Natural History of Diabetes

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CFD analysis of the fuel-air mixture formation process in passive prechambers for use in a high-pressure direct injection (HPDI) Two-stroke engine

The research on two-stroke engines has been focused lately on the development of direct injection systems for reducing the emissions of hydrocarbons by minimizing the fuel shortcircuiting. Low temperature combustion (LTC) may be the next step to further improve emissions and fuel consumption; however, LTC requires unconventional ignition systems. Jet ignition, i.e., the use of prechambers to accelerate the combustion process, turned out to be an effective way to perform LTC. The present work aims at proving the feasibility of adopting passive prechambers in a high-pressure, direct injection, two-stroke engine through non-reactive computational fluid dynamics analyses. The goal of the analysis is the evaluation of the prechamber performance in terms of both scavenging efficiency of burnt gases and fuel/air mixture formation inside the prechamber volume itself, in order to guarantee the mixture ignitability. Two prechamber geometries, featuring different aspect ratios and orifice numbers, were investigated. The analyses were replicated for two different locations of the injection and for three operating conditions of the engine in terms of revolution speed and load. Upon examination of the results, the effectiveness of both prechambers was found to be strongly dependent on the injection setup

Morphological characterization of the Amiata donkey breed through the data reported in the Anagraphic Register

The Anagraphic Register of the Amiata donkey breed has been established in 1993, and is maintained by the association of breeders of the Grosseto province (APA-GR). Being an endangered breed, subjects with unknown pedigree have been allowed to be recorded, provided that females scored at least 60 and males at least 75 points on morphological evaluation. Recording is still open for females, whereas it has been closed in 1997 for stallions. In the present work, we have investigated the morphological structure of the Amiata donkey through the data reported in the Anagraphic Register. This last was started recently and was maintained on paper only, meaning that it inevitably includes a certain degree of incompleteness. The morphological records of 74 unrelated Amiata donkeys (62 females and 12 males) were collected at the APA-GR in 2005. For each animal the following biometrical data was available: 10 individual scores (from 1 to 10) for coat colour, head shape, neck, withers, shoulders, back, back-lumbar line, limbs and plumbs, walking and foot, evaluated by certificated experts of the breed; in addition, measurements of withers height, chest and cannon circumference were individually reported. As an index of body compactness, the ratio chest/cannon circumference was calculated from data. One-way analysis of variance was used to test the differences between male and females for total scores and morphological measurements. Data were analysed by JMP software version 5.0 of SAS Inst. (2002). No significant differences were observed among females and males: Mean (± s.d.) withers height (WH) were 129.0 ± 3.2 cm in females and 131.8 ± 3.1 cm in males. Chest circumference (CH) were 148.4 ± 5.1 cm and of 150.8 ± 5.5 cm, for males and females respectively, and cannon circumference (CC) were 16.6 ± 1.2 cm and 17.1 ± 0.4 cm, for males and females respectively. The ten evaluation scores were added up for each animal; means were 72.4 ± 6.2 in females (range 61- 88) and 77.2 ± 3.0 (range 71-80) in males. The ratio CH/CC, an index of body compactness, was 0.11 ± 0.01 in males (range 0.11-0.12) and 0.11 ± 0.01 in females (range 0.09-0.13). All these measurements indicate low variability among individuals as well as limited sexual dimorphism

Demographic genetics of the endangered Amiata donkey breed

The demogenetic structure of the Amiata donkey, an endangered breed from Central Italy, was investigated using information from pedigrees. Genealogical data of 602 donkeys reared in Tuscany were recorded in a database and analysed by the computer package ENDOG. Population size increased from 89 subjects in 1995 to 503 (129 males and 374 females) in 2005. Animals were distributed among 152 herds, but the effective number of herds was 21, suggesting that a small number of herds provided stallions for the entire breed. The maximum number of traced generation was 4, the mean maximum generation was 1.14, the mean com- plete generation was 0.53, and the mean equivalent generation was 0.78. The average relatedness coeffi- cient (AR) in the 503 alive animals was 0.94% while the mean F was 0.29% so the effective population size was 172.41. Among 24 animals with a 4-generation history, 3 (12.5%) were 25% inbred. Although the incompleteness of genealogical information did not permit accurate inference of the current values of popu- lation genetic parameters, the present work represents a first step towards an efficient management of the breed

Molecular Coancestry and Classical Genetic Distances Depict Different Patterns of Relationship Among Sheep Breeds from Southern Italy

Several molecular-based parameters, such as similarity indexes, can be adopted to optimize the management of genetic diversity in conservation programmes. From simulated data, Oliehoek et al. (2006) showed that molecular coancestry (Toro et al., 2002) is, among the possible relatedness estimators, the one that performs better in structured populations, such as populations in need of conservation usually are. Several studies have, therefore, proposed the use of molecular coancestry coefficients as a measure of genetic variability and as a useful tool for conservation of endangered breeds (Ciampolini et al., 2007; Glowatzki-Mullis et al., 2009). Here we report the results obtained evaluating within- and between-breed molecular coancestry (Toro et al., 2002), together with other classical genetic parameters, for two insular sheep breeds (Sarda from Sardinia and Comisana from Sicily), recently spread almost all over Italy, and for five local rare sheep breeds from Southern Italy

Haplotype association analysis of meat quality traits at the bovine PRKAG3 locus

The current study presents the results of a preliminary haplotype association analysis at the bovine PRKAG3 locus with meat quality traits in the Chianina breed. No significant association was shown between haploid haplotypes (or diplotypes) and phenotypical traits after applying a Bonferroni correction for multiple comparison. Nonetheless, data from Longissimus dorsi muscle suggest the presence of a statistically non-significant trend toward an influence of the PRKAG3 haploid haplotypes on meat colour (a*) and water holding capacity (M/T) traits, as confirmed also by diplotype-based association analysis. A less clear set of results was observed for the Triceps brachii and Semitendinosus muscles

The Genetic resistence to Coccidia in Appenninica sheep

The study was conducted on a single herd of Appenninica sheep breed situated in Tuscany (Italy) from April to November 2004 on 108 sheep with the aim to identify the most resistant subjects to Coccidia. Moreover, the presence of gastro-intestinal Strongylids, Dicrocoelium sp. Moniezia spp.Strongyloides sp. and Trichuris sp. was also evaluated. Sheep selection may be based on OPG in adults animals, as it appears to be an indicator of sheep resistance to Coccidia. Before incorporating the parameter into breeding programmes, however, it is necessary to better appraise the degree of infestation of the other parasites as it may be difficult to select simultaneously for resistance to Coccidia and Strongylids unless the genetic correlation between these two traits is calculated and a selection index approach is used

Genome-Wide Analysis Reveals Selection Signatures Involved in Meat Traits and Local Adaptation in Semi-Feral Maremmana Cattle

The Maremmana cattle is an ancient Podolian-derived Italian breed raised in semi-wild conditions with distinctive morphological and adaptive traits. The aim of this study was to detect potential selection signatures in Maremmana using medium-density single nucleotide polymorphism array. Putative selection signatures were investigated combining three statistical approaches designed to quantify the excess of haplotype homozygosity either within (integrated haplotype score, iHS) or among pairs of populations (Rsb and XP-EHH), and contrasting the Maremmana with a single reference population composed of a pool of seven Podolian-derived Italian breeds. Overall, the three haplotype-based analyses revealed selection signatures distributed over 19 genomic regions. Of these, six relevant candidate regions were identified by at least two approaches. We found genomic signatures of selective sweeps spanning genes related to mitochondrial function, muscle development, growth, and meat traits (SCIN, THSD7A, ETV1, UCHL1, and MYOD1), which reflects the different breeding schemes between Maremmana (semi-wild conditions) and the other Podolian-derived Italian breeds (semi-extensive). We also identified several genes linked to Maremmana adaptation to the environment of the western-central part of Italy, known to be hyperendemic for malaria and other tick-borne diseases. These include several chemokine (C-C motif) ligand genes crucially involved in both innate and adaptive immune responses to intracellular parasite infections and other genes playing key roles in pulmonary disease (HEATR9, MMP28, and ASIC2) or strongly associated with malaria resistance/susceptibility (AP2B1). Our results provide a glimpse into diverse selection signatures in Maremmana cattle and can be used to enhance our understanding of the genomic basis of environmental adaptation in cattle

Molecular characterization of the Montecristo feral goats in the Mediterranean context

The Montecristo wild goat is an endangered feral population occurring on the homonymous island in the Tuscan Archipelago since a long time. The origins of Montecristo goats are still debated, with authors dating their introduction either back to Neolithic times or between the 6th and 13th century of the Common Era. To investigate the evolutionary history and relationships of this population we assembled a 50K SNP dataset including 55 Mediterranean breeds and two nuclei of Montecristo goats sampled on the island and from an ex situ conservation project on the Italian mainland, respectively. Diversity levels, gene flow, population structure and relationships were assessed through multiple approaches. The insular population scored the lowest values of both observed and expected heterozygosity, highlighting reduced genetic variation, while the ex situ nucleus highlighted a less severe reduction. Multivariate statistics, Neighbour-network and population structure analyses clearly separated the insular nucleus from all other breeds, but also the two Montecristo populations from each other. Treemix software analysis pinpointed possible genetic inputs received by the two Montecristo goat nuclei from different sources, while Runs Of Homozygosity (ROHs) indicated an ancient bottleneck/founder effect in the insular population and recent inbreeding in the ex situ one. Overall, our results suggest that Montecristo goats experienced several demographic fluctuations combined with admixture events over time, and highlighted a noticeable differentiation between the two nuclei. This evidence can serve as a starting point to implement marker-assisted conservation plans for the endangered Montecristo feral goat