Influence of linseed oil on the microstructure and composition of lime and lime-metakaolin pastes after a long curing time

This study investigates the effect of linseed oil on the microstructure of lime and lime-metakaolin pastes after 68 months of curing under controlled conditions. The hydrophobicity imparted by linseed oil to the pastes’ bulk was confirmed by measuring water drops’ contact angle. The results of thermal analysis, X-ray powder diffraction, and Fourier transform infrared spectroscopy showed that linseed oil significantly hindered the carbonation reaction in both lime and lime-metakaolin pastes and promoted the development of amorphous phases. The obtained results also indicated that linseed oil could foster the pozzolanic reaction in the lime-metakaolin system by stabilizing and/or promoting the development of hydration products resulting in reduced shrinkage in comparison with the reference

Preliminary study of the pozzolanic activity of dumped mine wastes obtained from the North Bohemian basin in the Czech Republic

Three dumped raw materials, a tuff and two bentonites, obtained from two mining sites at the North Bohemian basin in the Czech Republic, have been studied in order to evaluate them as pozzolanic admixtures in lime mortars for employment in restoration of cultural heritage objects. After thermal activation (800 °C; 5 h), their pozzolanic properties were compared with those of commercial metakaolin. Quantitative phase analysis with the Rietveld method from X-ray powder diffraction patterns, morphological observations, as well as the Frattini and the modified Chapelle tests were performed. In addition, lime mortars, incorporating the fired materials, were prepared and subjected to simultaneous thermal analysis after a 28-day initial curing (20 ± 1 °C; 60 ± 5 % RH). The results showed that all three materials possess pozzolanic activity. However, when employed in lime mortars they did not result in formation of pozzolanic reaction products. Two methods were proposed to improve their reactivity; grinding to obtain finer particle size and removal of quartz content where necessary

Synthetic calcium carbonate improves the effectiveness of treatments with nanolime to contrast decay in highly porous limestone

Three synthetized polymorphs of calcium carbonate have been tested in combination with the suspension of nanolime particles as potential consolidating agents for contrasting stone decay and overcome some of the limitations of nanolime agents when applied to substrates with large porosity. The modifications induced in the pore network of the Maastricht limestone were analyzed with microscopy and in a non-invasive fashion with small angle neutron scattering and synchrotron radiation micro-computed tomography. A reduction in porosity and pore accessibility at the micrometric scale was detected with the latter technique, and ascribed to the improved pore-filling capacity of the consolidation agent containing CaCO3 particles. These were found to be effectively bound to the carbonated nanolime, strengthening the pore-matrix microstructure. Penetration depth and positive effect on porosity were found to depend on the particle size and shape. Absence of significant changes in the fractal nature of the pore surface at the nanoscale, was interpreted as indication of the negligible contribution of nanolime-based materials in the consolidation of stones with large porosity. However, the results indicate that in such cases, their effectiveness may be enhanced when used in combination with CaCO3 particles, owing to the synergic effect of chemical/structural compatibility and particle size distribution

Supporting early communication skills of children with developmental disorders in South Africa : caregiver and clinician perspectives about mobile health applications

Using a mobile health application (i.e., app) to empower primary caregivers of young children with developmental disorders in low- and middle-income countries is opening up new avenues for early childhood intervention. Thirteen caregivers and 10 speech-language pathologists participated in 3 focus groups to explore their perspectives about the potential benefits and suitability of a mobile health app as part of intervention, its features, the likelihood of using and recommending it, as well as potential pitfalls to be avoided. Both participant groups were generally positive, although there was little overlap between their responses. Caregivers generally focused on increased knowledge and skills (of all family members), as well as on empowerment and reduced costs. Speech-language pathologists, on the other hand, focused on how current service delivery would be enriched by increasing the dosage of therapy and enhancing parental cooperation. They also expected that the reach of service delivery would be expanded as more children and caregivers could potentially benefit. Although technology (i.e., mobile apps) could open up new possibilities for service delivery in this population, the perspectives of all stakeholder groups should be considered to ensure successful adoption of such technologies.The United States National Institute of Deafness and Other Communication Disorders (NIDCD) through the National Institutes of Health (NIH) Fogarty International Center (FIC) mhealth initiative to Georgia State University.http://www.iycjournal.com2021-10-01hj2020Centre for Augmentative and Alternative Communication (CAAC

Structural insights into the human RyR2 N-terminal region involved in cardiac arrhythmias

Human ryanodine receptor 2 (hRyR2) mediates calcium release from the sarcoplasmic reticulum, enabling cardiomyocyte contraction. The N-terminal region of hRyR2 (amino acids 1–606) is the target of >30 arrhythmogenic mutations and contains a binding site for phosphoprotein phosphatase 1. Here, the solution and crystal structures determined under near-physiological conditions, as well as a homology model of the hRyR2 N-terminal region, are presented. The N-terminus is held together by a unique network of interactions among its three domains, A, B and C, in which the central helix (amino acids 410–437) plays a prominent stabilizing role. Importantly, the anion-binding site reported for the mouse RyR2 N-terminal region is notably absent from the human RyR2. The structure concurs with the differential stability of arrhythmogenic mutations in the central helix (R420W, I419F and I419F/R420W) which are owing to disparities in the propensity of mutated residues to form energetically favourable or unfavourable contacts. In solution, the N-terminus adopts a globular shape with a prominent tail that is likely to involve residues 545–606, which are unresolved in the crystal structure. Docking the N-terminal domains into cryo-electron microscopy maps of the closed and open RyR1 conformations reveals C atom movements of up to 8 A ° upon channel gating, and predicts the location of the leucine– isoleucine zipper segment and the interaction site for spinophilin and phosphoprotein phosphatase 1 on the RyR surface

Translating a health behavior change intervention for delivery to 2-year college students: the importance of formative research

Young adults are at risk for weight gain in the transition to independent adulthood; 2-year college students are at greater risk and understudied relative to 4-year students. This project conducted formative research for a randomized controlled weight gain prevention trial among 2-year college students, to ensure appropriateness of content and delivery of a curriculum originally developed for 4-year college students. Data were collected from community college students, faculty, and staff from October 2009 to August 2011. Work included focus groups and key informant interviews, curriculum pilot testing, and social network and support website beta testing. Based on focus groups and interviews, program content, course delivery modes, and communication channels were adjusted to meet population interests and preferences. The course was delivered successfully in pilot testing, and the website was received well by beta testers. Formative work successfully guided program adaptations to address population needs

A 2-year young adult obesity prevention trial in the US: Process evaluation results

Our objective was to conduct a process evaluation of the CHOICES (Choosing Healthy Options in College Environments and Settings) study, a large, randomized, controlled trial designed to prevent unhealthy weight gain in young adults (aged 18–35) attending 2-year community colleges in the USA. The 24-month intervention consisted of participation in an academic course and a social networking and support website. Among intervention participants, completion rates for most course activities were >80%, reflecting a high level of dose received. Course retention and participant satisfaction were also high. Engagement results, however, were mixed with less than half of participants in the online and hybrid sections of the course reporting that they interacted with course materials ≥3 h/week, but 50–75% reporting that they completed required lessons ‘all/very thoroughly’. Engagement in the website activities was also mixed with more than half of intervention participants logging onto the website during the first month, but then declining to 25–40% during the following 23 months of the intervention. Intervention engagement is a challenge of online interventions and a challenge of working with the young adult age group in general. Additional research is needed to explore strategies to support engagement among this population, particularly for relatively long intervention durations

Parent-implemented augmented communication intervention and young children with Down syndrome: an exploratory report

IntroductionYoung children with Down syndrome (DS) present with speech and language impairments very early in childhood. Historically, early language intervention for children with DS included manual signs, though recently there has been an interest in the use of speech-generating devices (SGDs). This paper examines the language and communication performance of young children with DS who participated in parent-implemented communication interventions that included SGDs. Specifically, we compared the functional vocabulary usage and communication interaction skills of children with DS who received augmented communication interventions (AC) that included an SGD with those children with DS who received spoken communication intervention (SC).MethodsTwenty-nine children with DS participated in this secondary data analysis. These children were part of one of two longitudinal RCT studies investigating the effectiveness of parent-implemented augmented communication interventions in a larger sample of 109 children with severe communication and language impairments.ResultsThere were significant differences between children with DS in the AC and SC groups in terms of the number and proportion of functional vocabulary targets used and the total vocabulary targets provided during the intervention at sessions 18 (lab)and 24 (home).DiscussionOverall, the AC interventions provided the children with a way to communicate via an SGD with visual-graphic symbols and speech output, while the children in the SC intervention were focused on producing spoken words. The AC interventions did not hinder the children’s spoken vocabulary development. Augmented communication intervention can facilitate the communication abilities of young children with DS as they are emerging spoken communicators