416 research outputs found
Sea-Level Rise Practitioner Workshop Report: Leading Practices and Current Challenges
Seas are rising, and so is action in coastal communities to prepare. The uncertain timing of rising seas, difficulties evaluating long-term rise while facing more immediate causes of flooding such as typhoons and fluvial flooding, and simply the threat of permanent inundation of coastal zones settled for hundreds or thousands of years presents unprecedented challenges. As in all sectors impacted by anthropogenic climate change, working with others facing novel challenges to share progress and difficulties, collaborate regionally, and build competence and confidence in finding solutions can be invaluable
Mating failure shapes the patterns of sperm precedence in an insect
Funding: University of St Andrews PhD Apprenticeship (VLB); Laidlaw Scholarship Programme (DB).Estimates of last male sperm precedence (P2) are often used to infer mechanisms of sperm competition, a form of post-copulatory sexual selection. However, high levels of mating failure (i.e. copulations resulting in no offspring) in a population can lead to misinterpretations of sperm competition mechanisms. Through simulations, García-González (2004) illustrated how mating failure could cause bimodal distributions of paternity with peaks at P2 = 0 and 1, under a random sperm mixing mechanism. Here, we demonstrate this effect empirically with the seed bug Lygaeus simulans, a species known to exhibit high levels of mating failure (40–60%), using a morphological marker to estimate paternity. Contrary to previous findings in a sister species, we did not find strong evidence for last male sperm precedence. There was a tendency towards last male precedence (P2 = 0.58) but within the expected range for random sperm mixing. Instead, P2 was highly variable, with a bimodal distribution, as predicted by García-González (2004). After taking mating failure into account, the strongest driver of paternity outcome was copulation duration. Furthermore, we found evidence that mating failure could partly be a female-associated trait. Some doubly-mated females were more likely to produce no offspring or produce offspring from two different sires than expected by chance. Therefore, some females are more prone to experience mating failure than others, a result that mirrors an earlier result in male L. simulans. Our results confirm that mating failure needs to be considered when interrogating mechanisms of post-copulatory sexual selection.Publisher PDFPeer reviewe
Culture of airway epithelial cells from neonates sampled within 48-hours of birth
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The effects of wet wipe pollution on the Asian clam, Corbicula fluminea (Mollusca: Bivalvia) in the River Thames, London
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Intentions to Move from Homelessness to Social Inclusion: The Role of Participation Beliefs, Attitudes and Prior Behaviour
A key aim of homelessness services is not only to ensure that homeless people attain a secure home, but that this is a pathway to wider social inclusion. However, relatively little is known about the psychological elements that are essential for homeless people to engage with these pathways, nor whether these elements combine in ways that are predictable from previous research. In the present work, we examined both demographic and behavioural precursors, and contemporaneous psychological predictors,of a set of 49 homeless men’s intentions to engage with a programme to move them toward long-term housing and social inclusion. Contrary to predictions based on subjective utility and rational choice theories, we found that normative pressure and did not directly predict the men’s intentions. Instead, we found that intentions were predicted by their attitudes towards the services, and their specific beliefs about the benefits of particular courses of action (efficacy beliefs), and to a more restricted extent their experience (socio demographics); and in those with high prior service use histories, only participatory beliefs guided future service use intentions. These findings suggest that it is important to focus on intentions as a highly relevant outcome of interventions, because beliefs about interventions can break the link between past behaviour or habitual service use and future service use. Such interventions may be particularly effective if they focus on the evaluative and efficacy-related aspects of behaviour over time and better understand the benefits the men evaluated the services as offering them
Geochemical Controls On Naturally-Occurring Radionuclides In Private Well Water Of The North Carolina Piedmont
We present detailed results of natural contaminant occurrence for about 150 wells on the Piedmont of North Carolina, mostly drilled into granite, gneiss, metasedimentary rocks, and metavolcanic rocks. Our results suggest that the overall occurrence of radionuclides in water is highest where rocks containing elevated levels of uranium and thorium, such as granite, are present. However, localized spots exhibit high radionuclides in water in other rock types as well
Concise Review: Cell Therapy for Critical Limb Ischemia: An Integrated Review of Preclinical and Clinical Studies
Critical limb ischemia (CLI), the most severe form of peripheral artery disease, is characterized by pain at rest and non-healing ulcers in the lower extremities. For patients with CLI, where the extent of atherosclerotic artery occlusion is too severe for surgical bypass or percutaneous interventions, limb amputation remains the only treatment option. Thus, cell-based therapy to restore perfusion and promote wound healing in patients with CLI is under intense investigation. Despite promising preclinical studies in animal models, transplantation of bone marrow (BM)-derived cell populations in patients with CLI has shown limited benefit preventing limb amputation. Early trials injected heterogenous mononuclear cells containing a low frequency of cells with pro-vascular regenerative functions. Most trials transferred autologous cells damaged by chronic disease that demonstrated poor survival in the ischemic environment and impaired function conferred by atherosclerotic or diabetic co-morbidities. Finally, recent preclinical studies suggest optimized blood vessel formation may require paracrine and/or structural contributions from multiple progenitor cell lineages, angiocrine-secretory myeloid cells derived from hematopoietic progenitor cells, tubule-forming endothelial cells generated by circulating or vessel-resident endothelial precursors, and vessel-stabilizing perivascular cells derived from mesenchymal stem cells. Understanding how stem cells co-ordinate the myriad of cells and signals required for stable revascularization remains the key to translating the potential of stem cells into curative therapies for CLI. Thus, combination delivery of multiple cell types within supportive bioengineered matricies may represent a new direction to improve cell therapy strategies for CLI. Stem Cells 2018;36:161–171
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