2,347 research outputs found
Muon spin rotation studies of niobium for superconducting RF applications
In this work we investigate superconducting properties of niobium samples via
application of the muon spin rotation/relaxation (muSR) technique. We employ
for the first time the muSR technique to study samples that are cutout from
large and small grain 1.5 GHz radio frequency (RF) single cell niobium
cavities. The RF test of these cavities was accompanied by full temperature
mapping to characterize the RF losses in each of the samples. Results of the
muSR measurements show that standard cavity surface treatments like mild baking
and buffered chemical polishing (BCP) performed on the studied samples affect
their surface pinning strength. We find an interesting correlation between high
field RF losses and field dependence of the sample magnetic volume fraction
measured via muSR. The muSR line width observed in ZF-muSR measurements matches
the behavior of Nb samples doped with minute amounts of Ta or N impurities. An
upper bound for the upper critical field Hc2 of these cutouts is found.Comment: 20 pages, 14 figure
Comparison of two histological techniques for age determination in small cetaceans
Peer reviewedPreprin
Automated computational cognitive-modeling: goal-specific analysis for large websites
The information architecture of websites is the most important remaining source of usability problems. Therefore, this research explores automated cognitive computational analysis of the information architecture of large websites as a basis for improvement. To support goal-specific analysis, an enhanced model of web navigation was implemented with a novel database-oriented approach. Web navigation was simulated on the information architecture of two large sites. With the improved labeling system of the information architecture, simulation results showed a significant reduction in navigation problems. The results of two experiments demonstrate that sites with improved information architecture result in better outcomes of user information retrieval. Our database-oriented approach is extensible, allowing non-goal-specific analysis, modeling of nontext media content, and analysis of the organization- and navigation systems of information architectures.</jats:p
Isolation and characterization of the full-length cDNA encoding a member of a novel cytochrome p450 family (CYP320A1) from the tropical freshwater snail, Biomphalaria glabrata, intermediate host for Schistosoma mansoni
Cytochrome p450s (cyp450s) are a family of structurally related proteins, with diverse functions, including steroid synthesis and breakdown of toxins. This paper reports the full-length sequence of a novel cyp450 gene, the first to be isolated from the tropical freshwater snail Biomphalaria glabrata, an important intermediate host of Schistosoma mansoni. The nucleotide sequence is 2291 bp with a predicted amino acid sequence of 584aa. The sequence demonstrates conserved cyp450 structural motifs, but is sufficiently different from previously reported cyp450 sequences to be given a new classification, CYP320A1. Initially identified as down-regulated in partially resistant snails in response to S. mansoni infection, amplification of this gene using RT-PCR in both totally resistant or susceptible snail lines when exposed to infection, and all tissues examined, suggests ubiquitous expression. Characterization of the first cyp450 from B. glabrata is significant in understanding the evolution of these metabolically important proteins
Musculoskeletal education: a curriculum evaluation at one university
<p>Abstract</p> <p>Background</p> <p>The increasing burden of illness related to musculoskeletal diseases makes it essential that attention be paid to musculoskeletal education in medical schools. This case study examines the undergraduate musculoskeletal curriculum at one medical school.</p> <p>Methods</p> <p>A case study research methodology used quantitative and qualitative approaches to systematically examine the undergraduate musculoskeletal course at the University of Calgary (Alberta, Canada) Faculty of Medicine. The aim of the study was to understand the strengths and weaknesses of the curriculum guided by four questions: (1) Was the course structured according to standard principles for curriculum design as described in the Kern framework? (2) How did students and faculty perceive the course? (3) Was the assessment of the students valid and reliable? (4) Were the course evaluations completed by student and faculty valid and reliable?</p> <p><b>Results</b></p> <p>The analysis showed that the structure of the musculoskeletal course mapped to many components of Kern's framework in course design. The course had a high level of commitment by teachers, included a valid and reliable final examination, and valid evaluation questionnaires that provided relevant information to assess curriculum function. The curricular review identified several weaknesses in the course: the apparent absence of a formalized needs assessment, course objectives that were not specific or measurable, poor development of clinical presentations, small group sessions that exceeded normal 'small group' sizes, and poor alignment between the course objectives, examination blueprint and the examination. Both students and faculty members perceived the same strengths and weaknesses in the curriculum. Course evaluation data provided information that was consistent with the findings from the interviews with the key stakeholders.</p> <p>Conclusions</p> <p>The case study approach using the Kern framework and selected questions provided a robust way to assess a curriculum, identify its strengths and weaknesses and guide improvements.</p
Identification. The missing link between joint attention and imitation
In this paper we outline our hypothesis that human intersubjective engagement entails identifying with other people. We tested a prediction derived from this hypothesis that concerned the relation between a component of joint attention and a specific form of imitation. The empirical investigation involved âblindâ ratings of videotapes from a recent study in which we tested matched children with and without autism for their propensity to imitate the self-/other-orientated aspects of another person's actions. The results were in keeping with three a priori predictions, as follows: (a) children with autism contrasted with control participants in spending more time looking at the objects acted upon and less time looking at the tester; (b) participants with autism showed fewer âsharingâ looks toward the tester, and although they also showed fewer âcheckingâ and âorientatingâ looks, they were specifically less likely to show any sharing looks; and, critically, (c) within each group, individual differences in sharing looks (only) were associated with imitation of selfâother orientation. We suggest that the propensity to adopt the bodily anchored psychological stance of another person is essential to certain forms of joint attention and imitation, and that a weak tendency to identify with others is pivotal for the developmental psychopathology of autism
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