Showing papers by "University of New Hampshire published in 2011"
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McGill University1, University of Washington2, The Nature Conservancy3, City University of New York4, European Environment Agency5, Goethe University Frankfurt6, Food and Agriculture Organization7, University of Yamanashi8, Umeå University9, University of Greifswald10, World Wide Fund for Nature11, University of New Hampshire12
TL;DR: Despite the recognized importance of reservoirs and dams, global datasets describing their characteristics and geographical distribution are largely incomplete as mentioned in this paper, which makes it difficult to perform advanced assessments of dams and reservoirs.
Abstract: Despite the recognized importance of reservoirs and dams, global datasets describing their characteristics and geographical distribution are largely incomplete. To enable advanced assessments of th ...
1,493 citations
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Indiana University1, Utah State University2, University of Notre Dame3, University of New Hampshire4, University of California, Santa Barbara5, University of Tokyo6, United States Department of Energy7, Ludwig Maximilian University of Munich8, J. Craig Venter Institute9, National Institutes of Health10, University of Illinois at Urbana–Champaign11, Hebrew University of Jerusalem12, University of North Texas13, Harvard University14, University of Geneva15, Research Institute of Molecular Pathology16, Oregon State University17, Utrecht University18, University of California, Davis19, Hoffmann-La Roche20, University of Iowa21, University of Strasbourg22, University of Washington23, University of Texas at Arlington24, University of California, Santa Cruz25, Life Technologies26, New York University27, University of Guelph28, Imperial College London29, University of California, Berkeley30
TL;DR: The Daphnia genome reveals a multitude of genes and shows adaptation through gene family expansions, and the coexpansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random.
Abstract: We describe the draft genome of the microcrustacean Daphnia pulex, which is only 200 megabases and contains at least 30,907 genes. The high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters. More than a third of Daphnia's genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the Daphnia lineage. The coexpansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random, and the analysis of gene expression under different environmental conditions reveals that numerous paralogs acquire divergent expression patterns soon after duplication. Daphnia-specific genes, including many additional loci within sequenced regions that are otherwise devoid of annotations, are the most responsive genes to ecological challenges.
1,204 citations
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TL;DR: In this paper, a new conceptual model that explicitly identifies the processes controlling soil organic matter availability for decomposition and allows a more explicit description of the factors regulating OM decomposition under different circumstances is presented.
Abstract: The response of soil organic matter (OM) decomposition to increasing temperature is a critical aspect of ecosystem responses to global change The impacts of climate warming on decomposition dynamics have not been resolved due to apparently contradictory results from field and lab experiments, most of which has focused on labile carbon with short turnover times But the majority of total soil carbon stocks are comprised of organic carbon with turnover times of decades to centuries Understanding the response of these carbon pools to climate change is essential for forecasting longer-term changes in soil carbon storage Herein, we briefly synthesize information from recent studies that have been conducted using a wide variety of approaches In our effort to understand research to-date, we derive a new conceptual model that explicitly identifies the processes controlling soil OM availability for decomposition and allows a more explicit description of the factors regulating OM decomposition under different circumstances It explicitly defines resistance of soil OM to decomposition as being due either to its chemical conformation (quality )o r its physico-chemical protection from decomposition The former is embodied in the depolymerization process, the latter by adsorption/desorption and aggregate turnover We hypothesize a strong role for variation in temperature sensitivity as a function of reaction rates for both We conclude that important advances in understanding the temperature response of the processes that control substrate availability, depolymerization, microbial efficiency, and enzyme production will be needed to predict the fate of soil carbon stocks in a warmer world
1,175 citations
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University of North Texas1, East Malling Research Station2, Plant & Food Research3, Oregon State University4, University of Maryland, College Park5, Indiana University6, Virginia Tech7, Georgia Institute of Technology8, University of New Hampshire9, United States Department of Agriculture10, Hoffmann-La Roche11, University of Auckland12, Rutgers University13, University of the Western Cape14, University of Florida15, University of Chile16, Andrés Bello National University17, Weizmann Institute of Science18, University of Pittsburgh19, University of Georgia20, Technische Universität München21, University of Illinois at Urbana–Champaign22, Institut national de la recherche agronomique23
TL;DR: New phylogenetic analysis of 154 protein-coding genes suggests that assignment of Populus to Malvidae, rather than Fabidae, is warranted, and macrosyntenic relationships between Fragaria and Prunus predict a hypothetical ancestral Rosaceae genome that had nine chromosomes.
Abstract: The woodland strawberry, Fragaria vesca (2n = 2x = 14), is a versatile experimental plant system. This diminutive herbaceous perennial has a small genome (240 Mb), is amenable to genetic transformation and shares substantial sequence identity with the cultivated strawberry (Fragaria × ananassa) and other economically important rosaceous plants. Here we report the draft F. vesca genome, which was sequenced to ×39 coverage using second-generation technology, assembled de novo and then anchored to the genetic linkage map into seven pseudochromosomes. This diploid strawberry sequence lacks the large genome duplications seen in other rosids. Gene prediction modeling identified 34,809 genes, with most being supported by transcriptome mapping. Genes critical to valuable horticultural traits including flavor, nutritional value and flowering time were identified. Macrosyntenic relationships between Fragaria and Prunus predict a hypothetical ancestral Rosaceae genome that had nine chromosomes. New phylogenetic analysis of 154 protein-coding genes suggests that assignment of Populus to Malvidae, rather than Fabidae, is warranted.
1,085 citations
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University of Maryland, College Park1, Pacific Northwest National Laboratory2, University of New Hampshire3, Met Office4, University of Kansas5, International Institute for Applied Systems Analysis6, Woods Hole Research Center7, Ibaraki University8, Netherlands Environmental Assessment Agency9, Princeton University10, Oak Ridge National Laboratory11, Utrecht University12, CSIRO Marine and Atmospheric Research13
TL;DR: In this paper, a harmonized set of land-use scenarios is presented that smoothly connects historical reconstructions of land use with future projections, in the format required by ESMs, in preparation for the fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC).
Abstract: In preparation for the fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), the international community is developing new advanced Earth System Models (ESMs) to assess the combined effects of human activities (e.g. land use and fossil fuel emissions) on the carbon-climate system. In addition, four Representative Concentration Pathway (RCP) scenarios of the future (2005–2100) are being provided by four Integrated Assessment Model (IAM) teams to be used as input to the ESMs for future carbon-climate projections (Moss et al. 2010). The diversity of approaches and requirements among IAMs and ESMs for tracking land-use change, along with the dependence of model projections on land-use history, presents a challenge for effectively passing data between these communities and for smoothly transitioning from the historical estimates to future projections. Here, a harmonized set of land-use scenarios are presented that smoothly connects historical reconstructions of land use with future projections, in the format required by ESMs. The land-use harmonization strategy estimates fractional land-use patterns and underlying land-use transitions annually for the time period 1500–2100 at 0.5° × 0.5° resolution. Inputs include new gridded historical maps of crop and pasture data from HYDE 3.1 for 1500–2005, updated estimates of historical national wood harvest and of shifting cultivation, and future information on crop, pasture, and wood harvest from the IAM implementations of the RCPs for the period 2005–2100. The computational method integrates these multiple data sources, while minimizing differences at the transition between the historical reconstruction ending conditions and IAM initial conditions, and working to preserve the future changes depicted by the IAMs at the grid cell level. This study for the first time harmonizes land-use history data together with future scenario information from multiple IAMs into a single consistent, spatially gridded, set of land-use change scenarios for studies of human impacts on the past, present, and future Earth system.
1,078 citations
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TL;DR: In this paper, the state of the art of electromagnetic forming is reviewed considering: • basic research work regarding the process principle, significant parameters on the acting loads, the resulting workpiece deformation, and their interactions, and the energy transfer during the process; • applicationoriented research work and applications in the field of forming, joining, cutting, and process combinations including electromagnetic forming incorporated into conventional forming technologies.
746 citations
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01 Feb 2011TL;DR: Two advanced data mining approaches, support vector machines and random forests, together with the well-known logistic regression, are evaluated as part of an attempt to better detect (and thus control and prosecute) credit card fraud.
Abstract: Credit card fraud is a serious and growing problem. While predictive models for credit card fraud detection are in active use in practice, reported studies on the use of data mining approaches for credit card fraud detection are relatively few, possibly due to the lack of available data for research. This paper evaluates two advanced data mining approaches, support vector machines and random forests, together with the well-known logistic regression, as part of an attempt to better detect (and thus control and prosecute) credit card fraud. The study is based on real-life data of transactions from an international credit card operation.
673 citations
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University of New Hampshire1, Old Dominion University2, Eduardo Mondlane University3, Universiti Putra Malaysia4, Silliman University5, University of Maryland Center for Environmental Science6, University of the Philippines7, National Institute of Oceanography, India8, University of Chittagong9, University of Western Australia10, National Oceanic and Atmospheric Administration11, Hasanuddin University12, Virginia Institute of Marine Science13, Prince of Songkla University14, National Autonomous University of Mexico15, James Cook University16, University of Virginia17
TL;DR: For the first time, the probability of extinction is determined for the world’s seagrass species under the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species.
629 citations
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TL;DR: Current understanding of plant spectral properties with respect to sources of uncertainty at leaf to canopy scales is reviewed and a pattern that emerges suggests a synergy among the scattering effects of leaf-, stem- and canopy-level traits that becomes most apparent in the near-infrared (NIR) region.
Abstract: How plants interact with sunlight is central to the existence of life and provides a window to the functioning of ecosystems. Although the basic properties of leaf spectra have been known for decades, interpreting canopy-level spectra is more challenging because leaf-level effects are complicated by a host of stem- and canopy-level traits. Progress has been made through empirical analyses and models, although both methods have been hampered by a series of persistent challenges. Here, I review current understanding of plant spectral properties with respect to sources of uncertainty at leaf to canopy scales. I also discuss the role of evolutionary convergence in plant functioning and the difficulty of identifying individual properties among a suite of interrelated traits. A pattern that emerges suggests a synergy among the scattering effects of leaf-, stem- and canopy-level traits that becomes most apparent in the near-infrared (NIR) region. This explains the widespread and well-known importance of the NIR region in vegetation remote sensing, but presents an interesting paradox that has yet to be fully explored: that we can often gain more insight about the functioning of plants by examining wavelengths that are not used in photosynthesis than by examining those that are.
571 citations
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University of Notre Dame1, Michigan State University2, University of New Hampshire3, University of Wyoming4, Oak Ridge National Laboratory5, University of Tennessee6, Marine Biological Laboratory7, Oregon State University8, University of Maryland, College Park9, University of New Mexico10, Kansas State University11, United States Department of Agriculture12, Montana State University13, Virginia Tech14, Central Washington University15, Ball State University16, Wright State University17, University of Georgia18, Indiana University19, University of Canterbury20, United States Geological Survey21, Arizona State University22, Washington State University Vancouver23
TL;DR: It is found that stream denitrification produces N2O at rates that increase with stream water nitrate (NO3−) concentrations, but that <1% of denitrified N is converted to N1O, and it is suggested that increased stream NO3− loading stimulatesDenitrification and concomitant N2o production, but does not increase the N2 O yield.
Abstract: Nitrous oxide (N2O) is a potent greenhouse gas that contributes to climate change and stratospheric ozone destruction. Anthropogenic nitrogen (N) loading to river networks is a potentially important source of N2O via microbial denitrification that converts N to N2O and dinitrogen (N2). The fraction of denitrified N that escapes as N2O rather than N2 (i.e., the N2O yield) is an important determinant of how much N2O is produced by river networks, but little is known about the N2O yield in flowing waters. Here, we present the results of whole-stream 15N-tracer additions conducted in 72 headwater streams draining multiple land-use types across the United States. We found that stream denitrification produces N2O at rates that increase with stream water nitrate (NO3−) concentrations, but that <1% of denitrified N is converted to N2O. Unlike some previous studies, we found no relationship between the N2O yield and stream water NO3−. We suggest that increased stream NO3− loading stimulates denitrification and concomitant N2O production, but does not increase the N2O yield. In our study, most streams were sources of N2O to the atmosphere and the highest emission rates were observed in streams draining urban basins. Using a global river network model, we estimate that microbial N transformations (e.g., denitrification and nitrification) convert at least 0.68 Tg·y−1 of anthropogenic N inputs to N2O in river networks, equivalent to 10% of the global anthropogenic N2O emission rate. This estimate of stream and river N2O emissions is three times greater than estimated by the Intergovernmental Panel on Climate Change.
536 citations
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United States Geological Survey1, Joint Global Change Research Institute2, University of Idaho3, Peking University4, University of Toronto5, South China Agricultural University6, University of Alaska Fairbanks7, University of New Hampshire8, Beijing Normal University9, Marine Biological Laboratory10, University of Oklahoma11, Ames Research Center12
TL;DR: A review of the status and major challenges in representing the impacts of disturbances in modeling the carbon dynamics across North America revealed some major advances and challenges as mentioned in this paper, and significant advances have been made in representation, scaling, and characterization of disturbances that should be included in regional modeling efforts.
Abstract: [1] Forest disturbances greatly alter the carbon cycle at various spatial and temporal scales. It is critical to understand disturbance regimes and their impacts to better quantify regional and global carbon dynamics. This review of the status and major challenges in representing the impacts of disturbances in modeling the carbon dynamics across North America revealed some major advances and challenges. First, significant advances have been made in representation, scaling, and characterization of disturbances that should be included in regional modeling efforts. Second, there is a need to develop effective and comprehensive process‐based procedures and algorithms to quantify the immediate and long‐term impacts of disturbances on ecosystem succession, soils, microclimate, and cycles of carbon, water, and nutrients. Third, our capability to simulate the occurrences and severity of disturbances is very limited. Fourth, scaling issues have rarely been addressed in continental scale model applications. It is not fully understood which finer scale processes and properties need to be scaled to coarser spatial and temporal scales. Fifth, there are inadequate databases on disturbances at the continental scale to support the quantification of their effects on the carbon balance in North America. Finally, procedures are needed to quantify the uncertainty of model inputs, model parameters, and model structures, and thus to estimate their impacts on overall model uncertainty. Working together, the scientific community interested in disturbance and its impacts can identify the most uncertain issues surrounding the role of disturbance in the North American carbon budget and develop working hypotheses to reduce the uncertainty.
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TL;DR: This paper found that there exist interaction effects between education or knowledge and political orientation, net of other background factors, in predicting public concern about climate change in the U.S. Two regional telephone surveys, conducted in New Hampshire and Michigan in 2008, included identical climate-change questions that provide opportunities to test this hypothesis.
Abstract: U.S. public opinion regarding climate change has become increasingly polarized in recent years, as partisan think tanks and others worked to recast an originally scientific topic into a political wedge issue. Nominally “scientific” arguments against taking anthropogenic climate change seriously have been publicized to reach informed but ideologically receptive audiences. Reflecting the success of such arguments, polls have noted that concern about climate change increased with education among Democrats, but decreased with education among Republicans. These observations lead to the hypothesis that there exist interaction (non-additive) effects between education or knowledge and political orientation, net of other background factors, in predicting public concern about climate change. Two regional telephone surveys, conducted in New Hampshire (n = 541) and Michigan (n = 1, 008) in 2008, included identical climate-change questions that provide opportunities to test this hypothesis. Multivariate analysis of both surveys finds significant interactions. These empirical results fit with theoretical interpretations and several other recent studies. They suggest that the classically identified social bases of concern about the environment in general, and climate in particular, have shifted in recent years. Narrowcast media, including the many Web sites devoted to discrediting climate-change concerns, provide ideal conduits for channeling contrarian arguments to an audience predisposed to believe and electronically spread them further. Active-response Web sites by climate scientists could prove critical to counterbalancing contrarian arguments.
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University of Leeds1, National Institute of Amazonian Research2, Forestry Commission3, Wageningen University and Research Centre4, James Cook University5, University of St Andrews6, Indiana University7, Paul Sabatier University8, Forest Research Institute9, University of São Paulo10, University of Edinburgh11, University of Waterloo12, University of New Hampshire13, Hokkaido University14, Universiti Brunei Darussalam15, Forest Research Institute Malaysia16, United States Forest Service17, Oregon State University18, University of Twente19, Universidade do Estado de Mato Grosso20, University of York21, Commonwealth Scientific and Industrial Research Organisation22, National University of Colombia23, University of Cambridge24, University of Yaoundé I25
TL;DR: In this article, the authors developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries, and used this database to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap).
Abstract: . Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were: 1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap). 2. to ascertain if the H:D relationship is modulated by climate and/or forest structural characteristics (e.g. stand-level basal area, A). 3. to develop H:D allometric equations and evaluate biases to reduce error in future local-to-global estimates of tropical forest biomass. Annual precipitation coefficient of variation (PV), dry season length (SD), and mean annual air temperature (TA) emerged as key drivers of variation in H:D relationships at the pantropical and region scales. Vegetation structure also played a role with trees in forests of a high A being, on average, taller at any given D. After the effects of environment and forest structure are taken into account, two main regional groups can be identified. Forests in Asia, Africa and the Guyana Shield all have, on average, similar H:D relationships, but with trees in the forests of much of the Amazon Basin and tropical Australia typically being shorter at any given D than their counterparts elsewhere. The region-environment-structure model with the lowest Akaike's information criterion and lowest deviation estimated stand-level H across all plots to within amedian −2.7 to 0.9% of the true value. Some of the plot-to-plot variability in H:D relationships not accounted for by this model could be attributed to variations in soil physical conditions. Other things being equal, trees tend to be more slender in the absence of soil physical constraints, especially at smaller D. Pantropical and continental-level models provided less robust estimates of H, especially when the roles of climate and stand structure in modulating H:D allometry were not simultaneously taken into account.
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TL;DR: In this article, the vulnerability of the North American high-latitude soil organic carbon (SOC) pool to climate change has been discussed, where the authors divide the current northern highlatitude organic carbon pools into near-surface soils where SOC is affected by seasonal freeze-thaw processes and changes in moisture status, and deeper permafrost and peatland strata down to several tens of meters depth where organic carbon is usually not affected by short-term changes.
Abstract: [1] This synthesis addresses the vulnerability of the North American high‐latitude soil organic carbon (SOC) pool to climate change Disturbances caused by climate warming in arctic, subarctic, and boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts We divide the current northern high‐latitude SOC pools into (1) near‐surface soils where SOC is affected by seasonal freeze‐thaw processes and changes in moisture status, and (2) deeper permafrost and peatland strata down to several tens of meters depth where SOC is usually not affected by short‐term changes We address key factors (permafrost, vegetation, hydrology, paleoenvironmental history) and processes (C input, storage, decomposition, and output) responsible for the formation of the large high‐latitude SOC pool in North America and highlight how climate‐related disturbances could alter this pool’s character and size Press disturbances of relatively slow but persistent nature such as top‐down thawing of permafrost, and changes in hydrology, microbiological communities, pedological processes, and vegetation types, as well as pulse disturbances of relatively rapid and local nature such as wildfires and thermokarst, could substantially impact SOC stocks Ongoing climate warming in the North American high‐latitude region could result in crossing environmental thresholds, thereby accelerating press disturbances and increasingly triggering pulse disturbances and eventually affecting the C source/sink net character of northern high‐latitude soils Finally, we assess postdisturbance feedbacks, models, and predictions for the northern high‐latitude SOC pool, and discuss data and research gaps to be addressed by future research
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TL;DR: This methane release simulates a rapid and relatively short-term natural release from hydrates into deep water and suggests that a vigorous deepwater bacterial bloom respired nearly all the released methane within this time, and that by analogy, large-scale releases of methane from hydrate in the deep ocean are likely to be met by a similarly rapid methanotrophic response.
Abstract: Methane was the most abundant hydrocarbon released during the 2010 Deepwater Horizon oil spill in the Gulf of Mexico. Beyond relevancy to this anthropogenic event, this methane release simulates a rapid and relatively short-term natural release from hydrates into deep water. Based on methane and oxygen distributions measured at 207 stations throughout the affected region, we find that within ~120 days from the onset of release ~3.0 × 1010 to 3.9 × 1010 moles of oxygen were respired, primarily by methanotrophs, and left behind a residual microbial community containing methanotrophic bacteria. We suggest that a vigorous deepwater bacterial bloom respired nearly all the released methane within this time, and that by analogy, large-scale releases of methane from hydrate in the deep ocean are likely to be met by a similarly rapid methanotrophic response.
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TL;DR: In this article, the authors examine the ways in which the MENA countries are vulnerable to climate-induced impacts on water resources and conclude that the key capacities for adaptive governance to water scarcity in MENA are underdeveloped.
Abstract: Through an examination of global climate change models combined with hydrological data on deteriorating water quality in the Middle East and North Africa (MENA), we elucidate the ways in which the MENA countries are vulnerable to climate-induced impacts on water resources. Adaptive governance strategies, however, remain a low priority for political leaderships in the MENA region. To date, most MENA governments have concentrated the bulk of their resources on large- scale supply side projects such as desalination, dam construction, inter-basin water transfers, tapping fossil groundwater aquifers, and importing virtual water. Because managing water demand, improving the efficiency of water use, and promoting conservation will be key ingredients in responding to climate-induced impacts on the water sector, we analyze the political, economic, and institutional drivers that have shaped governance responses. While the scholarly literature emphasizes the importance of social capital to adaptive governance, we find that many political leaders and water experts in the MENA rarely engage societal actors in considering water risks. We conclude that the key capacities for adaptive governance to water scarcity in MENA are underdeveloped.
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TL;DR: In this paper, the authors address the contradiction between the conceptualization of partner violence as almost exclusively perpetrated by men and over 200 studies with data on both men and women which found "gender symmetry," i.e., that about the same percentage of women as men physically assault a partner.
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TL;DR: This is the first study to ask children and caregivers about exposure to a range of violence, crime, and abuse in children’s lives and the research findings reported here are critical to informing efforts to protect children from its damaging effects.
Abstract: A Message from OJJDP: Children are exposed to violence every day in their homes, schools, and communities. Such exposure can cause them significant physical, mental, and emotional harm with long-term effects that can last well into adulthood. The Attorney General launched Defending Childhood in September 2010 to unify the Department of Justice’s efforts to address children’s exposure to violence under one initiative. Through Defending Childhood, the Department is raising public awareness about the issue and supporting practitioners, researchers, and policymakers as they seek solutions to address it. A component of Defending Childhood, OJJDP’s Safe Start initiative continues efforts begun in 1999 to enhance practice, research, training and technical assistance, and public education about children and violence. Under Safe Start, OJJDP conducted the National Survey of Children’s Exposure to Violence, the most comprehensive effort to date to measure the extent and nature of the violence that children endure and its consequences on their lives. This is the first study to ask children and caregivers about exposure to a range of violence, crime, and abuse in children’s lives. As amply evidenced in this bulletin series, children’s exposure to violence is pervasive and affects all ages. The research findings reported here and in the other bulletins in this series are critical to informing our efforts to protect children from its damaging effects
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TL;DR: In this paper, the authors use ecological models by Bronfenbrenner (1977, 2005) and Kelly (2006) to expand their view of key factors that help promote and may serve as barriers to helpful bystander intervention.
Abstract: Given the prevalence of sexual and relationship violence in communities, innovations in prevention are sought. One promising line of inquiry directs efforts not at victims or perpetrators but at community members who are potential witnesses to high-risk events along the continuum of violence or who may need to support victims after an assault. To date, the main organizing framework for understanding bystander behavior is the work of Latane and Darley (1970), who described a series of stages that lead to an individual’s decision to intervene or not when someone needs help. Yet this model focuses mainly on factors within the individual or his or her immediate context. In the current review, I use ecological models by Bronfenbrenner (1977, 2005) and Kelly (2006) to expand our view of key factors that help promote and may serve as barriers to helpful bystander intervention. For example, ecological theories suggest important community-level variables, such as campus size or cultural values, that may influence the degree of helping and may, in some instances, be leverage points for creating change.
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Yerevan Physics Institute1, Syracuse University2, University of Kentucky3, Saint Mary's University4, College of William & Mary5, University of Virginia6, University of New Hampshire7, New York University8, Florida International University9, Thomas Jefferson National Accelerator Facility10, Stanford University11, North Carolina Agricultural and Technical State University12, Carnegie Mellon University13, Longwood University14, Massachusetts Institute of Technology15, California State University, Los Angeles16, Norfolk State University17, Kent State University18, University of Massachusetts Amherst19, University of South Carolina20, Tel Aviv University21, Perimeter Institute for Theoretical Physics22, George Washington University23
TL;DR: In this paper, a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons was conducted using APEX test run data.
Abstract: We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'→ e+ e- reaction, and set an upper limit of α'/α ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.
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TL;DR: The red algal order Bangiales has been revised as a result of detailed regional studies and the development of expert local knowledge of Bangials floras, followed by collaborative global analyses based on wide taxon sampling and molecular analyses as mentioned in this paper.
Abstract: The red algal order Bangiales has been revised as a result of detailed regional studies and the development of expert local knowledge of Bangiales floras, followed by collaborative global analyses based on wide taxon sampling and molecular analyses. Combined analyses of the nuclear SSU rRNA gene and the plastid RUBISCO LSU (rbcL) gene for 157 Bangiales taxa have been conducted. Fifteen genera of Bangiales, seven filamentous and eight foliose, are recognized. This classification includes five newly described and two resurrected genera. This revision constitutes a major change in understanding relationships and evolution in this order. The genus Porphyra is now restricted to five described species and a number of undescribed species. Other foliose taxa previously placed in Porphyra are now recognized to belong to the genera Boreophyllum gen. nov., Clymene gen. nov., Fuscifolium gen. nov., Lysithea gen. nov., Miuraea gen. nov., Pyropia, and Wildemania. Four of the seven filamentous genera recognized in our analyses already have generic names (Bangia, Dione, Minerva, and Pseudobangia), and are all currently monotypic. The unnamed filamentous genera are clearly composed of multiple species, and few of these species have names. Further research is required: the genus to which the marine taxon Bangia fuscopurpurea belongs is not known, and there are also a large number of species previously described as Porphyra for which nuclear SSU ribosomal RNA (nrSSU) or rbcL sequence data should be obtained so that they can be assigned to the appropriate genus.
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01 Jan 2011TL;DR: In this article, the authors examined the current evidence supporting the hypothesis that the production and accumulation of reactive oxygen species leads to oxidative stress and is the proximal cause of coral bleaching.
Abstract: Unprecedented changes in coral reef systems have focused attention on a wide range of stressors on local, regional, and global spatial scales but global climate change resulting in elevated seawater temperatures is widely accepted as having contributed to the major declines in coral cover or phase shifts in community structure on time scales never previously observed or recorded in the geological record. The major mechanism of scleractinian mortality as a result of global climate change is “coral bleaching,” the loss of the endosymbiotic dinoflagellates (=zooxanthellae) that occurs as part of the coral stress response to temperature perturbations in combination with several other synergistic factors. Over several years many studies have shown that the common mechanism underlying the stress response of corals to elevated temperatures is oxidative stress that is exacerbated when exposure to high irradiances of solar radiation accompanies the thermal insult. Oxidative stress, the production and accumulation of reduced oxygen intermediates such as superoxide radicals, singlet oxygen, hydrogen peroxide, and hydroxyl radicals can cause damage to lipids, proteins, and DNA. Reactive oxygen species are also important signal transduction molecules and mediators of damage in cellular processes, such as apoptosis, autophagy, and cell necrosis all of which are believed to have roles in coral bleaching depending on the intensity and duration of the environmental insult. This chapter examines the current evidence supporting the hypothesis that the production and accumulation of reactive oxygen species leads to oxidative stress and is the proximal cause of coral bleaching.
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TL;DR: Cortinarius, Tricholoma, Piloderma, and Suillus had the strongest evidence of consistent negative effects of N deposition, and Bankeraceae produce a distinct hydrophobic mat exploration type that may be important in N acquisition under conditions of low N availability.
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TL;DR: In this paper, the authors identify several crosscutting themes related to the role of plant-water relations in the ecohydrological literature, including the contrasting dynamics of water-limited and water-abundant ecosystems, transferring information about water fluxes across scales, understanding spatiotemporal heterogeneity and complexity, eco-rological triggers associated with threshold behavior and shifts between alternative stable states and the need for long-term data sets at multiple scales.
Abstract: Aims The field of ecohydrology is providing new theoretical frameworks and methodological approaches for understanding the complex interactions and feedbacks between vegetation and hydrologic flows at multiple scales. Here we review some of the major scientific and technological advances in ecohydrology as related to understanding the mechanisms by which plant–water relations influence water fluxes at ecosystem, watershed and landscape scales. Important Findings We identify several cross-cutting themes related to the role of plant– water relations in the ecohydrological literature, including the contrasting dynamics of water-limited and water-abundant ecosystems, transferring information about water fluxes across scales, understanding spatiotemporal heterogeneity and complexity, ecohydrological triggers associated with threshold behavior and shifts between alternative stable states and the need for long-term data sets at multiple scales. We then show how these themes are embedded within three key research areas where improved understanding of the linkages between plant–water relations and the hydrologic cycle have led to important advances in the field of ecohydrology: upscaling water fluxes from the leaf to the watershed and landscape, effects of plant–soil interactions on soil moisture dynamics and controls exerted by plant water use patterns and mechanisms on streamflow regime. In particular, we highlight several pressing environmental challenges facing society today where ecohydrology can contribute to the scientific knowledge for developing sound management and policy solutions. We conclude by identifying key challenges and opportunities for advancing contributions of plant–water relations research to ecohydrology in the future.
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TL;DR: Weakly group-theoretical fusion categories have been shown to be solvable in this article, which is a categorical analog of Burnside's theorem for finite groups and has powerful applications to fusion categories and semisimple Hopf algebras of a given dimension.
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TL;DR: In this paper, the authors used a meta-analysis to identify the degree to which soil properties, agricultural management, and geographic location regulate microbial biomass response (carbon, Cmic; nitrogen, Nmic; and C:N ratio, C: N) to animal manure-based inputs relative to inorganic fertilizers.
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TL;DR: In this paper, a water-centric monthly scale simulation model (WaSSI-C) was developed by integrating empirical water and carbon flux measurements from the FLUXNET network and an existing water supply and demand accounting model, which was evaluated with basin-scale evapotranspiration (ET), gross ecosystem productivity (GEP), and net ecosystem exchange (NEE) estimates by multiple independent methods across 2103 eight-digit Hydrologic Unit Code watersheds in the conterminous United States from 2001 to 2006.
Abstract: [1] We developed a water-centric monthly scale simulation model (WaSSI-C) by integrating empirical water and carbon flux measurements from the FLUXNET network and an existing water supply and demand accounting model (WaSSI). The WaSSI-C model was evaluated with basin-scale evapotranspiration (ET), gross ecosystem productivity (GEP), and net ecosystem exchange (NEE) estimates by multiple independent methods across 2103 eight-digit Hydrologic Unit Code watersheds in the conterminous United States from 2001 to 2006. Our results indicate that WaSSI-C captured the spatial and temporal variability and the effects of large droughts on key ecosystem fluxes. Our modeled mean (±standard deviation in space) ET (556 ± 228 mm yr−1) compared well to Moderate Resolution Imaging Spectroradiometer (MODIS) based (527 ± 251 mm yr−1) and watershed water balance based ET (571 ± 242 mm yr−1). Our mean annual GEP estimates (1362 ± 688 g C m−2 yr−1) compared well (R2 = 0.83) to estimates (1194 ± 649 g C m−2 yr−1) by eddy flux-based EC-MOD model, but both methods led significantly higher (25–30%) values than the standard MODIS product (904 ± 467 g C m−2 yr−1). Among the 18 water resource regions, the southeast ranked the highest in terms of its water yield and carbon sequestration capacity. When all ecosystems were considered, the mean NEE (−353 ± 298 g C m−2 yr−1) predicted by this study was 60% higher than EC-MOD's estimate (−220 ± 225 g C m−2 yr−1) in absolute magnitude, suggesting overall high uncertainty in quantifying NEE at a large scale. Our water-centric model offers a new tool for examining the trade-offs between regional water and carbon resources under a changing environment.
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Desert Research Institute1, University of Nevada, Reno2, Oak Ridge National Laboratory3, University of Oklahoma4, University of Florida5, University of California, Berkeley6, University of Maine7, University of Washington8, University of Colorado Boulder9, University of New Hampshire10, University of Missouri11
TL;DR: Results from a systematic investigation of mercury (Hg) concentrations across 14 forest sites in the United States show highest concentrations in litter layers, strongly enriched in Hg compared to aboveground tissues and indicative of substantial postdepositional sorption of Hg.
Abstract: Results from a systematic investigation of mer- cury (Hg) concentrations across 14 forest sites in the United States show highest concentrations in litter layers, strongly enriched in Hg compared to aboveground tissues and indicative of substantial postdepositional sorption of Hg Soil Hg con- centrations were lower than in litter, with highest concentra- tions in surface soils Aboveground tissues showed no detectable spatial patterns, likely due to 17 different tree species present across sites Litter and soil Hg concentrations positively correlated with carbon (C), latitude, precipitation, and clay (in soil), which together explained up to 94% of concentration variability We observed strong latitudinal increases in Hg in soils and litter, in contrast to inverse latitudinal gradients of atmospheric deposition measures Soil and litter Hg concentrations were closely linked to C contents, consistent with well-known associations between organic matter and Hg, and we propose that C also shapes distribution of Hg in forests at continental scales TheconsistentlinkbetweenCandHgdistributionmayreflectalong-termlegacywherebyold,C-richsoilandlitterlayerssequester atmospheric Hg depositions over long time periods Based on a multiregression model, we present a distribution map of Hg concentrations in surface soils of the United States
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TL;DR: In this paper, the existence of a bound H dibaryon, an I = 0, J=0, s=-2 state with valence quark structure uuddss, at a pion mass of m(π)∼389
Abstract: We present evidence for the existence of a bound H dibaryon, an I=0, J=0, s=-2 state with valence quark structure uuddss, at a pion mass of m(π)∼389 MeV. Using the results of lattice QCD calculations performed on four ensembles of anisotropic clover gauge-field configurations, with spatial extents of L∼2.0, 2.5, 3.0, and 3.9 fm at a spatial lattice spacing of b(s)∼0.123 fm, we find an H dibaryon bound by B(∞)(H)=16.6±2.1±4.6 MeV at a pion mass of m(π)∼389 MeV.