613 research outputs found

    Spring Forage Stash Module to Prevent Forage Crisis on Uruguayan Livestock Systems: An Evaluation Based on Model Simulations

    Get PDF
    In Uruguay, rangeland cattle production systems support national economy by beef exportation chain and economic inputs to the country. Soil hydric stress episodes results to forage crisis on grassland-based production systems, having high impact on its trajectory and leaving sequels at several farm levels mainly on rearing cattle systems in drought sensitive regions of the country. In that context, the proposal is to create a spring forage stash module, with a simple management rules as a mechanism to build stability to farms and to buffering drought impact. The concept is to differ spring forage (season with low variation coefficient on net primary production) to summer (season with high variation and susceptible to drought stress episodes). This forage stash module is actually started to be implemented in some monitored farms nevertheless, the use of simulation models can project some concrete result generating future possible evolutions for the system. A predator-prey model for extensive livestock systems -called PPGL- was set to understand the impact of that spring forage stash module on animal securing parameter, expressed as the proportion of adult rearing cows maintaining liveweight at summer grazing on a drought scenario. Results suggest that the stashing 10% of the farm surface can save approximatively 70% of rearing cows, even for drought episodes on closing time or in the summer grazing period. Additionally, a linear direct effect was observed between stashing surface on proportion of rearing cows secured. The resulting carrying capacity of the stash forage module is about 800 to 850 kg liveweight / ha on the grazing period, supporting high grazing pressure. Considering those results, the inclusion of a spring forage stash module is a promising tool to generate more resilient livestock production systems

    A new 130nm F.E readout chip for microstrip detectors

    Full text link
    In the context of the Silicon tracking for a Linear Collider (SiLC) R&D collaboration, a highly compact mixed-signal chip has been designed in 130nm CMOS technology intended to read Silicon strip detectors for the experiments at the future International Linear Collider. The chip includes eighty eight channels of a full analog signal processing chain and analog to digital conversion with the corresponding digital controls and readout channels. The chip is 5x10mm2 where the analog implementation represents 4/5 of the total Silicon area.Comment: 3 pages, 4 figures, LCWS08 worksho

    Recurso. Modelo de crecimiento de árbol individual para plantaciones de pino radiata en el noroeste de España

    Get PDF
    Individual-tree basal area and height increment models were developed with data from 130 permanent plots of Pinus radiata D. Don located in Galicia (northwestern Spain). Mixed-models techniques were used for model fitting. Covariates acting at tree and stand level were included as fixed effects. Estimated values of stand variables obtained from aggregation of individual-tree predictions were used in model evaluation. The developed models accounted for 54% of the variability in basal area increment and 36% of the variability in height increment, with mean errors of 16 cm2 and 0.36 m, respectively. These models, along with an existing individual-tree mortality model, constitute a whole individual-tree growth model that can be used to simulate forest management alternatives, helping in forest managers’ decision making.En este estudio se han desarrollado modelos de incremento en sección normal y altura de árbol individual, utilizando datos de 130 parcelas de Pinus radiata D. Don localizadas en Galicia. La técnica de modelos mixtos se utilizó en el ajuste de los modelos. Se incluyeron covariables que actúan a nivel de árbol y a nivel de rodal como efectos fijos en los modelos. En la evaluación de los modelos se utilizaron estimaciones de variables de rodal obtenidas por agregación de las predicciones de árbol individual. Los modelos desarrollados explicaron el 54% de la variabilidad en el incremento en sección normal y el 36% de la variabilidad en el incremento en altura, con errores medios de 16 cm2 y 0.36 m, respectivamente. Estos modelos, junto al modelo de mortalidad de árbol individual existente, forman un modelo de crecimiento de árbol individual que puede utilizarse para simular alternativas de gestión forestal, ayudando a la toma de decisiones de los gestores forestales

    Experimental investigation of a quantum heat engine powered by generalized measurements

    Full text link
    Generalized measurements may allow the control of its invasiveness on the quantum system interpolating from a very weak to strong projective action. Such a measurement can fuel a quantum heat engine or extract work depending on the system-meter interaction. Here, we performed a proof-of-concept experiment using Nuclear Magnetic Resonance techniques to investigate a spin quantum heat engine driven by non-selective generalized (weak) measurements without feedback control. Our prototype of a quantum thermal device operates with a measurement protocol and a single heat bath. The protocol is composed of two non-selective measurement channels with variable measurement strengths, one dedicated to fueling the device (analogous to a hot heat source) and the other committed to work extraction. The experimental results highlight that this kind of quantum thermal device can reach unit efficiency with maximum extracted power by fine-tuning of the measurement strengths.Comment: 8 pages, 6 figure

    A new player in cartilage homeostasis: adiponectin induces nitric oxide synthase type II and pro-inflammatory cytokines in chondrocytes

    Get PDF
    SummaryObjectiveRecent studies revealed a close connection between adipose tissue, adipokines and articular degenerative inflammatory diseases such as rheumatoid arthritis (RA) and osteoarthritis (OA). The goal of this work was to investigate the activity of adiponectin in human and murine chondrocytes and to study its functional role in the modulation of nitric oxide synthase type II (NOS2). For completeness, interleukin (IL)-6, IL-1β, matrix metalloproteinase (MMP)-2, MMP-3, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1, prostaglandin E2 (PGE2), leukotriene B4 (LTB4), tumor necrosis factor alpha (TNF)-α and monocyte chemoattractant protein-1 (MCP-1) accumulation have been evaluated in adiponectin-stimulated chondrocytes cell culture supernatants.MethodsMurine ATDC5 cell line, C28/I2, C20A4, TC28a2 human immortalized chondrocytes, and human cultured chondrocytes were used. Nitrite accumulation was determined by Griess reaction. Adiponectin receptors (AdipoRs) expression was evaluated by immunofluorescence microscopy and confirmed by reverse transcriptase-polymerase chain reaction. NOS2 expression was evaluated by Western blot analysis whereas cytokines, prostanoids and metalloproteinases production was evaluated by specific enzyme-linked immunosorbent assays.ResultsHuman and murine chondrocytes express functional AdipoRs. Adiponectin induces NOS2. This effect is inhibited by aminoguanidine, dexamethasone and by a selective inhibitor of phosphatidylinositol 3-kinase. In addition, adiponectin is able to increase IL-6, MMP-3, MMP-9 and MCP-1 by murine cultured chondrocytes whereas it was unable to modulate TNF-α, IL-1β, MMP-2, TIMP-1, PGE2 and LTB4 release.ConclusionsThese results bind more closely the interactions between fat-derived adipokines and articular inflammatory diseases, and suggest that adiponectin is a novel key element in the maintenance of cartilage homeostasis which might be considered as a potential therapeutical target in joint degenerative diseases

    Foreign Body Aspiration Presenting with Asthma-Like Symptoms

    Get PDF
    Aspiration of a foreign body into the tracheobronchial tree is rare in adults. In the majority of these cases there is an underlying condition such as mental retardation, depressed mental status, impairment in the swallowing reflex, neurological impairment, alcohol or sedative abuse, or complications from dental manipulations that contributed to the aspiration. These patients are commonly misdiagnosed with asthma and typically do not respond to mainstay anti-inflammatory and/or bronchodilator therapy. We describe the case of a patient with a foreign body aspiration in the upper trachea not recognized by radiographic studies that presented with asthma-type symptoms

    Foreign body aspiration presenting with asthma-like symptoms

    Get PDF
    Aspiration of a foreign body into the tracheobronchial tree is rare in adults. In the majority of these cases there is an underlying condition such as mental retardation, depressed mental status, impairment in the swallowing reflex, neurological impairment, alcohol or sedative abuse, or complications from dental manipulations that contributed to the aspiration. These patients are commonly misdiagnosed with asthma and typically do not respond to mainstay anti-inflammatory and/or bronchodilator therapy. We describe the case of a patient with a foreign body aspiration in the upper trachea not recognized by radiographic studies that presented with asthma-type symptoms

    Resistin Regulates Pituitary Lipid Metabolism and Inflammation In Vivo

    Get PDF
    The adipokine resistin is an insulin-antagonizing factor that also plays a regulatory role in inflammation, immunity, food intake, and gonadal function and also regulates growth hormone (GH) secretion in rat adenopituitary cells cultures with the adipokine. Although adipose tissue is the primary source of resistin, it is also expressed in other tissues, including the pituitary. The aim of this study is to investigate the possible action of resistin on the lipid metabolism in the pituitary gland in vivo (rats in two different nutritional status, fed and fast, treated with resistin on acute and a chronic way) and in vitro (adenopituitary cell cultures treated with the adipokine). Here, by a combination of in vivo and in vitro experimental models, we demonstrated that central acute and chronic administration of resistin enhance mRNA levels of the lipid metabolic enzymes which participated on lipolysis and moreover inhibiting mRNA levels of the lipid metabolic enzymes involved in lipogenesis. Taken together, our results demonstrate for the first time that resistin has a regulatory role on lipid metabolism in the pituitary gland providing a novel insight in relation to the mechanism by which this adipokine can participate in the integrated control of lipid metabolism
    corecore