552 research outputs found
Assessment of limits for racing speed in the Italian trotter population
The current world record for trotter is 68.0 s/km, that is better than the estimates of record limit reported in literature (68.2 s/km for males and 69.1 s/km for females in Swedish Trotters): this is way the record limit was investigated in Italian Trotter using the same methodology applied to Swedish Trotter. The best racing times of 30'587 3-5 year old Italian Trotters, recorded between January 1st, 1992, and October 31th, 2009, have been log transformed to check for trends and asymptotic limit: a positive trend is present, and limits of 61.8 s/km and 62.8 s/km have been respectively estimated for males and females. The Generalized Extreme Value theory, applied to the 3-year old winners of the Italian Trot Derby, estimates a limit of 64.7 s/km. These results indicate that the limit for racing speed is still far from actual values
the use of a random regression model on the estimation of genetic parameters for weight at performance test in appenninica sheep breed
The Appenninica breed is an Italian meat sheep; the rams are approved according to a phenotypic index that is based on an average daily gain at performance test. The 8546 live weights of 1930 Appenninica male lambs tested in the performance station of the ASSONAPA (National Sheep Breeders Association, Italy) from 1986 to 2010 showed a great variability in age at weighing and in number of records by year. The goal of the study is to verify the feasibility of the estimation of a genetic index for weight in the Appenninica sheep by a mixed model, and to explore the use of random regression to avoid the corrections for weighing at different ages. The heritability and repeatability (mean±SE) of the average live weight were 0.27±0.04 and 0.54±0.08 respectively; the heritabilities of weights recorded at different weighing days ranged from 0.27 to 0.58, while the heritabilities of weights at different ages showed a narrower variability (0.29÷0.41). The estimates of live weight heritability by random regressions ranged between 0.34 at 123 d of age and 0.52 at 411 d. The results proved that the random regression model is the most adequate to analyse the data of Appenninica breed
morphological and genetic characterisation of pagliarola breed and its genetic relationships with other three indigenous italian sheep breeds
Sheep are an important livestock species in the socio-economic contest around the world. In the past, exotic sheep breeds were utilised in crosses with local breeds in order to improve their production traits. The Pagliarola is an ancient sheep population spread over many areas of the central Italy, mainly in Abruzzo region. The aim of this paper was to identify this breed from other sheep breeds living in the same area trough morphological and genetic characterisation. Fifty-three Pagliarola sheep animals (two flocks) were sampled together with 30 sheep of Appenninica, Gentile di Puglia and Merinizzata Italiana. Biometrical measures and 25 microsatellite markers were studied for the characterisation. In the morphological analysis, the Pagliarola was observed to be well separated from the other breeds and the genomic results confirmed the morphological study. In the molecular approach, a total of 330 alleles were detected. In the neighbour-Net tree, each breed clustered independently and no clear cluster was observed. The expected heterozygosity was the highest in Appenninica (0.78), while Pagliarola had the lowest (0.70). Results of STRUCTURE analyses at K=5 showed Pagliarola breed splitted in two sub-clusters. Both biometric and molecular results allow to consider the residual Pagliarola as an original genotype. Moreover, the variability still remaining in this population can be useful to plan suitable conservation programs
Bioenergetic relevance of hydrogen sulfide and the interplay between gasotransmitters at human cystathionine β-synthase
Merely considered as a toxic gas in the past, hydrogen sulfide (H2S) is currently viewed as the third ‘gasotransmitter’ in addition to nitric oxide (NO) and carbon monoxide (CO), playing a key signalling role in human (patho)physiology. H2S can either act as a substrate or, similarly to CO and NO, an inhibitor of mitochondrial respiration, in the latter case by targeting cytochrome c oxidase (CcOX). The impact of H2S on mitochondrial energy metabolism crucially depends on the bioavailability of this gaseous molecule and its interplay with the other two gasotransmitters. The H2S-producing human enzyme cystathionine β-synthase (CBS), sustaining cellular bioenergetics in colorectal cancer cells, plays a role in the interplay between gasotransmitters. The enzyme was indeed recently shown to be negatively modulated by physiological concentrations of CO and NO, particularly in the presence of its allosteric activator S-adenosyl-L-methionine (AdoMet). These newly discovered regulatory mechanisms are herein reviewed. This article is part of a Special Issue entitled ‘EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2–6, 2016’, edited by Prof. Paolo Bernardi
Multigrid algorithms for -discontinuous Galerkin discretizations of elliptic problems
Abstract. We present W-cycle multigrid algorithms for the solution of the linear system of equations arising from a wide class of hp-version discontinuous Galerkin discretizations of elliptic problems. Starting from a classical framework in multigrid analysis, we define a smoothing and an approximation property, which are used to prove the uniform convergence of the W-cycle scheme with respect to the granularity of the grid and the number of levels. The dependence of the convergence rate on the polynomial approximation degree p is also tracked, showing that the contraction factor of the scheme deteriorates with increasing p. A discussion on the effects of employing inherited or non-inherited sublevel solvers is also presented. Numerical experiments confirm the theoretical results. Key words. hp-version discontinuous Galerkin, multigrid algorithms, elliptic problem
Genetic differentiation between Segugio dell'Appennino and Segugio Maremmano dog breeds assessed by microsatellite markers
The domestic dog (Canis Familiaris) was the first species to be tamed and bred to occupy a variety of functions. The Segugio dell’Appennino and Segugio Maremmano are two Italian breeds used extensively as hunting dogs. Microsatellites and other genetic markers are useful tools in evaluating the within and between breed genetic variation. The aim of this study was to investigate genetic differentiation among the two reeds through the analysis of 21 microsatellite markers. The two populations share the same geographical regions but have been over time selected on different parameters to achieve specific functions. All the analysed microsatellite markers were polymorphic and the average number of alleles per locus was 8.19. The mean FIT index (0.051; P<0.05) highlights that at some point in time, the normal gene flow among the animals was disrupted, giving rise to a heterozygote deficiency in both breeds, and this is confirmed by the mean FST fixation index (0.010; P<0.05) clearly indicating an absence of a significant genetic differentiation between the two breeds. The mean FIS value was significantly different from zero (0.042) (P<0.05) reconfirming the presence of a lack of heterozygosity in the studied samples. The values of observed and expected heterozygosity were similar in the two breeds. AMOVA, PCA and STRUCTURE analysis, all emphasise the lack of significant differences mong the two breeds in terms of genetic differentiation. The presence of a population substructure is probably due to a genetic introgression from different Segugio breeds, that can be confirmed with further studies
Gender, migration and the ambiguous enterprise of professionalizing domestic service: the case of vocational training for the unemployed in France
Drawing on ethnographic data concerning migrant male domestic workers, this article examines the gendered dimensions of the process of racialization in Italy and France. First, it shows that specific racialized constructions of masculinity are mobilized by the employers as well as by training and recruitment agencies. These constructions of masculinity are related to different forms of organization of the sector in each country and to different ideologies about the integration of migrants. Second, the data presented reveal the strategies used by migrant male domestic workers to reaffirm their masculinity in a traditionally feminized sector. In doing so, this article intends to explore the connections between international migration and the gendering of occupations, with regard to the construction and management of masculinities in domestic service. Finally, by examining men’s experiences, this article aims to contribute to a more complex definition of the international division of care work
On the origin and diversification of Podolian cattle breeds: testing scenarios of European colonization using genome-wide SNP data
During the Neolithic expansion, cattle accompanied humans and spread from their domestication centres to colonize the ancient world. In addition, European cattle occasionally intermingled with both indicine cattle and local aurochs resulting in an exclusive pattern of genetic diversity. Among the most ancient European cattle are breeds that belong to the so-called Podolian trunk, the history of which is still not well established. Here, we used genome-wide single nucleotide polymorphism (SNP) data on 806 individuals belonging to 36 breeds to reconstruct the origin and diversification of Podolian cattle and to provide a reliable scenario of the European colonization, through an approximate Bayesian computation random forest (ABC-RF) approach
Runs of homozygosity in the Italian goat breeds: impact of management practices in low‑input systems
Background
Climate and farming systems, several of which are considered as low-input agricultural systems, vary between goat populations from Northern and Southern Italy and have led to different management practices. These processes have impacted genome shaping in terms of inbreeding and regions under selection and resulted in differences between the northern and southern populations. Both inbreeding and signatures of selection can be pinpointed by the analysis of runs of homozygosity (ROH), which provides useful information to assist the management of this species in different rural areas.
Results
We analyzed the ROH distribution and inbreeding (FROH) in 902 goats from the Italian Goat Consortium2 dataset. We evaluated the differences in individual ROH number and length between goat breeds from Northern (NRD) and Central-southern (CSD) Italy. Then, we identified the signatures of selection that differentiate these two groups using three methods: ROH, ΔROH, and averaged FST. ROH analyses showed that some Italian goat breeds have a lower inbreeding coefficient, which is attributable to their management and history. ROH are longer in breeds that are undergoing non-optimal management or with small population size. In several small breeds, the ROH length classes are balanced, reflecting more accurate mating planning. The differences in climate and management between the NRD and CSD groups have resulted in different ROH lengths and numbers: the NRD populations bred in isolated valleys present more and shorter ROH segments, while the CSD populations have fewer and longer ROH, which is likely due to the fact that they have undergone more admixture events during the horizontal transhumance practice followed by a more recent standardization. We identified four genes within signatures of selection on chromosome 11 related to fertility in the NRD group, and 23 genes on chromosomes 5 and 6 related to growth in the CSD group. Finally, we identified 17 genes on chromosome 12 related to environmental adaptation and body size with high homozygosity in both groups.
Conclusions
These results show how different management practices have impacted the level of genomic inbreeding in two Italian goat groups and could be useful to assist management in a low-input system while safeguarding the diversity of small populations
BOVITA: a first overview on genome-wide genetic diversity of Italian autochthonous cattle breeds
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