261 research outputs found
Multiple sclerosis or neuromyelitis optica? Re-evaluating an 18th-century illness using 21st-century software
In this paper we report the application of an extensive database of symptoms, signs, laboratory findings and illnesses, to the diagnosis of an historical figure. The medical diagnosis of Augustus d'Este (1794ā1848) ā widely held to be the first documented case of multiple sclerosis ā is reviewed, using the detailed symptom diary, which he kept over many years, as clinical data. Some of the reported features prompted the competing claim that d'Este suffered from acute porphyria, which in turn was used in support of the hypothesis that his grandfather, King George III, also suffered from the disease. We find that multiple sclerosis is statistically the most likely diagnosis, with neuromyelitis optica a strong alternative possibility. The database did not support a diagnosis of any of the acute porphyrias
Carbon stars at high Galactic latitude
Photometry and kinematics are presented for a sample of objective prism selected carbon stars towards the north and south Galactic poles. Distances are determined by fitting the infrared colors to a giant branch. If these stars are like the carbon stars seen in dwarf spheroidal galaxies, the median distance of the sample is 28 kpc. If they are more like the carbon stars found recently in the Galactic bulge, they may be only half as distant. The surface density of carbon stars as a function of distance is remarkably consistent with an R^(1/4) density profile for the Galactic halo. This density profile can be traced to ā 15 scale radii and fills a volume similar to that occupied by globular clusters. The data yield an effective
radius of either 7.0 or 3.5 kpc depending on choice of distance scale. The velocity dispersion of the sample is 96 + 12 km/s. A kinematic model in which vertical velocity dispersion is independent of height above the Galactic plane seems in best accord with the data
Species and Genotype Effects of Bioenergy Crops on Root Production, Carbon and Nitrogen in Temperate Agricultural Soil
Bioenergy crops have a secondary benefit if they increase soil organic C (SOC) stocks through capture and allocation below-ground. The effects of four genotypes of short-rotation coppice willow (Salix spp., āTerra Novaā and āToraā) and Miscanthus (M. Ć giganteus (āGiganteusā) and M. sinensis (āSinensisā)) on roots, SOC and total nitrogen (TN) were quantified to test whether below-ground biomass controls SOC and TN dynamics. Soil cores were collected under (āplantā) and between plants (āgapā) in a field experiment on a temperate agricultural silty clay loam after 4- and 6-yearsā management. Root density was greater under Miscanthus for plant (up to 15.5 kg mā3) compared with gap (up to 2.7 kg mā3) whereas willow had lower densities (up to 3.7 kg mā3). Over two years, SOC increased below 0.2 m depth from 7.1 to 8.5 kg mā3 and was greatest under Sinensis at 0-0.1 m depth (24.8 kg mā3). Miscanthus-derived SOC, based on stable isotope analysis, was greater under plant (11.6 kg mā3) than gap (3.1 kg mā3) for Sinensis. Estimated SOC stock change rates over the two-year period to 1-m depth were 6.4 for Terra Nova, 7.4 for Tora, 3.1 for Giganteus and 8.8 Mg haā1 yearā1 for Sinensis. Rates of change of TN were much less. That SOC matched root mass down the profile, particularly under Miscanthus, indicated that perennial root systems are an important contributor. Willow and Miscanthus offer both biomass production and C sequestration when planted in arable soil
CpG Islands: Starting Blocks for Replication and Transcription
International audienc
Genetic improvement of willow for bioenergy and biofuels
Willows (Salix spp.) are a very diverse group of catkinābearing trees and shrubs that are widely distributed across temperate regions of the globe. Some species respond well to being grown in short rotation coppice (SRC) cycles, which are much shorter than conventional forestry. Coppicing reinvigorates growth and the biomass rapidly accumulated can be used as a source of renewable carbon for bioenergy and biofuels. As SRC willows reādistribute nutrients during the perennial cycle they require only minimal nitrogen fertilizer for growth. This results in fuel chains with potentially high greenhouse gas reductions. To exploit their potential for renewable energy, willows need to be kept free of pests and diseases and yields need to be improved without significantly increasing the requirements for fertilizers and water. The biomass composition needs to be optimized for different endāuses. Yields also need to be sustainable on land less productive for food crops to reduce conflicts over land use. Advances in understanding the physiology and growth of willow, and in the identification of genes underlying key traits, are now at the stage where they can start to be used in breeding programs to help achieve these goals
Carbon stars at high Galactic latitude
Photometry and kinematics are presented for a sample of objective prism selected carbon stars towards the north and south Galactic poles. Distances are determined by fitting the infrared colors to a giant branch. If these stars are like the carbon stars seen in dwarf spheroidal galaxies, the median distance of the sample is 28 kpc. If they are more like the carbon stars found recently in the Galactic bulge, they may be only half as distant. The surface density of carbon stars as a function of distance is remarkably consistent with an R^(1/4) density profile for the Galactic halo. This density profile can be traced to ā 15 scale radii and fills a volume similar to that occupied by globular clusters. The data yield an effective
radius of either 7.0 or 3.5 kpc depending on choice of distance scale. The velocity dispersion of the sample is 96 + 12 km/s. A kinematic model in which vertical velocity dispersion is independent of height above the Galactic plane seems in best accord with the data
Comprehensive analysis of the chromatin landscape in Drosophila melanogaster.
Chromatin is composed of DNA and a variety of modified histones and non-histone proteins, which have an impact on cell differentiation, gene regulation and other key cellular processes. Here we present a genome-wide chromatin landscape for Drosophila melanogaster based on eighteen histone modifications, summarized by nine prevalent combinatorial patterns. Integrative analysis with other data (non-histone chromatin proteins, DNase I hypersensitivity, GRO-Seq reads produced by engaged polymerase, short/long RNA products) reveals discrete characteristics of chromosomes, genes, regulatory elements and other functional domains. We find that active genes display distinct chromatin signatures that are correlated with disparate gene lengths, exon patterns, regulatory functions and genomic contexts. We also demonstrate a diversity of signatures among Polycomb targets that include a subset with paused polymerase. This systematic profiling and integrative analysis of chromatin signatures provides insights into how genomic elements are regulated, and will serve as a resource for future experimental investigations of genome structure and function
The acute mania of King George III: A computational linguistic analysis.
We used a computational linguistic approach, exploiting machine learning techniques, to examine the letters written by King George III during mentally healthy and apparently mentally ill periods of his life. The aims of the study were: first, to establish the existence of alterations in the King's written language at the onset of his first manic episode; and secondly to identify salient sources of variation contributing to the changes. Effects on language were sought in two control conditions (politically stressful vs. politically tranquil periods and seasonal variation). We found clear differences in the letter corpus, across a range of different features, in association with the onset of mental derangement, which were driven by a combination of linguistic and information theory features that appeared to be specific to the contrast between acute mania and mental stability. The paucity of existing data relevant to changes in written language in the presence of acute mania suggests that lexical, syntactic and stylometric descriptions of written discourse produced by a cohort of patients with a diagnosis of acute mania will be necessary to support the diagnosis independently and to look for other periods of mental illness of the course of the King's life, and in other historically significant figures with similarly large archives of handwritten documents
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