478 research outputs found

    Time-resolved carrier dynamics and electron-phonon coupling strength in proximized weak ferromagnet-superconductor nanobilayers

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    We present our femtosecond optical pump-probe studies of proximized ferromagnet-superconductor nanobilayers. The weak ferromagnetic nature of a thin NiCu film makes it possible to observe the dynamics of the nonequilibrium carriers through the near-surface optical reflectivity change measurements. The subpicosecond biexponential reflectivity decay has been identified as electron-phonon Debye and acoustic phonon relaxation times, and the decay of Debye phonons versus temperature dependence was used to evaluate the electron-phonon coupling constants for both the pure Nb and proximized Nb/NiCu heterostructures down to low temperatures. We have also demonstrated that the NiCu overlay on top of Nb dramatically reduced the slow, bolometric component of the photoresponse component, making such bilayers attractive for future radiation detector applications

    Effect of Calving Interval on Milk Yield in Italian Buffalo Population

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    The objective of this study was to investigate the effect of the previous calving intervals (CI) on milk yield (MY) in the current lactation for the Italian buffalo breed population.Data for 86,585 lactation records from the Italian Buffalo Breeders Association database, were analyzed. MY BLUP-estimates were obtained by including in the Animal Model the fixed effects of age-parity, previous CI, and herd-contemporary-group. The MY solutions for the months of CI were analyzed with the linear regression model where CI in months was the explanatory variable. 59.66% of the lactation records had CI between 11 and 14 months. 37.91 % of the lactation records were distributed between 15 and 24 months. The smaller percentage of records showed CI greater than 24 months. This CI distribution may be, in part, the result of herd management strategies. Dairy producers try to shorten the CI of their herd in order to get the most profit from early conceptions of the buffalo. The regression model and its parameters were statistically significant. The coefficient of determination was equal to 0.58. The intercept was equal to 72.42 kg; and the linear coefficient (b) was equal to -3.43. The negative value of b denotes a negative effect of CI on MY. This result indicates that there is a negative linear relationship between previous CI and MY in the current lactation. Therefore, shorten the CI may increase the profits of the farm through higher MY, because it has less of a negative effect on MY than longer CI

    Genetic Parameters and Sire Ranking for the Adjusted Estimate of Mozzarella Cheese Production in Italian Mediterranean Buffalo

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    The objectives of this study were to investigate the effect of adjusting mozzarella cheese production (APKM) compare to the unadjusted PKM on genetic parameters and sire ranking in Italian buffalo. 337,158 lactation records at 270d, from years 1997 to 2014, up to fifth parity, of 136,525 animals were analyzed. Estimated Breeding Values (EBVs) for APKM and PKM were predicted by BLUP-Animal Model with the fixed effects of age-parity, days-open, and contemporary-group; and the random factors of animal, permanent environmental and residuals. APKM showed lower heritability (0.23) than that of PKM (0.31) which might be due to the lower genetic correlation between APKM and milk yield (MY) (0.09) compared to that of PKM with MY (0.25). APKM positively changed sire ranking with increasing rank of sire with positive EBVs of Protein and Fat percentage, and decreasing rank of sire with negative EBVs of Protein and Fat percentage. Due to the larger correlation between PKM and MY, by selecting through the PKM, one risk is to increasing the number of buffalo that produce more milk, not optimal for making mozzarella cheese. Whereas, genetic selection through the APKM will increase the number of high-yielding buffalo with positive EBVs for Protein and Fat percentage

    Effect of parentage misidentification on estimates of genetic parameters for milk yield in the Mediterranean Italian buffalo population

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    The objective of this study was to evaluate the effect of parentage misidentification on estimation of genetic parameters for the Italian buffalo population for milk yield from 45,194 lactation records of 23,104 Italian buffalo cows. Animals were grouped into 10 data sets in which sires and dams were DNA identified, or reported from the pedigree, or unknown. A derivativefree restricted maximum likelihood method was used to estimate components of variance with a repeatability model. The model contained age at calving nested within parity and days from calving to conception as linear covariates, herd-year-seasons as fixed effects, and additive genetic, permanent environmental, and temporary environmental effects as random effects. Estimates of heritability (±SE) ranged from 0.00 ± 0.099 (sires and dams as reported in the pedigree) to 0.39 ± 0.094 (sires DNA identified and dams as reported in the pedigree). When identification of sires was as reported in the pedigree, estimates of heritability were close to zero. These small estimates indicate that a large proportion of reported paternity is incorrect. When sires are unknown and dams are DNA identified, the proportion of variance due to sires seems to be captured in the estimate of permanent environmental variance as a fraction of phenotypic variance. Therefore, as heritability decreased, permanent environmental variance increased about the same amount. Data sets with dams identified from pedigree and sires DNA identified showed the largest estimate of heritability (0.39), which was essentially the same as when dams were DNA identified (0.38). This result supports that most dams are correctly reported from the pedigree. Genetic progress should be much greater with bulls DNA identified because of greater heritability, but without artificial insemination and progeny testing, progress would be slow and would depend mostly on selection of sires based on dam estimated breeding values. Implementation of artificial insemination programs and DNA testing to identify sires are the keys for increasing genetic progress in the Italian buffalo population

    Parallel bug-finding in concurrent programs via reduced interleaving instances

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    Concurrency poses a major challenge for program verification, but it can also offer an opportunity to scale when subproblems can be analysed in parallel. We exploit this opportunity here and use a parametrizable code-to-code translation to generate a set of simpler program instances, each capturing a reduced set of the original program’s interleavings. These instances can then be checked independently in parallel. Our approach does not depend on the tool that is chosen for the final analysis, is compatible with weak memory models, and amplifies the effectiveness of existing tools, making them find bugs faster and with fewer resources. We use Lazy-CSeq as an off-the-shelf final verifier to demonstrate that our approach is able, already with a small number of cores, to find bugs in the hardest known concurrency benchmarks in a matter of minutes, whereas other dynamic and static tools fail to do so in hours

    Proximity effect in planar superconducting tunnel junctions containing Nb/NiCu superconductor/ferromagnet bilayers

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    We present experimental results concerning both the fabrication and characterization of superconducting tunnel junctions containing superconductor/ferromagnet (S/F) bilayers made by niobium (S) and a weak ferromagnetic Ni0.50Cu0.50 alloy. Josephson junctions have been characterized down to T=1.4 K in terms of current-voltage I-V characteristics and Josephson critical current versus magnetic field. By means of a numerical deconvolution of the I-V data the electronic density of states on both sides of the S/F bilayer has been evaluated at low temperatures. Results have been compared with theoretical predictions from a proximity model for S/F bilayers in the dirty limit in the framework of Usadel equations for the S and F layers, respectively. The main physical parameters characterizing the proximity effect in the Nb/NiCu bilayer, such as the coherence length and the exchange field energy of the F metal, and the S/F interface parameters have been also estimated

    IL MUSEO DELL’OSSERVATORIO VESUVIANO E IL SUO PUBBLICO. ANNI 2005 - 2009

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    The Vesuvius Observatory, first volcanological observatory in the world, was built in 1841 by King Ferdinand II of Bourbon. It is now the Naples section of the National Institute of Geophysics and Volcanology (INGV). Since its foundation it has been not only a reference point for national and international scientific community, but also a place of information and dissemination for the population in the field of research and monitoring of volcanic phenomena. Always museum activities, guided tours through the collections of scientific instruments, rocks and minerals have been carried out in it. Since 2000 scientific and historical collections located into the old building of Vesuvius Observatory have been organized in the exhibition "Vesuvius: 2000 years of observations", which describes the eruptive history of Somma-Vesuvius, with the aim of providing updated information about monitoring of active volcanoes, on eruptive phenomena and related hazards, educating the population of areas exposed to volcanic hazards. The museum path is targeted to public of any geographical origin and cultural background and could be considered a journey through the history of volcanology from the beginning until the present day. In the exhibition, Vesuvius is the backdrop to an exhibition in which purely scientific elements coexist with historical, archaeological, literary, artistic aspects, thanks to the support of images, documents such as the geological map of Henry James Johnston-Lavis and the book "Campi Flegrei" by William Hamilton, specimens of rocks and minerals and old scientific instruments, used in the past for monitoring volcanic activity, including the first electromagnetic seismograph made by Luigi Palmieri. The first part of this work is focussed on the description of the existing exhibition. Since 2000 the statistical survey of the public of the museum has been carried out through an evaluation procedure form. The findings relate to the monthly and annual attendance, geographical origin and kind of visitors. In the second part of this work results for the five years from 2005 to 2009 are described. The characterization of different audiences in the museum means that, from time to time, the path of the visit could be arranged according to the expectations and needs of visitors; in this context, the museum educator plays the delicate role of mediator, with accurate language, between the contents of the museum and those who interact with it

    Tumor-on-a-chip platforms to study cancer-immune system crosstalk in the era of immunotherapy

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    Immunotherapy is a powerful therapeutic approach able to re-educate the immune system to fight cancer. A key player in this process is the tumor microenvironment (TME), which is a dynamic entity characterized by a complex array of tumor and stromal cells as well as immune cell populations trafficking to the tumor site through the endothelial barrier. Recapitulating these multifaceted dynamics is critical for studying the intimate interactions between cancer and the immune system and to assess the efficacy of emerging immunotherapies, such as immune checkpoint inhibitors (ICIs) and adoptive cell-based products. Microfluidic devices offer a unique technological approach to build tumor-on-a-chip reproducing the multiple layers of complexity of cancer-immune system crosstalk. Here, we seek to review the most important biological and engineering developments of microfluidic platforms for studying cancer-immune system interactions, in both solid and hematological tumors, highlighting the role of the vascular component in immune trafficking. Emphasis is given to image processing and related algorithms for real-time monitoring and quantitative evaluation of the cellular response to microenvironmental dynamic changes. The described approaches represent a valuable tool for preclinical evaluation of immunotherapeutic strategies

    Quasiparticles energy relaxation times in NbN/CuNi nanostripes from critical velocity measurements

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    The dynamic instability of the moving vortex lattice at high driving currents in NbN/CuNi-based and NbN nanostripes designed for optical detection has been studied. By applying the model proposed by Larkin and Ovchinnikov [Zh. Eksp. Teor. Fiz. 68, 1915 (1975)], from the critical velocity v∗ for the occurrence of the instability, it was possible to estimate the values of the quasiparticle relaxation times τE. The results show that the NbN/CuNi-based devices are characterized by shorter values of τE compared to that of NbN
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