Variabilidad 3d de las aguas subterráneas en el Delta del Río Paraná. Argentina

En los sistemas costeros, el asumir simplificaciones de que los flujos se comportan bidimensionalmente, puede llevar a obtener conclusiones que no representen el real funcionamiento del sistema natural. En el caso el Delta del Río Paraná, esta variación temporo-espacial alcanza mayor magnitud. El sistema actúa con características de flujo 3D, con mayor variabilidad en estiajes y/o crecidas prolongadas del Río Paraná, al ser esta la condición de borde temporal que tiene el mayor impacto en el sistema. La superposición de estos efectos, producen limitaciones en la productividad del sistema, por lo que es incapaz de sustentar a una población estable. El objetivo ha sido el de caracterizar el impacto de las aguas subterráneas en el sistema ambiental-productivo del Delta del Río Paraná, su vinculación con las áreas de descarga y sus efectos en la variación en vertical de la salinidad.In coastal systems, the simplifications assume that two-dimensional flows behave can lead to draw co nclusions that do not represent the actual natural system. For the Parana River Delta, the spatial-temporal variation achieves greater magnitude. The system works with 3D flow characteristics, with greater variability in droughts and / or floods prolonged Paraná River, as this is the temporal boundary condition that has the greatest impact on the system. The superposition of these effects, constraints occur in the system productivity, so is unable to sustain a stable population. The aim has been to characterize the impact of groundwater in the environmental system-productive Parana River Delta, its connection with the discharge areas and their effects on the vertical variation in salinity.Universidad Nacional de La Plat

First evidence of coherent K+K^{+} meson production in neutrino-nucleus scattering

Neutrino-induced charged-current coherent kaon production, $\nu_{\mu}A\rightarrow\mu^{-}K^{+}A$, is a rare, inelastic electroweak process that brings a $K^+$ on shell and leaves the target nucleus intact in its ground state. This process is significantly lower in rate than neutrino-induced charged-current coherent pion production, because of Cabibbo suppression and a kinematic suppression due to the larger kaon mass. We search for such events in the scintillator tracker of MINERvA by observing the final state $K^+$, $\mu^-$ and no other detector activity, and by using the kinematics of the final state particles to reconstruct the small momentum transfer to the nucleus, which is a model-independent characteristic of coherent scattering. We find the first experimental evidence for the process at $3\sigma$ significance.Comment: added ancillary file with information about the six kaon candidate

On the nature and impact of self-similarity in real-time systems

In real-time systems with highly variable task execution times simplistic task models are insufficient to accurately model and to analyze the system. Variability can be tackled using distributions rather than a single value, but the proper charac- terization depends on the degree of variability. Self-similarity is one of the deep- est kinds of variability. It characterizes the fact that a workload is not only highly variable, but it is also bursty on many time-scales. This paper identifies in which situations this source of indeterminism can appear in a real-time system: the com- bination of variability in task inter-arrival times and execution times. Although self- similarity is not a claim for all systems with variable execution times, it is not unusual in some applications with real-time requirements, like video processing, networking and gaming. The paper shows how to properly model and to analyze self-similar task sets and how improper modeling can mask deadline misses. The paper derives an analyti- cal expression for the dependence of the deadline miss ratio on the degree of self- similarity and proofs its negative impact on real-time systems performance through system¿s modeling and simulation. This study about the nature and impact of self- similarity on soft real-time systems can help to reduce its effects, to choose the proper scheduling policies, and to avoid its causes at system design time.This work was developed under a grant from the European Union (FRESCOR-FP6/2005/IST/5-03402).Enrique Hernández-Orallo; Vila Carbó, JA. (2012). On the nature and impact of self-similarity in real-time systems. Real-Time Systems. 48(3):294-319. doi:10.1007/s11241-012-9146-0S294319483Abdelzaher TF, Sharma V, Lu C (2004) A utilization bound for aperiodic tasks and priority driven scheduling. IEEE Trans Comput 53(3):334–350Abeni L, Buttazzo G (1999) QoS guarantee using probabilistic deadlines. 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Subjective sleep quality during average volume assured pressure support (AVAPS) ventilation in patients with hypercapnic COPD. A Physiological Pilot Study.

Non-invasive Positive Pressure Ventilation (NPPV) is an advanced treatment (1) aimed to improve both physiological (2-4) and clinical outcomes (5-7), including sleep (8-10), during the long-term management of patients with Chronic Respiratory Failure (CRF) due to severe hypercapnic Chronic Obstructive Pulmonary Disease (COPD). Several studies evaluating the nocturnal application of mask ventilation in stable COPD patients (11-13) have shown a limited effectiveness of pressure based modes of NPPV in this patient group. However, further studies have shown that compliance to ventilation may influence the long-term efficacy of this treatment as patients who are compliant with NPPV are able to maintain arterial blood gase (ABG) improvements over 6-months when compared with those who discontinued this therapy (14).A new NPPV modality, called Average Volume Assured Pressure Support (AVAPS), combines both the pressure and volume characteristics of ventilation and, accordingly, delivers a range of inspiratory pressures to guarantee a pre-fixed inspiratory tidal volume. This hybrid mode of ventilation has been studied in intubated patients with acute respiratory failure (15) and in patients with chronic hypoventilation linked to obesity (16,17) and other conditions (16). Under these circumstances AVAPS is able to induce high pulmonary volumes and reduce muscle workload, thus providing physiological benefits and comfort similar to those achieved by pressure support (PS) modes. However, positive effects on sleep quality have not yet been confirmed.This pilot evaluated short-term compliance, night-time efficacy and physiological responses to Average Volume Assured Pressure Support (AVAPS) ventilation in patients with stable hypercapnic COPD

Matéria orgânica e propriedades físicas de um Argissolo Amarelo Coeso sob sistemas de manejo com cana-de-açúcar Organic matter and physical properties of a Cohesive Yellow Argisol under different management systems with sugar cane

O cultivo contínuo da cana-de-açúcar por longo tempo sob diferentes manejos em solos de tabuleiros costeiros pode causar alterações na matéria orgânica e nas propriedades físicas do solo. Estudaram-se os efeitos de diferentes sistemas de manejo com cana-de-açúcar nas propriedades de um Argissolo Amarelo Coeso, na usina Triunfo, Estado de Alagoas. Os sistemas de manejo consistiram de uma área não irrigada, uma área irrigada, uma com aplicação de vinhaça e outra sob floresta nativa, sob condição original. Amostras foram retiradas de cada área a 0-0,2, 0,2-0,4 e 0,4-0,8 m de profundidade para determinar as alterações nos limites de consistência, parâmetros de compactação, estabilidade de agregados e frações físicas da matéria orgânica do solo. O cultivo da cana-de-açúcar sob os sistemas sequeiro e irrigado promoveu redução mais expressiva no limite de plasticidade, umidade ótima de compactação e diâmetro médio ponderado dos agregados, em relação ao solo sob mata nativa, devido à maior redução nos teores de carbono orgânico total e matéria orgânica particulada do solo. O sistema de manejo com aplicação de vinhaça promoveu menor degradação nas propriedades físicas e químicas do solo, em relação ao solo sob mata nativa.<br>The continuous cultivation of the sugar cane for long-term under different management systems in soils of Coastal Tablelands can cause alterations in the organic matter and in the physical properties of the soil. The effects of different management systems with sugar cane on the properties of a Cohesive Yellow Argisol, in the Triunfo Sugar Cane Mill, in the State of Alagoas, Brazil, were studied. The management systems consisted of an irrigated area, an area not irrigated, an area with vinasse application and an area under native forest in original condition. Samples were collected from each area at 0-0.2, 0.2-0.4 and 0.4-0.8 m depths to determine the modification in the consistence limits, compaction parameters, stability of aggregates and physical fractions of the organic matter of the soil. The results indicated that the cultivation of sugar cane under not irrigated and irrigated systems promoted a more expressive reduction in the plasticity limit, optimum moisture for compaction and aggregate mean weight diameter, in relation to soil under native forest, due to reduction in the contents of total organic carbon and of particulate organic matter. The management system with vinasse application promoted smaller degradation in physical and chemical properties of the soil in relation to soil under native forest