8,743 research outputs found

    Structural health monitoring of different geometry structures with optical fiber sensors

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    In this paper, we describe the structural health monitoring of several structures, with different geometry, materials and behaviors, using optical fiber sensors. Those studies aimed to demonstrate the feasibility of such technologies in structural health monitoring, with all the advantages inherent to the optical fiber technology

    Thoracic, abdominal and musculoskeletal involvement in Erdheim-Chester disease: CT, MR and PET imaging findings.

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    BACKGROUND: Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis with characteristic radiological and histological features. This entity is defined by a mononuclear infiltrate consisting of lipid-laden, foamy histiocytes that stain positively for CD68 and negatively for CD1a. Osseous involvement is constant and characteristic. Extra-osseous lesions may affect the retroperitoneum, lungs, skin, heart, brain and orbits. METHODS: Both radiography and technetium-99m bone scintigraphy may reveal osteosclerosis of the long bones, which is a typical finding in ECD. For visceral involvement, computed tomography (CT) is most useful, while magnetic resonance (MR) imaging is more sensitive for cardiovascular lesions; 2-[fluorine-18] fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/CT scanning is useful in assessing the extension of ECD lesions. RESULTS: The prognosis is extremely variable and is often worse when there is cardiovascular system involvement. Diagnosis is based on the combination of radiographic, CT, MR imaging and nuclear medicine features and a nearly pathognomonic immunohistochemical profile. CONCLUSION: The aims of this work are to perform a systematic review of Erdheim-Chester disease as seen on imaging of the chest, abdomen and musculoskeletal system and to discuss the diagnostic workup and differential diagnoses according to the imaging presentation. Teaching points • Bone involvement is usually present in patients, and the imaging findings are pathognomonic of ECD. • The circumferential periaortic infiltration may extend to its branches, sometimes becoming symptomatic. • Cardiac involvement-the pericardium, right atrium and auriculoventricular sulcus-worsens its prognosis. • Perirenal infiltration extending to the proximal ureter is highly suggestive of this disease

    The role of point-like topological excitations at criticality: from vortices to global monopoles

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    We determine the detailed thermodynamic behavior of vortices in the O(2) scalar model in 2D and of global monopoles in the O(3) model in 3D. We construct new numerical techniques, based on cluster decomposition algorithms, to analyze the point defect configurations. We find that these criteria produce results for the Kosterlitz-Thouless temperature in agreement with a topological transition between a polarizable insulator and a conductor, at which free topological charges appear in the system. For global monopoles we find no pair unbinding transition. Instead a transition to a dense state where pairs are no longer distinguishable occurs at T<Tc, without leading to long range disorder. We produce both extensive numerical evidence of this behavior as well as a semi-analytic treatment of the partition function for defects. General expectations for N=D>3 are drawn, based on the observed behavior.Comment: 14 pages, REVTEX, 13 eps figure

    Methods of isolation and identification of pathogenic and potential pathogenic bacteria from skins and tannery effluents

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    Currently there is no standard protocol available within the leather industry to isolate and identify pathogenic bacteria from hides, skins or tannery effluent. This study was therefore carried out to identify simple but effective methods for isolation and identification of bacterial pathogens from the effluent and skins during leather processing. Identification methods based on both phenotypic and genotypic characteristics were investigated. Bacillus cereus and Pseudomonas aeruginosa were used as indicator bacteria to evaluate the isolation and identification methods. Decontaminated calfskins were inoculated with a pure culture of the above mentioned bacterial species followed by a pre-tanning and chromium tanning processes. Effluent samples were collected and skins were swabbed at the end of each processing stage. Bacterial identification was carried out based on the phenotypic characteristics; such as colony appearance on selective solid media, cell morphology following a standard Gram-staining and spore staining techniques, and biochemical reactions, e.g., the ability of a bacterial species to ferment particular sugars and ability to produce certain enzymes. Additionally, an identification system based on bacterial phenotypic characteristics, known as Biolog® system was applied. A pulsed-filed gel electrophoresis (PFGE) method for bacterial DNA fingerprinting was also evaluated and used for the identification of the inoculated bacteria. The methods described in the study were found to be effective for the identification of pathogenic bacteria from skins and effluent

    Turning catalytically active pores into active pumps

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    We develop a semi-analytical model of self-diffusioosmotic transport in active pores, which includes advective transport and the inverse chemical reaction which consumes solute. In previous work (Phys. Rev. Lett. 129, 188003, 2022), we have demonstrated the existence of a spontaneous symmetry breaking in fore-aft symmetric pores that enables them to function as a micropump. We now show that this pumping transition is controlled by three timescales. Two timescales characterize advective and diffusive transport. The third timescale corresponds to how long a solute molecule resides in the pore before being consumed. Introducing asymmetry to the pore (either via the shape or the catalytic coating) reveals a second type of advection-enabled transitions. In asymmetric pores, the flow rate exhibits discontinuous jumps and hysteresis loops upon tuning the parameters that control the asymmetry. This work demonstrates the interconnected roles of shape and catalytic patterning in the dynamics of active pores, and shows how to design a pump for optimum performance

    Thermoelectric response of Fe1+y_{1+y}Te0.6_{0.6}Se0.4_{0.4}: evidence for strong correlation and low carrier density

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    We present a study of the Seebeck and Nernst coefficients of Fe1+y_{1+y}Te1−x_{1-x}Sex_{x} extended up to 28 T. The large magnitude of the Seebeck coefficient in the optimally doped sample tracks a remarkably low normalized Fermi temperature, which, like other correlated superconductors, is only one order of magnitude larger than Tc_c. We combine our data with other experimentally measured coefficients of the system to extract a set of self-consistent parameters, which identify Fe1+y_{1+y}Te0.6_{0.6}Se0.4_{0.4} as a low-density correlated superconductor barely in the clean limit. The system is subject to strong superconducting fluctuations with a sizeable vortex Nernst signal in a wide temperature window.Comment: 4 pages including 4 figure

    Perceptions of sexual abuse in sport: A qualitative study in the Portuguese sports community

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    Child sexual abuse is a complex issue that can take place in different contexts. Sports settings have specific features which pose increased risk for sexual abuse to occur. Recently, a country-specific roadmap for effective child safeguarding in sport was launched. Considering the need to achieve a comprehensive picture of violence against children in sports settings in Portugal, we analyzed the perceptions of the sports community in Portugal regarding child sexual abuse, its victims and perpetrators, and the specific risk factors in sports settings, as studies about this specific topic are scarce at the national level. A descriptive exploratory study was conducted using an online questionnaire with open-ended questions. Three hundred participants, i.e., sports managers, coaches, and athletes over 18 years of age (M = 33.13; SD = 13.062), of which 55.7% were female, answered. A thematic analysis of these data was conducted using NVivo software. Inter-rater agreement was strong for almost all variables. Results indicated that sexual abuse is perceived as being associated with physical and emotional abusive behaviors for which there is no consent from the victim, in a relationship that is guided by a relationship with power imbalances. Victims were mainly perceived as being female children, and perpetrators as adult males in a powerful position over the victim. As to possible signs of sexual abuse victimization, results showed that the participants identify behaviors, such as isolation, and physical evidence, such as marks and injuries. Risk factors specific to sports setting included the physical contact involved in many modalities, as well as the close and trustful relationship established between coach and athlete. Results are in line with previous studies showing that coaches, athletes, and sports managers share a common understanding of sexual abuse, although not always accurate. These results shed light on important practical and policy implications relevant to country-specific sport policies for effectively safeguarding children.info:eu-repo/semantics/publishedVersio

    The use of genre analysis in the design of electronic meeting systems

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    WOS:000237136400002 (Nº de Acesso Web of Science)Introduction. Genre analysis is an approach to study communication patterns and thus it can be applied to the specific context of meetings. This research investigates the use of genre analysis in the design of electronic meeting systems. Background. The primary goal of genre analysis is to understand how virtual communities use digital communication to collaborate. This knowledge is fundamental for informing the design of information systems, particularly in areas where communication and informality are paramount. However, the research literature does not report any experiments where genre analysis has been used to inform the design of electronic meeting systems. Problems. The paper tackles the following common problems found in current electronic meeting systems: (1) reduced organizational integration, neglecting many contextual cues and explaining factors necessary to make meeting outcomes usable within the organization; (2) lack of support to specific communities of users, stressing the dependency on a facilitator to configure and manage the technology; and (3) lack of support to meeting occurrences that span long time periods. Conclusions. The paper describes how genre analysis was used to develop electronic meeting systems for several organizations and meeting genres. It covers the complete design process, from genre elicitation to validation. The obtained results demonstrate that the genre approach produces electronic meeting systems focused on organizational integration, pre-configured to communities of users, supporting long-term usage and added organizational value

    Hábitos alimentares de utentes adultos do centro de saúde de Castelo Branco

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    Em Portugal têm vindo a revelar-se alguns erros alimentares praticados por grande parte da população. Esses erros cometem-se por excesso de ingestão de certo tipo de alimentos que, consequentemente, levam a problemas no organismo, como é o caso da obesidade, diabetes, hipertensão arterial, entre outras doenças
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