3,470 research outputs found

    Astrocomp: a web service for the use of high performance computers in Astrophysics

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    Astrocomp is a joint project, developed by the INAF-Astrophysical Observatory of Catania, University of Roma La Sapienza and Enea. The project has the goal of providing the scientific community of a web-based user-friendly interface which allows running parallel codes on a set of high-performance computing (HPC) resources, without any need for specific knowledge about parallel programming and Operating Systems commands. Astrocomp provides, also, computing time on a set of parallel computing systems, available to the authorized user. At present, the portal makes a few codes available, among which: FLY, a cosmological code for studying three-dimensional collisionless self-gravitating systems with periodic boundary conditions; ATD, a parallel tree-code for the simulation of the dynamics of boundary-free collisional and collisionless self-gravitating systems and MARA, a code for stellar light curves analysis. Other codes are going to be added to the portal.Comment: LaTeX with elsart.cls and harvard.sty (included). 7 pages. To be submitted to a specific journa

    Multivariate analysis of brain metabolism reveals chemotherapy effects on prefrontal cerebellar system when related to dorsal attention network

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    BACKGROUND: Functional brain changes induced by chemotherapy are still not well characterized. We used a novel approach with a multivariate technique to analyze brain resting state [(18) F]FDG-PET in patients with lymphoma, to explore differences on cerebral metabolic glucose rate between chemotherapy-treated and non-treated patients. METHODS: PET/CT scan was performed on 28 patients, with 14 treated with systemic chemotherapy. We used a support vector machine (SVM) classification, extracting the mean metabolism from the metabolic patterns, or networks, that discriminate the two groups. We calculated the correct classifications of the two groups using the mean metabolic values extracted by the networks. RESULTS: The SVM classification analysis gave clear-cut patterns that discriminate the two groups. The first, hypometabolic network in chemotherapy patients, included mostly prefrontal cortex and cerebellar areas (central executive network, CEN, and salience network, SN); the second, which is equal between groups, included mostly parietal areas and the frontal eye field (dorsal attention network, DAN). The correct classification membership to chemotherapy or not chemotherapy-treated patients, using only one network, was of 50% to 68%; however, when all the networks were used together, it reached 80%. CONCLUSIONS: The evidenced networks were related to attention and executive functions, with CEN and SN more specialized in shifting, inhibition and monitoring, DAN in orienting attention. Only using DAN as a reference point, indicating the global frontal functioning before chemotherapy, we could better classify the subjects. The emerging concept consists in the importance of the investigation of brain intrinsic networks and their relations in chemotherapy cognitive induced changes

    Kidney, kidney-pancreas and liver-kidney transplantation in HIV infected individuals: the Italian experience

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    Until a few years ago, HIV infection was considered an exclusion criteria for organ transplantation. However, more recently, because of the significant increase in life expectancy of HIV-infected persons with highly active antiretroviral therapy (HAART), kidney, kidney-pancreas, heart, lung and liver transplantation have been introduced in this patients population in several centers around the world. To evaluate the possible extension of the indications of kidney transplantation to HIV-infected individuals, the Italian National Centre for Transplantation has designed a protocol to be applied on a national basis. Inclusion criteria required a CD4 count ≄200/mm3 and undetectable HIV viral load for at least 3 months for patients on HAART.The program was voluntarily adopted by 4 transplant centres. From January 2006 through November 2007 a total of 13 HIV infected patients (9 male and 4 female, mean age 46.4 years, range 35-56) underwent cadaveric kidney transplantation (including two kidney-pancreas and two liver-kidney) after a median waiting time of 142 days (range 58-650). Median CD4 cells count at the time of transplantation was 449 (range 210-782) and the HIV-RNA was undetectable in all recipients. HAART was started in all recipients after transplantation and HIV-RNA remain undetectable in all patients. Five patients (38.4%) experienced an episode of biopsy proven acute rejection (steroid resistant in one). Drug-drug interactions between antiretrovirals and immunosuppressive agents required frequent dosage modifications. Graft and patient survival was 100% at a median follow-up of 161 days after transplantation (range 8-669). Despite the limited number of patients and the shortness of the follow-up, our study confirms excellent short term results of kidney transplantation in HIV-infected individuals

    Equalizing the Pixel Response of the Imaging Photoelectric Polarimeter On-Board the IXPE Mission

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    The Gas Pixel Detector is a gas detector, sensitive to the polarization of X-rays, currently flying on-board IXPE - the first observatory dedicated to X-ray polarimetry. It detects X-rays and their polarization by imaging the ionization tracks generated by photoelectrons absorbed in the sensitive volume, and then reconstructing the initial direction of the photoelectrons. The primary ionization charge is multiplied and ultimately collected on a finely-pixellated ASIC specifically developed for X-ray polarimetry. The signal of individual pixels is processed independently and gain variations can be substantial, of the order of 20%. Such variations need to be equalized to correctly reconstruct the track shape, and therefore its polarization direction. The method to do such equalization is presented here and is based on the comparison between the mean charge of a pixel with respect to the other pixels for equivalent events. The method is shown to finely equalize the response of the detectors on board IXPE, allowing a better track reconstruction and energy resolution, and can in principle be applied to any imaging detector based on tracks.Comment: Accepted for publication in The Astronomical Journal. 10 pages, 19 figure

    Agronomic performance of 21 new disease resistant winegrape varieties grown in northeast Italy

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    The goal of the field trial was to evaluate the agronomic performance of 21 (10 red and 11 white) winegrape varieties obtained from recent breeding programmes for disease resistance developed in Hungary, Germany, and Italy. The tested red varieties were as follows: ‘Cabernet Carbon’, ‘Cabernet Eidos’, ‘Cabernet Volos’, ‘Julius’, ‘Merlot Khorus’, ‘Merlot Kanthus’, ‘Monarch’, ‘Prior’, UD. 31.103, ‘Vinera’. The tested white varieties were as follows: ‘Aromera’, ‘Bronner’, ‘Fleurtai’, ‘Johanniter’, ‘Muscaris’, ‘Souvignier Gris’, ‘Sauvignon Kretos’, ‘Sauvignon Nepis’, ‘Sauvignon Rytos’, ‘Solaris’, ‘Soreli’. ‘Merlot’ (red) and ‘Glera’ (white) were included as control. The experimental vineyard was established in Castelfranco Veneto on the plain, in 2014. Spray treatments were applied against downy and powdery mildew, by using only copper and sulphur. Grape production, grape quality, and phenology were recorded over a six-year-period, while disease resistance (downy mildew, powdery mildew, black rot and anthracnose) was detected only during a few years. The most significant findings were: a) all varieties showed a good level of downy mildew resistance, especially ‘Cabernet Carbon’, ‘Monarch’, ‘Prior’, UD 31.103, ‘Muscaris’, ‘Solaris’, ‘Souvignier Gris’, ‘Bronner’, ‘Fleurtai’, ‘Aromera’; b) no powdery mildew attacks were detected in any variety; c) ‘Monarch’, ‘Muscaris’, ‘Solaris’ and ‘Souvignier Gris’ also showed a high level of resistance towards black rot and anthracnose; d) red grape varieties had an earlier bud burst as compared to ‘Merlot’, and, concerning ripening, some varieties were earlier than ‘Merlot’, other ones were later; e) white varieties had a later bud burst but an earlier ripening time as compared to ‘Glera’; f) grape production and quality changed significantly depending on the varieties, being titratable acidity higher than 6.4 g L-1 tartaric acid and pH lower than 3.5; also the year affected in a significant way those parameters as well as the interaction between the genotype and the year. In conclusion, the tested varieties behaved positively in terms of environmental sustainability

    Reliability of forced internal rotation and active internal rotation to assess lateral instability of the biceps pulley

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    Purpose: the aim of this study was to investigate the relationship between positive painful forced internal rotation (FIR) and lateral pulley instability in the presence of a pre-diagnosed posterosuperior cuff tear. The same investigation was conducted for painful active internal rotation (AIR). Methods: a multicenter prospective study was conducted in a series of patients scheduled to undergo arthroscopic posterosuperior cuff repair. Pain was assessed using a visual analog scale (VAS) and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) was administered. The VAS score at rest, DASH score, and presence/absence of pain on FIR and AIR were recorded and their relationships with lesions of the lateral pulley, cuff tear patterns and shape of lesions were analyzed. Results: the study population consisted of 115 patients (mean age: 55.1 years) recruited from 12 centers. The dominant arm was affected in 72 cases (62.6%). The average anteroposterior extension of the lesion was 1.61 cm. The mean preoperative VAS and DASH scores were 6.1 and 41.8, respectively. FIR and AIR were positive in 94 (81.7%) and 85 (73.9%) cases, respectively. The lateral pulley was compromised in 50 cases (43.4%). Cuff tears were partial articular in 35 patients (30.4%), complete in 61 (53%), and partial bursal in 19 (16.5%). No statistical correlation between positive FIR or AIR and lateral pulley lesions was detected. Positive FIR and AIR were statistically associated with complete lesions. Negative FIR was associated with the presence of partial articular tears. Conclusions: painful FIR in the presence of a postero-superior cuff tear does not indicate lateral pulley instability. When a cuff tear is suspected, positive FIR and AIR are suggestive of full-thickness tear patterns while a negative FIR suggests a partial articular lesion. Level of evidence: level I, validating cohort study with good reference standards

    Designing the Future: An Intelligent System for Zero-Mile Food Production by Upcycling Wastewater

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    The project deals with the environmental problem of water consumption. The aim of this work is to experiment the recycling of dishwasher wastewater through its reuse in growing edible vegetables or ornamental plants; this can also accomplish the valorization of nutrients present in the wastewater. This new process allows to ensure washing functions coupled with vegetables production and to affect users’ environmental awareness and habits, following a user-centered system design approach to understand the users and involve them actively in the system development. The presented work is also aimed to experiment a multidisciplinary approach in order to face environmental problems

    An Algorithm to Calibrate and Correct the Response to Unpolarized Radiation of the X-Ray Polarimeter Onboard IXPE

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    The Gas Pixel Detector (GPD) is an X-ray polarimeter to fly onboard IXPE and other missions. To correctly measure the source polarization, the response of IXPE's GPDs to unpolarized radiation has to be calibrated and corrected. In this paper, we describe the way such response is measured with laboratory sources and the algorithm to apply such correction to the observations of celestial sources. The latter allows to correct the response to polarization of single photons, therefore allowing great flexibility in all the subsequent analysis. Our correction approach is tested against both monochromatic and nonmonochromatic laboratory sources and with simulations, finding that it correctly retrieves the polarization up to the statistical limits of the planned IXPE observations
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