1,694 research outputs found
Radioprotection calculations for MEGAPIE
The MEGAwatt PIlot Experiment (MEGAPIE) liquid lead-bismuth spallation neutron source will commence operation in 2006 at the SINQ facility of the Paul Scherrer Institut. Such an innovative system presents radioprotection concerns peculiar to a liquid spallation target. Several radioprotection issues have been addressed and studied by means of the Monte Carlo transport code, FLUKA. The dose rates in the room above the target, where personnel access may be needed at times, from the activated lead-bismuth and from the volatile species produced were calculated. Results indicate that the dose rate level is of the order of 40 mSv h−1 2 h after shutdown, but it can be reduced below the mSv h−1 level with slight modifications to the shielding. Neutron spectra and dose rates from neutron transport, of interest for possible damage to radiation sensitive components, have also been calculate
Parity Violation in Neutron Capture Reactions
In the last decade, the scattering of polarized neutrons on compound nucleus
resonances proved to be a powerful experimental technique for probing nuclear
parity violation. Longitudinal analyzing powers in neutron transmission
measurements on p-wave resonances in nuclei such as La and Th
were found to be as large as 10%. Here we examine the possibilities of carrying
out a parallel program to measure asymmetries in the ) reaction on
these same compound nuclear resonances. Symmetry-violating ) studies
can also show asymmetries as large as 10%, and have the advantage over
transmission experiments of allowing parity-odd asymmetries in several
different gamma-decay branches from the same resonance. Thus, studies of parity
violation in the reaction using high efficiency germanium
detectors at the Los Alamos Lujan facility, for example, could determine the
parity-odd nucleon-nucleon matrix elements in complex nuclei with high
accuracy. Additionally, simultaneous studies of the E1 and matrix
elements invol ved in these decays could be used to help constrain the
statistical theory of parity non-conservation in compound nuclei.Comment: 10 pages, 1 figur
Factors affecting the patterns of total amount and proportions of leukocytes in Bovine milk
Differential leukocyte count (DSCC) in milk is considered important to improve knowledge of udder immune response. The investigations on milk DSCC were limited by the techniques available until recently, when a high-throughput tool to perform DSCC opened the way to explore these factors in rapid and economically sustainable ways. We hypothesized that DSCC alone does not fully describe the pattern of these cells, since the total amount is also influenced by milk yield and SCC. Therefore, this study was designed to describe DSCC and total amount of different leukocytes in milk during the course of lactation in cows differing in parity and in levels of SCC. This study considered 17,939 individual milk tests from 12 dairy herds in Lombardy Region, where DCC testing was applied in the period of February 2018\u2013December 2019 (23 months). The samples were divided into two subsets\u2014\u201chealthy\u201d (HS) with SCC 64200,000 cells/mL and \u201cinflamed\u201d (IS) with SCC >200,000 cells/mL. Cow in HS have a P + LT average between 5.0
7 108 and 3.0
7 109 cells. In IS cows, the values were 1.6
7 1010 and 2.5
7 1010. Therefore, the presence of a well-defined inflammatory process increased the overall amount of polymorphonuclear neutrophils (PMN) and lymphocytes (LYM) of 1 log, from 1
7 109 to 1
7 1010. The assessment of the total amount of PMN and LYM, to our knowledge, have never been reported in scientific literature; the values observed may be proposed as benchmarks for studies on udder immune response. When data were analyzed by days in milk (DIM),they showed that cows in first and second lactation have a significantly lower amount of PMN + LYM, when compared to cows in third and higher lactation. However, these differences are numerically not very large (7%), and suggest that, in healthy animals, the number of immune cells is kept as constant as possible. In IS, the analysis of trends based on DIM showed that both DSCC and P + LT have a significant negative trend. These data suggest that only in this group, the presence of high SCC as lactation proceeds is associated with a progressive increase in the number of macrophages. To the best of our knowledge, this is the first study describing the pattern of DSCC and the total amount of PMN + LYM in relation to parity, days in milk, and SCC, and it may be considered as the first contribution in the investigation on mammary gland immune response by the means of differential cell counts in milk
Milking procedures and milk ejection in Italian Brown cows
The aim of the study was to describe, on the basis of field data, the traits of milk flow curves of Italian Brown cows and to investigate some sources of variation. A total of 1,450 milk flow curves of the whole udder were collected in 81 Italian Brown dairy herds in Lombardy, Italy, using electronic mobile milk flow meters. Parity order and days in milk affected most milk flow traits. Milk flow curves showed some defects dependent on milking management practices: very long machine-on time, long duration of overmilking phase, high percentage of stripping and moderate percentage of bimodality
Managerial features and outcome in neonatal intensive care units: results from a cluster analysis
Background: Healthcare organisations differ in performance even if they are located in the same country or region. Suitable managerial practices and organisational processes can lead to better health outcomes. As a result, hospitals are constantly looking for managerial arrangements that can improve outcomes and keep costs down. This study aims to identify different managerial models in neonatal intensive care units (NICUs) and their impact on a large number of outcomes. Methods: The research was conducted in Italy, within the SONAR project. SONAR’s aim was to identify the characteristics of NICUs, monitor outcomes and promote best practices. This study includes 51 of the 63 NICUs that took part in the SONAR project. Questionnaires on the activities and managerial features were administered to doctors and nurses working in NICUs. A total of 643 questionnaires were analysed from doctors and a total of 1601 from nurses. A cluster analysis was performed to identify managerial models of NICUs. Results: Three managerial models emerged from cluster analysis: traditional, collaborative and individualistic. In the “traditional” model the doctor is above the nurse in the hierarchy, and the nurse therefore has exclusively operational autonomy. The “collaborative” model has as key elements professional specialisation and functional coordination. The “individualistic” model considers only individual professional skills and does not concern the organisational conditions necessary to generate organisational effectiveness. The results also showed that there is an association between managerial model and neonatal outcomes. The collaborative model shows best results in almost all outcomes considered, and the traditional model has the worst. The individualistic model is in the middle, although its values are very close to those of traditional model. Conclusions: Health management needs to assess NICU strategically in order to develop models to improve outcomes. This study provides insights for management useful for designing managerial characteristics of NICUs in order to achieve better results. NICUs characterised by a collaborative model in fact show better neonatal outcomes
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