474 research outputs found
Mechanical behaviour of irregular fibre materials
This work investigates the effect of fibre irregularities on the mechanical behaviour of the irregular fibres using the finite element method (FEM). The first part of this work examines that the effect of fibre dimensional irregularities on the linear and non-linear tensile behaviour of the fibres, using a two-dimensional (2D) finite element models. In the linear simulation, a concept of method Young’s modulus is introduced. The method Young’s modulus, breaking load and breaking extension are affected by the magnitude and frequency of diameter variation in the fibre specimen. Fibre dimensional variation and the gauge length effect are also simulated. In the non-linear analysis, some additional information is obtained on changes in the yield and post-yield regions, which are clearly shown in the load-extension curves. Further investigation is focused on the flexural buckling behaviour of fibres with dimensional irregularities. A three-dimensional (3D) finite element model is used to simulate the buckling deformation of dimensionally irregular fibres, and the critical buckling load of the simulated fibre is calculated. Two parameters, the effective length and the average diameter within the effective length of an irregular fibre, are considered to be the key factors that influence the buckling behaviour of the fibre. An important aspect of this work is the calculation of the effective length of an irregular fibre specimen during buckling. This method has not been reported before. The third part of this work is on the combined tensile and torsional behaviour of fibres with dimensional irregularities, using a three-dimensional (3D) finite element model. Two types of fibres, polyester and wool, are simulated with sine waves of different level (magnitude) and frequency at different twist levels. For the polyester fibre, experiment verification of the simulation results has been carried out, and the results indicate the FE model is well acceptable for the simulation. The final part of this work examines the combined effect of dimensional and structural irregularities on the fibre tensile behaviour. Three-dimensional (3D) finite element models are used to simulate the cracks (transverse, longitudinal, combined transverse and longitudinal cracks) and cavities distributed in uniform fibres and fibres with 30% level of diameter variation, respectively. One of important conclusions is that under the simulated conditions, the dimensional irregularity of fibre influences the tensile behaviour of fibres more than the fibre structural irregularity. The fibre dimensional irregularity affects not only the values of the breaking load and breaking extension, but also the shape of load-extension curves. However, the fibre structural irregularity simulated in the study appears to have little effect on the shape of the load-extension curves. In addition, the effect of crack or cavity size, type and distribution on fibre tensile properties is also investigated
Characterising the health and social care segment of the BCS (The Chartered Institute for IT) membership and their continuing professional development needs
OBJECTIVES: The aim of this study was to identify and characterise the health and social care membership of the British Computer Society (BCS), an international informatics professional organisation, and to determine their ongoing development needs. METHODS: A prepiloted online survey included items on professional regulatory body, job role, work sector, qualifications, career stage, BCS membership (type, specialist group/branch activity (committees, event attendance)), use of BCS.org career planning/continuing professional development (CPD) tools, self-reported digital literacy and other professional registrations. The quantitative data were analysed using descriptive statistics in JASP V.0.9.2 to report frequencies and correlations. RESULTS: Responses were received from 152 participants. Most were male (n=103; 68%), aged 50–59 years (n=41; 28%), working in England (n=107; 71%) with master’s or honours degrees (n=80; 53%). Most were either new (5 years or less; n=61; 40%) or long-term members (21 years or more; n=43; 28%) of BCS. Most were not interested in health specialist groups (n=57; 38%) preferring non-health specialist groups such as information management (n=54; 37%) and project management (n=52; 34%). DISCUSSION: This is the first paper to characterise the health and social care membership of an IT-focused professional body and to start to determine their CPD needs. There are further challenges ahead in curating the content and delivery. CONCLUSION: This study is the starting point from which members’ CPD needs, and ongoing interest, in being recognised as health and social care professional members, can be acknowledged and explored. Further research is planned with the participants who volunteered to be part of designing future CPD content and delivery
Between Me and The Computer: Increased Detection of Intimate Partner Violence Using a Computer Questionnaire
Study objective: The emergency department is a problem-focused environment in which routine screening for intimate partner violence (IPV) is difficult. We hypothesized that screening for IPV during computer-based health-risk assessment would be acceptable to patients and improve detection.
Methods: We performed a descriptive study of IPV data collected during a controlled trial of computer-based health promotion in an urban hospital ED. Patients received computer-generated health advice, and physicians received patient risk summaries. Outcomes were patient disclosure and physician documentation of IPV and associated risks.
Results: Two hundred forty-eight patients (69% female, 90% black, mean age 39 years) participated in a clinical trial of computer-based health promotion in the ED. Of 170 women, 53 (33%) disclosed emotional abuse, and 25 (15%) disclosed physical abuse. Of 78 men, 22 (29%) disclosed emotional abuse, and 5 (6%) disclosed physical abuse. Patients were also willing to self-report a history or concern of hurting someone close to them. This was true for 21 (14%) women and 15 (22%) men. Controlling for demographic factors, disclosures of victimization and perpetration were associated with multiple psychosocial risks. Computer screening resulted in chart documentation in 19 of 83 potential cases of IPV compared with 1 case documented in the group that received usual care.
Conclusion: Providing an opportunity for patients to confidentially self-disclose IPV has the potential to supplement current screening efforts and to allow providers to focus on assessment, counseling, and referral for those at risk. However, further measures will be needed to ensure that information gathered through computer screening is adequately addressed during the acute care or follow-up visit
A new approach for the analysis of bacterial microarray-based Comparative Genomic Hybridization: insights from an empirical study
BACKGROUND: Microarray-based Comparative Genomic Hybridization (M-CGH) has been used to characterize the extensive intraspecies genetic diversity found in bacteria at the whole-genome level. Although conventional microarray analytical procedures have proved adequate in handling M-CGH data, data interpretation using these methods is based on a continuous character model in which gene divergence and gene absence form a spectrum of decreasing gene conservation levels. However, whereas gene divergence may yet be accompanied by retention in gene function, gene absence invariably leads to loss of function. This distinction, if ignored, leads to a loss in the information to be gained from M-CGH data. We present here results from experiments in which two genome-sequenced strains of C. jejuni were compared against each other using M-CGH. Because the gene content of both strains was known a priori, we were able to closely examine the effects of sequence divergence and gene absence on M-CGH data in order to define analytical parameters for M-CGH data interpretation. This would facilitate the examination of the relative effects of sequence divergence or gene absence in comparative genomics analyses of multiple strains of any species for which genome sequence data and a DNA microarray are available. RESULTS: As a first step towards improving the analysis of M-CGH data, we estimated the degree of experimental error in a series of experiments in which identical samples were compared against each other by M-CGH. This variance estimate was used to validate a Log Ratio-based methodology for identification of outliers in M-CGH data. We compared two genome strains by M-CGH to examine the effect of probe/target identity on the Log Ratios of signal intensities using prior knowledge of gene divergence and gene absence to establish Log Ratio thresholds for the identification of absent and conserved genes. CONCLUSION: The results from this empirical study validate the Log Ratio thresholds that have been used in other studies to establish gene divergence/absence. Moreover, the analytical framework presented here enhances the information content derived from M-CGH data by shifting the focus from divergent/absent gene detection to accurate detection of conserved and absent genes. This approach closely aligns the technical limitations of M-CGH analysis with practical limitations on the biological interpretation of comparative genomics data
Untangling two Chinese Salix species (Salicaceae) published by C. K. Schneider, with lectotypification of four names
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Resuscitating the Physician-Patient Relationship: Emergency Department Communication in an Academic Medical Center
Study objective: We characterize communication in an urban, academic medical center emergency department (ED) with regard to the timing and nature of the medical history survey and physical examination and discharge instructions.
Methods: Audiotaping and coding of 93 ED encounters (62 medical history surveys and physical examinations, 31 discharges) with a convenience sample of 24 emergency medicine residents, 8 nurses, and 93 nonemergency adult patients.
Results: Patients were 68% women and 84% black, with a mean age of 45 years. Emergency medicine providers were 70% men and 80% white. Of 62 medical history surveys and physical examinations, time spent on the introduction and medical history survey and physical examination averaged 7 minutes 31 seconds (range 1 to 20 minutes). Emergency medicine residents introduced themselves in only two thirds of encounters, rarely (8%) indicating their training status. Despite physician tendency (63%) to start with an open-ended question, only 20% of patients completed their presenting complaint without interruption. Average time to interruption (usually a closed question) was 12 seconds. Discharge instructions averaged 76 seconds (range 7 to 202 seconds). Information on diagnosis, expected course of illness, self-care, use of medications, time-specified follow-up, and symptoms that should prompt return to the ED were each discussed less than 65% of the time. Only 16% of patients were asked whether they had questions, and there were no instances in which the provider confirmed patient understanding of the information.
Conclusion: Academic EDs present unique challenges to effective communication. In our study, the physician-patient encounter was brief and lacking in important health information. Provision of patient-centered care in academic EDs will require more provider education and significant system support
Understanding neighborhood environment related to Hong Kong children\u27s physical activity: a qualitative study using nominal group technique
Relationships between the neighborhood environment and children\u27s physical activity have been well documented in Western countries but are less investigated in ultra-dense Asian cities. The aim of this study was to identify the environmental facilitators and barriers of physical activity behaviors among Hong Kong Chinese children using nominal group technique
Deletion of tumor necrosis factor death receptor inhibits amyloid β generation and prevents learning and memory deficits in Alzheimer's mice
The tumor necrosis factor type 1 death receptor (TNFR1) contributes to apoptosis. TNFR1, a subgroup of the TNFR superfamily, contains a cytoplasmic death domain. We recently demonstrated that the TNFR1 cascade is required for amyloid β protein (Aβ)–induced neuronal death. However, the function of TNFR1 in Aβ plaque pathology and amyloid precursor protein (APP) processing in Alzheimer's disease (AD) remains unclear. We report that the deletion of the TNFR1 gene in APP23 transgenic mice (APP23/TNFR1−/−) inhibits Aβ generation and diminishes Aβ plaque formation in the brain. Genetic deletion of TNFR1 leads to reduced β-secretase 1 (BACE1) levels and activity. TNFR1 regulates BACE1 promoter activity via the nuclear factor-κB pathway, and the deletion of TNFR1 in APP23 transgenic mice prevents learning and memory deficits. These findings suggest that TNFR1 not only contributes to neurodegeneration but also that it is involved in APP processing and Aβ plaque formation. Thus, TNFR1 is a novel therapeutic target for AD
Microarray-based comparative genomic profiling of reference strains and selected Canadian field isolates of Actinobacillus pleuropneumoniae
<p>Abstract</p> <p>Background</p> <p><it>Actinobacillus pleuropneumoniae</it>, the causative agent of porcine pleuropneumonia, is a highly contagious respiratory pathogen that causes severe losses to the swine industry worldwide. Current commercially-available vaccines are of limited value because they do not induce cross-serovar immunity and do not prevent development of the carrier state. Microarray-based comparative genomic hybridizations (M-CGH) were used to estimate whole genomic diversity of representative <it>Actinobacillus pleuropneumoniae </it>strains. Our goal was to identify conserved genes, especially those predicted to encode outer membrane proteins and lipoproteins because of their potential for the development of more effective vaccines.</p> <p>Results</p> <p>Using hierarchical clustering, our M-CGH results showed that the majority of the genes in the genome of the serovar 5 <it>A. pleuropneumoniae </it>L20 strain were conserved in the reference strains of all 15 serovars and in representative field isolates. Fifty-eight conserved genes predicted to encode for outer membrane proteins or lipoproteins were identified. As well, there were several clusters of diverged or absent genes including those associated with capsule biosynthesis, toxin production as well as genes typically associated with mobile elements.</p> <p>Conclusion</p> <p>Although <it>A. pleuropneumoniae </it>strains are essentially clonal, M-CGH analysis of the reference strains of the fifteen serovars and representative field isolates revealed several classes of genes that were divergent or absent. Not surprisingly, these included genes associated with capsule biosynthesis as the capsule is associated with sero-specificity. Several of the conserved genes were identified as candidates for vaccine development, and we conclude that M-CGH is a valuable tool for reverse vaccinology.</p
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