127 research outputs found
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Modelling Rates of Cognitive Decline in Patients with a Dementing Illness
Optima is an Oxford-based longitudinal study of people with dementia, and non-demented elderly. The results of cognitive tests of 123 Optima patients with dementia (age at first visit 44 - 89 years, mean 72.2; 76 females, 47 males; 2 - 2 1 visits, mean 7.9) are analysed. The test used was the cognitive component of the Cambridge Mental Disorders of the Elderly Examination (Camdex). The rate of decline varies markedly between patients; in their first year a few patients show an increased score; the mean decline is 14 Camcog points, and the maximum 61.
The decline of individual patients is modelled by fitting the test scores with the binomial or logistic variant of the general logistic model (as shown in figure 1.1), generally giving a good fit to the data. A method of centering the individual curves about the midpoint of the cognitive scale is developed, which puts patients on a common time-scale and allows all the data to be incorporated into a single fixed-effects model. This method has the power to look at many possible covariates and identify those which apparently have significant effects.
A random-effects model is then adopted (theoretically more plausible) to carry out a more rigorous analysis which confirms these results. Both models show the rate of decline is strongly affected by:
• Age at Camcog midpoint
• Initial homocysteine level
• APOE genotype
• Anti-cholinesterase drugs
In order to show the relative effects of these covariates the idea of the decline ratio, similar to the odds-ratio, is introduced. Its purpose is to quantify the effect of one variable on the progress of the disease, all other things being equal. Younger patients, those with the APOE44 allele and those without the APOE44 allele but with an initially high level of homocysteine, are more likely to have a rapidly progressing illness. Patients who take anticholinesterase drugs in the early stages of their illness are likely to show a slower decline
Passive, non-intrusive assay of depleted uranium
The ability to detect neutrons from the spontaneous fission of 238U in samples of depleted uranium with organic liquid scintillation detectors is presented. In this paper we introduce a small modular organic liquid scintillator detector array that can detect changes in mass of 238U between 3.69 g and 14.46 g. To do this, 18-hour assays of various masses of 0.3%wt. of depleted uranium dioxide were assessed using four EJ-309 detectors, a mixed field analyser operated in pulse gradient analysis mode, and associated counting components. We observe a background-corrected fast neutron count sensitivity of (2.0 ± 0.3) × 10-4 n g-1 s-1 per detector. This research demonstrates a proof of concept for depleted uranium quantity to be assessed passively on a non-intrusive basis via its spontaneous fission decay
Agricultural and empowerment pathways from land ownership to women's nutrition in India.
Land size is an important equity concern for the design of 'nutrition-sensitive' agricultural interventions. We unpack some of the pathways between land and nutrition using a cross-sectional baseline survey data set of 4,480 women from 148 clusters from the 'Upscaling Participatory Action and Videos for Agriculture and Nutrition' trial in Keonjhar district in Odisha, India. Variables used are household ln-land size owned (exposure) and maternal dietary diversity score out of 10 food groups and body mass index (BMI; kg/m2 ) (outcomes); and mediators investigated are production diversity score, value of agricultural production, and indicators for women's empowerment (decision-making in agriculture, group participation, work-free time and land ownership). We assessed mediation using a non-parametric potential outcomes framework method. Land size positively affects maternal dietary diversity scores [β 0.047; 95% confidence interval (CI) (0.011, 0.082)] but not BMI. Production diversity, but not value of production, accounts for 17.6% of total effect mediated. We observe suppression of the effect of land size on BMI, with no evidence of a direct effect for either of the agricultural mediators but indirect effects of β -0.031 [95% CI (-0.048, -0.017)] through production diversity and β -0.047 [95% CI (-0.075, -0.021)] through value of production. An increase in land size positively affects women's decision-making, which in turn negatively affects maternal BMI. The positive effect of work-free time on maternal BMI is suppressed by the negative effect of household land size on work-free time. Agriculture interventions must consider land quality, women's decision-making and implications for women's workload in their design
A common statement on anthropogenic hybridization of the European wildcat (Felis silvestris)
Preserving natural genetic diversity and ecological function of wild species is a central goal in conservation biology. As such, anthropogenic hybridization is considered a threat to wild populations, as it can lead to changes in the genetic makeup of wild species and even to the extinction of wild genomes. In European
wildcats, the genetic and ecological impacts of gene flow from domestic cats are mostly unknown at the species scale. However, in small and isolated populations, it is known to include genetic swamping of wild genomes. In this context, it is crucial to better understand the dynamics of hybridization across the species
range, to inform and implement management measures that maintain the genetic diversity and integrity of the European wildcat. In the present paper, we aim to provide an overview of the current scientific understanding of anthropogenic hybridization in European wildcats, to clarify important aspects regarding the evaluation of hybridization given the available methodologies, and to propose guidelines for management and research priorities.publishedVersio
Earth Science Markup Language: A Solution for Generic Access to Heterogeneous Data Sets
The Earth Science community is processing and analyzing a large amount and variety of data. These data are generally stored in different data formats, which forces the scientists to spend a significant amount of time in writing specialized, data format specific readers. However, this preprocessing burden can by alleviated by using the Earth Science Markup Language (ESML). ESML is a specialized markup language for Earth Science metadata. Based on the eXtensible Markup Language (XMLTM), ESML allows data descriptions to be written in a standard fashion
Earth Science Markup Language: A Solution for Generic Access to Heterogeneous Data Sets
The Earth Science community is processing and analyzing a large amount and variety of data. These data are generally stored in different data formats, which forces the scientists to spend a significant amount of time in writing specialized, data format specific readers. However, this preprocessing burden can by alleviated by using the Earth Science Markup Language (ESML). ESML is a specialized markup language for Earth Science metadata. Based on the eXtensible Markup Language (XMLTM), ESML allows data descriptions to be written in a standard fashion
Age estimation [editorial].
yesAssessing and interpreting dental and skeletal age-related changes in both the living and the dead is of interest to a wide range of disciplines (e.g. see Bittles and Collins 1986) including human biology, paediatrics, public health, palaeodemography, archaeology, palaeontology, human evolution, forensic anthropology and legal medicine. ... This special issue of Annals of Human Biology arises from the 55th annual symposium of the Society for the Study of Human Biology in association with the British Association for Biological Anthropological and Osteoarchaeology held in Oxford, UK, from 9–11 December 2014. Only a selection of the presentations are included here which encompass some of the major recent advances in age estimation from the dentition and skeleton
EARTH SCIENCE MARKUP LANGUAGE
The Earth Science community is the processing and analyzing large amount and variety of data from space and ground-based observations and from models. These data are generally stored in physical media with different data formats. This large variety of data formats forces the scientists to spend significant amount of time in writing specialized data format specific, readers before their analysis can even begin. Formats for Earth Science data can be as simple as ASCII and binary formats or be as complex as Hierarchical Data Format (HDF) and HDF Earth Observing System (HDF-EOS) formats. In this paper, we introduce the Earth Science Markup Language (ESML), being currently developed at the Information Technology and Systems Center at the University of Alabama in Huntsville. ESML would make applications independent of data formats and facilitate easier searches for data via internet search engine. Primary purpose of this paper is to bring ESML to the attention of data consumers and producers, and invite comments and suggestions
EARTH SCIENCE MARKUP LANGUAGE
The Earth Science community is the processing and analyzing large amount and variety of data from space and ground-based observations and from models. These data are generally stored in physical media with different data formats. This large variety of data formats forces the scientists to spend significant amount of time in writing specialized data format specific, readers before their analysis can even begin. Formats for Earth Science data can be as simple as ASCII and binary formats or be as complex as Hierarchical Data Format (HDF) and HDF Earth Observing System (HDF-EOS) formats. In this paper, we introduce the Earth Science Markup Language (ESML), being currently developed at the Information Technology and Systems Center at the University of Alabama in Huntsville. ESML would make applications independent of data formats and facilitate easier searches for data via internet search engine. Primary purpose of this paper is to bring ESML to the attention of data consumers and producers, and invite comments and suggestions
Mechanisms controlling anaemia in Trypanosoma congolense infected mice.
Trypanosoma congolense are extracellular protozoan parasites of the blood stream of artiodactyls and are one of the main constraints on cattle production in Africa. In cattle, anaemia is the key feature of disease and persists after parasitaemia has declined to low or undetectable levels, but treatment to clear the parasites usually resolves the anaemia. The progress of anaemia after Trypanosoma congolense infection was followed in three mouse strains. Anaemia developed rapidly in all three strains until the peak of the first wave of parasitaemia. This was followed by a second phase, characterized by slower progress to severe anaemia in C57BL/6, by slow recovery in surviving A/J and a rapid recovery in BALB/c. There was no association between parasitaemia and severity of anaemia. Furthermore, functional T lymphocytes are not required for the induction of anaemia, since suppression of T cell activity with Cyclosporin A had neither an effect on the course of infection nor on anaemia. Expression of genes involved in erythropoiesis and iron metabolism was followed in spleen, liver and kidney tissues in the three strains of mice using microarrays. There was no evidence for a response to erythropoietin, consistent with anaemia of chronic disease, which is erythropoietin insensitive. However, the expression of transcription factors and genes involved in erythropoiesis and haemolysis did correlate with the expression of the inflammatory cytokines Il6 and Ifng. The innate immune response appears to be the major contributor to the inflammation associated with anaemia since suppression of T cells with CsA had no observable effect. Several transcription factors regulating haematopoiesis, Tal1, Gata1, Zfpm1 and Klf1 were expressed at consistently lower levels in C57BL/6 mice suggesting that these mice have a lower haematopoietic capacity and therefore less ability to recover from haemolysis induced anaemia after infection
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