962 research outputs found
Community attitudes to institutional care of the aged in Hong Kong
The objective of the study was to assess community attitudes to institutional care of the aged in Hong Kong. A random sample of 1,023 adult residents were telephone-interviewed. 22.7% and 57.5% of the respondents agreed or strongly agreed that non-disabled and disabled elderly be accommodated in institutions respectively. Social factors of the respondents and physical and behavioural factors of the elderly had significant effects on these attitudes. Furthermore, age, gender, educational level and experience in living or looking after elderly also had significant effects. This study provides important information on the community attitudes to institutionalization of the elderly in Hong Kong. These attitudes will have significant effects on the demand for institutional care for the elderly in the next decade. The findings should also help health care workers identify elderly at-risk of institutionalization. Hence, early intervention may help reduce some of these placements.published_or_final_versio
Cumulative loading of the lumbar spine during non-occupational activities.
The purpose of the study is to document peak and cumulative estimates on the lumbar spine in the laboratory setting as well as cumulative loading estimates on the lumbar spine in a field setting. Further, this study was also designed to compare video methods and electromyography methods of estimating cumulative compression on the lumbar spine. The variables measured in the laboratory study include both peak and cumulative estimates of compression, reaction shear, joint shear and moment, while the field study measured only cumulative estimates of these variables. The majority of tasks in both the lab and field portion of the study required the subjects to handle loads less then 10 kg. Further, peak estimates of lumbar compression reported in the literature for industrial tasks still display higher loading profiles. This gives the impression that household activities are less physically challenging than industrial tasks. This assumption is misleading as only a small number of tasks and subjects have been studied outside the industrial setting thus far. The spine is loaded in a number of ways during the day and further analysis with a greater variety of asymmetric tasks will undoubtedly yield greater loading estimates for non-occupational activities. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .L38. Source: Masters Abstracts International, Volume: 41-04, page: 1099. Adviser: David Andrews. Thesis (M.H.K.)--University of Windsor (Canada), 2002
Pathogenic Mannheimia haemolytica invades differentiated bovine airway epithelial cells
The Gram-negative bacterium Mannheimia haemolytica is the primary bacterial species associated with bovine respiratory disease (BRD) which is responsible for significant economic losses to the livestock industries worldwide. Healthy cattle are frequently colonised by commensal serotype A2 strains, but disease is usually caused by pathogenic strains of serotype A1. For reasons that are poorly understood, a transition occurs within the respiratory tract and a sudden explosive proliferation of serotype A1 bacteria leads to the onset of pneumonic disease. Very little is known about the interactions of M. haemolytica with airway epithelial cells of the respiratory mucosa which might explain the different abilities of serotype A1 and A2 strains to cause disease. In the present study, host-pathogen interactions in the bovine respiratory tract were mimicked using a novel differentiated bovine bronchial epithelial cell (BBEC) infection model. In this model, differentiated BBECs were inoculated with serotype A1 or A2 strains of M. haemolytica and the course of infection followed over a five-day period by microscopic assessment and measurement of key proinflammatory mediators. We have demonstrated that serotype A1, but not A2, M. haemolytica invades differentiated BBECs by transcytosis and subsequently undergoes rapid intracellular replication before spreading to adjacent cells and causing extensive cellular damage. Our findings suggest that the explosive proliferation of serotype A1 M. haemolytica that occurs within the bovine respiratory tract prior to the onset of pneumonic disease is potentially due to bacterial invasion of, and rapid proliferation within, the mucosal epithelium. The discovery of this previously unrecognised mechanism of pathogenesis is important because it will allow the serotype A1-specific virulence determinants responsible for invasion to be identified and thereby provide opportunities for the development of new strategies for combatting BRD aimed at preventing early colonisation and infection of the bovine respiratory tract
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Escaping the flow: boundary layer use by the darter Etheostoma tetrazonum (Percidae) during benthic station holding
Aquatic habitats characterized by directional water flow (lotic environments) pose numerous challenges to their inhabitants, including the constant threat of dislodgement and downstream transport. As a result, many organisms exhibit morphological and/or behavioral adaptations that facilitate midwater or benthic station holding in these environments, such as the ventral sucker disc of armored catfishes. However, a few groups, including the species-rich group of small (7–8cm long and 1–2cm high) North American stream fishes called darters, exhibit no obvious morphological adaptations to life in lotic habitats. We therefore asked whether small size itself facilitates benthic station holding in these fish. We first used digital particle image velocimetry to quantify the fluid dynamics of flow over a variety of substrates. We then visualized the patterns of flow over the darter Etheostoma tetrazonum during benthic station holding. The thickness of the region of decreased water velocity (i.e. the boundary layer) associated with several types of rocky substrate was large enough (~2 cm high in some cases) for E. tetrazonum and many other darter species to escape the oncoming flow. We also found that, despite the large size of its pectoral fins, E. tetrazonum is capable of producing only very weak negative lift forces with fins. These substrate-directed forces likely act in conjunction with upstream-directed frictional forces between the tail, anal and pelvic fins and the substrate to facilitate station holding. Thus, we hypothesize that, in darters, small size is an adaptation to life in the benthic boundary layer of lotic environments.Organismic and Evolutionary Biolog
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Hydrodynamics of surface swimming in leopard frogs (Rana pipiens)
The kinematics of swimming frogs have been studied extensively in the past and, based on these results, hypotheses regarding the hydrodynamics of frog swimming can be generated. To test these hypotheses we used digital particle image velocimetry (DPIV) to quantify the flow structure of the wake produced by the feet during the propulsion phase of the kick of surface swimming frogs (Rana pipiens). These frogs use two different gaits, asynchronous and synchronous kicking, and the magnitude of the thrust produced by the feet differs between asynchronous (34±5.4·mN·foot–1) and synchronous kicking (71±13.3·mN·foot–1), as does maximum swimming speed, with higher swimming speed and forces produced during the synchronous kicks. Previous studies have suggested that an interaction between the feet, resulting in a single posteriorly directed fluid jet, as the feet come together at the end of synchronous kicks, may augment force production. Our results show, however, that each foot produces its own distinct vortex ring, in both asynchronous and synchronous kicking of the feet. There is no evidence of a central jet being produced even during powerful synchronous kicks (maximum thrust calculated was 264·mN·foot–1). An alternative mechanism of force production could be the lift-based paddling recently suggested for delta-shaped feet of swimming birds. However, the orientation of the vortex rings generated by the feet is almost perpendicular to the swimming direction for both gaits and there is only a slight asynchrony of the shedding of the distal (start) and proximal (stop) vortex rings, which is different from what would be expected by a dominantly lift-based mechanism. Thus, our results do not support lift as a major mechanism contributing to thrust. Instead, our data support the hypothesis that propulsion is based on drag and acceleration reaction forces where the thrust is generated by separated, but attached, vortex rings on the suction side of the feet, resulting in vortices that are shed behind the frogs during both asynchronous and synchronous kicking.Organismic and Evolutionary Biolog
‘Push on through’:Children’s perspectives on the narratives of resilience in schools identified for intensive mental health promotion
Child mental health is a growing concern for policymakers across the global north. Schools have become a key site for mental health interventions, with new programmes aimed at promoting ‘resilience’, through which children may maintain or regain mental health during adversity. As one of the first studies to explore the early impact of intensive mental health promotion in schools from children’s perspectives, we adopt a governmentality approach to consider the logic and techniques of such programmes with a specific focus on England. An innovative visual methodology was used to focus on student perspectives of mental health interventions in school. Young peoples’ photo representations of mental health were collected and used to stimulate focus group discussions with 65 students aged 12–14, across seven schools. ‘Resilience’ was seen to be the key organising concept for mental health interventions in schools. The concept was viewed as narrowly focused on attitude towards—and performance in—school work, with individuals being encouraged to ‘push on through’ difficulties to achieve success. Young people were critical of this approach, suggesting several alternatives. These included increased access to independent mental health professionals, safe spaces within schools and mental health education that addressed the social and affective dimensions of mental health difficulties
A drug-induced hypotensive challenge to verify catheter-based radiofrequency renal denervation in an obese hypertensive swine model
Objective
Sham-controlled trials provided proof-of-principle for the blood pressure-lowering effect of catheter-based renal denervation (RDN). However, indicators for the immediate assessment of treatment success are lacking. This study sought to investigate the impact of RDN on renal renin arteriovenous difference (renal renin AV-Δ) following a hypotensive challenge (HC).
Methods
Twelve hypertensive Ossabaw swine underwent either combined surgical and chemical (n = 3) or catheter-based RDN (n = 9). A telemetry monitor was implanted to acquire hemodynamic data continuously. Before and after RDN, a sodium nitroprusside-induced HC was performed. Renal renin AV-Δ was calculated as the difference of plasma renin concentrations drawn from the renal artery and vein.
Results
In total, complete renal renin AV data were obtained in eight animals at baseline and six animals at baseline and 3 months of follow-up. Baseline renal renin AV-Δ correlated inversely with change in 24-h minimum systolic (− 0.764, p = 0.02), diastolic (r = − 0.679, p = 0.04), and mean (r = − 0.663, p = 0.05) blood pressure. In the animals with complete renin secretion data at baseline and follow-up, the HC increased renal renin AV-Δ at baseline, while this effect was attenuated following RDN (0.55 ± 0.34 pg/ml versus − 0.10 ± 0.16 pg/ml, p = 0.003). Renin urinary excretion remained unchanged throughout the study (baseline 0.286 ± 0.187 pg/ml versus termination 0.305 ± 0.072 pg/ml, p = 0.789).
Conclusion
Renin secretion induced by HC was attenuated following RDN and may serve as an indicator for patient selection and guide successful RDN procedures
The impact of marketisation on postgraduate career preparedness in a high skills economy
This study focuses on the consequences for high skills development of the erosion of the once clear demarcation between higher education and business. It contributes to the broader debate about the relevance of higher education for thewell-being of the society of the future. The research explores the effects of marketisation on the postgraduate curriculum and students’ preparedness for careers in public relations and marketing communications. Interviews with lecturers and students in two universities in the UK and Australia indicate that a tension exists between academic rigour and corporate relevancy. The consequences are a diminution of academic attachment to critique and wider social/cultural engagement, with a resulting impoverishment of students’ creative abilities and critical consciences. Subsequently, graduates of public relations and marketing communications, and to some extent those from other profession-related disciplines, are insufficiently prepared for careers as knowledge workers in a future high-skills economy
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A robotic fish caudal fin: effects of stiffness and motor program on locomotor performance
We designed a robotic fish caudal fin with six individually moveable fin rays based on the tail of the bluegill sunfish, Lepomis macrochirus. Previous fish robotic tail designs have loosely resembled the caudal fin of fishes, but have not incorporated key biomechanical components such as fin rays that can be controlled to generate complex tail conformations and motion programs similar to those seen in the locomotor repertoire of live fishes. We used this robotic caudal fin to test for the effects of fin ray stiffness, frequency and motion program on the generation of thrust and lift forces. Five different sets of fin rays were constructed to be from 150 to 2000 times the stiffness of biological fin rays, appropriately scaled for the robotic caudal fin, which had linear dimensions approximately four times larger than those of adult bluegill sunfish. Five caudal fin motion programs were identified as kinematic features of swimming behaviors in live bluegill sunfish, and were used to program the kinematic repertoire: flat movement of the entire fin, cupping of the fin, W-shaped fin motion, fin undulation and rolling movements. The robotic fin was flapped at frequencies ranging from 0.5 to 2.4Hz. All fin motions produced force in the thrust direction, and the cupping motion produced the most thrust in almost all cases. Only the undulatory motion produced lift force of similar magnitude to the thrust force. More compliant fin rays produced lower peak magnitude forces than the stiffer fin rays at the same frequency. Thrust and lift forces increased with increasing flapping frequency; thrust was maximized by the 500 stiffness fin rays and lift was maximized by the 1000 stiffness fin rays.Organismic and Evolutionary Biolog
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