Home About us Contact
|
Home About us Contact | ||
|
|
||
Population Greater (population + greater)
Selected AbstractsHost shifting by Operophtera brumata into novel environments leads to population differentiation in life-history traitsECOLOGICAL ENTOMOLOGY, Issue 5 2003Adam J. Vanbergen Abstract., 1. Operophtera brumata L. (Lepidoptera: Geometridae), a polyphagous herbivore usually associated with deciduous trees such as oak Quercus robur L., has expanded its host range to include the evergreen species heather Calluna vulgaris (L.) Hull and, most recently, Sitka spruce Picea sitchensis (Bong.) Carrière. 2. Phenology, morphology, and survival of O. brumata were measured at several life-history stages in populations from the three different host plant communities sampled from a range of geographical locations. The data were used to test for population differences, reflecting the marked differences in host-plant secondary chemistry, growth form, and site factors such as climate. The hypothesis that spruce-feeding populations originated from populations feeding on moorland, commonly sites of coniferous afforestation, was also tested. 3. Altitude, not host plant species, was the major influence on the timing of adult emergence. An effect of insect population independent of altitude was found, implying that additional unidentified factors contribute to this phenological variation. Larval survival and adult size varied between populations reared on different host plant species. Survival of larvae was affected negatively when reared on the novel host plant, Sitka spruce, versus the natal plant (oak or heather) but oak and heather-sourced insects did not differ in survivorship on Sitka spruce. 4. Host range extension into novel environments has resulted in population differentiation to the local climate, demonstrating that host shifts pose challenges to the herbivore population greater than those offered by the host plant alone. The hypothesis that Sitka spruce feeding populations have arisen predominantly from moorland feeding populations was not supported. [source] Provision of radical pelvic urological surgery in England, and compliance with improving outcomes guidanceBJU INTERNATIONAL, Issue 10 2009Erik K. Mayer OBJECTIVE To investigate compliance with Improving Outcomes Guidance (IOG) for radical pelvic surgery in England, and explore the pattern of service provision for radical cystectomy (RC) and radical prostatectomy (RP) before and after the introduction of IOG. METHODS For the period 2000/01,2006/07, all admissions for RC and RP were extracted from Hospital Episode Statistics (HES). At the institutional level, the numbers of RC and RP cases were combined to assess adherence to IOG. The IOG catchment populations for each institution were calculated by linking HES data to census ward population data. The pattern of service provision for RC and RP was independently assessed by assigning institutions into low-, medium- and high-volume groups of roughly equal volumes a priori, based on the ascending order of annual RC or RP rate, respectively. For RC it was also possible to explore the between-institution referral activity for RC by identifying the ,final endoscopic bladder procedure' that occurred immediately before the RC for each patient. This gave an indication of where the diagnosis and decision for RC had been made. RESULTS The percentage of institutions achieving the recommended IOG minimal case volume of 50 per year increased significantly between 2000/01 and 2006/07 (36% in odds per year, P < 0.001; odds ratio 1.36, 95% confidence interval 1.24,1.50), although absolute numbers remained relatively low (34% in 2006/07). Only one institution had a catchment population greater than the recommended 1 million. The total number of institutions performing RC decreased significantly over the years (P = 0.03), whereas for RP the decrease was not significant (P = 0.6). The decrease reflected a decline in the number of low-volume institutions, both for RC and RP, although this decline was not more than expected by chance. There had been a significant increase in the percentage of patients referred to another provider for their RC, from 5.5% in 2000/01 to 19.6% in 2006/07 (28% rise in odds per year, P < 0.001: odds ratio 1.28, 95% confidence interval 1.23,1.33). CONCLUSION There was evidence of centralization of radical pelvic urological surgery, although it is only relatively recently that this seems to have taken place with any certainty. The absolute numbers of providers achieving the IOG minimum caseload standard was relatively low. What impact this has had, if any, on the quality of patient care is yet to be fully determined. [source] FUNDING COMMUNITY POLICING TO REDUCE CRIME: HAVE COPS GRANTS MADE A DIFFERENCE?,CRIMINOLOGY AND PUBLIC POLICY, Issue 1 2002JIHONG "SOLOMON" ZHAO Research Summary: This research examines how funding from the U.S. Department of Justice, Office of Community Oriented Policing Services (COPS), has affected violent and property crime rates in the United States from 1995 to 1999. Drawing on six years of panel data, we examine the effects of three types of awards made by COPS to 6,100 law enforcement agencies serving more than 145 million citizens. We estimate their impact on crime reduction over time in jurisdictions receiving funding and controlling for baseline levels of crime, socioeconomic characteristics, city size, and population diversity and mobility. Our analyses suggest that COPS hiring and innovative grant programs have resulted in significant reductions in local crime rates in cities with populations greater than 10,000 for both violent and nonviolent offenses. Multivariate analysis shows that in cities with populations greater than 10,000, an increase in one dollar of hiring grant funding per resident contributed to a corresponding decline of 5.26 violent crimes and 21.63 property crimes per 100,000 residents. Similarly, an increase in one dollar of innovative grant funding per resident has contributed to a decline of 12.93 violent crimes and 45.53 property crimes per 100,000 persons. In addition, the findings suggest that COPS grants have had no significant negative effect on violent and property crime rates in cities with less than 10,000 population. Policy Implications: The findings of this study imply that COPS program funding to medium- and large-size cities has been an effective force in reducing both violent and property crime. Federal government grants made directly to law enforcement agencies to hire additional officers and promote innovations may be an effective way to reduce crime on a national scale. [source] Redrawing organ distribution boundaries: Results of a computer-simulated analysis for liver transplantationLIVER TRANSPLANTATION, Issue 8 2002Richard B. Freeman MD For several years, the Organ Procurement and Transplantation Network/United Network for Organ Sharing (UNOS) Liver and Intestinal Transplantation Committee has been examining effects of changes and proposed changes to the liver allocation system. The Institute of Medicine recently recommended that the size of liver distribution units be increased to improve the organ distribution system. Methods to achieve this and the potential impact on patients and transplant centers of such a change are evaluated in this study. In hypothetical scenarios, we combined geographically contiguous organ procurement organizations (OPOs) in seven different configurations to increase the size of liver distribution units to cover populations greater than 9 million persons. Using the UNOS Liver Allocation Model (ULAM), we examined the effect of 17 different organ allocation sequences in these proposed realignments and compared them with those predicted by ULAM for the current liver distribution system by using the following primary outcome variables: number of primary liver transplantations performed, total number of deaths, and total number of life-years saved. Every proposed new liver distribution unit plan resulted in fewer primary transplantations. Many policies increased the total number of deaths and reduced total life-years saved compared with the current system. Most of the proposed plans reduced interregional variation compared with the current plan, but no one plan consistently reduced variation for all outcome variables, and all reductions in variations were relatively small. All new liver distribution unit plans led to significant shifts in the number of transplantations performed in individual OPOs compared with the current system. The ULAM predicts that changing liver distribution units to larger geographic areas has little positive impact on overall results of liver transplantation in the United States compared with the current plan. Enlarging liver distribution units likely will result in significant shifts in organs across current OPO boundaries, which will have a significant impact on the activity of many transplant centers. [source] | ||||||||||