Superfluid to Bose-glass transition in a 1D weakly interacting Bose gas

We study the one-dimensional Bose gas in spatially correlated disorder at zero temperature, using an extended density-phase Bogoliubov method. We analyze in particular the decay of the one-body density matrix and the behaviour of the Bogoliubov excitations across the phase boundary. We observe that the transition to the Bose glass phase is marked by a power-law divergence of the density of states at low energy. A measure of the localization length displays a power-law energy dependence in both regions, with the exponent equal to -1 at the boundary. We draw the phase diagram of the superfluid-insulator transition in the limit of small interaction strength.Comment: 4 pages, 4 figure

Molecular genetics of coat colour in pigs

Coat colour in Sus scrofa has been the matter of pioneering genetics studies carried out at the beginning of the last century. Since then, classical genetics studies have assumed that several loci affect this trait in pigs. With the advent of molecular genetics it was possible to identify genes and mutations affecting coat colours and patterns in pigs. Variability in several genes have been shown to affect pigmentation in this species. However, only two of them might play major roles in determining coat colour variation in Mediterranean pig breeds or populations: melanocortin 1 receptor (MC1R, Extension locus) and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT, Dominant White locus). Other genes (ASIP, TYRP1, EDNRB, KITLG and OCA2) might affect coat colour in few breeds/populations or could modify the effect of the two major genes. Polymorphisms in the MC1R and KIT genes can be also used to authenticate mono-breed products obtained from local pig breeds

Mean-field phase diagram of the 1-D Bose gas in a disorder potential

We study the quantum phase transition of the 1D weakly interacting Bose gas in the presence of disorder. We characterize the phase transition as a function of disorder and interaction strengths, by inspecting the long-range behavior of the one-body density matrix as well as the drop in the superfluid fraction. We focus on the properties of the low-energy Bogoliubov excitations that drive the phase transition, and find that the transition to the insulator state is marked by a diverging density of states and a localization length that diverges as a power-law with power 1. We draw the phase diagram and we observe that the boundary between the superfluid and the Bose glass phase is characterized by two different algebraic relations. These can be explained analytically by considering the limiting cases of zero and infinite disorder correlation length.Comment: 10 pages, 10 figure

Mutations in the bovine prolactin receptor (PRLR) gene: allele and haplotype frequencies in the Reggiana cattle breed

AbstractProlactin receptor (PRLR) is a member of the cytokine receptor superfamily. PRLR exerts its functions binding three types of ligands (prolactin, placental lactogen and growth hormone) invol..

Analysis of the electrical and thermal behaviour of Li-ion batteries using 0D and 3D-CFD approaches with validation on experimental data

Due to their characteristics, lithium-ion cells are the reference in the construction of a battery pack for electric vehicles (EVs). Despite this, their use is strongly affected by the operating temperature because the materials they are made of are thermally stable only in a relatively limited range around ambient temperature. Cell modelling and simulation become therefore essential in the design of the cell, of the battery pack and of its auxiliary systems to optimize performance while maintaining sufficient safety margins. In the present study, two zero-dimensional equivalent circuit models of a commercial Li-ion cell are developed and tuned in order to predict the electrical and thermal behaviour of the cell. The models are validated and compared with experimental data found in the scientific literature referring to both dynamic and static tests. This comparison shows the importance of tuning the model parameters, which are decisive for the accuracy of the simulation. Using a commercial tool dedicated to battery modelling, a three-dimensional model is then developed to investigate the electrical and thermal behaviour of the cell from a spatial point of view. The results obtained are aligned with those found in the scientific literature. With the present work, it has been possible to simulate and analyse the global behaviour of the cell (0D model) as well as its detailed behaviour (3D model) using relatively modest computational resources, thus constituting a solid base for more complex modelling such as that of a battery pack and its cooling system

Identification of mutations in the bovine KIT gene, a candidate for the Spotted locus in cattle

AbstractIn mammals, abnormal migration of melanoblasts from the neural crest during embryonic development may be the reason of the pielbaldism phenotype that is a mixture of pigmented and unpigmented areas in the coat. Several cattle breeds, like for example Holstein, show the piebald spotted coat colour phenotype, that, according to crossbreeding studies, is due to a recessive allele (s), member of the allele series of the Spotted (S) locus. Dominant alleles at this locus act as suppressors of the spotted pattern and produce uniformly pigmented animals while others determine the colour-sided pattern known, for example, in the Hereford breed. The bovine v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene (KIT) gene was localized in the region of chromosome 6 where the Spotted locus was mapped. KIT plays a major role during the embryonic development in directing the migration of the melanoblasts from the neural crest. Mutations in this gene cause different coat colour patterns in mouse and human. In pigs..

Nero Siciliano pig: analysis of coat colour affecting genes and perspectives for breed traceability

Nero Siciliano is an autochthonous pig breed reared in the internal areas of Sicily region mainly in the Nebrodi mountains. The animals are usually completely black with a dorsal stripe but a few present white portions mainly in the face or in the fore legs. According to the increased requests of the consumers for local and typical products, meat and cured products of Nero Siciliano pigs are sold at a higher price compared to other pig products. Thus there is the need to guarantee both consumers and the whole Nero Siciliano production chain from possible frauds. The identification and/or use of DNA markers that may be breed specific could make it possible to establish breed traceability and authenticity systems for the products obtained with this local pig breed. Mutations in coat colour genes have been already described and utilized for porcine breed traceability. In this trial we analysed mutations identified in two coat colour affecting genes, the melanocortin 1 receptor (MC1R) and the v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene (KIT), with the aim to characterize the Nero Siciliano pig at these loci and provide useful information to establish authenticity systems for the meat products. Fragment analysis of PCR products and PCRRFLP methods were used to identify the polymorphic sites that can distinguish known alleles at these two loci in 104 Nero Siciliano pigs. Four alleles were identified at the MC1R locus: the two dominant black alleles (ED2, frequency of 0.673; ED1, 0.187), allele EP (0.106) and the recessive e allele (0.034). The results showed that different alleles were observed at this locus, polymorphisms at the MC1R gene cannot be used for product traceability and authentication of this breed. As regards the KIT locus, all the animals were negative for the splice site mutation of exon/intron 17. Thus, meat of Nero Siciliano pigs can be distinguished from meat of white pigs that are positive for this polymorphic site. Moreover, at this locus only 4 pigs showed the 3'-5' duplication breakpoint suggesting that they carried the Ip allele. Studies are in progress to evaluate the effect of this allele on coat colour phenotypes in Nero Siciliano pig

Coat colours in the Massese sheep breed are associated with mutations in the agouti signalling protein (ASIP) and melanocortin 1 receptor (MC1R) genes

Massese is an Italian dairy sheep breed characterized by animals with black skin and horns and black or apparent grey hairs. Owing to the presence of these two coat colour types, this breed can be considered an interesting model to evaluate the effects of coat colour gene polymorphisms on this phenotypic trait. Two main loci have been already shown to affect coat colour in sheep: Agouti and Extension coding for the agouti signalling protein (ASIP) and melanocortin 1 receptor (MC1R) genes, respectively. The Agouti locus is affected by a large duplication including the ASIP gene that may determine the Agouti white and tan allele (AWt). Other disrupting or partially inactivating mutations have been identified in exon 2 (a deletion of 5 bp, D5; and a deletion of 9 bp, D9) and in exon 4 (g.5172T.A, p.C126S) of the ASIP gene. Three missense mutations in the sheep MC1R gene cause the dominant black ED allele (p.M73K and p.D121N) and the putative recessive e allele (p.R67C). Here, we analysed these ASIP and MC1R mutations in 161 Massese sheep collected from four flocks. The presence of one duplicated copy allele including the ASIP gene was associated with grey coat colour (P59.4E-30). Almost all animals with a duplicated copy allele (37 out of 41) showed uniform apparent grey hair and almost all animals without a duplicated allele (117 out of 120) were completely black. Different forms of duplicated alleles were identified in Massese sheep including, in almost all cases, copies with exon 2 disrupting or partially inactivating mutations making these alleles different from the AWt allele. A few exceptions were observed in the association between ASIP polymorphisms and coat colour: three grey sheep did not carry any duplicated copy allele and four black animals carried a duplicated copy allele. Of the latter four sheep, two carried the ED allele of the MC1R gene that may be the cause of their black coat colour. The coat colour of all other black animals may be determined by non-functional ASIP alleles (non-agouti alleles, Aa) and in a few cases by the ED Extension allele. At least three frequent ASIP haplotypes ([D5:g.5172T], [N:g.5172A] and [D5:g.5172A]) were detected (organized into six different diplotypes). In conclusion, the results indicated that coat colours in the Massese sheep breed are mainly derived by combining ASIP and MC1R mutations

Evaluation of the single jet flow rate for a multi-hole GDI nozzle

Fuel injectors featuring differentiated hole-to-hole dimensions improve the fuel distribution in the cylinder ensuring a more efficient and cleaner combustion for GDI (Gasoline Direct Injection) engines. A proper diagnostic system able to detect the actual fuel flow rate exiting each hole of a GDI nozzle is requested in order to optimize the matching between the spray and the combustion chamber. Measuring the spray impact force of a single plume allows the detection of the momentum flux exiting the single hole and, under appropriate hypotheses, the evaluation of the corresponding mass flow rate time-profile. In this paper two methodologies for the hole-specific flow rate evaluation, both based on the spray momentum technique, were applied to two different GDI nozzles, one featuring equal hole dimensions and one with two larger holes. Three different energizing times at 100 bar of fuel pressure were tested in order to cover a wide range of operating conditions. The results were validated in terms of injected mass by means of a proper device able to collect and weigh the fuel injected by each single nozzle hole, and in terms of mass flow rate using a Zeuch-method flow meter as reference. Both the proposed methodologies showed an excellent accuracy in the fuel amount detection with percentage error lower than 5% for standard energizing times and lower than 10% for very short injections working in ballistic conditions. The mass flow rate time-profile proved a good accuracy in the detection of the start and end of injection and the static flow rate level

Investigation of ABO Gene Variants across More Than 60 Pig Breeds and Populations and Other Suidae Species Using Whole-Genome Sequencing Datasets

Polymorphisms in the human ABO gene determine the major blood classification system based on the three well-known forms: A; B; and O. In pigs that carry only two main alleles in this gene (A and O), we still need to obtain a more comprehensive distribution of variants, which could also impact its function. In this study, we mined more than 500 whole-genome sequencing datasets to obtain information on the ABO gene in different Suidae species, pig breeds, and populations and provide (i) a comprehensive distribution of the A and O alleles, (ii) evolutionary relationships of ABO gene sequences across Suidae species, and (iii) an exploratory evaluation of the effect of the different ABO gene variants on production traits and blood-related parameters in Italian Large White pigs. We confirmed that allele O is likely under balancing selection, present in all Sus species investigated, without being fixed in any of them. We reported a novel structural variant in perfect linkage disequilibrium with allele O that made it possible to estimate the evolutionary time window of occurrence of this functional allele. We also identified two single nucleotide polymorphisms that were suggestively associated with plasma magnesium levels in pigs. Other studies can also be constructed over our results to further evaluate the effect of this gene on economically relevant traits and basic biological functions