Charmed-Baryon Spectroscopy from Lattice QCD with N_f=2+1+1 Flavors

We present the results of a calculation of the positive-parity ground-state charmed-baryon spectrum using 2+1+1 flavors of dynamical quarks. The calculation uses a relativistic heavy-quark action for the valence charm quark, clover-Wilson fermions for the valence light and strange quarks, and HISQ sea quarks. The spectrum is calculated with a lightest pion mass around 220 MeV, and three lattice spacings (a \approx 0.12 fm, 0.09 fm, and 0.06 fm) are used to extrapolate to the continuum. The light-quark mass extrapolation is performed using heavy-hadron chiral perturbation theory up to O(m_pi^3) and at next-to-leading order in the heavy-quark mass. For the well-measured charmed baryons, our results show consistency with the experimental values. For the controversial J=1/2 Xi_{cc}, we obtain the isospin-averaged value M_{Xi_{cc}}=3595(39)(20)(6) MeV (the three uncertainties are statistics, fitting-window systematic, and systematics from other lattice artifacts, such as lattice scale setting and pion-mass determination), which shows a 1.7 sigma deviation from the experimental value. We predict the yet-to-be-discovered doubly and triply charmed baryons Xi_{cc}^*, Omega_{cc}, Omega_{cc}^* and Omega_{ccc} to have masses 3648(42)(18)(7) MeV, 3679(40)(17)(5) MeV, 3765(43)(17)(5) MeV and 4761(52)(21)(6) MeV, respectively.Comment: 23 pages, 14 figure

ANTI -ARTHRITIC POTENTIAL OF HELIANTHUS ANNUUS IN LABORATORY ANIMALS

Objective: The present study was carried out to investigate the anti-arthritic potential of ethanolic extract of Helianthus annuus leaves (HA).Methods: The effect of HA was evaluated for chronic inflammation by complete Freud's adjuvant (CFA) induced arthritis in rats.Results: The paw edema was measured along with biochemical, hematological, histopathological, radiographic parameters, and ulcerogenic potential.In this study, pre-treatment with HA significantly decreased paw volume, arthritic index, spleen and thymus weight, ulcerogenic index; and inhibitedhistopathological changes in joint cavity and inhibited destruction of the knee joints induced by CFA in radiographic examination. Treatment ofHA also restored significantly the hematological parameters such as hemoglobin level, total red blood cell, total white blood cell, and erythrocytsedimentation rate along with antioxidant parameters such as superoxide dismutase, catalase glutathione, and lipid peroxide. The serum marker ofarthritis such as C-reactive protein (CRP) and rheumatoid factor were also reduced in the HA-treated arthritic rats.Conclusion: The results of the present study demonstrate the anti-arthritic potential of HA leaves in the anti-arthritic activity.Keywords: Anti-arthritic, C-reactive protein, Complete Freud's adjuvant, Helianthus annuus, Paw volume, Rheumatoid factor

Current Algebra and Conformal Field Theory on a Figure Eight

We examine the dynamics of a free massless scalar field on a figure eight network. Upon requiring the scalar field to have a well defined value at the junction of the network, it is seen that the conserved currents of the theory satisfy Kirchhoff's law, that is that the current flowing into the junction equals the current flowing out. We obtain the corresponding current algebra and show that, unlike on a circle, the left- and right-moving currents on the figure eight do not in general commute in quantum theory. Since a free scalar field theory on a one dimensional spatial manifold exhibits conformal symmetry, it is natural to ask whether an analogous symmetry can be defined for the figure eight. We find that, unlike in the case of a manifold, the action plus boundary conditions for the network are not invariant under separate conformal transformations associated with left- and right-movers. Instead, the system is, at best, invariant under only a single set of transformations. Its conserved current is also found to satisfy Kirchhoff's law at the junction. We obtain the associated conserved charges, and show that they generate a Virasoro algebra. Its conformal anomaly (central charge) is computed for special values of the parameters characterizing the network.Comment: 39 pages; Latex with 1 figure included in encapsulated postscript format. psbox.tex require

10,21-Dimethyl-2,7,13,18-tetraphenyl-3,6,14,17-tetraazatricyclo[17.3.1.18,12]tetracosa-1(23),2,6,8(24),9,11,13,17,19,21-decaene-23,24-diol cyclohexane 0.33-solvate

The title compound, C46H40N4O2·0.33C6H12, was obtained unintentionally as a product of an attempted synthesis of a cadmium(II) complex of the [2,6-{PhSe(CH2)2N=CPh}2C6H2(4-Me)(OH)] ligand. The full tetra­imino­diphenol macrocyclic ligand is generated by the application of an inversion centre. The macrocyclic ligand features strong intra­molecular O—H⋯N hydrogen bonds. The dihedral angles formed between the phenyl ring incorporated within the macrocycle and the peripheral phenyl rings are 82.99 (8) and 88.20 (8)°. The cyclo­hexane solvent mol­ecule lies about a site of symmetry. Other solvent within the lattice was disordered and was treated with the SQUEEZE routine [Spek (2009). Acta Cryst. D65, 148–155]

On Budget-Feasible Mechanism Design for Symmetric Submodular Objectives

We study a class of procurement auctions with a budget constraint, where an auctioneer is interested in buying resources or services from a set of agents. Ideally, the auctioneer would like to select a subset of the resources so as to maximize his valuation function, without exceeding a given budget. As the resources are owned by strategic agents however, our overall goal is to design mechanisms that are truthful, budget-feasible, and obtain a good approximation to the optimal value. Budget-feasibility creates additional challenges, making several approaches inapplicable in this setting. Previous results on budget-feasible mechanisms have considered mostly monotone valuation functions. In this work, we mainly focus on symmetric submodular valuations, a prominent class of non-monotone submodular functions that includes cut functions. We begin first with a purely algorithmic result, obtaining a $\frac{2e}{e-1}$-approximation for maximizing symmetric submodular functions under a budget constraint. We view this as a standalone result of independent interest, as it is the best known factor achieved by a deterministic algorithm. We then proceed to propose truthful, budget feasible mechanisms (both deterministic and randomized), paying particular attention on the Budgeted Max Cut problem. Our results significantly improve the known approximation ratios for these objectives, while establishing polynomial running time for cases where only exponential mechanisms were known. At the heart of our approach lies an appropriate combination of local search algorithms with results for monotone submodular valuations, applied to the derived local optima.Comment: A conference version appears in WINE 201

IL-1RI (interleukin-1 receptor type I) signalling is essential for host defence and hemichannel activity during acute central nervous system bacterial infection

Staphylococcus aureus is a common aetiological agent of bacterial brain abscesses. We have previously established that a considerable IL-1 (interleukin-1) response is elicited immediately following S. aureus infection, where the cytokine can exert pleiotropic effects on glial activation and blood–brain barrier permeability. To assess the combined actions of IL-1α and IL-1β during CNS (central nervous system) infection, host defence responses were evaluated in IL-1RI (IL-1 receptor type I) KO (knockout) animals. IL-1RI KO mice were exquisitely sensitive to intracerebral S. aureus infection, as demonstrated by enhanced mortality rates and bacterial burdens within the first 24 h following pathogen exposure compared with WT (wild-type) animals. Loss of IL-1RI signalling also dampened the expression of select cytokines and chemokines, concomitant with significant reductions in neutrophil and macrophage infiltrates into the brain. In addition, the opening of astrocyte hemichannels during acute infection was shown to be dependent on IL-1RI activity. Collectively, these results demonstrate that IL-1RI signalling plays a pivotal role in the genesis of immune responses during the acute stage of brain abscess development through S. aureus containment, inflammatory mediator production, peripheral immune cell recruitment, and regulation of astrocyte hemichannel activity. Taken in the context of previous studies with MyD88 (myeloid differentiation primary response gene 88) and TLR2 (Toll-like receptor 2) KO animals, the current report advances our understanding of MyD88-dependent cascades and implicates IL-1RI signalling as a major antimicrobial effector pathway during acute brain-abscess formation

Depression, sleeping pattern, and suicidal ideation among medical students in Bangladesh: a cross-sectional pilot study

© 2020, Springer-Verlag GmbH Germany, part of Springer Nature. Background: Depression is a major morbidity and the most common mental disorder among the medical students in medical schools globally. Undergraduate students suffer stress more due to their academic curriculum than the students of other faculties. In low-resource settings like Bangladesh, there is a dearth in research on the mental health of undergraduate medical students. This pilot study was conducted to add to the existing limited evidence by reporting the prevalence of depression and describing sleeping pattern and suicidal tendencies among medical students. Relevantly, we have investigated the overall mental health status among the medical students in Bangladesh. Methods: This cross-sectional study was conducted in two medical colleges of Dhaka between July 2013 and December 2013, among 221 Bangladeshi medical students from first to fifth year. By the convenience sampling technique, data were collected by a pretested, structured, self-administered questionnaire and analysis was done by SPSS version 18.0. Depression was assessed by the validated Patient Health Questionnaire-9 (PHQ-9) tool among the respondents. Goldberg’s General Health Questionnaire (GHQ-28) was used for assessing overall mental health status. Results: Depression was found in 38.9% of participants, with 3.6%, 14.5%, and 20.8% being severe, moderate, and mild depression, respectively. 17.6% of medical students had suicidal tendency or attempted suicide at least once after attending medical school. The sleeping hours were inadequate and altered after starting this stressful academic course. 33.5% of medical students had poor mental health status. There was a statistically significant association between poor mental health status in the age group less than 22 years old and initial academic study year (1st to 3rd of MBBS). Conclusion: The findings are suggestive of a higher prevalence of depression among early-year medical students and marginal predominance in males. Suicidal tendency is also higher. This calls for further investigation with situation analysis, qualitative explorations, and surveys to explore the burden of such disorders in Bangladesh

Heavy hadron spectroscopy and the bag model

Some time ago a slightly improved variant of bag model (the modified bag model) suitable for the unified description of light and heavy hadrons was developed. The main goal of the present work was to calculate the masses of the ground state baryons containing bottom quarks in the framework of this model. For completeness the predictions for other heavy hadrons are also given. The reasonable agreement of our results with other theoretical calculations and available experimental data suggests that our predictions could serve as a useful complementary tool for the interpretation of heavy hadron spectra.Comment: 18 pages, 9 tables, references to experiments updated, rms deviations given in some table