967 resultados para Current patterns
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Sustaining irrigated agriculture to meet food production needs while maintaining aquatic ecosystems is at the heart of many policy debates in various parts of the world, especially in arid and semi-arid areas. Researchers and practitioners are increasingly calling for integrated approaches, and policy-makers are progressively supporting the inclusion of ecological and social aspects in water management programs. This paper contributes to this policy debate by providing an integrated economic-hydrologic modeling framework that captures the socio-economic and environmental effects of various policy initiatives and climate variability. This modeling integration includes a risk-based economic optimization model and a hydrologic water management simulation model that have been specified for the Middle Guadiana basin, a vulnerable drought-prone agro-ecological area with highly regulated river systems in southwest Spain. Namely, two key water policy interventions were investigated: the implementation of minimum environmental flows (supported by the European Water Framework Directive, EU WFD), and a reduction in the legal amount of water delivered for irrigation (planned measure included in the new Guadiana River Basin Management Plan, GRBMP, still under discussion). Results indicate that current patterns of excessive water use for irrigation in the basin may put environmental flow demands at risk, jeopardizing the WFD s goal of restoring the ?good ecological status? of water bodies by 2015. Conflicts between environmental and agricultural water uses will be stressed during prolonged dry episodes, and particularly in summer low-flow periods, when there is an important increase of crop irrigation water requirements. Securing minimum stream flows would entail a substantial reduction in irrigation water use for rice cultivation, which might affect the profitability and economic viability of small rice-growing farms located upstream in the river. The new GRBMP could contribute to balance competing water demands in the basin and to increase economic water productivity, but might not be sufficient to ensure the provision of environmental flows as required by the WFD. A thoroughly revision of the basin s water use concession system for irrigation seems to be needed in order to bring the GRBMP in line with the WFD objectives. Furthermore, the study illustrates that social, economic, institutional, and technological factors, in addition to bio-physical conditions, are important issues to be considered for designing and developing water management strategies. The research initiative presented in this paper demonstrates that hydro-economic models can explicitly integrate all these issues, constituting a valuable tool that could assist policy makers for implementing sustainable irrigation policies.
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Published literature reports rates of dietary supplement usage by individuals aged 60 years or more to be 16−60%. Prevalence figures are dependent on the population studied and the method of data collection. In general, older supplement users are female, Caucasian and well educated, with healthier lifestyle practices than non-supplement users, and they are less likely to be overweight or to smoke. Neither income nor self-rated health status are reliable predictors of supplement use in this group. In many cases older supplement users report higher intakes of several micronutrients from food than older non-supplement users. Current patterns of supplement use by the older person reveal that although they consume a range of products, they do not supplement with nutrients that are of particular benefit to them. The supplements most commonly consumed by individuals aged 60 years and over are multivitamins and minerals, vitamin C and vitamin E preparations. There is insufficient data to quantify the dosage, frequency and duration of supplement use by the older population. Obtaining this information and data about herbal medicine use is an important step towards minimising the risk of drug–nutrient–herbal interactions. Identifying the health professionals who monitor the appropriateness and safety of supplement use in older individuals, particularly given the already high use of medication in this population, also needs to be a focus of future utilisation investigations. This systematic review of the literature published between 1982 and 2003 aims to measure the patterns of dietary supplement use by community-living individuals aged 60 years and over and to profile the characteristics of older supplement users.
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Background: Early detection of melanoma has been encouraged in Queensland for many years, yet little is known about the patterns of detection and the way in which they relate to tumor thickness. Objective: Our purpose was to describe current patterns of melanoma detection in Queensland. Methods: This was a population-based study, comprising 3772 Queensland residents diagnosed with a histologically confirmed melanoma between 2000 and 2003. Results: Almost half (44.0%) of the melanomas were detected by the patients themselves, with physicians detecting one fourth (25.3%) and partners one fifth (18.6%). Melanomas detected by doctors were more likely to be thin (\0.75 mm) than those detected by the patient or other layperson. Melanomas detected during a deliberate skin examination were thinner than those detected incidentally. Limitations: Although a participation rate of 78% was achieved, as in any survey, nonresponse bias cannot be completely excluded, and the ability of the results to be generalized to other geographical areas is unknown. Conclusion: There are clear differences in the depth distribution of melanoma in terms of method of detection and who detects the lesions that are consistent with, but do not automatically lead to, the conclusion that promoting active methods of detection may be beneficial. ( J Am Acad Dermatol 2006;54:783-92.)
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This paper examines the potential for the development of patient services that could arise from the co-location of pharmacies with medical practices in the new "one-stop" centres. A review of the pharmacy-specific literature shows limited understanding of influence of location upon service development and highlights a tension between the professional and commercial drives. The aim of the survey of health centre pharmacists was to describe the current patterns of integration in the primary health care team. The study demonstrates that co-location offers opportunities but that there are barriers linked to the loss of traditional commercial activity. © 2003 Elsevier Science Ltd. All rights reserved.
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This study aimed firstly to investigate current patterns of language use amongst young bilinguals in Birmingham and secondly to examine the relationship between this language use and educational achievement. The research then focussed on various practices, customs and attitudes which would favour the attrition or survival of minority languages in the British situation. The data necessary to address this question was provided by a sample of three hundred and seventy-four 16-19 year olds, studying in Birmingham schools and colleges during the period 1987-1990 and drawn from the main linguistic minority communities in Birmingham. The research methods chosen were both quantitative and qualitative. The study found evidence of ethnolinguistic vitality amongst many of the linguistic minority communities in Birmingham: a number of practices and a range of attitudes indicate that linguistic diversity may continue and that a stable diglossic situation may develop in some instances, particularly where demographical and religious factors lead to closeness of association. Where language attrition is occurring it is often because of the move from a less prestigious minority language or dialect to a more prestigious minority language in addition to pressures from English. The educational experience of the sample indicates that literacy and formal language study are of key importance if personal bilingualism is to be experienced as an asset; high levels of oral proficiency in the L1 and L2 do not, on their own, necessarily correlate with positive educational benefit. The intervening variable associated with educational achievement appears to be the formal language learning process and literacy. A number of attitudes and practices, including the very close associations maintained with some of the countries of origin of the families, were seen to aid or hinder first language maintenance and second language acquisition.
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Tropical coastal marine ecosystems including mangroves, seagrass beds and coral reef communities are undergoing intense degradation in response to natural and human disturbances, therefore, understanding the causes and mechanisms present challenges for scientist and managers. In order to protect our marine resources, determining the effects of nutrient loads on these coastal systems has become a key management goal. Data from monitoring programs were used to detect trends of macroalgae abundances and develop correlations with nutrient availability, as well as forecast potential responses of the communities monitored. Using eight years of data (1996–2003) from complementary but independent monitoring programs in seagrass beds and water quality of the Florida Keys National Marine Sanctuary (FKNMS), we: (1) described the distribution and abundance of macroalgae groups; (2) analyzed the status and spatiotemporal trends of macroalgae groups; and (3) explored the connection between water quality and the macroalgae distribution in the FKNMS. In the seagrass beds of the FKNMS calcareous green algae were the dominant macroalgae group followed by the red group; brown and calcareous red algae were present but in lower abundance. Spatiotemporal patterns of the macroalgae groups were analyzed with a non-linear regression model of the abundance data. For the period of record, all macroalgae groups increased in abundance (Abi) at most sites, with calcareous green algae increasing the most. Calcareous green algae and red algae exhibited seasonal pattern with peak abundances (Φi) mainly in summer for calcareous green and mainly in winter for red. Macroalgae Abi and long-term trend (mi) were correlated in a distinctive way with water quality parameters. Both the Abi and mi of calcareous green algae had positive correlations with NO3−, NO2−, total nitrogen (TN) and total organic carbon (TOC). Red algae Abi had a positive correlation with NO2−, TN, total phosphorus and TOC, and the mi in red algae was positively correlated with N:P. In contrast brown and calcareous red algae Abi had negative correlations with N:P. These results suggest that calcareous green algae and red algae are responding mainly to increases in N availability, a process that is happening in inshore sites. A combination of spatially variable factors such as local current patterns, nutrient sources, and habitat characteristics result in a complex array of the macroalgae community in the seagrass beds of the FKNMS.
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Aim: Alcohol consumption is a leading cause of global suffering. The harms caused by alcohol to the individual, their peers and the society in which they live provokes public health concern. Elevated levels of consumption and consequences have been noted in those aged 18-29 years. University students represent a unique subsection of society within this age group. University authorities have attempted to tackle this issue throughout the past decade. However, the issue persists. Thus, the aim of this study is to contribute to the evidence base for policy and practice in relation to alcohol harm reduction among third-level students in Ireland. Methods: A mixed methods approach was employed. A systematic review of the prevalence of hazardous alcohol consumption among university students in Ireland and the United Kingdom from 2002 to 2014 was conducted. In addition, a narrative synthesis of studies of drinking types evidenced among youths in western societies was undertaken. A cross-sectional study focused on university students’ health and lifestyle behaviours with particular reference to alcohol consumption was undertaken using previously validated instruments. Undergraduate students registered to one university in Ireland were recruited using two separate modes; classroom and online. Studies investigated the impact of mode of data collection, the prevalence of hazardous alcohol consumption and resultant adverse consequences for mental health and wellbeing. In addition a study using a Q-methodology approach was undertaken to gain a deeper understanding of the cultural factors influencing current patterns of alcohol consumption. Data were analysed using IBM SPPS statistics 20, Stata 12, MPLUS and PQ Method. Results: The literature review focusing on students’ alcohol consumption found that there has been both an increase in hazardous alcohol consumption among university students and a convergence of male and female drinking patterns throughout the past decade. Updating this research, the thesis found that two-thirds of university students consume alcohol at a hazardous level, detailing the range of adverse consequences reported by university students in Ireland. Finally, the heterogeneous nature of this drinking was described in a narrative synthesis exposing six types of consumption. The succeeding chapters develop this review further by describing three typologies of consumption, two quantitative and one quali-quantilogical. The quantitative typology describes three types of drinking for men (realistic hedonist, responsible conformer and guarded drinker) and four types for women (realistic hedonist, peer-influenced, responsible conformer and guarded drinker). The quali-quantilogical approach describes four types of consumption. These are defined as the ‘guarded drinker’, the ‘calculated hedonist’, the ‘peer-influenced drinker’ and the ‘inevitable binger’. Discussion: The findings of this thesis highlight the scale of the issue and provide up-to-date estimates of alcohol consumption among university students in Ireland. Hazardous alcohol consumption is associated with a range of harms to self and harms to others in proximity to the alcohol consumer. The classification of drinkers into types signal the necessity for university management, health promotion practitioners and public health policy makers to tackle this issue using a multi-faceted approach.
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The paper explores competitive balance in top tier English league football from its inception in 1888. It examines the extent to which finishing in the top four positions in successive seasons is the preserve of a small number of clubs. Using a range of statistical measures, the analysis shows that the current high levels of competitive imbalance are not new phenomena. The overall pattern approximates a ‘U curve’: current patterns parallel those in the 1890s. In the early years of English league football, differences in resources between clubs soon became apparent. Clubs from the larger conurbations generated consistently larger revenues than their counterparts in the smaller industrial towns. This was primarily the result of the larger crowds that they could attract to their home games. This enabled them to entice the best players to their clubs away from their smaller rivals. The introduction of the maximum wage in 1901 and the transfer system helped to stem these increasing inequalities between clubs. This coincided with a massive wave of new stadia construction which enabled all the clubs to compete on an increasingly level playing field. These conjunctural changes to English football before 1915 produced the era of relatively competitive football during the inter-war years. This continued until the abolition of the maximum wage in 1961. Since that time, competitive balance has reversed and become increasingly restricted. English top-tier football has re-entered an era of extreme competitive imbalance.
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A recent focus on contemporary evolution and the connections between communities has sought to more closely integrate the fields of ecology and evolutionary biology. Studies of coevolutionary dynamics, life history evolution, and rapid local adaptation demonstrate that ecological circumstances can dictate evolutionary trajectories. Thus, variation in species identity, trait distributions, and genetic composition may be maintained among ecologically divergent habitats. New theories and hypotheses (e.g., metacommunity theory and the Monopolization hypothesis) have been developed to understand better the processes occurring in spatially structured environments and how the movement of individuals among habitats contributes to ecology and evolution at broader scales. As few empirical studies of these theories exist, this work seeks to further test these concepts. Spatial and temporal dispersal are the mechanisms that connect habitats to one another. Both processes allow organisms to leave conditions that are suboptimal or unfavorable, and enable colonization and invasion, species range expansion, and gene flow among populations. Freshwater zooplankton are aquatic crustaceans that typically develop resting stages as part of their life cycle. Their dormant propagules allow organisms to disperse both temporally and among habitats. Additionally, because a number of species are cyclically parthenogenetic, they make excellent model organisms for studying evolutionary questions in a controlled environment. Here, I use freshwater zooplankton communities as model systems to explore the mechanisms and consequences of dispersal and to test these nascent theories on the influence of spatial structure in natural systems. In Chapter one, I use field experiments and mathematical models to determine the range of adult zooplankton dispersal over land and what vectors are moving zooplankton. Chapter two focuses on prolonged dormancy of one aquatic zooplankter, Daphnia pulex. Using statistical models with field and mesocosm experiments, I show that variation in Daphnia dormant egg hatching is substantial among populations in nature, and some of that variation can be attributed to genetic differences among the populations. Chapters three and four explore the consequences of dispersal at multiple levels of biological organization. Chapter three seeks to understand the population level consequences of dispersal over evolutionary time on current patterns of population genetic differentiation. Nearby populations of D. pulex often exhibit high population genetic differentiation characteristic of very low dispersal. I explore two alternative hypotheses that seek to explain this pattern. Finally, chapter four is a case study of how dispersal has influenced patterns of variation at the community, trait and genetic levels of biodiversity in a lake metacommunity.
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Community-level patterns of functional traits relate to community assembly and ecosystem functioning. By modelling the changes of different indices describing such patterns - trait means, extremes and diversity in communities - as a function of abiotic gradients, we could understand their drivers and build projections of the impact of global change on the functional components of biodiversity. We used five plant functional traits (vegetative height, specific leaf area, leaf dry matter content, leaf nitrogen content and seed mass) and non-woody vegetation plots to model several indices depicting community-level patterns of functional traits from a set of abiotic environmental variables (topographic, climatic and edaphic) over contrasting environmental conditions in a mountainous landscape. We performed a variation partitioning analysis to assess the relative importance of these variables for predicting patterns of functional traits in communities, and projected the best models under several climate change scenarios to examine future potential changes in vegetation functional properties. Not all indices of trait patterns within communities could be modelled with the same level of accuracy: the models for mean and extreme values of functional traits provided substantially better predictive accuracy than the models calibrated for diversity indices. Topographic and climatic factors were more important predictors of functional trait patterns within communities than edaphic predictors. Overall, model projections forecast an increase in mean vegetation height and in mean specific leaf area following climate warming. This trend was important at mid elevation particularly between 1000 and 2000 m asl. With this study we showed that topographic, climatic and edaphic variables can successfully model descriptors of community-level patterns of plant functional traits such as mean and extreme trait values. However, which factors determine the diversity of functional traits in plant communities remains unclear and requires more investigations.
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Background: There may be a considerable gap between LDL cholesterol (LDL-C) and blood pressure (BP) goal values recommended by the guidelines and results achieved in daily practice. Design Prospective cross-sectional survey of cardiovascular disease risk profiles and management with focus on lipid lowering and BP lowering in clinical practice. Methods: In phase 1, the cardiovascular risk of patients with known lipid profile visiting their general practitioner was anonymously assessed in accordance to the PROCAM-score. In phase 2, high-risk patients who did not achieve LDL-C goal less than 2.6 mmol/l in phase 1 could be further documented. Results: Six hundred thirty-five general practitioners collected the data of 23 892 patients with known lipid profile. Forty percent were high-risk patients (diabetes mellitus or coronary heart disease or PROCAM-score >20%), compared with 27% estimated by the physicians. Goal attainment rate was almost double for BP than for LDL-C in high-risk patients (62 vs. 37%). Both goals were attained by 25%. LDL-C values in phase 1 and 2 were available for 3097 high-risk patients not at LDL-C goal in phase 1; 32% of patients achieved LDL-C goal of less than 2.6 mmol/l after a mean of 17 weeks. The most successful strategies for LDL-C reduction were implemented in only 22% of the high-risk patients. Conclusion: Although patients at high cardiovascular risk were treated more intensively than low or medium risk patients, the majority remained insufficiently controlled, which is an incentive for intensified medical education. Adequate implementation of Swiss and International guidelines would expectedly contribute to improved achievement of LDL-C and BP goal values in daily practice.
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Includes bibliography
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There may be a considerable gap between LDL cholesterol (LDL-C) and blood pressure (BP) goal values recommended by the guidelines and results achieved in daily practice.