4,749 research outputs found

    Operators in Rigged Hilbert spaces: some spectral properties

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    A notion of resolvent set for an operator acting in a rigged Hilbert space \D \subset \H\subset \D^\times is proposed. This set depends on a family of intermediate locally convex spaces living between \D and \D^\times, called interspaces. Some properties of the resolvent set and of the corresponding multivalued resolvent function are derived and some examples are discussed.Comment: 29 page

    Ovine Catarrhal fever (bluetongue): Analysis of Culicoides species in seropositive farms

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    Bluetongue (BT) is an orbiviral disease of wild and domestic ruminants, mainly sheep. In Sicily, the first Bluetongue outbreak occurred in October 2000; there have been 76 recorded outbreaks so far. The National Surveillance Plan, based on European Union Commission Decision 138/2001/CE, establishes serological and entomological surveys. This plan consists of controls of seronegative cattle, called 'sentry' as indicators for the presence and circulation of virus in defined areas. To check the seroconversions, the regional territory has been subdivided in 400 km2 areas including 58 seronegative cattle, periodically checked by serological tests. All positive sera have been tested to detect the specific serotype by the National Reference Centre for Exotic Diseases (CESME) at the Istituto Zooprofilattico Sperimentale Abruzzo e Molise in Teramo (IZS Teramo). Moreover, entomological surveillance has been implemented in seropositive herds, to investigate the presence of insect vectors belonging to Culicoides genus. The goal of the present communication is to report on the different species of Culicoides found in the farms with Bluetongue virus and to investigate on the probable role of new competent vectors. This paper concerns data analysis of 581 light-trap catches collected in 321 farms from 2003 to 2008. We observed that 82% of checked farms were positive for Culicoides spp., and only 10% of the farms were positive for Culicoides imicola. © 2010 Blackwell Verlag GmbH

    Assessment of ageing effect on the mechanical behaviour of steel/aluminium self-piercing riveted joint

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    Self-piercing riveting (SPR) is a new performing technology able to joint several kinds of metal and non-metal supports together. The combined effect of joint configuration and environmental conditions could have detrimental effect on the ageing effect on mechanical behaviour of dissimilar metal SPR joints. The joining of dissimilar materials, such as steel and aluminium, realized by self-piercing riveting (SPR) technique was studied to evaluate the ageing effects on its mechanical behaviour in critical environmental conditions. The investigation was carried out on symmetrical or unsymmetrical joints at varying total thicknesses (i.e. 2.0, 2.5 and 3.0 mm). The joint resistance was determined by single-lap shear tests. A design of experiment (DoE) has been performed by using Minitab® followed by the statistical analysis (ANOVA) of the experimental data. Long-term ageing tests in salt spray environment were performed to evaluate the durability of the mechanical joint. The experimental results evidenced that the corrosion degradation phenomena influenced significantly both the performance and failure mechanisms of the joints; also, the joint configuration is a significant factor for the corrosion effect. In the salt spray, the aluminium sheet undergoes a noticeable degradation due to galvanic Al/Fe corrosion. The set characterized by thinner aluminium sheet evidenced a gradual reduction of the mechanical strength with increasing ageing time due to the prevalence of thinning induced by aluminium corrosion. Instead, for S10-A15 samples (characterized by a thicker thickness of aluminium sheet) during the first 7 weeks, stable mechanical performances were observed. The experimental results evidenced that the corrosion degradation phenomena influence significantly both performances and failure mechanisms of SPR joints. Furthermore, the durability of the SPR joint is strongly affected by the joint configuration, and the best results were observed in the unsymmetrical joint with thicker aluminium sheet

    Functional assessment of cancer therapy questionnaire for breast cancer (FACT-B+4): Italian version validation

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    BACKGROUND: Improvements in breast cancer diagnosis and treatment led to an increased incidence of survivors' rate. The healthcare system has to face new problems related not only to the treatment of the disease, but also to the management of the quality of life after the diagnosis. The aim of this study was to validate the Italian version of the Functional Assessment of Cancer Therapy - Breast (FACT-B+4) questionnaire and to evaluate its reliability. METHODS: The questionnaire was administered twice, with an interval of three days between each administration, to a cohort of women of the Breast Surgical Unit, PoliclincoUmberto I. Cronbach's alpha was used as a measure of the internal consistency of the Italian version. RESULTS: The Italian version of the tool was administered to 55 subjects. The Cronbach's alpha for most scores registered values >0.7, both at baseline and at the follow-up analysis, therefore the subscale showed good internal consistency. CONCLUSIONS: The Italian version of FACT-B+4 demonstrated acceptable reliability properties in the Breast Unit patients. The use of this questionnaire seemed to be effective and in line with the results derived from the English and Spanishversions. Internal consistency and validity had similar performance results

    Surgical complications after pancreatic transplantation: A computed tomography imaging pictorial review

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    pancreatic transplantation should start with the evaluation of the arterial Y-graft, the venous anastomosis and the duodenojejunostomy. With regard to complications, CT allows for the identification of vascular complications, such as thrombosis or stenosis of blood vessels supplying the graft, the detection of pancreatic fluid collections, including pseudocysts, abscesses, or leaks, the assessment of bowel complications (anastomotic leaks, ileus or obstruction), and the identification of bleeding. The aim of this pictorial review is to illustrate CT findings of surgical-related complications after pancreatic transplantation. The knowledge of surgical techniques is of key importance to understand postoperative anatomic changes and imaging evaluation. Therefore, we first provide a short summary of the main techniques of pancreatic transplantation. Then, we provide a practical imaging approach to pancreatic transplantation and its complications providing tips and tricks for the prompt imaging diagnosis on CT.Pancreatic transplantation is considered by the American Diabetes Association and the European Association for the Study of Diabetes an acceptable surgical procedure in patients with type 1 diabetes also undergoing kidney transplantation in pre-final or end-stage renal disease if no contraindications are present. Pancreatic transplantation, however, is a complex surgical procedure and may lead to a range of postoperative complications that can significantly impact graft function and patient outcomes. Postoperative computed tomography (CT) is often adopted to evaluate perfusion of the transplanted pancreas, identify complications and as a guide for interventional radiology procedures. CT assessment afte

    Exploiting Slow Dynamics Effects for Damage Detection in Concrete

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    Nonlinear ultrasonic techniques have been developed over the last decades to detect the presence of damage in materials of interest in the field of civil engineering, such as concrete or mortar. The dependence on the strain amplitude of measurable quantities, such as wave velocity, damping factor, resonance frequency, etc. is normally considered a qualitative indicator of the presence of defects at the microstructural level. The experimental approaches proposed have the advantage of being sensitive to small variations in the sample microstructure and are therefore more adapted to detect the presence of small cracks or damaged areas with respect to traditional linear ultrasonic techniques. However, nonlinear methods are difficult to implement, since they usually require a calibrated experimental set-up which also behaves linearly at high amplitudes of excitation. The slow dynamics features, typical of the hysteresis generated by damage, have been given much less attention as a tool for damage detection even though their quantification is often less demanding in terms of an experimental set-up. Here, we provide the first evidence of how recovery, which is part of the slow dynamics process, is sensitive to the presence of damage in concrete samples and thus could be considered as an easy-to-measure nonlinear indicator for Structural Health Monitoring purposes

    Effects of Autologous Microfragmented Adipose Tissue on Healing of Tibial Plateau Levelling Osteotomies in Dogs: A Prospective Clinical Trial

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    The aim of this study was to evaluate the effects of autologous microfragmented adipose tissue (MFAT) applied after mechanical fragmentation and assess these effects radiographically in bone healing in dogs subjected to tibial plateau levelling osteotomy (TPLO). Twenty dogs with unilateral cranial cruciate ligament disease were enrolled and randomly assigned to the treatment group (MFAT) or the control group (NT). The MFAT group underwent TPLO and autologous MFAT intra-articular administration, while the NT group underwent TPLO alone. Adipose tissue was collected from the thigh region, and MFAT was obtained by mechanical fragmentation at the end of the surgery. The patients were subjected to X-ray examination preoperatively, immediately postoperatively (T0), and at 4 (T1) and 8 (T2) weeks postoperatively. Two radiographic scores that had previously been described for the evaluation of bone healing after TPLO were used. A 12-point scoring system (from 0 = no healing to 12 = complete remodelling) was used at T0, T1, and T2, while a 5-point scoring system (from 0 = no healing to 4 = 76–100% of healing) was used at T1 and T2. The median healing scores were significantly higher at T1 and T2 for the MFAT group compared with the NT group for the 12-point (p < 0.05) and 5-point (p < 0.05) scoring systems. The intra-articular injection of autologous microfragmented adipose tissue can accelerate bone healing after TPLO without complication

    Assessment of Yield and Quality of Eggplant (Solanum melongena L.) Fruits Improved by Biodegradable Mulching Film in Two Different Regions of Southern Italy

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    Low-density polyethylene (LDPE) mulching films have an important function in crop cultivation; at the end of their life, however, their removal and disposal become both an economic and environmental problem. One possible alternative to low-density polyethylene (LDPE) mulch is provided by certified soil-biodegradable mulch films, such as those produced by Novamont and commercially available under the trade name MaterBi (R). MaterBi is a biodegradable thermoplastic material made with starch and a biodegradable copolyester based on proprietary technology. In this study, we compared two biodegradable MaterBi (R)-based films (commercial and experimental films) with bare soil and a low-density polyethylene to evaluate their effect on yield and on a number of qualitative characteristics (organoleptic and nutraceutical composition) of eggplant fruits (cv Mirabelle F1) grown in two different regions in Southern Italy (Sicily and Campania). In our study, the use of biodegradable MaterBi (R) films improved not only yield and production parameters, such as the number and average weight of fruits, but also lipophilic and hydrophilic antioxidant activity and phenolic and ascorbic acid content. For many parameters, responses differed according to the cultivation environment and, in particular, the site's pedoclimatic conditions. Our results suggest that biodegradable MaterBi (R)-based mulching films are a potentially valid alternative to traditional LDPEs, providing the production and quality benefits reported above and promoting environmental sustainability, thanks to their positive biodegradable properties
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