308 research outputs found

    EXTRAPOLATING INTRA-CLUSTER CORRELATION TO OPTIMIZE THE SIZE OF SEGMENTS IN AN AREA FRAME.

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    In the frame of the Rapid Crop Area Estimates in the European Community we use a sample of squared segments (pieces of land) of 49 ha. each; estimates are made for difference of crop areas between years. The optimum size seems to be larger than the current one, and much larger if ground survey data are obtained by photo-interpretation. The main purpose of this paper is to assess a method, based on splitting the segments into pieces of 1/4 ha., to forecast the precision of estimates with larger segments. The tests made for France confirm the belief that better estimates can be obtained with a fixed cost by enlarging the size of the segments . We consider as well the problem of assessing smaller segments, for which an easier technique can be used

    Seismic monitoring of gas emissions at mud volcanoes: The case of Nirano (northern Italy)

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    Seismic signals generated at the Nirano mud volcanoes in Northern Italy have been monitored by deploying a set of small dimensions seismic arrays of vertical geophones and thee-directional sensors. During two seismic surveys campaigns, seismic signals characterized by sequences of short impulsive signals (lasting 0.1 s–0.2 s) were identified above the background seismic noise. The respective seismic sources have been identified at shallow depths (<30 m) and results sparsely distributed over a wide area. Estimated propagation velocities and polarization analysis indicate that detected pulses also include a significant S waves contribution. These findings have been interpreted as the effect of a stick-slip mechanism due to the interaction between exsolved gas bubbles, mud plugs and the vent walls. On the basis of this model, an estimate of the gas outflow was attempted and results in line with independent measurements of CH4 and CO2 emissions carried out in the area

    Pd-Catalysed oxidative carbonylation of α-amino amides to hydantoins under mild conditions

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    The first example of palladium-catalysed oxidative carbonylation of unprotected α-amino amides to hydantoins is described here. The selective synthesis of the target compounds was achieved under mild conditions (1 atm of CO), without ligands and bases. The catalytic system overrode the common reaction pathway that usually leads instead to the formation of symmetrical ureas

    Recognition in emergency department of septic patients at higher risk of death: Beware of patients without fever

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    Background and Objectives: Chances of surviving sepsis increase markedly upon prompt diagnosis and treatment. As most sepsis cases initially show-up in the Emergency Department (ED), early recognition of a septic patient has a pivotal role in sepsis management, despite the lack of precise guidelines. The aim of this study was to identify the most accurate predictors of in-hospital mortality outcome in septic patients admitted to the ED. Materials and Methods: We compared 651 patients admitted to ED for sepsis (cases) with 363 controls (non-septic patients). A Bayesian mean multivariate logistic regression model was performed in order to identify the most accurate predictors of in-hospital mortality outcomes in septic patients. Results: Septic shock and positive qSOFA were identified as risk factors for in-hospital mortality among septic patients admitted to the ED. Hyperthermia was a protective factor for in-hospital mortality. Conclusions: Physicians should bear in mind that fever is not a criterium for defining sepsis; according to our results, absence of fever upon presentation might be indicative of greater severity and diagnosis of sepsis should not be delayed

    Aggiornamenti e novitĂ  sulle conoscenze di Pancratium maritimum (Amaryllidaceae)

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    Pancratium maritimum L., bulbosa perenne degli ambienti dunali costieri, è un taxon relativamente recente se comparato con le specie del genere a gravitazione mediterranea. Gli studi noti su questa specie hanno analizzato vari aspetti della biologia (riproduttivi, biochimici, filogenetici, genetici, ecc.). Tuttavia, esistono ancora lacune scientifiche, tra cui l’assenza di studi su ampio areale di genetica di conservazione e sugli adattamenti eco-morfofisiologici alle condizioni di stress. Per ampliare le conoscenze su P. maritimum, la Fondazione Nando Peretti nel novembre 2012 ha finanziato un progetto triennale sulla conoscenza e la salvaguardia di questa specie (Progetto 2012-83). In questo contributo si presentano i risultati ottenuti per le diverse linee di ricerca finora affrontate, che vanno dalle analisi ad ampio areale dei popolamenti, usando un approccio sia genetico che GIS, alla caratterizzazione morfologica e eco-fisiologica di varie popolazioni

    Smart Dairy Farming: Innovative Solutions to Improve Herd Productivity

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    Among the most straining trends that farmers have to face there are: on one side, to guarantee welfare and adequate life conditions for animals and to reduce the environmental footprint, on the other side, to develop new strategies to improve farm management reducing costs. The current conditions and the expected developments of the dairy sector highlight a strong need for more efficient and sustainable farming systems. Studying heat stress, herd management and housing and animals\u2019 productive and reproductive performances is fundamental for the economic and environmental sustainability of the dairy chain. New and effective tools to cope with these challenges have been provided by Precision Livestock Farming (PLF), which is nowadays increasingly applied and makes possible to control quali-quantitative parameters related to production, health, behaviour, and real-time locomotion per animal. The research key challenge is to turn these data into knowledge to provide real-time support in farming optimisation. This research focuses specifically on different systems to collect, process and derive useful information from data on animal welfare and productivity. A multi-disciplinary approach has been adopted to generate a decision support system for farmers

    Alternative sampling frames and administrative data; which is the best data source for agricultural statistics?

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    The extraordinary increase of ability to handle and manipulate large sets of data suggests an extensive use of administrative data for saving money, reducing response burden, producing figures for very detailed domains and estimating transition over time. However, statistical systems based on registers have some disadvantages and specific requirements which are analysed in the paper. Some of these disadvantages can be removed if registers are combined with list or area frame sample surveys through calibration estimators or multiple frames methodology
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