Locating a weak change using diffuse waves (LOCADIFF) : theoretical approach and inversion procedure

We describe a time-resolved monitoring technique for heterogeneous media. Our approach is based on the spatial variations of the cross-coherence of coda waveforms acquired at fixed positions but at different dates. To locate and characterize a weak change that occurred between successive acquisitions, we use a maximum likelihood approach combined with a diffusive propagation model. We illustrate this technique, called LOCADIFF, with numerical simulations. In several illustrative examples, we show that the change can be located with a precision of a few wavelengths and its effective scattering cross-section can be retrieved. The precision of the method depending on the number of source receiver pairs, time window in the coda, and errors in the propagation model is investigated. Limits of applications of the technique to real-world experiments are discussed.Comment: 11 pages, 14 figures, 1 tabl

Tuberculosis/HIV/AIDS coinfection in Porto Alegre, RS/Brazil - invisibility and silencing of the most affected groups

OBJECTIVE: To analyze how belonging to certain social groups contributes to constituting the vulnerabilities associated with illnesses due to tuberculosis/HIV/AIDS coinfection. METHODOLOGYThis is a qualitative study carried out in the city of Porto Alegre, state of Rio Grande do Sul, in regions of high social vulnerability. Twenty coinfected people were interviewed in specialized health services between August and December 2016. The analysis was based on the frameworks The Sound of Silence and Vulnerability and Human Rights. RESULTS: Socioeconomic conditions were decisive for the constitution of the vulnerability conditions. Processes of people invisibilization, and the silencing of their voices, in a scenario marked by economic, racial and gender inequalities, contributed for their health needs not to be understood and effectively taken into account in the services actions. FINAL CONSIDERATIONS: The more effective strategies are to legitimize voices and to understand the needs of those affected by coinfection, the greater the chances that programmatic responses to the problem will be successful

Moisture degradation of open-faced single lap joints

To obtain experimental data in short time on the degradation of adhesives exposed to moisture, a valuable technique is represented using the open-face configuration. With this technique, a layer of adhesive is first applied on one adherend and exposed to the humid environment; then, the second adherend is bonded and the joint can now undergo mechanical testing. Apart from the acceleration of moisture uptake which is obtained due to the larger area exposed, a further advantage is the uniformity of degradation. A further acceleration can be obtained by adding a hygroscopic contaminant at the adhesive/adherend interface, which speeds up moisture uptake and accentuates the interfacial nature of the failure. The main aim of this work was to evaluate the decay of the mechanical strength in the absence or presence of a contaminating agent. The specimens studied were single lap joints, tested under static shear loading. Two sets of specimens were considered; in the first set, the adhesive was applied in standard way and in the second set, the adhesive/adherend interface was contaminated with droplets of CaCl2 aqueous solution. Both sets were subjected to humid and warm environment (100% relative humidity, 50 °C). After the desired exposure times in the range 1–5 weeks, groups of specimens were dried and bonding of the second adherend was carried out. Then, mechanical testing was performed; the fractured surfaces were examined by scanning electron microscopy. The results show that before degradation the failure type is cohesive, but it changes to interfacial failure as the degradation proceeds. Uncontaminated specimens exhibit gradual degradation during the exposure time; contaminated specimens achieve almost half of the degradation in less than one week; after that, the process continues at lower speed and at the end of the observed period both methods show similar values of failure loads. Additional tests were carried out to assess the moisture absorption in the adhesive layer and relate it to the exposure time

Women’s experiences of gynaecological consultations – uncovering its technological toolboxes: challenges in a Brazilian context

Historically, the medical definition of women as an object of biomedical knowledge has restricted the way by which gynecology is understood. In Brazil’s Unified Health System (Sistema Unificado de Saúde – SUS, in Portuguese), it is the responsibility of gynaecological care services to identify, diagnose and treat reproductive related conditions. However, gynaecological consultations are based predominantly on a medicalised model of diagnosis, treatment and disease management which often fails to address the wider determinants of women’s reproductive health and its impact on their general health and life chances. This paper is focused on the way the Brazilian health system has responded to women’s health needs in gynaecological consultations, given its central role in maintaining and promoting women’s health. it explores variations between “what should be” and “what is” offered to Brazilian women in gynaecological consultations. The authors argue that while gynaecological consultations in Brazil (and elsewhere) are currently restricted to programmatic targets, complaints and symptoms associated with sexual and reproductive functions; consultations could be used to respond to women’s needs, using a broader life course approach if a combination of health technologies ‘toolboxes’ are employed. Implementation of care services utilising a ‘toolbox’ approach provides an opportunity to truly follow the principle of ‘integrality’, one of the doctrinal principles of the Brazilian health system, which furthermore could have application in women’s health care services elsewhere

Is Campus Involvement a Possible Cure for Student\u27s Mental Health Challenges?

College is a period of change for students. With the increasing level of difficulty, the challenge of fitting into a new environment, and finding healthy relationships, it can be very challenging for students to feel like they belong. Without creating valuable connections on campus, students can develop feelings of loneliness. The group membership, or lack thereof, also contributes to student’s success in academics. In addition to these feelings, many students also suffer from perfectionism. Maladaptive traits of perfectionism are detrimental to student health, and students with these traits experience fewer connection difficulties when they are socially connected on campus (Rice, K 2006). Student organizations and clubs on campus foster a sense of belonging, by providing a place for like-minded individuals to participate in what they enjoy. Our study investigated how belonging, loneliness, and perfectionism were related in a sample of students, ranging from the undergraduate to the doctoral level. By organizing students by the amount and type of their involvement, we examined how their participation affected our selected variables. From the results, we can recommend to incoming Boise State students what kinds of involvement will create feelings of belonging, and decreased levels of loneliness and maladaptive perfectionism

Application of the Material Point Method (MPM) to characterise the impact forces of granular landslides on rigid obstacles

This study deploys the Material Point Method (MPM) to investigate the soil pressures exerted on a 3D rigid obstacle partially obstructing a dry granular flow; a configuration not previously addressed in the literature on a numerical modelling basis. A 2D simulation is first developed and validated against a flume experiment that monitors the interaction of dry granular flows with retaining structures under varying flume angles. The model is then extended to 3D, enabling the adjustment of the obstacle's geometry to observe the impact of granular flows on impermeable rigid obstacles partially obstructing the soil material. The trend in the recorded soil forces exhibits an initial peak that occurs simultaneously with the first impact, followed by a steep degradation branch as the soil deposits in front of the structure, thus reducing the flow's dynamics. The numerical simulation is subsequently upscaled to ensure that macroscopic dimensional analysis adequately interprets small-scale numerical observations to mimic prototype conditions using the MPM approach. Simplified factors are finally derived to represent the response characteristics of large-scale simulations based on the original findings

A Procedure for Performing Nonlinear Pushover Analysis for Tsunami Loading to ASCE 7

The new ASCE 7-16 Chapter 6 offers a comprehensive and practical methodology for the design of structures for tsunami loads and effects. While it provides prescriptive tsunami loading and design requirements, Chapter 6 also allows for the use of performance-based nonlinear analysis tools. However, the specifics of load application protocol and system and component evaluation for such a nonlinear approach are not provided. This paper presents a procedure for performing nonlinear static pushover analysis for tsunami loading within the framework of the ASCE 7-16 standard. Through this approach, the user can both estimate the effective systemic lateral load-resisting capacity of a building and the local component demand. This enables the identification of deficiencies in structural elements with respect to the ASCE 7-16 standard acceptance criteria. To demonstrate the procedure, a prototypical reinforced concrete multistory building exposed to high tsunami hazard on the US Northwest Pacific Coast is assessed. This is a building with sufficient height to provide last-resort refuge for people having insufficient time to evacuate outside the inundation zone. The results of the nonlinear static pushover analyses show that the structural system has sufficient lateral strength to resist ASCE 7-16 prescribed tsunami loads, but fails the checks for component-based loading, with the exterior ground-story columns observed to fail in flexure and shear. The example demonstrates that use of the tsunami nonlinear static analysis procedure allows the identification of structural deficiencies such that a targeted strengthening of the building can be conducted (i.e., flexural and shear strengthening of the seaward and inland columns for the case study building presented), leading to significantly reduced costs

The role of the single interchains disulfide bond in tetanus and botulinum neurotoxins and the development of antitetanus and antibotulism drugs

A large number of bacterial toxins consist of active and cell binding protomers linked by an interchain disulfide bridge. The largest family of such disulfide-bridged exotoxins is that of the clostridial neurotoxins that consist of two chains and comprise the tetanus neurotoxins causing tetanus and the botulinum neurotoxins causing botulism. Reduction of the interchain disulfide abolishes toxicity, and we discuss the experiments that revealed the role of this structural element in neuronal intoxication. The redox couple thioredoxin reductase-thioredoxin (TrxR-Trx) was identified as the responsible for reduction of this disulfide occurring on the cytosolic surface of synaptic vesicles. We then discuss the very relevant finding that drugs that inhibit TrxR-Trx also prevent botulism. On this basis, we propose that ebselen and PX-12, two TrxR-Trx specific drugs previously used in clinical trials in humans, satisfy all the requirements for clinical tests aiming at evaluating their capacity to effectively counteract human and animal botulism arising from intestinal toxaemias such as infant botulism

A nonlinear static procedure for the tsunami design of a reinforced concrete building to the ASCE7 Standard

New ASCE 7-16 Chapter 6 offer a comprehensive and practical methodology for the design of structures for tsunami loads and effects. While they provide prescriptive tsunami loading and design requirements, they also allow for the use of performance-based analysis tools. However, no guidance is provided as to how the performance-based analysis should be performed. This paper presents an improved nonlinear static pushover procedure for the assessment of the nonlinear capacity of structures to tsunami, within the framework of the ASCE 7-16 provisions. For this purpose, a prototypical reinforced concrete multi-storey building exposed to high tsunami hazard in the US Northwest Pacific coast is assessed. This is a building with sufficient height to provide last-resort refuge for people having insufficient time to evacuate outside the inundation zone. Two different tsunami load discretisation methods are applied to investigate the structural capacity under tsunami systemic and component loading, respectively. The results of the nonlinear static pushover analyses show that the structural system has sufficient lateral strength to resist ASCE 7-16 prescribed tsunami loads. However, when component-based loading is considered, the seaward ground storey columns are observed to fail in shear, precipitating structural failure. This is in agreement with the ASCE 7-16 simplified systemic acceptance criteria, i.e. that the structure is unsafe for use as a refuge, and that it would require significant strengthening. However, the use of the VDPO provides information of what needs to be strengthened in order to improve the tsunami performance of the structure