Variabilidad cada seis horas de la temperatura de superficie

En este trabajo se estudia el comportamiento del cambio de la temperatura cada seis horas en una estación ubicada en la periferia de la ciudad de Buenos Aires. Ese cambio se representa con la "diferencia" de temperatura en seis horas. Se observa mayor cantidad de calentamientos que de enfriamientos pero de menor intensidad. Todas las distribuciones presentan una leve asimetría. Estas "diferencias" pertenecen a ondas de período muy corto, lo que muestra que estos procesos se debilitan rápidamente. En el análisis de valores extremos absolutos, se nota que su ocurrencia tiene horas preferenciales, a pesar de estar filtradas las ondas astronómicas. Es en el intervalo entre las 08 y las 14 donde se producen los mayores calentamientos y enfriamientos.The behavior of the temperature change each six hours, in a station near the city of Buenos Aires is studied. This change is explained by the difference between 6-hourly temporatures. The distributions are slightly assimetric because there are more heatings than coolings but less intense. It can be seen that those "differences" belong to short waves. They show that the processes weaken quickly. A preferent interval occured in the absolute extrem values analysis, in spite of the astronomics waves have been filtered. The mayor heatings and coolings are produced between 08:00 and 14:00.Asociación Argentina de Geofísicos y Geodesta

Efecto de la ciudad y el rio sobre la temperatura de superficie en Buenos Aires

El objetivo de este trabajo es estudiar algunas estructuras climáticas de la temperatura y las perturbaciones provocadas por la ubicación de las estaciones. Se toman tres estaciones en las inmediaciones y dentro de la ciudad de Buenos Aires. y se analizan las temperaturas de las horas 02:00, 08:00, 14:00 y 20:00. Se muestra que la influencia de la dirección del viento en la manifestación de los efectos de la ciudad o el río en la temperatura, depende de la hora y de la época del año. Sin embargo la estación de referencia no está influenciada por la ciudad, en la mayoría de las veces. El efecto de la ciudad sobre los promedios de temperatura, es máximo en horas de la noche. La influyencia del río, en cambio, es más notable a las 14:00. Ambos efectos se reflejan sobre la distribución de las anomalías de las estaciones estudiadas. Los procesos que dominan estas series son más homogéneos entre estaciones, si se consideran las temperaturas diarias.The alm of this paper is to study the effect of the station location on the six-hourly temperatures climatic structures. The observed temperature (at 02:00. 08:00, 14:00, 20:00, local time), for three stations within the metropolitan area of Buenos Aires, is studied. Local influences depend on the day time and the season. In the analysis of the wind direction, in most oí the situations the reference station is not influenced by the city. The urban effect is maximum al night hours and the river influence is maximum at 14:00. Both effects are still present in the anomalies frequency distribution. The daily anomalies processes are more homogeneous than the six-hourly ones between stations.Asociación Argentina de Geofísicos y Geodesta

Propiedades y procesos dominantes de una serie cuatridiurna de temperatura

Se estudia la serie de temperaturas cuatridiurnas (hora 02, 08 14 y 20), de la estación Ezeiza (34° 49'S, 59° 32'W) en el período 1968-1980, con el objetivo final de obtener un diagnóstico que pueda servir a posteriori para el ajuste de un modelo de pronóstico para la serie. Se investiga el grado de variabilidad o contribución a la serie que introducen los meses, las horas y los años. Los procesos estadísticos dominantes en las series, sean estas cuatridiurnas o diarias, son esencialmente Markovianos, según lo detecta la estimación de las funciones de autocorrelación y espectros de poder. Como se postula que la serie filtrada cuatridiurna puede describirse mediante un mismo proceso, se estudia el espectro hora a hora con el objeto de medir la homogeneidad. Se encuentra que las causas de inhomogeneidad serían provocadas por ondas mayores que 14 días. En función de todas las propiedades que la serie presenta, es factible suponer que un modelo autorregresivo puede ser ajustado con fines de diagnóstico y pronóstico.The series of quartan temperatures of the station Ezeiza (34° 49'S, 59° 32'W) in the period 1968-1980 is being studied, with the final aim to obtain a diagnostic model for the series. The degree of variability or contribution to the series introduced by months, hours and years is being investigated. The statistic processes dominant in the series, be these quartan or daily, are essentially Markovian, according is being revealed by the estimation of the functions of autocorrelation and power spectra. As it is being postulated that the filtered quartan series can be described by means of the same process, the spectrum is being studied hour by hour with the aim to measure homogeneity. It is found that the un-homogeneity is caused by waves longer than a fortnigth. Based on the properties of the series, it is possible to assume that an autorregressive model can be adjusted for diagnostic and forecasting purposes.Asociación Argentina de Geofísicos y Geodesta

Estructura del régimen de precipitación de la ciudad de Buenos Aires

Los objetivos fundamentales hacia los que apunta este trabajo son: sintetizar el régimen anual y el estacional de la lluvia en Buenos Aires y relacionarlos en otras investigaciones futuras, con los correspondientes regímenes de otras variables (presión, humedad). Se supone que tanto la lluvia mensual como la anual de Buenos Aires (34° 35'S, 58° 29'W) están representadas por la serie de precipitación mensual del Observatorio Central en cuanto á algunas propiedades de interés climático. Mediante las características del espectro de Fourier se discriminan los posibles grupos o tipos de marchas anuales. Se analiza la eficacia de distintos filtros de la onda anual. Los resultados muestran que las series de lluvias mensuales de cada año se pueden agrupar por medio del armónico que explica la mayor varianza. No obstante, al aumentar las discriminaciones incluyendo el segundo armónico en orden de importancia respecto a la varianza explicada, se manifiestan signos de sobreclasificación. Se encuentra que las diferentes componentes de los grupos no están asociadas a características de la lluvia anual, tales como ocurrencia de años máximos o mínimos. Esto implicaría que el tipo de lluvia en el año, no puede ser identificado con los espectros de Fourier aplicados a la serie de lluvias mensuales o que la variabilidad de esta estructura hace que la probabilidad de repetición de una marcha anual (filtrada la onda anual) sea baja.The main objectives toward which this paper is directed are: to define a synthesis of the annual and seasonal regimes of rainfall in Buenos Aires and to relate it a posteriori with the corresponding in other variables (pressure, humidity). It is assumed that mensual and annual rainfalls in Buenos Aires (34° 35' S, 589 29'W) are represented by a series of the Central Observatory in matter of some structures of climatologic interest. Possible groups or types of annual variation discriminated by means of their Fourier spectrum characteristics in a 123 years period were investigated. Furthermore, the influence and efficiency of distinct filters of the annual cycle were analyzed. The results show that monthly series of each year may be grouped by means of the harmonic which explains the greatest variance. Notwithstanding, when increasing discriminations, by including the second harmonic in order of importance with respect to the explained variance, signs of overclassification are perceived. The different structures implied by the groups are not associated by particular characteristics of the annual rainfall, such as ocurrence of maximum and minumum years. This would imply that the type of year according to its annual total cannot be discriminated with Fourier spectra or that the variability of this structure determines that the probability of the repetition of an annual variation, filtered the annual cycle, is low.Asociación Argentina de Geofísicos y Geodesta

A Fungal Effector With Host Nuclear Localization and DNA-Binding Properties Is Required for Maize Anthracnose Development

Plant pathogens have the capacity to manipulate the host immune system through the secretion of effectors. We identified 27 putative effector proteins encoded in the genome of the maize anthracnose pathogen Colletotrichum graminicola that are likely to target the host’s nucleus, as they simultaneously contain sequence signatures for secretion and nuclear localization. We functionally characterized one protein, identified as CgEP1. This protein is synthesized during the early stages of disease development and is necessary for anthracnose development in maize leaves, stems, and roots. Genetic, molecular, and biochemical studies confirmed that this effector targets the host’s nucleus and defines a novel class of double-stranded DNA-binding protein. We show that CgEP1 arose from a gene duplication in an ancestor of a lineage of monocot-infecting Colletotrichum spp. and has undergone an intense evolution process, with evidence for episodes of positive selection. We detected CgEP1 homologs in several species of a grass-infecting lineage of Colletotrichum spp., suggesting that its function may be conserved across a large number of anthracnose pathogens. Our results demonstrate that effectors targeted to the host nucleus may be key elements for disease development and aid in the understanding of the genetic basis of anthracnose development in maize plants.Fil: Vargas, Walter Alberto. Universidad de Salamanca; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sanz Martín, José M.. Universidad de Salamanca; EspañaFil: Rech, Gabriel E.. Universidad de Salamanca; EspañaFil: Armijos Jaramillo, Vinicio D.. Universidad de Salamanca; EspañaFil: Rivera Rodriguez, Lina Patricia. Universidad de Salamanca; EspañaFil: Echeverria, María de Las Mercedes. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Díaz Mínguez, José M.. Universidad de Salamanca; EspañaFil: Thon, Michael R.. Universidad de Salamanca; EspañaFil: Sukno, Serenella A.. Universidad de Salamanca; Españ

Role of gliotoxin in the symbiotic and pathogenic interactions of Trichoderma virens

Using a gene disruption strategy, we generated mutants in the gliP locus of the plant-beneficial fungus Trichoderma virens that were no longer capable of producing gliotoxin. Phenotypic assays demonstrated that the gliP-disrupted mutants grew faster, were more sensitive to oxidative stress and exhibited a sparse colony edge compared with the WT strain. In a plate confrontation assay, the mutants deficient in gliotoxin production were ineffective as mycoparasites against the oomycete, Pythium ultimum, and the necrotrophic fungal pathogen, Sclerotinia sclerotiorum, but retained mycoparasitic ability against Rhizoctonia solani. Biocontrol assays in soil showed that the mutants were incapable of protecting cotton seedlings from attack by P. ultimum, against which the WT strain was highly effective. The mutants, however, were as effective as the WT strain in protecting cotton seedlings against R. solani. Loss of gliotoxin production also resulted in a reduced ability of the mutants to attack the sclerotia of S. sclerotiorum compared with the WT. The addition of exogenous gliotoxin to the sclerotia colonized by the mutants partially restored their degradative abilities. Interestingly, as in Aspergillus fumigatus, an opportunistic human pathogen, gliotoxin was found to be involved in pathogenicity of T. virens against larvae of the wax moth, Galleria mellonella. The loss of gliotoxin production in T. virens was restored by complementation with the gliP gene from A. fumigatus. We have, thus, demonstrated that the putative gliP cluster of T. virens is responsible for the biosynthesis of gliotoxin, and gliotoxin is involved in mycoparasitism and biocontrol properties of this plant-beneficial fungusFil: Vargas, Walter Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); ArgentinaFil: Mukherjee, Prasun K.. Bhabha Atomic Research Centre; IndiaFil: Laughlin, David. Texas A&M University; Estados UnidosFil: Wiest, Aric. University Of Missouri; Estados UnidosFil: Moran Diez, Maria E.. Texas A&M University; Estados UnidosFil: Kenerley, Charles M.. Texas A; Estados Unido

Informe de actividades primer semestre de 1996 :Creced Arauca

Para cualquiera que sea el sistema de producción agrícola la calidad de la semilla es el factor determinante del éxito o el fracaso. En los sistemas de economía campesina generalmente la semilla para siembra proviene de un cosecha anterior, obviamente el proceso de selección por parte del campesino, esta lleno de conocimientos ancestrales y de experiencias cotidianas que le permiten al productor conocer cierta calidad agronómica y botánica del cultivo, Sin embargo también desconoce algunos aspectos técnicos de selección y especialmente de conservación de semilla que se reflejan en la disminución de la calidad

Ensayo de un pronóstico numérico para la Argentina

La aplicación del pronóstico numérico en la Argentina encuentra el problema de los datos básicos para el análisis del estado inicial. En este trabajo se realiza un ensayo basado en el análisis de los datos convencionales y en las imágenes de los campos nubosos proporcionados por la Estación Receptora APT en Ezeiza. Para ello se ha empleado un modelo baroclínico de dos capas y se ha extendido el pronóstico hasta un término de 24 horas. El resultado muestra que, aun con los datos disponibles en este momento, es posible encarar el pronóstico numérico.Numerical forecasting in Argentina has to deal with the problem of availability of observational data for the analysis. In this paper we describe a test based on the analysis of the conventional data as well as on the cloud patterns received by the APT — Station of Ezeiza. For this purpose we applied a two layer baroclinic model and extended the forecast for a period of 24 hours. The result indicates that with the data currently available it is possible to employ numerical methods for routine forecasting.Asociación Argentina de Geofísicos y Geodesta

Use of Wastewater and Electrogenic Bacteria to Generate Eco-Friendly Electricity through Microbial Fuel Cells

Power generation and wastewater treatment are two great challenges for sustainable development. Microbial fuel cells (MFCs) are a sustainable alternative that can generate bioelectricity in the bioremediation process of wastewater. For this reason, the objective of this research was to generate bioelectricity through double-chamber microbial-combustion cell systems from wastewater from the Covicorti Wastewater Treatment Plant (PTARC) in the anodic chamber and electrogenic bacteria such as Stenotrophomonas maltophilia, Acinetobacter bereziniae, and Achromobacteria xylosoxidans in the cathode chamber, respectively. Measurements of the voltage, current, power density, current density, and optical density of the bacteria and biochemical oxygen demand (BOD) were made. In addition, a metagenomic analysis of the wastewater sample was performed. It was shown that the MFC with A. xylosoxidans generated the highest voltage peak (1.01 ± 0.06 V) on day 24, while the MFC with S. maltophilia generated the highest current value (0.71 ± 0.02 mA). The pH levels were slightly alkaline, and the maximum anodic conductivity value was presented by the MFC with A. cerevisiae, with a peak value of 81 ± 2 mS/cm on day 24. On the other hand, a maximum power density and current density of 195,493 ± 4717 mW/m2 and 4987 A/cm2, respectively, were obtained in the MFC with A. xylosoxidans. Finally, the metagenomic analysis identified the predominant phyla of Proteobacteria present in wastewater samples capable of generating electrical energy as Bacillota, Pseudomonadota, Bacteroidota, Actinomyketone, and Campylobacterota

Milder Alzheimer\u27s Disease Pathology in Heart Failure and Atrial Fibrillation

Introduction:Heart failure (HF) and atrial fibrillation (AF) have been associated with a higher risk of Alzheimer’s disease (AD). Whether HF and AF are related to AD by enhancing AD neuropathological changes is unknown. Methods:We applied network analyses and multiple logistic regression models to assess the association between HF and AF with severity of AD neuropathology in patients from the National Alzheimer’s Coordinating Center database with primary neuropathological diagnosis of AD. Results:We included 1593 patients, of whom 129 had HF and 250 had AF. HF and AF patients were older and had milder AD pathology. In the network analyses, HF and AF were associated with milder AD neuropathology. In the regression analyses, age (odds ratio [OR] 0.94, 95