1,286 research outputs found

    A taxonomic guide to the mysids of the South Atlantic Bight.

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    Following the examination of extensive collections from the National Museum of Natural History (NMNH), the Southeastern Regional Taxonomic Center (SERTC), and other regional institutions, 18 species of the family Mysidae are recognized and described from the South Atlantic Bight (Cape Lookout, North Carolina to Cape Canaveral, Florida). This report includes synonymies of previous records, as well as new species distribution records. Previous regional accounts of Metamysidopsis munda and Metamysidopsis mexicana are attributed to Metamysidopsis swifti. New regional records are established for Amathimysis brattegardi, Heteromysis beetoni, and Siriella thompsonii. Two other species tentatively identified as Amathimysis sp. (nr. serrata) and Mysidopsis sp. (cf. mortenseni) may represent new taxa. Neobathymysis renoculata is included and discussed as a potential regional species. An illustrated key to the species currently known from the South Atlantic Bight is presented. Relevant taxonomic, distributional, and ecological information is also included for each species. (PDF file contains 45 pages.

    Difference algebraic geometry: Morphisms of difference schemes with an exceptional property.

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    PhD ThesesIn this thesis we generalise the theory of exceptional covers of varieties to the context of difference algebraic geometry. We formulate the notion of difference exceptional covers and prove a difference exceptionality criterion analogous to the classical situation. We also obtain a Galois correspondence for difference ring extensions in the style of Borceux- Janelidze. Along the way we explore the background of exceptional varieties, Grothendieck’s Galois categories and discuss a proof of the classical exceptionality criterion. An overview of difference algebraic geometry is given, motivated by the work of Tomaˇsi´

    From field to shore: Policy improvements to better protect ecosystem and human health from poultry wastes in Virginia

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    Commercial poultry production is a large industry with economic importance in Virginia. However, mismanagement of manures and wastes generated from the poultry industry can be a serious threat to ecosystem and human health. Primarily, there is a concern about nutrient pollution related to runoff and infiltration of poultry wastes. High nutrient loading can cause groundwater contamination, eutrophication, and harmful algal blooms (HABs). Additional concerns include metals, antibiotics, and pesticides that can be found in poultry wastes. To determine existing threats to ecosystem and human health from the poultry industry, Virginia policies regulating the industry are reviewed and their strengths and weaknesses are identified. These policies are compared to Maryland state policies to further determine strengths and weaknesses. Potential policy recommendations to improve regulation are offered to a stakeholder panel and final recommendations are provided at the end of this document. Recommendations include improved nutrient tracking, improved litter transportation tracking, offering safe transportation guidelines, improved application guidelines, and standardized nutrient testing

    Adjusting tropical marine water quality guideline values for elevated ocean temperatures

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    Increased frequency of summer heatwaves and poor water quality are two of the most prevalent and severe pressures faced by coral reefs. While these pressures often co-occur, their potential risks to tropical marine species are usually considered independently. Here, we extended the application of multisubstance-Potentially Affected Fraction (ms-PAF) to a nonchemical stressor, elevated sea surface temperature. We then applied this method to calculate climate-Adjusted water quality guideline values (GVs) for two reference toxicants, copper and the herbicide diuron, for tropical marine species. First, we developed a species sensitivity distribution (SSD) for thermal stress based on published experimental data for 41 tropical benthic marine species using methods adapted from water quality GV derivation. This enabled quantitative predictions of community effects as temperatures exceeded acclimation values. The resulting protective temperature values (PTx) were similar to temperatures known to initiate coral bleaching and are therefore relevant for application in multistressor risk assessments. The extended ms-PAF method enabled the adjustment of current water quality GVs to account for thermal stress events. This approach could be applied to other ecosystems and other non-contaminant stressors (e.g., sediment, low salinity, anoxia, and ocean acidification), offering an alternative approach for deriving environmental GVs, reporting and assessing the risk posed by multiple stressors

    Inequalities in the dental health needs and access to dental services among looked after children in Scotland: a population data linkage study

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    Background: There is limited evidence on the health needs and service access among children and young people who are looked after by the state. The aim of this study was to compare dental treatment needs and access to dental services (as an exemplar of wider health and well-being concerns) among children and young people who are looked after with the general child population. Methods: Population data linkage study utilising national datasets of social work referrals for ‘looked after’ placements, the Scottish census of children in local authority schools, and national health service’s dental health and service datasets. Results: 633 204 children in publicly funded schools in Scotland during the academic year 2011/2012, of whom 10 927 (1.7%) were known to be looked after during that or a previous year (from 2007–2008). The children in the looked after children (LAC) group were more likely to have urgent dental treatment need at 5 years of age: 23%vs10% (n=209/16533), adjusted (for age, sex and area socioeconomic deprivation) OR 2.65 (95% CI 2.30 to 3.05); were less likely to attend a dentist regularly: 51%vs63% (n=5519/388934), 0.55 (0.53 to 0.58) and more likely to have teeth extracted under general anaesthesia: 9%vs5% (n=967/30253), 1.91 (1.78 to 2.04). Conclusions: LAC are more likely to have dental treatment needs and less likely to access dental services even when accounting for sociodemographic factors. Greater efforts are required to integrate child social and healthcare for LAC and to develop preventive care pathways on entering and throughout their time in the care system

    A guide to the Thalassinidea (Crustacea: Malacostraca: Decapoda) of the South Atlantic Bight

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    Ghost shrimp and mud shrimp in the decapod infraorder Thalassinidea are ecologically important members of many benthic intertidal and shallow subtidal infaunal communities, largely due to the sediment filtration and mixing that result from their burrowing and feeding behavior. These activities considerably modify their immediate environment and have made these cryptic animals extremely interesting to scientists in terms of their behavior, ecology, and classification. Over 20 years ago, seven species of thalassinideans were known from the South Atlantic Bight (Cape Hatteras, NC to Cape Canaveral, FL). During this study, the examination of extensive collections from the National Museum of Natural History (NMNH), the Southeastern Regional Taxonomic Center (SERTC), and regional institutions, resulted in the identification of 14 species of thalassinideans currently known to occur within this region. The family Axiidae is represented by three species: Axius armatus, Calaxius jenneri, and Paraxiopsis gracilimana; the Callianassidae by six: Biffarius biformis, B. cf. fragilis, Callichirus major, Cheramus marginatus, Gilvossius setimanus, and Necallianassa berylae; the Calocarididae by two: Calocaris templemani and Acanthaxius hirsutimanus; and the families Laomediidae, Thomassiniidae, and Upogebiidae are each represented by one: Naushonia crangonoides, Crosniera wennerae, and Upogebia affinis, respectively. An illustrated key is presented for species level identification and supplemental notes on the ecology, distribution, and taxonomy of the species are provided.(PDF file contains 38 pages.

    Acts of Disruption in the Eighteenth-Century Archives: Cooperative Critical Bibliography and The Ballitore Project

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    This essay outlines a method of intersectional feminist book history that we call “cooperative critical bibliography,” a practice of engaging faculty and students at different ranks and at different institutions in the act of collaboratively transcribing and digitizing historical archives of understudied communities, often those that comprise the quotidian and domestic daily lives of everyday people. Cooperative critical bibliography’s non-hierarchical method centers the shared expertise and scholarship of students as they participate in broadening the accessibility of historical knowledge and revising standards of the historical literary canon through transcription, digitization, and shared reflection. By creating a pedagogical space that resituates learning and institutional connections non-hierarchically and elevates the material needs and experiential expertise of students to a crucial research skill, this practice offers an inclusive model of student-centered training that makes humanities and archival work welcoming for students of color, first-generation, and early career scholars: all groups who have been marginalized in university settings and in the fields of archival studies and book history. (In the issue section Rethinking Catalogs and Archives
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