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Population Ratio (population + ratio)
Selected AbstractsFixed fees and physician-induced demand: A panel data study on French physiciansHEALTH ECONOMICS, Issue 9 2003Eric Delattre Abstract This paper investigates on the existence of physician-induced demand (PID) for French physicians. The test is carried out for GPs and specialists, using a representative sample of 4500 French self-employed physicians over the 1979,1993 period. These physicians receive a fee-for-services (FFS) payment and fees are controlled. The panel structure of our data allows us to take into account unobserved heterogeneity related to the characteristics of physicians and their patients. We use generalized method of moments (GMM) estimators in order to obtain consistent and efficient estimates. We show that physicians experience a decline of the number of consultations when they face an increase in the physician:population ratio. However this decrease is very slight. In addition, physicians counterbalance the fall in the number of consultations by an increase in the volume of care delivered in each encounter. Econometric results give a strong support for the existence of PID in the French system for ambulatory care. Copyright © 2003 John Wiley & Sons, Ltd. [source] Reproductive interference determines persistence and exclusion in species interactionsJOURNAL OF ANIMAL ECOLOGY, Issue 5 2009Shigeki Kishi Summary 1.,Reproductive interference is a negative interspecific sexual interaction that adversely affects the fitness of males and females during reproductive process. Theoretical studies suggest that because reproductive interference is characterized by positive frequency dependence it is far more likely to cause species exclusion than the density dependence of resource competition. However, the respective contributions of resource competition and reproductive interference to species exclusion, which have been frequently observed in many competition studies, remain unclear. 2.,We show that reproductive interference is a far more critical cause of species exclusion than resource competition in the competition between Callosobruchus bean weevil species. In competition experiments over several generations, we manipulated the initial relative abundance of the adzuki bean beetle, Callosobruchus chinensis, and the southern cowpea beetle, Callosobruchus maculatus. When the initial adult ratio of C. chinensis : C. maculatus were 6 : 2 and 4 : 4, C. chinensis excluded C. maculatus. However, when C. maculatus was four times more abundant than C. chinensis at the start, we observed the opposite outcome. 3.,A behavioural experiment using adults of the two species revealed asymmetric reproductive interference. The fecundity and longevity of C. maculatus females, but not those of C. chinensis females, decreased when the females were kept with heterospecific males. Fecundities of females of both species decreased as the number of heterospecific males increased. In contrast, resource competition at the larval stage resulted in higher survival of C. maculatus than of C. chinensis. 4.,These results suggest that the positive frequency-dependent effect of reproductive interference resulted in species exclusion, depending on the initial population ratio of the two species, and the asymmetry of the interference resulted in C. chinensis being dominant in this study, as in previous studies. Classical competition studies should be reviewed in light of this evidence for reproductive interference. [source] Characterization of QoI resistance in Botrytis cinerea and identification of two types of mitochondrial cytochrome b genePLANT PATHOLOGY, Issue 1 2009S. Banno Botrytis cinerea field isolates collected in Japan were screened for resistance to Qo inhibitor fungicides (QoIs). Of the 198 isolates screened, six grew well on a medium containing azoxystrobin, a QoI, when salicylhydroxamic acid, an alternative oxidase inhibitor, was present. The resistance mutation in the cytochrome b gene (cytb) was characterized. All QoI-resistant isolates had the same mutation (GGT to GCT) in cytb that led to the substitution of glycine by alanine at position 143 of cytochrome b, which is known to confer QoI resistance in plant pathogens. To detect this mutation, a hybridization probe assay based on real-time PCR amplification and melting curve analysis was developed. Using DNA samples prepared from aubergines coinfected with QoI-resistant and QoI-sensitive B. cinerea isolates, two similar peak profiles with their corresponding melting temperatures were obtained. This result suggests that QoI-resistant and QoI-sensitive isolates may compete equally in terms of pathogenicity, and the assay may be used to assess the population ratio of mutant and wild-type isolates. However, the hybridization probe did not anneal to PCR products derived from the DNA samples of some QoI-sensitive isolates. Structural analysis of cytb revealed that B. cinerea field isolates could be classified into two groups: one with three introns and the other with an additional intron (Bcbi-143/144 intron) inserted between the 143rd and 144th codons. All 88 isolates possessing the Bcbi-143/144 intron were azoxystrobin-sensitive, suggesting that the QoI-resistant mutation at codon 143 in cytb prevents self-splicing of the Bcbi-143/144 intron, as proposed in some other plant pathogens. [source] Public sector refraction and spectacle dispensing in low-resource countries of the Western PacificCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 4 2008Jacqueline Ramke Abstract Background:, Given that uncorrected refractive error is a frequent cause of vision impairment, and that there is a high unmet need for spectacles, an appraisal of public sector arrangements for the correction of refractive error was conducted in eight Pacific Island countries. Methods:, Mixed methods (questionnaire and semi-structured interviews) were used to collect information from eye care personnel (from Fiji, Papua New Guinea, Solomon Islands, Vanuatu, Cook Islands, Samoa, Tonga and Tuvalu) attending a regional eye health workshop in 2005. Results:, Fiji, Tonga and Vanuatu had Vision 2020 eye care plans that included refraction services, but not spectacle provision. There was wide variation in public sector spectacle dispensing services, but, except in Samoa, ready-made spectacles and a full cost recovery pricing strategy were the mainstay. There were no systems for the registration of personnel, nor guidelines for clinical or systems management. The refraction staff to population ratio varied considerably. Solomon Islands, Tuvalu and Vanuatu had the best coverage by services, either fixed or outreach. Most services had little promotional activity or community engagement. Conclusions:, To be successful, it would seem that public sector refraction services should answer a real and perceived need, fit within prevailing policy and legislation, value, train, retain and equip employees, be well managed, be accessible and affordable, be responsive to consumers, and provide ongoing good quality outcomes. To this end, a checklist to aid the initiation and maintenance of refraction and spectacle systems in low-resource countries has been constructed. [source] Solving nursing shortages: a common priorityJOURNAL OF CLINICAL NURSING, Issue 24 2008James Buchan Aims and objectives., This paper provides a context for this special edition. It highlights the scale of the challenge of nursing shortages, but also makes the point that there is a policy agenda that provides workable solutions. Results., An overview of nurse:population ratios in different countries and regions of the world, highlighting considerable variations, with Africa and South East Asia having the lowest average ratios. The paper argues that the ,shortage' of nurses is not necessarily a shortage of individuals with nursing qualifications, it is a shortage of nurses willing to work in the present conditions. The causes of shortages are multi-faceted, and there is no single global measure of their extent and nature, there is growing evidence of the impact of relatively low staffing levels on health care delivery and outcomes. The main causes of nursing shortages are highlighted: inadequate workforce planning and allocation mechanisms, resource constrained undersupply of new staff, poor recruitment, retention and ,return' policies, and ineffective use of available nursing resources through inappropriate skill mix and utilisation, poor incentive structures and inadequate career support. Conclusions., What now faces policy makers in Japan, Europe and other developed countries is a policy agenda with a core of common themes. First, themes related to addressing supply side issues: getting, keeping and keeping in touch with relatively scarce nurses. Second, themes related to dealing with demand side challenges. The paper concludes that the main challenge for policy makers is to develop a co-ordinated package of policies that provide a long term and sustainable solution. Relevance to clinical practice., This paper highlights the impact that nursing shortages has on clinical practice and in health service delivery. It outlines scope for addressing shortage problems and therefore for providing a more positive staffing environment in which clinical practice can be delivered. [source] National Health Service Corps Staffing and the Growth of the Local Rural Non-NHSC Primary Care Physician WorkforceTHE JOURNAL OF RURAL HEALTH, Issue 4 2006Donald E. Pathman MD ABSTRACT:,Context: Beyond providing temporary staffing, National Health Service Corps (NHSC) clinicians are believed by some observers to contribute to the long-term growth of the non-NHSC physician workforce of the communities where they serve; others worry that NHSC clinicians compete with and impede the supply of other local physicians. Purpose: To assess long-term changes in the non-NHSC primary care physician workforce of rural underserved counties that have received NHSC staffing support relative to workforce changes in underserved counties without NHSC support. Methods: Using data from the American Medical Association and NHSC, we compared changes from 1981 to 2001 in non-NHSC primary care physician to population ratios in 2 subsets of rural whole-county health professional shortage areas: (1) 141 counties staffed by NHSC physicians, nurse practitioners, and/or physician assistants during the early 1980s and for many of the years since and (2) all 142 rural health professional shortage area counties that had no NHSC clinicians from 1979 through 2001. Findings: From 1981 to 2001, counties staffed by NHSC clinicians experienced a mean increase of 1.4 non-NHSC primary care physicians per 10,000 population, compared to a smaller, 0.57 mean increase in counties without NHSC clinicians. The finding of greater non-NHSC primary care physician to population mean ratio increase in NHSC-supported counties remained significant after adjusting for baseline county demographics and health care resources (P < .001). The estimated number of "extra" non-NHSC physicians in NHSC-supported counties in 2001 attributable to the NHSC was 294 additional physicians for the 141 supported counties, or 2 extra physicians, on average, for each NHSC-supported county. Over the 20 years, more NHSC-supported counties saw their non-NHSC primary care workforces grow to more than 1 physician per 3,500 persons, but no more NHSC-supported than nonsupported counties lost their health professional shortage area designations.Conclusions: These data suggest that the NHSC contributed positively to the non-NHSC primary care physician workforce in the rural underserved counties where its clinicians worked during the 1980s and 1990s. [source] | |||||||||||||