1,347 research outputs found

    A microfluidic chip based model for the study of full thickness human intestinal tissue using dual flow

    Get PDF
    © 2016 Author(s). The study of inflammatory bowel disease, including Ulcerative Colitis and Crohn's Disease, has relied largely upon the use of animal or cell culture models; neither of which can represent all aspects of the human pathophysiology. Presented herein is a dual flow microfluidic device which holds full thickness human intestinal tissue in a known orientation. The luminal and serosal sides are independently perfused ex vivo with nutrients with simultaneous waste removal for up to 72 h. The microfluidic device maintains the viability and integrity of the tissue as demonstrated through Haematoxylin & Eosin staining, immunohistochemistry and release of lactate dehydrogenase. In addition, the inflammatory state remains in the tissue after perfusion on the device as determined by measuring calprotectin levels. It is anticipated that this human model will be extremely useful for studying the biology and tes ting novel interventions in diseased tissue

    Anomalous Radio-Wave Scattering from Interstellar Plasma Structures

    Full text link
    This paper considers scattering screens that have arbitrary spatial variations of scattering strength transverse to the line of sight, including screens that are spatially well confined, such as disks and filaments. We calculate the scattered image of a point source and the observed pulse shape of a scattered impulse. The consequences of screen confinement include: (1) Source image shapes that are determined by the physical extent of the screen rather than by the shapes of much-smaller diffracting microirregularities. These include image elongations and orientations that are frequency dependent. (2) Variation with frequency of angular broadening that is much weaker than the trademark \nu^{-2} scaling law (for a cold, unmagnetized plasma), including frequency-independent cases; and (3) Similar departure of the pulse broadening time from the usually expected \nu^{-4} scaling law. We briefly discuss applications that include scattering of pulses from the Crab pulsar by filaments in the Crab Nebula; image asymmetries from Galactic scattering of the sources Cyg X-3, Sgr A*, and NGC 6334B; and scattering of background active galactic nuclei by intervening galaxies. We also address the consequences for inferences about the shape of the wavenumber spectrum of electron density irregularities, which depend on scaling laws for the image size and the pulse broadening. Future low-frequency (< 100 MHz) array observations will also be strongly affected by the Galactic structure of scattering material. Our formalism is derived in the context of radio scattering by plasma density fluctuations. It is also applicable to optical, UV and X-ray scattering by grains in the interstellar medium.Comment: 21 pages, LaTeX2e with AASTeX-4.0, 6 PostScript figures, accepted by ApJ, revised version has minor changes to respond to referee comments and suggestion

    The Glassy Wormlike Chain

    Full text link
    We introduce a new model for the dynamics of a wormlike chain in an environment that gives rise to a rough free energy landscape, which we baptise the glassy wormlike chain. It is obtained from the common wormlike chain by an exponential stretching of the relaxation spectrum of its long-wavelength eigenmodes, controlled by a single stretching parameter. Predictions for pertinent observables such as the dynamic structure factor and the microrheological susceptibility exhibit the characteristics of soft glassy rheology and compare favourably with experimental data for reconstituted cytoskeletal networks and live cells. We speculate about the possible microscopic origin of the stretching, implications for the nonlinear rheology, and the potential physiological significance of our results.Comment: 12 pages, 8 figures. Minor correction

    Multidimensional links in biodiversity research: an integrated exercise

    Get PDF
    The advent of viable techniques for phylogenetic estimates together with evidences on their relationships on the basis of molecular biology have kindled an increased interest in systematic and biodiversity studies. The coming together of systematists, ecologists, developmental and molecular biologists as well as the biotechnologists would give an impetus to the study of biodiversity. Thus, the integration of basic and applied sciences will result in an effective understanding of the dynamics of biodiversity and help in overcoming the deterioration of the biological systems as well as the diverse environmental problems plaguing society

    Two new genera and species of Tubuliferan thrips (Thysanoptera: Insecta) from India

    Get PDF
    The new genera and species Araeothrips longisetis and Salothrips indicus are discussed in this paper

    Solar Polar Fields During Cycles 21 --- 23: Correlation with Meridional Flows

    Full text link
    We have examined polar magnetic fields for the last three solar cycles, {viz.\it{viz.}}, cycles 21, 22 and 23 using NSO Kitt Peak synoptic magnetograms. In addition, we have used SoHO/MDI magnetograms to derive the polar fields during cycle 23. Both Kitt Peak and MDI data at high latitudes (78{^{\circ}}--90{^{\circ}}) in both solar hemispheres show a significant drop in the absolute value of polar fields from the late declining phase of the solar cycle 22 to the maximum of the solar cycle 23. We find that long term changes in the absolute value of the polar field, in cycle 23, is well correlated with changes in meridional flow speeds that have been reported recently. We discuss the implication of this in influencing the extremely prolonged minimum experienced at the start of the current cycle 24 and in forecasting the behaviour of future solar cycles.Comment: 4 Figures 11 pages; Revised version under review in Solar Physic

    Thrips-fimgus association with special reference to the sporophagous Bactrothrips idolomorphus (Karny). (Tubulifera: Thysanoptera)

    Get PDF
    Aspects of feeding and fungal spore preference in terms of the percentage of gut-spore composition, and the relative preference of sporophagous Tubulifera to Coelomycetes, Ascomycetes, Hyphomycetes are highlighted. A positive correlation between the width of the maxillary stylets and the fungal spore size indicates the relationship between the two in the choice of the spore type for feeding. The incidence of reproductive polymorphism among the majority of large spore feeding thrips and their absence in hyaline spore feeders, the role of abiotic factors such as temperature and relative humidity in determining the type of reproduction and their influence on the post-embryonic development inBactrothrips idolomorphus are discussed. Numerical variation in the pre-vitellogenic, vitellogenic and developing oocytes during oviparity, ovoviviparity and viviparity is also discussed

    Thromboprophylaxis Is Associated With Reduced Post-hospitalization Venous Thromboembolic Events in Patients With Inflammatory Bowel Diseases

    Get PDF
    Background & Aims Patients with inflammatory bowel diseases (IBDs) have increased risk for venous thromboembolism (VTE); those who require hospitalization have particularly high risk. Few hospitalized patients with IBD receive thromboprophylaxis. We analyzed the frequency of VTE after IBD-related hospitalization, risk factors for post-hospitalization VTE, and the efficacy of prophylaxis in preventing post-hospitalization VTE. Methods In a retrospective study, we analyzed data from a multi-institutional cohort of patients with Crohn's disease or ulcerative colitis and at least 1 IBD-related hospitalization. Our primary outcome was a VTE event. All patients contributed person-time from the date of the index hospitalization to development of VTE, subsequent hospitalization, or end of follow-up. Our main predictor variable was pharmacologic thromboprophylaxis. Cox proportional hazard models adjusting for potential confounders were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results From a cohort of 2788 patients with at least 1 IBD-related hospitalization, 62 patients developed VTE after discharge (2%). Incidences of VTE at 30, 60, 90, and 180 days after the index hospitalization were 3.7/1000, 4.1/1000, 5.4/1000, and 9.4/1000 person-days, respectively. Pharmacologic thromboprophylaxis during the index hospital stay was associated with a significantly lower risk of post-hospitalization VTE (HR, 0.46; 95% CI, 0.22–0.97). Increased numbers of comorbidities (HR, 1.30; 95% CI, 1.16–1.47) and need for corticosteroids before hospitalization (HR, 1.71; 95% CI, 1.02–2.87) were also independently associated with risk of VTE. Length of hospitalization or surgery during index hospitalization was not associated with post-hospitalization VTE. Conclusions Pharmacologic thromboprophylaxis during IBD-related hospitalization is associated with reduced risk of post-hospitalization VTE.National Institutes of Health (U.S.) (U54-LM008748

    On the developmental morphology of the rosette galls of Acacia leucophloea Willd., (Mimosaceae) induced by Thilakothrips hablu Ramk. (Thysanoptera: Insecta)

    Get PDF
    Thilakothrips babuli induces rosette (artichoke) galls on the axillary buds of Acacia leucophloea. As a result of feeding by the building populations of thrips, axillary shoot meristems are destroyed, and primordial palisade tissues of the leaflets and cortical tissues of the shoot axis are transformed into nutritive cells of specialised morphology. Very similar to the galls induced by mites, midges, chalcids, and chloropids, Thilakothrips-induced Acacia galls also have a characteristic morphology, involving the inhibition of elongation of the shoot axis and crowding of maldeveloped leaflets. While describing the cecidogenesis in relation to the biology of the gall maker, an attempt has been made to discuss the morphological convergence among shoot apex galls
    corecore