonies in C57B/6 mice following intravenous administration of metastatic murine B16/F10 melanoma cells, the pro-drug seems to be more efficacious than paclitaxel. The reduction of the number of melanoma lung colonies was 46.9% (dose: 5 mg/kg) with pure paclitaxel, and 24.5%, and 40.0% with the pro-drug in the dose of 0.71 mg paclitaxel equivalent/kg and 1.42 mg paclitaxel equivalent/kg, respectively.

Extreme Heat

MedlinePlus

... stomach, arms, or legs Actions: Go to a cooler location. Remove excess clothing. Take sips of cool ... above 103 degrees) taken orally; red, hot, and dry skin with no sweat; rapid, strong pulse; dizziness; ...

Sexual maturity in growing dinosaurs does not fit reptilian growth models

PubMed Central

Lee, Andrew H.; Werning, Sarah

2008-01-01

Recent histological studies suggest relatively rapid growth in dinosaurs. However, the timing of reproductive maturity (RM) in dinosaurs is poorly known because unambiguous indicators of RM are rare. One exception is medullary bone (MB), which is an ephemeral bony tissue that forms before ovulation in the marrow cavities of birds as a calcium source for eggshelling. Recently, MB also was described in a single specimen of the saurischian dinosaur Tyrannosaurus rex. Here, we report two other occurrences of MB: in another saurischian dinosaur, Allosaurus, and in the ornithischian dinosaur Tenontosaurus. We show by counting lines of arrested growth and performing growth curve reconstructions that Tenontosaurus, Allosaurus, and Tyrannosaurus were reproductively mature by 8, 10, and 18 years, respectively. RM in these dinosaurs coincided with a transition from growth acceleration to deceleration. It also far precedes predictions based on the growth rates of living reptiles scaled to similar size. Despite relatively rapid growth, dinosaurs were similar to reptiles in that RM developed before reaching asymptotic size. However, this reproductive strategy also occurs in medium- to large-sized mammals and correlates with a strategy of prolonged multiyear growth. RM in actively growing individuals suggests that these dinosaurs were born relatively precocial and experienced high adult mortality. The origin of the modern avian reproductive strategy in ornithuran birds likely coincided with their extreme elevations in growth rate and truncations to growth duration. PMID:18195356

Spatiotemporal measurement of translational and vibrational temperatures after pulsed corona discharge using laser spectroscopy

NASA Astrophysics Data System (ADS)

Ono, Ryo; Teramoto, Yoshiyuki; Nakagawa, Yusuke; Komuro, Atsushi; Oda, Tetsuji

2011-10-01

Translational and vibrational temperatures are measured in pulsed corona discharge using spatiotemporally resolved laser-induced fluorescence (LIF) and coherent anti-Stokes Raman scattering (CARS). The discharge occurs in a 13-mm point-to-plane gap with pulsed voltage of approximately 30 kV. Immediately after the discharge pulse, the vibrational temperatures of N2(v) and O2(v), Tv, are much higher than the translational temperature, Tt. Then, after the discharge pulse, Tv decreases with time, and the energy released from the vibrational relaxation increases Tt. This vibration-to-translation (V-T) energy transfer is observed; Tv and Tt change by hundreds to a thousand K after the discharge pulse with time constants of 1 us to 1 ms. It is shown that the V-T rate is remarkably increased when the ambient air is humidified. It is caused by extremely rapid V-T process of H2O-H2O system. In addition, V-T acceleration of O2(v) by O atoms due to rapid V-T rate of O2(v)-O system is also measured. The spatial profile of Tv shows that Tv decreases with increasing distance from the tip of needle electrode. It indicates that Tv, and the resulting Tt, are higher in the secondary streamer channel than in the primary streamer channel.

Sexual maturity in growing dinosaurs does not fit reptilian growth models.

PubMed

Lee, Andrew H; Werning, Sarah

2008-01-15

Recent histological studies suggest relatively rapid growth in dinosaurs. However, the timing of reproductive maturity (RM) in dinosaurs is poorly known because unambiguous indicators of RM are rare. One exception is medullary bone (MB), which is an ephemeral bony tissue that forms before ovulation in the marrow cavities of birds as a calcium source for eggshelling. Recently, MB also was described in a single specimen of the saurischian dinosaur Tyrannosaurus rex. Here, we report two other occurrences of MB: in another saurischian dinosaur, Allosaurus, and in the ornithischian dinosaur Tenontosaurus. We show by counting lines of arrested growth and performing growth curve reconstructions that Tenontosaurus, Allosaurus, and Tyrannosaurus were reproductively mature by 8, 10, and 18 years, respectively. RM in these dinosaurs coincided with a transition from growth acceleration to deceleration. It also far precedes predictions based on the growth rates of living reptiles scaled to similar size. Despite relatively rapid growth, dinosaurs were similar to reptiles in that RM developed before reaching asymptotic size. However, this reproductive strategy also occurs in medium- to large-sized mammals and correlates with a strategy of prolonged multiyear growth. RM in actively growing individuals suggests that these dinosaurs were born relatively precocial and experienced high adult mortality. The origin of the modern avian reproductive strategy in ornithuran birds likely coincided with their extreme elevations in growth rate and truncations to growth duration.

The POKEMON Speckle Survey of Nearby M-Dwarfs

NASA Astrophysics Data System (ADS)

van Belle, Gerard; von Braun, Kaspar; Horch, Elliott; Clark, Catherine; DSSI Speckle Team

2018-01-01

The POKEMON (Pervasive Overview of Kompanions of Every M-dwarf in Our Neighborhood) survey of nearby M-dwarfs intends to inspect, at diffraction-limited resolution, every low-mass star out to 15pc, along with selected additional objects to 25pc. The primary emphasis of the survey is detection of low-mass companions to these M-dwarfs for refinement of the low-mass star multiplicity rate. The resultant catalog of M-dwarf companions will also guide immediate refinement of transit planet detection results from surveys such as TESS. POKEMON is using Lowell Observatory's 4.3-m Discovery Channel Telescope (DCT) with the Differential Speckle Survey Instrument (DSSI) speckle camera, along with the NN-Explore Exoplanet Stellar Speckle Imager (NESSI) speckle imager on 3.5-m WIYN; the survey takes advantage of the extremely rapid observing cadence rates possible with WIYN and (especially) DCT. The current status and preliminary results from the first 20+ nights of observing will be presented. Gotta observe them all!

Pair-instability supernovae of fast rotating stars

NASA Astrophysics Data System (ADS)

Chen, Ke-Jung

2015-01-01

We present 2D simulations of pair-instability supernovae considering rapid rotation during their explosion phases. Recent studies of the Population III (Pop III) star formation suggested that these stars could be born with a mass scale about 100 M⊙ and with a strong rotation. Based on stellar evolution models, these massive Pop III stars might have died as highly energetic pair-instability supernovae. We perform 2D calculations to investigate the impact of rotation on pair-instability supernovae. Our results suggest that rotation leads to an aspherical explosion due to an anisotropic collapse. If the first stars have a 50% of keplerian rotational rate of the oxygen core before their pair-instability explosions, the overall 56Ni production can be significantly reduced by about two orders of magnitude. An extreme case of 100% keplerian rotational rate shows an interesting feature of fluid instabilities along the equatorial plane caused by non-synchronized and non-isotropic ignitions of explosions, so that the shocks run into the in-falling gas and generate the Richtmyer-Meshkov instability.

Sheathfolds in rheomorphic ignimbrites

USGS Publications Warehouse

Branney, M.J.; Barry, T.L.; Godchaux, Martha

2004-01-01

Structural reappraisal of several classic rheomorphic ignimbrites in Colorado, Idaho, the Canary Islands and Italy has, for the first time, revealed abundant oblique folds, curvilinear folds and sheathfolds which formed during emplacement. Like their equivalents in tectonic shear-zones, the sheathfold axes lie sub-parallel to a pervasive elongation lineation, and appear as eye structures on rock surfaces normal to the transport direction. With the recognition of sheathfolds, ignimbrites previously inferred to have undergone complex rheomorphic deformation histories are re-interpreted as recording a single, progressive deformation event. In some examples, the trends of sheathfolds and related lineations change with height through a single ignimbrite suggesting that rheomorphism did not affect the entire thickness of ignimbrite synchronously. Instead, we infer that in these ignimbrites a thin ductile shear-zone rose gradually through the aggrading agglutinating mass whilst the flow direction varied with time. This suggests that, in some cases, both welding and rheomorphism can be extremely rapid, with ductile strain rates significantly exceeding rates of ignimbrite aggradation. ?? Springer-Verlag 2004.

Microbial analysis of meatballs cooled with vacuum and conventional cooling.

PubMed

Ozturk, Hande Mutlu; Ozturk, Harun Kemal; Koçar, Gunnur

2017-08-01

Vacuum cooling is a rapid evaporative cooling technique and can be used for pre-cooling of leafy vegetables, mushroom, bakery, fishery, sauces, cooked food, meat and particulate foods. The aim of this study was to apply the vacuum cooling and the conventional cooling techniques for the cooling of the meatball and to show the vacuum pressure effect on the cooling time, the temperature decrease and microbial growth rate. The results of the vacuum cooling and the conventional cooling (cooling in the refrigerator) were compared with each other for different temperatures. The study shows that the conventional cooling was much slower than the vacuum cooling. Moreover, the microbial growth rate of the vacuum cooling was extremely low compared with the conventional cooling. Thus, the lowest microbial growth occurred at 0.7 kPa and the highest microbial growth was observed at 1.5 kPa for the vacuum cooling. The mass loss ratio for the conventional cooling and vacuum cooling was about 5 and 9% respectively.

Secure communications using nonlinear silicon photonic keys.

PubMed

Grubel, Brian C; Bosworth, Bryan T; Kossey, Michael R; Cooper, A Brinton; Foster, Mark A; Foster, Amy C

2018-02-19

We present a secure communication system constructed using pairs of nonlinear photonic physical unclonable functions (PUFs) that harness physical chaos in integrated silicon micro-cavities. Compared to a large, electronically stored one-time pad, our method provisions large amounts of information within the intrinsically complex nanostructure of the micro-cavities. By probing a micro-cavity with a rapid sequence of spectrally-encoded ultrafast optical pulses and measuring the lightwave responses, we experimentally demonstrate the ability to extract 2.4 Gb of key material from a single micro-cavity device. Subsequently, in a secure communication experiment with pairs of devices, we achieve bit error rates below 10 -5 at code rates of up to 0.1. The PUFs' responses are never transmitted over the channel or stored in digital memory, thus enhancing the security of the system. Additionally, the micro-cavity PUFs are extremely small, inexpensive, robust, and fully compatible with telecommunications infrastructure, components, and electronic fabrication. This approach can serve one-time pad or public key exchange applications where high security is required.

Injuries in an Extreme Conditioning Program.

PubMed

Aune, Kyle T; Powers, Joseph M

2016-10-19

Extreme conditioning programs (ECPs) are fitness training regimens relying on aerobic, plyometric, and resistance training exercises, often with high levels of intensity for a short duration of time. These programs have grown rapidly in popularity in recent years, but science describing the safety profile of these programs is lacking. The rate of injury in the extreme conditioning program is greater than the injury rate of weightlifting and the majority of injuries occur to the shoulder and back. Cross-sectional study. Level 4. This is a retrospective survey of injuries reported by athletes participating in an ECP. An injury survey was sent to 1100 members of Iron Tribe Fitness, a gym franchise with 5 locations across Birmingham, Alabama, that employs exercises consistent with an ECP in this study. An injury was defined as a physical condition resulting from ECP participation that caused the athlete to either seek medical treatment, take time off from exercising, or make modifications to his or her technique to continue. A total of 247 athletes (22%) completed the survey. The majority (57%) of athletes were male (n = 139), and 94% of athletes were white (n = 227). The mean age of athletes was 38.9 years (±8.9 years). Athletes reported participation in the ECP for, on average, 3.6 hours per week (± 1.2 hours). Eighty-five athletes (34%) reported that they had sustained an injury while participating in the ECP. A total of 132 injuries were recorded, yielding an estimated incidence of 2.71 per 1000 hours. The shoulder or upper arm was the most commonly injured body site, accounting for 38 injuries (15% of athletes). Athletes with a previous shoulder injury were 8.1 times as likely to injure their shoulder in the ECP compared with athletes with healthy shoulders. The trunk, back, head, or neck (n = 29, 12%) and the leg or knee (n = 29, 12%) were the second most commonly injured sites. The injury incidence rate among athletes with < 6 months of experience in the ECP was 2.5 times greater than that of more experienced athletes (≥6 months of experience). Of the 132 injuries, 23 (17%) required surgical intervention. Squat cleans, ring dips, overhead squats, and push presses were more likely to cause injury. Athletes reported that 35% of injuries were due to overexertion and 20% were due to improper technique. The estimated injury rate among athletes participating in this ECP was similar to the rate of injury in weightlifting and most other recreational activities. The shoulder or upper arm was the most commonly injured area, and previous shoulder injury predisposed to new shoulder injury. New athletes are at considerable risk of injury compared with more experienced athletes. Extreme conditioning programs are growing in popularity, and there is disagreement between science and anecdotal reports from athletes, coaches, and physicians about their relative safety. This study estimates the incidence of injury in extreme conditioning programs which appears to be similar to other weight-training programs. © 2016 The Author(s).

Injuries in an Extreme Conditioning Program

PubMed Central

Aune, Kyle T.; Powers, Joseph M.

2016-01-01

Background: Extreme conditioning programs (ECPs) are fitness training regimens relying on aerobic, plyometric, and resistance training exercises, often with high levels of intensity for a short duration of time. These programs have grown rapidly in popularity in recent years, but science describing the safety profile of these programs is lacking. Hypothesis: The rate of injury in the extreme conditioning program is greater than the injury rate of weightlifting and the majority of injuries occur to the shoulder and back. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: This is a retrospective survey of injuries reported by athletes participating in an ECP. An injury survey was sent to 1100 members of Iron Tribe Fitness, a gym franchise with 5 locations across Birmingham, Alabama, that employs exercises consistent with an ECP in this study. An injury was defined as a physical condition resulting from ECP participation that caused the athlete to either seek medical treatment, take time off from exercising, or make modifications to his or her technique to continue. Results: A total of 247 athletes (22%) completed the survey. The majority (57%) of athletes were male (n = 139), and 94% of athletes were white (n = 227). The mean age of athletes was 38.9 years (±8.9 years). Athletes reported participation in the ECP for, on average, 3.6 hours per week (± 1.2 hours). Eighty-five athletes (34%) reported that they had sustained an injury while participating in the ECP. A total of 132 injuries were recorded, yielding an estimated incidence of 2.71 per 1000 hours. The shoulder or upper arm was the most commonly injured body site, accounting for 38 injuries (15% of athletes). Athletes with a previous shoulder injury were 8.1 times as likely to injure their shoulder in the ECP compared with athletes with healthy shoulders. The trunk, back, head, or neck (n = 29, 12%) and the leg or knee (n = 29, 12%) were the second most commonly injured sites. The injury incidence rate among athletes with <6 months of experience in the ECP was 2.5 times greater than that of more experienced athletes (≥6 months of experience). Of the 132 injuries, 23 (17%) required surgical intervention. Squat cleans, ring dips, overhead squats, and push presses were more likely to cause injury. Athletes reported that 35% of injuries were due to overexertion and 20% were due to improper technique. Conclusion: The estimated injury rate among athletes participating in this ECP was similar to the rate of injury in weightlifting and most other recreational activities. The shoulder or upper arm was the most commonly injured area, and previous shoulder injury predisposed to new shoulder injury. New athletes are at considerable risk of injury compared with more experienced athletes. Clinical Relevance: Extreme conditioning programs are growing in popularity, and there is disagreement between science and anecdotal reports from athletes, coaches, and physicians about their relative safety. This study estimates the incidence of injury in extreme conditioning programs, which appears to be similar to other weight-training programs. PMID:27760844

Climate Exposure of US National Parks in a New Era of Change

PubMed Central

Monahan, William B.; Fisichelli, Nicholas A.

2014-01-01

US national parks are challenged by climate and other forms of broad-scale environmental change that operate beyond administrative boundaries and in some instances are occurring at especially rapid rates. Here, we evaluate the climate change exposure of 289 natural resource parks administered by the US National Park Service (NPS), and ask which are presently (past 10 to 30 years) experiencing extreme (<5th percentile or >95th percentile) climates relative to their 1901–2012 historical range of variability (HRV). We consider parks in a landscape context (including surrounding 30 km) and evaluate both mean and inter-annual variation in 25 biologically relevant climate variables related to temperature, precipitation, frost and wet day frequencies, vapor pressure, cloud cover, and seasonality. We also consider sensitivity of findings to the moving time window of analysis (10, 20, and 30 year windows). Results show that parks are overwhelmingly at the extreme warm end of historical temperature distributions and this is true for several variables (e.g., annual mean temperature, minimum temperature of the coldest month, mean temperature of the warmest quarter). Precipitation and other moisture patterns are geographically more heterogeneous across parks and show greater variation among variables. Across climate variables, recent inter-annual variation is generally well within the range of variability observed since 1901. Moving window size has a measureable effect on these estimates, but parks with extreme climates also tend to exhibit low sensitivity to the time window of analysis. We highlight particular parks that illustrate different extremes and may facilitate understanding responses of park resources to ongoing climate change. We conclude with discussion of how results relate to anticipated future changes in climate, as well as how they can inform NPS and neighboring land management and planning in a new era of change. PMID:24988483

Climate exposure of US national parks in a new era of change.

PubMed

Monahan, William B; Fisichelli, Nicholas A

2014-01-01

US national parks are challenged by climate and other forms of broad-scale environmental change that operate beyond administrative boundaries and in some instances are occurring at especially rapid rates. Here, we evaluate the climate change exposure of 289 natural resource parks administered by the US National Park Service (NPS), and ask which are presently (past 10 to 30 years) experiencing extreme (<5th percentile or >95th percentile) climates relative to their 1901-2012 historical range of variability (HRV). We consider parks in a landscape context (including surrounding 30 km) and evaluate both mean and inter-annual variation in 25 biologically relevant climate variables related to temperature, precipitation, frost and wet day frequencies, vapor pressure, cloud cover, and seasonality. We also consider sensitivity of findings to the moving time window of analysis (10, 20, and 30 year windows). Results show that parks are overwhelmingly at the extreme warm end of historical temperature distributions and this is true for several variables (e.g., annual mean temperature, minimum temperature of the coldest month, mean temperature of the warmest quarter). Precipitation and other moisture patterns are geographically more heterogeneous across parks and show greater variation among variables. Across climate variables, recent inter-annual variation is generally well within the range of variability observed since 1901. Moving window size has a measureable effect on these estimates, but parks with extreme climates also tend to exhibit low sensitivity to the time window of analysis. We highlight particular parks that illustrate different extremes and may facilitate understanding responses of park resources to ongoing climate change. We conclude with discussion of how results relate to anticipated future changes in climate, as well as how they can inform NPS and neighboring land management and planning in a new era of change.

Schools Leaders Successfully Partner with Community Organization: Providing Nutrition so Students Focus on Learning Instead of on Hunger

ERIC Educational Resources Information Center

Hipsky, Shellie; Scigliano, Deborah; Parker, David

2013-01-01

Due to the closing of the GM Manufacturing Plants, Grand Rapids, Michigan area experienced an extreme loss of jobs, which led to low-socioeconomic hardships such as "food insecurity" that was witnessed in the needs of the many students who attend the Grand Rapid Public Schools. This case provides insight into how educational leader…

The Peak Structure and Future Changes of the Relationships Between Extreme Precipitation and Temperature

NASA Technical Reports Server (NTRS)

Wang, Guiling; Wang, Dagang; Trenberth, Kevin E.; Erfanian, Amir; Yu, Miao; Bosilovich, Michael G.; Parr, Dana T.

2017-01-01

Theoretical models predict that, in the absence of moisture limitation, extreme precipitation intensity could exponentially increase with temperatures at a rate determined by the Clausius-Clapeyron (C-C) relationship. Climate models project a continuous increase of precipitation extremes for the twenty-first century over most of the globe. However, some station observations suggest a negative scaling of extreme precipitation with very high temperatures, raising doubts about future increase of precipitation extremes. Here we show for the present-day climate over most of the globe,the curve relating daily precipitation extremes with local temperatures has a peak structure, increasing as expected at the low medium range of temperature variations but decreasing at high temperatures. However, this peak-shaped relationship does not imply a potential upper limit for future precipitation extremes. Climate models project both the peak of extreme precipitation and the temperature at which it peaks (T(sub peak)) will increase with warming; the two increases generally conform to the C-C scaling rate in mid- and high-latitudes,and to a super C-C scaling in most of the tropics. Because projected increases of local mean temperature (T(sub mean)) far exceed projected increases of T(sub peak) over land, the conventional approach of relating extreme precipitation to T(sub mean) produces a misleading sub-C-C scaling rate.

North Korea. A Climatological Study

DTIC Science & Technology

1994-08-01

wish to thank the many unknown DoD meteorologists who served in and aroundbthe Korean Peninsula since World War H. Their contributions, much of which...rivers rise rapidly; 60s to lower 70s. Extreme highs have reached the Yalu has reached 26 feet, while the Imjin (near 1000; extreme lows of 320 have been...Battle Planners, US Naval War College, 1988. S Summary of Synoptic Meteorological Observations-Japanese and Korean Coastal Marine Areas- BIB-1 Volume 8

THE ACTION OF EXTREME COLD ON LEUKEMIC CELLS OF MICE

PubMed Central

Breedis, Charles

1942-01-01

Suspensions of leukemic cells of mice from three different strains of leukemia were subjected to rapid or slow freezing and rapid or slow thawing. Suspensions rapidly frozen to –196°C. were in all cases innocuous, whereas those frozen slowly were capable of transmitting leukemia. The infectivity of slowly frozen material varied from an estimated 0.0001 per cent to 1 per cent of that of fresh material, and this figure probably represents the percentage of surviving leukemic cells. Particles of spleen and lymph node reacted to slow and rapid freezing in the same manner as suspensions prepared from them. For one of the strains rapid thawing was less injurious than slow thawing; for the other two the rate of thawing seemed to be immaterial. Infectivity was equally well preserved after freezing to –21°C. whether freezing occurred spontaneously after supercooling or was initiated near the freezing point by inoculation with ice, or whether thawing was slow or rapid. Suspensions already slowly frozen at temperatures of –2° or lower, whether spontaneously or by inoculation with ice, could no longer be completely inactivated by subsequent rapid cooling to –196°C. Unfrozen suspensions initially above the freezing point or supercooled to –2°C. or –8°C. and then rapidly cooled to –196°C. were inactivated. This protective action of previous slow freezing was most marked when the initial temperature of the frozen suspension was –15°C. or lower; when it was –2°C. protection was barely detected. These observations indicate that the changes which are peculiar to rapid freezing alone and lead to complete inactivation take place during rapid transition from the liquid to the solid state, in a range of temperature lying between –15°C. and the freezing point. Temperature measurements carried out in this range showed that suspensions were about equally infections whether the temperature at their centers dropped from 0°C. to –15°C. in 30 minutes or in 1 minute; when the drop occurred in 12 seconds or less, the suspensions became innocuous. PMID:19871231

Temporal dynamics of CO 2 and CH 4 loss potentials in response to rapid hydrological shifts in tidal freshwater wetland soils

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

RoyChowdhury, Taniya; Bramer, Lisa; Hoyt, David W.

Earth System Models predict climate extremes that will impact regional and global hydrology. Aquatic-terrestrial transition zones like wetlands are subjected to the immediate consequence of climate change with shifts in the magnitude and dynamics of hydrologic flow. Such fluctuating hydrology can alter the nature and rate of biogeochemical transformations and significantly impact the carbon balance of the ecosystem. We tested the impacts of fluctuating hydrology and, specifically, the role of antecedent moisture conditions in determining the dominant carbon loss mechanisms in soils sampled from a tidal freshwater wetland system in the lower Columbia River, WA, USA. The objective was tomore » understand shifts in biogeochemical processes in response to changing soil moisture, based on soil respiration and methane production rates, and to elucidate such responses based on the observed electron acceptor and metabolite profiles under laboratory conditions. Metabolomics and biogeochemical process rates provided evidence that soil redox was the principal factor driving metabolic function. Fluctuating redox conditions altered terminal electron acceptor and donor availability and recovery strengths of their concentrations in soil such that a disproportionate release of carbon dioxide stemmed from alternative anaerobic degradation processes like sulfate and iron reduction compared to carbon loss due to methanogenesis. These results show that extended and short-term saturation created conditions conducive to increasing metabolite availability for anaerobic decomposition processes, with a significant lag in methanogenesis. In contrast, extended drying caused a cellular-level stress response and rapid recycling of alternate electron acceptors.« less

Temporal dynamics of CO 2 and CH 4 loss potentials in response to rapid hydrological shifts in tidal freshwater wetland soils

DOE PAGES

RoyChowdhury, Taniya; Bramer, Lisa; Hoyt, David W.; ...

2017-06-27

Earth System Models predict climate extremes that will impact regional and global hydrology. Aquatic-terrestrial transition zones like wetlands are subjected to the immediate consequence of climate change with shifts in the magnitude and dynamics of hydrologic flow. Such fluctuating hydrology can alter the nature and rate of biogeochemical transformations and significantly impact the carbon balance of the ecosystem. We tested the impacts of fluctuating hydrology and, specifically, the role of antecedent moisture conditions in determining the dominant carbon loss mechanisms in soils sampled from a tidal freshwater wetland system in the lower Columbia River, WA, USA. The objective was tomore » understand shifts in biogeochemical processes in response to changing soil moisture, based on soil respiration and methane production rates, and to elucidate such responses based on the observed electron acceptor and metabolite profiles under laboratory conditions. Metabolomics and biogeochemical process rates provided evidence that soil redox was the principal factor driving metabolic function. Fluctuating redox conditions altered terminal electron acceptor and donor availability and recovery strengths of their concentrations in soil such that a disproportionate release of carbon dioxide stemmed from alternative anaerobic degradation processes like sulfate and iron reduction compared to carbon loss due to methanogenesis. These results show that extended and short-term saturation created conditions conducive to increasing metabolite availability for anaerobic decomposition processes, with a significant lag in methanogenesis. In contrast, extended drying caused a cellular-level stress response and rapid recycling of alternate electron acceptors.« less

Positive Selection in Rapidly Evolving Plastid–Nuclear Enzyme Complexes

PubMed Central

Rockenbach, Kate; Havird, Justin C.; Monroe, J. Grey; Triant, Deborah A.; Taylor, Douglas R.; Sloan, Daniel B.

2016-01-01

Rates of sequence evolution in plastid genomes are generally low, but numerous angiosperm lineages exhibit accelerated evolutionary rates in similar subsets of plastid genes. These genes include clpP1 and accD, which encode components of the caseinolytic protease (CLP) and acetyl-coA carboxylase (ACCase) complexes, respectively. Whether these extreme and repeated accelerations in rates of plastid genome evolution result from adaptive change in proteins (i.e., positive selection) or simply a loss of functional constraint (i.e., relaxed purifying selection) is a source of ongoing controversy. To address this, we have taken advantage of the multiple independent accelerations that have occurred within the genus Silene (Caryophyllaceae) by examining phylogenetic and population genetic variation in the nuclear genes that encode subunits of the CLP and ACCase complexes. We found that, in species with accelerated plastid genome evolution, the nuclear-encoded subunits in the CLP and ACCase complexes are also evolving rapidly, especially those involved in direct physical interactions with plastid-encoded proteins. A massive excess of nonsynonymous substitutions between species relative to levels of intraspecific polymorphism indicated a history of strong positive selection (particularly in CLP genes). Interestingly, however, some species are likely undergoing loss of the native (heteromeric) plastid ACCase and putative functional replacement by a duplicated cytosolic (homomeric) ACCase. Overall, the patterns of molecular evolution in these plastid–nuclear complexes are unusual for anciently conserved enzymes. They instead resemble cases of antagonistic coevolution between pathogens and host immune genes. We discuss a possible role of plastid–nuclear conflict as a novel cause of accelerated evolution. PMID:27707788

Quantitative assessment of motor speech abnormalities in idiopathic rapid eye movement sleep behaviour disorder.

PubMed

Rusz, Jan; Hlavnička, Jan; Tykalová, Tereza; Bušková, Jitka; Ulmanová, Olga; Růžička, Evžen; Šonka, Karel

2016-03-01

Patients with idiopathic rapid eye movement sleep behaviour disorder (RBD) are at substantial risk for developing Parkinson's disease (PD) or related neurodegenerative disorders. Speech is an important indicator of motor function and movement coordination, and therefore may be an extremely sensitive early marker of changes due to prodromal neurodegeneration. Speech data were acquired from 16 RBD subjects and 16 age- and sex-matched healthy control subjects. Objective acoustic assessment of 15 speech dimensions representing various phonatory, articulatory, and prosodic deviations was performed. Statistical models were applied to characterise speech disorders in RBD and to estimate sensitivity and specificity in differentiating between RBD and control subjects. Some form of speech impairment was revealed in 88% of RBD subjects. Articulatory deficits were the most prominent findings in RBD. In comparison to controls, the RBD group showed significant alterations in irregular alternating motion rates (p = 0.009) and articulatory decay (p = 0.01). The combination of four distinctive speech dimensions, including aperiodicity, irregular alternating motion rates, articulatory decay, and dysfluency, led to 96% sensitivity and 79% specificity in discriminating between RBD and control subjects. Speech impairment was significantly more pronounced in RBD subjects with the motor score of the Unified Parkinson's Disease Rating Scale greater than 4 points when compared to other RBD individuals. Simple quantitative speech motor measures may be suitable for the reliable detection of prodromal neurodegeneration in subjects with RBD, and therefore may provide important outcomes for future therapy trials. Copyright © 2015 Elsevier B.V. All rights reserved.

Patterns, rates and possible causes of saltmarsh erosion in the Greater Thames area (UK)

NASA Astrophysics Data System (ADS)

van der Wal, Daphne; Pye, Kenneth

2004-08-01

The estuary-dominated coast of the Greater Thames in England has experienced rapid lateral erosion and internal dissection of saltmarshes. This paper provides an overview of saltmarsh development in this area, and re-examines the role of environmental and human forcing factors. It draws on documentary evidence, including historical maps, survey data and time-series data of forcing factors. Lateral marsh retreat began in the 19th century in the Medway and Blackwater Estuaries, followed by other estuaries in the Greater Thames region at the beginning of the 20th century. The outer estuaries and the wider parts of the inner estuaries especially have experienced erosion. Erosion has been modest in wave-sheltered areas, e.g., the Colne and the inner Crouch. In the 1960s and, more widely, the 1970s, a phase of rapid erosion took place, with erosion rates of up to ca. 16 ha year -1 per site, notably along the open coast of Dengie and Foulness, and in the Blackwater and Thames Estuaries. At all sites, vertical sediment accretion was well able to keep up with sea level rise over the past century. Evidence indicates that there may have been several causes for the erosion of saltmarshes. These are notably land claim and embankment construction (increasing the tidal range and current velocities) and a continuous rise of, especially, high and extreme water levels. The latest episode of rapid erosion in the 1970s is largely attributed to changes in the wind/wave climate. For example, erosion at wave-exposed sites coincided with a peak in high magnitude waves combined with a high incidence of southeasterly waves. The study shows that many factors, including natural forcing factors and human activities, have to be taken into account when explaining saltmarsh development.

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

Drout, M. R.; Soderberg, A. M.; Margutti, R.

We present extensive multi-wavelength observations of the extremely rapidly declining Type Ic supernova (SN Ic), SN 2005ek. Reaching a peak magnitude of M{sub R} = -17.3 and decaying by {approx}3 mag in the first 15 days post-maximum, SN 2005ek is among the fastest Type I supernovae observed to date. The spectra of SN 2005ek closely resemble those of normal SN Ic, but with an accelerated evolution. There is evidence for the onset of nebular features at only nine days post-maximum. Spectroscopic modeling reveals an ejecta mass of {approx}0.3 M{sub Sun} that is dominated by oxygen ({approx}80%), while the pseudo-bolometric lightmore » curve is consistent with an explosion powered by {approx}0.03 M{sub Sun} of radioactive {sup 56}Ni. Although previous rapidly evolving events (e.g., SN 1885A, SN 1939B, SN 2002bj, SN 2010X) were hypothesized to be produced by the detonation of a helium shell on a white dwarf, oxygen-dominated ejecta are difficult to reconcile with this proposed mechanism. We find that the properties of SN 2005ek are consistent with either the edge-lit double detonation of a low-mass white dwarf or the iron-core collapse of a massive star, stripped by binary interaction. However, if we assume that the strong spectroscopic similarity of SN 2005ek to other SNe Ic is an indication of a similar progenitor channel, then a white-dwarf progenitor becomes very improbable. SN 2005ek may be one of the lowest mass stripped-envelope core-collapse explosions ever observed. We find that the rate of such rapidly declining Type I events is at least 1%-3% of the normal SN Ia rate.« less

Extreme weather events in Iran under a changing climate

NASA Astrophysics Data System (ADS)

Alizadeh-Choobari, Omid; Najafi, M. S.

2018-01-01

Observations unequivocally show that Iran has been rapidly warming over recent decades, which in sequence has triggered a wide range of climatic impacts. Meteorological records of several ground stations across Iran with daily temporal resolution for the period 1951-2013 were analyzed to investigate the climate change and its impact on some weather extremes. Iran has warmed by nearly 1.3 °C during the period 1951-2013 (+0.2 °C per decade), with an increase of the minimum temperature at a rate two times that of the maximum. Consequently, an increase in the frequency of heat extremes and a decrease in the frequency of cold extremes have been observed. The annual precipitation has decreased by 8 mm per decade, causing an expansion of Iran's dry zones. Previous studies have pointed out that warming is generally associated with more frequent heavy precipitation because a warmer air can hold more moisture. Nevertheless, warming in Iran has been associated with more frequent light precipitation, but less frequent moderate, heavy and extremely heavy precipitation. This is because in the subtropical dry zones, a longer time is required to recharge the atmosphere with water vapour in a warmer climate, causing more water vapour to be transported from the subtropics to high latitudes before precipitations forms. In addition, the altitude of the condensation level increases in a warmer climate in subtropical regions, causing an overall decrease of precipitation. We argue that changing in the frequency of heavy precipitation in response to warming varies depending on the geographical location. Warming over the dry subtropical regions is associated with a decrease in the frequency of heavy precipitation, while an increase is expected over both subpolar and tropical regions. The warmer climate has also led to the increase in the frequency of both thunderstorms (driven by convective heating) and dust events over Iran.

Mechanical characterization of alloys in extreme conditions of high strain rates and high temperature

NASA Astrophysics Data System (ADS)

Cadoni, Ezio

2018-03-01

The aim of this paper is the description of the mechanical characterization of alloys under extreme conditions of temperature and loading. In fact, in the frame of the Cost Action CA15102 “Solutions for Critical Raw Materials Under Extreme Conditions (CRM-EXTREME)” this aspect is crucial and many industrial applications have to consider the dynamic response of materials. Indeed, for a reduction and substitution of CRMs in alloys is necessary to design the materials and understand if the new materials behave better or if the substitution or reduction badly affect their performance. For this reason, a deep knowledge of the mechanical behaviour at high strain-rates of considered materials is required. In general, machinery manufacturing industry or transport industry as well as energy industry have important dynamic phenomena that are simultaneously affected by extended strain, high strain-rate, damage and pressure, as well as conspicuous temperature gradients. The experimental results in extreme conditions of high strain rate and high temperature of an austenitic stainless steel as well as a high-chromium tempered martensitic reduced activation steel Eurofer97 are presented.

The incidences of and consultation rate for lower extremity complaints in general practice

PubMed Central

van der Waal, J M; Bot, S D M; Terwee, C B; van der Windt, D A W M; Schellevis, F G; Bouter, L M; Dekker, J

2006-01-01

Objective To estimate the incidence and consultation rate of lower extremity complaints in general practice. Methods Data were obtained from the Second Dutch National Survey of General Practice, in which 195 general practitioners (GPs) in 104 practices recorded all contacts with patients during 12 consecutive months in computerised patient records. GPs classified the symptoms and diagnosis for each patient at each consultation according to the International Classification of Primary Care (ICPC). Incidence densities and consultation rates for different complaints were calculated. Results During the registration period 63.2 GP consultations per 1000 person‐years were attributable to a new complaint of the lower extremities. Highest incidence densities were seen for knee complaints: 21.4 per 1000 person‐years for women and 22.8 per 1000 person‐years for men. The incidence of most lower extremity complaints was higher for women than for men and higher in older age. Conclusions Both incidences of and consultation rates for lower extremity complaints are substantial in general practice. This implies a considerable impact on the workload of the GP. PMID:16269430

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

Janowiecki, Steven; Salzer, John J.; Zee, Liese van

We discuss and test possible evolutionary connections between blue compact dwarf galaxies (BCDs) and other types of dwarf galaxies. BCDs provide ideal laboratories to study intense star formation episodes in low-mass dwarf galaxies, and have sometimes been considered a short-lived evolutionary stage between types of dwarf galaxies. To test these connections, we consider a sample of BCDs as well as a comparison sample of nearby galaxies from the Local Volume Legacy (LVL) survey for context. We fit the multi-wavelength spectral energy distributions (SED, far-ultra-violet to far-infrared) of each galaxy with a grid of theoretical models to determine their stellar massesmore » and star formation properties. We compare our results for BCDs with the LVL galaxies to put BCDs in the context of normal galaxy evolution. The SED fits demonstrate that the star formation events currently underway in BCDs are at the extreme of the continuum of normal dwarf galaxies, both in terms of the relative mass involved and in the relative increase over previous star formation rates. Today’s BCDs are distinctive objects in a state of extreme star formation that is rapidly transforming them. This study also suggests ways to identify former BCDs whose star formation episodes have since faded.« less

Studies in useful hard x-ray induced chemistry

NASA Astrophysics Data System (ADS)

Pravica, Michael; Bai, Ligang; Sneed, Daniel; Park, Changyong

2013-06-01

The observed rapid decomposition of potassium chlorate (via 2KClO3 + h ν --> 2KCl +3O2) via synchrotron hard x-ray irradiation (>10 keV) has enabled experiments that are developing novel and useful hard x-ray chemistry. We have observed a number of radiation-induced in situ decomposition reactions in various substances which release O2, H2, N2, NH3, and H2O in a diamond anvil cell (DAC) at ambient and high pressures. These novel acatalytic and isothermal reactions represent a highly controllable, penetrating, and focused method to initiate chemistry (including x-ray induced combustion) in sealed and/or isolated chambers which maintain matter under extreme conditions. During our studies, we have typically observed a slowing of decomposition with pressure including phase dependent decomposition of KClO3. Energy dependent studies have observed an apparent resonance near 15 keV at which the decomposition rate is maximized. This may enable use of much lower flux and portable x-ray sources (e.g. x-ray tubes) in larger scale experiments. These developments support novel means to load DACs and control chemical reactions providing novel routes of synthesis of novel materials under extreme conditions.

Fast, Simple and Accurate Handwritten Digit Classification by Training Shallow Neural Network Classifiers with the ‘Extreme Learning Machine’ Algorithm

PubMed Central

McDonnell, Mark D.; Tissera, Migel D.; Vladusich, Tony; van Schaik, André; Tapson, Jonathan

2015-01-01

Recent advances in training deep (multi-layer) architectures have inspired a renaissance in neural network use. For example, deep convolutional networks are becoming the default option for difficult tasks on large datasets, such as image and speech recognition. However, here we show that error rates below 1% on the MNIST handwritten digit benchmark can be replicated with shallow non-convolutional neural networks. This is achieved by training such networks using the ‘Extreme Learning Machine’ (ELM) approach, which also enables a very rapid training time (∼ 10 minutes). Adding distortions, as is common practise for MNIST, reduces error rates even further. Our methods are also shown to be capable of achieving less than 5.5% error rates on the NORB image database. To achieve these results, we introduce several enhancements to the standard ELM algorithm, which individually and in combination can significantly improve performance. The main innovation is to ensure each hidden-unit operates only on a randomly sized and positioned patch of each image. This form of random ‘receptive field’ sampling of the input ensures the input weight matrix is sparse, with about 90% of weights equal to zero. Furthermore, combining our methods with a small number of iterations of a single-batch backpropagation method can significantly reduce the number of hidden-units required to achieve a particular performance. Our close to state-of-the-art results for MNIST and NORB suggest that the ease of use and accuracy of the ELM algorithm for designing a single-hidden-layer neural network classifier should cause it to be given greater consideration either as a standalone method for simpler problems, or as the final classification stage in deep neural networks applied to more difficult problems. PMID:26262687

No effect of season on the electrocardiogram of long-eared bats (Nyctophilus gouldi) during torpor.

PubMed

Currie, Shannon E

2018-04-05

Heterothermic animals regularly undergo profound alterations of cardiac function associated with torpor. These animals have specialised tissues capable of withstanding fluctuations in body temperature > 30 °C without adverse effects. In particular, the hearts of heterotherms are able to resist fibrillation and discontinuity of the cardiac conduction system common in homeotherms during hypothermia. To investigate the patterns of cardiac conduction in small insectivorous bats which enter torpor year round, I simultaneously measured ECG and subcutaneous temperature (T sub ) of 21 Nyctophilus gouldi (11 g) during torpor at a range of ambient temperatures (T a 1-28 °C). During torpor cardiac conduction slowed in a temperature dependent manner, primarily via prolongation along the atrioventricular pathway (PR interval). A close coupling of depolarisation and repolarisation was retained in torpid bats, with no isoelectric ST segment visible until animals reached T sub <6 °C. There was little change in ventricular repolarisation (JT interval) with decreasing T sub , or between rest and torpor at mild T a . Bats retained a more rapid rate of ventricular conduction and repolarisation during torpor relative to other hibernators. Throughout all recordings across seasons (> 2500 h), there was no difference in ECG morphology or heart rate during torpor, and no manifestations of significant conduction blocks or ventricular tachyarrhythmias were observed. My results demonstrate the capacity of bat hearts to withstand extreme fluctuations in rate and temperature throughout the year without detrimental arrhythmogenesis. I suggest that this conduction reserve may be related to flight and the daily extremes in metabolism experienced by these animals, and warrants further investigation of cardiac electrophysiology in other flying hibernators.

Death of the bee hive: understanding the failure of an insect society.

PubMed

Barron, Andrew B

2015-08-01

Since 2007 honey bee colony failure rates overwinter have averaged about 30% across much of North America. In addition, cases of extremely rapid colony failure have been reported, which has been termed colony collapse disorder. Both phenomena result from an increase in the frequency and intensity of chronic diseases and environmental stressors. Colonies are often challenged by multiple stressors, which can interact: for example, pesticides can enhance disease transmission in colonies. Colonies may be particularly vulnerable to sublethal effects of pathogens and pesticides since colony functions are compromised whether a stressor kills workers, or causes them to fail at foraging. Modelling provides a way to understand the processes of colony failure by relating impacts of stressors to colony-level functions. Copyright © 2015 Elsevier Inc. All rights reserved.

Test drilling in basalts, Lalamilo area, South Kohala District, Hawaii

USGS Publications Warehouse

Teasdale, Warren E.

1980-01-01

Test drilling has determined that a downhole-percussion airhammer can be used effectively to drill basalts in Hawaii. When used in conjunction with a foam-type drilling fluid, the hammer-bit penetration rate was rapid. Continuous drill cuttings from the materials penetrated were obtained throughout the borehole except from extremely fractured or weathered basalt zones where circulation was lost or limited. Cementing of these zones as soon as encountered reduced problems of stuck tools, washouts, and loss of drill-cuttings. Supplies and logistics on the Hawaiian Islands, always a major concern, require that all anticipated drilling supplies, spare rig and tool parts, drilling muds and additives, foam, and miscellaneous hardware be on hand before starting to drill. If not, the resulting rig downtime is costly in both time and money. (USGS)

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

Qiao, Xianfeng, E-mail: qiaoxianfeng@hotmail.com; Zhao, Chen; Chen, Bingbing

This paper reports a trap-induced photoconductivity in ITO/pentacene/Al diodes by using current-voltage and magneto-conductance measurements. The comparison of photoconductivity between pentacene diodes with and without trap clearly shows that the traps play a critical role in generating photoconductivity. It shows that no observable photoconductivity is detected for trap-free pentacene diodes, while significant photoconductivity is observed in diodes with trap. This is because the initial photogenerated singlet excitons in pentacene can rapidly split into triplet excitons with higher binding energy prior to dissociating into free charge carriers. The generated triplet excitons react with trapped charges to release charge-carriers from traps, leadingmore » to a trap-induced photoconductivity in the single-layer pentacene diodes. Our studies elucidated the formation mechanisms of photoconductivity in pentacene diodes with extremely fast singlet fission rate.« less

Trap-induced photoconductivity in singlet fission pentacene diodes

NASA Astrophysics Data System (ADS)

Qiao, Xianfeng; Zhao, Chen; Chen, Bingbing; Luan, Lin

2014-07-01

This paper reports a trap-induced photoconductivity in ITO/pentacene/Al diodes by using current-voltage and magneto-conductance measurements. The comparison of photoconductivity between pentacene diodes with and without trap clearly shows that the traps play a critical role in generating photoconductivity. It shows that no observable photoconductivity is detected for trap-free pentacene diodes, while significant photoconductivity is observed in diodes with trap. This is because the initial photogenerated singlet excitons in pentacene can rapidly split into triplet excitons with higher binding energy prior to dissociating into free charge carriers. The generated triplet excitons react with trapped charges to release charge-carriers from traps, leading to a trap-induced photoconductivity in the single-layer pentacene diodes. Our studies elucidated the formation mechanisms of photoconductivity in pentacene diodes with extremely fast singlet fission rate.

Changes in Extremely Hot Summers over the Global Land Area under Various Warming Targets.

PubMed

Wang, Lei; Huang, Jianbin; Luo, Yong; Yao, Yao; Zhao, Zongci

2015-01-01

Summer temperature extremes over the global land area were investigated by comparing 26 models of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) with observations from the Goddard Institute for Space Studies (GISS) and the Climate Research Unit (CRU). Monthly data of the observations and models were averaged for each season, and statistics were calculated for individual models before averaging them to obtain ensemble means. The summers with temperature anomalies (relative to 1951-1980) exceeding 3σ (σ is based on the local internal variability) are defined as "extremely hot". The models well reproduced the statistical characteristics evolution, and partly captured the spatial distributions of historical summer temperature extremes. If the global mean temperature increases 2°C relative to the pre-industrial level, "extremely hot" summers are projected to occur over nearly 40% of the land area (multi-model ensemble mean projection). Summers that exceed 5σ warming are projected to occur over approximately 10% of the global land area, which were rarely observed during the reference period. Scenarios reaching warming levels of 3°C to 5°C were also analyzed. After exceeding the 5°C warming target, "extremely hot" summers are projected to occur throughout the entire global land area, and summers that exceed 5σ warming would become common over 70% of the land area. In addition, the areas affected by "extremely hot" summers are expected to rapidly expand by more than 25%/°C as the global mean temperature increases by up to 3°C before slowing to less than 16%/°C as the temperature continues to increase by more than 3°C. The area that experiences summers with warming of 5σ or more above the warming target of 2°C is likely to maintain rapid expansion of greater than 17%/°C. To reduce the impacts and damage from severely hot summers, the global mean temperature increase should remain low.

Distraction rate and latency: factors in the outcome of paediatric maxillary distraction.

PubMed

Higuera, Stephen; Cole, Patrick; Stephenson, J B; Hollier, Larry

2009-12-01

Over 50 years ago, current tenets of distraction osteogenesis were developed through work on the lower extremity; however, the application of these tenets in the paediatric craniofacial skeleton remains questionable. Prompted by recent concern that traditional aspects of distraction may be either outdated or wholly inapplicable to the paediatric maxilla, we retrospectively evaluated maxillary distraction protocol using a 24-h latency period in conjunction with a distraction rate of 2mm/day. Following maxillary advancement via a distraction protocol consisting of a 24-h latency period and a distraction rate of 2mm/day, seven consecutive paediatric cases were evaluated. Standard profile photos and cephalometric films taken preoperatively, at device removal and at 1-year follow-up were compared. With the sella as the point of registration, pre- and post-distraction films were superimposed on the sella-nasion plane. Sella-nasion-subspinale, the angle of convexity, the distance from incisal edges to the y-axis, and angulation of the upper incisor to the sella-nasion plane were analysed to evaluate hard-tissue changes. Patient age ranged from 3 to 14 years (mean=7.43 years). Maxillary distraction length averaged 11 mm (range=10-12 mm). Interval from device application to removal averaged 98 days (range=75-180 days). The interval of the active distraction ranged from 11 to 65 days (mean=24 days). From distraction completion to device removal averaged 85 days (range=60-150). Follow-up intervals ranged from 52 to 24 months (mean=34 months). All patients demonstrated substantial clinical advancement of the maxilla with correction of midfacial deficiencies. A single patient developed mild cellulitis at one skin-device interface; no other complications were noted. Cephalometric and clinical evaluations at 1 year post-distraction demonstrated stable results, and parental satisfaction was qualitatively high. The surgical dogma of lower-extremity distraction osteogenesis is not absolute and may not be optimal for use in the paediatric maxilla. Our results demonstrate effective maxillary correction following application of a 24-h latency period coupled with rapid distraction at 2mm/day. Our success with a short latency period and more rapid device expanse may be a product of the significant vascularity and improved healing potential of the paediatric maxilla.

Extreme Weather Events and Climate Change Attribution

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

Thomas, Katherine

A report from the National Academies of Sciences, Engineering, and Medicine concludes it is now possible to estimate the influence of climate change on some types of extreme events. The science of extreme event attribution has advanced rapidly in recent years, giving new insight to the ways that human-caused climate change can influence the magnitude or frequency of some extreme weather events. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities. Confidence is strongest in attributing types of extreme events that are influenced by climatemore » change through a well-understood physical mechanism, such as, the more frequent heat waves that are closely connected to human-caused global temperature increases, the report finds. Confidence is lower for other types of events, such as hurricanes, whose relationship to climate change is more complex and less understood at present. For any extreme event, the results of attribution studies hinge on how questions about the event's causes are posed, and on the data, modeling approaches, and statistical tools chosen for the analysis.« less

The Evaluative Lexicon 2.0: The measurement of emotionality, extremity, and valence in language.

PubMed

Rocklage, Matthew D; Rucker, Derek D; Nordgren, Loran F

2017-10-19

The rapid expansion of the Internet and the availability of vast repositories of natural text provide researchers with the immense opportunity to study human reactions, opinions, and behavior on a massive scale. To help researchers take advantage of this new frontier, the present work introduces and validates the Evaluative Lexicon 2.0 (EL 2.0)-a quantitative linguistic tool that specializes in the measurement of the emotionality of individuals' evaluations in text. Specifically, the EL 2.0 utilizes natural language to measure the emotionality, extremity, and valence of evaluative reactions and attitudes. The present article describes how we used a combination of 9 million real-world online reviews and over 1,500 participant judges to construct the EL 2.0 and an additional 5.7 million reviews to validate it. To assess its unique value, the EL 2.0 is compared with two other prominent text analysis tools-LIWC and Warriner et al.'s (Behavior Research Methods, 45, 1191-1207, 2013) wordlist. The EL 2.0 is comparatively distinct in its ability to measure emotionality and explains a significantly greater proportion of the variance in individuals' evaluations. The EL 2.0 can be used with any data that involve speech or writing and provides researchers with the opportunity to capture evaluative reactions both in the laboratory and "in the wild." The EL 2.0 wordlist and normative emotionality, extremity, and valence ratings are freely available from www.evaluativelexicon.com .

Cryptococcoma mimicking a brain tumor in an immunocompetent patient: case report of an extremely rare presentation.

PubMed

Paiva, Aline Lariessy Campos; Aguiar, Guilherme Brasileiro de; Lovato, Renan Maximilian; Zanetti, Arthus Vilar Deolindo; Panagopoulos, Alexandros Theodoros; Veiga, José Carlos Esteves

2017-11-06

Central nervous system (CNS) infectious diseases have high prevalence in developing countries and their proper diagnosis and treatment are very important for public health planning. Cryptococcus neoformans is a fungus that may cause several CNS manifestations, especially in immunocompromised patients. Cryptococcal meningitis is the most common type of involvement. Mass-effect lesions are uncommon: they are described as cryptococcomas and their prevalence is even lower among immunocompetent patients. The aim here was to report an extremely rare case of cryptococcoma causing a mass effect and mimicking a brain tumor in an immunocompetent patient. The literature on CNS cryptococcal infections was reviewed with emphasis on cryptococcomas. Clinical, surgical and radiological data on a female patient with this rare presentation of cryptococcoma mimicking a brain tumor are described. A 54-year-old female patient presented to the emergency department with a rapid-onset progressive history of confusion and completely dependency for basic activities. Neuroimaging showed a left occipital lesion and neurosurgical treatment was proposed. From histopathological evaluation, a diagnosis of cryptococcoma was established. She received clinical support with antifungals, but despite optimal clinical treatment, her condition evolved to death. Cryptococcal infections have several forms of presentation and, in immunocompetent patients, their manifestation may be even more different. Cryptococcoma is an extremely rare presentation in which proper surgical and clinical treatment should be instituted as quickly as possible, but even so, there is a high mortality rate.

Applications of Extreme Value Theory in Public Health.

PubMed

Thomas, Maud; Lemaitre, Magali; Wilson, Mark L; Viboud, Cécile; Yordanov, Youri; Wackernagel, Hans; Carrat, Fabrice

2016-01-01

We present how Extreme Value Theory (EVT) can be used in public health to predict future extreme events. We applied EVT to weekly rates of Pneumonia and Influenza (P&I) deaths over 1979-2011. We further explored the daily number of emergency department visits in a network of 37 hospitals over 2004-2014. Maxima of grouped consecutive observations were fitted to a generalized extreme value distribution. The distribution was used to estimate the probability of extreme values in specified time periods. An annual P&I death rate of 12 per 100,000 (the highest maximum observed) should be exceeded once over the next 30 years and each year, there should be a 3% risk that the P&I death rate will exceed this value. Over the past 10 years, the observed maximum increase in the daily number of visits from the same weekday between two consecutive weeks was 1133. We estimated at 0.37% the probability of exceeding a daily increase of 1000 on each month. The EVT method can be applied to various topics in epidemiology thus contributing to public health planning for extreme events.

Experimental study on the signs of particulate structures formation in annular geometry of rapid granular shear flows

NASA Astrophysics Data System (ADS)

Ritvanen, J.; Jalali, P.

2009-06-01

Rapid granular shear flow is a classical example in granular materials which exhibits both fluid-like and solid-like behaviors. Another interesting feature of rapid granular shear flows is the formation of ordered structures upon shearing. Certain amount of granular material, with uniform size distribution, is required to be loaded in the container in order to shear it under stable conditions. This work concerns the experimental study of rapid granular shear flows in annular Couette geometry. The flow is induced by continuous rotation of the plate over the top of the granular bed in an annulus. The compressive pressure, driving torque, instantaneous bed height from three symmetric locations and rotational speed of the shearing plate are measured. The annulus has a capacity of up to 15 kg of spherical steel balls of 3 mm in diameter. Rapid shear flow experiments are performed in one compressive force and rotation rate. The sensitivity of fluctuations is then investigated by different means through monodisperse packing. In this work, we present the results of the experiments showing how the flow properties depend on the amount of loaded granular material which is varied by small amounts between different experiments. The flow can exist in stable (fixed behavior) and unstable (time-dependent behavior) regimes as a function of the loaded material. We present the characteristics of flow to detect the formation of any additional structured layer in the annulus. As a result, an evolution graph for the bed height has been obtained as material is gradually added. This graph shows how the bed height grows when material increases. Using these results, the structure inside the medium can be estimated at extreme stable and unstable conditions.

Rapid enhancement of chemical weathering recorded by extremely light seawater lithium isotopes at the Permian–Triassic boundary

PubMed Central

Sun, He; Xiao, Yilin; Zhang, Guijie; Casey, John F.; Shen, Yanan

2018-01-01

Lithium (Li) isotope analyses of sedimentary rocks from the Meishan section in South China reveal extremely light seawater Li isotopic signatures at the Permian–Triassic boundary (PTB), which coincide with the most severe mass extinction in the history of animal life. Using a dynamic seawater lithium box model, we show that the light seawater Li isotopic signatures can be best explained by a significant influx of riverine [Li] with light δ7Li to the ocean realm. The seawater Li isotope excursion started ≥300 Ky before and persisted up to the main extinction event, which is consistent with the eruption time of the Siberian Traps. The eruption of the Siberian Traps exposed an enormous amount of fresh basalt and triggered CO2 release, rapid global warming, and acid rains, which in turn led to a rapid enhancement of continental weathering. The enhanced continental weathering delivered excessive nutrients to the oceans that could lead to marine eutrophication, anoxia, acidification, and ecological perturbation, ultimately resulting in the end-Permian mass extinction. PMID:29581278

Rapid enhancement of chemical weathering recorded by extremely light seawater lithium isotopes at the Permian-Triassic boundary

NASA Astrophysics Data System (ADS)

Sun, He; Xiao, Yilin; Gao, Yongjun; Zhang, Guijie; Casey, John F.; Shen, Yanan

2018-04-01

Lithium (Li) isotope analyses of sedimentary rocks from the Meishan section in South China reveal extremely light seawater Li isotopic signatures at the Permian–Triassic boundary (PTB), which coincide with the most severe mass extinction in the history of animal life. Using a dynamic seawater lithium box model, we show that the light seawater Li isotopic signatures can be best explained by a significant influx of riverine [Li] with light δ7Li to the ocean realm. The seawater Li isotope excursion started ≥300 Ky before and persisted up to the main extinction event, which is consistent with the eruption time of the Siberian Traps. The eruption of the Siberian Traps exposed an enormous amount of fresh basalt and triggered CO2 release, rapid global warming, and acid rains, which in turn led to a rapid enhancement of continental weathering. The enhanced continental weathering delivered excessive nutrients to the oceans that could lead to marine eutrophication, anoxia, acidification, and ecological perturbation, ultimately resulting in the end-Permian mass extinction.

Whole-Genome Sequencing of Native Sheep Provides Insights into Rapid Adaptations to Extreme Environments

PubMed Central

Yang, Ji; Li, Wen-Rong; Lv, Feng-Hua; He, San-Gang; Tian, Shi-Lin; Peng, Wei-Feng; Sun, Ya-Wei; Zhao, Yong-Xin; Tu, Xiao-Long; Zhang, Min; Xie, Xing-Long; Wang, Yu-Tao; Li, Jin-Quan; Liu, Yong-Gang; Shen, Zhi-Qiang; Wang, Feng; Liu, Guang-Jian; Lu, Hong-Feng; Kantanen, Juha; Han, Jian-Lin; Li, Meng-Hua; Liu, Ming-Jun

2016-01-01

Global climate change has a significant effect on extreme environments and a profound influence on species survival. However, little is known of the genome-wide pattern of livestock adaptations to extreme environments over a short time frame following domestication. Sheep (Ovis aries) have become well adapted to a diverse range of agroecological zones, including certain extreme environments (e.g., plateaus and deserts), during their post-domestication (approximately 8–9 kya) migration and differentiation. Here, we generated whole-genome sequences from 77 native sheep, with an average effective sequencing depth of ∼5× for 75 samples and ∼42× for 2 samples. Comparative genomic analyses among sheep in contrasting environments, that is, plateau (>4,000 m above sea level) versus lowland (<100 m), high-altitude region (>1500 m) versus low-altitude region (<1300 m), desert (<10 mm average annual precipitation) versus highly humid region (>600 mm), and arid zone (<400 mm) versus humid zone (>400 mm), detected a novel set of candidate genes as well as pathways and GO categories that are putatively associated with hypoxia responses at high altitudes and water reabsorption in arid environments. In addition, candidate genes and GO terms functionally related to energy metabolism and body size variations were identified. This study offers novel insights into rapid genomic adaptations to extreme environments in sheep and other animals, and provides a valuable resource for future research on livestock breeding in response to climate change. PMID:27401233

Comparative Testing of New Hemostatic Agents in a Swine Model of Extremity Arterial and Venous Hemorrhage

DTIC Science & Technology

2010-01-01

by the Institutional Animal Care and Use Committee and all animals received humane care in com- pliance with the Guide for the Care and Use of...diminished markedly in recent military operations, due to sev- eral factors including routine vi-ear of hody armor, judicious use of tourniquets for...extremity hemorrhage, rapid casualty evacuation, and aggressive use of blood products in hemor- rhagic shock.’’ Advanced hemostatic agents further reduce

Long-chain polyunsaturated fatty acids decline rapidly in milk from mothers delivering extremely preterm indicating the need for supplementation.

PubMed

Nilsson, Anders K; Löfqvist, Chatarina; Najm, Svetlana; Hellgren, Gunnel; Sävman, Karin; Andersson, Mats X; Smith, Lois E H; Hellström, Ann

2018-06-01

Our aim was to perform an in-depth analysis of the composition of fatty acids in milk from mothers delivering extremely preterm babies. We investigated longitudinal changes in milk fatty acid profiles and the relationship between several types of fatty acids, including omega-3 and omega-6. Milk samples were collected at three stages of lactation from 78 mothers who delivered at less than 28 weeks of pregnancy at the Sahlgrenska University Hospital, Gothenburg, Sweden, from April 2013 to September 2015. Fatty acid composition was analysed by gas chromatography-mass spectrometry. A reduction in long-chain polyunsaturated fatty acids (LCPUFAs) was observed during the lactation period. The concentrations of arachidonic acid and docosahexaenoic acid declined from medians of 0.34 to 0.22 mol% and 0.29 to 0.15 mol%, respectively, between postnatal day 7 and a postmenstrual age of 40 weeks. Strong correlations were found between the intermediates of several classes of fatty acids, including omega-3, omega-6 and omega-9. A rapid reduction in LCPUFA content in the mother's milk during the lactation period emphasises the importance of fatty acid supplementation to infants born extremely preterm, at least during the period corresponding to the third trimester, when rapid development of the brain and adipose tissue requires high levels of LCPUFAs. ©2018 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.

Scaling of precipitation extremes with temperature in the French Mediterranean region: What explains the hook shape?

NASA Astrophysics Data System (ADS)

Drobinski, P.; Alonzo, B.; Bastin, S.; Silva, N. Da; Muller, C.

2016-04-01

Expected changes to future extreme precipitation remain a key uncertainty associated with anthropogenic climate change. Extreme precipitation has been proposed to scale with the precipitable water content in the atmosphere. Assuming constant relative humidity, this implies an increase of precipitation extremes at a rate of about 7% °C-1 globally as indicated by the Clausius-Clapeyron relationship. Increases faster and slower than Clausius-Clapeyron have also been reported. In this work, we examine the scaling between precipitation extremes and temperature in the present climate using simulations and measurements from surface weather stations collected in the frame of the HyMeX and MED-CORDEX programs in Southern France. Of particular interest are departures from the Clausius-Clapeyron thermodynamic expectation, their spatial and temporal distribution, and their origin. Looking at the scaling of precipitation extreme with temperature, two regimes emerge which form a hook shape: one at low temperatures (cooler than around 15°C) with rates of increase close to the Clausius-Clapeyron rate and one at high temperatures (warmer than about 15°C) with sub-Clausius-Clapeyron rates and most often negative rates. On average, the region of focus does not seem to exhibit super Clausius-Clapeyron behavior except at some stations, in contrast to earlier studies. Many factors can contribute to departure from Clausius-Clapeyron scaling: time and spatial averaging, choice of scaling temperature (surface versus condensation level), and precipitation efficiency and vertical velocity in updrafts that are not necessarily constant with temperature. But most importantly, the dynamical contribution of orography to precipitation in the fall over this area during the so-called "Cevenoles" events, explains the hook shape of the scaling of precipitation extremes.

Carry-over fluency induced by extreme prolongations: A new behavioral paradigm.

PubMed

Briley, P M; Barnes, M P; Kalinowski, J S

2016-04-01

Extreme prolongations, which can be generated via extreme delayed auditory feedback (DAF) (e.g., 250-500 ms) or mediated cognitively with timing applications (e.g., analog stopwatch) at 2 s per syllable, have long been behavioral techniques used to inhibit stuttering. Some therapies have used this rate solely to establish initial fluency, while others use extremely slowed speech to establish fluency and add other strategic techniques such as easy onsets and diaphragmatic breathing. Extreme prolongations generate effective, efficient, and immediate forward flowing fluent speech, removing the signature behaviors of discrete stuttering (i.e., syllable repetitions and audible and inaudible postural fixations). Prolonged use of extreme prolongations establishes carry-over fluency, which is spontaneous, effortless speech absent of most, if not all, overt and covert manifestations of stuttering. The creation of this immediate fluency and the immense potential of extreme prolongations to generate long periods of carry-over fluency have been overlooked by researchers and clinicians alike. Clinicians depart from these longer prolongation durations as they attempt to achieve the same fluent results at a near normal rate of speech. Clinicians assume they are re-teaching fluency and slow rates will give rise to more normal rates with less control, but without carry-over fluency, controls and cognitive mediation are always needed for the inherently unstable speech systems of persons who stutter to experience fluent speech. The assumption being that the speech system is untenable without some level of cognitive and motoric monitoring that is always necessary. The goal is omnipresent "near normal rate sounding fluency" with continuous mediation via cognitive and motoric processes. This pursuit of "normal sounding fluency" continues despite ever-present relapse. Relapse has become so common that acceptance of stuttering is the new therapy modality because relapse has come to be understood as somewhat inevitable. Researchers and clinicians fail to recognize that immediate amelioration of stuttering and its attendant carry-over fluency are signs of a different pathway to fluency. In this path, clinicians focus on extreme prolongations and the extent of their carry-over. While fluency is automatically generated under these extreme prolongations, the realization is that communication at this rate in routine speaking tasks is not feasible. The perceived solution is a systematic reduction in the duration of these prolongations, which attempts to approximate "normal speech." Typically, the reintroduction of speech at a normalized rate precipitates a laborious style that is undesirable to the person who stutters (PWS) and is discontinued, once departed from the comforts of the clinical setting. The inevitable typically occurs; the well-intentioned therapist instructs the PWS to focus on the techniques while speaking at a rate that is nearest normal speech, but the overlooked extreme prolongations are unlikely to ever be revisited. The foundation of this hypothesis is that the departure from fluency generators (e.g. extreme prolongations) is the cause of regression to the stuttering set point. In turn, we postulate that the continued use of extreme prolongations, as a solitary practice method, will establish and nurture different neural pathways that will create a modality of fluent speech, able to be experienced without cognitive or motoric mediation. This would therefore result in fewer occurrences of stuttering due to a phenomenon called carry-over fluency. Thus, we hypothesize that the use of extreme prolongations fosters neural pathways for fluent speech, which will result in carry-over fluency that does not require mediation by the speaker. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physiotherapist agreement when visually rating movement quality during lower extremity functional screening tests.

PubMed

Whatman, Chris; Hing, Wayne; Hume, Patria

2012-05-01

To investigate physiotherapist agreement in rating movement quality during lower extremity functional tests using two visual rating methods and physiotherapists with differing clinical experience. Clinical measurement. Six healthy individuals were rated by 44 physiotherapists. These raters were in three groups (inexperienced, novice, experienced). Video recordings of all six individuals performing four lower extremity functional tests were visually rated (dichotomous or ordinal scale) using two rating methods (overall or segment) on two occasions separated by 3-4 weeks. Intra and inter-rater agreement for physiotherapists was determined using overall percentage agreement (OPA) and the first order agreement coefficient (AC1). Intra-rater agreement for overall and segment methods ranged from slight to almost perfect (OPA: 29-96%, AC1: 0.01 to 0.96). AC1 agreement was better in the experienced group (84-99% likelihood) and for dichotomous rating (97-100% likelihood). Inter-rater agreement ranged from fair to good (OPA: 45-79%; AC1: 0.22-0.71). AC1 agreement was not influenced by clinical experience but was again better using dichotomous rating. Physiotherapists' visual rating of movement quality during lower extremity functional tests resulted in slight to almost perfect intra-rater agreement and fair to good inter-rater agreement. Agreement improved with increased level of clinical experience and use of dichotomous rating. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Immediacy of Arctic Change

NASA Astrophysics Data System (ADS)

Overland, J. E.; Wang, M.; Soreide, N. N.

2015-12-01

Ongoing temperature changes in the Arctic are large relative to lower latitudes; a process known as Arctic Amplification. Arctic temperatures have increased at least 3 times the rate of mid-latitude temperatures relative to the late 20th century, due to multiple interacting feedbacks driven by modest global change. Even if global temperature increases are contained to +2° C by 2040, Arctic (North of 60° N) monthly mean temperatures in fall will increase by +5° C. The Arctic is very likely to be sea ice free during summer before 2040, with the sea ice free duration limited to <5 months. Snow cover will be absent in May and June on most land masses. Whether these changes impact mid-latitude weather events is complex and controversial, as the time period for observing such linkages is short [<10 years] and involves understanding direct forcing by Arctic changes on a chaotic climatic system. Although chaotic internal variability dominates the dynamics of atmospheric circulation, Arctic thermodynamic influences can reinforce regional weather patterns. Extreme Arctic temperature events, as a combination of mean temperature increases combined with natural variability, will become common, nearing and exceeding previous thresholds. Such an event as an analog for the future was the +4° C anomalies for Alaska in November-December 2014 related to recent warm Pacific sea surface temperatures. Thus for the next few decades out to 2040, continuing rapid environmental changes in the Arctic are very likely, despite any mitigation activities, and the appropriate response is to plan for adaptation to meet these mean and extreme event changes. Mitigation is essential to forestall further disasters in the second half of the century. It is important to note such future rapid Arctic amplification, and the potential for environmental surprises, to support those making planning decisions and encourage action.

Adaptation of the nematode Caenorhabditis elegans to extreme osmotic stress.

PubMed

Lamitina, S Todd; Morrison, Rebecca; Moeckel, Gilbert W; Strange, Kevin

2004-04-01

The ability to control osmotic balance is essential for cellular life. Cellular osmotic homeostasis is maintained by accumulation and loss of inorganic ions and organic osmolytes. Although osmoregulation has been studied extensively in many cell types, major gaps exist in our molecular understanding of this essential process. Because of its numerous experimental advantages, the nematode Caenorhabditis elegans provides a powerful model system to characterize the genetic basis of animal cell osmoregulation. We therefore characterized the ability of worms to adapt to extreme osmotic stress. Exposure of worms to high-salt growth agar causes rapid shrinkage. Survival is normal on agar containing up to 200 mM NaCl. When grown on 200 mM NaCl for 2 wk, worms are able to survive well on agar containing up to 500 mM NaCl. HPLC analysis demonstrated that levels of the organic osmolyte glycerol increase 15- to 20-fold in nematodes grown on 200 mM NaCl agar. Accumulation of glycerol begins 3 h after exposure to hypertonic stress and peaks by 24 h. Glycerol accumulation is mediated primarily by synthesis from metabolic precursors. Consistent with this finding, hypertonicity increases transcriptional expression of glycerol 3-phosphate dehydrogenase, an enzyme that is rate limiting for hypertonicity-induced glycerol synthesis in yeast. Worms adapted to high salt swell and then return to their initial body volume when exposed to low-salt agar. During recovery from hypertonic stress, glycerol levels fall rapidly and glycerol excretion increases approximately fivefold. Our studies provide the first description of osmotic adaptation in C. elegans and provide the foundation for genetic and functional genomic analysis of animal cell osmoregulation.

The remarkable outburst of the highly evolved post-period-minimum dwarf nova SSS J122221.7-311525★

NASA Astrophysics Data System (ADS)

Neustroev, V. V.; Marsh, T. R.; Zharikov, S. V.; Knigge, C.; Kuulkers, E.; Osborne, J. P.; Page, K. L.; Steeghs, D.; Suleimanov, V. F.; Tovmassian, G.; Breedt, E.; Frebel, A.; García-Díaz, Ma. T.; Hambsch, F.-J.; Jacobson, H.; Parsons, S. G.; Ryu, T.; Sabin, L.; Sjoberg, G.; Miroshnichenko, A. S.; Reichart, D. E.; Haislip, J. B.; Ivarsen, K. M.; LaCluyze, A. P.; Moore, J. P.

2017-05-01

We report extensive 3-yr multiwavelength observations of the WZ Sge-type dwarf nova SSS J122221.7-311525 during its unusual double superoutburst, the following decline and in quiescence. The second segment of the superoutburst had a long duration of 33 d and a very gentle decline with a rate of 0.02 mag d-1, and it displayed an extended post-outburst decline lasting at least 500 d. Simultaneously with the start of the rapid fading from the superoutburst plateau, the system showed the appearance of a strong near-infrared excess resulting in very red colours, which reached extreme values (B - I ≃ 1.4) about 20 d later. The colours then became bluer again, but it took at least 250 d to acquire a stable level. Superhumps were clearly visible in the light curve from our very first time-resolved observations until at least 420 d after the rapid fading from the superoutburst. The spectroscopic and photometric data revealed an orbital period of 109.80 min and a fractional superhump period excess ≲0.8 per cent, indicating a very low mass ratio q ≲ 0.045. With such a small mass ratio the donor mass should be below the hydrogen-burning minimum mass limit. The observed infrared flux in quiescence is indeed much lower than is expected from a cataclysmic variable with a near-main-sequence donor star. This strongly suggests a brown-dwarf-like nature for the donor and that SSS J122221.7-311525 has already evolved away from the period minimum towards longer periods, with the donor now extremely dim.

Filamentous Morphology as a Means for Thermophilic Bacteria to Survive Steep Physical and Chemical Gradients in Yellowstone Hot Springs

NASA Astrophysics Data System (ADS)

Dong, Y.; Srivastava, V.; Bulone, V.; Keating, K. M.; Khetani, R. S.; Fields, C. J.; Inskeep, W.; Sanford, R. A.; Yau, P. M.; Imai, B. S.; Hernandez, A. G.; Wright, C.; Band, M.; Cann, I. K.; Ahrén, D.; Fouke, K. W.; Sivaguru, M.; Fried, G.; Fouke, B. W.

2017-12-01

The filamentous heat-loving bacterium Sulfurihydrogenibium yellowstonense makes up more than 90% of the microbial community that inhabits turbulent, dysoxic hot spring outflow channels (66-71°C, 6.2-6.5 pH, 0.5-0.75 m/s flow rate) at Mammoth Hot Spring in Yellowstone National Park. These environments contain abundantly available inorganic substrates (e.g., CO2, sulfide and thiosulfate) and are associated with extensive CaCO3 (travertine) precipitation driven in part by CO2 off-gassing. Evidence from integrated Meta-Omics analyses of DNA, RNA, and proteins (metagenomics, metatranscriptomics and metaproteomics) extracted from these S. yellowstonense-dominated communities have detected 1499 non-rRNA open reading frames (ORFs), their transcripts and cognate proteins. During chemoautotrophy and CO2 carbon fixation, chaperons facilitate enzymatic stability and functionalities under elevated temperature. High abundance transcripts and proteins for Type IV pili and exopolysaccharides (EPS) are consistent with S. yellowstonense forming strong (up to 0.5 m) intertwined microbial filaments (fettuccini streamers) composed of linked individual cells that withstand hydrodynamic shear forces and extremely rapid travertine mineralization. Their primary energy source is the oxidation of reduced sulfur (e.g., sulphide, sulfur or thiosulfate) and the simultaneous uptake of extremely low concentrations of dissolved O2 facilitated by bd-type cytochromes. Field observations indicate that the fettuccini microbial filaments build up ridged travertine platforms on the bottom of the springs, parallel to the water flow, where living filaments attach almost exclusively to the top of each ridge. This maximizes their access to miniscule amounts of dissolved oxygen, while optimizing their ability to rapidly form down-flow branched filaments and thus survive in these stressful environments that few other microbes can inhabit.

Intraoperative fluorescence angiography: a review of applications and outcomes in war-related trauma.

PubMed

Green, J Marshall; Sabino, Jennifer; Fleming, Mark; Valerio, Ian

2015-03-01

In the recent Iraq and Afghanistan conflicts, survival rates from complex battlefield injuries have continued to improve. The resulting war-related wounds are challenging, with confounding issues making assessment of tissue perfusion subjective and variable. This review discusses the utility of intraoperative fluorescence angiography, and its usefulness as an objective tool to evaluate the perfusion of tissues in the face of complex war-related injuries. A retrospective review of all war-related traumatic and reconstructive cases employing intraoperative indocyanine green laser angiography (ICGLA) was performed. Data analyzed included indication for use, procedure success/failure rates, modifications performed, and perfusion-related complications. Anatomical regions assessed were extremity, head and neck, truncal, and intra-abdominal viscera. The endpoint of specific interest involved the decision for additional debridement of poorly perfused tissue, as based on the ICGLA findings. Over a 3-year period, this study examined 123 extremity soft tissue flaps, 41 extremity injuries including amputation and/or amputation revision cases, 13 craniofacial flaps, and 9 truncal/abdomen/gastrointestinal cases in which ICGLA was utilized to assess tissue perfusion and viability. A total of 35 (18.8%) of cases employing ICGLA required intraoperative modifications to address perfusion-related issues. Intraoperative fluorescent angiography is an objective, useful tool to assess various war-related traumatic injuries. This study expands on prior cited indications for ICGLA to include (1) guiding debridement in heavily contaminated wounds, (2) providing improved assessment of avulsion soft tissue injuries, (3) allowing for rapid detection of vascular and/or microvascular compromise in soft tissue and osseous flap reconstructions, (4) reducing and preventing perfusion-related complications in trauma, amputation closures, and reconstruction procedures, (5) contributing to better outcomes in certain complex orthopedic and composite tissue injuries, and (6) enabling improved postoperative wound and reconstruction assessment in those cases of perfusion-related issues that arise within a delayed setting. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

Extreme Precipitation and Emergency Room Visits for Gastrointestinal Illness in Areas with and without Combined Sewer Systems: An Analysis of Massachusetts Data, 2003-2007.

PubMed

Jagai, Jyotsna S; Li, Quanlin; Wang, Shiliang; Messier, Kyle P; Wade, Timothy J; Hilborn, Elizabeth D

2015-09-01

Combined sewer overflows (CSOs) occur in combined sewer systems when sewage and stormwater runoff are released into water bodies, potentially contaminating water sources. CSOs are often caused by heavy precipitation and are expected to increase with increasing extreme precipitation associated with climate change. The aim of this study was to assess whether the association between heavy rainfall and rate of emergency room (ER) visits for gastrointestinal (GI) illness differed in the presence of CSOs. For the study period 2003-2007, time series of daily rate of ER visits for GI illness and meteorological data were organized for three exposure regions: a) CSOs impacting drinking water sources, b) CSOs impacting recreational waters, c) no CSOs. A distributed lag Poisson regression assessed cumulative effects for an 8-day lag period following heavy (≥ 90th and ≥ 95th percentile) and extreme (≥ 99th percentile) precipitation events, controlling for temperature and long-term time trends. The association between extreme rainfall and rate of ER visits for GI illness differed among regions. Only the region with drinking water exposed to CSOs demonstrated a significant increased cumulative risk for rate (CRR) of ER visits for GI for all ages in the 8-day period following extreme rainfall: CRR: 1.13 (95% CI: 1.00, 1.28) compared with no rainfall. The rate of ER visits for GI illness was associated with extreme precipitation in the area with CSO discharges to a drinking water source. Our findings suggest an increased risk for GI illness among consumers whose drinking water source may be impacted by CSOs after extreme precipitation. Jagai JS, Li Q, Wang S, Messier KP, Wade TJ, Hilborn ED. 2015. Extreme precipitation and emergency room visits for gastrointestinal illness in areas with and without combined sewer systems: an analysis of Massachusetts data, 2003-2007. Environ Health Perspect 123:873-879; http://dx.doi.org/10.1289/ehp.1408971.

Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control

PubMed Central

Conan, Anne; Akerele, Oluyemisi; Simpson, Greg; Reininghaus, Bjorn; van Rooyen, Jacques; Knobel, Darryn

2015-01-01

Background Rabies is a serious yet neglected public health threat in resource-limited communities in Africa, where the virus is maintained in populations of owned, free-roaming domestic dogs. Rabies elimination can be achieved through the mass vaccination of dogs, but maintaining the critical threshold of vaccination coverage for herd immunity in these populations is hampered by their rapid turnover. Knowledge of the population dynamics of free-roaming dog populations can inform effective planning and implementation of mass dog vaccination campaigns to control rabies. Methodology/Principal Findings We implemented a health and demographic surveillance system in dogs that monitored the entire owned dog population within a defined geographic area in a community in Mpumalanga Province, South Africa. We quantified demographic rates over a 24-month period, from 1st January 2012 through 1st January 2014, and assessed their implications for rabies control by simulating the decline in vaccination coverage over time. During this period, the population declined by 10%. Annual population growth rates were +18.6% in 2012 and -24.5% in 2013. Crude annual birth rates (per 1,000 dog-years of observation) were 451 in 2012 and 313 in 2013. Crude annual death rates were 406 in 2012 and 568 in 2013. Females suffered a significantly higher mortality rate in 2013 than males (mortality rate ratio [MRR] = 1.54, 95% CI = 1.28–1.85). In the age class 0–3 months, the mortality rate of dogs vaccinated against rabies was significantly lower than that of unvaccinated dogs (2012: MRR = 0.11, 95% CI = 0.05–0.21; 2013: MRR = 0.31, 95% CI = 0.11–0.69). The results of the simulation showed that achieving a 70% vaccination coverage during annual campaigns would maintain coverage above the critical threshold for at least 12 months. Conclusions and Significance Our findings provide an evidence base for the World Health Organization’s empirically-derived target of 70% vaccination coverage during annual campaigns. Achieving this will be effective even in highly dynamic populations with extremely high growth rates and rapid turnover. This increases confidence in the feasibility of dog rabies elimination in Africa through mass vaccination. PMID:26545242

Coupling of methylmercury uptake with respiration and water pumping in freshwater tilapia Oreochromis niloticus.

PubMed

Wang, Rui; Wong, Ming-Hung; Wang, Wen-Xiong

2011-09-01

The relationships among the uptake of toxic methylmercury (MeHg) and two important fish physiological processes-respiration and water pumping--in the Nile tilapia (Oreochromis niloticus) were explored in the present study. Coupled radiotracer and respirometric techniques were applied to measure simultaneously the uptake rates of MeHg, water, and oxygen under various environmental conditions (temperature, dissolved oxygen level, and water flow). A higher temperature enhanced MeHg influx and the oxygen consumption rate but had no effect on the water uptake, indicating the influence of metabolism on MeHg uptake. The fish showed a high tolerance to hypoxia, and the oxygen consumption rate was not affected until the dissolved oxygen concentration decreased to extremely low levels (below 1 mg/L). The MeHg and water uptake rates increased simultaneously as the dissolved oxygen level decreased, suggesting the coupling of water flux and MeHg uptake. The influence of fish swimming performance on MeHg uptake was also investigated for the first time. Rapidly swimming fish showed significantly higher uptake rates of MeHg, water, and oxygen, confirming the coupling relationships among respiration, water pumping, and metal uptake. Moreover, these results support that MeHg uptake is a rate-limiting process involving energy. Our study demonstrates the importance of physiological processes in understanding mercury bioaccumulation in fluctuating aquatic environments. Copyright © 2011 SETAC.

Improving simulated long-term responses of vegetation to temperature and precipitation extremes using the ACME land model

NASA Astrophysics Data System (ADS)

Ricciuto, D. M.; Warren, J.; Guha, A.

2017-12-01

While carbon and energy fluxes in current Earth system models generally have reasonable instantaneous responses to extreme temperature and precipitation events, they often do not adequately represent the long-term impacts of these events. For example, simulated net primary productivity (NPP) may decrease during an extreme heat wave or drought, but may recover rapidly to pre-event levels following the conclusion of the extreme event. However, field measurements indicate that long-lasting damage to leaves and other plant components often occur, potentially affecting the carbon and energy balance for months after the extreme event. The duration and frequency of such extreme conditions is likely to shift in the future, and therefore it is critical for Earth system models to better represent these processes for more accurate predictions of future vegetation productivity and land-atmosphere feedbacks. Here we modify the structure of the Accelerated Climate Model for Energy (ACME) land surface model to represent long-term impacts and test the improved model against observations from experiments that applied extreme conditions in growth chambers. Additionally, we test the model against eddy covariance measurements that followed extreme conditions at selected locations in North America, and against satellite-measured vegetation indices following regional extreme events.

Extreme events assessment methodology coupling rainfall and tidal levels in the coastal floodplain of the São Paulo North Coast (Brazil) for drainage purposes

NASA Astrophysics Data System (ADS)

Alfredini, P.; Cartacho, D. L.; Arasaki, E.; Rosso, M.; Sousa, W. C., Jr.; Lanzieri, D. R.; Ferreira, J. P. M.

2012-04-01

The Caraguatatuba Coastal Plain is the wider in São Paulo State (Brazil) North Coastline. The Santo Antônio Torrent Catchmenth drains that region with high urban concentration (around 100,000 permanent inhabitants), which may quintuplicate with the turists in the summer period. In the last decade important oil and gas sea reserves were discovered and the facilities for their treatment were located in that region. For that great economic growth scenario it is mandatory to design mitigation risk measures to have the fluvial forcing processes well known, considering the natural hazards. The Santo Antônio catchment has a surface area of 40 km2, heavy rainfall rates (around 3000 mm/year), concentrated mainly in the summer period, producing high fluvial sediment transport capacity, floods and debris-flows. Due to the steep slopes and the altitude (~ 1000 m) of the mountains near the coast, the hydrological orographic effect rapidly condensates the sea humidity and recurrent and intense flood events cause extensive risks and damages to population and infrastructures. Strong debris-flows occur in that region, because rains higher than 300-400 mm per day occur in multi decadal periods. Due to the wind blowing landward the humidity from the sea, also meteorological tides occur in correspondence of high rainfall rates. The aim of this project is to present an extreme hydrological assessment methodology, coupling rainfall rates and tidal levels, to show the impact of climate changes during the last decades. It is also presented the magnitude of the rising meteorological tide coupled with the extreme rainfall events. The data base analysed comprised long term data of rainfall and tidal measurements from 1954 to 2003. The correlations of the two data were divided in five classes of rainfall in mm per day (> 0, > 25, > 50, > 75 and > 100) and estimated the tidal levels for different return periods in years (2, 5, 10, 20, 50, 75 and 100). The comparison of two distint periods (1954 to 1980 and 1981 to 2000) for extreme events typically used for drainage projects (rains higher than 50 mm/day) clearly showed an increasing in tidal levels for the same return period. That trend indicates the importance to mantain a monitoring network in order to avoid the interruption of long term data series. According to that conclusions were evaluated the number of constructions and inhabitants affected in the are prone of that flooding in the next decades.

Patterns of gun deaths across US counties 1999-2013.

PubMed

Kalesan, Bindu; Galea, Sandro

2017-05-01

We examined the socio-demographic distribution of gun deaths across 3143 counties in 50 United States' states to understand the spatial patterns and correlates of high and low gun deaths. We used aggregate counts of gun deaths and population in all counties from 1999 to 2013 from the Centers for Disease Control and Prevention's Wide-ranging Online Data for Epidemiologic Research (WONDER). We characterized four levels of gun violence, as distinct levels of gun death rates of relatively safe, unsafe, violent, and extremely violent counties, based on quartiles of 15-year county-specific gun death rates per 100,000 and used negative binomial regression models allowing clustering by state to calculate incidence rate ratios and 95% confidence intervals (95% CIs). Most states had at least one violent or extremely violent county. Extremely violent gun counties were mostly rural, poor, predominantly minority, had high unemployment rate and homicide rate. Overall, homicide rate was significantly associated with gun deaths (incidence rate ratios = 1.08, 95% CI = 1.06-1.09). In relatively safe counties, this risk was 1.09 (95% CI = 1.05-1.13) and in extremely violent gun counties was 1.03 (95% CI = 1.03-1.04). There are broad differences in gun death rates across the United States representing different levels of gun death rates in each state with distinct socio-demographic profiles. Copyright © 2017 Elsevier Inc. All rights reserved.

Relationships of consumer sensory ratings, marbling score, and shear force value to consumer acceptance of beef strip loin steaks.

PubMed

Platter, W J; Tatum, J D; Belk, K E; Chapman, P L; Scanga, J A; Smith, G C

2003-11-01

Logistic regression was used to quantify and characterize the effects of changes in marbling score, Warner-Bratzler shear force (WBSF), and consumer panel sensory ratings for tenderness, juiciness, or flavor on the probability of overall consumer acceptance of strip loin steaks from beef carcasses (n = 550). Consumers (n = 489) evaluated steaks for tenderness, juiciness, and flavor using nine-point hedonic scales (1 = like extremely and 9 = dislike extremely) and for overall steak acceptance (satisfied or not satisfied). Predicted acceptance of steaks by consumers was high (> 85%) when the mean consumer sensory rating for tenderness,juiciness, or flavor for a steak was 3 or lower on the hedonic scale. Conversely, predicted consumer acceptance of steaks was low (< or = 10%) when the mean consumer rating for tenderness, juiciness, or flavor for a steak was 5 or higher on the hedonic scale. As mean consumer sensory ratings for tenderness, juiciness, or flavor decreased from 3 to 5, the probability of acceptance of steaks by consumers diminished rapidly in a linear fashion. These results suggest that small changes in consumer sensory ratings for these sensory traits have dramatic effects on the probability of acceptance of steaks by consumers. Marbling score displayed a weak (adjusted R2 = 0.053), yet significant (P < 0.01), relationship to acceptance of steaks by consumers, and the shape of the predicted probability curve for steak acceptance was approximately linear over the entire range of marbling scores (Traces67 to Slightly Abundant97), suggesting that the likelihood of consumer acceptance of steaks increases approximately 10% for each full marbling score increase between Slight to Slightly Abundant. The predicted probability curve for consumer acceptance of steaks was sigmoidal for the WBSF model, with a steep decline in predicted probability of acceptance as WBSF values increased from 3.0 to 5.5 kg. Changes in WBSF within the high (> 5.5 kg) or low (< 3.0 kg) portions of the range of WBSF values had little effect on the probability of consumer acceptance of steaks.

Decadal-scale variation in dune erosion and accretion rates: An investigation of the significance of changing storm tide frequency and magnitude on the Sefton coast, UK

NASA Astrophysics Data System (ADS)

Pye, K.; Blott, S. J.

2008-12-01

Monitoring of frontal dune erosion and accretion on the Sefton coast in northwest England over the past 50 years has revealed significant spatial and temporal variations. Previous work has shown that the spatial variations primarily reflect longshore differences in beach and nearshore morphology, energy regime and sediment budget, but the causes of temporal variations have not previously been studied in detail. This paper presents the results of work carried out to test the hypothesis that a major cause of temporal variation is changes in the frequency and magnitude of storms, surges and resulting high tides. Dune toe erosion/accretion records dating from 1958 have been compared with tide gauge records at Liverpool and Heysham. Relatively high dune erosion rates at Formby Point 1958-1968 were associated with a relatively large number of storm tides. Slower erosion at Formby, and relatively rapid accretion in areas to the north and south, occurred during the 1970's and 1980's when there were relatively few major storm tides. After 1990 rates of dune erosion at Formby increased again, and dunes to the north and south experienced slower accretion. During this period high storm tides have been more frequent, and the annual number of hours with water levels above the critical level for dune erosion has increased significantly. An increase in the rate of mean sea-level rise at both Liverpool and Heysham is evident since 1990, but we conclude that this factor is of less importance than the occurrence of extreme high tides and wave action associated with storms. The incidence of extreme high tides shows an identifiable relationship with the lunar nodal tidal cycle, but the evidence indicates that meteorological forcing has also had a significant effect. Storms and surges in the eastern Irish Sea are associated with Atlantic depressions whose direction and rate of movement have a strong influence on wind speeds, wave energy and the height of surge tides. However, preliminary analysis has indicated only a modest relationship between dune erosion/accretion rates and the North Atlantic Oscillation index.

Effect of the stellar spin history on the tidal evolution of close-in planets

NASA Astrophysics Data System (ADS)

Bolmont, E.; Raymond, S. N.; Leconte, J.; Matt, S. P.

2012-08-01

Context. The spin rate of stars evolves substantially during their lifetime, owing to the evolution of their internal structure and to external torques arising from the interaction of stars with their environments and stellar winds. Aims: We investigate how the evolution of the stellar spin rate affects, and is affected by, planets in close orbits via star-planet tidal interactions. Methods: We used a standard equilibrium tidal model to compute the orbital evolution of single planets orbiting both Sun-like stars and very low-mass stars (0.1 M⊙). We tested two stellar spin evolution profiles, one with fast initial rotation (1.2 day rotation period) and one with slow initial rotation (8 day period). We tested the effect of varying the stellar and planetary dissipations, and the planet's mass and initial orbital radius. Results: For Sun-like stars, the different tidal evolution between initially rapidly and slowly rotating stars is only evident for extremely close-in gas giants orbiting highly dissipative stars. However, for very low-mass stars the effect of the initial rotation of the star on the planet's evolution is apparent for less massive (1 M⊕) planets and typical dissipation values. We also find that planetary evolution can have significant effects on the stellar spin history. In particular, when a planet falls onto the star, it can cause the star to spin up. Conclusions: Tidal evolution allows us to differentiate between the early behaviors of extremely close-in planets orbiting either a rapidly rotating star or a slowly rotating star. The early spin-up of the star allows the close-in planets around fast rotators to survive the early evolution. For planets around M-dwarfs, surviving the early evolution means surviving on Gyr timescales, whereas for Sun-like stars the spin-down brings about late mergers of Jupiter planets. In the light of this study, we can say that differentiating one type of spin evolution from another given the present position of planets can be very tricky. Unless we can observe some markers of former evolution, it is nearly impossible to distinguish the two very different spin profiles, let alone intermediate spin-profiles. Nevertheless, some conclusions can still be drawn about statistical distributions of planets around fully convective M-dwarfs. If tidal evolution brings about a merger late in the stellar history, it can also entail a noticeable acceleration of the star at late ages, so that it is possible to have old stars that spin rapidly. This raises the question of how the age of stars can be more tightly constrained.

The Engineering for Climate Extremes Partnership

NASA Astrophysics Data System (ADS)

Holland, G. J.; Tye, M. R.

2014-12-01

Hurricane Sandy and the recent floods in Thailand have demonstrated not only how sensitive the urban environment is to the impact of severe weather, but also the associated global reach of the ramifications. These, together with other growing extreme weather impacts and the increasing interdependence of global commercial activities point towards a growing vulnerability to weather and climate extremes. The Engineering for Climate Extremes Partnership brings academia, industry and government together with the goals encouraging joint activities aimed at developing new, robust, and well-communicated responses to this increasing vulnerability. Integral to the approach is the concept of 'graceful failure' in which flexible designs are adopted that protect against failure by combining engineering or network strengths with a plan for efficient and rapid recovery if and when they fail. Such an approach enables optimal planning for both known future scenarios and their assessed uncertainty.

Tissue Adhesives for Battlefield Hemorrhage Control

DTIC Science & Technology

1996-04-01

extremely high bioburden it is felt that a rapid elution of the CHX or antimicrobial could be advantages. It is this rapid dumping of the 8000 Mw film...absorbance of each test article solution was determined spectrophotometrically at 545 nm. Similarly, absorbances were recorded for the positive...used to calculate percent hemolysis for the test article . Results showed 0.0% hemolysis for both test #1 and test #2, with a mean hemolysis of 0.0

Back and upper extremity disorders among enlisted U.S. Marines: burden and individual risk factors.

PubMed

Huang, G D; Feuerstein, M; Arroyo, F

2001-11-01

Although musculoskeletal disorders of the low back and upper extremities can affect military readiness, little is known about their extent and risk factors in the U.S. Marine Corps. Using the Defense Medical Epidemiology and Defense Medical Surveillance System databases, back and upper extremity diagnostic categories were among the top four sources of outpatient visits and duty limitation among enlisted Marines. Back disorders were also found to be the fifth most common cause for lost time. Subsequently, high-risk occupations were identified, age-related trends for clinic visit rates were determined, and rate ratios were computed for the top 15 low back and upper extremity diagnoses among enlisted Marines from 1997 through 1998. Occupational categories with the highest rates of musculoskeletal-related outpatient visits included image interpretation, auditing and accounting, disturbsing, surveillance/target acquisition, and aircraft launch equipment. Significantly increasing linear trends in rates across age groups were found for most diagnoses. For 1998, age-specific rate ratios indicated significantly higher rates for most low back and upper extremity disorders for females; lower rank (i.e., E1-E4) was also a risk, but for fewer diagnoses. The findings emphasize the need to identify modifiable (e.g., work-related, individual) risk factors and to develop focused primary and secondary prevention programs for musculoskeletal disorders in the Marine Corps. Subsequently, these efforts can assist in reducing associated effects, maximizing resource utilization, and enhancing operational readiness.

Neuron-Inspired Fe3O4/Conductive Carbon Filament Network for High-Speed and Stable Lithium Storage.

PubMed

Hao, Shu-Meng; Li, Qian-Jie; Qu, Jin; An, Fei; Zhang, Yu-Jiao; Yu, Zhong-Zhen

2018-05-17

Construction of a continuous conductance network with high electron-transfer rate is extremely important for high-performance energy storage. Owing to the highly efficient mass transport and information transmission, neurons are exactly a perfect model for electron transport, inspiring us to design a neuron-like reaction network for high-performance lithium-ion batteries (LIBs) with Fe 3 O 4 as an example. The reactive cores (Fe 3 O 4 ) are protected by carbon shells and linked by carbon filaments, constituting an integrated conductance network. Thus, once the reaction starts, the electrons released from every Fe 3 O 4 cores are capable of being transferred rapidly through the whole network directly to the external circuit, endowing the nanocomposite with tremendous rate performance and ultralong cycle life. After 1000 cycles at current densities as high as 1 and 2 A g -1 , charge capacities of the as-synthesized nanocomposite maintain 971 and 715 mA h g -1 , respectively, much higher than those of reported Fe 3 O 4 -based anode materials. The Fe 3 O 4 -based conductive network provides a new idea for future developments of high-rate-performance LIBs.

Blue-light digital communication in underwater environments utilizing orbital angular momentum

NASA Astrophysics Data System (ADS)

Baghdady, Joshua; Miller, Keith; Osler, Sean; Morgan, Kaitlyn; Li, Wenzhe; Johnson, Eric; Cochenour, Brandon

2016-05-01

Underwater optical communication has recently become the topic of much investigation as the demands for underwater data transmission have rapidly grown in recent years. The need for reliable, high-speed, secure underwater communication has turned increasingly to blue-light optical solutions. The blue-green visible wavelength window provides an attractive solution to the problem of underwater data transmission thanks to its low attenuation, where traditional RF solutions used in free-space communications collapse. Beginning with GaN laser diodes as the optical source, this work explores the encoding and transmission of digital data across underwater environments of varying turbidities. Given the challenges present in an underwater environment, such as the mechanical and optical turbulences that make proper alignment difficult to maintain, it is desirable to achieve extremely high data rates in order to allow the time window of alignment between the transmitter and receiver to be as small as possible. In this paper, work is done to increase underwater data rates through the use of orbital angular momentum. Results are shown for a range of data rates across a variety of channel types ranging in turbidity from that of a clear ocean to a dirty harbor.

The modulation rate transfer function of a harbour porpoise (Phocoena phocoena).

PubMed

Linnenschmidt, Meike; Wahlberg, Magnus; Damsgaard Hansen, Janni

2013-02-01

During echolocation, toothed whales produce ultrasonic clicks at extremely rapid rates and listen for the returning echoes. The auditory brainstem response (ABR) duration was evaluated in terms of latency between single peaks: 5.5 ms (from peak I to VII), 3.4 ms (I-VI), and 1.4 ms (II-IV). In comparison to the killer whale and the bottlenose dolphin, the ABR of the harbour porpoise has shorter intervals between the peaks and consequently a shorter ABR duration. This indicates that the ABR duration and peak latencies are possibly related to the relative size of the auditory structures of the central nervous system and thus to the animal's size. The ABR to a sinusoidal amplitude modulated stimulus at 125 kHz (sensitivity threshold 63 dB re 1 μPa rms) was evaluated to determine the modulation rate transfer function of a harbour porpoise. The ABR showed distinct envelope following responses up to a modulation rate of 1,900 Hz. The corresponding calculated equivalent rectangular duration of 263 μs indicates a good temporal resolution in the harbour porpoise auditory system similar to the one for the bottlenose dolphin. The results explain how the harbour porpoise can follow clicks and echoes during echolocation with very short inter click intervals.

The Effect of Elevated CO2 and Temperature on the Hatch Rate and Survival of Estuarine Forage Fish

NASA Astrophysics Data System (ADS)

Merlo, L. R.; Gobler, C.

2016-02-01

The World Oceans are acidifying and warming, yet little is known regarding how these processes will combine to impact fish populations. In estuaries, microbial respiration of eutrophication-enhanced organic matter can create elevated CO2 levels during late spring and summer seasons when thermal extremes can occur and temperate fish spawn. Here, we report on experiments that exposed fish embryos (e.g. Menidia beryllina, inland silverside) to normal and elevated CO2 (400 and 2,000 ppm) and the range of temperatures experienced within temperate estuaries during the spawning season (16 - 30C). Fish survival and growth rates were quantified from hatching through early life, larval stages. Temperature controlled egg hatching times, with elevated temperatures leading to more rapid hatch rates. Elevated levels of CO2 significantly depressed post-hatch survival of fish. Survival rates of fish exposed to elevated CO2 at lower than ideal temperatures were significantly lower than predicted by either variable individually indicating the ability of these stressors to synergistically interact. Since embryonic stages have been identified as being highly sensitive to acidification, this finding may be associated with the extended exposure of eggs to high CO2 at lower temperatures. The physiological mechanisms driving experimental trends and broader ecological implications of the study will be discussed.

Regional warming of hot extremes accelerated by surface energy fluxes consistent with drying soils

NASA Astrophysics Data System (ADS)

Donat, M.; Pitman, A.; Seneviratne, S. I.

2017-12-01

Strong regional differences exist in how hot temperature extremes increase under global warming. Using an ensemble of coupled climate models, we examine the regional warming rates of hot extremes relative to annual average warming rates in the same regions. We identify hotspots of accelerated warming of model-simulated hot extremes in Europe, North America, South America and Southeast China. These hotspots indicate where the warm tail of a distribution of temperatures increases faster than the average and are robust across most CMIP5 models. Exploring the conditions on the specific day the hot extreme occurs demonstrates the hotspots are explained by changes in the surface energy fluxes consistent with drying soils. Furthermore, in these hotspot regions we find a relationship between the temperature - heat flux correlation under current climate conditions and the magnitude of future projected changes in hot extremes, pointing to a potential emergent constraint for simulations of future hot extremes. However, the model-simulated accelerated warming of hot extremes appears inconsistent with observations of the past 60 years, except over Europe. The simulated acceleration of hot extremes may therefore be unreliable, a result that necessitates a re-evaluation of how climate models resolve the relevant terrestrial processes.

Resilience and Suicidality among Homeless Youth

ERIC Educational Resources Information Center

Cleverley, Kristin; Kidd, Sean A.

2011-01-01

Homeless and street-involved youth are considered an extremely high risk group, with many studies highlighting trajectories characterized by abusive, neglectful, and unstable family histories, victimization and criminal involvement while on the streets, high rates of physical and mental illness, and extremely high rates of mortality. While there…

Australian climate extremes at 1.5 °C and 2 °C of global warming

NASA Astrophysics Data System (ADS)

King, Andrew D.; Karoly, David J.; Henley, Benjamin J.

2017-06-01

To avoid more severe impacts from climate change, there is international agreement to strive to limit warming to below 1.5 °C. However, there is a lack of literature assessing climate change at 1.5 °C and the potential benefits in terms of reduced frequency of extreme events. Here, we demonstrate that existing model simulations provide a basis for rapid and rigorous analysis of the effects of different levels of warming on large-scale climate extremes, using Australia as a case study. We show that limiting warming to 1.5 °C, relative to 2 °C, would perceptibly reduce the frequency of extreme heat events in Australia. The Australian continent experiences a variety of high-impact climate extremes that result in loss of life, and economic and environmental damage. Events similar to the record-hot summer of 2012-2013 and warm seas associated with bleaching of the Great Barrier Reef in 2016 would be substantially less likely, by about 25% in both cases, if warming is kept to lower levels. The benefits of limiting warming on hydrometeorological extremes are less clear. This study provides a framework for analysing climate extremes at 1.5 °C global warming.

Basic Instincts.

ERIC Educational Resources Information Center

Simpson, Liz

2003-01-01

Two kinds of knowing are the slow, rational, analytic kind that comes from deliberate reasoning and the rapid, seemingly effortless, emotionally based intuitive kind. Intuition is an information processing style that can be extremely helpful as an adjunct to logical knowledge. (Author/JOW)

Rapid onset aggressive vertebral haemangioma.

PubMed

Cheung, Nicholas K; Doorenbosch, Xenia; Christie, John G

2011-03-01

Vertebral haemangiomas are generally benign asymptomatic vascular tumours seen commonly in the adult population. Presentations in paediatric populations are extremely rare, which can result in rapid onset of neurological symptoms. We present a highly unusual case of an aggressive paediatric vertebral haemangioma causing significant cord compression. A 13-year-old boy presented with only 2 weeks duration of progressive gait disturbance, truncal ataxia and loss of bladder control. Magnetic resonance imaging (MRI) of the spine revealed a large vascular epidural mass extending between T6 and T8 vertebral bodies. Associated displacement and compression of the spinal cord was present. A highly vascular bony lesion was found during surgery. Histopathology identified this tumour to be a vertebral haemangioma. We present an extremely unusual acute presentation of a paediatric vertebral haemangioma. This study highlights the need for early diagnosis, MRI for investigation and urgent surgical management. © Springer-Verlag 2011

A rapid fish radiation associated with the last sea-level changes in southern Brazil: the silverside Odontesthes perugiae complex.

PubMed Central

Beheregaray, Luciano B; Sunnucks, Paul; Briscoe, David A

2002-01-01

Coastal freshwater fishes provide valuable models for studying the role of the last glaciations in promoting speciation. To date, the great majority of studies are of Northern Hemisphere taxa, and reflect the influence of vicariant events during, or prior to, the Pleistocene. Microsatellite markers and mitochondrial DNA sequences were used to investigate patterns of population divergence and evolutionary relationships in a freshwater group of silverside fishes (Odontesthes perugiae complex), endemic to the recently formed coastal plain of southern Brazil. Lacustrine morphotypes showed concordant patterns of genetic and morphological divergence consistent with the geographical history of the coastal plain. The results support the proposal of a silverside radiation chronologically shaped by the sea-level changes of the Pleistocene and Holocene. The radiating lineage comprises a minimum of three allopatric and two sympatric lacustrine species. Four species displayed extremely high levels of genetic variation and some of the most rapid speciation rates reported in fishes. These features were related to a marine-estuarine origin of the radiation. To the best of our knowledge, this study represents the first molecular phylogeographic survey of a coastal radiation in South America. PMID:11788038

Rapid and recent diversification patterns in Anseriformes birds: Inferred from molecular phylogeny and diversification analyses.

PubMed

Sun, Zhonglou; Pan, Tao; Hu, Chaochao; Sun, Lu; Ding, Hengwu; Wang, Hui; Zhang, Chenling; Jin, Hong; Chang, Qing; Kan, Xianzhao; Zhang, Baowei

2017-01-01

The Anseriformes is a well-known and widely distributed bird order, with more than 150 species in the world. This paper aims to revise the classification, determine the phylogenetic relationships and diversification patterns in Anseriformes by exploring the Cyt b, ND2, COI genes and the complete mitochondrial genomes (mito-genomes). Molecular phylogeny and genetic distance analyses suggest that the Dendrocygna species should be considered as an independent family, Dendrocygnidae, rather than a member of Anatidae. Molecular timescale analyses suggests that the ancestral diversification occurred during the Early Eocene Climatic Optimum (58 ~ 50 Ma). Furthermore, diversification analyses showed that, after a long period of constant diversification, the median initial speciation rate was accelerated three times, and finally increased to approximately 0.3 sp/My. In the present study, both molecular phylogeny and diversification analyses results support that Anseriformes birds underwent rapid and recent diversification in their evolutionary history, especially in modern ducks, which show extreme diversification during the Plio-Pleistocene (~ 5.3 Ma). Therefore, our study support that the Plio-Pleistocene climate fluctuations are likely to have played a significant role in promoting the recent diversification for Anseriformes.

Force regulated dynamics of RPA on a DNA fork

PubMed Central

Kemmerich, Felix E.; Daldrop, Peter; Pinto, Cosimo; Levikova, Maryna; Cejka, Petr; Seidel, Ralf

2016-01-01

Replication protein A (RPA) is a single-stranded DNA binding protein, involved in most aspects of eukaryotic DNA metabolism. Here, we study the behavior of RPA on a DNA substrate that mimics a replication fork. Using magnetic tweezers we show that both yeast and human RPA can open forked DNA when sufficient external tension is applied. In contrast, at low force, RPA becomes rapidly displaced by the rehybridization of the DNA fork. This process appears to be governed by the binding or the release of an RPA microdomain (toehold) of only few base-pairs length. This gives rise to an extremely rapid exchange dynamics of RPA at the fork. Fork rezipping rates reach up to hundreds of base-pairs per second, being orders of magnitude faster than RPA dissociation from ssDNA alone. Additionally, we show that RPA undergoes diffusive motion on ssDNA, such that it can be pushed over long distances by a rezipping fork. Generally the behavior of both human and yeast RPA homologs is very similar. However, in contrast to yeast RPA, the dissociation of human RPA from ssDNA is greatly reduced at low Mg2+ concentrations, such that human RPA can melt DNA in absence of force. PMID:27016742

Evolution and outburst risk analysis of moraine-dammed lakes in the central Chinese Himalaya

NASA Astrophysics Data System (ADS)

Shijin, Wang; Shitai, Jiao

2015-04-01

The recent evolution and outburst risk of two typical moraine-dammed lakes, Galong and Gangxi, central Chinese Himalaya, are analyzed using topographic maps from 1974 and Landsat satellite imagery acquired in 1988, 2000 and 2014. The datasets show the areas of Galong and Gangxi lakes increasing at rates of 0.45 and 0.34 km2/year during the period 1974-2014, an expansion of 501% and 107%, respectively, in the past 41 years, while the areas of the parent glaciers, Reqiang and Jipucong decreased by 44.22% and 37.76%, respectively. The accelerating retreat of the glaciers not only reflects their generally negative mass balance but is consistent with the rapid expansion of the moraine-dammed lakes. When acted upon by external forces such as earthquakes, heavy rainfall, rapid melting of glaciers and dead ice, and snow/ice/rock avalanches, these lakes can become extremely dangerous, easily forming outburst mudslides, which can potentially spread to the Poiqu river basin and develop into cross-border (China and Nepal) GLOF disasters. Therefore, there is an urgent need to strengthen integrated risk management of glacial lake outburst disasters with multiple objectives and modes.

A Basic Behavior of CNG DI Combustion in a Spark-Ignited Rapid Compression Machine

NASA Astrophysics Data System (ADS)

Huang, Zuohua; Shiga, Seiichi; Ueda, Takamasa; Jingu, Nobuhisa; Nakamura, Hisao; Ishima, Tsuneaki; Obokata, Tomio; Tsue, Mitsuhiro; Kono, Michikata

A basic characteristics of compressed natural gas direct-injection (CNG DI) combustion was studied by using a rapid compression machine. Results show that comparing with homogeneous mixture, CNG DI has short combustion duration, high pressure rise due to combustion, and high rate of heat release, which are considered to come from the charge stratification and the gas flow generated by the fuel injection. CNG DI can realize extremely lean combustion which reaches 0.03 equivalence ratio, φ. Combustion duration, maximum pressure rise due to combustion and combustion efficiency are found to be insensitive to the injection modes. Unburned methane showed almost the same level as that of homogeneous mixture combustion. CO increased steeply with the increase in φ when φ was greater than 0.8 due to the excessive stratification, and NOx peak value shifted to the region of lower φ. Combustion inefficiency maintains less than 0.08 in the range of φ from 0.1 to 0.9 and increases at very low φ due to bulk quenching and at higher φ due to excessive stratification. The combustion efficiency estimated from combustion products shows good agreement with that of heat release analysis.

Diffuse optical characterization of an exercising patient group with peripheral artery disease

PubMed Central

Putt, Mary; Chandra, Malavika; Yu, Guoqiang; Xing, Xiaoman; Han, Sung Wan; Lech, Gwen; Shang, Yu; Durduran, Turgut; Zhou, Chao; Yodh, Arjun G.; Mohler, Emile R.

2013-01-01

Abstract. Peripheral artery disease (PAD) is a common condition with high morbidity. While measurement of tissue oxygen saturation (StO2) has been demonstrated, this is the first study to assess both StO2 and relative blood flow (rBF) in the extremities of PAD patients. Diffuse optics is employed to measure hemodynamic response to treadmill and pedal exercises in 31 healthy controls and 26 patients. For StO2, mild and moderate/severe PAD groups show pronounced differences compared with controls. Pre-exercise mean StO2 is lower in PAD groups by 9.3% to 10.6% compared with means of 63.5% to 66.2% in controls. For pedal, relative rate of return of StO2 to baseline is more rapid in controls (p<0.05). Patterns of rBF also differ among groups. After both exercises, rBF tend to occur at depressed levels among severe PAD patients compared with healthy (p<0.05); post-treadmill, rBF tend to occur at elevated levels among healthy compared with severe PAD patients (p<0.05). Additionally, relative rate of return to baseline StO2 is more rapid among subjects with reduced levels of depression in rBF (p=0.041), even after adjustment for ankle brachial index. This suggests a physiologic connection between rBF and oxygenation that can be measured using diffuse optics, and potentially employed as an evaluative tool in further studies. PMID:23708193

Remagnetization of lava flows spanning the last geomagnetic reversal

NASA Astrophysics Data System (ADS)

Vella, Jérôme; Carlut, Julie; Valet, Jean-Pierre; Goff, Maxime Le; Soler, Vicente; Lopes, Fernando

2017-08-01

Large directional changes of remanent magnetization within lava flows that cooled during geomagnetic reversals have been reported in several studies. A geomagnetic scenario implies extremely rapid geomagnetic changes of several degrees per day, thus difficult to reconcile with the rate of the earth's core liquid motions. So far, no complete rock magnetic model provides a clear explanation. We revisited lava flows sandwiched between an underlying reverse and an overlying normal polarity flow marking the last reversal in three distinct volcanic sequences of the La Palma Island (Canary archipelago, Spain) that are characterized by a gradual evolution of the direction of their remanent magnetization from bottom to top. Cleaning efficiency of thermal demagnetization was not improved by very rapid heating and cooling rates as well as by continuous demagnetization using a Triaxe magnetometer. We did not observe partial self-reversals and minor changes in magnetic grain sizes are not related to the within-flow directional changes. Microscopic observations indicate poor exsolution, which suggests post-cooling thermochemical remagnetization processes. This scenario is strongly reinforced by laboratory experiments that show large resistance to thermal demagnetization when thermoremanence was acquired over a long time period. We speculate that in the present situation exsolution was reactivated during in field reheating and yielded formation of new magnetite, yet magnetic domain state rearrangements could also play a role. Initial reheating when the overlying flow took place, albeit moderate (less than 200-300 °C), was enough to produce overlying components with significantly higher unblocking temperatures.

The Interplanetary and Magnetospheric Causes of Extreme DB/dt at Equatorial Locations

NASA Technical Reports Server (NTRS)

Adebesin, Babatunde O.; Pulkkinen, Antti; Ngwira, Chigomezyo M.

2016-01-01

The 1 min resolution solar wind and geomagnetic data obtained from seven equatorial low-latitude stations during four extreme geomagnetic activities are used to investigate the extreme dB/dt perturbations. Simulations of the magnetospheric-ionospheric environment were also performed for varying amplitudes of the solar proton density. Simulations were carried out using the Space Weather Modeling Framework BATS-R-US + RCM model. Both the observations and simulations demonstrated that the appearance time of the extreme dB/dt perturbations at equatorial stations during disturbed conditions is instantaneous and equitable to those experienced at auroral regions yielding time lags of the order of a few seconds. We find that the rapid dB/dt enhancements are caused by the electric field of magnetospheric current origin, which is being enhanced by solar wind density and ram pressure variations and boosted by the equatorial electro jet. Our results indicate that the solar wind proton density variations could be used as a predictor of extreme dB/dt enhancement at equatorial latitudes.

The interplanetary and magnetospheric causes of extreme dB/dt at equatorial locations

NASA Astrophysics Data System (ADS)

Adebesin, Babatunde O.; Pulkkinen, Antti; Ngwira, Chigomezyo M.

2016-11-01

The 1 min resolution solar wind and geomagnetic data obtained from seven equatorial/low-latitude stations during four extreme geomagnetic activities are used to investigate the extreme dB/dt perturbations. Simulations of the magnetospheric-ionospheric environment were also performed for varying amplitudes of the solar proton density. Simulations were carried out using the Space Weather Modeling Framework/BATS-R-US + RCM model. Both the observations and simulations demonstrated that the appearance time of the extreme dB/dt perturbations at equatorial stations during disturbed conditions is instantaneous and equitable to those experienced at auroral regions yielding time lags of the order of a few seconds. We find that the rapid dB/dt enhancements are caused by the electric field of magnetospheric current origin, which is being enhanced by solar wind density and ram pressure variations and boosted by the equatorial electrojet. Our results indicate that the solar wind proton density variations could be used as a predictor of extreme dB/dt enhancement at equatorial latitudes.

Spatial distribution of temperature trends and extremes over Maharashtra and Karnataka States of India

NASA Astrophysics Data System (ADS)

Dhorde, Amit G.; Korade, Mahendra S.; Dhorde, Anargha A.

2017-10-01

Earth surface temperatures are changing worldwide together with the changes in the extreme temperatures. The present study investigates trends and variations of monthly maximum and minimum temperatures and their effects on seasonal fluctuations at different climatological stations of Maharashtra and Karnataka states of India. Trend analysis was performed on annual and seasonal mean maximum temperature (TMAX) and mean minimum temperature (TMIN) for the period 1969 to 2006. During the last 38 years, an increase in annual TMAX and TMIN has occurred. At most of the locations, the increase in TMAX was faster than the TMIN, resulting in an increase in diurnal temperature range. At the same time, annual mean temperature (TM) showed a significant increase over the study area. Percentiles were used to identify extreme temperature indices. An increase in occurrence of warm extremes was observed at southern locations, and cold extremes increased over the central and northeastern part of the study area. Occurrences of cold wave conditions have decreased rapidly compared to heat wave conditions.

Diversity of Riparian Plants among and within Species Shapes River Communities

PubMed Central

Jackrel, Sara L.; Wootton, J. Timothy

2015-01-01

Organismal diversity among and within species may affect ecosystem function with effects transmitting across ecosystem boundaries. Whether recipient communities adjust their composition, in turn, to maximize their function in response to changes in donor composition at these two scales of diversity is unknown. We use small stream communities that rely on riparian subsidies as a model system. We used leaf pack experiments to ask how variation in plants growing beside streams in the Olympic Peninsula of Washington State, USA affects stream communities via leaf subsidies. Leaves from red alder (Alnus rubra), vine maple (Acer cinereus), bigleaf maple (Acer macrophyllum) and western hemlock (Tsuga heterophylla) were assembled in leaf packs to contrast low versus high diversity, and deployed in streams to compare local versus non-local leaf sources at the among and within species scales. Leaves from individuals within species decomposed at varying rates; most notably thin leaves decomposed rapidly. Among deciduous species, vine maple decomposed most rapidly, harbored the least algal abundance, and supported the greatest diversity of aquatic invertebrates, while bigleaf maple was at the opposite extreme for these three metrics. Recipient communities decomposed leaves from local species rapidly: leaves from early successional plants decomposed rapidly in stream reaches surrounded by early successional forest and leaves from later successional plants decomposed rapidly adjacent to later successional forest. The species diversity of leaves inconsistently affected decomposition, algal abundance and invertebrate metrics. Intraspecific diversity of leaf packs also did not affect decomposition or invertebrate diversity. However, locally sourced alder leaves decomposed more rapidly and harbored greater levels of algae than leaves sourced from conspecifics growing in other areas on the Olympic Peninsula, but did not harbor greater aquatic invertebrate diversity. In contrast to alder, local intraspecific differences via decomposition, algal or invertebrate metrics were not observed consistently among maples. These results emphasize that biodiversity of riparian subsidies at the within and across species scale have the potential to affect aquatic ecosystems, although there are complex species-specific effects. PMID:26539714

Diversity of Riparian Plants among and within Species Shapes River Communities.

PubMed

Jackrel, Sara L; Wootton, J Timothy

2015-01-01

Organismal diversity among and within species may affect ecosystem function with effects transmitting across ecosystem boundaries. Whether recipient communities adjust their composition, in turn, to maximize their function in response to changes in donor composition at these two scales of diversity is unknown. We use small stream communities that rely on riparian subsidies as a model system. We used leaf pack experiments to ask how variation in plants growing beside streams in the Olympic Peninsula of Washington State, USA affects stream communities via leaf subsidies. Leaves from red alder (Alnus rubra), vine maple (Acer cinereus), bigleaf maple (Acer macrophyllum) and western hemlock (Tsuga heterophylla) were assembled in leaf packs to contrast low versus high diversity, and deployed in streams to compare local versus non-local leaf sources at the among and within species scales. Leaves from individuals within species decomposed at varying rates; most notably thin leaves decomposed rapidly. Among deciduous species, vine maple decomposed most rapidly, harbored the least algal abundance, and supported the greatest diversity of aquatic invertebrates, while bigleaf maple was at the opposite extreme for these three metrics. Recipient communities decomposed leaves from local species rapidly: leaves from early successional plants decomposed rapidly in stream reaches surrounded by early successional forest and leaves from later successional plants decomposed rapidly adjacent to later successional forest. The species diversity of leaves inconsistently affected decomposition, algal abundance and invertebrate metrics. Intraspecific diversity of leaf packs also did not affect decomposition or invertebrate diversity. However, locally sourced alder leaves decomposed more rapidly and harbored greater levels of algae than leaves sourced from conspecifics growing in other areas on the Olympic Peninsula, but did not harbor greater aquatic invertebrate diversity. In contrast to alder, local intraspecific differences via decomposition, algal or invertebrate metrics were not observed consistently among maples. These results emphasize that biodiversity of riparian subsidies at the within and across species scale have the potential to affect aquatic ecosystems, although there are complex species-specific effects.

Evaluation of rapid progressors in HIV infection as an extreme phenotype.

PubMed

Olson, Ashley D; Guiguet, Marguerite; Zangerle, Robert; Gill, John; Perez-Hoyos, Santiago; Lodi, Sara; Ghosn, Jade; Dorrucci, Maria; Johnson, Anne; Sannes, Mette; Moreno, Santiago; Porter, Kholoud

2014-09-01

Rapid CD4 cell loss represents an HIV phenotype used to identify causal variants of accelerated disease progression. The optimal rate and threshold for identifying this extreme phenotype in recently infected individuals is unclear. Using a cohort of patients with known dates of HIV-1 seroconversion (SC), CASCADE (Concerted Action on SeroConversion on AIDS and Death in Europe), we identified proportions experiencing nadir CD4 cell levels within 1 year of SC, and assessed their mean AIDS-free survival time at 10-year follow-up and hazard of AIDS/death, compared with those whose CD4 remained >500 cells per cubic millimeter. Follow-up was censored at December 31, 1996 to avoid bias due to combination antiretroviral therapy initiation. Of 4876 individuals, 2.8%, 7.3%, and 24.9% experienced ≥1 CD4 <100, 200, and 350 cells per cubic millimeter, respectively, within 1 year of SC. Minimum CD4 levels of 30, 166, 231, and 506 cells per cubic millimeter were experienced during this period by 1%, 5%, 10%, and 50% of individuals, respectively. Mean (95% confidence interval) AIDS-free survival at 10 years follow-up was 2.9 (2.3 to 3.6), 5.5 (5.0 to 6.1), 6.7 (6.5 to 7.0), 7.4 (7.2 to 7.6), and 8.1 (7.9 to 8.3), for those with minimum counts ≤100, 100-200, 200-350, 350-500, >500 cells per cubic millimeter, respectively. Using counts of >500 cells per cubic millimeter as reference, the hazard ratios (95% confidence interval) of AIDS/death were 15.0 (11.9 to 18.9), 3.6 (2.9 to 4.5), 2.1 (1.8 to 2.4), and 1.5 (1.3 to 1.7), respectively. The hazard ratio increased to 37.5 (26.5 to 53.1) when a minimum CD4 count <100 was confirmed within 1 year of SC. At least 1 CD4 ≤100 cells per cubic millimeter within the first year of SC identifies a rare group of individuals at high risk of disease progression and could form the basis for defining the rapid progressor phenotype.

Recovery of uranium from seawater by immobilized tannin

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

Sakaguchi, T.; Nakajima, A.

1987-06-01

Tannin compounds having multiple adjacent hydroxy groups have an extremely high affinity for uranium. To prevent the leaching of tannins into water and to improve the adsorbing characteristics of these compounds, the authors tried to immobilize tannins. The immobilized tannin has the most favorable features for uranium recovery; high selective adsorption ability to uranium, rapid adsorption rate, and applicability in both column and batch systems. The immobilized tannin can recover uranium from natural seawater with high efficiency. About 2530 ..mu..g uranium is adsorbed per gram of this adsorbent within 22 h. Depending on the concentration in seawater, an enrichment ofmore » up to 766,000-fold within the adsorbent is possible. Almost all uranium adsorbed is easily desorbed with a very dilute acid. Thus, the immobilized tannin can be used repeatedly in the adsorption-desorption process.« less

The rate of planet formation and the solar system's small bodies

NASA Technical Reports Server (NTRS)

Safronov, Viktor S.

1991-01-01

The evolution of random velocities and the mass distribution of preplanetary body at the early stage of accumulation are currently under review. Arguments were presented for and against the view of an extremely rapid, runaway growth of the largest bodies at this stage with parameter values of Theta approximately greater than 10(exp 3). Difficulties are encountered assuming such a large Theta: (1) bodies of the Jovian zone penetrate the asteroid zone too late and do not have time to hinder the formation of a normal-sized planet in the asteroidal zone and thereby remove a significant portion of the mass of solid matter and (2) Uranus and Neptune cannot eject bodies from the solar system into the cometary cloud. Therefore, the values Theta less than 10(exp 2) appear to be preferable.

Detection of algorithmic trading

NASA Astrophysics Data System (ADS)

Bogoev, Dimitar; Karam, Arzé

2017-10-01

We develop a new approach to reflect the behavior of algorithmic traders. Specifically, we provide an analytical and tractable way to infer patterns of quote volatility and price momentum consistent with different types of strategies employed by algorithmic traders, and we propose two ratios to quantify these patterns. Quote volatility ratio is based on the rate of oscillation of the best ask and best bid quotes over an extremely short period of time; whereas price momentum ratio is based on identifying patterns of rapid upward or downward movement in prices. The two ratios are evaluated across several asset classes. We further run a two-stage Artificial Neural Network experiment on the quote volatility ratio; the first stage is used to detect the quote volatility patterns resulting from algorithmic activity, while the second is used to validate the quality of signal detection provided by our measure.

The Distribution and Annihilation of Dark Matter Around Black Holes

NASA Technical Reports Server (NTRS)

Schnittman, Jeremy D.

2015-01-01

We use a Monte Carlo code to calculate the geodesic orbits of test particles around Kerr black holes, generating a distribution function of both bound and unbound populations of dark matter (DM) particles. From this distribution function, we calculate annihilation rates and observable gamma-ray spectra for a few simple DM models. The features of these spectra are sensitive to the black hole spin, observer inclination, and detailed properties of the DM annihilation cross-section and density profile. Confirming earlier analytic work, we find that for rapidly spinning black holes, the collisional Penrose process can reach efficiencies exceeding 600%, leading to a high-energy tail in the annihilation spectrum. The high particle density and large proper volume of the region immediately surrounding the horizon ensures that the observed flux from these extreme events is non-negligible.

Natural scene logo recognition by joint boosting feature selection in salient regions

NASA Astrophysics Data System (ADS)

Fan, Wei; Sun, Jun; Naoi, Satoshi; Minagawa, Akihiro; Hotta, Yoshinobu

2011-01-01

Logos are considered valuable intellectual properties and a key component of the goodwill of a business. In this paper, we propose a natural scene logo recognition method which is segmentation-free and capable of processing images extremely rapidly and achieving high recognition rates. The classifiers for each logo are trained jointly, rather than independently. In this way, common features can be shared across multiple classes for better generalization. To deal with large range of aspect ratio of different logos, a set of salient regions of interest (ROI) are extracted to describe each class. We ensure the selected ROIs to be both individually informative and two-by-two weakly dependant by a Class Conditional Entropy Maximization criteria. Experimental results on a large logo database demonstrate the effectiveness and efficiency of our proposed method.

Whole-Genome Sequencing of Native Sheep Provides Insights into Rapid Adaptations to Extreme Environments.

PubMed

Yang, Ji; Li, Wen-Rong; Lv, Feng-Hua; He, San-Gang; Tian, Shi-Lin; Peng, Wei-Feng; Sun, Ya-Wei; Zhao, Yong-Xin; Tu, Xiao-Long; Zhang, Min; Xie, Xing-Long; Wang, Yu-Tao; Li, Jin-Quan; Liu, Yong-Gang; Shen, Zhi-Qiang; Wang, Feng; Liu, Guang-Jian; Lu, Hong-Feng; Kantanen, Juha; Han, Jian-Lin; Li, Meng-Hua; Liu, Ming-Jun

2016-10-01

Global climate change has a significant effect on extreme environments and a profound influence on species survival. However, little is known of the genome-wide pattern of livestock adaptations to extreme environments over a short time frame following domestication. Sheep (Ovis aries) have become well adapted to a diverse range of agroecological zones, including certain extreme environments (e.g., plateaus and deserts), during their post-domestication (approximately 8-9 kya) migration and differentiation. Here, we generated whole-genome sequences from 77 native sheep, with an average effective sequencing depth of ∼5× for 75 samples and ∼42× for 2 samples. Comparative genomic analyses among sheep in contrasting environments, that is, plateau (>4,000 m above sea level) versus lowland (<100 m), high-altitude region (>1500 m) versus low-altitude region (<1300 m), desert (<10 mm average annual precipitation) versus highly humid region (>600 mm), and arid zone (<400 mm) versus humid zone (>400 mm), detected a novel set of candidate genes as well as pathways and GO categories that are putatively associated with hypoxia responses at high altitudes and water reabsorption in arid environments. In addition, candidate genes and GO terms functionally related to energy metabolism and body size variations were identified. This study offers novel insights into rapid genomic adaptations to extreme environments in sheep and other animals, and provides a valuable resource for future research on livestock breeding in response to climate change. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Social Diffusion of Water Conservation: A Study of Residential Turf Rebate Programs in Orange County, California

NASA Astrophysics Data System (ADS)

Duong, K.; Grant, S. B.; Rippy, M.; Feldman, D.

2017-12-01

From 2011 to 2017, the combination of record low precipitation and extreme warm temperatures resulted in the most severe drought in California's written history. In April 2015, Governor Jerry Brown issued an executive order mandating a statewide 25% reduction in potable urban water usage. Under such circumstances, outdoor watering is an obvious target for restriction, because it can account for a large fraction of total domestic water usage, up to 50% in the arid southwest [Syme et. al 2004, Cameron et. al 2012]. In this study we analyzed one such effort, in which the Irvine Ranch Water District (IRWD) in Orange County (California) offered a financial incentive through a turf rebate program to encourage Irvine residents to replace turf grass with drought tolerant landscaping. We focused specifically on the number of residents who applied to the turf rebate program. Our hypothesis was that the observed application rate (number of applicants per month) is influenced by a combination of (a) financial incentives issued by IRWD, (b) drought awareness, and (c) the fraction of neighbors that have already applied to the program (a phenomenon that can be described quantitatively through models of social contagion or social diffusion [Karsai et. al 2014]). Our preliminary results indicate that applications to the program occurred in geographic "hot spots", consistent with the idea that early adopters may have influenced neighbors to retrofit their lawns. We are currently evaluating the geographic, demographic, and temporal drivers that influence the rate of spontaneous adoption, the rate of adoption under influence, and the total size of the susceptible population. Overall, our goal is to identify the key factors that contribute to early rapid uptake of conservation behavior, and the rapid diffusion of that behavior through the community.

The chemical evolution of a travertine-depositing stream: Geochemical processes and mass transfer reactions

USGS Publications Warehouse

Lorah, Michelle M.; Herman, Janet S.

1988-01-01

This field study focuses on quantitatively defining the chemical changes occurring in Falling Spring Creek, a travertine-depositing stream located in Alleghany County, Virginia. The processes of CO2outgassing and calcite precipitation or dissolution control the chemical evolution of the stream. The observed chemical composition of the water was used with the computerized geochemical model WATEQF to calculate aqueous speciation, saturation indices, and CO2 partial pressure values. Mass balance calculations were performed to obtain mass transfers of CO2 and calcite. Reaction times, estimated from stream discharge, were used with the mass transfer results to calculate rates of CO2, outgassing and calcite precipitation between consecutive sampling points. The stream, which is fed by a carbonate spring, is supersaturated with respect to CO2 along the entire 5.2-km flow path. Outgassing of CO2 drives the solution to high degrees of supersaturation with respect to calcite. Metabolic uptake of CO2 by photosynthetic plants is insignificant, because the high supply rate of dissolved carbon dioxide and the extreme agitation of the stream at waterfalls and rapids causes a much greater amount of inorganic CO2 outgassing to occur. Calcite precipitation is kinetically inhibited until near the crest of a 20-m vertical waterfall. Calcite precipitation rates then reach a maximum at the waterfall where greater water turbulence allows the most rapid escape of CO2. Physical evidence for calcite precipitation exists in the travertine deposits which are first observed immediately above the waterfall and extend for at least 1.0 km below the falls. Net calcite precipitation occurs at all times of the year but is greatest during low-flow conditions in the summer and early fall.

Claims incidence of work-related disorders of the upper extremities: Washington state, 1987 through 1995.

PubMed

Silverstein, B; Welp, E; Nelson, N; Kalat, J

1998-12-01

This study examined the claim incidence rate, cost, and industry distribution of work-related upper extremity disorders in Washington. Washington State Fund workers' compensation claims from 1987 to 1995 were abstracted and categorized into general and specific disorders of gradual or sudden onset. Accepted claims included 100,449 for hand/wrist disorders (incidence rate: 98.2/10,000 full-time equivalents; carpal tunnel syndrome rate: 27.3), 30,468 for elbow disorders (incidence rate: 29.7; epicondylitis rate: 11.7), and 55,315 for shoulder disorders (incidence rate: 54.0; rotator cuff syndrome rate: 19.9). Average direct workers' compensation claims costs (medical treatment and indemnity) were $15,790 (median: $6774) for rotator cuff syndrome, $12,794 for carpal tunnel syndrome (median: $4190), and $6593 for epicondylitis (median: $534). Construction and food processing were among the industries with the highest rate ratios for all disorders (> 4.0). Upper extremity disorders represent a large and costly problem in Washington State industry. Industries characterized by manual handling and repetitive work have high rate ratios. The contingent workforce appears to be at high risk.

Dispersal and deposition of river sediments in coastal seas: Models from Asia and the tropics

NASA Astrophysics Data System (ADS)

Wright, L. D.

The diverse mechanisms by which river-borne sediments are dispersed into coastal oceans and the associated patterns of deposition are considered for some tropical and Asian river mouth dispersal systems: the Huanghe (Yellow River), which enters the Bohai Gulf (China), the Purari River which enters the Gulf of Papua (Papua New Guinea) and the Jaba River, which enters Empress Augusta Bay (Bougainville, Papua New Guinea). These models contrast sharply with 'conventional' models such as that of the Mississippi, although in different respects. Extremely high suspended sediment concentrations off the Huanghe mouth cause sinking, gravity-driven plumes which produce rapid deposition very near the mouth; extremely rapid seaward growth of the subaqueous delta results. Although the average water discharge of the Purari exceeds that of the Huanghe, the average sediment discharge from the Purari is an order of magnitude less than that of the Huanghe. Suspended sediments transported via buoyant plumes from the Purari mouth are trapped inshore by the southeasterly trades and have their ultimate sink in the tidal estuaries to the west of the mouths rather than offshore. The Jaba is a small river with a very steep gradient and an extremely high bed load relative to water discharge. It has constructed a protruding and rapidly evolving delta. Literature on the Indonesian rivers Solo and Porong dispersal systems suggests that those systems may, at different times, be subject to processes similar to those which operate off the mouths of the Huanghe, Purari and Jaba although no single, direct analogies can be made.

Prediction of a thermodynamic wave train from the monsoon to the Arctic following extreme rainfall events

NASA Astrophysics Data System (ADS)

Krishnamurti, T. N.; Kumar, Vinay

2017-04-01

This study addresses numerical prediction of atmospheric wave trains that provide a monsoonal link to the Arctic ice melt. The monsoonal link is one of several ways that heat is conveyed to the Arctic region. This study follows a detailed observational study on thermodynamic wave trains that are initiated by extreme rain events of the northern summer south Asian monsoon. These wave trains carry large values of heat content anomalies, heat transports and convergence of flux of heat. These features seem to be important candidates for the rapid melt scenario. This present study addresses numerical simulation of the extreme rains, over India and Pakistan, and the generation of thermodynamic wave trains, simulations of large heat content anomalies, heat transports along pathways and heat flux convergences, potential vorticity and the diabatic generation of potential vorticity. We compare model based simulation of many features such as precipitation, divergence and the divergent wind with those evaluated from the reanalysis fields. We have also examined the snow and ice cover data sets during and after these events. This modeling study supports our recent observational findings on the monsoonal link to the rapid Arctic ice melt of the Canadian Arctic. This numerical modeling suggests ways to interpret some recent episodes of rapid ice melts that may require a well-coordinated field experiment among atmosphere, ocean, ice and snow cover scientists. Such a well-coordinated study would sharpen our understanding of this one component of the ice melt, i.e. the monsoonal link, which appears to be fairly robust.

Origin and dynamics of depositionary subduction margins

USGS Publications Warehouse

Vannucchi, Paola; Morgan, Jason P.; Silver, Eli; Kluesner, Jared W.

2016-01-01

Here we propose a new framework for forearc evolution that focuses on the potential feedbacks between subduction tectonics, sedimentation, and geomorphology that take place during an extreme event of subduction erosion. These feedbacks can lead to the creation of a “depositionary forearc,” a forearc structure that extends the traditional division of forearcs into accretionary or erosive subduction margins by demonstrating a mode of rapid basin accretion during an erosive event at a subduction margin. A depositionary mode of forearc evolution occurs when terrigenous sediments are deposited directly on the forearc while it is being removed from below by subduction erosion. In the most extreme case, an entire forearc can be removed by a single subduction erosion event followed by depositionary replacement without involving transfer of sediments from the incoming plate. We need to further recognize that subduction forearcs are often shaped by interactions between slow, long-term processes, and sudden extreme events reflecting the sudden influences of large-scale morphological variations in the incoming plate. Both types of processes contribute to the large-scale architecture of the forearc, with extreme events associated with a replacive depositionary mode that rapidly creates sections of a typical forearc margin. The persistent upward diversion of the megathrust is likely to affect its geometry, frictional nature, and hydrogeology. Therefore, the stresses along the fault and individual earthquake rupture characteristics are also expected to be more variable in these erosive systems than in systems with long-lived megathrust surfaces.

Fast-acting valve actuator

DOEpatents

Cho, Nakwon

1980-01-01

A fast-acting valve actuator utilizes a spring driven pneumatically loaded piston to drive a valve gate. Rapid exhaust of pressurized gas from the pneumatically loaded side of the piston facilitates an extremely rapid piston stroke. A flexible selector diaphragm opens and closes an exhaust port in response to pressure differentials created by energizing and de-energizing a solenoid which controls the pneumatic input to the actuator as well as selectively providing a venting action to one side of the selector diaphragm.

Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

PubMed Central

Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

2015-01-01

Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s−1 is generated at 22.3 eV, with 5 × 10−5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications. PMID:26067922

40 CFR 80.560 - How can a refiner seek temporary relief from the requirements of this subpart in case of extreme...

Code of Federal Regulations, 2010 CFR

2010-07-01

... for NRLM diesel fuel; (2) Bond rating of entity that owns the refinery (in the case of joint ventures, include the bond rating of the joint venture entity and the bond ratings of all partners; in the case of... relief from the requirements of this subpart in case of extreme hardship circumstances? 80.560 Section 80...

Long distance migratory songbirds respond to extremes in arctic seasonality

NASA Astrophysics Data System (ADS)

Boelman, N.; Asmus, A.; Chmura, H.; Krause, J.; Perez, J. H.; Sweet, S. K.; Gough, L.; Wingfield, J.

2017-12-01

Arctic regions are warming rapidly, with extreme weather events increasing in frequency, duration and intensity, as in other regions. Many studies have focused on how shifting seasonality in environmental conditions affect the phenology and productivity of vegetation, while far fewer have examined how arctic fauna responds. We studied two species of long-distance migratory songbirds, Lapland longspurs, Calcarius lapponicus, and White-crowned sparrows, Zonotrichia leucophrys gambelii, across seven consecutive breeding seasons in northern Alaskan tundra. We aimed to understand how spring environmental conditions affected breeding cycle phenology, food availability, body condition, stress physiology, and ultimately, reproductive success. Spring temperatures, precipitation, storm frequency, and snow-free dates differed significantly among years, with 2013 characterized by unusually late snow cover, and 2015 and 2016 characterized by unusually early snow-free dates and several late spring snowstorms. In response, we found that relative to other study years, there was a significant delay in breeding cycle phenology for both study species in 2013, while breeding cycle phenology was significantly earlier in 2015 only. For both species, we also found significant variation among years in: the seasonal patterns of arthropod availability during the nesting stage; body condition, and; stress physiology. Finally, we found significant variation in reproductive success of both species across years, and that daily survival rates were decreased by snow storm events. Our findings suggest that arctic-breeding passerine communities may be able to adjust phenology to unpredictable shifts in the timing of spring, but extreme conditions during the incubation and nestling stages are detrimental to reproductive success.

Temporal and spatial characteristics of extreme precipitation events in the Midwest of Jilin Province based on multifractal detrended fluctuation analysis method and copula functions

NASA Astrophysics Data System (ADS)

Guo, Enliang; Zhang, Jiquan; Si, Ha; Dong, Zhenhua; Cao, Tiehua; Lan, Wu

2017-10-01

Environmental changes have brought about significant changes and challenges to water resources and management in the world; these include increasing climate variability, land use change, intensive agriculture, and rapid urbanization and industrial development, especially much more frequency extreme precipitation events. All of which greatly affect water resource and the development of social economy. In this study, we take extreme precipitation events in the Midwest of Jilin Province as an example; daily precipitation data during 1960-2014 are used. The threshold of extreme precipitation events is defined by multifractal detrended fluctuation analysis (MF-DFA) method. Extreme precipitation (EP), extreme precipitation ratio (EPR), and intensity of extreme precipitation (EPI) are selected as the extreme precipitation indicators, and then the Kolmogorov-Smirnov (K-S) test is employed to determine the optimal probability distribution function of extreme precipitation indicators. On this basis, copulas connect nonparametric estimation method and the Akaike Information Criterion (AIC) method is adopted to determine the bivariate copula function. Finally, we analyze the characteristics of single variable extremum and bivariate joint probability distribution of the extreme precipitation events. The results show that the threshold of extreme precipitation events in semi-arid areas is far less than that in subhumid areas. The extreme precipitation frequency shows a significant decline while the extreme precipitation intensity shows a trend of growth; there are significant differences in spatiotemporal of extreme precipitation events. The spatial variation trend of the joint return period gets shorter from the west to the east. The spatial distribution of co-occurrence return period takes on contrary changes and it is longer than the joint return period.

Diabetic ketoacidosis producing extreme hyperkalemia in a patient with type 1 diabetes on hemodialysis.

PubMed

Yamada, Hodaka; Funazaki, Shunsuke; Kakei, Masafumi; Hara, Kazuo; Ishikawa, San-E

2017-01-01

Diabetic ketoacidosis (DKA) is a critical complication of type 1 diabetes associated with water and electrolyte disorders. Here, we report a case of DKA with extreme hyperkalemia (9.0 mEq/L) in a patient with type 1 diabetes on hemodialysis. He had a left frontal cerebral infarction resulting in inability to manage his continuous subcutaneous insulin infusion pump. Electrocardiography showed typical changes of hyperkalemia, including absent P waves, prolonged QRS interval and tented T waves. There was no evidence of total body water deficit. After starting insulin and rapid hemodialysis, the serum potassium level was normalized. Although DKA may present with hypokalemia, rapid hemodialysis may be necessary to resolve severe hyperkalemia in a patient with renal failure. Patients with type 1 diabetes on hemodialysis may develop ketoacidosis because of discontinuation of insulin treatment.Patients on hemodialysis who develop ketoacidosis may have hyperkalemia because of anuria.Absolute insulin deficit alters potassium distribution between the intracellular and extracellular space, and anuria abolishes urinary excretion of potassium.Rapid hemodialysis along with intensive insulin therapy can improve hyperkalemia, while fluid infusions may worsen heart failure in patients with ketoacidosis who routinely require hemodialysis.

Changes in Extremely Hot Summers over the Global Land Area under Various Warming Targets

PubMed Central

Wang, Lei; Huang, Jianbin; Luo, Yong; Yao, Yao; Zhao, Zongci

2015-01-01

Summer temperature extremes over the global land area were investigated by comparing 26 models of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) with observations from the Goddard Institute for Space Studies (GISS) and the Climate Research Unit (CRU). Monthly data of the observations and models were averaged for each season, and statistics were calculated for individual models before averaging them to obtain ensemble means. The summers with temperature anomalies (relative to 1951–1980) exceeding 3σ (σ is based on the local internal variability) are defined as “extremely hot”. The models well reproduced the statistical characteristics evolution, and partly captured the spatial distributions of historical summer temperature extremes. If the global mean temperature increases 2°C relative to the pre-industrial level, “extremely hot” summers are projected to occur over nearly 40% of the land area (multi-model ensemble mean projection). Summers that exceed 5σ warming are projected to occur over approximately 10% of the global land area, which were rarely observed during the reference period. Scenarios reaching warming levels of 3°C to 5°C were also analyzed. After exceeding the 5°C warming target, “extremely hot” summers are projected to occur throughout the entire global land area, and summers that exceed 5σ warming would become common over 70% of the land area. In addition, the areas affected by “extremely hot” summers are expected to rapidly expand by more than 25%/°C as the global mean temperature increases by up to 3°C before slowing to less than 16%/°C as the temperature continues to increase by more than 3°C. The area that experiences summers with warming of 5σ or more above the warming target of 2°C is likely to maintain rapid expansion of greater than 17%/°C. To reduce the impacts and damage from severely hot summers, the global mean temperature increase should remain low. PMID:26090931

Extreme Precipitation and Emergency Room Visits for Gastrointestinal Illness in Areas with and without Combined Sewer Systems: An Analysis of Massachusetts Data, 2003–2007

PubMed Central

Li, Quanlin; Wang, Shiliang; Messier, Kyle P.; Wade, Timothy J.; Hilborn, Elizabeth D.

2015-01-01

Background Combined sewer overflows (CSOs) occur in combined sewer systems when sewage and stormwater runoff are released into water bodies, potentially contaminating water sources. CSOs are often caused by heavy precipitation and are expected to increase with increasing extreme precipitation associated with climate change. Objectives The aim of this study was to assess whether the association between heavy rainfall and rate of emergency room (ER) visits for gastrointestinal (GI) illness differed in the presence of CSOs. Methods For the study period 2003–2007, time series of daily rate of ER visits for GI illness and meteorological data were organized for three exposure regions: a) CSOs impacting drinking water sources, b) CSOs impacting recreational waters, c) no CSOs. A distributed lag Poisson regression assessed cumulative effects for an 8-day lag period following heavy (≥ 90th and ≥ 95th percentile) and extreme (≥ 99th percentile) precipitation events, controlling for temperature and long-term time trends. Results The association between extreme rainfall and rate of ER visits for GI illness differed among regions. Only the region with drinking water exposed to CSOs demonstrated a significant increased cumulative risk for rate (CRR) of ER visits for GI for all ages in the 8-day period following extreme rainfall: CRR: 1.13 (95% CI: 1.00, 1.28) compared with no rainfall. Conclusions The rate of ER visits for GI illness was associated with extreme precipitation in the area with CSO discharges to a drinking water source. Our findings suggest an increased risk for GI illness among consumers whose drinking water source may be impacted by CSOs after extreme precipitation. Citation Jagai JS, Li Q, Wang S, Messier KP, Wade TJ, Hilborn ED. 2015. Extreme precipitation and emergency room visits for gastrointestinal illness in areas with and without combined sewer systems: an analysis of Massachusetts data, 2003–2007. Environ Health Perspect 123:873–879; http://dx.doi.org/10.1289/ehp.1408971 PMID:25855939

Minimum important differences for the patient-specific functional scale, 4 region-specific outcome measures, and the numeric pain rating scale.

PubMed

Abbott, J Haxby; Schmitt, John

2014-08-01

Multicenter, prospective, longitudinal cohort study. To investigate the minimum important difference (MID) of the Patient-Specific Functional Scale (PSFS), 4 region-specific outcome measures, and the numeric pain rating scale (NPRS) across 3 levels of patient-perceived global rating of change in a clinical setting. The MID varies depending on the external anchor defining patient-perceived "importance." The MID for the PSFS has not been established across all body regions. One thousand seven hundred eight consecutive patients with musculoskeletal disorders were recruited from 5 physical therapy clinics. The PSFS, NPRS, and 4 region-specific outcome measures-the Oswestry Disability Index, Neck Disability Index, Upper Extremity Functional Index, and Lower Extremity Functional Scale-were assessed at the initial and final physical therapy visits. Global rating of change was assessed at the final visit. MID was calculated for the PSFS and NPRS (overall and for each body region), and for each region-specific outcome measure, across 3 levels of change defined by the global rating of change (small, medium, large change) using receiver operating characteristic curve methodology. The MID for the PSFS (on a scale from 0 to 10) ranged from 1.3 (small change) to 2.3 (medium change) to 2.7 (large change), and was relatively stable across body regions. MIDs for the NPRS (-1.5 to -3.5), Oswestry Disability Index (-12), Neck Disability Index (-14), Upper Extremity Functional Index (6 to 11), and Lower Extremity Functional Scale (9 to 16) are also reported. We reported the MID for small, medium, and large patient-perceived change on the PSFS, NPRS, Oswestry Disability Index, Neck Disability Index, Upper Extremity Functional Index, and Lower Extremity Functional Scale for use in clinical practice and research.

Injury incidence in hip hop dance.

PubMed

Ojofeitimi, S; Bronner, S; Woo, H

2012-06-01

Hip hop dance has rapidly become a popular international art form. There is limited information on injury patterns in this population. The purpose of this study was to determine injury incidence and patterns among three groups of hip hop dancers. Three hundred and twelve intermediate, advanced, and expert hip hop dancers were recruited at battles, dance conferences, clubs, and on dance related web sites within the United States and internationally. A Web-based survey was conducted over a 6-month period. Inclusion criteria included intermediate and advanced level dancers over the age of 13. Dancers were divided into three main categories: Breakers, Popper/Lockers, and New Schoolers. Separate analysis of variances were used to compare injury pattern differences between groups. Two hundred and thirty-two dancers reported a total of 738 injuries. Five hundred and six of these (sustained by 205 dancers) were time-loss (TL) injuries. Annual injury incidence was 237% (162% involving TL). Lower extremity injuries were 52% and upper extremity injuries 32% of total injuries. Breakers had a higher injury incidence compared with Popper/Lockers, and New Schoolers. Hip hop dancers report injury rates that are higher than other dance forms but similar to gymnastics. These dancers should be educated concerning injury prevention, biomechanics, and use of protective equipment. © 2010 John Wiley & Sons A/S.

Clinical aspects of percutaneous poisoning by the chemical warfare agent VX: effects of application site and decontamination.

PubMed

Hamilton, Murray G; Hill, Ira; Conley, John; Sawyer, Thomas W; Caneva, Duane C; Lundy, Paul M

2004-11-01

O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate (VX) is an extremely toxic organophosphate nerve agent that has been weaponized and stockpiled in a number of different countries, and it has been used in recent terrorist events. It differs from other well-known organophosphate nerve agents in that its primary use is as a contact poison rather than as an inhalation hazard. For this reason, we examined the effects of application site and skin decontamination on VX toxicity in anesthetized domestic swine after topical application. VX applied to the surface of the ear rapidly resulted in signs of toxicity consistent with the development of cholinergic crisis, including apnea and death. VX on the epigastrium resulted in a marked delayed development of toxic signs, reduced toxicity, and reduction in the rate of cholinesterase depression compared with animals exposed on the ear. Skin decontamination (15 minutes post-VX on the ear) arrested the development of clinical signs and prevented further cholinesterase inhibition and death. These results confirm earlier work that demonstrates the importance of exposure site on the resultant toxicity of this agent and they also show that decontamination postexposure has the potential to be an integral and extremely important component of medical countermeasures against this agent.

Prevention of Lower Extremity Injuries in Basketball

PubMed Central

Taylor, Jeffrey B.; Ford, Kevin R.; Nguyen, Anh-Dung; Terry, Lauren N.; Hegedus, Eric J.

2015-01-01

Context: Lower extremity injuries are common in basketball, yet it is unclear how prophylactic interventions affect lower extremity injury incidence rates. Objective: To analyze the effectiveness of current lower extremity injury prevention programs in basketball athletes, focusing on injury rates of (1) general lower extremity injuries, (2) ankle sprains, and (3) anterior cruciate ligament (ACL) tears. Data Sources: PubMed, MEDLINE, CINAHL, SPORTDiscus, and the Cochrane Register of Controlled Trials were searched in January 2015. Study Selection: Studies were included if they were randomized controlled or prospective cohort trials, contained a population of competitive basketball athletes, and reported lower extremity injury incidence rates specific to basketball players. In total, 426 individual studies were identified. Of these, 9 met the inclusion criteria. One other study was found during a hand search of the literature, resulting in 10 total studies included in this meta-analysis. Study Design: Systematic review and meta-analysis. Level of Evidence: Level 2. Data Extraction: Details of the intervention (eg, neuromuscular vs external support), size of control and intervention groups, and number of injuries in each group were extracted from each study. Injury data were classified into 3 groups based on the anatomic diagnosis reported (general lower extremity injury, ankle sprain, ACL rupture). Results: Meta-analyses were performed independently for each injury classification. Results indicate that prophylactic programs significantly reduced the incidence of general lower extremity injuries (odds ratio [OR], 0.69; 95% CI, 0.57-0.85; P < 0.001) and ankle sprains (OR, 0.45; 95% CI, 0.29-0.69; P < 0.001), yet not ACL ruptures (OR, 1.09; 95% CI, 0.36-3.29; P = 0.87) in basketball athletes. Conclusion: In basketball players, prophylactic programs may be effective in reducing the risk of general lower extremity injuries and ankle sprains, yet not ACL injuries. PMID:26502412

Development of Korean Academy of Medical Sciences Guideline for rating physical disability of upper extremity.

PubMed

Park, Jung Ho; Kim, Hee-Chun; Lee, Jae Hoon; Kim, Jin Soo; Roh, Si Young; Yi, Cheol Ho; Kang, Yoon Kyoo; Kwon, Bum Sun

2009-05-01

While the lower extremities support the weight and move the body, the upper extremities are essential for the activities of daily living, which require many detailed movements. Therefore, a disability of the upper extremity function should include a limitation of all motions of the joints and sensory loss, which affects the activities. In this study, disabilities of the upper extremities were evaluated according to the following conditions: 1) amputation, 2) joint contracture, 3) diseases of upper extremity, 4) weakness, 5) sensory loss of the finger tips, and 6) vascular and lymphatic diseases. The order of 1) to 6) is the order of major disability and there is no need to evaluate a lower order disability when a higher order one exists in the same joint or a part of the upper extremity. However, some disabilities can be either added or substituted when there are special contributions from multiple disabilities. An upper extremity disability should be evaluated after the completion of treatment and full adaptation when further functional changes are not expected. The dominance of the right or left hand before the disability should not be considered when there is a higher rate of disability.

A Library of Rad Hard Mixed-Voltage/Mixed-Signal Building Blocks for Integration of Avionics Systems for Deep Space

NASA Technical Reports Server (NTRS)

Mojarradi, M. M.; Blaes, B.; Kolawa, E. A.; Blalock, B. J.; Li, H. W.; Buck, K.; Houge, D.

2001-01-01

To build the sensor intensive system-on-a-chip for the next generation spacecrafts for deep space, Center for Integration of Space Microsystems at JPL (CISM) takes advantage of the lower power rating and inherent radiation resistance of Silicon on Insulator technology (SOI). We are developing a suite of mixed-voltage and mixed-signal building blocks in Honeywell's SOI process that can enable the rapid integration of the next generation avionics systems with lower power rating, higher reliability, longer life, and enhanced radiation tolerance for spacecrafts such as the Europa Orbiter and Europa Lander. The mixed-voltage building blocks are predominantly for design of adaptive power management systems. Their design centers around an LDMOS structure that is being developed by Honeywell, Boeing Corp, and the University of Idaho. The mixed-signal building blocks are designed to meet the low power, extreme radiation requirement of deep space applications. These building blocks are predominantly used to interface analog sensors to the digital CPU of the next generation avionics system on a chip. Additional information is contained in the original extended abstract.

Shock, release and Taylor impact of the semicrystalline thermoplastic polytetrafluoroethylene

NASA Astrophysics Data System (ADS)

Bourne, N. K.; Brown, E. N.; Millett, J. C. F.; Gray, G. T.

2008-04-01

The high strain-rate response of polymers is a subject that has gathered interest over recent years due to their increasing engineering importance, particularly in load bearing applications subject to extremes of pressure and strain rate. The current work presents two specific sets of experiments interrogating the effect of dynamic, high-pressure loading in the regime of the phase II to phase III pressure-induced crystalline phase transition in polytetrafluoroethylene (PTFE). These are gas-gun driven plate- and Taylor impact. Together these experiments highlight several effects associated with the dynamic, pressure-induced phase transitions in PTFE. An elevated release wave speed shows evidence of a pressure-induced phase change at a stress commensurate with that observed statically. It is shown that convergence between analytic derivations of release wave speed and the data requires the phase II to III transition to occur. Taylor impact is an integrated test that highlights continuum behavior that has origin in mesoscale response. There is a rapid transition from ductile to brittle behavior observed that occurs at a pressure consistent with this phase transition.

Ethnicity and Postmigration Health Trajectory in New Immigrants to Canada

PubMed Central

Kim, Il-Ho; Carrasco, Christine; Muntaner, Carles; McKenzie, Kwame

2013-01-01

Objectives. In this prospective cohort study, we examined the trajectory of general health during the first 4 years after new immigrants’ arrival in Canada. We focused on the change in self-rated health trajectories and their gender and ethnic disparities. Methods. Data were derived from the Longitudinal Survey of Immigrants to Canada and were collected between April 2001 and November 2005 by Statistics Canada. We used weighted samples of 3309 men and 3351 women aged between 20 and 59 years. Results. At arrival, only 3.5% of new immigrants rated their general health as poor. Significant and steady increases in poor health were revealed during the following 4 years, especially among ethnic minorities and women. Specifically, we found a higher risk of poor health among West Asian and Chinese men and among South Asian and Chinese women than among their European counterparts. Conclusions. Newly arrived immigrants are extremely healthy, but the health advantage dissipates rapidly during the initial years of settlement in Canada. Women and minority ethnic groups may be more vulnerable to social changes and postmigration settlement. PMID:23409893

Extreme Vertical Gusts in the Atmospheric Boundary Layer

DTIC Science & Technology

2015-07-01

significant effect on the statistics of the rare, extreme gusts. In the lowest 5,000 ft, boundary layer effects make small to moderate vertical...4 2.4 Effects of Gust Shape ............................................................................................... 5... Definitions Adiabatic Lapse Rate The rate of change of temperature with altitude that would occur if a parcel of air was transported sufficiently

An analytic data analysis method for oscillatory slug tests.

PubMed

Chen, Chia-Shyun

2006-01-01

An analytical data analysis method is developed for slug tests in partially penetrating wells in confined or unconfined aquifers of high hydraulic conductivity. As adapted from the van der Kamp method, the determination of the hydraulic conductivity is based on the occurrence times and the displacements of the extreme points measured from the oscillatory data and their theoretical counterparts available in the literature. This method is applied to two sets of slug test response data presented by Butler et al.: one set shows slow damping with seven discernable extremities, and the other shows rapid damping with three extreme points. The estimates of the hydraulic conductivity obtained by the analytic method are in good agreement with those determined by an available curve-matching technique.

Rapid Characterization of Microorganisms by Mass Spectrometry—What Can Be Learned and How?

NASA Astrophysics Data System (ADS)

Fenselau, Catherine C.

2013-08-01

Strategies for the rapid and reliable analysis of microorganisms have been sought to meet national needs in defense, homeland security, space exploration, food and water safety, and clinical diagnosis. Mass spectrometry has long been a candidate technique because it is extremely rapid and can provide highly specific information. It has excellent sensitivity. Molecular and fragment ion masses provide detailed fingerprints, which can also be interpreted. Mass spectrometry is also a broad band method—everything has a mass—and it is automatable. Mass spectrometry is a physiochemical method that is orthogonal and complementary to biochemical and morphological methods used to characterize microorganisms.

Rapid characterization of microorganisms by mass spectrometry--what can be learned and how?

PubMed

Fenselau, Catherine C

2013-08-01

Strategies for the rapid and reliable analysis of microorganisms have been sought to meet national needs in defense, homeland security, space exploration, food and water safety, and clinical diagnosis. Mass spectrometry has long been a candidate technique because it is extremely rapid and can provide highly specific information. It has excellent sensitivity. Molecular and fragment ion masses provide detailed fingerprints, which can also be interpreted. Mass spectrometry is also a broad band method--everything has a mass--and it is automatable. Mass spectrometry is a physiochemical method that is orthogonal and complementary to biochemical and morphological methods used to characterize microorganisms.

[Advances in medical care for extremely low birth weight infants worldwide].

PubMed

Chen, Chun; Zhang, Qian-Shen

2013-08-01

Dramatic advances in neonatal medicine over recent decades have resulted in decreased mortality and morbidity rates for extremely low birth weight infants. However, the survival of these infants is associated with short- and long-term morbidity, including severe intraventricular hemorrhage, periventricular leukomalacia, nosocomial infection and necrotizing enterocolitis, bronchopulmonary dysplasia, retinopathy of prematurity and adverse long-term neurodevelopmental sequelae. This article reviewed the latest advances in the medical care for extremely low birth weight infants including survival rate, ethical issues and short- and long-term morbidity, domestically and abroad.

A Versatile Room-Temperature Route to Di- and Trisubstituted Allenes Using Flow-Generated Diazo Compounds**

PubMed Central

Poh, Jian-Siang; Tran, Duc N; Battilocchio, Claudio; Hawkins, Joel M; Ley, Steven V

2015-01-01

A copper-catalyzed coupling reaction between flow-generated unstabilized diazo compounds and terminal alkynes provides di- and trisubstituted allenes. This extremely mild and rapid transformation is highly tolerant of several functional groups. PMID:26013774

Experiences with Extreme Programming

ERIC Educational Resources Information Center

Sherrell, Linda; Krishna, Bhagavathy; Velaga, Natasha; Vejandla, Pavan; Satharla, Mahesh

2010-01-01

Agile methodologies have become increasingly popular among software developers as evidenced by industrial participation at related conferences. The popularity of agile practices over traditional techniques partly stems from the fact that these practices provide for more customer involvement and better accommodate rapidly changing requirements,…

The Arctic Coastal Erosion Problem

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

Frederick, Jennifer M.; Thomas, Matthew Anthony; Bull, Diana L.

Permafrost-dominated coastlines in the Arctic are rapidly disappearing. Arctic coastal erosion rates in the United States have doubled since the middle of the twentieth century and appear to be accelerating. Positive erosion trends have been observed for highly-variable geomorphic conditions across the entire Arctic, suggesting a major (human-timescale) shift in coastal landscape evolution. Unfortunately, irreversible coastal land loss in this region poses a threat to native, industrial, scientific, and military communities. The Arctic coastline is vast, spanning more than 100,000 km across eight nations, ten percent of which is overseen by the United States. Much of area is inaccessible bymore » all-season roads. People and infrastructure, therefore, are commonly located near the coast. The impact of the Arctic coastal erosion problem is widespread. Homes are being lost. Residents are being dispersed and their villages relocated. Shoreline fuel storage and delivery systems are at greater risk. The U.S. Department of Energy (DOE) and Sandia National Laboratories (SNL) operate research facilities along some of the most rapidly eroding sections of coast in the world. The U.S. Department of Defense (DOD) is struggling to fortify coastal radar sites, operated to ensure national sovereignty in the air, against the erosion problem. Rapid alterations to the Arctic coastline are facilitated by oceanographic and geomorphic perturbations associated with climate change. Sea ice extent is declining, sea level is rising, sea water temperature is increasing, and permafrost state is changing. The polar orientation of the Arctic exacerbates the magnitude and rate of the environmental forcings that facilitate coastal land area loss. The fundamental mechanics of these processes are understood; their non-linear combination poses an extreme hazard. Tools to accurately predict Arctic coastal erosion do not exist. To obtain an accurate predictive model, a coupling of the influences of evolving wave dynamics, thermodynamics, and sediment dynamics must be developed. The objective of this document is to present the state-of-the-science and outline the key steps for creation of a framework that will allow for improved prediction of Arctic coastal erosion rates. This is the first step towards the quantification of coastal hazards that will allow for sustainable planning and development of Arctic infrastructure.« less

Population pharmacokinetics of intramuscular droperidol in acutely agitated patients

PubMed Central

Foo, Lee‐Kien; Duffull, Stephen B.; Calver, Leonie; Schneider, Jennifer

2016-01-01

Background Intramuscular droperidol is used increasingly for sedation of aggressive and violent patients. This study aimed to characterise the pharmacokinetics of intramuscular droperidol in these patients to determine how rapidly it is absorbed and the expected duration of measurable drug concentrations. Methods We undertook a population pharmacokinetic analysis of a subgroup of patients from a clinical trial comparing droperidol and midazolam: 17 receiving 5 mg and 24 receiving 10 mg droperidol. Droperidol was measured using high‐performance liquid chromatography. Pharmacokinetic modelling was performed under a nonlinear mixed effects modelling framework (NONMEM v7.2). The model was used to simulate concentration time profiles of three typical doses, 5 mg, 10 mg and 10 mg + 10 mg repeated at 15 min. Results A two‐compartment first‐order input with first‐order output model fitted the data best. The absorption rate constant was poorly characterised by the data and an estimate of the first order rate constant of absorption when fixed to 10 h–1 provided a stable model and lowest objective function. This represents extremely rapid absorption with a half‐life of 5 min. The final model had a clearance of 41.9 l h–1 and volume of distribution of the central compartment of, 73.6 l. Median and interquartile range of initial (alpha) half‐life was 0.32 h (0.26–0.37 h) and second (beta) half‐life was 3.0 h (2.5–3.6 h). Simulations indicate that 10 mg alone provides an 80% probability of being above the lower limit of quantification (5 μg l–1) for 7 h, 2 h longer than for 5 mg. Giving two 10 mg doses increased this duration to 10 h. Conclusions Intramuscular droperidol is rapidly absorbed with high therapeutic concentrations after 5 and 10 mg doses, and supports clinical data in which droperidol sedates rapidly for up to 6 h. PMID:27530285

Rapid Automated Aircraft Simulation Model Updating from Flight Data

NASA Technical Reports Server (NTRS)

Brian, Geoff; Morelli, Eugene A.

2011-01-01

Techniques to identify aircraft aerodynamic characteristics from flight measurements and compute corrections to an existing simulation model of a research aircraft were investigated. The purpose of the research was to develop a process enabling rapid automated updating of aircraft simulation models using flight data and apply this capability to all flight regimes, including flight envelope extremes. The process presented has the potential to improve the efficiency of envelope expansion flight testing, revision of control system properties, and the development of high-fidelity simulators for pilot training.

A fibre based triature interferometer for measuring rapidly evolving, ablatively driven plasma densities

NASA Astrophysics Data System (ADS)

Macdonald, J.; Bland, S. N.; Threadgold, J.

2015-08-01

We report on the first use of a fibre interferometer incorporating triature analysis for measuring rapidly evolving plasma densities of ne ˜ 1013/cm3 and above, such as those produced by simple coaxial plasma guns. The resultant system is extremely portable, easy to field in experiments, relatively cheap to produce, and—with the exception of a small open area in which the plasma is sampled—safe in operation as all laser light is enclosed.

Evaluation of the Efficacy of the Stress Protein Response as a Biochemical Water Quality Biomonitoring Method

DTIC Science & Technology

1990-12-21

Crawshaw , 1979; White, 1983; Lagerspetz, 1987). In fish under extreme thermal stress, regions of the brain appear to be the most sensitive, and...proteins. BioEssays 2: 48-52. CRAIG, E. A. 1989. Essential roles of 7OkDa heat inducible proteins. BioEssays 2: 48-52. CRAWSHAW , L.I. 1976. Effect of...rapid temperature change on mean body temperature and gill ventilation in carp. Amer. J. Physiol. 331: 837-841. CRAWSHAW , L. I. 1979. Responses to rapid

HEALTH STATUS OF EXTREMELY LOW BIRTH WEIGHT CHILDREN AT AGE 8 YEARS: CHILD AND PARENT PERSPECTIVE

PubMed Central

Hack, Maureen; Forrest, Christopher B; Schluchter, Mark; Taylor, H. Gerry; Drotar, Dennis; Holmbeck, Grayson; Andreias, Laura

2013-01-01

Context Parental proxy reports have indicated poorer health for preterm children as compared to normal birth weight controls. The perspective of their children may however differ. Objective To compare the self reported health of preterm children to normal birth weight controls and the children’s perspective to that of their parents. Design Study of extremely low birth weight (<1kg) and normal birth weight children and their parents conducted 2006–2009. Setting Children’s hospital. Participants Eight year old extremely low birth weight (n=202) and normal birth weight (n=176) children of similar sociodemographic status. Main Outcome Measures The Child Health and Illness Profile child and parent reports. Results There was poor agreement between the parent and child ratings of health for both the extremely low birth weight and normal birth weight cohorts. Extremely low birth weight children rated their health similar to normal birth weight children. In contrast parents of extremely low birth weight children reported significantly poorer health for their children than parents of normal birth weight controls including poorer Satisfaction with health, Comfort and Achievement and less Risk avoidance. Conclusion There is poor agreement between child and parent reports of health. Eight year old extremely low birth weight children rate their health similar to that of normal birth weight controls. Their parents however report significantly poorer health. Both child and parent perspective needs to be considered when making health care decisions. PMID:21969395

[Management of war orthopaedic injuries in recent armed conflicts].

PubMed

Frank, M; Mathieu, L

2013-01-01

The extremities continue to be the most frequent sites of wounding during armed conflicts despite the change of combat tactics, soldier armour and battlefield medical support. Due to the advances in prehospital care and timely transport to the hospital, orthopaedic surgeons deal with severe and challenging injuries of the limbs. In contrast to civilian extremity trauma, the most combat-related injuries are open wounds that often have infection-related complications. Data from two recent large armed conflicts (Iraq, Afghanistan) show that extremity injuries are associated with a high complication rate, morbidity and healthcare utilization. A systematic approach that consists of sequential surgical care and good transport capabilities can reduce the complication rate of these injuries. New medical technologies have been implemented in the treatment strategy during the last decade. This article reviews the published scientific data and current opinions on combat-related extremity injuries. Key words: extremity, combat, trauma, medical support system.

Ancestral genetic diversity associated with the rapid spread of stress-tolerant coral symbionts in response to Holocene climate change.

PubMed

Hume, Benjamin C C; Voolstra, Christian R; Arif, Chatchanit; D'Angelo, Cecilia; Burt, John A; Eyal, Gal; Loya, Yossi; Wiedenmann, Jörg

2016-04-19

Coral communities in the Persian/Arabian Gulf (PAG) withstand unusually high salinity levels and regular summer temperature maxima of up to ∼35 °C that kill conspecifics elsewhere. Due to the recent formation of the PAG and its subsequent shift to a hot climate, these corals have had only <6,000 y to adapt to these extreme conditions and can therefore inform on how coral reefs may respond to global warming. One key to coral survival in the world's warmest reefs are symbioses with a newly discovered alga,Symbiodinium thermophilum Currently, it is unknown whether this symbiont originated elsewhere or emerged from unexpectedly fast evolution catalyzed by the extreme environment. Analyzing genetic diversity of symbiotic algae across >5,000 km of the PAG, the Gulf of Oman, and the Red Sea coastline, we show thatS. thermophilumis a member of a highly diverse, ancient group of symbionts cryptically distributed outside the PAG. We argue that the adjustment to temperature extremes by PAG corals was facilitated by the positive selection of preadapted symbionts. Our findings suggest that maintaining the largest possible pool of potentially stress-tolerant genotypes by protecting existing biodiversity is crucial to promote rapid adaptation to present-day climate change, not only for coral reefs, but for ecosystems in general.

WHY ARE RAPIDLY ROTATING M DWARFS IN THE PLEIADES SO (INFRA)RED? NEW PERIOD MEASUREMENTS CONFIRM ROTATION-DEPENDENT COLOR OFFSETS FROM THE CLUSTER SEQUENCE

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

Covey, Kevin R.; Agüeros, Marcel A.; Liu, Jiyu

2016-05-10

Stellar rotation periods ( P {sub rot}) measured in open clusters have proved to be extremely useful for studying stars’ angular momentum content and rotationally driven magnetic activity, which are both age- and mass-dependent processes. While P {sub rot} measurements have been obtained for hundreds of solar-mass members of the Pleiades, measurements exist for only a few low-mass (<0.5 M {sub ⊙}) members of this key laboratory for stellar evolution theory. To fill this gap, we report P {sub rot} for 132 low-mass Pleiades members (including nearly 100 with M ≤ 0.45 M {sub ⊙}), measured from photometric monitoring ofmore » the cluster conducted by the Palomar Transient Factory in late 2011 and early 2012. These periods extend the portrait of stellar rotation at 125 Myr to the lowest-mass stars and re-establish the Pleiades as a key benchmark for models of the transport and evolution of stellar angular momentum. Combining our new P {sub rot} with precise BVIJHK photometry reported by Stauffer et al. and Kamai et al., we investigate known anomalies in the photometric properties of K and M Pleiades members. We confirm the correlation detected by Kamai et al. between a star's P {sub rot} and position relative to the main sequence in the cluster's color–magnitude diagram. We find that rapid rotators have redder ( V − K ) colors than slower rotators at the same V , indicating that rapid and slow rotators have different binary frequencies and/or photospheric properties. We find no difference in the photometric amplitudes of rapid and slow rotators, indicating that asymmetries in the longitudinal distribution of starspots do not scale grossly with rotation rate.« less

Recovery kinetics of photochemical efficiency in winter stressed conifers: the effects of growth light environment, extent of the season and species.

PubMed

Verhoeven, Amy S

2013-02-01

Evergreens undergo reductions in maximal photochemical efficiency (F(v)/F(m)) during winter due to increases in sustained thermal energy dissipation. Upon removing winter stressed leaves to room temperature and low light, F(v)/F(m) recovers and can include both a rapid and a slow phase. The goal of this study was to determine whether the rapid component to recovery exists in winter stressed conifers at any point during the season in a seasonally extreme environment. Additional goals were to compare the effects of species, growth light environment and the extent of the winter season on recovery kinetics in conifers. Four species (sun and shade needle) were monitored during the winter of 2007/2008: eastern white pine (Pinus strobus), balsam fir (Abies balsamea), Taxus cuspidata and white spruce (Picea glauca). F(v)/F(m) was measured in the field, and then monitored indoors at room temperature and low light for 6 days. The results showed that all species showed a rapid component to recovery in early winter that disappeared later in the season in sun needles but was present in shade needles on most days monitored during winter. There were differences among species in the recovery kinetics across the season, with pine recovering the most slowly and spruce the most quickly. The results suggest an important role for the rapidly reversible form of energy dissipation in early winter, as well as important differences between species in their rate of recovery in late winter/early spring which may have implications for spring onset of photosynthesis. Copyright © Physiologia Plantarum 2012.

RAPID Assessment of Extreme Reservoir Sedimentation Resulting from the September 2013 Flood, North St. Vrain Creek, CO

NASA Astrophysics Data System (ADS)

Rathburn, S. L.; McElroy, B. J.; Wohl, E.; Sutfin, N. A.; Huson, K.

2014-12-01

During mid-September 2013, approximately 360 mm of precipitation fell in the headwaters of the North St. Vrain drainage basin, Front Range, CO. Debris flows on steep hillslopes and extensive flooding along North St. Vrain Creek resulted in extreme sedimentation within Ralph Price Reservoir, municipal water supply for the City of Longmont. The event allows comparison of historical sedimentation with that of an unusually large flood because 1) no reservoir flushing has been conducted since dam construction, 2) reservoir stratigraphy chronicles uninterrupted delta deposition, and 3) this is the only on-channel reservoir with unimpeded, natural sediment flux from the Continental Divide to the mountain front in a basin with no significant historic flow modifications and land use impacts. Assessing the flood-related sedimentation prior to any dredging activities included coring the reservoir delta, a bathymetric survey of the delta, resistivity and ground penetrating radar surveys of the subaerial inlet deposit, and surveying tributary deposits. Over the 44-year life of the reservoir, two-thirds of the delta sedimentation is attributed to extreme discharges from the September 2013 storm. Total storm-derived reservoir sedimentation is approximately 275,000 m3, with 81% of that within the gravel-dominated inlet and 17% in the delta. Volumes of deposition within reservoir tributary inlets is negatively correlated with contributing area, possibly due to a lack of storage in these small basins (1-5 km2). Flood-related reservoir sedimentation will be compared to other research quantifying volumes from slope failures evident on post-storm lidar. Analysis of delta core samples will quantify organic carbon flux associated with the extreme discharge and develop a chronology of flood and fire disturbances for North St. Vrain basin. Applications of similar techniques are planned for two older Front Range reservoirs affected by the September flooding to fill knowledge gaps about event-based sedimentation and to expand these rates to annual and decadal scales.

Frequency analysis and its spatiotemporal characteristics of precipitation extreme events in China during 1951-2010

NASA Astrophysics Data System (ADS)

Shao, Yuehong; Wu, Junmei; Ye, Jinyin; Liu, Yonghe

2015-08-01

This study investigates frequency analysis and its spatiotemporal characteristics of precipitation extremes based on annual maximum of daily precipitation (AMP) data of 753 observation stations in China during the period 1951-2010. Several statistical methods including L-moments, Mann-Kendall test (MK test), Student's t test ( t test) and analysis of variance ( F-test) are used to study different statistical properties related to frequency and spatiotemporal characteristics of precipitation extremes. The results indicate that the AMP series of most sites have no linear trends at 90 % confidence level, but there is a distinctive decrease trend in Beijing-Tianjin-Tangshan region. The analysis of abrupt changes shows that there are no significant changes in most sites, and no distinctive regional patterns within the mutation sites either. An important innovation different from the previous studies is the shift in the mean and the variance which are also studied in this paper in order to further analyze the changes of strong and weak precipitation extreme events. The shift analysis shows that we should pay more attention to the drought in North China and to the flood control and drought in South China, especially to those regions that have no clear trend and have a significant shift in the variance. More important, this study conducts the comprehensive analysis of a complete set of quantile estimates and its spatiotemporal characteristic in China. Spatial distribution of quantile estimation based on the AMP series demonstrated that the values gradually increased from the Northwest to the Southeast with the increment of duration and return period, while the increasing rate of estimation is smooth in the arid and semiarid region and is rapid in humid region. Frequency estimates of 50-year return period are in agreement with the maximum observations of AMP series in the most stations, which can provide more quantitative and scientific basis for decision making.

Assessing sedimentation issues within aging flood-control reservoirs

USDA-ARS?s Scientific Manuscript database

Flood control reservoirs designed and built by federal agencies have been extremely effective in reducing the ravages of floods nationwide. Yet some structures are being removed for a variety of reasons, while other structures are aging rapidly and require either rehabilitation or decommissioning. ...

Historical Evolution of Old-Age Mortality and New Approaches to Mortality Forecasting

PubMed Central

Gavrilov, Leonid A.; Gavrilova, Natalia S.; Krut'ko, Vyacheslav N.

2017-01-01

Knowledge of future mortality levels and trends is important for actuarial practice but poses a challenge to actuaries and demographers. The Lee-Carter method, currently used for mortality forecasting, is based on the assumption that the historical evolution of mortality at all age groups is driven by one factor only. This approach cannot capture an additive manner of mortality decline observed before the 1960s. To overcome the limitation of the one-factor model of mortality and to determine the true number of factors underlying mortality changes over time, we suggest a new approach to mortality analysis and forecasting based on the method of latent variable analysis. The basic assumption of this approach is that most variation in mortality rates over time is a manifestation of a small number of latent variables, variation in which gives rise to the observed mortality patterns. To extract major components of mortality variation, we apply factor analysis to mortality changes in developed countries over the period of 1900–2014. Factor analysis of time series of age-specific death rates in 12 developed countries (data taken from the Human Mortality Database) identified two factors capable of explaining almost 94 to 99 percent of the variance in the temporal changes of adult death rates at ages 25 to 85 years. Analysis of these two factors reveals that the first factor is a “young-age” or background factor with high factor loadings at ages 30 to 45 years. The second factor can be called an “oldage” or senescent factor because of high factor loadings at ages 65 to 85 years. It was found that the senescent factor was relatively stable in the past but now is rapidly declining for both men and women. The decline of the senescent factor is faster for men, although in most countries, it started almost 30 years later. Factor analysis of time series of age-specific death rates conducted for the oldest-old ages (65 to 100 years) found two factors explaining variation of mortality at extremely old ages in the United States. The first factor is comparable to the senescent factor found for adult mortality. The second factor, however, is specific to extreme old ages (96 to 100 years) and shows peaks in 1960 and 2000. Although mortality below 90 to 95 years shows a steady decline with time driven by the senescent factor, mortality of centenarians does not decline and remains relatively stable. The approach suggested in this paper has several advantages. First, it is able to determine the total number of independent factors affecting mortality changes over time. Second, this approach allows researchers to determine the time interval in which underlying factors remain stable or undergo rapid changes. Most methods of mortality projections are not able to identify the best base period for mortality projections, attempting to use the longest-possible time period instead. We observe that the senescent factor of mortality continues to decline, and this decline does not demonstrate any indications of slowing down. At the same time, mortality of centenarians does not decline and remains stable. The lack of mortality decline at extremely old ages may diminish anticipated longevity gains in the future. PMID:29170765

Bipolar vulnerability and extreme appraisals of internal states: a computerized ratings study.

PubMed

Dodd, Alyson L; Mansell, Warren; Morrison, Anthony P; Tai, Sara

2011-01-01

A recent integrative cognitive model proposed that multiple, extreme, personalized, positive and negative appraisals of internal states predispose to maintain and exacerbate bipolar symptoms. This study aimed to directly assess conviction in a range of positive and negative appraisals of internal states suggested by the model, by using a laboratory-based computerized task. In a student sample (n = 68), a history of hypomania was associated with more positive and less negative appraisals of internal states, and a history of depression was associated with more negative appraisals and less positive appraisals of internal states. The sample was then split into three groups for comparison: bipolar risk (n = 18), depression risk (n = 20) and controls (n  = 30). Relative to controls, the bipolar risk group made more extreme ratings of catastrophic appraisals of low activation states and tended to make more extreme ratings of appraisals of high activation states. The depression risk group scored higher on a range of negative appraisals of low activation states. These findings provide tentative support for the role of both positive and negative, extreme, personalized appraisals of internal states in hypomania and depression. Copyright © 2011 John Wiley & Sons, Ltd.

Predictors of Upper-Extremity Physical Function in Older Adults.

PubMed

Hermanussen, Hugo H; Menendez, Mariano E; Chen, Neal C; Ring, David; Vranceanu, Ana-Maria

2016-10-01

Little is known about the influence of habitual participation in physical exercise and diet on upper-extremity physical function in older adults. To assess the relationship of general physical exercise and diet to upper-extremity physical function and pain intensity in older adults. A cohort of 111 patients 50 or older completed a sociodemographic survey, the Rapid Assessment of Physical Activity (RAPA), an 11-point ordinal pain intensity scale, a Mediterranean diet questionnaire, and three Patient- Reported Outcomes Measurement Information System (PROMIS) based questionnaires: Pain Interference to measure inability to engage in activities due to pain, Upper-Extremity Physical Function, and Depression. Multivariable linear regression modeling was used to characterize the association of physical activity, diet, depression, and pain interference to pain intensity and upper-extremity function. Higher general physical activity was associated with higher PROMIS Upper-Extremity Physical Function and lower pain intensity in bivariate analyses. Adherence to the Mediterranean diet did not correlate with PROMIS Upper-Extremity Physical Function or pain intensity in bivariate analysis. In multivariable analyses factors associated with higher PROMIS Upper-Extremity Physical Function were male sex, non-traumatic diagnosis and PROMIS Pain Interference, with the latter accounting for most of the observed variability (37%). Factors associated with greater pain intensity in multivariable analyses included fewer years of education and higher PROMIS Pain Interference. General physical activity and diet do not seem to be as strongly or directly associated with upper-extremity physical function as pain interference.

Life extension of self-healing polymers with rapidly growing fatigue cracks.

PubMed

Jones, A S; Rule, J D; Moore, J S; Sottos, N R; White, S R

2007-04-22

Self-healing polymers, based on microencapsulated dicyclopentadiene and Grubbs' catalyst embedded in the polymer matrix, are capable of responding to propagating fatigue cracks by autonomic processes that lead to higher endurance limits and life extension, or even the complete arrest of the crack growth. The amount of fatigue-life extension depends on the relative magnitude of the mechanical kinetics of crack propagation and the chemical kinetics of healing. As the healing kinetics are accelerated, greater fatigue life extension is achieved. The use of wax-protected, recrystallized Grubbs' catalyst leads to a fourfold increase in the rate of polymerization of bulk dicyclopentadiene and extends the fatigue life of a polymer specimen over 30 times longer than a comparable non-healing specimen. The fatigue life of polymers under extremely fast fatigue crack growth can be extended through the incorporation of periodic rest periods, effectively training the self-healing polymeric material to achieve higher endurance limits.

Direct Analysis of Organic Compounds in Liquid Using a Miniature Photoionization Ion Trap Mass Spectrometer with Pulsed Carrier-Gas Capillary Inlet.

PubMed

Lu, Xinqiong; Yu, Quan; Zhang, Qian; Ni, Kai; Qian, Xiang; Tang, Fei; Wang, Xiaohao

2017-08-01

A miniature ion trap mass spectrometer with capillary direct sampling and vacuum ultraviolet photoionization source was developed to conduct trace analysis of organic compounds in liquids. Self-aspiration sampling is available where the samples are drawn into the vacuum chamber through a capillary with an extremely low flow rate (less than 1 μL/min), which minimizes sample consumption in each analysis to tens of micrograms. A pulsed gas-assisted inlet was designed and optimized to promote sample transmission in the tube and facilitate the cooling of ions, thereby improving instrument sensitivity. A limit of detection of 2 ppb could be achieved for 2,4-dimethylaniline in a methanol solution. The sampling system described in the present study is specifically suitable for a miniature photoionization ion trap mass spectrometer that can perform rapid and online analysis for liquid samples. Graphical Abstract ᅟ.

Mechanical properties of ultrahigh molecular weight PHEMA hydrogels synthesized using initiated chemical vapor deposition.

PubMed

Bose, Ranjita K; Lau, Kenneth K S

2010-08-09

In this work, poly(2-hydroxyethyl methacrylate) (PHEMA), a widely used hydrogel, is synthesized using initiated chemical vapor deposition (iCVD), a one-step surface polymerization that does not use any solvents. iCVD synthesis is capable of producing linear stoichiometric polymers that are free from entrained unreacted monomer or solvent and, thus, do not require additional purification steps. The resulting films, therefore, are found to be noncytotoxic and also have low nonspecific protein adsorption. The kinetics of iCVD polymerization are tuned so as to achieve rapid deposition rates ( approximately 1.5 microm/min), which in turn yield ultrahigh molecular weight polymer films that are mechanically robust with good water transport and swellability. The films have an extremely high degree of physical chain entanglement giving rise to high tensile modulus and storage modulus without the need for chemical cross-linking that compromises hydrophilicity.

Direct Analysis of Organic Compounds in Liquid Using a Miniature Photoionization Ion Trap Mass Spectrometer with Pulsed Carrier-Gas Capillary Inlet

NASA Astrophysics Data System (ADS)

Lu, Xinqiong; Yu, Quan; Zhang, Qian; Ni, Kai; Qian, Xiang; Tang, Fei; Wang, Xiaohao

2017-08-01

A miniature ion trap mass spectrometer with capillary direct sampling and vacuum ultraviolet photoionization source was developed to conduct trace analysis of organic compounds in liquids. Self-aspiration sampling is available where the samples are drawn into the vacuum chamber through a capillary with an extremely low flow rate (less than 1 μL/min), which minimizes sample consumption in each analysis to tens of micrograms. A pulsed gas-assisted inlet was designed and optimized to promote sample transmission in the tube and facilitate the cooling of ions, thereby improving instrument sensitivity. A limit of detection of 2 ppb could be achieved for 2,4-dimethylaniline in a methanol solution. The sampling system described in the present study is specifically suitable for a miniature photoionization ion trap mass spectrometer that can perform rapid and online analysis for liquid samples.

Rapid, Long-Distance Dispersal by Pumice Rafting

PubMed Central

Bryan, Scott E.; Cook, Alex G.; Evans, Jason P.; Hebden, Kerry; Hurrey, Lucy; Colls, Peter; Jell, John S.; Weatherley, Dion; Firn, Jennifer

2012-01-01

Pumice is an extremely effective rafting agent that can dramatically increase the dispersal range of a variety of marine organisms and connect isolated shallow marine and coastal ecosystems. Here we report on a significant recent pumice rafting and long-distance dispersal event that occurred across the southwest Pacific following the 2006 explosive eruption of Home Reef Volcano in Tonga. We have constrained the trajectory, and rate, biomass and biodiversity of transfer, discovering more than 80 species and a substantial biomass underwent a >5000 km journey in 7–8 months. Differing microenvironmental conditions on the pumice, caused by relative stability of clasts at the sea surface, promoted diversity in biotic recruitment. Our findings emphasise pumice rafting as an important process facilitating the distribution of marine life, which have implications for colonisation processes and success, the management of sensitive marine environments, and invasive pest species. PMID:22815770

Bayes plus Brass: Estimating Total Fertility for Many Small Areas from Sparse Census Data

PubMed Central

Schmertmann, Carl P.; Cavenaghi, Suzana M.; Assunção, Renato M.; Potter, Joseph E.

2013-01-01

Small-area fertility estimates are valuable for analysing demographic change, and important for local planning and population projection. In countries lacking complete vital registration, however, small-area estimates are possible only from sparse survey or census data that are potentially unreliable. Such estimation requires new methods for old problems: procedures must be automated if thousands of estimates are required, they must deal with extreme sampling variability in many areas, and they should also incorporate corrections for possible data errors. We present a two-step algorithm for estimating total fertility in such circumstances, and we illustrate by applying the method to 2000 Brazilian Census data for over five thousand municipalities. Our proposed algorithm first smoothes local age-specific rates using Empirical Bayes methods, and then applies a new variant of Brass’s P/F parity correction procedure that is robust under conditions of rapid fertility decline. PMID:24143946

[Nursing motivation leadership].

PubMed

Chen, Ia-Ling; Hung, Chich-Hsiu

2007-02-01

The concept of "patients treated as guests" is emphasized in today's medical service and patient-center nursing care. However, with rapid changes in health insurance and hospital accreditation systems as well as increasing consumer awareness, the nurse manager must both efficiently relieve the working pressure of nurses and motivate them. However, it would be an extreme challenge for nurse managers to build a team in which each member works in a self-fulfilling work environment and achieves a high quality of care. This article presents several theories and techniques that relate to motivation strategies. These strategies can serve as a guide and a reference for nurse managers to inspire teamwork and raise morale. It can be expected that increasing nurse satisfaction, performance, and care quality will decrease turnover and desertion rates. Hopefully, this article will assist nurse managers to become better leaders and to achieve success in providing efficient services and good of nursing care quality.

Stratospheric aerosol geoengineering

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

Robock, Alan

2015-03-30

The Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, has found that insolation reduction could keep the global average temperature constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform; the tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without geoengineering. If geoengineering were halted all at once, there would be rapid temperature and precipitation increases at 5–10 times the rates frommore » gradual global warming. The prospect of geoengineering working may reduce the current drive toward reducing greenhouse gas emissions, and there are concerns about commercial or military control. Because geoengineering cannot safely address climate change, global efforts to reduce greenhouse gas emissions and to adapt are crucial to address anthropogenic global warming.« less

Quantifying the Influence of Climate on Human Conflict

NASA Astrophysics Data System (ADS)

Hsiang, S. M.; Burke, M.; Miguel, E.

2014-12-01

A rapidly growing body of research examines whether human conflict can be affected by climatic changes. Drawing from archaeology, criminology, economics, geography, history, political science, and psychology, we assemble and analyze the most rigorous quantitative studies and document, for the first time, a striking convergence of results. We find strong causal evidence linking climatic events to human conflict across a range of spatial and temporal scales and across all major regions of the world. The magnitude of climate's influence is substantial: for each one standard deviation (1sd) change in climate toward warmer temperatures or more extreme rainfall, median estimates indicate that the frequency of interpersonal violence rises 4% and the frequency of intergroup conflict rises 14%. Because locations throughout the inhabited world are expected to warm 2sd to 4sd by 2050, amplified rates of human conflict could represent a large and critical impact of anthropogenic climate change.

The Causes and Consequences of Changes in Virulence following Pathogen Host Shifts

PubMed Central

Longdon, Ben; Hadfield, Jarrod D.; Day, Jonathan P.; Smith, Sophia C. L.; McGonigle, John E.; Cogni, Rodrigo; Cao, Chuan; Jiggins, Francis M.

2015-01-01

Emerging infectious diseases are often the result of a host shift, where the pathogen originates from a different host species. Virulence—the harm a pathogen does to its host—can be extremely high following a host shift (for example Ebola, HIV, and SARs), while other host shifts may go undetected as they cause few symptoms in the new host. Here we examine how virulence varies across host species by carrying out a large cross infection experiment using 48 species of Drosophilidae and an RNA virus. Host shifts resulted in dramatic variation in virulence, with benign infections in some species and rapid death in others. The change in virulence was highly predictable from the host phylogeny, with hosts clustering together in distinct clades displaying high or low virulence. High levels of virulence are associated with high viral loads, and this may determine the transmission rate of the virus. PMID:25774803

Dark energy from the motions of neutrinos

NASA Astrophysics Data System (ADS)

Simpson, Fergus; Jimenez, Raul; Pena-Garay, Carlos; Verde, Licia

2018-06-01

Ordinarily, a scalar field may only play the role of dark energy if it possesses a potential that is either extraordinarily flat or extremely fine-tuned. Here we demonstrate that these restrictions are lifted when the scalar field undergoes persistent energy exchange with another fluid. In this scenario, the field is prevented from reversing its direction of motion, and instead may come to rest while displaced from the local minimum of its potential. Therefore almost any scalar potential is capable of initiating a prolonged phase of cosmic acceleration. If the rate of energy transfer is modulated via a derivative coupling, the field undergoes a rapid process of freezing, after which the field's equation of state mimicks that of a cosmological constant. We present a physically motivated realisation in the form of a neutrino-majoron coupling, which avoids the dynamical instabilities associated with mass-varying neutrino models. Finally we discuss possible means by which this model could be experimentally verified.

‘Leave Your Ego at the Door’: A Narrative Investigation into Effective Wingsuit Flying

PubMed Central

Arijs, Cedric; Chroni, Stiliani; Brymer, Eric; Carless, David

2017-01-01

In recent years there has been a rapid growth in interest in extreme sports. For the most part research has focused on understanding motivations for participation in extreme sports and very little research has attempted to investigate the psychological structure of effective performance. Those few studies that have attempted to explore this issue have tested models designed for traditional sport on adventure sports. However, extreme sports are not the same as adventure sports or traditional sports. This study employed a narrative approach to investigate experiences of effective performance in the extreme sport of proximity wingsuit flying. An overarching theme we labeled ‘leave your ego at the door,’ emerged based on four sub-themes: (1) know thy self, (2) know thy skills, (3) know the environment now, and (4) tame the ‘inner animal.’ These themes are presented and discussed in relation to performance and discovery narratives identified within elite sport, thereby shedding light on how participants’ experiences of the extreme sport of proximity wingsuit flying differ from dominant stories within traditional sports. PMID:29204131

Impacts of heat waves with or without drought - immediate responses and legacy effects in temperate and alpine grassland

NASA Astrophysics Data System (ADS)

De Boeck, H. J.

2017-12-01

Climate change is rapidly increasing both the frequency and intensity of weather extremes such as drought spells and heat waves. Moreover, drought and heat are often coupled, and the compound effects can often not be readily derived from observations of the single-factor impacts. We here present results from experiments carried out in two distinct types of grassland, temperate and alpine, and look into both immediate and after-effects of droughts and heat waves as single factors or in conjunction. Perhaps surprisingly, both ecosystems responded very similarly in the short term (i.e. during the extreme): heat waves only caused significant physiological stress leading to senescence and productivity declines if soil water was in short supply. Warmer conditions led to faster and more intense drying, which in turn increased tissue temperatures as stomatal conductance and therefore heat dissipation decreased. The after-effects diverged significantly between the two grassland types though: whereas temperate grassland was characterised by rapid recovery and no major shifts in community composition and diversity, the harshest extremes had a more lasting impact in alpine grassland. There, it took two growing seasons for biomass production to recover, while vegetation cover was still reduced at that time. Furthermore, functional group composition had shifted, with a higher fraction of graminoid versus herbaceous species and lower overall species richness. This research demonstrates that impacts of extreme weather events can be very different when considering single-factor versus interacting events, and that similar initial responses in different ecosystems may not hold in the longer term.

Shoulder injuries from alpine skiing and snowboarding. Aetiology, treatment and prevention.

PubMed

Kocher, M S; Dupré, M M; Feagin, J A

1998-03-01

There has been a decrease in the overall injury rate and the rate of lower extremity injuries for alpine skiing, with a resultant increase in the ratio of upper extremity to lower extremity injuries. Upper extremity injuries account for 20 to 35% of all injuries during alpine skiing and nearly 50% of all injuries during snowboarding. The most common upper extremity injuries during skiing are sprain of the thumb metacarpal-phalangeal joint ulnar collateral ligament, and the most common in snowboarding is wrist fracture. Shoulder injuries from skiing and snowboarding have been less well characterised. With the increased ratio of upper to lower extremity injuries during alpine skiing and the boom in popularity of snowboarding, shoulder injuries will be seen with increasing frequency by those who care for alpine sport injuries. Shoulder injuries account for 4 to 11% of all alpine skiing injuries and 22 to 41% of upper extremity injuries. The rate of shoulder injuries during alpine skiing is 0.2 to 0.5 injuries per thousand skier-days. During snowboarding, shoulder injuries account for 8 to 16% of all injuries and 20 to 34% of upper extremity injuries. Falls are the most common mechanism of shoulder injury, in addition to pole planting during skiing and aerial manoeuvres during snowboarding. Common shoulder injuries during skiing and snowboarding are glenohumeral instability, rotator cuff strains, acromioclavicular separations and clavicle fractures. Less common shoulder injuries include greater tuberosity fractures, trapezius strains, proximal humerus fractures, biceps strains, glenoid fractures, scapula fractures, humeral head fractures, sterno-clavicular separations, acromion fractures and biceps tendon dislocation. Prevention of shoulder injuries during skiing and snowboarding may be possible through interventions in education and technique, conditioning and equipment and environment.

Evaporation variability of Nam Co Lake in the Tibetan Plateau and its role in recent rapid lake expansion

NASA Astrophysics Data System (ADS)

Ma, Ning; Szilagyi, Jozsef; Niu, Guo-Yue; Zhang, Yinsheng; Zhang, Teng; Wang, Binbin; Wu, Yanhong

2016-06-01

Previous studies have shown that the majority of the lakes in the Tibetan Plateau (TP) started to expand rapidly since the late 1990s. However, the causes are still not well known. For Nam Co, being a closed lake with no outflow, evaporation (EL) over the lake surface is the only way water may leave the lake. Therefore, quantifying EL is key for investigating the mechanism of lake expansion in the TP. EL can be quantified by Penman- and/or bulk-transfer-type models, requiring only net radiation, temperature, humidity and wind speed for inputs. However, interpolation of wind speed data may be laden with great uncertainty due to extremely sparse ground meteorological observations, the highly heterogeneous landscape and lake-land breeze effects. Here, evaporation of Nam Co Lake was investigated within the 1979-2012 period at a monthly time-scale using the complementary relationship lake evaporation (CRLE) model which does not require wind speed data. Validations by in-situ observations of E601B pan evaporation rates at the shore of Nam Co Lake as well as measured EL over an adjacent small lake using eddy covariance technique suggest that CRLE is capable of simulating EL well since it implicitly considers wind effects on evaporation via its vapor transfer coefficient. The multi-year average of annual evaporation of Nam Co Lake is 635 mm. From 1979 to 2012, annual evaporation of Nam Co Lake expressed a very slight decreasing trend. However, a more significant decrease in EL occurred during 1998-2008 at a rate of -12 mm yr-1. Based on water-level readings, this significant decrease in lake evaporation was found to be responsible for approximately 4% of the reported rapid water level increase and areal expansion of Nam Co Lake during the same period.

Mechanical Testing of PMCs under Simulated Rapid Heat-Up Propulsion Environments. II; In-Plane Compressive Behavior

NASA Technical Reports Server (NTRS)

Stokes, Eric H.; Shin, E. Eugene; Sutter, James K.

2003-01-01

Carbon fiber thermoset polymer matrix composites (PMC) with high temperature polyimide based in-situ polymerized monomer reactant (PMR) resin has been used for some time in applications which can see temperatures up to 550 F. Currently, graphite fiber PMR based composites are used in several aircraft engine components including the outer bypass duct for the GE F-404, exit flaps for the P&W F-100-229, and the core cowl for the GE/Snecma CF6-80A3. Newer formulations, including PMR-II-50 are being investigated as potential weight reduction replacements of various metallic components in next generation high performance propulsion rocket engines that can see temperatures which exceed 550 F. Extensive FEM thermal modeling indicates that these components are exposed to rapid heat-up rates (up to -200 F/sec) and to a maximum temperature of around 600 F. Even though the predicted maximum part temperatures were within the capability of PW-II-50, the rapid heat-up causes significant through-thickness thermal gradients in the composite part and even more unstable states when combined with moisture. Designing composite parts for such extreme service environments will require accurate measurement of intrinsic and transient mechanical properties and the hygrothermal performance of these materials under more realistic use conditions. The mechanical properties of polymers degrade when exposed to elevated temperatures even in the absence of gaseous oxygen. Accurate mechanical characterization of the material is necessary in order to reduce system weight while providing sufficient factors of safety. Historically, the testing of PMCs at elevated temperatures has been plagued by the antagonism between two factors. First, moisture has been shown to profoundly affect the mechanical response of these materials at temperatures above their glass transition temperature while concurrently lowering the material's Tg. Moisture phenomena is due to one or a combination of three effects, i.e., plastization of polymeric material by water, the internal pressure generated by the volatilization of water at elevated temperatures, and hydrolytic chemical decomposition. However, moisture is lost from the material at increasing rates as temperature increases. Second, because PMCs are good thermal insulators, when they are externally heated at even mild rates large thermal gradients can develop within the material. At temperatures where a material property changes rapidly with temperature the presence of a large thermal gradient is unacceptable for intrinsic property characterization purposes. Therefore, long hold times are required to establish isothermal conditions. However, in the service environments high-heating-rates, high temperatures, high-loading rates are simultaneous present along with residual moisture. In order to capture the effects of moisture on the material, holding at- temperature until isothermal conditions are reached is unacceptable particularly in materials with small physical dimensions. Thus, the effects due to moisture on the composite's mechanical characteristics, ie., their so-called analog response, may be instructive. One approach employed in this program was rapid heat-up (approx. 200 F/sec.) and loading of both dry and wet in-plane compressive specimens to examine the effects of moisture on this resin dominated mechanical property of the material.

Factors Effecting the Fate and Transport of CL-20 in the Vadose Zone and Groundwater: Final Report 2002 - 2004 SERDP Project CP-1255

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

Szecsody, James E.; Riley, Robert G.; Devary, Brooks J.

2005-06-01

This SERDP-funded project was initiated to investigate the fate of CL-20 in the subsurface environment, with a focus on identification and quantification of geochemical and microbial reactions of CL-20. CL-20 can be released to the surface and subsurface terrestrial environment by: a) manufacturing processes, b) munition storage, and c) use with low order detonation or unexploded ordnance. The risk of far-field subsurface migration was assessed through labora-tory experiments with a variety of sediments and subsurface materials to quantify processes that control CL-20 sorption-limited migration and degradation. Results of this study show that CL-20 will exhibit differing behavior in the subsurfacemore » terrestrial environment: 1. CL-20 on the sediment surface will photodegrade and interact with plants/animals (described in other SERDP projects CU 1254, 1256). CL-20 will exhibit greater sorption in humid sediments to organic matter. Transport will be solubility limited (i.e., low CL-20 aqueous solubility). 2. CL-20 infiltration into soils (<2 m) from spills will be subject to sorption to soil organic matter (if present), and low to high biodegradation rates (weeks to years) depending on the microbial population (greater in humid environment). 3. CL-20 in the vadose zone (>2 m) will be, in most cases, subject to low sorption and low degradation rates, so would persist in the subsurface environment and be at risk for deep migration. Low water content in arid regions will result in a decrease in both sorption and the degradation rate. Measured degradation rates in unsaturated sediments of years would result in significant subsurface migration distances. 4. CL-20 in groundwater will be subject to some sorption but likely very slow degradation rates. CL-20 sorption will be greater than RDX. Most CL-20 degradation will be abiotic (ferrous iron and other transition metals), because most deep subsurface systems have extremely low natural microbial populations. Degradation rates will range from weeks (iron reducing systems) to years. Although CL-20 will move rapidly through most sediments in the terrestrial environment, subsurface remediation can be utilized for cleanup. Transformation of CL-20 to intermediates can be rapidly accomplished under: a) reducing conditions (CL-20 4.1 min. half-life, RDX 18 min. half-life), b) alkaline (pH >10) conditions, and c) bioremediation with added nutrients. CL-20 degradation to intermediates may be insufficient to mitigate environmental impact, as the toxicity of many of these compounds is unknown. Biostimulation in oxic to reducing systems by carbon and nutrient addition can mineralize CL-20, with the most rapid rates occurring under reducing conditions.« less

Rapid and repeated origin of insular gigantism and dwarfism in Australian tiger snakes.

PubMed

Keogh, J Scott; Scott, Ian A W; Hayes, Christine

2005-01-01

It is a well-known phenomenon that islands can support populations of gigantic or dwarf forms of mainland conspecifics, but the variety of explanatory hypotheses for this phenomenon have been difficult to disentangle. The highly venomous Australian tiger snakes (genus Notechis) represent a well-known and extreme example of insular body size variation. They are of special interest because there are multiple populations of dwarfs and giants and the age of the islands and thus the age of the tiger snake populations are known from detailed sea level studies. Most are 5000-7000 years old and all are less than 10,000 years old. Here we discriminate between two competing hypotheses with a molecular phylogeography dataset comprising approximately 4800 bp of mtDNA and demonstrate that populations of island dwarfs and giants have evolved five times independently. In each case the closest relatives of the giant or dwarf populations are mainland tiger snakes, and in four of the five cases, the closest relatives are also the most geographically proximate mainland tiger snakes. Moreover, these body size shifts have evolved extremely rapidly and this is reflected in the genetic divergence between island body size variants and mainland snakes. Within south eastern Australia, where populations of island giants, populations of island dwarfs, and mainland tiger snakes all occur, the maximum genetic divergence is only 0.38%. Dwarf tiger snakes are restricted to prey items that are much smaller than the prey items of mainland tiger snakes and giant tiger snakes are restricted to seasonally available prey items that are up three times larger than the prey items of mainland tiger snakes. We support the hypotheses that these body size shifts are due to strong selection imposed by the size of available prey items, rather than shared evolutionary history, and our results are consistent with the notion that adaptive plasticity also has played an important role in body size shifts. We suggest that plasticity displayed early on in the occupation of these new islands provided the flexibility necessary as the island's available prey items became more depauperate, but once the size range of available prey items was reduced, strong natural selection followed by genetic assimilation worked to optimize snake body size. The rate of body size divergence in haldanes is similar for dwarfs (h(g) = 0.0010) and giants (h(g) = 0.0020-0.0025) and is in line with other studies of rapid evolution. Our data provide strong evidence for rapid and repeated morphological divergence in the wild due to similar selective pressures acting in different directions.

Rapid shallow breathing

MedlinePlus

Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Kraft M. Approach to the patient with respiratory disease. In: ... Elsevier Saunders; 2016:chap 83. McGee S. Respiratory rate and ...

The Determination Method of Extreme Earthquake Disaster Area Based on the Dust Detection Result from GF-4 Data

NASA Astrophysics Data System (ADS)

Dou, A.; Ding, L.; Chen, M.; Wang, X.

2018-04-01

The remote sensing has played an important role in many earthquake emergencies by rapidly providing the building damage, road damage, landslide and other disaster information. The earthquake in the mountains often caused to the loosening of the mountains and the blowing of the dust in the epicentre area. The dust particles are more serious in the epicentre area than the other disaster area. Basis on the analysis of abnormal spectrum characteristics, the dust detection methods from medium and high resolutions satellite imagery are studied in order to determinate the extreme earthquake disaster area. The results indicate the distribution of extreme disaster can be acquired using the dust detection information from imagery, which can provide great help for disaster intensity assessment.

The Impact of Extreme Flooding on Mussel and Microbial Nutrient Dynamics at the Water-Sediment Interface

NASA Astrophysics Data System (ADS)

Bril, J.; Just, C. L.; Newton, T.; Young, N.; Parkin, G.

2009-12-01

Labeled by the National Academy of Engineering as one of fourteen grand challenges for engineering, the management of the nitrogen cycle has become an increasingly difficult obstacle for sustainable development. In an effort to improve nitrogen cycle management practices, we are attempting to expand on the limited scientific knowledge of how aquatic environments are affected by increasing human- and climate-induced changes. To accomplish this, we are using freshwater mussels as a sentinel species to indicate how natural processes within large river systems may be altered by human activity. Freshwater mussels have been referred to as ‘ecosystem engineers’ because they exert control over food resources and alter habitats for other organisms. Also, mussels and bacteria play a major role in nutrient cycling in large river systems by cycling nutrients taken up by phytoplankton and zooplankton. Under ‘normal’ environmental conditions, mussels appear to process nitrogen more rapidly than denitrifying bacteria. However, substantial deposition of carbon-rich sediment resulting from extreme flooding may increase bacterial nitrogen cycling rates and subsequently alter overall denitrification rates. We hypothesize that intense depositions of particulate matter from recent extreme floods in the Upper Mississippi River Basin (UMRB) have altered the freshwater mussel and microbial food webs through physical and chemical means. This work will be done in a 1200-m reach of the UMRB near Buffalo, Iowa. The reach contains a healthy and diverse assemblage of freshwater mussels. A historic flood event during May-July 2008 coincided with intense spring cultivation and nutrient application activities in the heavily farmed landscape of the Upper Midwest and resulted in a significant pulse of agricultural contaminants to the UMRB. This led scientists to predict an almost unprecedented delivery of sediment and nutrients to the mussel bed, the broader Mississippi River, and ultimately to the Gulf of Mexico. We will correlate the rate of nitrogen removal by mussels to the concentrations of organic carbon that may have been deposited during the flood. Initial studies suggest that the highest amount of total organic carbon exists in areas of fine sediments within the mussel bed. Additionally, bacterial nitrate reduction studies indicate that significantly higher rates of denitrification occur in areas of high organic content. Increased availability of organic carbon may affect the rate that mussels process nitrogen. In field studies, mussel densities are generally greater in areas of coarser sediments (thus, less carbon and less bacterial nutrient processing). We are currently working to determine the role of organic carbon availability on denitrification in a laboratory system containing mussels and bacteria. We also hope to couple sediment grain size with organic carbon to compare organic carbon content pre- and post-flood.

Higher rates of sex evolve in spatially heterogeneous environments.

PubMed

Becks, Lutz; Agrawal, Aneil F

2010-11-04

The evolution and maintenance of sexual reproduction has puzzled biologists for decades. Although this field is rich in hypotheses, experimental evidence is scarce. Some important experiments have demonstrated differences in evolutionary rates between sexual and asexual populations; other experiments have documented evolutionary changes in phenomena related to genetic mixing, such as recombination and selfing. However, direct experiments of the evolution of sex within populations are extremely rare (but see ref. 12). Here we use the rotifer, Brachionus calyciflorus, which is capable of both sexual and asexual reproduction, to test recent theory predicting that there is more opportunity for sex to evolve in spatially heterogeneous environments. Replicated experimental populations of rotifers were maintained in homogeneous environments, composed of either high- or low-quality food habitats, or in heterogeneous environments that consisted of a mix of the two habitats. For populations maintained in either type of homogeneous environment, the rate of sex evolves rapidly towards zero. In contrast, higher rates of sex evolve in populations experiencing spatially heterogeneous environments. The data indicate that the higher level of sex observed under heterogeneity is not due to sex being less costly or selection against sex being less efficient; rather sex is sufficiently advantageous in heterogeneous environments to overwhelm its inherent costs. Counter to some alternative theories for the evolution of sex, there is no evidence that genetic drift plays any part in the evolution of sex in these populations.

Impact of Infection Control Measures to Control an Outbreak of Multidrug-Resistant Tuberculosis in a Human Immunodeficiency Virus Ward, Peru

PubMed Central

Ticona, Eduardo; Huaroto, Luz; Kirwan, Daniela E.; Chumpitaz, Milagros; Munayco, César V.; Maguiña, Mónica; Tovar, Marco A.; Evans, Carlton A.; Escombe, Roderick; Gilman, Robert H.

2016-01-01

Multidrug-resistant tuberculosis (MDRTB) rates in a human immunodeficiency virus (HIV) care facility increased by the year 2000—56% of TB cases, eight times the national MDRTB rate. We reported the effect of tuberculosis infection control measures that were introduced in 2001 and that consisted of 1) building a respiratory isolation ward with mechanical ventilation, 2) triage segregation of patients, 3) relocation of waiting room to outdoors, 4) rapid sputum smear microscopy, and 5) culture/drug–susceptibility testing with the microscopic-observation drug-susceptibility assay. Records pertaining to patients attending the study site between 1997 and 2004 were reviewed. Six hundred and fifty five HIV/TB–coinfected patients (mean age 33 years, 79% male) who attended the service during the study period were included. After the intervention, MDRTB rates declined to 20% of TB cases by the year 2004 (P = 0.01). Extremely limited access to antiretroviral therapy and specific MDRTB therapy did not change during this period, and concurrently, national MDRTB prevalence increased, implying that the infection control measures caused the fall in MDRTB rates. The infection control measures were estimated to have cost US$91,031 while preventing 97 MDRTB cases, potentially saving US$1,430,026. Thus, this intervention significantly reduced MDRTB within an HIV care facility in this resource-constrained setting and should be cost-effective. PMID:27621303

EXTREME-ULTRAVIOLET AND X-RAY OBSERVATIONS OF COMET LOVEJOY (C/2011 W3) IN THE LOWER CORONA

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

McCauley, Patrick I.; Saar, Steven H.; Raymond, John C.

2013-05-10

We present an analysis of extreme-ultraviolet and soft X-ray emission detected toward Comet Lovejoy (C/2011 W3) during its post-perihelion traverse of the solar corona on 2011 December 16. Observations were recorded by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory and the X-Ray Telescope (XRT) aboard Hinode. A single set of contemporaneous images is explored in detail, along with prefatory consideration for time evolution using only the 171 A data. For each of the eight passbands, we characterize the emission and derive outgassing rates where applicable. As material sublimates from the nucleus and is immersed in coronal plasma,more » it rapidly ionizes through charge states seldom seen in this environment. The AIA data show four stages of oxygen ionization (O III-O VI) along with C IV, while XRT likely captured emission from O VII, a line typical of the corona. With a nucleus of at least several hundred meters upon approach to a perihelion that brought the comet to within 0.2 R{sub Sun} of the photosphere, Lovejoy was the most significant sungrazer in recent history. Correspondingly high outgassing rates on the order of 10{sup 32.5} oxygen atoms per second are estimated. Assuming that the neutral oxygen comes from water, this translates to a mass-loss rate of {approx}9.5 Multiplication-Sign 10{sup 9} g s{sup -1}, and based only on the 171 A observations, we find a total mass loss of {approx}10{sup 13} g over the AIA egress. Additional and supporting analyses include a differential emission measure to characterize the coronal environment, consideration for the opening angle, and a comparison of the emission's leading edge with the expected position of the nucleus.« less

Response Styles in Rating Scales: Simultaneous Modeling of Content-Related Effects and the Tendency to Middle or Extreme Categories

ERIC Educational Resources Information Center

Tutz, Gerhard; Berger, Moritz

2016-01-01

Heterogeneity in response styles can affect the conclusions drawn from rating scale data. In particular, biased estimates can be expected if one ignores a tendency to middle categories or to extreme categories. An adjacent categories model is proposed that simultaneously models the content-related effects and the heterogeneity in response styles.…

Drug coated balloon in peripheral artery disease.

PubMed

Shanmugasundaram, Madhan; Murugapandian, Sangeetha; Truong, Huu Tam; Lotun, Kapildeo; Banerjee, Subhash

2018-04-21

Peripheral artery disease (PAD) is highly prevalent but is often underdiagnosed and undertreated. Lower extremity PAD can often be life style limiting. Revascularization in carefully selected lower extremity PAD patients improves symptoms and functional status. Surgical revascularization used to be the only available strategy, but in the recent years, endovascular strategies have gained popularity due to faster recovery times with low morbidity and mortality rates. Endovascular procedures have increased significantly in the United States in the past few years. That being said, higher restenosis rates and low long-term patency rates have been the limiting factors for this strategy. Drug eluting stents have been introduced to help with lowering restenosis, however lower extremity PAD involves long segment where the outcomes of stents are suboptimal. Also, the disease often crosses joint line that makes it less ideal for the stents. Drug coated balloons (DCB) have been introduced to improve patency rates following endovascular intervention for lower extremity PAD. They have gained popularity among endovascular specialists due to its ease of use and the concept of "leave nothing behind". This is a review of scientific evidence supporting DCB use in PAD. Published by Elsevier Inc.

The Psychological Essence of the Child Prodigy Phenomenon: Sensitive Periods and Cognitive Experience.

ERIC Educational Resources Information Center

Shavinina, Larisa V.

1999-01-01

Examination of the child prodigy phenomenon suggests it is a result of extremely accelerated mental development during sensitive periods that leads to the rapid growth of a child's cognitive resources and their construction into specific exceptional achievements. (Author/DB)

Transit climate change adaptation assessment/asset management pilot for the Metropolitan Atlanta Rapid Transit Authority.

DOT National Transportation Integrated Search

2013-08-01

Public transit agencies play an important role in the provision of safe, reliable, and cost-effective transportation for the communities they serve. With the growing intensity and frequency of extreme weather events, such as hurricanes Irene and Sand...

Vegetation response to early holocene warming as an analog for current and future changes: Special section

USGS Publications Warehouse

Cole, K.L.

2010-01-01

Temperatures in southwestern North America are projected to increase 3.5-4 ??C over the next 60-90 years. This will precipitate ecological shifts as the ranges of species change in response to new climates. During this shift, rapid-colonizing species should increase, whereas slow-colonizing species will at first decrease, but eventually become reestablished in their new range. This successional process has been estimated to require from 100 to over 300 years in small areas, under a stable climate, with a nearby seed source. How much longer will it require on a continental scale, under a changing climate, without a nearby seed source? I considered this question through an examination of the response of fossil plant assemblages from the Grand Canyon, Arizona, to the most recent rapid warming of similar magnitude that occurred at the start of the Holocene, 11,700 years ago. At that time, temperatures in southwestern North America increased about 4 ??C over less than a century. Grand Canyon plant species responded at different rates to this warming climate. Early-successional species rapidly increased, whereas late-successional species decreased. This shift persisted throughout the next 2700 years. I found two earlier, less-extreme species shifts following rapid warming events around 14,700 and 16,800 years ago. Late-successional species predominated only after 4000 years or more of relatively stable temperature. These results suggest the potential magnitude, duration, and nature of future ecological changes and have implications for conservation plans, especially those incorporating equilibrium assumptions or reconstituting past conditions. When these concepts are extended to include the most rapid early-successional colonizers, they imply that the recent increases in invasive exotics may be only the most noticeable part of a new resurgence of early-successional vegetation. Additionally, my results challenge the reliability of models of future vegetation and carbon balance that project conditions on the basis of assumptions of equilibrium within only a century. ?? 2009 Society for Conservation Biology.

The Influence of Conduit Processes During Basaltic Plinian Eruptions.

NASA Astrophysics Data System (ADS)

Houghton, B. F.; Sable, J. E.; Wilson, C. J.; Coltelli, M.; Del Carlo, P.

2001-12-01

Basaltic volcanism is most typically thought to produce effusion of lava, with the most explosive manifestations ranging from mild Strombolian activity to more energetic fire fountain eruptions. However, some basaltic eruptions are now recognized as extremely violent, i.e. generating widespread phreatomagmatic, subplinian and Plinian fall deposits. These eruptions are particularly dangerous because the ascent rate of basaltic magma prior to eruption can be very rapid (giving warning times as little as a few hours) and because their precursors may be ignored or misunderstood. The main question addressed in this talk is: what conditions in the conduit cause basaltic magma to adopt an eruption style more typical of chemically evolved, highly viscous magmas? Possible mechanisms (acting singly, or in concert) are: (1) interaction between magma and water, (ii) very rapid ascent producing a delayed onset of degassing then exceptionally rapid "runaway" vesiculation at shallow levels in the conduit, (iii) microlite crystallization and degassing of the magma during ascent leading to increased viscosity. We focus here on two examples of basaltic Plinian volcanism: the 1886 eruption of Tarawera, New Zealand, which is the youngest known basaltic Plinian eruption and the only one for which there are detailed written eyewitness accounts, and the well documented 122 BC eruption of Mount Etna, Italy. Field and laboratory evidence suggests that the Plinian phase of the 1886 eruption was a consequence of two processes. Firstly rheologic changes during magma ascent accompanied early (pre-fragmentation) interaction between the basaltic melt and water-bearing rhyolitic units forming the conduit walls and, secondly, late-stage magma:water interaction. In contrast, during the 122 BC eruption tectonic processes, such as slope failure or permanent displacement of a mobile flank of the volcano, appear to have triggered exceptionally rapid ascent, delayed onset of degassing and exceptionally rapid vesiculation at shallow levels in the conduit.

Carbon Dioxide Effects Research and Assessment Program. The role of tropical forests on the world carbon cycle

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

Brown, S.; Lugo, A. E.; Liegel, B.

1980-08-01

Tropical forests constitute about half of the world's forest and are characterized by rapid rates of organic matter turnover and high storages of organic matter. Tropical forests are considered to be one of the most significant terrestrial elements in the equation that balances the carbon cycle of the world. As discussed in the paper by Tosi, tropical and subtropical latitudes are more complex in terms of climate and vegetation composition than temperate and boreal latitudes. The implications of the complexity of the tropics and the disregard of this complexity by many scientists is made evident in the paper by Brownmore » and Lugo which shows that biomass estimates for tropical ecosystems have been overestimated by at least 100%. The paper by Brown shows that that rates of succession in the tropics are extremely rapid in terms of the ability of moist and wet forests to accumulate organic matter. Yet, in arid tropical Life Zones succession is slow. This leads to the idea that the question of whether tropical forests are sinks or sources of carbon must be analyzed in relation to Life Zones and to intensities of human activity in these Zones. The paper by Lugo presents conceptual models to illustrate this point and the paper by Tosi shows how land uses in the tropics also correspond to Life Zone characteristics. The ultimate significance of land use to the question of the carbon balance in a large region is addressed in the paper by Detwiler and Hall.« less

Historical changes in the Mississippi-Alabama barrier-island chain and the roles of extreme storms, sea level, and human activities

USGS Publications Warehouse

Morton, R.A.

2008-01-01

Barrier-island chains worldwide are undergoing substantial changes, and their futures remain uncertain. An historical analysis of a barrier-island chain in the north-central Gulf of Mexico shows that the Mississippi barriers are undergoing rapid systematic land loss and translocation associated with: (1) unequal lateral transfer of sand related to greater updrift erosion compared to downdrift deposition; (2) barrier narrowing resulting from simultaneous erosion of shores along the Gulf and Mississippi Sound; and (3) barrier segmentation related to storm breaching. Dauphin Island, Alabama, is also losing land for some of the same reasons as it gradually migrates landward. The principal causes of land loss are frequent intense storms, a relative rise in sea level, and a sediment-budget deficit. Considering the predicted trends for storms and sea level related to global warming, it is certain that the Mississippi-Alabama (MS-AL) barrier islands will continue to lose land area at a rapid rate unless the trend of at least one causal factor reverses. Historical land-loss trends and engineering records show that progressive increases in land-loss rate correlate with nearly simultaneous deepening of channels dredged across the outer bars of the three tidal inlets maintained for deep-draft shipping. This correlation indicates that channel-maintenance activities along the MS-AL barriers have impacted the sediment budget by disrupting the alongshore sediment transport system and progressively reducing sand supply. Direct management of this causal factor can be accomplished by strategically placing dredged sediment where adjacent barrier-island shores will receive it for island nourishment and rebuilding.

Evidence for Cluster to Cluster Variations in Low-mass Stellar Rotational Evolution

NASA Astrophysics Data System (ADS)

Coker, Carl T.; Pinsonneault, Marc; Terndrup, Donald M.

2016-12-01

The concordance model for angular momentum evolution postulates that star-forming regions and clusters are an evolutionary sequence that can be modeled with assumptions about protostar-disk coupling, angular momentum loss from magnetized winds that saturates in a mass-dependent fashion at high rotation rates, and core-envelope decoupling for solar analogs. We test this approach by combining established data with the large h Per data set from the MONITOR project and new low-mass Pleiades data. We confirm prior results that young low-mass stars can be used to test star-disk coupling and angular momentum loss independent of the treatment of internal angular momentum transport. For slow rotators, we confirm the need for star-disk interactions to evolve the ONC to older systems, using h Per (age 13 Myr) as our natural post-disk case. There is no evidence for extremely long-lived disks as an alternative to core-envelope decoupling. However, our wind models cannot evolve rapid rotators from h Per to older systems consistently, and we find that this result is robust with respect to the choice of angular momentum loss prescription. We outline two possible solutions: either there is cosmic variance in the distribution of stellar rotation rates in different clusters or there are substantially enhanced torques in low-mass rapid rotators. We favor the former explanation and discuss observational tests that could be used to distinguish them. If the distribution of initial conditions depends on environment, models that test parameters by assuming a universal underlying distribution of initial conditions will need to be re-evaluated.

Extreme warmth and heat-stressed plankton in the tropics during the Paleocene-Eocene Thermal Maximum.

PubMed

Frieling, Joost; Gebhardt, Holger; Huber, Matthew; Adekeye, Olabisi A; Akande, Samuel O; Reichart, Gert-Jan; Middelburg, Jack J; Schouten, Stefan; Sluijs, Appy

2017-03-01

Global ocean temperatures rapidly warmed by ~5°C during the Paleocene-Eocene Thermal Maximum (PETM; ~56 million years ago). Extratropical sea surface temperatures (SSTs) met or exceeded modern subtropical values. With these warm extratropical temperatures, climate models predict tropical SSTs >35°C-near upper physiological temperature limits for many organisms. However, few data are available to test these projected extreme tropical temperatures or their potential lethality. We identify the PETM in a shallow marine sedimentary section deposited in Nigeria. On the basis of planktonic foraminiferal Mg/Ca and oxygen isotope ratios and the molecular proxy [Formula: see text], latest Paleocene equatorial SSTs were ~33°C, and [Formula: see text] indicates that SSTs rose to >36°C during the PETM. This confirms model predictions on the magnitude of polar amplification and refutes the tropical thermostat theory. We attribute a massive drop in dinoflagellate abundance and diversity at peak warmth to thermal stress, showing that the base of tropical food webs is vulnerable to rapid warming.

Driving Extreme Efficiency to Market

NASA Astrophysics Data System (ADS)

Garbesi, Karina

2014-03-01

The rapid development of extremely energy efficient appliances and equipment is essential to curtail catastrophic climate disruption. This will require the on-going development of products that apply all best-practices and that take advantage of the synergies of hybridization and building integration. Beyond that, it requires the development of new disruptive technologies and concepts. To facilitate these goals, in 2011 the Lawrence Berkeley National Laboratory and the U.S. Department of Energy launched the Max Tech and Beyond Design Competition for Ultra-Low-Energy-Use Appliances and Equipment. Now in its third year, the competition supports faculty-lead student design teams at U.S. universities to develop and test new technology prototypes. This talk describes what the competition and the Max Tech Program are doing to drive such rapid technology progress and to facilitate the entry to the market of successful Max Tech prototypes. The talk also initiates a discussion of physicists' unique role in driving that technology progress faster and farther. Emerging Technologies, Building Technologies Office, U.S. Department of Energy.

Rapid detection of single bacteria in unprocessed blood using Integrated Comprehensive Droplet Digital Detection

PubMed Central

Kang, Dong-Ku; Ali, M. Monsur; Zhang, Kaixiang; Huang, Susan S.; Peterson, Ellena; Digman, Michelle A.; Gratton, Enrico; Zhao, Weian

2014-01-01

Blood stream infection or sepsis is a major health problem worldwide, with extremely high mortality, which is partly due to the inability to rapidly detect and identify bacteria in the early stages of infection. Here we present a new technology termed ‘Integrated Comprehensive Droplet Digital Detection’ (IC 3D) that can selectively detect bacteria directly from milliliters of diluted blood at single-cell sensitivity in a one-step, culture- and amplification-free process within 1.5–4 h. The IC 3D integrates real-time, DNAzyme-based sensors, droplet microencapsulation and a high-throughput 3D particle counter system. Using Escherichia coli as a target, we demonstrate that the IC 3D can provide absolute quantification of both stock and clinical isolates of E. coli in spiked blood within a broad range of extremely low concentration from 1 to 10,000 bacteria per ml with exceptional robustness and limit of detection in the single digit regime. PMID:25391809

Rapid transport from the surface to wells in fractured rock: a unique infiltration tracer experiment.

PubMed

Levison, Jana K; Novakowski, Kent S

2012-04-01

A unique infiltration tracer experiment was performed whereby a fluorescent dye was applied to the land surface in an agricultural field, near Perth, Ontario, Canada, to simulate the transport of solutes to two pumped monitoring wells drilled into the granitic gneiss aquifer. This experiment, interpreted using the discrete-fracture capability of the numerical model HydroGeoSphere, showed that solute transport from the surface through thin soil (less than 2m) to wells in fractured bedrock can be extremely rapid (on the order of hours). Also, it was demonstrated that maximum concentrations of contaminants originating from the ground surface will not necessarily be the highest in the shallow aquifer horizon. These are important considerations for both private and government-owned drinking water systems that draw water from shallow fractured bedrock aquifers. This research illustrates the extreme importance of protecting drinking water at the source. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of climate on chemical weathering in watersheds

USGS Publications Warehouse

White, A.F.; Blum, A.E.

1995-01-01

Climatic effects on chemical weathering are evaluated by correlating variations in solute concentrations and fluxes with temperature, precipitation, runoff, and evapotranspiration (ET) for a worldwide distribution of sixty-eight watersheds underlain by granitoid rock types. Stream solute concentrations are strongly correlated with proportional ET loss, and evaporative concentration makes stream solute concentrations an inapprorpiate surrogate for chemical weathering. Chemical fluxes are unaffected by ET, and SiO2 and Na weathering fluxes exhibit systematic increases with precipitation, runoff, and temperature. However, warm and wet watersheds produce anomalously rapid weathering rates. A proposed model that provides an improved prediction of weathering rates over climatic extremes is the product of linear precipitation and Arrhenius temperature functions. The resulting apparent activation energies based on SiO2 and Na fluxes are 59.4 and 62.5 kJ.mol-1, respectively. The coupling between temperature and precipitation emphasizes the importance of tropical regions in global silicate weathering fluxes, and suggests it is not representative to use continental averages for temperature and precipitation in the weathering rate functions of global carbon cycling and climatic change models. Fluxes of K, Ca, and Mg exhibit no climatic correlation, implying that other processes, such as ion exchange, nutrient cycling, and variations in lithology, obscure any climatic signal. -from Authors

Intermediate disturbance in experimental landscapes improves persistence of beetle metapopulations.

PubMed

Govindan, Byju N; Feng, Zhilan; DeWoody, Yssa D; Swihart, Robert K

2015-03-01

Human-dominated landscapes often feature patches that fluctuate in suitability through space and time, but there is little experimental evidence relating the consequences of dynamic patches for species persistence. We used a spatially and temporally dynamic metapopulation model to assess and compare metapopulation capacity and persistence for red flour beetles (Tribolium castaneum) in experimental landscapes differentiated by resource structure, patch dynamics (destruction and restoration), and connectivity. High connectivity increased the colonization rate of beetles, but this effect was less pronounced in heterogeneous relative to homogeneous landscapes. Higher connectivity and faster patch dynamics increased extinction rates in landscapes. Lower connectivity promoted density-dependent emigration. Heterogeneous landscapes containing patches of different carrying capacity enhanced landscape-level occupancy probability. The highest metapopulation capacity and persistence was observed in landscapes with heterogeneous patches, low connectivity, and slow patch dynamics. Control landscapes with no patch dynamics exhibited rapid declines in abundance and approached extinction due to increased adult mortality in the matrix, higher pupal cannibalism by adults, and extremely low rates of exchange between remaining habitable patches. Our results highlight the role of intermediate patch dynamics, intermediate connectivity, and the nature of density dependence of emigration for persistence of species in heterogeneous landscapes. Our results also demonstrate the importance of incorporating local dynamics into the estimation of metapopulation capacity for conservation planning.

Leveraging LSTM for rapid intensifications prediction of tropical cyclones

NASA Astrophysics Data System (ADS)

Li, Y.; Yang, R.; Yang, C.; Yu, M.; Hu, F.; Jiang, Y.

2017-10-01

Tropical cyclones (TCs) usually cause severe damages and destructions. TC intensity forecasting helps people prepare for the extreme weather and could save lives and properties. Rapid Intensifications (RI) of TCs are the major error sources of TC intensity forecasting. A large number of factors, such as sea surface temperature and wind shear, affect the RI processes of TCs. Quite a lot of work have been done to identify the combination of conditions most favorable to RI. In this study, deep learning method is utilized to combine conditions for RI prediction of TCs. Experiments show that the long short-term memory (LSTM) network provides the ability to leverage past conditions to predict TC rapid intensifications.

Utility of a stressed-SNP real-time PCR assay for the rapid identification of measles vaccine strain in patient samples.

PubMed

Tran, Thomas; Kostecki, Renata; Catton, Michael; Druce, Julian

2018-05-09

Rapid differentiation of wild-type measles virus from measles vaccine strains is crucial during a measles outbreak and in a measles elimination setting. A real-time RT-PCR for the rapid detection of measles vaccine strains was developed with high specificity and greater sensitivity than when compared to traditional measles genotyping methods. The "stressed" minor grove binder TaqMan probe design approach achieves specificity to vaccine strains only, without compromising sensitivity. This assay has proven to be extremely useful in outbreak settings, without requiring sequence genotyping, for over 4 years at the Regional Measles Reference Laboratory for the Western Pacific Region. Copyright © 2018 Tran et al.

Genotype by diet interactions in European sea bass (Dicentrarchus labrax L.): Nutritional challenge with totally plant-based diets.

PubMed

Le Boucher, R; Vandeputte, M; Dupont-Nivet, M; Quillet, E; Ruelle, F; Vergnet, A; Kaushik, S; Allamellou, J M; Médale, F; Chatain, B

2013-01-01

Aquaculture of carnivorous species has strongly relied on fish meal and fish oil for feed formulation; however, greater replacement by terrestrial plant-based products is occurring now. This rapid change in dietary environment has been a major revolution and has to be taken into consideration in breeding programs. The present study analyzes potential consequences of this nutritional tendency for selective breeding by estimating genetic parameters of BW and growth rates estimated by the thermal growth coefficient (TGC) over different periods with extremely different diets. European sea bass (Dicentrarchus labrax L.) from a factorial cross (1,526 fish) between 25 sires and 9 dams were used to estimate heritabilities and genotype by diet interaction. Starting 87 d after fertilization (2.5 g), one-half of the sea bass were fed a diet containing marine products (M), and the other one-half were fed a totally plant-based (PB) diet (without any fish meal or fish oil). The fish were individually tagged, reared in a recirculated system, and genotyped at 13 microsatellites to rebuild parentage of individuals. Body weight and TGC were measured for 335 d until fish fed the M diet reached 108.3 g of BW. These traits were significantly less in fish fed the PB diet (P<0.05) in the very first stages after the dietary shift, but the difference in TGC between diets rapidly disappeared (P>0.1). Survival was significantly less in fish fed the PB diet (PB=64.7%, M=93.7% after 418 d, P<0.05). This work identified moderate heritabilities (0.18 to 0.46) for BW with both diets and high genetic correlations between diets (0.78 to 0.93), meaning low genotype by diet interactions, although diets were extremely different. Heritabilities of TGC (0.11 to 0.3) were less than for BW as well as genetic correlations between diets (0.43 to 0.64). Using such extremely different diets, predicted BW gains in different scenarios indicated that selecting fish for growth on a marine diet should be the most efficient way to increase growth on plant-based diets, meaning that, in this case, indirect selection should be more efficient than direct selection.

Breaking the Habit: The Peculiar 2016 Eruption of the Unique Recurrent Nova M31N 2008-12a

NASA Astrophysics Data System (ADS)

Henze, M.; Darnley, M. J.; Williams, S. C.; Kato, M.; Hachisu, I.; Anupama, G. C.; Arai, A.; Boyd, D.; Burke, D.; Ciardullo, R.; Chinetti, K.; Cook, L. M.; Cook, M. J.; Erdman, P.; Gao, X.; Harris, B.; Hartmann, D. H.; Hornoch, K.; Horst, J. Chuck; Hounsell, R.; Husar, D.; Itagaki, K.; Kabashima, F.; Kafka, S.; Kaur, A.; Kiyota, S.; Kojiguchi, N.; Kučáková, H.; Kuramoto, K.; Maehara, H.; Mantero, A.; Masci, F. J.; Matsumoto, K.; Naito, H.; Ness, J.-U.; Nishiyama, K.; Oksanen, A.; Osborne, J. P.; Page, K. L.; Paunzen, E.; Pavana, M.; Pickard, R.; Prieto-Arranz, J.; Rodríguez-Gil, P.; Sala, G.; Sano, Y.; Shafter, A. W.; Sugiura, Y.; Tan, H.; Tordai, T.; Vraštil, J.; Wagner, R. M.; Watanabe, F.; Williams, B. F.; Bode, M. F.; Bruno, A.; Buchheim, B.; Crawford, T.; Goff, B.; Hernanz, M.; Igarashi, A. S.; José, J.; Motta, M.; O’Brien, T. J.; Oswalt, T.; Poyner, G.; Ribeiro, V. A. R. M.; Sabo, R.; Shara, M. M.; Shears, J.; Starkey, D.; Starrfield, S.; Woodward, C. E.

2018-04-01

Since its discovery in 2008, the Andromeda galaxy nova M31N 2008-12a has been observed in eruption every single year. This unprecedented frequency indicates an extreme object, with a massive white dwarf and a high accretion rate, which is the most promising candidate for the single-degenerate progenitor of a Type Ia supernova known to date. The previous three eruptions of M31N 2008-12a have displayed remarkably homogeneous multiwavelength properties: (i) from a faint peak, the optical light curve declined rapidly by two magnitudes in less than two days, (ii) early spectra showed initial high velocities that slowed down significantly within days and displayed clear He/N lines throughout, and (iii) the supersoft X-ray source (SSS) phase of the nova began extremely early, six days after eruption, and only lasted for about two weeks. In contrast, the peculiar 2016 eruption was clearly different. Here we report (i) the considerable delay in the 2016 eruption date, (ii) the significantly shorter SSS phase, and (iii) the brighter optical peak magnitude (with a hitherto unobserved cusp shape). Early theoretical models suggest that these three different effects can be consistently understood as caused by a lower quiescence mass accretion rate. The corresponding higher ignition mass caused a brighter peak in the free–free emission model. The less massive accretion disk experienced greater disruption, consequently delaying the re-establishment of effective accretion. Without the early refueling, the SSS phase was shortened. Observing the next few eruptions will determine whether the properties of the 2016 outburst make it a genuine outlier in the evolution of M31N 2008-12a.

Evaluation of the warming sensation, acceptability, and local tolerability of an acetylcysteine oral solution containing the flavoring agent IFF flavor 316282 in the treatment of productive cough
.

PubMed

Donath, Frank; Grinienko, Anna; Mallefet, Pascal; Ozun, Michel Jean-Pierre; Shneyer, Lucy

2018-04-01

This open-label study sought to evaluate the warming sensation produced by IFF flavor 316282 in an acetylcysteine oral solution in subjects with productive cough. 2% ace-tylcysteine oral solution (200 mg per 10 mL) containing IFF flavor 316282. Subjects (N = 57; mean age 38.7 years; 58% female) with a productive cough lasting < 7 days and rated as mild to moderate in severity received 10 mL of study product. Warming sensation intensity was assessed using a 100-mm visual analog scale, its onset and duration using stopwatches, its acceptability using a 9-point scale (from "dislike extremely" to "like extremely") and the taste, texture, and overall acceptability of the solution using 5-point scales (from "unacceptable" to "excellent"). 53 (93.0%) subjects perceived a warming sensation within 10 minutes of swallowing the solution; median onset was ~ 14 seconds, and median duration was ~ 2.8 minutes. Warming sensation intensity increased from baseline by a mean of 29.2 mm when evaluated 60 seconds after ingestion. 30 subjects (52.6%) thought the warming sensation was "just about right"; 25 (43.9%) considered it "too weak" or "much too weak." Most subjects had positive overall ratings ("fair," "good," or "excellent") of the taste (79.0%), texture (96.5%), and solution (91.2%). No treatment-emergent adverse events were reported, and no evidence of oral mucosal irritation was found. The addition of IFF flavor 316282 to a 2% acetylcysteine oral solution produced a warming sensation with rapid onset and relatively short duration, which the majority of subjects found acceptable.
.

Indirect Estimation of Radioactivity in Containerized Cargo

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

Jarman, Kenneth D.; Scherrer, Chad; Smith, Eric L.

Detecting illicit nuclear and radiological material in containerized cargo challenges the state of the art in detection systems. Current systems are being evaluated and new systems envisioned to address the need for the high probability of detection and extremely low false alarm rates necessary to thwart potential threats and extremely low nuisance and false alarm rates while maintaining necessary to maintain the flow of commerce impacted by the enormous volume of commodities imported in shipping containers. Maintaining flow of commerce also means that primary inspection must be rapid, requiring relatively indirect measurements of cargo from outside the containers. With increasingmore » information content in such indirect measurements, it is natural to ask how the information might be combined to improved detection. Toward this end, we present an approach to estimating isotopic activity of naturally occurring radioactive material in cargo grouped by commodity type, combining container manifest data with radiography and gamma spectroscopy aligned to location along the container. The heart of this approach is our statistical model of gamma counts within peak regions of interest, which captures the effects of background suppression, counting noise, convolution of neighboring cargo contributions, and down-scattered photons to provide physically constrained estimates of counts due to decay of specific radioisotopes in cargo alone. Coupled to that model, we use a mechanistic model of self-attenuated radiation flux to estimate the isotopic activity within cargo, segmented by location within each container, that produces those counts. We demonstrate our approach by applying it to a set of measurements taken at the Port of Seattle in 2006. This approach to synthesizing disparate available data streams and extraction of cargo characteristics holds the potential to improve primary inspection using current detection capabilities and to enable simulation-based evaluation of new candidate detection systems.« less

Resolving vorticity-driven lateral fire spread using the WRF-Fire coupled atmosphere-fire numerical model

NASA Astrophysics Data System (ADS)

Simpson, C. C.; Sharples, J. J.; Evans, J. P.

2014-05-01

Fire channelling is a form of dynamic fire behaviour, during which a wildland fire spreads rapidly across a steep lee-facing slope in a direction transverse to the background winds, and is often accompanied by a downwind extension of the active flaming region and extreme pyro-convection. Recent work using the WRF-Fire coupled atmosphere-fire model has demonstrated that fire channelling can be characterised as vorticity-driven lateral fire spread (VDLS). In this study, 16 simulations are conducted using WRF-Fire to examine the sensitivity of resolving VDLS to spatial resolution and atmosphere-fire coupling within the WRF-Fire model framework. The horizontal grid spacing is varied between 25 and 90 m, and the two-way atmosphere-fire coupling is either enabled or disabled. At high spatial resolution, the atmosphere-fire coupling increases the peak uphill and lateral spread rate by a factor of up to 2.7 and 9.5. The enhancement of the uphill and lateral spread rate diminishes at coarser spatial resolution, and VDLS is not modelled for a horizontal grid spacing of 90 m. The laterally spreading fire fronts become the dominant contributors of the extreme pyro-convection. The resolved fire-induced vortices responsible for driving the lateral spread in the coupled simulations have non-zero vorticity along each unit vector direction, and develop due to an interaction between the background winds and vertical return circulations generated at the flank of the fire front as part of the pyro-convective updraft. The results presented in this study demonstrate that both high spatial resolution and two-way atmosphere-fire coupling are required to reproduce VDLS within the current WRF-Fire model framework.

Holocene coseismic and aseismic uplift of Isla Mocha, south-central Chile

USGS Publications Warehouse

Nelson, A.R.; Manley, W.F.

1992-01-01

During the past 6000 years Isla Mocha, a 12 km-long island 30 km off the coast of south-central Chile, experienced a 38 m fall of relative sea level caused primarily by rapid tectonic uplift of the island. As many as 18 raised shorelines (strandlines) record this uplift. Historic accounts of uplift during the great earthquakes (M > 8) of 1835 and 1960 suggest some of the more prominent prehistoric strandlines also emerged during great earthquakes on the interface between the Nazca and South America plates. But the close elevational spacing of strandlines, subdued morphology of strandline beaches, scarcity of exposed bedrock wave-cut platforms, and the extremely high rates of aseismic uplift (ca. 70 mm/yr) of the island since the last great earthquake suggest that many strandlines were raised by aseismic rather than coseismic uplift. Strandline heights and 14 new radiocarbon ages on marine shells show that the present-day uplift rate is more than three times the net rate (ca. 20 mm/yr) of the past 1000 years. The recent high rate probably reflects increased aseismic slip on an inferred thrust fault in the overriding South America plate. Isla Mocha overlies an area of high stress concentration between two major segments of the Chilean subduction zone. The inferred high rate of slip on the thrust fault may be a response to stress changes on the plate interface near the boundary between the segments. ?? 1992.

Launching of Jets and the Vertical Structure of Accretion Disks

NASA Astrophysics Data System (ADS)

Ogilvie, Gordon I.; Livio, Mario

2001-05-01

The launching of magnetohydrodynamic outflows from accretion disks is considered. We formulate a model for the local vertical structure of a thin disk threaded by a poloidal magnetic field of dipolar symmetry. The model consists of an optically thick disk matched to an isothermal atmosphere. The disk is supposed to be turbulent and possesses an effective viscosity and an effective magnetic diffusivity. In the atmosphere, if the magnetic field lines are inclined sufficiently to the vertical, a magnetocentrifugal outflow is driven and passes through a slow magnetosonic point close to the surface. We determine how the rate of mass loss varies with the strength and inclination of the magnetic field. In particular, we find that for disks in which the mean poloidal field is sufficiently strong to stabilize the disk against the magnetorotational instability, the mass-loss rate decreases extremely rapidly with increasing field strength and is maximal at an inclination angle of 40°-50°. For turbulent disks with weaker mean fields, the mass-loss rate increases monotonically with increasing strength and inclination of the field, but the solution branch terminates before achieving excessive mass-loss rates. Our results suggest that efficient jet launching occurs for a limited range of field strengths and a limited range of inclination angles in excess of 30°. In addition, we determine the direction and rate of radial migration of the poloidal magnetic flux and discuss whether configurations suitable for jet launching can be maintained against dissipation.

The Weinstein conjecture with multiplicities on spherizations

NASA Astrophysics Data System (ADS)

Hertzberg, Benjamin J.

2011-07-01

Si-based anodes have recently received considerable attention for use in Li-ion batteries, due to their extremely high specific capacity---an order of magnitude beyond that offered by conventional graphite anode materials. However, during the lithiation process, Si-based anodes undergo extreme increases in volume, potentially by more than 300 %. The stresses produced within the electrode by these volume changes can damage the electrode binder, the active Si particles and the solid electrolyte interphase (SEI), causing the electrode to rapidly fail and lose capacity. These problems can be overcome by producing new anode materials incorporating both Si and C, which may offer a favorable combination of the best properties of both materials, and which can be designed with internal porosity, thereby buffering the high strains produced during battery charge and discharge with minimal overall volume changes. However, in order to develop useful anode materials, we must gain a thorough understanding of the structural, microstructural and chemical changes occurring within the electrode during the lithiation and delithiation process, and we must develop new processes for synthesizing composite anode particles which can survive the extreme strains produced during lithium intercalation of Si and exhibit no volume changes in spite of the volume changes in Si. In this work we have developed several novel synthesis processes for producing internally porous Si-C nanocomposite anode materials for Li-ion batteries. These nanocomposites possess excellent specific capacity, Coulombic efficiency, cycle lifetime, and rate capability. We have also investigated the influence of a range of different parameters on the electrochemical performance of these materials, including pore size and shape, carbon and silicon film thickness and microstructure, and binder chemistry.

Body shape transformation along a shared axis of anatomical evolution in labyrinth fishes (Anabantoidei).

PubMed

Collar, David C; Quintero, Michelle; Buttler, Bernardo; Ward, Andrea B; Mehta, Rita S

2016-03-01

Major morphological transformations, such as the evolution of elongate body shape in vertebrates, punctuate evolutionary history. A fundamental step in understanding the processes that give rise to such transformations is identification of the underlying anatomical changes. But as we demonstrate in this study, important insights can also be gained by comparing these changes to those that occur in ancestral and closely related lineages. In labyrinth fishes (Anabantoidei), rapid evolution of a highly derived torpedo-shaped body in the common ancestor of the pikehead (Luciocephalus aura and L. pulcher) occurred primarily through exceptional elongation of the head, with secondary contributions involving reduction in body depth and lengthening of the precaudal vertebral region. This combination of changes aligns closely with the primary axis of anatomical diversification in other anabantoids, revealing that pikehead evolution involved extraordinarily rapid change in structures that were ancestrally labile. Finer-scale examination of the anatomical components that determine head elongation also shows alignment between the pikehead evolutionary trajectory and the primary axis of cranial diversification in anabantoids, with much higher evolutionary rates leading to the pikehead. Altogether, our results show major morphological transformation stemming from extreme change along a shared morphological axis in labyrinth fishes. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Morphometrics of cellular damage in mice testis receiving X-ray and high-energy particle irradiation

NASA Technical Reports Server (NTRS)

Sapp, Walter J.

1987-01-01

Murine tests were exposed to single, low doses of either X-ray, helium, or argon radiation. Animals were sacrificed seventy-two hours later. Testes were fixed for transmission electron microscopy (TEM) and sectioned at either 60 nm for TEM observation or at 2 micron for counting using routine light microscope methods. Counts of the total population of surviving spermatogonia, including all type A cells, intermediate, and type B cells, were taken from tubule cross sections identified as Stage 6 and Stage 1 according to spermatogonial configuration. The surviving fraction of spermatogonia as compared to control, S/S sub o, was calculated for each dose. For both ions and X-rays, there was a rapid decline in survival at dose levels of .10 to .15 Gy in Stage 6 tubules. This was followed by a more gradual decrease in population. At higher doses, 0.30 Gy for argon and 0.80 Gy for helium and X-rays, the cell survival rates declined rapidly. Pre-leptotene spermatocytes in Stage 1 tubules exhibited a different survival curve indicating the extreme radio-sensitivity of type B spermatogonia. Data verify that the seminiferous tubules are composed of a heterogeneous population of cells with different radio-sensitivities and that these differences are manifested even at very low doses.

A small graphene oxide sheet/polyvinylidene fluoride bilayer actuator with large and rapid responses to multiple stimuli.

PubMed

Xu, Guochuang; Zhang, Miao; Zhou, Qinqin; Chen, Hongwu; Gao, Tiantian; Li, Chun; Shi, Gaoquan

2017-11-16

A high-performance actuator should be able to deliver large-shape deformations, fast actuations and sensitive responses to multiple stimuli. Here, we report such an actuator constructed from one layer of polyvinylidene fluoride (PVDF) with a high coefficient of thermal expansion (CTE), and another layer of small sheets of graphene oxide (SGO) with a negative CTE. The opposite deformations of both actuation layers make the SGO/PVDF bilayer actuator highly sensitive to the temperature stimulus with a large bending sensitivity of 1.5 cm -1 °C -1 . Upon irradiation with 60 mW cm -2 infrared light, this SGO/PVDF bilayer actuator displayed an extremely rapid tip displacement rate of 140 mm s -1 . Furthermore, this actuator can also sensitively respond to moisture because of its SGO layer, showing a curvature change from -22 to 13 cm -1 upon changing the relative humidity (RH) from 11% to 86%. This actuator can generate a contractile or relaxed stress 18 times that of mammalian skeletal muscle, under light irradiation or moisture with a response time as short as 1 s, being capable of lifting an object with a weight 80 times that of itself. Furthermore, it also showed excellent stability and repeatability.

Rapid Experimental Evolution of Pesticide Resistance in C. elegans Entails No Costs and Affects the Mating System

PubMed Central

Lopes, Patricia C.; Sucena, Élio; Santos, M. Emília; Magalhães, Sara

2008-01-01

Pesticide resistance is a major concern in natural populations and a model trait to study adaptation. Despite the importance of this trait, the dynamics of its evolution and of its ecological consequences remain largely unstudied. To fill this gap, we performed experimental evolution with replicated populations of Caenorhabditis elegans exposed to the pesticide Levamisole during 20 generations. Exposure to Levamisole resulted in decreased survival, fecundity and male frequency, which declined from 30% to zero. This was not due to differential susceptibility of males. Rather, the drug affected mobility, resulting in fewer encounters, probably leading to reduced outcrossing rates. Adaptation, i.e., increased survival and fecundity, occurred within 10 and 20 generations, respectively. Male frequency also increased by generation 20. Adaptation costs were undetected in the ancestral environment and in presence of Ivermectin, another widely-used pesticide with an opposite physiological effect. Our results demonstrate that pesticide resistance can evolve at an extremely rapid pace. Furthermore, we unravel the effects of behaviour on life-history traits and test the environmental dependence of adaptation costs. This study establishes experimental evolution as a powerful tool to tackle pesticide resistance, and paves the way to further investigations manipulating environmental and/or genetic factors underlying adaptation to pesticides. PMID:19011681

Force regulated dynamics of RPA on a DNA fork.

PubMed

Kemmerich, Felix E; Daldrop, Peter; Pinto, Cosimo; Levikova, Maryna; Cejka, Petr; Seidel, Ralf

2016-07-08

Replication protein A (RPA) is a single-stranded DNA binding protein, involved in most aspects of eukaryotic DNA metabolism. Here, we study the behavior of RPA on a DNA substrate that mimics a replication fork. Using magnetic tweezers we show that both yeast and human RPA can open forked DNA when sufficient external tension is applied. In contrast, at low force, RPA becomes rapidly displaced by the rehybridization of the DNA fork. This process appears to be governed by the binding or the release of an RPA microdomain (toehold) of only few base-pairs length. This gives rise to an extremely rapid exchange dynamics of RPA at the fork. Fork rezipping rates reach up to hundreds of base-pairs per second, being orders of magnitude faster than RPA dissociation from ssDNA alone. Additionally, we show that RPA undergoes diffusive motion on ssDNA, such that it can be pushed over long distances by a rezipping fork. Generally the behavior of both human and yeast RPA homologs is very similar. However, in contrast to yeast RPA, the dissociation of human RPA from ssDNA is greatly reduced at low Mg(2+) concentrations, such that human RPA can melt DNA in absence of force. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

HEDP and new directions for fusion energy

NASA Astrophysics Data System (ADS)

Kirkpatrick, Ronald C.

2010-06-01

Magnetic-confinement fusion energy and inertia-confinement fusion energy (IFE) represent two extreme approaches to the quest for the application of thermonuclear fusion to electrical energy generation. Blind pursuit of these extreme approaches has long delayed the achievement of their common goal. We point out the possibility of an intermediate approach that promises cheaper, and consequently more rapid development of fusion energy. For example, magneto-inertial fusion appears to be possible over a broad range of parameter space. It is further argued that imposition of artificial constraints impedes the discovery of physics solutions for the fusion energy problem.

An extremely bright gamma-ray pulsar in the Large Magellanic Cloud

NASA Astrophysics Data System (ADS)

Fermi LAT Collaboration; Ackermann, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Barbieri, C.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cuoco, A.; Cutini, S.; D'Ammando, F.; Desiante, F. de Palma R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Franckowiak, A.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hagiwara, K.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Johnson, T. J.; Knödlseder, J.; Kuss, M.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Maldera, S.; Manfreda, A.; Marshall, F.; Martin, P.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mirabal, N.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naletto, G.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Romani, R. W.; Parkinson, P. M. Saz; Schulz, A.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Uchiyama, Y.; Vianello, G.; Wood, K. S.; Wood, M.; Zampieri, L.

2015-11-01

Pulsars are rapidly spinning, highly magnetized neutron stars, created in the gravitational collapse of massive stars. We report the detection of pulsed giga-electron volt gamma rays from the young pulsar PSR J0540-6919 in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. This is the first gamma-ray pulsar detected in another galaxy. It has the most luminous pulsed gamma-ray emission yet observed, exceeding the Crab pulsar’s by a factor of 20. PSR J0540-6919 presents an extreme test case for understanding the structure and evolution of neutron star magnetospheres.

Shortening and Angulation for Soft-Tissue Reconstruction of Extremity Wounds in a Combat Support Hospital

DTIC Science & Technology

2009-08-01

l\\I ILIT\\R\\’ ’\\ I EDICt E. 174. K:83X. 2009 Shortening and Angulation for Soft-Tissue Reconstruction of Extremity Wounds in a Combat Support...team in theater. Thereafter. they can be rapidly evacuated to treatment facilities in their respective countries for definitive reconstruct ion of...cripl "’"’ rccCI\\ ec.J ft•r re’ 1ew 1n ovcmb.:r 2008. The revbe<.l manu,cnpl "a’ accepted tor publicauon 1n May 2()()9. 838 vide a reconstructive

Search for Life Beyond the Solar System. Exoplanets, Biosignatures & Instruments

NASA Astrophysics Data System (ADS)

Apai, Daniel; Gabor, Pavel

2014-03-01

Motivated by the rapidly increasing number of known Earth-sized planets, the increasing range of extreme conditions in which life on Earth can persist, and the progress toward a technology that will ultimately enable the search for life on exoplanets, the Vatican Observatory and the Steward Observatory announce a major conference entitled The Search for Life Beyond the Solar System: Exoplanets, Biosignatures & Instruments. The goal of the conference is to bring together the interdisciplinary community required to address this multi-faceted challenge: experts on exoplanet observations, early and extreme life on Earth, atmospheric biosignatures, and planet-finding telescopes.

Racetrack-shape fixed field induction accelerator for giant cluster ions

NASA Astrophysics Data System (ADS)

Takayama, Ken; Adachi, Toshikazu; Wake, Masayoshi; Okamura, Katsuya

2015-05-01

A novel scheme for a racetrack-shape fixed field induction accelerator (RAFFIA) capable of accelerating extremely heavy cluster ions (giant cluster ions) is described. The key feature of this scheme is rapid induction acceleration by localized induction cells. Triggering the induction voltages provided by the signals from the circulating bunch allows repeated acceleration of extremely heavy cluster ions. The given RAFFIA example is capable of realizing the integrated acceleration voltage of 50 MV per acceleration cycle. Using 90° bending magnets with a reversed field strip and field gradient is crucial for assuring orbit stability in the RAFFIA.

Microbiology: A microbial arsenic cycle in a salt-saturated, extreme environment

USGS Publications Warehouse

Oremland, R.S.; Kulp, T.R.; Blum, J.S.; Hoeft, S.E.; Baesman, S.; Miller, L.G.; Stolz, J.F.

2005-01-01

Searles Lake is a salt-saturated, alkaline brine unusually rich in the toxic element arsenic. Arsenic speciation changed from arsenate [As(V)] to arsenite [As(III)] with sediment depth. Incubated anoxic sediment slurries displayed dissimilatory As(V)-reductase activity that was markedly stimulated by H2 or sulfide, whereas aerobic slurries had rapid As(III)-oxidase activity. An anaerobic, extremely haloalkaliphilic bacterium was isolated from the sediment that grew via As(V) respiration, using either lactate or sulfide as its electron donor. Hence, a full biogeochemical cycle of arsenic occurs in Searles Lake, driven in part by inorganic electron donors.

Contribution of urbanization to the increase of extreme heat events in an urban agglomeration in east China: Urbanization and the Increase of EHEs

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

Yang, Xuchao; Ruby Leung, L.; Zhao, Naizhuo

The urban agglomeration of Yangtze River Delta (YRD) is emblematic of China’s rapid urbanization during the past decades. Based on homogenized daily maximum and minimum temperature data, the contributions of urbanization to trends of extreme temperature indices (ETIs) during summer in YRD are evaluated. Dynamically classifying the observational stations into urban and rural areas, this study presents unexplored changes in temperature extremes during the past four decades in the YRD region and quantifies the amplification of the positive trends in ETIs by the urban heat island effect. Overall, urbanization contributes to more than one third in the increase of intensitymore » of extreme heat events in the region, which is comparable to the contribution of greenhouse gases. Compared to rural stations, more notable shifts to the right in the probability distribution of temperature and ETIs were observed in urban stations.« less

Advanced space optics development in freeform optics design, ceramic polishing, rapid and extreme freeform polishing

NASA Astrophysics Data System (ADS)

Geyl, R.; Leplan, H.; Ruch, E.

2017-09-01

In this paper Safran-Reosc wants to share with the space community its recent work performed in the domain of space optics. Our main topic is a study about the advantages that freeform optical surfaces can offer to advanced space optics in term of compactness or performances. We have separated smart and extreme freeform in our design exploration work. Our second topic is to answer about the immediate question following: can we manufacture and test these freeform optics? We will therefore present our freeform optics capability, report recent achievement in extreme aspheric optics polishing and introduce to the industrialisation process of large off axis optics polishing for the ESO Extremely Large Telescope primary mirror segments. Thirdly we present our R-SiC polishing layer technology for SiC material. This technique has been developed to reduce costs, risks and schedule in the manufacturing of advanced SiC optics for Vis and IR applications.

xSDK Foundations: Toward an Extreme-scale Scientific Software Development Kit

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

Heroux, Michael A.; Bartlett, Roscoe; Demeshko, Irina

Here, extreme-scale computational science increasingly demands multiscale and multiphysics formulations. Combining software developed by independent groups is imperative: no single team has resources for all predictive science and decision support capabilities. Scientific libraries provide high-quality, reusable software components for constructing applications with improved robustness and portability. However, without coordination, many libraries cannot be easily composed. Namespace collisions, inconsistent arguments, lack of third-party software versioning, and additional difficulties make composition costly. The Extreme-scale Scientific Software Development Kit (xSDK) defines community policies to improve code quality and compatibility across independently developed packages (hypre, PETSc, SuperLU, Trilinos, and Alquimia) and provides a foundationmore » for addressing broader issues in software interoperability, performance portability, and sustainability. The xSDK provides turnkey installation of member software and seamless combination of aggregate capabilities, and it marks first steps toward extreme-scale scientific software ecosystems from which future applications can be composed rapidly with assured quality and scalability.« less

xSDK Foundations: Toward an Extreme-scale Scientific Software Development Kit

DOE PAGES

Heroux, Michael A.; Bartlett, Roscoe; Demeshko, Irina; ...

2017-03-01

Here, extreme-scale computational science increasingly demands multiscale and multiphysics formulations. Combining software developed by independent groups is imperative: no single team has resources for all predictive science and decision support capabilities. Scientific libraries provide high-quality, reusable software components for constructing applications with improved robustness and portability. However, without coordination, many libraries cannot be easily composed. Namespace collisions, inconsistent arguments, lack of third-party software versioning, and additional difficulties make composition costly. The Extreme-scale Scientific Software Development Kit (xSDK) defines community policies to improve code quality and compatibility across independently developed packages (hypre, PETSc, SuperLU, Trilinos, and Alquimia) and provides a foundationmore » for addressing broader issues in software interoperability, performance portability, and sustainability. The xSDK provides turnkey installation of member software and seamless combination of aggregate capabilities, and it marks first steps toward extreme-scale scientific software ecosystems from which future applications can be composed rapidly with assured quality and scalability.« less

Apatite Fission Track Constraints On The Denudational History Of The Bielsa And Millares Plutons, West-Central Pyrenees, Spain

NASA Astrophysics Data System (ADS)

Schwabe, E.; Fitzgerald, P. G.; Munoz, J. A.; Baldwin, S. L.

2006-12-01

The Pyreneean orogen extends for ~ 440 km from the Bay of Biscay to the Mediterranean Sea, forming a WNW-ESE topographic barrier between France and Spain. The mountain belt, formed by the Late Cretaceous-Early Miocene oblique collision and partial subduction of the Iberian Plate beneath the European Plate. Restored and balanced cross sections show a decrease in crustal shortening from ~165 km in the central Pyrenees to ~ 50 km in the Cantabrian margin, further to the west. The variation in shortening and crustal style is due to the decrease westward in convergence and differences in inherited geometry of pre- existing extensional faults. We propose the variation must also be reflected in the denudation record, with relative timing of the main denudational events younging to the west, as well as the magnitude and rates of denudation decreasing westward. In this study we analyze AFT data collected from vertical profiles on the southern flank of the mountains in the west-central Pyrenees. The results constrain the relative timing of structures between the central and west-central Pyrenees. AFTT data from the Bielsa and Millares massifs, located in the Bielsa and Millares thrust sheets on the southern flank of the axial zone, west-central Pyrenees yield AFT ages from 30 to 20 Ma. The data, including constraints from inverse thermal modeling, indicate denudation at rates ca. 300 m/my underway in the middle Oligocene, slowing in the Miocene. Denudation is likely related to erosion following thrusting during which the granites were transported within the south-vergent Bielsa and Millares thrust sheets. The Late Oligocene-Early Miocene AFT PAZ has since been exhumed to its present elevation. In form, results are similar to those from the central Pyrenees (Fitzgerald et al., 1999) but that Oligocene denudation in the west-central Pyrenees occurred later, was slower, and of reduced magnitude when compared to extremely rapid Oligocene denudation recorded ~50 km east in the central Pyrenees. There, as demonstrated in results from the Maladeta profile, denudation in the Early Oligocene is extremely rapid (km/my) followed by a slowing or cessation of exhumation. The Miocene PAZ preserved in both profiles suggests a similar post- orogenic history most likely related to filling and subsequent re-excavation of the Ebro Basin.

Role of Podostemum certaphyllum Michx. in structuring benthic macroinvertebrate assemblages in southern Appalachian river

Treesearch

John J. Hutchens; J. Bruce Wallance

2004-01-01

Podostemum ceratophyllum Michx. has been associated with extremely high secondary production of benthic macroinvertebrates in open-canopy rapids. We conducted an experiment in the 7th-order Little Tennessee River, North Carolina, to test whether varying amounts of Podostemum influenced macroinvertebrate...

RAPID DETECTION OF ALGAL TOXINS - PHASE I

EPA Science Inventory

The proposed program will demonstrate the ability of a detector based on measuring the conductance of nicotinic acetylcholine receptor (nAChR) ion channels to detect and quantify anatoxin-a contamination in drinking water systems.  The nAChR is extremely sensitive to the p...

Population genomics of divergence among extreme and intermediate color forms in a polymorphic insect

USDA-ARS?s Scientific Manuscript database

Geographic variation in insect coloration is among the most intriguing examples of rapid phenotypic evolution and provides ideal opportunities to study the mechanisms of phenotypic change and diversification in closely related lineages. The bumble bee Bombus bifarius comprises two geographically dis...

Extreme biology: probing life at low water contents and temperatures

USDA-ARS?s Scientific Manuscript database

Germplasm that is dried or cryopreserved appears quiescent. However, changes occur in preserved germplasm, albeit slowly. Viability time courses follow a sigmoidal curve where there is a lag phase when changes can’t be detected, followed by a period of rapid mortality. Predicting longevity under...

The Universality of the Rapid Neutron-capture Process Revealed by a Possible Disrupted Dwarf Galaxy Star

NASA Astrophysics Data System (ADS)

Casey, Andrew R.; Schlaufman, Kevin C.

2017-12-01

The rapid neutron-capture or r-process is thought to produce the majority of the heavy elements (Z> 30) in extremely metal-poor stars. The same process is also responsible for a significant fraction of the heavy elements in the Sun. This universality of the r-process is one of its characteristic features, as well as one of the most important clues to its astrophysical origin. We report the discovery of an extremely metal-poor field giant with [{Sr},{Ba}/{{H}}]≈ -6.0 and [{Sr},{Ba}/{Fe}]≈ -3.0, the lowest abundances of strontium and barium relative to iron ever observed. Despite its low abundances, the star 2MASS J151113.24-213003.0 has [{Sr}/{Ba}]=-0.11+/- 0.14, therefore its neutron-capture abundances are consistent with the main solar r-process pattern that has [{Sr}/{Ba}]=-0.25. It has been suggested that extremely low neutron-capture abundances are a characteristic of dwarf galaxies, and we find that this star is on a highly eccentric orbit with an apocenter ≳100 kpc that lies in the disk of satellites in the halo of the Milky Way. We show that other extremely metal-poor stars with low [Sr, Ba/H] and [Sr, Ba/Fe] plus solar [Sr/Ba] tend to have orbits with large apocenters, consistent with a dwarf galaxy origin for this class of object. The nucleosynthesis event that produced the neutron-capture elements in 2MASS J151113.24-213003.0 must produce both strontium and barium together in the solar ratio. We exclude contributions from the s-process in intermediate-mass asymptotic giant branch or fast-rotating massive metal-poor stars, pair-instability supernovae, the weak r-process, and neutron-star mergers. We argue that the event was a Pop III or extreme Pop II core-collapse supernova explosion. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

High-Speed Cycling Intervention Improves Rate-Dependent Mobility in Older Adults

PubMed Central

Bellumori, Maria; Uygur, Mehmet; Knight, Christopher A.

2016-01-01

PURPOSE The aim was to determine the feasibility of a six-week speed-based exercise program that could be used to initiate new exercise behaviors and improve rapid movement in older adults approaching frailty. METHODS The intervention group included 14 older adults (3 males, 11 females, mean (SD) age: 70 (7.6) years, height: 1.6 (.11) m, mass: 76.8 (12.0) kg, BMI: 27.7(4.7)). The control group included 12 older adults (6 males, 6 females, mean (SD) age: 69.2 (6.9) years, height: 1.7 (.09) m, mass: 78.2 (10.9) kg, BMI: 25.3 (2.7)). Subjects included active older adults, including regular exercisers, but none were engaged in sports or exercises with an emphasis on speed (e.g. cycling spin classes or tennis). Stationary recumbent cycling was selected to minimize fall risk and low pedaling resistance reduced musculoskeletal and cardiovascular load. Two weekly 30-minute exercise sessions consisted of interval training in which subjects pedaled at preferred cadence and performed ten 20-s fast cadence intervals separated by 40-s of active recovery at preferred cadence. RESULTS Significant Group by Time interactions (p<.05) supported a 2-s improvement in the timed up and go test and a 34% improvement in rapid isometric knee extension contractions in the exercise group but not in controls. Central neural adaptations are suggested because this lower extremity exercise program also elicited significant improvements in the untrained upper extremities of the exercise group (elbow extension RFD-SF and 9-Hole Peg Test, p<.05). CONCLUSION These results demonstrate that a relatively low dose of speed-based exercise can improve neuromuscular function and tests of mobility in older adults. Such a program serves as a sensible precursor to subsequent, more vigorous training or as an adjunct to a program where a velocity emphasis is lacking. PMID:27501360

Deep Chandra , HST-COS, and megacam observations of the Phoenix cluster: Extreme star formation and AGN feedback on hundred kiloparsec scales

DOE PAGES

McDonald, Michael; McNamara, Brian R.; Perimeter Institute for Theoretical Physics, Waterloo; ...

2015-09-28

In this study, we present new ultraviolet, optical, and X-ray data on the Phoenix galaxy cluster (SPT-CLJ2344-4243). Deep optical imaging reveals previously undetected filaments of star formation, extending to radii of ~50–100 kpc in multiple directions. Combined UV-optical spectroscopy of the central galaxy reveals a massive (2 × 10 9 M ⊙), young (~4.5 Myr) population of stars, consistent with a time-averaged star formation rate of 610 ± 50 M ⊙ yr –1. We report a strong detection of O vi λλ1032,1038, which appears to originate primarily in shock-heated gas, but may contain a substantial contribution (>1000 M ⊙ yrmore » –1) from the cooling intracluster medium (ICM). We confirm the presence of deep X-ray cavities in the inner ~10 kpc, which are among the most extreme examples of radio-mode feedback detected to date, implying jet powers of 2 – 7 × 10 45 erg s –1. We provide evidence that the active galactic nucleus inflating these cavities may have only recently transitioned from "quasar-mode" to "radio-mode," and may currently be insufficient to completely offset cooling. A model-subtracted residual X-ray image reveals evidence for prior episodes of strong radio-mode feedback at radii of ~100 kpc, with extended "ghost" cavities indicating a prior epoch of feedback roughly 100 Myr ago. This residual image also exhibits significant asymmetry in the inner ~200 kpc (0.15R 500), reminiscent of infalling cool clouds, either due to minor mergers or fragmentation of the cooling ICM. Taken together, these data reveal a rapidly evolving cool core which is rich with structure (both spatially and in temperature), is subject to a variety of highly energetic processes, and yet is cooling rapidly and forming stars along thin, narrow filaments.« less

An Ocean Acidification Pulse in the Pre-onset Carbon Isotope Excursion Preceding the Paleocene-Eocene Thermal Maximum

NASA Astrophysics Data System (ADS)

Robinson, M. M.; Self-Trail, J. M.; Willard, D. A.; Stassen, P.; Spivey, W.

2015-12-01

The Paleocene-Eocene Thermal Maximum (PETM; ~55.5 Ma) is recognized globally in marine sediments by a carbonate dissolution zone, the extinction or turnover of benthic taxa, and a radiation of planktic excursion taxa, all accompanied by a rapid-onset, negative carbon isotope excursion (CIE). The cause and nature of the massive carbon release leading to this extreme climate event remains under debate. Regardless of cause, the environmental and ecosystem changes centered on the PETM are the subject of much study because they provide an analog to modern deteriorating conditions associated with the ongoing rise in atmospheric carbon dioxide. We present evidence from sediments of the South Dover Bridge core, deposited on the U.S. mid-Atlantic shelf, for an ocean acidification event in the latest Paleocene that coincides with a relatively small (-2‰) negative carbon isotope excursion (CIE) that precedes the larger (-4‰) Paleocene-Eocene CIE onset. Planktic foraminifers during this pre-onset event (POE) show post-deposition dissolution in which the coarsely cancellate and muricate wall textures characteristic of many Late Paleocene species have been dissolved away, leaving smooth, thin-walled specimens often with collapsed chambers. In addition, we document biotic responses in benthic, planktic, and terrestrial communities to the POE, including shifts in foraminifer and pollen assemblages and adaptations in calcareous nannofossil species in response to environmental perturbations. A complete recovery is evident between the POE and CIE in both the carbon isotopic signal and in the biotic response, providing additional evidence not only for a pulsed carbon release, but also for a more rapid rate of carbon release than is suggested by a single pulse over a longer period of time. The timing, nature and magnitude of ecological changes during the less extreme POE shallow water acidification event may help to define the ecological tipping point of shallow marine ecosystems.

Injuries in taekwando: systematic review.

PubMed

Thomas, Roger E; Thomas, Bennett C; Vaska, Marcus M

2017-11-01

Assess rates/1000athletic encounters(AE) in Taekwondo of injuries/age/gender/type/location. Searches in 17 electronic, 7 grey-literature databases. Two researchers independently assessed Abstracts/titles and abstracted data. Risk-of-bias assessed with Newcastle-Ottawa scale. Rates/1000AE computed, weighted by study sizes. Eighteen studies included 3 Olympic, 4 world, 1 European, 13 national, 10 provincial and one national school competition. Seventeen studies provided an injury definition and recorded injuries on forms. Rates are average rate/1000AE, weighted by study size. For ten studies which provided rates by gender, rate for males(n = 9,286) was 58/1000AE and females(n = 3,720) 52.7/1000AE. For six studies which provided data on injuries/1000minutes/exposure by gender rate for males(n = 6,885) was 10.7/1000minutes/exposure and for females(n = 2,539) 10.4. For two studies which provided data by age and gender, rate for males 11-13 years(n = 949) was 29.6, 14-17(n = 512) 53.1 and ≥18(n = 711) 40.7, and for females 11-13 years(n = 472) 30.5, 14-17(n = 338) 72 and ≥18(n = 240) 37.5. For eight studies which provided injury location rates by gender rate for all ages for males(n = 5,856) for head/neck injuries was 13.3, torso 4.2, upper-extremity 9.4 and lower-extremity 21.7 and females(n = 2,126) for head/neck injuries was 14.2, torso 3.1, upper-extremity 7.3 and lower-extremity 26.6. For nine studies which provided injury type rates by gender, rate for all ages for males(n = 7,509) for abrasions/contusions/lacerations was 37.5, for sprains/strains 10.3 and fractures 5.9, and for females(n = 2,852) for abrasions/contusions/lacerations 27.9, for sprains/strains 8.7 and fractures 3.8. For concussions for eight studies for males(n = 9,078) rate was 13.3 and females(n = 3628) 11.4. The majority of injuries occurred to the lower extremities, and in defence (61%). There are published data on 20,210 Taekweondo competitors. Only 8/18 studies reported prior injuries. Longitudinal studies are needed of injuries, ascertainment of causes, identify participants with higher rates, measure the results of preventive measures, rule change to exclude head kicks, and encourage non-contact Taekwondo especially for participants with high injury rates.

Rapid identification of group JK and other corynebacteria with the Minitek system.

PubMed Central

Slifkin, M; Gil, G M; Engwall, C

1986-01-01

Forty primary clinical isolates and 50 stock cultures of corynebacteria and coryneform bacteria were tested with the Minitek system (BBL Microbiology Systems, Cockeysville, Md.). The Minitek correctly identified all of these organisms, including JK group isolates, within 12 to 18 h of incubation. The method does not require serum supplements for testing carbohydrate utilization by the bacteria. The Minitek system is an extremely simple and rapid way to identify the JK group, as well as many other corynebacteria, by established identification schemata for these bacteria. PMID:3091632

Rapidly variable relatvistic absorption

NASA Astrophysics Data System (ADS)

Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

2017-10-01

I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

Sea-level and tectonic control of middle to late Pleistocene turbidite systems in Santa Monica Basin, offshore California

USGS Publications Warehouse

Normark, W.R.; Piper, D.J.W.; Sliter, R.

2006-01-01

Small turbidite systems offshore from southern California provide an opportunity to track sediment from river source through the turbidity-current initiation process to ultimate deposition, and to evaluate the impact of changing sea level and tectonics. The Santa Monica Basin is almost a closed system for terrigenous sediment input, and is supplied principally from the Santa Clara River. The Hueneme fan is supplied directly by the river, whereas the smaller Mugu and Dume fans are nourished by southward longshore drift. This study of the Late Quaternary turbidite fill of the Santa Monica Basin uses a dense grid of high-resolution seismic-reflection profiles tied to new radiocarbon ages for Ocean Drilling Program (ODP) Site 1015 back to 32 ka. Over the last glacial cycle, sedimentation rates in the distal part of Santa Monica Basin averaged 2-3 mm yr-1, with increases at times of extreme relative sea-level lowstand. Coarser-grained mid-fan lobes prograded into the basin from the Hueneme, Mugu and Dume fans at times of rapid sea-level fall. These pulses of coarse-grained sediment resulted from river channel incision and delta cannibalization. During the extreme lowstand of the last glacial maximum, sediment delivery was concentrated on the Hueneme Fan, with mean depositional rates of up to 13 mm yr-1 on the mid- and upper fan. During the marine isotope stage (MIS) 2 transgression, enhanced rates of sedimentation of > 4 mm yr-1 occurred on the Mugu and Dume fans, as a result of distributary switching and southward littoral drift providing nourishment to these fan systems. Longer-term sediment delivery to Santa Monica Basin was controlled by tectonics. Prior to MIS 10, the Anacapa ridge blocked the southward discharge of the Santa Clara River into the Santa Monica Basin. The pattern and distribution of turbidite sedimentation was strongly controlled by sea level through the rate of supply of coarse sediment and the style of initiation of turbidity currents. These two factors appear to have been more important than the absolute position of sea level. ?? 2006 The Authors. Journal compilation 2006 International Association of Sedimentologists.

Effects of Extreme Events on Arsenic Cycling in Salt Marshes

NASA Astrophysics Data System (ADS)

Northrup, Kristy; Capooci, Margaret; Seyfferth, Angelia L.

2018-03-01

Extreme events such as storm surges, intense precipitation, and supermoons cause anomalous and large fluctuations in water level in tidal salt marshes, which impacts the sediment biogeochemistry that dictates arsenic (As) cycling. In addition to changes in water level, which impacts soil redox potential, these extreme events may also change salinity due to freshwater inputs from precipitation or saltwater inputs due to surge. It is currently unknown how As mobility in tidal salt marshes will be impacted by extreme events, as fluctuations in salinity and redox potential may act synergistically to mobilize As. To investigate impacts of extreme events on As cycling in tidal salt marshes, we conducted a combined laboratory and field investigation. We monitored pore water and soil samples before, during, and after two extreme events: a supermoon lunar eclipse followed by a storm surge and precipitation induced by Hurricane Joaquin in fall 2015 at the St. Jones Reserve in Dover, Delaware, a representative tidal salt marsh in the Mid-Atlantic United States. We also conducted soil incubations of marsh sediments in batch and in flow-through experiments in which redox potential and/or salinity were manipulated. Field investigations showed that pore water As was inversely proportional to redox potential. During the extreme events, a distinct pulse of As was observed in the pore water with maximum salinity. Combined field and laboratory investigations revealed that this As pulse is likely due to rapid changes in salinity. These results have implications for As mobility in the face of extreme weather variability.

The effect of age on outcomes after isolated limb perfusion for advanced extremity malignancies.

PubMed

Smith, H G; Wilkinson, M J; Smith, M J F; Strauss, D C; Hayes, A J

2018-06-22

Isolated limb perfusion (ILP) is a well-established treatment for patients with advanced extremity malignancies unsuitable for limb-conserving surgery. However, little is known about the outcomes of this treatment in elderly patients. We sought to determine the effects of age on the tolerability and efficacy of ILP for advanced extremity malignancy. Patients undergoing ILP at our institution between January 2005 and January 2018 were identified from a prospectively maintained database. Patients were stratified by pathology (melanoma, soft-tissue sarcoma, other) and age (<75 years and ≥75 years). Outcomes of interest were perioperative morbidity and mortality, locoregional toxicities, response rates and oncological outcomes. During the study period, a total of 189 perfusions were attempted. Successful perfusions were performed in 179 patients, giving a technical success rate of 94.7%. No difference in perfusion success rates, severe locoregional toxicity and perioperative morbidity or mortality was noted between those aged <75 years and ≥75 years. The overall response rate in melanoma was 82.4%, and no difference in response rates or oncological outcomes between age groups was noted in these patients. The overall response rate in soft-tissue sarcoma was 63.5%, with no difference in response rates noted between age groups. However, patients aged <75 years with soft-tissue sarcoma had prolonged local recurrence-free survival compared with older patients (13 versus 6 months), possibly due to the prevalence of chemosensitive subtypes in the younger age group. ILP is an effective treatment for advanced extremity malignancies in the elderly, with comparable response rates and toxicities to younger patients. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Kinetic control on Zn isotope signatures recorded in marine diatoms

NASA Astrophysics Data System (ADS)

Köbberich, Michael; Vance, Derek

2017-08-01

Marine diatoms dominate the oceanic cycle of the essential micronutrient zinc (Zn). The stable isotopes of zinc and other metals are increasingly used to understand trace metal micronutrient cycling in the oceans. One clear feature of the early isotope data is the heavy Zn isotope signature of the average oceanic dissolved pool relative to the inputs, potentially driven by uptake of light isotopes into phytoplankton cells and export to sediments. However, despite the fact that diatoms strip Zn from surface waters across the Antarctic polar front in the Southern Ocean, the local upper ocean is not isotopically heavy. Here we use culturing experiments to quantify the extent of Zn isotope fractionation by diatoms and to elucidate the mechanisms driving it. We have cultured two different open-ocean diatom species (T. oceanica and Chaetoceros sp.) in a series of experiments at constant medium Zn concentration but at bioavailable medium Fe ranging from limiting to replete. We find that T. oceanica can maintain high growth rates and Zn uptake rates over the full range of bioavailable iron (Fe) investigated, and that the Zn taken up has a δ66Zn that is unfractionated relative to that of the bioavailable free Zn in the medium. The studied representative of the genus Chaetoceros, on the other hand, shows more significantly reduced Zn uptake rates at low Fe and records more variable biomass δ66Zn signatures, of up to 0.85‰ heavier than the medium. We interpret the preferential uptake of heavy isotopes at extremely low Zn uptake rates as potentially due to either of the following two mechanisms. First, the release of extracellular polymeric substances (EPS), at low Fe levels, may preferentially scavenge heavy Zn isotopes. Second, the Zn uptake rate may be slow enough to establish pseudo-equilibrium conditions at the transporter site, with heavy Zn isotopes forming more stable surface complexes. Thus we find that, in our experiments, Fe-limitation exerts a key control that not only limits diatom growth, but also affects the Zn uptake physiology of diatoms. Uptake of heavy isotopes occurs under Fe-limiting conditions that drive extremely low Zn uptake rates. On the other hand, more rapid Zn uptake rates result in biomass that is indistinguishable from the external bioavailable free Zn pool. These experimental results can, in principle, explain the range of Zn isotopic compositions found in the real surface ocean, given the geographically variable interplay between Fe-limitation, Zn uptake rates, and the degree of organic complexation of oceanic Zn.

Detection of photosynthetic responses of cool-temperate forests following extreme climate events using Bayesian inversion

NASA Astrophysics Data System (ADS)

Toda, M.; Knohl, A.; Herbst, M.; Keenan, T. F.; Yokozawa, M.

2016-12-01

The increase in extreme climate events associated with ongoing global warming may create severe damage to terrestrial ecosystems, changing plant structure and the eco-physiological functions that regulate ecosystem carbon exchange. However, most damage is usually due to moderate, rather than catastrophic, disturbances. The nature of plant functional responses to such disturbances, and the resulting effects on the terrestrial carbon cycle, remain poorly understood. To unravel the scientific question, tower-based eddy covariance data in the cool-temperate forests were used to constrain plant eco-physiological parameters in a persimoneous ecosystem model that may have affected carbon dynamics following extreme climate events using the statistic Bayesian inversion approach. In the present study, we raised two types of extreme events relevant for cool-temperate regions, i.e. a typhoon with mechanistic foliage destraction and a heat wave with severe drought. With appropriate evaluation of parameter and predictive uncertainties, the inversion analysis shows annual trajectory of activated photosynthetic responses following climate extremes compared the pre-disturbance state in each forest. We address that forests with moderate disturbance show substantial and rapid photosynthetic recovery, enhanced productivity, and, thus, ecosystem carbon exchange, although the effect of extreme climatic events varies depending on the stand successional phase and the type, intensity, timing and legacy of the disturbance.

Spatiotemporal changes of normalized difference vegetation index (NDVI) and response to climate extremes and ecological restoration in the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Zhao, Anzhou; Zhang, Anbing; Liu, Xianfeng; Cao, Sen

2018-04-01

Extreme drought, precipitation, and other extreme climatic events often have impacts on vegetation. Based on meteorological data from 52 stations in the Loess Plateau (LP) and a satellite-derived normalized difference vegetation index (NDVI) from the third-generation Global Inventory Modeling and Mapping Studies (GIMMS3g) dataset, this study investigated the relationship between vegetation change and climatic extremes from 1982 to 2013. Our results showed that the vegetation coverage increased significantly, with a linear rate of 0.025/10a ( P < 0.001) from 1982 to 2013. As for the spatial distribution, NDVI revealed an increasing trend from the northwest to the southeast, with about 61.79% of the LP exhibiting a significant increasing trend ( P < 0.05). Some temperature extreme indices, including TMAXmean, TMINmean, TN90p, TNx, TX90p, and TXx, increased significantly at rates of 0.77 mm/10a, 0.52 °C/10a, 0.62 °C/10a, 0.80 °C/10a, 5.16 days/10a, and 0.65 °C/10a, respectively. On the other hand, other extreme temperature indices including TX10p and TN10p decreased significantly at rates of -2.77 days/10a and 4.57 days/10a ( P < 0.01), respectively. Correlation analysis showed that only TMINmean had a significant relationship with NDVI at the yearly time scale ( P < 0.05). At the monthly time scale, vegetation coverage and different vegetation types responded significantly positively to precipitation and temperature extremes (TMAXmean, TMINmean, TNx, TNn, TXn, and TXx) ( P < 0.01). All of the precipitation extremes and temperature extremes exhibited significant positive relationships with NDVI during the spring and autumn ( P < 0.01). However, the relationship between NDVI and RX1day, TMAXmean, TXn, and TXx was insignificant in summer. Vegetation exhibited a significant negative relationship with precipitation extremes in winter ( P < 0.05). In terms of human activity, our results indicate a strong correlation between the cumulative afforestation area and NDVI in Yan'an and Yulin during 1998-2013, r = 0.859 and 0.85, n = 16, P < 0.001.

Does extreme precipitation intensity depend on the emissions scenario?

NASA Astrophysics Data System (ADS)

Pendergrass, Angeline; Lehner, Flavio; Sanderson, Benjamin; Xu, Yangyang

2016-04-01

The rate of increase of global-mean precipitation per degree surface temperature increase differs for greenhouse gas and aerosol forcings, and therefore depends on the change in composition of the emissions scenario used to drive climate model simulations for the remainder of the century. We investigate whether or not this is also the case for extreme precipitation simulated by a multi-model ensemble driven by four realistic emissions scenarios. In most models, the rate of increase of maximum annual daily rainfall per degree global warming in the multi-model ensemble is statistically indistinguishable across the four scenarios, whether this extreme precipitation is calculated globally, over all land, or over extra-tropical land. These results indicate that, in most models, extreme precipitation depends on the total amount of warming and does not depend on emissions scenario, in contrast to mean precipitation.

Failed Endotracheal Intubation and Adverse Outcomes Among Extremely Low Birth Weight Infants

PubMed Central

Wallenstein, Matthew B.; Birnie, Krista L.; Arain, Yassar H.; Yang, Wei; Yamada, Nicole K.; Huffman, Lynne C.; Palma, Jonathan P.; Chock, Valerie Y.; Shaw, Gary M.; Stevenson, David K.

2015-01-01

OBJECTIVE To quantify the importance of successful endotracheal intubation on the first attempt among extremely low birth weight (ELBW) infants who require resuscitation after delivery. STUDY DESIGN A retrospective chart review was conducted for all ELBW infants ≤1000 g born between January 2007 and May 2014 at a level IV neonatal intensive care unit. Infants were included if intubation was attempted during the first five minutes of life, or if intubation was attempted during the first 10 minutes of life with heart rate < 100. The primary outcome was death or neurodevelopmental impairment. The association between successful intubation on the first attempt and the primary outcome was assessed using multivariable logistic regression with adjustment for birth weight, gestational age, gender, and antenatal steroids. RESULTS The study sample included 88 ELBW infants. Forty-percent were intubated on the first attempt and 60% required multiple intubation attempts. Death or neurodevelopmental impairment occurred in 29% of infants intubated on the first attempt, compared to 53% of infants that required multiple attempts, adjusted odds ratio 0.4 (95% confidence interval 0.1 - 1.0), p < 0.05. CONCLUSION Successful intubation on the first attempt is associated with improved neurodevelopmental outcomes among ELBW infants. This study confirms the importance of rapid establishment of a stable airway in ELBW infants requiring resuscitation after birth and has implications for personnel selection and role assignment in the delivery room. PMID:26540244

How cells jump: Ultrafast motions in the single-celled micro-organism Halteria grandinella

NASA Astrophysics Data System (ADS)

Krishnamurthy, Deepak; Cockenpot, Fabien; Prakash, Manu

Here we describe a novel behavior of ''jumping'' in micro-organisms, observed in the common freshwater ciliate Halteria grandinella. This organism's swimming motion is characterized by periods of forward swimming at around 10 body lengths/s punctuated by extremely rapid backward ''jumps'' where the organism reaches speeds of more than 150 body lengths/s. We show, using detailed measurements of the swimming motion through high-speed video microscopy, that the extreme swimming speeds are achieved by the motile cilia transitioning to a beating mode characterized by a significantly larger beat amplitude and an associated reversal in the direction of thrust production. We further show that H.grandinella cells can sense a fluid shear stress signal and ''jump'' in response: a possible predator avoidance mechanism. We investigate this mechanism of shear sensing and study the role of the long, slender structures known as ''cirri'' as microscale sensors of shear stress. The jumping of H.grandinella is at the limits of the metabolic rate of the organism and thus offers insights into the limiting factors governing energy storage and mechanical power release at the microscale. Concurrently their sensing apparatus allows an understanding of the physical limits of microscale mechanical sensing. This material is based on work supported by, or in part by, the US Army Research Laboratory and the US Army Research Office under contract/Grant Number W911NF-15-1-0358.

High Fill-out, Extreme Mass Ratio Overcontact Binary Systems. X. The Newly Discovered Binary XY Leonis Minoris

NASA Astrophysics Data System (ADS)

Qian, S.-B.; Liu, L.; Zhu, L.-Y.; He, J.-J.; Yang, Y.-G.; Bernasconi, L.

2011-05-01

The newly discovered short-period close binary star, XY LMi, has been monitored photometrically since 2006. Its light curves are typical EW-type light curves and show complete eclipses with durations of about 80 minutes. Photometric solutions were determined through an analysis of the complete B, V, R, and I light curves using the 2003 version of the Wilson-Devinney code. XY LMi is a high fill-out, extreme mass ratio overcontact binary system with a mass ratio of q = 0.148 and a fill-out factor of f = 74.1%, suggesting that it is in the late evolutionary stage of late-type tidal-locked binary stars. As observed in other overcontact binary stars, evidence for the presence of two dark spots on both components is given. Based on our 19 epochs of eclipse times, we found that the orbital period of the overcontact binary is decreasing continuously at a rate of dP/dt = -1.67 × 10-7 days yr-1, which may be caused by mass transfer from the primary to the secondary and/or angular momentum loss via magnetic stellar wind. The decrease of the orbital period may result in the increase of the fill-out, and finally, it will evolve into a single rapid-rotation star when the fluid surface reaches the outer critical Roche lobe.

The magnetodynamic filters in monitoring the contaminants from polluted water systems (abstract)

NASA Astrophysics Data System (ADS)

Swarup, R.; Singh, Bharat

1994-05-01

The magnetic interaction seems to influence the ``structural memory'' of water systems which is quenched in ideally pure water. The sedentary lifetime of each water molecule is extremely short (10-10 s) and its molecular structures may be influenced by some physical effect like magnetic field treatment, it's space time gradients, water velocity, pressure drop, etc. in the interpolar space, so as to yield a noticeable temporal magnetopotential development characterizing the properties of homogeneous and heterogeneous water systems. This principle is also extended to prevailing water systems which always contain various impurities, gas, molecules, ions, microscopic particles in random order. Still the existence of structural memory may be verified by reliable experimental data. The magnetopotential curves of different water systems depict the design and develop-software package for constructing the magnetodynamic-filters superior to the existing techniques on pollution studies like remote sensing, muon spin resonance, laser spectroscopy, nuclear techniques, the gamma ray peak efficiency method, trace elemental characterization due to NBS, neutron activation analysis, and graphite furnance atomic absorption spectrometer. The physiochemical characteristics of water calibrated in terms of magnetopotential curves change with the removal of dissolved gasses, impurities, thermal activation, etc. and the algae, bacteria, phosphates, etc. have been removed at a rapid rate. The magnetodynamic study of ganga water proves it to be an extremely pure and highly resourced fluid.

Ancestral genetic diversity associated with the rapid spread of stress-tolerant coral symbionts in response to Holocene climate change

PubMed Central

Hume, Benjamin C. C.; Voolstra, Christian R.; Arif, Chatchanit; D’Angelo, Cecilia; Burt, John A.; Eyal, Gal; Loya, Yossi; Wiedenmann, Jörg

2016-01-01

Coral communities in the Persian/Arabian Gulf (PAG) withstand unusually high salinity levels and regular summer temperature maxima of up to ∼35 °C that kill conspecifics elsewhere. Due to the recent formation of the PAG and its subsequent shift to a hot climate, these corals have had only <6,000 y to adapt to these extreme conditions and can therefore inform on how coral reefs may respond to global warming. One key to coral survival in the world’s warmest reefs are symbioses with a newly discovered alga, Symbiodinium thermophilum. Currently, it is unknown whether this symbiont originated elsewhere or emerged from unexpectedly fast evolution catalyzed by the extreme environment. Analyzing genetic diversity of symbiotic algae across >5,000 km of the PAG, the Gulf of Oman, and the Red Sea coastline, we show that S. thermophilum is a member of a highly diverse, ancient group of symbionts cryptically distributed outside the PAG. We argue that the adjustment to temperature extremes by PAG corals was facilitated by the positive selection of preadapted symbionts. Our findings suggest that maintaining the largest possible pool of potentially stress-tolerant genotypes by protecting existing biodiversity is crucial to promote rapid adaptation to present-day climate change, not only for coral reefs, but for ecosystems in general. PMID:27044109

Reply to Rhines and Huybers: Changes in the Frequency of Extreme Summer Heat

NASA Technical Reports Server (NTRS)

Hansen, James; Sato, Makiko; Ruedy, Reto

2013-01-01

Rhines and Huybers are correct that the decreasing number of measurement stations in recent years contributed slightly to our calculated increase of extreme summer mean temperature anomalies. However, the increased frequency of extreme heat anomalies is accounted for mainly by (i) higher mean temperature of recent decades relative to the base period 1951-1980, and (ii) the continuing upward temperature trend during recent decades. The effect of decreasing stations is shown by comparing our prior analysis with results using only stations with data records in both the base period and recent years (Fig. 1). The distribution is noisier, and the area with temperature anomaly exceeding three SDs during 2001-2011 decreases from 9.6 to 9.3% for the reduced number of stations (1,886 rather than 6,147), but our conclusions are not changed qualitatively. The temperature anomaly distribution shifts to the right and broadens because it is defined relative to a fixed (1951-1980) base period, during which global temperatures were within the Holocene range. We argue on the basis of accelerating ice loss from Greenland and Antarctica and rapidly rising sea level (now exceeding 3 mm/y or 3 m per millennium) that temperatures in the early 21st century are already above the Holocene range, and thus use of a base period preceding the rapid warming of the past three decades has merit.

Climate extremes and the carbon cycle - a review using an integrated approach with regional examples for forests & native ecosystems -

NASA Astrophysics Data System (ADS)

Frank, D.; Reichstein, M.; Bahn, M.; Beer, C.; Ciais, P.; Mahecha, M.; Seneviratne, S. I.; Smith, P.; van Oijen, M.; Walz, A.

2012-04-01

The terrestrial carbon cycle provides an important biogeochemical feedback to climate and is itself particularly susceptible to extreme climate events. Climate extremes can override any (positive) effects of mean climate change as shown in European and recent US-American heat waves and dry spells. They can impact the structure, composition, and functioning of terrestrial ecosystems and have the potential to cause rapid carbon losses from accumulated stocks. We review how climate extremes like severe droughts, heat waves, extreme precipitation or storms can cause direct impacts on the CO2 fluxes [e.g. due to extreme temperature and/ or drought events] as well as lagged impacts on the carbon cycle [e.g. via an increased fire risk, or disease outbreaks and pest invasions]. The relative impact of the different climate extremes varies according to climate region and vegetation type. We present lagged effects on plant growth (and mortality) in the year(s) following an extreme event and their impacts on the carbon sequestration of forests and natural ecosystems. Comprehensive regional or even continental quantification with regard to extreme events is missing, and especially compound extreme events, the role of lagged effects and aspects of the return frequency are not studied enough. In a case study of a Mediterranean ecosystem we illustrate that the response of the net carbon balance at ecosystem level to regional climate change is hard to predict as interacting and partly compensating processes are affected and several processes which have the ability to substantially alter the carbon balance are not or not sufficiently represented in state-of-the-art biogeochemical models.

Removal rates of dissolved munitions compounds in seawater.

PubMed

Smith, Richard W; Vlahos, Penny; Tobias, Craig; Ballentine, Mark; Ariyarathna, Thivanka; Cooper, Christopher

2013-08-01

The historical exposure of coastal marine systems to munitions compounds is of significant concern due to the global distribution of impacted sites and known toxicological effects of nitroaromatics. In order to identify specific coastal regions where persistence of these chemicals should be of concern, it is necessary to experimentally observe their behavior under a variety of realistic oceanographic conditions. Here, we conduct a mesocosm scale pulse addition experiment to document the behavior of two commonly used explosives, 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in simulated marine systems containing water and sediments collected from Long Island Sound, CT. The addition of sediments and sediment grain-size had a major influence on the loss rates of all compounds detected. RDX and reduced TNT products were removed from seawater only in the presence of sediment, and TNT degraded significantly faster in the presence of sediment. Both compounds were removed from the system faster with decreasing grain-size. Based on these findings and a thorough review of the literature, we hypothesize that in addition to bacterial abundance and nutrient availability, TNT removal rates in coastal marine waters may be controlled by sorption and rapid surface-mediated bacterial transformation, while RDX removal rates are controlled by diffusion into sedimentary anoxic regions and subsequent anaerobic bacterial breakdown. A comparison of published removal rates of RDX and TNT highlights the extreme variability in measured degradation rates and identifies physicochemical variables that covary with the breakdown of these munitions compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

The nonequilibrium quantum many-body problem as a paradigm for extreme data science

NASA Astrophysics Data System (ADS)

Freericks, J. K.; Nikolić, B. K.; Frieder, O.

2014-12-01

Generating big data pervades much of physics. But some problems, which we call extreme data problems, are too large to be treated within big data science. The nonequilibrium quantum many-body problem on a lattice is just such a problem, where the Hilbert space grows exponentially with system size and rapidly becomes too large to fit on any computer (and can be effectively thought of as an infinite-sized data set). Nevertheless, much progress has been made with computational methods on this problem, which serve as a paradigm for how one can approach and attack extreme data problems. In addition, viewing these physics problems from a computer-science perspective leads to new approaches that can be tried to solve more accurately and for longer times. We review a number of these different ideas here.

Shifts in the evolutionary rate and intensity of purifying selection between two Brassica genomes revealed by analyses of orthologous transposons and relics of a whole genome triplication.

PubMed

Zhao, Meixia; Du, Jianchang; Lin, Feng; Tong, Chaobo; Yu, Jingyin; Huang, Shunmou; Wang, Xiaowu; Liu, Shengyi; Ma, Jianxin

2013-10-01

Recent sequencing of the Brassica rapa and Brassica oleracea genomes revealed extremely contrasting genomic features such as the abundance and distribution of transposable elements between the two genomes. However, whether and how these structural differentiations may have influenced the evolutionary rates of the two genomes since their split from a common ancestor are unknown. Here, we investigated and compared the rates of nucleotide substitution between two long terminal repeats (LTRs) of individual orthologous LTR-retrotransposons, the rates of synonymous and non-synonymous substitution among triplicated genes retained in both genomes from a shared whole genome triplication event, and the rates of genetic recombination estimated/deduced by the comparison of physical and genetic distances along chromosomes and ratios of solo LTRs to intact elements. Overall, LTR sequences and genic sequences showed more rapid nucleotide substitution in B. rapa than in B. oleracea. Synonymous substitution of triplicated genes retained from a shared whole genome triplication was detected at higher rates in B. rapa than in B. oleracea. Interestingly, non-synonymous substitution was observed at lower rates in the former than in the latter, indicating shifted densities of purifying selection between the two genomes. In addition to evolutionary asymmetry, orthologous genes differentially regulated and/or disrupted by transposable elements between the two genomes were also characterized. Our analyses suggest that local genomic and epigenomic features, such as recombination rates and chromatin dynamics reshaped by independent proliferation of transposable elements and elimination between the two genomes, are perhaps partially the causes and partially the outcomes of the observed inter-specific asymmetric evolution. © 2013 Purdue University The Plant Journal © 2013 John Wiley & Sons Ltd.

Guidelines to Support Professional Copyright Practice

ERIC Educational Resources Information Center

Dryden, Jean

2012-01-01

Copyright is extremely complex, and it is difficult to convey its complexities in a clear and concise form. Through decades of experience, archivists developed informal best practices for dealing with copyright in the analog world; however the application of copyright in the digital environment is evolving in response to rapidly changing…

Assessment of Learning in Health Sciences Education: MLT Case Study

ERIC Educational Resources Information Center

Mugimu, Christopher Byalusaago; Mugisha, Wilson Rwandembo

2017-01-01

Assessment in health sciences education has become an extremely critical issue in recent years, given the rapidly changing disease patterns and behavioral changes in communities among diverse cultural and economic contexts of patients. Globally, there is increasing demand for highly qualified contemporary healthcare professionals. Subsequently,…

Standing Joint Forces: Spearhead for Global Operational Maneuver

DTIC Science & Technology

2005-05-26

Threat,” In The War Next Time: Countering Rogue States and Terrorists 1 20 NOVEMBER 2014 Operation Roundhouse was a resounding success. While...America’s " kick -down the door" force, capable of extremely rapid deployment from CONUS to anywhere in the world to ensure aerospace access for joint

Fuelwood Problems and Solutions

Treesearch

D. Evan Mercer; John Soussan

1992-01-01

Concern over the "fuelwood crisis" facing the world's poor has been widespread since the late 1970s (Eckholm et al. 1984; Soussan 1988; Agarwal 1986). At first the problem was frequently overstated. In the extreme, analysts (foresters, economists, and others) in many countries made erroneous projections of the rapid total destruction of the biomass...

Rocking in the Tree Tops

ERIC Educational Resources Information Center

Emery, Jill

2009-01-01

Twitter provides rapid information in a short form, and it is extremely easy to follow the updates of others because of myriad software applications with which it works on both mobile devices and traditional computing hardware. Currently, most academic librarians are using Twitter primarily as a tool at library conferences and seminars to capture…

Genetic basis for rapidly evolved tolerance in the wild: adaptation to toxic pollutants by an estuarine fish species

EPA Science Inventory

Atlantic killifish (Fundulus heteroclitus) residing in some urban and industrialized estuaries of the US eastern seaboard demonstrate recently evolved and extreme tolerance to toxic aryl hydrocarbon pollutants, characterized as dioxin-like compounds (DLCs). Here we provide an unu...

[Successful outcome of a pregnancy with an extremely low fetal heart rate (34 bpm) due to isolated complete heart block--case report].

PubMed

Hamela-Olkowska, Anita; Dangel, Joanna; Miszczak-Knecht, Maria

2009-09-01

Isolated complete congenital heart block (CHB) in the majority of cases is associated with the presence of autoantibodies to SSA (Ro) and SSB (La) antigens in the maternal serum. The prognosis is less favorable in fetuses with a ventricular rate < 55bpm. We have reported a case of a fetus with an isolated non-autoimmune CHB with an extremely low ventricular rate (34bpm) in which the outcome was favorable. In the neonate the non-compaction of the myocardium was diagnosed.

Alpine skiing injuries. A nine-year study.

PubMed Central

Davidson, T M; Laliotis, A T

1996-01-01

Injury patterns in alpine skiing have changed over time as ski, boot, binding, and slope-grooming technologies have evolved. We retrospectively examined injury patterns in alpine skiers over a 9-year period at the Mammoth and June mountains (California) ski area. A total of 24,340 injuries were reported for the 9 seasons studied, and total lift tickets sold numbered 9,201,486. The overall injury rate was 2.6 injuries per 1,000 skier days and increased slowly over the period studied. The knee was the most frequently injured area at 35% of all injuries. Increasing trends (P < .05) were noted for the rates of lower extremity injuries (37%) and knee injuries (45%). A decreasing trend was noted for the rate of lacerations (31% decrease). Slight increases were noted in upper extremity and axial injury rates. Skiing injuries continue to be a worrisome recreational problem despite improvements in ski equipment and slope-grooming techniques. The increasing trend in lower extremity, particularly knee, injury rates highlights the need for continued skier education and equipment innovation. PMID:8732730

Outcomes of lower extremity bypass performed for acute limb ischemia

PubMed Central

Baril, Donald T.; Patel, Virendra I.; Judelson, Dejah R.; Goodney, Philip P.; McPhee, James T.; Hevelone, Nathanael D.; Cronenwett, Jack L.; Schanzer, Andres

2013-01-01

Objective Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia. Methods All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year. Results Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation, deterioration in renal function, and respiratory complications. Patients who underwent lower extremity bypass for acute limb ischemia had no difference in rates of graft occlusion (18.1% vs 18.5%; P = .77), but did have significantly higher rates of limb loss (22.4% vs 9.7%; P < .0001) and mortality (20.9% vs 13.1%; P < .0001) at 1 year. On multivariable analysis, acute limb ischemia was an independent predictor of both major amputation (hazard ratio, 2.16; confidence interval, 1.38–3.40; P = .001) and mortality (hazard ratio, 1.41; confidence interval, 1.09–1.83; P = .009) at 1 year. Conclusions Patients who present with acute limb ischemia represent a less medically optimized subgroup within the population of patients undergoing lower extremity bypass. These patients may be expected to have more complex operations followed by increased rates of perioperative adverse events. Additionally, despite equivalent graft patency rates, patients undergoing lower extremity bypass for acute ischemia have significantly higher rates of major amputation and mortality at 1 year. PMID:23714364

Outcomes of lower extremity bypass performed for acute limb ischemia.

PubMed

Baril, Donald T; Patel, Virendra I; Judelson, Dejah R; Goodney, Philip P; McPhee, James T; Hevelone, Nathanael D; Cronenwett, Jack L; Schanzer, Andres

2013-10-01

Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia. All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year. Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation, deterioration in renal function, and respiratory complications. Patients who underwent lower extremity bypass for acute limb ischemia had no difference in rates of graft occlusion (18.1% vs 18.5%; P = .77), but did have significantly higher rates of limb loss (22.4% vs 9.7%; P < .0001) and mortality (20.9% vs 13.1%; P < .0001) at 1 year. On multivariable analysis, acute limb ischemia was an independent predictor of both major amputation (hazard ratio, 2.16; confidence interval, 1.38-3.40; P = .001) and mortality (hazard ratio, 1.41; confidence interval, 1.09-1.83; P = .009) at 1 year. Patients who present with acute limb ischemia represent a less medically optimized subgroup within the population of patients undergoing lower extremity bypass. These patients may be expected to have more complex operations followed by increased rates of perioperative adverse events. Additionally, despite equivalent graft patency rates, patients undergoing lower extremity bypass for acute ischemia have significantly higher rates of major amputation and mortality at 1 year. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.