250 research outputs found

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    Physiological integration of coral colonies is correlated with bleaching resistance

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    Inter-module physiological integration of colonial organisms can facilitate colony-wide coordinated responses to stimuli that strengthen colony fitness and stress resistance. In scleractinian corals, whose colonial integration ranges from isolated polyps to a seamless continuum of polyp structures and functions, this coordination improves responses to injury, predation, disease, and stress and may be one of the indications of an evolutionary origin of Symbiodinium symbiosis. However, observations of species-specific coral bleaching patterns suggest that highly integrated coral colonies may be more susceptible to thermal stress, and support the hypothesis that communication pathways between highly integrated polyps facilitate the dissemination of toxic byproducts created during the bleaching response. Here we reassess this hypothesis by parameterizing an integration index using 7 skeletal features that have been historically employed to infer physiological integration. We examine the relationship between this index and bleaching response across a phylogeny of 88 diverse coral species. Correcting for phylogenetic relationships among species in the analyses reveals significant patterns among species characters that could otherwise be obscured in simple cross-species comparisons using standard statistics, whose assumptions of independence are violated by the shared evolutionary history among species. Similar to the observed benefits of in creased coloniality for other types of stressors, the results indicate a significantly reduced bleaching response among coral species with highly integrated colonies

    Illinois Waterfowl Surveys and Investigations W-43-R-62 Annual Progress Report Period: 1 July 2014 – 30 June 2015

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    This study addresses the following objectives: 1)Inventory abundance and distribution of waterfowl and other waterbirds (a minimum of 10 species and guilds) during autumn migration at a minimum of 40 sites along the Illinois and central Mississippi rivers; 2) Investigate the ecology of canvasback and lesser scaup during spring migration in the central Illinois River valley (IRV) and Pool 19 of the Mississippi River; 3) Estimate waterfowl and other waterbird population sizes (a minimum of 10 species and guilds) during autumn migration using an aerial quadrat survey in the IRV for comparison with aerial inventories (Objective 1); 4) Determine breeding bird use of a minimum of 10 moist-soil wetlands managed for waterfowl during summer in central Illinois; 5) Investigate the breeding ecology of sandhill cranes during spring and summer in northeastern Illinois; 6) Distribute our findings to site managers and biologists, make recommendations for future management, and draw conclusions relevant to regional conservation planning during the project period as appropriate and requested.Illinois Department of Natural Resources, Division of Wildlife & U.S. Fish and Wildlife Service Contract Number: RC09-13FWUIUCunpublishednot peer reviewedOpe

    Pre-distortion adaptive optics for optical feeder links: simulations and performance analyses

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    Optical feeder links offer immense utility in meeting future communication demands—however, atmospheric turbulence limits their performance. This work targets this challenge through analyses of a bidirectional free-space optical communication (FSOC) link that incorporates pre-distortion adaptive optics (AO) between the next-generation optical ground station at the German Aerospace Center (DLR) Oberpfaffenhofen and the laser communications terminal on Alphasat—a satellite in geostationary orbit (GEO). The analyses are performed via end-to-end Monte Carlo simulations that provide realistic performance estimates of the bidirectional FSOC link for a GEO feeder link scenario. We find that applying pre-distortion AO reduces the total uplink losses of the bidirectional FSOC link by up to 10 dB and lessens the scintillation at the GEO satellite by an order of magnitude. Moreover, applying pre-distortion AO eases the link budget requirements needed for maintaining 99.9% link uptime by as much as 20-40 dB, while its use with a laser guide star shows an additional performance improvement of up to 8 dB. These findings demonstrate the desirability and feasibility of utilizing pre-distortion AO for the realization of optical feeder links

    Resource selection of deer hunters in Georgia\u27s Appalachian Mountains

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    White‐tailed deer (Odocoileus virginianus) and hunters on 2 Wildlife Management Areas (WMAs) within the Chattahoochee National Forest of northern Georgia, USA, significantly declined in number from the 1980s to 2018. Managers were interested in understanding how they could manipulate hunter distribution according to deer management goals. To understand the spatial distribution of hunting pressure and factors driving hunter resource selection, we analyzed GPS tracking data from 58 deer hunters over the 2018–2019 and 2019–2020 hunting seasons. We evaluated hunter selection on 3 spatial scales relative to elevation, slope, and distance from roads, trails, wildlife openings, deciduous forest, mixed forest, and evergreen forest. We incorporated covariates into 6 binary logistic regression models, plus a null model, within a used versus available framework. First, we compared hunter locations to available locations generated within the 2 WMAs. Elevation and distance to deciduous forest had the greatest effect on hunter selection, where hunters selected for lower elevations and closer proximity to deciduous forest. Second, we compared individual hunting bout locations to available locations generated within a buffer around the hunter\u27s starting location with a buffer radius equal to the maximum distance they travelled from their starting location. At the bout scale, distance to wildlife openings and elevation were the most important drivers of hunter selection; hunters selected areas closer to wildlife openings and higher elevations. Third, we compared individual hunter stand locations (used) to randomly selected locations along the hunter\u27s travel path (available). Only distance to roads and deciduous forest were significant in explaining hunter selection of stands. Hunters chose locations farther from roads and closer to deciduous forest relative to their travel paths. Mapping our WMA‐scale results revealed that only 5% of the total WMA area contained a greater relative probability of hunter selection compared to the probability of non‐selection. Our results suggest that vast refuge areas for deer likely existed on the WMAs during our study period. Manipulating hunter distribution is not necessary to aid in sustaining deer on either WMA at this time

    Illinois Waterfowl Surveys and Investigations W-43-R-64 Annual Progress Report FY2017 Period: 1 July 2016 – 30 June 2017

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    Objectives 1) Inventory abundance and distribution of waterfowl, shorebirds, and other waterbirds (a minimum of 10 species and guilds) during autumn migration at a minimum of 30 sites along and nearby the Illinois and central Mississippi rivers, 2) Estimate waterfowl and other waterbird population sizes (a minimum of 10 species and guilds) during autumn migration using an aerial quadrat survey in the central Illinois River Valley for comparison with aerial inventories (Objective 1), 3) Investigate movement and population ecology of lesser scaup, canvasback, and other diving ducks by trapping and leg-banding a minimum of 1,000 individuals during spring migration along the Illinois and Mississippi rivers, 4) Investigate the ecology of American green-winged teal and gadwall by radio-marking a minimum of 40 individuals of each species during spring migration in and nearby the central Illinois River Valley, 5) Investigate movements and home range size of a minimum of 10 Canada geese during winter in and near the Greater Chicago Metropolitan Area (GCMA) of Illinois, 6) Determine habitat quality of a minimum of 50 wetland and deepwater polygons during spring, summer, and early autumn for migrating dabbling ducks, breeding wetland birds, and migrating shorebirds in Illinois, and 7) Distribute results and findings to site managers and biologists of the Illinois Department of Natural Resources (IDNR) and other state agencies, the Mississippi Flyway Technical Section, the Upper Mississippi River and Great Lakes Region (UMRGLR) Joint Venture, the U.S. Fish and Wildlife Service, other scientists and collaborators as requested, and the general public through oral presentations, popular articles, technical reports, and peer reviewed publications; make recommendations for future wetland management practices and research needs based on results and related research; contribute to regional conservation planning efforts during the project period as appropriate and requested.Illinois Department of Natural Resources, Division of Wildlife & U.S. Fish and Wildlife Service Contract Number: RC09-13FWUIUCunpublishednot peer reviewedOpe

    Hydrophobicity drives the systemic distribution of lipid-conjugated siRNAs via lipid transport pathways

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    Efficient delivery of therapeutic RNA beyond the liver is the fundamental obstacle preventing its clinical utility. Lipid conjugation increases plasma half-life and enhances tissue accumulation and cellular uptake of small interfering RNAs (siRNAs). However, the mechanism relating lipid hydrophobicity, structure, and siRNA pharmacokinetics is unclear. Here, using a diverse panel of biologically occurring lipids, we show that lipid conjugation directly modulates siRNA hydrophobicity. When administered in vivo, highly hydrophobic lipid-siRNAs preferentially and spontaneously associate with circulating low-density lipoprotein (LDL), while less lipophilic lipid-siRNAs bind to high-density lipoprotein (HDL). Lipid-siRNAs are targeted to lipoprotein receptor-enriched tissues, eliciting significant mRNA silencing in liver (65%), adrenal gland (37%), ovary (35%), and kidney (78%). Interestingly, siRNA internalization may not be completely driven by lipoprotein endocytosis, but the extent of siRNA phosphorothioate modifications may also be a factor. Although biomimetic lipoprotein nanoparticles have been explored for the enhancement of siRNA delivery, our findings suggest that hydrophobic modifications can be leveraged to incorporate therapeutic siRNA into endogenous lipid transport pathways without the requirement for synthetic formulation

    Illinois Waterfowl Surveys and Investigations W-43-R-63 Annual Progress Report FY2016 Period: 1 July 2015 – 30 June 2016

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    Objectives 1) Inventory abundance and distribution of waterfowl and other waterbirds (a minimum of 10 species and guilds) during autumn migration at a minimum of 30 sites along the Illinois and central Mississippi rivers of Illinois, 2) Estimate waterfowl and other waterbird population sizes (a minimum of 10 species and guilds) during autumn migration using an aerial quadrat survey along the central Illinois River for comparison with aerial inventories (Objective 1), 3) Investigate the ecology of up to 50 gadwall and 50 American green-winged teal during spring migration in and near the central Illinois River valley of Illinois, 4) Determine breeding bird use of and nest density in a minimum of 10 moist-soil wetlands managed for waterfowl during summer in central Illinois, 5) Investigate the breeding ecology of a minimum of 50 sandhill cranes during spring and summer in northeastern Illinois consistent with an ongoing research project, 6) Investigate movements and home range size of a minimum of 10 Canada geese during winter in and near the Greater Chicago Metropolitan Area of Illinois, and 7) Determine habitat quality of a minimum of 100 wetlands and deepwater habitats during spring, summer, and early autumn for migrating dabbling ducks, breeding wetland birds, and migrating shorebirds in Illinois.Illinois Department of Natural Resources, Division of Wildlife & U.S. Fish and Wildlife Service Contract Number: RC09-13FWUIUCunpublishednot peer reviewedOpe

    Near-conformal dynamics in a chirally broken system

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    Composite Higgs models must exhibit very different dynamics from quantum chromodynamics (QCD) regardless whether they describe the Higgs boson as a dilaton-like state or a pseudo-Nambu-Goldstone boson. Large separation of scales and large anomalous dimensions are frequently desired by phenomenological models. Mass-split systems are well-suited for composite Higgs models because they are governed by a conformal fixed point in the ultraviolet but are chirally broken in the infrared. In this work we use lattice field theory calculations with domain wall fermions to investigate a system with four light and six heavy flavors. We demonstrate how a nearby conformal fixed point affects the properties of the four light flavors that exhibit chiral symmetry breaking in the infrared. Specifically we describe hyperscaling of dimensionful physical quantities and determine the corresponding anomalous mass dimension. We obtain ym=1+γ=1.47(5)y_m=1+\gamma^*= 1.47(5) suggesting that Nf=10N_f=10 lies inside the conformal window. Comparing the low energy spectrum to predictions of dilaton chiral perturbation theory, we observe excellent agreement which supports the expectation that the 4+6 mass-split system exhibits near-conformal dynamics with a relatively light 0++0^{++} isosinglet scalar

    Near-conformal dynamics in a chirally broken system

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    Composite Higgs models must exhibit very different dynamics from quantum chromodynamics (QCD) regardless whether they describe the Higgs boson as a dilatonlike state or a pseudo-Nambu-Goldstone boson. Large separation of scales and large anomalous dimensions are frequently desired by phenom- enological models. Mass-split systems are well-suited for composite Higgs models because they are governed by a conformal fixed point in the ultraviolet but are chirally broken in the infrared. In this work we use lattice field theory calculations with domain wall fermions to investigate a system with four light and six heavy flavors. We demonstrate how a nearby conformal fixed point affects the properties of the four light flavors that exhibit chiral symmetry breaking in the infrared. Specifically we describe hyperscaling of dimensionful physical quantities and determine the corresponding anomalous mass dimension. We obtain ym = 1 + γ* = 1.47(5) suggesting that Nf = 10 lies inside the conformal window. Comparing the low energy spectrum to predictions of dilaton chiral perturbation theory, we observe excellent agreement which supports the expectation that the 4+6 mass-split system exhibits near-conformal dynamics with a relatively light 0þþ isosinglet scalar
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