223 research outputs found

    Reprint of: High prey-predator size ratios and unselective feeding in copepods: A seasonal comparison of five species with contrasting feeding modes

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    There has been an upsurge of interest in trait-based approaches to zooplankton, modelling the seasonal changes in the feeding modes of zooplankton in relation to phytoplankton traits such as size or motility. We examined this link at two English Channel plankton monitoring sites south of Plymouth (L4 and E1). At L4 there was a general transition from diatoms in spring to motile microplankton in summer and autumn, but this was not mirrored in the succession of copepod feeding traits; for example the ambushing Oithona similis dominated during the spring diatom bloom. At nearby E1 we measured seasonality of food and grazers, finding strong variation between 2014 and 2015 but overall low mesozooplankton biomass (median 4.5 mg C m−3). We also made a seasonal grazing study of five copepods with contrasting feeding modes (Calanus helgolandicus, Centropages typicus, Acartia clausi, Pseudocalanus elongatus and Oithona similis), counting the larger prey items from the natural seston. All species of copepod fed on all food types and differences between their diets were only subtle; the overriding driver of diet was the composition of the prey field. Even the smaller copepods fed on copepod nauplii at significant rates, supporting previous suggestions of the importance of intra-guild predation. All copepods, including O. similis, were capable of tackling extremely long (>500 µm) diatom chains at clearance rates comparable to those on ciliates. Maximum observed prey:predator length ratios ranged from 0.12 (C. helgolandicus) up to 0.52 (O. similis). Unselective feeding behaviour and the ability to remove highly elongated cells have implications for how copepod feeding is represented in ecological and biogeochemical models

    Assessing Anti-HCMV Cell Mediated Immune Responses in Transplant Recipients and Healthy Controls Using a Novel Functional Assay

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    HCMV infection, reinfection or reactivation occurs in 60% of untreated solid organ transplant (SOT) recipients. Current clinical approaches to HCMV management include pre-emptive and prophylactic antiviral treatment strategies. The introduction of immune monitoring to better stratify patients at risk of viraemia and HCMV mediated disease could improve clinical management. Current approaches quantify T cell IFNγ responses specific for predominantly IE and pp65 proteins ex vivo, as a proxy for functional control of HCMV in vivo. However, these approaches have only a limited predictive ability. We measured the IFNγ T cell responses to an expanded panel of overlapping peptide pools specific for immunodominant HCMV proteins IE1/2, pp65, pp71, gB, UL144, and US3 in a cohort of D+R– kidney transplant recipients in a longitudinal analysis. Even with this increased antigen diversity, the results show that while all patients had detectable T cell responses, this did not correlate with control of HCMV replication in some. We wished to develop an assay that could directly measure anti-HCMV cell-mediated immunity. We evaluated three approaches, stimulation of PBMC with (i) whole HCMV lysate or (ii) a defined panel of immunodominant HCMV peptides, or (iii) fully autologous infected cells co-cultured with PBMC or isolated CD8+ T cells or NK cells. Stimulation with HCMV lysate often generated non-specific antiviral responses while stimulation with immunodominant HCMV peptide pools produced responses which were not necessarily antiviral despite strong IFNγ production. We demonstrated that IFNγ was only a minor component of secreted antiviral activity. Finally, we used an antiviral assay system to measure the effect of whole PBMC, and isolated CD8+ T cells and NK cells to control HCMV in infected autologous dermal fibroblasts. The results show that both PBMC and especially CD8+ T cells from HCMV seropositive donors have highly specific antiviral activity against HCMV. In addition, we were able to show that NK cells were also antiviral, but the level of this control was highly variable between donors and not dependant on HCMV seropositivity. Using this approach, we show that non-viraemic D+R+ SOT recipients had significant and specific antiviral activity against HCMV

    Can big data solve a big problem? Reporting the obesity data landscape in line with the Foresight obesity system map.

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    BACKGROUND: Obesity research at a population level is multifaceted and complex. This has been characterised in the UK by the Foresight obesity systems map, identifying over 100 variables, across seven domain areas which are thought to influence energy balance, and subsequent obesity. Availability of data to consider the whole obesity system is traditionally lacking. However, in an era of big data, new possibilities are emerging. Understanding what data are available can be the first challenge, followed by an inconsistency in data reporting to enable adequate use in the obesity context. In this study we map data sources against the Foresight obesity system map domains and nodes and develop a framework to report big data for obesity research. Opportunities and challenges associated with this new data approach to whole systems obesity research are discussed. METHODS: Expert opinion from the ESRC Strategic Network for Obesity was harnessed in order to develop a data source reporting framework for obesity research. The framework was then tested on a range of data sources. In order to assess availability of data sources relevant to obesity research, a data mapping exercise against the Foresight obesity systems map domains and nodes was carried out. RESULTS: A reporting framework was developed to recommend the reporting of key information in line with these headings: Background; Elements; Exemplars; Content; Ownership; Aggregation; Sharing; Temporality (BEE-COAST). The new BEE-COAST framework was successfully applied to eight exemplar data sources from the UK. 80% coverage of the Foresight obesity systems map is possible using a wide range of big data sources. The remaining 20% were primarily biological measurements often captured by more traditional laboratory based research. CONCLUSIONS: Big data offer great potential across many domains of obesity research and need to be leveraged in conjunction with traditional data for societal benefit and health promotion

    Performance Measures Based on How Adults With Cancer Feel and Function: Stakeholder Recommendations and Feasibility Testing in Six Cancer Centers

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    PURPOSE Patient-reported outcome measures (PROMs) that assess how patients feel and function have potential for evaluating quality of care. Stakeholder recommendations for PRO-based performance measures (PMs) were elicited, and feasibility testing was conducted at six cancer centers. METHODS Interviews were conducted with 124 stakeholders to determine priority symptoms and risk adjustment variables for PRO-PMs and perceived acceptability. Stakeholders included patients and advocates, caregivers, clinicians, administrators, and thought leaders. Feasibility testing was conducted in six cancer centers. Patients completed PROMs at home 5-15 days into a chemotherapy cycle. Feasibility was operationalized as 75 75% completed PROMs and 75% patient acceptability. RESULTS Stakeholder priority PRO-PMs for systemic therapy were GI symptoms (diarrhea, constipation, nausea, vomiting), depression/anxiety, pain, insomnia, fatigue, dyspnea, physical function, and neuropathy. Recommended risk adjusters included demographics, insurance type, cancer type, comorbidities, emetic risk, and difficulty paying bills. In feasibility testing, 653 patients enrolled (approximately 110 per site), and 607 (93%) completed PROMs, which indicated high feasibility for home collection. The majority of patients (470 of 607; 77%) completed PROMs without a reminder call, and 137 (23%) of 607 completed them after a reminder call. Most patients (72%) completed PROMs through web, 17% paper, or 2% interactive voice response (automated call that verbally asked patient questions). For acceptability, . 95% of patients found PROM items to be easy to understand and complete. CONCLUSION Clinicians, patients, and other stakeholders agree that PMs that are based on how patients feel and function would be an important addition to quality measurement. This study also shows that PRO-PMs can be feasibly captured at home during systemic therapy and are acceptable to patients. PRO-PMs may add value to the portfolio of PMs as oncology transitions from fee-for-service payment models to performance-based care that emphasizes outcome measures

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Does Lateral Transmission Obscure Inheritance in Hunter-Gatherer Languages?

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    In recent years, linguists have begun to increasingly rely on quantitative phylogenetic approaches to examine language evolution. Some linguists have questioned the suitability of phylogenetic approaches on the grounds that linguistic evolution is largely reticulate due to extensive lateral transmission, or borrowing, among languages. The problem may be particularly pronounced in hunter-gatherer languages, where the conventional wisdom among many linguists is that lexical borrowing rates are so high that tree building approaches cannot provide meaningful insights into evolutionary processes. However, this claim has never been systematically evaluated, in large part because suitable data were unavailable. In addition, little is known about the subsistence, demographic, ecological, and social factors that might mediate variation in rates of borrowing among languages. Here, we evaluate these claims with a large sample of hunter-gatherer languages from three regions around the world. In this study, a list of 204 basic vocabulary items was collected for 122 hunter-gatherer and small-scale cultivator languages from three ecologically diverse case study areas: northern Australia, northwest Amazonia, and California and the Great Basin. Words were rigorously coded for etymological (inheritance) status, and loan rates were calculated. Loan rate variability was examined with respect to language area, subsistence mode, and population size, density, and mobility; these results were then compared to the sample of 41 primarily agriculturalist languages in [1]. Though loan levels varied both within and among regions, they were generally low in all regions (mean 5.06%, median 2.49%, and SD 7.56), despite substantial demographic, ecological, and social variation. Amazonian levels were uniformly very low, with no language exhibiting more than 4%. Rates were low but more variable in the other two study regions, in part because of several outlier languages where rates of borrowing were especially high. High mobility, prestige asymmetries, and language shift may contribute to the high rates in these outliers. No support was found for claims that hunter-gatherer languages borrow more than agriculturalist languages. These results debunk the myth of high borrowing in hunter-gatherer languages and suggest that the evolution of these languages is governed by the same type of rules as those operating in large-scale agriculturalist speech communities. The results also show that local factors are likely to be more critical than general processes in determining high (or low) loan rates

    Plant-made vaccines in support of the Millennium Development Goals

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    Vaccines are one of the most successful public health achievements of the last century. Systematic immunisation programs have reduced the burden of infectious diseases on a global scale. However, there are limitations to the current technology, which often requires costly infrastructure and long lead times for production. Furthermore, the requirement to keep vaccines within the cold-chain throughout manufacture, transport and storage is often impractical and prohibitively expensive in developing countries—the very regions where vaccines are most needed. In contrast, plant-made vaccines (PMVs) can be produced at a lower cost using basic greenhouse agricultural methods, and do not need to be kept within such narrow temperature ranges. This increases the feasibility of developing countries producing vaccines locally at a small-scale to target the specific needs of the region. Additionally, the ability of plant-production technologies to rapidly produce large quantities of strain-specific vaccine demonstrates their potential use in combating pandemics. PMVs are a proven technology that has the potential to play an important role in increasing global health, both in the context of the 2015 Millennium Development Goals and beyond

    Mental health first aid for Indigenous Australians: using Delphi consensus studies to develop guidelines for culturally appropriate responses to mental health problems

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    <p>Abstract</p> <p>Background</p> <p>Ethnic minority groups are under-represented in mental health care services because of barriers such as poor mental health literacy. In 2007, the Mental Health First Aid (MHFA) program implemented a cultural adaptation of its first aid course to improve the capacity of Indigenous Australians to recognise and respond to mental health issues within their own communities. It became apparent that the content of this training would be improved by the development of best practice guidelines. This research aimed to develop culturally appropriate guidelines for providing first aid to an Australian Aboriginal or Torres Strait Islander person who is experiencing a mental health crisis or developing a mental illness.</p> <p>Methods</p> <p>A panel of Australian Aboriginal people who are experts in Aboriginal mental health, participated in six independent Delphi studies investigating depression, psychosis, suicidal thoughts and behaviours, deliberate self-injury, trauma and loss, and cultural considerations. The panel varied in size across the studies, from 20-24 participants. Panellists were presented with statements about possible first aid actions via online questionnaires and were encouraged to suggest additional actions not covered by the survey content. Statements were accepted for inclusion in a guideline if they were endorsed by ≥ 90% of panellists as <it>essential </it>or <it>important</it>. Each study developed one guideline from the outcomes of three Delphi questionnaire rounds. At the end of the six Delphi studies, participants were asked to give feedback on the value of the project and their participation experience.</p> <p>Results</p> <p>From a total of 1,016 statements shown to the panel of experts, 536 statements were endorsed (94 for depression, 151 for psychosis, 52 for suicidal thoughts and behaviours, 53 for deliberate self-injury, 155 for trauma and loss, and 31 for cultural considerations). The methodology and the guidelines themselves were found to be useful and appropriate by the panellists.</p> <p>Conclusion</p> <p>Aboriginal mental health experts were able to reach consensus about culturally appropriate first aid for mental illness. The Delphi consensus method could be useful more generally for consulting Indigenous peoples about culturally appropriate best practice in mental health services.</p
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