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Selected AbstractsThe Ecological Future of the North American Bison: Conceiving Long-Term, Large-Scale Conservation of WildlifeCONSERVATION BIOLOGY, Issue 2 2008ERIC W. SANDERSON Bison bison; conservación de especies; Declaración de Vermejo; metas de conservación; representación ecológica Abstract:,Many wide-ranging mammal species have experienced significant declines over the last 200 years; restoring these species will require long-term, large-scale recovery efforts. We highlight 5 attributes of a recent range-wide vision-setting exercise for ecological recovery of the North American bison (Bison bison) that are broadly applicable to other species and restoration targets. The result of the exercise, the "Vermejo Statement" on bison restoration, is explicitly (1) large scale, (2) long term, (3) inclusive, (4) fulfilling of different values, and (5) ambitious. It reads, in part, "Over the next century, the ecological recovery of the North American bison will occur when multiple large herds move freely across extensive landscapes within all major habitats of their historic range, interacting in ecologically significant ways with the fullest possible set of other native species, and inspiring, sustaining and connecting human cultures." We refined the vision into a scorecard that illustrates how individual bison herds can contribute to the vision. We also developed a set of maps and analyzed the current and potential future distributions of bison on the basis of expert assessment. Although more than 500,000 bison exist in North America today, we estimated they occupy <1% of their historical range and in no place express the full range of ecological and social values of previous times. By formulating an inclusive, affirmative, and specific vision through consultation with a wide range of stakeholders, we hope to provide a foundation for conservation of bison, and other wide-ranging species, over the next 100 years. Resumen:,Muchas especies de mamíferos de distribución amplia han experimentado declinaciones significativas durante los últimos 200 años; la restauración de estas especies requerirá esfuerzos de recuperación a largo plazo y a gran escala. Resaltamos 5 atributos de un reciente ejercicio de gran visión para la recuperación ecológica del bisonte de Norte América (Bison bison) que son aplicables en lo general a otras especies y objetivos de restauración. El resultado del ejercicio, la "Declaración de Vermejo", explícitamente es (1) de gran escala, (2) de largo plazo, (3) incluyente, (4) satisfactor de valores diferentes y (5) ambicioso. En parte, establece que "En el próximo siglo, la recuperación ecológica del Bisonte de Norte América ocurrirá cuando múltiples manadas se desplacen libremente en los extensos paisajes de todos los hábitats importantes en su rango de distribución histórica, interactúen de manera significativa ecológicamente con el conjunto más completo de otras especies nativas e inspiren, sostengan y conecten culturas humanas." Refinamos esta visión en una tarjeta de puntuación que ilustra cómo las manadas de bisonte individuales pueden contribuir a la visión. También desarrollamos un conjunto de mapas y analizamos las distribuciones actuales y potencialmente futuras del bisonte con base en la evaluación de expertos. Aunque actualmente existen más de 500,000 bisontes en Norte América, estimamos que ocupan <1% de su distribución histórica y no expresan el rango completo de valores ecológicos y culturales de otros tiempos. Mediante la formulación de una visión incluyente, afirmativa y específica basada en la consulta a una amplia gama de interesados, esperamos proporcionar un fundamento para la conservación del bisonte, y otras especies de distribución amplia, para los próximos 100 años. [source] Kinesin-5 is not essential for mitotic spindle elongation in DictyosteliumCYTOSKELETON, Issue 11 2008Irina Tikhonenko Abstract The proper assembly and operation of the mitotic spindle is essential to ensure the accurate segregation of chromosomes and to position the cytokinetic furrow during cell division in eukaryotes. Not only are dynamic microtubules required but also the concerted actions of multiple motor proteins are necessary to effect spindle pole separation, chromosome alignment, chromatid segregation, and spindle elongation. Although a number of motor proteins are known to play a role in mitosis, there remains a limited understanding of their full range of functions and the details by which they interact with other spindle components. The kinesin-5 (BimC/Eg5) family of motors is largely considered essential to drive spindle pole separation during the initial and latter stages of mitosis. We have deleted the gene encoding the kinesin-5 member in Dictyostelium, (kif13), and find that, in sharp contrast with results found in vertebrate, fly, and yeast organisms, kif13, cells continue to grow at rates indistinguishable from wild type. Phenotype analysis reveals a slight increase in spindle elongation rates in the absence of Kif13. More importantly, there is a dramatic, premature separation of spindle halves in kif13, cells, suggesting a novel role of this motor in maintaining spindle integrity at the terminal stages of division. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source] Cell adhesion in zebrafish myogenesis: Distribution of intermediate filaments, microfilaments, intracellular adhesion structures and extracellular matrixCYTOSKELETON, Issue 10 2008Manoel L. Costa Abstract To overcome the limitations of in vitro studies, we have been studying myogenesis in situ in zebrafish embryos, at a sub-cellular level. While in previous works we focused on myofibrillogenesis and some aspects of adhesion structures, here we describe in more detail cell adhesion structures and interactions among cytoskeletal components, membrane and extracellular matrix during zebrafish muscle development. We studied the intermediate filaments, and we describe the full range of desmin distribution in zebrafish development, from perinuclear to striated, until its deposition around the intersomite septa of older somites. This adhesion structure, positive for desmin and actin, has not been previously observed in myogenesis in vitro. We also show that actin is initially located in the intersomite septum region whereas it is confined to the myofibrils later on. While actin localization changes during development, the adhesion complex proteins vinculin, paxillin, talin, dystrophin, laminin and fibronectin always appear exclusively at the intersomite septa, and appear to be co-distributed, even though the extracellular proteins accumulates before the intracellular ones. Contrary to the adhesion proteins, that are continuously distributed, desmin and sarcomeric actin form triangular aggregates among the septa and the cytoskeleton. We studied the cytoskeletal linker plectin as well, and we show that it has a distribution similar to desmin and not to actin. We conclude that the in situ adhesion structures differ from their in vitro counterparts, and that the actual zebrafish embryo myogenesis is quite different than that which occurs in in vitro systems. Cell Motil. Cytoskeleton 65: 801,815, 2008. © 2008 Wiley-Liss, Inc. [source] Inflammatory events as detected in cervical smears and squamous intraepithelial lesionsDIAGNOSTIC CYTOPATHOLOGY, Issue 2 2010Anne M. E. Roeters M.D. Abstract The Dutch cytological coding system, KOPAC, enables to code for eight inflammatory events, that is koilocytosis (related to human papillomavirus (HPV)), Trichomonas, dysbacteriosis [related to bacterial vaginosis (BV)], Candida, Gardnerella, Actinomyces, Chlamydia, and non-specific inflammation (leucocytosis). This study presents an analysis of 1,008,879 smears. Of each smear, the age of the woman and the reason for smear taking (screening or indication) was available. The cytoscores (per mille) for these codes were calculated. For the screening smears, the cytoscores were for koilocytosis (HPV) 2.6, for Trichomonas vaginalis 1.9, for dysbacteriosis 31.4, for Candida albicans 9.8, for Gardnerella vaginalis 0.7, for Actinomyces 6.9, for Chlamydia 0.8, and for non-specific inflammatory changes 66.4. For the calculation of the Odds Ratio (OR), normal smears were used as a reference. The cytoscores for Chlamydia and Gardnerella covaried with high grade SIL (HSIL), with an OR of 7 and 12, respectively. In addition, the OR for Trichomonas vaginalis, for dysbacteriosis, and for leucocytosis proved to be significantly high in the indication smears. This study provides an oversight of HSIL and the full range of cervical infections as detected by cytology, proving that this infectious byproduct of screening can be very valuable. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source] The European Service Mapping Schedule (ESMS): development of an instrumentfor the description and classificationof mental health servicesACTA PSYCHIATRICA SCANDINAVICA, Issue 2000S. Johnson Objective: This paper describes the development of an instrument for description and classification of mental health services and for measurement of service use. Purposes to be served by the instrument include: (i) identification of gaps in the spectrum of services in a catchment area; (ii) obtaining background information which may be important to understanding why apparently similar interventions lead to different outcomes in different areas; (iii) investigating how introduction of a particular type of service influences use of other local services; and (iv) understanding the relationship between sociodemographic factors and service use. Method: The instrument was developed through meetings of an international expert panel and pilot stages in several European countries. Results: Use of the European Mapping Service Mapping Schedule (ESMS) appears feasible in several countries and allowed description and classification of the full range of services identified within each of the study catchment areas. Conclusion: The ESMS promises to fill a gap in the technology available for mental health services research. Further practical experiences of its use for a variety of purposes in a variety of settings are now needed to indicate how far the ESMS does successfully generate data which are useful to researchers and planners. [source] Developmental changes in factors limiting colony survival and growth of the leaf-cutter ant Atta laevigataECOGRAPHY, Issue 3 2010Ernane H. M. Vieira-Neto Many species of leaf-cutter ants (Atta and Acromyrmex) increase in abundance following natural or anthropogenic disturbances in the vegetation. However, the mechanisms responsible for such an increase are still poorly understood. We evaluated the effects of nesting site and the availability of palatable forage on survival and growth of Atta laevigata colonies at different developmental stages. Foundress queens transplanted into man-made clearings (dirt roads) had a much higher survival than those transplanted into the adjacent undisturbed savannah vegetation. Similarly, incipient colonies (,3-months old) had significantly greater survival and growth rates in dirt roads. In contrast, nesting site did not influence performance of young colonies (,15-months old). Both incipient and young colonies responded strongly and positively to experimental supplementation of palatable forage, and this effect was independent of the nesting habitat. Colonies that received extra food grew faster and had a significantly greater survival rate than control colonies. These results suggest that performance of A. laevigata is affected by the generally greater availability of suitable nesting sites and palatable vegetation in disturbed habitats. This may explain how these ants maintain high densities in these habitats, and since the relative importance of these factors changed with colony ontogeny, our findings highlight the importance of evaluating potential limiting factors throughout the full range of an organism's developmental stages. [source] Substance use and common child mental health problems: examining longitudinal associations in a British sampleADDICTION, Issue 8 2010Anna Goodman ABSTRACT Aims To examine the longitudinal associations in both directions between mental health and substance use in adolescence. Design Three-year longitudinal cohort. Setting Britain (nationally representative sample). Participants 3607 youths aged 11,16 years at baseline. Measurements Externalizing and internalizing mental health problems were measured using brief questionnaires (parent-reported Strengths and Difficulties Questionnaire) and diagnostic interviews, including clinician-rated diagnoses of mental disorder. Substance use was measured by youth self-report, and included regular smoking, frequent alcohol consumption, regular cannabis use and ever taking other illicit drugs. Findings Externalizing (specifically behavioural) problems at baseline independently predicted all forms of substance use, with a particularly strong effect on smoking. In all cases this association showed a dose,response relationship. In contrast, although internalizing problems had a strong univariable association with smoking, this disappeared after adjusting for comorbid externalizing problems. There was little or no evidence that baseline substance use predicted mental health at follow-up. Conclusions Externalizing problems predict adolescent substance use, and adjusting for comorbid externalizing problems is vital when investigating the effects of internalizing problems. A dose,response effect of externalizing problems is seen across the full range. Programmes seeking to prevent adolescent substance use by reducing externalizing problems may therefore wish to consider population-wide interventions rather than targeting individuals only at the negative extreme. [source] Male Mate Choice in the Guppy (Poecilia reticulata): Do Males Prefer Larger Females as Mates?ETHOLOGY, Issue 2 2004Emily J. E. Herdman Although females are the choosier sex in most species, male mate choice is expected to occur under certain conditions. Theoretically, males should prefer larger females as mates in species where female fecundity increases with body size. However, any fecundity-related benefits accruing to a male that has mated with a large female may be offset by an associated fitness cost of shared paternity if large females are more likely to be multiply mated than smaller females in nature. We tested the above hypothesis and assumption using the Trinidadian guppy (Poecilia reticulata) by behaviourally testing for male mate choice in the laboratory and by ascertaining (with the use of microsatellite DNA genotyping) patterns of male paternity in wild-caught females. We observed significant positive relationships between female body length and fecundity (brood size) and between body length and level of multiple paternity in the broods of females collected in the Quaré River, Trinidad. In laboratory tests, a preference for the larger of two simultaneously-presented virgin females was clearly expressed only when males were exposed to the full range of natural stimuli from the females, but not when they were limited to visual stimuli alone. However, as suggested by our multiple paternity data, males that choose to mate with large females may incur a larger potential cost of sperm competition and shared paternity compared with males that mate with smaller females on average. Our results thus suggest that male guppies originating from the Quaré River possess mating preferences for relatively large females, but that such preferences are expressed only when males can accurately assess the mating status of encountered females that differ in body size. [source] Caloric restriction for longevity: II,The systematic neglect of behavioural and psychological outcomes in animal researchEUROPEAN EATING DISORDERS REVIEW, Issue 6 2004Kelly M. Vitousek Abstract Research on caloric restriction for longevity (CRL) has generated hundreds of articles on the physiology of food deprivation, yet almost no data on consequences in other domains. The first paper in this series outlined the generally positive physical effects of CRL; the second analyses the meagre and sometimes disturbing record of research on behaviour, cognition and affect. The available evidence suggests that nutrient-dense CRL in animals,just like nutrient-poor semi-starvation in people,is associated with a number of adverse effects. Changes include abnormal food-related behaviour, heightened aggression and diminished sexual activity. Studies of learning and memory in underfed rodents yield inconsistent findings; no information is available on cognitive effects in primates. To date, the CRL field has ignored other variables that are crucial to the human case and known to be disrupted by chronic hunger, including sociability, curiosity and emotionality. Promotion of CRL for people is irresponsible in the absence of more reassuring data on the full range of expected outcomes. Eating disorder specialists should be contributing to scientific and public discussions of this increasingly prominent paradigm. Copyright © 2004 John Wiley & Sons, Ltd and Eating Disorders Association. [source] Review of the basic insulation level for 400 kV oil-filled cable systems: Switching and temporary overvoltages (TOV)EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2003S. A. Probert This paper investigates the switching impulse and temporary overvoltage (TOV) duty for 400 kV underground power cables using ATP. This work together with the work reported in [1], investigates the full range of transient overvoltages due to lightning, switching and other temporary overvoltages (TOVs) using ATP. [1] re-assesses the basic insulation level (BIL) for 400 kV oil-filled cables. The objective of this work was to check the impact of switching surges on the choice of BIL and to re-assess the switching impulse insulation level (SIL) and TOV withstand level for 400 kV cables. A comprehensive study of the transient overvoltages experienced by cables within National Grid's transmission system has been performed. This paper provides an argument, for reducing the BIL and SIL for 400 kV cables. [source] Kinetic mechanism for p38 MAP kinase ,FEBS JOURNAL, Issue 18 2005A partial rapid-equilibrium random-order ternary-complex mechanism for the phosphorylation of a protein substrate p38 Mitogen-activated protein kinase alpha (p38 MAPK,) is a member of the MAPK family. It is activated by cellular stresses and has a number of cellular substrates whose coordinated regulation mediates inflammatory responses. In addition, it is a useful anti-inflammatory drug target that has a high specificity for Ser-Pro or Thr-Pro motifs in proteins and contains a number of transcription factors as well as protein kinases in its catalog of known substrates. Fundamental to signal transduction research is the understanding of the kinetic mechanisms of protein kinases and other protein modifying enzymes. To achieve this end, because peptides often make only a subset of the full range of interactions made by proteins, protein substrates must be utilized to fully elucidate kinetic mechanisms. We show using an untagged highly active form of p38 MAPK,, expressed and purified from Escherichia coli[Szafranska AE, Luo X & Dalby KN (2005) Anal Biochem336, 1,10) that at pH 7.5, 10 mm Mg2+ and 27 °C p38 MAPK, phosphorylates ATF2,115 through a partial rapid-equilibrium random-order ternary-complex mechanism. This mechanism is supported by a combination of steady-state substrate and inhibition kinetics, as well as microcalorimetry and published structural studies. The steady-state kinetic experiments suggest that magnesium adenosine triphosphate (MgATP), adenylyl (,,,-methylene) diphosphonic acid (MgAMP-PCP) and magnesium adenosine diphosphate (MgADP) bind p38 MAPK, with dissociation constants of KA = 360 µm, KI = 240 µm, and KI > 2000 µm, respectively. Calorimetry experiments suggest that MgAMP-PCP and MgADP bind the p38 MAPK,,ATF2,115 binary complex slightly more tightly than they do the free enzyme, with a dissociation constant of Kd , 70 µm. Interestingly, MgAMP-PCP exhibits a mixed inhibition pattern with respect to ATF2,115, whereas MgADP exhibits an uncompetitive-like pattern. This discrepancy occurs because MgADP, unlike MgAMP-PCP, binds the free enzyme weakly. Intriguingly, no inhibition by 2 mm adenine or 2 mm MgAMP was detected, suggesting that the presence of a ,-phosphate is essential for significant binding of an ATP analog to the enzyme. Surprisingly, we found that inhibition by the well-known p38 MAPK, inhibitor SB 203580 does not follow classical linear inhibition kinetics at concentrations >,100 nm, as previously suggested, demonstrating that caution must be used when interpreting kinetic experiments using this inhibitor. [source] Policy analysis for tropical marine reserves: challenges and directionsFISH AND FISHERIES, Issue 1 2003Murray A Rudd Abstract Marine reserves are considered to be a central tool for marine ecosystem-based management in tropical inshore fisheries. The arguments supporting marine reserves are often based on both the nonmarket values of ecological amenities marine reserves provide and the pragmatic cost-saving advantages relating to reserve monitoring and enforcement. Marine reserves are, however, only one of a suite of possible policy options that might be used to achieve conservation and fisheries management objectives, and have rarely been the focus of rigorous policy analyses that consider a full range of economic costs and benefits, including the transaction costs of management. If credible analyses are not undertaken, there is a danger that current enthusiasm for marine reserves may wane as economic performance fails to meet presumed potential. Fully accounting for the value of ecological services flowing from marine reserves requires consideration of increased size and abundance of focal species within reserve boundaries, emigration of target species from reserves to adjacent fishing grounds, changes in ecological resilience, and behavioural responses of fishers to spatially explicit closures. Expanding policy assessments beyond standard cost,benefit analysis (CBA) also requires considering the impact of social capital on the costs of managing fisheries. In the short term, the amount of social capital that communities possess and the capacity of the state to support the rights of individuals and communities will affect the relative efficiency of marine reserves. Reserves may be the most efficient policy option when both community and state capacity is high, but may not be when one and/or the other is weak. In the longer term, the level of social capital that a society possesses and the level of uncertainty in ecological and social systems will also impact the appropriate level of devolution or decentralization of fisheries governance. Determining the proper balance of the state and the community in tropical fisheries governance will require broad comparative studies of marine reserves and alternative policy tools. [source] Bird densities are associated with household densitiesGLOBAL CHANGE BIOLOGY, Issue 8 2007JAMIE TRATALOS Abstract Increasing housing density is an important component of global land transformation, with major impacts on patterns of biodiversity. However, while there have been many studies of the changes in biodiversity across rural,urban gradients, which are influenced in large part by housing densities, how biodiversity changes across the full range of regional variation in housing density remains poorly understood. Here, we explore these relationships for the richness and abundance of breeding birds across Britain. Total richness, and that of 27 urban indicator species, increased from low to moderate household densities and then declined at greater household densities. The richness of all species increased initially faster with household density than did that of the urban indicator species, but nonurban indicator species richness declined consistently after peaking at a very low housing density. Avian abundance showed a rather different pattern. Total abundance and that summed across all urban indicator species increased over a wide range of household densities, and declined only at the highest household densities. The abundance of individual urban indicator species generally exhibited a hump-shaped relationship with housing density. While there was marked intraspecific variation in the form of such relationships, almost invariably avian abundance declined at housing densities below that at which the UK government requires new developments to be built. Our data highlight the difficulties of maintaining biodiversity while minimising land take for new development. High-density housing developments are associated with declines in many of those species otherwise best able to exploit urban environments, and those components of native biodiversity with which human populations are often most familiar. [source] General Steady-State Shape Factor for a Partially Penetrating WellGROUND WATER, Issue 1 2010Vitaly A. Zlotnik We present the closed form of a general steady-state shape factor for a partially penetrating well in a uniform anisotropic aquifer. Our simple analytical expression for the shape factor has a uniform representation for full range of parameters and meets or exceeds the accuracy of previous results obtained through semiempirical methods (e.g., Bouwer and Rice [1976] equations). This general shape factor pertains to the flow of fluids (water or air) in subsurface formations when the upper formation boundary has constant potential and the lower boundary is impermeable. The results of our investigation are directly applicable to analyses of (1) slug tests with falling or rising head and (2) injection/extraction tests with constant head, essential techniques for the characterization of hydraulic conductivity of aquifers, streambeds, or lakebeds as well as the design of aquifer and soil remediation systems. [source] Development and preliminary testing of a Paediatric Version of the Haemophilia Activities List (pedhal)HAEMOPHILIA, Issue 2 2010W. G. GROEN Summary., Worldwide, children with haemophilia suffer from limitations in performing activities of daily living. To measure such limitations in adults a disease-specific instrument, the Haemophilia Activities List (HAL), was created in 2004. The aim of this study was to adapt the HAL for children with haemophilia and to assess its psychometric properties. The structure and the main content were derived from the HAL. Additionally, items of the Childhood Health Assessment Questionnaire and the Activity Scale for Kids were considered for inclusion. This version was evaluated by health professionals (n = 6), patients (n = 4), and parents (n = 3). A pilot test in a sample of 32 Dutch children was performed to assess score distribution, construct validity (Spearman's rho) and reproducibility. Administration of the pedhal was feasible for children from the age of 4 years onwards. The pedhal scores of the Dutch children were in the high end of the scale, reflecting a good functional status. Most subscales showed moderate associations with the joint examination (rho = 0.42,0.63) and moderate-to-good associations with the physical function subscale of the CHQ-50 (rho = 0.48,0.74). No significant associations were found for the pedhal and the subscales mental health and behaviour, except for the subscales leisure and sport and mental health (rho = 0.47). Test,retest agreement was good. The pedhal is a promising tool, but further testing in populations with a higher level of disability is warranted to study the full range of its psychometric properties. [source] Whither trial-based economic evaluation for health care decision making?HEALTH ECONOMICS, Issue 7 2006Mark J. Sculpher Abstract The randomised controlled trial (RCT) has developed a central role in applied cost-effectiveness studies in health care as the vehicle for analysis. This paper considers the role of trial-based economic evaluation in this era of explicit decision making. It is argued that any framework for economic analysis can only be judged insofar as it can inform two key decisions and be consistent with the objectives of a health care system subject to its resource constraints. The two decisions are, firstly, whether to adopt a health technology given existing evidence and, secondly, an assessment of whether more evidence is required to support this decision in the future. It is argued that a framework of economic analysis is needed which can estimate costs and effects, based on all the available evidence, relating to the full range of possible alternative interventions and clinical strategies, over an appropriate time horizon and for specific patient groups. It must also enable the accumulated evidence to be synthesised in an explicit and transparent way in order to fully represent the decision uncertainty. These requirements suggest that, in most circumstances, the use of a single RCT as a vehicle for economic analysis will be an inadequate and partial basis for decision making. It is argued that RCT evidence, with or without economic content, should be viewed as simply one of the sources of evidence, which must be placed in a broader framework of evidence synthesis and decision analysis. Copyright © 2006 John Wiley & Sons, Ltd. [source] The integration of ecological risk assessment and structured decision making into watershed managementINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 1 2007Dan W Ohlson Abstract Watershed management processes continue to call for more science and improved decision making that take into account the full range of stakeholder perspectives. Increasingly, the core principles of ecological risk assessment (i.e., the development and use of assessment endpoints and conceptual models, conducting exposure and effects analysis) are being incorporated and adapted in innovative ways to meet the call for more science. Similarly, innovative approaches to adapting decision analysis tools and methods for incorporating stakeholder concerns in complex natural resource management decisions are being increasingly applied. Here, we present an example of the integration of ecological risk assessment with decision analysis in the development of a watershed management plan for the Greater Vancouver Water District in British Columbia, Canada. Assessment endpoints were developed, ecological inventory data were collected, and watershed models were developed to characterize the existing and future condition of 3 watersheds in terms of the potential risks to water quality. Stressors to water quality include sedimentation processes (landslides, streambank erosion) and forest disturbance (wildfire, major insect or disease outbreak). Three landscape-level risk management alternatives were developed to reflect different degrees of management intervention. Each alternative was evaluated under different scenarios and analyzed by explicitly examining value-based trade-offs among water quality, environmental, financial, and social endpoints. The objective of this paper is to demonstrate how the integration of ecological risk assessment and decision analysis approaches can support decision makers in watershed management. [source] Localized failure of fibre-reinforced elastic,plastic materials subjected to plane strain loadingINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 7 2007Dunja Peri Abstract We consider discontinuous bifurcations as the indicator of a localized failure for a class of composites that are characterized by elastic fibres reinforcing an elastic,plastic matrix. A macroscopic tangent stiffness tensor for the fibre-reinforced composite is developed by consistently homogenizing the contribution of fibres in a spherical representative volume element. Analytical solutions are derived for the critical hardening modulus and corresponding bifurcation directions for the case of plane strain loading. Properties of the solutions are further illustrated on the example of the non-associated Drucker,Prager model at onset of yielding. Results show that presence of fibres decreases the critical hardening modulus, thus inhibiting the onset of strain localization. The rate of decrease in the critical hardening modulus is the highest for pure shear, followed by uniaxial tension, uniaxial compression, biaxial tension and biaxial compression. The main fibre parameters that control the onset of strain localization are their volumetric content and their stiffness modulus whereby very stiff fibres can produce the most significant decrease in the critical hardening modulus, especially for the state of biaxial tension. The critical hardening modulus for the non-associated Drucker,Prager model exhibits a full range of localization modes including compaction bands, dilation bands, and transition in the form of shear bands regardless of the presence of fibres. Presence of fibres affects bifurcation directions, except in the case when Poisson's ratio of the matrix is equal to 0.25. The results demonstrate stabilizing effects of fibres by which they provide the control against the onset of strain localization. Copyright © 2006 John Wiley & Sons, Ltd. [source] Pilot study of latewood-width of conifers as an indicator of variability of summer rainfall in the North American monsoon regionINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 6 2001David M. Meko Abstract The variability of the North American Monsoon System (NAMS) is important to the precipitation climatology of Mexico and the southwestern United States. Tree-ring studies have been widely applied to climatic reconstruction in western North America, but as yet, have not addressed the NAMS. One reason is the need for highly resolved seasonal dendroclimatic information. Latewood-width, the portion of the annual tree ring laid down late in the growing season, can potentially yield such information. This paper describes a pilot study of the regional summer precipitation signal in latewood-width from a network of five Pseudotsuga menziesii chronologies developed in the heart of the region of NAMS influence in Arizona, USA. Exploratory data analysis reveals that the summer precipitation signal in latewood is strong, but not equally so over the full range of summer precipitation. Scatter in the relationship increases toward higher levels of precipitation. Adjustment for removal of inter-correlation with earlywood-width appears to strengthen the summer precipitation signal in latewood-width. To demonstrate a possible application to climatic reconstruction, the latewood precipitation signal is modelled using a nonlinear model,a binary recursive classification tree (CT) that attempts to classify summers as dry or not dry from threshold values of latewood-width. The model identifies narrow latewood-width as an effective predictor of a dry summer. Of 14 summers classified dry by latewood-width for the period 1868,1992, 13 are actually dry by the instrumental precipitation record. The results suggest that geographical expansion of coverage by latewood-width chronologies and further development of statistical methods may lead to successful reconstruction of variability of the NAMS on century time scales. Copyright © 2001 Royal Meteorological Society [source] Systematic review of the effectiveness of integrated care pathways: what works, for whom, in which circumstances?INTERNATIONAL JOURNAL OF EVIDENCE BASED HEALTHCARE, Issue 2 2009Davina Allen RGN BA(Hons) PhD Abstract Aim, Integrated care pathways (ICP) are management technologies which formalise multidisciplinary team-working and enable professionals to examine their roles and responsibilities. ICPs are now being implemented across international healthcare arena, but evidence to support their use is equivocal. The aim of this study was to identify the circumstances in which ICPs are effective, for whom and in what contexts. Methods, A systematic review of high-quality randomised controlled trials published between 1980 and 2008 (March) evaluating ICP use in child and adult populations in the full range of healthcare settings. Results 1For relatively predictable trajectories of care ICPs can be effective in supporting proactive care management and ensuring that patients receive relevant clinical interventions and/or assessments in a timely manner. This can lead to improvements in service quality and service efficiency without adverse consequences for patients. 2ICPs are an effective mechanism for promoting adherence to guidelines or treatment protocols thereby reducing variation in practice. 3ICPs can be effective in improving documentation of treatment goals, documentation of communication with patients, carers and health professionals. 4ICPs can be effective in improving physician agreement about treatment options. 5ICPs can be effective in supporting decision-making when they incorporate a decision-aide. 6The evidence considered in this review indicates that ICPs may be particularly effective in changing professional behaviours in the desired direction, where there is scope for improvement or where roles are new. 7Even in contexts in which health professionals are already experienced with a particular pathway, ICP use brings additional beneficial effects in directing professional practice in the desired direction. 8ICPs may be less effective in bringing about service quality and efficiency gains in variable patient trajectories. 9ICPs may be less effective in bringing about quality improvements in circumstances in which services are already based on best evidence and multidisciplinary working is well established. 10Depending on their purpose, the benefits of ICPs may be greater for certain patient subgroups than others. 11We do not know whether the costs of ICP development and implementation are justified by any of their reported benefits. 12ICPs may need supporting mechanisms to underpin their implementation and ensure their adoption in practice, particularly in circumstances in which ICP use is a significant change in organisational culture. 13ICP documentation can introduce scope for new kinds of error. Conclusions, ICPs are most effective in contexts where patient care trajectories are predictable. Their value in settings in which recovery pathways are more variable is less clear. ICPs are most effective in bringing about behavioural changes where there are identified deficiencies in services; their value in contexts where inter-professional working is well established is less certain. None of the studies reviewed included an economic evaluation and thus it is not known whether their benefits justify the costs of their implementation. [source] Recording dental caries in archaeological human remainsINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 4 2001Simon Hillson Abstract Dental caries is an important condition to record in archaeological collections, but the way in which recording is carried out has a large effect on the way in which the results can be interpreted. In living populations, dental caries is a disease that shows a strong relationship with age. Both the nature of carious lesions and their frequency change with successive age groups from childhood to elderly adulthood. There is also a progression in the particular teeth in the dentition which are most commonly affected and, in general, the molars and premolars are involved much more frequently than the canines and incisors. Lower teeth are usually affected more than upper, although the condition usually involves the right and left sides fairly equally. In the high tooth wear rate populations represented by many archaeological and museum collections, there is a complex relationship between the form of lesions and the state of wear, which adds yet another range of factors to the changing pattern of caries with increasing age. In the same populations, chipping, fracture and anomalous abrasion of teeth are also common, and these contribute similarly to the distribution and forms of carious lesion observed. Amongst the living, the pattern of ante-mortem tooth loss is important in understanding caries and, in archaeological material, there is also the complicating factor of post-mortem tooth loss. Finally, there is the question of diagnosis. There are diagnostic problems even in epidemiological studies of living patients and, for archaeological specimens, diagenetic change and the variable preservation of different parts of the dentition add further complications. For all these reasons, it is difficult to define any one general index of dental caries to represent the complete dentition of each individual, which would be universally suitable for studying a full range of collections from archaeological sites or museums. Variation in the nature of collections, their preservation, tooth wear, and ante-mortem and post-mortem tooth loss mean that when such a general index appears to differ between sites, there could be many other reasons for this, in addition to any genuine differences in caries incidence and pattern that might have been present. It is suggested here that the best approach is instead to make comparisons separately for each tooth type, age group, sex, lesion type and potential lesion site on the tooth. Copyright © 2001 John Wiley & Sons, Ltd. [source] Graduate Recruitment and Selection in AustraliaINTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 2 2007Sally A. Carless Through a national survey of graduate recruitment coordinators, this study identified current recruitment and selection practices in Australia. Respondents (n=50) were mostly from private industry with about a third from the government sector, the full range of industry sectors was represented. Respondents were asked about the management of recruitment activities, methods used to communicate recruiting information, and the perceived accuracy of recruitment information. Information was also sought about the extent that job analyses were used, type of selection practices used, how applicant information was verified, the training and selection of interviewers and the effectiveness of recruitment activities. Descriptive statistics were used to provide a summary of the findings. A regression analysis was used to examine predictors of (a) recruiting effectiveness, (b) acceptance rates, and (c) unfilled vacancies. The results were compared with other studies of recruitment and selection. Future research and practical applications were discussed. [source] Truth-Seeking, Truth-Telling, and Postconflict Peacebuilding: Curb the Enthusiasm?,INTERNATIONAL STUDIES REVIEW, Issue 3 2004David Mendeloff This essay evaluates popular and scholarly claims about the peace-promoting benefits of formal truth-telling and truth-seeking mechanisms in the aftermath of civil wars. Its purpose is twofold. First, it synthesizes and clearly articulates in one place the full range of claims about the relationship between truth-telling and peacebuilding. Second, it evaluates these claims by systematically examining the core factual and theoretical assumptions on which they are based. An argument is made that many such claims,and their core assumptions,are flawed or highly contentious as well as that truth-telling advocates claim far more about the power of truth-telling than logic or evidence dictates. This is not to say that truth-telling has no role to play in preventing the resumption of violent conflict in postwar societies, only that proponents likely overstate its importance. Before proclaiming the necessity of truth commissions or trials in the aftermath of violent conflict, we need to better understand how truth-telling prevents the recurrence of civil war, how important it is relative to other factors and other peacebuilding strategies, and when it is likely to prove helpful, harmful, or irrelevant. [source] Psychometric Properties of the Activities-Specific Balance Confidence Scale and the Survey of Activities and Fear of Falling in Older WomenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2008Kristine M.C. Talley MS OBJECTIVES: To compare the psychometric properties of the Activities-specific Balance Confidence Scale (ABC) and the Survey of Activities and Fear of Falling in the Elderly (SAFE). DESIGN: Secondary analysis using baseline and 12-week data from a randomized, controlled trial on fall prevention. SETTING: Upper Midwest metropolitan area with assessments conducted in participants' homes. PARTICIPANTS: Population-based sample of 272 noninstitutionalized female Medicare beneficiaries aged 70 and older at risk of falling. MEASUREMENTS: Participants self-administered the ABC, SAFE, Geriatric Depression Scale, and Medical Outcomes Study 36-item Short Form Survey. During a home visit, a nurse practitioner administered the Berg Balance Test and Timed Up and Go, measured gait speed, and asked about falls and chronic illnesses. RESULTS: Baseline internal consistency measured using Cronbach alpha was 0.95 for the ABC and 0.82 for the SAFE. Baseline concurrent validity between the ABC and SAFE measured using a correlation coefficient was ,0.65 (P<.001). ABC and SAFE scores were significantly correlated at baseline with physical performance tests and self-reported health status. The ABC had stronger baseline correlations than the SAFE with most measures. Neither instrument demonstrated responsiveness to change at 12 weeks. CONCLUSION: The ABC and SAFE demonstrated strong internal-consistency reliability and validity when self-administered. The ABC had stronger associations with physical functioning and may be more appropriate for studies focused on improving physical function. Both instruments demonstrated ceiling effects, which may explain the lack of responsiveness to change in relatively nonfrail older women. Instruments sensitive to measuring lower levels of fear of falling are needed to capture the full range of this phenomenon in this population. [source] Resolving the departures of observed results from the Ideal Free Distribution with simple random movementsJOURNAL OF ANIMAL ECOLOGY, Issue 4 2004A. L. Jackson Summary 1The Ideal Free Distribution (IFD) is one of the most widely applied theoretical concepts in ecology. Many experimental tests of the IFD incorporating unequal competitors have revealed three consistent departures of observed results from those predicted by the theory. Specifically these are: (1) the full range of predicted equilibria are rarely realized; (2) under-matching of individuals to resource inputs; and (3) continued movement of individuals after equilibrium is reached. 2It has been suggested previously that a model including simple random movements can explain simultaneously all three of these departures. The acceptance of this theory has been hindered by arguments about model construction relating to the timing of events and whether an analytical or individual-based model is more appropriate. 3Here we present the first internally consistent and biologically realistic model of the IFD incorporating random non-IFD movements (movements made at a rate independent of intake rates). We use this model to confirm that random movements alone can explain all three of the observed departures from the IFD. Furthermore, it is not necessary to have any detailed a priori knowledge about the motivation behind the non-IFD movements, in order to predict their consequences. We expect non-IFD movements to be widespread in animal systems, and so warrant further experimental consideration and investigation. [source] INTEGRATING RISK MANAGEMENT AND CAPITAL MANAGEMENTJOURNAL OF APPLIED CORPORATE FINANCE, Issue 4 2002Prakash Shimpi Capital management and risk management are two sides of the same coin. But by treating them separately, the conventional theory and practice of corporate finance fails to account for important connections between them. Moreover, an exclusive focus on debt and equity ignores the full range of capital resources available to a corporation, thus distorting management's view of the firm's cost of capital (and its return on equity). An understanding of the role of corporate capital,including off-balance sheet as well as paid-up capital,and its relationship to the riskiness of a firm's activities provides the foundation on which the author builds a corporate finance framework that ties together both the insurance and capital markets. This framework, called the "Insurative Model," captures the economics of both conventional insurance and corporate finance instruments and embraces a wide variety of solutions and instruments,be they debt, equity, insurance, derivative, contingent capital, or any other,and allows managers to evaluate their effectiveness in a consistent, unified way. The Insurative Model demonstrates that a company's decisions on insurance and risk retention can be just as important as its decisions about its debt-equity mix. In fact, the determination of a firm's optimal debt-equity ratio should be the last in a series of capital and risk management decisions. Earlier decisions should address risk retention, risk transfer, and the optimal amounts and structure of off-balance-sheet capital used to support the company's retained risks. [source] Scaling and Testing Multiplicative Combinations in the Expectancy,Value Model of AttitudesJOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 9 2008Icek Ajzen This article examines the multiplicative combination of belief strength by outcome evaluation in the expectancy,value model of attitudes. Because linear transformation of a belief strength measure results in a nonlinear transformation of its product with outcome evaluation, use of unipolar or bipolar scoring must be empirically justified. Also, the claim that the Belief × Evaluation product fails to explain significant variance in attitudes is found to be baseless. In regression analyses, the main effect of belief strength takes account of the outcome's valence, and the main effect of outcome evaluation incorporates the outcome's perceived likelihood. Simulated data showed that multiplication adds substantially to the prediction of attitudes only when belief and evaluation measures cover the full range of potential scores. [source] The irreversible cattle-driven transformation of a seasonally flooded Australian savannaJOURNAL OF BIOGEOGRAPHY, Issue 5 2003Ben R. Sharp Abstract Aim ,Anecdotal historical and photographic evidence suggests that woody vegetation is increasing dramatically in some northern Australian savanna habitats. Vegetation change in savannas has important implications for pastoral land-use, conservation management, and landscape-scale carbon storage, and informs theoretical debates about ecosystem function. This study seeks to determine the nature, extent and cause(s) of woody vegetation change in a seasonally flooded alluvial savanna habitat. Location ,The study area is located within the seasonally inundated alluvial zone of the tidal portion of the Victoria River, Northern Territory, Australia. The study area has been grazed by domestic stock since c. 1900, prior to which the area was inhabited and more likely regularly burnt by Aboriginal people for thousands of years. Methods ,Digital georeferenced aerial photographic coverages were used to examine and quantify woody vegetation change between 1948 and 1993. Transect surveys of woody and herbaceous vegetation were carried out to ground-truth air-photo results and determine the nature and causes of observed vegetation changes. Results ,There has been a dramatic increase in woody vegetation cover throughout the study area. Vegetation change patterns are roughly uniform across the full range of edaphic habitat variation and are unrelated to the depositional age of fluvial sediments. Two woody species, Eucalyptus microtheca and Excoecaria parvifolia, are predominantly responsible for observed increases. Demographic analyses reveal that woody invasions have been episodic and indicate that in most locations peak woody species establishment occurred in the mid-1970s. Grasses are almost absent in a majority of habitats within the study area. Instead, large areas are covered by scalded soil, dense invasive weed populations, and unpalatable forbs and sedges. What grasses do occur are predominantly of very low value for grazing. The condition of the herbaceous layer renders most of the study area almost completely non-flammable; what fires do burn are small and of low intensity. Main conclusions ,Multiple working hypotheses explaining observed patterns of woody vegetation increase were considered and rejected in turn. The only hypothesis consistent with the evidence is as follows: (1) observed changes are a direct consequence of extreme overgrazing by cattle, most likely when stocking rates peaked in the mid-1970s; (2) prolonged heavy grazing effected the complete transformation of much of the herbaceous vegetation to a new state that is not flammable; and (3) in the absence of regular fire mortality, woody vegetation increased rapidly. The relatively treeless system that existed in 1948 was apparently stable and resilient to moderate grazing levels, and perhaps also to episodic heavy grazing events. However, grazing intensity in excess of a sustainable threshold has forced a transition that is irreversible in the foreseeable future. Stable-state transitions such as this one inform debates at the heart of ecological theory, such as the nature of stability, resilience, equilibrium and carrying capacity in dynamic savanna ecosystems. [source] Menstrual age,dependent systematic error in sonographic fetal weight estimation: A mathematical modelJOURNAL OF CLINICAL ULTRASOUND, Issue 3 2002Max Mongelli MD Abstract Purpose We used computer modeling techniques to evaluate the accuracy of different types of sonographic formulas for estimating fetal weight across the full range of clinically important menstrual ages. Methods Input data for the computer modeling techniques were derived from published British standards for normal distributions of sonographic biometric growth parameters and their correlation coefficients; these standards had been derived from fetal populations whose ages were determined using sonography. The accuracy of each of 10 formulas for estimating fetal weight was calculated by comparing the weight estimates obtained with these formulas in simulated populations with the weight estimates expected from birth weight data, from 24 weeks' menstrual age to term. Preterm weights were estimated by interpolation from term birth weights using sonographic growth curves. With an ideal formula, the median weight estimates at term should not differ from the population birth weight median. Results The simulated output sonographic values closely matched those of the original population. The accuracy of the fetal weight estimation differed by menstrual age and between various formulas. Most methods tended to overestimate fetal weight at term. Shepard's formula progressively overestimated weights from about 2% at 32 weeks to more than 15% at term. The accuracy of Combs's and Shinozuka's volumetric formulas varied least by menstrual age. Hadlock's formula underestimated preterm fetal weight by up to 7% and overestimated fetal weight at term by up to 5%. Conclusions The accuracy of sonographic fetal weight estimation based on volumetric formulas is more consistent across menstrual ages than are other methods. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:139,144, 2002; DOI 10.1002/jcu.10051 [source] Diffusion, Use and Impact of the Internet in Hong Kong: A Chain Process ModelJOURNAL OF COMPUTER-MEDIATED COMMUNICATION, Issue 2 2002Jonathan J. H. Zhu Hong Kong appears to be a dream venue for the Internet as a mass medium: There are a well-developed telecommunications infrastructure, a population with both financial resources and bilingual (Chinese and English) abilities, and a legal environment in which there is virtually no government regulation of content. However, recent experience with the slow adoption of other new media in Hong Kong, including cable TV and interactive TV, has sounded a cautionary note about the potential use and impact of the Internet in this technologically sophisticated city. Based on a telephone survey of 1,000 adult residents, this paper examines the adoption, use, and social impact of the Internet in Hong Kong using a chain process model that was initially developed by Dutton, Rogers, and Jun (1987) for research on home computing. The results show that Internet adoption is affected by a full range of factors, including one's personal characteristics, socioeconomic status, socio-cultural settings, and perceived compatibility of the Internet. On the other hand, Internet use is primarily affected by socioeconomic status and perceived compatibility. The study also found that both adoption and use of the Internet have observable impact on leisure activities and concerns for privacy and other Internet-related negative consequences. However, these effects are not overarching but rather confined to specific attitudes and behavior. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||