72 research outputs found

    FOREST LOSS AND FRAGMENTATION IN SOUTHERN BAHIA, BRAZIL: IMPLICATIONS FOR THE EXTINCTION RISK OF GOLDEN-HEADED LION TAMARINS (Leontopithecus chrysomelas)

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    Golden-headed lion tamarins (GHLTs; Leontopithecus chrysomelas) are Endangered arboreal primates endemic to the Atlantic Forest of Brazil, where continuing loss of forest and its connectivity are major threats. The objectives of my research were to assess the vulnerability of GHLTs to habitat loss, fragmentation, and threats related to small population size in the context of past, current, and future trends in range-wide forest cover in Brazil's Atlantic Forest. I did this by conducting a supervised classification of Landsat 5TM remotely-sensed imagery to define past and current forest cover in the region, analyzing connectivity patterns in a graph theoretical framework, projecting recent deforestation patterns into the future using a multi-layer perceptron neural network, and modeling GHLT metapopulaton viability using population viability analysis. I found that forest cover has declined throughout the range of the species by 13% over the last 20 years, and only one habitat patch is large enough on its own to support a genetically viable GHLT population able to recover from extrinsic threats such as fire and disease. Functional landscape connectivity, which is important for population persistence, acquisition of resources, and maintenance of genetic diversity, is low at the distance and movement cost thresholds likely associated with this arboreal species that is rarely seen in non-forest matrix. The majority of remaining forest cover throughout the species' range is found in patches that are either (1) too small to support even a single group of GHLTs or (2) found at low elevations, in areas of high human population density, or in close proximity to previously cleared areas--conditions that are associated with past deforestation patterns and that make current habitat vulnerable to loss. Finally, I found that many of the known GHLT populations have a moderate to high risk of local extinction even over short time scales and assuming no further forest loss, and their presence may represent extinction debt. Continued deforestation will accelerate population declines and local extinction events. The results of my dissertation research suggest that GHLTs and their habitat face significant threats and low viability in the future because of both ultimate and proximate drivers of extinction

    Long Season Corn Silage Variety Trial

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    In 2014, the University of Vermont Northwest Extension Crops and Soils Team evaluated yield and quality of long season corn silage varieties at Borderview Research Farm in Alburgh, VT. Long season corn can be difficult to grow in Vermont, due to the climate’s restricted Growing Degree Days (GDDs). In addition, wet springs are becoming more common, delaying corn planting later into the season. However, on many farms, long season corn can produce higher yields and quality than many short season varieties. The test site was at Borderview Research Farm in Alburgh, VT, which has what is considered one of the longest growing seasons in Vermont (2,310 GDDs in 2014). In this year’s trial, 45 varieties were evaluated from eight different seed companies. While the information presented can begin to describe the yield and quality performance of these long season corn silage varieties in this region, it is important to note that the data represent results from only one season and one location. Compare other hybrid performance data before making varietal selections

    Organic Winter Wheat Variety Trial Report

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    In 2014, the University of Vermont Extension conducted an extensive organic variety trial to evaluate hard red winter wheat in order to determine which varieties thrive in the Northeast. The trial was established at the Borderview Research Farm in Alburgh, Vermont

    Organic Spring Wheat Variety Trial

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    In 2014, the University of Vermont Extension Northwest Crops and Soils Program evaluated nineteen hard red spring wheat to determine which varieties thrive in organic systems. The trial was established at the Borderview Research Farm in Alburgh, Vermont. Several varieties that did not perform well in previous trial years were eliminated from the 2014 variety trial. Newly released varieties were also sought for evaluation

    Corn Cropping Systems to Improve Economic and Environmental Health

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    In 2014, UVM Extension’s Northwest Crops & Soils Program initiated a trial at Borderview Research Farm in Alburgh, VT to assess the impact of corn cropping systems on overall health and productivity of the crop and soil. Yields are important, and they affect the bottom line immediately and obviously. Management choices involving crop rotation, tillage, nutrient management, and cover crops also make differences in the long term. Growing corn with practices that enhance soil quality and crop yields improves farm resiliency to both economics and the environment. This project evaluated yield and soil health effects of five different corn rotations: continuous corn, no-till, corn planted after perennial forage, corn planted after a cover crop of winter rye, and a perennial forage fescue

    Pernicious Patriarchy or Prosecutorial Progress?: Confronting Culture, War, and Rape in International Law

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    In the aftermath of the wars in the former Yugoslavia, feminist activists have encouraged the use of international law to prosecute those leaders employing rape as a tool for ethnic cleansing. First, we will analyze the reasons that rape is effective in disrupting social and against women. Second, we will elucidate the peculiar problems of prosecuting war criminals whose offenses targeted female non-combatants in the form of sexual violence. We begin with an examination of the international law related to war crimes, as well as the ethical implications of various techniques used to enforce the law and bring war criminals to justice. A brief examination of key areas of US rape law will demonstrate the relative leniency extended to perpetrators of violence against women domestically in a nation that guarantees women full juridical equality. After examining some specific prosecutions, we will apply the lessons learned to the larger context of international law

    Transient windows for connectivity in a changing world

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    The primary focus of studies examining metapopulation processes in dynamic or disturbance-dependent landscapes has been related to spatiotemporal changes in the habitat patches themselves. However, like the habitat patches, opportunities for movement between patches can also exist intermittently in dynamic landscapes, creating transient connectivity windows – which we define as a period of time during which matrix conditions increase the probability of one or more individuals moving successfully between habitat patches. Far less is known about the implications of dynamic changes in connectivity per se, and, to our knowledge, there are no connectivity metrics or metapopulation models that explicitly consider intermittent changes to connectivity between habitat patches. Consequently, in this paper, we examined the peer-reviewed, published literature up to November 2013 to better understand the consequences of variability in connectivity and to highlight knowledge gaps on this topic. First, we describe how connectivity per se can vary along a temporal gradient, offering examples of ecological systems that fall along this gradient. Second, we examine how temporal variability in connectivity is important for metapopulation dynamics, particularly given likely alterations to disturbance regimes as a result of global change. We conclude our review by briefly discussing key avenues for future connectivity-related research, all of which hinge on the need to perceive connectivity as a transient feature.https://doi.org/10.1186/2051-3933-2-

    Piping plovers demonstrate regional differences in nesting habitat selection patterns along the U. S. Atlantic coast

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    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Zeigler, S. L., Gutierrez, B. T., Hecht, A., Plant, N. G., & Sturdivant, E. J. Piping plovers demonstrate regional differences in nesting habitat selection patterns along the U. S. Atlantic coast. Ecosphere, 12(3), (2021): e03418, https://doi.org/10.1002/ecs2.3418.Habitat studies that encompass a large portion of a species’ geographic distribution can explain characteristics that are either consistent or variable, further informing inference from more localized studies and improving management successes throughout the range. We identified landscape characteristics at Piping Plover nests at 21 sites distributed from Massachusetts to North Carolina and compared habitat selection patterns among the three designated U.S. recovery units (New England, New York–New Jersey, and Southern). Geomorphic setting, substrate type, and vegetation type and density were determined in situ at 928 Piping Plover nests (hereafter, used resource units) and 641 random points (available resource units). Elevation, beach width, Euclidean distance to ocean shoreline, and least-cost path distance to low-energy shorelines with moist substrates (commonly used as foraging habitat) were associated with used and available resource units using remotely sensed spatial data. We evaluated multivariate differences in habitat selection patterns by comparing recovery unit-specific Bayesian networks. We then further explored individual variables that drove disparities among Bayesian networks using resource selection ratios for categorical variables and Welch’s unequal variances t-tests for continuous variables. We found that relationships among variables and their connections to habitat selection were similar among recovery units, as seen in commonalities in Bayesian network structures. Furthermore, nesting Piping Plovers consistently selected mixed sand and shell, gravel, or cobble substrates as well as areas with sparse or no vegetation, irrespective of recovery unit. However, we observed significant differences among recovery units in the elevations, distances to ocean, and distances to low-energy shorelines of used resource units. Birds also exhibited increased selectivity for overwash habitats and for areas with access to low-energy shorelines along a latitudinal gradient from north to south. These results have important implications for conservation and management, including assessment of shoreline stabilization and habitat restoration planning as well as forecasting effects of climate change.Funding for this work was provided by the North Atlantic Landscape Conservation Cooperative and U.S. Fish and Wildlife Service through a U.S. Geological Survey Mendenhall Fellowship to Zeigler. All other funding was through the U.S. Geological Survey (Zeigler, Gutierrez, Plant, and Sturdivant) and the U.S. Fish and Wildlife Service (Hecht). Zeigler, Plant, and Hecht conceived and designed the study and secured funding

    Impact of mask wearing during high-intensity exercise on post-exercise hemodynamics

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    Background: Few studies examining face mask wearing during high-intensity interval exercise (HIE) have measured blood pressure (BP) and cardiac output (Q) during exercise and none have examined these variables post-exercise. Methods: Participants were randomly assigned to complete four exercise and two control conditions while wearing different face masks. Participants followed a 4x4 protocol on a cycle ergometer. Participants exercised at 85% of VO2max for 4-min, followed by a 3-min rest, repeated four times. Measurements of Q, systemic vascular resistance (SVR), and BP were measured pre-exercise for 20-min, during exercise, and postexercise for 60-min. Linear mixed models were used to detect differences between conditions. Results: Ten young (20.3 ± 1.4 yr.) male (n = 5) and female (n = 5) participants with an average BMI of 28.1 ± 7.3 kg/m2 and VO2max of 37.0 ± 7.1 ml.kg-1.min-1 completed this. There were no group differences during exercise on outcomes of Q, SVR, HR, SBP, DBP, MAP, or RPE (all p > .05). During exercise, EXS-N95 had a lower SV than CON-E (p = .014) and EXS-CL (p = .006). All mask conditions had a higher post-exercise HR than CON-E (all p > .05). Only EXS-SUR differed in post-exercise brachial SBP compared to CON-E (3.1 ± 1.6 mmHg, p < .043). Of the exercise conditions, only EXS-N95 differed from CON-E with an increase of 2.0 ± .88 mmHg for brachial DBP (p = .022) and 2.1 ± .92 mmHg for central DBP (p = .022), SV (-11.8 ± 3.5 mL.min-1, p < .001), Q (-.52 ± .26 L.min-1, p = .045), and SVR (73.7 ± 29.8 Dyn.s/cm5, p = .014). Conclusion: The current study shows that in healthy populations, wearing a face covering of any type during HIE does not impactfully change the hemodynamic response during exercise or recovery period
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