5,732 research outputs found
Post-Reproductive Pacific Salmon, Oncorhynchus spp., as a Major Nutrient Source for Large Aggregations of Gulls, Larus spp.
On the Pacific coast of North America, the most abundant vertebrate visitors to estuaries and rivers during salmon migration are gulls, yet the utilization of salmon nutrients by these scavengers, and subsequent ecological impacts are not well documented. On two forested watersheds on the central coast of British Columbia, we tracked gull abundance during the spawning period for two consecutive years, and estimated consumption of post-reproductive salmon carcasses and eggs, as well as guano production. At Clatse River, gulls (Larus glaucescens, L. argentatus, L. thayerii, L. californicus, L. canus, L. philadelphia) consumed 13-26% of total salmon carcass biomass and 29-36% of all salmon eggs deposited in the system. At Neekas River, gulls consumed 11-19% of salmon carcass biomass and 7-18% of total salmon eggs. Local guano production over the 60-day period ranged from 600 kg to 1190 kg at Clatse and from 1200 kg to 2100 kg at Neekas River, and was distributed to marine, estuarine, freshwater and riparian habitats. The large aggregations of gulls and subsequent nutrient cycling observed on our study watersheds may represent a once widespread phenomenon that is now largely reduced due to recent declines in salmon populations
Regional coastal food risk assessment for a tidally dominant, natural coastal setting: North Norfolk, southern North Sea
A Coastal Risk Assessment Framework (CRAF) provides two levels of coastal risk and vulnerability assessment, by combining information on the spatially variable hazard and exposure. In Phase 1, areas of greatest risk or `hotspots' are identified. In Phase 2, these hotspots are then analysed in greater detail to identify both direct and indirect extreme event impacts. This approach was applied to the barrier coastline of North Norfolk, eastern England. The CRAF identified high risk coastal hotspots on the basis of both hazard impacts (swash regime (tide + surge + wave runup) and overwash/terrestrial inundation regimes) from a 1 in 115 year return period storm and a range of land use, infrastructure, economic and social vulnerability indicators. Hazard extents and hazard severity, in some locations modified by the presence of intertidal saltmarsh, were calculated for 45, 1-2 km wide sections along the topographically complex coast. When combined with ve exposure indicators, eight hotspots were identified along the 45 km long frontage. In a 2nd phase, two of these hotspots, one a chain of small villages (Brancaster/Brancaster Staithe/Burnham Deepdale) and one a small town (Wells-next-the-Sea), were compared in more detail using a suite of coastal inundation and impact assessment models to determine both direct and indirect impacts. Hazards at this higher resolution were calculated using the 1D process-based XBeach model and the 2D LISFLOOD inundation model. Vulnerability to the hazards was calculated using the INDRA (Integrated Disruption Assessment) model with comparison of the two hotspots through the use of a Multi Criteria Analysis (MCA). The selection of hazard hotspots and comparison of hotspots using these techniques allows areas at greatest risk to be identified, of vital importance for coastal management and resource allocation
Synthetic sites for transcription termination and a functional comparison with tryptophan operon termination sites in vitro.
Determination of phototropism by UV-B radiation
UV-B phototropism in etiolated Arabidopsis seedlings has only been shown recently and needs further exploration. Here we elaborate on how to generate a customized setup with a unilateral UV-B light source, the required plant materials, different growth substrates, and a framework for data analysis
Genetic background influences tumour development in heterozygous Men1 knockout mice
Multiple endocrine neoplasia type 1 (MEN1), an autosomal dominant disorder caused by MEN1 germline mutations, is characterised by parathyroid, pancreatic and pituitary tumours. MEN1 mutations also cause familial isolated primary hyperparathyroidism (FIHP), a milder condition causing hyperparathyroidism only. Identical mutations can cause either MEN1 or FIHP in different families, thereby implicating a role for genetic modifiers in altering phenotypic expression of tumours. We therefore investigated the effects of genetic background and potential for genetic modifiers on tumour development in adult Men1+/- mice, which develop tumours of the parathyroids, pancreatic islets, anterior pituitary, adrenal cortex and gonads, that had been backcrossed to generate C57BL/6 and 129S6/SvEv congenic strains. A total of 275 Men1+/- mice, aged 5–26 months were macroscopically studied, and this revealed that genetic background significantly influenced the development of pituitary, adrenal and ovarian tumours, which occurred in mice over 12 months of age and more frequently in C57BL/6 females, 129S6/SvEv males and 129S6/SvEv females, respectively. Moreover, pituitary and adrenal tumours developed earlier, in C57BL/6 males and 129S6/SvEv females, respectively, and pancreatic and testicular tumours developed earlier in 129S6/SvEv males. Furthermore, glucagon-positive staining pancreatic tumours occurred more frequently in 129S6/SvEv Men1+/- mice. Whole genome sequence analysis of 129S6/SvEv and C57BL/6 Men1+/- mice revealed >54,000 different variants in >300 genes. These included, Coq7, Dmpk, Ccne2, Kras, Wnt2b, Il3ra and Tnfrsf10a, and qRT-PCR analysis revealed that Kras was significantly higher in pituitaries of male 129S6/SvEv mice. Thus, our results demonstrate that Kras and other genes could represent possible genetic modifiers of Men1
Interprofessional Collaboration and Health Sciences Libraries
UNC Health Affairs Collaborative: Mission - provide strategic leadership from multiple perspectives to improve individual and population health by way of effective and efficient innovation in education, scholarship and service. Goal - provide the infrastructure that will facilitate an opportunity for every student in health affairs at UNC to engage in an interprofessional experience from which they will emerge with appreciation and respect for thoughtful collaborative practice
Lack of Pathology in a Triple Transgenic Mouse Model of Alzheimer’s Disease after Overexpression of the Anti-Apoptotic Protein Bcl-2
Alzheimer’s disease (AD) is characterized by the accumulation of plaques containing ß-amyloid (Aß) and neurofibrillary tangles (NFTs) consisting of modified tau. Although Aß deposition is thought to precede the formation of NFTs in AD, the molecular steps connecting these two pathologies is not known. Previous studies have suggested that caspase activation plays an important role in promoting the pathology associated with AD. To further understand the contribution of caspases in disease progression, a triple transgenic Alzheimer’s mouse model overexpressing the anti-apoptotic protein Bcl-2 was generated. Here we show that overexpression of Bcl-2 limited caspase-9 activation and reduced the caspase cleavage of tau. Moreover, overexpression of Bcl-2 attenuated the processing of APP (amyloid precursor protein) and tau and reduced the number of NFTs and extracellular deposits of Aß associated with these animals. In addition, overexpression of Bcl-2 in 3xTg-AD mice improved place recognition memory. These findings suggest that the activation of apoptotic pathways maybe an early event in AD and contributes to the pathological processes that promote the disease mechanisms underlying AD
Do MOOCs encourage corporate social responsibility or are they simply a marketing opportunity?
This paper explores institutional drivers for developing MOOCs by juxtaposing them against the original drivers for generating MOOCs: to offer open access education. However, the original impetus for MOOC development may be shifting towards a business oriented model. Therefore, instead of contributing to corporate social responsibility and inclusivity agendas facilitating open access to education, MOOCs are akin to an institution's shop window allowing the pseudo 'purchaser' the opportunity to glimpse behind the scenes. Hence, we ask: are MOOCs merely a sophisticated form of window dressing, showing pseudo 'purchasers' what institutions want them to see enticing them to purchase more lucrative products? Notwithstanding the motivation for developing MOOCs participants must first access them. Therefore the paper examines what MOOCs actually offer participants who are likely to access them and concludes by examining how MOOCs can be developed to facilitate better completion rates and encourage wider participation from hard to access groups
Aerodynamics of aero-engine installation
This paper describes current progress in the development of methods to assess aero-engine airframe installation effects. The aerodynamic characteristics of isolated intakes, a typical transonic transport aircraft as well as a combination of a through-flow nacelle and aircraft configuration have been evaluated. The validation task for an isolated engine nacelle is carried out with concern for the accuracy in the assessment of intake performance descriptors such as mass flow capture ratio and drag rise Mach number. The necessary mesh and modelling requirements to simulate the nacelle aerodynamics are determined. Furthermore, the validation of the numerical model for the aircraft is performed as an extension of work that has been carried out under previous drag prediction research programmes. The validation of the aircraft model has been extended to include the geometry with through flow nacelles. Finally, the assessment of the mutual impact of the through flow nacelle and aircraft aerodynamics was performed. The drag and lift coefficient breakdown has been presented in order to identify the component sources of the drag associated with the engine installation. The paper concludes with an assessment of installation drag for through-flow nacelles and the determination of aerodynamic interference between the nacelle and the aircraft
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