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Level Approach (level + approach)
Selected AbstractsAn evaluation of logistic regression models for predicting amphipod toxicity from sediment chemistryENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2005Jeffrey D. Wetherington Abstract An empirical screening level approach was developed to assess the probability of toxicity to benthic organisms associated with contaminated sediment exposure. The study was based on simple logistic regression models (LRMs) of matching sediment chemistry and toxicity data retrieved from a large database of field-collected sediment samples contaminated with multiple chemicals. Three decisions were made to simplify the application of LRMs to sediment samples contaminated with multiple chemicals. First, percent mortality information associated with each sediment sample was condensed into a dichotomous response (i.e., toxic or nontoxic). Second, each LRM assumed that toxicity was attributable to a single contaminant. Third, individual contaminants present at low concentrations were excluded from toxic sediment samples. Based on an analysis of the National Sediment Inventory database, the LRM approach classified 55% of nontoxic sediments as toxic (i.e., false-positives). Because this approach has been used to assess the probability of benthic toxicity as reported by the U.S. Environmental Protection Agency (U.S. EPA), the resultant estimates of potential toxicity convey a misleading impression of the increased hazard that sediments pose to the health of aquatic organisms at many sites in the United States. This could result in important resources needlessly being diverted from truly contaminated sites to evaluate and possibly remediate sediments at uncontaminated sites. [source] Propagation of drought through groundwater,a new approach using linear reservoir theoryHYDROLOGICAL PROCESSES, Issue 15 2003E. Peters Abstract The effect of drought on groundwater heads and discharge is often complex and poorly understood. Therefore the propagation of a drought from groundwater recharge to discharge and the influence of aquifer characteristics on the propagation was analysed by tracking a drought in recharge through a linear reservoir. The recharge was defined as a sinusoid function with a period of 1 year. The decrease in recharge owing to drought was simulated by multiplying the recharge during 1 year with a drought fraction between 0 and 1, which represents a decrease in the recharge of 100 to 0%, respectively. The droughts were identified using the threshold level approach, with a threshold that is constant in time. For this case analytical formulations were derived, which express the drought duration and deficit in the groundwater discharge in terms of the decrease in recharge, the reservoir coefficient that characterizes aquifer properties and the height of the threshold level. The results showed that the delay in the groundwater system caused a shift of the main part of the decrease in recharge from the high-flow to the low-flow period. This resulted in an increase in drought deficit for discharge compared with the drought deficit for recharge. Also the development of multiyear droughts caused an increase in drought deficit. The attenuation in the groundwater system caused a decrease in drought deficit. In most cases the net effect of these processes was an increase of drought deficit as a result of the propagation through groundwater. Only for small droughts the deficit decreased from recharge to discharge. The amount of increase or decrease depends on the reservoir coefficient and the severity of the drought. Under most conditions a maximum in the drought deficit occurred for a reservoir coefficient of around 200 days. Copyright © 2003 John Wiley & Sons, Ltd. [source] Conservation implications of rainforest use patterns: mature forests provide more resources but secondary forests supply more medicineJOURNAL OF APPLIED ECOLOGY, Issue 6 2009Michael C. Gavin Summary 1.,Tropical rainforests are a global conservation priority. Robust arguments supporting rainforest conservation can attract funding and shape land-use management. However, some popular assertions regarding the value of tropical forests remain largely untested. 2.,This study tests the validity of two arguments in support of mature tropical rainforest conservation: first, that these forests should be conserved based on their value as potential sources of medicine. This argument requires mature forests to be better sources of medicine than alternative land-use types, including secondary forests. Second, secondary forest use may help conserve mature forests by providing sufficient resources to buffer against resource extraction in mature forests. 3.,The research was conducted in three communities in the Cordillera Azul, Peru, where 369 individuals from 66 households were surveyed. Participants recorded all flora and fauna collected in mature (>20 years) and secondary forests over 180 days in six use categories (food, medicine, wood, weavings, adornments and ,other'). Ecological knowledge of secondary and mature forest species was assessed for male and female household heads. 4.,Households used 346 folk species (as defined by local classification systems) from 3668 collection events. Individuals had better knowledge of secondary forest species, but more access to mature forests. Participants collected significantly more medicines from secondary than from mature forests. In other major use categories (food, wood, weaving, adornment), secondary forests provided fewer resources than mature forests. Participants collected a different set of species from secondary and mature forests, with only 130 folk species (38%) collected in both secondary and mature forests. 5.,Synthesis and applications. The arguments to protect mature rainforests as sources of new drugs may be overstated, because secondary forests can provide more medicinal plant resources than mature forests, and landscapes that incorporate forests of different ages can maximize availability of medicinal plant species. Conservation efforts must take a landscape level approach given the spread of resource use across different forest types. Because of the heterogeneity of resource availability and use among community members, and the dynamic nature of resource use on forest frontiers, conservation should embrace participatory adaptive management approaches that incorporate a variety of resource users. [source] Social capital, age and religiosity in people who are lonelyJOURNAL OF CLINICAL NURSING, Issue 3 2006William Lauder PhD Aims and objectives., The aims of the study were to (i) investigate age and loneliness, (ii) investigate the association between religiosity and loneliness, and (iii) and explore the relationship between social capital and loneliness. Background., Loneliness is the subjective experience of social isolation and is a risk factor for a wide range of health problems including heart disease and depression. Poor self-rated health, domestic violence and poor economic conditions are associated with greater loneliness. Design., The study was a cross-sectional survey of a random sample of adults aged 18 years and over. Methods., A random sample of 1289 subjects was interviewed by computer-assisted telephone interviewing. This interview included the Loneliness Scale and items from the Social Capital Module of the General Household Survey. Findings., Loneliness is more common in men and people without strong religious beliefs. An income-loneliness gradient is evident. Little support was found for the association between social capital and loneliness. Conclusion., The prevalence of loneliness is relatively stable in this population. Loneliness is linked to income and unemployment and as such pathways between socio-economic factors, loneliness and health need to guide interventions and future research. Relevance to clinical practice., Loneliness is linked to a range of social and economic factors. Current Health Visiting practice recognizes the importance of tackling the effects of poverty and social deprivation and places community building at the core of much Health Visiting practice. This broad community level approach can usefully transfer into all community nursing and health promotion activity. [source] Constraints to expanding access to health interventions: an empirical analysis and country typologyJOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 1 2003M. Kent Ranson This paper adopts three approaches to classifying countries by level of constraint, in order to inform the choice of strategies for expanding access to health interventions in different contexts. We find substantial heterogeneity across the 84 low-income and (all) sub-Saharan African countries analysed. Poor sub-Saharan African countries are the most highly constrained; Asian countries, in general, less constrained; and the two Asian giants, China and India, consistently fall above the median. Former Soviet Union countries rank low in terms of governance, but high for health systems variables. Only 10 per cent of the total population of the countries included lives in countries with the greatest constraints. The potential applications of the analysis are discussed, as are the limitations of the cross-sectional, macro level approach. Copyright © 2003 John Wiley & Sons, Ltd. [source] A cellular level approach to predicting resting energy expenditure: Evaluation of applicability in adolescents,AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2010ZiMian Wang We previously derived a cellular level approach for a whole-body resting energy expenditure (REE) prediction model by using organ and tissue mass measured by magnetic resonance imaging (MRI) combined with their individual cellularity and assumed stable-specific resting metabolic rates. Although this approach predicts REE well in both young and elderly adults, there were no studies in adolescents that specifically evaluated REE in relation to organ,tissue mass. It is unclear whether the approach can be applied to rapidly growing adolescents. The aim of the present study was to evaluate the applicability of the previous developed REE prediction model in adolescents, and to compare its applicability in young and elderly adults. Specifically, we tested the hypothesis that measured REE can be predicted from a combination of individual organ and tissue mass and their related cellularity. This was a 2-year longitudinal investigation. Twenty healthy male subjects with a mean age of 14.7 years had REE, organ and tissue mass, body cell mass, and fat-free mass (FFM) measured by indirect calorimetry, whole-body MRI, whole-body 40K counting and dual-energy X-ray absorptiometry, respectively. The predicted REE (REEp; mean ± SD, 1,487 ± 238 kcal/day) was correlated with the measured REE (REEm, 1,606 ± 237 kcal/day, r = 0.76, P < 0.001). The mean difference (118 ± 165 kcal/day) between REEm and REEp was significant (P = 0.0047), accounting for 7.3% of REEm for the entire group. The present study, the first of its type in adolescents, does not support the applicability of the organ,tissue-based REE prediction model during rapid adolescent growth. A modified general REE prediction model is thus suggested which may account for the higher REE/FFM ratio observed in adolescents. Am. J. Hum. Biol. 2010. © 2010 Wiley-Liss, Inc. [source] Pulsatile In Vitro Simulation of the Pediatric Univentricular Circulation for Evaluation of Cardiopulmonary Assist ScenariosARTIFICIAL ORGANS, Issue 11 2009Onur Dur Abstract The characteristic depressed hemodynamic state and gradually declining circulatory function in Fontan patients necessitates alternative postoperative management strategies incorporating a system level approach. In this study, the single-ventricle Fontan circulation is modeled by constructing a practical in vitro bench-top pulsatile pediatric flow loop which demonstrates the ability to simulate a wide range of clinical scenarios. The aim of this study is to illustrate the utility of a novel single-ventricle flow loop to study mechanical cardiac assist to Fontan circulation to aid postoperative management and clinical decision-making of single ventricle patients. Two different pediatric ventricular assist devices, Medos and Pediaflow Gen-0, are anastomosed in two nontraditional configurations: systemic venous booster (SVB) and pulmonary arterial booster (PAB). Optimum ventricle assist device strategy is analyzed under normal and pathological (pulmonary hypertension) conditions. Our findings indicate that the Medos ventricular assist device in SVB configuration provided the highest increase in pulmonary (46%) and systemic (90%) venous flow under normal conditions, whereas for the hypertensive condition, highest pulmonary (28%) and systemic (55%) venous flow augmentation were observed for the Pediaflow ventricular assist device inserted as a PAB. We conclude that mechanical cardiac assist in the Fontan circulation effectively results in flow augmentation and introduces various control modalities that can facilitate patient management. Assisted circulation therapies targeting single-ventricle circuits should consider disease state specific physiology and hemodynamics on the optimal configuration decisions. [source] Ecological tax reform,a value chain level approachBUSINESS STRATEGY AND THE ENVIRONMENT, Issue 3 2002Lassi Linnanen This study assesses the effects of an ecological tax reform on three value chains. These case studies lead to an analysis of the business strategy options when companies face a shift in the relative prices of their production factors. The results support earlier research findings that the direct effects of an ecological tax reform on the price competitiveness of companies is on average rather small. However, the effects of the reform are shown to vary significantly between the different parts of the value chain. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment [source] Towards integrated paediatric services in the Netherlands: a survey of views and policies on collaboration in the care for children with cerebral palsyCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 5 2007B. J. G. Nijhuis Abstract Aim, Worldwide, family-centred and co-ordinated care are seen as the two most desirable and effective methods of paediatric care delivery. This study outlines current views on how team collaboration comprising professionals in paediatric rehabilitation and special education and the parents of children with disabilities should be organized, and analyses the policies of five paediatric rehabilitation settings associated with the care of 44 children with cerebral palsy (CP) in the Netherlands. Methods, For an overview of current ideas on collaboration, written statements of professional associations in Dutch paediatric rehabilitation were examined. The policy statements of the five participating settings were derived from their institutional files. Documents detailing the collaborative arrangements involving the various professionals and parents were evaluated at the institutional level and at the child level. Involvement of the stakeholders was analysed based on team conferences. Results, Also in the Netherlands collaboration between rehabilitation and education professionals and parents is endorsed as the key principle in paediatric rehabilitation, with at its core the team conference in which the various priorities and goals are formulated and integrated into a personalized treatment plan. As to their collaborative approaches between rehabilitation centre and school, the five paediatric settings rarely differed, but at the child level approaches varied. Teams were large (averaging 10.5 members), and all three stakeholder groups were represented, but involvement differed per setting, as did the roles and contributions of the individual team members. Conclusion, Collaboration between rehabilitation and education professionals and parents is supported and encouraged nationwide. Views on collaboration have been formulated, and general guidelines on family-centred and co-ordinated care are available. Yet, collaborative practices in Dutch paediatric care are still developing. Protocols that carefully delineate the commitments to collaborate and that translate the policies into practical, detailed guidelines are needed, as they are a prerequisite for successful teamwork. [source] | ||||||||||||||||