The coset D-branes of SU(n)

Using a nested coset construction a collection of D-branes that appear to generate all the K-theory charges of string theory on SU(n) are constructed and their charges are determined.Comment: 12 page

Duration judgements in patients with schizophrenia

Background. The ability to encode time cues underlies many cognitive processes. In the light of schizophrenic patients' compromised cognitive abilities in a variety of domains, it is noteworthy that there are numerous reports of these patients displaying impaired timing abilities. However, the timing intervals that patients have been evaluated on in prior studies vary considerably in magnitude (e.g. 1 s, 1 min, 1 h etc.). Method. In order to obviate differences in abilities in chronometric counting and place minimal demands on cognitive processing, we chose tasks that involve making judgements about brief durations of time (<1 s). Results. On a temporal generalization task, patients were less accurate than controls at recognizing a standard duration. The performance of patients was also significantly different from controls on a temporal bisection task, in which participants categorized durations as short or long. Although time estimation may be closely intertwined with working memory, patients' working memory as measured by the digit span task did not correlate significantly with their performance on the duration judgement tasks. Moreover, lowered intelligence scores could not completely account for the findings. Conclusions. We take these results to suggest that patients with schizophrenia are less accurate at estimating brief time periods. These deficits may reflect dysfunction of biopsychological timing processes

The Nursing Community Apgar Questionnaire in Rural Australia: An Evidence Based Approach to Recruiting and Retaining Nurses

Purpose: To date, the Nursing Community Apgar Questionnaire (NCAQ) has been effectivly utlized to quantify resources and capabilities of a rural Idaho communities to recruit and retain nurses. As such, the NCAQ was used in a rural Australian context to examine its efficacy as an evidence-based tool to better inform nursing recruitment and retention. Sample: The sample included nursing administrators, senior nurses and other nurses from six health facilities who were familiar with the community and knowledgeable with health facility recruitment and retention history. Participants were registered nurses and/or directly involved in nursing recruitment. Method: The 50 factor NCAQ was administered online. Data were cleaned, checked, and analyzed by assigning quantitative values to the four-point scale of community advantages or challenges for each factor and then weighted according to the participant’s perceived importance to create a community asset and capability measure. Higher scores represented more developed community assets and capabilities relating to nursing recruitment and retention. Findings: The findings demonstrate that lifestyle, emphasis on patient safety and high quality care, availability of necessary materials and equipment, perception of quality were among the highest scoring factors and considered to have the most impact on recruiting and retaining nurses. The lowest factors impacting recruitment and retention included spousal satisfaction, access to larger communities, and opportunities for social networking within communities. Conclusions: The implementation of the NCAQ has the capacity to offer health facilities and managers to examine what is appealing about the health service and community, while highlighting key challenges impacting recruitment and retention. The NCAQ assists health services to develop strategic plans tailored specifically to enhance recruitment and retention of nursing staff. Its use has the capacity to provide health services with greater evidence as they seek to address site specific or regional recruitment and retention issues

English Learning Strategies among EFL Learners: A Narrative Approach

Language learning strategies (LLSs) are believed to be influenced by individual differences as well as environmental and contextual factors. Therefore, the effective use of LLSs is determined by various factors, including both learning and learner variables. This dynamic and complex nature of LLSs renders it appropriate to use a qualitative approach to undertake research into this issue. This paper details the qualitative findings from a larger-scale study on English LLSs among tertiary students in the context of Vietnam. The data was gathered from semi-structured interviews with 10 English as a foreign language (EFL) teaching staff and 10 EFL students at a university in Vietnam. Interviews were conducted in Vietnamese lasting 30 to 40 minutes, and were audio recorded with consent. The interview questions for students focussed on their general attitudes and lived experiences of LLSs. Similarly, the interview questions for EFL staff were structured around their general attitudes. The interview data were translated into English, rechecked, and thematically analysed. The findings are of a textual and interpretative nature with emerging themes and issues related to the attitudes towards and actual use of LLSs among the target learners. The findings provide practical implications for practitioners, researchers and educational policy makers alike

Indeterminacy and instability in Petschek reconnection

We explain two puzzling aspects of Petschek's model for fast reconnection. One is its failure to occur in plasma simulations with uniform resistivity. The other is its inability to provide anything more than an upper limit for the reconnection rate. We have found that previously published analytical solutions based on Petschek's model are structurally unstable if the electrical resistivity is uniform. The structural instability is associated with the presence of an essential singularity at the X-line that is unphysical. By requiring that such a singularity does not exist, we obtain a formula that predicts a specific rate of reconnection. For uniform resistivity, reconnection can only occur at the slow, Sweet-Parker rate. For nonuniform resistivity, reconnection can occur at a much faster rate provided that the resistivity profile is not too flat near the X-line. If this condition is satisfied, then the scale length of the nonuniformity determines the reconnection rate

Whole-Genome Sequencing and Concordance Between Antimicrobial Susceptibility Genotypes and Phenotypes of Bacterial Isolates Associated with Bovine Respiratory Disease.

Extended laboratory culture and antimicrobial susceptibility testing timelines hinder rapid species identification and susceptibility profiling of bacterial pathogens associated with bovine respiratory disease, the most prevalent cause of cattle mortality in the United States. Whole-genome sequencing offers a culture-independent alternative to current bacterial identification methods, but requires a library of bacterial reference genomes for comparison. To contribute new bacterial genome assemblies and evaluate genetic diversity and variation in antimicrobial resistance genotypes, whole-genome sequencing was performed on bovine respiratory disease-associated bacterial isolates (Histophilus somni, Mycoplasma bovis, Mannheimia haemolytica, and Pasteurella multocida) from dairy and beef cattle. One hundred genomically distinct assemblies were added to the NCBI database, doubling the available genomic sequences for these four species. Computer-based methods identified 11 predicted antimicrobial resistance genes in three species, with none being detected in M. bovis While computer-based analysis can identify antibiotic resistance genes within whole-genome sequences (genotype), it may not predict the actual antimicrobial resistance observed in a living organism (phenotype). Antimicrobial susceptibility testing on 64 H. somni, M. haemolytica, and P. multocida isolates had an overall concordance rate between genotype and phenotypic resistance to the associated class of antimicrobials of 72.7% (P &lt; 0.001), showing substantial discordance. Concordance rates varied greatly among different antimicrobial, antibiotic resistance gene, and bacterial species combinations. This suggests that antimicrobial susceptibility phenotypes are needed to complement genomically predicted antibiotic resistance gene genotypes to better understand how the presence of antibiotic resistance genes within a given bacterial species could potentially impact optimal bovine respiratory disease treatment and morbidity/mortality outcomes

Prefrontal Cortex Modulation during Anticipation of Working Memory Demands as Revealed by Magnetoencephalography

During the anticipation of task demands frontal control is involved in the assembly of stimulus-response mappings based on current goals. It is not clear whether prefrontal modulations occur in higher-order cortical regions, likely reflecting cognitive anticipation processes. The goal of this paper was to investigate prefrontal modulation during anticipation of upcoming working memory demands as revealed by magnetoencephalography (MEG). Twenty healthy volunteers underwent MEG while they performed a variation of the Sternberg Working Memory (WM) task. Beta band (14–30 Hz) SAM (Synthetic Aperture Magnetometry) analysis was performed. During the preparatory periods there was an increase in beta power (event-related synchronization) in dorsolateral prefrontal cortex (DLPFC) bilaterally, left inferior prefrontal gyrus, left parietal, and temporal areas. Our results provide support for the hypothesis that, during preparatory states, the prefrontal cortex is important for biasing higher order brain regions that are going to be engaged in the upcoming task