2,124 research outputs found
Nuclear effects in electron reactions and their impact on neutrino processes
We suggest that superscaling in electroweak interactions with nuclei, namely
the observation that the reduced electron-nucleus cross sections are to a large
degree independent of the momentum transfer and of the nuclear species, can be
used as a tool to obtain precise predictions for neutrino-nucleus cross
sections in both charged and neutral current-induced processes.Comment: 11 pages, 7 figures, proceedings of NUINT09, 6th International
Workshop of Neutrino-Nucleus Interactions in the Few-Gev Region, Sitges
(Spain), May 18-22, 200
Neutrino Interactions Importance for Nuclear Physics
We review the general interplay between Nuclear Physics and neutrino-nucleus
cross sections at intermediate and high energies. The effects of different
reaction mechanisms over the neutrino observables are illustrated with examples
in calculations using several nuclear models and ingredients.Comment: To appear in the proceedings of 6th International Workshop on
Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt09), Sitges, Spain,
18 - 22 May 200
Caracterización de diferentes compost para su uso como componente de sustratos
Actualmente el uso de sustrato se ha incrementado en varios sectores agrícolas. Entre los materiales empleados para su formulación se encuentran los compost, y como todo componente es importante conocer sus propiedades previo a su uso. El objetivo de este trabajo fue caracterizar 15 compost de diferentes orígenes, para evaluarlos como componente de sustrato. Se analizaron los siguientes parámetros: densidad aparente, espacio poroso total, capacidad de retención de agua (CRA), porosidad de aireación (PA), granulometría, pH, conductividad eléctrica (CE), concentración de calcio, magnesio, potasio, sodio y nitratos. Hubo diferencias significativas (P < 0,05) entre los compost para todas las variables analizadas. La densidad aparente fue mayor en el compost de ave de corral. El compost de corteza de pino gruesa tuvo el mayor porcentaje de PA y el compost de residuos de poda el mayor porcentaje de CRA. Los compost de corteza de pino podrían ser componentes que aportarían aireación en una formulación de sustrato. Los valores de pH obtenidos se encontraron entre 4,7 a 8,7 y de CE entre 0,09 a 5,55 dS m-1. La mayoría de los compost superaron el rango adecuado de pH (5,5-6,3) y si bien la mayoría no tuvieron una CE elevada, hubo algunos como el compost de ave de corral, de residuos sólidos urbanos y de residuos porcinos que superaron 1 dS m-1, y podrían causar efectos nocivos en las plantas. Todos los compost son viables para su uso teniendo en cuenta sus propiedades y las condiciones del cultivo en que se va a utilizar el sustrato formulado.The use of substrates in agriculture has increased in recent years. Compost is one of the materials used in substrate formulation, and therefore, it is important to know its properties prior to its use. The objective of this study was to characterize 15 different types of compost from different sources in order to evaluate them as substrate components. The following parameters were determined: bulk density, total pore space, water retention capacity (Cra), aeration porosity (Pa), granulometry, pH, electrical conductivity (EC), and concentrations of calcium, magnesium, potassium, sodium and nitrates. There were significant differences (P < 0.0001) among the compost for all the variables analyzed. Poultry compost had the highest bulk density. Thick pine bark compost had the highest percentage of Pa, while pruning waste compost recorded the highest percentage of Cra . Pine bark compost could increase aeration in a substrate formulation. The pH values obtained ranged from 4.7 to 8.7, while CE values varied between 0.09 and 5.55 dS m-1. Most of the compost exceeded an optimal pH range (5.5-6.3). On the contrary, most compost did not reach high EC values. However, some types of compost, such as those from poultry, urban solid waste and pig waste, exceeded 1 dS m-1, and could cause harmful effects on plants. All types of compost are viable for use provided both compost properties and crop conditions are considered to decide which substrate to use.EEA Cerro AzulFil: Barbaro, Lorena Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Cerro Azul; ArgentinaFil: Karlanian, Monica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Rizzo, Pedro Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Riera, Nicolas Iván. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentin
Evaluation of compost of swine waste as amendment for production of cut wallflowers (Matthiolaincana)
The intensification of swine production systems generates accumulation of manure, which if not stabilized can generate negative impact on the environment. At the same time, the demand for organic materials to amend the soil for the production of cut flowers has increased. The objective of the work was to evaluate the use of swine compost as an amendment in different proportions through the growth of wallflowers
(Matthiolaincana). The trial consisted of four treatments with three repetitions each: T1: 15l/m2 , T2: 30l/m2 , T3: 60 l/m2 and T4: no incorporation of compost. A 12m x 1m flowerbed was used, divided into 12 experimental units. Phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), nitrates (NO3 - ), pH and electrical
conductivity (EC) in a ratio of 1 / 5 (v/v sample / water), and organic matter (OM) were analyzed for each
treatment. In addition compost quality and the presence of Escherichia coli and Salmonella spp. were also analyzed. The carbon / nitrogen (C / N) ratio of the compost was 14.1 and the respirometric index (IRE) of 0.55 mg O2 g -1 MO h-1 According to the TMECC (2001)[1], these values establish that the compost was stable and mature, on the other hand, the absence of pathogens E. coli and Salmonella ssp. was verified. The high electrical conductivity (CE) (5.53 dS.m-1 ) and the high concentration of sodium (11464 mg/l) in the compost were limiting for the development of wallflower (wallflower plant). The amendment with doses superior to 30 l/m 2 , caused a reduction of the growth and consequently lower quality of the floral stick. The evaluated swine compost is viable as an amendment to produce cut wallflowers up to 15l/m2.Inst. de Microbiología y Zoología Agrícola IMyZAFil: Riera, Nicolas Iván. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Barbaro, Lorena Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Karlanian, Monica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Beily, María Eugenia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Rizzo, Pedro Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Crespo, Diana Elvira. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Giuffré, Lidia. Universidad de Buenos Aires. Facultad de Agronomía, Departamento de Recursos Naturales, Medio Ambiente. Cátedra de Edafología; Argentin
Fast Liquid Chromatography Coupled with Tandem Mass Spectrometry for the Analysis of Vanillic and Syringic Acids in Ice Cores
The development of new analytical systems and the improvement of the existing ones to obtain high-resolution measurements of chemical markers in samples from ice cores, is one of the main challenges the paleoclimatic scientific community is facing. Different chemical species can be used as markers for tracking emission sources or specific environmental processes. Although some markers, such as methane sulfonic acid (a proxy of marine productivity), are commonly used, there is a lack of data on other organic tracers in ice cores, making their continuous analysis analytically challenging. Here, we present an innovative combination of fast liquid chromatography coupled with tandem mass spectrometry (FLC-MS/MS) to continuously determine organic markers in ice cores. After specific optimization, this approach was applied to the quantification of vanillic and syringic acids, two specific markers for biomass burning. Using the validated method, detection limits of 3.6 and 4.6 pg mL–1 for vanillic and syringic acids, respectively, were achieved. Thanks to the coupling of FLC-MS/MS with the continuous flow analytical system, we obtained one measurement every 30 s, which corresponds to a sampling resolution of a sample every 1.5 cm with a melting rate of 3.0 cm min–1. To check the robustness of the method, we analyzed two parallel sticks of an alpine ice core over more than 5 h. Vanillic acid was found with concentrations in the range of picograms per milliliter, suggesting the combustion of coniferous trees, which are found throughout the Italian Alps.publishedVersio
The seasonal change of PAHs in Svalbard surface snow
The Arctic region is threatened by contamination deriving from both long-range pollution and local human activities. Polycyclic Aromatic Hydrocarbons (PAHs) are environmental tracers of emission, transport and deposition processes. A first campaign has been conducted at Ny-Ålesund, Svalbard, from October 2018 to May 2019, monitoring weekly concentrations of PAHs in Arctic surface snow. The trend of the 16 high priority PAH compounds showed that long-range inputs occurred mainly in the winter, with concentrations ranging from 0.8 ng L−1 to 37 ng L−1. In contrast to this, the most abundant analyte retene, showed an opposite seasonal trend with highest values in autumn and late spring (up to 97 ng L−1), while in winter this compound remained below 3 ng L−1. This is most likely due to local contributions from outcropping coal deposits and stockpiles. Our results show a general agreement with the atmospheric signal, although significant skews can be attributed to post-depositional processes, wind erosion, melting episodes and redistribution
Climate change is rapidly deteriorating the climatic signal in Svalbard glaciers
The Svalbard archipelago is particularly sensitive to climate change due to the relatively low altitude of its main ice fields and its geographical location in the higher North Atlantic, where the effect of Arctic amplification is more significant. The largest temperature increases have been observed during winter, but increasing summer temperatures, above the melting point, have led to increased glacier melt. Here, we evaluate the impact of this increased melt on the preservation of the oxygen isotope (δ18O) signal in firn records. δ18O is commonly used as a proxy for past atmospheric temperature reconstructions, and, when preserved, it is a crucial parameter to date and align ice cores. By comparing four different firn cores collected in 2012, 2015, 2017 and 2019 at the top of the Holtedahlfonna ice field (1100 m a.s.l.), we show a progressive deterioration of the isotope signal, and we link its degradation to the increased occurrence and intensity of melt events. Our findings indicate that, starting from 2015, there has been an escalation in melting and percolation resulting from changes in the overall atmospheric conditions. This has led to the deterioration of the climate signal preserved within the firn or ice. Our observations correspond with the model's calculations, demonstrating an increase in water percolation since 2014, potentially reaching deeper layers of the firn. Although the δ18O signal still reflects the interannual temperature trend, more frequent melting events may in the future affect the interpretation of the isotopic signal, compromising the use of Svalbard ice cores. Our findings highlight the impact and the speed at which Arctic amplification is affecting Svalbard's cryosphere.</p
Compost de guano de gallina en la composición de sustratos para la producción de plantines florales
Se evaluaron sustratos formulados con distintas proporciones (20, 50 y 80%) de tres tipos de compost de guano de gallina (CGG1, CGG2, CGG3) mezclados con compost de corteza de pino y un sustrato comercial. Los diez tratamientos fueron usados para el cultivo de plantines de Impatiens walleriana y Salviasplendens. Se caracterizó física y químicamente cada sustrato, y sobre los plantines se evaluó sobrevivencia, masa seca y calcio, magnesio, potasio y sodio en la hoja. Los sustratos con 20% y 50% de los tres CGG tuvieron la mayor capacidad de retención de agua, y con 80%, la mayor porosidad de aire. Los sustratos con 50% y 80% presentaron los más altos valores de pH (≥6,6), potasio y sodio. Para las mismas proporciones, CGG2 y CGG3 presentaron valores de CE >1,1 dS cm-1. La mayor masa seca de los plantines se logró para el sustrato comercial, los sustratos con 20% de los tres CGG y con 50% de CGG1. Estos sustratos exhibieron en las hojas una mayor concentración de calcio y magnesio, y menor de potasio. Las mejores características de sustratos para el desarrollo de los plantines evaluados se lograron en los sustratos con 20% de los tres CGG y con 50% del compost CGG1.Substrates formulated with different proportions (20, 50 and 80%) of three types of poultry compost (CGG1, CGG2, CGG3) mixed with pine bark compost and commercial substrate were evaluated. The ten treatments were used to cultivate seedlings of walleriana Impatiens and Salvia splendens. Each substrate was characterised physically and chemically, and the survival, dry mass and calcium, magnesium, potassium and sodium in the leaf were evaluated in seedlings. Substrates with 20% and 50% among the three CGG presented the highest water retention capacity and, with 80% the highest air porosity. The substrates with 50% and 80% showed the highest values of pH (≥ 6.6), potassium and sodium. For the same proportions, CGG2 and CGG3 presented CE values > 1.1 dS cm-1. The highest dry weight of the seedlings was achieved with the commercial substrate, the substrates with 20% of the three CGG and with 50% of CGG1. These substrates showed a higher concentration of calcium and magnesium, and a lower concentration of potassium in the leaves. The best characteristics of substrates for the development of the seedlings tested were achieved in the substrates with 20% of the three CGG and with 50% of compost CGG1.Fil: Barbaro, Lorena Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Karlanian, Monica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Rizzo, Pedro Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto
de Microbiología y Zoología Agrícola; ArgentinaFil: Riera, Nicolas Iván. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto
de Microbiología y Zoología Agrícola; ArgentinaFil: Della Torre, Virginia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto
de Microbiología y Zoología Agrícola; ArgentinaFil: Beltran, Marcelo Javier. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto
de Suelos; ArgentinaFil: Crespo, Diana Elvira. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto
de Microbiología y Zoología Agrícola; Argentin
Advanced liver disease outcomes after hepatitis C eradication by human immunodeficiency virus infection in PITER cohort
Liver disease progression after Hepatitis C Virus (HCV) eradication following direct-acting antiviral (DAA) treatment in the real-life setting according to Human Immunodeficiency Virus (HIV) coinfection was evaluated
Assessment of the dynamics of atrial signals and local atrial period series during atrial fibrillation: effects of isoproterenol administration
BACKGROUND: The autonomic nervous system (ANS) plays an important role in the genesis and maintenance of atrial fibrillation (AF), but quantification of its electrophysiologic effects is extremely complex and difficult. Aim of the study was to evaluate the capability of linear and non-linear indexes to capture the fine changing dynamics of atrial signals and local atrial period (LAP) series during adrenergic activation induced by isoproterenol (a sympathomimetic drug) infusion. METHODS: Nine patients with paroxysmal or persistent AF (aged 60 ± 6) underwent electrophysiological study in which isoproterenol was administered to patients. Atrial electrograms were acquired during i) sinus rhythm (SR); ii) sinus rhythm during isoproterenol (SRISO) administration; iii) atrial fibrillation (AF) and iv) atrial fibrillation during isoproterenol (AFISO) administration. The level of organization between two electrograms was assessed by the synchronization index (S), whereas the degree of recurrence of a pattern in a signal was defined by the regularity index (R). In addition, the level of predictability (LP) and regularity of LAP series were computed. RESULTS: LAP series analysis shows a reduction of both LP and R index during isoproterenol infusion in SR and AF (R(SR )= 0.75 ± 0.07 R(SRISO )= 0.69 ± 0.10, p < 0.0001; R(AF )= 0.31 ± 0.08 R(AFISO )= 0.26 ± 0.09, p < 0.0001; LP(SR )= 99.99 ± 0.001 LP(SRISO )= 99.97 ± 0.03, p < 0.0001; LP(AF )= 69.46 ± 21.55 LP(AFISO )= 55 ± 24.75; p < 0.0001). Electrograms analysis shows R index reductions both in SR (R(SR )= 0.49 ± 0.08 R(SRISO )= 0.46 ± 0.09 p < 0.0001) and in AF (R(AF )= 0.29 ± 0.09 R(AFISO )= 0.28 ± 0.08 n.s.). CONCLUSIONS: The proposed parameters succeeded in discriminating the subtle changes due to isoproterenol infusion during both the rhythms especially when considering LAP series analysis. The reduced value of analyzed parameters after isoproterenol administration could reflect an important pro-arrhythmic influence of adrenergic activation on favoring maintenance of AF
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