528 research outputs found

    Hierarchical structure of the Sicilian goats revealed by Bayesian analyses of microsatellite information

    Get PDF
    Genetic structure and relationship amongst the main goat populations in Sicily (Girgentana, Derivata di Siria, Maltese and Messinese) were analysed using information from 19 microsatellite markers genotyped on 173 individuals. A posterior Bayesian approach implemented in the program STRUCTURE revealed a hierarchical structure with two clusters at the first level (Girgentana vs. Messinese, Derivata di Siria and Maltese), explaining 4.8% of variation (AMOVA ФST estimate). Seven clusters nested within these first two clusters (further differentiations of Girgentana, Derivata di Siria and Maltese), explaining 8.5% of variation (AMOVA ФSC estimate). The analyses and methods applied in this study indicate their power to detect subtle population structure

    Beta-lactoglobulin polymorphism in Girgentana goat breed

    Get PDF
    Beta-lactoglobulin (b-lg) is a globular protein belonging to the lipocalin family. It is the major whey protein in the milk of ruminants. It is also present in the milk of most mammals but is lacking in rodents, lagomorphs and humans. A large number of variants have been reported for cow and sheep milk. Several studies have shown association between b-lg variants and milk production and composition, even if the results are not always concordant. In goat, no b-lg variants related with amino acid change have been characterized at DNA level, but some authors described the presence of polymorphisms in the 3’UTR and in the proximal promoter region. Mutations in the promoter region could be those most likely responsible for different level of gene expression. The aim of this work was to study the genetic polymorphism at DNA level of b-lg gene in Girgentana goat breed. A total of 238 genomic DNA samples of Girgentana breed were genotyped. A fragment of 709 bp, including 588 bp of proximal promoter region and 121 bp of exon 1, was amplified using primers GOAPF3 and GoatE1R2. PCR-RFLP procedure was used for fast detection of two single nucleotide substitutions as described by Graziano et al. (2003). The base substitutions originating the polymorphic sites consist of: 1. a transition T›C at position -341 and 2. a transition C›T at position -60. A FspBI PCR-RFLP protocol was used to detect the mutation -341 (T/C) and a SmaI PCR-RFLP protocol for the mutation -60 (C/T) of the proximal promoter region. The allelic frequencies and the Hardy-Weinberg equilibrium were estimated using the GENEPOP software. Girgentana goat breed shows no significant deviation from Hardy- Weinberg equilibrium for the allele frequencies found in both polymorphic sites considered. The genotypic frequencies for both mutations resulted in 0.65 (T/T), 0.33 (T/C) and 0.02 (C/C) for the position -341, and 0.82 (C/C), 0.17 (C/T) and 0.01 (T/T) for the position -60. These results are in agreement with the previous obtained by Graziano et al. (2003) in the same breed. Further analysis are in progress to investigate the possible effect of these variants on the expression of b-lg gene, on the milk protein composition and on milk production traits

    Application of Two-Dimensional Matched Filters to X-Ray Radiographic Flaw Detection and Enhancement

    Get PDF
    Detection and enhancement of low contrast flaws in radiographic images with high noise fields is an ongoing topic of research in nondestructive evaluation. In film radiography, the minimum detectable flaw thickness is controlled by the exposure characteristics and the flaw size in relation to the thickness of the part. The exposure characteristics determine the overall sensitivity and noise level, while the flaw thickness controls the contrast of the flaw image with respect to the background film density. Often it is difficult to generate optimal exposures when inspecting thick objects or complicated part geometries. This can result in noisy images due to the poor counting statistics of the photons as well as optical film densities that are suboptimal for visual interpretation. In addition, flaw contrast is often extremely low due to the flaw size or the poor orientation of crack-like flaws. The goal of the work presented in this paper is to demonstrate the utility of digital image processing using the matched filter for detecting and enhancing flaws in low-contrast, high-noise radiographic images. The basic theory of the matched filter will be presented along with its application to two-dimensional images, In addition several practical examples will be shown on simulated and real radiographs.</p

    Quasi-fission reactions as a probe of nuclear viscosity

    Full text link
    Fission fragment mass and angular distributions were measured from the ^{64}Ni+^{197}Au reaction at 418 MeV and 383 MeV incident energy. A detailed data analysis was performed, using the one-body dissipation theory implemented in the code HICOL. The effect of the window and the wall friction on the experimental observables was investigated. Friction stronger than one-body was also considered. The mass and angular distributions were consistent with one-body dissipation. An evaporation code DIFHEAT coupled to HICOL was developed in order to predict reaction time scales required to describe available data on pre-scission neutron multiplicities. The multiplicity data were again consistent with one-body dissipation. The cross-sections for touch, capture and quasi-fission were also obtained.Comment: 25 pages REVTeX, 3 tables, 13 figures, submitted to Phys. Rev

    The serum zinc concentration as a potential biological marker in patients with major depressive disorder

    Get PDF
    Despite many clinical trials assessing the role of zinc in major depressive disorder (MDD), the conclusions still remain ambiguous. The aim of the present clinical study was to determine and comparison the zinc concentration in the blood of MDD patients (active stage or remission) and healthy volunteers (controls), as well as to discuss its potential clinical usefulness as a biomarker of the disease. In this study 69 patients with current depressive episode, 45 patients in remission and 50 controls were enrolled. The zinc concentration was measured by electrothermal atomic absorption spectrometry (ET AAS). The obtained results revealed, that the zinc concentration in depressed phase were statistically lower than in the healthy volunteers [0.89 vs. 1.06 mg/L, respectively], while the zinc level in patients achieve remission was not significantly different from the controls [1.07 vs. 1.06 mg/L, respectively]. Additionally, among the patients achieve remission a significant differences in zinc concentration between group with and without presence of drug-resistance in the previous episode of depression were observed. Also, patients in remission demonstrated correlation between zinc level and the average number of depressive episodes in the last year. Serum zinc concentration was not dependent on atypical features of depression, presence of psychotic symptoms or melancholic syndrome, age, age of onset or duration of disease, number of episodes in the life time, duration of the episode/remission and severity of depression measured by the Hamilton Rating Scale for Depression (HDRS), and the Montgomery-Asberg Depression Rating Scale (MADRS). Concluding, our findings confirm the correlation between zinc deficit present in the depressive episode, and are consistent with the majority of previous studies. These results may also indicate that serum zinc concentration might be considered as a potential biological marker of MDD

    Freeze-out configuration properties in the 197Au + 197Au reaction at 23 AMeV

    Full text link
    Data from the experiment on the 197Au + 197Au reaction at 23 AMeV are analyzed with an aim to find signatures of exotic nuclear configurations such as toroid-shaped objects. The experimental data are compared with predictions of the ETNA code dedicated to look for such configurations and with the QMD model. A novel criterion of selecting events possibly resulting from the formation of exotic freeze-out configurations, "the efficiency factor", is tested. Comparison between experimental data and model predictions may indicate for the formation of flat/toroidal nuclear systems

    Cross Section Limits for the 208^{208}Pb(86^{86}Kr,n)293^{293}118 Reaction

    Full text link
    In April-May, 2001, the previously reported experiment to synthesize element 118 using the 208^{208}Pb(86^{86}Kr,n)293^{293}118 reaction was repeated. No events corresponding to the synthesis of element 118 were observed with a total beam dose of 2.6 x 1018^{18} ions. The simple upper limit cross sections (1 event) were 0.9 and 0.6 pb for evaporation residue magnetic rigidities of 2.00 TmT m and 2.12 TmT m, respectively. A more detailed cross section calculation, accounting for an assumed narrow excitation function, the energy loss of the beam in traversing the target and the uncertainty in the magnetic rigidity of the Z=118 recoils is also presented. Re-analysis of the primary data files from the 1999 experiment showed the reported element 118 events are not in the original data. The current results put constraints on the production cross section for synthesis of very heavy nuclei in cold fusion reactions.Comment: 7 pages, 2 figures. Submitted to EPJ

    The systematic study of the influence of neutron excess on the fusion cross sections using different proximity-type potentials

    Full text link
    Using different types of proximity potentials, we have examined the trend of variations of barrier characteristics (barrier height and its position) as well as fusion cross sections for 50 isotopic systems including various collisions of C, O, Mg, Si, S, Ca, Ar, Ti and Ni nuclei with 1N/Z<1.61\leq N/Z < 1.6 condition for compound systems. The results of our studies reveal that the relationships between increase of barrier positions and decrease of barrier heights are both linear with increase of N/ZN/Z ratio. Moreover, fusion cross sections also enhance linearly with increase of this ratio.Comment: 28 pages, 7 figures, 5 Table

    Charged pion production in 4496^{96}_{44}Ru+4496^{96}_{44}Ru collisions at 400A and 1528A MeV

    Full text link
    We present transverse momentum and rapidity spectra of charged pions in central Ru + Ru collisions at 400AA and 1528AA MeV. The data exhibit enhanced production at low transverse momenta compared to the expectations from the thermal model that includes the decay of Δ(1232)\Delta(1232)-resonances and thermal pions. Modification of the Δ\Delta-spectral function and the Coulomb interaction are necessary to describe the detailed shape of the transverse momentum spectra. Within the framework of the thermal model, the freeze-out radii of pions are similar at both beam energies. The IQMD model reproduces the shapes of the transverse momentum and rapidity spectra of pions, but the predicted absolute yields are larger than in the measurements, especially at lower beam energy.Comment: 12 pages, 11 figure
    corecore