2,221 research outputs found

    Abundance trend with condensation temperature for stars with different Galactic birth places

    Full text link
    During the past decade, several studies reported a correlation between chemical abundances of stars and condensation temperature (also known as Tc trend). However, the real astrophysical nature of this correlation is still debated. The main goal of this work is to explore the possible dependence of the Tc trend on stellar Galactocentric distances, Rmean. We used high-quality spectra of about 40 stars observed with the HARPS and UVES spectrographs to derive precise stellar parameters, chemical abundances, and stellar ages. A differential line-by-line analysis was applied to achieve the highest possible precision in the chemical abundances. We confirm previous results that [X/Fe] abundance ratios depend on stellar age and that for a given age, some elements also show a dependence on Rmean. When using the whole sample of stars, we observe a weak hint that the Tc trend depends on Rmean. The observed dependence is very complex and disappears when only stars with similar ages are considered. To conclude on the possible dependence of the Tc trend on the formation place of stars, a larger sample of stars with very similar atmospheric parameters and stellar ages observed at different Galactocentric distances is neededComment: Accepted by A&

    It Is Not Pneumocystis jiroveci (PCP), It Is Cyclophosphamide-Induced Pneumonitis

    Get PDF
    Cyclophosphamide (CYC) is an immunosuppressive medication used to treat life-threatening complications of various rheumatic diseases like vasculitis and systemic lupus erythematosus. A rare side effect of this medication is pneumonitis, which occurs in less than 1% of patients. We describe a case of an 83-year-old woman with a past medical history of microscopic polyangiitis, who presented with progressive dyspnea at rest, exacerbated on exertion, and associated with orthopnea that was attributed to CYC-induced pneumonitis. Three months before this presentation, the patient was diagnosed with antineutrophil cytoplasmic antibodies (ANCA)-positive pauci-immune crescentic and necrotizing glomerulonephritis and started on CYC. On admission, a computed tomography (CT) chest showed worsening bilateral ground-glass opacities in a mosaic distribution and inter and intralobular septal thickening, not present on the CT performed three months prior. The patient underwent an extensive workup, which included an echocardiogram, bronchoscopy with bronchoalveolar lavage, and viral respiratory panel to rule out infectious and cardiac pathologies. She was started on empiric treatment with antibiotics and diuretics, however, despite these interventions, she continued with respiratory distress. A multidisciplinary team convened, and the diagnosis of CYC-induced lung injury was entertained. The CYC was discontinued, and the patient was started on prednisone with significant improvement in symptoms. This case highlights the importance of recognizing CYC as a rare cause of interstitial pneumonitis. When considering CYC-induced lung toxicity, other etiologies, such as opportunistic infections, cardiac etiologies, and diffuse alveolar hemorrhage, should be ruled out

    Sistem√°tica y filogenia de briofitas y plantas vasculares sin semilla en el cono sur

    Get PDF
    Este proyecto propone el estudio sistem√°tico y filogen√©tico de las briofitas (Bryophyta,Marchantiophyta y Anthocerotophyta) y helechos (Clase Polypodiopsidae) en el Cono Sur. En relaci√≥n a las briofitas, durante el √ļltimo siglo se describieron numerosas especies para el √°rea, sin embargo de muchas de ellas se desconoce su situaci√≥n taxon√≥mica real ya que no fueron revisadas posteriormente. En el caso de los helechos, el conocimiento de su diversidad y estado taxon√≥mico es mayor, sin embargo durante los √ļltimos 30 a√Īos los estudios moleculares han revolucionado enteramente la circunscripci√≥n de los grupos en b√ļsqueda de la monofilia de los mismos y actualmente la mayor√≠a de ellos no se encuentran totalmente resueltos. En vista de esta situaci√≥n, en este proyecto nos propusimos inventariar, monitorear e identificar bri√≥fitas y helechos en el contexto de tipos de vegetaci√≥n en el Cono Sur que propendan al conocimiento de la riqueza de especies. Para cumplir con estos objetivos se efect√ļan relevamientos flor√≠sticos en √°reas escasamente inventariadas con √©nfasis en el NOA y NEA. Los espec√≠menes se estudian en base a la metodolog√≠a cl√°sica para estos organismos; la identificaci√≥n se realiza por medio de los ?tipos hist√≥ricos? solicitados en calidad de pr√©stamo a instituciones nacionales e internacionales. Como resultados del primer a√Īo de funcionamiento del proyecto, se ha incrementado el n√ļmero de espec√≠menes briol√≥gicos y pteridol√≥gicos que forman parte del herbario LIL, que permiten mantener un canje activo con instituciones internacionales. Para briofitas se realizaron estudios y descripciones morfo-anat√≥micas de especies nuevas para el √°rea de estudio, as√≠ como nuevas para la ciencia: Mitthenothamnium reduncum (Schimp. ex Mitt.) Ochyra, Asterella chilensis (Nees & Mont.) A. Evans, Pleuridium tucumanensis M. T. Colotti, G. M. Su√°rez y D. F. Peralta sp. nov., Symphyogyna brasiliensis Nees, Syzygiella teres (Carrington & Pearson) V√°√Īa y Fissidens submarginatus Bruch., entre otras. A su vez, se realizaron actualizaciones nomenclaturales, efectuando revisiones a nivel de familia y g√©nero. Se contribuy√≥ con estudios filogen√©ticos para evaluar la monofilia de grupos conflictivos mediante datos morfol√≥gicos y moleculares. Para helechos, se llevaron a cabo descripciones morfo-anat√≥mica para la identificaci√≥n de especies nativas del Cono Sur: Doryopteris triphylla (Lam.) Christ, Pleopeltis macrocarpa (Bory ex. Willd) Kaulf, Notholaena sulphurea (Cav.) Sm., entre otras. Se investigaron las secreciones vegetales de dichas especies, destacando su potencial uso en el campo agron√≥micomedicinal. Tanto para musgos como para helechos se realizaron trabajos de divulgaci√≥n cient√≠fica destinados a comunidades cient√≠ficas no afines a la bot√°nica y poblaci√≥n en general no af√≠n a la ciencia. Cabe destacar tambi√©n, el desarrollo en curso de material did√°ctico estudiantil y docente de nivel medio en escuelas universitarias.Fil: Suarez, Guillermo Martin. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico - Tucum√°n. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucum√°n. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Colotti, M. T.. Universidad Nacional de Tucum√°n. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Neira, Diego Amando. Universidad Nacional de Tucum√°n. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Flores, J. R.. University of Helsinki; FinlandiaFil: Jimenez, Maria Soledad. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico Conicet - Nordeste. Instituto de Bot√°nica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Bot√°nica del Nordeste; ArgentinaFil: Cabral, R.. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico Conicet - Nordeste. Instituto de Bot√°nica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Bot√°nica del Nordeste; ArgentinaFil: Hern√°ndez, Micaela Anah√≠. Fundaci√≥n Miguel Lillo. Direcci√≥n de Bot√°nica; ArgentinaFil: Jimenez, L. I.. Universidad Nacional de Tucum√°n. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Catalano, Santiago Andres. Universidad Nacional de Tucum√°n. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico - Tucum√°n. Unidad Ejecutora Lillo; ArgentinaXIV Jornadas Internas de Comunicaciones en Investigaci√≥n, Docencia y Extensi√≥nSan Miguel de Tucum√°nArgentinaUniversidad Nacional de Tucum√°n. Facultad de Ciencias Naturales e Instituto Miguel Lill

    Prevalence of HIV, Herpes Simplex Virus-2, and Syphilis in male sex partners of pregnant women in Peru

    Get PDF
    <p>Abstract</p> <p>Background:</p> <p>Sexually active heterosexual men may represent an important risk factor for HIV infection and STI transmission to their female partners and unborn children, though little is known about the prevalence of STIs in this population. We sought to determine the prevalence of HIV, herpes simplex virus type 2 (HSV-2), and syphilis infection and associated risk behaviors among male sex partners of pregnant women in Peru.</p> <p>Methods:</p> <p>Survey and seroprevalence data were collected from 1,835 male partners of pregnant women in four cities in Peru. Serum was tested for antibodies to HIV, HSV-2, and syphilis.</p> <p>Results:</p> <p>Among the 1,835 male participants, HIV prevalence was 0.8% (95% CI = 0.5‚Äď1.4%), HSV-2 16.0% (95% CI = 14.3‚Äď17.8%), and syphilis 1.6% (95% CI = 1.0‚Äď2.2%). Additionally, 11.0% reported a lifetime history of intercourse with men, and 37.1% with female sex workers. Unprotected intercourse with men during the previous year was reported by 0.9% and with female sex workers by 1.2%.</p> <p>Conclusion:</p> <p>Pregnant women's sex partners reported lifetime sexual contact with core risk groups, had an elevated prevalence of HSV-2, and demonstrated the potential to spread HIV and other STIs to their partners. Though the prevalence of HIV in the population was not significantly higher than observed in other samples of heterosexuals in Peru, the risk of HIV transmission to their female partners may be exacerbated by their increased prevalence of HSV-2 infection. Further study of heterosexual populations is necessary to fully understand the epidemiology of HIV/STIs in Latin America.</p

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Aboveground forest biomass varies across continents, ecological zones and successional stages: refined IPCC default values for tropical and subtropical forests

    Get PDF
    For monitoring and reporting forest carbon stocks and fluxes, many countries in the tropics and subtropics rely on default values of forest aboveground biomass (AGB) from the Intergovernmental Panel on Climate Change (IPCC) guidelines for National Greenhouse Gas (GHG) Inventories. Default IPCC forest AGB values originated from 2006, and are relatively crude estimates of average values per continent and ecological zone. The 2006 default values were based on limited plot data available at the time, methods for their derivation were not fully clear, and no distinction between successional stages was made. As part of the 2019 Refinement to the 2006 IPCC Guidelines for GHG Inventories, we updated the default AGB values for tropical and subtropical forests based on AGB data from >25 000 plots in natural forests and a global AGB map where no plot data were available. We calculated refined AGB default values per continent, ecological zone, and successional stage, and provided a measure of uncertainty. AGB in tropical and subtropical forests varies by an order of magnitude across continents, ecological zones, and successional stage. Our refined default values generally reflect the climatic gradients in the tropics, with more AGB in wetter areas. AGB is generally higher in old-growth than in secondary forests, and higher in older secondary (regrowth >20 years old and degraded/logged forests) than in young secondary forests (20 years old). While refined default values for tropical old-growth forest are largely similar to the previous 2006 default values, the new default values are 4.0-7.7-fold lower for young secondary forests. Thus, the refined values will strongly alter estimated carbon stocks and fluxes, and emphasize the critical importance of old-growth forest conservation. We provide a reproducible approach to facilitate future refinements and encourage targeted efforts to establish permanent plots in areas with data gaps

    In vitro selection of Remdesivir resistance suggests evolutionary predictability of SARS-CoV-2

    Get PDF
    Remdesivir (RDV), a broadly acting nucleoside analogue, is the only FDA approved small molecule antiviral for the treatment of COVID-19 patients. To date, there are no reports identifying SARS-CoV-2 RDV resistance in patients, animal models or in vitro. Here, we selected drug-resistant viral populations by serially passaging SARS-CoV-2 in vitro in the presence of RDV. Using high throughput sequencing, we identified a single mutation in RNA-dependent RNA polymerase (NSP12) at a residue conserved among all coronaviruses in two independently evolved populations displaying decreased RDV sensitivity. Introduction of the NSP12 E802D mutation into our SARS-CoV-2 reverse genetics backbone confirmed its role in decreasing RDV sensitivity in vitro. Substitution of E802 did not affect viral replication or activity of an alternate nucleoside analogue (EIDD2801) but did affect virus fitness in a competition assay. Analysis of the globally circulating SARS-CoV-2 variants (&gt;800,000 sequences) showed no evidence of widespread transmission of RDV-resistant mutants. Surprisingly, we observed an excess of substitutions in spike at corresponding sites identified in the emerging SARS-CoV-2 variants of concern (i.e., H69, E484, N501, H655) indicating that they can arise in vitro in the absence of immune selection. The identification and characterisation of a drug resistant signature within the SARS-CoV-2 genome has implications for clinical management and virus surveillance

    Search for pair-produced resonances decaying to jet pairs in proton-proton collisions at ‚ąös=8 TeV

    Get PDF
    Results are reported of a general search for pair production of heavy resonances decaying to pairs of hadronic jets in events with at least four jets. The study is based on up to 19.4 fb(-1) of integrated luminosity from proton-proton collisions at a center-of-mass energy of 8 TeV, recorded with the CMS detector at the LHC. Limits are determined on the production of scalar top quarks (top squarks) in the framework of R-parity violating supersymmetry and on the production of color-octet vector bosons (colorons). First limits at the LHC are placed on top squark production for two scenarios. The first assumes decay to a bottom quark and a light-flavor quark and is excluded for masses between 200 and 385 GeV, and the second assumes decay to a pair of light-flavor quarks and is excluded for masses between 200 and 350 GeV at 95% confidence level. Previous limits on colorons decaying to light-flavor quarks are extended to exclude masses from 200 to 835 GeV

    Impact of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients: A nationwide study in Spain

    Get PDF
    Objective To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain. Settings The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied. Participants This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020. Interventions An exploratory factorial analysis was performed to select the most relevant variables of the sample. Primary and secondary outcome measures Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection. Results Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/10 5 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade =3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/10 5 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated. Conclusions Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/10 5 people/week) was a statistically independent predictor of mortality. Trial registration number CEIM 20/217
    • ‚Ķ
    corecore