7,034 research outputs found
Recovery from psychosis : physical health, antipsychotic medication and the daily dilemmas for mental health nurses
This paper considers some of the dilemmas experienced by Mental Health Nurses everyday when faced with the seemingly conflicting relationships that exist between recovery, antipsychotics and the physical health of people experiencing psychosis. We examine the role of antipsychotics in the process of recovery from psychosis and argue that Mental Health Nursing’s laudable shift away from the medical model towards the concept of self-defined personal recovery should not result in overlooking the importance of physical health and medication management. Mental Health Nurses have a responsibility to help services users make an informed choice about treatment; this exchange of information should be based on the best available evidence rather than philosophical values or personal opinion
The strength and timing of the mitochondrial bottleneck in salmon suggests a conserved mechanism in vertebrates
In most species mitochondrial DNA (mtDNA) is inherited maternally in an apparently clonal fashion, although how this is achieved remains uncertain. Population genetic studies show not only that individuals can harbor more than one type of mtDNA (heteroplasmy) but that heteroplasmy is common and widespread across a diversity of taxa. Females harboring a mixture of mtDNAs may transmit varying proportions of each mtDNA type (haplotype) to their offspring. However, mtDNA variants are also observed to segregate rapidly between generations despite the high mtDNA copy number in the oocyte, which suggests a genetic bottleneck acts during mtDNA transmission. Understanding the size and timing of this bottleneck is important for interpreting population genetic relationships and for predicting the inheritance of mtDNA based disease, but despite its importance the underlying mechanisms remain unclear. Empirical studies, restricted to mice, have shown that the mtDNA bottleneck could act either at embryogenesis, oogenesis or both. To investigate whether the size and timing of the mitochondrial bottleneck is conserved between distant vertebrates, we measured the genetic variance in mtDNA heteroplasmy at three developmental stages (female, ova and fry) in chinook salmon and applied a new mathematical model to estimate the number of segregating units (N(e)) of the mitochondrial bottleneck between each stage. Using these data we estimate values for mtDNA Ne of 88.3 for oogenesis, and 80.3 for embryogenesis. Our results confirm the presence of a mitochondrial bottleneck in fish, and show that segregation of mtDNA variation is effectively complete by the end of oogenesis. Considering the extensive differences in reproductive physiology between fish and mammals, our results suggest the mechanism underlying the mtDNA bottleneck is conserved in these distant vertebrates both in terms of it magnitude and timing. This finding may lead to improvements in our understanding of mitochondrial disorders and population interpretations using mtDNA data
An empirical evaluation of four variants of a universal species-area relationship
The Maximum Entropy Theory of Ecology (METE) predicts a universal
species-area relationship (SAR) that can be fully characterized using only the
total abundance (N) and species richness (S) at a single spatial scale. This
theory has shown promise for characterizing scale dependence in the SAR.
However, there are currently four different approaches to applying METE to
predict the SAR and it is unclear which approach should be used due to a lack
of empirical evaluation. Specifically, METE can be applied recursively or a
non-recursively and can use either a theoretical or observed species-abundance
distribution (SAD). We compared the four different combinations of approaches
using empirical data from 16 datasets containing over 1000 species and 300,000
individual trees and herbs. In general, METE accurately downscaled the SAR
(R^2> 0.94), but the recursive approach consistently under-predicted richness,
and METEs accuracy did not depend strongly on using the observed or predicted
SAD. This suggests that best approach to scaling diversity using METE is to use
a combination of non-recursive scaling and the theoretical abundance
distribution, which allows predictions to be made across a broad range of
spatial scales with only knowledge of the species richness and total abundance
at a single scale.Comment: main text: 20 pages, 2 tables, 3 figure
A New Generating Function for Calculating the Igusa Local Zeta Function
A new method is devised for calculating the Igusa local zeta function
of a polynomial over a -adic field. This involves a new
kind of generating function that is the projective limit of a family of
generating functions, and contains more data than . This resides in
an algebra whose structure is naturally compatible with operations on the
underlying polynomials, facilitating calculation of local zeta functions. This
new technique is used to expand significantly the set of quadratic polynomials
whose local zeta functions have been calculated explicitly. Local zeta
functions for arbitrary quadratic polynomials over -adic fields with odd
are presented, as well as for polynomials over unramified -adic fields of
the form where is a quadratic form and is a linear form where
and have disjoint variables. For a quadratic form over an arbitrary
-adic field with odd , this new technique makes clear precisely which of
the three candidate poles are actual poles.Comment: 54 page
Sediment Phosphorus Cycling in a Managed System Irondequoit Bay, N.Y.
The current status of internal phosphorus loading was evaluated in Irondequoit Bay, NY, an embayment of Lake Ontario. Sediment core incubation experiments and phosphorus water column profiles were used to quantify the release rate of phosphorus from the deepwater sediments of Irondequoit Bay during summer periods of low hypolimnetic oxygen. The top 25 cm of sediment cores collected monthly from May 2004 through September 2004 were analyzed for total phosphorus, total manganese, total iron, and total aluminum. Phosphorus fractionation of the sediment cores was determined through sequential extraction. Phosphorus water column data collected during the summer of 2003 and 2004 yielded an average release rate of 8.15 mg P/m2/day. Sediment core incubation experiments yielded an average release rate of 2.89 mg P/m2/day. Predictive models yielded estimates of phosphorus release rates ranging from 0.11 to 31.56 mg P/m2/day. Total phosphorus concentrations in the sediment averaged 1.389 ± 0.150 g P/kg dry wt.
Sequential extraction of phosphorus fractions from the top 25 cm of deep-water sediment revealed that approximately 25% of phosphorus was stored in a redox-sensitive form, most likely sorbed onto iron and manganese oxyhydroxides. Iron and manganese profiles from the water column indicated that manganese from the sediment was cycling with phosphorus into the overlying waters, while iron did not demonstrate evidence of cycling. Iron was kept out of solution by low concentrations of oxygen that had been maintained in the hypolimnion through a summer oxygen supplementation program on Irondequoit Bay
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A Comparison of Interpolation Methods for Sparse Data: Application to Wind and Concentration Fields
In order to produce gridded fields of pollutant concentration data and surface wind data for use in an air quality model, a number of techniques for interpolating sparse data values are compared. The techniques are compared using three data sets. One is an idealized concentration distribution to which the exact solution is known, the second is a potential flow field, while the third consists of surface ozone concentrations measured in the Los Angeles Basin on a particular day. The results of the study indicate that fitting a second-degree polynomial to each subregion (triangle) in the plane with each data point weighted according to its distance from the subregion provides a good compromise between accuracy and computational cost
Preference Conundrums
Every law teacher and many law students and practitioners understand the intellectual sport to be found in Section 547 on preference law. Because the preference rules are so intricate, rigorously logical-but really not logical-they command more than their fair attention, not only in law school but also in continuing legal education and even in the courts. Our purpose in this article is not to answer any of the difficult questions or to give a global explanation of preference law. Rather it is to confront a few of the conundrums in Section 547 and to follow the paths of those conundrums a little farther into the bush than have others. We concentrate on four preference problems. The first is the application of 547(c)(5), the exception for after-acquired property. Second, we examine the vitality of the old arguments that were used where 547(c)(5) is now used. Surprisingly some parts of those have survived the enactment of the 1978 Code. Next we deal with the question when is the hypothetical date of liquidation under (b)(5) and we conclude with a first cousin of the Deprizio issue-the issues arising when a payment to one creditor arguably causes a preference to another. Those interested in answers should not look here. This is for those interested in playing in the complexities of preference law
The Economics of Efficient Phosphorus Abatement in a Watershed
This study presents a method to determine efficient environmental targets at a watershed level. Efficient targets are devised by estimating abatement cost and cost of environmental damages and minimizing their sum. The method was applied to a case study of phosphorus pollution in a watershed in Oklahoma. Several cumulative scenarios with alternative abatement options were simulated and efficient targets were determined. As the number of abatement options at disposal to agricultural sources increased, their optimal abatement expanded relative to the abatement at the point source. Efficient targets were found to be dependent on the choice of policy that stimulates abatement.efficiency, environmental targets, phosphorus pollution, watershed, Resource /Energy Economics and Policy,
Economic Analysis of Management Practices to Reduce Phosphorus Load to Lake Eucha and Spavinaw
Changes in management practices are often proposed to reduce phosphorus loading from a watershed due to over application of poultry litter. This study determines the choice, location, and level of each best management practice in the watershed to meet a Total Maximum Daily Load and margins of safety at least cost.best management practice, phosphorus runoff, poultry litter, Target MOTAD, Environmental Economics and Policy,
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