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Selected AbstractsNovel ecosystems: theoretical and management aspects of the new ecological world orderGLOBAL ECOLOGY, Issue 1 2006Richard J. Hobbs ABSTRACT We explore the issues relevant to those types of ecosystems containing new combinations of species that arise through human action, environmental change, and the impacts of the deliberate and inadvertent introduction of species from other regions. Novel ecosystems (also termed ,emerging ecosystems') result when species occur in combinations and relative abundances that have not occurred previously within a given biome. Key characteristics are novelty, in the form of new species combinations and the potential for changes in ecosystem functioning, and human agency, in that these ecosystems are the result of deliberate or inadvertent human action. As more of the Earth becomes transformed by human actions, novel ecosystems increase in importance, but are relatively little studied. Either the degradation or invasion of native or ,wild' ecosystems or the abandonment of intensively managed systems can result in the formation of these novel systems. Important considerations are whether these new systems are persistent and what values they may have. It is likely that it may be very difficult or costly to return such systems to their previous state, and hence consideration needs to be given to developing appropriate management goals and approaches. [source] A PRACTICAL GUIDE FOR THE DEVELOPMENT OF A WETLAND ASSESSMENT METHOD: THE CALIFORNIA EXPERIENCE,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2006Martha A. Sutula ABSTRACT: Wetland rapid assessment methods (RAMs) can provide a cost effective, scientifically defensible estimate of wetland and riparian condition for use in ambient and project monitoring in resource management and regulatory programs. Those who have chosen to develop a RAM to assess wetland and riparian condition are faced with a range of issues and important choices that they must make throughout the development process. This paper is intended as a practical guide to RAM development. Six basic stages in the RAM development process are discussed: (1) organize RAM development by identifying the intended applications, assessment endpoints, and geographic scope of the RAM and forming appropriate teams to advise and review the development process and its products; (2) build a scientific foundation for method development by conducting a literature review, choosing a wetland classification system, building conceptual models, and identifying the major assumptions underlying the model; (3) assemble the method as a system of attributes and metrics that describe a full range of conditions; (4) verify the ability of the method to distinguish between wetlands along a continuum of conditions; (5) calibrate and validate the method against sets of quantitative data representing more intensive measures of wetland condition; and (6) implement the method through outreach and training of the intended users. Important considerations within each of these stages lead to choices in accuracy, precision, robustness, ease of use, and cost. These are identified and the tradeoffs of the various options discussed. Experience with the ongoing development and implementation of the California Rapid Assessment Method (CRAM) is used to illustrate these stages and associated choices in RAM development. [source] Comparison of diagnostic accuracy for cutaneous malignant melanoma between general dermatology, plastic surgery and pigmented lesion clinicsBRITISH JOURNAL OF DERMATOLOGY, Issue 2 2003J.E. Osborne SummaryBackground Since the 1980s there have been dedicated pigmented lesion clinics (PLCs) in the U.K. Important considerations when comparing the efficacy of the PLC with other referral clinics include diagnostic accuracy. Objectives To compare the false-negative rate of clinical diagnosis (FNR) in the PLC with that in the other clinics of primary referral of malignant melanoma (MM) in the same geographical area. We have previously shown that certain clinical features are risk factors for diagnostic failure of MM. A further aim of this study was to correct for any differences in frequency of these factors in the melanoma populations between clinics and to estimate the false-positive diagnostic rate (FPR) in the PLC. Methods To compare the FNR between clinics, the case notes of all patients presenting with histologically proven cutaneous MM in Leicestershire between 1987 and 1997 were examined retrospectively. A false-negative diagnosis was defined as documentation of another diagnosis and/or evidence in the case notes that the diagnosis was not considered to be MM. The FNR was estimated as the number of false-negative clinical diagnoses/number of true-positive histological diagnoses. To estimate the diagnostic FPR, which was defined as the number of false-positive clinical diagnoses of MM/total number of positive clinical diagnoses, in the PLC, the outcome of 500 consecutive patients attending the PLC was surveyed. Results The case notes of 731 patients were available, of whom approximately two-thirds initially attended the PLC, one-fifth the General Dermatology clinics (D) and the remainder were divided approximately equally (one-twentieth each) between Plastic Surgery clinics (P), other clinics (O) and the surgery of the general practitioner (GP). The last was regarded as the primary referral clinic if the lesion were excised there prior to any referral. The FNR was lowest for the PLC, at 10%, compared with 29% (D), 19% (P), 55% (O) and 54% (GP) (P < 0·0001). Lesions with risk factors for diagnostic failure were under-represented in the PLC (P < 0·0001), the mean frequencies of the risk factors being 20% (PLC), 25% (D), 22% (P), 31% (O) and 30% (GP). Differences were not large but still could partially explain the lower FNR of the PLC. However, when the FNR was estimated for lesions exhibiting each of these risk factors, the PLC was found to have the lowest rate in every case (PLC vs. all clinics combined, P = 0·04 to P < 0·0001). The mean FNR for the risk factors combined was 18% (PLC), 45% (D), 50% (P), 68% (O) and 71% (GP). Also on logistic multivariable analysis of the PLC vs. all the other clinics on FNR and the above factors, the higher FNR of the other clinics retained significance (odds ratio 5·9, P < 0·0001). In the 500 patients surveyed separately in the PLC, the MM pick-up rate on biopsy was 32% and the diagnostic FPR was 41%. Conclusions The FNR of MM was lower in the PLC than in the other clinics, while the pick-up rate for MM on biopsy and the FPR were acceptably low. [source] Forest Stand Dynamics and Livestock Grazing in Historical ContextCONSERVATION BIOLOGY, Issue 5 2005MICHAEL M. BORMAN clima; incendio forestal; pastoreo histórico; pino ponderosa; supresión de fuego Abstract:,Livestock grazing has been implicated as a cause of the unhealthy condition of ponderosa pine forest stands in the western United States. An evaluation of livestock grazing impacts on natural resources requires an understanding of the context in which grazing occurred. Context should include timing of grazing, duration of grazing, intensity of grazing, and species of grazing animal. Historical context, when and under what circumstances grazing occurred, is also an important consideration. Many of the dense ponderosa pine forests and less-than-desirable forest health conditions of today originated in the early 1900s. Contributing to that condition was a convergence of fire, climate, and grazing factors that were unique to that time. During that time period, substantially fewer low-intensity ground fires (those that thinned dense stands of younger trees) were the result of reduced fine fuels (grazing), a substantial reduction in fires initiated by Native Americans, and effective fire-suppression programs. Especially favorable climate years for tree reproduction occurred during the early 1900s. Exceptionally heavy, unregulated, unmanaged grazing by very large numbers of horses, cattle, and sheep during the late nineteenth and early twentieth centuries occurred in most of the U.S. West and beginning earlier in portions of the Southwest. Today, livestock numbers on public lands are substantially lower than they were during this time and grazing is generally managed. Grazing then and grazing now are not the same. Resumen:,El pastoreo de ganado ha sido implicado como una causa de la mala salud de los bosques de pino ponderosa en el occidente de Estados Unidos. La evaluación de los impactos del pastoreo sobre los recursos naturales requiere de conocimiento del contexto en que ocurrió el pastoreo. El contexto debe incluir al período de ocurrencia, la duración y la intensidad del pastoreo, así como la especie de animal que pastoreó. El contexto histórico, cuando y bajo que circunstancias ocurrió el pastoreo, también es una consideración importante. Muchos de los bosques densos de pino ponderosa y de las condiciones, menos que deseables, de salud de los bosques actuales se originaron al principio del siglo pasado. Contribuyó a esa condición una convergencia de factores, fuego, clima y pastoreo, que fueron únicos en ese tiempo. Durante ese período, hubo sustancialmente menos incendios superficiales de baja intensidad (que afectaron a grupos densos de árboles más jóvenes) como resultado de la reducción de combustibles finos (pastoreo), una reducción sustancial en los incendios iniciados por Americanos Nativos y programas efectivos de supresión de incendios. Al inicio del siglo pasado hubo años con clima especialmente favorable para la reproducción de árboles. Al final del siglo diecinueve y comienzo del veinte hubo pastoreo no regulado ni manejado, excepcionalmente intensivo, por una gran cantidad de caballos, reses y ovejas en la mayor parte del oeste de E.U.A. y aun antes en porciones del suroeste. En la actualidad, el número de semovientes en terrenos públicos es sustancialmente menor al de ese tiempo, y el pastoreo generalmente es manejado. El pastoreo entonces y el pastoreo ahora no son lo mismo. [source] Monoclonal B cell lymphocytosis: Clinical and population perspectives,CYTOMETRY, Issue S1 2010Neil E. Caporaso Abstract Monoclonal B Cell Lymphocytosis (MBL) refers to clones of CLL-like cells that exhibit CLL characteristics that fall short of the numbers required for CLL diagnosis. Data from large CLL kindreds document increased prevalence of MBL suggesting a genetic contribution to its etiology. The molecular features that favor progression of MBL to CLL are poorly understood but an elevated B-cell count is a risk factor for progression. An important consideration when evaluating volunteers from CLL families who are willing to donate bone marrow is that MBL be ruled out since the MBL donor clone could result in a second CLL in the recipient. Further studies of MBL are needed to identify the molecular features and how they evolve during progression. Published 2010 Wiley-Liss, Inc. [source] Paper Versus Electronic Medical Records: The Effects of Access on Physicians' Decisions to Use Complex Information Technologies,DECISION SCIENCES, Issue 2 2009Virginia Ilie ABSTRACT This study examines physicians' responses to complex information technologies (IT) in the health care supply chain. We extend individual-level IT adoption models by incorporating a new construct: system accessibility. The main premise of the study is, when faced with a decision between alternate IT systems, individual users tend to select and make use of the technology or system that is most readily accessible. We discuss both physical and logical dimensions of accessibility as they relate to adoption of electronic medical records (EMR). Physical accessibility refers to the availability of computers that can be used to access EMR, while logical accessibility refers to the ease or difficulty of logging into the system. Using data from a survey of 199 physicians practicing in a large U.S. hospital, we show that, when deciding between the paper chart and EMR, accessibility is an important consideration in a physician's decision to use the system. Both dimensions of accessibility act as barriers to EMR use intentions through their indirect effect on physicians' perceptions of EMR usefulness and ease of use. Logical access also has a direct effect on EMR use intentions. We conclude that accessibility is an important factor that limits acceptance of complex IT such as EMR. [source] Low-fat oxidation may be a factor in obesity among men with schizophreniaACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2009J.-K. Sharpe Objective:, Obesity associated with atypical antipsychotic medications is an important clinical issue for people with schizophrenia. The purpose of this project was to determine whether there were any differences in resting energy expenditure (REE) and respiratory quotient (RQ) between men with schizophrenia and controls. Method:, Thirty-one men with schizophrenia were individually matched for age and relative body weight with healthy, sedentary controls. Deuterium dilution was used to determine total body water and subsequently fat-free mass (FFM). Indirect calorimetry using a Deltatrac metabolic cart was used to determine REE and RQ. Results:, When corrected for FFM, there was no significant difference in REE between the groups. However, fasting RQ was significantly higher in the men with schizophrenia than the controls. Conclusion:, Men with schizophrenia oxidised proportionally less fat and more carbohydrate under resting conditions than healthy controls. These differences in substrate utilisation at rest may be an important consideration in obesity in this clinical group. [source] Melatonin therapy for headache disordersDRUG DEVELOPMENT RESEARCH, Issue 6 2007Mario F.P. Peres Abstract Even though efficacy is often the most important consideration for patient preference in migraine prevention, currently available medications do not meet patient expectation. Efficacy is in the range of 50% reduction in migraine attacks in 50% of patients studied for the best medications. Therefore, new options for migraine treatment are needed. Melatonin has been considered a good candidate for migraine and other headaches prevention due to its favorable mechanisms of action and excellent tolerability profile. In this article, we review the putative role of the pineal gland and melatonin in migraine pathophysiology and treatment. Drug Dev Res 68:329,334, 2007. © 2007 Wiley-Liss, Inc. [source] Induction of cytochrome P4501A in African brown house snake (Lamprophis fuliginosus) primary hepatocytesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2006Markus Hecker Abstract Ahough there have been numerous sudies involving fish, birds, and mammals, little is known about the response of the cytochrome P4501A system of snakes to halogenated aromatic hydrocarbons (HAHs). The present study describes the induction of ethoxyresorufin- O -deethylase (EROD) in primary hepatocytes of the African brown house snake (Lamprophis fuliginosus). Hepatocytes were exposed in multiwell plates to 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) and four different non- ortho -substi-tuted coplanar polychlorinated biphenyls (PCBs 77, 81, 126, and 169). Exposure to TCDD and PCB 126 resulted in a dose-dependent increase in EROD activity, with maximum inducible EROD activities of 177 ± 56 (mean ± SEM) and 101.1 ± 55 pmol/min/mg protein for TCDD and PCB 126, respectively. None of the other PCBs caused a measurable induction of EROD, which suggests reduced inducibility of snake hepatocytes compared to some vertebrate taxa. Median effective concentrations (EC50s) were 0.16 ± 0.03 nM for TCDD and 8.25 ± 4.14 nM for PCB 126. The relative potency (REP20,80) range for PCB 126 was 0.044 to 0.046. Compared to results from in vitro systems using other vertebrate species, both the maximum inducibility and the REPs estimated for L. fuliginosus were within the same range as those reported for mammals and the more sensitive bird species but were greater than the values reported for most fish species. In conclusion, induction of EROD activity in primary hepatocytes appears to be a useful approach for evaluating the dioxin-like potencies of aryl hydrocarbon,receptor agonists in snakes. The test system offers a method for rapid screening of reptilian responsiveness to these compounds using smaller numbers of organisms than with in vivo studies, an important consideration for many declining reptile species. [source] Indices for bioavailability and biotransformation potential of contaminants in soilsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2004Washington J. Braida Abstract Bioavailability is an important consideration in risk assessment of soil contaminants and in the selection of appropriate remediation technologies for polluted sites. The present study examined the bioavailability and biodegradation potential of phenanthrene with respect to a pseudomonad in 15 different soils through separate measurements of mineralization, transformation, and desorption to a polymeric infinite sink (Tenax®) after 180-d sterile pre-equilibration with phenanthrene. Fractions strongly resistant to desorption and mineralization at long times were evident in all cases. After correcting for bioconversion (moles mineralized per mole transformed) determined in aqueous particle-free soil extracts, a correlation was found between the biotransformation-resistant fraction and the Tenax desorption-resistant fraction. Indices are proposed to assess bioavailability (BAt) and biotransformation potential (BTPt) of a compound in a soil based on parallel desorption and degradation studies over a selected period t. The BAt is the ratio of moles biotransformed to moles desorbed to an infinite sink, and it reflects the biotransformation rate relative to the maximal desorption rate. Values of BA30 (30-d values) ranged from 0.64 (for dark gray silt loam) to 1.12 (Wurtsmith Air Force Base [AFB] 2B, Oscoda, MI, USA). The BTPt is the ratio between moles biotransformed and moles of contaminant remaining sorbed after maximal desorption. The BTPt provides an indication of the maximum extent of biotransformation that may be expected in a system, assuming desorption is a prerequisite for biodegradation. Values of BTP30 ranged between 0.3 (Wurtsmith AFB 1B) and 13 (Mount Pleasant silt loam, NY, USA). The combination of BAt and BTPt provides insights regarding the relationship between physical availability (desorption) and biological processes (biotransformation kinetics, toxicity, other soil factors) that occur during biodegradation and are suggested to represent the remediation potential of the chemical. The BA30 values less than 0.9 and BTP30 values less than five indicate poor potential for site remediation. [source] Variance estimation for spatially balanced samples of environmental resourcesENVIRONMETRICS, Issue 6 2003Don L. Stevens Jr Abstract The spatial distribution of a natural resource is an important consideration in designing an efficient survey or monitoring program for the resource. We review a unified strategy for designing probability samples of discrete, finite resource populations, such as lakes within some geographical region; linear populations, such as a stream network in a drainage basin, and continuous, two-dimensional populations, such as forests. The strategy can be viewed as a generalization of spatial stratification. In this article, we develop a local neighborhood variance estimator based on that perspective, and examine its behavior via simulation. The simulations indicate that the local neighborhood estimator is unbiased and stable. The Horvitz,Thompson variance estimator based on assuming independent random sampling (IRS) may be two times the magnitude of the local neighborhood estimate. An example using data from a generalized random-tessellation stratified design on the Oahe Reservoir resulted in local variance estimates being 22 to 58 percent smaller than Horvitz,Thompson IRS variance estimates. Variables with stronger spatial patterns had greater reductions in variance, as expected. Copyright © 2003 John Wiley & Sons, Ltd. [source] The creation of an international audit and database of equine colic surgery: Survey of attitudes of surgeonsEQUINE VETERINARY JOURNAL, Issue 4 2008T. S. MAIR Summary Reasons for performing study: Currently, there is a lack of available evidence-based data concerning the optimum treatments for horses affected by different types of colic and this precludes the application of clinical audit in this area. In order to accumulate such data, a large-scale, multicentre database of the outcomes of colic surgery is proposed. The attitudes of surgeons is an important consideration in determining the feasibility of developing this database. Objectives: To assess attitudes and opinions of equine surgeons concerning clinical audit and to assess the perceived advantages and problems of setting up a large-scale international audit/database of colic surgery. Methods: Interviews were conducted with 30 equine surgeons (large animal/equine surgeons who are diplomates of either the American College of Veterinary Surgeons or the European College of Veterinary Surgeons). Questionnaires were sent by e-mail to 98 equine surgeons. Results: Face to face interviews were conducted (n = 30) and 43/98 completed questionnaires received (44%). The results of the 2 techniques were very similar. There was generally a high level of interest in the development of a large scale database of colic surgery, but perceived problems included time to collect and submit data, and confidentiality issues. A minority of surgeons reported that they were undertaking any form of specific monitoring of the results of colic surgery within their hospitals. Conclusions: There is a good level of interest among equine surgeons to develop a large scale database of colic surgery and most would be willing to contribute data from their own hospitals provided that data collection is quick and easy, and that confidentiality is maintained. Potential relevance: A large scale audit and database would provide relevant information to equine surgeons concerning the current success and complication rates of colic surgery. Such evidence-based data could be used in clinical audits within individual equine hospitals. The data would also be useful to identify trends within the discipline and could highlight areas that would benefit from active research. [source] Living with anorexia nervosa: the experience of a cohort of sufferers from anorexia nervosa 7.5 years after initial presentation to a specialized eating disorders serviceEUROPEAN EATING DISORDERS REVIEW, Issue 2 2001Eric J. Button Abstract Objective The main aim of the present study was to further understand how sufferers from anorexia nervosa view the disorder, how it affects their lives and how they experience treatment and help. Method A cohort of anorectic patients were followed up 7.5 years after presentation at a specialist locally-based eating disorders service for adults. All subjects were invited to take part in a semi-structured interview and complete a series of questionnaires. Results Thirty-six subjects were interviewed and the group as a whole showed marked improvement compared with initial presentation, but only 14 per cent were judged to be free of the disorder and about one-quarter remained entrenched in the world of anorexia nervosa. The main results focus on common themes which emerged from the interview and extensive quotes from subjects are used for illustrative purposes. Although each person expressed a very individual experience of the disorder, a common theme was of it emerging as a response to a sense of loss of control in one or more areas of their lives, often centering on their self-image and problems in relationships with others. Although the disorder was commonly experienced as having a devastating effect on their lives, the focus on weight and eating at least offered them some semblance of control. A wide range of experiences of treatment were reported, but there was considerable consensus regarding the importance of individual psychotherapy/counselling and of the quality of relationship with a therapist. Discussion This study confirms the often long-term psychological problems experienced by sufferers from anorexia nervosa and helps to illuminate the client's perspective on the disorder and other people's attempts to help. The individual views of the sufferer are an important consideration for those involved in the planning and delivery of services for these vulnerable people. Copyright © 2001 John Wiley & Sons, Ltd and Eating Disorders Association. [source] Interface Reactions in Ultrathin Functional Dielectric Films,ADVANCED ENGINEERING MATERIALS, Issue 4 2009Dieter Schmeißer The functional properties of shrunken materials should not be influenced by the reduction of the dimensions. Here, an important consideration is the control of interfacial reactions. We report on synchrotron-based spectroscopic analysis of interfaces of ultrathin functional materials (thickness <10 nm). Examples of high- k oxides, as well as of a ferroelectric polymer, are shown. We demonstrate that our spectroscopic findings are also reflected in the electric properties of thin-film devices. [source] An integrated biogeochemical and economic analysis of bioenergy crops in the Midwestern United StatesGCB BIOENERGY, Issue 5 2010ATUL K. JAIN Abstract This study integrates a biophysical model with a county-specific economic analysis of breakeven prices of bioenergy crop production to assess the biophysical and economic potential of biofuel production in the Midwestern United States. The bioenergy crops considered in this study include a genotype of Miscanthus, Miscanthus×giganteus, and the Cave-in-Rock breed of switchgrass (Panicum virgatum). The estimated average peak biomass yield for miscanthus in the Midwestern states ranges between 7 and 48 metric tons dry matter per hectare per year ( t DM ha,1 yr,1), while that for switchgrass is between 10 and 16 t DM ha,1 yr,1. With the exception of Minnesota and Wisconsin, where miscanthus yields are likely to be low due to cold soil temperatures, the yield of miscanthus is on average more than two times higher than yield of switchgrass. We find that the breakeven price, which includes the cost of producing the crop and the opportunity cost of land, of producing miscanthus ranges from $53 t,1 DM in Missouri to $153 t,1 DM in Minnesota in the low-cost scenario. Corresponding costs for switchgrass are $88 t,1 DM in Missouri to $144 t,1 DM in Minnesota. In the high-cost scenario, the lowest cost for miscanthus is $85 t,1 DM and for switchgrass is $118 t,1 DM, both in Missouri. These two scenarios differ in their assumptions about ease of establishing the perennial crops, nutrient requirements and harvesting costs and losses. The differences in the breakeven prices across states and across crops are mainly driven by bioenergy and row crop yields per hectare. Our results suggest that while high yields per unit of land of bioenergy crops are critical for the competitiveness of bioenergy feedstocks, the yields of the row crops they seek to displace are also an important consideration. Even high yielding crops, such as miscanthus, are likely to be economically attractive only in some locations in the Midwest given the high yields of corn and soybean in the region. [source] Molecular investigations into a globally important carbon pool: permafrost-protected carbon in Alaskan soilsGLOBAL CHANGE BIOLOGY, Issue 9 2010M. P. WALDROP Abstract The fate of carbon (C) contained within permafrost in boreal forest environments is an important consideration for the current and future carbon cycle as soils warm in northern latitudes. Currently, little is known about the microbiology or chemistry of permafrost soils that may affect its decomposition once soils thaw. We tested the hypothesis that low microbial abundances and activities in permafrost soils limit decomposition rates compared with active layer soils. We examined active layer and permafrost soils near Fairbanks, AK, the Yukon River, and the Arctic Circle. Soils were incubated in the lab under aerobic and anaerobic conditions. Gas fluxes at ,5 and 5 °C were measured to calculate temperature response quotients (Q10). The Q10 was lower in permafrost soils (average 2.7) compared with active layer soils (average 7.5). Soil nutrients, leachable dissolved organic C (DOC) quality and quantity, and nuclear magnetic resonance spectroscopy of the soils revealed that the organic matter within permafrost soils is as labile, or even more so, than surface soils. Microbial abundances (fungi, bacteria, and subgroups: methanogens and Basidiomycetes) and exoenzyme activities involved in decomposition were lower in permafrost soils compared with active layer soils, which, together with the chemical data, supports the reduced Q10 values. CH4 fluxes were correlated with methanogen abundance and the highest CH4 production came from active layer soils. These results suggest that permafrost soils have high inherent decomposability, but low microbial abundances and activities reduce the temperature sensitivity of C fluxes. Despite these inherent limitations, however, respiration per unit soil C was higher in permafrost soils compared with active layer soils, suggesting that decomposition and heterotrophic respiration may contribute to a positive feedback to warming of this eco region. [source] Defining targets in myeloproliferative disorders: reflecting on what is important,HEMATOLOGICAL ONCOLOGY, Issue S1 2009Martin Griesshammer Abstract The current lack of curative options for essential thrombocythaemia (ET) leads to the goal of reducing the risk of potentially life-threatening thrombohaemorrhagic complications with long-term treatment. The setting of relevant treatment targets is an important consideration in this process, allowing the monitoring of disease control. Recent revisions to the World Health Organization (WHO) diagnostic criteria for the chronic MPDs 1 have implications not only for the diagnosis of patients, but also for the management of their disease and the continuing assessment of their progress. The purpose of this article is to discuss recent revisions to the WHO guidelines, and their influence on the setting of treatment targets in patients with ET. Copyright © 2009 John Wiley & Sons, Ltd. [source] Patient preferences for in-center intense hemodialysisHEMODIALYSIS INTERNATIONAL, Issue 3 2005Nirupama Ramkumar Abstract There is a lack of data on patient preferences for intense hemodialysis (IHD). In this study, we conducted a cross-sectional survey to identify patient preferences and patient-centered barriers for IHD. A questionnaire on preferences and anticipated barriers, anticipated benefits, and quality of life for three in-center IHD schedules (daytime 2 hr six times/week [DHD], nocturnal 8 hr three times/week [ND3], and nocturnal 8 hr six times/week [ND6]) was administered to 100 chronic hemodialysis patients. A majority of patients (68%) were willing to undergo DHD for symptomatic benefits or increase in survival. An increase in energy level (94%) and improvement in sleep (57%) were the most common potential benefits that would justify DHD, but only 19% would undergo DHD for an increase in survival of ,3 years. Only 20% and 7% would consider ND3 and ND6, respectively. The most common reported barriers were inadequate time for self (50%) and family (53%), followed by transportation difficulties (53%). Most patients would undergo DHD for symptomatic or survival benefits, but not ND3 or ND6. Disruption of personal time, however, is an important consideration. Success of DHD program would depend on arrangements for transportation to dialysis unit. [source] Relationship of health-related quality of life to treatment adherence and sustained response in chronic hepatitis C patientsHEPATOLOGY, Issue 3 2002David Bernstein Interferon therapy may exacerbate health-related quality of life (HRQL) deficits associated with hepatitis C virus (HCV) early in the course of therapy. Treatment with polyethylene glycol,modified interferon (peginterferon) alfa-2a (40 kd) provides improved sustained response over interferon alfa-2a, but its effect on HRQL is unknown. The objective of this study was to (1) evaluate the effect of sustained virologic response on HRQL in patients with HCV and (2) determine whether impairment of HRQL during treatment contributes to early treatment discontinuation. Data consisted of a pooled secondary analysis of patients (n = 1,441) across 3 international, multicenter, open-label, randomized studies that compared peginterferon alfa-2a (40 kd) with interferon alfa-2a. ANCOVA was used to examine the effect of sustained virologic response on HRQL. Repeated-measures mixed-models ANCOVA was used to compare Fatigue Severity Scale (FSS) and SF-36 scores during treatment by treatment group. Logistic regression analysis was used to examine the association between changes at baseline in on-treatment HRQL and early treatment discontinuation. Sustained virologic response was associated with marked improvements from baseline to end of follow-up in all subjects, including patients with cirrhosis. During treatment, patients receiving peginterferon alfa-2a (40 kd) had statistically significantly better scores on both the SF-36 and FSS. Baseline to 24-week changes in fatigue and SF-36 mental and physical summary scores significantly predicted treatment discontinuation. In conclusion, sustained virologic response is associated with improvements in quality of life in patients with or without advanced liver disease. This parameter may be an important consideration in maximizing treatment adherence. [source] Merit pay preferences among public sector employeesHUMAN RESOURCE MANAGEMENT JOURNAL, Issue 4 2001Michelle Brown Organisations have choices about methods of pay, and employee pay adjustment preferences are an important consideration in this decision-making process. Of particular organisational interest currently are pay systems that seek to link increases with individual performance, usually referred to as merit pay. Researchers have shown that pay adjustment systems that are incompatible with employee preferences can be costly for organisations, and have identified a range of demographic factors that predict support for merit adjustments. This article extends this line of research by investigating the impact of a performance appraisal system and a range of situational factors on the level of support for merit pay in a large public sector research organisation in Australia. The study finds that higher levels of perceived job security are associated with support for merit pay, while good promotional opportunities are associated with lower levels of support. Those who saw the outcomes of the current performance appraisal system as fair were unlikely to support merit pay. [source] One- and two-dimensional modelling of overland flow in semiarid shrubland, Jornada basin, New MexicoHYDROLOGICAL PROCESSES, Issue 5 2006David A. Howes Abstract Two distributed parameter models, a one-dimensional (1D) model and a two-dimensional (2D) model, are developed to simulate overland flow in two small semiarid shrubland watersheds in the Jornada basin, southern New Mexico. The models are event-based and represent each watershed by an array of 1-m2 cells, in which the cell size is approximately equal to the average area of the shrubs. Each model uses only six parameters, for which values are obtained from field surveys and rainfall simulation experiments. In the 1D model, flow volumes through a fixed network are computed by a simple finite-difference solution to the 1D kinematic wave equation. In the 2D model, flow directions and volumes are computed by a second-order predictor,corrector finite-difference solution to the 2D kinematic wave equation, in which flow routing is implicit and may vary in response to flow conditions. The models are compared in terms of the runoff hydrograph and the spatial distribution of runoff. The simulation results suggest that both the 1D and the 2D models have much to offer as tools for the large-scale study of overland flow. Because it is based on a fixed flow network, the 1D model is better suited to the study of runoff due to individual rainfall events, whereas the 2D model may, with further development, be used to study both runoff and erosion during multiple rainfall events in which the dynamic nature of the terrain becomes an important consideration. Copyright © 2006 John Wiley & Sons, Ltd. [source] Transcoding media for bandwidth constrained mobile devicesINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 2 2005Kevin Curran Bandwidth is an important consideration when dealing with streaming media. More bandwidth is required for complex data such as video as opposed to a simple audio file. When delivering streaming media, sufficient bandwidth is required to achieve an acceptable level of performance. If the information streamed exceeds the bandwidth capacity of the client the result will be ,choppy' and incomplete with possible loss of transmission. Transcoding typically refers to the adaptation of streaming content. Typical transcoding scenarios exploit content-negotiation to negotiate between different formats in order to obtain the most optimal combination of requested quality and available resources. It is possible to transcode media to a lesser quality or size upon encountering adverse bandwidth conditions. This can be accomplished without the need to encode multiple versions of the same file at differing quality levels. This study investigates the capability of transcoding for coping with restrictions in client devices. In addition, the properties of transcoded media files are examined and evaluated to determine their applicability for streaming in relation to a range of broad device types capable of receiving streaming media.,Copyright © 2005 John Wiley & Sons, Ltd. [source] Robust and efficient quantization and coding for control of multidimensional linear systems under data rate constraintsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 10-11 2007K. Li Abstract Recently, we reported results on coding strategies for scalar feedback systems with data-rate-limited feedback channels in which the data-rate constraints are time varying. Such rate-varying channels are typically encountered in communication networks in which links between nodes are subject to noise, congestion, and intermittent disruption. The present paper describes results of extending this research into the multidimensional domain. An important consideration is that for systems of dimension greater than one, many classical feedback designs cannot be realized for operation near the theoretical minimum possible data rate. A novel control coding scheme will be presented, and in terms of this, it will be shown that the advantages of coarse signal quantization that had been reported earlier for scalar systems remain in the multidimensional case. The key is to allocate the communication bandwidth efficiently among faster and slower modes. We discuss various strategies that allocate bandwidth by scheduling the time slots assigned to each mode. In particular, we propose a ,robust attention varying' technique, whose merit will be discussed in terms of its robustness with respect to time-varying communication channel capacity and also in terms of how well it operates when the feedback channel capacity is near the theoretical minimum data rate. Copyright © 2006 John Wiley & Sons, Ltd. [source] Lower pole ratio: A new and accurate predictor of lower pole stone clearance after shockwave lithotripsy?INTERNATIONAL JOURNAL OF UROLOGY, Issue 9 2004YAN KIT FONG Abstract Background: Lower pole spatial anatomy is an important determinant of success after extracorporeal shockwave lithotripsy. In the present study, we determine whether there is a significant relationship between lower pole ratio (infundibular length : infundibular width) on preoperative intravenous urograms and stone fragment clearances after shockwave lithotripsy. Methods: A total of 42 patients with isolated lower pole stones were retrospectively reviewed. Anatomical factors, such as infundibular length, width and infundibulopelvic angle were measured and the lower pole ratio was calculated on pretreatment intravenous urogram. Stone fragment clearance was assessed at three months with a plain abdominal X-ray. Results: The overall three-month stone-free rate was 62%. Mean stone size ± SD was 10 ± 4.8 mm, mean infundibular length was 21.7 ± 6.9 mm, mean infundibular width was 6.1 ± 2.3 mm, mean infundibulopelvic angle was 62.1 ± 30.1 degrees and mean lower pole ratio was 4.3 ± 2.8. Stone-free status after shockwave lithotripsy was significantly related to infundibular length and width as well as to lower pole ratio, but not to infundibulo-pelvic angle. Infundibular length less than 30 mm, width greater than 5 mm and lower pole ratio less than 3.5 were noted to have an improved three-month stone-free rate (P = 0.049, 0.01 and <0.01, respectively). Conclusion: Caliceal anatomy is an important consideration for lower pole stone clearance after shockwave lithotripsy. The present study suggests that a lower pole ratio of less than 3.5, which considers both infundibular length and width, is a promising predictor for stone-free status. [source] Assessing impacts of large herbivores on shrubs: tests of scaling factors for utilization rates from shoot-level measurementsJOURNAL OF APPLIED ECOLOGY, Issue 1 2007DANIELLE M. BILYEU Summary 1Accurate methods for estimating the intensity of browsing by herbivores are fundamental to understanding the ecology of shrub communities. Quantifying browse utilization on shrubs at large scales is difficult because shrubs have complex, spatially variable growth forms. Most existing methods estimate browsing rate at the scale of linear current-year shoots or twigs. How such fine-scale estimates relate to the proportion of current-year growth consumed from whole plants or plots is often unknown. The relationship is likely to be complex because herbivores selectively browse more productive plants and plant parts. 2Using a clipping experiment designed to mimic elk Cervus elaphus browsing, we quantified how utilization estimates at the scale of individual current-year shoots of two willow species, Salix bebbiana and Salix geyeriana, relate to actual mass removed at the scale of rooted stems. Three approaches to scaling were examined: (i) taking an average, (ii) multiplying by the proportion of shoots clipped and (iii) multiplying by a novel scaling factor that weights utilization by productivity. To address how to scale-up from stems to plots, we applied the most accurate stem-level method to elk-browsed willow and compared plot-level estimates by two scaling approaches. 3In scaling from shoots to stems, the novel scaling factor was most successful and resulted in accurate estimates for up to c. 45% of current annual growth clipped. In scaling from the stem to the plot, elk preference for more productive stems caused a simple average of stem-level utilization to differ from a productivity-weighted average by 15%. 4Synthesis and applications. In order to reflect accurately the proportion of biomass consumed at a whole-plant level, fine-scale estimates of utilization should be weighted by an estimate of pre-browse productivity, as this is mathematically equivalent to summing pre-browse and post-browse mass before calculating the proportion consumed. In developing methods to estimate utilization at plot scales, an important consideration is the choice of sampling unit, which should be both amenable to unbiased sampling and tractable in terms of measuring productivity. [source] The feasibility of developing a risk assessment for the impact of climate change on the emergence of Crimean-Congo haemorrhagic fever in livestock in Europe: a ReviewJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2010P. Gale Summary Crimean-Congo haemorrhagic fever virus (CCHFV) is one of the most widespread of all medically important arboviruses with ticks of the Hyalomma spp. serving as the main vectors. Infection of livestock by CCHFV serves as a route of exposure to humans, as a reservoir of disease and as a route of importation. This study discusses the pathways and data requirements for a qualitative risk assessment for the emergence of CCHFV in livestock in Europe. A risk map approach is proposed based on layers that include the potential routes of release (e.g. by migrating birds carrying infected ticks) together with the main components for exposure, namely the distributions of the tick vectors, the small vertebrate host reservoirs and the livestock. A layer on landscape fragmentation serves as a surrogate for proximity of livestock to the tick cycle. Although the impact of climate change on the emergence of CCHF is not clear, comparing the distribution of risk factors in each layer currently with those predicted in the 2080s with climate change can be used to speculate how potential high-risk areas may shift. According to the risk pathway, transstadial and/or transovarial transmission in the tick vector are crucial for CCHFV spread. Vector competence and tick vector switching, however, remain critical factors for CCHFV colonization of new regions in Europe. The species of migratory bird is also an important consideration in the release assessment with greater abundance and biodiversity of ground-dwelling birds in southern Europe than in northern Europe. [source] Turnover in flightless invertebrate species composition over different spatial scales in Afrotemperate forest in the Drakensberg, South AfricaAFRICAN JOURNAL OF ECOLOGY, Issue 3 2009Charmaine Uys Abstract An understanding of species turnover at different spatial scales and the influence of environmental variables including distance are important for conservation planning and management. Ground dwelling, flightless invertebrates have poor dispersal abilities and other taxa may not be effective as surrogates. This is an important consideration for biodiversity conservation in Afrotemperate forests of the Drakensberg Mountains, South Africa, where flightless invertebrates are geographically isolated by the naturally fragmented state of forests. Seventeen Afrotemperate forests in four reserves across the Drakensberg were sampled using soil and leaf litter sampling, pitfall traps, active search quadrats and tree beats. Seventy-two species were recorded, comprising 31 mollusc, nine earthworm, one onychophoran, six centipede, twelve millipede and thirteen ant species. Canonical correspondence analysis indicated that latitude (distance); fire history (disturbance) and mean annual precipitation were the most important factors governing invertebrate assemblage composition. ,sim measurements detected change in species at all spatial scales investigated, but no clear trends were evident. Distance or spatial scale alone does not explain species turnover and community composition. Effective selection of target areas, therefore, requires species level information to identify species of special concern. Résumé Une bonne compréhension de la rotation des espèces à différentes échelles spatiales et de l'influence des variables environnementales, y compris de la distance, est importante pour la planification et la gestion de la conservation. Les invertébrés qui vivent dans le sol, ceux qui ne volent pas, n'ont que de faibles capacités de se disperser, et d'autres taxons peuvent ne pas être des substituts efficaces. Ceci pourrait être une réflexion importante pour la conservation de la biodiversité dans les forêts afro-tempérées des monts Drakensberg, en Afrique du Sud, où des invertébrés qui ne volent pas sont isolés géographiquement par l'état naturellement fragmenté des forêts. On a prélevé des échantillons dans 17 forêts afro-tempérées, dans quatre réserves du Drakensberg, en utilisant des échantillons de sols et de litière de feuilles, des pièges, la recherche active dans des quadrats et le battage d'arbres. On a enregistré 72 espèces comprenant 31 mollusques, neuf vers de terre, un onychophore, six centipèdes, 12 mille-pattes et 13 fourmis. L'analyse canonique des correspondances a indiqué que la latitude (distance), l'historique des feux (perturbations) et les précipitations annuelles moyennes étaient les facteurs les plus importants pour la composition des assemblages d'invertébrés. Des mesures de ,sim ont détecté des changements d'espèces dans toutes les échelles spatiales étudiées, mais aucune tendance nette n'était visible. L'échelle de distance ou d'espace n'explique pas seule la rotation des espèces et la composition de la communauté. La sélection effective de zones cibles requiert donc des informations au niveau des espèces pour pouvoir identifier les espèces dont le statut est particulièrement inquiétant. [source] Promoting the health of people with chronic obstructive pulmonary disease: patients' and carers' viewsJOURNAL OF CLINICAL NURSING, Issue 3-4 2010Ann Caress Aims and objectives., The aim of this study was to generate in-depth insights into patients' and family members' understanding of the causation, progression and prevention of chronic obstructive pulmonary disease and the role of health promotion with this population. In particular, we were interested in identifying the ways patients and family members considered that they could maximise their (patients') health, in the presence of this disease. Background., Chronic obstructive pulmonary disease is highly prevalent and a significant cause of morbidity and mortality, impacting on quality of life and healthcare expenditure. Health promotion is, therefore, an important consideration. There are few examples in the literature of health promotion programmes for this population, including those directed at smoking cessation, which also focus on the family or significant others. Design., An exploratory, descriptive design was employed. Method., Semi-structured, audio-recorded interviews were conducted with 14 patients and 12 family caregivers. Interviews were transcribed verbatim and thematically analysed using content analysis procedures which captured the meaning of the data. Results., The three main themes were ,health promotion: what's that?', ,community resources for health promotion' and ,it wasn't just the smoking'. Many participants seemed unaware that their health might benefit from a healthier life style and provided little spontaneous information on any activities they carried out to maintain or improve their health. Conclusions., This study highlighted a dearth of health promoting activity amongst people affected by chronic obstructive pulmonary disease. The reality for most patients was to manage the day-to-day demands that the symptoms of the disease imposed on them. Our data suggest that a more wide-ranging approach, encompassing aspects of health promotion, might be welcomed by many patients and their family carers. Relevance to clinical practice., The findings from this study highlight gaps in patients' and carers' understanding of the potential role of health promotion in chronic obstructive pulmonary disease and areas for intervention by health professionals. With the increase in smoking rates of women and predicted future increases in chronic obstructive pulmonary disease, it is imperative that health professionals find effective ways to provide support and health promotive care for patients and families. [source] REAL OPTIONS AND PATENT DAMAGES: THE LEGAL TREATMENT OF NON-INFRINGING ALTERNATIVES, AND INCENTIVES TO INNOVATEJOURNAL OF ECONOMIC SURVEYS, Issue 4 2006Jerry Hausman Abstract Patent litigation has become an increasingly important consideration in business strategy. Damage awards in patent litigation are supposed to compensate the patent owner for economic harm created by infringement and are therefore important for protecting returns to innovation. We analyze the effects that a recent court decision in the United States, called Grain Processing, has had on the incentives of potential infringers to infringe and innovators to innovate. We find that Grain Processing has decreased the expected value of damages awards in patent cases by conferring a ,free option' on infringers. Grain Processing also concluded that the patent owner in the case did not suffer lost profits due to the infringement because the infringer would have adopted an (inferior) non-infringing technology had it not infringed. We demonstrate that this conclusion is inconsistent with standard economic models. [source] A SIBTEST Approach to Testing DIF Hypotheses Using Experimentally Designed Test ItemsJOURNAL OF EDUCATIONAL MEASUREMENT, Issue 4 2000Daniel M. Bolt This paper considers a modification of the DIF procedure SIBTEST for investigating the causes of differential item functioning (DIF). One way in which factors believed to be responsible for DIF can be investigated is by systematically manipulating them across multiple versions of an item using a randomized DIF study (Schmitt, Holland, & Dorans, 1993). In this paper: it is shown that the additivity of the index used for testing DIF in SIBTEST motivates a new extension of the method for statistically testing the effects of DIF factors. Because an important consideration is whether or not a studied DIF factor is consistent in its effects across items, a methodology for testing item x factor interactions is also presented. Using data from the mathematical sections of the Scholastic Assessment Test (SAT), the effects of two potential DIF factors,item format (multiple-choice versus open-ended) and problem type (abstract versus concrete),are investigated for gender Results suggest a small but statistically significant and consistent effect of item format (favoring males for multiple-choice items) across items, and a larger but less consistent effect due to problem type. [source] | ||||||||||||||||||||||||||||||||||||||||||||||