3,106 research outputs found
A voxel based morphometry investigation into brain abnormalities in different subsets of developmental dyslexia
Several previous studies have reported that brain structure in developmental dyslexics differs from that of non-impaired readers. The results, however, have been inconsistent across studies and are not highly significant. The hypothesis driving the present study is that the inconsistent and weak effects are as a consequence of individual variability in how dyslexia manifests. On the basis of a previous unpublished study at the Wellcome Department of Imaging Neuroscience, it has been proposed that adolescents with reading impairments can be subdivided into those who have worse reading than spelling (henceforth referred to as dyslexics) and those that have worse spelling than reading (henceforth referred to as dysgraphics). The aim of the present study was to investigate whether this categorisation was also appropriate for adult university students with a history of reading impairments. The project involved detailed behavioural testing and structural MRI acquisition on 29 adults, 16 of which had previously been diagnosed with reading difficulties. On the basis of their behavioural results, the literacy impaired group was divided into two groups: dyslexics and dysgraphics. As predicted by their diagnosis, both groups had worse spelling and slower reading than the non-impaired readers. In addition, both groups had less grey matter than controls in two left hemisphere regions that have previously been associated with the "phonological loop". Critically, however, the structural MRI data also confirmed a double dissociation between grey matter reductions in the dyslexics and dysgraphics. The dyslexics had less grey matter in the right hemisphere phonological areas and the dysgraphics had less grey matter in the cerebellum. These findings support the hypothesis that abnormal brain structure depends on the type of reading impairment
Probiotic administration in congenital heart disease: a pilot study.
ObjectiveTo investigate the impact of probiotic Bifidobacterium longum ssp. infantis on the fecal microbiota and plasma cytokines in neonates with congenital heart disease.Study designSixteen infants with congenital heart disease were randomly assigned to receive either B. infantis (4.2 Ă 10(9) colony-forming units two times daily) or placebo for 8 weeks. Stool specimens from enrolled infants and from six term infants without heart disease were analyzed for microbial composition. Plasma cytokines were analyzed weekly in the infants with heart disease.ResultsHealthy control infants had increased total bacteria, total Bacteroidetes and total bifidobacteria compared to the infants with heart disease, but there were no significant differences between the placebo and probiotic groups. Plasma interleukin (IL)10, interferon (IFN)Îł and IL1ÎČ levels were transiently higher in the probiotic group.ConclusionCongenital heart disease in infants is associated with dysbiosis. Probiotic B. infantis did not significantly alter the fecal microbiota. Alterations in plasma cytokines were found to be inconsistent
Recommended from our members
Population-level effects of parasitism on a freshwater ecosystem engineer, the unionid mussel Anodonta anatina
Funder: Woolf Fisher TrustAbstract: Parasites can negatively affect hosts at individual, population, and speciesâlevel scales. However, the link between individualâ and populationâlevel impacts is often poorly understood. In particular, the populationâlevel response to parasitism may alter wider ecosystem dynamics if animals with ecosystem engineering capabilities are infected. Here, we examine the effects of parasitism on a freshwater ecosystem engineer, the unionid mussel Anodonta anatina, at two different sites. We study three common parasites: the digenean trematode Rhipidocotyle campanula; the unionicolid mite Unionicola intermedia; and the ectoparasitic invasive zebra mussel Dreissena polymorpha. As well as demonstrating the individualâlevel effects of parasitism on the native host mussel, we construct a simple model to estimate the reduction in populationâlevel reproductive output caused by parasites. We show that both infection prevalence and intensity were populationâspecific, with one site having more than three times as many native mussels infected by trematodes and mites than the other, but more than four times fewer mussels afflicted by invasive zebra mussels. Negative reproductive consequences for individual host mussels were documented as a result of parasitism, with trematodes causing castration at both sites. Mites were also correlated with a reduction in the viability of larval offspring (glochidia) by more than 25%, but only at one site, suggesting some potential impacts of parasitism may be population specific. The populationâlevel model shows that parasitism alone reduces larval output of the two populations by 10% and 13%, respectively. Our study takes the important step of scaling individualâlevel effects of parasitism to populationâlevel processes, and highlights the influence that parasites may have in the population dynamics of unionid mussels. Given the ecosystem engineering capabilities of A. anatina, such effects may have important impacts on the wider biota. Even at relatively low prevalences, the observed effects of parasites on native mussel populations suggests that parasitism must be considered in the conservation of freshwater mussels, one of the world's most globally imperilled faunal groups. Further, understanding how the effects of parasitism on individual hosts scales to the ecosystem level is a crucial and unaddressed question in freshwater biology
Evo-devo of human adolescence: beyond disease models of early puberty
Despite substantial heritability in pubertal development, much variation remains to be explained, leaving room for the influence of environmental factors to adjust its phenotypic trajectory in the service of fitness goals. Utilizing evolutionary development biology (evo-devo), we examine adolescence as an evolutionary life-history stage in its developmental context. We show that the transition from the preceding stage of juvenility entails adaptive plasticity in response to energy resources, other environmental cues, social needs of adolescence and maturation toward youth and adulthood. Using the evolutionary theory of socialization, we show that familial psychosocial stress fosters a fast life history and reproductive strategy rather than early maturation being just a risk factor for aggression and delinquency. Here we explore implications of an evolutionary-developmental-endocrinological-anthropological framework for theory building, while illuminating new directions for research
Population genetic structure in European lobsters: implications for connectivity, diversity and hatchery stocking
Mapping species distributions: A comparison of skilled naturalist and lay citizen science recording
To assess the ability of traditional biological recording schemes and lay citizen science approaches to gather data on species distributions and changes therein, we examined bumblebee records from the UKâs national repository (National Biodiversity Network) and from BeeWatch. The two recording approaches revealed similar relative abundances of bumblebee species but different geographical distributions. For the widespread common carder (Bombus pascuorum), traditional recording scheme data were patchy, both spatially and temporally, reflecting active record centre rather than species distribution. Lay citizen science records displayed more extensive geographic coverage, reflecting human population density, thus offering better opportunities to account for recording effort. For the rapidly spreading tree bumblebee (Bombus hypnorum), both recording approaches revealed similar distributions due to a dedicated mapping project which overcame the patchy nature of naturalist records. We recommend, where possible, complementing skilled naturalist recording with lay citizen science programmes to obtain a nation-wide capability, and stress the need for timely uploading of data to the national repository
Full quantum distribution of contrast in interference experiments between interacting one dimensional Bose liquids
We analyze interference experiments for a pair of independent one dimensional
condensates of interacting bosonic atoms at zero temperature. We show that the
distribution function of fringe amplitudes contains non-trivial information
about non-local correlations within individual condensates and can be
calculated explicitly using methods of conformal field theory. We point out
interesting relations between these distribution functions, the partition
function for a quantum impurity in a one-dimensional Luttinger liquid, and
transfer matrices of conformal field theories. We demonstrate the connection
between interference experiments in cold atoms and a variety of statistical
models ranging from stochastic growth models to two dimensional quantum
gravity. Such connection can be used to design a quantum simulator of unusual
two-dimensional models described by nonunitary conformal field theories with
negative central charges.Comment: 9 pages, 5 figures; Accepted for publication in Nature Physic
Potential Sensitivity of Gamma-Ray Burster Observations to Wave Dispersion in Vacuo
The recent confirmation that at least some gamma-ray bursters (GRBs) are
indeed at cosmological distances raises the possibility that observations of
these could provide interesting constraints on the fundamental laws of physics.
Here we demonstrate that the fine-scale time structure and hard spectra of GRB
emissions are very sensitive to the possible dispersion of electromagnetic
waves in vacuo with velocity differences \delta v \sim E/E_{\QG}, as
suggested in some approaches to quantum gravity. A simple estimate shows that
GRB measurements might be sensitive to a dispersion scale comparable
to the Planck energy scale GeV, sufficient to test some of
these theories, and we outline aspects of an observational programme that could
address this goal.Comment: LaTex. 9 pages. Version accepted for publication in Nature. (A few
changes to the reference list. Additional comments on the analyticity
properties of the dispersion law.
- âŠ