3,251 research outputs found
Integrating Species Traits into Species Pools
Despite decades of research on the species‐pool concept and the recent explosion of interest in trait‐based frameworks in ecology and biogeography, surprisingly little is known about how spatial and temporal changes in species‐pool functional diversity (SPFD) influence biodiversity and the processes underlying community assembly. Current trait‐based frameworks focus primarily on community assembly from a static regional species pool, without considering how spatial or temporal variation in SPFD alters the relative importance of deterministic and stochastic assembly processes. Likewise, species‐pool concepts primarily focus on how the number of species in the species pool influences local biodiversity. However, species pools with similar richness can vary substantially in functional‐trait diversity, which can strongly influence community assembly and biodiversity responses to environmental change. Here, we integrate recent advances in community ecology, trait‐based ecology, and biogeography to provide a more comprehensive framework that explicitly considers how variation in SPFD, among regions and within regions through time, influences the relative importance of community assembly processes and patterns of biodiversity. First, we provide a brief overview of the primary ecological and evolutionary processes that create differences in SPFD among regions and within regions through time. We then illustrate how SPFD may influence fundamental processes of local community assembly (dispersal, ecological drift, niche selection). Higher SPFD may increase the relative importance of deterministic community assembly when greater functional diversity in the species pool increases niche selection across environmental gradients. In contrast, lower SPFD may increase the relative importance of stochastic community assembly when high functional redundancy in the species pool increases the influence of dispersal history or ecological drift. Next, we outline experimental and observational approaches for testing the influence of SPFD on assembly processes and biodiversity. Finally, we highlight applications of this framework for restoration and conservation. This species‐pool functional diversity framework has the potential to advance our understanding of how local‐ and regional‐scale processes jointly influence patterns of biodiversity across biogeographic regions, changes in biodiversity within regions over time, and restoration outcomes and conservation efforts in ecosystems altered by environmental change
Occupational therapy for people with psychotic conditions in community settings: a pilot randomized controlled trial
OBJECTIVES: To investigate the effectiveness of a long established intervention, occupational therapy for people with psychotic conditions, and to inform future research designs.
DESIGN: A pilot randomized controlled trial.
SETTING: Two community mental health teams in a UK city.
PARTICIPANTS: Forty-four adults with schizophrenia or other psychotic conditions, and functional problems.
INTERVENTIONS: Twelve months of individualized occupational therapy in community settings, as an adjunct to usual care and compared to treatment as usual. A two to one randomization ratio was used in favour of occupational therapy.
OUTCOME MEASURES: Social Functioning Scale, Scale for the Assessment of Negative Symptoms and employment.
RESULTS: Both groups' scores on Social Functioning Scale and Scale for the Assessment of Negative Symptoms showed significant improvement over 12 months. The Social Functioning Scale overall mean difference for occupational therapy was 2.33, P=0.020 and for treatment as usual was 6.17, P=0.023. The Scale for the Assessment of Negative Symptoms total mean difference for occupational therapy was -16.25, P<0.001 and for treatment as usual was -17.36, P= 0.011. There were no differences between the two groups on any of the outcome measures. After 12 months the occupational therapy group showed clinically significant improvements that were not apparent in the control group. These were in four subscales of the Social Functioning Scale: relationships, independence performance, independence competence and recreation. Out of 30 people receiving occupational therapy those with a clinical level of negative symptoms reduced from 18 (64%) to 13 (46%), P=0.055.
CONCLUSION: This pilot study suggested that individualized occupatio
Sustainable risk management of emerging contaminants in municipal wastewaters
This article is available open access through the publisher’s website at the link below. Copyright @ 2009 The Royal Society.The presence of emerging contaminants in municipal wastewaters, particularly endocrine-disrupting compounds such as oestrogenic substances, has been the focus of much public concern and scientific attention in recent years. Due to the scientific uncertainty still surrounding their effects, the Precautionary Principle could be invoked for the interim management of potential risks. Therefore, precautionary prevention risk-management measures could be employed to reduce human exposure to the compounds of concern. Steroid oestrogens are generally recognized as the most significant oestrogenically active substances in domestic sewage effluent. As a result, the UK Environment Agency has championed a ‘Demonstration Programme’ to investigate the potential for removal of steroid oestrogens and alkylphenol ethoxylates during sewage treatment. Ecological and human health risks are interdependent, and ecological injuries may result in increased human exposures to contaminants or other stressors. In this context of limiting exposure to potential contaminants, examining the relative contribution of various compounds and pathways should be taken into account when identifying effective risk-management measures. In addition, the explicit use of ecological objectives within the scope of the implementation of the EU Water Framework Directive poses new challenges and necessitates the development of ecosystem-based decision tools. This paper addresses some of these issues and proposes a species sensitivity distribution approach to support the decision-making process related to the need and implications of sewage treatment work upgrade as risk-management measures to the presence of oestrogenic compounds in sewage effluent
Set it in Stone: Investing in 21st Century Broadband in New Hampshire to Secure Telehealth for All Residents
Exact Bayesian curve fitting and signal segmentation.
We consider regression models where the underlying functional relationship between the response and the explanatory variable is modeled as independent linear regressions on disjoint segments. We present an algorithm for perfect simulation from the posterior distribution of such a model, even allowing for an unknown number of segments and an unknown model order for the linear regressions within each segment. The algorithm is simple, can scale well to large data sets, and avoids the problem of diagnosing convergence that is present with Monte Carlo Markov Chain (MCMC) approaches to this problem. We demonstrate our algorithm on standard denoising problems, on a piecewise constant AR model, and on a speech segmentation problem
Critical elements in the application of water quality standards to wetlands : classification system, beneficial use designation and the identification of exceptional wetlands
Securing recruitment and obtaining informed consent in minority ethnic groups in the UK
Background: Previous health research has often explicitly excluded individuals from minority
ethnic backgrounds due to perceived cultural and communication difficulties, including studies
where there might be language/literacy problems in obtaining informed consent. This study
addressed these difficulties by developing audio-recorded methods of obtaining informed consent
and recording data. This report outlines 1) our experiences with securing recruitment to a
qualitative study investigating alternative methods of data collection, and 2) the development of a
standardised process for obtaining informed consent from individuals from minority ethnic
backgrounds whose main language does not have an agreed written form.
Methods: Two researchers from South Asian backgrounds recruited adults with Type 2 diabetes
whose main language was spoken and not written, to attend a series of focus groups. A screening
tool was used at recruitment in order to assess literacy skills in potential participants. Informed
consent was obtained using audio-recordings of the patient information and recording patients'
verbal consent. Participants' perceptions of this method of obtaining consent were recorded.
Results: Recruitment rates were improved by using telephone compared to face-to-face methods.
The screening tool was found to be acceptable by all potential participants. Audio-recorded
methods of obtaining informed consent were easy to implement and accepted by all participants.
Attrition rates differed according to ethnic group. Snowballing techniques only partly improved
participation rates.
Conclusion: Audio-recorded methods of obtaining informed consent are an acceptable
alternative to written consent in study populations where literacy skills are variable. Further
exploration of issues relating to attrition is required, and a range of methods may be necessary in
order to maximise response and participation
High School Exit Examinations: When Do Learning Effects Generalize?
This paper reviews international and domestic evidence on the effects of three types of high school exit exam systems: voluntary curriculum-based external exit exams, universal curriculum-based external exit exam systems and minimum competency tests that must be passed to receive a regular high school diploma. The nations and provinces that use Universal CBEEES (and typically teacher grades as well) to signal student achievement have significantly higher achievement levels and smaller differentials by family background than otherwise comparable jurisdictions that base high stakes decisions on voluntary college admissions tests and/or teacher grades. The introduction of Universal CBEEES in New York and North Carolina during the 1990s was associated with large increases in math achievement on NAEP tests. Research on MCTs and high school accountability tests is less conclusive because these systems are new and have only been implemented in one country. Cross-section studies using a comprehensive set of controls for family background have not found that students in MCT states score higher on audit tests like the NAEP that carry no stakes for the test taker. The analysis reported in table 1 tells us that the five states that introduced MCTs during the 1990s had significantly larger improvements on NAEP tests than states that made no change in their student accountability regime. The gains, however, are smaller than for the states introducing Universal CBEEES. New York and North Carolina. The most positive finding about MCTs is that students in MCT states earn significantly more during the first eight years after graduation than comparable students in other states suggesting that MCTs improve employer perceptions of the quality of the recent graduates of local high schools
The Impact of EEP Removal on U.S. Wheat
The Export Enhancement Program (EEP) was initiated under the Food Security Act of 1985 to offset the adverse effects of unfair trade practices on U.S. exports and to support U.S. prices. More recently, EEP has been constrained by both GATT and the FAIR Act. This study measures the impacts of the elimination of the EEP on U.S. wheat exports and prices over the coming 10-year period. The commodity trade models at the Food and Agricultural Policy Research Institute (FAPRI) are used to analyze the policy question
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