114 research outputs found

    Shape dependence and anisotropic finite-size scaling of the phase coherence of three-dimensional Bose-Einstein condensed gases

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    We investigate the equilibrium phase-coherence properties of Bose-condensed particle systems, focusing on their shape dependence and finite-size scaling (FSS). We consider three-dimensional (3D) homogeneous systems confined to anisotropic L x L x L_a boxes, below the BEC transition temperature TcT_c. We show that the phase correlations develop peculiar anisotropic FSS for any T<TcT<T_c, in the large-LL limit keeping the ratio \lambda = L_a/L^2 fixed. This phenomenon is effectively described by the 3D spin-wave (SW) theory. Its universality is confirmed by quantum Monte Carlo simulations of the 3D Bose-Hubbard model in the BEC phase. The phase-coherence properties of very elongated BEC systems, \lambda>>1, are characterized by a coherence length \xi_a \sim A_t \rho_s/T where A_t is the transverse area and \rho_s is the superfluid density.Comment: 7 page

    Impact of long-term and short-term therapies on seminal parameters

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    Aim: The aim of this work was: i) to evaluate the prevalence of male partners of subfertile couples being treated with long/short term therapies for non andrological diseases; ii) to study their seminal profile for the possible effects of their treatments on spermatogenesis and/or epididymal maturation. Methods: The study group was made up of 723 subjects, aged between 25 and 47 years. Semen analysis was performed according to World Health Organization (WHO) guidelines (1999). The Superimposed Image Analysis System (SIAS), which is based on the computerized superimposition of spermatozoa images, was used to assess sperm motility parameters. Results: The prevalence of subjects taking pharmacological treatments was 22.7% (164/723). The prevalence was 3.7% (27/723) for the Short-Term Group and 18.9% (137/723) for the Long-Term Group. The subjects of each group were also subdivided into subgroups according to the treatments being received. Regarding the seminal profile, we did not observe a significant difference between the Long-Term, Short-Term or the Control Group. However, regarding the subgroups, we found a significant decrease in sperm number and progressive motility percentage in the subjects receiving treatment with antihypertensive drugs compared with the other subgroups and the Control Group. Conclusions: In the management of infertile couples, the potential negative impact on seminal parameters of any drugs being taken as Long-Term Therapy should be considered. The pathogenic mechanism needs to be clarified

    Adolescence and andrologist: An imperfect couple

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    Objective: The aims of this research were to study: a) the prevalence of male adolescents, aged between 10 and 19 years of age, referred to our Unit for an andrological assessment; b) the reasons (stated and subsequently modified) for referral; c) the prevalence of clinically diagnosed diseases.Materials and methods: A total of 2.855 subjects, referred to the Andrology Unit for a first examination, were retrospectively studied. For each adolescent, a medical history was taken and an andrological physical examination was carried out. Results: Prevalence was found to be 6.9% (197/2855). Subjects were divided into two groups according to age (A: ≤ 14 and B: ≥ 15 years). The original reason stated for their consultation was corrected by 11.7% of the subjects (23/197); this correction concerned almost all the Group B subjects (21/23 (91.3%) vs 2/23 (8.7%) of Group A; p < 0.01). Regarding sexual dysfunctions, a simple explanation of certain conditions reassured the subject in about 15% of the cases. Furthermore, the physical examination proved extremely useful, revealing clinical alterations in more than 60% of subjects. Conclusions: In conclusion, to date in Italy, the prevalence of adolescents among males referred to an Andrology Unit for assessment is very low. It is important to encourage adolescents to undergo andrological examination to enable identification of reproductive function and psycho-sexual disorders

    Comparative study of seminal parameters between samples collected in 1992 and samples collected in 2010

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    Objective: The aim of this study was to conduct a comparative study of semen quality in two large populations; one evaluated in 1992 and another in 2010, in order to evaluate any possible decline in male fertility due, at least in part, to environmental factors. Material and Methods: A total of 701 subjects in 1992 (TOTAL group 1992) and a total of 626 subjects in 2010 (TOTAL group 2010) were enrolled in our Andrology Unit. Each group was subdivided into 3 subgroups: Subfertile, Pathology and Control. Standard semen analysis was performed using the Superimposed Image Analysis System, according to WHO guidelines 1987 (for TOTAL group 1992) and WHO guidelines 1999 (for TOTAL group 2010). Results: The mean values of sperm number (concentration/ml as well as the total ejaculate) and progressive motility were significantly higher in TOTAL group 2010 than TOTAL group 1992. Atypical forms in TOTAL group 1992 semen samples were significantly lower than TOTAL group 2010. The mean age of TOTAL Group 2010 was significantly higher compared with TOTAL Group 1992. In particular, the mean age gap was more evident in Subfertile subjects. Conclusions: In conclusion, environmental factors have not determined a significant decline in seminal parameters in the past 18 years

    Impact of Cystic Fibrosis Transmembrane Regulator (CFTR) gene mutations on male infertility

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    Objective. The aim of this study was to evaluate the prevalence of most common mutations and intron 8 5T (IVS8-5T) polymorphism of CFTR gene in Italian: a) azoospermic males; b) non azoospermic subjects, male partners of infertile couples enrolled in assisted reproductive technology (ART) programs. Material and methods. We studied 242 subjects attending our Andrology Unit (44 azoospermic subjects and 198 non azoospermic subjects, male partners of infertile couples enrolled in ART programs). Semen analysis, molecular analysis for CFTR gene mutations and genomic variant of IVS8-5T polymorphic tract, karyotype and chromosome Y microdeletions, hormonal profile (LH, FSH, Testosterone) and seminal biochemical markers (fructose, citric acid and L-carnitine) were carried out. Results. The prevalence of the common CFTR mutations and/or the IVS8-5T polymorphism was 12.9% (4/31 cases) in secretory azoospermia, while in obstructive azoospermia was 84.6% (11/13 cases; in these, the most frequent mutations were the F508del, R117H and W1282X). Regarding the non azoospermic subjects, the prevalence of the CFTR and/or the IVS8-5T polymorphism was 11.1% (11/99 cases) in severe dyspermia, 8.1% (6/74 cases) in moderate dyspermia and finally 4.0% (1/25 cases) in normospermic subjects. Conclusions. This study confirms the highly significant prevalence of CFTR mutations in males with bilateral absence of the vas deferens or ejaculatory ducts obstruction compared with subjects with secretory azoospermia. Moreover, the significant prevalence of mutations in severely dyspermic subjects may suggest the possible involvement of CFTR even in the spermatogenic process. This could explain the unsatisfactory recovery of sperm from testicular fine needle aspiration in patients affected by genital tract blockage

    Archosauriform footprints in the Lower Triassic of Western Alps and their role in understanding the effects of the Permian-Triassic hyperthermal

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    The most accepted killing model for the Permian-Triassic mass extinction (PTME) postulates that massive volcanic eruption (i.e., the Siberian Traps Large Igneous Province) led to geologically rapid global warming, acid rain and ocean anoxia. On land, habitable zones were drastically reduced, due to the combined effects of heating, drought and acid rains. This hyperthermal had severe effects also on the paleobiogeography of several groups of organisms. Among those, the tetrapods, whose geographical distribution across the end-Permian mass extinction (EPME) was the subject of controversy in a number of recent papers. We here describe and interpret a new Early Triassic (?Olenekian) archosauriform track assemblage from the Gardetta Plateau (Briançonnais, Western Alps, Italy) which, at the Permian-Triassic boundary, was placed at about 11° North. The tracks, both arranged in trackways and documented by single, well-preserved imprints, are assigned to Isochirotherium gardettensis ichnosp. nov., and are here interpreted as produced by a non-archosaurian archosauriform (erytrosuchid?) trackmaker. This new discovery provides further evidence for the presence of archosauriformes at low latitudes during the Early Triassic epoch, supporting a model in which the PTME did not completely vacate low-latitude lands from tetrapods that therefore would have been able to cope with the extreme hot temperatures of Pangaea mainland

    Toward a Public MAGIC Gamma-Ray Telescope Legacy Data Portal

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    The MAGIC telescopes are one of the three major IACTs (Imaging Atmospheric Cherenkov Telescopes) for observation of gamma rays in the TeV regime currently operative. MAGIC functions since 2003, and has published data from more than 60 sources, mostly blazars. MAGIC already provides astronomical exttt.fits files with basic final scientific products such as spectral energy distributions, light curves and skymaps from published results. In future, the format of the files can be complemented with further relevant information to the community: a) by including the full multi-wavelength dataset enclosed in a publication, b) providing data in alternative easy-to-use formats such as ASCII or ECSV, which are accessible with other commonly used packages such as extttastropy or extttgammapy. Finally, besides high level products, activities have started to provide photon event lists and instrument response functions in a format such that scientists within and outside the community are allowed to perform higher level analysis. A second aim is to provide a full legacy of MAGIC data. This contribution will illustrate the achievements and plans of this activity

    Estimating abundance and habitat suitability in a micro-endemic snake: the Walser viper

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    Recently described species suffer lack of information that hampers setting up appropriate conservation strategies. The situation is particularly complex with micro-endemic snakes, for which detection and monitoring are particularly challenging. The Walser viper Vipera walser is a recently described snake inhabiting a small area of the SW Italian alps. We combined information on species distribution with repeated monitoring to identify the areas most suitable for the species, and to obtain estimates of species abundance. Species distribution models were used to identify the topographical, climatic, and land-cover features related to the occurrence of vipers. Furthermore, repeated transects and N-mixture models were used to estimate abundance and to identify factors related to the variation of abundance. The available data suggested that the species has a disjunct range, with a Northern range of ~45 km2 , and a southern range of ~225 km2. Distribution models suggested that vipers are associated with areas with open egetation,altitude between 1300 and 2300 m, high precipitation, low forest cover, low slope, and southern aspect. N-mixture models confirmed very low detection probability of these vipers, and suggested that the species has a low abundance,with the highest abundance in south-facing plots. We provide the first quantitative information on habitats and abundance variation for Walser vipers. The broad confidence intervals of abundance estimates exemplify the complexity of providing range-wide measures of abundance for secretive species. Given the narrow range of these vipers, continuous monitoring is required to understand how they respond to ongoing environmental changes in mountainous areas
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