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Sample records for changing environment extinction

  1. Adaptation, plasticity, and extinction in a changing environment: towards a predictive theory.

    Directory of Open Access Journals (Sweden)

    Luis-Miguel Chevin

    2010-04-01

    Full Text Available Many species are experiencing sustained environmental change mainly due to human activities. The unusual rate and extent of anthropogenic alterations of the environment may exceed the capacity of developmental, genetic, and demographic mechanisms that populations have evolved to deal with environmental change. To begin to understand the limits to population persistence, we present a simple evolutionary model for the critical rate of environmental change beyond which a population must decline and go extinct. We use this model to highlight the major determinants of extinction risk in a changing environment, and identify research needs for improved predictions based on projected changes in environmental variables. Two key parameters relating the environment to population biology have not yet received sufficient attention. Phenotypic plasticity, the direct influence of environment on the development of individual phenotypes, is increasingly considered an important component of phenotypic change in the wild and should be incorporated in models of population persistence. Environmental sensitivity of selection, the change in the optimum phenotype with the environment, still crucially needs empirical assessment. We use environmental tolerance curves and other examples of ecological and evolutionary responses to climate change to illustrate how these mechanistic approaches can be developed for predictive purposes.

  2. How does climate change cause extinction?

    Science.gov (United States)

    Cahill, Abigail E; Aiello-Lammens, Matthew E; Fisher-Reid, M Caitlin; Hua, Xia; Karanewsky, Caitlin J; Ryu, Hae Yeong; Sbeglia, Gena C; Spagnolo, Fabrizio; Waldron, John B; Warsi, Omar; Wiens, John J

    2013-01-07

    Anthropogenic climate change is predicted to be a major cause of species extinctions in the next 100 years. But what will actually cause these extinctions? For example, will it be limited physiological tolerance to high temperatures, changing biotic interactions or other factors? Here, we systematically review the proximate causes of climate-change related extinctions and their empirical support. We find 136 case studies of climatic impacts that are potentially relevant to this topic. However, only seven identified proximate causes of demonstrated local extinctions due to anthropogenic climate change. Among these seven studies, the proximate causes vary widely. Surprisingly, none show a straightforward relationship between local extinction and limited tolerances to high temperature. Instead, many studies implicate species interactions as an important proximate cause, especially decreases in food availability. We find very similar patterns in studies showing decreases in abundance associated with climate change, and in those studies showing impacts of climatic oscillations. Collectively, these results highlight our disturbingly limited knowledge of this crucial issue but also support the idea that changing species interactions are an important cause of documented population declines and extinctions related to climate change. Finally, we briefly outline general research strategies for identifying these proximate causes in future studies.

  3. Late Pennsylvanian climate changes and palynomorph extinctions

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    Kosanke, R.M.; Cecil, C.B. [US Geological Survey, Denver, CO (United States)

    1996-01-01

    A major floral change occurs in the Upper Pennsylvanian strata in the Midcontinent, Illinois basin, and in the northern Appalachian basin of eastern United States. Lycospora spp. (derived from arborescent lycopsids) became extinct along with some other palynomorph taxa. This investigation is concerned with the importance of this major floral change. Samples were studied from western Pennsylvania, eastern Ohio, and West Virgina (from a previous study) cover the stratigraphic interval from the Upper Freeport coal bed, uppermost part of the Allegheny Formation, to the Mahoning, Mason, Brush Creek, Wilgus, and Anderson coal beds in the lower part of the Conemaugh Formation. The floral change occurs either at or below the accepted Desmoinesian-Missourian boundary in the Midcontinent and Illinois basin, whereas in the northern Appalachians this change occurs in the lower part of the Conemaugh Formation, between the Mahoning and Brush Creek coal beds, or when the Mason is present, between the Mahoning and Mason coal beds. The first coal bed above the extinction of Lycospora spp. is dominated by the palynomorph taxon Endosporites globiformis which is derived from a heterosporous, herbaceous lycopsid. However, Sigillaria, another arborescent lycopsid, did not become extinct at this time as evidenced by the presence of the palynomorph genus Crassispora which is derived from Sigillaria. The reason for the survival of Sigillaria is now known, but it may have been able to adapt, in a limited fashion, to some sort of specialized microenvironment. The ferns, based on palynomorph occurrence, become numerically more important throughout the balance of the Conemaugh Formation, and dominate the Pittsburgh No. 8 and Pomeroy coal beds in the overlying Monogahela Formation.

  4. Climate change, elevational range shifts, and bird extinctions.

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    Sekercioglu, Cagan H; Schneider, Stephen H; Fay, John P; Loarie, Scott R

    2008-02-01

    Limitations imposed on species ranges by the climatic, ecological, and physiological effects of elevation are important determinants of extinction risk. We modeled the effects of elevational limits on the extinction risk of landbirds, 87% of all bird species. Elevational limitation of range size explained 97% of the variation in the probability of being in a World Conservation Union category of extinction risk. Our model that combined elevational ranges, four Millennium Assessment habitat-loss scenarios, and an intermediate estimate of surface warming of 2.8 degrees C, projected a best guess of 400-550 landbird extinctions, and that approximately 2150 additional species would be at risk of extinction by 2100. For Western Hemisphere landbirds, intermediate extinction estimates based on climate-induced changes in actual distributions ranged from 1.3% (1.1 degrees C warming) to 30.0% (6.4 degrees C warming) of these species. Worldwide, every degree of warming projected a nonlinear increase in bird extinctions of about 100-500 species. Only 21% of the species predicted to become extinct in our scenarios are currently considered threatened with extinction. Different habitat-loss and surface-warming scenarios predicted substantially different futures for landbird species. To improve the precision of climate-induced extinction estimates, there is an urgent need for high-resolution measurements of shifts in the elevational ranges of species. Given the accelerating influence of climate change on species distributions and conservation, using elevational limits in a tested, standardized, and robust manner can improve conservation assessments of terrestrial species and will help identify species that are most vulnerable to global climate change. Our climate-induced extinction estimates are broadly similar to those of bird species at risk from other factors, but these estimates largely involve different sets of species.

  5. Extinction partially reverts structural changes associated with remote fear memory

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    Vetere, Gisella; Restivo, Leonardo; Novembre, Giovanni

    2011-01-01

    Structural synaptic changes occur in medial prefrontal cortex circuits during remote memory formation. Whether extinction reverts or further reshapes these circuits is, however, unknown. Here we show that the number and the size of spines were enhanced in anterior cingulate (aCC) and infralimbic...... (ILC) cortices 36 d following contextual fear conditioning. Upon extinction, aCC spine density returned to baseline, but the enhanced proportion of large spines did not. Differently, ILC spine density remained elevated, but the size of spines decreased dramatically. Thus, extinction partially erases...

  6. Climate change, species-area curves and the extinction crisis.

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    Lewis, Owen T

    2006-01-29

    An article published in the journal Nature in January 2004-in which an international team of biologists predicted that climate change would, by 2050, doom 15-37% of the earth's species to extinction-attracted unprecedented, worldwide media attention. The predictions conflict with the conventional wisdom that habitat change and modification are the most important causes of current and future extinctions. The new extinction projections come from applying a well-known ecological pattern, the species-area relationship (SAR), to data on the current distributions and climatic requirements of 1103 species. Here, I examine the scientific basis to the claims made in the Nature article. I first highlight the potential and pitfalls of using the SAR to predict extinctions in general. I then consider the additional complications that arise when applying SAR methods specifically to climate change. I assess the extent to which these issues call into question predictions of extinctions from climate change relative to other human impacts, and highlight a danger that conservation resources will be directed away from attempts to slow and mitigate the continuing effects of habitat destruction and degradation, particularly in the tropics. I suggest that the most useful contributions of ecologists over the coming decades will be in partitioning likely extinctions among interacting causes and identifying the practical means to slow the rate of species loss.

  7. Extinction Partially Reverts Structural Changes Associated with Remote Fear Memory

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    Vetere, Gisella; Restivo, Leonardo; Novembre, Giovanni; Aceti, Massimiliano; Lumaca, Massimo; Ammassari-Teule, Martine

    2011-01-01

    Structural synaptic changes occur in medial prefrontal cortex circuits during remote memory formation. Whether extinction reverts or further reshapes these circuits is, however, unknown. Here we show that the number and the size of spines were enhanced in anterior cingulate (aCC) and infralimbic (ILC) cortices 36 d following contextual fear…

  8. Ocean redox change at the Permian-Triassic mass extinction

    DEFF Research Database (Denmark)

    Ruhl, Micha; Bjerrum, Christian J.; Canfield, Donald Eugene

    2013-01-01

    Earth’s history is marked by multiple events of ocean anoxia developing along continental margins and po¬tentially into the open ocean realm. These events of¬ten coincide with the emplacement of large igneous provinces (LIPs) on continents, major perturbations of global geochemical cycles and mar...... these oceanographic changes to similar observations for the Triassic-Jurassic mass extinction and discuss environmental forcing, poten¬tially inherent to major volcanic events and leading to global environmental change and extinction...... ocean redox change over the largest mass extinction event in Earth history, at the Permian-Tri¬assic boundary (at ~252 Ma). This event is marked by a major perturbation in the global exogenic carbon cycle (and associated major negative carbon isotope excursion (CIE)), likely initiated by carbon...... (anoxic but not euxinic) coinciding with the main extinction event. Molybdenum enrichments, often indicative for freely available sulfide in the water-column, only occur dur¬ing the second phase of euxinia. This pattern of ocean redox-change in Svalbard direct¬ly reflects similar trends in Greenland...

  9. Extinction partially reverts structural changes associated with remote fear memory

    DEFF Research Database (Denmark)

    Vetere, Gisella; Restivo, Leonardo; Novembre, Giovanni

    2011-01-01

    Structural synaptic changes occur in medial prefrontal cortex circuits during remote memory formation. Whether extinction reverts or further reshapes these circuits is, however, unknown. Here we show that the number and the size of spines were enhanced in anterior cingulate (aCC) and infralimbic...... the remote memory network, suggesting that the preserved network properties might sustain reactivation of extinguished conditioned fear....

  10. Amount of fear extinction changes its underlying mechanisms.

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    An, Bobae; Kim, Jihye; Park, Kyungjoon; Lee, Sukwon; Song, Sukwoon; Choi, Sukwoo

    2017-07-03

    There has been a longstanding debate on whether original fear memory is inhibited or erased after extinction. One possibility that reconciles this uncertainty is that the inhibition and erasure mechanisms are engaged in different phases (early or late) of extinction. In this study, using single-session extinction training and its repetition (multiple-session extinction training), we investigated the inhibition and erasure mechanisms in the prefrontal cortex and amygdala of rats, where neural circuits underlying extinction reside. The inhibition mechanism was prevalent with single-session extinction training but faded when single-session extinction training was repeated. In contrast, the erasure mechanism became prevalent when single-session extinction training was repeated. Moreover, ablating the intercalated neurons of amygdala, which are responsible for maintaining extinction-induced inhibition, was no longer effective in multiple-session extinction training. We propose that the inhibition mechanism operates primarily in the early phase of extinction training, and the erasure mechanism takes over after that.

  11. Climate change, humans, and the extinction of the woolly mammoth.

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    David Nogués-Bravo

    2008-04-01

    Full Text Available Woolly mammoths inhabited Eurasia and North America from late Middle Pleistocene (300 ky BP [300,000 years before present], surviving through different climatic cycles until they vanished in the Holocene (3.6 ky BP. The debate about why the Late Quaternary extinctions occurred has centred upon environmental and human-induced effects, or a combination of both. However, testing these two hypotheses-climatic and anthropogenic-has been hampered by the difficulty of generating quantitative estimates of the relationship between the contraction of the mammoth's geographical range and each of the two hypotheses. We combined climate envelope models and a population model with explicit treatment of woolly mammoth-human interactions to measure the extent to which a combination of climate changes and increased human pressures might have led to the extinction of the species in Eurasia. Climate conditions for woolly mammoths were measured across different time periods: 126 ky BP, 42 ky BP, 30 ky BP, 21 ky BP, and 6 ky BP. We show that suitable climate conditions for the mammoth reduced drastically between the Late Pleistocene and the Holocene, and 90% of its geographical range disappeared between 42 ky BP and 6 ky BP, with the remaining suitable areas in the mid-Holocene being mainly restricted to Arctic Siberia, which is where the latest records of woolly mammoths in continental Asia have been found. Results of the population models also show that the collapse of the climatic niche of the mammoth caused a significant drop in their population size, making woolly mammoths more vulnerable to the increasing hunting pressure from human populations. The coincidence of the disappearance of climatically suitable areas for woolly mammoths and the increase in anthropogenic impacts in the Holocene, the coup de grâce, likely set the place and time for the extinction of the woolly mammoth.

  12. [On the extinction of populations with several types in a random environment].

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    Bacaër, Nicolas

    2018-03-01

    This study focuses on the extinction rate of a population that follows a continuous-time multi-type branching process in a random environment. Numerical computations in a particular example inspired by an epidemic model suggest an explicit formula for this extinction rate, but only for certain parameter values. Copyright © 2018 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  13. Methanol Droplet Extinction in Carbon-Dioxide-Enriched Environments in Microgravity

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    Hicks, Michael C.; Nayagam, Vedha; Williams, Forman A.

    2010-01-01

    Diffusive extinction of methanol droplets with initial diameters between 1.25 mm and 1.72 mm, burning in a quiescent microgravity environment at one atmosphere pressure, was obtained experimentally for varying levels of ambient carbon-dioxide concentrations with a fixed oxygen concentration of 21% and a balance of nitrogen. These experiments serve as precursors to those which are beginning to be performed on the International Space Station and are motivated by the need to understand the effectiveness of carbon-dioxide as a fire suppressant in low-gravity environments. In these experiments, the flame standoff distance, droplet diameter, and flame radiation are measured as functions of time. The results show that the droplet extinction diameter depends on both the initial droplet diameter and the ambient concentration of carbon dioxide. Increasing the initial droplet diameter leads to an increased extinction diameter, while increasing the carbon-dioxide concentration leads to a slight decrease in the extinction diameter. These results are interpreted using a critical Damk hler number for extinction as predicted by an earlier theory, which is extended here to be applicable in the presence of effects of heat conduction along the droplet support fibers and of the volume occupied by the support beads

  14. Climate change not to blame for late Quaternary megafauna extinctions in Australia.

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    Saltré, Frédérik; Rodríguez-Rey, Marta; Brook, Barry W; Johnson, Christopher N; Turney, Chris S M; Alroy, John; Cooper, Alan; Beeton, Nicholas; Bird, Michael I; Fordham, Damien A; Gillespie, Richard; Herrando-Pérez, Salvador; Jacobs, Zenobia; Miller, Gifford H; Nogués-Bravo, David; Prideaux, Gavin J; Roberts, Richard G; Bradshaw, Corey J A

    2016-01-29

    Late Quaternary megafauna extinctions impoverished mammalian diversity worldwide. The causes of these extinctions in Australia are most controversial but essential to resolve, because this continent-wide event presaged similar losses that occurred thousands of years later on other continents. Here we apply a rigorous metadata analysis and new ensemble-hindcasting approach to 659 Australian megafauna fossil ages. When coupled with analysis of several high-resolution climate records, we show that megafaunal extinctions were broadly synchronous among genera and independent of climate aridity and variability in Australia over the last 120,000 years. Our results reject climate change as the primary driver of megafauna extinctions in the world's most controversial context, and instead estimate that the megafauna disappeared Australia-wide ∼13,500 years after human arrival, with shorter periods of coexistence in some regions. This is the first comprehensive approach to incorporate uncertainty in fossil ages, extinction timing and climatology, to quantify mechanisms of prehistorical extinctions.

  15. Diversity, competition, extinction: the ecophysics of language change.

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    Solé, Ricard V; Corominas-Murtra, Bernat; Fortuny, Jordi

    2010-12-06

    As indicated early by Charles Darwin, languages behave and change very much like living species. They display high diversity, differentiate in space and time, emerge and disappear. A large body of literature has explored the role of information exchanges and communicative constraints in groups of agents under selective scenarios. These models have been very helpful in providing a rationale on how complex forms of communication emerge under evolutionary pressures. However, other patterns of large-scale organization can be described using mathematical methods ignoring communicative traits. These approaches consider shorter time scales and have been developed by exploiting both theoretical ecology and statistical physics methods. The models are reviewed here and include extinction, invasion, origination, spatial organization, coexistence and diversity as key concepts and are very simple in their defining rules. Such simplicity is used in order to catch the most fundamental laws of organization and those universal ingredients responsible for qualitative traits. The similarities between observed and predicted patterns indicate that an ecological theory of language is emerging, supporting (on a quantitative basis) its ecological nature, although key differences are also present. Here, we critically review some recent advances and outline their implications and limitations as well as highlight problems for future research.

  16. On the regularity of the extinction probability of a branching process in varying and random environments

    International Nuclear Information System (INIS)

    Alili, Smail; Rugh, Hans Henrik

    2008-01-01

    We consider a supercritical branching process in time-dependent environment ξ. We assume that the offspring distributions depend regularly (C k or real-analytically) on real parameters λ. We show that the extinction probability q λ (ξ), given the environment ξ 'inherits' this regularity whenever the offspring distributions satisfy a condition of contraction-type. Our proof makes use of the Poincaré metric on the complex unit disc and a real-analytic implicit function theorem

  17. Changes in expression of c-Fos protein following cocaine-cue extinction learning.

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    Nic Dhonnchadha, B Á; Lovascio, B F; Shrestha, N; Lin, A; Leite-Morris, K A; Man, H Y; Kaplan, G B; Kantak, K M

    2012-09-01

    Extinguishing abnormally strengthened learned responses to cues associated with drugs of abuse remains a key tactic for alleviating addiction. To assist in developing pharmacotherapies to augment exposure therapy for relapse prevention, investigation into neurobiological underpinnings of drug-cue extinction learning is needed. We used regional analyses of c-Fos and GluR2 protein expression to delineate neural activity and plasticity that may be associated with cocaine-cue extinction learning. Rats were trained to self-administer cocaine paired with a light cue, and later underwent a single 2h extinction session for which cocaine was withheld but response-contingent cues were presented (cocaine-cue extinction). Control groups consisted of rats yoked to animals self-administering cocaine and receiving saline non-contingently followed by an extinction session, or rats trained to self-administer cocaine followed by a no-extinction session for which levers were retracted, and cocaine and cues were withheld. Among 11 brain sites examined, extinction training increased c-Fos expression in basolateral amygdala and prelimbic prefrontal cortex of cocaine-cue extinguished rats relative to both control conditions. In dorsal subiculum and infralimbic prefrontal cortex, extinction training increased c-Fos expression in both cocaine-cue and saline-cue extinguished rats relative to the no-extinction control condition. GluR2 protein expression was not altered in any site examined after extinction or control training. Findings suggest that basolateral amygdala and prelimbic prefrontal cortex neurons are activated during acquisition of cocaine-cue extinction learning, a process that is independent of changes in GluR2 abundance. Other sites are implicated in processing the significance of cues that are present early in extinction training. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Persistence and extinction of an n-species mutualism model with random perturbations in a polluted environment

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    He, Xin; Shan, Meijing; Liu, Meng

    2018-02-01

    An n-species stochastic Lotka-Volterra cooperative model in a polluted environment is proposed and studied. For each species, sufficient conditions for extinction, non-persistence in the mean and weak persistence in the mean are established. The threshold between weak persistence in the mean and extinction is obtained. Several numerical figures are also worked out to validate the theoretical results.

  19. Paleogenomics in a temperate environment: shotgun sequencing from an extinct Mediterranean caprine.

    Directory of Open Access Journals (Sweden)

    Oscar Ramírez

    Full Text Available BACKGROUND: Numerous endemic mammals, including dwarf elephants, goats, hippos and deers, evolved in isolation in the Mediterranean islands during the Pliocene and Pleistocene. Most of them subsequently became extinct during the Holocene. Recently developed high-throughput sequencing technologies could provide a unique tool for retrieving genomic data from these extinct species, making it possible to study their evolutionary history and the genetic bases underlying their particular, sometimes unique, adaptations. METHODOLOGY/PRINCIPALS FINDINGS: A DNA extraction of a approximately 6,000 year-old bone sample from an extinct caprine (Myotragus balearicus from the Balearic Islands in the Western Mediterranean, has been subjected to shotgun sequencing with the GS FLX 454 platform. Only 0.27% of the resulting sequences, identified from alignments with the cow genome and comprising 15,832 nucleotides, with an average length of 60 nucleotides, proved to be endogenous. CONCLUSIONS: A phylogenetic tree generated with Myotragus sequences and those from other artiodactyls displays an identical topology to that generated from mitochondrial DNA data. Despite being in an unfavourable thermal environment, which explains the low yield of endogenous sequences, our study demonstrates that it is possible to obtain genomic data from extinct species from temperate regions.

  20. Micro-evolutionary diversification among Indian Ocean parrots: temporal and spatial changes in phylogenetic diversity as a consequence of extinction and invasion

    OpenAIRE

    Jackson, H; Jones, C G; Agapow, P-M; Tatayah, V; Groombridge, Jim J.

    2015-01-01

    Almost 90% of global bird extinctions have occurred on islands. The loss of endemic spe- cies from island systems can dramatically alter evolutionary trajectories of insular species biodiversity, resulting in a loss of evolutionary diversity important for species adaptation to changing environments. The Western Indian Ocean islands have been the scene of evolution for a large number of endemic parrots. Since their discovery in the 16th cen- tury, many of these parrots have become extinct or h...

  1. Salinity changes and anoxia resulting from enhanced run-off during the late Permian global warming and mass extinction event

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    E. E. van Soelen

    2018-04-01

    Full Text Available The late Permian biotic crisis had a major impact on marine and terrestrial environments. Rising CO2 levels following Siberian Trap volcanic activity were likely responsible for expanding marine anoxia and elevated water temperatures. This study focuses on one of the stratigraphically most expanded Permian–Triassic records known, from Jameson Land, East Greenland. High-resolution sampling allows for a detailed reconstruction of the changing environmental conditions during the extinction event and the development of anoxic water conditions. Since very little is known about how salinity was affected during the extinction event, we especially focus on the aquatic palynomorphs and infer changes in salinity from changes in the assemblage and morphology. The start of the extinction event, here defined by a peak in spore : pollen, indicating disturbance and vegetation destruction in the terrestrial environment, postdates a negative excursion in the total organic carbon, but predates the development of anoxia in the basin. Based on the newest estimations for sedimentation rates, the marine and terrestrial ecosystem collapse took between 1.6 and 8 kyr, a much shorter interval than previously estimated. The palynofacies and palynomorph records show that the environmental changes can be explained by enhanced run-off and increased primary productivity and water column stratification. A lowering in salinity is supported by changes in the acritarch morphology. The length of the processes of the acritarchs becomes shorter during the extinction event and we propose that these changes are evidence for a reduction in salinity in the shallow marine setting of the study site. This inference is supported by changes in acritarch distribution, which suggest a change in palaeoenvironment from open marine conditions before the start of the extinction event to more nearshore conditions during and after the crisis. In a period of sea-level rise, such a reduction

  2. Salinity changes and anoxia resulting from enhanced run-off during the late Permian global warming and mass extinction event

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    van Soelen, Elsbeth E.; Twitchett, Richard J.; Kürschner, Wolfram M.

    2018-04-01

    The late Permian biotic crisis had a major impact on marine and terrestrial environments. Rising CO2 levels following Siberian Trap volcanic activity were likely responsible for expanding marine anoxia and elevated water temperatures. This study focuses on one of the stratigraphically most expanded Permian-Triassic records known, from Jameson Land, East Greenland. High-resolution sampling allows for a detailed reconstruction of the changing environmental conditions during the extinction event and the development of anoxic water conditions. Since very little is known about how salinity was affected during the extinction event, we especially focus on the aquatic palynomorphs and infer changes in salinity from changes in the assemblage and morphology. The start of the extinction event, here defined by a peak in spore : pollen, indicating disturbance and vegetation destruction in the terrestrial environment, postdates a negative excursion in the total organic carbon, but predates the development of anoxia in the basin. Based on the newest estimations for sedimentation rates, the marine and terrestrial ecosystem collapse took between 1.6 and 8 kyr, a much shorter interval than previously estimated. The palynofacies and palynomorph records show that the environmental changes can be explained by enhanced run-off and increased primary productivity and water column stratification. A lowering in salinity is supported by changes in the acritarch morphology. The length of the processes of the acritarchs becomes shorter during the extinction event and we propose that these changes are evidence for a reduction in salinity in the shallow marine setting of the study site. This inference is supported by changes in acritarch distribution, which suggest a change in palaeoenvironment from open marine conditions before the start of the extinction event to more nearshore conditions during and after the crisis. In a period of sea-level rise, such a reduction in salinity can only be

  3. Separating sensitivity from exposure in assessing extinction risk from climate change.

    Science.gov (United States)

    Dickinson, Maria G; Orme, C David L; Suttle, K Blake; Mace, Georgina M

    2014-11-04

    Predictive frameworks of climate change extinction risk generally focus on the magnitude of climate change a species is expected to experience and the potential for that species to track suitable climate. A species' risk of extinction from climate change will depend, in part, on the magnitude of climate change the species experiences, its exposure. However, exposure is only one component of risk. A species' risk of extinction will also depend on its intrinsic ability to tolerate changing climate, its sensitivity. We examine exposure and sensitivity individually for two example taxa, terrestrial amphibians and mammals. We examine how these factors are related among species and across regions and how explicit consideration of each component of risk may affect predictions of climate change impacts. We find that species' sensitivities to climate change are not congruent with their exposures. Many highly sensitive species face low exposure to climate change and many highly exposed species are relatively insensitive. Separating sensitivity from exposure reveals patterns in the causes and drivers of species' extinction risk that may not be evident solely from predictions of climate change. Our findings emphasise the importance of explicitly including sensitivity and exposure to climate change in assessments of species' extinction risk.

  4. Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment II.

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    Liu, Meng; Wang, Ke

    2010-12-07

    This is a continuation of our paper [Liu, M., Wang, K., 2010. Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment, J. Theor. Biol. 264, 934-944]. Taking both white noise and colored noise into account, a stochastic single-species model under regime switching in a polluted environment is studied. Sufficient conditions for extinction, stochastic nonpersistence in the mean, stochastic weak persistence and stochastic permanence are established. The threshold between stochastic weak persistence and extinction is obtained. The results show that a different type of noise has a different effect on the survival results. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Asymmetric competition impacts evolutionary rescue in a changing environment.

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    Van Den Elzen, Courtney L; Kleynhans, Elizabeth J; Otto, Sarah P

    2017-06-28

    Interspecific competition can strongly influence the evolutionary response of a species to a changing environment, impacting the chance that the species survives or goes extinct. Previous work has shown that when two species compete for a temporally shifting resource distribution, the species lagging behind the resource peak is the first to go extinct due to competitive exclusion. However, this work assumed symmetrically distributed resources and competition. Asymmetries can generate differences between species in population sizes, genetic variation and trait means. We show that asymmetric resource availability or competition can facilitate coexistence and even occasionally cause the leading species to go extinct first. Surprisingly, we also find cases where traits evolve in the opposite direction to the changing environment because of a 'vacuum of competitive release' created when the lagging species declines in number. Thus, the species exhibiting the slowest rate of trait evolution is not always the most likely to go extinct in a changing environment. Our results demonstrate that the extent to which species appear to be tracking environmental change and the extent to which they are preadapted to that change may not necessarily determine which species will be the winners and which will be the losers in a rapidly changing world. © 2017 The Author(s).

  6. Population extinction under bursty reproduction in a time-modulated environment

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    Vilk, Ohad; Assaf, Michael

    2018-06-01

    In recent years nondemographic variability has been shown to greatly affect dynamics of stochastic populations. For example, nondemographic noise in the form of a bursty reproduction process with an a priori unknown burst size, or environmental variability in the form of time-varying reaction rates, have been separately found to dramatically impact the extinction risk of isolated populations. In this work we investigate the extinction risk of an isolated population under the combined influence of these two types of nondemographic variation. Using the so-called momentum-space Wentzel-Kramers-Brillouin (WKB) approach and accounting for the explicit time dependence in the reaction rates, we arrive at a set of time-dependent Hamilton equations. To this end, we evaluate the population's extinction risk by finding the instanton of the time-perturbed Hamiltonian numerically, whereas analytical expressions are presented in particular limits using various perturbation techniques. We focus on two classes of time-varying environments: periodically varying rates corresponding to seasonal effects and a sudden decrease in the birth rate corresponding to a catastrophe. All our theoretical results are tested against numerical Monte Carlo simulations with time-dependent rates and also against a numerical solution of the corresponding time-dependent Hamilton equations.

  7. Incorporating climate and ocean change into extinction risk assessments for 82 coral species.

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    Brainard, Russell E; Weijerman, Mariska; Eakin, C Mark; McElhany, Paul; Miller, Margaret W; Patterson, Matt; Piniak, Gregory A; Dunlap, Matthew J; Birkeland, Charles

    2013-12-01

    Many marine invertebrate species facing potential extinction have uncertain taxonomies and poorly known demographic and ecological traits. Uncertainties are compounded when potential extinction drivers are climate and ocean changes whose effects on even widespread and abundant species are only partially understood. The U.S. Endangered Species Act mandates conservation management decisions founded on the extinction risk to species based on the best available science at the time of consideration-requiring prompt action rather than awaiting better information. We developed an expert-opinion threat-based approach that entails a structured voting system to assess extinction risk from climate and ocean changes and other threats to 82 coral species for which population status and threat response information was limited. Such methods are urgently needed because constrained budgets and manpower will continue to hinder the availability of desired data for many potentially vulnerable marine species. Significant species-specific information gaps and uncertainties precluded quantitative assessments of habitat loss or population declines and necessitated increased reliance on demographic characteristics and threat vulnerabilities at genus or family levels. Adapting some methods (e.g., a structured voting system) used during other assessments and developing some new approaches (e.g., integrated assessment of threats and demographic characteristics), we rated the importance of threats contributing to coral extinction risk and assessed those threats against population status and trend information to evaluate each species' extinction risk over the 21st century. This qualitative assessment resulted in a ranking with an uncertainty range for each species according to their estimated likelihood of extinction. We offer guidance on approaches for future biological extinction risk assessments, especially in cases of data-limited species likely to be affected by global-scale threats

  8. Contextual Change After Fear Acquisition Affects Conditioned Responding and the Time Course of Extinction Learning-Implications for Renewal Research.

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    Sjouwerman, Rachel; Niehaus, Johanna; Lonsdorf, Tina B

    2015-01-01

    Context plays a central role in retrieving (fear) memories. Accordingly, context manipulations are inherent to most return of fear (ROF) paradigms (in particular renewal), involving contextual changes after fear extinction. Context changes are, however, also often embedded during earlier stages of ROF experiments such as context changes between fear acquisition and extinction (e.g., in ABC and ABA renewal). Previous studies using these paradigms have however focused exclusively on the context switch after extinction (i.e., renewal). Thus, the possibility of a general effect of context switch on conditioned responding that may not be conditional to preceding extinction learning remains unstudied. Hence, the current study investigated the impact of a context switch between fear acquisition and extinction on immediate conditioned responding and on the time-course of extinction learning by using a multimodal approach. A group that underwent contextual change after fear conditioning (AB; n = 36) was compared with a group without a contextual change from acquisition to extinction (AA; n = 149), while measuring physiological (skin conductance and fear potentiated startle) measures and subjective fear ratings. Contextual change between fear acquisition and extinction had a pronounced effect on both immediate conditioned responding and on the time course of extinction learning in skin conductance responses and subjective fear ratings. This may have important implications for the mechanisms underlying and the interpretation of the renewal effect (i.e., contextual switch after extinction). Consequently, future studies should incorporate designs and statistical tests that disentangle general effects of contextual change from genuine ROF effects.

  9. Brain functional network changes following Prelimbic area inactivation in a spatial memory extinction task.

    Science.gov (United States)

    Méndez-Couz, Marta; Conejo, Nélida M; Vallejo, Guillermo; Arias, Jorge L

    2015-01-01

    Several studies suggest a prefrontal cortex involvement during the acquisition and consolidation of spatial memory, suggesting an active modulating role at late stages of acquisition processes. Recently, we have reported that the prelimbic and infralimbic areas of the prefrontal cortex, among other structures, are also specifically involved in the late phases of spatial memory extinction. This study aimed to evaluate whether the inactivation of the prelimbic area of the prefrontal cortex impaired spatial memory extinction. For this purpose, male Wistar rats were implanted bilaterally with cannulae into the prelimbic region of the prefrontal cortex. Animals were trained during 5 consecutive days in a hidden platform task and tested for reference spatial memory immediately after the last training session. One day after completing the training task, bilateral infusion of the GABAA receptor agonist Muscimol was performed before the extinction protocol was carried out. Additionally, cytochrome c oxidase histochemistry was applied to map the metabolic brain activity related to the spatial memory extinction under prelimbic cortex inactivation. Results show that animals acquired the reference memory task in the water maze, and the extinction task was successfully completed without significant impairment. However, analysis of the functional brain networks involved by cytochrome oxidase activity interregional correlations showed changes in brain networks between the group treated with Muscimol as compared to the saline-treated group, supporting the involvement of the mammillary bodies at a the late stage in the memory extinction process. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Climate change not to blame for late Quaternary megafauna extinctions in Australia

    Science.gov (United States)

    Saltré, Frédérik; Rodríguez-Rey, Marta; Brook, Barry W.; Johnson, Christopher N; Turney, Chris S. M.; Alroy, John; Cooper, Alan; Beeton, Nicholas; Bird, Michael I.; Fordham, Damien A.; Gillespie, Richard; Herrando-Pérez, Salvador; Jacobs, Zenobia; Miller, Gifford H.; Nogués-Bravo, David; Prideaux, Gavin J.; Roberts, Richard G.; Bradshaw, Corey J. A.

    2016-01-01

    Late Quaternary megafauna extinctions impoverished mammalian diversity worldwide. The causes of these extinctions in Australia are most controversial but essential to resolve, because this continent-wide event presaged similar losses that occurred thousands of years later on other continents. Here we apply a rigorous metadata analysis and new ensemble-hindcasting approach to 659 Australian megafauna fossil ages. When coupled with analysis of several high-resolution climate records, we show that megafaunal extinctions were broadly synchronous among genera and independent of climate aridity and variability in Australia over the last 120,000 years. Our results reject climate change as the primary driver of megafauna extinctions in the world's most controversial context, and instead estimate that the megafauna disappeared Australia-wide ∼13,500 years after human arrival, with shorter periods of coexistence in some regions. This is the first comprehensive approach to incorporate uncertainty in fossil ages, extinction timing and climatology, to quantify mechanisms of prehistorical extinctions. PMID:26821754

  11. Shasta ground sloth ( Nothrotheriops shastense hoffstetter) at Shelter Cave, New Mexico: Environment, diet, and extinction

    Science.gov (United States)

    Thompson, Robert S.; Van Devender, Thomas R.; Martin, Paul S.; Foppe, Theresa; Long, Austin

    1980-11-01

    Seven coprolites of the extinct Shasta ground sloth ( Nothrotheriops shastense) were recently discovered in the Los Angeles County Museum collection from Shelter Cave, New Mexico. Three dung balls provided radiocarbon ages of 11,330, 12,330 and 12,430 yr B.P. Packrat ( Neotoma) middens disclose a xeric juniper woodland at Shelter Cave during the sloth's occupation. Plant cuticles from the dung indicate that the ground sloth had a diet dominated by mormon tea ( Ephedra) and other xerophytic shrubs. Pollen spectra from the coprolites have high representations of anemophilous plants and low representations of the dietary items shown in the cuticle analysis. Fifteen radiocarbon dates of sloth dung obtained since 1974 strengthen the hypothesis that sloth extinction occurred about 11,000 yr B.P. Paleoenvironmental studies indicate that ground sloths lived in juniper woodlands and montane conifer communities. Nothrotheriops commonly dined on shrubs that are still present in these habitats. It is difficult to explain the demise of the Shasta ground sloth by climatic change or dietary stress. Human predation remains as a possible explanation; ground sloth extinction appears to coincide with the time of Clovis mammoth hunters.

  12. Late Frasnian mass extinction: Conodont event stratigraphy, global changes, and possible causes

    Science.gov (United States)

    Sandberg, Charles A.; Ziegler, Willi; Dreesen, Roland; Butler, Jamie L.

    1988-01-01

    Several abrupt changes in conodont biofacies are documented to occur synchronously at six primary control sections across the Frasnian-Famennian boundary in Euramerica. These changes occurred within a time-span of only about 100,000 years near the end of the latest Frasnian linguiformis Zone, which is formally named to replace the Uppermost gigas Zone. The conodont-biofacies changes are interpreted to reflect a eustatic rise followed by an abrupt eustatic fall immediately preceding the late Frasnian mass extinction. Two new conodont species are named and described. Ancyrognathus ubiquitus n.sp. is recorded only just below and above the level of late Frasnian extinction and hence is a global marker for that event. Palmatolepispraetriangularis n.sp. is the long-sought Frasnian ancestor of the formerly cryptogenic species, Pa. triangularis, indicator of the earliest Famennian Lower triangularis Zone. The actual extinction event occurred entirely within the Frasnian and is interpreted to have been of brief duration-from as long as 20,000 years to as short as several days. The eustatic rise-and-fall couplet associated with the late Frasnian mass extinction is similar to eustatic couplets associated with the demise of most Frasnian (F2h) reefs worldwide about 1 m.y. earlier and with a latest Famennian mass extinction about 9.5 m.y. later. All these events may be directly or indirectly attributable to extraterrestrial triggering mechanisms. An impact of a small bolide or a near miss of a larger bolide may have caused the earlier demise of Frasnian reefs. An impact of possibly the same larger bolide in the Southern Hemisphere would explain the late Frasnian mass extinction. Global regression during the Famennian probably resulted from Southern-Hemisphere glaciation triggered by the latest Frasnian impact. Glaciation probably was the indirect cause of the latest Famennian mass extinction.

  13. Persistence and extinction of a stochastic single-species population model in a polluted environment with impulsive toxicant input

    Directory of Open Access Journals (Sweden)

    Meng Liu

    2013-10-01

    Full Text Available A stochastic single-species population system in a polluted environment with impulsive toxicant input is proposed and studied. Sufficient conditions for extinction, non-persistence in the mean, strong persistence in the mean and stochastic permanence of the population are established. The threshold between strong persistence in the mean and extinction is obtained. Some simulation figures are introduced to illustrate the main results.

  14. Global late Quaternary megafauna extinctions linked to humans, not climate change

    DEFF Research Database (Denmark)

    Sandom, Christopher James; Faurby, Søren; Sandel, Brody Steven

    2014-01-01

    by glacial–interglacial climate change and humans. We show that the severity of extinction is strongly tied to hominin palaeobiogeography, with at most a weak, Eurasia-specific link to climate change. This first species-level macroscale analysis at relatively high geographical resolution provides strong...

  15. Global late Quaternary megafauna extinctions linked to humans, not climate change.

    Science.gov (United States)

    Sandom, Christopher; Faurby, Søren; Sandel, Brody; Svenning, Jens-Christian

    2014-07-22

    The late Quaternary megafauna extinction was a severe global-scale event. Two factors, climate change and modern humans, have received broad support as the primary drivers, but their absolute and relative importance remains controversial. To date, focus has been on the extinction chronology of individual or small groups of species, specific geographical regions or macroscale studies at very coarse geographical and taxonomic resolution, limiting the possibility of adequately testing the proposed hypotheses. We present, to our knowledge, the first global analysis of this extinction based on comprehensive country-level data on the geographical distribution of all large mammal species (more than or equal to 10 kg) that have gone globally or continentally extinct between the beginning of the Last Interglacial at 132,000 years BP and the late Holocene 1000 years BP, testing the relative roles played by glacial-interglacial climate change and humans. We show that the severity of extinction is strongly tied to hominin palaeobiogeography, with at most a weak, Eurasia-specific link to climate change. This first species-level macroscale analysis at relatively high geographical resolution provides strong support for modern humans as the primary driver of the worldwide megafauna losses during the late Quaternary.

  16. Life history and spatial traits predict extinction risk due to climate change

    Science.gov (United States)

    Pearson, Richard G.; Stanton, Jessica C.; Shoemaker, Kevin T.; Aiello-Lammens, Matthew E.; Ersts, Peter J.; Horning, Ned; Fordham, Damien A.; Raxworthy, Christopher J.; Ryu, Hae Yeong; McNees, Jason; Akçakaya, H. Reşit

    2014-03-01

    There is an urgent need to develop effective vulnerability assessments for evaluating the conservation status of species in a changing climate. Several new assessment approaches have been proposed for evaluating the vulnerability of species to climate change based on the expectation that established assessments such as the IUCN Red List need revising or superseding in light of the threat that climate change brings. However, although previous studies have identified ecological and life history attributes that characterize declining species or those listed as threatened, no study so far has undertaken a quantitative analysis of the attributes that cause species to be at high risk of extinction specifically due to climate change. We developed a simulation approach based on generic life history types to show here that extinction risk due to climate change can be predicted using a mixture of spatial and demographic variables that can be measured in the present day without the need for complex forecasting models. Most of the variables we found to be important for predicting extinction risk, including occupied area and population size, are already used in species conservation assessments, indicating that present systems may be better able to identify species vulnerable to climate change than previously thought. Therefore, although climate change brings many new conservation challenges, we find that it may not be fundamentally different from other threats in terms of assessing extinction risks.

  17. Evolution in changing environments

    NARCIS (Netherlands)

    Gorter, Florien A.

    2017-01-01

    Directional environmental change in the form of global climate change and human-induced pollution is one of the most pressing problems facing society today. While species can sometimes adapt to such change by means of phenotypic plasticity and range shifts, there is considerable concern that

  18. A scenario for impacts of water availability loss due to climate change on riverine fish extinction rates

    OpenAIRE

    Tedesco, Pablo; Oberdorff, Thierry; Cornu, Jean-François; Beauchard, O.; Brosse, S.; Durr, H. H.; Grenouillet, G.; Leprieur, F.; Tisseuil, Clément; Zaiss, Rainer; Hugueny, Bernard

    2013-01-01

    1. Current models estimating impact of habitat loss on biodiversity in the face of global climate change usually project only percentages of species committed to extinction' on an uncertain time-scale. Here, we show that this limitation can be overcome using an empirically derived background extinction rate-area' curve to estimate natural rates and project future rates of freshwater fish extinction following variations in river drainage area resulting from global climate change.2. Based on fu...

  19. Graptolite community responses to global climate change and the late ordovician mass extinction

    Czech Academy of Sciences Publication Activity Database

    Sheets, H. D.; Melchin, M. J.; Loxton, J.; Štorch, Petr; Carlucci, K. L.; Hawkins, A. D.

    2016-01-01

    Roč. 113, č. 30 (2016), s. 8380-8385 ISSN 0027-8424 R&D Projects: GA AV ČR IAA301110908 Institutional support: RVO:67985831 Keywords : abundance * climate change * extinction * macroevolution * selection Subject RIV: DB - Geology ; Mineralogy Impact factor: 9.661, year: 2016

  20. Synergistic effects of climate change and harvest on extinction risk of American ginseng.

    Science.gov (United States)

    Souther, Sara; McGraw, James B

    Over the next century, the conservation of biodiversity will depend not only on our ability to understand the effect of climate change, but also on our capacity to predict how other factors interact with climate change to influence species viability. We used American ginseng (Panax quinquefolius L.), the United States' premier wild-harvested medicinal, as a model system to ask whether the effect of harvest on extinction risk depends on changing climatic conditions. We performed stochastic projections of viability response to an increase in maximum growing-season temperature of 1°C over the next 70 years by sampling matrices from long-term demographic studies of 12 populations (representing 75 population-years of data). In simulations that included harvest and climate change, extinction risk at the median population size (N = 140) was 65%, far exceeding the additive effects of the two factors (extinction risk = 8% and 6% for harvest and climate change, respectively; quasi-extinction threshold = 20). We performed a life table response experiment (LTRE) to determine underlying causes of the effect of warming and harvest on deterministic λ (λd). Together, these factors decreased λd values primarily by reducing growth of juvenile and small adult plants to the large-adult stage, as well as decreasing stasis of the juveniles and large adults. The interaction observed in stochastic model results followed from a nonlinear increase in extinction risk as the combined impact of harvest and warming consistently reduced λ values below the demographic tipping point of λ = 1. While further research is needed to create specific recommendations, these findings indicate that ginseng harvest regulations should be revised to account for changing climate. Given the possibility of nonlinear response like that reported here, pre-emptive adaptation of management strategies may increase efficacy of biodiversity conservation by allowing behavior modification prior to precipitous

  1. Weak average persistence and extinction of a predator-prey system in a polluted environment with impulsive toxicant input

    International Nuclear Information System (INIS)

    Yang Xiaofeng; Jin Zhen; Xue Yakui

    2007-01-01

    In this paper, we have investigated a predator-prey system in a polluted environment with impulsive toxicant input at fixed moments. We have obtained two thresholds on the impulsive period by assuming the toxicant amount input is fixed to the environment at each pulse moment. If the impulsive period is greater than the big threshold, then both populations are weak average persistent. If the period lies between of the two thresholds, then the prey population will be weak average persistent while the predator population extinct. If the period is less than the small threshold, both populations tend to extinction. Finally, our theoretical results are confirmed by own numerical simulations

  2. Changing MFTF vacuum environment

    International Nuclear Information System (INIS)

    Margolies, D.; Valby, L.

    1982-12-01

    The Mirror Fusion Test Facility (MFTF) vacuum vessel will be about 60m long and 10m in diameter at the widest point. The allowable operating densities range from 2 x 10 9 to 5 x 10 10 particles per cc. The maximum leak rate of 10 - 6 tl/sec is dominated during operation by the deliberately injected cold gas of 250 tl/sec. This gas is pumped by over 1000 square meters of cryopanels, external sorption pumps and getters. The design and requirements have changed radically over the past several years, and they are still not in final form. The vacuum system design has also changed, but more slowly and less radically. This paper discusses the engineering effort necessary to meet these stringent and changing requirements. Much of the analysis of the internal systems has been carried out using a 3-D Monte Carlo computer code, which can estimate time dependent operational pressures. This code and its use will also be described

  3. Changing MFTF vacuum environment

    International Nuclear Information System (INIS)

    Margolies, D.; Valby, L.

    1982-01-01

    The Mirror Fusion Test Facility (MFTF) vaccum vessel will be about 60m long and 10m in diameter at the widest point. The allowable operating densities range from 2 x 10 9 to 5 x 10 10 particles per cc. The maximum leak rate of 10 -6 tl/sec is dominated during operation by the deliberately injected cold gas of 250 tl/sec. This gas is pumped by over 1000 square meters of cryopanels, external sorbtion pumps and getters. The design and requirements have changed radically over the past several years, and they are still not in final form. The vacuum system design has also changed, but more slowly and less radically. This paper discusses the engineering effort necessary to meet these stringent and changing requirements. Much of the analysis of the internal systems has been carried out using a 3-D Monte Carlo computer code, which can estimate time dependent operational pressures. This code and its use will also be described

  4. Contextual change after fear acquisition affects conditioned responding and the time course of extinction learning – Implications for renewal research

    Directory of Open Access Journals (Sweden)

    Rachel eSjouwerman

    2015-12-01

    Full Text Available Context plays a central role in retrieving (fear memories. Accordingly, context manipulations are inherent to most return of fear (ROF paradigms (in particular renewal, involving contextual changes after fear extinction. Context changes are, however, also often embedded during earlier stages of ROF experiments such as context changes between fear acquisition and extinction (e.g. in ABC and ABA renewal. Previous studies using these paradigms have however focused exclusively on the context switch after extinction (i.e. renewal. Thus, the possibility of a general effect of a context switch on conditioned responding that may not be conditional to preceding extinction learning remains unstudied.Hence, the current study investigated the impact of a context switch between fear acquisition and extinction on immediate conditioned responding and on the time-course of extinction learning by using a multimodal approach. A group that underwent contextual change after fear conditioning (AB; n = 36 was compared with a group without a contextual change from acquisition to extinction (AA; n = 149, while measuring autonomic (skin conductance and fear potentiated startle measures and subjective fear ratings. Contextual change between fear acquisition and extinction had a pronounced effect on both immediate conditioned responding and on the time course of extinction learning in skin conductance responses and subjective fear ratings. This may have important implications for the mechanisms underlying and the interpretation of the renewal effect (i.e. contextual switch after extinction. Consequently, future studies should incorporate designs and statistical tests that disentangle general effects of contextual change from genuine ROF effects.

  5. Neural changes in extinction recall following prolonged exposure treatment for PTSD: A longitudinal fMRI study

    Directory of Open Access Journals (Sweden)

    Liat Helpman, PhD

    2016-01-01

    Conclusions: Prolonged exposure treatment appears to alter neural activation in PTSD patients during recall of fear extinction, and change in extinction recall (measured by SCR is associated with symptom reduction. We discuss results in the context of neural systems involved in response to affective stimuli.

  6. Persistence and extinction of a stochastic single-specie model under regime switching in a polluted environment.

    Science.gov (United States)

    Liu, Meng; Wang, Ke

    2010-06-07

    A new single-species model disturbed by both white noise and colored noise in a polluted environment is developed and analyzed. Sufficient criteria for extinction, stochastic nonpersistence in the mean, stochastic weak persistence in the mean, stochastic strong persistence in the mean and stochastic permanence of the species are established. The threshold between stochastic weak persistence in the mean and extinction is obtained. The results show that both white and colored environmental noises have sufficient effect to the survival results. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  7. Are Humans too Numerous to Become Extinct?

    OpenAIRE

    Cairns, John

    2009-01-01

    Some claim that humans are too numerous to become extinct. However, passenger pigeon, once the most numerous birds on the planet, are now extinct. For years, humankind has been damaging its habitat, discharging toxic chemicals into the environment, and having harmful effects on agricultural productivity due to climate change. Humankind s extinction depends on the continuation of various human activities including economic growth, addiction to fossil fuel, over consumption, overpopulation, oc...

  8. Local extinction and colonisation in native and exotic fish in relation to changes in land use

    OpenAIRE

    Kopp , Dorothée; Figuerola , Jordi; Compin , Arthur; Santoul , Frédéric; Céréghino , Régis

    2011-01-01

    International audience; Distribution patterns of many native and exotic fish species are well documented, yet little is known about the temporal dynamics of native and exotic diversity in relation to changes in land use. We hypothesised that colonisation rates would be higher for exotic fish species and that extinction rates would be higher for native species in large stream systems. We also predicted that cold-water species would be more impacted than thermally tolerant species. To test thes...

  9. Climate change, environment and development

    OpenAIRE

    Okereke, Chukwumerije; Massaquoi, Abu-Bakar S.

    2017-01-01

    Climate change, a quintessential environmental problem, is generally recognised as the most important development challenge in the 21st century (IPCC, 2014). In addition to acknowledging its many significant direct consequences, climate change is increasingly used to frame discussions on other important global challenges, such as health, energy and food security. This chapter provides understanding of the intricate and complex relationship between climate change, environment and development.

  10. 'Tales of Symphonia': extinction dynamics in response to past climate change in Madagascan rainforests.

    Science.gov (United States)

    Virah-Sawmy, Malika; Bonsall, Michael B; Willis, Katherine J

    2009-12-23

    Madagascar's rainforests are among the most biodiverse in the world. Understanding the population dynamics of important species within these forests in response to past climatic variability provides valuable insight into current and future species composition. Here, we use a population-level approach to analyse palaeoecological records over the last 5300 years to understand how populations of Symphonia cf. verrucosa became locally extinct in some rainforest fragments along the southeast coast of Madagascar in response to rapid climate change, yet persisted in others. Our results indicate that regional (climate) variability contributed to synchronous decline of S. cf. verrucosa populations in these forests. Superimposed on regional fluctuations were local processes that could have contributed or mitigated extinction. Specifically, in the forest with low soil nutrients, population model predictions indicated that there was coexistence between S. cf. verrucosa and Erica spp., but in the nutrient-rich forest, interspecific effects between Symphonia and Erica spp. may have pushed Symphonia to extinction at the peak of climatic change. We also demonstrate that Symphonia is a good indicator of a threshold event, exhibiting erratic fluctuations prior to and long after the critical climatic point has passed.

  11. Ecological changes in Coyotes (Canis latrans in response to the ice age megafaunal extinctions.

    Directory of Open Access Journals (Sweden)

    Julie A Meachen

    Full Text Available Coyotes (Canis latrans are an important species in human-inhabited areas. They control pests and are the apex predators in many ecosystems. Because of their importance it is imperative to understand how environmental change will affect this species. The end of the Pleistocene Ice Age brought with it many ecological changes for coyotes and here we statistically determine the changes that occurred in coyotes, when these changes occurred, and what the ecological consequences were of these changes. We examined the mandibles of three coyote populations: Pleistocene Rancho La Brean (13-29 Ka, earliest Holocene Rancho La Brean (8-10 Ka, and Recent from North America, using 2D geometric morphometrics to determine the morphological differences among them. Our results show that these three populations were morphologically distinct. The Pleistocene coyotes had an overall robust mandible with an increased shearing arcade and a decreased grinding arcade, adapted for carnivory and killing larger prey; whereas the modern populations show a gracile morphology with a tendency toward omnivory or grinding. The earliest Holocene populations are intermediate in morphology and smallest in size. These findings indicate that a niche shift occurred in coyotes at the Pleistocene/Holocene boundary - from a hunter of large prey to a small prey/more omnivorous animal. Species interactions between Canis were the most likely cause of this transition. This study shows that the Pleistocene extinction event affected species that did not go extinct as well as those that did.

  12. Extinction of mammalian populations in conservation units of the Brazilian Cerrado by inbreeding depression in stochastic environments

    OpenAIRE

    Silva, Marcel Müller Fernandes Pereira da; Diniz-Filho, José Alexandre Felizola

    2008-01-01

    Despite methodological and theoretical advances in conservation genetics, data on genetic variation on broad regional spatial scales are still scarce, leading conservation planners to use general heuristic or simulation models for an integrated analysis of genetic, demographic and landscape parameters. Here, we extended previous results by evaluating spatial patterns of extinction by inbreeding depression under stochastic variation of environments for mammalian populations in 31 conservation ...

  13. Differential influences of allometry, phylogeny and environment on the rostral shape diversity of extinct South American notoungulates

    Science.gov (United States)

    Gomes Rodrigues, Helder; Cornette, Raphaël; Clavel, Julien; Cassini, Guillermo; Bhullar, Bhart-Anjan S.; Fernández-Monescillo, Marcos; Moreno, Karen; Herrel, Anthony; Billet, Guillaume

    2018-01-01

    Understanding the mechanisms responsible for phenotypic diversification, and the associated underlying constraints and ecological factors represents a central issue in evolutionary biology. Mammals present a wide variety of sizes and shapes, and are characterized by a high number of morphological convergences that are hypothesized to reflect similar environmental pressures. Extinct South American notoungulates evolved in isolation from northern mammalian faunas in highly disparate environments. They present a wide array of skeletal phenotypes and convergences, such as ever-growing dentition. Here, we focused on the origins of the rostral diversity of notoungulates by quantifying the shape of 26 genera using three-dimensional geometric morphometric analysis. We tested the influence of allometry and phylogeny on rostral shape and evaluated rates of evolutionary change in the different clades. We found strong allometric and phylogenetic signals concerning the rostral shape of notoungulates. Despite convergent forms, we observed a diffuse diversification of rostral shape, with no significant evidence of influence by large-scaled environmental variation. This contrasts with the increase in dental crown height that occurred in four late-diverging families in response to similar environmental pressures. These results illustrate the importance of considering both biological components and evolutionary rates to better understand some aspects of phenotypic diversity.

  14. The changing role of mammal life histories in Late Quaternary extinction vulnerability on continents and islands.

    Science.gov (United States)

    Lyons, S Kathleen; Miller, Joshua H; Fraser, Danielle; Smith, Felisa A; Boyer, Alison; Lindsey, Emily; Mychajliw, Alexis M

    2016-06-01

    Understanding extinction drivers in a human-dominated world is necessary to preserve biodiversity. We provide an overview of Quaternary extinctions and compare mammalian extinction events on continents and islands after human arrival in system-specific prehistoric and historic contexts. We highlight the role of body size and life-history traits in these extinctions. We find a significant size-bias except for extinctions on small islands in historic times. Using phylogenetic regression and classification trees, we find that while life-history traits are poor predictors of historic extinctions, those associated with difficulty in responding quickly to perturbations, such as small litter size, are good predictors of prehistoric extinctions. Our results are consistent with the idea that prehistoric and historic extinctions form a single continuing event with the same likely primary driver, humans, but the diversity of impacts and affected faunas is much greater in historic extinctions. © 2016 The Author(s).

  15. Contrasting microbial community changes during mass extinctions at the Middle/Late Permian and Permian/Triassic boundaries

    Science.gov (United States)

    Xie, Shucheng; Algeo, Thomas J.; Zhou, Wenfeng; Ruan, Xiaoyan; Luo, Genming; Huang, Junhua; Yan, Jiaxin

    2017-02-01

    Microbial communities are known to expand as a result of environmental deterioration during mass extinctions, but differences in microbial community changes between extinction events and their underlying causes have received little study to date. Here, we present a systematic investigation of microbial lipid biomarkers spanning ∼20 Myr (Middle Permian to Early Triassic) at Shangsi, South China, to contrast microbial changes associated with the Guadalupian-Lopingian boundary (GLB) and Permian-Triassic boundary (PTB) mass extinctions. High-resolution analysis of the PTB crisis interval reveals a distinct succession of microbial communities based on secular variation in moretanes, 2-methylhopanes, aryl isoprenoids, steranes, n-alkyl cyclohexanes, and other biomarkers. The first episode of the PTB mass extinction (ME1) was associated with increases in red algae and nitrogen-fixing bacteria along with evidence for enhanced wildfires and elevated soil erosion, whereas the second episode was associated with expansions of green sulfur bacteria, nitrogen-fixing bacteria, and acritarchs coinciding with climatic hyperwarming, ocean stratification, and seawater acidification. This pattern of microbial community change suggests that marine environmental deterioration was greater during the second extinction episode (ME2). The GLB shows more limited changes in microbial community composition and more limited environmental deterioration than the PTB, consistent with differences in species-level extinction rates (∼71% vs. 90%, respectively). Microbial biomarker records have the potential to refine our understanding of the nature of these crises and to provide insights concerning possible outcomes of present-day anthropogenic stresses on Earth's ecosystems.

  16. Extinction and the fossil record

    Science.gov (United States)

    Sepkoski, J. J. Jr; Sepkoski JJ, ,. J. r. (Principal Investigator)

    1994-01-01

    The author examines evidence of mass extinctions in the fossil record and searches for reasons for such large extinctions. Five major mass extinctions eliminated at least 40 percent of animal genera in the oceans and from 65 to 95 percent of ocean species. Questions include the occurrence of gradual or catastrophic extinctions, causes, environment, the capacity of a perturbation to cause extinctions each time it happens, and the possibility and identification of complex events leading to a mass extinction.

  17. Diminishing returns: the influence of experience and environment on time-memory extinction in honey bee foragers.

    Science.gov (United States)

    Moore, Darrell; Van Nest, Byron N; Seier, Edith

    2011-06-01

    Classical experiments demonstrated that honey bee foragers trained to collect food at virtually any time of day will return to that food source on subsequent days with a remarkable degree of temporal accuracy. This versatile time-memory, based on an endogenous circadian clock, presumably enables foragers to schedule their reconnaissance flights to best take advantage of the daily rhythms of nectar and pollen availability in different species of flowers. It is commonly believed that the time-memory rapidly extinguishes if not reinforced daily, thus enabling foragers to switch quickly from relatively poor sources to more productive ones. On the other hand, it is also commonly thought that extinction of the time-memory is slow enough to permit foragers to 'remember' the food source over a day or two of bad weather. What exactly is the time-course of time-memory extinction? In a series of field experiments, we determined that the level of food-anticipatory activity (FAA) directed at a food source is not rapidly extinguished and, furthermore, the time-course of extinction is dependent upon the amount of experience accumulated by the forager at that source. We also found that FAA is prolonged in response to inclement weather, indicating that time-memory extinction is not a simple decay function but is responsive to environmental changes. These results provide insights into the adaptability of FAA under natural conditions.

  18. Learning and extinction of conditioned hearing sensation change in the beluga whale (Delphinapterus leucas).

    Science.gov (United States)

    Nachtigall, Paul E; Supin, Alexander Ya; Estaban, Jose-Antonio; Pacini, Aude F

    2016-02-01

    Ice-dwelling beluga whales are increasingly being exposed to anthropogenic loud sounds. Beluga's hearing sensitivity measured during a warning sound just preceding a loud sound was tested using pip-train stimuli and auditory evoked potential recording. When the test/warning stimulus with a frequency of 32 or 45 kHz preceded the loud sound with a frequency of 32 kHz and a sound pressure level of 153 dB re 1 μPa, 2 s, hearing thresholds before the loud sound increased relative to the baseline. The threshold increased up to 15 dB for the test frequency of 45 kHz and up to 13 dB for the test frequency of 32 kHz. These threshold increases were observed during two sessions of 36 trials each. Extinction tests revealed no change during three experimental sessions followed by a jump-like return to baseline thresholds. The low exposure level producing the hearing-dampening effect (156 dB re 1 µPa(2)s in each trial), and the manner of extinction, may be considered as evidence that the observed hearing threshold increases were a demonstration of conditioned dampening of hearing when the whale anticipated the quick appearance of a loud sound in the same way demonstrated in the false killer whale and bottlenose dolphin.

  19. Global iridium anomaly, mass extinction, and redox change at the Devonian-Carboniferous boundary

    Energy Technology Data Exchange (ETDEWEB)

    Wang, K. (Geological Survey of Canada, Calgary, Alberta (Canada) Univ. of Calgary, Alberta (Canada)); Attrep, M. Jr.; Orth, C.J. (Los Alamos National Lab., NM (United States))

    1993-12-01

    Iridium abundance anomalies have been found on a global scale in the Devonian-Carboniferous (D-C) boundary interval, which records one of the largest Phanerozoic mass-extinction events, an event that devastated many groups of living organisms, such as plants, ammonoids, trilobites, conodonts, fish, foraminiferans, brachiopods, and ostracodes. At or very close to the D-C boundary, there exists a geographically widespread black-shale interval, and Ir abundances reach anomalous maxima of 0.148 ppb (Montagne Noire, France), 0.138 ppb (Alberta, Canada) 0.140 ppb (Carnic Alps, Austria), 0.156 ppb (Guangxi, China), 0.258 ppb (Guizhou, China), and 0.250 ppb (Oklahoma). The discovery of global D-C Ir anomalies argues for an impact-extinction model. However, nonchondritic ratios of Ir to other important elements and a lack of physical evidence (shocked quartz, microtektites) do not support such a scenario. The fact that all Ir abundance maxima are at sharp redox boundaries in these sections leads us to conclude that the Ir anomalies likely resulted from a sudden change in paleo-redox conditions during deposition and/or early diagenesis. 36 refs., 2 figs., 1 tab.

  20. Redox conditions and marine microbial community changes during the end-Ordovician mass extinction event

    Science.gov (United States)

    Smolarek, Justyna; Marynowski, Leszek; Trela, Wiesław; Kujawski, Piotr; Simoneit, Bernd R. T.

    2017-02-01

    The end-Ordovician (Hirnantian) crisis is the first globally distinct extinction during the Phanerozoic, but its causes are still not fully known. Here, we present an integrated geochemical and petrographic analysis to understand the sedimentary conditions taking place before, during and after the Late Ordovician ice age. New data from the Zbrza (Holy Cross Mountains) and Gołdap (Baltic Depression) boreholes shows that, like in other worldwide sections, the total organic carbon (TOC) content is elevated in the upper Katian and uppermost Hirnantian to Rhudannian black shales, but depleted (below 1%) during most of the Hirnantian. Euxinic conditions occurred in the photic zone in both TOC-rich intervals. This is based on the maleimide distribution, occurrence of aryl isoprenoids and isorenieratane, as well as a dominance of tiny pyrite framboids. Euxinic conditions were interrupted by the Hirnantian regression caused by glaciation. Sedimentation on the deep shelf changed to aerobic probably due to intense thermohaline circulation. Euxinia in the water column occurred directly during the time associated with the second pulse of the mass extinction with a termination of the end-Ordovician glaciation and sea level rise just at the Ordovician/Silurian (O/S) boundary. In contrast, we suggest based on inorganic proxies that bottom water conditions were generally oxic to dysoxic due to upwelling in the Rheic Ocean. The only episode of seafloor anoxia in the Zbrza basin was found at the O/S boundary, where all inorganic indicators showed elevated values typical for anoxia (U/Th > 1.25; V/Cr > 4.25; V/(V + Ni): 0.54-0.82 and Mo > 10-25 ppm). Significant differences in hopanes to steranes ratio and in C27-C29 sterane distribution between the Katian, Rhudannian and Hirnantian deposits indicate changes in marine microbial communities triggered by sharp climate change and Gondwana glaciation. The increase from biomarkers of cyanobacteria (2α-methylhopanes) after the O

  1. Extinction transition in stochastic population dynamics in a random, convective environment

    International Nuclear Information System (INIS)

    Juhász, Róbert

    2013-01-01

    Motivated by modeling the dynamics of a population living in a flowing medium where the environmental factors are random in space, we have studied an asymmetric variant of the one-dimensional contact process, where the quenched random reproduction rates are systematically greater in one direction than in the opposite one. The spatial disorder turns out to be a relevant perturbation but, according to results of Monte Carlo simulations, the behavior of the model at the extinction transition is different from the (infinite-randomness) critical behavior of the disordered symmetric contact process. Depending on the strength a of the asymmetry, the critical population drifts either with a finite velocity or with an asymptotically vanishing velocity as x(t) ∼ t μ(a) , where μ(a) < 1. Dynamical quantities are non-self-averaging at the extinction transition; the survival probability, for instance, shows multiscaling, i.e. it is characterized by a broad spectrum of effective exponents. For a sufficiently weak asymmetry, a Griffiths phase appears below the extinction transition, where the survival probability decays as a non-universal power of the time while, above the transition, another extended phase emerges, where the front of the population advances anomalously with a diffusion exponent continuously varying with the control parameter. (paper)

  2. The Relative Impact of Climate Change on the Extinction Risk of Tree Species in the Montane Tropical Andes.

    Science.gov (United States)

    Tejedor Garavito, Natalia; Newton, Adrian C; Golicher, Duncan; Oldfield, Sara

    2015-01-01

    There are widespread concerns that anthropogenic climate change will become a major cause of global biodiversity loss. However, the potential impact of climate change on the extinction risk of species remains poorly understood, particularly in comparison to other current threats. The objective of this research was to examine the relative impact of climate change on extinction risk of upper montane tree species in the tropical Andes, an area of high biodiversity value that is particularly vulnerable to climate change impacts. The extinction risk of 129 tree species endemic to the region was evaluated according to the IUCN Red List criteria, both with and without the potential impacts of climate change. Evaluations were supported by development of species distribution models, using three methods (generalized additive models, recursive partitioning, and support vector machines), all of which produced similarly high AUC values when averaged across all species evaluated (0.82, 0.86, and 0.88, respectively). Inclusion of climate change increased the risk of extinction of 18-20% of the tree species evaluated, depending on the climate scenario. The relative impact of climate change was further illustrated by calculating the Red List Index, an indicator that shows changes in the overall extinction risk of sets of species over time. A 15% decline in the Red List Index was obtained when climate change was included in this evaluation. While these results suggest that climate change represents a significant threat to tree species in the tropical Andes, they contradict previous suggestions that climate change will become the most important cause of biodiversity loss in coming decades. Conservation strategies should therefore focus on addressing the multiple threatening processes currently affecting biodiversity, rather than focusing primarily on potential climate change impacts.

  3. Pollinator declines. Extinctions of aculeate pollinators in Britain and the role of large-scale agricultural changes.

    Science.gov (United States)

    Ollerton, Jeff; Erenler, Hilary; Edwards, Mike; Crockett, Robin

    2014-12-12

    Pollinators are fundamental to maintaining both biodiversity and agricultural productivity, but habitat destruction, loss of flower resources, and increased use of pesticides are causing declines in their abundance and diversity. Using historical records, we assessed the rate of extinction of bee and flower-visiting wasp species in Britain from the mid-19th century to the present. The most rapid phase of extinction appears to be related to changes in agricultural policy and practice beginning in the 1920s, before the agricultural intensification prompted by the Second World War, often cited as the most important driver of biodiversity loss in Britain. Slowing of the extinction rate from the 1960s onward may be due to prior loss of the most sensitive species and/or effective conservation programs. Copyright © 2014, American Association for the Advancement of Science.

  4. A scenario for impacts of water availability loss due to climate change on riverine fish extinction rates

    NARCIS (Netherlands)

    Tedesco, P.A.; Oberdorff, T.; Cornu, J.-F.; Beauchard, O.; Brosse, S.; Dürr, H.H.; Grenouillet, G.; Leprieur, F.; Tisseuil, C.; Zaiss, R.; Hugueny, B.

    2013-01-01

    1. Current models estimating impact of habitat loss on biodiversity in the face of global climate change usually project only percentages of species committed to extinction' on an uncertain time-scale. Here, we show that this limitation can be overcome using an empirically derived background

  5. Future habitat loss and extinctions driven by land-use change in biodiversity hotspots under four scenarios of climate-change mitigation.

    Science.gov (United States)

    Jantz, Samuel M; Barker, Brian; Brooks, Thomas M; Chini, Louise P; Huang, Qiongyu; Moore, Rachel M; Noel, Jacob; Hurtt, George C

    2015-08-01

    Numerous species have been pushed into extinction as an increasing portion of Earth's land surface has been appropriated for human enterprise. In the future, global biodiversity will be affected by both climate change and land-use change, the latter of which is currently the primary driver of species extinctions. How societies address climate change will critically affect biodiversity because climate-change mitigation policies will reduce direct climate-change impacts; however, these policies will influence land-use decisions, which could have negative impacts on habitat for a substantial number of species. We assessed the potential impact future climate policy could have on the loss of habitable area in biodiversity hotspots due to associated land-use changes. We estimated past extinctions from historical land-use changes (1500-2005) based on the global gridded land-use data used for the Intergovernmental Panel on Climate Change Fifth Assessment Report and habitat extent and species data for each hotspot. We then estimated potential extinctions due to future land-use changes under alternative climate-change scenarios (2005-2100). Future land-use changes are projected to reduce natural vegetative cover by 26-58% in the hotspots. As a consequence, the number of additional species extinctions, relative to those already incurred between 1500 and 2005, due to land-use change by 2100 across all hotspots ranged from about 220 to 21000 (0.2% to 16%), depending on the climate-change mitigation scenario and biological factors such as the slope of the species-area relationship and the contribution of wood harvest to extinctions. These estimates of potential future extinctions were driven by land-use change only and likely would have been higher if the direct effects of climate change had been considered. Future extinctions could potentially be reduced by incorporating habitat preservation into scenario development to reduce projected future land-use changes in hotspots or by

  6. Woody encroachment over 70 years in South African savannahs: overgrazing, global change or extinction aftershock?

    Science.gov (United States)

    Stevens, Nicola; Erasmus, B F N; Archibald, S; Bond, W J

    2016-09-19

    Woody encroachment in 'open' biomes like grasslands and savannahs is occurring globally. Both local and global drivers, including elevated CO2, have been implicated in these increases. The relative importance of different processes is unresolved as there are few multi-site, multi-land-use evaluations of woody plant encroachment. We measured 70 years of woody cover changes over a 1020 km(2) area covering four land uses (commercial ranching, conservation with elephants, conservation without elephants and communal rangelands) across a rainfall gradient in South African savannahs. Different directions of woody cover change would be expected for each different land use, unless a global factor is causing the increases. Woody cover change was measured between 1940 and 2010 using the aerial photo record. Detection of woody cover from each aerial photograph was automated using eCognitions' Object-based image analysis (OBIA). Woody cover doubled in all land uses across the rainfall gradient, except in conservation areas with elephants in low-rainfall savannahs. Woody cover in 2010 in low-rainfall savannahs frequently exceeded the maximum woody cover threshold predicted for African savannahs. The results indicate that a global factor, of which elevated CO2 is the likely candidate, may be driving encroachment. Elephants in low-rainfall savannahs prevent encroachment and localized megafaunal extinction is a probable additional cause of encroachment.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'. © 2016 The Author(s).

  7. Live Fast, Die Young: Experimental Evidence of Population Extinction Risk due to Climate Change

    Science.gov (United States)

    Bestion, Elvire; Teyssier, Aimeric; Richard, Murielle; Clobert, Jean; Cote, Julien

    2015-01-01

    Evidence has accumulated in recent decades on the drastic impact of climate change on biodiversity. Warming temperatures have induced changes in species physiology, phenology, and have decreased body size. Such modifications can impact population dynamics and could lead to changes in life cycle and demography. More specifically, conceptual frameworks predict that global warming will severely threaten tropical ectotherms while temperate ectotherms should resist or even benefit from higher temperatures. However, experimental studies measuring the impacts of future warming trends on temperate ectotherms' life cycle and population persistence are lacking. Here we investigate the impacts of future climates on a model vertebrate ectotherm species using a large-scale warming experiment. We manipulated climatic conditions in 18 seminatural populations over two years to obtain a present climate treatment and a warm climate treatment matching IPCC predictions for future climate. Warmer temperatures caused a faster body growth, an earlier reproductive onset, and an increased voltinism, leading to a highly accelerated life cycle but also to a decrease in adult survival. A matrix population model predicts that warm climate populations in our experiment should go extinct in around 20 y. Comparing our experimental climatic conditions to conditions encountered by populations across Europe, we suggest that warming climates should threaten a significant number of populations at the southern range of the distribution. Our findings stress the importance of experimental approaches on the entire life cycle to more accurately predict population and species persistence in future climates. PMID:26501958

  8. Extinction of canid populations by inbreeding depression under stochastic environments in Southwestern Goiás State: a simulation study

    Directory of Open Access Journals (Sweden)

    Flávia Melo Rodrigues

    2007-01-01

    Full Text Available A frequently addressed question in conservation biology is what is the chance of survival for a population for a given number of years under certain conditions of habitat loss and human activities. This can be estimated through an integrated analysis of genetic, demographic and landscape processes, which allows the prediction of more realistic and precise models of population persistence. In this study, we modeled extinction in stochastic environments under inbreeding depression for two canid species, the maned wolf (Chrysocyon brachiurus and the crab-eating fox (Cerdocyon thous, in southwest Goiás State. Genetic parameters were obtained from six microsattelite loci (Short Tandem Repeats - STR, which allowed estimates of inbreeding levels and of the effective population size under a stepwise mutation model based on heterozygosis. The simulations included twelve alternative scenarios with varying rates of habitat loss, magnitude of population fluctuation and initial inbreeding levels. ANOVA analyses of the simulation results showed that times to extinction were better explained by demographic parameters. Times to extinction ranged from 352 to 844, in the worst and best scenario, respectively, for the large-bodied maned wolf. For the small-bodied crab-eating fox, these same estimates were 422 and 974 years. Simulations results are within the expectation based on knowledge about species' life history, genetics and demography. They suggest that populations can persist through a reasonable time (i.e., more than 200 years even under the worst demographic scenario. Our analyses are a starting point for a more focused evaluation of persistence in these populations. Our results can be used in future research aiming at obtaining better estimates of parameters that may, in turn, be used to achieve more appropriate and realist population viability models at a regional scale.

  9. Climate change consequences for the indoor environment

    NARCIS (Netherlands)

    Ariës, M.B.C.; Bluyssen, P.M.

    2009-01-01

    Scientists warn us about climate change and its effects on the outdoor environment. These effects can have significant consequences for the indoor environment, also in the Netherlands. Climate changes will affect different aspects of the indoor environment as well as the stakeholders of that indoor

  10. Extinction risks forced by climatic change and intraspecific variation in the thermal physiology of a tropical lizard.

    Science.gov (United States)

    Pontes-da-Silva, Emerson; Magnusson, William E; Sinervo, Barry; Caetano, Gabriel H; Miles, Donald B; Colli, Guarino R; Diele-Viegas, Luisa M; Fenker, Jessica; Santos, Juan C; Werneck, Fernanda P

    2018-04-01

    Temperature increases can impact biodiversity and predicting their effects is one of the main challenges facing global climate-change research. Ectotherms are sensitive to temperature change and, although predictions indicate that tropical species are highly vulnerable to global warming, they remain one of the least studied groups with respect to the extent of physiological variation and local extinction risks. We model the extinction risks for a tropical heliothermic teiid lizard (Kentropyx calcarata) integrating previously obtained information on intraspecific phylogeographic structure, eco-physiological traits and contemporary species distributions in the Amazon rainforest and its ecotone to the Cerrado savannah. We also investigated how thermal-biology traits vary throughout the species' geographic range and the consequences of such variation for lineage vulnerability. We show substantial variation in thermal tolerance of individuals among thermally distinct sites. Thermal critical limits were highly correlated with operative environmental temperatures. Our physiological/climatic model predicted relative extinction risks for local populations within clades of K. calcarata for 2050 ranging between 26.1% and 70.8%, while for 2070, extinction risks ranged from 52.8% to 92.8%. Our results support the hypothesis that tropical-lizard taxa are at high risk of local extinction caused by increasing temperatures. However, the thermo-physiological differences found across the species' distribution suggest that local adaptation may allow persistence of this tropical ectotherm in global warming scenarios. These results will serve as basis to further research to investigate the strength of local adaptation to climate change. Persistence of Kentropyx calcarata also depends on forest preservation, but the Amazon rainforest is currently under high deforestation rates. We argue that higher conservation priority is necessary so the Amazon rainforest can fulfill its capacity to

  11. Brachiopod faunas after the end Ordovician mass extinction from South China: Testing ecological change through a major taxonomic crisis

    Science.gov (United States)

    Huang, Bing; Harper, David A. T.; Rong, Jiayu; Zhan, Renbin

    2017-05-01

    Classification of extinction events and their severity is generally based on taxonomic counts. The ecological impacts of such events have been categorized and prioritized but rarely tested with empirical data. The ecology of the end Ordovician extinction and subsequent biotic recovery is tracked through abundant and diverse brachiopod faunas in South China. The spatial and temporal ranges of some 6500 identified specimens, from 10 collections derived from six localities were investigated by network and cluster analyses, nonmetric multidimensional scaling and a species abundance model. Depth zonations and structure of brachiopod assemblages along an onshore-offshore gradient in the late Katian were similar to those in the latest Ordovician-earliest Silurian (post-extinction fauna). Within this ecological framework, deeper-water faunas are partly replaced by new taxa; siliciclastic substrates continued to be dominated by the more 'Ordovician' orthides and strophomenides, shallow-water carbonate environments hosted atrypides, athyridides and pentamerides, with the more typical Ordovician brachiopod fauna continuing to dominate until the late Rhuddanian. The end Ordovician extinctions tested the resilience of the brachiopod fauna without damage to its overall ecological structure; that commenced later at the end of the Rhuddanian.

  12. Old Theories versus Changing Environment,

    Science.gov (United States)

    1973-10-01

    necessary. According to Herzberg, the classical approach to motivating personnel has con - ? cermed itself with the employee’s environment or the...factors will keep him from complaining; however, they will not make him work harder or more effec- tively. It’s sort of the "gold-plated sweatshop

  13. Persistence and extinction of a single-species population system in a polluted environment with random perturbations and impulsive toxicant input

    International Nuclear Information System (INIS)

    Liu Meng; Wang Ke

    2012-01-01

    Highlights: ► Random population model with pulse toxicant input in polluted environments. ► Threshold between persistence and extinction is obtained. ► Different random noises have different effects on the persistence of the population. ► Impulsive period plays a key role in determining persistence of the population. ► Simulation figures support the analytical findings. - Abstract: Taking both white noises and colored noises into account, a stochastic single-species model with Markov switching and impulsive toxicant input in a polluted environment is proposed and investigated. Sufficient conditions for extinction, non-persistence in the mean, weak persistence and stochastic permanence are established. The threshold between weak persistence and extinction is obtained. Some simulation figures are introduced to illustrate the main results.

  14. Author Correction: Intergenerational equity can help to prevent climate change and extinction.

    Science.gov (United States)

    Treves, Adrian; Artelle, Kyle A; Darimont, Chris T; Lynn, William S; Paquet, Paul; Santiago-Ávila, Francisco J; Shaw, Rance; Wood, Mary C

    2018-05-01

    The original Article mistakenly coded the constitutional rights of Australia as containing a governmental duty to protect the environment (blue in the figures); this has been corrected to containing no explicit mention of environmental protection (orange in the figures). The original Article also neglected to code the constitutional rights of the Cayman Islands (no data; yellow in the figures); this has been corrected to containing a governmental duty to protect the environment (blue in the figures).Although no inferences changed as a result of these errors, many values changed slightly and have been corrected. The proportion of the world's nations having constitutional rights to a healthy environment changed from 75% to 74%. The proportions of nations in different categories given in the Fig. 1 caption all changed except purple countries (3.1%): green countries changed from 47.2% to 46.9%; blue countries changed from 24.4% to 24.2%; and orange countries changed from 25.3% to 25.8%. The proportion of the global atmospheric CO 2 emitted by the 144 nations changed from 72.6% to 74.4%; the proportion of the world's population represented by the 144 nations changed from 84.9% to 85%. The values of annual average CO 2 emissions for blue countries changed from 363,000 Gg to 353,000 Gg and for orange countries from 195,000 Gg to 201,000 Gg. The proportion of threatened mammals endemic to a single country represented by the 144 countries changed from 91% to 84%. Figures 1-3 have been updated to show the correct values and map colours and the Supplementary Information has been updated to give the correct country codes.

  15. Changing international environments, business environments and energy environments

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Shunsuke

    1987-04-01

    Japan has grown up to an economic superpower with more than 10% of the world GNP. This means that Japan should bear a role to be a member to explore and contribute to the world of the future. In order to attain this, it is necessary to examine how the enterprises which are promoting and leading the Japanese economy are changing. It is also important to consider what Japan can contribute to the world, on the basis of the past experience as a minor power in the natural resources and the energy. (4 figs, 1 tab)

  16. Biological Extinction in Earth History

    Science.gov (United States)

    Raup, David M.

    1986-03-01

    Virtually all plant and animal species that have ever lived on the earth are extinct. For this reason alone, extinction must play an important role in the evolution of life. The five largest mass extinctions of the past 600 million years are of greatest interest, but there is also a spectrum of smaller events, many of which indicate biological systems in profound stress. Extinction may be episodic at all scales, with relatively long periods of stability alternating with short-lived extinction events. Most extinction episodes are biologically selective, and further analysis of the victims and survivors offers the greatest chance of deducing the proximal causes of extinction. A drop in sea level and climatic change are most frequently invoked to explain mass extinctions, but new theories of collisions with extraterrestrial bodies are gaining favor. Extinction may be constructive in a Darwinian sense or it may only perturb the system by eliminating those organisms that happen to be susceptible to geologically rare stresses.

  17. Biological extinction in earth history

    Science.gov (United States)

    Raup, D. M.

    1986-01-01

    Virtually all plant and animal species that have ever lived on the earth are extinct. For this reason alone, extinction must play an important role in the evolution of life. The five largest mass extinctions of the past 600 million years are of greatest interest, but there is also a spectrum of smaller events, many of which indicate biological systems in profound stress. Extinction may be episodic at all scales, with relatively long periods of stability alternating with short-lived extinction events. Most extinction episodes are biologically selective, and further analysis of the victims and survivors offers the greatest chance of deducing the proximal causes of extinction. A drop in sea level and climatic change are most frequently invoked to explain mass extinctions, but new theories of collisions with extraterrestrial bodies are gaining favor. Extinction may be constructive in a Darwinian sense or it may only perturb the system by eliminating those organisms that happen to be susceptible to geologically rare stresses.

  18. Changing business environment: implications for farming

    OpenAIRE

    Malcolm, Bill

    2011-01-01

    The natural, technological, economic, political and social environment in which farmers farm constantly changes. History has lessons about change in agriculture and about farmers coping with change, though the future is unknowable and thus always surprising. The implication for farm operation is to prepare, do not predict.

  19. Antarctic climate change and the environment

    Science.gov (United States)

    2009-11-01

    This volume provides a comprehensive, up-to-date account of how the physical and biological : environment of the Antarctic continent and Southern Ocean has changed from Deep Time until : the present day. It also considers how the Antarctic environmen...

  20. Impossible Extinction

    Science.gov (United States)

    Cockell, Charles S.

    2003-03-01

    Every 225 million years the Earth, and all the life on it, completes one revolution around the Milky Way Galaxy. During this remarkable journey, life is influenced by calamitous changes. Comets and asteroids strike the surface of the Earth, stars explode, enormous volcanoes erupt, and, more recently, humans litter the planet with waste. Many animals and plants become extinct during the voyage, but humble microbes, simple creatures made of a single cell, survive this journey. This book takes a tour of the microbial world, from the coldest and deepest places on Earth to the hottest and highest, and witnesses some of the most catastrophic events that life can face. Impossible Extinction tells this remarkable story to the general reader by explaining how microbes have survived on Earth for over three billion years. Charles Cockell received his doctorate from the University of Oxford, and is currently a microbiologist with rhe Search for Extraterrestrial Intelligence Institute (SETI), based at the British Antarctic Survey in Cambridge, UK. His research focusses on astrobiology, life in the extremes and the human exploration of Mars. Cockell has been on expeditions to the Arctic, Antarctic, Mongolia, and in 1993 he piloted a modified insect-collecting ultra-light aircraft over the Indonesian rainforests. He is Chair of the Twenty-one Eleven Foundation for Exploration, a charity that supports expeditions that forge links between space exploration and environmentalism.

  1. Climate Change: Science, Health and the Environment

    Centers for Disease Control (CDC) Podcasts

    Climate Change: Science, Health and the Environment Howard Frumkin, MD, DrPH, Director of CDC's National Center for Environmental Health/Agency for Toxic Substances and Disease Registry, discusses the science of climate change, the potential for shifts in the natural world to affect our wellbeing, and the challenges of emerging issues in environmental health.

  2. Rethinking Extinction

    Science.gov (United States)

    Dunsmoor, Joseph E.; Niv, Yael; Daw, Nathaniel; Phelps, Elizabeth A.

    2015-01-01

    Extinction serves as the leading theoretical framework and experimental model to describe how learned behaviors diminish through absence of anticipated reinforcement. In the past decade, extinction has moved beyond the realm of associative learning theory and behavioral experimentation in animals and has become a topic of considerable interest in the neuroscience of learning, memory, and emotion. Here, we review research and theories of extinction, both as a learning process and as a behavioral technique, and consider whether traditional understandings warrant a re-examination. We discuss the neurobiology, cognitive factors, and major computational theories, and revisit the predominant view that extinction results in new learning that interferes with expression of the original memory. Additionally, we reconsider the limitations of extinction as a technique to prevent the relapse of maladaptive behavior, and discuss novel approaches, informed by contemporary theoretical advances, that augment traditional extinction methods to target and potentially alter maladaptive memories. PMID:26447572

  3. Rethinking Extinction

    OpenAIRE

    Dunsmoor, Joseph E.; Niv, Yael; Daw, Nathaniel; Phelps, Elizabeth A.

    2015-01-01

    Extinction serves as the leading theoretical framework and experimental model to describe how learned behaviors diminish through absence of anticipated reinforcement. In the past decade, extinction has moved beyond the realm of associative learning theory and behavioral experimentation in animals and has become a topic of considerable interest in the neuroscience of learning, memory, and emotion. Here, we review research and theories of extinction, both as a learning process and as a behavior...

  4. Metapopulation extinction risk: dispersal's duplicity.

    Science.gov (United States)

    Higgins, Kevin

    2009-09-01

    Metapopulation extinction risk is the probability that all local populations are simultaneously extinct during a fixed time frame. Dispersal may reduce a metapopulation's extinction risk by raising its average per-capita growth rate. By contrast, dispersal may raise a metapopulation's extinction risk by reducing its average population density. Which effect prevails is controlled by habitat fragmentation. Dispersal in mildly fragmented habitat reduces a metapopulation's extinction risk by raising its average per-capita growth rate without causing any appreciable drop in its average population density. By contrast, dispersal in severely fragmented habitat raises a metapopulation's extinction risk because the rise in its average per-capita growth rate is more than offset by the decline in its average population density. The metapopulation model used here shows several other interesting phenomena. Dispersal in sufficiently fragmented habitat reduces a metapopulation's extinction risk to that of a constant environment. Dispersal between habitat fragments reduces a metapopulation's extinction risk insofar as local environments are asynchronous. Grouped dispersal raises the effective habitat fragmentation level. Dispersal search barriers raise metapopulation extinction risk. Nonuniform dispersal may reduce the effective fraction of suitable habitat fragments below the extinction threshold. Nonuniform dispersal may make demographic stochasticity a more potent metapopulation extinction force than environmental stochasticity.

  5. An empirical test of the relative and combined effects of land-cover and climate change on local colonization and extinction.

    Science.gov (United States)

    Yalcin, Semra; Leroux, Shawn James

    2018-04-14

    Land-cover and climate change are two main drivers of changes in species ranges. Yet, the majority of studies investigating the impacts of global change on biodiversity focus on one global change driver and usually use simulations to project biodiversity responses to future conditions. We conduct an empirical test of the relative and combined effects of land-cover and climate change on species occurrence changes. Specifically, we examine whether observed local colonization and extinctions of North American birds between 1981-85 and 2001-05 are correlated with land-cover and climate change and whether bird life history and ecological traits explain interspecific variation in observed occurrence changes. We fit logistic regression models to test the impact of physical land-cover change, changes in net primary productivity, winter precipitation, mean summer temperature, and mean winter temperature on the probability of Ontario breeding bird local colonization and extinction. Models with climate change, land-cover change, and the combination of these two drivers were the top ranked models of local colonization for 30%, 27%, and 29% of species, respectively. Conversely, models with climate change, land-cover change, and the combination of these two drivers were the top ranked models of local extinction for 61%, 7%, and 9% of species, respectively. The quantitative impacts of land-cover and climate change variables also vary among bird species. We then fit linear regression models to test whether the variation in regional colonization and extinction rate could be explained by mean body mass, migratory strategy, and habitat preference of birds. Overall, species traits were weakly correlated to heterogeneity in species occurrence changes. We provide empirical evidence showing that land-cover change, climate change, and the combination of multiple global change drivers can differentially explain observed species local colonization and extinction. This article is protected

  6. Climate Change: Science, Health and the Environment

    Centers for Disease Control (CDC) Podcasts

    2007-04-10

    Climate Change: Science, Health and the Environment Howard Frumkin, MD, DrPH, Director of CDC's National Center for Environmental Health/Agency for Toxic Substances and Disease Registry, discusses the science of climate change, the potential for shifts in the natural world to affect our wellbeing, and the challenges of emerging issues in environmental health.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  7. [Extinction and Reconsolidation of Memory].

    Science.gov (United States)

    Zuzina, A B; Balaban, P M

    2015-01-01

    retrieval due to adaptation, habituation, changes in environment, etc., then we will observe the extinction; while if these neurons respond to the CS during memory retrieval, we will observe the reconsolidation phenomenon.

  8. Organizational Adaptation: Managing in Complexly Changing Environments.

    Science.gov (United States)

    Zammuto, Raymond F.

    A model of strategic adaptation that focuses on how organizations adapt to both conditions of growth and decline is presented. The theoretical structure underlying the model is considered, with attention to organizations, niches, and environments, as well as environmental change and evolving niches. The model attempts to reconcile the perspectives…

  9. Long-term oceanic changes prior the end-Triassic mass extinction

    Science.gov (United States)

    Clémence, Marie-Emilie; Mette, Wolfgang; Thibault, Nicolas; Korte, Christoph

    2014-05-01

    A number of potential causes and kill mechanisms have been proposed for the end-Triassic mass extinction such as palaeoclimatic and sea-level variations, massive volcanism and ocean acidification. Recent analysis of the stomatal index and density of fossil leaves and geochemical research on pedogenic carbonate nodules are suggestive of rising atmospheric CO2 concentration and fluctuating climate in the Rhaetian. It seems therefore probable that the end-Triassic event was preceded by large climatic fluctuations and environmental perturbations in the Rhaetian which might have partly affected the composition and diversity of the terrestrial and marine biota prior to the end-Triassic interval. The Northern Calcareous Alps (NCA) has long been favored for the study of the Rhaetian, since the GSSP of the Triassic/Jurassic (T/J) boundary and other important T/J sections are situated in this region. However, the most famous Rhaetian sections in the NCA are composed of carbonates from the Koessen Formation and were situated in a large isolated intraplatform Basin (the Eiberg Basin), bordered to the south-east by a well-developed coral reef in the NW of the Tethys border. Several Rhaetian sections composed of marls and shales of the Zlambach Formation were deposited at the same time on the other side of this reef, in the oceanic Halstatt Basin, which was in direct connection to the Tethys. Here, we present new results on sedimentology, stable isotope and trace element analysis of both intraplatform and oceanic basin deposits in the NCA. Intraplatform Rhaetian sections from the Koessen Formation bear a few minor intervals of shales with enrichments in organic matter, some of which are associated to carbon isotopic excursions. Oceanic sections from the Hallstatt Basin are characterized at the base by very cyclic marl-limestone alternations. Higher up in the section, sediments progressively turn into pure shale deposits and the top of the Formation is characterized by organic

  10. The metabotropic glutamate receptor, mGlu5, is required for extinction learning that occurs in the absence of a context change.

    Science.gov (United States)

    André, Marion Agnes Emma; Güntürkün, Onur; Manahan-Vaughan, Denise

    2015-02-01

    The metabotropic glutamate (mGlu) receptors and, in particular, mGlu5 are crucially involved in multiple forms of synaptic plasticity that are believed to underlie explicit memory. MGlu5 is also required for information transfer through neuronal oscillations and for spatial memory. Furthermore, mGlu5 is involved in extinction of implicit forms of learning. This places this receptor in a unique position with regard to information encoding. Here, we explored the role of this receptor in context-dependent extinction learning under constant, or changed, contextual conditions. Animals were trained over 3 days to take a left turn under 25% reward probability in a T-maze with a distinct floor pattern (Context A). On Day 4, they experienced either a floor pattern change (Context B) or the same floor pattern (Context A) in the absence of reward. After acquisition of the task, the animals were returned to the maze once more on Day 5 (Context A, no reward). Treatment with the mGlu5 antagonist, 2-methyl-6-(phenylethynyl) pyridine, before maze exposure on Day 4 completely inhibited extinction learning in the AAA paradigm but had no effect in the ABA paradigm. A subsequent return to the original context (A, on Day 5) revealed successful extinction in the AAA paradigm, but impairment of extinction in the ABA paradigm. These data support that although extinction learning in a new context is unaffected by mGlu5 antagonism, extinction of the consolidated context is impaired. This suggests that mGlu5 is intrinsically involved in enabling learning that once-relevant information is no longer valid. © 2014 The Authors. Hippocampus Published by Wiley Periodicals, Inc.

  11. DEVELOPMENT OF AQUATIC MODELS FOR TESTING THE RELATIONSHIP BETWEEN GENETIC DIVERSITY AND POPULATION EXTINCTION RISK

    Science.gov (United States)

    The relationship between population adaptive potential and extinction risk in a changing environment is not well understood. Although the expectation is that genetic diversity is directly related to the capacity of populations to adapt, the statistical and predictive aspects of ...

  12. Testing Proximate Cause Hypotheses for the End-Ordovician Mass Extinction: Do Patterns of Change in Biomarker Signatures Support a Linkage Between Graptolite and Phytoplankton Community Changes?

    Science.gov (United States)

    Marshall, N.; Thomas, E.; Mitchell, C. E.; Aga, D.; Wombacher, R.

    2017-12-01

    The goal of our study is to analyze the biomarkers in the Vinini Creek section based on a set of samples in which graptolite community change has been identified. The study will test several competing hypotheses about the cause of the observed changes in the environmental proxies and the graptolite community structure and composition. The study interval in the Late Ordovician (444.7-443.4 Ma) was a glacial period with varying climate and sea level changes that are marked by geochemical signatures. Climate change drove changes in deep-ocean circulation and upwelling zones during the concomitant mass extinction and it appears that the graptolites inhabiting the mesopelagic zone were the most vulnerable during these events. Due to the high vulnerability of the graptolites in the Vinini Creek section, biomarkers in the section are especially important for interpreting changing ocean conditions. Changing productivity in the upwelling zones of modern oceans is reflected in the microbial community, which forms the base of the food chain and drives biogeochemical cycles. Moreover, microbes can be traced using organism-specific biomarkers. Steranes (C27-C29) are biomarkers for eukaryotic organisms (e.g., green algae) and hopanes (C27-C35) are biomarkers for bacteria. We will determine hopane-sterane ratios, which reflect measurable relative contributions of bacteria and eukaryotes to sedimentary organic matter as a result of fluctuations in the strength of the oxygen minimum zone and associated denitrification processes. Previous work at lower resolution in this section suggests a decrease in denitrification and increase in abundance of eukaryotes (e.g., green algae) relative to bacteria within the Hirnantian glacial lowstand interval, roughly synchronously with the mass extinction. These relationships suggest that climatically driven changes in nutrient cycling and phytoplankton communities drove the mass extinction. If this is so, then changes in graptolite community

  13. Psychosocial work environment factors and weight change

    DEFF Research Database (Denmark)

    Gram Quist, Helle; Christensen, Ulla; Christensen, Karl Bang

    2013-01-01

    BACKGROUND: Lifestyle variables may serve as important intermediate factors between psychosocial work environment and health outcomes. Previous studies, focussing on work stress models have shown mixed and weak results in relation to weight change. This study aims to investigate psychosocial...... factors outside the classical work stress models as potential predictors of change in body mass index (BMI) in a population of health care workers. METHODS: A cohort study, with three years follow-up, was conducted among Danish health care workers (3982 women and 152 men). Logistic regression analyses...... predicted weight loss among men. Associations were generally weak, with the exception of quality of leadership, age, and cohabitation. CONCLUSION: This study of a single occupational group suggested a few new risk factors for weight change outside the traditional work stress models....

  14. Hypoxia in the changing marine environment

    International Nuclear Information System (INIS)

    Zhang, J; Cowie, G; Naqvi, S W A

    2013-01-01

    The predicted future of the global marine environment, as a combined result of forcing due to climate change (e.g. warming and acidification) and other anthropogenic perturbation (e.g. eutrophication), presents a challenge to the sustainability of ecosystems from tropics to high latitudes. Among the various associated phenomena of ecosystem deterioration, hypoxia can cause serious problems in coastal areas as well as oxygen minimum zones in the open ocean (Diaz and Rosenberg 2008 Science 321 926–9, Stramma et al 2008 Science 320 655–8). The negative impacts of hypoxia include changes in populations of marine organisms, such as large-scale mortality and behavioral responses, as well as variations of species distributions, biodiversity, physiological stress, and other sub-lethal effects (e.g. growth and reproduction). Social and economic activities that are related to services provided by the marine ecosystems, such as tourism and fisheries, can be negatively affected by the aesthetic outcomes as well as perceived or real impacts on seafood quality (STAP 2011 (Washington, DC: Global Environment Facility) p 88). Moreover, low oxygen concentration in marine waters can have considerable feedbacks to other compartments of the Earth system, like the emission of greenhouse gases to the atmosphere, and can affect the global biogeochemical cycles of nutrients and trace elements. It is of critical importance to prediction and adaptation strategies that the key processes of hypoxia in marine environments be precisely determined and understood (cf Zhang et al 2010 Biogeosciences 7 1–24). (synthesis and review)

  15. Hypoxia in the changing marine environment

    Science.gov (United States)

    Zhang, J.; Cowie, G.; Naqvi, S. W. A.

    2013-03-01

    The predicted future of the global marine environment, as a combined result of forcing due to climate change (e.g. warming and acidification) and other anthropogenic perturbation (e.g. eutrophication), presents a challenge to the sustainability of ecosystems from tropics to high latitudes. Among the various associated phenomena of ecosystem deterioration, hypoxia can cause serious problems in coastal areas as well as oxygen minimum zones in the open ocean (Diaz and Rosenberg 2008 Science 321 926-9, Stramma et al 2008 Science 320 655-8). The negative impacts of hypoxia include changes in populations of marine organisms, such as large-scale mortality and behavioral responses, as well as variations of species distributions, biodiversity, physiological stress, and other sub-lethal effects (e.g. growth and reproduction). Social and economic activities that are related to services provided by the marine ecosystems, such as tourism and fisheries, can be negatively affected by the aesthetic outcomes as well as perceived or real impacts on seafood quality (STAP 2011 (Washington, DC: Global Environment Facility) p 88). Moreover, low oxygen concentration in marine waters can have considerable feedbacks to other compartments of the Earth system, like the emission of greenhouse gases to the atmosphere, and can affect the global biogeochemical cycles of nutrients and trace elements. It is of critical importance to prediction and adaptation strategies that the key processes of hypoxia in marine environments be precisely determined and understood (cf Zhang et al 2010 Biogeosciences 7 1-24).

  16. A global cyclostratigraphic framework constrains the timing and pacing of environmental changes over the Late Devonian (Frasnian - Famennian) mass extinction

    Science.gov (United States)

    De Vleeschouwer, David; Da Silva, Anne-Christine; Day, James E.; Whalen, Michael; Claeys, Philippe

    2016-04-01

    Milankovitch cycles (obliquity, eccentricity and precession) result in changes in the distribution of solar energy over seasons, as well as over latitudes, on time scales of ten thousands of years to millions of years. These changing patterns in insolation have induced significant variations in Earth's past climate over the last 4.5 billion years. Cyclostratigraphy and astrochronology utilize the geologic imprint of such quasi-cyclic climatic variations to measure geologic time. In recent years, major improvements of the Geologic Time Scale have been proposed through the application of cyclostratigraphy, mostly for the Mesozoic and Cenozoic (Gradstein et al., 2012). However, the field of Paleozoic cyclostratigraphy and astrochronology is still in its infancy and the application of cyclostratigraphic techniques in the Paleozoic allows for a whole new range of research questions. For example, unraveling the timing and pacing of environmental changes over the Late Devonian mass extinction on a 105-year time-scale concerns such a novel research question. Here, we present a global cyclostratigraphic framework for late Frasnian to early Famennian climatic and environmental change, through the integration of globally distributed sections. The backbone of this relative time scale consists of previously published cyclostratigraphies for western Canada and Poland (De Vleeschouwer et al., 2012; De Vleeschouwer et al., 2013). We elaborate this Euramerican base by integrating new proxy data -interpreted in terms of astronomical climate forcing- from the Iowa basin (USA, magnetic susceptibility and carbon isotope data) and Belgium (XRF and carbon isotope data). Next, we expand this well-established cyclostratigraphic framework towards the Paleo-Tethys Ocean, using magnetic susceptibility and carbon isotope records from the Fuhe section in South China (Whalen et al., 2015). The resulting global cyclostratigraphic framework implies an important refinement of the late Frasnian to

  17. Behavioral tagging of extinction learning.

    Science.gov (United States)

    de Carvalho Myskiw, Jociane; Benetti, Fernando; Izquierdo, Iván

    2013-01-15

    Extinction of contextual fear in rats is enhanced by exposure to a novel environment at 1-2 h before or 1 h after extinction training. This effect is antagonized by administration of protein synthesis inhibitors anisomycin and rapamycin into the hippocampus, but not into the amygdala, immediately after either novelty or extinction training, as well as by the gene expression blocker 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole administered after novelty training, but not after extinction training. Thus, this effect can be attributed to a mechanism similar to synaptic tagging, through which long-term potentiation can be enhanced by other long-term potentiations or by exposure to a novel environment in a protein synthesis-dependent fashion. Extinction learning produces a tag at the appropriate synapses, whereas novelty learning causes the synthesis of plasticity-related proteins that are captured by the tag, strengthening the synapses that generated this tag.

  18. Rescuing Ecosystems from Extinction Cascades

    Science.gov (United States)

    Sahasrabudhe, Sagar; Motter, Adilson

    2010-03-01

    Food web perturbations stemming from climate change, overexploitation, invasive species, and natural disasters often cause an initial loss of species that results in a cascade of secondary extinctions. Using a predictive modeling framework, here we will present a systematic network-based approach to reduce the number of secondary extinctions. We will show that the extinction of one species can often be compensated by the concurrent removal of a second specific species, which is a counter-intuitive effect not previously tested in complex food webs. These compensatory perturbations frequently involve long-range interactions that are not a priori evident from local predator-prey relationships. Strikingly, in numerous cases even the early removal of a species that would eventually be extinct by the cascade is found to significantly reduce the number of cascading extinctions. Other nondestructive interventions based on partial removals and growth suppression and/or mortality increase are shown to sometimes prevent all secondary extinctions.

  19. Geography of current and future global mammal extinction risk.

    Directory of Open Access Journals (Sweden)

    Ana D Davidson

    Full Text Available Identifying which species are at greatest risk, what makes them vulnerable, and where they are distributed are central goals for conservation science. While knowledge of which factors influence extinction risk is increasingly available for some taxonomic groups, a deeper understanding of extinction correlates and the geography of risk remains lacking. Here, we develop a predictive random forest model using both geospatial and mammalian species' trait data to uncover the statistical and geographic distributions of extinction correlates. We also explore how this geography of risk may change under a rapidly warming climate. We found distinctive macroecological relationships between species-level risk and extinction correlates, including the intrinsic biological traits of geographic range size, body size and taxonomy, and extrinsic geographic settings such as seasonality, habitat type, land use and human population density. Each extinction correlate exhibited ranges of values that were especially associated with risk, and the importance of different risk factors was not geographically uniform across the globe. We also found that about 10% of mammals not currently recognized as at-risk have biological traits and occur in environments that predispose them towards extinction. Southeast Asia had the most actually and potentially threatened species, underscoring the urgent need for conservation in this region. Additionally, nearly 40% of currently threatened species were predicted to experience rapid climate change at 0.5 km/year or more. Biological and environmental correlates of mammalian extinction risk exhibit distinct statistical and geographic distributions. These results provide insight into species-level patterns and processes underlying geographic variation in extinction risk. They also offer guidance for future conservation research focused on specific geographic regions, or evaluating the degree to which species-level patterns mirror spatial

  20. Geography of current and future global mammal extinction risk.

    Science.gov (United States)

    Davidson, Ana D; Shoemaker, Kevin T; Weinstein, Ben; Costa, Gabriel C; Brooks, Thomas M; Ceballos, Gerardo; Radeloff, Volker C; Rondinini, Carlo; Graham, Catherine H

    2017-01-01

    Identifying which species are at greatest risk, what makes them vulnerable, and where they are distributed are central goals for conservation science. While knowledge of which factors influence extinction risk is increasingly available for some taxonomic groups, a deeper understanding of extinction correlates and the geography of risk remains lacking. Here, we develop a predictive random forest model using both geospatial and mammalian species' trait data to uncover the statistical and geographic distributions of extinction correlates. We also explore how this geography of risk may change under a rapidly warming climate. We found distinctive macroecological relationships between species-level risk and extinction correlates, including the intrinsic biological traits of geographic range size, body size and taxonomy, and extrinsic geographic settings such as seasonality, habitat type, land use and human population density. Each extinction correlate exhibited ranges of values that were especially associated with risk, and the importance of different risk factors was not geographically uniform across the globe. We also found that about 10% of mammals not currently recognized as at-risk have biological traits and occur in environments that predispose them towards extinction. Southeast Asia had the most actually and potentially threatened species, underscoring the urgent need for conservation in this region. Additionally, nearly 40% of currently threatened species were predicted to experience rapid climate change at 0.5 km/year or more. Biological and environmental correlates of mammalian extinction risk exhibit distinct statistical and geographic distributions. These results provide insight into species-level patterns and processes underlying geographic variation in extinction risk. They also offer guidance for future conservation research focused on specific geographic regions, or evaluating the degree to which species-level patterns mirror spatial variation in the

  1. Climate Change Resilience in the Urban Environment

    Science.gov (United States)

    Kershaw, Tristan

    2017-12-01

    Between 1930 and 2030, the world's population will have flipped from 70% rural to 70% urban. While much has been written about the impacts of climate change and mitigation of its effects on individual buildings or infrastructure, this book is one of the first to focus on the resilience of whole cities. It covers a broad range of area-wide disaster-level impacts, including drought, heatwaves, flooding, storms and air quality, which many of our cities are ill-adapted to cope with, and unless we can increase the resilience of our urban areas then much of our current building stock may become uninhabitable. Climate Resilience in Urban Environments provides a detailed overview of the risks for urban areas, including those risks to human health as well as to building integrity, the physical processes involved, and presents key information in which way the risks can be reduced and urban areas made more resilient.

  2. Are whooping cranes destined for extinction? Climate change imperils recruitment and population growth.

    Science.gov (United States)

    Butler, Matthew J; Metzger, Kristine L; Harris, Grant M

    2017-04-01

    Identifying climatic drivers of an animal population's vital rates and locating where they operate steers conservation efforts to optimize species recovery. The population growth of endangered whooping cranes ( Grus americana ) hinges on juvenile recruitment. Therefore, we identify climatic drivers (solar activity [sunspots] and weather) of whooping crane recruitment throughout the species' life cycle (breeding, migration, wintering). Our method uses a repeated cross-validated absolute shrinkage and selection operator approach to identify drivers of recruitment. We model effects of climate change on those drivers to predict whooping crane population growth given alternative scenarios of climate change and solar activity. Years with fewer sunspots indicated greater recruitment. Increased precipitation during autumn migration signified less recruitment. On the breeding grounds, fewer days below freezing during winter and more precipitation during breeding suggested less recruitment. We predicted whooping crane recruitment and population growth may fall below long-term averages during all solar cycles when atmospheric CO 2 concentration increases, as expected, to 500 ppm by 2050. Species recovery during a typical solar cycle with 500 ppm may require eight times longer than conditions without climate change and the chance of population decline increases to 31%. Although this whooping crane population is growing and may appear secure, long-term threats imposed by climate change and increased solar activity may jeopardize its persistence. Weather on the breeding grounds likely affects recruitment through hydrological processes and predation risk, whereas precipitation during autumn migration may influence juvenile mortality. Mitigating threats or abating climate change should occur within ≈30 years or this wild population of whooping cranes may begin declining.

  3. Non-random extinctions dominate plant community changes in abandoned coppices

    Czech Academy of Sciences Publication Activity Database

    Kopecký, Martin; Hédl, Radim; Szabó, Péter

    2013-01-01

    Roč. 50, č. 1 (2013), s. 79-87 ISSN 0021-8901 R&D Projects: GA AV ČR IAA600050812 Grant - others: ERC - European Union(XE) FP7/2007-2013 ERC no. 278065 Institutional support: RVO:67985939 Keywords : long-term changes * taxonomic homogenization * temporal nestedness Subject RIV: EF - Botanics Impact factor: 4.754, year: 2013

  4. Natural gas -- The changing competitive environment

    International Nuclear Information System (INIS)

    Walker, M.G.

    1993-01-01

    Owners and senior managers don't have to be reminded that the business is getting tougher. Prices aren't behaving as expected, and they are becoming more volatile. Costs are increasing. The futures market is here to stay, not to mention swaps and options. FERC Order 636 is another complicating factor. Whether you are a producer, marketer, pipeline or an LDC, the structure of the market is changing. The answer to the following questions is quite often -- no: Is your company in a position to offer your customers the services they want? Is your company comfortable using hedges? Do you always know your level of risk? Can your company easily track daily positions and P/L and thoughtfully analyze the various business lines? While not all of the above concerns stem from increased price volatility, Order 636 and complexity resulting from the use of more sophisticated risk control instruments, many of them do. There's a cultural change occurring and companies that want to be market leaders must not just ''learn to live'' with this, but install a management process that thrives in this environment. Understanding the meaning of this goal is the focus of this paper

  5. Stress and Fear Extinction

    Science.gov (United States)

    Maren, Stephen; Holmes, Andrew

    2016-01-01

    Stress has a critical role in the development and expression of many psychiatric disorders, and is a defining feature of posttraumatic stress disorder (PTSD). Stress also limits the efficacy of behavioral therapies aimed at limiting pathological fear, such as exposure therapy. Here we examine emerging evidence that stress impairs recovery from trauma by impairing fear extinction, a form of learning thought to underlie the suppression of trauma-related fear memories. We describe the major structural and functional abnormalities in brain regions that are particularly vulnerable to stress, including the amygdala, prefrontal cortex, and hippocampus, which may underlie stress-induced impairments in extinction. We also discuss some of the stress-induced neurochemical and molecular alterations in these brain regions that are associated with extinction deficits, and the potential for targeting these changes to prevent or reverse impaired extinction. A better understanding of the neurobiological basis of stress effects on extinction promises to yield novel approaches to improving therapeutic outcomes for PTSD and other anxiety and trauma-related disorders. PMID:26105142

  6. Providing more informative projections of climate change impact on plant distribution in a mountain environment

    Science.gov (United States)

    Randin, C.; Engler, R.; Pearman, P.; Vittoz, P.; Guisan, A.

    2007-12-01

    Due to their conic shape and the reduction of area with increasing elevation, mountain ecosystems were early identified as potentially very sensitive to global warming. Moreover, mountain systems may experience unprecedented rates of warming during the next century, two or three times higher than that records of the 20th century. In this context, species distribution models (SDM) have become important tools for rapid assessment of the impact of accelerated land use and climate change on the distribution plant species. In this study, we developed and tested new predictor variables for species distribution models (SDM), specific to current and future geographic projections of plant species in a mountain system, using the Western Swiss Alps as model region. Since meso- and micro-topography are relevant to explain geographic patterns of plant species in mountain environments, we assessed the effect of scale on predictor variables and geographic projections of SDM. We also developed a methodological framework of space-for-time evaluation to test the robustness of SDM when projected in a future changing climate. Finally, we used a cellular automaton to run dynamic simulations of plant migration under climate change in a mountain landscape, including realistic distance of seed dispersal. Results of future projections for the 21st century were also discussed in perspective of vegetation changes monitored during the 20th century. Overall, we showed in this study that, based on the most severe A1 climate change scenario and realistic dispersal simulations of plant dispersal, species extinctions in the Western Swiss Alps could affect nearly one third (28.5%) of the 284 species modeled by 2100. With the less severe B1 scenario, only 4.6% of species are predicted to become extinct. However, even with B1, 54% (153 species) may still loose more than 80% of their initial surface. Results of monitoring of past vegetation changes suggested that plant species can react quickly to the

  7. Relating life-history traits, environmental constraints and local extinctions in river fish

    OpenAIRE

    Bergerot, B.; Hugueny, Bernard; Belliard, J.

    2015-01-01

    The life histories of freshwater fish are widely studied because they represent fundamental determinants of population performances. However, a gap remains in our understanding of how species traits may predispose species to extinction in a changing environment. In this study, based on a large data set provided by the French National Agency for Water and Aquatic Environment (325 sites), we analysed factors that explain the probability of local extinction in 40 freshwater species across French...

  8. Interstellar Extinction

    OpenAIRE

    Gontcharov, George

    2017-01-01

    This review describes our current understanding of interstellar extinction. This differ substantially from the ideas of the 20th century. With infrared surveys of hundreds of millions of stars over the entire sky, such as 2MASS, SPITZER-IRAC, and WISE, we have looked at the densest and most rarefied regions of the interstellar medium at distances of a few kpc from the sun. Observations at infrared and microwave wavelengths, where the bulk of the interstellar dust absorbs and radiates, have br...

  9. Climate change risks, extinction debt, and conservation implications for a threatened freshwater fish: Carmine shiner (Notropis percobromus).

    Science.gov (United States)

    Pandit, Shubha N; Maitland, Bryan M; Pandit, Laxmi K; Poesch, Mark S; Enders, Eva C

    2017-11-15

    limitations, suggesting current populations may face an extinction debt within the next half century. These results provide evidence that Carmine shiner may be highly vulnerable to a warming climate and suggest that management actions - such as assisted migration - may be needed to mitigate impacts from climate change and ensure the long-term persistence of the species. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Beta-adrenergic receptors support attention to extinction learning that occurs in the absence, but not the presence, of a context change

    Directory of Open Access Journals (Sweden)

    Marion Emma André

    2015-05-01

    Full Text Available The noradrenergic (NA-system is an important regulator of cognitive function. It contributes to extinction learning(EL, and in disorders where EL is impaired NA-dysfunction has been postulated. We explored whether NA acting on beta-adrenergic-receptors (β-AR, regulates EL that depends on context, but is not fear-associated. We assessed behaviour in an ‘AAA’ or ‘ABA’ paradigm: rats were trained for 3 days in a T-maze(context-A to learn that a reward is consistently found in the goal arm, despite low reward probability. This was followed on day 4 by EL(unrewarded, whereby in the ABA-paradigm, EL was reinforced by a context change (B, and in the AAA-paradigm, no context change occurred. On day 5, re-exposure to the A-context (unrewarded occurred. Typically, in control ‘AAA’ animals EL occurred on day 4 that progressed further on day 5. In control ‘ABA’ animals, EL also occurred on day 4, followed by renewal of the previously learned (A behavior on day 5, that was followed (in day 5 by extinction of this behavior, as the animals realised that no food reward would be given.Treatment with the β-AR-antagonist, propranolol, prior to EL on day 4, impaired EL in the AAA-paradigm. In the ‘ABA’ paradigm, antagonist treatment on day 4, had no effect on extinction that was reinforced by a context change (B. Furthermore, β-AR-antagonism prior to renewal testing (on day 5 in the ABA-paradigm, resulted in normal renewal behavior, although subsequent extinction of responses during day 5 was prevented by the antagonist. Thus, under both treatment conditions, β-AR-antagonism prevented extinction of the behavior learned in the ‘A’ context.β-AR-blockade during an overt context change did not prevent EL, whereas β-AR were required for EL in an unchanging context. These data suggest that β-AR may support EL by reinforcing attention towards relevant changes in the previously learned experience, and that this process supports extinction

  11. Beta-adrenergic receptors support attention to extinction learning that occurs in the absence, but not the presence, of a context change

    Science.gov (United States)

    André, Marion Agnès Emma; Wolf, Oliver T.; Manahan-Vaughan, Denise

    2015-01-01

    The noradrenergic (NA)-system is an important regulator of cognitive function. It contributes to extinction learning (EL), and in disorders where EL is impaired NA-dysfunction has been postulated. We explored whether NA acting on beta-adrenergic-receptors (β-AR), regulates EL that depends on context, but is not fear-associated. We assessed behavior in an “AAA” or “ABA” paradigm: rats were trained for 3 days in a T-maze (context-A) to learn that a reward is consistently found in the goal arm, despite low reward probability. This was followed on day 4 by EL (unrewarded), whereby in the ABA-paradigm, EL was reinforced by a context change (B), and in the AAA-paradigm, no context change occurred. On day 5, re-exposure to the A-context (unrewarded) occurred. Typically, in control “AAA” animals EL occurred on day 4 that progressed further on day 5. In control “ABA” animals, EL also occurred on day 4, followed by renewal of the previously learned (A) behavior on day 5, that was succeeded (on day 5) by extinction of this behavior, as the animals realised that no food reward would be given. Treatment with the β-AR-antagonist, propranolol, prior to EL on day 4, impaired EL in the AAA-paradigm. In the “ABA” paradigm, antagonist treatment on day 4, had no effect on extinction that was reinforced by a context change (B). Furthermore, β-AR-antagonism prior to renewal testing (on day 5) in the ABA-paradigm, resulted in normal renewal behavior, although subsequent extinction of responses during day 5 was prevented by the antagonist. Thus, under both treatment conditions, β-AR-antagonism prevented extinction of the behavior learned in the “A” context. β-AR-blockade during an overt context change did not prevent EL, whereas β-AR were required for EL in an unchanging context. These data suggest that β-AR may support EL by reinforcing attention towards relevant changes in the previously learned experience, and that this process supports extinction

  12. Contrasting effects of climate change in continental vs. oceanic environments on population persistence and microevolution of Atlantic salmon.

    Science.gov (United States)

    Piou, Cyril; Prévost, Etienne

    2013-03-01

    Facing climate change (CC), species are prone to multiple modifications in their environment that can lead to extinction, migration or adaptation. Identifying the role and interplay of different potential stressors becomes a key question. Anadromous fishes will be exposed to both river and oceanic habitat changes. For Atlantic salmon, the river water temperature, river flow and oceanic growth conditions appear as three main stressing factors. They could act on population dynamics or as selective forces on life-history pathways. Using an individual-based demo-genetic model, we assessed the effects of these factors (1) to compare risks of extinction resulting from CC in river and ocean, and (2) to assess CC effects on life-history pathways including the evolution of underlying genetic control of phenotypic plasticity. We focused on Atlantic salmon populations from Southern Europe for a time horizon of three decades. We showed that CC in river alone should not lead to extinction of Southern European salmon populations. In contrast, the reduced oceanic growth appeared as a significant threat for population persistence. An increase in river flow amplitude increased the risk of local extinction in synergy with the oceanic effects, but river temperature rise reduced this risk. In terms of life-history modifications, the reduced oceanic growth increased the age of return of individuals through plastic and genetic responses. The river temperature rise increased the proportion of sexually mature parr, but the genetic evolution of the maturation threshold lowered the maturation rate of male parr. This was identified as a case of environmentally driven plastic response that masked an underlying evolutionary response of plasticity going in the opposite direction. We concluded that to counteract oceanic effects, river flow management represented the sole potential force to reduce the extinction probability of Atlantic salmon populations in Southern Europe, although this might

  13. Changing palaeoenvironments and tetrapod populations in the Daptocephalus Assemblage Zone (Karoo Basin, South Africa) indicate early onset of the Permo-Triassic mass extinction

    Science.gov (United States)

    Viglietti, Pia A.; Smith, Roger M. H.; Rubidge, Bruce S.

    2018-02-01

    Important palaeoenvironmental differences are identified during deposition of the latest Permian Daptocephalus Assemblage Zone (DaAZ) of the South African Beaufort Group (Karoo Supergoup), which is also divided into a Lower and Upper subzone. A lacustrine floodplain facies association showing evidence for higher water tables and subaqueous conditions on the floodplains is present in Lower DaAZ. The change to well-drained floodplain facies association in the Upper DaAZ is coincident with a faunal turnover as evidenced by the last appearance of the dicynodont Dicynodon lacerticeps, the therocephalian Theriognathus microps, the cynodont Procynosuchus delaharpeae, and first appearance of the dicynodont Lystrosaurus maccaigi within the Ripplemead member. Considering the well documented 3-phased extinction of Karoo tetrapods during the Permo-Triassic Mass Extinction (PTME), the facies transition between the Lower and Upper DaAZ represents earlier than previously documented palaeoenvironmental changes associated with the onset of this major global biotic crisis.

  14. Dousing our inflammatory environment(s): is personal carbon trading an option for reducing obesity--and climate change?

    Science.gov (United States)

    Egger, G

    2008-09-01

    Obesity and climate change are two problems currently challenging humanity. Although apparently unrelated, an epidemiological approach to both shows a similar environmental aetiology, based in modern human lifestyles and their driving economic forces. One way of analysing this is through inflammation (defined as '. . . a disturbance of function following insult or injury') of both the internal (biological) and external (ecological) environments. Chronic, low-grade, systemic inflammation has recently been shown to accompany obesity, as well as a range of biological pathologies associated with obesity (diabetes, heart disease, some cancers, etc.). This is influenced by the body's inability to soak up excess glucose as a result of insulin resistance. In a broader sense, inflammation is a metaphor for ecological 'pathologies', manifest particularly in unnatural disturbances like climate change, ocean acidity, rising temperatures and species extinction, associated with the inability of the world's environmental 'sinks' to soak up carbon dioxide ('carbon resistance'?). The use of such a metaphorical analysis opens the possibilities for dealing with two interdisciplinary problems simultaneously. Strategies for managing climate change, including personal carbon trading, could provide a 'stealth intervention' for reducing population levels of obesity by increasing personal energy expenditure and decreasing energy-dense food intake, as well as reducing the carbon emissions causing climate change.

  15. Long-Term Synaptic Changes in Two Input Pathways into the Lateral Nucleus of the Amygdala Underlie Fear Extinction

    Science.gov (United States)

    Park, Junchol; Choi, June-Seek

    2010-01-01

    Plasticity in two input pathways into the lateral nucleus of the amygdala (LA), the medial prefrontal cortex (mPFC) and the sensory thalamus, have been suggested to underlie extinction, suppression of a previously acquired conditioned response (CR) following repeated presentations of the conditioned stimulus (CS). However, little is known about…

  16. Biological hierarchies and the nature of extinction.

    Science.gov (United States)

    Congreve, Curtis R; Falk, Amanda R; Lamsdell, James C

    2018-05-01

    Hierarchy theory recognises that ecological and evolutionary units occur in a nested and interconnected hierarchical system, with cascading effects occurring between hierarchical levels. Different biological disciplines have routinely come into conflict over the primacy of different forcing mechanisms behind evolutionary and ecological change. These disconnects arise partly from differences in perspective (with some researchers favouring ecological forcing mechanisms while others favour developmental/historical mechanisms), as well as differences in the temporal framework in which workers operate. In particular, long-term palaeontological data often show that large-scale (macro) patterns of evolution are predominantly dictated by shifts in the abiotic environment, while short-term (micro) modern biological studies stress the importance of biotic interactions. We propose that thinking about ecological and evolutionary interactions in a hierarchical framework is a fruitful way to resolve these conflicts. Hierarchy theory suggests that changes occurring at lower hierarchical levels can have unexpected, complex effects at higher scales due to emergent interactions between simple systems. In this way, patterns occurring on short- and long-term time scales are equally valid, as changes that are driven from lower levels will manifest in different forms at higher levels. We propose that the dual hierarchy framework fits well with our current understanding of evolutionary and ecological theory. Furthermore, we describe how this framework can be used to understand major extinction events better. Multi-generational attritional loss of reproductive fitness (MALF) has recently been proposed as the primary mechanism behind extinction events, whereby extinction is explainable solely through processes that result in extirpation of populations through a shutdown of reproduction. While not necessarily explicit, the push to explain extinction through solely population-level dynamics

  17. Structural changes of noble metal catalysts during ignition and extinction of the partial oxidation of methane studied by advanced QEXAFS techniques

    DEFF Research Database (Denmark)

    Grunwaldt, Jan-Dierk; Beier, M.; Kimmerle, B.

    2009-01-01

    The dynamics of the ignition and extinction of the catalytic partial oxidation (CPO) of methane to hydrogen and carbon monoxide over Pt-Rh/Al2O3 and Pt/Al2O3 were studied in the subsecond timescale using quick-EXAFS with a novel cam-driven X-ray monochromator employing Si(111) and Si(311) crystals...... to discuss the potential and limitation of this technique in catalysis and related areas. With respect to the noble metal catalysed partial oxidation of methane, several interesting observations were made: structural changes during ignition were-independent of the chosen reaction conditions......-significantly faster than during the extinction of the reaction. The dynamic behavior of the catalysts was dependent on the flow conditions and the respective noble metal component(s). Higher reaction gas flow led to a faster ignition process. While the ignition over Pt-Rh/Al2O3 occurred at lower temperature than over...

  18. Climate Change, Indoor Environment and Health

    Science.gov (United States)

    Climate change is becoming a driving force for improving energy efficiency because saving energy can help reduce the greenhouse gas emissions that contribute to climate change. However, it is important to balance energy saving measures with ventilation...

  19. Adapting to a Changing Environment: Modeling the Interaction of Directional Selection and Plasticity.

    Science.gov (United States)

    Nunney, Leonard

    2016-01-01

    Human-induced habitat loss and fragmentation constrains the range of many species, making them unable to respond to climate change by moving. For such species to avoid extinction, they must respond with some combination of phenotypic plasticity and genetic adaptation. Haldane's "cost of natural selection" limits the rate of adaptation, but, although modeling has shown that in very large populations long-term adaptation can be maintained at rates substantially faster than Haldane's suggested limit, maintaining large populations is often an impossibility, so phenotypic plasticity may be crucial in enhancing the long-term survival of small populations. The potential importance of plasticity is in "buying time" for populations subject to directional environmental change: if genotypes can encompass a greater environmental range, then populations can maintain high fitness for a longer period of time. Alternatively, plasticity could be detrimental by lessening the effectiveness of natural selection in promoting genetic adaptation. Here, I modeled a directionally changing environment in which a genotype's adaptive phenotypic plasticity is centered around the environment where its fitness is highest. Plasticity broadens environmental tolerance and, provided it is not too costly, is favored by natural selection. However, a paradoxical result of the individually advantageous spread of plasticity is that, unless the adaptive trait is determined by very few loci, the long-term extinction risk of a population increases. This effect reflects a conflict between the short-term individual benefit of plasticity and a long-term detriment to population persistence, adding to the multiple threats facing small populations under conditions of climate change. © The American Genetic Association. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Preface. Forest ecohydrological processes in a changing environment.

    Science.gov (United States)

    Xiaohua Wei; Ge Sun; James Vose; Kyoichi Otsuki; Zhiqiang Zhang; Keith Smetterm

    2011-01-01

    The papers in this issue are a selection of the presentations made at the second International Conference on Forests and Water in a Changing Environment. This special issue ‘Forest Ecohydrological Processes in a Changing Environment’ covers the topics regarding the effects of forest, land use and climate changes on ecohydrological processes across forest stand,...

  1. Legal Research in a Changing Information Environment

    African Journals Online (AJOL)

    tduplessis

    opportunities for research into constitutional issues, constitutional development and the relationship ... Legal research is a fundamental skill in the legal profession.9 Although all areas of law do not require ..... 1999 Legal RSQ 78. 56 In the print information environment lawyers use standard citation formats, e.g. X v Z 1999.

  2. Resilience of livestock to changing environments

    Science.gov (United States)

    The Breeding and Genetics Symposium titled “Resilience of Livestock to Changing Environments” was held at the Joint Annual Meeting, July 19–24, 2016, Salt Lake City, UT. The objective of the symposium was to provide a broad overview of recent research on the effects of changing environmental conditi...

  3. Demographics and the Changing National Security Environment

    National Research Council Canada - National Science Library

    2000-01-01

    .... Long- term fertility trends, urbanization, migration, and changes in the ethnic composition and age profile of populations can influence the likelihood and nature of conflict among and within nations...

  4. Development, energy, environment: changing the paradigm

    International Nuclear Information System (INIS)

    2006-01-01

    A first set of contributions comments the various risks and challenges which are to be faced in terms of energy, climate and environment: the deadlock of present 'laisser-faire' policies, recent findings in climate science in 2005, oil as the reason of a possible economic crisis in developing countries, recent evolution of energy systems. The next set of contributions discusses the possible solutions and their limits: CO 2 capture and sequestration in coal plants, nuclear renaissance, renewable energies, hydro-electricity, CO 2 capture by biomass, energy sobriety, urban morphology and transports in emerging cities, integration of service demand with energy supply, energy decentralized production

  5. Layer breeding programmes in changing production environments

    NARCIS (Netherlands)

    LEENSTRA, F.; TEN NAPEL, J.; VISSCHER, J.; VAN SAMBEEK, F.

    2016-01-01

    The housing and management of laying hens and their productivity has gone through enormous developments in the last century. Housing has changed from free-range systems, via battery cages to a variety of loose housing and different types of battery cages, and back to outdoor access systems.

  6. Trophic strategy of Atlantirivulus riograndensis (Cyprinodontiformes: Rivulidae, a non-annual rivulid threatened by extinction, in a perennial environment, Brazil

    Directory of Open Access Journals (Sweden)

    Laísa Wociechoski Cavalheiro

    Full Text Available ABSTRACT Rivulidae includes non-annual fish of perennial habitats and annual fish of temporary wetlands. The objective of this research was to investigate the trophic strategy of Atlantirivulus riograndensis in a perennial environment. Sampling occurred in an environmental conservation unit in the Pampa biome, Brazil. Quantification of the diet followed the volumetric method. Consumption of autochthonous material as the main food source of the species followed the pattern of Rivulidae. Species is zooplanktonic when young. Food spectrum is broadened and insectivorousness increases with ontogeny, revealing a specialist trend in the feeding strategy of A. riograndensis. The most diverse feeding occurs in the spring and summer seasons in which the presence of larger fish was more frequent than in other seasons. The increased consumption of microcrustaceans in the fall was related to smaller individuals, captured in greater quantities in this post-reproductive period. The lowest diversity of dietary items occurs during the winter and may reflect the lower diversity of food resources available in this season or the transition from juvenile to adult diet, with consumption of autochthonous Diptera by medium sized fish.

  7. Department Chairs as Change Agents: Leading Change in Resistant Environments

    Science.gov (United States)

    Gaubatz, Julie A.; Ensminger, David C.

    2017-01-01

    Change process research often discusses barriers that impede organizational change (e.g., Banta, 1997; Cavacuiti and Locke, 2013; Mutchler, 1990; Stewart et al., 2012); however, no empirical research has addressed how behaviors established in leadership models counteract these barriers. This study explored these two interconnected constructs of…

  8. The changing winds of atmospheric environment policy

    International Nuclear Information System (INIS)

    Murray, Frank

    2013-01-01

    Highlights: ► Changes in atmosphere policies over several decades are analysed. ► Direct regulation is less effective and been complemented by other instruments. ► Policy approaches are more complex and integrated and the scale of the issues has evolved. ► The role of stakeholders has grown and the corporate sector has assumed increased responsibility. ► Governance arrangements have become more complex, multilevel and polycentric. -- Abstract: Atmospheric environmental policies have changed considerably over the last several decades. Clearly the relative importance of the various issues has changed over half a century, for example from smoke, sulphur dioxide and photochemical smog being the top priorities to greenhouse gases being the major priority. The traditional policy instrument to control emissions to the atmosphere has been command and control regulation. In many countries this was successful in reducing emissions from point sources, the first generation issues, and to a lesser extent, emissions from mobile and area sources, the second generation issues, although challenges remain in many jurisdictions. However once the simpler, easier, cheaper and obvious targets had been at least partially controlled this form of regulation became less effective. It has been complemented by other instruments including economic instruments, self-regulation, voluntarism and information instruments to address more complex issues including climate change, a third generation issue. Policy approaches to atmospheric environmental issues have become more complex. Policies that directly focus on atmospheric issues have been partially replaced by more integrated approaches that consider multimedia (water, land, etc.) and sustainability issues. Pressures from stakeholders for inclusion, greater transparency and better communication have grown and non-government stakeholders have become increasingly important participants in governance. The scale of the issues has evolved

  9. Seasonal atmospheric extinction

    International Nuclear Information System (INIS)

    Mikhail, J.S.

    1979-01-01

    Mean monochromatic extinction coefficients at various wavelengths at the Kottamia Observatory site have shown the existence of a seasonal variation of atmospheric extinction. The extinction of aerosol compontnts with wavelengths at winter represent exceedingly good conditions. Spring gives the highest extinction due to aerosol. (orig.)

  10. Changing the food environment: the French experience.

    Science.gov (United States)

    Chauliac, Michel; Hercberg, Serge

    2012-07-01

    The French National Nutrition and Health Program was launched in 2001. To achieve its objectives, 2 main preventive strategies were identified: 1) provide information and education to help individuals make healthy food and physical activity choices; and 2) improve the food and physical environment so that making healthy choices is easier. School regulations have been established to improve the nutritional quality of meals served to children and adolescents, and vending machines have been banned. Since 2007, companies in France's food industry have had the option of signing the national government's "Charte d'engagement volontaire de progrès nutritionnel" (charter of commitments to nutritional improvements) which aims to benefit all consumers. A standard reference document, developed by public authorities as the basis for decisions made by a committee of experts in the food industry, aims to validate the voluntary commitments made by companies to improve the nutrient content of the foods they produce. There is strict follow-up. A Food Quality Observatory was created in 2009 to monitor the nutrient quality of the food supply in France. Various results show the positive impact of these actions.

  11. Fostering Entrepreneurship in a Changing Business Environment

    Directory of Open Access Journals (Sweden)

    Laurentiu Tachiciu

    2015-02-01

    Full Text Available Entrepreneurship is the cornerstone of a modern competitive economy. Because of the economic and social importance attributed to entrepreneurship, every country has adopted policies aiming to encourage and to support entrepreneurial attitudes and behaviors. Despite the fact that the set of public policy measures is very similar across countries and regions, the outcomes are different. The differences can be observed not only in quantitative terms (i.e. number of newly established ventures, but also in qualitative terms (i.e. proportion of innovative firms, intensity of knowledge and technological level, degree of internationalization etc.. Indeed, entrepreneurship takes different forms ranging from an alternative to employment (self-employed to creation of innovative, competitive and fast growing enterprises. It is also recognized the corporate entrepreneurship, the social entrepreneurship and even the entrepreneurship in the public sector. Different forms of entrepreneurship have a different impact in terms of general progress. Scholars have shown that context is an important factor explaining the variability of entrepreneurship outcomes, calling for a better understanding of the business environment influence on the intensity and quality of the entrepreneurial activity.

  12. Extinction risk escalates in the tropics.

    Directory of Open Access Journals (Sweden)

    Jana C Vamosi

    Full Text Available The latitudinal biodiversity gradient remains one of the most widely recognized yet puzzling patterns in nature. Presently, the high level of extinction of tropical species, referred to as the "tropical biodiversity crisis", has the potential to erode this pattern. While the connection between species richness, extinction, and speciation has long intrigued biologists, these interactions have experienced increased poignancy due to their relevancy to where we should concentrate our conservation efforts. Natural extinction is a phenomenon thought to have its own latitudinal gradient, with lower extinction rates in the tropics being reported in beetles, birds, mammals, and bivalves. Processes that have buffered ecosystems from high extinction rates in the past may also buffer ecosystems against disturbance of anthropogenic origin. While potential parallels between historical and present-day extinction patterns have been acknowledged, they remain only superficially explored and plant extinction patterns have been particularly neglected. Studies on the disappearances of animal species have reached conflicting conclusions, with the rate of extinction appearing either higher or lower in species richness hotspots. Our global study of extinction risk in vascular plants finds disproportionately higher extinction risk in tropical countries, even when indicators of human pressure (GDP, population density, forest cover change are taken into account. Our results are at odds with the notion that the tropics represent a museum of plant biodiversity (places of historically lowered extinction and we discuss mechanisms that may reconcile this apparent contradiction.

  13. Extinction risk escalates in the tropics.

    Science.gov (United States)

    Vamosi, Jana C; Vamosi, Steven M

    2008-01-01

    The latitudinal biodiversity gradient remains one of the most widely recognized yet puzzling patterns in nature. Presently, the high level of extinction of tropical species, referred to as the "tropical biodiversity crisis", has the potential to erode this pattern. While the connection between species richness, extinction, and speciation has long intrigued biologists, these interactions have experienced increased poignancy due to their relevancy to where we should concentrate our conservation efforts. Natural extinction is a phenomenon thought to have its own latitudinal gradient, with lower extinction rates in the tropics being reported in beetles, birds, mammals, and bivalves. Processes that have buffered ecosystems from high extinction rates in the past may also buffer ecosystems against disturbance of anthropogenic origin. While potential parallels between historical and present-day extinction patterns have been acknowledged, they remain only superficially explored and plant extinction patterns have been particularly neglected. Studies on the disappearances of animal species have reached conflicting conclusions, with the rate of extinction appearing either higher or lower in species richness hotspots. Our global study of extinction risk in vascular plants finds disproportionately higher extinction risk in tropical countries, even when indicators of human pressure (GDP, population density, forest cover change) are taken into account. Our results are at odds with the notion that the tropics represent a museum of plant biodiversity (places of historically lowered extinction) and we discuss mechanisms that may reconcile this apparent contradiction.

  14. Rescaling of temporal expectations during extinction

    Science.gov (United States)

    Drew, Michael R.; Walsh, Carolyn; Balsam, Peter D

    2016-01-01

    Previous research suggests that extinction learning is temporally specific. Changing the CS duration between training and extinction can facilitate the loss of the CR within the extinction session but impairs long-term retention of extinction. In two experiments using conditioned magazine approach with rats, we examined the relation between temporal specificity of extinction and CR timing. In Experiment 1 rats were trained on a 12-s, fixed CS-US interval and then extinguished with CS presentations that were 6, 12, or 24 s in duration. The design of Experiment 2 was the same except rats were trained using partial rather than continuous reinforcement. In both experiments, extending the CS duration in extinction facilitated the diminution of CRs during the extinction session, but shortening the CS duration failed to slow extinction. In addition, extending (but not shortening) the CS duration caused temporal rescaling of the CR, in that the peak CR rate migrated later into the trial over the course of extinction training. This migration partially accounted for the faster loss of the CR when the CS duration was extended. Results are incompatible with the hypothesis that extinction is driven by cumulative CS exposure and suggest that temporally extended nonreinforced CS exposure reduces conditioned responding via temporal displacement rather than through extinction per se. PMID:28045291

  15. The environment and directed technical change: comment

    International Nuclear Information System (INIS)

    Hourcade, Jean-Charles; Pottier, Antonin; Espagne, Etienne

    2011-11-01

    This paper discusses the growth model with environmental constraints recently presented in (Acemoglu et al., 2011) which focuses on the redirection of technical change by climate policies with research subsidies and a carbon tax. First, Acemoglu et al.'s model and chosen parameters yield numerical results that do not support the conclusion that ambitious climate policies can be conducted 'without sacrificing (much or any) long-run growth'. Second, they select unrealistic key parameters for carbon sinks and elasticity of substitution. We find that more realistic parameters lead to very different results. Third, the model leads to an unrealistic conclusion when used to analyse endogenous growth, suggesting specification problems. (authors)

  16. Response of Sphagna to the changing environment

    Energy Technology Data Exchange (ETDEWEB)

    Vasander, H. [Helsinki Univ. (Finland). Dept. of Forest Ecology; Jauhiainen, J.; Silvola, J. [Joensuu Univ. (Finland). Dept. of Biology; Karsisto, M. [Finnish Forest Research Inst., Vantaa (Finland)

    1996-12-31

    During last decade, considerable interest has been focused to assess the influence of human activities on ecosystems. The increasing trend in the atmospheric concentration of CO{sub 2} has been predicted to continue till the next century and the amount of nitrogen deposition in the northern hemisphere has increased markedly. Substantial interest has been focused on predicting how these changes will affect on plants. Most boreal mire ecosystems are dominated by mosses of the genus Sphagnum, the litter of which constitutes the main component in the peat deposits and is an important CO{sub 2} sink via peat formation. Since virtually nothing was known about the growth response of peat mosses to elevated concentrations of CO{sub 2} and alerting changes in species composition were detected in the sensitive ombrotrophic mire vegetation under increased N deposition in central Europe, this study was established. Laboratory experiments focused on measurements of the patterns of growth, production and plant metabolism at increased CO{sub 2} and N deposition levels in peat moss species. Long term field experiments were established to study the growth response and spatial competition of two interacting Sphagnum species under the increased nitrogen deposition levels

  17. Response of Sphagna to the changing environment

    Energy Technology Data Exchange (ETDEWEB)

    Vasander, H [Helsinki Univ. (Finland). Dept. of Forest Ecology; Jauhiainen, J; Silvola, J [Joensuu Univ. (Finland). Dept. of Biology; Karsisto, M [Finnish Forest Research Inst., Vantaa (Finland)

    1997-12-31

    During last decade, considerable interest has been focused to assess the influence of human activities on ecosystems. The increasing trend in the atmospheric concentration of CO{sub 2} has been predicted to continue till the next century and the amount of nitrogen deposition in the northern hemisphere has increased markedly. Substantial interest has been focused on predicting how these changes will affect on plants. Most boreal mire ecosystems are dominated by mosses of the genus Sphagnum, the litter of which constitutes the main component in the peat deposits and is an important CO{sub 2} sink via peat formation. Since virtually nothing was known about the growth response of peat mosses to elevated concentrations of CO{sub 2} and alerting changes in species composition were detected in the sensitive ombrotrophic mire vegetation under increased N deposition in central Europe, this study was established. Laboratory experiments focused on measurements of the patterns of growth, production and plant metabolism at increased CO{sub 2} and N deposition levels in peat moss species. Long term field experiments were established to study the growth response and spatial competition of two interacting Sphagnum species under the increased nitrogen deposition levels

  18. Essays in energy, environment and technological change

    Science.gov (United States)

    Zhou, Yichen Christy

    This dissertation studies technological change in the context of energy and environmental economics. Technology plays a key role in reducing greenhouse gas emissions from the transportation sector. Chapter 1 estimates a structural model of the car industry that allows for endogenous product characteristics to investigate how gasoline taxes, R&D subsidies and competition affect fuel efficiency and vehicle prices in the medium-run, both through car-makers' decisions to adopt technologies and through their investments in knowledge capital. I use technology adoption and automotive patents data for 1986-2006 to estimate this model. I show that 92% of fuel efficiency improvements between 1986 and 2006 were driven by technology adoption, while the role of knowledge capital is largely to reduce the marginal production costs of fuel-efficient cars. A counterfactual predicts that an additional 1/gallon gasoline tax in 2006 would have increased the technology adoption rate, and raised average fuel efficiency by 0.47 miles/gallon, twice the annual fuel efficiency improvement in 2003-2006. An R&D subsidy that would reduce the marginal cost of knowledge capital by 25% in 2006 would have raised investment in knowledge capital. This subsidy would have raised fuel efficiency only by 0.06 miles/gallon in 2006, but would have increased variable profits by 2.3 billion over all firms that year. Passenger vehicle fuel economy standards in the United States will require substantial improvements in new vehicle fuel economy over the next decade. Economic theory suggests that vehicle manufacturers adopt greater fuel-saving technologies for vehicles with larger market size. Chapter 2 documents a strong connection between market size, measured by sales, and technology adoption. Using variation consumer demographics and purchasing pattern to account for the endogeneity of market size, we find that a 10 percent increase in market size raises vehicle fuel efficiency by 0.3 percent, as compared

  19. Asian Urban Environment and Climate Change: Preface.

    Science.gov (United States)

    Hunt, Julian; Wu, Jianping

    2017-09-01

    The Asian Network on Climate Science and Technology (www.ancst.org), in collaboration with Tsinghua University, held a conference on environmental and climate science, air pollution, urban planning and transportation in July 2015, with over 40 Asian experts participating and presentation. This was followed by a meeting with local government and community experts on the practical conclusions of the conference. Of the papers presented at the conference a selection are included in this special issue of Journal of Environmental Science, which also reflects the conclusions of the Paris Climate meeting in Dec 2015, when the major nations of the world agreed about the compelling need to reduce the upward trend of adverse impacts associated with global climate change. Now is the time for urban areas to work out the serious consequences for their populations, but also how they should work together to take action to reduce global warming to benefit their own communities and also the whole planet! Copyright © 2017. Published by Elsevier B.V.

  20. CHANGE MANAGEMENT STRATEGIES RELATED TO THE GLOBAL ENVIRONMENT COMPLEXITY

    Directory of Open Access Journals (Sweden)

    Elena DOVAL

    2016-12-01

    Full Text Available The changes in organizations appear as a reaction to the organizational environment changes. In order to manage these changes successfully, the managers need to anticipate and design alternative strategies by preparing different options.  Nevertheless, the complexity of the global environment forces the managers to adopt strategies for their organizations that are facilitating the creation of new strategic competences and competitive advantages to face the environmental rapid changes. In this context, this paper is aiming to illustrate the main directions the change management may consider to change the organization strategies in order to harmonize them to the external environment, such as: integration versus externalization, flexible specialization and flexible organization, standardization versus adaptation, market segmentation, relationship building and maintaining and communication integration.  However, the new strategies are based on a changed attitude of the managers towards the competitive advantage that is dynamic and focused on creation rather then to operations.

  1. Facilitation among plants in alpine environments in the face of climate change

    Directory of Open Access Journals (Sweden)

    Fabien eAnthelme

    2014-08-01

    Full Text Available While there is a large consensus that plant–plant interactions are a crucial component of the response of plant communities to the effects of climate change, available data remain scarce, particularly in alpine systems. This represents an important obstacle to making consistent predictions about the future of plant communities. Here, we review current knowledge on the effects of climate change on facilitation among alpine plant communities and propose directions for future research. In established alpine communities, while warming seemingly generates a net facilitation release, earlier snowmelt may increase facilitation. Some nurse plants are able to buffer microenvironmental changes in the long term and may ensure the persistence of other alpine plants through local migration events. For communities migrating to higher elevations, facilitation should play an important role in their reorganization because of the harsher environmental conditions. In particular, the absence of efficient nurse plants might slow down upward migration, possibly generating chains of extinction. Facilitation–climate change relationships are expected to shift along latitudinal gradients because (1 the magnitude of warming is predicted to vary along these gradients, and (2 alpine environments are significantly different at low vs. high latitudes. Data on these expected patterns are preliminary and thus need to be tested with further studies on facilitation among plants in alpine environments that have thus far not been considered. From a methodological standpoint, future studies will benefit from the spatial representation of the microclimatic environment of plants to predict their response to climate change. Moreover, the acquisition of long-term data on the dynamics of plant–plant interactions, either through permanent plots or chronosequences of glacial recession, may represent powerful approaches to clarify the relationship between plant interactions and

  2. Facilitation among plants in alpine environments in the face of climate change.

    Science.gov (United States)

    Anthelme, Fabien; Cavieres, Lohengrin A; Dangles, Olivier

    2014-01-01

    While there is a large consensus that plant-plant interactions are a crucial component of the response of plant communities to the effects of climate change, available data remain scarce, particularly in alpine systems. This represents an important obstacle to making consistent predictions about the future of plant communities. Here, we review current knowledge on the effects of climate change on facilitation among alpine plant communities and propose directions for future research. In established alpine communities, while warming seemingly generates a net facilitation release, earlier snowmelt may increase facilitation. Some nurse plants are able to buffer microenvironmental changes in the long term and may ensure the persistence of other alpine plants through local migration events. For communities migrating to higher elevations, facilitation should play an important role in their reorganization because of the harsher environmental conditions. In particular, the absence of efficient nurse plants might slow down upward migration, possibly generating chains of extinction. Facilitation-climate change relationships are expected to shift along latitudinal gradients because (1) the magnitude of warming is predicted to vary along these gradients, and (2) alpine environments are significantly different at low vs. high latitudes. Data on these expected patterns are preliminary and thus need to be tested with further studies on facilitation among plants in alpine environments that have thus far not been considered. From a methodological standpoint, future studies will benefit from the spatial representation of the microclimatic environment of plants to predict their response to climate change. Moreover, the acquisition of long-term data on the dynamics of plant-plant interactions, either through permanent plots or chronosequences of glacial recession, may represent powerful approaches to clarify the relationship between plant interactions and climate change.

  3. Climate change adaptation of the built environment – an examination

    DEFF Research Database (Denmark)

    Majgaard Krarup, Jonna

    2014-01-01

    phenomena. This is why the term 'environmental changes' might be more accurate than climate change. ‘Environmental changes’ suggests that climate changes ought to be understood as extensive environmental changes, with an impact on the built environment. Following this, it is no longer sufficient only...... to assess for example a building, and anthropogenic impacts on the environment, also the impact of the environment on installations, and on the human activities must be included in the analysis and assessments. Based on observations and investigations into climate change adaptation in DK and abroad......In a Danish context, climate changes are primarily manifested in an interaction between modified wind and precipitation patterns, increasing temperature and a rising sea level. The individual factors often act together and are reinforced in interaction with already known natural and cultural...

  4. Interstellar extinction and polarization in the infrared

    International Nuclear Information System (INIS)

    Martin, P.G.; Whittet, D.C.B.

    1990-01-01

    The wavelength dependences of interstellar continuum extinction and polarization in the range 0.35-5 microns are examined. The existence of a universal extinction curve with power law index of about 1.8 extending from the near-IR to at least 5 microns appears to be established for both diffuse and dense cloud dust. The polarization yields evidence for some degree of universality in the 1.6-5 micron regime which may be represented by a power law with index 1.5-2.0, encompassing that for extinction. The form of the polarization curve in the IR seems independent of the wavelength at which the degree of polarization peaks in the optical, implying that variations in that wavelength are caused by changes in the optical properties of the particle at blue-visible rather than IR wavelengths. It is argued that the more significant alterations of the grain size distribution from one environment to another occur for the smaller particles. 47 refs

  5. Change Management and its Influence in the Business Environment

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Berim Ramosaj

    2014-12-01

    Full Text Available The changes that are happening in businesses dictate the changes in all kinds of needed resources to develop the organization. The environment in which the organizations operate is in constant change and becomes more and more unpredictable. Managing these changes is a challenge that all enterprises face. The rapid changes that are happening in business are increasing the need to manage these changes. Enterprises have to develop and use different kinds of management models so that they can grow their performance in order to ensure a competitive position in the market. The changes in enterprises sometimes are not accepted by the organization employees, and seem to have negative effects towards them (exemption from work, reduction of working hours, reduction of income. Changes have negative and positive effects. Successful and rational managers can achieve having successful changes and minimizing the negative effects that come due to changes. Changes are vital for organizations so that they can replace the old plans and models with new and successful ones. In this paper we talk about the role and importance of managing the changes, the types of changes, models of changes, the resistance against changes and also the obtained results of the paper are introduced. Literature was used to support the research in the study field, and based on that to explain the role of changes in the business environment. There are quantitative methods and an inductive analysis used in this paper.

  6. Thermal Transgressions and Phanerozoic Extinctions

    Science.gov (United States)

    Worsley, T. R.; Kidder, D. L.

    2007-12-01

    A number of significant Phanerozoic extinctions are associated with marine transgressions that were probably driven by rapid ocean warming. The conditions associated with what we call thermal transgressions are extremely stressful to life on Earth. The Earth system setting associated with end-Permian extinction exemplifies an end-member case of our model. The conditions favoring extreme warmth and sea-level increases driven by thermal expansion are also conducive to changes in ocean circulation that foster widespread anoxia and sulfidic subsurface ocean waters. Equable climates are characterized by reduced wind shear and weak surface ocean circulation. Late Permian and Early Triassic thermohaline circulation differs considerably from today's world, with minimal polar sinking and intensified mid-latitude sinking that delivers sulfate from shallow evaporative areas to deeper water where it is reduced to sulfide. Reduced nutrient input to oceans from land at many of the extinction intervals results from diminished silicate weathering and weakened delivery of iron via eolian dust. The falloff in iron-bearing dust leads to minimal nitrate production, weakening food webs and rendering faunas and floras more susceptible to extinction when stressed. Factors such as heat, anoxia, ocean acidification, hypercapnia, and hydrogen sulfide poisoning would significantly affect these biotas. Intervals of tectonic quiescence set up preconditions favoring extinctions. Reductions in chemical silicate weathering lead to carbon dioxide buildup, oxygen drawdown, nutrient depletion, wind and ocean current abatement, long-term global warming, and ocean acidification. The effects of extinction triggers such as large igneous provinces, bolide impacts, and episodes of sudden methane release are more potent against the backdrop of our proposed preconditions. Extinctions that have characteristics we call for in the thermal transgressions include the Early Cambrian Sinsk event, as well as

  7. Extinction Mapping and Dust-to-Gas Ratios of Nearby Galaxies using LEGUS

    Science.gov (United States)

    Kahre, Lauren; Walterbos, Rene; Kim, Hwihyun; Thilker, David; Lee, Janice; LEGUS Team

    2018-01-01

    Dust is commonly used as a tracer for cold dense gas, either through IR and NIR emission maps or through extinction mapping, and dust abundance and gas metallicity are critical constraints for chemical and galaxy evolution models. Extinction mapping has been used to trace dust column densities in the Milky Way, the Magellanic Clouds, and M31. The maps for M31 use IR and NIR photometry of red giant branch stars, which is more difficult to obtain for more distant galaxies. Work by Kahre et al. (in prep) uses the extinctions derived for individual massive stars using the isochrone-matching method described by Kim et al. (2012) to generate extinction maps for these more distant galaxies.Isochrones of massive stars lie in the same location on a color-color diagram with little dependence on metallicity and luminosity class, so the extinction can be directly derived from the observed photometry. We generate extinction maps using photometry of massive stars from the Hubble Space Telescope for several of the nearly 50 galaxies observed by the Legacy Extragalactic Ultraviolet Survey (LEGUS). The derived extinction maps will allow us to correct ground-based and HST Halpha maps for extinction, and will be used to constrain changes in the dust-to-gas ratio across the galaxy sample and in different star formation, metallicity and morphological environments. Previous studies have found links between galaxy metallicity and the dust-to-gas mass ratio. We present a study of LEGUS galaxies spanning a range of distances, metallicities, and galaxy morphologies, expanding on our previous study of metal-poor dwarfs Holmberg I and II and giant spirals NGC 6503 and NGC 628. We see clear evidence for changes in the dust-to-gas mass ratio with changing metallicity. We also examine changes in the dust-to-gas mass ratio with galactocentric radius. Ultimately, we will provide constraints on the dust-to-gas mass ratio across a wide range of galaxy environments.

  8. Public Agility and Change in a Network Environment

    Directory of Open Access Journals (Sweden)

    Tom van Engers

    2011-03-01

    Full Text Available Preparing for change is increasingly core business for governmental organizations. The networked society and the increasing connectedness of governmental organizations have as much impact on the complexity of the change process as the complexities of the corpus of law. Change is not only driven by changes in the law; changes in the organization’s environment often create a need to redesign business processes, reallocate roles and responsibilities, and reorder tasks. Moreover, preparations for change are not limited to the internal processes and systems of these organizations. Propagation of changes to network partners and redesign of network arrangements can be an enormous challenge. In the AGILE project, we develop a design method, distributed service architecture, and supporting tools that enable organizations - administrative and otherwise - to orchestrate their law-based services in a networked environment. This paper explains the Agile approach and describes some of its key principles.

  9. Climate predictors of late quaternary extinctions

    DEFF Research Database (Denmark)

    Nogués-Bravo, David; Ohlemüller, Ralf; Batra, Persaram

    2010-01-01

    Between 50,000 and 3,000 years before present (BP) 65% of mammal genera weighing over 44 kg went extinct, together with a lower proportion of small mammals. Why species went extinct in such large numbers is hotly debated. One of the arguments proposes that climate changes underlie Late Quaternary...... extinctions, but global quantitative evidence for this hypothesis is still lacking. We test the potential role of global climate change on the extinction of mammals during the Late Quaternary. Our results suggest that continents with the highest climate footprint values, in other words, with climate changes...... of greater magnitudes during the Late Quaternary, witnessed more extinctions than continents with lower climate footprint values, with the exception of South America. Our results are consistent across species with different body masses, reinforcing the view that past climate changes contributed to global...

  10. The Changing Information Needs of Users in Electronic Information Environments.

    Science.gov (United States)

    Kebede, Gashaw

    2002-01-01

    Focuses on the information needs of users that are changing as a results of changes in the availability of information content in electronic form. Highlights the trend and nature of the physical form in which information content is currently being made available for users' access and use in electronic information environments. (Author/LRW)

  11. Business environment change and decision making mechanism of nuclear generators

    International Nuclear Information System (INIS)

    Yamashita, Hiroko

    2010-01-01

    Change magnitude of business environment for Japanese nuclear generators is significant. It is rapidly growing in the last several years. There are possibilities that the change might impact to management model of nuclear generators. In the paper, the impact to management model, especially, decision making mechanism of the generators is discussed. (author)

  12. Evolving information systems: meeting the ever-changing environment

    NARCIS (Netherlands)

    Oei, J.L.H.; Proper, H.A.; Falkenberg, E.D.

    1994-01-01

    To meet the demands of organizations and their ever-changing environment, information systems are required which are able to evolve to the same extent as organizations do. Such a system has to support changes in all time-and application-dependent aspects. In this paper, requirements and a conceptual

  13. Modeling galactic extinction

    OpenAIRE

    Cecchi-Pestellini, C.; Mulas, G.; Casu, S.; Iatì, M. A.; Saija, R.; Cacciola, A.; Borghese, F.; Denti, P.

    2011-01-01

    We present a model for interstellar extinction dust, in which we assume a bimodal distribution of extinction carriers, a dispersion of core-mantle grains, supplemented by a collection of PAHs in free molecular form. We use state-of-the-art methods to calculate the extinction due to macroscopic dust particles, and the absorption cross-sections of PAHs in four different charge states. While successfull for most of observed Galactic extinction curves, in few cases the model cannot provide reliab...

  14. Human harvest, climate change and their synergistic effects drove the Chinese Crested Tern to the brink of extinction

    Directory of Open Access Journals (Sweden)

    Shuihua Chen

    2015-07-01

    Full Text Available Synergistic effect refers to simultaneous actions of separate factors which have a greater total effect than the sum of the individual factor effects. However, there has been a limited knowledge on how synergistic effects occur and individual roles of different drivers are not often considered. Therefore, it becomes quite challenging to manage multiple threatening processes simultaneously in order to mitigate biodiversity loss. In this regard, our hypothesis is, if the traits actually play different roles in the synergistic interaction, conservation efforts could be made more effectively. To understand the synergistic effect and test our hypothesis, we examined the processes associated with the endangerment of critically endangered Chinese Crested Tern (Thalasseus bernsteini, whose total population number was estimated no more than 50. Through monitoring of breeding colonies and investigations into causative factors, combined with other data on human activities, we found that widespread human harvest of seabird eggs and increasing frequency of typhoons are the major factors that threatened the Chinese Crested Tern. Furthermore, 28 percent of breeding failures were due to the synergistic effects in which egg harvest-induced renestings suffered the higher frequent typhoons. In such combined interactions, the egg harvest has clearly served as a proximal factor for the population decline, and the superimposition of enhanced typhoon activity further accelerated the species toward imminent extinction. Our findings suggest that species endangerment, on one hand, should be treated as a synergistic process, while conservation efforts, on the other hand, should focus principally on combatting the threat that triggers synergistic effects.

  15. Modern examples of extinctions

    DEFF Research Database (Denmark)

    Lövei, Gabor L

    2013-01-01

    No species lives forever, and extinction is the ultimate fate of all living species. The fossil record indicates that a recent extinction wave affecting terrestrial vertebrates was parallel with the arrival of modern humans to areas formerly uninhabited by them. These modern instances of extinction...

  16. Preparing for climate change impacts in Norway's built environment

    International Nuclear Information System (INIS)

    Robert Lisoe, K.; Aandahl, G.; Eriksen, S.; Alfsen, K.

    2003-01-01

    This paper provides an overview of the Norwegian climate policy and of the practical implications of preparing Norway for climate change, with special emphasis on the challenges confronting the built environment. Although the Norwegian government has been relatively proactive in instituting measures aimed at halting global climate change, less attention has been paid to the challenge of adapting to climate change. The global climate system is likely to undergo changes, regardless of the implementation of abatement policies under the Kyoto Protocol or other regimes. The full range of impacts resulting from these changes is still uncertain; however, it is becoming increasingly clear that adaptation to climate change is necessary and inevitable within several sectors. The potential impacts of climate change in the built environment are now being addressed. Both the functionality of the existing built environment and the design of future buildings are likely to be altered by climate change impacts, and the expected implications of these new conditions are now investigated. However, measures aimed at adjustments within individual sectors, such as altering the criteria and codes of practice for the design and construction of buildings, constitute only a partial adaptation to climate change. In order to adapt effectively, larger societal and intersectoral adjustments are necessary. (author)

  17. The extinction of the dinosaurs.

    Science.gov (United States)

    Brusatte, Stephen L; Butler, Richard J; Barrett, Paul M; Carrano, Matthew T; Evans, David C; Lloyd, Graeme T; Mannion, Philip D; Norell, Mark A; Peppe, Daniel J; Upchurch, Paul; Williamson, Thomas E

    2015-05-01

    Non-avian dinosaurs went extinct 66 million years ago, geologically coincident with the impact of a large bolide (comet or asteroid) during an interval of massive volcanic eruptions and changes in temperature and sea level. There has long been fervent debate about how these events affected dinosaurs. We review a wealth of new data accumulated over the past two decades, provide updated and novel analyses of long-term dinosaur diversity trends during the latest Cretaceous, and discuss an emerging consensus on the extinction's tempo and causes. Little support exists for a global, long-term decline across non-avian dinosaur diversity prior to their extinction at the end of the Cretaceous. However, restructuring of latest Cretaceous dinosaur faunas in North America led to reduced diversity of large-bodied herbivores, perhaps making communities more susceptible to cascading extinctions. The abruptness of the dinosaur extinction suggests a key role for the bolide impact, although the coarseness of the fossil record makes testing the effects of Deccan volcanism difficult. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

  18. Phylogeography of screaming hairy armadillo Chaetophractus vellerosus: Successive disjunctions and extinctions due to cyclical climatic changes in southern South America.

    Directory of Open Access Journals (Sweden)

    Sebastián Poljak

    Full Text Available Little is known about phylogeography of armadillo species native to southern South America. In this study we describe the phylogeography of the screaming hairy armadillo Chaetophractus vellerosus, discuss previous hypothesis about the origin of its disjunct distribution and propose an alternative one, based on novel information on genetic variability. Variation of partial sequences of mitochondrial DNA Control Region (CR from 73 individuals from 23 localities were analyzed to carry out a phylogeographic analysis using neutrality tests, mismatch distribution, median-joining (MJ network and paleontological records. We found 17 polymorphic sites resulting in 15 haplotypes. Two new geographic records that expand known distribution of the species are presented; one of them links the distributions of recently synonimized species C. nationi and C. vellerosus. Screaming hairy armadillo phylogeographic pattern can be addressed as category V of Avise: common widespread linages plus closely related lineages confined to one or a few nearby locales each. The older linages are distributed in the north-central area of the species distribution range in Argentina (i.e. ancestral area of distribution. C. vellerosus seems to be a low vagility species that expanded, and probably is expanding, its distribution range while presents signs of genetic structuring in central areas. To explain the disjunct distribution, a hypothesis of extinction of the species in intermediate areas due to quaternary climatic shift to more humid conditions was proposed. We offer an alternative explanation: long distance colonization, based on null genetic variability, paleontological record and evidence of alternance of cold/arid and temperate/humid climatic periods during the last million years in southern South America.

  19. Phylogeography of screaming hairy armadillo Chaetophractus vellerosus: Successive disjunctions and extinctions due to cyclical climatic changes in southern South America.

    Science.gov (United States)

    Poljak, Sebastián; Ferreiro, Alejandro M; Chiappero, Marina B; Sánchez, Julieta; Gabrielli, Magalí; Lizarralde, Marta S

    2018-01-01

    Little is known about phylogeography of armadillo species native to southern South America. In this study we describe the phylogeography of the screaming hairy armadillo Chaetophractus vellerosus, discuss previous hypothesis about the origin of its disjunct distribution and propose an alternative one, based on novel information on genetic variability. Variation of partial sequences of mitochondrial DNA Control Region (CR) from 73 individuals from 23 localities were analyzed to carry out a phylogeographic analysis using neutrality tests, mismatch distribution, median-joining (MJ) network and paleontological records. We found 17 polymorphic sites resulting in 15 haplotypes. Two new geographic records that expand known distribution of the species are presented; one of them links the distributions of recently synonimized species C. nationi and C. vellerosus. Screaming hairy armadillo phylogeographic pattern can be addressed as category V of Avise: common widespread linages plus closely related lineages confined to one or a few nearby locales each. The older linages are distributed in the north-central area of the species distribution range in Argentina (i.e. ancestral area of distribution). C. vellerosus seems to be a low vagility species that expanded, and probably is expanding, its distribution range while presents signs of genetic structuring in central areas. To explain the disjunct distribution, a hypothesis of extinction of the species in intermediate areas due to quaternary climatic shift to more humid conditions was proposed. We offer an alternative explanation: long distance colonization, based on null genetic variability, paleontological record and evidence of alternance of cold/arid and temperate/humid climatic periods during the last million years in southern South America.

  20. Extinction produces context inhibition and multiple-context extinction reduces response recovery in human predictive learning.

    Science.gov (United States)

    Glautier, Steven; Elgueta, Tito; Nelson, James Byron

    2013-12-01

    Two experiments with human participants were used to investigate recovery of an extinguished learned response after a context change using ABC designs. In an ABC design, the context changes over the three successive stages of acquisition (context A), extinction (context B), and test (context C). In both experiments, we found reduced recovery in groups that had extinction in multiple contexts, and that the extinction contexts acquired inhibitory strength. These results confirm those of previous investigations, that multiple-context extinction can produce less response recovery than single-context extinction, and they also provide new evidence for the involvement of contextual inhibitory processes in extinction in humans. The foregoing results are broadly in line with a protection-from-extinction account of response recovery. Yet, despite the fact that we detected contextual inhibition, predictions based on protection-from-extinction were not fully reliable for the single- and multiple-context group differences that we observed in (1) rates of extinction and (2) the strength of context inhibition. Thus, although evidence was obtained for a protection-from-extinction account of response recovery, this account can not explain all of the data.

  1. Confronting the Consequences of a Permanent Changing Environment

    Directory of Open Access Journals (Sweden)

    Raluca Ioana Vosloban

    2013-05-01

    Full Text Available Businesses and governments choose how they wish to deal with change. Whether this change is organizational, technological, political, financial etc or even individual pursuing actions as usual is likely to lead to a downward path. The authors of this paper are giving a set of tools for confronting and understanding the consequences of this era of permanent changes by building strengths and seeking opportunities within organizations (private or public and within family (including friends. The work environment and the personal life of the individual have a common point which is adaptability, coping efficiently with changes, a demanded ability of the 3rd millennium human being.

  2. Abrupt Climatic Change during the Latest Maastrichtian: Establishing Robust Temporal Links with the Onset of Deccan Volcanism and K/Pg Mass Extinction

    Science.gov (United States)

    Barnet, J.; Littler, K.; Kroon, D.; Leng, M. J.; Westerhold, T.; Roehl, U.; Zachos, J. C.

    2017-12-01

    A transient period of climate change, characterized by a global warming of 2.5-5°C followed by a cooling to pre-excursion conditions, occurred during the last 300 kyr of the Maastrichtian ( 66.34-66.02 Ma). This instability may have played a role in destabilizing marine and terrestrial ecosystems, priming the system for abrupt extinction at the K-Pg boundary, likely triggered by a large bolide impact. This pre-K-Pg warming event has often been linked to the main phase of Deccan Trap volcanism, however large uncertainties associated with radio-isotopic dating methods of basalts, along with low sedimentation rates and hiatuses in many studied sedimentary sequences, have long hampered a definitive correlation. To complement recent advances in dating of the traps, we have generated the first complete and highest resolution (2.5-4 kyr) benthic stable δ13C and δ18O record for the final million years of the Maastrichtian using the epifaunal foraminifera species Nuttallides truempyi from ODP Site 1262, Walvis Ridge, South Atlantic, calibrated to an updated orbitally-tuned age model. We then compare our data to other previously published geochemical data from other sites in the high, middle, and low latitudes. Our data confirms that the onset of the warming event coincides with the onset of the main phase of Deccan volcanism, strongly suggesting a causal link. Furthermore, spectral analysis of our extended late Maastrichtian-Early Eocene record suggests that the onset of the warming event corresponds to a 405-kyr eccentricity minima, in contrast to many transient warming events (hyperthermals) of the Paleogene, suggesting a control by orbital forcing alone is unlikely. A peculiar feature of the event, compared to other hyperthermals, is a muted carbon cycle response during warming, which may be related to the comparatively heavier δ13C signature of volcanogenic CO2 (-7‰), compared to other sources of light carbon invoked to explain Paleogene hyperthermals. The warming

  3. Climate Change and Integrodifference Equations in a Stochastic Environment.

    Science.gov (United States)

    Bouhours, Juliette; Lewis, Mark A

    2016-09-01

    Climate change impacts population distributions, forcing some species to migrate poleward if they are to survive and keep up with the suitable habitat that is shifting with the temperature isoclines. Previous studies have analysed whether populations have the capacity to keep up with shifting temperature isoclines, and have mathematically determined the combination of growth and dispersal that is needed to achieve this. However, the rate of isocline movement can be highly variable, with much uncertainty associated with yearly shifts. The same is true for population growth rates. Growth rates can be variable and uncertain, even within suitable habitats for growth. In this paper, we reanalyse the question of population persistence in the context of the uncertainty and variability in isocline shifts and rates of growth. Specifically, we employ a stochastic integrodifference equation model on a patch of suitable habitat that shifts poleward at a random rate. We derive a metric describing the asymptotic growth rate of the linearised operator of the stochastic model. This metric yields a threshold criterion for population persistence. We demonstrate that the variability in the yearly shift and in the growth rate has a significant negative effect on the persistence in the sense that it decreases the threshold criterion for population persistence. Mathematically, we show how the persistence metric can be connected to the principal eigenvalue problem for a related integral operator, at least for the case where isocline shifting speed is deterministic. Analysis of dynamics for the case where the dispersal kernel is Gaussian leads to the existence of a critical shifting speed, above which the population will go extinct, and below which the population will persist. This leads to clear bounds on rate of environmental change if the population is to persist. Finally, we illustrate our different results for butterfly population using numerical simulations and demonstrate how

  4. [Animals' clever adaptation strategy for seasonal changes in environment].

    Science.gov (United States)

    Ikegami, Keisuke; Yoshimura, Takashi

    2015-08-01

    Organisms living outside of tropical zones experience seasonal changes in environment. Organisms are using day length as a calendar to change their physiology and behavior such as seasonal breeding, hibernation, migration, and molting. A comparative biology approach revealed underlying mechanisms of vertebrate seasonal reproduction. Here we review the current understanding of vertebrate seasonal reproduction. We Aso describe the involvement of tissue-specific post-translational modification in functional diversification of a hormone.

  5. The Changing Fiscal Environment for Academic Veterinary Medicine.

    Science.gov (United States)

    Zimmel, Dana N; Lloyd, James W

    2015-01-01

    The fiscal environment for academic veterinary medicine has changed substantially over the past 50 years. Understanding the flux of state and federal government support and the implications for student debt, academic programs, and scholarly work is critical for planning for the future. The recent precipitous decline in public funding highlights the urgent need to develop and maintain an economically sustainable model that can adapt to the changing landscape and serve societal needs.

  6. Sudden transition and sudden change from open spin environments

    International Nuclear Information System (INIS)

    Hu, Zheng-Da; Xu, Jing-Bo; Yao, Dao-Xin

    2014-01-01

    We investigate the necessary conditions for the existence of sudden transition or sudden change phenomenon for appropriate initial states under dephasing. As illustrative examples, we study the behaviors of quantum correlation dynamics of two noninteracting qubits in independent and common open spin environments, respectively. For the independent environments case, we find that the quantum correlation dynamics is closely related to the Loschmidt echo and the dynamics exhibits a sudden transition from classical to quantum correlation decay. It is also shown that the sudden change phenomenon may occur for the common environment case and stationary quantum discord is found at the high temperature region of the environment. Finally, we investigate the quantum criticality of the open spin environment by exploring the probability distribution of the Loschmidt echo and the scaling transformation behavior of quantum discord, respectively. - Highlights: • Sudden transition or sudden change from open spin baths are studied. • Quantum discord is related to the Loschmidt echo in independent open spin baths. • Steady quantum discord is found in a common open spin bath. • The probability distribution of the Loschmidt echo is analyzed. • The scaling transformation behavior of quantum discord is displayed

  7. Bimodal extinction without cross-modal extinction.

    OpenAIRE

    Inhoff, A W; Rafal, R D; Posner, M J

    1992-01-01

    Three patients with unilateral neurological injury were clinically examined. All showed consistent unilateral extinction in the tactile and visual modalities on simultaneous intramodal stimulation. There was virtually no evidence for cross-modal extinction, however, so that contralateral stimulation of one modality would have extinguished perception of ipsilateral stimuli in the other modality. It is concluded that the attentional system controlling the encoding of tactile and visual stimuli ...

  8. Evidence Accumulation and Change Rate Inference in Dynamic Environments.

    Science.gov (United States)

    Radillo, Adrian E; Veliz-Cuba, Alan; Josić, Krešimir; Kilpatrick, Zachary P

    2017-06-01

    In a constantly changing world, animals must account for environmental volatility when making decisions. To appropriately discount older, irrelevant information, they need to learn the rate at which the environment changes. We develop an ideal observer model capable of inferring the present state of the environment along with its rate of change. Key to this computation is an update of the posterior probability of all possible change point counts. This computation can be challenging, as the number of possibilities grows rapidly with time. However, we show how the computations can be simplified in the continuum limit by a moment closure approximation. The resulting low-dimensional system can be used to infer the environmental state and change rate with accuracy comparable to the ideal observer. The approximate computations can be performed by a neural network model via a rate-correlation-based plasticity rule. We thus show how optimal observers accumulate evidence in changing environments and map this computation to reduced models that perform inference using plausible neural mechanisms.

  9. A Parable of Small Animals and Megafauna Extinction: A Paleo-Economic Theory of Climate Change versus Human Overkill in the Pleistocene

    NARCIS (Netherlands)

    Bulte, E.H.; Horan, R.D.; Shogren, J.F.

    2006-01-01

    After centuries of debate, paleontologists are converging towards the conclusion that human overkill caused the massive extinction of large mammals in the late Pleistocene. This paper revisits the question of megafauna extinction by incorporating economic behavior into the debate. We allow for

  10. Thermal sensation and thermal comfort in changing environments

    NARCIS (Netherlands)

    Velt, K.B.; Daanen, H.A.M.

    2017-01-01

    It is the purpose of this study to investigate thermal sensation (TS) and thermal comfort (TC) in changing environments. Therefore, 10 subjects stayed in a 30 °C, 50% relative humidity for 30 min in summer clothes and then moved to a 20 °C room where they remained seated for 30 min (Hot to Reference

  11. Climate Change Impacts on the Built Environment in Nigeria ...

    African Journals Online (AJOL)

    The populations, infrastructure and ecology of cities are at risk from the impacts of climate change which affect urban ventilation and cooling, urban drainage and flood risk and water resources. Built areas exert considerable influence over their local climate and environment, and urban populations are already facing a ...

  12. Review: The impact of changing human environment and climate ...

    African Journals Online (AJOL)

    The impact of human-induced climate change through industrialization with the consequent depletion of the ozone layer of the environment is now observed to compromise the sustainability of human development as it threatens the ecological support system on which life depends in addition to encouraging the emergence ...

  13. Academic Training: Climate change and challenges for the environment / POSTPONED!!!

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 20, 21, 22 June 20, 21, 22 June, from 11:00 to 12:00 – Main Auditorium, bldg. 500 Climate change and challenges for the environment C. SCHLUECHTER / Univ. Bern, CH The Academic Training is postponed.

  14. The quality of political news in a changing media environment

    NARCIS (Netherlands)

    Jacobi, C.A.

    2016-01-01

    What do ongoing changes in the media environment, notably the perceived popularization of news and the shift towards individualized online media, mean for political news quality, both in terms of what it is, as well as how we measure it? This dissertation firstly argues, based on a literature review

  15. An ontological framework for requirement change management in distributed environment

    International Nuclear Information System (INIS)

    Khatoon, A.; Hafeez, Y.; Ali, T.

    2014-01-01

    Global Software Development (GSD) is getting fame in the software industry gradually. However, in GSD, multiple and diverse stakeholders are involved in the development of complex software systems. GSD introduces several challenges, i.e. physical distance, time zone, culture difference, language barriers. As requirements play a significant role in any software development. The greatest challenge in GSD environment is to maintain a consistent view of the system even if the requirements change. But at the same time single change in the requirement might affect several other modules. In GSD different people use terms and have different ways of expressing the concepts for which people at remote sites are unable to get uniformity regarding the semantics of the terms. In a global environment requires effective communication and coordination. However, to overcome inconsistencies and ambiguities among the team members and to make the team members aware of the consistent view, a shared and common understanding is required. In this paper an approach beneficial to software industry has been proposed, focusing on changing requirements in a Global Software Development environment. A case study has been used for the evaluation of the proposed approach. Therefore, Requirements change management process has been improved by applying the approach of the case study. The proposed approach is beneficial to the software development organizations where frequent changes occur. It guided the software industry to provide the common understandings to all the development teams residing in remote locations. (author)

  16. Change in the family food environment is associated with positive dietary change in children.

    Science.gov (United States)

    Hendrie, Gilly; Sohonpal, Gundeep; Lange, Kylie; Golley, Rebecca

    2013-01-07

    The family food environment is an important influence in the development of children's dietary habits. Research suggests that influences of current dietary behaviour and behaviour change may differ. The aims of this paper were to: (1) investigate the association between the food environment at baseline and change in children's saturated fat intake; and (2) to explore whether a change in the food environment was associated with a change in children's saturated fat intake. Secondary analysis of a 12 week cluster randomised controlled trial in 133 4-13 year old children. Families were randomly allocated to parental education regarding changing to reduced-fat dairy foods or a comparison non-dietary behaviour. The interventions were family focused. Parents received education from a dietitian in 3x30 minute sessions to facilitate behaviour change. Parents completed a comprehensive questionnaire capturing three domains of the food environment--Parent knowledge and attitudes; shaping practices; and behaviours and role modelling. Children's dietary intake was assessed via multiple 24-hour recalls at baseline and week 12. Changes in the family food environment and primary outcome (saturated fat) were calculated. Hierarchical linear regression models were performed to explore the association between baseline and change in food environment constructs and change in saturated fat intake. Standardised Beta are presented (pchange in saturated fat. An increase in nutrition knowledge (β=-0.2), perceived responsibility (β=-0.3) and restriction (β=-0.3) from baseline to week 12 were associated with greater reduction in saturated fat intake. The present study was one of the first to quantify changes in the family food environment, and identify a number of factors which were associated with a positive dietary change. Because interventions focus on behaviour change, the findings may provide specific targets for intervention strategies in the future. Australia New Zealand Clinical

  17. Extinction Risk of Phytoplankton Species to Potential Killing Mechanisms at the Cretaceous-Paleogene Boundary

    Science.gov (United States)

    Bralower, T. J.; Schueth, J.; Jiang, S.

    2013-05-01

    The impact at Chicxulub caused catastrophic changes in marine habitats including extended darkness, ocean acidification and eutrophication. These changes were devastating to some groups of phytoplankton at the base of the marine food chain while others escaped virtually unscathed. For example, diatoms had ~85% survival across the boundary and dinoflagellates actually increased in diversity. These non-calcareous plankton most likely survived due to their adaptation to high-stress environments and their ability to form spores and resting cysts. The calcareous nannoplankton, however, were decimated with approximately 85% of genera and 93% of species going extinct. Nannoplankton generally lack the ability to encyst and thus, as a group, would have been susceptible to darkness, ocean acidification and eutrophication. However, we still do not fully understand why certain nannofossil taxa survived while others went extinct. Extinction risk, the projected susceptibility of a taxon to extinction based on its ecology and ability to adapt, is a concept that is widely applied to extant species and higher order fossil groups, but not to phytoplankton. This concept is a useful for probing the selectivity of ancient species to mass extinction. Determining the extinction risk of latest Maastrichtian nannoplankton species would be a step towards understanding the selection of survivors. The deep-sea record contains a remarkable archive of nannoplankton extinction and recovery across the Cretaceous-Paleogene boundary. The recovery was geologically extended, enabling detailed comparisons between the ocean basins. A large, global database of assemblages had led to the discovery that the Northern Hemisphere oceans suffered higher nannoplankton extinction rates than the Southern Hemisphere with an ecological "crisis" that lasted for approximately 350 thousand years after the impact. In addition, incumbency played a major role in the origination of new species. Since extinction almost

  18. An allometric approach to quantify the extinction vulnerability of birds and mammals.

    Science.gov (United States)

    Hilbers, J P; Schipper, A M; Hendriks, A J; Verones, F; Pereira, H M; Huijbregts, M A J

    2016-03-01

    -specific information. The framework facilitates the estimation of extinction vulnerabilities of data-deficient species. It may be applied to forecast extinction vulnerability in response to a changing environment, by incorporating quantitative relationships between wildlife demographic parameters and environmental drivers like habitat alteration, climate change, or hunting.

  19. Critical perspectives on changing media environments in the Global South

    DEFF Research Database (Denmark)

    Nielsen, Poul Erik

    the changes in the media landscape continuously alter the power balance between state, civil society and market. At the meso level, these changes will be discussed in relation to the development of the different media and of a variety of new locally specific media environments, which create new spaces......The main aim of this article is to give a general overview and theoretically discuss how significant changes in the media landscapes in Global South countries alter existing spaces and create new spaces for political and socio-cultural exchange, thus changing the complex interrelationship between...... media and society. Knowing that media is only one of many aspects in current societal changes, the focus will be more on the interrelationship between media and society and less on other aspects like globalization, education and political reforms. At the macro level, the article will discuss how...

  20. The Late Ordovician Extinction: How it became the best understood of the five major extinctions.

    Science.gov (United States)

    Sheehan, P.

    2003-04-01

    The end Ordovician extinction has become arguably the best-understood major extinction event in Earth History. A plethora of workers have established the pattern of faunal change and causes of the extinction with remarkably little disagreement. The first indication of increased extinction at the end of the Ordovician was a graph of global diversity patterns by Norman Newell in 1967, although he did not recognize it as a major event. The presence of a major extinction event became clear as William Berry and Art Boucot assembled data for Silurian correlation charts in the late 1960s. The first reports of North African glaciation in the late 1960s provided a cause for the extinction and study of the event snowballed. It was no accident that recognition of the extinction began in North America, because it was there that the extinction completely overturned faunas in the epicontinental seas. Glacio-eustatic regression of shallow seaway coincided with the disappearance of endemic Laurentian faunas and replacement by a highly cosmopolitan fauna in the Silurian. Once the event was established in North America, paleontologists soon found evidence of the event around the globe. The well-documented Hirnantia Fauna was found to correspond to the glacial interval, and Pat Brenchley soon recognized that there were two pulses of extinction, at the beginning and end of the glaciation. At the same time that the faunal changes were being documented geologic studies of the glaciation provided information on the environmental changes associated with the extinction. The timing of the glacial maximum was established in Africa and by the presence of dropstones in high latitude marine rocks. The 1990s saw geochemical techniques employed that allowed examination of atmospheric CO2 and temperature changes. In many places carbonate deposition declined. Glacio-eustatic regression was obvious in many areas, and a sea-level decline in the range of 50-100 m was established. Shallow

  1. Extinction with multiple excitors

    OpenAIRE

    McConnell, Bridget L.; Miguez, Gonzalo; Miller, Ralph R.

    2013-01-01

    Four conditioned suppression experiments with rats, using an ABC renewal design, investigated the effects of compounding the target conditioned excitor with additional, nontarget conditioned excitors during extinction. Experiment 1 showed stronger extinction, as evidenced by less renewal, when the target excitor was extinguished in compound with a second excitor, relative to when it was extinguished with associatively neutral stimuli. Critically, this deepened extinction effect was attenuated...

  2. The DIII-D Computing Environment: Characteristics and Recent Changes

    International Nuclear Information System (INIS)

    McHarg, B.B. Jr.

    1999-01-01

    The DIII-D tokamak national fusion research facility along with its predecessor Doublet III has been operating for over 21 years. The DIII-D computing environment consists of real-time systems controlling the tokamak, heating systems, and diagnostics, and systems acquiring experimental data from instrumentation; major data analysis server nodes performing short term and long term data access and data analysis; and systems providing mechanisms for remote collaboration and the dissemination of information over the world wide web. Computer systems for the facility have undergone incredible changes over the course of time as the computer industry has changed dramatically. Yet there are certain valuable characteristics of the DIII-D computing environment that have been developed over time and have been maintained to this day. Some of these characteristics include: continuous computer infrastructure improvements, distributed data and data access, computing platform integration, and remote collaborations. These characteristics are being carried forward as well as new characteristics resulting from recent changes which have included: a dedicated storage system and a hierarchical storage management system for raw shot data, various further infrastructure improvements including deployment of Fast Ethernet, the introduction of MDSplus, LSF and common IDL based tools, and improvements to remote collaboration capabilities. This paper will describe this computing environment, important characteristics that over the years have contributed to the success of DIII-D computing systems, and recent changes to computer systems

  3. Confounding environmental colour and distribution shape leads to underestimation of population extinction risk.

    Directory of Open Access Journals (Sweden)

    Mike S Fowler

    Full Text Available The colour of environmental variability influences the size of population fluctuations when filtered through density dependent dynamics, driving extinction risk through dynamical resonance. Slow fluctuations (low frequencies dominate in red environments, rapid fluctuations (high frequencies in blue environments and white environments are purely random (no frequencies dominate. Two methods are commonly employed to generate the coloured spatial and/or temporal stochastic (environmental series used in combination with population (dynamical feedback models: autoregressive [AR(1] and sinusoidal (1/f models. We show that changing environmental colour from white to red with 1/f models, and from white to red or blue with AR(1 models, generates coloured environmental series that are not normally distributed at finite time-scales, potentially confounding comparison with normally distributed white noise models. Increasing variability of sample Skewness and Kurtosis and decreasing mean Kurtosis of these series alter the frequency distribution shape of the realised values of the coloured stochastic processes. These changes in distribution shape alter patterns in the probability of single and series of extreme conditions. We show that the reduced extinction risk for undercompensating (slow growing populations in red environments previously predicted with traditional 1/f methods is an artefact of changes in the distribution shapes of the environmental series. This is demonstrated by comparison with coloured series controlled to be normally distributed using spectral mimicry. Changes in the distribution shape that arise using traditional methods lead to underestimation of extinction risk in normally distributed, red 1/f environments. AR(1 methods also underestimate extinction risks in traditionally generated red environments. This work synthesises previous results and provides further insight into the processes driving extinction risk in model populations. We

  4. Confounding environmental colour and distribution shape leads to underestimation of population extinction risk.

    Science.gov (United States)

    Fowler, Mike S; Ruokolainen, Lasse

    2013-01-01

    The colour of environmental variability influences the size of population fluctuations when filtered through density dependent dynamics, driving extinction risk through dynamical resonance. Slow fluctuations (low frequencies) dominate in red environments, rapid fluctuations (high frequencies) in blue environments and white environments are purely random (no frequencies dominate). Two methods are commonly employed to generate the coloured spatial and/or temporal stochastic (environmental) series used in combination with population (dynamical feedback) models: autoregressive [AR(1)] and sinusoidal (1/f) models. We show that changing environmental colour from white to red with 1/f models, and from white to red or blue with AR(1) models, generates coloured environmental series that are not normally distributed at finite time-scales, potentially confounding comparison with normally distributed white noise models. Increasing variability of sample Skewness and Kurtosis and decreasing mean Kurtosis of these series alter the frequency distribution shape of the realised values of the coloured stochastic processes. These changes in distribution shape alter patterns in the probability of single and series of extreme conditions. We show that the reduced extinction risk for undercompensating (slow growing) populations in red environments previously predicted with traditional 1/f methods is an artefact of changes in the distribution shapes of the environmental series. This is demonstrated by comparison with coloured series controlled to be normally distributed using spectral mimicry. Changes in the distribution shape that arise using traditional methods lead to underestimation of extinction risk in normally distributed, red 1/f environments. AR(1) methods also underestimate extinction risks in traditionally generated red environments. This work synthesises previous results and provides further insight into the processes driving extinction risk in model populations. We must let

  5. Human activities and climate and environment changes: an inevitable relation

    International Nuclear Information System (INIS)

    Sanchez, Aretha

    2009-01-01

    The human interference in the environment and the consequent climate change is today a consensus. The climate change can be local, regional and global. The global climate change is mainly caused by the greenhouse gases, and consequently the climate change intervenes in the environment. The interference cycle emerges in several forms and results in several consequences. However, the Global Warming has certainly the most import global impact. The main cause of the increase in the temperature (Greenhouse Effect) is the intensive use of the fossil fuels. Thus, to minimize the climatic changes actions are necessary to reduce, to substitute and to use with more efficient the fossil fuels. Looking at the past, the old agriculturists may have released greenhouse gases since thousand years ago, thus, modifying slowly but in significant form the earth climate much before the Industrial Age. If this theory is confirmed, its consequences would be decisive for the man history in the planet. For example, in parts of the North America and Europe the current temperatures could be even four Celsius degrees smaller. This change in temperature is enough to hinder agricultural used of these regions and consequently to diminish the human development. The main focus of this work is to perform a retrospective in some of civilizations who collapse due to environmental problems and make a historical description of the human activities (agriculture and livestock) since the primordium of the man up to the Industrial Age, aiming at the man interference on the natural dynamics of the global climate and the environment. This work will show through data comparisons and inferences that the gases emissions from these activities had a significant magnitude comparatively by the emissions after the Industrial Age. It is also demonstrated that the climate and environment interference was inevitable because the human evolution was caused by these activities. Another important point of this work is to

  6. Testing take-the-best in new and changing environments.

    Science.gov (United States)

    Lee, Michael D; Blanco, Gabrielle; Bo, Nikole

    2017-08-01

    Take-the-best is a decision-making strategy that chooses between alternatives, by searching the cues representing the alternatives in order of cue validity, and choosing the alternative with the first discriminating cue. Theoretical support for take-the-best comes from the "fast and frugal" approach to modeling cognition, which assumes decision-making strategies need to be fast to cope with a competitive world, and be simple to be robust to uncertainty and environmental change. We contribute to the empirical evaluation of take-the-best in two ways. First, we generate four new environments-involving bridge lengths, hamburger prices, theme park attendances, and US university rankings-supplementing the relatively limited number of naturally cue-based environments previously considered. We find that take-the-best is as accurate as rival decision strategies that use all of the available cues. Secondly, we develop 19 new data sets characterizing the change in cities and their populations in four countries. We find that take-the-best maintains its accuracy and limited search as the environments change, even if cue validities learned in one environment are used to make decisions in another. Once again, we find that take-the-best is as accurate as rival strategies that use all of the cues. We conclude that these new evaluations support the theoretical claims of the accuracy, frugality, and robustness for take-the-best, and that the new data sets provide a valuable resource for the more general study of the relationship between effective decision-making strategies and the environments in which they operate.

  7. Precision Security: Integrating Video Surveillance with Surrounding Environment Changes

    Directory of Open Access Journals (Sweden)

    Wenfeng Wang

    2018-01-01

    Full Text Available Video surveillance plays a vital role in maintaining the social security although, until now, large uncertainty still exists in danger understanding and recognition, which can be partly attributed to intractable environment changes in the backgrounds. This article presents a brain-inspired computing of attention value of surrounding environment changes (EC with a processes-based cognition model by introducing a ratio value λ of EC-implications within considered periods. Theoretical models for computation of warning level of EC-implications to the universal video recognition efficiency (quantified as time cost of implication-ratio variations from λk to λk+1, k=1,2,… are further established. Imbedding proposed models into the online algorithms is suggested as a future research priority towards precision security for critical applications and, furthermore, schemes for a practical implementation of such integration are also preliminarily discussed.

  8. Changing the Environment Based on Empowerment as Intrinsic Motivation

    Directory of Open Access Journals (Sweden)

    Christoph Salge

    2014-05-01

    Full Text Available One aspect of intelligence is the ability to restructure your own environment so that the world you live in becomes more beneficial to you. In this paper we investigate how the information-theoretic measure of agent empowerment can provide a task-independent, intrinsic motivation to restructure the world. We show how changes in embodiment and in the environment change the resulting behaviour of the agent and the artefacts left in the world. For this purpose, we introduce an approximation of the established empowerment formalism based on sparse sampling, which is simpler and significantly faster to compute for deterministic dynamics. Sparse sampling also introduces a degree of randomness into the decision making process, which turns out to beneficial for some cases. We then utilize the measure to generate agent behaviour for different agent embodiments in a Minecraft-inspired three dimensional block world. The paradigmatic results demonstrate that empowerment can be used as a suitable generic intrinsic motivation to not only generate actions in given static environments, as shown in the past, but also to modify existing environmental conditions. In doing so, the emerging strategies to modify an agent’s environment turn out to be meaningful to the specific agent capabilities, i.e., de facto to its embodiment.

  9. Climate change on arctic environment, ecosystem services and society (CLICHE)

    Science.gov (United States)

    Weckström, J.; Korhola, A.; Väliranta, M.; Seppä, H.; Luoto, M.; Tuittila, E.-S.; Leppäranta, M.; Kahilainen, K.; Saarinen, J.; Heikkinen, H.

    2012-04-01

    The predicted climate warming has raised many questions and concerns about its impacts on the environment and society. As a respond to the need of holistic studies comprising both of these areas, The Academy of Finland launched The Finnish Research Programme on Climate Change (FICCA 2011-2014) in spring 2010 with the main aim to focus on the interaction between the environment and society. Ultimately 11 national consortium projects were funded (total budget 12 million EUR). Here we shortly present the main objectives of the largest consortium project "Climate change on arctic environment, ecosystem services and society" (CLICHE). The CLICHE consortium comprises eight interrelated work packages (treeline, diversity, peatlands, snow, lakes, fish, tourism, and traditional livelihoods), each led by a prominent research group and a team leader. The research consortium has three main overall objectives: 1) Investigate, map and model the past, present and future climate change-induced changes in central ecosystems of the European Arctic with unprecedented precision 2) Deepen our understanding of the basic principles of ecosystem and social resilience and dynamics; identify key taxa, structures or processes that clearly indicate impending or realised global change through their loss, occurrence or behaviour, using analogues from the past (e.g. Holocene Thermal Maximum, Medieval Warm Period), experiments, observations and models 3) Develop adaptation and mitigation strategies to minimize the adverse effects of climate change on local communities, traditional livelihoods, fisheries, and tourism industry, and promote sustainable development of local community structures and enhance the quality of life of local human populations. As the project has started only recently no final results are available yet. However, the fieldwork as well as the co-operation between the research teams has thus far been very successful. Thus, the expectations for the final outcome of the project

  10. Evenness and species abundance in graptolite communities: a new proxy for climate change during the end ordovician mass extinction

    Czech Academy of Sciences Publication Activity Database

    Hawkins, A. D.; Mitchell, C. E.; Sheets, H. D.; Loxton, J.; Belscher, K.; Melchin, M. J.; Finney, S.; Štorch, Petr

    2011-01-01

    Roč. 43, č. 5 (2011), s. 83-83 ISSN 0016-7592. [2011 GSA Annual Meeting and Exposition. 09.10.2011-12.10.2011, Minneapolis] Institutional research plan: CEZ:AV0Z30130516 Keywords : graptolites * Ordovician * climate change Subject RIV: DB - Geology ; Mineralogy http://gsa.confex.com/gsa/2011AM/finalprogram/abstract_196574.htm

  11. Perceptual classification in a rapidly-changing environment

    OpenAIRE

    Summerfield, Christopher; Behrens, Timothy E.; Koechlin, Etienne

    2011-01-01

    Humans and monkeys can learn to classify perceptual information in a statistically optimal fashion if the functional groupings remain stable over many hundreds of trials, but little is known about categorisation when the environment changes rapidly. Here, we used a combination of computational modelling and functional neuroimaging to understand how humans classify visual stimuli drawn from categories whose mean and variance jumped unpredictably. Models based on optimal learning (Bayesian mode...

  12. Recreation and tourism induced changes in northern boreal environments

    OpenAIRE

    Kangas, K. (Katja)

    2009-01-01

    Abstract The popularity of nature-based tourism has increased worldwide and peripheral areas with conservational value, like protected areas, are attractive destinations. The recreational use and construction of tourism facilities can cause environmental degradation and decrease the conservational and recreational value of areas if not well planned and managed. The aim of this thesis was to improve our knowledge of recreation and tourism induced changes in northern boreal environments. Dir...

  13. Postprandial changes in the exhalation of radon from the environment

    International Nuclear Information System (INIS)

    Rundo, J.; Markun, F.; Plondke, N.J.

    1978-01-01

    The exhalation of radon originally inhaled from the home environment and dissolved in body fluids and tissues has been studied serially for periods of several hours in six persons. The observation of a pronounced postprandial peak in the rate of exhalation of radon shows that the similar peak observed in the exhalation of radon produced from radium in vivo results from the flushing of a reservoir in soft tissue and not from a change in the fraction lost from bone

  14. Sustainability of biomass utilisation in changing operational environment - SUBICHOE

    Energy Technology Data Exchange (ETDEWEB)

    Soimakallio, S. [VTT Technical Research Centre of Finland, Espoo (Finland)], email: sampo.soimakallio@vtt.fi

    2012-07-01

    The main objective of the project was to assist in strategic decision-making of public administration and companies, as regards the most sustainable use of biomass, by taking into account the changing operational environment. This project continued the work of the BIOVAIKU project by exploring in more details the most critical issues identified in sustainability assessment. These include the need to develop assessment methods and criteria in particular for land use and land-use change due to biomass cultivation and harvesting and indirect impacts due to resource competition.

  15. Motion direction estimation based on active RFID with changing environment

    Science.gov (United States)

    Jie, Wu; Minghua, Zhu; Wei, He

    2018-05-01

    The gate system is used to estimate the direction of RFID tags carriers when they are going through the gate. Normally, it is difficult to achieve and keep a high accuracy in estimating motion direction of RFID tags because the received signal strength of tag changes sharply according to the changing electromagnetic environment. In this paper, a method of motion direction estimation for RFID tags is presented. To improve estimation accuracy, the machine leaning algorithm is used to get the fitting function of the received data by readers which are deployed inside and outside gate respectively. Then the fitted data are sampled to get the standard vector. We compare the stand vector with template vectors to get the motion direction estimation result. Then the corresponding template vector is updated according to the surrounding environment. We conducted the simulation and implement of the proposed method and the result shows that the proposed method in this work can improve and keep a high accuracy under the condition of the constantly changing environment.

  16. Stress before extinction learning enhances and generalizes extinction memory in a predictive learning task.

    Science.gov (United States)

    Meir Drexler, Shira; Hamacher-Dang, Tanja C; Wolf, Oliver T

    2017-05-01

    In extinction learning, the individual learns that a previously acquired association (e.g. between a threat and its predictor) is no longer valid. This learning is the principle underlying many cognitive-behavioral psychotherapeutic treatments, e.g. 'exposure therapy'. However, extinction is often highly-context dependent, leading to renewal (relapse of extinguished conditioned response following context change). We have previously shown that post-extinction stress leads to a more context-dependent extinction memory in a predictive learning task. Yet as stress prior to learning can impair the integration of contextual cues, here we aim to create a more generalized extinction memory by inducing stress prior to extinction. Forty-nine men and women learned the associations between stimuli and outcomes in a predictive learning task (day 1), extinguished them shortly after an exposure to a stress/control condition (day 2), and were tested for renewal (day 3). No group differences were seen in acquisition and extinction learning, and a renewal effect was present in both groups. However, the groups differed in the strength and context-dependency of the extinction memory. Compared to the control group, the stress group showed an overall reduced recovery of responding to the extinguished stimuli, in particular in the acquisition context. These results, together with our previous findings, demonstrate that the effects of stress exposure on extinction memory depend on its timing. While post-extinction stress makes the memory more context-bound, pre-extinction stress strengthens its consolidation for the acquisition context as well, making it potentially more resistant to relapse. These results have implications for the use of glucocorticoids as extinction-enhancers in exposure therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. End Ordovician extinctions

    DEFF Research Database (Denmark)

    Harper, David A. T.; Hammarlund, Emma; Rasmussen, Christian M. Ø.

    2014-01-01

    -global anoxia associated with a marked transgression during the Late Hirnantian. Most recently, however, new drivers for the extinctions have been proposed, including widespread euxinia together with habitat destruction caused by plate tectonic movements, suggesting that the end Ordovician mass extinctions were...

  18. A case study: Integrated work environment and organizational change

    Energy Technology Data Exchange (ETDEWEB)

    Heubach, J.G.; Montgomery, J.C.; Weimer, W.C. [Pacific Northwest Lab., Richland, WA (United States); Heerwagen, J.H. [Battelle Seattle Research Center, WA (United States)

    1995-02-01

    The failure to integrate environmental and organizational interventions may help explain the lack of success of many change efforts. The high rate of failure for change efforts (50% to 90% failure rates) has been noted by many writers. While specific causes of failure are diverse, a common theme has been failure to consider the organization as a system. That is, either significant aspects of the organization were ignored during the intervention or potential impacts of changes on the elements were overlooked or underestimated. Our own training, technical literature, and professional culture lead us to limited understandings of complex organizations. Change agents must consider all relevant components of organizational performance if interventions are to be meaningful and successful. This study demonstrated the value of an integrated organizational intervention involving redesign of the physical environment, introduction of a new information system, work process improvement, and extended organizational development intervention. The outcomes were extremely positive. The cost of improvement efforts was found to be recaptured within a short time, easily justifying the expenditures. One conclusion from the study is that integrated interventions are very powerful. Integrating improvement of the physical environment with organizational development and technological innovation greatly enhances the likelihood of achieving a successful intervention.

  19. Extinction of NGC 7027

    International Nuclear Information System (INIS)

    Seaton, M.J.

    1979-01-01

    Emission intensities of recombination lines in hydrogenic spectra are known accurately relative to intensities in the free-free radio continuum. For NGC 7027 intensities have been measured for the radio continuum and for H I and He II lines in the wavelength range from lambda = 2.17 μm to lambda = 1640 A: comparison with the calculated emission intensities gives the extinction. Determinations of the standard interstellar extinction function are critically discussed. The extinction deduced for the total radiation from NGC 7027 has a dependence on wavelength for 6563 A >= lambda >= 1640 A which is in excellent agreement with the adopted standard results, but there are some anomalies for longer wavelengths and for the ratio of total to selective extinction. These can be explained using a model which allows for a local contribution to the extinction which is variable over the surface of the nebula. (author)

  20. Interstellar extinction correlations

    International Nuclear Information System (INIS)

    Jones, A.P.; Williams, D.A.; Duley, W.W.

    1987-01-01

    A recently proposed model for interstellar grains in which the extinction arises from small silicate cores with mantles of hydrogenated amorphous carbon (HAC or α-C:H), and large, but thinly coated, silicate grains can successfully explain many of the observed properties of interstellar dust. The small silicate cores give rise to the 2200 A extinction feature. The extinction in the visual is produced by the large silicates and the HAC mantles on the small cores, whilst the far UV extinction arises in the HAC mantles with a small contribution form the silicate grains. The grain model requires that the silicate material is the more resilient component and that variations in the observed extinction from region to region are due to the nature and depletion of the carbon in the HAC mantles. (author)

  1. Experience with dynamic reinforcement rates decreases resistance to extinction.

    Science.gov (United States)

    Craig, Andrew R; Shahan, Timothy A

    2016-03-01

    The ability of organisms to detect reinforcer-rate changes in choice preparations is positively related to two factors: the magnitude of the change in rate and the frequency with which rates change. Gallistel (2012) suggested similar rate-detection processes are responsible for decreases in responding during operant extinction. Although effects of magnitude of change in reinforcer rate on resistance to extinction are well known (e.g., the partial-reinforcement-extinction effect), effects of frequency of changes in rate prior to extinction are unknown. Thus, the present experiments examined whether frequency of changes in baseline reinforcer rates impacts resistance to extinction. Pigeons pecked keys for variable-interval food under conditions where reinforcer rates were stable and where they changed within and between sessions. Overall reinforcer rates between conditions were controlled. In Experiment 1, resistance to extinction was lower following exposure to dynamic reinforcement schedules than to static schedules. Experiment 2 showed that resistance to presession feeding, a disruptor that should not involve change-detection processes, was unaffected by baseline-schedule dynamics. These findings are consistent with the suggestion that change detection contributes to extinction. We discuss implications of change-detection processes for extinction of simple and discriminated operant behavior and relate these processes to the behavioral-momentum based approach to understanding extinction. © 2016 Society for the Experimental Analysis of Behavior.

  2. Vulnerability of the paper Nautilus (Argonauta nodosa) shell to a climate-change ocean: potential for extinction by dissolution.

    Science.gov (United States)

    Wolfe, Kennedy; Smith, Abigail M; Trimby, Patrick; Byrne, Maria

    2012-10-01

    Shell calcification in argonauts is unique. Only females of these cephalopods construct the paper nautilus shell, which is used as a brood chamber for developing embryos in the pelagic realm. As one of the thinnest (225 μm) known adult mollusc shells, and lacking an outer protective periostracum-like cover, this shell may be susceptible to dissolution as the ocean warms and decreases in pH. Vulnerability of the A. nodosa shell was investigated through immersion of shell fragments in multifactorial experiments of control (19 °C/pH 8.1; pCO(2) 419; Ω(Ca) = 4.23) and near-future conditions (24 °C/pH 7.8-7.6; pCO(2) 932-1525; Ω(Ca) = 2.72-1.55) for 14 days. More extreme pH treatments (pH 7.4-7.2; pCO(2) 2454-3882; Ω(Ca) = 1.20-0.67) were used to assess tipping points in shell dissolution. X-ray diffractometry revealed no change in mineralogy between untreated and treated shells. Reduced shell weight due to dissolution was evident in shells incubated at pH 7.8 (projected for 2070) after 14 days at control temperature, with increased dissolution in warmer and lower pH treatments. The greatest dissolution was recorded at 24 °C (projected for local waters by 2100) compared to control temperature across all low-pH treatments. Scanning electron microscopy revealed dissolution and etching of shell mineral in experimental treatments. In the absence of compensatory mineralization, the uncovered female brood chamber will be susceptible to dissolution as ocean pH decreases. Since the shell was a crucial adaptation for the evolution of the argonauts' holopelagic existence, persistence of A. nodosa may be compromised by shell dissolution in an ocean-change world.

  3. Leading change to create a healthy and satisfying work environment.

    Science.gov (United States)

    Sanders, Carolyn L; Krugman, Mary; Schloffman, Danielle H

    2013-01-01

    Nurse executives must take a leadership role in creating a healthy work environment for nurses and all disciplines. Engaging in partnerships and empowering clinical nurses to construct the solutions to barriers that may stand in the way of the goal of a satisfied and healthy workforce are important strategies toward success. This publication outlines many projects a 3-time Magnet-designated academic hospital has implemented, working with our shared leadership councils, to meet the standards for a healthy work environment. These initiatives, from the unit to the hospital level, included standardizing a culture change of uninterrupted meal breaks, the creation of intensive care unit Zen rooms, strategies to better manage increased patient volumes, best practices for facility design, enhancing physician-nurse relations, and a hospital wellness program. Data were benchmarked against national nurse and employee surveys to compare progress and report outcomes. Two important nursing organization structures that have contributed to the success of a healthy and satisfied nursing work environment include UEXCEL, a longstanding clinical nurse professional practice program, and the hospital's 11-year participation in the University HealthSystem Consortium/American Association of Colleges of Nursing National Post-Baccalaureate Nurse Residency Program. A highly engaged, well-educated, and committed nursing workforce, nurtured by a strong leadership team, has created a positive work environment characterized by low turnover and high retention.

  4. Change in the family food environment is associated with positive dietary change in children

    Directory of Open Access Journals (Sweden)

    Hendrie Gilly

    2013-01-01

    Full Text Available Abstract Background The family food environment is an important influence in the development of children’s dietary habits. Research suggests that influences of current dietary behaviour and behaviour change may differ. The aims of this paper were to: (1 investigate the association between the food environment at baseline and change in children’s saturated fat intake; and (2 to explore whether a change in the food environment was associated with a change in children’s saturated fat intake. Method Secondary analysis of a 12 week cluster randomised controlled trial in 133 4-13 year old children. Families were randomly allocated to parental education regarding changing to reduced-fat dairy foods or a comparison non-dietary behaviour. The interventions were family focused. Parents received education from a dietitian in 3x30minute sessions to facilitate behaviour change. Parents completed a comprehensive questionnaire capturing three domains of the food environment – Parent knowledge and attitudes; shaping practices; and behaviours and role modelling. Children’s dietary intake was assessed via multiple 24-hour recalls at baseline and week 12. Changes in the family food environment and primary outcome (saturated fat were calculated. Hierarchical linear regression models were performed to explore the association between baseline and change in food environment constructs and change in saturated fat intake. Standardised Beta are presented (p Results After adjustments for child and family demographics, higher levels of perceived food availability (β=-0.2 at baseline was associated with greater reduction in saturated fat intake, where as higher perceived responsibility (β=0.2, restriction (β=0.3 and pressure to eat (β=0.3 were associated with lesser change in saturated fat. An increase in nutrition knowledge (β=-0.2, perceived responsibility (β=-0.3 and restriction (β=-0.3 from baseline to week 12 were associated with greater reduction in

  5. Cropping Systems and Climate Change in Humid Subtropical Environments

    Directory of Open Access Journals (Sweden)

    Ixchel M. Hernandez-Ochoa

    2018-02-01

    Full Text Available In the future, climate change will challenge food security by threatening crop production. Humid subtropical regions play an important role in global food security, with crop rotations often including wheat (winter crop and soybean and maize (summer crops. Over the last 30 years, the humid subtropics in the Northern Hemisphere have experienced a stronger warming trend than in the Southern Hemisphere, and the trend is projected to continue throughout the mid- and end of century. Past rainfall trends range, from increases up to 4% per decade in Southeast China to −3% decadal decline in East Australia; a similar trend is projected in the future. Climate change impact studies suggest that by the middle and end of the century, wheat yields may not change, or they will increase up to 17%. Soybean yields will increase between 3% and 41%, while maize yields will increase by 30% or decline by −40%. These wide-ranging climate change impacts are partly due to the region-specific projections, but also due to different global climate models, climate change scenarios, single-model uncertainties, and cropping system assumptions, making it difficult to make conclusions from these impact studies and develop adaptation strategies. Additionally, most of the crop models used in these studies do not include major common stresses in this environment, such as heat, frost, excess water, pests, and diseases. Standard protocols and impact assessments across the humid subtropical regions are needed to understand climate change impacts and prepare for adaptation strategies.

  6. Sustainability of Biomass Utilisation in Changing operational Environment - SUBICHOE

    Energy Technology Data Exchange (ETDEWEB)

    Soimakallio, S.; Hongisto, M.; Koponen, K. (VTT Technical Research Centre of Finland, Espoo (Finland)), e-mail: sampo.soimakallio@vtt.fi (and others)

    2011-11-15

    Sustainability is a multi-faceted and challenging target, but at the same time a crucial issue to assess when setting policies and targets for the future. The main objective of the SUBICHOE project is to assist public administration and companies in strategic decision- making in the most sustainable use of biomass, by taking into account the changing operational environment. The project aimed to assess how the sustainability criteria, in particular those set by the EC, ensure the sustainability of biofuels from short and long term perspectives. The project is carried out jointly by VTT Technical Research Centre of Finland, Finnish Environment Institute SYKE, MTT Agrifood Research Finland, Finnish Forest Research Institute (Metla) and The Government Institute for Economic Research (VATT). The work plan of the project is divided into four Work Packages. In this article, a summary of main findings of the project is presented. (orig.)

  7. Environment Changes Genetic Effects on Respiratory Conditions and Allergic Phenotypes

    DEFF Research Database (Denmark)

    Song, Yong; Schwager, Michelle J; Backer, Vibeke

    2017-01-01

    The prevalence of asthma and allergic diseases is disproportionately distributed among different populations, with an increasing trend observed in Western countries. Here we investigated how the environment affected genotype-phenotype association in a genetically homogeneous, but geographically...... separated population. We evaluated 18 single nucleotide polymorphisms (SNPs) corresponding to 8 genes (ADAM33, ALOX5, LT-α, LTC4S, NOS1, ORMDL3, TBXA2R and TNF-α), the lung function and five respiratory/allergic conditions (ever asthma, bronchitis, rhinitis, dermatitis and atopy) in two populations of Inuit......-phenotype associations relating to bronchitis and allergy susceptibility are dependent on the environment and that environmental factors/lifestyles modify genetic predisposition and change the genetic effects on diseases....

  8. Climate change, living environment and ways of life

    International Nuclear Information System (INIS)

    Jaervelae, M.; Wilenius, M.

    1994-01-01

    The research project 'Climate Change, Living Environment and Way of Life' is focused on the social concepts of risks and of proposed policies related to global environmental problems as seen by representatives of various social groups. Drawing on the social-scientific methodology and applying its concept apparatus, the research project focuses on two central problems in the field of contemporary environmental research. Firstly, with the way in which environmental problems influence people's values and attitudes. Secondly, with the question of how people seek to act and to show solidarity towards new generations by means of environmental policies or by protecting nature within the framework of their private ways of life

  9. U.S. NGL supply in the changing environment

    International Nuclear Information System (INIS)

    Billings, F.

    1996-01-01

    This paper discusses the outlook for domestic NGL supply, demand for natural gas liquids in the US, and review a couple of key drivers of natural gas liquids demand; ethylene production and capacity and Gross Domestic Product (GDP) growth. The author reviews historical US NGL production in key supply areas over the past five years, as well as look forward through the year 2000. Then briefly touch on the recent activity, specifically the types of consolidations, changing the environment in the gas gathering, gas processing and natural gas liquids industry and its impact on future NGL markets

  10. Is IR going extinct?

    Science.gov (United States)

    Mitchell, Audra

    2016-01-01

    A global extinction crisis may threaten the survival of most existing life forms. Influential discourses of ‘existential risk’ suggest that human extinction is a real possibility, while several decades of evidence from conservation biology suggests that the Earth may be entering a ‘sixth mass extinction event’. These conditions threaten the possibilities of survival and security that are central to most branches of International Relations. However, this discipline lacks a framework for addressing (mass) extinction. From notions of ‘nuclear winter’ and ‘omnicide’ to contemporary discourses on catastrophe, International Relations thinking has treated extinction as a superlative of death. This is a profound category mistake: extinction needs to be understood not in the ontic terms of life and death, but rather in the ontological context of be(com)ing and negation. Drawing on the work of theorists of the ‘inhuman’ such as Quentin Meillassoux, Claire Colebrook, Ray Brassier, Jean-Francois Lyotard and Nigel Clark, this article provides a pathway for thinking beyond existing horizons of survival and imagines a profound transformation of International Relations. Specifically, it outlines a mode of cosmopolitics that responds to the element of the inhuman and the forces of extinction. Rather than capitulating to narratives of tragedy, this cosmopolitics would make it possible to think beyond the restrictions of existing norms of ‘humanity’ to embrace an ethics of gratitude and to welcome the possibility of new worlds, even in the face of finitude.

  11. Academic Training: Climate change and challenges for the environment

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 14, 15, 16 November from 11:00 to 12:00 - TH Auditorium, bldg. 4 Climate change and challenges for the environment by C. Schlüchter / Institut für Geologie, Univ. Bern, CH Climate change as seen by a geologist Glaciers are an integrated part of the high altitudes and the high latitudes of our planet. They are sensitive to temperature and moisture changes and adjust their mass balances accordingly. By doing so they interact with their substratum, the geological basement and they produce characteristic imprints of their presence, their variability and their disappearance. In glacial geology and paleoglaciology such imprints of former glaciers are carefully recorded, mapped and, hopefully, dated in order to obtain amplitude and periodicity records of their changes - as forced by changing climate, as we believe. In the upcoming lectures three aspects will be discussed: the last glaciation in the Swiss Alps. A reconstruction is shown based on fieldwor...

  12. Structural changes of marine communities over the Permian-Triassic transition: Ecologically assessing the end-Permian mass extinction and its aftermath

    Science.gov (United States)

    Chen, Zhong-Qiang; Tong, Jinnan; Liao, Zhuo-Ting; Chen, Jing

    2010-08-01

    The Permian/Triassic (P/Tr) transition is ecologically assessed based on examining 23 shelly communities from five shallow platform, ramp and shelf basin facies Permian-Triassic boundary (PTB) sections in South China. The shelly communities have undergone two major collapses coinciding with the two episodes of the end-Permian mass extinction. The first P/Tr extinction event devastated shelly communities in all types of settings to some extent. The basin communities have been more severely impacted than both platform and ramp communities. The survival faunas have rebounded more rapidly in shallow niches than in relatively deep habitats. The second P/Tr crisis destroyed the survival communities in shallow setting and had little impact on the basin communities in terms of community structures. The early Griesbachian communities are overall low-diversity and high-dominance. The governorship switch from brachiopods to bivalves in marine communities has been facilitated by two pulses of the end-Permian mass extinction and the whole takeover process took about 200 ka across the P/Tr boundary. Bivalve ecologic takeover initially occurred immediately after the first P/Tr extinction in shallow water habitats and was eventually completed in all niches after the second P/Tr event. Some post-extinction communities have the irregular rarefaction curves due to the unusual community structures rather than sampling intensities.

  13. Variation of the extinction law in the Trifid nebula

    OpenAIRE

    Cambrésy, L.; Rho, J.; Marshall, D. J.; Reach, W. T.

    2011-01-01

    Context. In the past few years, the extinction law has been measured in the infrared wavelengths for various molecular clouds and different laws have been obtained. Aims. In this paper we seek variations of the extinction law within the Trifid nebula region. Such variations would demonstrate local dust evolution linked to variation of the environment parameters such as the density or the interstellar radiation field. Methods. The extinction values, A_λ/A_v, are obtained using the 2MASS, UKIDS...

  14. Temporal Dynamics of Recovery from Extinction Shortly after Extinction Acquisition

    Science.gov (United States)

    Archbold, Georgina E.; Dobbek, Nick; Nader, Karim

    2013-01-01

    Evidence suggests that extinction is new learning. Memory acquisition involves both short-term memory (STM) and long-term memory (LTM) components; however, few studies have examined early phases of extinction retention. Retention of auditory fear extinction was examined at various time points. Shortly (1-4 h) after extinction acquisition…

  15. Designing for Change: Interoperability in a scaling and adapting environment

    Science.gov (United States)

    Yarmey, L.

    2015-12-01

    The Earth Science cyberinfrastructure landscape is constantly changing. Technologies advance and technical implementations are refined or replaced. Data types, volumes, packaging, and use cases evolve. Scientific requirements emerge and mature. Standards shift while systems scale and adapt. In this complex and dynamic environment, interoperability remains a critical component of successful cyberinfrastructure. Through the resource- and priority-driven iterations on systems, interfaces, and content, questions fundamental to stable and useful Earth Science cyberinfrastructure arise. For instance, how are sociotechnical changes planned, tracked, and communicated? How should operational stability balance against 'new and shiny'? How can ongoing maintenance and mitigation of technical debt be managed in an often short-term resource environment? The Arctic Data Explorer is a metadata brokering application developed to enable discovery of international, interdisciplinary Arctic data across distributed repositories. Completely dependent on interoperable third party systems, the Arctic Data Explorer publicly launched in 2013 with an original 3000+ data records from four Arctic repositories. Since then the search has scaled to 25,000+ data records from thirteen repositories at the time of writing. In the final months of original project funding, priorities shift to lean operations with a strategic eye on the future. Here we present lessons learned from four years of Arctic Data Explorer design, development, communication, and maintenance work along with remaining questions and potential directions.

  16. To predict the niche, model colonization and extinction

    Science.gov (United States)

    Yackulic, Charles B.; Nichols, James D.; Reid, Janice; Der, Ricky

    2015-01-01

    Ecologists frequently try to predict the future geographic distributions of species. Most studies assume that the current distribution of a species reflects its environmental requirements (i.e., the species' niche). However, the current distributions of many species are unlikely to be at equilibrium with the current distribution of environmental conditions, both because of ongoing invasions and because the distribution of suitable environmental conditions is always changing. This mismatch between the equilibrium assumptions inherent in many analyses and the disequilibrium conditions in the real world leads to inaccurate predictions of species' geographic distributions and suggests the need for theory and analytical tools that avoid equilibrium assumptions. Here, we develop a general theory of environmental associations during periods of transient dynamics. We show that time-invariant relationships between environmental conditions and rates of local colonization and extinction can produce substantial temporal variation in occupancy–environment relationships. We then estimate occupancy–environment relationships during three avian invasions. Changes in occupancy–environment relationships over time differ among species but are predicted by dynamic occupancy models. Since estimates of the occupancy–environment relationships themselves are frequently poor predictors of future occupancy patterns, research should increasingly focus on characterizing how rates of local colonization and extinction vary with environmental conditions.

  17. Changes seen in the environment report from Uusimaa Regional Environment Centre

    International Nuclear Information System (INIS)

    Enckell, E.; Airola, H.; Tornivaara-Ruikka, R.; Villa, L.; Salasto, R.

    2002-05-01

    This publication describes the environmental changes and the influencing factors occurring within the administrative regions of the Uusimaa Regional Environment Centre. The quality of the environment can be judged as satisfying in regards to both the mental and physical health of humans. Areas have a steady trend of a relatively high growth in population density, while the efficiency of land use in new settlements is low. Traffic and the travel distances are on the rise. A considerable part of the population lives in areas where the noise standards are violated, despite control measures. Waste management, water distribution and sewage networks are under continuous development. In regards to the nature, the situation in some parts is of great concern. The manifold of the nature, cultural landscapes and culturally valuable buildings and sites are threatened. The living space of flora and fauna is continuing to decrease and change. The risks caused by human activities in groundwater areas are increasing. For these reasons the implementation of protection programs is important. Emissions from point sources to the water and air have significantly decreased. Yet, the impacts of air quality deprivation can still be seen in some cities and in the vicinity of some industrial sites. The eutrophication have essentially changed the ecology and fishstocks; however, the water quality has improved in many places. Regarding the above issues, as well as some other topics, included in the report are 16 theme maps 66 pictures. However, the report states that the monitoring and reporting of the environmental quality should be improved. (orig.)

  18. Extinctions. Paleontological baselines for evaluating extinction risk in the modern oceans.

    Science.gov (United States)

    Finnegan, Seth; Anderson, Sean C; Harnik, Paul G; Simpson, Carl; Tittensor, Derek P; Byrnes, Jarrett E; Finkel, Zoe V; Lindberg, David R; Liow, Lee Hsiang; Lockwood, Rowan; Lotze, Heike K; McClain, Craig R; McGuire, Jenny L; O'Dea, Aaron; Pandolfi, John M

    2015-05-01

    Marine taxa are threatened by anthropogenic impacts, but knowledge of their extinction vulnerabilities is limited. The fossil record provides rich information on past extinctions that can help predict biotic responses. We show that over 23 million years, taxonomic membership and geographic range size consistently explain a large proportion of extinction risk variation in six major taxonomic groups. We assess intrinsic risk-extinction risk predicted by paleontologically calibrated models-for modern genera in these groups. Mapping the geographic distribution of these genera identifies coastal biogeographic provinces where fauna with high intrinsic risk are strongly affected by human activity or climate change. Such regions are disproportionately in the tropics, raising the possibility that these ecosystems may be particularly vulnerable to future extinctions. Intrinsic risk provides a prehuman baseline for considering current threats to marine biodiversity. Copyright © 2015, American Association for the Advancement of Science.

  19. Breeding Young as a Survival Strategy during Earth’s Greatest Mass Extinction

    Science.gov (United States)

    Botha-Brink, Jennifer; Codron, Daryl; Huttenlocker, Adam K.; Angielczyk, Kenneth D.; Ruta, Marcello

    2016-04-01

    Studies of the effects of mass extinctions on ancient ecosystems have focused on changes in taxic diversity, morphological disparity, abundance, behaviour and resource availability as key determinants of group survival. Crucially, the contribution of life history traits to survival during terrestrial mass extinctions has not been investigated, despite the critical role of such traits for population viability. We use bone microstructure and body size data to investigate the palaeoecological implications of changes in life history strategies in the therapsid forerunners of mammals before and after the Permo-Triassic Mass Extinction (PTME), the most catastrophic crisis in Phanerozoic history. Our results are consistent with truncated development, shortened life expectancies, elevated mortality rates and higher extinction risks amongst post-extinction species. Various simulations of ecological dynamics indicate that an earlier onset of reproduction leading to shortened generation times could explain the persistence of therapsids in the unpredictable, resource-limited Early Triassic environments, and help explain observed body size distributions of some disaster taxa (e.g., Lystrosaurus). Our study accounts for differential survival in mammal ancestors after the PTME and provides a methodological framework for quantifying survival strategies in other vertebrates during major biotic crises.

  20. Are marine and nonmarine extinctions correlated?

    Science.gov (United States)

    Rampino, Michael R.

    Recent papers in Eos have debated the possible relationships between marine mass extinctions, comet showers, and volcanism [Alvarez, 1986; Officer and Grieve, 1986], and ail three might be linked [Rampino, 1987]. Moreover, as Officer and Grieve [ 1986] point out, various other causes have been suggested for given extinction events, including changes in climate, ocean circulation, and sea level fluctuations, possibly related to plate tectonics and continental positions. Also under debate is the issue of whether mass extinctions were gradual, stepped, or geologically sudden events (see, for example, Hut et al. [1987]). A missing ingredient thus far in these debates has been the record of faunal diversity of nonmarine animals. Does this show any agreement with the marine extinction record?

  1. Extinction vulnerability of coral reef fishes.

    Science.gov (United States)

    Graham, Nicholas A J; Chabanet, Pascale; Evans, Richard D; Jennings, Simon; Letourneur, Yves; Aaron Macneil, M; McClanahan, Tim R; Ohman, Marcus C; Polunin, Nicholas V C; Wilson, Shaun K

    2011-04-01

    With rapidly increasing rates of contemporary extinction, predicting extinction vulnerability and identifying how multiple stressors drive non-random species loss have become key challenges in ecology. These assessments are crucial for avoiding the loss of key functional groups that sustain ecosystem processes and services. We developed a novel predictive framework of species extinction vulnerability and applied it to coral reef fishes. Although relatively few coral reef fishes are at risk of global extinction from climate disturbances, a negative convex relationship between fish species locally vulnerable to climate change vs. fisheries exploitation indicates that the entire community is vulnerable on the many reefs where both stressors co-occur. Fishes involved in maintaining key ecosystem functions are more at risk from fishing than climate disturbances. This finding is encouraging as local and regional commitment to fisheries management action can maintain reef ecosystem functions pending progress towards the more complex global problem of stabilizing the climate. © 2011 Blackwell Publishing Ltd/CNRS.

  2. Extinction of laminar partially premixed flames

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Suresh K. [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor Street, Room 2039, MC-251, Chicago, IL 60607-7022 (United States)

    2009-12-15

    Flame extinction represents one of the classical phenomena in combustion science. It is important to a variety of combustion systems in transportation and power generation applications. Flame extinguishment studies are also motivated from the consideration of fire safety and suppression. Such studies have generally considered non-premixed and premixed flames, although fires can often originate in a partially premixed mode, i.e., fuel and oxidizer are partially premixed as they are transported to the reaction zone. Several recent investigations have considered this scenario and focused on the extinction of partially premixed flames (PPFs). Such flames have been described as hybrid flames possessing characteristics of both premixed and non-premixed flames. This paper provides a review of studies dealing with the extinction of PPFs, which represent a broad family of flames, including double, triple (tribrachial), and edge flames. Theoretical, numerical and experimental studies dealing with the extinction of such flames in coflow and counterflow configurations are discussed. Since these flames contain both premixed and non-premixed burning zones, a brief review of the dilution-induced extinction of premixed and non-premixed flames is also provided. For the coflow configuration, processes associated with flame liftoff and blowout are described. Since lifted non-premixed jet flames often contain a partially premixed or an edge-flame structure prior to blowout, the review also considers such flames. While the perspective of this review is broad focusing on the fundamental aspects of flame extinction and blowout, results mostly consider flame extinction caused by the addition of a flame suppressant, with relevance to fire suppression on earth and in space environment. With respect to the latter, the effect of gravity on the extinction of PPFs is discussed. Future research needs are identified. (author)

  3. Presidential address: distinction or extinction.

    Science.gov (United States)

    Pressman, Barry D

    2008-10-01

    Despite its continuing scientific successes in imaging, radiology as a specialty is faced with a very difficult and competitive environment. Nonradiologists are more and more interested in vertically integrating imaging into their practices, while teleradiology and picture archiving and communication systems are resulting in the greater isolation of radiologists. Commoditization is a realistic and devastating threat to the survival and professionalism of the specialty. To remain viable as a specialty, radiologists must elevate their practice by subspecializing, becoming more involved with clinical care, and actively interacting with patients and referring clinicians. Distinction will prevent extinction.

  4. Individuals’ changes in their lifestyle to build a sustainable environment

    Directory of Open Access Journals (Sweden)

    Matheus Lacerda Viana

    2016-12-01

    Full Text Available The unsustainable use of natural resources is not a current issue and it began since the Agricultural Revolution, which characterizes the change in the relationship between man and nature. The first major environmental impacts emerged and as a result of this new way of life that went from nomadism to sedentary lifestyles, there was an increase of human productive capacity and the emergence of other crafts that were not directly related to food production. This paper provides a complete definition of the key concepts, suggest a few alternatives which people can apply on their daily lives, and relate them to the framework that rules sustainability. The main arguments for this work are that citizens in the developed world can reduce the pressure being placed on the state of the environment and contribute to sustainable development by saving energy and water, reducing waste, and choosing a transportation which emits less pollutants.

  5. Research progress on expansive soil cracks under changing environment.

    Science.gov (United States)

    Shi, Bei-xiao; Zheng, Cheng-feng; Wu, Jin-kun

    2014-01-01

    Engineering problems shunned previously rise to the surface gradually with the activities of reforming the natural world in depth, the problem of expansive soil crack under the changing environment becoming a control factor of expansive soil slope stability. The problem of expansive soil crack has gradually become a research hotspot, elaborates the occurrence and development of cracks from the basic properties of expansive soil, and points out the role of controlling the crack of expansive soil strength. We summarize the existing research methods and results of expansive soil crack characteristics. Improving crack measurement and calculation method and researching the crack depth measurement, statistical analysis method, crack depth and surface feature relationship will be the future direction.

  6. Academic Training: Climate change and challenges for the environment / POSTPONED!!!

    CERN Multimedia

    Françoise benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 20, 21, 22 June 20, 21, 22 June, from 11:00 to 12:00 - Main Auditorium, bldg. 500 Climate change and challenges for the environment C. SCHLUECHTER / Univ. Bern, CH The seminar is postponed. ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an 'application for training' form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt.

  7. Sustainability of biomass utilisation in changing operational environment - SUBICHOE

    Energy Technology Data Exchange (ETDEWEB)

    Soimakallio, S.; Hongisto, M.; Koponen, K.; Sokka, L. (VTT Technical Research Centre of Finland, Espoo (Finland)), Email: sampo.soimakallio@vtt.fi; Antikainen, R.; Manninen, K. (Finnish Environment Inst. SYKE, Helsinki (Finland)); Thun, R.; Sinkko, T. (MTT Agrifood Research Finland, Jokioinen (Finland)); Pasanen, K. (Finnish Forest Research Inst., Joensuu (Finland))

    2010-10-15

    Sustaibability is a multi-faceted and challenging target, but at the same time a crucial issue to assess when setting policies and targets for the future. The main objective of the SUBICHOE project is to assist in strategic decision- making of public administration and companies, as regards the most sustainable use of biomass, by taking into account the changing operational environment. In the project the sustainability of biofuels and the criteria, in particular those set by the EC, for ensuring that set requirements can and will be fulfilled are being assessed from short and long term perspectives. The project is carried out jointly by VTT Technical Research Centre of Finland, Finnish Environment Institute SYKE, MTT Agrifood Research Finland, Finnish Forest Research Institute (Metla) and The Government Institute for Economic Research (VATT). The project started in June 2009 and it is scheduled to be finalised in June 2011. The work plan of the project is divided into four Work Packages. In this article, a summary of a critical view on the requirements and challenges related to the implementation of the RES Directive is also provided based on the main findings of the WP1. (orig.)

  8. Late Quaternary Megafaunal Extinctions in Northern Eurasia: Latest Results

    Science.gov (United States)

    Stuart, Anthony

    2010-05-01

    Anthony J. Stuart1 & Adrian M. Lister2 1 Biological and Biomedical Sciences, Durham University, South Road, Durham DH1 3LE, UK. Email: tony.s@megafauna.org.uk 2 Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK. Email: a.lister@nhm.ac.uk. The global extinction of many spectacular species of megafauna (large terrestrial mammals, together with a few large reptiles and birds) within the last c. 50,000 years (Late Quaternary) has been attributed on the one hand to ‘overkill' by human hunters and on the other to environmental change. However, in spite of more than half a century of active interest and research the issue remains unresolved, largely because there are insufficient dated records of megafaunal species for most parts of the world. Northern Eurasia is an especially fruitful region in which to research megafaunal extinctions as it has a wealth of megafaunal material and crucially most extinctions occurred well within the range of radiocarbon dating. Our approach, in a series of projects over the last decade funded by the UK Natural Environment Research Council (NERC), involves amassing radiocarbon dates made directly on megafaunal material from across the entire region: a) by submitting a substantial number of samples (so far c. 500 dates) for AMS dating at Oxford (ORAU); b) obtaining AMS dates from colleagues working on aDNA projects; and c) carefully screening (‘auditing') dates from the literature. The dates (calibrated using OxCal) are plotted as time-sliced maps and as chronological/geographical charts. In our previous work we targeted a range of extinct species from Northern Eurasia: woolly mammoth, woolly rhinoceros, giant deer, cave bear (in collaboration with Martina Pacher), cave lion, and spotted hyaena (which survives today only in Sub-Saharan Africa). By this means we have established a reliable chronology for these extinctions which we are able to compare with the climatic, vegetational and

  9. A window of vulnerability: impaired fear extinction in adolescence.

    Science.gov (United States)

    Baker, Kathryn D; Den, Miriam L; Graham, Bronwyn M; Richardson, Rick

    2014-09-01

    There have been significant advances made towards understanding the processes mediating extinction of learned fear. However, despite being of clear theoretical and clinical significance, very few studies have examined fear extinction in adolescence, which is often described as a developmental window of vulnerability to psychological disorders. This paper reviews the relatively small body of research examining fear extinction in adolescence. A prominent finding of this work is that adolescents, both humans and rodents, exhibit a marked impairment in extinction relative to both younger (e.g., juvenile) and older (e.g., adult) groups. We then review some potential mechanisms that could produce the striking extinction deficit observed in adolescence. For example, one neurobiological candidate mechanism for impaired extinction in adolescence involves changes in the functional connectivity within the fear extinction circuit, particularly between prefrontal cortical regions and the amygdala. In addition, we review research on emotion regulation and attention processes that suggests that developmental changes in attention bias to threatening cues may be a cognitive mechanism that mediates age-related differences in extinction learning. We also examine how a differential reaction to chronic stress in adolescence impacts upon extinction retention during adolescence as well as in later life. Finally, we consider the findings of several studies illustrating promising approaches that overcome the typically-observed extinction impairments in adolescent rodents and that could be translated to human adolescents. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Dental Education Required for the Changing Health Care Environment.

    Science.gov (United States)

    Fontana, Margherita; González-Cabezas, Carlos; de Peralta, Tracy; Johnsen, David C

    2017-08-01

    To be able to meet the demands for care in 2040, dental graduates will need to address challenges resulting from the rapidly changing health care environment with knowledge and sets of skills to build on current standards and adapt to the future. The purposes of this article are to 1) analyze key challenges likely to evolve considerably between now and 2040 that will impact dental education and practice and 2) propose several sets of skills and educational outcomes necessary to address these challenges. The challenges discussed include changes in prevalence of oral diseases, dental practice patterns, materials and technologies, integrated medical-dental care, role of electronic health records, cultural competence, integrated curricula, interprofessional education, specialty-general balance, and web/cloud-based collaborations. To meet these challenges, the dental graduate will need skills such as core knowledge in basic and clinical dentistry, technical proficiency, critical thinking skills for lifelong learning, ethical and professional values, ability to manage a practice, social responsibility, and ability to function in a collegial intra- and interprofessional setting. Beyond the skills of the individual dentist will be the need for leadership in academia and the practice community. Academic and professional leaders will need to engage key constituencies to develop strategic directions and agendas with all parties pointed toward high standards for individual patients and the public at large. This article was written as part of the project "Advancing Dental Education in the 21 st Century."

  11. Modeling adaptation of wetland plants under changing environments

    Science.gov (United States)

    Muneepeerakul, R.; Muneepeerakul, C. P.

    2010-12-01

    An evolutionary-game-theoretic approach is used to study the changes in traits of wetland plants in response to environmental changes, e.g., altered patterns of rainfall and nutrients. Here, a wetland is considered as a complex adaptive system where plants can adapt their strategies and influence one another. The system is subject to stochastic rainfall, which controls the dynamics of water level, soil moisture, and alternation between aerobic and anaerobic conditions in soil. Based on our previous work, a plant unit is characterized by three traits, namely biomass nitrogen content, specific leaf area, and allocation to rhizome. These traits control the basic functions of plants such as assimilation, respiration, and nutrient uptake, while affecting their environment through litter chemistry, root oxygenation, and thus soil microbial dynamics. The outcome of this evolutionary game, i.e., the best-performing plant traits against the backdrop of these interactions and feedbacks, is analyzed and its implications on important roles of wetlands in supporting our sustainability such as carbon sequestration in biosphere, nutrient cycling, and repository of biodiversity are discussed.

  12. AESoP: Astronomical Extinction Spectrophotometer

    Science.gov (United States)

    Linford, Justin; McGraw, J.; Zimmer, P.; Ackermann, M.; Fitch, J.

    2009-01-01

    The Earth's atmosphere is a major obstruction to the precision and accuracy of ground-based photometry. The atmosphere removes light from astronomical objects both by absorption and scattering by constituent molecules, aerosols and clouds. These effects can change significantly over short time periods and over modest angles on the sky. To further understand these effects, the UNM Measurement Astrophysics Group has designed, built and recently deployed the Astronomical Extinction Spectrophotometer (AESoP), a 100mm objective grating spectrometer. By monitoring bright stars in sensibly the same direction as a larger photometric telescope is observing, AESoP will measure the wavelength-dependent extinction due to the Earth's atmosphere from 450nm to 900nm on time scales of approximately one minute. The collocated Astronomical LIDAR for Extinction (ALE) provides a high-precision monochromatic extinction measurement at 527nm. Knowing the extinction at a single wavelength allows us to pin the relative spectra generated by AESoP. These extinction spectra can then be integrated over the bandpass of the photometric telescope system to create real time corrections of observations. We present the design and construction of AESoP along with the preliminary results of our first combined observing campaign. This effort is our first step toward breaking the 1% photometry barrier. This project is funded by AFRL Grant FA9451-04-2-0355

  13. Power plant construction contracting in a changing regulatory environment

    International Nuclear Information System (INIS)

    Person, J.C.

    1993-01-01

    The 1965 blackout in the Northeast provided the wake-up call that spawned in unprecedented program of power plant construction by electric utilities. This building program began in the late 1960s and continued unabated through the 1970s. Beginning in the late 1970s, state regulators began in era of 'prudence' reviews which disallowed as imprudent significant portions of the costs of certain nuclear units being brought on line at the time. This regulatory experience brought about a fundamental change in the way in which utilities evaluated the need for additional capacity. This paper explores construction contracting trends in light of recent developments in the relationship between the electric utility and the state regulator. It is within this context that the utility decides: (1) whether to build, buy, or save; and (2) if the decision is to build, which project planning and administration considerations will maximize the utility's ability to incorporate project costs into the ratebase. In order to put these issues into their proper perspective, this paper first presents a brief overview of the prudence decisions of the past, and the chilling effect of these decisions generally on new project planning. The paper next focuses on the recent changes to the post-construction prudence review model, including the introduction of pre-approval arrangements and rolling prudence reviews. Following that will be a survey of new construction spending decisions in light of these changes. After an analysis of the bases for the prudence disallowances of the past and the application of the lessons learned from these disallowances to contract planning and administration issues of today, the paper will close with a discussion of the relative advantages and disadvantages of the most commonly used contract delivery methods in today's regulatory environment

  14. Dynamics and life histories of northern ungulates in changing environments

    Science.gov (United States)

    Hendrichsen, D. K.

    2011-12-01

    Regional climate and local weather conditions can profoundly influence life history parameters (growth, survival, fecundity) and population dynamics in northern ungulates (Post and Stenseth 1999, Coulson et al. 2001). The influence is both direct, for example through reduced growth or survival (Aanes et al. 2000, Tyler et al. 2008), and indirect, for example through changes in resource distribution, phenology and quality, changes which subsequently influence consumer dynamics (Post et al. 2008). By comparing and contrasting data from three spatially independent populations of ungulates, I discuss how variation in local weather parameters and vegetation growth influence spatial and temporal dynamics through changes in life history parameters and/or behavioural dynamics. The data originate from long term (11-15 years) monitoring data from three populations of ungulates in one subarctic and two high Arctic sites; semi-domesticated reindeer (Rangifer tarandus tarandus) in northern Norway, Svalbard reindeer (R. t. platyrhynchus) on Spitsbergen and muskoxen (Ovibos moschatus) in Northeast Greenland. The results show that juvenile animals can be particularly vulnerable to changes in their environment, and that this is mirrored to different degrees in the spatio-temporal dynamics of the three populations. Adverse weather conditions, acting either directly or mediated through access to and quality of vegetation, experienced by young early in life, or even by their dams during pregnancy, can lead to reduced growth, lower survival and reduced reproductive performance later in life. The influence of current climatic variation, and the predictions of how local weather conditions may change over time, differs between the three sites, resulting in potentially different responses in the three populations. Aanes R, Saether BE and Øritsland NA. 2000. Fluctuations of an introduced population of Svalbard reindeer: the effects of density dependence and climatic variation. Ecography

  15. Flourishing ocean drives the end-Permian marine mass extinction.

    Science.gov (United States)

    Schobben, Martin; Stebbins, Alan; Ghaderi, Abbas; Strauss, Harald; Korn, Dieter; Korte, Christoph

    2015-08-18

    The end-Permian mass extinction, the most severe biotic crisis in the Phanerozoic, was accompanied by climate change and expansion of oceanic anoxic zones. The partitioning of sulfur among different exogenic reservoirs by biological and physical processes was of importance for this biodiversity crisis, but the exact role of bioessential sulfur in the mass extinction is still unclear. Here we show that globally increased production of organic matter affected the seawater sulfate sulfur and oxygen isotope signature that has been recorded in carbonate rock spanning the Permian-Triassic boundary. A bifurcating temporal trend is observed for the strata spanning the marine mass extinction with carbonate-associated sulfate sulfur and oxygen isotope excursions toward decreased and increased values, respectively. By coupling these results to a box model, we show that increased marine productivity and successive enhanced microbial sulfate reduction is the most likely scenario to explain these temporal trends. The new data demonstrate that worldwide expansion of euxinic and anoxic zones are symptoms of increased biological carbon recycling in the marine realm initiated by global warming. The spatial distribution of sulfidic water column conditions in shallow seafloor environments is dictated by the severity and geographic patterns of nutrient fluxes and serves as an adequate model to explain the scale of the marine biodiversity crisis. Our results provide evidence that the major biodiversity crises in Earth's history do not necessarily implicate an ocean stripped of (most) life but rather the demise of certain eukaryotic organisms, leading to a decline in species richness.

  16. Extinction and dust properties in a clumpy medium

    OpenAIRE

    Scicluna, P.; Siebenmorgen, R.

    2015-01-01

    (abridged) The dust content of the universe is primarily explored via its interaction with stellar photons, producing interstellar extinction. However, owing to the physical extension of the observing beam, observations may detect scattered photons, resulting in a change in the observed (or effective) extinction, depending on the spatial distribution of the dust and the resolution of the instrument. We investigate the influence of clumpy dust distributions on effective extinction toward embed...

  17. Towards a sustainable Asia. Environment and climate change

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This series of books are the output of the research project called ''Sustainable Development in Asia (SDA)'', which was initiated by the Association of Academies of Sciences in Asia (AASA). They are comprised of one synthesis report, which entitled ''Towards a Sustainable Asia: Green Transition and Innovation'', and four thematic reports on natural resources, energy, the environment and climate change, and culture from particular perspectives of agriculture. They aim to: (1) investigate common sustainability issues faced by all Asian countries, including population increase, poverty alleviation, pollution control, ecological restoration, as well as regional problems, such as water shortage in West and Central Asia, energy security in Northeast Asia, development model and transformation in East Asia; (2) analyze and summarize of best practices towards sustainable development in Asia; (3) bring forward suggestions and policy options for promoting green transition, system innovation and sustainable development of Asia. With best practice guidelines for a sustainable Asia, this series of reports, for the first time systematically address the common challenges and regional problems in regard to Asia's natural resources use, pollution reduction and climate protection, sustainable energy development, and innovations for environment-friendly and culture-compatible agriculture. They will provide handy and useful information to researchers, government policy makers and the general public who have concerns about Asia's sustainable development. AASA is a scientific and technological organization in Asia, established in 2000, comprising of 26 member academies all over Asia. Its vision is to provide a forum for the discussion of all issues relevant to science and technology development and its application on national level within Asia. (orig.)

  18. Tools for estimating VMT reductions from built environment changes.

    Science.gov (United States)

    2013-06-01

    Built environment characteristics are associated with walking, bicycling, transit use, and vehicle : miles traveled (VMT). Developing built environments supportive of walking, bicycling, and transit use : can help meet state VMT reduction goals. But ...

  19. The Worldviews Network: Transformative Global Change Education in Immersive Environments

    Science.gov (United States)

    Hamilton, H.; Yu, K. C.; Gardiner, N.; McConville, D.; Connolly, R.; "Irving, Lindsay", L. S.

    2011-12-01

    Our modern age is defined by an astounding capacity to generate scientific information. From DNA to dark matter, human ingenuity and technologies create an endless stream of data about ourselves and the world of which we are a part. Yet we largely founder in transforming information into understanding, and understanding into rational action for our society as a whole. Earth and biodiversity scientists are especially frustrated by this impasse because the data they gather often point to a clash between Earth's capacity to sustain life and the decisions that humans make to garner the planet's resources. Immersive virtual environments offer an underexplored link in the translation of scientific data into public understanding, dialogue, and action. The Worldviews Network is a collaboration of scientists, artists, and educators focused on developing best practices for the use of immersive environments for science-based ecological literacy education. A central tenet of the Worldviews Network is that there are multiple ways to know and experience the world, so we are developing scientifically accurate, geographically relevant, and culturally appropriate programming to promote ecological literacy within informal science education programs across the United States. The goal of Worldviews Network is to offer transformative learning experiences, in which participants are guided on a process integrating immersive visual explorations, critical reflection and dialogue, and design-oriented approaches to action - or more simply, seeing, knowing, and doing. Our methods center on live presentations, interactive scientific visualizations, and sustainability dialogues hosted at informal science institutions. Our approach uses datasets from the life, Earth, and space sciences to illuminate the complex conditions that support life on earth and the ways in which ecological systems interact. We are leveraging scientific data from federal agencies, non-governmental organizations, and our

  20. Interstellar dust and extinction

    International Nuclear Information System (INIS)

    Mathis, J.S.

    1990-01-01

    It is noted that the term interstellar dust refers to materials with rather different properties, and that the mean extinction law of Seaton (1979) or Savage and Mathis (1979) should be replaced by the expression given by Cardelli et al. (1989), using the appropriate value of total-to-selective extinction. The older laws were appropriate for the diffuse ISM but dust in clouds differs dramatically in its extinction law. Dust is heavily processed while in the ISM by being included within clouds and cycled back into the diffuse ISM many times during its lifetime. Hence, grains probably reflect only a trace of their origin, although meteoritic inclusions with isotopic anomalies demonstrate that some tiny particles survive intact from a supernova origin to the present. 186 refs

  1. Mass Extinctions and Biosphere-Geosphere Stability

    Science.gov (United States)

    Rothman, Daniel; Bowring, Samuel

    2015-04-01

    Five times in the past 500 million years, mass extinctions have resulted in the loss of greater than three-fourths of living species. Each of these events is associated with significant environmental change recorded in the carbon-isotopic composition of sedimentary rocks. There are also many such environmental events in the geologic record that are not associated with mass extinctions. What makes them different? Two factors appear important: the size of the environmental perturbation, and the time scale over which it occurs. We show that the natural perturbations of Earth's carbon cycle during the past 500 million years exhibit a characteristic rate of change over two orders of magnitude in time scale. This characteristic rate is consistent with the maximum rate that limits quasistatic (i.e., near steady-state) evolution of the carbon cycle. We identify this rate with marginal stability, and show that mass extinctions occur on the fast, unstable side of the stability boundary. These results suggest that the great extinction events of the geologic past, and potentially a "sixth extinction" associated with modern environmental change, are characterized by common mechanisms of instability.

  2. Poor environmental tracking can make extinction risk insensitive to the colour of environmental noise

    Science.gov (United States)

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

    2011-01-01

    The relative importance of environmental colour for extinction risk compared with other aspects of environmental noise (mean and interannual variability) is poorly understood. Such knowledge is currently relevant, as climate change can cause the mean, variability and temporal autocorrelation of environmental variables to change. Here, we predict that the extinction risk of a shorebird population increases with the colour of a key environmental variable: winter temperature. However, the effect is weak compared with the impact of changes in the mean and interannual variability of temperature. Extinction risk was largely insensitive to noise colour, because demographic rates are poor in tracking the colour of the environment. We show that three mechanisms—which probably act in many species—can cause poor environmental tracking: (i) demographic rates that depend nonlinearly on environmental variables filter the noise colour, (ii) demographic rates typically depend on several environmental signals that do not change colour synchronously, and (iii) demographic stochasticity whitens the colour of demographic rates at low population size. We argue that the common practice of assuming perfect environmental tracking may result in overemphasizing the importance of noise colour for extinction risk. Consequently, ignoring environmental autocorrelation in population viability analysis could be less problematic than generally thought. PMID:21561978

  3. Pre-synaptic control of remote fear extinction in the neocortex

    Directory of Open Access Journals (Sweden)

    Gisella eVetere

    2012-06-01

    Full Text Available Consolidation of remote memory enhances immediate early genes induction (IEGs, augments the expression of the presynaptic growth associated protein 43 (GAP-43, and increases the density and size of dendritic spines in anterior cingulate (aCC and infra-limbic (ILC cortices. Remote memory extinction, however, does not uniformly alter consolidation-induced structural changes. In the aCC, the density, but not the size, of spines is reset to pseudo-conditioning levels while novel thin spines are formed in the ILC. Whether IEGs and GAP-43 also undergo region-specific changes upon remote memory extinction is undetermined. Here we confirm in the same batch of mice that c-Fos induction and GAP-43 expression are increased in both the aCC and the ILC 36 days after contextual fear conditioning. We then show that, in both regions, remote memory extinction is associated with decrease of c-Fos induction but no change in GAP-43 expression thus revealing similar, although protein-specific, pre-synaptic adaptations in aCC and ILC neurons. These observations, in addition to our previous report of region-specific post-synaptic structural changes, disclose a complex pattern of extinction-driven neocortical alterations suitable to support erasure or reinstatement of fear according to the environment demand.

  4. Cortisol modifies extinction learning of recently acquired fear in men

    Science.gov (United States)

    Hermann, Andrea; Stark, Rudolf; Wolf, Oliver Tobias

    2014-01-01

    Exposure therapy builds on the mechanism of fear extinction leading to decreased fear responses. How the stress hormone cortisol affects brain regions involved in fear extinction in humans is unknown. For this reason, we tested 32 men randomly assigned to receive either 30 mg hydrocortisone or placebo 45 min before fear extinction. In fear acquisition, a picture of a geometrical figure was either partially paired (conditioned stimulus; CS+) or not paired (CS−) with an electrical stimulation (unconditioned stimulus; UCS). In fear extinction, each CS was presented again, but no UCS occurred. Cortisol increased conditioned skin conductance responses in early and late extinction. In early extinction, higher activation towards the CS− than to the CS+ was found in the amygdala, hippocampus and posterior parahippocampal gyrus. This pattern might be associated with the establishment of a new memory trace. In late extinction, the placebo compared with the cortisol group displayed enhanced CS+/CS− differentiation in the amygdala, medial frontal cortex and nucleus accumbens. A change from early deactivation to late activation of the extinction circuit as seen in the placebo group seems to be needed to enhance extinction and to reduce fear. Cortisol appears to interfere with this process thereby impairing extinction of recently acquired conditioned fear. PMID:23945999

  5. The Sun-Earth connect 3: lessons from the periodicities of deep time influencing sea-level change and marine extinctions in the geological record.

    Science.gov (United States)

    Baker, Robert Gv; Flood, Peter G

    2015-01-01

    A number of papers since Rampino and Stothers published in Science 1984 have reported common periodicities in a wide range of climate, geomagnetic, tectonic and biological proxies, including marine extinctions. Single taper and multitaper spectral analysis of marine fluctuations between the Late Cretaceous and the Miocene replicates a number of the published harmonics. Whereas these common periodicities have been argued to have a galactic origin, this paper presents an alternative fractal model based on large scale fluctuations of the magnetic field of the Sun. The fluctuations follow a self-similar matrix of periodicities and the solutions of the differential equation allow for models to be constructed predicting extreme events for solar emissions. A comparison to major Phanerozoic extinction, climate and geomagnetic events, captured in the geological record, show a striking loop symmetry summarised in major 66 Ma irradiance and electromagnetic pulses from the Sun.

  6. Hydrocarbon Biomarker Stratigraphy of C-Isotopic Excursions Marking Chemical Changes in the Ocean with Contemporanious Biotic Extinction-Radiation Events

    Science.gov (United States)

    Summons, Roger E.

    2004-01-01

    One paper recording progress in this topic has been accepted for publication. We report a method for the rigorous identification of biomarkers (crocetane and PMI) that may be specific for methanotrophic and methanogenic archaea and, perhaps, the process of anaerobic oxidation of methane. If catastrophic methane efflux from sub-sea methane hydrate is responsible for extinction events, as has been hypothesized by many workers, then we might expect to find biomarkers for methane oxidation in sediments marking some extinction boundaries. Unfortunately, identifying crocetane and PMI with certainty is not a trivial exercise and these biomarkers appear to have been mis-identified in a recent publication by workers from Curtin University. Barber et al. (2001) identified crocetane and PMI in sediments deposited in the basal Triassic of the Perth Basin, Australia. However, Barber et al. (2001) also found crocetane and PMI in many other sediments and oils in a way that was inconsistent with our knowledge of these systems.

  7. Extinction correction and synchrotron radiation

    International Nuclear Information System (INIS)

    Suortti, P.

    1983-01-01

    The primary extinction factor ysub(p) is defined as the ratio of the integrated reflection from a coherently diffracting domain to the integrated kinematical reflection from the same domain. When ysub(p) is larger than 0.5 it may be approximated by ysub(p)= exp[-(αdelta) 2 ], where α is about 0.5 and delta the average size of the coherent domain when measured in units of the extinction length Λ, delta = D/Λ. Transfer equations are applied to symmetrical Laue diffraction, and the reflectivity per unit length, sigma(epsilon) is solved from the measured reflecting ratio as a function of the rocking angle epsilon = theta -thetasub(B). Measurements with conventional x-ray sources are made on single crystal slabs of Be and Si using AgKβ, MoKα 1 and CuKα radiation. The primary extinction factor ysub(p)(epsilon) is solved from a point-by-point comparison of two measurements where the extinction length Λ is changed by varying the polarization and/or wavelength of the x-ray beam. The results show that primary and secondary extinction are strongly correlated, and that the customary assumption of independent size and orientation distributions of crystal mosaics is unjustified. The structure factors for Be and Si show close agreement with other recent measurements and calculations. The limitations of the method are discussed in length, particularly the effects of beam divergences and incoherence of the rays in the crystal. It is concluded that under typical experimental conditions the requirements of the theory are met. Practical limitations arising from the use of characteristic wavelengths and unpolarized radiation prohibit the use of the full potential of the method. The properties of a synchrotron radiation source are compared with a conventional x-ray source, and it is demonstrated that the experimental limitations can be removed by the use of synchrotron radiation. A diffraction experiment with synchrotron radiation is outlined, as well as generalization of the

  8. Precision Photometric Extinction Corrections from Direct Atmospheric Measurements

    Science.gov (United States)

    McGraw, John T.; Zimmer, P.; Linford, J.; Simon, T.; Measurement Astrophysics Research Group

    2009-01-01

    For decades astronomical extinction corrections have been accomplished using nightly mean extinction coefficients derived from Langley plots measured with the same telescope used for photometry. Because this technique results in lost time on program fields, observers only grudgingly made sporadic extinction measurements. Occasionally extinction corrections are not measured nightly but are made using tabulated mean monthly or even quarterly extinction coefficients. Any observer of the sky knows that Earth's atmosphere is an ever-changing fluid in which is embedded extinction sources ranging from Rayleigh (molecular) scattering to aerosol, smoke and dust scattering and absorption, to "just plain cloudy.” Our eyes also tell us that the type, direction and degree of extinction changes on time scales of minutes or less - typically shorter than many astronomical observations. Thus, we should expect that atmospheric extinction can change significantly during a single observation. Mean extinction coefficients might be well-defined nightly means, but those means have high variance because they do not accurately record the wavelength-, time-, and angle-dependent extinction actually affecting each observation. Our research group is implementing lidar measurements made in the direction of observation with one minute cadence, from which the absolute monochromatic extinction can be measured. Simultaneous spectrophotometry of nearby bright standard stars allows derivation and MODTRAN modeling atmospheric transmission as a function of wavelength for the atmosphere through which an observation is made. Application of this technique is demonstrated. Accurate real-time extinction measurements are an enabling factor for sub-1% photometry. This research is supported by NSF Grant 0421087 and AFRL Grant #FA9451-04-2-0355.

  9. Biotic extinctions by solar flares; and reply

    International Nuclear Information System (INIS)

    Beland, P.; Russell, D.A.; Crutzen, P.J.; Reid, G.C.

    1976-01-01

    Some comments are offered on the paper by Reid and others (nature 259:177 (1976)) in which a mechanism was suggested by which solar protons might catastrophically deplete atmospheric D 3 during a reversal of the Earth's geomagnetic field. Organisms would thereby be exposed to a more intense UV environment, leading to species extinctions. These authors assumed that during a reversal the geomagnetic field effectively disappears for about 1000 years, and also that solar flares sufficiently intense to cause extinctions occur at intervals of 1000 years or more. The validity of these assumptions is here examined using data on geomagnetic reversals identified over the past 75 M years, together with extinction data, and some anomalies are pointed out. A reply by Reid and others is appended. (U.K.)

  10. Shifting baselines and the extinction of the Caribbean monk seal.

    Science.gov (United States)

    Baisre, Julio A

    2013-10-01

    The recent extinction of the Caribbean monk seal Monachus tropicalis has been considered an example of a human-caused extinction in the marine environment, and this species was considered a driver of the changes that have occurred in the structure of Caribbean coral reef ecosystems since colonial times. I searched archaeological records, historical data, and geographic names (used as a proxy of the presence of seals) and evaluated the use and quality of these data to conclude that since prehistoric times the Caribbean monk seal was always rare and vulnerable to human predation. This finding supports the hypothesis that in AD 1500, the Caribbean monk seal persisted as a small fragmented population in which individuals were confined to small keys, banks, or isolated islands in the Gulf of Mexico and the Caribbean Sea. This hypothesis is contrary to the assumption that the species was widespread and abundant historically. The theory that the main driver of monk seal extinction was harvesting for its oil for use in the sugar cane industry of Jamaica during the 18th century is based primarily on anecdotal information and is overemphasized in the literature. An analysis of reported human encounters with this species indicates monk seal harvest was an occasional activity, rather than an ongoing enterprise. Nevertheless, given the rarity of this species and its restricted distribution, even small levels of hunting or specimen collecting must have contributed to its extinction, which was confirmed in the mid-20th century. Some sources had been overlooked or only partially reviewed, others misinterpreted, and a considerable amount of anecdotal information had been uncritically used. Critical examination of archaeological and historical records is required to infer accurate estimations of the historical abundance of a species. In reconstructing the past to address the shifting baseline syndrome, it is important to avoid selecting evidence to confirm modern prejudices. © 2013

  11. Neural signals of vicarious extinction learning.

    Science.gov (United States)

    Golkar, Armita; Haaker, Jan; Selbing, Ida; Olsson, Andreas

    2016-10-01

    Social transmission of both threat and safety is ubiquitous, but little is known about the neural circuitry underlying vicarious safety learning. This is surprising given that these processes are critical to flexibly adapt to a changeable environment. To address how the expression of previously learned fears can be modified by the transmission of social information, two conditioned stimuli (CS + s) were paired with shock and the third was not. During extinction, we held constant the amount of direct, non-reinforced, exposure to the CSs (i.e. direct extinction), and critically varied whether another individual-acting as a demonstrator-experienced safety (CS + vic safety) or aversive reinforcement (CS + vic reinf). During extinction, ventromedial prefrontal cortex (vmPFC) responses to the CS + vic reinf increased but decreased to the CS + vic safety This pattern of vmPFC activity was reversed during a subsequent fear reinstatement test, suggesting a temporal shift in the involvement of the vmPFC. Moreover, only the CS + vic reinf association recovered. Our data suggest that vicarious extinction prevents the return of conditioned fear responses, and that this efficacy is reflected by diminished vmPFC involvement during extinction learning. The present findings may have important implications for understanding how social information influences the persistence of fear memories in individuals suffering from emotional disorders. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  12. Extinction of Learned Fear Induces Hippocampal Place Cell Remapping

    Science.gov (United States)

    Wang, Melissa E.; Yuan, Robin K.; Keinath, Alexander T.; Ramos Álvarez, Manuel M.

    2015-01-01

    The extinction of learned fear is a hippocampus-dependent process thought to embody new learning rather than erasure of the original fear memory, although it is unknown how these competing contextual memories are represented in the hippocampus. We previously demonstrated that contextual fear conditioning results in hippocampal place cell remapping and long-term stabilization of novel representations. Here we report that extinction learning also induces place cell remapping in C57BL/6 mice. Specifically, we observed cells that preferentially remapped during different stages of learning. While some cells remapped in both fear conditioning and extinction, others responded predominantly during extinction, which may serve to modify previous representations as well as encode new safe associations. Additionally, we found cells that remapped primarily during fear conditioning, which could facilitate reacquisition of the original fear association. Moreover, we also observed cells that were stable throughout learning, which may serve to encode the static aspects of the environment. The short-term remapping observed during extinction was not found in animals that did not undergo fear conditioning, or when extinction was conducted outside of the conditioning context. Finally, conditioning and extinction produced an increase in spike phase locking to the theta and gamma frequencies. However, the degree of remapping seen during conditioning and extinction only correlated with gamma synchronization. Our results suggest that the extinction learning is a complex process that involves both modification of pre-existing memories and formation of new ones, and these traces coexist within the same hippocampal representation. PMID:26085635

  13. Genetic disruptions of Drosophila Pavlovian learning leave extinction learning intact.

    Science.gov (United States)

    Qin, H; Dubnau, J

    2010-03-01

    Individuals who experience traumatic events may develop persistent posttraumatic stress disorder. Patients with this disorder are commonly treated with exposure therapy, which has had limited long-term success. In experimental neurobiology, fear extinction is a model for exposure therapy. In this behavioral paradigm, animals are repeatedly exposed in a safe environment to the fearful stimulus, which leads to greatly reduced fear. Studying animal models of extinction already has lead to better therapeutic strategies and development of new candidate drugs. Lack of a powerful genetic model of extinction, however, has limited progress in identifying underlying molecular and genetic factors. In this study, we established a robust behavioral paradigm to study the short-term effect (acquisition) of extinction in Drosophila melanogaster. We focused on the extinction of olfactory aversive 1-day memory with a task that has been the main workhorse for genetics of memory in flies. Using this paradigm, we show that extinction can inhibit each of two genetically distinct forms of consolidated memory. We then used a series of single-gene mutants with known impact on associative learning to examine the effects on extinction. We find that extinction is intact in each of these mutants, suggesting that extinction learning relies on different molecular mechanisms than does Pavlovian learning.

  14. Light extinction in the atmosphere

    International Nuclear Information System (INIS)

    Laulainen, N.

    1992-06-01

    Atmospheric aerosol particles originating from natural sources, such as volcanos and sulfur-bearing gas emissions from the oceans, and from human sources, such as sulfur emissions from fossil fuel combustion and biomass burning, strongly affect visual air quality and are suspected to significantly affect radiative climate forcing of the planet. During the daytime, aerosols obscure scenic vistas, while at night they diminish our ability to observe stellar objects. Scattering of light is the main means by which aerosols attenuate and redistribute light in the atmosphere and by which aerosols can alter and reduce visibility and potentially modify the energy balance of the planet. Trends and seasonal variability of atmospheric aerosol loading, such as column-integrated light extinction or optical depth, and how they may affect potential climate change have been difficult to quantify because there have been few observations made of important aerosol optical parameters, such as optical depth, over the globe and over time and often these are of uneven quality. To address questions related to possible climate change, there is a pressing need to acquire more high-quality aerosol optical depth data. Extensive deployment of improved solar radiometers over the next few years will provide higher-quality extinction data over a wider variety of locations worldwide. An often overlooked source of turbidity data, however, is available from astronomical observations, particularly stellar photoelectric photometry observations. With the exception of the Project ASTRA articles published almost 20 years ago, few of these data ever appear in the published literature. This paper will review the current status of atmospheric extinction observations, as highlighted by the ASTRA work and augmented by more recent solar radiometry measurements

  15. Verification ghosts. The changing political environment of the IAEA

    International Nuclear Information System (INIS)

    Redden, K.J.

    2003-01-01

    Six years ago, Dr. Hans Blix wrote in the IAEA Bulletin of a 'general optimism about further arms control and verification.' At the time, world events warranted such a prognosis; the IAEA was riding a wave of momentum after its instrumental role in the roll-back of the South African nuclear weapons program and bringing Ukraine, Belarus, and Kazakhstan into the Nuclear Non Proliferation Treaty (NPT) as non-nuclear-weapon States. The NPT's indefinite extension was only two years old, and the most pressing challenges, while recognizable, were somewhat stagnant. Today, some tidings elicit similar optimism. The IAEA's increasing efforts to combat terrorism and the decision by Member States to depart from nearly 20 years of zero real growth budgetary policy are remarkable testaments to the Agency's adaptability and credibility in the face of new threats. And with the worldwide frenzy over terrorism and redoubled phobia of weapons of mass destruction (WMD), the Agency garners public attention now as never before. Emblematic of this recent upsurge in political attention, US President George W. Bush's annual State of the Union address in 2003 mentioned supporting the IAEA as a specific priority of his administration, the first mention of the Agency in that speech since President Eisenhower in 1961 lauded its creation under 'Atoms for Peace'. Such visibility portends a future with prospects for overcoming bureaucratic inertia and effecting significant changes to the Agency's benefit. But with that visibility has come an uncertainty about the IAEA's role in world affairs. Despite being able to resolve most benign problems more easily, the Agency must operate in an environment haunted by the non-proliferation analogue of Charles Dickens' triumvirate specters: the ghosts of verification challenges past, present and future -namely, the cessation of UN-mandated inspections in Iraq, the difficulties ensuring compliance in North Korea and Iran, and the need to maintain the IAEA

  16. Taimyr Reindeer and Environmental Change: Monitoring Wild Reindeer Migration in Changing Natural and Social Environments

    Science.gov (United States)

    Petrov, A. N.

    2016-12-01

    The Taimyr Reindeer Herd (TRH) is both the largest and the longest monitored wild reindeer herd in Eurasia. An important part of Arctic ecosystems and Indigenous livelihood, wild reindeer have been continuously monitored for almost 50 years. During this time, herds have exhibited large changes in size and these changes have been recorded in almost all herds across the animal's range. An increasing number of wild reindeer in the Soviet times was followed by a significant population loss in the last decade. In addition, recent monitoring revealed substantial shifts in the distribution of wild populations. The decline in wild reindeer is likely related to natural cycles and changes in the Arctic environment caused by climate variability and anthropogenic activity. This study investigates patterns and possible drives of reindeer population dynamics in space and time. We identify key climatic factors, possible relationships with biomass dynamics, as well as with hunting practices and other human impacts.

  17. Selection, subdivision and extinction and recolonization.

    Science.gov (United States)

    Cherry, Joshua L

    2004-02-01

    In a subdivided population, the interaction between natural selection and stochastic change in allele frequency is affected by the occurrence of local extinction and subsequent recolonization. The relative importance of selection can be diminished by this additional source of stochastic change in allele frequency. Results are presented for subdivided populations with extinction and recolonization where there is more than one founding allele after extinction, where these may tend to come from the same source deme, where the number of founding alleles is variable or the founders make unequal contributions, and where there is dominance for fitness or local frequency dependence. The behavior of a selected allele in a subdivided population is in all these situations approximately the same as that of an allele with different selection parameters in an unstructured population with a different size. The magnitude of the quantity N(e)s(e), which determines fixation probability in the case of genic selection, is always decreased by extinction and recolonization, so that deleterious alleles are more likely to fix and advantageous alleles less likely to do so. The importance of dominance or frequency dependence is also altered by extinction and recolonization. Computer simulations confirm that the theoretical predictions of both fixation probabilities and mean times to fixation are good approximations.

  18. Extinction of sodium fires

    International Nuclear Information System (INIS)

    Malet, J.C.; Spagna, F.

    1989-01-01

    This paper presents how, starting from a knowledge of sodium ignition and burning, principles for extinction (smothering catch trays, leak recuperation systems, powders) can be developed. These techniques applied in Superphenix 1 and PEC reactors have been tested in the ESMERALDA experimental program which is a joint French/Italian project. (author)

  19. Fear extinction requires infralimbic cortex projections to the basolateral amygdala.

    Science.gov (United States)

    Bloodgood, Daniel W; Sugam, Jonathan A; Holmes, Andrew; Kash, Thomas L

    2018-03-06

    Fear extinction involves the formation of a new memory trace that attenuates fear responses to a conditioned aversive memory, and extinction impairments are implicated in trauma- and stress-related disorders. Previous studies in rodents have found that the infralimbic prefrontal cortex (IL) and its glutamatergic projections to the basolateral amygdala (BLA) and basomedial amygdala (BMA) instruct the formation of fear extinction memories. However, it is unclear whether these pathways are exclusively involved in extinction, or whether other major targets of the IL, such as the nucleus accumbens (NAc) also play a role. To address this outstanding issue, the current study employed a combination of electrophysiological and chemogenetic approaches in mice to interrogate the role of IL-BLA and IL-NAc pathways in extinction. Specifically, we used patch-clamp electrophysiology coupled with retrograde tracing to examine changes in neuronal activity of the IL and prelimbic cortex (PL) projections to both the BLA and NAc following fear extinction. We found that extinction produced a significant increase in the intrinsic excitability of IL-BLA projection neurons, while extinction appeared to reverse fear-induced changes in IL-NAc projection neurons. To establish a causal counterpart to these observations, we then used a pathway-specific Designer Receptors Exclusively Activated by Designer Drugs (DREADD) strategy to selectively inhibit PFC-BLA projection neurons during extinction acquisition. Using this approach, we found that DREADD-mediated inhibition of PFC-BLA neurons during extinction acquisition impaired subsequent extinction retrieval. Taken together, our findings provide further evidence for a critical contribution of the IL-BLA neural circuit to fear extinction.

  20. Distribution and extinction of ungulates during the Holocene of the southern Levant.

    Directory of Open Access Journals (Sweden)

    Ella Tsahar

    Full Text Available BACKGROUND: The southern Levant (Israel, Palestinian Authority and Jordan has been continuously and extensively populated by succeeding phases of human cultures for the past 15,000 years. The long human impact on the ancient landscape has had great ecological consequences, and has caused continuous and accelerating damage to the natural environment. The rich zooarchaeological data gathered at the area provide a unique opportunity to reconstruct spatial and temporal changes in wild species distribution, and correlate them with human demographic changes. METHODOLOGY: Zoo-archaeological data (382 animal bone assemblages from 190 archaeological sites from various time periods, habitats and landscapes were compared. The bone assemblages were sorted into 12 major cultural periods. Distribution maps showing the presence of each ungulate species were established for each period. CONCLUSIONS: The first major ungulate extinction occurred during the local Iron Age (1,200-586 BCE, a period characterized by significant human population growth. During that time the last of the largest wild ungulates, the hartebeest (Alcelaphus buselaphus, aurochs (Bos primigenius and the hippopotamus (Hippopotamus amphibius became extinct, followed by a shrinking distribution of forest-dwelling cervids. A second major wave of extinction occurred only in the 19th and 20th centuries CE. Furthermore, a negative relationship was found between the average body mass of ungulate species that became extinct during the Holocene and their extinction date. It is thus very likely that the intensified human activity through habitat destruction and uncontrolled hunting were responsible for the two major waves of ungulate extinction in the southern Levant during the late Holocene.

  1. Distribution and extinction of ungulates during the Holocene of the southern Levant.

    Science.gov (United States)

    Tsahar, Ella; Izhaki, Ido; Lev-Yadun, Simcha; Bar-Oz, Guy

    2009-01-01

    The southern Levant (Israel, Palestinian Authority and Jordan) has been continuously and extensively populated by succeeding phases of human cultures for the past 15,000 years. The long human impact on the ancient landscape has had great ecological consequences, and has caused continuous and accelerating damage to the natural environment. The rich zooarchaeological data gathered at the area provide a unique opportunity to reconstruct spatial and temporal changes in wild species distribution, and correlate them with human demographic changes. Zoo-archaeological data (382 animal bone assemblages from 190 archaeological sites) from various time periods, habitats and landscapes were compared. The bone assemblages were sorted into 12 major cultural periods. Distribution maps showing the presence of each ungulate species were established for each period. The first major ungulate extinction occurred during the local Iron Age (1,200-586 BCE), a period characterized by significant human population growth. During that time the last of the largest wild ungulates, the hartebeest (Alcelaphus buselaphus), aurochs (Bos primigenius) and the hippopotamus (Hippopotamus amphibius) became extinct, followed by a shrinking distribution of forest-dwelling cervids. A second major wave of extinction occurred only in the 19th and 20th centuries CE. Furthermore, a negative relationship was found between the average body mass of ungulate species that became extinct during the Holocene and their extinction date. It is thus very likely that the intensified human activity through habitat destruction and uncontrolled hunting were responsible for the two major waves of ungulate extinction in the southern Levant during the late Holocene.

  2. Biogeographic and bathymetric determinants of brachiopod extinction and survival during the Late Ordovician mass extinction

    DEFF Research Database (Denmark)

    Finnegan, Seth; Mac Ørum Rasmussen, Christian; Harper, David A. T.

    2016-01-01

    –Early Silurian genus extinctions and evaluate which extinction drivers are best supported by the data. The first (latest Katian) pulse of the LOME preferentially affected genera restricted to deeper waters or to relatively narrow (less than 35°) palaeolatitudinal ranges. This pattern is only observed...... in the latest Katian, suggesting that it reflects drivers unique to this interval. Extinction of exclusively deeper-water genera implies that changes in water mass properties such as dissolved oxygen content played an important role. Extinction of genera with narrow latitudinal ranges suggests that interactions...... between shifting climate zones and palaeobiogeography may also have been important. We test the latter hypothesis by estimating whether each genus would have been able to track habitats within its thermal tolerance range during the greenhouse–icehouse climate transition. Models including these estimates...

  3. Extinction Generates Outcome-Specific Conditioned Inhibition.

    Science.gov (United States)

    Laurent, Vincent; Chieng, Billy; Balleine, Bernard W

    2016-12-05

    Extinction involves altering a previously established predictive relationship between a cue and its outcome by repeatedly presenting that cue alone. Although it is widely accepted that extinction generates some form of inhibitory learning [1-4], direct evidence for this claim has been lacking, and the nature of the associative changes induced by extinction have, therefore, remained a matter of debate [5-8]. In the current experiments, we used a novel behavioral approach that we recently developed and that provides a direct measure of conditioned inhibition [9] to compare the influence of extinguished and non-extinguished cues on choice between goal-directed actions. Using this approach, we provide direct evidence that extinction generates outcome-specific conditioned inhibition. Furthermore, we demonstrate that this inhibitory learning is controlled by the infralimbic cortex (IL); inactivation of the IL using M4 DREADDs abolished outcome-specific inhibition and rendered the cue excitatory. Importantly, we found that context modulated this inhibition. Outside its extinction context, the cue was excitatory and functioned as a specific predictor of its previously associated outcome, biasing choice toward actions earning the same outcome. In its extinction context, however, the cue acted as a specific inhibitor and biased choice toward actions earning different outcomes. Context modulation of these excitatory and inhibitory memories was mediated by the dorsal hippocampus (HPC), suggesting that the HPC and IL act in concert to control the influence of conditioned inhibitors on choice. These findings demonstrate for the first time that extinction turns a cue into a net inhibitor that can influence choice via counterfactual action-outcome associations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Elevational distribution and extinction risk in birds.

    Directory of Open Access Journals (Sweden)

    Rachel L White

    Full Text Available Mountainous regions are hotspots of terrestrial biodiversity. Unlike islands, which have been the focus of extensive research on extinction dynamics, fewer studies have examined mountain ranges even though they face increasing threats from human pressures - notably habitat conversion and climate change. Limits to the taxonomic and geographical extent and resolution of previously available information have precluded an explicit assessment of the relative role of elevational distribution in determining extinction risk. We use a new global species-level avian database to quantify the influence of elevational distribution (range, maximum and midpoint on extinction risk in birds at the global scale. We also tested this relationship within biogeographic realms, higher taxonomic levels, and across phylogenetic contrasts. Potential confounding variables (i.e. phylogenetic, distributional, morphological, life history and niche breadth were also tested and controlled for. We show that the three measures of elevational distribution are strong negative predictors of avian extinction risk, with elevational range comparable and complementary to that of geographical range size. Extinction risk was also found to be positively associated with body weight, development and adult survival, but negatively associated with reproduction and niche breadth. The robust and consistent findings from this study demonstrate the importance of elevational distribution as a key driver of variation in extinction dynamics in birds. Our results also highlight elevational distribution as a missing criterion in current schemes for quantifying extinction risk and setting species conservation priorities in birds. Further research is recommended to test for generality across non-avian taxa, which will require an advance in our knowledge of species' current elevational ranges and increased efforts to digitise and centralise such data.

  5. Ecotones in a changing environment: Workshop on ecotones and global change

    Energy Technology Data Exchange (ETDEWEB)

    Risser, P.G.

    1990-02-01

    The Scientific Committee on Problems of the Environment (SCOPE) has organized an international project to synthesize and advance current theory on the influence of ecotones, or transition zones between ecosystems, on biodiversity and flows of energy, nutrients, water, and project is other materials between ecosystems. In particular, the entire project is designed to evaluate the influence of global climate change and land-use practices on biodiversity and ecological flows associated with ecotones, and will assess the feasibility of monitoring ecotones as early indicators of global change. The later stages of the project will recommend landscape management strategies for ecotones that produce desirable patterns of biodiversity and ecological flows. The result of the project--a comprehensive body of information on the theory and management of biodiversity and ecological flows associated with ecotones--will be part of the planning for research to be carried out under the International Geosphere-Biosphere Program.

  6. The impact of business environment changes on recent costing techniques

    Institute of Scientific and Technical Information of China (English)

    林慧涓

    2011-01-01

    1.Introduction The acceleration of globalization and the prosperity of information technology benefit business a great deal.But with the speeding up of economic development,firms are facing more and more pressure from various aspects of their business.The heated debate is on about whether traditional management accounting practices and techniques are irrelevant to the current business environment and this essay will explore the causes for using some traditional management accounting practices and techniques in the current business environment are inappropriate and put forward some contemporary management accounting techniques which is relevant to the current business environment.Thus,the essay will be divided into three sections to discuss the traditional management accounting practices and techniques and contemporary management accounting techniques in current business environment.

  7. On the trap of extinction and its elimination

    International Nuclear Information System (INIS)

    Vitanov, Nikolay K.; Dimitrova, Zlatinka I.; Kantz, Holger

    2006-01-01

    We investigate the dynamics of a system of three interacting populations in presence of extinction and substitution: each population whose number of individuals drops under some threshold value becomes extinct, and it is substituted by another population with different fitness and different coefficients of interaction with the other populations. We study the influence of extinction on the system states, which in the absence of extinction can be fixed points, limit cycles or chaotic attractors of Shilnikov kind. The extinction can destabilize each of these states. We observe two possible kinds of evolution in the destabilized system: (i) it can remain forever in the trap of extinction, i.e., the extinctions and substitutions of populations continue for indefinitely long time or (ii) it can avoid the trap of extinction by means of the substitution, i.e., the fitness and the coefficients of the interactions between the species move the system attractor away from the zone of the threshold values, the extinction stops, and the system settles on a new attractor. The obtained results are discussed from the point of view of products competing for the preference of buyers that can change their opinion

  8. Astrophysical life extinctions what killed the dinosaurs?

    CERN Document Server

    Dar, Arnon

    1999-01-01

    Geological records indicate that the exponential diversification of marine and continental life on Earth in the past 500 My was interrupted by many life extinctions. They also indicate that the major mass extinctions were correlated in time with large meteoritic impacts, gigantic volcanic eruptions, sea regressions and drastic changes in global climate. Some of these catastrophes coincided in time. The astrophysical life extinction mechanisms which were proposed so far, in particular, meteoritic impacts, nearby supernova explosions, passage through molecular or dark matter clouds, and Galactic gamma/cosmic ray bursts cannot explain the time coincidences between these catastrophes. However, recent observations suggest that many planetary-mass objects may be present in the outer solar system between the Kuiper belt and the Oort cloud. Gravitational perturbations may occasionally bring them into the inner solar system. Their passage near Earth could have generated gigantic tidal waves, large volcanic eruptions, ...

  9. Time to extinction of bird populations

    NARCIS (Netherlands)

    Sæther, B-E.; Engen, S.; Møller, A.P.; Visser, M.E.; Matthysen, E.; Fiedler, W.; Lambrechts, M.M.; Becker, P.H.; Brommer, J.E.; Dickinson, J.; du Feu, C.; Gehlbach, F.R.; Merilä, J.; Rendell, W.; Robertson, R.J.; Thomson, D.L.; Török, J.

    2005-01-01

    The risk of extinction of populations has not previously been empirically related to parameters characterizing their population dynamics. To analyze this relationship, we simulated how the distribution of population dynamical characters changed as a function of time, in both the remaining and the

  10. Dietary specialization during the evolution of Western Eurasian hominoids and the extinction of European Great Apes.

    Directory of Open Access Journals (Sweden)

    Daniel DeMiguel

    Full Text Available Given the central adaptive role of diet, paleodietary inference is essential for understanding the relationship between evolutionary and paleoenvironmental change. Here we rely on dental microwear analysis to investigate the role of dietary specialization in the diversification and extinction of Miocene hominoids from Western Eurasian between 14 and 7 Ma. New microwear results for five extinct taxa are analyzed together with previous data for other Western Eurasian genera. Except Pierolapithecus (that resembles hard-object feeders and Oreopithecus (a soft-frugivore probably foraging opportunistically on other foods, most of the extinct taxa lack clear extant dietary analogues. They display some degee of sclerocarpy, which is most clearly expressed in Griphopithecus and Ouranopithecus (adapted to more open and arid environments, whereas Anoiapithecus, Dryopithecus and, especially, Hispanopithecus species apparently relied more strongly on soft-frugivory. Thus, contrasting with the prevailing sclerocarpic condition at the beginning of the Eurasian hominoid radiation, soft- and mixed-frugivory coexisted with hard-object feeding in the Late Miocene. Therefore, despite a climatic trend towards cooling and increased seasonality, a progressive dietary diversification would have occurred (probably due to competitive exclusion and increased environmental heterogeneity, although strict folivory did not evolve. Overall, our analyses support the view that the same dietary specializations that enabled Western Eurasian hominoids to face progressive climatic deterioration were the main factor ultimately leading to their extinction when more drastic paleoenvironmental changes took place.

  11. THE SECONDARY EXTINCTION CORRECTION

    Energy Technology Data Exchange (ETDEWEB)

    Zachariasen, W. H.

    1963-03-15

    It is shown that Darwin's formula for the secondary extinction correction, which has been universally accepted and extensively used, contains an appreciable error in the x-ray diffraction case. The correct formula is derived. As a first order correction for secondary extinction, Darwin showed that one should use an effective absorption coefficient mu + gQ where an unpolarized incident beam is presumed. The new derivation shows that the effective absorption coefficient is mu + 2gQ(1 + cos/sup 4/2 theta )/(1 plus or minus cos/sup 2/2 theta )/s up 2/, which gives mu + gQ at theta =0 deg and theta = 90 deg , but mu + 2gQ at theta = 45 deg . Darwin's theory remains valid when applied to neutron diffraction. (auth)

  12. Galactic dust and extinction

    International Nuclear Information System (INIS)

    Lyngaa, G.

    1979-01-01

    The ratio R between visual extinction and colour excess, is slightly larger than 3 and does not vary much throughout our part of the Galaxy. The distribution of dust in the galactic plane shows, on the large scale, a gradient with higher colour excesses towards l=50 0 than towards l=230 0 . On the smaller scale, much of the dust responsible for extinction is situated in clouds which tend to group together. The correlation between positions of interstellar dust clouds and positions of spiral tracers seems rather poor in our Galaxy. However, concentrated dark clouds as well as extended regions of dust show an inclined distribution similar to the Gould belt of bright stars. (Auth.)

  13. Arctic alpine ecosystems and people in a changing environment

    National Research Council Canada - National Science Library

    Ørbæk, Jon Børre

    2007-01-01

    ... for the population structures and the interaction between species. These changes may also have socio-economic effects if the changes affect the bio-production, which form the basis for the marine and terrestrial food chains. The book is uniquely multidisciplinary and provides examples of various aspects of contemporary environmental change in arctic and ...

  14. Evidence for change in depositional environment in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.; Rao, Ch.M.

    Sediments of late Pleistocene and Holocene periods, from a 12 m long core collected at a depth of 3627 m from the Arabian Sea, have been studied in order to understand the depositional environment. Sub-samples selected at 5 cm and occasionally at 10...

  15. Lactic acid bacteria in a changing legislative environment

    NARCIS (Netherlands)

    Feord, J.

    2002-01-01

    The benefits of using lactic acid bacteria in the food chain, both through direct consumption and production of ingredients, are increasingly recognised by the food industry and consumers alike. The regulatory environment surrounding these products is diverse, covering foods and food ingredients,

  16. Constant Change: The Ever-Evolving Personal Learning Environment

    Science.gov (United States)

    Torres Kompen, Ricardo; Monguet, Josep Ma.; Brigos, Miguel

    2015-01-01

    There are several definitions for the term "personal learning environment" (PLE); in this article, PLE refers to a group of web technologies, with various degrees of integration and interaction, that helps users and learners manage the flow of information that relates to the learning process, the creation of knowledge, and the…

  17. Planning Intentionally for Children's Outdoor Environments: The Gift of Change

    Science.gov (United States)

    Rosenow, Nancy

    2011-01-01

    When the author was a child 50 years ago, nobody planned her outdoor environment. Her home was close to flower-filled meadows that she could explore freely, and her preschool and elementary school classrooms opened onto beautiful woodlands that children used as an important part of their day-to-day learning. The last time she visited her old…

  18. Late Pleistocene and Holocene mammal extinctions on continental Africa

    Science.gov (United States)

    Faith, J. Tyler

    2014-01-01

    Understanding the cause of late Quaternary mammal extinctions is the subject of intense debate spanning the fields of archeology and paleontology. In the global context, the losses on continental Africa have received little attention and are poorly understood. This study aims to inspire new discussion of African extinctions through a review of the extinct species and the chronology and possible causes of those extinctions. There are at least 24 large mammal (> 5 kg) species known to have disappeared from continental Africa during the late Pleistocene or Holocene, indicating a much greater taxonomic breadth than previously recognized. Among the better sampled taxa, these losses are restricted to the terminal Pleistocene and early Holocene, between 13,000 and 6000 yrs ago. The African extinctions preferentially affected species that are grazers or prefer grasslands. Where good terrestrial paleoenvironmental records are present, extinctions are associated with changes in the availability, productivity, or structure of grassland habitats, suggesting that environmental changes played a decisive role in the losses. In the broader evolutionary context, these extinctions represent recent examples of selective taxonomic winnowing characterized by the loss of grassland specialists and the establishment of large mammal communities composed of more ecologically flexible taxa over the last million years. There is little reason to believe that humans played an important role in African extinctions.

  19. Northern hydrology and water resources in a changing environment

    International Nuclear Information System (INIS)

    Kane, D.L.

    1993-01-01

    The role that climatic change may play in altering various components of the hydrologic cycle in Arctic regions is discussed. The hydrologic setting of these regions is first described, noting the importance of subsurface freezing and thawing on hydrologic pathways and the lack of incorporation of soil freezing and thawing into climate models. Major processes of interest in the relation between climate change and hydrology are the timing and magnitude of fluxes entering and leaving a basin: precipitation, evaporation and transpiration, and runoff. The active layer of the soil could be drastically increased by only a few degrees of surface warming. The natural hydrologic cycle has considerable yearly variation, tending to mask any hydrologic changes caused by climatic change. There are too many unknowns at present for an adequate prediction of the impact of climate change on the hydrologic cycle. The biggest uncertainty is how the timing and quantity of precipitation is going to change. This quantity could be altered by any major changes in vegetation, which would be closely related to the amount of warming. In hydrologic scenarios where air temperature rises 4 degree C over 50 y, under stable, high, and low precipitation conditions, there are no significant changes in hydrologic response. 24 refs., 6 figs

  20. Agents of Change: Studies on the Policy Environment for Small ...

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

    Agents of Change presents the results of an international conference held in Africa. It provides practical solutions and suggestions for real change. It discusses national strategies for small enterprises, examines legal, regulatory, and tax reform, and makes proposals on how to improve competitiveness and access to credit.

  1. Climate Change and Societal Response: Livelihoods, Communities, and the Environment

    Science.gov (United States)

    Molnar, Joseph J.

    2010-01-01

    Climate change may be considered a natural disaster evolving in slow motion on a global scale. Increasing storm intensities, shifting rainfall patterns, melting glaciers, rising sea levels, and other manifold alterations are being experienced around the world. Climate has never been constant in any location, but human-induced changes associated…

  2. Sugarcane ethanol: contributions to climate change mitigation and the environment

    NARCIS (Netherlands)

    Zuurbier, P.J.P.; Vooren, van de J.G.

    2008-01-01

    Climate change is a challenge facing human life. It will change mobility and asks for new energy solutions. Bioenergy has gained increased attention as an alternative to fossil fuels. Energy based on renewable sources may offer part of the solution. Bio ethanol based on sugar cane offers advantages

  3. Change management in library environments: A comparative study ...

    African Journals Online (AJOL)

    The purpose of the study was to examine change management in public and private university libraries in Ghana, identify possible problems in order to make recommendations to enhance future change assignments. The study adopted the survey approach as the research design. The Statistical Package for Social ...

  4. Movers and stayers: Novel assemblages in changing environments

    Science.gov (United States)

    Hobbs, Richard L.; Valentine, Leonie E.; Standish, Rachel J.; Jackson, Stephen T.

    2018-01-01

    How species will respond to ongoing climate and other change is of increasing concern.Most attention is given to how species move or are moved, but many species stay.Understanding the dynamics of new species combinations is essential for successful conservation in a changing climate.Increased attention to species movement in response to environmental change highlights the need to consider changes in species distributions and altered biological assemblages. Such changes are well known from paleoecological studies, but have accelerated with ongoing pervasive human influence. In addition to species that move, some species will stay put, leading to an array of novel interactions. Species show a variety of responses that can allow movement or persistence. Conservation and restoration actions have traditionally focused on maintaining or returning species in particular places, but increasingly also include interventions that facilitate movement. Approaches are required that incorporate the fluidity of biotic assemblages into the goals set and interventions deployed.

  5. Adapting Evaluations of Alternative Payment Models to a Changing Environment.

    Science.gov (United States)

    Grannemann, Thomas W; Brown, Randall S

    2018-04-01

    To identify the most robust methods for evaluating alternative payment models (APMs) in the emerging health care delivery system environment. We assess the impact of widespread testing of alternative payment models on the ability to find credible comparison groups. We consider the applicability of factorial research designs for assessing the effects of these models. The widespread adoption of alternative payment models could effectively eliminate the possibility of comparing APM results with a "pure" control or comparison group unaffected by other interventions. In this new environment, factorial experiments have distinct advantages over the single-model experimental or quasi-experimental designs that have been the mainstay of recent tests of Medicare payment and delivery models. The best prospects for producing definitive evidence of the effects of payment incentives for APMs include fractional factorial experiments that systematically vary requirements and payment provisions within a payment model. © Health Research and Educational Trust.

  6. Changing the Food Environment: The French Experience12

    OpenAIRE

    Chauliac, Michel; Hercberg, Serge

    2012-01-01

    The French National Nutrition and Health Program was launched in 2001. To achieve its objectives, 2 main preventive strategies were identified: 1) provide information and education to help individuals make healthy food and physical activity choices; and 2) improve the food and physical environment so that making healthy choices is easier. School regulations have been established to improve the nutritional quality of meals served to children and adolescents, and vending machines have been bann...

  7. 3,4-Methylenedioxymethamphetamine facilitates fear extinction learning.

    Science.gov (United States)

    Young, M B; Andero, R; Ressler, K J; Howell, L L

    2015-09-15

    Acutely administered 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') has been proposed to have long-term positive effects on post-traumatic stress disorder (PTSD) symptoms when combined with psychotherapy. No preclinical data support a mechanistic basis for these claims. Given the persistent nature of psychotherapeutic gains facilitated by MDMA, we hypothesized that MDMA improves fear extinction learning, a key process in exposure-based therapies for PTSD. In these experiments, mice were first exposed to cued fear conditioning and treated with drug vehicle or MDMA before extinction training 2 days later. MDMA was administered systemically and also directly targeted to brain structures known to contribute to extinction. In addition to behavioral measures of extinction, changes in mRNA levels of brain-derived neurotrophic factor (Bdnf) and Fos were measured after MDMA treatment and extinction. MDMA (7.8 mg kg(-1)) persistently and robustly enhanced long-term extinction when administered before extinction training. MDMA increased the expression of Fos in the amygdala and medial prefrontal cortex (mPFC), whereas increases in Bdnf expression were observed only in the amygdala after extinction training. Extinction enhancements were recapitulated when MDMA (1 μg) was infused directly into the basolateral complex of the amygdala (BLA), and enhancement was abolished when BDNF signaling was inhibited before extinction. These findings suggest that MDMA enhances fear memory extinction through a BDNF-dependent mechanism, and that MDMA may be a useful adjunct to exposure-based therapies for PTSD and other anxiety disorders characterized by altered fear learning.

  8. Electric system reliability considerations in a changing utility environment

    International Nuclear Information System (INIS)

    Kramer, R.A.

    1991-01-01

    The utility industry is presently experiencing a number of diverse factors which may alter the way that it operates and in many cases the way in which it is configured. These factors reflect a variety of circumstances including increased competitive pressures and political perception. While many of these changes may result in long term economic and service benefits to the industry and customer alike, it is important to recognize the desirability of orderly change. There is need to implement change in a reasoned manner. In this paper technical as well as economic and political considerations are addressed

  9. Climate Change Impacts on the Built Environment in Nigeria

    African Journals Online (AJOL)

    Toshiba

    global climate change and the urgent need for energy efficient infrastructure and .... may be the use of floodplain maps to steer development away from flood prone ..... Hayhoe K, Wake C, Huntington T, Luo L, Schwartz M, Sheffield J,. Wood E ...

  10. Assessing and managing stressors in a changing marine environment.

    Science.gov (United States)

    Chapman, Peter M

    2017-11-30

    We are facing a dynamic future in the face of multiple stressors acting individually and in combination: climate change; habitat change/loss; overfishing; invasive species; harmful algal blooms/eutrophication; and, chemical contaminants. Historic assessment and management approaches will be inadequate for addressing risks from climate change and other stressors. Wicked problems (non-linear, complex, competing risks and benefits, not easily solvable), will become increasingly common. We are facing irreversible changes to our planetary living conditions. Agreed protection goals and considering both the negatives (risks) and the positives (benefits) of all any and all actions are required, as is judicious and appropriate use of the Precautionary Principle. Researchers and managers need to focus on: determining tipping points (alternative stable points); maintaining ecosystem services; and, managing competing ecosystem services. Marine (and other) scientists are urged to focus their research on wicked problems to allow for informed decision-making on a planetary basis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. A look at the changing environment along the Indian coasts

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, B.N.; Das, V.K.

    Increased human activity along the Indian coastline has exerted pressure on its morphology and ecology. The factors responsible for morphological changes like subsidence, rising sea level, storms, storm surges, sediment input from rivers, sediment...

  12. Climate change, adaptation and the environment in central Vietnam

    DEFF Research Database (Denmark)

    Bruun, Ole; Casse, Thorkil

    2013-01-01

    There is an urgent need for integrated approaches, such as the building of environmental management into climate change responses, addressing the total impact of livelihood stresses in social vulnerability perspectives, and ensuring that overall adaptation policies adequately address social justice...

  13. 670 investigating changes in coastal environment using internet

    African Journals Online (AJOL)

    Osondu

    investigation of land use/land cover (LU/LC) changes. The results obtained tend ... mainstay of the people. (marine, tourism and fishing activities) has been adversely affected. ... can refer to biotic and abiotic features, including soil, topography,.

  14. Uncertainty and learning in a strategic environment. Global climate change

    International Nuclear Information System (INIS)

    Baker, Erin

    2005-01-01

    Global climate change is rife with uncertainties. Yet, we can expect to resolve much of this uncertainty in the next 100 years or so. Therefore, current actions should reflect the value of flexibility. Nevertheless, most models of climate change, particularly game-theoretic models, abstract from uncertainty. A model of the impacts of uncertainty and learning in a non-cooperative game shows that the level of correlation of damages across countries is crucial for determining optimal policy

  15. Knowledge Sharing Mechanism: Enabling C2 to Adapt to Changing Environments

    National Research Council Canada - National Science Library

    Harvie, David P

    2007-01-01

    .... The common nemesis to successfully developing solutions in these environments is change. The challenge of any complex problem solving process is the balance of adapting to multiple changes while keeping focused on the overall desired solution...

  16. The Future of Nonproliferation in a Changed and Changing Environment: A Workshop Summary

    International Nuclear Information System (INIS)

    Dreicer, M.

    2016-01-01

    The Center for Global Security Research and Global Security Principal Directorate at Lawrence Livermore National Laboratory convened a workshop in July 2016 to consider ''The Future of Nonproliferation in a Changed and Changing Security Environment.'' We took a broad view of nonproliferation, encompassing not just the treaty regime but also arms control, threat reduction, counter-roliferation, and countering nuclear terrorism. We gathered a group of approximately 60 experts from the technical, academic, political, defense and think tank communities and asked them what and how much can reasonably be accomplished in each of these areas in the 5 to 10 years ahead. Discussion was on a not-for-attribution basis. This document provides a summary of key insights and lessons learned, and is provided to help stimulate broader public discussion of these issues. It is a collection of ideas as informally discussed and debated among a group of experts. The ideas reported here are the personal views of individual experts and should not be attributed to Lawrence Livermore National Laboratory.

  17. The Future of Nonproliferation in a Changed and Changing Environment: A Workshop Summary

    Energy Technology Data Exchange (ETDEWEB)

    Dreicer, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-08-30

    The Center for Global Security Research and Global Security Principal Directorate at Lawrence Livermore National Laboratory convened a workshop in July 2016 to consider “The Future of Nonproliferation in a Changed and Changing Security Environment.” We took a broad view of nonproliferation, encompassing not just the treaty regime but also arms control, threat reduction, counter-­proliferation, and countering nuclear terrorism. We gathered a group of approximately 60 experts from the technical, academic, political, defense and think tank communities and asked them what—and how much—can reasonably be accomplished in each of these areas in the 5 to 10 years ahead. Discussion was on a not-­for-­attribution basis. This document provides a summary of key insights and lessons learned, and is provided to help stimulate broader public discussion of these issues. It is a collection of ideas as informally discussed and debated among a group of experts. The ideas reported here are the personal views of individual experts and should not be attributed to Lawrence Livermore National Laboratory.

  18. Modelling interstellar extinction: Pt. 1

    International Nuclear Information System (INIS)

    Jones, A.P.

    1988-01-01

    Several methods of calculating the extinction of porous silicate grains are discussed, these include effective medium theories and hollow spherical shells. Porous silicate grains are shown to produce enhanced infrared, ultraviolet and far-ultraviolet extinction and this effect can be used to reduce the abundance of carbon required to match the average interstellar extinction, however, matching the visual extinction is rather more problematical. We have shown that the enhanced extinction at long and short wavelengths have different origins, and have explained why the visual extinction is little affected by porosity. The implications of porous grains in the interstellar medium are discussed with particular reference to surface chemistry, the polarization of starlight, and their dynamical evolution. (author)

  19. Extinction Events Can Accelerate Evolution

    DEFF Research Database (Denmark)

    Lehman, Joel; Miikkulainen, Risto

    2015-01-01

    Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate...... evolution by increasing evolvability. In particular, if extinction events extinguish indiscriminately many ways of life, indirectly they may select for the ability to expand rapidly through vacated niches. Lineages with such an ability are more likely to persist through multiple extinctions. Lending...... computational support for this hypothesis, this paper shows how increased evolvability will result from simulated extinction events in two computational models of evolved behavior. The conclusion is that although they are destructive in the short term, extinction events may make evolution more prolific...

  20. Variations in ultraviolet extinction: effect of polarization revisited

    International Nuclear Information System (INIS)

    Greenberg, J.M.; Chlewicki, G.; Rijksuniversiteit Groningen

    1987-01-01

    The alignment of the particles responsible for the polarization and visual extinction is shown to provide a basis for changing the saturation level of the ultraviolet extinction without changing the particle sizes. If the particles are well aligned, it is predicted that there should be significantly lower extinction in the ultraviolet relative to the visible for stars viewed perpendicular to magnetic-field lines (maximum polarization) as compared with those viewed across the field lines. Preliminary evidence for such an effect is noted in Carina. (author)

  1. Development of the virtual research environment for analysis, evaluation and prediction of global climate change impacts on the regional environment

    Science.gov (United States)

    Okladnikov, Igor; Gordov, Evgeny; Titov, Alexander; Fazliev, Alexander

    2017-04-01

    Description and the first results of the Russian Science Foundation project "Virtual computational information environment for analysis, evaluation and prediction of the impacts of global climate change on the environment and climate of a selected region" is presented. The project is aimed at development of an Internet-accessible computation and information environment providing unskilled in numerical modelling and software design specialists, decision-makers and stakeholders with reliable and easy-used tools for in-depth statistical analysis of climatic characteristics, and instruments for detailed analysis, assessment and prediction of impacts of global climate change on the environment and climate of the targeted region. In the framework of the project, approaches of "cloud" processing and analysis of large geospatial datasets will be developed on the technical platform of the Russian leading institution involved in research of climate change and its consequences. Anticipated results will create a pathway for development and deployment of thematic international virtual research laboratory focused on interdisciplinary environmental studies. VRE under development will comprise best features and functionality of earlier developed information and computing system CLIMATE (http://climate.scert.ru/), which is widely used in Northern Eurasia environment studies. The Project includes several major directions of research listed below. 1. Preparation of geo-referenced data sets, describing the dynamics of the current and possible future climate and environmental changes in detail. 2. Improvement of methods of analysis of climate change. 3. Enhancing the functionality of the VRE prototype in order to create a convenient and reliable tool for the study of regional social, economic and political consequences of climate change. 4. Using the output of the first three tasks, compilation of the VRE prototype, its validation, preparation of applicable detailed description of

  2. STRATEGIC APPROACHES TO CHANGES OF ENVIRONMENT\\ OF SPORTS ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Nebojša Maksimović

    2006-06-01

    Full Text Available Determining acceptable strategic goals requires analysis of the position of a sports organization within the sport world and wider business environment. A range of trends may affect development prospects and business activities of an organization. There are possibilities of population fluctuation (e.g. purchase power of winter sports practitioners, trends of economy, technological development, and legislation (e.g. prohibition of tobacco and alcohol advertisements, or activities of special interest groups (e.g. development of violence in sport. After clarifying its mission and goals, management of a sports organization reveals that some factors are important, while series of others are not

  3. Acoustic integrated extinction

    OpenAIRE

    Norris, Andrew N.

    2015-01-01

    The integrated extinction (IE) is defined as the integral of the scattering cross section as a function of wavelength. Sohl et al. (2007 J. Acoust. Soc. Am. 122, 3206–3210. (doi:10.1121/1.2801546)) derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here, we der...

  4. Mass extinctions of Earth

    International Nuclear Information System (INIS)

    Fernandez, B.; Fernandez, P.; Pereira, B.

    2015-01-01

    Throughout the history of our planet, there have been global phenomena which have led to the disappearance of a large number of species: It is what is known as mass or massive extinctions. This article will make a tour of these large events, from the most remote antiquity to the present day. Today we find ourselves immersed in a process unprecedented since we are eyewitnesses and, more important still, an active part in the decision-making process to try to mitigate their effects. (Author)

  5. Mass extinctions and supernova explosions

    OpenAIRE

    Korschinek, Gunther

    2016-01-01

    A nearby supernova (SN) explosion could have negatively influenced life on Earth, maybe even been responsible for mass extinctions. Mass extinction poses a significant extinction of numerous species on Earth, as recorded in the paleontologic, paleoclimatic, and geological record of our planet. Depending on the distance between the Sun and the SN, different types of threats have to be considered, such as ozone depletion on Earth, causing increased exposure to the Sun's ultraviolet radiation, o...

  6. Extinction of H II regions

    International Nuclear Information System (INIS)

    Israel, F.P.; Kennicutt, R.C.

    1980-01-01

    Visual extinction of H II regions in nine nearby galaxies as derived from the ratio of the radio continuum emission to H-alpha emission is systematically larger than visual extinction deduced from the Balmer lines alone, if one assumes a value Av/E(B-V) 3. An optically-limited sample of about 30 extragalactic H II regions has a mean extinction of 1.7 m in the visual while about 1.2 m is not seen in the reddening of the Balmer lines. Both reddening and extinction decreases with increasing galactic radius, at least for M33 and M101

  7. A reconciliation of extinction theories

    International Nuclear Information System (INIS)

    Sabine, T.M.

    1988-01-01

    The differences between previous theoretical treatments of extinction based on the Darwin intensity equations arise because of the different functional form chosen for the coupling constant σ. When the same function is used these theories make closely similar predictions. It is shown that a limiting condition on integrated intensity as the crystal size increases puts restrictions on the functions which may be used. A Lorentzian or Fresnellian function can be used for primary extinction while secondary extinction requires a Gaussian, rectangular or triangular function. An analytical expression is given for the variation in the value of the extinction factor with scattering angle. (orig.)

  8. Effect of climatic change on surface environments in the typical region of Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The town of Agura,a typical region in Horqin Sandy Land,was selected as the study area in this paper.Using 12 remote sensing images and climatic data from the past 20 years,the effects of climate change on surface environments were analyzed.The impact indices of climatic factors,along with their corresponding ranks,were used to characterize the responses of different types of surface environments to climate change.Results show that in the past 20 years,the surface environments of the study area have been deteriorating.Furthermore,there is a positive relationship between the changes in surface environments and those in climatic factors.Various climatic factors influence surface environments in different ways and at different levels.The most sensitive factor is relative humidity,followed by precipitation and evaporation.Overall,moisture is the key factor that affects the changes in surface environments of arid and semi-arid areas.

  9. Evolution of opercle shape in cichlid fishes from Lake Tanganyika - adaptive trait interactions in extant and extinct species flocks.

    Science.gov (United States)

    Wilson, Laura A B; Colombo, Marco; Sánchez-Villagra, Marcelo R; Salzburger, Walter

    2015-11-20

    Phenotype-environment correlations and the evolution of trait interactions in adaptive radiations have been widely studied to gain insight into the dynamics underpinning rapid species diversification. In this study we explore the phenotype-environment correlation and evolution of operculum shape in cichlid fishes using an outline-based geometric morphometric approach combined with stable isotope indicators of macrohabitat and trophic niche. We then apply our method to a sample of extinct saurichthyid fishes, a highly diverse and near globally distributed group of actinopterygians occurring throughout the Triassic, to assess the utility of extant data to inform our understanding of ecomorphological evolution in extinct species flocks. A series of comparative methods were used to analyze shape data for 54 extant species of cichlids (N = 416), and 6 extinct species of saurichthyids (N = 44). Results provide evidence for a relationship between operculum shape and feeding ecology, a concentration in shape evolution towards present along with evidence for convergence in form, and significant correlation between the major axes of shape change and measures of gut length and body elongation. The operculum is one of few features that can be compared in extant and extinct groups, enabling reconstruction of phenotype-environment interactions and modes of evolutionary diversification in deep time.

  10. Climatic Change and the Future of the Human Environment.

    Science.gov (United States)

    Kotlyakov, Vladimir M.

    1996-01-01

    Evaluates the latest glaciological and oceanological data and demonstrates a strict correlation between global changes of temperature and gas composition of the atmosphere over the last climatic cycle. Concludes that global warming may not create an environmental crisis but will alter drastically the life people lead. (MJP)

  11. Colloquium paper: are we in the midst of the sixth mass extinction? A view from the world of amphibians.

    Science.gov (United States)

    Wake, David B; Vredenburg, Vance T

    2008-08-12

    Many scientists argue that we are either entering or in the midst of the sixth great mass extinction. Intense human pressure, both direct and indirect, is having profound effects on natural environments. The amphibians--frogs, salamanders, and caecilians--may be the only major group currently at risk globally. A detailed worldwide assessment and subsequent updates show that one-third or more of the 6,300 species are threatened with extinction. This trend is likely to accelerate because most amphibians occur in the tropics and have small geographic ranges that make them susceptible to extinction. The increasing pressure from habitat destruction and climate change is likely to have major impacts on narrowly adapted and distributed species. We show that salamanders on tropical mountains are particularly at risk. A new and significant threat to amphibians is a virulent, emerging infectious disease, chytridiomycosis, which appears to be globally distributed, and its effects may be exacerbated by global warming. This disease, which is caused by a fungal pathogen and implicated in serious declines and extinctions of >200 species of amphibians, poses the greatest threat to biodiversity of any known disease. Our data for frogs in the Sierra Nevada of California show that the fungus is having a devastating impact on native species, already weakened by the effects of pollution and introduced predators. A general message from amphibians is that we may have little time to stave off a potential mass extinction.

  12. Are we in the midst of the sixth mass extinction? A view from the world of amphibians

    Science.gov (United States)

    Wake, David B.; Vredenburg, Vance T.

    2008-01-01

    Many scientists argue that we are either entering or in the midst of the sixth great mass extinction. Intense human pressure, both direct and indirect, is having profound effects on natural environments. The amphibians—frogs, salamanders, and caecilians—may be the only major group currently at risk globally. A detailed worldwide assessment and subsequent updates show that one-third or more of the 6,300 species are threatened with extinction. This trend is likely to accelerate because most amphibians occur in the tropics and have small geographic ranges that make them susceptible to extinction. The increasing pressure from habitat destruction and climate change is likely to have major impacts on narrowly adapted and distributed species. We show that salamanders on tropical mountains are particularly at risk. A new and significant threat to amphibians is a virulent, emerging infectious disease, chytridiomycosis, which appears to be globally distributed, and its effects may be exacerbated by global warming. This disease, which is caused by a fungal pathogen and implicated in serious declines and extinctions of >200 species of amphibians, poses the greatest threat to biodiversity of any known disease. Our data for frogs in the Sierra Nevada of California show that the fungus is having a devastating impact on native species, already weakened by the effects of pollution and introduced predators. A general message from amphibians is that we may have little time to stave off a potential mass extinction. PMID:18695221

  13. Evidence for local and global redox conditions at an Early Ordovician (Tremadocian) mass extinction

    Science.gov (United States)

    Edwards, Cole T.; Fike, David A.; Saltzman, Matthew R.; Lu, Wanyi; Lu, Zunli

    2018-01-01

    Profound changes in environmental conditions, particularly atmospheric oxygen levels, are thought to be important drivers of several major biotic events (e.g. mass extinctions and diversifications). The early Paleozoic represents a key interval in the oxygenation of the ocean-atmosphere system and evolution of the biosphere. Global proxies (e.g. carbon (δ13C) and sulfur (δ34S) isotopes) are used to diagnose potential changes in oxygenation and infer causes of environmental change and biotic turnover. The Cambrian-Ordovician contains several trilobite extinctions (some are apparently local, but others are globally correlative) that are attributed to anoxia based on coeval positive δ13C and δ34S excursions. These extinction and excursion events have yet to be coupled with more recently developed proxies thought to be more reflective of local redox conditions in the water column (e.g. I/Ca) to confirm whether these extinctions were associated with oxygen crises over a regional or global scale. Here we examine an Early Ordovician (Tremadocian Stage) extinction event previously interpreted to reflect a continuation of recurrent early Paleozoic anoxic events that expanded into nearshore environments. δ13C, δ34S, and I/Ca trends were measured from three sections in the Great Basin region to test whether I/Ca trends support the notion that anoxia was locally present in the water column along the Laurentian margin. Evidence for anoxia is based on coincident, but not always synchronous, positive δ13C and δ34S excursions (mainly from carbonate-associated sulfate and less so from pyrite data), a 30% extinction of standing generic diversity, and near-zero I/Ca values. Although evidence for local water column anoxia from the I/Ca proxy broadly agrees with intervals of global anoxia inferred from δ13C and δ34S trends, a more complex picture is evident where spatially and temporally variable local trends are superimposed on time-averaged global trends. Stratigraphic

  14. Climate change, marine environments, and the US Endangered species act.

    Science.gov (United States)

    Seney, Erin E; Rowland, Melanie J; Lowery, Ruth Ann; Griffis, Roger B; McClure, Michelle M

    2013-12-01

    Climate change is expected to be a top driver of global biodiversity loss in the 21st century. It poses new challenges to conserving and managing imperiled species, particularly in marine and estuarine ecosystems. The use of climate-related science in statutorily driven species management, such as under the U.S. Endangered Species Act (ESA), is in its early stages. This article provides an overview of ESA processes, with emphasis on the mandate to the National Marine Fisheries Service (NMFS) to manage listed marine, estuarine, and anadromous species. Although the ESA is specific to the United States, its requirements are broadly relevant to conservation planning. Under the ESA, species, subspecies, and "distinct population segments" may be listed as either endangered or threatened, and taking of most listed species (harassing, harming, pursuing, wounding, killing, or capturing) is prohibited unless specifically authorized via a case-by-case permit process. Government agencies, in addition to avoiding take, must ensure that actions they fund, authorize, or conduct are not likely to jeopardize a listed species' continued existence or adversely affect designated critical habitat. Decisions for which climate change is likely to be a key factor include: determining whether a species should be listed under the ESA, designating critical habitat areas, developing species recovery plans, and predicting whether effects of proposed human activities will be compatible with ESA-listed species' survival and recovery. Scientific analyses that underlie these critical conservation decisions include risk assessment, long-term recovery planning, defining environmental baselines, predicting distribution, and defining appropriate temporal and spatial scales. Although specific guidance is still evolving, it is clear that the unprecedented changes in global ecosystems brought about by climate change necessitate new information and approaches to conservation of imperiled species. El

  15. HESS Opinions: Hydrologic predictions in a changing environment: behavioral modeling

    Directory of Open Access Journals (Sweden)

    S. J. Schymanski

    2011-02-01

    Full Text Available Most hydrological models are valid at most only in a few places and cannot be reasonably transferred to other places or to far distant time periods. Transfer in space is difficult because the models are conditioned on past observations at particular places to define parameter values and unobservable processes that are needed to fully characterize the structure and functioning of the landscape. Transfer in time has to deal with the likely temporal changes to both parameters and processes under future changed conditions. This remains an important obstacle to addressing some of the most urgent prediction questions in hydrology, such as prediction in ungauged basins and prediction under global change. In this paper, we propose a new approach to catchment hydrological modeling, based on universal principles that do not change in time and that remain valid across many places. The key to this framework, which we call behavioral modeling, is to assume that there are universal and time-invariant organizing principles that can be used to identify the most appropriate model structure (including parameter values and responses for a given ecosystem at a given moment in time. These organizing principles may be derived from fundamental physical or biological laws, or from empirical laws that have been demonstrated to be time-invariant and to hold at many places and scales. Much fundamental research remains to be undertaken to help discover these organizing principles on the basis of exploration of observed patterns of landscape structure and hydrological behavior and their interpretation as legacy effects of past co-evolution of climate, soils, topography, vegetation and humans. Our hope is that the new behavioral modeling framework will be a step forward towards a new vision for hydrology where models are capable of more confidently predicting the behavior of catchments beyond what has been observed or experienced before.

  16. Can we avoid the Sixth Mass Extinction? Setting today's extinction crisis in the context of the Big Five

    Science.gov (United States)

    Barnosky, A. D.

    2012-12-01

    While the ultimate extinction driver now—Homo sapiens—is unique with respect to the drivers of past extinctions, comparison of parallel neontological and paleontological information helps calibrate how far the so-called Sixth Mass Extinction has progressed and whether it is inevitable. Such comparisons document that rates of extinction today are approaching or exceeding those that characterized the Big Five Mass Extinctions. Continuation of present extinction rates for vertebrates, for example, would result in 75% species loss—the minimum benchmark exhibited in the Big Five extinctions—within 3 to 22 centuries, assuming constant rates of loss and no threshold effects. Preceding and during each of the Big Five, the global ecosystem experienced major changes in climate, atmospheric chemisty, and ocean chemistry—not unlike what is being observed presently. Nevertheless, only 1-2% of well-assessed modern species have been lost over the past five centuries, still far below what characterized past mass extinctions in the strict paleontological sense. For mammals, adding in the end-Pleistocene species that died out would increase the species-loss percentage by some 5%. If threatened vertebrate species were to actually go extinct, losses would rise to between 14 and 40%, depending on the group. Such observations highlight that, although many species have already had their populations drastically reduced to near-critical levels, the Sixth Mass Extinction has not yet progressed to the point where it is unavoidable. Put another way, the vast majority of species that have occupied the world in concert with Homo sapiens are still alive and are possible to save. That task, however, will require slowing the abnormally high extinction rates that are now in progress, which in turn requires unified efforts to cap human population growth, decrease the average human footprint, reduce fossil fuel use while simultaneously increasing clean energy technologies, integrate

  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. Permo-Triassic vertebrate extinctions: A program

    Science.gov (United States)

    Olson, E. C.

    1988-01-01

    Since the time of the Authors' study on this subject, a great deal of new information has become available. Concepts of the nature of extinctions have changed materially. The Authors' conclusion that a catastrophic event was not responsible for the extinction of vertebrates has modified to the extent that hypotheses involving either the impact of a massive extra-terrestrial body or volcanism provide plausible but not currently fully testable hypotheses. Stated changes resulted in a rapid decrease in organic diversity, as the ratio of origins of taxa to extinctions shifted from strongly positive to negative, with momentary equilibrium being reached at about the Permo-Triassic boundary. The proximate causes of the changes in the terrestrial biota appear to lie in two primary factors: (1) strong climatic changes (global mean temperatures, temperature ranges, humidity) and (2) susceptibility of the dominant vertebrates (large dicynodonts) and the glossopteris flora to disruption of the equlibrium of the world ecosystem. The following proximate causes have been proposed: (1) rhythmic fluctuations in solar radiation, (2) tectonic events as Pangea assembled, altering land-ocean relationships, patterns of wind and water circulation and continental physiography, (3) volcanism, and (4) changes subsequent to impacts of one or more massive extra terrestrial objects, bodies or comets. These hypotheses are discussed.

  19. Agricultural nutrient loadings to the freshwater environment: the role of climate change and socioeconomic change

    Science.gov (United States)

    Xie, Hua; Ringler, Claudia

    2017-10-01

    Human activities, in particular agricultural production, interfere with natural cycles of nutrient elements, nitrogen (N) and phosphorus (P), leading to growing concerns about water quality degradation related to excessive nutrient loadings. Increases in agricultural production in response to population growth and wealth generation further increase risks associated with nutrient pollution. This paper presents results from projections of nutrient exports from global agricultural crop and pasture systems to the water environment generated using a process-based modeling approach. Brazil, China, India and the United States account for more than half of estimated global N and P loadings in the base year. Each country boasts large agriculture centers where high calculated loading values are found. Rapid growth in global agricultural nutrient loadings is projected. Growth of agricultural pollution loading is fastest in the group of low-income developing countries and loading growth rates also vary substantially with climate change scenario. Counter measures need to be taken to address the environmental risks associated with the projected rapid increase of agricultural nutrient loadings.

  20. Breeding blueberries for a changing global environment: a review

    Science.gov (United States)

    Lobos, Gustavo A.; Hancock, James F.

    2015-01-01

    Today, blueberries are recognized worldwide as one of the foremost health foods, becoming one of the crops with the highest productive and commercial projections. Over the last 100 years, the geographical area where highbush blueberries are grown has extended dramatically into hotter and drier environments. The expansion of highbush blueberry growing into warmer regions will be challenged in the future by increases in average global temperature and extreme fluctuations in temperature and rainfall patterns. Considerable genetic variability exists within the blueberry gene pool that breeders can use to meet these challenges, but traditional selection techniques can be slow and inefficient and the precise adaptations of genotypes often remain hidden. Marker assisted breeding (MAB) and phenomics could aid greatly in identifying those individuals carrying adventitious traits, increasing selection efficiency and shortening the rate of cultivar release. While phenomics have begun to be used in the breeding of grain crops in the last 10 years, their use in fruit breeding programs it is almost non-existent. PMID:26483803

  1. Breeding blueberries for a changing global environment: a review

    Directory of Open Access Journals (Sweden)

    Gustavo A. Lobos

    2015-09-01

    Full Text Available Today, blueberries are recognized worldwide as one of the foremost health foods, becoming one of the crops with the highest productive and commercial projections. Over the last hundred years, the geographical area where highbush blueberries are grown has extended dramatically into hotter and drier environments. The expansion of highbush blueberry growing into warmer regions will be challenged in the future by increases in average global temperature and extreme fluctuations in temperature and rainfall patterns. Considerable genetic variability exists within the blueberry gene pool that breeders can use to meet these challenges, but traditional selection techniques can be slow and inefficient and the precise adaptations of genotypes often remain hidden. Marker assisted breeding (MAB and phenomics could aid greatly in identifying those individuals carrying adventitious traits, increasing selection efficiency and shortening the rate of cultivar release. While phenomics have begun to be used in the breeding of grain crops in the last 10 years, their use in fruit breeding programs it is almost non-existent.

  2. Exploring the changing learning environment of the gross anatomy lab.

    Science.gov (United States)

    Hopkins, Robin; Regehr, Glenn; Wilson, Timothy D

    2011-07-01

    The objective of this study was to assess the impact of virtual models and prosected specimens in the context of the gross anatomy lab. In 2009, student volunteers from an undergraduate anatomy class were randomly assigned to study groups in one of three learning conditions. All groups studied the muscles of mastication and completed identical learning objectives during a 45-minute lab. All groups were provided with two reference atlases. Groups were distinguished by the type of primary tools they were provided: gross prosections, three-dimensional stereoscopic computer model, or both resources. The facilitator kept observational field notes. A prepost multiple-choice knowledge test was administered to evaluate students' learning. No significant effect of the laboratory models was demonstrated between groups on the prepost assessment of knowledge. Recurring observations included students' tendency to revert to individual memorization prior to the posttest, rotation of models to match views in the provided atlas, and dissemination of groups into smaller working units. The use of virtual lab resources seemed to influence the social context and learning environment of the anatomy lab. As computer-based learning methods are implemented and studied, they must be evaluated beyond their impact on knowledge gain to consider the effect technology has on students' social development.

  3. Climate warming drives local extinction: Evidence from observation and experimentation

    Science.gov (United States)

    Panetta, Anne Marie; Stanton, Maureen L.; Harte, John

    2018-01-01

    Despite increasing concern about elevated extinction risk as global temperatures rise, it is difficult to confirm causal links between climate change and extinction. By coupling 25 years of in situ climate manipulation with experimental seed introductions and both historical and current plant surveys, we identify causal, mechanistic links between climate change and the local extinction of a widespread mountain plant (Androsace septentrionalis). Climate warming causes precipitous declines in population size by reducing fecundity and survival across multiple life stages. Climate warming also purges belowground seed banks, limiting the potential for the future recovery of at-risk populations under ameliorated conditions. Bolstered by previous reports of plant community shifts in this experiment and in other habitats, our findings not only support the hypothesis that climate change can drive local extinction but also foreshadow potentially widespread species losses in subalpine meadows as climate warming continues. PMID:29507884

  4. Climate warming drives local extinction: Evidence from observation and experimentation.

    Science.gov (United States)

    Panetta, Anne Marie; Stanton, Maureen L; Harte, John

    2018-02-01

    Despite increasing concern about elevated extinction risk as global temperatures rise, it is difficult to confirm causal links between climate change and extinction. By coupling 25 years of in situ climate manipulation with experimental seed introductions and both historical and current plant surveys, we identify causal, mechanistic links between climate change and the local extinction of a widespread mountain plant ( Androsace septentrionalis ). Climate warming causes precipitous declines in population size by reducing fecundity and survival across multiple life stages. Climate warming also purges belowground seed banks, limiting the potential for the future recovery of at-risk populations under ameliorated conditions. Bolstered by previous reports of plant community shifts in this experiment and in other habitats, our findings not only support the hypothesis that climate change can drive local extinction but also foreshadow potentially widespread species losses in subalpine meadows as climate warming continues.

  5. Change and Innovation Leadership in an Industrial Digital Environment

    Directory of Open Access Journals (Sweden)

    Steude Dietrich H.

    2017-12-01

    Full Text Available With the high pace of digital innovation processes the risk of digital disruption increases for industrial companies. However, the progress in industrial digitalization accelerates the decision processes and relieves management from routine work. It gives room for creative management challenges like change and innovation processes. Team-oriented methods like Design Thinking are becoming a crucial part of the innovation culture. Industrial leadership must find current ways that are linked to creativity and to a coordinated human interaction. The article ties together the relevant literature and innovative ideas of digital tools, agile methodology and consequences for a flexible organizational structure.

  6. A Comment on the environment and directed technical change

    Energy Technology Data Exchange (ETDEWEB)

    Greaker, Mads; Heggedal, Tom-Reiel

    2012-07-01

    The major claim in Acemoglu, Aghion, Bursztyn and Hemous (2012) (AABH) is that subsidies for research and development of clean technologies are more important than carbon taxes when dealing with climate change. However, they – unconventionally – assume that a patent only lasts for one period. In this note we introduce long-lived patents into the AABH model. This makes the role of a research subsidy for clean technologies in AABH far less crucial and reestablishes the role of the carbon tax. This is good news as it is far easier to tax emissions than to pick the right technologies to subsidize.(Author)

  7. On the world's ice ages and changing environments

    International Nuclear Information System (INIS)

    Eronen, M.; Olander, H.

    1990-07-01

    All known ice ages during the earth's history are reviewed. The oldest glaciation occurred around 2.3 billion years ago, followed by a series of large glaciations 950-650, 450-430 and 310-270 million years ago. Continental drift played a major role in these long-term climatic changes. The present Quaternary ice age actually began 17 million years ago, when a large ice mass grew over Antarctica. A detailed account is given of the climatic fluctuations during the Quaternary period (over 2.5 million years). Different stratigraphic records, and the relationship of climatic variations to orbital forcing are discussed. Large environmental changes took place in the course of the climate oscillations. Large ice sheets waxed and waned, global sea-levels fluctuated, forests disappeared from many regions during cold times and advanced during favourable times. The ice masses depressed the earth's crust markedly, and this then rose rapidly when the ice melted. The extent of glacial erosion is also discussed. Finally the postglacial climatic history of the earth is described and the consequences of the possible greenhouse effect are considered.(orig.)

  8. Global extinction in spiral galaxies

    NARCIS (Netherlands)

    Tully, RB; Pierce, MJ; Saunders, W; Verheijen, MAW; Witchalls, PL

    Magnitude-limited samples of spiral galaxies drawn from the Ursa Major and Pisces Clusters are used to determine their extinction properties as a function of inclination. Imaging photometry is available for 87 spirals in the B, R, I, and K' bands. Extinction causes systematic scatter in

  9. Evolution: Postponing Extinction by Polyandry

    OpenAIRE

    Wade, Michael J.

    2010-01-01

    Sex-ratio meiotic drive occurs when males produce a predominance of X-chromosome bearing sperm and an inordinate number of daughters. A driving X causes highly female-biased sex ratios and the risk of extinction. Polyandry can rescue a population from extinction.

  10. Optimising Extinction of Conditioned Disgust

    NARCIS (Netherlands)

    Bosman, Renske C.; Borg, Charmaine; de Jong, Peter J.

    2016-01-01

    Maladaptive disgust responses are tenacious and resistant to exposure-based interventions. In a similar vein, laboratory studies have shown that conditioned disgust is relatively insensitive to Conditioned Stimulus (CS)-only extinction procedures. The relatively strong resistance to extinction might

  11. Change in ocean subsurface environment to suppress tropical cyclone intensification under global warming

    Science.gov (United States)

    Huang, Ping; Lin, I. -I; Chou, Chia; Huang, Rong-Hui

    2015-01-01

    Tropical cyclones (TCs) are hazardous natural disasters. Because TC intensification is significantly controlled by atmosphere and ocean environments, changes in these environments may cause changes in TC intensity. Changes in surface and subsurface ocean conditions can both influence a TC's intensification. Regarding global warming, minimal exploration of the subsurface ocean has been undertaken. Here we investigate future subsurface ocean environment changes projected by 22 state-of-the-art climate models and suggest a suppressive effect of subsurface oceans on the intensification of future TCs. Under global warming, the subsurface vertical temperature profile can be sharpened in important TC regions, which may contribute to a stronger ocean coupling (cooling) effect during the intensification of future TCs. Regarding a TC, future subsurface ocean environments may be more suppressive than the existing subsurface ocean environments. This suppressive effect is not spatially uniform and may be weak in certain local areas. PMID:25982028

  12. Diversity changes of microbial communities into hospital surface environments.

    Science.gov (United States)

    Yano, Rika; Shimoda, Tomoko; Watanabe, Reina; Kuroki, Yasutoshi; Okubo, Torahiko; Nakamura, Shinji; Matsuo, Junji; Yoshimura, Sadako; Yamaguchi, Hiroyuki

    2017-07-01

    Previous works have demonstrated considerable variability in hospital cleanliness in Japan, suggesting that contamination is driven by factors that are currently poorly controlled. We undertook 16S rRNA sequence analysis to study population structures of hospital environmental microbiomes to see which factor(s) impacted contamination. One hundred forty-four samples were collected from surfaces of three hospitals with distinct sizes ("A": >500 beds, "B": 100-500 beds, "C": diversity changes of hospital environmental microbiomes with a skewed population, presumably by medical staff pushing NWs or sinks shared by patients or visitors. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Adaptive wetland management in an uncertain and changing arid environment

    Directory of Open Access Journals (Sweden)

    Rebekah Downard

    2014-06-01

    Full Text Available Wetlands in the arid western United States provide rare and critical migratory bird habitat and constitute a critical nexus within larger social-ecological systems (SES where multiple changing land-use and water-use patterns meet. The Bear River Migratory Bird Refuge in Utah, USA, presents a case study of the ways that wetland managers have created adaptive management strategies that are responsive to the social and hydrological conditions of the agriculture-dominated SES within which they are located. Managers have acquired water rights and constructed infrastructure while cultivating collaborative relationships with other water users to increase the adaptive capacity of the region and decrease conflict. Historically, water management involved diversion and impoundment of water within wetland units timed around patterns of agricultural water needs. In the last 20 years, managers have learned from flood and drought events and developed a long-term adaptive management plan that specifies alternative management actions managers can choose each year based on habitat needs and projected water supply. Each alternative includes habitat goals and target wetland water depth. However, wetland management adapted to agricultural return-flow availability may prove insufficient as population growth and climate change alter patterns of land and water use. Future management will likely depend more on negotiation, collaboration, and learning from social developments within the SES than strictly focusing on water management within refuge boundaries. To face this problem, managers have worked to be included in negotiations with regional water users, a strategy that may prove instructive for other wetland managers in agriculture-dominated watersheds.

  14. Extinction of Harrington's mountain goat

    International Nuclear Information System (INIS)

    Mead, J.I.; Martin, P.S.; Euler, R.C.; Long, A.; Jull, A.J.T.; Toolin, L.J.; Donahue, D.J.; Linick, T.W.

    1986-01-01

    Keratinous horn sheaths of the extinct Harrington's mountain goat, Oreamnos harringtoni, were recovered at or near the surface of dry caves of the Grand Canyon, Arizona. Twenty-three separate specimens from two caves were dated nondestructively by the tandem accelerator mass spectrometer (TAMS). Both the TAMS and the conventional dates indicate that Harrington's mountain goat occupied the Grand Canyon for at least 19,000 years prior to becoming extinct by 11,160 +/- 125 radiocarbon years before present. The youngest average radiocarbon dates on Shasta ground sloths, Nothrotheriops shastensis, from the region are not significantly younger than those on extinct mountain goats. Rather than sequential extinction with Harrington's mountain goat disappearing from the Grand Canyon before the ground sloths, as one might predict in view of evidence of climatic warming at the time, the losses were concurrent. Both extinctions coincide with the regional arrival of Clovis hunters

  15. Extinction of metal fires

    International Nuclear Information System (INIS)

    Mellottee, H.

    1977-01-01

    The main points of a large bibliography on liquid and solid metal fires are set out. The various methods used to fight these fires are presented; covering by powders is specially emphasized. Since this method has promising results, the various possible techniques, extinction by cooling the metal, by blanketing, by formation of a continuous insulating layer (by fusion or pyrolysis of a powder) or by a surface reaction between powder and metal are studied. The conditions of conservation and use of powders are outlined, then the various powders are described: inert powders, powders undergoing a physical transformation (fusion or vitrification of an organic compound, fusion of eutectic inorganic mixtures), multiple effect powders. Precise examples are quoted [fr

  16. Drought early warning and risk management in a changing environment

    Science.gov (United States)

    Pulwarty, R. S.

    2011-12-01

    Drought has long been recognized as falling into the category of incremental but long-term and cumulative environmental changes, also termed slow-onset or creeping events. These event types would include: air and water quality decline, desertification processes, deforestation and forest fragmentation, loss of biodiversity and habitats, and nitrogen overloading, among others. Climate scientists continue to struggle with recognizing the onset of drought and scientists and policy makers continue to debate the basis (i.e., criteria) for declaring an end to a drought. Risk-based management approaches to drought planning at the national and regional levels have been recommended repeatedly over the years but their prototyping, testing and operational implementation have been limited. This presentation will outline two avenues for disaster risk reduction in the context of drought (1) integrated early warning information systems, and (2) linking disaster risk reduction to climate change adaptation strategies. Adaptation involves not only using operational facilities and infrastructure to cope with the immediate problems but also leaving slack or reserve for coping with multiple stress problems that produce extreme impacts and surprise. Increasing the 'anticipatability' of an event, involves both monitoring of key indicators from appropriate baseline data, and observing early warning signs that assumptions in risk management plans are failing and critical transitions are occurring. Illustrative cases will be drawn from the IPCC Special Report on Managing the Risks of Extreme Events and Disasters (2011), the UN Global Assessment of Disaster Risk Reduction (2011) and implementation activities in which the author has been engaged. Most drought early warning systems have tended to focus on the development and use of physical system indicators and forecasts of trends and thresholds. We show that successful early warning systems that meet expectations of risk management also have

  17. Measuring Extinction with ALE

    Science.gov (United States)

    Zimmer, Peter C.; McGraw, J. T.; Gimmestad, G. G.; Roberts, D.; Stewart, J.; Smith, J.; Fitch, J.

    2007-12-01

    ALE (Astronomical LIDAR for Extinction) is deployed at the University of New Mexico's (UNM) Campus Observatory in Albuquerque, NM. It has begun a year-long testing phase prior deployment at McDonald Observatory in support of the CCD/Transit Instrument II (CTI-II). ALE is designed to produce a high-precision measurement of atmospheric absorption and scattering above the observatory site every ten minutes of every moderately clear night. LIDAR (LIght Detection And Ranging) is the VIS/UV/IR analog of radar, using a laser, telescope and time-gated photodetector instead of a radio transmitter, dish and receiver. In the case of ALE -- an elastic backscatter LIDAR -- 20ns-long, eye-safe laser pulses are launched 2500 times per second from a 0.32m transmitting telescope co-mounted with a 50mm short-range receiver on an alt-az mounted 0.67m long-range receiver. Photons from the laser pulse are scattered and absorbed as the pulse propagates through the atmosphere, a portion of which are scattered into the field of view of the short- and long-range receiver telescopes and detected by a photomultiplier. The properties of a given volume of atmosphere along the LIDAR path are inferred from both the altitude-resolved backscatter signal as well as the attenuation of backscatter signal from altitudes above it. We present ALE profiles from the commissioning phase and demonstrate some of the astronomically interesting atmospheric information that can be gleaned from these data, including, but not limited to, total line-of-sight extinction. This project is funded by NSF Grant 0421087.

  18. Strengthening CERN and particle physics in a changing global environment

    CERN Multimedia

    2016-01-01

    As we welcome Romania as our 22nd Member State in late July, now is a good time to reflect on the geographical enlargement process that was initiated in 2010.   Let me begin by setting the context. CERN operates in an increasingly complex and globalised world. Political and economic developments in the European neighbourhood and well beyond can have an impact on our work – directly or indirectly, in the short term or in a much longer perspective. We need to anticipate that change as far as we can, while also being agile enough to meet the challenges that we do not expect. The UK’s EU referendum on 23 June is a case in point. Because CERN is an organisation founded to facilitate cooperation across borders, Brexit is an uncomfortable truth to many of us. It is, nevertheless, the outcome of the political processes of one of our founding Member States, and is something we must respect. Whatever direction the UK now takes, we will be working with the country’s particle ph...

  19. Understanding Coral's Short-term Adaptive Ability to Changing Environment

    Science.gov (United States)

    Tisthammer, K.; Richmond, R. H.

    2016-02-01

    Corals in Maunalua Bay, Hawaii are under chronic pressures from sedimentation and terrestrial runoffs containing multiple pollutants as a result of large scale urbanization that has taken place in the last 100 years. However, some individual corals thrive despite the prolonged exposure to these environmental stressors, which suggests that these individuals may have adapted to withstand such stressors. A recent survey showed that the lobe coral Porites lobata from the `high-stress' nearshore site had an elevated level of stress ixnduced proteins, compared to those from the `low-stress,' less polluted offshore site. To understand the genetic basis for the observed differential stress responses between the nearshore and offshore P. lobata populations, an analysis of the lineage-scale population genetic structure, as well as a reciprocal transplant experiment were conducted. The result of the genetic analysis revealed a clear genetic differentiation between P. lobata from the nearshore site and the offshore site. Following the 30- day reciprocal transplant experiment, protein expression profiles and other stress-related physiological characteristics were compared between the two populations. The experimental results suggest that the nearshore genotype can cope better with sedimentation/pollutants than the offshore genotype. This indicates that the observed genetic differentiation is due to selection for tolerance to these environmental stressors. Understanding the little-known, linage-scale genetic variation in corals offers a critical insight into their short-term adaptive ability, which is indispensable for protecting corals from impending environmental and climate change. The results of this study also offer a valuable tool for resource managers to make effective decisions on coral reef conservation, such as designing marine protected areas that incorporate and maintain such genetic diversity, and establishing acceptable pollution run-off levels.

  20. Organizational change, psychosocial work environment, and non-disability early retirement

    DEFF Research Database (Denmark)

    Breinegaard, Nina; Jensen, Johan Høy; Bonde, Jens Peter

    2017-01-01

    Objective: This study examines the impact of organizational change and psychosocial work environment on non-disability early retirement among senior public service employees. Methods: In January and February 2011, Danish senior public service employees aged 58–64 years (N=3254) from the Capital...... psychosocial work environment contribute to non-disability early retirement among senior public service employees, measured at work-unit level....... Region of Denmark responded to a survey assessing psychosocial work environment (ie, social capital, organizational justice, and quality of management). Work-unit organizational changes (ie, change of management, merging, demerging, and relocation) were recorded from January 2009 to March 2011. Weekly...

  1. The cricket and the ant : Organizational trade-offs in changing environments

    NARCIS (Netherlands)

    Peli, Gabor; Bruggeman, Jeroen

    2007-01-01

    Organizations face trade-offs when they adopt strategies in changing resource environments. The type of trade-off depends on the type of resource change. This paper offers an organizational trade-off model for quantitative resource changes. We call it the "Cricket and Ant" (CA) model, because the

  2. The Representation of Human-Environment Interactions in Land Change Research and Modelling

    NARCIS (Netherlands)

    Verburg, P.H.; Manfredo, M.J.; Vaske, J.J.; Rechkemmer, A.; Duke, E.A.

    2014-01-01

    Land change is the result of multiple human-environment interactions operating across different scales. Land change research needs to account for processes ranging from global trade of food and energy to the local management of land resources at farm and landscape level. Land change has a pronounced

  3. VLT/X-shooter GRBs: Individual extinction curves of star-forming regions★

    Science.gov (United States)

    Zafar, T.; Watson, D.; Møller, P.; Selsing, J.; Fynbo, J. PU; Schady, P.; Wiersema, K.; Levan, A. J.; Heintz, K. E.; Postigo, A. de Ugarte; D'Elia, V.; Jakobsson, P.; Bolmer, J.; Japelj, J.; Covino, S.; Gomboc, A.; Cano, Z.

    2018-05-01

    The extinction profiles in Gamma-Ray Burst (GRB) afterglow spectral energy distributions (SEDs) are usually described by the Small Magellanic Cloud (SMC)-type extinction curve. In different empirical extinction laws, the total-to-selective extinction, RV, is an important quantity because of its relation to dust grain sizes and compositions. We here analyse a sample of 17 GRBs (0.34a single or broken power-law together with a parametric extinction law is used to model the individual SEDs. We find 10 cases with significant dust, where the derived extinction, AV, ranges from 0.1-1.0 mag. In four of those, the inferred extinction curves are consistent with the SMC curve. The GRB individual extinction curves have a flat RV distribution with an optimal weighted combined value of RV = 2.61 ± 0.08 (for seven broad coverage cases). The `average GRB extinction curve' is similar to, but slightly steeper than the typical SMC, and consistent with the SMC Bar extinction curve at ˜95% confidence level. The resultant steeper extinction curves imply populations of small grains, where large dust grains may be destroyed due to GRB activity. Another possibility could be that young age and/or lower metallicities of GRBs environments are responsible for the steeper curves.

  4. A fundamental role for context in instrumental learning and extinction

    OpenAIRE

    Bouton, Mark E.; Todd, Travis P.

    2014-01-01

    The purpose of this article is to review recent research that has investigated the effects of context change on instrumental (operant) learning. The first part of the article discusses instrumental extinction, in which the strength of a reinforced instrumental behavior declines when reinforcers are withdrawn. The results suggest that extinction of either simple or discriminated operant behavior is relatively specific to the context in which it is learned: As in prior studies of Pavlovian exti...

  5. Seagrasses under threat: Understanding the resilience of temperate seagrass meadows in a changing environment

    NARCIS (Netherlands)

    Soissons, L.M.

    2017-01-01

    Despite being highly valuable ecosystems, seagrass meadows are threatened worldwide, mostly by human activities. In order to preserve seagrass meadows from collapse, we need to better understand their resilience in a changing environment. By means of various

  6. Landscape changes in the environment due to military actions and their epidemic risks

    Directory of Open Access Journals (Sweden)

    Krushelnitsky A.D.

    2016-05-01

    Full Text Available The article considers the influence of the military-ecological and man-caused-anthropogenic factors on the environment state and natural processes. Epidemic risks and consequences resulted from landscapic changes of the environment which arise as a result of war and destruction of ecosystems are described.

  7. Changes in School Competitive Food Environments after a Health Promotion Campaign

    Science.gov (United States)

    Green, Sarah H.; Mallya, Giridhar; Brensinger, Colleen; Tierney, Ann; Glanz, Karen

    2018-01-01

    Background: Schools can reduce student access to competitive foods and influence healthy food choices by improving the school nutrition environment. This study describes changes in competitive nutrition environments in 100 K-8 schools participating in the Philadelphia Campaign for Healthier Schools. Methods: Interviews with school staff were used…

  8. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  9. Genetic sex determination and extinction.

    Science.gov (United States)

    Hedrick, Philip W; Gadau, Jürgen; Page, Robert E

    2006-02-01

    Genetic factors can affect the probability of extinction either by increasing the effect of detrimental variants or by decreasing the potential for future adaptive responses. In a recent paper, Zayed and Packer demonstrate that low variation at a specific locus, the complementary sex determination (csd) locus in Hymenoptera (ants, bees and wasps), can result in a sharply increased probability of extinction. Their findings illustrate situations in which there is a feedback process between decreased genetic variation at the csd locus owing to genetic drift and decreased population growth, resulting in an extreme type of extinction vortex for these ecologically important organisms.

  10. Mathematical modeling environment as a promoter changes traditional conceptions of the math teacher

    Directory of Open Access Journals (Sweden)

    Arthur Gonçalves Machado Junior

    2009-06-01

    Full Text Available The purpose of this paper is to present, through episodes, modifications made by the teacher during the interaction in the research environment, a state public school in the outskirts of Belem. Were analyzed four episodes, in which we see significant changes in his posture classroom. The episodes are meant to highlight these changes, which we believe are the interactions of the characters from the environment, the teacher with the teacher-researcher and it with his students

  11. Pathways to extinction: beyond the error threshold.

    Science.gov (United States)

    Manrubia, Susanna C; Domingo, Esteban; Lázaro, Ester

    2010-06-27

    Since the introduction of the quasispecies and the error catastrophe concepts for molecular evolution by Eigen and their subsequent application to viral populations, increased mutagenesis has become a common strategy to cause the extinction of viral infectivity. Nevertheless, the high complexity of virus populations has shown that viral extinction can occur through several other pathways apart from crossing an error threshold. Increases in the mutation rate enhance the appearance of defective forms and promote the selection of mechanisms that are able to counteract the accelerated appearance of mutations. Current models of viral evolution take into account more realistic scenarios that consider compensatory and lethal mutations, a highly redundant genotype-to-phenotype map, rough fitness landscapes relating phenotype and fitness, and where phenotype is described as a set of interdependent traits. Further, viral populations cannot be understood without specifying the characteristics of the environment where they evolve and adapt. Altogether, it turns out that the pathways through which viral quasispecies go extinct are multiple and diverse.

  12. Resistance to extinction, generalization decrement, and conditioned reinforcement.

    Science.gov (United States)

    Dulaney, Alana E; Bell, Matthew C

    2008-06-01

    This study investigated generalization decrement during an extinction resistance-to-change test for pigeon key pecking using a two-component multiple schedule with equal variable-interval 3-min schedules and different reinforcer amounts (one component presented 2-s access to reinforcement and the other 8s). After establishing baseline responding, subjects were assigned to one of the two extinction conditions: hopper stimuli (hopper and hopper light were activated but no food was available) or Control (inactive hopper and hopper light). Responding in the 8-s component was more resistant to extinction than responding in the 2-s component, the hopper stimuli group was more resistant to extinction compared to the Control group, and an interaction between amount of reinforcement, extinction condition, and session block was present. This finding supports generalization decrement as a factor that influences resistance to extinction. Hopper-time data (the amount of time subjects spent with their heads in the hopper) were compared to resistance-to-change data in an investigation of the role of conditioned reinforcement on resistance to change.

  13. Relationship of extinction to perceptual thresholds for single stimuli.

    Science.gov (United States)

    Meador, K J; Ray, P G; Day, L J; Loring, D W

    2001-04-24

    To demonstrate the effects of target stimulus intensity on extinction to double simultaneous stimuli. Attentional deficits contribute to extinction in patients with brain lesions, but extinction (i.e., masking) can also be produced in healthy subjects. The relationship of extinction to perceptual thresholds for single stimuli remains uncertain. Brief electrical pulses were applied simultaneously to the left and right index fingers of 16 healthy volunteers (8 young and 8 elderly adults) and 4 patients with right brain stroke (RBS). The stimulus to be perceived (i.e., target stimulus) was given at the lowest perceptual threshold to perceive any single stimulus (i.e., Minimal) and at the threshold to perceive 100% of single stimuli. The mask stimulus (i.e., stimulus given to block the target) was applied to the contralateral hand at intensities just below discomfort. Extinction was less for target stimuli at 100% than Minimal threshold for healthy subjects. Extinction of left targets was greater in patients with RBS than elderly control subjects. Left targets were extinguished less than right in healthy subjects. In contrast, the majority of left targets were extinguished in patients with RBS even when right mask intensity was reduced below right 100% threshold for single stimuli. RBS patients had less extinction for right targets despite having greater left mask - threshold difference than control subjects. In patients with RBS, right "targets" at 100% threshold extinguished left "masks" (20%) almost as frequently as left masks extinguished right targets (32%). Subtle changes in target intensity affect extinction in healthy adults. Asymmetries in mask and target intensities (relative to single-stimulus perceptual thresholds) affect extinction in RBS patients less for left targets but more for right targets as compared with control subjects.

  14. MEST- avoid next extinction by a space-time effect

    Science.gov (United States)

    Cao, Dayong

    2013-03-01

    Sun's companion-dark hole seasonal took its dark comets belt and much dark matter to impact near our earth. And some of them probability hit on our earth. So this model kept and triggered periodic mass extinctions on our earth every 25 to 27 million years. After every impaction, many dark comets with very special tilted orbits were arrested and lurked in solar system. When the dark hole-Tyche goes near the solar system again, they will impact near planets. The Tyche, dark comet and Oort Cloud have their space-time center. Because the space-time are frequency and amplitude square of wave. Because the wave (space-time) can make a field, and gas has more wave and fluctuate. So they like dense gas ball and a dark dense field. They can absorb the space-time and wave. So they are ``dark'' like the dark matter which can break genetic codes of our lives by a dark space-time effect. So the upcoming next impaction will cause current ``biodiversity loss.'' The dark matter can change dead plants and animals to coal, oil and natural gas which are used as energy, but break our living environment. According to our experiments, which consciousness can use thought waves remotely to change their systemic model between Electron Clouds and electron holes of P-N Junction and can change output voltages of solar cells by a life information technology and a space-time effect, we hope to find a new method to the orbit of the Tyche to avoid next extinction. (see Dayong Cao, BAPS.2011.APR.K1.17 and BAPS.2012.MAR.P33.14) Support by AEEA

  15. Reconsidering the extinction of ichthyosaurs

    OpenAIRE

    Fischer, Valentin

    2010-01-01

    Despite their extreme adaptation to life in open sea, ichthyosaurs were one of the first major groups of post-Triassic marine reptiles to disappear, at the end of Cenomanian, whereas plesiosaurs, mosasaurs and numerous families of marine crocodiles and sea turtles disappeared during the Cretaceous/Paleocene Extinction Event. It has been proposed that unique biological factors drove ichthyosaurs to extinction, namely a break in the food chain at the level of belemnites or a progressive ecologi...

  16. The Sixth Great Mass Extinction

    Science.gov (United States)

    Wagler, Ron

    2012-01-01

    Five past great mass extinctions have occurred during Earth's history. Humanity is currently in the midst of a sixth, human-induced great mass extinction of plant and animal life (e.g., Alroy 2008; Jackson 2008; Lewis 2006; McDaniel and Borton 2002; Rockstrom et al. 2009; Rohr et al. 2008; Steffen, Crutzen, and McNeill 2007; Thomas et al. 2004;…

  17. Trends in the extinction of carnivores in Madagascar

    Directory of Open Access Journals (Sweden)

    Cartagena–Matos, B.

    2017-02-01

    Full Text Available The extinction of top predators, such as mammalian carnivores can lead to dramatic changes in foodweb structure and ecosystem dynamics. Since all native Malagasy terrestrial mammalian carnivores are endemic, their extinction implies a significant loss of biodiversity in Madagascar. Here we review the literature on Madagascar’s mammalian carnivores, aiming to determine which species are most likely to become extinct in the near future in view of the factors threatening their survival. We scored each factor according to its impact on the species. According to our results, the giant–striped mongoose, Galidictis grandidieri, is the most likely species to next become extinct. This is no surprise because this species is considered one of the rarest carnivores in the world, inhabiting only a small, threatened forest ecosystem. Our results emphasize the need for robust data about each species to help and support decision–makers implement conservation measures.

  18. Ocean anoxia did not cause the Latest Permian Extinction

    Science.gov (United States)

    Proemse, Bernadette C.; Grasby, Stephen E.; Wieser, Michael E.; Mayer, Bernhard; Beauchamp, Benoit

    2014-05-01

    The Latest Permian Extinction (LPE, ~252 million years ago) was a turning point in the history of life on Earth with a loss of ~96% of all marine species and ~70% of all terrestrial species. While, the event undoubtedly shaped the evolution of life its cause remains enigmatic. A leading hypothesis is that the global oceans became depleted in oxygen (anoxia). In order to test this hypothesis we investigated a proxy for marine oxygen levels (molybdenum isotopic composition) in shale across the LPE horizon located on the subtropical northwest margin of Pangea at that time. We studied two sedimentary records in the Sverdrup basin, Canadian High Arctic: Buchanan Lake (eastern Axel Heiberg Island; 79° 26.1'N, 87° 12.6'W), representing a distal deep-water slope environment, and West Blind Fiord (southwest Ellesmere Island; 78° 23.9'N, 85° 57.2'W), representing a deep outer shelf environment (below storm wave base). The molybdenum isotopic composition (δ98/95Mo) of sediments has recently become a powerful tool as a paleo-oceanographic proxy of marine oxygen levels. Sample preparation was carried out in a metal-free clean room facility in the isotope laboratory of the Department of Physics and Astronomy, University of Calgary, Canada, that is supplied by HEPA-filtered air. Molybdenum isotope ratios were determined on a Thermo Scientific multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) with an uncertainty better than ±0.10o for δ98/95Mo values. Results from the Buchanan Lake section show a large shift in δ98/95Mo values from 2.02o to +2.23o at the extinction horizon, consistent with onset of euxinic conditions. In contrast, West Blind Fiord shales, representing the sub-storm wave base shelf environment, show little change in the molybdenum isotopic composition (1.34o to +0.05), indicating ongoing oxic conditions across the LPE (Proemse et al., 2013). Our results suggest that areas of the Pangea continental shelf (North West Pangea) experienced

  19. Opposite effects of fear conditioning and extinction on dendritic spine remodelling.

    Science.gov (United States)

    Lai, Cora Sau Wan; Franke, Thomas F; Gan, Wen-Biao

    2012-02-19

    It is generally believed that fear extinction is a form of new learning that inhibits rather than erases previously acquired fear memories. Although this view has gained much support from behavioural and electrophysiological studies, the hypothesis that extinction causes the partial erasure of fear memories remains viable. Using transcranial two-photon microscopy, we investigated how neural circuits are modified by fear learning and extinction by examining the formation and elimination of postsynaptic dendritic spines of layer-V pyramidal neurons in the mouse frontal association cortex. Here we show that fear conditioning by pairing an auditory cue with a footshock increases the rate of spine elimination. By contrast, fear extinction by repeated presentation of the same auditory cue without a footshock increases the rate of spine formation. The degrees of spine remodelling induced by fear conditioning and extinction strongly correlate with the expression and extinction of conditioned fear responses, respectively. Notably, spine elimination and formation induced by fear conditioning and extinction occur on the same dendritic branches in a cue- and location-specific manner: cue-specific extinction causes formation of dendritic spines within a distance of two micrometres from spines that were eliminated after fear conditioning. Furthermore, reconditioning preferentially induces elimination of dendritic spines that were formed after extinction. Thus, within vastly complex neuronal networks, fear conditioning, extinction and reconditioning lead to opposing changes at the level of individual synapses. These findings also suggest that fear memory traces are partially erased after extinction.

  20. Individual Differences in Behavioural Reaction to a Changing Environment in Mice and Rats

    NARCIS (Netherlands)

    Benus, R.F.; Koolhaas, J.M.; Oortmerssen, G.A. van

    1987-01-01

    Aggressive and non-aggressive male mice differ in their reaction to a changing social environment. In order to investigate if this differentiation holds also for non-social situations male mice are trained in a standard maze task, whereafter a change (extramaze and intramaze, respectively) is

  1. Robust online belief space planning in changing environments: Application to physical mobile robots

    KAUST Repository

    Agha-mohammadi, Ali-akbar; Agarwal, Saurav; Mahadevan, Aditya; Chakravorty, Suman; Tomkins, Daniel; Denny, Jory; Amato, Nancy M.

    2014-01-01

    , such as the discrepancy between computational models and real physical models. In this paper, we propose a dynamic replanning scheme in belief space to address such challenges. Moreover, we present techniques to cope with changes in the environment (e.g., changes

  2. Obesity and the built environment: changes in environmental cues cause energy imbalances.

    Science.gov (United States)

    Cohen, D A

    2008-12-01

    The past 30 years have seen dramatic changes in the food and physical activity environments, both of which contribute to the changes in human behavior that could explain obesity. This paper reviews documented changes in the food environment, changes in the physical activity environment and the mechanisms through which people respond to these environments, often without conscious awareness or control. The most important environmental changes have been increases in food accessibility, food salience and decreases in the cost of food. The increases in food marketing and advertising create food cues that artificially stimulate people to feel hungry. The existence of a metabolic pathway that allows excess energy to be stored as fat suggests that people were designed to overeat. Many internal mechanisms favor neurophysiologic responses to food cues that result in overconsumption. External cues, such as food abundance, food variety and food novelty, cause people to override internal signals of satiety. Other factors, such as conditioning and priming, tie food to other desirable outcomes, and thus increase the frequency that hunger is stimulated by environmental cues. People's natural response to the environmental cues are colored by framing, and judgments are flawed and biased depending on how information is presented. People lack insight into how the food environment affects them, and subsequently are unable to change the factors that are responsible for excessive energy consumption. Understanding the causal pathway for overconsumption will be necessary to interrupt the mechanisms that lead to obesity.

  3. Change: Threat or opportunity for human progress? V. 5. Ecological change: Environment, development and poverty linkages

    International Nuclear Information System (INIS)

    Kirdar, U.

    1992-01-01

    This volume consists of 18 articles that examine the changing ecological balance of the world and its effect on human prosperity. The problems caused by global warning, climate change and environmental degradation will have serious effects in both the short and the long term. Two of the 18 articles fall within INIS scope: these have been indexed separately. Tabs

  4. Change: Threat or opportunity for human progress V. 5. Ecological change: Environment, development and poverty linkages

    Energy Technology Data Exchange (ETDEWEB)

    Kirdar, U [ed.

    1992-01-01

    This volume consists of 18 articles that examine the changing ecological balance of the world and its effect on human prosperity. The problems caused by global warning, climate change and environmental degradation will have serious effects in both the short and the long term. Two of the 18 articles fall within INIS scope: these have been indexed separately. Tabs.

  5. Learning Is Change: Creating an Environment for Sustainable Organizational Change in Continuing and Higher Education

    Science.gov (United States)

    Schultz, Christie

    2014-01-01

    This article explores the ways in which learning itself is a form of organizational change and, as such, supports organizational readiness for change. The study considers a continuing education unit within a major Canadian university that managed to transform its decentralized and independent student records and administration system (student…

  6. The effects of compound stimulus extinction and inhibition of noradrenaline reuptake on the renewal of alcohol seeking

    Science.gov (United States)

    Furlong, T M; Pan, M J; Corbit, L H

    2015-01-01

    Alcohol-related stimuli can trigger relapse of alcohol-seeking behaviors even after extended periods of abstinence. Extinction of such stimuli can reduce their impact on relapse; however, the expression of extinction can be disrupted when testing occurs outside the context where extinction learning took place, an effect termed renewal. Behavioral and pharmacological methods have recently been shown to augment extinction learning; yet, it is not known whether the improved expression of extinction following these treatments remains context-dependent. Here we examined whether two methods, compound–stimulus extinction and treatment with the noradrenaline reuptake inhibitor atomoxetine, would reduce the vulnerability of extinction to a change in context. Following alcohol self-administration, responding was extinguished in a distinct context. After initial extinction, further extinction was given to a target stimulus presented in compound with another alcohol-predictive stimulus intended to augment prediction error (Experiment 1) or after a systemic injection of atomoxetine (1.0 mg kg−1; Experiment 2). A stimulus extinguished as part of a compound elicited less responding than a stimulus receiving equal extinction alone regardless of whether animals were tested in the training or extinction context; however, reliable renewal was not observed in this paradigm. Importantly, atomoxetine enhanced extinction relative to controls even in the presence of a reliable renewal effect. Thus, extinction of alcohol-seeking behavior can be improved by extinguishing multiple alcohol-predictive stimuli or enhancing noradrenaline neurotransmission during extinction training. Importantly, both methods improve extinction even when the context is changed between extinction training and test, and thus could be utilized to enhance the outcome of extinction-based treatments for alcohol-use disorders. PMID:26327688

  7. European research on Climat change impact on human health and environment

    OpenAIRE

    Pogonysheva I. A.; Kuznetsova V. P.; Pogonyshev D. A.; Lunyak I. I.

    2018-01-01

    European countries have accumulated a considerable body of research that proves both direct and indirect influence of climate change on human health. The article analyses “Protecting health in an environment challenged by climate change: European Regional Framework for Action”. The article gives a detailed analysis of the work of European Office of World Health Organisation and The United Nations Economic Commission for Europe related to climate change.

  8. The effect of sexual selection on adaptation and extinction under increasing temperatures.

    Science.gov (United States)

    Parrett, Jonathan M; Knell, Robert J

    2018-04-25

    Strong sexual selection has been reported to both enhance and hinder the adaptive capacity and persistence of populations when exposed to novel environments. Consequently, how sexual selection influences population adaption and persistence under stress remains widely debated. Here, we present two empirical investigations of the fitness consequences of sexual selection on populations of the Indian meal moth, Plodia interpunctella, exposed to stable or gradually increasing temperatures. When faced with increasing temperatures, strong sexual selection was associated with both increased fecundity and offspring survival compared with populations experiencing weak sexual selection, suggesting sexual selection acts to drive adaptive evolution by favouring beneficial alleles. Strong sexual selection did not, however, delay extinction when the temperature became excessively high. By manipulating individuals' mating opportunities during fitness assays, we were able to assess the effect of multiple mating independently from the effect of population-level sexual selection, and found that polyandry has a positive effect on both fecundity and offspring survival under increasing temperatures in those populations evolving with weak sexual selection. Within stable temperatures, there were some benefits from strong sexual selection but these were not consistent across the entire experiment, possibly reflecting changing costs and benefits of sexual selection under stabilizing and directional selection. These results indicate that sexual selection can provide a buffer against climate change and increase adaptation rates within a continuously changing environment. These positive effects of sexual selection may, however, be too small to protect populations and delay extinction when environmental changes are relatively rapid. © 2018 The Author(s).

  9. EXTINCTION LAWS TOWARD STELLAR SOURCES WITHIN A DUSTY CIRCUMSTELLAR MEDIUM AND IMPLICATIONS FOR TYPE IA SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Takashi; Maeda, Keiichi [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Nozawa, Takaya, E-mail: nagao@kusastro.kyoto-u.ac.jp [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2016-06-01

    Many astronomical objects are surrounded by dusty environments. In such dusty objects, multiple scattering processes of photons by circumstellar (CS) dust grains can effectively alter extinction properties. In this paper, we systematically investigate the effects of multiple scattering on extinction laws for steady-emission sources surrounded by the dusty CS medium using a radiation transfer simulation based on the Monte Carlo technique. In particular, we focus on whether and how the extinction properties are affected by properties of CS dust grains by adopting various dust grain models. We confirm that behaviors of the (effective) extinction laws are highly dependent on the properties of CS grains, especially the total-to-selective extinction ratio R{sub V}, which characterizes the extinction law and can be either increased or decreased and compared with the case without multiple scattering. We find that the criterion for this behavior is given by a ratio of albedos in the B and V bands. We also find that either small silicate grains or polycyclic aromatic hydrocarbons are necessary for realizing a low value of R{sub V} as often measured toward SNe Ia if the multiple scattering by CS dust is responsible for their non-standard extinction laws. Using the derived relations between the properties of dust grains and the resulting effective extinction laws, we propose that the extinction laws toward dusty objects could be used to constrain the properties of dust grains in CS environments.

  10. EXTINCTION LAWS TOWARD STELLAR SOURCES WITHIN A DUSTY CIRCUMSTELLAR MEDIUM AND IMPLICATIONS FOR TYPE IA SUPERNOVAE

    International Nuclear Information System (INIS)

    Nagao, Takashi; Maeda, Keiichi; Nozawa, Takaya

    2016-01-01

    Many astronomical objects are surrounded by dusty environments. In such dusty objects, multiple scattering processes of photons by circumstellar (CS) dust grains can effectively alter extinction properties. In this paper, we systematically investigate the effects of multiple scattering on extinction laws for steady-emission sources surrounded by the dusty CS medium using a radiation transfer simulation based on the Monte Carlo technique. In particular, we focus on whether and how the extinction properties are affected by properties of CS dust grains by adopting various dust grain models. We confirm that behaviors of the (effective) extinction laws are highly dependent on the properties of CS grains, especially the total-to-selective extinction ratio R V , which characterizes the extinction law and can be either increased or decreased and compared with the case without multiple scattering. We find that the criterion for this behavior is given by a ratio of albedos in the B and V bands. We also find that either small silicate grains or polycyclic aromatic hydrocarbons are necessary for realizing a low value of R V as often measured toward SNe Ia if the multiple scattering by CS dust is responsible for their non-standard extinction laws. Using the derived relations between the properties of dust grains and the resulting effective extinction laws, we propose that the extinction laws toward dusty objects could be used to constrain the properties of dust grains in CS environments.

  11. Analysis of the evolution of precipitation in the Haihe river basin of China under changing environment

    Science.gov (United States)

    Ding, Xiangyi; Liu, Jiahong; Gong, Jiaguo

    2018-02-01

    Precipitation is one of the important factors of water cycle and main sources of regional water resources. It is of great significance to analyze the evolution of precipitation under changing environment for identifying the evolution law of water resources, thus can provide a scientific reference for the sustainable utilization of water resources and the formulation of related policies and measures. Generally, analysis of the evolution of precipitation consists of three levels: analysis the observed precipitation change based on measured data, explore the possible factors responsible for the precipitation change, and estimate the change trend of precipitation under changing environment. As the political and cultural centre of China, the climatic conditions in the Haihe river basin have greatly changed in recent decades. This study analyses the evolution of precipitation in the basin under changing environment based on observed meteorological data, GCMs and statistical methods. Firstly, based on the observed precipitation data during 1961-2000 at 26 meteorological stations in the basin, the actual precipitation change in the basin is analyzed. Secondly, the observed precipitation change in the basin is attributed using the fingerprint-based attribution method, and the causes of the observed precipitation change is identified. Finally, the change trend of precipitation in the basin under climate change in the future is predicted based on GCMs and a statistical downscaling model. The results indicate that: 1) during 1961-2000, the precipitation in the basin showed a decreasing trend, and the possible mutation time was 1965; 2) natural variability may be the factor responsible for the observed precipitation change in the basin; 3) under climate change in the future, precipitation in the basin will slightly increase by 4.8% comparing with the average, and the extremes will not vary significantly.

  12. Climate change and human disturbance can lead to local extinction of Alpine rock ptarmigan: new insight from the western Italian Alps.

    Directory of Open Access Journals (Sweden)

    Simona Imperio

    Full Text Available Alpine grouses are particularly vulnerable to climate change due to their adaptation to extreme conditions and to their relict distributions in the Alps where global warming has been particularly marked in the last half century. Grouses are also currently threatened by habitat modification and human disturbance, and an assessment of the impact of multiple stressors is needed to predict the fate of Alpine populations of these birds in the next decades. We estimated the effect of climate change and human disturbance on a rock ptarmigan population living in the western Italian Alps by combining an empirical population modelling approach and stochastic simulations of the population dynamics under the a1B climate scenario and two different disturbance scenarios, represented by the development of a ski resort, through 2050.The early appearance of snow-free ground in the previous spring had a favorable effect on the rock ptarmigan population, probably through a higher reproductive success. On the contrary, delayed snowfall in autumn had a negative effect possibly due to a mismatch in time to molt to white winter plumage which increases predation risk. The regional climate model PROTHEUS does not foresee any significant change in snowmelt date in the study area, while the start date of continuous snow cover is expected to be significantly delayed. The net effect in the stochastic projections is a more or less pronounced (depending on the model used decline in the studied population. The addition of extra-mortality due to collision with ski-lift wires led the population to fatal consequences in most projections. Should these results be confirmed by larger studies the conservation of Alpine populations would deserve more attention. To counterbalance the effects of climate change, the reduction of all causes of death should be pursued, through a strict preservation of the habitats in the present area of occurrence.

  13. Climate-driven extinctions shape the phylogenetic structure of temperate tree floras.

    Science.gov (United States)

    Eiserhardt, Wolf L; Borchsenius, Finn; Plum, Christoffer M; Ordonez, Alejandro; Svenning, Jens-Christian

    2015-03-01

    When taxa go extinct, unique evolutionary history is lost. If extinction is selective, and the intrinsic vulnerabilities of taxa show phylogenetic signal, more evolutionary history may be lost than expected under random extinction. Under what conditions this occurs is insufficiently known. We show that late Cenozoic climate change induced phylogenetically selective regional extinction of northern temperate trees because of phylogenetic signal in cold tolerance, leading to significantly and substantially larger than random losses of phylogenetic diversity (PD). The surviving floras in regions that experienced stronger extinction are phylogenetically more clustered, indicating that non-random losses of PD are of increasing concern with increasing extinction severity. Using simulations, we show that a simple threshold model of survival given a physiological trait with phylogenetic signal reproduces our findings. Our results send a strong warning that we may expect future assemblages to be phylogenetically and possibly functionally depauperate if anthropogenic climate change affects taxa similarly. © 2015 John Wiley & Sons Ltd/CNRS.

  14. Introductions do not compensate for functional and phylogenetic losses following extinctions in insular bird assemblages.

    Science.gov (United States)

    Sobral, Fernando L; Lees, Alexander C; Cianciaruso, Marcus V

    2016-09-01

    The ratio of species extinctions to introductions has been comparable for many insular assemblages, suggesting that introductions could have 'compensated' for extinctions. However, the capacity for introduced species to replace ecological roles and evolutionary history lost following extinction is unclear. We investigated changes in bird functional and phylogenetic diversity in the wake of extinctions and introductions across a sample of 32 islands worldwide. We found that extinct and introduced species have comparable functional and phylogenetic alpha diversity. However, this was distributed at different positions in functional space and in the phylogeny, indicating a 'false compensation'. Introduced and extinct species did not have equivalent functional roles nor belong to similar lineages. This makes it unlikely that novel island biotas composed of introduced taxa will be able to maintain ecological roles and represent the evolutionary histories of pre-disturbance assemblages and highlights the importance of evaluating changes in alpha and beta diversity concurrently. © 2016 John Wiley & Sons Ltd/CNRS.

  15. Rural Settlement Development and Environment Carrying Capacity Changes in Progo River Basin

    OpenAIRE

    Su Ritohardoyo; P Priyono

    2016-01-01

    Generally the broader rural settlement the heavier population pressure on agricultural land. It indicates that carrying capacity of the rural environment threatened lower. The spatial distribution of the threat in a river basin is quite important as one of the river basin management inputs. Therefore, this article aims at exposing result of research about influence rural population growth and rural settlement land changes to environment carrying capacity. This research was carried out in the ...

  16. Yoga Therapy: Building a Holding Environment for Somatic and Psyche Change.

    Science.gov (United States)

    McClure, Bud

    2015-01-01

    Drawing on ideas from D.W. Winnicott and the work of Quaker theologian Parker Palmer, this article discusses the concept of a holding environment, its refined understanding in the literature over the years, and how it can be optimally used in yoga therapy. The evidence shows that effectively establishing a holding environment can facilitate both somatic and deep structural change in a client, facilitating healing from primal wounding as well as the potential reconnection to the true self.

  17. Complex Genotype by Environment interactions and changing genetic architectures across thermal environments in the Australian field cricket, Teleogryllus oceanicus

    Directory of Open Access Journals (Sweden)

    Dowling Damian K

    2011-07-01

    Full Text Available Abstract Background Biologists studying adaptation under sexual selection have spent considerable effort assessing the relative importance of two groups of models, which hinge on the idea that females gain indirect benefits via mate discrimination. These are the good genes and genetic compatibility models. Quantitative genetic studies have advanced our understanding of these models by enabling assessment of whether the genetic architectures underlying focal phenotypes are congruent with either model. In this context, good genes models require underlying additive genetic variance, while compatibility models require non-additive variance. Currently, we know very little about how the expression of genotypes comprised of distinct parental haplotypes, or how levels and types of genetic variance underlying key phenotypes, change across environments. Such knowledge is important, however, because genotype-environment interactions can have major implications on the potential for evolutionary responses to selection. Results We used a full diallel breeding design to screen for complex genotype-environment interactions, and genetic architectures underlying key morphological traits, across two thermal environments (the lab standard 27°C, and the cooler 23°C in the Australian field cricket, Teleogryllus oceanicus. In males, complex three-way interactions between sire and dam parental haplotypes and the rearing environment accounted for up to 23 per cent of the scaled phenotypic variance in the traits we measured (body mass, pronotum width and testes mass, and each trait harboured significant additive genetic variance in the standard temperature (27°C only. In females, these three-way interactions were less important, with interactions between the paternal haplotype and rearing environment accounting for about ten per cent of the phenotypic variance (in body mass, pronotum width and ovary mass. Of the female traits measured, only ovary mass for crickets

  18. Species Turnover through Time: Colonization and Extinction Dynamics across Metacommunities.

    Science.gov (United States)

    Nuvoloni, Felipe Micali; Feres, Reinaldo José Fazzio; Gilbert, Benjamin

    2016-06-01

    Island biogeography and metacommunity theory often use equilibrium assumptions to predict local diversity, yet nonequilibrium dynamics are common in nature. In nonequilibrium communities, local diversity fluctuates through time as the relative importance of colonization and extinction change. Here, we test the prevalence and causes of nonequilibrium dynamics in metacommunities of mites associated with rubber trees distributed over large spatial (>1,000 km) and temporal (>30-60 generations) scales in Brazil. We measured colonization and extinction rates to test species turnover and nonequilibrium dynamics over a growing season. Mite metacommunities exhibited nonequilibrium dynamics for most months of the year, and these dynamics tracked climatic conditions. Monthly shifts in temperature of more than 1°C resulted in nonequilibrium dynamics, as did mean temperatures outside of two critical ranges. Nonequilibrium dynamics were caused by a change in colonization with temperature change and changes in both colonization and extinction with absolute temperature. Species turnover showed different trends; high relative humidity increased both colonization and extinction rates, increasing turnover but not nonequilibrium dynamics. Our study illustrates that testing nonequilibrium dynamics can provide new insights into the drivers of colonization, extinction, and diversity fluctuations in metacommunities.

  19. Resurrection of DNA function in vivo from an extinct genome.

    Directory of Open Access Journals (Sweden)

    Andrew J Pask

    2008-05-01

    Full Text Available There is a burgeoning repository of information available from ancient DNA that can be used to understand how genomes have evolved and to determine the genetic features that defined a particular species. To assess the functional consequences of changes to a genome, a variety of methods are needed to examine extinct DNA function. We isolated a transcriptional enhancer element from the genome of an extinct marsupial, the Tasmanian tiger (Thylacinus cynocephalus or thylacine, obtained from 100 year-old ethanol-fixed tissues from museum collections. We then examined the function of the enhancer in vivo. Using a transgenic approach, it was possible to resurrect DNA function in transgenic mice. The results demonstrate that the thylacine Col2A1 enhancer directed chondrocyte-specific expression in this extinct mammalian species in the same way as its orthologue does in mice. While other studies have examined extinct coding DNA function in vitro, this is the first example of the restoration of extinct non-coding DNA and examination of its function in vivo. Our method using transgenesis can be used to explore the function of regulatory and protein-coding sequences obtained from any extinct species in an in vivo model system, providing important insights into gene evolution and diversity.

  20. Fish extinctions alter nutrient recycling in tropical freshwaters.

    Science.gov (United States)

    McIntyre, Peter B; Jones, Laura E; Flecker, Alexander S; Vanni, Michael J

    2007-03-13

    There is increasing evidence that species extinctions jeopardize the functioning of ecosystems. Overfishing and other human influences are reducing the diversity and abundance of fish worldwide, but the ecosystem-level consequences of these changes have not been assessed quantitatively. Recycling of nutrients is one important ecosystem process that is directly influenced by fish. Fish species vary widely in the rates at which they excrete nitrogen and phosphorus; thus, altering fish communities could affect nutrient recycling. Here, we use extensive field data on nutrient recycling rates and population sizes of fish species in a Neotropical river and Lake Tanganyika, Africa, to evaluate the effects of simulated extinctions on nutrient recycling. In both of these species-rich ecosystems, recycling was dominated by relatively few species, but contributions of individual species differed between nitrogen and phosphorus. Alternative extinction scenarios produced widely divergent patterns. Loss of the species targeted by fishermen led to faster declines in nutrient recycling than extinctions in order of rarity, body size, or trophic position. However, when surviving species were allowed to increase after extinctions, these compensatory responses had strong moderating effects even after losing many species. Our results underscore the complexity of predicting the consequences of extinctions from species-rich animal communities. Nevertheless, the importance of exploited species in nutrient recycling suggests that overfishing could have particularly detrimental effects on ecosystem functioning.

  1. Linking indices for biodiversity monitoring to extinction risk theory.

    Science.gov (United States)

    McCarthy, Michael A; Moore, Alana L; Krauss, Jochen; Morgan, John W; Clements, Christopher F

    2014-12-01

    Biodiversity indices often combine data from different species when used in monitoring programs. Heuristic properties can suggest preferred indices, but we lack objective ways to discriminate between indices with similar heuristics. Biodiversity indices can be evaluated by determining how well they reflect management objectives that a monitoring program aims to support. For example, the Convention on Biological Diversity requires reporting about extinction rates, so simple indices that reflect extinction risk would be valuable. We developed 3 biodiversity indices that are based on simple models of population viability that relate extinction risk to abundance. We based the first index on the geometric mean abundance of species and the second on a more general power mean. In a third index, we integrated the geometric mean abundance and trend. These indices require the same data as previous indices, but they also relate directly to extinction risk. Field data for butterflies and woodland plants and experimental studies of protozoan communities show that the indices correlate with local extinction rates. Applying the index based on the geometric mean to global data on changes in avian abundance suggested that the average extinction probability of birds has increased approximately 1% from 1970 to 2009. © 2014 The Authors. Conservation Biology published by Wiley Periodicals, Inc., on behalf of the Society for Conservation Biology.

  2. IR emission and UV extinction in two open clusters

    International Nuclear Information System (INIS)

    Hackwell, J.A.; Hecht, J.H.

    1989-01-01

    Recent models of interstellar extinction have shown the importance of understanding both the UV and IR properties of interstellar dust grains. IRAS data have shown variations in 60 and 100 micron emissions presumably due to the presence of IR cirrus, while recent observations in the UV by Fitzpatrick and Massa have identified components in the UV extinction curve which vary in different star regions. A Draine and Anderson model connects these results by proposing that different size variations in interstellar grains would cause distinct changes in both the IR emission and the UV extinction. In order to test this model it is necessary to make observations in well defined locations away from peculiar extinction regions. In the infrared this means looking away from the galactic plane so as to limit non-local sources of IR radiation. Two open clusters that are out of the galactic plane and which contain a number of late B and early A stars suitable for UV extinction studies, and whose IRAS data show variations in the 60/100 micron ratio were studied. Based on the Drain and Anderson model, variations were expected in their UV extinction curves that correlate with the IR cirrus emission

  3. A brief exegesis of End Triassic Extinction issues

    Science.gov (United States)

    Whiteside, J. H.; Grice, K.; Fox, C.; Kent, D. V.; Olsen, P. E.; Irmis, R. B.

    2017-12-01

    Recent reports of environmental proxy records through the end-Triassic extinction (ETE), in some cases coupled with high-resolution geochronologic data, provide new insights into cause and effect. For example, the emplacement of vast volumes of basalt in the Central Atlantic Magmatic Province (CAMP) are temporally associated with carbon isotopic excursions (CIEs), indications of widespread oceanic euxinia, distinct regional and perhaps very abrupt global sea level change, massive changes in atmospheric CO2, and the proliferation of "disaster" species, both on land and ocean. In the least, these indicate major disruptions in how the Earth works. However some striking and critical issues remain unresolved at a very basic level. Most important are the uncertainties in the stratigraphic relationships of marine extinctions to the various environmental proxy sections, particularly the GSSP for the base Hettangian in Austria, and the UK sections (notably St. Audrie's Bay). Here, the sequence of sporomorph and marine "invertebrate" turnover occurs in different order relative to the proxy record and lithostratigraphy. Thus the sequence of environmental events are, at present, of uncertain relationship to the extinction. Second, it is unclear what processes the various CIEs reflect in different environments; the canonical initial isotopic excursion in the UK, demonstrably correlatable over a huge area, was recorded in a lake in a restricted basin, unlike the isotopic data from surrounding marine strata. Could some CIEs in non-marine basins be diagenetic in nature, caused by the contact effects of overlying basalts? Finally, how does the clear and dramatic tropical non-marine record of the ETE, precisely located relative to the CAMP, relate to the marine record of the ETE, particularly at higher latitudes, where continental biotic turnover is not nearly as dramatic? Do these records correlate in a sufficiently tight temporal interval such that causation can be inferred? These

  4. Phenomenon of primary and secondary extinction in textured material

    International Nuclear Information System (INIS)

    Kryshtab, T.G.; Palacios G, J.; Mazin, M.O.

    2002-01-01

    A new X-ray diffraction method is proposed for a more exact calculation of pole figures to determine the crystallite orientation distribution function (CODF) in textured materials, by the introduction of a correction of the integrated intensity of the diffracted beam due to the phenomenon of extinction. Besides, for the case of a symmetrical Bragg reflection from an ''infinitely thick'' flat parallel plate textured sample a simple solution is developed for the problem of separation and determination of primary and secondary extinction parameters, which can be present simultaneously. The determination of these parameters gives additional information about crystallite structure and allows us to evaluate the average subgrains size and their disorientation, respectively. In this work according to the dynamic diffraction theory, it is shown that the extinction length, which is directly connected with the phenomenon of primary extinction, in the Bragg geometry for σ polarization (perpendicular) is independent on the wavelength used for a given reflection. On the other hand, the additional contribution from secondary extinction depends on X-ray wavelength due to the change of effective absorption coefficient. Considering this fact, the calculations of pole density and the parameters of primary and secondary extinction are performed using the same strong reflection for two different wavelengths and, for one of these wavelengths, a second order of reflection. For confirmation of the proposed method a partially cold rolled aluminium sample and an aluminium powder standard sample were measured. The corrected pole densities, the values of primary and secondary extinction and the average sizes of perfect coherent areas and average angle of disorientation of subgrains in the selected directions were obtained. The obtained results show that the precise X-ray diffraction characterization of textured materials requires the consideration, in general, of primary as well as secondary

  5. Self-regulation of trilobite diversity in Murero (middle Cambrian, Spain) due to compensatory extinction

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Villalta, J.S.

    2016-07-01

    As species accumulate in a community, competition for available ecospace is expected to prevent the addition of new species and to facilitate species extinction, thus producing a dynamic equilibrium of diversity. This mechanism remains under debate since its empirical support comes mainly from indirect or partial evidence, with very few direct tests at the species level. Here a new method is described to detect the presence of selfregulation feedbacks between species richness and turnover rates. It consists of Monte Carlo simulations which randomize the distribution of species ranges among stratigraphic intervals, providing predictions which allow the detection of genuine self-regulation feedbacks in the real data. Since the simulations include any potential bias due to preservation, sampling, or change in depositional environment, and these biases would also affect the real dataset, they are thus ruled out as explanations for any difference found. This method is applied to one of the best known fossiliferous sequences worldwide, the Rambla de Valdemiedes in Murero (RV1 section, middle Cambrian, Spain), a classic locality that has been studied for more than 150 years and which stands out due to its excellent sampling density, continuous deposition, and homogeneous fossil preservation. The results show that trilobite species richness was self-regulated due to positive feedback with extinction rate, which implies that compensatory extinction regulated this fauna in spite of the on-going Cambrian radiation. The lack of evidence of any origination feedback suggests ecological opportunities were not limiting for new species to colonize this Cambrian community. (Author)

  6. Adapt or Become Extinct!

    DEFF Research Database (Denmark)

    Goumas, Georgios; McKee, Sally A.; Själander, Magnus

    2011-01-01

    boundaries (walls) for applications which limit software development (parallel programming wall), performance (memory wall, communication wall) and viability (power wall). The only way to survive in such a demanding environment is by adaptation. In this paper we discuss how dynamic information collected...

  7. Total Environment of Change: Impacts of Climate Change and Social Transitions on Subsistence Fisheries in Northwest Alaska

    Directory of Open Access Journals (Sweden)

    Katie J. Moerlein

    2012-03-01

    Full Text Available Arctic ecosystems are undergoing rapid changes as a result of global climate change, with significant implications for the livelihoods of Arctic peoples. In this paper, based on ethnographic research conducted with the Iñupiaq communities of Noatak and Selawik in northwestern Alaska, we detail prominent environmental changes observed over the past twenty to thirty years and their impacts on subsistence-based lifestyles. However, we suggest that it is ultimately insufficient to try to understand how Arctic communities are experiencing and responding to climate change in isolation from other stressors. During interviews and participant observation documenting local observations of climatic and related environmental shifts and impacts to subsistence fishing practices, we find the inseparability of environmental, social, economic, cultural, and political realms for community residents. Many of our informants, who live in a mixed economy based on various forms of income and widespread subsistence harvesting of fish and game, perceive and experience climate change as embedded among numerous other factors affecting subsistence patterns and practices. Changing lifestyles, decreasing interest by younger generations in pursuing subsistence livelihoods, and economic challenges are greatly affecting contemporary subsistence patterns and practices in rural Alaska. Observations of climate change are perceived, experienced, and articulated to researchers through a broader lens of these linked lifestyle and cultural shifts. Therefore, we argue that to properly assess and understand the impacts of climate change on the subsistence practices in Arctic communities, we must also consider the total environment of change that is dramatically shaping the relationship between people, communities, and their surrounding environments.

  8. The atmospheric extinction of light

    International Nuclear Information System (INIS)

    Hughes, Stephen W; Powell, Sean; Carroll, Joshua; Cowley, Michael

    2016-01-01

    An experiment is described that enables students to understand the properties of atmospheric extinction due to Rayleigh scattering. The experiment requires the use of red, green and blue lasers attached to a travelling microscope or similar device. The laser beams are passed through an artificial atmosphere, made from milky water, at varying depths, before impinging on either a light meter or a photodiode integral to a Picotech Dr. DAQ ADC. A plot of measured spectral intensity verses depth reveals the contribution Rayleigh scattering has to the extinction coefficient. For the experiment with the light meter, the extinction coefficients for red, green and blue light in the milky sample of water were 0.27, 0.36 and 0.47 cm −1 respectively and 0.032, 0.037 and 0.092 cm −1 for the Picotech Dr. DAQ ADC. (paper)

  9. Infectious Disease, Endangerment, and Extinction

    Science.gov (United States)

    MacPhee, Ross D. E.; Greenwood, Alex D.

    2013-01-01

    Infectious disease, especially virulent infectious disease, is commonly regarded as a cause of fluctuation or decline in biological populations. However, it is not generally considered as a primary factor in causing the actual endangerment or extinction of species. We review here the known historical examples in which disease has, or has been assumed to have had, a major deleterious impact on animal species, including extinction, and highlight some recent cases in which disease is the chief suspect in causing the outright endangerment of particular species. We conclude that the role of disease in historical extinctions at the population or species level may have been underestimated. Recent methodological breakthroughs may lead to a better understanding of the past and present roles of infectious disease in influencing population fitness and other parameters. PMID:23401844

  10. Altered primary production during mass-extinction events

    NARCIS (Netherlands)

    van de Schootbrugge, B.; Gollner, S.

    2013-01-01

    The Big Five mass-extinction events are characterized by dramatic changes in primary producers. Initial disturbance to primary producers is usually followed by a succession of pioneers that represent qualitative and quantitative changes in standing crops of land plants and/or phytoplankton. On land,

  11. The role of the dorsal striatum in extinction: A memory systems perspective.

    Science.gov (United States)

    Goodman, Jarid; Packard, Mark G

    2018-04-01

    The present review describes a role for the dorsal striatum in extinction. Evidence from brain lesion and pharmacological studies indicate that the dorsolateral region of the striatum (DLS) mediates extinction in various maze learning and instrumental learning tasks. Within the context of a multiple memory systems view, the role of the DLS in extinction appears to be selective. Specifically, the DLS mediates extinction of habit memory and is not required for extinction of cognitive memory. Thus, extinction mechanisms mediated by the DLS may involve response-produced inhibition (e.g. inhibition of existing stimulus-response associations or formation of new inhibitory stimulus-response associations), as opposed to cognitive mechanisms (e.g. changes in expectation). Evidence also suggests that NMDA-dependent forms of synaptic plasticity may be part of the mechanism through which the DLS mediates extinction of habit memory. In addition, in some learning situations, DLS inactivation enhances extinction, suggesting a competitive interaction between multiple memory systems during extinction training. Consistent with a multiple memory systems perspective, it is suggested that the DLS represents one of several distinct neural systems that specialize in extinction of different kinds of memory. The relevance of these findings to the development of behavioral and pharmacological therapies that target the maladaptive habit-like symptoms in human psychopathology is also briefly considered. Published by Elsevier Inc.

  12. Alterations in neuronal morphology in infralimbic cortex predict resistance to fear extinction following acute stress

    Directory of Open Access Journals (Sweden)

    Kelly M. Moench

    2016-06-01

    Full Text Available Dysfunction in corticolimbic circuits that mediate the extinction of learned fear responses is thought to underlie the perseveration of fear in stress-related psychopathologies, including post-traumatic stress disorder. Chronic stress produces dendritic hypertrophy in basolateral amygdala (BLA and dendritic hypotrophy in medial prefrontal cortex, whereas acute stress leads to hypotrophy in both BLA and prelimbic cortex. Additionally, both chronic and acute stress impair extinction retrieval. Here, we examined the effects of a single elevated platform stress on extinction learning and dendritic morphology in infralimbic cortex, a region considered to be critical for extinction. Acute stress produced resistance to extinction, as well as dendritic retraction in infralimbic cortex. Spine density on apical and basilar terminal branches was unaffected by stress. However, animals that underwent conditioning and extinction had decreased spine density on apical terminal branches. Thus, whereas dendritic morphology in infralimbic cortex appears to be particularly sensitive to stress, changes in spines may more sensitively reflect learning. Further, in stressed rats that underwent conditioning and extinction, the level of extinction learning was correlated with spine densities, in that rats with poorer extinction retrieval had more immature spines and fewer thin spines than rats with better extinction retrieval, suggesting that stress may have impaired learning-related spine plasticity. These results may have implications for understanding the role of medial prefrontal cortex in learning deficits associated with stress-related pathologies.

  13. Regulation of extinction-related plasticity by opioid receptors in the ventrolateral periaqueductal gray matter

    Directory of Open Access Journals (Sweden)

    Ryan Parsons

    2010-08-01

    Full Text Available Recent work has led to a better understanding of the neural mechanisms underlying the extinction of Pavlovian fear conditioning. Long-term synaptic changes in the medial prefrontal cortex (mPFC are critical for extinction learning, but very little is currently known about how the mPFC and other brain areas interact during extinction. The current study examined the effect of drugs that impair the extinction of fear conditioning on the activation of the extracellular-related kinase/mitogen-activated protein kinase (ERK/MAPK in brain regions that likely participate in the consolidation of extinction learning. Inhibitors of opioid and N-methyl-D-aspartic acid (NMDA receptors were applied to the ventrolateral periaqueductal gray matter (vlPAG and amygdala shortly before extinction training. Results from these experiments show that blocking opioid receptors in the vlPAG prevented the formation of extinction memory, whereas NMDA receptor blockade had no effect. Conversely, blocking NMDA receptors in the amygdala disrupted the formation of fear extinction memory, but opioid receptor blockade in the same brain area did not. Subsequent experiments tested the effect of these drug treatments on the activation of the ERK/MAPK signaling pathway in various brain regions following extinction training. Only opioid receptor blockade in the vlPAG disrupted ERK phosphorylation in the mPFC and amygdala. These data support the idea that opiodergic signaling derived from the vlPAG affects plasticity across the brain circuit responsible for the formation of extinction memory.

  14. Interactions of forests, climate, water resources, and humans in a changing environment: research needs

    Science.gov (United States)

    Ge Sun; Catalina Segura

    2013-01-01

    The aim of the special issue “Interactions of Forests, Climate, Water Resources, and Humans in a Changing Environment” is to present case studies on the influences of natural and human disturbances on forest water resources under a changing climate. Studies in this collection of six papers cover a wide range of geographic regions from Australia to Nigeria with spatial...

  15. RECOMMENDATIONS FOR THE DISTRIBUTION STRATEGY IN CHANGING MARKET ENVIRONMENT : Case: Belgian Brewery Van Honsebrouck in Russia

    OpenAIRE

    Louckx, Yulia

    2014-01-01

    The efficient distribution strategy formulation becomes vital to the success and survival of any organization, especially when it is involved in international trade. Today’s world is particularly challenging due to rapidly changing market conditions. Therefore, in order to able to compete, satisfy customers, and meet the needs of other stakeholders profitably, it is crucial for any company to make profound market environment analyses, react to changes in the market and adjust strategies accor...

  16. Changes in hospital nurse work environments and nurse job outcomes: an analysis of panel data.

    Science.gov (United States)

    Kutney-Lee, Ann; Wu, Evan S; Sloane, Douglas M; Aiken, Linda H

    2013-02-01

    One strategy proposed to alleviate nursing shortages is the promotion of organizational efforts that will improve nurse recruitment and retention. Cross-sectional studies have shown that the quality of the nurse work environment is associated with nurse outcomes related to retention, but there have been very few longitudinal studies undertaken to examine this relationship. To demonstrate how rates of burnout, intention to leave, and job dissatisfaction changed in a panel of hospitals over time, and to explore whether these outcomes were associated with changes in nurse work environments. A retrospective, two-stage panel design was chosen for this study. Survey data collected from large random samples of registered nurses employed in Pennsylvania hospitals in 1999 and 2006 were used to derive hospital-level rates of burnout, intention to leave current position, and job dissatisfaction, and to classify the quality of nurses' work environments at both points in time. A two-period difference model was used to estimate the dependence of changes in rates of nurse burnout, intention to leave, and job dissatisfaction on changes in nurse work environments between 1999 and 2006 in 137 hospitals, accounting for concurrent changes in nurse staffing levels. In general, nurse outcomes improved between 1999 and 2006, with fewer nurses reporting burnout, intention to leave, and job dissatisfaction in 2006 as compared to 1999. Our difference models showed that improvements in work environment had a strong negative association with changes in rates of burnout (β=-6.42%, pjob dissatisfaction (β=-8.00%, pburnout, intention to leave current position, and job dissatisfaction. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. The persistence of the attentional bias to regularities in a changing environment.

    Science.gov (United States)

    Yu, Ru Qi; Zhao, Jiaying

    2015-10-01

    The environment often is stable, but some aspects may change over time. The challenge for the visual system is to discover and flexibly adapt to the changes. We examined how attention is shifted in the presence of changes in the underlying structure of the environment. In six experiments, observers viewed four simultaneous streams of objects while performing a visual search task. In the first half of each experiment, the stream in the structured location contained regularities, the shapes in the random location were randomized, and gray squares appeared in two neutral locations. In the second half, the stream in the structured or the random location may change. In the first half of all experiments, visual search was facilitated in the structured location, suggesting that attention was consistently biased toward regularities. In the second half, this bias persisted in the structured location when no change occurred (Experiment 1), when the regularities were removed (Experiment 2), or when new regularities embedded in the original or novel stimuli emerged in the previously random location (Experiments 3 and 6). However, visual search was numerically but no longer reliably faster in the structured location when the initial regularities were removed and new regularities were introduced in the previously random location (Experiment 4), or when novel random stimuli appeared in the random location (Experiment 5). This suggests that the attentional bias was weakened. Overall, the results demonstrate that the attentional bias to regularities was persistent but also sensitive to changes in the environment.

  18. New type of Piezoresistive Pressure Sensors for Environments with Rapidly Changing Temperature

    Directory of Open Access Journals (Sweden)

    Tykhan Myroslav

    2017-03-01

    Full Text Available The theoretical aspects of a new type of piezo-resistive pressure sensors for environments with rapidly changing temperatures are presented. The idea is that the sensor has two identical diaphragms which have different coefficients of linear thermal expansion. Therefore, when measuring pressure in environments with variable temperature, the diaphragms will have different deflection. This difference can be used to make appropriate correction of the sensor output signal and, thus, to increase accuracy of measurement. Since physical principles of sensors operation enable fast correction of the output signal, the sensor can be used in environments with rapidly changing temperature, which is its essential advantage. The paper presents practical implementation of the proposed theoretical aspects and the results of testing the developed sensor.

  19. Generic framework for meso-scale assessment of climate change hazards in coastal environments

    DEFF Research Database (Denmark)

    Appelquist, Lars Rosendahl

    2013-01-01

    coastal environments worldwide through a specially designed coastal classification system containing 113 generic coastal types. The framework provides information on the degree to which key climate change hazards are inherent in a particular coastal environment, and covers the hazards of ecosystem......This paper presents a generic framework for assessing inherent climate change hazards in coastal environments through a combined coastal classification and hazard evaluation system. The framework is developed to be used at scales relevant for regional and national planning and aims to cover all...... and computing requirements, allowing for application in developing country settings. It is presented as a graphical tool—the Coastal Hazard Wheel—to ease its application for planning purposes....

  20. Climate Change Education: Quantitatively Assessing the Impact of a Botanical Garden as an Informal Learning Environment

    Science.gov (United States)

    Sellmann, Daniela; Bogner, Franz X.

    2013-01-01

    Although informal learning environments have been studied extensively, ours is one of the first studies to quantitatively assess the impact of learning in botanical gardens on students' cognitive achievement. We observed a group of 10th graders participating in a one-day educational intervention on climate change implemented in a botanical garden.…

  1. [Impact of new trend of ecological environment changes on growth, reproduction and diffusion of Oncomelania hupensis].

    Science.gov (United States)

    Juan, Xie; Li-Yong, Wen

    2016-03-07

    Oncomelania hupensis is the only intermediate host of Schistosoma japonicum , and the growth, reproduction and distribution of O.hupensis play an important role in schistosomiasis prevalence and transmission. This article reviews the influence of the new trend of ecological environment changes on the growth, reproduction and diffusion of the snails.

  2. Effects of Conceptual Change Text Based Instruction on Ecology, Attitudes toward Biology and Environment

    Science.gov (United States)

    Çetin, Gülcan; Ertepinar, Hamide; Geban, Ömer

    2015-01-01

    The purpose of this study is to investigate the effects of the conceptual change text based instruction on ninth grade students' understanding of ecological concepts, and attitudes toward biology and environment. Participants were 82 ninth grade students in a public high school in the Northwestern Turkey. A treatment was employed over a five-week…

  3. Measuring the mechanical behavior of paperboard in a changing humidity environment

    Science.gov (United States)

    Dennis E. Gunderson; John M. Considine

    1986-01-01

    “Both the strength and stability of compressively loaded paperboard are known to be adversely affected by cyclic changes in relative humidity. Current research at the Forest Products Laboratory (FPL) seeks to observe and explain this phenomenon and to develop a simple, practical test to determine allowable "working loads" in cyclicmoisture environments. A new...

  4. Nursing Workload and the Changing Health Care Environment: A Review of the Literature

    Science.gov (United States)

    Neill, Denise

    2011-01-01

    Changes in the health care environment have impacted nursing workload, quality of care, and patient safety. Traditional nursing workload measures do not guarantee efficiency, nor do they adequately capture the complexity of nursing workload. Review of the literature indicates nurses perceive the quality of their work has diminished. Research has…

  5. Teaching Music Online: Changing Pedagogical Approach When Moving to the Online Environment

    Science.gov (United States)

    Johnson, Carol

    2017-01-01

    The development of educational technology has provided platforms for undergraduate music courses to take place in an online environment. While technology is available, this does not mean that all teaching staff are ready for the pedagogical change required to implement teaching online. A transformation of pedagogical practice (that is, to online…

  6. Extinction and ecological retreat in a community of primates

    Energy Technology Data Exchange (ETDEWEB)

    Crowley, B. E.; Godfrey, L. R.; Guilderson, T. P.; Zermeno, P.; Koch, P. L.; Dominy, N. J.

    2012-05-23

    The lemurs of Madagascar represent a prodigious adaptive radiation. At least 17 species ranging from 11 to 160 kg have become extinct during the past 2000 years. The effect of this loss on contemporary lemurs is unknown. The concept of competitive release favours the expansion of living species into vacant niches. Alternatively, factors that triggered the extinction of some species could have also reduced community-wide niche breadth. Here, we use radiocarbon and stable isotope data to examine temporal shifts in the niches of extant lemur species following the extinction of eight large-bodied species. We focus on southwestern Madagascar and report profound isotopic shifts, both from the time when now-extinct lemurs abounded and from the time immediately following their decline to the present. Unexpectedly, the past environments exploited by lemurs were drier than the protected (albeit often degraded) riparian habitats assumed to be ideal for lemurs today. Neither competitive release nor niche contraction can explain these observed trends. We develop an alternative hypothesis: ecological retreat, which suggests that factors surrounding extinction may force surviving species into marginal or previously unfilled niches.

  7. Testing Models for the Contributions of Genes and Environment to Developmental Change in Adolescent Depression.

    Science.gov (United States)

    Gillespie, Nathan A; Eaves, Lindon J; Maes, Hermine; Silberg, Judy L

    2015-07-01

    We tested two models to identify the genetic and environmental processes underlying longitudinal changes in depression among adolescents. The first assumes that observed changes in covariance structure result from the unfolding of inherent, random individual differences in the overall levels and rates of change in depression over time (random growth curves). The second assumes that observed changes are due to time-specific random effects (innovations) accumulating over time (autoregressive effects). We found little evidence of age-specific genetic effects or persistent genetic innovations. Instead, genetic effects are consistent with a gradual unfolding in the liability to depression and rates of change with increasing age. Likewise, the environment also creates significant individual differences in overall levels of depression and rates of change. However, there are also time-specific environmental experiences that persist with fidelity. The implications of these differing genetic and environmental mechanisms in the etiology of depression are considered.

  8. Neutron time-of-flight techniques for investigation of the extinction effect

    International Nuclear Information System (INIS)

    Niimura, N.; Tomiyoshi, S.; Takahashi, J.; Harada, J.

    1975-01-01

    An application of the time-of-flight neutron diffraction technique to an investigation of the nature of the extinction effect in a single-crystal specimen is given. It is shown that the wavelength dependence of the extinction can be easily obtained by changing the scattering angle. An estimation of the extinction factor for a CuCl single crystal is given as an example and a comparison of the results with recent extinction theory [Becker and Coppens. Acta Cryst.(1974). A30, 129-147; 148-153] is made. (Auth.)

  9. Carbon cycling and mass extinctions: the Permo-Triassic of the Arabian Margin.

    OpenAIRE

    Clarkson, Matthew Oliver

    2014-01-01

    The end-Permian extinction at 252 Ma is widely regarded as the most severe of the Phanerozoic mass-extinctions and enabled the evolution of the modern carbon cycle and ecosystem structure. The cause of the extinction is still debated but the synergistic pressures of global climate change, such as anoxia and ocean acidification, were clearly important. The extinction occurred in two phases and is marked by a uniquely protracted recovery period of ~ 5 Myrs where diversity fails to reach pre-ext...

  10. Tracking a changing environment: optimal sampling, adaptive memory and overnight effects.

    Science.gov (United States)

    Dunlap, Aimee S; Stephens, David W

    2012-02-01

    Foraging in a variable environment presents a classic problem of decision making with incomplete information. Animals must track the changing environment, remember the best options and make choices accordingly. While several experimental studies have explored the idea that sampling behavior reflects the amount of environmental change, we take the next logical step in asking how change influences memory. We explore the hypothesis that memory length should be tied to the ecological relevance and the value of the information learned, and that environmental change is a key determinant of the value of memory. We use a dynamic programming model to confirm our predictions and then test memory length in a factorial experiment. In our experimental situation we manipulate rates of change in a simple foraging task for blue jays over a 36 h period. After jays experienced an experimentally determined change regime, we tested them at a range of retention intervals, from 1 to 72 h. Manipulated rates of change influenced learning and sampling rates: subjects sampled more and learned more quickly in the high change condition. Tests of retention revealed significant interactions between retention interval and the experienced rate of change. We observed a striking and surprising difference between the high and low change treatments at the 24h retention interval. In agreement with earlier work we find that a circadian retention interval is special, but we find that the extent of this 'specialness' depends on the subject's prior experience of environmental change. Specifically, experienced rates of change seem to influence how subjects balance recent information against past experience in a way that interacts with the passage of time. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Global warming and extinctions of endemic species from biodiversity hotspots.

    Science.gov (United States)

    Malcolm, Jay R; Liu, Canran; Neilson, Ronald P; Hansen, Lara; Hannah, Lee

    2006-04-01

    Global warming is a key threat to biodiversity, but few researchers have assessed the magnitude of this threat at the global scale. We used major vegetation types (biomes) as proxies for natural habitats and, based on projected future biome distributions under doubled-CO2 climates, calculated changes in habitat areas and associated extinctions of endemic plant and vertebrate species in biodiversity hotspots. Because of numerous uncertainties in this approach, we undertook a sensitivity analysis of multiple factors that included (1) two global vegetation models, (2) different numbers of biome classes in our biome classification schemes, (3) different assumptions about whether species distributions were biome specific or not, and (4) different migration capabilities. Extinctions were calculated using both species-area and endemic-area relationships. In addition, average required migration rates were calculated for each hotspot assuming a doubled-CO2 climate in 100 years. Projected percent extinctions ranged from hotspots were the Cape Floristic Region, Caribbean, Indo-Burma, Mediterranean Basin, Southwest Australia, and Tropical Andes, where plant extinctions per hotspot sometimes exceeded 2000 species. Under the assumption that projected habitat changes were attained in 100 years, estimated global-warming-induced rates of species extinctions in tropical hotspots in some cases exceeded those due to deforestation, supporting suggestions that global warming is one of the most serious threats to the planet's biodiversity.

  12. Changes in school environments with implementation of Arkansas Act 1220 of 2003.

    Science.gov (United States)

    Phillips, Martha M; Raczynski, James M; West, Delia S; Pulley, LeaVonne; Bursac, Zoran; Gauss, C Heath; Walker, Jada F

    2010-02-01

    Changes in school nutrition and physical activity policies and environments are important to combat childhood obesity. Arkansas Act 1220 of 2003 was among the first and most comprehensive statewide legislative initiatives to combat childhood obesity through school-based change. Annual surveys of principals and superintendents have been analyzed to document substantial and important changes in school environments, policies, and practices. For example, results indicate that schools are more likely to require that healthy options be provided for student parties (4.5% in 2004, 36.9% in 2008; P ban commercial advertising by food or beverage companies (31.7% in 2005, 42.6% in 2008; P vending machines available during the lunch period (72.3% in 2004, 37.2% in 2008; P vending machines (83.8% in 2004, 73.5% in 2008; P changes were noted in foods and beverages offered in the cafeteria, in classrooms, and at school events, as well as in fund-raising and physical activity practices. A significant number of school districts have modified physical education requirements for elementary schools and developed policies prohibiting the use of physical activity as a punishment. We conclude that Arkansas Act 1220 of 2003 is associated with a number of changes in school environments and policies, resulting from both statewide and local initiatives spawned by the Act.

  13. Mass Extinctions and Supernova Explosions

    Science.gov (United States)

    Korschinek, Gunther

    A nearby supernova (SN) explosion could have negatively influenced life on Earth, maybe even been responsible for mass extinctions. Mass extinction poses a significant extinction of numerous species on Earth, as recorded in the paleontologic, paleoclimatic, and geological record of our planet. Depending on the distance between the Sun and the SN, different types of threats have to be considered, such as ozone depletion on Earth, causing increased exposure to the Sun's ultraviolet radiation or the direct exposure of lethal X-rays. Another indirect effect is cloud formation, induced by cosmic rays in the atmosphere which result in a drop in the Earth's temperature, causing major glaciations of the Earth. The discovery of highly intensive gamma-ray bursts (GRBs), which could be connected to SNe, initiated further discussions on possible life-threatening events in the Earth's history. The probability that GRBs hit the Earth is very low. Nevertheless, a past interaction of Earth with GRBs and/or SNe cannot be excluded and might even have been responsible for past extinction events.

  14. Modeling Population Growth and Extinction

    Science.gov (United States)

    Gordon, Sheldon P.

    2009-01-01

    The exponential growth model and the logistic model typically introduced in the mathematics curriculum presume that a population grows exclusively. In reality, species can also die out and more sophisticated models that take the possibility of extinction into account are needed. In this article, two extensions of the logistic model are considered,…

  15. New theories about ancient extinctions

    Science.gov (United States)

    Spall, H.

    1986-01-01

    The abrupt disappearance of all the dinosaurs about 65 million years ago, along with perhaps half the plant species and other animals, has been one of the great geological mysteries. Clues to the cause of these extinctions have been scarce and open to many interpretations.

  16. Extinction debt on oceanic islands

    DEFF Research Database (Denmark)

    Triantis, Kostas A.; Borges, Paulo A. V.; Ladle, Richard J.

    2010-01-01

    the magnitude of such future extinction events has been hampered by potentially inaccurate assumptions about the slope of species-area relationships, which are habitat- and taxon-specific. We overcome this challenge by applying a method that uses the historical sequence of deforestation in the Azorean Islands...

  17. The currency and tempo of extinction.

    Science.gov (United States)

    Regan, H M; Lupia, R; Drinnan, A N; Burgman, M A

    2001-01-01

    This study examines estimates of extinction rates for the current purported biotic crisis and from the fossil record. Studies that compare current and geological extinctions sometimes use metrics that confound different sources of error and reflect different features of extinction processes. The per taxon extinction rate is a standard measure in paleontology that avoids some of the pitfalls of alternative approaches. Extinction rates reported in the conservation literature are rarely accompanied by measures of uncertainty, despite many elements of the calculations being subject to considerable error. We quantify some of the most important sources of uncertainty and carry them through the arithmetic of extinction rate calculations using fuzzy numbers. The results emphasize that estimates of current and future rates rely heavily on assumptions about the tempo of extinction and on extrapolations among taxa. Available data are unlikely to be useful in measuring magnitudes or trends in current extinction rates.

  18. 11th National Conference on Science, Policy, and the Environment: Our Changing Oceans

    Energy Technology Data Exchange (ETDEWEB)

    Peter Saundry

    2012-04-17

    On January 19-21, 2011, The National Council for Science and the Environment (NCSE) successfully convened its 11th National Conference on Science, Policy and the Environment: Our Changing Oceans in Washington, DC at the Ronald Reagan Building and International Trade Center. Over 1,247 participants attended the conference, representing federal, state and local governments, university and colleges across the US, civil society organizations, the business community, and international entities. In addition, the conference was webcast to an audience across several states. The conference provided a forum to examine the profound changes our ocean will undergo over the next 25-50 years and share various perspectives on the new research, tools, and policy initiatives to protect and sustain our ocean. Conference highlights and recommendations are available to the public on NCSE's conference website, www.OurChangingOceans.org.

  19. Review of the Korean SSAC According to Changes in the Nuclear Environment

    International Nuclear Information System (INIS)

    Kim, Min Su; Yoon, Wan Ki; Choe, Kwan Kyoo; Jo, Seong Youn; Park, Jae Bum

    2005-01-01

    Korea has been maintaining efficient and systematic State System for Accounting and Control of nuclear materials (SSAC) for elevation of our nuclear transparency and reliability to international society. So far, Korean SSAC had been considered as a good example of SSAC together with Euratom, Japan, ABACC. But, owing to changing environment such as a series trial due to the KAERI's past nuclear material experiments, strengthened international nonproliferation scheme, advent of integrated safeguards and technology development in nuclear fields, voices of demand for changes in Korean SSAC are being brought up. Therefore, this study grasped and analyzed international nuclear environment and direction of changes in nuclear control regime, besides re-examine the roles of Korean SSAC and proposed the direction where Korean SSAC should be shifted

  20. Mapping of Danish Law Related to Companies' Impact on Environment and Climate Change

    DEFF Research Database (Denmark)

    Buhmann, Karin; Østergaard, Kim; Feldthusen, Rasmus Kristian

    for Danish law related to environment and climate change and CSR in a general sense, sources of law and jurisdiction specific issues, types of companies, shareholding structure etc. (section 1); the purpose of the company, duties and competence of the company organs, and corporate governance issues (section......This overview of Danish law related to companies’ conduct and impact on environment and climate change has been undertaken under the ‘Sustainable Companies’ project hosted at the Department of Private Law at the University of Oslo. The ‘mapping’ of national law – including in particular company law....... Environmental law has been seen under the project as essentially related to climate change. Some other issues related to sustainable development and company conduct have been addressed as well, in particular in relation to Corporate Social Responsibility (CSR). In the current paper, this particularly applies...

  1. Direct numerical simulations of non-premixed ethylene-air flames: Local flame extinction criterion

    KAUST Repository

    Lecoustre, Vivien R.

    2014-11-01

    Direct Numerical Simulations (DNS) of ethylene/air diffusion flame extinctions in decaying two-dimensional turbulence were performed. A Damköhler-number-based flame extinction criterion as provided by classical large activation energy asymptotic (AEA) theory is assessed for its validity in predicting flame extinction and compared to one based on Chemical Explosive Mode Analysis (CEMA) of the detailed chemistry. The DNS code solves compressible flow conservation equations using high order finite difference and explicit time integration schemes. The ethylene/air chemistry is simulated with a reduced mechanism that is generated based on the directed relation graph (DRG) based methods along with stiffness removal. The numerical configuration is an ethylene fuel strip embedded in ambient air and exposed to a prescribed decaying turbulent flow field. The emphasis of this study is on the several flame extinction events observed in contrived parametric simulations. A modified viscosity and changing pressure (MVCP) scheme was adopted in order to artificially manipulate the probability of flame extinction. Using MVCP, pressure was changed from the baseline case of 1 atm to 0.1 and 10 atm. In the high pressure MVCP case, the simulated flame is extinction-free, whereas in the low pressure MVCP case, the simulated flame features frequent extinction events and is close to global extinction. Results show that, despite its relative simplicity and provided that the global flame activation temperature is correctly calibrated, the AEA-based flame extinction criterion can accurately predict the simulated flame extinction events. It is also found that the AEA-based criterion provides predictions of flame extinction that are consistent with those provided by a CEMA-based criterion. This study supports the validity of a simple Damköhler-number-based criterion to predict flame extinction in engineering-level CFD models. © 2014 The Combustion Institute.

  2. Improving the adaptability of simulated evolutionary swarm robots in dynamically changing environments.

    Directory of Open Access Journals (Sweden)

    Yao Yao

    Full Text Available One of the important challenges in the field of evolutionary robotics is the development of systems that can adapt to a changing environment. However, the ability to adapt to unknown and fluctuating environments is not straightforward. Here, we explore the adaptive potential of simulated swarm robots that contain a genomic encoding of a bio-inspired gene regulatory network (GRN. An artificial genome is combined with a flexible agent-based system, representing the activated part of the regulatory network that transduces environmental cues into phenotypic behaviour. Using an artificial life simulation framework that mimics a dynamically changing environment, we show that separating the static from the conditionally active part of the network contributes to a better adaptive behaviour. Furthermore, in contrast with most hitherto developed ANN-based systems that need to re-optimize their complete controller network from scratch each time they are subjected to novel conditions, our system uses its genome to store GRNs whose performance was optimized under a particular environmental condition for a sufficiently long time. When subjected to a new environment, the previous condition-specific GRN might become inactivated, but remains present. This ability to store 'good behaviour' and to disconnect it from the novel rewiring that is essential under a new condition allows faster re-adaptation if any of the previously observed environmental conditions is reencountered. As we show here, applying these evolutionary-based principles leads to accelerated and improved adaptive evolution in a non-stable environment.

  3. Improving the Adaptability of Simulated Evolutionary Swarm Robots in Dynamically Changing Environments

    Science.gov (United States)

    Yao, Yao; Marchal, Kathleen; Van de Peer, Yves

    2014-01-01

    One of the important challenges in the field of evolutionary robotics is the development of systems that can adapt to a changing environment. However, the ability to adapt to unknown and fluctuating environments is not straightforward. Here, we explore the adaptive potential of simulated swarm robots that contain a genomic encoding of a bio-inspired gene regulatory network (GRN). An artificial genome is combined with a flexible agent-based system, representing the activated part of the regulatory network that transduces environmental cues into phenotypic behaviour. Using an artificial life simulation framework that mimics a dynamically changing environment, we show that separating the static from the conditionally active part of the network contributes to a better adaptive behaviour. Furthermore, in contrast with most hitherto developed ANN-based systems that need to re-optimize their complete controller network from scratch each time they are subjected to novel conditions, our system uses its genome to store GRNs whose performance was optimized under a particular environmental condition for a sufficiently long time. When subjected to a new environment, the previous condition-specific GRN might become inactivated, but remains present. This ability to store ‘good behaviour’ and to disconnect it from the novel rewiring that is essential under a new condition allows faster re-adaptation if any of the previously observed environmental conditions is reencountered. As we show here, applying these evolutionary-based principles leads to accelerated and improved adaptive evolution in a non-stable environment. PMID:24599485

  4. Transpiration of shrub species, Alnus firma under changing atmospheric environments in montane area, Japan

    Science.gov (United States)

    Miyazawa, Y.; Maruyama, A.; Inoue, A.

    2014-12-01

    In the large caldera of Mt. Aso in Japan, grasslands have been traditionally managed by the farmers. Due to changes in the social structure of the region, a large area of the grassland has been abandoned and was invaded by the shrubs with different hydrological and ecophysiological traits. Ecophysiological traits and their responses to seasonally changing environments are fundamental to project the transpiration rates under changing air and soil water environments, but less is understood. We measured the tree- and leaf-level ecophysiological traits of a shrub, Alnus firma in montane region where both rainfall and soil water content drastically changes seasonally. Sap flux reached the annual peak in evaporative summer (July-August) both in 2013 and 2014, although the duration was limited within a short period due to the prolonged rainy season before summer (2014) and rapid decrease in the air vapor pressure deficit (D) in late summer. Leaf ecophysiological traits in close relationship with gas exchange showed modest seasonal changes and the values were kept at relatively high levels typical in plants with nitrogen fixation under nutrient-poor environments. Stomatal conductance, which was measured at leaf-level measurements and sap flux measurements, showed responses to D, which coincided with the theoretical response for isohydric leaves. A multilayer model, which estimates stand-level transpiration by scaling up the leaf-level data, successfully captured the temporal trends in sap flux, suggesting that major processes were incorporated. Thus, ecophysiological traits of A. firma were characterized by the absence of responses to seasonally changing environments and the transpiration rate was the function of the interannually variable environmental conditions.

  5. A Data Stream Model For Runoff Simulation In A Changing Environment

    Science.gov (United States)

    Yang, Q.; Shao, J.; Zhang, H.; Wang, G.

    2017-12-01

    Runoff simulation is of great significance for water engineering design, water disaster control, water resources planning and management in a catchment or region. A large number of methods including concept-based process-driven models and statistic-based data-driven models, have been proposed and widely used in worldwide during past decades. Most existing models assume that the relationship among runoff and its impacting factors is stationary. However, in the changing environment (e.g., climate change, human disturbance), their relationship usually evolves over time. In this study, we propose a data stream model for runoff simulation in a changing environment. Specifically, the proposed model works in three steps: learning a rule set, expansion of a rule, and simulation. The first step is to initialize a rule set. When a new observation arrives, the model will check which rule covers it and then use the rule for simulation. Meanwhile, Page-Hinckley (PH) change detection test is used to monitor the online simulation error of each rule. If a change is detected, the corresponding rule is removed from the rule set. In the second step, for each rule, if it covers more than a given number of instance, the rule is expected to expand. In the third step, a simulation model of each leaf node is learnt with a perceptron without activation function, and is updated with adding a newly incoming observation. Taking Fuxi River catchment as a case study, we applied the model to simulate the monthly runoff in the catchment. Results show that abrupt change is detected in the year of 1997 by using the Page-Hinckley change detection test method, which is consistent with the historic record of flooding. In addition, the model achieves good simulation results with the RMSE of 13.326, and outperforms many established methods. The findings demonstrated that the proposed data stream model provides a promising way to simulate runoff in a changing environment.

  6. Extinction of the weakest

    International Nuclear Information System (INIS)

    Denham, James W.; Kron, Tomas

    2001-01-01

    Purpose: To examine whether changes in the effective doubling time of tumor cells during irradiation of head-and-neck cancer are linked to accumulating dose. Methods and Materials: Optimal fitting of the results of four apparently iso-effective regimens in three recently reported randomized controlled trials (continuous hyperfractionated accelerated radiation therapy [CHART], Radiation Therapy Oncology Group [RTOG] 90-03, and Trans-Tasman Radiation Oncology Group [TROG] 91.01) was attempted using two different types of model of the change in effective doubling time that may occur during treatment. The first involved the traditional approach where doubling time changes at specific times after the start of treatment regardless of fractionation used ('fixed response time' models). The second is where changes in doubling time are linked to accumulating biologic dose ('cellular depletion' models). Results: Changes in effective doubling time occur during radiotherapy for head-and-neck cancer. Data from the three trials can be fitted successfully by functions that imply a continuous reduction in effective doubling time. Models linking the reductions in effective doubling time to the cellular depletion that occurs in the tumor during radiotherapy fit the data satisfactorily. Effective doubling time ultimately reduces to 2 days, or slightly less, during high-dose radiotherapy regimens designed to cure squamous head-and-neck cancer. Conclusions: If the assumption of iso-effectivity is justified then this study indicates that the 'repopulation phenomenon' may be best described by a function that depicts a reduction in effective tumor cell doubling time that decreases continuously during treatment down to a certain minimum value. Furthermore, this reduction may be linked to cellular depletion

  7. EARTH SCIENCE: Did Volcanoes Drive Ancient Extinctions?

    Science.gov (United States)

    Kerr, R A

    2000-08-18

    With the publication in recent weeks of two papers on a mass extinction 183 million years ago, researchers can add five suggestive cases to the list of extinctions with known causes. These extinctions coincide with massive outpourings of lava, accompanied by signs that global warming threw the ocean-atmosphere system out of whack. Although no one can yet pin any of these mass extinctions with certainty on the volcanic eruptions, scientists say it's unlikely that they're all coincidences.

  8. An investigation of the interstellar extinction

    International Nuclear Information System (INIS)

    Roche, P.F.; Aitken, D.K.; Melbourne Univ., Point Cook

    1984-01-01

    The 10 μm extinction towards six WC8 or WC9 Wolf-Rayet stars is investigated. All objects show smooth dust emission suffering silicate absorption with depths well correlated with the extinction in the visible. The de-reddened spectra are well represented by emission from featureless grain components, possibly from iron or carbon grains. The extinction to the stars is found to be dominantly interstellar in origin with little extinction from the circumstellar shell. (author)

  9. Autonomous Collision-Free Navigation of Microvehicles in Complex and Dynamically Changing Environments.

    Science.gov (United States)

    Li, Tianlong; Chang, Xiaocong; Wu, Zhiguang; Li, Jinxing; Shao, Guangbin; Deng, Xinghong; Qiu, Jianbin; Guo, Bin; Zhang, Guangyu; He, Qiang; Li, Longqiu; Wang, Joseph

    2017-09-26

    Self-propelled micro- and nanoscale robots represent a rapidly emerging and fascinating robotics research area. However, designing autonomous and adaptive control systems for operating micro/nanorobotics in complex and dynamically changing environments, which is a highly demanding feature, is still an unmet challenge. Here we describe a smart microvehicle for precise autonomous navigation in complicated environments and traffic scenarios. The fully autonomous navigation system of the smart microvehicle is composed of a microscope-coupled CCD camera, an artificial intelligence planner, and a magnetic field generator. The microscope-coupled CCD camera provides real-time localization of the chemically powered Janus microsphere vehicle and environmental detection for path planning to generate optimal collision-free routes, while the moving direction of the microrobot toward a reference position is determined by the external electromagnetic torque. Real-time object detection offers adaptive path planning in response to dynamically changing environments. We demonstrate that the autonomous navigation system can guide the vehicle movement in complex patterns, in the presence of dynamically changing obstacles, and in complex biological environments. Such a navigation system for micro/nanoscale vehicles, relying on vision-based close-loop control and path planning, is highly promising for their autonomous operation in complex dynamic settings and unpredictable scenarios expected in a variety of realistic nanoscale scenarios.

  10. Climate Change Potential Impacts on the Built Environment and Possible Adaptation Strategies

    Science.gov (United States)

    Quattrochi, Dale A.

    2014-01-01

    The built environment consists of components that exist at a range of scales from small (e.g., houses, shopping malls) to large (e.g., transportation networks) to highly modified landscapes such as cities. Thus, the impacts of climate change on the built environment may have a multitude of effects on humans and the land. The impact of climate change may be exacerbated by the interaction of different events that singly may be minor, but together may have a synergistic set of impacts that are significant. Also, mechanisms may exist wherein the built environment, particularly in the form of cities, may affect weather and the climate on local and regional scales. Hence, a city may be able to cope with prolonged heat waves, but if this is combined with severe drought, the overall result could be significant or even catastrophic, as accelerating demand for energy to cooling taxes water supplies needed both for energy supply and municipal water needs. This presentation surveys potential climate change impacts on the built environment from the perspective of the National Climate Assessment, and explores adaptation measures that can be employed to mitigate these impacts.

  11. Food Environment and Weight Change: Does Residential Mobility Matter?: The Diabetes Study of Northern California (DISTANCE).

    Science.gov (United States)

    Laraia, Barbara A; Downing, Janelle M; Zhang, Y Tara; Dow, William H; Kelly, Maggi; Blanchard, Samuel D; Adler, Nancy; Schillinger, Dean; Moffet, Howard; Warton, E Margaret; Karter, Andrew J

    2017-05-01

    Associations between neighborhood food environment and adult body mass index (BMI; weight (kg)/height (m)2) derived using cross-sectional or longitudinal random-effects models may be biased due to unmeasured confounding and measurement and methodological limitations. In this study, we assessed the within-individual association between change in food environment from 2006 to 2011 and change in BMI among adults with type 2 diabetes using clinical data from the Kaiser Permanente Diabetes Registry collected from 2007 to 2011. Healthy food environment was measured using the kernel density of healthful food venues. Fixed-effects models with a 1-year-lagged BMI were estimated. Separate models were fitted for persons who moved and those who did not. Sensitivity analysis using different lag times and kernel density bandwidths were tested to establish the consistency of findings. On average, patients lost 1 pound (0.45 kg) for each standard-deviation improvement in their food environment. This relationship held for persons who remained in the same location throughout the 5-year study period but not among persons who moved. Proximity to food venues that promote nutritious foods alone may not translate into clinically meaningful diet-related health changes. Community-level policies for improving the food environment need multifaceted strategies to invoke clinically meaningful change in BMI among adult patients with diabetes. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Climate Change and Regulation in International and Regional Level, Especially the Built Environment

    Directory of Open Access Journals (Sweden)

    Putnoki Zsuzsanna

    2015-12-01

    Full Text Available The article starts with a brief insight into the history of climate change, with a scope on the international and legal aspects of ever-changing regulations. The regional level is in the article is The European Union, as the only regional economic integration organization under the Kyoto Protocol. It deals with the United Nation’s international agreements like UNFCCC its Kyoto’s Protocol and the Post-Kyoto era. It also analyses the EU’s system in the climate change law with correspondence the international rules. Comparison between international and regional legislation in the climate change is used as a tool of analysis. Finally an insight is given into a special field in the climate change, the build environment, reflecting on the related United Nation’s recommendation and the EU’s regulation.

  13. Further Evidence of Auditory Extinction in Aphasia

    Science.gov (United States)

    Marshall, Rebecca Shisler; Basilakos, Alexandra; Love-Myers, Kim

    2013-01-01

    Purpose: Preliminary research ( Shisler, 2005) suggests that auditory extinction in individuals with aphasia (IWA) may be connected to binding and attention. In this study, the authors expanded on previous findings on auditory extinction to determine the source of extinction deficits in IWA. Method: Seventeen IWA (M[subscript age] = 53.19 years)…

  14. Emotional Perseveration: An Update on Prefrontal-Amygdala Interactions in Fear Extinction

    Science.gov (United States)

    Sotres-Bayon, Francisco; Bush, David E. A.; LeDoux, Joseph E.

    2004-01-01

    Fear extinction refers to the ability to adapt as situations change by learning to suppress a previously learned fear. This process involves a gradual reduction in the capacity of a fear-conditioned stimulus to elicit fear by presenting the conditioned stimulus repeatedly on its own. Fear extinction is context-dependent and is generally considered…

  15. The butterflies of Barro Colorado Island: Local extinction rates since the 1930's

    Science.gov (United States)

    Few data are available about the regional or local extinction of tropical butterfly species. When confirmed, local extinction was often due to the loss of host-plant species. We used published lists and recent monitoring programs to evaluate changes in butterfly composition on Barro Colorado Island ...

  16. Feature Optimization for Long-Range Visual Homing in Changing Environments

    Directory of Open Access Journals (Sweden)

    Qidan Zhu

    2014-02-01

    Full Text Available This paper introduces a feature optimization method for robot long-range feature-based visual homing in changing environments. To cope with the changing environmental appearance, the optimization procedure is introduced to distinguish the most relevant features for feature-based visual homing, including the spatial distribution, selection and updating. In the previous research on feature-based visual homing, less effort has been spent on the way to improve the feature distribution to get uniformly distributed features, which are closely related to homing performance. This paper presents a modified feature extraction algorithm to decrease the influence of anisotropic feature distribution. In addition, the feature selection and updating mechanisms, which have hardly drawn any attention in the domain of feature-based visual homing, are crucial in improving homing accuracy and in maintaining the representation of changing environments. To verify the feasibility of the proposal, several comprehensive evaluations are conducted. The results indicate that the feature optimization method can find optimal feature sets for feature-based visual homing, and adapt the appearance representation to the changing environments as well.

  17. The influence of recent climate change on tree height growth differs with species and spatial environment.

    Science.gov (United States)

    Messaoud, Yassine; Chen, Han Y H

    2011-02-16

    Tree growth has been reported to increase in response to recent global climate change in controlled and semi-controlled experiments, but few studies have reported response of tree growth to increased temperature and atmospheric carbon dioxide (CO₂) concentration in natural environments. This study addresses how recent global climate change has affected height growth of trembling aspen (Populus tremuloides Michx) and black spruce (Picea mariana Mill B.S.) in their natural environments. We sampled 145 stands dominated by aspen and 82 dominated by spruce over the entire range of their distributions in British Columbia, Canada. These stands were established naturally after fire between the 19th and 20th centuries. Height growth was quantified as total heights of sampled dominant and co-dominant trees at breast-height age of 50 years. We assessed the relationships between 50-year height growth and environmental factors at both spatial and temporal scales. We also tested whether the tree growth associated with global climate change differed with spatial environment (latitude, longitude and elevation). As expected, height growth of both species was positively related to temperature variables at the regional scale and with soil moisture and nutrient availability at the local scale. While height growth of trembling aspen was not significantly related to any of the temporal variables we examined, that of black spruce increased significantly with stand establishment date, the anomaly of the average maximum summer temperature between May-August, and atmospheric CO₂ concentration, but not with the Palmer Drought Severity Index. Furthermore, the increase of spruce height growth associated with recent climate change was higher in the western than in eastern part of British Columbia. This study demonstrates that the response of height growth to recent climate change, i.e., increasing temperature and atmospheric CO₂ concentration, did not only differ with tree species, but

  18. Changes to the school food and physical activity environment after guideline implementation in British Columbia, Canada

    Science.gov (United States)

    2014-01-01

    Background High rates of childhood obesity have generated interest among policy makers to improve the school food environment and increase students’ levels of physical activity. The purpose of this study was to examine school-level changes associated with implementation of the Food and Beverage Sales in Schools (FBSS) and Daily Physical Activity (DPA) guidelines in British Columbia, Canada. Methods Elementary and middle/high school principals completed a survey on the school food and physical activity environment in 2007–08 (N = 513) and 2011–12 (N = 490). Hierarchical mixed effects regression was used to examine changes in: 1) availability of food and beverages; 2) minutes per day of Physical Education (PE); 3) delivery method of PE; and 4) school community support. Models controlled for school enrollment and community type, education and income. Results After policy implementation was expected, more elementary schools provided access to fruits and vegetables and less to 100% fruit juice. Fewer middle/high schools provided access to sugar-sweetened beverages, French fries, baked goods, salty snacks and chocolate/candy. Schools were more likely to meet 150 min/week of PE for grade 6 students, and offer more minutes of PE per week for grade 8 and 10 students including changes to PE delivery method. School community support for nutrition and physical activity policies increased over time. Conclusion Positive changes to the school food environment occurred after schools were expected to implement the FBSS and DPA guidelines. Reported changes to the school environment are encouraging and provide support for guidelines and policies that focus on increasing healthy eating and physical activity in schools. PMID:24731514

  19. Strategic Environmental Assessment Framework for Landscape-Based, Temporal Analysis of Wetland Change in Urban Environments.

    Science.gov (United States)

    Sizo, Anton; Noble, Bram F; Bell, Scott

    2016-03-01

    This paper presents and demonstrates a spatial framework for the application of strategic environmental assessment (SEA) in the context of change analysis for urban wetland environments. The proposed framework is focused on two key stages of the SEA process: scoping and environmental baseline assessment. These stages are arguably the most information-intense phases of SEA and have a significant effect on the quality of the SEA results. The study aims to meet the needs for proactive frameworks to assess and protect wetland habitat and services more efficiently, toward the goal of advancing more intelligent urban planning and development design. The proposed framework, adopting geographic information system and remote sensing tools and applications, supports the temporal evaluation of wetland change and sustainability assessment based on landscape indicator analysis. The framework was applied to a rapidly developing urban environment in the City of Saskatoon, Saskatchewan, Canada, analyzing wetland change and land-use pressures from 1985 to 2011. The SEA spatial scale was rescaled from administrative urban planning units to an ecologically meaningful area. Landscape change assessed was based on a suite of indicators that were subsequently rolled up into a single, multi-dimensional, and easy to understand and communicate index to examine the implications of land-use change for wetland sustainability. The results show that despite the recent extremely wet period in the Canadian prairie region, land-use change contributed to increasing threats to wetland sustainability.

  20. Get Active Orlando: changing the built environment to increase physical activity.

    Science.gov (United States)

    McCreedy, Malisa; Leslie, Jill G

    2009-12-01

    Active Living by Design's Get Active Orlando partnership (GAO) focused on downtown Orlando's Community Redevelopment Area, including the Parramore Heritage District, home to many low-income and ethnically diverse residents, including many seniors. The area had undergone substantial development, and GAO aimed to incorporate active living considerations into the city's changing landscape. Get Active Orlando conducted a baseline survey of all streets, sidewalks, and bicycle lanes in the project area and identified a sequence of plans and policies in which to incorporate changes identified in the assessment. To create more immediate opportunities for active living, the partnership initiated a senior walking program, a bicycle refurbishment and giveaway program, and community bicycle-riding events, and led a social-marketing campaign that emphasized simple lifestyle changes. Get Active Orlando influenced adoption of public policies supporting active living in Orlando, including the Downtown Transportation Plan, Streetscape Guidelines, Design Standards Review Checklist, and growth management policies. Establishment of the Mayor's Advisory Council on Active Living is testament to the heightened significance of active living in Orlando. Initial assessment data served as a strong platform for policy change. Creating connections across disciplines including land-use planning, transportation, public health, and economic development allowed GAO to secure substantial policy change to influence design of the built environment. Engaging community members, including youth, as leaders was an important factor in program success. The physical environment in Orlando's Community Redevelopment Area is beginning to change as a reflection of a new policy framework designed to support active living.

  1. The change in body stressed to relaxed body through breathing, visualization and a protective environment together

    Directory of Open Access Journals (Sweden)

    Evelyn I. Rodríguez Morrill

    2009-11-01

    Full Text Available This work shows several ways to meet and relax the body through personal knowledge and techniques encounter with nature. Modern life and fast, the constant pressure from childhood to adulthood, in the modes of interaction between individuals and groups, they lead to construction of bodies that reflect emotional anatomy visible loss of balance, contractures, inflammation, multiple imbalances by lack of knowledge and awareness especially being in the world fully, the person has moved away from its ecological relationship with itself and the environment. Methods are shown to positively change a condition of constant stress and chronic discomfort, a learned condition of physical and psychological wellbeing, with a series of movements, recovering the body through exercise, to tend to personal balance, obtaining a positive relationship with the environment and the people attended. The proposal starts promoting new habits that can be saved in consciousness. Partly, mainly of breath, alignment with the music and the environment and personal and group work

  2. Impact of climate change on the domestic indoor environment and associated health risks in the UK.

    Science.gov (United States)

    Vardoulakis, Sotiris; Dimitroulopoulou, Chrysanthi; Thornes, John; Lai, Ka-Man; Taylor, Jonathon; Myers, Isabella; Heaviside, Clare; Mavrogianni, Anna; Shrubsole, Clive; Chalabi, Zaid; Davies, Michael; Wilkinson, Paul

    2015-12-01

    There is growing evidence that projected climate change has the potential to significantly affect public health. In the UK, much of this impact is likely to arise by amplifying existing risks related to heat exposure, flooding, and chemical and biological contamination in buildings. Identifying the health effects of climate change on the indoor environment, and risks and opportunities related to climate change adaptation and mitigation, can help protect public health. We explored a range of health risks in the domestic indoor environment related to climate change, as well as the potential health benefits and unintended harmful effects of climate change mitigation and adaptation policies in the UK housing sector. We reviewed relevant scientific literature, focusing on housing-related health effects in the UK likely to arise through either direct or indirect mechanisms of climate change or mitigation and adaptation measures in the built environment. We considered the following categories of effect: (i) indoor temperatures, (ii) indoor air quality, (iii) indoor allergens and infections, and (iv) flood damage and water contamination. Climate change may exacerbate health risks and inequalities across these categories and in a variety of ways, if adequate adaptation measures are not taken. Certain changes to the indoor environment can affect indoor air quality or promote the growth and propagation of pathogenic organisms. Measures aimed at reducing greenhouse gas emissions have the potential for ancillary public health benefits including reductions in health burdens related heat and cold, indoor exposure to air pollution derived from outdoor sources, and mould growth. However, increasing airtightness of dwellings in pursuit of energy efficiency could also have negative effects by increasing concentrations of pollutants (such as PM2.5, CO and radon) derived from indoor or ground sources, and biological contamination. These effects can largely be ameliorated by mechanical

  3. Climate change: Its possible impact on the environment and the people of northern regions

    International Nuclear Information System (INIS)

    Roots, F.

    1993-01-01

    A detailed overview is presented of the possible impacts of climate change on the Arctic environment, ecosystems, and human activities. The extent of global climate change is examined through the use of historical and paleoclimatologic records of temperature and stratospheric ozone. The effects of precipitation distribution and airborne particulates on climate change are also outlined. Changes in the Arctic are then examined, with an explanation of why global change in the Arctic is likely to be exaggerated. Likely scenarios of Arctic climate change involve milder winter temperatures, wetter and cloudier summers, more stormy weather and snowfall, greater variability in regional weather patterns, and dramatic changes in the extent of sea ice. Biological responses of wetland, northern forest, tundra, Arctic desert, below-ground, and marine ecosystems are assessed. Features of northern and Arctic ecosystems that may be particularly vulnerable to climate change are noted. Finally, the impacts of climate change on traditional activities and lifestyles, resource management and harvesting, agriculture, forestry, mining and fossil-fuel development, offshore operations, and human infrastructures are summarized. 5 figs

  4. Spatial memory extinction: a c-Fos protein mapping study.

    Science.gov (United States)

    Méndez-Couz, M; Conejo, N M; Vallejo, G; Arias, J L

    2014-03-01

    While the neuronal basis of spatial memory consolidation has been thoroughly studied, the substrates mediating the process of extinction remain largely unknown. This study aimed to evaluate the functional contribution of selected brain regions during the extinction of a previously acquired spatial memory task in the Morris water maze. For that purpose, we used adult male Wistar rats trained in a spatial reference memory task. Learning-related changes in c-Fos inmunoreactive cells after training were evaluated in cortical and subcortical regions. Results show that removal of the hidden platform in the water maze induced extinction of the previously reinforced escape behavior after 16 trials, without spontaneous recovery 24h later. Extinction was related with significantly higher numbers of c-Fos positive nuclei in amygdala nuclei and prefrontal cortex. On the other hand, the lateral mammillary bodies showed higher number of c-Fos positive cells than the control group. Therefore, in contrast with the results obtained in studies of classical conditioning, we show the involvement of diencephalic structures mediating this kind of learning. In summary, our findings suggest that medial prefrontal cortex, the amygdala complex and diencephalic structures like the lateral mammillary nuclei are relevant for the extinction of spatial memory. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. A fundamental role for context in instrumental learning and extinction.

    Science.gov (United States)

    Bouton, Mark E; Todd, Travis P

    2014-05-01

    The purpose of this article is to review recent research that has investigated the effects of context change on instrumental (operant) learning. The first part of the article discusses instrumental extinction, in which the strength of a reinforced instrumental behavior declines when reinforcers are withdrawn. The results suggest that extinction of either simple or discriminated operant behavior is relatively specific to the context in which it is learned: As in prior studies of Pavlovian extinction, ABA, ABC, and AAB renewal effects can all be observed. Further analysis supports the idea that the organism learns to refrain from making a specific response in a specific context, or in more formal terms, an inhibitory context-response association. The second part of the article then discusses research suggesting that the context also controls instrumental behavior before it is extinguished. Several experiments demonstrate that a context switch after either simple or discriminated operant training causes a decrement in the strength of the response. Over a range of conditions, the animal appears to learn a direct association between the context and the response. Under some conditions, it can also learn a hierarchical representation of context and the response-reinforcer relation. Extinction is still more context-specific than conditioning, as indicated by ABC and AAB renewal. Overall, the results establish that the context can play a significant role in both the acquisition and extinction of operant behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Individual variation in working memory is associated with fear extinction performance.

    Science.gov (United States)

    Stout, Daniel M; Acheson, Dean T; Moore, Tyler M; Gur, Ruben C; Baker, Dewleen G; Geyer, Mark A; Risbrough, Victoria B

    2018-03-01

    PTSD has been associated consistently with abnormalities in fear acquisition and extinction learning and retention. Fear acquisition refers to learning to discriminate between threat and safety cues. Extinction learning reflects the formation of a new inhibitory-memory that competes with a previously learned threat-related memory. Adjudicating the competition between threat memory and the new inhibitory memory during extinction may rely, in part, on cognitive processes such as working memory (WM). Despite significant shared neural circuits and signaling pathways the relationship between WM, fear acquisition, and extinction is poorly understood. Here, we analyzed data from a large sample of healthy Marines who underwent an assessment battery including tests of fear acquisition, extinction learning, and WM (N-back). Fear potentiated startle (FPS), fear expectancy ratings, and self-reported anxiety served as the primary dependent variables. High WM ability (N = 192) was associated with greater CS + fear inhibition during the late block of extinction and greater US expectancy change during extinction learning compared to individuals with low WM ability (N = 204). WM ability was not associated with magnitude of fear conditioning/expression. Attention ability was unrelated to fear acquisition or extinction supporting specificity of WM associations with extinction. These results support the conclusion that individual differences in WM may contribute to regulating fear responses. Copyright © 2018. Published by Elsevier Ltd.

  7. Plio-Pleistocene climate change and geographic heterogeneity in plant diversity-environment relationships

    DEFF Research Database (Denmark)

    Svenning, J.-C.; Normand, Signe; Skov, Flemming

    2009-01-01

    Plio-Pleistocene climate change may have induced geographic heterogeneity in plant species richness-environment relationships in Europe due to greater in situ species survival and speciation rates in southern Europe. We formulate distinct hypotheses on how Plio-Pleistocene climate change may have...... affected richness-topographic heterogeneity and richness-water-energy availability relationships, causing steeper relationships in southern Europe. We investigated these hypotheses using data from Atlas Florae Europaeae on the distribution of 3069 species and geographically weighted regression (GWR). Our...... analyses showed that plant species richness generally increased with topographic heterogeneity (ln-transformed altitudinal range) and actual evapotranspiration (AET). We also found evidence for strong geographic heterogeneity in the species richness-environment relationship, with a greater increase...

  8. Chaos and the (un)predictability of evolution in a changing environment.

    Science.gov (United States)

    Rego-Costa, Artur; Débarre, Florence; Chevin, Luis-Miguel

    2018-02-01

    Among the factors that may reduce the predictability of evolution, chaos, characterized by a strong dependence on initial conditions, has received much less attention than randomness due to genetic drift or environmental stochasticity. It was recently shown that chaos in phenotypic evolution arises commonly under frequency-dependent selection caused by competitive interactions mediated by many traits. This result has been used to argue that chaos should often make evolutionary dynamics unpredictable. However, populations also evolve largely in response to external changing environments, and such environmental forcing is likely to influence the outcome of evolution in systems prone to chaos. We investigate how a changing environment causing oscillations of an optimal phenotype interacts with the internal dynamics of an eco-evolutionary system that would be chaotic in a constant environment. We show that strong environmental forcing can improve the predictability of evolution by reducing the probability of chaos arising, and by dampening the magnitude of chaotic oscillations. In contrast, weak forcing can increase the probability of chaos, but it also causes evolutionary trajectories to track the environment more closely. Overall, our results indicate that, although chaos may occur in evolution, it does not necessarily undermine its predictability. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  9. Predicting extinction rates in stochastic epidemic models

    International Nuclear Information System (INIS)

    Schwartz, Ira B; Billings, Lora; Dykman, Mark; Landsman, Alexandra

    2009-01-01

    We investigate the stochastic extinction processes in a class of epidemic models. Motivated by the process of natural disease extinction in epidemics, we examine the rate of extinction as a function of disease spread. We show that the effective entropic barrier for extinction in a susceptible–infected–susceptible epidemic model displays scaling with the distance to the bifurcation point, with an unusual critical exponent. We make a direct comparison between predictions and numerical simulations. We also consider the effect of non-Gaussian vaccine schedules, and show numerically how the extinction process may be enhanced when the vaccine schedules are Poisson distributed

  10. Biodiversity, extinctions, and evolution of ecosystems with shared resources

    Science.gov (United States)

    Kozlov, Vladimir; Vakulenko, Sergey; Wennergren, Uno

    2017-03-01

    We investigate the formation of stable ecological networks where many species share the same resource. We show that such a stable ecosystem naturally occurs as a result of extinctions. We obtain an analytical relation for the number of coexisting species, and we find a relation describing how many species that may become extinct as a result of a sharp environmental change. We introduce a special parameter that is a combination of species traits and resource characteristics used in the model formulation. This parameter describes the pressure on the system to converge, by extinctions. When that stress parameter is large, we obtain that the species traits are concentrated at certain values. This stress parameter is thereby a parameter that determines the level of final biodiversity of the system. Moreover, we show that the dynamics of this limit system can be described by simple differential equations.

  11. Selection in a subdivided population with local extinction and recolonization.

    Science.gov (United States)

    Cherry, Joshua L

    2003-01-01

    In a subdivided population, local extinction and subsequent recolonization affect the fate of alleles. Of particular interest is the interaction of this force with natural selection. The effect of selection can be weakened by this additional source of stochastic change in allele frequency. The behavior of a selected allele in such a population is shown to be equivalent to that of an allele with a different selection coefficient in an unstructured population with a different size. This equivalence allows use of established results for panmictic populations to predict such quantities as fixation probabilities and mean times to fixation. The magnitude of the quantity N(e)s(e), which determines fixation probability, is decreased by extinction and recolonization. Thus deleterious alleles are more likely to fix, and advantageous alleles less likely to do so, in the presence of extinction and recolonization. Computer simulations confirm that the theoretical predictions of both fixation probabilities and mean times to fixation are good approximations. PMID:12807797

  12. Changes of radiological situation of Polish environment in 10 years period after Chernobyl accident

    International Nuclear Information System (INIS)

    Jagielak, J.; Biernacka, M.; Grabowski, D.; Henschke, J.

    1996-01-01

    The content of natural and artificial radioisotopes in environment in Poland before and after Chernobyl accident was analyzed. The methods used in radiation monitoring in Poland and results of these measurements in the period 1986-1996 were presented. Since the Chernobyl accident changes of contamination of soils, southern Baltic sea water, other surface waters, deposits in Baltic sea, rivers and lakes in Poland were observed. Also concentration of radioisotopes in foodstuffs: mushrooms, fruits, meat, milk, eggs was described

  13. Changes to the school food and physical activity environment after guideline implementation in British Columbia, Canada

    OpenAIRE

    Watts, Allison W; Mâsse, Louise C; Naylor, Patti-Jean

    2014-01-01

    Background High rates of childhood obesity have generated interest among policy makers to improve the school food environment and increase students’ levels of physical activity. The purpose of this study was to examine school-level changes associated with implementation of the Food and Beverage Sales in Schools (FBSS) and Daily Physical Activity (DPA) guidelines in British Columbia, Canada. Methods Elementary and middle/high school principals completed a survey on the school food and physical...

  14. Thermal changes of the environment and their influence on reinforced concrete structures

    Science.gov (United States)

    Fojtik, R.; Cajka, R.

    2018-04-01

    The thermal expansion of concrete elements concerns both monolithic and prefabricated structures. Inappropriate design of dilation segments may cause minor but even larger failures. Critical environment factors are temperature-changing operations, such as unheated underground garages, where temperature fluctuations may occur depending on the exterior conditions. This paper numerically and experimentally analyses the thermal deformation of selected girders in the underground garages and the consequent structure failures, their causes, possible prevention and appropriate remediation.

  15. The development and change study of cost accounting in the IT environment

    Institute of Scientific and Technical Information of China (English)

    Zilian Li; Qiumei Hu

    2015-01-01

    Relative to costs of computerized accounting, the cost accounting information further to get rid of the shackles of artificial accounting, reflecting a pure information management thinking, which contains a richer content, and traditional cost accounting theory a profound impact on the system. Clear understanding of the environment in the IT development process cost accounting will help us actively to promote cost accounting change, innovation and development.

  16. Global warming and extinctions of endemic species from biodiversity hotspots.

    Science.gov (United States)

    Jay R. Malcolm; Canran Liu; Ronald P. Neilson; Lara Hansen; Lee. Hannah

    2006-01-01

    Global warming is a key threat to biodiversity, but few researchers have assessed the magnitude of this threat at the global scale. We used major vegetation types (biomes) as proxies for natural habitats and, based on projected future biome distributions under doubled-C02 climates, calculated changes in habitat areas and associated extinctions of...

  17. Climate change damage functions in LCA – (1) from global warming potential to natural environment damages

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Hauschild, Michael Zwicky; Bagger Jørgensen, Rikke

    Energy use often is the most significant contributor to the impact category ‘global warming’ in life cycle impact assessment. However, the potential global warming effects on the climate at regional level and consequential effects on the natural environment are not thoroughly described within LCA...... methodology. The current scientific understanding of the extent of climate change impacts is limited due to the immense complexity of the multi-factorial environmental changes and unknown adaptive capacities at process, species and ecosystem level. In the presentation we argue that the global warming impacts...

  18. Porter's generic strategies, discontinuous environments, and performance: a longitudinal study of changing strategies in the hospital industry.

    Science.gov (United States)

    Lamont, B T; Marlin, D; Hoffman, J J

    1993-12-01

    Changes in generic strategies in response to discontinuous environments have been relatively ignored in the management literature. This study reports an examination of the relationships between Porter's (1980) generic strategies, discontinuous environments, and performance. Archival data for 1984 and 1988 were collected for 172 acute care hospitals in Florida in order to test these relationships. To examine fully the performance impact of changes in strategy in a discontinuous environment, a longitudinal research design that identified a firm's strategy at two points in time, 1984 and 1988, was used. Results indicate that firms with a proper strategy environment fit performed the highest, firms that did not change their strategy had no change in performance, and firms that changed their strategy toward a proper strategy environment showed an increase in performance. Findings support the notion that hospitals with appropriate strategy-environment combinations will exhibit higher performance.

  19. A Governing Framework for Climate Change Adaptation in the Built Environment

    Directory of Open Access Journals (Sweden)

    Daniel A. Mazmanian

    2013-12-01

    Full Text Available Developing an approach to governing adaptation to climate change is severely hampered by the dictatorship of the present when the needs of future generations are inadequately represented in current policy making. We posit this problem as a function of the attributes of adaptation policy making, including deep uncertainty and nonstationarity, where past observations are not reliable predictors of future outcomes. Our research links organizational decision-making attributes with adaptation decision making and identifies cases in which adaptation actions cause spillovers, free riding, and distributional impacts. We develop a governing framework for adaptation that we believe will enable policy, planning, and major long-term development decisions to be made appropriately at all levels of government in the face of the deep uncertainty and nonstationarity caused by climate change. Our framework requires that approval of projects with an expected life span of 30 years or more in the built environment include minimum building standards that integrate forecasted climate change impacts from the Intergovernmental Panel on Climate Change (IPCC intermediate scenario. The intermediate IPCC scenario must be downscaled to include local or regional temperature, water availability, sea level rise, susceptibility to forest fires, and human habitation impacts to minimize climate-change risks to the built environment. The minimum standard is systematically updated every six years to facilitate learning by formal and informal organizations. As a minimum standard, the governance framework allows jurisdictions to take stronger actions to increase their climate resilience and thus maintain system flexibility.

  20. VECTORS of change in the marine environment: Ecosystem and economic impacts and management implications

    Science.gov (United States)

    Austen, M. C.; Crowe, T. P.; Elliott, M.; Paterson, D. M.; Peck, M. A.; Piraino, S.

    2018-02-01

    Human use of the European marine environment is increasing and diversifying. This is creating new mechanisms for human induced-changes in marine life which need to be understood and quantified as well as the impact of these changes on ecosystems, their structures (e.g. biodiversity) and functioning (e.g. productivity), and the social and economic consequences that arise. The current and emerging pressures are multiple and interacting, arising, for example, from transport, platforms for renewable and non-renewable energy, exploitation of living and non-living resources, agricultural and industrial discharges, together with wider environmental changes (including climate change). Anticipating the future consequences of these pressures and vectors of change for marine life and of adaptation and mitigation measures (such as the introduction of new technologies and structures, new ballast water practices, ocean and offshore wind energy devices and new fishing strategies) is a prerequisite to the development and implementation of strategies, policies and regulations to manage the marine environment, such as the IMO Convention on ballast water management and the EU Maritime Policy and Marine Strategy Framework Directive.

  1. 3. Neural changes in different gravity and ecophysiological environments - A survey

    Science.gov (United States)

    Slenzka, K.

    Neural changes or neuronal plasticity occur after and during different stimulations and inputs in general. Gravity is one major input to the brain transferred from the vestibular system. However, often also direct effects of gravity on the cellular level are discussed. Our group was investigating the influence of different gravity environments on a large variety of neuronal enzymes in the developing fish brain. Long-term space travel or bases on Moon and Mars will have to deal not only with neural changes based on the different gravity environment, but also with potential negative or even toxic changes in the respective life support system. Our goal is now to identify reported enzyme activity changes in the brain based for example on potential toxic drugs or endocrine disruptors in combination with gravity induced changes. In this paper a survey will be undertaken discussing recent results obtained in ecotoxicology, gravitational biology combined with new data from our group regarding potential differences in brain glucose-6-phosphate dehydrogenase of medaka and zebrafish.

  2. Diurnal changes in epidermal UV transmittance of plants in naturally high UV environments.

    Science.gov (United States)

    Barnes, Paul W; Flint, Stephan D; Slusser, James R; Gao, Wei; Ryel, Ronald J

    2008-06-01

    Studies were conducted on three herbaceous plant species growing in naturally high solar UV environments in the subalpine of Mauna Kea, Hawaii, USA, to determine if diurnal changes in epidermal UV transmittance (T(UV)) occur in these species, and to test whether manipulation of the solar radiation regime could alter these diurnal patterns. Additional field studies were conducted at Logan, Utah, USA, to determine if solar UV was causing diurnal T(UV) changes and to evaluate the relationship between diurnal changes in T(UV) and UV-absorbing pigments. Under clear skies, T(UV), as measured with a UV-A-pulse amplitude modulation fluorometer for leaves of Verbascum thapsus and Oenothera stricta growing in native soils and Vicia faba growing in pots, was highest at predawn and sunset and lowest at midday. These patterns in T(UV) closely tracked diurnal changes in solar radiation and were the result of correlated changes in fluorescence induced by UV-A and blue radiation but not photochemical efficiency (F(v)/F(m)) or initial fluorescence yield (F(o)). The magnitude of the midday reduction in T(UV) was greater for young leaves than for older leaves of Verbascum. Imposition of artificial shade eliminated the diurnal changes in T(UV) in Verbascum, but reduction in solar UV had no effect on diurnal T(UV) changes in Vicia. In Vicia, the diurnal changes in T(UV) occurred without detectable changes in the concentration of whole-leaf UV-absorbing compounds. Results suggest that plants actively control diurnal changes in UV shielding, and these changes occur in response to signals other than solar UV; however, the underlying mechanisms responsible for rapid changes in T(UV) remain unclear.

  3. Changes in mental state associated with prison environments: a systematic review.

    Science.gov (United States)

    Walker, J; Illingworth, C; Canning, A; Garner, E; Woolley, J; Taylor, P; Amos, T

    2014-06-01

    To develop an understanding of the stability of mental health during imprisonment through review of existing research evidence relating physical prison environment to mental state changes in prisoners. A systematic literature search was conducted looking at changes in mental state and how this related to various aspects of imprisonment and the prison environment. Fifteen longitudinal studies were found, and from these, three broad themes were delineated: being imprisoned and aspects of the prison regime; stage of imprisonment and duration of sentence; and social density. Reception into prison results in higher levels of psychiatric symptoms that seem to improve over time; otherwise, duration of imprisonment appears to have no significant impact on mental health. Regardless of social density, larger prisons are associated with poorer mental state, as are extremes of social density. There are large gaps in the literature relating prison environments to changes in mental state; in particular, high-quality longitudinal studies are needed. Existing research suggests that although entry to prison may be associated with deterioration in mental state, it tends to improve with time. Furthermore, overcrowding, ever more likely as prison populations rise, is likely to place a particular burden on mental health services. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Complexity in organizations and environment - adaptive changes and adaptive decision-making

    Directory of Open Access Journals (Sweden)

    Robert Fabac

    2010-07-01

    Full Text Available The features of complexity are ever more present in modern organizations and in environments in which they operate, trying to survive and be as competitive as possible. In the processes of, the so-called emergence, the formal organizational structure, designed purposefully and with a plan, is going through a change due to complexity and the need for adaptation. As a result, there is a variety of new informal groups. At the same time, the intended structural changes and business process changes occur because of the perception that the leadership and senior organizational management have of the strategic situation. Managers in modern organizations often use business intelligence (BI systems when making important business decisions. These systems offer support to the decision-making by gathering and processing relevant data and information about the company performance, but also about the data on conditions in close and remote environment. A modern company is characterized by the complex adaptive system, but the environment in which it operates together with other business subjects (agents is also complex. Consequently, the requirements for appropriate or optimal decisions and successfully completed activities are hard to meet. Given that expected future events and circumstances often occur in nonlinear mechanisms, the decisions made by following the models of traditional predicting and planning are not satisfactory. This calls for new approaches to decision making and acting.

  5. Non-Equilibrium Relations for Bounded Rational Decision-Making in Changing Environments

    Directory of Open Access Journals (Sweden)

    Jordi Grau-Moya

    2017-12-01

    Full Text Available Living organisms from single cells to humans need to adapt continuously to respond to changes in their environment. The process of behavioural adaptation can be thought of as improving decision-making performance according to some utility function. Here, we consider an abstract model of organisms as decision-makers with limited information-processing resources that trade off between maximization of utility and computational costs measured by a relative entropy, in a similar fashion to thermodynamic systems undergoing isothermal transformations. Such systems minimize the free energy to reach equilibrium states that balance internal energy and entropic cost. When there is a fast change in the environment, these systems evolve in a non-equilibrium fashion because they are unable to follow the path of equilibrium distributions. Here, we apply concepts from non-equilibrium thermodynamics to characterize decision-makers that adapt to changing environments under the assumption that the temporal evolution of the utility function is externally driven and does not depend on the decision-maker’s action. This allows one to quantify performance loss due to imperfect adaptation in a general manner and, additionally, to find relations for decision-making similar to Crooks’ fluctuation theorem and Jarzynski’s equality. We provide simulations of several exemplary decision and inference problems in the discrete and continuous domains to illustrate the new relations.

  6. Local Fitness Landscapes Predict Yeast Evolutionary Dynamics in Directionally Changing Environments.

    Science.gov (United States)

    Gorter, Florien A; Aarts, Mark G M; Zwaan, Bas J; de Visser, J Arjan G M

    2018-01-01

    The fitness landscape is a concept that is widely used for understanding and predicting evolutionary adaptation. The topography of the fitness landscape depends critically on the environment, with potentially far-reaching consequences for evolution under changing conditions. However, few studies have assessed directly how empirical fitness landscapes change across conditions, or validated the predicted consequences of such change. We previously evolved replicate yeast populations in the presence of either gradually increasing, or constant high, concentrations of the heavy metals cadmium (Cd), nickel (Ni), and zinc (Zn), and analyzed their phenotypic and genomic changes. Here, we reconstructed the local fitness landscapes underlying adaptation to each metal by deleting all repeatedly mutated genes both by themselves and in combination. Fitness assays revealed that the height, and/or shape, of each local fitness landscape changed considerably across metal concentrations, with distinct qualitative differences between unconditionally (Cd) and conditionally toxic metals (Ni and Zn). This change in topography had particularly crucial consequences in the case of Ni, where a substantial part of the individual mutational fitness effects changed in sign across concentrations. Based on the Ni landscape analyses, we made several predictions about which mutations had been selected when during the evolution experiment. Deep sequencing of population samples from different time points generally confirmed these predictions, demonstrating the power of landscape reconstruction analyses for understanding and ultimately predicting evolutionary dynamics, even under complex scenarios of environmental change. Copyright © 2018 by the Genetics Society of America.

  7. Open-path, closed-path and reconstructed aerosol extinction at a rural site.

    Science.gov (United States)

    Gordon, Timothy D; Prenni, Anthony J; Renfro, James R; McClure, Ethan; Hicks, Bill; Onasch, Timothy B; Freedman, Andrew; McMeeking, Gavin R; Chen, Ping

    2018-04-09

    The Handix Scientific Open-Path Cavity Ringdown Spectrometer (OPCRDS) was deployed during summer 2016 in Great Smoky Mountains National Park (GRSM). Extinction coefficients from the relatively new OPCRDS and from a more well-established extinction instrument agreed to within 7%. Aerosol hygroscopic growth (f(RH)) was calculated from the ratio of ambient extinction measured by the OPCRDS to dry extinction measured by a closed-path extinction monitor (Aerodyne's Cavity Attenuated Phase Shift Particulate Matter Extinction Monitor, CAPS PMex). Derived hygroscopicity (RH 1995 at the same site and time of year, which is noteworthy given the decreasing trend for organics and sulfate in the eastern U.S. However, maximum f(RH) values in 1995 were less than half as large as those recorded in 2016-possibly due to nephelometer truncation losses in 1995. Two hygroscopicity parameterizations were investigated using high time resolution OPCRDS+CAPS PMex data, and the K ext model was more accurate than the γ model. Data from the two ambient optical instruments, the OPCRDS and the open-path nephelometer, generally agreed; however, significant discrepancies between ambient scattering and extinction were observed, apparently driven by a combination of hygroscopic growth effects, which tend to increase nephelometer truncation losses and decrease sensitivity to the wavelength difference between the two instruments as a function of particle size. There was not a statistically significant difference in the mean reconstructed extinction values obtained from the original and the revised IMPROVE (Interagency Monitoring of Protected Visual Environments) equations. On average IMPROVE reconstructed extinction was ~25% lower than extinction measured by the OPCRDS, which suggests that the IMPROVE equations and 24-hr aerosol data are moderately successful in estimating current haze levels at GRSM. However, this conclusion is limited by the coarse temporal resolution and the low dynamic range of

  8. Extinction Coefficient of Gold Nanostars.

    Science.gov (United States)

    de Puig, Helena; Tam, Justina O; Yen, Chun-Wan; Gehrke, Lee; Hamad-Schifferli, Kimberly

    2015-07-30

    Gold nanostars (NStars) are highly attractive for biological applications due to their surface chemistry, facile synthesis and optical properties. Here, we synthesize NStars in HEPES buffer at different HEPES/Au ratios, producing NStars of different sizes and shapes, and therefore varying optical properties. We measure the extinction coefficient of the synthesized NStars at their maximum surface plasmon resonances (SPR), which range from 5.7 × 10 8 to 26.8 × 10 8 M -1 cm -1 . Measured values correlate with those obtained from theoretical models of the NStars using the discrete dipole approximation (DDA), which we use to simulate the extinction spectra of the nanostars. Finally, because NStars are typically used in biological applications, we conjugate DNA and antibodies to the NStars and calculate the footprint of the bound biomolecules.

  9. Dinasour extinction and volcanic activity

    Science.gov (United States)

    Gledhill, J. A.

    There is at present some controversy about the reason for the mass extinction of dinosaurs and other forms of life at the end of the Cretaceous. A suggestion by Alvarez et al. [1980] that this was due to the collision of the earth with a meteorite 10 km or so in diameter has excited considerable interest [Silver and Schultz, 1982] and also some criticism [Stanley, 1984]. A recent publication [Wood, 1984] describing the catastrophic effects of a relatively minor lava flow in Iceland suggests that intense volcanic activity could have played a large part in the extinctions. In this letter it is pointed out that the Deccan lava flows in India took place in the appropriate time and may well have been of sufficient magnitude to be a major factor in the Cretaceous-Tertiary (C-T) boundary catastrophe.

  10. Body Size Preference of Marine Animals in Relation to Extinction Selectivity

    Science.gov (United States)

    Sriram, A.; Idgunji, S.; Heim, N. A.; Payne, J.

    2014-12-01

    Our project encompasses an extremely specific aspect in relation to the five mass extinctions in geologic history. We asked ourselves whether larger or smaller body sizes would be better suited for surviving a mass extinction. To conduct research for our project, we used the body sizes of 17,172 marine animal genera as our primary data. These animals include echinoderms, arthropods, chordates, mollusks, and brachiopods. These creatures are perfect model organisms in terms of finding data on them because they have an excellent fossil record, and are well documented. We focused on the mean body size of these animals before and after each of the five mass extinctions (end-Ordovician, Late Devonian, end-Permian, end-Triassic, and end-Cretaceous). Our hypothesis was that the average biovolume of animals increased after each of the extinctions, with the mean size being greater after than it was before. Our size data is from the Ellis & Messina Catalogue of Ostracoda and the Treatise on Invertebrate Paleontology. We obtained stratigraphic range data The Treatise and Sepkoski (2002). In our analyses, we compared the mean size of the different animal genera before and after each extinction event. We further partitioned size change across mass extinction boundaries into three categories: the surviving genera, the extinct genera, and the newly originating genera that came about after the extinction. According to our analyses, the mean sizes did not change significantly from the genera living during the stages before the extinctions and after the extinctions. From our results, we can assume that there were not enough major increases in the overall volume of the organisms to warrant a definite conclusion that extinctions lead to larger body sizes. Further support for our findings came from the T-tests in our R code. Only the Cretaceous period showed true evidence for size changing because of the extinction; in this case, the mean size decreased. T-tests for the Cretaceous

  11. Optimising Extinction of Conditioned Disgust.

    Science.gov (United States)

    Bosman, Renske C; Borg, Charmaine; de Jong, Peter J

    2016-01-01

    Maladaptive disgust responses are tenacious and resistant to exposure-based interventions. In a similar vein, laboratory studies have shown that conditioned disgust is relatively insensitive to Conditioned Stimulus (CS)-only extinction procedures. The relatively strong resistance to extinction might be explained by disgust's adaptive function to motivate avoidance from contamination threats (pathogens) that cannot be readily detected and are invisible to the naked eye. Therefore, the mere visual presentation of unreinforced disgust eliciting stimuli might not be sufficient to correct a previously acquired threat value of the CS+. Following this, the current study tested whether the efficacy of CS-only exposure can be improved by providing additional safety information about the CS+. For the CSs we included two neutral items a pea soup and a sausage roll, whereas for the Unconditioned Stimulus (US) we used one video clip of a woman vomiting and a neutral one about glass blowing. The additional safety information was conveyed by allowing actual contact with the CS+ or by observing an actress eating the food items representing the CS+. When additional safety information was provided via allowing direct contact with the CS+, there was a relatively strong post-extinction increase in participants' willingness-to-eat the CS+. This beneficial effect was still evident at one-week follow up. Also self-reported disgust was lower at one-week follow up when additional safety information was provided. The current findings help explain why disgust is relatively insensitive to CS-only extinction procedures, and provide helpful starting points to improve interventions that are aimed to reduce distress in disgust-related psychopathology.

  12. Optimising Extinction of Conditioned Disgust.

    Directory of Open Access Journals (Sweden)

    Renske C Bosman

    Full Text Available Maladaptive disgust responses are tenacious and resistant to exposure-based interventions. In a similar vein, laboratory studies have shown that conditioned disgust is relatively insensitive to Conditioned Stimulus (CS-only extinction procedures. The relatively strong resistance to extinction might be explained by disgust's adaptive function to motivate avoidance from contamination threats (pathogens that cannot be readily detected and are invisible to the naked eye. Therefore, the mere visual presentation of unreinforced disgust eliciting stimuli might not be sufficient to correct a previously acquired threat value of the CS+. Following this, the current study tested whether the efficacy of CS-only exposure can be improved by providing additional safety information about the CS+. For the CSs we included two neutral items a pea soup and a sausage roll, whereas for the Unconditioned Stimulus (US we used one video clip of a woman vomiting and a neutral one about glass blowing. The additional safety information was conveyed by allowing actual contact with the CS+ or by observing an actress eating the food items representing the CS+. When additional safety information was provided via allowing direct contact with the CS+, there was a relatively strong post-extinction increase in participants' willingness-to-eat the CS+. This beneficial effect was still evident at one-week follow up. Also self-reported disgust was lower at one-week follow up when additional safety information was provided. The current findings help explain why disgust is relatively insensitive to CS-only extinction procedures, and provide helpful starting points to improve interventions that are aimed to reduce distress in disgust-related psychopathology.

  13. Extinction Coefficient of Gold Nanostars

    OpenAIRE

    de Puig, Helena; Tam, Justina O.; Yen, Chun-Wan; Gehrke, Lee; Hamad-Schifferli, Kimberly

    2015-01-01

    Gold nanostars (NStars) are highly attractive for biological applications due to their surface chemistry, facile synthesis and optical properties. Here, we synthesize NStars in HEPES buffer at different HEPES/Au ratios, producing NStars of different sizes and shapes, and therefore varying optical properties. We measure the extinction coefficient of the synthesized NStars at their maximum surface plasmon resonances (SPR), which range from 5.7 × 108 to 26.8 × 108 M−1cm−1. Measured values correl...

  14. An examination of extratropical cyclone response to changes in baroclinicity and temperature in an idealized environment

    Science.gov (United States)

    Tierney, Gregory; Posselt, Derek J.; Booth, James F.

    2018-02-01

    The dynamics and precipitation in extratropical cyclones (ETCs) are known to be sensitive to changes in the cyclone environment, with increases in bulk water vapor and baroclinicity both leading to increases in storm strength and precipitation. Studies that demonstrate this sensitivity have commonly varied either the cyclone moisture or baroclinicity, but seldom both. In a changing climate, in which the near-surface equator to pole temperature gradient may weaken while the bulk water vapor content of the atmosphere increases, it is important to understand the relative response of ETC strength and precipitation to changes in both factors simultaneously. In this study, idealized simulations of ETC development are conducted in a moist environment using a model with a full suite of moist physics parameterizations. The bulk temperature (and water vapor content) and baroclinicity are systematically varied one at a time, then simultaneously, and the effect of these variations on the storm strength and precipitation is assessed. ETC intensity exhibits the well-documented response to changes in baroclinicity, with stronger ETCs forming in higher baroclinicity environments. However, increasing water vapor content produces non-monotonic changes in storm strength, in which storm intensity first increases with increasing environmental water vapor, then decreases above a threshold value. Examination of the storm geographic extent indicates cyclone size also decreases above a threshold value of bulk environmental temperature (and water vapor). Decrease in storm size is concomitant with an increase in the convective fraction of precipitation and a shift in the vertical distribution of latent heating. The results indicate the existence of at least two regimes for ETC development, each of which exhibit significantly different distributions of PV due to differences in timing and location of convective heating.

  15. Effects of a Context Shift and Multiple Context Extinction on Reactivity to Alcohol Cues

    Science.gov (United States)

    MacKillop, James; Lisman, Stephen A.

    2008-01-01

    Cue exposure treatment (CET) attempts to reduce the influence of conditioned substance cues on addictive behavior via prolonged cue exposure with response prevention (i.e., extinction), but has received only modest empirical support in clinical trials. This may be because extinction learning appears to be context dependent and a change in context may result in a return of conditioned responding (i.e., renewal), although this has received only limited empirical examination. The current study used a four-session laboratory analogue of CET to examine whether a change in context following three sessions of alcohol cue exposure with response prevention would result in renewal of conditioned responding. In addition, this study examined whether conducting extinction in multiple contexts would attenuate renewal of conditioned responding. In a one-way between-subjects design, 73 heavy drinkers (71% male) were randomized to three conditions: 1) single context extinction (extinction to alcohol cues in the same context for three sessions followed by a context shift at the fourth session); 2) multiple context extinction (extinction to alcohol cues in different contexts each day for all four sessions); and 3) pseudo-extinction control condition (exposure to neutral cues in the same context for three sessions followed by exposure to alcohol cues at the fourth session). The results revealed the predicted cue reactivity and extinction effects, but the hypotheses that a context shift would generate renewed cue reactivity and that multiple contexts would enhance extinction were not supported. Methodological aspects of the study and the need for parametric data on the context dependency of extinction to alcohol cues are discussed. PMID:18729687

  16. A Comparison of the Water Environment Policy of Europe and South Korea in Response to Climate Change

    Directory of Open Access Journals (Sweden)

    Heejung Kim

    2018-02-01

    Full Text Available Climate change not only increases the atmospheric temperature, but also changes the precipitation conditions and patterns, which can lead to an increase in the frequency of occurrence of natural disasters, such as flooding and drought. The Intergovernmental Panel on Climate Change (IPCC has reported fluctuations in the precipitation levels for each country from 1900 to 2005, based on global climate change, suggesting that environmental changes due to climate change manifest very differently based on the region. According to the results of studies that have been carried out recently, changes in the precipitation patterns based on climate change result in changes in the water environment, including alterations to the vegetation, land use, and river flow, while considerably influencing the rate of development of groundwater as well. In this study, the 3Is, which are the important variables of Ideas, Institutions, and Interests that are universal to the international field of political science, were used to comparatively analyze the water environment policies of South Korea and Europe. The first variable, Ideas, examined the influence of awareness on establishing the water environment policy in response to climate change. In particular, differences in the conceptual awareness of the water environment with regard to hyporheic zones were studied. The second variable, Institutions, examined the differences in the water environment policy within the national administration in response to climate change. The South Korean administration’s Ministry of Land, Infrastructure, and Transport and the Ministry of Environment were used in a case study. Finally, the results drawn from the third variable, i.e., Interests, for South Korea appear to differ from those of Europe, in terms of water environment policy. In this study, the water environment policy of South Korea was analyzed and compared to that of Europe in order to identify problems in South Korea

  17. The effect of fidelity: how expert behavior changes in a virtual reality environment.

    Science.gov (United States)

    Ioannou, Ioanna; Avery, Alex; Zhou, Yun; Szudek, Jacek; Kennedy, Gregor; O'Leary, Stephen

    2014-09-01

    We compare the behavior of expert surgeons operating on the "gold standard" of simulation-the cadaveric temporal bone-against a high-fidelity virtual reality (VR) simulation. We aim to determine whether expert behavior changes within the virtual environment and to understand how the fidelity of simulation affects users' behavior. Five expert otologists performed cortical mastoidectomy and cochleostomy on a human cadaveric temporal bone and a VR temporal bone simulator. Hand movement and video recordings were used to derive a range of measures, to facilitate an analysis of surgical technique, and to compare expert behavior between the cadaveric and simulator environments. Drilling time was similar across the two environments. Some measures such as total time and burr change count differed predictably due to the ease of switching burrs within the simulator. Surgical strokes were generally longer in distance and duration in VR, but these measures changed proportionally to cadaveric measures across the stages of the procedure. Stroke shape metrics differed, which was attributed to the modeling of burr behavior within the simulator. This will be corrected in future versions. Slight differences in drill interaction between a virtual environment and the real world can have measurable effects on surgical technique, particularly in terms of stroke length, duration, and curvature. It is important to understand these effects when designing and implementing surgical training programs based on VR simulation--and when improving the fidelity of VR simulators to facilitate use of a similar technique in both real and simulated situations. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  18. The influence of the WIC food package changes on the retail food environment in New Orleans.

    Science.gov (United States)

    Rose, Donald; O'Malley, Keelia; Dunaway, Lauren Futrell; Bodor, J Nicholas

    2014-01-01

    To examine the effect of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) food package changes on availability of healthy foods in small stores. Pre-post comparison group design with repeat in-store observations. New Orleans. Small stores (n = 102; 77% of total) were visited in 2009. Of these, 91% were observed again in 2010, including both WIC (n = 27) and non-WIC (n = 66) stores. The 2009 WIC food package changes to include healthier foods. Change in store availability of fruits, vegetables, lower-fat milks, whole wheat bread, and brown rice. Change in number of varieties and shelf length of fruits and vegetables. Difference-in-differences analysis using logit models for change in availability and regression models for change in number of varieties or shelf length. The WIC stores were more likely to improve availability of lower-fat milks than non-WIC stores (adjusted odds ratio, 5.0, 95% confidence interval, 1.2-21.0). An even greater relative improvement was seen with whole grains. The WIC stores showed a relative increase in number of varieties of fresh fruits (0.9 ± 0.3; P New Orleans. Similar changes throughout the country could have a significant impact on neighborhood food environments. Copyright © 2014 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  19. Rural Settlement Development and Environment Carrying Capacity Changes in Progo River Basin

    Directory of Open Access Journals (Sweden)

    Su Ritohardoyo

    2016-12-01

    Full Text Available Generally the broader rural settlement the heavier population pressure on agricultural land. It indicates that carrying capacity of the rural environment threatened lower. The spatial distribution of the threat in a river basin is quite important as one of the river basin management inputs. Therefore, this article aims at exposing result of research about influence rural population growth and rural settlement land changes to environment carrying capacity. This research was carried out in the rural area in Progo river basin consists 56 sub districts (34 sub districts part of Jawa Tengah Province, and 22 sub districts part of Yogyakarta Special Region. The whole sub districts are such as unit analysis, and research method is based on secondary data analysis. Several data consist Districts Region in Figure 1997 and 2003 (Temanggung, Magelang, Kulon Progo, Sleman and Bantul such as secondary data analysis. Data analysis employs of frequency and cross tabulation, statistics of regression and test. Result of the research shows that population growth of the rural areas in Progo river basin are about 0.72% annum; or the household growth about 3.15% annum as long as five years (1996-2003. Spatial distribution of the population growth in the upper part of the Progo river basin is higher than in the middle and lower part of the basin. The number proportion of farmer in every sub district area in this river basin have increased from 69.95% in 1997 to 70.81% in the year of 2003. It means that work opportunities broadening are still sluggish. However, the number proportion of farmers in the upper part of the Progo river basin is lower than in the middle and lower part of the basin. The rates of settlement land areas changes (0.32 ha/annum as long as five years (1997-2003 is not as fast as the rates of agricultural land areas changes (0.47 ha/annum. Spatial land settlement areas changes in the lower (6.1 ha/annum and middle parts (2.4 ha/annum faster than

  20. Reintroduction of locally extinct vertebrates impacts arid soil fungal communities.

    Science.gov (United States)

    Clarke, Laurence J; Weyrich, Laura S; Cooper, Alan

    2015-06-01

    Introduced species have contributed to extinction of native vertebrates in many parts of the world. Changes to vertebrate assemblages are also likely to alter microbial communities through coextinction of some taxa and the introduction of others. Many attempts to restore degraded habitats involve removal of exotic vertebrates (livestock and feral animals) and reintroduction of locally extinct species, but the impact of such reintroductions on microbial communities is largely unknown. We used high-throughput DNA sequencing of the fungal internal transcribed spacer I (ITS1) region to examine whether replacing exotic vertebrates with reintroduced native vertebrates led to changes in soil fungal communities at a reserve in arid central Australia. Soil fungal diversity was significantly different between dune and swale (interdune) habitats. Fungal communities also differed significantly between sites with exotic or reintroduced native vertebrates after controlling for the effect of habitat. Several fungal operational taxonomic units (OTUs) found exclusively inside the reserve were present in scats from reintroduced native vertebrates, providing a direct link between the vertebrate assemblage and soil microbial communities. Our results show that changes to vertebrate assemblages through local extinctions and the invasion of exotic species can alter soil fungal communities. If local extinction of one or several species results in the coextinction of microbial taxa, the full complement of ecological interactions may never be restored. © 2015 John Wiley & Sons Ltd.

  1. How Customer Facing Professionals Adapt to Changing Customer Needs in a Digital Environment: A Single Case Study

    Science.gov (United States)

    Hendriks, Stefan

    2017-01-01

    This qualitative single case study explored how customer facing professionals (CFPs) adapt to changing customer needs in a digital environment. This study focuses on: (1) Changing customer needs; (2) Competencies needed in a digital environment; (3) How they learn; and (4) What factors help or hinder their success. The site is a global Human…

  2. EU-China Cooperation In the Field of Energy, Environment and Climate Change

    Directory of Open Access Journals (Sweden)

    Pietro De Matteis

    2010-11-01

    Full Text Available The evolution of the energy market and the intrinsic worldwide scope of environmental threats, such as climate change, are two elements that have pushed the world towards shared approaches to global governance via bilateral institutions and international regimes. This article, with the aid of an institutionalist approach, presents the current status of the EU-China relationship, which is characterised by high institutionalisation, and it underlines how their bilateral cooperation has progressively focused on energy and climate change-related issues. In particular, the article sheds some light on the linkages between energy, environment and climate change and how these have created the basis for the upgrade of the EU-China bilateral relationship to its current level. To do so, it underlines some of the tools, the main frameworks and some of the key outcomes of their bilateral cooperation in these fields.

  3. Adaptation measures for climate change and the urban heat island in Japan's built environment

    International Nuclear Information System (INIS)

    Shimoda, Y.

    2003-01-01

    Climate change scenarios are discussed for Japan with clear implications drawn for the built environment in terms of increased temperatures of 4-5 o C, rising sea levels and subterranean water tables. Research on the impacts and adaptation measures for global warming in Japan is reviewed. One of the most significant impacts of climate change in Japan will exacerbate the existing heat island phenomenon in cities by absorbing increased solar radiation. This will lead to further increases in temperatures in an urban microclimate with negative implications for energy and water consumption, human health and discomfort, and local ecosystems. The current urban heat island phenomenon and its impacts are described. The relationships between climate change and urban heat island impacts are discussed. Potential adaptation measures to those impacts are also discussed and proposed. (author)

  4. THE MID-INFRARED EXTINCTION LAW AND ITS VARIATION IN THE COALSACK NEBULA

    International Nuclear Information System (INIS)

    Wang Shu; Gao Jian; Jiang, B. W.; Chen Yang; Li Aigen

    2013-01-01

    In recent years, the wavelength dependence of interstellar extinction from the ultraviolet (UV) to the near- and mid-infrared (IR) has been studied extensively. Although it is well established that the UV/optical extinction law varies significantly among the different lines of sight, it is not clear how IR extinction varies among various environments. In this work, using the color-excess method and taking red giants as the extinction tracer, we determine interstellar extinction A λ in the four Spitzer/IRAC bands in [3.6], [4.5], [5.8], [8.0] μm (relative to A K s , extinction in the Two Micron All Sky Survey (2MASS) K s band at 2.16 μm) of the Coalsack nebula, a nearby starless dark cloud, based on the data obtained from the 2MASS and Spitzer/GLIMPSE surveys. We select five individual regions across the nebula that span a wide variety of physical conditions ranging from diffuse and translucent to dense environments, as traced by the visual extinction, the Spitzer/MIPS 24 μm emission, and CO emission. We find that A λ /A K s , mid-IR extinction relative to A K s , decreases from diffuse to dense environments, which may be explained in terms of ineffective dust growth in dense regions. The mean extinction (relative to A K s ) is calculated for the four IRAC bands as well and exhibits a flat mid-IR extinction law consistent with previous determinations for other regions. Extinction in the IRAC 4.5 μm band is anomalously high, much higher than that of the other three IRAC bands, and cannot be explained in terms of CO and CO 2 ice. Mid-IR extinction in the four IRAC bands has also been derived for four representative regions in the Coalsack Globule 2, which respectively exhibit strong ice absorption, moderate or weak ice absorption, and very weak or no ice absorption. The derived mid-IR extinction curves are all flat, with A λ /A K s increasing with the decrease of the 3.1 μm H 2 O ice absorption optical depth τ ice

  5. THE MID-INFRARED EXTINCTION LAW AND ITS VARIATION IN THE COALSACK NEBULA

    Energy Technology Data Exchange (ETDEWEB)

    Wang Shu; Gao Jian; Jiang, B. W.; Chen Yang [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Li Aigen, E-mail: shuwang@mail.bnu.edu.cn, E-mail: jiangao@bnu.edu.cn, E-mail: bjiang@bnu.edu.cn, E-mail: cheny@bnu.edu.cn, E-mail: lia@missouri.edu [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)

    2013-08-10

    In recent years, the wavelength dependence of interstellar extinction from the ultraviolet (UV) to the near- and mid-infrared (IR) has been studied extensively. Although it is well established that the UV/optical extinction law varies significantly among the different lines of sight, it is not clear how IR extinction varies among various environments. In this work, using the color-excess method and taking red giants as the extinction tracer, we determine interstellar extinction A{sub {lambda}} in the four Spitzer/IRAC bands in [3.6], [4.5], [5.8], [8.0] {mu}m (relative to A{sub K{sub s}}, extinction in the Two Micron All Sky Survey (2MASS) K{sub s} band at 2.16 {mu}m) of the Coalsack nebula, a nearby starless dark cloud, based on the data obtained from the 2MASS and Spitzer/GLIMPSE surveys. We select five individual regions across the nebula that span a wide variety of physical conditions ranging from diffuse and translucent to dense environments, as traced by the visual extinction, the Spitzer/MIPS 24 {mu}m emission, and CO emission. We find that A{sub {lambda}}/A{sub K{sub s}}, mid-IR extinction relative to A{sub K{sub s}}, decreases from diffuse to dense environments, which may be explained in terms of ineffective dust growth in dense regions. The mean extinction (relative to A{sub K{sub s}}) is calculated for the four IRAC bands as well and exhibits a flat mid-IR extinction law consistent with previous determinations for other regions. Extinction in the IRAC 4.5 {mu}m band is anomalously high, much higher than that of the other three IRAC bands, and cannot be explained in terms of CO and CO{sub 2} ice. Mid-IR extinction in the four IRAC bands has also been derived for four representative regions in the Coalsack Globule 2, which respectively exhibit strong ice absorption, moderate or weak ice absorption, and very weak or no ice absorption. The derived mid-IR extinction curves are all flat, with A{sub {lambda}}/A{sub K{sub s}} increasing with the decrease of the

  6. Changes in food and beverage environments after an urban corner store intervention.

    Science.gov (United States)

    Cavanaugh, Erica; Green, Sarah; Mallya, Giridhar; Tierney, Ann; Brensinger, Colleen; Glanz, Karen

    2014-08-01

    In response to the obesity epidemic, interventions to improve the food environment in corner stores have gained attention. This study evaluated the availability, quality, and price of foods in Philadelphia corner stores before and after a healthy corner store intervention with two levels of intervention intensity ("basic" and "conversion"). Observational measures of the food environment were completed in 2011 and again in 2012 in corner stores participating in the intervention, using the Nutrition Environment Measures Survey for Corner Stores (NEMS-CS). Main analyses included the 211 stores evaluated at both time-points. A time-by-treatment interaction analysis was used to evaluate the changes in NEMS-CS scores by intervention level over time. Availability of fresh fruit increased significantly in conversion stores over time. Specifically, there were significant increases in the availability of apples, oranges, grapes, and broccoli in conversion stores over time. Conversion stores showed a trend toward a significantly larger increase in the availability score compared to basic stores over time. Interventions aimed at increasing healthy food availability are associated with improvements in the availability of low-fat milk, fruits, and some vegetables, especially when infrastructure changes, such as refrigeration and shelving enhancements, are offered. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. The Working Environment and Changing Role of Corporate Librarians in Taiwan

    Directory of Open Access Journals (Sweden)

    Hsueh-hua Chen

    2003-06-01

    Full Text Available Influenced by the concept of “Knowledge Economics”, knowledge management (KM is getting a lot of attention in the field of business administration recently. Corporate centers are mostly affected by KM either in their working environment or in the role of their daily operation in the field of Library and Information Science. In the United States, the Special Library Association (SLA conducted numerous studies about the working environment and the changing role of corporate librarians in the past ten years. Due to the differences in politics, economics, and culture between Taiwan and the western countries, the organizational structure and corporate culture of the enterprise will not be exactly the same. Therefore, local studies on similar topics are needed. The purpose of this study is to explore the influence of the KM on the working environment and the changing roles of the corporate librarians in Taiwan based on the result of National Science Council Research Project executed by the authors.[Article content in Chinese

  8. Environment

    International Nuclear Information System (INIS)

    McIntyre, A.D.; Turnbull, R.G.H.

    1992-01-01

    The development of the hydrocarbon resources of the North Sea has resulted in both offshore and onshore environmental repercussions, involving the existing physical attributes of the sea and seabed, the coastline and adjoining land. The social and economic repercussions of the industry were equally widespread. The dramatic and speedy impact of the exploration and exploitation of the northern North Sea resources in the early 1970s, on the physical resources of Scotland was quickly realised together with the concern that any environmental and social damage to the physical and social fabric should be kept to a minimum. To this end, a wide range of research and other activities by central and local government, and other interested agencies was undertaken to extend existing knowledge on the marine and terrestrial environments that might be affected by the oil and gas industry. The outcome of these activities is summarized in this paper. The topics covered include a survey of the marine ecosystems of the North Sea, the fishing industry, the impact of oil pollution on seabirds and fish stocks, the ecology of the Scottish coastline and the impact of the petroleum industry on a selection of particular sites. (author)

  9. Risk attitudes in a changing environment: An evolutionary model of the fourfold pattern of risk preferences.

    Science.gov (United States)

    Mallpress, Dave E W; Fawcett, Tim W; Houston, Alasdair I; McNamara, John M

    2015-04-01

    A striking feature of human decision making is the fourfold pattern of risk attitudes, involving risk-averse behavior in situations of unlikely losses and likely gains, but risk-seeking behavior in response to likely losses and unlikely gains. Current theories to explain this pattern assume particular psychological processes to reproduce empirical observations, but do not address whether it is adaptive for the decision maker to respond to risk in this way. Here, drawing on insights from behavioral ecology, we build an evolutionary model of risk-sensitive behavior, to investigate whether particular types of environmental conditions could favor a fourfold pattern of risk attitudes. We consider an individual foraging in a changing environment, where energy is needed to prevent starvation and build up reserves for reproduction. The outcome, in terms of reproductive value (a rigorous measure of evolutionary success), of a one-off choice between a risky and a safe gain, or between a risky and a safe loss, determines the risk-sensitive behavior we should expect to see in this environment. Our results show that the fourfold pattern of risk attitudes may be adaptive in an environment in which conditions vary stochastically but are autocorrelated in time. In such an environment the current options provide information about the likely environmental conditions in the future, which affect the optimal pattern of risk sensitivity. Our model predicts that risk preferences should be both path dependent and affected by the decision maker's current state. (c) 2015 APA, all rights reserved).

  10. Bivalve aquaculture-environment interactions in the context of climate change.

    Science.gov (United States)

    Filgueira, Ramón; Guyondet, Thomas; Comeau, Luc A; Tremblay, Réjean

    2016-12-01

    Coastal embayments are at risk of impacts by climate change drivers such as ocean warming, sea level rise and alteration in precipitation regimes. The response of the ecosystem to these drivers is highly dependent on their magnitude of change, but also on physical characteristics such as bay morphology and river discharge, which play key roles in water residence time and hence estuarine functioning. These considerations are especially relevant for bivalve aquaculture sites, where the cultured biomass can alter ecosystem dynamics. The combination of climate change, physical and aquaculture drivers can result in synergistic/antagonistic and nonlinear processes. A spatially explicit model was constructed to explore effects of the physical environment (bay geomorphic type, freshwater inputs), climate change drivers (sea level, temperature, precipitation) and aquaculture (bivalve species, stock) on ecosystem functioning. A factorial design led to 336 scenarios (48 hydrodynamic × 7 management). Model outcomes suggest that the physical environment controls estuarine functioning given its influence on primary productivity (bottom-up control dominated by riverine nutrients) and horizontal advection with the open ocean (dominated by bay geomorphic type). The intensity of bivalve aquaculture ultimately determines the bivalve-phytoplankton trophic interaction, which can range from a bottom-up control triggered by ammonia excretion to a top-down control via feeding. Results also suggest that temperature is the strongest climate change driver due to its influence on the metabolism of poikilothermic organisms (e.g. zooplankton and bivalves), which ultimately causes a concomitant increase of top-down pressure on phytoplankton. Given the different thermal tolerance of cultured species, temperature is also critical to sort winners from losers, benefiting Crassostrea virginica over Mytilus edulis under the specific conditions tested in this numerical exercise. In general, it is

  11. Footprints of air pollution and changing environment on the sustainability of built infrastructure.

    Science.gov (United States)

    Kumar, Prashant; Imam, Boulent

    2013-02-01

    Over 150 research articles relating three multi-disciplinary topics (air pollution, climate change and civil engineering structures) are reviewed to examine the footprints of air pollution and changing environment on the sustainability of building and transport structures (referred as built infrastructure). The aim of this review is to synthesize the existing knowledge on this topic, highlight recent advances in our understanding and discuss research priorities. The article begins with the background information on sources and emission trends of global warming (CO(2), CH(4), N(2)O, CFCs, SF(6)) and corrosive (SO(2), O(3), NO(X)) gases and their role in deterioration of building materials (e.g. steel, stone, concrete, brick and wood) exposed in outdoor environments. Further section covers the impacts of climate- and pollution-derived chemical pathways, generally represented by dose-response functions (DRFs), and changing environmental conditions on built infrastructure. The article concludes with the discussions on the topic areas covered and research challenges. A comprehensive inventory of DRFs is compiled. The case study carried out for analysing the inter-comparability of various DRFs on four different materials (carbon steel, limestone, zinc and copper) produced comparable results. Results of another case study revealed that future projected changes in temperature and/or relatively humidity are expected to have a modest effect on the material deterioration rate whereas changes in precipitation were found to show a more dominant impact. Evidences suggest that both changing and extreme environmental conditions are expected to affect the integrity of built infrastructure both in terms of direct structural damage and indirect losses of transport network functionality. Unlike stone and metals, substantially limited information is available on the deterioration of brick, concrete and wooden structures. Further research is warranted to develop more robust and

  12. Biological correlates of extinction risk in bats.

    Science.gov (United States)

    Jones, Kate E; Purvis, Andy; Gittleman, John L

    2003-04-01

    We investigated patterns and processes of extinction and threat in bats using a multivariate phylogenetic comparative approach. Of nearly 1,000 species worldwide, 239 are considered threatened by the International Union for Conservation of Nature and Natural Resources (IUCN) and 12 are extinct. Small geographic ranges and low wing aspect ratios are independently found to predict extinction risk in bats, which explains 48% of the total variance in IUCN assessments of threat. The pattern and correlates of extinction risk in the two bat suborders are significantly different. A higher proportion (4%) of megachiropteran species have gone extinct in the last 500 years than microchiropteran bats (0.3%), and a higher proportion is currently at risk of extinction (Megachiroptera: 34%; Microchiroptera: 22%). While correlates of microchiropteran extinction risk are the same as in the order as a whole, megachiropteran extinction is correlated more with reproductive rate and less with wing morphology. Bat extinction risk is not randomly distributed phylogenetically: closely related species have more similar levels of threat than would be expected if extinction risk were random. Given the unbalanced nature of the evolutionary diversification of bats, it is probable that the amount of phylogenetic diversity lost if currently threatened taxa disappear may be greater than in other clades with numerically more threatened species.

  13. The ethics of reviving long extinct species.

    Science.gov (United States)

    Sandler, Ronald

    2014-04-01

    There now appears to be a plausible pathway for reviving species that have been extinct for several decades, centuries, or even millennia. I conducted an ethical analysis of de-extinction of long extinct species. I assessed several possible ethical considerations in favor of pursuing de-extinction: that it is a matter of justice; that it would reestablish lost value; that it would create new value; and that society needs it as a conservation last resort. I also assessed several possible ethical arguments against pursuing de-extinction: that it is unnatural; that it could cause animal suffering; that it could be ecologically problematic or detrimental to human health; and that it is hubristic. There are reasons in favor of reviving long extinct species, and it can be ethically acceptable to do so. However, the reasons in favor of pursuing de-extinction do not have to do with its usefulness in species conservation; rather, they concern the status of revived species as scientific and technological achievements, and it would be ethically problematic to promote de-extinction as a significant conservation strategy, because it does not prevent species extinctions, does not address the causes of extinction, and could be detrimental to some species conservation efforts. Moreover, humanity does not have a responsibility or obligation to pursue de-extinction of long extinct species, and reviving them does not address any urgent problem. Therefore, legitimate ecological, political, animal welfare, legal, or human health concerns associated with a de-extinction (and reintroduction) must be thoroughly addressed for it to be ethically acceptable. © 2013 Society for Conservation Biology.

  14. Size distribution of interstellar particles. III. Peculiar extinctions and normal infrared extinction

    International Nuclear Information System (INIS)

    Mathis, J.S.; Wallenhorst, S.G.

    1981-01-01

    The effect of changing the upper and lower size limits of a distribution of bare graphite and silicate particles with n(a)αa/sup -q/ is investigated. Mathis, Rumpl, and Nordsieck showed that the normal extinction is matched very well by having the small-size cutoff, a/sub -/, roughly-equal0.005 or 0.01 μm, and the large size a/sub +/, about 0.25 μm, and q = 3.5 for both substances. We consider the progressively peculiar extinctions exhibited by the well-observed stars, sigma Sco, rho Oph, and theta 1 Ori C, with values of R/sub v/[equivalentA/sub v//E(B--V)] of 3.4, 4.4, and 5.5 compared to the normal 3.1. Two (sigma Sco, rho Oph) are in a neutral dense cloud; theta 1 Ori C is in the Orion Nebula. We find that sigma Sco has a normal graphite distribution but has had its small silicate particles removed, so that a/sub -/(sil)roughly-equal0.04 μm if q = 3.5, or q(sil) = 2.6 if the size limits are fixed. However, the upper size limit on silicates remains normal. In rho Oph, the graphite is still normal, but both a/sub -/(sil) and a/sub +/(sil) are increased, to about 0.04 μm and 0.4 or 0.5 μm, respectively, if q = 3.5, or q(sil)roughly-equal1.3 if the size limits are fixed. In theta 1 Ori, the small limit on graphite has increased to about 0.04 μm, or q(gra)roughly-equal3, while the silicates are about like those in rho Oph. The calculated lambda2175 bump is broader than the observed, but normal foreground extinction probably contributes appreciably to the observed bump. The absolute amount of extinction per H atom for rho Oph is not explained. The column density of H is so large that systematic effects might be present. Very large graphite particles (a>3 μm) are required to ''hide'' the graphite without overly affecting the visual extinction, but a normal (small) graphite size distribution is required by the lambda2175 bump. We feel that it is unlikely that such a bimodal distribution exists

  15. Climate Change Impacts on the Built Environment in the United States and Implications for Sustainability

    Science.gov (United States)

    Quattrochi, Dale A.

    2012-01-01

    As an integral part of the National Climate Assessment (NCA), technical assessment reports for 13 regions in the U.S. that describe the scientific rationale to support climate change impacts within the purview of these regions, and provide adaptation or mitigation measures in response to these impacts. These technical assessments focus on climate change impacts on sectors that are important environmental, biophysical, and social and economic aspects of sustainability within the U.S.: Climate change science, Ecosystems and biodiversity, Water resources, Human health, Energy supply and use, Water/energy/land use, Transportation, Urban/infrastructure/vulnerability, Agriculture, Impacts of climate change on tribal/indigenous and native lands and resources, Forestry, Land use/land cover change, Rural communities development, and Impacts on biogeochemical cycles, with implications for ecosystems and biodiversity. There is a critical and timely need for the development of mitigation and adaptation strategies in response to climate change by the policy and decision making communities, to insure resiliency and sustainability of the built environment in the future.

  16. Change Of Learning Environment Using Game Production ­Theory, Methods And Practice

    DEFF Research Database (Denmark)

    Reng, Lars; Kofoed, Lise; Schoenau-Fog, Henrik

    2018-01-01

    will focus on cases in which development of games did change the learning environments into production units where students or employees were producing games as part of the learning process. The cases indicate that the motivation as well as the learning curve became very high. The pedagogical theories......Game Based Learning has proven to have many possibilities for supporting better learning outcomes, when using educational or commercial games in the classroom. However, there is also a great potential in using game development as a motivator in other kinds of learning scenarios. This study...... and methods are based on Problem Based Learning (PBL), but are developed further by combining PBL with a production-oriented/design based approach. We illustrate the potential of using game production as a learning environment with investigation of three game productions. We can conclude that using game...

  17. Evolution of regulatory networks towards adaptability and stability in a changing environment

    Science.gov (United States)

    Lee, Deok-Sun

    2014-11-01

    Diverse biological networks exhibit universal features distinguished from those of random networks, calling much attention to their origins and implications. Here we propose a minimal evolution model of Boolean regulatory networks, which evolve by selectively rewiring links towards enhancing adaptability to a changing environment and stability against dynamical perturbations. We find that sparse and heterogeneous connectivity patterns emerge, which show qualitative agreement with real transcriptional regulatory networks and metabolic networks. The characteristic scaling behavior of stability reflects the balance between robustness and flexibility. The scaling of fluctuation in the perturbation spread shows a dynamic crossover, which is analyzed by investigating separately the stochasticity of internal dynamics and the network structure differences depending on the evolution pathways. Our study delineates how the ambivalent pressure of evolution shapes biological networks, which can be helpful for studying general complex systems interacting with environments.

  18. Changes in the acoustic environment alter the foraging and sheltering behaviour of the cichlid Amititlania nigrofasciata.

    Science.gov (United States)

    McLaughlin, Kirsty Elizabeth; Kunc, Hansjoerg P

    2015-07-01

    Anthropogenic noise can affect behaviour across a wide range of species in both terrestrial and aquatic environments. However, behaviours might not be affected in isolation. Therefore, a more holistic approach investigating how environmental stressors, such as noise pollution, affect different behaviours in concert is necessary. Using tank-based noise exposure experiments, we tested how changes in the acoustic environment affect the behaviour of the cichlid Amatitlania nigrofasciata. We found that exposure to anthropogenic noise affected a couple of behaviours: an increase in sheltering was accompanied by a decrease in foraging. Our results highlight the multiple negative effects of an environmental stressor on an individual's behaviour. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Does opening a supermarket in a food desert change the food environment?

    Science.gov (United States)

    Ghosh-Dastidar, Madhumita; Hunter, Gerald; Collins, Rebecca L; Zenk, Shannon N; Cummins, Steven; Beckman, Robin; Nugroho, Alvin K; Sloan, Jennifer C; Wagner, La'Vette; Dubowitz, Tamara

    2017-07-01

    Improving access to healthy foods in low-income neighborhoods is a national priority. Our study evaluated the impact of opening a supermarket in a 'food desert' on healthy food access, availability and prices in the local food environment. We conducted 30 comprehensive in-store audits collecting information on healthy and unhealthy food availability, food prices and store environment, as well as 746 household surveys in two low-income neighborhoods before and after one of the two neighborhoods received a new supermarket. We found positive and negative changes in food availability, and an even greater influence on food prices in neighborhood stores. The supermarket opening in a 'food desert' caused little improvement in net availability of healthy foods, challenging the underpinnings of policies such as the Healthy Food Financing Initiative. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Changes of the agricultural enterprises economic environment originated by the agribusiness development

    Directory of Open Access Journals (Sweden)

    Věra Bečvářová

    2004-01-01

    Full Text Available Based upon analyses of the Common Agricultural Policy development and its economic tools reforming the process of changing is characterised there. It deals with the multifunctionality of agriculture as well as the influence of the CAP on environment of the production tasks of agriculture and food processing industry accomplishment. Paper generalises results of new trends of the agribusiness economic environment development and the opportunity of an effective utilization of production factors in agriculture. It deals with the sources and economic implications of partial enhancement of interest and redirection of support within framework and type of tools of agrarian policy. New quality of structure of relevant information needs and economic support for agricultural enterprises decision making process are pointed out.