Characterisation of the entomopathogenic nematode Heterorhabditis (Nematoda : Heterorhabditidae) from Ireland and Britain by molecular and cross-breeding techniques, and the occurrence of the genus in these islands

Des examens de sol ont été effectués en Irlande et en Grande-Bretagne pour rechercher les nématodes du genre #Heterorhabditis. Des échantillons des sols prélevés sur des sites sablonneux furent pourvus de larves de #Galleria mellonella comme appâts. Des #Heterorhabditis furent collectés sur 18 sites sur 169 en Irlande, 2 sur 51 dans le nord de l'Ecosse et 9 sur 20 dans le sud du Pays de Galle. Tous les sites positifs sont situés sur le littoral ; aucun #Heterorhabditis n'a été détecté dans les échantillons prélevés dans 40 sites situés à l'intérieur des terres. La totalité des 76 isolats recueillis au cours de ces analyses ont été identifiés comme appartenant au groupe irlandais d'#Heterorhabditis, à l'aide de méthodes de concentration isoélectrique, de restriction de l'ADN et d'hybridation. Aucun #Heterohabditis appartenant au groupe de l'Europe du nord-ouest n'a été recueilli. Cependant, un isolat recueilli par d'autres chercheurs et provenant du sud de l'Angleterre a été identifié comme appartenant à ce groupe. Les membres du groupe irlandais ne se croisent généralement pas avec les membres du groupe de l'Europe du nord-ouest, bien que des juvéniles infestants fertiles aient été produits dans un nombre limité (3/15) de croisements entre ces groupes. (Résumé d'auteur

Dietary intake of first- and third-year female dietetics students at a South African university

Objective: A survey was undertaken to evaluate and compare dietary intakes of first- and third-year female dietetics students. Design: This was a cross-sectional survey. Setting: The University of Pretoria (UP) was the site of the survey. Population: The study encompassed first- (2012–2015) and third- (2012–2017) year female dietetics students (N = 368). Outcome: Dietary intake data from multiple-day weighed food records were analysed on nutrient, food group and meal and snacking pattern levels. Results: Recorded energy intakes of participants (n = 105 first years, n = 166 third years; response rate: 73.6%) were below Estimated Energy Requirements. Across year groups, intakes exceeded and fell below the Acceptable Macronutrient Distribution Range for fat and carbohydrates respectively; however, third years consumed cereals, grains and starchy vegetables more often. Over 50% of first and third years exceeded Estimated Average Requirements of respectively 3 and 6 of 10 tested micronutrients. Third years recorded higher (all p < 0.001) intakes of protein, magnesium, calcium, zinc and vitamin A than first years. Similarly, their Nutrient Adequacy Ratios were higher (all p < 0.001) for magnesium, calcium and vitamins A, B6 and B12. Average Mean Adequacy Ratios were 70% (first years) and 77% (third years). The year groups differed in terms of food group intake. The number of daily eating occasions decreased over weekends for first and third year students, yet intakes of energy (p < 0.05) and fat (p < 0.001) were higher over weekends. Conclusions: Amidst likely under-recording and/or under-eating, UP female dietetics students’ intakes of some micronutrients may be low. Recorded intakes of third years exceeded those of first years. Recorded nutrient intake improved from the first to the third year of the study in dietetics students.https://www.tandfonline.com/journals/ojcn20Human NutritionStatistic

Acute synovitis and intra-articular methylprednisolone acetate in ponies

AbstractObjective: To determine how acute synovitis, with and without intra-articular methylprednisolone acetate (MPA), affect synthesis of proteoglycan, total protein, and collagen in articular cartilage and total protein synthesis in synovial membrane.Design: Synovitis was induced in 10 ponies by the injection of 0.5 ng lipopolysaccharide (LPS) into the left radiocarpal and midcarpal joints every 2 days for a total of four treatments. Synovitis was documented by clinical examination and synovial fluid analyses. Two days before euthanasia, MPA (0.1 mg/kg) was injected with the last dose of LPS into both the left and right radiocarpal and midcarpal joints of five of these ponies. Proteoglycan synthesis in articular cartilage explants from these joints was measured by incorporation of sodium [35S]sulfate. The size of the proteoglycan monomers and their aggregation with hyaluronan was assessed by size-exclusion chromatography. Protein synthesis in articular cartilage was measured by incorporation of [3H]proline and collagen synthesis by conversion of [3H]proline into [3H]hydroxyproline. Protein synthesis was measured in synovial membrane explants by incorporation of [35S]methionine.Results: Ponies developed carpal effusion and mild lameness accompanied by increased total nucleated cell count and total solids in synovial fluid in response to the LPS injections. Moderate to severe synovial membrane proliferation and inflammation were observed histopathologically in joints injected with LPS but no consistent light-microscopical changes were observed in the articular cartilage from these joints. Intra-articular MPA alone was associated with decreased proteoglycan synthesis and increased protein and collagen synthesis in the cartilage explants. Total protein synthesis by synovial membrane was also increased by MPA alone. In contrast, no differences in protein or proteoglycan synthesis were observed in explants from the joints with synovitis, with or without intra-articular MPA. Treatment with MPA, LPS, and LPS/MPA did not alter proteoglycan aggregate size, but LPS-induced synovitis resulted in an increase in the second largest population of monomers. MPA increased the synthesis of small proteoglycan monomers.Conclusion: Based on the methods used, acute synovitis prevented changes induced by intra-articular MPA alone. Results suggested that the effect of intra-articular MPA on joint metabolism was different between inflamed and normal joints. Experimental studies must consider the effect of inflammation, as well as the potential to introducein vitroculture artifacts when investigating the effect of intra-articular corticosteroids on chondrocyte function

G(2) quivers

We present, in explicit matrix representation and a modernity befitting the community, the classification of the finite discrete subgroups of G2 and compute the McKay quivers arising therefrom. Of physical interest are the classes of Script N = 1 gauge theories descending from M-theory and of mathematical interest are possible steps toward a systematic study of crepant resolutions to smooth G2 manifolds as well as generalised McKay Correspondences. This writing is a companion monograph to hep-th/9811183 and hep-th/9905212, wherein the analogues for Calabi-Yau three- and four-folds were considered

Yukawa couplings in intersecting D-brane models

We compute the Yukawa couplings among chiral fields in toroidal Type II compactifications with wrapping D6-branes intersecting at angles. Those models can yield realistic standard model spectrum living at the intersections. The Yukawa couplings depend both on the Kahler and open string moduli but not on the complex structure. They arise from worldsheet instanton corrections and are found to be given by products of complex Jacobi theta functions with characteristics. The Yukawa couplings for a particular intersecting brane configuration yielding the chiral spectrum of the MSSM are computed as an example. We also show how our methods can be extended to compute Yukawa couplings on certain classes of elliptically fibered CY manifolds which are mirror to complex cones over del Pezzo surfaces. We find that the Yukawa couplings in intersecting D6-brane models have a mathematical interpretation in the context of homological mirror symmetry. In particular, the computation of such Yukawa couplings is related to the construction of Fukaya's category in a generic symplectic manifold.Comment: 47 pages, using JHEP3.cls, 11 figures. Typos and other minor corrections. References adde

A Simple Model for the DNA Denaturation Transition

We study pairs of interacting self-avoiding walks on the 3d simple cubic lattice. They have a common origin and are allowed to overlap only at the same monomer position along the chain. The latter overlaps are indeed favored by an energetic gain. This is inspired by a model introduced long ago by Poland and Sheraga [J. Chem. Phys. {\bf 45}, 1464 (1966)] for the denaturation transition in DNA where, however, self avoidance was not fully taken into account. For both models, there exists a temperature T_m above which the entropic advantage to open up overcomes the energy gained by forming tightly bound two-stranded structures. Numerical simulations of our model indicate that the transition is of first order (the energy density is discontinuous), but the analog of the surface tension vanishes and the scaling laws near the transition point are exactly those of a second order transition with crossover exponent \phi=1. Numerical and exact analytic results show that the transition is second order in modified models where the self-avoidance is partially or completely neglected.Comment: 29 pages, LaTeX, 20 postscript figure

SUSY Quivers, Intersecting Branes and the Modest Hierarchy Problem

We present a class of chiral non-supersymmetric D=4 field theories in which quadratic divergences appear only at two loops. They may be depicted as ``SUSY quivers'' in which the nodes represent a gauge group with extended e.g., N=4 SUSY whereas links represent bifundamental matter fields which transform as chiral multiplets with respect to different N=1 subgroups. One can obtain this type of field theories from simple D6-brane configurations on Type IIA string theory compactified on a six-torus. We discuss the conditions under which this kind of structure is obtained from D6-brane intersections. We also discuss some aspects of the effective low-energy field theory. In particular we compute gauge couplings and Fayet-Iliopoulos terms from the Born-Infeld action and show how they match the field theory results. This class of theories may be of phenomenological interest in order to understand the modest hierarchy problem i.e., the stability of the hierarchy between the weak scale and a fundamental scale of order 10-100 TeV which appears e.g. in low string scale models. Specific D-brane models with the spectrum of the SUSY Standard Model and three generations are presented.Comment: 36 pages, using JHEP3.cls, 8 figures. References update

D-Brane Probes of Special Holonomy Manifolds

Using D2-brane probes, we study various properties of M-theory on singular, non-compact manifolds of G_2 and Spin(7) holonomy. We derive mirror pairs of N=1 supersymmetric three-dimensional gauge theories, and apply this technique to realize exceptional holonomy manifolds as both Coulomb and Higgs branches of the D2-brane world-volume theory. We derive a ``G_2 quotient construction'' of non-compact manifolds which admit a metric of G_2 holonomy. We further discuss the moduli space of such manifolds, including the structure of geometrical transitions in each case. For completeness, we also include familiar examples of manifolds with SU(3) and Sp(2) holonomy, where some of the new ideas are clarified and tested.Comment: 79 pages, Late

Changes in the Frontotemporal Cortex and Cognitive Correlates in First-Episode Psychosis

Background: Loss of cortical volume in frontotemporal regions has been reported in patients with schizophrenia and their relatives. Cortical area and thickness are determined by different genetic processes, and measuring these parameters separately may clarify disturbances in corticogenesis relevant to schizophrenia. Our study also explored clinical and cognitive correlates of these parameters.Methods: Thirty-seven patients with first-episode psychosis (34 schizophrenia, 3 schizoaffective disorder) and 38 healthy control subjects matched for age and sex took part in the study. Imaging was performed on an magnetic resonance imaging 1.5-T scanner. Area and thickness of the frontotemporal cortex were measured using a surface-based morphometry method (Freesurfer). All subjects underwent neuropsychologic testing that included measures of premorbid and current IQ, working and verbal memory, and executive function.Results: Reductions in cortical area, more marked in the temporal cortex, were present in patients. Overall frontotemporal cortical thickness did not differ between groups, although regional thinning of the right superior temporal region was observed in patients. There was a significant association of both premorbid IQ and IQ at disease onset with area, but not thickness, of the frontotemporal cortex, and working memory span was associated with area of the frontal cortex. These associations remained significant when only patients with schizophrenia were considered.Conclusions: Our results suggest an early disruption of corticogenesis in schizophrenia, although the effect of subsequent environmental factors cannot be excluded. In addition, cortical abnormalities are subject to regional variations and differ from those present in neurodegenerative diseases

Thermodynamics and collapse of self-gravitating Brownian particles in D dimensions

We address the thermodynamics (equilibrium density profiles, phase diagram, instability analysis...) and the collapse of a self-gravitating gas of Brownian particles in D dimensions, in both canonical and microcanonical ensembles. In the canonical ensemble, we derive the analytic form of the density scaling profile which decays as f(x)=x^{-\alpha}, with alpha=2. In the microcanonical ensemble, we show that f decays as f(x)=x^{-\alpha_{max}}, where \alpha_{max} is a non-trivial exponent. We derive exact expansions for alpha_{max} and f in the limit of large D. Finally, we solve the problem in D=2, which displays rather rich and peculiar features