Analysis of temperature effects near mode I cracks in glassy polymers

A previous isothermal study has shown that the toughness of glassy polymers is governed by the competition between shear yielding and crazing. The present work aims at investigating loading rates for which thermal effects need to be accounted for. The influence of the heat coming from the viscoplastic shear yielding and from crazing on their competition and on the toughness is examined. Crazing is shown to be the dominant heat source, and the dependence of the craze properties on temperature appears to be key in controlling the toughness of the material.

Towards the Holodeck: fully immersive virtual reality visualisation of scientific and engineering data

In this paper, we describe the development and operating principles of an immersive virtual reality (VR) visualisation environment that is designed around the use of consumer VR headsets in an existing wide area motion capture suite. We present two case studies in the application areas of visualisation of scientific and engineering data. Each of these case studies utilise a different render engine, namely a custom engine for one case and a commercial game engine for the other. The advantages and appropriateness of each approach are discussed along with suggestions for future work

Are Repeatedly Extorted Businesses Different? A Multilevel Hurdle Model of Extortion Victimization

Objectives: Research consistently shows that crime concentrates on a few repeatedly victimized places and targets. In this paper we examine whether the same is true for extortion against businesses. We then test whether the factors that explain the likelihood of becoming a victim of extortion also explain the number of incidents suffered by victimized businesses. The alternative is that extortion concentration is a function of event dependence. Methods: Drawing on Mexico’s commercial victimization survey, we determine whether repeat victimization occurs by chance by comparing the observed distribution to that expected under a Poisson process. Next, we utilize a multilevel negative binomial-logit hurdle model to examine whether area- and business-level predictors of victimization are also associated with the number of repeat extortions suffered by businesses. Results: Findings suggest that extortion is highly concentrated, and that the predictors of repeated extortion differ from those that predict the likelihood of becoming a victim of extortion. While area-level variables showed a modest association with the likelihood of extortion victimization, they were not significant predictors of repeat incidents. Similarly, most business-level variables significantly associated with victimization risk showed insignificant (and sometimes contrary) associations with victimization concentration. Overall, unexplained differences in extortion concentration at the business-level were unaffected by predictors of extortion prevalence. Conclusions: The inconsistent associations of predictors across the hurdle components suggest that extortion prevalence and concentration are fueled by two distinct processes, an interpretation congruent with theoretical expectations regarding extortion that considers that repeats are likely fueled by a process of event dependence

Therapeutic strategies for Huntington’s disease

PURPOSE AND REVIEW: Huntington's disease is a fatal autosomal dominant neurodegenerative disorder caused by a trinucleotide expansion in the HTT gene, and current therapies focus on symptomatic treatment. This review explores therapeutic approaches that directly target the pathogenic mutation, disrupt HTT mRNA or its translation. RECENT FINDINGS: Zinc-finger transcription repressors and CRISPR-Cas9 therapies target HTT DNA, thereby preventing all downstream pathogenic mechanisms. These therapies, together with RNA interference (RNAi), require intraparenchymal delivery to the brain in viral vectors, with only a single delivery potentially required, though they may carry the risk of irreversible side-effects. Along with RNAi, antisense oligonucleotides (ASOs) target mRNA, but are delivered periodically and intrathecally. ASOs have safely decreased mutant huntingtin protein (mHTT) levels in the central nervous system of patients, and a phase 3 clinical trial is currently underway. Finally, orally available small molecules, acting on splicing or posttranslational modification, have recently been shown to decrease mHTT in animal models. SUMMARY: Huntingtin-lowering approaches act upstream of pathogenic mechanisms and therefore have a high a priori likelihood of modifying disease course. ASOs are already in late-stage clinical development, whereas other strategies are progressing rapidly toward human studies

A taxonomy for planning and designing smart mobility services

The development of smart mobility initiatives requires specialized and contextualized policies addressing the needs and interests of many stakeholders involved. Since the development of such policies is challenging, there is a need to learn from the experience of many cities around the world offering efficient and successfully adopted smart mobility services. However, in practice, the information provided about such initiatives is shallow and unstructured. To address this issue, we study the state of the art in mobility services, reviewing scientific publications and 42 smart mobility services delivered by nine smart cities around the world, and we propose a taxonomy for planning and designing smart mobility services. The taxonomy provides a common vocabulary to discuss and share information about such services. It comprises eight dimensions: type of services, maturity level, users, applied technologies, delivery channels, benefits, beneficiaries, and common functionality. The contribution of the proposed taxonomy is to serve as a tool for guiding policy makers by identifying a spectrum of mobility services that can be provided, to whom, what technologies can be used to deliver them, and what is the delivered public value so to justify their implementation. In addition, the taxonomy can also assist researchers in further developing the domain. By identifying common functionality, it could also help Information Technology (IT) teams in building and maintaining smart mobility services. Finally, we further discuss usage scenarios of the taxonomy by policy makers, IT staff and researchers.NORTE-01-0145-FEDER-000037, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (EFDR). The first author is also supported by the Portuguese funding agency, FCT, under grant PD/BD/52238/201

Immersive visualisation of 3-dimensional neural network structures

No abstract

Biogenic silver nanoparticles: Understanding the antimicrobial mechanism using Confocal Raman Microscopy

The antimicrobial properties of silver nanoparticles (AgNPs) have made them ubiquitous in a number of real-world industrial applications; however, the antimicrobial mode of action of biogenic AgNPs is not entirely understood. The use of Raman spectroscopy can provide molecular fingerprint information on various chemical and biochemical components in complex systems like microbial cultures, without the need for any complex sample pre-treatment. Consequently, the antimicrobial mechanism of AgNPs can be inferred through morphological and compositional changes of microbial cells that are monitored via changes in Raman band profiles. Here we show the synthesis of biogenic AgNPs using the extracellular cell-free filtrates of Penicillium expansum. The antimicrobial activity of the Penicillium expansum synthesized silver nanoparticles (hereafter PeNPs) was evaluated and the interactions between the nanoparticles and Escherichia coli were studied using Transmission Electron Microscopy (TEM) and Environmental Scanning Electron Microscopy (ESEM), showing the attachment of PeNPs to the surface of the bacteria and rupture of the bacterial cell membrane. Importantly, we show how Confocal Raman Microscopy can be used as an innovative approach to study the antimicrobial mechanisms, the results of which confirm that the PeNPs induce damage to bacterial and fungal cells, resulting in critical changes to polysaccharides, lipids, proteins and nucleic acids

Sicole: diagnóstico y tratamiento computarizado de la dislexia en español

En este articulo realizamos un recorrido sobre las investigaciones más relevantes en el campo de la tecnología aplicada al diseño instruccional, las cuales marcan las pautas de diseño de los programas educativos actuales y presentamos los criterios pedagógicos y tecnológicos que hemos seguido en el diseño e implementación de un ITS para la diagnóstico, evaluación y tratamiento de niños con Dislexia en el lenguaje español. Este trabajo se halla dentro del marco de un proyecto de investigación interdisciplinar titulado SICOLE, formado por psicólogos, pedagogos e informáticos.In this paper we present the most significant researchers in the area of technology applied to instructional design. Also, we describe the pedagogical and technological principles followed in the design and implementation of an Intelligent Tutorial System for assessment and treatment of dyslexic children in Spanish language. This work is result of a multidisciplinary research with engineers, teachers and psychologists and it has been funded by «Fondos Europeos para el Desarrollo Regional» (FEDER), 1FD97-1140, and the «Dirección General de Investigación Científica y Técnica» (DIGICYT). This package has being used in several Spanish schools as part of its validation process