Sample records for future potential distribution
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Climate Change and the Potential Distribution of an Invasive Shrub, Lantana camara L
Taylor, Subhashni; Kumar, Lalit; Reid, Nick; Kriticos, Darren J.
2012-01-01
The threat posed by invasive species, in particular weeds, to biodiversity may be exacerbated by climate change. Lantana camara L. (lantana) is a woody shrub that is highly invasive in many countries of the world. It has a profound economic and environmental impact worldwide, including Australia. Knowledge of the likely potential distribution of this invasive species under current and future climate will be useful in planning better strategies to manage the invasion. A process-oriented niche model of L. camara was developed using CLIMEX to estimate its potential distribution under current and future climate scenarios. The model was calibrated using data from several knowledge domains, including phenological observations and geographic distribution records. The potential distribution of lantana under historical climate exceeded the current distribution in some areas of the world, notably Africa and Asia. Under future scenarios, the climatically suitable areas for L. camara globally were projected to contract. However, some areas were identified in North Africa, Europe and Australia that may become climatically suitable under future climates. In South Africa and China, its potential distribution could expand further inland. These results can inform strategic planning by biosecurity agencies, identifying areas to target for eradication or containment. Distribution maps of risk of potential invasion can be useful tools in public awareness campaigns, especially in countries that have been identified as becoming climatically suitable for L. camara under the future climate scenarios. PMID:22536408
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Peterson, A. Townsend; Samy, Abdallah M.
2017-01-01
Background Ixodes ricinus is a species of hard tick that transmits several important diseases in Europe and North Africa, including Lyme borreliosis and tick-borne encephalitis. Climate change is affecting the geographic distributions and abundances of arthropod vectors, which in turn influence the geographic distribution and epidemiology of associated vector-borne diseases. To date, few studies have investigated effects of climate change on the spatial distribution of I. ricinus at continental extents. Here, we assessed the potential distribution of I. ricinus under current and future climate conditions to understand how climate change will influence the geographic distribution of this important tick vector in coming decades. Method We used ecological niche modeling to estimate the geographic distribution of I. ricinus with respect to current climate, and then assessed its future potential distribution under different climate change scenarios. This approach integrates occurrence records of I. ricinus with six relevant environmental variables over a continental extent that includes Europe, North Africa, and the Middle East. Future projections were based on climate data from 17 general circulation models (GCMs) under 2 representative concentration pathway emissions scenarios (RCPs), for the years 2050 and 2070. Result The present and future potential distributions of I. ricinus showed broad overlap across most of western and central Europe, and in more narrow zones in eastern and northern Europe, and North Africa. Potential expansions were observed in northern and eastern Europe. These results indicate that I. ricinus populations could emerge in areas in which they are currently lacking, posing increased risks to human health in those areas. However, the future of I. ricinus ticks in some important regions such the Mediterranean was unclear owing to high uncertainty in model predictions. PMID:29206879
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Alkishe, Abdelghafar A; Peterson, A Townsend; Samy, Abdallah M
2017-01-01
Ixodes ricinus is a species of hard tick that transmits several important diseases in Europe and North Africa, including Lyme borreliosis and tick-borne encephalitis. Climate change is affecting the geographic distributions and abundances of arthropod vectors, which in turn influence the geographic distribution and epidemiology of associated vector-borne diseases. To date, few studies have investigated effects of climate change on the spatial distribution of I. ricinus at continental extents. Here, we assessed the potential distribution of I. ricinus under current and future climate conditions to understand how climate change will influence the geographic distribution of this important tick vector in coming decades. We used ecological niche modeling to estimate the geographic distribution of I. ricinus with respect to current climate, and then assessed its future potential distribution under different climate change scenarios. This approach integrates occurrence records of I. ricinus with six relevant environmental variables over a continental extent that includes Europe, North Africa, and the Middle East. Future projections were based on climate data from 17 general circulation models (GCMs) under 2 representative concentration pathway emissions scenarios (RCPs), for the years 2050 and 2070. The present and future potential distributions of I. ricinus showed broad overlap across most of western and central Europe, and in more narrow zones in eastern and northern Europe, and North Africa. Potential expansions were observed in northern and eastern Europe. These results indicate that I. ricinus populations could emerge in areas in which they are currently lacking, posing increased risks to human health in those areas. However, the future of I. ricinus ticks in some important regions such the Mediterranean was unclear owing to high uncertainty in model predictions.
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Shrestha, Uttam Babu; Bawa, Kamaljit S.
2014-01-01
Climate change has already impacted ecosystems and species and substantial impacts of climate change in the future are expected. Species distribution modeling is widely used to map the current potential distribution of species as well as to model the impact of future climate change on distribution of species. Mapping current distribution is useful for conservation planning and understanding the change in distribution impacted by climate change is important for mitigation of future biodiversity losses. However, the current distribution of Chinese caterpillar fungus, a flagship species of the Himalaya with very high economic value, is unknown. Nor do we know the potential changes in suitable habitat of Chinese caterpillar fungus caused by future climate change. We used MaxEnt modeling to predict current distribution and changes in the future distributions of Chinese caterpillar fungus in three future climate change trajectories based on representative concentration pathways (RCPs: RCP 2.6, RCP 4.5, and RCP 6.0) in three different time periods (2030, 2050, and 2070) using species occurrence points, bioclimatic variables, and altitude. About 6.02% (8,989 km2) area of the Nepal Himalaya is suitable for Chinese caterpillar fungus habitat. Our model showed that across all future climate change trajectories over three different time periods, the area of predicted suitable habitat of Chinese caterpillar fungus would expand, with 0.11–4.87% expansion over current suitable habitat. Depending upon the representative concentration pathways, we observed both increase and decrease in average elevation of the suitable habitat range of the species. PMID:25180515
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Shrestha, Uttam Babu; Bawa, Kamaljit S
2014-01-01
Climate change has already impacted ecosystems and species and substantial impacts of climate change in the future are expected. Species distribution modeling is widely used to map the current potential distribution of species as well as to model the impact of future climate change on distribution of species. Mapping current distribution is useful for conservation planning and understanding the change in distribution impacted by climate change is important for mitigation of future biodiversity losses. However, the current distribution of Chinese caterpillar fungus, a flagship species of the Himalaya with very high economic value, is unknown. Nor do we know the potential changes in suitable habitat of Chinese caterpillar fungus caused by future climate change. We used MaxEnt modeling to predict current distribution and changes in the future distributions of Chinese caterpillar fungus in three future climate change trajectories based on representative concentration pathways (RCPs: RCP 2.6, RCP 4.5, and RCP 6.0) in three different time periods (2030, 2050, and 2070) using species occurrence points, bioclimatic variables, and altitude. About 6.02% (8,989 km2) area of the Nepal Himalaya is suitable for Chinese caterpillar fungus habitat. Our model showed that across all future climate change trajectories over three different time periods, the area of predicted suitable habitat of Chinese caterpillar fungus would expand, with 0.11-4.87% expansion over current suitable habitat. Depending upon the representative concentration pathways, we observed both increase and decrease in average elevation of the suitable habitat range of the species.
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NASA Astrophysics Data System (ADS)
Gohardani, Amir S.; Doulgeris, Georgios; Singh, Riti
2011-07-01
This paper highlights the role of distributed propulsion technology for future commercial aircraft. After an initial historical perspective on the conceptual aspects of distributed propulsion technology and a glimpse at numerous aircraft that have taken distributed propulsion technology to flight, the focal point of the review is shifted towards a potential role this technology may entail for future commercial aircraft. Technological limitations and challenges of this specific technology are also considered in combination with an all electric aircraft concept, as means of predicting the challenges associated with the design process of a next generation commercial aircraft.
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The pace of past climate change vs. potential bird distributions and land use in the United States
Bateman, Brooke L.; Pidgeon, Anna M.; Radeloff, Volker C.; VanDerWal, Jeremy; Thogmartin, Wayne E.; Vavrus, Stephen J.; Heglund, Patricia J.
2016-01-01
Climate change may drastically alter patterns of species distributions and richness, but predicting future species patterns in occurrence is challenging. Significant shifts in distributions have already been observed, and understanding these recent changes can improve our understanding of potential future changes. We assessed how past climate change affected potential breeding distributions for landbird species in the conterminous United States. We quantified the bioclimatic velocity of potential breeding distributions, that is, the pace and direction of change for each species’ suitable climate space over the past 60 years. We found that potential breeding distributions for landbirds have shifted substantially with an average velocity of 1.27 km yr−1, about double the pace of prior distribution shift estimates across terrestrial systems globally (0.61 km yr−1). The direction of shifts was not uniform. The majority of species’ distributions shifted west, northwest, and north. Multidirectional shifts suggest that changes in climate conditions beyond mean temperature were influencing distributional changes. Indeed, precipitation variables that were proxies for extreme conditions were important variables across all models. There were winners and losers in terms of the area of distributions; many species experienced contractions along west and east distribution edges, and expansions along northern distribution edges. Changes were also reflected in the potential species richness, with some regions potentially gaining species (Midwest, East) and other areas potentially losing species (Southwest). However, the degree to which changes in potential breeding distributions are manifested in actual species richness depends on landcover. Areas that have become increasingly suitable for breeding birds due to changing climate are often those attractive to humans for agriculture and development. This suggests that many areas might have supported more breeding bird species had the landscape not been altered. Our study illustrates that climate change is not only a future threat, but something birds are already experiencing.
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The pace of past climate change vs. potential bird distributions and land use in the United States.
Bateman, Brooke L; Pidgeon, Anna M; Radeloff, Volker C; VanDerWal, Jeremy; Thogmartin, Wayne E; Vavrus, Stephen J; Heglund, Patricia J
2016-03-01
Climate change may drastically alter patterns of species distributions and richness, but predicting future species patterns in occurrence is challenging. Significant shifts in distributions have already been observed, and understanding these recent changes can improve our understanding of potential future changes. We assessed how past climate change affected potential breeding distributions for landbird species in the conterminous United States. We quantified the bioclimatic velocity of potential breeding distributions, that is, the pace and direction of change for each species' suitable climate space over the past 60 years. We found that potential breeding distributions for landbirds have shifted substantially with an average velocity of 1.27 km yr(-1) , about double the pace of prior distribution shift estimates across terrestrial systems globally (0.61 km yr(-1) ). The direction of shifts was not uniform. The majority of species' distributions shifted west, northwest, and north. Multidirectional shifts suggest that changes in climate conditions beyond mean temperature were influencing distributional changes. Indeed, precipitation variables that were proxies for extreme conditions were important variables across all models. There were winners and losers in terms of the area of distributions; many species experienced contractions along west and east distribution edges, and expansions along northern distribution edges. Changes were also reflected in the potential species richness, with some regions potentially gaining species (Midwest, East) and other areas potentially losing species (Southwest). However, the degree to which changes in potential breeding distributions are manifested in actual species richness depends on landcover. Areas that have become increasingly suitable for breeding birds due to changing climate are often those attractive to humans for agriculture and development. This suggests that many areas might have supported more breeding bird species had the landscape not been altered. Our study illustrates that climate change is not only a future threat, but something birds are already experiencing. © 2015 John Wiley & Sons Ltd.
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Uncertainties in the projection of species distributions related to general circulation models
Goberville, Eric; Beaugrand, Grégory; Hautekèete, Nina-Coralie; Piquot, Yves; Luczak, Christophe
2015-01-01
Ecological Niche Models (ENMs) are increasingly used by ecologists to project species potential future distribution. However, the application of such models may be challenging, and some caveats have already been identified. While studies have generally shown that projections may be sensitive to the ENM applied or the emission scenario, to name just a few, the sensitivity of ENM-based scenarios to General Circulation Models (GCMs) has been often underappreciated. Here, using a multi-GCM and multi-emission scenario approach, we evaluated the variability in projected distributions under future climate conditions. We modeled the ecological realized niche (sensu Hutchinson) and predicted the baseline distribution of species with contrasting spatial patterns and representative of two major functional groups of European trees: the dwarf birch and the sweet chestnut. Their future distributions were then projected onto future climatic conditions derived from seven GCMs and four emissions scenarios using the new Representative Concentration Pathways (RCPs) developed for the Intergovernmental Panel on Climate Change (IPCC) AR5 report. Uncertainties arising from GCMs and those resulting from emissions scenarios were quantified and compared. Our study reveals that scenarios of future species distribution exhibit broad differences, depending not only on emissions scenarios but also on GCMs. We found that the between-GCM variability was greater than the between-RCP variability for the next decades and both types of variability reached a similar level at the end of this century. Our result highlights that a combined multi-GCM and multi-RCP approach is needed to better consider potential trajectories and uncertainties in future species distributions. In all cases, between-GCM variability increases with the level of warming, and if nothing is done to alleviate global warming, future species spatial distribution may become more and more difficult to anticipate. When future species spatial distributions are examined, we propose to use a large number of GCMs and RCPs to better anticipate potential trajectories and quantify uncertainties. PMID:25798227
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Mendoza-González, Gabriela; Martínez, M Luisa; Rojas-Soto, Octavio R; Vázquez, Gabriela; Gallego-Fernández, Juan B
2013-08-01
Climate change (CC) and sea level rise (SLR) are phenomena that could have severe impacts on the distribution of coastal dune vegetation. To explore this we modeled the climatic niches of six coastal dunes plant species that grow along the shoreline of the Gulf of Mexico and the Yucatan Peninsula, and projected climatic niches to future potential distributions based on two CC scenarios and SLR projections. Our analyses suggest that distribution of coastal plants will be severely limited, and more so in the case of local endemics (Chamaecrista chamaecristoides, Palafoxia lindenii, Cakile edentula). The possibilities of inland migration to the potential 'new shoreline' will be limited by human infrastructure and ecosystem alteration that will lead to a 'coastal squeeze' of the coastal habitats. Finally, we identified areas as future potential refuges for the six species in central Gulf of Mexico, and northern Yucatán Peninsula especially under CC and SLR scenarios. © 2013 John Wiley & Sons Ltd.
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Re-Shuffling of Species with Climate Disruption: A No-Analog Future for California Birds?
Stralberg, Diana; Jongsomjit, Dennis; Howell, Christine A.; Snyder, Mark A.; Alexander, John D.; Wiens, John A.; Root, Terry L.
2009-01-01
By facilitating independent shifts in species' distributions, climate disruption may result in the rapid development of novel species assemblages that challenge the capacity of species to co-exist and adapt. We used a multivariate approach borrowed from paleoecology to quantify the potential change in California terrestrial breeding bird communities based on current and future species-distribution models for 60 focal species. Projections of future no-analog communities based on two climate models and two species-distribution-model algorithms indicate that by 2070 over half of California could be occupied by novel assemblages of bird species, implying the potential for dramatic community reshuffling and altered patterns of species interactions. The expected percentage of no-analog bird communities was dependent on the community scale examined, but consistent geographic patterns indicated several locations that are particularly likely to host novel bird communities in the future. These no-analog areas did not always coincide with areas of greatest projected species turnover. Efforts to conserve and manage biodiversity could be substantially improved by considering not just future changes in the distribution of individual species, but including the potential for unprecedented changes in community composition and unanticipated consequences of novel species assemblages. PMID:19724641
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Inman, Richard D.; Esque, Todd C.; Nussear, Kenneth E.; Leitner, Philip; Matocq, Marjorie D.; Weisberg, Peter J.; Dilts, Thomas E.
2016-01-01
Predicting changes in species distributions under a changing climate is becoming widespread with the use of species distribution models (SDMs). The resulting predictions of future potential habitat can be cast in light of planned land use changes, such as urban expansion and energy development to identify areas with potential conflict. However, SDMs rarely incorporate an understanding of dispersal capacity, and therefore assume unlimited dispersal in potential range shifts under uncertain climate futures. We use SDMs to predict future distributions of the Mojave ground squirrel, Xerospermophilus mohavensis Merriam, and incorporate partial dispersal models informed by field data on juvenile dispersal to assess projected impact of climate change and energy development on future distributions of X. mohavensis. Our models predict loss of extant habitat, but also concurrent gains of new habitat under two scenarios of future climate change. Under the B1 emissions scenario- a storyline describing a convergent world with emphasis on curbing greenhouse gas emissions- our models predicted losses of up to 64% of extant habitat by 2080, while under the increased greenhouse gas emissions of the A2 scenario, we suggest losses of 56%. New potential habitat may become available to X. mohavensis, thereby offsetting as much as 6330 km2 (50%) of the current habitat lost. Habitat lost due to planned energy development was marginal compared to habitat lost from changing climates, but disproportionately affected current habitat. Future areas of overlap in potential habitat between the two climate change scenarios are identified and discussed in context of proposed energy development.
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NASA Astrophysics Data System (ADS)
Cuyckens, G. A. E.; Christie, D. A.; Domic, A. I.; Malizia, L. R.; Renison, D.
2016-02-01
Climate change is becoming an increasing threat to biodiversity. Consequently, methods for delineation, establishment and management of protected areas must consider the species' future distribution in response to future climate conditions. Biodiversity in high altitude semiarid regions may be particularly threatened by future climate change. In this study we assess the main environmental variables that best explain present day presence of the world's highest elevation woodlands in the South American Altiplano, and model how climate change may affect the future distribution of this unique ecosystem under different climate change scenarios. These woodlands are dominated by Polylepis tarapacana (Rosaceae), a species that forms unique biological communities with important conservation value. Our results indicate that five environmental variables are responsible for 91% and 90.3% of the present and future P. tarapacana distribution models respectively, and suggest that at the end of the 21st century, there will be a significant reduction (56%) in the potential habitat for this species due to more arid conditions. Since it is predicted that P. tarapacana's potential distribution will be severely reduced in the future, we propose a new network of national protected areas across this species distribution range in order to insure the future conservation of this unique ecosystem. Based on an extensive literature review we identify research topics and recommendations for on-ground conservation and management of P. tarapacana woodlands.
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Spatially distributed potential evapotranspiration modeling and climate projections.
Gharbia, Salem S; Smullen, Trevor; Gill, Laurence; Johnston, Paul; Pilla, Francesco
2018-08-15
Evapotranspiration integrates energy and mass transfer between the Earth's surface and atmosphere and is the most active mechanism linking the atmosphere, hydrosphsophere, lithosphere and biosphere. This study focuses on the fine resolution modeling and projection of spatially distributed potential evapotranspiration on the large catchment scale as response to climate change. Six potential evapotranspiration designed algorithms, systematically selected based on a structured criteria and data availability, have been applied and then validated to long-term mean monthly data for the Shannon River catchment with a 50m 2 cell size. The best validated algorithm was therefore applied to evaluate the possible effect of future climate change on potential evapotranspiration rates. Spatially distributed potential evapotranspiration projections have been modeled based on climate change projections from multi-GCM ensembles for three future time intervals (2020, 2050 and 2080) using a range of different Representative Concentration Pathways producing four scenarios for each time interval. Finally, seasonal results have been compared to baseline results to evaluate the impact of climate change on the potential evapotranspiration and therefor on the catchment dynamical water balance. The results present evidence that the modeled climate change scenarios would have a significant impact on the future potential evapotranspiration rates. All the simulated scenarios predicted an increase in potential evapotranspiration for each modeled future time interval, which would significantly affect the dynamical catchment water balance. This study addresses the gap in the literature of using GIS-based algorithms to model fine-scale spatially distributed potential evapotranspiration on the large catchment systems based on climatological observations and simulations in different climatological zones. Providing fine-scale potential evapotranspiration data is very crucial to assess the dynamical catchment water balance to setup management scenarios for the water abstractions. This study illustrates a transferable systematic method to design GIS-based algorithms to simulate spatially distributed potential evapotranspiration on the large catchment systems. Copyright © 2018 Elsevier B.V. All rights reserved.
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Liu, Xuan; Guo, Zhongwei; Ke, Zunwei; Wang, Supen; Li, Yiming
2011-01-01
Background Anthropogenically-induced climate change can alter the current climatic habitat of non-native species and can have complex effects on potentially invasive species. Predictions of the potential distributions of invasive species under climate change will provide critical information for future conservation and management strategies. Aquatic ecosystems are particularly vulnerable to invasive species and climate change, but the effect of climate change on invasive species distributions has been rather neglected, especially for notorious global invaders. Methodology/Principal Findings We used ecological niche models (ENMs) to assess the risks and opportunities that climate change presents for the red swamp crayfish (Procambarus clarkii), which is a worldwide aquatic invasive species. Linking the factors of climate, topography, habitat and human influence, we developed predictive models incorporating both native and non-native distribution data of the crayfish to identify present areas of potential distribution and project the effects of future climate change based on a consensus-forecast approach combining the CCCMA and HADCM3 climate models under two emission scenarios (A2a and B2a) by 2050. The minimum temperature from the coldest month, the human footprint and precipitation of the driest quarter contributed most to the species distribution models. Under both the A2a and B2a scenarios, P. clarkii shifted to higher latitudes in continents of both the northern and southern hemispheres. However, the effect of climate change varied considerately among continents with an expanding potential in Europe and contracting changes in others. Conclusions/Significance Our findings are the first to predict the impact of climate change on the future distribution of a globally invasive aquatic species. We confirmed the complexities of the likely effects of climate change on the potential distribution of globally invasive species, and it is extremely important to develop wide-ranging and effective control measures according to predicted geographical shifts and changes. PMID:21479188
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Mark W. Schwartz; Louis R. Iverson; Anantha M. Prasad
2001-01-01
We investigated the effect of habitat loss on the ability of trees to shift in distribution across a landscape dominated by agriculture. The potential distribution shifts of four tree species (Diospyros virginiana, Oxydendron arboreum, Pinus virginiana, Quercus falcata var. falcata) whose northern distribution limits fall in the...
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K.M. Burnett; G.H. Reeves; D.J. Miller; S. Clarke; K. Vance-Borland; K. Christiansen
2007-01-01
The geographic distribution of stream reaches with potential to support high-quality habitat for salmonids has bearing on the actual status of habitats and populations over broad spatial extents. As part of the Coastal Landscape Analysis and Modeling Study, we examined how salmon-habitat potential was distributed relative to current and future (+100 years) landscape...
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Graham, Jim; Jarnevich, Catherine; Young, Nick; Newman, Greg; Stohlgren, Thomas
2011-01-01
Habitat suitability models have been used to predict the present and future potential distribution of a variety of species. Eurasian tree sparrows Passer montanus, native to Eurasia, have established populations in other parts of the world. In North America, their current distribution is limited to a relatively small region around its original introduction to St. Louis, Missouri. We combined data from the Global Biodiversity Information Facility with current and future climate data to create habitat suitability models using Maxent for this species. Under projected climate change scenarios, our models show that the distribution and range of the Eurasian tree sparrow could increase as far as the Pacific Northwest and Newfoundland. This is potentially important information for prioritizing the management and control of this non-native species.
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Near term climate projections for invasive species distributions
Jarnevich, C.S.; Stohlgren, T.J.
2009-01-01
Climate change and invasive species pose important conservation issues separately, and should be examined together. We used existing long term climate datasets for the US to project potential climate change into the future at a finer spatial and temporal resolution than the climate change scenarios generally available. These fine scale projections, along with new species distribution modeling techniques to forecast the potential extent of invasive species, can provide useful information to aide conservation and invasive species management efforts. We created habitat suitability maps for Pueraria montana (kudzu) under current climatic conditions and potential average conditions up to 30 years in the future. We examined how the potential distribution of this species will be affected by changing climate, and the management implications associated with these changes. Our models indicated that P. montana may increase its distribution particularly in the Northeast with climate change and may decrease in other areas. ?? 2008 Springer Science+Business Media B.V.
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Atlas of current and potential future distributions of common trees of the eastern United States
Louis R. Iverson; Anantha M. Prasad; Betsy J. Hale; Elaine Kennedy Sutherland
1999-01-01
This atlas documents the current and possible future distribution of 80 common tree species in the Eastern United States and gives detailed information on environmental characteristics defining these distributions. Also included are outlines of life history characteristics and summary statistics for these species. Much of the data are derived from Forest Inventory and...
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Bai, Yunjun; Wei, Xueping
2018-01-01
Background The ongoing change in climate is predicted to exert unprecedented effects on Earth’s biodiversity at all levels of organization. Biological conservation is important to prevent biodiversity loss, especially for species facing a high risk of extinction. Understanding the past responses of species to climate change is helpful for revealing response mechanisms, which will contribute to the development of effective conservation strategies in the future. Methods In this study, we modelled the distributional dynamics of a ‘Vulnerable’ species, Pseudolarix amabilis, in response to late Quaternary glacial-interglacial cycles and future 2080 climate change using an ecological niche model (MaxEnt). We also performed migration vector analysis to reveal the potential migration of the population over time. Results Historical modelling indicates that the range dynamics of P. amabilis is highly sensitive to climate change and that its long-distance dispersal ability and potential for evolutionary adaption are limited. Compared to the current climatically suitable areas for this species, future modelling showed significant migration northward towards future potential climatically suitable areas. Discussion In combination with the predicted future distribution, the mechanism revealed by the historical response suggests that this species will not be able to fully occupy the future expanded areas of suitable climate or adapt to the unsuitable climate across the future contraction regions. As a result, we suggest assisted migration as an effective supplementary means of conserving this vulnerable species in the face of the unprecedentedly rapid climate change of the 21st century. As a study case, this work highlights the significance of introducing historical perspectives while researching species conservation, especially for currently vulnerable or endangered taxa that once had a wider distribution in geological time. PMID:29362700
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Bai, Yunjun; Wei, Xueping; Li, Xiaoqiang
2018-01-01
The ongoing change in climate is predicted to exert unprecedented effects on Earth's biodiversity at all levels of organization. Biological conservation is important to prevent biodiversity loss, especially for species facing a high risk of extinction. Understanding the past responses of species to climate change is helpful for revealing response mechanisms, which will contribute to the development of effective conservation strategies in the future. In this study, we modelled the distributional dynamics of a 'Vulnerable' species, Pseudolarix amabilis , in response to late Quaternary glacial-interglacial cycles and future 2080 climate change using an ecological niche model (MaxEnt). We also performed migration vector analysis to reveal the potential migration of the population over time. Historical modelling indicates that the range dynamics of P. amabilis is highly sensitive to climate change and that its long-distance dispersal ability and potential for evolutionary adaption are limited. Compared to the current climatically suitable areas for this species, future modelling showed significant migration northward towards future potential climatically suitable areas. In combination with the predicted future distribution, the mechanism revealed by the historical response suggests that this species will not be able to fully occupy the future expanded areas of suitable climate or adapt to the unsuitable climate across the future contraction regions. As a result, we suggest assisted migration as an effective supplementary means of conserving this vulnerable species in the face of the unprecedentedly rapid climate change of the 21st century. As a study case, this work highlights the significance of introducing historical perspectives while researching species conservation, especially for currently vulnerable or endangered taxa that once had a wider distribution in geological time.
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Steen, Valerie; Powell, Abby N.
2012-01-01
Wetland-dependent birds are considered to be at particularly high risk for negative climate change effects. Current and future distributions of American Bittern (Botaurus lentiginosus), American Coot (Fulica americana), Black Tern (Chlidonias niger), Pied-billed Grebe (Podilymbus podiceps) and Sora (Porzana carolina), five waterbird species common in the Prairie Pothole Region (PPR), were predicted using species distribution models (SDMs) in combination with climate data that projected a drier future for the PPR. Regional-scale SDMs were created for the U.S. PPR using breeding bird survey occurrence records for 1971-2000 and wetland and climate parameters. For each waterbird species, current distribution and four potential future distributions were predicted: all combinations of two Global Circulation Models and two emissions scenarios. Averaged for all five species, the ensemble range reduction was 64%. However, projected range losses for individual species varied widely with Sora and Black Tern projected to lose close to 100% and American Bittern 29% of their current range. Future distributions were also projected to a hypothetical landscape where wetlands were numerous and constant to highlight areas suitable as conservation reserves under a drier future climate. The ensemble model indicated that northeastern North Dakota and northern Minnesota would be the best areas for conservation reserves within the U.S. PPR under the modeled conditions.
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Mark W. Schwartz; Louis R. Iverson; Anantha M. Prasad; Anantha M. Prasad
2000-01-01
We investigated the effect of habitat loss on the ability of trees to shift in distribution across a landscape dominated by agriculture. The potential distribution shifts of four tree species (Diospyros virginiana, Oxydendron arboreum, Pinus virginiana, Quercus falcata var. falcata) whose northern distribution limits fall in the southern third of Ohio were used to...
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Heather Griscom; Helmut Kraenzle; Zachary. Bortolot
2010-01-01
The objective of our project is to create a habitat suitability model to predict potential and future red spruce forest distributions. This model will be used to better understand the influence of climate change on red spruce distribution and to help guide forest restoration efforts.
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NASA Astrophysics Data System (ADS)
Gohardani, Amir S.
2013-02-01
Distributed propulsion is one of the revolutionary candidates for future aircraft propulsion. In this journal article, the potential role of distributed propulsion technology in future aviation is investigated. Following a historical journey that revisits distributed propulsion technology in unmanned air vehicles and military aircraft, features of this specific technology are highlighted in synergy with an electric aircraft concept and a first-of-a-kind comparison to commercial aircraft employing distributed propulsion arrangements. In light of propulsion-airframe integration and complementary technologies such as boundary layer ingestion, thrust vectoring and circulation control, transpired opportunities and challenges are addressed in addition to a number of identified research directions proposed for future aircraft. The motivation behind enhanced means of communication between engineers, researchers and scientists has stimulated a novel proposed definition for the distributed propulsion technology in aviation and is presented herein.
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Malaria vectors in South America: current and future scenarios.
Laporta, Gabriel Zorello; Linton, Yvonne-Marie; Wilkerson, Richard C; Bergo, Eduardo Sterlino; Nagaki, Sandra Sayuri; Sant'Ana, Denise Cristina; Sallum, Maria Anice Mureb
2015-08-19
Malaria remains a significant public health issue in South America. Future climate change may influence the distribution of the disease, which is dependent on the distribution of those Anopheles mosquitoes competent to transmit Plasmodium falciparum. Herein, predictive niche models of the habitat suitability for P. falciparum, the current primary vector Anopheles darlingi and nine other known and/or potential vector species of the Neotropical Albitarsis Complex, were used to document the current situation and project future scenarios under climate changes in South America in 2070. To build each ecological niche model, we employed topography, climate and biome, and the currently defined distribution of P. falciparum, An. darlingi and nine species comprising the Albitarsis Complex in South America. Current and future (i.e., 2070) distributions were forecast by projecting the fitted ecological niche model onto the current environmental situation and two scenarios of simulated climate change. Statistical analyses were performed between the parasite and each vector in both the present and future scenarios to address potential vector roles in the dynamics of malaria transmission. Current distributions of malaria vector species were associated with that of P. falciparum, confirming their role in transmission, especially An. darlingi, An. marajoara and An. deaneorum. Projected climate changes included higher temperatures, lower water availability and biome modifications. Regardless of future scenarios considered, the geographic distribution of P. falciparum was exacerbated in 2070 South America, with the distribution of the pathogen covering 35-46% of the continent. As the current primary vector An. darlingi showed low tolerance for drier environments, the projected climate change would significantly reduce suitable habitat, impacting both its distribution and abundance. Conversely, climate generalist members of the Albitarsis Complex showed significant spatial and temporal expansion potential in 2070, and we conclude these species will become more important in the dynamics of malaria transmission in South America. Our data suggest that climate and landscape effects will elevate the importance of members of the Albitarsis Complex in malaria transmission in South America in 2070, highlighting the need for further studies addressing the bionomics, ecology and behaviours of the species comprising the Albitarsis Complex.
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Assessment of the Economic Potential of Distributed Wind in Colorado, Minnesota, and New York
DOE Office of Scientific and Technical Information (OSTI.GOV)
McCabe, Kevin; Sigrin, Benjamin O.; Lantz, Eric J.
This work seeks to identify current and future spatial distributions of economic potential for behind-the-meter distributed wind, serving primarily rural or suburban homes, farms, and manufacturing facilities in Colorado, Minnesota, and New York. These states were identified by technical experts based on their current favorability for distributed wind deployment. We use NREL's Distributed Wind Market Demand Model (dWind) (Lantz et al. 2017; Sigrin et al. 2016) to identify and rank counties in each of the states by their overall and per capita potential. From this baseline assessment, we also explore how and where improvements in cost, performance, and other marketmore » sensitivities affect distributed wind potential.« less
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Design Flexibility for Uncertain Distributed Generation from Photovoltaics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Palmintier, Bryan; Krishnamurthy, Dheepak; Wu, Hongyu
2016-12-12
Uncertainty in the future adoption patterns for distributed energy resources (DERs) introduces a challenge for electric distribution system planning. This paper explores the potential for flexibility in design - also known as real options - to identify design solutions that may never emerge when future DER patterns are treated as deterministic. A test case for storage system design with uncertain distributed generation for solar photovoltaics (DGPV) demonstrates this approach and is used to study sensitivities to a range of techno-economic assumptions.
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2014-01-01
Background The Triatoma brasiliensis complex is a monophyletic group, comprising three species, one of which includes two subspecific taxa, distributed across 12 Brazilian states, in the caatinga and cerrado biomes. Members of the complex are diverse in terms of epidemiological importance, morphology, biology, ecology, and genetics. Triatoma b. brasiliensis is the most disease-relevant member of the complex in terms of epidemiology, extensive distribution, broad feeding preferences, broad ecological distribution, and high rates of infection with Trypanosoma cruzi; consequently, it is considered the principal vector of Chagas disease in northeastern Brazil. Methods We used ecological niche models to estimate potential distributions of all members of the complex, and evaluated the potential for suitable adjacent areas to be colonized; we also present first evaluations of potential for climate change-mediated distributional shifts. Models were developed using the GARP and Maxent algorithms. Results Models for three members of the complex (T. b. brasiliensis, N = 332; T. b. macromelasoma, N = 35; and T. juazeirensis, N = 78) had significant distributional predictivity; however, models for T. sherlocki and T. melanica, both with very small sample sizes (N = 7), did not yield predictions that performed better than random. Model projections onto future-climate scenarios indicated little broad-scale potential for change in the potential distribution of the complex through 2050. Conclusions This study suggests that T. b. brasiliensis is the member of the complex with the greatest distributional potential to colonize new areas: overall; however, the distribution of the complex appears relatively stable. These analyses offer key information to guide proactive monitoring and remediation activities to reduce risk of Chagas disease transmission. PMID:24886587
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Peterson, A Townsend; Campbell, Lindsay P; Moo-Llanes, David A; Travi, Bruno; González, Camila; Ferro, María Cristina; Ferreira, Gabriel Eduardo Melim; Brandão-Filho, Sinval P; Cupolillo, Elisa; Ramsey, Janine; Leffer, Andreia Mauruto Chernaki; Pech-May, Angélica; Shaw, Jeffrey J
2017-09-01
This study explores the present day distribution of Lutzomyia longipalpis in relation to climate, and transfers the knowledge gained to likely future climatic conditions to predict changes in the species' potential distribution. We used ecological niche models calibrated based on occurrences of the species complex from across its known geographic range. Anticipated distributional changes varied by region, from stability to expansion or decline. Overall, models indicated no significant north-south expansion beyond present boundaries. However, some areas suitable both at present and in the future (e.g., Pacific coast of Ecuador and Peru) may offer opportunities for distributional expansion. Our models anticipated potential range expansion in southern Brazil and Argentina, but were variably successful in anticipating specific cases. The most significant climate-related change anticipated in the species' range was with regard to range continuity in the Amazon Basin, which is likely to increase in coming decades. Rather than making detailed forecasts of actual locations where Lu. longipalpis will appear in coming years, our models make interesting and potentially important predictions of broader-scale distributional tendencies that can inform heath policy and mitigation efforts. Copyright © 2017 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.
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Jarnevich, Catherine S.; Young, Nicholas E; Sheffels, Trevor R.; Carter, Jacoby; Systma, Mark D.; Talbert, Colin
2017-01-01
Invasive species provide a unique opportunity to evaluate factors controlling biogeographic distributions; we can consider introduction success as an experiment testing suitability of environmental conditions. Predicting potential distributions of spreading species is not easy, and forecasting potential distributions with changing climate is even more difficult. Using the globally invasive coypu (Myocastor coypus [Molina, 1782]), we evaluate and compare the utility of a simplistic ecophysiological based model and a correlative model to predict current and future distribution. The ecophysiological model was based on winter temperature relationships with nutria survival. We developed correlative statistical models using the Software for Assisted Habitat Modeling and biologically relevant climate data with a global extent. We applied the ecophysiological based model to several global circulation model (GCM) predictions for mid-century. We used global coypu introduction data to evaluate these models and to explore a hypothesized physiological limitation, finding general agreement with known coypu distribution locally and globally and support for an upper thermal tolerance threshold. Global circulation model based model results showed variability in coypu predicted distribution among GCMs, but had general agreement of increasing suitable area in the USA. Our methods highlighted the dynamic nature of the edges of the coypu distribution due to climate non-equilibrium, and uncertainty associated with forecasting future distributions. Areas deemed suitable habitat, especially those on the edge of the current known range, could be used for early detection of the spread of coypu populations for management purposes. Combining approaches can be beneficial to predicting potential distributions of invasive species now and in the future and in exploring hypotheses of factors controlling distributions.
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Ge, Xuezhen; He, Shanyong; Wang, Tao; Yan, Wei; Zong, Shixiang
2015-01-01
As the primary pest of palm trees, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) has caused serious harm to palms since it first invaded China. The present study used CLIMEX 1.1 to predict the potential distribution of R. ferrugineus in China according to both current climate data (1981-2010) and future climate warming estimates based on simulated climate data for the 2020s (2011-2040) provided by the Tyndall Center for Climate Change Research (TYN SC 2.0). Additionally, the Ecoclimatic Index (EI) values calculated for different climatic conditions (current and future, as simulated by the B2 scenario) were compared. Areas with a suitable climate for R. ferrugineus distribution were located primarily in central China according to the current climate data, with the northern boundary of the distribution reaching to 40.1°N and including Tibet, north Sichuan, central Shaanxi, south Shanxi, and east Hebei. There was little difference in the potential distribution predicted by the four emission scenarios according to future climate warming estimates. The primary prediction under future climate warming models was that, compared with the current climate model, the number of highly favorable habitats would increase significantly and expand into northern China, whereas the number of both favorable and marginally favorable habitats would decrease. Contrast analysis of EI values suggested that climate change and the density of site distribution were the main effectors of the changes in EI values. These results will help to improve control measures, prevent the spread of this pest, and revise the targeted quarantine areas.
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Ge, Xuezhen; He, Shanyong; Wang, Tao; Yan, Wei; Zong, Shixiang
2015-01-01
As the primary pest of palm trees, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) has caused serious harm to palms since it first invaded China. The present study used CLIMEX 1.1 to predict the potential distribution of R. ferrugineus in China according to both current climate data (1981–2010) and future climate warming estimates based on simulated climate data for the 2020s (2011–2040) provided by the Tyndall Center for Climate Change Research (TYN SC 2.0). Additionally, the Ecoclimatic Index (EI) values calculated for different climatic conditions (current and future, as simulated by the B2 scenario) were compared. Areas with a suitable climate for R. ferrugineus distribution were located primarily in central China according to the current climate data, with the northern boundary of the distribution reaching to 40.1°N and including Tibet, north Sichuan, central Shaanxi, south Shanxi, and east Hebei. There was little difference in the potential distribution predicted by the four emission scenarios according to future climate warming estimates. The primary prediction under future climate warming models was that, compared with the current climate model, the number of highly favorable habitats would increase significantly and expand into northern China, whereas the number of both favorable and marginally favorable habitats would decrease. Contrast analysis of EI values suggested that climate change and the density of site distribution were the main effectors of the changes in EI values. These results will help to improve control measures, prevent the spread of this pest, and revise the targeted quarantine areas. PMID:26496438
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Assessing the potential impacts of a changing climate on the distribution of a rabies virus vector
Piaggio, Antoinette J.
2018-01-01
Common vampire bats (Desmodus rotundus) occur throughout much of South America to northern México. Vampire bats have not been documented in recent history in the United States, but have been documented within about 50 km of the U.S. state of Texas. Vampire bats feed regularly on the blood of mammals and can transmit rabies virus to native species and livestock, causing impacts on the health of prey. Thus cattle producers, wildlife management agencies, and other stakeholders have expressed concerns about whether vampire bats might spread into the southern United States. On the other hand, concerns about vampire-borne rabies can also result in wanton destruction at bat roosts in areas occupied by vampire bats, but also in areas not known to be occupied by this species. This can in turn negatively affect some bat roosts, populations, and species that are of conservation concern, including vampire bats. To better understand the current and possible future distribution of vampire bats in North America and help mitigate future cattle management problems, we used 7,094 vampire bat occurrence records from North America and species distribution modeling (SDM) to map the potential distribution of vampire bats in North America under current and future climate change scenarios. We analysed and mapped the potential distribution of this species using 5 approaches to species distribution modeling: logistic regression, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy. We then projected these models into 17 “worst-case” future climate scenarios for year 2070 to generate hypotheses about how the vampire bat distribution in North America might change in the future. Of the variables used in this analysis, minimum temperature of the coldest month had the highest variable importance using all 5 SDM approaches. These results suggest two potential near-future routes of vampire bat dispersal into the U.S., one via southern Texas, and a second into southern Florida. Some of our SDM models support the hypothesis that suitable habitat for vampire bats may currently exist in parts of the México–U.S. borderlands, including extreme southern portions of Texas, as well as in southern Florida. However, this analysis also suggests that extensive expansion into the south-eastern and south-western U.S. over the coming ~60 years appears unlikely. PMID:29466401
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Assessing the potential impacts of a changing climate on the distribution of a rabies virus vector.
Hayes, Mark A; Piaggio, Antoinette J
2018-01-01
Common vampire bats (Desmodus rotundus) occur throughout much of South America to northern México. Vampire bats have not been documented in recent history in the United States, but have been documented within about 50 km of the U.S. state of Texas. Vampire bats feed regularly on the blood of mammals and can transmit rabies virus to native species and livestock, causing impacts on the health of prey. Thus cattle producers, wildlife management agencies, and other stakeholders have expressed concerns about whether vampire bats might spread into the southern United States. On the other hand, concerns about vampire-borne rabies can also result in wanton destruction at bat roosts in areas occupied by vampire bats, but also in areas not known to be occupied by this species. This can in turn negatively affect some bat roosts, populations, and species that are of conservation concern, including vampire bats. To better understand the current and possible future distribution of vampire bats in North America and help mitigate future cattle management problems, we used 7,094 vampire bat occurrence records from North America and species distribution modeling (SDM) to map the potential distribution of vampire bats in North America under current and future climate change scenarios. We analysed and mapped the potential distribution of this species using 5 approaches to species distribution modeling: logistic regression, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy. We then projected these models into 17 "worst-case" future climate scenarios for year 2070 to generate hypotheses about how the vampire bat distribution in North America might change in the future. Of the variables used in this analysis, minimum temperature of the coldest month had the highest variable importance using all 5 SDM approaches. These results suggest two potential near-future routes of vampire bat dispersal into the U.S., one via southern Texas, and a second into southern Florida. Some of our SDM models support the hypothesis that suitable habitat for vampire bats may currently exist in parts of the México-U.S. borderlands, including extreme southern portions of Texas, as well as in southern Florida. However, this analysis also suggests that extensive expansion into the south-eastern and south-western U.S. over the coming ~60 years appears unlikely.
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Chitale, Vishwas; Rijal, Srijana Joshi; Bisht, Neha; Shrestha, Bharat Babu
2018-01-01
Invasive alien plant species (IAPS) can pose severe threats to biodiversity and stability of native ecosystems, therefore, predicting the distribution of the IAPS plays a crucial role in effective planning and management of ecosystems. In the present study, we use Maximum Entropy (MaxEnt) modelling approach to predict the potential of distribution of eleven IAPS under future climatic conditions under RCP 2.6 and RCP 8.5 in part of Kailash sacred landscape region in Western Himalaya. Based on the model predictions, distribution of most of these invasive plants is expected to expand under future climatic scenarios, which might pose a serious threat to the native ecosystems through competition for resources in the study area. Native scrublands and subtropical needle-leaved forests will be the most affected ecosystems by the expansion of these IAPS. The present study is first of its kind in the Kailash Sacred Landscape in the field of invasive plants and the predictions of potential distribution under future climatic conditions from our study could help decision makers in planning and managing these forest ecosystems effectively. PMID:29664961
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Thapa, Sunil; Chitale, Vishwas; Rijal, Srijana Joshi; Bisht, Neha; Shrestha, Bharat Babu
2018-01-01
Invasive alien plant species (IAPS) can pose severe threats to biodiversity and stability of native ecosystems, therefore, predicting the distribution of the IAPS plays a crucial role in effective planning and management of ecosystems. In the present study, we use Maximum Entropy (MaxEnt) modelling approach to predict the potential of distribution of eleven IAPS under future climatic conditions under RCP 2.6 and RCP 8.5 in part of Kailash sacred landscape region in Western Himalaya. Based on the model predictions, distribution of most of these invasive plants is expected to expand under future climatic scenarios, which might pose a serious threat to the native ecosystems through competition for resources in the study area. Native scrublands and subtropical needle-leaved forests will be the most affected ecosystems by the expansion of these IAPS. The present study is first of its kind in the Kailash Sacred Landscape in the field of invasive plants and the predictions of potential distribution under future climatic conditions from our study could help decision makers in planning and managing these forest ecosystems effectively.
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Future distribution of tundra refugia in northern Alaska
Hope, Andrew G.; Waltari, Eric; Payer, David C.; Cook, Joseph A.; Talbot, Sandra L.
2013-01-01
Climate change in the Arctic is a growing concern for natural resource conservation and management as a result of accelerated warming and associated shifts in the distribution and abundance of northern species. We introduce a predictive framework for assessing the future extent of Arctic tundra and boreal biomes in northern Alaska. We use geo-referenced museum specimens to predict the velocity of distributional change into the next century and compare predicted tundra refugial areas with current land-use. The reliability of predicted distributions, including differences between fundamental and realized niches, for two groups of species is strengthened by fossils and genetic signatures of demographic shifts. Evolutionary responses to environmental change through the late Quaternary are generally consistent with past distribution models. Predicted future refugia overlap managed areas and indicate potential hotspots for tundra diversity. To effectively assess future refugia, variable responses among closely related species to climate change warrants careful consideration of both evolutionary and ecological histories.
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Measurements and Predictions for a Distributed Exhaust Nozzle
NASA Technical Reports Server (NTRS)
Kinzie, Kevin W.; Brown, Martha C.; Schein, David B.; Solomon, W. David, Jr.
2001-01-01
The acoustic and aerodynamic performance characteristics of a distributed exhaust nozzle (DEN) design concept were evaluated experimentally and analytically with the purpose of developing a design methodology for developing future DEN technology. Aerodynamic and acoustic measurements were made to evaluate the DEN performance and the CFD design tool. While the CFD approach did provide an excellent prediction of the flowfield and aerodynamic performance characteristics of the DEN and 2D reference nozzle, the measured acoustic suppression potential of this particular DEN was low. The measurements and predictions indicated that the mini-exhaust jets comprising the distributed exhaust coalesced back into a single stream jet very shortly after leaving the nozzles. Even so, the database provided here will be useful for future distributed exhaust designs with greater noise reduction and aerodynamic performance potential.
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Tanner, Evan P; Papeş, Monica; Elmore, R Dwayne; Fuhlendorf, Samuel D; Davis, Craig A
2017-01-01
Ecological niche models (ENMs) have increasingly been used to estimate the potential effects of climate change on species' distributions worldwide. Recently, predictions of species abundance have also been obtained with such models, though knowledge about the climatic variables affecting species abundance is often lacking. To address this, we used a well-studied guild (temperate North American quail) and the Maxent modeling algorithm to compare model performance of three variable selection approaches: correlation/variable contribution (CVC), biological (i.e., variables known to affect species abundance), and random. We then applied the best approach to forecast potential distributions, under future climatic conditions, and analyze future potential distributions in light of available abundance data and presence-only occurrence data. To estimate species' distributional shifts we generated ensemble forecasts using four global circulation models, four representative concentration pathways, and two time periods (2050 and 2070). Furthermore, we present distributional shifts where 75%, 90%, and 100% of our ensemble models agreed. The CVC variable selection approach outperformed our biological approach for four of the six species. Model projections indicated species-specific effects of climate change on future distributions of temperate North American quail. The Gambel's quail (Callipepla gambelii) was the only species predicted to gain area in climatic suitability across all three scenarios of ensemble model agreement. Conversely, the scaled quail (Callipepla squamata) was the only species predicted to lose area in climatic suitability across all three scenarios of ensemble model agreement. Our models projected future loss of areas for the northern bobwhite (Colinus virginianus) and scaled quail in portions of their distributions which are currently areas of high abundance. Climatic variables that influence local abundance may not always scale up to influence species' distributions. Special attention should be given to selecting variables for ENMs, and tests of model performance should be used to validate the choice of variables.
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Is Solar Energy the Fuel of the Future?
ERIC Educational Resources Information Center
Cetincelik, Mauammer
1974-01-01
Describes the present distribution of solar energy, traces its use through history, explores its potential utilization in the future, and presents the effects of the use of solar energy on pollution. (GS)
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Potential distribution dataset of honeybees in Indian Ocean Islands: Case study of Zanzibar Island.
Mwalusepo, Sizah; Muli, Eliud; Nkoba, Kiatoko; Nguku, Everlyn; Kilonzo, Joseph; Abdel-Rahman, Elfatih M; Landmann, Tobias; Fakih, Asha; Raina, Suresh
2017-10-01
Honeybees ( Apis mellifera ) are principal insect pollinators, whose worldwide distribution and abundance is known to largely depend on climatic conditions. However, the presence records dataset on potential distribution of honeybees in Indian Ocean Islands remain less documented. Presence records in shape format and probability of occurrence of honeybees with different temperature change scenarios is provided in this article across Zanzibar Island. Maximum entropy (Maxent) package was used to analyse the potential distribution of honeybees. The dataset provides information on the current and future distribution of the honey bees in Zanzibar Island. The dataset is of great importance for improving stakeholders understanding of the role of temperature change on the spatial distribution of honeybees.
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Archis, Jennifer N; Akcali, Christopher; Stuart, Bryan L; Kikuchi, David; Chunco, Amanda J
2018-01-01
Anthropogenic climate change is a significant global driver of species distribution change. Although many species have undergone range expansion at their poleward limits, data on several taxonomic groups are still lacking. A common method for studying range shifts is using species distribution models to evaluate current, and predict future, distributions. Notably, many sources of 'current' climate data used in species distribution modeling use the years 1950-2000 to calculate climatic averages. However, this does not account for recent (post 2000) climate change. This study examines the influence of climate change on the eastern coral snake ( Micrurus fulvius ). Specifically, we: (1) identified the current range and suitable environment of M. fulvius in the Southeastern United States, (2) investigated the potential impacts of climate change on the distribution of M. fulvius , and (3) evaluated the utility of future models in predicting recent (2001-2015) records. We used the species distribution modeling program Maxent and compared both current (1950-2000) and future (2050) climate conditions. Future climate models showed a shift in the distribution of suitable habitat across a significant portion of the range; however, results also suggest that much of the Southeastern United States will be outside the range of current conditions, suggesting that there may be no-analog environments in the future. Most strikingly, future models were more effective than the current models at predicting recent records, suggesting that range shifts may already be occurring. These results have implications for both M. fulvius and its Batesian mimics. More broadly, we recommend future Maxent studies consider using future climate data along with current data to better estimate the current distribution.
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Past and ongoing shifts in Joshua tree distribution support future modeled range contraction
Cole, Kenneth L.; Ironside, Kirsten; Eischeid, Jon K.; Garfin, Gregg; Duffy, Phil; Toney, Chris
2011-01-01
The future distribution of the Joshua tree (Yucca brevifolia) is projected by combining a geostatistical analysis of 20th-century climates over its current range, future modeled climates, and paleoecological data showing its response to a past similar climate change. As climate rapidly warmed ;11 700 years ago, the range of Joshua tree contracted, leaving only the populations near what had been its northernmost limit. Its ability to spread northward into new suitable habitats after this time may have been inhibited by the somewhat earlier extinction of megafaunal dispersers, especially the Shasta ground sloth. We applied a model of climate suitability for Joshua tree, developed from its 20th-century range and climates, to future climates modeled through a set of six individual general circulation models (GCM) and one suite of 22 models for the late 21st century. All distribution data, observed climate data, and future GCM results were scaled to spatial grids of ;1 km and ;4 km in order to facilitate application within this topographically complex region. All of the models project the future elimination of Joshua tree throughout most of the southern portions of its current range. Although estimates of future monthly precipitation differ between the models, these changes are outweighed by large increases in temperature common to all the models. Only a few populations within the current range are predicted to be sustainable. Several models project significant potential future expansion into new areas beyond the current range, but the species' Historical and current rates of dispersal would seem to prevent natural expansion into these new areas. Several areas are predicted to be potential sites for relocation/ assisted migration. This project demonstrates how information from paleoecology and modern ecology can be integrated in order to understand ongoing processes and future distributions.
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Climate Change Impacts on the Potential Distribution of Eogystia hippophaecolus in China.
Li, Xue; Ge, Xuezhen; Chen, Linghong; Zhang, Linjing; Wang, Tao; Shixiang, Zong
2018-05-28
Seabuckthorn carpenter moth, Eogystia hippophaecolus (Hua, Chou, Fang, & Chen, 1990), is the most important boring pest of sea buckthorn (Hippophae rhamnoides L.) in the northwest of China. It is responsible for the death of large areas of H. rhamnoides forest, seriously affecting the ecological environment and economic development in northwestern China. To clarify the potential distribution of E. hippophaecolus in China, the present study used the CLIMEX 4.0.0 model to project the potential distribution of the pest using historical climate data (1981-2010) and simulated future climate data (2011-2100) for China. Under historical climate condition, E. hippophaecolus would be found to be distributed mainly between 27° N - 51° N and 74° E - 134° E, with favorable and highly favorable habitats accounting for 35.2% of the total potential distribution. Under future climate conditions, E. hippophaecolus would be distributed mainly between 27° N - 53° N and 74° E - 134° E, with the possibility of moving in a northwest direction. Under these conditions, the proportion of the total area providing a favorable and highly favorable habitat may decrease to about 33%. These results will help to identify the impact of climate change on the potential distribution of E. hippophaecolus, thereby providing a theoretical basis for monitoring and early forecasting of pest outbreaks. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
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Naish, Suchithra; Mengersen, Kerrie; Hu, Wenbiao; Tong, Shilu
2013-01-01
Mosquito-borne diseases are climate sensitive and there has been increasing concern over the impact of climate change on future disease risk. This paper projected the potential future risk of Barmah Forest virus (BFV) disease under climate change scenarios in Queensland, Australia. We obtained data on notified BFV cases, climate (maximum and minimum temperature and rainfall), socio-economic and tidal conditions for current period 2000-2008 for coastal regions in Queensland. Grid-data on future climate projections for 2025, 2050 and 2100 were also obtained. Logistic regression models were built to forecast the otential risk of BFV disease distribution under existing climatic, socio-economic and tidal conditions. The model was applied to estimate the potential geographic distribution of BFV outbreaks under climate change scenarios. The predictive model had good model accuracy, sensitivity and specificity. Maps on potential risk of future BFV disease indicated that disease would vary significantly across coastal regions in Queensland by 2100 due to marked differences in future rainfall and temperature projections. We conclude that the results of this study demonstrate that the future risk of BFV disease would vary across coastal regions in Queensland. These results may be helpful for public health decision making towards developing effective risk management strategies for BFV disease control and prevention programs in Queensland.
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Abolafya, Moris; Onmuş, Ortaç; Şekercioğlu, Çağan H.; Bilgin, Raşit
2013-01-01
In this study, we evaluated the potential impact of climate change on the distributions of Turkey’s songbirds in the 21st century by modelling future distributions of 20 resident and nine migratory species under two global climate change scenarios. We combined verified data from an ornithological citizen science initiative (www.kusbank.org) with maximum entropy modeling and eight bioclimatic variables to estimate species distributions and projections for future time periods. Model predictions for resident and migratory species showed high variability, with some species projected to lose and others projected to gain suitable habitat. Our study helps improve the understanding of the current and potential future distributions of Turkey’s songbirds and their responses to climate change, highlights effective strategies to maximize avian conservation efforts in the study region, and provides a model for using citizen science data for biodiversity research in a large developing country with few professional field biologists. Our results demonstrate that climate change will not affect every species equally in Turkey. Expected range reductions in some breeding species will increase the risk of local extinction, whereas others are likely to expand their ranges. PMID:23844151
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Abolafya, Moris; Onmuş, Ortaç; Şekercioğlu, Çağan H; Bilgin, Raşit
2013-01-01
In this study, we evaluated the potential impact of climate change on the distributions of Turkey's songbirds in the 21st century by modelling future distributions of 20 resident and nine migratory species under two global climate change scenarios. We combined verified data from an ornithological citizen science initiative (www.kusbank.org) with maximum entropy modeling and eight bioclimatic variables to estimate species distributions and projections for future time periods. Model predictions for resident and migratory species showed high variability, with some species projected to lose and others projected to gain suitable habitat. Our study helps improve the understanding of the current and potential future distributions of Turkey's songbirds and their responses to climate change, highlights effective strategies to maximize avian conservation efforts in the study region, and provides a model for using citizen science data for biodiversity research in a large developing country with few professional field biologists. Our results demonstrate that climate change will not affect every species equally in Turkey. Expected range reductions in some breeding species will increase the risk of local extinction, whereas others are likely to expand their ranges.
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Ge, Xuezhen; He, Shanyong; Zhu, Chenyi; Wang, Tao; Xu, Zhichun; Shixiang, Zong
2018-05-23
The international invasive and quarantined defoliating insect Hyphantria cunea Drury (Lepidoptera: Arctiidae) causes huge ecological and economic losses in the world. The future climate change may alter the distribution of H. cunea and aggravate the damage. In the present study, we used CLIMEX to project the potential global distribution of H. cunea according to both historical climate data (1950-2000) and future climate warming estimates (2011-2100) to define the impact of climate change. Under the historical climate scenario, we found that H. cunea can survive on every continent, and temperature is the main factor that limits its establishment. With climate change, the suitability will increase in middle and high latitude regions, while decrease in the low latitude regions. Besides, tropic regions will be most sensitive to the climate change impacts for the pest to survive. The impacts of climate change will also increase over time, whether the positive impacts or negative impacts. The projected potential distributions provide a theoretical basis for quarantine and control strategies for the management of this pest in each country. Furthermore, these results provide substantial guidance for studies of the effects of climate change on other major forest pests. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
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Dyer, Joseph J.; Brewer, Shannon K.; Worthington, Thomas A.; Bergey, Elizabeth A.
2013-01-01
1.A major limitation to effective management of narrow-range crayfish populations is the paucity of information on the spatial distribution of crayfish species and a general understanding of the interacting environmental variables that drive current and future potential distributional patterns. 2.Maximum Entropy Species Distribution Modeling Software (MaxEnt) was used to predict the current and future potential distributions of four endemic crayfish species in the Ouachita Mountains. Current distributions were modelled using climate, geology, soils, land use, landform and flow variables thought to be important to lotic crayfish. Potential changes in the distribution were forecast by using models trained on current conditions and projecting onto the landscape predicted under climate-change scenarios. 3.The modelled distribution of the four species closely resembled the perceived distribution of each species but also predicted populations in streams and catchments where they had not previously been collected. Soils, elevation and winter precipitation and temperature most strongly related to current distributions and represented 6587% of the predictive power of the models. Model accuracy was high for all models, and model predictions of new populations were verified through additional field sampling. 4.Current models created using two spatial resolutions (1 and 4.5km2) showed that fine-resolution data more accurately represented current distributions. For three of the four species, the 1-km2 resolution models resulted in more conservative predictions. However, the modelled distributional extent of Orconectes leptogonopodus was similar regardless of data resolution. Field validations indicated 1-km2 resolution models were more accurate than 4.5-km2 resolution models. 5.Future projected (4.5-km2 resolution models) model distributions indicated three of the four endemic species would have truncated ranges with low occurrence probabilities under the low-emission scenario, whereas two of four species would be severely restricted in range under moderatehigh emissions. Discrepancies in the two emission scenarios probably relate to the exclusion of behavioural adaptations from species-distribution models. 6.These model predictions illustrate possible impacts of climate change on narrow-range endemic crayfish populations. The predictions do not account for biotic interactions, migration, local habitat conditions or species adaptation. However, we identified the constraining landscape features acting on these populations that provide a framework for addressing habitat needs at a fine scale and developing targeted and systematic monitoring programmes.
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Impacts of Climate Change on the Global Invasion Potential of the African Clawed Frog Xenopus laevis
Ihlow, Flora; Courant, Julien; Secondi, Jean; Herrel, Anthony; Rebelo, Rui; Measey, G. John; Lillo, Francesco; De Villiers, F. André; Vogt, Solveig; De Busschere, Charlotte; Backeljau, Thierry; Rödder, Dennis
2016-01-01
By altering or eliminating delicate ecological relationships, non-indigenous species are considered a major threat to biodiversity, as well as a driver of environmental change. Global climate change affects ecosystems and ecological communities, leading to changes in the phenology, geographic ranges, or population abundance of several species. Thus, predicting the impacts of global climate change on the current and future distribution of invasive species is an important subject in macroecological studies. The African clawed frog (Xenopus laevis), native to South Africa, possesses a strong invasion potential and populations have become established in numerous countries across four continents. The global invasion potential of X. laevis was assessed using correlative species distribution models (SDMs). SDMs were computed based on a comprehensive set of occurrence records covering South Africa, North America, South America and Europe and a set of nine environmental predictors. Models were built using both a maximum entropy model and an ensemble approach integrating eight algorithms. The future occurrence probabilities for X. laevis were subsequently computed using bioclimatic variables for 2070 following four different IPCC scenarios. Despite minor differences between the statistical approaches, both SDMs predict the future potential distribution of X. laevis, on a global scale, to decrease across all climate change scenarios. On a continental scale, both SDMs predict decreasing potential distributions in the species’ native range in South Africa, as well as in the invaded areas in North and South America, and in Australia where the species has not been introduced. In contrast, both SDMs predict the potential range size to expand in Europe. Our results suggest that all probability classes will be equally affected by climate change. New regional conditions may promote new invasions or the spread of established invasive populations, especially in France and Great Britain. PMID:27248830
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Ihlow, Flora; Courant, Julien; Secondi, Jean; Herrel, Anthony; Rebelo, Rui; Measey, G John; Lillo, Francesco; De Villiers, F André; Vogt, Solveig; De Busschere, Charlotte; Backeljau, Thierry; Rödder, Dennis
2016-01-01
By altering or eliminating delicate ecological relationships, non-indigenous species are considered a major threat to biodiversity, as well as a driver of environmental change. Global climate change affects ecosystems and ecological communities, leading to changes in the phenology, geographic ranges, or population abundance of several species. Thus, predicting the impacts of global climate change on the current and future distribution of invasive species is an important subject in macroecological studies. The African clawed frog (Xenopus laevis), native to South Africa, possesses a strong invasion potential and populations have become established in numerous countries across four continents. The global invasion potential of X. laevis was assessed using correlative species distribution models (SDMs). SDMs were computed based on a comprehensive set of occurrence records covering South Africa, North America, South America and Europe and a set of nine environmental predictors. Models were built using both a maximum entropy model and an ensemble approach integrating eight algorithms. The future occurrence probabilities for X. laevis were subsequently computed using bioclimatic variables for 2070 following four different IPCC scenarios. Despite minor differences between the statistical approaches, both SDMs predict the future potential distribution of X. laevis, on a global scale, to decrease across all climate change scenarios. On a continental scale, both SDMs predict decreasing potential distributions in the species' native range in South Africa, as well as in the invaded areas in North and South America, and in Australia where the species has not been introduced. In contrast, both SDMs predict the potential range size to expand in Europe. Our results suggest that all probability classes will be equally affected by climate change. New regional conditions may promote new invasions or the spread of established invasive populations, especially in France and Great Britain.
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Rödder, Dennis; Kielgast, Jos; Lötters, Stefan
2010-11-01
Anthropogenic climate change poses a major threat to global biodiversity with a potential to alter biological interactions at all spatial scales. Amphibians are the most threatened vertebrates and have been subject to increasing conservation attention over the past decade. A particular concern is the pandemic emergence of the parasitic chytrid fungus Batrachochytrium dendrobatidis, which has been identified as the cause of extremely rapid large-scale declines and species extinctions. Experimental and observational studies have demonstrated that the host-pathogen system is strongly influenced by climatic parameters and thereby potentially affected by climate change. Herein we project a species distribution model of the pathogen onto future climatic scenarios generated by the IPCC to examine their potential implications on the pandemic. Results suggest that predicted anthropogenic climate change may reduce the geographic range of B. dendrobatidis and its potential influence on amphibian biodiversity.
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Dai, Guanghui; Yang, Jun; Lu, Siran; Huang, Conghong; Jin, Jing; Jiang, Peng; Yan, Pengbo
2018-01-18
Biodiesel produced from woody oil plants is considered a green substitute for fossil fuels. However, a potential negative impact of growing woody oil plants on a large scale is the introduction of highly invasive species into susceptible regions. In this study, we examined the potential invasion risk of woody oil plants in China's protected areas under future climate conditions. We simulated the current and future potential distributions of three invasive woody oil plants, Jatropha curcas, Ricinus communis, and Aleurites moluccana, under two climate change scenarios (RCP2.6 and RCP8.5) up to 2050 using species distribution models. Protected areas in China that will become susceptible to these species were then identified using a spatial overlay analysis. Our results showed that by 2050, 26 and 41 protected areas would be threatened by these invasive woody oil plants under scenarios RCP2.6 and RCP8.5, respectively. A total of 10 unique forest ecosystems and 17 rare plant species could be potentially affected. We recommend that the invasive potential of woody oil plants be fully accounted for when developing forest-based biodiesel, especially around protected areas.
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Louis R. Iverson; Anantha Prasad; Mark W. Schwartz; Mark W. Schwartz
1999-01-01
We are using a deterministic regression tree analysis model (DISTRIB) and a stochastic migration model (SHIFT) to examine potential distributions of ~66 individual species of eastern US trees under a 2 x CO2 climate change scenario. This process is demonstrated for Virginia pine (Pinus virginiana).
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Saupe, Erin E.; Papes, Monica; Selden, Paul A.; Vetter, Richard S.
2011-01-01
Most spiders use venom to paralyze their prey and are commonly feared for their potential to cause injury to humans. In North America, one species in particular, Loxosceles reclusa (brown recluse spider, Sicariidae), causes the majority of necrotic wounds induced by the Araneae. However, its distributional limitations are poorly understood and, as a result, medical professionals routinely misdiagnose brown recluse bites outside endemic areas, confusing putative spider bites for other serious conditions. To address the issue of brown recluse distribution, we employ ecological niche modeling to investigate the present and future distributional potential of this species. We delineate range boundaries and demonstrate that under future climate change scenarios, the spider's distribution may expand northward, invading previously unaffected regions of the USA. At present, the spider's range is centered in the USA, from Kansas east to Kentucky and from southern Iowa south to Louisiana. Newly influenced areas may include parts of Nebraska, Minnesota, Wisconsin, Michigan, South Dakota, Ohio, and Pennsylvania. These results illustrate a potential negative consequence of climate change on humans and will aid medical professionals in proper bite identification/treatment, potentially reducing bite misdiagnoses. PMID:21464985
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Wang, Rulin; Li, Qing; He, Shisong; Liu, Yuan; Wang, Mingtian; Jiang, Gan
2018-01-01
Bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is a major threat to the kiwifruit industry throughout the world and accounts for substantial economic losses in China. The aim of the present study was to test and explore the possibility of using MaxEnt (maximum entropy models) to predict and analyze the future large-scale distribution of Psa in China. Based on the current environmental factors, three future climate scenarios, which were suggested by the fifth IPCC report, and the current distribution sites of Psa, MaxEnt combined with ArcGIS was applied to predict the potential suitable areas and the changing trend of Psa in China. The jackknife test and correlation analysis were used to choose dominant climatic factors. The receiver operating characteristic curve (ROC) drawn by MaxEnt was used to evaluate the accuracy of the simulation. The results showed that under current climatic conditions, the area from latitude 25° to 36°N and from longitude 101° to 122°E is the primary potential suitable area of Psa in China. The highly suitable area (with suitability between 66 and 100) was mainly concentrated in Northeast Sichuan, South Shaanxi, most of Chongqing, West Hubei and Southwest Gansu and occupied 4.94% of land in China. Under different future emission scenarios, both the areas and the centers of the suitable areas all showed differences compared with the current situation. Four climatic variables, i.e., maximum April temperature (19%), mean temperature of the coldest quarter (14%), precipitation in May (11.5%) and minimum temperature in October (10.8%), had the largest impact on the distribution of Psa. The MaxEnt model is potentially useful for forecasting the future adaptive distribution of Psa under climate change, and it provides important guidance for comprehensive management.
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Distribution and diversity of twelve Curcuma species in China.
Zhang, Lanyue; Wei, Jingwen; Yang, Zhiwen; Chen, Feng; Xian, Qiqiu; Su, Ping; Pan, Wanyi; Zhang, Kun; Zheng, Xi; Du, Zhiyun
2018-02-01
Genus Curcuma a wild species presents an important source of valuable characters for improving the cultivated Curcuma varieties. Based on the collected germplasms, herbariums, field surveys and other literatures, the ecogeographical diversity of Genus Curcuma and its potential distributions under the present and future climate are analysed by DIVA-GIS. The results indicate Genus Curcuma is distributed over 17 provinces in China, and particularly abundant in Guangxi and Guangdong provinces. The simulated current distributions are close to the actual distribution regions. In the future climate, the suitable areas for four Curcuma species will be extended, while for other three species the regions will be significantly decreased, and thus these valuable resources need protecting.
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Naish, Suchithra; Mengersen, Kerrie; Hu, Wenbiao; Tong, Shilu
2013-01-01
Background Mosquito-borne diseases are climate sensitive and there has been increasing concern over the impact of climate change on future disease risk. This paper projected the potential future risk of Barmah Forest virus (BFV) disease under climate change scenarios in Queensland, Australia. Methods/Principal Findings We obtained data on notified BFV cases, climate (maximum and minimum temperature and rainfall), socio-economic and tidal conditions for current period 2000–2008 for coastal regions in Queensland. Grid-data on future climate projections for 2025, 2050 and 2100 were also obtained. Logistic regression models were built to forecast the otential risk of BFV disease distribution under existing climatic, socio-economic and tidal conditions. The model was applied to estimate the potential geographic distribution of BFV outbreaks under climate change scenarios. The predictive model had good model accuracy, sensitivity and specificity. Maps on potential risk of future BFV disease indicated that disease would vary significantly across coastal regions in Queensland by 2100 due to marked differences in future rainfall and temperature projections. Conclusions/Significance We conclude that the results of this study demonstrate that the future risk of BFV disease would vary across coastal regions in Queensland. These results may be helpful for public health decision making towards developing effective risk management strategies for BFV disease control and prevention programs in Queensland. PMID:23690959
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NASA Technical Reports Server (NTRS)
Golombeck, M.; Rapp, D.
1996-01-01
The size-frequency distribution of rocks and the Vicking landing sites and a variety of rocky locations on the Earth that formed from a number of geologic processes all have the general shape of simple exponential curves, which have been combined with remote sensing data and models on rock abundance to predict the frequency of boulders potentially hazardous to future Mars landers and rovers.
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Ceccarelli, Soledad; Rabinovich, Jorge E
2015-11-01
We analyzed the possible effects of global climate change on the potential geographic distribution in Venezuela of five species of triatomines (Eratyrus mucronatus (Stal, 1859), Panstrongylus geniculatus (Latreille, 1811), Rhodnius prolixus (Stål, 1859), Rhodnius robustus (Larrousse, 1927), and Triatoma maculata (Erichson, 1848)), vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. To obtain the future potential geographic distributions, expressed as climatic niche suitability, we modeled the presences of these species using two IPCC (Intergovernmental Panel on Climate Change) future emission scenarios of global climate change (A1B and B1), the Global Climate model CSIRO Mark 3.0, and three periods of future projections (years 2020, 2060, and 2080). After estimating with the MaxEnt software the future climatic niche suitability for each species, scenario, and period of future projections, we estimated a series of indexes of Venezuela's vulnerability at the county, state, and country level, measured as the number of people exposed due to the changes in the geographical distribution of the five triatomine species analyzed. Despite that this is not a measure of the risk of Chagas disease transmission, we conclude that possible future effects of global climate change on the Venezuelan population vulnerability show a slightly decreasing trend, even taking into account future population growth; we can expect fewer locations in Venezuela where an average Venezuelan citizen would be exposed to triatomines in the next 50-70 yr. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Vutukuru, Satish; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald
2011-12-01
Distributed power generation-electricity generation that is produced by many small stationary power generators distributed throughout an urban air basin-has the potential to supply a significant portion of electricity in future years. As a result, distributed generation may lead to increased pollutant emissions within an urban air basin, which could adversely affect air quality. However, the use of combined heating and power with distributed generation may reduce the energy consumption for space heating and air conditioning, resulting in a net decrease of pollutant and greenhouse gas emissions. This work used a systematic approach based on land-use geographical information system data to determine the spatial and temporal distribution of distributed generation emissions in the San Joaquin Valley Air Basin of California and simulated the potential air quality impacts using state-of-the-art three-dimensional computer models. The evaluation of the potential market penetration of distributed generation focuses on the year 2023. In general, the air quality impacts of distributed generation were found to be small due to the restrictive 2007 California Air Resources Board air emission standards applied to all distributed generation units and due to the use of combined heating and power. Results suggest that if distributed generation units were allowed to emit at the current Best Available Control Technology standards (which are less restrictive than the 2007 California Air Resources Board standards), air quality impacts of distributed generation could compromise compliance with the federal 8-hr average ozone standard in the region.
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Vutukuru, Satish; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald
2011-12-01
Distributed power generation-electricity generation that is produced by many small stationary power generators distributed throughout an urban air basin-has the potential to supply a significant portion of electricity in future years. As a result, distributed generation may lead to increased pollutant emissions within an urban air basin, which could adversely affect air quality. However, the use of combined heating and power with distributed generation may reduce the energy consumption for space heating and air conditioning, resulting in a net decrease of pollutant and greenhouse gas emissions. This work used a systematic approach based on land-use geographical information system data to determine the spatial and temporal distribution of distributed generation emissions in the San Joaquin Valley Air Basin of California and simulated the potential air quality impacts using state-of-the-art three-dimensional computer models. The evaluation of the potential market penetration of distributed generation focuses on the year 2023. In general, the air quality impacts of distributed generation were found to be small due to the restrictive 2007 California Air Resources Board air emission standards applied to all distributed generation units and due to the use of combined heating and power. Results suggest that if distributed generation units were allowed to emit at the current Best Available Control Technology standards (which are less restrictive than the 2007 California Air Resources Board standards), air quality impacts of distributed generation could compromise compliance with the federal 8-hr average ozone standard in the region. [Box: see text].
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Rounaghi, Iman; Hosseinian Yousefkhani, Seyyed Saeed
2018-01-01
Genus Pseudotrapelus has a wide distribution in North Africa and in the Middle East. In the present study, we modeled the habitat suitability of two Omani species of the genus (Pseudotrapelus dhofarensis and Pseudotrapelus jensvindumi) to evaluate the potential effects of climate change on their distribution. Mean diurnal range and precipitation of wettest quarter are the most highly contributed variables for P. jensvindumi and P. dhofarensis, respectively. The potential distribution for P. dhofarensis in the current time covers the southern coastal regions of Oman, Yemen, the Horn of Africa, and Socotra Island, but the suitable regions were reduced in the future prediction and limited to Yemen, Socotra Island, and Oman. There have not been any records of the species outside of Oman. Analysis of habitat suitability for P. jensvindumi indicated that the species is restricted to the Al Hajar Mountain of Oman and the southeast coastal region of Iran, but there are no records of the species from Iran. Because mean diurnal range will not be influenced by climate change in future, the potential distribution of the species is not expected to be changed in 2050. All predicted models were performed with the highest AUC (more than 0.97) using the Maxent method. Investigation to find unknown populations of these two species in Iran, Yemen, and Socotra Island is essential for developing conservation programs in the future.
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Perspective on the span-distributed-load concept for application to large cargo aircraft design
NASA Technical Reports Server (NTRS)
Whitehead, A. H., Jr.
1975-01-01
Results of a simplified analysis of the span-distributed-load concept (in which payload is placed within the wing structure) are presented. It is shown that a design based on these principles has a high potential for application to future large air cargo transport. Significant improvements are foreseen in increased payload fraction and productivity and in reduced fuel consumption and operating costs. A review of the efforts in the 1940's to develop all-wing aircraft shows the potential of transferring those early technological developments to current design of distributed-load aircraft. Current market analyses are projected to 1990 to show the future commercial demand for large capacity freighters. Several configuration designs which would serve different market requirements for these large freighters are discussed as are some of the pacing-technology requirements.
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Castillo, Andrea G; Alò, Dominique; González, Benito A; Samaniego, Horacio
2018-01-01
The main goal of this contribution was to define the ecological niche of the guanaco ( Lama guanicoe ), to describe potential distributional changes, and to assess the relative importance of niche conservatism and divergence processes between the two lineages described for the species ( L.g. cacsilensis and L.g. guanicoe ). We used maximum entropy to model lineage's climate niche from 3,321 locations throughout continental Chile, and developed future niche models under climate change for two extreme greenhouse gas emission scenarios (RCP2.6 and RCP8.5). We evaluated changes of the environmental niche and future distribution of the largest mammal in the Southern Cone of South America. Evaluation of niche conservatism and divergence were based on identity and background similarity tests. We show that: (a) the current geographic distribution of lineages is associated with different climatic requirements that are related to the geographic areas where these lineages are located; (b) future distribution models predict a decrease in the distribution surface under both scenarios; (c) a 3% decrease of areal protection is expected if the current distribution of protected areas is maintained, and this is expected to occur at the expense of a large reduction of high quality habitats under the best scenario; (d) current and future distribution ranges of guanaco mostly adhere to phylogenetic niche divergence hypotheses between lineages. Associating environmental variables with species ecological niche seems to be an important aspect of unveiling the particularities of, both evolutionary patterns and ecological features that species face in a changing environment. We report specific descriptions of how these patterns may play out under the most extreme climate change predictions and provide a grim outlook of the future potential distribution of guanaco in Chile. From an ecological perspective, while a slightly smaller distribution area is expected, this may come with an important reduction of available quality habitats. From the evolutionary perspective, we describe the limitations of this taxon as it experiences forces imposed by climate change dynamics.
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Castillo, Andrea G.; González, Benito A.
2018-01-01
Background The main goal of this contribution was to define the ecological niche of the guanaco (Lama guanicoe), to describe potential distributional changes, and to assess the relative importance of niche conservatism and divergence processes between the two lineages described for the species (L.g. cacsilensis and L.g. guanicoe). Methods We used maximum entropy to model lineage’s climate niche from 3,321 locations throughout continental Chile, and developed future niche models under climate change for two extreme greenhouse gas emission scenarios (RCP2.6 and RCP8.5). We evaluated changes of the environmental niche and future distribution of the largest mammal in the Southern Cone of South America. Evaluation of niche conservatism and divergence were based on identity and background similarity tests. Results We show that: (a) the current geographic distribution of lineages is associated with different climatic requirements that are related to the geographic areas where these lineages are located; (b) future distribution models predict a decrease in the distribution surface under both scenarios; (c) a 3% decrease of areal protection is expected if the current distribution of protected areas is maintained, and this is expected to occur at the expense of a large reduction of high quality habitats under the best scenario; (d) current and future distribution ranges of guanaco mostly adhere to phylogenetic niche divergence hypotheses between lineages. Discussion Associating environmental variables with species ecological niche seems to be an important aspect of unveiling the particularities of, both evolutionary patterns and ecological features that species face in a changing environment. We report specific descriptions of how these patterns may play out under the most extreme climate change predictions and provide a grim outlook of the future potential distribution of guanaco in Chile. From an ecological perspective, while a slightly smaller distribution area is expected, this may come with an important reduction of available quality habitats. From the evolutionary perspective, we describe the limitations of this taxon as it experiences forces imposed by climate change dynamics. PMID:29868293
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Casajus, Nicolas; Périé, Catherine; Logan, Travis; Lambert, Marie-Claude; de Blois, Sylvie; Berteaux, Dominique
2016-01-01
An impressive number of new climate change scenarios have recently become available to assess the ecological impacts of climate change. Among these impacts, shifts in species range analyzed with species distribution models are the most widely studied. Whereas it is widely recognized that the uncertainty in future climatic conditions must be taken into account in impact studies, many assessments of species range shifts still rely on just a few climate change scenarios, often selected arbitrarily. We describe a method to select objectively a subset of climate change scenarios among a large ensemble of available ones. Our k-means clustering approach reduces the number of climate change scenarios needed to project species distributions, while retaining the coverage of uncertainty in future climate conditions. We first show, for three biologically-relevant climatic variables, that a reduced number of six climate change scenarios generates average climatic conditions very close to those obtained from a set of 27 scenarios available before reduction. A case study on potential gains and losses of habitat by three northeastern American tree species shows that potential future species distributions projected from the selected six climate change scenarios are very similar to those obtained from the full set of 27, although with some spatial discrepancies at the edges of species distributions. In contrast, projections based on just a few climate models vary strongly according to the initial choice of climate models. We give clear guidance on how to reduce the number of climate change scenarios while retaining the central tendencies and coverage of uncertainty in future climatic conditions. This should be particularly useful during future climate change impact studies as more than twice as many climate models were reported in the fifth assessment report of IPCC compared to the previous one. PMID:27015274
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Casajus, Nicolas; Périé, Catherine; Logan, Travis; Lambert, Marie-Claude; de Blois, Sylvie; Berteaux, Dominique
2016-01-01
An impressive number of new climate change scenarios have recently become available to assess the ecological impacts of climate change. Among these impacts, shifts in species range analyzed with species distribution models are the most widely studied. Whereas it is widely recognized that the uncertainty in future climatic conditions must be taken into account in impact studies, many assessments of species range shifts still rely on just a few climate change scenarios, often selected arbitrarily. We describe a method to select objectively a subset of climate change scenarios among a large ensemble of available ones. Our k-means clustering approach reduces the number of climate change scenarios needed to project species distributions, while retaining the coverage of uncertainty in future climate conditions. We first show, for three biologically-relevant climatic variables, that a reduced number of six climate change scenarios generates average climatic conditions very close to those obtained from a set of 27 scenarios available before reduction. A case study on potential gains and losses of habitat by three northeastern American tree species shows that potential future species distributions projected from the selected six climate change scenarios are very similar to those obtained from the full set of 27, although with some spatial discrepancies at the edges of species distributions. In contrast, projections based on just a few climate models vary strongly according to the initial choice of climate models. We give clear guidance on how to reduce the number of climate change scenarios while retaining the central tendencies and coverage of uncertainty in future climatic conditions. This should be particularly useful during future climate change impact studies as more than twice as many climate models were reported in the fifth assessment report of IPCC compared to the previous one.
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Williams, Hefin Wyn; Cross, Dónall Eoin; Crump, Heather Louise; Drost, Cornelis Jan; Thomas, Christopher James
2015-08-28
There is increasing evidence that the geographic distribution of tick species is changing. Whilst correlative Species Distribution Models (SDMs) have been used to predict areas that are potentially suitable for ticks, models have often been assessed without due consideration for spatial patterns in the data that may inflate the influence of predictor variables on species distributions. This study used null models to rigorously evaluate the role of climate and the potential for climate change to affect future climate suitability for eight European tick species, including several important disease vectors. We undertook a comparative assessment of the performance of Maxent and Mahalanobis Distance SDMs based on observed data against those of null models based on null species distributions or null climate data. This enabled the identification of species whose distributions demonstrate a significant association with climate variables. Latest generation (AR5) climate projections were subsequently used to project future climate suitability under four Representative Concentration Pathways (RCPs). Seven out of eight tick species exhibited strong climatic signals within their observed distributions. Future projections intimate varying degrees of northward shift in climate suitability for these tick species, with the greatest shifts forecasted under the most extreme RCPs. Despite the high performance measure obtained for the observed model of Hyalomma lusitanicum, it did not perform significantly better than null models; this may result from the effects of non-climatic factors on its distribution. By comparing observed SDMs with null models, our results allow confidence that we have identified climate signals in tick distributions that are not simply a consequence of spatial patterns in the data. Observed climate-driven SDMs for seven out of eight species performed significantly better than null models, demonstrating the vulnerability of these tick species to the effects of climate change in the future.
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A tool to assess potential for alien plant establishment and expansion under climate change.
Roger, Erin; Duursma, Daisy Englert; Downey, Paul O; Gallagher, Rachael V; Hughes, Lesley; Steel, Jackie; Johnson, Stephen B; Leishman, Michelle R
2015-08-15
Predicting the influence of climate change on the potential distribution of naturalised alien plant species is an important and challenging task. While prioritisation of management actions for alien plants under current climatic conditions has been widely adopted, very few systems explicitly incorporate the potential of future changes in climate conditions to influence the distribution of alien plant species. Here, we develop an Australia-wide screening tool to assess the potential of naturalised alien plants to establish and spread under both current and future climatic conditions. The screening tool developed uses five spatially explicit criteria to establish the likelihood of alien plant population establishment and expansion under baseline climate conditions and future climates for the decades 2035 and 2065. Alien plants are then given a threat rating according to current and future threat to enable natural resource managers to focus on those species that pose the largest potential threat now and in the future. To demonstrate the screening tool, we present results for a representative sample of approximately 10% (n = 292) of Australia's known, naturalised alien plant species. Overall, most alien plant species showed decreases in area of habitat suitability under future conditions compared to current conditions and therefore the threat rating of most alien plant species declined between current and future conditions. Use of the screening tool is intended to assist natural resource managers in assessing the threat of alien plant establishment and spread under current and future conditions and thus prioritise detailed weed risk assessments for those species that pose the greatest threat. The screening tool is associated with a searchable database for all 292 alien plant species across a range of spatial scales, available through an interactive web-based portal at http://weedfutures.net/. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Knowledge about how species distributions shift through time increases basic ecological understanding, improves species management and conservation, and allows for enhanced predictions about the future. This type of research is difficult to conduct, especially for migratory wate...
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Lee, Dana N.; Papeş, Monica; Van Den Bussche, Ronald A.
2012-01-01
Success of the cattle industry in Latin America is impeded by the common vampire bat, Desmodus rotundus, through decreases in milk production and mass gain and increased risk of secondary infection and rabies. We used ecological niche modeling to predict the current potential distribution of D. rotundus and the future distribution of the species for the years 2030, 2050, and 2080 based on the A2, A1B, and B1 climate scenarios from the Intergovernmental Panel on Climate Change. We then combined the present day potential distribution with cattle density estimates to identify areas where cattle are at higher risk for the negative impacts due to D. rotundus. We evaluated our risk prediction by plotting 17 documented outbreaks of cattle rabies. Our results indicated highly suitable habitat for D. rotundus occurs throughout most of Mexico and Central America as well as portions of Venezuela, Guyana, the Brazilian highlands, western Ecuador, northern Argentina, and east of the Andes in Peru, Bolivia, and Paraguay. With future climate projections suitable habitat for D. rotundus is predicted in these same areas and additional areas in French Guyana, Suriname, Venezuela and Columbia; however D. rotundus are not likely to expand into the U.S. because of inadequate ‘temperature seasonality.’ Areas with large portions of cattle at risk include Mexico, Central America, Paraguay, and Brazil. Twelve of 17 documented cattle rabies outbreaks were represented in regions predicted at risk. Our present day and future predictions can help authorities focus rabies prevention efforts and inform cattle ranchers which areas are at an increased risk of cattle rabies because it has suitable habitat for D. rotundus. PMID:22900023
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Lee, Dana N; Papeş, Monica; Van den Bussche, Ronald A
2012-01-01
Success of the cattle industry in Latin America is impeded by the common vampire bat, Desmodus rotundus, through decreases in milk production and mass gain and increased risk of secondary infection and rabies. We used ecological niche modeling to predict the current potential distribution of D. rotundus and the future distribution of the species for the years 2030, 2050, and 2080 based on the A2, A1B, and B1 climate scenarios from the Intergovernmental Panel on Climate Change. We then combined the present day potential distribution with cattle density estimates to identify areas where cattle are at higher risk for the negative impacts due to D. rotundus. We evaluated our risk prediction by plotting 17 documented outbreaks of cattle rabies. Our results indicated highly suitable habitat for D. rotundus occurs throughout most of Mexico and Central America as well as portions of Venezuela, Guyana, the Brazilian highlands, western Ecuador, northern Argentina, and east of the Andes in Peru, Bolivia, and Paraguay. With future climate projections suitable habitat for D. rotundus is predicted in these same areas and additional areas in French Guyana, Suriname, Venezuela and Columbia; however D. rotundus are not likely to expand into the U.S. because of inadequate 'temperature seasonality.' Areas with large portions of cattle at risk include Mexico, Central America, Paraguay, and Brazil. Twelve of 17 documented cattle rabies outbreaks were represented in regions predicted at risk. Our present day and future predictions can help authorities focus rabies prevention efforts and inform cattle ranchers which areas are at an increased risk of cattle rabies because it has suitable habitat for D. rotundus.
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Remote-sensing based approach to forecast habitat quality under climate change scenarios.
Requena-Mullor, Juan M; López, Enrique; Castro, Antonio J; Alcaraz-Segura, Domingo; Castro, Hermelindo; Reyes, Andrés; Cabello, Javier
2017-01-01
As climate change is expected to have a significant impact on species distributions, there is an urgent challenge to provide reliable information to guide conservation biodiversity policies. In addressing this challenge, we propose a remote sensing-based approach to forecast the future habitat quality for European badger, a species not abundant and at risk of local extinction in the arid environments of southeastern Spain, by incorporating environmental variables related with the ecosystem functioning and correlated with climate and land use. Using ensemble prediction methods, we designed global spatial distribution models for the distribution range of badger using presence-only data and climate variables. Then, we constructed regional models for an arid region in the southeast Spain using EVI (Enhanced Vegetation Index) derived variables and weighting the pseudo-absences with the global model projections applied to this region. Finally, we forecast the badger potential spatial distribution in the time period 2071-2099 based on IPCC scenarios incorporating the uncertainty derived from the predicted values of EVI-derived variables. By including remotely sensed descriptors of the temporal dynamics and spatial patterns of ecosystem functioning into spatial distribution models, results suggest that future forecast is less favorable for European badgers than not including them. In addition, change in spatial pattern of habitat suitability may become higher than when forecasts are based just on climate variables. Since the validity of future forecast only based on climate variables is currently questioned, conservation policies supported by such information could have a biased vision and overestimate or underestimate the potential changes in species distribution derived from climate change. The incorporation of ecosystem functional attributes derived from remote sensing in the modeling of future forecast may contribute to the improvement of the detection of ecological responses under climate change scenarios.
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Remote-sensing based approach to forecast habitat quality under climate change scenarios
Requena-Mullor, Juan M.; López, Enrique; Castro, Antonio J.; Alcaraz-Segura, Domingo; Castro, Hermelindo; Reyes, Andrés; Cabello, Javier
2017-01-01
As climate change is expected to have a significant impact on species distributions, there is an urgent challenge to provide reliable information to guide conservation biodiversity policies. In addressing this challenge, we propose a remote sensing-based approach to forecast the future habitat quality for European badger, a species not abundant and at risk of local extinction in the arid environments of southeastern Spain, by incorporating environmental variables related with the ecosystem functioning and correlated with climate and land use. Using ensemble prediction methods, we designed global spatial distribution models for the distribution range of badger using presence-only data and climate variables. Then, we constructed regional models for an arid region in the southeast Spain using EVI (Enhanced Vegetation Index) derived variables and weighting the pseudo-absences with the global model projections applied to this region. Finally, we forecast the badger potential spatial distribution in the time period 2071–2099 based on IPCC scenarios incorporating the uncertainty derived from the predicted values of EVI-derived variables. By including remotely sensed descriptors of the temporal dynamics and spatial patterns of ecosystem functioning into spatial distribution models, results suggest that future forecast is less favorable for European badgers than not including them. In addition, change in spatial pattern of habitat suitability may become higher than when forecasts are based just on climate variables. Since the validity of future forecast only based on climate variables is currently questioned, conservation policies supported by such information could have a biased vision and overestimate or underestimate the potential changes in species distribution derived from climate change. The incorporation of ecosystem functional attributes derived from remote sensing in the modeling of future forecast may contribute to the improvement of the detection of ecological responses under climate change scenarios. PMID:28257501
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Potential distribution of pine wilt disease under future climate change scenarios
Nakamura, Katsunori; Nakao, Katsuhiro; Kominami, Yuji; Tanaka, Nobuyuki; Ohashi, Haruka; Takano, Kohei Takenaka; Takeuchi, Wataru; Matsui, Tetsuya
2017-01-01
Pine wilt disease (PWD) constitutes a serious threat to pine forests. Since development depends on temperature and drought, there is a concern that future climate change could lead to the spread of PWD infections. We evaluated the risk of PWD in 21 susceptible Pinus species on a global scale. The MB index, which represents the sum of the difference between the mean monthly temperature and 15 when the mean monthly temperatures exceeds 15°C, was used to determine current and future regions vulnerable to PWD (MB ≥ 22). For future climate conditions, we compared the difference in PWD risks among four different representative concentration pathways (RCPs 2.6, 4.5, 6.0, and 8.5) and two time periods (2050s and 2070s). We also evaluated the impact of climate change on habitat suitability for each Pinus species using species distribution models. The findings were then integrated and the potential risk of PWD spread under climate change was discussed. Within the natural Pinus distribution area, southern parts of North America, Europe, and Asia were categorized as vulnerable regions (MB ≥ 22; 16% of the total Pinus distribution area). Representative provinces in which PWD has been reported at least once overlapped with the vulnerable regions. All RCP scenarios showed expansion of vulnerable regions in northern parts of Europe, Asia, and North America under future climate conditions. By the 2070s, under RCP 8.5, an estimated increase in the area of vulnerable regions to approximately 50% of the total Pinus distribution area was revealed. In addition, the habitat conditions of a large portion of the Pinus distribution areas in Europe and Asia were deemed unsuitable by the 2070s under RCP 8.5. Approximately 40% of these regions overlapped with regions deemed vulnerable to PWD, suggesting that Pinus forests in these areas are at risk of serious damage due to habitat shifts and spread of PWD. PMID:28797067
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Potential distribution of pine wilt disease under future climate change scenarios.
Hirata, Akiko; Nakamura, Katsunori; Nakao, Katsuhiro; Kominami, Yuji; Tanaka, Nobuyuki; Ohashi, Haruka; Takano, Kohei Takenaka; Takeuchi, Wataru; Matsui, Tetsuya
2017-01-01
Pine wilt disease (PWD) constitutes a serious threat to pine forests. Since development depends on temperature and drought, there is a concern that future climate change could lead to the spread of PWD infections. We evaluated the risk of PWD in 21 susceptible Pinus species on a global scale. The MB index, which represents the sum of the difference between the mean monthly temperature and 15 when the mean monthly temperatures exceeds 15°C, was used to determine current and future regions vulnerable to PWD (MB ≥ 22). For future climate conditions, we compared the difference in PWD risks among four different representative concentration pathways (RCPs 2.6, 4.5, 6.0, and 8.5) and two time periods (2050s and 2070s). We also evaluated the impact of climate change on habitat suitability for each Pinus species using species distribution models. The findings were then integrated and the potential risk of PWD spread under climate change was discussed. Within the natural Pinus distribution area, southern parts of North America, Europe, and Asia were categorized as vulnerable regions (MB ≥ 22; 16% of the total Pinus distribution area). Representative provinces in which PWD has been reported at least once overlapped with the vulnerable regions. All RCP scenarios showed expansion of vulnerable regions in northern parts of Europe, Asia, and North America under future climate conditions. By the 2070s, under RCP 8.5, an estimated increase in the area of vulnerable regions to approximately 50% of the total Pinus distribution area was revealed. In addition, the habitat conditions of a large portion of the Pinus distribution areas in Europe and Asia were deemed unsuitable by the 2070s under RCP 8.5. Approximately 40% of these regions overlapped with regions deemed vulnerable to PWD, suggesting that Pinus forests in these areas are at risk of serious damage due to habitat shifts and spread of PWD.
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NASA Astrophysics Data System (ADS)
Gulyás, Krisztina; Berki, Imre; Veperdi, Gábor
2017-04-01
As a result of regional climate change, most European countries are experiencing an increase in mean annual temperature and CO2 concentration and a decrease in mean annual precipitation. In low-elevation areas in Southeast Europe, where precipitation is a limiting factor, the projected climate change threatens the health, production, and potential distribution of forest ecosystems. The intensive summer droughts and commonly occurring extreme weather events create negative influences that cause health declines, changes in yield potential, and tree mortality. Due to the observed damages, attention has been focused on these problems. The impacts of climatic extremes cause difficulties in forest management; these difficulties occur more frequently in Hungary, which is a region that is the most sensitive to climatic extremes. Regional climate model simulations project that the frequency of extremely high temperatures and long-term dry periods will increase; both of these factors have negative effects on future tree species distribution and production. Thus, the aim of our study is to utilize the sessile oak (Quercus petraea) as a climate indicator tree species to investigate potential future distribution and estimate changes in growth trends. For future spatial distribution, we used the Fuzzy membership distribution model in a new Decision Support System (DSS) which was developed for the Hungarian forestry and agricultural sectors. Through study techniques we can employ DSS, which contains various environmental layers (topography, vegetation, past and projected future climate, soils, and hydrology), to create probability distribution maps. The results, based on 12 regional climate model simulations (www.ensembles-eu.org), show that the area of sessile oak forests is shrinking continuously and will continue to do so to the end of the 21st century. For future production estimations, we analysed intensive long-term growth monitoring network plots that were established in 1993. We calculated production capacity on the basis of age and height; we then compared these to past climate conditions to discover connections between climate, site conditions, and production. We estimated future growth tendencies for three different time periods (2011-2040; 2041-2070; 2071-2100). Results show that the most vulnerable region is the south-western part of Hungary where the projected production capacity may decrease by 26% for the time period 2071-2100. The impacts of climate change may be milder in the north-eastern part of Hungary where a 19% decrease in the production capacity of sessile oak forests is estimated. These investigations and results are important for sustainable forest management and help define climate change adaptation strategies in forestry. Keywords: climate change impacts, distribution modelling, production capacity Acknowledgements: Research is supported by the ÚNKP-16-3-3 New National Excellence Program of the Ministry of Human Capacities and the "Agroclimate.2" (VKSZ_12-1-2013-0034) EU-national joint funded research project.
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NASA Astrophysics Data System (ADS)
Jamróz, M. H.; Dobrowolski, J. Cz.
2001-05-01
For the most stable Li, Na, and Cu(I) diformates we present the vibrational spectra, supported by potential energy distribution (PED) analysis, and the interaction energies between formic acid and metal formate by the DFT (B3PW91) method. PED analysis of the theoretical spectra forms the basis for the elucidation of the future matrix isolation IR spectra.
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Impacts of Climate Change on Native Landcover: Seeking Future Climatic Refuges
Mangabeira Albernaz, Ana Luisa
2016-01-01
Climate change is a driver for diverse impacts on global biodiversity. We investigated its impacts on native landcover distribution in South America, seeking to predict its effect as a new force driving habitat loss and population isolation. Moreover, we mapped potential future climatic refuges, which are likely to be key areas for biodiversity conservation under climate change scenarios. Climatically similar native landcovers were aggregated using a decision tree, generating a reclassified landcover map, from which 25% of the map’s coverage was randomly selected to fuel distribution models. We selected the best geographical distribution models among twelve techniques, validating the predicted distribution for current climate with the landcover map and used the best technique to predict the future distribution. All landcover categories showed changes in area and displacement of the latitudinal/longitudinal centroid. Closed vegetation was the only landcover type predicted to expand its distributional range. The range contractions predicted for other categories were intense, even suggesting extirpation of the sparse vegetation category. The landcover refuges under future climate change represent a small proportion of the South American area and they are disproportionately represented and unevenly distributed, predominantly occupying five of 26 South American countries. The predicted changes, regardless of their direction and intensity, can put biodiversity at risk because they are expected to occur in the near future in terms of the temporal scales of ecological and evolutionary processes. Recognition of the threat of climate change allows more efficient conservation actions. PMID:27618445
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Impacts of Climate Change on Native Landcover: Seeking Future Climatic Refuges.
Zanin, Marina; Mangabeira Albernaz, Ana Luisa
2016-01-01
Climate change is a driver for diverse impacts on global biodiversity. We investigated its impacts on native landcover distribution in South America, seeking to predict its effect as a new force driving habitat loss and population isolation. Moreover, we mapped potential future climatic refuges, which are likely to be key areas for biodiversity conservation under climate change scenarios. Climatically similar native landcovers were aggregated using a decision tree, generating a reclassified landcover map, from which 25% of the map's coverage was randomly selected to fuel distribution models. We selected the best geographical distribution models among twelve techniques, validating the predicted distribution for current climate with the landcover map and used the best technique to predict the future distribution. All landcover categories showed changes in area and displacement of the latitudinal/longitudinal centroid. Closed vegetation was the only landcover type predicted to expand its distributional range. The range contractions predicted for other categories were intense, even suggesting extirpation of the sparse vegetation category. The landcover refuges under future climate change represent a small proportion of the South American area and they are disproportionately represented and unevenly distributed, predominantly occupying five of 26 South American countries. The predicted changes, regardless of their direction and intensity, can put biodiversity at risk because they are expected to occur in the near future in terms of the temporal scales of ecological and evolutionary processes. Recognition of the threat of climate change allows more efficient conservation actions.
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Martinez, Pablo Ariel; Andrade, Mayane Alves; Bidau, Claudio Juan
2018-06-01
The temporal pattern of co-occurrence of human beings and venomous species (scorpions, spiders, snakes) is changing. Thus, the temporal pattern of areas with risk of accidents with such species tends to become dynamic in time. We analyze the areas of occurrence of species of Tityus in Argentina and assess the impact of global climate change on their area of distribution by the construction of risk maps. Using data of occurrence of the species and climatic variables, we constructed models of species distribution (SMDs) under current and future climatic conditions. We also created maps that allow the detection of temporal shifts in the distribution patterns of each Tityus species. Finally, we developed risk maps for the analyzed species. Our results predict that climate change will have an impact on the distribution of Tityus species which will clearly expand to more southern latitudes, with the exception of T. argentinus. T. bahiensis, widely distributed in Brazil, showed a considerable increase of its potential area (ca. 37%) with future climate change. The species T. confluens and T. trivittatus that cause the highest number of accidents in Argentina are expected to show significant changes of their distributions in future scenarios. The former fact is worrying because Buenos Aires province is the more densely populated district in Argentina thus iable to become the most affected by T. trivittatus. These alterations of distributional patterns can lead to amplify the accident risk zones of venomous species, becoming an important subject of concern for public health policies. Copyright © 2018 Elsevier Ltd. All rights reserved.
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García-Vázquez, Uri; D’Addario, Maristella
2018-01-01
Land use and climate change are affecting the abundance and distribution of species. The Trans-Mexican Volcanic Belt (TMVB) is a very diverse region due to geological history, geographic position, and climate. It is also one of the most disturbed regions in Mexico. Reptiles are particularly sensitive to environmental changes due to their low dispersal capacity and thermal ecology. In this study, we define the important environmental variables (considering climate, topography, and land use) and potential distribution (present and future) of the five Thamnophis species present in TMVB. To do so, we used the maximum entropy modeling software (MAXENT). First, we modeled to select the most important variables to explain the distribution of each species, then we modeled again using only the most important variables and projected these models to the future considering a middle-moderate climate change scenario (rcp45), and land use and vegetation variables for the year 2050 (generated according to land use changes that occurred between years 2002 and 2011). Arid vegetation had an important negative effect on habitat suitability for all species, and minimum temperature of the coldest month was important for four of the five species. Thamnophis cyrtopsis was the species with the lowest tolerance to minimum temperatures. The maximum temperature of the warmest month was important for T. scalaris and T. cyrtopsis. Low percentages of agriculture were positive for T. eques and T. melanogaster but, at higher values, agriculture had a negative effect on habitat suitability for both species. Elevation was the most important variable to explain T. eques and T. melanogaster potential distribution while distance to Abies forests was the most important variable for T. scalaris and T. scaliger. All species had a high proportion of their potential distribution in the TMVB. However, according to our models, all Thamnophis species will experience reductions in their potential distribution in this region. T. scalaris will suffer the biggest reduction because this species is limited by high temperatures and will not be able to shift its distribution upward, as it is already present in the highest elevations of the TMVB. PMID:29666767
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Fourcade, Yoan; Ranius, Thomas; Öckinger, Erik
2017-10-01
Prediction of species distributions in an altered climate requires knowledge on how global- and local-scale factors interact to limit their current distributions. Such knowledge can be gained through studies of spatial population dynamics at climatic range margins. Here, using a butterfly (Pyrgus armoricanus) as model species, we first predicted based on species distribution modelling that its climatically suitable habitats currently extend north of its realized range. Projecting the model into scenarios of future climate, we showed that the distribution of climatically suitable habitats may shift northward by an additional 400 km in the future. Second, we used a 13-year monitoring dataset including the majority of all habitat patches at the species northern range margin to assess the synergetic impact of temperature fluctuations and spatial distribution of habitat, microclimatic conditions and habitat quality, on abundance and colonization-extinction dynamics. The fluctuation in abundance between years was almost entirely determined by the variation in temperature during the species larval development. In contrast, colonization and extinction dynamics were better explained by patch area, between-patch connectivity and host plant density. This suggests that the response of the species to future climate change may be limited by future land use and how its host plants respond to climate change. It is, thus, probable that dispersal limitation will prevent P. armoricanus from reaching its potential future distribution. We argue that models of range dynamics should consider the factors influencing metapopulation dynamics, especially at the range edges, and not only broad-scale climate. It includes factors acting at the scale of habitat patches such as habitat quality and microclimate and landscape-scale factors such as the spatial configuration of potentially suitable patches. Knowledge of population dynamics under various environmental conditions, and the incorporation of realistic scenarios of future land use, appears essential to provide predictions useful for actions mitigating the negative effects of climate change. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.
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Carbajo, Aníbal E; Vera, Carolina; González, Paula LM
2009-01-01
Background Oligoryzomys longicaudatus (colilargo) is the rodent responsible for hantavirus pulmonary syndrome (HPS) in Argentine Patagonia. In past decades (1967–1998), trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends. Methods Four scenarios of potential climate change were constructed using temperature and precipitation changes observed in Argentine Patagonia between 1967 and 1998: Scenario 1 assumed no change in precipitation but a temperature trend as observed; scenario 2 assumed no changes in temperature but a precipitation trend as observed; Scenario 3 included changes in both temperature and precipitation trends as observed; Scenario 4 assumed changes in both temperature and precipitation trends as observed but doubled. We used a validated spatial distribution model of O. longicaudatus as a function of temperature and precipitation. From the model probability of the rodent presence was calculated for each scenario. Results If changes in precipitation follow previous trends, the probability of the colilargo presence would fall in the HPS transmission zone of northern Patagonia. If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards. These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir. Conclusion According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent distribution in an equivalent period of time only in certain areas. Given that changes maintain for 60 years or double in 30 years, the hantavirus reservoir Oligoryzomys longicaudatus may contract its distribution in Argentine Patagonia extensively. PMID:19607707
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Shabani, Farzin; Kumar, Lalit; Nojoumian, Amir Hadi; Esmaeili, Atefeh; Toghyani, Mehdi
2016-03-15
Micronutrient deficiency develops when nutrient intake does not match nutritional requirements for maintaining healthy tissue and organ functions which may have long-ranging effects on health, learning ability and productivity. Inadequacy of iron, zinc and vitamin A are the most important micronutrient deficiencies. Consumption of a 100 g portion of date flesh from date palm (Phoenix dactylifera L.) has been reported to meet approximately half the daily dietary recommended intake of these micronutrients. This study investigated the potential distribution of P. dactylifera under future climates to address its potential long-term use as a food commodity to tackle micronutrient deficiencies in some developing countries. Modelling outputs indicated large shifts in areas conducive to date palm cultivation, based on global-scale alteration over the next 60 years. Most of the regions suffering from micronutrient deficiencies were projected to become highly conducive for date palm cultivation. These results could inform strategic planning by government and agricultural organizations by identifying areas to cultivate this nutritionally important crop in the future to support the alleviation of micronutrient deficiencies. © 2015 Society of Chemical Industry.
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Analyzing the responses of species assemblages to climate change across the Great Basin, USA.
NASA Astrophysics Data System (ADS)
Henareh Khalyani, A.; Falkowski, M. J.; Crookston, N.; Yousef, F.
2016-12-01
The potential impacts of climate change on the future distribution of tree species in not well understood. Climate driven changes in tree species distribution could cause significant changes in realized species niches, potentially resulting in the loss of ecotonal species as well as the formation on novel assemblages of overlapping tree species. In an effort to gain a better understating of how the geographic distribution of tree species may respond to climate change, we model the potential future distribution of 50 different tree species across 70 million ha in the Great Basin, USA. This is achieved by leveraging a species realized niche model based on non-parametric analysis of species occurrences across climatic, topographic, and edaphic variables. Spatially explicit, high spatial resolution (30 m) climate variables (e.g., precipitation, and minimum, maximum, and mean temperature) and associated climate indices were generated on an annual basis between 1981-2010 by integrating climate station data with digital elevation data (Shuttle Radar Topographic Mission (SRTM) data) in a thin plate spline interpolation algorithm (ANUSPLIN). Bioclimate models of species niches in in the cotemporary period and three following 30 year periods were then generated by integrating the climate variables, soil data, and CMIP 5 general circulation model projections. Our results suggest that local scale contemporary variations in species realized niches across space are influenced by edaphic and topographic variables as well as climatic variables. The local variability in soil properties and topographic variability across space also affect the species responses to climate change through time and potential formation of species assemblages in future. The results presented here in will aid in the development of adaptive forest management techniques aimed at mitigating negative impacts of climate change on forest composition, structure, and function.
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Nazeri, Mona; Jusoff, Kamaruzaman; Madani, Nima; Mahmud, Ahmad Rodzi; Bahman, Abdul Rani; Kumar, Lalit
2012-01-01
One of the available tools for mapping the geographical distribution and potential suitable habitats is species distribution models. These techniques are very helpful for finding poorly known distributions of species in poorly sampled areas, such as the tropics. Maximum Entropy (MaxEnt) is a recently developed modeling method that can be successfully calibrated using a relatively small number of records. In this research, the MaxEnt model was applied to describe the distribution and identify the key factors shaping the potential distribution of the vulnerable Malayan Sun Bear (Helarctos malayanus) in one of the main remaining habitats in Peninsular Malaysia. MaxEnt results showed that even though Malaysian sun bear habitat is tied with tropical evergreen forests, it lives in a marginal threshold of bio-climatic variables. On the other hand, current protected area networks within Peninsular Malaysia do not cover most of the sun bears potential suitable habitats. Assuming that the predicted suitability map covers sun bears actual distribution, future climate change, forest degradation and illegal hunting could potentially severely affect the sun bear's population.
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Nazeri, Mona; Jusoff, Kamaruzaman; Madani, Nima; Mahmud, Ahmad Rodzi; Bahman, Abdul Rani; Kumar, Lalit
2012-01-01
One of the available tools for mapping the geographical distribution and potential suitable habitats is species distribution models. These techniques are very helpful for finding poorly known distributions of species in poorly sampled areas, such as the tropics. Maximum Entropy (MaxEnt) is a recently developed modeling method that can be successfully calibrated using a relatively small number of records. In this research, the MaxEnt model was applied to describe the distribution and identify the key factors shaping the potential distribution of the vulnerable Malayan Sun Bear (Helarctos malayanus) in one of the main remaining habitats in Peninsular Malaysia. MaxEnt results showed that even though Malaysian sun bear habitat is tied with tropical evergreen forests, it lives in a marginal threshold of bio-climatic variables. On the other hand, current protected area networks within Peninsular Malaysia do not cover most of the sun bears potential suitable habitats. Assuming that the predicted suitability map covers sun bears actual distribution, future climate change, forest degradation and illegal hunting could potentially severely affect the sun bear’s population. PMID:23110182
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Meier, E.S.; Edwards, T.C.; Kienast, Felix; Dobbertin, M.; Zimmermann, N.E.
2011-01-01
Aim During recent and future climate change, shifts in large-scale species ranges are expected due to the hypothesized major role of climatic factors in regulating species distributions. The stress-gradient hypothesis suggests that biotic interactions may act as major constraints on species distributions under more favourable growing conditions, while climatic constraints may dominate under unfavourable conditions. We tested this hypothesis for one focal tree species having three major competitors using broad-scale environmental data. We evaluated the variation of species co-occurrence patterns in climate space and estimated the influence of these patterns on the distribution of the focal species for current and projected future climates.Location Europe.Methods We used ICP Forest Level 1 data as well as climatic, topographic and edaphic variables. First, correlations between the relative abundance of European beech (Fagus sylvatica) and three major competitor species (Picea abies, Pinus sylvestris and Quercus robur) were analysed in environmental space, and then projected to geographic space. Second, a sensitivity analysis was performed using generalized additive models (GAM) to evaluate where and how much the predicted F. sylvatica distribution varied under current and future climates if potential competitor species were included or excluded. We evaluated if these areas coincide with current species co-occurrence patterns.Results Correlation analyses supported the stress-gradient hypothesis: towards favourable growing conditions of F. sylvatica, its abundance was strongly linked to the abundance of its competitors, while this link weakened towards unfavourable growing conditions, with stronger correlations in the south and at low elevations than in the north and at high elevations. The sensitivity analysis showed a potential spatial segregation of species with changing climate and a pronounced shift of zones where co-occurrence patterns may play a major role.Main conclusions Our results demonstrate the importance of species co-occurrence patterns for calibrating improved species distribution models for use in projections of climate effects. The correlation approach is able to localize European areas where inclusion of biotic predictors is effective. The climate-induced spatial segregation of the major tree species could have ecological and economic consequences. ?? 2010 Blackwell Publishing Ltd.
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Wakie, Tewodros; Evangelista, Paul H.; Jarnevich, Catherine S.; Laituri, Melinda
2014-01-01
We used correlative models with species occurrence points, Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices, and topo-climatic predictors to map the current distribution and potential habitat of invasive Prosopis juliflora in Afar, Ethiopia. Time-series of MODIS Enhanced Vegetation Indices (EVI) and Normalized Difference Vegetation Indices (NDVI) with 250 m2 spatial resolution were selected as remote sensing predictors for mapping distributions, while WorldClim bioclimatic products and generated topographic variables from the Shuttle Radar Topography Mission product (SRTM) were used to predict potential infestations. We ran Maxent models using non-correlated variables and the 143 species-occurrence points. Maxent generated probability surfaces were converted into binary maps using the 10-percentile logistic threshold values. Performances of models were evaluated using area under the receiver-operating characteristic (ROC) curve (AUC). Our results indicate that the extent of P. juliflora invasion is approximately 3,605 km2 in the Afar region (AUC = 0.94), while the potential habitat for future infestations is 5,024 km2 (AUC = 0.95). Our analyses demonstrate that time-series of MODIS vegetation indices and species occurrence points can be used with Maxent modeling software to map the current distribution of P. juliflora, while topo-climatic variables are good predictors of potential habitat in Ethiopia. Our results can quantify current and future infestations, and inform management and policy decisions for containing P. juliflora. Our methods can also be replicated for managing invasive species in other East African countries.
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Benchmarking U.S. Small Wind Costs with the Distributed Wind Taxonomy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Orrell, Alice C.; Poehlman, Eric A.
The objective of this report is to benchmark costs for small wind projects installed in the United States using a distributed wind taxonomy. Consequently, this report is a starting point to help expand the U.S. distributed wind market by informing potential areas for small wind cost-reduction opportunities and providing a benchmark to track future small wind cost-reduction progress.
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Bringing modeling to the masses: A web based system to predict potential species distributions
Graham, Jim; Newman, Greg; Kumar, Sunil; Jarnevich, Catherine S.; Young, Nick; Crall, Alycia W.; Stohlgren, Thomas J.; Evangelista, Paul
2010-01-01
Predicting current and potential species distributions and abundance is critical for managing invasive species, preserving threatened and endangered species, and conserving native species and habitats. Accurate predictive models are needed at local, regional, and national scales to guide field surveys, improve monitoring, and set priorities for conservation and restoration. Modeling capabilities, however, are often limited by access to software and environmental data required for predictions. To address these needs, we built a comprehensive web-based system that: (1) maintains a large database of field data; (2) provides access to field data and a wealth of environmental data; (3) accesses values in rasters representing environmental characteristics; (4) runs statistical spatial models; and (5) creates maps that predict the potential species distribution. The system is available online at www.niiss.org, and provides web-based tools for stakeholders to create potential species distribution models and maps under current and future climate scenarios.
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Areas of high conservation value at risk by plant invaders in Georgia under climate change.
Slodowicz, Daniel; Descombes, Patrice; Kikodze, David; Broennimann, Olivier; Müller-Schärer, Heinz
2018-05-01
Invasive alien plants (IAP) are a threat to biodiversity worldwide. Understanding and anticipating invasions allow for more efficient management. In this regard, predicting potential invasion risks by IAPs is essential to support conservation planning into areas of high conservation value (AHCV) such as sites exhibiting exceptional botanical richness, assemblage of rare, and threatened and/or endemic plant species. Here, we identified AHCV in Georgia, a country showing high plant richness, and assessed the susceptibility of these areas to colonization by IAPs under present and future climatic conditions. We used actual protected areas and areas of high plant endemism (identified using occurrences of 114 Georgian endemic plant species) as proxies for AHCV. Then, we assessed present and future potential distribution of 27 IAPs using species distribution models under four climate change scenarios and stacked single-species potential distribution into a consensus map representing IAPs richness. We evaluated present and future invasion risks in AHCV using IAPs richness as a metric of susceptibility. We show that the actual protected areas cover only 9.4% of the areas of high plant endemism in Georgia. IAPs are presently located at lower elevations around the large urban centers and in western Georgia. We predict a shift of IAPs toward eastern Georgia and higher altitudes and an increased susceptibility of AHCV to IAPs under future climate change. Our study provides a good baseline for decision makers and stakeholders on where and how resources should be invested in the most efficient way to protect Georgia's high plant richness from IAPs.
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The Role of X-Rays in Future Space Navigation and Communication
NASA Technical Reports Server (NTRS)
Winternitz, Luke M. B.; Gendreau, Keith C.; Hasouneh, Monther A.; Mitchell, Jason W.; Fong, Wai H.; Lee, Wing-Tsz; Gavriil, Fotis; Arzoumanian, Zaven
2013-01-01
In the near future, applications using X-rays will enable autonomous navigation and time distribution throughout the solar system, high capacity and low-power space data links, highly accurate attitude sensing, and extremely high-precision formation flying capabilities. Each of these applications alone has the potential to revolutionize mission capabilities, particularly beyond Earth orbit. This paper will outline the NASA Goddard Space Flight Center vision and efforts toward realizing the full potential of X-ray navigation and communications.
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Climate-Induced Range Shifts and Possible Hybridisation Consequences in Insects
Sánchez-Guillén, Rosa Ana; Muñoz, Jesús; Rodríguez-Tapia, Gerardo; Feria Arroyo, T. Patricia; Córdoba-Aguilar, Alex
2013-01-01
Many ectotherms have altered their geographic ranges in response to rising global temperatures. Current range shifts will likely increase the sympatry and hybridisation between recently diverged species. Here we predict future sympatric distributions and risk of hybridisation in seven Mediterranean ischnurid damselfly species (I. elegans, I. fountaineae, I. genei, I. graellsii, I. pumilio, I. saharensis and I. senegalensis). We used a maximum entropy modelling technique to predict future potential distribution under four different Global Circulation Models and a realistic emissions scenario of climate change. We carried out a comprehensive data compilation of reproductive isolation (habitat, temporal, sexual, mechanical and gametic) between the seven studied species. Combining the potential distribution and data of reproductive isolation at different instances (habitat, temporal, sexual, mechanical and gametic), we infer the risk of hybridisation in these insects. Our findings showed that all but I. graellsii will decrease in distributional extent and all species except I. senegalensis are predicted to have northern range shifts. Models of potential distribution predicted an increase of the likely overlapping ranges for 12 species combinations, out of a total of 42 combinations, 10 of which currently overlap. Moreover, the lack of complete reproductive isolation and the patterns of hybridisation detected between closely related ischnurids, could lead to local extinctions of native species if the hybrids or the introgressed colonising species become more successful. PMID:24260411
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Kaky, Emad; Gilbert, Francis
2017-01-01
Climate change is one of the most difficult of challenges to conserving biodiversity, especially for countries with few data on the distributions of their taxa. Species distribution modelling is a modern approach to the assessment of the potential effects of climate change on biodiversity, with the great advantage of being robust to small amounts of data. Taking advantage of a recently validated dataset, we use the medicinal plants of Egypt to identify hotspots of diversity now and in the future by predicting the effect of climate change on the pattern of species richness using species distribution modelling. Then we assess how Egypt's current Protected Area network is likely to perform in protecting plants under climate change. The patterns of species richness show that in most cases the A2a 'business as usual' scenario was more harmful than the B2a 'moderate mitigation' scenario. Predicted species richness inside Protected Areas was higher than outside under all scenarios, indicating that Egypt's PAs are well placed to help conserve medicinal plants.
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Land Cover and Climate Change May Limit Invasiveness of Rhododendron ponticum in Wales.
Manzoor, Syed A; Griffiths, Geoffrey; Iizuka, Kotaro; Lukac, Martin
2018-01-01
Invasive plant species represent a serious threat to biodiversity precipitating a sustained global effort to eradicate or at least control the spread of this phenomenon. Current distribution ranges of many invasive species are likely to be modified in the future by land cover and climate change. Thus, invasion management can be made more effective by forecasting the potential spread of invasive species. Rhododendron ponticum (L.) is an aggressive invasive species which appears well suited to western areas of the UK. We made use of MAXENT modeling environment to develop a current distribution model and to assess the likely effects of land cover and climatic conditions (LCCs) on the future distribution of this species in the Snowdonia National park in Wales. Six global circulation models (GCMs) and two representative concentration pathways (RCPs), together with a land cover simulation for 2050 were used to investigate species' response to future environmental conditions. Having considered a range of environmental variables as predictors and carried out the AICc-based model selection, we find that under all LCCs considered in this study, the range of R. ponticum in Wales is likely to contract in the future. Land cover and topographic variables were found to be the most important predictors of the distribution of R. ponticum . This information, together with maps indicating future distribution trends will aid the development of mitigation practices to control R. ponticum .
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Suwannatrai, A; Pratumchart, K; Suwannatrai, K; Thinkhamrop, K; Chaiyos, J; Kim, C S; Suwanweerakamtorn, R; Boonmars, T; Wongsaroj, T; Sripa, B
2017-01-01
Global climate change is now regarded as imposing a significant threat of enhancing transmission of parasitic diseases. Maximum entropy species distribution modeling (MaxEnt) was used to explore how projected climate change could affect the potential distribution of the carcinogenic liver fluke, Opisthorchis viverrini, in Thailand. A range of climate variables was used: the Hadley Global Environment Model 2-Earth System (HadGEM2-ES) climate change model and also the IPCC scenarios A2a for 2050 and 2070. Occurrence data from surveys conducted in 2009 and 2014 were obtained from the Department of Disease Control, Ministry of Public Health, Thailand. The MaxEnt model performed better than random for O. viverrini with training AUC values greater than 0.8 under current and future climatic conditions. The current distribution of O. viverrini is significantly affected by precipitation and minimum temperature. According to current conditions, parts of Thailand climatically suitable for O. viverrini are mostly in the northeast and north, but the parasite is largely absent from southern Thailand. Under future climate change scenarios, the distribution of O. viverrini in 2050 should be significantly affected by precipitation, maximum temperature, and mean temperature of the wettest quarter, whereas in 2070, significant factors are likely to be precipitation during the coldest quarter, maximum, and minimum temperatures. Maps of predicted future distribution revealed a drastic decrease in presence of O. viverrini in the northeast region. The information gained from this study should be a useful reference for implementing long-term prevention and control strategies for O. viverrini in Thailand.
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Porfirio, Luciana L.; Harris, Rebecca M. B.; Lefroy, Edward C.; Hugh, Sonia; Gould, Susan F.; Lee, Greg; Bindoff, Nathaniel L.; Mackey, Brendan
2014-01-01
Choice of variables, climate models and emissions scenarios all influence the results of species distribution models under future climatic conditions. However, an overview of applied studies suggests that the uncertainty associated with these factors is not always appropriately incorporated or even considered. We examine the effects of choice of variables, climate models and emissions scenarios can have on future species distribution models using two endangered species: one a short-lived invertebrate species (Ptunarra Brown Butterfly), and the other a long-lived paleo-endemic tree species (King Billy Pine). We show the range in projected distributions that result from different variable selection, climate models and emissions scenarios. The extent to which results are affected by these choices depends on the characteristics of the species modelled, but they all have the potential to substantially alter conclusions about the impacts of climate change. We discuss implications for conservation planning and management, and provide recommendations to conservation practitioners on variable selection and accommodating uncertainty when using future climate projections in species distribution models. PMID:25420020
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Lin, Li; Jin, Ling; Wang, Zhen-Heng; Cui, Zhi-Jia; Ma, Yi
2017-07-01
To predict the suitable distribution patterns of Lycium ruthenicum in the present and future under the background of climate change, and provide reference for the resources sustainable utilization and GAP standardized planting. The software of Maxent and ArcGis was used to predict the potential suitable regions and grades of L. ruthenicum in China based on the 149 distribution information, climate data of contemporary (1950-2000) and future (20-80 decade of 21 century), and considering of three greenhouse gaseous emission scenario. The results showed that：the suitable distribution regions of L. ruthenicum are mainly concentrated in Xinjiang, Qinghai, Gansu, Neimenggu, and Ningxia province in present. In addition, Shaanxi, Shanxi and Xizang are also distribution regions.The suitable distribution area of L. ruthenicum is 284.506 949×104 km2, accounted for 29.6% of the land area of China.The relatively stable area of the suitable regions accounted for 25.2% of the total suitable region area.Under the background of climate change, compared with contemporary, the total area of suitable region is reducing and moderately suitable area is increasing at different degree at the 20, 30, 40, 50, 60, 70, 80 decade of 21 century. Climate change both can change the total area of suitable regions and habitat suitability of L. ruthenicum. It could provide a strategic guidance for protection, development and utilization of L. ruthenicum though the prediction of potential suitable regions distribution of L. ruthenicum based on the mainly factor of climate change. Copyright© by the Chinese Pharmaceutical Association.
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Komac, Benjamin; Esteban, Pere; Trapero, Laura; Caritg, Roger
2016-01-01
Mountain areas are particularly sensitive to climate change. Species distribution models predict important extinctions in these areas whose magnitude will depend on a number of different factors. Here we examine the possible impact of climate change on the Rhododendron ferrugineum (alpenrose) niche in Andorra (Pyrenees). This species currently occupies 14.6 km2 of this country and relies on the protection afforded by snow cover in winter. We used high-resolution climatic data, potential snow accumulation and a combined forecasting method to obtain the realized niche model of this species. Subsequently, we used data from the high-resolution Scampei project climate change projection for the A2, A1B and B1 scenarios to model its future realized niche model. The modelization performed well when predicting the species’s distribution, which improved when we considered the potential snow accumulation, the most important variable influencing its distribution. We thus obtained a potential extent of about 70.7 km2 or 15.1% of the country. We observed an elevation lag distribution between the current and potential distribution of the species, probably due to its slow colonization rate and the small-scale survey of seedlings. Under the three climatic scenarios, the realized niche model of the species will be reduced by 37.9–70.1 km2 by the end of the century and it will become confined to what are today screes and rocky hillside habitats. The particular effects of climate change on seedling establishment, as well as on the species’ plasticity and sensitivity in the event of a reduction of the snow cover, could worsen these predictions. PMID:26824847
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Maguire, Kaitlin C; Shinneman, Douglas J; Potter, Kevin M; Hipkins, Valerie D
2018-03-14
Unique responses to climate change can occur across intraspecific levels, resulting in individualistic adaptation or movement patterns among populations within a given species. Thus, the need to model potential responses among genetically distinct populations within a species is increasingly recognized. However, predictive models of future distributions are regularly fit at the species level, often because intraspecific variation is unknown or is identified only within limited sample locations. In this study, we considered the role of intraspecific variation to shape the geographic distribution of ponderosa pine (Pinus ponderosa), an ecologically and economically important tree species in North America. Morphological and genetic variation across the distribution of ponderosa pine suggest the need to model intraspecific populations: the two varieties (var. ponderosa and var. scopulorum) and several haplotype groups within each variety have been shown to occupy unique climatic niches, suggesting populations have distinct evolutionary lineages adapted to different environmental conditions. We utilized a recently-available, geographically-widespread dataset of intraspecific variation (haplotypes) for ponderosa pine and a recently-devised lineage distance modeling approach to derive additional, likely intraspecific occurrence locations. We confirmed the relative uniqueness of each haplotype-climate relationship using a niche-overlap analysis, and developed ecological niche models (ENMs) to project the distribution for two varieties and eight haplotypes under future climate forecasts. Future projections of haplotype niche distributions generally revealed greater potential range loss than predicted for the varieties. This difference may reflect intraspecific responses of distinct evolutionary lineages. However, directional trends are generally consistent across intraspecific levels, and include a loss of distributional area and an upward shift in elevation. Our results demonstrate the utility in modeling intraspecific response to changing climate and they inform management and conservation strategies, by identifying haplotypes and geographic areas that may be most at risk, or most secure, under projected climate change.
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Maguire, Kaitlin C.; Shinneman, Douglas; Potter, Kevin M.; Hipkins, Valerie D.
2018-01-01
Unique responses to climate change can occur across intraspecific levels, resulting in individualistic adaptation or movement patterns among populations within a given species. Thus, the need to model potential responses among genetically distinct populations within a species is increasingly recognized. However, predictive models of future distributions are regularly fit at the species level, often because intraspecific variation is unknown or is identified only within limited sample locations. In this study, we considered the role of intraspecific variation to shape the geographic distribution of ponderosa pine (Pinus ponderosa), an ecologically and economically important tree species in North America. Morphological and genetic variation across the distribution of ponderosa pine suggest the need to model intraspecific populations: the two varieties (var. ponderosa and var. scopulorum) and several haplotype groups within each variety have been shown to occupy unique climatic niches, suggesting populations have distinct evolutionary lineages adapted to different environmental conditions. We utilized a recently-available, geographically-widespread dataset of intraspecific variation (haplotypes) for ponderosa pine and a recently-devised lineage distance modeling approach to derive additional, likely intraspecific occurrence locations. We confirmed the relative uniqueness of each haplotype-climate relationship using a niche-overlap analysis, and developed ecological niche models (ENMs) to project the distribution for two varieties and eight haplotypes under future climate forecasts. Future projections of haplotype niche distributions generally revealed greater potential range loss than predicted for the varieties. This difference may reflect intraspecific responses of distinct evolutionary lineages. However, directional trends are generally consistent across intraspecific levels, and include a loss of distributional area and an upward shift in elevation. Our results demonstrate the utility in modeling intraspecific response to changing climate and they inform management and conservation strategies, by identifying haplotypes and geographic areas that may be most at risk, or most secure, under projected climate change.
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NASA Astrophysics Data System (ADS)
Rombouts, Isabelle; Beaugrand, Grégory; Dauvin, Jean-Claude
2012-03-01
Climate-induced changes in the distribution of species are likely to affect the functioning and diversity of marine ecosystems. Therefore, in economic and ecological important areas, such as the English Channel, projections of the future distributions of key species under changing environmental conditions are urgently needed. Ecological Niche Models (ENMs) have been applied successfully to determine potential distributions of species based on the information of the environmental niche of a species (sensu Hutchinson). In this study, the niches of two commercially exploited benthic species, Pecten maximus and Glycymeris glycymeris, and two ecologically important species, Abra alba and Ophelia borealis were derived using four contemporary hydrographic variables, i.e. sea surface temperature, sea surface salinity, water depth and sediment type. Consequently, using these ecological envelopes, the Non-Parametric Probalistic Ecological Niche model (NPPEN) was applied to calculate contemporary probabilities of occurrence for each species in the North East Atlantic and to predict potential re-distributions under the climate change scenario A2 for two time periods 2050-2059 and 2090-2099. Results show general northern displacements of the four benthic species from the English Channel into the North Sea and southern Norwegian coast. The projections mostly indicate a reduction of suitable habitat for benthic species with a notable disappearance of their distributions in the English Channel, except for A. alba. However, interpretations should be treated with caution since many uncertainties and assumptions are attached to ecological niche models in general. Furthermore, opening up potential habitats for benthic species does not necessarily imply that the species will actually occupy these sites in the future. The displacement and colonisation success of species are a function of many other non-climatic factors such as species life histories, dispersal abilities, adaptability and community interactions.
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Tang, Cindy Q.; Dong, Yi-Fei; Herrando-Moraira, Sonia; Matsui, Tetsuya; Ohashi, Haruka; He, Long-Yuan; Nakao, Katsuhiro; Tanaka, Nobuyuki; Tomita, Mizuki; Li, Xiao-Shuang; Yan, Hai-Zhong; Peng, Ming-Chun; Hu, Jun; Yang, Ruo-Han; Li, Wang-Jun; Yan, Kai; Hou, Xiuli; Zhang, Zhi-Ying; López-Pujol, Jordi
2017-01-01
This study, using species distribution modeling (involving a new approach that allows for uncertainty), predicts the distribution of climatically suitable areas prevailing during the mid-Holocene, the Last Glacial Maximum (LGM), and at present, and estimates the potential formation of new habitats in 2070 of the endangered and rare Tertiary relict tree Davidia involucrata Baill. The results regarding the mid-Holocene and the LGM demonstrate that south-central and southwestern China have been long-term stable refugia, and that the current distribution is limited to the prehistoric refugia. Given future distribution under six possible climate scenarios, only some parts of the current range of D. involucrata in the mid-high mountains of south-central and southwestern China would be maintained, while some shift west into higher mountains would occur. Our results show that the predicted suitable area offering high probability (0.5‒1) accounts for an average of only 29.2% among the models predicted for the future (2070), making D. involucrata highly vulnerable. We assess and propose priority protected areas in light of climate change. The information provided will also be relevant in planning conservation of other paleoendemic species having ecological traits and distribution ranges comparable to those of D. involucrata. PMID:28272437
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Modeling Hawaiian Ecosystem Degradation due to Invasive Plants under Current and Future Climates
Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; Gon, Sam 'Ohukani'ohi'a; Koob, Gregory A.
2014-01-01
Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions. PMID:24805254
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Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates.
Vorsino, Adam E; Fortini, Lucas B; Amidon, Fred A; Miller, Stephen E; Jacobi, James D; Price, Jonathan P; Gon, Sam 'ohukani'ohi'a; Koob, Gregory A
2014-01-01
Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.
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The Flexible Solar Utility. Preparing for Solar's Impacts to Utility Planning and Operations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sterling, John; Davidovich, Ted; Cory, Karlynn
2015-09-01
This paper seeks to provide a flexible utility roadmap for identifying the steps that need to be taken to place the utility in the best position for addressing solar in the future. Solar growth and the emergence of new technologies will change the electric utility of tomorrow. Although not every utility, region, or market will change in the same way or magnitude, developing a path forward will be needed to reach the Electric System of the Future in the coming decades. In this report, a series of potential future states are identified that could result in drastically different energy mixesmore » and profiles: 1) Business as Usual, 2) Low Carbon, Centralized Generation, 3) Rapid Distributed Energy Resource Growth, 4) Interactivity of Both the Grid and Demand, and 5) Grid or Load Defection. Complicating this process are a series of emerging disruptions; decisions or events that will cause the electric sector to change. Understanding and preparing for these items is critical for the transformation to any of the future states to be successful. Predicting which future state will predominate 15 years from now is not possible; however, utilities still will need to look ahead and try to anticipate how factors will impact their planning, operations, and business models. In order to dig into the potential transformations facing the utility industry, the authors conducted a series of utility interviews, held a working session at a major industry solar conference, and conducted a quantitative survey. To focus conversations, the authors leveraged the Rapid Distributed Energy Resource (DER) Growth future to draw out how utilities would have to adapt from current processes and procedures in order to manage and thrive in that new environment. Distributed solar was investigated specifically, and could serve as a proxy resource for all distributed generation (DG). It can also provide the foundation for all DERs.« less
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Quantifying the transmission potential of pandemic influenza
NASA Astrophysics Data System (ADS)
Chowell, Gerardo; Nishiura, Hiroshi
2008-03-01
This article reviews quantitative methods to estimate the basic reproduction number of pandemic influenza, a key threshold quantity to help determine the intensity of interventions required to control the disease. Although it is difficult to assess the transmission potential of a probable future pandemic, historical epidemiologic data is readily available from previous pandemics, and as a reference quantity for future pandemic planning, mathematical and statistical analyses of historical data are crucial. In particular, because many historical records tend to document only the temporal distribution of cases or deaths (i.e. epidemic curve), our review focuses on methods to maximize the utility of time-evolution data and to clarify the detailed mechanisms of the spread of influenza. First, we highlight structured epidemic models and their parameter estimation method which can quantify the detailed disease dynamics including those we cannot observe directly. Duration-structured epidemic systems are subsequently presented, offering firm understanding of the definition of the basic and effective reproduction numbers. When the initial growth phase of an epidemic is investigated, the distribution of the generation time is key statistical information to appropriately estimate the transmission potential using the intrinsic growth rate. Applications of stochastic processes are also highlighted to estimate the transmission potential using similar data. Critically important characteristics of influenza data are subsequently summarized, followed by our conclusions to suggest potential future methodological improvements.
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Architectural Optimization of Digital Libraries
NASA Technical Reports Server (NTRS)
Biser, Aileen O.
1998-01-01
This work investigates performance and scaling issues relevant to large scale distributed digital libraries. Presently, performance and scaling studies focus on specific implementations of production or prototype digital libraries. Although useful information is gained to aid these designers and other researchers with insights to performance and scaling issues, the broader issues relevant to very large scale distributed libraries are not addressed. Specifically, no current studies look at the extreme or worst case possibilities in digital library implementations. A survey of digital library research issues is presented. Scaling and performance issues are mentioned frequently in the digital library literature but are generally not the focus of much of the current research. In this thesis a model for a Generic Distributed Digital Library (GDDL) and nine cases of typical user activities are defined. This model is used to facilitate some basic analysis of scaling issues. Specifically, the calculation of Internet traffic generated for different configurations of the study parameters and an estimate of the future bandwidth needed for a large scale distributed digital library implementation. This analysis demonstrates the potential impact a future distributed digital library implementation would have on the Internet traffic load and raises questions concerning the architecture decisions being made for future distributed digital library designs.
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Guareschi, Simone; Coccia, Cristina; Sánchez-Fernández, David; Carbonell, José Antonio; Velasco, Josefa; Boyero, Luz; Green, Andy J.; Millán, Andrés
2013-01-01
Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv) is a corixid (Hemiptera) originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i) to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii) to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of spread, focusing on different geographical scales. PMID:23555771
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Unified interatomic potential and energy barrier distributions for amorphous oxides.
Trinastic, J P; Hamdan, R; Wu, Y; Zhang, L; Cheng, Hai-Ping
2013-10-21
Amorphous tantala, titania, and hafnia are important oxides for biomedical implants, optics, and gate insulators. Understanding the effects of oxide doping is crucial to optimize performance in these applications. However, no molecular dynamics potentials have been created to date that combine these and other oxides that would allow computational analyses of doping-dependent structural and mechanical properties. We report a novel set of computationally efficient, two-body potentials modeling van der Waals and covalent interactions that reproduce the structural and elastic properties of both pure and doped amorphous oxides. In addition, we demonstrate that the potential accurately produces energy barrier distributions for pure and doped samples. The distributions can be directly compared to experiment and used to calculate physical quantities such as internal friction to understand how doping affects material properties. Future analyses using these potentials will be of great value to determine optimal doping concentrations and material combinations for myriad material science applications.
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Aljaryian, Rasha; Kumar, Lalit; Taylor, Subhashni
2016-10-01
The sunn pest, Eurygaster integriceps (Hemiptera: Scutelleridae), is an economically significant pest throughout Western Asia and Eastern Europe. This study was conducted to examine the possible risk posed by the influence of climate change on its spread. CLIMEX software was used to model its current global distribution. Future invasion potential was investigated using two global climate models (GCMs), CSIRO-Mk3.0 (CS) and MIROC-H (MR), under A1B and A2 emission scenarios for 2030, 2070 and 2100. Dry to temperate climatic areas favour sunn pests. The potential global range for E. integriceps is expected to extend further polewards between latitudes 60° N and 70° N. Northern Europe and Canada will be at risk of sunn pest invasion as cold stress boundaries recede under the emission scenarios of these models. However, current highly suitable areas, such as South Africa and central Australia, will contract where precipitation is projected to decrease substantially with increased heat stress. Estimating the sunn pest's potential geographic distribution and detecting its climatic limits can provide useful information for management strategies and allow biosecurity authorities to plan ahead and reduce the expected harmful economic consequences by identifying the new areas for pest invasion. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
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NASA Technical Reports Server (NTRS)
Hunter, Gary W.; Behbahani, Alireza
2012-01-01
Smart Sensor Systems with wireless capability operational in high temperature, harsh environments are a significant component in enabling future propulsion systems to meet a range of increasingly demanding requirements. These propulsion systems must incorporate technology that will monitor engine component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This paper discusses the motivation towards the development of high temperature, smart wireless sensor systems that include sensors, electronics, wireless communication, and power. The challenges associated with the use of traditional wired sensor systems will be reviewed and potential advantages of Smart Sensor Systems will be discussed. A brief review of potential applications for wireless smart sensor networks and their potential impact on propulsion system operation, with emphasis on Distributed Engine Control and Propulsion Health Management, will be given. A specific example related to the development of high temperature Smart Sensor Systems based on silicon carbide electronics will be discussed. It is concluded that the development of a range of robust smart wireless sensor systems are a foundation for future development of intelligent propulsion systems with enhanced capabilities.
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Modeling potential climate change impacts on the trees of the northeastern United States
Louis Iverson; Anantha Prasad; Stephen Matthews
2008-01-01
We evaluated 134 tree species from the eastern United States for potential response to several scenarios of climate change, and summarized those responses for nine northeastern United States. We modeled and mapped each species individually and show current and potential future distributions for two emission scenarios (A1fi [higher emission] and B1 [lower emission]) and...
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Predicting the Distribution of Commercially Important Invertebrate Stocks under Future Climate
Russell, Bayden D.; Connell, Sean D.; Mellin, Camille; Brook, Barry W.; Burnell, Owen W.; Fordham, Damien A.
2012-01-01
The future management of commercially exploited species is challenging because techniques used to predict the future distribution of stocks under climate change are currently inadequate. We projected the future distribution and abundance of two commercially harvested abalone species (blacklip abalone, Haliotis rubra and greenlip abalone, H. laevigata) inhabiting coastal South Australia, using multiple species distribution models (SDM) and for decadal time slices through to 2100. Projections are based on two contrasting global greenhouse gas emissions scenarios. The SDMs identified August (winter) Sea Surface Temperature (SST) as the best descriptor of abundance and forecast that warming of winter temperatures under both scenarios may be beneficial to both species by allowing increased abundance and expansion into previously uninhabited coasts. This range expansion is unlikely to be realised, however, as projected warming of March SST is projected to exceed temperatures which cause up to 10-fold increases in juvenile mortality. By linking fine-resolution forecasts of sea surface temperature under different climate change scenarios to SDMs and physiological experiments, we provide a practical first approximation of the potential impact of climate-induced change on two species of marine invertebrates in the same fishery. PMID:23251326
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Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates
Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; `Ohukani`ohi`a Gon, Sam; Koob, Gregory A.
2014-01-01
Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.
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Schlaepfer, Daniel R.; Taylor, Kyle A.; Pennington, Victoria E.; Nelson, Kellen N.; Martin, Trace E.; Rottler, Caitlin M.; Lauenroth, William K.; Bradford, John B.
2015-01-01
Many semi-arid plant communities in western North America are dominated by big sagebrush. These ecosystems are being reduced in extent and quality due to economic development, invasive species, and climate change. These pervasive modifications have generated concern about the long-term viability of sagebrush habitat and sagebrush-obligate wildlife species (notably greater sage-grouse), highlighting the need for better understanding of the future big sagebrush distribution, particularly at the species' range margins. These leading and trailing edges of potential climate-driven sagebrush distribution shifts are likely to be areas most sensitive to climate change. We used a process-based regeneration model for big sagebrush, which simulates potential germination and seedling survival in response to climatic and edaphic conditions and tested expectations about current and future regeneration responses at trailing and leading edges that were previously identified using traditional species distribution models. Our results confirmed expectations of increased probability of regeneration at the leading edge and decreased probability of regeneration at the trailing edge below current levels. Our simulations indicated that soil water dynamics at the leading edge became more similar to the typical seasonal ecohydrological conditions observed within the current range of big sagebrush ecosystems. At the trailing edge, an increased winter and spring dryness represented a departure from conditions typically supportive of big sagebrush. Our results highlighted that minimum and maximum daily temperatures as well as soil water recharge and summer dry periods are important constraints for big sagebrush regeneration. Overall, our results confirmed previous predictions, i.e., we see consistent changes in areas identified as trailing and leading edges; however, we also identified potential local refugia within the trailing edge, mostly at sites at higher elevation. Decreasing regeneration probability at the trailing edge underscores the Schlaepfer et al. Future regeneration potential of big sagebrush potential futility of efforts to preserve and/or restore big sagebrush in these areas. Conversely, increasing regeneration probability at the leading edge suggest a growing potential for conflicts in management goals between maintaining existing grasslands by preventing sagebrush expansion versus accepting a shift in plant community composition to sagebrush dominance.
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Mauser, Wolfram; Klepper, Gernot; Zabel, Florian; Delzeit, Ruth; Hank, Tobias; Putzenlechner, Birgitta; Calzadilla, Alvaro
2015-01-01
Global biomass demand is expected to roughly double between 2005 and 2050. Current studies suggest that agricultural intensification through optimally managed crops on today's cropland alone is insufficient to satisfy future demand. In practice though, improving crop growth management through better technology and knowledge almost inevitably goes along with (1) improving farm management with increased cropping intensity and more annual harvests where feasible and (2) an economically more efficient spatial allocation of crops which maximizes farmers' profit. By explicitly considering these two factors we show that, without expansion of cropland, today's global biomass potentials substantially exceed previous estimates and even 2050s' demands. We attribute 39% increase in estimated global production potentials to increasing cropping intensities and 30% to the spatial reallocation of crops to their profit-maximizing locations. The additional potentials would make cropland expansion redundant. Their geographic distribution points at possible hotspots for future intensification. PMID:26558436
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Mauser, Wolfram; Klepper, Gernot; Zabel, Florian; Delzeit, Ruth; Hank, Tobias; Putzenlechner, Birgitta; Calzadilla, Alvaro
2015-11-12
Global biomass demand is expected to roughly double between 2005 and 2050. Current studies suggest that agricultural intensification through optimally managed crops on today's cropland alone is insufficient to satisfy future demand. In practice though, improving crop growth management through better technology and knowledge almost inevitably goes along with (1) improving farm management with increased cropping intensity and more annual harvests where feasible and (2) an economically more efficient spatial allocation of crops which maximizes farmers' profit. By explicitly considering these two factors we show that, without expansion of cropland, today's global biomass potentials substantially exceed previous estimates and even 2050s' demands. We attribute 39% increase in estimated global production potentials to increasing cropping intensities and 30% to the spatial reallocation of crops to their profit-maximizing locations. The additional potentials would make cropland expansion redundant. Their geographic distribution points at possible hotspots for future intensification.
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Kistner, Erica Jean
2017-12-08
The invasive brown marmorated stink bug, Halyomorpha halys (Stål; Hemiptera: Pentatomidae), has recently emerged as a harmful pest of horticultural crops in North America and Europe. Native to East Asia, this highly polyphagous insect is spreading rapidly worldwide. Climate change will add further complications to managing this species in terms of both geographic distribution and population growth. This study used CLIMEX to compare potential H. halys distribution under recent and future climate models using one emission scenario (A2) with two different global circulation models, CSIRO Mk3.0 and MIROC-H. Simulated changes in seasonal phenology and voltinism were examined. Under the possible future climate scenarios, suitable range in Europe expands northward. In North America, the suitable H. halys range shifts northward into Canada and contracts from its southern temperature range limits in the United States due to increased heat stress. Prolonged periods of warm temperatures resulted in longer H. halys growing seasons. However, future climate scenarios indicated that rising summer temperatures decrease H. halys growth potential compared to recent climatic conditions, which in turn, may reduce mid-summer crop damage. Climate change may increase the number of H. halys generations produced annually, thereby enabling the invasive insect to become multivoltine in the northern latitudes of North America and Europe where it is currently reported to be univoltine. These results indicate prime horticultural production areas in Europe, the northeastern United States, and southeastern Canada are at greatest risk from H. halys under both current and possible future climates. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.
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Crayfishes (Decapoda : Cambaridae) of Oklahoma: identification, distributions, and natural history.
Morehouse, Reid L; Tobler, Michael
2013-01-01
We furnish an updated crayfish species list for the state of Oklahoma (United States of America), including an updated and illustrated dichotomous key. In addition, we include species accounts that summarize general characteristics, life coloration, similar species, distribution and habitat, life history, and syntopic species. Current and potential distributions were analyzed using ecological niche models to provide a critical resource for the identification of areas with conservation priorities and potential susceptibility to invasive species. Currently, Oklahoma harbors 30 species of crayfish, two of which were recently discovered. Eastern Oklahoma has the highest species diversity, as this area represents the western distribution extent for several species. The work herein provides baseline data for future work on crayfish biology and conservation in Oklahoma and surrounding states.
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Transmission and Distribution Efficiency Improvement Rearch and Development Survey.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brooks, C.L.; Westinghouse Electric Corporation. Advanced Systems Technology.
Purpose of this study was to identify and quantify those technologies for improving transmission and distribution (T and D) system efficiency that could provide the greatest benefits for utility customers in the Pacific Northwest. Improving the efficiency of transmission and distribution systems offers a potential source of conservation within the utility sector. An extensive review of this field resulted in a list of 49 state-of-the-art technologies and 39 future technologies. Of these, 15 from the former list and 7 from the latter were chosen as the most promising and then submitted to an evaluative test - a modeled sample systemmore » for Benton County PUD, a utility with characteristics typical of a BPA customer system. Reducing end-use voltage on secondary distribution systems to decrease the energy consumption of electrical users when possible, called ''Conservation Voltage Reduction,'' was found to be the most cost effective state-of-the-art technology. Voltampere reactive (var) optimization is a similarly cost effective alternative. The most significant reduction in losses on the transmission and distribution system would be achieved through the replacement of standard transformers with high efficiency transformers, such as amorphous steel transformers. Of the future technologies assessed, the ''Distribution Static VAR Generator'' appears to have the greatest potential for technological breakthroughs and, therefore in time, commercialization. ''Improved Dielectric Materials,'' with a relatively low cost and high potential for efficiency improvement, warrant R and D consideration. ''Extruded Three-Conductor Cable'' and ''Six- and Twelve-Phase Transmission'' programs provide only limited gains in efficiency and applicability and are therefore the least cost effective.« less
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ERIC Educational Resources Information Center
Michener, Charles D.
1973-01-01
Discusses the unusually aggressive Brazilian honeybee, which exhibits many of the attributes of its African antecedants. Describes its abundance and distribution, behaviorial characteristics, future spread, and the potential impact of the Brazilian bee in North America. (JR)
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Mishra, U.; Jastrow, J.D.; Matamala, R.; Hugelius, G.; Koven, C.D.; Harden, Jennifer W.; Ping, S.L.; Michaelson, G.J.; Fan, Z.; Miller, R.M.; McGuire, A.D.; Tarnocai, C.; Kuhry, P.; Riley, W.J.; Schaefer, K.; Schuur, E.A.G.; Jorgenson, M.T.; Hinzman, L.D.
2013-01-01
The vast amount of organic carbon (OC) stored in soils of the northern circumpolar permafrost region is a potentially vulnerable component of the global carbon cycle. However, estimates of the quantity, decomposability, and combustibility of OC contained in permafrost-region soils remain highly uncertain, thereby limiting our ability to predict the release of greenhouse gases due to permafrost thawing. Substantial differences exist between empirical and modeling estimates of the quantity and distribution of permafrost-region soil OC, which contribute to large uncertainties in predictions of carbon–climate feedbacks under future warming. Here, we identify research challenges that constrain current assessments of the distribution and potential decomposability of soil OC stocks in the northern permafrost region and suggest priorities for future empirical and modeling studies to address these challenges.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Alstone, Peter; Potter, Jennifer; Piette, Mary Ann
California’s legislative and regulatory goals for renewable energy are changing the power grid’s dynamics. Increased variable generation resource penetration connected to the bulk power system, as well as, distributed energy resources (DERs) connected to the distribution system affect the grid’s reliable operation over many different time scales (e.g., days to hours to minutes to seconds). As the state continues this transition, it will require careful planning to ensure resources with the right characteristics are available to meet changing grid management needs. Demand response (DR) has the potential to provide important resources for keeping the electricity grid stable and efficient, tomore » defer upgrades to generation, transmission and distribution systems, and to deliver customer economic benefits. This study estimates the potential size and cost of future DR resources for California’s three investor-owned utilities (IOUs): Pacific Gas and Electric Company (PG&E), Southern California Edison Company (SCE), and San Diego Gas & Electric Company (SDG&E). Our goal is to provide data-driven insights as the California Public Utilities Commission (CPUC) evaluates how to enhance DR’s role in meeting California’s resource planning needs and operational requirements. We address two fundamental questions: 1. What cost-competitive DR service types will meet California’s future grid needs as it moves towards clean energy and advanced infrastructure? 2. What is the size and cost of the expected resource base for the DR service types?« less
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Amorim, Francisco; Carvalho, Sílvia B; Honrado, João; Rebelo, Hugo
2014-01-01
Here we develop a framework to design multi-species monitoring networks using species distribution models and conservation planning tools to optimize the location of monitoring stations to detect potential range shifts driven by climate change. For this study, we focused on seven bat species in Northern Portugal (Western Europe). Maximum entropy modelling was used to predict the likely occurrence of those species under present and future climatic conditions. By comparing present and future predicted distributions, we identified areas where each species is likely to gain, lose or maintain suitable climatic space. We then used a decision support tool (the Marxan software) to design three optimized monitoring networks considering: a) changes in species likely occurrence, b) species conservation status, and c) level of volunteer commitment. For present climatic conditions, species distribution models revealed that areas suitable for most species occur in the north-eastern part of the region. However, areas predicted to become climatically suitable in the future shifted towards west. The three simulated monitoring networks, adaptable for an unpredictable volunteer commitment, included 28, 54 and 110 sampling locations respectively, distributed across the study area and covering the potential full range of conditions where species range shifts may occur. Our results show that our framework outperforms the traditional approach that only considers current species ranges, in allocating monitoring stations distributed across different categories of predicted shifts in species distributions. This study presents a straightforward framework to design monitoring schemes aimed specifically at testing hypotheses about where and when species ranges may shift with climatic changes, while also ensuring surveillance of general population trends.
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Huff, G.F.
2004-01-01
Increasing demand on the limited supplies of freshwater in the desert Southwest, as well as other parts of the United States, has increased the level of interest in saline-water resources. Saline ground water has long been recognized as a potentially important contributor to water supply in the Southwest, as demonstrated by the number of hydrologic, geologic, and engineering studies on the distribution of saline water and the feasibility of desalination. Potential future study needs include investigating and documenting the three-dimensional distribution of salinity and chemical composition of saline-water resources and the hydraulic properties of aquifers containing these saline-water resources, assessing the chemical suitability of saline water for use with existing and anticipated desalination technologies, simulating the effect of withdrawal of saline ground water on water levels and water composition in saline and adjoining or overlying freshwater aquifers, and determining the suitability of target geologic formations for injection of desalination-generated waste.
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A quasi-static model of global atmospheric electricity. I - The lower atmosphere
NASA Technical Reports Server (NTRS)
Hays, P. B.; Roble, R. G.
1979-01-01
A quasi-steady model of global lower atmospheric electricity is presented. The model considers thunderstorms as dipole electric generators that can be randomly distributed in various regions and that are the only source of atmospheric electricity and includes the effects of orography and electrical coupling along geomagnetic field lines in the ionosphere and magnetosphere. The model is used to calculate the global distribution of electric potential and current for model conductivities and assumed spatial distributions of thunderstorms. Results indicate that large positive electric potentials are generated over thunderstorms and penetrate to ionospheric heights and into the conjugate hemisphere along magnetic field lines. The perturbation of the calculated electric potential and current distributions during solar flares and subsequent Forbush decreases is discussed, and future measurements of atmospheric electrical parameters and modifications of the model which would improve the agreement between calculations and measurements are suggested.
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Poulos, Helen M.; Chernoff, Barry; Fuller, Pam L.; Butman, David
2012-01-01
Predicting the future spread of non-native aquatic species continues to be a high priority for natural resource managers striving to maintain biodiversity and ecosystem function. Modeling the potential distributions of alien aquatic species through spatially explicit mapping is an increasingly important tool for risk assessment and prediction. Habitat modeling also facilitates the identification of key environmental variables influencing species distributions. We modeled the potential distribution of an aggressive invasive minnow, the red shiner (Cyprinella lutrensis), in waterways of the conterminous United States using maximum entropy (Maxent). We used inventory records from the USGS Nonindigenous Aquatic Species Database, native records for C. lutrensis from museum collections, and a geographic information system of 20 raster climatic and environmental variables to produce a map of potential red shiner habitat. Summer climatic variables were the most important environmental predictors of C. lutrensis distribution, which was consistent with the high temperature tolerance of this species. Results from this study provide insights into the locations and environmental conditions in the US that are susceptible to red shiner invasion.
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Pholkern, Kewaree; Saraphirom, Phayom; Srisuk, Kriengsak
2018-08-15
The Central Huai Luang Basin is one of the important rice producing areas of Udon Thani Province in Northeastern Thailand. The basin is underlain by the rock salt layers of the Maha Sarakham Formation and is the source of saline groundwater and soil salinity. The regional and local groundwater flow systems are the major mechanisms responsible for spreading saline groundwater and saline soils in this basin. Climate change may have an impact on groundwater recharge, on water table depth and the consequences of waterlogging, and on the distribution of soil salinity in this basin. Six future climate conditions from the SEACAM and CanESM2 models were downscaled to investigate the potential impact of future climate conditions on groundwater quantity and quality in this basin. The potential impact was investigated by using a set of numerical models, namely HELP3 and SEAWAT, to estimate the groundwater recharge and flow and the salt transport of groundwater simulation, respectively. The results revealed that within next 30years (2045), the future average annual temperature is projected to increase by 3.1°C and 2.2°C under SEACAM and CanESM2 models, respectively, while the future precipitation is projected to decrease by 20.85% under SEACAM and increase by 18.35% under the CanESM2. Groundwater recharge is projected to increase under the CanESM2 model and to slightly decrease under the SEACAM model. Moreover, for all future climate conditions, the depths of the groundwater water table are projected to continuously increase. The results showed the impact of climate change on salinity distribution for both the deep and shallow groundwater systems. The salinity distribution areas are projected to increase by about 8.08% and 56.92% in the deep and shallow groundwater systems, respectively. The waterlogging areas are also projected to expand by about 63.65% from the baseline period. Copyright © 2018 Elsevier B.V. All rights reserved.
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Data documenting the potential distribution of Aedes aegypti in the center of Veracruz, Mexico.
Estrada-Contreras, Israel; Sandoval-Ruiz, César A; Mendoza-Palmero, Fredy S; Ibáñez-Bernal, Sergio; Equihua, Miguel; Benítez, Griselda
2017-02-01
The data presented in this article are related to the research article entitled "Establishment of Aedes aegypti (L.) in mountainous regions in Mexico: Increasing number of population at risk of mosquito-borne disease and future climate conditions" (M. Equihua, S. Ibáñez-Bernal, G. Benítez, I. Estrada-Contreras, C.A. Sandoval-Ruiz, F.S. Mendoza-Palmero, 2016) [1]. This article provides presence records in shapefile format used to generate maps of potential distribution of Aedes aegypti with different climate change scenarios as well as each of the maps obtained in raster format. In addition, tables with values of potential distribution of the vector as well as the average values of probability of presence including data of the mosquito incidence along the altitudinal range.
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A global map of suitability for coastal Vibrio cholerae under current and future climate conditions.
Escobar, Luis E; Ryan, Sadie J; Stewart-Ibarra, Anna M; Finkelstein, Julia L; King, Christine A; Qiao, Huijie; Polhemus, Mark E
2015-09-01
Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.
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Alternative Future Fleet Platform Architecture Study
2016-10-27
establishing sea control - projecting power - winning decisively To accomplish these missions, the Navy Project Team derived a ‘Distributed...allies and partners, and deter potential aggressors. The Distributed Fleet was further conceived to deliver decisive combat power , as part of a joint...global information system – the information that rides on the servers, undersea cables, satellites, and wireless networks that increasingly envelop
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Tonnang, Henri E Z; Kangalawe, Richard Y M; Yanda, Pius Z
2010-04-23
Malaria is rampant in Africa and causes untold mortality and morbidity. Vector-borne diseases are climate sensitive and this has raised considerable concern over the implications of climate change on future disease risk. The problem of malaria vectors (Anopheles mosquitoes) shifting from their traditional locations to invade new zones is an important concern. The vision of this study was to exploit the sets of information previously generated by entomologists, e.g. on geographical range of vectors and malaria distribution, to build models that will enable prediction and mapping the potential redistribution of Anopheles mosquitoes in Africa. The development of the modelling tool was carried out through calibration of CLIMEX parameters. The model helped estimate the potential geographical distribution and seasonal abundance of the species in relation to climatic factors. These included temperature, rainfall and relative humidity, which characterized the living environment for Anopheles mosquitoes. The same parameters were used in determining the ecoclimatic index (EI). The EI values were exported to a GIS package for special analysis and proper mapping of the potential future distribution of Anopheles gambiae and Anophles arabiensis within the African continent under three climate change scenarios. These results have shown that shifts in these species boundaries southward and eastward of Africa may occur rather than jumps into quite different climatic environments. In the absence of adequate control, these predictions are crucial in understanding the possible future geographical range of the vectors and the disease, which could facilitate planning for various adaptation options. Thus, the outputs from this study will be helpful at various levels of decision making, for example, in setting up of an early warning and sustainable strategies for climate change and climate change adaptation for malaria vectors control programmes in Africa.
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NASA Technical Reports Server (NTRS)
Hearty, Thomas; Savtchenko, Andrey; Vollmer, Bruce; Albayrak, Arif; Theobald, Mike; Esfandiari, Ed; Wei, Jennifer
2015-01-01
This talk will describe the support and distribution of CO2 data products from OCO-2, AIRS, and ACOS, that are archived and distributed from the Goddard Earth Sciences Data and Information Services Center. We will provide a brief summary of the current online archive and distribution metrics for the OCO-2 Level 1 products and plans for the Level 2 products. We will also describe collaborative data sets and services (e.g., matchups with other sensors) and solicit feedback for potential future services.
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Acevedo, Pelayo; Melo-Ferreira, José; Real, Raimundo; Alves, Paulo Célio
2012-01-01
The application of species distribution models (SDMs) in ecology and conservation biology is increasing and assuming an important role, mainly because they can be used to hindcast past and predict current and future species distributions. However, the accuracy of SDMs depends on the quality of the data and on appropriate theoretical frameworks. In this study, comprehensive data on the current distribution of the Iberian hare (Lepus granatensis) were used to i) determine the species' ecogeographical constraints, ii) hindcast a climatic model for the last glacial maximum (LGM), relating it to inferences derived from molecular studies, and iii) calibrate a model to assess the species future distribution trends (up to 2080). Our results showed that the climatic factor (in its pure effect and when it is combined with the land-cover factor) is the most important descriptor of the current distribution of the Iberian hare. In addition, the model's output was a reliable index of the local probability of species occurrence, which is a valuable tool to guide species management decisions and conservation planning. Climatic potential obtained for the LGM was combined with molecular data and the results suggest that several glacial refugia may have existed for the species within the major Iberian refugium. Finally, a high probability of occurrence of the Iberian hare in the current species range and a northward expansion were predicted for future. Given its current environmental envelope and evolutionary history, we discuss the macroecology of the Iberian hare and its sensitivity to climate change.
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Acevedo, Pelayo; Melo-Ferreira, José; Real, Raimundo; Alves, Paulo Célio
2012-01-01
The application of species distribution models (SDMs) in ecology and conservation biology is increasing and assuming an important role, mainly because they can be used to hindcast past and predict current and future species distributions. However, the accuracy of SDMs depends on the quality of the data and on appropriate theoretical frameworks. In this study, comprehensive data on the current distribution of the Iberian hare (Lepus granatensis) were used to i) determine the species’ ecogeographical constraints, ii) hindcast a climatic model for the last glacial maximum (LGM), relating it to inferences derived from molecular studies, and iii) calibrate a model to assess the species future distribution trends (up to 2080). Our results showed that the climatic factor (in its pure effect and when it is combined with the land-cover factor) is the most important descriptor of the current distribution of the Iberian hare. In addition, the model’s output was a reliable index of the local probability of species occurrence, which is a valuable tool to guide species management decisions and conservation planning. Climatic potential obtained for the LGM was combined with molecular data and the results suggest that several glacial refugia may have existed for the species within the major Iberian refugium. Finally, a high probability of occurrence of the Iberian hare in the current species range and a northward expansion were predicted for future. Given its current environmental envelope and evolutionary history, we discuss the macroecology of the Iberian hare and its sensitivity to climate change. PMID:23272115
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Xu, Zhonglin; Feng, Zhaodong; Yang, Jianjun; Zheng, Jianghua; Zhang, Fang
2013-01-01
Future climate change has been predicted to affect the potential distribution of plant species. However, only few studies have addressed how invasive species may respond to future climate change despite the known effects of plant species invasion on nutrient cycles, ecosystem functions, and agricultural yields. In this study, we predicted the potential distributions of two invasive species, Rumex crispus and Typha latifolia, under current and future (2050) climatic conditions. Future climate scenarios considered in our study include A1B, A2, A2A, B1, and B2A. We found that these two species will lose their habitat under the A1B, A2, A2A, and B1 scenarios. Their distributions will be maintained under future climatic conditions related to B2A scenarios, but the total area will be less than 10% of that under the current climatic condition. We also investigated variations of the most influential climatic variables that are likely to cause habitat loss of the two species. Our results demonstrate that rising mean annual temperature, variations of the coldest quarter, and precipitation of the coldest quarter are the main factors contributing to habitat loss of R. crispus. For T. latifolia, the main factors are rising mean annual temperature, variations in temperature of the coldest quarter, mean annual precipitation, and precipitation of the coldest quarter. These results demonstrate that the warmer and wetter climatic conditions of the coldest season (or month) will be mainly responsible for habitat loss of R. crispus and T. latifolia in the future. We also discuss uncertainties related to our study (and similar studies) and suggest that particular attention should be directed toward the manner in which invasive species cope with rapid climate changes because evolutionary change can be rapid for species that invade new areas. PMID:23923020
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Lambert, Emily; Pierce, Graham J; Hall, Karen; Brereton, Tom; Dunn, Timothy E; Wall, Dave; Jepson, Paul D; Deaville, Rob; MacLeod, Colin D
2014-06-01
There is increasing evidence that the distributions of a large number of species are shifting with global climate change as they track changing surface temperatures that define their thermal niche. Modelling efforts to predict species distributions under future climates have increased with concern about the overall impact of these distribution shifts on species ecology, and especially where barriers to dispersal exist. Here we apply a bio-climatic envelope modelling technique to investigate the impacts of climate change on the geographic range of ten cetacean species in the eastern North Atlantic and to assess how such modelling can be used to inform conservation and management. The modelling process integrates elements of a species' habitat and thermal niche, and employs "hindcasting" of historical distribution changes in order to verify the accuracy of the modelled relationship between temperature and species range. If this ability is not verified, there is a risk that inappropriate or inaccurate models will be used to make future predictions of species distributions. Of the ten species investigated, we found that while the models for nine could successfully explain current spatial distribution, only four had a good ability to predict distribution changes over time in response to changes in water temperature. Applied to future climate scenarios, the four species-specific models with good predictive abilities indicated range expansion in one species and range contraction in three others, including the potential loss of up to 80% of suitable white-beaked dolphin habitat. Model predictions allow identification of affected areas and the likely time-scales over which impacts will occur. Thus, this work provides important information on both our ability to predict how individual species will respond to future climate change and the applicability of predictive distribution models as a tool to help construct viable conservation and management strategies. © 2014 John Wiley & Sons Ltd.
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Atlas of climate change effects in 150 bird species of the Eastern United States
Stephen Matthews; Raymond O' Connor; Louis R. Iverson; Anantha M. Prasad
2004-01-01
NOTE: Instructions for navigating this publication can be found on the front cover. This atlas documents the current and potential future distribution of 150 common bird species in the Eastern United States. Distribution data for individual species were derived from the Breeding Bird Survey (BBS) from 1981 to 1990. Regression tree analysis was used to model the BBS...
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Potential economic benefits of adapting agricultural production systems to future climate change
Fagre, Daniel B.; Pederson, Gregory; Bengtson, Lindsey E.; Prato, Tony; Qui, Zeyuan; Williams, Jimmie R.
2010-01-01
Potential economic impacts of future climate change on crop enterprise net returns and annual net farm income (NFI) are evaluated for small and large representative farms in Flathead Valley in Northwest Montana. Crop enterprise net returns and NFI in an historical climate period (1960–2005) and future climate period (2006–2050) are compared when agricultural production systems (APSs) are adapted to future climate change. Climate conditions in the future climate period are based on the A1B, B1, and A2 CO2 emission scenarios from the Intergovernmental Panel on Climate Change Fourth Assessment Report. Steps in the evaluation include: (1) specifying crop enterprises and APSs (i.e., combinations of crop enterprises) in consultation with locals producers; (2) simulating crop yields for two soils, crop prices, crop enterprises costs, and NFIs for APSs; (3) determining the dominant APS in the historical and future climate periods in terms of NFI; and (4) determining whether NFI for the dominant APS in the historical climate period is superior to NFI for the dominant APS in the future climate period. Crop yields are simulated using the Environmental/Policy Integrated Climate (EPIC) model and dominance comparisons for NFI are based on the stochastic efficiency with respect to a function (SERF) criterion. Probability distributions that best fit the EPIC-simulated crop yields are used to simulate 100 values for crop yields for the two soils in the historical and future climate periods. Best-fitting probability distributions for historical inflation-adjusted crop prices and specified triangular probability distributions for crop enterprise costs are used to simulate 100 values for crop prices and crop enterprise costs. Averaged over all crop enterprises, farm sizes, and soil types, simulated net return per ha averaged over all crop enterprises decreased 24% and simulated mean NFI for APSs decreased 57% between the historical and future climate periods. Although adapting APSs to future climate change is advantageous (i.e., NFI with adaptation is superior to NFI without adaptation based on SERF), in six of the nine cases in which adaptation is advantageous, NFI with adaptation in the future climate period is inferior to NFI in the historical climate period. Therefore, adaptation of APSs to future climate change in Flathead Valley is insufficient to offset the adverse impacts on NFI of such change.
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Potential economic benefits of adapting agricultural production systems to future climate change.
Prato, Tony; Zeyuan, Qiu; Pederson, Gregory; Fagre, Dan; Bengtson, Lindsey E; Williams, Jimmy R
2010-03-01
Potential economic impacts of future climate change on crop enterprise net returns and annual net farm income (NFI) are evaluated for small and large representative farms in Flathead Valley in Northwest Montana. Crop enterprise net returns and NFI in an historical climate period (1960-2005) and future climate period (2006-2050) are compared when agricultural production systems (APSs) are adapted to future climate change. Climate conditions in the future climate period are based on the A1B, B1, and A2 CO(2) emission scenarios from the Intergovernmental Panel on Climate Change Fourth Assessment Report. Steps in the evaluation include: (1) specifying crop enterprises and APSs (i.e., combinations of crop enterprises) in consultation with locals producers; (2) simulating crop yields for two soils, crop prices, crop enterprises costs, and NFIs for APSs; (3) determining the dominant APS in the historical and future climate periods in terms of NFI; and (4) determining whether NFI for the dominant APS in the historical climate period is superior to NFI for the dominant APS in the future climate period. Crop yields are simulated using the Environmental/Policy Integrated Climate (EPIC) model and dominance comparisons for NFI are based on the stochastic efficiency with respect to a function (SERF) criterion. Probability distributions that best fit the EPIC-simulated crop yields are used to simulate 100 values for crop yields for the two soils in the historical and future climate periods. Best-fitting probability distributions for historical inflation-adjusted crop prices and specified triangular probability distributions for crop enterprise costs are used to simulate 100 values for crop prices and crop enterprise costs. Averaged over all crop enterprises, farm sizes, and soil types, simulated net return per ha averaged over all crop enterprises decreased 24% and simulated mean NFI for APSs decreased 57% between the historical and future climate periods. Although adapting APSs to future climate change is advantageous (i.e., NFI with adaptation is superior to NFI without adaptation based on SERF), in six of the nine cases in which adaptation is advantageous, NFI with adaptation in the future climate period is inferior to NFI in the historical climate period. Therefore, adaptation of APSs to future climate change in Flathead Valley is insufficient to offset the adverse impacts on NFI of such change.
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Coupling of pollination services and coffee suitability under climate change.
Imbach, Pablo; Fung, Emily; Hannah, Lee; Navarro-Racines, Carlos E; Roubik, David W; Ricketts, Taylor H; Harvey, Celia A; Donatti, Camila I; Läderach, Peter; Locatelli, Bruno; Roehrdanz, Patrick R
2017-09-26
Climate change will cause geographic range shifts for pollinators and major crops, with global implications for food security and rural livelihoods. However, little is known about the potential for coupled impacts of climate change on pollinators and crops. Coffee production exemplifies this issue, because large losses in areas suitable for coffee production have been projected due to climate change and because coffee production is dependent on bee pollination. We modeled the potential distributions of coffee and coffee pollinators under current and future climates in Latin America to understand whether future coffee-suitable areas will also be suitable for pollinators. Our results suggest that coffee-suitable areas will be reduced 73-88% by 2050 across warming scenarios, a decline 46-76% greater than estimated by global assessments. Mean bee richness will decline 8-18% within future coffee-suitable areas, but all are predicted to contain at least 5 bee species, and 46-59% of future coffee-suitable areas will contain 10 or more species. In our models, coffee suitability and bee richness each increase (i.e., positive coupling) in 10-22% of future coffee-suitable areas. Diminished coffee suitability and bee richness (i.e., negative coupling), however, occur in 34-51% of other areas. Finally, in 31-33% of the future coffee distribution areas, bee richness decreases and coffee suitability increases. Assessing coupled effects of climate change on crop suitability and pollination can help target appropriate management practices, including forest conservation, shade adjustment, crop rotation, or status quo, in different regions.
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Theoretical Framework for Integrating Distributed Energy Resources into Distribution Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lian, Jianming; Wu, Di; Kalsi, Karanjit
This paper focuses on developing a novel theoretical framework for effective coordination and control of a large number of distributed energy resources in distribution systems in order to more reliably manage the future U.S. electric power grid under the high penetration of renewable generation. The proposed framework provides a systematic view of the overall structure of the future distribution systems along with the underlying information flow, functional organization, and operational procedures. It is characterized by the features of being open, flexible and interoperable with the potential to support dynamic system configuration. Under the proposed framework, the energy consumption of variousmore » DERs is coordinated and controlled in a hierarchical way by using market-based approaches. The real-time voltage control is simultaneously considered to complement the real power control in order to keep nodal voltages stable within acceptable ranges during real time. In addition, computational challenges associated with the proposed framework are also discussed with recommended practices.« less
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Lemoine, Nathan P
2015-01-01
Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months while encountering reduced habitat suitability throughout the northern migration.
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Lemoine, Nathan P.
2015-01-01
Climate change can profoundly alter species’ distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months while encountering reduced habitat suitability throughout the northern migration. PMID:25705876
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Durante, Leonardo M; Cruz, Igor C S; Lotufo, Tito M C
2018-01-01
Palythoa caribaeorum is a zoanthid often dominant in shallow rocky environments along the west coast of the Atlantic Ocean, from the tropics to the subtropics. This species has high environmental tolerance and is a good space competitor in reef environments. Considering current and future scenarios in the global climate regime, this study aimed to model and analyze the distribution of P. caribaeorum , generating maps of potential distribution for the present and the year 2100. The distribution was modeled using maximum entropy (Maxent) based on 327 occurrence sites retrieved from the literature. Calcite concentration, maximum chlorophyll- a concentration, salinity, pH, and temperature range yielded a model with the smallest Akaike information criterion (2649.8), and were used in the present and future distribution model. Data from the HadGEM2-ES climate model were used to generate the projections for the year 2100. The present distribution of P. caribaeorum shows that parts of the Brazilian coast, Caribbean Sea, and Florida are suitable regions for the species, as they are characterized by high salinity and pH and small temperature variation. An expansion of the species' distribution was forecast northward under mild climate scenarios, while a decrease of suitable areas was forecast in the south. In the climate scenario with the most intense changes, P. caribaeorum would lose one-half of its suitable habitats, including the northernmost and southernmost areas of its distribution. The Caribbean Sea and northeastern Brazil, as well as other places under the influence of coastal upwellings, may serve as potential havens for this species.
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Cruz, Igor C.S.
2018-01-01
Palythoa caribaeorum is a zoanthid often dominant in shallow rocky environments along the west coast of the Atlantic Ocean, from the tropics to the subtropics. This species has high environmental tolerance and is a good space competitor in reef environments. Considering current and future scenarios in the global climate regime, this study aimed to model and analyze the distribution of P. caribaeorum, generating maps of potential distribution for the present and the year 2100. The distribution was modeled using maximum entropy (Maxent) based on 327 occurrence sites retrieved from the literature. Calcite concentration, maximum chlorophyll-a concentration, salinity, pH, and temperature range yielded a model with the smallest Akaike information criterion (2649.8), and were used in the present and future distribution model. Data from the HadGEM2-ES climate model were used to generate the projections for the year 2100. The present distribution of P. caribaeorum shows that parts of the Brazilian coast, Caribbean Sea, and Florida are suitable regions for the species, as they are characterized by high salinity and pH and small temperature variation. An expansion of the species’ distribution was forecast northward under mild climate scenarios, while a decrease of suitable areas was forecast in the south. In the climate scenario with the most intense changes, P. caribaeorum would lose one-half of its suitable habitats, including the northernmost and southernmost areas of its distribution. The Caribbean Sea and northeastern Brazil, as well as other places under the influence of coastal upwellings, may serve as potential havens for this species. PMID:29785350
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NASA Astrophysics Data System (ADS)
Nabout, João Carlos; Magalhães, Mara Rúbia; de Amorim Gomes, Marcos Aurélio; da Cunha, Hélida Ferreira
2016-04-01
The global Climate change may affect biodiversity and the functioning of ecosystems by changing the appropriate locations for the development and establishment of the species. The Hancornia speciosa, popularly called Mangaba, is a plant species that has potential commercial value and contributes to rural economic activities in Brazil. The aim of this study was to evaluate the impact of global climate change on the potential geographic distribution, productivity, and value of production of H. speciosa in Brazil. We used MaxEnt to estimate the potential geographic distribution of the species in current and future (2050) climate scenarios. We obtained the productivity and value of production for 74 municipalities in Brazil. Moreover, to explain the variation the productivity and value of production, we constructed 15 models based on four variables: two ecological (ecological niche model and the presence of Unity of conservation) and two socio-economic (gross domestic product and human developed index). The models were selected using Akaike Information Criteria. Our results suggest that municipalities currently harvesting H. speciosa will have lower harvest rates in the future (mainly in northeastern Brazil). The best model to explain the productivity was ecological niche model; thus, municipalities with higher productivity are inserted in regions with higher environmental suitability (indicated by niche model). Thus, in the future, the municipalities harvesting H. speciosa will produce less because there will be less suitable habitat for H. speciosa, which in turn will affect the H. speciosa harvest and the local economy.
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Evangelista, P.H.; Kumar, S.; Stohlgren, T.J.; Young, N.E.
2011-01-01
The aim of our study was to estimate forest vulnerability and potential distribution of three bark beetles (Curculionidae: Scolytinae) under current and projected climate conditions for 2020 and 2050. Our study focused on the mountain pine beetle (Dendroctonus ponderosae), western pine beetle (Dendroctonus brevicomis), and pine engraver (Ips pini). This study was conducted across eight states in the Interior West of the US covering approximately 2.2millionkm2 and encompassing about 95% of the Rocky Mountains in the contiguous US. Our analyses relied on aerial surveys of bark beetle outbreaks that occurred between 1991 and 2008. Occurrence points for each species were generated within polygons created from the aerial surveys. Current and projected climate scenarios were acquired from the WorldClim database and represented by 19 bioclimatic variables. We used Maxent modeling technique fit with occurrence points and current climate data to model potential beetle distributions and forest vulnerability. Three available climate models, each having two emission scenarios, were modeled independently and results averaged to produce two predictions for 2020 and two predictions for 2050 for each analysis. Environmental parameters defined by current climate models were then used to predict conditions under future climate scenarios, and changes in different species' ranges were calculated. Our results suggested that the potential distribution for bark beetles under current climate conditions is extensive, which coincides with infestation trends observed in the last decade. Our results predicted that suitable habitats for the mountain pine beetle and pine engraver beetle will stabilize or decrease under future climate conditions, while habitat for the western pine beetle will continue to increase over time. The greatest increase in habitat area was for the western pine beetle, where one climate model predicted a 27% increase by 2050. In contrast, the predicted habitat of the mountain pine beetle from another climate model suggested a decrease in habitat areas as great as 46% by 2050. Generally, 2020 and 2050 models that tested the three climate scenarios independently had similar trends, though one climate scenario for the western pine beetle produced contrasting results. Ranges for all three species of bark beetles shifted considerably geographically suggesting that some host species may become more vulnerable to beetle attack in the future, while others may have a reduced risk over time. ?? 2011 Elsevier B.V.
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McDowell, W.G.; Benson, A.J.; Byers, J.E.
2014-01-01
1. Two dominant drivers of species distributions are climate and habitat, both of which are changing rapidly. Understanding the relative importance of variables that can control distributions is critical, especially for invasive species that may spread rapidly and have strong effects on ecosystems. 2. Here, we examine the relative importance of climate and habitat variables in controlling the distribution of the widespread invasive freshwater clam Corbicula fluminea, and we model its future distribution under a suite of climate scenarios using logistic regression and maximum entropy modelling (MaxEnt). 3. Logistic regression identified climate variables as more important than habitat variables in controlling Corbicula distribution. MaxEnt modelling predicted Corbicula's range expansion westward and northward to occupy half of the contiguous United States. By 2080, Corbicula's potential range will expand 25–32%, with more than half of the continental United States being climatically suitable. 4. Our combination of multiple approaches has revealed the importance of climate over habitat in controlling Corbicula's distribution and validates the climate-only MaxEnt model, which can readily examine the consequences of future climate projections. 5. Given the strong influence of climate variables on Corbicula's distribution, as well as Corbicula's ability to disperse quickly and over long distances, Corbicula is poised to expand into New England and the northern Midwest of the United States. Thus, the direct effects of climate change will probably be compounded by the addition of Corbicula and its own influences on ecosystem function.
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NASA Astrophysics Data System (ADS)
Collados-Lara, Antonio-Juan; Pulido-Velazquez, David; Pardo-Iguzquiza, Eulogio
2017-04-01
Assessing impacts of potential future climate change scenarios in precipitation and temperature is essential to design adaptive strategies in water resources systems. The objective of this work is to analyze the possibilities of different statistical downscaling methods to generate future potential scenarios in an Alpine Catchment from historical data and the available climate models simulations performed in the frame of the CORDEX EU project. The initial information employed to define these downscaling approaches are the historical climatic data (taken from the Spain02 project for the period 1971-2000 with a spatial resolution of 12.5 Km) and the future series provided by climatic models in the horizon period 2071-2100 . We have used information coming from nine climate model simulations (obtained from five different Regional climate models (RCM) nested to four different Global Climate Models (GCM)) from the European CORDEX project. In our application we have focused on the Representative Concentration Pathways (RCP) 8.5 emissions scenario, which is the most unfavorable scenario considered in the fifth Assessment Report (AR5) by the Intergovernmental Panel on Climate Change (IPCC). For each RCM we have generated future climate series for the period 2071-2100 by applying two different approaches, bias correction and delta change, and five different transformation techniques (first moment correction, first and second moment correction, regression functions, quantile mapping using distribution derived transformation and quantile mapping using empirical quantiles) for both of them. Ensembles of the obtained series were proposed to obtain more representative potential future climate scenarios to be employed to study potential impacts. In this work we propose a non-equifeaseble combination of the future series giving more weight to those coming from models (delta change approaches) or combination of models and techniques that provides better approximation to the basic and drought statistic of the historical data. A multi-objective analysis using basic statistics (mean, standard deviation and asymmetry coefficient) and droughts statistics (duration, magnitude and intensity) has been performed to identify which models are better in terms of goodness of fit to reproduce the historical series. The drought statistics have been obtained from the Standard Precipitation index (SPI) series using the Theory of Runs. This analysis allows discriminate the best RCM and the best combination of model and correction technique in the bias-correction method. We have also analyzed the possibilities of using different Stochastic Weather Generators to approximate the basic and droughts statistics of the historical series. These analyses have been performed in our case study in a lumped and in a distributed way in order to assess its sensibility to the spatial scale. The statistic of the future temperature series obtained with different ensemble options are quite homogeneous, but the precipitation shows a higher sensibility to the adopted method and spatial scale. The global increment in the mean temperature values are 31.79 %, 31.79 %, 31.03 % and 31.74 % for the distributed bias-correction, distributed delta-change, lumped bias-correction and lumped delta-change ensembles respectively and in the precipitation they are -25.48 %, -28.49 %, -26.42 % and -27.35% respectively. Acknowledgments: This research work has been partially supported by the GESINHIMPADAPT project (CGL2013-48424-C2-2-R) with Spanish MINECO funds. We would also like to thank Spain02 and CORDEX projects for the data provided for this study and the R package qmap.
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Higher order statistical moment application for solar PV potential analysis
NASA Astrophysics Data System (ADS)
Basri, Mohd Juhari Mat; Abdullah, Samizee; Azrulhisham, Engku Ahmad; Harun, Khairulezuan
2016-10-01
Solar photovoltaic energy could be as alternative energy to fossil fuel, which is depleting and posing a global warming problem. However, this renewable energy is so variable and intermittent to be relied on. Therefore the knowledge of energy potential is very important for any site to build this solar photovoltaic power generation system. Here, the application of higher order statistical moment model is being analyzed using data collected from 5MW grid-connected photovoltaic system. Due to the dynamic changes of skewness and kurtosis of AC power and solar irradiance distributions of the solar farm, Pearson system where the probability distribution is calculated by matching their theoretical moments with that of the empirical moments of a distribution could be suitable for this purpose. On the advantage of the Pearson system in MATLAB, a software programming has been developed to help in data processing for distribution fitting and potential analysis for future projection of amount of AC power and solar irradiance availability.
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NASA Technical Reports Server (NTRS)
Burby, R. J.; Kuhlman, W. H.
1978-01-01
Book 2 of this volume is divided into the following sections: (1) commodities and system networks; (2) future mode choice decisions and commodity air eligibility; (3) comparative cargo transportation costs - air, truck, rail and water; (4) elasticities of demand; (5) operating cost; (6) operating profit, rate making, and returns; (7) importance of rate and service on future aircraft; (8) potential market demand for new aircraft; (9) scenario of events affecting system/market growth; and (10) future study and technology requirements.
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Motion/imagery secure cloud enterprise architecture analysis
NASA Astrophysics Data System (ADS)
DeLay, John L.
2012-06-01
Cloud computing with storage virtualization and new service-oriented architectures brings a new perspective to the aspect of a distributed motion imagery and persistent surveillance enterprise. Our existing research is focused mainly on content management, distributed analytics, WAN distributed cloud networking performance issues of cloud based technologies. The potential of leveraging cloud based technologies for hosting motion imagery, imagery and analytics workflows for DOD and security applications is relatively unexplored. This paper will examine technologies for managing, storing, processing and disseminating motion imagery and imagery within a distributed network environment. Finally, we propose areas for future research in the area of distributed cloud content management enterprises.
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NASA Astrophysics Data System (ADS)
Singer, Anja; Millat, Gerald; Staneva, Joanna; Kröncke, Ingrid
2017-03-01
Small-scale spatial distribution patterns of seven macrofauna species, seagrass beds and mixed mussel/oyster reefs were modelled for the Jade Bay (North Sea, Germany) in response to climatic and environmental scenarios (representing 2050). For the species distribution models four presence-absence modelling methods were merged within the ensemble forecasting platform 'biomod2'. The present spatial distribution (representing 2009) was modelled by statistically related species presences, true species absences and six high-resolution environmental grids. The future spatial distribution was then predicted in response to expected climate change-induced ongoing (1) sea-level rise and (2) water temperature increase. Between 2009 and 2050, the present and future prediction maps revealed a significant range gain for two macrofauna species (Macoma balthica, Tubificoides benedii), whereas the species' range sizes of five macrofauna species remained relatively stable across space and time. The predicted probability of occurrence (PO) of two macrofauna species (Cerastoderma edule, Scoloplos armiger) decreased significantly under the potential future habitat conditions. In addition, a clear seagrass bed extension (Zostera noltii) on the lower intertidal flats (mixed sediments) and a decrease in the PO of mixed Mytilus edulis/Crassostrea gigas reefs was predicted for 2050. Until the mid-21st century, our future climatic and environmental scenario revealed significant changes in the range sizes (gains-losses) and/or the PO (increases-decreases) for seven of the 10 modelled species at the study site.
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Kalvelage, T.; Willems, Jennifer
2003-01-01
The design of the EOS Data and Information Systems (EOSDIS) to acquire, archive, manage and distribute Earth observation data to the broadest possible user community was discussed. A number of several integrated retrieval, processing and distribution capabilities have been explained. The value of these functions to the users were described and potential future improvements were laid out for the users. The users were interested in acquiring the retrieval, processing and archiving systems integrated so that they can get the data they want in the format and delivery mechanism of their choice.
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Daszak, Peter; Zambrana-Torrelio, Carlos; Bogich, Tiffany L; Fernandez, Miguel; Epstein, Jonathan H; Murray, Kris A; Hamilton, Healy
2013-02-26
Emerging infectious diseases (EIDs) pose a significant threat to human health, economic stability, and biodiversity. Despite this, the mechanisms underlying disease emergence are still not fully understood, and control measures rely heavily on mitigating the impact of EIDs after they have emerged. Here, we highlight the emergence of a zoonotic Henipavirus, Nipah virus, to demonstrate the interdisciplinary and macroecological approaches necessary to understand EID emergence. Previous work suggests that Nipah virus emerged due to the interaction of the wildlife reservoir (Pteropus spp. fruit bats) with intensively managed livestock. The emergence of this and other henipaviruses involves interactions among a suite of anthropogenic environmental changes, socioeconomic factors, and changes in demography that overlay and interact with the distribution of these pathogens in their wildlife reservoirs. Here, we demonstrate how ecological niche modeling may be used to investigate the potential role of a changing climate on the future risk for Henipavirus emergence. We show that the distribution of Henipavirus reservoirs, and therefore henipaviruses, will likely change under climate change scenarios, a fundamental precondition for disease emergence in humans. We assess the variation among climate models to estimate where Henipavirus host distribution is most likely to expand, contract, or remain stable, presenting new risks for human health. We conclude that there is substantial potential to use this modeling framework to explore the distribution of wildlife hosts under a changing climate. These approaches may directly inform current and future management and surveillance strategies aiming to improve pathogen detection and, ultimately, reduce emergence risk.
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Sahlean, Tiberiu C; Gherghel, Iulian; Papeş, Monica; Strugariu, Alexandru; Zamfirescu, Ştefan R
2014-01-01
Climate warming is one of the most important threats to biodiversity. Ectothermic organisms such as amphibians and reptiles are especially vulnerable as climatic conditions affect them directly. Ecological niche models (ENMs) are increasingly popular in ecological studies, but several drawbacks exist, including the limited ability to account for the dispersal potential of the species. In this study, we use ENMs to explore the impact of global climate change on the Caspian whip snake (Dolichophis caspius) as model for organisms with low dispersal abilities and to quantify dispersal to novel areas using GIS techniques. Models generated using Maxent 3.3.3 k and GARP for current distribution were projected on future climatic scenarios. A cost-distance analysis was run in ArcGIS 10 using geomorphological features, ecological conditions, and human footprint as "costs" to dispersal of the species to obtain a Maximum Dispersal Range (MDR) estimate. All models developed were statistically significant (P<0.05) and recovered the currently known distribution of D. caspius. Models projected on future climatic conditions using Maxent predicted a doubling of suitable climatic area, while GARP predicted a more conservative expansion. Both models agreed on an expansion of suitable area northwards, with minor decreases at the southern distribution limit. The MDR area calculated using the Maxent model represented a third of the total area of the projected model. The MDR based on GARP models recovered only about 20% of the total area of the projected model. Thus, incorporating measures of species' dispersal abilities greatly reduced estimated area of potential future distributions.
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Climatically-mediated landcover change: impacts on Brazilian territory.
Zanin, Marina; Tessarolo, Geiziane; Machado, Nathália; Albernaz, Ana Luisa M
2017-01-01
In the face of climate change threats, governments are drawing attention to policies for mitigating its effects on biodiversity. However, the lack of distribution data makes predictions at species level a difficult task, mainly in regions of higher biodiversity. To overcome this problem, we use native landcover as a surrogate biodiversity, because it can represent specialized habitat for species, and investigate the effects of future climate change on Brazilian biomes. We characterize the climatic niches of native landcover and use ecological niche modeling to predict the potential distribution under current and future climate scenarios. Our results highlight expansion of the distribution of open vegetation and the contraction of closed forests. Drier Brazilian biomes, like Caatinga and Cerrado, are predicted to expand their distributions, being the most resistant to climate change impacts. However, these would also be affected by losses of their closed forest enclaves and their habitat-specific or endemic species. Replacement by open vegetation and overall reductions are a considerable risk for closed forest, threatening Amazon and Atlantic forest biomes. Here, we evidence the impacts of climate change on Brazilian biomes, and draw attention to the necessity for management and attenuation plans to guarantee the future of Brazilian biodiversity.
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Thomas, Evert; Tovar, Eduardo; Villafañe, Carolina; Bocanegra, José Leonardo; Moreno, Rodrigo
2017-12-01
Crop wild relatives (CWRs) of rice hold important traits that can contribute to enhancing the ability of cultivated rice (Oryza sativa and O. glaberrima) to produce higher yields, cope with the effects of climate change, and resist attacks of pests and diseases, among others. However, the genetic resources of these species remain dramatically understudied, putting at risk their future availability from in situ and ex situ sources. Here we assess the distribution of genetic diversity of the four rice CWRs known to occur in Colombia (O. glumaepatula, O. alta, O. grandiglumis, and O. latifolia). Furthermore, we estimated the degree of overlap between areas with suitable habitat for cultivated and wild rice, both under current and predicted future climate conditions to assess the potential spatiotemporal scale of potential gene flow from GM rice to its CWRs. Our findings suggest that part of the observed genetic diversity and structure, at least of the most exhaustively sampled species, may be explained by their glacial and post-glacial range dynamics. Furthermore, in assessing the expected impact of climate change and the potential spatiotemporal scale of gene flow between populations of CWRs and GM rice we find significant overlap between present and future suitable areas for cultivated rice and its four CWRs. Climate change is expected to have relatively limited negative effects on the rice CWRs, with three species showing opportunities to expand their distribution ranges in the future. Given (i) the sparse presence of CWR populations in protected areas (ii) the strong suitability overlap between cultivated rice and its four CWRs; and (iii) the complexity of managing and regulating areas to prevent alien gene flow, the first priority should be to establish representative ex situ collections for all CWR species, which currently do not exist. In the absence of studies under field conditions on the scale and extent of gene flow between cultivated rice and its Colombian CWRs, effective in situ conservation might best be achieved through tailor-made management plans and exclusion of GM rice cultivation in areas holding the most genetically diverse CWR populations. This may be combined with assisted migration of populations to suitable areas where rice is unlikely to be cultivated under current and future climate conditions.
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Martínez Meyer, Enrique; Sánchez-Velásquez, Lázaro R.
2016-01-01
Climate change is recognized as an important threat to global biodiversity because it increases the risk of extinction of many species on the planet. Mexico is a megadiverse country and native tree species such as red cedar (Cedrela odorata) can be used to maintain forests while helping mitigate climate change, because it is considered a fast growing pioneer species with great economic potential in the forestry industry. In order to assess possible shifts in areas suitable for C. odorata plantations in Mexico with ecological niche models, we used the MaxLike algorithm, climate variables, the geo-referenced records of this species, three general circulation models and three scenarios of future emissions. Results show a current potential distribution of 573,079 km2 with an average probability of occurrence of 0.93 (± 0.13). The potential distribution area could increase up to 650,356 km2 by 2060 according to the general circulation model HADCM3 B2, with an average probability of occurrence of 0.86 (± 0.14). Finally, we delimited an area of 35,377 km2 that has a high potential for the establishment of C. odorata plantations, by selecting those sites with optimal conditions for its growth that are outside protected areas and are currently devoid of trees. C. odorata has a significant potential to help in the mitigation of the effects of climate change. Using MaxLike we identified extense areas in Mexico suitable to increase carbon sequestration through plantations of this highly valued native tree species. PMID:27732622
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Estrada-Contreras, Israel; Equihua, Miguel; Laborde, Javier; Martínez Meyer, Enrique; Sánchez-Velásquez, Lázaro R
2016-01-01
Climate change is recognized as an important threat to global biodiversity because it increases the risk of extinction of many species on the planet. Mexico is a megadiverse country and native tree species such as red cedar (Cedrela odorata) can be used to maintain forests while helping mitigate climate change, because it is considered a fast growing pioneer species with great economic potential in the forestry industry. In order to assess possible shifts in areas suitable for C. odorata plantations in Mexico with ecological niche models, we used the MaxLike algorithm, climate variables, the geo-referenced records of this species, three general circulation models and three scenarios of future emissions. Results show a current potential distribution of 573,079 km2 with an average probability of occurrence of 0.93 (± 0.13). The potential distribution area could increase up to 650,356 km2 by 2060 according to the general circulation model HADCM3 B2, with an average probability of occurrence of 0.86 (± 0.14). Finally, we delimited an area of 35,377 km2 that has a high potential for the establishment of C. odorata plantations, by selecting those sites with optimal conditions for its growth that are outside protected areas and are currently devoid of trees. C. odorata has a significant potential to help in the mitigation of the effects of climate change. Using MaxLike we identified extense areas in Mexico suitable to increase carbon sequestration through plantations of this highly valued native tree species.
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Springer, Yuri P.; Jarnevich, Catherine S.; Barnett, David T.; Monaghan, Andrew J.; Eisen, Rebecca J.
2015-01-01
The Lone star tick (Amblyomma americanum L.) is the primary vector for pathogens of significant public health importance in North America, yet relatively little is known about its current and potential future distribution. Building on a published summary of tick collection records, we used an ensemble modeling approach to predict the present-day and future distribution of climatically suitable habitat for establishment of the Lone star tick within the continental United States. Of the nine climatic predictor variables included in our five present-day models, average vapor pressure in July was by far the most important determinant of suitable habitat. The present-day ensemble model predicted an essentially contiguous distribution of suitable habitat extending to the Atlantic coast east of the 100th western meridian and south of the 40th northern parallel, but excluding a high elevation region associated with the Appalachian Mountains. Future ensemble predictions for 2061–2080 forecasted a stable western range limit, northward expansion of suitable habitat into the Upper Midwest and western Pennsylvania, and range contraction along portions of the Gulf coast and the lower Mississippi river valley. These findings are informative for raising awareness of A. americanum-transmitted pathogens in areas where the Lone Star tick has recently or may become established.
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Sen, Sandeep; Gode, Ameya; Ramanujam, Srirama; Ravikanth, G; Aravind, N A
2016-11-01
The center of diversity of Piper nigrum L. (Black Pepper), one of the highly valued spice crops is reported to be from India. Black pepper is naturally distributed in India in the Western Ghats biodiversity hotspot and is the only known existing source of its wild germplasm in the world. We used ecological niche models to predict the potential distribution of wild P. nigrum in the present and two future climate change scenarios viz (A1B) and (A2A) for the year 2080. Three topographic and nine uncorrelated bioclim variables were used to develop the niche models. The environmental variables influencing the distribution of wild P. nigrum across different climate change scenarios were identified. We also assessed the direction and magnitude of the niche centroid shift and the change in niche breadth to estimate the impact of projected climate change on the distribution of P. nigrum. The study shows a niche centroid shift in the future climate scenarios. Both the projected future climate scenarios predicted a reduction in the habitat of P. nigrum in Southern Western Ghats, which harbors many wild accessions of P. nigrum. Our results highlight the impact of future climate change on P. nigrum and provide useful information for designing sound germplasm conservation strategies for P. nigrum.
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Hodd, Rory L; Bourke, David; Skeffington, Micheline Sheehy
2014-01-01
Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the north-west hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1) oceanic montane bryophytes and vascular plants; 2) species belonging to different montane plant communities; 3) species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need significantly greater focus on potential climate change impacts, including models with higher-resolution species distribution and environmental data, to aid these communities' long-term survival.
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Skeffington, Micheline Sheehy
2014-01-01
Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the north-west hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1) oceanic montane bryophytes and vascular plants; 2) species belonging to different montane plant communities; 3) species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need significantly greater focus on potential climate change impacts, including models with higher-resolution species distribution and environmental data, to aid these communities' long-term survival. PMID:24752011
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Khadioli, N; Tonnang, Z E H; Muchugu, E; Ong'amo, G; Achia, T; Kipchirchir, I; Kroschel, J; Le Ru, B
2014-12-01
Maize (Zea mays) is a major staple food in Africa. However, maize production is severely reduced by damage caused by feeding lepidopteran pests. In East and Southern Africa, Chilo partellus is one of the most damaging cereal stem borers mainly found in the warmer lowland areas. In this study, it was hypothesized that the future distribution and abundance of C. partellus may be affected greatly by the current global warming. The temperature-dependent population growth potential of C. partellus was studied on artificial diet under laboratory conditions at six constant temperatures (15, 18, 20, 25, 28, 30, 32 and 35 °C), relative humidity of 75±5% and a photoperiod of L12:L12 h. Several non-linear models were fitted to the data to model development time, mortality and reproduction of the insect species. Cohort updating algorithm and rate summation approach were stochastically used for simulating age and stage structure populations and generate life-table parameters. For spatial analysis of the pest risk, three generic risk indices (index of establishment, generation number and activity index) were visualized in the geographical information system component of the advanced Insect Life Cycle modeling (ILCYM) software. To predict the future distribution of C. partellus we used the climate change scenario A1B obtained from WorldClim and CCAFS databases. The maps were compared with available data on the current distribution of C. partellus in Kenya. The results show that the development times of the different stages decreased with increasing temperatures ranging from 18 to 35 °C; at the extreme temperatures, 15 and 38 °C, no egg could hatch and no larvae completed development. The study concludes that C. partellus may potentially expands its range into higher altitude areas, highland tropics and moist transitional regions, with the highest maize potential where the species has not been recorded yet. This has serious implication in terms of food security since these areas produce approximately 80% of the total maize in East Africa.
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Assessing the Future of Distributed Wind: Opportunities for Behind-the-Meter Projects
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lantz, Eric; Sigrin, Benjamin; Gleason, Michael
2016-11-01
Wind power is one of the fastest growing sources of new electricity generation in the United States. Cumulative installed capacity was more than 74,000 megawatts (MW) at year-end 2015 and wind power supplied 4.7% of total 2015 U.S. electricity generation. Despite the growth of the wind power industry, the distributed wind market has remained limited. Cumulative installations of distributed wind through 2015 totaled 934 MW. This first-of-a-kind exploratory analysis characterizes the future opportunity for behind-the-meter distributed wind, serving primarily rural or suburban homes, farms, and manufacturing facilities. This work focuses only on the grid-connected, behind-the-meter subset of the broader distributedmore » wind market. We estimate this segment to be approximately half of the 934 MW of total installed distributed wind capacity at year-end 2015. Potential from other distributed wind market segments including systems installed in front of the meter (e.g., community wind) and in remote, off-grid locations is not assessed in this analysis and therefore, would be additive to results presented here. These other distributed wind market segments are not considered in this initial effort because of their relatively unique economic and market attributes.« less
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Computer modeling of inversion layer MOS solar cells and arrays
NASA Technical Reports Server (NTRS)
Ho, Fat Duen
1991-01-01
A two dimensional numerical model of the inversion layer metal insulator semiconductor (IL/MIS) solar cell is proposed by using the finite element method. The two-dimensional current flow in the device is taken into account in this model. The electrostatic potential distribution, the electron concentration distribution, and the hole concentration distribution for different terminal voltages are simulated. The results of simple calculation are presented. The existing problems for this model are addressed. Future work is proposed. The MIS structures are studied and some of the results are reported.
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Monitoring Distributed Real-Time Systems: A Survey and Future Directions
NASA Technical Reports Server (NTRS)
Goodloe, Alwyn E.; Pike, Lee
2010-01-01
Runtime monitors have been proposed as a means to increase the reliability of safety-critical systems. In particular, this report addresses runtime monitors for distributed hard real-time systems. This class of systems has had little attention from the monitoring community. The need for monitors is shown by discussing examples of avionic systems failure. We survey related work in the field of runtime monitoring. Several potential monitoring architectures for distributed real-time systems are presented along with a discussion of how they might be used to monitor properties of interest.
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Watermeyer, Katherine E; Hutchings, Laurence; Jarre, Astrid; Shannon, Lynne J
2016-01-01
Several commercially and ecologically important species in the southern Benguela have undergone southward and eastward shifts in their distributions over previous decades, most notably the small pelagic fish sardine Sardinops sagax and anchovy Engraulis encrasicolus. Understanding these changes and their implications is essential in implementing an ecosystem approach to fisheries in the southern Benguela and attempting to appreciate the potential impacts of future environmental change. To investigate possible impacts of these shifts at an ecosystem level, distribution maps for before (1985-1991), during (1997-2000) and after (2003-2008) the shift in small pelagic fish were constructed for 14 key species from catch and survey data, and used to calculate spatial indicators including proportion east and west of Cape Agulhas, relative overlap in biomass and area, index of diversity, connectivity. Potential interactions on the south and west coasts were also compared. For several species (redeye; chub mackerel; kingklip; chokka squid; yellowtail), previously unidentified increases in the proportion of biomass east of Cape Agulhas were shown to have occurred over the same period as that of small pelagic fish, although none to the same degree. On average, overlap with small pelagic fish increased over time and overall system connectivity was lowest in the intermediate period, possibly indicating a system under transition. Connectivity declined over time on the west coast while increasing on the east coast. Distributions of other species have changed over time, with the region east of Cape Agulhas becoming increasingly important in terms of potential trophic interaction. Variations in distribution of biomass and structural complexity affect the trophic structure and hence functioning of the system, and implications should be considered when attempting to identify the possible ecosystem impacts of current and future system-level change.
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Holt, Ashley C; Salkeld, Daniel J; Fritz, Curtis L; Tucker, James R; Gong, Peng
2009-01-01
Background Plague, caused by the bacterium Yersinia pestis, is a public and wildlife health concern in California and the western United States. This study explores the spatial characteristics of positive plague samples in California and tests Maxent, a machine-learning method that can be used to develop niche-based models from presence-only data, for mapping the potential distribution of plague foci. Maxent models were constructed using geocoded seroprevalence data from surveillance of California ground squirrels (Spermophilus beecheyi) as case points and Worldclim bioclimatic data as predictor variables, and compared and validated using area under the receiver operating curve (AUC) statistics. Additionally, model results were compared to locations of positive and negative coyote (Canis latrans) samples, in order to determine the correlation between Maxent model predictions and areas of plague risk as determined via wild carnivore surveillance. Results Models of plague activity in California ground squirrels, based on recent climate conditions, accurately identified case locations (AUC of 0.913 to 0.948) and were significantly correlated with coyote samples. The final models were used to identify potential plague risk areas based on an ensemble of six future climate scenarios. These models suggest that by 2050, climate conditions may reduce plague risk in the southern parts of California and increase risk along the northern coast and Sierras. Conclusion Because different modeling approaches can yield substantially different results, care should be taken when interpreting future model predictions. Nonetheless, niche modeling can be a useful tool for exploring and mapping the potential response of plague activity to climate change. The final models in this study were used to identify potential plague risk areas based on an ensemble of six future climate scenarios, which can help public managers decide where to allocate surveillance resources. In addition, Maxent model results were significantly correlated with coyote samples, indicating that carnivore surveillance programs will continue to be important for tracking the response of plague to future climate conditions. PMID:19558717
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NASA Astrophysics Data System (ADS)
Rogers, B. M.; Jantz, P.; Goetz, S. J.
2015-12-01
Models of vegetation distributions are used for a wide variety of purposes, from global assessments of biome shifts and biogeochemical feedbacks to local management planning. Dynamic vegetation models, mostly mechanistic in origin, are valuable for regional to global studies but remain limited for more local-scale applications, especially those that require species-specific responses to climate change. Species distribution models (SDMs) are broadly used for such applications, but these too have several outstanding limitations, one of the most prominent being a lack of dispersal and migration. Several hybrid models have recently been developed, but these generally require detailed parameterization of species-level attributes that may not be known. Here we present an approach to couple migration potential with SDM output for a large number of species in order to more realistically project future range shifts. We focus on 40 tree species in the eastern US of potential management concern, either because of their canopy dominance, ecosystem functions, or potential for utilizing future climates. Future climates were taken from a CMIP5 model ensemble average using RCP 4.5 and 8.5 scenarios. We used Random Forests to characterize current and future environmental suitability, and modeled migration as a negative exponential kernel that is affected by forest fragmentation and the density of current seed sources. We present results in a vulnerability framework relevant for a number of ongoing management activities in the region. We find an overarching pattern of northward and eastward range shifts, with high-elevation and northern species being the most adversely impacted. Because of limitations to migration, many newly suitable areas could not be utilized without active intervention. Only a few areas exhibited consistently favorable conditions that could be utilized by the relevant species, including the central Appalachian foothills and the Florida panhandle. We suggest that a continued effort to include migration potential into vegetation models can lead to more realistic results and management-relevant products.
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Combining a Spatial Model and Demand Forecasts to Map Future Surface Coal Mining in Appalachia
Strager, Michael P.; Strager, Jacquelyn M.; Evans, Jeffrey S.; Dunscomb, Judy K.; Kreps, Brad J.; Maxwell, Aaron E.
2015-01-01
Predicting the locations of future surface coal mining in Appalachia is challenging for a number of reasons. Economic and regulatory factors impact the coal mining industry and forecasts of future coal production do not specifically predict changes in location of future coal production. With the potential environmental impacts from surface coal mining, prediction of the location of future activity would be valuable to decision makers. The goal of this study was to provide a method for predicting future surface coal mining extents under changing economic and regulatory forecasts through the year 2035. This was accomplished by integrating a spatial model with production demand forecasts to predict (1 km2) gridded cell size land cover change. Combining these two inputs was possible with a ratio which linked coal extraction quantities to a unit area extent. The result was a spatial distribution of probabilities allocated over forecasted demand for the Appalachian region including northern, central, southern, and eastern Illinois coal regions. The results can be used to better plan for land use alterations and potential cumulative impacts. PMID:26090883
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Khormi, Hassan M; Kumar, Lalit
2016-11-21
We used the Model for Interdisciplinary Research on Climate-H climate model with the A2 Special Report on Emissions Scenarios for the years 2050 and 2100 and CLIMEX software for projections to illustrate the potential impact of climate change on the spatial distributions of malaria in China, India, Indochina, Indonesia, and The Philippines based on climate variables such as temperature, moisture, heat, cold and dryness. The model was calibrated using data from several knowledge domains, including geographical distribution records. The areas in which malaria has currently been detected are consistent with those showing high values of the ecoclimatic index in the CLIMEX model. The match between prediction and reality was found to be high. More than 90% of the observed malaria distribution points were associated with the currently known suitable climate conditions. Climate suitability for malaria is projected to decrease in India, southern Myanmar, southern Thailand, eastern Borneo, and the region bordering Cambodia, Malaysia and the Indonesian islands, while it is expected to increase in southern and south-eastern China and Taiwan. The climatic models for Anopheles mosquitoes presented here should be useful for malaria control, monitoring, and management, particularly considering these future climate scenarios.
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Schwalm, Donelle; Epps, Clinton W; Rodhouse, Thomas J; Monahan, William B; Castillo, Jessica A; Ray, Chris; Jeffress, Mackenzie R
2016-04-01
Ecological niche theory holds that species distributions are shaped by a large and complex suite of interacting factors. Species distribution models (SDMs) are increasingly used to describe species' niches and predict the effects of future environmental change, including climate change. Currently, SDMs often fail to capture the complexity of species' niches, resulting in predictions that are generally limited to climate-occupancy interactions. Here, we explore the potential impact of climate change on the American pika using a replicated place-based approach that incorporates climate, gene flow, habitat configuration, and microhabitat complexity into SDMs. Using contemporary presence-absence data from occupancy surveys, genetic data to infer connectivity between habitat patches, and 21 environmental niche variables, we built separate SDMs for pika populations inhabiting eight US National Park Service units representing the habitat and climatic breadth of the species across the western United States. We then predicted occurrence probability under current (1981-2010) and three future time periods (out to 2100). Occurrence probabilities and the relative importance of predictor variables varied widely among study areas, revealing important local-scale differences in the realized niche of the American pika. This variation resulted in diverse and - in some cases - highly divergent future potential occupancy patterns for pikas, ranging from complete extirpation in some study areas to stable occupancy patterns in others. Habitat composition and connectivity, which are rarely incorporated in SDM projections, were influential in predicting pika occupancy in all study areas and frequently outranked climate variables. Our findings illustrate the importance of a place-based approach to species distribution modeling that includes fine-scale factors when assessing current and future climate impacts on species' distributions, especially when predictions are intended to manage and conserve species of concern within individual protected areas. © 2015 John Wiley & Sons Ltd.
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NASA Astrophysics Data System (ADS)
Flint, L. E.; Flint, A. L.; Weiss, S. B.; Micheli, E. R.
2010-12-01
In the face of rapid climate change, fine-scale predictions of landscape change are of extreme interest to land managers that endeavor to develop long term adaptive strategies for maintaining biodiversity and ecosystem services. Global climate model (GCM) outputs, which generally focus on estimated increases in air temperature, are increasingly applied to species habitat distribution models. For sensitive species subject to climate change, habitat models predict significant migration (either northward or towards higher elevations), or complete extinction. Current studies typically rely on large spatial scale GCM projections (> 10 km) of changes in precipitation and air temperature: at this scale, these models necessarily neglect subtleties of topographic shading, geomorphic expression of the landscape, and fine-scale differences in soil properties - data that is readily available at meaningful local scales. Recent advances in modeling take advantage of available soils, geology, and topographic data to construct watershed-scale scenarios using GCM inputs and result in improved correlations of vegetation distribution with temperature. For this study, future climate projections were downscaled to 270-m and applied to a physically-based hydrologic model to calculate future changes in recharge, runoff, and climatic water deficit (CWD) for basins draining into the northern San Francisco Bay. CWD was analyzed for mapped vegetation types to evaluate the range of CWD for historic time periods in comparison to future time periods. For several forest communities (including blue oak woodlands, montane hardwoods, douglas-fir, and coast redwood) existing landscape area exhibiting suitable CWD diminishes by up 80 percent in the next century, with a trend towards increased CWD throughout the region. However, no forest community loses all suitable habitat, with islands of potential habitat primarily remaining on north facing slopes and deeper soils. Creation of new suitable habitat is also predicted throughout the region. Results have direct application to management issues of habitat connectivity, forest land protection and acquisition, and active management solutions such as transplanting or assisted migration. Although this analysis considers only one driver of forest habitat distribution, consideration of hydrologic derivatives at a fine scale explains current forest community distributions and provides a far more informed perspective on potential future forest distributions. Results demonstrate the utility of fine-scale modeling and provide landscape managers and conservation agencies valuable management tools in fine-scale future forest scenarios and a framework for evaluating forest resiliency in a changing climate.
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The Effect of Oxidant and Redox Potential on Metal Corrosion in Drinking Water
Future drinking water regulatory action may require some water utilities to consider additional and/or alternative oxidation and disinfection practices. There is little known about the effect of oxidant changes on the corrosion of drinking water distribution system materials and ...
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Global Change and the Function and Distribution of Wetlands
Middleton, Beth A.
2012-01-01
The Global Change Ecology and Wetlands book series will highlight the latest research from the world leaders in the field of climate change in wetlands. Global Change and the Function and Distribution of Wetlands highlights information of importance to wetland ecologists. The chapters include syntheses of international studies on the effects of drought on function and regeneration in wetlands, sea level rise and the distribution of mangrove swamps, former distributions of swamp species and future lessons from paleoecology, and shifts in atmospheric emissions across geographical regions in wetlands. Overall, the book will contribute to a better understanding of the potential effects of climate change on world wetland distribution and function.
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NASA Technical Reports Server (NTRS)
Andrews, Arlyn; Kawa, Randy; Zhu, Zhengxin; Burris, John; Abshire, Jim
2004-01-01
A detailed mechanistic understanding of the sources and sinks of CO2 will be required to reliably predict future CO2 levels and climate. A commonly used technique for deriving information about CO2 exchange with surface reservoirs is to solve an 'inverse problem', where CO2 observations are used with an atmospheric transport model to find the optimal distribution of sources and sinks. Synthesis inversion methods are powerful tools for addressing this question, but the results are disturbingly sensitive to the details of the calculation. Studies done using different atmospheric transport models and combinations of surface station data have produced substantially different distributions of surface fluxes. Adjoint methods are now being developed that will more effectively incorporate diverse datasets in estimates of surface fluxes of CO2. In an adjoint framework, it will be possible to combine CO2 concentration data from longterm surface and aircraft monitoring stations with data from intensive field campaigns and with proposed future satellite observations. We have recently developed an adjoint for the GSFC 3-D Parameterized Chemistry and Transport Model (PCTM). Here, we will present results from a PCTM Adjoint study comparing the sampling footprints of tall tower, aircraft and potential future lidar observations of CO2. The vertical resolution and extent of the profiles and the observation frequency will be considered for several sites in North America.
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Biodiversity funds and conservation needs in the EU under climate change
Lung, Tobias; Meller, Laura; van Teeffelen, Astrid J.A.; Thuiller, Wilfried; Cabeza, Mar
2014-01-01
Despite ambitious biodiversity policy goals, less than a fifth of the European Union’s (EU) legally protected species and habitats show a favorable conservation status. The recent EU biodiversity strategy recognizes that climate change adds to the challenge of halting biodiversity loss, and that an optimal distribution of financial resources is needed. Here, we analyze recent EU biodiversity funding from a climate change perspective. We compare the allocation of funds to the distribution of both current conservation priorities (within and beyond Natura 2000) and future conservation needs at the level of NUTS-2 regions, using modelled bird distributions as indicators of conservation value. We find that funding is reasonably well aligned with current conservation efforts but poorly fit with future needs under climate change, indicating obstacles for implementing adaptation measures. We suggest revising EU biodiversity funding instruments for the 2014-2020 budget period to better account for potential climate change impacts on biodiversity. PMID:25264456
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Biodiversity funds and conservation needs in the EU under climate change.
Lung, Tobias; Meller, Laura; van Teeffelen, Astrid J A; Thuiller, Wilfried; Cabeza, Mar
2014-07-01
Despite ambitious biodiversity policy goals, less than a fifth of the European Union's (EU) legally protected species and habitats show a favorable conservation status. The recent EU biodiversity strategy recognizes that climate change adds to the challenge of halting biodiversity loss, and that an optimal distribution of financial resources is needed. Here, we analyze recent EU biodiversity funding from a climate change perspective. We compare the allocation of funds to the distribution of both current conservation priorities (within and beyond Natura 2000) and future conservation needs at the level of NUTS-2 regions, using modelled bird distributions as indicators of conservation value. We find that funding is reasonably well aligned with current conservation efforts but poorly fit with future needs under climate change, indicating obstacles for implementing adaptation measures. We suggest revising EU biodiversity funding instruments for the 2014-2020 budget period to better account for potential climate change impacts on biodiversity.
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Short-Term State Forecasting-Based Optimal Voltage Regulation in Distribution Systems: Preprint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Rui; Jiang, Huaiguang; Zhang, Yingchen
2017-05-17
A novel short-term state forecasting-based optimal power flow (OPF) approach for distribution system voltage regulation is proposed in this paper. An extreme learning machine (ELM) based state forecaster is developed to accurately predict system states (voltage magnitudes and angles) in the near future. Based on the forecast system states, a dynamically weighted three-phase AC OPF problem is formulated to minimize the voltage violations with higher penalization on buses which are forecast to have higher voltage violations in the near future. By solving the proposed OPF problem, the controllable resources in the system are optimally coordinated to alleviate the potential severemore » voltage violations and improve the overall voltage profile. The proposed approach has been tested in a 12-bus distribution system and simulation results are presented to demonstrate the performance of the proposed approach.« less
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Global Pyrogeography: the Current and Future Distribution of Wildfire
Krawchuk, Meg A.; Moritz, Max A.; Parisien, Marc-André; Van Dorn, Jeff; Hayhoe, Katharine
2009-01-01
Climate change is expected to alter the geographic distribution of wildfire, a complex abiotic process that responds to a variety of spatial and environmental gradients. How future climate change may alter global wildfire activity, however, is still largely unknown. As a first step to quantifying potential change in global wildfire, we present a multivariate quantification of environmental drivers for the observed, current distribution of vegetation fires using statistical models of the relationship between fire activity and resources to burn, climate conditions, human influence, and lightning flash rates at a coarse spatiotemporal resolution (100 km, over one decade). We then demonstrate how these statistical models can be used to project future changes in global fire patterns, highlighting regional hotspots of change in fire probabilities under future climate conditions as simulated by a global climate model. Based on current conditions, our results illustrate how the availability of resources to burn and climate conditions conducive to combustion jointly determine why some parts of the world are fire-prone and others are fire-free. In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe. These changes could have important effects on terrestrial ecosystems since alteration in fire activity may occur quite rapidly, generating ever more complex environmental challenges for species dispersing and adjusting to new climate conditions. Our findings highlight the potential for widespread impacts of climate change on wildfire, suggesting severely altered fire regimes and the need for more explicit inclusion of fire in research on global vegetation-climate change dynamics and conservation planning. PMID:19352494
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Electro-optic measurement of terahertz pulse energy distribution.
Sun, J H; Gallacher, J G; Brussaard, G J H; Lemos, N; Issac, R; Huang, Z X; Dias, J M; Jaroszynski, D A
2009-11-01
An accurate and direct measurement of the energy distribution of a low repetition rate terahertz electromagnetic pulse is challenging because of the lack of sensitive detectors in this spectral range. In this paper, we show how the total energy and energy density distribution of a terahertz electromagnetic pulse can be determined by directly measuring the absolute electric field amplitude and beam energy density distribution using electro-optic detection. This method has potential use as a routine method of measuring the energy density of terahertz pulses that could be applied to evaluating future high power terahertz sources, terahertz imaging, and spatially and temporarily resolved pump-probe experiments.
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Performance Prediction and Validation: Data, Frameworks, and Considerations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tinnesand, Heidi
2017-05-19
Improving the predictability and reliability of wind power generation and operations will reduce costs and potentially establish a framework to attract new capital into the distributed wind sector, a key cost reduction requirement highlighted in results from the distributed wind future market assessment conducted with dWind. Quantifying and refining the accuracy of project performance estimates will also directly address several of the key challenges identified by industry stakeholders in 2015 as part of the distributed wind resource assessment workshop and be cross-cutting for several other facets of the distributed wind portfolio. This presentation covers the efforts undertaken in 2016 tomore » address these topics.« less
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Modeling Malaria Vector Distribution under Climate Change Scenarios in Kenya
NASA Astrophysics Data System (ADS)
Ngaina, J. N.
2017-12-01
Projecting the distribution of malaria vectors under climate change is essential for planning integrated vector control strategies for sustaining elimination and preventing reintroduction of malaria. However, in Kenya, little knowledge exists on the possible effects of climate change on malaria vectors. Here we assess the potential impact of future climate change on locally dominant Anopheles vectors including Anopheles gambiae, Anopheles arabiensis, Anopheles merus, Anopheles funestus, Anopheles pharoensis and Anopheles nili. Environmental data (Climate, Land cover and elevation) and primary empirical geo-located species-presence data were identified. The principle of maximum entropy (Maxent) was used to model the species' potential distribution area under paleoclimate, current and future climates. The Maxent model was highly accurate with a statistically significant AUC value. Simulation-based estimates suggest that the environmentally suitable area (ESA) for Anopheles gambiae, An. arabiensis, An. funestus and An. pharoensis would increase under all two scenarios for mid-century (2016-2045), but decrease for end century (2071-2100). An increase in ESA of An. Funestus was estimated under medium stabilizing (RCP4.5) and very heavy (RCP8.5) emission scenarios for mid-century. Our findings can be applied in various ways such as the identification of additional localities where Anopheles malaria vectors may already exist, but has not yet been detected and the recognition of localities where it is likely to spread to. Moreover, it will help guide future sampling location decisions, help with the planning of vector control suites nationally and encourage broader research inquiry into vector species niche modeling
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Kwon, Tae-Sung; Li, Fengqing; Kim, Sung-Soo; Chun, Jung Hwa; Park, Young-Seuk
2016-01-01
Global warming is likely leading to species' distributional shifts, resulting in changes in local community compositions and diversity patterns. In this study, we applied species distribution models to evaluate the potential impacts of temperature increase on ant communities in Korean temperate forests, by testing hypotheses that 1) the risk of extinction of forest ant species would increase over time, and 2) the changes in species distribution ranges could drive upward movements of ant communities and further alter patterns of species richness. We sampled ant communities at 335 evenly distributed sites across South Korea and modelled the future distribution range for each species using generalized additive models. To account for spatial autocorrelation, autocovariate regressions were conducted prior to generalized additive models. Among 29 common ant species, 12 species were estimated to shrink their suitable geographic areas, whereas five species would benefit from future global warming. Species richness was highest at low altitudes in the current period, and it was projected to be highest at the mid-altitudes in the 2080s, resulting in an upward movement of 4.9 m yr-1. This altered the altitudinal pattern of species richness from a monotonic-decrease curve (common in temperate regions) to a bell-shaped curve (common in tropical regions). Overall, ant communities in temperate forests are vulnerable to the on-going global warming and their altitudinal movements are similar to other faunal communities.
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Thomas, Kathryn A.; Guertin, Patricia P.; Gass, Leila
2012-01-01
The authors developed spatial models of the predicted modern-day suitable habitat (SH) of 166 dominant and indicator plant species of the southwestern United States (herein referred to as the Southwest) and then conducted a coarse assessment of potential future changes in the distribution of their suitable habitat under three climate-change scenarios for two time periods. We used Maxent-based spatial modeling to predict the modern-day and future scenarios of SH for each species in an over 342-million-acre area encompassing all or parts of six states in the Southwest--Arizona, California, Colorado, Nevada, New Mexico, and Utah. Modern-day SH models were predicted by our using 26 annual and monthly average temperature and precipitation variables, averaged for the years 1971-2000. Future SH models were predicted for each species by our using six climate models based on application of the average of 16 General Circulation Models to Intergovernmental Panel on Climate Change emission scenarios B1, A1B, and A2 for two time periods, 2040 to 2069 and 2070 and 2100, referred to respectively as the 2050 and 2100 time periods. The assessment examined each species' vulnerability to loss of modern-day SH under future climate scenarios, potential to gain SH under future climate scenarios, and each species' estimated risk as a function of both vulnerability and potential gains. All 166 species were predicted to lose modern-day SH in the future climate change scenarios. In the 2050 time period, nearly 30 percent of the species lost 75 percent or more of their modern-day suitable habitat, 21 species gained more new SH than their modern-day SH, and 30 species gained less new SH than 25 percent of their modern-day SH. In the 2100 time period, nearly half of the species lost 75 percent or more of their modern-day SH, 28 species gained more new SH than their modern-day SH, and 34 gained less new SH than 25 percent of their modern-day SH. Using nine risk categories we found only two species were in the least risk category, while 20 species were in the highest risk category. The assessment showed that species respond independently to predicted climate change, suggesting that current plant assemblages may disassemble under predicted climate change scenarios. This report presents the results for each species in tables (Appendix A) and maps (14 for each species) in Appendix B.
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Guo, Yanlong; Li, Xin; Zhao, Zefang; Wei, Haiyan; Gao, Bei; Gu, Wei
2017-04-10
Effective conservation and utilization strategies for natural biological resources require a clear understanding of the geographic distribution of the target species. Tricholoma matsutake is an ectomycorrhizal (ECM) mushroom with high ecological and economic value. In this study, the potential geographic distribution of T. matsutake under current conditions in China was simulated using MaxEnt software based on species presence data and 24 environmental variables. The future distributions of T. matsutake in the 2050s and 2070s were also projected under the RCP 8.5, RCP 6, RCP 4.5 and RCP 2.6 climate change emission scenarios described in the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The areas of marginally suitable, suitable and highly suitable habitats for T. matsutake in China were approximately 0.22 × 10 6 km 2 , 0.14 × 10 6 km 2 , and 0.11 × 10 6 km 2 , respectively. The model simulations indicated that the area of marginally suitable habitats would undergo a relatively small change under all four climate change scenarios; however, suitable habitats would significantly decrease, and highly suitable habitat would nearly disappear. Our results will be influential in the future ecological conservation and management of T. matsutake and can be used as a reference for studies on other ectomycorrhizal mushroom species.
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NASA Astrophysics Data System (ADS)
Guo, Yanlong; Li, Xin; Zhao, Zefang; Wei, Haiyan; Gao, Bei; Gu, Wei
2017-04-01
Effective conservation and utilization strategies for natural biological resources require a clear understanding of the geographic distribution of the target species. Tricholoma matsutake is an ectomycorrhizal (ECM) mushroom with high ecological and economic value. In this study, the potential geographic distribution of T. matsutake under current conditions in China was simulated using MaxEnt software based on species presence data and 24 environmental variables. The future distributions of T. matsutake in the 2050s and 2070s were also projected under the RCP 8.5, RCP 6, RCP 4.5 and RCP 2.6 climate change emission scenarios described in the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The areas of marginally suitable, suitable and highly suitable habitats for T. matsutake in China were approximately 0.22 × 106 km2, 0.14 × 106 km2, and 0.11 × 106 km2, respectively. The model simulations indicated that the area of marginally suitable habitats would undergo a relatively small change under all four climate change scenarios; however, suitable habitats would significantly decrease, and highly suitable habitat would nearly disappear. Our results will be influential in the future ecological conservation and management of T. matsutake and can be used as a reference for studies on other ectomycorrhizal mushroom species.
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Guo, Yanlong; Li, Xin; Zhao, Zefang; Wei, Haiyan; Gao, Bei; Gu, Wei
2017-01-01
Effective conservation and utilization strategies for natural biological resources require a clear understanding of the geographic distribution of the target species. Tricholoma matsutake is an ectomycorrhizal (ECM) mushroom with high ecological and economic value. In this study, the potential geographic distribution of T. matsutake under current conditions in China was simulated using MaxEnt software based on species presence data and 24 environmental variables. The future distributions of T. matsutake in the 2050s and 2070s were also projected under the RCP 8.5, RCP 6, RCP 4.5 and RCP 2.6 climate change emission scenarios described in the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The areas of marginally suitable, suitable and highly suitable habitats for T. matsutake in China were approximately 0.22 × 106 km2, 0.14 × 106 km2, and 0.11 × 106 km2, respectively. The model simulations indicated that the area of marginally suitable habitats would undergo a relatively small change under all four climate change scenarios; however, suitable habitats would significantly decrease, and highly suitable habitat would nearly disappear. Our results will be influential in the future ecological conservation and management of T. matsutake and can be used as a reference for studies on other ectomycorrhizal mushroom species. PMID:28393865
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Predicting the geographical distribution of two invasive termite species from occurrence data.
Tonini, Francesco; Divino, Fabio; Lasinio, Giovanna Jona; Hochmair, Hartwig H; Scheffrahn, Rudolf H
2014-10-01
Predicting the potential habitat of species under both current and future climate change scenarios is crucial for monitoring invasive species and understanding a species' response to different environmental conditions. Frequently, the only data available on a species is the location of its occurrence (presence-only data). Using occurrence records only, two models were used to predict the geographical distribution of two destructive invasive termite species, Coptotermes gestroi (Wasmann) and Coptotermes formosanus Shiraki. The first model uses a Bayesian linear logistic regression approach adjusted for presence-only data while the second one is the widely used maximum entropy approach (Maxent). Results show that the predicted distributions of both C. gestroi and C. formosanus are strongly linked to urban development. The impact of future scenarios such as climate warming and population growth on the biotic distribution of both termite species was also assessed. Future climate warming seems to affect their projected probability of presence to a lesser extent than population growth. The Bayesian logistic approach outperformed Maxent consistently in all models according to evaluation criteria such as model sensitivity and ecological realism. The importance of further studies for an explicit treatment of residual spatial autocorrelation and a more comprehensive comparison between both statistical approaches is suggested.
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NASA Astrophysics Data System (ADS)
Wang, Gaoxu; Zeng, Xiaofan; Zhao, Na; He, Qifang; Bai, Yiran; Zhang, Ruoyu
2018-02-01
The relationships between the river discharge and the precipitation in the Jinsha River basin are discussed in this study. In addition, the future precipitation trend from 2011-2050 and its potential influence on the river discharge are analysed by applying the CCLM-modelled precipitation. According to the observed river discharge and precipitation, the annual river discharge at the two main hydrological stations displays good correlations with the annual precipitation in the Jinsha River basin. The predicted future precipitation tends to change similarly as the change that occurred during the observation period, whereas the monthly distributions over a year could be more uneven, which is unfavourable for water resources management.
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Shafer, Sarah L; Bartlein, Patrick J; Gray, Elizabeth M; Pelltier, Richard T
2015-01-01
Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0-58.0°N latitude by 136.6-103.0°W longitude). LPJ is a process-based vegetation model that mechanistically simulates the effect of changing climate and atmospheric CO2 concentrations on vegetation. It was developed and has been mostly applied at spatial resolutions of 10-minutes or coarser. In this study, we used LPJ at a 30-second (~1-km) spatial resolution to simulate potential vegetation changes for 2070-2099. LPJ was run using downscaled future climate simulations from five coupled atmosphere-ocean general circulation models (CCSM3, CGCM3.1(T47), GISS-ER, MIROC3.2(medres), UKMO-HadCM3) produced using the A2 greenhouse gases emissions scenario. Under projected future climate and atmospheric CO2 concentrations, the simulated vegetation changes result in the contraction of alpine, shrub-steppe, and xeric shrub vegetation across the study area and the expansion of woodland and forest vegetation. Large areas of maritime cool forest and cold forest are simulated to persist under projected future conditions. The fine spatial-scale vegetation simulations resolve patterns of vegetation change that are not visible at coarser resolutions and these fine-scale patterns are particularly important for understanding potential future vegetation changes in topographically complex areas.
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The Distributed Wind Cost Taxonomy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Forsyth, Trudy; Jimenez, Tony; Preus, Robert
To date, there has been no standard method or tool to analyze the installed and operational costs for distributed wind turbine systems. This report describes the development of a classification system, or taxonomy, for distributed wind turbine project costs. The taxonomy establishes a framework to help collect, sort, and compare distributed wind cost data that mirrors how the industry categorizes information. The taxonomy organizes costs so they can be aggregated from installers, developers, vendors, and other sources without losing cost details. Developing a peer-reviewed taxonomy is valuable to industry stakeholders because a common understanding the details of distributed wind turbinemore » costs and balance of station costs is a first step to identifying potential high-value cost reduction opportunities. Addressing cost reduction potential can help increase distributed wind's competitiveness and propel the U.S. distributed wind industry forward. The taxonomy can also be used to perform cost comparisons between technologies and track trends for distributed wind industry costs in the future. As an initial application and piloting of the taxonomy, preliminary cost data were collected for projects of different sizes and from different regions across the contiguous United States. Following the methods described in this report, these data are placed into the established cost categories.« less
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Application of future remote sensing systems to irrigation
NASA Technical Reports Server (NTRS)
Miller, L. D.
1982-01-01
Area estimates of irrigated crops and knowledge of crop type are required for modeling water consumption to assist farmers, rangers, and agricultural consultants in scheduling irrigation for distributed management of crop yields. Information on canopy physiology and soil moisture status on a spatial basis is potentially available from remote sensors, so the questions to be addressed relate to: (1) timing (data frequency, instantaneous and integrated measurement); and scheduling (widely distributed spatial demands); (2) spatial resolution; (3) radiometric and geometric accuracy and geoencoding; and (4) information/data distribution. This latter should be overnight, with no central storage, onsite capture, and low cost.
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USDA-ARS?s Scientific Manuscript database
Climate change will impact bioclimatic drivers that regulate the geospatial distribution of dryland agro-ecological classes (AECs). Characterizing the geospatial relationship between present AECs and their bioclimatic controls will provide insights into potential future shifts in AECs as climate cha...
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Potential geographic distribution of Palmer amaranth under current and future climates
USDA-ARS?s Scientific Manuscript database
Herbicide resistant weeds are increasingly becoming a major challenge for agricultural production worldwide. Palmer amaranth is an invasive annual forb that has recently emerged as one of the most widespread and severe agronomic weeds in the US, due in part to its facility for evolving herbicide res...
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78 FR 46783 - Federal Acquisition Regulation; Documenting Contractor Performance
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-01
... determinations in FAR subpart 9.1 and the impact of a contractor with more than one contract to have a negative... forecasting and cost controlling and the impact on future contracts. This respondent felt that a contractor... (including potential economic, environmental, public health and safety effects, distributive impacts, and...
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Potential changes in forest composition could reduce impacts of climate change on boreal wildfires.
Terrier, Aurélie; Girardin, Martin P; Périé, Catherine; Legendre, Pierre; Bergeron, Yves
2013-01-01
There is general consensus that wildfires in boreal forests will increase throughout this century in response to more severe and frequent drought conditions induced by climate change. However, prediction models generally assume that the vegetation component will remain static over the next few decades. As deciduous species are less flammable than conifer species, it is reasonable to believe that a potential expansion of deciduous species in boreal forests, either occurring naturally or through landscape management, could offset some of the impacts of climate change on the occurrence of boreal wildfires. The objective of this study was to determine the potential of this offsetting effect through a simulation experiment conducted in eastern boreal North America. Predictions of future fire activity were made using multivariate adaptive regression splines (MARS) with fire behavior indices and ecological niche models as predictor variables so as to take into account the effects of changing climate and tree distribution on fire activity. A regional climate model (RCM) was used for predictions of future fire risk conditions. The experiment was conducted under two tree dispersal scenarios: the status quo scenario, in which the distribution of forest types does not differ from the present one, and the unlimited dispersal scenario, which allows forest types to expand their range to fully occupy their climatic niche. Our results show that future warming will create climate conditions that are more prone to fire occurrence. However, unlimited dispersal of southern restricted deciduous species could reduce the impact of climate change on future fire occurrence. Hence, the use of deciduous species could be a good option for an efficient strategic fire mitigation strategy aimed at reducing fire Propagation in coniferous landscapes and increasing public safety in remote populated areas of eastern boreal Canada under climate change.
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Thomassen, Henri A.; Fuller, Trevon; Asefi-Najafabady, Salvi; Shiplacoff, Julia A. G.; Mulembakani, Prime M.; Blumberg, Seth; Johnston, Sara C.; Kisalu, Neville K.; Kinkela, Timothée L.; Fair, Joseph N.; Wolfe, Nathan D.; Shongo, Robert L.; LeBreton, Matthew; Meyer, Hermann; Wright, Linda L.; Muyembe, Jean-Jacques; Buermann, Wolfgang; Okitolonda, Emile; Hensley, Lisa E.; Lloyd-Smith, James O.; Smith, Thomas B.; Rimoin, Anne W.
2013-01-01
Climate change is predicted to result in changes in the geographic ranges and local prevalence of infectious diseases, either through direct effects on the pathogen, or indirectly through range shifts in vector and reservoir species. To better understand the occurrence of monkeypox virus (MPXV), an emerging Orthopoxvirus in humans, under contemporary and future climate conditions, we used ecological niche modeling techniques in conjunction with climate and remote-sensing variables. We first created spatially explicit probability distributions of its candidate reservoir species in Africa's Congo Basin. Reservoir species distributions were subsequently used to model current and projected future distributions of human monkeypox (MPX). Results indicate that forest clearing and climate are significant driving factors of the transmission of MPX from wildlife to humans under current climate conditions. Models under contemporary climate conditions performed well, as indicated by high values for the area under the receiver operator curve (AUC), and tests on spatially randomly and non-randomly omitted test data. Future projections were made on IPCC 4th Assessment climate change scenarios for 2050 and 2080, ranging from more conservative to more aggressive, and representing the potential variation within which range shifts can be expected to occur. Future projections showed range shifts into regions where MPX has not been recorded previously. Increased suitability for MPX was predicted in eastern Democratic Republic of Congo. Models developed here are useful for identifying areas where environmental conditions may become more suitable for human MPX; targeting candidate reservoir species for future screening efforts; and prioritizing regions for future MPX surveillance efforts. PMID:23935820
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Guo, Yanlong; Lu, Chunyan; Gao, Bei
2016-01-01
Climate change will significantly affect plant distribution as well as the quality of medicinal plants. Although numerous studies have analyzed the effect of climate change on future habitats of plants through species distribution models (SDMs), few of them have incorporated the change of effective content of medicinal plants. Schisandra sphenanthera Rehd. et Wils. is an endangered traditional Chinese medical plant which is mainly located in the Qinling Mountains. Combining fuzzy theory and a maximum entropy model, we obtained current spatial distribution of quality assessment for S. spenanthera. Moreover, the future quality and distribution of S. spenanthera were also projected for the periods 2020s, 2050s and 2080s under three different climate change scenarios (SRES-A1B, SRES-A2 and SRES-B1 emission scenarios) described in the Special Report on Emissions Scenarios (SRES) of IPCC (Intergovernmental Panel on Climate Change). The results showed that the moderately suitable habitat of S. sphenanthera under all climate change scenarios remained relatively stable in the study area. The highly suitable habitat of S. sphenanthera would gradually decrease in the future and a higher decline rate of the highly suitable habitat area would occur under climate change scenarios SRES-A1B and SRES-A2. The result suggested that in the study area, there would be no more highly suitable habitat areas for S. sphenanthera when the annual mean temperature exceeds 20 °C or its annual precipitation exceeds 1,200 mm. Our results will be influential in the future ecological conservation and management of S. sphenanthera and can be taken as a reference for habitat suitability assessment research for other medicinal plants. PMID:27781160
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Photovoltaics as a terrestrial energy source. Volume 1: An introduction
NASA Technical Reports Server (NTRS)
Smith, J. L.
1980-01-01
Photovoltaic (PV) systems were examined their potential for terrestrial application and future development. Photovoltaic technology, existing and potential photovoltaic applications, and the National Photovoltaics Program are reviewed. The competitive environment for this electrical source, affected by the presence or absence of utility supplied power is evaluated in term of systems prices. The roles of technological breakthroughs, directed research and technology development, learning curves, and commercial demonstrations in the National Program are discussed. The potential for photovoltaics to displace oil consumption is examined, as are the potential benefits of employing PV in either central-station or non-utility owned, small, distributed systems.
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Lagerholm, Vendela K; Sandoval-Castellanos, Edson; Vaniscotte, Amélie; Potapova, Olga R; Tomek, Teresa; Bochenski, Zbigniew M; Shepherd, Paul; Barton, Nick; Van Dyck, Marie-Claire; Miller, Rebecca; Höglund, Jacob; Yoccoz, Nigel G; Dalén, Love; Stewart, John R
2017-04-01
Global warming is predicted to cause substantial habitat rearrangements, with the most severe effects expected to occur in high-latitude biomes. However, one major uncertainty is whether species will be able to shift their ranges to keep pace with climate-driven environmental changes. Many recent studies on mammals have shown that past range contractions have been associated with local extinctions rather than survival by habitat tracking. Here, we have used an interdisciplinary approach that combines ancient DNA techniques, coalescent simulations and species distribution modelling, to investigate how two common cold-adapted bird species, willow and rock ptarmigan (Lagopus lagopus and Lagopus muta), respond to long-term climate warming. Contrary to previous findings in mammals, we demonstrate a genetic continuity in Europe over the last 20 millennia. Results from back-casted species distribution models suggest that this continuity may have been facilitated by uninterrupted habitat availability and potentially also the greater dispersal ability of birds. However, our predictions show that in the near future, some isolated regions will have little suitable habitat left, implying a future decrease in local populations at a scale unprecedented since the last glacial maximum. © 2016 John Wiley & Sons Ltd.
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Impact of climate and host availability on future distribution of Colorado potato beetle.
Wang, Cong; Hawthorne, David; Qin, Yujia; Pan, Xubin; Li, Zhihong; Zhu, Shuifang
2017-07-03
Colorado Potato Beetle (CPB) is a devastating invasive pest of potato both in its native North America and now across Eurasia. It also damages eggplant, tomato and feeds on several wild species in the Solanaceae, such as S. eleagnifolium and S. rostratum Dunal (SR). Since first categorized as a pest in 1864, CPB has spread rapidly across North America, Europe and Asia. In light of its invasiveness and economic importance, it is necessary to study how climate change and host availability may alter the distribution of the CPB. Maximum Entropy (MaxEnt) models were used to anticipate global range expansion as influenced by environmental conditions, and by the possibility of cooperative invasion of CPB and its wild host SR. The results indicate that both CPB and SR can occupy warm areas of North America, South Africa, Europe, China, and Australia. Future climate conditions may promote CPB expansion into northern regions and SR into the circumpolar latitudes. The existing range and continued spread of SR may also assist the global expansion of CPB. Future management of this pest should consider the impacts of global climate change and host availability on its potential global distribution.
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Vidal-García, Francisca; Serio-Silva, Juan Carlos
2011-07-01
We developed a potential distribution model for the tropical rain forest species of primates of southern Mexico: the black howler monkey (Alouatta pigra), the mantled howler monkey (Alouatta palliata), and the spider monkey (Ateles geoffroyi). To do so, we applied the maximum entropy algorithm from the ecological niche modeling program MaxEnt. For each species, we used occurrence records from scientific collections, and published and unpublished sources, and we also used the 19 environmental coverage variables related to precipitation and temperature from WorldClim to develop the models. The predicted distribution of A. pigra was strongly associated with the mean temperature of the warmest quarter (23.6%), whereas the potential distributions of A. palliata and A. geoffroyi were strongly associated with precipitation during the coldest quarter (52.2 and 34.3% respectively). The potential distribution of A. geoffroyi is broader than that of the Alouatta spp. The areas with the greatest probability of presence of A. pigra and A. palliata are strongly associated with riparian vegetation, whereas the presence of A. geoffroyi is more strongly associated with the presence of rain forest. Our most significant contribution is the identification of areas with a high probability of the presence of these primate species, which is information that can be applied to planning future studies and then establishing criteria for the creation of areas to primate conservation in Mexico.
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Minoli, Ignacio; Avila, Luciano Javier
2017-02-26
The consequences of global climate change can already be seen in many physical and biological systems and these effects could change the distribution of suitable areas for a wide variety of organisms to the middle of this century. We analyzed the current habitat use and we projected the suitable area of present conditions into the geographical space of future scenarios (2050), to assess and quantify whether future climate change would affect the distribution and size of suitable environments in two Pristidactylus lizard species. Comparing the habitat use and future forecasts of the two studied species, P. achalensis showed a more restricted use of available resource units (RUs) and a moderate reduction of the potential future area. On the contrary, P. nigroiugulus uses more available RUs and has a considerable area decrease for both future scenarios. These results suggest that both species have a moderately different trend towards reducing available area of suitable habitats, the persistent localities for both 2050 CO2 concentration models, and in the available RUs used. We discussed the relation between size and use of the current habitat, changes in future projections along with the protected areas from present-future and the usefulness of these results in conservation plans. This work illustrates how ectothermic organisms might have to face major changes in their availability suitable areas as a consequence of the effect of future climate change.
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Alimi, Temitope O; Fuller, Douglas O; Qualls, Whitney A; Herrera, Socrates V; Arevalo-Herrera, Myriam; Quinones, Martha L; Lacerda, Marcus V G; Beier, John C
2015-08-20
Changes in land use and land cover (LULC) as well as climate are likely to affect the geographic distribution of malaria vectors and parasites in the coming decades. At present, malaria transmission is concentrated mainly in the Amazon basin where extensive agriculture, mining, and logging activities have resulted in changes to local and regional hydrology, massive loss of forest cover, and increased contact between malaria vectors and hosts. Employing presence-only records, bioclimatic, topographic, hydrologic, LULC and human population data, we modeled the distribution of malaria and two of its dominant vectors, Anopheles darlingi, and Anopheles nuneztovari s.l. in northern South America using the species distribution modeling platform Maxent. Results from our land change modeling indicate that about 70,000 km(2) of forest land would be lost by 2050 and 78,000 km(2) by 2070 compared to 2010. The Maxent model predicted zones of relatively high habitat suitability for malaria and the vectors mainly within the Amazon and along coastlines. While areas with malaria are expected to decrease in line with current downward trends, both vectors are predicted to experience range expansions in the future. Elevation, annual precipitation and temperature were influential in all models both current and future. Human population mostly affected An. darlingi distribution while LULC changes influenced An. nuneztovari s.l. distribution. As the region tackles the challenge of malaria elimination, investigations such as this could be useful for planning and management purposes and aid in predicting and addressing potential impediments to elimination.
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Kim, Sung-Soo; Chun, Jung Hwa; Park, Young-Seuk
2016-01-01
Global warming is likely leading to species’ distributional shifts, resulting in changes in local community compositions and diversity patterns. In this study, we applied species distribution models to evaluate the potential impacts of temperature increase on ant communities in Korean temperate forests, by testing hypotheses that 1) the risk of extinction of forest ant species would increase over time, and 2) the changes in species distribution ranges could drive upward movements of ant communities and further alter patterns of species richness. We sampled ant communities at 335 evenly distributed sites across South Korea and modelled the future distribution range for each species using generalized additive models. To account for spatial autocorrelation, autocovariate regressions were conducted prior to generalized additive models. Among 29 common ant species, 12 species were estimated to shrink their suitable geographic areas, whereas five species would benefit from future global warming. Species richness was highest at low altitudes in the current period, and it was projected to be highest at the mid-altitudes in the 2080s, resulting in an upward movement of 4.9 m yr−1. This altered the altitudinal pattern of species richness from a monotonic-decrease curve (common in temperate regions) to a bell-shaped curve (common in tropical regions). Overall, ant communities in temperate forests are vulnerable to the on-going global warming and their altitudinal movements are similar to other faunal communities. PMID:27504632
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Thompson, Robert S.; Anderson, Katherine H.; Pelltier, Richard T.; Shafer, Sarah L.; Bartlein, Patrick J.
2007-01-01
Climate is the primary factor controlling the continental-scale distribution of plant species, although the relations between climatic parameters and species' ranges are only now beginning to be quantified. This volume examines the relations between climate and the distributions of (1) Kuchler's 'potential natural vegetation' categories for the 48 contiguous States of the United States of America, (2) Bailey's ecoregions of North America, and (3) World Wildlife Fund's ecoregions of North America. For these analyses, we employed a 25-kilometer equal-area grid of modern climatic and bioclimatic parameters for North America, coupled with presence-absence data for the occurrence of each ecoregion under the three classification systems under consideration. The resulting relations between climate and ecoregion distributions are presented in graphical and tabular form. Presentation of ecoregion-climate relations here is intended to be useful for a greater understanding of ecosystem evolution, ecosystem dynamics, and potential effects of future climate change on ecoregions.
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Prediction future asset price which is non-concordant with the historical distribution
NASA Astrophysics Data System (ADS)
Seong, Ng Yew; Hin, Pooi Ah
2015-12-01
This paper attempts to predict the major characteristics of the future asset price which is non-concordant with the distribution estimated from the price today and the prices on a large number of previous days. The three major characteristics of the i-th non-concordant asset price are the length of the interval between the occurrence time of the previous non-concordant asset price and that of the present non-concordant asset price, the indicator which denotes that the non-concordant price is extremely small or large by its values -1 and 1 respectively, and the degree of non-concordance given by the negative logarithm of the probability of the left tail or right tail of which one of the end points is given by the observed future price. The vector of three major characteristics of the next non-concordant price is modelled to be dependent on the vectors corresponding to the present and l - 1 previous non-concordant prices via a 3-dimensional conditional distribution which is derived from a 3(l + 1)-dimensional power-normal mixture distribution. The marginal distribution for each of the three major characteristics can then be derived from the conditional distribution. The mean of the j-th marginal distribution is an estimate of the value of the j-th characteristics of the next non-concordant price. Meanwhile, the 100(α/2) % and 100(1 - α/2) % points of the j-th marginal distribution can be used to form a prediction interval for the j-th characteristic of the next non-concordant price. The performance measures of the above estimates and prediction intervals indicate that the fitted conditional distribution is satisfactory. Thus the incorporation of the distribution of the characteristics of the next non-concordant price in the model for asset price has a good potential of yielding a more realistic model.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Long, Philip E.; Wurstner, Signe K.; Sullivan, E. C.
Ice coverage of the Arctic Ocean is predicted to become thinner and to cover less area with time. The combination of more ice-free waters for exploration and navigation, along with increasing demand for hydrocarbons and improvements in technologies for the discovery and exploitation of new hydrocarbon resources have focused attention on the hydrocarbon potential of the Arctic Basin and its margins. The purpose of this document is to 1) summarize results of a review of published hydrocarbon resources in the Arctic, including both conventional oil and gas and methane hydrates and 2) develop a set of digital maps of themore » hydrocarbon potential of the Arctic Ocean. These maps can be combined with predictions of ice-free areas to enable estimates of the likely regions and sequence of hydrocarbon production development in the Arctic. In this report, conventional oil and gas resources are explicitly linked with potential gas hydrate resources. This has not been attempted previously and is particularly powerful as the likelihood of gas production from marine gas hydrates increases. Available or planned infrastructure, such as pipelines, combined with the geospatial distribution of hydrocarbons is a very strong determinant of the temporal-spatial development of Arctic hydrocarbon resources. Significant unknowns decrease the certainty of predictions for development of hydrocarbon resources. These include: 1) Areas in the Russian Arctic that are poorly mapped, 2) Disputed ownership: primarily the Lomonosov Ridge, 3) Lack of detailed information on gas hydrate distribution, and 4) Technical risk associated with the ability to extract methane gas from gas hydrates. Logistics may control areas of exploration more than hydrocarbon potential. Accessibility, established ownership, and leasing of exploration blocks may trump quality of source rock, reservoir, and size of target. With this in mind, the main areas that are likely to be explored first are the Bering Strait and Chukchi Sea, in spite of the fact that these areas do not have highest potential for future hydrocarbon reserves. Opportunities for improving the mapping and assessment of Arctic hydrocarbon resources include: 1) Refining hydrocarbon potential on a basin-by-basin basis, 2) Developing more realistic and detailed distribution of gas hydrate, and 3) Assessing the likely future scenarios for development of infrastructure and their interaction with hydrocarbon potential. It would also be useful to develop a more sophisticated approach to merging conventional and gas hydrate resource potential that considers the technical uncertainty associated with exploitation of gas hydrate resources. Taken together, additional work in these areas could significantly improve our understanding of the exploitation of Arctic hydrocarbons as ice-free areas increase in the future.« less
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NASA Astrophysics Data System (ADS)
Kato, Takeyoshi; Sugimoto, Hiroyuki; Suzuoki, Yasuo
We established a procedure for estimating regional electricity demand and regional potential capacity of distributed generators (DGs) by using a grid square statistics data set. A photovoltaic power system (PV system) for residential use and a co-generation system (CGS) for both residential and commercial use were taken into account. As an example, the result regarding Aichi prefecture was presented in this paper. The statistical data of the number of households by family-type and the number of employees by business category for about 4000 grid-square with 1km × 1km area was used to estimate the floor space or the electricity demand distribution. The rooftop area available for installing PV systems was also estimated with the grid-square statistics data set. Considering the relation between a capacity of existing CGS and a scale-index of building where CGS is installed, the potential capacity of CGS was estimated for three business categories, i.e. hotel, hospital, store. In some regions, the potential capacity of PV systems was estimated to be about 10,000kW/km2, which corresponds to the density of the existing area with intensive installation of PV systems. Finally, we discussed the ratio of regional potential capacity of DGs to regional maximum electricity demand for deducing the appropriate capacity of DGs in the model of future electricity distribution system.
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Ensuring chemical safety and sustainability form a main priority of the U.S. Environmental Protection Agency. This entails efforts on multiple fronts to characterize the potential hazard posed by chemicals currently in use and those to be commercialized in the future. The use of ...
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Codling moth establishment in China: stages of invasion and potential future distribution
USDA-ARS?s Scientific Manuscript database
Codling moth (Cydia pomonella L.) is an internal feeding pest of apples and can cause substantial economic losses to fruit growers due to larval feeding which in turn degrades fruit quality and can result in complete crop loss if left uncontrolled. Although this pest originally developed in central ...
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Constrained range expansion and climate change assessments
Yohay Carmel; Curtis H. Flather
2006-01-01
Modeling the future distribution of keystone species has proved to be an important approach to assessing the potential ecological consequences of climate change (Loehle and LeBlanc 1996; Hansen et al. 2001). Predictions of range shifts are typically based on empirical models derived from simple correlative relationships between climatic characteristics of occupied and...
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USDA-ARS?s Scientific Manuscript database
The oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), is a primary pest of stone fruits in many countries, including the United States. The distribution of this pest is concentrated in areas receiving higher than lower rainfall. It prefers sites where stone fruits and apple...
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Forest carbon trends in the Southern United States
Robert A. Mickler; James E. Smith; Linda S. Heath
2004-01-01
Forest, agricultural, rangeland, wetland, and urban landscapes have different rates of carbon (C) sequestration and total C sequestration potential under alternative management options. Future changes in the proportion and spatial distribution of land use could increase or decrease the capacity of areas to sequester C in terrestrial ecosystems. As the ecosystems within...
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The Potential Role of Drexon LaserCards in Optical Publishing.
ERIC Educational Resources Information Center
Schwerin, Julie B.
1985-01-01
Describes Drexon LaserCard (credit card size format holding two megabytes of digital data that can be recorded at factory or by information distributors) as a viable option to rotating optical media for distribution of computer software, technical manuals, periodicals, and other document applications, and projects its future in optical publishing.…
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High Speed Computing, LANs, and WAMs
NASA Technical Reports Server (NTRS)
Bergman, Larry A.; Monacos, Steve
1994-01-01
Optical fiber networks may one day offer potential capacities exceeding 10 terabits/sec. This paper describes present gigabit network techniques for distributed computing as illustrated by the CASA gigabit testbed, and then explores future all-optic network architectures that offer increased capacity, more optimized level of service for a given application, high fault tolerance, and dynamic reconfigurability.
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Declining Prevalence of Disease Vectors Under Climate Change
NASA Astrophysics Data System (ADS)
Escobar, Luis E.; Romero-Alvarez, Daniel; Leon, Renato; Lepe-Lopez, Manuel A.; Craft, Meggan E.; Borbor-Cordova, Mercy J.; Svenning, Jens-Christian
2016-12-01
More than half of the world population is at risk of vector-borne diseases including dengue fever, chikungunya, zika, yellow fever, leishmaniasis, chagas disease, and malaria, with highest incidences in tropical regions. In Ecuador, vector-borne diseases are present from coastal and Amazonian regions to the Andes Mountains; however, a detailed characterization of the distribution of their vectors has never been carried out. We estimate the distribution of 14 vectors of the above vector-borne diseases under present-day and future climates. Our results consistently suggest that climate warming is likely threatening some vector species with extinction, locally or completely. These results suggest that climate change could reduce the burden of specific vector species. Other vector species are likely to shift and constrain their geographic range to the highlands in Ecuador potentially affecting novel areas and populations. These forecasts show the need for development of early prevention strategies for vector species currently absent in areas projected as suitable under future climate conditions. Informed interventions could reduce the risk of human exposure to vector species with distributional shifts, in response to current and future climate changes. Based on the mixed effects of future climate on human exposure to disease vectors, we argue that research on vector-borne diseases should be cross-scale and include climatic, demographic, and landscape factors, as well as forces facilitating disease transmission at fine scales.
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Distribution, abundance and habitat use of deep diving cetaceans in the North-East Atlantic
NASA Astrophysics Data System (ADS)
Rogan, Emer; Cañadas, Ana; Macleod, Kelly; Santos, M. Begoña; Mikkelsen, Bjarni; Uriarte, Ainhize; Van Canneyt, Olivier; Vázquez, José Antonio; Hammond, Philip S.
2017-07-01
In spite of their oceanic habitat, deep diving cetacean species have been found to be affected by anthropogenic activities, with potential population impacts of high intensity sounds generated by naval research and oil prospecting receiving the most attention. Improving the knowledge of the distribution and abundance of this poorly known group is an essential prerequisite to inform mitigation strategies seeking to minimize their spatial and temporal overlap with human activities. We provide for the first time abundance estimates for five deep diving cetacean species (sperm whale, long-finned pilot whale, northern bottlenose whale, Cuvier's beaked whale and Sowerby's beaked whale) using data from three dedicated cetacean sighting surveys that covered the oceanic and shelf waters of the North-East Atlantic. Density surface modelling was used to obtain model-based estimates of abundance and to explore the physical and biological characteristics of the habitat used by these species. Distribution of all species was found to be significantly related to depth, distance from the 2000m depth contour, the contour index (a measure of variability in the seabed) and sea surface temperature. Predicted distribution maps also suggest that there is little spatial overlap between these species. Our results represent the best abundance estimates for deep-diving whales in the North-East Atlantic, predict areas of high density during summer and constitute important baseline information to guide future risk assessments of human activities on these species, evaluate potential spatial and temporal trends and inform EU Directives and future conservation efforts.
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Stensgaard, Anna-Sofie; Utzinger, Jürg; Vounatsou, Penelope; Hürlimann, Eveline; Schur, Nadine; Saarnak, Christopher F L; Simoonga, Christopher; Mubita, Patricia; Kabatereine, Narcis B; Tchuem Tchuenté, Louis-Albert; Rahbek, Carsten; Kristensen, Thomas K
2013-11-01
The geographical ranges of most species, including many infectious disease agents and their vectors and intermediate hosts, are assumed to be constrained by climatic tolerances, mainly temperature. It has been suggested that global warming will cause an expansion of the areas potentially suitable for infectious disease transmission. However, the transmission of infectious diseases is governed by a myriad of ecological, economic, evolutionary and social factors. Hence, a deeper understanding of the total disease system (pathogens, vectors and hosts) and its drivers is important for predicting responses to climate change. Here, we combine a growing degree day model for Schistosoma mansoni with species distribution models for the intermediate host snail (Biomphalaria spp.) to investigate large-scale environmental determinants of the distribution of the African S. mansoni-Biomphalaria system and potential impacts of climatic changes. Snail species distribution models included several combinations of climatic and habitat-related predictors; the latter divided into "natural" and "human-impacted" habitat variables to measure anthropogenic influence. The predictive performance of the combined snail-parasite model was evaluated against a comprehensive compilation of historical S. mansoni parasitological survey records, and then examined for two climate change scenarios of increasing severity for 2080. Future projections indicate that while the potential S. mansoni transmission area expands, the snail ranges are more likely to contract and/or move into cooler areas in the south and east. Importantly, we also note that even though climate per se matters, the impact of humans on habitat play a crucial role in determining the distribution of the intermediate host snails in Africa. Thus, a future contraction in the geographical range size of the intermediate host snails caused by climatic changes does not necessarily translate into a decrease or zero-sum change in human schistosomiasis prevalence. Copyright © 2011 Elsevier B.V. All rights reserved.
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Business logic for geoprocessing of distributed geodata
NASA Astrophysics Data System (ADS)
Kiehle, Christian
2006-12-01
This paper describes the development of a business-logic component for the geoprocessing of distributed geodata. The business logic acts as a mediator between the data and the user, therefore playing a central role in any spatial information system. The component is used in service-oriented architectures to foster the reuse of existing geodata inventories. Based on a geoscientific case study of groundwater vulnerability assessment and mapping, the demands for such architectures are identified with special regard to software engineering tasks. Methods are derived from the field of applied Geosciences (Hydrogeology), Geoinformatics, and Software Engineering. In addition to the development of a business logic component, a forthcoming Open Geospatial Consortium (OGC) specification is introduced: the OGC Web Processing Service (WPS) specification. A sample application is introduced to demonstrate the potential of WPS for future information systems. The sample application Geoservice Groundwater Vulnerability is described in detail to provide insight into the business logic component, and demonstrate how information can be generated out of distributed geodata. This has the potential to significantly accelerate the assessment and mapping of groundwater vulnerability. The presented concept is easily transferable to other geoscientific use cases dealing with distributed data inventories. Potential application fields include web-based geoinformation systems operating on distributed data (e.g. environmental planning systems, cadastral information systems, and others).
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Lai, Edward Chia-Cheng; Man, Kenneth K C; Chaiyakunapruk, Nathorn; Cheng, Ching-Lan; Chien, Hsu-Chih; Chui, Celine S L; Dilokthornsakul, Piyameth; Hardy, N Chantelle; Hsieh, Cheng-Yang; Hsu, Chung Y; Kubota, Kiyoshi; Lin, Tzu-Chieh; Liu, Yanfang; Park, Byung Joo; Pratt, Nicole; Roughead, Elizabeth E; Shin, Ju-Young; Watcharathanakij, Sawaeng; Wen, Jin; Wong, Ian C K; Yang, Yea-Huei Kao; Zhang, Yinghong; Setoguchi, Soko
2015-11-01
This study describes the availability and characteristics of databases in Asian-Pacific countries and assesses the feasibility of a distributed network approach in the region. A web-based survey was conducted among investigators using healthcare databases in the Asia-Pacific countries. Potential survey participants were identified through the Asian Pharmacoepidemiology Network. Investigators from a total of 11 databases participated in the survey. Database sources included four nationwide claims databases from Japan, South Korea, and Taiwan; two nationwide electronic health records from Hong Kong and Singapore; a regional electronic health record from western China; two electronic health records from Thailand; and cancer and stroke registries from Taiwan. We identified 11 databases with capabilities for distributed network approaches. Many country-specific coding systems and terminologies have been already converted to international coding systems. The harmonization of health expenditure data is a major obstacle for future investigations attempting to evaluate issues related to medical costs.
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NASA Astrophysics Data System (ADS)
Pulido-Velazquez, David; Collados-Lara, Antonio-Juan; Alcalá, Francisco J.
2017-04-01
This research proposes and applies a method to assess potential impacts of future climatic scenarios on aquifer rainfall recharge in wide and varied regions. The continental Spain territory was selected to show the application. The method requires to generate future series of climatic variables (precipitation, temperature) in the system to simulate them within a previously calibrated hydrological model for the historical data. In a previous work, Alcalá and Custodio (2014) used the atmospheric chloride mass balance (CMB) method for the spatial evaluation of average aquifer recharge by rainfall over the whole of continental Spain, by assuming long-term steady conditions of the balance variables. The distributed average CMB variables necessary to calculate recharge were estimated from available variable-length data series of variable quality and spatial coverage. The CMB variables were regionalized by ordinary kriging at the same 4976 nodes of a 10 km x 10 km grid. Two main sources of uncertainty affecting recharge estimates (given by the coefficient of variation, CV), induced by the inherent natural variability of the variables and from mapping were segregated. Based on these stationary results we define a simple empirical rainfall-recharge model. We consider that spatiotemporal variability of rainfall and temperature are the most important climatic feature and variables influencing potential aquifer recharge in natural regime. Changes in these variables can be important in the assessment of future potential impacts of climatic scenarios over spatiotemporal renewable groundwater resource. For instance, if temperature increases, actual evapotranspitration (EA) will increases reducing the available water for others groundwater balance components, including the recharge. For this reason, instead of defining an infiltration rate coefficient that relates precipitation (P) and recharge we propose to define a transformation function that allows estimating the spatial distribution of recharge (both average value and its uncertainty) from the difference in P and EA in each area. A complete analysis of potential short-term (2016-2045) future climate scenarios in continental Spain has been performed by considering different sources of uncertainty. It is based on the historical climatic data for the period 1976-2005 and the climatic models simulations (for the control [1976-2005] and future scenarios [2016-2045]) performed in the frame of the CORDEX EU project. The most pessimistic emission scenario (RCP8.5) has been considered. For the RCP8.5 scenario we have analyzed the time series generated by simulating with 5 Regional Climatic models (CCLM4-8-17, RCA4, HIRHAM5, RACMO22E, and WRF331F) nested to 4 different General Circulation Models (GCMs). Two different conceptual approaches (bias correction and delta change techniques) have been applied to generate potential future climate scenarios from these data. Different ensembles of obtained time series have been proposed to obtain more representative scenarios by considering all the simulations or only those providing better approximations to the historical statistics based on a multicriteria analysis. This was a step to analyze future potential impacts on the aquifer recharge by simulating them within a rainfall-recharge model. This research has been supported by the CGL2013-48424-C2-2-R (MINECO) and the PMAFI/06/14 (UCAM) projects.
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Counting Jobs and Economic Impacts from Distributed Wind in the United States (Poster)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tegen, S.
This conference poster describes the distributed wind Jobs and Economic Development Imapcts (JEDI) model. The goal of this work is to provide a model that estimates jobs and other economic effects associated with the domestic distributed wind industry. The distributed wind JEDI model is a free input-output model that estimates employment and other impacts resulting from an investment in distributed wind installations. Default inputs are from installers and industry experts and are based on existing projects. User input can be minimal (use defaults) or very detailed for more precise results. JEDI can help evaluate potential scenarios, current or future; informmore » stakeholders and decision-makers; assist businesses in evaluating economic development impacts and estimating jobs; assist government organizations with planning and evaluating and developing communities.« less
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Ruosch, Melanie; Spahni, Renato; Joos, Fortunat; Henne, Paul D; van der Knaap, Willem O; Tinner, Willy
2016-02-01
Information on how species distributions and ecosystem services are impacted by anthropogenic climate change is important for adaptation planning. Palaeo data suggest that Abies alba formed forests under significantly warmer-than-present conditions in Europe and might be a native substitute for widespread drought-sensitive temperate and boreal tree species such as beech (Fagus sylvatica) and spruce (Picea abies) under future global warming conditions. Here, we combine pollen and macrofossil data, modern observations, and results from transient simulations with the LPX-Bern dynamic global vegetation model to assess past and future distributions of A. alba in Europe. LPX-Bern is forced with climate anomalies from a run over the past 21 000 years with the Community Earth System Model, modern climatology, and with 21st-century multimodel ensemble results for the high-emission RCP8.5 and the stringent mitigation RCP2.6 pathway. The simulated distribution for present climate encompasses the modern range of A. alba, with the model exceeding the present distribution in north-western and southern Europe. Mid-Holocene pollen data and model results agree for southern Europe, suggesting that at present, human impacts suppress the distribution in southern Europe. Pollen and model results both show range expansion starting during the Bølling-Allerød warm period, interrupted by the Younger Dryas cold, and resuming during the Holocene. The distribution of A. alba expands to the north-east in all future scenarios, whereas the potential (currently unrealized) range would be substantially reduced in southern Europe under RCP8.5. A. alba maintains its current range in central Europe despite competition by other thermophilous tree species. Our combined palaeoecological and model evidence suggest that A. alba may ensure important ecosystem services including stand and slope stability, infrastructure protection, and carbon sequestration under significantly warmer-than-present conditions in central Europe. © 2015 John Wiley & Sons Ltd.
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[Predictions of potential geographical distribution of Alhagi sparsifolia under climate change].
Yang, Xia; Zheng, Jiang-Hua; Mu, Chen; Lin, Jun
2017-02-01
Specific information on geographic distribution of a species is important for its conservation. This study was conducted to determine the potential geographic distribution of Alhagi sparsifolia, which is a plant used in traditional Uighur medicine, and predict how climate change would affect its geographic range. The potential geographic distribution of A. sparsifolia under the current conditions in China was simulated with MaxEnt software based on species presence data at 42 locations and 19 climatic variables. The future distributions of A. sparsifolia were also projected in 2050 and 2070 under the climate change scenarios of RCP2.6 and RCP8.5 described in 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).The result showed that mean temperature of the coldest quarter, annual mean temperature, precipitation of the coldest quarter, annual precipitation, precipitation of the wettest month, mean temperature of the wettest quarter and the temperature annual range were the seven climatic factors influencing the geographic distribution of A. sparsifolia under current climate, the suitable habitats are mainly located in the Xinjiang, in the middle and north of Gansu, in the west of Neimeng, in the north of Nei Monggol. From 2050 to 2070, the model simulations indicated that the suitable habitats of A. sparsifolia would decrease under the climate change scenarios of RCP2.6 and scenarios of RCP8.5 on the whole. Copyright© by the Chinese Pharmaceutical Association.
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Species distribution modelling for conservation of an endangered endemic orchid
Wang, Hsiao-Hsuan; Wonkka, Carissa L.; Treglia, Michael L.; Grant, William E.; Smeins, Fred E.; Rogers, William E.
2015-01-01
Concerns regarding the long-term viability of threatened and endangered plant species are increasingly warranted given the potential impacts of climate change and habitat fragmentation on unstable and isolated populations. Orchidaceae is the largest and most diverse family of flowering plants, but it is currently facing unprecedented risks of extinction. Despite substantial conservation emphasis on rare orchids, populations continue to decline. Spiranthes parksii (Navasota ladies' tresses) is a federally and state-listed endangered terrestrial orchid endemic to central Texas. Hence, we aimed to identify potential factors influencing the distribution of the species, quantify the relative importance of each factor and determine suitable habitat for future surveys and targeted conservation efforts. We analysed several geo-referenced variables describing climatic conditions and landscape features to identify potential factors influencing the likelihood of occurrence of S. parksii using boosted regression trees. Our model classified 97 % of the cells correctly with regard to species presence and absence, and indicated that probability of existence was correlated with climatic conditions and landscape features. The most influential variables were mean annual precipitation, mean elevation, mean annual minimum temperature and mean annual maximum temperature. The most likely suitable range for S. parksii was the eastern portions of Leon and Madison Counties, the southern portion of Brazos County, a portion of northern Grimes County and along the borders between Burleson and Washington Counties. Our model can assist in the development of an integrated conservation strategy through: (i) focussing future survey and research efforts on areas with a high likelihood of occurrence, (ii) aiding in selection of areas for conservation and restoration and (iii) framing future research questions including those necessary for predicting responses to climate change. Our model could also incorporate new information on S. parksii as it becomes available to improve prediction accuracy, and our methodology could be adapted to develop distribution maps for other rare species of conservation concern. PMID:25900746
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Iannella, Mattia; Cerasoli, Francesco; D'Alessandro, Paola; Console, Giulia; Biondi, Maurizio
2018-01-01
The pond turtle Emys trinacris is an endangered endemic species of Sicily showing a fragmented distribution throughout the main island. In this study, we applied "Ensemble Niche Modelling", combining more classical statistical techniques as Generalized Linear Models and Multivariate Adaptive Regression Splines with machine-learning approaches as Boosted Regression Trees and Maxent, to model the potential distribution of the species under current and future climatic conditions. Moreover, a "gap analysis" performed on both the species' presence sites and the predictions from the Ensemble Models is proposed to integrate outputs from these models, in order to assess the conservation status of this threatened species in the context of biodiversity management. For this aim, four "Representative Concentration Pathways", corresponding to different greenhouse gases emissions trajectories were considered to project the obtained models to both 2050 and 2070. Areas lost, gained or remaining stable for the target species in the projected models were calculated. E. trinacris ' potential distribution resulted to be significantly dependent upon precipitation-linked variables, mainly precipitation of wettest and coldest quarter. Future negative effects for the conservation of this species, because of more unstable precipitation patterns and extreme meteorological events, emerged from our analyses. Further, the sites currently inhabited by E. trinacris are, for more than a half, out of the Protected Areas network, highlighting an inadequate management of the species by the authorities responsible for its protection. Our results, therefore, suggest that in the next future the Sicilian pond turtle will need the utmost attention by the scientific community to avoid the imminent risk of extinction. Finally, the gap analysis performed in GIS environment resulted to be a very informative post-modeling technique, potentially applicable to the management of species at risk and to Protected Areas' planning in many contexts.
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Species distribution modelling for conservation of an endangered endemic orchid.
Wang, Hsiao-Hsuan; Wonkka, Carissa L; Treglia, Michael L; Grant, William E; Smeins, Fred E; Rogers, William E
2015-04-21
Concerns regarding the long-term viability of threatened and endangered plant species are increasingly warranted given the potential impacts of climate change and habitat fragmentation on unstable and isolated populations. Orchidaceae is the largest and most diverse family of flowering plants, but it is currently facing unprecedented risks of extinction. Despite substantial conservation emphasis on rare orchids, populations continue to decline. Spiranthes parksii (Navasota ladies' tresses) is a federally and state-listed endangered terrestrial orchid endemic to central Texas. Hence, we aimed to identify potential factors influencing the distribution of the species, quantify the relative importance of each factor and determine suitable habitat for future surveys and targeted conservation efforts. We analysed several geo-referenced variables describing climatic conditions and landscape features to identify potential factors influencing the likelihood of occurrence of S. parksii using boosted regression trees. Our model classified 97 % of the cells correctly with regard to species presence and absence, and indicated that probability of existence was correlated with climatic conditions and landscape features. The most influential variables were mean annual precipitation, mean elevation, mean annual minimum temperature and mean annual maximum temperature. The most likely suitable range for S. parksii was the eastern portions of Leon and Madison Counties, the southern portion of Brazos County, a portion of northern Grimes County and along the borders between Burleson and Washington Counties. Our model can assist in the development of an integrated conservation strategy through: (i) focussing future survey and research efforts on areas with a high likelihood of occurrence, (ii) aiding in selection of areas for conservation and restoration and (iii) framing future research questions including those necessary for predicting responses to climate change. Our model could also incorporate new information on S. parksii as it becomes available to improve prediction accuracy, and our methodology could be adapted to develop distribution maps for other rare species of conservation concern. Published by Oxford University Press on behalf of the Annals of Botany Company.
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NASA Astrophysics Data System (ADS)
VanCompernolle, M.; Ficklin, D. L.; Knouft, J.
2017-12-01
Streamflow and stream temperature are key variables influencing growth, reproduction, and mortality of freshwater fish. Climate-induced changes in these variables are expected to alter the structure and function of aquatic ecosystems. Using Maxent, a species distribution model (SDM) based on the principal of maximum entropy, we predicted potential distributional responses of 100 fish species in the Mobile River Basin (MRB) to changes in climate based on contemporary and future streamflow and stream temperature estimates. Geologic, topographic, and landcover data were also included in each SDM to determine the contribution of these physical variables in defining areas of suitable habitat for each species. Using an ensemble of Global Climate Model (GCM) projections under a high emissions scenario, predicted distributions for each species across the MRB were produced for both a historical time period, 1975-1994, and a future time period, 2060-2079, and changes in total area and the percent change in historical suitable habitat for each species were calculated. Results indicate that flow (28%), temperature (29%), and geology (29%), on average, contribute evenly to determining areas of suitable habitat for fish species in the MRB, with landcover and slope playing more limited roles. Temperature contributed slightly more predictive ability to SDMs (31%) for the 77 species experiencing overall declines in areas of suitable habitat, but only 21% for the 23 species gaining habitat across all GCMs. Species are expected to lose between 15-24% of their historical suitable habitat, with threatened and endangered species losing 22-30% and those endemic to the MRB losing 19-28%. Sculpins (Cottidae) are expected to lose the largest amount of historical habitat (up to 84%), while pygmy sunfish (Elassomatidae) are expected to lose less than 1% of historical habitat. Understanding which species may be at risk of habitat loss under future projections of climate change can help fisheries managers better prepare for potential alterations in species composition not only within the MRB, but other watersheds throughout the world.
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An approach to evaluating reactive airborne wind shear systems
NASA Technical Reports Server (NTRS)
Gibson, Joseph P., Jr.
1992-01-01
An approach to evaluating reactive airborne windshear detection systems was developed to support a deployment study for future FAA ground-based windshear detection systems. The deployment study methodology assesses potential future safety enhancements beyond planned capabilities. The reactive airborne systems will be an integral part of planned windshear safety enhancements. The approach to evaluating reactive airborne systems involves separate analyses for both landing and take-off scenario. The analysis estimates the probability of effective warning considering several factors including NASA energy height loss characteristics, reactive alert timing, and a probability distribution for microburst strength.
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Payload accommodations. Avionics payload support architecture
NASA Technical Reports Server (NTRS)
Creasy, Susan L.; Levy, C. D.
1990-01-01
Concepts for vehicle and payload avionics architectures for future NASA programs, including the Assured Shuttle Access program, Space Station Freedom (SSF), Shuttle-C, Advanced Manned Launch System (AMLS), and the Lunar/Mars programs are discussed. Emphasis is on the potential available to increase payload services which will be required in the future, while decreasing the operational cost/complexity by utilizing state of the art advanced avionics systems and a distributed processing architecture. Also addressed are the trade studies required to determine the optimal degree of vehicle (NASA) to payload (customer) separation and the ramifications of these decisions.
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Lewis, Jesse S.; Farnsworth, Matthew L.; Burdett, Chris L.; Theobald, David M.; Gray, Miranda; Miller, Ryan S.
2017-01-01
Biotic and abiotic factors are increasingly acknowledged to synergistically shape broad-scale species distributions. However, the relative importance of biotic and abiotic factors in predicting species distributions is unclear. In particular, biotic factors, such as predation and vegetation, including those resulting from anthropogenic land-use change, are underrepresented in species distribution modeling, but could improve model predictions. Using generalized linear models and model selection techniques, we used 129 estimates of population density of wild pigs (Sus scrofa) from 5 continents to evaluate the relative importance, magnitude, and direction of biotic and abiotic factors in predicting population density of an invasive large mammal with a global distribution. Incorporating diverse biotic factors, including agriculture, vegetation cover, and large carnivore richness, into species distribution modeling substantially improved model fit and predictions. Abiotic factors, including precipitation and potential evapotranspiration, were also important predictors. The predictive map of population density revealed wide-ranging potential for an invasive large mammal to expand its distribution globally. This information can be used to proactively create conservation/management plans to control future invasions. Our study demonstrates that the ongoing paradigm shift, which recognizes that both biotic and abiotic factors shape species distributions across broad scales, can be advanced by incorporating diverse biotic factors. PMID:28276519
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Perspectives on invasive amphibians in Brazil
Forti, Lucas Rodriguez; Becker, C. Guilherme; Tacioli, Leandro; Pereira, Vânia Rosa; Santos, André Cid F. A.; Oliveira, Igor; Haddad, Célio F. B.; Toledo, Luís Felipe
2017-01-01
Introduced species have the potential to become invasive and jeopardize entire ecosystems. The success of species establishing viable populations outside their original extent depends primarily on favorable climatic conditions in the invasive ranges. Species distribution modeling (SDM) can thus be used to estimate potential habitat suitability for populations of invasive species. Here we review the status of six amphibian species with invasive populations in Brazil (four domestic species and two imported species). We (i) modeled the current habitat suitability and future potential distribution of these six focal species, (ii) reported on the disease status of Eleutherodactylus johnstonei and Phyllodytes luteolus, and (iii) quantified the acoustic overlap of P. luteolus and Leptodactylus labyrinthicus with three co-occurring native species. Our models indicated that all six invasive species could potentially expand their ranges in Brazil within the next few decades. In addition, our SDMs predicted important expansions in available habitat for 2 out of 6 invasive species under future (2100) climatic conditions. We detected high acoustic niche overlap between invasive and native amphibian species, underscoring that acoustic interference might reduce mating success in local frogs. Despite the American bullfrog Lithobates catesbeianus being recognized as a potential reservoir for the frog-killing fungus Batrachochytrium dendrobatidis (Bd) in Brazil, we did not detect Bd in the recently introduced population of E. johnstonei and P. luteolus in the State of São Paulo. We emphasize that the number of invasive amphibian species in Brazil is increasing exponentially, highlighting the urgent need to monitor and control these populations and decrease potential impacts on the locally biodiverse wildlife. PMID:28938024
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Perspectives on invasive amphibians in Brazil.
Forti, Lucas Rodriguez; Becker, C Guilherme; Tacioli, Leandro; Pereira, Vânia Rosa; Santos, André Cid F A; Oliveira, Igor; Haddad, Célio F B; Toledo, Luís Felipe
2017-01-01
Introduced species have the potential to become invasive and jeopardize entire ecosystems. The success of species establishing viable populations outside their original extent depends primarily on favorable climatic conditions in the invasive ranges. Species distribution modeling (SDM) can thus be used to estimate potential habitat suitability for populations of invasive species. Here we review the status of six amphibian species with invasive populations in Brazil (four domestic species and two imported species). We (i) modeled the current habitat suitability and future potential distribution of these six focal species, (ii) reported on the disease status of Eleutherodactylus johnstonei and Phyllodytes luteolus, and (iii) quantified the acoustic overlap of P. luteolus and Leptodactylus labyrinthicus with three co-occurring native species. Our models indicated that all six invasive species could potentially expand their ranges in Brazil within the next few decades. In addition, our SDMs predicted important expansions in available habitat for 2 out of 6 invasive species under future (2100) climatic conditions. We detected high acoustic niche overlap between invasive and native amphibian species, underscoring that acoustic interference might reduce mating success in local frogs. Despite the American bullfrog Lithobates catesbeianus being recognized as a potential reservoir for the frog-killing fungus Batrachochytrium dendrobatidis (Bd) in Brazil, we did not detect Bd in the recently introduced population of E. johnstonei and P. luteolus in the State of São Paulo. We emphasize that the number of invasive amphibian species in Brazil is increasing exponentially, highlighting the urgent need to monitor and control these populations and decrease potential impacts on the locally biodiverse wildlife.
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Sahagún Sánchez, Francisco Javier; Navarro, Jaime Castro; Reyes Hernández, Humberto
2013-06-01
The Sierra Madre Oriental region in the mexican state of San Luis Potosi is a relevant place for bird conservation at a country level. Therefore the main goal of this study was to analyze the geographic patterns of distribution and the conservation current state of the birds, to support the needs to expand the conservation areas in the future. Data was collected from various databases of zoological museums and collections, and field sampling methods conducted from January 2009 to May 2011. Potential distributions were modeled for 284 species using GARP software and then a map was developed to determine areas with favorable environmental characteristics for the distribution of species richness. Finally, the importance of conservation areas for the potential distribution of birds in the region was evaluated. A total of 359 species were recorded of which 71.4% are permanent residents, 19% are winter migrants and 4% are summer residents. From this total, 41 species were endemic, 47 were species at risk and 149 were neotropical migrants. The largest species richness correspond to oak forests, cloud forests, and tropical moist forests located at altitudes from 100m to 1 500m. Their potential distribution was concentrated towards the center and Southeast of the study area. Only 10% of areas with a high potential conservation was included in areas of priority for bird conservation (AICA) and just 3% of all potential areas were under some governmental category of protection. However, no conservation area has a management plan currently applied and monitored. The information generated is important for the development of management proposals for birds conservation in the region.
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Storage, transmission and distribution of hydrogen
NASA Technical Reports Server (NTRS)
Kelley, J. H.; Hagler, R., Jr.
1979-01-01
Current practices and future requirements for the storage, transmission and distribution of hydrogen are reviewed in order to identify inadequacies to be corrected before hydrogen can achieve its full potential as a substitute for fossil fuels. Consideration is given to the storage of hydrogen in underground solution-mined salt caverns, portable high-pressure containers and dewars, pressure vessels and aquifers and as metal hydrides, hydrogen transmission in evacuated double-walled insulated containers and by pipeline, and distribution by truck and internal distribution networks. Areas for the improvement of these techniques are indicated, and these technological deficiencies, including materials development, low-cost storage and transmission methods, low-cost, long-life metal hydrides and novel methods for hydrogen storage, are presented as challenges for research and development.
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Not all nonnormal distributions are created equal: Improved theoretical and measurement precision.
Joo, Harry; Aguinis, Herman; Bradley, Kyle J
2017-07-01
We offer a four-category taxonomy of individual output distributions (i.e., distributions of cumulative results): (1) pure power law; (2) lognormal; (3) exponential tail (including exponential and power law with an exponential cutoff); and (4) symmetric or potentially symmetric (including normal, Poisson, and Weibull). The four categories are uniquely associated with mutually exclusive generative mechanisms: self-organized criticality, proportionate differentiation, incremental differentiation, and homogenization. We then introduce distribution pitting, a falsification-based method for comparing distributions to assess how well each one fits a given data set. In doing so, we also introduce decision rules to determine the likely dominant shape and generative mechanism among many that may operate concurrently. Next, we implement distribution pitting using 229 samples of individual output for several occupations (e.g., movie directors, writers, musicians, athletes, bank tellers, call center employees, grocery checkers, electrical fixture assemblers, and wirers). Results suggest that for 75% of our samples, exponential tail distributions and their generative mechanism (i.e., incremental differentiation) likely constitute the dominant distribution shape and explanation of nonnormally distributed individual output. This finding challenges past conclusions indicating the pervasiveness of other types of distributions and their generative mechanisms. Our results further contribute to theory by offering premises about the link between past and future individual output. For future research, our taxonomy and methodology can be used to pit distributions of other variables (e.g., organizational citizenship behaviors). Finally, we offer practical insights on how to increase overall individual output and produce more top performers. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
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Perspectives on the Future of CFD
NASA Technical Reports Server (NTRS)
Kwak, Dochan
2000-01-01
This viewgraph presentation gives an overview of the future of computational fluid dynamics (CFD), which in the past has pioneered the field of flow simulation. Over time CFD has progressed as computing power. Numerical methods have been advanced as CPU and memory capacity increases. Complex configurations are routinely computed now and direct numerical simulations (DNS) and large eddy simulations (LES) are used to study turbulence. As the computing resources changed to parallel and distributed platforms, computer science aspects such as scalability (algorithmic and implementation) and portability and transparent codings have advanced. Examples of potential future (or current) challenges include risk assessment, limitations of the heuristic model, and the development of CFD and information technology (IT) tools.
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Wei, Jiufeng; Zhao, Qing; Zhao, Wanqing; Zhang, Hufang
2018-01-01
Cycads are an ancient group of gymnosperms that are popular as landscaping plants, though nearly all of them are threatened or endangered in the wild. The cycad aulacaspis scale (CAS), Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae), has become one of the most serious pests of cycads in recent years; however, the potential distribution range and the management approach for this pest are unclear. A potential risk map of cycad aulacaspis scale was created based on occurrence data under different climatic conditions and topology factors in this study. Furthermore, the future potential distributions of CAS were projected for the periods 2050s and 2070s under three different climate change scenarios (GFDL-CM3, HADGEM2-AO and MIROC5) described in the Special Report on Emissions Scenarios of the IPCC (Intergovernmental Panel on Climate Change). The model suggested high environmental suitability for the continents of Asia and North America, where the species has already been recorded. The potential distribution expansions or reductions were also predicted under different climate change conditions. Temperature of Driest Quarter (Bio9) was the most important factor, explaining 48.1% of the distribution of the species. The results also suggested that highly suitable habitat for CAS would exist in the study area if the mean temperature of 15-20 °C in the driest quarter and a mean temperature of 25-28 °C the wettest quarter. This research provides a theoretical reference framework for developing policy to manage and control this invasive pest.
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Heterogeneous High Throughput Scientific Computing with APM X-Gene and Intel Xeon Phi
NASA Astrophysics Data System (ADS)
Abdurachmanov, David; Bockelman, Brian; Elmer, Peter; Eulisse, Giulio; Knight, Robert; Muzaffar, Shahzad
2015-05-01
Electrical power requirements will be a constraint on the future growth of Distributed High Throughput Computing (DHTC) as used by High Energy Physics. Performance-per-watt is a critical metric for the evaluation of computer architectures for cost- efficient computing. Additionally, future performance growth will come from heterogeneous, many-core, and high computing density platforms with specialized processors. In this paper, we examine the Intel Xeon Phi Many Integrated Cores (MIC) co-processor and Applied Micro X-Gene ARMv8 64-bit low-power server system-on-a-chip (SoC) solutions for scientific computing applications. We report our experience on software porting, performance and energy efficiency and evaluate the potential for use of such technologies in the context of distributed computing systems such as the Worldwide LHC Computing Grid (WLCG).
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Applications of space observations to the management and utilization of coastal fishery resources
NASA Technical Reports Server (NTRS)
Kemmerer, A. J.; Savastano, K. J.; Faller, K. H.
1977-01-01
Information needs of those concerned with the harvest and management of coastal fishery resources can be satisfied in part through applications of satellite remote sensing. Recently completed and ongoing investigations have demonstrated potentials for defining fish distribution patterns from multispectral data, monitoring fishing distribution and effort with synthetic aperture radar systems, forecasting recruitment of certain estuarine-dependent species, and tracking marine mammals. These investigations, which are reviewed in this paper, have relied on Landsat 1 and 2, Skylab-3, and Nimbus-6 supported sensors and sensors carried by aircraft and mounted on surface platforms to simulate applications from Seasat-A and other future spacecraft systems. None of the systems are operational as all were designed to identify and demonstrate applications and to aid in the specification of requirements for future spaceborne systems.
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Zhao, Wanqing; Zhao, Qing
2017-01-01
The cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), is a serious invasive species that significantly damages plants of approximately 60 families around the world. It is originally from North America and has also been introduced to other continents. Our goals were to create a current and future potential global distribution map for this pest under climate change with MaxEnt software. We tested the hypothesis of niche conservatism for P. solenopsis by comparing its native niche in North America to its invasive niches on other continents using Principal components analyses (PCA) in R. The potentially suitable habitat for P. solenopsis in its native and non-native ranges is presented in the present paper. The results suggested that the mean temperature of the wettest quarter and the mean temperature of the driest quarter are the most important environmental variables determining the potential distribution of P. solenopsis. We found strong evidence for niche shifts in the realized climatic niche of this pest in South America and Australia due to niche unfilling; however, a niche shift in the realized climatic niche of this pest in Eurasian owing to niche expansion. PMID:28700721
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Onshore wind energy potential over Iberia: present and future projections
NASA Astrophysics Data System (ADS)
Rochinha, Carlos A.; Santos, João A.; Liberato, Margarida L. R.; Pinto, Joaquim G.
2014-05-01
Onshore grid-connected wind power generation has been explored for more than three decades in the Iberian Peninsula. Further, increasing attention has been devoted to renewable energy sources in a climate change context. While advantages of wind energy are widely recognized, its distribution is not spatially homogeneous and not uniform throughout the year. Hence, understanding these spatial-temporal distributions is critical in power system planning. The present study aims at assessing the potential power output estimated from 10 m wind components simulated by a regional climate model (CCLM), driven by ERA40 reanalysis. Datasets are available on a grid with a high spatial resolution (approximately 20 km) and over a 40-yr period (1961-2000). Furthermore, several target sites, located in areas with high installed wind generation capacity, are selected for local-to-regional scale assessments. The results show that potential wind power is higher over northern Iberia, mostly in Cantabria and Galicia, while Andalucía and Cataluña record the lowest values. With respect to the intra-annual variability, summer is by far the season with the lowest potential energy outputs. Furthermore, the inter-annual variability reveals an overall downward long-term trend over the 40-yr period, particularly in the winter time series. A CCLM transient experiment, forced by the SRES A1B emission scenario, is also discussed for a future period (2041-2070), after a model validation/calibration process (bias corrections). Significant changes in the wind power potential are projected for the future throughout Iberia, but their magnitude largely depends on the locations. This work was partially supported by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE (Programa Operacional Factores de Competitividade) and by national funds through FCT (Fundação para a Ciência e a Tecnologia, Portugal) under project STORMEx FCOMP-01-0124-FEDER- 019524 (PTDC/AAC-CLI/121339/2010).
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SunShot 2030 for Photovoltaics (PV): Envisioning a Low-cost PV Future
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cole, Wesley J.; Frew, Bethany A.; Gagnon, Pieter J.
In this report we summarize the implications, impacts, and deployment potential of reaching the SunShot 2030 targets for the electricity system in the contiguous United States. We model 25 scenarios of the U.S. power sector using the Regional Energy Deployment Systems (ReEDS) and Distributed Generation (dGen) capacity expansion models. The scenarios cover a wide range of sensitivities to capture future uncertainties relating to fuel prices, retirements, renewable energy capital costs, and load growth. We give special attention to the potential for storage costs to also rapidly decline due to its large synergies with low-cost solar. The ReEDS and dGen modelsmore » project utility- and distributed-scale power sector evolution, respectively, for the United States. Both models have been designed with special emphasis on capturing the unique traits of renewable energy, including variability and grid integration requirements. Across the suite of scenarios modeled, we find that reaching the SunShot 2030 target has the potential to lead to significant capacity additions of PV in the United States. By 2050, PV penetration levels are projected to reach 28-46 percent of total generation. If storage also sees significant reductions in cost, then the 2050 solar penetration levels could reach 41-64 percent. PV deployment is projected to occur in all of the lower 48 states, though the specific deployment level is scenario dependent. The growth in PV is projected to be dominated by utility-scale systems, but the actual mix between utility and distributed systems could ultimately vary depending on how policies, system costs, and rate structures evolve.« less
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Glacial Refugia and Future Habitat Coverage of Selected Dactylorhiza Representatives (Orchidaceae)
2015-01-01
The intensively discussed taxonomic complexity of the Dactylorhiza genus is probably correlated with its migration history during glaciations and interglacial periods. Previous studies on past processes affecting the current distribution of Dactylorhiza species as well as the history of the polyploid complex formation were based only on molecular data. In the present study the ecological niche modeling (ENM) technique was applied in order to describe the distribution of potential refugia for the selected Dactylorhiza representatives during the Last Glacial Maximum. Additionally, future changes in their potential habitat coverage were measured with regard to three various climatic change scenarios. The maximum entropy method was used to create models of suitable niche distribution. A database of Dactylorhiza localities was prepared on the grounds of information collected from literature and data gathered during field works. Our research indicated that the habitats of majority of the studied taxa will decrease by 2080, except for D. incarnata var. incarnata, for which suitable habitats will increase almost two-fold in the global scale. Moreover, the potential habitats of some taxa are located outside their currently known geographical ranges, e.g. the Aleutian Islands, the western slopes of the Rocky Mountains, Newfoundland, southern Greenland and Iceland. ENM analysis did not confirm that the Balkans, central Europe or central Russia served as the most important refugia for individual representatives of the Dactylorhiza incarnata/maculata complex. Our study rather indicated that the Black Sea coast, southern Apennines and Corsica were the main areas characterized by habitats suitable for most of the taxa. PMID:26599630
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Perspective on intelligent avionics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jones, H.L.
1987-01-01
Technical issues which could potentially limit the capability and acceptibility of expert systems decision-making for avionics applications are addressed. These issues are: real-time AI, mission-critical software, conventional algorithms, pilot interface, knowledge acquisition, and distributed expert systems. Examples from on-going expert system development programs are presented to illustrate likely architectures and applications of future intelligent avionic systems. 13 references.
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Evaluating the sources of potential migrant species: implications under climate change
Ines Ibanez; James S. Clark; Michael C. Dietze
2008-01-01
As changes in climate become more apparent, ecologists face the challenge of predicting species responses to the new conditions. Most forecasts are based on climate envelopes (CE), correlative approaches that project future distributions on the basis of the current climate often assuming some dispersal lag. One major caveat with this approach is that it ignores the...
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Research in Modeling and Simulation for Airspace Systems Innovation
NASA Technical Reports Server (NTRS)
Ballin, Mark G.; Kimmel, William M.; Welch, Sharon S.
2007-01-01
This viewgraph presentation provides an overview of some of the applied research and simulation methodologies at the NASA Langley Research Center that support aerospace systems innovation. Risk assessment methodologies, complex systems design and analysis methodologies, and aer ospace operations simulations are described. Potential areas for future research and collaboration using interactive and distributed simula tions are also proposed.
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Russell, Richard C; Currie, Bart J; Lindsay, Michael D; Mackenzie, John S; Ritchie, Scott A; Whelan, Peter I
2009-03-02
Dengue transmission in Australia is currently restricted to Queensland, where the vector mosquito Aedes aegypti is established. Locally acquired infections have been reported only from urban areas in the north-east of the state, where the vector is most abundant. Considerable attention has been drawn to the potential impact of climate change on dengue distribution within Australia, with projections for substantial rises in incidence and distribution associated with increasing temperatures. However, historical data show that much of Australia has previously sustained both the vector mosquito and dengue viruses. Although current vector distribution is restricted to Queensland, the area inhabited by A. aegypti is larger than the disease-transmission areas, and is not restricted by temperature (or vector-control programs); thus, it is unlikely that rising temperatures alone will bring increased vector or virus distribution. Factors likely to be important to dengue and vector distribution in the future include increased dengue activity in Asian and Pacific nations that would raise rates of virus importation by travellers, importation of vectors via international ports to regions without A. aegypti, higher rates of domestic collection and storage of water that would provide habitat in urban areas, and growing human populations in northern Australia. Past and recent successful control initiatives in Australia lend support to the idea that well resourced and functioning surveillance programs, and effective public health intervention capabilities, are essential to counter threats from dengue and other mosquito-borne diseases. Models projecting future activity of dengue (or other vector-borne disease) with climate change should carefully consider the local historical and contemporary data on the ecology and distribution of the vector and local virus transmission.
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Wanlass, Paul W; Sikorski, David M; Kizhakkeveettil, Anupama; Tobias, Gene S
2018-03-12
To assess students' opinions of the potential influence of taking elective courses in chiropractic techniques and their future practice preferences. An anonymous, voluntary survey was conducted among graduating students from a doctor of chiropractic program. The survey included questions regarding the chiropractic technique elective courses they had completed and the potential influence of these courses on their chiropractic technique choices in future practice. Surveys were pretested for face validity, and data were analyzed using descriptive and inferential statistics. Of the 56 surveys distributed, 46 were completed, for a response rate of 82%. More than half of the students reported having taken at least 1 elective course in diversified technique (80%), Cox technique (76%), Activator Methods (70%), or sacro-occipital technique (63%). Less than half of the respondents reported taking technique elective courses in Gonstead or Thompson techniques. More than half of the students stated they were more likely to use Activator (72%), Thompson (68%), diversified (57%), or Cox (54%) techniques in their future practice after taking an elective course in that technique. Females stated that they were more likely to use Activator Methods ( p = .006) in future practice. Chiropractic technique elective courses in the doctor of chiropractic curriculum may influence students' choices of future practice chiropractic technique.
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Shafer, Sarah; Bartlein, Patrick J.; Gray, Elizabeth M.; Pelltier, Richard T.
2015-01-01
Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0–58.0°N latitude by 136.6–103.0°W longitude). LPJ is a process-based vegetation model that mechanistically simulates the effect of changing climate and atmospheric CO2 concentrations on vegetation. It was developed and has been mostly applied at spatial resolutions of 10-minutes or coarser. In this study, we used LPJ at a 30-second (~1-km) spatial resolution to simulate potential vegetation changes for 2070–2099. LPJ was run using downscaled future climate simulations from five coupled atmosphere-ocean general circulation models (CCSM3, CGCM3.1(T47), GISS-ER, MIROC3.2(medres), UKMO-HadCM3) produced using the A2 greenhouse gases emissions scenario. Under projected future climate and atmospheric CO2 concentrations, the simulated vegetation changes result in the contraction of alpine, shrub-steppe, and xeric shrub vegetation across the study area and the expansion of woodland and forest vegetation. Large areas of maritime cool forest and cold forest are simulated to persist under projected future conditions. The fine spatial-scale vegetation simulations resolve patterns of vegetation change that are not visible at coarser resolutions and these fine-scale patterns are particularly important for understanding potential future vegetation changes in topographically complex areas.
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Shafer, Sarah L.; Bartlein, Patrick J.; Gray, Elizabeth M.; Pelltier, Richard T.
2015-01-01
Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0–58.0°N latitude by 136.6–103.0°W longitude). LPJ is a process-based vegetation model that mechanistically simulates the effect of changing climate and atmospheric CO2 concentrations on vegetation. It was developed and has been mostly applied at spatial resolutions of 10-minutes or coarser. In this study, we used LPJ at a 30-second (~1-km) spatial resolution to simulate potential vegetation changes for 2070–2099. LPJ was run using downscaled future climate simulations from five coupled atmosphere-ocean general circulation models (CCSM3, CGCM3.1(T47), GISS-ER, MIROC3.2(medres), UKMO-HadCM3) produced using the A2 greenhouse gases emissions scenario. Under projected future climate and atmospheric CO2 concentrations, the simulated vegetation changes result in the contraction of alpine, shrub-steppe, and xeric shrub vegetation across the study area and the expansion of woodland and forest vegetation. Large areas of maritime cool forest and cold forest are simulated to persist under projected future conditions. The fine spatial-scale vegetation simulations resolve patterns of vegetation change that are not visible at coarser resolutions and these fine-scale patterns are particularly important for understanding potential future vegetation changes in topographically complex areas. PMID:26488750
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Fertouna-Bellakhal, Mouna; Dhib, Amel; Béjaoui, Béchir; Turki, Souad; Aleya, Lotfi
2014-07-15
Species composition and abundance of dinocysts in relation to environmental factors were studied at 123 stations of surface sediment in Bizerte Lagoon. Forty-eight dinocyst types were identified, mainly dominated by Brigantidinium simplex, Votadinum spinosum, Alexandrium pseudogonyaulax, Alexandrium catenella, and Lingulodinum machaerophorum along with many round brown cysts and spiny round brown cysts. Cysts ranged from 1276 to 20126 cysts g(-1)dry weight sediment. Significant differences in cyst distribution pattern were recorded among the zones, with a higher cyst abundance occurring in the lagoon's inner areas. Redundancy analyses showed two distinct associations of dinocysts according to location and environmental variables. Ballast water discharges are potential introducers of non-indigenous species, especially harmful ones such as A. catenella and Polysphaeridium zoharyi, with currents playing a pivotal role in cyst distribution. Findings concerning harmful cyst species indicate potential seedbeds for initiation of future blooms and outbreaks of potentially toxic species in the lagoon. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Prestele, Reinhard; Hirsch, Annette L; Davin, Edouard L; Seneviratne, Sonia I; Verburg, Peter H
2018-05-10
Conservation agriculture (CA) is widely promoted as a sustainable agricultural management strategy with the potential to alleviate some of the adverse effects of modern, industrial agriculture such as large-scale soil erosion, nutrient leaching and overexploitation of water resources. Moreover, agricultural land managed under CA is proposed to contribute to climate change mitigation and adaptation through reduced emission of greenhouse gases, increased solar radiation reflection, and the sustainable use of soil and water resources. Due to the lack of official reporting schemes, the amount of agricultural land managed under CA systems is uncertain and spatially explicit information about the distribution of CA required for various modeling studies is missing. Here, we present an approach to downscale present-day national-level estimates of CA to a 5 arcminute regular grid, based on multicriteria analysis. We provide a best estimate of CA distribution and an uncertainty range in the form of a low and high estimate of CA distribution, reflecting the inconsistency in CA definitions. We also design two scenarios of the potential future development of CA combining present-day data and an assessment of the potential for implementation using biophysical and socioeconomic factors. By our estimates, 122-215 Mha or 9%-15% of global arable land is currently managed under CA systems. The lower end of the range represents CA as an integrated system of permanent no-tillage, crop residue management and crop rotations, while the high estimate includes a wider range of areas primarily devoted to temporary no-tillage or reduced tillage operations. Our scenario analysis suggests a future potential of CA in the range of 533-1130 Mha (38%-81% of global arable land). Our estimates can be used in various ecosystem modeling applications and are expected to help identifying more realistic climate mitigation and adaptation potentials of agricultural practices. © 2018 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.
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Barua, N U; Bienemann, A S; Woolley, M; Wyatt, M J; Johnson, D; Lewis, O; Irving, C; Pritchard, G; Gill, S
2015-10-15
Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a 20kDa human protein which has both neuroprotective and neurorestorative activity on dopaminergic neurons and therefore may have application for the treatment of Parkinson's Disease. The aims of this study were to determine the translational potential of convection-enhanced delivery (CED) of MANF for the treatment of PD by studying its distribution in porcine putamen and substantia nigra and to correlate histological distribution with co-infused gadolinium-DTPA using real-time magnetic resonance imaging. We describe the distribution of MANF in porcine putamen and substantia nigra using an implantable CED catheter system using co-infused gadolinium-DTPA to allow real-time MRI tracking of infusate distribution. The distribution of gadolinium-DTPA on MRI correlated well with immunohistochemical analysis of MANF distribution. Volumetric analysis of MANF IHC staining indicated a volume of infusion (Vi) to volume of distribution (Vd) ratio of 3 in putamen and 2 in substantia nigra. This study confirms the translational potential of CED of MANF as a novel treatment strategy in PD and also supports the co-infusion of gadolinium as a proxy measure of MANF distribution in future clinical studies. Further study is required to determine the optimum infusion regime, flow rate and frequency of infusions in human trials. Copyright © 2015 Elsevier B.V. All rights reserved.
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Major challenges for correlational ecological niche model projections to future climate conditions.
Peterson, A Townsend; Cobos, Marlon E; Jiménez-García, Daniel
2018-06-20
Species-level forecasts of distributional potential and likely distributional shifts, in the face of changing climates, have become popular in the literature in the past 20 years. Many refinements have been made to the methodology over the years, and the result has been an approach that considers multiple sources of variation in geographic predictions, and how that variation translates into both specific predictions and uncertainty in those predictions. Although numerous previous reviews and overviews of this field have pointed out a series of assumptions and caveats associated with the methodology, three aspects of the methodology have important impacts but have not been treated previously in detail. Here, we assess those three aspects: (1) effects of niche truncation on model transfers to future climate conditions, (2) effects of model selection procedures on future-climate transfers of ecological niche models, and (3) relative contributions of several factors (replicate samples of point data, general circulation models, representative concentration pathways, and alternative model parameterizations) to overall variance in model outcomes. Overall, the view is one of caution: although resulting predictions are fascinating and attractive, this paradigm has pitfalls that may bias and limit confidence in niche model outputs as regards the implications of climate change for species' geographic distributions. © 2018 New York Academy of Sciences.
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Methane Leaks from Natural Gas Systems Follow Extreme Distributions.
Brandt, Adam R; Heath, Garvin A; Cooley, Daniel
2016-11-15
Future energy systems may rely on natural gas as a low-cost fuel to support variable renewable power. However, leaking natural gas causes climate damage because methane (CH 4 ) has a high global warming potential. In this study, we use extreme-value theory to explore the distribution of natural gas leak sizes. By analyzing ∼15 000 measurements from 18 prior studies, we show that all available natural gas leakage data sets are statistically heavy-tailed, and that gas leaks are more extremely distributed than other natural and social phenomena. A unifying result is that the largest 5% of leaks typically contribute over 50% of the total leakage volume. While prior studies used log-normal model distributions, we show that log-normal functions poorly represent tail behavior. Our results suggest that published uncertainty ranges of CH 4 emissions are too narrow, and that larger sample sizes are required in future studies to achieve targeted confidence intervals. Additionally, we find that cross-study aggregation of data sets to increase sample size is not recommended due to apparent deviation between sampled populations. Understanding the nature of leak distributions can improve emission estimates, better illustrate their uncertainty, allow prioritization of source categories, and improve sampling design. Also, these data can be used for more effective design of leak detection technologies.
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Methane Leaks from Natural Gas Systems Follow Extreme Distributions
Brandt, Adam R.; Heath, Garvin A.; Cooley, Daniel
2016-10-14
Future energy systems may rely on natural gas as a low-cost fuel to support variable renewable power. However, leaking natural gas causes climate damage because methane (CH 4) has a high global warming potential. In this study, we use extreme-value theory to explore the distribution of natural gas leak sizes. By analyzing ~15,000 measurements from 18 prior studies, we show that all available natural gas leakage datasets are statistically heavy-tailed, and that gas leaks are more extremely distributed than other natural and social phenomena. A unifying result is that the largest 5% of leaks typically contribute over 50% of themore » total leakage volume. While prior studies used lognormal model distributions, we show that lognormal functions poorly represent tail behavior. Our results suggest that published uncertainty ranges of CH 4 emissions are too narrow, and that larger sample sizes are required in future studies to achieve targeted confidence intervals. Additionally, we find that cross-study aggregation of datasets to increase sample size is not recommended due to apparent deviation between sampled populations. Finally, understanding the nature of leak distributions can improve emission estimates, better illustrate their uncertainty, allow prioritization of source categories, and improve sampling design. Also, these data can be used for more effective design of leak detection technologies.« less
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Methane Leaks from Natural Gas Systems Follow Extreme Distributions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brandt, Adam R.; Heath, Garvin A.; Cooley, Daniel
Future energy systems may rely on natural gas as a low-cost fuel to support variable renewable power. However, leaking natural gas causes climate damage because methane (CH 4) has a high global warming potential. In this study, we use extreme-value theory to explore the distribution of natural gas leak sizes. By analyzing ~15,000 measurements from 18 prior studies, we show that all available natural gas leakage datasets are statistically heavy-tailed, and that gas leaks are more extremely distributed than other natural and social phenomena. A unifying result is that the largest 5% of leaks typically contribute over 50% of themore » total leakage volume. While prior studies used lognormal model distributions, we show that lognormal functions poorly represent tail behavior. Our results suggest that published uncertainty ranges of CH 4 emissions are too narrow, and that larger sample sizes are required in future studies to achieve targeted confidence intervals. Additionally, we find that cross-study aggregation of datasets to increase sample size is not recommended due to apparent deviation between sampled populations. Finally, understanding the nature of leak distributions can improve emission estimates, better illustrate their uncertainty, allow prioritization of source categories, and improve sampling design. Also, these data can be used for more effective design of leak detection technologies.« less
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Power System Simulation for Policymaking and Making Policymakers
NASA Astrophysics Data System (ADS)
Cohen, Michael Ari
Power system simulation is a vital tool for anticipating, planning for and ultimately addressing future conditions on the power grid, especially in light of contemporary shifts in power generation, transmission and use that are being driven by a desire to utilize more environmentally responsible energy sources. This dissertation leverages power system simulation and engineering-economic analysis to provide initial answers to one open question about future power systems: how will high penetrations of distributed (rooftop) solar power affect the physical and economic operation of distribution feeders? We find that the overall impacts of distributed solar power (both positive and negative) on the feeders we modeled are minor compared to the overall cost of energy, but that there is on average a small net benefit provided by distributed generation. We then describe an effort to make similar analyses more accessible to a non-engineering (high school) audience by developing an educational video game called "Griddle" that is based on the same power system simulation techniques used in the first study. We describe the design and evaluation of Griddle and find that it demonstrates potential to provide students with insights about key power system learning objectives.
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Pinkernell, Stefan; Beszteri, Bánk
2014-08-01
Fragilariopsis kerguelensis, a dominant diatom species throughout the Antarctic Circumpolar Current, is coined to be one of the main drivers of the biological silicate pump. Here, we study the distribution of this important species and expected consequences of climate change upon it, using correlative species distribution modeling and publicly available presence-only data. As experience with SDM is scarce for marine phytoplankton, this also serves as a pilot study for this organism group. We used the maximum entropy method to calculate distribution models for the diatom F. kerguelensis based on yearly and monthly environmental data (sea surface temperature, salinity, nitrate and silicate concentrations). Observation data were harvested from GBIF and the Global Diatom Database, and for further analyses also from the Hustedt Diatom Collection (BRM). The models were projected on current yearly and seasonal environmental data to study current distribution and its seasonality. Furthermore, we projected the seasonal model on future environmental data obtained from climate models for the year 2100. Projected on current yearly averaged environmental data, all models showed similar distribution patterns for F. kerguelensis. The monthly model showed seasonality, for example, a shift of the southern distribution boundary toward the north in the winter. Projections on future scenarios resulted in a moderately to negligibly shrinking distribution area and a change in seasonality. We found a substantial bias in the publicly available observation datasets, which could be reduced by additional observation records we obtained from the Hustedt Diatom Collection. Present-day distribution patterns inferred from the models coincided well with background knowledge and previous reports about F. kerguelensis distribution, showing that maximum entropy-based distribution models are suitable to map distribution patterns for oceanic planktonic organisms. Our scenario projections indicate moderate effects of climate change upon the biogeography of F. kerguelensis.
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Preliminary analysis of the span-distributed-load concept for cargo aircraft design
NASA Technical Reports Server (NTRS)
Whitehead, A. H., Jr.
1975-01-01
A simplified computer analysis of the span-distributed-load airplane (in which payload is placed within the wing structure) has shown that the span-distributed-load concept has high potential for application to future air cargo transport design. Significant increases in payload fraction over current wide-bodied freighters are shown for gross weights in excess of 0.5 Gg (1,000,000 lb). A cruise-matching calculation shows that the trend toward higher aspect ratio improves overall efficiency; that is, less thrust and fuel are required. The optimal aspect ratio probably is not determined by structural limitations. Terminal-area constraints and increasing design-payload density, however, tend to limit aspect ratio.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Collett, Tim; Bahk, Jang-Jun; Frye, Matt
2013-12-31
This topical report represents a pathway toward better understanding of the impact of marine methane hydrates on safety and seafloor stability and future collection of data that can be used by scientists, engineers, managers and planners to study climate change and to assess the feasibility of marine methane hydrate as a potential future energy resource. Our understanding of the occurrence, distribution and characteristics of marine methane hydrates is incomplete; therefore, research must continue to expand if methane hydrates are to be used as a future energy source. Exploring basins with methane hydrates has been occurring for over 30 years, butmore » these efforts have been episodic in nature. To further our understanding, these efforts must be more regular and employ new techniques to capture more data. This plan identifies incomplete areas of methane hydrate research and offers solutions by systematically reviewing known methane hydrate “Science Challenges” and linking them with “Technical Challenges” and potential field program locations.« less
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Formoso, Anahí E; Martin, Gabriel M; Teta, Pablo; Carbajo, Aníbal E; Sauthier, Daniel E Udrizar; Pardiñas, Ulyses F J
2015-01-01
The Patagonian opossum (Lestodelphys halli), the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32 °S and ~49 °S). Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic "space" currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future.
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Garris, Heath W; Mitchell, Randall J; Fraser, Lauchlan H; Barrett, Linda R
2015-02-01
Shifting precipitation patterns brought on by climate change threaten to alter the future distribution of wetlands. We developed a set of models to understand the role climate plays in determining wetland formation on a landscape scale and to forecast changes in wetland distribution for the Midwestern United States. These models combined 35 climate variables with 21 geographic and anthropogenic factors thought to encapsulate other major drivers of wetland distribution for the Midwest. All models successfully recreated a majority of the variation in current wetland area within the Midwest, and showed that wetland area was significantly associated with climate, even when controlling for landscape context. Inferential (linear) models identified a consistent negative association between wetland area and isothermality. This is likely the result of regular inundation in areas where precipitation accumulates as snow, then melts faster than drainage capacity. Moisture index seasonality was identified as a key factor distinguishing between emergent and forested wetland types, where forested wetland area at the landscape scale is associated with a greater seasonal variation in water table depth. Forecasting models (neural networks) predicted an increase in potential wetland area in the coming century, with areas conducive to forested wetland formation expanding more rapidly than areas conducive to emergent wetlands. Local cluster analyses identified Iowa and Northeastern Missouri as areas of anticipated wetland expansion, indicating both a risk to crop production within the Midwest Corn Belt and an opportunity for wetland conservation, while Northern Minnesota and Michigan are potentially at risk of wetland losses under a future climate. © 2014 John Wiley & Sons Ltd.
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NASA Technical Reports Server (NTRS)
Khan, Z.; Vranis, A.; Zavoico, A.; Freid, S.; Manners, B.
2006-01-01
This paper will review potential power system concepts for the development of the lunar outpost including power generation, energy storage, and power management and distribution (PMAD). In particular, the requirements of the initial robotic missions will be discussed and the technologies considered will include cryogenics and regenerative fuel cells (RFC), AC and DC transmission line technology, high voltage and low voltage power transmission, conductor materials of construction and power beaming concepts for transmitting power to difficult to access locations such as at the bottom of craters. Operating conditions, component characteristics, reliability, maintainability, constructability, system safety, technology gaps/risk and adaptability for future lunar missions will be discussed for the technologies considered.
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Assessment of source probabilities for potential tsunamis affecting the U.S. Atlantic coast
Geist, E.L.; Parsons, T.
2009-01-01
Estimating the likelihood of tsunamis occurring along the U.S. Atlantic coast critically depends on knowledge of tsunami source probability. We review available information on both earthquake and landslide probabilities from potential sources that could generate local and transoceanic tsunamis. Estimating source probability includes defining both size and recurrence distributions for earthquakes and landslides. For the former distribution, source sizes are often distributed according to a truncated or tapered power-law relationship. For the latter distribution, sources are often assumed to occur in time according to a Poisson process, simplifying the way tsunami probabilities from individual sources can be aggregated. For the U.S. Atlantic coast, earthquake tsunami sources primarily occur at transoceanic distances along plate boundary faults. Probabilities for these sources are constrained from previous statistical studies of global seismicity for similar plate boundary types. In contrast, there is presently little information constraining landslide probabilities that may generate local tsunamis. Though there is significant uncertainty in tsunami source probabilities for the Atlantic, results from this study yield a comparative analysis of tsunami source recurrence rates that can form the basis for future probabilistic analyses.
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A Sorting Statistic with Application in Neurological Magnetic Resonance Imaging of Autism.
Levman, Jacob; Takahashi, Emi; Forgeron, Cynthia; MacDonald, Patrick; Stewart, Natalie; Lim, Ashley; Martel, Anne
2018-01-01
Effect size refers to the assessment of the extent of differences between two groups of samples on a single measurement. Assessing effect size in medical research is typically accomplished with Cohen's d statistic. Cohen's d statistic assumes that average values are good estimators of the position of a distribution of numbers and also assumes Gaussian (or bell-shaped) underlying data distributions. In this paper, we present an alternative evaluative statistic that can quantify differences between two data distributions in a manner that is similar to traditional effect size calculations; however, the proposed approach avoids making assumptions regarding the shape of the underlying data distribution. The proposed sorting statistic is compared with Cohen's d statistic and is demonstrated to be capable of identifying feature measurements of potential interest for which Cohen's d statistic implies the measurement would be of little use. This proposed sorting statistic has been evaluated on a large clinical autism dataset from Boston Children's Hospital , Harvard Medical School , demonstrating that it can potentially play a constructive role in future healthcare technologies.
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A Sorting Statistic with Application in Neurological Magnetic Resonance Imaging of Autism
Takahashi, Emi; Lim, Ashley; Martel, Anne
2018-01-01
Effect size refers to the assessment of the extent of differences between two groups of samples on a single measurement. Assessing effect size in medical research is typically accomplished with Cohen's d statistic. Cohen's d statistic assumes that average values are good estimators of the position of a distribution of numbers and also assumes Gaussian (or bell-shaped) underlying data distributions. In this paper, we present an alternative evaluative statistic that can quantify differences between two data distributions in a manner that is similar to traditional effect size calculations; however, the proposed approach avoids making assumptions regarding the shape of the underlying data distribution. The proposed sorting statistic is compared with Cohen's d statistic and is demonstrated to be capable of identifying feature measurements of potential interest for which Cohen's d statistic implies the measurement would be of little use. This proposed sorting statistic has been evaluated on a large clinical autism dataset from Boston Children's Hospital, Harvard Medical School, demonstrating that it can potentially play a constructive role in future healthcare technologies. PMID:29796236
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Changes in Benefits of Flood Protection Standard under Climate Change
NASA Astrophysics Data System (ADS)
Lim, W. H.; Koirala, S.; Yamazaki, D.; Hirabayashi, Y.; Kanae, S.
2014-12-01
Understanding potential risk of river flooding under future climate scenarios might be helpful for developing risk management strategies (including mitigation, adaptation). Such analyses are typically performed at the macro scales (e.g., regional, global) where the climate model output could support (e.g., Hirabayashi et al., 2013, Arnell and Gosling, 2014). To understand the potential benefits of infrastructure upgrading as part of climate adaptation strategies, it is also informative to understand the potential impact of different flood protection standards (in terms of return periods) on global river flooding under climate change. In this study, we use a baseline period (forced by observed hydroclimate conditions) and CMIP5 model output (historic and future periods) to drive a global river routing model called CaMa-Flood (Yamazaki et al., 2011) and simulate the river water depth at a spatial resolution of 15 min x 15 min. From the simulated results of baseline period, we use the annual maxima river water depth to fit the Gumbel distribution and prepare the return period-flood risk relationship (involving population and GDP). From the simulated results of CMIP5 model, we also used the annual maxima river water depth to obtain the Gumbel distribution and then estimate the exceedance probability (historic and future periods). We apply the return period-flood risk relationship (above) to the exceedance probability and evaluate the potential risk of river flooding and changes in the benefits of flood protection standard (e.g., 100-year flood of the baseline period) from the past into the future (represented by the representative concentration pathways). In this presentation, we show our preliminary results. References: Arnell, N.W, Gosling, S., N., 2014. The impact of climate change on river flood risk at the global scale. Climatic Change 122: 127-140, doi: 10.1007/s10584-014-1084-5. Hirabayashi et al., 2013. Global flood risk under climate change. Nature Climate Change 3: 816-821, doi: 10.1038/nclimate1911. Yamazaki et al., 2011. A physically based description of floodplain inundation dynamics in a global river routing model. Water Resources Research 47, W04501, doi: 10.1029/2010wr009726.
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Schütt, Ole; Sebastiani, Daniel
2013-04-05
We investigate the quantum-mechanical delocalization of hydrogen in rotational symmetric molecular systems. To this purpose, we perform ab initio path integral molecular dynamics simulations of a methanol molecule to characterize the quantum properties of hydrogen atoms in a representative system by means of their real-space and momentum-space densities. In particular, we compute the spherically averaged momentum distribution n(k) and the pseudoangular momentum distribution n(kθ). We interpret our results by comparing them to path integral samplings of a bare proton in an ideal torus potential. We find that the hydroxyl hydrogen exhibits a toroidal delocalization, which leads to characteristic fingerprints in the line shapes of the momentum distributions. We can describe these specific spectroscopic patterns quantitatively and compute their onset as a function of temperature and potential energy landscape. The delocalization patterns in the projected momentum distribution provide a promising computational tool to address the intriguing phenomenon of quantum delocalization in condensed matter and its spectroscopic characterization. As the momentum distribution n(k) is also accessible through Nuclear Compton Scattering experiments, our results will help to interpret and understand future measurements more thoroughly. Copyright © 2012 Wiley Periodicals, Inc.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Changzheng; Oak Ridge National Lab.; Lin, Zhenhong
Plug-in electric vehicles (PEVs) are widely regarded as an important component of the technology portfolio designed to accomplish policy goals in sustainability and energy security. However, the market acceptance of PEVs in the future remains largely uncertain from today's perspective. By integrating a consumer choice model based on nested multinomial logit and Monte Carlo simulation, this study analyzes the uncertainty of PEV market penetration using Monte Carlo simulation. Results suggest that the future market for PEVs is highly uncertain and there is a substantial risk of low penetration in the early and midterm market. Top factors contributing to market sharemore » variability are price sensitivities, energy cost, range limitation, and charging availability. The results also illustrate the potential effect of public policies in promoting PEVs through investment in battery technology and infrastructure deployment. Here, continued improvement of battery technologies and deployment of charging infrastructure alone do not necessarily reduce the spread of market share distributions, but may shift distributions toward right, i.e., increase the probability of having great market success.« less
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Integration of HTS Cables in the Future Grid of the Netherlands
NASA Astrophysics Data System (ADS)
Zuijderduin, R.; Chevtchenko, O.; Smit, J. J.; Aanhaanen, G.; Melnik, I.; Geschiere, A.
Due to increasing power demand, the electricity grid of the Netherlands is changing. The future transmission grid will obtain electrical power generated by decentralized renewable sources, together with large scale generation units located at the coastal region. In this way electrical power has to be distributed and transmitted over longer distances from generation to end user. Potential grid issues like: amount of distributed power, grid stability and electrical loss dissipation merit particular attention. High temperature superconductors (HTS) can play an important role in solving these grid problems. Advantages to integrate HTS components at transmission voltages are numerous: more transmittable power together with less emissions, intrinsic fault current limiting capability, lower ac loss, better control of power flow, reduced footprint, less magnetic field emissions, etc. The main obstacle at present is the relatively high price of HTS conductor. However as the price goes down, initial market penetration of several HTS components (e.g.: cables, fault current limiters) is expected by year 2015. In the full paper we present selected ways to integrate EHV AC HTS cables depending on a particular future grid scenario in the Netherlands.
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Liu, Changzheng; Oak Ridge National Lab.; Lin, Zhenhong; ...
2016-12-08
Plug-in electric vehicles (PEVs) are widely regarded as an important component of the technology portfolio designed to accomplish policy goals in sustainability and energy security. However, the market acceptance of PEVs in the future remains largely uncertain from today's perspective. By integrating a consumer choice model based on nested multinomial logit and Monte Carlo simulation, this study analyzes the uncertainty of PEV market penetration using Monte Carlo simulation. Results suggest that the future market for PEVs is highly uncertain and there is a substantial risk of low penetration in the early and midterm market. Top factors contributing to market sharemore » variability are price sensitivities, energy cost, range limitation, and charging availability. The results also illustrate the potential effect of public policies in promoting PEVs through investment in battery technology and infrastructure deployment. Here, continued improvement of battery technologies and deployment of charging infrastructure alone do not necessarily reduce the spread of market share distributions, but may shift distributions toward right, i.e., increase the probability of having great market success.« less
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Reside, April E; VanDerWal, Jeremy; Kutt, Alex S
2012-01-01
Identifying the species most vulnerable to extinction as a result of climate change is a necessary first step in mitigating biodiversity decline. Species distribution modeling (SDM) is a commonly used tool to assess potential climate change impacts on distributions of species. We use SDMs to predict geographic ranges for 243 birds of Australian tropical savannas, and to project changes in species richness and ranges under a future climate scenario between 1990 and 2080. Realistic predictions require recognition of the variability in species capacity to track climatically suitable environments. Here we assess the effect of dispersal on model results by using three approaches: full dispersal, no dispersal and a partial-dispersal scenario permitting species to track climate change at a rate of 30 km per decade. As expected, the projected distributions and richness patterns are highly sensitive to the dispersal scenario. Projected future range sizes decreased for 66% of species if full dispersal was assumed, but for 89% of species when no dispersal was assumed. However, realistic future predictions should not assume a single dispersal scenario for all species and as such, we assigned each species to the most appropriate dispersal category based on individual mobility and habitat specificity; this permitted the best estimates of where species will be in the future. Under this “realistic” dispersal scenario, projected ranges sizes decreased for 67% of species but showed that migratory and tropical-endemic birds are predicted to benefit from climate change with increasing distributional area. Richness hotspots of tropical savanna birds are expected to move, increasing in southern savannas and southward along the east coast of Australia, but decreasing in the arid zone. Understanding the complexity of effects of climate change on species’ range sizes by incorporating dispersal capacities is a crucial step toward developing adaptation policies for the conservation of vulnerable species. PMID:22837819
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Barnes, P.R.; Van Dyke, J.W.; McConnell, B.W.
It is estimated that electric utilities use about 40 million distribution transformers in supplying electricity to customers in the United States. Although utility distribution transformers collectively have a high average efficiency, they account for approximately 61 billion kWh of the 229 billion kWh of energy lost annually in the delivery of electricity. Distribution transformers are being replaced over time by new, more efficient, lower-loss units during routine utility maintenance of power distribution systems. Maintenance is typically not performed on units in service. However, units removed from service with appreciable remaining life are often refurbished and returned to stock. Distribution transformersmore » may be removed from service for many reasons, including failure, over- or underloading, or line upgrades such as voltage changes or rerouting. When distribution transformers are removed from service, a decision must be made whether to dispose of the transformer and purchase a lower-loss replacement or to refurbish the transformer and return it to stock for future use. This report contains findings and recommendations on replacing utility distribution transformers during routine maintenance, which is required by section 124(c) of the Energy Policy Act of 1992. The objectives of the study are to evaluate the practicability, cost-effectiveness, and potential energy savings of replacing or upgrading existing transformers during routine utility maintenance and to develop recommendations on was to achieve the potential energy savings.« less
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Robert C. Venette
2013-01-01
Climate change may alter the distribution and activity of native and alien pathogens that infect trees and, in severe cases, cause tree death. In this study, potential future changes in climate suitability are investigated for three forest pathogens that occur in western North America: the native Arceuthobium tsugense subsp tsugense...
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The challenge of modelling and mapping the future distribution and impact of invasive alien species
Robert C. Venette
2015-01-01
Invasions from alien species can jeopardize the economic, environmental or social benefits derived from biological systems. Biosecurity measures seek to protect those systems from accidental or intentional introductions of species that might become injurious. Pest risk maps convey how the probability of invasion by an alien species or the potential consequences of that...
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Nathan Beane; James Rentch
2010-01-01
With the extensive loss of presettlement habitat for red spruce, this species is a high priority for restoration in West Virginia. The advent of climate change caused by human activity and the uncertainty of future environmental changes has also raised interests in the protection and restoration of red spruce ecosystems.
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Climate change poses additional threat to the future of ash resources in the eastern United States
Anantha Prasad; Louis Iverson; Stephen Matthews; Matthew Peters
2010-01-01
It is becoming increasingly clear that climate change has the potential to alter the distribution of plant species all over the world. In the United States, ash (Fraxinus spp.) is encountering the double threat of short-term emerald ash borer (EAB) infestation, which could decimate ash throughout the country, and longer term perturbations due to...
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Risk adjustment model of credit life insurance using a genetic algorithm
NASA Astrophysics Data System (ADS)
Saputra, A.; Sukono; Rusyaman, E.
2018-03-01
In managing the risk of credit life insurance, insurance company should acknowledge the character of the risks to predict future losses. Risk characteristics can be learned in a claim distribution model. There are two standard approaches in designing the distribution model of claims over the insurance period i.e, collective risk model and individual risk model. In the collective risk model, the claim arises when risk occurs is called individual claim, accumulation of individual claim during a period of insurance is called an aggregate claim. The aggregate claim model may be formed by large model and a number of individual claims. How the measurement of insurance risk with the premium model approach and whether this approach is appropriate for estimating the potential losses occur in the future. In order to solve the problem Genetic Algorithm with Roulette Wheel Selection is used.
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Heterogeneous high throughput scientific computing with APM X-Gene and Intel Xeon Phi
Abdurachmanov, David; Bockelman, Brian; Elmer, Peter; ...
2015-05-22
Electrical power requirements will be a constraint on the future growth of Distributed High Throughput Computing (DHTC) as used by High Energy Physics. Performance-per-watt is a critical metric for the evaluation of computer architectures for cost- efficient computing. Additionally, future performance growth will come from heterogeneous, many-core, and high computing density platforms with specialized processors. In this paper, we examine the Intel Xeon Phi Many Integrated Cores (MIC) co-processor and Applied Micro X-Gene ARMv8 64-bit low-power server system-on-a-chip (SoC) solutions for scientific computing applications. As a result, we report our experience on software porting, performance and energy efficiency and evaluatemore » the potential for use of such technologies in the context of distributed computing systems such as the Worldwide LHC Computing Grid (WLCG).« less
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NASA Astrophysics Data System (ADS)
Hernández Vera, Mario; Wester, Roland; Gianturco, Francesco Antonio
2018-01-01
We construct the velocity map images of the proton transfer reaction between helium and molecular hydrogen ion {{{H}}}2+. We perform simulations of imaging experiments at one representative total collision energy taking into account the inherent aberrations of the velocity mapping in order to explore the feasibility of direct comparisons between theory and future experiments planned in our laboratory. The asymptotic angular distributions of the fragments in a 3D velocity space is determined from the quantum state-to-state differential reactive cross sections and reaction probabilities which are computed by using the time-independent coupled channel hyperspherical coordinate method. The calculations employ an earlier ab initio potential energy surface computed at the FCI/cc-pVQZ level of theory. The present simulations indicate that the planned experiments would be selective enough to differentiate between product distributions resulting from different initial internal states of the reactants.
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Future climate effects on suitability for growth of oil palms in Malaysia and Indonesia
Paterson, R. Russell M.; Kumar, Lalit; Taylor, Subhashni; Lima, Nelson
2015-01-01
The production of palm oil (PO) is highly profitable. The economies of the principal producers, Malaysia and Indonesia, and others, benefit considerably. Climate change (CC) will most likely have an impact on the distribution of oil palms (OP) (Elaeis guineensis). Here we present modelled CC projections with respect to the suitability of growing OP, in Malaysia and Indonesia. A process-oriented niche model of OP was developed using CLIMEX to estimate its potential distribution under current and future climate scenarios. Two Global Climate Models (GCMs), CSIRO-Mk3.0 and MIROC-H, were used to explore the impacts of CC under the A1B and A2 scenarios for 2030, 2070 and 2100. Decreases in climatic suitability for OP in the region were gradual by 2030 but became more pronounced by 2100. These projections imply that OP growth will be affected severely by CC, with obvious implications to the economies of (a) Indonesia and Malaysia and (b) the PO industry, but with potential benefits towards reducing CC. A possible remedial action is to concentrate research on development of new varieties of OP that are less vulnerable to CC. PMID:26399638
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Future climate effects on suitability for growth of oil palms in Malaysia and Indonesia.
Paterson, R Russell M; Kumar, Lalit; Taylor, Subhashni; Lima, Nelson
2015-09-24
The production of palm oil (PO) is highly profitable. The economies of the principal producers, Malaysia and Indonesia, and others, benefit considerably. Climate change (CC) will most likely have an impact on the distribution of oil palms (OP) (Elaeis guineensis). Here we present modelled CC projections with respect to the suitability of growing OP, in Malaysia and Indonesia. A process-oriented niche model of OP was developed using CLIMEX to estimate its potential distribution under current and future climate scenarios. Two Global Climate Models (GCMs), CSIRO-Mk3.0 and MIROC-H, were used to explore the impacts of CC under the A1B and A2 scenarios for 2030, 2070 and 2100. Decreases in climatic suitability for OP in the region were gradual by 2030 but became more pronounced by 2100. These projections imply that OP growth will be affected severely by CC, with obvious implications to the economies of (a) Indonesia and Malaysia and (b) the PO industry, but with potential benefits towards reducing CC. A possible remedial action is to concentrate research on development of new varieties of OP that are less vulnerable to CC.
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Feasibility of an integrated X-ray instrument for Mars exobiology and geology. [Abstract only
NASA Technical Reports Server (NTRS)
Fonda, M. L.; Schwartz, D. E.; Koppel, L. N.; Franco, E. D.; Kerner, J. A.
1994-01-01
By employing an integrated X-ray instrument on a future Mars mission, data obtained will greatly augment those returned by Viking; details relevant to the possibility of the origin and evolution of life on Mars will be acquired. An integrated combined X Ray Fluorescence/X Ray Detection (XRF/XRD) instrument has been breadboarded and demonstrated to accommodate important exobiology and geology experiment objectives outlined for Mars Environmental Survey (MESUR) and future Mars missions. Among others, primary objectives for the exploration of Mars include: the intense study of local areas on Mars to 'establish the chemical, mineralogical, and petrological character of different components of the surface material; to determine the distribution, abundance and sources and sinks of volatile materials, including an assessment of the biologic potential, now and during past epochs; and to establish the global chemical and physical characteristics of the Martian surface'. The XRF/XRD breadboard instrument identifies and quantifies soil surface elemental, mineralogical, and petrological characteristics and acquires data necessary to address questions on volatile abundance and distribution. Additionally, the breadboard is able to characterize the biogenic element constituents of soil samples providing information on the biologic potential of the Mars environment.
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Vulnerability of breeding waterbirds to climate change in the Prairie Pothole Region, U.S.A.
Steen, Valerie; Skagen, Susan K; Noon, Barry R
2014-01-01
The Prairie Pothole Region (PPR) of the north-central U.S. and south-central Canada contains millions of small prairie wetlands that provide critical habitat to many migrating and breeding waterbirds. Due to their small size and the relatively dry climate of the region, these wetlands are considered at high risk for negative climate change effects as temperatures increase. To estimate the potential impacts of climate change on breeding waterbirds, we predicted current and future distributions of species common in the PPR using species distribution models (SDMs). We created regional-scale SDMs for the U.S. PPR using Breeding Bird Survey occurrence records for 1971-2011 and wetland, upland, and climate variables. For each species, we predicted current distribution based on climate records for 1981-2000 and projected future distributions to climate scenarios for 2040-2049. Species were projected to, on average, lose almost half their current habitat (-46%). However, individual species projections varied widely, from +8% (Upland Sandpiper) to -100% (Wilson's Snipe). Variable importance ranks indicated that land cover (wetland and upland) variables were generally more important than climate variables in predicting species distributions. However, climate variables were relatively more important during a drought period. Projected distributions of species responses to climate change contracted within current areas of distribution rather than shifting. Given the large variation in species-level impacts, we suggest that climate change mitigation efforts focus on species projected to be the most vulnerable by enacting targeted wetland management, easement acquisition, and restoration efforts.
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NASA Astrophysics Data System (ADS)
Rheuban, Jennie E.; Kavanaugh, Maria T.; Doney, Scott C.
2017-12-01
Sea surface temperatures of the northwest Atlantic have warmed dramatically over the last several decades, while benthic temperatures have increased at a slower pace. Here we analyze a subset of the CMIP5 global Earth system model ensemble using a statistical downscaling approach to determine potential future changes in benthic temperatures on the northwest Atlantic continental shelf and slope (<500 m). We put future changes in the context of possible impacts of ocean warming on the high-value, wild-caught American Lobster (Homarus americanus) fishery. Future bottom temperatures of the northwest Atlantic under a business-as-usual (RCP8.5) and a climate-policy (RCP4.5) scenario are projected to increase by 0-1.5°C and 1.2-2.4°C by 2050 and 0-1.9°C and 2.3-4.3°C by the end of the century for RCP4.5 and RCP8.5, respectively. H. americanus experiences thermal stress at temperatures above 20°C, and projected increases in temperature is likely to result in changes in the distribution of optimal thermal egg hatching and settlement indicators. Inshore regions of southern New England, where H. americanus biomass and catch have been declining historically, will likely become inhospitable under either future scenario, while thermal egg hatching and settlement indicators will expand offshore and in the Gulf of Maine. These changes imply that members of the fishery based in southern New England may need to recapitalize to larger vessels to prepare for potential changes brought on by future climate warming. Results from the downscaling presented here can be useful in preparing for potential changes to other fisheries or in future climate vulnerability analyses.
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Capinha, César; Larson, Eric R; Tricarico, Elena; Olden, Julian D; Gherardi, Francesca
2013-08-01
Climate change will require species to adapt to new conditions or follow preferred climates to higher latitudes or elevations, but many dispersal-limited freshwater species may be unable to move due to barriers imposed by watershed boundaries. In addition, invasive nonnative species may expand into new regions under future climate conditions and contribute to the decline of native species. We evaluated future distributions for the threatened European crayfish fauna in response to climate change, watershed boundaries, and the spread of invasive crayfishes, which transmit the crayfish plague, a lethal disease for native European crayfishes. We used climate projections from general circulation models and statistical models based on Mahalanobis distance to predict climate-suitable regions for native and invasive crayfishes in the middle and at the end of the 21st century. We identified these suitable regions as accessible or inaccessible on the basis of major watershed boundaries and present occurrences and evaluated potential future overlap with 3 invasive North American crayfishes. Climate-suitable areas decreased for native crayfishes by 19% to 72%, and the majority of future suitable areas for most of these species were inaccessible relative to native and current distributions. Overlap with invasive crayfish plague-transmitting species was predicted to increase. Some native crayfish species (e.g., noble crayfish [Astacus astacus]) had no future refugia that were unsuitable for the modeled nonnative species. Our results emphasize the importance of preventing additional introductions and spread of invasive crayfishes in Europe to minimize interactions between the multiple stressors of climate change and invasive species, while suggesting candidate regions for the debatable management option of assisted colonization. © 2013 Society for Conservation Biology.
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NASA Astrophysics Data System (ADS)
Shimizu-Kimura, Yoko; Accad, Arnon; Shapcott, Alison
2017-04-01
Threatened species in rainforests may be vulnerable to climate change, because of their potentially narrow thermal tolerances, small population sizes and restricted distributions. This study modelled climate induced changes on the habitat distribution of the endangered rainforest plant Triunia robusta, endemic to southeast Queensland, Australia. Species distribution models were developed for eastern Australia at 250 m grids and southeast Queensland at 25 m grids using ground-truthed presence records and environmental predictor data. The species’ habitat distribution under the current climate was modelled, and the future potential habitat distributions were projected for the epochs 2030, 2050 and 2070. The eastern Australia model identified several spatially disjunct, broad habitat areas of coastal eastern Australia consistent with the current distribution of rainforests, and projected a southward and upslope contraction driven mainly by average temperatures exceeding current range limits. The southeast Queensland models suggest a dramatic upslope contraction toward locations where the majority of known populations are found. Populations located in the Sunshine Coast hinterland, consistent with past rainforest refugia, are likely to persist long-term. Upgrading the level of protection for less formal nature reserves containing viable populations is a high priority to better protect refugial T. robusta populations with respect to climate change.
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Shimizu-Kimura, Yoko; Accad, Arnon; Shapcott, Alison
2017-01-01
Threatened species in rainforests may be vulnerable to climate change, because of their potentially narrow thermal tolerances, small population sizes and restricted distributions. This study modelled climate induced changes on the habitat distribution of the endangered rainforest plant Triunia robusta, endemic to southeast Queensland, Australia. Species distribution models were developed for eastern Australia at 250 m grids and southeast Queensland at 25 m grids using ground-truthed presence records and environmental predictor data. The species’ habitat distribution under the current climate was modelled, and the future potential habitat distributions were projected for the epochs 2030, 2050 and 2070. The eastern Australia model identified several spatially disjunct, broad habitat areas of coastal eastern Australia consistent with the current distribution of rainforests, and projected a southward and upslope contraction driven mainly by average temperatures exceeding current range limits. The southeast Queensland models suggest a dramatic upslope contraction toward locations where the majority of known populations are found. Populations located in the Sunshine Coast hinterland, consistent with past rainforest refugia, are likely to persist long-term. Upgrading the level of protection for less formal nature reserves containing viable populations is a high priority to better protect refugial T. robusta populations with respect to climate change. PMID:28422136
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Ortega-Andrade, H Mauricio; Prieto-Torres, David A; Gómez-Lora, Ignacio; Lizcano, Diego J
2015-01-01
In Ecuador, Tapirus pinchaque is considered to be critically endangered. Although the species has been registered in several localities, its geographic distribution remains unclear, and the effects of climate change and current land uses on this species are largely unknown. We modeled the ecological niche of T. pinchaque using MaxEnt, in order to assess its potential adaptation to present and future climate change scenarios. We evaluated the effects of habitat loss due by current land use, the ecosystem availability and importance of Ecuadorian System of Protected Areas into the models. The model of environmental suitability estimated an extent of occurrence for species of 21,729 km2 in all of Ecuador, mainly occurring along the corridor of the eastern Ecuadorian Andes. A total of 10 Andean ecosystems encompassed ~98% of the area defined by the model, with herbaceous paramo, northeastern Andean montane evergreen forest and northeastern Andes upper montane evergreen forest being the most representative. When considering the effect of habitat loss, a significant reduction in model area (~17%) occurred, and the effect of climate change represented a net reduction up to 37.86%. However, the synergistic effect of both climate change and habitat loss, given current land use practices, could represent a greater risk in the short-term, leading to a net reduction of 19.90 to 44.65% in T. pinchaque's potential distribution. Even under such a scenarios, several Protected Areas harbor a portion (~36 to 48%) of the potential distribution defined by the models. However, the central and southern populations are highly threatened by habitat loss and climate change. Based on these results and due to the restricted home range of T. pinchaque, its preference for upland forests and paramos, and its small estimated population size in the Andes, we suggest to maintaining its current status as Critically Endangered in Ecuador.
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Ortega-Andrade, H. Mauricio; Prieto-Torres, David A.; Gómez-Lora, Ignacio; Lizcano, Diego J.
2015-01-01
In Ecuador, Tapirus pinchaque is considered to be critically endangered. Although the species has been registered in several localities, its geographic distribution remains unclear, and the effects of climate change and current land uses on this species are largely unknown. We modeled the ecological niche of T. pinchaque using MaxEnt, in order to assess its potential adaptation to present and future climate change scenarios. We evaluated the effects of habitat loss due by current land use, the ecosystem availability and importance of Ecuadorian System of Protected Areas into the models. The model of environmental suitability estimated an extent of occurrence for species of 21,729 km2 in all of Ecuador, mainly occurring along the corridor of the eastern Ecuadorian Andes. A total of 10 Andean ecosystems encompassed ~98% of the area defined by the model, with herbaceous paramo, northeastern Andean montane evergreen forest and northeastern Andes upper montane evergreen forest being the most representative. When considering the effect of habitat loss, a significant reduction in model area (~17%) occurred, and the effect of climate change represented a net reduction up to 37.86%. However, the synergistic effect of both climate change and habitat loss, given current land use practices, could represent a greater risk in the short-term, leading to a net reduction of 19.90 to 44.65% in T. pinchaque’s potential distribution. Even under such a scenarios, several Protected Areas harbor a portion (~36 to 48%) of the potential distribution defined by the models. However, the central and southern populations are highly threatened by habitat loss and climate change. Based on these results and due to the restricted home range of T. pinchaque, its preference for upland forests and paramos, and its small estimated population size in the Andes, we suggest to maintaining its current status as Critically Endangered in Ecuador. PMID:25798851
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Hughes, Joseph D.; Sifuentes, Dorothy F.; White, Jeremy T.
2016-03-15
Model accuracy and use are limited by uncertainty in the physical properties and boundary conditions of the system, uncertainty in historical and future conditions, and generalizations made in the mathematical relationships used to describe the physical processes of groundwater flow and transport. Because of these limitations, model results should be considered in relative rather than absolute terms. Nonetheless, model results do provide useful information on the relative scale of response of the system to changes in pumping distribution, sea-level rise, and mitigation activities.
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Distributed Energy Systems: Security Implications of the Grid of the Future
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stamber, Kevin L.; Kelic, Andjelka; Taylor, Robert A.
2017-01-01
Distributed Energy Resources (DER) are being added to the nation's electric grid, and as penetration of these resources increases, they have the potential to displace or offset large-scale, capital-intensive, centralized generation. Integration of DER into operation of the traditional electric grid requires automated operational control and communication of DER elements, from system measurement to control hardware and software, in conjunction with a utility's existing automated and human-directed control of other portions of the system. Implementation of DER technologies suggests a number of gaps from both a security and a policy perspective. This page intentionally left blank.
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Neutrino mass and dark energy from weak lensing.
Abazajian, Kevork N; Dodelson, Scott
2003-07-25
Weak gravitational lensing of background galaxies by intervening matter directly probes the mass distribution in the Universe. This distribution is sensitive to both the dark energy and neutrino mass. We examine the potential of lensing experiments to measure features of both simultaneously. Focusing on the radial information contained in a future deep 4000 deg(2) survey, we find that the expected (1-sigma) error on a neutrino mass is 0.1 eV, if the dark-energy parameters are allowed to vary. The constraints on dark-energy parameters are similarly restrictive, with errors on w of 0.09.
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Narrow spectral linewidth in InAs/InP quantum dot distributed feedback lasers
NASA Astrophysics Data System (ADS)
Duan, J.; Huang, H.; Lu, Z. G.; Poole, P. J.; Wang, C.; Grillot, F.
2018-03-01
This paper reports on the spectral linewidth of InAs/InP quantum dot distributed feedback lasers. Owing to a low inversion factor and a low linewidth enhancement factor, a narrow spectral linewidth of 160 kHz (80 kHz intrinsic linewidth) with a low sensitivity to temperature is demonstrated. When using anti-reflection coatings on both facets, narrow linewidth operation is extended to high powers, believed to be due to a reduction in the longitudinal spatial hole burning. These results confirm the high potential of quantum dot lasers for increasing transmission capacity in future coherent communication systems.
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Distribution of selected healthcare resources for influenza pandemic response in Cambodia
2013-01-01
Introduction Human influenza infection poses a serious public health threat in Cambodia, a country at risk for the emergence and spread of novel influenza viruses with pandemic potential. Prior pandemics demonstrated the adverse impact of influenza on poor communities in developing countries. Investigation of healthcare resource distribution can inform decisions regarding resource mobilization and investment for pandemic mitigation. Methods A health facility survey performed across Cambodia obtained data on availability of healthcare resources important for pandemic influenza response. Focusing on five key resources considered most necessary for treating severe influenza (inpatient beds, doctors, nurses, oseltamivir, and ventilators), resource distributions were analyzed at the Operational District (OD) and Province levels, refining data analysis from earlier studies. Resources were stratified by respondent type (hospital vs. District Health Office [DHO]). A summary index of distribution inequality was calculated using the Gini coefficient. Indices for local spatial autocorrelation were measured at the OD level using geographical information system (GIS) analysis. Finally, a potential link between socioeconomic status and resource distribution was explored by mapping resource densities against poverty rates. Results Gini coefficient calculation revealed variable inequality in distribution of the five key resources at the Province and OD levels. A greater percentage of the population resides in areas of relative under-supply (28.5%) than over-supply (21.3%). Areas with more resources per capita showed significant clustering in central Cambodia while areas with fewer resources clustered in the northern and western provinces. Hospital-based inpatient beds, doctors, and nurses were most heavily concentrated in areas of the country with the lowest poverty rates; however, beds and nurses in Non-Hospital Medical Facilities (NHMF) showed increasing concentrations at higher levels of poverty. Conclusions There is considerable heterogeneity in healthcare resource distribution across Cambodia. Distribution mapping at the local level can inform policy decisions on where to stockpile resources in advance of and for reallocation in the event of a pandemic. These findings will be useful in determining future health resource investment, both for pandemic preparedness and for general health system strengthening, and provide a foundation for future analyses of equity in health services provision for pandemic mitigation planning in Cambodia. PMID:24090286
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Distribution of selected healthcare resources for influenza pandemic response in Cambodia.
Schwanke Khilji, Sara U; Rudge, James W; Drake, Tom; Chavez, Irwin; Borin, Khieu; Touch, Sok; Coker, Richard
2013-10-04
Human influenza infection poses a serious public health threat in Cambodia, a country at risk for the emergence and spread of novel influenza viruses with pandemic potential. Prior pandemics demonstrated the adverse impact of influenza on poor communities in developing countries. Investigation of healthcare resource distribution can inform decisions regarding resource mobilization and investment for pandemic mitigation. A health facility survey performed across Cambodia obtained data on availability of healthcare resources important for pandemic influenza response. Focusing on five key resources considered most necessary for treating severe influenza (inpatient beds, doctors, nurses, oseltamivir, and ventilators), resource distributions were analyzed at the Operational District (OD) and Province levels, refining data analysis from earlier studies. Resources were stratified by respondent type (hospital vs. District Health Office [DHO]). A summary index of distribution inequality was calculated using the Gini coefficient. Indices for local spatial autocorrelation were measured at the OD level using geographical information system (GIS) analysis. Finally, a potential link between socioeconomic status and resource distribution was explored by mapping resource densities against poverty rates. Gini coefficient calculation revealed variable inequality in distribution of the five key resources at the Province and OD levels. A greater percentage of the population resides in areas of relative under-supply (28.5%) than over-supply (21.3%). Areas with more resources per capita showed significant clustering in central Cambodia while areas with fewer resources clustered in the northern and western provinces. Hospital-based inpatient beds, doctors, and nurses were most heavily concentrated in areas of the country with the lowest poverty rates; however, beds and nurses in Non-Hospital Medical Facilities (NHMF) showed increasing concentrations at higher levels of poverty. There is considerable heterogeneity in healthcare resource distribution across Cambodia. Distribution mapping at the local level can inform policy decisions on where to stockpile resources in advance of and for reallocation in the event of a pandemic. These findings will be useful in determining future health resource investment, both for pandemic preparedness and for general health system strengthening, and provide a foundation for future analyses of equity in health services provision for pandemic mitigation planning in Cambodia.
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An Introduction to the Blockchain and Its Implications for Libraries and Medicine.
Hoy, Matthew B
2017-01-01
The blockchain is a relatively new technology used to verify and store transaction records for online cryptocurrencies like Bitcoin. The system is redundant and distributed, making it difficult for transactions to be rescinded, duplicated, or faked. Beyond online currencies, the blockchain has potential uses in health care, education, and many other fields. This column will briefly describe what the blockchain is and how it is being used, potential future uses that may be of interest to librarians and medical practitioners, and some of the problems with the system.
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Bharti, Himender; Guénard, Benoit; Bharti, Meenakshi; Economo, Evan P.
2016-01-01
Abstract As one of the 17 megadiverse countries of the world and with four biodiversity hotspots represented in its borders, India is home to an impressive diversity of life forms. However, much work remains to document and catalogue the species of India and their geographic distributions, especially for diverse invertebrate groups. In the present study, a comprehensive and critical list of Indian ant species is provided with up-to-date state-wise distribution. A total of 828 valid species and subspecies names belonging to 100 genera are listed from India. Potential erroneous data, misidentifications and dubious distributional records that may exist in the literature are also identified. The present exhaustive listing of Indian ants will provide a holistic view about diversity and distribution and will also help to identify major undersampled areas where future sampling and taxonomic efforts should be directed. PMID:26877665
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NASA Technical Reports Server (NTRS)
1980-01-01
Present and future relatively small (30 MW) energy systems, such as solar thermal electric, photovoltaic, wind, fuel cell, storage battery, hydro, and cogeneration can help achieve national energy goals and can be dispersed throughout the distribution portion of an electric utility system. Based on current projections, it appears that dispersed storage and generation (DSG) electrical energy will comprise only a small portion, from 4 to 10 percent, of the national total by the end of this century. In general, the growth potential for DSG seems favorable in the long term because of finite fossil energy resources and increasing fuel prices. Recent trends, especially in the institutional and regulatory fields, favor greater use of the DSGs for the future.
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NASA Astrophysics Data System (ADS)
1980-10-01
Present and future relatively small (30 MW) energy systems, such as solar thermal electric, photovoltaic, wind, fuel cell, storage battery, hydro, and cogeneration can help achieve national energy goals and can be dispersed throughout the distribution portion of an electric utility system. Based on current projections, it appears that dispersed storage and generation (DSG) electrical energy will comprise only a small portion, from 4 to 10 percent, of the national total by the end of this century. In general, the growth potential for DSG seems favorable in the long term because of finite fossil energy resources and increasing fuel prices. Recent trends, especially in the institutional and regulatory fields, favor greater use of the DSGs for the future.
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Năpăruş, Magdalena; Kuntner, Matjaž
2012-01-01
Although numerous studies model species distributions, these models are almost exclusively on single species, while studies of evolutionary lineages are preferred as they by definition study closely related species with shared history and ecology. Hermit spiders, genus Nephilengys, represent an ecologically important but relatively species-poor lineage with a globally allopatric distribution. Here, we model Nephilengys global habitat suitability based on known localities and four ecological parameters. We geo-referenced 751 localities for the four most studied Nephilengys species: N. cruentata (Africa, New World), N. livida (Madagascar), N. malabarensis (S-SE Asia), and N. papuana (Australasia). For each locality we overlaid four ecological parameters: elevation, annual mean temperature, annual mean precipitation, and land cover. We used linear backward regression within ArcGIS to select two best fit parameters per species model, and ModelBuilder to map areas of high, moderate and low habitat suitability for each species within its directional distribution. For Nephilengys cruentata suitable habitats are mid elevation tropics within Africa (natural range), a large part of Brazil and the Guianas (area of synanthropic spread), and even North Africa, Mediterranean, and Arabia. Nephilengys livida is confined to its known range with suitable habitats being mid-elevation natural and cultivated lands. Nephilengys malabarensis, however, ranges across the Equator throughout Asia where the model predicts many areas of high ecological suitability in the wet tropics. Its directional distribution suggests the species may potentially spread eastwards to New Guinea where the suitable areas of N. malabarensis largely surpass those of the native N. papuana, a species that prefers dry forests of Australian (sub)tropics. Our model is a customizable GIS tool intended to predict current and future potential distributions of globally distributed terrestrial lineages. Its predictive potential may be tested in foreseeing species distribution shifts due to habitat destruction and global climate change.
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Năpăruş, Magdalena; Kuntner, Matjaž
2012-01-01
Background Although numerous studies model species distributions, these models are almost exclusively on single species, while studies of evolutionary lineages are preferred as they by definition study closely related species with shared history and ecology. Hermit spiders, genus Nephilengys, represent an ecologically important but relatively species-poor lineage with a globally allopatric distribution. Here, we model Nephilengys global habitat suitability based on known localities and four ecological parameters. Methodology/Principal Findings We geo-referenced 751 localities for the four most studied Nephilengys species: N. cruentata (Africa, New World), N. livida (Madagascar), N. malabarensis (S-SE Asia), and N. papuana (Australasia). For each locality we overlaid four ecological parameters: elevation, annual mean temperature, annual mean precipitation, and land cover. We used linear backward regression within ArcGIS to select two best fit parameters per species model, and ModelBuilder to map areas of high, moderate and low habitat suitability for each species within its directional distribution. For Nephilengys cruentata suitable habitats are mid elevation tropics within Africa (natural range), a large part of Brazil and the Guianas (area of synanthropic spread), and even North Africa, Mediterranean, and Arabia. Nephilengys livida is confined to its known range with suitable habitats being mid-elevation natural and cultivated lands. Nephilengys malabarensis, however, ranges across the Equator throughout Asia where the model predicts many areas of high ecological suitability in the wet tropics. Its directional distribution suggests the species may potentially spread eastwards to New Guinea where the suitable areas of N. malabarensis largely surpass those of the native N. papuana, a species that prefers dry forests of Australian (sub)tropics. Conclusions Our model is a customizable GIS tool intended to predict current and future potential distributions of globally distributed terrestrial lineages. Its predictive potential may be tested in foreseeing species distribution shifts due to habitat destruction and global climate change. PMID:22238692
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Assessing distributions of two invasive species of contrasting habits in future climate.
Panda, Rajendra Mohan; Behera, Mukunda Dev; Roy, Partha Sarathi
2018-05-01
Understanding the impact of climate change on species invasion is crucial for sustainable biodiversity conservation. Through this study, we try to answer how species differing in phenological cycles, specifically Cassia tora and Lantana camara, differ in the manner in which they invade new regions in India in the future climate. Since both species occupy identical niches, exploring their invasive potential in different climate change scenarios will offer critical insights into invasion and inform ecosystem management. We use three modelling protocols (i.e., maximum entropy, generalised linear model and generalised additive model) to predict the current distribution. Projections are made for both moderate (A1B) and extreme (A2) IPCC (Intergovernmental Panel on Climate Change) scenarios for the year 2050 and 2100. The study reveals that the distributions of C. tora (annual) and L. camara (perennial) would depend on the precipitation of the warmest quarter and moisture availability. C. tora may demonstrate physiological tolerance to the mean diurnal temperature range and L. camara to the solar radiation. C. tora may invade central India, while L. camara may invade the Western Himalaya, parts of the Eastern Himalaya and the Western Ghats. The distribution ranges of both species could shift in the northern and north-eastern directions in India, owing to changes in moisture availability. The possible alterations in precipitation regimes could lead to water stress, which might have cascading effects on species invasion. L. camara might adapt to climate change better compared with C. tora. This comparative analysis of the future distributions of two invasive plants with contrasting habits demonstrates that temporal complementarity would prevail over the competition. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Saltré, Frédérik; Duputié, Anne; Gaucherel, Cédric; Chuine, Isabelle
2015-02-01
Recent efforts to incorporate migration processes into species distribution models (SDMs) are allowing assessments of whether species are likely to be able to track their future climate optimum and the possible causes of failing to do so. Here, we projected the range shift of European beech over the 21st century using a process-based SDM coupled to a phenomenological migration model accounting for population dynamics, according to two climate change scenarios and one land use change scenario. Our model predicts that the climatically suitable habitat for European beech will shift north-eastward and upward mainly because (i) higher temperature and precipitation, at the northern range margins, will increase survival and fruit maturation success, while (ii) lower precipitations and higher winter temperature, at the southern range margins, will increase drought mortality and prevent bud dormancy breaking. Beech colonization rate of newly climatically suitable habitats in 2100 is projected to be very low (1-2% of the newly suitable habitats colonised). Unexpectedly, the projected realized contraction rate was higher than the projected potential contraction rate. As a result, the realized distribution of beech is projected to strongly contract by 2100 (by 36-61%) mainly due to a substantial increase in climate variability after 2050, which generates local extinctions, even at the core of the distribution, the frequency of which prevents beech recolonization during more favourable years. Although European beech will be able to persist in some parts of the trailing edge of its distribution, the combined effects of climate and land use changes, limited migration ability, and a slow life-history are likely to increase its threat status in the near future. © 2014 John Wiley & Sons Ltd.
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Potential Impact of the National Plan for Future Electric Power Supply on Air Quality in Korea
NASA Astrophysics Data System (ADS)
Shim, C.; Hong, J.
2014-12-01
Korean Ministry of Trade, Industry and Energy (MOTIE) announced the national plan for Korea's future electric power supply (2013 - 2027) in 2013. According to the plan, the national demand for electricity will be increased by 60% compared to that of 2010 and primary energy sources for electric generation will still lean on the fossil fuels such as petroleum, LNG, and coal, which would be a potential threat to air quality of Korea. This study focused on two subjects: (1) How the spatial distribution of the primary air pollutant's emissions (i.e., NOx, SOx, CO, PM) will be changed and (2) How the primary emission changes will influence on the national ambient air quality including ozone in 2027. We used GEOS-Chem model simulation with modification of Korean emissions inventory (Clean Air Policy Support System (CAPSS)) to simulate the current and future air quality in Korea. The national total emissions of CO, NOx, SOx, PM in year 2027 will be increased by 3%, 8%, 13%, 2%, respectively compared to 2010 and there are additional concern that the future location of the power plants will be closer to the Seoul Metropolitan Area (SMA), where there are approximately 20 million population vulnerable to the potentially worsened air quality. While there are slight increase of concentration of CO, NOx, SOx, and PM in 2027, the O3 concentration is expected to be similar to the level of 2010. Those results may imply the characteristics of air pollution in East Asia such as potentially severe O3 titration and poorer O3/CO or O3/NOx ratio. Furthermore, we will discuss on the impact of transboundary pollution transport from China in the future, which is one of the large factors to control the air quality of Korea.
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Current and future effects of global change on a hotspot's freshwater diversity.
Gallardo, Belinda; Bogan, Arthur E; Harun, Sahana; Jainih, Leonardo; Lopes-Lima, Manuel; Pizarro, Manuel; Rahim, Khairul Adha; Sousa, Ronaldo; Virdis, Salvatore G P; Zieritz, Alexandra
2018-04-19
Deforestation, climate change and invasive species constitute three global threats to biodiversity that act synergistically. However, drivers and rates of loss of freshwater biodiversity now and in the future are poorly understood. Here we focus on the potential impacts of global change on freshwater mussels (Order Unionida) in Sundaland (SE Asia), a vulnerable group facing global declines and recognized indicators of overall freshwater biodiversity. We used an ensemble of distribution models to identify habitats potentially suitable for freshwater mussels and their change under a range of climate, deforestation and invasion scenarios. Our data and models revealed that, at present, Sundaland features 47 and 32 Mha of habitat that can be considered environmentally suitable for native and invasive freshwater mussels, respectively. We anticipate that by 2050, the area suitable for palm oil cultivation may expand between 8 and 44 Mha, representing an annual increase of 2-11%. This is expected to result in a 20% decrease in suitable habitat for native mussels, a drop that reaches 30% by 2050 when considering concomitant climate change. In contrast, the habitat potentially suitable for invasive mussels may increase by 44-56% under 2050 future scenarios. Consequently, native mussels may compete for habitat, food resources and fish hosts with invasive mussels across approximately 60% of their suitable range. Our projections can be used to guide future expeditions to monitor the conservation status of freshwater biodiversity, and potentially reveal populations of endemic species on the brink of extinction. Future conservation measures-most importantly the designation of nature reserves-should take into account trends in freshwater biodiversity generally, and particularly species such as freshwater mussels, vital to safeguard fundamental ecosystem services. Copyright © 2018 Elsevier B.V. All rights reserved.
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Robinson, Jason L; Fordyce, James A
2017-01-01
Among the greatest challenges facing the conservation of plants and animal species in protected areas are threats from a rapidly changing climate. An altered climate creates both challenges and opportunities for improving the management of protected areas in networks. Increasingly, quantitative tools like species distribution modeling are used to assess the performance of protected areas and predict potential responses to changing climates for groups of species, within a predictive framework. At larger geographic domains and scales, protected area network units have spatial geoclimatic properties that can be described in the gap analysis typically used to measure or aggregate the geographic distributions of species (stacked species distribution models, or S-SDM). We extend the use of species distribution modeling techniques in order to model the climate envelope (or "footprint") of individual protected areas within a network of protected areas distributed across the 48 conterminous United States and managed by the US National Park System. In our approach we treat each protected area as the geographic range of a hypothetical endemic species, then use MaxEnt and 5 uncorrelated BioClim variables to model the geographic distribution of the climatic envelope associated with each protected area unit (modeling the geographic area of park units as the range of a species). We describe the individual and aggregated climate envelopes predicted by a large network of 163 protected areas and briefly illustrate how macroecological measures of geodiversity can be derived from our analysis of the landscape ecological context of protected areas. To estimate trajectories of change in the temporal distribution of climatic features within a protected area network, we projected the climate envelopes of protected areas in current conditions onto a dataset of predicted future climatic conditions. Our results suggest that the climate envelopes of some parks may be locally unique or have narrow geographic distributions, and are thus prone to future shifts away from the climatic conditions in these parks in current climates. In other cases, some parks are broadly similar to large geographic regions surrounding the park or have climatic envelopes that may persist into near-term climate change. Larger parks predict larger climatic envelopes, in current conditions, but on average the predicted area of climate envelopes are smaller in our single future conditions scenario. Individual units in a protected area network may vary in the potential for climate adaptation, and adaptive management strategies for the network should account for the landscape contexts of the geodiversity or climate diversity within individual units. Conservation strategies, including maintaining connectivity, assessing the feasibility of assisted migration and other landscape restoration or enhancements can be optimized using analysis methods to assess the spatial properties of protected area networks in biogeographic and macroecological contexts.
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NASA Astrophysics Data System (ADS)
Wallace, M. G.; Iuzzolina, H.
2005-12-01
A probabilistic analysis was conducted to estimate ranges for the numbers of waste packages that could be damaged in a potential future igneous event through a repository at Yucca Mountain. The analysis includes disruption from an intrusive igneous event and from an extrusive volcanic event. This analysis supports the evaluation of the potential consequences of future igneous activity as part of the total system performance assessment for the license application for the Yucca Mountain Project (YMP). The first scenario, igneous intrusion, investigated the case where one or more igneous dikes intersect the repository. A swarm of dikes was characterized by distributions of length, width, azimuth, and number of dikes and the spacings between them. Through the use in part of a latin hypercube simulator and a modified video game engine, mathematical relationships were built between those parameters and the number of waste packages hit. Corresponding cumulative distribution function curves (CDFs) for the number of waste packages hit under several different scenarios were calculated. Variations in dike thickness ranges, as well as in repository magma bulkhead positions were examined through sensitivity studies. It was assumed that all waste packages in an emplacement drift would be impacted if that drift was intersected by a dike. Over 10,000 individual simulations were performed. Based on these calculations, out of a total of over 11,000 planned waste packages distributed over an area of approximately 5.5 km2 , the median number of waste packages impacted was roughly 1/10 of the total. Individual cases ranged from 0 waste packages to the entire inventory being impacted. The igneous intrusion analysis involved an explicit characterization of dike-drift intersections, built upon various distributions that reflect the uncertainties associated with the inputs. The second igneous scenario, volcanic eruption (eruptive conduits), considered the effects of conduits formed in association with a volcanic eruption through the repository. Mathematical relations were built between the resulting conduit areas and the fraction of the repository area occupied by waste packages. This relation was used in conjunction with a joint distribution incorporating variability in eruptive conduit diameters and in the number of eruptive conduits that could intersect the repository.
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National-level long-term eruption forecasts by expert elicitation
NASA Astrophysics Data System (ADS)
Bebbington, Mark S.; Stirling, Mark W.; Cronin, Shane; Wang, Ting; Jolly, Gill
2018-06-01
Volcanic hazard estimation is becoming increasingly quantitative, creating the potential for land-use decisions and engineering design to use volcanic information in an analogous manner to seismic codes. The initial requirement is to characterize the possible hazard sources, quantifying the likely timing, magnitude and location of the next eruption in each case. This is complicated by the extremely different driving processes at individual volcanoes, and incomplete and uneven records of past activity at various volcanoes. To address these issues, we carried out an expert elicitation approach to estimate future eruption potential for 12 volcanoes of interest in New Zealand. A total of 28 New Zealand experts provided estimates that were combined using Cooke's classical method to arrive at a hazard estimate. In 11 of the 12 cases, the elicited eruption duration increased with VEI, and was correlated with expected repose, differing little between volcanoes. Most of the andesitic volcanoes had very similar elicited distributions for the VEI of a future eruption, except that Taranaki was expected to produce a larger eruption, due to the current long repose. Elicited future vent locations for Tongariro and Okataina reflect strongly the most recent eruptions. In the poorly studied Bay of Islands volcanic field, the estimated vent location distribution was centred on the centroid of the previous vent locations, while in the Auckland field, it was focused on regions within the field without past eruptions. The elicited median dates for the next eruptions ranged from AD2022 (Whakaari/White Island) to AD4390 (Tuhua/Mayor Island).
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Zhang, Chun Peng; Li, Fu Xiang
2016-09-01
Kriging interpolation analysis was conducted with ArcGIS to find out the distribution characteristics of heavy metals concentrations in the surface sediments of the coastal wetland mudflat on the Yalu River estuary, environmental risk index and Hakanson potential ecological risk index were used to assess their extents of pollution in this area.The concentrations of heavy metals in the surface sediments of the study area were at a relatively high level compared with the typical estuarine wetland. The concentration of heavy metals in the east was higher than that in the west, and in the human activity area, the concentration was higher. Cu was found to contribute the most to the pollution status based on environmental risk index method, while Hg and Cd produced the greatest potential ecological harm according to Hankanson Potential ecological risk index method. The average potential ecological risk index (RI) of the Yalu River estuary wetland was 189.30 (ranged from 93.65-507.20), suggesting a moderate ecological risk. However, the potential ecological risk was highest in the east and should be treated as the major heavy metal pollution prevention area in the future.
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Ethics, Nanobiosensors and Elite Sport: The Need for a New Governance Framework.
Evans, Robert; McNamee, Michael; Guy, Owen
2017-12-01
Individual athletes, coaches and sports teams seek continuously for ways to improve performance and accomplishment in elite competition. New techniques of performance analysis are a crucial part of the drive for athletic perfection. This paper discusses the ethical importance of one aspect of the future potential of performance analysis in sport, combining the field of biomedicine, sports engineering and nanotechnology in the form of 'Nanobiosensors'. This innovative technology has the potential to revolutionise sport, enabling real time biological data to be collected from athletes that can be electronically distributed. Enabling precise real time performance analysis is not without ethical problems. Arguments concerning (1) data ownership and privacy; (2) data confidentiality; and (3) athlete welfare are presented alongside a discussion of the use of the Precautionary Principle in making ethical evaluations. We conclude, that although the future potential use of Nanobiosensors in sports analysis offers many potential benefits, there is also a fear that it could be abused at a sporting system level. Hence, it is essential for sporting bodies to consider the development of a robust ethically informed governance framework in advance of their proliferated use.
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NASA Astrophysics Data System (ADS)
Ramirez-Cabral, Nadiezhda Yakovleva Zitz; Kumar, Lalit; Shabani, Farzin
2018-01-01
Worldwide, crop pests (CPs) such as pathogens and insects affect agricultural production detrimentally. Species distribution models can be used for projecting current and future suitability of CPs and host crop localities. Our study overlays the distribution of two CPs (Asian soybean rust and beet armyworm) and common bean, a potential host of them, in order to determine their current and future levels of coexistence. This kind of modeling approach has rarely been performed previously in climate change studies. The soybean rust and beet armyworm model projections herein show a reduction of the worldwide area with high and medium suitability of both CPs and a movement of them away from the Equator, in 2100 more pronounced than in 2050. Most likely, heat and dry stress will be responsible for these changes. Heat and dry stress will greatly reduce and shift the future suitable cultivation area of common bean as well, in a similar manner. The most relevant findings of this study were the reduction of the suitable areas for the CPs, the reduction of the risk under future scenarios, and the similarity of trends for the CPs and host. The current results highlight the relation between and the coevolution of host and pathogens.
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Woody plants and the prediction of climate-change impacts on bird diversity.
Kissling, W D; Field, R; Korntheuer, H; Heyder, U; Böhning-Gaese, K
2010-07-12
Current methods of assessing climate-induced shifts of species distributions rarely account for species interactions and usually ignore potential differences in response times of interacting taxa to climate change. Here, we used species-richness data from 1005 breeding bird and 1417 woody plant species in Kenya and employed model-averaged coefficients from regression models and median climatic forecasts assembled across 15 climate-change scenarios to predict bird species richness under climate change. Forecasts assuming an instantaneous response of woody plants and birds to climate change suggested increases in future bird species richness across most of Kenya whereas forecasts assuming strongly lagged woody plant responses to climate change indicated a reversed trend, i.e. reduced bird species richness. Uncertainties in predictions of future bird species richness were geographically structured, mainly owing to uncertainties in projected precipitation changes. We conclude that assessments of future species responses to climate change are very sensitive to current uncertainties in regional climate-change projections, and to the inclusion or not of time-lagged interacting taxa. We expect even stronger effects for more specialized plant-animal associations. Given the slow response time of woody plant distributions to climate change, current estimates of future biodiversity of many animal taxa may be both biased and too optimistic.
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ERIC Educational Resources Information Center
Onsman, Andrys
2012-01-01
The dichotomous interpretation of the assumed growth and normalisation of English as the lingua franca (ELF) of the international academy is most often polarised into a marginalisation of non-native speakers by the hegemony of native speakers on the one hand and the empowerment and upward mobility created by its potential to afford access to the…
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ERIC Educational Resources Information Center
Iams, Howard M.; Reznik, Gayle L.; Tamborini, Christopher R.
2010-01-01
Purpose: As part of an ongoing effort to analyze the distributional implications of potential policy reforms to the U.S. Social Security system, we consider the widely discussed reform of earnings sharing. Such an approach has been viewed as a way to "update" Social Security's family benefits based on marital status and as a means to…
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Linking interseismic deformation with coseismic slip using dynamic rupture simulations
NASA Astrophysics Data System (ADS)
Yang, H.; He, B.; Weng, H.
2017-12-01
The largest earthquakes on earth occur at subduction zones, sometimes accompanied by devastating tsunamis. Reducing losses from megathrust earthquakes and tsunami demands accurate estimate of rupture scenarios for future earthquakes. Interseismic locking distribution derived from geodetic observations is often used to qualitatively evaluate future earthquake potential. However, how to quantitatively estimate the coseismic slip from the locking distribution remains challenging. Here we derive the coseismic rupture process of the 2012 Mw 7.6 Nicoya, Costa Rica, earthquake from interseismic locking distribution using spontaneous rupture simulation. We construct a three-dimensional elastic medium with a curved fault, which is governed by the linear slip-weakening law. The initial stress on the fault is set based on the build-up stress inferred from locking and the dynamic friction coefficient from fast-speed sliding experiments. Our numerical results of coseismic slip distribution, moment rate function and final earthquake moment are well consistent with those derived from seismic and geodetic observations. Furthermore, we find that the epicentral locations affect rupture scenarios and may lead to various sizes of earthquakes given the heterogeneous stress distribution. In the Nicoya region, less than half of rupture initiation regions where the locking degree is greater than 0.6 can develop into large earthquakes (Mw > 7.2). The results of location-dependent earthquake magnitudes underscore the necessity of conducting a large number of simulations to quantitatively evaluate seismic hazard from the interseismic locking models.
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Takano, Kohei Takenaka; Hibino, Kenshi; Numata, Ayaka; Oguro, Michio; Aiba, Masahiro; Shiogama, Hideo; Takayabu, Izuru; Nakashizuka, Tohru
2017-12-01
Rapid expansion of exotic bamboos has lowered species diversity in Japan's ecosystems by hampering native plant growth. The invasive potential of bamboo, facilitated by global warming, may also affect other countries with developing bamboo industries. We examined past (1975-1980) and recent (2012) distributions of major exotic bamboos ( Phyllostachys edulis and P. bambusoides ) in areas adjacent to 145 weather stations in central and northern Japan. Bamboo stands have been established at 17 sites along the latitudinal and altitudinal distributional limit during the last three decades. Ecological niche modeling indicated that temperature had a strong influence on bamboo distribution. Using mean annual temperature and sun radiation data, we reproduced bamboo distribution (accuracy = 0.93 and AUC (area under the receiver operating characteristic curve) = 0.92). These results infer that exotic bamboo distribution has shifted northward and upslope, in association with recent climate warming. Then, we simulated future climate data and projected the climate change impact on the potential habitat distribution of invasive bamboos under different temperature increases (i.e., 1.5°C, 2.0°C, 3.0°C, and 4.0°C) relative to the preindustrial period. Potential habitats in central and northern Japan were estimated to increase from 35% under the current climate (1980-2000) to 46%-48%, 51%-54%, 61%-67%, and 77%-83% under 1.5°C, 2.0°C, 3.0°C, and 4.0°C warming levels, respectively. These infer that the risk areas can increase by 1.3 times even under a 1.5°C scenario and expand by 2.3 times under a 4.0°C scenario. For sustainable ecosystem management, both mitigation and adaptation are necessary: bamboo planting must be carefully monitored in predicted potential habitats, which covers most of Japan.
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Formoso, Anahí E.; Martin, Gabriel M.; Teta, Pablo; Carbajo, Aníbal E.; Sauthier, Daniel E. Udrizar; Pardiñas, Ulyses F. J.
2015-01-01
The Patagonian opossum (Lestodelphys halli), the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32°S and ~49°S). Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic “space” currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future. PMID:26203650
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Vinnemeier, C D; Brust, P; Owusu-Dabo, E; Sarpong, N; Sarfo, E Y; Bio, Y; Rolling, T; Dekker, D; Adu-Sarkodie, Y; Eberhardt, K A; May, J; Cramer, J P
2015-11-01
Group B streptococcal (GBS) colonization of pregnant women can lead to subsequent infection of the new-born and potentially fatal invasive disease. Data on GBS colonization prevalence and serotype distribution from Africa are scarce, although GBS-related infections are estimated to contribute substantially to infant mortality. In recent years, GBS vaccine candidates provided promising results in phase I and II clinical trials. We aimed to assess the prevalence and serotype distribution of GBS in Ghana since this knowledge is a prerequisite for future evaluation of vaccine trials. This double-centre study was conducted in one rural and one urban hospital in central Ghana, West Africa. Women in late pregnancy (≥35 weeks of gestation) attending the antenatal care clinic (ANC) provided recto-vaginal swabs for GBS testing. GBS isolates were analysed for serotype and antibiotic susceptibility. GBS-positive women were treated with intrapartum antibiotic prophylaxis (IAP) according to current guidelines of the Center for Disease Control and Prevention (CDC). In total, 519 women were recruited at both study sites, recto-vaginal swabs were taken from 509. The overall prevalence of GBS was 19.1% (18.1% in rural Pramso and 23.1% in urban Kumasi, restrospectively). Capsular polysaccharide serotype (CPS) Ia accounted for the most frequent serotype beyond all isolates (28.1%), followed by serotype V (27.1%) and III (21.9%). No resistance to Penicillin was found, resistances to second line antibiotics clindamycin and erythromycin were 3.1% and 1%, respectively. Group B Streptococcus serotype distribution in Ghana is similar to that worldwide, but variations in prevalence of certain serotypes between the urban and rural study site were high. Antibiotic resistance of GBS strains was surprisingly low in this study. © 2015 John Wiley & Sons Ltd.
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NASA Astrophysics Data System (ADS)
González-Carrasco, J. F.
2016-12-01
Southern Peru and northern Chile coastal areas, extended between 12º to 24ºS, have been recognized as a mature seismic gap with a high seismogenic potential associated to seismic moment deficit accumulated since 1877. An important scientific question is which will be the breaking pattern of a future megathrust earthquake, being relevant from hazard assessment perspective. During the last decade, the occurrence of three major subduction earthquakes has given the possibility to acquire outstanding geophysical and geological information to know the behavior of phenomena. An interesting result is the relationship between the maximum slip areas and the spatial distribution of asperities in subduction zones. In this contribution, we propose a methodology to identify a regional pattern of main asperities to construct reliable seismogenic scenarios in a seismic gap. We follow a deterministic approach to explore the distribution of asperities segmentation using geophysical and geodetic data as trench-parallel gravity anomaly (TPGA), interseismic coupling (ISC), b-value, historical moment release, residual bathymetric and gravity anomalies. The combined information represents physical constraints for short and long term suitable regions for future mega earthquakes. To illuminate the asperities distribution, we construct profiles using fault coordinates, along-strike and down-dip direction, of all proxies to define the boundaries of a major asperities (> 100 km). The geometry of a major asperity is useful to define a finite set of future deterministic seismogenic scenarios to evaluate tsunamigenic hazard in main cities of northern zone of Chile (18°S to 24°S).
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Fire and climate suitability for woody vegetation communities in the south central United States
Stroh, Esther; Struckhoff, Matthew; Stambaugh, Michael C.; Guyette, Richard P.
2018-01-01
using a physical chemistry fire frequency model. We then used the fire probability data with additional climate parameters to construct maximum entropy environmental suitability models for three south central US vegetation communities. The modeled communities included an oak type (dominated by post oak, Quercus stellata Wangenh., and blackjack oak, Q. marilandica Münchh.), a mesquite type (dominated by honey mesquite, Prosopis glandulosa Torr., and velvet mesquite, P. velutina Wooton), and a pinyon−juniper type (dominated by pinyon pine, Pinus edulis Engelm., and Utah juniper, Juniperus osteosperma [Torr.] Little). We mapped baseline and future mean fire-climate suitability using data from three global climate models for 2040 to 2069 and 2070 to 2099; we also mapped future locations of threshold conditions for which all three models agreed on suitability for each community. Future projections included northward, southward, and eastward shifts in suitable conditions for the oaks along a broad path of fire-climate stability; an overall reduction in suitable area for historic mesquite communities coupled with potential expansion to new areas; and constriction and isolation of suitable conditions for pinyon−juniper communities. The inclusion of fire probability adds an important driver of vegetation distribution to climate envelope modeling. The simple models showed good fit, but future projections failed to account for future management activities or land use changes. Results provided information on potential future de-coupling and spatial re-arrangement of environmental conditions under which these communities have historically persisted and been managed. In particular, consensus threshold maps can inform long-term planning for maintenance or restoration of these communities, and they can be used as a potential tool for other communities in fire-prone environments within the study area and beyond its borders.
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NASA Astrophysics Data System (ADS)
Pellizzaro, Grazia; Dubrovsky, Martin; Bortolu, Sara; Ventura, Andrea; Arca, Bachisio; Masia, Pierpaolo; Duce, Pierpaolo
2014-05-01
Mediterranean shrubs are an important component of both Mediterranean vegetation communities and understorey vegetation. They also constitute the surface fuels primarily responsible for the ignition and the spread of wildland fires in Mediterranean forests. Although fire spread and behaviour are dependent on several factors, the water content of live fuel plays an important role in determining fire occurrence and spread, especially in the Mediterranean shrubland, where live fuel is often the main component of the available fuel which catches fire. According to projections on future climate, an increase in risk of summer droughts is likely to take place in Southern Europe. More prolonged drought seasons induced by climatic changes are likely to influence general flammability characteristics of fuel, affecting load distribution in vegetation strata, floristic composition, and live and dead fuel ratio. In addition, variations in precipitation and mean temperature could directly affect fuel water status, and consequently flammability, and length of critical periods of high ignition danger for Mediterranean ecosystems. The main aim of this work was to propose a methodology for evaluating possible impacts of future climate change on moisture dynamic and length of fire danger period at local scale. Specific objectives were: i) evaluating performances of meteorological drought indices in describing seasonal pattern of live fuel moisture content (LFMC), and ii) simulating the potential impacts of future climate changes on the duration of fire danger period. Measurements of LFMC seasonal pattern of three Mediterranean shrub species were performed in North Western Sardinia (Italy) for 8 years. Seasonal patterns of LFMC were compared with the Drought Code of the Canadian Forest Fire Weather Index and the Keetch-Byram Drought Index. Analysis of frequency distribution and cumulative distribution curves were carried out in order to evaluate performance of codes and to identify threshold values of indices useful to determine the end of the potential fire season due to fuel status. A weather generator linked to climate change scenarios derived from 17 available General Circulation Models (GCMs) was used to produce synthetic weather series, representing present and future climates, for four selected sites located in North Sardinia, Italy. Finally, impacts of future climate change on fire season length at local scale were simulated. Results confirmed that the projected climate scenarios over the Mediterranean area will determine an overall increase of the fire season length.
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How climate change might influence the potential distribution of weed, bushmint (Hyptis suaveolens)?
Padalia, Hitendra; Srivastava, Vivek; Kushwaha, S P S
2015-04-01
Invasive species and climate change are considered as the most serious global environmental threats. In this study, we investigated the influence of projected global climate change on the potential distribution of one of the world's most successful invader weed, bushmint (Hyptis suaveolens (L.) Poit.). We used spatial data on 20 environmental variables at a grid resolution of 5 km, and 564 presence records of bushmint from its native and introduced range. The climatic profiles of the native and invaded sites were analyzed in a multi-variate space in order to examine the differences in the position of climatic niches. Maximum Entropy (MaxEnt) model was used to predict the potential distribution of bushmint using presence records from entire range (invaded and native) along with 14 eco-physiologically relevant predictor variables. Subsequently, the trained MaxEnt model was fed with Hadley Centre Coupled Model (HadCM3) climate projections to predict potential distribution of bushmint by the year 2050 under A2a and B2a emission scenarios. MaxEnt predictions were very accurate with an Area Under Curve (AUC) value of 0.95. The results of Principal Component Analysis (PCA) indicated that climatic niche of bushmint on the invaded sites is not entirely similar to its climatic niche in the native range. A vast area spread between 34 ° 02' north and 28 ° 18' south latitudes in tropics was predicted climatically suitable for bushmint. West and middle Africa, tropical southeast Asia, and northern Australia were predicted at high invasion risk. Study indicates enlargement, retreat, or shift across bushmint's invasion range under the influence of climate change. Globally, bushmint's potential distribution might shrink in future with more shrinkage for A2a scenario than B2a. The study outcome has immense potential for undertaking effective preventive/control measures and long-term management strategies for regions/countries, which are at higher risk of bushmint's invasion.
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Yang, Hui-Feng; Zheng, Jiang-Hua; Jia, Xiao-Guang; Li, Xiao-Jin
2017-03-01
Apocynum venetum belongs to apocynaceae and is a perennial medicinal plant, its stem is an important textile raw materials. The projection of potential geographic distribution of A. venetum has an important significance for the protection and sustainable utilization of the plant. This study was conducted to determine the potential geographic distribution of A. venetum and to project how climate change would affect its geographic distribution. The projection geographic distribution of A. venetum under current bioclimatic conditions in northern China was simulated using MaxEnt software based on species presence data at 44 locations and 19 bioclimatic parameters. The future distributions of A. venetum were also projected in 2050 and 2070 under the climate change scenarios of RCP2.6 and RCP8.5 described in 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The result showed that min air temperature of the coldest month, annual mean air temperature, precipitation of the coldest quarter and mean air temperature of the wettest quarter dominated the geographic distribution of A. venetum. Under current climate, the suitable habitats of A. venetum is 11.94% in China, the suitable habitats are mainly located in the middle of Xinjiang, in the northern part of Gansu, in the southern part of Neimeng, in the northern part of Ningxia, in the middle and northern part of Shaanxi, in the southern part of Shanxi, in the middle and northern part of Henan, in the middle and southern part of Hebei, Shandong, Tianjin, in the southern part of Liaoning and part of Beijing. From 2050 to 2070, the model outputs indicated that the suitable habitats of A. venetum would decrease under the climate change scenarios of RCP2.6 and RCP8.5. Copyright© by the Chinese Pharmaceutical Association.
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NASA Astrophysics Data System (ADS)
Schlögl, Matthias; Matulla, Christoph
2018-04-01
In the face of climate change, the assessment of land transport infrastructure exposure towards adverse climate events is of major importance for Europe's economic prosperity and social wellbeing. In this study, a climate index estimating rainfall patterns which trigger landslides in central Europe is analysed until the end of this century and compared to present-day conditions. The analysis of the potential future development of landslide risk is based on an ensemble of dynamically downscaled climate projections which are driven by the SRES A1B socio-economic scenario. Resulting regional-scale climate change projections across central Europe are concatenated with Europe's road and railway network. Results indicate overall increases of landslide occurrence. While flat terrain at low altitudes exhibits an increase of about 1 more potentially landslide-inducing rainfall period per year until the end of this century, higher elevated regions are more affected and show increases of up to 14 additional periods. This general spatial distribution emerges in the near future (2021-2050) but becomes more pronounced in the remote future (2071-2100). Since largest increases are to be found in Alsace, potential impacts of an increasing amount of landslides are discussed using the example of a case study covering the Black Forest mountain range in Baden-Württemberg by further enriching the climate information with additional geodata. The findings derived are suitable to support political decision makers and European authorities in transport, freight and logistics by offering detailed information on which parts of Europe's ground transport network are at particularly high risk concerning landslide activity.
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Zhang, Keliang; Yao, Linjun; Meng, Jiasong; Tao, Jun
2018-09-01
Paeonia (Paeoniaceae), an economically important plant genus, includes many popular ornamentals and medicinal plant species used in traditional Chinese medicine. Little is known about the properties of the habitat distribution and the important eco-environmental factors shaping the suitability. Based on high-resolution environmental data for current and future climate scenarios, we modeled the present and future suitable habitat for P. delavayi and P. rockii by Maxent, evaluated the importance of environmental factors in shaping their distribution, and identified distribution shifts under climate change scenarios. The results showed that the moderate and high suitable areas for P. delavayi and P. rockii encompassed ca. 4.46×10 5 km 2 and 1.89×10 5 km 2 , respectively. Temperature seasonality and isothermality were identified as the most critical factors shaping P. delavayi distribution, and UVB-4 and annual precipitation were identified as the most critical for shaping P. rockii distribution. Under the scenario with a low concentration of greenhouse gas emissions (RCP2.6), the range of both species increased as global warming intensified; however, under the scenario with higher concentrations of emissions (RCP8.5), the suitable habitat range of P. delavayi decreased while P. rockii increased. Overall, our prediction showed that a shift in distribution of suitable habitat to higher elevations would gradually become more significant. The information gained from this study should provide a useful reference for implementing long-term conservation and management strategies for these species. Copyright © 2018. Published by Elsevier B.V.
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Vulnerability of Breeding Waterbirds to Climate Change in the Prairie Pothole Region, U.S.A
Steen, Valerie; Skagen, Susan K.; Noon, Barry R.
2014-01-01
The Prairie Pothole Region (PPR) of the north-central U.S. and south-central Canada contains millions of small prairie wetlands that provide critical habitat to many migrating and breeding waterbirds. Due to their small size and the relatively dry climate of the region, these wetlands are considered at high risk for negative climate change effects as temperatures increase. To estimate the potential impacts of climate change on breeding waterbirds, we predicted current and future distributions of species common in the PPR using species distribution models (SDMs). We created regional-scale SDMs for the U.S. PPR using Breeding Bird Survey occurrence records for 1971–2011 and wetland, upland, and climate variables. For each species, we predicted current distribution based on climate records for 1981–2000 and projected future distributions to climate scenarios for 2040–2049. Species were projected to, on average, lose almost half their current habitat (-46%). However, individual species projections varied widely, from +8% (Upland Sandpiper) to -100% (Wilson's Snipe). Variable importance ranks indicated that land cover (wetland and upland) variables were generally more important than climate variables in predicting species distributions. However, climate variables were relatively more important during a drought period. Projected distributions of species responses to climate change contracted within current areas of distribution rather than shifting. Given the large variation in species-level impacts, we suggest that climate change mitigation efforts focus on species projected to be the most vulnerable by enacting targeted wetland management, easement acquisition, and restoration efforts. PMID:24927165
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Vulnerability of breeding waterbirds to climate change in the Prairie Pothole Region, U.S.A.
Steen, Valerie; Skagen, Susan K.; Noon, Barry R.
2014-01-01
The Prairie Pothole Region (PPR) of the north-central U.S. and south-central Canada contains millions of small prairie wetlands that provide critical habitat to many migrating and breeding waterbirds. Due to their small size and the relatively dry climate of the region, these wetlands are considered at high risk for negative climate change effects as temperatures increase. To estimate the potential impacts of climate change on breeding waterbirds, we predicted current and future distributions of species common in the PPR using species distribution models (SDMs). We created regional-scale SDMs for the U.S. PPR using Breeding Bird Survey occurrence records for 1971–2011 and wetland, upland, and climate variables. For each species, we predicted current distribution based on climate records for 1981–2000 and projected future distributions to climate scenarios for 2040–2049. Species were projected to, on average, lose almost half their current habitat (-46%). However, individual species projections varied widely, from +8% (Upland Sandpiper) to -100% (Wilson's Snipe). Variable importance ranks indicated that land cover (wetland and upland) variables were generally more important than climate variables in predicting species distributions. However, climate variables were relatively more important during a drought period. Projected distributions of species responses to climate change contracted within current areas of distribution rather than shifting. Given the large variation in species-level impacts, we suggest that climate change mitigation efforts focus on species projected to be the most vulnerable by enacting targeted wetland management, easement acquisition, and restoration efforts.
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Potential Futures for Information.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ackermann, Mark R.
Information is one of the most powerful tools available today. All advances in technology may be used, as David Sarnoff said, for the benefit or harm of society. Information can be used to shape the future by free people, or used to control people by less than benevolent governments, as has been demonstrated since the mid - 1930s, and with growing frequency over the past 50 years. What promised to once set people free and fuel an industrial revolution that might improve the standard of living over most of the world, has also been used to manipulate and enslave entiremore » populations. The future of information is tied to the future of technologies that support the collection of data, processing those data into information and knowledge, and distribution. Technologies supporting the future of information must include technologies that help protect the integrity of data and information, and help to guarantee its discoverability and appropriate availability -- often to the whole of society. This Page Intentionally Left Blank« less
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Washington Geothermal Play Fairway Analysis Data From Potential Field Studies
Anderson, Megan; Ritzinger, Brent; Glen, Jonathan; Schermerhorn, William
2017-12-20
A recent study which adapts play fairway analysis (PFA) methodology to assess geothermal potential was conducted at three locations (Mount Baker, Mount St. Helens seismic zone, and Wind River valley) along the Washington Cascade Range (Forson et al. 2017). Potential field (gravity and magnetic) methods which can detect subsurface contrasts in physical properties, provides a means for mapping and modeling subsurface geology and structure. As part of the WA-Cascade PFA project, we performed potential field studies by collecting high-resolution gravity and ground-magnetic data, and rock property measurements to (1) identify and constrain fault geometries (2) constrain subsurface lithologic distribution (3) study fault interactions (4) identify areas favorable to hydrothermal flow, and ultimately (5) guide future geothermal exploration at each location.
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Future global SLR network evolution and its impact on the terrestrial reference frame
NASA Astrophysics Data System (ADS)
Kehm, Alexander; Bloßfeld, Mathis; Pavlis, Erricos C.; Seitz, Florian
2018-06-01
Satellite laser ranging (SLR) is an important technique that contributes to the determination of terrestrial geodetic reference frames, especially to the realization of the origin and the scale of global networks. One of the major limiting factors of SLR-derived reference frame realizations is the datum accuracy which significantly suffers from the current global SLR station distribution. In this paper, the impact of a potential future development of the SLR network on the estimated datum parameters is investigated. The current status of the SLR network is compared to a simulated potential future network featuring additional stations improving the global network geometry. In addition, possible technical advancements resulting in a higher amount of observations are taken into account as well. As a result, we find that the network improvement causes a decrease in the scatter of the network translation parameters of up to 24%, and up to 20% for the scale, whereas the technological improvement causes a reduction in the scatter of up to 27% for the translations and up to 49% for the scale. The Earth orientation parameters benefit by up to 15% from both effects.
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The future of terrestrial mammals in the Mediterranean basin under climate change
Maiorano, Luigi; Falcucci, Alessandra; Zimmermann, Niklaus E.; Psomas, Achilleas; Pottier, Julien; Baisero, Daniele; Rondinini, Carlo; Guisan, Antoine; Boitani, Luigi
2011-01-01
The Mediterranean basin is considered a hotspot of biological diversity with a long history of modification of natural ecosystems by human activities, and is one of the regions that will face extensive changes in climate. For 181 terrestrial mammals (68% of all Mediterranean mammals), we used an ensemble forecasting approach to model the future (approx. 2100) potential distribution under climate change considering five climate change model outputs for two climate scenarios. Overall, a substantial number of Mediterranean mammals will be severely threatened by future climate change, particularly endemic species. Moreover, we found important changes in potential species richness owing to climate change, with some areas (e.g. montane region in central Italy) gaining species, while most of the region will be losing species (mainly Spain and North Africa). Existing protected areas (PAs) will probably be strongly influenced by climate change, with most PAs in Africa, the Middle East and Spain losing a substantial number of species, and those PAs gaining species (e.g. central Italy and southern France) will experience a substantial shift in species composition. PMID:21844047
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Hager, Heather A; Sinasac, Sarah E; Gedalof, Ze'ev; Newman, Jonathan A
2014-01-01
In many regions, large proportions of the naturalized and invasive non-native floras were originally introduced deliberately by humans. Pest risk assessments are now used in many jurisdictions to regulate the importation of species and usually include an estimation of the potential distribution in the import area. Two species of Asian grass (Miscanthus sacchariflorus and M. sinensis) that were originally introduced to North America as ornamental plants have since escaped cultivation. These species and their hybrid offspring are now receiving attention for large-scale production as biofuel crops in North America and elsewhere. We evaluated their potential global climate suitability for cultivation and potential invasion using the niche model CLIMEX and evaluated the models' sensitivity to the parameter values. We then compared the sensitivity of projections of future climatically suitable area under two climate models and two emissions scenarios. The models indicate that the species have been introduced to most of the potential global climatically suitable areas in the northern but not the southern hemisphere. The more narrowly distributed species (M. sacchariflorus) is more sensitive to changes in model parameters, which could have implications for modelling species of conservation concern. Climate projections indicate likely contractions in potential range in the south, but expansions in the north, particularly in introduced areas where biomass production trials are under way. Climate sensitivity analysis shows that projections differ more between the selected climate change models than between the selected emissions scenarios. Local-scale assessments are required to overlay suitable habitat with climate projections to estimate areas of cultivation potential and invasion risk.
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Modeling Potential Tephra Dispersal at Yucca Mountain, Nevada
NASA Astrophysics Data System (ADS)
Hooper, D.; Franklin, N.; Adams, N.; Basu, D.
2006-12-01
Quaternary basaltic volcanoes exist within 20 km [12 mi] of the potential radioactive waste repository at Yucca Mountain, Nevada, and future basaltic volcanism at the repository is considered a low-probability, potentially high-consequence event. If radioactive waste was entrained in the conduit of a future volcanic event, tephra and waste could be transported in the resulting eruption plume. During an eruption, basaltic tephra would be dispersed primarily according to the height of the eruption column, particle-size distribution, and structure of the winds aloft. Following an eruption, contaminated tephra-fall deposits would be affected by surface redistribution processes. The Center for Nuclear Waste Regulatory Analyses developed the computer code TEPHRA to calculate atmospheric dispersion and subsequent deposition of tephra and spent nuclear fuel from a potential eruption at Yucca Mountain and to help prepare the U.S. Nuclear Regulatory Commission to review a potential U.S. Department of Energy license application. The TEPHRA transport code uses the Suzuki model to simulate the thermo-fluid dynamics of atmospheric tephra dispersion. TEPHRA models the transport of airborne pyroclasts based on particle diffusion from an eruption column, horizontal diffusion of particles by atmospheric and plume turbulence, horizontal advection by atmospheric circulation, and particle settling by gravity. More recently, TEPHRA was modified to calculate potential tephra deposit distributions using stratified wind fields based on upper atmosphere data from the Nevada Test Site. Wind data are binned into 1-km [0.62-mi]-high intervals with coupled distributions of wind speed and direction produced for each interval. Using this stratified wind field and discretization with respect to height, TEPHRA calculates particle fall and lateral displacement for each interval. This implementation permits modeling of split wind fields. We use a parallel version of the code to calculate expected tephra and high-level waste accumulation at specified points on a two-dimensional spatial grid, thereby simulating a three- dimensional initial deposit. To assess subsequent tephra and high-level waste redistribution and resuspension, modeling grids were devised to measure deposition in eolian and fluvial source regions. The eolian grid covers an area of 2,600 km2 [1,000 mi2] and the fluvial grid encompasses 318 km2 [123 mi2] of the southernmost portion of the Fortymile Wash catchment basin. Because each realization is independent, distributions of tephra and high-level waste reflect anticipated variations in source-term and transport characteristics. This abstract is an independent product of the Center for Nuclear Waste Regulatory Analyses and does not necessarily reflect the view or regulatory position of the U.S. Nuclear Regulatory Commission.
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Parallel kinematic mechanisms for distributed actuation of future structures
NASA Astrophysics Data System (ADS)
Lai, G.; Plummer, A. R.; Cleaver, D. J.; Zhou, H.
2016-09-01
Future machines will require distributed actuation integrated with load-bearing structures, so that they are lighter, move faster, use less energy, and are more adaptable. Good examples are shape-changing aircraft wings which can adapt precisely to the ideal aerodynamic form for current flying conditions, and light but powerful robotic manipulators which can interact safely with human co-workers. A 'tensegrity structure' is a good candidate for this application due to its potentially excellent stiffness and strength-to-weight ratio and a multi-element structure into which actuators could be embedded. This paper presents results of an analysis of an example practical actuated tensegrity structure consisting of 3 ‘unit cells’. A numerical method is used to determine the stability of the structure with varying actuator length, showing how four actuators can be used to control movement in three degrees of freedom as well as simultaneously maintaining the structural pre-load. An experimental prototype has been built, in which 4 pneumatic artificial muscles (PAMs) are embedded in one unit cell. The PAMs are controlled antagonistically, by high speed switching of on-off valves, to achieve control of position and structure pre-load. Experimental and simulation results are presented, and future prospects for the approach are discussed.
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The Brazilian Air Force Health System: Workforce-Needs Estimation Using System Dynamics
2009-03-01
workforce in the system. 3. Non- intervention This forecast provides a potential scenario of workforce numbers, based solely on actual numbers derived from...present knowledge and actions taken under the assumption that no unexpected interventions will occur. It is a red flag that guides future decisions...represented as a distribution. Bartholomew (1974) establishes a stochastic model of manpower systems as a probabilistic description of the
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Theoretical vibrational spectra of diformates: Diformate anion
NASA Astrophysics Data System (ADS)
Dobrowolski, Jan Cz.; Jamróz, Michał H.; Kazimirski, Jan K.; Bajdor, Krzysztof; Borowiak, Marek A.; Larsson, Ragnar
1999-05-01
The IR spectrum of the most stable diformate anion was calculated at the MP2/6-311++G(3df, 3pd), RHF/6-311++G **, and B3PW91/6-311++G ** levels. The internal coordinates were defined for the diformate anion and used in potential energy distribution (PED) analysis. The PED analysis of the theoretical spectra form the basis for elucidation of the future matrix isolation IR spectra.
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Louis Iverson; Anantha Prasad; Anantha Prasad
2003-01-01
FIA data are extremely valuable for evaluating regional variation in forest distribution. We have processed and summarized FIA data to show four patterns across the Eastern United States: 1) the number and density of FIA forested plots by state, 2) current importance values and frequencies for several species within 20 x 20 km blocks, 3) tree diversity by block, and 4...
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Louis Iverson; Anantha Prasad
2002-01-01
FIA data are extremely valuable for evaluating regional variation in forest distribution. We have processed and summarized FIA data to show four patterns across the Eastern United States: 1) the number and density of FIA forested plots by state, 2) current importance values and frequencies for several species within 20 x 20 km blocks, 3) tree diversity by block, and 4...
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An Integrated XRF/XRD Instrument for Mars Exobiology and Geology Experiments
NASA Technical Reports Server (NTRS)
Koppel, L. N.; Franco, E. D.; Kerner, J. A.; Fonda, M. L.; Schwartz, D. E.; Marshall, J. R.
1993-01-01
By employing an integrated x-ray instrument on a future Mars mission, data obtained will greatly augment those returned by Viking; details characterizing the past and present environment on Mars and those relevant to the possibility of the origin and evolution of life will be acquired. A combined x-ray fluorescence/x-ray diffraction (XRF/XRD) instrument was breadboarded and demonstrated to accommodate important exobiology and geology experiment objectives outlined for MESUR and future Mars missions. Among others, primary objectives for the exploration of Mars include the intense study of local areas on Mars to establish the chemical, mineralogical, and petrological character of different components of the surface material; to determine the distribution, abundance, and sources and sinks of volatile materials, including an assessment of the biologic potential, now and during past epoches; and to establish the global chemical and physical characteristics of the Martian surface. The XRF/XRD breadboard instrument identifies and quantifies soil surface elemental, mineralogical, and petrological characteristics and acquires data necessary to address questions on volatile abundance and distribution. Additionally, the breadboard is able to characterize the biogenic element constituents of soil samples providing information on the biologic potential of the Mars environment. Preliminary breadboard experiments confirmed the fundamental instrument design approach and measurement performance.
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Goovaerts, P; Albuquerque, Teresa; Antunes, Margarida
2016-11-01
This paper describes a multivariate geostatistical methodology to delineate areas of potential interest for future sedimentary gold exploration, with an application to an abandoned sedimentary gold mining region in Portugal. The main challenge was the existence of only a dozen gold measurements confined to the grounds of the old gold mines, which precluded the application of traditional interpolation techniques, such as cokriging. The analysis could, however, capitalize on 376 stream sediment samples that were analyzed for twenty two elements. Gold (Au) was first predicted at all 376 locations using linear regression (R 2 =0.798) and four metals (Fe, As, Sn and W), which are known to be mostly associated with the local gold's paragenesis. One hundred realizations of the spatial distribution of gold content were generated using sequential indicator simulation and a soft indicator coding of regression estimates, to supplement the hard indicator coding of gold measurements. Each simulated map then underwent a local cluster analysis to identify significant aggregates of low or high values. The one hundred classified maps were processed to derive the most likely classification of each simulated node and the associated probability of occurrence. Examining the distribution of the hot-spots and cold-spots reveals a clear enrichment in Au along the Erges River downstream from the old sedimentary mineralization.
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Phosphorus Import Dependency and Recycling Potential in the Global Phosphorus Mosaic
NASA Astrophysics Data System (ADS)
Powers, S. M.
2017-12-01
Nations differ widely in terms of recent P consumption trends and fertilizer trade dependencies, reflecting dynamic and globally uneven P fertilizer production, consumption, export, and import. Recovered P from urban and agricultural wastes can provide renewable sources that supplant the need to import P fertilizer, but to date, research on P recycling potential has been highly spatially segregated. Understanding of the global distribution of P recycling potential and options, and how these intersect with P import dependencies, could be used to guide long-term, spatially-prioritized planning for P, food, and water security. We integrated recent data on national P fertilizer flows, subnational P use, and landscape features within a global grid to understand how these constraints on future options for P use are distributed worldwide. This analysis illustrates several regions where combinations of high population density, cropland extent, and manure P production provide islands of opportunity for P recycling in mixed crop-livestock and populous agricultural areas. At the same time, nations with lower import ratios (net P import:consumption) contained a disproportionately large share of manure-rich croplands and populous croplands. As a further demonstration of the kinds of integrated comparisons that are possible using global land use data sets in combination with P, worldwide similarities and distinctions for P emerged from a cluster analysis. These kinds of socioeconomic-geographic patterns may foretell distinct P futures as societies address spatially uneven options for P, food, and water security.
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NASA Astrophysics Data System (ADS)
Mátyás, Csaba; Berki, Imre; Bidlo, Andras; Czimber, Kornel.; Gálos, Borbala; Gribovszki, Zoltan; Lakatos, Ferenc; Borovics, Attila; Csóka, György; Führer, Ernő; Illés, Gábor; Rasztovits, Ervin; Somogyi, Zoltán; Bartholy, Judit
2017-04-01
The rapid progress of site potential change, caused by the shift of climate zones is a serious problem of lowland management in Southeast Europe. In forestry, the resilience potential of main, climate-dependent tree species (e.g. spruce, beech, sessile oak) and ecosystems is limited at their lower (xeric) limits of distribution. A conventional mitigation measure for adaptive forest management is the return to nature-close management. Severe drought- and biotic impacts in forests indicate however the urgency of fundamental changes in forest policy. To provide assistance in selecting climate-tolerant provenances, species and adaptive technologies for future site conditions is therefore critical. A simplified Decision Support System has been developed for Hungary, keeping conventional elements of site potential assessment. Projections are specified for discrete site types. Processing forest inventory, landcover and geodata, the System provides GIS-supported site information and projections for individual forest compartments, options for tree species better tolerating future climate scenarios as well as their expected yield and risks. Data respectively projections are available for recent and current conditions, and for future reference periods until 2100. Also non-forest site conditions in the novel grassland (steppe) climate zone appear in projections. Experiences for proper management on these sites are however scarce.
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Multi-scale predictions of coniferous forest mortality in the northern hemisphere
NASA Astrophysics Data System (ADS)
McDowell, N. G.
2015-12-01
Global temperature rise and extremes accompanying drought threaten forests and their associated climatic feedbacks. Our incomplete understanding of the fundamental physiological thresholds of vegetation mortality during drought limits our ability to accurately simulate future vegetation distributions and associated climate feedbacks. Here we integrate experimental evidence with models to show potential widespread loss of needleleaf evergreen trees (NET; ~ conifers) within the Southwest USA by 2100; with rising temperature being the primary cause of mortality. Experimentally, dominant Southwest USA NET species died when they fell below predawn water potential (Ypd) thresholds (April-August mean) beyond which photosynthesis, stomatal and hydraulic conductance, and carbohydrate availability approached zero. Empirical and mechanistic models accurately predicted NET Ypd, and 91% of predictions (10/11) exceeded mortality thresholds within the 21st century due to temperature rise. Completely independent global models predicted >50% loss of northern hemisphere NET by 2100, consistent with the findings for Southwest USA. The global models disagreed with the ecosystem process models in regards to future mortality in Southwest USA, however, highlighting the potential underestimates of future NET mortality as simulated by the global models and signifying the importance of improving regional predictions. Taken together, these results from the validated regional predictions and the global simulations predict global-scale conifer loss in coming decades under projected global warming.
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Camp, Richard J.; Loh, Rhonda; Berkowitz, S. Paul; Brinck, Kevin W.; Jacobi, James D.; Price, Jonathan; McDaniel, Sierra; Fortini, Lucas B.
2018-01-01
Climate change will likely alter the seasonal and annual patterns of rainfall and temperature in Hawai`i. This is a major concern for resource managers at Hawai`i Volcanoes National Park where intensely managed Special Ecological Areas (SEAs), focal sites for managing rare and endangered plants, may no longer provide suitable habitat under future climate. Expanding invasive species’ distributions also may pose a threat to areas where native plants currently predominate. We combine recent climate modeling efforts for the state of Hawai`i with plant species distribution models to forecast changes in biodiversity in SEAs under future climate conditions. Based on this bioclimatic envelope model, we generated projected species range maps for four snapshots in time (2000, 2040, 2070, and 2090) to assess whether the range of 39 native and invasive species of management interest are expected to contract, expand, or remain the same under a moderately warmer and more variable precipitation scenario. Approximately two-thirds of the modeled native species were projected to contract in range, while one-third were shown to increase. Most of the park’s SEAs were projected to lose a majority of the native species modeled. Nine of the 10 modeled invasive species were projected to contract within the park; this trend occurred in most SEAs, including those at low, middle, and high elevations. There was good congruence in the current (2000) distribution of species richness and SEA configuration; however, the congruence between species richness hotspots and SEAs diminished by the end of this century. Over time the projected species-rich hotspots increasingly occurred outside of current SEA boundaries. Our research brought together managers and scientists to increase understanding of potential climate change impacts, and provide needed information to address how plants may respond under future conditions relative to current managed areas.
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P300 event-related potentials in children with dyslexia.
Papagiannopoulou, Eleni A; Lagopoulos, Jim
2017-04-01
To elucidate the timing and the nature of neural disturbances in dyslexia and to further understand the topographical distribution of these, we examined entire brain regions employing the non-invasive auditory oddball P300 paradigm in children with dyslexia and neurotypical controls. Our findings revealed abnormalities for the dyslexia group in (i) P300 latency, globally, but greatest in frontal brain regions and (ii) decreased P300 amplitude confined to the central brain regions (Fig. 1). These findings reflect abnormalities associated with a diminished capacity to process mental workload as well as delayed processing of this information in children with dyslexia. Furthermore, the topographical distribution of these findings suggests a distinct spatial distribution for the observed P300 abnormalities. This information may be useful in future therapeutic or brain stimulation intervention trials.
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Leveraging ecological theory to guide natural product discovery.
Smanski, Michael J; Schlatter, Daniel C; Kinkel, Linda L
2016-03-01
Technological improvements have accelerated natural product (NP) discovery and engineering to the point that systematic genome mining for new molecules is on the horizon. NP biosynthetic potential is not equally distributed across organisms, environments, or microbial life histories, but instead is enriched in a number of prolific clades. Also, NPs are not equally abundant in nature; some are quite common and others markedly rare. Armed with this knowledge, random 'fishing expeditions' for new NPs are increasingly harder to justify. Understanding the ecological and evolutionary pressures that drive the non-uniform distribution of NP biosynthesis provides a rational framework for the targeted isolation of strains enriched in new NP potential. Additionally, ecological theory leads to testable hypotheses regarding the roles of NPs in shaping ecosystems. Here we review several recent strain prioritization practices and discuss the ecological and evolutionary underpinnings for each. Finally, we offer perspectives on leveraging microbial ecology and evolutionary biology for future NP discovery.
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Zhu, Hongyu; Kumar, Sunil; Neven, Lisa G
2017-07-01
Codling moth (Cydia pomonella L.) is an internal feeding pest of apples and can cause substantial economic losses to fruit growers due to larval feeding which in turn degrades fruit quality and can result in complete crop loss if left uncontrolled. Although this pest originally developed in central Asia, it was not known to occur in China until 1953. For the first three decades the spread of codling moth within China was slow. Within the last three decades, addition of new commercial apple orchards and improved transportation, this pest has spread to over 131 counties in seven provinces in China. We developed regional (China) and global ecological niche models using MaxEnt to identify areas at highest potential risk of codling moth establishment and spread. Our objectives were to 1) predict the potential distribution of codling moth in China, 2) identify the important environmental factors associated with codling moth distribution in China, and 3) identify the different stages of invasion of codling moth in China. Human footprint, annual temperature range, precipitation of wettest quarter, and degree days ≥10 °C were the most important predictors associated with codling moth distribution. Our analysis identified areas where codling moth has the potential to establish, and mapped the different stages of invasion (i.e., potential for population stabilization, colonization, adaptation, and sink) of codling moth in China. Our results can be used in effective monitoring and management to stem the spread of codling moth in China. Published by Oxford University Press on behalf of the Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.
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How a future energy world could look?
NASA Astrophysics Data System (ADS)
Ewert, M.
2012-10-01
The future energy system will change significantly within the next years as a result of the following Mega Trends: de-carbonization, urbanization, fast technology development, individualization, glocalization (globalization and localization) and changing demographics. Increasing fluctuating renewable production will change the role of non-renewable generation. Distributed energy from renewables and micro generation will change the direction of the energy flow in the electricity grids. Production will not follow demand but demand has to follow production. This future system is enabled by the fast technical development of information and communication technologies which will be present in the entire system. In this paper the results of a comprehensive analysis with different scenarios is summarized. Tools were used like the analysis of policy trends in the European countries, modelling of the European power grid, modelling of the European power markets and the analysis of technology developments with cost reduction potentials. With these tools the interaction of the main actors in the energy markets like conventional generation and renewable generation, grid transport, electricity storage including new storage options from E-Mobility, Power to Gas, Compressed Air Energy storage and demand side management were considered. The potential application of technologies and investments in new energy technologies were analyzed within existing frameworks and markets as well as new business models in new markets with different frameworks. In the paper the over all trend of this analysis is presented by describing a potential future energy world. This world represents only one of numerous options with comparable characteristics.
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Deep-coal potential in the Appalachian Coal Basin, USA: The Kentucky model
Haney, D.C.; Chesnut, D.R.
1997-01-01
The Eastern Kentucky Coal Field is located in the Appalachian Basin of the United States and occupies an area of approximately 15,000 square kilometers. The coal beds range from a few centimeters to several meters in thickness and consist of high-grade bituminous coal. Currently the amount of coal mined by surface methods exceeds underground extraction; however, there is a steady and gradual shift toward underground mining. In the future, as near-surface resources are depleted, this trend toward increased underground mining will continue. Knowledge about deeper coals is essential for future economic development of resources. Preliminary investigations indicate that coal-bearing strata with deep-mining potential exist in several parts of eastern Kentucky, especially along the Eastern Kentucky Syncline. Eastern Kentucky coals are Westphalian A through D; however, current production is from major beds of Westphalian A and B. Because coals that occur above drainage are more easily accessible and are generally of better quality, most of the current mining takes place in formations that are at or near the surface. In the future, however, due to environmental regulations and increased demands, it will be necessary to attempt to utilize deeper coals about which little is known. Future development of deep resources will require data from boreholes and high-resolution geophysical-logging techniques. There is also potential for coal-bed methane from the deeper coals which could be an important resource in the Appalachian Coal Basin where a natural gas distribution system already exists.
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Trapped between two tails: trading off scientific uncertainties via climate targets
NASA Astrophysics Data System (ADS)
Lemoine, Derek; McJeon, Haewon C.
2013-09-01
Climate change policies must trade off uncertainties about future warming, about the social and ecological impacts of warming, and about the cost of reducing greenhouse gas emissions. We show that laxer carbon targets produce broader distributions for climate damages, skewed towards severe outcomes. However, if potential low-carbon technologies fill overlapping niches, then more stringent carbon targets produce broader distributions for the cost of reducing emissions, skewed towards high-cost outcomes. We use the technology-rich GCAM integrated assessment model to assess the robustness of 450 and 500 ppm carbon targets to each uncertain factor. The 500 ppm target provides net benefits across a broad range of futures. The 450 ppm target provides net benefits only when impacts are greater than conventionally assumed, when multiple technological breakthroughs lower the cost of abatement, or when evaluated with a low discount rate. Policy evaluations are more sensitive to uncertainty about abatement technology and impacts than to uncertainty about warming.
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Assessment of habitat of wildlife communities on the Snake River, Jackson, Wyoming
Schroeder, Richard L.; Allen, Arthur W.
1992-01-01
The composition of the wildlife community in western riparian habitats is influenced by the horizontal and vertical distribution of vegetation, the physical complexity of the channel, and barriers to movement along the corridor. Based on information from the literature and a workshop, a model was developed to evaluate the wildlife community along the Snake River near Jackson, Wyoming. The model compares conditions of the current or future years with conditions in 1956, before constructions of levees along the river. Conditions in 1956 are assumed to approximate the desirable distribution of plant cover types and the associated wildlife community and are used as a standard of comparison in the model. The model may be applied with remotely sensed data and is compatible with a geographic information systems analysis. In addition to comparing existing or future conditions with conditions in 1956, the model evaluated floodplain and channel complexity and assesses anthropogenic disturbance and its potential effect on the quality of wildlife habitat and movements of wildlife in the riparian corridor.
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Methods, caveats and the future of large-scale microelectrode recordings in the non-human primate
Dotson, Nicholas M.; Goodell, Baldwin; Salazar, Rodrigo F.; Hoffman, Steven J.; Gray, Charles M.
2015-01-01
Cognitive processes play out on massive brain-wide networks, which produce widely distributed patterns of activity. Capturing these activity patterns requires tools that are able to simultaneously measure activity from many distributed sites with high spatiotemporal resolution. Unfortunately, current techniques with adequate coverage do not provide the requisite spatiotemporal resolution. Large-scale microelectrode recording devices, with dozens to hundreds of microelectrodes capable of simultaneously recording from nearly as many cortical and subcortical areas, provide a potential way to minimize these tradeoffs. However, placing hundreds of microelectrodes into a behaving animal is a highly risky and technically challenging endeavor that has only been pursued by a few groups. Recording activity from multiple electrodes simultaneously also introduces several statistical and conceptual dilemmas, such as the multiple comparisons problem and the uncontrolled stimulus response problem. In this perspective article, we discuss some of the techniques that we, and others, have developed for collecting and analyzing large-scale data sets, and address the future of this emerging field. PMID:26578906
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Trapped Between Two Tails: Trading Off Scientific Uncertainties via Climate Targets
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lemoine, Derek M.; McJeon, Haewon C.
2013-08-20
Climate change policies must trade off uncertainties about future warming, about the social and ecological impacts of warming, and about the cost of reducing greenhouse gas emissions. We show that laxer carbon targets produce broader distributions for climate damages, skewed towards severe outcomes. However, if potential low-carbon technologies fill overlapping niches, then more stringent carbon targets produce broader distributions for the cost of reducing emissions, skewed towards high-cost outcomes. We use the technology- rich GCAM integrated assessment model to assess the robustness of 450 ppm and 500 ppm carbon targets to each uncertain factor. The 500 ppm target provides netmore » benefits across a broad range of futures. The 450 ppm target provides net benefits only when impacts are greater than conventionally assumed, when multiple technological breakthroughs lower the cost of abatement, or when evaluated with a low discount rate. Policy evaluations are more sensitive to uncertainty about abatement technology and impacts than to uncertainty about warming.« less
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NASA Astrophysics Data System (ADS)
Kline, Jeffrey D.; Moses, Alissa; Burcsu, Theresa
2010-05-01
Forest policymakers, public lands managers, and scientists in the Pacific Northwest (USA) seek ways to evaluate the landscape-level effects of policies and management through the multidisciplinary development and application of spatially explicit methods and models. The Interagency Mapping and Analysis Project (IMAP) is an ongoing effort to generate landscape-wide vegetation data and models to evaluate the integrated effects of disturbances and management activities on natural resource conditions in Oregon and Washington (USA). In this initial analysis, we characterized the spatial distribution of forest and range land development in a four-county pilot study region in central Oregon. The empirical model describes the spatial distribution of buildings and new building construction as a function of population growth, existing development, topography, land-use zoning, and other factors. We used the model to create geographic information system maps of likely future development based on human population projections to inform complementary landscape analyses underway involving vegetation, habitat, and wildfire interactions. In an example application, we use the model and resulting maps to show the potential impacts of future forest and range land development on mule deer ( Odocoileus hemionus) winter range. Results indicate significant development encroachment and habitat loss already in 2000 with development located along key migration routes and increasing through the projection period to 2040. The example application illustrates a simple way for policymakers and public lands managers to combine existing data and preliminary model outputs to begin to consider the potential effects of development on future landscape conditions.
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Changes in extreme events and the potential impacts on human health.
Bell, Jesse E; Brown, Claudia Langford; Conlon, Kathryn; Herring, Stephanie; Kunkel, Kenneth E; Lawrimore, Jay; Luber, George; Schreck, Carl; Smith, Adam; Uejio, Christopher
2018-04-01
Extreme weather and climate-related events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, dust storms, flooding rains, coastal flooding, storm surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden. More information is needed about the impacts of climate change on public health and economies to effectively plan for and adapt to climate change. This paper describes some of the ways extreme events are changing and provides examples of the potential impacts on human health and infrastructure. It also identifies key research gaps to be addressed to improve the resilience of public health to extreme events in the future. Extreme weather and climate events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, flooding rains, coastal flooding, surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden.
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Predicting presence and absence of trout (Salmo trutta) in Iran
Mostafavi, Hossein; Pletterbauer, Florian; Coad, Brian W.; Mahini, Abdolrassoul Salman; Schinegger, Rafaela; Unfer, Günther; Trautwein, Clemens; Schmutz, Stefan
2014-01-01
Species distribution modelling, as a central issue in freshwater ecology, is an important tool for conservation and management of aquatic ecosystems. The brown trout (Salmo trutta) is a sensitive species which reacts to habitat changes induced by human impacts. Therefore, the identification of suitable habitats is essential. This study explores the potential distribution of brown trout by a species distribution modelling approach for Iran. Furthermore, modelling results are compared to the distribution described in the literature. Areas outside the currently known distribution which may offer potential habitats for brown trout are identified. The species distribution modelling was based on five different modelling techniques: Generalised Linear Model, Generalised Additive Model, Generalised Boosting Model, Classification Tree Analysis and Random Forests, which are finally summarised in an ensemble forecasting approach. We considered four environmental descriptors at the local scale (slope, bankfull width, wetted width, and elevation) and three climatic parameters (mean air temperature, range of air temperature and annual precipitation) which were extracted on three different spatial extents (1/5/10 km). The performance of all models was excellent (≥0.8) according to the TSS (True Skill Statistic) criterion. Slope, mean and range of air temperature were the most important variables in predicting brown trout occurrence. Presented results deepen the knowledge about distribution patterns of brown trout in Iran. Moreover, this study gives a basic background for the future development of assessment methods for riverine ecosystems in Iran. PMID:24707064
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Distributed Generation Market Demand Model (dGen): Documentation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sigrin, Benjamin; Gleason, Michael; Preus, Robert
The Distributed Generation Market Demand model (dGen) is a geospatially rich, bottom-up, market-penetration model that simulates the potential adoption of distributed energy resources (DERs) for residential, commercial, and industrial entities in the continental United States through 2050. The National Renewable Energy Laboratory (NREL) developed dGen to analyze the key factors that will affect future market demand for distributed solar, wind, storage, and other DER technologies in the United States. The new model builds off, extends, and replaces NREL's SolarDS model (Denholm et al. 2009a), which simulates the market penetration of distributed PV only. Unlike the SolarDS model, dGen can modelmore » various DER technologies under one platform--it currently can simulate the adoption of distributed solar (the dSolar module) and distributed wind (the dWind module) and link with the ReEDS capacity expansion model (Appendix C). The underlying algorithms and datasets in dGen, which improve the representation of customer decision making as well as the spatial resolution of analyses (Figure ES-1), also are improvements over SolarDS.« less
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Hufford, Matthew B.; Martínez-Meyer, Enrique; Gaut, Brandon S.; Eguiarte, Luis E.; Tenaillon, Maud I.
2012-01-01
Background The species Zea mays includes both domesticated maize (ssp. mays) and its closest wild relatives known as the teosintes. While genetic and archaeological studies have provided a well-established history of Z. mays evolution, there is currently minimal description of its current and past distribution. Here, we implemented species distribution modeling using paleoclimatic models of the last interglacial (LI; ∼135,000 BP) and the last glacial maximum (LGM; ∼21,000 BP) to hindcast the distribution of Zea mays subspecies over time and to revisit current knowledge of its phylogeography and evolutionary history. Methodology/Principal Findings Using a large occurrence data set and the distribution modeling MaxEnt algorithm, we obtained robust present and past species distributions of the two widely distributed teosinte subspecies (ssps. parviglumis and mexicana) revealing almost perfect complementarity, stable through time, of their occupied distributions. We also investigated the present distributions of primitive maize landraces, which overlapped but were broader than those of the teosintes. Our data reinforced the idea that little historical gene flow has occurred between teosinte subspecies, but maize has served as a genetic bridge between them. We observed an expansion of teosinte habitat from the LI, consistent with population genetic data. Finally, we identified locations potentially serving as refugia for the teosintes throughout epochs of climate change and sites that should be targeted in future collections. Conclusion/Significance The restricted and highly contrasting ecological niches of the wild teosintes differ substantially from domesticated maize. Variables determining the distributions of these taxa can inform future considerations of local adaptation and the impacts of climate change. Our assessment of the changing distributions of Zea mays taxa over time offers a unique glimpse into the history of maize, highlighting a strategy for the study of domestication that may prove useful for other species. PMID:23155371
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Modeling and forecasting the distribution of Vibrio vulnificus in Chesapeake Bay
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jacobs, John M.; Rhodes, M.; Brown, C. W.
The aim is to construct statistical models to predict the presence, abundance and potential virulence of Vibrio vulnificus in surface waters. A variety of statistical techniques were used in concert to identify water quality parameters associated with V. vulnificus presence, abundance and virulence markers in the interest of developing strong predictive models for use in regional oceanographic modeling systems. A suite of models are provided to represent the best model fit and alternatives using environmental variables that allow them to be put to immediate use in current ecological forecasting efforts. Conclusions: Environmental parameters such as temperature, salinity and turbidity aremore » capable of accurately predicting abundance and distribution of V. vulnificus in Chesapeake Bay. Forcing these empirical models with output from ocean modeling systems allows for spatially explicit forecasts for up to 48 h in the future. This study uses one of the largest data sets compiled to model Vibrio in an estuary, enhances our understanding of environmental correlates with abundance, distribution and presence of potentially virulent strains and offers a method to forecast these pathogens that may be replicated in other regions.« less
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West, Amanda M; Kumar, Sunil; Wakie, Tewodros; Brown, Cynthia S; Stohlgren, Thomas J; Laituri, Melinda; Bromberg, Jim
2015-01-01
National Parks are hallmarks of ecosystem preservation in the United States. The introduction of alien invasive plant species threatens protection of these areas. Bromus tectorum L. (commonly called downy brome or cheatgrass), which is found in Rocky Mountain National Park (hereafter, the Park), Colorado, USA, has been implicated in early spring competition with native grasses, decreased soil nitrogen, altered nutrient and hydrologic regimes, and increased fire intensity. We estimated the potential distribution of B. tectorum in the Park based on occurrence records (n = 211), current and future climate, and distance to roads and trails. An ensemble of six future climate scenarios indicated the habitable area of B. tectorum may increase from approximately 5.5% currently to 20.4% of the Park by the year 2050. Using ordination methods we evaluated the climatic space occupied by B. tectorum in the Park and how this space may shift given future climate change. Modeling climate change at a small extent (1,076 km2) and at a fine spatial resolution (90 m) is a novel approach in species distribution modeling, and may provide inference for microclimates not captured in coarse-scale models. Maps from our models serve as high-resolution hypotheses that can be improved over time by land managers to set priorities for surveys and removal of invasive species such as B. tectorum.
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West, Amanda M.; Kumar, Sunil; Wakie, Tewodros; Brown, Cynthia S.; Stohlgren, Thomas J.; Laituri, Melinda; Bromberg, Jim
2015-01-01
National Parks are hallmarks of ecosystem preservation in the United States. The introduction of alien invasive plant species threatens protection of these areas. Bromus tectorum L. (commonly called downy brome or cheatgrass), which is found in Rocky Mountain National Park (hereafter, the Park), Colorado, USA, has been implicated in early spring competition with native grasses, decreased soil nitrogen, altered nutrient and hydrologic regimes, and increased fire intensity. We estimated the potential distribution of B. tectorum in the Park based on occurrence records (n = 211), current and future climate, and distance to roads and trails. An ensemble of six future climate scenarios indicated the habitable area of B. tectorum may increase from approximately 5.5% currently to 20.4% of the Park by the year 2050. Using ordination methods we evaluated the climatic space occupied by B. tectorum in the Park and how this space may shift given future climate change. Modeling climate change at a small extent (1,076 km2) and at a fine spatial resolution (90 m) is a novel approach in species distribution modeling, and may provide inference for microclimates not captured in coarse-scale models. Maps from our models serve as high-resolution hypotheses that can be improved over time by land managers to set priorities for surveys and removal of invasive species such as B. tectorum. PMID:25695255
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Sørensen, Christina; Munday, Philip L; Nilsson, Göran E
2014-03-01
The temperature dependence of aerobic scope has been suggested to be a major determinant of how marine animals will cope with future rises in environmental temperature. Here, we present data suggesting that in some animals, the temperature dependence of anaerobic scope (i.e., the capacity for surviving severe hypoxia) may determine present-day latitudinal distributions and potential for persistence in a warmer future. As a model for investigating the role of anaerobic scope, we studied two sibling species of coral-dwelling gobies, Gobiodon histrio, and G. erythrospilus, with different latitudinal distributions, but which overlap in equal abundance at Lizard Island (14°40'S) on the Great Barrier Reef. These species did not differ in the temperature dependence of resting oxygen consumption or critical oxygen concentration (the lowest oxygen level where resting oxygen consumption can be maintained). In contrast, the more equatorial species (G. histrio) had a better capacity to endure anaerobic conditions at oxygen levels below the critical oxygen concentration at the high temperatures (32-33 °C) more likely to occur near the equator, or in a warmer future. These results suggest that anaerobic scope, in addition to aerobic scope, could be important in determining the impacts of global warming on some marine animals. © 2013 John Wiley & Sons Ltd.
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Sohl, Terry L.
2014-01-01
Species distribution models often use climate data to assess contemporary and/or future ranges for animal or plant species. Land use and land cover (LULC) data are important predictor variables for determining species range, yet are rarely used when modeling future distributions. In this study, maximum entropy modeling was used to construct species distribution maps for 50 North American bird species to determine relative contributions of climate and LULC for contemporary (2001) and future (2075) time periods. Species presence data were used as a dependent variable, while climate, LULC, and topographic data were used as predictor variables. Results varied by species, but in general, measures of model fit for 2001 indicated significantly poorer fit when either climate or LULC data were excluded from model simulations. Climate covariates provided a higher contribution to 2001 model results than did LULC variables, although both categories of variables strongly contributed. The area deemed to be "suitable" for 2001 species presence was strongly affected by the choice of model covariates, with significantly larger ranges predicted when LULC was excluded as a covariate. Changes in species ranges for 2075 indicate much larger overall range changes due to projected climate change than due to projected LULC change. However, the choice of study area impacted results for both current and projected model applications, with truncation of actual species ranges resulting in lower model fit scores and increased difficulty in interpreting covariate impacts on species range. Results indicate species-specific response to climate and LULC variables; however, both climate and LULC variables clearly are important for modeling both contemporary and potential future species ranges.
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Sohl, Terry L.
2014-01-01
Species distribution models often use climate data to assess contemporary and/or future ranges for animal or plant species. Land use and land cover (LULC) data are important predictor variables for determining species range, yet are rarely used when modeling future distributions. In this study, maximum entropy modeling was used to construct species distribution maps for 50 North American bird species to determine relative contributions of climate and LULC for contemporary (2001) and future (2075) time periods. Species presence data were used as a dependent variable, while climate, LULC, and topographic data were used as predictor variables. Results varied by species, but in general, measures of model fit for 2001 indicated significantly poorer fit when either climate or LULC data were excluded from model simulations. Climate covariates provided a higher contribution to 2001 model results than did LULC variables, although both categories of variables strongly contributed. The area deemed to be “suitable” for 2001 species presence was strongly affected by the choice of model covariates, with significantly larger ranges predicted when LULC was excluded as a covariate. Changes in species ranges for 2075 indicate much larger overall range changes due to projected climate change than due to projected LULC change. However, the choice of study area impacted results for both current and projected model applications, with truncation of actual species ranges resulting in lower model fit scores and increased difficulty in interpreting covariate impacts on species range. Results indicate species-specific response to climate and LULC variables; however, both climate and LULC variables clearly are important for modeling both contemporary and potential future species ranges. PMID:25372571
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van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L
2008-12-01
This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.
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Sato, Kirk N; Powell, Jackson; Rudie, Dave; Levin, Lisa A
2018-05-01
Marine fishery stakeholders are beginning to consider and implement adaptation strategies in the face of growing consumer demand and potential deleterious climate change impacts such as ocean warming, ocean acidification, and deoxygenation. This study investigates the potential for development of a novel climate change - tolerant sea urchin fishery in southern California based on Strongylocentrotus fragilis (pink sea urchin), a deep-sea species whose peak density was found to coincide with a current trap-based spot prawn fishery ( Pandalus platyceros ) in the 200-300-m depth range. Here we outline potential criteria for a climate change - tolerant fishery by examining the distribution, life-history attributes, and marketable qualities of S. fragilis in southern California. We provide evidence of seasonality of gonad production and demonstrate that peak gonad production occurs in the winter season. S. fragilis likely spawns in the spring season as evidenced by consistent minimum gonad indices in the spring/summer seasons across 4 years of sampling (2012-2016). The resiliency of S. fragilis to predicted future increases in acidity and decreases in oxygen was supported by high species abundance, albeit reduced relative growth rate estimates at water depths (485-510 m) subject to low oxygen (11.7-16.9 µmol kg -1 ) and pH Total (<7.44), which may provide assurances to stakeholders and managers regarding the suitability of this species for commercial exploitation. Some food quality properties of the S. fragilis roe (e.g. colour, texture) were comparable with those of the commercially exploited shallow-water red sea urchin ( Mesocentrotus franciscanus ), while other qualities (e.g. 80% reduced gonad size by weight) limit the potential future marketability of S. fragilis . This case study highlights the potential future challenges and drawbacks of climate-tolerant fishery development in an attempt to inform future urchin fishery stakeholders.
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Judge, Colleen P; Wolgemuth, Tierney E; Hamm, Megan E; Borrero, Sonya
2017-11-01
Following the 2016US presidential election, social media posts and news stories amplified concerns about the potential for reduced access to contraception under the incoming administration and urged women to seek long-acting reversible contraception. We aimed to describe women's concerns about future access to contraception, in their own words. A social-media-based, anonymous online survey assessing thoughts and concerns about future access to contraception was distributed to reproductive-aged US women for 1 week in mid-January 2017. Participants who were concerned about future access to contraception could share their thoughts and feelings in an open-ended comments box. We qualitatively analyzed 449 written responses for content and themes, with the goal of characterizing key concerns. Women who provided written comments had a mean age of 28years; 85% were white, 88% had at least a college degree, and 93% identified as Democratic or Democratic-leaning. Women were highly concerned about future affordability of contraceptive methods due to potential loss of insurance, reduced insurance coverage for contraceptive methods and reduced access to low-cost care at Planned Parenthood. Many also worried about increased restrictions on abortion. Participants' concerns regarding access to contraception and abortion centered around themes of reproductive and bodily autonomy, which women described as fundamental rights. Women in this study expressed considerable fear and uncertainty regarding their future access to contraception and abortion following the 2016US presidential election. The potential for restricted access to affordable contraception and abortion was viewed as an unacceptable limitation on bodily autonomy. As the future of US health care policy is debated, many women are concerned about the impact of policy changes on their ability to access affordable contraception and abortion, which many view as essential to the preservation of bodily and reproductive autonomy. Copyright © 2017 Elsevier Inc. All rights reserved.
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Rasmussen, Karen; Thyrring, Jakob; Muscarella, Robert; Borchsenius, Finn
2017-01-01
Invasive allergenic plant species may have severe health-related impacts. In this study we aim to predict the effects of climate change on the distribution of three allergenic ragweed species ( Ambrosia spp.) in Europe and discuss the potential associated health impact. We built species distribution models based on presence-only data for three ragweed species, using MAXENT software. Future climatic habitat suitability was modeled under two IPCC climate change scenarios (RCP 6.0 and RCP 8.5). We quantify the extent of the increase in 'high allergy risk' (HAR) areas, i.e., parts of Europe with climatic conditions corresponding to the highest quartile (25%) of present day habitat suitability for each of the three species. We estimate that by year 2100, the distribution range of all three ragweed species increases towards Northern and Eastern Europe under all climate scenarios. HAR areas will expand in Europe by 27-100%, depending on species and climate scenario. Novel HAR areas will occur mostly in Denmark, France, Germany, Russia and the Baltic countries, and overlap with densely populated cities such as Paris and St. Petersburg. We conclude that areas in Europe affected by severe ragweed associated allergy problems are likely to increase substantially by year 2100, affecting millions of people. To avoid this, management strategies must be developed that restrict ragweed dispersal and establishment of new populations. Precautionary efforts should limit the spread of ragweed seeds and reduce existing populations. Only by applying cross-countries management plans can managers mitigate future health risks and economical consequences of a ragweed expansion in Europe.
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Current and Future Patterns of Global Marine Mammal Biodiversity
Kaschner, Kristin; Tittensor, Derek P.; Ready, Jonathan; Gerrodette, Tim; Worm, Boris
2011-01-01
Quantifying the spatial distribution of taxa is an important prerequisite for the preservation of biodiversity, and can provide a baseline against which to measure the impacts of climate change. Here we analyse patterns of marine mammal species richness based on predictions of global distributional ranges for 115 species, including all extant pinnipeds and cetaceans. We used an environmental suitability model specifically designed to address the paucity of distributional data for many marine mammal species. We generated richness patterns by overlaying predicted distributions for all species; these were then validated against sightings data from dedicated long-term surveys in the Eastern Tropical Pacific, the Northeast Atlantic and the Southern Ocean. Model outputs correlated well with empirically observed patterns of biodiversity in all three survey regions. Marine mammal richness was predicted to be highest in temperate waters of both hemispheres with distinct hotspots around New Zealand, Japan, Baja California, the Galapagos Islands, the Southeast Pacific, and the Southern Ocean. We then applied our model to explore potential changes in biodiversity under future perturbations of environmental conditions. Forward projections of biodiversity using an intermediate Intergovernmental Panel for Climate Change (IPCC) temperature scenario predicted that projected ocean warming and changes in sea ice cover until 2050 may have moderate effects on the spatial patterns of marine mammal richness. Increases in cetacean richness were predicted above 40° latitude in both hemispheres, while decreases in both pinniped and cetacean richness were expected at lower latitudes. Our results show how species distribution models can be applied to explore broad patterns of marine biodiversity worldwide for taxa for which limited distributional data are available. PMID:21625431
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Meynard, Christine N; Gay, Pierre-Emmanuel; Lecoq, Michel; Foucart, Antoine; Piou, Cyril; Chapuis, Marie-Pierre
2017-11-01
The desert locust is an agricultural pest that is able to switch from a harmless solitarious stage, during recession periods, to swarms of gregarious individuals that disperse long distances and affect areas from western Africa to India during outbreak periods. Large outbreaks have been recorded through centuries, and the Food and Agriculture Organization keeps a long-term, large-scale monitoring survey database in the area. However, there is also a much less known subspecies that occupies a limited area in Southern Africa. We used large-scale climatic and occurrence data of the solitarious phase of each subspecies during recession periods to understand whether both subspecies climatic niches differ from each other, what is the current potential geographical distribution of each subspecies, and how climate change is likely to shift their potential distribution with respect to current conditions. We evaluated whether subspecies are significantly specialized along available climate gradients by using null models of background climatic differences within and between southern and northern ranges and applying niche similarity and niche equivalency tests. The results point to climatic niche conservatism between the two clades. We complemented this analysis with species distribution modeling to characterize current solitarious distributions and forecast potential recession range shifts under two extreme climate change scenarios at the 2050 and 2090 time horizon. Projections suggest that, at a global scale, the northern clade could contract its solitarious recession range, while the southern clade is likely to expand its recession range. However, local expansions were also predicted in the northern clade, in particular in southern and northern margins of the current geographical distribution. In conclusion, monitoring and management practices should remain in place in northern Africa, while in Southern Africa the potential for the subspecies to pose a threat in the future should be investigated more closely. © 2017 John Wiley & Sons Ltd.
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NASA Technical Reports Server (NTRS)
Shu, J. Y.
1983-01-01
Two different singularity methods have been utilized to calculate the potential flow past a three dimensional non-lifting body. Two separate FORTRAN computer programs have been developed to implement these theoretical models, which will in the future allow inclusion of the fuselage effect in a pair of existing subcritical wing design computer programs. The first method uses higher order axial singularity distributions to model axisymmetric bodies of revolution in an either axial or inclined uniform potential flow. Use of inset of the singularity line away from the body for blunt noses, and cosine-type element distributions have been applied to obtain the optimal results. Excellent agreement to five significant figures with the exact solution pressure coefficient value has been found for a series of ellipsoids at different angles of attack. Solutions obtained for other axisymmetric bodies compare well with available experimental data. The second method utilizes distributions of singularities on the body surface, in the form of a discrete vortex lattice. This program is capable of modeling arbitrary three dimensional non-lifting bodies. Much effort has been devoted to finding the optimal method of calculating the tangential velocity on the body surface, extending techniques previously developed by other workers.
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Resource Exploration Approaches on Mars Using Multidisciplinary Earth-based Techniques
NASA Astrophysics Data System (ADS)
Wyrick, D. Y.; Ferrill, D. A.; Morris, A. P.; Smart, K. J.
2005-12-01
Water is the most important Martian exploration target - key to finding evidence of past life and providing a crucial resource for future exploration. Water is thought to be present in vapor, liquid, and ice phases on Mars. Except for ice in polar regions, little direct evidence of current surface accumulation of water has been found. Existing research has addressed potential source areas, including meteoric water, glacial ice, and volcanic centers and areas of discharge such as large paleo-outflow channels. Missing from these analyses is characterization of migration pathways of water in the subsurface from sources to discharge areas, and the present distribution of water. It has been estimated that ~90% of the global inventory of water on Mars resides in the subsurface. Targeting potential subsurface accumulations has relied primarily on theoretical modeling and geomorphic analysis. While global scale thermal modeling and analysis of the stability of ground ice provide important constraints on potential locations of large deposits of ice or liquid water, these studies have not accounted for variations in stratigraphy and structure that may strongly influence local distribution. Depth to water or ice on Mars is thought to be controlled primarily by latitude and elevation. However, the distribution of outflow channels clearly indicates that structural, stratigraphic, and geomorphic features all play important roles in determining past and present distribution of water and ice on Mars as they do on Earth. Resource exploration and extraction is a multi-billion dollar industry on Earth that has developed into a highly sophisticated enterprise with constantly improving exploration technologies. Common to all successful exploration programs, whether for hydrocarbons or water, is detailed analysis and integration of all available geologic, geophysical and remotely sensed data. The primary issues for identification and characterization of water or hydrocarbon resource accumulations can be summarized by three factors: trap, reservoir and charge. This presentation focuses on a detailed characterization of the fundamental elements believed to control trap, reservoir, and charge with respect to the identification of locations for extractable resources on Mars, primarily water and ice, but also gas hydrates. This new approach to resource exploration will also provide guidance for future research and exploration activities, including movement of methane from the subsurface to the surface and potential habitat sites for past or current life on Mars.
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Liu, Yupeng; Yu, Deyong; Xun, Bin; Sun, Yun; Hao, Ruifang
2014-01-01
Climate changes may have immediate implications for forest productivity and may produce dramatic shifts in tree species distributions in the future. Quantifying these implications is significant for both scientists and managers. Cunninghamia lanceolata is an important coniferous timber species due to its fast growth and wide distribution in China. This paper proposes a methodology aiming at enhancing the distribution and productivity of C. lanceolata against a background of climate change. First, we simulated the potential distributions and establishment probabilities of C. lanceolata based on a species distribution model. Second, a process-based model, the PnET-II model, was calibrated and its parameterization of water balance improved. Finally, the improved PnET-II model was used to simulate the net primary productivity (NPP) of C. lanceolata. The simulated NPP and potential distribution were combined to produce an integrated indicator, the estimated total NPP, which serves to comprehensively characterize the productivity of the forest under climate change. The results of the analysis showed that (1) the distribution of C. lanceolata will increase in central China, but the mean probability of establishment will decrease in the 2050s; (2) the PnET-II model was improved, calibrated, and successfully validated for the simulation of the NPP of C. lanceolata in China; and (3) all scenarios predicted a reduction in total NPP in the 2050s, with a markedly lower reduction under the a2 scenario than under the b2 scenario. The changes in NPP suggested that forest productivity will show a large decrease in southern China and a mild increase in central China. All of these findings could improve our understanding of the impact of climate change on forest ecosystem structure and function and could provide a basis for policy-makers to apply adaptive measures and overcome the unfavorable influences of climate change.
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Increasing potential for intense tropical and subtropical thunderstorms under global warming.
Singh, Martin S; Kuang, Zhiming; Maloney, Eric D; Hannah, Walter M; Wolding, Brandon O
2017-10-31
Intense thunderstorms produce rapid cloud updrafts and may be associated with a range of destructive weather events. An important ingredient in measures of the potential for intense thunderstorms is the convective available potential energy (CAPE). Climate models project increases in summertime mean CAPE in the tropics and subtropics in response to global warming, but the physical mechanisms responsible for such increases and the implications for future thunderstorm activity remain uncertain. Here, we show that high percentiles of the CAPE distribution (CAPE extremes) also increase robustly with warming across the tropics and subtropics in an ensemble of state-of-the-art climate models, implying strong increases in the frequency of occurrence of environments conducive to intense thunderstorms in future climate projections. The increase in CAPE extremes is consistent with a recently proposed theoretical model in which CAPE depends on the influence of convective entrainment on the tropospheric lapse rate, and we demonstrate the importance of this influence for simulated CAPE extremes using a climate model in which the convective entrainment rate is varied. We further show that the theoretical model is able to account for the climatological relationship between CAPE and a measure of lower-tropospheric humidity in simulations and in observations. Our results provide a physical basis on which to understand projected future increases in intense thunderstorm potential, and they suggest that an important mechanism that contributes to such increases may be present in Earth's atmosphere. Published under the PNAS license.
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Increasing potential for intense tropical and subtropical thunderstorms under global warming
Kuang, Zhiming; Maloney, Eric D.; Hannah, Walter M.; Wolding, Brandon O.
2017-01-01
Intense thunderstorms produce rapid cloud updrafts and may be associated with a range of destructive weather events. An important ingredient in measures of the potential for intense thunderstorms is the convective available potential energy (CAPE). Climate models project increases in summertime mean CAPE in the tropics and subtropics in response to global warming, but the physical mechanisms responsible for such increases and the implications for future thunderstorm activity remain uncertain. Here, we show that high percentiles of the CAPE distribution (CAPE extremes) also increase robustly with warming across the tropics and subtropics in an ensemble of state-of-the-art climate models, implying strong increases in the frequency of occurrence of environments conducive to intense thunderstorms in future climate projections. The increase in CAPE extremes is consistent with a recently proposed theoretical model in which CAPE depends on the influence of convective entrainment on the tropospheric lapse rate, and we demonstrate the importance of this influence for simulated CAPE extremes using a climate model in which the convective entrainment rate is varied. We further show that the theoretical model is able to account for the climatological relationship between CAPE and a measure of lower-tropospheric humidity in simulations and in observations. Our results provide a physical basis on which to understand projected future increases in intense thunderstorm potential, and they suggest that an important mechanism that contributes to such increases may be present in Earth’s atmosphere. PMID:29078312
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Zhu, Jinning; Xu, Xuan; Tao, Qing; Yi, Panpan; Yu, Dan; Xu, Xinwei
2017-07-01
Ecological niche modeling is an effective tool to characterize the spatial distribution of suitable areas for species, and it is especially useful for predicting the potential distribution of invasive species. The widespread submerged plant Hydrilla verticillata (hydrilla) has an obvious phylogeographical pattern: Four genetic lineages occupy distinct regions in native range, and only one lineage invades the Americas. Here, we aimed to evaluate climatic niche conservatism of hydrilla in North America at the intraspecific level and explore its invasion potential in the Americas by comparing climatic niches in a phylogenetic context. Niche shift was found in the invasion process of hydrilla in North America, which is probably mainly attributed to high levels of somatic mutation. Dramatic changes in range expansion in the Americas were predicted in the situation of all four genetic lineages invading the Americas or future climatic changes, especially in South America; this suggests that there is a high invasion potential of hydrilla in the Americas. Our findings provide useful information for the management of hydrilla in the Americas and give an example of exploring intraspecific climatic niche to better understand species invasion.
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Quantifying Direct and Indirect Impact of Future Climate on Sub-Arctic Hydrology
NASA Astrophysics Data System (ADS)
Endalamaw, A. M.; Bolton, W. R.; Young-Robertson, J. M.; Morton, D.; Hinzman, L. D.
2016-12-01
Projected future climate will have a significant impact on the hydrology of interior Alaskan sub-arctic watersheds, directly though the changes in precipitation and temperature patterns, and indirectly through the cryospheric and ecological impacts. Although the latter is the dominant factor controlling the hydrological processes in the interior Alaska sub-arctic, it is often overlooked in many climate change impact studies. In this study, we aim to quantify and compare the direct and indirect impact of the projected future climate on the hydrology of the interior Alaskan sub-arctic watersheds. The Variable Infiltration Capacity (VIC) meso-scale hydrological model will be implemented to simulate the hydrological processes, including runoff, evapotranspiration, and soil moisture dynamics in the Chena River Basin (area = 5400km2), located in the interior Alaska sub-arctic region. Permafrost and vegetation distribution will be derived from the Geophysical Institute Permafrost Lab (GIPL) model and the Lund-Potsdam-Jena Dynamic Global Model (LPJ) model, respectively. All models will be calibrated and validated using historical data. The Scenario Network for Alaskan and Arctic Planning (SNAP) 5-model average projected climate data products will be used as forcing data for each of these models. The direct impact of climate change on hydrology is estimated using surface parameterization derived from the present day permafrost and vegetation distribution, and future climate forcing from SNAP projected climate data products. Along with the projected future climate, outputs of GIPL and LPJ will be incorporated into the VIC model to estimate the indirect and overall impact of future climate on the hydrology processes in the interior Alaskan sub-arctic watersheds. Finally, we will present the potential hydrological and ecological changes by the end of the 21st century.
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Climate Influence on Emerging Risk Areas for Rift Valley Fever Epidemics in Tanzania.
Mweya, Clement N; Mboera, Leonard E G; Kimera, Sharadhuli I
2017-07-01
Rift Valley Fever (RVF) is a climate-related arboviral infection of animals and humans. Climate is thought to represent a threat toward emerging risk areas for RVF epidemics globally. The objective of this study was to evaluate influence of climate on distribution of suitable breeding habitats for Culex pipiens complex, potential mosquito vector responsible for transmission and distribution of disease epidemics risk areas in Tanzania. We used ecological niche models to estimate potential distribution of disease risk areas based on vectors and disease co-occurrence data approach. Climatic variables for the current and future scenarios were used as model inputs. Changes in mosquito vectors' habitat suitability in relation to disease risk areas were estimated. We used partial receiver operating characteristic and the area under the curves approach to evaluate model predictive performance and significance. Habitat suitability for Cx. pipiens complex indicated broad-scale potential for change and shift in the distribution of the vectors and disease for both 2020 and 2050 climatic scenarios. Risk areas indicated more intensification in the areas surrounding Lake Victoria and northeastern part of the country through 2050 climate scenario. Models show higher probability of emerging risk areas spreading toward the western parts of Tanzania from northeastern areas and decrease in the southern part of the country. Results presented here identified sites for consideration to guide surveillance and control interventions to reduce risk of RVF disease epidemics in Tanzania. A collaborative approach is recommended to develop and adapt climate-related disease control and prevention strategies.
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Impacts of changing ocean circulation on the distribution of marine microplastic litter.
Welden, Natalie Ac; Lusher, Amy L
2017-05-01
Marine plastic pollution is currently a major scientific focus, with attention paid to its distribution and impacts within ecosystems. With recent estimates indicating that the mass of plastic released to the marine environment may reach 250 million metric tons by 2025, the effects of plastic on our oceans are set to increase. Distribution of microplastics, those plastics measuring less than 5 mm, are of increasing concern because they represent an increasing proportion of marine litter and are known to interact with species in a range of marine habitats. The local abundance of microplastic is dependent on a complex interaction between the scale of local plastic sources and prevailing environmental conditions; as a result, microplastic distribution is highly heterogeneous. Circulation models have been used to predict plastic distribution; however, current models do not consider future variation in circulation patterns and weather systems caused by a changing climate. In this study, we discuss the potential impacts of global climate change on the abundance and distribution of marine plastic pollution. Integr Environ Assess Manag 2017;13:483-487. © 2017 SETAC. © 2017 SETAC.
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The distribution of physiotherapists in ontario: understanding the market drivers.
Holyoke, Paul; Verrier, Molly C; Landry, Michel D; Deber, Raisa B
2012-01-01
To understand the factors that affect the distribution of physiotherapists in Ontario by examining three potential influences in the multi-payer physiotherapy (PT) market: population need, critical mass (related to academic health science centres [AHSCs]), and market forces. Physiotherapist density and distribution were calculated from 2003 and 2005 College of Physiotherapists of Ontario registration data. Physiotherapists' workplaces were classified as not-for-profit (NFP) hospitals, other NFP, or for-profit (FP), and their locations were classified by census division (CD) types (cities and counties). Physiotherapist density varied significantly and distribution was neither uniformly responsive to population need, nor driven primarily by market forces. The largest factor was an AHSC in a CD; physiotherapists locate disproportionately in NFP hospitals in AHSCs rather than in the growing FP sector. While some patterns can be discerned in the distribution and densities of physiotherapists across Ontario, further work needs to be done to identify why population need and market forces appear to be less influential, and why CDs with AHSCs are so attractive to physiotherapists. With this additional information, it may be possible to identify ways to influence uneven distribution in the future.
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Haq, Shaji S; Kodak, Tiffany
2015-01-01
This study evaluated the effects of massed and distributed practice on the acquisition of tacts and textual behavior in typically developing children. We compared the effects of massed practice (i.e., consolidating all practice opportunities during the week into a single session) and distributed practice (i.e., distributing all practice opportunities across 4 sessions during the week) on the acquisition of textual behavior in English, tacting pictures of common nouns in Spanish, and textual behavior in Spanish using an adapted alternating treatments design embedded within a multiple probe design. We also examined correct responding during probes that (a) excluded prompts and reinforcement and (b) occurred 48 hr after training each week. The results indicated that distributed practice was the more efficient training format. Maintenance data collected up to 4 weeks after training also indicated that the participants consistently displayed higher levels of correct responding to targets that had been trained in distributed format. We discuss implications for practice and potential areas for future research. © Society for the Experimental Analysis of Behavior.
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NASA Astrophysics Data System (ADS)
Banzon, P. V. F.; Liu, G.; Forney, K.; Becker, E.; Arzayus, K. M.; Sun, L.
2016-02-01
The NOAA ¼° daily Optimum Interpolation (OI) Sea Surface temperature (SST), an in situ and satellite-based climate data record of SST available from 1981, was used to examine potential impacts of long-term temperature change on marine ecosystems. As a benthic example, historical heat stress in key tropical coral reef regions was calculated from the daily temperature data, using the NOAA Coral Reef Watch methodology. The regions with long-term ocean warming trend and experiencing more frequent thermal stress are identified as the regions with high vulnerability. While corals may be able to adapt to slow changes, no systematic adaptation has been reported with temperature increase over the past few decades. In contrast to the attached corals, marine mammals respond to changes in their environment by changing their distributions, often over large geographic areas. Habitat-based species distribution models can be developed to predict changes in the spatial distribution and abundance of marine mammals. OISST is a good predictor of the distribution of some marine mammal species, including Bryde's whales, false killer whales, and striped dolphins, and SST-based distribution models provide a foundation for projecting potential impacts of future temperature changes on marine mammals. Preliminary results from some of our research activities will be presented.
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Cheng, Rui; Xia, Li; Sima, Chaotan; Ran, Yanli; Rohollahnejad, Jalal; Zhou, Jiaao; Wen, Yongqiang; Yu, Can
2016-02-08
Ultrashort fiber Bragg gratings (US-FBGs) have significant potential as weak grating sensors for distributed sensing, but the exploitation have been limited by their inherent broad spectra that are undesirable for most traditional wavelength measurements. To address this, we have recently introduced a new interrogation concept using shifted optical Gaussian filters (SOGF) which is well suitable for US-FBG measurements. Here, we apply it to demonstrate, for the first time, an US-FBG-based self-referencing distributed optical sensing technique, with the advantages of adjustable sensitivity and range, high-speed and wide-range (potentially >14000 με) intensity-based detection, and resistance to disturbance by nonuniform parameter distribution. The entire system is essentially based on a microwave network, which incorporates the SOGF with a fiber delay-line between the two arms. Differential detections of the cascaded US-FBGs are performed individually in the network time-domain response which can be obtained by analyzing its complex frequency response. Experimental results are presented and discussed using eight cascaded US-FBGs. A comprehensive numerical analysis is also conducted to assess the system performance, which shows that the use of US-FBGs instead of conventional weak FBGs could significantly improve the power budget and capacity of the distributed sensing system while maintaining the crosstalk level and intensity decay rate, providing a promising route for future sensing applications.
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Silva, Daniel P.; Vilela, Bruno; De Marco, Paulo; Nemésio, André
2014-01-01
The role of past connections between the two major South American forested biomes on current species distribution has been recognized a long time ago. Climatic oscillations that further separated these biomes have promoted parapatric speciation, in which many species had their continuous distribution split, giving rise to different but related species (i.e., different potential distributions and realized niche features). The distribution of many sister species of orchid bees follow this pattern. Here, using ecological niche models and niche analyses, we (1) tested the role of ecological niche differentiation on the divergence between sister orchid-bees (genera Eulaema and Eufriesea) from the Amazon and Atlantic forests, and (2) highlighted interesting areas for new surveys. Amazonian species occupied different realized niches than their Atlantic sister species. Conversely, species of sympatric but distantly related Eulaema bees occupied similar realized niches. Amazonian species had a wide potential distribution in South America, whereas Atlantic Forest species were more limited to the eastern coast of the continent. Additionally, we identified several areas in need of future surveys. Our results show that the realized niche of Atlantic-Amazonian sister species of orchid bees, which have been previously treated as allopatric populations of three species, had limited niche overlap and similarity. These findings agree with their current taxonomy, which treats each of those populations as distinct valid species. PMID:25422941
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Potential distribution of dengue fever under scenarios of climate change and economic development.
Aström, Christofer; Rocklöv, Joacim; Hales, Simon; Béguin, Andreas; Louis, Valerie; Sauerborn, Rainer
2012-12-01
Dengue fever is the most important viral vector-borne disease with ~50 million cases per year globally. Previous estimates of the potential effect of global climate change on the distribution of vector-borne disease have not incorporated the effect of socioeconomic factors, which may have biased the results. We describe an empirical model of the current geographic distribution of dengue, based on the independent effects of climate and gross domestic product per capita (GDPpc, a proxy for socioeconomic development). We use the model, along with scenario-based projections of future climate, economic development, and population, to estimate populations at risk of dengue in the year 2050. We find that both climate and GDPpc influence the distribution of dengue. If the global climate changes as projected but GDPpc remained constant, the population at risk of dengue is estimated to increase by about 0.28 billion in 2050. However, if both climate and GDPpc change as projected, we estimate a decrease of 0.12 billion in the population at risk of dengue in 2050. Empirically, the geographic distribution of dengue is strongly dependent on both climatic and socioeconomic variables. Under a scenario of constant GDPpc, global climate change results in a modest but important increase in the global population at risk of dengue. Under scenarios of high GDPpc, this adverse effect of climate change is counteracted by the beneficial effect of socioeconomic development.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1979-09-01
Appendix A, Utility Plant Characteristics, contains information describing the characteristics of seven utility plants that were considered during the final site selection process. The plants are: Valley Electric Generating Plant, downtown Milwaukee; Manitowoc Electric Generating Plant, downtown Manitowoc; Blount Street Electric Generating Plant, downtown Madison; Pulliam Electric Generating Plant, downtown Green Bay; Edgewater Electric Generating Plant, downtown Sheboygan; Rock River Electric Generating Plant, near Janesville and Beloit; and Black Hawk Electric Generating Plant, downtown Beloit. Additional appendices are: Future Loads; hvac Inventory; Load Calculations; Factors to Induce Potential Users; Turbine Retrofit/Distribution System Data; and Detailed Economic Analysis Results/Data.
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Distributed augmented reality with 3-D lung dynamics--a planning tool concept.
Hamza-Lup, Felix G; Santhanam, Anand P; Imielińska, Celina; Meeks, Sanford L; Rolland, Jannick P
2007-01-01
Augmented reality (AR) systems add visual information to the world by using advanced display techniques. The advances in miniaturization and reduced hardware costs make some of these systems feasible for applications in a wide set of fields. We present a potential component of the cyber infrastructure for the operating room of the future: a distributed AR-based software-hardware system that allows real-time visualization of three-dimensional (3-D) lung dynamics superimposed directly on the patient's body. Several emergency events (e.g., closed and tension pneumothorax) and surgical procedures related to lung (e.g., lung transplantation, lung volume reduction surgery, surgical treatment of lung infections, lung cancer surgery) could benefit from the proposed prototype.
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On effectiveness of network sensor-based defense framework
NASA Astrophysics Data System (ADS)
Zhang, Difan; Zhang, Hanlin; Ge, Linqiang; Yu, Wei; Lu, Chao; Chen, Genshe; Pham, Khanh
2012-06-01
Cyber attacks are increasing in frequency, impact, and complexity, which demonstrate extensive network vulnerabilities with the potential for serious damage. Defending against cyber attacks calls for the distributed collaborative monitoring, detection, and mitigation. To this end, we develop a network sensor-based defense framework, with the aim of handling network security awareness, mitigation, and prediction. We implement the prototypical system and show its effectiveness on detecting known attacks, such as port-scanning and distributed denial-of-service (DDoS). Based on this framework, we also implement the statistical-based detection and sequential testing-based detection techniques and compare their respective detection performance. The future implementation of defensive algorithms can be provisioned in our proposed framework for combating cyber attacks.
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Measurement and validation of benchmark-quality thick-target tungsten X-ray spectra below 150 kVp.
Mercier, J R; Kopp, D T; McDavid, W D; Dove, S B; Lancaster, J L; Tucker, D M
2000-11-01
Pulse-height distributions of two constant potential X-ray tubes with fixed anode tungsten targets were measured and unfolded. The measurements employed quantitative alignment of the beam, the use of two different semiconductor detectors (high-purity germanium and cadmium-zinc-telluride), two different ion chamber systems with beam-specific calibration factors, and various filter and tube potential combinations. Monte Carlo response matrices were generated for each detector for unfolding the pulse-height distributions into spectra incident on the detectors. These response matrices were validated for the low error bars assigned to the data. A significant aspect of the validation of spectra, and a detailed characterization of the X-ray tubes, involved measuring filtered and unfiltered beams at multiple tube potentials (30-150 kVp). Full corrections to ion chamber readings were employed to convert normalized fluence spectra into absolute fluence spectra. The characterization of fixed anode pitting and its dominance over exit window plating and/or detector dead layer was determined. An Appendix of tabulated benchmark spectra with assigned error ranges was developed for future reference.
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Vanderduys, Eric Peter; Reside, April E.; Grice, Anthony; Rechetelo, Juliana
2016-01-01
Where threatened biodiversity is adversely affected by development, policies often state that "no net loss" should be the goal and biodiversity offsetting is one mechanism available to achieve this. However, developments are often approved on an ad hoc basis and cumulative impacts are not sufficiently examined. We demonstrate the potential for serious threat to an endangered subspecies when multiple developments are planned. We modelled the distribution of the black-throated finch (Poephila cincta cincta) using bioclimatic data and Queensland's Regional Ecosystem classification. We overlaid granted, extant extractive and exploratory mining tenures within the known and modelled ranges of black-throated finches to examine the level of incipient threat to this subspecies in central Queensland, Australia. Our models indicate that more than half of the remaining P. cincta cincta habitat is currently under extractive or exploratory tenure. Therefore, insufficient habitat exists to offset all potential development so "no net loss" is not possible. This has implications for future conservation of this and similarly distributed species and for resource development planning, especially the use of legislated offsets for biodiversity protection. PMID:26934622
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Preservation of Reduced Carbon on Mars: Implications for Understanding Habitability
NASA Technical Reports Server (NTRS)
Conrad, Pamela; Fogel, Marilyn; Steele, Andrew; Summons, Roger E.
2007-01-01
Upcoming Mars missions (e.g., Mars Science Laboratory, ExoMars, Astrobiology Field Laboratory, and Mars Sample Return) will search for evidence of extant and fossil microbial habitats and the potential for future habitation. Understanding the distribution and composition of reduced carbon (or organic carbon) is critical for unraveling the Martian carbon cycle, potential for life, and possible biosignature record. Reduced carbon may be produced from biological, geochemical, or interstellar processes; however, evidence for reduced carbon on Mars is lacking with the exception of parts per billion of atmospheric methane. In contrast, abundant atmospheric carbon dioxide may reflect surface oxidation of reduced carbon and accumulation over geological timescales. This suggests that there is an undetected or lost pool of reduced carbon - a pool that may host molecular biosignatures, a characteristic of extant or extinct habitability. In this presentation, we will evaluate factors influencing the preservation potential for organic molecules in rocks on Earth and Martian. We,draw examples from organic molecules in sulfates, basalts, and ancient shales from Mars-analog settings to show how the distribution of organics and their structural patterns will aid Mars habitability studies.
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Castellani, Cristina; Arnoldi, Daniele; Rizzoli, Annapaola
2011-01-01
Background The tiger mosquito (Aedes albopictus), vector of several emerging diseases, is expanding into more northerly latitudes as well as into higher altitudes in northern Italy. Changes in the pattern of distribution of the tiger mosquito may affect the potential spread of infectious diseases transmitted by this species in Europe. Therefore, predicting suitable areas of future establishment and spread is essential for planning early prevention and control strategies. Methodology/Principal Findings To identify the areas currently most suitable for the occurrence of the tiger mosquito in the Province of Trento, we combined field entomological observations with analyses of satellite temperature data (MODIS Land Surface Temperature: LST) and human population data. We determine threshold conditions for the survival of overwintering eggs and for adult survival using both January mean temperatures and annual mean temperatures. We show that the 0°C LST threshold for January mean temperatures and the 11°C threshold for annual mean temperatures provide the best predictors for identifying the areas that could potentially support populations of this mosquito. In fact, human population density and distance to human settlements appear to be less important variables affecting mosquito distribution in this area. Finally, we evaluated the future establishment and spread of this species in relation to predicted climate warming by considering the A2 scenario for 2050 statistically downscaled at regional level in which winter and annual temperatures increase by 1.5 and 1°C, respectively. Conclusions/Significance MODIS satellite LST data are useful for accurately predicting potential areas of tiger mosquito distribution and for revealing the range limits of this species in mountainous areas, predictions which could be extended to an European scale. We show that the observed trend of increasing temperatures due to climate change could facilitate further invasion of Ae. albopictus into new areas. PMID:21525991
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Towards a 3d Spatial Urban Energy Modelling Approach
NASA Astrophysics Data System (ADS)
Bahu, J.-M.; Koch, A.; Kremers, E.; Murshed, S. M.
2013-09-01
Today's needs to reduce the environmental impact of energy use impose dramatic changes for energy infrastructure and existing demand patterns (e.g. buildings) corresponding to their specific context. In addition, future energy systems are expected to integrate a considerable share of fluctuating power sources and equally a high share of distributed generation of electricity. Energy system models capable of describing such future systems and allowing the simulation of the impact of these developments thus require a spatial representation in order to reflect the local context and the boundary conditions. This paper describes two recent research approaches developed at EIFER in the fields of (a) geo-localised simulation of heat energy demand in cities based on 3D morphological data and (b) spatially explicit Agent-Based Models (ABM) for the simulation of smart grids. 3D city models were used to assess solar potential and heat energy demand of residential buildings which enable cities to target the building refurbishment potentials. Distributed energy systems require innovative modelling techniques where individual components are represented and can interact. With this approach, several smart grid demonstrators were simulated, where heterogeneous models are spatially represented. Coupling 3D geodata with energy system ABMs holds different advantages for both approaches. On one hand, energy system models can be enhanced with high resolution data from 3D city models and their semantic relations. Furthermore, they allow for spatial analysis and visualisation of the results, with emphasis on spatially and structurally correlations among the different layers (e.g. infrastructure, buildings, administrative zones) to provide an integrated approach. On the other hand, 3D models can benefit from more detailed system description of energy infrastructure, representing dynamic phenomena and high resolution models for energy use at component level. The proposed modelling strategies conceptually and practically integrate urban spatial and energy planning approaches. The combined modelling approach that will be developed based on the described sectorial models holds the potential to represent hybrid energy systems coupling distributed generation of electricity with thermal conversion systems.
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York, Emily M; Butler, Christopher J; Lord, Wayne D
2014-01-01
Climate change is implicated in the alteration of the ranges of species worldwide. Such shifts in species distributions may introduce parasites/pathogens, hosts, and vectors associated with disease to new areas. The parasite Angiostrongylus ( = Parastrongylus) cantonensis is an invasive species that causes eosinophilic meningitis in humans and neurological abnormalities in domestic/wild animals. Although native to southeastern Asia, A. cantonensis has now been reported from more than 30 countries worldwide. Given the health risks, it is important to describe areas with potentially favorable climate for the establishment of A. cantonensis, as well as areas where this pathogen might become established in the future. We used the program Maxent to develop an ecological niche model for A. cantonensis based on 86 localities obtained from published literature. We then modeled areas of potential A. cantonensis distribution as well as areas projected to have suitable climatic conditions under four Representative Concentration Pathways (RCP) scenarios by the 2050s and the 2070s. The best model contained three bioclimatic variables: mean diurnal temperature range, minimum temperature of coldest month and precipitation of warmest quarter. Potentially suitable habitat for A. cantonensis was located worldwide in tropical and subtropical regions. Under all climate change RCP scenarios, the center of the projected distribution shifted away from the equator at a rate of 68-152 km per decade. However, the extent of areas with highly suitable habitat (>50%) declined by 10.66-15.66% by the 2050s and 13.11-16.11% by the 2070s. These results conflict with previous studies, which have generally found that the prevalence of tropical pathogens will increase during the 21st century. Moreover, it is likely that A. cantonensis will continue to expand its current range in the near future due to introductions and host expansion, whereas climate change will reduce the total geographic area of most suitable climatic conditions during the coming decades.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Barnes, P.R.; Van Dyke, J.W; McConnell, B.W.
It is estimated that electric utilities use about 40 million distribution transformers in supplying electricity to customers in the United States. Although utility distribution transformers collectively have a high average efficiency, they account for approximately 61 billion kWh of the 229 billion kWh of energy lost annually in the delivery of electricity. Distribution transformers are being replaced over time by new, more efficient, lower-loss units during routine utility maintenance of power distribution systems. Maintenance is typically not performed on units in service. However, units removed from service with appreciable remaining life are often refurbished and returned to stock. Distribution transformersmore » may be removed from service for many reasons, including failure, over- or underloading, or line upgrades such as voltage changes or rerouting. When distribution transformers are removed from service, a decision must be made whether to dispose of the transformer and purchase a lower-loss replacement or to refurbish the transformer and return it to stock for future use. This report contains findings and recommendations on replacing utility distribution transformers during routine maintenance, which is required by section 124 of the Energy Policy Act of 1992. The objectives of the study are to evaluate the practicability, cost-effectiveness, and potential energy savings of replacing or upgrading existing transformers during routine utility maintenance and to develop recommendations on ways to achieve the potential energy savings. Using survey data obtained from utilities and analyses of the economics of refurbishment versus replacement of distribution transformers that are removed from service, it is found that on average utilities are implementing reasonable decisions on refurbishment versus replacement.« less
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NASA Astrophysics Data System (ADS)
Bachelet, D. M.; Ferschweiler, K.; Baker, B.; Sleeter, B. M.
2016-12-01
Climate variability and a warming trend during the 21st century ensures fuel build-up and episodic catastrophic wildfires. We used downscaled (2.5 arcmin) CMIP5 climate futures from 20 models under RCP 8.5 to run the dynamic global vegetation model MC2 over the conterminous US and identify key drivers of land cover change. We show regional and temporal differences in the magnitude of projected C losses due to fire over the 21st century. We also look at the vigor (NPP/LAI) of forest lands and estimate the loss in C capture due to declines in production as well as the increase in heterotrophic respiration due to increased mortality. We compare simulated the carbon sequestration potential of terrestrial biomes and the risk of carbon losses through disturbance. We quantify uncertainty in model results by showing the distribution of possible future impacts under 20 futures. We explore the effects of land use and highlight the challenges we met to simulate credible transient management practices throughout the 20th century and into the future.
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Chicoric acid: chemistry, distribution, and production
NASA Astrophysics Data System (ADS)
Lee, Jungmin; Scagel, Carolyn
2013-12-01
Though chicoric acid was first identified in 1958, it was largely ignored until recent popular media coverage cited potential health beneficial properties from consuming food and dietary supplements containing this compound. To date, plants from at least 63 genera and species have been found to contain chicoric acid, and while the compound is used as a processing quality indicator, it may also have useful health benefits. This review of chicoric acid summarizes research findings and highlights gaps in research knowledge for investigators, industry stakeholders, and consumers alike. Additionally, chicoric acid identification and quantification methods, biosynthesis, processing improvements to increase chicoric acid retention, and potential areas for future research are discussed.
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Chicoric acid: chemistry, distribution, and production.
Lee, Jungmin; Scagel, Carolyn F
2013-01-01
Though chicoric acid was first identified in 1958, it was largely ignored until recent popular media coverage cited potential health beneficial properties from consuming food and dietary supplements containing this compound. To date, plants from at least 63 genera and species have been found to contain chicoric acid, and while the compound is used as a processing quality indicator, it may also have useful health benefits. This review of chicoric acid summarizes research findings and highlights gaps in research knowledge for investigators, industry stakeholders, and consumers alike. Additionally, chicoric acid identification, and quantification methods, biosynthesis, processing improvements to increase chicoric acid retention, and potential areas for future research are discussed.
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Chicoric acid: chemistry, distribution, and production
Lee, Jungmin; Scagel, Carolyn F.
2013-01-01
Though chicoric acid was first identified in 1958, it was largely ignored until recent popular media coverage cited potential health beneficial properties from consuming food and dietary supplements containing this compound. To date, plants from at least 63 genera and species have been found to contain chicoric acid, and while the compound is used as a processing quality indicator, it may also have useful health benefits. This review of chicoric acid summarizes research findings and highlights gaps in research knowledge for investigators, industry stakeholders, and consumers alike. Additionally, chicoric acid identification, and quantification methods, biosynthesis, processing improvements to increase chicoric acid retention, and potential areas for future research are discussed. PMID:24790967
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The State, Potential Distribution, and Biological Implications of Methane in the Martian Crust
NASA Technical Reports Server (NTRS)
Max, Michael D.; Clifford, Stephen M.
2000-01-01
The search for life on Mars has recently focused on its potential survival in deep (>2 km) subpermafrost aquifers where anaerobic bacteria, similar to those found in deep subsurface ecosystems on Earth, may have survived in an environment that has remained stable for billions of years. An anticipated by-product of this biological activity is methane. The detection of large deposits of methane gas and hydrate in the Martian cryosphere, or as emissions from deep fracture zones, would provide persuasive evidence of indigenous life and confirm the presence of a valuable in situ resource for use by future human explorers.
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NASA Astrophysics Data System (ADS)
Hevesi, J. A.; Woolfenden, L. R.; Nishikawa, T.
2014-12-01
Communities in the Santa Rosa Plain watershed (SRPW), Sonoma County, CA, USA are experiencing increasing demand for limited water resources. Streamflow in the SRPW is runoff dominated; however, groundwater also is an important resource in the basin. The watershed has an area of 262 mi2 that includes natural, agricultural, and urban land uses. To evaluate the hydrologic system, an integrated hydrologic model was developed using the U.S. Geological Survey coupled groundwater and surface-water flow model, GSFLOW. The model uses a daily time step and a grid-based discretization of the SRPW consisting of 16,741 10-acre cells for 8 model layers to simulate all water budget components of the surface and subsurface hydrologic system. Simulation results indicate significant impacts on streamflow and recharge in response to the below average precipitation during the dry periods. The recharge and streamflow distributions simulated for historic dry periods were compared to future dry periods projected from 4 GCM realizations (two different GCMs and two different CO2 forcing scenarios) for the 21st century, with the dry periods defined as 3 consecutive years of below average precipitation. For many of the projected dry periods, the decreases in recharge and streamflow were greater than for the historic dry periods due to a combination of lower precipitation and increases in simulated evapotranspiration for the warmer 21st century projected by the GCM realizations. The greatest impact on streamflow for both historic and projected future dry periods is the diminished baseflow from late spring to early fall, with an increase in the percentage of intermittent and dry stream reaches. The results indicate that the coupled model is a useful tool for water managers to better understand the potential effects of future dry periods on spatially and temporally distributed streamflow and recharge, as well as other components of the water budget.
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Assessment of Folsom Lake Watershed response to historical and potential future climate scenarios
Carpenter, Theresa M.; Georgakakos, Konstantine P.
2000-01-01
An integrated forecast-control system was designed to allow the profitable use of ensemble forecasts for the operational management of multi-purpose reservoirs. The system ingests large-scale climate model monthly precipitation through the adjustment of the marginal distribution of reservoir-catchment precipitation to reflect occurrence of monthly climate precipitation amounts in the extreme terciles of their distribution. Generation of ensemble reservoir inflow forecasts is then accomplished with due account for atmospheric- forcing and hydrologic- model uncertainties. These ensemble forecasts are ingested by the decision component of the integrated system, which generates non- inferior trade-off surfaces and, given management preferences, estimates of reservoir- management benefits over given periods. In collaboration with the Bureau of Reclamation and the California Nevada River Forecast Center, the integrated system is applied to Folsom Lake in California to evaluate the benefits for flood control, hydroelectric energy production, and low flow augmentation. In addition to retrospective studies involving the historical period 1964-1993, system simulations were performed for the future period 2001-2030, under a control (constant future greenhouse-gas concentrations assumed at the present levels) and a greenhouse-gas- increase (1-% per annum increase assumed) scenario. The present paper presents and validates ensemble 30-day reservoir- inflow forecasts under a variety of situations. Corresponding reservoir management results are presented in Yao and Georgakakos, A., this issue. Principle conclusions of this paper are that the integrated system provides reliable ensemble inflow volume forecasts at the 5-% confidence level for the majority of the deciles of forecast frequency, and that the use of climate model simulations is beneficial mainly during high flow periods. It is also found that, for future periods with potential sharp climatic increases of precipitation amount and to maintain good reliability levels, operational ensemble inflow forecasting should involve atmospheric forcing from appropriate climatic periods.
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Predicted extinction of unique genetic diversity in marine forests of Cystoseira spp.
Buonomo, Roberto; Chefaoui, Rosa M; Lacida, Ricardo Bermejo; Engelen, Aschwin H; Serrão, Ester A; Airoldi, Laura
2018-07-01
Climate change is inducing shifts in species ranges across the globe. These can affect the genetic pools of species, including loss of genetic variability and evolutionary potential. In particular, geographically enclosed ecosystems, like the Mediterranean Sea, have a higher risk of suffering species loss and genetic erosion due to barriers to further range shifts and to dispersal. In this study, we address these questions for three habitat-forming seaweed species, Cystoseira tamariscifolia, C. amentacea and C. compressa, throughout their entire ranges in the Atlantic and Mediterranean regions. We aim to 1) describe their population genetic structure and diversity, 2) model the present and predict the future distribution and 3) assess the consequences of predicted future range shifts for their population genetic structure, according to two contrasting future climate change scenarios. A net loss of suitable areas was predicted in both climatic scenarios across the range of distribution of the three species. This loss was particularly severe for C. amentacea in the Mediterranean Sea (less 90% in the most extreme climatic scenario), suggesting that the species could become potentially at extinction risk. For all species, genetic data showed very differentiated populations, indicating low inter-population connectivity, and high and distinct genetic diversity in areas that were predicted to become lost, causing erosion of unique evolutionary lineages. Our results indicated that the Mediterranean Sea is the most threatened region, where future suitable Cystoseira habitats will become more limited. This is likely to have wider ecosystem impacts as there is a lack of species with the same ecological niche and functional role in the Mediterranean. The projected accelerated loss of already fragmented and disturbed populations and the long-term genetic effects highlight the urge for local scale management strategies that sustain the capacity of these habitat-forming species to persist despite climatic impacts while waiting for global emission reductions. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Li, Yao; Zhang, Xing-wang; Fang, Yan-ming
2014-12-01
The geographical distribution of Quercus variabilis in China with its climate characteristics was analyzed based on DIVA-GIS which was also used to estimate the response of future potential distribution to global warming by Bioclim and Domain models. Analysis results showed the geographical distribution of Q. variabilis could be divided into 7 subregions: Henduan Mountains, Yunnan-Guizhou Plateau, North China, East China, Liaodong-Shandong Peninsula, Taiwan Island, and Qinling-Daba Mountains. These subregions are across 7 temperature zones, 2 moisture regions and 17 climatic subregions, including 8 climate types. The modern abundance center of Q. variabilis is Qinling, Daba and Funiu mountains. The condition of mean annual temperature 7.5-19.8 degrees C annual precipitation 471-1511 mm, is suitable for Q. variabilis. Areas under the receiver operating characteristic curve (AUC values), of Domain and Boiclim models were 0.910, 0.779; the former predicted that the potential regions of high suitability for Q. variabilis are Qinling, Daba, Funiu, Tongbai, and Dabie mountains, eastern and western Yunnan-Guizhou Plateau, hills of southern Jiangsu and Anhui, part of the mountains in North China. Global warming might lead to the shrinking in suitable region and retreating from the south for Q. variabilis.
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Adjemian, Jennifer C Z; Girvetz, Evan H; Beckett, Laurel; Foley, Janet E
2006-01-01
More than 20 species of fleas in California are implicated as potential vectors of Yersinia pestis. Extremely limited spatial data exist for plague vectors-a key component to understanding where the greatest risks for human, domestic animal, and wildlife health exist. This study increases the spatial data available for 13 potential plague vectors by using the ecological niche modeling system Genetic Algorithm for Rule-Set Production (GARP) to predict their respective distributions. Because the available sample sizes in our data set varied greatly from one species to another, we also performed an analysis of the robustness of GARP by using the data available for flea Oropsylla montana (Baker) to quantify the effects that sample size and the chosen explanatory variables have on the final species distribution map. GARP effectively modeled the distributions of 13 vector species. Furthermore, our analyses show that all of these modeled ranges are robust, with a sample size of six fleas or greater not significantly impacting the percentage of the in-state area where the flea was predicted to be found, or the testing accuracy of the model. The results of this study will help guide the sampling efforts of future studies focusing on plague vectors.
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Responding Logistically to Future Natural and Man-Made Disasters and Catastrophes
2008-03-15
Logistics Operations, Plans and Exercises, Distribution Management and Property Management. Each competency has associated roles, missions and...professional development. LMD’s Distribution Management Division (DMD) Within the LMD, FEMA also created the Distribution Management Division (DMD...to stock in anticipation of future disasters. A Distribution Management Strategy Working Group was formed with Federal, private and nongovernmental
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Crichigno, S; Cordero, P; Blasetti, G; Cussac, V
2016-07-01
Common carp Cyprinus carpio possess multiple traits that contribute to their success as an invasive species. They have been introduced across the globe, and abundant populations can have numerous negative effects. Although ecological niche-based modelling techniques have been used to predict the potential range of C. carpio invasion in U.S.A., occurrence and abundance patterns have not yet been considered on a regional scale. In the present review new locations are documented, the status of the southernmost population has been studied and the probability of new lakes and reservoirs being colonized by C. carpio has been obtained and related to environmental conditions. The new localities for C. carpio have expanded its distribution westward, into the Andean Region, and present results from the South American southernmost population have shown a well-established population. Analysis of presence data provided two principal results: (1) the probability of a site being with C. carpio can be inferred using environmental variables and (2) the probability of a site being with C. carpio is a useful tool for the prediction of future invasions. Selective fishing on the Negro basin could constitute a potential mitigation measure, decreasing the abundance of the species and thus reducing the species' potential for southward expansion. These results reinforce the idea that artisanal fisheries, food production and conservation interests should be taken into account by local government management agencies in any discussion regarding the southern distribution of C. carpio in the near future. © 2016 The Fisheries Society of the British Isles.
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NASA Astrophysics Data System (ADS)
Soja, A. J.; Tchebakova, N. M.; Parfenova, E. I.; Cantin, A.; Conard, S. G.
2015-12-01
Global GCMs have demonstrated profound potential for projections to affect the distribution of terrestrial ecosystems and individual species at all hierarchical levels. We modeled progression of potential Russian ecotones and forest-forming species as the climate changes. Large-scale bioclimatic models were developed to predict Russian zonal vegetation (RuBCliM) and forest types (ForCliM) from three bioclimatic indices (1) growing degree-days above 5 degrees C; (2) negative degree-days below 0 C ; and (3) an annual moisture index (ratio of growing degree days to annual precipitation). The presence or absence of continuous permafrost was explicitly included in the models as limiting the forests and tree species distribution. All simulations to predict vegetation change across Russia were run by coupling our bioclimatic models with bioclimatic indices and the permafrost distribution for the baseline period and for the future 2020, 2050 and 2100 simulated by 3 GCMs (CGCM3.1, HadCM3 and IPSLCM4) and 3 climate change scenarios (A1B, A2 and B1). Under these climate scenarios, it is projected the zonobiomes will shift far northward to reach equilibrium with the change in climate. Under the warmer and drier projected future climate, about half of Russia would be suitable for the forest-steppe ecotone and grasslands, rather than for forests. Water stress tolerant light-needled taiga would have an increased advantage over water-loving dark-needled taiga. Permafrost-tolerant L. dahurica taiga would remain the dominant forest across permafrost. Increases in severe fire weather would lead to increases in large, high-severity fires, especially at boundaries between forest ecotones, which can be expected to facilitate a more rapid progression of vegetation towards a new equilibrium with the climate. Adaptation to climate change may be facilitated by: assisting migration of forests by seed transfers to establish genotypes that may be more ecologically suited as climate changes; and the introduction of suitable agricultural crops that may be potentially adapted to a warmer climate in the expected steppe and forest-steppe.
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The economics (or lack thereof) of aerosol geoengineering
NASA Astrophysics Data System (ADS)
Goes, M.; Keller, K.; Tuana, N.
2009-04-01
Anthropogenic greenhouse gas emissions are changing the Earth's climate and impose substantial risks for current and future generations. What are scientifically sound, economically viable, and ethically defendable strategies to manage these climate risks? Ratified international agreements call for a reduction of greenhouse gas emissions to avoid dangerous anthropogenic interference with the climate system. Recent proposals, however, call for the deployment of a different approach: to geoengineer climate by injecting aerosol precursors into the stratosphere. Published economic studies typically suggest that substituting aerosol geoengineering for abatement of carbon dioxide emissions results in large net monetary benefits. However, these studies neglect the risks of aerosol geoengineering due to (i) the potential for future geoengineering failures and (ii) the negative impacts associated with the aerosol forcing. Here we use a simple integrated assessment model of climate change to analyze potential economic impacts of aerosol geoengineering strategies over a wide range of uncertain parameters such as climate sensitivity, the economic damages due to climate change, and the economic damages due to aerosol geoengineering forcing. The simplicity of the model provides the advantages of parsimony and transparency, but it also imposes severe caveats on the interpretation of the results. For example, the analysis is based on a globally aggregated model and is hence silent on the question of intragenerational distribution of costs and benefits. In addition, the analysis neglects the effects of endogenous learning about the climate system. We show that the risks associated with a future geoengineering failure and negative impacts of aerosol forcings can cause geoenginering strategies to fail an economic cost-benefit test. One key to this finding is that a geoengineering failure would lead to dramatic and abrupt climatic changes. The monetary damages due to this failure can dominate the cost-benefit analysis because the monetary damages of climate change are expected to increase with the rate of change. Substituting aerosol geoengineering for greenhouse gas emission abatement might fail not only an economic cost-benefit test but also an ethical test of distributional justice. Substituting aerosol geoengineering for greenhouse gas emissions abatements constitutes a conscious risk transfer to future generations. Intergenerational justice demands distributional justice, namely that present generations may not create benefits for themselves in exchange for burdens on future generations. We use the economic model to quantify this risk transfer to better inform the judgment of whether substituting aerosol geoengineering for carbon dioxide emission abatement fails this ethical test.
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Projected future changes in vegetation in western North America in the 21st century
Xiaoyan, Jiang; Rauscher, Sara A.; Ringler, Todd D.; Lawrence, David M.; Williams, A. Park; Allen, Craig D.; Steiner, Allison L.; Cai, D. Michael; McDowell, Nate G.
2013-01-01
Rapid and broad-scale forest mortality associated with recent droughts, rising temperature, and insect outbreaks has been observed over western North America (NA). Climate models project additional future warming and increasing drought and water stress for this region. To assess future potential changes in vegetation distributions in western NA, the Community Earth System Model (CESM) coupled with its Dynamic Global Vegetation Model (DGVM) was used under the future A2 emissions scenario. To better span uncertainties in future climate, eight sea surface temperature (SST) projections provided by phase 3 of the Coupled Model Intercomparison Project (CMIP3) were employed as boundary conditions. There is a broad consensus among the simulations, despite differences in the simulated climate trajectories across the ensemble, that about half of the needleleaf evergreen tree coverage (from 24% to 11%) will disappear, coincident with a 14% (from 11% to 25%) increase in shrubs and grasses by the end of the twenty-first century in western NA, with most of the change occurring over the latter half of the twenty-first century. The net impact is a ~6 GtC or about 50% decrease in projected ecosystem carbon storage in this region. The findings suggest a potential for a widespread shift from tree-dominated landscapes to shrub and grass-dominated landscapes in western NA because of future warming and consequent increases in water deficits. These results highlight the need for improved process-based understanding of vegetation dynamics, particularly including mortality and the subsequent incorporation of these mechanisms into earth system models to better quantify the vulnerability of western NA forests under climate change.
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NASA Astrophysics Data System (ADS)
Wang, L.; Kerr, L. A.; Bridger, E.
2016-12-01
Changes in species distributions have been widely associated with climate change. Understanding how ocean conditions influence marine fish distributions is critical for elucidating the role of climate in ecosystem change and forecasting how fish may be distributed in the future. Species distribution models (SDMs) can enable estimation of the likelihood of encountering species in space or time as a function of environmental conditions. Traditional SDMs are applied to scientific-survey data that include both presences and absences. Maximum entropy (MaxEnt) models are promising tools as they can be applied to presence-only data, such as those collected from fisheries or citizen science programs. We used MaxEnt to relate the occurrence records of marine fish species (e.g. Atlantic herring, Atlantic mackerel, and butterfish) from NOAA Northeast Fisheries Observer Program to environmental conditions. Environmental variables from earth system data, such as sea surface temperature (SST), sea bottom temperature (SBT), Chlorophyll-a, bathymetry, North Atlantic oscillation (NAO), and Atlantic multidecadal oscillation (AMO), were matched with species occurrence for MaxEnt modeling the fish distributions in Northeast Shelf area. We developed habitat suitability maps for these species, and assessed the relative influence of environmental factors on their distributions. Overall, SST and Chlorophyll-a had greatest influence on their monthly distributions, with bathymetry and SBT having moderate influence and climate indices (NAO and AMO) having little influence. Across months, Atlantic herring distribution was most related to SST 10th percentile, and Atlantic mackerel and butterfish distributions were most related to previous month SST. The fish distributions were most affected by previous month Chlorophyll-a in summer months, which may indirectly indicate the accumulative impact of primary productivity. Results highlighted the importance of spatial and temporal scales when using SDMs to investigate the habitat suitability and distributions of a focal species. MaxEnt models have the potential to provide hindcasts of where species might have been in the past in relation to historical environmental conditions, nowcasts in relation to current conditions, or forecasts of future species distributions.
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The future of the New Zealand plastic surgery workforce.
Adams, Brandon M; Klaassen, Michael F; Tan, Swee T
2013-04-05
The New Zealand (NZ) plastic and reconstructive surgery (PRS) workforce provides reconstructive plastic surgery (RPS) public services from six centres. There has been little analysis on whether the workforce is adequate to meet the needs of the NZ population currently or in the future. This study analysed the current workforce, its distribution and future requirements. PRS manpower data, workforce activities, population statistics, and population modelling were analysed to determine current needs and predict future needs for the PRS workforce. The NZ PRS workforce is compared with international benchmarks. Regional variation of the workforce was analysed with respect to the population's access to PRS services. Future supply of specialist plastic surgeons is analysed. NZ has a lower number of plastic surgeons per capita than comparable countries. The current NZ PRS workforce is mal-distributed. Areas of current and emerging future need are identified. The current workforce mal-distribution will worsen with future population growth and distribution. Up to 60% of the NZ population will be at risk of inadequate access to PRS services by 2027. Development of PRS services must be coordinated to ensure that equitable and sustainable services are available throughout NZ. Strategies for ensuring satisfactory future workforce are discussed.
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Regional Landslide Hazard Assessment Considering Potential Climate Change
NASA Astrophysics Data System (ADS)
Almeida, S.; Holcombe, E.; Pianosi, F.; Wagener, T.
2016-12-01
Landslides have many negative economic and societal impacts, including the potential for significant loss of life and damage to infrastructure. These risks are likely to be exacerbated in the future by a combination of climatic and socio-economic factors. Climate change, for example, is expected to increase the occurrence of rainfall-triggered landslides, because a warmer atmosphere tends to produce more high intensity rainfall events. Prediction of future changes in rainfall, however, is subject to high levels of uncertainty, making it challenging for decision-makers to identify the areas and populations that are most vulnerable to landslide hazards. In this study, we demonstrate how a physically-based model - the Combined Hydrology and Stability Model (CHASM) - can be used together with Global Sensitivity Analysis (GSA) to explore the underlying factors controlling the spatial distribution of landslide risks across a regional landscape, while also accounting for deep uncertainty around potential future rainfall triggers. We demonstrate how GSA can be used to analyse CHASM which in turn represents the spatial variability of hillslope characteristics in the study region, while accounting for other uncertainties. Results are presented in the form of landslide hazard maps, utilising high-resolution digital elevation datasets for a case study in St Lucia in the Caribbean. Our findings about spatial landslide hazard drivers have important implications for data collection approaches and for long-term decision-making about land management practices.
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Gowthaman, Sivakumar; Nakashima, Kazunori; Kawasaki, Satoru
2018-04-04
Incorporating sustainable materials into geotechnical applications increases day by day due to the consideration of impacts on healthy geo-environment and future generations. The environmental issues associated with conventional synthetic materials such as cement, plastic-composites, steel and ashes necessitate alternative approaches in geotechnical engineering. Recently, natural fiber materials in place of synthetic material have gained momentum as an emulating soil-reinforcement technique in sustainable geotechnics. However, the natural fibers are innately different from such synthetic material whereas behavior of fiber-reinforced soil is influenced not only by physical-mechanical properties but also by biochemical properties. In the present review, the applicability of natural plant fibers as oriented distributed fiber-reinforced soil (ODFS) and randomly distributed fiber-reinforced soil (RDFS) are extensively discussed and emphasized the inspiration of RDFS based on the emerging trend. Review also attempts to explore the importance of biochemical composition of natural-fibers on the performance in subsoil reinforced conditions. The treatment methods which enhances the behavior and lifetime of fibers, are also presented. While outlining the current potential of fiber reinforcement technology, some key research gaps have been highlighted at their importance. Finally, the review briefly documents the future direction of the fiber reinforcement technology by associating bio-mediated technological line.
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Finn, C A; Sisson, T W; Deszcz-Pan, M
2001-02-01
Hydrothermally altered rocks can weaken volcanoes, increasing the potential for catastrophic sector collapses that can lead to destructive debris flows. Evaluating the hazards associated with such alteration is difficult because alteration has been mapped on few active volcanoes and the distribution and severity of subsurface alteration is largely unknown on any active volcano. At Mount Rainier volcano (Washington, USA), collapses of hydrothermally altered edifice flanks have generated numerous extensive debris flows and future collapses could threaten areas that are now densely populated. Preliminary geological mapping and remote-sensing data indicated that exposed alteration is contained in a dyke-controlled belt trending east-west that passes through the volcano's summit. But here we present helicopter-borne electromagnetic and magnetic data, combined with detailed geological mapping, to show that appreciable thicknesses of mostly buried hydrothermally altered rock lie mainly in the upper west flank of Mount Rainier. We identify this as the likely source for future large debris flows. But as negligible amounts of highly altered rock lie in the volcano's core, this might impede collapse retrogression and so limit the volumes and inundation areas of future debris flows. Our results demonstrate that high-resolution geophysical and geological observations can yield unprecedented views of the three-dimensional distribution of altered rock.
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Moncrieff, Glenn R; Scheiter, Simon; Bond, William J; Higgins, Steven I
2014-02-01
The dominant vegetation over much of the global land surface is not predetermined by contemporary climate, but also influenced by past environmental conditions. This confounds attempts to predict current and future biome distributions, because even a perfect model would project multiple possible biomes without knowledge of the historical vegetation state. Here we compare the distribution of tree- and grass-dominated biomes across Africa simulated using a dynamic global vegetation model (DGVM). We explicitly evaluate where and under what conditions multiple stable biome states are possible for current and projected future climates. Our simulation results show that multiple stable biomes states are possible for vast areas of tropical and subtropical Africa under current conditions. Widespread loss of the potential for multiple stable biomes states is projected in the 21st Century, driven by increasing atmospheric CO2 . Many sites where currently both tree-dominated and grass-dominated biomes are possible become deterministically tree-dominated. Regions with multiple stable biome states are widespread and require consideration when attempting to predict future vegetation changes. Testing for behaviour characteristic of systems with multiple stable equilibria, such as hysteresis and dependence on historical conditions, and the resulting uncertainty in simulated vegetation, will lead to improved projections of global change impacts. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.
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Aerogeophysical measurements of collapse-prone hydrothermally altered zones at Mount Rainier volcano
Finn, C.A.; Sisson, T.W.; Deszcz-Pan, M.
2001-01-01
Hydrothermally altered rocks can weaken volcanoes, increasing the potential for catastrophic sector collapses that can lead to destructive debris flows1. Evaluating the hazards associated with such alteration is difficult because alteration has been mapped on few active volcanoes1-4 and the distribution and severity of subsurface alteration is largely unknown on any active volcano. At Mount Rainier volcano (Washington, USA), collapses of hydrothermally altered edifice flanks have generated numerous extensive debris flows5,6 and future collapses could threaten areas that are now densely populated7. Preliminary geological mapping and remote-sensing data indicated that exposed alteration is contained in a dyke-controlled belt trending east-west that passes through the volcano's summit3-5,8. But here we present helicopter-borne electromagnetic and magnetic data, combined with detailed geological mapping, to show that appreciable thicknesses of mostly buried hydrothermally altered rock lie mainly in the upper west flank of Mount Rainier. We identify this as the likely source for future large debris flows. But as negligible amounts of highly altered rock lie in the volcano's core, this might impede collapse retrogression and so limit the volumes and inundation areas of future debris flows. Our results demonstrate that high-resolution geophysical and geological observations can yield unprecedented views of the three-dimensional distribution of altered rock.
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Bioinformatics: indispensable, yet hidden in plain sight?
Bartlett, Andrew; Penders, Bart; Lewis, Jamie
2017-06-21
Bioinformatics has multitudinous identities, organisational alignments and disciplinary links. This variety allows bioinformaticians and bioinformatic work to contribute to much (if not most) of life science research in profound ways. The multitude of bioinformatic work also translates into a multitude of credit-distribution arrangements, apparently dismissing that work. We report on the epistemic and social arrangements that characterise the relationship between bioinformatics and life science. We describe, in sociological terms, the character, power and future of bioinformatic work. The character of bioinformatic work is such that its cultural, institutional and technical structures allow for it to be black-boxed easily. The result is that bioinformatic expertise and contributions travel easily and quickly, yet remain largely uncredited. The power of bioinformatic work is shaped by its dependency on life science work, which combined with the black-boxed character of bioinformatic expertise further contributes to situating bioinformatics on the periphery of the life sciences. Finally, the imagined futures of bioinformatic work suggest that bioinformatics will become ever more indispensable without necessarily becoming more visible, forcing bioinformaticians into difficult professional and career choices. Bioinformatic expertise and labour is epistemically central but often institutionally peripheral. In part, this is a result of the ways in which the character, power distribution and potential futures of bioinformatics are constituted. However, alternative paths can be imagined.
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Gowthaman, Sivakumar; Nakashima, Kazunori; Kawasaki, Satoru
2018-01-01
Incorporating sustainable materials into geotechnical applications increases day by day due to the consideration of impacts on healthy geo-environment and future generations. The environmental issues associated with conventional synthetic materials such as cement, plastic-composites, steel and ashes necessitate alternative approaches in geotechnical engineering. Recently, natural fiber materials in place of synthetic material have gained momentum as an emulating soil-reinforcement technique in sustainable geotechnics. However, the natural fibers are innately different from such synthetic material whereas behavior of fiber-reinforced soil is influenced not only by physical-mechanical properties but also by biochemical properties. In the present review, the applicability of natural plant fibers as oriented distributed fiber-reinforced soil (ODFS) and randomly distributed fiber-reinforced soil (RDFS) are extensively discussed and emphasized the inspiration of RDFS based on the emerging trend. Review also attempts to explore the importance of biochemical composition of natural-fibers on the performance in subsoil reinforced conditions. The treatment methods which enhances the behavior and lifetime of fibers, are also presented. While outlining the current potential of fiber reinforcement technology, some key research gaps have been highlighted at their importance. Finally, the review briefly documents the future direction of the fiber reinforcement technology by associating bio-mediated technological line. PMID:29617285
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Huang, Shengzhi; Leng, Guoyong; Huang, Qiang; Xie, Yangyang; Liu, Saiyan; Meng, Erhao; Li, Pei
2017-07-19
Projection of future drought is often involved large uncertainties from climate models, emission scenarios as well as drought definitions. In this study, we investigate changes in future droughts in the conterminous United States based on 97 1/8 degree hydro-climate model projections. Instead of focusing on a specific drought type, we investigate changes in meteorological, agricultural, and hydrological drought as well as the concurrences. Agricultural and hydrological droughts are projected to become more frequent with increase in global mean temperature, while less meteorological drought is expected. Changes in drought intensity scale linearly with global temperature rises under RCP8.5 scenario, indicating the potential feasibility to derive future drought severity given certain global warming amount under this scenario. Changing pattern of concurrent droughts generally follows that of agricultural and hydrological droughts. Under the 1.5 °C warming target as advocated in recent Paris agreement, several hot spot regions experiencing highest droughts are identified. Extreme droughts show similar patterns but with much larger magnitude than the climatology. This study highlights the distinct response of droughts of various types to global warming and the asymmetric impact of global warming on drought distribution resulting in a much stronger influence on extreme drought than on mean drought.
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Distribution of high-temperature (>150 °C) geothermal resources in California
Sass, John H.; Priest, Susan S.
2002-01-01
California contains, by far, the greatest geothermal generating capacity in the United States, and with the possible exception of Alaska, the greatest potential for the development of additional resources. California has nearly 2/3 of the US geothermal electrical installed capacity of over 3,000 MW. Depending on assumptions regarding reservoir characteristics and future market conditions, additional resources of between 2,000 and 10,000 MWe might be developed (see e.g., Muffler, 1979).
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Current and future avoidable cost of smoking--estimates for Sweden 2007.
Bolin, Kristian; Borgman, Benny; Gip, Christina; Wilson, Koo
2011-11-01
To estimate current and future avoidable smoking-attributable costs in Sweden for the year 2007. Disease specific smoking-attributable proportions were calculated for Swedish smoking patterns and applied to estimate costs for smoking-related diseases based on data from public registers. Avoidable future effects of smoking were calculated employing a Markov simulation model. The estimated total cost in 2007 was USD 1.6 billion, or USD 181 per capita. Healthcare (direct) cost accounted for 30% of the total cost. The number of deaths was 97 per 100,000 inhabitants (79 in 2001); the number of years of potential life lost 1,227 per 100,000 inhabitants (1012 in 2001); and the number of years of potential productive life lost 226 (185 in 2001) per 100,000 inhabitants. Avoidable future lifetime costs, per 100,000 inhabitants, amounted to USD 19 million (healthcare), 14,000 years of potential life lost, corresponding to a present value of USD 158 million. Total avoidable cost of current smoking amounted to USD 16 billion. In spite of declining smoking-prevalence rates during the last 30 years, smoking-attributable deaths increased between 2001 and 2007. The number of life years lost per death decreased somewhat, indicating that the age distribution of those dying shifted further towards older age. Simulations indicate that smoking-cessation among young smokers yields considerable more benefits each year than smoking-cessation among older smokers. The health benefits that accrued in 2007, as a result of declining smoking prevalence since 1980, correspond to more than the total cost of smoking in that year. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
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Goovaerts, P.; Albuquerque, Teresa; Antunes, Margarida
2015-01-01
This paper describes a multivariate geostatistical methodology to delineate areas of potential interest for future sedimentary gold exploration, with an application to an abandoned sedimentary gold mining region in Portugal. The main challenge was the existence of only a dozen gold measurements confined to the grounds of the old gold mines, which precluded the application of traditional interpolation techniques, such as cokriging. The analysis could, however, capitalize on 376 stream sediment samples that were analyzed for twenty two elements. Gold (Au) was first predicted at all 376 locations using linear regression (R2=0.798) and four metals (Fe, As, Sn and W), which are known to be mostly associated with the local gold’s paragenesis. One hundred realizations of the spatial distribution of gold content were generated using sequential indicator simulation and a soft indicator coding of regression estimates, to supplement the hard indicator coding of gold measurements. Each simulated map then underwent a local cluster analysis to identify significant aggregates of low or high values. The one hundred classified maps were processed to derive the most likely classification of each simulated node and the associated probability of occurrence. Examining the distribution of the hot-spots and cold-spots reveals a clear enrichment in Au along the Erges River downstream from the old sedimentary mineralization. PMID:27777638
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Alstone, Peter; Potter, Jennifer; Piette, Mary Ann
Demand response (DR) is an important resource for keeping the electricity grid stable and efficient; deferring upgrades to generation, transmission, and distribution systems; and providing other customer economic benefits. This study estimates the potential size and cost of the available DR resource for California’s three investor-owned utilities (IOUs), as the California Public Utilities Commission (CPUC) evaluates how to enhance the role of DR in meeting California’s resource planning needs and operational requirements. As the state forges a clean energy future, the contributions of wind and solar electricity from centralized and distributed generation will fundamentally change the power grid’s operational dynamics.more » This transition requires careful planning to ensure sufficient capacity is available with the right characteristics – flexibility and fast response – to meet reliability needs. Illustrated is a snapshot of how net load (the difference between demand and intermittent renewables) is expected to shift. Increasing contributions from renewable generation introduces steeper ramps and a shift, into the evening, of the hours that drive capacity needs. These hours of peak capacity need are indicated by the black dots on the plots. Ultimately this study quantifies the ability and the cost of using DR resources to help meet the capacity need at these forecasted critical hours in the state.« less
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Pearce, Michael; Hee, Siew Wan; Madan, Jason; Posch, Martin; Day, Simon; Miller, Frank; Zohar, Sarah; Stallard, Nigel
2018-02-08
Most confirmatory randomised controlled clinical trials (RCTs) are designed with specified power, usually 80% or 90%, for a hypothesis test conducted at a given significance level, usually 2.5% for a one-sided test. Approval of the experimental treatment by regulatory agencies is then based on the result of such a significance test with other information to balance the risk of adverse events against the benefit of the treatment to future patients. In the setting of a rare disease, recruiting sufficient patients to achieve conventional error rates for clinically reasonable effect sizes may be infeasible, suggesting that the decision-making process should reflect the size of the target population. We considered the use of a decision-theoretic value of information (VOI) method to obtain the optimal sample size and significance level for confirmatory RCTs in a range of settings. We assume the decision maker represents society. For simplicity we assume the primary endpoint to be normally distributed with unknown mean following some normal prior distribution representing information on the anticipated effectiveness of the therapy available before the trial. The method is illustrated by an application in an RCT in haemophilia A. We explicitly specify the utility in terms of improvement in primary outcome and compare this with the costs of treating patients, both financial and in terms of potential harm, during the trial and in the future. The optimal sample size for the clinical trial decreases as the size of the population decreases. For non-zero cost of treating future patients, either monetary or in terms of potential harmful effects, stronger evidence is required for approval as the population size increases, though this is not the case if the costs of treating future patients are ignored. Decision-theoretic VOI methods offer a flexible approach with both type I error rate and power (or equivalently trial sample size) depending on the size of the future population for whom the treatment under investigation is intended. This might be particularly suitable for small populations when there is considerable information about the patient population.
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Arabasz, W.J.; Nava, S.J.; McCarter, M.K.; Pankow, K.L.; Pechmann, J.C.; Ake, J.; McGarr, A.
2005-01-01
We describe a multipart study to quantify the potential ground-shaking hazard to Joes Valley Dam, a 58-m-high earthfill dam, posed by mining-induced seismicity (MIS) from future underground coal mining, which could approach as close as ???1 km to the dam. To characterize future MIS close to the dam, we studied MIS located ???3-7 km from the dam at the Trail Mountain coal mine. A 12-station local seismic network (11 stations above ground, one below, combining eight triaxial accelerometers and varied velocity sensors) was operated in the Trail Mountain area from late 2000 through mid-2001 for the dual purpose of (1) continuously monitoring and locating MIS associated with longwall mining at a depth of 0.5-0.6 km and (2) recording high-quality data to develop ground-motion prediction equations for the shallow MIS. (Ground-motion attenuation relationships and moment-tensor results are reported in companion articles.) Utilizing a data set of 1913 earthquakes (M ??? 2.2), we describe space-time-magnitude distributions of the observed MIS and source-mechanism information. The MIS was highly correlated with mining activity both in space and time. Most of the better-located events have depths constrained within ??0.6 km of mine level. For the preponderance (98%) of the 1913 located events, only dilatational P-wave first motions were observed, consistent with other evidence for implosive or collapse-type mechanisms associated with coal mining in this region. We assess a probable maximum magnitude of M 3.9 (84th percentile of a cumulative distribution) for potential MIS close to Joes Valley Dam based on both the worldwide and regional record of coal-mining-related MIS and the local geology and future mining scenarios.
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Large Scale Relationship between Aquatic Insect Traits and Climate.
Bhowmik, Avit Kumar; Schäfer, Ralf B
2015-01-01
Climate is the predominant environmental driver of freshwater assemblage pattern on large spatial scales, and traits of freshwater organisms have shown considerable potential to identify impacts of climate change. Although several studies suggest traits that may indicate vulnerability to climate change, the empirical relationship between freshwater assemblage trait composition and climate has been rarely examined on large scales. We compared the responses of the assumed climate-associated traits from six grouping features to 35 bioclimatic indices (~18 km resolution) for five insect orders (Diptera, Ephemeroptera, Odonata, Plecoptera and Trichoptera), evaluated their potential for changing distribution pattern under future climate change and identified the most influential bioclimatic indices. The data comprised 782 species and 395 genera sampled in 4,752 stream sites during 2006 and 2007 in Germany (~357,000 km² spatial extent). We quantified the variability and spatial autocorrelation in the traits and orders that are associated with the combined and individual bioclimatic indices. Traits of temperature preference grouping feature that are the products of several other underlying climate-associated traits, and the insect order Ephemeroptera exhibited the strongest response to the bioclimatic indices as well as the highest potential for changing distribution pattern. Regarding individual traits, insects in general and ephemeropterans preferring very cold temperature showed the highest response, and the insects preferring cold and trichopterans preferring moderate temperature showed the highest potential for changing distribution. We showed that the seasonal radiation and moisture are the most influential bioclimatic aspects, and thus changes in these aspects may affect the most responsive traits and orders and drive a change in their spatial distribution pattern. Our findings support the development of trait-based metrics to predict and detect climate-related changes of freshwater assemblages.
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Rooftop solar photovoltaic potential in cities: how scalable are assessment approaches?
NASA Astrophysics Data System (ADS)
Castellanos, Sergio; Sunter, Deborah A.; Kammen, Daniel M.
2017-12-01
Distributed photovoltaics (PV) have played a critical role in the deployment of solar energy, currently making up roughly half of the global PV installed capacity. However, there remains significant unused economically beneficial potential. Estimates of the total technical potential for rooftop PV systems in the United States calculate a generation comparable to approximately 40% of the 2016 total national electric-sector sales. To best take advantage of the rooftop PV potential, effective analytic tools that support deployment strategies and aggressive local, state, and national policies to reduce the soft cost of solar energy are vital. A key step is the low-cost automation of data analysis and business case presentation for structure-integrated solar energy. In this paper, the scalability and resolution of various methods to assess the urban rooftop PV potential are compared, concluding with suggestions for future work in bridging methodologies to better assist policy makers.
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Olive cultivars adaptability in Southern Italy in present and future climate
NASA Astrophysics Data System (ADS)
Riccardi, M.; Alfieri, S.; Bonfante, A.; Basile, A.; Di Tommasi, P.; Menenti, M.; De Lorenzi, F.
2012-04-01
The intra-specific biodiversity of agricultural crops is very significant and likely to provide the single major opportunity to cope with the effects of the changing climate on agricultural ecosystems. Assessment of adaptive capacity must rely on quantitative descriptions of plant responses to environmental factors (e.g. soil water availability, temperature). Moreover climate scenario needs to be downscaled to the spatial scale relevant to crop and farm management. Distributed models of crop response to environmental forcing might be used for this purpose, but severely constrained by the very scarce knowledge on variety-specific values of model parameters, thus limiting the potential exploitation of intra-specific biodiversity towards adaptation. We have developed an approach towards this objective that relies on two complementary elements: a)a distributed model of the soil plant atmosphere system to downscale climate scenarios to landscape units, where generic model parameters for each species are used; b)a data base on climatic requirements of as many varieties as feasible for each species relevant to the agricultural production system of a given region. By means of this approach, the adaptability of some olive cultivars was evaluated in a composite (hills and plains) area of Southern Italy (Valle Telesina, Campania Region, about 20.000 ha). The yearly average temperature is 22.5 °C and rainfall ranges between 600 and 900 mm. Two different climate scenarios were considered: current climate (1961-1990) and future climate (2021-2050). Future climate scenarios at low spatial resolution were generated with general circulation models (AOGCM) and down-scaled by means of a statistical model (Tomozeiu et al., 2007). The climate was represented by daily observations of minimum, maximum temperature and precipitation on a regular grid with a spatial resolution of 35 km; 50 realizations were used for future climate. The soil water regime of 45 soil units was described for the two climate scenarios by using an hydrological distributed model (SWAP). For 11 olive cultivars, the yield response function to soil water regime was determined through the re-analysis of experimental data (unpublished or derived from scientific literature). According to these responses, cultivar-specific threshold values of soil water (or evapotranspiration) deficit were defined. The soil water regime calculated by the distributed model was compared with the threshold values to identify cultivars compatible with present and expected climates. The operation is repeated for a set of realizations of each climate scenario. This analysis is performed in a distributed manner, i.e. using the time series for each model grid to assess possible variations in the extent and spatial distribution of cultivated area of olive cultivars. In the study area future climate scenarios predict an increase of monthly minimum and maximum air temperature of about 2°C during the summer (June, July and August) and a reduction of rainfall in autumn. Spatial pattern of cultivars distribution, according their threshold values and soil water regime, was determined in the present and future climate scenarios, thus assessing variations in cultivars adaptability to future climate with respect to the present. Key words: climate change, biodiversity, water availability, yield response. The work was carried out within the Italian national project AGROSCENARI funded by the Ministry for Agricultural, Food and Forest Policies (MIPAAF, D.M. 8608/7303/2008).
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Architected squirt-flow materials for energy dissipation
NASA Astrophysics Data System (ADS)
Cohen, Tal; Kurzeja, Patrick; Bertoldi, Katia
2017-12-01
In the present study we explore material architectures that lead to enhanced dissipation properties by taking advantage of squirt-flow - a local flow mechanism triggered by heterogeneities at the pore level. While squirt-flow is a known dominant source of dissipation and seismic attenuation in fluid saturated geological materials, we study its untapped potential to be incorporated in highly deformable elastic materials with embedded fluid-filled cavities for future engineering applications. An analytical investigation, that isolates the squirt-flow mechanism from other potential dissipation mechanisms and considers an idealized setting, predicts high theoretical levels of dissipation achievable by squirt-flow and establishes a set of guidelines for optimal dissipation design. Particular architectures are then investigated via numerical simulations showing that a careful design of the internal voids can lead to an increase of dissipation levels by an order of magnitude, compared with equivalent homogeneous void distributions. Therefore, we suggest squirt-flow as a promising mechanism to be incorporated in future architected materials to effectively and reversibly dissipate energy.
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Hutchins, David A.; Walworth, Nathan G.; Webb, Eric A.; Saito, Mak A.; Moran, Dawn; McIlvin, Matthew R.; Gale, Jasmine; Fu, Fei-Xue
2015-01-01
Nitrogen fixation rates of the globally distributed, biogeochemically important marine cyanobacterium Trichodesmium increase under high carbon dioxide (CO2) levels in short-term studies due to physiological plasticity. However, its long-term adaptive responses to ongoing anthropogenic CO2 increases are unknown. Here we show that experimental evolution under extended selection at projected future elevated CO2 levels results in irreversible, large increases in nitrogen fixation and growth rates, even after being moved back to lower present day CO2 levels for hundreds of generations. This represents an unprecedented microbial evolutionary response, as reproductive fitness increases acquired in the selection environment are maintained after returning to the ancestral environment. Constitutive rate increases are accompanied by irreversible shifts in diel nitrogen fixation patterns, and increased activity of a potentially regulatory DNA methyltransferase enzyme. High CO2-selected cell lines also exhibit increased phosphorus-limited growth rates, suggesting a potential advantage for this keystone organism in a more nutrient-limited, acidified future ocean. PMID:26327191
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NASA Astrophysics Data System (ADS)
Hutchins, David A.; Walworth, Nathan G.; Webb, Eric A.; Saito, Mak A.; Moran, Dawn; McIlvin, Matthew R.; Gale, Jasmine; Fu, Fei-Xue
2015-09-01
Nitrogen fixation rates of the globally distributed, biogeochemically important marine cyanobacterium Trichodesmium increase under high carbon dioxide (CO2) levels in short-term studies due to physiological plasticity. However, its long-term adaptive responses to ongoing anthropogenic CO2 increases are unknown. Here we show that experimental evolution under extended selection at projected future elevated CO2 levels results in irreversible, large increases in nitrogen fixation and growth rates, even after being moved back to lower present day CO2 levels for hundreds of generations. This represents an unprecedented microbial evolutionary response, as reproductive fitness increases acquired in the selection environment are maintained after returning to the ancestral environment. Constitutive rate increases are accompanied by irreversible shifts in diel nitrogen fixation patterns, and increased activity of a potentially regulatory DNA methyltransferase enzyme. High CO2-selected cell lines also exhibit increased phosphorus-limited growth rates, suggesting a potential advantage for this keystone organism in a more nutrient-limited, acidified future ocean.
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NASA Technical Reports Server (NTRS)
Allison, Sidney G.; Prosser, William H.; Hare, David A.; Moore, Thomas C.; Kenner, Winfred S.
2007-01-01
This paper outlines cryogenic Y-joint testing at Langley Research Center (LaRC) to validate the performance of optical fiber Bragg grating strain sensors for measuring strain at liquid helium temperature (-240 C). This testing also verified survivability of fiber sensors after experiencing 10 thermal cool-down, warm-up cycles and 400 limit load cycles. Graphite composite skins bonded to a honeycomb substrate in a sandwich configuration comprised the Y-joint specimens. To enable SHM of composite cryotanks for consideration to future spacecraft, a light-weight, durable monitoring technology is needed. The fiber optic distributed Bragg grating strain sensing system developed at LaRC is a viable substitute for conventional strain gauges which are not practical for SHM. This distributed sensing technology uses an Optical Frequency Domain Reflectometer (OFDR). This measurement approach has the advantage that it can measure hundreds of Bragg grating sensors per fiber and the sensors are all written at one frequency, greatly simplifying fiber manufacturing. Fiber optic strain measurements compared well to conventional strain gauge measurements obtained during these tests. These results demonstrated a high potential for a successful implementation of a SHM system incorporating LaRC's fiber optic sensing system on the composite cryotank and other future cryogenic applications.
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Carmona-Castro, O; Moo-Llanes, D A; Ramsey, J M
2018-03-01
Climate change can influence the geographical range of the ecological niche of pathogens by altering biotic interactions with vectors and reservoirs. The distributions of 20 epidemiologically important triatomine species in North America were modelled, comparing the genetic algorithm for rule-set prediction (GARP) and maximum entropy (MaxEnt), with or without topographical variables. Potential shifts in transmission niche for Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) (Chagas, 1909) were analysed for 2050 and 2070 in Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. There were no significant quantitative range differences between the GARP and MaxEnt models, but GARP models best represented known distributions for most species [partial-receiver operating characteristic (ROC) > 1]; elevation was an important variable contributing to the ecological niche model (ENM). There was little difference between niche breadth projections for RCP 4.5 and RCP 8.5; the majority of species shifted significantly in both periods. Those species with the greatest current distribution range are expected to have the greatest shifts. Positional changes in the centroid, although reduced for most species, were associated with latitude. A significant increase or decrease in mean niche elevation is expected principally for Neotropical 1 species. The impact of climate change will be specific to each species, its biogeographical region and its latitude. North American triatomines with the greatest current distribution ranges (Nearctic 2 and Nearctic/Neotropical) will have the greatest future distribution shifts. Significant shifts (increases or decreases) in mean elevation over time are projected principally for the Neotropical species with the broadest current distributions. Changes in the vector exposure threat to the human population were significant for both future periods, with a 1.48% increase for urban populations and a 1.76% increase for rural populations in 2050. © 2017 The Royal Entomological Society.
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Mechanistic species distribution modelling as a link between physiology and conservation.
Evans, Tyler G; Diamond, Sarah E; Kelly, Morgan W
2015-01-01
Climate change conservation planning relies heavily on correlative species distribution models that estimate future areas of occupancy based on environmental conditions encountered in present-day ranges. The approach benefits from rapid assessment of vulnerability over a large number of organisms, but can have poor predictive power when transposed to novel environments and reveals little in the way of causal mechanisms that define changes in species distribution or abundance. Having conservation planning rely largely on this single approach also increases the risk of policy failure. Mechanistic models that are parameterized with physiological information are expected to be more robust when extrapolating distributions to future environmental conditions and can identify physiological processes that set range boundaries. Implementation of mechanistic species distribution models requires knowledge of how environmental change influences physiological performance, and because this information is currently restricted to a comparatively small number of well-studied organisms, use of mechanistic modelling in the context of climate change conservation is limited. In this review, we propose that the need to develop mechanistic models that incorporate physiological data presents an opportunity for physiologists to contribute more directly to climate change conservation and advance the field of conservation physiology. We begin by describing the prevalence of species distribution modelling in climate change conservation, highlighting the benefits and drawbacks of both mechanistic and correlative approaches. Next, we emphasize the need to expand mechanistic models and discuss potential metrics of physiological performance suitable for integration into mechanistic models. We conclude by summarizing other factors, such as the need to consider demography, limiting broader application of mechanistic models in climate change conservation. Ideally, modellers, physiologists and conservation practitioners would work collaboratively to build models, interpret results and consider conservation management options, and articulating this need here may help to stimulate collaboration.
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NASA Astrophysics Data System (ADS)
de Patoul, J.; Foullon, C.; Riley, P.
2015-12-01
Knowledge of the electron density distribution in the solar corona put constraints on the magnetic field configurations for coronal modeling, and on initial conditions for solar wind modeling. We work with polarized SOHO/LASCO-C2 images from the last two recent minima of solar activity (1996-1997 and 2008-2010), devoid of coronal mass ejections. We derive the 4D electron density distributions in the corona by applying a newly developed time-dependent tomographic reconstruction method. First we compare the density distributions obtained from tomography with magnetohydrodynamic (MHD) solutions. The tomography provides more accurate distributions of electron densities in the polar regions, and we find that the observed density varies with the solar cycle in both polar and equatorial regions. Second, we find that the highest-density structures do not always correspond to the predicted large-scale heliospheric current sheet or its helmet streamer but can follow the locations of pseudo-streamers. We conclude that tomography offers reliable density distribution in the corona, reproducing the slow time evolution of coronal structures, without prior knowledge of the coronal magnetic field over a full rotation. Finally, we suggest that the highest-density structures show a differential rotation well above the surface depending on how it is magnetically connected to the surface. Such valuable information on the rotation of large-scale structures could help to connect the sources of the solar wind to their in-situ counterparts in future missions such as Solar Orbiter and Solar Probe Plus. This research combined with the MHD coronal modeling efforts has the potential to increase the reliability for future space weather forecasting.
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Is Switzerland Suitable for the Invasion of Aedes albopictus?
Neteler, Markus; Metz, Markus; Rocchini, Duccio; Rizzoli, Annapaola; Flacio, Eleonora; Engeler, Luca; Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro
2013-01-01
Background Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. Methodology/Principal Findings We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020–2049 and 2045–2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchâtel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020–2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045–2074, when Ae. albopictus may invade large new areas. Conclusions/Significance Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European countries suggest that the tiger mosquito will colonize new areas in Switzerland in the near future. PMID:24349190
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Tougas-Tellier, Marie-Andrée; Morin, Jean; Hatin, Daniel; Lavoie, Claude
2015-01-01
Climate change will likely affect flooding regimes, which have a large influence on the functioning of freshwater riparian wetlands. Low water levels predicted for several fluvial systems make wetlands especially vulnerable to the spread of invaders, such as the common reed (Phragmites australis), one of the most invasive species in North America. We developed a model to map the distribution of potential germination grounds of the common reed in freshwater wetlands of the St. Lawrence River (Québec, Canada) under current climate conditions and used this model to predict their future distribution under two climate change scenarios simulated for 2050. We gathered historical and recent (remote sensing) data on the distribution of common reed stands for model calibration and validation purposes, then determined the parameters controlling the species establishment by seed. A two-dimensional model and the identified parameters were used to simulate the current (2010) and future (2050) distribution of germination grounds. Common reed stands are not widespread along the St. Lawrence River (212 ha), but our model suggests that current climate conditions are already conducive to considerable further expansion (>16,000 ha). Climate change may also exacerbate the expansion, particularly if river water levels drop, which will expose large bare areas propitious to seed germination. This phenomenon may be particularly important in one sector of the river, where existing common reed stands could increase their areas by a factor of 100, potentially creating the most extensive reedbed complex in North America. After colonizing salt and brackishwater marshes, the common reed could considerably expand into the freshwater marshes of North America which cover several million hectares. The effects of common reed expansion on biodiversity are difficult to predict, but likely to be highly deleterious given the competitiveness of the invader and the biological richness of freshwater wetlands. PMID:26380675
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Is Switzerland suitable for the invasion of Aedes albopictus [corrected]?
Neteler, Markus; Metz, Markus; Rocchini, Duccio; Rizzoli, Annapaola; Flacio, Eleonora; Engeler, Luca; Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro
2013-01-01
Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020-2049 and 2045-2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchâtel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020-2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045-2074, when Ae. albopictus may invade large new areas. Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European countries suggest that the tiger mosquito will colonize new areas in Switzerland in the near future.
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Present and Future of Dengue Fever in Nepal: Mapping Climatic Suitability by Ecological Niche Model
Cao, Chunxiang; Xu, Min; Pandit, Shreejana
2018-01-01
Both the number of cases of dengue fever and the areas of outbreaks within Nepal have increased significantly in recent years. Further expansion and range shift is expected in the future due to global climate change and other associated factors. However, due to limited spatially-explicit research in Nepal, there is poor understanding about the present spatial distribution patterns of dengue risk areas and the potential range shift due to future climate change. In this context, it is crucial to assess and map dengue fever risk areas in Nepal. Here, we used reported dengue cases and a set of bioclimatic variables on the MaxEnt ecological niche modeling approach to model the climatic niche and map present and future (2050s and 2070s) climatically suitable areas under different representative concentration pathways (RCP2.6, RCP6.0 and RCP8.5). Simulation-based estimates suggest that climatically suitable areas for dengue fever are presently distributed throughout the lowland Tarai from east to west and in river valleys at lower elevations. Under the different climate change scenarios, these areas will be slightly shifted towards higher elevation with varied magnitude and spatial patterns. Population exposed to climatically suitable areas of dengue fever in Nepal is anticipated to further increase in both 2050s and 2070s on all the assumed emission scenarios. These findings could be instrumental to plan and execute the strategic interventions for controlling dengue fever in Nepal. PMID:29360797
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Comparing Past and Future Elevational vs. Latitudinal Migrations in Mountains of the Western U.S
NASA Astrophysics Data System (ADS)
Cole, K. L.; Ironside, K.; Cobb, N.
2009-12-01
During the early Holocene, plant species of the western United States responded to the warming post-glacial temperatures by migrating to higher elevations and to more northerly latitudes. Models of species response to warmer climates assume similar processes will occur in the future but the rates and extent of these future migrations are unknown. Hypothetically, the rates of elevational and latitudinal migrations should differ depending upon the importance of spatial distance in determining the resulting migration rate. The diverse topography of the western United States presents an ideal laboratory for comparing these past elevational vs. latitudinal species movements. Abundant fossil records allow comparisons between these rates following rapidly warming periods in the past such as occurred in the early Holocene. At that time, species often equilibrated to the new temperature regime rapidly where they were only required to migrate a short distance uphill. But the same species required many thousands of years to subsequently approach their northern latitudinal boundaries. Further, the upper limits and lower limits for a species often did not move synchronously, yielding additional information on the dynamics of response to rapid warming for that particular species. We calibrated the available temperature space for several dominant forest tree species of the mountains of the interior western U.S. and then calculated their early Holocene rates of migration relative to geographic space. Next we were able to compare these estimations to the observations of each species recent historical autecological response to disturbances. For many species their paleoecological rates of change were consistent with observations of their dynamics over the last century. A few species, such as the wind dispersed Populus tremuloides, re-populate disturbed areas so rapidly that they have no discernable migration delay. Other species, such as Pinus ponderosa, can expand rapidly at a rate approximating 250 to 500 m/year. But even at such a rapid rate, they would only be able to expand a total of 45 km by the end of this century. And, because of their maturation time, this could constitute only three generations. Lastly, many species of interior semi-arid regions, such as Pseudotsuga menziesii and Pinus edulis, expand at rates of less than 100 m/yr. Finally, we applied calculated migration rates to modeled areas of future potential climate for each species. We generated these areas of future potential distribution using a selection of AR4 GCMs that were applied to species-specific climate models developed from late Twentieth Century correlations between climate and species ranges. Our results demonstrate that the incorporation of these migration rates greatly change the distributions that could be expected over the next 500 years. The effect of such migration rates have not been considered in models of future carbon balance, yet their history suggests that their importance may outweigh many other variables. Models incorporating migration should be even more important in the projection of future distributions of boreal species across expansive Arctic regions.
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Byers, James E; McDowell, William G; Dodd, Shelley R; Haynie, Rebecca S; Pintor, Lauren M; Wilde, Susan B
2013-01-01
Predicting the potential range of invasive species is essential for risk assessment, monitoring, and management, and it can also inform us about a species' overall potential invasiveness. However, modeling the distribution of invasive species that have not reached their equilibrium distribution can be problematic for many predictive approaches. We apply the modeling approach of maximum entropy (MaxEnt) that is effective with incomplete, presence-only datasets to predict the distribution of the invasive island apple snail, Pomacea insularum. This freshwater snail is native to South America and has been spreading in the USA over the last decade from its initial introductions in Texas and Florida. It has now been documented throughout eight southeastern states. The snail's extensive consumption of aquatic vegetation and ability to accumulate and transmit algal toxins through the food web heighten concerns about its spread. Our model shows that under current climate conditions the snail should remain mostly confined to the coastal plain of the southeastern USA where it is limited by minimum temperature in the coldest month and precipitation in the warmest quarter. Furthermore, low pH waters (pH <5.5) are detrimental to the snail's survival and persistence. Of particular note are low-pH blackwater swamps, especially Okefenokee Swamp in southern Georgia (with a pH below 4 in many areas), which are predicted to preclude the snail's establishment even though many of these areas are well matched climatically. Our results elucidate the factors that affect the regional distribution of P. insularum, while simultaneously presenting a spatial basis for the prediction of its future spread. Furthermore, the model for this species exemplifies that combining climatic and habitat variables is a powerful way to model distributions of invasive species.
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NASA Astrophysics Data System (ADS)
Selakovic, S.; Cozzoli, F.; Leuven, J.; Van Braeckel, A.; Speybroeck, J.; Kleinhans, M. G.; Bouma, T.
2017-12-01
Interactions between organisms and landscape forming processes play an important role in evolution of coastal landscapes. In particular, biota has a strong potential to interact with important geomorphological processes such as sediment dynamics. Although many studies worked towards quantifying the impact of different species groups on sediment dynamics, information has been gathered on an ad hoc base. Depending on species' traits and distribution, functional groups of ecoengineering species may have differential effects on sediment deposition and erosion. We hypothesize that the spatial distributions of sediment-stabilizing and destabilizing species across the channel and along the whole salinity gradient of an estuary partly determine the planform shape and channel-shoal morphology of estuaries. To test this hypothesis, we analyze vegetation and macrobenthic data taking the Scheldt river-estuarine continuum as model ecosystem. We identify species traits with important effects on sediment dynamics and use them to form functional groups. By using linearized mixed modelling, we are able to accurately describe the distributions of the different functional groups. We observe a clear distinction of dominant ecosystem engineering functional groups and their potential effects on the sediment in the river-estuarine continuum. The first results of longitudinal cross section show the highest effects of stabilizing plant species in riverine and sediment bioturbators in weak polyhaline part of continuum. The distribution of functional groups in transverse cross sections shows dominant stabilizing effect in supratidal zone compared to dominant destabilizing effect in the lower intertidal zone. This analysis offers a new and more general conceptualization of distributions of sediment stabilizing and destabilizing functional groups and their potential impacts on sediment dynamics, shoal patterns, and planform shapes in river-estuarine continuum. We intend to test this in future modelling and experiments.
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Muscarella, Robert; Borchsenius, Finn
2017-01-01
Invasive allergenic plant species may have severe health-related impacts. In this study we aim to predict the effects of climate change on the distribution of three allergenic ragweed species (Ambrosia spp.) in Europe and discuss the potential associated health impact. We built species distribution models based on presence-only data for three ragweed species, using MAXENT software. Future climatic habitat suitability was modeled under two IPCC climate change scenarios (RCP 6.0 and RCP 8.5). We quantify the extent of the increase in ‘high allergy risk’ (HAR) areas, i.e., parts of Europe with climatic conditions corresponding to the highest quartile (25%) of present day habitat suitability for each of the three species. We estimate that by year 2100, the distribution range of all three ragweed species increases towards Northern and Eastern Europe under all climate scenarios. HAR areas will expand in Europe by 27–100%, depending on species and climate scenario. Novel HAR areas will occur mostly in Denmark, France, Germany, Russia and the Baltic countries, and overlap with densely populated cities such as Paris and St. Petersburg. We conclude that areas in Europe affected by severe ragweed associated allergy problems are likely to increase substantially by year 2100, affecting millions of people. To avoid this, management strategies must be developed that restrict ragweed dispersal and establishment of new populations. Precautionary efforts should limit the spread of ragweed seeds and reduce existing populations. Only by applying cross-countries management plans can managers mitigate future health risks and economical consequences of a ragweed expansion in Europe. PMID:28321366
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Modeling nonbreeding distributions of shorebirds and waterfowl in response to climate change
Reese, Gordon; Skagen, Susan K.
2017-01-01
To identify areas on the landscape that may contribute to a robust network of conservation areas, we modeled the probabilities of occurrence of several en route migratory shorebirds and wintering waterfowl in the southern Great Plains of North America, including responses to changing climate. We predominantly used data from the eBird citizen-science project to model probabilities of occurrence relative to land-use patterns, spatial distribution of wetlands, and climate. We projected models to potential future climate conditions using five representative general circulation models of the Coupled Model Intercomparison Project 5 (CMIP5). We used Random Forests to model probabilities of occurrence and compared the time periods 1981–2010 (hindcast) and 2041–2070 (forecast) in “model space.” Projected changes in shorebird probabilities of occurrence varied with species-specific general distribution pattern, migration distance, and spatial extent. Species using the western and northern portion of the study area exhibited the greatest likelihoods of decline, whereas species with more easterly occurrences, mostly long-distance migrants, had the greatest projected increases in probability of occurrence. At an ecoregional extent, differences in probabilities of shorebird occurrence ranged from −0.015 to 0.045 when averaged across climate models, with the largest increases occurring early in migration. Spatial shifts are predicted for several shorebird species. Probabilities of occurrence of wintering Mallards and Northern Pintail are predicted to increase by 0.046 and 0.061, respectively, with northward shifts projected for both species. When incorporated into partner land management decision tools, results at ecoregional extents can be used to identify wetland complexes with the greatest potential to support birds in the nonbreeding season under a wide range of future climate scenarios.
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Valiakos, George; Papaspyropoulos, Konstantinos; Giannakopoulos, Alexios; Birtsas, Periklis; Tsiodras, Sotirios; Hutchings, Michael R; Spyrou, Vassiliki; Pervanidou, Danai; Athanasiou, Labrini V; Papadopoulos, Nikolaos; Tsokana, Constantina; Baka, Agoritsa; Manolakou, Katerina; Chatzopoulos, Dimitrios; Artois, Marc; Yon, Lisa; Hannant, Duncan; Petrovska, Liljana; Hadjichristodoulou, Christos; Billinis, Charalambos
2014-01-01
West Nile Virus (WNV) is the causative agent of a vector-borne, zoonotic disease with a worldwide distribution. Recent expansion and introduction of WNV into new areas, including southern Europe, has been associated with severe disease in humans and equids, and has increased concerns regarding the need to prevent and control future WNV outbreaks. Since 2010, 524 confirmed human cases of the disease have been reported in Greece with greater than 10% mortality. Infected mosquitoes, wild birds, equids, and chickens have been detected and associated with human disease. The aim of our study was to establish a monitoring system with wild birds and reported human cases data using Geographical Information System (GIS). Potential distribution of WNV was modelled by combining wild bird serological surveillance data with environmental factors (e.g. elevation, slope, land use, vegetation density, temperature, precipitation indices, and population density). Local factors including areas of low altitude and proximity to water were important predictors of appearance of both human and wild bird cases (Odds Ratio = 1,001 95%CI = 0,723-1,386). Using GIS analysis, the identified risk factors were applied across Greece identifying the northern part of Greece (Macedonia, Thrace) western Greece and a number of Greek islands as being at highest risk of future outbreaks. The results of the analysis were evaluated and confirmed using the 161 reported human cases of the 2012 outbreak predicting correctly (Odds = 130/31 = 4,194 95%CI = 2,841-6,189) and more areas were identified for potential dispersion in the following years. Our approach verified that WNV risk can be modelled in a fast cost-effective way indicating high risk areas where prevention measures should be implemented in order to reduce the disease incidence.
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Sleeping sickness in Uganda: revisiting current and historical distributions.
Berrang-Ford, Lea; Odiit, Martin; Maiso, Faustin; Waltner-Toews, David; McDermott, John
2006-12-01
Sleeping sickness is a parasitic, vector-borne disease, carried by the tsetse fly and prevalent in sub-Saharan Africa. The disease continues to pose a public health burden in Uganda, which experienced a widespread outbreak in 1900-1920, and a more recent outbreak in 1976-1989. The disease continues to spread to uninfected districts. This paper compares the spatial distributions of sleeping in Uganda for the 1900-1920 outbreak period with current disease foci, and discusses information gaps and implications arising for future research, prevention and control. Population census records for 1911 and sleeping sickness records from Medical and Sanitary Reports of the Ugandan Protectorate for 1905-1936 were extracted from the Uganda Archives. Current sleeping sickness distribution data were provided by the Ministry of Health, Uganda. These were used to develop sleeping sickness distribution maps for comparison between the early 1900s and the early 2000s. The distribution of sleeping sickness from 1905-1920 shows notable differences compared to the current distribution of disease. In particular, archival cases were recorded in south-west and central Uganda, areas currently free of disease. The disease focus has moved from lakeshore Buganda (1905-1920) to the Busoga and south-east districts. Archival sleeping sickness distributions indicate the potential for a much wider area of disease risk than indicated by current disease foci. This is compounded by an absence of tsetse distribution data, continued political instability in north-central Uganda, continued spread of disease into new districts, and evidence of the role of livestock movements in spreading the parasite. These results support concerns as to the potential mergence of the two disease foci in the south-east and north-west of the country.
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Understanding Peripheral Bat Populations Using Maximum-Entropy Suitability Modeling
Barnhart, Paul R.; Gillam, Erin H.
2016-01-01
Individuals along the periphery of a species distribution regularly encounter more challenging environmental and climatic conditions than conspecifics near the center of the distribution. Due to these potential constraints, individuals in peripheral margins are expected to change their habitat and behavioral characteristics. Managers typically rely on species distribution maps when developing adequate management practices. However, these range maps are often too simplistic and do not provide adequate information as to what fine-scale biotic and abiotic factors are driving a species occurrence. In the last decade, habitat suitability modelling has become widely used as a substitute for simplistic distribution mapping which allows regional managers the ability to fine-tune management resources. The objectives of this study were to use maximum-entropy modeling to produce habitat suitability models for seven species that have a peripheral margin intersecting the state of North Dakota, according to current IUCN distributions, and determine the vegetative and climatic characteristics driving these models. Mistnetting resulted in the documentation of five species outside the IUCN distribution in North Dakota, indicating that current range maps for North Dakota, and potentially the northern Great Plains, are in need of update. Maximum-entropy modeling showed that temperature and not precipitation were the variables most important for model production. This fine-scale result highlights the importance of habitat suitability modelling as this information cannot be extracted from distribution maps. Our results provide baseline information needed for future research about how and why individuals residing in the peripheral margins of a species’ distribution may show marked differences in habitat use as a result of urban expansion, habitat loss, and climate change compared to more centralized populations. PMID:27935936
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Rodrigues, P M S; Silva, J O; Eisenlohr, P V; Schaefer, C E G R
2015-08-01
The aim of this study was to evaluate the ecological niche models (ENMs) for three specialist trees (Anadenanthera colubrina, Aspidosperma pyrifolium and Myracrodruon urundeuva) in seasonally dry tropical forests (SDTFs) in Brazil, considering present and future pessimist scenarios (2080) of climate change. These three species exhibit typical deciduousness and are widely distributed by SDTF in South America, being important in studies of the historical and evolutionary processes experienced by this ecosystem. The modeling of the potential geographic distribution of species was done by the method of maximum entropy (Maxent).We verified a general expansion of suitable areas for occurrence of the three species in future (c.a., 18%), although there was reduction of areas with high environmental suitability in Caatinga region. Precipitation of wettest quarter and temperature seasonality were the predictor variables that most contributed to our models. Climatic changes can provide more severe and longer dry season with increasing temperature and tree mortality in tropics. On this scenario, areas currently occupied by rainforest and savannas could become more suitable for occurrence of the SDTF specialist trees, whereas regions occupied by Caatinga could not support the future level of unsustainable (e.g., aridity). Long-term multidisciplinary studies are necessary to make reliable predictions of the plant's adaptation strategies and responses to climate changes in dry forest at community level. Based on the high deforestation rate, endemism and threat, public policies to minimize the effects of climate change on the biodiversity found within SDTFs must be undertaken rapidly.
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Vuorinen, Ilppo; Hänninen, Jari; Rajasilta, Marjut; Laine, Päivi; Eklund, Jan; Montesino-Pouzols, Federico; Corona, Francesco; Junker, Karin; Meier, H.E.Markus; Dippner, Joachim W.
2015-01-01
Substantial ecological changes occurred in the 1970s in the Northern Baltic during a temporary period of low salinity (S). This period was preceded by an episodic increase in the rainfall over the Baltic Sea watershed area. Several climate models, both global and regional, project an increase in the runoff of the Northern latitudes due to proceeding climate change. The aim of this study is to model, firstly, the effects on Baltic Sea salinity of increased runoff due to projected global change and, secondly, the effects of salinity change on the distribution of marine species. The results suggest a critical shift in the S range 5–7, which is a threshold for both freshwater and marine species distributions and diversity. We discuss several topics emphasizing future monitoring, modelling, and fisheries research. Environmental monitoring and modelling are investigated because the developing alternative ecosystems do not necessarily show the same relations to environment quality factors as the retiring ones. An important corollary is that the observed and modelled S changes considered together with species’ ranges indicate what may appear under a future climate. Consequences could include a shift in distribution areas of marine benthic foundation species and some 40–50 other species, affiliated to these. This change would extend over hundreds of kilometres, in the Baltic Sea and the adjacent North Sea areas. Potential cascading effects, in coastal ecology, fish ecology and fisheries would be extensive, and point out the necessity to develop further the “ecosystem approach in the environmental monitoring”. PMID:25737660
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Foreground effect on the J-factor estimation of ultra-faint dwarf spheroidal galaxies
NASA Astrophysics Data System (ADS)
Ichikawa, Koji; Horigome, Shun-ichi; Ishigaki, Miho N.; Matsumoto, Shigeki; Ibe, Masahiro; Sugai, Hajime; Hayashi, Kohei
2018-05-01
Dwarf spheroidal galaxies (dSphs) are promising targets for the gamma-ray dark matter (DM) search. In particular, DM annihilation signal is expected to be strong in some of the recently discovered nearby ultra-faint dSphs, which potentially give stringent constraints on the O(1) TeV WIMP DM. However, various non-negligible systematic uncertainties complicate the estimation of the astrophysical factors relevant for the DM search in these objects. Among them, the effects of foreground stars particularly attract attention because the contamination is unavoidable even for the future kinematical survey. In this article, we assess the effects of the foreground contamination on the astrophysical J-factor estimation by generating mock samples of stars in the four ultra-faint dSphs and using a model of future spectrographs. We investigate various data cuts to optimize the quality of the data and apply a likelihood analysis which takes member and foreground stellar distributions into account. We show that the foreground star contaminations in the signal region (the region of interest) and their statistical uncertainty can be estimated by interpolating the foreground star distribution in the control region where the foreground stars dominate the member stars. Such regions can be secured at future spectroscopic observations utilizing a multiple object spectrograph with a large field of view; e.g. the Prime Focus Spectrograph mounted on Subaru Telescope. The above estimation has several advantages: The data-driven estimation of the contamination makes the analysis of the astrophysical factor stable against the complicated foreground distribution. Besides, foreground contamination effect is considered in the likelihood analysis.
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Miller, Brian W.; Morisette, Jeffrey T.
2014-01-01
Developing resource management strategies in the face of climate change is complicated by the considerable uncertainty associated with projections of climate and its impacts and by the complex interactions between social and ecological variables. The broad, interconnected nature of this challenge has resulted in calls for analytical frameworks that integrate research tools and can support natural resource management decision making in the face of uncertainty and complex interactions. We respond to this call by first reviewing three methods that have proven useful for climate change research, but whose application and development have been largely isolated: species distribution modeling, scenario planning, and simulation modeling. Species distribution models provide data-driven estimates of the future distributions of species of interest, but they face several limitations and their output alone is not sufficient to guide complex decisions for how best to manage resources given social and economic considerations along with dynamic and uncertain future conditions. Researchers and managers are increasingly exploring potential futures of social-ecological systems through scenario planning, but this process often lacks quantitative response modeling and validation procedures. Simulation models are well placed to provide added rigor to scenario planning because of their ability to reproduce complex system dynamics, but the scenarios and management options explored in simulations are often not developed by stakeholders, and there is not a clear consensus on how to include climate model outputs. We see these strengths and weaknesses as complementarities and offer an analytical framework for integrating these three tools. We then describe the ways in which this framework can help shift climate change research from useful to usable.
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Campbell, John L.; Shinneman, Douglas
2017-01-01
IntroductionClimate change is expected to impose significant tension on the geographic distribution of tree species. Yet, tree species range shifts may be delayed by their long life spans, capacity to withstand long periods of physiological stress, and dispersal limitations. Wildfire could theoretically break this biological inertia by killing forest canopies and facilitating species redistribution under changing climate. We investigated the capacity of wildfire to modulate climate-induced tree redistribution across a montane landscape in the central Rocky Mountains under three climate scenarios (contemporary and two warmer future climates) and three wildfire scenarios (representing historical, suppressed, and future fire regimes).MethodsDistributions of four common tree species were projected over 90 years by pairing a climate niche model with a forest landscape simulation model that simulates species dispersal, establishment, and mortality under alternative disturbance regimes and climate scenarios.ResultsThree species (Douglas-fir, lodgepole pine, subalpine fir) declined in abundance over time, due to climate-driven contraction in area suitable for establishment, while one species (ponderosa pine) was unable to exploit climate-driven expansion of area suitable for establishment. Increased fire frequency accelerated declines in area occupied by Douglas-fir, lodgepole pine, and subalpine fir, and it maintained local abundance but not range expansion of ponderosa pine.ConclusionsWildfire may play a larger role in eliminating these conifer species along trailing edges of their distributions than facilitating establishment along leading edges, in part due to dispersal limitations and interspecific competition, and future populations may increasingly depend on persistence in locations unfavorable for their establishment.
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Data Sharing in DHT Based P2P Systems
NASA Astrophysics Data System (ADS)
Roncancio, Claudia; Del Pilar Villamil, María; Labbé, Cyril; Serrano-Alvarado, Patricia
The evolution of peer-to-peer (P2P) systems triggered the building of large scale distributed applications. The main application domain is data sharing across a very large number of highly autonomous participants. Building such data sharing systems is particularly challenging because of the “extreme” characteristics of P2P infrastructures: massive distribution, high churn rate, no global control, potentially untrusted participants... This article focuses on declarative querying support, query optimization and data privacy on a major class of P2P systems, that based on Distributed Hash Table (P2P DHT). The usual approaches and the algorithms used by classic distributed systems and databases for providing data privacy and querying services are not well suited to P2P DHT systems. A considerable amount of work was required to adapt them for the new challenges such systems present. This paper describes the most important solutions found. It also identifies important future research trends in data management in P2P DHT systems.
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Looking to the Future: Health Professions Education in Texas.
ERIC Educational Resources Information Center
Rettig, Richard
This report analyzes how the Texas higher education system will meet the needs of future health care professionals. The report examines: (1) medical education needs (physician supply, physician distribution, medical schools' responses to physician distribution, and distribution of medical schools and regional academic health centers); (2) national…
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Steven E. Smith; Ma.G. Mendoza; Gerardo Zuniga; Kandres Kalbrook; J.L. Hayes; D.N. Byrne
2013-01-01
Understanding the distribution of key biotic elements of forest ecosystems is essential in contemporary forest management and in planning to meet future management needs. Habitat distribution (niche) models based on known occurrences provide geographical structure for such management as the environmental factors change....
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Climatic water deficit, tree species ranges, and climate change in Yosemite National Park
Lutz, James A.; Van Wagtendonk, Jan W.; Franklin, Jerry F.
2010-01-01
Aim (1) To calculate annual potential evapotranspiration (PET), actual evapotranspiration (AET) and climatic water deficit (Deficit) with high spatial resolution; (2) to describe distributions for 17 tree species over a 2300-m elevation gradient in a 3000-km2 landscape relative to AET and Deficit; (3) to examine changes in AET and Deficit between past (c. 1700), present (1971–2000) and future (2020–49) climatological means derived from proxies, observations and projections; and (4) to infer how the magnitude of changing Deficit may contribute to changes in forest structure and composition.Location Yosemite National Park, California, USA.Methods We calculated the water balance within Yosemite National Park using a modified Thornthwaite-type method and correlated AET and Deficit with tree species distribution. We used input data sets with different spatial resolutions parameterized for variation in latitude, precipitation, temperature, soil water-holding capacity, slope and aspect. We used climate proxies and climate projections to model AET and Deficit for past and future climate. We compared the modelled future water balance in Yosemite with current species water-balance ranges in North America.Results We calculated species climatic envelopes over broad ranges of environmental gradients – a range of 310 mm for soil water-holding capacity, 48.3°C for mean monthly temperature (January minima to July maxima), and 918 mm yr−1 for annual precipitation. Tree species means were differentiated by AET and Deficit, and at higher levels of Deficit, species means were increasingly differentiated. Modelled Deficit for all species increased by a mean of 5% between past (c. 1700) and present (1971–2000). Projected increases in Deficit between present and future (2020–49) were 23% across all plots.Main conclusions Modelled changes in Deficit between past, present and future climate scenarios suggest that recent past changes in forest structure and composition may accelerate in the future, with species responding individualistically to further declines in water availability. Declining water availability may disproportionately affect Pinus monticola and Tsuga mertensiana. Fine-scale heterogeneity in soil water-holding capacity, aspect and slope implies that plant water balance may vary considerably within the grid cells of kilometre-scale climate models. Sub-grid-cell soil and topographical data can partially compensate for the lack of spatial heterogeneity in gridded climate data, potentially improving vegetation-change projections in mountainous landscapes with heterogeneous topography.
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Uncertainty in future projections of global and regional marine fisheries catches
NASA Astrophysics Data System (ADS)
Reygondeau, G.; Cheung, W. W. L.; Froelicher, T. L.; Stock, C. A.; Jones, M. C.; Sarmiento, J. L.
2016-02-01
Previous studies have projected the global redistribution of potential marine fisheries catches by mid-21st century under climate change, with increases in high latitude regions and pronounced decreases in tropical biomes. However, quantified confidence levels of such projections are not available, rendering it difficult to interpret the associated risk to society. This paper quantifies the confidence of changes in future fish production using a 30-member ensemble simulation of the Geophysical Fluid Dynamics Laboratory ESM2M (representing internal variability of oceanographic conditions), three structural variants of a mechanistic species distribution model (representing uncertainty in fisheries models and different greenhouse gas emission and fishing scenarios (representing scenario uncertainty). We project that total potential catches of 500 exploited fish and invertebrate stocks, that contribute most to regional fisheries catches and their variability, will likely decrease in the 21st century under a `business-as-usual' greenhouse gas emission scenario (RCP8.5). Fishing and it's management remains a main factor determining future fish stocks and their catches. Internal variability of projected ocean conditions, including temperature, oxygen level, pH, net primary production and sea ice contributes substantially to the uncertainty of potential catch projections. Regionally, climate-driven decreases in potential catches in tropical oceans and increases in the Arctic polar regions are projected with higher confidence than other regions, while the direction of changes in most mid-latitude (or temperate) regions is uncertain. Under a stringent greenhouse gas mitigation scenario (RCP 2.6), climate change impacts on potential catches may not emerge from their uncertainties. Overall, this study provides a foundation for quantifying risks of climate change impacts on marine fisheries globally and regionally, and how such risk may be altered by policy interventions.
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Interactions Between Land Use, Climate and Hydropower in Scotland
NASA Astrophysics Data System (ADS)
Sample, J.
2014-12-01
To promote the transition towards a low carbon economy, the Scottish Government has adopted ambitious energy targets, including generating all electricity from renewable sources by 2020. To achieve this, continued investment will be required across a range of sustainable technologies. Hydropower has a long history in Scotland and the present-day operational capacity of ~1.5 GW makes a substantial contribution to the national energy budget. In addition, there remains potential for ~500 MW of further development, mostly in the form of small to medium size run-of-river schemes. Climate change is expected to lead to an intensification of the global hydrological cycle, leading to changes in both the magnitude and seasonality of river flows. There may also be indirect effects, such as changing land use, enhanced evapotranspiration rates and an increased demand for irrigation, all of which could affect the water available for energy generation. Preliminary assessments of hydropower commonly use flow duration curves (FDCs) to estimate the power generation potential at proposed new sites. In this study, we use spatially distributed modelling to generate daily and monthly FDCs for a range of Scottish catchments using a variety of future land use and climate change scenarios. These are then used to assess Scotland's future hydropower potential under different flow regimes. The results are spatially variable and include large uncertainties, but some consistent patterns emerge. Many locations are predicted to experience enhanced seasonality, with lower power generation potential in the summer months and greater potential during the autumn and winter. Some sites may require infrastructural changes in order to continue operating at optimum efficiency. We discuss the implications and limitations of our results, and highlight design and adaptation options for maximising the resilience of hydropower installations under changing future flow patterns.
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Building a database for statistical characterization of ELMs on DIII-D
NASA Astrophysics Data System (ADS)
Fritch, B. J.; Marinoni, A.; Bortolon, A.
2017-10-01
Edge localized modes (ELMs) are bursty instabilities which occur in the edge region of H-mode plasmas and have the potential to damage in-vessel components of future fusion machines by exposing the divertor region to large energy and particle fluxes during each ELM event. While most ELM studies focus on average quantities (e.g. energy loss per ELM), this work investigates the statistical distributions of ELM characteristics, as a function of plasma parameters. A semi-automatic algorithm is being used to create a database documenting trigger times of the tens of thousands of ELMs for DIII-D discharges in scenarios relevant to ITER, thus allowing statistically significant analysis. Probability distributions of inter-ELM periods and energy losses will be determined and related to relevant plasma parameters such as density, stored energy, and current in order to constrain models and improve estimates of the expected inter-ELM periods and sizes, both of which must be controlled in future reactors. Work supported in part by US DoE under the Science Undergraduate Laboratory Internships (SULI) program, DE-FC02-04ER54698 and DE-FG02- 94ER54235.
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Li, Tuoyu; Ma, Zongwen; Xu, Xuegong
2017-01-01
The article examines the detailed spatial and temporal distributions of coastal reclamation in the northwest coast of Bohai Bay experiencing rapid coastal reclamation in China from 1974 to 2010 in annual intervals. Moreover, soil elements properties and spatial distribution in reclaimed area and inform the future coastal ecosystems management was also analyzed. The results shows that 910.7 km2 of coastal wetlands have been reclaimed and conversed to industrial land during the past 36 years. It covers intertidal beach, shallow sea and island with a percentage of 76.0%, 23.5% and 0.5%, respectively. The average concentration of Mn is 686.91mg/kg and the order of concentration of heavy metal are Cr>Zn>As>Ni>Cu>Pb>Cd>Hg. We used the "space for time substitution" method to test the soil properties changes after reclamation. The potential ecological risk of heavy metal is in low level and the risk of Cd and As is relatively higher. The ecosystem-based coastal protection and management are urgent to support sustainable coastal ecosystems in Bohai bay in the future. PMID:28422982
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Aedes Mosquitoes and Aedes-Borne Arboviruses in Africa: Current and Future Threats
Weetman, David; Shearer, Freya M.; Coulibaly, Mamadou
2018-01-01
The Zika crisis drew attention to the long-overlooked problem of arboviruses transmitted by Aedes mosquitoes in Africa. Yellow fever, dengue, chikungunya and Zika are poorly controlled in Africa and often go unrecognized. However, to combat these diseases, both in Africa and worldwide, it is crucial that this situation changes. Here, we review available data on the distribution of each disease in Africa, their Aedes vectors, transmission potential, and challenges and opportunities for Aedes control. Data on disease and vector ranges are sparse, and consequently maps of risk are uncertain. Issues such as genetic and ecological diversity, and opportunities for integration with malaria control, are primarily African; others such as ever-increasing urbanization, insecticide resistance and lack of evidence for most control-interventions reflect problems throughout the tropics. We identify key knowledge gaps and future research areas, and in particular, highlight the need to improve knowledge of the distributions of disease and major vectors, insecticide resistance, and to develop specific plans and capacity for arboviral disease surveillance, prevention and outbreak responses. PMID:29382107
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Zhu, Gaoru; Xie, Zhenglei; Li, Tuoyu; Ma, Zongwen; Xu, Xuegong
2017-01-01
The article examines the detailed spatial and temporal distributions of coastal reclamation in the northwest coast of Bohai Bay experiencing rapid coastal reclamation in China from 1974 to 2010 in annual intervals. Moreover, soil elements properties and spatial distribution in reclaimed area and inform the future coastal ecosystems management was also analyzed. The results shows that 910.7 km2 of coastal wetlands have been reclaimed and conversed to industrial land during the past 36 years. It covers intertidal beach, shallow sea and island with a percentage of 76.0%, 23.5% and 0.5%, respectively. The average concentration of Mn is 686.91mg/kg and the order of concentration of heavy metal are Cr>Zn>As>Ni>Cu>Pb>Cd>Hg. We used the "space for time substitution" method to test the soil properties changes after reclamation. The potential ecological risk of heavy metal is in low level and the risk of Cd and As is relatively higher. The ecosystem-based coastal protection and management are urgent to support sustainable coastal ecosystems in Bohai bay in the future.
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Finder, Stuart G; Bliton, Mark J; Gill, Chandler E; Davis, Thomas L; Konrad, Peter E; Charles, P David
2012-01-01
Central to ethically justified clinical trial design is the need for an informed consent process responsive to how potential subjects actually comprehend study participation, especially study goals, risks, and potential benefits. This will be particularly challenging when studying deep brain stimulation and whether it impedes symptom progression in Parkinson's disease, since potential subjects will be Parkinson's patients for whom deep brain stimulation will likely have therapeutic value in the future as their disease progresses. As part of an expanded informed consent process for a pilot Phase I study of deep brain stimulation in early stage Parkinson's disease, an ethics questionnaire composed of 13 open-ended questions was distributed to potential subjects. The questionnaire was designed to guide potential subjects in thinking about their potential participation. While the purpose of the study (safety and tolerability) was extensively presented during the informed consent process, in returned responses 70 percent focused on effectiveness and 91 percent included personal benefit as poten- tial benefit from enrolling. However, 91 percent also indicated helping other Parkinson's patients as motivation when considering whether or not to enroll. This combination of responses highlights two issues to which investigators need to pay close attention in future trial designs: (1) how, and in what ways, informed consent processes reinforce potential subjects' preconceived understandings of benefit, and (2) that potential subjects see themselves as part of a community of Parkinson's sufferers with responsibilities extending beyond self-interest. More importantly, it invites speculation that a different paradigm for informed consent may be needed.
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Niches, models, and climate change: Assessing the assumptions and uncertainties
Wiens, John A.; Stralberg, Diana; Jongsomjit, Dennis; Howell, Christine A.; Snyder, Mark A.
2009-01-01
As the rate and magnitude of climate change accelerate, understanding the consequences becomes increasingly important. Species distribution models (SDMs) based on current ecological niche constraints are used to project future species distributions. These models contain assumptions that add to the uncertainty in model projections stemming from the structure of the models, the algorithms used to translate niche associations into distributional probabilities, the quality and quantity of data, and mismatches between the scales of modeling and data. We illustrate the application of SDMs using two climate models and two distributional algorithms, together with information on distributional shifts in vegetation types, to project fine-scale future distributions of 60 California landbird species. Most species are projected to decrease in distribution by 2070. Changes in total species richness vary over the state, with large losses of species in some “hotspots” of vulnerability. Differences in distributional shifts among species will change species co-occurrences, creating spatial variation in similarities between current and future assemblages. We use these analyses to consider how assumptions can be addressed and uncertainties reduced. SDMs can provide a useful way to incorporate future conditions into conservation and management practices and decisions, but the uncertainties of model projections must be balanced with the risks of taking the wrong actions or the costs of inaction. Doing this will require that the sources and magnitudes of uncertainty are documented, and that conservationists and resource managers be willing to act despite the uncertainties. The alternative, of ignoring the future, is not an option. PMID:19822750
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Taylor, Michael J; Taylor, Dave; Vlaev, Ivo; Elkin, Sarah
2017-01-01
Recent advances in communication technologies enable potential provision of remote education for patients using computer-generated environments known as virtual worlds. Previous research has revealed highly variable levels of patient receptiveness to using information technologies for healthcare-related purposes. This preliminary study involved implementing a questionnaire investigating attitudes and access to computer technologies of respiratory outpatients, in order to assess potential for use of virtual worlds to facilitate health-related education for this sample. Ninety-four patients with a chronic respiratory condition completed surveys, which were distributed at a Chest Clinic. In accordance with our prediction, younger participants were more likely to be able to use, and have access to a computer and some patients were keen to explore use virtual worlds for healthcare-related purposes: Of those with access to computer facilities, 14.50% expressed a willingness to attend a virtual world focus group. Results indicate future virtual world health education facilities should be designed to cater for younger patients, because this group are most likely to accept and use such facilities. Within the study sample, this is likely to comprise of people diagnosed with asthma. Future work could investigate the potential of creating a virtual world asthma education facility.
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Taylor, Michael J.; Taylor, Dave; Vlaev, Ivo; Elkin, Sarah
2015-01-01
Recent advances in communication technologies enable potential provision of remote education for patients using computer-generated environments known as virtual worlds. Previous research has revealed highly variable levels of patient receptiveness to using information technologies for healthcare-related purposes. This preliminary study involved implementing a questionnaire investigating attitudes and access to computer technologies of respiratory outpatients, in order to assess potential for use of virtual worlds to facilitate health-related education for this sample. Ninety-four patients with a chronic respiratory condition completed surveys, which were distributed at a Chest Clinic. In accordance with our prediction, younger participants were more likely to be able to use, and have access to a computer and some patients were keen to explore use virtual worlds for healthcare-related purposes: Of those with access to computer facilities, 14.50% expressed a willingness to attend a virtual world focus group. Results indicate future virtual world health education facilities should be designed to cater for younger patients, because this group are most likely to accept and use such facilities. Within the study sample, this is likely to comprise of people diagnosed with asthma. Future work could investigate the potential of creating a virtual world asthma education facility. PMID:28239187
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Wald, David J.; Hayes, Gavin P.; Benz, Harley M.; Earle, Paul S.; Briggs, Richard W.
2011-01-01
The M 9.0 11 March 2011 Tohoku, Japan, earthquake and associated tsunami near the east coast of the island of Honshu caused tens of thousands of deaths and potentially over one trillion dollars in damage, resulting in one of the worst natural disasters ever recorded. The U.S. Geological Survey National Earthquake Information Center (USGS NEIC), through its responsibility to respond to all significant global earthquakes as part of the National Earthquake Hazards Reduction Program, quickly produced and distributed a suite of earthquake information products to inform emergency responders, the public, the media, and the academic community of the earthquake's potential impact and to provide scientific background for the interpretation of the event's tectonic context and potential for future hazard. Here we present a timeline of the NEIC response to this devastating earthquake in the context of rapidly evolving information emanating from the global earthquake-response community. The timeline includes both internal and publicly distributed products, the relative timing of which highlights the inherent tradeoffs between the requirement to provide timely alerts and the necessity for accurate, authoritative information. The timeline also documents the iterative and evolutionary nature of the standard products produced by the NEIC and includes a behind-the-scenes look at the decisions, data, and analysis tools that drive our rapid product distribution.
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Spatial quantification of the world population potentially exposed to Zika virus.
Alaniz, Alberto J; Bacigalupo, Antonella; Cattan, Pedro E
2017-06-01
Zika virus is an emerging Flaviviridae virus, which has spread rapidly in the last few years. It has raised concern because it has been associated with fetus microcephaly when pregnant women are infected. The main vector is the mosquito Aedes aegypti , distributed in tropical areas. Niche modelling techniques were used to estimate the potential distribution area of A. aegypti. This was overlapped with human population density, determining areas of potential transmission risk worldwide. Afterwards, we quantified the population at risk according to risk level. The vector transmission risk is distributed mainly in Asia and Oceania on the shores of the Indian Ocean. In America, the risk concentrates in the Atlantic coast of South America and in the Caribbean Sea shores in Central and North America. In Africa, the major risk is concentrated in the Pacific and Atlantic coasts of Central and South Africa. The world population under high and very high risk levels includes 2.261 billion people. These results illustrate Zika virus risk at the global level and provide maps to target the prevention and control measures especially in areas with higher risk, in countries with less sanitation and poorer resources. Many countries without previous vector reports could become active transmission zones in the future, so vector surveillance should be implemented or reinforced in these areas. © The Author 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association
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The remediation of heavy metals contaminated sediment.
Peng, Jian-Feng; Song, Yong-Hui; Yuan, Peng; Cui, Xiao-Yu; Qiu, Guang-Lei
2009-01-30
Heavy metal contamination has become a worldwide problem through disturbing the normal functions of rivers and lakes. Sediment, as the largest storage and resources of heavy metal, plays a rather important role in metal transformations. This paper provides a review on the geochemical forms, affecting factors and remediation technologies of heavy metal in sediment. The in situ remediation of sediment aims at increasing the stabilization of some metals such as the mobile and the exchangeable fractions; whereas, the ex situ remediation mainly aims at removing those potentially mobile metals, such as the Mn-oxides and the organic matter (OM) fraction. The pH and OM can directly change metals distribution in sediment; however oxidation-reduction potential (ORP), mainly through changing the pH values, indirectly alters metals distribution. Mainly ascribed to their simple operation mode, low costs and fast remediation effects, in situ remediation technologies, especially being fit for slight pollution sediment, are applied widely. However, for avoiding metal secondary pollution from sediment release, ex situ remediation should be the hot point in future research.
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Barbet-Massin, Morgane; Walther, Bruno A.; Thuiller, Wilfried; Rahbek, Carsten; Jiguet, Frédéric
2009-01-01
We modelled the present and future sub-Saharan winter distributions of 64 trans-Saharan migrant passerines to predict the potential impacts of climate change. These predictions used the recent ensemble modelling developments and the latest IPCC climatic simulations to account for possible methodological uncertainties. Results suggest that 37 species would face a range reduction by 2100 (16 of these by more than 50%); however, the median range size variation is −13 per cent (from −97 to +980%) under a full dispersal hypothesis. Range centroids were predicted to shift by 500±373 km. Predicted changes in range size and location were spatially structured, with species that winter in southern and eastern Africa facing larger range contractions and shifts. Predicted changes in regional species richness for these long-distance migrants are increases just south of the Sahara and on the Arabian Peninsula and major decreases in southern and eastern Africa. PMID:19324660
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Impact of Saw Dust Application on the Distribution of Potentially Toxic Metals in Contaminated Soil.
Awokunmi, Emmmanuel E
2017-12-01
The need to develop an approach for the reclamation of contaminated site using locally available agricultural waste has been considered. The present study investigated the application of sawdust as an effective amendment in the immobilization of potentially toxic metals (PTMs) by conducting a greenhouse experiment on soil collected from an automobile dumpsite. The amended and non-amended soil samples were analyzed for their physicochemical parameters and sequential extraction of PTMs. The results revealed that application of amendment had positive impact on the physicochemical parameters as organic matter content and cation exchange capacity increased from 12.1% to 12.8% and 16.4 to 16.8 meq/100 g respectively. However, the mobility and bioavalability of these metals was reduced as they were found to be distributed mostly in the non-exchangeable phase of soil. Therefore, application of sawdust successfully immobilized PTMs and could be applied for future studies in agricultural soil reclamation.
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NASA Astrophysics Data System (ADS)
Ziegler, Hannes Moritz
Planners and managers often rely on coarse population distribution data from the census for addressing various social, economic, and environmental problems. In the analysis of physical vulnerabilities to sea-level rise, census units such as blocks or block groups are coarse relative to the required decision-making application. This study explores the benefits offered from integrating image classification and dasymetric mapping at the household level to provide detailed small area population estimates at the scale of residential buildings. In a case study of Boca Raton, FL, a sea-level rise inundation grid based on mapping methods by NOAA is overlaid on the highly detailed population distribution data to identify vulnerable residences and estimate population displacement. The enhanced spatial detail offered through this method has the potential to better guide targeted strategies for future development, mitigation, and adaptation efforts.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Backus, George A.; Lowry, Thomas Stephen; Jones, Shannon M
This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plusmore » two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconomic impacts. The full report is contained in 27 volumes.« less
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Roy-Dufresne, Emilie; Logan, Travis; Simon, Julie A; Chmura, Gail L; Millien, Virginie
2013-01-01
The white-footed mouse (Peromyscus leucopus) is an important reservoir host for Borrelia burgdorferi, the pathogen responsible for Lyme disease, and its distribution is expanding northward. We used an Ecological Niche Factor Analysis to identify the climatic factors associated with the distribution shift of the white-footed mouse over the last 30 years at the northern edge of its range, and modeled its current and potential future (2050) distributions using the platform BIOMOD. A mild and shorter winter is favouring the northern expansion of the white-footed mouse in Québec. With more favorable winter conditions projected by 2050, the distribution range of the white-footed mouse is expected to expand further northward by 3° latitude. We also show that today in southern Québec, the occurrence of B. burgdorferi is associated with high probability of presence of the white-footed mouse. Changes in the distribution of the white-footed mouse will likely alter the geographical range of B. burgdorferi and impact the public health in northern regions that have yet to be exposed to Lyme disease.
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Song, Yongze; Ge, Yong; Wang, Jinfeng; Ren, Zhoupeng; Liao, Yilan; Peng, Junhuan
2016-07-07
Malaria is one of the most severe parasitic diseases in the world. Spatial distribution estimation of malaria and its future scenarios are important issues for malaria control and elimination. Furthermore, sophisticated nonlinear relationships for prediction between malaria incidence and potential variables have not been well constructed in previous research. This study aims to estimate these nonlinear relationships and predict future malaria scenarios in northern China. Nonlinear relationships between malaria incidence and predictor variables were constructed using a genetic programming (GP) method, to predict the spatial distributions of malaria under climate change scenarios. For this, the examples of monthly average malaria incidence were used in each county of northern China from 2004 to 2010. Among the five variables at county level, precipitation rate and temperature are used for projections, while elevation, water density index, and gross domestic product are held at their present-day values. Average malaria incidence was 0.107 ‰ per annum in northern China, with incidence characteristics in significant spatial clustering. A GP-based model fit the relationships with average relative error (ARE) = 8.127 % for training data (R(2) = 0.825) and 17.102 % for test data (R(2) = 0.532). The fitness of GP results are significantly improved compared with those by generalized additive models (GAM) and linear regressions. With the future precipitation rate and temperature conditions in Special Report on Emission Scenarios (SRES) family B1, A1B and A2 scenarios, spatial distributions and changes in malaria incidences in 2020, 2030, 2040 and 2050 were predicted and mapped. The GP method increases the precision of predicting the spatial distribution of malaria incidence. With the assumption of varied precipitation rate and temperature, and other variables controlled, the relationships between incidence and the varied variables appear sophisticated nonlinearity and spatially differentiation. Using the future fluctuated precipitation and the increased temperature, median malaria incidence in 2020, 2030, 2040 and 2050 would significantly increase that it might increase 19 to 29 % in 2020, but currently China is in the malaria elimination phase, indicating that the effective strategies and actions had been taken. While the mean incidences will not increase even reduce due to the incidence reduction in high-risk regions but the simultaneous expansion of the high-risk areas.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, Ning; Yearsley, John; Baptiste, Marisa
While the effects of land use change in urban areas have been widely examined, the combined effects of climate and land use change on the quality of urban and urbanizing streams have received much less attention. We describe a modeling framework that is applicable to the evaluation of potential changes in urban water quality and associated hydrologic changes in response to ongoing climate and landscape alteration. The grid-based spatially distributed model, DHSVM-WQ, is an outgrowth of the Distributed Hydrology-Soil-Vegetation Model (DHSVM) that incorporates modules for assessing hydrology and water quality in urbanized watersheds at a high spatial and temporal resolution.more » DHSVM-WQ simulates surface runoff quality and in-stream processes that control the transport of nonpoint-source (NPS) pollutants into urban streams. We configure DHSVM-WQ for three partially urbanized catchments in the Puget Sound region to evaluate the water quality responses to current conditions and projected changes in climate and/or land use over the next century. Here we focus on total suspended solids (TSS) and total phosphorus (TP) from nonpoint sources (runoff), as well as stream temperature. The projection of future land use is characterized by a combination of densification in existing urban or partially urban areas, and expansion of the urban footprint. The climate change scenarios consist of individual and concurrent changes in temperature and precipitation. Future precipitation is projected to increase in winter and decrease in summer, while future temperature is projected to increase throughout the year. Our results show that urbanization has a much greater effect than climate change on both the magnitude and seasonal variability of streamflow, TSS and TP loads largely due to substantially increased streamflow, and particularly winter flow peaks. Water temperature is more sensitive to climate warming scenarios than to urbanization and precipitation changes. Future urbanization and climate change together are predicted to significantly increase annual mean streamflow (up to 55%), water temperature (up to 1.9 ºC), TSS load (up to 182%), and TP load (up to 74%).« less
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Use of the Beaufort Sea by king eiders breeding on the North Slope of Alaska
Phillips, Laura M.; Powell, A.N.; Taylor, E.J.; Rexstad, E.A.
2007-01-01
We estimated areas used by king eiders (Somateria spectabilis) in the Alaskan Beaufort Sea, how distributions of used areas varied, and characteristics that explained variation in the number of days spent at sea, to provide regulatory agencies with baseline data needed to minimize impacts of potential offshore oil development. We implanted sixty king eiders with satellite transmitters at nesting areas on the North Slope of Alaska, USA, in 2002-2004. More than 80% of marked eiders spent >2 weeks staging offshore prior to beginning a postbreeding molt migration. During postbreeding staging and migration, male king eiders had much broader distributions in the Alaskan Beaufort Sea than female eiders, which were concentrated in Harrison and Smith Bays. Distribution did not vary by sex during spring migration in the year after marking. Shorter residence times of eiders and deeper water at locations used during spring migration suggest the Alaskan Beaufort Sea might not be as critical a staging area for king eiders during prebreeding as it is postbreeding. Residence time in the Beaufort Sea varied by sex, with female king eiders spending more days at sea than males in spring and during postbreeding. We conclude the Alaskan Beaufort Sea is an important staging area for king eiders during postbreeding, and eider distribution should be considered by managers when mitigating for future offshore development. We recommend future studies examine the importance of spring staging areas outside the Alaskan Beaufort Sea.
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The impacts of climate change on the wintering distribution of an endangered migratory bird.
Hu, Junhua; Hu, Huijian; Jiang, Zhigang
2010-10-01
There is now ample evidence of the effects of anthropogenic climate change on the distribution and abundance of species. The black-faced spoonbill (Platalea minor) is an endangered migratory species and endemic to East Asia. Using a maximum entropy approach, we predicted the potential wintering distribution for spoonbills and modeled the effects of future climate change. Elevation, human influence index and precipitation during the coldest quarter contributed most to model development. Five regions, including western Taiwan, scattered locations from eastern coastal to central mainland China, coastal areas surrounding the South China Sea, northeastern coastal areas of Vietnam and sites along the coast of Japan, were found to have a high probability of presence and showed good agreement with historical records. Assuming no limits to the spread of this species, the wintering range is predicted to increase somewhat under a changing climate. However, three currently highly suitable regions (northeastern Vietnam, Taiwan and coastal areas surrounding the South China Sea) may face strong reductions in range by 2080. We also found that the center of the predicted range of spoonbills will undergo a latitudinal shift northwards by as much as 240, 450, and 600 km by 2020, 2050 and 2080, respectively. Our findings suggest that species distribution modeling can inform the current and future management of the black-faced spoonbill throughout Asia. It is clear that a strong international strategy is needed to conserve spoonbill populations under a changing climate.
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Determining the meson-nucleus potential - on the way to mesic states
NASA Astrophysics Data System (ADS)
Metag, Volker
2015-08-01
Experimental approaches to determine the real and imaginary part of the meson-nucleus potential are described. The experiments have been performed with the Crystal Barrel/TAPS detector at the electron accelerator ELSA (Bonn) and the Crystal Ball/TAPS detector at MAMI (Mainz). Measuring the transparency ratio as well as the excitation function and momentum distribution for photo production of ω and η' mesons, the imaginary part of the η'-nucleus potential is found to be smaller than the real part. In case of the ω meson the opposite is observed. This makes the η' meson a good candidate for the search for meson-nucleus bound states while no resolved ω mesic states can be expected. The results are discussed and compared to theoretical predictions. An outlook on future experiments is given.
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Electronic Health Records and US Public Health: Current Realities and Future Promise
Parrish, R. Gibson; Ross, David A.
2013-01-01
Electronic health records (EHRs) could contribute to improving population health in the United States. Realizing this potential will require understanding what EHRs can realistically offer to efforts to improve population health, the requirements for obtaining useful information from EHRs, and a plan for addressing these requirements. Potential contributions of EHRs to improving population health include better understanding of the level and distribution of disease, function, and well-being within populations. Requirements are improved population coverage of EHRs, standardized EHR content and reporting methods, and adequate legal authority for using EHRs, particularly for population health. A collaborative national effort to address the most pressing prerequisites for and barriers to the use of EHRs for improving population health is needed to realize the EHR’s potential. PMID:23865646
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Masoumi, Ali; Vilenkin, Alexander; Yamada, Masaki, E-mail: ali@cosmos.phy.tufts.edu, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: Masaki.Yamada@tufts.edu
In the landscape perspective, our Universe begins with a quantum tunneling from an eternally-inflating parent vacuum, followed by a period of slow-roll inflation. We investigate the tunneling process and calculate the probability distribution for the initial conditions and for the number of e-folds of slow-roll inflation, modeling the landscape by a small-field one-dimensional random Gaussian potential. We find that such a landscape is fully consistent with observations, but the probability for future detection of spatial curvature is rather low, P ∼ 10{sup −3}.
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Autofluorescence imaging of basal cell carcinoma by smartphone RGB camera
NASA Astrophysics Data System (ADS)
Lihachev, Alexey; Derjabo, Alexander; Ferulova, Inesa; Lange, Marta; Lihacova, Ilze; Spigulis, Janis
2015-12-01
The feasibility of smartphones for in vivo skin autofluorescence imaging has been investigated. Filtered autofluorescence images from the same tissue area were periodically captured by a smartphone RGB camera with subsequent detection of fluorescence intensity decreasing at each image pixel for further imaging the planar distribution of those values. The proposed methodology was tested clinically with 13 basal cell carcinoma and 1 atypical nevus. Several clinical cases and potential future applications of the smartphone-based technique are discussed.
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Autofluorescence imaging of basal cell carcinoma by smartphone RGB camera.
Lihachev, Alexey; Derjabo, Alexander; Ferulova, Inesa; Lange, Marta; Lihacova, Ilze; Spigulis, Janis
2015-01-01
The feasibility of smartphones for in vivo skin autofluorescence imaging has been investigated. Filtered autofluorescence images from the same tissue area were periodically captured by a smartphone RGB camera with subsequent detection of fluorescence intensity decreasing at each image pixel for further imaging the planar distribution of those values. The proposed methodology was tested clinically with 13 basal cell carcinoma and 1 atypical nevus. Several clinical cases and potential future applications of the smartphone-based technique are discussed.
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Otero-Ferrer, F; Herrera, R; López, A; Socorro, J; Molina, L; Bouza, C
2015-10-01
Morphometric and genetic analyses confirmed the first records of the West African seahorse Hippocampus algiricus at Gran Canaria Island (north-east Atlantic Ocean), and also the first evidence of interspecific hybridization in seahorses. These results provide additional data on the distribution of H. algiricus that may help to establish future conservation strategies, and uncover a new potential sympatric scenario between H. algiricus and Hippocampus hippocampus. © 2015 The Fisheries Society of the British Isles.
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The Sun as a sub-GeV dark matter accelerator
NASA Astrophysics Data System (ADS)
Emken, Timon; Kouvaris, Chris; Nielsen, Niklas Grønlund
2018-03-01
Sub-GeV halo dark matter that enters the Sun can potentially scatter off hot solar nuclei and be ejected much faster than its incoming velocity. We derive an expression for the rate and velocity distribution of these reflected particles, taking into account the Sun's temperature and opacity. We further demonstrate that future direct-detection experiments could use these energetic reflected particles to probe light dark matter in parameter space that cannot be accessed via ordinary halo dark matter.