4,002 research outputs found

    Integrated approach for prediction of centrifugal fertilizer spread patterns

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    The present paper proposes a numerical approach for prediction of behavior of those fertilizers spreaders based on centrifugal disc functioning. In particular results from finite element multi-body simulations provided by commercial software are used in order to define boundary conditions of field tests carried out concurrently. Results are then integrated into a mathematical model to rapidly generate distribution charts and distribution diagrams. Such integrated approach can be implemented to effectively calibrate a theoretical model which provides simulations on different machine settings conditions: as a final point simulations allow fast testing of different distribution conditions, helping definition of those which minimize the variability of the distribution itself

    Integrated approach for prediction of centrifugal fertilizer spread patterns

    Get PDF
    The present paper proposes a numerical approach for prediction of behavior of those fertilizers spreaders based on centrifugal disc functioning. In particular results from finite element multi-body simulations provided by commercial software are used in order to define boundary conditions of field tests carried out concurrently. Results are then integrated into a mathematical model to rapidly generate distribution charts and distribution diagrams.Such integrated approach can be implemented to effectively calibrate a theoretical model which provide simulations on different machine settings conditions: as a final point simulations allow fast testing of different distribution conditions, helping definition of those which minimize the variability of the distribution itself.

    Tractor cabin ergonomics analyses by means of Kinect motion capture technology

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    Kinect is the de facto standard for real-time depth sensing and motion capture cameras. The sensor is here proposed for exploiting body tracking during driving operations. The motion capture system was developed taking advantage of the Microsoft software development kit (SDK), and implemented for real-time monitoring of body movements of a beginner and an expert tractor drivers, on different tracks (straight and with curves) and with different driving conditions (manual and assisted steering). Tests show how analyses can be done not only in terms of absolute movements, but also in terms of relative shifts, allowing for quantification of angular displacements or rotations

    Sperm storage by males causes changes in sperm phenotype and influences the reproductive fitness of males and their sons

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    Recent studies suggest that environmentally induced effects on sperm phenotype can influence offspring phenotype beyond the classic Mendelian inheritance mechanism. However, establishing whether such effects are conveyed purely through ejaculates, independently of maternal environmental effects, remains a significant challenge. Here, we assess whether environmentally induced effects on sperm phenotype affects male reproductive success and offspring fitness. We experimentally manipulated the duration of sperm storage by males, and thus sperm age, in the internally fertilizing fish Poecilia reticulata. We first confirm that sperm ageing influences sperm quality and consequently males reproductive success. Specifically, we show that aged sperm exhibit impaired velocity and are competitively inferior to fresh sperm when ejaculates compete to fertilize eggs. We then used homospermic (noncompetitive) artificial insemination to inseminate females with old or fresh sperm and found that male offspring arising from fertilizations by experimentally aged sperm suffered consistently impaired sperm quality when just sexually mature (four months old) and subsequently as adults (13 months old). Although we have yet to determine whether these effects have a genetic or epigenetic basis, our analyses provide evidence that environmentally induced variation in sperm phenotype constitutes an important source of variation in male reproductive fitness that has far reaching implications for offspring fitness

    CMS DT Chambers: Optimized Measurement of Cosmic Rays Crossing Time in absence of Magnetic Field

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    Two spare drift chambers produced in the I.N.F.N. Legnaro Laboratory (Padova, Italy) for the barrel muon spectrometer of the LHC CMS experiment have been extensively tested using cosmic-ray muons. A fitting algorithm was developed to optimize the determination of the time of passage of the particle. A timing resolution of \approx2~ns has been obtained. The algorithm permits the measurement of the track reconstruction precision of the chambers by using cosmic-ray data with the same accuracy obtained using high-energy test-beam data

    Ergonomics analyses through motion capture in a vehicle cabin by means of Kinect sensor

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    Abstract Ergonomics studies encompass a lot of researches aimed to the evaluation of the discomfort and of the suitability of a tractor cabin at different working conditions. In the present study for driver movements analysis we propose implementation of the Kinect sensor, a low-cost infrared depth camera allowing markerless skeletal tracking, both in standing or seating position. Such sensor allows generation of a stick skeleton mode, extracting and tracking skeletal joint locations (two for each hand, two for the head, four for shoulders and arms, etc.) at a sampling rate of 10 positions per second. The tracking system was developed by means of the Microsoft software development kit (SDK), and allowed tracking of body movements of a tractor driving person for several minutes. In order to test the applicability of the sensor, it was applied for monitoring two different drivers (an expert and a beginner) on two different paths taking advantage of a 81 kW tractor allowing assisted steering. Tests highlights how the sensor can be successfully implemented for quantification of drivers body movements

    Pretreatment with verapamil in patients with persistent or chronic atrial fibrillation who underwent electrical cardioversion

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    AbstractOBJECTIVESTo evaluate, in a prospective and randomized fashion, the efficacy of a pretreatment with verapamil (V) in reducing recurrences of atrial fibrillation (AF) after electrical cardioversion (C).BACKGROUNDThe increased vulnerability for AF recurrence is probably due to AF-induced changes in the electrophysiologic properties of the atria. This electrical remodeling seems to be due to intracellular calcium overload.METHODSOne hundred seven patients with persistent or chronic AF underwent external and/or internal C. All patients received oral propafenone (P) (900 mg/day) three days before and during the entire period of follow-up (three months). In the first group, patients received only the P. In the second group, in adjunct to P, oral V (240 mg/day) was initiated three days before C and continued during the follow-up. Finally, in the third group, oral V was administered three days before and continued only for three days after electrical C.RESULTSDuring the three months of follow-up, 23 patients (23.7%) had AF recurrence. Mantel-Haenszel cumulative chi-square reached a significant level only when comparing AF free survival curves of group I versus group II and group III (chi-square = 5.2 and 4, respectively; p < 0.05). Significantly, 15 (65.2%) AF relapses occurred during the first week after cardioversion with a higher incidence in group I (10/33 patients, 30.3%) than group II (2/34 patients, 5.9%; p = 0.01) and group III (3/30 patients, 10%; p = 0.04).CONCLUSIONSSix days of oral V administration centered on the C day, combined with P, significantly reduce the incidence of early recurrences of AF compared with P alone

    Tolerability of new antiepileptic drugs:a network meta-analysis

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    Objective: The objective of this study was to perform a comparative assessment of tolerability of all licensed new antiepileptic drugs (AEDs) through a network meta-analysis (NMA) including all placebo-controlled double-blind clinical trials (RCTs) in all conditions in which these drugs have been tested. Methods: NMA with a frequentist approach was used to compare proportions of patients withdrawing because of adverse events (AEs). Analyses were conducted for all therapeutic doses pooled and specifically for high therapeutic doses. Patients treated with non-therapeutic doses of each drug were excluded. Results: A total of 195 RCTs were included in the current analysis, comprising a total of 28,013 patients treated with AEDs and 17,908 patients treated with placebo. RCTs included in the analysis were 8 for brivaracetam; 5 for eslicarbazepine; 22 for gabapentin; 7 for lacosamide; 14 for levetiracetam; 14 for lamotrigine; 6 for oxcarbazepine; 9 for perampanel; 50 for pregabalin; 5 for tiagabine; 36 for topiramate; 7 for zonisamide; 4 for gabapentin-extended formulation (ER); 2 each for levetiracetam-ER, lamotrigine-ER, and topiramate-ER; and 1 each for oxcarbazepine-ER and pregabalin-ER. Brivaracetam, gabapentin, gabapentin-ER, and levetiracetam had a significantly lower withdrawal rate compared to several other AEDs, while eslicarbazepine, lacosamide, oxcarbazepine, and topiramate had a higher withdrawal rate. Perampanel, lamotrigine, pregabalin, tiagabine, and zonisamide showed an intermediate pattern of tolerability. Additional analysis has been conducted through selection of highly recommended doses for each drug. This analysis has roughly confirmed results of head to head comparisons of the all-dose analysis, with some exceptions. A further analysis has been conducted after exclusion of RCTs in which patients were allocated to the therapeutic dose of the experimental drug without titration, and it failed to show clinically important differences. Significance: Relevant differences in short-term tolerability of AEDs have been observed between AEDs. Brivaracetam, gabapentin, and levetiracetam show the best tolerability profile while other AEDs are at higher risk for intolerable adverse effects

    Post-graduate medical education in public health: The case of Italy and a call for action

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    Public health technical expertise is of crucial importance to inform decision makers\u2019 action in the field of health and its broader determinants. Improving education and training of public health professionals for both practice and research is the starting point to strengthen the role of public health so that current health challenges can be efficiently tackled. At the Association of Schools of Public Health in the European Region (ASPHER) Deans\u2019 & Directors\u2019 2017 Annual Retreat, we presented the structure and management of public health training system in Italy, and we reported recent data on Italian public health specialists\u2019 educational experience, employment opportunities and job satisfaction. Public health training in Italy is implemented in the context of the post-graduate medical education residency programme in Hygiene and Preventive Medicine, delivered by 34 University-based Schools of Public Health. We report relatively high employment rates across the county and wide spectrum of career opportunities for young public health specialists. However, job security is low and training expectations only partially met. We call upon other Schools of Public Health to scale up the survey within the broad ASPHER community in a shared and coordinated action of systematically collecting useful data that can inform the development of public health education and training models, their implementation and fruitful interaction with population health, health systems and services
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