598 research outputs found
The Natural and Cultural Landscape of Greene County, Virginia
One hundred and fifty five miles west of the Atlantic coast a sign welcomes travelers to Greene County, Virginia. The natural landscape of the region is defined by the transition between the flattish Piedmont plateau and natural wall to the west known as the Blue Ridge Mountains. The lushly forested mountain slopes and nutrient rich upland soils have long provided economic and cultural foundations, but indiscriminate land use now offers multiple threats to the rural heritage of the County. Overtimbered mountain slopes and multiple pollutants have threatened the immune systems of the forest, leaving them vulnerable to natural pests. Soils which once provided the foundation for an agrarian culture were often depleted, and now serve as the nutrients for expansive real estate development. The common threads that once helped to define the community are disappearing in the wake of rampant population growth. While a native community struggles to find its voice amongst an influx of new settlers, the natural resources of the region are diminishing.
This paper surveys the natural and human history of the region. It is the authors intent to identify that which threatens the natural and cultural landscape of Greene County. The paper also considers the success or failure of intervention strategies aimed at solving the identified problems, while recording the response of community members to such threats
Crossflow : A framework for distributed mining of software repositories
Large-scale software repository mining typically requires substantial storage and computational resources, and often involves a large number of calls to (rate-limited) APIs such as those of GitHub and StackOverflow. This creates a growing need for distributed execution of repository mining programs to which remote collaborators can contribute computational and storage resources, as well as API quotas (ideally without sharing API access tokens or credentials). In this paper we introduce Crossflow, a novel framework for building distributed repository mining programs. We demonstrate how Crossflow can delegate mining jobs to remote workers and cache their results, and how workers can implement advanced behaviour such as load balancing and rejecting jobs they cannot perform (e.g. due to lack of space, credentials for a specific API)
Exchanges of carbon and nitrogen between tidal freshwater wetlands and adjacent tributaries : a final report
Tidal freshwater marshes are hypothesized to export materials and energy that support primary and secondary production in estuaries, yet there are few data available to test this hypothesis. A major objective of our study was to measure net exchange of carbon between marsh and atmosphere to determine whether biogenic carbon inputs are in excess of those required to produce observed biomass, satisfy the measured accretion rate, and keep pace with the historical rate of sea level rise. To determine whether the marsh exports materials and energy we measured exchanges of nutrients between marsh sediments and overlying water and of nutrients, total suspended solids, and chlorophyll a between the adjacent tidal creek and river. Studies were performed in Sweet Hall Marsh, a National Estuarine Research Reserve, located on the Pamunkey River in Virginia. A gaseous carbon flux model was developed to calculate annual net CO2 and CI4 fluxes between the atmosphere and marsh. In addition, we performed seasonal measurements of macrophyte diversity and biomass, sediment microalgal biomass, standing stocks of porewater nutrients, %C and %N in sediments and macrophytes, and sediment gross mineralization and nitrification. Based upon two years of measurements of net ecosystem metabolism, the marsh is net heterotrophic. Estimates of sediment respiration based on net sediment metabolism greatly underestimated the true respiration rate. When gross N-mineralization, expressed in units of carbon, was used as a surrogate for sediment respiration, net autotrophic fixation accounted for estimated biomass production. A process-based carbon mass balance model for Sweet Hall Marsh was constructed to determine whether calculations of carbon exchange using the gaseous carbon flux model and results of exchange studies were reasonable and to guide future research at Sweet Hall Marsh. Results of mass balance analysis showed that inputs and exports of carbon to or from the marsh are reasonably in balance. While additional information on sediment and chlorophyll exchanges would strengthen our model, it appears that on an annual basis Sweet Hall Marsh imports sediments and exports chlorophyll. In addition, the marsh is a sink for N03- throughout the year. N}4+ produced by organic matter mineralization appears to be removed by coupled nitrification - denitrification so that there is little, if any, export of dissolved inorganic nitrogen from the marsh. These conclusions indicate that tidal freshwater marshes may export materials (chlorophyll) to adjacent waters, but the ultimate fate of these materials and their effects on estuarine primary and secondary production are still unknown
Genetic variants in eleven central and peripheral chemoreceptor genes in sudden infant death syndrome
Background: Sudden infant death syndrome (SIDS) is still one of the leading causes of postnatal infant death in developed countries. The occurrence of SIDS is described by a multifactorial etiology that involves the respiratory control system including chemoreception. It is still unclear whether genetic variants in genes involved in respiratory chemoreception might play a role in SIDS.
Methods: The exome data of 155 SIDS cases were screened for variants within 11 genes described in chemoreception. Pathogenicity of variants was assigned based on the assessment of variant types and in silico protein predictions according to the current recommendations of the American College of Medical Genetics and Genomics.
Results: Potential pathogenic variants in genes encoding proteins involved in respiratory chemoreception could be identified in 5 (3%) SIDS cases. Two of the variants (R137S/A188S) were found in the KNCJ16 gene, which encodes for the potassium channel Kir5.1, presumably involved in central chemoreception. Electrophysiologic analysis of these KCNJ16 variants revealed a loss-of-function for the R137S variant but no obvious impairment for the A188S variant.
Conclusions: Genetic variants in genes involved in respiratory chemoreception may be a risk factor in a fraction of SIDS cases and may thereby contribute to the multifactorial etiology of SIDS.
Impact: What is the key message of your article? Gene variants encoding proteins involved in respiratory chemoreception may play a role in a minority of SIDS cases. What does it add to the existing literature? Although impaired respiratory chemoreception has been suggested as an important risk factor for SIDS, genetic variants in single genes seem to play a minor role. What is the impact? This study supports previous findings, which indicate that genetic variants in single genes involved in respiratory control do not have a dominant role in SIDS
The Diverse Roles of γδ T Cells in Cancer: From Rapid Immunity to Aggressive Lymphoma
γδ T cells are unique players in shaping immune responses, lying at the intersection between innate and adaptive immunity. Unlike conventional αβ T cells, γδ T cells largely populate non-lymphoid peripheral tissues, demonstrating tissue specificity, and they respond to ligands in an MHC-independent manner. γδ T cells display rapid activation and effector functions, with a capacity for cytotoxic anti-tumour responses and production of inflammatory cytokines such as IFN-γ or IL-17. Their rapid cytotoxic nature makes them attractive cells for use in anti-cancer immunotherapies. However, upon transformation, γδ T cells can give rise to highly aggressive lymphomas. These rare malignancies often display poor patient survival, and no curative therapies exist. In this review, we discuss the diverse roles of γδ T cells in immune surveillance and response, with a particular focus on cancer immunity. We summarise the intriguing dichotomy between pro- and anti-tumour functions of γδ T cells in solid and haematological cancers, highlighting the key subsets involved. Finally, we discuss potential drivers of γδ T-cell transformation, summarising the main γδ T-cell lymphoma/leukaemia entities, their clinical features, recent advances in mapping their molecular and genomic landscapes, current treatment strategies and potential future targeting options
The Diverse Roles of γδ T Cells in Cancer: From Rapid Immunity to Aggressive Lymphoma
γδ T cells are unique players in shaping immune responses, lying at the intersection between innate and adaptive immunity. Unlike conventional αβ T cells, γδ T cells largely populate non-lymphoid peripheral tissues, demonstrating tissue specificity, and they respond to ligands in an MHC-independent manner. γδ T cells display rapid activation and effector functions, with a capacity for cytotoxic anti-tumour responses and production of inflammatory cytokines such as IFN-γ or IL-17. Their rapid cytotoxic nature makes them attractive cells for use in anti-cancer immunotherapies. However, upon transformation, γδ T cells can give rise to highly aggressive lymphomas. These rare malignancies often display poor patient survival, and no curative therapies exist. In this review, we discuss the diverse roles of γδ T cells in immune surveillance and response, with a particular focus on cancer immunity. We summarise the intriguing dichotomy between pro- and anti-tumour functions of γδ T cells in solid and haematological cancers, highlighting the key subsets involved. Finally, we discuss potential drivers of γδ T-cell transformation, summarising the main γδ T-cell lymphoma/leukaemia entities, their clinical features, recent advances in mapping their molecular and genomic landscapes, current treatment strategies and potential future targeting options
The Diverse Roles of γδ T Cells in Cancer: From Rapid Immunity to Aggressive Lymphoma
γδ T cells are unique players in shaping immune responses, lying at the intersection between innate and adaptive immunity. Unlike conventional αβ T cells, γδ T cells largely populate non-lymphoid peripheral tissues, demonstrating tissue specificity, and they respond to ligands in an MHC-independent manner. γδ T cells display rapid activation and effector functions, with a capacity for cytotoxic anti-tumour responses and production of inflammatory cytokines such as IFN-γ or IL-17. Their rapid cytotoxic nature makes them attractive cells for use in anti-cancer immunotherapies. However, upon transformation, γδ T cells can give rise to highly aggressive lymphomas. These rare malignancies often display poor patient survival, and no curative therapies exist. In this review, we discuss the diverse roles of γδ T cells in immune surveillance and response, with a particular focus on cancer immunity. We summarise the intriguing dichotomy between pro- and anti-tumour functions of γδ T cells in solid and haematological cancers, highlighting the key subsets involved. Finally, we discuss potential drivers of γδ T-cell transformation, summarising the main γδ T-cell lymphoma/leukaemia entities, their clinical features, recent advances in mapping their molecular and genomic landscapes, current treatment strategies and potential future targeting options
Reusable textual styles for domain-specific modeling languages
Domain-specific languages enable concise and precise formalization of domain concepts and promote direct employment by domain experts. Therefore, syntactic constructs are introduced to empower users to associate concepts and relationships with visual textual symbols. Model-based language engineering facilitates the description of concepts and relationships in an abstract manner. However, concrete representations are commonly attached to abstract domain representations, such as annotations in metamodels, or directly encoded into language grammar and thus introduce redundancy between metamodel elements and grammar elements. In this work we propose an approach that enables autonomous development and maintenance of domain concepts and textual language notations in a distinctive and metamodel-agnostic manner by employing style models containing grammar rule templates and injection-based property selection. We provide an implementation and showcase the proposed notationspecification language in a comparison with state of the art practices during the creation of notations for an executable domain-specific modeling language based on the Eclipse Modeling Framework and Xtext
Multidisciplinary investigation of the pit circuit at Durrington Walls, UK
ISBN: 9782753585874.– Comprehensive geophysical assessment of huge pits; ERT, GPR, mag and EM. – Novel approach to testing and interpreting pits via coring. – Largest pit circuit confirmed in both the Stonehenge landscape and the UK.Publisher PDFPeer reviewe
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