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  1. The Last Class

    ERIC Educational Resources Information Center

    Uhl, Christopher

    2005-01-01

    The last class of the semester is like a goodbye. It can be cold and perfunctory or warm and heartfelt. For many years, I erred on the side of "cold and perfunctory." No more. Now my last classes are a time of celebration and ritual as I invite students to focus on qualities such as acceptance and gratitude.

  2. The last glacial termination.

    PubMed

    Denton, G H; Anderson, R F; Toggweiler, J R; Edwards, R L; Schaefer, J M; Putnam, A E

    2010-06-25

    A major puzzle of paleoclimatology is why, after a long interval of cooling climate, each late Quaternary ice age ended with a relatively short warming leg called a termination. We here offer a comprehensive hypothesis of how Earth emerged from the last global ice age. A prerequisite was the growth of very large Northern Hemisphere ice sheets, whose subsequent collapse created stadial conditions that disrupted global patterns of ocean and atmospheric circulation. The Southern Hemisphere westerlies shifted poleward during each northern stadial, producing pulses of ocean upwelling and warming that together accounted for much of the termination in the Southern Ocean and Antarctica. Rising atmospheric CO2 during southern upwelling pulses augmented warming during the last termination in both polar hemispheres. PMID:20576882

  3. Long lasting decontamination foam

    DOEpatents

    Demmer, Ricky L.; Peterman, Dean R.; Tripp, Julia L.; Cooper, David C.; Wright, Karen E.

    2010-12-07

    Compositions and methods for decontaminating surfaces are disclosed. More specifically, compositions and methods for decontamination using a composition capable of generating a long lasting foam are disclosed. Compositions may include a surfactant and gelatin and have a pH of less than about 6. Such compositions may further include affinity-shifting chemicals. Methods may include decontaminating a contaminated surface with a composition or a foam that may include a surfactant and gelatin and have a pH of less than about 6.

  4. Dad's Last Week.

    PubMed

    DeVoe, Jennifer E

    2016-05-01

    I had intended to spend our spring break week in Montana with my kids and my dad, going to parks and museums together. Instead, I spent the week in the hospital, helping my dad make end-of-life choices and learning more about the importance of communication in health care settings and the preciousness of close relationships in life. I am a better person and a better physician because my dad trusted me to be there while he was dying. During his last week, I was grateful to have spent years studying medicine and years getting to know my dad. This combination of professional and personal knowledge enabled me to help him choose his own end-of-life path. As someone who does not like hospitals, I have always wondered why I became a doctor; now I know. PMID:27185000

  5. The Iceman's last weeks

    NASA Astrophysics Data System (ADS)

    Spindler, Konrad

    1994-06-01

    The author presents the archaeological, botanical and anatomical of medical evidence relating to the events of the last few days of the Iceman's life. The unfinished arrows and the half-completed bow indicate that he had lost his weapons and was in the process of re-arming himself. The quiver and the two primed arrows show clear signs of damage that has been proved to originate from before entombment in the ice of Hauslabjoch. An intravital series of fractured ribs and atrophic changes to the humerus on the same side of the body are also indicative of a violent conflict. The presence of threshing and winnowing fragments proves that, shortly before his death, the Iceman spent some time in a human settlement in which the grain crop was threshed. The theory is therefore proposed that shortly before his death the Iceman suffered some personal catastrophe involving damage to his possessions and physical injury. He fled in the direction of the inner Ötz Valley, a region of high alpine pastures he may have been familiar with from summer transhumance. Just beyond the ridge of the main Alpine chain he was caught by a sudden fall in temperature and snowfall, which he did not survive.

  6. MEXFAM's 'The Last Train'.

    PubMed

    1988-01-01

    One of the short educational video programs produced by MEXFAM is called The Last Train, a love story of 2 teenagers which vividly describes the type of adolescent problems confronting Mexican society today. The film raises a number of questions which teenagers do not often consider. The objective of the film is to put in evidence the principles, myths, beliefs, omissions, and misinformation that exist between youth and adults regarding early genital urges. The movie aims to reach underprivileged urban youth between the ages of 11 and 20 years, as well as teachers and parents who are sensitive to youth's sex problems. MEXFAM emphasizes that the educational objective of the film should be pointed out to its audiences before it is shown. After the screening the main points recommended for discussion are: genital attraction, physical control, masturbation, virginity, and 1st sexual experience. MEXFAM also provides audiences with values sheets on which the participants are to write their reactions to certain situations in the film. PMID:12269064

  7. Last interglacial climates

    USGS Publications Warehouse

    Kukla, G.J.; Bender, M.L.; de Beaulieu, J. -L.; Bond, G.; Broecker, W.S.; Cleveringa, P.; Gavin, J.E.; Herbert, T.D.; Imbrie, J.; Jouzel, J.; Keigwin, L.D.; Knudsen, K.-L.; McManus, J.F.; Merkt, J.; Muhs, D.R.; Muller, H.; Poore, R.Z.; Porter, S.C.; Seret, G.; Shackleton, N.J.; Turner, C.; Tzedakis, P.C.; Winograd, I.J.

    2002-01-01

    The last interglacial, commonly understood as an interval with climate as warm or warmer than today, is represented by marine isotope stage (MIS) 5e, which is a proxy record of low global ice volume and high sea level. It is arbitrarily dated to begin at approximately 130,000 yr B.P. and end at 116,000 yr B.P. with the onset of the early glacial unit MIS 5d. The age of the stage is determined by correlation to uranium-thorium dates of raised coral reefs. The most detailed proxy record of interglacial climate is found in the Vostok ice core where the temperature reached current levels 132,000 yr ago and continued rising for another two millennia. Approximately 127,000 yr ago the Eemian mixed forests were established in Europe. They developed through a characteristic succession of tree species, probably surviving well into the early glacial stage in southern parts of Europe. After ca. 115,000 yr ago, open vegetation replaced forests in northwestern Europe and the proportion of conifers increased significantly farther south. Air temperature at Vostok dropped sharply. Pulses of cold water affected the northern North Atlantic already in late MIS 5e, but the central North Atlantic remained warm throughout most of MIS 5d. Model results show that the sea surface in the eastern tropical Pacific warmed when the ice grew and sea level dropped. The essentially interglacial conditions in southwestern Europe remained unaffected by ice buildup until late MIS 5d when the forests disappeared abruptly and cold water invaded the central North Atlantic ca. 107,000 yr ago. ?? 2002 University of Washington.

  8. Daedalus - Last Dryden flight

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The Daedalus 88, with Glenn Tremml piloting, is seen here on its last flight for the NASA Dryden Flight Research Center, Edwards, California. The Light Eagle and Daedalus human powered aircraft were testbeds for flight research conducted at Dryden between January 1987 and March 1988. These unique aircraft were designed and constructed by a group of students, professors, and alumni of the Massachusetts Institute of Technology within the context of the Daedalus project. The construction of the Light Eagle and Daedalus aircraft was funded primarily by the Anheuser Busch and United Technologies Corporations, respectively, with additional support from the Smithsonian Air and Space Museum, MIT, and a number of other sponsors. To celebrate the Greek myth of Daedalus, the man who constructed wings of wax and feathers to escape King Minos, the Daedalus project began with the goal of designing, building and testing a human-powered aircraft that could fly the mythical distance, 115 km. To achieve this goal, three aircraft were constructed. The Light Eagle was the prototype aircraft, weighing 92 pounds. On January 22, 1987, it set a closed course distance record of 59 km, which still stands. Also in January of 1987, the Light Eagle was powered by Lois McCallin to set the straight distance, the distance around a closed circuit, and the duration world records for the female division in human powered vehicles. Following this success, two more aircraft were built, the Daedalus 87 and Daedalus 88. Each aircraft weighed approximately 69 pounds. The Daedalus 88 aircraft was the ship that flew the 199 km from the Iraklion Air Force Base on Crete in the Mediterranean Sea, to the island of Santorini in 3 hours, 54 minutes. In the process, the aircraft set new records in distance and endurance for a human powered aircraft. The specific areas of flight research conducted at Dryden included characterizing the rigid body and flexible dynamics of the Light Eagle, investigating sensors for an

  9. Learning That Lasts: Field Guide

    ERIC Educational Resources Information Center

    Education Commission of the States, 2005

    2005-01-01

    This "Learning That Lasts Field Guide" is intended to trigger discussion about ways to integrate and sustain high-quality service-learning, as well as to provide a clearer path to finding and employing the information in the Education Commission of the States' (ECS) 2002 publication "Learning That Lasts: How Service-Learning Can Become an Integral…

  10. The last common bilaterian ancestor

    NASA Technical Reports Server (NTRS)

    Erwin, Douglas H.; Davidson, Eric H.

    2002-01-01

    Many regulatory genes appear to be utilized in at least superficially similar ways in the development of particular body parts in Drosophila and in chordates. These similarities have been widely interpreted as functional homologies, producing the conventional view of the last common protostome-deuterostome ancestor (PDA) as a complex organism that possessed some of the same body parts as modern bilaterians. Here we discuss an alternative view, in which the last common PDA had a less complex body plan than is frequently conceived. This reconstruction alters expectations for Neoproterozoic fossil remains that could illustrate the pathways of bilaterian evolution.

  11. Trouble Don't Last

    ERIC Educational Resources Information Center

    Pearsall, Shelley

    2004-01-01

    Even as a child, Pearsall questioned social injustice and prejudice. In her own community in Ohio and, as she grew, all over the world, she saw social inequities she could neither understand nor accept. Her novel "Trouble Don't Last," takes place during the era of the Underground Railroad. The chapter included here pulls us in immediately with a…

  12. Continuous Dust Formation in SNe 2010jl and 2011ja

    NASA Astrophysics Data System (ADS)

    Krafton, Kelsie; Clayton, Geoffrey; Andrews, Jennifer; Barlow, Michael; De Looze, Ilse

    2016-08-01

    Studies in the last 10 years of dust formation in core-collapse supernovae (CCSNe) have found only small amounts, ~0.001 solar masses. This is far less than the amount needed to account for the large masses of dust seen in some high redshift galaxies. However, the recent discovery of ~1 solar mass of cold dust in the ejecta of SN 1987A has has caused a complete re-evaluation of dust formation in CCSNe. It has been suggested that the CCSNe are continuously forming dust so that by the time they are about 25 years old they will have dust masses similar to SN 1987A. However, there is a wide time gap between the CCSNe that have been studied recently and SN 1987A. We plan to use the sensitivity of Spitzer to detect dust emission from CCSNe 5 or more years after explosion. Radiative transfer models will be used to estimate the dust masses. This proposal is to continue our study of two interesting SNe 2010jl and 2011ja. These observations are part of a long term study requiring multiple epochs of Spitzer observations to look for evidence of continuous dust formation. These observations will help shed light on the mystery of dust in SN 1987A.

  13. Sturckow Recaps Last Shuttle Landing at Edwards

    NASA Video Gallery

    When Space Shuttle Discovery touched down at Edwards Air Force Base in Southern California on Sept. 11, 2009 to conclude mission STS-128, no one foresaw that it would be the last of 54 such landing...

  14. Exercise Brings Bone Benefits that Last

    MedlinePlus

    ... External link, please review our exit disclaimer . Subscribe Exercise Brings Bone Benefits that Last Building bone as ... lose bone. Studies of animals have shown that exercise during periods of rapid growth can lead to ...

  15. The first/last access protocol

    NASA Astrophysics Data System (ADS)

    Karol, M. J.; Schwartz, S. C.

    When a random access protocol is used to share a communications channel, conflicts arising from simultaneous transmissions must be resolved. Listening to feedback on a broadcast channel, and using knowledge of round trip propagation delays, the First/Last Access Protocol (FLAP) reserves time for retransmissions of the 'first' and 'last' packets involved in a channel collision. Time slots of duration greater than a packet transmission time exploit the advantages of both slotted access protocols. The maximum achievable system throughput is 0.673 as the input rate increases. Extensions of FLAP yield system throughputs greater than 0.80.

  16. "The Last Waltz": Variations on a Theme.

    ERIC Educational Resources Information Center

    Aiex, Nola Kortner

    When the film "The Last Waltz" was released in 1978 the rock music press lost itself in comparisons of the performances of the rock group. The Band's many famous guest artists, while movie critics, for the most part, considered it only a concert film. Few critics saw the film as an integral part of director Martin Scorsese's continuing body of…

  17. The Last Class at Daniel's Creek.

    ERIC Educational Resources Information Center

    Rice, Russ

    1987-01-01

    Time and modern education caught up with the nine pupils of Daniel's Creek Elementary School, one of the last remaining one-room schoolhouses in Kentucky. The school was closed at the end of the 1986-87 school year by the county school board, after much opposition from a citizen's group. (JMM)

  18. The Professional's Last Will and Testament.

    ERIC Educational Resources Information Center

    Lancaster, James M.

    2003-01-01

    In this article a case study illustrates the initial issues arising from the sudden death of key personnel, and then offers an outline for the Professional's Last Will and Testament. This document includes attention to logistical issues and planning for organizational change. It begins with short-term transition issues and continues through other,…

  19. Myth of the "Last-In" Superstar

    ERIC Educational Resources Information Center

    Chesley, Gary M.; Hartman, Diane M.

    2011-01-01

    In the new political landscape, lawmakers in state after state are anxiously sponsoring legislation eliminating "last-in, first-out" policies. News reports would have people believe every untenured teacher, with just a few months of experience, is a "Teacher of the Year" candidate, while every tenured professional is a money-grabbing, lazy and…

  20. Optical networks, last mile access and applications

    NASA Astrophysics Data System (ADS)

    Leitgeb, E.; Gebhart, M.; Birnbacher, U.

    Free Space Optical (FSO) links can be used to setup FSO communication networks or to supplement radio and optical fiber networks. Hence, it is the broadband wireless solution for closing the "last mile" connectivity gap throughout metropolitan networks. Optical wireless fits well into dense urban areas and is ideally suited for urban applications. This paper gives an overview of free-space laser communications. Different network architectures will be described and investigated regarding reliability. The usage of "Optical Repeaters", Point-to-Point and Point-to-Multipoint solutions will be explained for setting up different network architectures. After having explained the different networking topologies and technologies, FSO applications will be discussed in section 2, including terrestrial applications for short and long ranges, and space applications. Terrestrial applications for short ranges cover the links between buildings on campus or different buildings of a company, which can be established with low-cost technology. For using FSO for long-range applications, more sophisticated systems have to be used. Hence, different techniques regarding emitted optical power, beam divergence, number of beams and tracking will be examined. Space applications have to be divided into FSO links through the troposphere, for example up- and downlinks between the Earth and satellites, and FSO links above the troposphere (e.g., optical inter-satellite links). The difference is that links through the troposphere are mainly influenced by weather conditions similar but not equal to terrestrial FSO links. Satellite orbits are above the atmosphere and therefore, optical inter-satellite links are not influenced by weather conditions. In section 3 the use of optical wireless for the last mile will be investigated and described in more detail. Therefore important design criteria for connecting the user to the "backbone" by FSO techniques will be covered, e.g., line of sight, network

  1. Design Documentation for JaWE2Openflow Project

    SciTech Connect

    Mehta, N; Barter, R H

    2004-07-29

    Lawrence Livermore National Laboratory (LLNL) has chosen CIGNEX Technologies, Inc. (CIGNEX) to design and develop the JaWE2Openflow conversion software. This document was created by CIGNEX as a project deliverable.

  2. RuBPCase activase mediates growth-defense tradeoffs: Silencing RCA redirects JA flux from JA-Ile to MeJA to attenuate induced defense responses in Nicotiana attenuata

    PubMed Central

    Mitra, Sirsha; Baldwin, Ian T.

    2014-01-01

    Summary RuBPCase activase (RCA), an abundant photosynthetic protein is strongly down-regulated in response to Manduca sexta’s oral secretion (OS) in Nicotiana attenuata. RCA-silenced plants are impaired not only in photosynthetic capacity and growth, but also in jasmonic acid (JA)-isoleucine (Ile) signaling, and herbivore resistance mediated by JA-Ile dependent defense traits. These responses are consistent with a resource-based growth-defense trade-off. Since JA+Ile-supplementation of OS restored WT levels of JA-Ile, defenses and resistance to M. sexta, but OS supplemented individually with JA- or Ile did not, the JA-Ile deficiency of RCA-silenced plants could not be attributed to lower JA or Ile pools or JAR4/6 conjugating activity. Similar levels of JA-Ile derivatives after OS elicitation indicated unaltered JA-Ile turnover and lower levels of other JA-conjugates ruled out competition from other conjugation reactions. RCA-silenced plants accumulated more methyl jasmonate (MeJA) after OS elicitation, which corresponded with increased jasmonate methyltransferase (JMT) activity. RCA-silencing phenocopies JMT over-expression, wherein elevated JMT activity redirects OS-elicited JA flux towards inactive MeJA, creating a JA sink which depletes JA-Ile and its associated defense responses. Hence RCA plays an additional non-photosynthetic role in attenuating JA-mediated defenses and their associated costs potentially allowing plants to anticipate resource-based constraints on growth before they actually occur. PMID:24491116

  3. Agents of Last Resort: Polymyxin Resistance.

    PubMed

    Kaye, Keith S; Pogue, Jason M; Tran, Thien B; Nation, Roger L; Li, Jian

    2016-06-01

    Polymyxin resistance is a major public health threat, as the polymyxins represent "last-line" therapeutics for Gram-negative pathogens resistant to essentially all other antibiotics. Improved understanding of mechanisms of, and risk factors for, polymyxin resistance, as well as infection prevention and stewardship strategies, together with optimization of dosing of polymyxins including in combination regimens, can help to limit the emergence and dissemination of polymyxin resistance. PMID:27208765

  4. Last Glacial loess in the conterminous USA

    USGS Publications Warehouse

    Bettis, E. Arthur, III; Muhs, Daniel R.; Roberts, Helen M.; Wintle, Ann G.

    2003-01-01

    The conterminous United States contains an extensive and generally well-studied record of Last Glacial loess. The loess occurs in diverse physiographic provinces, and under a wide range of climatic and ecological conditions. Both glacial and non-glacia lloess sources are present, and many properties of the loess vary systematically with distance from loess sources. United States' mid-continent Last Glacial loess is probably the thickest in the world, and our calculated mass accumulation rates (MARs) are as high as 17,500 g/m2/yr at the Bignell Hill locality in Nebraska, and many near-source localities have MARs greater than 1500 g/m2/yr. These MARs are high relative to rates calculated in other loess provinces around the world. Recent models of LastGlacial dust sources fail to predict the extent and magnitude of dust flux from the mid-continent of the United States. A better understanding of linkages between climate, ice sheet behaviour, routing of glacial meltwater, land surface processes beyond the ice margin, and vegetation is needed to improve the predictive capabilities of models simulating dust flux from this region.

  5. The last months of Andreas Vesalius.

    PubMed

    Biesbrouck, Maurits; Steeno, Omer

    2010-12-01

    A good deal has already been written about the last months of Andreas Vesalius' life. Most of it has been fairly speculative, because the necessary primary sources have been lacking. Much of what was supposedly known for sure seemed bizarre, and various writers even frankly characterised their own accounts as 'legend'. It is only since the discovery of several letters in the archives of Simancas by Josh Baron in 1962 that various points have become somewhat clearer. Baron presented these letters at the 19th International Congress on the History of Medicine in Basel in September 1964. PMID:21560612

  6. Martin Bergmann: The Last 21 Years.

    PubMed

    Feiner, Kenneth

    2015-06-01

    Martin Bergmann has contributed to our understanding of psychoanalysis for more than sixty years. A review of his contributions to psychoanalysis was completed in 1994, when Bergmann was 83 years old. Consideration of his remarkable productivity in the last twenty years clearly demonstrates the need to update this review. In these years, he extended his writing on the history of psychoanalysis, added to his contributions to an understanding of love, advanced ideas about psychoanalytic technique, and wrote two books on Shakespeare, as well as doing work in anthropology, sociology, literature, history, and religious studies. This paper reviews that work. PMID:26080097

  7. Atlantic hurricane activity during the last millennium

    NASA Astrophysics Data System (ADS)

    Burn, Michael J.; Palmer, Suzanne E.

    2015-08-01

    Hurricanes are a persistent socio-economic hazard for countries situated in and around the Main Development Region (MDR) of Atlantic tropical cyclones. Climate-model simulations have attributed their interdecadal variability to changes in solar and volcanic activity, Saharan dust flux, anthropogenic greenhouse gas and aerosol emissions and heat transport within the global ocean conveyor belt. However, the attribution of hurricane activity to specific forcing factors is hampered by the short observational record of Atlantic storms. Here, we present the Extended Hurricane Activity (EHA) index, the first empirical reconstruction of Atlantic tropical cyclone activity for the last millennium, derived from a high-resolution lake sediment geochemical record from Jamaica. The EHA correlates significantly with decadal changes in tropical Atlantic sea surface temperatures (SSTs; r = 0.68 1854-2008), the Accumulated Cyclone Energy index (ACE; r = 0.90 1851-2010), and two annually-resolved coral-based SST reconstructions (1773-2008) from within the MDR. Our results corroborate evidence for the increasing trend of hurricane activity during the Industrial Era; however, we show that contemporary activity has not exceeded the range of natural climate variability exhibited during the last millennium.

  8. Atlantic hurricane activity during the last millennium.

    PubMed

    Burn, Michael J; Palmer, Suzanne E

    2015-01-01

    Hurricanes are a persistent socio-economic hazard for countries situated in and around the Main Development Region (MDR) of Atlantic tropical cyclones. Climate-model simulations have attributed their interdecadal variability to changes in solar and volcanic activity, Saharan dust flux, anthropogenic greenhouse gas and aerosol emissions and heat transport within the global ocean conveyor belt. However, the attribution of hurricane activity to specific forcing factors is hampered by the short observational record of Atlantic storms. Here, we present the Extended Hurricane Activity (EHA) index, the first empirical reconstruction of Atlantic tropical cyclone activity for the last millennium, derived from a high-resolution lake sediment geochemical record from Jamaica. The EHA correlates significantly with decadal changes in tropical Atlantic sea surface temperatures (SSTs; r = 0.68; 1854-2008), the Accumulated Cyclone Energy index (ACE; r = 0.90; 1851-2010), and two annually-resolved coral-based SST reconstructions (1773-2008) from within the MDR. Our results corroborate evidence for the increasing trend of hurricane activity during the Industrial Era; however, we show that contemporary activity has not exceeded the range of natural climate variability exhibited during the last millennium. PMID:26243340

  9. [The last days of Albert Schweitzer].

    PubMed

    Wjst, Matthias

    2015-12-01

    Schweitzer was one of the leading physicians of the last century. He overcame not only the boundaries of humanities and natural sciences, but also the boundaries of Europe and Africa. He has become a symbol of humanity. But the person of Albert Schweitzer was almost in danger of disappearing behind it. "My hair starts to turn gray. My body begins to feel the exertions I have undertaken, and the burden of the years". This is how the 56-year-old Schweitzer ended his autobiography "Out of my life and thought" in 1931. Even 50 years after Schweitzer's death in 1965, there is still no coherent scientific reappraisal of his work. Part of the posthumous manuscripts was published in recent years in a critical edition, including first biographies that are no longer considered as hagiography, as they would have been in the contemporary literature. The legacy, however, is scattered. Much of the correspondence and the library are located in Schweitzer's former house in Gunsbach in Alsace. The manuscripts are mainly stored in the Central Library Zurich, but also in the Syracuse University New York, while the personal bequest is in the hands of his family or collectors. This presentation is part of a biographical approach and depicts the last weeks in the life of Albert Schweitzer. PMID:26676475

  10. Global sediment fluxes during the last millennium

    NASA Astrophysics Data System (ADS)

    Naipal, Victoria; Reick, Christian; Van Oost, Kristof; Hoffmann, Thomas; Pongratz, Julia

    2016-04-01

    Soil redistribution plays an important role in the transport of carbon and nutrients between terrestrial ecosystems. However, quantification of soil redistribution and its effects on the global biogeochemical cycles is currently unknown. This study aims at developing new tools and methods to represent soil redistribution on a global scale, and contribute to the quantification of anthropogenic disturbances to the biogeochemical cycles. We present a new large-scale coarse resolution sediment budget model that can simulate spatial patterns and long-term trends in soil redistribution in floodplains and on hillslope, resulting from external forces such as climate and land use change. First, we validated the model for the Rhine catchment using observed Holocene sediment storage data and observed scaling behavior between sediment storage and catchment area. Then, we applied the model on 20 large river catchments globally, using climate and land cover data from the Max Planck Institute Earth System Model (MPI-ESM) for the last millennium (850 - 2005AD). We show that the model can reproduce current observed sediment yields if uncertainty in the observations is taken into account. Furthermore, we find that the change in erosion rates during the last millennium resulted in a significant increase in sediment storage for different global catchments. We identify land use change as the main driver behind this change in sediment storage. Finally, catchments characteristics, such as area and slope, play an important role in buffering or amplifying the effect of land use and other external forces on the change in erosion and sediment storage.

  11. Global climate evolution during the last deglaciation.

    PubMed

    Clark, Peter U; Shakun, Jeremy D; Baker, Paul A; Bartlein, Patrick J; Brewer, Simon; Brook, Ed; Carlson, Anders E; Cheng, Hai; Kaufman, Darrell S; Liu, Zhengyu; Marchitto, Thomas M; Mix, Alan C; Morrill, Carrie; Otto-Bliesner, Bette L; Pahnke, Katharina; Russell, James M; Whitlock, Cathy; Adkins, Jess F; Blois, Jessica L; Clark, Jorie; Colman, Steven M; Curry, William B; Flower, Ben P; He, Feng; Johnson, Thomas C; Lynch-Stieglitz, Jean; Markgraf, Vera; McManus, Jerry; Mitrovica, Jerry X; Moreno, Patricio I; Williams, John W

    2012-05-01

    Deciphering the evolution of global climate from the end of the Last Glacial Maximum approximately 19 ka to the early Holocene 11 ka presents an outstanding opportunity for understanding the transient response of Earth's climate system to external and internal forcings. During this interval of global warming, the decay of ice sheets caused global mean sea level to rise by approximately 80 m; terrestrial and marine ecosystems experienced large disturbances and range shifts; perturbations to the carbon cycle resulted in a net release of the greenhouse gases CO(2) and CH(4) to the atmosphere; and changes in atmosphere and ocean circulation affected the global distribution and fluxes of water and heat. Here we summarize a major effort by the paleoclimate research community to characterize these changes through the development of well-dated, high-resolution records of the deep and intermediate ocean as well as surface climate. Our synthesis indicates that the superposition of two modes explains much of the variability in regional and global climate during the last deglaciation, with a strong association between the first mode and variations in greenhouse gases, and between the second mode and variations in the Atlantic meridional overturning circulation. PMID:22331892

  12. Atlantic hurricane activity during the last millennium

    PubMed Central

    Burn, Michael J.; Palmer, Suzanne E.

    2015-01-01

    Hurricanes are a persistent socio-economic hazard for countries situated in and around the Main Development Region (MDR) of Atlantic tropical cyclones. Climate-model simulations have attributed their interdecadal variability to changes in solar and volcanic activity, Saharan dust flux, anthropogenic greenhouse gas and aerosol emissions and heat transport within the global ocean conveyor belt. However, the attribution of hurricane activity to specific forcing factors is hampered by the short observational record of Atlantic storms. Here, we present the Extended Hurricane Activity (EHA) index, the first empirical reconstruction of Atlantic tropical cyclone activity for the last millennium, derived from a high-resolution lake sediment geochemical record from Jamaica. The EHA correlates significantly with decadal changes in tropical Atlantic sea surface temperatures (SSTs; r = 0.68; 1854–2008), the Accumulated Cyclone Energy index (ACE; r = 0.90; 1851–2010), and two annually-resolved coral-based SST reconstructions (1773–2008) from within the MDR. Our results corroborate evidence for the increasing trend of hurricane activity during the Industrial Era; however, we show that contemporary activity has not exceeded the range of natural climate variability exhibited during the last millennium. PMID:26243340

  13. Fluorescence imaging in the last two decades

    PubMed Central

    Miyawaki, Atsushi

    2013-01-01

    In commemoration of the 20th anniversary of the molecular cloning of the gene for the green fluorescent protein from the jellyfish Aequorea victoria, I would like to reflect on the development of new fluorescence imaging technology in the last two decades. As this technology has become increasingly diversified, it has become more and more of a challenge to come up with a comprehensive and exhaustive review of it. Here I will focus on optogenetics and large-scale, three-dimensional reconstruction. Those two technological innovations have been achieved in the neuroscience community owing to the combined efforts of molecular biologists and light microscopists. In addition, modern fluorescence imaging has indeed improved our understanding of the spatiotemporal regulation of fundamental biological functions at cellular level. As an example, I will introduce some findings we made regarding the movement of biomolecules across the nuclear membrane. The above-mentioned imaging approaches are possible today but were impossible two decades ago. PMID:23393311

  14. The lasting value of clinical skills.

    PubMed

    Kern, D C; Parrino, T A; Korst, D R

    1985-07-01

    To assess the lasting value of clinical skills learned by residents in a subspecialty-oriented training program in internal medicine, we surveyed recent graduates. Graduates received a questionnaire contrasting separate ratings of the amount of training (preparation) they received during residency with the importance of this training in subsequent career activities. Topics included 12 traditional medical disciplines, 15 areas related to the practice of medicine, 15 allied medical disciplines, ten basic skill and knowledge areas, and 28 technical procedures. Response rate was 91.8% (56/61). Ninety-five percent of respondents had certification from the American Board of Internal Medicine, 80% had subspecialty training, and 89% rendered direct patient care. Fifty-six topics showed disparity between preparation and importance scores (45 with P less than .0001). For 14 categories, mainly technical procedures, disparate ratings suggested excessive programmatic emphasis, while for 42 categories, including history taking and physical examination, there may have been inadequate emphasis. These data suggest that basic clinical skills may require greater emphasis, even in traditional programs. The opinion of program graduates is an important resource in designing training programs in internal medicine. PMID:3999353

  15. Metals at the surface of last scatter

    SciTech Connect

    Ali-Haiemoud, Yacine; Hirata, Christopher M.; Kamionkowski, Marc

    2011-04-15

    Standard big-bang nucleosynthesis (BBN) predicts only a trace abundance of lithium and no heavier elements, but some alternatives predict a nonzero primordial metallicity. Here we explore whether CMB measurements may set useful constraints to the primordial metallicity and/or whether the standard CMB calculations are robust, within the tolerance of forthcoming CMB maps, to the possibility of primordial metals. Metals would affect the recombination history (and thus CMB power spectra) in three ways: (1) Ly{alpha} photons can be removed (and recombination thus accelerated) by photoionizing metals; (2) The Bowen resonance-fluorescence mechanism may degrade Ly{beta} photons and thus enhance the Ly{beta} escape probability and speed up recombination; (3) Metals could affect the low-redshift tail of the CMB visibility function by providing additional free electrons. The last two of these provide the strongest CMB signal. However, the effects are detectable in the Planck satellite only if the primordial metal abundance is at least a few hundredths of solar for (2) and a few tenths of solar for (3). We thus conclude that Planck will not be able to improve upon current constraints to primordial metallicity, at the level of a thousandth of solar, from the Lyman-{alpha} forest and ultra-metal-poor halo stars, and that the CMB power-spectrum predictions for Planck suffer no uncertainty arising from the possibility that there may be primordial metals.

  16. Making lasting memories: Remembering the significant

    PubMed Central

    McGaugh, James L.

    2013-01-01

    Although forgetting is the common fate of most of our experiences, much evidence indicates that emotional arousal enhances the storage of memories, thus serving to create, selectively, lasting memories of our more important experiences. The neurobiological systems mediating emotional arousal and memory are very closely linked. The adrenal stress hormones epinephrine and corticosterone released by emotional arousal regulate the consolidation of long-term memory. The amygdala plays a critical role in mediating these stress hormone influences. The release of norepinephrine in the amygdala and the activation of noradrenergic receptors are essential for stress hormone-induced memory enhancement. The findings of both animal and human studies provide compelling evidence that stress-induced activation of the amygdala and its interactions with other brain regions involved in processing memory play a critical role in ensuring that emotionally significant experiences are well-remembered. Recent research has determined that some human subjects have highly superior autobiographic memory of their daily experiences and that there are structural differences in the brains of these subjects compared with the brains of subjects who do not have such memory. Understanding of neurobiological bases of such exceptional memory may provide additional insights into the processes underlying the selectivity of memory. PMID:23754441

  17. Guerrillero Heroico--a lasting impression.

    PubMed

    Shah, S H A; Clarke, T; Packer, J

    2011-06-01

    What once was simply a cultural tradition is fast becoming a popular phenomenon amongst Western tourists. Temporary henna tattoo designs performed by street or beach vendors are prevalent throughout the Middle East and Asia, particularly in holiday resorts. The public may be mistaken in thinking that the fashionable trend comes without significant risk. The main ingredient in the temporary tattooing method is henna (Lawsonia inermis), a flowering plant with dyeing properties that takes only several hours to be absorbed but provides an effect lasting around ten to fifteen days on the recipient's skin. The side effects of henna tattoos are well documented in the literature, although it is not clear whether the side effects directly relate to the henna ingredient or the additives used to prolong the designs. The most commonly noted complications include allergic contact dermatitis, infection, hypertrophic and keloid scarring and temporary or permanent hypo- or hyperpigmentation. In very rare cases, type 1 hypersensitivity reactions (angioedema and anaphylaxis) have been reported. The following case report highlights several of these complications and the relevant management. PMID:21030326

  18. Fermi's Paradox - The Last Challenge For Copernicanism?

    NASA Astrophysics Data System (ADS)

    Cirkovic, M. M.

    2009-06-01

    We review Fermi's paradox (or the "Great Silence" problem), not only arguably the oldest and crucial problem for the Search for ExtraTerrestrial Intelligence (SETI), but also a conundrum of profound scientific, philosophical and cultural importance. By a simple analysis of observation selection effects, the correct resolution of Fermi's paradox is certain to tell us something about the future of humanity. Already more than three quarters of century old puzzle -- and a quarter of century since the last major review paper in the field by G. David Brin -- has generated many ingenious discussions and hypotheses. We analyze the often tacit methodological assumptions built in various answers to this puzzle and attempt a new classification of the numerous solutions proposed in an already huge literature on the subject. Finally, we consider the ramifications of various classes of hypotheses for the practical SETI projects. Somewhat paradoxically, it seems that the class of (neo)catastrophic hypotheses gives, on the balance, the strongest justification to optimism regarding our current and near-future SETI efforts.

  19. Atmospheric methane evolution the last 40 years

    NASA Astrophysics Data System (ADS)

    Dalsøren, S. B.; Myhre, C. L.; Myhre, G.; Gomez-Pelaez, A. J.; Søvde, O. A.; Isaksen, I. S. A.; Weiss, R. F.; Harth, C. M.

    2015-11-01

    Observations at surface sites show an increase in global mean surface methane (CH4) of about 180 parts per billion (ppb) (above 10 %) over the period 1984-2012. Over this period there are large fluctuations in the annual growth rate. In this work, we investigate the atmospheric CH4 evolution over the period 1970-2012 with the Oslo CTM3 global Chemical Transport Model (CTM) in a bottom-up approach. We thoroughly assess data from surface measurement sites in international networks and select a subset suited for comparisons with the output from the CTM. We compare model results and observations to understand causes both for long-term trends and short-term variations. Employing the Oslo CTM3 model we are able to reproduce the seasonal and year to year variations and shifts between years with consecutive growth and stagnation, both at global and regional scales. The overall CH4 trend over the period is reproduced, but for some periods the model fails to reproduce the strength of the growth. The observed growth after 2006 is overestimated by the model in all regions. This seems to be explained by a too strong increase in anthropogenic emissions in Asia, having global impact. Our findings confirm other studies questioning the timing or strength of the emission changes in Asia in the EDGAR v4.2 emission inventory over the last decades. The evolution of CH4 is not only controlled by changes in sources, but also by changes in the chemical loss in the atmosphere and soil uptake. We model a large growth in atmospheric oxidation capacity over the period 1970-2012. In our simulations, the CH4 lifetime decreases by more than 8 % from 1970 to 2012, a significant shortening of the residence time of this important greenhouse gas. This results in substantial growth in the chemical CH4 loss (relative to its burden) and dampens the CH4 growth. The change in atmospheric oxidation capacity is driven by complex interactions between a number of chemical components and meteorological

  20. Last Days of Life (PDQ®)—Patient Version

    Cancer.gov

    Expert-reviewed information summary about care during the last days to last hours of life, including common symptoms, ethical dilemmas that may arise, and the role of the oncologist in caring for patients and their families during this time.

  1. Last Days of Life (PDQ®)—Health Professional Version

    Cancer.gov

    Expert-reviewed information summary about care during the last days to last hours of life, including common symptoms, ethical dilemmas that may arise, and the role of the oncologist in caring for patients and their families during this time.

  2. 39 CFR 777.27 - Last resort housing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Last resort housing. 777.27 Section 777.27 Postal Service UNITED STATES POSTAL SERVICE SPECIAL REGULATIONS RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION POLICIES Uniform Relocation Assistance § 777.27 Last resort housing. (a) Basic Determination to Provide Last Resort Housing. A...

  3. Coordinate expression of AOS genes and JA accumulation: JA is not required for initiation of closing layer in wound healing tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wounding induces a series of coordinated physiological responses essential for protection and healing of the damaged tissue. Wound-induced formation of jasmonic acid (JA) is important in defense responses in leaves, but comparatively little is known about the induction of JA biosynthesis and its ro...

  4. Modelling the thermosteric contribution to global and regional sea-level rise during the last interglacial

    NASA Astrophysics Data System (ADS)

    Singarayer, Joy; Stone, Emma; Whipple, Matthew; Lunt, Dan; Bouttes, Nathaelle; Gregory, Jonathan

    2014-05-01

    Global sea level during the last interglacial is likely to have been between 5.5 and 9m above present (Dutton and Lambeck, 2012). Recent calculations, taking into account latest NEEM ice core information, suggest that Greenland would probably not have contributed more than 2.2m to this (Stone et al, 2013), implying a considerable contribution from Antarctica. Previous studies have suggested a significant loss from the West Antarctic ice-sheet (e.g. Holden et al, 2010), which could be initiated following a collapse of the Atlantic Meridional Overturning Circulation (AMOC) and resultant warming in the Southern Ocean. Here, model simulations with FAMOUS and HadCM3 have been performed of the last interglacial under various scenarios of reduced Greenland and Antarctic ice-sheet configurations, and with and without collapsed AMOC. Thermal expansion and changes in regional density structure (resulting from ocean circulation changes) can also influence sea level, in addition to ice mass effects discussed thus far. The HadCM3 and FAMOUS simulations will be used to estimate the contribution to global and regional sea level change in interglacials from the latter two factors using a similar methodology to the IPCC TAR/AR4 estimations of future sea level rise (Gregory and Lowe, 2000). The HadCM3 and FAMOUS both have a rigid lid in their ocean model, and consequently a fixed ocean volume. Thermal expansion can, however, be calculated as a volume change from in-situ density (a prognostic variable from the model). Relative sea surface topography will then be estimated from surface pressure gradients and changes in atmospheric pressure. Dutton A., and Lambeck K., 2013. Ice Volume and Sea Level During the Last Interglacial. Science, 337, 216-219 Gregory J.M. and Lowe J.A., 2000. Predictions of global and regional sea-level using AOGCMs with and without flux adjustment. GRL, 27, 3069-3072 Holden P. et al., 2010. Interhemispheric coupling, the West Antarctic Ice Sheet and warm

  5. Effect of MeJA treatment on polyamine, energy status and anthracnose rot of loquat fruit.

    PubMed

    Cao, Shifeng; Cai, Yuting; Yang, Zhenfeng; Joyce, Daryl C; Zheng, Yonghua

    2014-02-15

    The effect of methyl jasmonate (MeJA) on changes in polyamines content and energy status and their relation to disease resistance was investigated. Freshly harvested loquat fruit were treated with 10 μmol l(-1) MeJA and wound inoculated with Colletotrichum acutatum spore suspension (1.0 × 10(5) spores ml(-1)) after 24h, and then stored at 20 °C for 6 days. MeJA treatment significantly reduced decay incidence. MeJA treated fruit manifested higher contents of polyamines (putrescine, spermidine and spermine) compared with the control fruit, during storage. MeJA treatment also maintained higher levels of adenosine triphosphate, and suppressed an increase in adenosine monophosphate content in loquat fruit. These results suggest that MeJA treatment may inhibit anthracnose rot by increasing polyamine content and maintaining the energy status. PMID:24128452

  6. Legislatures Reconvene with Last Year's Battles Still in Mind

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2012-01-01

    As state legislatures go to work this year, one of the overriding questions is whether 2012 will bring a reprise of last year's frenzied work on education--much of it shepherded by newly elected Republican majorities and governors--or whether elected officials will take a more deliberate and cautious approach. Last year, many governors and…

  7. 39 CFR 777.27 - Last resort housing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Last resort housing. 777.27 Section 777.27 Postal Service UNITED STATES POSTAL SERVICE SPECIAL REGULATIONS RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION POLICIES Uniform Relocation Assistance § 777.27 Last resort housing. (a) Basic Determination...

  8. 39 CFR 777.27 - Last resort housing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Last resort housing. 777.27 Section 777.27 Postal Service UNITED STATES POSTAL SERVICE SPECIAL REGULATIONS RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION POLICIES Uniform Relocation Assistance § 777.27 Last resort housing. (a) Basic Determination...

  9. 39 CFR 777.27 - Last resort housing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Last resort housing. 777.27 Section 777.27 Postal Service UNITED STATES POSTAL SERVICE SPECIAL REGULATIONS RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION POLICIES Uniform Relocation Assistance § 777.27 Last resort housing. (a) Basic Determination...

  10. Synthesis, structural characterization and biological activity of two diastereomeric JA-Ile macrolactones.

    PubMed

    Jimenez-Aleman, Guillermo H; Machado, Ricardo A R; Görls, Helmar; Baldwin, Ian T; Boland, Wilhelm

    2015-06-01

    Jasmonates are phytohormones involved in a wide range of plant processes, including growth, development, senescence, and defense. Jasmonoyl-L-isoleucine (JA-Ile, 2), an amino acid conjugate of jasmonic acid (JA, 1), has been identified as a bioactive endogenous jasmonate. However, JA-Ile (2) analogues trigger different responses in the plant. ω-Hydroxylation of the pentenyl side chain leads to the inactive 12-OH-JA-Ile (3) acting as a “stop” signal. On the other hand, a lactone derivative of 12-OH-JA (5) (jasmine ketolactone, JKL) occurs in nature, although with no known biological function. Inspired by the chemical structure of JKL (6) and in order to further explore the potential biological activities of 12-modified JA-Ile derivatives, we synthesized two macrolactones (JA-Ile-lactones (4a) and (4b)) derived from 12-OH-JA-Ile (3). The biological activity of (4a) and (4b) was tested for their ability to elicit nicotine production, a well-known jasmonate dependent secondary metabolite. Both macrolactones showed strong biological activity, inducing nicotine accumulation to a similar extent as methyl jasmonate does in Nicotiana attenuata leaves. Surprisingly, the highest nicotine contents were found in plants treated with the JA-Ile-lactone (4b), which has (3S,7S) configuration at the cyclopentanone not known from natural jasmonates. Macrolactone (4a) is a valuable standard to explore for its occurrence in nature. PMID:25806705

  11. The mealybug Phenacoccus solenopsis suppresses plant defense responses by manipulating JA-SA crosstalk

    PubMed Central

    Zhang, Peng-Jun; Huang, Fang; Zhang, Jin-Ming; Wei, Jia-Ning; Lu, Yao-Bin

    2015-01-01

    Induced plant defenses against herbivores are modulated by jasmonic acid-, salicylic acid-, and ethylene-signaling pathways. Although there is evidence that some pathogens suppress plant defenses by interfering with the crosstalk between different signaling pathways, such evidence is scarce for herbivores. Here, we demonstrate that the mealybug Phenacoccus solenopsis suppresses the induced defenses in tomato. We found that exogenous JA, but not SA, significantly decreased mealybug feeding time and reduced nymphal performance. In addition, constitutive activation of JA signaling in 35s::prosys plants reduced mealybug survival. These data indicate that the JA signaling pathway plays a key role in mediating the defense responses against P. solenopsis. We also found that mealybug feeding decreased JA production and JA-dependent defense gene expression, but increased SA accumulation and SA-dependent gene expression. In SA-deficient plants, mealybug feeding did not suppress but activated JA accumulation, indicating that the suppression of JA-regulated defenses depends on the SA signaling pathway. Mealybugs benefit from suppression of JA-regulated defenses by exhibiting enhanced nymphal performance. These findings confirm that P. solenopsis manipulates plants for its own benefits by modulating the JA-SA crosstalk and thereby suppressing induced defenses. PMID:25790868

  12. Gulf of Mexico dead zone - the last 150 years

    USGS Publications Warehouse

    Osterman, Lisa; Swarzenski, P.W.; Poore, R.Z.

    2006-01-01

    'Gulf of Mexico Dead Zone-The Last 150 Years' discusses the dead zone that forms seasonally in the northern Gulf of Mexico when subsurface waters become depleted in dissolved oxygen and cannot support most life.

  13. 99. DETAIL OF TYPICAL METER ADJUST PANELS LOCATED IN LAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    99. DETAIL OF TYPICAL METER ADJUST PANELS LOCATED IN LAST TWO CABINETS ON RIGHT IN CA-133-1-A-97 - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  14. Intact and long-lasting repetition priming in amnesia.

    PubMed

    Cave, C B; Squire, L R

    1992-05-01

    In 2 experiments, we evaluated the ability of amnesic patients to exhibit long-lasting perceptual priming after a single exposure to pictures. Ss named pictures as quickly as possible on a single occasion, and later named the same pictures mixed with new pictures. In Experiment 1, amnesic patients exhibited fully intact priming effects lasting at least 7 days. In Experiment 2, the priming effect for both groups was shown to depend on both highly specific visual information and on less visual, more conceptual information. In contrast, recognition memory was severely impaired in the patients, as assessed by both accuracy and response time. The results provide the first report of a long-lasting priming effect in amnesic patients, based on a single encounter, which occurs as strongly in the patients as in normal Ss. Together with other recent findings, the results suggest that long-lasting priming and recognition memory depend on separate brain systems. PMID:1534352

  15. View facing northeast of Structure 1034, last numbered structure on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View facing northeast of Structure 103-4, last numbered structure on northern (Havre) end of Transmission Line - Havre Rainbow Transmission Line, Havre City to Great Falls vicinity, Montana, Great Falls, Cascade County, MT

  16. Colorful Demos with a Long-Lasting Soap Bubble.

    ERIC Educational Resources Information Center

    Behroozi, F.; Olson, D. W.

    1994-01-01

    Describes several demonstrations that feature interaction of light with soap bubbles. Includes directions about how to produce a long-lasting stationary soap bubble with an easily changeable size and describes the interaction of white light with the bubble. (DDR)

  17. At last, a medical website designed for grown-ups

    MedlinePlus

    ... At last, a medical website designed for grown-ups Past Issues / Winter 2007 Table of Contents For ... U.S. Department of Health and Human Services. For up-to-date health information tailor-made just for ...

  18. 1. Historic American Buildings Survey (Sold by Anita Pacheco last ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey (Sold by Anita Pacheco last owner of Pacheco Estate 8 years ago. Now owned by Pentecost Church Society. YEAR BUILT: 1830 - Salvio Pancheco Adobe, 2030 Adobe Street, Concord, Contra Costa County, CA

  19. Early local last glacial maximum in the tropical Andes.

    PubMed

    Smith, Jacqueline A; Seltzer, Geoffrey O; Farber, Daniel L; Rodbell, Donald T; Finkel, Robert C

    2005-04-29

    The local last glacial maximum in the tropical Andes was earlier and less extensive than previously thought, based on 106 cosmogenic ages (from beryllium-10 dating) from moraines in Peru and Bolivia. Glaciers reached their greatest extent in the last glacial cycle approximately 34,000 years before the present and were retreating by approximately 21,000 years before the present, implying that tropical controls on ice volumes were asynchronous with those in the Northern Hemisphere. Our estimates of snowline depression reflect about half the temperature change indicated by previous widely cited figures, which helps resolve the discrepancy between estimates of terrestrial and marine temperature depression during the last glacial cycle. PMID:15860623

  20. Atlantic meridional overturning circulation during the Last Glacial Maximum.

    PubMed

    Lynch-Stieglitz, Jean; Adkins, Jess F; Curry, William B; Dokken, Trond; Hall, Ian R; Herguera, Juan Carlos; Hirschi, Joël J-M; Ivanova, Elena V; Kissel, Catherine; Marchal, Olivier; Marchitto, Thomas M; McCave, I Nicholas; McManus, Jerry F; Mulitza, Stefan; Ninnemann, Ulysses; Peeters, Frank; Yu, Ein-Fen; Zahn, Rainer

    2007-04-01

    The circulation of the deep Atlantic Ocean during the height of the last ice age appears to have been quite different from today. We review observations implying that Atlantic meridional overturning circulation during the Last Glacial Maximum was neither extremely sluggish nor an enhanced version of present-day circulation. The distribution of the decay products of uranium in sediments is consistent with a residence time for deep waters in the Atlantic only slightly greater than today. However, evidence from multiple water-mass tracers supports a different distribution of deep-water properties, including density, which is dynamically linked to circulation. PMID:17412948

  1. Maize MeJA-responsive proteins identified by high-resolution 2-DE PAGE.

    PubMed

    Zhang, Yuliang; Pennerman, Kayla K; Yang, Fengshan; Yin, Guohua

    2015-12-01

    Exogenous methyl jasmonate (MeJA) is well-known to induce plant defense mechanisms effective against a wide variety of insect and microbial pests. High-resolution 2-DE gel electrophoresis was used to discover changes in the leaf proteome of maize exposed to MeJA. We sequenced 62 MeJA-responsive proteins by tandem mass spectroscopy, and deposited the mass spectra and identities in the EMBL-EBI PRIDE repository under reference number PXD001793. An analysis and discussion of the identified proteins in relation to maize defense against Asian corn borer is published by Zhang et al. (2015) [1]. PMID:26509185

  2. Taking Successful Programs to Scale and Creating Lasting Results

    ERIC Educational Resources Information Center

    National Math and Science Initiative, 2008

    2008-01-01

    Scaling Effective Programs is a category of giving that is quite unique. Philanthropists have many different interests that guide their giving, but Scaling Effective Programs offers an approach that can produce lasting transformation. This guide speaks to funders who: (1) view their giving as venture capital that stimulates other giving; (2) want…

  3. B. F. Skinner--The Last Few Days.

    ERIC Educational Resources Information Center

    Vargas, Julie S.

    1990-01-01

    The daughter of Burrhus Frederic Skinner writes of her father's activities during the last few days of his life--his speech upon receipt of an award from the American Psychological Association, his work on research papers and books, interviews, and his final admission to the hospital where he died. (JDD)

  4. Interior, detail view of last original windows and filed in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior, detail view of last original windows and filed in wall arches, also concrete block wall of beryllum/uranium labs to left, looking southwest near center of west elevation, main building. - Watertown Arsenal, Building No. 312, Wooley Avenue, Watertown, Middlesex County, MA

  5. The Last 40 Years in Finnish Teacher Education

    ERIC Educational Resources Information Center

    Tirri, Kirsi

    2014-01-01

    This article sets out to identify and discuss the changes that have taken place in Finnish teacher education during the last 40 years (1974-2014). A brief history of teacher education in Finland is presented, followed by the goals and aims of current research-based teacher education in Finland. Finally, the major changes in Finnish teacher…

  6. 44. From hilltop, Route 14, last segment of flume before ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. From hilltop, Route 14, last segment of flume before Broughton Lumber Company. Section of flume, BNSF tracks, Highway 14 and Columbia River. South/southwest 220 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  7. Reductions in potash for last-year alfalfa production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Applying the correct amount of potassium (K) fertilizer is critical for alfalfa yield and stand persistence; however, excess K fertilizer will decrease profits and increase the risk of milk fever when alfalfa is fed to fresh cows. Stand persistence is often not a major concern in the last year of al...

  8. 34 CFR 303.527 - Payor of last resort.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Payor of last resort. 303.527 Section 303.527 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION EARLY INTERVENTION PROGRAM FOR INFANTS AND TODDLERS...

  9. 34 CFR 303.126 - Payor of last resort.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Payor of last resort. 303.126 Section 303.126 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION EARLY INTERVENTION PROGRAM FOR INFANTS AND TODDLERS...

  10. Creating Lasting Behavioral Change through the Generalization Analysis Worksheet

    ERIC Educational Resources Information Center

    Brady, John; Kotkin, Ron

    2011-01-01

    The goal of any behavioral program is to facilitate lasting change. A significant criticism of behavioral programs is that they work in the clinical setting but do not generalize once the clinical program is stopped. The authors suggest that behavioral programs often do not generalize because clinicians fail to plan for generalization to occur…

  11. Fermat's Last Theorem for Factional and Irrational Exponents

    ERIC Educational Resources Information Center

    Morgan, Frank

    2010-01-01

    Fermat's Last Theorem says that for integers n greater than 2, there are no solutions to x[superscript n] + y[superscript n] = z[superscript n] among positive integers. What about rational exponents? Irrational n? Negative n? See what an undergraduate senior seminar discovered.

  12. 49 CFR 24.404 - Replacement housing of last resort.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... method selected for providing last resort housing assistance is cost effective, considering all elements, which contribute to total program or project costs. (b) Basic rights of persons to be displaced... reasonable cost, on a case-by-case basis unless an exception to case-by-case analysis is justified for...

  13. 39 CFR 777.27 - Last resort housing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... rehabilitation of a replacement dwelling. (6) The purchase or lease of land and/or a replacement dwelling by the... a reasonable cost basis. The Postal Service may provide last resort housing using the following methods: (1) Rehabilitation of and/or additions to an existing replacement dwelling. (2) The...

  14. "Life after Last Orders": Microbiology as a Career

    ERIC Educational Resources Information Center

    Verran, Joanna

    2004-01-01

    The 2003 conference of the International Biodegradation and Biodeterioration Society (www.biodeterioration. org) and the International Biodegradation Research Group (www.ibrg.org), was held last September at the Manchester Metropolitan University. The conference, "Management and Control of Undesirable Microorganisms", followed the usual format of…

  15. 49 CFR 24.404 - Replacement housing of last resort.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Replacement housing of last resort. 24.404 Section 24.404 Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Replacement Housing Payments §...

  16. 49 CFR 24.404 - Replacement housing of last resort.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Replacement housing of last resort. 24.404 Section 24.404 Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Replacement Housing Payments §...

  17. 49 CFR 24.404 - Replacement housing of last resort.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Replacement housing of last resort. 24.404 Section 24.404 Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Replacement Housing Payments §...

  18. Mutations in jasmonoyl-L-isoleucine-12-hydroxylases suppress multiple JA-dependent wound responses in Arabidopsis thaliana.

    PubMed

    Poudel, Arati N; Zhang, Tong; Kwasniewski, Misha; Nakabayashi, Ryo; Saito, Kazuki; Koo, Abraham J

    2016-09-01

    Plants rapidly perceive tissue damage, such as that inflicted by insects, and activate several key defense responses. The importance of the fatty acid-derived hormone jasmonates (JA) in dictating these wound responses has been recognized for many years. However, important features pertaining to the regulation of the JA pathway are still not well understood. One key unknown is the inactivation mechanism of the JA pathway and its relationship with plant response to wounding. Arabidopsis cytochrome P450 enzymes in the CYP94 clade metabolize jasmonoyl-L-isoleucine (JA-Ile), a major metabolite of JA responsible for many biological effects attributed to the JA signaling pathway; thus, CYP94s are expected to contribute to the attenuation of JA-Ile-dependent wound responses. To directly test this, we created the double and triple knock-out mutants of three CYP94 genes, CYP94B1, CYP94B3, and CYP94C1. The mutations blocked the oxidation steps and caused JA-Ile to accumulate 3-4-fold the WT levels in the wounded leaves. Surprisingly, over accumulation of JA-Ile did not lead to a stronger wound response. On the contrary, the mutants displayed a series of symptoms reminiscent of JA-Ile deficiency, including resistance to wound-induced growth inhibition, decreased anthocyanin and trichomes, and increased susceptibility to insects. The mutants, however, responded normally to exogenous JA treatments, indicating that JA perception or signaling pathways were intact. Untargeted metabolite analyses revealed >40% reduction in wound-inducible metabolites in the mutants. These observations raise questions about the current JA signaling model and point toward a more complex model perhaps involving JA derivatives and/or feedback mechanisms. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:26968098

  19. A last updating evolution model for online social networks

    NASA Astrophysics Data System (ADS)

    Bu, Zhan; Xia, Zhengyou; Wang, Jiandong; Zhang, Chengcui

    2013-05-01

    As information technology has advanced, people are turning to electronic media more frequently for communication, and social relationships are increasingly found on online channels. However, there is very limited knowledge about the actual evolution of the online social networks. In this paper, we propose and study a novel evolution network model with the new concept of “last updating time”, which exists in many real-life online social networks. The last updating evolution network model can maintain the robustness of scale-free networks and can improve the network reliance against intentional attacks. What is more, we also found that it has the “small-world effect”, which is the inherent property of most social networks. Simulation experiment based on this model show that the results and the real-life data are consistent, which means that our model is valid.

  20. AMPARs and Synaptic Plasticity: The Last 25 Years

    PubMed Central

    Huganir, Richard L.; Nicoll, Roger A.

    2014-01-01

    The study of synaptic plasticity and specifically LTP and LTD is one of the most active areas of research in neuroscience. In the last 25 years we have come a long way in our understanding of the mechanisms underlying synaptic plasticity. In 1988, AMPA and NMDA receptors were not even molecularly identified and we only had a simple model of the minimal requirements for the induction of plasticity. It is now clear that the modulation of the AMPA receptor function and membrane trafficking is critical for many forms of synaptic plasticity and a large number of proteins have been identified that regulate this complex process. Here we review the progress over the last two and a half decades and discuss the future challenges in the field. PMID:24183021

  1. North Atlantic Deep Water Production during the Last Glacial Maximum

    PubMed Central

    Howe, Jacob N. W.; Piotrowski, Alexander M.; Noble, Taryn L.; Mulitza, Stefan; Chiessi, Cristiano M.; Bayon, Germain

    2016-01-01

    Changes in deep ocean ventilation are commonly invoked as the primary cause of lower glacial atmospheric CO2. The water mass structure of the glacial deep Atlantic Ocean and the mechanism by which it may have sequestered carbon remain elusive. Here we present neodymium isotope measurements from cores throughout the Atlantic that reveal glacial–interglacial changes in water mass distributions. These results demonstrate the sustained production of North Atlantic Deep Water under glacial conditions, indicating that southern-sourced waters were not as spatially extensive during the Last Glacial Maximum as previously believed. We demonstrate that the depleted glacial δ13C values in the deep Atlantic Ocean cannot be explained solely by water mass source changes. A greater amount of respired carbon, therefore, must have been stored in the abyssal Atlantic during the Last Glacial Maximum. We infer that this was achieved by a sluggish deep overturning cell, comprised of well-mixed northern- and southern-sourced waters. PMID:27256826

  2. North Atlantic Deep Water Production during the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Howe, Jacob N. W.; Piotrowski, Alexander M.; Noble, Taryn L.; Mulitza, Stefan; Chiessi, Cristiano M.; Bayon, Germain

    2016-06-01

    Changes in deep ocean ventilation are commonly invoked as the primary cause of lower glacial atmospheric CO2. The water mass structure of the glacial deep Atlantic Ocean and the mechanism by which it may have sequestered carbon remain elusive. Here we present neodymium isotope measurements from cores throughout the Atlantic that reveal glacial-interglacial changes in water mass distributions. These results demonstrate the sustained production of North Atlantic Deep Water under glacial conditions, indicating that southern-sourced waters were not as spatially extensive during the Last Glacial Maximum as previously believed. We demonstrate that the depleted glacial δ13C values in the deep Atlantic Ocean cannot be explained solely by water mass source changes. A greater amount of respired carbon, therefore, must have been stored in the abyssal Atlantic during the Last Glacial Maximum. We infer that this was achieved by a sluggish deep overturning cell, comprised of well-mixed northern- and southern-sourced waters.

  3. North Atlantic Deep Water Production during the Last Glacial Maximum.

    PubMed

    Howe, Jacob N W; Piotrowski, Alexander M; Noble, Taryn L; Mulitza, Stefan; Chiessi, Cristiano M; Bayon, Germain

    2016-01-01

    Changes in deep ocean ventilation are commonly invoked as the primary cause of lower glacial atmospheric CO2. The water mass structure of the glacial deep Atlantic Ocean and the mechanism by which it may have sequestered carbon remain elusive. Here we present neodymium isotope measurements from cores throughout the Atlantic that reveal glacial-interglacial changes in water mass distributions. These results demonstrate the sustained production of North Atlantic Deep Water under glacial conditions, indicating that southern-sourced waters were not as spatially extensive during the Last Glacial Maximum as previously believed. We demonstrate that the depleted glacial δ(13)C values in the deep Atlantic Ocean cannot be explained solely by water mass source changes. A greater amount of respired carbon, therefore, must have been stored in the abyssal Atlantic during the Last Glacial Maximum. We infer that this was achieved by a sluggish deep overturning cell, comprised of well-mixed northern- and southern-sourced waters. PMID:27256826

  4. Vaccine refusal and the endgame: walking the last mile first

    PubMed Central

    Saint-Victor, Diane S.; Omer, Saad B.

    2013-01-01

    As multiple papers within this special issue illustrate, the dynamics of disease eradication are different from disease control. When it comes to disease eradication, ‘the last mile is longest’. For social and ecological reasons such as vaccine refusal, further ending incidence of a disease when it has reached low levels is frequently complex. Issues of non-compliance within a target population often influence the outcome of disease eradication efforts. Past eradication efforts confronted such obstacles towards the tail end of the campaign, when disease incidence was lowest. This article provides a comparison of non-compliance within polio, measles and smallpox campaigns, demonstrating the tendency of vaccine refusal to rise as disease incidence falls. In order to overcome one of the most intractable challenges to eradication, future disease eradication efforts must prioritize vaccine refusal from the start, i.e. ‘walk the last mile first’. PMID:23798696

  5. Interhemispheric Atlantic seesaw response during the last deglaciation.

    PubMed

    Barker, Stephen; Diz, Paula; Vautravers, Maryline J; Pike, Jennifer; Knorr, Gregor; Hall, Ian R; Broecker, Wallace S

    2009-02-26

    The asynchronous relationship between millennial-scale temperature changes over Greenland and Antarctica during the last glacial period has led to the notion of a bipolar seesaw which acts to redistribute heat depending on the state of meridional overturning circulation within the Atlantic Ocean. Here we present new records from the South Atlantic that show rapid changes during the last deglaciation that were instantaneous (within dating uncertainty) and of opposite sign to those observed in the North Atlantic. Our results demonstrate a direct link between the abrupt changes associated with variations in the Atlantic meridional overturning circulation and the more gradual adjustments characteristic of the Southern Ocean. These results emphasize the importance of the Southern Ocean for the development and transmission of millennial-scale climate variability and highlight its role in deglacial climate change and the associated rise in atmospheric carbon dioxide. PMID:19242468

  6. Mineralogy of the last lunar basalts: Results from Clementine

    USGS Publications Warehouse

    Staid, M.I.; Pieters, C.M.

    2001-01-01

    The last major phase of lunar volcanism produced extensive high-titanium mare deposits on the western nearside which remain unsampled by landing missions. The visible and near-infrared reflectance properties of these basalts are examined using Clementine multispectral images to better constrain their mineralogy. A much stronger 1 ??m ferrous absorption was observed for the western high-titanium basalts than within earlier maria, suggesting that these last major mare eruptions also may have been the most iron-rich. These western basalts also have a distinctly long-wavelength, 1 ??m ferrous absorption which was found to be similar for both surface soils and materials excavated from depth, supporting the interpretation of abundant olivine within these deposits. Spectral variation along flows within the Imbrium basin also suggests variations in ilmenite content along previously mapped lava flows as well as increasing olivine content within subsequent eruptions. Copyright 2001 by the American Geophysical Union.

  7. Solar activity and climate during the last millennium

    NASA Astrophysics Data System (ADS)

    Solanki, S. K.; Usoskin, I.; Schüssler, M.

    The sunspot number is the longest running direct index of solar activity, with direct measurements starting in 1610. For many purposes, e.g., for comparisons with climate indices, it is still too short. We present a reconstruction of the cycle-averaged sunspot number over the last millennium based on 10Be concentrations in Greenland and Antarctic ice cores. As intermediate steps of the method, we also reconstruct the cosmic ray flux at Earth and the Sun's open magnetic flux. The reconstructions are validated by comparison with direct measurements or independent reconstructions. We also compare with records of global climate, in particular with the global temperature ("hockey stick") curve of Mann et al (1998). A reasonable agreement is found for the entire millennium, excluding only the last decades, when the two curves start diverging from each other.

  8. Ocean Cooling Pattern at the Last Glacial Maximum

    DOE PAGESBeta

    Zhuang, Kelin; Giardino, John R.

    2012-01-01

    Ocean temperature and ocean heat content change are analyzed based on four PMIP3 model results at the Last Glacial Maximum relative to the prehistorical run. Ocean cooling mostly occurs in the upper 1000 m depth and varies spatially in the tropical and temperate zones. The Atlantic Ocean experiences greater cooling than the rest of the ocean basins. Ocean cooling is closely related to the weakening of meridional overturning circulation and enhanced intrusion of Antarctic Bottom Water into the North Atlantic.

  9. Kaon decay studies at CERN SPS in the last decades

    NASA Astrophysics Data System (ADS)

    Ceccucci, A.; Goudzovski, E.; Kekelidze, V.; Madigozhin, D.; Potrebenikov, I.

    2016-07-01

    This review summarizes the kaon experimental results obtained in the last 15 years on the basis of data collected on the SPS in CERN with a participance of JINR physicists. These results contribute essentially into the Standard Model checks and search for its extension, fundamental symmetry violations and low energy strong interactions theory development. A progress in the experimental technique and prospects for the future results are also discussed.

  10. The last fifty years in obstetrics and gynecology.

    PubMed

    Anspaugh, R D

    1993-12-01

    The last fifty years in Obstetrics and Gynecology have been associated with some of the most outstanding changes in the history of this specialty. We have seen the discovery and use of antibiotics, the Pap smear, shortened hospital stays, the Rh factor, and the birth control pill. It is doubtful we shall ever see as many changes in an equal period of time. PMID:8126591

  11. 2001 BUDGET: NSF and NASA Score Last-Minute Victories.

    PubMed

    Lawler, A; Mervis, J

    2000-10-27

    Congress last week gave both NASA and the National Science Foundation (NSF) significant hikes for 2001: NSF got $4.42 billion, a $522 million boost over this year that nearly matched NSF's 17% request, and NASA received $14.3 billion, nearly twice the White House's request for a 3% boost-but with hundreds of millions of dollars in earmarks added on. PMID:17780498

  12. The last illnesses of Robert and Horace Walpole.

    PubMed Central

    Viseltear, A. J.

    1983-01-01

    Urinary lithiasis and gout were uncommonly prevalent in the eighteenth century. This essay considers the history of both afflictions and especially tells of the last illnesses of Sir Robert Walpole, who died from complications of stone, and his son, Horace, who throughout his life was a sufferer of gout. Images FIG. 1 FIG. 3 FIG. 4 FIG. 5 FIG. 6 FIG. 7 FIG. 8 FIG. 9 PMID:6356637

  13. Tropical boundary layer equilibrium in the last ice age

    NASA Technical Reports Server (NTRS)

    Betts, Alan K.; Ridgway, W.

    1992-01-01

    A radiative-convective boundary layer model is used to assess the effect of changing sea surface temperature, pressure, wind speed, and the energy export from the tropics on the boundary layer equilibrium equivalent potential temperature. It remains difficult to reconcile the observations that during the last glacial maximum (18,000 yr BP) the snowline on the tropical mountains fell 950 m, while the tropical sea surface temperatures fell only 1-2 K.

  14. Belize--a last stronghold for manatees in the Caribbean

    USGS Publications Warehouse

    O'Shea, T.J.; Salisbury, C.A.

    1991-01-01

    Belize is a small country but it offers a safe haven for the largest number of manatees in the Caribbean. The authors' survey in 1989 revealed that there has been no apparent decline since the last study in 1977. However, there is no evidence for population growth either and as the Belize economy develops threats from fisheries, human pressure and declining habitat quality will increase. Recommendations are made to ensure that Belize safeguards its manatee populations.

  15. Bipolar seesaw control on last interglacial sea level.

    PubMed

    Marino, G; Rohling, E J; Rodríguez-Sanz, L; Grant, K M; Heslop, D; Roberts, A P; Stanford, J D; Yu, J

    2015-06-11

    Our current understanding of ocean-atmosphere-cryosphere interactions at ice-age terminations relies largely on assessments of the most recent (last) glacial-interglacial transition, Termination I (T-I). But the extent to which T-I is representative of previous terminations remains unclear. Testing the consistency of termination processes requires comparison of time series of critical climate parameters with detailed absolute and relative age control. However, such age control has been lacking for even the penultimate glacial termination (T-II), which culminated in a sea-level highstand during the last interglacial period that was several metres above present. Here we show that Heinrich Stadial 11 (HS11), a prominent North Atlantic cold episode, occurred between 135 ± 1 and 130 ± 2 thousand years ago and was linked with rapid sea-level rise during T-II. Our conclusions are based on new and existing data for T-II and the last interglacial that we collate onto a single, radiometrically constrained chronology. The HS11 cold episode punctuated T-II and coincided directly with a major deglacial meltwater pulse, which predominantly entered the North Atlantic Ocean and accounted for about 70 per cent of the glacial-interglacial sea-level rise. We conclude that, possibly in response to stronger insolation and CO2 forcing earlier in T-II, the relationship between climate and ice-volume changes differed fundamentally from that of T-I. In T-I, the major sea-level rise clearly post-dates Heinrich Stadial 1. We also find that HS11 coincided with sustained Antarctic warming, probably through a bipolar seesaw temperature response, and propose that this heat gain at high southern latitudes promoted Antarctic ice-sheet melting that fuelled the last interglacial sea-level peak. PMID:26062511

  16. Adolescent ethanol exposure: does it produce long lasting electrophysiological effects?

    PubMed Central

    Ehlers, Cindy L.; Criado, José R.

    2009-01-01

    This review discusses evidence for long lasting neurophysiological changes that may occur following exposure to ethanol during adolescent development in animal models. Adolescence is the time that most individuals first experience ethanol exposure and binge drinking is not uncommon during adolescence. If alcohol exposure is neurotoxic to the developing brain during adolescence, not unlike it is during fetal development, then understanding how ethanol affects the developing adolescent brain becomes a major public health issue. Adolescence is a critical time period when cognitive, emotional and social maturation occurs and it is likely that ethanol exposure may affect these complex processes. In order to study the effects of ethanol on adolescent brain animal models where the dose and time of exposure can be carefully controlled that closely mimic the human condition are needed. The studies reviewed provide evidence that demonstrates that relatively brief exposure to high levels of ethanol, via ethanol vapours, during a period corresponding to parts of adolescence in the rat is sufficient to cause long-lasting changes in functional brain activity. Disturbances in waking EEG and a reduction in the P3 component of the ERP have been demonstrated in adult rats that were exposed to ethanol vapour during adolescence. Adolescent ethanol exposure was also found to produce long lasting reductions in the mean duration of slow-wave sleep (SWS) episodes and the total amount of time spent in SWS, a finding consistent with a premature aging of sleep. Further studies are necessary to confirm these findings, in a range of strains, and to link those findings to the neuroanatomical and neurochemical mechanisms potentially underlying the lasting effects of adolescent ethanol exposure. PMID:20113872

  17. Last Glacial Maximum and deglaciation of the Iberian Central System.

    NASA Astrophysics Data System (ADS)

    Palacios, D.; Andrés, N.; Vieira, G.; Marcos, J.; Vázquez-Selem, L.

    2012-04-01

    The Central System runs E-W across the centre of the Iberian Peninsula and is composed mainly of crystalline rocks. A glacial morphology is well preserved on many of its most important summit areas especially towards the Atlantic. Research has recently been carried out in three of the sierras of this mountain system, with the aim of establishing the absolute chronology of the maximum glacial advance and of the deglaciation in the whole system. The method used is cosmogenic 36Cl surface exposure dating of moraine boulders and glacially polished outcrops. The selected areas are the Sierra de Guadarrama (Palacios et al. 2012) close to Peñalara Peak (40°51'N, 3°57'W; 2428 m), the Sierra de Gredos (Palacios et al. 2011) close to Almanzor Peak (40°14'N, 5°17'W; 2592 m), and the Sierra de la Estrela (Vieira and Palacios, 2010) close to Alto de la Torre summit (40°20'N, 7°34'W; 1993 m). These areas are representative of the whole Central System from west to east. The results are highly homogeneous. Moraines dating from earlier than the last glaciation were not found in any of the sierras. On the contrary, in all cases the oldest moraines from the last glaciation rest on intensely weathered crystalline surfaces. The oldest moraines date from between 31 and 26 ka. In most cases, the deposition of these moraine ridges was followed by minor advances and retreats which left a sequence of ridges very close together, lasting until 18-16 ka. A fast retreat occurred after 16-15 ka, when glaciers completely abandoned the valleys, disappearing in most cases by 13-14 ka. The ice lasted until 11-10 ka, but only in small cirques found on sheltered rock-walls below the highest peaks.

  18. The rainfall regime in Lisbon in the last 150 years

    NASA Astrophysics Data System (ADS)

    Kutiel, H.; Trigo, R. M.

    2014-11-01

    The first decades of the rainfall series of Lisbon have been digitized recently allowing a long-term assessment of the rainfall regime for 150 years of uninterrupted, i.e., the first assessment for the longest continuous precipitation time series in western Iberia. This data has been monitored continuously at the D. Luís observatory having started to be published in 1864 in the Observatory's log books (Annals). We use an approach based on different characteristics of rain spells that has been proved to be satisfactory for the analysis of the different parameters related to the rainfall regime in that part of the world. Thus, a rain spell is defined as a series of consecutive days with a measured daily rainfall equal or higher than 1.0 mm. Each rain spell is preceded and followed by at least one dry day. For each rain spell, its duration, its yield (RSY), and its average intensity (RSI) was calculated. Additionally, the total number of rain spells in each year was also considered. Dryness was analyzed using the dry days since last rain approach. Besides the evaluation over the entire 150-year period available, we have also looked into three equally spaced sub-periods. Lisbon reveals large inter-annual and intra-annual variability and both have increased considerably in the last decades. The large intra-annual variability is demonstrated by both; a very large range of annual rainfall percentage accumulated at any given date and by a very large range of dates on which a certain rainfall percentage was accumulated. Again, both metrics increased in the last decades. Parallel to the increase in the uncertainty, a very significant net increase is noticed in the annual totals since the 1960s compared to the first half of the previous century. The increase is mainly due to more intense events which are reflected by higher RSY and RSI values in the last 50 years.

  19. The last interglacial-glacial period on spitsbergen, Svalbard

    NASA Astrophysics Data System (ADS)

    Mangerud, Jan; Svendsen, John Inge

    The glaciation history of Svalbard (78°N) and the NW Barents Sea is reconstructed for the last 130 ka, based on studies of sediments exposed in coastal cliffs at the head of Isfjorden. Four different till beds separated by marine sediments are recognized. The lowest marine formation, containing Mytilus edulis, reflects warmer conditions than at present, and is correlated with the last interglacial, the Eemian of Europe and Oxygen Isotope Substage 5e in the deep sea. The post-Eemian tills are inferred to represent major glaciations around 110 ka BP, 75-50 ka BP, and 25-10 ka BP. During the intervening intervals the glaciers on Svalbard were not significantly larger than at present and the NW Barents Sea was probably ice-free. The ice-free periods, named Phantomodden and Kapp Ekholm interstadials, lasted from about 110 to 75 and from 50 to 25 ka BP respectively. The marine fauna from both these interstadials indicate seasonally ice free conditions. The ages of the recorded glaciations coincide with, or are slightly younger than, periods with insolation minima, which at this latitude is determined by a low tilt of the Earth's axis. Thus we postulate that the Quaternary glaciations of Svalbard were driven by orbital variations with the 41 ka tilt period, in contrast to the lower-latitude glaciations of Scandinavia that were partly driven by the precession cycle with a periodicity of around 23 ka.

  20. Rapid and long-lasting learning of feature binding.

    PubMed

    Yashar, Amit; Carrasco, Marisa

    2016-09-01

    How are features integrated (bound) into objects and how can this process be facilitated? Here we investigated the role of rapid perceptual learning in feature binding and its long-lasting effects. By isolating thecontributions of individual features from their conjunctionsbetween training and test displays, we demonstrate for the first time that training can rapidly and substantially improve feature binding. Observers trained on a conjunction search task consisting of a rapid display with one target-conjunction, then tested with a new target-conjunction. Features were the same between training and test displays. Learning transferred to the new target when its conjunction was presented as a distractor, but not when only its component features were presented in different conjunction distractors during training. Training improvement lasted for up to 16months, but, in all conditions, it was specific to the trained target. Our findings suggest that with short training observers' ability to bind two specific features into an object is improved, and that this learning effect can last for over a year. Moreover, our findings show that while the short-term learning effect reflects activation of presented items and their binding, long-term consolidation is task specific. PMID:27289484

  1. Last Millennium Climate and Its Variability in CCSM4

    NASA Astrophysics Data System (ADS)

    Otto-Bliesner, B. L.; Landrum, L.; Conley, A.; Lawrence, P.; Rosenbloom, N. A.; Teng, H.

    2011-12-01

    The Last Millennium simulation of the Community Climate System Model version 4 (CCSM4) reproduces many large-scaled climate patterns suggested by historical and proxy-data records including cooling from the Medieval Climate Anomaly to the Little Ice Age, a "hockey-stick" pattern of surface temperature changes from 850-2005, and a broad cooling with a delayed La Niña-type of pattern in the tropical Pacific response to large volcanic events. Atmospheric modes, one oceanic mode (the Pacific Decadal Oscillation), and one ocean-atmosphere coupled mode (the El Niño-Southern Oscillation) of variability show little or no change in their variances, teleconnection patterns and spectra between the Last Millennium simulation and the 1850 non-transient control run. Two oceanic modes, the Atlantic Multidecadal Oscillation and the Atlantic Meridional Overturning Circulation have higher variances and increased power at low frequencies in the Last Millennium simulation compared with the control run, suggesting long-term oceanic response to natural solar and volcanic forcings.

  2. Shared binding sites in Lepidoptera for Bacillus thuringiensis Cry1Ja and Cry1A toxins.

    PubMed

    Herrero, S; González-Cabrera, J; Tabashnik, B E; Ferré, J

    2001-12-01

    Bacillus thuringiensis toxins act by binding to specific target sites in the insect midgut epithelial membrane. The best-known mechanism of resistance to B. thuringiensis toxins is reduced binding to target sites. Because alteration of a binding site shared by several toxins may cause resistance to all of them, knowledge of which toxins share binding sites is useful for predicting cross-resistance. Conversely, cross-resistance among toxins suggests that the toxins share a binding site. At least two strains of diamondback moth (Plutella xylostella) with resistance to Cry1A toxins and reduced binding of Cry1A toxins have strong cross-resistance to Cry1Ja. Thus, we hypothesized that Cry1Ja shares binding sites with Cry1A toxins. We tested this hypothesis in six moth and butterfly species, each from a different family: Cacyreus marshalli (Lycaenidae), Lobesia botrana (Tortricidae), Manduca sexta (Sphingidae), Pectinophora gossypiella (Gelechiidae), P. xylostella (Plutellidae), and Spodoptera exigua (Noctuidae). Although the extent of competition varied among species, experiments with biotinylated Cry1Ja and radiolabeled Cry1Ac showed that Cry1Ja and Cry1Ac competed for binding sites in all six species. A recent report also indicates shared binding sites for Cry1Ja and Cry1A toxins in Heliothis virescens (Noctuidae). Thus, shared binding sites for Cry1Ja and Cry1A occur in all lepidopteran species tested so far. PMID:11722929

  3. Shared Binding Sites in Lepidoptera for Bacillus thuringiensis Cry1Ja and Cry1A Toxins

    PubMed Central

    Herrero, Salvador; González-Cabrera, Joel; Tabashnik, Bruce E.; Ferré, Juan

    2001-01-01

    Bacillus thuringiensis toxins act by binding to specific target sites in the insect midgut epithelial membrane. The best-known mechanism of resistance to B. thuringiensis toxins is reduced binding to target sites. Because alteration of a binding site shared by several toxins may cause resistance to all of them, knowledge of which toxins share binding sites is useful for predicting cross-resistance. Conversely, cross-resistance among toxins suggests that the toxins share a binding site. At least two strains of diamondback moth (Plutella xylostella) with resistance to Cry1A toxins and reduced binding of Cry1A toxins have strong cross-resistance to Cry1Ja. Thus, we hypothesized that Cry1Ja shares binding sites with Cry1A toxins. We tested this hypothesis in six moth and butterfly species, each from a different family: Cacyreus marshalli (Lycaenidae), Lobesia botrana (Tortricidae), Manduca sexta (Sphingidae), Pectinophora gossypiella (Gelechiidae), P. xylostella (Plutellidae), and Spodoptera exigua (Noctuidae). Although the extent of competition varied among species, experiments with biotinylated Cry1Ja and radiolabeled Cry1Ac showed that Cry1Ja and Cry1Ac competed for binding sites in all six species. A recent report also indicates shared binding sites for Cry1Ja and Cry1A toxins in Heliothis virescens (Noctuidae). Thus, shared binding sites for Cry1Ja and Cry1A occur in all lepidopteran species tested so far. PMID:11722929

  4. Update from the Japanese Center for the Validation of Alternative Methods (JaCVAM).

    PubMed

    Kojima, Hajime

    2013-12-01

    The Japanese Center for the Validation of Alternative Methods (JaCVAM) was established in 2005 to promote the use of alternatives to animal testing in regulatory studies, thereby replacing, reducing, or refining the use of animals, according to the Three Rs principles. JaCVAM assesses the utility, limitations and suitability for use in regulatory studies, of test methods needed to determine the safety of chemicals and other materials. JaCVAM also organises and performs validation studies of new test methods, when necessary. In addition, JaCVAM co-operates and collaborates with similar organisations in related fields, both in Japan and internationally, which also enables JaCVAM to provide input during the establishment of guidelines for new alternative experimental methods. These activities help facilitate application and approval processes for the manufacture and sale of pharmaceuticals, chemicals, pesticides, and other products, as well as for revisions to standards for cosmetic products. In this manner, JaCVAM plays a leadership role in the introduction of new alternative experimental methods for regulatory acceptance in Japan. PMID:24512226

  5. Influence factors and gene expression patterns during MeJa-induced gummosis in peach.

    PubMed

    Li, Minji; Liu, Meiyan; Peng, Futian; Fang, Long

    2015-06-15

    Jasmonates (JAs) play important roles in gummosis in peach. Mechanical damage, methyl jasmonate (MeJa), and ethylene can induce gummosis on peach shoots in the field. In this study, we used MeJa (2%, w/w) to induce gummosis on current-year shoots in peach on high temperature (35°C). Based on the experimental model, we studied the influence of factors on the development of peach gummosis. Our experimental results showed that high temperature could promote gummosis development induced by MeJa. Exogenous CaCl2 treatment reduced the degree of gummosis by increasing the calcium content in shoots, which is conducive to the synthesis and maintenance of the cell wall. Using digital gene expression (DGE), 3831 differentially expressed genes were identified in the MeJa treatment versus the control. By analyzing changes in gene expression associated with cell wall degradation, genes encoding pectin methylesterase (PME) and endo-polygalacturonase (PG) were found to be significantly induced, suggesting that they are key enzymes in cell wall degradation that occurs during MeJa-induced gummosis. Genes for glycosyltransferase (GT) and cellulose synthase (CS) were also significantly upregulated by MeJa. This result suggests that MeJa treatment not only promotes the degradation of polysaccharides to destroy the cell wall, but also promotes the synthesis of new polysaccharides. We also analyzed changes in gene expression associated with sugar metabolism, senescence, and defense. MeJa treatment affected the expression of genes related to sugar metabolism and promoted plant senescence. Among the defense genes, the expression pattern of phenylalanine ammonium lyase (PAL) suggested that PAL may play an important role in protecting against the effects of MeJa treatment. Our experimental results showed that MeJa treatment can promote the biosynthesis and signal transduction of ethylene in peach shoots; they can induce gummosis on peach shoots respectively, and there are overlaps between

  6. GOCE - Validation of last days' orbits with kinematic PPP

    NASA Astrophysics Data System (ADS)

    Bock, Heike; Jäggi, Adrian; Meyer, Ulrich

    2014-05-01

    After more than four years of successful operations the first ESA Earth Explorer Mission GOCE has officially ended on 21 October 2013, because the fuel for the ion engine was depleted on this day. Three weeks later on 11 November 2013 the satellite re-entered into the Earth's atmosphere over the South Atlantic. The two onboard GPS receivers were switched on until a few hours before the re-entry and the orbit could therefore still be determined during the last days of the satellite. This is the first time that GPS measurements are available for such a low flying and descending satellite. The AIUB has been responsible for the precise science orbit determination of the satellite, which included both a reduced-dynamic and a kinematic orbit solution. The orbit determination procedures are based on GPS zero-difference processing and follow the precise point positioning principle that the GPS orbits and clocks are used from a global network solution. Since the reduced-dynamic orbit is less sensitive to data problems and possible gaps it was used among others to validate the quality of the kinematic orbit during the nominal mission period until 21 October 2013. During the last three weeks before re-entry it was done the other way round and the kinematic orbit has been used to validate the reduced-dynamic orbit. The drag increased significantly and the empirical parametrization of the reduced-dynamic orbit determination had to be adapted accordingly. The GPS data quality did not suffer and it was still possible to generate kinematic orbits of good quality. Orbit results from this last mission phase will be presented with the focus on the validation of the reduced-dynamic orbit.

  7. The INTIMATE event stratigraphy of the last glacial period

    NASA Astrophysics Data System (ADS)

    Olander Rasmussen, Sune; Svensson, Anders

    2015-04-01

    The North Atlantic INTIMATE (INtegration of Ice-core, MArine and TErrestrial records) group has previously recommended an Event Stratigraphy approach for the synchronisation of records of the Last Termination using the Greenland ice core records as the regional stratotypes. A key element of these protocols has been the formal definition of numbered Greenland Stadials (GS) and Greenland Interstadials (GI) within the past glacial period as the Greenland expressions of the characteristic Dansgaard-Oeschger events that represent cold and warm phases of the North Atlantic region, respectively. Using a recent synchronization of the NGRIP, GRIP, and GISP2 ice cores that allows the parallel analysis of all three records on a common time scale, we here present an extension of the GS/GI stratigraphic template to the entire glacial period. In addition to the well-known sequence of Dansgaard-Oeschger events that were first defined and numbered in the ice core records more than two decades ago, a number of short-lived climatic oscillations have been identified in the three synchronized records. Some of these events have been observed in other studies, but we here propose a consistent scheme for discriminating and naming all the significant climatic events of the last glacial period that are represented in the Greenland ice cores. In addition to presenting the updated event stratigraphy, we make a series of recommendations on how to refer to these periods in a way that promotes unambiguous comparison and correlation between different proxy records, providing a more secure basis for investigating the dynamics and fundamental causes of these climatic perturbations. The work presented is a part of a newly published paper in an INTIMATE special issue of Quaternary Science Reviews: Rasmussen et al., 'A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event

  8. Windiness spells in SW Europe since the last glacial maximum

    NASA Astrophysics Data System (ADS)

    Costas, Susana; Naughton, Filipa; Goble, Ronald; Renssen, Hans

    2016-02-01

    Dunefields have a great potential to unravel past regimes of atmospheric circulation as they record direct traces of this component of the climate system. Along the Portuguese coast, transgressive dunefields represent relict features originated by intense and frequent westerly winds that largely contrast with present conditions, clearly dominated by weaker northwesterly winds. Optical dating and subsurface stratigraphy document three age clusters indicating main episodes of dune mobilization during: the last termination (20-11.6 ka), Middle Holocene (5.6 ka), and Late Holocene (1.2-0.98 and 0.4-0.15 ka). We find reconstructed windfields to be analogous during all episodes and dominated by strong westerlies. Yet, larger grain size diameters and dune volumes documented for the last termination support amplified patterns compatible with a southward shift and intensification of the North Atlantic westerlies during winters. Conversely, dunes deposited after the Middle Holocene are compatible with more variable windfields and weakened patterns controlled by interannual shifts towards low values of the North Atlantic Oscillation (NAO). This work demonstrates that present windfield regimes in southern Europe are not compatible with past aeolian activity. Indeed, present day analogs indicate that wind intensities compatible with past aeolian activity are rare at present (sediment transport potentials below estimates in the aeolian record), but can occur if the jet stream is diverted to the south (i.e. 30°N with negative NAO index) or if very deep cyclones anchor around 50°N, extending their influence to the western Portuguese coast (relatively low NAO index). However, these conditions represent temporary patterns lasting around one day, while we suggest that the identified episodes of aeolian activity may represent semi-permanent conditions.

  9. Interhemispheric ice-sheet synchronicity during the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Weber, M. E.; Clark, P. U.; Ricken, W.; Mitrovica, J. X.; Hostetler, S. W.; Kuhn, G.

    2012-04-01

    The timing of the last maximum extent of the Antarctic ice sheets relative to those in the Northern Hemisphere remains poorly understood because only a few findings with robust chronologies exist for Antarctic ice sheets. We developed a chronology for the Weddell Sea sector of the East Antarctic ice sheet that, combined with ages from other Antarctic ice-sheet sectors, indicates the advance to their maximum extent at 29 -28 ka, and retreat from their maximum extent at 19 ka was nearly synchronous with Northern Hemisphere ice sheets (Weber, M.E., Clark, P. U., Ricken, W., Mitrovica, J. X., Hostetler, S. W., and Kuhn, G. (2011): Interhemispheric ice-sheet synchronicity during the Last Glacial Maximum. - Science, 334, 1265-1269, doi: 10.1126:science.1209299). As for the deglaciation, modeling studies suggest a late ice-sheet retreat starting around 14 ka BP and ending around 7 ka BP with a large impact of an unstable West Antarctic Ice Sheet (WAIS) and a small impact of a stable East Antarctic Ice Sheet (EAIS). However, the Weddell Sea sites studied here, as well as sites from the Scotia Sea, provide evidence that specifically the EAIS responded much earlier, possibly provided a significant contribution to the last sea-level rise, and was much more dynamic than previously thought. Using the results of an atmospheric general circulation we conclude that surface climate forcing of Antarctic ice mass balance would likely cause an opposite response, whereby a warming climate would increase accumulation but not surface melting. Furthermore, our new data support teleconnections involving a sea-level fingerprint forced from Northern Hemisphere ice sheets as indicated by gravitational modeling. Also, changes in North Atlantic Deepwater formation and attendant heat flux to Antarctic grounding lines may have contributed to synchronizing the hemispheric ice sheets.

  10. Geomagnetism and climate I: the last 400 years

    NASA Astrophysics Data System (ADS)

    Nevanlinna, H.; Shumilov, O.; Mörner, N.-A.; Dergachev, V.

    2003-04-01

    During the last 400 years there seems to exist a close linkage between sunspot activity and paleoclimate. The combined Schwabe Gleisberg cycles provide a good approximation of past climate. Changes in the phase of the sunspot cycles exhibit a very close correlation with observed changes in climate for the last 150 years. The heliomagnetic aa-index provides a close correlation with climate over the last 150 years. The close correlation between sunspot activity and atmospheric changes in radiocarbon indicates that changes in heliomagnetic interaction with the Earth’s magnetosphere play a central role in this solar-terrestrial interaction; via its modulation of the cosmic ray flux or its modulation of Earth’s rate of rotation. Variations in cosmic ray flux have the capacity of affecting Earth’s climate via its modulation of airglow and cloudiness (especially at the level around 15 km). There is a good correlation between Solar Wind intensity and Earth’s rate of rotation (LOD), implying that variations in Solar Wind intensity (sunspot activity) act in retarding and speeding up in the spin rate of Planet Earth. During the Spörer, Maunder and Dalton Sunspot Minima, the Earth’s rate of rotation was significantly speeded-up, affecting the ocean surface circulation and the atmospheric circulation as to create significant changes in local climate; “Little Ice Ages” in western and northern Europe and “Little Interglacial” in southwest Europe and northwest Africa. In conclusion, Earth’s climate seems closely driven by changes in sunspot activity. This correlation may operate via the cosmic ray effects on airglow and/or cloudiness, or via the heliomagnetic (Solar Wind) effects on Earth’s rate of rotation, or a combination of these processes. Changes in the Earth’s own internal geomagnetic field seem to have played little or no role during this time period. Nor are there any reasons to advocate major changes in Solar irradiance.

  11. Interhemispheric Anti-phased Climate Changes During the Last Deglaciation

    NASA Astrophysics Data System (ADS)

    Wang, X.; Auler, A. S.; Edwards, R. L.; Cheng, H.; Ito, E.; Solheid, M.

    2005-12-01

    We have obtained a high-resolution oxygen isotopic record of cave calcite from Gruta Do Padre (PAD), central Brazil. The chronology was determined by 20 U-Th ages from 2 stalagmites. Tests for equilibrium conditions show that oxygen isotopic variations are primarily caused by climate change. We interpreted the PAD record, spanning the last 16 thousand years, in terms of meteoric precipitation changes at this low-latitude location. The oxygen isotopic profile shows clear abrupt millennial-scale variations with amplitudes as large as 3 per mil. Using independent age scales, we compare the record to contemporaneous records from caves in eastern China and high latitude ice cores. During the last deglaciation, PAD calcite δ18O anti-correlates remarkably with δ18O in the Hulu Cave (Wang et al., 2001, Science), indicating that precipitation histories at the two sites are anti-phased, similar to our previous observations from southern Brazil speleothems. As Greenland temperature has been shown to correlate with Hulu precipitation, PAD precipitation anti-correlates with Greenland temperature. The timing of the main transition at PAD is synchronous within error with the Hulu and Greenland records. For instance, the rapid PAD transitions into a dry "Bolling-Allerod", and the beginning and the end of a wet "Younger Dryas", occur at about 14620±60 yr B.P., 12750±60 yr B.P., and 11600±100 yr B.P., respectively. Such anti-correlations support the bipolar see-saw mechanism through the last glacial-interglacial transition. However, the millennial-scale climate variability probably involves both ocean thermohaline and atmospheric circulation changes.

  12. Cannabinoids and Reproduction: A Lasting and Intriguing History

    PubMed Central

    Cacciola, Giovanna; Chianese, Rosanna; Chioccarelli, Teresa; Ciaramella, Vincenza; Fasano, Silvia; Pierantoni, Riccardo; Meccariello, Rosaria; Cobellis, Gilda

    2010-01-01

    Starting from an historical overview of lasting Cannabis use over the centuries, we will focus on a description of the cannabinergic system, with a comprehensive analysis of chemical and pharmacological properties of endogenous and synthetic cannabimimetic analogues. The metabolic pathways and the signal transduction mechanisms, activated by cannabinoid receptors stimulation, will also be discussed. In particular, we will point out the action of cannabinoids and endocannabinoids on the different neuronal networks involved in reproductive axis, and locally, on male and female reproductive tracts, by emphasizing the pivotal role played by this system in the control of fertility.

  13. Last Advances in Silicon-Based Optical Biosensors

    PubMed Central

    Fernández Gavela, Adrián; Grajales García, Daniel; Ramirez, Jhonattan C.; Lechuga, Laura M.

    2016-01-01

    We review the most important achievements published in the last five years in the field of silicon-based optical biosensors. We focus specially on label-free optical biosensors and their implementation into lab-on-a-chip platforms, with an emphasis on developments demonstrating the capability of the devices for real bioanalytical applications. We report on novel transducers and materials, improvements of existing transducers, new and improved biofunctionalization procedures as well as the prospects for near future commercialization of these technologies. PMID:26927105

  14. Neosporosis in animals--the last five years.

    PubMed

    Dubey, J P; Schares, G

    2011-08-01

    Neospora caninum is a protozoan parasite of animals. Until 1988, it was misdiagnosed as Toxoplasma gondii. Since its first recognition in 1984 in dogs and the description of a new genus and species Neospora caninum in 1988, neosporosis has emerged as a serious disease of cattle and dogs worldwide. Abortions and neonatal mortality are a major problem in livestock operations and neosporosis is a major cause of abortion in cattle. This review is focused on current status of neosporosis in animals based on papers published in the last five years. Worldwide seroprevalences are tabulated. Strategies for control and prevention are discussed. PMID:21704458

  15. CAM research in Britain: the last 10 years.

    PubMed

    Ernst, E; Schmidt, K; Wider, B

    2005-02-01

    Research into complementary and alternative medicine (CAM) is not as new as it might appear from a U.K. perspective. Most continental European countries have a long tradition in CAM research. Many studies of homoeopathy, for instance, were published decades ago in languages other than English [The trials of homeopathy. Origins, structure and development. Stiftung: Essen, Karl und Veronica Carstens, 2004]. However, it is probably true to say that, in the English speaking world and particularly in the U.K., CAM has become a respectable area of scientific investigation only during the last decade. In this article, we review the 10 years of CAM research in Britain. PMID:15984219

  16. Northern high latitude climate variability of the last millennium

    NASA Astrophysics Data System (ADS)

    Andres, Heather J.

    This work explores the causes of northern high-latitude climate variations over the last millennium, and industrial and future periods. Attribution studies are performed on a suite of global climate simulations, and four historical reconstructions of Greenland surface temperatures and precipitation (two of which are new to this work). The simulations followed the protocols of the Palaeoclimate Modelling Intercomparison Project 3 and Coupled Model Intercomparison Project 5. At least half of the multi-decadal variability in simulated Greenland climate variations over the last millennium is reproduced by a linear, empirically-generated model including terms for volcanic emissions, solar insolation changes (including total solar irradiance and orbital components) and an index associated with latitudinal shifts in the North Atlantic jet. Empirical model parameters are obtained by regressing simulated Greenland temperatures and precipitation against time series for each of the response variables. Greenhouse gas radiative forcing changes are unimportant to simulated Greenland conditions over the last millennium, although they dominate after the mid-20th century. Most of the historical Greenland climate reconstructions are restricted to the industrial period, due to a lack of spatially-comprehensive climate records. They exhibit substantial differences in the timing, phasing and amplitudes of past climate variations, due to regional sensitivities in the source data and the reconstruction methodologies. Reconstructions indicate that Greenland temperatures did not begin to follow hemispheric greenhouse gas warming patterns until the mid-1990s. This discrepancy indicates either that the warming hiatus was associated with internal climate variability, or that the simulations are missing processes important to Greenland climate. For example, indirect effects of anthropogenic aerosols are not captured in the climate model employed here. All of the external climate forcings

  17. The λ-symmetry reduction method and Jacobi last multipliers

    NASA Astrophysics Data System (ADS)

    Muriel, C.; Romero, J. L.

    2014-04-01

    For nth order ordinary differential equations, it is studied the role of a Jacobi last multiplier (JLM) in the reduction processes that arise from the existence of either a k parametric symmetry group or a λ-symmetry. For the reduction derived from a λ-symmetry, JLMs are inherited as integrating factors of the auxiliary equations. Several ways that have appeared recently to solve the determining equations of the λ-symmetries are also analysed. Two examples illustrate the combined use of λ-symmetries and JLMs to obtain the complete solution of the equations.

  18. Alfred Lee Loomis - last great amateur of science

    SciTech Connect

    Alvarex, L.W.

    1983-01-01

    Alfred Loomis may well be remembered as the last of the great amateurs of science. He had distinguished careers as a lawyer, as an Army officer and as an investment banker before he turned his full energies to the pursuit of scientific knowledge, first in the field of physics and later as a biologist. By any measure that can be employed, he was one of the most influential physical scientists of this century: he was elected to the National Academy when he was 53 years old; he received many honorary degrees from prestigious universities; and he played a crucial role as director of all NDRC-OSRD radar research in World War II.

  19. Last Advances in Silicon-Based Optical Biosensors.

    PubMed

    Fernández Gavela, Adrián; Grajales García, Daniel; Ramirez, Jhonattan C; Lechuga, Laura M

    2016-01-01

    We review the most important achievements published in the last five years in the field of silicon-based optical biosensors. We focus specially on label-free optical biosensors and their implementation into lab-on-a-chip platforms, with an emphasis on developments demonstrating the capability of the devices for real bioanalytical applications. We report on novel transducers and materials, improvements of existing transducers, new and improved biofunctionalization procedures as well as the prospects for near future commercialization of these technologies. PMID:26927105

  20. Bioturbation: a fresh look at Darwin's last idea.

    PubMed

    Meysman, Filip J R; Middelburg, Jack J; Heip, Carlo H R

    2006-12-01

    Bioturbation refers to the biological reworking of soils and sediments, and its importance for soil processes and geomorphology was first realised by Charles Darwin, who devoted his last scientific book to the subject. Here, we review some new insights into the evolutionary and ecological role of bioturbation that would have probably amazed Darwin. In modern ecological theory, bioturbation is now recognised as an archetypal example of 'ecosystem engineering', modifying geochemical gradients, redistributing food resources, viruses, bacteria, resting stages and eggs. From an evolutionary perspective, recent investigations provide evidence that bioturbation had a key role in the evolution of metazoan life at the end of the Precambrian Era. PMID:16901581

  1. Atmospheric carbon dioxide levels for the last 500 million years.

    PubMed

    Rothman, Daniel H

    2002-04-01

    The last 500 million years of the strontium-isotope record are shown to correlate significantly with the concurrent record of isotopic fractionation between inorganic and organic carbon after the effects of recycled sediment are removed from the strontium signal. The correlation is shown to result from the common dependence of both signals on weathering and magmatic processes. Because the long-term evolution of carbon dioxide levels depends similarly on weathering and magmatism, the relative fluctuations of CO2 levels are inferred from the shared fluctuations of the isotopic records. The resulting CO2 signal exhibits no systematic correspondence with the geologic record of climatic variations at tectonic time scales. PMID:11904360

  2. Changes in Space Food over the Last 45 Years

    NASA Technical Reports Server (NTRS)

    Smith, Scott M.; Lane, Helen W.; Kloeris, Vickie; Perchonok, Michele; Zwart, Sara

    2006-01-01

    The space food system has improved over the last 45 years. With the advances for a Moon base, there is a potential that foods in space will be more like home cooked foods. However, until that happens, there will continue to be dehydrated and thermostablized foods providing the bulk of the astronauts food. In order for the astronauts to have adequate macronutrients, a food system must be developed including raising plants and food preparation, both a major challenge given the limited water, volume, and power. The lunar kitchens will be very different, but good food is essential to maintain good health.

  3. A Last-Resort Semantic Cache for Web Queries

    NASA Astrophysics Data System (ADS)

    Ferrarotti, Flavio; Marin, Mauricio; Mendoza, Marcelo

    We propose a method to evaluate queries using a last-resort semantic cache in a distributed Web search engine. The cache stores a group of frequent queries and for each of these queries it keeps minimal data, that is, the list of machines that produced their answers. The method for evaluating the queries uses the inverse frequency of the terms in the queries stored in the cache (Idf) to determine when the results recovered from the cache are a good approximation to the exact answer set. Experiments show that the method is effective and efficient.

  4. Last Glacial vegetation and climate change in the southern Levant

    NASA Astrophysics Data System (ADS)

    Miebach, Andrea; Chen, Chunzhu; Litt, Thomas

    2015-04-01

    Reconstructing past climatic and environmental conditions is a key task for understanding the history of modern mankind. The interaction between environmental change and migration processes of the modern Homo sapiens from its source area in Africa into Europe is still poorly understood. The principal corridor of the first human dispersal into Europe and also later migration dynamics crossed the Middle East. Therefore, the southern Levant is a key area to investigate the paleoenvironment during times of human migration. In this sense, the Last Glacial (MIS 4-2) is particularly interesting to investigate for two reasons. Firstly, secondary expansions of the modern Homo sapiens are expected to occur during this period. Secondly, there are ongoing discussions on the environmental conditions causing the prominent lake level high stand of Lake Lisan, the precursor of the Dead Sea. This high stand even culminated in the merging of Lake Lisan and Lake Kinneret (Sea of Galilee). To provide an independent proxy for paleoenvironmental reconstructions in the southern Levant during the Last Glacial, we investigated pollen assemblages of the Dead Sea/Lake Lisan and Lake Kinneret. Located at the Dead Sea Transform, the freshwater Lake Kinneret is nowadays connected via the Jordan with the hypersaline Dead Sea, which occupies Earth's lowest elevation on land. The southern Levant is a transition area of three different vegetation types. Therefore, also small changes in the climate conditions effect the vegetation and can be registered in the pollen assemblage. In contrast to the Holocene, our preliminary results suggest another vegetation pattern during the Last Glacial. The vegetation belt of the fragile Mediterranean biome did no longer exist in the vicinity of Lake Kinneret. Moreover, the vegetation was rather similar in the whole study area. A steppe vegetation with dwarf shrubs, herbs, and grasses predominated. Thermophilous elements like oaks occurred in limited amounts. The

  5. Using Modified J-A model in MMM detection at elastic stress stage

    NASA Astrophysics Data System (ADS)

    Xu, MingXiu; Xu, MinQiang; Li, JianWei; Xing, HaiYan

    2012-06-01

    In order to propel the development of metal magnetic memory (MMM) technique in fatigue damage detection, a modified Jiles-Atherton (J-A) model is constructed to describe MMM mechanism in elastic stress stage. The MMM phenomenon is discussed from the view of energy minimum theory and equivalent magnetic field theory, the modified J-A model is constructed based on the energy balance in the process of magnetisation and the idea of J-A model, and the new model is used to simulate magnetomechanical effect by Matlab and compare with experimental results. It is shown that the forming process of MMM field is cyclic magnetisation in the range of equivalent magnetic field and the MMM field moves irreversibly towards a local equilibrium state ? . ? is the intermediate state with some pinning before M reaches the anhysteretic magnetisation state ? . The ? curve is a loop around the ? curve, and it changes with ? , H and the type of stress cycle. The modified J-A model that is suited for MMM detection is constructed by replacing ? in J-A model with ? and changing some parameters, and it can describe magnetisation features in tension, release processes better and explain the changes in the sign of ? that have been observed in experiments more reasonably. The modified J-A model can simulate the process of MMM field to become steady and the MMM field variation at fatigue process theoretically by changing model parameters, which is confirmed by experimental results. The results of theoretical research, simulation analysis and experiment verification all indicate that the modified J-A model can be used to describe MMM mechanism in elastic stress stage and analyse MMM field changes at fatigue process.

  6. Deoxygenation of the Baltic Sea during the last century

    PubMed Central

    Carstensen, Jacob; Andersen, Jesper H.; Gustafsson, Bo G.; Conley, Daniel J.

    2014-01-01

    Deoxygenation is a global problem in coastal and open regions of the ocean, and has led to expanding areas of oxygen minimum zones and coastal hypoxia. The recent expansion of hypoxia in coastal ecosystems has been primarily attributed to global warming and enhanced nutrient input from land and atmosphere. The largest anthropogenically induced hypoxic area in the world is the Baltic Sea, where the relative importance of physical forcing versus eutrophication is still debated. We have analyzed water column oxygen and salinity profiles to reconstruct oxygen and stratification conditions over the last 115 y and compare the influence of both climate and anthropogenic forcing on hypoxia. We report a 10-fold increase of hypoxia in the Baltic Sea and show that this is primarily linked to increased inputs of nutrients from land, although increased respiration from higher temperatures during the last two decades has contributed to worsening oxygen conditions. Although shifts in climate and physical circulation are important factors modulating the extent of hypoxia, further nutrient reductions in the Baltic Sea will be necessary to reduce the ecosystems impacts of deoxygenation. PMID:24706804

  7. A White Nile megalake during the last interglacial period

    NASA Astrophysics Data System (ADS)

    Barrows, Timothy T.; Williams, Martin A. J.; Mills, Stephanie C.; Duller, Geoff A. T.; Fifield, L. Keith; Haberlah, David; Tims, Stephen G.; Williams, Frances M.

    2014-05-01

    The eastern Sahara Desert of Africa is one of the most climatically sensitive areas on Earth, varying from lake-studded savannah woodland to hyperarid desert over the course of a glacial-interglacial cycle. In currently semiarid Sudan there is widespread evidence that a very large freshwater lake once filled the White Nile River valley (Barrows et al., 2014). Here we present the first quantitative estimate for the dimensions of the lake and a direct age for the emplacement of its shoreline. Using a profile dating approach with the cosmogenic nuclide 10Be, we estimate an exposure age of 109 ± 8 ka for this megalake, indicating that it probably formed during the last interglacial period. This age is supported by optically stimulated luminescence dating of Blue Nile paleochannels associated with the lake. Using a high-resolution digital elevation model, we estimate that the lake was more than 45,000 km2 in area, making it comparable to the largest freshwater lakes on Earth today. We attribute the lake's existence to seasonal flood pulses as a result of local damming of the White Nile by a more southern position of the Blue Nile and greatly increased precipitation associated with an enhanced monsoon. References Barrows, T.T., Williams, M.A.J., Mills, S.C., Duller, G.A.T., Fifield, L.K., Haberlah, D., Tims, S.G., Williams, F.M., 2014. A White Nile megalake during the last interglacial period. Geology. 10.1130/g35238.1

  8. Trends in sensitivity analysis practice in the last decade.

    PubMed

    Ferretti, Federico; Saltelli, Andrea; Tarantola, Stefano

    2016-10-15

    The majority of published sensitivity analyses (SAs) are either local or one factor-at-a-time (OAT) analyses, relying on unjustified assumptions of model linearity and additivity. Global approaches to sensitivity analyses (GSA) which would obviate these shortcomings, are applied by a minority of researchers. By reviewing the academic literature on SA, we here present a bibliometric analysis of the trends of different SA practices in last decade. The review has been conducted both on some top ranking journals (Nature and Science) and through an extended analysis in the Elsevier's Scopus database of scientific publications. After correcting for the global growth in publications, the amount of papers performing a generic SA has notably increased over the last decade. Even if OAT is still the most largely used technique in SA, there is a clear increase in the use of GSA with preference respectively for regression and variance-based techniques. Even after adjusting for the growth of publications in the sole modelling field, to which SA and GSA normally apply, the trend is confirmed. Data about regions of origin and discipline are also briefly discussed. The results above are confirmed when zooming on the sole articles published in chemical modelling, a field historically proficient in the use of SA methods. PMID:26934843

  9. Simulation of Drought in Central Asia during the Last Millennium

    NASA Astrophysics Data System (ADS)

    Fallah, Bijan; Polanski, Stefan; Prasad, Sushma; Cubasch, Ulrich

    2013-04-01

    Within the Central Asian Climate Dynamics project (CADY), we aim to apply multiproxy reconstructions and climate models to analyse and (semi)quantify the Last Millennium climate variability and regional hydrology in Central Asia. In this context, we have used simulations of the uncoupled atmosphere version of global COSMOS Model (ECHAM5) in T31L19 spatial resolution within the Last Millennium; Medieval Warm Period (MWP; 900-1100 AD), the Little Ice Age (LIA; 1515-1715 AD) and after industrialization (REC; 1800-2000 AD) to drive the COSMO-CLM regional climate model at its lateral boundaries for 30 year time-slices based on the definition of extreme spells in the past climate. The Palmer Drought Severity Index over Central Asia has been calculated for both global and regional simulations. The simulated PDSI from COSMO-CLM driven by ERA-INTERIM data shows very good agreements compared to observations (PDSI from Dai et al., 2004) in space-time-frequency. Based on the EOF analysis, the simulated drought patterns are well captured compared to the reconstructed PDSI from Cook et al., 2010 ( pattern correlation = 0.68 (0.83) for LIA(REC) at a 99% significance level). Further, historical droughts can be identified by the simulated PDSI (e.g. Ming Dynasty Drought and The Great Drought). The Principal Components of simulated PDSI also show significant correlations with SST anomalies for the period from 1856 to 2000.

  10. Extensive glaciation in Transbaikalia, Siberia, at the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Margold, Martin; Jansen, John D.; Gurinov, Artem L.; Codilean, Alexandru T.; Fink, David; Preusser, Frank; Reznichenko, Natalya V.; Mifsud, Charles

    2016-01-01

    Successively smaller glacial extents have been proposed for continental Eurasia during the stadials of the last glacial period leading up to the Last Glacial Maximum (LGM). At the same time the large mountainous region east of Lake Baikal, Transbaikalia, has remained unexplored in terms of glacial chronology despite clear geomorphological evidence of substantial past glaciations. We have applied cosmogenic 10Be exposure dating and optically stimulated luminescence to establish the first quantitative glacial chronology for this region. Based on eighteen exposure ages from five moraine complexes, we propose that large mountain ice fields existed in the Kodar and Udokan mountains during Oxygen Isotope Stage 2, commensurate with the global LGM. These ice fields fed valley glaciers (>100 km in length) reaching down to the Chara Depression between the Kodar and Udokan mountains and to the valley of the Vitim River northwest of the Kodar Mountains. Two of the investigated moraines date to the Late Glacial, but indications of incomplete exposure among some of the sampled boulders obscure the specific details of the post-LGM glacial history. In addition to the LGM ice fields in the highest mountains of Transbaikalia, we report geomorphological evidence of a much more extensive, ice-cap type glaciation at a time that is yet to be firmly resolved.

  11. Dynamics and development of the last North Sea ice sheet

    NASA Astrophysics Data System (ADS)

    Nygård, A.; Sejrup, H. P.; Haflidason, H.

    2008-12-01

    The last decade there has been an increasing attention on the dynamics and history of the marine based parts of the large Pleistocene ice sheets. This interest has grown both from the potential influence the stability of these features could have on ocean circulation through rapid meltwater delivery and from the understanding of the critical role these parts have in terms of the dynamics of the large ice sheets. During the last glacial stage the northern North Sea has experienced a number of glacial advances of ice from UK and Fennoscandia. Acoustic data and core data from two contrasting areas are presented. The Norwegian Channel represents the highly dynamic ice stream system draining large parts of the southern Fennoscandian ice sheet. The adjacent Witch Ground basin shows in contrast evidence of smaller scale tidewater glaciers active in a shallow environment, which constituted the eastern limit of the north-eastern British Ice sheet during the deglaciation. Seabed imagery (Olex data) reveals fresh glacial morphology inside (west of) the interpreted ice limits, while the seabed outside (east of) the interpreted ice limits shows very few features, due to a thick cover of glacimarine sediments. The seabed imprint of these systems as well as geometry, genesis and chronology of the sediments from this region will be discussed and their implications for our understanding of the glacial development of the region will be explored.

  12. Cross-latitudinal climate teleconnections during the last interglacial

    NASA Astrophysics Data System (ADS)

    Bauch, H. A.; Kandiano, E.; Fahl, K.

    2014-12-01

    A series of climate interruptions have been noted around the last warm period (MIS5e). Some of these are particularly conspicuous and occurred during both the deglacial as well as the glacial onset. These events are often associated with iceberg/meltwater charges into the subpolar/polar North Atlantic. A new multiproxy analysis using planktic foraminiferal abundances and SSTs, abundances of alkenone compounds and alkenone SSTs, and stable O/C isotope measurements was performed for Site 975 (Balearic Basin; Western Mediterranean). Samples covered the time from late MIS 6 to early MIS 5d with emphasis on the climate progression of the last interglacial period. A number of abrupt climate changes related to alternating influence of northern nutrient rich and southern oligotrophic water masses was revealed. Among the climate fluctuations, North Atlantic events Heinrich 11 as well as cooling events C27 - C23 could all be identified. However, in comparison to the eastern North Atlantic mid-latitude region, at Site 975 events C27 and C26 seem to be significantly more pronounced. This fact, along with evidence of a two-phase climate optimum with the SST maximum reached during its later phase, implies close similarity in climate dynamics between the Western Mediterranean and the polar Nordic Seas. It is therefore proposed that the postglacial marine development in the Nordic Seas - for instance, due to presence of winter sea ice - had a strong impact on the western Mediterranean climate via meridional atmospheric circulation patterns and temperature gradients.

  13. Obliquity Control On Southern Hemisphere Climate During The Last Glacial

    PubMed Central

    Fogwill, C.J.; Turney, C.S.M.; Hutchinson, D.K.; Taschetto, A.S.; England, M.H.

    2015-01-01

    Recent paleoclimate reconstructions have challenged the traditional view that Northern Hemisphere insolation and associated feedbacks drove synchronous global climate and ice-sheet volume during the last glacial cycle. Here we focus on the response of the Patagonian Ice Sheet, and demonstrate that its maximum expansion culminated at 28,400 ± 500 years before present (28.4 ± 0.5 ka), more than 5,000 years before the minima in 65°N summer insolation and the formally-defined Last Glacial Maximum (LGM) at 21,000 ± 2,000 years before present. To investigate the potential drivers of this early LGM (eLGM), we simulate the effects of orbital changes using a suite of climate models incorporating prescribed and evolving sea-ice anomalies. Our analyses suggest that Antarctic sea-ice expansion at 28.5 ka altered the location and intensity of the Southern Hemisphere storm track, triggering regional cooling over Patagonia of 5°C that extends across the wider mid-southern latitudes. In contrast, at the LGM, continued sea-ice expansion reduced regional temperature and precipitation further, effectively starving the ice sheet and resulting in reduced glacial expansion. Our findings highlight the dominant role that orbital changes can play in driving Southern Hemisphere glacial climate via the sensitivity of mid-latitude regions to changes in Antarctic sea-ice extent. PMID:26115344

  14. Western Arctic Ocean temperature variability during the last 8000 years

    USGS Publications Warehouse

    Farmer, Jesse R.; Cronin, Thomas M.; De Vernal, Anne; Dwyer, Gary S.; Keigwin, Loyd D.; Thunell, Robert C.

    2011-01-01

    We reconstructed subsurface (∼200–400 m) ocean temperature and sea-ice cover in the Canada Basin, western Arctic Ocean from foraminiferal δ18O, ostracode Mg/Ca ratios, and dinocyst assemblages from two sediment core records covering the last 8000 years. Results show mean temperature varied from −1 to 0.5°C and −0.5 to 1.5°C at 203 and 369 m water depths, respectively. Centennial-scale warm periods in subsurface temperature records correspond to reductions in summer sea-ice cover inferred from dinocyst assemblages around 6.5 ka, 3.5 ka, 1.8 ka and during the 15th century Common Era. These changes may reflect centennial changes in the temperature and/or strength of inflowing Atlantic Layer water originating in the eastern Arctic Ocean. By comparison, the 0.5 to 0.7°C warm temperature anomaly identified in oceanographic records from the Atlantic Layer of the Canada Basin exceeded reconstructed Atlantic Layer temperatures for the last 1200 years by about 0.5°C.

  15. Multiple Pathways to Long-lasting Phrenic Motor Facilitation

    PubMed Central

    Dale-Nagle, Erica A.; Hoffman, Michael S.; MacFarlane, Peter M.; Mitchell, Gordon S.

    2010-01-01

    Plasticity is a hallmark of neural systems, including the neural system controlling breathing (Mitchell and Johnson, 2003). Despite its biological and potential clinical significance, our understanding of mechanisms giving rise to any form of respiratory plasticity remains incomplete. Here we discuss recent advances in our understanding of cellular mechanisms giving rise to phrenic long-term facilitation (pLTF), a long-lasting increase in phrenic motor output induced by acute intermittent hypoxia (AIH). Recently, we have come to realize that multiple, distinct mechanisms are capable of giving rise to long-lasting phrenic motor facilitation (PMF); we use PMF as a general term that includes AIH-induced pLTF. It is important to begin an appreciation and understanding of these diverse pathways. Hence, we introduce a nomenclature based on upstream steps in the signaling cascade leading to PMF. Two pathways are featured here: the “Q” and the “S” pathways, named because they are induced by metabotropic receptors coupled to Gq and Gs proteins, respectively. These pathways appear to interact in complex and interesting ways, thus providing a range of potential responses in the face of changing physiological conditions or the onset of disease. PMID:20217354

  16. Terrestrial biosphere changes over the last 120 kyr

    NASA Astrophysics Data System (ADS)

    Hoogakker, B. A. A.; Smith, R. S.; Singarayer, J. S.; Marchant, R.; Prentice, I. C.; Allen, J. R. M.; Anderson, R. S.; Bhagwat, S. A.; Behling, H.; Borisova, O.; Bush, M.; Correa-Metrio, A.; de Vernal, A.; Finch, J. M.; Fréchette, B.; Lozano-Garcia, S.; Gosling, W. D.; Granoszewski, W.; Grimm, E. C.; Grüger, E.; Hanselman, J.; Harrison, S. P.; Hill, T. R.; Huntley, B.; Jiménez-Moreno, G.; Kershaw, P.; Ledru, M.-P.; Magri, D.; McKenzie, M.; Müller, U.; Nakagawa, T.; Novenko, E.; Penny, D.; Sadori, L.; Scott, L.; Stevenson, J.; Valdes, P. J.; Vandergoes, M.; Velichko, A.; Whitlock, C.; Tzedakis, C.

    2016-01-01

    A new global synthesis and biomization of long (> 40 kyr) pollen-data records is presented and used with simulations from the HadCM3 and FAMOUS climate models and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial-interglacial cycle. Simulated biome distributions using BIOME4 driven by HadCM3 and FAMOUS at the global scale over time generally agree well with those inferred from pollen data. Global average areas of grassland and dry shrubland, desert, and tundra biomes show large-scale increases during the Last Glacial Maximum, between ca. 64 and 74 ka BP and cool substages of Marine Isotope Stage 5, at the expense of the tropical forest, warm-temperate forest, and temperate forest biomes. These changes are reflected in BIOME4 simulations of global net primary productivity, showing good agreement between the two models. Such changes are likely to affect terrestrial carbon storage, which in turn influences the stable carbon isotopic composition of seawater as terrestrial carbon is depleted in 13C.

  17. The Last Descendant of Tycho Brahe Lives in Romania

    NASA Astrophysics Data System (ADS)

    Stavinschi, M.

    On 24 October 1601 passed away, in the 55th year of his life, the great astronomer Tycho Brahe. Now, four centuries since his death, his last descendant is living in Romania: Lydia Baroness Løvendal-Papae. An encyclopedic culture and training as hers can rarely be found today; she also is an excellent specialist in genealogy and heraldry. She has not only the merit of studying the cosmic symbols in heraldry, but especially that of establishing the genealogical tree of the famous Danish astronomer. She also holds a genealogical record: as the last descendant of the old Danish dynasty, she descends from all European dynasties, including the founders of the Romanian countries. We shall dwell here neither upon the great personality of Tycho Brahe, nor on his role in the modern astronomy. We shall not refer to the Tycho catalogue resulted from the space mission Hipparcos. We shall dwell upon the ancient aristocratic family Brahe. The oldest firm mention goes as far back as in 1364, but there are data enough on the existence of some members of this family in the 13th century. The Brahe family was related to a no less famous family, that of the Barons Løvendal. One of the ancestors of Lydia Baroness Løvendal is the renowned Ulrik Frederik Voldemar, Baron, then Count Lovendal, marshal of France (1700-1755), whose name was assigned to one of the most important boulevards of Paris.

  18. Progress in thermal comfort research over the last twenty years.

    PubMed

    de Dear, R J; Akimoto, T; Arens, E A; Brager, G; Candido, C; Cheong, K W D; Li, B; Nishihara, N; Sekhar, S C; Tanabe, S; Toftum, J; Zhang, H; Zhu, Y

    2013-12-01

    Climate change and the urgency of decarbonizing the built environment are driving technological innovation in the way we deliver thermal comfort to occupants. These changes, in turn, seem to be setting the directions for contemporary thermal comfort research. This article presents a literature review of major changes, developments, and trends in the field of thermal comfort research over the last 20 years. One of the main paradigm shift was the fundamental conceptual reorientation that has taken place in thermal comfort thinking over the last 20 years; a shift away from the physically based determinism of Fanger's comfort model toward the mainstream and acceptance of the adaptive comfort model. Another noticeable shift has been from the undesirable toward the desirable qualities of air movement. Additionally, sophisticated models covering the physics and physiology of the human body were developed, driven by the continuous challenge to model thermal comfort at the same anatomical resolution and to combine these localized signals into a coherent, global thermal perception. Finally, the demand for ever increasing building energy efficiency is pushing technological innovation in the way we deliver comfortable indoor environments. These trends, in turn, continue setting the directions for contemporary thermal comfort research for the next decades. PMID:23590514

  19. Surface Temperature Reconstructions for the Last 1000 Years

    NASA Astrophysics Data System (ADS)

    North, G. R.

    2006-12-01

    This is a presentation of results from a recently released report written by a committee established by the National Research Council and chaired by the speaker. The report was titled the same as the title of this talk. It focused on the methods of reconstructing the large scales of such surface temperature fields, since there has been considerable discussion in the scientific literature, assessments such as the IPCC, the popular press, blogs and even Congressional Hearings. The so-called `hockey stick' curve indicating a gradual cooling from the beginning of the record at about 1000AD to roughly 150 years ago when the curve take a steep upward trend (the so-called global warming). The original publications by Mann, Bradley and Hughes were careful to present and emphasize error margins that have been ignored by many in the controversy. The Committee found that numerous subsequent publications have reported reconstructions that utilized different data and different statistical assumptions. These all fall within the error margins of the original studies. While the committee has some reservations about the period prior to the year 1600AD, it still concludes that it is plausible that surface temperatures averaged over the Northern Hemisphere over the last three decades are plausibly the warmest for any such comparable period in the last 1000 years.

  20. Obliquity Control on Southern Hemisphere Climate during the Last Glacial

    NASA Astrophysics Data System (ADS)

    Fogwill, C. J.; Hutchinson, D. K.; Turney, C. S.; Taschetto, A.; England, M. H.

    2015-12-01

    Recent paleoclimate reconstructions have challenged the traditional view that Northern Hemisphere insolation and associated feedbacks drove synchronous global climate and ice-sheet volume during the last glacial cycle. Here we focus on the response of the Patagonian Ice Sheet, and demonstrate that its maximum expansion culminated at 28,400 ± 500 years before present (28.4 ± 0.5 ka), more than 5,000 years before the minima in 65°N summer insolation and the formally-defined Last Glacial Maximum (LGM) at 21,000 ± 2,000 years before present. To investigate the potential drivers of this early LGM (eLGM), we simulate the effects of orbital changes using a suite of climate models incorporating prescribed and evolving sea-ice anomalies. Our analyses suggest that Antarctic sea-ice expansion at 28.5 ka altered the location and intensity of the Southern Hemisphere storm track, triggering regional cooling over Patagonia of 5°C that extends across the wider mid-southern latitudes. In contrast, at the LGM, continued sea-ice expansion reduced regional temperature and precipitation further, effectively starving the ice sheet and resulting in reduced glacial expansion. Our findings highlight the dominant role that orbital changes can play in driving Southern Hemisphere glacial climate via the sensitivity of mid-latitude regions to changes in Antarctic sea-ice extent.

  1. Reconstructing the last Newfoundland Ice Sheet,Canada.

    NASA Astrophysics Data System (ADS)

    McHenry, Maureen; Dunlop, Paul

    2015-04-01

    The Newfoundland Ice Sheet which formed part of the North American Ice Sheet Complex was situated on the margins of the northwest Atlantic Ocean during the Wisconsinan glaciation (~80ka BP to 10ka BP). This complex consisted of the Laurentide, the Cordilleran and Innuitian Ice Sheets, the Canadian Maritime Provinces Ice Cover and the Newfoundland Ice Sheet (NIS). Although all were confluent at the last glacial maximum, the NIS is known to have supported independent ice centres with advances from the Laurentide Ice Sheet being restricted to Newfoundland's northern and western margins. Given its distinctive position, it is likely the evolution of the NIS through the last glacial cycle was influenced by a number of external and internal drivers including configuration changes in the Laurentide Ice Sheet, ice stream initiation and shutdown, changes in oceanic circulation and fluctuating sea levels and climate signals from the wider Amphi-North Atlantic. As such Newfoundland is a key location for investigating ice sheet response to a number of internal and external forcing mechanisms during glacial cycles. An established technique for reconstructing former ice sheet behaviour is the mapping and spatial analysis of glacial landforms. This provides a valuable record of former ice sheet extent and behaviour through time as well as ice sheet retreat during deglaciation. Here we present new mapping based on our interpretation of SPOT satellite imagery and Digital Elevation Models of the entire Island of Newfoundland as well as swath bathymetric imagery from several locations offshore. Our new database consisting of ~150,000 individually mapped subglacial bedforms that includes drumlins, crag and tails, glacially moulded bedrock lineations and ribbed moraines significantly increases the known landform record in this region. The new database shows Newfoundland has a complex palimpsest landscape that records multiple ice sheet events across the island. Here we report our

  2. Food transitions in last 50 years and related environmental implications

    NASA Astrophysics Data System (ADS)

    Pradhan, P.; Reusser, D. E.; Kropp, J. P.

    2012-04-01

    Food production is an important driver for global change processes such as land use change and green-house-gas emissions. We analyzed a global, long term data set on food consumption per country to identify typical patterns of diets for the last 50 years. From changes in these patterns, we derived food transitions on a global scale. Subsequently we assessed the environmental consequences from green-house-gas (GHG) emission and anthropogenic inputs. More specifically, we applied Self Organizing Maps (SOM) to identify the dietary patterns based on supply of 12 food groups from FAOSTAT dataset for a period 1961-2007. Using the data on energy output/input ratio for crop production and agricultural emission, we estimated fossil energy and GHG emission associated with the diets. We found 16 typical consumption patterns consisting of high, moderate, low and lowest calorie supply with varied food compositions. The high calorie diets are associated with a higher supply of cereals, animal-products, vegetable-oils and sugar-sweeteners featuring a total supply greater than 2800 kcal/cap/day. During the last 50 years, we observed food transitions from lower calories diets to higher calories diets. On the one hand, food transition towards affluent diet, sometime with shortcuts, occurred in developing countries. On the other hand, developed countries increased consumption of fruits and vegetables. Some of the developing countries are also stagnated in the low consumption level during the last 50 years. The high calorie diets also embed higher fossil energy (1800-3500 kcal/cap/day) and are associated with higher GHG emissions (3.7-6.1 kg CO2 eq/cap/day). However, their non-CO2 GHG emission intensities per kilo calorie of food are relatively low. Changes in dietary patterns are a part of the global change processes. Identification of past transitions is way to predict possible future transitions. This in turn supports policy processes and negotiations in the fields of climate

  3. Hydroclimate variability in NE Brazil over the last 2K

    NASA Astrophysics Data System (ADS)

    Giselle, Utida; Ioanna, Bouloubassi; Francisco, Cruz; Enno, Schefuβ; Abdel, Sifeddine; Vincent, Klein; Johan, Etourneau; Renata, Zocatelli; André, Zular; Hai, Cheng; Laurence, Edwards R.

    2016-04-01

    Precipitation associated with the South American Summer Monsoon (SASM) and the Intertropical Convergence Zone (ITCZ) supplies more than 70% of tropical South America's annual precipitation and is fundamental in sustaining the water regime for regional socioeconomic activities. Motivated by the fact that the greatest uncertainty in model projections of future precipitation trends lies in the tropics, and particularly in South America, a number of recent proxy and modeling studies have aimed at understanding SASM spatiotemporal variability regarding its dynamics, driving mechanisms and teleconnections. Exact reconstructions of past meridional ITCZ displacements (timing, sign, amplitude), however, are currently lacking, mainly because of the paucity of suited high-resolution archives. This restricts our ability to assess regional rainfall variability at decadal to centennial timescales, especially in the hydroclimatic-sensitive semi-arid Nordeste, needed to understand the interactions between SASM and ITCZ and to evaluate the impact of Pacific-Atlantic climate interactions on the regional rainfall variability at decadal/multi-decadal scale. Here we present two new and complementary high-resolution records of past precipitation over the last 2K from the north area of Nordeste, an area ideally located to track fluctuations in the southernmost edge of ITCZ movement. We present a new δO18 record from a local speleothem and combine it, for the first time, with δD analyses of wax lipids in well-dated sediments from a nearby lake. The two independent records show a remarkable similarity and are characterized by strong decadal to multidecadal variability as well as century-scale changes. The period 250-450 yrs CE appears as the wettest phase over the last 2K, while the Medieval Climate Anomaly (MCA) is characterized by extremely dry conditions. Following the MCA, the Little Ice Age (LIA) is a relatively wetter phase. The data document fluctuations of southern meridional

  4. Deciphering the evolution of the last Eurasian ice sheets

    NASA Astrophysics Data System (ADS)

    Hughes, Anna; Gyllencreutz, Richard; Mangerud, Jan; Svendsen, John Inge

    2016-04-01

    Glacial geologists need ice sheet-scale chronological reconstructions of former ice extent to set individual records in a wider context and compare interpretations of ice sheet response to records of past environmental changes. Ice sheet modellers require empirical reconstructions on size and volume of past ice sheets that are fully documented, specified in time and include uncertainty estimates for model validation or constraints. Motivated by these demands, in 2005 we started a project (Database of the Eurasian Deglaciation, DATED) to compile and archive all published dates relevant to constraining the build-up and retreat of the last Eurasian ice sheets, including the British-Irish, Scandinavian and Svalbard-Barents-Kara Seas ice sheets (BIIS, SIS and SBKIS respectively). Over 5000 dates were assessed for reliability and used together with published ice-sheet margin positions to reconstruct time-slice maps of the ice sheets' extent, with uncertainty bounds, every 1000 years between 25-10 kyr ago and at four additional periods back to 40 kyr ago. Ten years after the idea for a database was conceived, the first version of results (DATED-1) has now been released (Hughes et al. 2016). We observe that: i) both the BIIS and SBKIS achieve maximum extent, and commence retreat earlier than the larger SIS; ii) the eastern terrestrial margin of the SIS reached its maximum extent up to 7000 years later than the westernmost marine margin; iii) the combined maximum ice volume (~24 m sea-level equivalent) was reached c. 21 ka; iv) large uncertainties exist; predominantly across marine sectors (e.g. the timing of coalescence and separation of the SIS and BKIS) but also in well-studied areas due to conflicting yet equally robust data. In just three years since the DATED-1 census (1 January 2013), the volume of new information (from both dates and mapped glacial geomorphology) has grown significantly (~1000 new dates). Here, we present the DATED-1 results in the context of the

  5. For the first fracture to be the last

    PubMed Central

    Stolnicki, Bernardo; Oliveira, Lindomar Guimarães

    2016-01-01

    Increased longevity has made progression in the number of fractures increasingly significant. Because hip fractures give rise to high morbidity and mortality rates and have high treatment costs, their occurrence is the most important marker of effectiveness in relation to osteoporosis treatment. In countries and systems that, especially over the last decade, have been investing in the prevention of osteoporosis and its consequences, the number of hip fractures has been decreasing. What these countries have in common is secondary prevention of fractures, i.e. to avoid subsequent fractures. Given that half of the patients who present hip fractures have had a previous fracture and that the treatments available have proven to be extremely efficient for decreasing subsequent fractures, a good proportion of hip fractures are preventable. It is within this scenario that orthopedists play a leading role. PMID:27069877

  6. The Last Possible Outposts for Life on Mars.

    PubMed

    Davila, Alfonso F; Schulze-Makuch, Dirk

    2016-02-01

    The evolution of habitable conditions on Mars is often tied to the existence of aquatic habitats and largely constrained to the first billion years of the planet. Here, we propose an alternate, lasting evolutionary trajectory that assumes the colonization of land habitats before the end of the Hesperian period (ca. 3 billion years ago) at a pace similar to life on Earth. Based on the ecological adaptations to increasing dryness observed in dryland ecosystems on Earth, we reconstruct the most likely sequence of events leading to a late extinction of land communities on Mars. We propose a trend of ecological change with increasing dryness from widespread edaphic communities to localized lithic communities and finally to communities exclusively found in hygroscopic substrates, reflecting the need for organisms to maximize access to atmospheric sources of water. If our thought process is correct, it implies the possibility of life on Mars until relatively recent times, perhaps even the present. PMID:26836457

  7. Scientific Discoveries: What Is Required for Lasting Impact.

    PubMed

    Lømo, Terje

    2016-01-01

    I have been involved in two scientific discoveries of some impact. One is the discovery of long-term potentiation (LTP), the phenomenon that brief, high-frequency impulse activity at synapses in the brain can lead to long-lasting increases in their efficiency of transmission. This finding demonstrated that synapses are plastic, a property thought to be necessary for learning and memory. The other discovery is that nerve-evoked muscle impulse activity, rather than putative trophic factors, controls the properties of muscle fibers. Here I describe how these two discoveries were made, the unexpected difficulties of reproducing the first discovery, and the controversies that followed the second discovery. I discuss why the first discovery took many years to become generally recognized, whereas the second caused an immediate sensation and entered textbooks and major reviews but is now largely forgotten. In the long run, discovering a new phenomenon has greater impact than falsifying a popular hypothesis. PMID:26273911

  8. Does income inequality have lasting effects on health and trust?

    PubMed

    Rözer, Jesper Jelle; Volker, Beate

    2016-01-01

    According to the income inequality hypothesis, income inequality is associated with poorer health. One important proposed mechanism for this effect is reduced trust. In this study, we argue that income inequality during a person's formative years (i.e., around age 16) may have lasting consequences for trust and health. Multilevel analyses of data from the combined World Values Survey and European Values Study that were collected between 1981 and 2014 support our prediction and show that income inequality is associated with ill health in young adults, in part because it reduces their social trust. The negative consequences of income inequality remain stable for a substantial period of life but eventually fade away and have no effect after age 36. PMID:26704353

  9. Modeling East African tropical glaciers during the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Doughty, Alice; Kelly, Meredith; Russell, James; Jackson, Margaret; Anderson, Brian; Nakileza, Robert

    2016-04-01

    The timing and magnitude of tropical glacier fluctuations since the last glacial maximum could elucidate how climatic signals transfer between hemispheres. We focus on ancient glaciers of the East African Rwenzori Mountains, Uganda/D.R. Congo, where efforts to map and date the moraines are on-going. We use a coupled mass balance - ice flow model to infer past climate by simulating glacier extents that match the mapped and dated LGM moraines. A range of possible temperature/precipitation change combinations (e.g. -15% precipitation and -7C temperature change) allow simulated glaciers to fit the LGM moraines dated to 20,140±610 and 23,370±470 years old.

  10. Characterizing Interplanetary Structures of Long-Lasting Ionospheric Storm Events

    NASA Astrophysics Data System (ADS)

    Tandoi, C.; Dong, Y.; Ngwira, C. M.; Damas, M. C.

    2015-12-01

    Geomagnetic storms can result in periods of heightened TEC (Total Electron Content) in Earth's ionosphere. These periods of change in TEC (dTEC) can have adverse impacts on a technological society, such as scintillation of radio signals used by communication and navigation satellites. However, it is unknown which exact properties of a given storm cause dTEC. We are comparing different solar wind properties that result in a significant long-lasting dTEC to see if there are any patterns that remain constant in these storms. These properties, among others, include the interplanetary magnetic field By and Bz components, the proton density, and the flow speed. As a preliminary investigation, we have studied 15 solar storms. Preliminary results will be presented. In the future, we hope to increase our sample size and analyze over 80 different solar storms, which result in significant dTEC.

  11. Two possible source regions for central Greenland last glacial dust

    NASA Astrophysics Data System (ADS)

    Újvári, Gábor; Stevens, Thomas; Svensson, Anders; Klötzli, Urs S.; Manning, Christina; Németh, Tibor; Kovács, János; Sweeney, Mark R.; Gocke, Martina; Wiesenberg, Guido L. B.; Markovic, Slobodan B.; Zech, Michael

    2015-12-01

    Dust in Greenland ice cores is used to reconstruct the activity of dust-emitting regions and atmospheric circulation. However, the source of dust material to Greenland over the last glacial period is the subject of considerable uncertainty. Here we use new clay mineral and <10 µm Sr-Nd isotopic data from a range of Northern Hemisphere loess deposits in possible source regions alongside existing isotopic data to show that these methods cannot discriminate between two competing hypothetical origins for Greenland dust: an East Asian and/or central European source. In contrast, Hf isotopes (<10 µm fraction) of loess samples show considerable differences between the potential source regions. We attribute this to a first-order clay mineralogy dependence of Hf isotopic signatures in the finest silt/clay fractions, due to absence of zircons. As zircons would also be absent in Greenland dust, this provides a new way to discriminate between hypotheses for Greenland dust sources.

  12. A Global Ocean State Estimate at the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Amrhein, D. E.; Wunsch, C. I.

    2015-12-01

    Many features of Earth's climate at the Last Glacial Maximum (LGM, ca. 20,000 years ago) remain a mystery, including the role of the ocean circulation in transporting thermal energy, salinity, and other tracers. Most efforts at reconstructing the ocean state during the LGM have relied either upon integrations of general circulation models under prescribed LGM boundary conditions or the interpretation of climate proxy records without explicit physical constraints. Here we describe a global, primitive equation simulation of the LGM ocean with boundary conditions (wind, surface air temperature, and other atmospheric variables) and mixing parameters derived by a least-squares fit of an ocean general circulation model to observations of deep ocean stable isotopes and sea surface temperatures at the LGM.

  13. On thermal expansion over the last hundred years

    SciTech Connect

    De Wolde, J.R.; Bintanja, R.; Oerlemans, J.

    1995-11-01

    Estimates of sea level rise during the period 1856-1991 due to thermal expansion are presented. The estimates are based on an ocean model that consists of three zonally averaged ocean basins representing the Atlantic, Pacific, and Indian Oceans. These basins are connected by a circumpolar basin that represents the Southern Ocean. The ocean circulation in the model was prescribed. Surface ocean forcing was calculated from observed sea surface temperatures. Global mean forcing and regionally varying forcing were distinguished. Different parameterizations of ocean heat mixing were incorporated. According to the model presented, global mean sea level rise caused by thermal expansion over the last hundred years ranged from 2.2 to 5.1 cm, a best estimate being 3.5 cm. 34 refs., 5 figs.

  14. The last total solar eclipse of the millennium in Turkey

    NASA Astrophysics Data System (ADS)

    Ozguc, A.; Atac, T.; Altas, L.

    1999-03-01

    The last total solar eclipse of the millennium will be observed from Turkey which bridges two continents and has been the cradle of so many past civilizations. Wouldn't you like to witness this magnificent event in the mystic ambiance of central Anatolia which offers its guests Turkish hospitality and a lot of historical examples of paganism, Christianity and Islam. Among the countries from which the eclipse will be visible, Turkey seems to be one of the most suitable countries in terms of its climate and observational facilities. Kandilli Observatory and Earthquake Research Institute has arranged fieldwork on the eclipse path to determine the suitable points for the observations. The shadow of the moon will be first seen from the Black Sea coast at 14:20 L.T. It will then pass through central Anatolia and will leave Turkey from south-east at 14:42 L.T.

  15. Solar total and spectral irradiance reconstruction over last 9000 years

    NASA Astrophysics Data System (ADS)

    Wu, Chi-Ju; Usoskin, Ilya; Krivova, Natalie; Solanki, Sami K.

    2016-07-01

    Although the mechanisms of solar influence on Earth climate system are not yet fully understood, solar total and spectral irradiance are considered to be among the main determinants. Solar total irradiance is the total flux of solar radiative energy entering Earth's climate system, whereas the spectral irradiance describes this energy is distributed over the spectrum. Solar irradiance in the UV band is of special importance since it governs chemical processes in the middle and upper atmosphere. On timescales of the 11-year solar cycle and shorter, solar irradiance is measured by space-based instruments while models are needed to reconstruct solar irradiance on longer timescale. The SATIRE-M model (Spectral And Total Irradiance Reconstruction over millennia) is employed in this study to reconstruct solar irradiance from decadal radionuclide isotope data such as 14C and 10Be stored in tree rings and ice cores, respectively. A reconstruction over the last 9000 years will be presented.

  16. Milankovitch forcing of the last interglacial sea level.

    PubMed

    Crowley, T J; Kim, K Y

    1994-09-01

    During the last interglacial, sea level was as high as present, 4000 to 6000 years before peak Northern Hemisphere insolation receipt 126,000 years ago. The sea-level results are shown to be consistent with climate models, which simulate a 3 degrees to 4 degrees C July temperature increase from 140,000 to 130,000 years ago in high latitudes, with all Northern Hemisphere land areas being warmer than present by 130,000 years ago. The early warming occurs because obliquity peaked earlier than precession and because precession values were greater than present before peak precessional forcing occurred. These results indicate that a fuller understanding of the Milankovitch-climate connection requires consideration of fields other than just insolation forcing at 65 degrees N. PMID:17801535

  17. Milankovitch forcing of the last interglacial sea level

    SciTech Connect

    Crowley, T.J.; Kim, K.Y.

    1994-09-09

    During the last interglacial, sea level was as high as present, 4000 to 6000 years before peak Northern Hemisphere insolation receipt 126,000 years ago. The sea-level results are shown to be consistent with climate models, which simulate a 3{degrees} to 4{degrees}C July temperature increase from 140,000 to 130,000 years ago in high latitudes, with all Northern Hemisphere land areas being warmer than present by 130,000 years ago. The early warming occurs because obliquity peaked earlier than precession and because precession values were greater than present before peak precessional forcing occurred. These results indicate that a fuller understanding of the Milankovitch-climate connection requires consideration of fields other than just insolation forcing at 65{degrees}N. 16 refs., 4 figs.

  18. Galaxy Evolution over the Last Eight Billion Years

    NASA Astrophysics Data System (ADS)

    Zhu, Guangtun; Blanton, M. R.; Hogg, D. W.; Eisenstein, D. J.; Coil, A. L.; Cool, R. J.; Moustakas, J.; Wong, K. C.

    2011-01-01

    We study galaxy evolution over the last eight billion years with large, deep galaxy surveys, PRIMUS, SDSS and DEEP2. Galaxies have changed dramatically over this period of time. The global star formation rate has declined by roughly an order-of-magnitude. Red galaxies have grown substantially in number and mass. Blue galaxies have faded and grown redder as their star formation rate dropped. I demonstrate these evolutionary features with new results from these surveys. I also introduce PRIMUS, the largest faint galaxy survey to date. We have measured 140,000 robust redshifts to the depths of i (AB) 23 up to z 1, covering 9.1 square degrees of the sky. I show that with the existing deep multi-wavelength imaging in PRIMUS fields we are able to study the evolution in greater detail and investigate proposed physical mechanisms responsible for the evolution.

  19. Cannabis and psychopathology: The meandering journey of the last decade

    PubMed Central

    Ghosh, Abhishek; Basu, Debasish

    2015-01-01

    Since its inception cannabis has been observed to be associated with various psycho-pathology. In this paper, the authors have reviewed the advancement made in this area over the last decade. The association between cannabis and schizophrenia has been researched more intensively. The controversy regarding the reliability, clinical utility, and the existence of a cannabis withdrawal syndrome has also been settled. Recent studies also buttressed the possibility of acute and chronic effect of cannabis on various cognitive functions. There has been a plethora of research regarding the treatment for cannabis use disorders. But the new and most interesting area of research is concentrated on the endocannabinoid system and its contribution in various psychiatric disorders. PMID:26124519

  20. Evanescent wave fluorescence biosensors: Advances of the last decade.

    PubMed

    Taitt, Chris Rowe; Anderson, George P; Ligler, Frances S

    2016-02-15

    Biosensor development has been a highly dynamic field of research and has progressed rapidly over the past two decades. The advances have accompanied the breakthroughs in molecular biology, nanomaterial sciences, and most importantly computers and electronics. The subfield of evanescent wave fluorescence biosensors has also matured dramatically during this time. Fundamentally, this review builds on our earlier 2005 review. While a brief mention of seminal early work will be included, this current review will focus on new technological developments as well as technology commercialized in just the last decade. Evanescent wave biosensors have found a wide array applications ranging from clinical diagnostics to biodefense to food testing; advances in those applications and more are described herein. PMID:26232145

  1. Distributional learning has immediate and long-lasting effects.

    PubMed

    Escudero, Paola; Williams, Daniel

    2014-11-01

    Evidence of distributional learning, a statistical learning mechanism centered on relative frequency of exposure to different tokens, has mainly come from short-term learning and therefore does not ostensibly address the development of important learning processes. The present longitudinal study examines both short- and long-term effects of distributional learning of phonetic categories on non-native sound discrimination over a 12-month period. Two groups of listeners were exposed to a two-minute distribution of auditory stimuli in which the most frequently presented tokens either approximated or exaggerated the natural production of the speech sounds, whereas a control group listened to a piece of classical music for the same length of time. Discrimination by listeners in the two distribution groups improved immediately after the short exposure, replicating previous results. Crucially, this improvement was maintained after six and 12 months, demonstrating that distributional learning has long-lasting effects. PMID:25128798

  2. Greenland temperature response to climate forcing during the last deglaciation.

    PubMed

    Buizert, Christo; Gkinis, Vasileios; Severinghaus, Jeffrey P; He, Feng; Lecavalier, Benoit S; Kindler, Philippe; Leuenberger, Markus; Carlson, Anders E; Vinther, Bo; Masson-Delmotte, Valérie; White, James W C; Liu, Zhengyu; Otto-Bliesner, Bette; Brook, Edward J

    2014-09-01

    Greenland ice core water isotopic composition (δ(18)O) provides detailed evidence for abrupt climate changes but is by itself insufficient for quantitative reconstruction of past temperatures and their spatial patterns. We investigate Greenland temperature evolution during the last deglaciation using independent reconstructions from three ice cores and simulations with a coupled ocean-atmosphere climate model. Contrary to the traditional δ(18)O interpretation, the Younger Dryas period was 4.5° ± 2°C warmer than the Oldest Dryas, due to increased carbon dioxide forcing and summer insolation. The magnitude of abrupt temperature changes is larger in central Greenland (9° to 14°C) than in the northwest (5° to 9°C), fingerprinting a North Atlantic origin. Simulated changes in temperature seasonality closely track changes in the Atlantic overturning strength and support the hypothesis that abrupt climate change is mostly a winter phenomenon. PMID:25190795

  3. Interhemispheric ice-sheet synchronicity during the last glacial maximum

    USGS Publications Warehouse

    Weber, M.E.; Clark, P.U.; Ricken, W.; Mitrovica, J.X.; Hostetler, S.W.; Kuhn, G.

    2011-01-01

    The timing of the last maximum extent of the Antarctic ice sheets relative to those in the Northern Hemisphere remains poorly understood. We develop a chronology for the Weddell Sea sector of the East Antarctic Ice Sheet that, combined with ages from other Antarctic ice-sheet sectors, indicates that the advance to and retreat from their maximum extent was within dating uncertainties synchronous with most sectors of Northern Hemisphere ice sheets. Surface climate forcing of Antarctic mass balance would probably cause an opposite response, whereby a warming climate would increase accumulation but not surface melting. Our new data support teleconnections involving sea-level forcing from Northern Hemisphere ice sheets and changes in North Atlantic deep-water formation and attendant heat flux to Antarctic grounding lines to synchronize the hemispheric ice sheets.

  4. 1. Remnants of the last lock on the George Washington ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Remnants of the last lock on the George Washington 'Potowmack Canal, just before the barge entered the Potomac River. The latter can be seen through the foliage of the tree which has grown up in the old canal bed. On the left hand side of the photograph, not shown here in its entirety, are the old iron studdings which held the gates, to permit the barges to pass easily into the river. On the right hand side of the photograph is shown the crumbling remains of the lock with their receased oval space clearly shown, into which the lock gate retrieved when the barge was lowered to the next level. The depth from the spot where the individual is shown pointing to the top of the lock, is about 24 or 25 ft., and the canal has been filled up with broken ... - Potowmack Company: Great Falls Canal, Locks No. 3, 4, 5, Great Falls, Fairfax County, VA

  5. For the first fracture to be the last.

    PubMed

    Stolnicki, Bernardo; Oliveira, Lindomar Guimarães

    2016-01-01

    Increased longevity has made progression in the number of fractures increasingly significant. Because hip fractures give rise to high morbidity and mortality rates and have high treatment costs, their occurrence is the most important marker of effectiveness in relation to osteoporosis treatment. In countries and systems that, especially over the last decade, have been investing in the prevention of osteoporosis and its consequences, the number of hip fractures has been decreasing. What these countries have in common is secondary prevention of fractures, i.e. to avoid subsequent fractures. Given that half of the patients who present hip fractures have had a previous fracture and that the treatments available have proven to be extremely efficient for decreasing subsequent fractures, a good proportion of hip fractures are preventable. It is within this scenario that orthopedists play a leading role. PMID:27069877

  6. Looking for the Last Universal Common Ancestor (LUCA)

    PubMed Central

    Koskela, Minna; Annila, Arto

    2012-01-01

    Genomic sequences across diverse species seem to align towards a common ancestry, eventually implying that eons ago some universal antecedent organism would have lived on the face of Earth. However, when evolution is understood not only as a biological process but as a general thermodynamic process, it becomes apparent that the quest for the last universal common ancestor is unattainable. Ambiguities in alignments are unavoidable because the driving forces and paths of evolution cannot be separated from each other. Thus tracking down life’s origin is by its nature a non-computable task. The thermodynamic tenet clarifies that evolution is a path-dependent process of least-time consumption of free energy. The natural process is without a demarcation line between animate and inanimate. PMID:24704844

  7. The last mile: earthquake risk mitigation assistance in developing countries.

    PubMed

    Shah, Haresh C

    2006-08-15

    Over the past few decades, we have seen many joint programmes between developed countries and developing countries to help the latter in managing their earthquake risks. These programmes span the whole spectrum of disciplines from seismology and geology to engineering, social science and economics. Many of these programmes have been effective in raising awareness, in urging governments to work towards risk reduction and in spawning an 'industry' of disaster management in many of the developing countries. However, even as these efforts proceed, we have seen death and destruction due to earthquake after earthquake in developing countries, strongly suggesting that the problems for which those assistance programmes were developed are not so effective. Therefore, it is natural to ask why this is happening. Are the assistance programmes reaching the right people? Maybe we are reaching the right people and doing the right type of things in these countries, but we have not allowed enough time for our actions to take effect. Maybe we are reaching the right people and doing the right actions for most of the miles we need to cover in helping communities mitigate their earthquake risks. However, the issue could be whether we are reaching people who represent the 'last mile' on this pathway. Here, I explore whether the work that many organizations and countries have done towards earthquake risk reduction over the past few decades in developing countries is appropriate or not. Why do we keep seeing the catastrophes of Sumatra, Chi Chi, Bhuj, Turkey, Algeria and on and on? I will articulate what I think is the problem. My contribution is intended to generate discussions, self-analysis of our approaches, what we are doing right and what we are not doing right. Hopefully such discussions will result in a better connection between the last mile and programmes around the world which are working towards earthquake risk mitigation. PMID:16844655

  8. Evidence from the Seychelles of Last Interglacial Sea Level Oscillations

    NASA Astrophysics Data System (ADS)

    Vyverberg, K.; Dutton, A.; Dechnik, B.; Webster, J.; Zwartz, D.

    2014-12-01

    Several studies indicate that sea level oscillated during Marine Isotope Stage (MIS) 5e, but the details of these scenarios, including the number of sea level oscillations, are still debated. We lack a detailed understanding of the sensitivity of the large polar ice sheets to changes in temperature that could result in eustatic sea level oscillations. Because the Seychelles are located far from the margins of the Last Glacial Maximum northern hemisphere ice sheets, they have not been subjected to glacial isostatic adjustment, and have been tectonically stable since the Last Interglacial period; therefore, they provide a robust record of eustatic sea level during MIS 5e. All of the outcrops we examined contain unconformities and/or sharp transitions between facies, though the nature of these boundaries varies between sites. In some outcrops we observed a hardground comprising fine-grained, mollusc-rich sediment layer between distinct generations of in situ coralgal framework. In one outcrop, this succession was observed twice, where two generations of reef growth were each capped by a strongly indurated fine-grained, mollusc-rich sediment layer. At the site with the greatest vertical extent of outcrop, there is a marked difference in the taxonomic composition of the coral community above and below an unconformable surface, but the indurated fine-grained, sediment layer observed elsewhere was absent. Most of the other outcrops we studied contained a common succession of facies from in situ reef units overlain by cemented coral rubble. In two dated outcrops, the age of corals above and below the rubble layer are the same age. The hardgrounds and rubble layers may represent ephemeral exposure of the reef units during two drops in sea level. The inference of multiple meter-scale oscillations during the MIS 5e highstand indicates a more dynamic cryosphere than the present interglacial, although the climatic threshold for more volatile polar ice sheets is not yet clear.

  9. Interhemispheric Ice-Sheet Synchronicity During the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Weber, M. E.; Clark, P. U.; Kuhn, G.; Ricken, W.; Sprenk, D.

    2011-12-01

    The timing of the last maximum extent of the Antarctic ice sheets relative to those in the Northern Hemisphere remains poorly understood because only a few findings with robust chronologies exist for Antarctic ice sheets. We developed a chronology for the Weddell Sea sector of the East Antarctic ice sheet that, combined with ages from other Antarctic ice-sheet sectors, indicates the advance to and retreat from their maximum extent was nearly synchronous with Northern Hemisphere ice sheets. As for the deglaciation, modeling studies suggest a late ice-sheet retreat starting around 14 ka BP and ending around 7 ka BP with a large impact of an unstable West Antarctic Ice Sheet (WAIS) and a small impact of a stable East Antarctic Ice Sheet (EAIS). However, the Weddell Sea sites studied here, as well as sites from the Scotia Sea, provide evidence that specifically the EAIS responded much earlier, possibly provided a significant contribution to the last sea-level rise, and was much more dynamic than previously thought. Deep-sea sediment sites from the central Scotia Sea "iceberg alley" show four phases of enhanced deposition of ice-rated detritus (IRD) occurred at 19.5, 16.5,14.5, and 12 ka. The first two relate to the two ice-sheet retreat signals documented for the Weddell Sea; the third phase indicates an Antarctic component to meltwater pulse 1a; the fourth phase falls roughly into period of the Younger Dryas. Our modeling studies show that surface climate forcing of Antarctic ice sheets would have likely increased ice mass balance during deglaciation, whereby a warming climate would increase accumulation but not surface melting. We propose that sea-level forcing from Northern Hemisphere ice sheets and changes in North Atlantic deepwater formation and attendant heat flux to Antarctic grounding lines provided the teleconnections to synchronize the hemispheric ice sheets.

  10. Interglacials of the last 800,000 years

    NASA Astrophysics Data System (ADS)

    Past Interglacials Working Group Of Pages

    2016-03-01

    Interglacials, including the present (Holocene) period, are warm, low land ice extent (high sea level), end-members of glacial cycles. Based on a sea level definition, we identify eleven interglacials in the last 800,000 years, a result that is robust to alternative definitions. Data compilations suggest that despite spatial heterogeneity, Marine Isotope Stages (MIS) 5e (last interglacial) and 11c (~400 ka ago) were globally strong (warm), while MIS 13a (~500 ka ago) was cool at many locations. A step change in strength of interglacials at 450 ka is apparent only in atmospheric CO2 and in Antarctic and deep ocean temperature. The onset of an interglacial (glacial termination) seems to require a reducing precession parameter (increasing Northern Hemisphere summer insolation), but this condition alone is insufficient. Terminations involve rapid, nonlinear, reactions of ice volume, CO2, and temperature to external astronomical forcing. The precise timing of events may be modulated by millennial-scale climate change that can lead to a contrasting timing of maximum interglacial intensity in each hemisphere. A variety of temporal trends is observed, such that maxima in the main records are observed either early or late in different interglacials. The end of an interglacial (glacial inception) is a slower process involving a global sequence of changes. Interglacials have been typically 10-30 ka long. The combination of minimal reduction in northern summer insolation over the next few orbital cycles, owing to low eccentricity, and high atmospheric greenhouse gas concentrations implies that the next glacial inception is many tens of millennia in the future.

  11. Last Generation Triazoles for Imported Eumycetoma in Eleven Consecutive Adults

    PubMed Central

    Crabol, Yoann; Poiree, Sylvain; Bougnoux, Marie-Elisabeth; Maunoury, Christophe; Barete, Stéphane; Zeller, Valérie; Arvieux, Cédric; Pineau, Samuel; Amazzough, Karima; Lecuit, Marc; Lanternier, Fanny; Lortholary, Olivier

    2014-01-01

    Background Optimal management of eumycetoma, a severely debilitating chronic progressive fungal infection of skin, disseminating to bone and viscera, remains challenging. Especially, optimal antifungal treatment and duration are ill defined. Methodology/Principal Findings We conducted a monocentric retrospective study of 11 imported cases of eumycetoma treated by voriconazole or posaconazole for at least 6 months. Response to treatment was assessed through evolution of clinical and magnetic resonance imaging (MRI). (1→3) ß-D-glucan (BG) and positron emission tomography using [18F] fluorodeoxyglucose (PET/CT) results were also assessed. Identified species were Fusarium solani complex (n = 3); Madurella mycetomatis, (n = 3), and Exophiala jeanselmei, (n = 1). Moreover, two coelomycetes and one phaeohyphomycetes strains without species identification were retrieved. Serum BG and PET/CT were abnormal in 7/8 and 6/6 patients tested, respectively. Patients received last generation azoles for a mean duration of 25.9±18 months. Complete response (major clinical and MRI improvement) was observed in 5/11 patients, partial response (minor MRI improvement or stable MRI findings) in 5 and failure (MRI evidence of disease progression) in one, with a 73±39 [6–132] months mean follow-up. Relapse occurred in 2 patients after treatment discontinuation. Optimal outcome was associated with fungal species, initiation of last generation triazole therapy (<65 months since first symptoms), negative serum BG and PET/CT normalization. Conclusions/Significance MRI, PET/CT and serum BG appear as promising tools to assess optimal time of antifungal treatment for eumycetoma. PMID:25299610

  12. The last large pelletron accelerator of the Herb era

    SciTech Connect

    Chopra, S.; Narayanan, M. M.; Joshi, R.; Gargari, S.; Kanjilal, D.; Datta, S. K.; Mehta, G. K.

    1999-04-26

    Prof. Ray Herb pioneered the concept and design of the tandem Pelletron accelerator in the late sixties at NEC. The 15UD Pelletron at Nuclear Science Centre (NSC), upgraded for 16MV operation using compressed geometry accelerating tubes is the last such large Pelletron. It has unique features like offset and matching quadrupoles after the stripper for charge state selection inside the high voltage terminal and consequently the option of further stripping the ion species of the selected charge states at high energy dead section, and elaborate pulsing system in the pre-acceleration region consisting of a beam chopper, a travelling wave deflector, a light ion buncher (1-80 amu) and a heavy ion buncher (>80 amu). NSC was established as a heavy ion accelerator based inter university centre in 1985. It became operational in July 1991 to cater to the research requirements of a large user community which at present includes about fifty universities, twenty-eight colleges and a dozen other academic institutes and research laboratories. The number of users in Materials and allied sciences is about 500. Various important modifications have been made to improve the performance of the accelerator in the last seven years. These include replacement of the corona voltage grading system by a resistor based one, a pick-up loop to monitor charging system performance, conversion from basic double unit structure to singlet, installation of a spiral cavity based phase detector system with post-accelerator stripper after the analyzing magnet, and a high efficiency multi harmonic buncher. Installation of a turbo pump based stripper gas recirculation system in the terminal is also planned. A brief description of utilization of the machine will be given.

  13. The last large pelletron accelerator of the Herb era

    NASA Astrophysics Data System (ADS)

    Chopra, S.; Narayanan, M. M.; Joshi, R.; Gargari, S.; Kanjilal, D.; Datta, S. K.; Mehta, G. K.

    1999-04-01

    Prof. Ray Herb pioneered the concept and design of the tandem Pelletron accelerator in the late sixties at NEC. The 15UD Pelletron at Nuclear Science Centre (NSC), upgraded for 16MV operation using compressed geometry accelerating tubes is the last such large Pelletron. It has unique features like offset and matching quadrupoles after the stripper for charge state selection inside the high voltage terminal and consequently the option of further stripping the ion species of the selected charge states at high energy dead section, and elaborate pulsing system in the pre-acceleration region consisting of a beam chopper, a travelling wave deflector, a light ion buncher (1-80 amu) and a heavy ion buncher (>80 amu). NSC was established as a heavy ion accelerator based inter university centre in 1985. It became operational in July 1991 to cater to the research requirements of a large user community which at present includes about fifty universities, twenty-eight colleges and a dozen other academic institutes and research laboratories. The number of users in Materials and allied sciences is about 500. Various important modifications have been made to improve the performance of the accelerator in the last seven years. These include replacement of the corona voltage grading system by a resistor based one, a pick-up loop to monitor charging system performance, conversion from basic double unit structure to singlet, installation of a spiral cavity based phase detector system with post-accelerator stripper after the analyzing magnet, and a high efficiency multi harmonic buncher. Installation of a turbo pump based stripper gas recirculation system in the terminal is also planned. A brief description of utilization of the machine will be given.

  14. Atmospheric Oxygen Variation Over the Last 100 Million Years

    NASA Astrophysics Data System (ADS)

    Watson, A. J.; Mills, B.; Daines, S. J.; Lenton, T. M.; Belcher, C.

    2014-12-01

    There is no agreement over how atmospheric oxygen has varied over recent Earth history. Our knowledge of past O2 concentrations relies on biogeochemical modelling, constrained by geochemical data and proxies. There are however few direct indicators of oxygen concentrations, though the presence of fossil charcoal indicates that levels have not strayed outside the "fire window", say below 16% or above 35%, during the last hundred million years. Different model predictions encompass both decreasing and increasing trends over this period however. These predictions are sensitive to weathering of continental rocks, which provide a sink for O2, but also a supply of phosphorus and sediment to the ocean, both of which increase carbon burial and thereby provide an oxygen source. Here we update our COPSE model with a more detailed treatment than hitherto, incorporating new input data, seafloor weathering processes, and different compositions and weatherability of granites and basalts. Our model suggests a broadly declining O2 trend over the late Mesozoic to present. An alternative forcing uses the phosphorus deposition curve of Follmi (1995), which is constructed from P measurements in ocean cores, and indicates P fluxes to the oceans that have varied over time by two orders of magnitude. Used to drive the model this also results in a declining long-term trend for atmospheric O2 over the last hundred million years, but with dramatic shorter-term variations superposed on the trend. These however stay (just) within the "fire window" for oxygen concentrations, and can be tentatively related to the evolution of fire adaptations in plants.

  15. A balanced JA/ABA status may correlate with adaptation to osmotic stress in Vitis cells.

    PubMed

    Ismail, Ahmed; Seo, Mitsunori; Takebayashi, Yumiko; Kamiya, Yuji; Nick, Peter

    2015-08-01

    Water-related stress is considered a major type of plant stress. Osmotic stress, in particular, represents the common part of all water-related stresses. Therefore, plants have evolved different adaptive mechanisms to cope with osmotic-related disturbances. In the current work, two grapevine cell lines that differ in their osmotic adaptability, Vitis rupestris and Vitis riparia, were investigated under mannitol-induced osmotic stress. To dissect signals that lead to adaptability from those related to sensitivity, osmotic-triggered responses with respect to jasmonic acid (JA) and its active form JA-Ile, abscisic acid (ABA), and stilbene compounds, as well as the expression of their related genes were observed. In addition, the transcript levels of the cellular homeostasis gene NHX1 were examined. The data are discussed with a hypothesis suggesting that a balance of JA and ABA status might correlate with cellular responses, either guiding cells to sensitivity or to progress toward adaptation. PMID:26277753

  16. The Last Interglacial History of the Antarctic Ice sheet

    NASA Astrophysics Data System (ADS)

    Bradley, Sarah; Siddall, Mark; Milne, Glenn A.; Masson-Delmotte, Valerie; Wolff, Eric; Hindmarsh, Richard C. A.

    2014-05-01

    In this paper we present a summary of the work which was conducted as part of the 'PAST4FUTURE -WP4.1: Sea Level and Ice sheets' project. The overall aim of this study was to understand the response of the Antarctic Ice sheet (AIS) to climate forcing during the Last interglacial (LIG) and its contribution to the observed higher than present sea level during this period. The study involved the application and development of a novel technique which combined East Antarctic stable isotope ice core data with the output from a Glacial Isostatic Adjustment (GIA) model [Bradley et al., 2012]. We investigated if the stable isotope ice core data are sensitive to detecting isostatically driven changes in the surface elevation driven by changes in the ice-loading history of the AIS and if so, could we address some key questions relating to the LIG history of the AIS. Although it is believed that the West Antarctic Ice sheet (WAIS) reduced in size during the LIG compared to the Holocene, major uncertainties and unknowns remain unresolved: Did the WAIS collapse? What would the contribution of such a collapse be the higher than present LIG eustatic sea level (ESL)? We will show that a simulated collapse of the WAIS does not generate a significant elevation driven signal at the EAIS LIG ice core sites, and as such, these ice core records cannot be used to assess WAIS stability over this period. However, we will present 'treasure maps' [Bradley et al., 2012] to identify regions of the AIS where results from geological studies and/or new paleoclimate data may be sensitive to detecting a WAIS collapse. These maps can act as a useful tool for the wider science community/field scientists as a guide to highlight sites suitable to constrain the evolution of the WAIS during the LIG. Studies have proposed that the surface temperature across the East Antarctic Ice Sheet (EAIS) was significantly warmer, 2-5°C during the LIG compared to present [Lang and Wolff, 2011]. These higher

  17. Reconstructing paleosalinity from δ18O: Coupled model simulations of the Last Glacial Maximum, Last Interglacial and Late Holocene

    NASA Astrophysics Data System (ADS)

    Holloway, Max D.; Sime, Louise C.; Singarayer, Joy S.; Tindall, Julia C.; Valdes, Paul J.

    2016-01-01

    Reconstructions of salinity are used to diagnose changes in the hydrological cycle and ocean circulation. A widely used method of determining past salinity uses oxygen isotope (δOw) residuals after the extraction of the global ice volume and temperature components. This method relies on a constant relationship between δOw and salinity throughout time. Here we use the isotope-enabled fully coupled General Circulation Model (GCM) HadCM3 to test the application of spatially and time-independent relationships in the reconstruction of past ocean salinity. Simulations of the Late Holocene (LH), Last Glacial Maximum (LGM), and Last Interglacial (LIG) climates are performed and benchmarked against existing compilations of stable oxygen isotopes in carbonates (δOc), which primarily reflect δOw and temperature. We find that HadCM3 produces an accurate representation of the surface ocean δOc distribution for the LH and LGM. Our simulations show considerable variability in spatial and temporal δOw-salinity relationships. Spatial gradients are generally shallower but within ∼50% of the actual simulated LH to LGM and LH to LIG temporal gradients and temporal gradients calculated from multi-decadal variability are generally shallower than both spatial and actual simulated gradients. The largest sources of uncertainty in salinity reconstructions are found to be caused by changes in regional freshwater budgets, ocean circulation, and sea ice regimes. These can cause errors in salinity estimates exceeding 4 psu. Our results suggest that paleosalinity reconstructions in the South Atlantic, Indian and Tropical Pacific Oceans should be most robust, since these regions exhibit relatively constant δOw-salinity relationships across spatial and temporal scales. Largest uncertainties will affect North Atlantic and high latitude paleosalinity reconstructions. Finally, the results show that it is difficult to generate reliable salinity estimates for regions of dynamic oceanography

  18. Caribbean Salinity Variation During the Last Glacial Cycle

    NASA Astrophysics Data System (ADS)

    Schmidt, M. W.; Spero, H. J.; Lea, D. W.

    2003-12-01

    Evaporation exceeds precipitation in the tropical Atlantic, resulting in a net freshwater removal across the Central American Isthmus. Because most of the north Atlantic's subtropical gyre water circulates through the Caribbean before flowing north to sub-polar regions via the Gulf Stream, changes in tropical atmospheric circulation have the potential to affect the salinity and density structure of the entire north Atlantic, thereby influencing glacial-interglacial oscillations in North Atlantic Deep Water (NADW) formation. Here, we combine Mg/Ca measurements (a proxy for the temperature of calcification) and δ 18O analyses of shells from the surface-dwelling foraminifera Globigerinoides ruber s.s. (white var.) from the western Caribbean Colombian Basin at ODP Site 999A (2827m; 4cm/ka sed. rate) and VM28-122 (3623m; 4-10cm/ka sed. rate) to produce the first continuous record of western tropical Atlantic δ 18OSEAWATER (δ 18OSW) during the last 130ka. In order to generate a record for sea surface salinity (SSS) due to regional hydrological change, we removed the δ 18OSW signal due to glacial ice volume variation and normalized the residual to the modern δ 18OSW value for the Colombian Basin (0.8‰ ). The resulting ice volume-free (Δ δ 18OIVF-SW) record shows that Caribbean Δ δ 18OIVF-SW increased by ˜0.5‰ during the Last Glacial Maximum and Marine Isotope Stage 4. Using a modern western Caribbean δ 18OSW:SSS relationship, these enriched δ 18OSW values suggest glacial Caribbean salinities were 2.3 - 2.8‰ higher than modern after removing the influence of ice-volume. Our data supports the hypothesis that the tropics might have been in a state more similar to the modern El Nino mode, characterized by a more southerly position of the ITCZ, during cold phases of the last glacial cycle. Within the resolution of our Δ δ 18OIVF-SW record from VM28-122, elevated glacial Caribbean salinity decreased to modern levels at the onset of the Bolling-Allerod (B

  19. Northern Hemisphere hydroclimate patterns in the last 12 centuries

    NASA Astrophysics Data System (ADS)

    Charpentier Ljungqvist, Fredrik; Krusic, Paul J.; Sundqvist, Hanna S.; Zorita, Eduardo; Brattström, Gudrun; Frank, David

    2015-04-01

    Variations in local to continental-scale hydroclimate have a strong impact on ecosystem functioning, crop yields, and society's water resources. Consequently, the ability to model and predict with reasonable certainty the dynamic and spatial response of precipitation to global warming is essential. The uncertainty in hydroclimate projections from model simulations remains large as a consequence of significant gaps in our knowledge of preindustrial boundary conditions due to the short length of instrumental measurements of precipitation. In this study, we assembled an unprecedentedly large network of 196 records hydroclimatic records from the Northern Hemisphere (NH) to place recent hydrological changes and future precipitation scenarios in the context of spatially resolved and temporally persistent hydroclimatic variations over the last twelve centuries. The data from grid cells corresponding to the proxy locations were obtained from six CMIP5 last millennium simulations and treated in a similar way as the proxy data in order to facilitate a model-proxy comparison. The most extensive areas of low moisture availability are found during the 12th and 15th centuries. It is notable that the intensification of wet and dry anomalies during the 20th century shown in coupled atmosphere-ocean model simulations is not supported by empirical evidence. Our results reveals that prominent hydroclimatic see-saw patterns, also observed in instrumental data, of alternating moisture regimes between the east and west Mediterranean, southwest vs. northwest United States, east vs. west China have been operating consistently during the past millennium. Key findings: - Dry as well as wet conditions can prevail under both warm and cold climate states in most regions. - In some regions a tendency can be seen for either increased aridity or wetness with increasing or decreasing temperatures. - Such changes can be expressed in localized wet-dry seesaw patterns that climate models seems unable

  20. The CMIP6/PMIP4 Last Millennium Simulations

    NASA Astrophysics Data System (ADS)

    Jungclaus, Johann

    2016-04-01

    Climate has varied considerably during the late Holocene and these changes left their traces in history (Medieval Climate Optimum, Little Ice Age). However, the relative magnitude of natural fluctuations due to internal variability of the Earth's climate system and to variations in the external forcing and the present global warming, attributed to anthropogenic greenhouse gases, is still under debate. Investigating the response to (mainly) natural forcing under climatic background conditions not too different from today is crucial for an improved understanding of climate variability, circulation, and regional connectivity. Simulations over the last millennium (LM) allow assessing climate variability on decadal and longer scales and provide information on predictability under forced and unforced conditions. In providing in-depth model evaluation with respect to observations and paleoclimatic reconstructions, LM simulations serve to understand origins and consequences of systematic model biases. PMIP4 Tier-1 includes the standard LM simulation covering 850 to 1849 CE and a subsequent "historical" (1850 - 2010 CE) experiment as a minimum requirement. In addition to changes in Earth's orbit and greenhouse gas concentrations, the models are forced by variations in solar irradiance, volcanic aerosol load, and anthropogenic land-cover. As part of Tier-2, the modeling groups are asked to provide additional simulations in the form of ensembles, single forcing experiments, as well as sensitivity runs using alternative forcing combinations. The extension of the simulations to cover the complete last two millennia (0 CE to present) is also part of Tier-2. We describe the experimental design of the LM simulations and discuss the protocol on new forcing and boundary conditions. We discuss recent advances in the reconstruction of solar, volcanic, and land-cover changes and their implementation in the CMIP6 models. PMIP4 aims to provide forcing datasets that are consistent with

  1. Flow-pattern evolution of the last British Ice Sheet

    NASA Astrophysics Data System (ADS)

    Hughes, Anna L. C.; Clark, Chris D.; Jordan, Colm J.

    2014-04-01

    We present a 10-stage reconstruction of the evolution in ice-flow patterns of the last British Ice Sheet from build-up to demise derived from geomorphological evidence. 100 flowsets identified in the subglacial bedform record (drumlins, mega-scale glacial lineations, and ribbed moraine) are combined with ancillary evidence (erratic-transport paths, absolute dates and a semi-independently reconstructed retreat pattern) to define flow patterns, ice divides and ice-sheet margins during build-up, maximum glaciation and retreat. Overprinting and cross-cutting of landform assemblages are used to define the relative chronology of flow patterns and a tentative absolute chronology is presented based on a collation of available dates for ice advance and retreat. The ice-flow configuration of the last British Ice Sheet was not static. Some ice divides were remarkably stable, persisting through multiple stages of the ice-sheet evolution, whereas others were transient features existing for a short time and/or shifting in position 10s km. The 10 reconstructed stages of ice-sheet geometry capture two main modes of operation; first as an integrated ice sheet with a broadly N-S orientated ice divide, and second as a multi-domed ice sheet orientated parallel with the shelf edge. A thick integrated ice sheet developed as ice expanded out of source areas in Scotland to envelop southerly ice caps in northern England and Wales, and connect with the Irish Ice Sheet to the west and the Scandinavian Ice Sheet across the North Sea. Following break-up of ice over the North Sea, ice streaming probably drove mass loss and ice-sheet thinning to create a more complex divide structure, where ice-flow patterns were largely controlled by the form of the underlying topography. Ice surface lowering occurred before separation of, and retreat to, multiple ice centres centred over high ground. We consider this 10-stage reconstruction of the evolution in ice-sheet configuration to be the simplest palaeo

  2. Comparative carbon cycle dynamics of the present and last interglacial

    NASA Astrophysics Data System (ADS)

    Brovkin, Victor; Brücher, Tim; Kleinen, Thomas; Zaehle, Sönke; Joos, Fortunat; Roth, Raphael; Spahni, Renato; Schmitt, Jochen; Fischer, Hubertus; Leuenberger, Markus; Stone, Emma J.; Ridgwell, Andy; Chappellaz, Jérôme; Kehrwald, Natalie; Barbante, Carlo; Blunier, Thomas; Dahl Jensen, Dorthe

    2016-04-01

    Changes in temperature and carbon dioxide during glacial cycles recorded in Antarctic ice cores are tightly coupled. However, this relationship does not hold for interglacials. While climate cooled towards the end of both the last (Eemian) and present (Holocene) interglacials, CO2 remained stable during the Eemian while rising in the Holocene. We identify and review twelve biogeochemical mechanisms of terrestrial (vegetation dynamics and CO2 fertilization, land use, wildfire, accumulation of peat, changes in permafrost carbon, subaerial volcanic outgassing) and marine origin (changes in sea surface temperature, carbonate compensation to deglaciation and terrestrial biosphere regrowth, shallow-water carbonate sedimentation, changes in the soft tissue pump, and methane hydrates), which potentially may have contributed to the CO2 dynamics during interglacials but which remain not well quantified. We use three Earth System Models (ESMs) of intermediate complexity to compare effects of selected mechanisms on the interglacial CO2 and δ13CO2 changes, focusing on those with substantial potential impacts: namely carbonate sedimentation in shallow waters, peat growth, and (in the case of the Holocene) human land use. A set of specified carbon cycle forcings could qualitatively explain atmospheric CO2 dynamics from 8 ka BP to the pre-industrial. However, when applied to Eemian boundary conditions from 126 to 115 ka BP, the same set of forcings led to disagreement with the observed direction of CO2 changes after 122 ka BP. This failure to simulate late-Eemian CO2 dynamics could be a result of the imposed forcings such as prescribed CaCO3 accumulation and/or an incorrect response of simulated terrestrial carbon to the surface cooling at the end of the interglacial. These experiments also reveal that key natural processes of interglacial CO2 dynamics - shallow water CaCO3 accumulation, peat and permafrost carbon dynamics - are not well represented in the current ESMs. Global

  3. The physiology and habitat of the last universal common ancestor.

    PubMed

    Weiss, Madeline C; Sousa, Filipa L; Mrnjavac, Natalia; Neukirchen, Sinje; Roettger, Mayo; Nelson-Sathi, Shijulal; Martin, William F

    2016-01-01

    The concept of a last universal common ancestor of all cells (LUCA, or the progenote) is central to the study of early evolution and life's origin, yet information about how and where LUCA lived is lacking. We investigated all clusters and phylogenetic trees for 6.1 million protein coding genes from sequenced prokaryotic genomes in order to reconstruct the microbial ecology of LUCA. Among 286,514 protein clusters, we identified 355 protein families (∼0.1%) that trace to LUCA by phylogenetic criteria. Because these proteins are not universally distributed, they can shed light on LUCA's physiology. Their functions, properties and prosthetic groups depict LUCA as anaerobic, CO2-fixing, H2-dependent with a Wood-Ljungdahl pathway, N2-fixing and thermophilic. LUCA's biochemistry was replete with FeS clusters and radical reaction mechanisms. Its cofactors reveal dependence upon transition metals, flavins, S-adenosyl methionine, coenzyme A, ferredoxin, molybdopterin, corrins and selenium. Its genetic code required nucleoside modifications and S-adenosyl methionine-dependent methylations. The 355 phylogenies identify clostridia and methanogens, whose modern lifestyles resemble that of LUCA, as basal among their respective domains. LUCA inhabited a geochemically active environment rich in H2, CO2 and iron. The data support the theory of an autotrophic origin of life involving the Wood-Ljungdahl pathway in a hydrothermal setting. PMID:27562259

  4. Transient Climate Simulation of the last deglaciation in CCSM3

    SciTech Connect

    He, Feng; Erickson III, David J; Jacob, Robert L.

    2009-12-01

    We conducted the first synchronously coupled atmosphere-ocean general circulation model simulation of global climate evolution of the last deglaciation (21,000-10,000 years ago) using the NCAR CCSM3. With realistic climate forcings associated with greenhouse gasses, orbital forcing and continental ice sheet, as well as a reasonable melting water forcing, our model reproduces some major deglacial climate features, such as the H1 event, the BA warming and the YD event. A preliminary model-data comparison shows a global climate evolution largely consistent with the reconstruction. The magnitude of our model climate responses are largely consistent with the reconstruction, suggesting a good agreement between observed and modeled climate sensitivity. In contrast to previous simulations of intermediate climate models, our model AMOC has little hysteresis. As a result, the model simulates the abrupt onset of the BA warming and the abrupt termination of the YD cooling as transient responses of the Atlantic meridional overturning circulation (AMOC) to abrupt terminations of freshwater discharges. Further implications to transient model-data comparison will also be discussed.

  5. Ground movement at Somma-Vesuvius from Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Marturano, Aldo; Aiello, Giuseppe; Barra, Diana; Fedele, Lorenzo; Morra, Vincenzo

    2012-01-01

    Detailed micropalaeontological and petrochemical analyses of rock samples from two boreholes drilled at the archaeological excavations of Herculaneum, ~ 7 km west of the Somma -Vesuvius crater, allowed reconstruction of the Late Quaternary palaeoenvironmental evolution of the site. The data provide clear evidence for ground uplift movements involving the studied area. The Holocenic sedimentary sequence on which the archaeological remains of Herculaneum rest has risen several meters at an average rate of ~ 4 mm/yr. The uplift has involved the western apron of the volcano and the Sebeto-Volla Plain, a populous area including the eastern suburbs of Naples. This is consistent with earlier evidence for similar uplift for the areas of Pompeii and Sarno valley (SE of the volcano) and the Somma -Vesuvius eastern apron. An axisimmetric deep source of strain is considered responsible for the long-term uplift affecting the whole Somma -Vesuvius edifice. The deformation pattern can be modeled as a single pressure source, sited in the lower crust and surrounded by a shell of Maxwell viscoelastic medium, which experienced a pressure pulse that began at the Last Glacial Maximum.

  6. The "last mile" of data handling: Fermilab's IFDH tools

    NASA Astrophysics Data System (ADS)

    Lyon, Adam L.; Mengel, Marc W.

    2014-06-01

    IFDH (Intensity Frontier Data Handling), is a suite of tools for data movement tasks for Fermilab experiments and is an important part of the FIFE[2] (Fabric for Intensity Frontier [1] Experiments) initiative described at this conference. IFDH encompasses moving input data from caches or storage elements to compute nodes (the "last mile" of data movement) and moving output data potentially to those caches as part of the journey back to the user. IFDH also involves throttling and locking to ensure that large numbers of jobs do not cause data movement bottlenecks. IFDH is realized as an easy to use layer that users call in their job scripts (e.g. "ifdh cp"), hiding the low level data movement tools. One advantage of this layer is that the underlying low level tools can be selected or changed without the need for the user to alter their scripts. Logging and performance monitoring can also be added easily. This system will be presented in detail as well as its impact on the ease of data handling at Fermilab experiments.

  7. Red long-lasting phosphorescence based on color conversion process

    NASA Astrophysics Data System (ADS)

    Li, Zhanjun; Zhang, Hongwu; Fu, Haixia

    2013-01-01

    The principle of color conversion process was used to generate red long-lasting phosphorescence (LLP) using SrAl2O4:Eu, Dy (SAO) as primary light source and rhodamine B encapsulated mesoporous silica nanoparticles (MCM-R) as effective color conversion agent. The phosphorescence spectra of MCM-R/SAO hybrid samples show green peaks from 425 nm to 550 nm and red peaks from 550 nm to 700 nm, which can be attributed to the phosphorescence of SAO and the fluorescence of MCM-R, respectively. The phosphorescence color can be adjusted from green to red by changing the mass ratio of MCM-R/SAO. When the mass ratio of MCM-R/SAO increases from 0.05 to 1.5, a blue shift for the green peak and a red shift for the red peak of the phosphorescence spectra can be observed and the intensity of the red emission peak increase relatively towards the green one. The phosphorescence decay curves show that MCM-R and SAO have similar decay dynamics and the MCM-R can inherit the LLP properties of SAO. The phosphorescence decay spectra indicate that the MCM-R/SAO hybrid can retain constant and steady visual phosphorescence color. The red phosphorescence can be seen in the dark with naked eyes for more than 5 h. So, the red LLP can be successfully achieved based on the principle of color conversion process.

  8. Dynamic simulation of stable water isotopes during the last interglacial

    NASA Astrophysics Data System (ADS)

    Gierz, P.; Lohmann, G.; Brocas, W.; Felis, T.

    2014-12-01

    Using the novel isotope module of the global fully coupled climate model COSMOS, we simulate the climate of the last interglacial for three time slices at 120, 125, and 130 kiloyears before present. The inclusion of stable water isotopes allows us to not only have a comprehensive picture of the climate state during a warm interglacial, but also allows for a direct comparison with climate proxy records. We compare our simulation with isotope data gathered from fossilized corals, which have an excellent temporal resolution and well constrained dating. A model data comparison allows us to see that there was an enhanced seasonality of both temperature and rainfall during the Eemian. While the data tends to produce a stronger winter cooling than the model, we suggest that this may be due to an incomplete climatology, as the measurements taken from the coral only encompasses a few decades. If the data happens to fall during an usually cool decade, the mismatch could be rectified. Alternatively, the data may include the cooling signal associated with centennial scale cold stadials during the Eemian. We test this by performing a freshwater perturbation experiment during the peak interglacial, which causes a pronounced cooling at the core site while the ocean circulation is depressed.

  9. Cyclic climate fluctuations during the last interglacial in central Europe

    NASA Astrophysics Data System (ADS)

    Müller, Ulrich C.; Klotz, Stefan; Geyh, Mebus A.; Pross, Jörg; Bond, Gerard C.

    2005-06-01

    Differentiating natural climate change from anthropogenic forcing is a major challenge in the prediction of future climates. In this context, the investigation of interglacials provides valuable information on natural climate variability during periods that resemble the present. This paper shows that natural cyclic changes in winter climates affected central European environments during the last interglacial, i.e., the Eemian, 126 110 ka. As a result of the extraordinarily high counting sums performed at Eemian pollen samples, it was possible to reveal a robust presence absence pattern of the insect-pollinated, and therefore in the pollen rain underrepresented, taxon Hedera. This plant is known to require the influence of oceanic winter climates, i.e., moist and mild, in northwest and central Europe. By analogy with recent findings from the North Atlantic's Holocene interglacial, the trigger of the Eemian climate variability may have been changes in solar activity, possibly amplified by changes in North Atlantic ocean currents and/or in the North Atlantic Oscillation. Our findings suggest natural cyclic changes to be a persistent feature of interglacial climates.

  10. Sea-level fluctuations during the last glacial cycle.

    PubMed

    Siddall, M; Rohling, E J; Almogi-Labin, A; Hemleben, Ch; Meischner, D; Schmelzer, I; Smeed, D A

    2003-06-19

    The last glacial cycle was characterized by substantial millennial-scale climate fluctuations, but the extent of any associated changes in global sea level (or, equivalently, ice volume) remains elusive. Highstands of sea level can be reconstructed from dated fossil coral reef terraces, and these data are complemented by a compilation of global sea-level estimates based on deep-sea oxygen isotope ratios at millennial-scale resolution or higher. Records based on oxygen isotopes, however, contain uncertainties in the range of +/-30 m, or +/-1 degrees C in deep sea temperature. Here we analyse oxygen isotope records from Red Sea sediment cores to reconstruct the history of water residence times in the Red Sea. We then use a hydraulic model of the water exchange between the Red Sea and the world ocean to derive the sill depth-and hence global sea level-over the past 470,000 years (470 kyr). Our reconstruction is accurate to within +/-12 m, and gives a centennial-scale resolution from 70 to 25 kyr before present. We find that sea-level changes of up to 35 m, at rates of up to 2 cm yr(-1), occurred, coincident with abrupt changes in climate. PMID:12815427

  11. Marine Transportation Implications of the Last Arctic Sea Ice Refuge

    NASA Astrophysics Data System (ADS)

    Brigham, L. W.

    2010-12-01

    Marine access is increasing throughout the Arctic Ocean and the 'Last Arctic Sea Ice Refuge' may have implications for governance and marine use in the region. Arctic marine transportation is increasing due to natural resource developemnt, increasing Arctic marine tourism, expanded Arctic marine research, and a general linkage of the Arctic to the gloabl economy. The Arctic Council recognized these changes with the release of the Arctic Marine Shipping Assessment of 2009. This key study (AMSA)can be viewed as a baseline assessment (using the 2004 AMSA database), a strategic guide for a host of stakeholders and actors, and as a policy document of the Arctic Council. The outcomes of AMSA of direct relevance to the Ice Refuge are within AMSA's 17 recommendations provided under three themes: Enhancing Arctic Marine Safety, Protecting Arctic People and the Environment, and Building the Arctic Marine Infrastructure. Selected recommendations of importance to the Ice Refuge include: a mandatory polar navigation code; identifying areas of heightened ecological and cultural significance; potential designation of special Arctic marine areas; enhancing the tracking and monitoring of Arctic marine traffic; improving circumpolar environmental response capacity; developing an Arctic search and rescue agreement; and, assessing the effects of marine transportation on marine mammals. A review will be made of the AMSA outcomes and how they can influence the governance, marine use, and future protection of this unique Arctic marine environment.

  12. Indian Summer Monsoon Variability during the Last Millennium

    NASA Astrophysics Data System (ADS)

    Rooker, Mary; Sinha, Ashish

    2011-11-01

    The seasonal rainfall associated with the Indian summer monsoon during the instrumental period (˜last 150 years) is characterized by a biennial oscillation, such that monsoon precipitation varied between singularly strong and weak years but rarely deviated far from its mean state for consecutive years. This observation has led to a hypothesis that monsoon is a self-regulating system, regulated by the annual cycle of the heat balance in the Indian Ocean, mediated by the cross-equatorial ocean heat transport from the summer hemisphere through wind-driven Ekman transport. Consequently, the present day water resource infrastructure and the contingency planning in the region does not take into account the possibility of protracted failures of the monsoon or drastic shifts in its spatial patterns. Here we present new millennial-length speleothem-based reconstructions of Indian monsoon variability from a number of sites across India that challenges the underlying physics of the aforementioned hypothesis. Our proxy records of Indian monsoon provide clear evidence for type of low frequency and high amplitude variability in rainfall that have not been observed during the short instrumental period.

  13. Global Connections for Lasting Impressions: Experiential Learning about TCP

    NASA Astrophysics Data System (ADS)

    Allison, Colin; Miller, Alan; Oliver, Iain; Sturgeon, Thomas

    “Tell me and I forget, Show me and I remember, Involve me and I understand”. This paper discusses the motivation for, and design of, a learning resource which allows students to explore the Transmission Control Protocol (TCP). TCP is responsible for transporting over 80% of the traffic on the Internet - all web and e-mail for example - and in addition is the primary means of achieving Internet congestion control. TCP is therefore core to modern life. It is a protocol under constant study with a view to evolution, and it is incumbent on all ICT curricula to provide education at appropriate levels about its dynamics, strengths and weaknesses. There are no shortages of good textbooks which provide information on TCP, but these are no substitute for experiential learning in order to provide a lasting understanding. The TCP Live learning resource allows students to explore the behavior of TCP on the global Internet, and see the wide variety of conditions that the protocol has to cope with, thereby extending their viewpoint outwith the limited scope of their own institutional firewalls.

  14. The 'last mile' of data handling: Fermilab's IFDH tools

    SciTech Connect

    Lyon, Adam L.; Mengel, Marc W.

    2014-01-01

    IFDH (Intensity Frontier Data Handling), is a suite of tools for data movement tasks for Fermilab experiments and is an important part of the FIFE[2] (Fabric for Intensity Frontier [1] Experiments) initiative described at this conference. IFDH encompasses moving input data from caches or storage elements to compute nodes (the 'last mile' of data movement) and moving output data potentially to those caches as part of the journey back to the user. IFDH also involves throttling and locking to ensure that large numbers of jobs do not cause data movement bottlenecks. IFDH is realized as an easy to use layer that users call in their job scripts (e.g. 'ifdh cp'), hiding the low level data movement tools. One advantage of this layer is that the underlying low level tools can be selected or changed without the need for the user to alter their scripts. Logging and performance monitoring can also be added easily. This system will be presented in detail as well as its impact on the ease of data handling at Fermilab experiments.

  15. Variability of the Indian Ocean Dipole during the last millennium

    NASA Astrophysics Data System (ADS)

    Abram, N.; Gagan, M. K.; Dixon, B.; Hantoro, W. S.; Shen, C.; WU, C.; Suwargadi, B. W.

    2013-12-01

    The Indian Ocean Dipole (IOD) climate mode interacts with the El Niño-Southern Oscillation and Asian monsoon systems to drive climatic extremes around the Indian Ocean region. Coral reconstructions of the interannual variability of the IOD since the 1850s show an intensification in the frequency and strength of the positive phase of the IOD in recent decades, as well as strengthening of the interconnection between the IOD and Asian monsoon systems. Reconstructions of the mean climate state across the tropical Indian Ocean since the mid-Holocene also demonstrate the dynamic nature of the mean configuration of tropical Indian Ocean climate, suggesting that the IOD variability and interactions observed on interannual time scales may also persist over century to millennial scales. Here we present new oxygen isotope (δ18O) records from modern Porites corals collected on a transect along Java-Sumatra coasts. These corals, located within the IOD upwelling zone, are used to identify the location where optimum information about the occurrence and magnitude of positive IOD events can be gained from single corals. Precisely-dated fossil corals from this location of optimum IOD variability are then used to reconstruct highly resolved windows of IOD variability during the last millennium, including intervals corresponding to the northern hemisphere Little Ice Age and Medieval Warm Period.

  16. Long-lasting antifog plasma modification of transparent plastics.

    PubMed

    Di Mundo, Rosa; d'Agostino, Riccardo; Palumbo, Fabio

    2014-10-01

    Antifog surfaces are necessary for any application requiring optical efficiency of transparent materials. Surface modification methods aimed toward increasing solid surface energy, even when supposed to be permanent, in fact result in a nondurable effect due to the instability in air of highly hydrophilic surfaces. We propose the strategy of combining a hydrophilic chemistry with a nanotextured topography, to tailor a long-lasting antifog modification on commercial transparent plastics. In particular, we investigated a two-step process consisting of self-masked plasma etching followed by plasma deposition of a silicon-based film. We show that the deposition of the silicon-based coatings on the flat (pristine) substrates allows a continuous variation of wettability from hydrophobic to superhydrophilic, due to a continuous reduction of carbon-containing groups, as assessed by Fourier transform infrared and X-ray photoelectron spectroscopies. By depositing these different coatings on previously nanotextured substrates, the surface wettability behavior is changed consistently, as well as the condensation phenomenon in terms of microdroplets/liquid film appearance. This variation is correlated with advancing and receding water contact angle features of the surfaces. More importantly, in the case of the superhydrophilic coating, though its surface energy decreases with time, when a nanotextured surface underlies it, the wetting behavior is maintained durably superhydrophilic, thus durably antifog. PMID:25251610

  17. The last total Eclipse of teh Millenium in Turkey

    NASA Astrophysics Data System (ADS)

    Ozguch, A.; Atac, T.; Altas, L.

    1998-09-01

    The last total solar eclipse of the millenium will be observed from Turkey which bridges two components and has been the cradle of so many past civilisations. Wouldn't you like to witness this magnificient event in the mystic ambiance of central Anatolia which offers its guests Turkish hospitality and a lot of hystorical examples of paganism, Christianity and Islam. Among the countries from which the eclipse will be visible , Turkey seems to be one of the most suitable countries in terms of its climate and observational facilities. Kandilli Observatory and the Earthquake Research Institute has arranged field work on the eclipse path to determine the suitable points for the observations. The shadow of the moon will be first seen from the Black Sea coast at 14:20 L.T. It will then pass through central Anatolia and will leave Turkey form south-east at 14:42 L.T. Official observational sites are given in the following table. These sites will have catering, toilet, and guidance facilities. Osmanchik 40.98D North 34.82D East Turhal 40.40D North 36.10D East Sivas 39.75D North 37.03D East Elazig 38.68D North 39.23D East Diyarbakir 37.92D North 40.23D East Batman 37.87 North 41.12D East

  18. Greenland ice sheet melting during the last interglacial

    NASA Astrophysics Data System (ADS)

    Langebroek, Petra M.; Nisancioglu, Kerim H.

    2016-04-01

    During the last interglacial period (LIG) peak temperatures over Greenland were several degrees warmer than today. The Greenland ice sheet (GIS) retreated causing a global sea-level rise in the order of several meters. Large uncertainties still exist in the exact amount of melt and on the source location of this melt. Here we examine the GIS response to LIG temperature and precipitation patterns using the SICOPOLIS ice sheet model. The LIG climate was simulated by forcing the Norwegian Earth System Model (NorESM) with the appropriate greenhouse gases and orbital settings. The resulting LIG ice volume evolution strongly depends on the chosen value of uncertain model parameters for the ice sheet (e.g. basal sliding parameter, PDD factors, and atmospheric temperature lapse rate). We reduce the uncertainty by evaluating an ensemble of model results against present-day observations of ice sheet size, elevation and stability, together with paleo information from deep ice cores. We find a maximum GIS reduction equivalent to 0.8 to 2.2m of global sea-level rise. In this model set-up most of the melting occurs in southwestern Greenland.

  19. Antarctic Zone nutrient conditions during the last two glacial cycles

    NASA Astrophysics Data System (ADS)

    Studer, Anja S.; Sigman, Daniel M.; Martínez-García, Alfredo; Benz, Verena; Winckler, Gisela; Kuhn, Gerhard; Esper, Oliver; Lamy, Frank; Jaccard, Samuel L.; Wacker, Lukas; Oleynik, Sergey; Gersonde, Rainer; Haug, Gerald H.

    2015-07-01

    In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (δ15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrate consumption and Antarctic climate across the last two glacial cycles, with δ15Ndb (and thus the degree of nitrate consumption) increasing at each major Antarctic cooling event. Coupled with evidence from opal- and barium-based proxies for reduced export production during ice ages, the δ15Ndb increases point to ice age reductions in the supply of deep ocean-sourced nitrate to the AZ surface. The two diatom assemblages and species abundance data indicate that the δ15Ndb changes are not the result of changing species composition. The pennate and centric assemblage δ15Ndb records indicate similar changes but with a significant decline in their difference during peak ice ages. A tentative seasonality-based interpretation of the centric-to-pennate δ15Ndb difference suggests that late summer surface waters became nitrate free during the peak glacials.

  20. Immunogenicity of long-lasting recombinant factor VIII products.

    PubMed

    Ing, Mathieu; Gupta, Nimesh; Teyssandier, Maud; Maillère, Bernard; Pallardy, Marc; Delignat, Sandrine; Lacroix-Desmazes, Sébastien

    2016-03-01

    Replacement therapy for patients with hemophilia A using plasma-derived or recombinant factor VIII (FVIII) is complicated by the short half-life of the FVIII products and by the occurrence of neutralizing antibodies in a substantial number of patients. In the recent years, enormous efforts have been invested to develop new generations of coagulation factors with extended half-lives. Presumably, the use of long-lasting FVIII products should reduce the frequency of administration to the patients and drastically improve their quality of life. The question of their immunogenicity remains however unanswered as yet. The present review proposes a summary of the different strategies developed to enhance the half-life of FVIII, including fusion of FVIII to the Fc fragment of the human IgG1 or to human serum albumin, or attachment of polyethylene glycol. Based on the available literature, we hypothesize on the potential benefits or risks associated with each of the latter strategies in terms of immunogenicity of the newly derived hemostatic drugs. PMID:26723503

  1. Modelling the marine advance of the last Cordilleran ice sheet

    NASA Astrophysics Data System (ADS)

    Seguinot, Julien; Rogozhina, Irina

    2014-05-01

    Marine advance of the last Cordilleran ice sheet onto the north-eastern Pacific continental shelf may have caused rapid fluctuations of sea level and potentially impacted upon human migration into North America. However the position of the former ice front was critically controlled by a process that remains poorly understood: glacier calving. Geomorphological reconstructions show that part of the presently oceanic areas were ice-covered, allowing for downstream formation of the well-studied Puget and Juan de Fuca lobes. Here we use a numerical glacier model (PISM) to reconstruct the former marine front of the Cordilleran ice sheet and its impact on upstream ice dynamics. Our simulations show that the use of a thickness-based calving law leads to a strong deficit of marine ice cover in the areas where existing reconstructions suggest its advance. In contrast, a physically-based parametrization of glacier calving using the main components of the strain rate tensor (eigencalving; A. Levermann, T. Albrecht, R. Winkelmann, M. A. Martin, M. Haseloff, and I. Joughin, The Cryosphere, 6, 273-286, 2012) reproduces the geomorphologically inferred ice extent.

  2. Has adult sleep duration declined over the last 50+ years?

    PubMed

    Youngstedt, Shawn D; Goff, Eric E; Reynolds, Alexandria M; Kripke, Daniel F; Irwin, Michael R; Bootzin, Richard R; Khan, Nidha; Jean-Louis, Girardin

    2016-08-01

    The common assumption that population sleep duration has declined in the past few decades has not been supported by recent reviews, which have been limited to self-reported data. The aim of this review was to assess whether there has been a reduction in objectively recorded sleep duration over the last 50+ years. The literature was searched for studies published from 1960 to 2013, which assessed objective sleep duration (total sleep time (TST)) in healthy normal-sleeping adults. The search found 168 studies that met inclusion criteria, with 257 data points representing 6052 individuals ages 18-88 y. Data were assessed by comparing the regression lines of age vs. TST in studies conducted between 1960 and 1989 vs. 1990-2013. Weighted regression analyses assessed the association of year of study with age-adjusted TST across all data points. Regression analyses also assessed the association of year of study with TST separately for 10-y age categories (e.g., ages 18-27 y), and separately for polysomnographic and actigraphic data, and for studies involving a fixed sleep schedule and participants' customary sleep schedules. Analyses revealed no significant association of sleep duration with study year. The results are consistent with recent reviews of subjective data, which have challenged the notion of a modern epidemic of insufficient sleep. PMID:26478985

  3. Cosmic ray particles behavior during last solar minimum

    NASA Astrophysics Data System (ADS)

    Rockenbach, Marlos; Dal Lago, Alisson; Munakata, Kazuoki; Kato, Chihiro; Kuwabara, Takao; Bieber, John; Schuch, Nelson; Duldig, Marc; Humble, John; Jassar, Hala Al; Sharma, Madan; Sabbah, Ismail

    2013-04-01

    The work presents the Heliosphere characterization during the minimum solar activity. It is possible to identify phenomena caused by the Corrotating Interaction Regions - CIRs, during this solar activity phase. CIRs can be visualized in satellite data for each 27 days, approximately, and it is frequently accompanied by the Earth crossing through the Heliospheric Current Sheath - HCS. These crossing occur in a period of time lower than a day, and it is possible to study the behavior of cosmic rays particles in two different regions with opposite magnetic field polarities. The last solar minimum was special because their long duration and it was the first that the Global Muon Detector Network - GMDN operated in its full capacity. This cosmic ray detectors network is composed by muon scintillators installed in Nagoya - Japan, Hobart - Australia, São Martinho da Serra - Brazil and Kuwait City - Kuwait. Analyzing the GMDN data together with data from SOHO and/or ACE satellites it is possible to study the behavior of the cosmic ray particles and presents a Heliosphere characterization during the minimum solar activity, giving a better understanding of the cosmic ray particles modulation.

  4. Eastern Tropical Pacific Paleosalinity Reconstructions During the Last Deglaciation

    NASA Astrophysics Data System (ADS)

    Leduc, G.; Gregersen, J. A.; Sachs, J. P.

    2014-12-01

    The eastern tropical Pacific is an important climatic crossroad where the Intertropical Convergence Zone and the El Niño/Southern Oscillation drive seasonal and interannual changes in the regional rainfall patterns. Marine sediment cores indicate that the regional hydrological cycle experienced extreme changes during the last deglaciation, in close relationship with changes in the Atlantic Meridional Overturning Circulation. There is, however, no consensus yet on the timing and geographical extent of those hydrological changes, as the timing of the recorded hydrological changes vary from site to site and depend on the proxy used. We present new hydrogen isotope measurements performed on C37:2 alkenones from a marine sedimentary sequence collected in the Panama Basin, off the Costa Rican margin. While an increase in δD of about 10 ‰ is recorded at the end of the Heinrich event 1, there is no significant change in δD during the Younger Dryas. A comparison of those data with seawater oxygen isotopic signatures estimated from the same core reveals differences in the way atmospheric circulation is captured by those two proxies. A comparison with alkenone hydrogen isotope measurements performed on a core located along the Columbian Margin demonstrates regional contrasts in the sensitivity of the hydrological cycle during te deglaciation. We will tentatively use jointly these results to build up a climatic scenario capable of explaining those contrasting modes of millenial-scale variability.

  5. Human population dynamics in Europe over the Last Glacial Maximum

    PubMed Central

    Tallavaara, Miikka; Luoto, Miska; Korhonen, Natalia; Järvinen, Heikki; Seppä, Heikki

    2015-01-01

    The severe cooling and the expansion of the ice sheets during the Last Glacial Maximum (LGM), 27,000–19,000 y ago (27–19 ky ago) had a major impact on plant and animal populations, including humans. Changes in human population size and range have affected our genetic evolution, and recent modeling efforts have reaffirmed the importance of population dynamics in cultural and linguistic evolution, as well. However, in the absence of historical records, estimating past population levels has remained difficult. Here we show that it is possible to model spatially explicit human population dynamics from the pre-LGM at 30 ky ago through the LGM to the Late Glacial in Europe by using climate envelope modeling tools and modern ethnographic datasets to construct a population calibration model. The simulated range and size of the human population correspond significantly with spatiotemporal patterns in the archaeological data, suggesting that climate was a major driver of population dynamics 30–13 ky ago. The simulated population size declined from about 330,000 people at 30 ky ago to a minimum of 130,000 people at 23 ky ago. The Late Glacial population growth was fastest during Greenland interstadial 1, and by 13 ky ago, there were almost 410,000 people in Europe. Even during the coldest part of the LGM, the climatically suitable area for human habitation remained unfragmented and covered 36% of Europe. PMID:26100880

  6. Integrative oncology: the last ten years--a personal retrospectve.

    PubMed

    Boyd, D Barry

    2007-01-01

    In the last decade, there has been dramatic changes in all areas of integrative patient care. None has been more dramatic than those in the field of cancer care, which has gone from alternative and complementary treatments delivered outside the conventional setting to the integration of many of these approaches into the care of the cancer patient. In many cases, these changes have been driven by patient demand and supported by private funding and out-of-pocket payments by patients themselves. Virtually all major medical centers have departments devoted to integrative patient care--whether true stand-alone centers or departments with a research interest in this area. This is particularly true of the major cancer centers, many of which-including Memorial Sloan Kettering Cancer Center, New York; M.D. Anderson Cancer Center, Houston, Tex; Johns Hopkins University, Baltimore, Md; Duke University, Durham, NC; and the Dana Farber Cancer Institute, Boston, Mass--have developed integrative cancer programs. In addition, programs such as the Cancer Treatment Centers of America have inpatient and outpatient programs with teams of practitioners, including medical oncologists, surgeons, and radiation therapists, as well as credentialed naturopathic doctors, nutritionists, mind-body specialists and other integrative practitioners. Despite the increased interest in developing integrative approaches to cancer, many medical oncologists remain skeptical about the value of these modalities. PMID:17283742

  7. The Last Glacial Maximum experiment in PMIP4-CMIP6

    NASA Astrophysics Data System (ADS)

    Kageyama, Masa; Braconnot, Pascale; Abe-Ouchi, Ayako; Harrison, Sandy; Lambert, Fabrice; Peltier, W. Richard; Tarasov, Lev

    2016-04-01

    The Last Glacial Maximum (LGM), around 21,000 years ago, is a cold climate extreme. As such, it has been the focus of many studies on modelling and climate reconstruction, which have brought knowledge on the mechanisms explaining this climate, in terms of climate on the continents and of the ocean state, and in terms relationships between climate changes over land, ice sheets and oceans. It is still a challenge for climate or Earth System models to represent the amplitude of climate changes for this period, under the following forcings: - Ice sheets, which represent perturbations in land surface type, altitude and land/ocean distribution - Atmospheric composition - Astronomical parameters Feedbacks from the vegetation and dust are also known to have played a role in setting up the LGM climate but have not been accounted for in previous PMIP experiments. In this poster, we will present the experimental set-up of the PMIP4 LGM experiment, which is presently being discussed and will be finalized for March 2016. For more information and discussion of the PMIP4-CMIP6 experimental design, please visit: https://wiki.lsce.ipsl.fr/pmip3/doku.php/pmip3:cmip6:design:index

  8. Human population dynamics in Europe over the Last Glacial Maximum.

    PubMed

    Tallavaara, Miikka; Luoto, Miska; Korhonen, Natalia; Järvinen, Heikki; Seppä, Heikki

    2015-07-01

    The severe cooling and the expansion of the ice sheets during the Last Glacial Maximum (LGM), 27,000-19,000 y ago (27-19 ky ago) had a major impact on plant and animal populations, including humans. Changes in human population size and range have affected our genetic evolution, and recent modeling efforts have reaffirmed the importance of population dynamics in cultural and linguistic evolution, as well. However, in the absence of historical records, estimating past population levels has remained difficult. Here we show that it is possible to model spatially explicit human population dynamics from the pre-LGM at 30 ky ago through the LGM to the Late Glacial in Europe by using climate envelope modeling tools and modern ethnographic datasets to construct a population calibration model. The simulated range and size of the human population correspond significantly with spatiotemporal patterns in the archaeological data, suggesting that climate was a major driver of population dynamics 30-13 ky ago. The simulated population size declined from about 330,000 people at 30 ky ago to a minimum of 130,000 people at 23 ky ago. The Late Glacial population growth was fastest during Greenland interstadial 1, and by 13 ky ago, there were almost 410,000 people in Europe. Even during the coldest part of the LGM, the climatically suitable area for human habitation remained unfragmented and covered 36% of Europe. PMID:26100880

  9. About ozone depletion in stratosphere over Brazil in last decade

    NASA Astrophysics Data System (ADS)

    Martin, Inácio M.; Imai, Takeshi; Seguchi, Tomio

    The depletion of stratospheric ozone, resulting from the emission of chlorofluorocarbons (CFCs), has become a major issue since 1980. The decrease in stratospheric ozone over the polar regions has been pronounced at the South Pole than at the North Pole. In mid-latitude and equatorial regions, ozone depletion becomes less important; it depends on seasonal effects and on the characteristics of a particular region. The detailed mechanism by which the polar ozone holes form is different from that for the mid-latitude thinning, but the most important process in both trends is the catalytic destruction of ozone by atomic chlorine and bromine. The main source of these halogen atoms in the stratosphere is photodissociation of CFC compounds, commonly called freons, and of bromofluorocarbon compounds known as halons. These compounds are transported into the stratosphere after being emitted at the surface. Both ozone depletion mechanisms strengthened as emissions of CFCs and halons increased [1]. Measurements of stratospheric ozone carried out on several locations in Brazil and on the South Pole in the last decade (1996-2005), using detectors placed on ground, stratospheric balloons and Earth Probe TOMS satellites, are presented here. Detailed series analysis from 1980 up to the present describes a mean ozone depletion of 4[1] http://en.wikipedia.org/wiki/Ozone/depletion.

  10. Diagnosis of visceral leishmaniasis: developments over the last decade.

    PubMed

    Srividya, Gurumurthy; Kulshrestha, Arpita; Singh, Ruchi; Salotra, Poonam

    2012-03-01

    Diagnostic parameters for visceral leishmaniasis (VL), a potentially fatal parasitic disease caused by Leishmania donovani, have been redefined in the last decade with the development of serological and molecular tests, though a definitive diagnosis still banks on the century-old parasitological methods in many areas. Recombinant antigens have improved performance of serodiagnostic methods. Serology-based tests, rk39 antigen dipstick, and direct agglutination test commonly employed in the field are highly sensitive methods, however, fail to distinguish past infections. Molecular approaches have become increasingly relevant due to remarkable sensitivity, specificity, and flexibility in choice of samples. Quantitative polymerase chain reaction is a highly sensitive and specific tool used in referral labs for detection/assessment of parasite load in VL patients and subsequently in monitoring treatment response to antileishmanial agents. The method displays potential to provide threshold for distinguishing asymptomatics in endemic areas. Currently, improvement in VL diagnostics is required for successful decentralized (point-of-care) testing in field conditions and to detect VL-HIV co-infection. Techniques such as loop-mediated isothermal amplification offer a reliable molecular diagnostic method for field application. The diagnosis based on bioanalytics/biosensors promise frontiers for point-of-care VL detection after adequate standardization. This review summarizes the recent developments in VL diagnostics, drawing attention towards the need for standardization of the diagnostics across the affected regions. PMID:22065060

  11. Dermal sensitization potential of ja-2 solid propellant in guinea pigs. Report for 4 April-9 May 1986

    SciTech Connect

    Lewis, C.M.; Brown, L.D.; Korte, D.W.

    1989-11-01

    JA-2 Solid Propellant was evaluated for its potential to produce dermal sensitization in male guinea pigs. The Buehler test, which utilizes repeated closed patch inductions with the test compound, was used for this evaluation. No evidence that JA-2 Solid Propellant induced sensitization was obtained in the study.

  12. The relative importance of methane sources and sinks over the Last Interglacial period and into the last glaciation

    NASA Astrophysics Data System (ADS)

    Quiquet, A.; Archibald, A. T.; Friend, A. D.; Chappellaz, J.; Levine, J. G.; Stone, E. J.; Telford, P. J.; Pyle, J. A.

    2015-03-01

    All recent climatic projections for the next century suggest that we are heading towards a warmer climate than today (Intergovernmental Panel on Climate Change; Fifth Assessment Report), driven by increasing atmospheric burdens of anthropogenic greenhouse gases. In particular, the volume mixing ratio of methane, the second-most important anthropogenic greenhouse gas, has increased by a factor of ˜2.5 from the beginning of the European Industrial Revolution. Due to their complex responses to climatic factors, understanding of the dynamics of future global methane emissions and sinks is crucial for the next generation of climate projections. Of relevance to this problem, the Earth likely experienced warmer average temperatures than today during the Last Interglacial (LIG) period (130-115 kaBP). Interestingly, ice cores do not indicate a different methane mixing ratio from the Pre-Industrial Holocene (PIH), in other words the current interglacial period prior to anthropogenic influence. This is surprising as warmer temperatures might be expected to increase methane emissions. The present study aims to improve our understanding of the changes in the global methane budget through quantifying the relative importance of sources and sinks of methane during the last full glacial-interglacial cycle. A fairly limited number of studies have investigated this cycle at the millenium time scale with most of them examining the doubling in CH4 from the Last Glacial Maximum (LGM) to the PIH. Though it is still a matter of debate, a general consensus suggests a predominant role to the change in methane emissions from wetlands and only a limited change in the oxidising capacity of the atmosphere. In the present study we provide an estimate of the relative importance of sources and sinks during the LIG period, using a complex climate-chemistry model to quantify the sinks, and a methane emissions model included in a global land surface model, for the sources. We are not aware of any

  13. Insect-Based Holocene (and Last Interglacial?) Paleothermometry from the E and NW Greenland Ice Sheet Margins: A Fly's-Eye View of Warmth on Greenland

    NASA Astrophysics Data System (ADS)

    Axford, Y.; Bigl, M.; Carrio, C.; Corbett, L. B.; Francis, D. R.; Hall, B. L.; Kelly, M. A.; Levy, L.; Lowell, T. V.; Osterberg, E. C.; Richter, N.; Roy, E.; Schellinger, G. C.

    2011-12-01

    records therefore provide opportunities to compare climate inferences based upon ice core data and reconstructed ice margin histories with independent, biologically based estimates of air temperatures for the Holocene and possibly the Last Interglacial. Briner, J.P., Axford, Y., Forman, S.L., Miller, G.H., and Wolfe, A.P. 2007. Multiple generations of interglacial lake sediment preserved beneath the Laurentide Ice Sheet. Geology 35, 887-890. Levy, L.B., Kelly, M.A., Lowell, T.V., Hall, B.L., Hempel, L.A., Honsaker, W.M., Lusas, A.R., Howley, J.A., Axford, Y.L., 2013. Holocene fluctuations of Bregne ice cap, Scoresby Sund, east Greenland: a proxy for climate along the Greenland Ice Sheet margin. In press, Quaternary Science Reviews.

  14. Insect-Based Holocene (and Last Interglacial?) Paleothermometry from the E and NW Greenland Ice Sheet Margins: A Fly's-Eye View of Warmth on Greenland

    NASA Astrophysics Data System (ADS)

    Axford, Y.; Bigl, M.; Carrio, C.; Corbett, L. B.; Francis, D. R.; Hall, B. L.; Kelly, M. A.; Levy, L.; Lowell, T. V.; Osterberg, E. C.; Richter, N.; Roy, E.; Schellinger, G. C.

    2013-12-01

    records therefore provide opportunities to compare climate inferences based upon ice core data and reconstructed ice margin histories with independent, biologically based estimates of air temperatures for the Holocene and possibly the Last Interglacial. Briner, J.P., Axford, Y., Forman, S.L., Miller, G.H., and Wolfe, A.P. 2007. Multiple generations of interglacial lake sediment preserved beneath the Laurentide Ice Sheet. Geology 35, 887-890. Levy, L.B., Kelly, M.A., Lowell, T.V., Hall, B.L., Hempel, L.A., Honsaker, W.M., Lusas, A.R., Howley, J.A., Axford, Y.L., 2013. Holocene fluctuations of Bregne ice cap, Scoresby Sund, east Greenland: a proxy for climate along the Greenland Ice Sheet margin. In press, Quaternary Science Reviews.

  15. Heavy Ion Collisions at the LHC - Last Call for Predictions

    SciTech Connect

    Armesto, N; Borghini, N; Jeon, S; Wiedemann, U A; Abreu, S; Akkelin, V; Alam, J; Albacete, J L; Andronic, A; Antonuv, D; Arleo, F; Armesto, N; Arsene, I C; Barnafoldi, G G; Barrette, J; Bauchle, B; Becattini, F; Betz, B; Bleicher, M; Bluhm, M; Boer, D; Bopp, F W; Braun-Munzinger, P; Bravina, L; Busza, W; Cacciari, M; Capella, A; Casalderrey-Solana, J; Chatterjee, R; Chen, L; Cleymans, J; Cole, B A; delValle, Z C; Csernai, L P; Cunqueiro, L; Dainese, A; de Deus, J D; Ding, H; Djordjevic, M; Drescher, H; Dremin, I M; Dumitru, A; El, A; Engel, R; d'Enterria, D; Eskola, K J; Fai, G; Ferreiro, E G; Fries, R J; Frodermann, E; Fujii, H; Gale, C; Gelis, F; Goncalves, V P; Greco, V; Gyulassy, M; van Hees, H; Heinz, U; Honkanen, H; Horowitz, W A; Iancu, E; Ingelman, G; Jalilian-Marian, J; Jeon, S; Kaidalov, A B; Kampfer, B; Kang, Z; Karpenko, I A; Kestin, G; Kharzeev, D; Ko, C M; Koch, B; Kopeliovich, B; Kozlov, M; Kraus, I; Kuznetsova, I; Lee, S H; Lednicky, R; Letessier, J; Levin, E; Li, B; Lin, Z; Liu, H; Liu, W; Loizides, C; Lokhtin, I P; Machado, M T; Malinina, L V; Managadze, A M; Mangano, M L; Mannarelli, M; Manuel, C; Martinez, G; Milhano, J G; Mocsy, A; Molnar, D; Nardi, M; Nayak, J K; Niemi, H; Oeschler, H; Ollitrault, J; Paic, G; Pajares, C; Pantuev, V S; Papp, G; Peressounko, D; Petreczky, P; Petrushanko, S V; Piccinini, F; Pierog, T; Pirner, H J; Porteboeuf, S; Potashnikova, I; Qin, G Y; Qiu, J; Rafelski, J; Rajagopal, K; Ranft, J; Rapp, R; Rasanen, S S; Rathsman, J; Rau, P; Redlich, K; Renk, T; Rezaeian, A H; Rischke, D; Roesler, S; Ruppert, J; Ruuskanen, P V; Salgado, C A; Sapeta, S; Sarcevic, I; Sarkar, S; Sarycheva, L I; Schmidt, I; Shoski, A I; Sinha, B; Sinyukov, Y M; Snigirev, A M; Srivastava, D K; Stachel, J; Stasto, A; Stocker, H; Teplov, C Y; Thews, R L; Torrieri, G; Pop, V T; Triantafyllopoulos, D N; Tuchin, K L; Turbide, S; Tywoniuk, K; Utermann, A; Venugopalan, R; Vitev, I; Vogt, R; Wang, E; Wang, X N; Werner, K; Wessels, E; Wheaton, S; Wicks, S; Wiedemann, U A; Wolschin, G; Xiao, B; Xu, Z; Yasui, S; Zabrodin, E; Zapp, K; Zhang, B

    2008-02-25

    In August 2006, the CERN Theory Unit announced to restructure its visitor program and to create a 'CERN Theory Institute', where 1-3 month long specific programs can take place. The first such Institute was held from 14 May to 10 June 2007, focusing on 'Heavy Ion Collisions at the LHC - Last Call for Predictions'. It brought together close to 100 scientists working on the theory of ultra-relativistic heavy ion collisions. The aim of this workshop was to review and document the status of expectations and predictions for the heavy ion program at the Large Hadron Collider LHC before its start. LHC will explore heavy ion collisions at {approx} 30 times higher center of mass energy than explored previously at the Relativistic Heavy Ion Collider RHIC. So, on the one hand, the charge of this workshop provided a natural forum for the exchange of the most recent ideas, and allowed to monitor how the understanding of heavy ion collisions has evolved in recent years with the data from RHIC, and with the preparation of the LHC experimental program. On the other hand, the workshop aimed at a documentation which helps to distinguish pre- from post-dictions. An analogous documentation of the 'Last Call for Predictions' [1] was prepared prior to the start of the heavy-ion program at the Relativistic Heavy Ion Collider RHIC, and it proved useful in the subsequent discussion and interpretation of RHIC data. The present write-up is the documentation of predictions for the LHC heavy ion program, received or presented during the CERN TH Institute. The set-up of the CERN TH Institute allowed us to aim for the wide-most coverage of predictions. There were more than 100 presentations and discussions during the workshop. Moreover, those unable to attend could still participate by submitting predictions in written form during the workshop. This followed the spirit that everybody interested in making a prediction had the right to be heard. To arrive at a concise document, we required that

  16. Variations in the methane budget over the last two millennia

    NASA Astrophysics Data System (ADS)

    Sapart, C. J.

    2012-06-01

    Methane (CH4) is a strong greenhouse gas and even though its atmospheric abundance is lower than carbon dioxide (CO2), CH4 has a global warming potential twenty-five times larger than CO2 and its atmospheric abundance has drastically increased since 1800. Understanding the evolution of the CH4 atmospheric abundance is complex, because it is controlled by multiple sources (e.g. wetlands, biomass burning, ruminants, rice paddies and fossil fuel) and sinks, and large uncertainties exist on how sensitive those sources and sinks are to climate variability. The aim of this research is to understand the influence of climate variability and anthropogenic activity on the CH4 budget, i.e. the balance between the different sources and sinks, during the last two millennia. For this purpose a technique was developed to analyze the CH4 isotopic composition of air in ice cores. Analysis of the isotopic composition of CH4 preserved in ice cores provides evidence for the environmental drivers of variations in CH4 mixing ratios, because different sources and sinks affect the isotopic composition of CH4 uniquely. Our main results from air trapped in Greenland ice cores shows that the carbon isotopic composition (d13C) of CH4 underwent pronounced centennial-scale variations between 200 BC and 1600 AD without clear corresponding changes in CH4 mixing ratios. Two-box model calculations suggest that those centennial-scale variations in isotope ratios are due to changes in biomass burning and biogenic sources (e.g. wetlands, agriculture), which are correlated with both natural climate variability, including the Medieval Climate Anomaly and with changes in human population, land-use and important events in history as the expansion of the Roman Empire, the fall of the Han dynasty and the Medieval period. This shows that human activity had an impact on the methane budget already two thousand years ago and is likely responsible for the atmospheric methane increase in the atmosphere during

  17. Downscaling GCM-simulated precipitation for the last millennium

    NASA Astrophysics Data System (ADS)

    Eden, Jonathan; Widmann, Martin; Smith, Richard

    2014-05-01

    Climate variability in the pre-instrumental period can be estimated either from climate proxy data or from numerical simulations. Both approaches still have considerable uncertainties and consistency tests are crucial for identifying robust features. One of the problems when comparing simulations with proxy-based reconstructions are potential scale mismatches. If the proxy-based reconstructions represent regional climate a direct comparison with simulated variables from global climate models, which in palaeoclimate applications are run with coarse resolutions, can lead to misleading results for two reasons: (i) the climate model might be biased even on large spatial scales, and (ii) small-scale spatial variability cannot be represented by the climate model. This problem can be expected to be particularly relevant for precipitation because of its high spatial variability. One way of addressing this problem is by applying downscaling techniques to the simulations. We have applied a statistical downscaling and correction method to precipitation from a simulation for the last millennium with the MPI for Meteorology Earth System Model, which uses ECHAM5-T31 as the atmosphere component. Our downscaling method, which is based on model output statistics (MOS), has been shown to outperform more standard (so-called perfect-prog) statistical downscaling methods when applied to simulated precipitation from the second half of the twentieth century, but it has not yet been applied to palaeoclimate simulations. Our aim is two-fold: to assess (a) whether downscaling using MOS yields additional information about long-term changes in regional climate and (b) to what extent the downscaled simulations may be in greater agreement with proxy-based reconstructions than raw model output. Two MOS downscaling methods, based on local scaling and principal component regression, are calibrated 'event-wise' (i.e. between contemporaneous sequences of simulated and observed events) using

  18. The unstable geomagnetic field during the last glacial

    NASA Astrophysics Data System (ADS)

    Nowaczyk, Norbert; Frank, Ute; Kind, Jessica; Plessen, Birgit; Arz, Helge

    2013-04-01

    Detailed stratigraphic analyses of a sediment composite record from three different sites in the southeastern Black Sea yielded a high-resolution, well-dated paleomagnetic record of the past 14 to 68 ka. Age constraints are provided by 16 AMS 14C ages, identification of the Campanian Ignimbrite tephra (39.28±0.11 ka), and by detailed tuning of sedimentologic parameters of the Black Sea sediments to the oxygen isotope record from the Greenland NGRIP ice core. Dansgaard-Oeschger events 3 through 18 are very well expressed in the Black Sea sedimentary records of Ca-content, oxygen isotopes as well as in records of ice-rafted detritus. Though hampered by some larger hiatusses at one site, and patchy contaminations by diagenetically formed greigite, the paleomagnetic composite record obtained from the preserved primary detrital magnetite phase reflects a highly dynamic geomagnetic field during the last glacial period. Relative variations of paleointensity inferred from the sediments' magnetisations were converted into a record of the virtual axial dipole moment (VADM). Thus, the Black Sea paleomagnetic record comprises evidence for the Norwegian-Greenland-Sea excursion at 64.5 ka (VADM = 1.5×1022 Am2), a full reversal of the geomagnetic field during the Laschamp excursion at 41 ka and several subsequent excursions with low northern virtual geomagnetic pole (VGP) latitudes, including the Mono Lake excursion at 34.5 ka (VADM = 3.0×1022 Am2). According to the derived age model, VGP positions during the Laschamp excursion persisted at high southern latitudes in Antarctica for an estimated 440 years, making the Laschamp excursion a short-lived event with fully reversed polarity directions. Recorded field reversals of the Laschamp excursion, lasting only an estimated ~250 years, are characterized by very low paleointensities with VADMs as low as 0.50×1022 Am2. The reversed phase of the Laschamp excursion is associated with a significant field recovery with a VADM of 2.0

  19. Long-lasting virtual motorcycle-riding trainer effectiveness

    PubMed Central

    Vidotto, Giulio; Tagliabue, Mariaelena; Tira, Michael D.

    2015-01-01

    This work aimed to test the long-lasting effects of learning acquired with a virtual motorcycle-riding trainer as a tool to improve hazard perception. During the simulation, the rider can interact with other road actors and experience the most common potential accident situations in order to learn to modify his or her behavior to anticipate hazards and avoid crashes. We compared performance to the riding simulator of the two groups of participants: the experimental group, which was trained with the same simulator one year prior, and the control group that had not received any type of training with a riding or driving simulator. All of the participants had ridden a moped in the previous 12 months. The experimental group showed greater abilities to avoid accidents and recognize hazards in comparison to their performance observed a year before, whereas the performance of the control group was similar to that of the experimental group 1 year before in the first two sessions, and even better in the third. We interpreted this latter result as a consequence of their prior on-road experience. Also, the fact that the performance of the experimental group at the beginning of the follow-up is better than that recorded at the end of the training—1 year before—is in line with the idea of a transfer from the on-road experience to the simulator. The present data confirm our main expectation that the effectiveness of the riding training simulator on the ability to cope with potentially dangerous situations persists over time and provides additional evidence in favor of the idea that simulators may be considered useful tools for training the ability to detect and react to hazards, leading to an improvement of this higher-order cognitive skill that persists over time. Implications for the reciprocal influence of the training with the simulator and the on-the road experience are discussed as well. PMID:26579036

  20. A long-lasting wireless stimulator for small mammals

    PubMed Central

    Hentall, Ian D.

    2013-01-01

    The chronic effects of electrical stimulation in unrestrained awake rodents are best studied with a wireless neural stimulator that can operate unsupervised for several weeks or more. A robust, inexpensive, easily built, cranially implantable stimulator was developed to explore the restorative effects of brainstem stimulation after neurotrauma. Its connectorless electrodes directly protrude from a cuboid epoxy capsule containing all circuitry and power sources. This physical arrangement prevents fluid leaks or wire breakage and also simplifies and speeds implantation. Constant-current pulses of high compliance (34 volts) are delivered from a step-up voltage regulator under microprocessor control. A slowly pulsed magnetic field controls activation state and stimulation parameters. Program status is signaled to a remote reader by interval-modulated infrared pulses. Capsule size is limited by the two batteries. Silver oxide batteries rated at 8 mA-h were used routinely in 8 mm wide, 15 mm long and 4 mm high capsules. Devices of smaller contact area (5 by 12 mm) but taller (6 mm) were created for mice. Microstimulation of the rat's raphe nuclei with intermittent 5-min (50% duty cycle) trains of 30 μA, 1 ms pulses at 8 or 24 Hz frequency during 12 daylight hours lasted 21.1 days ±0.8 (mean ± standard error, Kaplan-Meir censored estimate, n = 128). Extended lifetimes (>6 weeks, no failures, n = 16) were achieved with larger batteries (44 mA-h) in longer (18 mm), taller (6 mm) capsules. The circuit and electrode design are versatile; simple modifications allowed durable constant-voltage stimulation of the rat's sciatic nerve through a cylindrical cathode from a subcutaneous pelvic capsule. Devices with these general features can address in small mammals many of the biological and technical questions arising neurosurgically with prolonged peripheral or deep brain stimulation. PMID:24130527

  1. Perennial plate tectonics with lasting mantle lithosphere scars

    NASA Astrophysics Data System (ADS)

    Heron, P.; Pysklywec, R. N.; Stephenson, R.

    2015-12-01

    Although the conventional theory of plate tectonics can explain non-rigid behaviour at plate boundaries, it cannot adequately explain the processes involved in deformation and seismicity within plate interiors. Here, we consider that the pre-existing deformation or "scarring" within the mantle lithosphere may have a very long lived presence that could incorporate deformation of the plate interior and plate boundary. Mantle lithosphere scars from continent-continent collisions could generate virtual plate boundaries that remain over long timescales, producing "perennial" plate tectonics. Local geophysical studies can map the crustal environment well, and global whole mantle tomography models are rapidly improving, yet high-resolution images of the mantle lithosphere are often not available in regions where scarring may be present. Where mantle lithosphere heterogeneities have been observed (usually interpreted simply as subduction scars), the same attention has not been afforded to them as, for example, re-activation of faults within the Earth's crust. In idealized numerical simulations, we compare how relic scarring at varying depths in the lithosphere affects patterns of deformation. High-resolution thermal-mechanical numerical experiments explore continental lithospheric deformation featuring a weakened crust and mantle lithosphere scars. Our models show that deep lithospheric scars can control the tectonic evolution of a region over shallow geological features, indicating the importance of mantle lithosphere heterogeneities. The Altyn Tagh Fault (ATF) in central China is an example of an ancient continental collision zone that undergoes periodic deformation during times of regional compression. We suggest that the ATF may be a locale where a long-lasting mantle lithosphere scar can control the subsequent crustal evolution and deformation, with ancient plate boundaries having a "perennial" plate tectonic presence.

  2. Tropical Cyclones in Simulations of the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Zamora, R. A.; Korty, R. L.; Camargo, S. J.

    2015-12-01

    How tropical cyclones respond to large-scale changes in climate is an important and complex question. Here we study the question using the response to the climate forcing of the Last Glacial Maximum (LGM). Utilizing two detecting and tracking algorithms of tropical cyclones (TC), we assess the sensitivity of the genesis and frequency of TCs in a 1° x 1° simulation of a global climate model (CCSM), a limited-area simulation (western north Pacific; WNP) of the higher resolution WRF model (36 km horizontal resolution), and the statistical downscaling approach developed by Emanuel. We assess how changes between the LGM and 20th century climatology of TCs are related to changes in the large-scale environmental variables known to be important to TCs (e.g. vorticity, wind shear, and available moisture). Several facets of the TC climatology at the LGM are similar across all three modeling techniques: regions that spawn TCs and their seasonal cycle at the LGM is similar to the present-day distribution, while the total counts are slightly reduced at the LGM. The average intensity in the WRF model (which features resolution high enough to resolve strong storms) is similar between the two climates, though the distribution of intensity is more concentrated at the LGM (there are fewer weak events and fewer of the strongest events at the LGM). Conditions are similarly favorable in much of the deep tropics at the LGM compared to the 20th century, particularly in the central and western Pacific, but conditions become more hostile at the subtropical margins. We compare the resulting climatology with the underlying changes in environmental factors, and empirically derive a genesis index to identify the best fit between changes in the factors and climatology of events.

  3. An Atlantic-Pacific ventilation seesaw across the last deglaciation

    NASA Astrophysics Data System (ADS)

    Freeman, E.; Skinner, L. C.; Tisserand, A.; Dokken, T.; Timmermann, A.; Menviel, L.; Friedrich, T.

    2015-08-01

    It has been proposed that the rapid rise of atmospheric CO2 across the last deglaciation was driven by the release of carbon from an extremely radiocarbon-depleted abyssal ocean reservoir that was 'vented' to the atmosphere primarily via the deep- and intermediate overturning loops in the Southern Ocean. While some radiocarbon observations from the intermediate ocean appear to confirm this hypothesis, others appear to refute it. Here we use radiocarbon measurements in paired benthic- and planktonic foraminifera to reconstruct the benthic-planktonic 14C age offset (i.e. 'ventilation age') of intermediate waters in the western equatorial Atlantic. Our results show clear increases in local radiocarbon-based ventilation ages during Heinrich-Stadial 1 (HS1) and the Younger Dryas (YD). These are found to coincide with opposite changes of similar magnitude observed in the Pacific, demonstrating a 'seesaw' in the ventilation of the intermediate Atlantic and Pacific Oceans that numerical model simulations of North Atlantic overturning collapse indicate was primarily driven by North Pacific overturning. We propose that this Atlantic-Pacific ventilation seesaw would have combined with a previously identified North Atlantic-Southern Ocean ventilation seesaw to enhance ocean-atmosphere CO2 exchange during a 'collapse' of the North Atlantic deep overturning limb. Whereas previous work has emphasized a more passive role for intermediate waters in deglacial climate change (merely conveying changes originating in the Southern Ocean) we suggest instead that the intermediate water seesaw played a more active role via relatively subtle but globally coordinated changes in ocean dynamics that may have further influenced ocean-atmosphere carbon exchange.

  4. Long-lasting bradypnea induced by repeated social defeat.

    PubMed

    Brouillard, Charly; Carrive, Pascal; Camus, Françoise; Bénoliel, Jean-Jacques; Similowski, Thomas; Sévoz-Couche, Caroline

    2016-08-01

    Repeated social defeat in the rat induces long-lasting cardiovascular changes associated with anxiety. In this study, we investigated the effects of repeated social defeat on breathing. Respiratory rate was extracted from the respiratory sinus arrhythmia (RSA) peak frequency of the ECG in rats subjected to social defeat for 4 consecutive days. Respiratory rate was recorded under anesthesia 6 days (D+10) or 26 days (D+30) after social defeat. At D+10, defeated (D) rats spent less time in the open arms of the elevated plus maze test, had heavier adrenal glands, and displayed bradypnea, unlike nondefeated animals. At D+30, all signs of anxiety had disappeared. However, one-half of the rats still displayed bradypnea (DL rats, for low respiratory rate indicated by a lower RSA frequency), whereas those with higher respiratory rate (DH rats) had recovered. Acute blockade of the dorsomedial hypothalamus (DMH) or nucleus tractus solitarii (NTS) 5-HT3 receptors reversed bradypnea in all D rats at D+10 and in DL rats at D+30. Respiratory rate was also recorded in conscious animals implanted with radiotelemetric ECG probes. DH rats recovered between D+10 and D+18, whereas DL rats remained bradypneic until D+30. In conclusion, social stress induces sustained chronic bradypnea mediated by DMH neurons and NTS 5-HT3 receptors. These changes are associated with an anxiety-like state that persists until D+10, followed by recovery. However, bradypnea may persist in one-half of the population up until D+30, despite apparent recovery of the anxiety-like state. PMID:27225946

  5. "Last mile" challenges to in situ volcanic data transmission

    NASA Astrophysics Data System (ADS)

    Fonseca, J. F. B. D.; Faria, B. V. E.; Trindade, J.; Cruz, G.; Chambel, A.; Silva, F. M.; Pereira, R. L.; Vazão, T.

    2013-08-01

    Scientists play a key role in volcanic risk mitigation, but rely heavily on fast access to data acquired in the vicinity of an active volcano. Hazardous volcanoes are often located in remote areas were telecommunications infrastructure is fragile. Besides being exposed directly to the volcanic hazard, the infrastructure in such remote areas can suffer also from "last mile" limitations derived from lack of market demand for data transmission services. In this paper, we report on the findings of FP7 MIAVITA project in the topic of volcanic data transmission. We draw on the contribution of partners from emergent or developing countries to identify the main bottlenecks and fragilities. We present also the results of an experiment conducted in Fogo island, Cape Verde, to test the availability of VSAT services adequate for volcanic monitoring. We warn against the false sense of security resulting from increasingly ubiquitous connectivity, and point out the lack of reliability of many consumer-type services, particularly during emergencies when such services are likely to crash due to excess of demand from the public. Finally, we propose guidelines and recommend best practices for the design of volcanic monitoring networks in what concerns data transmission. In particular, we advise that the data transmission equipment close to the exposed area should be owned, operated and maintained by the volcanic monitoring institution. We exemplify with the setup of the Fogo telemetric interface, which uses low-power licence-free radio modems to reach a robust point of entry into the public network at a suitable distance from the volcano.

  6. "Last mile" challenges to in situ volcanic data transmission

    NASA Astrophysics Data System (ADS)

    Fonseca, J. F. B. D.; Faria, B. V. E.; Trindade, J.; Cruz, G.; Chambel, A.; Silva, F. M.; Pereira, R. L.; Vazão, T.

    2013-12-01

    Scientists play a key role in volcanic risk management, but rely heavily on fast access to data acquired in the vicinity of an active volcano. Hazardous volcanoes are often located in remote areas were telecommunications infrastructure is fragile. Besides being exposed directly to the volcanic hazard, the infrastructure in such remote areas can also suffer from "last mile" limitations derived from lack of market demand for data transmission services. In this paper, we report on the findings of the FP7 MIAVITA project in the topic of volcanic data transmission. We draw on the contribution of partners from emergent or developing countries to identify the main bottlenecks and fragilities. We also present the results of an experiment conducted on Fogo Island, Cape Verde, to test the availability of VSAT services adequate for volcanic monitoring. We warn against the false sense of security resulting from increasingly ubiquitous connectivity, and point out the lack of reliability of many consumer-type services, particularly during emergencies when such services are likely to crash due to excess of demand from the public. Finally, we propose guidelines and recommend best practices for the design of volcanic monitoring networks in what concerns data transmission. In particular, we advise that the data transmission equipment close to the exposed area should be owned, operated and maintained by the volcanic monitoring institution. We exemplify with the set-up of the Fogo telemetric interface, which uses low-power licence-free radio modems to reach a robust point of entry into the public network at a suitable distance from the volcano.

  7. Syphilis hospitalisations in Portugal over the last decade.

    PubMed

    Sousa-Pinto, B; Freitas, A; Lisboa, C

    2016-02-01

    Although several studies have reported an increase of syphilis incidence over the last decade in Western Europe, information concerning syphilis epidemiology in Portugal remains scarce. Therefore, we sought to characterise acquired syphilis-associated hospitalisations in Portugal according to demographic and clinical data. We used a database containing all hospitalisations that occurred in mainland Portugal public hospitals with discharges between 2000 and 2014. We analysed all hospitalisations associated with ICD-9-CM codes 091-097.x (corresponding to acquired syphilis diagnosis) concerning inpatients' gender, age and comorbidities. The median length of stay and in-hospital mortality rates were also studied. Between 2000 and 2014, there were a total of 8974 syphilis-related hospitalisations in mainland Portugal. The rate of acquired syphilis hospitalisations per 100,000 inhabitants increased by 33 % during the studied period. Syphilis hospitalisation rates increased by 70 % in males and 139 % among patients aged over 55 years. On the other hand, they declined by 10 % in females and 20 % among patients younger than 55 years old. The percentage of syphilis episodes presenting cardiovascular and neuropsychiatric comorbidities increased, while the percentage of syphilis episodes presenting HIV co-infection decreased by 69 %. A fatal outcome was reported in 5 % of episodes; 4.6 % of them had acquired syphilis as the main reason for hospitalisation. This study illustrates that, despite being a preventable infection, syphilis remains a public health problem. The analysis of hospitalisation and administrative data helps to understand syphilis epidemiology and provides a supplement to traditional case notifications. PMID:26581424

  8. Epidemiology of periodontal diseases in Indian population since last decade

    PubMed Central

    Chandra, Anuja; Yadav, Om Prakash; Narula, Sugandha; Dutta, Angel

    2016-01-01

    Objective: India suffers lot of disparities in terms of oral health care and 95% of the Indian population suffers from periodontal disease. The aim of this review is to estimate the risk factors responsible for periodontal diseases as well as prevalence for the same in the last decade to make an attempt to develop a strategy to improve formulation of an effective oral health care policy in India. Materials and Methods: Keywords such as “prevalence of periodontal diseases,” “epidemiology,” “periodontitis in India,” and “oral hygiene status in India” were searched for appropriate studies to obtain a bibliographic database. The references of selected articles and relevant reviews were searched for any missed publications that included studies conducted in India estimating periodontal diseases with adequate sample size. Clinical parameters, sample size, and findings for each study were tabulated from 2006 to 2015 (till September 15, 2015) in chronological order to observe the prevalence as well as epidemiology of periodontal disease in India. Results: The projection of periodontal disease is disturbing. In addition, the majority of studies done have used the Community Periodontal Index of Treatment Needs (CPITN) as its epidemiological tool that can grossly underestimate the presence of deep pockets. Conclusion: Current knowledge has shown that periodontitis does not present a linear progression and is not age-dependent. Moreover, its distribution and severity are strongly influenced by host susceptibility and risk factors. A structured all-inclusive survey of all districts of the states is a prerequisite for the constitution of an apt and cogent health care policy in our country. PMID:27114945

  9. Last interglacial temperature seasonality reconstructed from tropical Atlantic corals

    NASA Astrophysics Data System (ADS)

    Brocas, William M.; Felis, Thomas; Obert, J. Christina; Gierz, Paul; Lohmann, Gerrit; Scholz, Denis; Kölling, Martin; Scheffers, Sander R.

    2016-09-01

    Reconstructions of last interglacial (LIG, MIS 5e, ∼127-117 ka) climate offer insights into the natural response and variability of the climate system during a period partially analogous to future climate change scenarios. We present well preserved fossil corals (Diploria strigosa) recovered from the southern Caribbean island of Bonaire (Caribbean Netherlands). These have been precisely dated by the 230Th/U-method to between 130 and 120 ka ago. Annual banding of the coral skeleton enabled construction of time windows of monthly resolved strontium/calcium (Sr/Ca) temperature proxy records. In conjunction with a previously published 118 ka coral record, our eight records of up to 37 years in length, cover a total of 105 years within the LIG period. From these, sea surface temperature (SST) seasonality and variability in the tropical North Atlantic Ocean is reconstructed. We detect similar to modern SST seasonality of ∼2.9 °C during the early (130 ka) and the late LIG (120-118 ka). However, within the mid-LIG, a significantly higher than modern SST seasonality of 4.9 °C (at 126 ka) and 4.1 °C (at 124 ka) is observed. These findings are supported by climate model simulations and are consistent with the evolving amplitude of orbitally induced changes in seasonality of insolation throughout the LIG, irrespective of wider climatic instabilities that characterised this period. The climate model simulations suggest that the SST seasonality changes documented in our LIG coral Sr/Ca records are representative of larger regions within the tropical North Atlantic. These simulations also suggest that the reconstructed SST seasonality increase during the mid-LIG is caused primarily by summer warming. A 124 ka old coral documents, for the first time, evidence of decadal SST variability in the tropical North Atlantic during the LIG, akin to that observed in modern instrumental records.

  10. Model Thermohaline Trends in the Mediterranean Sea during the Last Years: A Change with Respect to the Last Decades?

    PubMed Central

    Soto-Navarro, F. Javier; Criado-Aldeanueva, Francisco

    2012-01-01

    Temperature and salinity outputs from ECCO (years 93–09) and GLORYS (years 03–09) models have been used to compute the thermohaline and steric sea level trends in the surface (0–150 m), intermediate (150 m–600 m), and deep (600 m–bottom) layers of the Mediterranean Sea. Some changes with respect to the second half of the 20th century have been observed: the cooling of the upper waters of the entire eastern basin since 1950 seems to have vanished; the warming of WMDW historically reported for the second half of the last century could have reversed, although there is no agreement between both models at this point (trends of different sign are predicted); the salinification of WMDW reported for the previous decades is not observed in the south-westernmost area in the period 93–09, and a clear change from positive to negative in the steric sea level trend with respect to the period 93–05 is detected due to the sharp decreasing steric sea level of years 02–06. PMID:22654595

  11. A chironomid-inferred summer temperature reconstruction from subtropical Australia during the last glacial maximum (LGM) and the last deglaciation

    NASA Astrophysics Data System (ADS)

    Chang, Jie Christine; Shulmeister, James; Woodward, Craig; Steinberger, Lincoln; Tibby, John; Barr, Cameron

    2015-08-01

    A chironomid-based mean February temperature reconstruction from Welsby Lagoon, North Stradbroke Island, Australia covering the last glacial maximum (LGM) and deglaciation (between c. ∼23.2 and 15.5 cal ka BP) is presented. Mean February temperature reconstructions show a maximum inferred cooling of c. ∼6.5 °C at c. ∼18.5 cal ka BP followed by rapid warming to near Holocene values immediately after the LGM. The inferred timing, magnitude and trend of maximum cooling and warming display strong similarities to marine records from areas affected by the East Australian current (EAC). The warming trend started at c. ∼18.1 cal ka BP and is consistent with the start of deglaciation from Antarctic records. Near Holocene values are maintained through the deglaciation to 15.5 cal ka BP. These records suggest that changes in the Australian subtropics are linked to southern high latitudes.

  12. Draft Genome Sequence of Klebsiella pneumoniae UCD-JA29 Isolated from a Patient with Sepsis

    PubMed Central

    Alexiev, Alexandra; Coil, David A.; Jospin, Guillaume; Adams, Jason Y.

    2016-01-01

    Here, we present the 6,155,188-bp draft genome sequence of Klebsiella pneumoniae UCD-JA29, isolated from blood cultures from a patient with sepsis at the University of California, Davis Medical Center in Sacramento, California, USA. PMID:27151785

  13. Transcriptome Analysis in Haematococcus pluvialis: Astaxanthin Induction by Salicylic Acid (SA) and Jasmonic Acid (JA)

    PubMed Central

    Wu, Guanxun; Li, Guoqiang; Sun, Haifeng; Deng, Suzhen; Shen, Yicheng; Chen, Guoqiang; Zhang, Ruihao; Meng, Chunxiao; Zhang, Xiaowen

    2015-01-01

    Haematococcus pluvialis is an astaxanthin-rich microalga that can increase its astaxanthin production by salicylic acid (SA) or jasmonic acid (JA) induction. The genetic transcriptome details of astaxanthin biosynthesis were analyzed by exposing the algal cells to 25 mg/L of SA and JA for 1, 6 and 24 hours, plus to the control (no stress). Based on the RNA-seq analysis, 56,077 unigenes (51.7%) were identified with functions in response to the hormone stress. The top five identified subcategories were cell, cellular process, intracellular, catalytic activity and cytoplasm, which possessed 5600 (~9.99%), 5302 (~9.45%), 5242 (~9.35%), 4407 (~7.86%) and 4195 (~7.48%) unigenes, respectively. Furthermore, 59 unigenes were identified and assigned to 26 putative transcription factors (TFs), including 12 plant-specific TFs. They were likely associated with astaxanthin biosynthesis in Haematococcus upon SA and JA stress. In comparison, the up-regulation of differential expressed genes occurred much earlier, with higher transcript levels in the JA treatment (about 6 h later) than in the SA treatment (beyond 24 h). These results provide valuable information for directing metabolic engineering efforts to improve astaxanthin biosynthesis in H. pluvialis. PMID:26484871

  14. Integrated metabolomic and proteomic analysis reveals systemic responses of Rubrivivax benzoatilyticus JA2 to aniline stress.

    PubMed

    Mujahid, Md; Prasuna, M Lakshmi; Sasikala, Ch; Ramana, Ch Venkata

    2015-02-01

    Aromatic amines are widely distributed in the environment and are major environmental pollutants. Although degradation of aromatic amines is well studied in bacteria, physiological adaptations and stress response to these toxic compounds is not yet fully understood. In the present study, systemic responses of Rubrivivax benzoatilyticus JA2 to aniline stress were deciphered using metabolite and iTRAQ-labeled protein profiling. Strain JA2 tolerated high concentrations of aniline (30 mM) with trace amounts of aniline being transformed to acetanilide. GC-MS metabolite profiling revealed aniline stress phenotype wherein amino acid, carbohydrate, fatty acid, nitrogen metabolisms, and TCA (tricarboxylic acid cycle) were modulated. Strain JA2 responded to aniline by remodeling the proteome, and cellular functions, such as signaling, transcription, translation, stress tolerance, transport and carbohydrate metabolism, were highly modulated. Key adaptive responses, such as transcription/translational changes, molecular chaperones to control protein folding, and efflux pumps implicated in solvent extrusion, were induced in response to aniline stress. Proteo-metabolomics indicated extensive rewiring of metabolism to aniline. TCA cycle and amino acid catabolism were down-regulated while gluconeogenesis and pentose phosphate pathways were up-regulated, leading to the synthesis of extracellular polymeric substances. Furthermore, increased saturated fatty acid ratios in membranes due to aniline stress suggest membrane adaptation. The present study thus indicates that strain JA2 employs multilayered responses: stress response, toxic compound tolerance, energy conservation, and metabolic rearrangements to aniline. PMID:25388363

  15. Transcriptome Analysis in Haematococcus pluvialis: Astaxanthin Induction by Salicylic Acid (SA) and Jasmonic Acid (JA).

    PubMed

    Gao, Zhengquan; Li, Yan; Wu, Guanxun; Li, Guoqiang; Sun, Haifeng; Deng, Suzhen; Shen, Yicheng; Chen, Guoqiang; Zhang, Ruihao; Meng, Chunxiao; Zhang, Xiaowen

    2015-01-01

    Haematococcus pluvialis is an astaxanthin-rich microalga that can increase its astaxanthin production by salicylic acid (SA) or jasmonic acid (JA) induction. The genetic transcriptome details of astaxanthin biosynthesis were analyzed by exposing the algal cells to 25 mg/L of SA and JA for 1, 6 and 24 hours, plus to the control (no stress). Based on the RNA-seq analysis, 56,077 unigenes (51.7%) were identified with functions in response to the hormone stress. The top five identified subcategories were cell, cellular process, intracellular, catalytic activity and cytoplasm, which possessed 5600 (~9.99%), 5302 (~9.45%), 5242 (~9.35%), 4407 (~7.86%) and 4195 (~7.48%) unigenes, respectively. Furthermore, 59 unigenes were identified and assigned to 26 putative transcription factors (TFs), including 12 plant-specific TFs. They were likely associated with astaxanthin biosynthesis in Haematococcus upon SA and JA stress. In comparison, the up-regulation of differential expressed genes occurred much earlier, with higher transcript levels in the JA treatment (about 6 h later) than in the SA treatment (beyond 24 h). These results provide valuable information for directing metabolic engineering efforts to improve astaxanthin biosynthesis in H. pluvialis. PMID:26484871

  16. Partial Activation of SA- and JA-Defensive Pathways in Strawberry upon Colletotrichum acutatum Interaction.

    PubMed

    Amil-Ruiz, Francisco; Garrido-Gala, José; Gadea, José; Blanco-Portales, Rosario; Muñoz-Mérida, Antonio; Trelles, Oswaldo; de Los Santos, Berta; Arroyo, Francisco T; Aguado-Puig, Ana; Romero, Fernando; Mercado, José-Ángel; Pliego-Alfaro, Fernando; Muñoz-Blanco, Juan; Caballero, José L

    2016-01-01

    Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa) cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5, and FaPR10) were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen. PMID:27471515

  17. Partial Activation of SA- and JA-Defensive Pathways in Strawberry upon Colletotrichum acutatum Interaction

    PubMed Central

    Amil-Ruiz, Francisco; Garrido-Gala, José; Gadea, José; Blanco-Portales, Rosario; Muñoz-Mérida, Antonio; Trelles, Oswaldo; de los Santos, Berta; Arroyo, Francisco T.; Aguado-Puig, Ana; Romero, Fernando; Mercado, José-Ángel; Pliego-Alfaro, Fernando; Muñoz-Blanco, Juan; Caballero, José L.

    2016-01-01

    Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa) cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5, and FaPR10) were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen. PMID:27471515

  18. Indonesian Throughflow variability over the last glacial cycle (Invited)

    NASA Astrophysics Data System (ADS)

    Holbourn, A. E.; Kuhnt, W.; Regenberg, M.; Xu, J.; Hendrizan, M.; Schröder, J.

    2013-12-01

    over the Australian continent. However, the development of the monsoon was asynchronous over the region, which we relate to changes in landmass exposure during deglacial sea-level rise. Thus, we find that sea-level exerted a major control on ITF properties through the last glacial termination by altering gateway configuration and precipitation-evaporation budgets over the Indonesian archipelago.

  19. Ionospheric seismology: The last step before true contributions to seismology?

    NASA Astrophysics Data System (ADS)

    Lognonne, P. H.; Rakoto, V.; Khelfi, K.; Rolland, L.; Astafyeva, E.; Occhipinti, G.; Coisson, P.; Drilleau, M.; Makela, J. J.; Walwer, D.

    2015-12-01

    Ionospheric seismology, which was at most seen as an exotic way to record doubtful signals in the early 2000 has gain maturity, especially after the worldwide observations made during the Tohoku 2011 earthquake and tsunami. The last steps for important contributions in seismology will request however these data to be modeled and inverted in a way precise enough for new and original constraints on the seismic sources, amplitude of tsunamis and atmospheric/interior seismic/acoustic velocities profiles. Ionospheric observations are now able to provide time depending maps of the ionospheric waves, enabling the location of the sources, measurement of the wave speed and amplitude, for both acoustic waves above or close the epicenter or remotely observed Rayleigh and Tsunami waves. Are these data good enough for inversions? Are the modelling techniques good enought for inversions? We therefore first compare and illustrate the different observation techniques: ground, air-based and space-based GPS and airglow, focusing on the Tohoku 2011 and Haida Gwai earthquake and tsunamis, discuss the physics enabling the conversion of seismic waves into electron perturbation (for GPS data) and light emission (for airglow) and signal to noise issues. Comparison between data and waveforms modelling are then shown by using either Normal Mode summations for remote detections or Spectral Element techniques for local detections, with an emphasis in the later case on non-linear effects and TEC post-seismic depletions. A special attention is made on the sensitivity of the waveforms to the various parameters of the models, including the sensitivity of the conversion of the seismic to atmospheric signals with the atmosphere structure, the crust subsurface and the ocean thickness and the sensitivity of the conversion of the atmospheric to ionospheric signal with respect to local time, ionospheric state and magnetic latitude. We then present the perspectives in term of inversion for both the

  20. High-resolution climate simulation of the last glacial maximum

    SciTech Connect

    Erickson III, David J

    2008-01-01

    The climate of the last glacial maximum (LGM) is simulated with a high-resolution atmospheric general circulation model, the NCAR CCM3 at spectral truncation of T170, corresponding to a grid cell size of roughly 75 km. The purpose of the study is to assess whether there are significant benefits from the higher resolution simulation compared to the lower resolution simulation associated with the role of topography. The LGM simulations were forced with modified CLIMAP sea ice distribution and sea surface temperatures (SST) reduced by 1 C, ice sheet topography, reduced CO{sub 2}, and 21,000 BP orbital parameters. The high-resolution model captures modern climate reasonably well, in particular the distribution of heavy precipitation in the tropical Pacific. For the ice age case, surface temperature simulated by the high-resolution model agrees better with those of proxy estimates than does the low-resolution model. Despite the fact that tropical SSTs were only 2.1 C less than the control run, there are many lowland tropical land areas 4-6 C colder than present. Comparison of T170 model results with the best constrained proxy temperature estimates (noble gas concentrations in groundwater) now yield no significant differences between model and observations. There are also significant upland temperature changes in the best resolved tropical mountain belt (the Andes). We provisionally attribute this result in part as resulting from decreased lateral mixing between ocean and land in a model with more model grid cells. A longstanding model-data discrepancy therefore appears to be resolved without invoking any unusual model physics. The response of the Asian summer monsoon can also be more clearly linked to local geography in the high-resolution model than in the low-resolution model; this distinction should enable more confident validation of climate proxy data with the high-resolution model. Elsewhere, an inferred salinity increase in the subtropical North Atlantic may have

  1. Hydrological changes over Papua New Guinea during the last deglaciation

    NASA Astrophysics Data System (ADS)

    Bard, Edouard; Ménot, Guillemette; Rostek, Frauke; Tachikawa, Kazuyo; de Garidel-Thoron, Thibault; Bonnet, Nicolas

    2014-05-01

    Today the Fly River in Papua New Guinea is a major sediment contributor to the global ocean (the first in PNG and the 13st globally according to Milliman & Fansworth 2011 CUP). In order to reconstruct hydrological changes during the glacial period, we studied a deep-sea core located in the Gulf of Papua, just in front of the Fly River mouth. The history of detrital input in core MD97-2134 was reconstructed at high resolution by measuring various inorganic and organic proxies. In particular, we present Fe, Ti, Ca profiles measured with an ITRAX XRF scanner. We also measured molecular proxies such as n-alkanes by GC and tetraethers by LC-MS to derive BIT index values. These independent proxies provide a coherent picture for the period covering the last 30 thousands of years. The riverine input was much stronger during the glacial period with n-alkanes, BIT and Ti/Ca values several times higher than during the Holocene (factor 2 for n-alkanes, 2-3 for the BIT and 6-7 for Ti/Ca). This systematic increase is the likely signature of stronger precipitations superimposed on physiographical changes. The latter are linked to lower sea levels during the glacial period, which led to a shorter distance from the coast and probably to a widening of the drainage basin. In addition to these expected changes, we also observe prominent maxima of the riverine input during specific millennium-scale periods corresponding chronologically to Heinrich events # 1, 2, 3 and the Younger Dryas event. These precipitation maxima are in phase with those observed in Indonesia (Muller et al. 2012 Geology, Ayliffe et al. Nat. Geo. 2013), but in antiphase with the drought periods reconstructed farther north, notably in China (Wang et al. 2001 Science). The spatial distribution of precipitation changes constitutes the clear signature of wide latitudinal shifts of the ITCZ during H events. The resolution of our Papua record allows studying further important details, providing evidence for two phases

  2. Atlantic forcing of Amazonian climates in the last ice age

    NASA Astrophysics Data System (ADS)

    Bush, M. B.; Mosblech, N.; Valencia, B. G.; Hodell, D. A.; Gosling, W. D.; Van Calsteren, P. W.; Thomas, L. E.; Curtis, J. H.

    2011-12-01

    An absence of study sites means that the relative influence of orbitally driven presession cycles and millenial scale variability upon ice-age Amazonian precipitation is unknown. Here we present a continuous isotopic (δO18 and C13) record spanning the period from ~93-8 ka, from the aseasonal forests of Amazonian Ecuador. The variability in δO18 depletion is probably related to the relative strength of evapotranspired moisture (less depleted) and tropical Atlantic moisture carried across the basin by the South American Low Level Jet (more depleted). Times of strengthened South American Low Level Jet probably correspond to increased overall moisture availability and hence elevated precipitation. The occurrence of markedly depleted δO18 signatures during Heinrich events suggests a strong influence of the Atlantic Ocean on this system, and that these northern hemispheric stadials induced wet episodes in western Amazonia. Weakening of the Atlantic Meridional Overturning Circulation (AMOC) has been suggested to strengthen the South American Low Level Jet. The isotopic records reveal strong cohesion with previously published records from southern Brazil. A precessional influence amplifies the north Atlantic signal between c. 93 ka and 50 ka. However, after c. 50 ka the precessional signal weakens, perhaps sugesting that at a critical size the Laurentide ice mass exerted a strong influence on Neotropical climates suppressing the weaker forcing associated with precession. Contrary to long-standing expectation, the Last Glacial Maximum (21 ± 2 ka) does not stand out as time of aridity in this record. However, between c. 35 ka and 18 ka there is a drift toward less depleted rainfall. One hypothesis to account for this observation is that the climate was becoming more seasonal as the Intertropical Convergence Zone (ITCZ) formed further south than its modern location. The resulting weakened influence of the South American Summer Monsoon (SASM) would probably reduce wet

  3. Urban Geocaching: what Happened in Lisbon during the Last Decade?

    NASA Astrophysics Data System (ADS)

    Nogueira Mendes, R.; Rodrigues, T.; Rodrigues, A. M.

    2013-05-01

    Created in 2000 in the United States of America, Geocaching has become a major phenomenon all around the world, counting actually with millions of Geocaches (or caches) that work as a recreational motivation for millions of users, called Geocachers. During the last 30 days over 5,000,000 new logs have been submitted worldwide, disseminating individual experiences, motivations, emotions and photos through the official Geocaching website (www.geocaching.com), and several official or informal national web forums. The activity itself can be compared with modern treasure hunting that uses handheld GPS, Smartphones or Tablets, WEB 2.0, wiki features and technologies to keep Geocachers engaged with their activity, in a strong social-network. All these characteristics make Geocaching an activity with a strong geographic component that deals closely with the surrounding environment where each cache has been hidden. From previous work, significance correlation has been found regarding hides and natural/rural environments, but metropolitan and urban areas like Lisbon municipality (that holds 3.23% of the total 27534 Portuguese caches), still registers the higher density of Geocaches, and logs numbers. Lacking "natural/rural" environment, Geocaching in cities tend to happen in symbolic areas, like public parks and places, sightseeing spots and historical neighborhoods. The present study looks to Geocaching within the city of Lisbon, in order to understand how it works, and if this activity reflects the city itself, promoting its image and cultural heritage. From a freely available dataset that includes all Geocaches that have been placed in Lisbon since February 2001, spatial analysis has been conducted, showing the informal preferences of this activity. Results show a non-random distribution of caches within the study area, similar to the land use distribution. Preferable locations tend to be in iconic places of the city, usually close to the

  4. Mertz Ice Shelf Dynamics in the Last Twenty Years

    NASA Astrophysics Data System (ADS)

    Wang, X.; Cheng, X.; Shum, C.

    2013-12-01

    . These parameters extracted from remote sensing and altimetry data will provide additional information for studies of the evolution of iceberg, especially in iceberg tracking system. Mertz Ice Shelf Dynamics in the last 20 years

  5. Analysis of satellite precipitation over East Africa during last decades

    NASA Astrophysics Data System (ADS)

    Cattani, Elsa; Wenhaji Ndomeni, Claudine; Merino, Andrés; Levizzani, Vincenzo

    2016-04-01

    Daily accumulated precipitation time series from satellite retrieval algorithms (e.g., ARC2 and TAMSAT) are exploited to extract the spatial and temporal variability of East Africa (EA - 5°S-20°N, 28°E-52°E) precipitation during last decades (1983-2013). The Empirical Orthogonal Function (EOF) analysis is applied to precipitation time series to investigate the spatial and temporal variability in particular for October-November-December referred to as the short rain season. Moreover, the connection among EA's precipitation, sea surface temperature, and soil moisture is analyzed through the correlation with the dominant EOF modes of variability. Preliminary results concern the first two EOF's modes for the ARC2 data set. EOF1 is characterized by an inter-annual variability and a positive correlation between precipitation and El Niño, positive Indian Ocean Dipole mode, and soil moisture, while EOF2 shows a dipole structure of spatial variability associated with a longer scale temporal variability. This second dominant mode is mostly linked to sea surface temperature variations in the North Atlantic Ocean. Further analyses are carried out by computing the time series of the joint CCI/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETCCDI, http://etccdi.pacificclimate.org/index.shtml), i.e. RX1day, RX5day, CDD, CDD, CWD, SDII, PRCPTOT, R10, R20. The purpose is to identify the occurrenes of extreme events (droughts and floods) and extract precipitation temporal variation by trend analysis (Mann-Kendall technique). Results for the ARC2 data set demonstrate the existence of a dipole spatial pattern in the linear trend of the time series of PRCPTOT (annual precipitation considering days with a rain rate > 1 mm) and SDII (average precipitation on wet days over a year). A negative trend is mainly present over West Ethiopia and Sudan, whereas a positive trend is exhibited over East Ethiopia and Somalia. CDD (maximum number of consecutive dry days) and

  6. Field Topology Analysis of a Long-lasting Coronal Sigmoid

    NASA Astrophysics Data System (ADS)

    Savcheva, A. S.; van Ballegooijen, A. A.; DeLuca, E. E.

    2012-01-01

    We present the first field topology analysis based on nonlinear force-free field (NLFFF) models of a long-lasting coronal sigmoid observed in 2007 February with the X-Ray Telescope on Hinode. The NLFFF models are built with the flux rope insertion method and give the three-dimensional coronal magnetic field as constrained by observed coronal loop structures and photospheric magnetograms. Based on these models, we have computed horizontal maps of the current and the squashing factor Q for 25 different heights in the corona for all six days of the evolution of the region. We use the squashing factor to quantify the degree of change of the field line linkage and to identify prominent quasi-separatrix layers (QSLs). We discuss the major properties of these QSL maps and devise a way to pick out important QSLs since our calculation cannot reach high values of Q. The complexity in the QSL maps reflects the high degree of fragmentation of the photospheric field. We find main QSLs and current concentrations that outline the flux rope cavity and that become characteristically S-shaped during the evolution of the sigmoid. We note that, although intermittent bald patches exist along the length of the sigmoid during its whole evolution, the flux rope remains stable for several days. However, shortly after the topology of the field exhibits hyperbolic flux tubes (HFT) on February 7 and February 12 the sigmoid loses equilibrium and produces two B-class flares and associated coronal mass ejections (CMEs). The location of the most elevated part of the HFT in our model coincides with the inferred locations of the two flares. Therefore, we suggest that the presence of an HFT in a coronal magnetic configuration may be an indication that the system is ready to erupt. We offer a scenario in which magnetic reconnection at the HFT drives the system toward the marginally stable state. Once this state is reached, loss of equilibrium occurs via the torus instability, producing a CME.

  7. ANTscape: ANTARCTIC PALEOTOPOGRAPHIC MAPS FOR THE LAST 100 MILLION YEARS

    NASA Astrophysics Data System (ADS)

    Barrett, P. J.; Francis, J.; Gohl, K.; Haywood, A. M.; Siddoway, C. S.; Wilson, D. S.

    2009-12-01

    ANTscape is a project of the Antarctic Climate Evolution (ACE) Research Program to develop a series of maps to show the changes in Antarctic paleotopography over the last ~100 million years. The reconstructions will provide a base for summarising a range of paleoenvironmental data, and be useful both as inputs for the next generation of ice sheet-ice shelf models, and for credible and realistic visualization of past landscapes to promote wider appreciation of past changes in the Antarctic environment. For younger periods (Cenozoic) the present-day bedrock topography from the SCAR BEDMAP project will be used as a starting point for reconstructing past paleotopography, moving to BEDMAP 2 when it becomes available. However for older periods researchers will have to draw more on current knowledge of plate movements, tectonic deformation, thermal evolution, modeling landscape evolution and personal geological experience. Because of the scarcity of geological data, we recognise that the reconstructions will entail considerable geological interpretation. However even poorly constrained reconstructions will be a significant improvement on the current practice of using present day topography for models of past ice sheets, when we know past topography was different. Six time slices, each representing a significant climatic regime or shift, have been identified for a map. They are for 4, 14, 34, 50, 70 and 92 Ma. Work has begun first for a map for 34 Ma (Wilson and Luyendyk, 2009, Geophysical Research Letters), a time that is far enough back for there to be a significantly different topography, but not so far back that reconstruction is seriously unconstrained. It is also of great interest to paleoclimatologists as the time prior to which the landscape was largely ice-free, and on which the first continental ice-sheet formed. The maps prepared by ANTscape will depend not only on restoration of Antarctic continental geography by reversing horizontal and vertical tectonic

  8. Last Glacial Maximum in South America: Proxies and Model Results

    NASA Astrophysics Data System (ADS)

    Wainer, I.; Ledru, M. P.; Clauzet, G.; Otto-Bliesner, B.; Brady, E.

    2003-04-01

    The lack of paleo proxies to define Full Glacial conditions in South America (see COHMAP 1988) prevented accurate climatic reconstitution until recently. It is believed that full glacial climates throughout South America were cooler than today by about 5°C with moisture patterns showing distinct regional differences.Results show that from Equator to pole, four areas can be characterized from lacustrine records, travertine and speleothems analysis: the first region, between 0 and 25°S latitude, recorded a hiatus in sedimentation with an absence of organic matter deposition in all lowland records, while the Andes Amazonian-moisture-dependant-forests were drastically reduced and showed the set up of an open vegetation. Climates were defined as drier than today with less precipitation and reduction in soil moisture supply. On the other hand, observations on travertines on the northeastern coastal area of the state of Bahia (also at low latitudes) certify a climate more humid than today. South of 25°S, in the temperate regions of northern Patagonia, lake levels were higher than today, snow precipitation in the Southern Bolivia increased with an accompanying increase in speleothems formations in southern Brazil. This was interpreted as being associated with moister and cooler climates than today in this area. At higher latitudes the low lake-levels recorded, indicate an arid climate. These observations based on paleodata are compared to the analysis from simulation results of the Paleoclimate version of the National Center for Atmospheric Research coupled climate system model (PALEO CCSM) for the Last Glacial Maximum and present day. Analysis of the LGM wind simulation for the tropical Atlantic show that the convergence zone does not extend all the way into the continent. This prevents moisture inflow into the adjacent continental area (equatorial NE Brazil). Paleo proxies results, as explained above, are consistent with this scenario. At higher latitudes (south of 50

  9. North Atlantic sea-level variability during the last millennium

    NASA Astrophysics Data System (ADS)

    Gehrels, Roland; Long, Antony; Saher, Margot; Barlow, Natasha; Blaauw, Maarten; Haigh, Ivan; Woodworth, Philip

    2014-05-01

    multi-decadal to centennial changes in wind and air pressure are more important than mass flux from land-based ice as drivers of North Atlantic sea-level variability during the last millennium.

  10. The last ~1 million years of carbonatite volcanism in northern Tanzania; last gasp of a decaying rift?

    NASA Astrophysics Data System (ADS)

    Jones, A.

    2003-04-01

    Continued monitoring of volcanic activity at Oldoinyo Lengai for the last ~35 years suggests that this central volcano has become a highly evolved low temperature/low volume carbonatite-nephelinite system. The sustained intermingling of silicate and carbonatitic eruptions for most of this volcano's history contrasts sharply with the two-stage sequential development of neighbouring Kerimasi (nephelinite then carbonatite). The footprint of the older Kerimasi volcano is effected by active faulting of earlier flood lavas along the west rift wall. The mineralogy, petrology and geochemistry of both volcanos generally conform with the LeBas model of carbonatite-nephelinite volcanism for the eastern arm of the EAR. However, their overall differences in bulk chemistry suggest that their ~15 km horizontal separation at the surface, reflects compositional heterogeneity of the mantle source over a similar length scale. This is consistent with primary melt segregation at relatively shallow mantle depths, and crustal delivery along pipe-like conduits with minimal lateral transport. The surrounding rift valley floor is pock-marked with numerous small volcanic structures, such as tuff cones, craters and minor lava flows. The ages of these minor volcanos are bracketed by the two larger central volcanos, and also contain both carbonatite and alkaline silicate magmas; they extend the compositional range and suggest deeper sources for periodic small volume primary melilitite magmas. Their xenolith populations are consistent with an extended history of metasomatised mantle peridotites characterised by increasing amphibole, mica, and clinopyroxene at the expense of orthopyroxene. Megacrysts and cumulate-textured xenoliths are also consistent with repeated occupation of vertical conduits and local sidewall crystallisation at depths close to the Moho. Overall, the recent volcanic activity represents highly evolved small volume batches of mantle melts with high carbonate and CO2, and