385 research outputs found
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The contribution of greenhouse gases to the recent slowdown in global-mean temperature trends
The recent slowdown in the rate of increase in global-mean surface temperature (GMST) has generated extensive discussion, but little attention has been given to the contribution of time-varying trends in greenhouse gas concentrations. We use a simple model approach to quantify this contribution. Between 1985 and 2003, greenhouse gases (including well-mixed greenhouse gases, tropospheric and stratospheric ozone, and stratospheric water vapour from methane oxidation) caused a reduction in GMST trend of around 0.03–0.05 K decade−1 which is around 18%–25% of the observed trend over that period. The main contributors to this reduction are the rapid change in the growth rates of ozone-depleting gases (with this contribution slightly opposed by stratospheric ozone depletion itself) and the weakening in growth rates of methane and tropospheric ozone radiative forcing. Although CO2 is the dominant greenhouse gas contributor to GMST trends, the continued increase in CO2 concentrations offsets only about 30% of the simulated trend reduction due to these other contributors. These results emphasize that trends in non-CO2 greenhouse gas concentrations can make significant positive and negative contributions to changes in the rate of warming, and that they need to be considered more closely in analyses of the causes of such variations
Validation and implementation of a diagnostic algorithm for DNA Detection of Bordetella pertussis, B. parapertussis, and B-holmesii in a Pediatric Referral Hospital in Barcelona, Spain
This study aimed to validate a comprehensive diagnostic protocolbased on real-time PCR for the rapid detection and identification ofBordetella per-tussis,Bordetella parapertussis, andBordetella holmesii, as well as its implementationin the diagnostic routine of a reference children’s hospital. The new algorithm in-cluded a triplex quantitative PCR (qPCR) targeting IS481gene (inB. pertussis,B. hol-mesii, and someBordetella bronchisepticastrains), pIS1001(B. parapertussis-specific)andrnaseP as the human internal control. Two confirmatory singleplex tests forB.pertussis(ptxA-Pr) andB. holmesii(hIS1001) were performed if IS481was positive. An-alytical validation included determination of linear range, linearity, efficiency, preci-sion, sensitivity, and a reference panel with clinical samples. Once validated, the newalgorithm was prospectively implemented in children with clinical suspicion ofwhooping cough presenting to Hospital Sant Joan de Deu (Barcelona, Spain) over12 months. Lower limits of detection obtained were 4.4, 13.9, and 27.3 genomicequivalents/ml of sample for IS481(onB. pertussis), pIS1001and hIS1001, and 777.9forptxA-Pr. qPCR efficiencies ranged from 86.0% to 96.9%. Intra- and interassay vari-abilities were 3% and 5%, respectively. Among 566 samples analyzed,B. pertus-sis,B. holmesii, andB. parapertussiswere detected in 11.1%, 0.9% (only in females 4 years old), and 0.2% of samples, respectively. The new algorithm proved to be auseful microbiological diagnostic tool for whooping cough, demonstrating a low rateof other non-pertussis Bordetellaspecies in our surveilled areaPeer ReviewedPostprint (author's final draft
Mitochondria and the NLRP3 Inflammasome in Alcoholic and Nonalcoholic Steatohepatitis
Alcoholic (ASH) and nonalcoholic steatohepatitis (NASH) are advanced stages of fatty liver disease and two of the most prevalent forms of chronic liver disease. ASH and NASH are associated with significant risk of further progression to cirrhosis and hepatocellular carcinoma (HCC), the most common type of liver cancer, and a major cause of cancer-related mortality. Despite extensive research and progress in the last decades to elucidate the mechanisms of the development of ASH and NASH, the pathogenesis of both diseases is still poorly understood. Mitochondrial damage and activation of inflammasome complexes have a role in inducing and sustaining liver damage. Mitochondrial dysfunction produces inflammatory factors that activate the inflammasome complexes. NLRP3 inflammasome (nucleotide-binding oligomerization domain-like receptor protein 3) is a multiprotein complex that activates caspase 1 and the release of pro-inflammatory cytokines, including interleukin-1? (IL-1?) and interleukin-18 (IL-18), and contributes to inflammatory pyroptotic cell death. The present review, which is part of the issue "Mitochondria in Liver Pathobiology", provides an overview of the role of mitochondrial dysfunction and NLRP3 activation in ASH and NASH
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Historical tropospheric and stratospheric ozone radiative forcing using the CMIP6 database
We calculate ozone radiative forcing (RF) and stratospheric
temperature adjustments for the period 1850-2014 using the newly availableCMIP6 ozone dataset. The CMIP6 total ozone RF (1850s-2000s) is 0.28+/-0.17 W m-2 (which is 80% higher than our CMIP5 estimation), and 0.30+/-0.17 W m-2 out to the present day (2014). The total ozone RF grows rapidly until
the 1970s, slows towards the 2000s, and shows a renewed growth thereafter. Since the 1990s the shortwave RF exceeds the longwave RF. Global stratospheric ozone RF is positive between 1930 and 1970 and then turns negative, but remains positive in the Northern Hemisphere throughout. Derived
stratospheric temperature changes show a localized cooling in the subtropical lower stratosphere due to tropospheric ozone increases, and cooling in the upper stratosphere due to ozone depletion by more than 1K already prior to the satellite era (1980), and by more than 2K out to the present day(2014)
Relato de una experiencia: La Maranya, una escuela de democracia ciudadana con jóvenes
El siguiente artÃculo busca difundir una experiencia asociativa
enmarcada por la autogestión juvenil en el municipio de Benicà ssim.
Contamos cómo nace el centro cÃvico La Maranya y cuál es la ideologÃa
desde la que trabaja. La acción de esta asociación surge a partir del trabajo
en el tiempo libre y de ocio como herramienta educativa. El centro
parte de la participación cÃvica y democrática, el aprendizaje directo y
el interés por los problemas de la sociedad para generar una escuela ciudadana
de convivencia igualitaria. Este espacio trabaja con las jóvenes
y los jóvenes como ciudadanas y ciudadanos activos conectados intergeneracionalmente
con otros colectivos que lo conforman dentro de unos
valores de progreso y participación social.Aquest article pretén difondre una experiència associativa
emmarcada per l’autogestió juvenil al municipi de Benicà ssim. Expliquem
el naixement del centre cÃvic La Maranya i quina és la ideologia
des de la qual treballa. L’acció d’aquesta associació sorgeix arran del
treball en el temps lliure i d’esplai com a eina educativa. El centre parteix
de la participació cÃvica i democrà tica, de l’aprenentatge directe i
l’interès pels problemes de la societat per a generar una escola ciutadana
de convivència igualità ria. L’espai treballa amb les persones joves com a ciutadanes i ciutadans actius connectats intergeneracionalment amb
altres col·lectius que el conformen dins de valors de progrés i de participació
social.The following article reports on an associational experience
within the framework of young people’s self-management in the
town of Benicà ssim. We describe how La Maranya Civic Centre came
into being and the ideology it is grounded on. The association’s action
is based on using free time and leisure as an educational tool. The Civic
Centre operates on the basis of democratic participation, non-formal
learning and interest in society’s problems to generate a citizens’ school
for egalitarian coexistence. The centre treats young people as active citizens
who participate as equals with other age groups and associations,
thus providing a context that fosters and promotes values associated with
progress and democratic participation
Binning effects on in-situ raindrop size distribution measurements
This paper investigates the binning effects on drop size distribution (DSD) measurements obtained by Joss-Waldvogel disdrometer (JWD), Precipitation Occurrence Sensor System (POSS), Thies disdrometer (Thies), Parsivel OTT disdrometer, two-dimensional video disdrometer (2DVD) and optical spectro-pluviometer (OSP) instruments, therefore the evaluation comprises non-regular bin sizes and the effect of minimum and maximum measured sizes of drops. To achieve this goal, 2DVD measurements and simulated gamma size distributions were considered. The analysis of simulated gamma DSD binned according each instrument was performed to understand the role of discretisation and truncation effects together on the integral rainfall parameters and estimators of the DSD parameters. In addition, the drop-by-drop output of the 2DVD is binned to simulate the raw output of the other disdrometers which allowed us estimate sampling and binning effects on selected events from available dataset. From simulated DSD it has been found that binning effects exist in integral rainfall parameters and in the evaluation of DSD parameters of a gamma distribution. This study indicates that POSS and JWD exhibit underestimation of concentration and mean diameter due to binning. Thies and Parsivel report a positive bias for rainfall and reflectivity (reaching 5% for heavy rainfall intensity events). Regarding to DSD parameters, distributions of estimators for the shape and scale parameters were analyzed by moment, truncated moment and maximum likelihood methods. They reported noticeable differences between instruments for all methodologies of estimation applied. The measurements of 2DVD allow sampling error estimation of instruments with smaller capture areas than 2DVD. The results show that the instrument differences due to sampling were a~relevant uncertainty but that concentration, reflectivity and mass-weighted diameter were sensitive to binning
Mapping spectroscopic uncertainties into prospective methane retrieval errors from Sentine-5 and its precursor
Sentinel-5 (S5) and its precursor (S5P) are future European satellite missions aiming at global monitoring of methane (CH4) column average dry air mole fractions (XCH4). The spectrometers to be deployed on-board the satellites record spectra of sunlight backscattered from the Earth\u27s surface and atmosphere. In particular, they exploit CH4 absorption in the shortwave infrared spectral range around 1.65 µm (S5 only) and 2.35 µm (both, S5 and S5P) wavelength. Given an accuracy goal of better than 2% for XCH4 to be delivered on regional scales, assessment and reduction of potential sources of systematic error such as spectroscopic uncertainties is crucial. Here, we investigate how spectroscopic errors propagate into retrieval errors on the global scale. To this end, absorption spectra of a ground-based Fourier Transform Spectrometer (FTS) operating at very high spectral resolution serve as estimate for the quality of the spectroscopic parameters. Feeding the FTS fitting residuals as a perturbation into a global ensemble of simulated S5 and S5P-like spectra at relatively low spectral resolution, XCH4 retrieval errors exceed 1% in large parts of the world and show systematic correlations on regional scales, calling for improved spectroscopic parameters
Hypoxia signaling and cholesterol/steroidogenic acute regulatory protein 1 axis: interplay and role in alcohol and non-alcohol-related liver diseases
Metabolic zonation in the liver carries out the maintenance of organ and body homeostasis. Hypoxia is an inherent physiological feature of the liver and contributes to the zonal properties of the hepatic parenchyma. As a master regulator of hypoxia, the transcription factor hypoxia-inducing factor (HIF) is stabilized primarily by oxygen availability, and it is thought to contribute to steatohepatitis due to alcohol-related (ASH) and non-alcohol-related liver disease (NASH). Cholesterol has emerged as an important player in both diseases, and hypoxia increases hepatic cholesterol levels. Steroidogenic acute regulatory protein 1 (STARD1) is a mitochondrial outer membrane protein that transfers cholesterol to mitochondrial inner membrane for metabolic processing and acts as the rate-limiting step in the alternative pathway of bile acid synthesis in hepatocytes. STARD1 expression increases in ASH and NASH and determines the accumulation of cholesterol in mitochondria, which impacts the physico-chemical mitochondrial membranes properties and as a consequence impairs the activity of specific mitochondrial solute carriers, such as the 2-oxoglutarate carrier (2-OGC), limiting the exchange between cytosolic glutathione and mitochondrial 2-oxoglutarate (2-OG). Although HIF-1 is stabilized in hypoxia largely due to the requirement of prolylhydroxylases (PHDs) for oxygen to signal HIF degradation, PHDs are also dependent on 2-OG, and therefore it is conceivable that impairment of 2-OGC by STARD1-mediated cholesterol accumulation may contribute to HIF-1 stabilization due in part to decreased availability of cytosolic 2-OG. In this perspective, this review explores the interplay between HIF-1 stabilization and STARD1 induction and the potential contribution of this functional relationship to ASH and NASH
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