689 research outputs found

    Gamma-Ray Astronomy around 100 TeV with a large Muon Detector operated at Very High Altitude

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    Measurements at 100 TeV and above are an important goal for the next generation of high energy gamma-ray astronomy experiments to solve the still open problem of the origin of galactic cosmic rays. The most natural experimental solution to detect very low radiation fluxes is provided by the Extensive Air Shower (EAS) arrays. They benefit from a close to 90% duty cycle and a very large field of view (about 2 sr), but the sensitivity is limited by their angular resolution and their poor cosmic ray background discrimination. Above 10 TeV the standard technique for rejecting the hadronic background consists in looking for "muon-poor" showers. In this paper we discuss the capability of a large muon detector (A=2500 m2) operated with an EAS array at very high altitude (>4000 m a.s.l.) to detect gamma-ray fluxes around 100 TeV. Simulation-based estimates of energy ranges and sensitivities are presented.Comment: 4 pages, proceedings of the 30th ICRC, Merida, Mexico, 200

    Evaluation of cephalometric, hormonal and enzymatic parameters in young obese subjects

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    Aim The aim of the present investigation was to analyse cephalometric skeletal structures and hormonal and enzymatic parameters in young obese subjects in comparison with those of normal weight subjects. Materials and methods The whole sample consisted of 50 Caucasian patients (28 males and 22 females) whose lateral radiographs, laboratory hormonal and enzymatic analyses were already available. The test group included 25 obese patients (11 females and 14 males, average age: 9.8 ± 2.11 years old), while the control group included 25 normal weight subjects matched for age and sex (11 females and 14 males, 9.9 ± 2.5 years old). Data were statistically analysed: Student’s t-test for independent samples was adopted and the level of significance was set at: p< 0.05. Results As regards cephalometric records, the anterior cranial base length was significantly greater in the test group (S-N: 69.9 ± 4 mm) compared to the controls (S-N: 68.1 ± 2.7 mm). Moreover, the maxillary lenght was higher in the test group (Pm-A: 48.5 ± 2.5 mm ) in comparison to the control group (Pm-A: 46.1 ± 1.9 mm). As regards skeletal class and vertical dimension, no significant differences were found between the two groups, with the exception of the intermaxillary plane angle, which was significantly lower in the obese subjects in comparison to the controls. Laboratory analysis showed significant (p <0.05) higher levels of leptin and insulin in the test group in comparison with control subjects. Furthermore, LH, FSH, IGF-1 values were significantly (p <0.05) lower in the test group in comparison with the control group. Conclusion Obese subjects exhibited an increase of some craniofacial parameters and alteration of some laboratory parameters that may be involved in the process of skeletal maturation, in comparison to normal weight subjects. These findings may be of interest in orthodontics, as young obese subjects may need a different orthodontic treatment plan in comparison to Evaluation normal weight subjects of the same age

    Gut microbiota plasticity in insular lizards under reversed island syndrome

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    Animals living on small islands are more drastically exposed to environmental changes, such as food or water starvation, and rapid temperature shifts. Facing such conditions, and probably thank to adaptive plasticity mechanisms, some animals display a Reversed Island Syndrome (RIS), a suite of traits, including skin pigmentation, voracity, sexual dimorphism, showed differently from mainland relatives. Here, we analyse a so far poorly explored aspect of RIS: the effect of this on the microbiota composition of host Italian wall lizard (Podarcis siculus), strongly influenced by the animal's lifestyle, and conditioning the same. We compare mainland and island populations, assessing the difference between their microbial communities and their response under unexpected food, experimentally provided. Our observations showed a significant difference in microbiota communities between island and mainland groups, depended mainly from changes in relative abundance of the shared genera (difference due to decrease/increase). Exposure to experimental diet regimes resulted into significative reshaping of bacterial composition of microbiota and a greater variation in body mass only in the island population. Our results could be an evidence that gut microbial community contributes to adaptive plasticity mechanisms of island lizards under RIS to efficiently respond to unexpected changes

    Nasal immunization with the c-terminal domain of bcla3 induced specific igg production and attenuated disease symptoms in mice infected with clostridioides difficile spores

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    Clostridioides difficile is a Gram-positive, spore-forming bacterium that causes a severe intestinal infection. Spores of this pathogen enter in the human body through the oral route, interact with intestinal epithelial cells and persist in the gut. Once germinated, the vegetative cells colonize the intestine and produce toxins that enhance an immune response that perpetuate the disease. Therefore, spores are major players of the infection and ideal targets for new therapies. In this context, spore surface proteins of C. difficile, are potential antigens for the development of vaccines targeting C. difficile spores. Here, we report that the C-terminal domain of the spore surface protein BclA3, BclA3CTD, was identified as an antigenic epitope, over-produced in Escherichia coli and tested as an immunogen in mice. To increase antigen stability and efficiency, BclA3CTD was also exposed on the surface of B. subtilis spores, a mucosal vaccine delivery system. In the experimental conditions used in this study, free BclA3CTD induced antibody production in mice and attenuated some C. difficile infection symptoms after a challenge with the pathogen, while the spore-displayed antigen resulted less effective. Although dose regimen and immunization routes need to be optimized, our results suggest BclA3CTD as a potentially effective antigen to develop a new vaccination strategy targeting C. difficile spores

    Nasal immunization with the c-terminal domain of bcla3 induced specific igg production and attenuated disease symptoms in mice infected with clostridioides difficile spores

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    Indexación: Scopus.Clostridioides difficile is a Gram-positive, spore-forming bacterium that causes a severe intestinal infection. Spores of this pathogen enter in the human body through the oral route, interact with intestinal epithelial cells and persist in the gut. Once germinated, the vegetative cells colonize the intestine and produce toxins that enhance an immune response that perpetuate the disease. Therefore, spores are major players of the infection and ideal targets for new therapies. In this context, spore surface proteins of C. difficile, are potential antigens for the development of vaccines targeting C. difficile spores. Here, we report that the C-terminal domain of the spore surface protein BclA3, BclA3CTD, was identified as an antigenic epitope, over-produced in Escherichia coli and tested as an immunogen in mice. To increase antigen stability and efficiency, BclA3CTD was also exposed on the surface of B. subtilis spores, a mucosal vaccine delivery system. In the experimental conditions used in this study, free BclA3CTD induced antibody production in mice and attenuated some C. difficile infection symptoms after a challenge with the pathogen, while the spore-displayed antigen resulted less effective. Although dose regimen and immunization routes need to be optimized, our results suggest BclA3CTD as a potentially effective antigen to develop a new vaccination strategy targeting C. difficile spores. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.https://www.mdpi.com/1422-0067/21/18/669

    WNT5A-JNK regulation of vascular insulin resistance in human obesity

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    Obesity is associated with the development of vascular insulin resistance; however, pathophysiological mechanisms are poorly understood. We sought to investigate the role of WNT5A-JNK in the regulation of insulin-mediated vasodilator responses in human adipose tissue arterioles prone to endothelial dysfunction. In 43 severely obese (BMI 44±11 kg/m2) and five metabolically normal non-obese (BMI 26±2 kg/m2) subjects, we isolated arterioles from subcutaneous and visceral fat during planned surgeries. Using videomicroscopy, we examined insulin-mediated, endothelium-dependent vasodilator responses and characterized adipose tissue gene and protein expression using real-time polymerase chain reaction and Western blot analyses. Immunofluorescence was used to quantify endothelial nitric oxide synthase (eNOS) phosphorylation. Insulin-mediated vasodilation was markedly impaired in visceral compared to subcutaneous vessels from obese subjects (pWNT5A and its non-canonical receptors, which correlated negatively with insulin signaling. Pharmacological JNK antagonism with SP600125 markedly improved insulin-mediated vasodilation by sixfold (p
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