Automatic modal identification of bridges based on free vibrations and advanced signal decomposition techniques

Free vibration tests are attractive because they can be performed by means of a network consisting of few sensors temporarily installed on the structure in such a way to limit duration and cost of the experimental campaign. Additionally, free vibration tests are usually performed by introducing an initial perturbation that can induce a structural response significantly higher than the ambient excitation. This, in turn, allows to reduce the noise-to-signal ratio in the final measurements and/or to consider less stringent requirements about the technical specifications of the sensors. Since free vibration tests can provide accurate estimates of the modal parameters while being rather cheap and easy to implement, they have been performed in many applications, such as the experimental dynamic characterization of base-isolated buildings, masonry towers, ancient tie-rods, and bridges. An efficient and automatic computational framework is thus presented for the modal identification of bridges based on their free vibrations. The novel procedure proposed in the current work combines advanced signal decomposition techniques and a robust approach for damping identification. Two advanced signal decomposition techniques are considered, namely the Variational Mode Decomposition and the Empirical Fourier Decomposition. Experimental applications are then illustrated for roadway and railway bridges

Culturomics: bacterial species isolated in 3 healthy donors for faecal microbiota transplantation in Clostridium difficile infection

Background. Clostridium difficile infections are the main cause of nosocomial acquired diarrhea, because of prolonged antibiotic regimens. In the last years, mortality has increased due to recurrent infections caused by metronidazole and vancomicin resistant hypervirulent C. difficile strain 027. Faecal Microbiota Transplantation (FMT) is an infusion of faecal material obtained from healthy donors. This procedure reduces mortality in recurrent C. difficile infections (CDI). In this study we identified bacterial species obtained from donors' stool samples using culturomics. Materials and methods. Three donors were selected for FMT in three recipients affected by CDI. Faces obtained for FMT underwent culturomics, applying 17 different culture methods. Results and conclusions. Several different bacteria were isolated from donors. In two donors 4 potentially pathogenic bacteria were isolated; this suggests the use of culturomics for donors' screening or for selection of bacteria to infuse

Hypo and retrotympanum: the importance of anatomical variants

The hypo- and retrotympanum host a variety of crucial anatomical structures1, characterized by high variability, which are poorly been described. The aim of our study is to describe and classify the anatomical variants of the hypo- and retrotympanum by the means of transcanal endoscopy2. We hypothesize that the retro- and hypotympanum are subject to more anatomical variability than actually thought. Moreover, the configuration as bridge variants and variably shaped sinus interconnects the different subregions. A total of 125 middle ears (83 cadaveric dissections) were explored by the means of 3mm straight and angled scopes. The variants were documented photographically and tabularized. The bony crests ponticulus, subiculum and finiculus1 were most frequently represented as ridges. The ponticulus showed the highest variability with 38% ridge, 35% bridge and 27% incomplete presentation. The subiculum was bridge - shaped only in 8% of the cases, while the finiculus in 17%. The sinus tympani had a normal shape in 66% of the cases. A subcochlear canaliculus was observed in 50%. The retro- and hypotympanum were classified respectively to the present bony crests and sinus in chambers type I to IV. In our opinion, the retro- and hypotympanum have to be considered as a tightly coherent region of the middle ear. For this purpose, we propose a straightforward classification, according to the presence of the different bony crests and sinus forming the different chambers of the retro- and hypotympanum. The introduced classification may also serve as intraoperative assessment, to be aware of the different anatomical subregions. The hidden areas of the retro- and hypotampanum are difficult to access and therefore represent a region of risk for residual cholesteatomatous disease after surgical treatment. The extension below a bridge bony crest or into a deep sinus demands thorough exploration; therefore, exact anatomical knowledge and an effective technique to visualize the whole middle ear are required

Museus sem lugar: ensaios, manifestos e diálogos em rede

Contém artigos de: Helena Barranha - Introdução: manifestos por um museu sem lugar (pp.3-8); Natalie Bookchin e Alexei Shulgin - Introdução à net.art (1994-1999) [1999] (pp.11-18); Andreas Broegger - Net Art, web art, online art, net.art? [2000] (pp.19-24); Josephine Berry - Humano, demasiado Pós-Humano? A Net Art e os seus críticos [2000] (pp.25-33); Jon Ippolito - Dez mitos sobre a Internet Art [2002] (pp.34-44); Manuel Castells - Os museus na era da informação: conectores culturais de tempo e espaço [2001] (pp.47-62); Yehuda Kalay e John Marx - Arquitectura e Internet: projectar lugares no ciberespaço [2005] (pp.63-87); Erkki Huhtamo - Nas (ou para além das) pontas dos dedos: arte contemporânea, práticas expositivas e tactilidade [2008] (pp.88-102); Domenico Quaranta - Perdido na tradução. Ou trazer a Net Art para outro lugar – desculpem, contexto [2008] (pp.103-120); Marisa Olson - Pós-Internet: A Arte depois da Internet [2011] (pp.123-136); Fred Forest - A arte cosa mentale. Do visível ao invisível e da realidade a uma realidade... diferente. [2012] (pp.137-141); Hito Steyerl - Demasiado mundo: a Internet morreu? [2012] (pp.142-158); Excertos das entrevistas realizadas, no âmbito do projecto unplace, a artistas, curadores e investigadores (pp.159-196)

Knowledge about tuberculosis among undergraduate health care students in 15 Italian universities: a cross-sectional study

Background: The Italian Study Group on Hospital Hygiene of the Italian Society of Hygiene, Preventive Medicine and Public Health conducted a multicentre survey aiming to evaluate undergraduate health care students' knowledge of tuberculosis and tuberculosis control measures in Italy. Methods. In October 2012-June 2013, a sample of medical and nursing students from 15 Italian universities were enrolled on a voluntary basis and asked to complete an anonymous questionnaire investigating both general knowledge of tuberculosis (aetiology, clinical presentation, outcome, screening methods) and personal experiences and practices related to tuberculosis prevention. Data were analysed through multivariable regression using Stata software. Results: The sample consisted of 2,220 students in nursing (72.6%) and medicine (27.4%) courses. Our findings clearly showed that medical students had a better knowledge of tuberculosis than did nursing students.Although the vast majority of the sample (up to 95%) answered questions about tuberculosis aetiology correctly, only 60% of the students gave the correct responses regarding clinical aspects and vaccine details. Overall, 66.9% of the students had been screened for tuberculosis, but less than 20% of those with a negative result on the tuberculin skin test were vaccinated. Multivariable regression analysis showed that age and type of study programme (nursing vs. medical course) were determinants of answering the questions correctly. Conclusions: Although our data showed sufficient knowledge on tuberculosis, this survey underlines the considerable need for improvement in knowledge about the disease, especially among nursing students. In light of the scientific recommendations concerning tuberculosis knowledge among students, progress of current health care curricula aimed to develop students' skills in this field is needed