Genetic variation of goat Y chromosome in the Sardinian population

Sardinian goat population is commonly considered a crossbred of autochthonous animals with improved Mediterranean breeds, mainly the Maltese. It has been demonstrated by using autosomal microsatellites that the Sardinian goats can be divided into three subpopulations: Sardinian, crossbred with Maltese, and Maltese. The aim of this study was to evaluate sequence variation at Y chromosome in Sardinian bucks and to integrate autosomal microsatellites data. Blood from 190 bucks from 68 farms spread in the main Sardinian goat farming areas was sampled. Three ECONOGENE project primer pairs plus an additional one corresponding to a total of 7 SNPs were used. For all common SNPs, the most frequent allele corresponded to the ECONOGENE one. The additional analysed SNP showed allelic frequencies similar to the other markers. The comparison with haplotypes based on the 6 common SNPs showed that the Sardinian most frequent haplotype corresponded to the predominant one in Central Europe. Results of this study showed that the Sardinian goat population has 8 haplotypes resulting in a large diversity of paternal lineages. The next step will be linking autosomal information to Y chromosome data. In fact, up to date, it seems unfeasible to detect recent upgrading breeds by using Y chromosome variation only

Phenomenology of liquid metal thermal-hydraulics

The cooling system of the Energy Amplifier (EA) is based on a Lead flow driven by natural circulation [1]. In the Energy Amplifier Demonstration Facility (EADF) a Lead-Bismuth eutectic is used and natural circulation, although enhanced through a gas injection system, is the pumping force for the cooling of both the target (only in the case of the window-type target) and the primary circuit[2]. Numerical simulation is extensively used for the design and analysis of these flows, using both commercial and in-house codes. However, liquid metals properties are very different from that of common fluids, so the physical models to be used in the simulations should be carefully assessed. In general the numerical simulation of any kind of flow requires: (i) the thermodynamic modelling of the fluid; (ii) the fluid dynamics governing equations; (iii) the turbulence modelling. In this work the thermodynamic model for heavy liquid metals is presented, starting with the derivation of the equations of state for a general fluid from the basic laws of thermodynamics. This thermodynamic model is then used for the analysis of a one-dimensional natural convection loop, in order to put in evidence the main physical mechanisms governing this particular kind of flow and the simplifications that can be applied to the one dimensional governing equations. An extensive analysis of the tree-dimensional fluid dynamic governing equations and of the turbulence models for liquid metal flows can be found in [7] and [8] respectively

Thermo-mechanical stresses on the beam window

The Centre for Advanced Studies, Research and Development in Sardinia (CRS4) is participating to an Italian R&D program, together with Ansaldo, ENEA and INFN, devoted to the design of a 80 MW prototype of the Energy Amplifier proposed by C. Rubbia. The use of advanced numerical tools has been of practical support in the design of critical elements of the machine such as the fuel element and the beam target. The aim of this work is to study the sensitivity of beam window stresses to the beam distribution, size and interruption. In order to compute thermal stresses, the heat deposition in the window and in the coolant generated by the interaction with the proton beam is calculated and used as input data for the fluid dynamic simulation of the natural convection flow of the target coolant

Numerical methodologies for the simulation of liquid metal flows

The fluid-dynamic modelling for the simulation of the Lead-Bismuth flow in the EADF was reviewed. The general form of the non-dimensional governing equation was derived, and the analysis of the orders of magnitude of the different terms in the case of a the liquid metal flows in the EADF was performed, through a flow-Mach number asymptotic analysis. It was found that the resulting form of the equations is the one commonly used in commercial CFD codes for the simulation of liquid flows, which can then be used for our applications. The most common numerical methods for flow-Mach number applications were also presented. These methods are general and can be applied to liquid metal flows without any modification. The peculiarity of the numerical simulation of liquid metal flows lies in the modelling of the turbulent heat transfer, due to the flow Prandtl number of this type of fluids. This subject is discussed in [21]

Integration of numerical tools for the combined thermal-hydraulics and structural analysis of energy amplifier components

The CRS4 R&D activity on the Energy Amplifier Demonstration Facility (EADF) [1] concerns the thermal fluid-dynamic and structural computational analysis in support to the design of some of the crucial components of the machine. We are currently studying the operating conditions of the spallation target [2-3] and the sub-critical core [4-5], including steady state, transient [31-32] and accidental conditions. The simulation activity also includes the analysis of multi-phase (liquid-gas systems with high void fractions) [6-7] and free surface Liquid Metal (LM) flows [8-9]. A parallel activity of benchmarking of numerical codes on LM experiments is in progress [10-12, 33-34], joined with a critical theoretical review of numerical models applied to LM flows [13-15]

Numerical studies related to the design of the beam target of the energy amplifier prototype

The Centre for Advanced Studies, Research and Development in Sardinia (CRS4) is participating in an Italian R&D program, together with Ansaldo, ENEA and INFN, devoted to the design of a 80 MW prototype of the Energy Amplifier proposed by C. Rubbia et al.. The use of advanced numerical tools has been of practical support in the design of critical elements of the machine such as the fuel element and the beam target. The aim of this work is to show the design and optimization of the Liquid Metal Spallation Target, which consists in an axial-symmetric vertical cylinder, where a Pb-Bi eutectic, in a natural convection driven flow regime, works at the same time as spallation material and coolant for the target and the beam window. The most critical part of the target is the window itself, where the highest temperatures and thermal stresses are reached. The minimization of such temperatures and stresses is the goal of the optimization. The main geometrical dimensions of the target (i.e. beam pipe, beam window and external container) are somehow fixed since they are related to the proton beam distribution and to the EA core design. The optimization therefore acts on the suitable design of the flow guide which separates the hot rising flow from the cold one. In the region where the flow is heated by the proton beam the flow guide has a funnel shape which accelerates the liquid metal. The numerical simulations are performed by using three different tools. The FLUKA Montecarlo code is used to calculate the heat source distribution in the window and in the coolant generated by the interaction with the proton beam. The results of these calculations are used as input data for the thermal fluid dynamic simulations performed with the STAR-CD commercial software. The resulting temperature and pressure fields are finally introduced in the NASTRAN code used for the structural analysis of the solid components

Detection on OAR7 of QTL affecting fat and protein yields in dairy sheep

The objective of this paper was identifying QTL that affect fat and protein yields in dairy sheep independently of milk yield. Data were collected in an experimental flock of 887 ewes organized in a daughter design. QTL detection focused on OAR7 where 13 microsatellites were available. The genetic abilities to produce fat and protein independently from the ability to produce milk were estimated as the residuals of the regression of EBV for fat and protein yields on EBV for milk yield. One QTL affecting fat yield (CWP=0.00009) and one QTL affecting protein yield (CWP=0.006) were detected. The most probable QTL location was 115.3 cM in the Sheep Best Position Linkage Map Version 4.7 for both traits. No QTL affecting milk yield was detected. The analysis of fat and protein yields independently of milk yield is an effective strategy to identify chromosomal regions affecting milk composition with no detrimental effect on milk yield

Role of HBcAb Positivity in Increase of HIV-RNA Detectability after Switching to a Two-Drug Regimen Lamivudine-Based (2DR-3TC-Based) Treatment: Months 48 Results of a Multicenter Italian Cohort

: The aim of this study was to evaluate whether the presence of anti-hepatitis B (HBV) c antibodies (HBcAb positivity) could influence the control of HIV viremia in patients living with HIV (PLWH) who switch to two-drug antiretroviral therapy (2DR) containing lamivudine (3TC) (2DR-3TC-based). A retrospective multicentre observational study was conducted on 160 PLWH switching to the 2DR-3TC-based regimen: 51 HBcAb-positive and 109 HBcAb-negative patients. The HBcAb-positive PLWH group demonstrated a significantly lower percentage of subjects with HIV viral suppression with target not detected (TND) at all time points after switching (24th month: 64.7% vs. 87.8%, p < 0.0001; 36th month 62.7% vs. 86.8%, p = 0.011; 48th month 57.2% vs. 86.1%, p = 0.021 of the HBcAb-positive and HBcAb-negative groups, respectively). Logistic regression analysis showed that the presence of HBcAb positivity (OR 7.46 [95% CI 2.35-14.77], p = 0.004) could favour the emergence of HIV viral rebound by nearly 54% during the entire study follow-up after switching to 2DR-3TC

Modeling Parkinson's Disease Neuropathology and Symptoms by Intranigral Inoculation of Preformed Human α-Synuclein Oligomers.

The accumulation of aggregated α-synuclein (αSyn) is a hallmark of Parkinson's disease (PD). Current evidence indicates that small soluble αSyn oligomers (αSynOs) are the most toxic species among the forms of αSyn aggregates, and that size and topological structural properties are crucial factors for αSynOs-mediated toxicity, involving the interaction with either neurons or glial cells. We previously characterized a human αSynO (H-αSynO) with specific structural properties promoting toxicity against neuronal membranes. Here, we tested the neurotoxic potential of these H-αSynOs in vivo, in relation to the neuropathological and symptomatic features of PD. The H-αSynOs were unilaterally infused into the rat substantia nigra pars compacta (SNpc). Phosphorylated αSyn (p129-αSyn), reactive microglia, and cytokine levels were measured at progressive time points. Additionally, a phagocytosis assay in vitro was performed after microglia pre-exposure to αsynOs. Dopaminergic loss, motor, and cognitive performances were assessed. H-αSynOs triggered p129-αSyn deposition in SNpc neurons and microglia and spread to the striatum. Early and persistent neuroinflammatory responses were induced in the SNpc. In vitro, H-αSynOs inhibited the phagocytic function of microglia. H-αsynOs-infused rats displayed early mitochondrial loss and abnormalities in SNpc neurons, followed by a gradual nigrostriatal dopaminergic loss, associated with motor and cognitive impairment. The intracerebral inoculation of structurally characterized H-αSynOs provides a model of progressive PD neuropathology in rats, which will be helpful for testing neuroprotective therapies