672 research outputs found

    DOPING: a New Non-parametric Deprojection Scheme

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    We present a new non-parametric deprojection algorithm DOPING (Deprojection of Observed Photometry using and INverse Gambit), that is designed to extract the three dimensional luminosity density distribution Ļ\rho, from the observed surface brightness profile of an astrophysical system such as a galaxy or a galaxy cluster, in a generalised geometry, while taking into account changes in the intrinsic shape of the system. The observable is the 2-D surface brightness distribution of the system. While the deprojection schemes presented hitherto have always worked within the limits of an assumed intrinsic geometry, in DOPING, geometry and inclination can be provided as inputs. The Ļ\rho that is most likely to project to the observed brightness data is sought; the maximisation of the likelihood is performed with the Metropolis algorithm. Unless the likelihood function is maximised, Ļ\rho is tweaked in shape and amplitude, while maintaining positivity, but otherwise the luminosity distribution is allowed to be completely free-form. Tests and applications of the algorithm are discussed.Comment: 8 pages; to be published in IJMP(D) (Feb, 2008 issue), Vol 17, No. 2, as part of proceedings for the 6th International Workshop on Data Analysis in Astronomy, ``Modelling and Simulations in Science'

    Supra-Molecular Assemblies of ORAI1 at Rest Precede Local Accumulation into Puncta after Activation

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    The Ca2+ selective channel ORAI1 and endoplasmic reticulum (ER)-resident STIM proteins form the core of the channel complex mediating store operated Ca2+ entry (SOCE). Using liquid phase electron microscopy (LPEM), the distribution of ORAI1 proteins was examined at rest and after SOCEactivation at nanoscale resolution. The analysis of over seven hundred thousand ORAI1 positions revealed a number of ORAI1 channels had formed STIM-independent distinct supra-molecular clusters. Upon SOCE activation and in the presence of STIM proteins, a fraction of ORAI1 assembled in micron-sized two-dimensional structures, such as the known puncta at the ER plasma membrane contact zones, but also in divergent structures such as strands, and ring-like shapes. Our results thus question the hypothesis that stochastically migrating single ORAI1 channels are trapped at regions containing activated STIM, and we propose instead that supra-molecular ORAI1 clusters fulfill an amplifying function for creating dense ORAI1 accumulations upon SOCE-activation

    Prevalence of Depressive Disorder in the Adult population of Latin America: a systematic review and meta-analysis

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    Background: Depressive disorder is one of the leading causes of disability worldwide; however its prevalence and association with inequality and crime is poorly characterised in Latin America. This study aimed to: i. systematically review population-based studies of prevalence of ICD/DSM depressive disorder in Latin America, ii. report pooled regional, country, and sex-specific prevalence estimates, and iii. test its association with four country-level development indicators: human development (HDI), income (Gini) and gender inequality (GII), and intentional homicide rate (IHR). Methods: We conducted a systematic review and meta-analysis of population-based studies reporting primary data on the prevalence of ICD/DSM depressive disorder in Latin America from 1990 to 2023, irrespective of language. We searched PubMed, PsycINFO, Cochrane Library, SciELO (regional database), LILAC (regional database), and available grey literature. Study quality was assessed using JBIā€™s critical appraisal tools. We generated pooled estimates using random-effects meta-analysis; heterogeneity was assessed using the I2 statistic. Meta-regression analyses were used to test associations of depression prevalence with indicators of inequality and human development. The study was registered with PROSPERO (CRD42019143054). Findings: Using data from 40 studies in Latin America, lifetime, 12-month, and current prevalence of ICD/DSM depressive disorder were calculated at 12.58% (95% CI 11.00%ā€“14.16%); 5.30% (4.55ā€“6.06%), and 3.12% (2.22ā€“4.03), respectively. Heterogeneity was high across lifetime, 12-month, and current prevalence, sex, and countries. 12-month and current prevalence was associated with higher Gini and GII, 12-month prevalence with lower HDI, and current prevalence with higher IHR. Interpretation We found a high prevalence of ICD/DSM depressive disorders in Latin America, and a statistically significant association with inequality and development indicators. The high heterogeneity found across prevalence periods and the major gaps in country representation underscore the need to escalate efforts to improve mental health access and research capabilities in Latin America. Systematic, comparable prevalence estimates would inform more effective decision-making in the region

    The antiproliferative effect of mulberry (Morus alba L.) plant on hepatocarcinoma cell line HepG2

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    AbstractThis study aimed to investigate the antiproliferative effect of aqueous and organic extracts of mulberry leaves (Morus Alba L.) on human hepatocellular carcinoma HepG2 cell line. Mulberry leaf extracts were prepared using the solvents: water, 50% aqueous MeOH, and 100% MeOH for different time intervals, while the cells treated with dimethyl sulfoxide (DMSO) served as control. The effects of aqueous and organic extracts of M. alba L. leaves on HepG2 cell viability, nuclear factor kappa B (NF-ĪŗB) gene expression, alfa-fetoprotein (AFP), albumin (ALB), gamma-glutamyl transpeptidase (Ī³-GT) and alkaline phosphatase (ALP) were measured. The results of the cell viability assays showed that water, 50% aqueous MeOH, and 100% MeOH extracts exhibited a highly significant inhibitory effect on HepG2 cell proliferation which was evidenced by a reduction in viable cell count. The results were confirmed by microscopical examination of cell morphology. Furthermore, the mulberry leaf extracts suppressed the activity of NF-ĪŗB gene expression of HepG2 cells compared to the control. Also a highly significant depression occurred at the levels of AFP, Ī³-GT and ALP in HepG2 cells compared with that of controls in a time dependent manner. By contrast, the mulberry leaf extracts increased the secretion of ALB. Therefore, the conclusion was that the organic and aqueous extracts of mulberry leaves inhibit the growth of HepG2 cells through suppressing the activity of NF-ĪŗB gene expression and modulate the biochemical markers

    Global Precipitation Measurement (GPM): Unified Precipitation Estimation From Space

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    Global Precipitation Measurement (GPM) is an international satellite mission that uses measurements from an advanced radar/radiometer system on a Core Observatory as reference standards to unify and advance precipitation estimates through a constellation of research and operational microwave sensors. GPM is a science mission focusing on a key component of the Earth's water and energy cycle, delivering near real-time observations of precipitation for monitoring severe weather events, freshwater resources, and other societal applications. This work presents the GPM mission design, together with descriptions of sensor characteristics, inter-satellite calibration, retrieval methodologies, ground validation activities, and societal applications

    Corporate Hierarchies and the Size of Nations: Theory and Evidence

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    Corporate organization varies within a country and across countries with country size. The paper starts by establishing some facts about corporate organization based on unique data of 660 Austrian and German corporations. The larger country (Germany) has larger firms with flatter more decentral corporate hierarchies compared to the smaller country (Austria). Firms in the larger country change their organization less fast than firms in the smaller country. Over time firms have been introducing less hierarchical organizations by delegating power to lower levels of the corporation. We develop a theory which explains these facts and which links these features to the trade environment that countries and firms face. We introduce firms with internal hierarchies in a Krugman (1980) model of trade. We show that international trade and the toughness of competition in international markets induce a power struggle in firms which eventually leads to decentralized corporate hierarchies. We offer econometric evidence which is consistent with the models predictions

    c-di-GMP modulates type IV MSHA pilus retraction and surface attachment in Vibrio cholerae.

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    Biofilm formation by Vibrio cholerae facilitates environmental persistence, and hyperinfectivity within the host. Biofilm formation is regulated by 3',5'-cyclic diguanylate (c-di-GMP) and requires production of the type IV mannose-sensitive hemagglutinin (MSHA) pilus. Here, we show that the MSHA pilus is a dynamic extendable and retractable system, and its activity is directly controlled by c-di-GMP. The interaction between c-di-GMP and the ATPase MshE promotes pilus extension, whereas low levels of c-di-GMP correlate with enhanced retraction. Loss of retraction facilitated by the ATPase PilT increases near-surface roaming motility, and impairs initial surface attachment. However, prolonged retraction upon surface attachment results in reduced MSHA-mediated surface anchoring and increased levels of detachment. Our results indicate that c-di-GMP directly controls MshE activity, thus regulating MSHA pilusĀ extension and retraction dynamics, and modulating V. cholerae surface attachment and colonization

    Infectious Complications of Ventricular Assist Device Use in Children in the US: Data from the Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs)

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    Background Infections are frequent in pediatric ventricular assist device (VAD) patients. In this study we aimed to describe infections in durable VAD patients reported to Pedimacs. Methods Durable VAD data from the Pedimacs registry (September 19, 2012 to December 31, 2015) were analyzed. Infections were described with standard descriptive statistics, Kaplanā€“Meier analysis and competing outcomes analysis. Results There were 248 implants in 222 patients, with a mean age and a median follow-up of 11 Ā± 6.4 years and 2.4 patient-months (<1 day to 2.6 years), respectively. Device types were pulsatile flow (PF) in 91 (41%) patients and continuous flow (CF) in 131 (59%) patients. PF patients were younger (4 Ā± 4 vs 14 Ā± 4 years; p < 0.0001) and were more likely to have congenital heart disease (25% vs 12%; p = 0.03), prior surgery (53% vs 26%; p < 0.0001) and prior extracorporeal membrane oxygenation (24% vs 7%; p = 0.0003). Infection accounted for 17% (96 of 564) of the reported adverse events (AEs). A non-device infection was most common (51%), followed by sepsis (24%), external pump component infection (20%) and internal pump component infection (5%). Most infections were bacterial (73%) and required intravenous therapy only (77%). The risk of infection in the constant phase was higher in patients with a history of prior infection and in patients with a history of a non-infectious major AEs. Survival was lower after infection only in CF patients (p = 0.008). Conclusions Infection was the most common AE after pediatric VAD implantation. Non-device infections were most common. The best predictor of a future infection was a past infection. CF patients have higher risk of death after an infection

    Asc-Dependent and Independent Mechanisms Contribute to Restriction of Legionella Pneumophila Infection in Murine Macrophages

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    The apoptosis-associated speck-like protein containing a caspase recruitment domain (Asc) is an adaptor molecule that mediates inflammatory and apoptotic signals. Legionella pneumophila is an intracellular bacterium and the causative agent of Legionnaire's pneumonia. L. pneumophila is able to cause pneumonia in immuno-compromised humans but not in most inbred mice. Murine macrophages that lack the ability to activate caspase-1, such as caspase-1āˆ’/āˆ’ and Nlrc4āˆ’/āˆ’ allow L. pneumophila infection. This permissiveness is attributed mainly to the lack of active caspase-1 and the absence of its down stream substrates such as caspase-7. However, the role of Asc in control of L. pneumophila infection in mice is unclear. Here we show that caspase-1 is moderately activated in Ascāˆ’/āˆ’ macrophages and that this limited activation is required and sufficient to restrict L. pneumophila growth. Moreover, Asc-independent activation of caspase-1 requires bacterial flagellin and is mainly detected in cellular extracts but not in culture supernatants. We also demonstrate that the depletion of Asc from permissive macrophages enhances bacterial growth by promoting L. pneumophila-mediated activation of the NF-ĪŗB pathway and decreasing caspase-3 activation. Taken together, our data demonstrate that L. pneumophila infection in murine macrophages is controlled by several mechanisms: Asc-independent activation of caspase-1 and Asc-dependent regulation of NF-ĪŗB and caspase-3 activation

    PROTECTIVE EFFECT OF SOME CHELATING AGENTS AND ANTIOXIDANTS ON THE BIOHAZARDS PRODUCED FROM WATER POLLUTION BY HEAVY METALS IN WISTAR RATS: BIOLOGICAL, GENETIC AND HISTOPATHOLOGICAL STUDY

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    Background: Heavy metals that normally cause problems are mercury (HgCl2) and lead acetate (LA). Chelating and inhibitor agents are the target to treat and overcome metal toxicity. The current study has been carried out to evaluate the protective effects of N-acetyl cysteine (NAC) and meso 2,3 dimercaptosuccinic acid (DMSA) against HgCl2 and LA toxicity. Materials and Methods: Ninety male Wistar rats were divided into nine equal groups. The groups were administered NAC and/or DMSA in presence or absence of LA (LA; 0.2% in drinking water) or HgCl2 (2 mg/kg BW) for 2 consecutive months. Serum and organs were collected for biochemical, genetic and histopathological changes. Results: Biochemical results revealed that LA and HgCl2 significantly increased the levels of liver and kidney biomarkers. Administration of NAC and DMSA considerably improved these altered changes. LA and HgCl2 decreased serum levels of antioxidants and were ameliorated in NAC and DMSA administered rats. LA and HgCl2 administration upregulated expression of IL-1Ī² and IL-8 that were normalized by NAC and DMSA. Kidneys of LA and HgCl2 groups showed intraluminal hyaline casts. Kidneys of DMSA-administrated rats showed mild hydropic degeneration of renal tubular epithelium in LA and HgCl2 groups. Kidneys of NAC administrated rats showed atrophy of capillary tufts. Kidneys of LA and HgCl2 administered rats which received DMSA and NAC showed normal glomerular structure. Liver histopathology showed sever changes that were ameliorated by NAC and DMSA. Conclusion: Taken together, usage of NAC and DMSA provide significant protection against LA and HgCl2-induced hepatotoxicity and nephrotoxicity in male Wistar rats
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