498 research outputs found

    Inelastic scattering of broadband electron wave packets driven by an intense mid-infrared laser field

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    Intense, 100 fs laser pulses at 3.2 and 3.6 um are used to generate, by multi-photon ionization, broadband wave packets with up to 400 eV of kinetic energy and charge states up to Xe+6. The multiple ionization pathways are well described by a white electron wave packet and field-free inelastic cross sections, averaged over the intensity-dependent energy distribution for (e,ne) electron impact ionization. The analysis also suggests a contribution from a 4d core excitation in xenon

    Function and fiber-type specific distribution of hsp60 and αb-crystallin in skeletal muscles: Role of physical exercise

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    Skeletal muscle is a plastic and complex tissue, rich in proteins that are subject to continuous rearrangements. Skeletal muscle homeostasis can be affected by different types of stresses, including physical activity, a physiological stressor able to stimulate a robust increase in different heat shock proteins (HSPs). The modulation of these proteins appears to be fundamental in facili-tating the cellular remodeling processes related to the phenomenon of training adaptations such as hypertrophy, increased oxidative capacity, and mitochondrial activity. Among the HSPs, a special attention needs to be devoted to Hsp60 and αB-crystallin (CRYAB), proteins constitutively expressed in the skeletal muscle, where their specific features could be highly relevant in understanding the impact of different volumes of training regimes on myofiber types and in explaining the complex picture of exercise-induced mechanical strain and damaging conditions on fiber pop-ulation. This knowledge could lead to a better personalization of training protocols with an opti-mal non-harmful workload in populations of individuals with different needs and healthy status. Here, we introduce for the first time to the reader these peculiar HSPs from the perspective of exercise response, highlighting the control of their expression, biological function, and specific distribution within skeletal muscle fiber-types

    Sildenafil Reduces Expression and Release of IL-6 and IL-8 Induced by Reactive Oxygen Species in Systemic Sclerosis Fibroblasts

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    Oxidative stress linked to vascular damage plays an important role in the pathogenesis of systemic sclerosis (SSc). Indeed, vascular damage at nailfold capillaroscopy in patients with Raynaud’s Phenomenon (RP) is a major risk factor for the development of SSc together with the presence of specific autoantiobodies. Here, we investigated the effects of the phosphodiesterase type 5 inhibitor (PDE5i) sildenafil, currently used in the management of RP, in modulating the proinflammatory response of dermal fibroblasts to oxidative stress in vitro. Human fibroblasts isolated from SSc patients and healthy controls were exposed to exogenous reactive oxygen species (ROS) (100 µM H2O2), in the presence or absence of sildenafil (1 µM). Treatment with sildenafil significantly reduced dermal fibroblast gene expression and cellular release of IL-6, known to play a central role in the pathogenesis of tissue damage in SSc and IL-8, directly induced by ROS. This reduction was associated with suppression of STAT3-, ERK-, NF-κB-, and PKB/AKT-dependent pathways. Our findings support the notion that the employment of PDE5i in the management of RP may be explored for its efficacy in modulating the oxidative stress-induced proinflammatory activation of dermal fibroblasts in vivo and may ultimately aid in the prevention of tissue damage caused by SSc

    Genetic parameters of milk fatty acid profile in sheep: comparison between gas chromatographic measurements and Fourier-transform IR spectroscopy predictions.

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    Fatty acid (FA) composition is a key component of sheep milk nutritional quality. However, breeding for FA composition in dairy sheep is hampered by the logistic and phenotyping costs. This study was aimed at estimating genetic parameters for sheep milk FA and to test the feasibility of their routine measurement by using Fourier-transform IR (FTIR) spectroscopy. Milk FA composition of 989 Sarda ewes farmed in 48 flocks was measured by gas chromatography (FA GC ). Moreover, FTIR spectrum was collected for each sample, and it was used to predict FA composition (FA FTIR ) by partial least squares regression: 700 ewes were used for estimating model parameters, whereas the remaining 289 animals were used to validate the model. One hundred replicates were performed by randomly assigning animals to estimation and validation data set, respectively. Variance components for both measured and predicted traits were estimated with an animal model that included the fixed effects of parity, days in milking interval, lambing month, province, altitude of flock location, the random effects of flock-test-date and animal genetic additive. Genetic correlations among FA GC , and between corresponding FA GC and FA FTIR were estimated by bivariate analysis. Coefficients of determination between FA GC and FA FTIR ranged from moderate (about 0.50 for odd- and branched-chain FA) to high (about 0.90 for de novo FA) values. Low-to-moderate heritabilities were observed for individual FA (ranging from 0.01 to 0.47). The largest value was observed for GC measured C16:0. Low–to-moderate heritabilities were estimated for FA groups. In most of cases, heritabilites were slightly larger for FA GC than FA FTIR . Estimates of genetic correlations among FA GC showed a large variability in magnitude and sign. The genetic correlation between FA FTIR and FA GC was higher than 60% for all investigated traits. Results of the present study confirm the existence of genetic variability of the FA composition in sheep and suggest the feasibility of using FA FTIR as proxies for these traits in large scale breeding programs

    Use of partial least squares regression to impute SNP genotypes in Italian Cattle breeds

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    Background The objective of the present study was to test the ability of the partial least squares regression technique to impute genotypes from low density single nucleotide polymorphisms (SNP) panels i.e. 3K or 7K to a high density panel with 50K SNP. No pedigree information was used. Methods Data consisted of 2093 Holstein, 749 Brown Swiss and 479 Simmental bulls genotyped with the Illumina 50K Beadchip. First, a single-breed approach was applied by using only data from Holstein animals. Then, to enlarge the training population, data from the three breeds were combined and a multi-breed analysis was performed. Accuracies of genotypes imputed using the partial least squares regression method were compared with those obtained by using the Beagle software. The impact of genotype imputation on breeding value prediction was evaluated for milk yield, fat content and protein content. Results In the single-breed approach, the accuracy of imputation using partial least squares regression was around 90 and 94% for the 3K and 7K platforms, respectively; corresponding accuracies obtained with Beagle were around 85% and 90%. Moreover, computing time required by the partial least squares regression method was on average around 10 times lower than computing time required by Beagle. Using the partial least squares regression method in the multi-breed resulted in lower imputation accuracies than using single-breed data. The impact of the SNP-genotype imputation on the accuracy of direct genomic breeding values was small. The correlation between estimates of genetic merit obtained by using imputed versus actual genotypes was around 0.96 for the 7K chip. Conclusions Results of the present work suggested that the partial least squares regression imputation method could be useful to impute SNP genotypes when pedigree information is not available

    Estrogen-receptor-positive breast cancer in postmenopausal women: The role of body composition and physical exercise

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    Breast cancer (BC) is the most commonly diagnosed cancer among women worldwide and the most common cause of cancer-related death. To date, it is still a challenge to estimate the magnitude of the clinical impact of physical activity (PA) on those parameters producing significative changes in future BC risk and disease progression. However, studies conducted in recent years highlight the role of PA not only as a protective factor for the development of ER+ breast cancer but, more generally, as a useful tool in the management of BC treatment as an adjuvant to traditional therapies. In this review, we focused our attention on data obtained from human studies analyzing, at each level of disease prevention (i.e., primary, secondary, tertiary and quaternary), the positive impact of PA/exercise in ER+ BC, a subtype representing approximately 70% of all BC diagnoses. Moreover, given the importance of estrogen receptors and body composition (i.e., adipose tissue) in this subtype of BC, an overview of their role will also be made throughout this review

    Environmental variables and machine learning models to predict cetacean abundance in the Central-eastern Mediterranean Sea

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    : Although the Mediterranean Sea is a crucial hotspot in marine biodiversity, it has been threatened by numerous anthropogenic pressures. As flagship species, Cetaceans are exposed to those anthropogenic impacts and global changes. Assessing their conservation status becomes strategic to set effective management plans. The aim of this paper is to understand the habitat requirements of cetaceans, exploiting the advantages of a machine-learning framework. To this end, 28 physical and biogeochemical variables were identified as environmental predictors related to the abundance of three odontocete species in the Northern Ionian Sea (Central-eastern Mediterranean Sea). In fact, habitat models were built using sighting data collected for striped dolphins Stenella coeruleoalba, common bottlenose dolphins Tursiops truncatus, and Risso's dolphins Grampus griseus between July 2009 and October 2021. Random Forest was a suitable machine learning algorithm for the cetacean abundance estimation. Nitrate, phytoplankton carbon biomass, temperature, and salinity were the most common influential predictors, followed by latitude, 3D-chlorophyll and density. The habitat models proposed here were validated using sighting data acquired during 2022 in the study area, confirming the good performance of the strategy. This study provides valuable information to support management decisions and conservation measures in the EU marine spatial planning context

    Effects of Dietary Zn/Se and α-Tocopherol Supplementation on Metabolic Milieu, Haemogram and Semen Traits of Breeding Stallions

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    Trace element status and metabolic milieu are sometimes overlooked in common veterinary clinical practice across animal species. The evaluation of requirements of trace elements, in fact, may be useful to prevent the perturbation of tissue-specific metabolic impair. In particular, essential trace elements in the diet play key roles within sub-cellular metabolic patterns with macro effects at the systemic level, like blood cell stability and semen quality. This effect was studied in breeding stallions, in which semen quality and haemogram are important for reproduction. A case-control feeding trial involved 40 stallions (age: 8–21 years; body weight, BW: 510–531 kg) of one stud centre, allotted to two experimental groups (n = 20 control, CON vs. n = 20 supplemented, SUPPL100), following a matched-pairs approach based on age. Supplemented stallions (SUPPL100) received a mixed mineral and vitamin supplement of Zn/Se and α-tocopherol (α-TOH) (100 g/day stallion) to compound feed, fed as control diet to horses of the control group (CON). Horses resulted deficient in circulating α-TOH and Zn at the start, though clinically healthy. After supplementation, different plasmatic levels of α-TOH, Zn and Se were found between groups. Circulating basophils (BASO) and mean cell haemoglobin concentration (MCHC) were affected by the dietary treatment (p < 0.05). Plasmatic Se affected monocyte count, haematocrit, mean cell volume and mean cell haemoglobin concentration. Semen traits were not affected by the dietary treatment per se, except for mobile/progressive sperm cells (%) of stallions aged > 13 years marginal circulating levels of α-TOH (p = 0.04). Ameliorating the micromineral status showed to improve the haemogram of stallions in view of circulating levels of Cu. Semen quality appeared to be strongly dependent on animal effects

    Many-electron tunneling in atoms

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    A theoretical derivation is given for the formula describing N-electron ionization of atom by a dc field and laser radiation in tunneling regime. Numerical examples are presented for noble gases atoms.Comment: 11 pages, 1 EPS figure, submitted to JETP (Jan 99
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