DO SPORTFISH CONSUMPTION ADVISORIES AFFECT RESERVOIR ANGLERS' SITE CHOICE?

Increasing numbers of freshwater ecosystems have had sportfish consumption advisories posted in recent years. Advisories are sometimes issued in lieu of environmental remediation if they are considered more cost-effective than "cleaning up" the resource, but this approach assumes that anglers adjust behavior in response to the warning. Previous studies, however, suggest that compliance with advisories can be quite low. In contrast, this study measures a statistically significant response by reservoir anglers to consumption advisories. In particular, anglers are less likely to choose to visit a reservoir with an advisory than a similar reservoir without an advisory. Furthermore, the economic losses due to advisories are quantified for anglers in two regions of Tennessee.Resource /Energy Economics and Policy,

The UK quality and outcomes framework pay-for-performance scheme and spirometry: rewarding quality or just quantity? A cross-sectional study in Rotherham, UK

Background: Accurate spirometry is important in the management of COPD. The UK Quality and Outcomes Framework pay-for-performance scheme for general practitioners includes spirometry related indicators within its COPD domain. It is not known whether high achievement against QOF spirometry indicators is associated with spirometry to BTS standards. Methods: Data were obtained from the records of 3,217 patients randomly sampled from 5,649 patients with COPD in 38 general practices in Rotherham, UK. Severity of airflow obstruction was categorised by FEV1 (% predicted) according to NICE guidelines. This was compared with clinician recorded COPD severity. The proportion of patients whose spirometry met BTS standards was calculated in each practice using a random sub-sample of 761 patients. The Spearman rank correlation between practice level QOF spirometry achievement and performance against BTS spirometry standards was calculated. Results: Spirometry as assessed by clinical records was to BTS standards in 31% of cases (range at practice level 0% to 74%). The categorisation of airflow obstruction according to the most recent spirometry results did not agree well with the clinical categorisation of COPD recorded in the notes (Cohen's kappa = 0.34, 0.30 - 0.38). 12% of patients on COPD registers had FEV1 (% predicted) results recorded that did not support the diagnosis of COPD. There was no association between quality, as measured by adherence to BTS spirometry standards, and either QOF COPD9 achievement (Spearman's rho = -0.11), or QOF COPD10 achievement (rho = 0.01). Conclusion: The UK Quality and Outcomes Framework currently assesses the quantity, but not the quality of spirometry

Artificial evolution with Binary Decision Diagrams: a study in evolvability in neutral spaces

This thesis develops a new approach to evolving Binary Decision Diagrams, and uses it to study evolvability issues. For reasons that are not yet fully understood, current approaches to artificial evolution fail to exhibit the evolvability so readily exhibited in nature. To be able to apply evolvability to artificial evolution the field must first understand and characterise it; this will then lead to systems which are much more capable than they are currently. An experimental approach is taken. Carefully crafted, controlled experiments elucidate the mechanisms and properties that facilitate evolvability, focusing on the roles and interplay between neutrality, modularity, gradualism, robustness and diversity. Evolvability is found to emerge under gradual evolution as a biased distribution of functionality within the genotype-phenotype map, which serves to direct phenotypic variation. Neutrality facilitates fitness-conserving exploration, completely alleviating local optima. Population diversity, in conjunction with neutrality, is shown to facilitate the evolution of evolvability. The search is robust, scalable, and insensitive to the absence of initial diversity. The thesis concludes that gradual evolution in a search space that is free of local optima by way of neutrality can be a viable alternative to problematic evolution on multi-modal landscapes

Nonmarket valuation of the University of Tennessee Arboretum

Many studies have estimated demand functions for visits to recreation sites. Several included commonly defined recreation-based areas such as beaches, parks, lakes and rivers but excluded examination of horticulturally significant sites such as botanic gardens and arboreta. This study estimates user-demand and consumer surplus for visits to the University of Tennessee Arboretum by the travel cost method using maximum likelihood estimation techniques. Results suggest that travel cost and income of consumers are important determinants of demand, at least in the case of visits to the University of Tennessee Arboretum, and that consumer-use value may be derived from this demand

Changes in and predictors of length of stay in hospital after surgery for breast cancer between 1997/98 and 2004/05 in two regions of England: a population-based

BACKGROUND Decreases in length of stay (LOS) in hospital after breast cancer surgery can be partly attributed to the change to less radical surgery, but many other factors are operating at the patient, surgeon and hospital levels. This study aimed to describe the changes in and predictors of length of stay (LOS) in hospital after surgery for breast cancer between 1997/98 and 2004/05 in two regions of England. METHODS Cases of female invasive breast cancer diagnosed in two English cancer registry regions were linked to Hospital Episode Statistics data for the period 1st April 1997 to 31st March 2005. A subset of records where women underwent mastectomy or breast conserving surgery (BCS) was extracted (n = 44,877). Variations in LOS over the study period were investigated. A multilevel model with patients clustered within surgical teams and NHS Trusts was used to examine associations between LOS and a range of factors. RESULTS Over the study period the proportion of women having a mastectomy reduced from 58% to 52%. The proportion varied from 14% to 80% according to NHS Trust. LOS decreased by 21% from 1997/98 to 2004/05 (LOSratio = 0.79, 95%CI 0.77-0.80). BCS was associated with 33% shorter hospital stays compared to mastectomy (LOSratio = 0.67, 95%CI 0.66-0.68). Older age, advanced disease, presence of comorbidities, lymph node excision and reconstructive surgery were associated with increased LOS. Significant variation remained amongst Trusts and surgical teams. CONCLUSION The number of days spent in hospital after breast cancer surgery has continued to decline for several decades. The change from mastectomy to BCS accounts for only 9% of the overall decrease in LOS. Other explanations include the adoption of new techniques and practices, such as sentinel lymph node biopsy and early discharge. This study has identified wide variation in practice with substantial cost implications for the NHS. Further work is required to explain this variation

Challenges faced by cocoyam farmers in adapting to climate change in Southeast Nigeria

The study examined the challenges faced by cocoyam farmers in adapting to climate change in Southeast, Nigeria. Three hundred and eighty-four respondents selected through multi-stage sampling technique were used for the study. Data were collected using structured questionnaire and interview schedule and analysed using both descriptive and inferential statistical tools. Findings showed that majority were females (67%), married (92%) and maintain average household size of 6 persons and a mean age of 51 years. They were mainly primary (32%) and secondary (34%) school certificate holders with farming (77%) as their major occupation. The major cropping pattern practiced was mixed farming with cassava (63%) and maize (58%) as the major crops cultivated by the farmers. Majority of the farmers owned farms of one hectare and below accessed mainly through inheritance (76%) and labour sourced mainly through hiring (50%). Most (81%) of the farmers have spent more than ten years in farming. Climate change information was accessed mainly through their personal experience (64%), radio (42%) and fellow villagers (39%). The study identified eight major challenges faced by cocoyam farmers in adapting to climate change namely Lack/high cost of farm inputs and low soil fertility (Factor 1), Land and labour constraints (Factor 2), Poor access to information and ineffectiveness of cooperatives (Factor 3), lack of/poor access to fund and credit facilities and poor government support (Factor 4), lack of improved varieties of cocoyam (factor 5), poor value attached to cocoyam (Factor 6), poor infrastructural capacity and technology know-how (Factor 7) and Transportation constraint (Factor 8). Analysis of variance identified significant variations in the challenges faced by cocoyam farmers in the study area. The study recommends enrollment in cooperatives and revitalizing existing cooperatives, re-orientation of farmers on the benefits of cocoyam and increased used of climate change information sharing using mobile phones as possible ways of alleviating the challenges

Early pubertal onset and its relationship with sexual risk taking, substance use and anti-social behaviour: a preliminary cross-sectional study

<p>Abstract</p> <p>Background</p> <p>In many countries age at pubertal onset has declined substantially. Relatively little attention has been paid to how this decline may affect adolescent behaviours such as substance use, violence and unprotected sex and consequently impact on public health.</p> <p>Methods</p> <p>In the UK, two opportunistic samples (aged 16-45 years), paper-based (n = 976) and online (n = 1117), examined factors associated with earlier pubertal onset and whether earlier age of onset predicted sexual risk-taking, substance use and anti-social behaviours during early adolescence.</p> <p>Results</p> <p>Overall, 45.6% of females reported menarche ≤ 12 years and 53.3% of males were categorised as having pubertal onset ≤ 11 years. For both sexes earlier pubertal onset was associated with poorer parental socio-economic status. Other pre-pubertal predictors of early onset were being overweight, more childhood illnesses (females) and younger age at time of survey (males). For both sexes earlier puberty predicted having drunk alcohol, been drunk, smoked and used drugs <14 years as well as having a sexual debut and unprotected sex <16 years. Males with earlier pubertal onset were more likely to report fighting and aggressive responses to emotional upset during early adolescence while females were more likely to report being bullied and having taken more time off school.</p> <p>Conclusion</p> <p>Results provide sufficient evidence for changes in age of pubertal onset to be further explored as a potential influence on trends in adolescent risk behaviours. Further insight into the relationship between early puberty and both obesity and socio-economic status may help inform early interventions to tackle the development of risk behaviours and health inequalities during early adolescence.</p

Methyl mercury dynamics in a tidal wetland quantified using in situ optical measurements

Author Posting. © American Society of Limnology and Oceanography, 2011. This article is posted here by permission of American Society of Limnology and Oceanography for personal use, not for redistribution. The definitive version was published in Limnology and Oceanography 56 (2011): 1355-1371, doi:10.4319/lo.2011.56.4.1355.We assessed monomethylmercury (MeHg) dynamics in a tidal wetland over three seasons using a novel method that employs a combination of in situ optical measurements as concentration proxies. MeHg concentrations measured over a single spring tide were extended to a concentration time series using in situ optical measurements. Tidal fluxes were calculated using modeled concentrations and bi-directional velocities obtained acoustically. The magnitude of the flux was the result of complex interactions of tides, geomorphic features, particle sorption, and random episodic events such as wind storms and precipitation. Correlation of dissolved organic matter quality measurements with timing of MeHg release suggests that MeHg is produced in areas of fluctuating redox and not limited by buildup of sulfide. The wetland was a net source of MeHg to the estuary in all seasons, with particulate flux being much higher than dissolved flux, even though dissolved concentrations were commonly higher. Estimated total MeHg yields out of the wetland were approximately 2.5 µg m−2 yr−1—4–40 times previously published yields—representing a potential loading to the estuary of 80 g yr−1, equivalent to 3% of the river loading. Thus, export from tidal wetlands should be included in mass balance estimates for MeHg loading to estuaries. Also, adequate estimation of loads and the interactions between physical and biogeochemical processes in tidal wetlands might not be possible without long-term, high-frequency in situ measurements.This work was supported by funding from the California Bay Delta Authority Ecosystem Restoration and Drinking Water Programs (grant ERP-00-G01) and matching funds from the U.S. Geological Survey Cooperative Research Program