Showing papers by "National University of La Plata published in 2013"
TL;DR: The Cherenkov Telescope Array (CTA) as discussed by the authors is a very high-energy (VHE) gamma ray observatory with an international collaboration with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America.
701 citations
TL;DR: In this article, the luminosity calibration for the ATLAS detector at the LHC during pp collisions at root s = 7 TeV in 2010 and 2011 is presented, and a luminosity uncertainty of delta L/L = +/- 3.5 % is obtained.
Abstract: The luminosity calibration for the ATLAS detector at the LHC during pp collisions at root s = 7 TeV in 2010 and 2011 is presented. Evaluation of the luminosity scale is performed using several luminosity-sensitive detectors, and comparisons are made of the long-term stability and accuracy of this calibration applied to the pp collisions at root s = 7 TeV. A luminosity uncertainty of delta L/L = +/- 3.5 % is obtained for the 47 pb(-1) of data delivered to ATLAS in 2010, and an uncertainty of delta L/L = +/- 1.8 % is obtained for the 5.5 fb(-1) delivered in 2011.
499 citations
TL;DR: It was demonstrated that glyphosate and AMPA are present in soils under agricultural activity, and it was found that in stream samples the presence of glyphosate and aminomethylphosphonic acid is relatively more frequent in suspended particulate matter and sediment than in water.
383 citations
TL;DR: In this article, a tailored household survey provides evidence on systematic biases in individuals' evaluations of their own relative position in the income distribution and explores their potential impact on preferences for redistribution.
326 citations
TL;DR: In this paper, the authors measured the effect of jet suppression in heavy ion collisions at the LHC and provided a direct sensitivity to the physics of jet quenching, using a sample of lead-lead collisions at root S-NN = 2.76 TeV.
239 citations
01 Apr 2013
TL;DR: The Consenso de los Commodities as discussed by the authors subraya the ingreso of America Latina in un nuevo orden economico and politico-ideologico, sostenido by el boom de los precios internacionales de las materias primas and los bienes de consumo demandados cada vez mas por los paises centrales and las potencias emergentes.
Abstract: El «Consenso de los Commodities» subraya el ingreso de America Latina en un nuevo orden economico y politico-ideologico, sostenido por el boom de los precios internacionales de las materias primas y los bienes de consumo demandados cada vez mas por los paises centrales y las potencias emergentes Este orden va consolidando un estilo de desarrollo neoextractivista que genera ventajas comparativas, visibles en el crecimiento economico, al tiempo que produce nuevas asimetrias y conflictos sociales, economicos, ambientales y politico-culturales Tal conflictividad marca la apertura de un nuevo ciclo de luchas, centrado en la defensa del territorio y del ambiente, asi como en la discusion sobre los modelos de desarrollo y las fronteras mismas de la democracia
234 citations
TL;DR: Evidence for selection acting on the Bd genome is reported, supporting the hypothesis that protease genes are important in evolutionary transitions in this group, and it is found that even the most recently evolved Bd clade contained more genetic variation than previously reported.
Abstract: Understanding the evolutionary history of microbial pathogens is critical for mitigating the impacts of emerging infectious diseases on economically and ecologically important host species. We used a genome resequencing approach to resolve the evolutionary history of an important microbial pathogen, the chytrid Batrachochytrium dendrobatidis (Bd), which has been implicated in amphibian declines worldwide. We sequenced the genomes of 29 isolates of Bd from around the world, with an emphasis on North, Central, and South America because of the devastating effect that Bd has had on amphibian populations in the New World. We found a substantial amount of evolutionary complexity in Bd with deep phylogenetic diversity that predates observed global amphibian declines. By investigating the entire genome, we found that even the most recently evolved Bd clade (termed the global panzootic lineage) contained more genetic variation than previously reported. We also found dramatic differences among isolates and among genomic regions in chromosomal copy number and patterns of heterozygosity, suggesting complex and heterogeneous genome dynamics. Finally, we report evidence for selection acting on the Bd genome, supporting the hypothesis that protease genes are important in evolutionary transitions in this group. Bd is considered an emerging pathogen because of its recent effects on amphibians, but our data indicate that it has a complex evolutionary history that predates recent disease outbreaks. Therefore, it is important to consider the contemporary effects of Bd in a broader evolutionary context and identify specific mechanisms that may have led to shifts in virulence in this system.
234 citations
TL;DR: In this article, the authors measured the jet energy resolution using data recorded with the ATLAS detector in proton-proton collisions at root s = 7 TeV, which corresponds to an integrated luminosity of 35 pb(-1).
Abstract: The measurement of the jet energy resolution is presented using data recorded with the ATLAS detector in proton-proton collisions at root s = 7 TeV. The sample corresponds to an integrated luminosity of 35 pb(-1). Jets are reconstructed from energy deposits measured by the calorimeters and calibrated using different jet calibration schemes. The jet energy resolution is measured with two different in situ methods which are found to be in agreement within uncertainties. The total uncertainties on these measurements range from 20 % to 10 % for jets within vertical bar y vertical bar < 2.8 and with transverse momenta increasing from 30 GeV to 500 GeV. Overall, the Monte Carlo simulation of the jet energy resolution agrees with the data within 10 %.
212 citations
TL;DR: An adaptive second-order sliding mode control strategy to maximize the energy production of a wind energy conversion system (WECS) simultaneously reducing the mechanical stress on the shaft using a modified version of the super-twisting (ST) algorithm with variable gains is explored.
Abstract: This work explores an adaptive second-order sliding mode control strategy to maximize the energy production of a wind energy conversion system (WECS) simultaneously reducing the mechanical stress on the shaft. Such strategy successfully deals with the random nature of wind speed, the intrinsic nonlinear behavior of the WECS, and the presence of model uncertainties and external perturbations acting on the system. The synthesized adaptive controller is designed from a modified version of the super-twisting (ST) algorithm with variable gains. The suitability of the proposed strategy is proved by extensive computer-aided simulations employing a comprehensive model of the system emulating realistic conditions of operation, i.e., considering variations in the parameters and including external disturbances. Additionally, a second controller based on the traditional ST algorithm is also designed and simulated. Results are presented and discussed in order to establish a comparison framework.
208 citations
TL;DR: The complex network of cross-communication between oxidants and antioxidants in the redox signalling hub and the different hormone signalling pathways maximises productivity under stress-free situations and regulates plant growth, development, reproduction, programmed cell death and survival upon exposure to stress.
208 citations
TL;DR: In this paper, a fine and homogeneous grid of evolutionary sequences for helium (He) core white dwarfs for the whole range of their expected masses (0.15 − 0.45 ) is provided.
Abstract: Context. The number of detected extremely low-mass (ELM) white dwarf stars has increased drastically in recent years, thanks to the results of many surveys. In addition, some of these stars have been found to exhibit pulsations, making them potential targets for asteroseismology.Aims. We provide a fine and homogeneous grid of evolutionary sequences for helium (He) core white dwarfs for the whole range of their expected masses (0.15 ≲ M ∗ /M ⊙ ≲ 0.45), including the mass range for ELM white dwarfs (M ∗ /M ⊙ ≲ 0.20). The grid is appropriate for mass and age determination of these stars, as well as for studying their adiatabic pulsational properties.Methods. White dwarf sequences have been computed by performing full evolutionary calculations that consider the main energy sources and processes of chemical abundance changes during white dwarf evolution. Realistic initial models for the evolving white dwarfs have been obtained by computing the nonconservative evolution of a binary system consisting of an initially 1 M ⊙ ZAMS star and a 1.4 M ⊙ neutron star for various initial orbital periods. To derive cooling ages and masses for He-core white dwarfs, we perform a least square fitting of the M (T eff ,g ) and Age(T eff ,g ) relations provided by our sequences by using a scheme that takes into account the time spent by models in different regions of the T eff − g plane. This is particularly useful when multiple solutions for cooling age and mass determinations are possible in the case of CNO-flashing sequences. We also explore in a preliminary way the adiabatic pulsational properties of models near the critical mass for the development of CNO flashes (~0.2 M ⊙ ). This is motivated by the discovery of pulsating white dwarfs with stellar masses near this threshold value. Results. We obtain reliable and homogeneous mass and cooling age determinations for 58 very low-mass white dwarfs, including three pulsating stars. Also, we find substantial differences in the period spacing distributions of g -modes for models with stellar masses near ~ 0.2 M ⊙ , which could be used as a seismic tool to distinguish stars that have undergone CNO flashes in their early cooling phase from those that have not. Finally, for an easy application of our results, we provide a reduced grid of values useful to obtain the masses and ages of He-core white dwarfs.
TL;DR: Techniques and protocols for American foulbrood research are provided, mostly in a recipe-like format that permits easy implementation in the laboratory and other technical information including biosafety measures to guarantee the safe handling of this pathogen is covered.
Abstract: Summary American foulbrood is one of the most devastating diseases of the honey bee. It is caused by the spore-forming, Gram-positive rod-shaped bacterium Paenibacillus larvae. The recent updated genome assembly and annotation for this pathogen now permits in-depth molecular studies. In this paper, selected techniques and protocols for American foulbrood research are provided, mostly in a recipe-like format that permits easy implementation in the laboratory. Topics covered include: working with Paenibacillus larvae, basic microbiological techniques, experimental infection, and “’omics” and other sophisticated techniques. Further, this chapter covers other technical information including biosafety measures to guarantee the safe handling of this pathogen.
TL;DR: The 1000 Genomes Project provides a unique opportunity for improving our understanding of population genetic history by providing over a hundred sequenced low coverage genomes and exomes from Colombian (CLM), Mexican-American (MXL), and Puerto Rican (PUR) populations.
Abstract: There is great scientific and popular interest in understanding the genetic history of populations in the Americas. We wish to understand when different regions of the continent were inhabited, where settlers came from, and how current inhabitants relate genetically to earlier populations. Recent studies unraveled parts of the genetic history of the continent using genotyping arrays and uniparental markers. The 1000 Genomes Project provides a unique opportunity for improving our understanding of population genetic history by providing over a hundred sequenced low coverage genomes and exomes from Colombian (CLM), Mexican-American (MXL), and Puerto Rican (PUR) populations. Here, we explore the genomic contributions of African, European, and especially Native American ancestry to these populations. Estimated Native American ancestry is in MXL, in CLM, and in PUR. Native American ancestry in PUR is most closely related to populations surrounding the Orinoco River basin, confirming the Southern America ancestry of the Taino people of the Caribbean. We present new methods to estimate the allele frequencies in the Native American fraction of the populations, and model their distribution using a demographic model for three ancestral Native American populations. These ancestral populations likely split in close succession: the most likely scenario, based on a peopling of the Americas thousand years ago (kya), supports that the MXL Ancestors split kya, with a subsequent split of the ancestors to CLM and PUR kya. The model also features effective populations of in Mexico, in Colombia, and in Puerto Rico. Modeling Identity-by-descent (IBD) and ancestry tract length, we show that post-contact populations also differ markedly in their effective sizes and migration patterns, with Puerto Rico showing the smallest effective size and the earlier migration from Europe. Finally, we compare IBD and ancestry assignments to find evidence for relatedness among European founders to the three populations.
TL;DR: In this paper, the production of W bosons in association with two jets in proton-proton collisions at a center-of-mass energy of root s = 7 TeV has been analyzed for the presence of double-parton interactions using data corresponding to an integrated luminosity of 36 pb(-1), collected with the ATLAS detector at the Large Hadron Collider.
Abstract: The production of W bosons in association with two jets in proton-proton collisions at a centre-of-mass energy of root s = 7 TeV has been analysed for the presence of double-parton interactions using data corresponding to an integrated luminosity of 36 pb(-1), collected with the ATLAS detector at the Large Hadron Collider. The fraction of events arising from double-parton interactions, f(DP)((D)), has been measured through the p(T) balance between the two jets and amounts to f(DP)((D)) = 0.08 +/- 0.01 (stat.) +/- 0.02 (sys.) for jets with transverse momentum p(T) > 20 GeV and rapidity vertical bar y vertical bar < 2.8. This corresponds to a measurement of the effective area parameter for hard double-parton interactions of sigma(eff) = 15 +/- 3 (stat.)(-3)(+5) (sys.) mb.
TL;DR: Gonzalez Alvaredo, Facundo as mentioned in this paper, et al. as mentioned in this paper presented an analysis of the relationship between the two types of genes. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina.
Abstract: Fil: Gonzalez Alvaredo, Facundo. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina. University of Oxford; Reino Unido
TL;DR: This work introduces for the first time the concept of an information "container" before a standard optical encrypting procedure which is a QR code which offers the main advantage of being tolerant to pollutant speckle noise.
Abstract: We introduce for the first time the concept of an information “container” before a standard optical encrypting procedure. The “container” selected is a QR code which offers the main advantage of being tolerant to pollutant speckle noise. Besides, the QR code can be read by smartphones, a massively used device. Additionally, QR code includes another secure step to the encrypting benefits the optical methods provide. The QR is generated by means of worldwide free available software. The concept development probes that speckle noise polluting the outcomes of normal optical encrypting procedures can be avoided, then making more attractive the adoption of these techniques. Actual smartphone collected results are shown to validate our proposal.
TL;DR: It is shown that although open-habitat grasses existed in southern South America since the middle Eocene, they were minor floral components in overall forested habitats between 40 and 18 Myr ago, and distinctly different, continent-specific environmental conditions (arid grasslands versus ash-laden forests) triggered convergent cheek-tooth evolution in Cenozoic herbivores.
Abstract: The evolution of high-crowned cheek teeth (hypsodonty) in herbivorous mammals during the late Cenozoic is classically regarded as an adaptive response to the near-global spread of grass-dominated habitats. Precocious hypsodonty in middle Eocene (B38 million years (Myr) ago) faunas from Patagonia, South America, is therefore thought to signal Earth’s first grasslands, 20 million years earlier than elsewhere. Here, using a high-resolution, 43–18 million-year record of plant silica (phytoliths) from Patagonia, we show that although open-habitat grasses existed in southern South America since the middle Eocene (B40 Myr ago), they were minor floral components in overall forested habitats between 40 and 18 Myr ago. Thus, distinctly different, continent-specific environmental conditions (arid grasslands versus ash-laden forests) triggered convergent cheek–tooth evolution in Cenozoic herbivores. Hypsodonty evolution is an important example where the present is an insufficient key to the past, and contextual information from fossils is vital for understanding processes of adaptation.
TL;DR: De Sousa et al. as discussed by the authors presented a study on the use of Fisica La Plata at the Universidad Nacional de la Plata (UniNAC).
Abstract: Fil: de Sousa, Maria Elisa. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata. Instituto de Fisica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Fisica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Fisica; Argentina
TL;DR: In this article, a measurement of the W+W- production cross section in pp collisions at root s = 7 TeV is presented, which is compatible with the Standard Model prediction of 44.7(-1.9)(+2.1) pb.
Abstract: This paper presents a measurement of the W+W- production cross section in pp collisions at root s = 7 TeV. The leptonic decay channels are analyzed using data corresponding to an integrated luminosity of 4: 6 fb(-1) collected with the ATLAS detector at the Large Hadron Collider. The W+W- production cross section sigma(pp -> W+W- + X) is measured to be 51.9 +/- 2.0(stat) +/- 3.9(syst) +/- 2.0(lumi) pb, compatible with the Standard Model prediction of 44.7(-1.9)(+2.1) pb. A measurement of the normalized fiducial cross section as a function of the leading lepton transverse momentum is also presented. The reconstructed transverse momentum distribution of the leading lepton is used to extract limits on anomalous WWZ and WW gamma couplings.
TL;DR: The results indicate that the mycorrhizal inoculation is capable of alleviating the damage caused by salt stress conditions on pepper plants, to maintaining the membranes stability and plant growth, and this could be related to P nutrition.
Abstract: A study was conducted in a greenhouse, to investigate the effects of arbuscular mycorrhizal fungi (Glomus intraradices), soil salinity and P availability on growth (leaf area and dry weight), nutrient absorption and ion leakage, chlorophyll, soluble sugar and proline content and alkaline phosphatase activity of pepper plants (Capsicum annuum L) Plants were grown at four levels of salinity (0, 50, 100 and 200 mM NaCl) and two P levels (10 and 40 mg kg -1 ) Colonisation was 80% to 51% in non-stressed and high salt-stressed plants, respectively The mycorrhizal dependency was high and only reduced at the higher salinity level Mycorrhizal plants maintained greater root and shoot biomass at all salinity levels compared to non-mycorrhizal plants, regardless the P level Interactions between salinity, phosphorous and mycorrhizae were significant for leaf area, root and shoot dry mass Non-mycorrhizal plants accumulated higher Na and lower K and P compared to mycorrhizal plants The cell membrane integrity was greater in mycorrhizal plants than in non-mycorrhizal ones The proline content increases with increasing salt stress and was significantly higher in leaves than in roots The results indicate that the mycorrhizal inoculation is capable of alleviating the damage caused by salt stress conditions on pepper plants, to maintaining the membranes stability and plant growth, and this could be related to P nutrition
TL;DR: In this article, a single sliding mode strategy is proposed to control a bidirectional dc/dc converter, capable of working properly under all operating conditions, which facilitates the implementation and design of the control law and simplifies the stability analysis over the entire operating range.
Abstract: The proper operation of a microgrid requires storage devices that increase the inertia and avoid instability of the system. This paper presents the control of an energy storage system (ESS) based on supercapacitor in the context of grid-connected microgrids. The ESS is composed of AC/DC and DC/DC converters tied by a dc link. A single sliding mode strategy is proposed to control a bidirectional dc/dc converter, capable of working properly under all operating conditions. The switching devices are commanded by a single sliding function, dynamically shaped by references sent from the microgrid central controller. This feature facilitates the implementation and design of the control law and simplifies the stability analysis over the entire operating range. The effectiveness of the proposed control strategy is illustrated by experimental results.
TL;DR: In this paper, the incorporation of sunflower protein films with clove essential oil and the application of the resulting materials on the preservation of sardine patties were studied.
TL;DR: In conclusion, abnormal calving and negative energy balance are associated with increased risk for metritis, especially puerperal meetritis, which correlates with reduced milk production and poor reproductive performance.
TL;DR: The efficiency of chitosan as a corrosion inhibitor for mild steel in 0.1 M HCl was investigated by gravimetric, potentiodynamic polarization, electrochemical impedance spectroscopy measurements, scanning electron microscopy, and UV-visible analysis.
Abstract: The efficiency of chitosan (a naturally occurring polymer) as a corrosion inhibitor for mild steel in 0.1 M HCl was investigated by gravimetric, potentiodynamic polarization, electrochemical impedance spectroscopy measurements, scanning electron microscopy, and UV–visible analysis. The polymer was found to inhibit corrosion even at a very low concentration. Inhibition efficiency increases with a rise in temperature up to 96 % at 60 °C and then drops to 93 % at 70 °C, while it slightly increases with an increase in chitosan concentration. Polarization curves indicate that chitosan functions as a mixed inhibitor, affecting both cathodic and anodic partial reactions. Impedance results indicate that chitosan was adsorbed on the metal/solution interface. Adsorption of chitosan at the mild steel surface is found to be in agreement with Langmuir adsorption isotherm model. Chemical adsorption is the proposed mechanism for corrosion inhibition considering the trend of protection efficiency with temperature. Calculated kinetic and thermodynamic parameters corroborate the proposed mechanism.
TL;DR: Nichela, Daniela Alejandra as discussed by the authors, et al. as discussed by the authors, presented a paper on "Cientifico Tecnologico Patagonia Norte" at the Consejo Nacional de Investigaciones Cientificas and Tecnicas.
TL;DR: The film highlights the challenges and opportunities presented by the continued development of knowledge and technology in the rapidly changing and ever-changing environment.
TL;DR: This review includes the hallmarks of BK channel biophysics and its physiological impact on specific cells and tissues, highlighting its relationship with auxiliary subunit expression.
Abstract: Calcium and voltage-activated potassium (BK) channels are key actors in cell physiology, both in neuronal and non-neuronal cells and tissues. Through negative feedback between intracellular Ca (2+) and membrane voltage, BK channels provide a damping mechanism for excitatory signals. Molecular modulation of these channels by alternative splicing, auxiliary subunits and post-translational modifications showed that these channels are subjected to many mechanisms that add diversity to the BK channel α subunit gene. This complexity of interactions modulates BK channel gating, modifying the energetic barrier of voltage sensor domain activation and channel opening. Regions for voltage as well as Ca (2+) sensitivity have been identified, and the crystal structure generated by the 2 RCK domains contained in the C-terminal of the channel has been described. The linkage of these channels to many intracellular metabolites and pathways, as well as their modulation by extracellular natural agents, has been found to be relevant in many physiological processes. This review includes the hallmarks of BK channel biophysics and its physiological impact on specific cells and tissues, highlighting its relationship with auxiliary subunit expression.
TL;DR: In this paper, a search for the electroweak pair production of charged sleptons and weak gauginos decaying into final states with two leptons was performed using 4.7 fb(-1) of proton-proton collision data at root s = 7 TeV recorded with the ATLAS experiment at the Large Hadron Collider.
TL;DR: The experimental evidence supporting each of the signaling steps leading to the Anrep effect and its blunting is presented by silencing NHE1 expression with a specific small hairpin interference RNA injected into the ventricular wall.
Abstract: Myocardial stretch elicits a rapid increase in developed force, which is mainly caused by an increase in myofilament calcium sensitivity (Frank-Starling mechanism). Over the ensuing 10–15 min, a se...
TL;DR: In this article, Alzua et al. presented a study on the relationship between the distribution of labor and social welfare in the context of economic sciences, and presented the following conclusions:
Abstract: Fil: Alzua, Maria Laura. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Economicas. Departamento de Ciencias Economicas. Centro de Estudios Distributivos Laborales y Sociales; Argentina