266 research outputs found

    Understanding the Effect of Body Weight on Muscle Activity During Unilateral Hopping

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    Running can be described as a series of bilateral single-legged jumps and landings. Interestingly, single-legged jumps and landings are qualitatively more difficult unilaterally than bilaterally known as bilateral deficit syndrome (BDS). For example, one leg will produce less mechanical energy while jump squatting unilaterally than it would produce if both legs worked synchronously. The analysis of dynamic conditions under different levels of body weight support of the hopping movement may prove useful to understanding the bilateral deficit. Purpose: To compare muscle activity of the lower extremity during single-legged hopping at different levels of body weight support. Methods: The research study was recently approved by the Institutional Review Board and data collection has begun. Therefore, no data are presented in the abstract at this time. Subjects will be equipped with electromyography (EMG) leads to measure muscle activity of the rectus femoris, semitendinosus, medial gastrocnemius, and tibialis anterior. Subjects will be asked to perform 5 trials of hopping forwards at a preferred speed (PS) for 1 minute at varying levels of body weight (80%, 70%, 60%, 50%, 40%). EMG data of all four muscles will be compared across the separate body weight control conditions

    Bodily relations and reciprocity in the art of Sonia Khurana

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    This article explores the significance of the ‘somatic’ and ‘ontological turn’ in locating the radical politics articulated in the contemporary performance, installation, video and digital art practices of New Delhi-based artist, Sonia Khurana (b. 1968). Since the late 1990s Khurana has fashioned a range of artworks that require new sorts of reciprocal and embodied relations with their viewers. While this line of art practice suggests the need for a primarily philosophical mode of inquiry into an art of the body, such affective relations need to be historicised also in relation to a discursive field of ‘difference’ and public expectations about the artist’s ethnic, gendered and national identity. Thus, this intimate, visceral and emotional field of inter- and intra-action is a novel contribution to recent transdisciplinary perspectives on the gendered, social and sentient body, that in turn prompts a wider debate on the ethics of cultural commentary and art historiography

    Excess cardiovascular mortality associated with cold spells in the Czech Republic

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    <p>Abstract</p> <p>Background</p> <p>The association between cardiovascular mortality and winter cold spells was evaluated in the population of the Czech Republic over 21-yr period 1986–2006. No comprehensive study on cold-related mortality in central Europe has been carried out despite the fact that cold air invasions are more frequent and severe in this region than in western and southern Europe.</p> <p>Methods</p> <p>Cold spells were defined as periods of days on which air temperature does not exceed -3.5°C. Days on which mortality was affected by epidemics of influenza/acute respiratory infections were identified and omitted from the analysis. Excess cardiovascular mortality was determined after the long-term changes and the seasonal cycle in mortality had been removed. Excess mortality during and after cold spells was examined in individual age groups and genders.</p> <p>Results</p> <p>Cold spells were associated with positive mean excess cardiovascular mortality in all age groups (25–59, 60–69, 70–79 and 80+ years) and in both men and women. The relative mortality effects were most pronounced and most direct in middle-aged men (25–59 years), which contrasts with majority of studies on cold-related mortality in other regions. The estimated excess mortality during the severe cold spells in January 1987 (+274 cardiovascular deaths) is comparable to that attributed to the most severe heat wave in this region in 1994.</p> <p>Conclusion</p> <p>The results show that cold stress has a considerable impact on mortality in central Europe, representing a public health threat of an importance similar to heat waves. The elevated mortality risks in men aged 25–59 years may be related to occupational exposure of large numbers of men working outdoors in winter. Early warnings and preventive measures based on weather forecast and targeted on the susceptible parts of the population may help mitigate the effects of cold spells and save lives.</p

    Queen mandibular pheromone: questions that remain to be resolved

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    The discovery of ‘queen substance’, and the subsequent identification and synthesis of keycomponents of queen mandibular pheromone, has been of significant importance to beekeepers and to thebeekeeping industry. Fifty years on, there is greater appreciation of the importance and complexity of queenpheromones, but many mysteries remain about the mechanisms through which pheromones operate. Thediscovery of sex pheromone communication in moths occurred within the same time period, but in this case,intense pressure to find better means of pest management resulted in a remarkable focusing of research activityon understanding pheromone detection mechanisms and the central processing of pheromone signals in themoth. We can benefit from this work and here, studies on moths are used to highlight some of the gaps in ourknowledge of pheromone communication in bees. A better understanding of pheromone communication inhoney bees promises improved strategies for the successful management of these extraordinary animals

    Squaring the circle: a priority-setting method for evidence-based service development, reconciling research with multiple stakeholder views.

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    BACKGROUND: This study demonstrates a technique to aid the implementation of research findings through an example of improving services and self-management in longer-term depression. In common with other long-term conditions, policy in this field requires innovation to be undertaken in the context of a whole system of care, be cost-effective, evidence-based and to comply with national clinical guidelines. At the same time, successful service development must be acceptable to clinicians and service users and choices must be made within limited resources. This paper describes a novel way of resolving these competing requirements by reconciling different sources and types of evidence and systematically engaging multiple stakeholder views. METHODS: The study combined results from mathematical modelling of the care pathway, research evidence on effective interventions and findings from qualitative research with service users in a series of workshops to define, refine and select candidate service improvements. A final consensus-generating workshop used structured discussion and anonymised electronic voting. This was followed by an email survey to all stakeholders, to achieve a pre-defined criterion of consensus for six suggestions for implementation. RESULTS: An initial list of over 20 ideas was grouped into four main areas. At the final workshop, each idea was presented in person, visually and in writing to 40 people, who assigned themselves to one or more of five stakeholder groups: i) service users and carers, ii) clinicians, iii) managers, iv) commissioners and v) researchers. Many belonged to more than one group. After two rounds of voting, consensus was reached on seven ideas and one runner up. The survey then confirmed the top six ideas to be tested in practice. CONCLUSIONS: The method recruited and retained people with diverse experience and views within a health community and took account of a full range of evidence. It enabled a diverse group of stakeholders to travel together in a direction that converged with the messages coming out of the research and successfully yielded priorities for service improvement that met competing requirements

    Spiking Patterns and Their Functional Implications in the Antennal Lobe of the Tobacco Hornworm Manduca sexta

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    Bursting as well as tonic firing patterns have been described in various sensory systems. In the olfactory system, spontaneous bursts have been observed in neurons distributed across several synaptic levels, from the periphery, to the olfactory bulb (OB) and to the olfactory cortex. Several in vitro studies indicate that spontaneous firing patterns may be viewed as “fingerprints” of different types of neurons that exhibit distinct functions in the OB. It is still not known, however, if and how neuronal burstiness is correlated with the coding of natural olfactory stimuli. We thus conducted an in vivo study to probe this question in the OB equivalent structure of insects, the antennal lobe (AL) of the tobacco hornworm Manduca sexta. We found that in the moth's AL, both projection (output) neurons (PNs) and local interneurons (LNs) are spontaneously active, but PNs tend to produce spike bursts while LNs fire more regularly. In addition, we found that the burstiness of PNs is correlated with the strength of their responses to odor stimulation – the more bursting the stronger their responses to odors. Moreover, the burstiness of PNs was also positively correlated with the spontaneous firing rate of these neurons, and pharmacological reduction of bursting resulted in a decrease of the neurons' responsiveness. These results suggest that neuronal burstiness reflects a physiological state of these neurons that is directly linked to their response characteristics

    Interpreting and reporting ⁴⁰Ar/³⁹Ar geochronologic data

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    The ⁴⁰Ar/³⁹Ar dating method is among the most versatile of geochronometers, having the potential to date a broad variety of K-bearing materials spanning from the time of Earth’s formation into the historical realm. Measurements using modern noble-gas mass spectrometers are now producing ⁴⁰Ar/³⁹Ar dates with analytical uncertainties of ∼0.1%, thereby providing precise time constraints for a wide range of geologic and extraterrestrial processes. Analyses of increasingly smaller subsamples have revealed age dispersion in many materials, including some minerals used as neutron fluence monitors. Accordingly, interpretive strategies are evolving to address observed dispersion in dates from a single sample. Moreover, inferring a geologically meaningful “age” from a measured “date” or set of dates is dependent on the geological problem being addressed and the salient assumptions associated with each set of data. We highlight requirements for collateral information that will better constrain the interpretation of ⁴⁰Ar/³⁹Ar data sets, including those associated with single-crystal fusion analyses, incremental heating experiments, and in situ analyses of microsampled domains. To ensure the utility and viability of published results, we emphasize previous recommendations for reporting ⁴⁰Ar/³⁹Ar data and the related essential metadata, with the amendment that data conform to evolving standards of being findable, accessible, interoperable, and reusable (FAIR) by both humans and computers. Our examples provide guidance for the presentation and interpretation of ⁴⁰Ar/³⁹Ar dates to maximize their interdisciplinary usage, reproducibility, and longevity

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    Population genetic structure of Aedes polynesiensis in the Society Islands of French Polynesia: implications for control using a Wolbachia-based autocidal strategy

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    Abstract Background Aedes polynesiensis is the primary vector of Wuchereria bancrofti in the South Pacific and an important vector of dengue virus. An improved understanding of the mosquito population genetics is needed for insight into the population dynamics and dispersal, which can aid in understanding the epidemiology of disease transmission and control of the vector. In light of the potential release of a Wolbachia infected strain for vector control, our objectives were to investigate the microgeographical and temporal population genetic structure of A. polynesiensis within the Society Islands of French Polynesia, and to compare the genetic background of a laboratory strain intended for release into its population of origin. Methods A panel of eight microsatellite loci were used to genotype A. polynesiensis samples collected in French Polynesia from 2005-2008 and introgressed A. polynesiensis and Aedes riversi laboratory strains. Examination of genetic differentiation was performed using F-statistics, STRUCTURE, and an AMOVA. BAYESASS was used to estimate direction and rates of mosquito movement. Results FST values, AMOVA, and STRUCTURE analyses suggest low levels of intra-island differentiation from multiple collection sites on Tahiti, Raiatea, and Maupiti. Significant pair-wise FST values translate to relatively minor levels of inter-island genetic differentiation between more isolated islands and little differentiation between islands with greater commercial traffic (i.e., Tahiti, Raiatea, and Moorea). STRUCTURE analyses also indicate two population groups across the Society Islands, and the genetic makeup of Wolbachia infected strains intended for release is similar to that of wild-type populations from its island of origin, and unlike that of A. riversi. Conclusions The observed panmictic population on Tahiti, Raiatea, and Moorea is consistent with hypothesized gene flow occurring between islands that have relatively high levels of air and maritime traffic, compared to that of the more isolated Maupiti and Tahaa. Gene flow and potential mosquito movement is discussed in relation to trials of applied autocidal strategies.</p

    Validity of willingness to pay measures under preference uncertainty

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    This paper is part of the project ACCEPT, which is funded by the German Federal Ministry for Education and Research (grant number 01LA1112A). The publication of this article was funded by the Open Access fund of the Leibniz Association. All data is available on the project homepage (https://www.ifw-kiel.de/forschung/umwelt/projekte/accept) and from Figshare (https://dx.doi.org/10.6084/m9.figshare.3113050.v1).Recent studies in the marketing literature developed a new method for eliciting willingness to pay (WTP) with an open-ended elicitation format: the Range-WTP method. In contrast to the traditional approach of eliciting WTP as a single value (Point-WTP), Range-WTP explicitly allows for preference uncertainty in responses. The aim of this paper is to apply Range-WTP to the domain of contingent valuation and to test for its theoretical validity and robustness in comparison to the Point-WTP. Using data from two novel large-scale surveys on the perception of solar radiation management (SRM), a little-known technique for counteracting climate change, we compare the performance of both methods in the field. In addition to the theoretical validity (i.e. the degree to which WTP values are consistent with theoretical expectations), we analyse the test-retest reliability and stability of our results over time. Our evidence suggests that the Range-WTP method clearly outperforms the Point-WTP method.Publisher PDFPeer reviewe
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