1,461 research outputs found
Population trajectory and stressors of Acropora palmata sites in the Florida Keys
The decline of elkhorn coral, Acropora palmata, has been ongoing for decades, but the causes of decline and the resulting population status continue to be topics of study. Past efforts to categorize stressors have ranged from spatially and/or temporally focused efforts that detect local stressors but may miss broader patterns to meta-analyses that identify large-scale trends but may not account for finer-scale variability. We here conduct an analysis of sites surveyed across five years (2010-2015) and much of the Florida Reef Tract in order to look at large-scale patterns while also accounting for site, habitat, seasonal, and annual variability. Through fate-tracking across nine sites, we assess trends in total tissue amount, fragmentation and fragment survival, and prevalence and severity of stressors. Acute stressors included severe bleaching events and spikes in disease prevalence, while chronic stressors were dominated by corallivorous snail predation. Four of nine survey sites experienced near total declines in population over the survey period, but the timing and cause of each differed, even among sites within a few kilometers of each other. There were notable differences in the prevalence and severity of stressors between forereef and backreef sites. We conclude that generalizing the population trajectories and stressors of A. palmata can misrepresent the conditions at individual sites. We also conclude that the forereef and backreef environments examined here differ in their stressors, and that habitat should be identified as a variable of interest in assessing A. palmata trajectories. We use this information to speculate that the remaining population of A. palmata within Dry Tortugas National Park may have survived as a result of its unique backreef geography
Ultra-light Axions: Degeneracies with Massive Neutrinos and Forecasts for Future Cosmological Observations
A generic prediction of string theory is the existence of many axion fields.
It has recently been argued that many of these fields should be light and, like
the well known QCD axion, lead to observable cosmological consequences. In this
paper we study in detail the effect of the so-called string axiverse on large
scale structure, focusing on the morphology and evolution of density
perturbations, anisotropies in the cosmic microwave background and weak
gravitational lensing of distant galaxies. We quantify specific effects that
will arise from the presence of the axionic fields and highlight possible
degeneracies that may arise in the presence of massive neutrinos. We take
particular care understanding the different physical effects and scales that
come into play. We then forecast how the string axiverse may be constrained and
show that with a combination of different observations, it should be possible
to detect a fraction of ultralight axions to dark matter of a few percent.Comment: 24 pages, 16 figures, this version: corrected typos, some comments
added, matches published versio
The ABCD of usability testing
We introduce a methodology for tracking and auditing feedback, errors and suggestions for software packages. This short paper describes how we innovate on the evaluation mechanism, introducing an (Antecedent, Barrier, Consequence and Development) ABCD form, embedded within an eParticipation platform to enable end users to easily report on any usability issues. This methodology will be utilised to improve the STEP cloud eParticipation platform (part of the current STEP Horizon2020 project http://step4youth.eu. The platform is currently being piloted in real life contexts, with the participation of public authorities that are integrating the eParticipation platform into their regular decision-making practices. The project is involving young people, through engagement and motivation strategies and giving them a voice in Environmental decision making at the local level. The pilot evaluation aims to demonstrate how open engagement needs to be embedded within public sector processes and the usability methodology reported here will help to identify the key barriers for wide scale deployment of the platform
Assessing the outcomes of participatory research: protocol for identifying, selecting, appraising and synthesizing the literature for realist review
<p>Abstract</p> <p>Background</p> <p>Participatory Research (PR) entails the co-governance of research by academic researchers and end-users. End-users are those who are affected by issues under study (<it>e.g.</it>, community groups or populations affected by illness), or those positioned to act on the knowledge generated by research (<it>e.g.</it>, clinicians, community leaders, health managers, patients, and policy makers). Systematic reviews assessing the generalizable benefits of PR must address: the diversity of research topics, methods, and intervention designs that involve a PR approach; varying degrees of end-user involvement in research co-governance, both within and between projects; and the complexity of outcomes arising from long-term partnerships.</p> <p>Methods</p> <p>We addressed the above mentioned challenges by adapting realist review methodology to PR assessment, specifically by developing inductively-driven identification, selection, appraisal, and synthesis procedures. This approach allowed us to address the non-uniformity and complexity of the PR literature. Each stage of the review involved two independent reviewers and followed a reproducible, systematic coding and retention procedure. Retained studies were completed participatory health interventions, demonstrated high levels of participation by non-academic stakeholders (<it>i.e.</it>, excluding studies in which end-users were not involved in co-governing throughout the stages of research) and contained detailed descriptions of the participatory process and context. Retained sets are being mapped and analyzed using realist review methods.</p> <p>Results</p> <p>The librarian-guided search string yielded 7,167 citations. A total of 594 citations were retained after the identification process. Eighty-three papers remained after selection. Principle Investigators (PIs) were contacted to solicit all companion papers. Twenty-three sets of papers (23 PR studies), comprising 276 publications, passed appraisal and are being synthesized using realist review methods.</p> <p>Discussion</p> <p>The systematic and stage-based procedure addressed challenges to PR assessment and generated our robust understanding of complex and heterogeneous PR practices. To date, realist reviews have focussed on evaluations of relatively uniform interventions. In contrast our PR search yielded a wide diversity of partnerships and research topics. We therefore developed tools to achieve conceptual clarity on the PR field, as a beneficial precursor to our theoretically-driven synthesis using realist methods. Findings from the ongoing review will be provided in forthcoming publications.</p
Current-Use Pesticides in New Zealand Streams: Comparing Results From Grab Samples and Three Types of Passive Samplers
New Zealand uses more than a ton of pesticides each year; many of these are mobile, relatively persistent, and can make their way into waterways. While considerable effort goes into monitoring nutrients in agricultural streams and programs exist to monitor pesticides in groundwater, very little is known about pesticide detection frequencies, concentrations, or their potential impacts in New Zealand streams. We used the ‘Polar Organic Chemical Integrative Sampler’ (POCIS) approach and grab water sampling to survey pesticide concentrations in 36 agricultural streams in Waikato, Canterbury, Otago and Southland during a period of stable stream flows in Austral summer 2017/18. We employed a new approach for calculating site-specific POCIS sampling rates. We also tested two novel passive samplers designed to reduce the effects of hydrodynamic conditions on sampling rates: the ‘Organic-Diffusive Gradients in Thin Films’ (o-DGT) aquatic passive sampler and microporous polyethylene tubes (MPTs) filled with Strata-X sorbent. Multiple pesticides were found at most sites; two or more were detected at 78% of sites, three or more at 69% of sites, and four or more at 39% of sites. Chlorpyrifos concentrations were the highest, with a maximum concentration of 180 ng/L. Concentrations of the other pesticides were generally below 20 ng/L. Mean concentrations of individual pesticides were not correlated with in-stream nutrient concentrations. The majority of pesticides were detected most frequently in POCIS, presumably due to its higher sampling rate and the relatively low concentrations of these pesticides. In contrast, chlorpyrifos was most frequently detected in grab samples. Chlorpyrifos concentrations at two sites were above the 21-day chronic ‘No Observable Effect Concentration’ (NOEC) values for fish and another two sites had concentrations greater than 50% of the NOEC. Otherwise, concentrations were well-below NOEC values, but close to the New Zealand Environmental Exposure Limits in several cases
Cysteine-524 is not the only residue involved in the formation of disulphide-bonded dimers of the insulin receptor
Follow-up plasma apolipoprotein E levels in the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing (AIBL) cohort
Introduction: Alzheimer's disease (AD) is a growing socioeconomic problem worldwide. Early diagnosis and prevention of this devastating disease have become a research priority. Consequently, the identification of clinically significant and sensitive blood biomarkers for its early detection is very important. Apolipoprotein E (APOE) is a well-known and established genetic risk factor for late-onset AD; however, the impact of the protein level on AD risk is unclear. We assessed the utility of plasma ApoE protein as a potential biomarker of AD in the large, well-characterised Australian Imaging, Biomarkers and Lifestyle Study of Ageing (AIBL) cohort.
Methods: Total plasma ApoE levels were measured at 18-month follow-up using a commercial bead-based enzyme-linked immunosorbent assay: the Luminex xMAP human apolipoprotein kit. ApoE levels were then analysed between clinical classifications (healthy controls, mild cognitive impairment (MCI) and AD) and correlated with the data available from the AIBL cohort, including but not limited to APOE genotype and cerebral amyloid burden.
Results: A significant decrease in ApoE levels was found in the AD group compared with the healthy controls. These results validate previously published ApoE protein levels at baseline obtained using different methodology. ApoE protein levels were also significantly affected, depending on APOE genotypes, with ε2/ε2 having the highest protein levels and ε4/ε4 having the lowest. Plasma ApoE levels were significantly negatively correlated with cerebral amyloid burden as measured by neuroimaging.
Conclusions: ApoE is decreased in individuals with AD compared with healthy controls at 18-month follow-up, and this trend is consistent with our results published at baseline. The influence of APOE genotype and sex on the protein levels are also explored. It is clear that ApoE is a strong player in the aetiology of this disease at both the protein and genetic levels
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