PSCF and CWT methods as a tool to identify potential sources of 7Be and 210Pb aerosols in Granada, Spain.

This research is focused on studying the preferred source regions and the pathways of the air masses with high particulate concentrations impacting on the activity concentrations of 7Be and 210Pb aerosols in Granada atmosphere. For this purpose, three different source-receptor methods have been used: Cluster Analysis, Potential Source Contribution Function (PSCF), and Concentration Weighted Trajectory (CWT). Air filter samples were weekly collected and analysed in Granada university (Spain 37.177N, 3.598 W, 687m a.s.l.) during 12 years (2006-2017) for the activity concentration of 7Be, and during 5 years (2010-2014) for the one of 210Pb. The time series of the collected data indicate that the concentration of both radiotracers present a cyclical and seasonal pattern, in association with their origins and atmospheric conditions. Clustering analysis showed that the air masses arriving to Granada can be classified as: (1) tropical continental air masses coming from the Mediterranean Sea, (2) tropical and warm polar maritime air masses produced over the Atlantic Ocean, and (3) continental air masses originated over Europe and Northern Africa. The PSCF and CWT methods confirmed that the main source areas of 7Be are located in the Atlantic coast of southern Morocco, and Northern Africa. On the other hand, southern France and the Algerian desert were found to be the main region sources of 210Pb. In addition, the Mediterranean Basin has been postulated as a strong source region for 7Be and 210Pb. Furthermore, the PSCF and CWT models show that the regions with larger 7Be/210Pb ratios are located in the Atlantic Ocean, due to frequent stratospheric intrusions specially during the winter months.

First principles calculation for generating new thermal neutron scattering data for Zirconium hydride.

Lattice parameters of materials have the same magnitude as the energy of thermal neutrons in reactors, which directly affects the neutron cross section and its energy. While they are thermalized, incident neutrons can lose or gain energy during their interactions with materials components. Since several decades, methods and models were developed in the aim to generate nuclear data sub-libraries required in correcting neutrons interactions cross sections at thermal energies. However, very few experimental works were dedicated to this field. In this paper we focus our efforts on reviewing the theoretical models and their adequacy in describing thermal scattering events in the aim of proposing new formalisms to calculate the density of states (DOS) and phonon responses of zirconium hydride material, which constitutes an important moderator of neutrons in TRIGA reactors fuel elements. Generally the effects of thermal scattering are provided in nuclear data evaluations by a thermal sub-library ENDF file 7. Data in file 7 are described by the known thermal scattering law S(α,ß) which is a function of momentum transfer and energy transfer parameters α and ß respectively. The thermal scattering law has been used to calculate the double differential cross sections and the corresponding results are presented. Although the comparison with other models shows satisfactory results, no previously personalized use of data may be the raison of its usefulness in some cases and not in others.

Invited review: Compost-bedded pack barns for dairy cows.

Compost-bedded pack barns (CBP) are receiving increasing attention as a housing system for dairy cows that has potential to improve animal welfare. This article reviews current scientific knowledge about CBP with the aim of providing a comprehensive tool for producers and researchers using this housing system. In CBP, cows are provided with an open bedded pack area rather than the individual stalls and concrete alleys found in freestall systems. The bedded pack, a mixture of organic bedding and cattle excreta, is cultivated frequently (1-3 times per day) to incorporate fresh manure and air into the pack, thus promoting an aerobic composting process. To function well, CBP generally require a large area per cow. Optimal animal densities over the bedded area range from 7.4 to more than 15 m2/cow depending on several factors, including climate, bedding, pack management, and cow characteristics. Studies have indicated that CBP, compared with conventional systems such as freestall barns, have the potential to improve the welfare of dairy cows. In particular, the main reported benefits include improved comfort during resting, better foot and leg health, and more natural animal behavior. Research has also indicated that adequate udder health can be achieved in CBP. However, because the bedded pack has been shown to contain high bacterial concentrations, proper management is essential to maintain adequate cow cleanliness and reduce the risk of mastitis. Controlling pack moisture is consistently indicated as the most important issue with CBP. Especially under cold and humid weather conditions, large amounts of bedding may be necessary to keep the pack adequately dry and comfortable for the cows. Nevertheless, the improvements in cow health may offset the higher costs of bedding.

A study of some changes of cell-mediated immunity in protein energy malnutrition.

This work was done to assess both monocytic and lymphocytic functions and to identify their role in the altered immunocompetence in protein energy malnutrition (PEM). This was accomplished through the evaluation of the phagocytic function and the in vitro production of interleukin 1 and interleukin 2 (IL-1 and IL-2) from cultured mononuclear cells. Forty patients with PEM within the age of (5-20 months) and twenty normal healthy subjects of matched age and sex were studied. They were subjected to complete blood picture, total serum protein, serum albumin, C3, C4, monocyte phagocytic function and in vitro production of both IL-1 and Il-2 from cultured mononuclear cells. Patients were graded on the basis of their clinical findings into three groups: Marasmic, marasmic kwashiorkor and Kwashiorkor. The study revealed that monocyte phagocytosis, complement components, in vitro production of IL-1 and IL-2 were significantly lower in the patients group when compared to normal control group, this increase was most obvious in the marasmic Kwashiorkor and Kwashiorkor groups. In addition, mononuclear cells from the infected patients produced less IL-1, Il-2 although the total leucocytic count was significantly increased than in the non-infected patients, indicating a functional rather than numerical cellular impairment. It was concluded that both monocytic and lymphocytic functions were impaired in PEM. This functional impairment may be involved in the failure of development of specific immune response and predisposed to increased susceptibility to infection in these patients.