37 research outputs found

    The Student View on Online Peer Reviews

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    Peer review is used as an effective quality assurance measure in many contexts, including science, business, programming or education. In education, several studies confirmed the positive effects of peer reviewing on student learning. Based on recent research concerning the role of media in the peer review process this study investigates how students perceive the process, content and effects of peer reviews. We also analyze students' opinions on different modes of peer reviewing activities, e.g. online vs. face-to-face reviewing. In the context of a computer science course on scientific writing, these research questions were addressed by administering an online questionnaire (n=38) and analysis using quantitative and qualitative methods. Results indicate that students value the peer review activity, take peer reviews seriously and provide comprehensive and constructive reviews. Findings also show that students prefer written online reviews with the possibility of oral follow-up questions to reviewers

    Screening for Mutations Related to Atovaquone/ Proguanil Resistance in Treatment Failures and Other Imported Isolates of Plasmodium falciparum in Europe

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    Background. Two single-point mutations of the Plasmodium falciparum cytochrome b gene (Tyr268Asn and Tyr268Ser) were recently reported in cases of atovaquone/proguanil (Malarone) treatment failure. However, little is known about the prevalence of codon-268 mutations and their quantitative association with treatment failure. Methods. We set out to assess the prevalence of codon-268 mutations in P. falciparum isolates imported into Europe and to quantify their association with atovaquone/proguanil treatment failure. Isolates of P. falciparum collected by the European Network on Imported Infectious Disease Surveillance between April 2000 and August 2003 were analyzed for codon-268 mutations, by use of polymerase chain reaction-restriction fragment-length polymorphism. Results. We successfully screened 504 samples for the presence of either Tyr268Ser or Tyr268Asn. One case of Ser268 and no cases of Asn268 were detected. Therefore, we can be 95% confident that the prevalence of Ser268 in the European patient pool does not exceed 0.96% and that Asn268 is less frequent than 0.77%. In 58 patients treated with atovaquone/proguanil, Tyr268Ser was present in 1 of 5 patients with treatment failure but in 0 of 53 successfully treated patients. Conclusions. Tyr268Ser seems to be a sufficient, but not a necessary, cause for atovaquone/proguanil treatment failure. The prevalence of both codon-268 mutations is currently unlikely to be >1% in the European patient poo

    Advances in Molecular Quantum Chemistry Contained in the Q-Chem 4 Program Package

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    A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of the comparative accuracy of modern density functionals for bonded and non-bonded interactions, tests of attenuated second order Mþller–Plesset (MP2) methods for intermolecular interactions, a variety of parallel performance benchmarks, and tests of the accuracy of implicit solvation models. Some specific chemical examples include calculations on the strongly correlated Cr2 dimer, exploring zeolite-catalysed ethane dehydrogenation, energy decomposition analysis of a charged ter-molecular complex arising from glycerol photoionisation, and natural transition orbitals for a Frenkel exciton state in a nine-unit model of a self-assembling nanotube

    Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

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    BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

    DER EINSATZ VON ONLINE-PEER-REVIEWS ALS KOLLABORATIVE LERNFORM

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    Peer-Reviews leisten einen wertvollen Beitrag fĂŒr die QualitĂ€tssicherung in Unternehmen sowie im Wissenschaftsbetrieb und haben auf Grund zahlreicher positiver Effekte fĂŒr Studierende und Lehrende als didaktische Methode auch in der Wissensvermittlung Einzug gehalten. Im Kontext aktueller Forschung ĂŒber die Rolle neuer Medien im Peer-Review-Prozess analysiert die vorliegende Studie, ob und welchen Mehrwert Online-Peer-Reviews verglichen mit Face-to-Face- Peer-Reviews aus der Sicht der Studierenden bieten können. Im Rahmen einer universitĂ€ren Lehrveranstaltung wurde diese Fragestellung mit Hilfe eines Online-Fragebogens unter Einbezug qualitativer und quantitativer Methoden untersucht (n=38). Ergebnisse zeigen, dass Studierende Online-Peer-Reviews mit RĂŒckfragemöglichkeit prĂ€ferieren, da das Feedback schriftlich festgehalten wird und damit MissverstĂ€ndnisse durch mĂŒndlichen Austausch beseitigt werden können. FĂŒr positiv empfundene Peer-Reviews ist nicht nur die Kombination der eingesetzten Medien wichtig, sondern auch deren Reihenfolge und Gewichtung im Review-Prozess

    Geographical miss during intracoronary irradiation: impact on restenosis and determination of required safety margin length

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    AbstractObjectivesThe goal of this study was to evaluate the incidence and effects of underdosage of injured segments during intracoronary irradiation and to define the minimal length of safety margin required to avoid mismatched source placement.BackgroundUnderdosage of injured segments due to misplacement of active source has been suggested as the underlying mechanism for the occurrence of edge restenosis.MethodsBaseline angiograms of 112 vessels in 109 patients with in-stent restenosis undergoing coronary reintervention followed by intracoronary irradiation (192Ir: Checkmate, Cordis, Miami, Florida; 32P: Gallileo, Guidant, Houston, Texas; 90Sr/Y: Beta-Cath, Novoste, Norcross, Georgia) were analyzed. The distances between the outermost injury and outermost end of “reference isodose length” (RIL), defined as a segment with ≄90% of reference dose at 1 mm vessel wall depth, were measured. “Safety margin” was defined as the distance between the outermost injury and outermost end of the RIL, “geographical miss” (GM) as a complete injured segment not being covered by the RIL, and “restenosis” as the percent diameter stenosis >50%.ResultsBaseline angiographic analysis was performed for 224 edges in 112 vessels. Geographical miss was found in 46 (20.6%) edges. The incidence of target lesion restenosis within the 78 vessels with available follow-up was 43.3% for patients with GM versus 14.9% for patients with no GM (p = 0.005). Analysis of various injured segments exposed highest restenosis rates in injured segments with negligible irradiation (27.8%) in comparison with injured segments with dose fall-off (16.7%) or injured segments with full-dose irradiation (7.7%) (p = 0.006). Receiver operating curve analysis revealed a safety margin of 10 mm required per vessel (i.e., 5-mm safety margin/edge) to achieve 95% specificity of GM.ConclusionsGeographical miss is associated with a higher incidence of restenosis at the corresponding edges. Restenosis was more pronounced in injured segments with negligible irradiation than in injured segments at the dose fall-off zones. We recommend a safety margin of 10 mm per vessel to minimize GM
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