4,359 research outputs found
Classification of Southern Ocean krill and icefish echoes using random forests
Acknowledgements The authors thank the crews, fishers, and scientists who conducted the various surveys from which data were obtained. This work was supported by the Government of South Georgia and South Sandwich Islands. Additional logistical support provided by The South Atlantic Environmental Research Institute, with thanks to Paul Brickle. PF receives funding from the MASTS pooling initiative (TheMarine Alliance for Science and Technology for Scotland), and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. SF is funded by the Natural Environment Research Council, and data were provided from the British Antarctic Survey Ecosystems Long-term Monitoring and Surveys programme as part of the BAS Polar Science for Planet Earth Programme. The authors also thank the anonymous referees for their helpful suggestions on an earlier version of this manuscript.Peer reviewedPostprin
Resistance and adaptation to criminal identity: using secondary analysis to evaluate classic studies of crime and deviance
'Qualitative Daten bieten reichhaltige Einsichten in die soziale Welt, sei es in alleiniger Anwendung oder im Tandem mit statistischer Analyse. Allerdings ist die Erhebung und Auswertung qualitativer Daten mit hohen Kosten verbunden. Ferner ist allgemein bekannt, dass nur ein Teil der so aufwĂ€ndig erhobenen Daten letztlich Gegenstand der Auswertung und Veröffentlichung wird. Die SekundĂ€ranalyse ist in der quantitativen Forschung bereits eine gut etablierte Methode und gewinnt auch fĂŒr die Anwendung auf qualitative Daten an WertschĂ€tzung. Eine besondere Rolle spielt sie im Zusammenhang mit Forschung zu sensiblen Themen und/oder schwer zugĂ€nglichen Populationen, wie in dem vorliegenden Beispiel erlĂ€utert wird. Dieser Artikel leistet einen Beitrag zur Diskussion des Potenzials und der Grenzen der SekundĂ€ranalyse qualitativer Daten, indem er die Ergebnisse einer SekundĂ€ranalyse einer klassischen Studie zur Soziologie des GefĂ€ngnislebens - Cohen und Taylors Forschung zu Langzeit-Inhaftierung von MĂ€nnern in Hochsicherheitsverwahrung - berichtet. Auf der Grundlage der Nutzung archivierter Daten der Originalstudie betrachtet der Beitrag Cohen und Taylors Originalanalyse erneut und zeigt UnterstĂŒtzung fĂŒr eine alternative Konzeptionalisierung. Unter den diskutierten methodologischen Aspekten befinden sich die Wiederherstellung des Kontextes der originĂ€ren Feldarbeit sowie die Rolle der SekundĂ€ranalyse innerhalb eines kumulativen Ansatzes von Wissensproduktion.' (Autorenreferat)'Qualitative data offer rich insights into the social world, whether alone or in tandem with statistical analysis. However, qualitative data are costly to collect and analyse. Moreover, it is a commonplace that only a portion of the data so labouriously collected is the subject of final analysis and publication. Secondary analysis is a well-established method in quantitative research and is raising its profile in application to qualitative data. It has a particular part to play when research is on sensitive topics and/or hard-to-reach populations, as in the example considered here. This article contributes to discussion of the potential and constraints of secondary analysis of qualitative data by reporting the outcome of the secondary analysis of a key study in the sociology of prison life, Cohen and Taylor's research on the long-term imprisonment of men in maximum security. The article re-visits Cohen and Taylor's original analysis and demonstrates support for an alternative, if complementary, conceptualisation, using archived data from the original study. Among the methodological issues discussed are the recovery of the context of the original fieldwork and the role of secondary analysis in an incremental approach to knowledge production.' (author's abstract)
Errata for Folksongs from the Maritimes
Toneset and solfa errata for Kaye Pottie and vernon Ellis\u27 Folksongs of the Maritimes (1992)
Reporting and dealing with missing quality of life data in RCTs : has the picture changed in the last decade?
Peer reviewedPublisher PD
Second-line antiretroviral therapy in a workplace and community-based treatment programme in South Africa: determinants of virological outcome.
: Background: As antiretroviral treatment (ART) programmes in resource-limited settings mature, more patients are experiencing virological failure. Without resistance testing, deciding who should switch to second-line ART can be difficult. The consequences for second-line outcomes are unclear. In a workplace- and community-based multi-site programme, with 6-monthly virological monitoring, we describe outcomes and predictors of viral suppression on second-line, protease inhibitor-based ART.Methods: We used prospectively collected clinic data from patients commencing first-line ART between 1/1/03 and 31/12/08 to construct a study cohort of patients switched to second-line ART in the presence of a viral load (VL) ?400 copies/ml. Predictors of VL<400 copies/ml within 15 months of switch were assessed using modified Poisson regression to estimate risk ratios.Results: 205 workplace patients (91.7% male; median age 43 yrs) and 212 community patients (38.7% male; median age 36 yrs) switched regimens. At switch compared to community patients, workplace patients had a longer duration of viraemia, higher VL, lower CD4 count, and higher reported non-adherence on first-line ART. Non-adherence was the reported reason for switching in a higher proportion of workplace patients. Following switch, 48.3% (workplace) and 72.0% (community) achieved VL<400, with non-adherence (17.9% vs. 1.4%) and virological rebound (35.6% vs. 13.2% with available measures) reported more commonly in the workplace programme. In adjusted analysis of the workplace programme, lower switch VL and younger age were associated with VL<400. In the community programme, shorter duration of viraemia, higher CD4 count and transfers into programme on ART were associated with VL<400.Conclusion: High levels of viral suppression on second-line ART can be, but are not always, achieved in multi-site treatment programmes with both individual- and programme-level factors influencing outcomes. Strategies to support both healthcare workers and patients during this switch period need to be evaluated; sub-optimal adherence, particularly in the workplace programme must be addressed
Inhibition of vicariously learned fear in children using positive modeling and prior exposure
One of the challenges to conditioning models of fear acquisition is to explain how different individuals can experience similar learning events and only some of them subsequently develop fear. Understanding factors moderating the impact of learning events on fear acquisition is key to understanding the etiology and prevention of fear in childhood. This study investigates these moderators in the context of vicarious (observational) learning. Two experiments tested predictions that the acquisition or inhibition of fear via vicarious learning is driven by associative learning mechanisms similar to direct conditioning. In Experiment 1, 3 groups of children aged 7 to 9 years received 1 of 3 inhibitive information interventions psychoeducation, factual information, or no information (control)âprior to taking part in a vicarious fear learning procedure. In Experiment 2, 3 groups of children aged 7 to 10 years received 1 of 3 observational learning interventionsâpositive modeling (immunization), observational familiarity (latent inhibition), or no prevention (control)â before vicarious fear learning. Results indicated that observationally delivered manipulations inhibited vicarious fear learning, while preventions presented via written information did not. These findings confirm that vicarious learning shares some of the characteristics of direct conditioning and can explain why not all individuals will develop fear following a vicarious learning event. They also suggest that the modality of inhibitive learning is important and should match the fear learning pathway for increased chances of inhibition. Finally, the results demonstrate that positive modeling is likely to be a particularly effective method for preventing fear-related observational learning in children
Additional value of EUS in oesophageal cancer patients staged N0 on PET/CT: validation of a prognostic model
Background
Lymph node metastases are a major prognostic indicator in oesophageal cancer. Radiological staging largely influences treatment decisions and is becoming more reliant on PET and CT. However, the sensitivity of these modalities is suboptimal and is known to under-stage disease. The primary aim of this study was to validate a published prognostic model in oesophageal cancer patients staged N0 with PET/CT, which showed that EUS nodal status was an independent predictor of survival. The secondary aim was to assess the prognostic significance of pathological lymph node metastases in this cohort.
Methods
An independent validation cohort included 139 consecutive patients from a regional upper gastrointestinal cancer network staged N0 with PET/CT between 1st January 2013 and 31st June 2015. Replicating the original study, two Cox regression models were produced: one included EUS T-stage and EUS N-stage, and one included EUS T-stage and EUS N0 versus N+. The primary outcome of the prognostic model was overall survival (OS). KaplanâMeier analysis assessed differences in OS between pathological node-negative (pN0) and node-positive (pN+) groups. A p value of <â0.05 was considered statistically significant.
Results
The mean OS of the validation cohort was 29.8 months (95% CI 27.1â35.2). EUS T-stage was significantly and independently associated with OS in both models (pâ=â0.011 and pâ=â0.012, respectively). EUS N-stage and EUS N0 versus N+ were not significantly associated with OS (pâ=â0.553 and pâ=â0.359, respectively). There was a significant difference in OS between pN0 and pN+ groups (Ï2 13.315, df 1, pâ<â0.001).
Conclusion
Lymph node metastases have a significant detrimental effect on OS. This validation study did not replicate the results of the developed prognostic model but the continued benefit of EUS in patients staged N0 with PET/CT was demonstrated. EUS remains a valuable component of a multi-modality approach to oesophageal cancer staging
Changes and demands in the higher education sector are increasingly making advanced degree medical physics programs nonviable and the profession will have to develop a new model for delivering such education
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141195/1/mp12645_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141195/2/mp12645.pd
New Developments in Spin Labels for Pulsed Dipolar EPR
Spin labelling is a chemical technique that enables the integration of a molecule containing an unpaired electron into another framework for study. Given the need to understand the structure, dynamics, and conformational changes of biomacromolecules, spin labelling provides a relatively non-intrusive technique and has certain advantages over X-ray crystallography; which requires high quality crystals. The technique relies on the design of binding probes that target a functional group, for example, the thiol group of a cysteine residue within a protein. The unpaired electron is typically supplied through a nitroxide radical and sterically shielded to preserve stability. Pulsed electron paramagnetic resonance (EPR) techniques allow small magnetic couplings to be measured (e.g., <50 MHz) providing information on single label probes or the dipolar coupling between multiple labels. In particular, distances between spin labels pairs can be derived which has led to many protein/enzymes and nucleotides being studied. Here, we summarise recent examples of spin labels used for pulse EPR that serve to illustrate the contribution of chemistry to advancing discoveries in this field
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