383 research outputs found

    Statistical analysis of soy cultivation in Argentina

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    Argentina are analyzed. The main objective is to obtain information that will be useful for the analysis of the environmental consequences of the progress of this crop in the country. This has been made by a descriptive statistical analysis and a factor analysis was used to identify factors which characterize the soybean crop and also a classification or clustering between provinces with similar characteristics. The information parameters studied were: the tendency and dispersion measures for soybean yield of 15 provinces in which it was grown between the 2001/02 and 2010/11 or from 2001/02 to 2010/11; the correlations between area harvested acreage, seeded area, production and performance, and the factors that bind some variables that characterize the soybean crop that allows a grouping between provinces with similar characteristics. Analyses were performed by using data obtained from: 1) MinAgri (last 10 seasons) b) 2001 National Census c) CNA 2002. From a group of variables: region extension (ha); population density 2001; population of the region in 2001; NBI 2001, literate people older than 10 years 2001; illiterate people older than 10 years 2001; permanent workers in the farming sector 2002; seeded area (ha) 2002; cultivated area of oily plants (ha) 2002; tractors 2002; harvesters 2002; seeded area (ha) 2001/02; harvested area (ha) 2001/02; production (Tn) 2001/02.Fil: Miranda del Fresno, Ma. Carolina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones y Estudios Ambientales; ArgentinaFil: Villacampa, Y.. Universidad de Alicante. Departamento de Qui­mica Orgånica; EspañaFil: Navarro Gonzalez, F. J.. Universidad de Alicante. Departamento de Qui­mica Orgånica; EspañaFil: Sastre Vazquez, P.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Agronomia; Argentin

    The Wnt Receptor Ryk Reduces Neuronal and Cell Survival Capacity by Repressing FOXO Activity During the Early Phases of Mutant Huntingtin Pathogenicity

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    The Wnt receptor Ryk is an evolutionary-conserved protein important during neuronal differentiation through several mechanisms, including Îł-secretase cleavage and nuclear translocation of its intracellular domain (Ryk-ICD). Although the Wnt pathway may be neuroprotective, the role of Ryk in neurodegenerative disease remains unknown. We found that Ryk is up-regulated in neurons expressing mutant huntingtin (HTT) in several models of Huntington's disease (HD). Further investigation in Caenorhabditis elegans and mouse striatal cell models of HD provided a model in which the early-stage increase of Ryk promotes neuronal dysfunction by repressing the neuroprotective activity of the longevity-promoting factor FOXO through a noncanonical mechanism that implicates the Ryk-ICD fragment and its binding to the FOXO co-factor ÎČ-catenin. The Ryk-ICD fragment suppressed neuroprotection by lin-18/Ryk loss-of-function in expanded-polyQ nematodes, repressed FOXO transcriptional activity, and abolished ÎČ-catenin protection of mutant htt striatal cells against cell death vulnerability. Additionally, Ryk-ICD was increased in the nucleus of mutant htt cells, and reducing Îł-secretase PS1 levels compensated for the cytotoxicity of full-length Ryk in these cells. These findings reveal that the Ryk-ICD pathway may impair FOXO protective activity in mutant polyglutamine neurons, suggesting that neurons are unable to efficiently maintain function and resist disease from the earliest phases of the pathogenic process in HD. © 2014 Tourette et al

    Zinc Phthalocyanine−Graphene Hybrid Material for Energy Conversion: Synthesis, Characterization, Photophysics and Photoelectrochemical Cell Preparation

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    Graphene exfoliation upon tip sonication in o-­‐DCB was accomplished. Then, covalent grafting of (2-­‐ aminoethoxy)(tri-­‐tert-­‐butyl) zinc phthalocyanine (ZnPc), to exfoliated graphene sheets was achieved. The newly formed ZnPc-­‐graphene hybrid material was found soluble in common organic solvents without any precipitation for several weeks. Application of diverse spectroscopic techniques verified the successful formation of ZnPc-­‐graphene hybrid materi-­‐ al, while thermogravimetric analysis revealed the amount of ZnPc loading onto graphene. Microscopy analysis based on AFM and TEM was applied to probe the morphological characteristics and to investigate the exfoliation of graphene sheets. Efficient fluorescence quenching of ZnPc in the ZnPc-­‐graphene hybrid material suggested that photoinduced events occur from the photoexcited ZnPc to exfoliated graphene. The dynamics of the photoinduced electron transfer was evaluated by femtosecond transient absorption spectroscopy, thus, revealing the formation of transient species such as ZnPc+ yielding the charge-­‐separated state ZnPc‱+–graphene‱–. Finally, the ZnPc-­‐graphene hybrid material was integrated into a photoactive electrode of an optical transparent electrode (OTE) cast with nanostructured SnO2 films (OTE/SnO2), which exhibited sta le and reproducible photocurrent responses and the incident photon-­‐to-­‐current conversion efficien-­‐ cy was determine

    Urticaria and infections

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    Urticaria is a group of diseases that share a distinct skin reaction pattern. Triggering of urticaria by infections has been discussed for many years but the exact role and pathogenesis of mast cell activation by infectious processes is unclear. In spontaneous acute urticaria there is no doubt for a causal relationship to infections and all chronic urticaria must have started as acute. Whereas in physical or distinct urticaria subtypes the evidence for infections is sparse, remission of annoying spontaneous chronic urticaria has been reported after successful treatment of persistent infections. Current summarizing available studies that evaluated the course of the chronic urticaria after proven Helicobacter eradication demonstrate a statistically significant benefit compared to untreated patients or Helicobacter-negative controls without urticaria (p < 0.001). Since infections can be easily treated some diagnostic procedures should be included in the routine work-up, especially the search for Helicobacter pylori. This review will update the reader regarding the role of infections in different urticaria subtypes

    Intraspecies Variation in the Emergence of Hyperinfectious Bacterial Strains in Nature

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    Salmonella is a principal health concern because of its endemic prevalence in food and water supplies, the rise in incidence of multi-drug resistant strains, and the emergence of new strains associated with increased disease severity. Insights into pathogen emergence have come from animal-passage studies wherein virulence is often increased during infection. However, these studies did not address the prospect that a select subset of strains undergo a pronounced increase in virulence during the infective process- a prospect that has significant implications for human and animal health. Our findings indicate that the capacity to become hypervirulent (100-fold decreased LD50) was much more evident in certain S. enterica strains than others. Hyperinfectious salmonellae were among the most virulent of this species; restricted to certain serotypes; and more capable of killing vaccinated animals. Such strains exhibited rapid (and rapidly reversible) switching to a less-virulent state accompanied by more competitive growth ex vivo that may contribute to maintenance in nature. The hypervirulent phenotype was associated with increased microbial pathogenicity (colonization; cytotoxin production; cytocidal activity), coupled with an altered innate immune cytokine response within infected cells (IFN-ÎČ; IL-1ÎČ; IL-6; IL-10). Gene expression analysis revealed that hyperinfectious strains display altered transcription of genes within the PhoP/PhoQ, PhoR/PhoB and ArgR regulons, conferring changes in the expression of classical virulence functions (e.g., SPI-1; SPI-2 effectors) and those involved in cellular physiology/metabolism (nutrient/acid stress). As hyperinfectious strains pose a potential risk to human and animal health, efforts toward mitigation of these potential food-borne contaminants may avert negative public health impacts and industry-associated losses

    Search for a vector-like quark Tâ€Č → tH via the diphoton decay mode of the Higgs boson in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A search for the electroweak production of a vector-like quark Tâ€Č, decaying to a top quark and a Higgs boson is presented. The search is based on a sample of proton-proton collision events recorded at the LHC at = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. This is the first Tâ€Č search that exploits the Higgs boson decay to a pair of photons. For narrow isospin singlet Tâ€Č states with masses up to 1.1 TeV, the excellent diphoton invariant mass resolution of 1–2% results in an increased sensitivity compared to previous searches based on the same production mechanism. The electroweak production of a Tâ€Č quark with mass up to 960 GeV is excluded at 95% confidence level, assuming a coupling strength ÎșT = 0.25 and a relative decay width Γ/MTâ€Č < 5%

    Measurement of the cross section of top quark-antiquark pair production in association with a W boson in proton-proton collisions at s \sqrt{s} = 13 TeV

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    The production of a top quark-antiquark pair in association with a W boson (ttˉW)(t\bar{t}W) is measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The analyzed data was recorded by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb−1^{−1}. Events with two or three leptons (electrons and muons) and additional jets are selected. In events with two leptons, a multiclass neural network is used to distinguish between the signal and background processes. Events with three leptons are categorized based on the number of jets and of jets originating from b quark hadronization, and the lepton charges. The inclusive (ttˉW)(t\bar{t}W) production cross section in the full phase space is measured to be 868 ± 40(stat) ± 51(syst) fb. The (ttˉW)+(t\bar{t}W)+ and (ttˉW)−(t\bar{t}W)− cross sections are also measured as 553 ± 30(stat) ± 30(syst) and 343 ± 26(stat) ± 25(syst) fb, respectively, and the corresponding ratio of the two cross sections is found to be 1.61±0.15(stat)−0.05+0.07^{+0.07}_{−0.05}(syst). The measured cross sections are larger than but consistent with the standard model predictions within two standard deviations, and represent the most precise measurement of these cross sections to date

    A search for new physics in central exclusive production using the missing mass technique with the CMS detector and the CMS-TOTEM precision proton spectrometer

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    A generic search is presented for the associated production of a Z boson or a photon with an additional unspecified massive particle X, pp → pp + Z/γ + X, in proton-tagged events from proton–proton collisions at √s = 13 TeV, recorded in 2017 with the CMS detector and the CMS-TOTEM precision proton spectrometer. The missing mass spectrum is analysed in the 600–1600 GeV range and a fit is performed to search for possible deviations from the background expectation. No significant excess in data with respect to the background predictions has been observed. odelindependent upper limits on the visible production cross section of pp → pp + Z/γ + X are set

    Search for high-mass exclusive γγ → WW and γγ → ZZ production in proton-proton collisions at s \sqrt{s} = 13 TeV

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    Measurement of the Higgs boson inclusive and differential fiducial production cross sections in the diphoton decay channel with pp collisions at s \sqrt{s} = 13 TeV

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    The measurements of the inclusive and differential fiducial cross sections of the Higgs boson decaying to a pair of photons are presented. The analysis is performed using proton-proton collisions data recorded with the CMS detector at the LHC at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 137 fb−1^{−1}. The inclusive fiducial cross section is measured to be σfidσ_{fid}=73.4−5.3+5.4^{+5.4}_{−5.3}(stat)−2.2+2.4^{+2.4}_{−2.2}(syst) fb, in agreement with the standard model expectation of 75.4 ± 4.1 fb. The measurements are also performed in fiducial regions targeting different production modes and as function of several observables describing the diphoton system, the number of additional jets present in the event, and other kinematic observables. Two double differential measurements are performed. No significant deviations from the standard model expectations are observed
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