WorldWideScience

Sample records for rapidly changing variables

  1. Hydrothermal iron flux variability following rapid sea level changes

    National Research Council Canada - National Science Library

    Middleton, Jennifer L; Langmuir, Charles H; Mukhopadhyay, Sujoy; McManus, Jerry F; Mitrovica, Jerry X

    2016-01-01

    .... Mir sediments reveal sixfold to eightfold increases in hydrothermal iron and copper deposition during the Last Glacial Maximum, followed by a rapid decline during the sea level rise associated with deglaciation...

  2. Rapidly variable relatvistic absorption

    Science.gov (United States)

    Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

    2017-10-01

    I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

  3. Environmental variability drives rapid and dramatic changes in nutrient limitation of tropical macroalgae with different ecological strategies

    Science.gov (United States)

    Clausing, Rachel J.; Fong, Peggy

    2016-06-01

    Nitrogen (N) or phosphorus (P) limits primary productivity in nearly every ecosystem worldwide, yet how limitation changes over time, particularly in connection to variation in environmental drivers, remains understudied. We evaluated temporal and species-specific variability in the relative importance of N and P limitation among tropical macroalgae in two-factor experiments conducted twice after rains and twice after dry conditions to explore potential linkages to environmental drivers. We studied three common macroalgal species with varying ecological strategies: a fast-growing opportunist, Dictyota bartayresiana; and two calcifying species likely to be slower growing, Galaxaura fasciculata and Padina boryana. On the scale of days to weeks, nutrient responses ranged among and within species from no limitation to increases in growth by 20 and 40 % over controls in 3 d with N and P addition, respectively. After light rain or dry conditions, Dictyota grew rapidly (up to ~60 % in 3 d) with little indication of nutrient limitation, while Padina and Galaxaura shifted between N, P, or no limitation. All species grew slowly or lost mass after a large storm, presumably due to unfavorable conditions on the reef prior to the experiment that limited nutrient uptake. Padina and Galaxaura both became nutrient limited 3 d post-storm, while Dictyota did not. These results suggest that differing capabilities for nutrient uptake and storage dictate the influence of nutrient history and thus drive nutrient responses and, in doing so, may allow species with differing ecological strategies to coexist in a fluctuating environment. Moreover, the great variability in species' responses indicates that patterns of nutrient limitation are more complex than previously recognized, and generalizations about N versus P limitation of a given system may not convey the inherent complexity in governing conditions and processes.

  4. How The Rapid Climatic Variability of The Last Ice Age Affected Neandertal Extinction and Cultural Changes During The Upper Palaeolithic

    Science.gov (United States)

    D'Errico, F.; Sanchez Goñi, M.-F.; Vanhaeren, M.; Grousset, F.; Valladas, H.

    We present a synthesis of the results obtained in the framework of a multidisciplinary research project funded by the ECLIPSE CNRS program the objectif of which is to explore possible relationships between cultural and climatic changes during the OIS 1- 3. With this goal in mind, a comprehensive database including European Palaeolithic sites location and C14 conventional and AMS dates was created and correlated to climatic variations as established by continental and marine proxies. This database in- cludes the C14 dates from living sites and painted caves as well as palaeoclimatic data (isotopes, pollen, foraminifers, alkenones, Ice Rafted Detritus) from IMAGES marine cores and, in particular, from two cores retrieved off the Iberian margin. Correlation of archeological and climatic data for the Middle-Upper Palaeolithic transition indicates that at a global scale, climate was not the driving force determining the colonisation of Europe by Anatomically Modern Humans. At a regional scale, however, climate might have conditionned the timing of this colonisation and of neandertal extinction, particularly in the mediterranean area. We also found that a clear and previously unde- tected synchronism exists between the beginning of each Heinrich events (4 to1) and the developpment of Upper Palaeolithic cultures (Aurignacian, Gravettian, Solutrean and Magdalenian respectively). Cave art also seems affected by the climatic variabil- ity. We discovered that a major gap in cave art production corresponding to the period between 22.7 and 19.4 ky 14C BP (26 and 23.3 cal ky BP) is contemporary with the Heinrich 2 climatic deterioration.

  5. Rapid BAL Variability: Re-Emerging Absorption

    Directory of Open Access Journals (Sweden)

    Damla Erakuman

    2017-11-01

    Full Text Available We study BAL variations of SDSS J141955.28+522741.4 utilizing 32 epochs of spectroscopic observations from SDSS. We identify three individual BAL troughs for C iv and one BAL trough for Si iv. The deepest C iv BAL trough shows significant EW variations in timescales of a few 10 h. The fast component of the deepest C iv BAL presents disappearance and re-emergence preserving its initial velocity range and profile. All identified BAL troughs show coordinated variations supporting that the possible mechanism behind variations are the ionization level changes of the absorbing gas.

  6. Two decadally resolved records from north-west European peat bogs show rapid climate changes associated with solar variability during the mid-late Holocene

    NARCIS (Netherlands)

    Mauquoy, D.; Yeloff, D.; van Geel, B.; Charman, D.J.; Blundell, A.

    2008-01-01

    Two C-14 accelerator mass spectrometry (AMS) wiggle-match dated peat sequences from Denmark and northern England record changes in mire Surface wetness reconstructed using plant macrofossil and testate amoebae analyses. A number of significant mid-late Holocene climatic deteriorations (wet shifts)

  7. Response variability in rapid automatized naming predicts reading comprehension.

    Science.gov (United States)

    Li, James J; Cutting, Laurie E; Ryan, Matthew; Zilioli, Monica; Denckla, Martha B; Mahone, E Mark

    2009-10-01

    A total of 37 children ages 8 to 14 years, screened for word-reading difficulties (23 with attention-deficit/hyperactivity disorder, ADHD; 14 controls) completed oral reading and rapid automatized naming (RAN) tests. RAN trials were segmented into pause and articulation time and intraindividual variability. There were no group differences on reading or RAN variables. Color- and letter-naming pause times and number-naming articulation time were significant predictors of reading fluency. In contrast, number and letter pause variability were predictors of comprehension. Results support analysis of subcomponents of RAN and add to literature emphasizing intraindividual variability as a marker for response preparation, which has relevance to reading comprehension.

  8. Mirador - Climate Variability and Change

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth Science data access made simple. NASA's role in climate variability study is centered around providing the global scale observational data sets on oceans and...

  9. Rapid variability of OB-stars: nature and diagnostic value.

    Science.gov (United States)

    Baade, D.

    In the past decade, rapid photospheric variability has been recognized as the non-standard property that perhaps is the most common one among early-type stars. These proceedings offer an unusually complete overview of the existing observations. They are equally complete in their reflectance of the presently considered models. Because the simple definition 'on a rotational time scale' of the qualifier 'rapid' used in the title is very adequate for many stars, modulation is a strong contender also as a general model. The model that can be made to formally reproduce the widest range of observations is nonradial pulsation which, therefore, has earned itself the somewhat ambiguous reputation as a model for everything. An attraction of this model is that it would give the possibility to infer also structural and evolutionary quantities. It was the second purpose of the workshop to offer at least a glimpse of this potential.

  10. Indigenous people's detection of rapid ecological change.

    Science.gov (United States)

    Aswani, Shankar; Lauer, Matthew

    2014-06-01

    When sudden catastrophic events occur, it becomes critical for coastal communities to detect and respond to environmental transformations because failure to do so may undermine overall ecosystem resilience and threaten people's livelihoods. We therefore asked how capable of detecting rapid ecological change following massive environmental disruptions local, indigenous people are. We assessed the direction and periodicity of experimental learning of people in the Western Solomon Islands after a tsunami in 2007. We compared the results of marine science surveys with local ecological knowledge of the benthos across 3 affected villages and 3 periods before and after the tsunami. We sought to determine how people recognize biophysical changes in the environment before and after catastrophic events such as earthquakes and tsunamis and whether people have the ability to detect ecological changes over short time scales or need longer time scales to recognize changes. Indigenous people were able to detect changes in the benthos over time. Detection levels differed between marine science surveys and local ecological knowledge sources over time, but overall patterns of statistically significant detection of change were evident for various habitats. Our findings have implications for marine conservation, coastal management policies, and disaster-relief efforts because when people are able to detect ecological changes, this, in turn, affects how they exploit and manage their marine resources. © 2014 Society for Conservation Biology.

  11. Marine assemblages respond rapidly to winter climate variability.

    Science.gov (United States)

    Morley, James W; Batt, Ryan D; Pinsky, Malin L

    2017-07-01

    Even species within the same assemblage have varied responses to climate change, and there is a poor understanding for why some taxa are more sensitive to climate than others. In addition, multiple mechanisms can drive species' responses, and responses may be specific to certain life stages or times of year. To test how marine species respond to climate variability, we analyzed 73 diverse taxa off the southeast US coast in 26 years of scientific trawl survey data and determined how changes in distribution and biomass relate to temperature. We found that winter temperatures were particularly useful for explaining interannual variation in species' distribution and biomass, although the direction and magnitude of the response varied among species from strongly negative, to little response, to strongly positive. Across species, the response to winter temperature varied greatly, with much of this variation being explained by thermal preference. A separate analysis of annual commercial fishery landings revealed that winter temperatures may also impact several important fisheries in the southeast United States. Based on the life stages of the species surveyed, winter temperature appears to act through overwinter mortality of juveniles or as a cue for migration timing. We predict that this assemblage will be responsive to projected increases in temperature and that winter temperature may be broadly important for species relationships with climate on a global scale. © The Authors Global Change Biology Published by John Wiley & Sons Ltd.

  12. Public health in a rapidly changing world

    Directory of Open Access Journals (Sweden)

    Tatiana I. Andreeva

    2014-06-01

    Full Text Available Several months in 2013 and 2014 have been a hardly predictable time in Ukraine, and the situation is still far from being stable. This made the editorial team of TCPHEE based in Ukraine postpone publishing consecutive issues. However, while the situation still requires practical steps, many aspects including those related to public health require analysis and debate. Thus we invite opinion pieces and studies addressing all different spheres of how public health should function under changing social circumstances. There might be a wide range of such related topics. The most obvious ones are those linked to changing living conditions. Many studies have been undertaken and published with regard to health threats to refugees, people involved in natural or technical disasters (Noji, 2005. Along with environmental health threats, there might be mental health disturbances (World Health Organization, 1992 resulting from long-term strain, losses et cetera. Another important focus is related to changes in health services provision. Crimea, which is a former Ukrainian territory now occupied by the Russian Federation, was among those in Ukraine highly affected with HIV (Dehne, Khodakevich, Hamers, & Schwartlander, 1999. This was responded by several NGOs actively providing harm reduction services to high-risk groups along with methadone substitution therapy to opiate users and antiretroviral medicines to those HIV-infected (Curtis, 2010. However, there are news reports that Russia is going to stop provision of methadone (kommersant.ru, 2014. As opiate substitution programs have been shown an effective approach towards preventing HIV transmission among people who inject drugs (MacArthur et al., 2012, such change in public health policies might affect not only most at risk populations but their partners and population as a whole as well resulting in a rapid spread of HIV. Yet another related topic is that of how health services can be organized at times of

  13. Climate variability and vulnerability to climate change: a review.

    Science.gov (United States)

    Thornton, Philip K; Ericksen, Polly J; Herrero, Mario; Challinor, Andrew J

    2014-11-01

    The focus of the great majority of climate change impact studies is on changes in mean climate. In terms of climate model output, these changes are more robust than changes in climate variability. By concentrating on changes in climate means, the full impacts of climate change on biological and human systems are probably being seriously underestimated. Here, we briefly review the possible impacts of changes in climate variability and the frequency of extreme events on biological and food systems, with a focus on the developing world. We present new analysis that tentatively links increases in climate variability with increasing food insecurity in the future. We consider the ways in which people deal with climate variability and extremes and how they may adapt in the future. Key knowledge and data gaps are highlighted. These include the timing and interactions of different climatic stresses on plant growth and development, particularly at higher temperatures, and the impacts on crops, livestock and farming systems of changes in climate variability and extreme events on pest-weed-disease complexes. We highlight the need to reframe research questions in such a way that they can provide decision makers throughout the food system with actionable answers, and the need for investment in climate and environmental monitoring. Improved understanding of the full range of impacts of climate change on biological and food systems is a critical step in being able to address effectively the effects of climate variability and extreme events on human vulnerability and food security, particularly in agriculturally based developing countries facing the challenge of having to feed rapidly growing populations in the coming decades. © 2014 The Authors. Global Change Biology published by John Wiley & Sons Ltd.

  14. Climate variability and vulnerability to climate change: a review

    Science.gov (United States)

    Thornton, Philip K; Ericksen, Polly J; Herrero, Mario; Challinor, Andrew J

    2014-01-01

    The focus of the great majority of climate change impact studies is on changes in mean climate. In terms of climate model output, these changes are more robust than changes in climate variability. By concentrating on changes in climate means, the full impacts of climate change on biological and human systems are probably being seriously underestimated. Here, we briefly review the possible impacts of changes in climate variability and the frequency of extreme events on biological and food systems, with a focus on the developing world. We present new analysis that tentatively links increases in climate variability with increasing food insecurity in the future. We consider the ways in which people deal with climate variability and extremes and how they may adapt in the future. Key knowledge and data gaps are highlighted. These include the timing and interactions of different climatic stresses on plant growth and development, particularly at higher temperatures, and the impacts on crops, livestock and farming systems of changes in climate variability and extreme events on pest-weed-disease complexes. We highlight the need to reframe research questions in such a way that they can provide decision makers throughout the food system with actionable answers, and the need for investment in climate and environmental monitoring. Improved understanding of the full range of impacts of climate change on biological and food systems is a critical step in being able to address effectively the effects of climate variability and extreme events on human vulnerability and food security, particularly in agriculturally based developing countries facing the challenge of having to feed rapidly growing populations in the coming decades. PMID:24668802

  15. Rapid NH changes in NGC 4151

    Science.gov (United States)

    Puccetti, S.; Fiore, F.; Risaliti, G.; Capalbi, M.; Elvis, M.; Nicastro, F.

    2007-05-01

    We have analysed the two longest (elapsed time >~3 d) BeppoSAX observations of the X-ray brightest Seyfert galaxy, NGC 4151, to search for spectral variability on time-scales from a few tens of kiloseconds to years. We found in both cases highly significant spectral variability below ~6 keV down to the shortest time-scales investigated. These variations can be naturally explained in terms of variations in the low energy cut-off due to obscuring matter along the line of sight. If the cut-off is modelled by two neutral absorption components, one fully covering the source and the second covering only a fraction of the source, the shortest time-scale of variability of a few days constrains the location of the obscuring matter to within 3.4 × 104 Schwarzschild radii from the central X-ray source. This is consistent with the distance of the broad emission-line region, as inferred from reverberation mapping, and difficult to reconcile with the parsec scale dusty molecular torus of Krolik & Begelman. We have also explored a more complex absorption structure, namely the presence of an ionized absorber. Although the behaviour of the ionization parameter is nicely consistent with the expectations, the results are not completely satisfactory from the statistical point of view. The overall absorption during the 2001 December observation is lower than in all other historical observations with similar 2-10 keV flux. This suggests that absorption variability plays a crucial role in the observed flux variability of this source.

  16. Volcanoes drive climate variability by emitting ozone weeks before eruptions, by forming lower stratospheric aerosols, by causing sustained ozone depletion, and by causing rapid changes in regional ozone concentrations affecting temperature and pressure differences driving atmospheric oscillations

    Science.gov (United States)

    Ward, P. L.

    2016-12-01

    Total column ozone observed by satellite on February 19, 2010, increased 75% in a plume from Eyjafjallajökull volcano in southern Iceland eastward past Novaya Zemlya, extending laterally from northern Greenland to southern Norway (http://youtu.be/wJFZcPEfoR4). Contemporaneous ground deformation and rapidly increasing numbers of earthquakes imply magma began rising from a sill 4-6 km below the volcano, erupting a month later. Whether the ozone formed from the magma or from very hot gases rising through cracks in the ground is unclear. On February 20-22, 1991, similar increases in ozone were observed north of Pinatubo volcano before its initial eruption on April 2 (http://youtu.be/5y1PU2Qu3ag). Annual average total column ozone during the year of most moderate to large explosive volcanic eruptions since routine observations of ozone began in 1927 has been substantially higher than normal. Increased total column ozone absorbs more solar ultraviolet-B radiation, warming the ozone layer and cooling Earth. Most major volcanic eruptions form sulfuric-acid aerosols in the lower part of the ozone layer providing aqueous surfaces on which heterogeneous chemical reactions enhance ozone depletion. Within a year, aerosol droplets grew large enough to reflect and scatter high-frequency solar radiation, cooling Earth 0.5oC for 2-3 years. Temperature anomalies in the northern hemisphere rose 0.7oC in 28 years from 1970 to 1998 (HadCRUT4), while annual average ozone at Arosa dropped 27 DU because of manufactured CFC gases. Beginning in August 2014, temperature anomalies in the northern hemisphere rose another 0.6oC in less than two years apparently because of the 6-month eruption of Bárðarbunga volcano in central Iceland, the highest rate of basaltic lava extrusion since 1783. Large extrusions of basaltic lava are typically contemporaneous with the greatest periods of warming throughout Earth history. Ozone concentrations at Arosa change by season typically from 370 DU during

  17. Climate Change and Variability in Ghana: Stocktaking

    Directory of Open Access Journals (Sweden)

    Felix A. Asante

    2014-12-01

    Full Text Available This paper provides a holistic literature review of climate change and variability in Ghana by examining the impact and projections of climate change and variability in various sectors (agricultural, health and energy and its implication on ecology, land use, poverty and welfare. The findings suggest that there is a projected high temperature and low rainfall in the years 2020, 2050 and 2080, and desertification is estimated to be proceeding at a rate of 20,000 hectares per annum. Sea-surface temperatures will increase in Ghana’s waters and this will have drastic effects on fishery. There will be a reduction in the suitability of weather within the current cocoa-growing areas in Ghana by 2050 and an increase evapotranspiration of the cocoa trees. Furthermore, rice and rooted crops (especially cassava production are expected to be low. Hydropower generation is also at risk and there will be an increase in the incidence rate of measles, diarrheal cases, guinea worm infestation, malaria, cholera, cerebro-spinal meningitis and other water related diseases due to the current climate projections and variability. These negative impacts of climate change and variability worsens the plight of the poor, who are mostly women and children.

  18. Millennium Ecosystem Assessment: MA Rapid Land Cover Change

    Data.gov (United States)

    National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Rapid Land Cover Change provides data and information on global and regional land cover change in raster format for...

  19. Rapid climate change: lessons from the recent geological past

    Science.gov (United States)

    Holmes, Jonathan; Lowe, John; Wolff, Eric; Srokosz, Meric

    2011-12-01

    Rapid, or abrupt, climate change is regarded as a change in the climate system to a new state following the crossing of a threshold. It generally occurs at a rate exceeding that of the change in the underlying cause. Episodes of rapid climate change abound in the recent geological past (defined here as the interval between the last glacial maximum, dated to approximately 20,000 years ago, and the present). Rapid climate changes are known to have occurred over time periods equal to or even less than a human lifespan: moreover, their effects on the global system are sufficiently large to have had significant societal impacts. The potential for similar events to occur in the future provides an important impetus for investigating the nature and causes of rapid climate change. This paper provides a brief overview of rapid climate change and an introduction to this special issue, which presents results generated by the palaeoclimatic component of the UK Natural Environment Research Council's rapid climate change programme, called RAPID. The papers in the special issue employ palaeoclimatic proxy data-sets obtained from marine, ice core and terrestrial archives to reconstruct rapid climate change during the last glacial cycle, its subsequent termination and the ensuing Holocene interglacial; some papers also report new attempts to match the palaeoclimate data to hypothesised causes through numerical modelling. The results confirm the importance of freshwater forcing in triggering changes in Atlantic meridional overturning circulation (MOC) and the close links between MOC and rapid climate change. While advancing our understanding of these linkages, the RAPID research has highlighted the need for further research in order to elucidate more specific details of the mechanisms involved.

  20. THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: RAPID C iv BROAD ABSORPTION LINE VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Grier, C. J.; Brandt, W. N.; Trump, J. R.; Schneider, D. P. [Department of Astronomy and Astrophysics and Institute for Gravitation and the Cosmos, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Hall, P. B. [Department of Physics and Astronomy, York University, Toronto, ON M3J 1P3 (Canada); Shen, Yue [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Vivek, M.; Dawson, K. S. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Ak, N. Filiz [Faculty of Sciences, Department of Astronomy and Space Sciences, Erciyes University, 38039 Kayseri (Turkey); Chen, Yuguang [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Denney, K. D.; Kochanek, C. S.; Peterson, B. M. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Green, Paul J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Jiang, Linhua [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); McGreer, Ian D. [Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States); Pâris, I. [INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, I-34131 Trieste (Italy); Tao, Charling [Centre de Physique des Particules de Marseille, Aix-Marseille Universite, CNRS /IN2P3, 163, avenue de Luminy, Case 902, F-13288 Marseille Cedex 09 (France); Wood-Vasey, W. M. [PITT PACC, Department of Physics and Astronomy, University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260 (United States); Bizyaev, Dmitry, E-mail: grier@psu.edu [Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM, 88349-0059 (United States); and others

    2015-06-10

    We report the discovery of rapid variations of a high-velocity C iv broad absorption line trough in the quasar SDSS J141007.74+541203.3. This object was intensively observed in 2014 as a part of the Sloan Digital Sky Survey Reverberation Mapping Project, during which 32 epochs of spectroscopy were obtained with the Baryon Oscillation Spectroscopic Survey spectrograph. We observe significant (>4σ) variability in the equivalent width (EW) of the broad (∼4000 km s{sup −1} wide) C iv trough on rest-frame timescales as short as 1.20 days (∼29 hr), the shortest broad absorption line variability timescale yet reported. The EW varied by ∼10% on these short timescales, and by about a factor of two over the duration of the campaign. We evaluate several potential causes of the variability, concluding that the most likely cause is a rapid response to changes in the incident ionizing continuum. If the outflow is at a radius where the recombination rate is higher than the ionization rate, the timescale of variability places a lower limit on the density of the absorbing gas of n{sub e} ≳ 3.9 × 10{sup 5} cm{sup −3}. The broad absorption line variability characteristics of this quasar are consistent with those observed in previous studies of quasars, indicating that such short-term variability may in fact be common and thus can be used to learn about outflow characteristics and contributions to quasar/host-galaxy feedback scenarios.

  1. Are rapid changes in brain elasticity possible?

    Science.gov (United States)

    Parker, K. J.

    2017-09-01

    Elastography of the brain is a topic of clinical and preclinical research, motivated by the potential for viscoelastic measures of the brain to provide sensitive indicators of pathological processes, and to assist in early diagnosis. To date, studies of the normal brain and of those with confirmed neurological disorders have reported a wide range of shear stiffness and shear wave speeds, even within similar categories. A range of factors including the shear wave frequency, and the age of the individual are thought to have a possible influence. However, it may be that short term dynamics within the brain may have an influence on the measured stiffness. This hypothesis is addressed quantitatively using the framework of the microchannel flow model, which derives the tissue stiffness, complex modulus, and shear wave speed as a function of the vascular and fluid network in combination with the elastic matrix that comprise the brain. Transformation rules are applied so that any changes in the fluid channels or the elastic matrix can be mapped to changes in observed elastic properties on a macroscopic scale. The results are preliminary but demonstrate that measureable, time varying changes in brain stiffness are possible simply by accounting for vasodynamic or electrochemical changes in the state of any region of the brain. The value of this preliminary exploration is to identify possible mechanisms and order-of-magnitude changes that may be testable in vivo by specialized protocols.

  2. Water Resource Variability and Climate Change

    Directory of Open Access Journals (Sweden)

    Yingkui Li

    2016-08-01

    Full Text Available A significant challenge posed by changing climates is how water cycling and surficial and subsurface water availability will be affected at global and regional scales. Such alterations are critical as they often lead to increased vulnerability in ecosystems and human society. Understanding specifically how climate change affects water resource variability in different locations is of critical importance to sustainable development in different parts of the world. The papers included in this special issue focus on three broad perspectives associated with water resource variability and climate change. Six papers employ remote sensing, meteorological station-based observational data, and tree-ring records to empirically determine how water resources have been changing over historical time periods. Eight of the contributions focus on modeling approaches to determine how known processes are likely to manifest themselves as climate shifts over time. Two others focus on human perceptions and adaptation strategies in the midst of unstable or unsettled water availability. The findings and methods presented in this collection of papers provide important contributions to the increased study and awareness of climate change on water resources.

  3. Rapidly changing flows in the Earth's core

    DEFF Research Database (Denmark)

    Olsen, Nils; Mandea, M.

    2008-01-01

    recently been used to investigate small-scale core flow(3,4), but no advantage has yet been taken of the improved temporal resolution, partly because the filtering effect of the electrically conducting mantle was assumed to mask short-period magnetic variations(5). Here we show that changes in the magnetic...

  4. Temporal variability of live (stained benthic foraminiferal faunas in a river-dominated shelf – Faunal response to rapid changes of the river influence (Rhône prodelta, NW Mediterranean

    Directory of Open Access Journals (Sweden)

    E. Legrand

    2012-04-01

    Full Text Available In the context of the French research project CHACCRA (Climate and Human-induced Alterations in Carbon Cycling at the River-seA connection, living (rose Bengal-stained benthic foraminifera were investigated at two stations (24 and 67 m depth in the Rhône prodelta (NW Mediterranean, Gulf of Lions. The aim of this study was to precise the response of benthic foraminiferal faunas to temporal changes of the Rhône River inputs (e.g. organic and terrigeneous material. Each site was sampled in April 2007, September 2007, May 2008 and December 2008, permitting to observe foraminiferal faunas of the 63–150 and >150 μm size fractions under a wide range of environmental conditions. Obvious variations in foraminiferal faunal composition were observed during the four investigated periods at the shallowest Station A located in the close vicinity of the Rhône River mouth. After major Rhône River flood events, different colonisation stages were observed with foraminiferal faunas responding with an opportunistic strategy few days to weeks after the creation of a peculiar sedimentary environment (Leptohalysis scottii, May 2008 or high organic matter supplies (Ammonia tepida, December 2008. Under more stable conditions, relatively diverse and equilibrated faunas grew in the sediments. Species benefited from noticeable input of riverine phytodetritus to the sediment during spring bloom conditions (April 2007; e.g. Bolivina dilatata, Nonionella stella, Stainforthia fusiformis, or high amounts of still bio-available organic matter under more oligotrophic conditions (September 2007; e.g. Ammonia tepida, Psammosphaera fusca. The reduced influence of the Rhône River input at the farther Station N led to less contrasted environmental conditions during the four sampling periods, and so to less obvious variations in foraminiferal faunal composition. During reduced riverine influence (i.e. low Rhône discharge, species able to feed on fresh phytodetritus (e

  5. Social psychiatry in a rapidly changing world

    Directory of Open Access Journals (Sweden)

    Thomas K. J. Craig

    2016-01-01

    Full Text Available Many societies around the world are experiencing a period of unprecedented change in traditional social roles and customs. Globalisation has contributed to materialism and a me-first individualism that heightens awareness of income inequality that itself is one of the most robust markers of unhappiness in society. Ever increasing urbanisation has driven an erosion of large ‘joint’ family arrangements to be replaced by smaller and relatively isolated nuclear families and single parent living. Mass migration has unmasked deep seated fear and prejudice towards the outsider in society. These global changes are fertile ground for the social conditions that have long been known to be risks for mental illness – poverty, poor quality child care, social isolation and the active discrimination and exclusion of the alien, the physically disabled and mentally ill. While there is little we can do to reverse global change, there is much a social psychiatrist can do to mitigate the effect, ensuring his/her voice is added to other calls for reducing discriminatory practice, promoting evidence-based social interventions such as parenting advice and peer support and ensuring that the success of a treatment is measured not just in terms of symptomatic improvement but in whether it results in an outcome that is valued by the patient.

  6. Kepler Observations of Rapid Optical Variability in Active Galactic Nuclei

    Science.gov (United States)

    Mushotzky, R. F.; Edelson, R.; Baumgartner, W. H.; Gandhi, P.

    2012-01-01

    Over three quarters in 2010 - 2011, Kepler monitored optical emission from four active galactic nuclei (AGN) with approx 30 min sampling, > 90% duty cycle and approx law slopes of -2.6 to -3.3, much steeper than typically seen in the X-rays. We find evidence that individual AGN exhibit intrinsically different PSD slopes. The steep PSD fits are a challenge to recent AGN variability models but seem consistent with first order MRI theoretical calculations of accretion disk fluctuations.

  7. Rotation periods and photometric variability of rapidly rotating ultracool dwarfs

    Science.gov (United States)

    Miles-Páez, P. A.; Pallé, E.; Zapatero Osorio, M. R.

    2017-12-01

    We used the optical and near-infrared imagers located on the Liverpool, the IAC80, and the William Herschel telescopes to monitor 18 M7-L9.5 dwarfs with the objective of measuring their rotation periods. We achieved accuracies typically in the range ±1.5-28 mmag by means of differential photometry, which allowed us to detect photometric variability at the 2σ level in the 50 per cent of the sample. We also detected periodic modulation with periods in the interval 1.5-4.4 h in 9 out of 18 dwarfs that we attribute to rotation. Our variability detections were combined with data from the literature; we found that 65 ± 18 per cent of M7-L3.5 dwarfs with v sin I ≥ 30 km s-1 exhibit photometric variability with typical amplitudes ≤20 mmag in the I band. For those targets and field ultracool dwarfs with measurements of v sin I and rotation period we derived the expected inclination angle of their rotation axis, and found that those with v sin I ≥ 30 km s-1 are more likely to have inclinations ≳40 deg. In addition, we used these rotation periods and others from the literature to study the likely relationship between rotation and linear polarization in dusty ultracool dwarfs. We found a correlation between short rotation periods and large values of linear polarization at optical and near-infrared wavelengths.

  8. Models for Very Rapid High-Energy -Ray Variability in Blazars

    Indian Academy of Sciences (India)

    We present a family of models for rapid -ray variability in blazars based on a two-component jet. Fast variability occurs when relativistic electron–positron pairs interact with small-scale perturbations in the inner jet. These perturbations are produced by Kelvin–Helmholtz instabilities. We fit the minute-scale strong variability ...

  9. Rethinking species’ ability to cope with rapid climate change

    DEFF Research Database (Denmark)

    Hof, Christian; Levinsky, Irina; Bastos Araujo, Miguel

    2011-01-01

    Ongoing climate change is assumed to be exceptional because of its unprecedented velocity. However, new geophysical research suggests that dramatic climatic changes during the Late Pleistocene occurred extremely rapid, over just a few years. These abrupt climatic changes may have been even faster...... species' ability to cope with climate change, and that lessons must be learned for modelling future impacts of climate change on species....

  10. Ecosystem stewardship: sustainability strategies for a rapidly changing planet

    Science.gov (United States)

    F. Stuart Chapin; Stephen R. Carpenter; Gary P. Kofinas; Carl Folke; Nick Abel; William C. Clark; Per Olsson; D. Mark Stafford Smith; Brian Walker; Oran R. Young; Fikret Berkes; Reinette Biggs; J. Morgan Grove; Rosamond L. Naylor; Evelyn Pinkerton; Will Steffen; Frederick J. Swanson

    2010-01-01

    Ecosystem stewardship is an action-oriented framework intended to foster the social-ecological sustainability of a rapidly changing planet. Recent developments identify three strategies that make optimal use of current understanding in an environment of inevitable uncertainty and abrupt change: reducing the magnitude of, and exposure and sensitivity to, known stresses...

  11. Managing in the rapidly changing context of higher education: a ...

    African Journals Online (AJOL)

    Higher education is one of the most rapidly changing sectors of our society. Besides the rate of change in the sector there are also, as seen from the continuous media coverage, a number of universities and technikons in some form of financial or leadership crisis. Over the past years one of the main reasons given for these ...

  12. Changing precipitation in western Europe, climate change or natural variability?

    Science.gov (United States)

    Aalbers, Emma; Lenderink, Geert; van Meijgaard, Erik; van den Hurk, Bart

    2017-04-01

    Multi-model RCM-GCM ensembles provide high resolution climate projections, valuable for among others climate impact assessment studies. While the application of multiple models (both GCMs and RCMs) provides a certain robustness with respect to model uncertainty, the interpretation of differences between ensemble members - the combined result of model uncertainty and natural variability of the climate system - is not straightforward. Natural variability is intrinsic to the climate system, and a potentially large source of uncertainty in climate change projections, especially for projections on the local to regional scale. To quantify the natural variability and get a robust estimate of the forced climate change response (given a certain model and forcing scenario), large ensembles of climate model simulations of the same model provide essential information. While for global climate models (GCMs) a number of such large single model ensembles exists and have been analyzed, for regional climate models (RCMs) the number and size of single model ensembles is limited, and the predictability of the forced climate response at the local to regional scale is still rather uncertain. We present a regional downscaling of a 16-member single model ensemble over western Europe and the Alps at a resolution of 0.11 degrees (˜12km), similar to the highest resolution EURO-CORDEX simulations. This 16-member ensemble was generated by the GCM EC-EARTH, which was downscaled with the RCM RACMO for the period 1951-2100. This single model ensemble has been investigated in terms of the ensemble mean response (our estimate of the forced climate response), as well as the difference between the ensemble members, which measures natural variability. We focus on the response in seasonal mean and extreme precipitation (seasonal maxima and extremes with a return period up to 20 years) for the near to far future. For most precipitation indices we can reliably determine the climate change signal, given

  13. Population growth is a variable open to change

    Science.gov (United States)

    Potts, M.

    2016-12-01

    The absolute number of people and the rate of population growth have an impact on climate mitigation, adaptation and possible conflict. Half the pregnancies in the US are unintended. Robust quantitative evidence from California demonstrates that improving access to family planning is the single most cost-effective way of mitigating our carbon footprint. Globally, there are 80 million unintended pregnancies annually. Many non-evidence barriers deprive women of the information and means required to separate sex from childbearing. Between 1960 and 1990, meeting the need for family planning led to a rapid fall in family size in much of Asia. Since 1990, funding for family planning has collapsed and fertility decline has stalled. The UN projects that by 2100 global population will increase by 3.8 billion (equal to world population in 1975). 80% of this growth will be in Africa. Studies project that climate change will undermine crop yields in parts of Africa, especially the Sahel. A high ratio of young males to the rest of the population is a risk factor in conflict. Today, only 1% of overseas assistance is allocated to family planning. Based on analysis of the past, doubling that investment would accelerate fertility decline, facilitating climate mitigation and adaptation, and possibly reducing conflict. Population and family planning were pushed off the international agenda by unacceptably and tragic episodes of coercion in China and India. However, there is compelling data that when voluntary family planning is widely available then family size can fall rapidly, as occurred in the Islamic Republic of Iran, where fertility fell more rapidly than in any other country in history. Family planning is listening to what women want not telling people want to do. Population growth is a variable open to change in a human rights framework. Population and family planning are variables relevant to the scientific agenda of the AGU.

  14. Interpersonal variability in timing strategy and temporal accuracy in rapid interception task with variable time-to-contact.

    Science.gov (United States)

    Ijiri, Tetsuya; Shinya, Masahiro; Nakazawa, Kimitaka

    2015-01-01

    In rapid interceptive actions such as hitting a baseball, cricket ball or tennis ball, ball speed varies between trials, and players have to compensate the time lag by controlling the moment of movement onset and movement duration. Previous studies have found that these two variables can flexibly co-vary and are robustly influenced by target speed (i.e. velocity-coupling effect: faster movement for faster target). However, some studies reported an interpersonal variability in the timing control strategy and the relationship between the strategy and temporal accuracy in rapid interception is unclear. We used a baseball-simulated rapid interceptive task to assess this issue. Under relatively easy time constraints, there was a large interpersonal variability, and participants were distinctively divided into two groups: those who mainly modulated their movement duration and those who mainly controlled their movement onset. When the time constraint became severe, the second strategy shifted to the first strategy in most of the second group participants. In the both cases, being able to mainly control movement onset resulted in higher temporal accuracy. These results suggest that minimising the velocity-coupling effect is an important factor to achieve high temporal accuracy in rapid interception.

  15. Canopy interception variability in changing climate

    Science.gov (United States)

    Kalicz, Péter; Herceg, András; Kisfaludi, Balázs; Csáki, Péter; Gribovszki, Zoltán

    2017-04-01

    Tree canopies play a rather important role in forest hydrology. They intercept significant amounts of precipitation and evaporate back into the atmosphere during and after precipitation event. This process determines the net intake of forest soils and so important factor of hydrological processes in forested catchments. Average amount of interception loss is determined by the storage capacity of tree canopies and the rainfall distribution. Canopy storage capacity depends on several factors. It shows strong correlation with the leaf area index (LAI). Some equations are available to quantify this dependence. LAI shows significant variability both spatial and temporal scale. There are several methods to derive LAI from remote sensed data which helps to follow changes of it. In this study MODIS sensor based LAI time series are used to estimate changes of the storage capacity. Rainfall distribution derived from the FORESEE database which is developed for climate change related impact studies in the Carpathian Basin. It contains observation based precipitation data for the past and uses bias correction method for the climate projections. In this study a site based estimation is outworked for the Sopron Hills area. Sopron Hills is located at the eastern foothills of the Alps in Hungary. The study site, namely Hidegvíz Valley experimental catchment, is located in the central valley of the Sopron Hills. Long-term interception measurements are available in several forest sites in Hidegvíz Valley. With the combination of the ground based observations, MODIS LAI datasets a simple function is developed to describe the average yearly variations in canopy storage. Interception measurements and the CREMAP evapotranspiration data help to calibrate a simple interception loss equation based on Merriam's work. Based on these equation and the FORESEE bias corrected precipitation data an estimation is outworked for better understanding of the feedback of forest crown on hydrological

  16. Rapid Communication: v= 2 seniority changing transitions in yrast 3 ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 89; Issue 5. Rapid Communication: Δ υ = 2 seniority changing transitions in yrast 3 − states and B ( E 3 ) systematics of Sn isotopes. BHOOMIKA MAHESHWARI SWATI GARG ASHOK KUMAR JAIN. Research Article Volume 89 Issue 5 November 2017 Article ID 75 ...

  17. Rapid Communication: seniority changing transitions in yrast states ...

    Indian Academy of Sciences (India)

    Bhoomika Maheshwari

    2017-10-26

    Oct 26, 2017 ... Rapid Communication: v = 2 seniority changing transitions in yrast 3− states and B(E3) systematics of Sn isotopes. BHOOMIKA MAHESHWARI1,∗. , SWATI GARG2 and ASHOK KUMAR JAIN2. 1Department of Physics, Banasthali University, Banasthali 304 022, India. 2Department of Physics, IIT Roorkee, ...

  18. Variability of tropical cyclone rapid intensification in the North Atlantic and its relationship with climate variations

    Science.gov (United States)

    Wang, Chunzai; Wang, Xidong; Weisberg, Robert H.; Black, Michael L.

    2017-02-01

    The paper uses observational data from 1950 to 2014 to investigate rapid intensification (RI) variability of tropical cyclones (TCs) in the North Atlantic and its relationships with large-scale climate variations. RI is defined as a TC intensity increase of at least 15.4 m/s (30 knots) in 24 h. The seasonal RI distribution follows the seasonal TC distribution, with the highest number in September. Although an RI event can occur anywhere over the tropical North Atlantic (TNA), there are three regions of maximum RI occurrence: (1) the western TNA of 12°N-18°N and 60°W-45°W, (2) the Gulf of Mexico and the western Caribbean Sea, and (3) the open ocean southeast and east of Florida. RI events also show a minimum value in the eastern Caribbean Sea north of South America—a place called a hurricane graveyard due to atmospheric divergence and subsidence. On longer time scales, RI displays both interannual and multidecadal variability, but RI does not show a long-term trend due to global warming. The top three climate indices showing high correlations with RI are the June-November ENSO and Atlantic warm pool indices, and the January-March North Atlantic oscillation index. It is found that variabilities of vertical wind shear and TC heat potential are important for TC RI in the hurricane main development region, whereas relative humidity at 500 hPa is the main factor responsible for TC RI in the eastern TNA. However, the large-scale oceanic and atmospheric variables analyzed in this study do not show an important role in TC RI in the Gulf of Mexico and the open ocean southeast and east of Florida. This suggests that other factors such as small-scale changes of oceanic and atmospheric variables or TC internal processes may be responsible for TC RI in these two regions. Additionally, the analyses indicate that large-scale atmospheric and oceanic variables are not critical to TC genesis and formation; however, once a tropical depression forms, large-scale climate

  19. Variability of tropical cyclone rapid intensification in the North Atlantic and its relationship with climate variations

    Science.gov (United States)

    Wang, Chunzai; Wang, Xidong; Weisberg, Robert H.; Black, Michael L.

    2017-12-01

    The paper uses observational data from 1950 to 2014 to investigate rapid intensification (RI) variability of tropical cyclones (TCs) in the North Atlantic and its relationships with large-scale climate variations. RI is defined as a TC intensity increase of at least 15.4 m/s (30 knots) in 24 h. The seasonal RI distribution follows the seasonal TC distribution, with the highest number in September. Although an RI event can occur anywhere over the tropical North Atlantic (TNA), there are three regions of maximum RI occurrence: (1) the western TNA of 12°N-18°N and 60°W-45°W, (2) the Gulf of Mexico and the western Caribbean Sea, and (3) the open ocean southeast and east of Florida. RI events also show a minimum value in the eastern Caribbean Sea north of South America—a place called a hurricane graveyard due to atmospheric divergence and subsidence. On longer time scales, RI displays both interannual and multidecadal variability, but RI does not show a long-term trend due to global warming. The top three climate indices showing high correlations with RI are the June-November ENSO and Atlantic warm pool indices, and the January-March North Atlantic oscillation index. It is found that variabilities of vertical wind shear and TC heat potential are important for TC RI in the hurricane main development region, whereas relative humidity at 500 hPa is the main factor responsible for TC RI in the eastern TNA. However, the large-scale oceanic and atmospheric variables analyzed in this study do not show an important role in TC RI in the Gulf of Mexico and the open ocean southeast and east of Florida. This suggests that other factors such as small-scale changes of oceanic and atmospheric variables or TC internal processes may be responsible for TC RI in these two regions. Additionally, the analyses indicate that large-scale atmospheric and oceanic variables are not critical to TC genesis and formation; however, once a tropical depression forms, large-scale climate

  20. Geoengineering and the Risk of Rapid Climate Change

    Science.gov (United States)

    Ross, A. J.; Matthews, D.

    2008-12-01

    Many scientists have proposed that geoengineering could be used to artificially cool the planet as a means of reducing CO2-induced climate warming. However, several recent studies have shown some of the potential risks of geoengineering, including negative impacts on stratospheric ozone, the hydrologic cycle and the possibility of rapid climate change in the case of abrupt failure, or rapid decommissioning of geoengineering technology. In this study, we have emulated a geoengineering scenario in the MAGICC climate model, by counteracting the radiative forcing from greenhouse gases. We have used a hypothetical scenario of business-as-usual greenhouse gas emissions, in which geoengineering is implemented at the year 2020, and is removed abruptly after 40 years. By varying the climate sensitivity of the MAGICC model, and using previously published estimates of climate sensitivity likelihoods, we are able to derive a probabilistic prediction of the rate of temperature change following the removal of geoengineering. In a simulation without geoengineering (considering only the A1B AIM emissions scenario) the maximum annual rate of temperature change (in the highest climate sensitivity simulation) was 0.5° C per decade. In the geoengineering simulations the maximum annual rate of temperature change, occurring in the year after geoengineering was stopped, varied from 0.22° C per decade for a climate sensitivity of 0.5° C to nearly 8° C per decade for a climate sensitivity of 10° C. The most likely maximum rate of change (corresponding to a climate sensitivity of 2.5° C) was just over 5° C per decade. There is a 99.8 percent probability that the rate of temperature change following the stoppage of geoengineering in this scenario would exceed 3° C per decade. This risk of rapid climate change associated with the use of planetary-scale geoengineering is highly relevant to discussion of climate policies aimed at avoiding "dangerous anthropogenic interference" in the

  1. Climate variability and vulnerability to climate change: a review

    OpenAIRE

    Thornton, Philip K; Ericksen, Polly J.; Herrero, Mario; Challinor, Andrew J

    2014-01-01

    The focus of the great majority of climate change impact studies is on changes in mean climate. In terms of climate model output, these changes are more robust than changes in climate variability. By concentrating on changes in climate means, the full impacts of climate change on biological and human systems are probably being seriously underestimated. Here, we briefly review the possible impacts of changes in climate variability and the frequency of extreme events on biological and food syst...

  2. Major rapid weight loss induces changes in cardiac repolarization

    DEFF Research Database (Denmark)

    Vedel-Larsen, Esben; Iepsen, Eva Pers Winning; Lundgren, Julie

    2016-01-01

    analysis has been suggested as a more sensitive method to identify changes in cardiac repolarization. We examined the effect of a major and rapid weight loss on T-wave morphology. METHODS AND RESULTS: Twenty-six individuals had electrocardiograms (ECG) taken before and after eight weeks of weight loss...... intervention along with plasma measurements of fasting glucose, HbA1c, and potassium. For assessment of cardiac repolarization changes, T-wave Morphology Combination Score (MCS) and ECG intervals: RR, PR, QT, QTcF (Fridericia-corrected QT-interval), and QRS duration were derived. The participants lost......A1c (pMonitoring of MCS during calorie restriction makes it possible to detect repolarization changes with higher discriminative power than the QT-interval during major rapid weight...

  3. Rapid climate variability during warm and cold periods in polar regions and Europe

    DEFF Research Database (Denmark)

    Masson-Delmotte, V.; Landais, A.; Combourieu-Nebout, N.

    2005-01-01

    rapid cooling recorded during the Holocene in Greenland ice cores and in Ammersee, Germany. The rate of warming during previous warmer interglacial periods is estimated from polar ice cores to 1.5 °C per millennium, without abrupt changes. Climate change expected for the 21st century should however......Typical rapid climate events punctuating the last glacial period in Greenland, Europe and Antarctica are compared to two rapid events occurring under warmer conditions: (i) Dansgaard-Oeschger event 25, the first abrupt warming occurring during last glacial inception; (ii) 8.2 ka BP event, the only...

  4. Rapid climate change and society: assessing responses and thresholds.

    Science.gov (United States)

    Niemeyer, Simon; Petts, Judith; Hobson, Kersty

    2005-12-01

    Assessing the social risks associated with climate change requires an understanding of how humans will respond because it affects how well societies will adapt. In the case of rapid or dangerous climate change, of particular interest is the potential for these responses to cross thresholds beyond which they become maladaptive. To explore the possibility of such thresholds, a series of climate change scenarios were presented to U.K. participants whose subjective responses were recorded via interviews and surveyed using Q methodology. The results indicate an initially adaptive response to climate warming followed by a shift to maladaptation as the magnitude of change increases. Beyond this threshold, trust in collective action and institutions was diminished, negatively impacting adaptive capacity. Climate cooling invoked a qualitatively different response, although this may be a product of individuals being primed for warming because it has dominated public discourse. The climate change scenarios used in this research are severe by climatological standards. In reality, the observed responses might occur at a lower rate of change. Whatever the case, analysis of subjectivity has revealed potential for maladaptive human responses, constituting a dangerous or rapid climate threshold within the social sphere.

  5. The Chinese experience of rapid modernization: sociocultural changes, psychological consequences?

    Directory of Open Access Journals (Sweden)

    Jiahong eSun

    2016-04-01

    Full Text Available Mainland China has undergone profound changes dating back to the nineteenth century, including a contemporary period of rapid modernization that began in the 1980s. The result has been dramatic social, cultural, and economic shifts impacting the daily lives of Chinese people. In this paper, we explore the psychological implications of sociocultural transformation in China, emphasizing two central themes. First, rising individualism: findings from social and developmental psychology suggest that China’s rapid development has been accompanied by ever-increasing adherence to individualistic values. Second, rising rates of depression: findings from psychiatric epidemiology point to increasing prevalence of depression over this same time period, particularly in rural settings. We argue that links between sociocultural and psychological shifts in China can be usefully studied through a cultural psychology lens, emphasizing the mutual constitution of culture, mind, and brain. In particular, we note that the link between social change, individualism, and rising mental illness deserves careful attention. Our review suggests that shifting values and socialization practices shape emotion norms of concealment and display, with implications for depressive symptom presentation. The challenge comes with interpretation. Increasing prevalence rates of depression may indeed be a general response to the rapidity of sociocultural change, or a specific consequence of rising individualism—but may also result from increasingly ‘Western’ patterns of symptom presentation, or improvements in diagnostic practice. We conclude by considering the challenges posed to standard universal models of psychological phenomena.

  6. The Chinese Experience of Rapid Modernization: Sociocultural Changes, Psychological Consequences?

    Science.gov (United States)

    Sun, Jiahong; Ryder, Andrew G.

    2016-01-01

    Mainland China has undergone profound changes dating back to the nineteenth century, including a contemporary period of rapid modernization that began in the 1980s. The result has been dramatic social, cultural, and economic shifts impacting the daily lives of Chinese people. In this paper, we explore the psychological implications of sociocultural transformation in China, emphasizing two central themes. First, rising individualism: findings from social and developmental psychology suggest that China’s rapid development has been accompanied by ever-increasing adherence to individualistic values. Second, rising rates of depression: findings from psychiatric epidemiology point to increasing prevalence of depression over this same time period, particularly in rural settings. We argue that links between sociocultural and psychological shifts in China can be usefully studied through a cultural psychology lens, emphasizing the mutual constitution of culture, mind, and brain. In particular, we note that the link between social change, individualism, and rising mental illness deserves careful attention. Our review suggests that shifting values and socialization practices shape emotion norms of concealment and display, with implications for depressive symptom presentation. The challenge comes with interpretation. Increasing prevalence rates of depression may indeed be a general response to the rapidity of sociocultural change, or a specific consequence of rising individualism—but may also result from increasingly ‘Western’ patterns of symptom presentation, or improvements in diagnostic practice. We conclude by considering the challenges posed to standard universal models of psychological phenomena. PMID:27092093

  7. Comparing farmers' perception of climate change and variability with ...

    African Journals Online (AJOL)

    Perception of climate change and variability supported by local knowledge has helped to advance understanding of climate change and its impacts on agricultural land-use systems. This study compares farmers' perception of climate change and variability in four communities of the Upper East Region of Ghana. Using a ...

  8. Intrinsic Electromagnetic Variability in Celestial Objects Containing Rapidly Spinning Black Holes

    Science.gov (United States)

    Zhang, Fan

    2016-02-01

    Analytical studies have raised the concern that a mysterious expulsion of magnetic field lines by a rapidly spinning black hole (dubbed the black hole Meissner effect) would shut down the Blandford-Znajek process and quench the jets of active galactic nuclei and microquasars. This effect is, however, not seen observationally or in numerical simulations. Previous attempts at reconciling the predictions with observations have proposed several mechanisms to evade the Meissner effect. In this paper, we identify a new evasion mechanism and discuss its observational significance. Specifically, we show that the breakdown of stationarity is sufficient to remove the expulsion of the magnetic field at all multipole orders, and that the associated temporal variation is likely turbulent because of the existence of efficient mechanisms for sharing energy across different modes. Such an intrinsic (as opposed to being driven externally by, e.g., changes in the accretion rate) variability of the electromagnetic field can produce the recorded linear correlation between microvariability amplitudes and mean fluxes, help create magnetic randomness and seed sheared magnetic loops in jets, and lead to a better theoretical fit to the X-ray microvariability power spectral density.

  9. Integrated ocean management as a strategy to meet rapid climate change: the Norwegian case.

    Science.gov (United States)

    Hoel, Alf Håkon; Olsen, Erik

    2012-02-01

    The prospects of rapid climate change and the potential existence of tipping points in marine ecosystems where nonlinear change may result from them being overstepped, raises the question of strategies for coping with ecosystem change. There is broad agreement that the combined forces of climate change, pollution and increasing economic activities necessitates more comprehensive approaches to oceans management, centering on the concept of ecosystem-based oceans management. This article addresses the Norwegian experience in introducing integrated, ecosystem-based oceans management, emphasizing how climate change, seen as a major long-term driver of change in ecosystems, is addressed in management plans. Understanding the direct effects of climate variability and change on ecosystems and indirect effects on human activities is essential for adaptive planning to be useful in the long-term management of the marine environment.

  10. Effects of climatic variability and change

    Science.gov (United States)

    Michael G. Ryan; James M. Vose

    2012-01-01

    Climate profoundly shapes forests. Forest species composition, productivity, availability of goods and services, disturbance regimes, and location on the landscape are all regulated by climate. Much research attention has focused on the problem of projecting the response of forests to changing climate, elevated atmospheric carbon dioxide (CO2)...

  11. Potential impacts of climate change and variability on groundwater ...

    African Journals Online (AJOL)

    Aizebeokhai

    This paper attempts to assess the potential impacts of climate change and variability on groundwater resources availability and sustainability in Nigeria. Key words: Climate change, variability, hydrological systems, groundwater, potential impacts, vulnerability. INTRODUCTION. All life on Earth, water and energy resources, ...

  12. RAPID CHANGES IN SOCIETY, TECHNOLOGY ,ECONOMY AND PUBLIC SERVICE INSTITUTIONS

    Directory of Open Access Journals (Sweden)

    Tirthendu Bagchi

    2017-03-01

    Full Text Available Current paper has the purpose to analyze the statement by Drucker (1985 that rapid changes in today’s society, technology, and economy in general are simultaneously a great threat to public-service institutions and even greater opportunity. The statement by Drucker will be analyzed  particularly with context of post offices that what are they going through these days or have gone through. Finally, some recommendations will be made for USPS based on the findings of the analysis..

  13. Changes in heart rate variability with age.

    Science.gov (United States)

    Reardon, M; Malik, M

    1996-11-01

    Depressed heart rate variability (HRV) after a myocardial infarction is associated with increased mortality. This is thought to be due to reduced parasympathetic activity and heightened sympathetic activity. Aging is associated with depressed HRV, but little is known of the affect of aging on parasympathetic activity. This study examined 56 healthy subjects (age range 40-102 years; 39 women). None had a history of heart disease or were on medication that would affect cardiac function. All had normal resting ECGs, normal heart size on chest X ray, and normal electrolytes. In all subjects, 24-hour Holter recordings were performed and used to measure HRV. In particular, the study examined the affect of age on HRV triangular index, which gives an estimate of overall HRV, and on RMSSD (square root of the mean squared differences of successive normal-to-normal RR intervals), which gives an estimate of short-term components of HRV and is thought to reflect the overall extent of vagal modulations of heart rates. Both these parameters were compared in patients younger and older than 70 years. Each recording lasted at least 17 hours; the majority of recordings were longer than 20 hours. There was a significant decrease in HRV triangular index with age (r = -0.4, P 70 years compared with those < 70 years (38.0 +/- 9.3 vs 31.0 +/- 11, respectively, P < 0.02). There was no significant difference in RMSSD between the two age groups (26.7 +/- 8.2 ms vs 28.4 +/- 11.3 ms, respectively, P = NS). Thus, the study concludes that aging reduces the global measure of HRV and may reflect reduced responsiveness of autonomic activity to external environmental stimuli with age. However, the time-domain short-term components of HRV are not affected by age and, therefore, the fast and presumably vagal modulations of heart rate appear to be maintained.

  14. Models for Very Rapid High-Energy γ-Ray Variability in Blazars G. E. ...

    Indian Academy of Sciences (India)

    Some of the ideas and models proposed then to explain the origin of phenomenon ... 2012), producing a rapid succession of short γ-ray flares, as ... origin. Finally, we show a wide variety of light curves that are attainable in our model by changing within a reasonable range of values, the parameters related to different.

  15. Rapid treatment-induced brain changes in pediatric CRPS.

    Science.gov (United States)

    Erpelding, Nathalie; Simons, Laura; Lebel, Alyssa; Serrano, Paul; Pielech, Melissa; Prabhu, Sanjay; Becerra, Lino; Borsook, David

    2016-03-01

    To date, brain structure and function changes in children with complex regional pain syndrome (CRPS) as a result of disease and treatment remain unknown. Here, we investigated (a) gray matter (GM) differences between patients with CRPS and healthy controls and (b) GM and functional connectivity (FC) changes in patients following intensive interdisciplinary psychophysical pain treatment. Twenty-three patients (13 females, 9 males; average age ± SD = 13.3 ± 2.5 years) and 21 healthy sex- and age-matched controls underwent magnetic resonance imaging. Compared to controls, patients had reduced GM in the primary motor cortex, premotor cortex, supplementary motor area, midcingulate cortex, orbitofrontal cortex, dorsolateral prefrontal cortex (dlPFC), posterior cingulate cortex, precuneus, basal ganglia, thalamus, and hippocampus. Following treatment, patients had increased GM in the dlPFC, thalamus, basal ganglia, amygdala, and hippocampus, and enhanced FC between the dlPFC and the periaqueductal gray, two regions involved in descending pain modulation. Accordingly, our results provide novel evidence for GM abnormalities in sensory, motor, emotional, cognitive, and pain modulatory regions in children with CRPS. Furthermore, this is the first study to demonstrate rapid treatment-induced GM and FC changes in areas implicated in sensation, emotion, cognition, and pain modulation.

  16. Rapid Treatment-Induced Brain Changes in Pediatric CRPS

    Science.gov (United States)

    Erpelding, Nathalie; Simons, Laura; Lebel, Alyssa; Serrano, Paul; Pielech, Melissa; Prabhu, Sanjay; Becerra, Lino; Borsook, David

    2014-01-01

    To date, brain structure and function changes in children with complex regional pain syndrome (CRPS) as a result of disease and treatment remain unknown. Here, we investigated (a) gray matter (GM) differences between patients with CRPS and healthy controls and (b) GM and functional connectivity (FC) changes in patients following intensive interdisciplinary psychophysical pain treatment. Twenty-three patients (13 females, 9 males; average age ± SD = 13.3 ± 2.5 years) and 21 healthy sex-and age-matched controls underwent magnetic resonance imaging. Compared to controls, patients had reduced GM in the primary motor cortex, premotor cortex, supplementary motor area, midcingulate cortex, orbitofrontal cortex, dorsolateral prefrontal cortex (dlPFC), posterior cingulate cortex, precuneus, basal ganglia, thalamus, and hippocampus. Following treatment, patients had increased GM in the dlPFC, thalamus, basal ganglia, amygdala, and hippocampus, and enhanced FC between the dlPFC and the periaqueductal gray (PAG), two regions involved in descending pain modulation. Accordingly, our results provide novel evidence for GM abnormalities in sensory, motor, emotional, cognitive, and pain modulatory regions in children with CRPS. Furthermore, this is the first study to demonstrate rapid treatment-induced GM and FC changes in areas implicated in sensation, emotion, cognition, and pain modulation. PMID:25515312

  17. Mobile work: Ergonomics in a rapidly changing work environment.

    Science.gov (United States)

    Honan, Meg

    2015-01-01

    Places of work have been completely transformed by innovations in mobile work tools and ever-present access to internet data. This article characterizes use patterns and provides preliminary considerations for productive and comfortable use of common mobile devices. Two surveys described trends in mobile work. In the first, ergonomics professionals who oversee programs reported common mobile devices, their users and what data is accessed. The second, an end user survey, explored common activities performed on mobile devices, duration of use and locations where mobile work is common. The survey results provide a baseline data point for the status of mobile work in early 2014. Research indicates that additional risks have been introduced to the neck, thumbs and hands when using mobile devices. Possible trends regarding device use and work locations emerge. Intervention studies provide some direction for the practitioner. Practical strategies are outlined to reduce exposure intensity and duration. Contemporary mobile work presents tremendous change and opportunity for ergonomists and researchers to keep pace with fitting the changing models of work to the person. Continued research is needed on current mobile device use patterns to better understand ergonomic risk exposure in this rapidly changing realm.

  18. Effects of rapid changes in temperature on two estuarine crustaceans

    Energy Technology Data Exchange (ETDEWEB)

    Burton, D.T.; Capizzi, T.P.; Margrey, S.L.; Wakefield, W.W.

    1981-01-01

    Weight specific oxygen consumption (Q/sub O/sub 2// patterns of the amphipod, Gammarus sp. (acclimated to 5/sup 0/, 15/sup 0/ and 25/sup 0/ C) and of juvenile blue crabs, Callinectes sapidus (15/sup 0/ and 25/sup 0/ C) were used to evaluate the potential effect of exposure to rapid temperature changes simulating once-through power plant pumped entrainment. Amphipods at all acclimation temperatures and blue crabs at 15/sup 0/ C responded to the temperature changes by increasing Q/sub O/sub 2// above pre-exposure levels after the thermal increase and then returning to pre-exposure levels. The response was judged to be a normal physiological compensation response, not a thermal stress response, as suggested by some investigators. Significant differences were found among seasonal Q/sub O/sub 2// patterns in both species; Q/sub O/sub 2// increased with increasing acclimation temperature. However, no seasonal stress effects were found as a result of exposure to the temperature changes. This implies that the effects of ..delta..T's up to 10(/sup 0/C) from power plants of this design should have no significant impact on these organisms.

  19. Rapid genomic DNA changes in allotetraploid fish hybrids.

    Science.gov (United States)

    Wang, J; Ye, L H; Liu, Q Z; Peng, L Y; Liu, W; Yi, X G; Wang, Y D; Xiao, J; Xu, K; Hu, F Z; Ren, L; Tao, M; Zhang, C; Liu, Y; Hong, Y H; Liu, S J

    2015-06-01

    Rapid genomic change has been demonstrated in several allopolyploid plant systems; however, few studies focused on animals. We addressed this issue using an allotetraploid lineage (4nAT) of freshwater fish originally derived from the interspecific hybridization of red crucian carp (Carassius auratus red var., ♀, 2n=100) × common carp (Cyprinus carpio L., ♂, 2n=100). We constructed a bacterial artificial chromosome (BAC) library from allotetraploid hybrids in the 20th generation (F20) and sequenced 14 BAC clones representing a total of 592.126 kb, identified 11 functional genes and estimated the guanine-cytosine content (37.10%) and the proportion of repetitive elements (17.46%). The analysis of intron evolution using nine orthologous genes across a number of selected fish species detected a gain of 39 introns and a loss of 30 introns in the 4nAT lineage. A comparative study based on seven functional genes among 4nAT, diploid F1 hybrids (2nF1) (first generation of hybrids) and their original parents revealed that both hybrid types (2nF1 and 4nAT) not only inherited genomic DNA from their parents, but also demonstrated rapid genomic DNA changes (homoeologous recombination, parental DNA fragments loss and formation of novel genes). However, 4nAT presented more genomic variations compared with their parents than 2nF1. Interestingly, novel gene fragments were found for the iqca1 gene in both hybrid types. This study provided a preliminary genomic characterization of allotetraploid F20 hybrids and revealed evolutionary and functional genomic significance of allopolyploid animals.

  20. Impacts of climate variability and change on beekeeping productivity ...

    African Journals Online (AJOL)

    Nonetheless beekeepers face serious constraints and interventions are needed to strengthen the capacity of beekeepers to adapt through integrating climate services with available indigenous knowledge and local practices. Key Words: Beekeeping, climate change and variability, vulnerability and adaptation ...

  1. CLIMATE CHANGE, VARIABILITY AND SUSTAINABLE AGRICULTURE IN ZIMBABWE'S RURAL COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Gukurume Simbarashe

    2013-02-01

    Full Text Available This article explores the impact of climate change and variability on agricultural productivity in the communal area of Bikita. The article further examines the adaptation and mitigation strategies devised by farmers to deal with the vagaries of climate change and variability. The sustainability of these is also interrogated in this article. This study juxtaposed qualitative and quantitative methodologies albeit with more bias on the former. A total of 40 farmers were sampled for unstructured interviews and focus group discussions. This article argues that the adverse impacts of climate change and variability are felt heavily by the poor communal farmers who are directly dependent on agriculture for livelihood. From the study, some of the widely reported signs of climate variability in Bikita included late and unpredictable rains, high temperatures (heat waves, successive drought, shortening rainfall seasons and seasonal changes in the timing of rainfall. The paper argues that climate change has compounded the vulnerability of peasant farmers in the drought - prone district of Bikita plunging them into food insecurity and abject poverty. It emerged in the study that some of effects of climate variability felt by communal farmers in Bikita included failure of crops, death of livestock and low crop yields, all of which have led to declining agricultural productivity. Findings in this study however established that communal farmers have not been passive victims of the vagaries of climate change and variability. They have rationally responded to it through various adaptation and mitigation strategies both individually and collectively.

  2. Pheromones-based sexual selection in a rapidly changing world.

    Science.gov (United States)

    Henneken, Jessica; Jones, Therésa M

    2017-12-01

    Insects utilise chemical cues for a range of different purposes and the complexity and degree of specificity of these signals is arguably unparalleled in the animal kingdom. Chemical signals are particularly important for insect reproduction and the selective pressures driving their evolution and maintenance have been the subject of previous reviews. However, the world in which chemical cues evolved and are maintained is changing at an unprecedented rate. How (or indeed whether) chemical signals used in sexual selection will respond is largely unknown. Here, we explore how recent increases in urbanisation and associated anthropogenic impacts may affect how chemical signals are produced and perceived. We focus on four anthropomorphic influences which have the potential to interact with pheromone-mediated sexual selection processes; climatic temperature shifts, exposure to chemical pollutants, the presence of artificial light at night and nutrient availability. Our aim is to provide a broad overview of key areas where the rapidly changing environment of the future might specifically affect pheromones utilised in sexual selection. Copyright © 2017. Published by Elsevier Inc.

  3. Rapid Middle Eocene temperature change in western North America

    Science.gov (United States)

    Methner, Katharina; Mulch, Andreas; Fiebig, Jens; Wacker, Ulrike; Gerdes, Axel; Graham, Stephan A.; Chamberlain, C. Page

    2016-09-01

    Eocene hyperthermals are among the most enigmatic phenomena of Cenozoic climate dynamics. These hyperthermals represent temperature extremes superimposed on an already warm Eocene climate and dramatically affected the marine and terrestrial biosphere, yet our knowledge of temperature and rainfall in continental interiors is still rather limited. We present stable isotope (δ18O) and clumped isotope temperature (Δ47) records from a middle Eocene (41 to 40 Ma) high-elevation mammal fossil locality in the North American continental interior (Montana, USA). Δ47 paleotemperatures of soil carbonates delineate a rapid +9/-11 °C temperature excursion in the paleosol record. Δ47 temperatures progressively increase from 23 °C ± 3 °C to peak temperatures of 32 °C ± 3 °C and subsequently drop by 11 °C. This hyperthermal event in the middle Eocene is accompanied by low δ18O values and reduced pedogenic carbonate concentrations in paleosols. Based on laser ablation U/Pb geochronology of paleosol carbonates in combination with magnetostratigraphy, biostratigraphy, stable isotope, and Δ47 evidence, we suggest that this pronounced warming event reflects the Middle Eocene Climatic Optimum (MECO) in western North America. The terrestrial expression of northern hemisphere MECO in western North America appears to be characterized by warmer and wetter (sub-humid) conditions, compared to the post-MECO phase. Large and rapid shifts in δ18O values of precipitation and pedogenic CaCO3 contents parallel temperature changes, indicating the profound impact of the MECO on atmospheric circulation and rainfall patterns in the western North American continental interior during this transient warming event.

  4. The Intensification of Global and Regional Climate Variability and Change

    Science.gov (United States)

    Weaver, S. J.

    2015-12-01

    Recent evidence from the IPCC and National Climate Assessment reports indicate that extreme climate events are increasing in many regions of the world. Interestingly, the nature and causes of the changes in extremes may be expressed differently for the global and regional scales, and also amongst climate variables (e.g., precipitation and temperature). For instance, over the last several decades the temperature probability density function on the global scale exhibits a mean shift to the warmer side, as opposed to a change in it's variability. Conversely, the interannual variability of precipitation is intensifying on the regional scale, especially over the U.S. during spring. Although the statistical characteristics of the temperature and precipitation changes may have a varied expression they both contribute to the potential for increases in extreme events. The causes and physical mechanisms for the intensification of mean global temperature and regional precipitation variability are explored using observationally constrained datasets and non-traditional climate model approaches.

  5. Evaluation of immediate soft tissue changes after rapid maxillary expansion

    Directory of Open Access Journals (Sweden)

    Ki Beom Kim

    2012-10-01

    Full Text Available OBJECTIVE: To evaluate immediate soft tissue changes following rapid maxillary expansion (RME in growing patients, using cone beam computed tomography (CBCT. METHODS: Twenty-three consecutive patients (10 male, 13 female treated by RME were selected. Patients were scanned using CBCT prior to placement of the rapid maxillary expander (T0, then immediately following full activation of the appliance (T1. Defined landmarks were then located on the pre- and post-treatment orientated images. Change in landmark position from pre- to post-treatment was then measured. In addition to landmarks, 10 direct measures were made to determine distance change without regard to direction to measure soft tissue change of the lips. RESULTS: Significant transverse expansion was measured on most soft tissue landmark locations. All the measures made showed significant change in the lip position with a lengthening of the vertical dimension of the upper lip, and a generalized decrease of anterior-posterior thickness of both the upper and lower lips. CONCLUSIONS: Significant changes in the soft tissue do occur with RME treatment. There is a transverse widening of the midface, and a thinning of the lips.OBJETIVO: avaliar as mudanças imediatas no tecido mole após a expansão rápida da maxila (ERM em pacientes em fase de crescimento, usando tomografia computadorizada de feixe cônico (TCFC. MÉTODOS: vinte e três pacientes (10 do sexo masculino e 13 do feminino tratados com ERM foram selecionados. Os pacientes foram escaneados por TCFC antes da implantação do expansor maxilar (T0 e imediatamente após a completa ativação do aparelho (T1. Pontos cefalométricos definidos foram localizados nas imagens pré- e pós-tratamento. As mudanças de posição desses pontos do pré- para o pós-tratamento foram, então, analisadas. Adicionalmente aos pontos, 10 medições diretas foram realizadas para determinar a mudança nas distâncias - independentemente da direção - nos

  6. Human relations with soil are changing rapidly: SSSA's new Work Group on Soil Change

    Science.gov (United States)

    Humanity has rapidly become Earth’s chief agent of soil change, and geologists have named the epoch in which we live the Anthropocene, due to the global scale of human impact on the environment, including soil. In response to the increasing influence of humans on soil processes, the disciplines of ...

  7. Impacts of climate change, variability and adaptation strategies on ...

    African Journals Online (AJOL)

    hope&shola

    deal with impacts of climate change and variability. Further, development initiatives at community level in semi arid areas should put more emphasis on water harvesting to ensure water storage for crops and livestock. Key words: Agriculture production, climate change, Kamenyanga village, Manyoni District, rainfall, Singida.

  8. Potential impacts of climate change and variability on groundwater ...

    African Journals Online (AJOL)

    Aizebeokhai

    uncertainties in the characterisation of climate change induced groundwater impacts due largely to multi-scale local and ... Key words: Climate change, climate variability, hydrological systems, groundwater resources, potential impacts, vulnerability. ..... except where surface layers are of poor permeability and afford some ...

  9. Perceptions and adaptation to climate change and variability by ...

    African Journals Online (AJOL)

    Kenya comprises of 83% arid and semi-arid land mainly suited to extensive livestock production. Communities living in the semi-arid areas have been affected by serious effects of climate change and variability. A study was carried out to evaluate farmer perceptions and adaptation to climate change in Naro Moru and ...

  10. Climate Change and Variability: Implications for Household Food ...

    African Journals Online (AJOL)

    Daniel

    Ethiopia is one of the most vulnerable countries of the world to the impacts of climate change and variability. The impact is even stronger in pastoral areas of the country. However, studies on the actual climate change dynamics and its effect on food security at local and household levels are limited. The present study took ...

  11. Variable stiffness mechanisms of dual parameters changing magnetorheological fluid devices

    Science.gov (United States)

    Deng, Huaxia; Wang, Mingxian; Han, Guanghui; Zhang, Jin; Ma, Mengchao; Zhong, Xiang; Yu, Liandong

    2017-12-01

    Magnetorheological fluid (MRF) dampers are widely used as the variable damping devices in the semi-active vibration control system. In order to further improve the vibration reduction performance, a variable stiffness MRF damper with two chambers and two springs has been proposed recently. According to the test results, both of the damping and stiffness of the device can be controllable by changing the applied current independently. However, the mechanisms of variable stiffness for this device are still not clear. In this paper, the force transmissions of the parts of the variable stiffness MRF damper are analyzed, which reveals the variable stiffness mechanisms of dual parameters changing MRF devices. There are three stages for the variable stiffness MRF damper due to the friction and the yield of MR fluid. These stages can be controlled by the applied current of the different chambers, which changes the equivalent stiffness of the device. The proposed modelling of the device is verified by simulations and tests. In addition, the relationships between the equivalent stiffness and the parameters of the device are derived, which provide the design guidance for the variable stiffness MRF dampers.

  12. Ecological and evolutionary impacts of changing climatic variability.

    Science.gov (United States)

    Vázquez, Diego P; Gianoli, Ernesto; Morris, William F; Bozinovic, Francisco

    2017-02-01

    While average temperature is likely to increase in most locations on Earth, many places will simultaneously experience higher variability in temperature, precipitation, and other climate variables. Although ecologists and evolutionary biologists widely recognize the potential impacts of changes in average climatic conditions, relatively little attention has been paid to the potential impacts of changes in climatic variability and extremes. We review the evidence on the impacts of increased climatic variability and extremes on physiological, ecological and evolutionary processes at multiple levels of biological organization, from individuals to populations and communities. Our review indicates that climatic variability can have profound influences on biological processes at multiple scales of organization. Responses to increased climatic variability and extremes are likely to be complex and cannot always be generalized, although our conceptual and methodological toolboxes allow us to make informed predictions about the likely consequences of such climatic changes. We conclude that climatic variability represents an important component of climate that deserves further attention. © 2015 Cambridge Philosophical Society.

  13. Impact of internal variability on projections of Sahel precipitation change

    Science.gov (United States)

    Monerie, Paul-Arthur; Sanchez-Gomez, Emilia; Pohl, Benjamin; Robson, Jon; Dong, Buwen

    2017-11-01

    The impact of the increase of greenhouse gases on Sahelian precipitation is very uncertain in both its spatial pattern and magnitude. In particular, the relative importance of internal variability versus external forcings depends on the time horizon considered in the climate projection. In this study we address the respective roles of the internal climate variability versus external forcings on Sahelian precipitation by using the data from the CESM Large Ensemble Project, which consists of a 40 member ensemble performed with the CESM1-CAM5 coupled model for the period 1920–2100. We show that CESM1-CAM5 is able to simulate the mean and interannual variability of Sahel precipitation, and is representative of a CMIP5 ensemble of simulations (i.e. it simulates the same pattern of precipitation change along with equivalent magnitude and seasonal cycle changes as the CMIP5 ensemble mean). However, CESM1-CAM5 underestimates the long-term decadal variability in Sahel precipitation. For short-term (2010–2049) and mid-term (2030–2069) projections the simulated internal variability component is able to obscure the projected impact of the external forcing. For long-term (2060–2099) projections external forcing induced change becomes stronger than simulated internal variability. Precipitation changes are found to be more robust over the central Sahel than over the western Sahel, where climate change effects struggle to emerge. Ten (thirty) members are needed to separate the 10 year averaged forced response from climate internal variability response in the western Sahel for a long-term (short-term) horizon. Over the central Sahel two members (ten members) are needed for a long-term (short-term) horizon.

  14. Optical Defocus Rapidly Changes Choroidal Thickness in Schoolchildren.

    Directory of Open Access Journals (Sweden)

    Danyang Wang

    Full Text Available The current study aimed to examine the short-term choroidal response to optical defocus in schoolchildren. Myopic schoolchildren aged 8-16 were randomly allocated to control group (CG, myopic defocus group (MDG and hyperopic defocus group (HDG (n = 17 per group. Children in MDG and HDG received additional +3D and -3D lenses, respectively, to their full corrections on the right eyes. Full correction was given to their left eyes, and on both eyes in the CG. Axial length (AXL and subfoveal choroidal thickness (SFChT were then measured by spectral domain optical coherence tomography. Children wore their group-specific correction for 2 hours after which any existing optical defocus was removed, and subjects wore full corrections for another 2 hours. Both the AXL and SFChT were recorded hourly for 4 hours. The mean refraction of all subjects was -3.41 ± 0.37D (± SEM. SFChT thinned when exposed to hyperopic defocus for 2 hours but less thinning was observed in response to myopic defocus compared to the control group (p < 0.05, two-way ANOVA. Removal of optical defocus significantly decreased SFChT in the MDG and significantly increased SFChT in the HDG after 1 and 2 hours (mean percentage change at 2-hour; control vs. hyperopic defocus vs. myopic defocus; -0.33 ± 0.59% vs. 3.04 ± 0.60% vs. -1.34 ± 0.74%, p < 0.01. Our results showed short-term exposure to myopic defocus induced relative choroidal thickening while hyperopic defocus led to choroidal thinning in children. This rapid and reversible choroidal response may be an important clinical parameter in gauging retinal response to optical defocus in human myopia.

  15. Rapid emergence of climate change in environmental drivers of marine ecosystems

    Science.gov (United States)

    Henson, Stephanie A.; Beaulieu, Claudie; Ilyina, Tatiana; John, Jasmin G.; Long, Matthew; Séférian, Roland; Tjiputra, Jerry; Sarmiento, Jorge L.

    2017-03-01

    Climate change is expected to modify ecological responses in the ocean, with the potential for important effects on the ecosystem services provided to humankind. Here we address the question of how rapidly multiple drivers of marine ecosystem change develop in the future ocean. By analysing an ensemble of models we find that, within the next 15 years, the climate change-driven trends in multiple ecosystem drivers emerge from the background of natural variability in 55% of the ocean and propagate rapidly to encompass 86% of the ocean by 2050 under a `business-as-usual' scenario. However, we also demonstrate that the exposure of marine ecosystems to climate change-induced stress can be drastically reduced via climate mitigation measures; with mitigation, the proportion of ocean susceptible to multiple drivers within the next 15 years is reduced to 34%. Mitigation slows the pace at which multiple drivers emerge, allowing an additional 20 years for adaptation in marine ecological and socio-economic systems alike.

  16. International trade and the adaptation to climate change and variability

    OpenAIRE

    Stephan, Gunter; Schenker, Oliver

    2012-01-01

    This paper has three messages mainly, which are observed in a simple model of climate change, international trade and regional adaptation. First, trade can be viewed as a kind of adaptation to climate change and variability, as trade can help to reduce direct impacts of global climate change on a region’s welfare. In particular, the less affected and the richer nations are, the more they can profit from moderating the impacts of global climate change through trade. Second, if regions are rich...

  17. Climate variability and change: a perspective from the oceania region

    Science.gov (United States)

    Beer, Tom

    2014-12-01

    This brief review identifies seven key science questions in relation to climate variability and change and examines recent research within the Australian and Pacific context: 1. How do the key processes controlling climate variability and predictability operate? 2. What are the nature and causes of regional climate anomalies, past variations in regional climate and extreme weather events and how will they change in the future? 3. How can we provide improved seasonal-to-interannual climate predictions? 4. What are the best projection methods? 5. What are the sea-level changes now and in the future; and how will these impact the coasts? 6. How to have significant benefits on climate service delivery and environmental management? 7. What are the best methods for assessing climate change risks, vulnerability and adaptation options?

  18. Mid-infrared Variability of Changing-look AGNs

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Zhenfeng; Wang, Tinggui; Jiang, Ning; Yang, Chenwei; Peng, Bo [CAS Key Laboratory for Researches in Galaxies and Cosmology, University of Sciences and Technology of China, Hefei, Anhui 230026 (China); Yan, Lin [Caltech Optical Observatories, Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Dou, Liming, E-mail: shengzf@mail.ustc.edu.cn, E-mail: twang@ustc.edu.cn [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)

    2017-09-01

    It is known that some active galactic nuclei (AGNs) transit from Type 1 to Type 2 or vice versa. There are two explanations for the so-called changing-look AGNs: one is the dramatic change of the obscuration along the line of sight, and the other is the variation of accretion rate. In this Letter, we report the detection of large amplitude variations in the mid-infrared luminosity during the transitions in 10 changing-look AGNs using the Wide-field Infrared Survey Explorer ( WISE ) and newly released Near-Earth Object WISE Reactivation data. The mid-infrared light curves of 10 objects echo the variability in the optical band with a time lag expected for dust reprocessing. The large variability amplitude is inconsistent with the scenario of varying obscuration, rather it supports the scheme of dramatic change in the accretion rate.

  19. Impacts of Climate Variability and Climate Change on the Mangrove ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Impacts of Climate Variability and Climate Change on the Mangrove Ecosystem in Tumbes, Peru. The mangrove ecosystem of Tumbes plays a pivotal role in providing protection against tides, winds and storm surges, and habitat for a number of fish species. The native coastal communities of Tumbes rely on artisanal ...

  20. Effects of temporal changes in climate variables on crop production ...

    African Journals Online (AJOL)

    Climate variability and change have been implicated to have significant impacts on global and regional food production particularly the common stable food crops performance in tropical sub-humid climatic zone. However, the extent and nature of these impacts still remain uncertain. In this study, records of crop yields and ...

  1. Climate change and variability: Smallholder farming communities in ...

    African Journals Online (AJOL)

    Increasing awareness of risks associated with climate change and variability among smallholder farmers is critical in building their capacity to develop the necessary adaptive measures. Using farmer participatory research approaches and formal questionnaire surveys, interaction has been made with >800 farmers in two ...

  2. Women in Physics in a Rapidly Changing China

    Science.gov (United States)

    Wu, Ling-An

    2008-03-01

    Despite the upheavals of the 20th century, physics managed to survive quite well in China, where the first woman president of the American Physical Society was born and bred. During the 1950s as a result of policies that emphasized science and engineering, declared equal rights and equal pay for men and women, and assigned jobs to college graduates irrespective of sex, the number of women in physics increased rapidly, many of whom made notable achievements. Since China's opening up over the last thirty years tremendous changes have taken place, and women now face new opportunities as well as challenges in all aspects of society. Whereas physics used to be regarded as the most elite of the sciences, new fields such as computer science, biotechnology and business are now competing for the best students. Compared with other countries the statistics are not bad; in schools and many physics departments the ratio of women teachers may be 30% or higher, but the numbers drop drastically with rank. Moreover, in some research institutions the ratio of female physicists is actually declining, due to retirement of the older generation and fewer successors. Compulsory retirement for women at an earlier age than for men is also a new factor. Conversely, in recent years the ratio of female graduate students enrolling in physics has increased, even reaching 40% in some universities. However, the reasons for this do not bode well: men are not performing so well as women in entrance exams, while the latter are facing increasing discrimination in employment so they have to seek higher degree qualifications. With the further development of China's economy there will be abundant demand for qualified personnel including women with a physics background. It is imperative to actively support the upcoming generation of women physicists and not lose them in the leaky pipeline. The Chinese Physical Society has taken certain positive steps, such as the recent establishment of the Xie Xi

  3. Rapid Detection of Land Cover Changes Using Crowdsourced Geographic Information: A Case Study of Beijing, China

    Directory of Open Access Journals (Sweden)

    Yuan Meng

    2017-08-01

    Full Text Available Land cover change (LCC detection is a significant component of sustainability research including ecological economics and climate change. Due to the rapid variability of natural environment, effective LCC detection is required to capture sufficient change-related information. Although such information has been available through remotely sensed images, the complicated image processing and classification make it time consuming and labour intensive. In contrast, the freely available crowdsourced geographic information (CGI contains easily interpreted textual information, and thus has the potential to be applied for capturing effective change-related information. Therefore, this paper presents and evaluates a method using CGI for rapid LCC detection. As a case study, Beijing is chosen as the study area, and CGI is applied to monitor LCC information. As one kind of CGI which is generated from commercial Internet maps, points of interest (POIs with detailed textual information are utilised to detect land cover in 2016. Those POIs are first classified into land cover nomenclature based on their textual information. Then, a kernel density approach is proposed to effectively generate land cover regions in 2016. Finally, with GlobeLand30 in 2010 as baseline map, LCC is detected using the post-classification method in the period of 2010–2016 in Beijing. The result shows that an accuracy of 89.20% is achieved with land cover regions generated by POIs, indicating that POIs are reliable for rapid LCC detection. Additionally, an LCC detection comparison is proposed between remotely sensed images and CGI, revealing the advantages of POIs in terms of LCC efficiency. However, due to the uneven distribution, remotely sensed images are still required in areas with few POIs.

  4. Rapid Holocene coastal change revealed by high-resolution micropaleontological analysis, Pamlico Sound, North Carolina, USA

    Science.gov (United States)

    Grand, Pre C.; Culver, S.J.; Mallinson, D.J.; Farrell, K.M.; Corbett, D.R.; Horton, B.P.; Hillier, C.; Riggs, S.R.; Snyder, S.W.; Buzas, M.A.

    2011-01-01

    Foraminiferal analyses of 404 contiguous samples, supported by diatom, lithologic, geochronologic and seismic data, reveal both rapid and gradual Holocene paleoenvironmental changes in an 8.21-m vibracore taken from southern Pamlico Sound, North Carolina. Data record initial flooding of a latest Pleistocene river drainage and the formation of an estuary 9000. yr ago. Estuarine conditions were punctuated by two intervals of marine influence from approximately 4100 to 3700 and 1150 to 500. cal. yr BP. Foraminiferal assemblages in the muddy sand facies that accumulated during these intervals contain many well-preserved benthic foraminiferal species, which occur today in open marine settings as deep as the mid shelf, and significant numbers of well-preserved planktonic foraminifera, some typical of Gulf Stream waters. We postulate that these marine-influenced units resulted from temporary destruction of the southern Outer Banks barrier islands by hurricanes. The second increase in marine influence is coeval with increased rate of sea-level rise and a peak in Atlantic tropical cyclone activity during the Medieval Climate Anomaly. This high-resolution analysis demonstrates the range of environmental variability and the rapidity of coastal change that can result from the interplay of changing climate, sea level and geomorphology in an estuarine setting. ?? 2011 University of Washington.

  5. Rapid method to estimate temperature changes in electronics elements

    Directory of Open Access Journals (Sweden)

    Oborskii G. A., Savel’eva O. S., Shikhireva Yu. V.

    2014-06-01

    Full Text Available Thermal behavior of electronic equipment is the determining factor for performing rapid assessment of the effectiveness of design and operation of the equipment. The assessment method proposed in this article consists in fixation of an infrared video stream from the surface of the device and converting it into a visible flow by means of a thermal imager, splitting it into component colors and their further processing using parabolic transformation. The result of the transformation is the number used as a rapid criterion for estimation of distribution stability of heat in the equipment.

  6. Dynamics of Natural Variability: Ecological Complexity in a Changing World

    Science.gov (United States)

    Falk, D. A.; Savage, M.; Swetnam, T. W.

    2008-12-01

    One of the central challenges in ecology, both theoretical and applied, is understanding how complex systems respond to spatial and temporal variability in their environment. In the context of contemporary and near-term climate variation, this issue can be reframed to ask whether future climate represents "no- analogue" conditions compared to the ecologically relevant past. If future ecosystems operate under climatic and landscape conditions that exceed the envelope of past variability, then it could be argued that our characterizations of how ecosystems functioned in the past may no longer be relevant. In this model, reconstruction of paleoecosystems is still essential for assessing whether systems have exceeded the envelope of past variability, but less useful for predicting future system behavior. This view of the relationship between climate variability and ecosystem function is based largely on statistical characterization of the historical range of variability (HRV) over some temporal and spatial frame of reference. We present an alternative way of thinking about this problem, which focuses on the dynamics of natural systems (DNV) rather than simply their statistical characterization. By emphasizing dynamic interactions among ecosystem components, combined with reconstruction of past environmental variability, we focus attention on the inherently time-varying, nonlinear interaction properties of complex systems. When driving factors exceed the range of past observed values, the ecological response may be correspondingly unfamiliar. This may not mean that the system is operating by different rules, but rather that the functional relationships have shifted to new domains. We provide a series of examples illustrating a DNV perspective, including changes in fire regimes and post-fire vegetation response, insect outbreaks, and species geographic movements in response to changing climates and landscapes. We suggest that an emphasis on dynamic interactions will be

  7. A rapid mitochondrial toxicity assay utilizing rapidly changing cell energy metabolism.

    Science.gov (United States)

    Sanuki, Yosuke; Araki, Tetsuro; Nakazono, Osamu; Tsurui, Kazuyuki

    2017-01-01

    Drug-induced liver injury is a major cause of safety-related drug-marketing withdrawals. Several drugs have been reported to disrupt mitochondrial function, resulting in hepatotoxicity. The development of a simple and effective in vitro assay to identify the potential for mitochondrial toxicity is thus desired to minimize the risk of causing hepatotoxicity and subsequent drug withdrawal. An in vitro test method called the "glucose-galactose" assay is often used in drug development but requires prior-culture of cells over several passages for mitochondrial adaptation, thereby restricting use of the assay. Here, we report a rapid version of this method with the same predictability as the original method. We found that replacing the glucose in the medium with galactose resulted in HepG2 cells immediately shifting their energy metabolism from glycolysis to oxidative phosphorylation due to drastic energy starvation; in addition, the intracellular concentration of ATP was reduced by mitotoxicants when glucose in the medium was replaced with galactose. Using our proposed rapid method, mitochondrial dysfunction in HepG2 cells can be evaluated by drug exposure for one hour without a pre-culture step. This rapid assay for mitochondrial toxicity may be more suitable for high-throughput screening than the original method at an early stage of drug development.

  8. Rapid socio-cultural change and health in the Arctic

    DEFF Research Database (Denmark)

    Bjerregaard, P

    2001-01-01

    health and survival have improved but at the expense of mental health. The incidence of tuberculosis and the infant mortality rate have decreased because of improved socioeconomic conditions and health care. Mental health has deteriorated parallel to the rapid modernization of Greenlandic society...

  9. Comparison between rapid and mixed maxillary expansion through an assessment of arch changes on dental casts.

    Science.gov (United States)

    Grassia, Vincenzo; d'Apuzzo, Fabrizia; Jamilian, Abdolreza; Femiano, Felice; Favero, Lorenzo; Perillo, Letizia

    2015-01-01

    Aim of this retrospective observational study was to compare upper and lower dental changes in patients treated with Rapid Maxillary Expansion (RME) and Mixed Maxillary Expansion (MME), assessed by dental cast analysis. Treatment groups consisted of 42 patients: the RME group (n = 21) consisted of 13 female and 8 male subjects with the mean age of 8.8 years ± 1.37 at T0 and 9.6 years ± 1.45 at T1; the MME group (n = 21) consisted of 12 female and 9 male patients with a mean age of 8.9 years ± 2.34 at T0 and 10.5 years ± 2.08 at T1. The upper and lower arch analysis was performed on four dental bilateral landmarks, on upper and lower casts; also upper and lower arch depths were measured. The groups were compared using independent sample t-test to estimate dental changes in upper and lower arches. Before expansion treatment (T0), the groups were similar for all examined variables (p>0.05). In both RME and MME group, significant increments in all the variables for maxillary and mandibular arch widths were observed after treatment. No significant differences in maxillary and mandibular arch depths were observed at the end of treatment in both groups. An evaluation of the changes after RME and MME (T1) showed statistically significant differences in mandibular arch depth (plip bumper effects" observed in the MME protocol.

  10. Assessment of changes in smile after rapid maxillary expansion

    Directory of Open Access Journals (Sweden)

    Ana Paula Morales Cobra de Carvalho

    2012-10-01

    Full Text Available INTRODUCTION: This study evaluated changes in the smile characteristics of patients with maxillary constriction submitted to rapid maxillary expansion (RME. METHODS: The sample consisted of 81 extraoral photographs of maximum smile of 27 patients with mean age of 10 years, before expansion and 3 and 6 months after fixation of the expanding screw. The photographs were analyzed on the software Cef X 2001, with achievement of the following measurements: Transverse smile area, buccal corridors, exposure of maxillary incisors, gingival exposure of maxillary incisors, smile height, upper and lower lip thickness, smile symmetry and smile arch. Statistical analysis was performed by analysis of variance (ANOVA, at a significance level of 5%. RESULTS: RME promoted statistically significant increase in the transverse smile dimension and exposure of maxillary central and lateral incisors; maintenance of right and left side smile symmetry and of the lack of parallelism between the curvature of the maxillary incisal edges and lower lip border. CONCLUSIONS: RME was beneficial for the smile esthetics with the increase of the transverse smile dimension and exposure of maxillary central and lateral incisors.INTRODUÇÃO: esse estudo avaliou as alterações das características do sorriso de pacientes com atresia maxilar submetidos à expansão rápida da maxila (ERM. MÉTODOS: a amostra consistiu de 81 fotografias extrabucais do sorriso máximo de 27 pacientes, com idade média de 10 anos, antes da expansão e aos três e seis meses após a fixação do parafuso expansor. As análises das fotografias foram realizadas por meio do programa Cef X 2001, e as seguintes medidas foram analisadas: dimensão transversal do sorriso, corredores bucais, quantidade de exposição dos incisivos superiores, exposição gengival dos incisivos superiores, altura do sorriso, espessuras dos lábios superior e inferior, simetria e arco do sorriso. As alterações no sorriso durante

  11. Hydrological change in the Mekong river - flood trends and variability

    Science.gov (United States)

    Delgado, J.; Merz, B.; Apel, H.

    2009-04-01

    Daily average discharge is analyzed in the Mekong river in South East Asia, focusing on tendencies and variability of floods in the 20th century, in an effort to separate unfounded perceptions and empirical evidence. After using trend detection methods usually suggested in literature, other less common approaches to trend analysis were used, namely non-stationary general extreme value (GEV) function and the wavelet power spectrum. Data from four gaging stations downstream of Vientiane, Laos, were used, covering two distinct hydrological regions within the basin. These time series span for over 80 years and are the longest daily discharge time series available in the region. Results from commonly used techniques like Mann-Kendal test and a resampling of linear regression were contradictory and did not show a clear signal. The introduction of the non-stationary GEV allowed to isolate variability from the average trend and to have a more complete view of the changes. Variability could also be translated into significant amplitude changes in a wavelet power spectrum, which confirmed the results of the non-stationary GEV. Overall, results showed increasing likelihood of extreme floods and variability with time, although the mean flood tends to decrease in magnitude. We conclude that the initial absence of clear signals in the hydro- logical time series was a methodological misconception due to over- simplistic models. More adaptive methods, as well as increasingly non-linear hypothesis yield more coherent results.

  12. Rapid N_H changes in NGC 4151

    OpenAIRE

    Puccetti, S.; Fiore, F.; Risaliti, G.; Capalbi, M.; Elvis, M.; Nicastro, F.; .

    2006-01-01

    We have analyzed the two longest (elapsed time > 3 days) BeppoSAX observations of the X-ray brightest Seyfert galaxy, NGC 4151, to search for spectral variability on time-scales from a few tens of ksec to years. We found in both cases highly significant spectral variability below ~ 6 keV down to the shortest time-scales investigated. These variations can be naturally explained in terms of variations in the low energy cut-off due to obscuring matter along the line of sight. If the cut-off is m...

  13. Monitoring variability and changes of the Indonesian Throughflow

    Science.gov (United States)

    Feng, Ming; Wijffels, Susan

    2017-04-01

    The Indonesian Throughflow (ITF) is an important component of the upper cell of the global overturning circulation that provides a low-latitude pathway for warm, fresh waters from the Pacific to enter the Indian Ocean. The IX1 XBT line between the coasts of Australia and Indonesia, initially championed by Gary Meyers, crosses the ITF and has now been in operation for more than 30 years. In this presentation, we review research progresses on the variability and changes of the ITF based on the IX1 XBT data, in memory of Gary's contribution to the Indian Ocean research. The ITF passes across a region that comprises the intersection of two ocean waveguides - those of the equatorial Pacific and equatorial Indian Ocean. The ITF geostrophic transport is stronger during La Niñas and weaker during El Niños. The Indian Ocean wind variability associated with the Indian Ocean Dipole (IOD) in many years offsets the Pacific ENSO influences on the ITF geostrophic transport during the developing and mature phases of El Niño and La Niña, due to the covarying IOD variability with ENSO. The IX1 line reveals the geostrophic ITF decadal and multi-decadal changes: there was a weakening change from the mid-1970s climate regime shift followed by a strengthening trend of about 1 Sv every 10 years over the recent decades. These decadal changes appear mostly due to the ITF responses to decadal variations of the trade winds in the Pacific. Climate models project a weakening trend of the ITF under the global warming, due to the slowdown of the global overturning circulation. The consistent and now multidecadal sampling along IX1 is a precious resource for the climate community and is a testament to the vision and commitment of Gary Meyers to use observations to drive insight into earth's climate variability.

  14. MRI evaluation of body composition changes in wrestlers undergoing rapid weight loss.

    Science.gov (United States)

    Kukidome, T; Shirai, K; Kubo, J; Matsushima, Y; Yanagisawa, O; Homma, T; Aizawa, K

    2008-10-01

    Changes in body composition of college wrestlers undergoing rapid weight reduction were evaluated over time using magnetic resonance imaging (MRI). This study evaluated 12 wrestlers (male, 18-22 years of age) who participated in Japan's 2005 intercollegiate wrestling tournament. For this study, MRI (of the right femoral region and the trunk), as well as measurements of body weight, body fat percentage and body water content, were performed 1 month and 1 week prior to the weigh-in, on the day of the weigh-in, on the day of the match (after the match), and 1 week after the weigh-in. A survey of food and fluid intake was also conducted. Several variables were significantly lower on the day of the weigh-in than one month prior: body weight (pfat (pmuscle, and trunk fat; quadriceps muscle; lower subcutaneous; and food intake (pweight reduction reduced the wrestlers' cross-sectional areas of muscle and fat tissues, which tended to recover through rehydration after the weigh-in. These results suggest that rapid weight reduction of wrestlers induced changes in different regions of the body.

  15. Climate change enhances interannual variability of the Nile river flow

    Science.gov (United States)

    Siam, Mohamed S.; Eltahir, Elfatih A. B.

    2017-04-01

    The human population living in the Nile basin countries is projected to double by 2050, approaching one billion. The increase in water demand associated with this burgeoning population will put significant stress on the available water resources. Potential changes in the flow of the Nile River as a result of climate change may further strain this critical situation. Here, we present empirical evidence from observations and consistent projections from climate model simulations suggesting that the standard deviation describing interannual variability of total Nile flow could increase by 50% (+/-35%) (multi-model ensemble mean +/- 1 standard deviation) in the twenty-first century compared to the twentieth century. We attribute the relatively large change in interannual variability of the Nile flow to projected increases in future occurrences of El Niño and La Niña events and to observed teleconnection between the El Niño-Southern Oscillation and Nile River flow. Adequacy of current water storage capacity and plans for additional storage capacity in the basin will need to be re-evaluated given the projected enhancement of interannual variability in the future flow of the Nile river.

  16. Rapid Spectral Variability of the Symbiotic Star CH Cyg During One Night

    Science.gov (United States)

    Mikayilov, Kh. M.; Rustamov, B. N.; Alakbarov, I. A.; Rustamova, A. B.

    2017-06-01

    During one night (15.07.2015), within 6 hours 14 echelle spectrograms of this star were obtained. It was revealed that the profile of Ha and Hβ lines have two-component emission structure with a central absorption, parameters which vary from spectrum to spectrum during the night. The intensity of blue emission component (V) have been changed strongly during the night: the value of ratio of intensities of violet and red components (V/R) of line Hα decreased from 0:93 to 0:49 in the beginning and then increased to a value of 0.97. The synchronous variations of values of V/R for the Hα and Hβ lines have been revealed. The parameters of blue emission components of Hα and of line Hel λ5876 Å are correlated. We propose that revealed by us the rapid spectral changes in the spectrum of the star CH Cyg could be connected with a flickering in the optical brightness of the star that is typical for the active phase of this system.

  17. Influence of internal variability on population exposure to hydroclimatic changes

    Science.gov (United States)

    Mankin, Justin S.; Viviroli, Daniel; Mekonnen, Mesfin M.; Hoekstra, Arjen Y.; Horton, Radley M.; E Smerdon, Jason; Diffenbaugh, Noah S.

    2017-04-01

    Future freshwater supply, human water demand, and people’s exposure to water stress are subject to multiple sources of uncertainty, including unknown future pathways of fossil fuel and water consumption, and ‘irreducible’ uncertainty arising from internal climate system variability. Such internal variability can conceal forced hydroclimatic changes on multi-decadal timescales and near-continental spatial-scales. Using three projections of population growth, a large ensemble from a single Earth system model, and assuming stationary per capita water consumption, we quantify the likelihoods of future population exposure to increased hydroclimatic deficits, which we define as the average duration and magnitude by which evapotranspiration exceeds precipitation in a basin. We calculate that by 2060, ∽31%-35% of the global population will be exposed to >50% probability of hydroclimatic deficit increases that exceed existing hydrological storage, with up to 9% of people exposed to >90% probability. However, internal variability, which is an irreducible uncertainty in climate model predictions that is under-sampled in water resource projections, creates substantial uncertainty in predicted exposure: ∽86%-91% of people will reside where irreducible uncertainty spans the potential for both increases and decreases in sub-annual water deficits. In one population scenario, changes in exposure to large hydroclimate deficits vary from -3% to +6% of global population, a range arising entirely from internal variability. The uncertainty in risk arising from irreducible uncertainty in the precise pattern of hydroclimatic change, which is typically conflated with other uncertainties in projections, is critical for climate risk management that seeks to optimize adaptations that are robust to the full set of potential real-world outcomes.

  18. Policy options to respond to rapid climate change

    NARCIS (Netherlands)

    Swart, R.J.; Marinova, N.A.; Bakker, S.; Tilburg, van X.

    2009-01-01

    Ongoing research on climate change indicates that we cannot rule out the possibility of extreme climatic changes, beyond current IPCC scenarios. The thinking about policy responses to address these risks is still in its infancy. This study explores the possibilities for responding to extreme

  19. Drought variability and change across the Iberian Peninsula

    Science.gov (United States)

    Coll, J. R.; Aguilar, E.; Ashcroft, L.

    2017-11-01

    Drought variability and change was assessed across the Iberian Peninsula over more than 100 years expanding through the twentieth century and the first decade of the twenty-first century. Daily temperature and precipitation data from 24 Iberian time series were quality controlled and homogenized to create the Monthly Iberian Temperature and Precipitation Series (MITPS) for the period 1906-2010. The Standardized Precipitation Index (SPI), driven only by precipitation, and the Standardized Precipitation Evapotranspiration Index (SPEI), based on the difference between the precipitation and the reference evapotranspiration (ET0), were computed at annual and seasonal scale to describe the evolution of droughts across time. The results confirmed that a clear temperature increase has occurred over the entire Iberian Peninsula at the annual and seasonal scale, but no significant changes in precipitation accumulated amounts were found. Similar drought variability was provided by the SPI and SPEI, although the SPEI showed greater drought severity and larger surface area affected by drought than SPI from 1980s to 2010 due to the increase in atmospheric evaporative demand caused by increased temperatures. Moreover, a clear drying trend was found by the SPEI for most of the Iberian Peninsula at annual scale and also for spring and summer, although the SPI did not experience significant changes in drought conditions. From the drying trend identified for most of the Iberian Peninsula along the twentieth century, an increase in drought conditions can also be expected for this region in the twenty-first century according to future climate change projections and scenarios.

  20. Changes in Sensory Evoked Responses Coincide with Rapid Improvement in Speech Identification Performance

    Science.gov (United States)

    Alain, Claude; Campeanu, Sandra; Tremblay, Kelly

    2010-01-01

    Perceptual learning is sometimes characterized by rapid improvements in performance within the first hour of training (fast perceptual learning), which may be accompanied by changes in sensory and/or response pathways. Here, we report rapid physiological changes in the human auditory system that coincide with learning during a 1-hour test session…

  1. Changes in nasal volume of patients undergoing rapid maxillary expansion

    OpenAIRE

    Muniz, Renata Da Fonseca Lacerda E; Mario Cappellette Jr.; Daniela Carlini

    2008-01-01

    Os efeitos da disjunção maxilar na resistência nasal e fluxo aéreo têm sido amplamente discutidos na literatura, com controvérsias. Suas indicações esqueléticas e dentárias parecem estar bem claras. Porém, aquelas puramente rinológicas não são justificadas, porque nem sempre resultados positivos são encontrados. Este estudo teve por finalidade avaliar a repercussão da disjunção maxilar ortopédica no aspecto respiratório e rinológico dos pacientes submetidos a esse procedimento.Rapid maxillary...

  2. Rapid response to climate change in a marginal sea.

    Science.gov (United States)

    Schroeder, K; Chiggiato, J; Josey, S A; Borghini, M; Aracri, S; Sparnocchia, S

    2017-06-22

    The Mediterranean Sea is a mid-latitude marginal sea, particularly responsive to climate change as reported by recent studies. The Sicily Channel is a choke point separating the sea in two main basins, the Eastern Mediterranean Sea and the Western Mediterranean Sea. Here, we report and analyse a long-term record (1993-2016) of the thermohaline properties of the Intermediate Water that crosses the Sicily Channel, showing increasing temperature and salinity trends much stronger than those observed at intermediate depths in the global ocean. We investigate the causes of the observed trends and in particular determine the role of a changing climate over the Eastern Mediterranean, where the Intermediate Water is formed. The long-term Sicily record reveals how fast the response to climate change can be in a marginal sea like the Mediterranean Sea compared to the global ocean, and demonstrates the essential role of long time series in the ocean.

  3. Diverse multi-decadal changes in streamflow within a rapidly urbanizing region

    Science.gov (United States)

    Diem, Jeremy E.; Hill, T. Chee; Milligan, Richard A.

    2018-01-01

    The impact of urbanization on streamflow depends on a variety of factors (e.g., climate, initial land cover, inter-basin transfers, water withdrawals, wastewater effluent, etc.). The purpose of this study is to examine trends in streamflow from 1986 to 2015 in a range of watersheds within the rapidly urbanizing Atlanta, GA metropolitan area. This study compares eight watersheds over three decades, while minimizing the influence of inter-annual precipitation variability. Population and land-cover data were used to analyze changes over approximately twenty years within the watersheds. Precipitation totals for the watersheds were estimated using precipitation totals at nearby weather stations. Multiple streamflow variables, such as annual streamflow, frequencies of high-flow days (HFDs), flashiness, and precipitation-adjusted streamflow, for the eight streams were calculated using daily streamflow data. Variables were tested for significant trends from 1986 to 2015 and significant differences between 1986-2000 and 2001-2015. Flashiness increased for all streams without municipal water withdrawals, and the four watersheds with the largest increase in developed land had significant increases in flashiness. Significant positive trends in precipitation-adjusted mean annual streamflow and HFDs occurred for the two watersheds (Big Creek and Suwanee Creek) that experienced the largest increases in development, and these were the only watersheds that went from majority forest land in 1986 to majority developed land in 2015. With a disproportionate increase in HFD occurrence during summer, Big Creek and Suwannee Creek also had a reduction in intra-annual variability of HFD occurrence. Watersheds that were already substantially developed at the beginning of the period and did not have wastewater discharge had declining streamflow. The most urbanized watershed (Peachtree Creek) had a significant decrease in streamflow, and a possible cause of the decrease was increasing

  4. Rapid millennial-scale vegetation changes in the tropical Andes

    NARCIS (Netherlands)

    Urrego, D.H.; Hooghiemstra, H.; Rama-Corredor, O.; Martrat, B.; Grimalt, J.O.; Thompson, L.

    2015-01-01

    We compare eight pollen records reflecting climatic and environmental change from the tropical Andes. Our analysis focuses on the last 50 ka, with particular emphasis on the Pleistocene to Holocene transition. We explore ecological grouping and downcore ordination results as two approaches for

  5. Bird mercury concentrations change rapidly as chicks age: Toxicological risk is highest at hatching and fledging.

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.

    2011-01-01

    Toxicological risk of methylmercury exposure to juvenile birds is complex due to the highly transient nature of mercury concentrations as chicks age. We examined total mercury and methylmercury concentrations in blood, liver, kidney, muscle, and feathers of 111 Forster's tern (Sterna forsteri), 69 black-necked stilt (Himantopus mexicanus), and 43 American avocet (Recurvirostra americana) chicks as they aged from hatching through postfledging at wetlands that had either low or high mercury contamination in San Francisco Bay, California. For each waterbird species, internal tissue, and wetland, total mercury and methylmercury concentrations changed rapidly as chicks aged and exhibited a quadratic, U-shaped pattern from hatching through postfledging. Mercury concentrations were highest immediately after hatching, due to maternally deposited mercury in eggs, then rapidly declined as chicks aged and diluted their mercury body burden through growth in size and mercury depuration into growing feathers. Mercury concentrations then increased during fledging when mass gain and feather growth slowed, while chicks continued to acquire dietary mercury. In contrast to mercury in internal tissues, mercury concentrations in chick feathers were highly variable and declined linearly with age. For 58 recaptured Forster's tern chicks, the proportional change in blood mercury concentration was negatively related to the proportional change in body mass, but not to the amount of feathers or wing length. Thus, mercury concentrations declined more in chicks that gained more mass between sampling events. The U-shaped pattern of mercury concentrations from hatching to fledging indicates that juvenile birds may be at highest risk to methylmercury toxicity shortly after hatching when maternally deposited mercury concentrations are still high and again after fledging when opportunities for mass dilution and mercury excretion into feathers are limited.

  6. Planetary health: protecting human health on a rapidly changing planet.

    Science.gov (United States)

    Myers, Samuel S

    2018-12-23

    The impact of human activities on our planet's natural systems has been intensifying rapidly in the past several decades, leading to disruption and transformation of most natural systems. These disruptions in the atmosphere, oceans, and across the terrestrial land surface are not only driving species to extinction, they pose serious threats to human health and wellbeing. Characterising and addressing these threats requires a paradigm shift. In a lecture delivered to the Academy of Medical Sciences on Nov 13, 2017, I describe the scale of human impacts on natural systems and the extensive associated health effects across nearly every dimension of human health. I highlight several overarching themes that emerge from planetary health and suggest advances in the way we train, reward, promote, and fund the generation of health scientists who will be tasked with breaking out of their disciplinary silos to address this urgent constellation of health threats. I propose that protecting the health of future generations requires taking better care of Earth's natural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Alveolar bone changes after asymmetric rapid maxillary expansion.

    Science.gov (United States)

    Akin, Mehmet; Baka, Zeliha Muge; Ileri, Zehra; Basciftci, Faruk Ayhan

    2015-09-01

    To quantitatively evaluate the effects of asymmetric rapid maxillary expansion (ARME) on cortical bone thickness and buccal alveolar bone height (BABH), and to determine the formation of dehiscence and fenestration in the alveolar bone surrounding the posterior teeth, using cone-beam computed tomography (CBCT). The CBCT records of 23 patients with true unilateral posterior skeletal crossbite (10 boys, 14.06 ± 1.08 years old, and 13 girls, 13.64 ± 1.32 years old) who had undergone ARME were selected from our clinic archives. The bonded acrylic ARME appliance, including an occlusal stopper, was used on all patients. CBCT records had been taken before ARME (T1) and after the 3-month retention period (T2). Axial slices of the CBCT images at 3 vertical levels were used to evaluate the buccal and palatal aspects of the canines, first and second premolars, and first molars. Paired samples and independent sample t-tests were used for statistical comparison. The results suggest that buccal cortical bone thickness of the affected side was significantly more affected by the expansion than was the unaffected side (P ARME significantly reduced the BABH of the canines (P ARME also increased the incidence of dehiscence and fenestration on the affected side. ARME may quantitatively decrease buccal cortical bone thickness and height on the affected side.

  8. Memory strength versus memory variability in visual change detection.

    Science.gov (United States)

    Nosofsky, Robert M; Gold, Jason

    2016-01-01

    Observers made change-detection judgments for colored squares in a paradigm that manipulated the retention interval, the magnitude of change, and objective change probability. The probability of change judgments increased across the retention interval for “same” and “small-change” test items but stayed the same or decreased for “large-change” and “far” test items. A variety of formal models were fitted to the individual-subject data. The modeling results provided evidence that, beyond changes in visual-memory precision, there were decreases in memory strength of individual study items across the retention interval. In addition, the modeling results provided evidence of a zero-information, absence-of-memory state that required guessing. The data were not sufficiently strong to sharply distinguish whether the losses in memory strength across the retention interval were continuous in nature or all-or-none. The authors argue that the construct of memory strength as distinct from memory variability is an important component of the nature of forgetting from visual working memory.

  9. Collaborative Research: Improving Decadal Prediction of Arctic Climate Variability and Change Using a Regional Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Gutowski, William J. [Iowa State Univ., Ames, IA (United States)

    2017-12-28

    This project developed and applied a regional Arctic System model for enhanced decadal predictions. It built on successful research by four of the current PIs with support from the DOE Climate Change Prediction Program, which has resulted in the development of a fully coupled Regional Arctic Climate Model (RACM) consisting of atmosphere, land-hydrology, ocean and sea ice components. An expanded RACM, a Regional Arctic System Model (RASM), has been set up to include ice sheets, ice caps, mountain glaciers, and dynamic vegetation to allow investigation of coupled physical processes responsible for decadal-scale climate change and variability in the Arctic. RASM can have high spatial resolution (~4-20 times higher than currently practical in global models) to advance modeling of critical processes and determine the need for their explicit representation in Global Earth System Models (GESMs). The pan-Arctic region is a key indicator of the state of global climate through polar amplification. However, a system-level understanding of critical arctic processes and feedbacks needs further development. Rapid climate change has occurred in a number of Arctic System components during the past few decades, including retreat of the perennial sea ice cover, increased surface melting of the Greenland ice sheet, acceleration and thinning of outlet glaciers, reduced snow cover, thawing permafrost, and shifts in vegetation. Such changes could have significant ramifications for global sea level, the ocean thermohaline circulation and heat budget, ecosystems, native communities, natural resource exploration, and commercial transportation. The overarching goal of the RASM project has been to advance understanding of past and present states of arctic climate and to improve seasonal to decadal predictions. To do this the project has focused on variability and long-term change of energy and freshwater flows through the arctic climate system. The three foci of this research are: - Changes

  10. Morphologic changes of the palate after rapid maxillary expansion: a 3-dimensional computed tomography evaluation.

    Science.gov (United States)

    Phatouros, Andriana; Goonewardene, Mithran S

    2008-07-01

    The purpose of this retrospective study was to estimate the area change of the palate after rapid maxillary expansion (RME) in the early mixed dentition stage by using a 3-dimensional (3D) helical computed tomography (CT) scanning technique. In addition, linear changes in the maxillary arch were evaluated. The treated sample consisted of 43 children (mean age, 9 years 1 month) treated with a bonded RME appliance. The untreated control group consisted of 7 children (mean age, 9 years 3 months). Pretreatment and posttreatment dental casts were evaluated by using 3D helical CT scanning procedures. The Student t test was used to compare the linear, area, and angular differences between the treatment times. RME produced clinically significant increases in interdental widths across the canines, the deciduous first molars, and the permanent first molars in the maxillary arch. Significant increases in cross-sectional area were observed across the permanent first molars (15.3 mm(2)). There was marked variability in the buccal tipping of the permanent first molars. Three-dimensional helical CT scanning is an accurate and cost-effective method of assessing dental cast morphologic changes. It can also provide fast and accurate data acquisition and subsequent analysis.

  11. Dynamic changes at the rapidly advancing Yahtse Glacier, Alaska

    Science.gov (United States)

    Durkin, William J.; Bartholomaus, Timothy C.; Willis, Michael J.; Pritchard, Matthew E.

    2017-03-01

    Since 1990, Yahtse Glacier in southern Alaska has advanced at an average rate of ˜100 m/yr despite of a negative mass balance, widespread thinning in its accumulation area, and a low accumulation-area ratio. To better understand the interannual and seasonal changes at Yahtse and the processes driving these changes, we construct velocity and ice surface elevation time series spanning the years 1985-2014 and 2000-2014, respectively, using satellite optical and synthetic aperture radar (SAR) observations. In terms of seasonal changes, we find contrasting dynamics above and below a steep (up to 18% slope) icefall located approximately 6 km from the terminus. Above the icefall, speeds peak in May and reach minima in October synchronous with the development of a calving embayment at the terminus. This may be caused by an efficient, channelized subglacial drainage system that focuses subglacial discharge into a plume, resulting in a local increase in calving and submarine melting. However, velocities near the terminus are fastest in the winter, following terminus retreat, possibly off of a terminal moraine resulting in decreased backstress. Between 1996-2014 the terminus decelerated by ˜40% at an average rate of ˜0.4 m/day/yr , transitioned from tensile to compressive longitudinal strain rates, and dynamically thickened at rates of 1-6 m/yr , which we hypothesize is in response to the development and advance of a terminal moraine. The described interannual changes decay significantly upstream of the icefall, indicating that the icefall may inhibit the upstream transmission of stress perturbations. We suggest that diminished stress transmission across the icefall could allow Yahtse’s upper basin to remain in a state of mass drawdown despite of moraine-enabled terminus advance. Our work highlights the importance of glacier geometry in controlling tidewater glacier re-advance, particularly in a climate favoring increasing equilibrium line altitudes.

  12. Rapid changes in the gut microbiome during human evolution

    OpenAIRE

    Moeller, Andrew H.; Li, Yingying; Mpoudi Ngole, Eitel; Ahuka-Mundeke, Steve; Lonsdorf, Elizabeth V.; Pusey, Anne E.; Peeters, Martine; Hahn, Beatrice H.; Ochman, Howard

    2014-01-01

    Humans are ecosystems containing trillions of microorganisms, but the evolutionary history of this microbiome is obscured by a lack of knowledge about microbiomes of African apes. We sequenced the gut communities of hundreds of chimpanzees, bonobos, and gorillas and developed a phylogenetic approach to reconstruct how present-day human microbiomes have diverged from those of ancestral populations. Compositional change in the microbiome was slow and clock-like during African ape diversificatio...

  13. Rapid isotopic changes in groundwater, upper Rio Guanajuato catchment, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cortes, Alejandra; Durazo, Jaime [Departamento de recursos naturales, Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Kralisch, Stefanie [Posgrado en Ciencias de la Tierra, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2007-01-15

    Significant changes in the isotopic composition of groundwater in the upper catchment of Rio Guanajuato, Mexico, were detected in two independent sets of samplers for 3 % of the 1600 high-production wells in the area. Sampling was done in December 1998 (53 samples), and in July - August 2003 (41 samples). Average deuterium concentration did not change between 1998 and 2003 but the average oxygen-18 concentration suggested a generalized dilution from deep water from infiltrated local precipitation. This regional change occurred within 56 months, indicating a highly dynamic hydrogeologic system. Fast replenishment of aquifer storage, or non sustainable over-pumping of old aquifer reserves, are possible explanations. [Spanish] Cambios isotopicos significativos en el agua subterranea de la cuenca alta del Rio Guanajuato, Mexico, fueron detectados en dos conjuntos independientes de muestras que incluyeron al 3% de los 1600 pozos de alta produccion del area. Los muestreos se realizaron en diciembre de 1998 (53 muestras) y en julio - agosto del 2003 (41 muestras). La concentracion promedio del deuterio no cambio entre 1998 y 2003, pero la del oxigeno-18 sugiere una dilucion generalizada del agua profunda por infiltracion de la precipitacion local. Este cambio regional ocurrio dentro de 56 meses, indicando un sistema hidrogeologico muy dinamico. La rapida recuperacion del almacenamiento acuifero o el bombeo insostenible de reservas acuiferas viejas son explicaciones posibles.

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

    Science.gov (United States)

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

    2015-05-01

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

  15. Changes in Sea Salt Emissions Enhance ENSO Variability

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang; Russell, Lynn M.; Lou, Sijia; Lamjiri, Maryam A.; Liu, Ying; Singh, Balwinder; Ghan, Steven J.

    2016-11-15

    Two 150-year pre-industrial simulations with and without interactive sea salt emissions from the Community Earth System Model (CESM) are performed to quantify the interactions between sea salt emissions and El Niño–Southern Oscillation (ENSO). Variations in sea salt emissions over the tropical Pacific Ocean are affected by changing wind speed associated with ENSO variability. ENSO-induced interannual variations in sea salt emissions result in decreasing (increasing) aerosol optical depth (AOD) by 0.03 over the equatorial central-eastern (western) Pacific Ocean during El Niño events compared to those during La Niña events. These changes in AOD further increase (decrease) radiative fluxes into the atmosphere by +0.2 W m-2 (-0.4 W m-2) over the tropical eastern (western) Pacific. Thereby, sea surface temperature increases (decreases) by 0.2–0.4 K over the tropical eastern (western) Pacific Ocean during El Niño compared to La Niña events and enhances ENSO variability by 10%. The increase in ENSO amplitude is a result of systematic heating (cooling) during the warm (cold) phase, of ENSO in the eastern Pacific. Interannual variations in sea salt emissions then produce the anomalous ascent (subsidence) over the equatorial eastern (western) Pacific between El Niño and La Niña events, which is a result of heating anomalies. Due to variations in sea salt emissions, the convective precipitation is enhanced by 0.6–1.2 mm day-1 over the tropical central-eastern Pacific Ocean and weakened by 0.9–1.5 mm day-1 over the Maritime Continent during El Niño compared to La Niña events, enhancing the precipitation variability over the tropical Pacific.

  16. Importance of coastal change variables in determining vulnerability to sea- and lake-level change

    Science.gov (United States)

    Pendleton, E.A.; Thieler, E.R.; Williams, S.J.

    2010-01-01

    In 2001, the U.S. Geological Survey began conducting scientific assessments of coastal vulnerability to potential future sea- and lake-level changes in 22 National Park Service sea- and lakeshore units. Coastal park units chosen for the assessment included a variety of geological and physical settings along the U.S. Atlantic, Pacific, Gulf of Mexico, Gulf of Alaska, Caribbean, and Great Lakes shorelines. This research is motivated by the need to understand and anticipate coastal changes caused by accelerating sea-level rise, as well as lake-level changes caused by climate change, over the next century. The goal of these assessments is to provide information that can be used to make long-term (decade to century) management decisions. Here we analyze the results of coastal vulnerability assessments for several coastal national park units. Index-based assessments quantify the likelihood that physical changes may occur based on analysis of the following variables: tidal range, ice cover, wave height, coastal slope, historical shoreline change rate, geomorphology, and historical rate of relative sea- or lake-level change. This approach seeks to combine a coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, and it provides a measure of the system's potential vulnerability to the effects of sea- or lake-level change. Assessments for 22 park units are combined to evaluate relationships among the variables used to derive the index. Results indicate that Atlantic and Gulf of Mexico parks have the highest vulnerability rankings relative to other park regions. A principal component analysis reveals that 99% of the index variability can be explained by four variables: geomorphology, regional coastal slope, water-level change rate, and mean significant wave height. Tidal range, ice cover, and historical shoreline change are not as important when the index is evaluated at large spatial scales (thousands of kilometers

  17. Simulation of rapid ecological change in Lake Ontario

    Science.gov (United States)

    McKenna, James E.; Chalupnicki, Marc; Dittman, Dawn E.; Watkins, James M.

    2017-01-01

    Lower trophic level processes are integral to proper functioning of large aquatic ecosystems and have been disturbed in Lake Ontario by various stressors including exotic species. The invasion of benthic habitats by dreissenid mussels has led to systemic changes and native faunal declines. Size-dependent physiological rates, spatial differences and connectivity, competition, and differential population dynamics among invertebrate groups contributed to the change and system complexity. We developed a spatially explicit, individual-based mechanistic model of the benthic ecosystem in Lake Ontario, with coupling to the pelagic system, to examine ecosystem dynamics and effects of dreissenid mussel invasion and native fauna losses. Benthic organisms were represented by functional groups; filter-feeders (i.e., dreissenid mussels), surface deposit-feeders (e.g., native amphipod Diporeia spp.), and deposit-feeders (e.g., oligochaetes and other burrowers). The model was stable, represented ecological structure and function effectively, and reproduced observed effects of the mussel invasion. Two hypotheses for causes of Diporeia loss, competition or disease-like mortality, were tested. Simple competition for food did not explain observed declines in native surface deposit-feeders during the filter-feeder invasion. However, the elevated mortality scenario supports a disease-like cause for loss of the native amphipod, with population changes in various lake areas and altered benthic biomass transfers. Stabilization of mussel populations and possible recovery of the native, surface-deposit feeding amphipod were predicted. Although further research is required on forcing functions, model parameters, and natural conditions, the model provides a valuable tool to help managers understand the benthic system and plan for response to future disruptions.

  18. Data Requirements for Developing Adaptations to Climate Variability and Change

    Energy Technology Data Exchange (ETDEWEB)

    Basher, Reid E. [National Institute of Water and Atmospheric Research (NIWA), P.O. Box 14 901, Wellington (New Zealand)

    1999-07-01

    An extensive foundation of high quality data and information on the climate and on the biological, environmental and social systems affected by climate is required in order to understand the climate impact processes involved, to develop new adaptation practices, and to subsequently implement these practices. Experience of the impacts of current and past variability of climate and sea level is a prime source of information. Many practices are in use to reduce climate impacts, for example in engineering design, agricultural risk management and climate prediction services, though their roles as adaptations to climate change are not widely appreciated. While there are good data sets on some factors and in some regions, in many cases the databases are inadequate and there are few data sets on adaptation-specific quantities such as vulnerability, resilience and adaptation effectiveness. Current international action under the United Nations Framework Convention on Climate Change (UNFCCC) pays little attention to adaptation and its information requirements. Furthermore there are trends toward reduced data gathering and to restrictions on access to data sets, especially arising from cost and commercialisation pressures. To effectively respond to the changes in climate that are now inevitable, governments will need to more clearly identify adaptation as a central feature of climate change policy and make a renewed shared commitment to collecting and freely exchanging the necessary data. 12 refs.

  19. Managing marine disease emergencies in an era of rapid change.

    Science.gov (United States)

    Groner, Maya L; Maynard, Jeffrey; Breyta, Rachel; Carnegie, Ryan B; Dobson, Andy; Friedman, Carolyn S; Froelich, Brett; Garren, Melissa; Gulland, Frances M D; Heron, Scott F; Noble, Rachel T; Revie, Crawford W; Shields, Jeffrey D; Vanderstichel, Raphaël; Weil, Ernesto; Wyllie-Echeverria, Sandy; Harvell, C Drew

    2016-03-05

    Infectious marine diseases can decimate populations and are increasing among some taxa due to global change and our increasing reliance on marine environments. Marine diseases become emergencies when significant ecological, economic or social impacts occur. We can prepare for and manage these emergencies through improved surveillance, and the development and iterative refinement of approaches to mitigate disease and its impacts. Improving surveillance requires fast, accurate diagnoses, forecasting disease risk and real-time monitoring of disease-promoting environmental conditions. Diversifying impact mitigation involves increasing host resilience to disease, reducing pathogen abundance and managing environmental factors that facilitate disease. Disease surveillance and mitigation can be adaptive if informed by research advances and catalysed by communication among observers, researchers and decision-makers using information-sharing platforms. Recent increases in the awareness of the threats posed by marine diseases may lead to policy frameworks that facilitate the responses and management that marine disease emergencies require. © 2016 The Author(s).

  20. Rapid adaptive responses to climate change in corals

    KAUST Repository

    Torda, Gergely

    2017-09-01

    Pivotal to projecting the fate of coral reefs is the capacity of reef-building corals to acclimatize and adapt to climate change. Transgenerational plasticity may enable some marine organisms to acclimatize over several generations and it has been hypothesized that epigenetic processes and microbial associations might facilitate adaptive responses. However, current evidence is equivocal and understanding of the underlying processes is limited. Here, we discuss prospects for observing transgenerational plasticity in corals and the mechanisms that could enable adaptive plasticity in the coral holobiont, including the potential role of epigenetics and coral-associated microbes. Well-designed and strictly controlled experiments are needed to distinguish transgenerational plasticity from other forms of plasticity, and to elucidate the underlying mechanisms and their relative importance compared with genetic adaptation.

  1. Rapid changes in the gut microbiome during human evolution.

    Science.gov (United States)

    Moeller, Andrew H; Li, Yingying; Mpoudi Ngole, Eitel; Ahuka-Mundeke, Steve; Lonsdorf, Elizabeth V; Pusey, Anne E; Peeters, Martine; Hahn, Beatrice H; Ochman, Howard

    2014-11-18

    Humans are ecosystems containing trillions of microorganisms, but the evolutionary history of this microbiome is obscured by a lack of knowledge about microbiomes of African apes. We sequenced the gut communities of hundreds of chimpanzees, bonobos, and gorillas and developed a phylogenetic approach to reconstruct how present-day human microbiomes have diverged from those of ancestral populations. Compositional change in the microbiome was slow and clock-like during African ape diversification, but human microbiomes have deviated from the ancestral state at an accelerated rate. Relative to the microbiomes of wild apes, human microbiomes have lost ancestral microbial diversity while becoming specialized for animal-based diets. Individual wild apes cultivate more phyla, classes, orders, families, genera, and species of bacteria than do individual humans across a range of societies. These results indicate that humanity has experienced a depletion of the gut flora since diverging from Pan.

  2. Complex interactions in Lake Michigan’s rapidly changing ecosystem

    Science.gov (United States)

    Vanderploeg, Henry A.; Bunnell, David B.; Carrick, Hunter J.; Hook, Tomas O.

    2015-01-01

    For over 30 years, Lake Michigan’s food web has been in a constant state of transition from reductions in nutrient loading and proliferation of invasive species at multiple trophic levels. In particular, there has been concern about impacts from the invasive predatory cercopagids (Bythotrephes longimanus and Cercopagis pengoi) and expanding dreissenid mussel and round goby populations. This special issue brings together papers that explore the status of the Lake Michigan food web and the factors responsible for these changes, and suggests research paths that must be taken for understanding and predicting system behavior. This introductory paper describes the special issue origin, presents an overview of the papers, and draws overarching conclusions from the papers.

  3. Rapid maxillary expansion treatment could produce long-term dental arch changes

    NARCIS (Netherlands)

    Ren, Yijin

    2005-01-01

    : Data Sources: Medline, Medline In-Process, LILACS (Latin American and Caribbean Health Sciences Literature), PUBMED, Embase, Web of Science and the Cochrane Library were searched. Search terms were rapid palatal expansion or rapid maxillary expansion (RME) and tooth or dental changes. Reference

  4. Coral Reefs Under Rapid Climate Change and Ocean Acidification

    Science.gov (United States)

    Hoegh-Guldberg, O.; Mumby, P. J.; Hooten, A. J.; Steneck, R. S.; Greenfield, P.; Gomez, E.; Harvell, C. D.; Sale, P. F.; Edwards, A. J.; Caldeira, K.; Knowlton, N.; Eakin, C. M.; Iglesias-Prieto, R.; Muthiga, N.; Bradbury, R. H.; Dubi, A.; Hatziolos, M. E.

    2007-12-01

    Atmospheric carbon dioxide concentration is expected to exceed 500 parts per million and global temperatures to rise by at least 2°C by 2050 to 2100, values that significantly exceed those of at least the past 420,000 years during which most extant marine organisms evolved. Under conditions expected in the 21st century, global warming and ocean acidification will compromise carbonate accretion, with corals becoming increasingly rare on reef systems. The result will be less diverse reef communities and carbonate reef structures that fail to be maintained. Climate change also exacerbates local stresses from declining water quality and overexploitation of key species, driving reefs increasingly toward the tipping point for functional collapse. This review presents future scenarios for coral reefs that predict increasingly serious consequences for reef-associated fisheries, tourism, coastal protection, and people. As the International Year of the Reef 2008 begins, scaled-up management intervention and decisive action on global emissions are required if the loss of coral-dominated ecosystems is to be avoided.

  5. Ethnobiology 5: Interdisciplinarity in an Era of Rapid Environmental Change

    Directory of Open Access Journals (Sweden)

    Steve Wolverton

    2013-01-01

    Full Text Available Ethnobiology 5 stems from Eugene Hunn’s four phases of the history of ethnobiology and focuses on the relevance of ethnobiological research in the context of environmental and cultural change.  It refers to a contemporary phase of the field’s historical development.  In this paper, I argue that ethnobiology is preadapted to be a scholarly umbrella for a number of disciplines that concern human-environment interactions, suggesting that one goal of Ethnobiology 5 is to bridge traditional academic boundaries in order to broaden the community of ethnobiologists. Another goal of Ethnobiology 5 is to capitalize on and communicate the relevance of ethnobiological scholarship for solving problems related to contemporary environmental and cultural crises.  Indeed, ethnobiology is not a subfield of any traditional discipline and by the nature of its name bridges humanities, social science, and science.  Ethnobiology has always been interdisciplinary in terms of its subject matter, yet its community of scholars is relatively small compared to mission-driven disciplines, such as conservation biology.  Venues for publication and presentation of ethnobiological research, as well as how ethnobiologists portray their research, are critical to growing ethnobiology.

  6. Rapid response to changing environments during biological invasions: DNA methylation perspectives.

    Science.gov (United States)

    Huang, Xuena; Li, Shiguo; Ni, Ping; Gao, Yangchun; Jiang, Bei; Zhou, Zunchun; Zhan, Aibin

    2017-12-01

    Dissecting complex interactions between species and their environments has long been a research hot spot in the fields of ecology and evolutionary biology. The well-recognized Darwinian evolution has well-explained long-term adaptation scenarios; however, "rapid" processes of biological responses to environmental changes remain largely unexplored, particularly molecular mechanisms such as DNA methylation that have recently been proposed to play crucial roles in rapid environmental adaptation. Invasive species, which have capacities to successfully survive rapidly changing environments during biological invasions, provide great opportunities to study molecular mechanisms of rapid environmental adaptation. Here, we used the methylation-sensitive amplified polymorphism (MSAP) technique in an invasive model ascidian, Ciona savignyi, to investigate how species interact with rapidly changing environments at the whole-genome level. We detected quite rapid DNA methylation response: significant changes of DNA methylation frequency and epigenetic differentiation between treatment and control groups occurred only after 1 hr of high-temperature exposure or after 3 hr of low-salinity challenge. In addition, we detected time-dependent hemimethylation changes and increased intragroup epigenetic divergence induced by environmental stresses. Interestingly, we found evidence of DNA methylation resilience, as most stress-induced DNA methylation variation maintained shortly (~48 hr) and quickly returned back to the control levels. Our findings clearly showed that invasive species could rapidly respond to acute environmental changes through DNA methylation modifications, and rapid environmental changes left significant epigenetic signatures at the whole-genome level. All these results provide fundamental background to deeply investigate the contribution of DNA methylation mechanisms to rapid contemporary environmental adaptation. © 2017 John Wiley & Sons Ltd.

  7. Modeling key processes causing climate change and variability

    Energy Technology Data Exchange (ETDEWEB)

    Henriksson, S.

    2013-09-01

    Greenhouse gas warming, internal climate variability and aerosol climate effects are studied and the importance to understand these key processes and being able to separate their influence on the climate is discussed. Aerosol-climate model ECHAM5-HAM and the COSMOS millennium model consisting of atmospheric, ocean and carbon cycle and land-use models are applied and results compared to measurements. Topics at focus are climate sensitivity, quasiperiodic variability with a period of 50-80 years and variability at other timescales, climate effects due to aerosols over India and climate effects of northern hemisphere mid- and high-latitude volcanic eruptions. The main findings of this work are (1) pointing out the remaining challenges in reducing climate sensitivity uncertainty from observational evidence, (2) estimates for the amplitude of a 50-80 year quasiperiodic oscillation in global mean temperature ranging from 0.03 K to 0.17 K and for its phase progression as well as the synchronising effect of external forcing, (3) identifying a power law shape S(f) {proportional_to} f-{alpha} for the spectrum of global mean temperature with {alpha} {approx} 0.8 between multidecadal and El Nino timescales with a smaller exponent in modelled climate without external forcing, (4) separating aerosol properties and climate effects in India by season and location (5) the more efficient dispersion of secondary sulfate aerosols than primary carbonaceous aerosols in the simulations, (6) an increase in monsoon rainfall in northern India due to aerosol light absorption and a probably larger decrease due to aerosol dimming effects and (7) an estimate of mean maximum cooling of 0.19 K due to larger northern hemisphere mid- and high-latitude volcanic eruptions. The results could be applied or useful in better isolating the human-caused climate change signal, in studying the processes further and in more detail, in decadal climate prediction, in model evaluation and in emission policy

  8. Impacts of climate change and variability on European agriculture

    DEFF Research Database (Denmark)

    Orlandini, Simone; Nejedlik, Pavol; Eitzinger, Josef

    2008-01-01

    ; and risk assessment and foreseen impacts on agriculture. The work will be carried out by respective Working Groups. This paper presents the results of the analysis of the first phase of inventory activity. Specific questionnaires were disseminated among COST 734 countries to collect information on climate......Climate plays a fundamental role in agriculture because of to its influence on production. All processes are regulated by specific climatic requirements. Furthermore, European agriculture, based on highly developed farming techniques, is mainly oriented to high quality food production that is more...... susceptible to meteorological hazards. These hazards can modify environment-genotype interactions, which can affect the quality of production. The COST 734 Action (Impacts of Climate Change and Variability on European Agriculture), launched in 2006, is composed of 28 signature countries and is funded...

  9. Environmental forcing and Southern Ocean marine predator populations: effects of climate change and variability.

    Science.gov (United States)

    Trathan, P N; Forcada, J; Murphy, E J

    2007-12-29

    The Southern Ocean is a major component within the global ocean and climate system and potentially the location where the most rapid climate change is most likely to happen, particularly in the high-latitude polar regions. In these regions, even small temperature changes can potentially lead to major environmental perturbations. Climate change is likely to be regional and may be expressed in various ways, including alterations to climate and weather patterns across a variety of time-scales that include changes to the long interdecadal background signals such as the development of the El Niño-Southern Oscillation (ENSO). Oscillating climate signals such as ENSO potentially provide a unique opportunity to explore how biological communities respond to change. This approach is based on the premise that biological responses to shorter-term sub-decadal climate variability signals are potentially the best predictor of biological responses over longer time-scales. Around the Southern Ocean, marine predator populations show periodicity in breeding performance and productivity, with relationships with the environment driven by physical forcing from the ENSO region in the Pacific. Wherever examined, these relationships are congruent with mid-trophic-level processes that are also correlated with environmental variability. The short-term changes to ecosystem structure and function observed during ENSO events herald potential long-term changes that may ensue following regional climate change. For example, in the South Atlantic, failure of Antarctic krill recruitment will inevitably foreshadow recruitment failures in a range of higher trophic-level marine predators. Where predator species are not able to accommodate by switching to other prey species, population-level changes will follow. The Southern Ocean, though oceanographically interconnected, is not a single ecosystem and different areas are dominated by different food webs. Where species occupy different positions in

  10. Ultra-rapid microwave variable pressure-induced histoprocessing : Description of a new tissue processor

    NARCIS (Netherlands)

    Visinoni, F; Milios, J; Leong, ASY; Boon, ME; Kok, LP; Malcangi, F

    We describe a new method of ultra-rapid histoprocessing that reduces the processing times for needle and endoscopic biopsies to 30 min and that of other surgical biopsy tissue blocks of up to 4 mm thick to 120 min. The MicroMED U R M Histoprocessor, which combines microwave irradiation with precise

  11. The rapid cold hardening response of Collembola is influenced by thermal variability of the habitat

    DEFF Research Database (Denmark)

    Bahrndorff, Simon; Loeschcke, Volker; Pertoldi, Cino

    2009-01-01

    exposure to a range of temperatures from 1 ° C to –12 ° C. Rapid cold-hardening (RCH) was induced by cooling individuals from 20 ° C to a temperature 7 ° C above the LT 50 during 80 min, followed by 1 h at the specific cold shock temperature, which was close to the LT 50 of the particular species. 5...

  12. A multiple-proxy approach to understanding rapid Holocene climate change in Southeast Greenland

    Science.gov (United States)

    Davin, S. H.; Bradley, R. S.; Balascio, N. L.; de Wet, G.

    2012-12-01

    The susceptibility of the Arctic to climate change has made it an excellent workshop for paleoclimatological research. Although there have been previous studies concerning climate variability carried out in the Arctic, there remains a critical dearth of knowledge due the limited number of high-resolution Holocene climate-proxy records available from this region. This gap skews our understanding of observed and predicted climate change, and fuels uncertainty both in the realms of science and policy. This study takes a comprehensive approach to tracking Holocene climate variability in the vicinity of Tasiilaq, Southeast Greenland using a ~5.6 m sediment core from Lower Sermilik Lake. An age-depth model for the core has been established using 8 radiocarbon dates, the oldest of which was taken at 4 m down core and has been been dated to approximately 6.2 kyr BP. The bottom meter of the core below the final radiocarbon date contains a transition from cobbles and coarse sand to organic-rich laminations, indicating the termination of direct glacial influence and therefore likely marking the end of the last glacial period in this region. The remainder of the core is similarly organic-rich, with light-to-dark brown laminations ranging from 0.5 -1 cm in thickness and riddled with turbidites. Using this core in tandem with findings from an on-site assessment of the geomorphic history of the locale we attempt to assess and infer the rapid climatic shifts associated with the Holocene on a sub-centennial scale. Such changes include the termination of the last glacial period, the Mid-Holocene Climatic Optimum, the Neoglacial Period, the Medieval Climatic Optimum, and the Little Ice Age. A multiple proxy approach including magnetic susceptibility, bulk organic geochemistry, elemental profiles acquired by XRF scanning, grain-size, and spectral data will be used to characterize the sediment and infer paleoclimate conditions. Additionally, percent biogenic silica by weight has been

  13. Integrated Ocean Management as a Strategy to Meet Rapid Climate Change: The Norwegian Case

    OpenAIRE

    Hoel, Alf Håkon; Olsen, Erik

    2012-01-01

    The prospects of rapid climate change and the potential existence of tipping points in marine ecosystems where nonlinear change may result from them being overstepped, raises the question of strategies for coping with ecosystem change. There is broad agreement that the combined forces of climate change, pollution and increasing economic activities necessitates more comprehensive approaches to oceans management, centering on the concept of ecosystem-based oceans management. This article addres...

  14. Situation Change: Stability and Change of Situation Variables between and within Persons.

    Science.gov (United States)

    Rauthmann, John F; Sherman, Ryne A

    2015-01-01

    When, how, and why situations flow into one another is important for understanding dynamic personality processes, but the topic of situation change has traditionally been a thorny issue in personality/social psychology. We explore conceptual and methodological issues in research on situation change: (1) What is situation change, which variables could we measure, and how can situation change be methodologically captured and analyzed (at between- and within-person levels)? (2) Which person-situation transaction mechanisms (situation management strategies) could entail stability and change of situations in daily life? (3) How do single or repeated instances of situation change impact short-, middle-, and long-term outcomes (e.g., intra- and interpersonal adjustment)? Besides laying out a research program for situation change, we present preliminary data from participants who wore mini-video cameras recording their situations so that they could be rated later in the lab. We demonstrate rater consensus on when situations change, mean-level changes of situation characteristics across situations, similarity of situation characteristics across adjacent situations, and inter-individual differences in intra-individual situation change in change networks.

  15. Situation Change: Stability and Change of Situation Variables Between and Within Persons

    Directory of Open Access Journals (Sweden)

    John F. Rauthmann

    2016-01-01

    Full Text Available When, how, and why situations flow into one another is important for understanding dynamic personality processes, but the topic of situation change has traditionally been a thorny issue in personality/social psychology. We explore conceptual and methodological issues in research on situation change: (1 What is situation change, which variables could we measure, and how can situation change be methodologically captured and analyzed (at between- and within-person levels? (2 Which person-situation transaction mechanisms (situation management strategies could entail stability and change of situations in daily life? (3 How do single or repeated instances of situation change impact short-, middle-, and long-term outcomes (e.g., intra- and interpersonal adjustment? Besides laying out a research program for situation change, we present preliminary data from participants who wore mini-video cameras recording their situations so that they could be rated later in the lab. We demonstrate rater consensus on when situations change, mean-level changes of situation characteristics across situations, similarity of situation characteristics across adjacent situations, and inter-individual differences in intra-individual situation change in change networks.

  16. Rapid effects of diverse toxic water pollutants on chlorophyll a fluorescence: variable responses among freshwater microalgae.

    Science.gov (United States)

    Choi, Chang Jae; Berges, John A; Young, Erica B

    2012-05-15

    Chlorophyll a fluorescence of microalgae is a compelling indicator of toxicity of dissolved water contaminants, because it is easily measured and responds rapidly. While different chl a fluorescence parameters have been examined, most studies have focused on single species and/or a narrow range of toxins. We assessed the utility of one chl a fluorescence parameter, the maximum quantum yield of PSII (F(v)/F(m)), for detecting effects of nine environmental pollutants from a range of toxin classes on 5 commonly found freshwater algal species, as well as the USEPA model species, Pseudokirchneriella subcapitata. F(v)/F(m) declined rapidly over glyphosate (glyphosate increased exponentially with concentration. F(v)/F(m) provides a sensitive and easily-measured parameter for rapid and cost-effective detection of effects of many dissolved toxins. Field-portable fluorometers will facilitate field testing, however distinct responses between different species may complicate net F(v)/F(m) signal from a community. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Urban green land cover changes and their relation to climatic variables in an anthropogenically impacted area

    Science.gov (United States)

    Zoran, Maria A.; Dida, Adrian I.

    2017-10-01

    Urban green areas are experiencing rapid land cover change caused by human-induced land degradation and extreme climatic events. Vegetation index time series provide a useful way to monitor urban vegetation phenological variations. This study quantitatively describes Normalized Difference Vegetation Index NDVI) /Enhanced Vegetation Index (EVI) and Leaf Area Index (LAI) temporal changes for Bucharest metropolitan region land cover in Romania from the perspective of vegetation phenology and its relation with climate changes and extreme climate events. The time series from 2000 to 2016 of the NOAA AVHRR and MODIS Terra/Aqua satellite data were analyzed to extract anomalies. Time series of climatic variables were also analyzed through anomaly detection techniques and the Fourier Transform. Correlations between NDVI/EVI time series and climatic variables were computed. Temperature, rainfall and radiation were significantly correlated with almost all land-cover classes for the harmonic analysis amplitude term. However, vegetation phenology was not correlated with climatic variables for the harmonic analysis phase term suggesting a delay between climatic variations and vegetation response. Training and validation were based on a reference dataset collected from IKONOS high resolution remote sensing data. The mean detection accuracy for period 2000- 2016 was assessed to be of 87%, with a reasonable balance between change commission errors (19.3%), change omission errors (24.7%), and Kappa coefficient of 0.73. This paper demonstrates the potential of moderate - and high resolution, multispectral imagery to map and monitor the evolution of the physical urban green land cover under climate and anthropogenic pressure.

  18. Qualification Testing Versus Quantitative Reliability Testing of PV - Gaining Confidence in a Rapidly Changing Technology: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Repins, Ingrid L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hacke, Peter L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jordan, Dirk [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kempe, Michael D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Whitfield, Kent [Underwriters Laboratories; Phillips, Nancy [DuPont; Sample, Tony [European Commission; Monokroussos, Christos [TUV Rheinland; Hsi, Edward [Swiss RE; Wohlgemuth, John [PowerMark Corporation; Seidel, Peter [First Solar; Jahn, Ulrike [TUV Rheinland; Tanahashi, Tadanori [National Institute of Advanced Industrial Science and Technology; Chen, Yingnan [China General Certification Center; Jaeckel, Bengt [Underwriters Laboratories; Yamamichi, Masaaki [RTS Corporation

    2017-10-05

    Continued growth of PV system deployment would be enhanced by quantitative, low-uncertainty predictions of the degradation and failure rates of PV modules and systems. The intended product lifetime (decades) far exceeds the product development cycle (months), limiting our ability to reduce the uncertainty of the predictions for this rapidly changing technology. Yet, business decisions (setting insurance rates, analyzing return on investment, etc.) require quantitative risk assessment. Moving toward more quantitative assessments requires consideration of many factors, including the intended application, consequence of a possible failure, variability in the manufacturing, installation, and operation, as well as uncertainty in the measured acceleration factors, which provide the basis for predictions based on accelerated tests. As the industry matures, it is useful to periodically assess the overall strategy for standards development and prioritization of research to provide a technical basis both for the standards and the analysis related to the application of those. To this end, this paper suggests a tiered approach to creating risk assessments. Recent and planned potential improvements in international standards are also summarized.

  19. Nevada Monitoring System to Assess Climate Variability and Change

    Science.gov (United States)

    Devitt, D. A.; Arnone, J.; Biondi, F.; Fenstermaker, L. F.; Saito, L.; Young, M.; Riddle, B.; Strachan, S. D.; Bird, B.; McCurdy, G.; Lyles, B. F.

    2010-12-01

    The Nevada System of Higher Education (University of Nevada Las Vegas, University of Nevada Reno and the Desert Research Institute) was awarded a multiyear NSF EPSCoR grant to support infrastructure associated with regional climate change research. The overall project is comprised of 5 components: education, cyberinfrastructure, policy, climate modeling and water/ecology. The water and ecology components are using their infrastructure funding for the assessment of climate variability and change on ecosystem function and hydrologic services. A series of 10 m tall towers are under construction and are being equipped with a wide array of sensors to monitor atmospheric, soil and plant parameters over time. The towers are located within the Mojave and Great Basin Deserts in two transects; the Mojave Desert transect is located in the southern Nevada Sheep Mountain Range and the Great Basin transect is located in the east central Nevada Snake Mountain Range. The towers are centrally positioned in well-defined vegetation zones. In southern Nevada these zones are represented by the following plant species: Creosote/Bursage (Creosotebush scrub zone); Blackbrush/Joshua Tree (Blackbrush zone); Pinyon/ Juniper (pygmy conifer zone), Ponderosa Pine (montane zone) and Bristlecone Pine (subalpine zone). The Snake Mountain transect incorporates the eastern and western valleys on both sides of the mountain range. The vegetation zones are represented by: Greasewood and mixed shrub (salt desert zone); Big Sage (sagebrush zone); Pinyon/Juniper (pygmy conifer zone); White/Douglas Fir, Ponderosa Pine and Aspen (montane zone); and Bristlecone/Limber Pine and Engelmann Spruce (subalpine zone). We are currently in the third year of funding with a goal of having the majority of towers fully operational by winter 2010. In close collaboration with our cyberinfrastructure component team, all data acquired from the transect monitoring stations will be made available to other researchers and the

  20. Principle design of a protontherapy, rapid-cycling, variable energy spiral FFAG

    CERN Document Server

    Antoin, S; Beeckman, W; Collot, J; Conjat, M; Forest, F; Fourrier, J; Froidefond, E; Lancelot, J L; Mandrillon, J; Mandrillon, P; Méot, F; Mori, Y; Neuvéglise, D; Ohmori, C; Pasternak, J; Planche, f, T

    2009-01-01

    The FFAG method is nowadays seen as a potential candidate for the acceleration of protons and light ions for hadrontherapy. This has motivated the design of a principle protontherapy installation, in the frame of the RACCAM project. This article presents the design study, a medical spiral scaling FFAG assembly, capable of producing variable energy proton beams, with potentially high repetition and dose delivery rates.

  1. Curioser and Curioser: New Concepts in the Rapidly Changing Landscape of Educational Administration.

    Science.gov (United States)

    Fowler, Frances C.

    1999-01-01

    The new "Handbook" assumes that society is changing rapidly and educational administration must change with it. This article critiques chapters on four concepts: ideology, the new consumerism, social capital, and the new institutionalism. Consumerism is pure 19th-century liberalism/individualism; social capital theory and…

  2. Rapid climate change did not cause population collapse at the end of the European Bronze Age.

    Science.gov (United States)

    Armit, Ian; Swindles, Graeme T; Becker, Katharina; Plunkett, Gill; Blaauw, Maarten

    2014-12-02

    The impact of rapid climate change on contemporary human populations is of global concern. To contextualize our understanding of human responses to rapid climate change it is necessary to examine the archeological record during past climate transitions. One episode of abrupt climate change has been correlated with societal collapse at the end of the northwestern European Bronze Age. We apply new methods to interrogate archeological and paleoclimate data for this transition in Ireland at a higher level of precision than has previously been possible. We analyze archeological (14)C dates to demonstrate dramatic population collapse and present high-precision proxy climate data, analyzed through Bayesian methods, to provide evidence for a rapid climatic transition at ca. 750 calibrated years B.C. Our results demonstrate that this climatic downturn did not initiate population collapse and highlight the nondeterministic nature of human responses to past climate change.

  3. Holocene climate variability and oceanographic changes off western South Africa

    Science.gov (United States)

    Zhao, Xueqin; Dupont, Lydie; E Meadows, Michael; Schefuß, Enno; Bouimetarhan, Ilham; Wefer, Gerold

    2017-04-01

    and nutrient-rich waters with active upwelling. Thus, sea surface temperatures are dominated by upwelling dynamics influenced by the latitudinal position of the southern westerlies rather than warm waters via the Agulhas leakage. The paleo-productivity changes during the late Holocene are controlled by the freshwater influx of the Orange River indicated by abundant fluvial-related taxa such as Brigantedinium spp., Protoperidinium americanum and Lejeunecysta oliva. This corroborates the increase of Poaceae/Asteraceae ratio suggesting increased summer rainfall in the SRZ. Therefore, the terrestrial (pollen) and marine (dinoflagellate cyst) records generated from the same sediment sequence enable a clear understanding of the mechanisms driving variability in the Holocene of South Africa and provide significant insight into the land-ocean linkages.

  4. Sustainability analysis of bioenergy based land use change under climate change and variability

    Science.gov (United States)

    Raj, C.; Chaubey, I.; Brouder, S. M.; Bowling, L. C.; Cherkauer, K. A.; Frankenberger, J.; Goforth, R. R.; Gramig, B. M.; Volenec, J. J.

    2014-12-01

    Sustainability analyses of futuristic plausible land use and climate change scenarios are critical in making watershed-scale decisions for simultaneous improvement of food, energy and water management. Bioenergy production targets for the US are anticipated to impact farming practices through the introduction of fast growing and high yielding perennial grasses/trees, and use of crop residues as bioenergy feedstocks. These land use/land management changes raise concern over potential environmental impacts of bioenergy crop production scenarios, both in terms of water availability and water quality; impacts that may be exacerbated by climate variability and change. The objective of the study was to assess environmental, economic and biodiversity sustainability of plausible bioenergy scenarios for two watersheds in Midwest US under changing climate scenarios. The study considers fourteen sustainability indicators under nine climate change scenarios from World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3). The distributed hydrological model SWAT (Soil and Water Assessment Tool) was used to simulate perennial bioenergy crops such as Miscanthus and switchgrass, and corn stover removal at various removal rates and their impacts on hydrology and water quality. Species Distribution Models (SDMs) developed to evaluate stream fish response to hydrology and water quality changes associated with land use change were used to quantify biodiversity sustainability of various bioenergy scenarios. The watershed-scale sustainability analysis was done in the St. Joseph River watershed located in Indiana, Michigan, and Ohio; and the Wildcat Creek watershed, located in Indiana. The results indicate streamflow reduction at watershed outlet with increased evapotranspiration demands for high-yielding perennial grasses. Bioenergy crops in general improved in-stream water quality compared to conventional cropping systems (maize-soybean). Water

  5. Rapid Communication: Large exploitable genetic variability exists to shorten age at slaughter in cattle.

    Science.gov (United States)

    Berry, D P; Cromie, A R; Judge, M M

    2017-10-01

    Apprehension among consumers is mounting on the efficiency by which cattle convert feedstuffs into human edible protein and energy as well as the consequential effects on the environment. Most (genetic) studies that attempt to address these issues have generally focused on efficiency metrics defined over a certain time period of an animal's life cycle, predominantly the period representing the linear phase of growth. The age at which an animal reaches the carcass specifications for slaughter, however, is also known to vary between breeds; less is known on the extent of the within-breed variability in age at slaughter. Therefore, the objective of the present study was to quantify the phenotypic and genetic variability in the age at which cattle reach a predefined carcass weight and subcutaneous fat cover. A novel trait, labeled here as the deviation in age at slaughter (DAGE), was represented by the unexplained variability from a statistical model, with age at slaughter as the dependent variable and with the fixed effects, among others, of carcass weight and fat score (scale 1 to 15 scored by video image analysis of the carcass at slaughter). Variance components for DAGE were estimated using either a 2-step approach (i.e., the DAGE phenotype derived first and then variance components estimated) or a 1-step approach (i.e., variance components for age at slaughter estimated directly in a mixed model that included the fixed effects of, among others, carcass weight and carcass fat score as well as a random direct additive genetic effect). The raw phenotypic SD in DAGE was 44.2 d. The genetic SD and heritability for DAGE estimated using the 1-step or 2-step models varied from 14.2 to 15.1 d and from 0.23 to 0.26 (SE 0.02), respectively. Assuming the (genetic) variability in the number of days from birth to reaching a desired carcass specifications can be exploited without any associated unfavorable repercussions, considerable potential exists to improve not only the

  6. Rapid changes in the geomagnetic field: from global to regional scales

    OpenAIRE

    Mandea, M.; Olsen, N; Monika Korte; Verbanac, G.; Y. Yahiat

    2008-01-01

    A large part of the Earth's magnetic field is generated by fluid motion in the molten outer core. Its temporal change, called secular variation, is characterized by occasional rapid changes known as geomagnetic jerks, sudden change in the second time derivative of the magnetic field. For a while, detailed studies of these phenomena suffered from the sparse distribution of geomagnetic observatories over many parts of the Earth. Recent studies on magnetic data provided by magnetic satellites, w...

  7. Effects of temporal changes in climate variables on crop production ...

    African Journals Online (AJOL)

    Administrator

    Key words: Climate variability, crop yield and production, regional climate projections, South-western Nigeria. INTRODUCTION. The variability of the ... continuously facing an immediate risk of increased crop failure and loss of livestock. ... ral productivity may assist in proffering management strategies for a sustainable and ...

  8. Dynamic diagnostic relationism: a new diagnostic paradigm for complex rapidly changing clinical conditions.

    Science.gov (United States)

    Lynn, Lawrence A

    2014-01-01

    Decades of large, apparently well-designed clinical trials have failed to generate reproducible results in the investigation of many complex rapidly evolving and changing conditions such as sepsis. One possibility for the failure is that 20th century threshold science may be too simplistic to apply to complex rapidly changing conditions, especially those with unknown times of onset. There is an acute need to reconsider the fundamental validity of the application of simple threshold science in the study of complex rapidly evolving and changing conditions. In this letter, four potential axioms are presented which define a new science which assesses the probability of disease as a function of motion images of all the available clinical data.

  9. Variability and minimum detectable change for walking energy efficiency variables in children with cerebral palsy.

    Science.gov (United States)

    Thomas, Susan Sienko; Buckon, Cathleen E; Schwartz, Michael H; Russman, Barry S; Sussman, Michael D; Aiona, Michael D

    2009-08-01

    For individuals with neuromuscular disorders, the assessment of walking energy efficiency is useful as a clinical outcome measure. Issues surrounding data collection methodology, normalization of the data, and variability and clinical utility of energy efficiency data preclude universal application. This study examined the variability and the clinical utility of velocity, energy efficiency index (EEI), gross cost, and net nondimensional cost (NNcost) in children and adolescents with spastic diplegic cerebral palsy (CP) in Gross Motor Function Classification System (GMFCS) levels I to III. The energy efficiency of walking was evaluated in 23 children and adolescents (12 males, 11 females, mean age 11y 3mo [SD 3y 5mo]; range 7-17y). Day-to-day variability was similar for all energy efficiency variables, with no significant differences in magnitude of variability between GMFCS levels. Correlations between EEI and gross cost and EEI and NNcost were fairly good (r=0.65, penergy used to ambulate.

  10. The more things change, the more they stay the same? When is trait variability important for stability of ecosystem function in a changing environment.

    Science.gov (United States)

    Wright, Justin P; Ames, Gregory M; Mitchell, Rachel M

    2016-05-19

    The importance of intraspecific trait variability for community dynamics and ecosystem functioning has been underappreciated. There are theoretical reasons for predicting that species that differ in intraspecific trait variability will also differ in their effects on ecosystem functioning, particularly in variable environments. We discuss whether species with greater trait variability are likely to exhibit greater temporal stability in their population dynamics, and under which conditions this might lead to stability in ecosystem functioning. Resolving this requires us to consider several questions. First, are species with high levels of variation for one trait equally variable in others? In particular, is variability in response and effects traits typically correlated? Second, what is the relative contribution of local adaptation and phenotypic plasticity to trait variability? If local adaptation dominates, then stability in function requires one of two conditions: (i) individuals of appropriate phenotypes present in the environment at high enough frequencies to allow for populations to respond rapidly to the changing environment, and (ii) high levels of dispersal and gene flow. While we currently lack sufficient information on the causes and distribution of variability in functional traits, filling in these key data gaps should increase our ability to predict how changing biodiversity will alter ecosystem functioning. © 2016 The Author(s).

  11. Technical variability is greater than biological variability in a microarray experiment but both are outweighed by changes induced by stimulation.

    Directory of Open Access Journals (Sweden)

    Penelope A Bryant

    Full Text Available INTRODUCTION: A central issue in the design of microarray-based analysis of global gene expression is that variability resulting from experimental processes may obscure changes resulting from the effect being investigated. This study quantified the variability in gene expression at each level of a typical in vitro stimulation experiment using human peripheral blood mononuclear cells (PBMC. The primary objective was to determine the magnitude of biological and technical variability relative to the effect being investigated, namely gene expression changes resulting from stimulation with lipopolysaccharide (LPS. METHODS AND RESULTS: Human PBMC were stimulated in vitro with LPS, with replication at 5 levels: 5 subjects each on 2 separate days with technical replication of LPS stimulation, amplification and hybridisation. RNA from samples stimulated with LPS and unstimulated samples were hybridised against common reference RNA on oligonucleotide microarrays. There was a closer correlation in gene expression between replicate hybridisations (0.86-0.93 than between different subjects (0.66-0.78. Deconstruction of the variability at each level of the experimental process showed that technical variability (standard deviation (SD 0.16 was greater than biological variability (SD 0.06, although both were low (SD<0.1 for all individual components. There was variability in gene expression both at baseline and after stimulation with LPS and proportion of cell subsets in PBMC was likely partly responsible for this. However, gene expression changes after stimulation with LPS were much greater than the variability from any source, either individually or combined. CONCLUSIONS: Variability in gene expression was very low and likely to improve further as technical advances are made. The finding that stimulation with LPS has a markedly greater effect on gene expression than the degree of variability provides confidence that microarray-based studies can be used to

  12. Rapid and variable-volume sample loading in sieving electrophoresis microchips using negative pressure combined with electrokinetic force.

    Science.gov (United States)

    Qi, Li-Ya; Yin, Xue-Feng; Zhang, Lei; Wang, Min

    2008-07-01

    A rapid and variable-volume sample loading scheme for chip-based sieving electrophoresis was developed by negative pressure combined with electrokinetic force. This was achieved by using a low-cost microvacuum pump and a single potential supply at a constant voltage. Both 12% linear polyacrylamide (LPA) with a high viscosity of 15000 cP and 2% hydroxyethylcellulose (HEC) with a low viscosity of 102 cP were chosen as the sieving materials to study the behavior and the versatility of the proposed method. To reduce the hydrodynamic resistance in the sampling channel, sieving material was only filled in the separation channel between the buffer waste reservoir (BW) to the edge of the crossed intersection. By applying a subambient pressure to the headspace of sample waste reservoir (SW), sample and buffer solution were drawn immediately from sample reservoir (S) and buffer reservoir (B) across the intersection to SW. At the same time, the charged sample in the sample flow was driven across the interface between the sample flow and the sieving matrix into the sieving material filled separation channel by the applied electric field. The injected sample plug length is in proportion with the loading time. Once the vacuum in SW reservoir was released to activate electrophoretic separation, flows from S and B to SW were immediately terminated by the back flow induced by the difference of the liquid levels in the reservoirs to prevent sample leakage during the separation stage. The sample consumption was about 1.7 x 10(2) nL at a loading time of 1 s for each cycle. Only 0.024 s was required to transport bias-free analyte to the injection point. It is easy to freely choose the sample plug volume in this method by simply changing the loading time and to inject high quality sample plug with non-distorted shape into the separation channel. The system has been proved to possess an exciting potential for improving throughput, repeatability, sensitivity and separation performance of

  13. Monitoring changes in seismic velocity related to an ongoing rapid inflation event at Okmok volcano, Alaska

    Science.gov (United States)

    Bennington, Ninfa; Haney, Matt; De Angelis, Silvio; Thurber, Clifford; Freymueller, Jeff

    2015-01-01

    Okmok is one of the most active volcanoes in the Aleutian Arc. In an effort to improve our ability to detect precursory activity leading to eruption at Okmok, we monitor a recent, and possibly ongoing, GPS-inferred rapid inflation event at the volcano using ambient noise interferometry (ANI). Applying this method, we identify changes in seismic velocity outside of Okmok’s caldera, which are related to the hydrologic cycle. Within the caldera, we observe decreases in seismic velocity that are associated with the GPS-inferred rapid inflation event. We also determine temporal changes in waveform decorrelation and show a continual increase in decorrelation rate over the time associated with the rapid inflation event. Themagnitude of relative velocity decreases and decorrelation rate increases are comparable to previous studies at Piton de la Fournaise that associate such changes with increased production of volatiles and/ormagmatic intrusion within the magma reservoir and associated opening of fractures and/or fissures. Notably, the largest decrease in relative velocity occurs along the intrastation path passing nearest to the center of the caldera. This observation, along with equal amplitude relative velocity decreases revealed via analysis of intracaldera autocorrelations, suggests that the inflation sourcemay be located approximately within the center of the caldera and represent recharge of shallow magma storage in this location. Importantly, there is a relative absence of seismicity associated with this and previous rapid inflation events at Okmok. Thus, these ANI results are the first seismic evidence of such rapid inflation at the volcano.

  14. Solar Variability and Climate Change in the Last 2000 Years

    Science.gov (United States)

    Pang, K.; Yau, K.

    2002-12-01

    Studying past climatic data can help us better understand present natural variations and predict future trends. Identification of cycles can be useful to forecasting. However, various reconstructions of the climate of the last 1000 years have given only broad similarities, with large variances in time and space [Briffa JGR 106, 2929, 2001]. For example, during the Little Ice Age (ca. 1600-1800) severe winters were frequent in Europe and China, but not over Greenland [Sci. Amer., 2/1992, 21]. The differences in modeling results are partly due to uncertainties in the past radiative forcing [Mann, Eos 82 (46), 2001]. Another outstanding question is whether we are in a time similar to Medieval Warm Period. From the frequencies of sunspot and aurora sightings, abundance of carbon-14 in the rings of long-lived trees, and beryllium-10 in the annual layers of polar ice cores, we have reconstructed the recent history of a variable Sun. In the past 1800 years the Sun has gone through nine cycles of changes in brightness. While these long-term changes account for less than one percent of the total irradiance, there is a clear evidence that they affect the climate. During the Maunder Minimum (1645-1715) few sunspots were seen--about 1 in 10 yr from China or Europe--indicative of a weak Sun. Eddy [Science 192, 1189, 1976] used historical aurora, C-14 and climate data to confirm its reality, and link it to the Little Ice Age. Using new historical sunspot catalogues [Yau, Quart. J. Roy. Astron. Soc., 29, 175, 1988], we have identified or confirmed earlier solar minima at 200-300, 400-500, 580-820, 980-1070, 1280-1350, 1410-1590; and maxima at 1080-1280, 1350-1400, etc. All these features are coincident with respective minima or maxima in the frequency of aurora sightings from Europe or Asia. Both time series are in turn consistent with radioisotope data [Pang, Eos. 9/2002]. Carbon-14 and beryllium-10 are made by cosmic rays high in the atmosphere. When the Sun is active the solar

  15. Rapid behavioural gregarization in the desert locust, Schistocerca gregaria entails synchronous changes in both activity and attraction to conspecifics.

    Science.gov (United States)

    Rogers, Stephen M; Cullen, Darron A; Anstey, Michael L; Burrows, Malcolm; Despland, Emma; Dodgson, Tim; Matheson, Tom; Ott, Swidbert R; Stettin, Katja; Sword, Gregory A; Simpson, Stephen J

    2014-06-01

    Desert Locusts can change reversibly between solitarious and gregarious phases, which differ considerably in behaviour, morphology and physiology. The two phases show many behavioural differences including both overall levels of activity and the degree to which they are attracted or repulsed by conspecifics. Solitarious locusts perform infrequent bouts of locomotion characterised by a slow walking pace, groom infrequently and actively avoid other locusts. Gregarious locusts are highly active with a rapid walking pace, groom frequently and are attracted to conspecifics forming cohesive migratory bands as nymphs and/or flying swarms as adults. The sole factor driving the onset of gregarization is the presence of conspecifics. In several previous studies concerned with the mechanism underlying this transformation we have used an aggregate measure of behavioural phase state, Pgreg, derived from logistic regression analysis, which combines and weights several behavioural variables to characterise solitarious and gregarious behaviour. Using this approach we have analysed the time course of behavioural change, the stimuli that induce gregarization and the key role of serotonin in mediating the transformation. Following a recent critique that suggested that using Pgreg may confound changes in general activity with genuine gregarization we have performed a meta-analysis examining the time course of change in the individual behaviours that we use to generate Pgreg. We show that the forced crowding of solitarious locusts, tactile stimulation of the hind femora, and the short-term application of serotonin each induce concerted changes in not only locomotion-related variables but also grooming frequency and attraction to other locusts towards those characteristic of long-term gregarious locusts. This extensive meta-analysis supports and extends our previous conclusions that solitarious locusts undergo a rapid behavioural gregarization upon receiving appropriate stimulation for

  16. Rapid behavioural gregarization in the desert locust, Schistocerca gregaria entails synchronous changes in both activity and attraction to conspecifics

    Science.gov (United States)

    Rogers, Stephen M.; Cullen, Darron A.; Anstey, Michael L.; Burrows, Malcolm; Despland, Emma; Dodgson, Tim; Matheson, Tom; Ott, Swidbert R.; Stettin, Katja; Sword, Gregory A.; Simpson, Stephen J.

    2014-01-01

    Desert Locusts can change reversibly between solitarious and gregarious phases, which differ considerably in behaviour, morphology and physiology. The two phases show many behavioural differences including both overall levels of activity and the degree to which they are attracted or repulsed by conspecifics. Solitarious locusts perform infrequent bouts of locomotion characterised by a slow walking pace, groom infrequently and actively avoid other locusts. Gregarious locusts are highly active with a rapid walking pace, groom frequently and are attracted to conspecifics forming cohesive migratory bands as nymphs and/or flying swarms as adults. The sole factor driving the onset of gregarization is the presence of conspecifics. In several previous studies concerned with the mechanism underlying this transformation we have used an aggregate measure of behavioural phase state, Pgreg, derived from logistic regression analysis, which combines and weights several behavioural variables to characterise solitarious and gregarious behaviour. Using this approach we have analysed the time course of behavioural change, the stimuli that induce gregarization and the key role of serotonin in mediating the transformation. Following a recent critique that suggested that using Pgreg may confound changes in general activity with genuine gregarization we have performed a meta-analysis examining the time course of change in the individual behaviours that we use to generate Pgreg. We show that the forced crowding of solitarious locusts, tactile stimulation of the hind femora, and the short-term application of serotonin each induce concerted changes in not only locomotion-related variables but also grooming frequency and attraction to other locusts towards those characteristic of long-term gregarious locusts. This extensive meta-analysis supports and extends our previous conclusions that solitarious locusts undergo a rapid behavioural gregarization upon receiving appropriate stimulation for

  17. Computed tomographic demonstration of rapid changes in fatty infiltration of the liver

    Energy Technology Data Exchange (ETDEWEB)

    Bashist, B. (Columbia-Presbyterian Medical Center, New York); Hecht, H.L.; Harely, W.D.

    1982-03-01

    Two alcoholic patients in whom computed tomography (CT) demonstrated reversal of fatty infiltration of the liver are described. The rapid reversibility of fatty infiltration can be useful in monitoring alcoholics with fatty livers. Focal fatty infiltration can mimic focal hepatic lesions and repeat scans can be utilized to assess changes in CT attenuation values when this condition is suspected.

  18. Rapidly changing mortality profiles in South Africa in its nine provinces

    African Journals Online (AJOL)

    number from HIV/AIDS and tuberculosis combined by 2012.[1]. Cardiovascular ... diabetes and renal disease have increased.[1,7] Furthermore ... Creative Commons licence CC-BY-NC 4.0. Rapidly changing mortality profiles in South Africa in its nine provinces. Non-communicable disease. HIV/AIDS and TB. Other type 1.

  19. Engaging Chicago residents in climate change action: Results from Rapid Ethnographic Inquiry

    Science.gov (United States)

    Lynne M. Westphal; Jennifer. Hirsch

    2010-01-01

    Addressing climate change requires action at all levels of society, from neighborhood to international levels. Using Rapid Ethnography rooted in Asset Based Community Development theory, we investigated climate-friendly attitudes and behaviors in two Chicago neighborhoods in order to assist the City with implementation of its Climate Action Plan. Our research suggests...

  20. Atlantic tropical cyclones in the twentieth century: natural variability and secular change in cyclone count

    Energy Technology Data Exchange (ETDEWEB)

    Nigam, Sumant [University of Maryland, Department of Atmospheric and Oceanic Science, 3419 Computer and Space Science Building, College Park, MD (United States); Guan, Bin [University of Maryland, Department of Atmospheric and Oceanic Science, 3419 Computer and Space Science Building, College Park, MD (United States); California Institute of Technology, Water and Carbon Cycle Group, Jet Propulsion Laboratory, Pasadena, CA (United States)

    2011-06-15

    -1960s decrease, in contrast, could not be reconstructed at all, leading, deductively, to the hypothesis that it results from increased aerosols in this period. The early-1990s increase is shown to arise both from the abatement of count suppression maintained by SST natural variability and the increasing SST secular trend contribution; the abatement is related to the AMO phase-change in early-1990s. Were it not for this suppression, TC counts would have risen since the early 1970s itself, tracking the secular change contribution. The analysis suggests that when SST natural variability begins to significantly augment counts in the post-1990 period - some evidence for which is present in the preceding decade - Atlantic TC counts could increase rapidly on decadal timescales unless offset by SST-unrelated effects which apparently account for a non-trivial amount (sim40%) of the decadal count variance. (orig.)

  1. Potential impacts of climate change and variability on groundwater ...

    African Journals Online (AJOL)

    Such changes are known to influence subsurface hydrological systems, which could lead to changes in groundwater recharge, discharge and storage of many aquifers. Although, there are uncertainties in the characterisation of climate change induced groundwater impacts due largely to multi-scale local and regional ...

  2. Monitoring of rapid land cover changes in eastern Japan using Terra/MODIS data

    Science.gov (United States)

    Harada, I.; Hara, K.; Park, J.; Asanuma, I.; Tomita, M.; Hasegawa, D.; Short, K.; Fujihara, M.,

    2015-04-01

    Vegetation and land cover in Japan are rapidly changing. Abandoned farmland in 2010, for example, was 396,000 ha, or triple that of 1985. Efficient monitoring of changes in land cover is vital to both conservation of biodiversity and sustainable regional development. The Ministry of Environment is currently producing 1/25,000 scale vegetation maps for all of Japan, but the work is not yet completed. Traditional research is time consuming, and has difficulty coping with the rapid nature of change in the modern world. In this situation, classification of various scale remotely sensed data can be of premier use for efficient and timely monitoring of changes in vegetation.. In this research Terra/MODIS data is utilized to classify land cover in all of eastern Japan. Emphasis is placed on the Tohoku area, where large scale and rapid changes in vegetation have occurred in the aftermath of the Great Eastern Japan Earthquake of 11 March 2011. Large sections of coastal forest and agricultural lands, for example, were directly damaged by the earthquake or inundated by subsequent tsunami. Agricultural land was also abandoned due to radioactive contamination from the Fukushima nuclear power plant accident. The classification results are interpreted within the framework of a Landscape Transformation Sere model developed by Hara et al (2010), which presents a multi-staged pattern for tracking vegetation changes under successively heavy levels of human interference. The results of the research will be useful for balancing conservation of biodiversity and ecosystems with the needs for regional redevelopment.

  3. Impacts of climate change, variability and adaptation strategies on ...

    African Journals Online (AJOL)

    hope&shola

    Accepted 14 July, 2009. A study was carried in two villages of Kamenyanga and Kintinku of Manyoni District, central Tanzania. The overall objective of this study was to understand local communities' perceptions on climate and variability issues and establish its impacts and adaptation strategies within agricultural sector.

  4. Climate variability, farmland value, and farmers’ perceptions of climate change

    NARCIS (Netherlands)

    Arshad, Muhammad; Kächele, Harald; Krupnik, Timothy J.; Amjath-Babu, T.S.; Aravindakshan, Sreejith; Abbas, Azhar; Mehmood, Yasir; Müller, Klaus

    2017-01-01

    Many studies have examined the impact of climatic variability on agricultural productivity, although an understanding of these effects on farmland values and their relationship to farmers’ decisions to adapt and modify their land-use practices remains nascent in developing nations. We estimated

  5. Frightening music triggers rapid changes in brain monoamine receptors: a pilot PET study.

    Science.gov (United States)

    Zhang, Ying; Chen, Qiaozhen; Du, Fenglei; Hu, Yanni; Chao, Fangfang; Tian, Mei; Zhang, Hong

    2012-10-01

    Frightening music can rapidly arouse emotions in listeners that mimic those from actual life-threatening experiences. However, studies of the underlying mechanism for perceiving danger created by music are limited. We investigated monoamine receptor changes induced by frightening music using (11)C-N-methyl-spiperone ((11)C-NMSP) PET. Ten healthy male volunteers were included, and their psychophysiologic changes were evaluated. Compared with the baseline condition, listening to frightening music caused a significant decrease in (11)C-NMSP in the right and left caudate nuclei, right limbic region, and right paralimbic region; a particularly significant decrease in the right anterior cingulate cortex; but an increase in the right frontal occipital and left temporal lobes of the cerebral cortex. Transient fright triggers rapid changes in monoamine receptors, which decrease in the limbic and paralimbic regions but increase in the cerebral cortex.

  6. Rapidly assessing changes in bone mineral balance using natural stable calcium isotopes

    Science.gov (United States)

    Morgan, Jennifer L. L.; Skulan, Joseph L.; Gordon, Gwyneth W.; Romaniello, Stephen J.; Smith, Scott M.; Anbar, Ariel D.

    2012-06-01

    The ability to rapidly detect changes in bone mineral balance (BMB) would be of great value in the early diagnosis and evaluation of therapies for metabolic bone diseases such as osteoporosis and some cancers. However, measurements of BMB are hampered by difficulties with using biochemical markers to quantify the relative rates of bone resorption and formation and the need to wait months to years for altered BMB to produce changes in bone mineral density large enough to resolve by X-ray densitometry. We show here that, in humans, the natural abundances of Ca isotopes in urine change rapidly in response to changes in BMB. In a bed rest experiment, use of high-precision isotope ratio MS allowed the onset of bone loss to be detected in Ca isotope data after about 1 wk, long before bone mineral density has changed enough to be detectable with densitometry. The physiological basis of the relationship between Ca isotopes and BMB is sufficiently understood to allow quantitative translation of changes in Ca isotope abundances to changes in bone mineral density using a simple model. The rate of change of bone mineral density inferred from Ca isotopes is consistent with the rate observed by densitometry in long-term bed rest studies. Ca isotopic analysis provides a powerful way to monitor bone loss, potentially making it possible to diagnose metabolic bone disease and track the impact of treatments more effectively than is currently possible.

  7. Potential impacts of climate change and variability on groundwater ...

    African Journals Online (AJOL)

    Climate change observed over the past decades has been consistently associated with modifications of components of the hydrological systems such as precipitation patterns, sea surface temperature, accelerated melting of glacier and ice caps, soil temperature and moisture, surface runoff and stream flow. Such changes ...

  8. Vulnerability and Adaptation to Climate Variability and Change in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    A changing climate predicting hotter, dryer weather is likely to further affect urban and rural populations, including farmers and wine producers, which provide a major source of employment. A climate change adaptation strategy for the Basin is a priority for the Chilean Ministry of Environment. To support the development of ...

  9. Understanding recent eastern Horn of Africa rainfall variability and change

    Science.gov (United States)

    Liebmann, Brant; Hoerling, Martin P.; Funk, Christopher C.; Blade, Ileana; Dole, Randall M.; Allured, Dave; Quan, Xiaowei; Eischeid, Jon K.

    2014-01-01

    Observations and sea surface temperature (SST)-forced ECHAM5 simulations are examined to study the seasonal cycle of eastern Africa rainfall and its SST sensitivity during 1979–2012, focusing on interannual variability and trends. The eastern Horn is drier than the rest of equatorial Africa, with two distinct wet seasons, and whereas the October–December wet season has become wetter, the March–May season has become drier.

  10. The effect of a graphical interpretation of a statistic trend indicator (Trigg's Tracking Variable) on the detection of simulated changes.

    Science.gov (United States)

    Kennedy, R R; Merry, A F

    2011-09-01

    Anaesthesia involves processing large amounts of information over time. One task of the anaesthetist is to detect substantive changes in physiological variables promptly and reliably. It has been previously demonstrated that a graphical trend display of historical data leads to more rapid detection of such changes. We examined the effect of a graphical indication of the magnitude of Trigg's Tracking Variable, a simple statistically based trend detection algorithm, on the accuracy and latency of the detection of changes in a micro-simulation. Ten anaesthetists each viewed 20 simulations with four variables displayed as the current value with a simple graphical trend display. Values for these variables were generated by a computer model, and updated every second; after a period of stability a change occurred to a new random value at least 10 units from baseline. In 50% of the simulations an indication of the rate of change was given by a five level graphical representation of the value of Trigg's Tracking Variable. Participants were asked to indicate when they thought a change was occurring. Changes were detected 10.9% faster with the trend indicator present (mean 13.1 [SD 3.1] cycles vs 14.6 [SD 3.4] cycles, 95% confidence interval 0.4 to 2.5 cycles, P = 0.013. There was no difference in accuracy of detection (median with trend detection 97% [interquartile range 95 to 100%], without trend detection 100% [98 to 100%]), P = 0.8. We conclude that simple statistical trend detection may speed detection of changes during routine anaesthesia, even when a graphical trend display is present.

  11. climate change and variability: smallholder farming communities in ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Common coping strategies included early planting which was the more ... Key Words: Access to climate information, causes of climate change, coping strategies, farmer ..... content before marketing of produce. .... on field positioning and type.

  12. Impacts of Rainfall Variability and Expected Rainfall Changes on Cost-Effective Adaptation of Water Systems to Climate Change

    NARCIS (Netherlands)

    Pol, van der T.D.; Ierland, van E.C.; Gabbert, S.G.M.; Weikard, H.P.; Hendrix, E.M.T.

    2015-01-01

    Stormwater drainage and other water systems are vulnerable to changes in rainfall and runoff and need to be adapted to climate change. This paper studies impacts of rainfall variability and changing return periods of rainfall extremes on cost-effective adaptation of water systems to climate change

  13. Rapid Hip Osteoarthritis Development in a Patient with Anterior Acetabular Cyst with Sagittal Alignment Change

    Directory of Open Access Journals (Sweden)

    Yasuhiro Homma

    2014-01-01

    Full Text Available Rapidly destructive coxarthrosis (RDC is rare and develops unusual clinical course. Recent studies suggest multiple possible mechanisms of the development of RDC. However the exact mechanism of RDC is still not clear. The difficulty of the study on RDC is attributed to its rareness and the fact that the data before the onset of RDC is normally unavailable. In this report, we presented the patient having the radiographic data before the onset who had rapid osteoarthritis (OA development after contralateral THA, which meets the current criteria of RDC. We thought that the increased posterior tilt of the pelvis after THA reinforced the stress concentration at pre-existed anterior acetabular cyst, thereby the destruction of the cyst was occurred. As a result the rapid OA was developed. We think that there is the case of rapid osteoarthritis developing due to alternating load concentration by posterior pelvic tilt on preexisting anterior acetabular cyst such as our patient among the cases diagnosed as RDC without any identifiable etiology. The recognition of sagittal alignment changes and anterior acetabular cyst may play important role in prediction and prevention of the rapid hip osteoarthritis development similar to RDC.

  14. Recent changes in phytoplankton communities associated with rapid regional climate change along the western Antarctic Peninsula.

    Science.gov (United States)

    Montes-Hugo, Martin; Doney, Scott C; Ducklow, Hugh W; Fraser, William; Martinson, Douglas; Stammerjohn, Sharon E; Schofield, Oscar

    2009-03-13

    The climate of the western shelf of the Antarctic Peninsula (WAP) is undergoing a transition from a cold-dry polar-type climate to a warm-humid sub-Antarctic-type climate. Using three decades of satellite and field data, we document that ocean biological productivity, inferred from chlorophyll a concentration (Chl a), has significantly changed along the WAP shelf. Summertime surface Chl a (summer integrated Chl a approximately 63% of annually integrated Chl a) declined by 12% along the WAP over the past 30 years, with the largest decreases equatorward of 63 degrees S and with substantial increases in Chl a occurring farther south. The latitudinal variation in Chl a trends reflects shifting patterns of ice cover, cloud formation, and windiness affecting water-column mixing. Regional changes in phytoplankton coincide with observed changes in krill (Euphausia superba) and penguin populations.

  15. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Antonius G T Schut

    Full Text Available Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic Region (SWAFR. However, poor characterization of GOs limits the capacity of conservation planning for refugia under climate change. A novel means for the rapid identification of potential refugia is presented, based on the assessment of local-scale environment and vegetation structure in a wider region. This approach was tested on GOs across the SWAFR. Airborne discrete return Light Detection And Ranging (LiDAR data and Red Green and Blue (RGB imagery were acquired. Vertical vegetation profiles were used to derive 54 structural classes. Structural vegetation types were described in three areas for supervised classification of a further 13 GOs across the region. Habitat descriptions based on 494 vegetation plots on and around these GOs were used to quantify relationships between environmental variables, ground cover and canopy height. The vegetation surrounding GOs is strongly related to structural vegetation types (Kappa = 0.8 and to its spatial context. Water gaining sites around GOs are characterized by taller and denser vegetation in all areas. The strong relationship between rainfall, soil-depth, and vegetation structure (R(2 of 0.8-0.9 allowed comparisons of vegetation structure between current and future climate. Significant shifts in vegetation structural types were predicted and mapped for future climates. Water gaining areas below granite outcrops were identified as important putative refugia. A reduction in rainfall may be offset by the occurrence of deeper soil elsewhere on the outcrop. However, climate change interactions with fire and water table declines may render our conclusions conservative. The LiDAR-based mapping approach presented

  16. Effects of high latitude protected areas on bird communities under rapid climate change.

    Science.gov (United States)

    Santangeli, Andrea; Rajasärkkä, Ari; Lehikoinen, Aleksi

    2017-06-01

    Anthropogenic climate change is rapidly becoming one of the main threats to biodiversity, along with other threats triggered by human-driven land-use change. Species are already responding to climate change by shifting their distributions polewards. This shift may create a spatial mismatch between dynamic species distributions and static protected areas (PAs). As protected areas represent one of the main pillars for preserving biodiversity today and in the future, it is important to assess their contribution in sheltering the biodiversity communities, they were designated to protect. A recent development to investigate climate-driven impacts on biological communities is represented by the community temperature index (CTI). CTI provides a measure of the relative temperature average of a community in a specific assemblage. CTI value will be higher for assemblages dominated by warm species compared with those dominated by cold-dwelling species. We here model changes in the CTI of Finnish bird assemblages, as well as changes in species densities, within and outside of PAs during the past four decades in a large boreal landscape under rapid change. We show that CTI has markedly increased over time across Finland, with this change being similar within and outside PAs and five to seven times slower than the temperature increase. Moreover, CTI has been constantly lower within than outside of PAs, and PAs still support communities, which show colder thermal index than those outside of PAs in the 1970s and 1980s. This result can be explained by the higher relative density of northern species within PAs than outside. Overall, our results provide some, albeit inconclusive, evidence that PAs may play a role in supporting the community of northern species. Results also suggest that communities are, however, shifting rapidly, both inside and outside of PAs, highlighting the need for adjusting conservation measures before it is too late. © 2016 John Wiley & Sons Ltd.

  17. Changes in metabolic-related variables during chronic morphine treatment.

    Science.gov (United States)

    Ferenczi, Szilamér; Núñez, Cristina; Pintér-Kübler, Bernadett; Földes, Anna; Martín, Fátima; Márkus, Vera Ladnyánszky; Milanés, M Victoria; Kovács, Krisztina J

    2010-10-01

    To reveal neuroendocrine/neurochemical changes that are responsible for the robust metabolic alterations seen during chronic morphine treatment we followed hormonal-, transcriptional- and behavioral changes during chronic morphine administration in adult male Wistar rats. Animals were implanted with increasing amount of slow release morphine tablets for 8 days. Morphine treated animals gain significantly less weight than placebo implanted controls. This weight loss is due to the dramatic decrease in the food intake and caloric efficiency in the first days of drug administration and to the lasting disregulated feeding pattern. Changes in feeding behavior included increase of diurnal and decrease of nocturnal feeding frequency in morphine treated rats. Significantly less leptin and insulin plasma levels were detected in morphine implanted animals than in placebo implanted controls, while adiponectin and ACTH concentration remain unchanged. Morphine treated rats display an increase of FosB/Delta FosB immunoreactivity at brain sites that have been implicated regulation of food intake and energy expenditure, including hypothalamic arcuate, paraventricular and ventromedial nuclei and in the lateral hypothalamic area as well as in the caudal brainstem. However, morphine-induced long-term metabolic alterations were not accompanied with any significant changes in the expression of anorexigenic neuropeptides POMC and CART in the hypothalamus and in the brainstem. The disregulated feeding pattern was not reflected in changes of orexin transcription, however, a compensatory upregulation was revealed in hypothalamic NPY expression. (c) 2010 Elsevier Ltd. All rights reserved.

  18. A plant’s perspective of extremes: Terrestrial plant responses to changing climatic variability

    Science.gov (United States)

    Reyer, C.; Leuzinger, S.; Rammig, A.; Wolf, A.; Bartholomeus, R. P.; Bonfante, A.; de Lorenzi, F.; Dury, M.; Gloning, P.; Abou Jaoudé, R.; Klein, T.; Kuster, T. M.; Martins, M.; Niedrist, G.; Riccardi, M.; Wohlfahrt, G.; de Angelis, P.; de Dato, G.; François, L.; Menzel, A.; Pereira, M.

    2013-01-01

    We review observational, experimental and model results on how plants respond to extreme climatic conditions induced by changing climatic variability. Distinguishing between impacts of changing mean climatic conditions and changing climatic variability on terrestrial ecosystems is generally underrated in current studies. The goals of our review are thus (1) to identify plant processes that are vulnerable to changes in the variability of climatic variables rather than to changes in their mean, and (2) to depict/evaluate available study designs to quantify responses of plants to changing climatic variability. We find that phenology is largely affected by changing mean climate but also that impacts of climatic variability are much less studied but potentially damaging. We note that plant water relations seem to be very vulnerable to extremes driven by changes in temperature and precipitation and that heatwaves and flooding have stronger impacts on physiological processes than changing mean climate. Moreover, interacting phenological and physiological processes are likely to further complicate plant responses to changing climatic variability. Phenological and physiological processes and their interactions culminate in even more sophisticated responses to changing mean climate and climatic variability at the species and community level. Generally, observational studies are well suited to study plant responses to changing mean climate, but less suitable to gain a mechanistic understanding of plant responses to climatic variability. Experiments seem best suited to simulate extreme events. In models, temporal resolution and model structure are crucial to capture plant responses to changing climatic variability. We highlight that a combination of experimental, observational and /or modeling studies have the potential to overcome important caveats of the respective individual approaches. PMID:23504722

  19. Cephalometric variables used to predict the success of interceptive treatment with rapid maxillary expansion and face mask. A longitudinal study

    Directory of Open Access Journals (Sweden)

    Daniele Nóbrega Nardoni

    2015-02-01

    Full Text Available INTRODUCTION: Prognosis is the main limitation of interceptive treatment of Class III malocclusions. The interceptive procedures of rapid maxillary expansion (RME and face mask therapy performed in early mixed dentition are capable of achieving immediate overcorrection and maintenance of facial and occlusal morphology for a few years. Individuals presenting minimal acceptable faces at growth completion are potential candidates for compensatory orthodontic treatment, while those with facial involvement should be submitted to orthodontic decompensation for orthognathic surgery. OBJECTIVES: To investigate cephalometric variables that might predict the outcomes of orthopedic treatment with RME and face mask therapy (FM. METHODS: Cephalometric analysis of 26 Class III patients (mean age of 8 years and 4 months was performed at treatment onset and after a mean period of 6 years and 10 months at pubertal growth completion, including a subjective facial analysis. Patients was divided into two groups: success group (21 individuals and failure group (5 individuals. Discriminant analysis was applied to the cephalometric values at treatment onset. Two predictor variables were found by stepwise procedure. RESULTS: Orthopedic treatment of Class III malocclusion may have unfavorable prognosis at growth completion whenever initial cephalometric analysis reveals increased lower anterior facial height (LAFH combined with reduced angle between the condylar axis and the mandibular plane (CondAx.MP. CONCLUSION: The results of treatment with RME and face mask therapy at growth completion in Class III patients could be predicted with a probability of 88.5%.

  20. Nebulization of active pharmaceutical ingredients with the eFlow(®) rapid: impact of formulation variables on aerodynamic characteristics.

    Science.gov (United States)

    Beck-Broichsitter, Moritz; Prüfer, Nadine; Oesterheld, Nina; Seeger, Werner; Schmehl, Thomas

    2014-08-01

    Nebulization of active pharmaceutical ingredient (API) solutions is a well-established means to achieve pulmonary drug deposition. The current study identified the impact of formulation variables on the aerosolization performance of the eFlow(®) rapid with special respect to optimized lung application. API formulations (including excipient-supplemented samples) were investigated for physicochemical properties, then nebulized using vibrating-mesh technology. The generated aerosol clouds were analyzed by laser diffraction. Aerosol deposition characteristics in the human respiratory tract were estimated using an algebraic model. Remarkable effects on aerosolization performance [i.e., mass median aerodynamic diameter (MMAD)] of API solutions were obtained when the sample conductivity (by API concentration and type, sodium chloride addition) and dynamic viscosity (by application of sucrose and poly(ethylene glycol) 200) were elevated. A similar influence was observed for a decline in surface tension (by ethanol addition). Thus, a defined adjustment of formulation parameters allowed for a decrease of the MMAD from ∼ 8.0 μm to values as small as ∼ 3.5 μm. Consequently, the pattern and efficiency of aerosol deposition in the human respiratory tract were improved. In conclusion, identification of physicochemical variables and their way of influencing vibrating-mesh nebulization has been provided to deliver a platform for tailoring aerosol characteristics and thus, advancing pulmonary therapy. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  1. Rapid assessment of large scale vegetation change based on multi-temporal phenological analysis

    Science.gov (United States)

    Cai, Danlu; Guan, Yanning; Guo, Shan; Yan, Baoping; Xing, Zhi; Zhang, Chunyan; Piao, Yingchao; An, Xudong; Kang, Lihua

    2011-11-01

    Detecting vegetation change is critical for earth system and sustainability science. The existing methods, however, show several limitations, including inevitable selection of imagery acquisition dates, affection from vegetation related noise on temporal trajectory analysis, and assumptions due to vegetation classification model. This paper presents a multitemporal phenological frequency analysis over a relatively short period (MTPFA-SP) methodology to detect vegetation changes. This MTPFA-SP methodology bases on the amplitude components of fast Fourier transforming (FFT) and is implemented with two steps. First, NDVI time series over two periods are transformed with FFT into frequency domain, separately. Second, amplitude components with phenological information from Step 1 are selected for further change comparison. In this methodology, component selection shows physical meanings of natural vegetation process in frequency domain. Comparisons among those selected components help enhance the ability to rapidly detect vegetation changes. To validate this MTPFA-SP methodology, we detect changes between two periods (2001-2005 and 2006-2010) in the eastern Tibet Plateau area and make two kinds of assessments. The first is for a larger scale, including statistic analysis of altitudinal zonality and latitudinal zonality. The second assessment is for rapid detection of vegetation change location. Landsat TM image were employed to validate the result.

  2. Rapid climate changes in the tropical Atlantic region during the last deglaciation

    Science.gov (United States)

    Hughen, Konrad A.; Overpeck, Jonathan T.; Peterson, Larry C.; Trumbore, Susan

    1996-03-01

    THE climate system is capable of changing abruptly from one stable mode to another1-3. Rapid climate oscillations-in particular the Younger Dryas cold period during the last deglaciation-have long been recognized from records throughout the North Atlantic region4-14, and the distribution of these records at mostly high latitudes suggests that the changes were caused by rapid reorganizations of the North Atlantic thermohaline circulation6,8,10,15. But events far from the North Atlantic region that are synchronous with the Younger Dryas16-19 raise the possibility that a more global forcing mechanism was responsible20. Here we present high-resolution records of laminated sediments of the last deglaciation from the Cariaco basin (tropical Atlantic Ocean) which show many abrupt sub-decade to century-scale oscillations in surface-ocean biological productivity that are synchronous with climate changes at high latitudes. We attribute these productivity variations to changes in or duration of up-welling rate (and hence nutrient supply) caused by changes in trade-wind strength, which is in turn influenced by the thermo-haline circulation through its effect on sea surface temperature6,21. Abrupt climate changes in the tropical Atlantic during the last deglaciation are thus consistent with a North Atlantic circulation forcing mechanism.

  3. Changes in nasal air flow and school grades after rapid maxillary expansion in oral breathing children

    OpenAIRE

    Torre, Hilda; Alarcón, Jose Antonio

    2012-01-01

    Objective: To analyse the changes in nasal air flow and school grades after rapid maxillary expansion (RME) in oral breathing children with maxillary constriction. Material and Methods: Forty-four oral breathing children (mean age 10.57 y) underwent orthodontic RME with a Hyrax screw. Forty-four age-matched children (mean age 10.64 y) with nasal physiological breathing and adequate transverse maxillary dimensions served as the control group. The maxillary widths, nasal air flow assessed via p...

  4. Environmental impacts of rapid water level changes; Miljoekonsekvenser av raske vannstandsendringer

    Energy Technology Data Exchange (ETDEWEB)

    Arnekleiv, Jo Vegar; Bakken, Tor Haakon; Bogen, Jim; Boensnes, Truls Erik; Elster, Margrethe; Harby, Atle; Kutznetsova, Yulia; Saltveit, Svein Jakob; Sauterleute, Julian; Stickler, Morten; Sundt, Haakon; Tjomsland, Torulv; Ugedal, Ola

    2012-07-01

    This report summarizes the state of knowledge of the environmental impacts of power driving and rapid water level changes and describes possible mitigation measures. The report assesses the environmental effects of possible increased power installation in Mauranger and Tonstad power plants, based on existing data and knowledge. At Straumsmo plants in Barduelva there are collected some physical data and the environmental impact of existing power driving is considered. (eb)

  5. Impacts of climate change and variability, and adaptation strategies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    13 mai 2011 ... This article appeared in the August 2009 volume of the African Journal of Environmental Science and Technology. The Climate Change Adaptation in Africa research and capacity development program was launched in 2006 as a joint initiative between Canada's International Development Research ...

  6. Changes of hemostatic variables during oral contraceptive use

    NARCIS (Netherlands)

    Tans, Guido; Bouma, Bonno N.; Büller, Harry R.; Rosing, Jan

    2003-01-01

    The use of oral contraceptives (OCs) has been known for many years to affect significantly almost all hemostatic parameters, but the challenge to relate these changes in a meaningful way to OC-induced increased venous thrombotic risk has not been met. New insights indicate that at least part of the

  7. Vulnerability and Adaptation to Climate Variability and Change in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    To support the development of such a strategy, this project will conduct comprehensive research led by the Centre for Global Change at the Pontificia ... problem of land competition, as urban sectors encroach on rural territories, challenging institutional capacities and plans for managing Latin American metropolitan regions.

  8. Adapting to climate variability and change in Chile's Maipo basin ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2014-04-09

    Apr 9, 2014 ... The team is involving students from other Latin American countries and will share findings widely, including through peer-reviewed journals and at international conferences. As a result, the university's Center for Global Change stands to become a regional centre of excellence, able to help other regions ...

  9. Climate Change and Variability: Implications for Household Food ...

    African Journals Online (AJOL)

    The econometric model estimation result revealed the important factors determining household food security. These are household perception of climate change, use of soil and water conservation practices, use of livestock feed management techniques, loss of livestock due to drought and/or disease, literacy level of ...

  10. Impacts of climate change and variability, and adaptation strategies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-04-25

    Apr 25, 2016 ... In Tanzania, agriculture plays a critical role in providing food and income for most of its people. More than 70% of the population depends on subsistence agriculture, which is almost entirely rainfed. Given this overdependence on rainfed agriculture, farmers are highly vulnerable to climate change. In recent ...

  11. Impacts of climate change, variability and adaptation strategies on ...

    African Journals Online (AJOL)

    There are different wealth groups namely the rich, the middle and the poor and these are differently vulnerable climate change. The study concluded that, the wealth of knowledge on coping and adaptation that farmer has should form a foundation for designing agricultural innovation systems to deal with impacts of climate ...

  12. Adapting to climate variability and change in Chile's Maipo basin ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    But pressure on the Maipo basin is rising as Santiago's population and industries grow, and as the country looks to tap hydro-electrical power from the basin's tributaries upstream. Meanwhile, climate change projections show temperatures rising as rainfall declines. Given the region's role in Chile's national economy, ...

  13. Evaluation of rapid volume changes of substrate-adherent cells by conventional microscopy 3D imaging.

    Science.gov (United States)

    Boudreault, F; Grygorczyk, R

    2004-09-01

    Precise measurement of rapid volume changes of substrate-adherent cells is essential to understand many aspects of cell physiology, yet techniques to evaluate volume changes with sufficient precision and high temporal resolution are limited. Here, we describe a novel imaging method that surveys the rapid morphology modifications of living, substrate-adherent cells based on phase-contrast, digital video microscopy. Cells grown on a glass substrate are mounted in a custom-designed, side-viewing chamber and subjected to hypotonic swelling. Side-view images of the rapidly swelling cell, and at the end of the assay, an image of the same cell viewed from a perpendicular direction through the substrate, are acquired. Based on these images, off-line reconstruction of 3D cell morphology is performed, which precisely measures cell volume, height and surface at different points during cell volume changes. Volume evaluations are comparable to those obtained by confocal laser scanning microscopy (DeltaVolume microscopy without the need for cell staining or intense illumination to monitor cell volume make this system a promising new tool to investigate the fundamentals of cell volume physiology.

  14. Rapid and specific gray matter changes in M1 induced by balance training.

    Science.gov (United States)

    Taubert, Marco; Mehnert, Jan; Pleger, Burkhard; Villringer, Arno

    2016-06-01

    Training-induced changes in cortical structure can be observed non-invasively with magnetic resonance imaging (MRI). While macroscopic changes were found mainly after weeks to several months of training in humans, imaging of motor cortical networks in animals revealed rapid microstructural alterations after a few hours of training. We used MRI to test the hypothesis of immediate and specific training-induced alterations in motor cortical gray matter in humans. We found localized increases in motor cortical thickness after 1h of practice in a complex balancing task. These changes were specific to motor cortical effector representations primarily responsible for balance control in our task (lower limb and trunk) and these effects could be confirmed in a replication study. Cortical thickness changes (i) linearly increased across the training session, (ii) occurred independent of alterations in resting cerebral blood flow and (iii) were not triggered by repetitive use of the lower limbs. Our findings show that motor learning triggers rapid and specific gray matter changes in M1. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Salinity changes relative to the response to anthropogenic forcing and internal variability in the North Atlantic

    Science.gov (United States)

    Vinogradova, Nadya; Buckley, Martha

    2017-04-01

    Over the past few decades, surface waters in the subpolar North Atlantic have experienced substantial fluctuations, including periods of rapid cooling and freshening alternating with the periods of enhanced warming, salinification, and decreased circulation of the gyre. Since these waters feed the North Atlantic thermohaline circulation, such changes have the potential to impact the global ocean circulation and future climate states. A number of potential causes for the observed changes have been suggested, including those related to the strength of the ocean circulation and heat transports, as well as other factors, such as anthropogenic aerosol forcing or changes in surface fluxes. Here we assess how the observed warming/salinification events fit into the long-term picture, focusing on variations in upper-ocean salinity. Salinification of the subpolar North Atlantic may seem counter-intuitive to the reported long-term increase in freshwater supply to the region from river discharge and ice melting, sparking debates about whether the freshening of the subpolar gyre has ceased, and whether the recent salinification, if continued, will be able to forestall the projected slowdown of the overturning circulation. Using a suite of in situ salinity observations spanning the last 60 years, modern satellite salinity observations from Aquarius and SMOS missions, and multi-decadal realizations from global climate models, we estimate the likelihood of such salinity changes in the context of the historical record, contemporary estimates, and future projections. Results are discussed in terms of the probability of occurrence of a decade-long salinification in the presence of the background freshening in response to anthropogenic forcing. In particular, computed probabilities suggest that such "unusual" salinification events are plausible under the strong influence of internal, decadal-to-interdecadal variability.

  16. Rapid changes in brain structure predict improvements induced by perceptual learning.

    Science.gov (United States)

    Ditye, Thomas; Kanai, Ryota; Bahrami, Bahador; Muggleton, Neil G; Rees, Geraint; Walsh, Vincent

    2013-11-01

    Practice-dependent changes in brain structure can occur in task relevant brain regions as a result of extensive training in complex motor tasks and long-term cognitive training but little is known about the impact of visual perceptual learning on brain structure. Here we studied the effect of five days of visual perceptual learning in a motion-color conjunction search task using anatomical MRI. We found rapid changes in gray matter volume in the right posterior superior temporal sulcus, an area sensitive to coherently moving stimuli, that predicted the degree to which an individual's performance improved with training. Furthermore, behavioral improvements were also predicted by volumetric changes in an extended white matter region underlying the visual cortex. These findings point towards quick and efficient plastic neural mechanisms that enable the visual brain to deal effectively with changing environmental demands. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Assessment of early thromboelastometric variables from extrinsically activated assays with and without aprotinin for rapid detection of fibrinolysis.

    Science.gov (United States)

    Dirkmann, Daniel; Görlinger, Klaus; Peters, Jürgen

    2014-09-01

    Although thromboelastometry (ROTEM®) and thrombelastography can be used for bedside diagnosis of fibrinolysis, the time needed for detection is often prolonged. Since untreated fibrinolysis can result in consumption of coagulation factors and bleeding, early diagnosis and decision making are desirable. Accordingly, we assessed ROTEM variables from extrinsically activated assays with (APTEM) and without (EXTEM) addition of aprotinin for their ability to rapidly identify fibrinolysis. Specifically, we tested the hypotheses that prolonged clotting time, clot formation time, low clot firmness (at 5, 10, 15, and 20 minutes, designated A5, A10, A15, and A20, respectively), low maximum clot firmness (MCF) in EXTEM assays, and differences in these variables from parallel APTEM and EXTEM assays (designated as Δvariables) predict fibrinolysis. Data from 411 thromboelastometric measurements (obtained from 352 patients) with fibrinolysis and from 2537 measurements without fibrinolysis (obtained from 1605 patients) were assessed and analyzed using receiver operating characteristics. Data were analyzed as a pooled fibrinolysis cohort, and subanalyses were performed from sets assigned to categories of fibrinolysis related to the timing of thrombus lysis (i.e., a decrease of clot firmness to fibrinolysis. AUCs were compared to identify the variable providing the best predictive association with fibrinolysis. As a secondary end point, optimum cutoff values at the point estimate corresponding to the greatest Youden index were calculated along with the respective sensitivities and specificities. In the pooled cohort, clot formation time (AUC: 0.652 [0.016]), α-angle (AUC: 0.675 [0.015]), A5 (AUC: 0.718 [0.013]), A10 (AUC: 0.734 [0.0.13]), A15 (AUC: 0.752 [0.013]), A20 (AUC: 0.771 [0.013]), and MCF (AUC: 0.799 [0.012]) predicted fibrinolysis. Fibrinolysis was also predicted by ΔA15 (AUC: 0.675 [0.016]), ΔA20 (AUC: 0.719 [0.015]), and ΔMCF (AUC: 0.812 [0.013]). AUCs increased in

  18. Lung health and heart rate variability changes in salt workers.

    Science.gov (United States)

    Glad Mohesh, M I; Sundaramurthy, A

    2016-04-01

    India is the third largest salt producing country in the World, with a global annual production of 230 million tonnes. Large number of salt workers get employed in these salt milling plants risking their life from the effects of salt. Recent foreign evidences reported that these salt workers are exposed to aerosol salt particles that disturb their lung and cardiovascular autonomic control. To compare the status of lung health, cardiovascular autonomic control and biochemical changes in a group of salt industry workers with that of the age-matched normal subjects. Volunteers of both sexes (25-35 years) were divided into Group I (n=10) controls and Group II (n=10) non-brine salt workers in salt milling plants. From fasting blood sample, complete blood count, plasma electrolyte and lipid profile estimation were done. After resting for 15min, blood pressure and lead II ECG were recorded. Spirometry was done using RMS Helios spirometer. Data collected were later analysed using GraphPad Prism 5.0 with statistical significance set at pworkers in the salt industry has shown a little or no impact on the respiratory system, however there are changes in the blood and cardiovascular system, which need to be further studied to understand the long-term influences of salt in this population. Copyright © 2015 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

  19. Rapid environmental change over the past decade revealed by isotopic analysis of the California mussel in the northeast Pacific.

    Directory of Open Access Journals (Sweden)

    Catherine A Pfister

    Full Text Available The anthropogenic input of fossil fuel carbon into the atmosphere results in increased carbon dioxide (CO(2 into the oceans, a process that lowers seawater pH, decreases alkalinity and can inhibit the production of shell material. Corrosive water has recently been documented in the northeast Pacific, along with a rapid decline in seawater pH over the past decade. A lack of instrumentation prior to the 1990s means that we have no indication whether these carbon cycle changes have precedence or are a response to recent anthropogenic CO(2 inputs. We analyzed stable carbon and oxygen isotopes (δ(13C, δ(18O of decade-old California mussel shells (Mytilus californianus in the context of an instrumental seawater record of the same length. We further compared modern shells to shells from 1000 to 1340 years BP and from the 1960s to the present and show declines in the δ(13C of modern shells that have no historical precedent. Our finding of decline in another shelled mollusk (limpet and our extensive environmental data show that these δ(13C declines are unexplained by changes to the coastal food web, upwelling regime, or local circulation. Our observed decline in shell δ(13C parallels other signs of rapid changes to the nearshore carbon cycle in the Pacific, including a decline in pH that is an order of magnitude greater than predicted by an equilibrium response to rising atmospheric CO(2, the presence of low pH water throughout the region, and a record of a similarly steep decline in δ(13C in algae in the Gulf of Alaska. These unprecedented changes and the lack of a clear causal variable underscores the need for better quantifying carbon dynamics in nearshore environments.

  20. Assessing the influence of land-use change on the variability of soil ...

    African Journals Online (AJOL)

    The study aimed at providing basis to consider spatial variability in soil fertility to inform effective decision making in mineral fertilizer recommendations. The study area was classified into six land-use categories using a rural rapid appraisal technique with the aid of the farmers in the community, and by remote sensing ...

  1. Evidence that implicit assumptions of 'no evolution' of disease vectors in changing environments can be violated on a rapid timescale.

    Science.gov (United States)

    Egizi, Andrea; Fefferman, Nina H; Fonseca, Dina M

    2015-04-05

    Projected impacts of climate change on vector-borne disease dynamics must consider many variables relevant to hosts, vectors and pathogens, including how altered environmental characteristics might affect the spatial distributions of vector species. However, many predictive models for vector distributions consider their habitat requirements to be fixed over relevant time-scales, when they may actually be capable of rapid evolutionary change and even adaptation. We examine the genetic signature of a spatial expansion by an invasive vector into locations with novel temperature conditions compared to its native range as a proxy for how existing vector populations may respond to temporally changing habitat. Specifically, we compare invasions into different climate ranges and characterize the importance of selection from the invaded habitat. We demonstrate that vector species can exhibit evolutionary responses (altered allelic frequencies) to a temperature gradient in as little as 7-10 years even in the presence of high gene flow, and further, that this response varies depending on the strength of selection. We interpret these findings in the context of climate change predictions for vector populations and emphasize the importance of incorporating vector evolution into models of future vector-borne disease dynamics. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  2. Changes in breathing variables during a 30-minute spontaneous breathing trial.

    Science.gov (United States)

    Figueroa-Casas, Juan B; Connery, Sean M; Montoya, Ricardo

    2015-02-01

    Spontaneous breathing trials (SBTs) are increasingly performed. Significant changes in monitored breathing variables and the timing of those changes during the trial have important implications for its outcome determination and supervision. We aimed to study the magnitude and timing of change in breathing variables during the course of a 30-min SBT. Breathing variables were continuously measured and averaged by minute during the SBT in 32 subjects with trial success and 8 subjects with trial failure from a general ICU population. Percentage changes in breathing variables during the trial and proportions of subjects showing a ≥20% change at different time points relative to the second minute of the trial were calculated. The commonly monitored breathing variables (frequency, tidal volume, their ratio, and minute ventilation) showed median coefficients of variation of <15% throughout the trial and a median change of less than ±20% by the end of the trial. Changes in a detrimental direction of ≥20% at the end of the trial but not already present at 10 min were noted in ≤5% of all subjects. During the course of a 30-min SBT, breathing variables remain relatively constant, and potentially significant changes in these variables after 10 min into the trial are uncommon. These findings should be considered when addressing aspects of duration and supervision of SBTs in weaning protocols. Copyright © 2015 by Daedalus Enterprises.

  3. A hybrid approach to incorporating climate change and variability into climate scenario for impact assessments

    OpenAIRE

    Gebretsadik, Yohannes; Strzepek, Kenneth; Schlosser, C. Adam

    2014-01-01

    Traditional 'delta-change' approach of scenario generation for climate change impact assessment to water resources strongly depends on the selected base-case observed historical climate conditions that the climate shocks are to be super-imposed. This method disregards the combined effect of climate change and the inherent hydro-climatological variability in the system. Here we demonstrated a hybrid uncertainty approach in which uncertainties in historical climate variability are combined with...

  4. Development of Middle Stone Age innovation linked to rapid climate change.

    Science.gov (United States)

    Ziegler, Martin; Simon, Margit H; Hall, Ian R; Barker, Stephen; Stringer, Chris; Zahn, Rainer

    2013-01-01

    The development of modernity in early human populations has been linked to pulsed phases of technological and behavioural innovation within the Middle Stone Age of South Africa. However, the trigger for these intermittent pulses of technological innovation is an enigma. Here we show that, contrary to some previous studies, the occurrence of innovation was tightly linked to abrupt climate change. Major innovational pulses occurred at times when South African climate changed rapidly towards more humid conditions, while northern sub-Saharan Africa experienced widespread droughts, as the Northern Hemisphere entered phases of extreme cooling. These millennial-scale teleconnections resulted from the bipolar seesaw behaviour of the Atlantic Ocean related to changes in the ocean circulation. These conditions led to humid pulses in South Africa and potentially to the creation of favourable environmental conditions. This strongly implies that innovational pulses of early modern human behaviour were climatically influenced and linked to the adoption of refugia.

  5. Changing arctic ecosystems—What is causing the rapid increase of snow geese in northern Alaska?

    Science.gov (United States)

    Hupp, Jerry W.; Ward, David H.; Whalen, Mary E.; Pearce, John M.

    2015-09-10

    Through the Changing Arctic Ecosystems (CAE) initiative, the U.S. Geological Survey (USGS) informs key resource management decisions for Arctic Alaska by providing scientific information on current and future ecosystem response to a warming climate. The Arctic Coastal Plain (ACP) of northern Alaska is a key study area within the USGS CAE initiative. This region has experienced a warming trend over the past decades, leading to decreased sea ice, permafrost thaw, and an advancement of spring phenology. The number of birds on the ACP also is changing, marked by increased populations of the four species of geese that nest in the region. The Snow Goose (Chen caerulescens) is the most rapidly increasing of these species. USGS CAE research is quantifying these changes and their implications for management agencies.

  6. Change in the magnitude and mechanisms of global temperature variability with warming

    Science.gov (United States)

    Brown, Patrick T.; Ming, Yi; Li, Wenhong; Hill, Spencer A.

    2017-10-01

    Natural unforced variability in global mean surface air temperature (GMST) can mask or exaggerate human-caused global warming, and thus a complete understanding of this variability is highly desirable. Significant progress has been made in elucidating the magnitude and physical origins of present-day unforced GMST variability, but it has remained unclear how such variability may change as the climate warms. Here we present modelling evidence that indicates that the magnitude of low-frequency GMST variability is likely to decline in a warmer climate and that its generating mechanisms may be fundamentally altered. In particular, a warmer climate results in lower albedo at high latitudes, which yields a weaker albedo feedback on unforced GMST variability. These results imply that unforced GMST variability is dependent on the background climatological conditions, and thus climate model control simulations run under perpetual pre-industrial conditions may have only limited relevance for understanding the unforced GMST variability of the future.

  7. Specific changes in rapidly transported proteins during regeneration of the goldfish optic nerve.

    Science.gov (United States)

    Benowitz, L I; Shashoua, V E; Yoon, M G

    1981-03-01

    Double labeling methods were used to identify changes in the complement of proteins synthesized in the retinal ganglion cells and transported down the optic nerve during the process of axonal regeneration. Eight to 62 days after goldfish underwent a unilateral optic nerve crush, one eye was labeled with [3H]-, the other with [14C]proline. Control and regenerating optic nerves were dissected out and homogenized together after 5 hr, a time which allowed us to examine selectively membrane-bound components which migrate in the rapid phase of axoplasmic transport. Proteins from the two sides were so-purified and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of the 3H and 14C incorporation patterns along the gels revealed a radical shift away from the normal labeling spectrum during regeneration, with selective changes in labeling at particular molecular weights varying over a 3-fold range. Eight days after crushing the optic nerve, the greatest increases in labeling were seen for material with apparent molecular weights of 24,000 to 27,000, 44,000, and 210,000 daltons. These peaks declined thereafter, and on days 29 to 39, the most prominent increases were at 110,000 to 140,000 daltons. These studies indicate a continuously changing pattern in the synthesis and/or degradation of proteins that are rapidly transported down the optic nerve during regeneration and point to molecular species potential significance in the establishment of the visual map upon the brain.

  8. Modulators of mercury risk to wildlife and humans in the context of rapid global change

    Science.gov (United States)

    Eagles-Smith, Collin A.; Silbergeld, Ellen K.; Basu, Niladri; Bustamante, Paco; Diaz-Barriga, Fernando; Hopkins, William A.; Kidd, Karen A.; Nyland, Jennifer F.

    2018-01-01

    Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.

  9. Specific changes in rapidly transported proteins during regeneration of the goldfish optic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Benowitz, L.I.; Shashoua, V.E.; Yoon, M.G.

    1981-03-01

    Double labeling methods were used to identify changes in the complement of proteins synthesized in the retinal ganglion cells and transported down the optic nerve during the process of axonal regeneration. Eight to 62 days after goldfish underwent a unilateral optic nerve crush, one eye was labeled with (3H)-, the other with (14C)proline. Control and regenerating optic nerves were dissected out and homogenized together after 5 hr, a time which allowed us to examine selectively membrane-bound components which migrate in the rapid phase of axoplasmic transport. Proteins from the two sides were so-purified and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of the 3H and 14C incorporation patterns along the gels revealed a radical shift away from the normal labeling spectrum during regeneration, with selective changes in labeling at particular molecular weights varying over a 3-fold range. Eight days after crushing the optic nerve, the greatest increases in labeling were seen for material with apparent molecular weights of 24,000 to 27,000, 44,000, and 210,000 daltons. These peaks declined thereafter, and on days 29 to 39, the most prominent increases were at 110,000 to 140,000 daltons. These studies indicate a continuously changing pattern in the synthesis and/or degradation of proteins that are rapidly transported down the optic nerve during regeneration and point to molecular species potential significance in the establishment of the visual map upon the brain.

  10. Rapid transgenerational acclimation of a tropical reef fish to climate change

    Science.gov (United States)

    Donelson, J. M.; Munday, P. L.; McCormick, M. I.; Pitcher, C. R.

    2012-01-01

    Understanding the capacity of species to acclimate and adapt to expected temperature increases is critical for making predictions about the biological impacts of global warming, yet it is one of the least certain aspects of climate change science. Tropical species are considered to be especially sensitive to climate change because they live close to their thermal maximum and exhibit limited capacity for acclimation. Here, we demonstrate that a tropical reef fish is highly sensitive to small increases in water temperature, but can rapidly acclimate over multiple generations. Acute exposure to elevated temperatures (+1.5°C and +3.0°C) predicted to occur this century caused a 15% and 30% respective decrease in individual's maximum ability to perform aerobic activities such as swimming or foraging, known as aerobic scope. However, complete compensation in aerobic scope occurred when both parents and offspring were reared throughout their lives at elevated temperature. Such acclimation could reduce the impact of warming temperatures and allow populations to persist across their current range. This study reveals the importance of transgenerational acclimation as a mechanism for coping with rapid climate change and highlights that single generation studies risk underestimating the potential of species to cope.

  11. Comparing records to understand past rapid climate change: An INTIMATE database update

    Science.gov (United States)

    Kearney, Rebecca; Bronk Ramsey, Christopher; Staff, Richard A.; Albert, Paul G.

    2017-04-01

    Integrating multi-proxy records from ice, terrestrial and marine records enhances the understanding of the temporal and spatial variation of past rapid climatic changes globally. By handling these records on their own individual timescales and linking them through known chronological relationships (e.g. tephra, 10Be and 14C), regional comparisons can be made for these past climatic events. Furthermore, the use of time-transfer functions enables the chronological uncertainties between different archives to be quantified. The chronological database devised by the working group 1 (WG1) of INTIMATE, exclusively uses this methodology to provide a means to visualise and compare palaeoclimate records. Development of this database is ongoing, with numerous additional records being added to the database with a particular focus on European archives spanning the Late Glacial period. Here we present a new phase of data collection. Through selected cases study sites across Europe, we aim to illustrate the database as a novel tool in understanding spatial and temporal variations in rapid climatic change. Preliminary results allow questions such as time transgression and regional expressions of rapid climate change to be investigated. The development of this database will continue through additional input of raw climate proxy data, linking to other relevant databases (e.g. Fossil Pollen Database) and providing output data that can be analysed in the statistical programming language of R. A major goal of this work to is not only provide a detailed database, but allow researchers to integrate their own climate proxy data with that on the database.

  12. Neurogenomics and the role of a large mutational target on rapid behavioral change.

    Science.gov (United States)

    Stanley, Craig E; Kulathinal, Rob J

    2016-11-08

    Behavior, while complex and dynamic, is among the most diverse, derived, and rapidly evolving traits in animals. The highly labile nature of heritable behavioral change is observed in such evolutionary phenomena as the emergence of converged behaviors in domesticated animals, the rapid evolution of preferences, and the routine development of ethological isolation between diverging populations and species. In fact, it is believed that nervous system development and its potential to evolve a seemingly infinite array of behavioral innovations played a major role in the successful diversification of metazoans, including our own human lineage. However, unlike other rapidly evolving functional systems such as sperm-egg interactions and immune defense, the genetic basis of rapid behavioral change remains elusive. Here we propose that the rapid divergence and widespread novelty of innate and adaptive behavior is primarily a function of its genomic architecture. Specifically, we hypothesize that the broad diversity of behavioral phenotypes present at micro- and macroevolutionary scales is promoted by a disproportionately large mutational target of neurogenic genes. We present evidence that these large neuro-behavioral targets are significant and ubiquitous in animal genomes and suggest that behavior's novelty and rapid emergence are driven by a number of factors including more selection on a larger pool of variants, a greater role of phenotypic plasticity, and/or unique molecular features present in large genes. We briefly discuss the origins of these large neurogenic genes, as they relate to the remarkable diversity of metazoan behaviors, and highlight key consequences on both behavioral traits and neurogenic disease across, respectively, evolutionary and ontogenetic time scales. Current approaches to studying the genetic mechanisms underlying rapid phenotypic change primarily focus on identifying signatures of Darwinian selection in protein-coding regions. In contrast

  13. Response of tropical sea surface temperature, precipitation, and tropical cyclone-related variables to changes in global and local forcing

    Science.gov (United States)

    Emanuel, Kerry; Sobel, Adam

    2013-06-01

    A single-column model is used to estimate the equilibrium response of sea surface temperature (SST), precipitation, and several variables related to tropical cyclone (TC) activity to changes in both local and global forcing. Response to local forcing is estimated using the weak temperature gradient (WTG) approximation. The surface temperature is calculated using a thin slab ocean so as to maintain surface energy balance. Forcing is varied by changing the solar constant, atmospheric CO2 concentration, surface wind speed, and the convergence of upper ocean heat flux. These experiments show that precipitation and variables related to TC activity are not unique functions of SST on time scales long enough for surface energy balance to be maintained. Precipitation varies inversely with SST in experiments in which the surface wind speed is varied. At low wind speed, the WTG experiments reveal a regime of high relative SST and low precipitation, which is maintained by increased transmission of longwave radiation from the surface directly to space through a dry troposphere. In general, TC potential intensity and genesis potential vary much more rapidly with SST in response to varying surface wind speed than in response to other forcings. Local changes in TC potential intensity are highly correlated with local changes in SST, showing that relative SST is a good proxy for potential intensity when forcing is strictly local, but it cannot capture potentially important changes in potential intensity that arise from global-scale changes in forcing.

  14. Space-time variability of floods across Germany: Gradual trends, step changes and fluctuations

    Science.gov (United States)

    Merz, Bruno; Vorogushyn, Sergiy; Viet Dung, Nguyen; Schröter, Kai

    2015-04-01

    The space-time variability of flood magnitude and frequency across Germany at the interannual and decadal time scale is analyzed and interpreted. The analyses are based on flood time series of 68 catchments for a joint period of 74 years. The catchments are distributed across Germany and show different flood regimes. Different statistical tests are applied to investigate different types of flood changes: gradual trends, step changes and fluctuations. In addition, changes in the mean behavior and in the variability are studied. A focus is placed on the spatial stability of changes, i.e. answering the question to which extent flood changes are coherent across Germany. The joint analysis of changes for a large number of catchments allows interpreting the causes of the observed changes. For instance, climate-related flood changes are expected to show a different behavior than changes caused by river training or land-use change.

  15. Wiki management a revolutionary new model for a rapidly changing and collaborative world

    CERN Document Server

    Collins, Rod

    2013-01-01

    We now live in a "wiki" world where mass collaboration is not only possible-it's often the best solution. Conventional management thought assumes that command-and-control is the most effective way to organize the efforts of large numbers of people, but rapid change and increasing complexity have rendered that model obsolete. As a result, most managers today lack the skills and knowledge needed to succeed in an age when networks are proving smarter and faster than hierarchies. Designing organizations for mass collaboration demands a new and very different model-wiki management.

  16. Experiences of Families Transmitting Values in a Rapidly Changing Society: Implications for Family Therapists.

    Science.gov (United States)

    Akyil, Yudum; Prouty, Anne; Blanchard, Amy; Lyness, Kevin

    2016-06-01

    Intergenerational value transmission affects parent-child relationships and necessitates constant negotiation in families. Families with adolescents from rapidly changing societies face unique challenges in balancing the traditional collectivistic family values that promote harmony with emerging values that promote autonomy. Using modern Turkey as an example of such a culture, the authors examine the transmission process in families that hold more traditional and collectivistic values than their adolescent children. Special consideration is given to generational and cultural differences in the autonomy and relatedness dimensions. © 2015 Family Process Institute.

  17. Rapid gene expression changes in peripheral blood lymphocytes upon practice of a comprehensive yoga program.

    Science.gov (United States)

    Qu, Su; Olafsrud, Solveig Mjelstad; Meza-Zepeda, Leonardo A; Saatcioglu, Fahri

    2013-01-01

    One of the most common integrative medicine (IM) modalities is yoga and related practices. Previous work has shown that yoga may improve wellness in healthy people and have benefits for patients. However, the mechanisms of how yoga may positively affect the mind-body system are largely unknown. Here we have assessed possible rapid changes in global gene expression profiles in the peripheral blood mononuclear cells (PBMCs) in healthy people that practiced either a comprehensive yoga program or a control regimen. The experimental sessions included gentle yoga postures, breathing exercises, and meditation (Sudarshan Kriya and Related Practices--SK&P) compared with a control regimen of a nature walk and listening to relaxing music. We show that the SK&P program has a rapid and significantly greater effect on gene expression in PBMCs compared with the control regimen. These data suggest that yoga and related practices result in rapid gene expression alterations which may be the basis for their longer term cell biological and higher level health effects.

  18. Rapid gene expression changes in peripheral blood lymphocytes upon practice of a comprehensive yoga program.

    Directory of Open Access Journals (Sweden)

    Su Qu

    Full Text Available One of the most common integrative medicine (IM modalities is yoga and related practices. Previous work has shown that yoga may improve wellness in healthy people and have benefits for patients. However, the mechanisms of how yoga may positively affect the mind-body system are largely unknown. Here we have assessed possible rapid changes in global gene expression profiles in the peripheral blood mononuclear cells (PBMCs in healthy people that practiced either a comprehensive yoga program or a control regimen. The experimental sessions included gentle yoga postures, breathing exercises, and meditation (Sudarshan Kriya and Related Practices--SK&P compared with a control regimen of a nature walk and listening to relaxing music. We show that the SK&P program has a rapid and significantly greater effect on gene expression in PBMCs compared with the control regimen. These data suggest that yoga and related practices result in rapid gene expression alterations which may be the basis for their longer term cell biological and higher level health effects.

  19. Recovery trajectories of kelp forest animals are rapid yet spatially variable across a network of temperate marine protected areas

    Science.gov (United States)

    Caselle, Jennifer E.; Rassweiler, Andrew; Hamilton, Scott L.; Warner, Robert R.

    2015-09-01

    Oceans currently face a variety of threats, requiring ecosystem-based approaches to management such as networks of marine protected areas (MPAs). We evaluated changes in fish biomass on temperate rocky reefs over the decade following implementation of a network of MPAs in the northern Channel Islands, California. We found that the biomass of targeted (i.e. fished) species has increased consistently inside all MPAs in the network, with an effect of geography on the strength of the response. More interesting, biomass of targeted fish species also increased outside MPAs, although only 27% as rapidly as in the protected areas, indicating that redistribution of fishing effort has not severely affected unprotected populations. Whether the increase outside of MPAs is due to changes in fishing pressure, fisheries management actions, adult spillover, favorable environmental conditions, or a combination of all four remains unknown. We evaluated methods of controlling for biogeographic or environmental variation across networks of protected areas and found similar performance of models incorporating empirical sea surface temperature versus a simple geographic blocking term based on assemblage structure. The patterns observed are promising indicators of the success of this network, but more work is needed to understand how ecological and physical contexts affect MPA performance.

  20. Recovery trajectories of kelp forest animals are rapid yet spatially variable across a network of temperate marine protected areas.

    Science.gov (United States)

    Caselle, Jennifer E; Rassweiler, Andrew; Hamilton, Scott L; Warner, Robert R

    2015-09-16

    Oceans currently face a variety of threats, requiring ecosystem-based approaches to management such as networks of marine protected areas (MPAs). We evaluated changes in fish biomass on temperate rocky reefs over the decade following implementation of a network of MPAs in the northern Channel Islands, California. We found that the biomass of targeted (i.e. fished) species has increased consistently inside all MPAs in the network, with an effect of geography on the strength of the response. More interesting, biomass of targeted fish species also increased outside MPAs, although only 27% as rapidly as in the protected areas, indicating that redistribution of fishing effort has not severely affected unprotected populations. Whether the increase outside of MPAs is due to changes in fishing pressure, fisheries management actions, adult spillover, favorable environmental conditions, or a combination of all four remains unknown. We evaluated methods of controlling for biogeographic or environmental variation across networks of protected areas and found similar performance of models incorporating empirical sea surface temperature versus a simple geographic blocking term based on assemblage structure. The patterns observed are promising indicators of the success of this network, but more work is needed to understand how ecological and physical contexts affect MPA performance.

  1. Changes in head posture after rapid maxillary expansion in patients with nasopharyngeal obstruction

    Directory of Open Access Journals (Sweden)

    Kjurchieva-Chuchkova G

    2016-09-01

    Full Text Available Introduction: Nasopharyngeal obstruction is an important etiologic factor in the development of an extreme vertical growth facial pattern, and insufficient transversal growth of the maxilla. The treatment outcomes associated with rapid maxillary expansion in the literature are mainly discussed in terms of changes in dentofacial morphology, without special reference to changes in the pharyngeal airway, the position of the mandible, hyoid bone and the tongue. Aim: The aim of this study was to evaluate the effects of rapid maxillary expansion (RME, on changes in head posture and airway dimension. Materials and methods: The cephalometric evaluation was conducted on thirty lateral cephalograms of patients with nasopharyngeal obstruction (mean age 9.11 years; standard deviation (SD ± 2.0; range 8-14 years treated with appliance for rapid maxillary expansion. Patients were randomly divided into two groups: 1 study group comprised of 15 patients treated with RME immediately after the first visit; 2 a control group comprised of 15 subjects monitored for approximately 12 months prior to commencing therapy, who became untreated controls. Lateral cephalograms, taken in the natural head position, were obtained at the first visit and 6 months later for all subjects. Six angular measurements were measured to describe craniocervical angulation, and five linear measurements were measured to describe airway dimension. Results: The investigated group treated with RME shows a statistically significant decrease in craniocervical angulation, especially at the angle of interaction between palatal plane and the tangent odontoid processus (4.07 degrees, for PP/OPT angle and angle interaction between palatal plane and the tangent of cervical vertebra (4.95 degrees for PP/CVT angle. Airway dimension in the treated group increased, especially at the levels PNS-ad1 (2.52 mm, ve-pve (2.97 mm, and uv-puv (2.88 mm. No significant changes were observed in the control group

  2. Amplification and dampening of soil respiration by changes in temperature variability

    Science.gov (United States)

    C.A. Sierra; M.E. Harmon; E.A. Thomann; S.S. Perakis; H.W. Loescher

    2011-01-01

    Accelerated release of carbon from soils is one of the most important feedbacks related to anthropogenically induced climate change. Studies addressing the mechanisms for soil carbon release through organic matter decomposition have focused on the effect of changes in the average temperature, with little attention to changes in temperature variability. Anthropogenic...

  3. Changes of pulp-chamber dimensions 1 year after rapid maxillary expansion.

    Science.gov (United States)

    Baratieri, Carolina; Alves, Matheus; Mattos, Cláudia Trindade; Souza, Margareth Maria Gomes de; Ruellas, Antônio Carlos de Oliveira

    2013-04-01

    The purpose of this study was to examine the effect of orthopedic forces on maxillary first molars' and maxillary central incisors' pulp chambers in children having rapid maxillary expansion as the only intervention compared with children having no orthodontic intervention by using cone-beam computed tomography images. In this prospective controlled clinical study, we evaluated 60 maxillary first molars and 60 maxillary central incisors from 30 children (18 boys, 12 girls) in the mixed dentition and during the pubertal growth period. The treated group had rapid maxillary expansion with the Haas expander, followed by 6 months of retention and 6 months of follow-up out of retention; the control group had no intervention during the study. Cone-beam computed tomography scans were taken initially and 1 year after the rapid maxillary expansion active phase. Initially, a 3-dimensional scrolling in all pulp chambers of the evaluated teeth was performed with Dolphin Imaging software (version 11.0; Dolphin Imaging & Management Solutions, Chatsworth, Calif) to describe the incidence of pulp-chamber calcifications. The dimensions of the pulp chambers of the molars and incisors were also investigated. Cross-sectional and longitudinal slices were used for each molar (coronal and axial slices) and incisor (sagittal and axial slices). The area (mm(2)) was obtained from 3 slices of each kind (6 measurements for each tooth). The results suggest that rapid maxillary expansion did not induce new pulp-chamber calcification. Also, it did not interfere in normal pulp-chamber dimension changes of the anchorage molars. The pulp chamber of the central incisors can be expected to be minimally wider 1 year after the therapy. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  4. Ecological Pleiotropy Suppresses the Dynamic Feedback Generated by a Rapidly Changing Trait.

    Science.gov (United States)

    DeLong, John P

    2017-05-01

    Population dynamics may carry a signature of an ecology-evolution-ecology feedback, known as eco-evolutionary dynamics, when functionally important traits change. Given current theory, the absence of a feedback from a trait with strong links to species interactions should not occur. In a previous study with the Didinium-Paramecium predator-prey system, however, rapid and large-magnitude changes in predator cell volume occurred without any noticeable effect on the population dynamics. Here I resolve this theory-data conflict by showing that ecological pleiotropy-when a trait has more than one functional effect on an ecological process-suppresses shifts in dynamics that would arise, given the links between cell volume and the species interaction. Whether eco-evolutionary dynamics arise, therefore, depends not just on the ecology-evolution feedback but on the net effect that a trait has on different parts of the underlying interaction.

  5. Effects of climate change and variability on population dynamics in a long-lived shorebird

    NARCIS (Netherlands)

    van de Pol, Martijn; Vindenes, Yngvild; Saether, Bernt-Erik; Engen, Steinar; Ens, Bruno J.; Oosterbeek, Kees; Tinbergen, Joost M.

    Climate change affects both the mean and variability of climatic variables, but their relative impact on the dynamics of populations is still largely unexplored. Based on a long-term study of the demography of a declining Eurasian Oystercatcher (Haematopus ostralegus) population, we quantify the

  6. Rapid directional change degrades GPS distance measurement validity during intermittent intensity running.

    Directory of Open Access Journals (Sweden)

    Jonathan C Rawstorn

    Full Text Available Use of the Global Positioning System (GPS for quantifying athletic performance is common in many team sports. The effect of running velocity on measurement validity is well established, but the influence of rapid directional change is not well understood in team sport applications. This effect was systematically evaluated using multidirectional and curvilinear adaptations of a validated soccer simulation protocol that maintained identical velocity profiles. Team sport athletes completed 90 min trials of the Loughborough Intermittent Shuttle-running Test movement pattern on curvilinear, and multidirectional shuttle running tracks while wearing a 5 Hz (with interpolated 15 Hz output GPS device. Reference total distance (13 200 m was systematically over- and underestimated during curvilinear (2.61±0.80% and shuttle (-3.17±2.46% trials, respectively. Within-epoch measurement uncertainty dispersion was widest during the shuttle trial, particularly during the jog and run phases. Relative measurement reliability was excellent during both trials (Curvilinear r = 1.00, slope = 1.03, ICC = 1.00; Shuttle r = 0.99, slope = 0.97, ICC = 0.99. Absolute measurement reliability was superior during the curvilinear trial (Curvilinear SEM = 0 m, CV = 2.16%, LOA ± 223 m; Shuttle SEM = 119 m, CV = 2.44%, LOA ± 453 m. Rapid directional change degrades the accuracy and absolute reliability of GPS distance measurement, and caution is recommended when using GPS to quantify rapid multidirectional movement patterns.

  7. Forests and trees for social adaptation to climate variability and change

    NARCIS (Netherlands)

    Pramova, E.; Locatelli, B.; Djoudi, H.; Somorin, O.A.

    2012-01-01

    Ecosystems provide important services that can help people adapt to climate variability and change. Recognizing this role of ecosystems, several international and nongovernmental organizations have promoted an ecosystem-based approach to adaptation. We review the scientific literature related to

  8. Climate change/variability science and adaptive strategies for state and regional transportation decision making.

    Science.gov (United States)

    2010-04-01

    The objective of this study was to generate a baseline understanding of current policy responses to climate : change/variability at the state and regional transportation-planning and -decision levels. Specifically, : researchers were interested in th...

  9. Health Systems Research in a Complex and Rapidly Changing Context: Ethical Implications of Major Health Systems Change at Scale.

    Science.gov (United States)

    MacGregor, Hayley; Bloom, Gerald

    2016-12-01

    This paper discusses health policy and systems research in complex and rapidly changing contexts. It focuses on ethical issues at stake for researchers working with government policy makers to provide evidence to inform major health systems change at scale, particularly when the dynamic nature of the context and ongoing challenges to the health system can result in unpredictable outcomes. We focus on situations where 'country ownership' of HSR is relatively well established and where there is significant involvement of local researchers and close ties and relationships with policy makers are often present. We frame our discussion around two country case studies with which we are familiar, namely China and South Africa and discuss the implications for conducting 'embedded' research. We suggest that reflexivity is an important concept for health system researchers who need to think carefully about positionality and their normative stance and to use such reflection to ensure that they can negotiate to retain autonomy, whilst also contributing evidence for health system change. A research process informed by the notion of reflexive practice and iterative learning will require a longitudinal review at key points in the research timeline. Such review should include the convening of a deliberative process and should involve a range of stakeholders, including those most likely to be affected by the intended and unintended consequences of change. © 2016 The Authors Developing World Bioethics Published by John Wiley & Sons Ltd.

  10. Short-term evaluation of tegumentary changes of the nose in oral breathers undergoing rapid maxillary expansion.

    Science.gov (United States)

    Badreddine, Fauze Ramez; Fujita, Reginaldo Raimundo; Cappellette, Mario

    2017-06-26

    Rapid maxillary expansion is an orthodontic and orthopedic procedure that can change the form and function of the nose. The soft tissue of the nose and its changes can influence the esthetics and the stability of the results obtained by this procedure. The objective of this study was to assess the changes in nose dimensions after rapid maxillary expansion (RME) in oral breathers with maxillary atresia, using a reliable and reproducible methodology through computed tomography. A total of 30 mouth-breathing patients with maxillary atresia were analyzed and divided into a treatment group who underwent RME (20 patients, 10 of which were male and 10 female, with a MA of 8.9 years and a SD of 2.16, ranging from 6.5 to 12.5 years) and a Control Group (10 patients, 5 of which were male and 5 female, with a MA of 9.2 years, SD of 2.17, ranging from 6.11 to 13.7 years). In the treatment group, multislice computed tomography scans were obtained at the start of the treatment (T1) and 3 months after expansion (T2). The patients of the control group were submitted to the same exams at the same intervals of time. Four variables related to soft tissue structures of the nose were analyzed (alar base width, alar width, height of soft tissue of the nose and length of soft tissue of the nose), and the outcomes between T1 and T2 were compared using Osirix MD software. In the TG, the soft tissues of the nose exhibited significant increases in all variables studied (p0.05). In the treatment group, mean alar base width increased by 4.87% (p=0.004), mean alar width increased by 4.04% (p=0.004), mean height of the soft tissues of the nose increased by 4.84% (p=0.003) and mean length of the soft tissues of the nose increased by 4.29% (p=0.012). In short-term, RME provided a statistically significant increase in the dimensions of the soft tissues of the nose. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All

  11. Wildlife health in a rapidly changing North: focus on avian disease

    Science.gov (United States)

    Van Hemert, Caroline R.; Pearce, John M.; Handel, Colleen M.

    2014-01-01

    Climate-related environmental changes have increasingly been linked to emerging infectious diseases in wildlife. The Arctic is facing a major ecological transition that is expected to substantially affect animal and human health. Changes in phenology or environmental conditions that result from climate warming may promote novel species assemblages as host and pathogen ranges expand to previously unoccupied areas. Recent evidence from the Arctic and subarctic suggests an increase in the spread and prevalence of some wildlife diseases, but baseline data necessary to detect and verify such changes are still lacking. Wild birds are undergoing rapid shifts in distribution and have been implicated in the spread of wildlife and zoonotic diseases. Here, we review evidence of current and projected changes in the abundance and distribution of avian diseases and outline strategies for future research. We discuss relevant climatic and environmental factors, emerging host–pathogen contact zones, the relationship between host condition and immune function, and potential wildlife and human health outcomes in northern regions.

  12. Rapid Changes in Cortical and Subcortical Brain Regions after Early Bilateral Enucleation in the Mouse.

    Directory of Open Access Journals (Sweden)

    Olga O Kozanian

    Full Text Available Functional sensory and motor areas in the developing mammalian neocortex are formed through a complex interaction of cortically intrinsic mechanisms, such as gene expression, and cortically extrinsic mechanisms such as those mediated by thalamic input from the senses. Both intrinsic and extrinsic mechanisms are believed to be involved in cortical patterning and the establishment of areal boundaries in early development; however, the nature of the interaction between intrinsic and extrinsic processes is not well understood. In a previous study, we used a perinatal bilateral enucleation mouse model to test some aspects of this interaction by reweighting sensory input to the developing cortex. Visual deprivation at birth resulted in a shift of intraneocortical connections (INCs that aligned with ectopic ephrin A5 expression in the same location ten days later at postnatal day (P 10. A prevailing question remained: Does visual deprivation first induce a change in gene expression, followed by a shift in INCs, or vice versa? In the present study, we address this question by investigating the neuroanatomy and patterns of gene expression in post-natal day (P 1 and 4 mice following bilateral enucleation at birth. Our results demonstrate a rapid reduction in dorsal lateral geniculate nucleus (dLGN size and ephrin A5 gene expression 24-hours post-enucleation, with more profound effects apparent at P4. The reduced nuclear size and diminished gene expression mirrors subtle changes in ephrin A5 expression evident in P1 and P4 enucleated neocortex, 11 and 8 days prior to natural eye opening, respectively. Somatosensory and visual INCs were indistinguishable between P1 and P4 mice bilaterally enucleated at birth, indicating that perinatal bilateral enucleation initiates a rapid change in gene expression (within one day followed by an alteration of sensory INCs later on (second postnatal week. With these results, we gain a deeper understanding of how gene

  13. Global variability and changes in ocean total alkalinity from Aquarius satellite data

    Science.gov (United States)

    Fine, Rana A.; Willey, Debra A.; Millero, Frank J.

    2017-01-01

    This work demonstrates how large-scale Aquarius satellite salinity data have provided an unprecedented opportunity when combined with total alkalinity (TA) equations as a function of salinity and temperature to examine global changes in the CO2 system. Alkalinity is a gauge on the ability of seawater to neutralize acids. TA correlates strongly with salinity. Spatial variability in alkalinity and salinity exceed temporal variability. Northern Hemisphere has more spatial variability in TA and salinity, while less variability in Southern Ocean TA is due to less salinity variability and upwelling of waters enriched in alkalinity. For the first time it is shown that TA in subtropical regions has increased as compared with climatological data; this is reflective of large-scale changes in the global water cycle. Thus, as temperature and salinity increase in subtropical regions, the resultant increase in TA and ocean acidification is reinforcing that from oceanic uptake of atmospheric CO2.

  14. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot

    NARCIS (Netherlands)

    Schut, A.G.T.; Wardell-Johnson, G.W.; Yates, C.J.; Keppel, G.; Baran, I.; Franklin, S.E.; Hopper, S.D.; Niel, Van K.P.; Mucina, L.; Byrne, M.

    2014-01-01

    Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs) provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic

  15. Rapid Land Cover Map Updates Using Change Detection and Robust Random Forest Classifiers

    Directory of Open Access Journals (Sweden)

    Konrad J. Wessels

    2016-10-01

    Full Text Available The paper evaluated the Landsat Automated Land Cover Update Mapping (LALCUM system designed to rapidly update a land cover map to a desired nominal year using a pre-existing reference land cover map. The system uses the Iteratively Reweighted Multivariate Alteration Detection (IRMAD to identify areas of change and no change. The system then automatically generates large amounts of training samples (n > 1 million in the no-change areas as input to an optimized Random Forest classifier. Experiments were conducted in the KwaZulu-Natal Province of South Africa using a reference land cover map from 2008, a change mask between 2008 and 2011 and Landsat ETM+ data for 2011. The entire system took 9.5 h to process. We expected that the use of the change mask would improve classification accuracy by reducing the number of mislabeled training data caused by land cover change between 2008 and 2011. However, this was not the case due to exceptional robustness of Random Forest classifier to mislabeled training samples. The system achieved an overall accuracy of 65%–67% using 22 detailed classes and 72%–74% using 12 aggregated national classes. “Water”, “Plantations”, “Plantations—clearfelled”, “Orchards—trees”, “Sugarcane”, “Built-up/dense settlement”, “Cultivation—Irrigated” and “Forest (indigenous” had user’s accuracies above 70%. Other detailed classes (e.g., “Low density settlements”, “Mines and Quarries”, and “Cultivation, subsistence, drylands” which are required for operational, provincial-scale land use planning and are usually mapped using manual image interpretation, could not be mapped using Landsat spectral data alone. However, the system was able to map the 12 national classes, at a sufficiently high level of accuracy for national scale land cover monitoring. This update approach and the highly automated, scalable LALCUM system can improve the efficiency and update rate of regional land

  16. Cone-beam computed tomography evaluation of dentoskeletal changes after asymmetric rapid maxillary expansion.

    Science.gov (United States)

    Baka, Zeliha Muge; Akin, Mehmet; Ucar, Faruk Izzet; Ileri, Zehra

    2015-01-01

    The aims of this study were to quantitatively evaluate the changes in arch widths and buccolingual inclinations of the posterior teeth after asymmetric rapid maxillary expansion (ARME) and to compare the measurements between the crossbite and the noncrossbite sides with cone-beam computed tomography (CBCT). From our clinic archives, we selected the CBCT records of 30 patients with unilateral skeletal crossbite (13 boys, 14.2 ± 1.3 years old; 17 girls, 13.8 ± 1.3 years old) who underwent ARME treatment. A modified acrylic bonded rapid maxillary expansion appliance including an occlusal locking mechanism was used in all patients. CBCT records had been taken before ARME treatment and after a 3-month retention period. Fourteen angular and 80 linear measurements were taken for the maxilla and the mandible. Frontally clipped CBCT images were used for the evaluation. Paired sample and independent sample t tests were used for statistical comparisons. Comparisons of the before-treatment and after-retention measurements showed that the arch widths and buccolingual inclinations of the posterior teeth increased significantly on the crossbite side of the maxilla and on the noncrossbite side of the mandible (P ARME treatment, the crossbite side of the maxilla and the noncrossbite side of the mandible were more affected than were the opposite sides. Copyright © 2015. Published by Elsevier Inc.

  17. Amplification and dampening of soil respiration by changes in temperature variability

    Directory of Open Access Journals (Sweden)

    C. A. Sierra

    2011-04-01

    Full Text Available Accelerated release of carbon from soils is one of the most important feedbacks related to anthropogenically induced climate change. Studies addressing the mechanisms for soil carbon release through organic matter decomposition have focused on the effect of changes in the average temperature, with little attention to changes in temperature variability. Anthropogenic activities are likely to modify both the average state and the variability of the climatic system; therefore, the effects of future warming on decomposition should not only focus on trends in the average temperature, but also variability expressed as a change of the probability distribution of temperature. Using analytical and numerical analyses we tested common relationships between temperature and respiration and found that the variability of temperature plays an important role determining respiration rates of soil organic matter. Changes in temperature variability, without changes in the average temperature, can affect the amount of carbon released through respiration over the long-term. Furthermore, simultaneous changes in the average and variance of temperature can either amplify or dampen the release of carbon through soil respiration as climate regimes change. These effects depend on the degree of convexity of the relationship between temperature and respiration and the magnitude of the change in temperature variance. A potential consequence of this effect of variability would be higher respiration in regions where both the mean and variance of temperature are expected to increase, such as in some low latitude regions; and lower amounts of respiration where the average temperature is expected to increase and the variance to decrease, such as in northern high latitudes.

  18. Interactions of Mean Climate Change and Climate Variability on Food Security Extremes

    Science.gov (United States)

    Ruane, Alexander C.; McDermid, Sonali; Mavromatis, Theodoros; Hudson, Nicholas; Morales, Monica; Simmons, John; Prabodha, Agalawatte; Ahmad, Ashfaq; Ahmad, Shakeel; Ahuja, Laj R.

    2015-01-01

    Recognizing that climate change will affect agricultural systems both through mean changes and through shifts in climate variability and associated extreme events, we present preliminary analyses of climate impacts from a network of 1137 crop modeling sites contributed to the AgMIP Coordinated Climate-Crop Modeling Project (C3MP). At each site sensitivity tests were run according to a common protocol, which enables the fitting of crop model emulators across a range of carbon dioxide, temperature, and water (CTW) changes. C3MP can elucidate several aspects of these changes and quantify crop responses across a wide diversity of farming systems. Here we test the hypothesis that climate change and variability interact in three main ways. First, mean climate changes can affect yields across an entire time period. Second, extreme events (when they do occur) may be more sensitive to climate changes than a year with normal climate. Third, mean climate changes can alter the likelihood of climate extremes, leading to more frequent seasons with anomalies outside of the expected conditions for which management was designed. In this way, shifts in climate variability can result in an increase or reduction of mean yield, as extreme climate events tend to have lower yield than years with normal climate.C3MP maize simulations across 126 farms reveal a clear indication and quantification (as response functions) of mean climate impacts on mean yield and clearly show that mean climate changes will directly affect the variability of yield. Yield reductions from increased climate variability are not as clear as crop models tend to be less sensitive to dangers on the cool and wet extremes of climate variability, likely underestimating losses from water-logging, floods, and frosts.

  19. Decrease Heart Rate Variability But Preserve Postural Blood Pressure Change in Type 2 Diabetes with Microalbuminuria

    Directory of Open Access Journals (Sweden)

    Harn-Shen Chen

    2006-06-01

    Conclusion: Type 2 diabetic patients with microalbuminuria have diminished heart rate variability in response to deep breathing, change of position and the Valsalva maneuver, but they preserve BP response to postural change. Therefore, microalbuminuria seems to be associated with early DAN, but not with advanced DAN.

  20. Exploiting temporal variability to understand tree recruitment response to climate change

    Science.gov (United States)

    Ines Ibanez; James S. Clark; Shannon LaDeau; Janneke Hill Ris Lambers

    2007-01-01

    Predicting vegetation shifts under climate change is a challenging endeavor, given the complex interactions between biotic and abiotic variables that influence demographic rates. To determine how current trends and variation in climate change affect seedling establishment, we analyzed demographic responses to spatiotemporal variation to temperature and soil moisture in...

  1. Land change variability and human-environment dynamics in the United States Great Plains

    Science.gov (United States)

    Drummond, Mark A.; Auch, Roger F.; Karstensen, Krista A.; Sayler, Kristi L.; Taylor, Janis L.; Loveland, Thomas R.

    2012-01-01

    Land use and land cover changes have complex linkages to climate variability and change, biophysical resources, and socioeconomic driving forces. To assess these land change dynamics and their causes in the Great Plains, we compare and contrast contemporary changes across 16 ecoregions using Landsat satellite data and statistical analysis. Large-area change analysis of agricultural regions is often hampered by change detection error and the tendency for land conversions to occur at the local-scale. To facilitate a regional-scale analysis, a statistical sampling design of randomly selected 10 km × 10 km blocks is used to efficiently identify the types and rates of land conversions for four time intervals between 1973 and 2000, stratified by relatively homogenous ecoregions. Nearly 8% of the overall Great Plains region underwent land-use and land-cover change during the study period, with a substantial amount of ecoregion variability that ranged from less than 2% to greater than 13%. Agricultural land cover declined by more than 2% overall, with variability contingent on the differential characteristics of regional human–environment systems. A large part of the Great Plains is in relatively stable land cover. However, other land systems with significant biophysical and climate limitations for agriculture have high rates of land change when pushed by economic, policy, technology, or climate forcing factors. The results indicate the regionally based potential for land cover to persist or fluctuate as land uses are adapted to spatially and temporally variable forcing factors.

  2. Capturing subregional variability in regional-scale climate change vulnerability assessments of natural resources

    Science.gov (United States)

    Polly C. Buotte; David L. Peterson; Kevin S. McKelvey; Jeffrey A. Hicke

    2016-01-01

    Natural resource vulnerability to climate change can depend on the climatology and ecological conditions at a particular site. Here we present a conceptual framework for incorporating spatial variability in natural resource vulnerability to climate change in a regional-scale assessment. The framework was implemented in the first regional-scale vulnerability...

  3. Changes in frequency of premature complexes and heart rate variability related to shift work

    NARCIS (Netherlands)

    Amelsvoort, van L.G.P.M.; Schouten, E.G.; Maan, A.C.; Swenne, C.A.; Kok, F.J.

    2001-01-01

    OBJECTIVES To investigate whether an increased risk of cardiovascular disease might be caused by increased arrhythmogeneity and by unfavourable changes in autonomic cardiac control the changes in the occurrence of premature complexes (PVCs) and in heart rate variability (HRV) were studied in

  4. Using life-history traits to explain bird population responses to changing weather variability

    NARCIS (Netherlands)

    Cormont, A.; Vos, C.C.; Turnhout, van C.A.M.; Foppen, R.P.B.; Braak, ter C.J.F.

    2011-01-01

    Bird population dynamics are expected to change in response to increased weather variability, an expression of climate change. The extent to which species are sensitive to effects of weather on survival and reproduction depends on their life-history traits. We investigated how breeding bird species

  5. Screening variability and change of soil moisture under wide-ranging climate conditions: Snow dynamics effects.

    Science.gov (United States)

    Verrot, Lucile; Destouni, Georgia

    2015-01-01

    Soil moisture influences and is influenced by water, climate, and ecosystem conditions, affecting associated ecosystem services in the landscape. This paper couples snow storage-melting dynamics with an analytical modeling approach to screening basin-scale, long-term soil moisture variability and change in a changing climate. This coupling enables assessment of both spatial differences and temporal changes across a wide range of hydro-climatic conditions. Model application is exemplified for two major Swedish hydrological basins, Norrström and Piteälven. These are located along a steep temperature gradient and have experienced different hydro-climatic changes over the time period of study, 1950-2009. Spatially, average intra-annual variability of soil moisture differs considerably between the basins due to their temperature-related differences in snow dynamics. With regard to temporal change, the long-term average state and intra-annual variability of soil moisture have not changed much, while inter-annual variability has changed considerably in response to hydro-climatic changes experienced so far in each basin.

  6. Variability and long-term change in Australian temperature and precipitation extremes

    Directory of Open Access Journals (Sweden)

    Dörte Jakob

    2016-12-01

    We conclude that in assessing the likelihood of climate hazards, one needs to consider the modulation of climate extremes due to both long-term change and climate variability. Our findings imply that when planning for adaptation, different emphasis needs to be given to changing temperature and precipitation extremes.

  7. Rapid warming of the world's lakes: Interdecadal variability and long-term trends from 1910-2009 using in situ and remotely sensed data

    Science.gov (United States)

    Lenters, J. D.; Read, J. S.; Sharma, S.; O'Reilly, C.; Hampton, S. E.; Gray, D.; McIntyre, P. B.; Hook, S. J.; Schneider, P.; Soylu, M. E.; Barabás, N.; Lofton, D. D.

    2014-12-01

    Global and regional changes in climate have important implications for terrestrial and aquatic ecosystems. Recent studies, for example, have revealed significant warming of inland water bodies throughout the world. To better understand the global patterns, physical mechanisms, and ecological implications of lake warming, an initiative known as the "Global Lake Temperature Collaboration" (GLTC) was started in 2010, with the objective of compiling and analyzing lake temperature data from numerous satellite and in situ records dating back at least 20-30 years. The GLTC project has now assembled data from over 300 lakes, with some in situ records extending back more than 100 years. Here, we present an analysis of the long-term warming trends, interdecadal variability, and a direct comparison between in situ and remotely sensed lake surface temperature for the 3-month summer period July-September (January-March for some lakes). The overall results show consistent, long-term trends of increasing summer-mean lake surface temperature across most but not all sites. Lakes with especially long records show accelerated warming in the most recent two to three decades, with almost half of the lakes warming at rates in excess of 0.5 °C per decade during the period 1985-2009, and a few even exceeding 1.0 °C per decade. Both satellite and in situ data show a similar distribution of warming trends, and a direct comparison at lake sites that have both types of data reveals a close correspondence in mean summer water temperature, interannual variability, and long-term trends. Finally, we examine standardized lake surface temperature anomalies across the full 100-year period (1910-2009), and in conjunction with similar timeseries of air temperature. The results reveal a close correspondence between summer air temperature and lake surface temperature on interannual and interdecadal timescales, but with many lakes warming more rapidly than the ambient air temperature over 25- to 100

  8. Rapid change in the ciprofloxacin resistance pattern among Neisseria gonorrhoeae strains in Nuuk, Greenland

    DEFF Research Database (Denmark)

    Skjerbæk Rolskov, Anne; Bjorn-Mortensen, Karen; Mulvad, Gert

    2015-01-01

    ProbeTec). Monitoring of GC antibiotic susceptibility by culture was introduced in Nuuk in 2012. Until 2014, no cases of ciprofloxacin-resistant GC strains were reported. In this paper, we report the finding of ciprofloxacin-resistant GC and describe the most recent incidence of GC infections...... (9%) were positive, respectively. From January to August, 6 (15%) cultures from Nuuk were ciprofloxacin resistant while in September and October, 26 (59%) were ciprofloxacin resistant (presistance. GC incidence in Nuuk...... was 3,017 per 100,000 inhabitants per year, compared to 2,491 per 100,000 inhabitants per year in the rest of Greenland. CONCLUSION: Within a short period, a rapid and dramatic change in ciprofloxacin susceptibility among GC strains isolated in Nuuk was documented and recommendation for first line...

  9. Tracking Change in rapid and eXtreme Development: A Challenge to SCM-tools?

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2001-01-01

    Software configuration management (SCM) has proved to be an invaluable part of developing and maintaining high quality software. The benefits are not for free however: SCM tool operations often divert your attention from your development task, sometimes you have to endure a long waiting time while...... the tool does its job, change descriptions must be memorised until your next check-in, etc. This kind of overhead and disruption does not fit well with fast-paced development processes like rapid prototyping, explorative programming, and eXtreme Programming that favour creativity, speed, and communication...... more that managerial rigour. In the cost/benefit equation the balance may tip in favour of not using any SCM tool or only using a fraction of its potential. We think SCM has something to offer such projects, and present some proposals that may allow SCM tools to better suit the characteristics of fast...

  10. New insights from coral growth band studies in an era of rapid environmental change

    Science.gov (United States)

    Lough, Janice M.; Cooper, Timothy F.

    2011-10-01

    The rapid formation of calcium carbonate coral skeletons (calcification) fuelled by the coral-algal symbiosis is the backbone of tropical coral reef ecosystems. However, the efficacy of calcification is measurably influenced by the sea's physico-chemical environment, which is changing rapidly. Warming oceans have already led to increased frequency and severity of coral bleaching, and ocean acidification has a demonstrable potential to cause reduced rates of calcification. There is now general agreement that ocean warming and acidification are attributable to human activities increasing greenhouse gas concentrations in the atmosphere, and the large part of the extra carbon dioxide (the main greenhouse gas) that is absorbed by oceans. Certain massive corals provide historical perspectives on calcification through the presence of dateable annual density banding patterns. Each band is a page in an environmental archive that reveals past responses of growth (linear extension, skeletal density and calcification rate) and provides a basis for prediction of future of coral growth. A second major line of research focuses on the measurement of various geochemical tracers incorporated into the growth bands, allowing the reconstruction of past marine climate conditions (i.e. palaeoclimatology). Here, we focus on the structural properties of the annual density bands themselves (viz. density; linear extension), exploring their utility in providing both perspectives on the past and pointers to the future of calcification on coral reefs. We conclude that these types of coral growth records, though relatively neglected in recent years compared to the geochemical studies, remain immensely valuable aids to unravelling the consequences of anthropogenic climate change on coral reefs. Moreover, an understanding of coral growth processes is an essential pre-requisite for proper interpretation of studies of geochemical tracers in corals.

  11. Rapid change in articulatory lip movement induced by preceding auditory feedback during production of bilabial plosives.

    Science.gov (United States)

    Mochida, Takemi; Gomi, Hiroaki; Kashino, Makio

    2010-11-08

    There has been plentiful evidence of kinesthetically induced rapid compensation for unanticipated perturbation in speech articulatory movements. However, the role of auditory information in stabilizing articulation has been little studied except for the control of voice fundamental frequency, voice amplitude and vowel formant frequencies. Although the influence of auditory information on the articulatory control process is evident in unintended speech errors caused by delayed auditory feedback, the direct and immediate effect of auditory alteration on the movements of articulators has not been clarified. This work examined whether temporal changes in the auditory feedback of bilabial plosives immediately affects the subsequent lip movement. We conducted experiments with an auditory feedback alteration system that enabled us to replace or block speech sounds in real time. Participants were asked to produce the syllable /pa/ repeatedly at a constant rate. During the repetition, normal auditory feedback was interrupted, and one of three pre-recorded syllables /pa/, /Φa/, or /pi/, spoken by the same participant, was presented once at a different timing from the anticipated production onset, while no feedback was presented for subsequent repetitions. Comparisons of the labial distance trajectories under altered and normal feedback conditions indicated that the movement quickened during the short period immediately after the alteration onset, when /pa/ was presented 50 ms before the expected timing. Such change was not significant under other feedback conditions we tested. The earlier articulation rapidly induced by the progressive auditory input suggests that a compensatory mechanism helps to maintain a constant speech rate by detecting errors between the internally predicted and actually provided auditory information associated with self movement. The timing- and context-dependent effects of feedback alteration suggest that the sensory error detection works in a

  12. Rapid change in articulatory lip movement induced by preceding auditory feedback during production of bilabial plosives.

    Directory of Open Access Journals (Sweden)

    Takemi Mochida

    Full Text Available BACKGROUND: There has been plentiful evidence of kinesthetically induced rapid compensation for unanticipated perturbation in speech articulatory movements. However, the role of auditory information in stabilizing articulation has been little studied except for the control of voice fundamental frequency, voice amplitude and vowel formant frequencies. Although the influence of auditory information on the articulatory control process is evident in unintended speech errors caused by delayed auditory feedback, the direct and immediate effect of auditory alteration on the movements of articulators has not been clarified. METHODOLOGY/PRINCIPAL FINDINGS: This work examined whether temporal changes in the auditory feedback of bilabial plosives immediately affects the subsequent lip movement. We conducted experiments with an auditory feedback alteration system that enabled us to replace or block speech sounds in real time. Participants were asked to produce the syllable /pa/ repeatedly at a constant rate. During the repetition, normal auditory feedback was interrupted, and one of three pre-recorded syllables /pa/, /Φa/, or /pi/, spoken by the same participant, was presented once at a different timing from the anticipated production onset, while no feedback was presented for subsequent repetitions. Comparisons of the labial distance trajectories under altered and normal feedback conditions indicated that the movement quickened during the short period immediately after the alteration onset, when /pa/ was presented 50 ms before the expected timing. Such change was not significant under other feedback conditions we tested. CONCLUSIONS/SIGNIFICANCE: The earlier articulation rapidly induced by the progressive auditory input suggests that a compensatory mechanism helps to maintain a constant speech rate by detecting errors between the internally predicted and actually provided auditory information associated with self movement. The timing- and context

  13. Interannual Change Detection of Mediterranean Seagrasses Using RapidEye Image Time Series

    Directory of Open Access Journals (Sweden)

    Dimosthenis Traganos

    2018-02-01

    Full Text Available Recent research studies have highlighted the decrease in the coverage of Mediterranean seagrasses due to mainly anthropogenic activities. The lack of data on the distribution of these significant aquatic plants complicates the quantification of their decreasing tendency. While Mediterranean seagrasses are declining, satellite remote sensing technology is growing at an unprecedented pace, resulting in a wealth of spaceborne image time series. Here, we exploit recent advances in high spatial resolution sensors and machine learning to study Mediterranean seagrasses. We process a multispectral RapidEye time series between 2011 and 2016 to detect interannual seagrass dynamics in 888 submerged hectares of the Thermaikos Gulf, NW Aegean Sea, Greece (eastern Mediterranean Sea. We assess the extent change of two Mediterranean seagrass species, the dominant Posidonia oceanica and Cymodocea nodosa, following atmospheric and analytical water column correction, as well as machine learning classification, using Random Forests, of the RapidEye time series. Prior corrections are necessary to untangle the initially weak signal of the submerged seagrass habitats from satellite imagery. The central results of this study show that P. oceanica seagrass area has declined by 4.1%, with a trend of −11.2 ha/yr, while C. nodosa seagrass area has increased by 17.7% with a trend of +18 ha/yr throughout the 5-year study period. Trends of change in spatial distribution of seagrasses in the Thermaikos Gulf site are in line with reported trends in the Mediterranean. Our presented methodology could be a time- and cost-effective method toward the quantitative ecological assessment of seagrass dynamics elsewhere in the future. From small meadows to whole coastlines, knowledge of aquatic plant dynamics could resolve decline or growth trends and accurately highlight key units for future restoration, management, and conservation.

  14. Continuous positive airway pressure (CPAP) changes in bariatric surgery patients undergoing rapid weight loss.

    Science.gov (United States)

    Lankford, D Alan; Proctor, Charles D; Richard, Robert

    2005-03-01

    Obstructive sleep apnea (OSA) is a common condition in morbidly obese patients, with the reported prevalence ranging from 12-78%. There is increasing recognition of the need to diagnose and treat/manage OSA both preoperatively and postoperatively. Nasal CPAP is the preferred treatment of OSA; however, weight loss is associated with a reduction in required pressures. We evaluated the CPAP pressure requirements in a group of patients undergoing rapid weight loss following Roux-en-Y gastric bypass. 15 patients who had been diagnosed with OSA before surgery were retrospectively evaluated. All patients had demonstrated compliance on home CPAP therapy, were minimally 3 months post-surgery and had follow-up reports that their CPAP was less effective. We obtained data on age, sex, weight, BMI, and apnea/hypopnea index (AHI). Optimal CPAP pressure was obtained initially through attended in-laboratory complex polysomnography. Follow-up CPAP pressure was obtained using an auto-titrating PAP device at home. These data were used to evaluate the pressure changes that accompanied weight loss. This group of patients had lost an average of 44.5 +/- 19.4 kg. Four patients had achieved their goal weight. Their starting CPAP pressures averaged 11 +/- 3.0 cm H2O, with a range of 7-18 cm H2O. Follow-up CPAP pressures averaged 9 +/- 2.7 cm H2O, with a range of 4-12 cm H2O, representing an overall reduction of 18%. The subgroup of patients who had achieved goal weight had a pressure reduction of 22% (9 +/- 2.0 to 7 +/- 1.0 cm H2O). CPAP pressure requirements change considerably in bariatric surgery patients undergoing rapid weight loss. Auto-titrating PAP devices have promise for facilitating the management of CPAP therapy during this time. Consideration should also be given to the use of autotitrating PAP units as the treatment of choice in these patients.

  15. Water governance: learning by developing adaptive capacity to incorporate climate variability and change.

    Science.gov (United States)

    Kashyap, A

    2004-01-01

    There is increasing evidence that global climate variability and change is affecting the quality and availability of water supplies. Integrated water resources development, use, and management strategies, represent an effective approach to achieve sustainable development of water resources in a changing environment with competing demands. It is also a key to achieving the Millennium Development Goals. It is critical that integrated water management strategies must incorporate the impacts of climate variability and change to reduce vulnerability of the poor, strengthen sustainable livelihoods and support national sustainable development. UNDP's strategy focuses on developing adaptation in the water governance sector as an entry point within the framework of poverty reduction and national sustainable development. This strategy aims to strengthen the capacity of governments and civil society organizations to have access to early warning systems, ability to assess the impact of climate variability and change on integrated water resources management, and developing adaptation intervention through hands-on learning by undertaking pilot activities.

  16. Reliability and Seasonal Changes of Submaximal Variables to Evaluate Professional Cyclists.

    Science.gov (United States)

    Rodríguez-Marroyo, Jose A; Pernía, Raúl; Villa, José G; Foster, Carl

    2017-11-01

    The aim of this study was to determine the reliability and validity of several submaximal variables that can be easily obtained by monitoring cyclists' performances. Eighteen professional cyclists participated in this study. In a first part (n = 15) the test-retest reliability of heart rate (HR) and rating of perceived exertion (RPE) during a progressive maximal test was measured. Derived submaximal variables based on HR, RPE, and power output (PO) responses were analyzed. In a second part (n = 7) the pattern of the submaximal variables according to cyclists' training status was analyzed. Cyclists were assessed 3 times during the season: at the beginning of the season, before the Vuelta a España, and the day after this Grand Tour. Part 1: No significant differences in maximal and submaximal variables between test-retest were found. Excellent ICCs (0.81-0.98) were obtained in all variables. Part 2: The HR and RPE showed a rightward shift from early to peak season. In addition, RPE showed a left shift after the Vuelta a España. Submaximal variables based on RPE had the best relationship with both performance and changes in performance. The present study showed the reliability of different maximal and submaximal variables used to assess cyclists' performances. Submaximal variables based on RPE seem to be the best to monitor changes in training status over a season.

  17. An invasive species induces rapid adaptive change in a native predator: cane toads and black snakes in Australia.

    Science.gov (United States)

    Phillips, Ben L; Shine, Richard

    2006-06-22

    Rapid environmental change due to human activities has increased rates of extinction, but some species may be able to adapt rapidly enough to deal with such changes. Our studies of feeding behaviour and physiological resistance to toxins reveal surprisingly rapid adaptive responses in Australian black snakes (Pseudechis porphyriacus) following the invasion of a lethally toxic prey item, the cane toad (Bufo marinus). Snakes from toad-exposed localities showed increased resistance to toad toxin and a decreased preference for toads as prey. Separate laboratory experiments suggest that these changes are not attributable to learning (we were unable to teach naive snakes to avoid toxic prey) or to acquired resistance (repeated sub-lethal doses did not enhance resistance). These results strongly suggest that black snake behaviour and physiology have evolved in response to the presence of toads, and have done so rapidly. Toads were brought to Australia in 1935, so these evolved responses have occurred in fewer than 23 snake generations.

  18. How changes in extracellular matrix mechanics and gene expression variability might combine to drive cancer progression.

    Directory of Open Access Journals (Sweden)

    Justin Werfel

    Full Text Available Changes in extracellular matrix (ECM structure or mechanics can actively drive cancer progression; however, the underlying mechanism remains unknown. Here we explore whether this process could be mediated by changes in cell shape that lead to increases in genetic noise, given that both factors have been independently shown to alter gene expression and induce cell fate switching. We do this using a computer simulation model that explores the impact of physical changes in the tissue microenvironment under conditions in which physical deformation of cells increases gene expression variability among genetically identical cells. The model reveals that cancerous tissue growth can be driven by physical changes in the microenvironment: when increases in cell shape variability due to growth-dependent increases in cell packing density enhance gene expression variation, heterogeneous autonomous growth and further structural disorganization can result, thereby driving cancer progression via positive feedback. The model parameters that led to this prediction are consistent with experimental measurements of mammary tissues that spontaneously undergo cancer progression in transgenic C3(1-SV40Tag female mice, which exhibit enhanced stiffness of mammary ducts, as well as progressive increases in variability of cell-cell relations and associated cell shape changes. These results demonstrate the potential for physical changes in the tissue microenvironment (e.g., altered ECM mechanics to induce a cancerous phenotype or accelerate cancer progression in a clonal population through local changes in cell geometry and increased phenotypic variability, even in the absence of gene mutation.

  19. Climate Change and Variability: Farmers’ Perception, Experience and Adaptation Strategies in Makueni County, Kenya

    OpenAIRE

    Kitinya, Kirina T.; Onwonga, Richard N.; Cecilia Onyango; Mbuvi, Joseph P.; Geoffrey Kironchi

    2012-01-01

    A better understanding of climate change and variability (CCV) from the farmer’s perspective is a key to prioritizing measures to address and prepare for its consequences. A survey involving 150 farmers was thus conducted in Makueni County, Kenya to document farmers’; perception, experience and adaptation strategies to CCV. About 86% of farmers perceived CCV as a major challenge with 53% indicating that significant changes in climate would manifest in 10-20 years. Significant changes in rainf...

  20. Capturing subregional variability in regional-scale climate change vulnerability assessments of natural resources.

    Science.gov (United States)

    Buotte, Polly C; Peterson, David L; McKelvey, Kevin S; Hicke, Jeffrey A

    2016-03-15

    Natural resource vulnerability to climate change can depend on the climatology and ecological conditions at a particular site. Here we present a conceptual framework for incorporating spatial variability in natural resource vulnerability to climate change in a regional-scale assessment. The framework was implemented in the first regional-scale vulnerability assessment conducted by the US Forest Service. During this assessment, five subregional workshops were held to capture variability in vulnerability and to develop adaptation tactics. At each workshop, participants answered a questionnaire to: 1) identify species, resources, or other information missing from the regional assessment, and 2) describe subregional vulnerability to climate change. Workshop participants divided into six resource groups; here we focus on wildlife resources. Participants identified information missing from the regional assessment and multiple instances of subregional variability in climate change vulnerability. We provide recommendations for improving the process of capturing subregional variability in a regional vulnerability assessment. We propose a revised conceptual framework structured around pathways of climate influence, each with separate rankings for exposure, sensitivity, and adaptive capacity. These revisions allow for a quantitative ranking of species, pathways, exposure, sensitivity, and adaptive capacity across subregions. Rankings can be used to direct the development and implementation of future regional research and monitoring programs. The revised conceptual framework is equally applicable as a stand-alone model for assessing climate change vulnerability and as a nested model within a regional assessment for capturing subregional variability in vulnerability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. A decade of rapid change: Biocultural influences on child growth in highland Peru.

    Science.gov (United States)

    Oths, Kathryn S; Smith, Hannah N; Stein, Max J; Lazo Landivar, Rodrigo J

    2017-10-30

    In the past decade many areas of Peru have been undergoing extreme environmental, economic, and cultural change. In the highland hamlet of Chugurpampa, La Libertad, climate change has ruined harvests and led to frequent periods of migration to the coast in search of livelihood. This biocultural research examines how the changes could be affecting the growth of children who maintain residence in the highlands. Clinical records from the early 2000s were compared to those from the early 2010s. Charts were randomly selected to record anthropometric data, netting a sample of 75 children ages 0-60 months of age. Analysis of covariance was run to compare mean stature, weight, and BMI between cohorts. Percentage of children who fall below the -2 threshold for z-scores for height and weight were compared by age and cohort. A significant secular trend in growth was found, with children born more recently larger than those born a decade before. The effect is most notable in the first year of life, with the growth advantage attenuated by the age of 3 for height and age 4 for weight. While children were unlikely to be stunted from 0 to 3 years of age, 44% of the later cohort were stunted and 11% were underweight from 4 to 5 years of age. Three possible explanations for the rapid shift are entertained: more time spent on the coast during gestation and early childhood, which may attenuate the effect of hypoxia on child growth; dietary change; and increased use of biomedicine. © 2017 Wiley Periodicals, Inc.

  2. Holocene fluvial geochronologies, global databases and hydrological proxies: rethinking people-river interactions and rapid climate change impacts (Invited)

    Science.gov (United States)

    Macklin, M. G.

    2009-12-01

    The assumption of the constancy of climate over time periods of around a century, which was the basis of much engineering and hydrological forward planning until recently, is now widely felt to be unsatisfactory. This re-evaluation has been prompted by a number of important empirical, interdisciplinary and technological advances in fluvial science research over the last decade that is increasingly being carried out in a global framework. Some of the more important developments have included: 1. wider application of high precision sediment-based dating techniques (e.g. OSL) to a greater range of fluvial environments; 2. worldwide database compilation and statistical analysis of 14C dated Holocene fluvial units, enabling the identification of climatic and anthropogenic environmental signals in fluvial sedimentary sequences; and 3. new earth surface observation (e.g. LIDAR) and sediment core analysis (e.g. ITRAX core scanner) techniques that are providing event-scale reconstructions of fluvial environments. Drawing on recent geoarchaeological research in the lower Nile valley, 14C database analysis and comparison of Holocene fluvial records in Europe and New Zealand, and a new 3700-year continuous flood record from the UK reconstructed from fine-grained floodplain sediments, the impact of rapid climate change on riverine societies resulting from monsoon, thermohaline circulation, ENSO and NAO variability is critically reviewed. These studies show that establishing causal relationships between river dynamics and cultural/demographic change is not a straightforward task and identifying possible natural environmental triggers of societal change is especially problematic. A solution may be to stress the inseparable nature of environmental and cultural influences, and view the physical environment as a delimiter of possible action rather than as a prescriptive agency.

  3. Impacts of rainfall variability and expected rainfall changes on cost-effective adaptation of water systems to climate change.

    Science.gov (United States)

    van der Pol, T D; van Ierland, E C; Gabbert, S; Weikard, H-P; Hendrix, E M T

    2015-05-01

    Stormwater drainage and other water systems are vulnerable to changes in rainfall and runoff and need to be adapted to climate change. This paper studies impacts of rainfall variability and changing return periods of rainfall extremes on cost-effective adaptation of water systems to climate change given a predefined system performance target, for example a flood risk standard. Rainfall variability causes system performance estimates to be volatile. These estimates may be used to recurrently evaluate system performance. This paper presents a model for this setting, and develops a solution method to identify cost-effective investments in stormwater drainage adaptations. Runoff and water levels are simulated with rainfall from stationary rainfall distributions, and time series of annual rainfall maxima are simulated for a climate scenario. Cost-effective investment strategies are determined by dynamic programming. The method is applied to study the choice of volume for a storage basin in a Dutch polder. We find that 'white noise', i.e. trend-free variability of rainfall, might cause earlier re-investment than expected under projected changes in rainfall. The risk of early re-investment may be reduced by increasing initial investment. This can be cost-effective if the investment involves fixed costs. Increasing initial investments, therefore, not only increases water system robustness to structural changes in rainfall, but could also offer insurance against additional costs that would occur if system performance is underestimated and re-investment becomes inevitable. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Correlative Changes in Life-History Variables in Response to Environmental Change in a Model Organism

    NARCIS (Netherlands)

    Smallegange, I.M.; Deere, J.A.; Coulson, T.

    2014-01-01

    Global change alters the environment, including increases in the frequency of (un)favorable events and shifts in environmental noise color. However, how these changes impact the dynamics of populations, and whether these can be predicted accurately has been largely unexamined. Here we combine

  5. Late Quaternary Biosiliceous Laminated Marine Sediments From Antarctica: Seasonality During a Period of Rapid Climate Change

    Science.gov (United States)

    Pike, J.; Stickley, C. E.; Maddison, E. J.; Leventer, A.; Brachfeld, S.; Domack, E. W.; Dunbar, R. B.; Manley, P. L.; McClennen, C.

    2004-12-01

    The Antarctic ice sheet plays a key role in global oceanic and atmosphere systems. One of the most dynamic regions of the continent is the Antarctic Peninsula (AP) where ecological and cryospheric systems respond rapidly to climate change, such as the last deglaciation ( ˜12-13 kyr BP). Here, deglacial laminated diatom-rich marine sediments are well known, e.g., Palmer Deep (64° S 64° W; ODP Hole 1098A) comprising a distinctive 3 m thick sequence of deglacial `couplet' laminations. The East Antarctic margin (EAM), however, has received less attention than the West Antarctic margin (WAM) in palaeoceanographic studies yet its role in deep ocean circulation and, therefore, the global ocean system is significant. Recent sediment cores recovered from EAM sites during NSF Polar Programs-funded cruise NBP0101 in February and March 2001 (e.g. Mertz Drift \\{66° S 143° E\\}, Svenner Channel \\{69° S 77° E\\} in Prydz Bay, Nielsen Basin \\{67° S 66° E\\} and Iceberg Alley \\{67° S 63° E\\}), reveal that a similar sedimentary facies was deposited along the EAM, in similar geomorphological settings to Palmer Deep, during the same timeframe. These rich sediment archives reveal clues about circum-Antarctic palaeoceanographic change during the last deglaciation, a time of both high silica flux and rapid climate change. Microfabrics and diatom assemblages from scanning electron microscope backscattered and secondary electron imagery analysis of coeval deglacial varves from Palmer Deep (WAM), Mertz-Ninnis Trough and Iceberg Alley (EAM) are presented and compared. The varves from these localities are characterised by laminae to thin beds of orange-brown diatom ooze up to ˜8cm thick alternating with blue-grey diatom-bearing terrigenous sediments up to ˜4cm thick. The orange-brown oozes are dominated by resting spores and vegetative valves of Hyalochaete Chaetoceros spp., resulting from spring sedimentation associated with stratified surface waters promoting exceptionally

  6. The Impact of Rapid Climate Change on Prehistoric Societies during the Holocene in the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    Bernhard Weninger

    2009-12-01

    Full Text Available In this paper we explore the impact of Rapid Climate Change (RCC on prehistoric communities in the Eastern Mediterranean during the Early and Middle Holocene. Our focus is on the social implications of the four major climate cold anomalies that have recently been identified as key time-windows for global RCC (Mayewski et al. 2004. These cooling anomalies are well-dated, with Greenland ice-core resolution, due to synchronicity between warm/cold foraminifera ratios in Mediterranean core LC21 as a proxy for surface water temperature, and Greenland GISP2 non sea-salt (nss [K+] ions as a proxy for the intensification of the Siberian High and for polar air outbreaks in the northeast Mediterranean (Rohling et al. 2002. Building on these synchronisms, the GISP2 agemodel supplies the following precise time-intervals for archaeological RCC research: (i 8.6–8.0 ka, (ii 6.0–5.2 ka, (iii 4.2–4.0 ka and (iv 3.1–2.9 ka calBP. For each of these RCC time intervals, based on detailed 14C-based chronological studies, we investigate contemporaneous cultural developments. From our studies it follows that RCC-related climatic deterioration is a major factor underlying social change, although always at work within a wide spectrum of social, cultural, economic and religious factors.

  7. Application of stages of change model to adolescents' physical activity in relation to psychological variables.

    Science.gov (United States)

    Abarca-Sos, A; Bois, J E; Generelo, E; Julián, J A; Zaragoza, J

    2015-11-01

    This study investigated the stages of change in physical activity in relation to psychological variables: self-efficacy, physical self-concept and barriers to physical activity, as well as gender. Furthermore, cluster profiles were created based on psychological variables to be compared with stages of change groups. Data were obtained from a representative sample of adolescents (N.=1618, 14.46±1.28 years) from Aragon region (Spain). The different strata were selected according to the geographical region, environment, type of school, age and gender Males (75.5%) and very active adolescents (96.9% participant boys and 93.5% participants girls) were more prevalent in the action and maintenance groups. We found significant differences in psychosocial variables by stages of change and gender, showing higher scores in active groups for physical self-concept (effects of gender and stages of change: F(1, 1618)=313.82 Pstages of change groups (χ²(1)=162,76, Pchange behaviour, not only stage of change model variables. Furthermore, the study can be relevant to designing more effective health promotion programmes in the adolescent population.

  8. Rapid change in drift of the Australian plate records collision with Ontong Java plateau.

    Science.gov (United States)

    Knesel, Kurt M; Cohen, Benjamin E; Vasconcelos, Paulo M; Thiede, David S

    2008-08-07

    The subduction of oceanic plateaux, which contain extraordinarily thick basaltic crust and are the marine counterparts of continental flood-basalt provinces, is an important factor in many current models of plate motion and provides a potential mechanism for triggering plate reorganization. To evaluate such models, it is essential to decipher the history of the collision between the largest and thickest of the world's oceanic plateaux, the Ontong Java plateau, and the Australian plate, but this has been hindered by poor constraints for the arrival of the plateau at the Melanesian trench. Here we present (40)Ar-(39)Ar geochronological data on hotspot volcanoes in eastern Australian that reveal a strong link between collision of the Greenland-sized Ontong Java plateau with the Melanesian arc and motion of the Australian plate. The new ages define a short-lived period of reduced northward plate motion between 26 and 23 Myr ago, coincident with an eastward offset in the contemporaneous tracks of seamount chains in the Tasman Sea east of Australia. These features record a brief westward deflection of the Australian plate as the plateau entered and choked the Melanesian trench 26 Myr ago. From 23 Myr ago, Australia returned to a rapid northerly trajectory at roughly the same time that southwest-directed subduction began along the Trobriand trough. The timing and brevity of this collisional event correlate well with offsets in hotspot seamount tracks on the Pacific plate, including the archetypal Hawaiian chain, and thus provide strong evidence that immense oceanic plateaux, like the Ontong Java, can contribute to initiating rapid change in plate boundaries and motions on a global scale.

  9. Subchondral Bone Plate Changes More Rapidly than Trabecular Bone in Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Zaitunnatakhin Zamli

    2016-09-01

    Full Text Available Osteoarthritis (OA is the most common joint disorder, characterised by focal loss of cartilage and increased subchondral bone remodelling at early OA stages of the disease. We have investigated the temporal and the spatial relationship between bone remodelling in subchondral bone plate (Sbp and trabecular bone (Tb in Dunkin Hartley (DH, develop OA early and the Bristol Strain 2 (BS2, control which develop OA late guinea pigs. Right tibias were dissected from six male animals of each strain, at 10, 16, 24 and 30 weeks of age. Micro-computed tomography was used to quantify the growth plate thickness (GpTh, subchondral bone plate thickness (SbpTh and trabecular bone thickness (TbTh, and bone mineral density (BMD in both Sbp and Tb. The rate of change was calculated for 10–16 weeks, 16–24 weeks and 24–30 weeks. The rate of changes in Sbp and Tb thickness at the earliest time interval (10–16 weeks were significantly greater in DH guinea pigs than in the growth-matched control strain (BS2. The magnitude of these differences was greater in the medial side than the lateral side (DH: 22.7 and 14.75 µm/week, BS2: 5.63 and 6.67 µm/week, respectively. Similarly, changes in the BMD at the earliest time interval was greater in the DH strain than the BS2, again more pronounced in the disease prone medial compartment (DH: 0.0698 and 0.0372 g/cm3/week, BS2: 0.00457 and 0.00772 g/cm3/week, respectively. These changes observed preceded microscopic and cellular signs of disease as previously reported. The rapid early changes in SbpTh, TbTh, Sbp BMD and Tb BMD in the disease prone DH guinea pigs compared with the BS2 control strain suggest a link to early OA pathology. This is corroborated by the greater relative changes in subchondral bone in the medial compared with the lateral compartment.

  10. Changes in climate variability with reference to land quality and agriculture in Scotland.

    Science.gov (United States)

    Brown, Iain; Castellazzi, Marie

    2015-06-01

    Classification and mapping of land capability represents an established format for summarising spatial information on land quality and land-use potential. By convention, this information incorporates bioclimatic constraints through the use of a long-term average. However, climate change means that land capability classification should also have a dynamic temporal component. Using an analysis based upon Land Capability for Agriculture in Scotland, it is shown that this dynamism not only involves the long-term average but also shorter term spatiotemporal patterns, particularly through changes in interannual variability. Interannual and interdecadal variations occur both in the likelihood of land being in prime condition (top three capability class divisions) and in class volatility from year to year. These changing patterns are most apparent in relation to the west-east climatic gradient which is mainly a function of precipitation regime and soil moisture. Analysis is also extended into the future using climate results for the 2050s from a weather generator which show a complex interaction between climate interannual variability and different soil types for land quality. In some locations, variability of land capability is more likely to decrease because the variable climatic constraints are relaxed and the dominant constraint becomes intrinsic soil properties. Elsewhere, climatic constraints will continue to be influential. Changing climate variability has important implications for land-use planning and agricultural management because it modifies local risk profiles in combination with the current trend towards agricultural intensification and specialisation.

  11. Rapid small lot manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Harrigan, R.W.

    1998-05-09

    The direct connection of information, captured in forms such as CAD databases, to the factory floor is enabling a revolution in manufacturing. Rapid response to very dynamic market conditions is becoming the norm rather than the exception. In order to provide economical rapid fabrication of small numbers of variable products, one must design with manufacturing constraints in mind. In addition, flexible manufacturing systems must be programmed automatically to reduce the time for product change over in the factory and eliminate human errors. Sensor based machine control is needed to adapt idealized, model based machine programs to uncontrolled variables such as the condition of raw materials and fabrication tolerances.

  12. Rapid Environmental Change Drives Increased Land Use by an Arctic Marine Predator.

    Directory of Open Access Journals (Sweden)

    Todd C Atwood

    Full Text Available In the Arctic Ocean's southern Beaufort Sea (SB, the length of the sea ice melt season (i.e., period between the onset of sea ice break-up in summer and freeze-up in fall has increased substantially since the late 1990s. Historically, polar bears (Ursus maritimus of the SB have mostly remained on the sea ice year-round (except for those that came ashore to den, but recent changes in the extent and phenology of sea ice habitat have coincided with evidence that use of terrestrial habitat is increasing. We characterized the spatial behavior of polar bears spending summer and fall on land along Alaska's north coast to better understand the nexus between rapid environmental change and increased use of terrestrial habitat. We found that the percentage of radiocollared adult females from the SB subpopulation coming ashore has tripled over 15 years. Moreover, we detected trends of earlier arrival on shore, increased length of stay, and later departure back to sea ice, all of which were related to declines in the availability of sea ice habitat over the continental shelf and changes to sea ice phenology. Since the late 1990s, the mean duration of the open-water season in the SB increased by 36 days, and the mean length of stay on shore increased by 31 days. While on shore, the distribution of polar bears was influenced by the availability of scavenge subsidies in the form of subsistence-harvested bowhead whale (Balaena mysticetus remains aggregated at sites along the coast. The declining spatio-temporal availability of sea ice habitat and increased availability of human-provisioned resources are likely to result in increased use of land. Increased residency on land is cause for concern given that, while there, bears may be exposed to a greater array of risk factors including those associated with increased human activities.

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

    Science.gov (United States)

    Jimenez, Ana G; Williams, Joseph B

    2014-12-01

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

  14. Pacific Decadal Variability and Central Pacific Warming El Niño in a Changing Climate

    Energy Technology Data Exchange (ETDEWEB)

    Di Lorenzo, Emanuele [Georgia Inst. of Technology, Atlanta, GA (United States)

    2015-02-27

    This research aimed at understanding the dynamics controlling decadal variability in the Pacific Ocean and its interactions with global-scale climate change. The first goal was to assess how the dynamics and statistics of the El Niño Southern Oscillation and the modes of Pacific decadal variability are represented in global climate models used in the IPCC. The second goal was to quantify how decadal dynamics are projected to change under continued greenhouse forcing, and determine their significance in the context of paleo-proxy reconstruction of long-term climate.

  15. Evidence for rapid climate change in the Mesozoic-Palaeogene greenhouse world.

    Science.gov (United States)

    Jenkyns, Hugh C

    2003-09-15

    The best-documented example of rapid climate change that characterized the so-called 'greenhouse world' took place at the time of the Palaeocene-Eocene boundary: introduction of isotopically light carbon into the ocean-atmosphere system, accompanied by global warming of 5-8 degrees C across a range of latitudes, took place over a few thousand years. Dissociation, release and oxidation of gas hydrates from continental-margin sites and the consequent rapid global warming from the input of greenhouses gases are generally credited with causing the abrupt negative excursions in carbon- and oxygen-isotope ratios. The isotopic anomalies, as recorded in foraminifera, propagated downwards from the shallowest levels of the ocean, implying that considerable quantities of methane survived upward transit through the water column to oxidize in the atmosphere. In the Mesozoic Era, a number of similar events have been recognized, of which those at the Triassic-Jurassic boundary, in the early Toarcian (Jurassic) and in the early Aptian (Cretaceous) currently carry the best documentation for dramatic rises in temperature. In these three examples, and in other less well-documented cases, the lack of a definitive time-scale for the intervals in question hinders calculation of the rate of environmental change. However, comparison with the Palaeocene-Eocene thermal maximum (PETM) suggests that these older examples could have been similarly rapid. In both the early Toarcian and early Aptian cases, the negative carbon-isotope excursion precedes global excess carbon burial across a range of marine environments, a phenomenon that defines these intervals as oceanic anoxic events (OAEs). Osmium-isotope ratios ((187)Os/(188)Os) for both the early Toarcian OAE and the PETM show an excursion to more radiogenic values, demonstrating an increase in weathering and erosion of continental crust consonant with elevated temperatures. The more highly buffered strontium-isotope system ((87)Sr/(86)Sr

  16. Changes in field workability and drought risk from projected climate change drive spatially variable risks in Illinois cropping systems.

    Directory of Open Access Journals (Sweden)

    Bradley J Tomasek

    Full Text Available As weather patterns become more volatile and extreme, risks introduced by weather variability will become more critical to agricultural production. The availability of days suitable for field work is driven by soil temperature and moisture, both of which may be altered by climate change. We projected changes in Illinois season length, spring field workability, and summer drought risk under three different emissions scenarios (B1, A1B, and A2 down to the crop district scale. Across all scenarios, thermal time units increased in parallel with a longer frost-free season. An increase in late March and Early April field workability was consistent across scenarios, but a decline in overall April through May workable days was observed for many cases. In addition, summer drought metrics were projected to increase for most scenarios. These results highlight how the spatial and temporal variability in climate change may present unique challenges to mitigation and adaptation efforts.

  17. Changes in field workability and drought risk from projected climate change drive spatially variable risks in Illinois cropping systems.

    Science.gov (United States)

    Tomasek, Bradley J; Williams, Martin M; Davis, Adam S

    2017-01-01

    As weather patterns become more volatile and extreme, risks introduced by weather variability will become more critical to agricultural production. The availability of days suitable for field work is driven by soil temperature and moisture, both of which may be altered by climate change. We projected changes in Illinois season length, spring field workability, and summer drought risk under three different emissions scenarios (B1, A1B, and A2) down to the crop district scale. Across all scenarios, thermal time units increased in parallel with a longer frost-free season. An increase in late March and Early April field workability was consistent across scenarios, but a decline in overall April through May workable days was observed for many cases. In addition, summer drought metrics were projected to increase for most scenarios. These results highlight how the spatial and temporal variability in climate change may present unique challenges to mitigation and adaptation efforts.

  18. Three dimensional evaluation of alveolar bone changes in response to different rapid palatal expansion activation rates

    Directory of Open Access Journals (Sweden)

    Brian LaBlonde

    Full Text Available ABSTRACT Introduction: The aim of this multi-center retrospective study was to quantify the changes in alveolar bone height and thickness after using two different rapid palatal expansion (RPE activation protocols, and to determine whether a more rapid rate of expansion is likely to cause more adverse effects, such as alveolar tipping, dental tipping, fenestration and dehiscence of anchorage teeth. Methods: The sample consisted of pre- and post-expansion records from 40 subjects (age 8-15 years who underwent RPE using a 4-banded Hyrax appliance as part of their orthodontic treatment to correct posterior buccal crossbites. Subjects were divided into two groups according to their RPE activation rates (0.5 mm/day and 0.8 mm/day; n = 20 each group. Three-dimensional images for all included subjects were evaluated using Dolphin Imaging Software 11.7 Premium. Maxillary base width, buccal and palatal cortical bone thickness, alveolar bone height, and root angulation and length were measured. Significance of the changes in the measurements was evaluated using Wilcoxon signed-rank test and comparisons between groups were done using ANOVA. Significance was defined at p ≤ 0.05. Results: RPE activation rates of 0.5 mm per day (Group 1 and 0.8 mm per day (Group 2 caused significant increase in arch width following treatment; however, Group 2 showed greater increases compared to Group 1 (p < 0.01. Buccal alveolar height and width decreased significantly in both groups. Both treatment protocols resulted in significant increases in buccal-lingual angulation of teeth; however, Group 2 showed greater increases compared to Group 1 (p < 0.01. Conclusion: Both activation rates are associated with significant increase in intra-arch widths. However, 0.8 mm/day resulted in greater increases. The 0.8 mm/day activation rate also resulted in more increased dental tipping and decreased buccal alveolar bone thickness over 0.5 mm/day.

  19. Dental arch changes associated with rapid maxillary expansion: A retrospective model analysis study

    Directory of Open Access Journals (Sweden)

    Ivor M D′Souza

    2015-01-01

    Full Text Available Introduction: Transverse deficiency of the maxilla is a common clinical problem in orthodontics and dentofacial orthopedics. Transverse maxillary deficiency, isolated or associated with other dentofacial deformities, results in esthetic and functional impairment giving rise to several clinical manifestations such as asymmetrical facial growth, positional and functional mandibular deviations, altered dentofacial esthetics, adverse periodontal responses, unstable dental tipping, and other functional problems. Orthopedic maxillary expansion is the preferred treatment approach to increase the maxillary transverse dimension in young patients by splitting of the mid palatal suture. This orthopedic procedure has lately been subject of renewed interest in orthodontic treatment mechanics because of its potential for increasing arch perimeter to alleviate crowding in the maxillary arch without adversely affecting facial profile. Hence, the present investigation was conducted to establish a correlation between transverse expansion and changes in the arch perimeter, arch width and arch length. Methods: For this purpose, 10 subjects (five males, five females were selected who had been treated by rapid maxillary expansion (RME using hyrax rapid palatal expander followed by fixed mechanotherapy (PEA. Pretreatment (T1, postexpansion (T2, and posttreatment (T3 dental models were compared for dental changes brought about by RME treatment and its stability at the end of fixed mechanotherapy. After model measurements were made, the changes between T1-T2, T2-T3 and T1-T3 were determined for each patient. The mean difference between T1-T2, T2-T3 and T1-T3 were compared to assess the effects of RME on dental arch measurements. Results are expressed as mean ± standard deviation and are compared by repeated measures analysis of variance followed by a post-hoc test. Arch perimeter changes are correlated with changes in arch widths at the canine, premolar and molar

  20. Atmospheric radiative feedbacks associated with transient climate change and climate variability

    Energy Technology Data Exchange (ETDEWEB)

    Colman, Robert A.; Power, Scott B. [Bureau of Meteorology, Centre for Australian Weather and Climate Research, GPO Box 1289, Melbourne, VIC (Australia)

    2010-06-15

    This study examines in detail the 'atmospheric' radiative feedbacks operating in a coupled General Circulation Model (GCM). These feedbacks (defined as the change in top of atmosphere radiation per degree of global surface temperature change) are due to responses in water vapour, lapse rate, clouds and surface albedo. Two types of radiative feedback in particular are considered: those arising from century scale 'transient' warming (from a 1% per annum compounded CO{sub 2} increase), and those operating under the model's own unforced 'natural' variability. The time evolution of the transient (or 'secular') feedbacks is first examined. It is found that both the global strength and the latitudinal distributions of these feedbacks are established within the first two or three decades of warming, and thereafter change relatively little out to 100 years. They also closely approximate those found under equilibrium warming from a 'mixed layer' ocean version of the same model forced by a doubling of CO{sub 2}. These secular feedbacks are then compared with those operating under unforced (interannual) variability. For water vapour, the interannual feedback is only around two-thirds the strength of the secular feedback. The pattern reveals widespread regions of negative feedback in the interannual case, in turn resulting from patterns of circulation change and regions of decreasing as well as increasing surface temperature. Considering the vertical structure of the two, it is found that although positive net mid to upper tropospheric contributions dominate both, they are weaker (and occur lower) under interannual variability than under secular change and are more narrowly confined to the tropics. Lapse rate feedback from variability shows weak negative feedback over low latitudes combined with strong positive feedback in mid-to-high latitudes resulting in no net global feedback - in contrast to the dominant negative low

  1. Pleistocene climate change promoted rapid diversification of aquatic invertebrates in Southeast Australia

    Directory of Open Access Journals (Sweden)

    Hawlitschek Oliver

    2012-08-01

    Full Text Available Abstract Background The Pleistocene Ice Ages were the most recent geohistorical event of major global impact, but their consequences for most parts of the Southern hemisphere remain poorly known. We investigate a radiation of ten species of Sternopriscus, the most species-rich genus of epigean Australian diving beetles. These species are distinct based on genital morphology but cannot be distinguished readily by mtDNA and nDNA because of genotype sharing caused by incomplete lineage sorting. Their genetic similarity suggests a Pleistocene origin. Results We use a dataset of 3858 bp of mitochondrial and nuclear DNA to reconstruct a phylogeny of Sternopriscus using gene and species trees. Diversification analyses support the finding of a recent rapid speciation event with estimated speciation rates of up to 2.40 species per MY, which is considerably higher than the proposed average rate of 0.16 species per MY for insects. Additionally, we use ecological niche modeling and analyze data on habitat preferences to test for niche divergence between species of the recent Sternopriscus radiation. These analyses show that the species can be characterized by a set of ecological variables referring to habitat, climate and altitude. Conclusions Our results suggest that the repeated isolation of populations in glacial refugia might have led to divergent ecological adaptations and the fixation of morphological traits supporting reproductive isolation and therefore may have promoted speciation. The recent Sternopriscus radiation fulfills many characteristics of a species flock and would be the first described example of an aquatic insect species flock. We argue that the species of this group may represent a stage in speciation past the species flock condition because of their mostly broad and often non-overlapping ranges and preferences for different habitat types.

  2. Pleistocene climate change promoted rapid diversification of aquatic invertebrates in Southeast Australia.

    Science.gov (United States)

    Hawlitschek, Oliver; Hendrich, Lars; Espeland, Marianne; Toussaint, Emmanuel F A; Genner, Martin J; Balke, Michael

    2012-08-09

    The Pleistocene Ice Ages were the most recent geohistorical event of major global impact, but their consequences for most parts of the Southern hemisphere remain poorly known. We investigate a radiation of ten species of Sternopriscus, the most species-rich genus of epigean Australian diving beetles. These species are distinct based on genital morphology but cannot be distinguished readily by mtDNA and nDNA because of genotype sharing caused by incomplete lineage sorting. Their genetic similarity suggests a Pleistocene origin. We use a dataset of 3858 bp of mitochondrial and nuclear DNA to reconstruct a phylogeny of Sternopriscus using gene and species trees. Diversification analyses support the finding of a recent rapid speciation event with estimated speciation rates of up to 2.40 species per MY, which is considerably higher than the proposed average rate of 0.16 species per MY for insects. Additionally, we use ecological niche modeling and analyze data on habitat preferences to test for niche divergence between species of the recent Sternopriscus radiation. These analyses show that the species can be characterized by a set of ecological variables referring to habitat, climate and altitude. Our results suggest that the repeated isolation of populations in glacial refugia might have led to divergent ecological adaptations and the fixation of morphological traits supporting reproductive isolation and therefore may have promoted speciation. The recent Sternopriscus radiation fulfills many characteristics of a species flock and would be the first described example of an aquatic insect species flock. We argue that the species of this group may represent a stage in speciation past the species flock condition because of their mostly broad and often non-overlapping ranges and preferences for different habitat types.

  3. Understanding the rapid summer warming and changes in temperature extremes since the mid-1990s over Western Europe

    OpenAIRE

    Dong, Buwen; Sutton, Rowan T.; Shaffrey, Len; Buwen Dong

    2017-01-01

    Analysis of observations indicates that there was a rapid increase in summer (June-August, JJA) mean surface air temperature (SAT) since the mid-1990s over Western Europe. Accompanying this rapid warming are significant increases in summer mean daily maximum temperature, daily minimum temperature, annual hottest day temperature and warmest night temperature, and an increase in frequency of summer days and tropical nights, while the change in the diurnal temperature range (DTR) is small. This ...

  4. Spatial-temporal gait variability poststroke: variations in measurement and implications for measuring change.

    Science.gov (United States)

    Chisholm, Amanda E; Makepeace, Shelley; Inness, Elizabeth L; Perry, Stephen D; McIlroy, William E; Mansfield, Avril

    2014-07-01

    To determine the responsiveness to change of spatial-temporal gait parameters among stroke survivors for 3 different variability measures: SD, coefficient of variation (CV), and median absolute deviation (MAD). Retrospective chart review. Clinical laboratory in a Canadian hospital. Stroke survivors (N=74) receiving inpatient rehabilitation. Not applicable. Spatial-temporal gait variability was calculated for step length, step width, stance time, swing time, and double support time. Responsiveness to change was determined by comparing (1) trials without versus trials with a concurrent cognitive task and (2) admission to discharge from rehabilitation. Variability estimators (SD, CV, and MAD) increased with the addition of a cognitive task and decreased from admission to discharge of rehabilitation. However, these changes were not statistically significant when change in gait velocity was included as a covariate. The effect size values were similar for all variability estimators with a trend toward a greater SD response to temporal parameters. The CV displayed a larger response to change for step length than did the SD and MAD. Although gait variability decreased between admission and discharge, the effect size was larger for the condition without the cognitive task than for the condition with the cognitive task. Our results show that gait variability estimators demonstrate a similar responsiveness to a concurrent cognitive task and improved walking ability with recovery from stroke. Future work may focus on evaluating the clinical utility of these measures in relation to informing therapy and response to gait-specific training protocols. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  5. Variable effects of dispersal on productivity of bacterial communities due to changes in functional trait composition

    DEFF Research Database (Denmark)

    Severin, Ina; Östman, Örjan; Lindström, Eva S.

    2013-01-01

    dispersal - productivity relationships. Instead, changes in trait composition with dispersal, especially the communities' ability to use p-coumaric acid, an aromatic compound, could explain the observed dispersal - productivity relationships. Changes in this trait caused by dispersal seemed especially......Previous studies have shown variable relationships between dispersal rate and ecosystem functioning, but the reasons for and mechanisms behind variable dispersal rate - functioning patterns are currently unknown. In this study we used six bacterial lake water communities in a laboratory experiment.......e. their functional traits. From experiment (B) we could thus estimate changes in functional traits in communities in experiment (A). Bacterial production was affected by dispersal, but not consistently among lakes. Neither change in taxonomic or phylogenetic diversity with dispersal could explain the observed...

  6. Sensitivity of Climate Change Detection and Attribution to the Characterization of Internal Climate Variability

    KAUST Repository

    Imbers, Jara

    2014-05-01

    The Intergovernmental Panel on Climate Change\\'s (IPCC) "very likely" statement that anthropogenic emissions are affecting climate is based on a statistical detection and attribution methodology that strongly depends on the characterization of internal climate variability. In this paper, the authors test the robustness of this statement in the case of global mean surface air temperature, under different representations of such variability. The contributions of the different natural and anthropogenic forcings to the global mean surface air temperature response are computed using a box diffusion model. Representations of internal climate variability are explored using simple stochastic models that nevertheless span a representative range of plausible temporal autocorrelation structures, including the short-memory first-order autoregressive [AR(1)] process and the long-memory fractionally differencing process. The authors find that, independently of the representation chosen, the greenhouse gas signal remains statistically significant under the detection model employed in this paper. The results support the robustness of the IPCC detection and attribution statement for global mean temperature change under different characterizations of internal variability, but they also suggest that a wider variety of robustness tests, other than simple comparisons of residual variance, should be performed when dealing with other climate variables and/or different spatial scales. © 2014 American Meteorological Society.

  7. Multi-variable bias correction of RCMs for Climate Change Impact Studies

    Science.gov (United States)

    Yang, Wei; Olsson, Jonas; Bosshard, Thomas; Berg, Peter; Arheimer, Berit

    2014-05-01

    Climate change (CC) may have considerable influence on hydrology, forestry and other environmental management. Therefore, appropriate climate change inputs should be used for impact assessment conducted at regional and local scale. A main source for climate projections at high spatial resolutions is made available through Regional Climate Models (RCMs). However, although RCMs have improved over past years, their remaining systematic biases often constrain their direct use for impact studies. A distribution-based scaling (DBS) approach has been developed as a post-processing tool to adjust systematic biases in multiple variables in climate modelling outputs. The variables to be adjusted include primary hydrological inputs, precipitation and temperature, relative humidity, wind speed, short-wave solar radiation and long-wave solar radiation. The variables statistical properties (i.e. mean and standard deviation) and their distribution (i.e. PDF) are proved to be considerably improved after bias correction. Also, the DBS is found to better preserve the variability of the future climate produced by the RCM. The bias-adjusted variables are subsequently used as inputs to the Forest Weather Index (FWI) system at a number of locations in Sweden. The resulting FWIs show clear outperformance when compared to those calculated using raw climate model outputs in past and present climate, in particular, under extreme climate. The DBS is therefore thought to be helpful to provide realistic climate change inputs to impact modelling in CC impact studies.

  8. The Boltysh crater record of rapid vegetation change during the Dan-C2 hyperthermal event.

    Science.gov (United States)

    Jolley, D. W.; Daly, R.; Gilmour, I.; Gilmour, M.; Kelley, S. P.

    2012-04-01

    Analysis of a cored borehole drilled through the sedimentary fill of the 24km wide Boltysh meteorite crater, Ukraine has yielded a unique, high resolution record spanning gymnosperm - angiosperm - fern communities are replaced by precipitation limited (winterwet) plant communities within the negative CIE. Winterwet plant communities dominate the negative CIE, but are replaced within the isotope recovery stage by warm temperate floras. These in turn give way to cooler temperate floras in the post positive CIE section of the uppermost crater fill. The distribution of temperate taxa about the negative CIE represents the broadest scale of oscillatory variation in the palynofloras. Shorter frequency oscillations are evident from diversity and botanical group distributions reflecting changes in moisture availability over several thousand years. Detailed analysis of variability within one of these oscillations records plant community cyclicity across the inception of the negative CIE. This short term cyclicity provides evidence that the replacement of warm termperate by winterwet floras occurred in a stepwise manner at the negative CIE suggesting cumulative atmospheric forcing. At <1mm scale, lamination within the negative CIE showed no obvious lithological or colour differences, and are not seasonal couplets. However, palynofloral analysis of laminations from within the negative CIE has yielded evidence of annual variation identifying the potential for recoding changes in 'paleoweather' across a major hyperthermal event. [1] Jolley, D. W. et al. (2010) Geology 38, 835-838.

  9. Change and Variability in East Antarctic Sea Ice Seasonality, 1979/80?2009/10

    OpenAIRE

    Massom, Robert; Reid, Philip; Stammerjohn, Sharon; Raymond, Ben; Fraser, Alexander; Ushio, Shuki

    2013-01-01

    Recent analyses have shown that significant changes have occurred in patterns of sea ice seasonality in West Antarctica since 1979, with wide-ranging climatic, biological and biogeochemical consequences. Here, we provide the first detailed report on long-term change and variability in annual timings of sea ice advance, retreat and resultant ice season duration in East Antarctica. These were calculated from satellite-derived ice concentration data for the period 1979/80 to 2009/10. The pattern...

  10. Attenuation effect on seasonal basin-scale water storage changes from GRACE time-variable gravity

    OpenAIRE

    Chen, JL; Wilson, CR; Famiglietti, JS; Rodell, M.

    2007-01-01

    In order to effectively recover surface mass or geoid height changes from the gravity recovery and climate experiment (GRACE) time-variable gravity models, spatial smoothing is required to minimize errors from noise. Spatial smoothing, such as Gaussian smoothing, not only reduces the noise but also attenuates the real signals. Here we investigate possible amplitude attenuations and phase changes of seasonal water storage variations in four drainage basins (Amazon, Mississippi, Ganges and Zamb...

  11. Exemplar variability facilitates rapid learning of an otherwise unlearnable grammar by individuals with language-based learning disability.

    Science.gov (United States)

    von Koss Torkildsen, Janne; Dailey, Natalie S; Aguilar, Jessica M; Gómez, Rebecca; Plante, Elena

    2013-04-01

    Even without explicit instruction, learners are able to extract information about the form of a language simply by attending to input that reflects the underlying grammar. In this study, the authors explored the role of variability in this learning by asking whether varying the number of unique exemplars heard by the learner affects learning of an artificial syntactic form. Learners with normal language (n = 16) and language-based learning disability (LLD; n = 16) were exposed to strings of nonwords that represented an underlying grammar. Half of the learners heard 3 exemplars 16 times each (low variability group), and the other half of the learners heard 24 exemplars twice each (high variability group). Learners were then tested for recognition of items heard and generalization of the grammar with new nonword strings. Only those learners with LLD who were in the high variability group were able to demonstrate generalization of the underlying grammar. For learners with normal language, both those in the high and the low variability groups showed generalization of the grammar, but relative effect sizes suggested a larger learning effect in the high variability group. The results demonstrate that the structure of the learning context can determine the ability to generalize from specific training items to novel cases.

  12. Implications of climate variability for the detection of multiple equilibria and for rapid transitions in the atmosphere-vegetation system

    Energy Technology Data Exchange (ETDEWEB)

    Bathiany, S. [Max Planck Institute for Meteorology, Hamburg (Germany); Claussen, M. [Max Planck Institute for Meteorology, Hamburg (Germany); Universitaet Hamburg, Meteorologisches Institut, Hamburg (Germany); Fraedrich, K. [Universitaet Hamburg, Meteorologisches Institut, Hamburg (Germany)

    2012-05-15

    Paleoclimatic records indicate a decline of vegetation cover in the Western Sahara at the end of the African Humid Period (about 5,500 years before present). Modelling studies have shown that this phenomenon may be interpreted as a critical transition that results from a bifurcation in the atmosphere-vegetation system. However, the stability properties of this system are closely linked to climate variability and depend on the climate model and the methods of analysis. By coupling the Planet Simulator (PlaSim), an atmosphere model of intermediate complexity, with the simple dynamic vegetation model VECODE, we assess previous methods for the detection of multiple equilibria, and demonstrate their limitations. In particular, a stability diagram can yield misleading results because of spatial interactions, and the system's steady state and its dependency on initial conditions are affected by atmospheric variability and nonlinearities. In addition, we analyse the implications of climate variability for the abruptness of a vegetation decline. We find that a vegetation collapse can happen at different locations at different times. These collapses are possible despite large and uncorrelated climate variability. Because of the nonlinear relation between vegetation dynamics and precipitation the green state is initially stabilised by the high variability. When precipitation falls below a critical threshold, the desert state is stabilised as variability is then also decreased. (orig.)

  13. Modeling cavitation in a rapidly changing pressure field - application to a small ultrasonic horn.

    Science.gov (United States)

    Žnidarčič, Anton; Mettin, Robert; Dular, Matevž

    2015-01-01

    Ultrasonic horn transducers are frequently used in applications of acoustic cavitation in liquids. It has been observed that if the horn tip is sufficiently small and driven at high amplitude, cavitation is very strong, and the tip can be covered entirely by the gas/vapor phase for longer time intervals. A peculiar dynamics of the attached cavity can emerge with expansion and collapse at a self-generated frequency in the subharmonic range, i.e. below the acoustic driving frequency. The term "acoustic supercavitation" was proposed for this type of cavitation Žnidarčič et al. (2014) [1]. We tested several established hydrodynamic cavitation models on this problem, but none of them was able to correctly predict the flow features. As a specific characteristic of such acoustic cavitation problems lies in the rapidly changing driving pressures, we present an improved approach to cavitation modeling, which does not neglect the second derivatives in the Rayleigh-Plesset equation. Comparison with measurements of acoustic supercavitation at an ultrasonic horn of 20kHz frequency revealed a good agreement in terms of cavity dynamics, cavity volume and emitted pressure pulsations. The newly developed cavitation model is particularly suited for simulation of cavitating flow in highly fluctuating driving pressure fields. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Prevention and Control of Cardiovascular Disease in the Rapidly Changing Economy of China.

    Science.gov (United States)

    Wu, Yangfeng; Benjamin, Emelia J; MacMahon, Stephen

    2016-06-14

    With one-fifth of the world's total population, China's prevention and control of cardiovascular disease (CVD) may affect the success of worldwide efforts to achieve sustainable CVD reduction. Understanding China's current cardiovascular epidemic requires awareness of the economic development in the past decades. The rapid economic transformations (industrialization, marketization, urbanization, globalization, and informationalization) contributed to the aging demography, unhealthy lifestyles, and environmental changes. The latter have predisposed to increasing cardiovascular risk factors and the CVD pandemic. Rising CVD rates have had a major economic impact, which has challenged the healthcare system and the whole society. With recognition of the importance of health, initial political steps and national actions have been taken to address the CVD epidemic. Looking to the future, we recommend that 4 priorities should be taken: pursue multisectorial government and nongovernment strategies targeting the underlying causes of CVD (the whole-of-government and whole-of-society policy); give priority to prevention; reform the healthcare system to fit the nature of noncommunicable diseases; and conduct research for evidence-based, low-cost, simple, sustainable, and scalable interventions. By pursuing the 4 priorities, the pandemic of CVD and other major noncommunicable diseases in China will be reversed and the global sustainable development goal achieved. © 2016 American Heart Association, Inc.

  15. Dental and skeletal changes following surgically assisted rapid maxillary anterior-posterior expansion.

    Science.gov (United States)

    Ho, Cheng-Ting; Lo, Lun-Jou; Liou, Eric J W; Huang, Chiung Shing

    2008-01-01

    Lengthening the maxillary dental arch as a treatment approach for patients with maxillary deficiency and dental crowding is seldom reported. The purpose of this study was to assess dental and skeletal changes in the maxilla in the correction of maxillary deficiency associated with a retruded maxillary arch using a surgically assisted rapid maxillary anterior-posterior expansion appliance. Predistraction and postraction lateral cephalometric and periapical radiographs and maxillary dental casts of six young adolescents (four boys, two girls, mean age 11 years, 2 months) were examined. These patients received a maxillary anterior segmental osteotomy and distraction osteogenesis with an anteroposteriorly oriented Hyrax expansion appliance based on the biological principles of bone distraction. The retruded dental arch and dental crowding were successfully corrected. Significant forward movement of the point anterior nasal spine, point A, central incisors and first premolars was noted. The maxillary dental arch depth increased an average of 4.2 mm while the arch width remained unchanged. In total, 11.5 mm of dental space was created in the maxillary arch which was sufficient to resolve dental crowding. New bone formation along the distraction site was observed three months after distraction. The use of maxillary anterior segmental osteotomy combined with a Hyrax expansion distraction appliance was effective in arch lengthening and creation of dental space. An overcorrection in this interdental distraction osteogenesis could be a good treatment option for children with maxillary deficiency combined with crowded maxillary dentition.

  16. Rapid changes in genetic architecture of behavioural syndromes following colonization of a novel environment.

    Science.gov (United States)

    Karlsson Green, K; Eroukhmanoff, F; Harris, S; Pettersson, L B; Svensson, E I

    2016-01-01

    Behavioural syndromes, that is correlated behaviours, may be a result from adaptive correlational selection, but in a new environmental setting, the trait correlation might act as an evolutionary constraint. However, knowledge about the quantitative genetic basis of behavioural syndromes, and the stability and evolvability of genetic correlations under different ecological conditions, is limited. We investigated the quantitative genetic basis of correlated behaviours in the freshwater isopod Asellus aquaticus. In some Swedish lakes, A. aquaticus has recently colonized a novel habitat and diverged into two ecotypes, presumably due to habitat-specific selection from predation. Using a common garden approach and animal model analyses, we estimated quantitative genetic parameters for behavioural traits and compared the genetic architecture between the ecotypes. We report that the genetic covariance structure of the behavioural traits has been altered in the novel ecotype, demonstrating divergence in behavioural correlations. Thus, our study confirms that genetic correlations behind behaviours can change rapidly in response to novel selective environments. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  17. Rapid morphological oscillation of mitochondrion-rich cell in estuarine mudskipper following salinity changes.

    Science.gov (United States)

    Sakamoto, T; Yokota, S; Ando, M

    2000-05-01

    Morphological changes in the chloride cells or mitochondrion-rich (MR) cells in the skin under the pectoral fin of the estuarine mudskipper (Periophthalmus modestus) were examined in relation to intertidal salinity oscillation in river mouth. MR cells were distinguished between those in contact with the water (cells labeled with both mitochondrial probe DASPEI and Concanavalin-A, an apical surface marker of MR cells) and those that are not (DASPEI-positive only). After transfer of the fish from seawater to freshwater, no difference in the total MR cell density was observed, but the subpopulation of MR cells that are Concanavalin-A-positive decreased dramatically within 30 min. After 6 hr in freshwater, the fish were returned to seawater; the number of Con-A-positive MR cells increased to the initial levels rapidly. Thus, in seawater, mudskippers seem to open the apical crypts of the MR cells to secrete salt; in freshwater, they close the crypt of the MR cells tentatively, and tolerate hypotonicity until the rising tide. This unique response of chloride cells may also be seen in gills of other estuarine species.

  18. Rapid X-ray variability properties during the unusual very hard state in neutron-star low-mass X-ray binaries

    Science.gov (United States)

    Wijnands, R.; Parikh, A. S.; Altamirano, D.; Homan, J.; Degenaar, N.

    2017-11-01

    Here, we study the rapid X-ray variability (using XMM-Newton observations) of three neutron-star low-mass X-ray binaries (1RXS J180408.9-342058, EXO 1745-248 and IGR J18245-2452) during their recently proposed very hard spectral state. All our systems exhibit a strong to very strong noise component in their power density spectra (rms amplitudes ranging from 34 per cent to 102 per cent) with very low characteristic frequencies (as low as 0.01 Hz). These properties are more extreme than what is commonly observed in the canonical hard state of neutron-star low-mass X-ray binaries observed at X-ray luminosities similar to those we observe from our sources. This suggests that indeed the very hard state is a spectral-timing state distinct from the hard state, although we argue that the variability behaviour of IGR J18245-2452 is very extreme and possibly this source was in a very unusual state. We also compare our results with the rapid X-ray variability of the accreting millisecond X-ray pulsars IGR J00291+5934 and Swift J0911.9-6452 (also using XMM-Newton data) for which previously similar variability phenomena were observed. Although their energy spectra (as observed using the Swift X-ray telescope) were not necessarily as hard (i.e. for Swift J0911.9-6452) as for our other three sources, we conclude that likely both sources were also in very similar state during their XMM-Newton observations. This suggests that different sources that are found in this new state might exhibit different spectral hardness and one has to study both the spectral and the rapid variability to identify this unusual state.

  19. Volumetric upper airway changes after rapid maxillary expansion: a systematic review and meta-analysis.

    Science.gov (United States)

    Buck, Lloyd M; Dalci, Oyku; Darendeliler, M Ali; Papageorgiou, Spyridon N; Papadopoulou, Alexandra K

    2017-10-01

    Although Rapid Maxillary Expansion (RME) has been used for over a century, its effect on upper airways has not yet adequately been assessed in an evidence-based manner. To investigate the volumetric changes in the upper airway spaces following RME in growing subjects by means of acoustic rhinometry, three-dimensional radiography and digital photogrammetry. Literature search of electronic databases and additional manual searches up to February 2016. Randomized clinical trials, prospective or retrospective controlled clinical trials and cohort clinical studies of at least eight patients, where the RME appliance was left in place for retention, and a maximum follow-up of 8 months post-expansion. After duplicate data extraction and assessment of the risk of bias, the mean differences and 95 per cent confidence intervals (CIs) of upper airway volume changes were calculated with random-effects meta-analyses, followed by subgroup analyses, meta-regressions, and sensitivity analyses. Twenty studies were eligible for qualitative synthesis, of which 17 (3 controlled clinical studies and 14 cohort studies) were used in quantitative analysis. As far as total airway volume is concerned patients treated with RME showed a significant increase post-expansion (5 studies; increase from baseline: 1218.3mm3; 95 per cent CI: 702.0 to 1734.6mm3), which did not seem to considerably diminish after the retention period (11 studies; increase from baseline: 1143.9mm3; 95 per cent CI: 696.9 to 1590.9mm3). However, the overall quality of evidence was judged as very low, due to methodological limitations of the included studies, absence of untreated control groups, and inconsistency among studies. RME seems to be associated with an increase in the nasal cavity volume in the short and in the long term. However, additional well-conducted prospective controlled clinical studies are needed to confirm the present findings. None. Australian Society of Orthodontics Foundation for Research and

  20. Collaborative Proposal: Improving Decadal Prediction of Arctic Climate Variability and Change Using a Regional Arctic System Model (RASM)

    Energy Technology Data Exchange (ETDEWEB)

    Maslowski, Wieslaw [Naval Postgraduate School, Monterey, CA (United States)

    2016-10-17

    This project aims to develop, apply and evaluate a regional Arctic System model (RASM) for enhanced decadal predictions. Its overarching goal is to advance understanding of the past and present states of arctic climate and to facilitate improvements in seasonal to decadal predictions. In particular, it will focus on variability and long-term change of energy and freshwater flows through the arctic climate system. The project will also address modes of natural climate variability as well as extreme and rapid climate change in a region of the Earth that is: (i) a key indicator of the state of global climate through polar amplification and (ii) which is undergoing environmental transitions not seen in instrumental records. RASM will readily allow the addition of other earth system components, such as ecosystem or biochemistry models, thus allowing it to facilitate studies of climate impacts (e.g., droughts and fires) and of ecosystem adaptations to these impacts. As such, RASM is expected to become a foundation for more complete Arctic System models and part of a model hierarchy important for improving climate modeling and predictions.

  1. Coastal regime shifts: rapid responses of coastal wetlands to changes in mangrove cover.

    Science.gov (United States)

    Guo, Hongyu; Weaver, Carolyn; Charles, Sean P; Whitt, Ashley; Dastidar, Sayantani; D'Odorico, Paolo; Fuentes, Jose D; Kominoski, John S; Armitage, Anna R; Pennings, Steven C

    2017-03-01

    Global changes are causing broad-scale shifts in vegetation communities worldwide, including coastal habitats where the borders between mangroves and salt marsh are in flux. Coastal habitats provide numerous ecosystem services of high economic value, but the consequences of variation in mangrove cover are poorly known. We experimentally manipulated mangrove cover in large plots to test a set of linked hypotheses regarding the effects of changes in mangrove cover. We found that changes in mangrove cover had strong effects on microclimate, plant community, sediment accretion, soil organic content, and bird abundance within 2 yr. At higher mangrove cover, wind speed declined and light interception by vegetation increased. Air and soil temperatures had hump-shaped relationships with mangrove cover. The cover of salt marsh plants decreased at higher mangrove cover. Wrack cover, the distance that wrack was distributed from the water's edge, and sediment accretion decreased at higher mangrove cover. Soil organic content increased with mangrove cover. Wading bird abundance decreased at higher mangrove cover. Many of these relationships were non-linear, with the greatest effects when mangrove cover varied from zero to intermediate values, and lesser effects when mangrove cover varied from intermediate to high values. Temporal and spatial variation in measured variables often peaked at intermediate mangrove cover, with ecological consequences that are largely unexplored. Because different processes varied in different ways with mangrove cover, the "optimum" cover of mangroves from a societal point of view will depend on which ecosystem services are most desired. © 2016 by the Ecological Society of America.

  2. Climate Variability and Change since 850 CE: An Ensemble Approach with the Community Earth System Model

    National Research Council Canada - National Science Library

    Otto-Bliesner, Bette L; Brady, Esther C; Fasullo, John; Jahn, Alexandra; Landrum, Laura; Stevenson, Samantha; Rosenbloom, Nan; Mai, Andrew; Strand, Gary

    2016-01-01

    ... forced with the transient evolution of solar intensity, volcanic emissions, greenhouse gases, aerosols, land-use conditions, and orbital parameters, both together and individually. The CESM-LME thus allows for evaluation of the relative contributions of external forcing and internal variability to changes evident in the paleoclimate da...

  3. Adaptation strategies to climate change and climate variability: A comparative study between seven contrasting river basins

    NARCIS (Netherlands)

    Droogers, P.; Aerts, J.C.J.H.

    2005-01-01

    Adaptation strategies to climate change and climate variability to enhance food quantity and security and environmental quality and security have been explored for seven contrasting basins in the context of the ADAPT project. For the seven basins as much as possible established modeling frameworks

  4. Impacts of Climate Variability and Change on Banana Yields in the ...

    African Journals Online (AJOL)

    Climate variability and change are existing sets of conditions which affect crop productivity. An evaluation of their impacts on banana yield in the CDC-DelMonte Banana Project at Tiko is fundamental in conceiving adaptation strategies towards coping with, and minimizing their deleterious impacts for maximum productivity ...

  5. Local variability mediates vulnerability of trout populations to land use and climate change

    Science.gov (United States)

    Brooke E. Penaluna; Jason B. Dunham; Steve F. Railsback; Ivan Arismendi; Sherri L. Johnson; Robert E. Bilby; Mohammad Safeeq; Arne E. Skaugset; James P. Meador

    2015-01-01

    Land use and climate change occur simultaneously around the globe. Fully understanding their separate and combined effects requires a mechanistic understanding at the local scale where their effects are ultimately realized. Here we applied an individual-based model of fish population dynamics to evaluate the role of local stream variability in modifying responses of...

  6. Impacts of Climate Change and Variability on Water Resources in the Southeast USA

    Science.gov (United States)

    Ge Sun; Peter V. Caldwell; Steven G. McNulty; Aris P. Georgakakos; Sankar Arumugam; James Cruise; Richard T. McNider; Adam Terando; Paul A. Conrads; John Feldt; Vasu Misra; Luigi Romolo; Todd C. Rasmussen; Daniel A. Marion

    2013-01-01

    Key FindingsClimate change is affecting the southeastern USA, particularly increases in rainfall variability and air temperature, which have resulted in more frequent hydrologic extremes, such as high‐intensity storms (tropical storms and hurricanes), flooding, and drought events.Future climate warming likely will...

  7. Land Change Trends in the Great Plains: Linkages to Climate Variability and Socioeconomic Drivers

    Science.gov (United States)

    Drummond, M. A.

    2009-12-01

    Land use and land cover change have complex linkages to climate variability and change, socioeconomic driving forces, and land management challenges. To assess these land change dynamics and their driving forces in the Great Plains, we compare and contrast contemporary land conversion across seventeen ecoregions using Landsat remote sensing data and statistical analysis. Large area change analysis in agricultural regions is often hampered by the potential for substantial change detection error and the tendency for land conversions to occur in relatively small patches at the local level. To facilitate a regional scale analysis, a statistical sampling design of randomly selected 10-km by 10-km blocks is used in order to efficiently identify the types and rates of land conversions for four time periods between 1972 and 2000, stratified by relatively homogenous ecoregions. Results show a range of rates and processes of land change that vary by ecoregion contingent on the prevailing interactions between socioeconomic and environmental factors such as climate variability, water availability, and land quality. Ecoregions have differential climate and biophysical advantages for agricultural production and other land use change. Human actions further strengthen or dampen the characteristics of change through farm policy, technological advances, economic opportunities, population and demographic shifts, and surface and groundwater irrigation.

  8. Local Perceptions and Responses to Climate Change and Variability: The Case of Laikipia District, Kenya

    Directory of Open Access Journals (Sweden)

    Sarah Ayeri Ogalleh

    2012-12-01

    Full Text Available Agricultural policies in Kenya aim to improve farmers’ livelihoods. With projected climate change, these policies are short of mechanisms that promote farmers’ adaptation. As a result, smallholders are confronted with a variety of challenges including climate change, which hinders their agricultural production. Local knowledge can be instrumental in assisting smallholders to cope with climate change and variability. In this paper, we present empirical evidence that demonstrates local knowledge, perceptions and adaptations to climate change and variability amongst smallholders of Laikipia district of Kenya. A Palmer Drought Severity Index (PDSI calculated for one station is compared with smallholders’ perceptions. Data was collected using qualitative and quantitative methods in Umande and Muhonia sub-locations. Qualitative data included 46 transcripts from focus group discussions and key informant interviews. Quantitative data is derived from 206 interviewees. We analyzed qualitative and quantitative data using Atlas-ti and SPSS respectively. According to smallholders’ perceptions, climatic variability is increasingly changing. Local perceptions include decreasing rainfalls, increasing temperatures, increasing frosts and increasing hunger. The PDSI shows a trend towards severe droughts in the last four decades, which is in accordance with farmers’ perceptions. Smallholders use a combination of coping and adaptation strategies to respond to variability, including, among others, diversification of crop varieties, migration and sale of livestock. Significant relationships exist between drought perceptions and some adaptations such as migration and sale of livestock. Farmers have an in-depth knowledge of climatic variability, which they use to inform their coping and adaptation strategies. Knowledge of climatic perceptions and adaptations are vital entry points for decision makers and policy makers to learn how and where to enhance the

  9. Stakeholder perspectives on triage in wildlife monitoring in a rapidly changing Arctic

    Directory of Open Access Journals (Sweden)

    Helen C Wheeler

    2016-11-01

    Full Text Available Monitoring activities provide a core contribution to wildlife conservation in the Arctic. Effective monitoring which allows changes in population status to be detected early, provides opportunities to mitigate pressures driving declines. Monitoring triage involves decisions about how and where to prioritise activities in species and ecosystem based monitoring. In particular, monitoring triage examines whether to divert resources away from species where there is high likelihood of extinction in the near-future in favour of species where monitoring activities may produce greater conservation benefits. As a place facing both rapid change with a high likelihood of population extinctions, and serious logistic and financial challenges for field data acquisition, the Arctic provides a good context in which to examine attitudes toward triage in monitoring.For effective decision-making to emerge from monitoring, multiple stakeholders must be involved in defining aims and priorities. We conducted semi-structured interviews with stakeholders in arctic wildlife monitoring (either contributing to observation and recording of wildlife, using information from wildlife observation and recording, or using wildlife as a resource to elicit their perspectives on triage in wildlife monitoring in the Arctic.The majority (56% of our 23 participants were predominantly in opposition to triage, 26% were in support of triage and 17% were undecided. Representatives of Indigenous organisations were more likely to be opposed to triage than scientists and those involved in decision-making showed greatest support for triage amongst the scientist participants. Responses to the concept of triage included that: 1 The species-focussed approach associated with triage did not match their more systems-based view (5 participants, 2 Important information is generated through monitoring threatened species which advances understanding of the drivers of change, responses and ecosystem

  10. Comparing measurement error correction methods for rate-of-change exposure variables in survival analysis.

    Science.gov (United States)

    Veronesi, Giovanni; Ferrario, Marco M; Chambless, Lloyd E

    2013-12-01

    In this article we focus on comparing measurement error correction methods for rate-of-change exposure variables in survival analysis, when longitudinal data are observed prior to the follow-up time. Motivational examples include the analysis of the association between changes in cardiovascular risk factors and subsequent onset of coronary events. We derive a measurement error model for the rate of change, estimated through subject-specific linear regression, assuming an additive measurement error model for the time-specific measurements. The rate of change is then included as a time-invariant variable in a Cox proportional hazards model, adjusting for the first time-specific measurement (baseline) and an error-free covariate. In a simulation study, we compared bias, standard deviation and mean squared error (MSE) for the regression calibration (RC) and the simulation-extrapolation (SIMEX) estimators. Our findings indicate that when the amount of measurement error is substantial, RC should be the preferred method, since it has smaller MSE for estimating the coefficients of the rate of change and of the variable measured without error. However, when the amount of measurement error is small, the choice of the method should take into account the event rate in the population and the effect size to be estimated. An application to an observational study, as well as examples of published studies where our model could have been applied, are also provided.

  11. Women's role in adapting to climate change and variability

    Directory of Open Access Journals (Sweden)

    Y. Carvajal-Escobar

    2008-04-01

    Full Text Available Given that women are engaged in more climate-related change activities than what is recognized and valued in the community, this article highlights their important role in the adaptation and search for safer communities, which leads them to understand better the causes and consequences of changes in climatic conditions. It is concluded that women have important knowledge and skills for orienting the adaptation processes, a product of their roles in society (productive, reproductive and community; and the importance of gender equity in these processes is recognized. The relationship among climate change, climate variability and the accomplishment of the Millennium Development Goals is considered.

  12. Assessing conservation relevance of organism-environment relations using predicted changes in response variables

    Science.gov (United States)

    Gutzwiller, Kevin J.; Barrow, Wylie C.; White, Joseph D.; Johnson-Randall, Lori; Cade, Brian S.; Zygo, Lisa M.

    2010-01-01

    1. Organism–environment models are used widely in conservation. The degree to which they are useful for informing conservation decisions – the conservation relevance of these relations – is important because lack of relevance may lead to misapplication of scarce conservation resources or failure to resolve important conservation dilemmas. Even when models perform well based on model fit and predictive ability, conservation relevance of associations may not be clear without also knowing the magnitude and variability of predicted changes in response variables. 2. We introduce a method for evaluating the conservation relevance of organism–environment relations that employs confidence intervals for predicted changes in response variables. The confidence intervals are compared to a preselected magnitude of change that marks a threshold (trigger) for conservation action. To demonstrate the approach, we used a case study from the Chihuahuan Desert involving relations between avian richness and broad-scale patterns of shrubland. We considered relations for three winters and two spatial extents (1- and 2-km-radius areas) and compared predicted changes in richness to three thresholds (10%, 20% and 30% change). For each threshold, we examined 48 relations. 3. The method identified seven, four and zero conservation-relevant changes in mean richness for the 10%, 20% and 30% thresholds respectively. These changes were associated with major (20%) changes in shrubland cover, mean patch size, the coefficient of variation for patch size, or edge density but not with major changes in shrubland patch density. The relative rarity of conservation-relevant changes indicated that, overall, the relations had little practical value for informing conservation decisions about avian richness. 4. The approach we illustrate is appropriate for various response and predictor variables measured at any temporal or spatial scale. The method is broadly applicable across ecological

  13. Do physiological and pathological stresses produce different changes in heart rate variability?

    Directory of Open Access Journals (Sweden)

    Andrea eBravi

    2013-07-01

    Full Text Available Although physiological (e.g. exercise and pathological (e.g. infection stress affecting the cardiovascular system have both been documented to be associated with a reduction in overall heart rate variability (HRV, it remains unclear if loss of HRV is ubiquitously similar across different domains of variability analysis or if distinct patterns of altered HRV exist depending on the stressor. Using Continuous Individualized Multiorgan Variability Analysis (CIMVATM software, heart rate (HR and four selected measures of variability were measured over time (windowed analysis from two datasets, a set (n=13 of patients who developed systemic infection (i.e. sepsis after bone marrow transplant, and a matched set of healthy subjects undergoing physical exercise under controlled conditions. HR and the four HRV measures showed similar trends in both sepsis and exercise. The comparison through Wilcoxon sign-rank test of the levels of variability at baseline and during the stress (i.e. exercise or after days of sepsis development showed similar changes, except for LF/HF, ratio of power at low and high frequencies (associated with sympathovagal modulation, which was affected by exercise but did not show any change during sepsis. Furthermore, HRV measures during sepsis showed a lower level of correlation with each other, as compared to HRV during exercise. In conclusion, this exploratory study highlights similar responses during both exercise and infection, with differences in terms of correlation and inter-subject fluctuations, whose physiologic significance merits further investigation.

  14. Understanding Chemical Change in Primary Education: The Effect of Two Cognitive Variables

    Science.gov (United States)

    Stamovlasis, Dimitrios; Papageorgiou, George

    2011-11-01

    In this study, pupils' understanding of chemical change was investigated in relation to two cognitive variables: logical thinking and field-dependence/field-independence. The participants (N = 99) were sixth-grade elementary school pupils (aged 11/12), which were involved in two different tasks related to combustion. The pupils were tested for their understanding by means of an instrument, where they were asked to describe and interpret the phenomenon. The application of multiple regressions on students' mean achievement score along with analysis of variance demonstrated that the above variables were statistically significant predictors with logical thinking to be the most dominant one. Moreover, a distinction between items emphasizing description and items emphasizing interpretation were made and the effects of the cognitive variables were determined. Path analysis was implemented to depict these hypothesized direct and indirect effects among variables. The findings contribute to the literature by providing empirical evidence that the above individual differences have an effect on pupils' understanding the phenomenon of chemical change at that critical age. Implications for science education are also discussed and it is pointed out that cognitive variables, such as, logical thinking and field-dependence/field-independence should not be ignored in potential teaching interventions. Moreover, theoretical contribution is given by showing that neo-Piagetian theories provide a coherent framework for understanding students' performance in science education.

  15. Monitoring of two rapidly changing glacier tongues in the Swiss Alps by new drone data and historical documents

    Science.gov (United States)

    Nussbaumer, Samuel U.; Jörg, Philip C.; Gärtner-Roer, Isabelle; Rastner, Philipp; Ruff, Alexander; Steiner, Daniel; Vieli, Andreas; Zumbühl, Heinz J.

    2015-04-01

    Glaciers are considered among the most sensitive indicators of climate change. One of the most visually compelling examples of recent climate change is the retreat of glaciers in mountain regions, and knowledge about the past evolution of glacier fluctuations has been proven to be crucial for studying past decadal to century-scale climate variability. In this presentation, we evaluate the potential of a light fixed-wing UAV (unmanned aerial vehicle; drone) designed for surveying and remote sensing purposes, for monitoring glacier changes. We focus on the frontal zones of two well-known glaciers in the Swiss Alps: Unterer Grindelwaldgletscher in the Bernese Oberland, and Findelengletscher near Zermatt, Valais. We used a professional mapping drone (eBee by senseFly) to cover both frontal areas of the glaciers in the summer/autumn of 2014. We used a Canon IXUS 125HS RGB camera on-board the drone to collect overlapping nadir images for both study sites. For Unterer Grindelwaldgletscher (Findelengletscher), 187 (421) images were taken for a surveyed area of 3.2 km2 (2.9 km2) resulting in digital surface models and orthophotos with a very high spatial resolution of 0.16 m (0.11 m). The high number of images collected per area resulted in accurate elevation models and no detectable systematic horizontal shifts. Analysis of these images reveal in great detail the typical processes and features known for down-wasting and rapidly disintegrating Alpine glacier tongues: formation of (pro-)glacial lakes, dead ice, thermokarst phenomena, collapse of lateral moraines, and a complex interplay between many of those processes. Typically glacio-fluvial, gravitational, and periglacial processes occur in close vicinity and on different temporal scales (continuous, sporadic). We compare both glacier landscapes and address the important processes identified to be responsible for the glacier change at both sites. Finally, to set the observed geomorphological processes and the rapid

  16. Incorporating climate change trends to near future variability of crop yields in Iberia Peninsula

    Science.gov (United States)

    Capa-Morocho, Mirian; Baethgen, Walter E.; Fernandes, Kátia; Rodríguez-Fonseca, Belén; Ruiz-Ramos, Margarita

    2016-04-01

    In this study, we analyze the effects of near future climate variability on cropping systems in Iberian Peninsula (IP). For this purpose, we generated climate sequences that simulate realistic variability on annual to decadal time scales. The sequences incorporate nonlinear climate change trends, using statistical methods and and an ensemble of global climate models from the Coupled Model Intercomparison Project (CMIP5). Then, the climate sequences are temporal downscaled into daily weather data and used as inputs to crop models. As case study, we evaluate the impacts of plausible future climate scenarios on rain-fed wheat yield two agricultural locations in IP. We adapted the method by Greene et al., (2012 and 2015) for informing climate projections for the coming decades with a combination of seasonal to interannual and anthropogenically forced climate change information for accounting the Near-term Climate Change. Long-term data containing solar radiation, maximum and minimum temperature and rainfall are needed to apply this method. The climate variability observed was decomposed into long-range trend, decadal and interannual variability to understand the relative importance of each time scale. The interannual variability was modeled based on the observational records. The results of this study may have important implications on public and private sectors to analyze the probabilistic projections of impacts and agronomic adaptations of near future climate variability in Iberian Peninsula. This study has been funded by MACSUR project from FACCE-JPI. References Greene, A.M., Goddard, L., Gonzalez, P.L., Ines, A.V. and Chryssanthacopoulos, J., 2015.A climate generator for agricultural planning in southeastern South America.Agricultural and Forest Meteorology, 203: 217-228. Greene, A.M., Hellmuth, M. and Lumsden, T., 2012. Stochastic decadal climate simulations for the Berg and Breede water management areas, western Cape province, South Africa. Water Resources

  17. Climate Informed Economic Instruments to Enhance Urban Water Supply Resilience to Hydroclimatological Variability and Change

    Science.gov (United States)

    Brown, C.; Carriquiry, M.; Souza Filho, F. A.

    2006-12-01

    Hydroclimatological variability presents acute challenges to urban water supply providers. The impact is often most severe in developing nations where hydrologic and climate variability can be very high, water demand is unmet and increasing, and the financial resources to mitigate the social effects of that variability are limited. Furthermore, existing urban water systems face a reduced solution space, constrained by competing and conflicting interests, such as irrigation demand, recreation and hydropower production, and new (relative to system design) demands to satisfy environmental flow requirements. These constraints magnify the impacts of hydroclimatic variability and increase the vulnerability of urban areas to climate change. The high economic and social costs of structural responses to hydrologic variability, such as groundwater utilization and the construction or expansion of dams, create a need for innovative alternatives. Advances in hydrologic and climate forecasting, and the increasing sophistication and acceptance of incentive-based mechanisms for achieving economically efficient water allocation offer potential for improving the resilience of existing water systems to the challenge of variable supply. This presentation will explore the performance of a system of climate informed economic instruments designed to facilitate the reduction of hydroclimatologic variability-induced impacts on water-sensitive stakeholders. The system is comprised of bulk water option contracts between urban water suppliers and agricultural users and insurance indexed on reservoir inflows designed to cover the financial needs of the water supplier in situations where the option is likely to be exercised. Contract and insurance parameters are linked to forecasts and the evolution of seasonal precipitation and streamflow and designed for financial and political viability. A simulation of system performance is presented based on ongoing work in Metro Manila, Philippines. The

  18. Fluvial response to the last Holocene rapid climate change in the Northwestern Mediterranean coastlands

    Science.gov (United States)

    Degeai, Jean-Philippe; Devillers, Benoît; Blanchemanche, Philippe; Dezileau, Laurent; Oueslati, Hamza; Tillier, Margaux; Bohbot, Hervé

    2017-05-01

    The variability of fluvial activity in the Northwestern Mediterranean coastal lowlands and its relationship with modes of climate change were analysed from the late 9th to the 18th centuries CE. Geochemical analyses were undertaken from a lagoonal sequence and surrounding sediments in order to track the fluvial inputs into the lagoon. An index based on the K/S and Rb/S ratios was used to evidence the main periods of fluvial activity. This index reveals that the Medieval Climate Anomaly (MCA) was a drier period characterized by a lower fluvial activity, while the Little Ice Age (LIA) was a wetter period with an increase of the river dynamics. Three periods of higher than average fluvial activity were evidenced at the end of the first millennium CE (ca. 900-950 cal yr CE), in the first half of the second millennium CE (ca. 1150-1550 cal yr CE), and during the 1600s-1700s CE (ca. 1650-1800 cal yr CE). The comparison of these fluvial periods with other records of riverine or lacustrine floods in Spain, Italy, and South of France seems to indicate a general increase in fluvial and flood patterns in the Northwestern Mediterranean in response to the climate change from the MCA to the LIA, although some episodes of flooding are not found in all records. Besides, the phases of higher than average fluvial dynamics are in good agreement with the North Atlantic cold events evidenced from records of ice-rafted debris. The evolution of fluvial activity in the Northwestern Mediterranean coastlands during the last millennium could have been driven by atmospheric and oceanic circulation patterns.

  19. Transcranial Random Noise Stimulation (tRNS Shapes the Processing of Rapidly Changing Auditory Information

    Directory of Open Access Journals (Sweden)

    Katharina S. Rufener

    2017-06-01

    Full Text Available Neural oscillations in the gamma range are the dominant rhythmic activation pattern in the human auditory cortex. These gamma oscillations are functionally relevant for the processing of rapidly changing acoustic information in both speech and non-speech sounds. Accordingly, there is a tight link between the temporal resolution ability of the auditory system and inherent neural gamma oscillations. Transcranial random noise stimulation (tRNS has been demonstrated to specifically increase gamma oscillation in the human auditory cortex. However, neither the physiological mechanisms of tRNS nor the behavioral consequences of this intervention are completely understood. In the present study we stimulated the human auditory cortex bilaterally with tRNS while EEG was continuously measured. Modulations in the participants’ temporal and spectral resolution ability were investigated by means of a gap detection task and a pitch discrimination task. Compared to sham, auditory tRNS increased the detection rate for near-threshold stimuli in the temporal domain only, while no such effect was present for the discrimination of spectral features. Behavioral findings were paralleled by reduced peak latencies of the P50 and N1 component of the auditory event-related potentials (ERP indicating an impact on early sensory processing. The facilitating effect of tRNS was limited to the processing of near-threshold stimuli while stimuli clearly below and above the individual perception threshold were not affected by tRNS. This non-linear relationship between the signal-to-noise level of the presented stimuli and the effect of stimulation further qualifies stochastic resonance (SR as the underlying mechanism of tRNS on auditory processing. Our results demonstrate a tRNS related improvement in acoustic perception of time critical auditory information and, thus, provide further indices that auditory tRNS can amplify the resonance frequency of the auditory system.

  20. Traps as treats: a traditional sticky rice snack persisting in rapidly changing Asian kitchens.

    Science.gov (United States)

    Schwallier, Rachel; de Boer, Hugo J; Visser, Natasja; van Vugt, Rogier R; Gravendeel, Barbara

    2015-03-24

    An accessory to modern developing economies includes a shift from traditional, laborious lifestyles and cuisine to more sedentary careers, recreation and convenience-based foodstuffs. Similar changes in the developed western world have led to harmful health consequences. Minimization of this effect in current transitional cultures could be met by placing value on the maintenance of heritage-rich food. Vitally important to this is the preservation and dissemination of knowledge of these traditional foods. Here, we investigate the history and functionality of a traditional rice snack cooked in Nepenthes pitchers, one of the most iconic and recognizable plants in the rapidly growing economic environment of Southeast Asia. Social media was combined with traditional ethnobotanical surveys to conduct investigations throughout Malaysian Borneo. Interviews were conducted with 25 market customers, vendors and participants from various ethnical groups with an in-depth knowledge of glutinous rice cooked in pitcher plants. The acidity of pitcher fluid was measured during experimental cooking to analyze possible chemical avenues that might contribute to rice stickiness. Participants identifying the snack were almost all (96%) from indigenous Bidayuh or Kadazandusun tribal decent. They prepare glutinous rice inside pitcher traps for tradition, vessel functionality and because they thought it added fragrance and taste to the rice. The pH and chemical activity of traps analyzed suggest there is no corresponding effect on rice consistency. Harvest of pitchers does not appear to decrease the number of plants in local populations. The tradition of cooking glutinous rice snacks in pitcher plants, or peruik kera in Malay, likely carries from a time when cooking vessels were more limited, and persists only faintly in tribal culture today because of value placed on maintaining cultural heritage. Social media proved a valuable tool in our research for locating research areas and in

  1. Extremely rapid directional change during Matuyama-Brunhes geomagnetic polarity reversal

    Science.gov (United States)

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

    2014-11-01

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

  2. Rapid Changes in CB1 Receptor Availability in Cannabis Dependent Males after Abstinence from Cannabis.

    Science.gov (United States)

    D'Souza, Deepak Cyril; Cortes-Briones, Jose A; Ranganathan, Mohini; Thurnauer, Halle; Creatura, Gina; Surti, Toral; Planeta, Beata; Neumeister, Alexander; Pittman, Brian; Normandin, Marc; Kapinos, Michael; Ropchan, Jim; Huang, Yiyun; Carson, Richard E; Skosnik, Patrick D

    2016-01-01

    The widespread use of cannabis, the increasing legalization of "medical" cannabis, the increasing potency of cannabis and the growing recreational use of synthetic cannabinoid 1 receptor (CB1R) full agonists underscores the importance of elucidating the effects of cannabinoids on the CB1R system. Exposure to cannabinoids is known to result in CB1R downregulation. However, the precise time course of changes in CB1R availability in cannabis dependent subjects (CDs) following short and intermediate term abstinence has not been determined. Using High Resolution Research Tomography (HRRT) and [(11)C]OMAR, CB1R availability as indexed by the volume of distribution (VT) [(11)C]OMAR was measured in male CDs (n=11) and matched healthy controls (HCs) (n=19). CDs were scanned at baseline (while they were neither intoxicated nor in withdrawal), and after 2 days and 28 days of monitored abstinence. HCs were scanned at baseline and a subset (n=4) was rescanned 28 days later. Compared to HCs, [(11)C]OMAR VT was 15% lower in CDs (effect size Cohen's d=-1.11) at baseline in almost all brain regions. However, these group differences in CB1R availability were no longer evident after just 2 days of monitored abstinence from cannabis. There was a robust negative correlation between CB1R availability and withdrawal symptoms after 2 days of abstinence. Finally, there were no significant group differences in CB1R availability in CDs after 28 days of abstinence. Cannabis dependence is associated with CB1R downregulation, which begins to reverse surprisingly rapidly upon termination of cannabis use and may continue to increase over time.

  3. Competition for cognitive resources during rapid serial processing: changes across childhood

    Directory of Open Access Journals (Sweden)

    Sabine eHeim

    2011-01-01

    Full Text Available The ability to direct cognitive resources to target objects despite distraction by competing information plays an important role for the development of mental aptitudes and skills. We examined developmental changes of this ability in a cross-sectional design, using the attentional blink (AB paradigm. The AB is a pronounced impairment of T2 report, which occurs when a first (T1 and second target (T2 embedded in a rapid stimulus sequence are separated by at least one distractor and occur within 500 ms of each other. Two groups of children (6 to 7 year-olds and 10 to 11 year-olds; ns = 21 and 24, respectively were asked to identify green targets in two AB tasks: one using non-linguistic symbols and the other letters or words. The temporal distance or stimulus-onset asynchrony (SOA between T1 and T2 varied between no intervening distractor (Lag 1, 116-ms SOA and up to 7 intervening distractors (Lag 8, 928-ms SOA. In the symbol task, younger children linearly increased T2 identification with increasing lag. Older children, however, displayed a hook-shaped pattern as typically seen in adults, with lowest identification reports in T2 symbols at the critical blink interval (Lag 2, 232-ms SOA, and a slight performance gain for the Lag-1 condition. In the verbal task, the older group again exhibited a prominent drop in T2 identification at Lag 2, whereas the younger group showed a more alleviated and temporally diffuse AB impairment. Taken together, this pattern of results suggests that the control of attention allocation and/or working memory consolidation of targets among distractors represents a cognitive skill that emerges during primary school age.

  4. Sensitivity of potential evapotranspiration to changes in climate variables for different Australian climatic zones

    Science.gov (United States)

    Guo, Danlu; Westra, Seth; Maier, Holger R.

    2017-04-01

    Assessing the factors that have an impact on potential evapotranspiration (PET) sensitivity to changes in different climate variables is critical to understanding the possible implications of climatic changes on the catchment water balance. Using a global sensitivity analysis, this study assessed the implications of baseline climate conditions on the sensitivity of PET to a large range of plausible changes in temperature (T), relative humidity (RH), solar radiation (Rs) and wind speed (uz). The analysis was conducted at 30 Australian locations representing different climatic zones, using the Penman-Monteith and Priestley-Taylor PET models. Results from both models suggest that the baseline climate can have a substantial impact on overall PET sensitivity. In particular, approximately 2-fold greater changes in PET were observed in cool-climate energy-limited locations compared to other locations in Australia, indicating the potential for elevated water loss as a result of increasing actual evapotranspiration (AET) in these locations. The two PET models consistently indicated temperature to be the most important variable for PET, but showed large differences in the relative importance of the remaining climate variables. In particular for the Penman-Monteith model, wind and relative humidity were the second-most important variables for dry and humid catchments, respectively, whereas for the Priestley-Taylor model solar radiation was the second-most important variable, with the greatest influence in warmer catchments. This information can be useful to inform the selection of suitable PET models to estimate future PET for different climate conditions, providing evidence on both the structural plausibility and input uncertainty for the alternative models.

  5. Local-scale changes in mean and heavy precipitation in Western Europe, climate change or internal variability?

    Science.gov (United States)

    Aalbers, Emma E.; Lenderink, Geert; van Meijgaard, Erik; van den Hurk, Bart J. J. M.

    2017-09-01

    High-resolution climate information provided by e.g. regional climate models (RCMs) is valuable for exploring the changing weather under global warming, and assessing the local impact of climate change. While there is generally more confidence in the representativeness of simulated processes at higher resolutions, internal variability of the climate system—`noise', intrinsic to the chaotic nature of atmospheric and oceanic processes—is larger at smaller spatial scales as well, limiting the predictability of the climate signal. To quantify the internal variability and robustly estimate the climate signal, large initial-condition ensembles of climate simulations conducted with a single model provide essential information. We analyze a regional downscaling of a 16-member initial-condition ensemble over western Europe and the Alps at 0.11° resolution, similar to the highest resolution EURO-CORDEX simulations. We examine the strength of the forced climate response (signal) in mean and extreme daily precipitation with respect to noise due to internal variability, and find robust small-scale geographical features in the forced response, indicating regional differences in changes in the probability of events. However, individual ensemble members provide only limited information on the forced climate response, even for high levels of global warming. Although the results are based on a single RCM-GCM chain, we believe that they have general value in providing insight in the fraction of the uncertainty in high-resolution climate information that is irreducible, and can assist in the correct interpretation of fine-scale information in multi-model ensembles in terms of a forced response and noise due to internal variability.

  6. Dual-energy synchrotron X ray measurements of rapid soil density and water content changes in swelling soils during infiltration

    Science.gov (United States)

    Garnier, Patricia; Angulo-Jaramillo, Rafael; DiCarlo, David A.; Bauters, Tim W. J.; Darnault, Christophe J. G.; Steenhuis, Tammo S.; Parlange, J.-Yves; Baveye, Philippe

    1998-11-01

    Understanding soil swelling is hampered by the difficulty of simultaneously measuring water content and bulk density. A number of studies have used dual-energy gamma rays to investigate soil swelling. The long counting time of this technique makes it impracticable for studying the rapid changes in moisture content and soil swelling shortly after infiltration is initiated. In this paper, we use the dual-energy synchrotron X ray to measure, for the first time, the water content and bulk density changes during the fast, initial phase of the swelling process. Ponded infiltration experiments were performed with two soils: a bentonite-sand mixture and a vertisol. Swelling curves and hydraulic diffusivity were determined. Deformation was very rapid immediately after water application and then became progressively slower. The hydraulic diffusivity decreased with time, which can partially explain the very rapid decrease in infiltration rates observed in the field.

  7. Changes in canopy structure and ant assemblages affect soil ecosystem variables as a foundation species declines

    DEFF Research Database (Denmark)

    Kendrick, Joseph A.; Ribbons, Relena Rose; Classen, Aimee Taylor

    2015-01-01

    , we built ant exclosure subplots within all of the canopy manipulation plots to examine direct and interactive effects of canopy change and ant assemblage composition on soil and litter variables. Throughout HF-HeRE, T. canadensis was colonized by the adelgid in 2009, and the infested trees are now...... declining. The experimental removal of T. canadensis from the canopy was associated with an increase in the rate of cellulose decomposition by >50%, and exclosure of ants from subplots directly reduced their soil nitrate availability by 56%. Partial least squares path models revealed sequential interactive...... effects prior to adelgid infestation: canopy change (as a proxy for associated environmental changes) altered both decomposition and ant assemblage structure; changes in ant assemblage structure and decomposition rates altered nitrogen availability. The results illustrate that biotic changes directly...

  8. Characterization of polymorphic solid-state changes using variable temperature X-ray powder diffraction

    DEFF Research Database (Denmark)

    Karjalainen, Milja; Airaksinen, Sari; Rantanen, Jukka

    2005-01-01

    The aim of this study was to use variable temperature X-ray powder diffraction (VT-XRPD) to understand the solid-state changes in the pharmaceutical materials during heating. The model compounds studied were sulfathiazole, theophylline and nitrofurantoin. This study showed that the polymorph form...... of sulfathiazole SUTHAZ01 was very stable and SUTHAZ02 changed as a function of temperature to SUTHAZ01. Theophylline monohydrate changed via its metastable form to its anhydrous form during heating and nitrofurantoin monohydrate changed via amorphous form to its anhydrous form during heating. The crystallinity...... of SUTHAZ01, SUTHAZ02 and theophylline monohydrate were very high and stable. Nitrofurantoin monohydrate was also very crystalline at room temperature but during heating at lower temperatures the crystallinity decreased and started to increase strongly at the temperature where the sample had changed...

  9. Organizational Adaptation to the Rapidly Changing External Environment: A Case Study of Strategic Marketing at Notre Dame College in Ohio

    Science.gov (United States)

    Brown, Shawn M.

    2012-01-01

    This thesis examined the role of strategic marketing in organizational adaptation to a rapidly changing and competitive external environment among institutions of higher education. Colleges and universities adapt to external pressures as open systems operating within a broader external environment (Bess & Dee, 2008; Keller, 1983). How does…

  10. Community reintegration of ex-prisoners: type and degree of change in variables influencing successful reintegration.

    Science.gov (United States)

    Shinkfield, Alison J; Graffam, Joseph

    2009-02-01

    Community reintegration of ex-prisoners is an important issue in efforts to reduce recidivism. The present study examined the multiple, complex, and dynamic nature of variables influencing successful reintegration by assessing the type and degree of change in reintegration variables over time. Participants were 79 adult prisoners (54 male, 25 female) who completed a prerelease questionnaire 1 month before their release, which focused on prison-related variables, participant background, and anticipated conditions upon release. A postrelease questionnaire was administered to the same participants at 1-4 weeks and 3-4 months postrelease, focusing on the quality of life conditions experienced following release. Results indicate that current health ratings and several indicators of drug use were significantly different over the three measurement phases. Ratings of employment and housing stability, finance, and social support were unchanged over the postrelease period. Theoretical implications of the present investigation for reintegration theory are discussed, together with practical applications.

  11. Rapid assessment of different oxygenic phototrophs and single-cell photosynthesis with multicolour variable chlorophyll fluorescence imaging

    DEFF Research Database (Denmark)

    Trampe, Erik Christian Løvbjerg; Kolbowski, J.; Schreiber, U.

    2011-01-01

    , red or white light. Automated sequential exposure of microscopic samples to the three excitation colours enables subsequent deconvolution of the resulting fluorescence signals and colour marking of cells with different photopigmentation, i.e., cyanobacteria, green algae, red algae and diatoms......We present a new system for microscopic multicolour variable chlorophyll fluorescence imaging of aquatic phototrophs. The system is compact and portable and enables microscopic imaging of photosynthetic performance of individual cells and chloroplasts using different combinations of blue, green...

  12. Recent changes in county-level corn yield variability in the United States from observations and crop models.

    Science.gov (United States)

    Leng, Guoyong

    2017-12-31

    The United States is responsible for 35% and 60% of global corn supply and exports. Enhanced supply stability through a reduction in the year-to-year variability of US corn yield would greatly benefit global food security. Important in this regard is to understand how corn yield variability has evolved geographically in the history and how it relates to climatic and non-climatic factors. Results showed that year-to-year variation of US corn yield has decreased significantly during 1980-2010, mainly in Midwest Corn Belt, Nebraska and western arid regions. Despite the country-scale decreasing variability, corn yield variability exhibited an increasing trend in South Dakota, Texas and Southeast growing regions, indicating the importance of considering spatial scales in estimating yield variability. The observed pattern is partly reproduced by process-based crop models, simulating larger areas experiencing increasing variability and underestimating the magnitude of decreasing variability. And 3 out of 11 models even produced a differing sign of change from observations. Hence, statistical model which produces closer agreement with observations is used to explore the contribution of climatic and non-climatic factors to the changes in yield variability. It is found that climate variability dominate the change trends of corn yield variability in the Midwest Corn Belt, while the ability of climate variability in controlling yield variability is low in southeastern and western arid regions. Irrigation has largely reduced the corn yield variability in regions (e.g. Nebraska) where separate estimates of irrigated and rain-fed corn yield exist, demonstrating the importance of non-climatic factors in governing the changes in corn yield variability. The results highlight the distinct spatial patterns of corn yield variability change as well as its influencing factors at the county scale. I also caution the use of process-based crop models, which have substantially underestimated

  13. Recent changes in county-level corn yield variability in the United States from observations and crop models

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Guoyong

    2017-12-01

    The United States is responsible for 35% and 60% of global corn supply and exports. Enhanced supply stability through a reduction in the year-to-year variability of US corn yield would greatly benefit global food security. Important in this regard is to understand how corn yield variability has evolved geographically in the history and how it relates to climatic and non-climatic factors. Results showed that year-to-year variation of US corn yield has decreased significantly during 1980-2010, mainly in Midwest Corn Belt, Nebraska and western arid regions. Despite the country-scale decreasing variability, corn yield variability exhibited an increasing trend in South Dakota, Texas and Southeast growing regions, indicating the importance of considering spatial scales in estimating yield variability. The observed pattern is partly reproduced by process-based crop models, simulating larger areas experiencing increasing variability and underestimating the magnitude of decreasing variability. And 3 out of 11 models even produced a differing sign of change from observations. Hence, statistical model which produces closer agreement with observations is used to explore the contribution of climatic and non-climatic factors to the changes in yield variability. It is found that climate variability dominate the change trends of corn yield variability in the Midwest Corn Belt, while the ability of climate variability in controlling yield variability is low in southeastern and western arid regions. Irrigation has largely reduced the corn yield variability in regions (e.g. Nebraska) where separate estimates of irrigated and rain-fed corn yield exist, demonstrating the importance of non-climatic factors in governing the changes in corn yield variability. The results highlight the distinct spatial patterns of corn yield variability change as well as its influencing factors at the county scale. I also caution the use of process-based crop models, which have substantially underestimated

  14. Non-linear regime shifts in Holocene Asian monsoon variability: potential impacts on cultural change and migratory patterns

    Science.gov (United States)

    Donges, J. F.; Donner, R. V.; Marwan, N.; Breitenbach, S. F. M.; Rehfeld, K.; Kurths, J.

    2015-05-01

    The Asian monsoon system is an important tipping element in Earth's climate with a large impact on human societies in the past and present. In light of the potentially severe impacts of present and future anthropogenic climate change on Asian hydrology, it is vital to understand the forcing mechanisms of past climatic regime shifts in the Asian monsoon domain. Here we use novel recurrence network analysis techniques for detecting episodes with pronounced non-linear changes in Holocene Asian monsoon dynamics recorded in speleothems from caves distributed throughout the major branches of the Asian monsoon system. A newly developed multi-proxy methodology explicitly considers dating uncertainties with the COPRA (COnstructing Proxy Records from Age models) approach and allows for detection of continental-scale regime shifts in the complexity of monsoon dynamics. Several epochs are characterised by non-linear regime shifts in Asian monsoon variability, including the periods around 8.5-7.9, 5.7-5.0, 4.1-3.7, and 3.0-2.4 ka BP. The timing of these regime shifts is consistent with known episodes of Holocene rapid climate change (RCC) and high-latitude Bond events. Additionally, we observe a previously rarely reported non-linear regime shift around 7.3 ka BP, a timing that matches the typical 1.0-1.5 ky return intervals of Bond events. A detailed review of previously suggested links between Holocene climatic changes in the Asian monsoon domain and the archaeological record indicates that, in addition to previously considered longer-term changes in mean monsoon intensity and other climatic parameters, regime shifts in monsoon complexity might have played an important role as drivers of migration, pronounced cultural changes, and the collapse of ancient human societies.

  15. Long-term changes and variability in rainfall and streamflow in Luvuvhu River Catchment, South Africa

    Directory of Open Access Journals (Sweden)

    John O. Odiyo

    2015-07-01

    Full Text Available We investigated long-term changes and variability in daily rainfall and streamflow in the Luvuvhu River Catchment, South Africa. Changes and variability in rainfall and streamflow impact on available water resources and the allocation of these resources. Daily rainfall data for six stations and daily streamflow data for four stations for the period 1920/1921�2005/2006 were grouped into cycles of 5 and 10 years. Daily means and standard deviations were computed for each cycle. Standard deviation was used to define the rainfall and streamflow variability. Linear regression was used to compute trends in 5- and 10-year average rainfall and streamflow and their standard deviations. Paired two-tailed�t-tests (significance level of 0.05 were carried out to verify the spatial variability of rainfall and streamflow in the study area. Mann�Kendall and linear regression were used to determine trend analyses based on long-term annual rainfall and streamflow data. All but two rainfall stations showed decreasing trends in 5- and 10-year mean rainfall; 10-year mean daily rainfall showed decadal rainfall fluctuations. Contrasting trends were observed in 5- and 10-year mean streamflow, indicating that other factors such as anthropogenic activities and impoundments could be impacting on streamflow. Trend directions identified from Mann-Kendall and linear regression analyses of long-term annual rainfall and streamflow were similar to those identified by linear regression of 5- and 10-year mean daily rainfall. Results of paired two-tailed�t-tests verified the spatial variability of rainfall and streamflow in the study area. We have shown that the variability of rainfall and streamflow has increased in the Luvuvhu River Catchment over the 86-year study period.

  16. MR Diffusion Tensor Imaging Detects Rapid Microstructural Changes in Amygdala and Hippocampus Following Fear Conditioning in Mice

    Science.gov (United States)

    Ding, Abby Y.; Li, Qi; Zhou, Iris Y.; Ma, Samantha J.; Tong, Gehua; McAlonan, Grainne M.; Wu, Ed X.

    2013-01-01

    Background Following fear conditioning (FC), ex vivo evidence suggests that early dynamics of cellular and molecular plasticity in amygdala and hippocampal circuits mediate responses to fear. Such altered dynamics in fear circuits are thought to be etiologically related to anxiety disorders including posttraumatic stress disorder (PTSD). Consistent with this, neuroimaging studies of individuals with established PTSD in the months after trauma have revealed changes in brain regions responsible for processing fear. However, whether early changes in fear circuits can be captured in vivo is not known. Methods We hypothesized that in vivo magnetic resonance diffusion tensor imaging (DTI) would be sensitive to rapid microstructural changes elicited by FC in an experimental mouse PTSD model. We employed a repeated measures paired design to compare in vivo DTI measurements before, one hour after, and one day after FC-exposed mice (n = 18). Results Using voxel-wise repeated measures analysis, fractional anisotropy (FA) significantly increased then decreased in amygdala, decreased then increased in hippocampus, and was increasing in cingulum and adjacent gray matter one hour and one day post-FC respectively. These findings demonstrate that DTI is sensitive to early changes in brain microstructure following FC, and that FC elicits distinct, rapid in vivo responses in amygdala and hippocampus. Conclusions Our results indicate that DTI can detect rapid microstructural changes in brain regions known to mediate fear conditioning in vivo. DTI indices could be explored as a translational tool to capture potential early biological changes in individuals at risk for developing PTSD. PMID:23382811

  17. An Observational and Computational Variable Tagging System for Climate Change Informatics

    Science.gov (United States)

    Pouchard, L. C.; Lenhardt, W.; Branstetter, M. L.; Runciman, A.; Wang, D.; Kao, S.; King, A. W.; Climate Change Informatics Team

    2010-12-01

    As climate change science uses diverse data from observations and computational results to model and validate earth systems from global to local scale, understand complex processes, and perform integrated assessments, adaptable and accessible information systems that integrate these observations and model results are required. The data processing tasks associated with the simultaneous use of observation and modeling data are time-consuming because scientists are typically familiar with one or the other, but rarely both. Each data domain has its own portal, its own metadata formats, and its own query-building methods for obtaining datasets. The exact definition of variables and observational parameters may require substantial searches for unfamiliar topics. The dearth of formal descriptions such as ontologies compounds the problem and negatively impacts the advancement of science for each aspect of studying climate change. Our Observational and Computational Variable Tagging System aims to address these challenges through facilitating the quick identification of datasets of interest across archives by associating variables with tags or keywords from a controlled vocabulary. The prototype currently offers the ability to search by tags, variable names, and annotations. Names, plain text descriptions, units, dimensions, and a link to each dataset are returned. The information is aggregated from various locations at the source of origin. Keywords from NASA’s Global Change Master Directory provide built-in suggestions for tags. These features ensure accuracy and disambiguation. For the target application, the system tags variables and stores data from the Community Climate System Model (CCSM), International Boundary Water Commission, US Geological Survey, National Oceanic and Atmospheric Administration, and NASA. Our tagging system allows users to identify variable names and descriptions of observational and computational data from a single Web interface. Our system

  18. Adsorption properties of subtropical and tropical variable charge soils: Implications from climate change and biochar amendment

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ren-Kou; Qafoku, Nikolla; Van Ranst, Eric; Li, Jiu-yu; Jiang, Jun

    2016-01-25

    This review paper attempts to summarize the progress made in research efforts conducted over the last years to study the surface chemical properties of the tropical and subtropical soils, usually called variable charge soils, and the way they response to different management practices. The paper is composed of an introductory section that provides a brief discussion on the surface chemical properties of these soils, and five other review sections. The focus of these sections is on the evolution of surface chemical properties during the development of the variable charge properties (second section), interactions between oppositely charged particles and the resulting effects on the soil properties and especially on soil acidity (third section), the surface effects of low molecular weight organic acids sorbed to mineral surfaces and the chemical behavior of aluminum (fourth section), and the crop straw derived biochar induced changes of the surface chemical properties of these soils (fifth section). A discussion on the effect of climate change variables on the properties of the variable charge soils is included at the end of this review paper (sixth section).

  19. Soil Carbon Variability and Change Detection in the Forest Inventory Analysis Database of the United States

    Science.gov (United States)

    Wu, A. M.; Nater, E. A.; Dalzell, B. J.; Perry, C. H.

    2014-12-01

    The USDA Forest Service's Forest Inventory Analysis (FIA) program is a national effort assessing current forest resources to ensure sustainable management practices, to assist planning activities, and to report critical status and trends. For example, estimates of carbon stocks and stock change in FIA are reported as the official United States submission to the United Nations Framework Convention on Climate Change. While the main effort in FIA has been focused on aboveground biomass, soil is a critical component of this system. FIA sampled forest soils in the early 2000s and has remeasurement now underway. However, soil sampling is repeated on a 10-year interval (or longer), and it is uncertain what magnitude of changes in soil organic carbon (SOC) may be detectable with the current sampling protocol. We aim to identify the sensitivity and variability of SOC in the FIA database, and to determine the amount of SOC change that can be detected with the current sampling scheme. For this analysis, we attempt to answer the following questions: 1) What is the sensitivity (power) of SOC data in the current FIA database? 2) How does the minimum detectable change in forest SOC respond to changes in sampling intervals and/or sample point density? Soil samples in the FIA database represent 0-10 cm and 10-20 cm depth increments with a 10-year sampling interval. We are investigating the variability of SOC and its change over time for composite soil data in each FIA region (Pacific Northwest, Interior West, Northern, and Southern). To guide future sampling efforts, we are employing statistical power analysis to examine the minimum detectable change in SOC storage. We are also investigating the sensitivity of SOC storage changes under various scenarios of sample size and/or sample frequency. This research will inform the design of future FIA soil sampling schemes and improve the information available to international policy makers, university and industry partners, and the public.

  20. Biofuels, land use change, and greenhouse gas emissions: some unexplored variables.

    Science.gov (United States)

    Kim, Hyungtae; Kim, Seungdo; Dale, Bruce E

    2009-02-01

    Greenhouse gas release from land use change (the so-called "carbon debt") has been identified as a potentially significant contributor to the environmental profile of biofuels. The time required for biofuels to overcome this carbon debt due to land use change and begin providing cumulative greenhouse gas benefits is referred to as the "payback period" and has been estimated to be 100-1000 years depending on the specific ecosystem involved in the land use change event. Two mechanisms for land use change exist: "direct" land use change, in which the land use change occurs as part of a specific supply chain for a specific biofuel production facility, and "indirect" land use change, in which market forces act to produce land use change in land that is not part of a specific biofuel supply chain, including, for example, hypothetical land use change on another continent. Existing land use change studies did not consider many of the potentially important variables that might affect the greenhouse gas emissions of biofuels. We examine here several variables that have not yet been addressed in land use change studies. Our analysis shows that cropping management is a key factor in estimating greenhouse gas emissions associated with land use change. Sustainable cropping management practices (no-till and no-till plus cover crops) reduce the payback period to 3 years for the grassland conversion case and to 14 years for the forest conversion case. It is significant that no-till and cover crop practices also yield higher soil organic carbon (SOC) levels in corn fields derived from former grasslands or forests than the SOC levels that result if these grasslands or forests are allowed to continue undisturbed. The United States currently does not hold any of its domestic industries responsible for its greenhouse gas emissions. Thus the greenhouse gas standards established for renewable fuels such as corn ethanol in the Energy Independence and Security Act (EISA) of 2007 set a

  1. Variables influencing change leadership competencies to strategically manage transformation in the South African public sector

    OpenAIRE

    2013-01-01

    D.Litt. et Phil. (Public Management and Governance) This study focused on the variables that influence change leadership competencies to strategically manage transformation within the South African public sector. One of the key aims was to develop a competency framework for transformational leaders in senior public management positions. The thesis provided a conceptual description and explanation of appropriate and adequate leadership concepts, theories, approaches and phenomena that influ...

  2. The impact of climate change and variability on the generation of electrical power

    OpenAIRE

    Hagen Koch; Stefan Vögele; Fred F. Hattermann; Shaochun Huang

    2015-01-01

    Climate variability and change affect electricity generation in several ways. Electricity generation is directly dependent on climate/weather parameters like wind (wind power generation) or air temperature and resulting water temperature (thermal power plants). River discharge as a result of precipitation and temperature, the latter being one main factor influencing evapotranspiration, is important for hydro power generation and cooling of thermal power plants. In this study possible effects ...

  3. Assessment of climate change impacts on climate variables using probabilistic ensemble modeling and trend analysis

    Science.gov (United States)

    Safavi, Hamid R.; Sajjadi, Sayed Mahdi; Raghibi, Vahid

    2017-10-01

    Water resources in snow-dependent regions have undergone significant changes due to climate change. Snow measurements in these regions have revealed alarming declines in snowfall over the past few years. The Zayandeh-Rud River in central Iran chiefly depends on winter falls as snow for supplying water from wet regions in high Zagrous Mountains to the downstream, (semi-)arid, low-lying lands. In this study, the historical records (baseline: 1971-2000) of climate variables (temperature and precipitation) in the wet region were chosen to construct a probabilistic ensemble model using 15 GCMs in order to forecast future trends and changes while the Long Ashton Research Station Weather Generator (LARS-WG) was utilized to project climate variables under two A2 and B1 scenarios to a future period (2015-2044). Since future snow water equivalent (SWE) forecasts by GCMs were not available for the study area, an artificial neural network (ANN) was implemented to build a relationship between climate variables and snow water equivalent for the baseline period to estimate future snowfall amounts. As a last step, homogeneity and trend tests were performed to evaluate the robustness of the data series and changes were examined to detect past and future variations. Results indicate different characteristics of the climate variables at upstream stations. A shift is observed in the type of precipitation from snow to rain as well as in its quantities across the subregions. The key role in these shifts and the subsequent side effects such as water losses is played by temperature.

  4. Hydrological response to changing climate conditions: Spatial streamflow variability in the boreal region

    Science.gov (United States)

    Teutschbein, Claudia; Grabs, Thomas; Karlsen, Reinert H.; Laudon, Hjalmar; Bishop, Kevin

    2016-04-01

    It has long been recognized that streamflow-generating processes are not only dependent on climatic conditions, but also affected by physical catchment properties such as topography, geology, soils and land cover. We hypothesize that these landscape characteristics do not only lead to highly variable hydrologic behavior of rather similar catchments under the same stationary climate conditions (Karlsen et al., 2014), but that they also play a fundamental role for the sensitivity of a catchment to a changing climate (Teutschbein et al., 2015). A multi-model ensemble based on 15 regional climate models was combined with a multi-catchment approach to explore the hydrologic sensitivity of 14 partially nested and rather similar catchments in Northern Sweden to changing climate conditions and the importance of small-scale spatial variability. Current (1981-2010) and future (2061-2090) streamflow was simulated with the HBV model. As expected, projected increases in temperature and precipitation resulted in increased total available streamflow, with lower spring and summer flows, but substantially higher winter streamflow. Furthermore, significant changes in flow durations with lower chances of both high and low flows can be expected in boreal Sweden in the future. This overall trend in projected streamflow pattern changes was comparable among the analyzed catchments while the magnitude of change differed considerably. This suggests that catchments belonging to the same region can show distinctly different degrees of hydrological responses to the same external climate change signal. We reason that differences in spatially distributed physical catchment properties at smaller scales are not only of great importance for current streamflow behavior, but also play a major role as first-order control for the sensitivity of catchments to changing climate conditions. References Karlsen, R.H., T. Grabs, K. Bishop, H. Laudon, and J. Seibert (2014). Landscape controls on

  5. Water-borne Infections, Weather Variability and Climate Change in Eastern Russia

    Science.gov (United States)

    Tirrell, A.; Naumova, E. N.; Liss, A.

    2012-12-01

    For this project, a time-series analysis of existing data will be used to assess temporal and spatial associations between long-term, seasonal and short-term weather variability and water-borne infectious diseases in several Siberian municipalities. Building on these associations, we will generate estimates of future changes in infectious disease patterns based upon existing forecasts of climate change and likely increases in extreme weather events in Eastern Russia. Finally, we will contemplate the public health implications of these findings, and offer appropriate policy recommendations.

  6. Two centuries of observed atmospheric variability and change over the North Sea region

    Science.gov (United States)

    Stendel, Martin; van den Besselaar, Else; Hannachi, Abdel; Kent, Elizabeth; Lefebvre, Christiana; Rosenhagen, Gudrun; Schenk, Frederik; van der Schrier, Gerard; Woollings, Tim

    2016-04-01

    In the upcoming North Sea Region Climate Change Assessment (NOSCCA), we present a synthesis of current knowledge about past, present and possible future climate change in the North Sea region. A climate change assessment from published scientific work has been conducted as a kind of regional IPCC report, and a book has been produced that will be published by Springer in 2016. In the framework of the NOSCCA project, we examine past and present studies of variability and changes in atmospheric variables within the North Sea region over the instrumental period, roughly the past 200 years, based on observations and reanalyses. The variables addressed in this presentation are large-scale circulation, pressure and wind, surface air temperature, precipitation and radiative properties (clouds, solar radiation, and sunshine duration). While air temperature over land, not unexpectedly, has increased everywhere in the North Sea region, with strongest trends in spring and in the north of the region, a precipitation increase has been observed in the north and a decrease in the south of the region. This pattern goes along with a north-eastward shift of storm tracks and is in agreement with climate model projections under enhanced greenhouse gas concentrations. For other variables, it is not obvious which part of the observed changes may be due to anthropogenic activities and which is internally forced. It remains also unclear to what extent atmospheric circulation over the North Sea region is influenced by distant factors, in particular Arctic sea-ice decline in recent decades. There are indications of an increase in the number of deep cyclones (but not in the total number of cyclones), while storminess since the late 19th century shows no robust trends. The persistence of circulation types appears to have increased over the last century, and consequently, there is an indication for 'more extreme' extreme events. However, changes in extreme weather events are difficult to assess

  7. Protection changes the relevancy of scales of variability in coralligenous assemblages

    Science.gov (United States)

    Piazzi, L.; La Manna, G.; Cecchi, E.; Serena, F.; Ceccherelli, G.

    2016-06-01

    The knowledge of natural spatial patterns of variability is crucial to discriminate between natural changes and human-induced effects and to plan monitoring programs and impact evaluation studies. The present study aimed at estimating the spatial variability of coralligenous habitat, one of the main important habitats of the Mediterranean Sea, at several spatial scales. Specifically, the following hypotheses were tested: i) the structure of coralligenous assemblage and ii) the abundance of main taxa/groups both changed among different spatial scales differently depending on protection. A hierarchical sampling design was used to study 14 localities (7 Marine Protected Areas and 7 unprotected) at multiple spatial scales through photographic recording. The study suggested that, in protected conditions, the structure of coralligenous assemblages mostly varied at small spatial scale (m apart), while the structure is similar across different localities, sites and areas, even if the abundance of the main taxa/morphological groups changed. In unprotected conditions, variability among localities was higher than among Marine Protected Areas, while an opposite trend was observed at the smaller spatial scales.

  8. The Indian monsoon variability and civilization changes in the Indian subcontinent.

    Science.gov (United States)

    Kathayat, Gayatri; Cheng, Hai; Sinha, Ashish; Yi, Liang; Li, Xianglei; Zhang, Haiwei; Li, Hangying; Ning, Youfeng; Edwards, R Lawrence

    2017-12-01

    The vast Indo-Gangetic Plain in South Asia has been home to some of the world's oldest civilizations, whose fortunes ebbed and flowed with time-plausibly driven in part by shifts in the spatiotemporal patterns of the Indian summer monsoon rainfall. We use speleothem oxygen isotope records from North India to reconstruct the monsoon's variability on socially relevant time scales, allowing us to examine the history of civilization changes in the context of varying hydroclimatic conditions over the past 5700 years. Our data suggest that significant shifts in monsoon rainfall have occurred in concert with changes in the Northern Hemisphere temperatures and the discharges of the Himalayan rivers. The close temporal relationship between these large-scale hydroclimatic changes and the intervals marking the significant sociopolitical developments of the Indus Valley and Vedic civilizations suggests a plausible role of climate change in shaping the important chapters of the history of human civilization in the Indian subcontinent.

  9. Climate change or variable weather: Rethinking Danish homeowners' perceptions of floods and climate

    DEFF Research Database (Denmark)

    Baron, Nina; Petersen, Lars Kjerulf

    2015-01-01

    Climate scenarios predict that an effect of climate change will be more areas at risk of extensive flooding. This article builds on a qualitative case study of homeowners in the flood-prone area of Lolland in Denmark and uses the theories of Tim Ingold and Bruno Latour to rethink the way we...... understand homeowners’ perception of climate change and local flood risk. Ingold argues that those perceptions are shaped by people’s experiences with and connections to their local landscape. People experience the local variability of the weather, and not global climate change as presented in statistical...... prevent the residents in Lolland from experiencing many of the changes that are already occurring and, at the same time, give them a feeling of being able to control the water to the extent that it is prevented from flooding their homes, both now and in the future. The combination of these two theoretical...

  10. Streamflow variability response to climate change and cascade dams development in a coastal China watershed

    Science.gov (United States)

    Zhang, Zhenyu; Huang, Jinliang; Huang, Yaling; Hong, Huasheng

    2015-12-01

    Coastal watersheds and their changes in streamflow have become a particular concern in hydrology and water resource management. The ecohydrologic analysis and environmental flow component were coupled in this study to assess the streamflow variability response to climate change and human activities in the Jiulong River Watershed (JRW). Results showed that human activities were the main contributing factors to decreasing streamflow in the JRW. Available water resources decreased by 4.34% and 3.17% in the North River and West River, respectively. In addition to climate change, watershed characteristics partly influenced the streamflow quantity and regime in the North River and West River. The cascade dam construction along the mainstream of the JRW, which made the water bodies from free-flowing rivers to cascade lakes, altered the patterns of streamflow regime in terms of low and high flow events, as well as the flood pattern. The monthly low flow increased in almost all seasons; the high flow pulses homogenized; and little variation in the flood pattern was detected within the JRW. We present a case study in a southeast coastal watershed to illustrate a combined approach that could facilitate to evaluate the streamflow variability in terms of streamflow quantity and regime response to climate change and cascade dams development in two adjacent rivers within the JRW, which could hopefully provide water managers on the strategies to fight the effect of environmental changes on watershed ecosystem.

  11. Kepler Observations of Rapid Optical Variability in the BL Lac Object W2r192+42

    Science.gov (United States)

    R.Edelson; Mushotzky, R.; Vaughn, S.; Scargle, J.; Gandhi, P.; Malkan, M.; Baumgartner, W.

    2013-01-01

    We present the first Kepler monitoring of a strongly variable BL Lac, W2R1926+42. The light curve covers 181 days with approx. 0.2% errors, 30 minute sampling and >90% duty cycle, showing numerous delta-I/I > 25% flares over timescales as short as a day. The flux distribution is highly skewed and non-Gaussian. The variability shows a strong rms-flux correlation with the clearest evidence to date for non-linearity in this relation. We introduce a method to measure periodograms from the discrete autocorrelation function, an approach that may be well-suited to a wide range of Kepler data. The periodogram is not consistent with a simple power-law, but shows a flattening at frequencies below 7x10(exp -5) Hz. Simple models of the power spectrum, such as a broken power law, do not produce acceptable fits, indicating that the Kepler blazar light curve requires more sophisticated mathematical and physical descriptions than currently in use.

  12. Human Health Impacts of and Public Health Adaptation to Climate Variability and Change

    Science.gov (United States)

    Ebi, K. L.

    2007-12-01

    Weather and climate are among the factors that determine the geographic range and incidence of several major causes of ill health, including undernutrition, diarrheal diseases and other conditions due to unsafe water and lack of basic sanitation, and malaria. The Human Health chapter in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change concluded that climate change has begun to negatively affect human health, and that projected climate change will increase the risks of climate-sensitive health outcomes, particularly in lower-income populations, predominantly within tropical/subtropical countries. Those at greatest risk include the urban poor, older adults, children, traditional societies, subsistence farmers, and coastal populations, particularly in low income countries. The cause-and-effect chain from climate change to changing patterns of health determinants and outcomes is complex and includes socioeconomic, institutional, and other factors. The severity of future impacts will be determined by changes in climate as well as by concurrent changes in nonclimatic factors and by the adaptation measures implemented to reduce negative impacts. Public health has a long history of effectively intervening to reduce risks to the health of individuals and communities. Lessons learned from more than 150 years of research and intervention can provide insights to guide the design and implementation of effective and efficient interventions to reduce the current and projected impacts of climate variability and change.

  13. Sensitivity of water resources in the Delaware River basin to climate variability and change

    Science.gov (United States)

    Ayers, Mark A.; Wolock, David M.; McCabe, Gregory J.; Hay, Lauren E.; Tasker, Gary D.

    1994-01-01

    Because of the greenhouse effect, projected increases in atmospheric carbon dioxide levels might cause global warming, which in turn could result in changes in precipitation patterns and evapotranspiration and in increases in sea level. This report describes the greenhouse effect; discusses the problems and uncertainties associated with the detection, prediction, and effects of climate change; and presents the results of sensitivity analyses of how climate change might affect water resources in the Delaware River basin. Sensitivity analyses suggest that potentially serious shortfalls of certain water resources in the basin could result if some scenarios for climate change come true . The results of model simulations of the basin streamflow demonstrate the difficulty in distinguishing the effects that climate change versus natural climate variability have on streamflow and water supply . The future direction of basin changes in most water resources, furthermore, cannot be precisely determined because of uncertainty in current projections of regional temperature and precipitation . This large uncertainty indicates that, for resource planning, information defining the sensitivities of water resources to a range of climate change is most relevant . The sensitivity analyses could be useful in developing contingency plans for evaluating and responding to changes, should they occur.

  14. Rapid decision support tool based on novel ecosystem service variables for retrofitting of permeable pavement systems in the presence of trees.

    Science.gov (United States)

    Scholz, Miklas; Uzomah, Vincent C

    2013-08-01

    The retrofitting of sustainable drainage systems (SuDS) such as permeable pavements is currently undertaken ad hoc using expert experience supported by minimal guidance based predominantly on hard engineering variables. There is a lack of practical decision support tools useful for a rapid assessment of the potential of ecosystem services when retrofitting permeable pavements in urban areas that either feature existing trees or should be planted with trees in the near future. Thus the aim of this paper is to develop an innovative rapid decision support tool based on novel ecosystem service variables for retrofitting of permeable pavement systems close to trees. This unique tool proposes the retrofitting of permeable pavements that obtained the highest ecosystem service score for a specific urban site enhanced by the presence of trees. This approach is based on a novel ecosystem service philosophy adapted to permeable pavements rather than on traditional engineering judgement associated with variables based on quick community and environment assessments. For an example case study area such as Greater Manchester, which was dominated by Sycamore and Common Lime, a comparison with the traditional approach of determining community and environment variables indicates that permeable pavements are generally a preferred SuDS option. Permeable pavements combined with urban trees received relatively high scores, because of their great potential impact in terms of water and air quality improvement, and flood control, respectively. The outcomes of this paper are likely to lead to more combined permeable pavement and tree systems in the urban landscape, which are beneficial for humans and the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Smallholder agriculture in India and adaptation to current and future climate variability and climate change

    Science.gov (United States)

    Murari, K. K.; Jayaraman, T.

    2014-12-01

    Modeling studies have indicated that global warming, in many regions, will increase the exposure of major crops to rainfall and temperature stress, leading to lower crop yields. Climate variability alone has a potential to decrease yield to an extent comparable to or greater than yield reductions expected due to rising temperature. For India, where agriculture is important, both in terms of food security as well as a source of livelihoods to a majority of its population, climate variability and climate change are subjects of serious concern. There is however a need to distinguish the impact of current climate variability and climate change on Indian agriculture, especially in relation to their socioeconomic impact. This differentiation is difficult to determine due to the secular trend of increasing production and yield of the past several decades. The current research in this aspect is in an initial stage and requires a multi-disciplinary effort. In this study, we assess the potential differential impacts of environmental stress and shock across different socioeconomic strata of the rural population, using village level survey data. The survey data from eight selected villages, based on the Project on Agrarian Relations in India conducted by the Foundation for Agrarian Studies, indicated that income from crop production of the top 20 households (based on the extent of operational land holding, employment of hired labour and asset holdings) is a multiple of the mean income of the village. In sharp contrast, the income of the bottom 20 households is a fraction of the mean and sometimes negative, indicating a net loss from crop production. The considerable differentials in output and incomes suggest that small and marginal farmers are far more susceptible to climate variability and climate change than the other sections. Climate change is effectively an immediate threat to small and marginal farmers, which is driven essentially by socioeconomic conditions. The impact

  16. MINUTE-SCALE RAPID VARIABILITY OF THE OPTICAL POLARIZATION IN THE NARROW-LINE SEYFERT 1 GALAXY PMN J0948+0022

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Ryosuke; Tanaka, Yasuyuki T.; Fukazawa, Yasushi; Kawaguchi, Kenji; Takaki, Katsutoshi; Ueno, Issei [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kawabata, Koji S.; Moritani, Yuki; Uemura, Makoto; Akitaya, Hiroshi; Yoshida, Michitoshi; Ohsugi, Takashi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hanayama, Hidekazu; Miyaji, Takeshi [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, 1024-1 Arakawa, Ishigaki, Okinawa 907-0024 (Japan); Kawai, Nobuyuki, E-mail: itoh@hep01.hepl.hiroshima-u.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2013-09-20

    We report on optical photopolarimetric results of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy PMN J0948+0022 on 2012 December to 2013 February triggered by flux enhancements in the near infrared and γ-ray bands. With the one-shot polarimetry of the Hiroshima One-shot Wide field Polarimeter installed on the Kanata Telescope, we detected very rapid variability in the polarized-flux (PF) light curve on MJD 56281 (2012 December 20). The rise and decay times were about 140 s and 180 s, respectively. The polarization degree (PD) reached 36% ± 3% at the peak of the short-duration pulse, while the polarization angle remained almost constant. In addition, temporal profiles of the total flux and PD showed highly variable but well correlated behavior and discrete correlation function analysis revealed that no significant time lag of more than 10 minutes was present. The high PD and minute-scale variability in PF provides clear evidence of synchrotron radiation from a very compact emission region of ∼10{sup 14} cm size with a highly ordered magnetic field. Such micro-variability of polarization is also observed in several blazar jets, but its complex relation between total flux and PD are explained by a multi-zone model in several blazars. The implied single emission region in PMN J0948+0022 might reflect a difference of jets between RL-NLSy1s and blazars.

  17. Climate change and climate variability: personal motivation for adaptation and mitigation.

    Science.gov (United States)

    Semenza, Jan C; Ploubidis, George B; George, Linda A

    2011-05-21

    Global climate change impacts on human and natural systems are predicted to be severe, far reaching, and to affect the most physically and economically vulnerable disproportionately. Society can respond to these threats through two strategies: mitigation and adaptation. Industry, commerce, and government play indispensable roles in these actions but so do individuals, if they are receptive to behavior change. We explored whether the health frame can be used as a context to motivate behavioral reductions of greenhouse gas emissions and adaptation measures. In 2008, we conducted a cross-sectional survey in the United States using random digit dialing. Personal relevance of climate change from health threats was explored with the Health Belief Model (HBM) as a conceptual frame and analyzed through logistic regressions and path analysis. Of 771 individuals surveyed, 81% (n = 622) acknowledged that climate change was occurring, and were aware of the associated ecologic and human health risks. Respondents reported reduced energy consumption if they believed climate change could affect their way of life (perceived susceptibility), Odds Ratio (OR) = 2.4 (95% Confidence Interval (CI): 1.4-4.0), endanger their life (perceived severity), OR = 1.9 (95% CI: 1.1-3.1), or saw serious barriers to protecting themselves from climate change, OR = 2.1 (95% CI: 1.2-3.5). Perceived susceptibility had the strongest effect on reduced energy consumption, either directly or indirectly via perceived severity. Those that reported having the necessary information to prepare for climate change impacts were more likely to have an emergency kit OR = 2.1 (95% CI: 1.4-3.1) or plan, OR = 2.2 (95% CI: 1.5-3.2) for their household, but also saw serious barriers to protecting themselves from climate change or climate variability, either by having an emergency kit OR = 1.6 (95% CI: 1.1-2.4) or an emergency plan OR = 1.5 (95%CI: 1.0-2.2). Motivation for voluntary mitigation is mostly dependent on

  18. Climate change and climate variability: personal motivation for adaptation and mitigation

    Directory of Open Access Journals (Sweden)

    Ploubidis George B

    2011-05-01

    Full Text Available Abstract Background Global climate change impacts on human and natural systems are predicted to be severe, far reaching, and to affect the most physically and economically vulnerable disproportionately. Society can respond to these threats through two strategies: mitigation and adaptation. Industry, commerce, and government play indispensable roles in these actions but so do individuals, if they are receptive to behavior change. We explored whether the health frame can be used as a context to motivate behavioral reductions of greenhouse gas emissions and adaptation measures. Methods In 2008, we conducted a cross-sectional survey in the United States using random digit dialing. Personal relevance of climate change from health threats was explored with the Health Belief Model (HBM as a conceptual frame and analyzed through logistic regressions and path analysis. Results Of 771 individuals surveyed, 81% (n = 622 acknowledged that climate change was occurring, and were aware of the associated ecologic and human health risks. Respondents reported reduced energy consumption if they believed climate change could affect their way of life (perceived susceptibility, Odds Ratio (OR = 2.4 (95% Confidence Interval (CI: 1.4 - 4.0, endanger their life (perceived severity, OR = 1.9 (95% CI: 1.1 - 3.1, or saw serious barriers to protecting themselves from climate change, OR = 2.1 (95% CI: 1.2 - 3.5. Perceived susceptibility had the strongest effect on reduced energy consumption, either directly or indirectly via perceived severity. Those that reported having the necessary information to prepare for climate change impacts were more likely to have an emergency kit OR = 2.1 (95% CI: 1.4 - 3.1 or plan, OR = 2.2 (95% CI: 1.5 -3.2 for their household, but also saw serious barriers to protecting themselves from climate change or climate variability, either by having an emergency kit OR = 1.6 (95% CI: 1.1 - 2.4 or an emergency plan OR = 1.5 (95%CI: 1.0 - 2

  19. Rapid land cover map updates using change detection and robust random forest classifiers

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2016-01-01

    Full Text Available The paper evaluated the Landsat Automated Land Cover Update Mapping (LALCUM) system designed to rapidly update a land cover map to a desired nominal year using a pre-existing reference land cover map. The system uses the Iteratively Reweighted...

  20. Tropical rodents change rapidly germinating seeds into long-term food supplies

    NARCIS (Netherlands)

    Jansen, P.A.; Bongers, F.J.J.M.; Prins, H.H.T.

    2006-01-01

    Seed-hoarding vertebrates may survive yearly periods of food scarcity by storing seeds during the preceding fruiting season. It is poorly understood why rodents creating long-term reserves, especially those in the tropics, incorporate seeds from plant species that germinate rapidly and hence seem

  1. The impact of climate change and variability on the generation of electrical power

    Directory of Open Access Journals (Sweden)

    Hagen Koch

    2015-04-01

    Full Text Available Climate variability and change affect electricity generation in several ways. Electricity generation is directly dependent on climate/weather parameters like wind (wind power generation or air temperature and resulting water temperature (thermal power plants. River discharge as a result of precipitation and temperature, the latter being one main factor influencing evapotranspiration, is important for hydro power generation and cooling of thermal power plants. In this study possible effects of climate variability and change on electricity generation in Germany are analyzed. Considered is electricity generation by thermal power plants, wind power plants and hydro power plants. While hydro power plants and thermal power plants are affected negatively due to declining river discharge or higher water temperatures, for wind power generation no clear tendency was found. The reduction for hydro power generation could be leveled out by a slight increase in installed capacity and modernization of turbines and generators. By a replacement of old once-through cooling systems by closed-circuit cooling systems for new thermal power plants the negative impacts on electricity generation can be reduced significantly. The planned increase of installed capacity for wind power generation clearly surpasses the changes arising from climate change.

  2. Spatial contexts for temporal variability in alpine vegetation under ongoing climate change

    Science.gov (United States)

    Fagre, Daniel B.; ,; George P. Malanson,

    2013-01-01

    A framework to monitor mountain summit vegetation (The Global Observation Research Initiative in Alpine Environments, GLORIA) was initiated in 1997. GLORIA results should be taken within a regional context of the spatial variability of alpine tundra. Changes observed at GLORIA sites in Glacier National Park, Montana, USA are quantified within the context of the range of variability observed in alpine tundra across much of western North America. Dissimilarity is calculated and used in nonmetric multidimensional scaling for repeated measures of vascular species cover at 14 GLORIA sites with 525 nearby sites and with 436 sites in western North America. The lengths of the trajectories of the GLORIA sites in ordination space are compared to the dimensions of the space created by the larger datasets. The absolute amount of change on the GLORIA summits over 5 years is high, but the degree of change is small relative to the geographical context. The GLORIA sites are on the margin of the ordination volumes with the large datasets. The GLORIA summit vegetation appears to be specialized, arguing for the intrinsic value of early observed change in limited niche space.

  3. Remote sensing of climate changes effects on urban green biophysical variables

    Science.gov (United States)

    Zoran, Maria A.; Dida, Adrian I.

    2016-10-01

    Urban vegetation land cover change is a direct measure of quantitative increase or decrease in sources of urban pollution and the dimension of extreme climate events and changes that determine environment quality. This study addresses climate changes effects and anthropogenic impacts on urban green biophysical variables based on time series satellite data in synergy with in-situ data and new analytical methods. This paper explored the use of time-series MODIS Terra/Aqua Normalized Difference Vegetation Index (NDVI/EVI), Land Surface Temperature (LST) and Leaf Area Index (LAI), land surface albedo data to provide vegetation change detection information for Bucharest test area during 2000- 2015 period. Training and validation are based on a reference dataset collected from Landsat ETM remote sensing data. The mean detection accuracy for investigated period was 89%, with a reasonable balance between change commission errors (19.74%), change omission errors (24.72%), and Kappa coefficient of 0.74. Annual change detection rates across the urban/peri-urban green areas over the study period were estimated at 0.77% per annum in the range of 0.45% (2000) to 0.78% (2015).Vegetation dynamics in urban areas at seasonal and longer timescales reflect large-scale interactions between the terrestrial biosphere and the climate system.

  4. Quantifying changes and their uncertainties in probability distribution of climate variables using robust statistics

    Energy Technology Data Exchange (ETDEWEB)

    Hannachi, A. [University of Reading, Department of Meteorology, Earley Gate, PO Box 243, Reading (United Kingdom)

    2006-08-15

    Robust tools are presented in this manuscript to assess changes in probability density function (pdf) of climate variables. The approach is based on order statistics and aims at computing, along with their standard errors, changes in various quantiles and related statistics. The technique, which is nonparametric and simple to compute, is developed for both independent and dependent data. For autocorrelated data, serial correlation is addressed via Monte Carlo simulations using various autoregressive models. The ratio between the average standard errors, over several quantiles, of quantile estimates for correlated and independent data, is then computed. A simple scaling-law type relationship is found to hold between this ratio and the lag-1 autocorrelation. The approach has been applied to winter monthly Central England Temperature (CET) and North Atlantic Oscillation (NAO) time series from 1659 to 1999 to assess/quantify changes in various parameters of their pdf. For the CET, significant changes in median (or scale) and also in low and high quantiles are observed between various time slices, in particular between the pre- and post-industrial revolution. Observed changes in spread and also quartile skewness of the pdf, however, are not statistically significant (at 95% confidence level). For the NAO index we find mainly large significant changes in variance (or scale), yielding significant changes in low/high quantiles. Finally, the performance of the method compared to few conventional approaches is discussed. (orig.)

  5. Assessing surface albedo change and its induced radiation budget under rapid urbanization with Landsat and GLASS data

    Science.gov (United States)

    Hu, Yonghong; Jia, Gensuo; Pohl, Christine; Zhang, Xiaoxuan; van Genderen, John

    2016-02-01

    Radiative forcing (RF) induced by land use (mainly surface albedo) change is still not well understood in climate change science, especially the effects of changes in urban albedo due to rapid urbanization on the urban radiation budget. In this study, a modified RF derivation approach based on Landsat images was used to quantify changes in the solar radiation budget induced by variations in surface albedo in Beijing from 2001 to 2009. Field radiation records from a Beijing meteorological station were used to identify changes in RF at the local level. There has been rapid urban expansion over the last decade, with the urban land area increasing at about 3.3 % annually from 2001 to 2009. This has modified three-dimensional urban surface properties, resulting in lower albedo due to complex building configurations of urban centers and higher albedo on flat surfaces of suburban areas and cropland. There was greater solar radiation (6.93 × 108 W) in the urban center in 2009 than in 2001. However, large cropland and urban fringe areas caused less solar radiation absorption. RF increased with distance from the urban center (less than 14 km) and with greater urbanization, with the greatest value being 0.41 W/m2. The solar radiation budget in urban areas was believed to be mainly influenced by urban structural changes in the horizontal and vertical directions. Overall, the results presented herein indicate that cumulative urbanization impacts on the natural radiation budget could evolve into an important driver of local climate change.

  6. Vulnerability and Tradeoffs of Dairy Farmers to the Impacts of Climate Variability and Change in India

    Science.gov (United States)

    Radhakrishnan, A.; Gupta, J.; R, D.

    2016-12-01

    In recent years climate variability has threatened the sustainability of dairy animals and dairy farming in India. The study aims at assessing the vulnerability and tradeoffs of Dairy Based Livelihoods to Climate Variability and Change in the Western Ghat ecosystem and for this purpose; data were aggregated to an overall Livelihood Vulnerability Index (LVI) to Climate Change underlying the principles of IPCC, using 28 indicators and trade-off between vulnerability and milk production was calculated. Data were collected through Participatory Rural Appraisal and personal interviews from 360 randomly selected dairy farmers of three states of Western Ghat region, complemented by thirty years of gridded weather data and livestock data. The index score of dairy based livelihoods of many regions were negative. Lanja taluka of Maharashtra has highest level of vulnerability with overall LVI value -4.17 with 48% farmers falling in highly vulnerable category. There is also significant tradeoff between milk production and components of LVI. Thus our research will provide an important basis for policy makers to develop appropriate adaptation strategies for alarming situation and decision making for farmers to minimize the risk of dairy sector to climate variability.

  7. On the watershed response to land use/cover change and climate variability in the Prairies

    Science.gov (United States)

    Ehsanzadeh, E.; van der Kamp, G.; Spence, C.

    2012-04-01

    Land use change for agriculture purposes or due to urbanization may change the movement patterns and also sources of water within a watershed boundary. It is of key interest to know how the integrated impact of these disturbances, along with a regime change due to natural climate variability or human induced climate change, affects runoff response behavior of a watershed. This study investigates changes in runoff production behavior of over 50 small to very large watersheds with drainage areas ranging from 35 to 160000 km2 in the North American Prairies. These depression-dominated watersheds which are characterized with strong memory properties have been subjected to diverse human disturbances. Our statistical analysis shows that there has been a range of diverse change in seasonal regimes of runoff as well as changes in snowfall versus rainfall patterns over the study area. This study shows that in watersheds with recorded history of disturbances the impact of human interference, along with modifications to climate inputs, on runoff response behavior is nonlinear, complex, and diverse. The results of this study suggest that different disturbances (i.e. removal of vegetation, changes in texture and structure of the soil through tilling or grading, ditching, construction of dams, etc.) may have varying or even opposite impacts on the residence time of water on the ground and in bodies of surface water such as streams or wetlands within the watershed boundaries. It seems that a change in watershed response behavior is a function of interaction among these diverse land use/cover changes as well as modifications to climate inputs. This complex response results in varying nonstationarity behaviors depending on the extent of each modification and also spatial scale of the watershed under study.

  8. Patterns of change in high frequency precipitation variability over North America.

    Science.gov (United States)

    Roque-Malo, Susana; Kumar, Praveen

    2017-09-18

    Precipitation variability encompasses attributes associated with the sequencing and duration of events of the full range of magnitudes. However, climate change studies have largely focused on extreme events. Using analyses of long-term weather station data, we show that high frequency events, such as fraction of wet days in a year and average duration of wet and dry periods, are undergoing significant changes across North America. Further, these changes are more prevalent and larger than those associated with extremes. Such trends also exist for events of a range of magnitudes. Existence of localized clusters with opposing trend to that of broader geographic variation illustrates the role of microclimate and other drivers of trends. Such hitherto unknown patterns over the entire North American continent have the potential to significantly inform our characterization of the resilience and vulnerability of a broad range of ecosystems and agricultural and socio-economic systems. They can also set new benchmarks for climate model assessments.

  9. A replicated climate change field experiment reveals rapid evolutionary response in an ecologically important soil invertebrate

    DEFF Research Database (Denmark)

    Bataillon, Thomas; Galtier, Nicolas; Bernard, Aurelien

    2016-01-01

    associated to changes in soil temperature and soil moisture. This shows an evolutionaryresponse to realistic climate change happening over short-time scale, and calls for incorporating evolution into modelspredicting future response of species to climate change. It also shows that designed climate change...... experiments coupled with genome sequencing offer great potential to test for the occurrence (or lack) of an evolutionary response.......Whether species can respond evolutionarily to current climate change is crucial for the persistence of many species. Yet, very few studies have examined genetic responses to climate change in manipulated experiments carried out innatural field conditions. We examined the evolutionary response...

  10. Flexible stocking as a strategy for enhancing ranch profitability in the face of a changing and variable climate

    Science.gov (United States)

    Predicted climate change impacts include increased weather variability and increased occurrences of extreme events such as drought. Such climate changes potentially affect cattle performance as well as pasture and range productivity. These climate induced risks are often coupled with variable market...

  11. Changes in fractal structure of heart rate variability during a nap in one case.

    Science.gov (United States)

    Shono, H; Shono, M; Takasaki, M; Iwasaka, T; Sugimori, H

    2001-06-01

    The objective of the present study was to analyze fractal structures of adult heart rate (HR) variability during a nap. Fractal analysis was carried out in one case over consecutive 10-min time series of HR, which were simultaneously recorded with electroencephalogram. Scaling relationships showed cross-over patterns characterized by alphas and alphal (i.e. slopes above and below a cross-over point). The alphas and alphal were black and white noise at Stage 4 of NREM sleep, and black and 1/f noise in REM sleep. Cross-over points changed from the first to second sleep cycle. We demonstrate the multifractal structures of HR variability during a nap in the present case.

  12. Systemic range shift lags among a pollinator species assemblage following rapid climate change

    DEFF Research Database (Denmark)

    Bedford, Felicity E.; Whittaker, Robert J.; Kerr, Jeremy T.

    2012-01-01

    Contemporary climate change is driving widespread geographical range shifts among many species. If species are tracking changing climate successfully, then leading populations should experience similar climatic conditions through time as new populations establish beyond historical range margins. ...

  13. Impacts of climate variability and future climate change on harmful algal blooms and human health

    Science.gov (United States)

    Moore, Stephanie K; Trainer, Vera L; Mantua, Nathan J; Parker, Micaela S; Laws, Edward A; Backer, Lorraine C; Fleming, Lora E

    2008-01-01

    Anthropogenically-derived increases in atmospheric greenhouse gas concentrations have been implicated in recent climate change, and are projected to substantially impact the climate on a global scale in the future. For marine and freshwater systems, increasing concentrations of greenhouse gases are expected to increase surface temperatures, lower pH, and cause changes to vertical mixing, upwelling, precipitation, and evaporation patterns. The potential consequences of these changes for harmful algal blooms (HABs) have received relatively little attention and are not well understood. Given the apparent increase in HABs around the world and the potential for greater problems as a result of climate change and ocean acidification, substantial research is needed to evaluate the direct and indirect associations between HABs, climate change, ocean acidification, and human health. This research will require a multidisciplinary approach utilizing expertise in climatology, oceanography, biology, epidemiology, and other disciplines. We review the interactions between selected patterns of large-scale climate variability and climate change, oceanic conditions, and harmful algae. PMID:19025675

  14. Rapid transformation of two libraries using Kotter?s Eight Steps of Change

    OpenAIRE

    Wheeler, Terrie R.; Holmes, Kristi L.

    2017-01-01

    Background Two new directors were each charged by their institutions to catalyze transformational change in their libraries and to develop dynamic and evolving information ecosystems ready for the information challenges of the future. The directors approached this transformational change using a strategic, forward-looking approach. Results This paper presents examples of actions that served as catalysts for change at the two libraries using Kotter?s Eight Steps of Change as a framework. Small...

  15. Systemic range shift lags among a pollinator species assemblage following rapid climate change

    DEFF Research Database (Denmark)

    Bedford, Felicity E.; Whittaker, Robert J.; Kerr, Jeremy T.

    2012-01-01

    Contemporary climate change is driving widespread geographical range shifts among many species. If species are tracking changing climate successfully, then leading populations should experience similar climatic conditions through time as new populations establish beyond historical range margins. ...... species assemblage in responses to recent climate change. Even among the most mobile species and without anthropogenic barriers to dispersal, these pollinators have been unable to extend their ranges as fast as required to keep pace with climate change....

  16. Plant trait diversity buffers variability in denitrification potential over changes in season and soil conditions.

    Directory of Open Access Journals (Sweden)

    Bonnie M McGill

    Full Text Available BACKGROUND: Denitrification is an important ecosystem service that removes nitrogen (N from N-polluted watersheds, buffering soil, stream, and river water quality from excess N by returning N to the atmosphere before it reaches lakes or oceans and leads to eutrophication. The denitrification enzyme activity (DEA assay is widely used for measuring denitrification potential. Because DEA is a function of enzyme levels in soils, most ecologists studying denitrification have assumed that DEA is less sensitive to ambient levels of nitrate (NO(3(- and soil carbon and thus, less variable over time than field measurements. In addition, plant diversity has been shown to have strong effects on microbial communities and belowground processes and could potentially alter the functional capacity of denitrifiers. Here, we examined three questions: (1 Does DEA vary through the growing season? (2 If so, can we predict DEA variability with environmental variables? (3 Does plant functional diversity affect DEA variability? METHODOLOGY/PRINCIPAL FINDINGS: The study site is a restored wetland in North Carolina, US with native wetland herbs planted in monocultures or mixes of four or eight species. We found that denitrification potentials for soils collected in July 2006 were significantly greater than for soils collected in May and late August 2006 (p<0.0001. Similarly, microbial biomass standardized DEA rates were significantly greater in July than May and August (p<0.0001. Of the soil variables measured--soil moisture, organic matter, total inorganic nitrogen, and microbial biomass--none consistently explained the pattern observed in DEA through time. There was no significant relationship between DEA and plant species richness or functional diversity. However, the seasonal variance in microbial biomass standardized DEA rates was significantly inversely related to plant species functional diversity (p<0.01. CONCLUSIONS/SIGNIFICANCE: These findings suggest that

  17. Molar changes with cervical headgear alone or in combination with rapid maxillary expansion.

    Science.gov (United States)

    Marchiori Farret, Marcel; de Lima, Eduardo Martinelli S; Pereira Araújo, Vanessa; Deon Rizzatto, Susana Maria; Macedo de Menezes, Luciane; Lima Grossi, Marcio

    2008-09-01

    To test the hypothesis that there is no difference in the distal movement of the maxillary first permanent molars when cervical headgear is used alone or in combination with rapid maxillary expansion. The sample was composed of 36 subjects (aged 9 to 13 years), treated in the Faculty of Dentistry, Pontifícia Universidade Cat;aaolica, Rio Grande do Sul, Brazil. The individuals were in good health and in their pubertal growth period. All had Class II division 1 malocclusion. The patients were divided into two groups: group 1 (22 subjects), Class II, with a normal transverse maxilla treated with cervical traction headgear (HG) 400 g 12 h/d, and group 2 (14 subjects), Class II maxillary transverse deficiency treated with rapid maxillary expansion plus cervical traction headgear (RME + HG). An additional group 3 (17 subjects) served as a control group and included individuals with the same characteristics. All subjects had two lateral cephalograms: initial (T1) and progress (T2), taken 6 months later. Differences between T1 and T2 were compared with the Student's t-test, and three groups were compared by the analysis of variance and Tukey multiple comparison test. Results showed greater distal tipping and greater distal movement of the first permanent molars in group 1 (HG) than in group 2 (RME + HG), P .05). The hypothesis was rejected. Cervical traction headgear alone produced greater distal movement effects in maxillary first permanent molars when compared with rapid maxillary expansion associated with cervical headgear.

  18. Seasonal variability of rocky reef fish assemblages: Detecting functional and structural changes due to fishing effects

    Science.gov (United States)

    Henriques, Sofia; Pais, Miguel Pessanha; Costa, Maria José; Cabral, Henrique Nogueira

    2013-05-01

    The present study analyzed the effects of seasonal variation on the stability of fish-based metrics and their capability to detect changes in fish assemblages, which is yet poorly understood despite the general idea that guilds are more resilient to natural variability than species abundances. Three zones subject to different levels of fishing pressure inside the Arrábida Marine Protected Area (MPA) were sampled seasonally. The results showed differences between warm (summer and autumn) and cold (winter and spring) seasons, with the autumn clearly standing out. In general, the values of the metrics density of juveniles, density of invertebrate feeders and density of omnivores increased in warm seasons, which can be attributed to differences in recruitment patterns, spawning migrations and feeding activity among seasons. The density of generalist/opportunistic individuals was sensitive to the effect of fishing, with higher values at zones with the lowest level of protection, while the density of individuals with high commercial value only responded to fishing in the autumn, due to a cumulative result of both juveniles and adults abundances during this season. Overall, this study showed that seasonal variability affects structural and functional features of the fish assemblage and that might influence the detection of changes as a result of anthropogenic pressures. The choice of a specific season, during warm sea conditions after the spawning period (July-October), seems to be more adequate to assess changes on rocky-reef fish assemblages.

  19. Evaluating Successful Livelihood Adaptation to Climate Variability and Change in Southern Africa

    Directory of Open Access Journals (Sweden)

    Henny Osbahr

    2010-06-01

    Full Text Available This paper examines the success of small-scale farming livelihoods in adapting to climate variability and change. We represent adaptation actions as choices within a response space that includes coping but also longer-term adaptation actions, and define success as those actions which promote system resilience, promote legitimate institutional change, and hence generate and sustain collective action. We explore data on social responses from four regions across South Africa and Mozambique facing a variety of climate risks. The analysis suggests that some collective adaptation actions enhance livelihood resilience to climate change and variability but others have negative spillover effects to other scales. Any assessment of successful adaptation is, however, constrained by the scale of analysis in terms of the temporal and spatial boundaries on the system being investigated. In addition, the diversity of mechanisms by which rural communities in southern Africa adapt to risks suggests that external interventions to assist adaptation will need to be sensitive to the location-specific nature of adaptation.

  20. Optimal design variable considerations in the use of phase change materials in indirect evaporative cooling

    Science.gov (United States)

    Chilakapaty, Ankit Paul

    The demand for sustainable, energy efficient and cost effective heating and cooling solutions is exponentially increasing with the rapid advancement of computation and information technology. Use of latent heat storage materials also known as phase change materials (PCMs) for load leveling is an innovative solution to the data center cooling demands. These materials are commercially available in the form of microcapsules dispersed in water, referred to as the microencapsulated phase change slurries and have higher heat capacity than water. The composition and physical properties of phase change slurries play significant role in energy efficiency of the cooling systems designed implementing these PCM slurries. Objective of this project is to study the effect of PCM particle size, shape and volumetric concentration on overall heat transfer potential of the cooling systems designed with PCM slurries as the heat transfer fluid (HTF). In this study uniform volume heat source model is developed for the simulation of heat transfer potential using phase change materials in the form of bulk temperature difference in a fully developed flow through a circular duct. Results indicate the heat transfer potential increases with PCM volumetric concentration with gradually diminishing returns. Also, spherical PCM particles offer greater heat transfer potential when compared to cylindrical particles. Results of this project will aid in efficient design of cooling systems based on PCM slurries.

  1. Disaster Loss Mitigation as an Adaptation to Climate Variability and Change

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, J.P. [Past Co-Chair, Intergovernmental Panel on Climate Change IPCC, Working Group 3, Geneva (Switzerland)

    1999-07-01

    Extremes of climate and weather, storms, floods and droughts, require vigorous adaptation measures in a generally stable climate or in one that is rapidly changing. These adaptation measures, to reduce loss of life, human suffering and economic losses come under the heading {sup d}isaster loss mitigation'. Since 1990 the United Nations' International Decade for Natural Disaster Reduction has provided for international cooperation and information dissemination. Nevertheless, world-wide economic disaster losses in the 1990s have continued to show a rapid increase - and the increase for climate related disasters has been three to four times greater than those for geological disasters. Is some of this increased loss due to anthropogenic climate change? There is some evidence of increases in frequency of heavy rainfalls in a number of regions and of severe winter storms in the northern hemisphere. On the other hand, there is little global trend in frequency or intensity of tropical cyclones whose geographical distribution is more closely related to ENSO events. But is there a possibility that increases in intensity over the past few decades of El Nino and La Nina events are related to increased radiative forcing from greenhouse gases? Whatever the outcome of emerging research on extreme events in a changing climate, it is evident that climate adaptation through disaster mitigation measures is of increasing importance with growing populations in more vulnerable regions. Measures that must be supported vigorously include improved warning and preparedness systems, safer buildings, risk-averse land use planning, better protected urban infrastructure, and more resilient water supply systems, among others. Both national and international efforts must not be allowed to diminish after the end of the IDNDR in 1999. The task is only begun. 32 refs.

  2. Assessing Holocene water level changes of Lake Turkana, Kenya with potential linkages to monsoon variability

    Science.gov (United States)

    Bloszies, C.; Forman, S. L.; Wright, D. K.

    2012-12-01

    This study focuses on better defining water level variability in the past 10 ka for Lake Turkana, Kenya. The water level of Lake Turkana was approximately 90m higher than today ca. 8 ka years ago, and in the past century lake levels have varied by up to 15 m. Lake level is especially sensitive to shifts in water balance with changes in regional rainfall linked to the relative strength of the Indian Ocean Monsoon. Variations in monsoonal precipitation in Kenya may be controlled by distinct modes of the Indian Ocean Dipole, with one mode associated with increased sea surface temperatures and concomitant heavy rainfall in the Turkana basin, and the other mode resulting in low precipitation. Well preserved beach ridges up to 90 m above present water level occur around the lake representing a record of varying elevations of lake level still-stands during the Holocene. Along this prograded strand plain there is evidence of a shift in human subsistence from fishing villages to pastoral encampments, possibly associated with pronounced mid-Holocene drying and a precipitous (>30 m) fall in lake level ca. between 7 and 5 ka. However, a recent GPS campaign of beach ridges on the east and west sides of the lake reveal variability in highstand beach ridge elevations, implying deferential tectonic deformation across the basin and possible crustal warping due to hydroisostatic processes. Radiocarbon dating of aquatic shells will resolve the ages of beach ridges and these ages will be tested by direct dating of littoral quartz grains by OSL. Stratigraphic exposures of this littoral system reveal new evidence for lake still-stands, transgressions and regressions. Ultimately, the data will constrain a basin hydrologic model to assess the catchment changes and evaporative conditions required to yield the tens of meters of lake level change in the Holocene and provide new insights into the magnitude and linkage to monsoon variability.

  3. Hundred years of environmental change and phytoplankton ecophysiological variability archived in coastal sediments.

    Directory of Open Access Journals (Sweden)

    Sofia Ribeiro

    Full Text Available Marine protist species have been used for several decades as environmental indicators under the assumption that their ecological requirements have remained more or less stable through time. However, a growing body of evidence suggests that marine protists, including several phytoplankton species, are in fact highly diverse and may quickly respond to changes in the environment. Predicting how future climate will impact phytoplankton populations is important, but this task has been challenged by a lack of time-series of ecophysiological parameters at time-scales relevant for climate studies (i.e. at least decadal. Here, we report on ecophysiological variability in a marine dinoflagellate over a 100-year period of well-documented environmental change, by using the sedimentary archive of living cysts from a Scandinavian fjord (Koljö Fjord, Sweden. During the past century, Koljö Fjord has experienced important changes in salinity linked to the North Atlantic Oscillation (NAO. We revived resting cysts of Pentapharsodinium dalei preserved in the fjord sediments and determined growth rates for 18 strains obtained from 3 sediment core layers at salinity 15 and 30, which represent extreme sea-surface conditions during periods of predominantly negative and positive NAO phases, respectively. Upper pH tolerance limits for growth were also tested. In general, P. dalei grew at a higher rate in salinity 30 than 15 for all layers, but there were significant differences among strains. When accounting for inter-strain variability, cyst age had no effect on growth performance or upper pH tolerance limits for this species, indicating a stable growth response over the 100-year period in spite of environmental fluctuations. Our findings give some support for the use of morphospecies in environmental studies, particularly at decadal to century scales. Furthermore, the high intra-specific variability found down to sediment layers dated as ca. 50 years-old indicates

  4. Change and Variability in East Antarctic Sea Ice Seasonality, 1979/80–2009/10

    Science.gov (United States)

    Massom, Robert; Reid, Philip; Stammerjohn, Sharon; Raymond, Ben; Fraser, Alexander; Ushio, Shuki

    2013-01-01

    Recent analyses have shown that significant changes have occurred in patterns of sea ice seasonality in West Antarctica since 1979, with wide-ranging climatic, biological and biogeochemical consequences. Here, we provide the first detailed report on long-term change and variability in annual timings of sea ice advance, retreat and resultant ice season duration in East Antarctica. These were calculated from satellite-derived ice concentration data for the period 1979/80 to 2009/10. The pattern of change in sea ice seasonality off East Antarctica comprises mixed signals on regional to local scales, with pockets of strongly positive and negative trends occurring in near juxtaposition in certain regions e.g., Prydz Bay. This pattern strongly reflects change and variability in different elements of the marine “icescape”, including fast ice, polynyas and the marginal ice zone. A trend towards shorter sea-ice duration (of 1 to 3 days per annum) occurs in fairly isolated pockets in the outer pack from∼95–110°E, and in various near-coastal areas that include an area of particularly strong and persistent change near Australia's Davis Station and between the Amery and West Ice Shelves. These areas are largely associated with coastal polynyas that are important as sites of enhanced sea ice production/melt. Areas of positive trend in ice season duration are more extensive, and include an extensive zone from 160–170°E (i.e., the western Ross Sea sector) and the near-coastal zone between 40–100°E. The East Antarctic pattern is considerably more complex than the well-documented trends in West Antarctica e.g., in the Antarctic Peninsula-Bellingshausen Sea and western Ross Sea sectors. PMID:23705008

  5. Change and variability in East antarctic sea ice seasonality, 1979/80-2009/10.

    Science.gov (United States)

    Massom, Robert; Reid, Philip; Stammerjohn, Sharon; Raymond, Ben; Fraser, Alexander; Ushio, Shuki

    2013-01-01

    Recent analyses have shown that significant changes have occurred in patterns of sea ice seasonality in West Antarctica since 1979, with wide-ranging climatic, biological and biogeochemical consequences. Here, we provide the first detailed report on long-term change and variability in annual timings of sea ice advance, retreat and resultant ice season duration in East Antarctica. These were calculated from satellite-derived ice concentration data for the period 1979/80 to 2009/10. The pattern of change in sea ice seasonality off East Antarctica comprises mixed signals on regional to local scales, with pockets of strongly positive and negative trends occurring in near juxtaposition in certain regions e.g., Prydz Bay. This pattern strongly reflects change and variability in different elements of the marine "icescape", including fast ice, polynyas and the marginal ice zone. A trend towards shorter sea-ice duration (of 1 to 3 days per annum) occurs in fairly isolated pockets in the outer pack from∼95-110°E, and in various near-coastal areas that include an area of particularly strong and persistent change near Australia's Davis Station and between the Amery and West Ice Shelves. These areas are largely associated with coastal polynyas that are important as sites of enhanced sea ice production/melt. Areas of positive trend in ice season duration are more extensive, and include an extensive zone from 160-170°E (i.e., the western Ross Sea sector) and the near-coastal zone between 40-100°E. The East Antarctic pattern is considerably more complex than the well-documented trends in West Antarctica e.g., in the Antarctic Peninsula-Bellingshausen Sea and western Ross Sea sectors.

  6. Change and variability in East antarctic sea ice seasonality, 1979/80-2009/10.

    Directory of Open Access Journals (Sweden)

    Robert Massom

    Full Text Available Recent analyses have shown that significant changes have occurred in patterns of sea ice seasonality in West Antarctica since 1979, with wide-ranging climatic, biological and biogeochemical consequences. Here, we provide the first detailed report on long-term change and variability in annual timings of sea ice advance, retreat and resultant ice season duration in East Antarctica. These were calculated from satellite-derived ice concentration data for the period 1979/80 to 2009/10. The pattern of change in sea ice seasonality off East Antarctica comprises mixed signals on regional to local scales, with pockets of strongly positive and negative trends occurring in near juxtaposition in certain regions e.g., Prydz Bay. This pattern strongly reflects change and variability in different elements of the marine "icescape", including fast ice, polynyas and the marginal ice zone. A trend towards shorter sea-ice duration (of 1 to 3 days per annum occurs in fairly isolated pockets in the outer pack from∼95-110°E, and in various near-coastal areas that include an area of particularly strong and persistent change near Australia's Davis Station and between the Amery and West Ice Shelves. These areas are largely associated with coastal polynyas that are important as sites of enhanced sea ice production/melt. Areas of positive trend in ice season duration are more extensive, and include an extensive zone from 160-170°E (i.e., the western Ross Sea sector and the near-coastal zone between 40-100°E. The East Antarctic pattern is considerably more complex than the well-documented trends in West Antarctica e.g., in the Antarctic Peninsula-Bellingshausen Sea and western Ross Sea sectors.

  7. Climate change projections of heat stress in Europe: From meteorological variables to impacts on productivity

    Science.gov (United States)

    Casanueva, Ana; Kotlarski, Sven; Liniger, Mark A.

    2017-04-01

    Future climate change is likely to have important impacts in many socio-economic sectors. In particular, higher summer temperatures or more prolonged heat waves may be responsible for health problems and productivity losses related to heat stress, especially affecting people exposed to such situations (e.g. working under outside settings or in non-acclimatized workplaces). Heat stress on the body under work load and consequently their productivity loss can be described through heat stress indices that are based on multiple meteorological parameters such as temperature, humidity, wind and radiation. Exploring the changes of these variables under a warmer climate is of prime importance for the Impacts, Adaptation and Vulnerability communities. In particular, the H2020 project HEAT-SHIELD aims at analyzing the impact of climate change on heat stress in strategic industries in Europe (manufacturing, construction, transportation, tourism and agriculture) within an inter-sectoral framework (climate scientists, biometeorologists, physiologists and stakeholders). In the present work we explore present and future heat stress over Europe using an ensemble of the state-of-the-art RCMs from the EURO-CORDEX initiative. Since RCMs cannot be directly used in impact studies due to their partly substantial biases, a standard bias correction method (empirical quantile mapping) is applied to correct the individual variables that are then used to derive heat stress indices. The objectives of this study are twofold, 1) to test the ability of the separately bias corrected variables to reproduce the main characteristics of heat stress indices in present climate conditions and 2) to explore climate change projections of heat stress indices. We use the wet bulb globe temperature (WBGT) as primary heat stress index, considering two different versions for indoor (or in the shade, based on temperature and humidity conditions) and outdoor settings (including also wind and radiation). The WBGT

  8. Spontaneous temporal changes and variability of peripheral nerve conduction analyzed using a random effects model

    DEFF Research Database (Denmark)

    Krøigård, Thomas; Gaist, David; Otto, Marit

    2014-01-01

    . Peroneal nerve distal motor latency, motor conduction velocity, and compound motor action potential amplitude; sural nerve sensory action potential amplitude and sensory conduction velocity; and tibial nerve minimal F-wave latency were examined in 51 healthy subjects, aged 40 to 67 years. They were...... reexamined after 2 and 26 weeks. There was no change in the variables except for a minor decrease in sural nerve sensory action potential amplitude and a minor increase in tibial nerve minimal F-wave latency. Reproducibility was best for peroneal nerve distal motor latency and motor conduction velocity...

  9. Dynamic Performance of Maximum Power Point Trackers in TEG Systems Under Rapidly Changing Temperature Conditions

    DEFF Research Database (Denmark)

    Man, E. A.; Sera, D.; Mathe, L.

    2016-01-01

    Characterization of thermoelectric generators (TEG) is widely discussed and equipment has been built that can perform such analysis. One method is often used to perform such characterization: constant temperature with variable thermal power input. Maximum power point tracking (MPPT) methods for T...

  10. Rapid analysis of time series data to identify changes in electricity consumption patterns in UK secondary schools

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, Graeme; Fleming, Paul; Ferreira, Vasco [Institute of Energy and Sustainable Development, De Montfort University, The Gateway, Leicester, LE1 9BH (United Kingdom); Harris, Peter [Cheriton Technology Management Ltd., Cambridge (United Kingdom)

    2007-04-15

    This paper presents a methodology for energy professionals to identify potential electricity saving opportunities in buildings from the analysis of half-hourly electricity consumption data. The technique recommended in UK government good practice guidance for use with monthly gas data has been applied to half-hourly electricity data from 37 secondary schools. The technique monitors consumption over time, identifying any changes in patterns and quantifying their effects. It has the advantage of being both high resolution and quick to employ. The analysis produces results that allow energy professionals to rapidly detect changes in electricity consumption. (author)

  11. Investigation of phase-change coatings for variable thermal control of spacecraft

    Science.gov (United States)

    Kelliher, W. C.; Young, P. R.

    1972-01-01

    An investigation was conducted to determine the feasibility of producing a spacecraft coating system that could vary the ratio of its solar absorptance to thermal emittance to adjust automatically for changes in the thermal balance of a spacecraft. This study resulted in a new concept called the phase-change effect which uses the change that occurs in the optical properties of many materials during the phase transition from a crystalline solid to an amorphous material. A series of two-component model coatings was developed which, when placed on a highly reflecting substrate, exhibited a sharp decrease in solar absorptance within a narrow temperature range. A variable thermal control coating can have a significant amount of temperature regulation with the phase-change effect. Data are presented on several crystallite-polymer formulations, their physical and optical properties, and associated phase-change temperatures. Aspects pertaining to their use in a space environment and an example of the degree of thermal regulation attainable with these coatings is also given.

  12. Automatic change detection in RapidEye data using the combined MAD and kernel MAF methods

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Hecheltjen, Antje; Thonfeld, Frank

    2010-01-01

    The IR-MAD components show changes for a large part of the entire subset. Especially phenological changes in the agricultural fields surrounding the open pit are predominant. As opposed to this, kMAF components focus more on changes in the open-cast mine (and changes due to the two clouds...... and their shadows, not visible in the zoom). Ground data were available from bucket-wheel excavators on the extraction side (to the northwest in the open pit) in terms of elevation data for both dates. No ground data were available for changes due to backfill (southeastern part of the open pit) or changes due...... to mining machines other than the bucket-wheels....

  13. Effects of rapid temperature changes on HK, PK and HSP70 of Litopenaeus vannamei in different seasons

    Science.gov (United States)

    Guo, Biao; Wang, Fang; Dong, Shuanglin; Hou, Chunqiang

    2010-09-01

    Activities of hexokinase (HK), pyruvate kinase (PK) and levels of HSP70 were measured to evaluate the response of Litopenaeus vannamei to rapid temperature changes under controlled laboratory conditions. Shrimps were subjected to a quick temperature change from 27°C to 17°C for the summer case (Cold temperature treatment), or from 17°C to 27°C for the winter case (Warm temperature treatment). After 0.5, 1, 3, 6, 12, 24, 48, and 72 h of exposure time, shrimps were sampled and prepared for further analysis. The results showed that the effect of acute temperature changes on activities of HK was significant. Patterns of variations of the two glycolytic enzymes suggested that enzymes in the glycolysis cycle could adjust their activities to meet the acute temperature change. The HSP70 level increased in both cold and warm temperature treatments, suggesting that the rapid temperature changes activated the process of body’s self-protection. But the difference in expression peak of HSP70 might be related to the different body size and the higher thermal sensitivity to temperature increase than to temperature decrease of L. vannamei.

  14. Rapid transformation of two libraries using Kotter's Eight Steps of Change

    National Research Council Canada - National Science Library

    Terrie R Wheeler; Kristi L Holmes

    2017-01-01

    Two new directors were each charged by their institutions to catalyze transformational change in their libraries and to develop dynamic and evolving information ecosystems ready for the information...

  15. Molar changes with cervical headgear alone or in combination with rapid maxillary expansion

    OpenAIRE

    Farret, Marcel Marchiori; Lima, Eduardo Martinelli Santayana de; Araújo, Vanessa Pereira de; Rizzatto, Susana Maria Deon; Menezes, Luciane Macedo de; Grossi, Márcio Lima

    2008-01-01

    Objective: To test the hypothesis that there is no difference in the distal movement of the maxillary first permanent molars when cervical headgear is used alone or in combination with rapid maxillary expansion. Materials and Methods: The sample was composed of 36 subjects (aged 9 to 13 years), treated in the Faculty of Dentistry, Pontifícia Universidade Católica, Rio Grande do Sul, Brazil. The individuals were in good health and in their pubertal growth period. All had Class II division 1 ma...

  16. Rapid change in the defense of flightless young by a mourning dove parent

    Science.gov (United States)

    Berdeen, James; Otis, D.L.

    2011-01-01

    We report that an adult-sized Zenaida macroura (Mourning Dove), presumably a parent, rapidly decreased risk taken in defense of a juvenile as the likelihood of predation to the juvenile increased. We attribute this decrease in risk taken to (1) the parent's perception that the risk of predation had increased to the extent that a continuation of defensive behaviors would not prevent the death of the juvenile, and (2) its attempt to minimize its own risk of death. It may be that there is a threshold beyond which Mourning Dove parents will forgo the risk of additional defense of offspring in favor of making another reproductive attempt.

  17. The change of genetic and phenotypic variability of yield components after recurrent selection of maize

    Directory of Open Access Journals (Sweden)

    Deletić Nebojša

    2009-01-01

    Full Text Available This paper deals with 31 SSD lines from ZP-Syn-1 C0 and 37 from ZP-Syn-1 C3 maize populations. After line selection and seed multiplication in the first year of the study, the trials were set during two years in Kruševac and Zemun Polje, in RCB design with three replications. Additive and phenotypic variances of yield components were calculated, as well as the estimation of genetic variability narrowing by multivariate cluster analysis. The differences in additive and phenotypic variances between the cycles were significant for ear length only and highly significant for grain row number per ear and for percent of root and stalk lodged plants. It means, a significant narrowing of additive and phenotypic variance occurred only for those three traits, and the other traits did not change their variability by selection in a significant manner. However, according to cluster analysis, distances among genotypes and groups in the zero selection cycle were approximately double than in the third one, but group definition was better in the third selection cycle. It can suggest indirectly to a total variability narrowing after three cycles of recurrent selection.

  18. Latent variable indirect response modeling of categorical endpoints representing change from baseline.

    Science.gov (United States)

    Hu, Chuanpu; Xu, Zhenhua; Mendelsohn, Alan M; Zhou, Honghui

    2013-02-01

    Accurate exposure-response modeling is important in drug development. Methods are still evolving in the use of mechanistic, e.g., indirect response (IDR) models to relate discrete endpoints, mostly of the ordered categorical form, to placebo/co-medication effect and drug exposure. When the discrete endpoint is derived using change-from-baseline measurements, a mechanistic exposure-response modeling approach requires adjustment to maintain appropriate interpretation. This manuscript describes a new modeling method that integrates a latent-variable representation of IDR models with standard logistic regression. The new method also extends to general link functions that cover probit regression or continuous clinical endpoint modeling. Compared to an earlier latent variable approach that constrained the baseline probability of response to be 0, placebo effect parameters in the new model formulation are more readily interpretable and can be separately estimated from placebo data, thus allowing convenient and robust model estimation. A general inherent connection of some latent variable representations with baseline-normalized standard IDR models is derived. For describing clinical response endpoints, Type I and Type III IDR models are shown to be equivalent, therefore there are only three identifiable IDR models. This approach was applied to data from two phase III clinical trials of intravenously administered golimumab for the treatment of rheumatoid arthritis, where 20, 50, and 70% improvement in the American College of Rheumatology disease severity criteria were used as efficacy endpoints. Likelihood profiling and visual predictive checks showed reasonable parameter estimation precision and model performance.

  19. Change in heart rate variability after the adult attachment interview in dissociative patients.

    Science.gov (United States)

    Farina, Benedetto; Speranza, Anna Maria; Imperatori, Claudio; Quintiliani, Maria Isabella; Della Marca, Giacomo

    2015-01-01

    The aim of this study was to assess heart rate variability (HRV) in individuals with dissociative disorders (DD) before and after the Adult Attachment Interview (AAI). Electrocardiograms were recorded before, during, and after the AAI in 13 individuals with DD and 13 healthy participants matched for age and gender. Significant change in HRV was observed only in the DD group. After the AAI, those with DD showed significant increases in the low frequency/high frequency ratio (pre-AAI = 1.91 ± 1.19; post-AAI = 4.03 ± 2.40; Wilcoxon test = -2.76, p = .005). Our results suggest that the retrieval of childhood attachment experiences in individuals with DD is associated with a change in HRV patterns that could reflect the emotion dysregulation of dissociative psychopathological processes.

  20. Fishers’ perception on livelihood strategies, adaptation and mitigation measures to cope with changes in climate variables around Lake Wamala, Uganda

    OpenAIRE

    Musinguzi, L.

    2015-01-01

    Fisheries support livelihoods but are threatened by climate variability and change which intensified since the 1970s. This study used quantitative and qualitative methods to determine the extent to which fishers around Lake Wamala in Uganda were copying with perceived changes in climate variables and the impacts on their livelihoods, to generate knowledge to enable the fishers increase resilience and sustain their livelihoods. Fishers were aware of changes in climate manifested by unpredictab...

  1. Are changes in the mean or variability of climate signals more important for long-term stochastic growth rate?

    Directory of Open Access Journals (Sweden)

    Bernardo García-Carreras

    Full Text Available Population dynamics are affected by changes in both the mean and standard deviation of climate, e.g., changes in average temperature are likely to affect populations, but so are changes in the strength of year-to-year temperature variability. The impacts of increases in average temperature are extensively researched, while the impacts of changes in climate variability are less studied. Is the greater attention given to changes in mean environment justified? To help answer this question we developed a simple population model, explicitly linked to an environmental process. We used the model to compare the sensitivities of a population's long-term stochastic growth rate, a measure of fitness, to changes in the mean and standard deviation of the environment. Results are interpreted in light of a comparative analysis of the relative magnitudes of change in means and standard deviations of biologically relevant climate variables in the United States. Results show that changes in the variability of the environment can be more important for many populations. Changes in mean conditions are likely to have a greater impact than changes in variability on populations far from their ideal environment, for example, populations near species range boundaries and potentially of conservation concern. Populations near range centres and close to their ideal environment are more likely to be affected by changes in variability. Among pest and insect disease vectors, as well as species of commercial value, populations likely to be of greatest economic and public health significance are those near species range centers, living in a near-ideal environment for the species. Observed changes in the variability of climate variables may benefit these populations.

  2. Mid to late Holocene Leeuwin Current variability offshore southern Australia linked to ENSO state changes

    Science.gov (United States)

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

    2015-04-01

    The El Niño-Southern Oscillation (ENSO), a key aspect of the Earth's climate, drives regional to global oceanic and climate changes on various time-scales. Differences in the temporal coverage of Holocene records for the more general state in El Niño frequency, however, restrict a comprehensive overview. Oceanic variability offshore southern Australia is linked to the Leeuwin Current (LC), an eastern boundary current, transporting tropical waters from the Indo Pacific Warm Pool region towards higher latitudes. Instrumental data, spanning the last few decades, document that ENSO modulates LC variability. Here we present new, well-dated time series from two marine sediment cores (MD03-2611 and SS0206-GC 15)of past LC variability, based on alkenone-derived sea-surface temperatures (SST) and planktonic foraminifera offshore southern Australia, an area affected by recent El Niño and La Niña events. Our reconstructions of ENSO-state changes cover the last 7,400 years. With transition into the mid Holocene [dates], we find clear evidence that oceanic conditions prevailed under the dominant influence of a persistent La Niña mode. A strong LC produces a stratified water column and establishes a permanent thermocline as seen in the high abundance of the 'tropical fauna' (Globoturborotalita rubescens, Globoturborotalita tenella and Globigerinella sacculifer (including G. trilobus)) and maximum SST offshore southern Australia. During this La Niña-state dominated period, we record at c. 5000 years BP the first short period of a strong El Niño-like-state, by a pronounced drop in abundance of the subtropical species Globigerinoides ruber and a reduced SST gradient between the two core sites. The Late Holocene (from 3,500 years BP onwards) period is characterized by centennial to millennial scale variability in the LC strength, which is accompanied by an overall decrease of SSTs offshore southern Australia. We link this LC variability to Late Holocene centennial

  3. Changes in heart rate variability during the induction and decay of heat acclimation.

    Science.gov (United States)

    Flouris, Andreas D; Poirier, Martin P; Bravi, Andrea; Wright-Beatty, Heather E; Herry, Christophe; Seely, Andrew J; Kenny, Glen P

    2014-10-01

    We evaluated the changes in core temperature, heart rate, and heart rate variability (HRV) during the induction and decay of heat acclimation. Ten males (23 ± 3 years; 79.5 ± 3.5 kg; 15.2 ± 4.5 percent body fat; 51.13 ± 4.61 mLO(2)∙kg(-1)∙min(-1) peak oxygen uptake) underwent a 14-day heat acclimation protocol comprising of 90-min cycling at ~50 % peak oxygen uptake at 40 °C and ~20 % relative humidity. Core temperature, heart rate, and 102 HRV measures were recorded during a heat tolerance test conducted at baseline (day 0) and at the end of the induction (day 14) and decay (day 28) phases. Heat acclimation resulted in significantly reduced core temperature [rectal (χ (2) = 1298.14, p rate (χ (2) = 1230.17, p heat acclimation-induced reductions in rectal temperature, esophageal temperature, and heart rate, respectively, were lost. Heat acclimation was accompanied by profound and broad changes in HRV: at the end of the induction phase, 75 of the 102 variability measures computed were significantly different (p Heat acclimation is accompanied by reduced core temperature, significant bradycardia, and marked alterations in HRV, which we interpret as being related to vagal dominance. The observed changes in core temperature persist for at least 2 weeks of non-exposure to heat, while the changes in heart rate and HRV decay faster and are only partly evident after 2 weeks of non-exposure to heat.

  4. Variability and changes of Arctic sea ice draft distribution – submarine sonar measurements revisited

    Directory of Open Access Journals (Sweden)

    J. Haapala

    2011-10-01

    Full Text Available Changes in the mean sea ice thickness and concentration in the Arctic are well known. However, quantitative information about changes in the ice thickness distribution and the composition of the pack ice is lacking. In this paper we determine the ice draft distributions, mean and modal thicknesses, and their regional and seasonal variability in the Arctic for the time period 1975–2000. We compare characteristics of the Arctic pack ice for the years 1975–1987 and 1988–2000. These periods represent different large-scale atmospheric circulation modes and sea ice circulation patterns, most evident in clearly weaker Beaufort Gyre and stronger as well as westward shifted Transpolar Drift during the later period. The comparison of these two periods reveals that the peak of sea ice draft distributions has narrowed and shifted toward thinner ice, with reductions in both mean and modal ice draft. These noticeable changes are attributed to the loss of thick, mostly deformed ice. Springtime, loss of ice volume with draft greater than 5 m exceeds 35 % in all regions except the Nansen Basin, with as much as 45 % or more at the North Pole and in the Eastern Arctic. Autumn volume reduction, mostly of deformed ice, exceeds 40 % in the Canada Basin only, but is above 30 % also in the Beaufort and Chukchi Seas. During the later period, the volume of ice category consisting thin, mostly level first-year ice, is clearly larger than during the former period, especially in the spring. In the Beaufort Sea region, changes in the composition of ice cover have resulted in a shift of modal draft from level multiyear ice draft range to values of level first-year ice. The regional and seasonal variability of sea ice draft has decreased, since the thinning has been most pronounced in regions with the thickest pack ice (the Western Arctic, and during the spring (0.6–0.8 m per decade.

  5. Short-term stream water temperature observations permit rapid assessment of potential climate change impacts

    Science.gov (United States)

    Peter Caldwell; Catalina Segura; Shelby Gull Laird; Ge Sun; Steven G. McNulty; Maria Sandercock; Johnny Boggs; James M. Vose

    2015-01-01

    Assessment of potential climate change impacts on stream water temperature (Ts) across large scales remains challenging for resource managers because energy exchange processes between the atmosphere and the stream environment are complex and uncertain, and few long-term datasets are available to evaluate changes over time. In this study, we...

  6. Impacts of Changing Climate on Agricultural Variability: Implications for Smallholder Farmers in India

    Science.gov (United States)

    Mondal, P.; Jain, M.; DeFries, R. S.; Galford, G. L.; Small, C.

    2013-12-01

    Agriculture is the largest employment sector in India, where food productivity, and thus food security, is highly dependent on seasonal rainfall and temperature. Projected increase in temperature, along with less frequent but intense rainfall events, will have a negative impact on crop productivity in India in the coming decades. These changes, along with continued ground water depletion, could have serious implications for Indian smallholder farmers, who are among some of the most vulnerable communities to climatic and economic changes. Hence baseline information on agricultural sensitivity to climate variability is important for strategies and policies that promote adaptation to climate variability. This study examines how cropping patterns in different agro-ecological zones in India respond to variations in precipitation and temperature. We specifically examine: a) which climate variables most influence crop cover for monsoon and winter crops? and b) how does the sensitivity of crop cover to climate variability vary in different agro-ecological regions with diverse socio-economic factors? We use remote sensing data (2000-01 - 2012-13) for cropping patterns (developed using MODIS satellite data), climate parameters (derived from MODIS and TRMM satellite data) and agricultural census data. We initially assessed the importance of these climate variables in two agro-ecoregions: a predominantly groundwater irrigated, cash crop region in western India, and a region in central India primarily comprised of rain-fed or surface water irrigated subsistence crops. Seasonal crop cover anomaly varied between -25% and 25% of the 13-year mean in these two regions. Predominantly climate-dependent region in central India showed high anomalies up to 200% of the 13-year crop cover mean, especially during winter season. Winter daytime mean temperature is overwhelmingly the most important climate variable for winter crops irrespective of the varied biophysical and socio

  7. High Order Accurate Algorithms for Shocks, Rapidly Changing Solutions and Multiscale Problems

    Science.gov (United States)

    2014-11-13

    convection boundary layer flow and heat transfer of non - Newtonian power law fluid over a cylinder. Different from most classical works, the temperature...dependent variable fluid viscosity and thermal conductivity are taken into account in highly coupled velocity and temperature fields. The motion of the...SECURITY CLASSIFICATION OF: Research has been performed on weighted essentially non -oscillatory schemes and discontinuous Galerkin methods, and other

  8. RAPID PENUMBRA AND LORENTZ FORCE CHANGES IN AN X1.0 SOLAR FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhe; Jiang, Yunchun; Yang, Jiayang; Yang, Bo; Bi, Yi, E-mail: xuzhe6249@ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China)

    2016-03-20

    We present observations of the violent changes in photospheric magnetic structures associated with an X1.1 flare, which occurred in a compact δ-configuration region in the following part of AR 11890 on 2013 November 8. In both central and peripheral penumbra regions of the small δ sunspot, these changes took place abruptly and permanently in the reverse direction during the flare: the inner/outer penumbra darkened/disappeared, where the magnetic fields became more horizontal/vertical. Particularly, the Lorentz force (LF) changes in the central/peripheral region had a downward/upward and inward direction, meaning that the local pressure from the upper atmosphere was enhanced/released. It indicates that the LF changes might be responsible for the penumbra changes. These observations can be well explained as the photospheric response to the coronal field reconstruction within the framework of the magnetic implosion theory and the back reaction model of flares.

  9. Rapid transformation of two libraries using Kotter's Eight Steps of Change.

    Science.gov (United States)

    Wheeler, Terrie R; Holmes, Kristi L

    2017-07-01

    Two new directors were each charged by their institutions to catalyze transformational change in their libraries and to develop dynamic and evolving information ecosystems ready for the information challenges of the future. The directors approached this transformational change using a strategic, forward-looking approach. This paper presents examples of actions that served as catalysts for change at the two libraries using Kotter's Eight Steps of Change as a framework. Small and large changes are critical for successfully transforming library services, resources, and personnel. Libraries are faced with incredible pressure to adapt to meet emerging and intensifying information needs on today's academic medical campuses. These pressures offer an opportunity for libraries to accelerate their evolution at the micro and macro levels. This commentary reports the expansion of new services and areas of support, enhancement of professional visibility of the libraries on their campuses, and overall, a more positive and productive environment at the respective institutions.

  10. Microstructure Formation and Resistivity Change in CuCr during Rapid Solidification

    Directory of Open Access Journals (Sweden)

    Ulla Hauf

    2017-11-01

    Full Text Available The formation of the surface-near microstructure after a current interruption of CuCr contact materials in a vacuum interrupter is characterized by a fast heating and subsequently rapid solidification process. In the present article, we reveal and analyse the formation of two distinct microstructural regions that result from the heat, which is generated and dissipated during interruption. In the topmost region, local and global texture, as well as the resulting microstructure, indicate that both Cu and Cr were melted during rapid heating and solidification whereas in the region underneath, only Cu was melted and elongated Cu-grains solidified with the <001>-direction perpendicularly aligned to the surface. By analysing the lattice parameter of the Cu solid solution, a supersaturation of the solid solution with about 2.25 at % Cr was found independent if Cu was melted solely or together with the Cr. The according reduction of electrical conductivity in the topmost region subsequent to current interruption and the resulting heat distribution are discussed based on these experimental results.

  11. The impact of climate variability and change on cryptosporidiosis and giardiasis rates in New Zealand.

    Science.gov (United States)

    Britton, Emma; Hales, Simon; Venugopal, Kamalesh; Baker, Michael G

    2010-09-01

    To investigate the spatial relationship between climate variability and cryptosporidiosis and giardiasis notifications in New Zealand between 1997 and 2006. Negative binomial regression was used to analyse spatial relationships between cryptosporidiosis and giardiasis notifications in New Zealand between 1997 and 2006, and climatological average rainfall and temperature at the Census Area Unit (CAU) level. The quality of domestic water supplies, urban-rural status and deprivation were included as covariates. Giardiasis: There was a positive association between rainfall and giardiasis and between temperature and giardiasis.Cryptosporidiosis: There was a positive association between rainfall and cryptosporidiosis and a negative association between temperature and cryptosporidiosis. The effect of rainfall was modified by the quality of the domestic water supply. These findings suggest that climate variability affects protozoan disease rates in New Zealand. However, predicting the effect of climate change from this study is difficult, as these results suggest that the projected increases in temperature and rainfall may have opposing effects on cryptosporidiosis rates. Nevertheless, water supply quality appeared to modify the impact of increased rainfall on cryptosporidiosis rates. This finding suggests that improving water supply quality in New Zealand could reduce vulnerability to the impact of climate change on protozoan diseases.

  12. The Mechanisms of Natural Variability and its Interaction with Anthropogenic Climate Change Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Vallis, Geoffrey K. [Princeton Univ., NJ (United States)

    2015-01-30

    The project had two main components. The first concerns estimating the climate sensitivity in the presence of forcing uncertainty and natural variability. Climate sensitivity is the increase in the average surface temperature for a given increase in greenhouse gases, for example a doubling of carbon dioxide. We have provided new, probabilistic estimates of climate sensitivity using a simple climate model an the observed warming in the 20th century, in conjunction with ideas in data assimilation and parameter estimation developed in the engineering community. The estimates combine the uncertainty in the anthropogenic aerosols with the uncertainty arising because of natural variability. The second component concerns how the atmospheric circulation itself might change with anthropogenic global warming. We have shown that GCMs robustly predict an increase in the length scale of eddies, and we have also explored the dynamical mechanisms whereby there might be a shift in the latitude of the jet stream associated with anthropogenic warming. Such shifts in the jet might cause large changes in regional climate, potentially larger than the globally-averaged signal itself. We have also shown that the tropopause robustly increases in height with global warming, and that the Hadley Cell expands, and that the expansion of the Hadley Cell is correlated with the polewards movement of the mid-latitude jet.

  13. Trend Change Detection in NDVI Time Series: Effects of Inter-Annual Variability and Methodology

    Science.gov (United States)

    Forkel, Matthias; Carvalhais, Nuno; Verbesselt, Jan; Mahecha, Miguel D.; Neigh, Christopher S.R.; Reichstein, Markus

    2013-01-01

    Changing trends in ecosystem productivity can be quantified using satellite observations of Normalized Difference Vegetation Index (NDVI). However, the estimation of trends from NDVI time series differs substantially depending on analyzed satellite dataset, the corresponding spatiotemporal resolution, and the applied statistical method. Here we compare the performance of a wide range of trend estimation methods and demonstrate that performance decreases with increasing inter-annual variability in the NDVI time series. Trend slope estimates based on annual aggregated time series or based on a seasonal-trend model show better performances than methods that remove the seasonal cycle of the time series. A breakpoint detection analysis reveals that an overestimation of breakpoints in NDVI trends can result in wrong or even opposite trend estimates. Based on our results, we give practical recommendations for the application of trend methods on long-term NDVI time series. Particularly, we apply and compare different methods on NDVI time series in Alaska, where both greening and browning trends have been previously observed. Here, the multi-method uncertainty of NDVI trends is quantified through the application of the different trend estimation methods. Our results indicate that greening NDVI trends in Alaska are more spatially and temporally prevalent than browning trends. We also show that detected breakpoints in NDVI trends tend to coincide with large fires. Overall, our analyses demonstrate that seasonal trend methods need to be improved against inter-annual variability to quantify changing trends in ecosystem productivity with higher accuracy.

  14. Plant trait diversity buffers variability in denitrification potential over changes in season and soil conditions.

    Science.gov (United States)

    McGill, Bonnie M; Sutton-Grier, Ariana E; Wright, Justin P

    2010-07-16

    Denitrification is an important ecosystem service that removes nitrogen (N) from N-polluted watersheds, buffering soil, stream, and river water quality from excess N by returning N to the atmosphere before it reaches lakes or oceans and leads to eutrophication. The denitrification enzyme activity (DEA) assay is widely used for measuring denitrification potential. Because DEA is a function of enzyme levels in soils, most ecologists studying denitrification have assumed that DEA is less sensitive to ambient levels of nitrate (NO(3)(-)) and soil carbon and thus, less variable over time than field measurements. In addition, plant diversity has been shown to have strong effects on microbial communities and belowground processes and could potentially alter the functional capacity of denitrifiers. Here, we examined three questions: (1) Does DEA vary through the growing season? (2) If so, can we predict DEA variability with environmental variables? (3) Does plant functional diversity affect DEA variability? The study site is a restored wetland in North Carolina, US with native wetland herbs planted in monocultures or mixes of four or eight species. We found that denitrification potentials for soils collected in July 2006 were significantly greater than for soils collected in May and late August 2006 (pmoisture, organic matter, total inorganic nitrogen, and microbial biomass--none consistently explained the pattern observed in DEA through time. There was no significant relationship between DEA and plant species richness or functional diversity. However, the seasonal variance in microbial biomass standardized DEA rates was significantly inversely related to plant species functional diversity (pplant functional diversity may support a more constant level of DEA through time, buffering the ecosystem from changes in season and soil conditions.

  15. Role of internal variability in recent decadal to multidecadal tropical Pacific climate changes

    Science.gov (United States)

    Bordbar, Mohammad Hadi; Martin, Thomas; Latif, Mojib; Park, Wonsun

    2017-05-01

    While the Earth's surface has considerably warmed over the past two decades, the tropical Pacific has featured a cooling of sea surface temperatures in its eastern and central parts, which went along with an unprecedented strengthening of the equatorial trade winds, the surface component of the Pacific Walker Circulation (PWC). Previous studies show that this decadal trend in the trade winds is generally beyond the range of decadal trends simulated by climate models when forced by historical radiative forcing. There is still a debate on the origin of and the potential role that internal variability may have played in the recent decadal surface wind trend. Using a number of long control (unforced) integrations of global climate models and several observational data sets, we address the question as to whether the recent decadal to multidecadal trends are robustly classified as an unusual event or the persistent response to external forcing. The observed trends in the tropical Pacific surface climate are still within the range of the long-term internal variability spanned by the models but represent an extreme realization of this variability. Thus, the recent observed decadal trends in the tropical Pacific, though highly unusual, could be of natural origin. We note that the long-term trends in the selected PWC indices exhibit a large observational uncertainty, even hindering definitive statements about the sign of the trends.Plain Language SummaryWhile the Earth's surface has considerably warmed over the past two decades, the tropical Pacific has featured a cooling of sea surface temperatures in its eastern and central parts, which went along with an unprecedented strengthening of the equatorial trade winds. Here we show that climate models simulate a high level of internal variability, so that the recent changes in the tropical Pacific could still be due to natural processes.

  16. Effects of climate variability and functional changes on carbon cycling in a temperate deciduous forest

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jian

    2013-03-15

    Temperate forests are globally important carbon (C) stocks and sinks. A decadal (1997-2009) trend of increasing C uptake has been observed in an intensively studied temperate deciduous forest, Soroe (Zealand, Denmark). This gave the impetus to investigate the factors controlling the C cycling and the fundamental processes at work in this type of ecosystem. The major objectives of this study were to (1) evaluate to what extent and at what temporal scales, direct climatic variability and functional changes (e.g. changes in the structure or physiological properties) regulate the interannual variability (IAV) in the ecosystem C balance; (2) provide a synthesis of the ecosystem C budget at this site and (3) investigate whether terrestrial ecosystem models can dynamically simulate the trend of increasing C uptake. Data driven analysis, semi-empirical and process-based modelling experiments were performed in a series of studies in order to provide a complete assessment of the carbon storage and allocation within the ecosystem and clarify the mechanisms responsible for the observed variability and trend in the ecosystem C fluxes. Combining all independently estimated ecosystem carbon budget (ECB) datasets and other calculated ECB components based on mass balance equations, a synthesis of the carbon cycling was performed. The results showed that this temperature deciduous forest was moderately productive with both high rates of gross primary production and ecosystem respiration. Approximately 62% of the gross assimilated carbon was respired by the living plants, while 21% was contributed to the soil as litter production, the latter balancing the total heterotrophic respiration. The remaining 17% was either stored in the plants (mainly as aboveground biomass) or removed from the system as wood production. In general, the ECB component datasets were consistent after the cross-checking. This, together with their characterized uncertainties, can be used in model data fusion

  17. Evidence that implicit assumptions of ‘no evolution’ of disease vectors in changing environments can be violated on a rapid timescale

    Science.gov (United States)

    Egizi, Andrea; Fefferman, Nina H.; Fonseca, Dina M.

    2015-01-01

    Projected impacts of climate change on vector-borne disease dynamics must consider many variables relevant to hosts, vectors and pathogens, including how altered environmental characteristics might affect the spatial distributions of vector species. However, many predictive models for vector distributions consider their habitat requirements to be fixed over relevant time-scales, when they may actually be capable of rapid evolutionary change and even adaptation. We examine the genetic signature of a spatial expansion by an invasive vector into locations with novel temperature conditions compared to its native range as a proxy for how existing vector populations may respond to temporally changing habitat. Specifically, we compare invasions into different climate ranges and characterize the importance of selection from the invaded habitat. We demonstrate that vector species can exhibit evolutionary responses (altered allelic frequencies) to a temperature gradient in as little as 7–10 years even in the presence of high gene flow, and further, that this response varies depending on the strength of selection. We interpret these findings in the context of climate change predictions for vector populations and emphasize the importance of incorporating vector evolution into models of future vector-borne disease dynamics. PMID:25688024

  18. Rapid and quantitative evaluation of the effect of process variables on the kinetics of photocatalytic degradation of phenol using experimental design techniques and parallel factor (PARAFAC) analysis.

    Science.gov (United States)

    Bosco, Marta; Larrechi, M Soledad

    2008-02-01

    A 2(3) factorial design has been used to analyze the effect of pH, the nature of the catalyst, and the concentration of the substrate on the rate constant of the photodegradation reaction of phenol. The main effects of the considered variables and their interaction are discussed. The significance of the effects has been corroborated using an ANOVA test. The values of phenol concentrations, used to calculate the rate constant, and the concentrations of intermediates were obtained by applying parallel factor (PARAFAC) analysis to the data obtained from monitoring the process by means of excitation-emission fluorescence (EEM). The proposed methodology, which combines experimental design and multivariate techniques, is a rapid alternative for study of chemical kinetics.

  19. Television, disordered eating, and young women in Fiji: negotiating body image and identity during rapid social change.

    Science.gov (United States)

    Becker, Anne E

    2004-12-01

    Although the relationship between media exposure and risk behavior among youth is established at a population level, the specific psychological and social mechanisms mediating the adverse effects of media on youth remain poorly understood. This study reports on an investigation of the impact of the introduction of television to a rural community in Western Fiji on adolescent ethnic Fijian girls in a setting of rapid social and economic change. Narrative data were collected from 30 purposively selected ethnic Fijian secondary school girls via semi-structured, open-ended interviews. Interviews were conducted in 1998, 3 years after television was first broadcast to this region of Fiji. Narrative data were analyzed for content relating to response to television and mechanisms that mediate self and body image in Fijian adolescents. Data in this sample suggest that media imagery is used in both creative and destructive ways by adolescent Fijian girls to navigate opportunities and conflicts posed by the rapidly changing social environment. Study respondents indicated their explicit modeling of the perceived positive attributes of characters presented in television dramas, but also the beginnings of weight and body shape preoccupation, purging behavior to control weight, and body disparagement. Response to television appeared to be shaped by a desire for competitive social positioning during a period of rapid social transition. Understanding vulnerability to images and values imported with media will be critical to preventing disordered eating and, potentially, other youth risk behaviors in this population, as well as other populations at risk.

  20. Changes in Variable Number of Tandem Repeats in 'Candidatus Liberibacter asiaticus' through Insect Transmission.

    Directory of Open Access Journals (Sweden)

    Hiroshi Katoh

    Full Text Available Citrus greening (huanglongbing is the most destructive citrus disease worldwide. The disease is associated with three species of 'Candidatus Liberibacter' among which 'Ca. Liberibacter asiaticus' has the widest distribution. 'Ca. L. asiaticus' is commonly transmitted by a phloem-feeding insect vector, the Asian citrus psyllid Diaphorina citri. A previous study showed that isolates of 'Ca. L. asiaticus' were clearly differentiated by variable number of tandem repeat (VNTR profiles at four loci in the genome. In this study, the VNTR analysis was further validated by assessing the stability of these repeats after multiplication of the pathogen upon host-to-host transmission using a 'Ca. L. asiaticus' strain from Japan. The results showed that some tandem repeats showed detectable changes after insect transmission. To our knowledge, this is the first report to demonstrate that the repeat numbers VNTR 002 and 077 of 'Ca. L. asiaticus' change through psyllid transmission. VNTRs in the recipient plant were apparently unrelated to the growing phase of the vector. In contrast, changes in the number of tandem repeats increased with longer acquisition and inoculation access periods, whereas changes were not observed through psyllid transmission after relatively short acquisition and inoculation access periods, up to 20 and 19 days, respectively.

  1. California Getting Wetter to the North, Drier to the South: Natural Variability or Climate Change?

    Directory of Open Access Journals (Sweden)

    Dan Killam

    2014-08-01

    Full Text Available Current climate change projections anticipate that global warming trends will lead to changes in the distribution and intensity of precipitation at a global level. However, few studies have corroborated these model-based results using historical precipitation records at a regional level, especially in our study region, California. In our analyses of 14 long-term precipitation records representing multiple climates throughout the state, we find northern and central regions increasing in precipitation while southern regions are drying. Winter precipitation is increasing in all regions, while other seasons show mixed results. Rain intensity has not changed since the 1920s. While Sacramento shows over 3 more days of rain per year, Los Angeles has almost 4 less days per year in the last century. Both the El Niño-Southern Oscillation (ENSO and the Pacific Decadal Oscillation (PDO greatly influence the California precipitation record. The climate change signal in the precipitation records remains unclear as annual variability overwhelms the precipitation trends.

  2. Understanding the rapid summer warming and changes in temperature extremes since the mid-1990s over Western Europe

    Science.gov (United States)

    Dong, Buwen; Sutton, Rowan T.; Shaffrey, Len

    2017-03-01

    Analysis of observations indicates that there was a rapid increase in summer (June-August) mean surface air temperature (SAT) since the mid-1990s over Western Europe. Accompanying this rapid warming are significant increases in summer mean daily maximum temperature, daily minimum temperature, annual hottest day temperature and warmest night temperature, and an increase in frequency of summer days and tropical nights, while the change in the diurnal temperature range (DTR) is small. This study focuses on understanding causes of the rapid summer warming and associated temperature extreme changes. A set of experiments using the atmospheric component of the state-of-the-art HadGEM3 global climate model have been carried out to quantify relative roles of changes in sea surface temperature (SST)/sea ice extent (SIE), anthropogenic greenhouse gases (GHGs), and anthropogenic aerosols (AAer). Results indicate that the model forced by changes in all forcings reproduces many of the observed changes since the mid-1990s over Western Europe. Changes in SST/SIE explain 62.2 ± 13.0 % of the area averaged seasonal mean warming signal over Western Europe, with the remaining 37.8 ± 13.6 % of the warming explained by the direct impact of changes in GHGs and AAer. Results further indicate that the direct impact of the reduction of AAer precursor emissions over Europe, mainly through aerosol-radiation interaction with additional contributions from aerosol-cloud interaction and coupled atmosphere-land surface feedbacks, is a key factor for increases in annual hottest day temperature and in frequency of summer days. It explains 45.5 ± 17.6 % and 40.9 ± 18.4 % of area averaged signals for these temperature extremes. The direct impact of the reduction of AAer precursor emissions over Europe acts to increase DTR locally, but the change in DTR is countered by the direct impact of GHGs forcing. In the next few decades, greenhouse gas concentrations will continue to rise and AAer precursor

  3. Global change ecotoxicology: Identification of early life history bottlenecks in marine invertebrates, variable species responses and variable experimental approaches.

    Science.gov (United States)

    Byrne, M

    2012-05-01

    Climate change is a threat to marine biota because increased atmospheric CO₂ is causing ocean warming, acidification, hypercapnia and decreased carbonate saturation. These stressors have toxic effects on invertebrate development. The persistence and success of populations requires all ontogenetic stages be completed successfully and, due to their sensitivity to environmental stressors, developmental stages may be a population bottleneck in a changing ocean. Global change ecotoxicology is being used to identify the marine invertebrate developmental stages vulnerable to climate change. This overview of research, and the methodologies used, shows that most studies focus on acidification, with few studies on ocean warming, despite a long history of research on developmental thermotolerance. The interactive effects of stressors are poorly studied. Experimental approaches differ among studies. Fertilization in many species exhibits a broad tolerance to warming and/or acidification, although different methodologies confound inter-study comparisons. Early development is susceptible to warming and most calcifying larvae are sensitive to acidification/increased pCO₂. In multistressor studies moderate warming diminishes the negative impact of acidification on calcification in some species. Development of non-calcifying larvae appears resilient to near-future ocean change. Although differences in species sensitivities to ocean change stressors undoubtedly reflect different tolerance levels, inconsistent handling of gametes, embryos and larvae probably influences different research outcomes. Due to the integrative 'developmental domino effect', life history responses will be influenced by the ontogenetic stage at which experimental incubations are initiated. Exposure to climate change stressors from early development (fertilization where possible) in multistressor experiments is needed to identify ontogenetic sensitivities and this will be facilitated by more consistent

  4. Rapid land-use change and its impacts on tropical biodiversity

    Science.gov (United States)

    Laurance, William F.

    Rates of forest conversion are extremely high in most tropical regions and these changes are known to have important impacts on biotas and ecosystems. I summarize available information on responses of wildlife and plant communities to habitat fragmentation, selective logging, surface fires, and hunting, which are four of the most widespread types of tropical land-use change. These changes alter forest ecosystems in complex ways and have varying impacts on different animal and plant species. In most human-dominated landscapes, forests are subjected to not one change but to two or more simultaneous alterations, the effects of which can be particularly destructive to tropical biotas. I illustrate this concept by describing the synergistic interactions between habitat fragmentation and surface fires, and between logging, fires, and hunting.

  5. Colorado Plateau Rapid Ecoregion Assessment Terrestrial Intactness and Potential For Change

    Data.gov (United States)

    Bureau of Land Management, Department of the Interior — This map shows current and near-term terrestrial intactness, as well as long term potential for development and climate change. These datasets are the results of a...

  6. Colorado Plateau Rapid Ecoregion Assessment Terrestrial Intactness and Potential For Change (HUC5)

    Data.gov (United States)

    Bureau of Land Management, Department of the Interior — This map shows current and near-term terrestrial intactness, as well as long term potential for development and climate change. These datasets are the results of a...

  7. Variables predicting change in benign melanocytic nevi undergoing short-term dermoscopic imaging.

    Science.gov (United States)

    Menzies, Scott W; Stevenson, Mary L; Altamura, Davide; Byth, Karen

    2011-06-01

    To determine whether certain patient demographics are associated with poorer specificity for the diagnosis of melanoma in nevi undergoing short-term sequential digital dermoscopic imaging. Retrospective cohort study performed from April 1, 1998, through May 31, 2007. Sydney Melanoma Diagnostic Centre, a tertiary referral institution. A total of 2497 benign melanocytic lesions in 1765 patients undergoing short-term sequential digital dermoscopic imaging during 2.5 to 4.5 months (42.3% male; mean [SD] age, 40 [14] years; age range, 1-86 years). Proportion of changed nevi as a function of age, sex, lesion diameter, and anatomical site. The only variable significantly associated with nevus change was age group (P = .002). When compared with the middle-aged (aged 36-50 years) group, the odds of change were significantly increased in the child and adolescent (aged 0-18 years: odds ratio, 2.60; 95% confidence interval, 1.30-5.22), young adult (aged 19-35 years: 1.50; 1.04-2.17), and elderly (> 65 years old: 2.04; 1.04-3.99) age groups. Within the changed benign lesions, a significant association was observed between histologic subtype and age group (P = .01). The proportion of changed lesions of the banal nevi type decreased and the proportion of the dysplastic nevi type increased with age. In the elderly group, 75.9% of changed lesions were of the dysplastic nevi type compared with 35.7% in the youngest group. A poorer specificity is observed for the diagnosis of melanoma for nevi undergoing short-term sequential digital dermoscopic imaging in children and adolescents (75.7%) and elderly patients (77.9%) compared with other patients (84.6%).

  8. Implications of Human Activities, Land Use Changes and Climate Variability in Mediterranean Lakes of Greece

    Directory of Open Access Journals (Sweden)

    Konstantinos Stefanidis

    2016-10-01

    Full Text Available Lakes in the Mediterranean climate zone experience high variation in rainfall and are vulnerable to changes in climate, land cover and anthropogenically induced effects on water level and salinity. This paper presents the results from the analyses of spatiotemporal changes of land cover/uses at catchment scale of two connected lakes in Greece that have recently exhibited a dramatic loss of water volume, and investigates the potential role of climate change as a main driver of the lake water loss. The classification of the historical land cover/uses was based on a series of LANDSAT images from 1972 to 2011. Changes in the landscape structure were assessed using landscape metrics that were calculated with FRAGSTATS software. Climate data and temporal series of water level, conductivity and chloride concentration, were analyzed to investigate the potential role of climate variability to the lake hydrology and water quality. The results showed that between 1972 and 2011 almost 28% of Lake Vegoritis and 13% of Lake Petron were replaced by cultivations and reed beds. Landscape metrics showed that the lake catchment’s area is highly fragmented, indicating a heterogeneous spatial pattern and degradation of the rural habitats. Regarding the climatic factors, it appears that precipitation follows a declining trend correlating with water level fluctuations. The water level in Lake Vegoritis also correlated with the conductivity and chloride concentration, indicating a relationship between hydrological alteration and water quality. Overall, a combined effect of climate- and human-induced land cover changes appeared to be responsible for the drastic environmental changes that urge the need for implementing effective restoration and mitigation measures.

  9. Changes in tree functional composition amplify the response of forest biomass to climate variability

    Science.gov (United States)

    Lichstein, Jeremy; Zhang, Tao; Niinemets, Ulo; Sheffield, Justin

    2017-04-01

    The response of forest carbon storage to climate change is highly uncertain, contributing substantially to the divergence among global climate model projections. Numerous studies have documented responses of forest ecosystems to climate change and variability, including drought-induced increases in tree mortality rates. However, the sensitivity of forests to climate variability - in terms of both biomass carbon storage and functional components of tree species composition - has yet to be quantified across a large region using systematically sampled data. Here, we combine systematic forest inventories across the eastern USA with a species-level drought-tolerance index, derived from a meta-analysis of published literature, to quantify changes in forest biomass and community-mean-drought-tolerance in one-degree grid cells from the 1980s to 2000s. We show that forest biomass responds to decadal-scale changes in water deficit and that this biomass response is amplified by concurrent changes in community-mean-drought-tolerance. The amplification of the direct effects of water stress on biomass occurs because water stress tends to induce a shift in tree species composition towards more drought-tolerant but lower-biomass species. Multiple plant functional traits are correlated with the above species-level drought-tolerance index, and likely contribute to the decrease in biomass with increasing drought-tolerance. These traits include wood density and P50 (the xylem water potential at which a plant loses 50% of its hydraulic conductivity). Simulations with a trait- and competition-based dynamic global vegetation model suggest that species differences in plant carbon allocation to wood, leaves, and fine roots also likely contribute to the observed decrease in biomass with increasing drought-tolerance, because competition drives plants to over-invest in fine roots when water is limiting. Thus, the most competitive species under dry conditions have greater root allocation but

  10. Climate variability rather than overstocking causes recent large scale cover changes of Tibetan pastures

    Science.gov (United States)

    Lehnert, Lukas; Wesche, Karsten; Trachte, Katja; Reudenbach, Christoph; Miehe, Georg; Bendix, Jörg

    2016-04-01

    The Tibetan Plateau has been entitled "Third-Pole-Environment" because of its outstanding importance for the climate and the hydrology in East and South-east Asia. Its climatological and hydrological influences are strongly affected by the local grassland vegetation which is supposed to be subject to ongoing degradation. On a local scale, numerous studies focused on grassland degradation of the Tibetan pastures. However, because methods and scales substantially differed among previous studies, the overall pattern of the degradation in the Tibetan Plateau is unknown. Consequently, a satellite based approach was selected to cope with the spatial limitations. Therefore, a MODIS-based vegetation cover product was developed which is fully validated against 600 in situ measurements covering a wide extent of the Tibetan Plateau. The vegetation cover as a proxy for grassland degradation is modelled with low error rates using support vector machine regressions. To identify the changes in the vegetation cover, the trends seen in the new vegetation cover product since the beginning of the new millennium were analysed. The drivers of the vegetation changes were identified by the analysis of trends of climatic variables (precipitation and 2 m air temperature) and land-use (livestock numbers) over the same time. The results reveal that - in contrast to the prevailing opinion - pasture degradation on the Tibetan Plateau is not a generally proceeding process because areas of positive and negative changes are almost equal in extent. The positive and negative vegetation changes have regionally different triggers: While, from 2000 on, the vegetation cover has increased in the north-eastern part of the Tibetan Plateau due to increasing precipitation, it has declined in the central and western parts due to rising air temperature and declining precipitation. Increasing livestock numbers as a result of land use changes exacerbated the negative trends but, contrarily to the assumptions of

  11. People On The Move: Some Thoughts On Human Dispersal In Relation To Rapid Climatic Change

    Science.gov (United States)

    Davies, W.

    It is still generally assumed that the default situation for past humans must have been to be sedentary. That is to say, given a chance people would have settled in one area (with a good supply of resources) and established clearly-defined territories. Such concepts presuppose that much of human existence was conducted in climatic conditions sim- ilar to the relatively stable ones seen in the Holocene. What effects do rapid climatic fluctuations have upon environmental carrying capacity, and thus upon human mobil- ity and exploitation patterns? Such an approach could be called 'non-analogue', as it does not seek to impose [current] Holocene patterns upon the Pleistocene, in the same way that 'non-analogue' animal and plant communities are now routinely described for the same period. If one adopts non-analogue perspectives, perhaps one could also argue that in many cases mobility was the rule and not the exception. Turning the conventional wisdom around, we can ask why people should remain in an area. What are the characteristics of that area which could have encouraged people to become less mobile? I do not argue that all groups were mobile: some cannot have been, and not every member of other groups would have been equally mobile (differentiation on grounds of age and sex). In addition, mobility patterns must also have varied over time, although we should not necessarily expect a discernible linear trend either towards or away from greater mobility, because such behaviour operates within a climatic and environmental framework as well as a socio-economic one. If climate oscillated rapidly, it is feasible to suggest that such fluctuations affected environmental stability and thus carrying capacity. The resource species present and their availability would therefore affect the possibilities for human mobility. When discussing the possibilities for human dispersal into new regions, we essentially have a choice between two competing models: the Wave of Advance (sensu

  12. Evidence from phylogenetic and genome fingerprinting analyses suggests rapidly changing variation in Halorubrum and Haloarcula populations

    Science.gov (United States)

    Ram Mohan, Nikhil; Fullmer, Matthew S.; Makkay, Andrea M.; Wheeler, Ryan; Ventosa, Antonio; Naor, Adit; Gogarten, J. Peter; Papke, R. Thane

    2014-01-01

    Halobacteria require high NaCl concentrations for growth and are the dominant inhabitants of hypersaline environments above 15% NaCl. They are well-documented to be highly recombinogenic, both in frequency and in the range of exchange partners. In this study, we examine the genetic and genomic variation of cultured, naturally co-occurring environmental populations of Halobacteria. Sequence data from multiple loci (~2500 bp) identified many closely and more distantly related strains belonging to the genera Halorubrum and Haloarcula. Genome fingerprinting using a random priming PCR amplification method to analyze these isolates revealed diverse banding patterns across each of the genera and surprisingly even for isolates that are identical at the nucleotide level for five protein coding sequenced loci. This variance in genome structure even between identical multilocus sequence analysis (MLSA) haplotypes indicates that accumulation of genomic variation is rapid: faster than the rate of third codon substitutions. PMID:24782838

  13. Evidence from phylogenetic and genome fingerprinting analyses suggests rapidly changing variation in Halorubrum and Haloarcula populations

    Directory of Open Access Journals (Sweden)

    Nikhil eRam Mohan

    2014-04-01

    Full Text Available Halobacteria require high NaCl concentrations for growth and are the dominant inhabitants of hypersaline environments above 15% NaCl. They are well documented to be highly recombinogenic, both in frequency and in the range of exchange partners. In this study, we examine the genetic and genomic variation of cultured, naturally co-occurring environmental populations of Halobacteria. Sequence data from multiple loci (~2500bp identified closely related strains belonging to the genera Halorubrum and Haloarcula. Genome fingerprinting using a random priming PCR amplification method to analyze these isolates revealed diverse banding patterns within and across each of the genera and surprisingly even for isolates that are identical at the nucleotide level for five protein coding sequenced loci. This variance in genome structure even between identical multilocus sequence analysis (MLSA haplotypes suggests that accumulation of variation is rapid, perhaps occurring every generation.

  14. Methodology for benzodiazepine receptor binding assays at physiological temperature. Rapid change in equilibrium with falling temperature

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, R.M.

    1986-12-01

    Benzodiazepine receptors of rat cerebellum were assayed with (/sup 3/H)-labeled flunitrazepam at 37/sup 0/C, and assays were terminated by filtration in a cold room according to one of three protocols: keeping each sample at 37 degrees C until ready for filtration, taking the batch of samples (30) into the cold room and filtering sequentially in the order 1-30, and taking the batch of 30 samples into the cold room and filtering sequentially in the order 30-1. the results for each protocol were substantially different from each other, indicating that rapid disruption of equilibrium occurred as the samples cooled in the cold room while waiting to be filtered. Positive or negative cooperativity of binding was apparent, and misleading effects of gamma-aminobutyric acid on the affinity of diazepam were observed, unless each sample was kept at 37/sup 0/C until just prior to filtration.

  15. Rapid spread of complex change: a case study in inpatient palliative care

    Directory of Open Access Journals (Sweden)

    Filipski Marta I

    2009-12-01

    Full Text Available Abstract Background Based on positive findings from a randomized controlled trial, Kaiser Permanente's national executive leadership group set an expectation that all Kaiser Permanente and partner hospitals would implement a consultative model of interdisciplinary, inpatient-based palliative care (IPC. Within one year, the number of IPC consultations program-wide increased almost tenfold from baseline, and the number of teams nearly doubled. We report here results from a qualitative evaluation of the IPC initiative after a year of implementation; our purpose was to understand factors supporting or impeding the rapid and consistent spread of a complex program. Methods Quality improvement study using a case study design and qualitative analysis of in-depth semi-structured interviews with 36 national, regional, and local leaders. Results Compelling evidence of impacts on patient satisfaction and quality of care generated 'pull' among adopters, expressed as a remarkably high degree of conviction about the value of the model. Broad leadership agreement gave rise to sponsorship and support that permeated the organization. A robust social network promoted knowledge exchange and built on an existing network with a strong interest in palliative care. Resource constraints, pre-existing programs of a different model, and ambiguous accountability for implementation impeded spread. Conclusions A complex, hospital-based, interdisciplinary intervention in a large health care organization spread rapidly due to a synergy between organizational 'push' strategies and grassroots-level pull. The combination of push and pull may be especially important when the organizational context or the practice to be spread is complex.

  16. Multimodal imaging documentation of rapid evolution of retinal changes in handheld laser-induced maculopathy.

    Science.gov (United States)

    Dhrami-Gavazi, Elona; Lee, Winston; Balaratnasingam, Chandrakumar; Kayserman, Larisa; Yannuzzi, Lawrence A; Freund, K Bailey

    2015-01-01

    To use multimodal imaging to document the relatively rapid clinical evolution of handheld laser-induced maculopathy (HLIM). To demonstrate that inadvertent ocular injury can result from devices mislabeled with respect to their power specifications. The clinical course of a 17-year-old male who sustained self-inflicted, central macular damage from a 20-25 s direct stare at a red-spectrum, handheld laser pointer ordered from an internet retailer is provided. Retrospective review of multimodal imaging that includes fundus photography, fluorescein angiography, MultiColor reflectance, eye-tracked spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence, and microperimetry is used to describe the evolving clinical manifestations of HLIM in the first 3 months. Curvilinear bands of dense hyperreflectivity extending from the outer retina and following the Henle fibers were seen on SD-OCT immediately after injury. This characteristic appearance had largely resolved by 2 weeks. There was significant non-uniformity in the morphological characteristics of HLIM lesions between autofluorescence and reflectance images. The pattern of lesion evolution was also significantly different between imaging modalities. Analysis of the laser device showed its wavelength to be correctly listed, but the power was found to be 102.5-105 mW, as opposed to the laser -induced maculopathy, this finding can undergo rapid resolution in the span of several days. In the absence of this finding, other multimodal imaging clues and a careful history may aid in recognizing this diagnosis. A greater awareness regarding inaccurate labeling on some of these devices could help reduce the frequency of this preventable entity.

  17. Decadal sea-level variability along the coast of Japan in response to ocean circulation changes

    Science.gov (United States)

    Sasaki, Yoshi N.; Minobe, Shoshiro; Miura, Yuji

    2014-01-01

    Decadal sea-level variability along the coast of Japan and its relation to large-scale ocean circulation changes from 1993 to 2010 was investigated using tide-gauge and satellite-derived sea-level data. A singular value decomposition (SVD) analysis is performed between coastal sea levels of Japan and sea levels in the western North Pacific. The first SVD mode reveals that the northward shifts of the Kuroshio Extension (KE) jet and the Kuroshio southeast of Japan accompany the coastal sea-level rise in the early 2000s and 2010, and their southward shifts accompany the coastal sea-level fall in the late 1990s and the late 2000s. The shifts of the KE jet are induced by westward propagating Rossby wave from the eastern North Pacific, which is concentrated along the KE jet axis as jet-trapped Rossby waves. The resulting sea-level changes along the coast of Japan show a strong spatial contrast. The sea-level fluctuation is quite large along the southeastern coast of Japan that is under the direct influence of the jet-trapped Rossby waves, and also large in the western coast of Japan, probably due to coastal waves that are excited by the incoming Rossby waves, but is small north of the KE jet latitude. Hence, the nature of the wave trapped by the KE jet produces an "active zone" and a "shadow zone" of coastal sea-level variability of Japan. Our results indicate that the correct representation of western boundary currents is necessary for reliable prediction of future coastal sea-level changes.

  18. Exploring the Effects of Climate Variability and Land Use Change on Groundwater-Surface Water Interactions

    Science.gov (United States)

    Duncan, L. L.; Hornberger, G. M.

    2013-12-01

    Locke Island is a 3.5-km long and 375-m wide differentially cemented sand and gravel, mid-channel island located in the Hanford Reach of the Columbia River. Across the eastern channel of the Columbia River from the island is the large Locke Island landslide complex, originating from the White Bluffs. There is evidence that landslides occurred along the White Bluffs in prehistoric times, within the last 11,000 years or so, and evidence of younger landslides, active in the last several hundred years. Irrigation of the land adjacent to the bluffs, and subsequent creation of unlined irrigation wastewater ponds behind the bluffs, is one of the hypotheses concerning the major cause of modern landsliding in this area, which began in the late 1960s. The estimated eight-fold increase in water delivered to the semi-arid area over the course of a decade resulted in an increase in the annual flow through the groundwater system. Similar to land use impacts, changes in the flow through groundwater systems as a result of variations in climate can alter groundwater-surface water exchange processes and connectivity too. We use a vertical two-dimensional finite element model to simulate variably saturated and unsaturated flow in the subsurface porous media along a cross-section of the hillslope-river-island continuum. Our work characterizes the hydraulic gradients and quantifies the outflows at the toe of the landslide and along the banks of the island, in response to creation of ponds behind the bluffs and decadal to multi-decadal changes in patterns of dryness. Understanding the effects of climate variability and land use change on groundwater-surface water exchanges, both separately and in combination, provides insight to the relative importance of these different mechanisms in landslide activity.

  19. Comparing proxy and model estimates of hydroclimate variability and change over the Common Era

    Science.gov (United States)

    Hydro2k Consortium, Pages

    2017-12-01

    Water availability is fundamental to societies and ecosystems, but our understanding of variations in hydroclimate (including extreme events, flooding, and decadal periods of drought) is limited because of a paucity of modern instrumental observations that are distributed unevenly across the globe and only span parts of the 20th and 21st centuries. Such data coverage is insufficient for characterizing hydroclimate and its associated dynamics because of its multidecadal to centennial variability and highly regionalized spatial signature. High-resolution (seasonal to decadal) hydroclimatic proxies that span all or parts of the Common Era (CE) and paleoclimate simulations from climate models are therefore important tools for augmenting our understanding of hydroclimate variability. In particular, the comparison of the two sources of information is critical for addressing the uncertainties and limitations of both while enriching each of their interpretations. We review the principal proxy data available for hydroclimatic reconstructions over the CE and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. A specific review of simulated hydroclimatic changes forced by volcanic events is provided, as is a discussion of expected improvements in estimated radiative forcings, models, and their implementation in the future. Our review of hydroclimatic proxies and last-millennium model simulations is used as the basis for articulating a variety of considerations and best practices for how to perform proxy-model comparisons of CE hydroclimate. This discussion provides a framework for how best to evaluate hydroclimate variability and its associated dynamics using these comparisons and how they can better inform

  20. Rainfall Downscaling Conditional on Upper-air Variables: Assessing Rainfall Statistics in a Changing Climate

    Science.gov (United States)

    Langousis, Andreas; Deidda, Roberto; Marrocu, Marino; Kaleris, Vassilios

    2014-05-01

    Due to its intermittent and highly variable character, and the modeling parameterizations used, precipitation is one of the least well reproduced hydrologic variables by both Global Climate Models (GCMs) and Regional Climate Models (RCMs). This is especially the case at a regional level (where hydrologic risks are assessed) and at small temporal scales (e.g. daily) used to run hydrologic models. In an effort to remedy those shortcomings and assess the effect of climate change on rainfall statistics at hydrologically relevant scales, Langousis and Kaleris (2013) developed a statistical framework for simulation of daily rainfall intensities conditional on upper air variables. The developed downscaling scheme was tested using atmospheric data from the ERA-Interim archive (http://www.ecmwf.int/research/era/do/get/index), and daily rainfall measurements from western Greece, and was proved capable of reproducing several statistical properties of actual rainfall records, at both annual and seasonal levels. This was done solely by conditioning rainfall simulation on a vector of atmospheric predictors, properly selected to reflect the relative influence of upper-air variables on ground-level rainfall statistics. In this study, we apply the developed framework for conditional rainfall simulation using atmospheric data from different GCM/RCM combinations. This is done using atmospheric data from the ENSEMBLES project (http://ensembleseu.metoffice.com), and daily rainfall measurements for an intermediate-sized catchment in Italy; i.e. the Flumendosa catchment. Since GCM/RCM products are suited to reproduce the local climatology in a statistical sense (i.e. in terms of relative frequencies), rather than ensuring a one-to-one temporal correspondence between observed and simulated fields (i.e. as is the case for ERA-interim reanalysis data), we proceed in three steps: a) we use statistical tools to establish a linkage between ERA-Interim upper-air atmospheric forecasts and

  1. Human adaptation responses to a rapidly changing Arctic: A research context for building system resilience

    Science.gov (United States)

    Chapin, T.; Brinkman, T. J.

    2016-12-01

    Although human behavior accounts for more uncertainty in future trajectories in climate change than do biophysical processes, most climate-change research fails to include human actions in research design and implementation. This is well-illustrated in the Arctic. At the global scale, arctic processes strongly influence the strength of biophysical feedbacks between global human emissions and the rate of climate warming. However, most human actions in the arctic have little effect on these feedbacks, so research can contribute most effectively to reduction in arctic warming through improved understanding of the strength of arctic-global biophysical feedbacks, as in NASA's ABoVE program, and its effective communication to policy makers and the public. In contrast, at the local to regional scale within the arctic, human actions may influence the ecological and societal consequences of arctic warming, so research benefits from active stakeholder engagement in research design and implementation. Human communities and other stakeholders (government and NGOs) respond heterogeneously to socioeconomic and environmental change, so research that documents the range of historical and current adaptive responses to change provides insights on the resilience (flexibility of future options) of social-ecological processes in the arctic. Alaskan communities have attempted a range of adaptive responses to coastal erosion (e.g., seasonal migration, protection in place, relocation), wildfire (fire suppression to use of fire to manage wildlife habitat or landscape heterogeneity), declining sea ice (e.g., new hunting technology, sea ice observations and predictions), and changes in wildlife and fish availability (e.g., switch to harvest of alternative species, harvest times, or harvest locations). Research that draws on both traditional and western knowledge facilitates adaptation and predictions of the likely societal consequences of climate change in the Arctic. Effective inclusion of

  2. Rapid transformation of two libraries using Kotter’s Eight Steps of Change

    Science.gov (United States)

    Wheeler, Terrie R.; Holmes, Kristi L.

    2017-01-01

    Background Two new directors were each charged by their institutions to catalyze transformational change in their libraries and to develop dynamic and evolving information ecosystems ready for the information challenges of the future. The directors approached this transformational change using a strategic, forward-looking approach. Results This paper presents examples of actions that served as catalysts for change at the two libraries using Kotter’s Eight Steps of Change as a framework. Small and large changes are critical for successfully transforming library services, resources, and personnel. Conclusions Libraries are faced with incredible pressure to adapt to meet emerging and intensifying information needs on today’s academic medical campuses. These pressures offer an opportunity for libraries to accelerate their evolution at the micro and macro levels. This commentary reports the expansion of new services and areas of support, enhancement of professional visibility of the libraries on their campuses, and overall, a more positive and productive environment at the respective institutions. PMID:28670217

  3. Variability and quasi-decadal changes in the methane budget over the period 2000–2012

    Directory of Open Access Journals (Sweden)

    M. Saunois

    2017-09-01

    Full Text Available Following the recent Global Carbon Project (GCP synthesis of the decadal methane (CH4 budget over 2000–2012 (Saunois et al., 2016, we analyse here the same dataset with a focus on quasi-decadal and inter-annual variability in CH4 emissions. The GCP dataset integrates results from top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework and bottom-up models (including process-based models for estimating land surface emissions and atmospheric chemistry, inventories of anthropogenic emissions, and data-driven approaches. The annual global methane emissions from top-down studies, which by construction match the observed methane growth rate within their uncertainties, all show an increase in total methane emissions over the period 2000–2012, but this increase is not linear over the 13 years. Despite differences between individual studies, the mean emission anomaly of the top-down ensemble shows no significant trend in total methane emissions over the period 2000–2006, during the plateau of atmospheric methane mole fractions, and also over the period 2008–2012, during the renewed atmospheric methane increase. However, the top-down ensemble mean produces an emission shift between 2006 and 2008, leading to 22 [16–32] Tg CH4 yr−1 higher methane emissions over the period 2008–2012 compared to 2002–2006. This emission increase mostly originated from the tropics, with a smaller contribution from mid-latitudes and no significant change from boreal regions. The regional contributions remain uncertain in top-down studies. Tropical South America and South and East Asia seem to contribute the most to the emission increase in the tropics. However, these two regions have only limited atmospheric measurements and remain therefore poorly constrained. The sectorial partitioning of this emission increase between the periods 2002–2006 and 2008–2012 differs from one atmospheric inversion study to

  4. Variability and quasi-decadal changes in the methane budget over the period 2000-2012

    Science.gov (United States)

    Saunois, Marielle; Bousquet, Philippe; Poulter, Ben; Peregon, Anna; Ciais, Philippe; Canadell, Josep G.; Dlugokencky, Edward J.; Etiope, Giuseppe; Bastviken, David; Houweling, Sander; Janssens-Maenhout, Greet; Tubiello, Francesco N.; Castaldi, Simona; Jackson, Robert B.; Alexe, Mihai; Arora, Vivek K.; Beerling, David J.; Bergamaschi, Peter; Blake, Donald R.; Brailsford, Gordon; Bruhwiler, Lori; Crevoisier, Cyril; Crill, Patrick; Covey, Kristofer; Frankenberg, Christian; Gedney, Nicola; Höglund-Isaksson, Lena; Ishizawa, Misa; Ito, Akihiko; Joos, Fortunat; Kim, Heon-Sook; Kleinen, Thomas; Krummel, Paul; Lamarque, Jean-François; Langenfelds, Ray; Locatelli, Robin; Machida, Toshinobu; Maksyutov, Shamil; Melton, Joe R.; Morino, Isamu; Naik, Vaishali; O'Doherty, Simon; Parmentier, Frans-Jan W.; Patra, Prabir K.; Peng, Changhui; Peng, Shushi; Peters, Glen P.; Pison, Isabelle; Prinn, Ronald; Ramonet, Michel; Riley, William J.; Saito, Makoto; Santini, Monia; Schroeder, Ronny; Simpson, Isobel J.; Spahni, Renato; Takizawa, Atsushi; Thornton, Brett F.; Tian, Hanqin; Tohjima, Yasunori; Viovy, Nicolas; Voulgarakis, Apostolos; Weiss, Ray; Wilton, David J.; Wiltshire, Andy; Worthy, Doug; Wunch, Debra; Xu, Xiyan; Yoshida, Yukio; Zhang, Bowen; Zhang, Zhen; Zhu, Qiuan

    2017-09-01

    Following the recent Global Carbon Project (GCP) synthesis of the decadal methane (CH4) budget over 2000-2012 (Saunois et al., 2016), we analyse here the same dataset with a focus on quasi-decadal and inter-annual variability in CH4 emissions. The GCP dataset integrates results from top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models (including process-based models for estimating land surface emissions and atmospheric chemistry), inventories of anthropogenic emissions, and data-driven approaches. The annual global methane emissions from top-down studies, which by construction match the observed methane growth rate within their uncertainties, all show an increase in total methane emissions over the period 2000-2012, but this increase is not linear over the 13 years. Despite differences between individual studies, the mean emission anomaly of the top-down ensemble shows no significant trend in total methane emissions over the period 2000-2006, during the plateau of atmospheric methane mole fractions, and also over the period 2008-2012, during the renewed atmospheric methane increase. However, the top-down ensemble mean produces an emission shift between 2006 and 2008, leading to 22 [16-32] Tg CH4 yr-1 higher methane emissions over the period 2008-2012 compared to 2002-2006. This emission increase mostly originated from the tropics, with a smaller contribution from mid-latitudes and no significant change from boreal regions. The regional contributions remain uncertain in top-down studies. Tropical South America and South and East Asia seem to contribute the most to the emission increase in the tropics. However, these two regions have only limited atmospheric measurements and remain therefore poorly constrained. The sectorial partitioning of this emission increase between the periods 2002-2006 and 2008-2012 differs from one atmospheric inversion study to another. However, all top-down studies

  5. Implications of rapid environmental change for polar bear behavior and sociality

    Science.gov (United States)

    Atwood, Todd C.

    2017-01-01

    Historically, the Arctic sea ice has functioned as a structural barrier that has limited the nature and extent of interactions between humans and polar bears (Ursus maritimus). However, declining sea ice extent, brought about by global climate change, is increasing the potential for human-polar bear interactions. Loss of sea ice habitat is driving changes to both human and polar bear behavior—it is facilitating increases in human activities (e.g., offshore oil and gas exploration and extraction, trans-Arctic shipping, recreation), while also causing the displacement of bears from preferred foraging habitat (i.e., sea ice over biologically productive shallow) to land in some portions of their range. The end result of these changes is that polar bears are spending greater amounts of time in close proximity to people. Coexistence between humans and polar bears will require imposing mechanisms to manage further development, as well as mitigation strategies that reduce the burden to local communities.

  6. Impacts of Climate Variability and Change on (Marine) Animals: Physiological Underpinnings and Evolutionary Consequences.

    Science.gov (United States)

    Pörtner, Hans O; Gutt, Julian

    2016-07-01

    variability throughout earth's history have influenced animal evolution and co-defined their success or failure from a bio-energetic point of view. Deepening such understanding may further reduce uncertainty about projected impacts of anthropogenic climate variability and change on the distribution, productivity and last not least, survival of aquatic and terrestrial species. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  7. Unbounded boundaries and shifting baselines: Estuaries and coastal seas in a rapidly changing world

    Science.gov (United States)

    Little, S.; Spencer, K. L.; Schuttelaars, H. M.; Millward, G. E.; Elliott, M.

    2017-11-01

    This Special Issue of Estuarine, Coastal and Shelf Science presents contributions from ECSA 55; an international symposium organised by the Estuarine and Coastal Sciences Association (ECSA) and Elsevier on the broad theme of estuaries and coastal seas in times of intense change. The objectives of the SI are to synthesise, hypothesise and illustrate the impacts of global change on estuaries and coastal seas through learning lessons from the past, discussing the current and forecasting for the future. It is highlighted here that establishing impacts and assigning cause to the many pressures of global change is and will continue to be a formidable challenge in estuaries and coastal seas, due in part to: (1) their complexity and unbounded nature; (2) difficulties distinguishing between human-induced changes and natural variations and; (3) multiple pressures and effects. The contributing authors have explored a number of these issues over a range of disciplines. The complexity and connectivity of estuaries and coastal seas have been investigated through studies of physicochemical and ecological components, whilst the human imprint on the environment has been identified through a series of predictive, contemporary, historical and palaeo approaches. The impact of human activities has been shown to occur over a range of spatial and temporal scales, requiring the development of integrated management approaches. These 30 articles provide an important contribution to our understanding and assessment of the impacts of global change. The authors highlight methods for essential management/mitigation of the consequences of global change and provide a set of directions, ideas and observations for future work. These include the need to consider: (1) the cumulative, synergistic and antagonistic effects of multiple pressures; (2) the importance of unbounded boundaries and connectivity across the aquatic continuum; (3) the value of combining cross-disciplinary palaeo, contemporary and

  8. A rapid change in the low energy cut-off of Scorpius X-1

    Science.gov (United States)

    Moore, W. E.; Cordova, F.; Garmire, G. P.

    1974-01-01

    Sco X-1 was observed on June 10, 1972 near 04 hr 33 min U.T. simultaneously in the optical (B) the soft X-ray (0.1 to 2.4 keV) and the X-ray (1.5 to 20 keV) bands of the spectrum. It is believed that a change of short duration in the absorbing medium associated with Sco X-1 was observed. The medium attenuating the low energy X-ray flux from Sco X-1 has apparently changed by more than 40% on a time scale of less than 45 sec.

  9. Rapid change of atmosphere on the Hadean Earth: Beyond Habitable Trinity on a tightrope

    Science.gov (United States)

    Arai, T.; Maruyama, S.

    2014-12-01

    Surface environment of Hadean Earth is a key to bear life on the Earth. All of previous works assumed that high pCO2 has been decreased to a few bars in the first a few hundreds millions of years (e.g., Zhanle et al., 2011). However, this process is not easy because of material and process barriers as shown below. Four barriers are present. First, the ultra-acidic pH (<0.1) of 4.4Ga ocean prevented the precipitation of carbonates at mid-oceanic ridge through water-rock interaction after the birth of primordial ocean driven by plate tectonics or pseudo-plate tectonics system. To overcome this barrier, primordial (anorthosite + KREEP) continents must have been above sea-level to increase pH rapidly through hydrological process. Second, major cap rocks on the Hadean oceanic crust must have been komatiite with minor basaltic rocks to precipitate carbonates through water-rock interaction and transport them into mantle through subduction at higher than the intermediate P/T geotherm on the Benioff plane. If not, carbonate minerals are all decarbonated at shallower depths than the Moho plane. Komatiite production depends on mantle potential temperature which must have been rapidly decreased to yield only Fe-enriched MORB by 3.8Ga. Third, the primordial continents composed of anorthosite with subordinate amounts of KREEP basalts must have been annihilated by 4.0Ga to alter pH to be possible to precipitate carbonates by hydrothermal process. The value of pCO2 must have been decreased down to a few bars from c.a. 50 bars at TSI (total surface irradiance) = 75% under the restricted time limit. If failed, the Earth must have been Venus state which is impossible to bear life on the planet. Fourth is the role of tectonic erosion to destroy and transport the primordial continent of anorthosite into deep mantle by subduction. Anorthosite + KREEP was the mother's milk grow life on the Earth, but disappeared by 4.0Ga or even earlier, but alternatively granites were formed and

  10. Impacts of climate change and variability on transportation systems and infrastructure : Gulf Coast study, phase 2 : task 2 : climate variability and change in Mobile, Alabama.

    Science.gov (United States)

    2012-09-01

    Despite increasing confidence in global climate change projections in recent years, projections of : climate effects at local scales remains scarce. Location-specific risks to transportation systems : imposed by changes in climate are not yet well kn...

  11. Meditation-induced changes in high-frequency heart rate variability predict smoking outcomes

    Directory of Open Access Journals (Sweden)

    Daniel J. Libby

    2012-03-01

    Full Text Available Background: High-frequency heart rate variability (HF-HRV is a measure of parasympathetic nervous system output that has been associated with enhanced self-regulation. Low resting levels of HF-HRV are associated with nicotine dependence and blunted stress-related changes in HF-HRV are associated with decreased ability to resist smoking. Meditation has been shown to increase HF-HRV. However, it is unknown whether tonic levels of HF-HRV or acute changes in HF-HRV during meditation predict treatment responses in addictive behaviors such as smoking cessation. Purpose: To investigate the relationship between HF-HRV and subsequent smoking outcomes. Methods: HF-HRV during resting baseline and during mindfulness meditation was measured within two weeks of completing a 4-week smoking cessation intervention in a sample of 31 community participants. Self-report measures of smoking were obtained at a follow up 17-weeks after the initiation of treatment. Results: Regression analyses indicated that individuals exhibiting acute increases in HF-HRV from resting baseline to meditation smoked fewer cigarettes at follow-up than those who exhibited acute decreases in HF-HRV (b=-4.94, p=.009. Conclusion: Acute changes in HF-HRV in response to meditation may be a useful tool to predict smoking cessation treatment response.

  12. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

    Directory of Open Access Journals (Sweden)

    Lourdes Gallego-Calvo

    2015-12-01

    Full Text Available Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001. No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05. After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05. These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer.

  13. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

    Energy Technology Data Exchange (ETDEWEB)

    Gallego-Calvo, L.; Gatica, M.C.; Santiago-Moreno, J.; Guzmán, J.L.; Zarazaga, L.

    2015-07-01

    Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001). No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05). After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05). These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer. (Author)

  14. Corals at the Flower Garden Banks: Monitors of Environmental Change and North American Climate Variability

    Science.gov (United States)

    Wagner, A. J.; Slowey, N. C.

    2007-12-01

    The Pacific/North American (PNA) pattern is a dominant atmospheric pattern of climate variability in the extratropical Northern Hemisphere and strongly influences the winter climate of the southeast United States. The instrumental record used to characterize the PNA pattern does not exist prior to the mid-1940s. However, information about past variability in the PNA pattern is preserved in the skeletons of long-lived corals at the reefs of the Flower Garden Banks National Marine Sanctuary (NMS). The Flower Garden Banks NMS is located approximately 180 km south of the Texas/Louisiana border in the Gulf of Mexico and is the northernmost hermatypic reef on the United States continental shelf. It has previously been shown that linear coral extension rates at the Flower Garden Banks are highly correlated with winter air and sea surface temperatures. In addition, average winter temperatures in the southeastern United States are negatively correlated with the phase of the PNA pattern. During a positive phase of the PNA pattern, the southeast US experiences stronger and more frequent winter storms while a negative phase of the PNA pattern brings milder winters to the region. Thus, past coral extension rates at the Flower Garden Banks provide a means to reconstruct the history of temporal variations in the PNA pattern. We collected several long cores of skeletal material from long-lived Montastrea faveolata and Siderastrea siderea coral heads from the Flower Garden Banks NMS. Annual extension rates have been determined based on X- radiographic analysis of high/low density growth bands and are used to characterize interdecadal variability associated with changes in the PNA pattern. In addition, the presence of winter stress bands due to below average water temperatures indicate winters with more severe and/or frequent storms. Analysis of these results will contribute directly to our understanding of the temporal character of interannual and interdecadal variations of North

  15. Morning versus afternoon gymnastic time and diurnal and seasonal changes in psychophysiological variables of school children.

    Science.gov (United States)

    Huguet, G; Touitou, Y; Reinberg, A

    1997-07-01

    The aims of this study were to document time-related (morning versus afternoon) effects of physical activities (gymnastics) on a set of physiological and psychological variables in school children, including diurnal changes. For the study, 61 boys and 69 girls, 6 to 11 years of age, volunteered. They were considered healthy according to routine clinical criteria. They were synchronized with diurnal activity from around 07:00 to 21:00 and nocturnal rest, time of year being taken into account. Tests were performed at school during 4 weeks of 4.5 days of school at fixed clock hours: 09:00, 11:00, 14:00, and 16:00. Gym time was randomized with regard to week order and season. Four different classes (39 boys and 38 girls) were involved in psychophysiological tests, and two different classes (22 boys and 31 girls) collected saliva samples for morning free cortisol determination. Both t-test and three-factor analysis of variance (ANOVA) were used for statistical analyses. Better performances were obtained in June than in mid-winter with reference to letter cancellation and random number addition tests. As a group phenomenon, morning (09:00 to 10:00) versus afternoon (14:00 to 15:00) gym was not an influential condition with regard to sleep duration, oral temperature, self-rated fatigue and drowsiness, letter cancellation, addition tests, or salivary cortisol. However, gym-time-related differences were observed in classes of younger subjects (e.g., 6-7 years) with regard to self-rated fatigue and the letter cancellation test. Such variability among subgroups suggests that interindividual differences are likely to exist in younger children with regard to manipulation of environmental factors. In addition, gym itself (without gym time consideration) may be an influential factor with regard to diurnal patterns of some variables (e.g., the letter cancellation test).

  16. Rapid evolution of phenology during range expansion with recent climate change

    NARCIS (Netherlands)

    Lustenhouwer, N.; Wilschut, R.A.; Williams, J.L.; van der Putten, W.H.; Levine, J.M.

    2017-01-01

    Although climate warming is expected to make habitat beyond species’ current cold range edge suitable for future colonization, this new habitat may present an array of biotic or abiotic conditions not experienced within the current range. Species’ ability to shift their range with climate change may

  17. Rapid species responses to changes in climate require stringent climate protection targets

    NARCIS (Netherlands)

    Vliet, van A.J.H.; Leemans, R.

    2006-01-01

    The Avoiding Dangerous Climate Change book consolidates the scientific findings of the Exeter conference and gives an account of the most recent developments on critical thresholds and key vulnerabilities of the climate system, impacts on human and natural systems, emission pathways and

  18. Extended Services in Schools: Developing Resources to Prepare Student Teachers for a Rapidly Changing Working Environment

    Science.gov (United States)

    Griffiths, Sue; Smith, Andy

    2011-01-01

    The role of schools in providing extended services to their communities continues to undergo change and development. This has raised issues regarding the training of student teachers who are increasingly likely to take up appointments in schools offering extended services. This research project investigated the development of resources to prepare…

  19. A replicated climate change field experiment reveals rapid evolutionary response in an ecologically important soil invertebrate

    DEFF Research Database (Denmark)

    Bataillon, Thomas; Galtier, Nicolas; Bernard, Aurelien

    2016-01-01

    to climate change in a common annelid worm using a controlled replicated experiment where climatic conditions were manipulated in a natural setting. Analyzing the transcribed genome of 15 local populations, we found that about 12% of the genetic polymorphisms exhibit differences in allele frequencies...

  20. Evolution and behavioural responses to human-induced rapid environmental change

    Science.gov (United States)

    Sih, Andrew; Ferrari, Maud C O; Harris, David J

    2011-01-01

    Almost all organisms live in environments that have been altered, to some degree, by human activities. Because behaviour mediates interactions between an individual and its environment, the ability of organisms to behave appropriately under these new conditions is crucial for determining their immediate success or failure in these modified environments. While hundreds of species are suffering dramatically from these environmental changes, others, such as urbanized and pest species, are doing better than ever. Our goal is to provide insights into explaining such variation. We first summarize the responses of some species to novel situations, including novel risks and resources, habitat loss/fragmentation, pollutants and climate change. Using a sensory ecology approach, we present a mechanistic framework for predicting variation in behavioural responses to environmental change, drawing from models of decision-making processes and an understanding of the selective background against which they evolved. Where immediate behavioural responses are inadequate, learning or evolutionary adaptation may prove useful, although these mechanisms are also constrained by evolutionary history. Although predicting the responses of species to environmental change is difficult, we highlight the need for a better understanding of the role of evolutionary history in shaping individuals’ responses to their environment and provide suggestion for future work. PMID:25567979

  1. Challenge and Response, Strategies for Survival in a Rapidly Changing Forest Products Industry

    Science.gov (United States)

    Al Schuler; Craig Adair; Paul Winistorfer

    2005-01-01

    The U.S. has long been the world's largest market for wood and wood products, fueled by its demand for wood-frame housing. But forest product markets are changing, both in terns of where the products originate (domestically or abroad),and what products are being produced and consumed.

  2. Role of Western Hemisphere Warm Pool in Rapid Climate Changes over the Western North Pacific

    Science.gov (United States)

    Kug, Jong-Seong; Park, Jae-Heung; An, Soon-Il

    2017-04-01

    Oceanic states over the western North Pacific (WNP), which is surrounded by heavily populated countries, are closely tied to the lives of the people in East Asia in regards to both climate and socioeconomics. As global warming continues, remarkable increases in sea surface temperature (SST) and sea surface height (SSH) have been observed in the WNP in recent decades. Here, we show that the SST increase in the western hemisphere warm pool (WHWP), which is the second largest warm pool on the globe, has contributed considerably to the rapid surface warming and sea level rise in the WNP via its remote teleconnection along the Pacific Intertropical Convergence Zone (ITCZ). State-of-the-art climate models strongly support the role of the WHWP not only on interannual time sales but also in long-term climate projections. We expect that understanding the processes initiated by the WHWP-SST could permit better forecasts of western North Pacific climate and the further development of the socioeconomics of East Asia.

  3. Recruitment success and growth variability of mugilids in a West African estuary impacted by climate change

    Science.gov (United States)

    Trape, S.; Durand, J.-D.; Vigliola, L.; Panfili, J.

    2017-11-01

    With the persistence of a drought since the late 1960s, some West African estuaries became permanently reversed in term of salinity gradient and hypersaline waters are present in their upstream part (salinity >60). To understand the mechanisms regulating fish recruitment intensity in these estuaries and evaluate the consequences of freshwater shortages on juvenile habitat quality, a growth study was conducted in the Saloum hypersaline estuary (Senegal). The Mugilidae fish family, highly representative of estuarine environments, was targeted and several species sampled (Chelon dumerili, Mugil bananensis and M. cf. curema sp. M). Juveniles were sampled monthly all the year round in three areas of the estuary exhibiting strongly contrasted habitat conditions. Otolith sections were used to estimate the ages, reconstruct growth trajectories, estimate the duration of the oceanic larval phase, and evaluate juvenile growth variability along the salinity gradient. Analyses revealed that the temporal recruitment variability of C. dumerili, with 2 annual cohorts, was not mainly induced by growth-selection mechanisms, but probably more by predation pressures. Juveniles exhibited significantly faster growth rates in the lower salinity suggesting that benthic food availability was a strong factor controlling habitat quality of early juveniles. Salinity had also a clear impact when reducing the growth in hypersaline conditions and/or selecting slower growing individuals. Moderate freshwater inputs positively affected the nursery function of the estuary for mugilids by enhancing the productivity of the first trophic levels. In a long term, the global change could have an impact of the mugilid fishery and its management.

  4. Age of oil palm plantations causes a strong change in surface biophysical variables

    Science.gov (United States)

    Sabajo, Clifton; le Maire, Guerric; Knohl, Alexander

    2016-04-01

    Over the last decades, Indonesia has experienced dramatic land transformations with an expansion of oil palm plantations at the expense of tropical forests. As vegetation is a modifier of the climate near the ground these large-scale land transformations are expected to have major impacts on the surface biophysical variables i.e. surface temperature, albedo, and vegetation indices, e.g. the NDVI. Remote sensing data are needed to assess such changes at regional scale. We used 2 Landsat images from Jambi Province in Sumatra/Indonesia covering a chronosequence of oil palm plantations to study the 20 - 25 years life cycle of oil palm plantations and its relation with biophysical variables. Our results show large differences between the surface temperature of young oil palm plantations and forest (up to 9.5 ± 1.5 °C) indicating that the surface temperature is raised substantially after the establishment of oil palm plantations following the removal of forests. During the oil palm plantation lifecycle the surface temperature differences gradually decreases and approaches zero around an oil palm plantation age of 10 years. Similarly, NDVI increases and the albedo decreases approaching typical values of forests. Our results show that in order to assess the full climate effects of oil palm expansion biophysical processes play an important role and the full life cycle of oil palm plantations need to be considered.

  5. Ocean heat content variability and change in an ensemble of ocean reanalyses

    Science.gov (United States)

    Palmer, M. D.; Roberts, C. D.; Balmaseda, M.; Chang, Y.-S.; Chepurin, G.; Ferry, N.; Fujii, Y.; Good, S. A.; Guinehut, S.; Haines, K.; Hernandez, F.; Köhl, A.; Lee, T.; Martin, M. J.; Masina, S.; Masuda, S.; Peterson, K. A.; Storto, A.; Toyoda, T.; Valdivieso, M.; Vernieres, G.; Wang, O.; Xue, Y.

    2017-08-01

    Accurate knowledge of the location and magnitude of ocean heat content (OHC) variability and change is essential for understanding the processes that govern decadal variations in surface temperature, quantifying changes in the planetary energy budget, and developing constraints on the transient climate response to external forcings. We present an overview of the temporal and spatial characteristics of OHC variability and change as represented by an ensemble of dynamical and statistical ocean reanalyses (ORAs). Spatial maps of the 0-300 m layer show large regions of the Pacific and Indian Oceans where the interannual variability of the ensemble mean exceeds ensemble spread, indicating that OHC variations are well-constrained by the available observations over the period 1993-2009. At deeper levels, the ORAs are less well-constrained by observations with the largest differences across the ensemble mostly associated with areas of high eddy kinetic energy, such as the Southern Ocean and boundary current regions. Spatial patterns of OHC change for the period 1997-2009 show good agreement in the upper 300 m and are characterized by a strong dipole pattern in the Pacific Ocean. There is less agreement in the patterns of change at deeper levels, potentially linked to differences in the representation of ocean dynamics, such as water mass formation processes. However, the Atlantic and Southern Oceans are regions in which many ORAs show widespread warming below 700 m over the period 1997-2009. Annual time series of global and hemispheric OHC change for 0-700 m show the largest spread for the data sparse Southern Hemisphere and a number of ORAs seem to be subject to large initialization `shock' over the first few years. In agreement with previous studies, a number of ORAs exhibit enhanced ocean heat uptake below 300 and 700 m during the mid-1990s or early 2000s. The ORA ensemble mean (±1 standard deviation) of rolling 5-year trends in full-depth OHC shows a relatively steady

  6. Social integration prospectively predicts changes in heart rate variability among individuals undergoing migration stress.

    Science.gov (United States)

    Gouin, Jean-Philippe; Zhou, Biru; Fitzpatrick, Stephanie

    2015-04-01

    Poor social integration increases risk for poor health. The psychobiological pathways underlying this effect are not well-understood. This study utilized a migration stress model to prospectively investigate the impact of social integration on change in high-frequency heart rate variability (HF-HRV), a marker of autonomic functioning. Sixty new international students were recruited shortly after their arrival in the host country and assessed 2 and 5 months later. At each assessment period, participants provided information on social integration and loneliness and had their resting HF-HRV evaluated. There was an overall decrease in HF-HRV over time. The magnitude of the within-person and between-person effects of social integration on HRV increased over time, such that greater social integration was associated with higher HF-HRV at later follow-ups. These results suggest that altered autonomic functioning might represent a key pathway linking social integration to health outcomes.

  7. Dynamic Changes in Heart Rate Variability and Nasal Airflow Resistance during Nasal Allergen Provocation Test

    Directory of Open Access Journals (Sweden)

    Tiina M. Seppänen

    2016-01-01

    Full Text Available Allergic rhinitis is a major chronic respiratory disease and an immunoneuronal disorder. We aimed at providing further knowledge on the function of the neural system in nasal allergic reaction. Here, a method to assess simultaneously the nasal airflow resistance and the underlying function of autonomic nervous system (ANS is presented and used during the nasal provocation of allergic and nonallergic subjects. Continuous nasal airflow resistance and spectral heart rate variability parameters show in detail the timing and intensity differences in subjects’ reactions. After the provocation, the nasal airflow resistance of allergic subjects showed a positive trend, whereas LF/HF (Low Frequency/High Frequency ratio and LF power showed a negative trend. This could imply a gradual sympathetic withdrawal in allergic subjects after the allergen provocation. The groups differed significantly by these physiological descriptors. The proposed method opens entirely new opportunities to research accurately concomitant changes in nasal breathing function and ANS.

  8. Climate variability and change on the Mongolian Plateau: historical variation and future predictions

    DEFF Research Database (Denmark)

    Jiang, Liguang; Yao, Zhijun; Huang, He Qing

    2016-01-01

    .5, respectively, and the increases in mean temperature are 3.5 and 7.1 degrees C. The spatial patterns are more complicated. These results suggest that the Mongolian Plateau will experience significant climate warming and accompanying increased precipitation. Adaptation strategies are needed to improve...... and maximum temperature were 1.90, 1.78 and 1.59 degrees C, respectively, showing an asymmetric warming process. The winter minimum temperature showed the largest warming trend, at a rate of 0.36 degrees C decade(-1) (p Spatial heterogeneity was apparent for both precipitation and temperature......, although these variables exhibited different patterns. (2) During the coming century, increases in precipitation and temperature can be seen under RCP4.5 and RCP8.5, with pronounced larger amplitude changes under RCP8.5. By 2100, the increases in precipitation are 13.3 and 16.1% for RCP4.5 and RCP8...

  9. Status and changes in key meteorological variables at the CONECOFOR plots, 1996 - 2005

    Directory of Open Access Journals (Sweden)

    Tiziana Amoriello

    2013-11-01

    Full Text Available In this paper, variability of precipitation, temperatures and temperature stress indexes of permanent monitoring plots (PMPs of Italian CONECOFOR network are analyzed. The study is carried out in 16 Open Field areas over the period 1996-2005. For four areas among these (BOL1, EMI1, VAL1, VEN1 longer time series are considered. An eventual trend in time series is analysed using the Mann- Kendall test, applied to annual and seasonal values, and using the additive stochastic model to separate the seasonal variation, despite the limited number of available data. Both methods do not show clear temperature or precipitation trends on long-term period. Changes in annual climatic parameters for different areas may be related to fluctuations on short-term period.

  10. Contributions of Climate Variability and Human Activities to Runoff Changes in the Upper Catchment of the Red River Basin, China

    Directory of Open Access Journals (Sweden)

    Yungang Li

    2016-09-01

    Full Text Available Quantifying the effects of climate variability and human activities on runoff changes will contribute to regional water resource planning and management. This study aims to separate the effects of climate variability and human activities on runoff changes in the upper catchment of the Red River Basin in China. The Mann–Kendall test and Pettitt’s test methods were applied to identify the trends and change points of the hydro-meteorological variables. The hydrological sensitivity, climate elasticity and hydrological simulation methods were adopted to estimate the contributions of climate variability and human activities to runoff changes. Results showed that annual runoff significantly decreased by 1.57 mm/year during the period of 1961–2012. A change point in annual runoff coefficient occurred in 2002. Accordingly, the annual runoff series were divided into the baseline period (1961–2002 and the impacted period (2003–2012. Mean annual runoff of the impacted period decreased by 29.13% compared with the baseline period. Similar estimates of the contributions of climate variability and human activities were obtained by the three different methods. Climate variability was estimated to be responsible for 69%–71% of the reduction in annual runoff, and human activities accounted for 29%–31%. Climate variability was the main driving factor for runoff decrease in the catchment.

  11. Decadal variability in coastal phytoplankton community composition in a changing West Antarctic Peninsula

    Science.gov (United States)

    Schofield, Oscar; Saba, Grace; Coleman, Kaycee; Carvalho, Filipa; Couto, Nicole; Ducklow, Hugh; Finkel, Zoe; Irwin, Andrew; Kahl, Alex; Miles, Travis; Montes-Hugo, Martin; Stammerjohn, Sharon; Waite, Nicole

    2017-06-01

    The coastal waters of the West Antarctic Peninsula (WAP) are associated with large phytoplankton blooms dominated by large (>20 μm) diatoms however, nanoplankton (Research program at the United States Palmer Research Station, we assessed long-term patterns and stability in the coastal phytoplankton communities in the WAP. There was significant interannual variability in the integrated water column chlorophyll a (chl-a) concentrations, which varied by a factor of 5 over the 20-year time series. There has been a significant positive increase in the seasonally integrated concentration of chl-a over the time series. The dominant phytoplankton were diatoms, with cryptophytes the second most abundant. Mixed flagellates also constituted a significant fraction of the chl-a but showed less interannual variability than diatoms and cryophytes. Peak phytoplankton biomass was observed in summer months, when monthly averaged wind speed was lower than in the fall and autumn. Cryptophytes were most abundant during the summer months (December-January) after the seasonal retreat of sea ice. While diatoms were observed over the full range of observed salinities 32-34.5) as well as over the full range of in situ temperatures (-1.5 to 2.5 °C), the cryptophyte populations were observed in locations with lower salinity 32.5-33.75) and colder water (-1 to 1 °C). Environmental factors that favored a shallower seasonal mixed layer resulted in larger diatom blooms compared to the other phytoplankton taxa. During summer with lower phytoplankton biomass, a larger proportion of the chlorophyll a was associated with cryptophytes. These results demonstrate that continued temperature changes along the West Antarctic Peninsula will result in changes in phytoplankton concentration and community composition, which has significant ramifications for the food web.

  12. Seasonal changes, spatial variability and origin of suspended organic matter in Hornsund, Spitsbergen

    Science.gov (United States)

    Apolinarska, Karina; Szczuciński, Witold; Moskalik, Mateusz; Dominiczak, Aleksander

    2017-04-01

    Carbon stable isotope composition (δ13C) of suspended organic matter (SOM) was investigated to recognize temporal and spatial variability, as well as sources of particulate carbon delivered to the sediments of Hornsund fjord, Spitsbergen. Sampling was carried out between May 2015, when most of the investigated area was covered with sea-ice, and late August 2015. Samples were taken from a number of sites in central part of Hornsund, Burgerbukta, Samarinvegen and Brepolen bay in the innermost part of the fjord. One litre water volume, sampled from a range of depths between the water surface and 100 m, was filtered using GFF filters. δ13C values of the SOM were measured after acid treatment of the filters to remove carbonates. δ13C values of SOM varied both temporarily and spatially reflecting the variable sources of organic carbon, namely the marine production in situ, fresh marine organic carbon brought from the shelf with currents and "old" carbon delivered from land. The samples were most 13C-enriched (-22.4‰) in June, at the time of an intensive primary productivity within the fjord. Later, during the warm season, with the more intensive glaciers melting and thus supply of the suspended sediment load containing the old terrigenous carbon, δ13C values of SOM decreased in all the localities studied towards the carbon isotope values of the local terrestrial end-member, i.e., δ13C values of the old organic carbon in the bedrock. Change in δ13C values of SOM was also observed with increasing distance from glaciers, e.g. in front of the Samarinbreen and reflect changes in the intensity of primary production and supply of the old carbon. The study was supported from National Science Center grant No. 2013/10/E/ST10/00166.

  13. Food Security Through the Eyes of AVHRR: Changes and Variability of African Food Production

    Science.gov (United States)

    Vrieling, A.; de Beurs, K. M.; Brown, M. E.

    2008-12-01

    Food security is defined by FAO as a situation that exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life. Despite globalization and food trade, access to food remains a major problem for an important part of Africa's population. As a contribution to the food security analysis we identify at a coarse scale where trends and high interannual variability of food production occur within Africa. We use the 8-km resolution AVHRR NDVI 15-day composites of the GIMMS group (1981-2006). Two methods were applied to extract phenology indicators from the dataset. The indicators are start of season, length of season, time of maximum NDVI, maximum NDVI, and cumulated NDVI over the season. To focus the analysis on food production we spatially aggregate the annual indicators at sub-national level using a general crop mask. Persistent changes during the 26-year period were assessed using trend analysis on the yearly aggregated indicators. These trends may indicate changes in production, and consequent potential increases of food insecurity. We evaluate then where strong interannual variability of phenology indicators occurs. This relates to regular shortages of food availability. For Africa, field information on phenology or accurate time series of production figures at the sub-national scale are scarce. Validating the outcome of the AVHRR analysis is consequently difficult. We propose to use crop-specific national FAOSTAT yield statistics. For this purpose, we aggregate phenology outputs per country using specific masks for the major staple food crops. Although data quality and scale issues influence results, for several countries and crops significant positive correlations between indicators and crop production exist. We conclude that AVHRR-derived phenology information can provide useful inputs to food security analysis.

  14. Recent changes in aquatic biota in subarctic Fennoscandia - the role of global and local environmental variables

    Science.gov (United States)

    Weckström, Jan; Leppänen, Jaakko; Sorvari, Sanna; Kaukolehto, Marjut; Weckström, Kaarina; Korhola, Atte

    2013-04-01

    The Arctic, representing a fifth of the earth's surface, is highly sensitive to the predicted future warming and it has indeed been warming up faster than most other regions. This makes the region critically important and highlights the need to investigate the earliest signals of global warming and its impacts on the arctic and subarctic aquatic ecosystems and their biota. It has been demonstrated that many Arctic freshwater ecosystems have already experienced dramatic and unpreceded regime shifts during the last ca. 150 years, primarily driven by climate warming. However, despite the indisputable impact of climate-related variables on freshwater ecosystems other, especially local-scale catchment related variables (e.g. geology, vegetation, human activities) may override the climate signal and become the primary factor in shaping the structure of aquatic ecosystems. Although many studies have contributed to an improved understanding of limnological and hydrobiological features of Artic and subarctic lakes, much information is still needed especially on the interaction between the biotic and abiotic components, i.e. on factors controlling the food web dynamics in these sensitive aquatic ecosystems. This is of special importance as these lakes are of great value in water storage, flood prevention, and maintenance of biodiversity, in addition to which they are vital resources for settlement patterns, food production, recreation, and tourism. In this study we compare the pre-industrial sediment assemblages of primary producers (diatoms and Pediastrum) and primary consumers (cladoceran and chironomids) with their modern assemblages (a top-bottom approach) from 50 subarctic Fennoscandian lakes. We will evaluate the recent regional pattern of changes in aquatic assemblages, and assess how coherent the lakes' responses are across the subarctic area. Moreover, the impact of global (e.g. climate, precipitation) and local (e.g. lake and its catchment characteristics) scale

  15. Rapid geochemical changes at Mawrth Vallis as observed through the mineralogical record

    Science.gov (United States)

    Bishop, J. L.

    2013-12-01

    The thick and widespread phyllosilicate outcrops observed in the Mawrth Vallis region indicate that abundant water was present here during the Noachian period. Factors shaping the formation and alteration of the observed phyllosilicates include aqueous processes, chemistry, and perhaps biology. The expansive phyllosilicate outcrops at Mawrth Vallis exhibit a consistent general trend of Al-phyllosilicates and amorphous Al/Si species at the top of the clay profile and Fe/Mg-phyllosilicates on the bottom. This implies either a change in water chemistry, a change in material being altered, or an alteration profile where the upper clays were leached and altered more significantly than those below. Localized variations in Al/Si-rich species [1,2] indicate pockets of acidic and neutral environments, likely formed through changes in the geochemical environment over a geologically short time period at the end of the Noachian. A change in iron in the phyllosilicate units is also observed such that an Fe2+-bearing unit is frequently observed between the Fe3+- and Mg-rich phyllosilicates below and the Al/Si-rich materials above [2]. Changes in oxidation state are often indicative of biogeochemical activity on Earth. CRISM spectra are shown in Figure 1 across a transect from an Al/Si-rich region to an Fe2+-bearing region to an Fe3+/Mg-phyllosilicate region. Phyllosilicate-bearing rocks may have been an ideal place on Mars for pre-biotic chemistry and possibly the development of life as well. Phyllosilicates, especially smectites, can serve as reaction surfaces that bind molecules and catalyze chemical reactions. Experiments have shown excellent survival of microbes in clay environments under extreme Mars-like temperature and humidity conditions. If microbes were present on Mars, the ancient Fe-smectite-bearing rocks could have been a favorable environment for them to evolve and possibly thrive. The Mawrth Vallis phyllosilicate outcrops are colored by changes in phyllosilicate

  16. Useful to Usable (U2U): Transforming Climate Variability and Change Information for Cereal Crop Producers

    Science.gov (United States)

    Niyogi, D.; Andresen, J.

    2011-12-01

    Corn and soybean production contributes over $100 billion annually to the U.S. economy, most of which comes from the intensely cultivated corn-belt region of the Midwest. Successful crop production in this region is highly dependent on favorable temperatures and appropriate precipitation patters, making this industry vulnerable to changes in climate patterns. Though predictive models are constantly improving, there are gaps in our understanding of how different management practices can be used to help farmers adapt to changes in climate while maintaining economic viability. Furthermore, currently available tools and models are not meeting producers' needs, and little is known about the types of information they would like to access. Useful to Usable (U2U): Transforming Climate Variability and Change Information for Cereal Crop Producers is an integrated research and extension project that seeks to improve the resilience and profitability of farms in the North Central Region amid variable climate change through the development and dissemination of improved decision support tools, resource materials, and training. The goal is to work closely with producers to help them make better long-term plans on what, when and where to plant, and also how to manage crops for maximum yields and minimum environmental damage. The U2U team is composed of a uniquely qualified group of climatologists, crop modelers, agronomists, economists, and social scientists from 10 partner universities across the Midwest. Over the span of 5 years, collaborators will complete tasks associated with 5 objectives that will enhance the usability of climate information for the agricultural community and lead to more sustainable farming operations. First the team will produce research on the biophysical and economic impacts of different climate scenarios on corn and soybean yields in the North Central Region (objective 1) and conduct complementary research to understand how producers and advisors are

  17. Cone-beam computed tomography evaluation of dental, skeletal, and alveolar bone changes associated with bonded rapid maxillary expansion

    Directory of Open Access Journals (Sweden)

    Namrata Dogra

    2016-01-01

    Full Text Available Aims and Objectives: To evaluate skeletal changes in maxilla and its surrounding structures, changes in the maxillary dentition and maxillary alveolar bone changes produced by bonded rapid maxillary expansion (RME using cone-beam computed tomography (CBCT. Materials and Methods: The sample consisted of 10 patients (6 males and 4 females with age range 12 to 15 years treated with bonded RME. CBCT scans were performed at T1 (pretreatment and at T2 (immediately after expansion to evaluate the dental, skeletal, and alveolar bone changes. Results: RME treatment increased the overall skeletal parameters such as interorbital, zygomatic, nasal, and maxillary widths. Significant increases in buccal maxillary width was observed at first premolar, second premolar, and first molar level. There was a significant increase in arch width both on the palatal side and on the buccal side. Significant tipping of right and left maxillary first molars was seen. There were significant reductions in buccal bone plate thickness and increase in palatal bone plate thickness. Conclusions: Total expansion achieved with RME was a combination of dental, skeletal and alveolar bone changes. At the first molar level, 28.45% orthopedic, 16.03% alveolar bone bending, and 55.5% orthodontic changes were observed.

  18. Rapid language-related plasticity: microstructural changes in the cortex after a short session of new word learning.

    Science.gov (United States)

    Hofstetter, Shir; Friedmann, Naama; Assaf, Yaniv

    2017-04-01

    Human brain imaging revealed that the brain can undergo structural plasticity following new learning experiences. Most magnetic resonance imaging (MRI) uncovered morphometric alternation in cortical density after the long-term training of weeks to months. A recent diffusion tensor imaging (DTI) study has found changes in diffusion indices after 2 h of training, primarily in the hippocampus. However, whether a short learning experience can induce microstructural changes in the neocortex is still unclear. Here, we used diffusion MRI, a method sensitive to tissue microstructure, to study cortical plasticity. To attain cortical involvement, we used a short language task (under 1 h) of introducing new lexical items (flower names) to the lexicon. We have found significant changes in diffusivity in cortical regions involved in language and reading (inferior frontal gyrus, middle temporal gyrus, and inferior parietal lobule). In addition, the difference in the values of diffusivity correlated with the lexical learning rate in the task. Moreover, significant changes were found in white matter tracts near the cortex, and the extent of change correlated with behavioral measures of lexical learning rate. These findings provide first evidence of short-term cortical plasticity in the human brain after a short language learning task. It seems that short training of less than an hour of high cognitive demand can induce microstructural changes in the cortex, suggesting a rapid time scale of neuroplasticity and providing additional evidence of the power of MRI to investigate the temporal and spatial progressions of this process.

  19. Object-based change detection in rapid urbanization regions with remotely sensed observations: a case study of Shenzhen, China

    Science.gov (United States)

    He, Lihuang; Dong, Guihua; Wang, Wei-Min; Yang, Lijun; Liang, Hong

    2013-10-01

    China, the most populous country on Earth, has experienced rapid urbanization which is one of the main causes of many environmental and ecological problems. Therefore, the monitoring of rapid urbanization regions and the environment is of critical importance for their sustainable development. In this study, the object-based classification is employed to detect the change of land cover in Shenzhen, which is located in South China and has been urbanized rapidly in recent three decades. First, four Landsat TM images, which were acquired on 1990, 2000 and 2010, respectively, are selected from the image database. Atmospheric corrections are conducted on these images with improved dark-object subtraction technique and surface meteorological observations. Geometric correction is processed with ground control points derived from topographic maps. Second, a region growing multi-resolution segmentation and a soft nearest neighbour classifier are used to finish object-based classification. After analyzing the fraction of difference classes over time series, we conclude that the comparison of derived land cover classes with socio-economic statistics demonstrates the strong positive correlation between built-up classes and urban population as well as gross GDP and GDPs in second and tertiary industries. Two different mechanisms of urbanization, namely new land development and redevelopment, are revealed. Consequently, we found that, the districts of Shenzhen were urbanized through different mechanisms.

  20. Spatiotemporal variability of extreme precipitation in Shaanxi province under climate change

    Science.gov (United States)