129 research outputs found
The influence of Atlantic High on seasonal rainfall in Argentina
The objective of this work is to quantify the influence of the position and intensity of the Atlantic High (AH) on seasonal rainfall in Argentina. Monthly precipitation data in 68 stations from the National Meteorological Service of Argentina, the Secretariat of Water Resource and the Territorial Authority of the Limay, Neuquén, and Negro rivers basins (AIC) were used. Correlation was the methodology used to identify the link between seasonal rainfall and some indices especially defined to detect the position and intensity of the anticyclone. Precipitation composites of the years when the value of these indices was extremely high (greater than their second tercile) and extremely low (lower than their first tercile) were built for every season. They were analyzed and compared with humidity anomaly transport composites for the same sets of years in order to study circulation patterns associated with seasonal rainfall anomalies. Results indicate that when the AH is intensified, winter rainfall increases in central Argentina and spring rainfall increases in northern Cuyo region. When the AH is displaced towards the north of its mean position, autumn rainfall is favored in the northeast and central and south Patagonia, meanwhile winter and spring rainfall decreases in central Argentina. When the AH is displaced towards the east of its mean position, summer rainfall decreases in Central Andes. Finally, AH indices were used to detect the influence on rainfall in advance. Correlations between seasonal rainfall and the defined indices that characterize the anticyclone in the previous month suggest that there is some rainfall predictability, especially during spring in almost every region in Argentina.Fil: Garbarini, Eugenia María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: González, Marcela Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: Rolla, Alfredo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentin
Molecular Mechanism of DNA Topoisomerase I-Dependent rDNA Silencing: Sir2p Recruitment at Ribosomal Genes
Saccharomyces cerevisiae sir2Δ or top1Δ mutants exhibit similar phenotypes involving ribosomal DNA,
including (i) loss of transcriptional silencing, resulting in non-coding RNA hyperproduction from cryptic RNA
polymerase II promoters; (ii) alterations in recombination; and (iii) a general increase in histone acetylation.
Given the distinct enzymatic activities of Sir2 and Top1 proteins, a histone deacetylase and a DNA
topoisomerase, respectively, we investigated whether genetic and/or physical interactions between the two
proteins could explain the shared ribosomal RNA genes (rDNA) phenotypes. We employed an approach of
complementing top1Δ cells with yeast, human, truncated, and chimeric yeast/human TOP1 constructs and of
assessing the extent of non-coding RNA silencing and histone H4K16 deacetylation. Our findings demonstrate
that residues 115–125 within the yeast Top1p N-terminal domain are required for the complementation
of the top1Δ rDNA phenotypes. In chromatin immunoprecipitation and co-immunoprecipitation experiments,
we further demonstrate the physical interaction between Top1p and Sir2p. Our genetic and biochemical
studies support a model whereby Top1p recruits Sir2p to the rDNA and clarifies a structural role of DNA
topoisomerase I in the epigenetic regulation of rDNA, independent of its known catalytic activity
Expression of Werner and Bloom syndrome genes is differentially regulated by in vitro HIV-1 infection of peripheral blood mononuclear cells
In HIV infection, continuous immune activation leads to accelerated ageing of the adaptive immune system, similar to that observed in elderly people. We investigated the expression of WRN and BLM (genes involved in disorders characterized by premature ageing, genomic instability and cancer predisposition) in peripheral blood mononuclear cells (PBMC) activated in vitro with phytohaemagglutinin (PHA) and infected with different HIV-1 strains. The steady state levels of mRNA were analysed by reverse transcription-polymerase chain reaction (RT-PCR), and protein expression was assayed using immunocytochemistry and Western blot techniques. In uninfected PBMC, PHA stimulation induced an increase in BLM mRNA and protein expression, while WRN expression remained virtually unchanged. When PBMC were infected in vitro with a lymphotropic HIV-1 strain, the level of BLM mRNA showed a peak at 24 h of infection, followed by a decline to uninfected culture levels. A similar result failed to be seen using an R5-tropic HIV-1 strain. In accordance with mRNA expression, in HIV-infected cultures PBMC were stained more frequently and more intensely by a BLM-specific antibody as compared to uninfected cultures, staining peaking at 24. Conversely, WRN expression was not modulated by HIV-1. The proportion of cells showing BLM up-regulation, established by immunocytochemical staining, was much greater than the proportion of productively infected PBMC, as established by proviral DNA measurement. This result indicates that BLM up-regulation is probably a result of an indirect bystander cell effect. Activation of the BLM gene in infected PBMC suggests that premature ageing could be a further immunopathogenetic mechanism involved in HIV-induced immunodeficiency, and points to a possible new candidate target for innovative therapeutic intervention
Climatología de la difusión atmosférica de la zona de Campana (prov. Buenos Aires)
El estudio de la dispersión de contaminantes en la atmósfera es una de las etapas principales en la solución del problema de la contaminación del aire. En este trabajo se presentan y discuten aspectos meteorológicos y de difusión atmosférica en la zona de Campana (Prov. Buenos Aires) como etapa inicial de un proyecto tendiente a desarrollar y aplicar un modelo climatológico de contaminación del aire. Los datas meteorológicos utilizados provienen de la estación INTA Delta. Se encuentra que los contaminantes em itidos desde la zona industrial ubicada en el sector V-N y N-E de la ciudad interactuando con la capa límite, interna generada al atravesar el aire el límite río Paraná-tierra provocarían condiciones de fumigación en más del <0% de todos los casos. Esta situación podría ser la causa de la contaminación del aire urbano.Atmospheric transport and diffusion processes are tvo of the main aspects in the air pollution problem. Some meteorological and diffusion characteristics of Campana City and its surroundings are discussed in this paper, tending to develop a dimatological model of atmospheric pollution. Meteorological data vere provided by INTA Delta Station It tras found that pollutants emitted from the industrial area. situated in the lMi and N-E sectors , could produce fumigation conditions in more than 407. of total cases. Urban air pollution in this area could have its origin in this reason.Asociación Argentina de Geofísicos y Geodesta
In-cell NMR characterization of the secondary structure populations of a disordered conformation of α-Synuclein within E. coli cells
α-Synuclein is a small protein strongly implicated in the pathogenesis of Parkinson’s disease and related neurodegenerative disorders. We report here the use of in-cell NMR spectroscopy to observe directly the structure and dynamics of this protein within E. coli cells. To improve the accuracy in the measurement of backbone chemical shifts within crowded in-cell NMR spectra, we have developed a deconvolution method to reduce inhomogeneous line broadening within cellular samples. The resulting chemical shift values were then used to evaluate the distribution of secondary structure populations which, in the absence of stable tertiary contacts, are a most effective way to describe the conformational fluctuations of disordered proteins. The results indicate that, at least within the bacterial cytosol, α-synuclein populates a highly dynamic state that, despite the highly crowded environment, has the same characteristics as the disordered monomeric form observed in aqueous solution
Chronic non-cancer pain in primary care: an Italian cross-sectional study
Chronic non-cancer pain is a complex health condition that affects more than a quarter
of the Italian population who mainly refers to general practitioners and primary care
for their treatment. There are little information on the epidemiological and clinical
characteristics and types of treatments for these patients who suffer from chronic pain.
The aim of the study was to provide epidemiological and clinical information about
patients with chronic non-cancer pain who refers to GPs for their treatment. An
observational, multicentre, cross-sectional study was carried out using retrospectively
reviewed clinical records from 29 GPs. Some pharmacoeconomic aspects were also
investigated. A total of 1,007 patients who had chronic pain were selected for the study.
Chronic pain was more common in women than in men (ratio 2.7 : 1) (P = 0.002).
With regard to incomes, the women earned less than the men (P = 0.017). The chronic
pain was musculoskeletal (73.4%), mixed (21.4%), neuropathic (4.9%) and visceral
(0.3%). More women than men had pain in two or more sites, and 33.5% of the patients
reported more than one diagnosis that related to chronic pain. The general practitioners
had prescribed nonsteroidal anti-inflammatory drugs for 71.8% of the cases, opioids for
16.9%, adjuvants for 9.0% and acetaminophen for 2.4%, and about pharmacoeconomic
aspects, the total cost for the sample was €111,331.42. Primary care is the essential
frontline for patients who suffer from non-cancer pain. An interdisciplinary assessment
and approach should start in primary care delivery to maximize the clinical outcomes
Chapter 11 - Near-term climate change: Projections and predictability
This chapter assesses the scientific literature describing expectations for near-term climate (present through mid-century). Unless otherwise stated, "near-term" change and the projected changes below are for the period 2016-2035 relative to the reference period 1986-2005. Atmospheric composition (apart from CO2; see Chapter 12) and air quality projections through to 2100 are also assessed
Co-circulation of the two influenza B lineages during 13 consecutive influenza surveillance seasons in Italy, 2004-2017
BACKGROUND: Since 1985, two antigenically distinct lineages of influenza B viruses (Victoria-like and Yamagata-like) have circulated globally. Trivalent seasonal influenza vaccines contain two circulating influenza A strains but a single B strain and thus provide limited immunity against circulating B strains of the lineage not included in the vaccine. In this study, we describe the characteristics of influenza B viruses that caused respiratory illness in the population in Italy over 13 consecutive seasons of virological surveillance, and the match between the predominant influenza B lineage and the vaccine B lineage, in each season. METHODS: From 2004 to 2017, 26,886 laboratory-confirmed influenza cases were registered in Italy, of which 18.7% were type B. Among them, the lineage of 2465 strains (49%) was retrieved or characterized in this study by a real-time RT-PCR assay and/or sequencing of the hemagglutinin (HA) gene. RESULTS: Co-circulation of both B lineages was observed each season, although in different proportions every year. Overall, viruses of B/Victoria and B/Yamagata lineages caused 53.3 and 46.7% of influenza B infections, respectively. A higher proportion of infections with both lineages was detected in children, and there was a declining frequency of B/Victoria detections with age. A mismatch between the vaccine and the predominant influenza B lineage occurred in eight out of thirteen influenza seasons under study. Considering the seasons when B accounted for >\u200920% of all laboratory-confirmed influenza cases, a mismatch was observed in four out of six seasons. Phylogenetic analysis of the HA1 domain confirmed the co-circulation of both lineages and revealed a mixed circulation of distinct evolutionary viral variants, with different levels of match to the vaccine strains. CONCLUSIONS: This study contributes to the understanding of the circulation of influenza B viruses in Italy. We found a continuous co-circulation of both B lineages in the period 2004-2017, and determined that children were particularly vulnerable to Victoria-lineage influenza B virus infections. An influenza B lineage mismatch with the trivalent vaccine occurred in about two-thirds of cases
The Impact of Small Molecule Binding on the Energy Landscape of the Intrinsically Disordered Protein C-Myc
Intrinsically disordered proteins are attractive therapeutic targets owing to their prevalence in several diseases. Yet their lack of well-defined structure renders ligand discovery a challenging task. An intriguing example is provided by the oncoprotein c-Myc, a transcription factor that is over expressed in a broad range of cancers. Transcriptional activity of c-Myc is dependent on heterodimerization with partner protein Max. This protein-protein interaction is disrupted by the small molecule 10058-F4 (1), that binds to monomeric and disordered c-Myc. To rationalize the mechanism of inhibition, structural ensembles for the segment of the c-Myc domain that binds to 1 were computed in the absence and presence of the ligand using classical force fields and explicit solvent metadynamics molecular simulations. The accuracy of the computed structural ensembles was assessed by comparison of predicted and measured NMR chemical shifts. The small molecule 1 was found to perturb the composition of the apo equilibrium ensemble and to bind weakly to multiple distinct c-Myc conformations. Comparison of the apo and holo equilibrium ensembles reveals that the c-Myc conformations binding 1 are already partially formed in the apo ensemble, suggesting that 1 binds to c-Myc through an extended conformational selection mechanism. The present results have important implications for rational ligand design efforts targeting intrinsically disordered proteins
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