2,470 research outputs found
Am I Not a Woman and a Sister?:Konstruktionen von Weiblichkeit und kolonialer Sklaverei im Diskurs britischer Abolitionistinnen
Britische Abolitionistinnen trugen mit ihren literarischen BeitrĂ€gen entscheidend zur Abschaffung der Sklaverei in England bei. Sie entwickelten gezielte argumentative Strategien und formulierten ihr Anliegen aus einer spezifisch weiblichen Perspektive. So bot die Anti-Sklaverei-Debatte eine Möglichkeit, zugleich Frauenrechte einzuklagen. Als Frauen waren diese Schriftstellerinnen Opfer dominanter patriarchaler Machtstrukturen, die sie kritisch hinterfragten; als weiĂe EuropĂ€erinnen waren sie Angehörige derjenigen imperialistischen Macht, von der die koloniale UnterdrĂŒckung ausging und somit oftmals loyale Komplizinnen mĂ€nnlicher Unterwerfungsspolitik. Unter dem Einfluss revolutionĂ€rer Ereignisse in Frankreich und Saint-Domingue wandelte sich die Geschlechterdebatte und zugleich der weibliche Abolitionismusdiskurs in England. Erkenntnisleitend bei dieser Untersuchung ist ein interdisziplinĂ€rer Zugang, der AnsĂ€tze der Geschlechterstudien und der postkolonialen Theorie verbindet
Moving Knowledge Acquisition From the Lecture Hall to the Student Home: A Prospective Intervention Study.
BACKGROUND: Podcasts are popular with medical students, but the impact of podcast use on learning outcomes in undergraduate medical education has not been studied in detail. OBJECTIVE: Our aim was to assess the impact of podcasts accompanied by quiz questions and lecture attendance on short- and medium-term knowledge retention. METHODS: Students enrolled for a cardio-respiratory teaching module were asked to prepare for 10 specific lectures by watching podcasts and submitting answers to related quiz questions before attending live lectures. Performance on the same questions was assessed in a surprise test and a retention test. RESULTS: Watching podcasts and submitting answers to quiz questions (versus no podcast/quiz use) was associated with significantly better test performance in all items in the surprise test and 7 items in the retention test. Lecture attendance (versus no attendance) was associated with higher test performance in 3 items and 1 item, respectively. In a linear regression analysis adjusted for age, gender, and overall performance levels, both podcast/quiz use and lecture attendance were significant predictors of student performance. However, the variance explained by podcast/quiz use was greater than the variance explained by lecture attendance in the surprise test (38.7% vs. 2.2%) and retention test (19.1% vs. 4.0%). CONCLUSIONS: When used in conjunction with quiz questions, podcasts have the potential to foster knowledge acquisition and retention over and above the effect of live lectures
A two-species continuum model for aeolian sand transport
Starting from the physics on the grain scale, we develop a simple continuum
description of aeolian sand transport. Beyond popular mean-field models, but
without sacrificing their computational efficiency, it accounts for both
dominant grain populations, hopping (or "saltating") and creeping (or
"reptating") grains. The predicted stationary sand transport rate is in
excellent agreement with wind tunnel experiments simulating wind conditions
ranging from the onset of saltation to storms. Our closed set of equations thus
provides an analytically tractable, numerically precise, and computationally
efficient starting point for applications addressing a wealth of phenomena from
dune formation to dust emission.Comment: 23 pages, 9 figure
Test-enhanced learning of clinical reasoning: a crossover randomised trial
CONTEXT: Clinical reasoning is an essential skill, the foundations of which should be acquired during undergraduate medical education. Student performance in clinical reasoning can be assessed using key feature examinations. However, within a paradigm of test-enhanced learning, such examinations may also be used to enhance long-term retention of procedural knowledge relevant to clinical reasoning. OBJECTIVES: This study tested the hypothesis that repeated testing with key feature questions is more effective than repeated case-based learning in fostering clinical reasoning. METHODS: In this randomised crossover trial, Year 4 medical students attended 10 weekly computer-based seminars during which patient case histories covering general medical conditions were displayed. The presentation format was switched between groups every week. In the control condition, students studied long case narratives. The intervention condition used the same content but augmented case presentation with a sequence of key feature questions. Using a within-subjects design, student performance on intervention and control items was assessed at 13 weeks (exit examination) and 9 months (retention test) after the first day of term. RESULTS: A total of 87 of 124 eligible students provided complete data for the longitudinal analysis (response rate: 70.2%). In the retention test, mean ± standard deviation student scores on intervention items were significantly higher than those on control items (56.0 ± 25.8% versus 48.8 ± 24.7%; p < 0.001). The results remained unchanged after accounting for exposure time in a linear regression analysis that also adjusted for sex and general student performance levels. CONCLUSIONS: This is the first study to demonstrate an effect of test-enhanced learning on clinical reasoning as assessed with key feature questions. In this randomised trial, repeated testing was more effective than repeated case-based learning alone. Curricular implementation of longitudinal key feature testing may considerably enhance student learning outcomes in relevant aspects of clinical medicine
Slow breathing reduces sympathoexcitation in COPD
Neurohumoral activation has been shown to be present in hypoxic patients with chronic obstructive pulmonary disease (COPD). The aims of the present study were to investigate whether there is sympathetic activation in COPD patients in the absence of hypoxia and whether slow breathing has an impact on sympathoexcitation and baroreflex sensitivity. Efferent muscle sympathetic nerve activity, blood pressure, cardiac frequency and respiratory movements were continuously measured in 15 COPD patients and 15 healthy control subjects. Baroreflex sensitivity was analysed by autoregressive spectral analysis and the alpha-angle method. At baseline, sympathetic nerve activity was significantly elevated in COPD patients and baroreflex sensitivity was decreased (5.0+/-0.6 versus 8.9+/-0.8 ms.mmHg(-1)). Breathing at a rate of 6 breaths.min(-1) caused sympathetic activity to drop significantly in COPD patients (from 61.3+/-4.6 to 53.0+/-4.3 bursts per 100 heartbeats) but not in control subjects (39.2+/-3.2 versus 37.5+/-3.3 bursts per 100 heartbeats). In both groups, slow breathing significantly enhanced baroreflex sensitivity. In conclusion, sympathovagal imbalance is present in normoxic chronic obstructive pulmonary disease patients. The possibility of modifying these changes by slow breathing may help to better understand and influence this systemic disease
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The method of modeling stress-strain state for holes burnishing using FEM has been
analyzed. A series of fatigue tests were carried out using plates containing plain holes and cold
expanded holes in aluminium For various diameters of holes and cold expansion degree there exists
a certain correlation between the stress range or maximum stress on the edge of hole on the entrance
face of plate and lifetime of fatigue crack initiation
Molecular species identification of Central European ground beetles (Coleoptera: Carabidae) using nuclear rDNA expansion segments and DNA barcodes
<p>Abstract</p> <p>Background</p> <p>The identification of vast numbers of unknown organisms using DNA sequences becomes more and more important in ecological and biodiversity studies. In this context, a fragment of the mitochondrial cytochrome <it>c </it>oxidase I (COI) gene has been proposed as standard DNA barcoding marker for the identification of organisms. Limitations of the COI barcoding approach can arise from its single-locus identification system, the effect of introgression events, incomplete lineage sorting, numts, heteroplasmy and maternal inheritance of intracellular endosymbionts. Consequently, the analysis of a supplementary nuclear marker system could be advantageous.</p> <p>Results</p> <p>We tested the effectiveness of the COI barcoding region and of three nuclear ribosomal expansion segments in discriminating ground beetles of Central Europe, a diverse and well-studied invertebrate taxon. As nuclear markers we determined the 18S rDNA: V4, 18S rDNA: V7 and 28S rDNA: D3 expansion segments for 344 specimens of 75 species. Seventy-three species (97%) of the analysed species could be accurately identified using COI, while the combined approach of all three nuclear markers provided resolution among 71 (95%) of the studied Carabidae.</p> <p>Conclusion</p> <p>Our results confirm that the analysed nuclear ribosomal expansion segments in combination constitute a valuable and efficient supplement for classical DNA barcoding to avoid potential pitfalls when only mitochondrial data are being used. We also demonstrate the high potential of COI barcodes for the identification of even closely related carabid species.</p
Economic growth in the post-socialist Russian Federation after 1991 : the role of institutions
The paper emphasizes the transition in Russia and the role institutions played before and during the process. In Russia, a ?big bang? approach was applied. That is to say, transition was conducted all of a sudden, omitting important underlying reforms. This practice should function as a shock therapy. Hence, the approach should leave no other chance than an abrupt adaption to the new free-market rules. These rules would then lead to fast economic growth and development, as they did in other places. However, since Russian GDP per capita and thereby living standards deteriorated dramatically in the years after the collapse of the Soviet Union, the plan did not work. At any rate, since then Russian economic indicators recovered and partly achieved their pre-1991 levels at the end of the last decade. The paper depicts Russia?s reform efforts and the subsequent developments. The close ties among the political elite, the banking sector and the old nomenklatura are demonstrated. The patrimonial system that persisted for centuries is still observable at the state level. At any rate, Russia can neither evade its historical and institutional development path nor its societal structures that are based on networks and nepotism. Russia?s systemic lack of the rule of law and therewith of secure property, the character of the Russian political system with the patriarch as the head of state and the resulting necessity of corruption and bribes inhibit the realization of its full growth potential
Association between exposure to environmental tobacco smoke and biomarkers of oxidative stress among patients hospitalised with acute myocardial infarction
Objective
To determine whether exposure to environmental tobacco smoke was associated with oxidative stress among patients hospitalised for acute myocardial infarction.<p></p>
Design
An existing cohort study of 1,261 patients hospitalised for acute myocardial infarction.<p></p>
Setting
Nine acute hospitals in Scotland.<p></p>
Participants
Sixty never smokers who had been exposed to environmental tobacco smoke (admission serum cotinine â„3.0 ng/mL) were compared with 60 never smokers who had not (admission serum cotinine â€0.1 ng/mL).<p></p>
Intervention
None.<p></p>
Main outcome measures
Three biomarkers of oxidative stress (protein carbonyl, malondialdehyde (MDA) and oxidised low-density lipoprotein (ox-LDL)) were measured on admission blood samples and adjusted for potential confounders.<p></p>
Results
After adjusting for baseline differences in age, sex and socioeconomic status, exposure to environmental tobacco smoke was associated with serum concentrations of both protein carbonyl (beta coefficient 7.96, 95% CI 0.76, 15.17, p = 0.031) and MDA (beta coefficient 10.57, 95% CI 4.32, 16.81, p = 0.001) but not ox-LDL (beta coefficient 2.14, 95% CI â8.94, 13.21, p = 0.703).<p></p>
Conclusions
Exposure to environmental tobacco smoke was associated with increased oxidative stress. Further studies are requires to explore the role of oxidative stress in the association between environmental tobacco smoke and myocardial infarction.<p></p>
Finite Temperature DMRG Investigation of the Spin-Peierls Transition in CuGeO
We present a numerical study of thermodynamical properties of dimerized
frustrated Heisenberg chains down to extremely low temperatures with
applications to CuGeO. A variant of the finite temperature density matrix
renormalization group (DMRG) allows the study of the dimerized phase previously
unaccessible to ab initio calculations. We investigate static dimerized systems
as well as the instability of the quantum chain towards lattice dimerization.
The crossover from a quadratic response in the free energy to the distortion
field at finite temperature to nonanalytic behavior at zero temperature is
studied quantitatively. Various physical quantities are derived and compared
with experimental data for CuGeO such as magnetic dimerization, critical
temperature, susceptibility and entropy.Comment: LaTeX, 5 pages, 5 eps figures include
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