629 research outputs found

    Leptonic contribution to the bulk viscosity of nuclear matter

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    For beta-equilibrated nuclear matter we estimate the contribution to the bulk viscosity from purely leptonic processes, namely the conversion of electrons to and from muons. For oscillation frequencies in the kiloHertz range, we find that this process provides the dominant contribution to the bulk viscosity when the temperature is well below the critical temperature for superconductivity or superfluidity of the nuclear matter.Comment: 15 pages, LaTeX, new appendix and general clarifications in response to referee comment

    Cripto promotes A–P axis specification independently of its stimulatory effect on Nodal autoinduction

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    The EGF-CFC gene cripto governs anterior–posterior (A–P) axis specification in the vertebrate embryo. Existing models suggest that Cripto facilitates binding of Nodal to an ActRII–activin-like kinase (ALK) 4 receptor complex. Cripto also has a crucial function in cellular transformation that is independent of Nodal and ALK4. However, how ALK4-independent Cripto pathways function in vivo has remained unclear. We have generated cripto mutants carrying the amino acid substitution F78A, which blocks the Nodal–ALK4–Smad2 signaling both in embryonic stem cells and cell-based assays. In criptoF78A/F78A mouse embryos, Nodal fails to expand its own expression domain and that of cripto, indicating that F78 is essential in vivo to stimulate Smad-dependent Nodal autoinduction. In sharp contrast to cripto-null mutants, criptoF78A/F78A embryos establish an A–P axis and initiate gastrulation movements. Our findings provide in vivo evidence that Cripto is required in the Nodal–Smad2 pathway to activate an autoinductive feedback loop, whereas it can promote A–P axis formation and initiate gastrulation movements independently of its stimulatory effect on the canonical Nodal–ALK4–Smad2 signaling pathway

    Tests of the Equivalence Principle with Neutral Kaons

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    We test the Principle of Equivalence for particles and antiparticles, using CPLEAR data on tagged K0 and K0bar decays into pi^+ pi^-. For the first time, we search for possible annual, monthly and diurnal modulations of the observables |eta_{+-}| and phi_{+-}, that could be correlated with variations in astrophysical potentials. Within the accuracy of CPLEAR, the measured values of |eta_{+-}| and phi_{+-} are found not to be correlated with changes of the gravitational potential. We analyze data assuming effective scalar, vector and tensor interactions, and we conclude that the Principle of Equivalence between particles and antiparticles holds to a level of 6.5, 4.3 and 1.8 x 10^{-9}, respectively, for scalar, vector and tensor potentials originating from the Sun with a range much greater than the distance Earth-Sun. We also study energy-dependent effects that might arise from vector or tensor interactions. Finally, we compile upper limits on the gravitational coupling difference between K0 and K0bar as a function of the scalar, vector and tensor interaction range.Comment: 15 pages latex 2e, five figures, one style file (cernart.csl) incorporate

    Profiles and outcome of traditional healing practices for severe mental illnesses in two districts of Eastern Uganda

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    Background : The WHO estimates that more than 80% of African populations attend traditional healers for health reasons and that 40%–60% of these have some kind of mental illness. However, little is known about the profiles and outcome of this traditional approach to treatment. Objective : The purpose of this study was to describe the profiles and outcome of traditional healing practices for severe mental illnesses in Jinja and Iganga districts in the Busoga region of Eastern Uganda. Methods : Four studies were conducted. Study I used focus group discussions (FGDs) with case vignettes with local community members and traditional healers to explore the lay concepts of psychosis. Studies II and III concerned a cross-sectional survey of patients above 18 years at the traditional healer's shrines and study IV was made on a prospective cohort of patients diagnosed with psychosis in study III. Manual content analysis was used in study I; quantitative data in studies II, III, and IV were analyzed at univariate, bivariate, and multivariate levels to determine the association between psychological distress and socio-demographic factors; for study IV, factors associated with outcome were analyzed. One-way ANOVA for independent samples was the analysis used in Study IV. Results : The community gave indigenous names to psychoses (mania, schizophrenia, and psychotic depression) and had multiple explanatory models for them. Thus multiple solutions for these problems were sought. Of the 387 respondents, the prevalence of psychological distress was 65.1%, where 60.2% had diagnosable current mental illness, and 16.3% had had one disorder in their lifetime. Over 80% of patients with psychosis used both biomedical and traditional healing systems. Those who combined these two systems seemed to have a better outcome. All the symptom scales showed a percentage reduction of more than 20% at the 3- and 6-month follow-ups. Conclusion : Traditional healers shoulder a large burden of care of patients with mental health problems. This calls for all those who share the goal of improving the mental health of individuals to engage with traditional healers

    Morphological brain differences between adult stutterers and non-stutterers

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    BACKGROUND: The neurophysiological and neuroanatomical foundations of persistent developmental stuttering (PDS) are still a matter of dispute. A main argument is that stutterers show atypical anatomical asymmetries of speech-relevant brain areas, which possibly affect speech fluency. The major aim of this study was to determine whether adults with PDS have anomalous anatomy in cortical speech-language areas. METHODS: Adults with PDS (n = 10) and controls (n = 10) matched for age, sex, hand preference, and education were studied using high-resolution MRI scans. Using a new variant of the voxel-based morphometry technique (augmented VBM) the brains of stutterers and non-stutterers were compared with respect to white matter (WM) and grey matter (GM) differences. RESULTS: We found increased WM volumes in a right-hemispheric network comprising the superior temporal gyrus (including the planum temporale), the inferior frontal gyrus (including the pars triangularis), the precentral gyrus in the vicinity of the face and mouth representation, and the anterior middle frontal gyrus. In addition, we detected a leftward WM asymmetry in the auditory cortex in non-stutterers, while stutterers showed symmetric WM volumes. CONCLUSIONS: These results provide strong evidence that adults with PDS have anomalous anatomy not only in perisylvian speech and language areas but also in prefrontal and sensorimotor areas. Whether this atypical asymmetry of WM is the cause or the consequence of stuttering is still an unanswered question

    Metastability and Transient Effects in Vortex Matter Near a Decoupling Transition

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    We examine metastable and transient effects both above and below the first-order decoupling line in a 3D simulation of magnetically interacting pancake vortices. We observe pronounced transient and history effects as well as supercooling and superheating between the 3D coupled, ordered and 2D decoupled, disordered phases. In the disordered supercooled state as a function of DC driving, reordering occurs through the formation of growing moving channels of the ordered phase. No channels form in the superheated region; instead the ordered state is homogeneously destroyed. When a sequence of current pulses is applied we observe memory effects. We find a ramp rate dependence of the V(I) curves on both sides of the decoupling transition. The critical current that we obtain depends on how the system is prepared.Comment: 10 pages, 15 postscript figures, version to appear in PR

    PDK-1/AKT pathway as a novel therapeutic target in rhabdomyosarcoma cells using OSU-03012 compound

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    Rhabdomyosarcoma (RMS) is the most common paediatric soft-tissue sarcoma including two major subtypes, alveolar rhabdomyosarcoma (ARMS) and embryonal rhabdomyosarcoma (ERMS). Increasing evidence suggests that oncogenesis of RMS involves multistages of signalling protein dysregulation which may include prolonged activation of serine/threonine kinases such as phosphoinositide-dependant kinase-1 (PDK-1) and AKT. To date, whether PDK-1/AKT pathway is activated in RMS is unknown. This study was to examine phosphorylation status of AKT and to evaluate a novel small molecular inhibitor, OSU-03012 targeting PDK-1 in RMS. We examined phosphorylation levels of AKT using ARMS and ERMS tissue microarray and immunohistochemistry staining. Our results showed phospho-AKTThr308 level is elevated 42 and 35% in ARMS and ERMS, respectively. Phospho-AKTSer473 level is also increased 43% in ARMS and 55% in ERMS. Furthermore, we showed that OSU-03012 inhibits cell viability and induces apoptosis in ARMS and ERMS cell lines (RH30, SMS-CTR), which express elevated phospho-AKT levels. Normal cells are much less sensitive to OSU-03012 and in which no detectable apoptosis was observed. This study showed, for the first time, that PDK-1/AKT pathway is activated in RMS and may play an important role in survival of RMS. PDK-1/AKT pathway may be an attractive therapeutic target for cancer intervention in RMS using OSU-03012

    Homosexual Women Have Less Grey Matter in Perirhinal Cortex than Heterosexual Women

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    Is sexual orientation associated with structural differences in the brain? To address this question, 80 homosexual and heterosexual men and women (16 homosexual men and 15 homosexual women) underwent structural MRI. We used voxel-based morphometry to test for differences in grey matter concentration associated with gender and sexual orientation. Compared with heterosexual women, homosexual women displayed less grey matter bilaterally in the temporo-basal cortex, ventral cerebellum, and left ventral premotor cortex. The relative decrease in grey matter was most prominent in the left perirhinal cortex. The left perirhinal area also showed less grey matter in heterosexual men than in heterosexual women. Thus, in homosexual women, the perirhinal cortex grey matter displayed a more male-like structural pattern. This is in accordance with previous research that revealed signs of sex-atypical prenatal androgenization in homosexual women, but not in homosexual men. The relevance of the perirhinal area for high order multimodal (olfactory and visual) object, social, and sexual processing is discussed

    Polymorphism in sulfadimidine/4- aminosalicylic acid cocrystals: solid-state characterization and physicochemical properties

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    YesPolymorphism of crystalline drugs is a common phenomenon. However, the number of reported polymorphic cocrystals is very limited. In this work, the synthesis and solid state characterisation of a polymorphic cocrystal composed of sulfadimidine (SD) and 4- aminosalicylic acid (4-ASA) is reported for the first time. By liquid-assisted milling, the SD:4-ASA 1:1 form I cocrystal, the structure of which has been previously reported, was formed. By spray drying, a new polymorphic form (form II) of the SD:4-ASA 1:1 cocrystal was discovered which could also be obtained by solvent evaporation from ethanol and acetone. Structure determination of the form II cocrystal was calculated using high resolution X-ray powder diffraction. The solubility of the SD:4-ASA 1:1 cocrystal was dependent on the pH and predicted by a model established for a two amphoteric component cocrystal. The form I cocrystal was found to be thermodynamically more stable in aqueous solution than form II, which showed transformation to form I. Dissolution studies revealed that the dissolution rate of SD from both cocrystals was enhanced when compared to a physical equimolar mixture and pure SD.Science Foundation Ireland (SFI) under Grant Number 07/SRC/B1158 and SFI/12/RC/2275
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