Home About us Contact
|
Home About us Contact | ||
|
|
||
Logistical Difficulties (logistical + difficulty)
Selected AbstractsCauses and consequences of animal dispersal strategies: relating individual behaviour to spatial dynamicsBIOLOGICAL REVIEWS, Issue 2 2005Diana E. Bowler ABSTRACT Knowledge of the ecological and evolutionary causes of dispersal can be crucial in understanding the behaviour of spatially structured populations, and predicting how species respond to environmental change. Despite the focus of much theoretical research, simplistic assumptions regarding the dispersal process are still made. Dispersal is usually regarded as an unconditional process although in many cases fitness gains of dispersal are dependent on environmental factors and individual state. Condition-dependent dispersal strategies will often be superior to unconditional, fixed strategies. In addition, dispersal is often collapsed into a single parameter, despite it being a process composed of three interdependent stages: emigration, inter-patch movement and immigration, each of which may display different condition dependencies. Empirical studies have investigated correlates of these stages, emigration in particular, providing evidence for the prevalence of conditional dispersal strategies. Ill-defined use of the term ,dispersal', for movement across many different spatial scales, further hinders making general conclusions and relating movement correlates to consequences at the population level. Logistical difficulties preclude a detailed study of dispersal for many species, however incorporating unrealistic dispersal assumptions in spatial population models may yield inaccurate and costly predictions. Further studies are necessary to explore the importance of incorporating specific condition-dependent dispersal strategies for evolutionary and population dynamic predictions. [source] EVOLUTIONARY POTENTIAL OF A LARGE MARINE VERTEBRATE: QUANTITATIVE GENETIC PARAMETERS IN A WILD POPULATIONEVOLUTION, Issue 4 2009Joseph D. DiBattista Estimating quantitative genetic parameters ideally takes place in natural populations, but relatively few studies have overcome the inherent logistical difficulties. For this reason, no estimates currently exist for the genetic basis of life-history traits in natural populations of large marine vertebrates. And yet such estimates are likely to be important given the exposure of this taxon to changing selection pressures, and the relevance of life-history traits to population productivity. We report such estimates from a long-term (1995,2007) study of lemon sharks (Negaprion brevirostris) conducted at Bimini, Bahamas. We obtained these estimates by genetically reconstructing a population pedigree (117 dams, 487 sires, and 1351 offspring) and then using an "animal model" approach to estimate quantitative genetic parameters. We find significant additive genetic (co)variance, and hence moderate heritability, for juvenile length and mass. We also find substantial maternal effects for these traits at age-0, but not age-1, confirming that genotype,phenotype interactions between mother and offspring are strongest at birth; although these effects could not be parsed into their genetic and nongenetic components. Our results suggest that human-imposed selection pressures (e.g., size-selective harvesting) might impose noteworthy evolutionary change even in large marine vertebrates. We therefore use our findings to explain how maternal effects may sometimes promote maladaptive juvenile traits, and how lemon sharks at different nursery sites may show "constrained local adaptation." We also show how single-generation pedigrees, and even simple marker-based regression methods, can provide accurate estimates of quantitative genetic parameters in at least some natural systems. [source] Surveying older people from minority ethnic groups: an evaluation of a primary care sampling method for UK African-Caribbean eldersINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 4 2002Dr Robert Stewart Abstract There are substantial logistical difficulties in conducting community surveys of minority ethnic group populations. Primary care lists have been identified as an important potential resource but the representativeness of samples derived through this method has received little evaluation. In a community survey of psychiatric morbidity, African-Caribbean people aged 55,75 were identified by practice staff from registration lists for seven primary care teams in south London. The sensitivity of the process was evaluated by contacting a random sample of people whose ethnicity was not known. Participants aged 65,75 (n = 174) were also compared to a similarly aged group sampled through household enumeration (n = 34) with respect to demographic factors, risk factors for vascular disease, depression and cognitive function. For those with correct addresses, the identified group was estimated to include 72% of the potentially eligible population. Only 8% of contacted people were found not to be eligible in terms of ethnicity. Compared to the household enumeration sample, the primary care sample had marginally higher socio-economic status but was similar with respect to all other measured characteristics. Primary care list sampling with staff-assigned ethnicity therefore appeared highly specific, reasonably sensitive, and did not seem to introduce substantial bias for this population. Copyright © 2002 Whurr Publishers Ltd. [source] Implementing bedside handover: strategies for change managementJOURNAL OF CLINICAL NURSING, Issue 17-18 2010Anne McMurray Aims and objectives., To identify factors influencing change in two hospitals that moved from taped and verbal nursing handover to bedside handover. Background., Bedside handover is based on patient-centred care, where patients participate in communicating relevant and timely information for care planning. Patient input reduces care fragmentation, miscommunication-related adverse events, readmissions, duplication of services and enhances satisfaction and continuity of care. Design., Analysing change management was a component of a study aimed at developing a standard operating protocol for bedside handover communication. The research was undertaken in two regional acute care hospitals in two different states of Australia. Method., Data collection included 532 semi-structured observations in six wards in the two hospitals and 34 in-depth interviews conducted with a purposive sample of nursing staff involved in the handovers. Observation and interview data were analysed separately then combined to generate thematic analysis of factors influencing the change process in the transition to bedside handover. Results and conclusion., Themes included embedding the change as part of the big picture, the need to link the project to standardisation initiatives, providing reassurance on safety and quality, smoothing out logistical difficulties and learning to listen. We conclude that change is more likely to be successful when it is part of a broader initiative such as a quality improvement strategy. Relevance to clinical practice., Nurses are generally supportive of quality improvement initiatives, particularly those aimed at standardising care. For successful implementation, change managers should be mindful of clinicians' attitudes, motivation and concerns and their need for reassurance when changing their practice. This is particularly important when change is dramatic, as in moving from verbal handover, conducted in the safety of the nursing office, to bedside handover where there is greater transparency and accountability for the accuracy and appropriateness of communication content and processes. [source] Self-help in the long-term treatment of obesityOBESITY REVIEWS, Issue 2 2001J. D. Latner Summary Despite the short-term success of professional behavioural techniques for obesity, weight losses are typically regained following treatment. The long-term maintenance of treatment effects will probably require ongoing, continuing care. Continuing care may be economically feasible when administered through self-help treatment modalities. Self-help confers a number of psychological benefits, such as self-reliance and an increased sense of empowerment. The effectiveness and cost-effectiveness of various modalities of self-help are reviewed, including purely self-prompted help, self-administered manuals, computer-assisted therapy, professionally assisted correspondence courses, and non-profit and commercial self-help groups. Stepped-care models suggest using a combination of these approaches when appropriate. However, logistical difficulties present themselves in stepped-care approaches with obesity, such as the complicating effects of severity and comorbidity on stepped-care status. Self-help groups are a promising venue for the provision of continuing care and as an adjunct to more intensive, specialty therapies. [source] The Quality of Health Insurance Service Delivery for Kidney Transplant Recipients: A Patient PerspectiveAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2010E. J. Gordon Increased attention has been devoted to improving quality care in kidney transplantation. The discourse on quality care has focused on transplant center metrics and other clinical parameters. However, there has been little discussion on the quality of health insurance service delivery, which may be critical to kidney recipients' access to transplantation and immunosuppression. This paper describes and provides a framework for characterizing kidney transplant recipients' positive and negative interactions with their insurers. A consecutive cohort of kidney recipients (n = 87) participated in semistructured interviews on their interactions with insurance agencies. Patients reported negative (37%) and/or neutral or positive (79%) interactions with their insurer (a subset [16%] reported both). Perceived negative experiences included: poor service, logistical difficulties with confusing and time-consuming paperwork, poor communication, rude behavior and concerns about adequate coverage. Positive experiences related to: having good coverage, a simple application process, straightforward transactions and helpful communication. Findings suggest that even when patients have insurance coverage, difficult interactions with insurers and limited skills in navigating insurance options may limit their access to needed medications and health services. Future research is needed to test this hypothesis in a larger population. [source] Decision-making models in the analysis of portal films: A clinical pilot studyJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 1 2000Andrew See SUMMARY Portal films continue to play an important role in the verification of radiotherapy treatment. There is still some discussion, however, as to what action should be taken after a port film has shown a radiation field deviation from the prescribed volume. It was the aim of the present pilot study to investigate the performance of three decision-making models (,Amsterdam', ,Quebec' and ,Newcastle') and an expert panel basing their decision on intuition rather than formal rules after portal film acquisition in a clinical setting. Portal films were acquired on every day during the first week of treatment for five head and neck and five prostate cancer patients (diagnostic phase). If required, the field position was modified according to our normal practice following the recommendation of the expert panel. In order to analyse the results of the models, however, additional port films were taken in the following 3 treatment weeks with the patient moved as required by the different models (intervention phase). The portal films were taken over 4 consecutive days, positioning the patient according to each of the different models on one day each. None of the models diagnosed a field misplacement in the head and neck patients, while the ,Amsterdam' and ,Quebec' models predicted a move in one prostate patient. The ,Newcastle' model, which is based on Hotelling's T 2 statistic, proved to be more sensitive and diagnosed a systematic displacement for three prostate patients. The intervention phase confirmed the diagnosis of the model, even if the three portal films taken with the patient position adjusted as required by the model proved to be insufficient to demonstrate an improvement. The ,Newcastle' model does not rely on assumptions about the random movement of patients and requires five portal films before a decision can be reached. This approach lends itself well to incorporation into electronic portal imaging ,packages', where repeated image acquisitions present no logistical difficulty. [source] | |||||||||||||