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Management Implications (management + implication)
Selected AbstractsUncertainty about estimating total returns of Atlantic salmon, Salmo salar to the Gander River, Newfoundland, Canada, evaluated using a fish counting fenceFISHERIES MANAGEMENT & ECOLOGY, Issue 1 2003M. F. O'Connell Abstract ,For a number of rivers in Newfoundland, Atlantic salmon, Salmo salar L., is managed in relation to river-specific conservation spawning requirements. One such river is the Gander River, where between 1989 and 1999, the escapement of Atlantic salmon, a major factor in assessing the status of stock, was determined using a fish counting fence. In 2000, the counting fence was discontinued and alternative means of calculating total returns were explored. Regression and simulation methods, using relationships between total returns and salmon counts at an upstream tributary during 1989,99, formed the basis for estimates of returns for 2000, and the uncertainty around estimates. The accuracy of methods is evaluated by retrospective comparisons with actual total returns between 1989 and 1999. Estimates of total returns deviated from the actual by as much as 50,60%, depending on the method. Management implications of the approach are discussed. [source] Evaluation of soil saturation, soil chemistry, and early spring soil and air temperatures as risk factors in yellow-cedar declineGLOBAL CHANGE BIOLOGY, Issue 3 2006D. V. D'AMORE Abstract Yellow-cedar (Callitropsis nootkatensis (D. Don) Oerst.) is a valuable tree species that is experiencing a widespread decline and mortality in southeast Alaska. This study evaluated the relative importance of several potential risk factors associated with yellow-cedar decline: soil saturation, soil aluminum (Al) toxicity or calcium (Ca) deficiency, and air and soil temperature. Data were collected from permanent vegetation plots established in two low-elevation coastal forests exhibiting broad ranges of cedar mortality. Measurements of each risk factor were contrasted among classified forest zones to indicate if there were strong links with decline. Hydrology alone is weakly associated with yellow-cedar decline, but could have a predisposing role in the decline by creating exposed conditions because of reduced forest productivity. Yellow-cedar decline is not strongly associated with soil pH and extractable Al and Ca, but there appears to be Ca enrichment of surface soils by feedback from dead yellow-cedar foliage. Air and soil temperature factors are strongly associated with decline. Based on these results, an hypothesis is presented to explain the mechanism of tree injury where exposure-driven tree mortality is initiated in gaps created by soil saturation and then expands in gaps created by the tree-mortality itself. The exposure allows soils to warm in early spring causing premature dehardening in yellow-cedar trees and subsequent freezing injury during cold events. Yellow-cedars growing in the protection of shade or snow are not preconditioned by this warming, and thus not as susceptible to cold injury. Yellow-cedar decline appears to be associated with regional climate changes, but whether the cause of these changes is related to natural or human-induced climate shifts remains uncertain. Management implications, the possible role of climate, and recommended research are discussed. [source] Management implications of the Macquarie Island trophic cascade revisited: a reply to Dowding et al. (2009)JOURNAL OF APPLIED ECOLOGY, Issue 5 2009Dana M. Bergstrom Summary 1. The management of non-indigenous species is not without its complications. In Bergstrom et al.'s (2009) study, we demonstrated that feral cats Felis catus on sub-Antarctic Macquarie Island were exerting top-down control on the feral rabbit Oryctolagus cuniculus population, and that the eradication of the cats led to a substantial increase in rabbit numbers and an associated trophic cascade. 2. Dowding et al. (2009) claim our modelling was flawed for various reasons, but primarily that a reduction in the application of the rabbit control agent, Myxoma virus, coinciding with cat removal, was a major driver of rabbit population release. 3. We explore this proposition (as well as others) by examining rates of Myxoma viral release between 1991 and 2006 (with an attenuation factor for the years, 2003,2006) in association with presence/absence of cats against two estimates of rabbit population size. Myxoma viral release was a significant factor in the lower estimates of rabbit population, but the effect was small, and was not significant for higher rabbit population estimates. By contrast, the presence or absence of cats remained highly significant for both estimates. 4.Synthesis and applications. We re-affirm our position that top-down control of rabbit numbers by cats, prior to their eradication, was occurring on Macquarie Island. Nonetheless, we agree with Dowding et al. (2009) that systems with multiple invasive species represent complex situations that require careful scrutiny. Such scrutiny should occur in advance of, during, and following management interventions. [source] Effects of sunlight exposure and log size on pine engraver (Coleoptera: Curculionidae) reproduction in ponderosa pine slash in Northern Arizona, U.S.A.AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2009Christopher J. Hayes Abstract 1,Abiotic conditions within logs can affect pine engraver Ips pini (Say) reproductive success, and slash management techniques have been developed that exploit these relationships to reduce brood production. In the present study, we investigated the affect of sunlight exposure on phloem temperature and moisture in logs of two diameters and the subsequent effects on pine engraver reproduction. 2,Logs, 30 cm in length, with diameters of 10 and 15 cm, were cut, left in the field for natural colonization by I pini, and then placed in an open meadow and under shade cloth, providing 27% and 66% shade, until offspring beetles had left the logs. Phloem temperature and moisture were recorded over the duration of the experiment and, at the end of the field experiment, logs were dissected and galleries were measured to gauge beetle reproductive success. 3,As sunlight exposure increased, phloem temperatures increased and potentially lethal temperatures were often reached in the high-sunlight exposure but seldom in the low-sunlight. Smaller diameter logs had drier phloem than larger diameter logs. All logs dried with time but sunlight level did not affect desiccation rates. Ips pini preferred attacking larger logs and the bottom side of logs. Sunlight exposure had a significant effect on net reproductive success in smaller diameter logs, with very little net reproductive success in high-sunlight exposed logs, and the highest reproductive success was found in small diameter logs in the low-sunlight treatments. 4,Management implications of these results are discussed. [source] Exploring consumer knowledge structures using associative network analysisPSYCHOLOGY & MARKETING, Issue 4 2010Thorsten A. Teichert This paper offers a new perspective on consumer knowledge analysis that combines Human Associative Memory (HAM) models from cognitive psychology with network analytic approaches in order to gain deeper insights into consumers" mental representations, such as brand images. An illustrative case study compares the associative networks of a manufacturer brand with a retail brand and is used to demonstrate the application and interpretation of various network measures. Network analysis is conducted on three levels: Node-level analysis yields insights about salient brand image components that can be affected through short-term marketing activities. Group-level analysis is concerned with brand image dimensions that characterize a brand and can be strategically influenced in the medium term. Finally, network-level analysis examines the network structure as a whole, drawing parallels to brand imagery, which needs to be managed over the long term. Management implications are derived and suggestions for further research are provided. © 2010 Wiley Periodicals, Inc. [source] Using Logistic Regression to Analyze the Sensitivity of PVA Models: a Comparison of Methods Based on African Wild Dog ModelsCONSERVATION BIOLOGY, Issue 5 2001Paul C. Cross Standardized coefficients from the logistic regression analyses indicated that pup survival explained the most variability in the probability of extinction, regardless of whether or not the model incorporated density dependence. Adult survival and the standard deviation of pup survival were the next most important parameters in density-dependent simulations, whereas the severity and probability of catastrophe were more important during density-independent simulations. The inclusion of density dependence decreased the probability of extinction, but neither the abruptness nor the inclusion of density dependence were important model parameters. Results of both relative sensitivity analyses that altered each parameter by 10% of its range and life-stage-simulation analyses of deterministic matrix models supported the logistic regression results, indicating that pup survival and its variation were more important than other parameters. But both conventional sensitivity analysis of the stochastic model which changed each parameter by 10% of its mean value and elasticity analyses indicated that adult survival was more important than pup survival. We evaluated the advantages and disadvantages of using logistic regression to analyze the sensitivity of stochastic population viability models and conclude that it is a powerful method because it can address interactions among input parameters and can incorporate the range of parameter variability, although the standardized regression coefficients are not comparable between studies. Model structure, method of analysis, and parameter uncertainty affect the conclusions of sensitivity analyses. Therefore, rigorous model exploration and analysis should be conducted to understand model behavior and management implications. Resumen: Utilizamos la regresión logística como un método de análisis de sensibilidad par a un modelo de análisis de viabilidad poblacional de perros silvestres Africanos ( Lycaon pictus) y comparamos estos resultados con análisis de sensibilidad convencionales de modelos estocásticos y determinísticos. Coeficientes estandarizados de los análisis de regresión logística indicaron que la supervivencia de cachorros explicaba la mayor variabilidad en la probabilidad de extinción, independientemente de que el modelo incorporara la denso-dependencia. La supervivencia de adultos y la desviación estándar de la supervivencia de cachorros fueron los parámetros que siguieron en importancia en simulaciones de denso-dependencia, mientras que la severidad y la probabilidad de catástrofes fueron más importantes durante simulaciones denso-independientes. La inclusión de la denso dependencia disminuyó la probabilidad de extinción, pero ni la severidad ni la inclusión de denso-dependencia fueron parámetros importantes. Resultados de los análisis de sensibilidad relativa que alteraron cada parámetro en 10% de su rango y análisis de la simulación de etapas de vida de modelos matriciales determinísticos apoyaron los resultados de la regresión logística, indicando que la supervivencia de cachorros y su variación fueron más importantes que otros parámetros. Sin embargo, el análisis de sensibilidad convencional del modelo estocástico que cambiaron cada parámetro en 10% de su valor medio y el análisis de elasticidad indicaron que la supervivencia de adultos fue más importante que la supervivencia de cachorros. Evaluamos las ventajas y desventajas de utilizar la regresión logística para analizar la sensibilidad de modelos estocásticos de viabilidad poblacional y concluimos que es un método poderoso porque puede atender interacciones entre parámetros ingresados e incorporar el rango de variabilidad de parámetros, aunque los coeficientes de regresión estandarizada no son comparables entre estudios. La estructura del modelo, el método de análisis y la incertidumbre en los parámetros afectan las conclusiones del análisis de sensibilidad. Por lo tanto, se debe realizar una rigurosa exploración y análisis del modelo para entender su comportamiento y sus implicaciones en el manejo. [source] When density dependence is not instantaneous: theoretical developments and management implicationsECOLOGY LETTERS, Issue 2 2008Irja I. Ratikainen Abstract Most organisms live in changing environments or do not use the same resources at different stages of their lives or in different seasons. As a result, density dependence will affect populations differently at different times. Such sequential density dependence generates markedly different population responses compared to the unrealistic assumption that all events occur simultaneously. Various field studies have also shown that the conditions that individuals experience during one period can influence success and per capita vital rates during the following period. These carry-over effects further complicate any general principles and increase the diversity of possible population dynamics. In this review, we describe how studies of sequential density dependence have diverged in directions that are both taxon-specific and have non-overlapping terminology, despite very similar underlying problems. By exploring and highlighting these similarities, we aim to improve communication between fields, clarify common misunderstandings, and provide a framework for improving conservation and management practices, including sustainable harvesting theory. [source] Diurnal stream habitat use of juvenile Atlantic salmon, brown trout and rainbow trout in winterFISHERIES MANAGEMENT & ECOLOGY, Issue 5 2009J. H. JOHNSON Abstract, The diurnal winter habitat of three species of juvenile salmonids was examined in a tributary of Skaneateles Lake, NY to compare habitat differences among species and to determine if species/age classes were selecting specific habitats. A total of 792 observations were made on the depth, velocity, substrate and cover (amount and type) used by sympatric subyearling Atlantic salmon, subyearling brown trout and subyearling and yearling rainbow trout. Subyearling Atlantic salmon occurred in shallower areas with faster velocities and less cover than the other salmonid groups. Subyearling salmon was also the only group associated with substrate of a size larger than the average size substrate in the study reach during both winters. Subyearling brown trout exhibited a preference for vegetative cover. Compared with available habitat, yearling rainbow trout were the most selective in their habitat use. All salmonid groups were associated with more substrate cover in 2002 under high flow conditions. Differences in the winter habitat use of these salmonid groups have important management implications in terms of both habitat protection and habitat enhancement. [source] Reorganization of a large marine ecosystem due to atmospheric and anthropogenic pressure: a discontinuous regime shift in the Central Baltic SeaGLOBAL CHANGE BIOLOGY, Issue 6 2009CHRISTIAN MÖLLMANN Abstract Marine ecosystems such as the Baltic Sea are currently under strong atmospheric and anthropogenic pressure. Besides natural and human-induced changes in climate, major anthropogenic drivers such as overfishing and anthropogenic eutrophication are significantly affecting ecosystem structure and function. Recently, studies demonstrated the existence of alternative stable states in various terrestrial and aquatic ecosystems. These so-called ecosystem regime shifts have been explained mainly as a result of multiple causes, e.g. climatic regime shifts, overexploitation or a combination of both. The occurrence of ecosystem regime shifts has important management implications, as they can cause significant losses of ecological and economic resources. Because of hysteresis in ecosystem responses, restoring regimes considered as favourable may require drastic and expensive management actions. Also the Baltic Sea, the largest brackish water body in the world ocean, and its ecosystems are strongly affected by atmospheric and anthropogenic drivers. Here, we present results of an analysis of the state and development of the Central Baltic Sea ecosystem integrating hydroclimatic, nutrient, phyto- and zooplankton as well as fisheries data. Our analyses of 52 biotic and abiotic variables using multivariate statistics demonstrated a major reorganization of the ecosystem and identified two stable states between 1974 and 2005, separated by a transition period in 1988,1993. We show the change in Baltic ecosystem structure to have the characteristics of a discontinuous regime shift, initiated by climate-induced changes in the abiotic environment and stabilized by fisheries-induced feedback loops in the food web. Our results indicate the importance of maintaining the resilience of an ecosystem to atmospherically induced environmental change by reducing the anthropogenic impact. [source] The role of vascular risk factors in late onset bipolar disorder,INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 8 2007Hari Subramaniam Abstract Background The association between late life depression and cerebro-vascular risk and cerebro-vascular disease is well established. Do similar links exist with late onset bipolar disorder? Aims and Objectives Patients with early onset (less than 60 years of age) bipolar disorder were compared with those of late onset (aged 60 and above) in relation to cognitive function, physical health and vascular risk factors. Method Cross-sectional survey of elderly bipolar disorder patients (above 65 years) involved with secondary care mental health services. Thirty patients with early onset were compared with 20 patients with a late onset bipolar disorder. Diagnosis of bipolar disorder was according to ICD-10 criteria and without an associated clinical diagnosis of dementia. Assessment of cognition included tests of frontal-executive function, and cerebro-vascular risk was quantified with the Framingham stroke risk score. Results The late onset group had a higher stroke risk score than the early onset group, this difference persisting despite taking age and gender differences into account. However, late onset patients' cognitive function (including frontal lobe tests) and physical health status was no different to the early onset group. Conclusion There is higher ,cerebrovascular risk' in elderly patients with late onset bipolar disorder, compared to patients with an early onset. This suggests that cerebrovascular risk may be an important factor for the expression of bipolar disorders in later life, and has significant management implications for older bipolar patients. Copyright © 2006 John Wiley & Sons, Ltd. [source] Elite hotels: painting a self-portraitINTERNATIONAL JOURNAL OF TOURISM RESEARCH, Issue 2 2001Cailein Gillespie Abstract Commercial hospitality provision arose from a general process of modernisation, the gradual breakdown of the importance of kinship and social obligation relative to a common duty of care for those travelling away from home, and the process of urbanisation. Consequently market demand evolved for the provision of accommodation, food and beverage for those persons temporarily removed from their domestic environment. What is argued in this paper is that the original function of commercial hospitality bears scant resemblance to sophisticated potentialities for socio-economic self-expression, which manifest themselves in the form of the elite hotel sector. The manner in which contemporary consumption of elite hotels revolves around the notion of self, with multiple identities and group affiliations is explored. Conclusions focus on the elite hotel sector as a means of defining self-identities and the management implications therein for the provision of commercial hospitality in elite hotels. Copyright © 2001 John Wiley & Sons, Ltd. [source] Cascading top-down effects of changing oceanic predator abundancesJOURNAL OF ANIMAL ECOLOGY, Issue 4 2009Julia K. Baum Summary 1Top-down control can be an important determinant of ecosystem structure and function, but in oceanic ecosystems, where cascading effects of predator depletions, recoveries, and invasions could be significant, such effects had rarely been demonstrated until recently. 2Here we synthesize the evidence for oceanic top-down control that has emerged over the last decade, focusing on large, high trophic-level predators inhabiting continental shelves, seas, and the open ocean. 3In these ecosystems, where controlled manipulations are largely infeasible, ,pseudo-experimental' analyses of predator,prey interactions that treat independent predator populations as ,replicates', and temporal or spatial contrasts in predator populations and climate as ,treatments', are increasingly employed to help disentangle predator effects from environmental variation and noise. 4Substantial reductions in marine mammals, sharks, and piscivorous fishes have led to mesopredator and invertebrate predator increases. Conversely, abundant oceanic predators have suppressed prey abundances. Predation has also inhibited recovery of depleted species, sometimes through predator,prey role reversals. Trophic cascades have been initiated by oceanic predators linking to neritic food webs, but seem inconsistent in the pelagic realm with effects often attenuating at plankton. 5Top-down control is not uniformly strong in the ocean, and appears contingent on the intensity and nature of perturbations to predator abundances. Predator diversity may dampen cascading effects except where nonselective fisheries deplete entire predator functional groups. In other cases, simultaneous exploitation of predator and prey can inhibit prey responses. Explicit consideration of anthropogenic modifications to oceanic foodwebs should help inform predictions about trophic control. 6Synthesis and applications. Oceanic top-down control can have important socio-economic, conservation, and management implications as mesopredators and invertebrates assume dominance, and recovery of overexploited predators is impaired. Continued research aimed at integrating across trophic levels is needed to understand and forecast the ecosystem effects of changing oceanic predator abundances, the relative strength of top-down and bottom-up control, and interactions with intensifying anthropogenic stressors such as climate change. [source] Modelling the long-term sustainability of indigenous hunting in Manu National Park, Peru: landscape-scale management implications for AmazoniaJOURNAL OF APPLIED ECOLOGY, Issue 4 2009Taal Levi Summary 1. ,Widespread hunting throughout Amazonia threatens the persistence of large primates and other vertebrates. Most studies have used models of limited validity and restricted spatial and temporal scales to assess the sustainability. 2. ,We use human-demographic, game-harvest and game-census data to parameterize a spatially explicit hunting model. We explore how population growth and spread, hunting technology and effort, and source,sink dynamics impact the density of black spider monkeys Ateles chamek over time and space in the rainforests of south-eastern Peru. 3. ,In all scenarios, spider monkey populations, which are vulnerable to hunting, persist in high numbers in much of Manu National Park over the next 50 years. Nonetheless, shotguns cause much more depletion than traditional bow hunting by Matsigenka (Machiguenga) indigenous people. 4. ,Maintenance of the current indigenous lifestyle (dispersed settlements, bow hunting) is unlikely to deplete spider monkeys and, by extension, other fauna, despite rapid human population growth. This helps explain why large, pre-Colombian human populations did not drive large primates to extinction. When guns are used, however, spider monkeys quickly become depleted around even small settlements, with depletion eventually reversing the short-term harvest advantage provided by shotgun hunting. Thus, our models show that when guns are used, limits on settlement numbers can reduce total depletion. 5. ,Synthesis and applications. Our framework lets us visualize the future effects of hunting, population growth, hunting technology and settlement spread in tropical forests. In Manu Park, the continued prohibition of firearms is important for ensuring long-term hunting sustainability. A complementary policy is to negotiate limits on new settlements in return for development aid in existing settlements. The advantage of the latter approach is that settlement numbers are more easily monitored than is hunting effort or technology. Similar policies could help to reduce landscape-scale depletion of prey species in human-occupied reserves and protected areas throughout the Amazon. [source] Conservation and management implications of fine-scale genetic structure of Gulf sturgeon in the Pascagoula River, MississippiJOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2004M. A. Dugo Summary The anadromous Gulf sturgeon occurs along the north central coast of the Gulf of Mexico and is federally listed as threatened. We analyzed fine-scale patterns of Gulf sturgeon population structure, focusing on the Pascagoula River drainage of Mississippi, in reference to movement patterns as determined via telemetry and capture data. We genotyped 361 Gulf sturgeon using eight microsatellite loci including samples from the Pascagoula, Pearl, Escambia, Yellow, Choctawhatchee, and Apalachicola river drainages. Pairwise FST estimates indicated that genetic structure occurs at least at the drainage level. The Pascagoula and Pearl rivers form a western group, demonstrating 100% bootstrap support for a division with drainages to the east. Assignment tests detected non-natal genotypes occurring in all drainages. According to assignment tests, the Pascagoula supports an admixture of individuals, containing minimal influence from drainages to the east (2%) and substantial interaction with the Pearl River (14.1%). The occurrence of Pascagoula River fish in the Pearl was non-reciprocal, observed at 1.1%. After accounting for non-natal genetic diversity within the Pascagoula, there remained a disparity between a pooled Pascagoula group and the only documented spawning site within the drainage located in the Bouie River. We interpret this as an indication of a second genetic stock within the Pascagoula River drainage. Radio telemetry data suggest that spawning likely occurs in the Chickasawhay River, in areas isolated from the Bouie River spawning site by about 350 river kilometers. We emphasize the utility of integrating field and molecular approaches when delineating fine-scale patterns of population structure in anadromous fishes. [source] Previously spawned Atlantic salmon ascend a large subarctic river earlier than their maiden counterpartsJOURNAL OF FISH BIOLOGY, Issue 4 2006E. Niemelä Spawning migration timing of maiden Atlantic salmon Salmo salar and previous spawners was analysed in the catches in 1989,2004 in the large subarctic River Teno in the northernmost parts of Finland and Norway. The hypothesis was that the migration timing of previous spawners and their maiden counterparts is similar, with the migration timing similar between sexes. In most cases, however, previous spawners were observed to migrate into the River Teno and its tributaries earlier than their maiden counterparts. The difference in run timing was especially evident between maiden one-sea-winter (1SW) Atlantic salmon and the corresponding group of previous spawners [1S1, 1 year at sea (1) followed by first spawning (S) and reconditioning period of 1 year (1) at sea and second spawning run] for both sexes in the River Teno and in its two tributaries. The same was also evident between 2SW maiden and 2S1 previous spawning female Atlantic salmon in the River Teno. Females showed earlier spawning migration than males both in previous spawners and maiden Atlantic salmon. Different maiden sea-age classes also showed differences in run timing as multi-sea-winter fish (2,4SW) ascended earlier than 1SW fish but the timing of 1S1 and 2S1 previous spawning females coincided. The results suggest that run timing of Atlantic salmon may not be strictly genetically fixed as previous spawners ascend earlier than they did on their first spawning migration as maiden fish, and indicated that the closeness of the reconditioning area of postspawners to the river of origin resulted in an early ascent. Run timing of different sea-age groups has major management implications if the populations are heavily exploited with numerous fishing methods in different periods of the fishing season, as in the River Teno system. [source] National Cultural Influences on Knowledge Sharing: A Comparison of China and RussiaJOURNAL OF MANAGEMENT STUDIES, Issue 3 2006Snejina Michailova abstract This paper presents a set of theoretical propositions regarding knowledge sharing in China and Russia. We argue that there are important national cultural similarities and differences between the two countries that result in certain similarities and differences in individual knowledge-sharing behaviour in Chinese and Russian organizations. We claim that vertical collectivism and particularistic social relations in China and Russia lead to intensive social relations among organizational members, which facilitate knowledge sharing between in-group members in organizations in both countries. We also maintain that differences in the essence of collectivism as well as in the extent of collectivism in the two cultural contexts lead to different intensities of knowledge sharing in Chinese and Russian organizations. Finally, we discuss theoretical and management implications of this research. [source] Physician attitudes towards ventilatory support for spinal muscular atrophy type 1 in AustralasiaJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 12 2007Nimeshan Geevasinga Background: Without ventilatory support, premature death from respiratory insufficiency is virtually universal in infants with spinal muscular atrophy type 1 (SMA1). With mechanical ventilation, however, long-term survival has been reported from numerous international centres. We aimed to characterize physician attitudes to the various forms of ventilatory support for children with SMA1. Methods: We surveyed neurologists, respiratory physicians, clinical geneticists and intensivists from all major paediatric hospitals in Australia and New Zealand regarding their views on ventilatory management of SMA1. Results: Ninety-two of the 157 (59%) physicians surveyed replied. Respondents included 16 clinical geneticists, 19 intensive care physicians, 28 neurologists and 29 respiratory physicians. Almost half (47%) opposed invasive ventilation of children with SMA1 and respiratory failure precipitated by intercurrent illness. The majority (76%) opposed invasive ventilatory support for chronic respiratory failure in SMA1. In contrast, non-invasive ventilation was felt by 85% to be appropriate for acute respiratory deteriorations, with 49% supporting long-term non-invasive ventilatory support. Most physicians felt that decisions regarding ventilation should be made jointly by parents and doctors, and that hospital Clinical Ethics Committees should be involved in the event of discordant opinion regarding further management. A majority felt that a defined hospital policy would be valuable in guiding management of SMA1. Conclusions: Respiratory support in SMA1 is an important issue with significant ethical, financial and resource management implications. Most physicians in Australian and New Zealand oppose invasive ventilatory support for chronic respiratory failure in SMA1. Non-invasive ventilation is an accepted intervention for acute respiratory decompensation and may have a role in the long-term management of SMA1. Clinical Ethics Committees and institutional policies have a place in guiding physicians and parents in the management of children with SMA1. [source] Models, Assumptions, and Stakeholders: Planning for Water Supply Variability in the Colorado River Basin,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2008Dustin Garrick Abstract:, Declining reservoir storage has raised the specter of the first water shortage on the Lower Colorado River since the completion of Glen Canyon and Hoover Dams. This focusing event spurred modeling efforts to frame alternatives for managing the reservoir system during prolonged droughts. This paper addresses the management challenges that arise when using modeling tools to manage water scarcity under variable hydroclimatology, shifting use patterns, and institutional complexity. Assumptions specified in modeling simulations are an integral feature of public processes. The policymaking and management implications of assumptions are examined by analyzing four interacting sources of physical and institutional uncertainty: inflow (runoff), depletion (water use), operating rules, and initial reservoir conditions. A review of planning documents and model reports generated during two recent processes to plan for surplus and shortage in the Colorado River demonstrates that modeling tools become useful to stakeholders by clarifying the impacts of modeling assumptions at several temporal and spatial scales. A high reservoir storage-to-runoff ratio elevates the importance of assumptions regarding initial reservoir conditions over the three-year outlook used to assess the likelihood of reaching surplus and shortage triggers. An ensemble of initial condition predictions can provide more robust initial conditions estimates. This paper concludes that water managers require model outputs that encompass a full range of future potential outcomes, including best and worst cases. Further research into methods of representing and communicating about hydrologic and institutional uncertainty in model outputs will help water managers and other stakeholders to assess tradeoffs when planning for water supply variability. [source] RATES, RIGHTS, AND REGIONAL PLANNING IN THE METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2002Richard Atwater ABSTRACT: The Metropolitan Water District of Southern California has for more than 70 years shaped the development of an immense urban region. The district's current strategic planning process therefore could have substantial effects on regional water planning and management. The rate restructuring phase of the planning process has produced a multiple component, cost of service based framework. This paper describes that framework as well as some criticisms that have been directed toward it. The rate restructuring was shaped, and for a while stalled, by old disputes among member agencies over rights to water supplied by Metropolitan. That controversy has diverted attention from the resource management implications of the rate structure. This paper presents an alternative future focused approach to regional integrated water resource planning for Southern California based on projections of current trends and anticipation of future events. This discussion raises the question of how regional integrated water resources planning of this sort may proceed, and what role Metropolitan will play in that process. [source] Effects of browsing and grazing on cyclic succession in nutrient-limited ecosystemsJOURNAL OF VEGETATION SCIENCE, Issue 6 2001Jan Bokdam van der Meijden (1990) Abstract. This paper deals with browsing and grazing as forces driving cyclic succession. Between 1989 and 1994 reciprocal transitions between the dwarf shrub Calluna vulgaris and the grass Deschampsia flexuosa were monitored in permanent plots in a cattle grazed grass-rich Dutch heathland on podsolic soils in which tree encroachment was prevented. Heather beetles killed Calluna in four of the nine plots during 1991/1992. The monitoring revealed reciprocal transitions and cycles between Calluna and Deschampsia on a subplot scale. Beetles and cattle had additional and complementary effects on the two competing species. Defoliation by beetles and trampling by cattle-killed Calluna and favoured grass invasion. Grazing and gap creation by cattle in Deschampsia favoured the establishment and recovery of Calluna. Analysis of the causal mechanisms suggests that indirect, resource-mediated herbivory effects may be as important for the replacement processes as direct effects of defoliation and trampling. Herbivory created differential light and nutrient levels in Calluna and Deschampsia gaps. Grazing and browsing improved the resource-capturing abilities of Calluna and its resistance to herbivory and abiotic disturbances. The emerged Calluna-Deschampsia cycle and its driving forces are summarized in a conceptual triangular resource-mediated successional grazing cycle (RSGC) model, a limit cycle involving herbivore-plant-plant resource interactions. It offers a deterministic equilibrium model as alternative for stochastic transitions between the meta-stable states with dominance of Calluna and Deschampsia respectively. The validity range of the RSGC model and its management implications are briefly discussed. [source] Investigation of physical and bathymetric characteristics of Lakes Abaya and Chamo, Ethiopia, and their management implicationsLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2006Seleshi Bekele Awulachew Abstract The purpose of this study was to investigate the physical parameters of Lakes Abaya and Chamo in the Ethiopian rift lakes system, including such physical characteristics as depth, water resources capacity, hydrology, water balances, and impacts of water use and degradation of their watersheds. These parameters have not previously been studied for these two lakes to any significant extent. This study describes the bathymetry survey undertaken for these two lakes, and the morphometric characteristics derived from it. This study is part of a research project developed to provide further details on such parameters as hydrology, water quality, sediment inflows and deposition, lake hydrodynamics and consumptive water uses. The bathymetric survey was conducted, utilizing a combination of global positioning system (GPS) and echo sounder. To calculate the morphometric characteristics, the background lake map was digitized, and the surveyed primary data were developed as digital values. The digital values were interpolated, generating grids of the elevation surface. The elevation area and elevation volume curves (capacity curves) of the two lakes were developed from the digital values, describing the water resources capacity of the lake water basins. The results of this study increase our understanding of the water resources of these two lakes, as well as provide better understanding of their vulnerability to human activities because of their shallow depths. Immediate application of the results, as a basis for continuation of this study, also is highlighted. [source] Spawning success in Atlantic salmon (Salmo salar L.): a long-term DNA profiling-based study conducted in a natural streamMOLECULAR ECOLOGY, Issue 4 2001J. B. Taggart Abstract Spawning success of Atlantic salmon (Salmo salar L.) was investigated, under near-natural conditions, in the Girnock Burn, an 8-km long tributary of the River Dee in Scotland. Employing minisatellite-based DNA profiling, mating outcomes were resolved over three spawning seasons by assigning parentage to progeny samples removed from spawning nests (,redds'). While individual spawning patterns differed markedly, consistent trends were present over the 3 years studied. Multiple spawning was found to be prevalent. More than 50% of anadromous spawners of both sexes contributed to more than one redd. Up to six redds for a single female and seven for a single male were detected. Both sexes ranged extensively. Distance between redds involving the same parent varied from a few metres to > 5 km. Distances > 1 km were common. Both males and females ranged to a similar extent. Range limit was not correlated to fish size. Pairs were not monogamous, both males and females mating with different partners at different sites. Size assortative mating was apparent among 1991 spawners but was not detected for 1992 or 1995. Redd superimposition was found to be common (17,22% of redds over the 3 years), although it was not correlated to the number of anadromous spawners present. High levels of nonanadromous mature parr mating success (40,50% of total progeny sampled) were recorded, and these likely contribute greatly to the effective population size. The relevance of these findings at the individual and population level is discussed, with particular reference to management implications. [source] Polymorphic microsatellite markers for paternity assessment in southern calamari Sepioteuthis australis (Cephalopoda: Loliginidae)MOLECULAR ECOLOGY RESOURCES, Issue 4 2003L. M. Van Camp Abstract Recent decades have seen the fast growth of cephalopod fisheries but their management is compromised by the critical gaps in our knowledge of cephalopod life histories. Molecular markers are invaluable tools for studying the evolutionary significance and management implications of variation in mating systems. We have developed seven polymorphic microsatellite loci for mating system analysis in the southern calamari Sepioteuthis australis Quoy & Gaimard 1833 using magnetic enrichment and colony hybridization techniques. Observed heterozygosities range from 32% to 100% and will have sufficient power to examine the relative success of alternate mating strategies in S. australis. [source] Customization: Impact on Product and Process PerformancePRODUCTION AND OPERATIONS MANAGEMENT, Issue 4 2005Vishwanath G. Hegde Manufacturing capability has often been viewed to be a major obstacle in achieving higher levels of customization. Companies follow various strategies ranging from equipment selection to order process management to cope with the challenges of increased customization. We examined how the customization process affects product performance and conformance in the context of a design-to-order (DTO) manufacturer of industrial components. Our competing risk hazard function model incorporates two thresholds, which we define as mismatch and manufacturing thresholds. Product performance was adversely affected when the degree of customization exceeded the mismatch threshold. Likewise, product conformance eroded when the degree of customization exceeded the manufacturing threshold. Relative sizes of the two thresholds have management implications for the subsequent investments to improve customization capabilities. Our research developed a rigorous framework to address two key questions relevant to the implementation of product customization: (1) what degrees of customization to offer, and (2) how to customize the product design process. [source] Brand community: Drivers and outcomes,PSYCHOLOGY & MARKETING, Issue 4 2010Nicola Stokburger-Sauer Groups of users and admirers of a brand who engage jointly in group actions to accomplish collective goals and/or to express mutual sentiments and commitments are known as brand communities. Lately, brand communities have been a heavily researched topic in marketing science. While the positive consequences of brand communities are well documented in the literature, little is known about how brand communities can be facilitated and how consumer,brand relationships can be fostered. This research empirically assesses the relevance of offline (i.e., events) and online marketing management tools (i.e., Web sites with online bulletin boards and online expert chats) to strengthen brand communities by facilitating shared customer experiences and multi-way interactions. Additionally, the importance of consumer,brand identification as a consequence of such relationship-building activities is investigated, and the outcomes of a consumer's identification with a brand are analyzed. Important management implications can be derived. © 2010 Wiley Periodicals, Inc. [source] Low genetic variability of the white-clawed crayfish in the Iberian Peninsula: its origin and management implicationsAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2008Javier Diéguez-Uribeondo Abstract 1.A study on the genetic variability of the white-clawed crayfish was carried out based on mitochondrial cytochrome oxidase subunit I gene sequences. The sequences applied were more informative regarding white-clawed crayfish genetic variability than others previously used. 2.Two haplotypes were found to exist in the Iberian Peninsula. The haplotypes exhibit a strong geographic subdivision (,ST=0.83). One of the Iberian haplotypes was similar to north Italian haplotypes and the second differed in only one mutation. This pattern of genetic variability contrasts with those found in glacial refugial areas of France, Italy and the Balkan Peninsula. 3.Two hypotheses on the origin of the white-clawed crayfish in the Iberian Peninsula are discussed: (i) one based on an anthropogenic origin, and (ii) a second based on a successive number of postglacial ancient and recent bottlenecks, i.e. the disjunction between Iberian and Italian populations of white-clawed crayfish species is due to competition between A. italicus and A. pallipes, in addition to the impact of crayfish plague and human translocations. 4.New references for the white-clawed crayfish in the Iberian Peninsula were found in medieval and Arabic texts. The results show that this species has been thriving in this peninsula since ancient periods and that its indigenous status should not be questioned. 5.Conservation action and plans should consider the low genetic diversity as a limitation for farm-raising specimens more adapted and resistant to changing environments and diseases. Copyright © 2007 John Wiley & Sons, Ltd. [source] Productive performance in fisheries: modeling, measurement, and managementAUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 3 2010Catherine J. Morrison Paul We overview the roles of production structure models in measuring fisheries' productive performance to provide policy-relevant guidance for fishery managers and analysts. In particular, we summarize the literature on the representation and estimation of production structure models to construct productive performance measures for fisheries, with a focus on parametric empirical applications and on the management implications of these kinds of measures. [source] Pretherapy quantitative measurement of circulating Epstein,Barr virus DNA is predictive of posttherapy distant failure in patients with early-stage nasopharyngeal carcinoma of undifferentiated typeCANCER, Issue 2 2003Sing-fai Leung M.D. Abstract BACKGROUND Patients with International Union Against Cancer (UICC) Stage I,II nasopharyngeal carcinoma (NPC) appear to have a relatively favorable prognosis and generally are excluded from trials of combined modality treatment. More recently, plasma/serum cell-free Epstein-Barr virus (EBV) DNA has been shown to be measurable in the majority of NPC patients at the time of diagnosis, and appears to have prognostic significance. However, within Stage I-II disease, in which failure events are infrequent, the prognostic impact of the pretreatment EBV DNA level has not been addressed to our knowledge. This issue has management implications because different therapeutic strategies currently are employed for patients with good-risk and those with poor-risk NPC. METHODS A cohort of 90 patients with UICC Stage I-II NPC (World Health Organization Grade 2/3 histology) had their pretherapy plasma/serum EBV DNA levels determined by a quantitative polymerase chain reaction assay and correlated with the probability of posttherapy failure. All patients received radiation therapy only, except for three patients who also received concurrent chemotherapy. Kaplan,Meier plots of the probability of locoregional failure, distant failure, and cancer-specific survival were compared with reference to clinical stage and EBV DNA levels. RESULTS With a median follow-up time of 45 months, 12 patients and 7 patients, respectively, had developed locoregional and distant failures, including 2 patients with both local and distant failures. Patients with distant failure had significantly higher pretherapy EBV DNA levels than those without failure (a median of 13,219 copies/mL [interquatile-range, 274,635 copies/mL] vs. a median of 423 copies/mL [interquatile-range, 2753 copies/mL]). The probability of distant failure was significantly higher in patients with high (> 4000 copies/mL plasma) compared with low EBV DNA levels (P = 0.0001, log-rank test) and for Stage IIB disease compared with Stage I and Stage IIA disease combined (P = 0.0149, log-rank test), but was not significantly different between patients with Stage II and those with Stage I disease. The risks of locoregional failure were not significantly different between patients with high and those with low EBV DNA levels, and also was not significantly different between clinical substages. Approximately 35% of patients with Stage IIB disease were in the at-risk group for distant failure, as identified by high EBV DNA levels. CONCLUSIONS Within a group of patients with UICC Stage I-II NPC, the pretherapy plasma EBV DNA level was found to identify a poor-risk group with a probability of distant failure similar to that of patients with advanced stage disease. This group of patients may warrant management considerations currently applicable only to cases of Stage III-IV disease. The prognostic significance of designating Stage IIB disease as per the 1997 UICC staging was confirmed, although the pretherapy EBV DNA level appears to be a more powerful prognostic discriminator in patients with early-stage NPC. Cancer 2003;98:288,91. © 2003 American Cancer Society. DOI 10.1002/cncr.11496 [source] |