Simple torsion test for shear moduli determination of orthotropic composites

By means of torsion tests performed on test specimens of the same material having a minimum of two different cross sections (flat sheet of different widths), the effective in-plane (G13) and out-of-plane (G23) shear moduli were determined for two composite materials of uniaxial and angleply fiber orientations. Test specimens were 16 plies (nominal 2 mm) thick, 100 mm in length, and in widths of 6.3, 9.5, 12.5, and 15.8 mm. Torsion tests were run under controlled deflection (constant angle of twist) using an electrohydraulic servocontrolled test system. In-plane and out-of-plane shear moduli were calculated from an equation derived in the theory of elasticity which relates applied torque, the torsional angle of twist, the specimen width/thickness ratio, and the ratio of the two shear moduli G13/G23. Results demonstrate that torsional shear moduli, G23 as well as G13, can be determined by simple torsion tests of flat specimens of rectangular cross section. Neither the uniaxial nor angleply composite material were transversely isotropic

The Effectiveness of a 'Train the Trainer' Model of Resuscitation Education for Rural Peripheral Hospital Doctors in Sri Lanka

BACKGROUND Sri Lankan rural doctors based in isolated peripheral hospitals routinely resuscitate critically ill patients but have difficulty accessing training. We tested a train-the-trainer model that could be utilised in isolated rural hospitals. METHODS Eight selected rural hospital non-specialist doctors attended a 2-day instructor course. These "trained trainers" educated their colleagues in advanced cardiac life support at peripheral hospital workshops and we tested their students in resuscitation knowledge and skills pre and post training, and at 6- and 12-weeks. Knowledge was assessed through 30 multiple choice questions (MCQ), and resuscitation skills were assessed by performance in a video recorded simulated scenario of a cardiac arrest using a Resuci Anne Skill Trainer mannequin. RESULTS/DISCUSSION/CONCLUSION Fifty seven doctors were trained. Pre and post training assessment was possible in 51 participants, and 6-week and 12-week follow up was possible for 43, and 38 participants respectively. Mean MCQ scores significantly improved over time (p<0.001), and a significant improvement was noted in "average ventilation volume", "compression count", and "compressions with no error", "adequate depth", "average depth", and "compression rate" (p<0.01). The proportion of participants with compression depth ≥40mm increased post intervention (p<0.05) and at 12-week follow up (p<0.05), and proportion of ventilation volumes between 400-1000mls increased post intervention (p<0.001). A significant increase in the proportion of participants who "checked for responsiveness", "opened the airway", "performed a breathing check", who used the "correct compression ratio", and who used an "appropriate facemask technique" was also noted (p<0.001). A train-the-trainer model of resuscitation education was effective in improving resuscitation knowledge and skills in Sri Lankan rural peripheral hospital doctors. Improvement was sustained to 12 weeks for most components of resuscitation knowledge and skills. Further research is needed to identify which components of training are most effective in leading to sustained improvement in resuscitation.This research was funded by an international collaborative research Wellcome Trust/National Health and Medical Research Council grant GR071669. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Strength Reduction in Electrical and Elastic Networks

Particular aspects of problems ranging from dielectric breakdown to metal insu- lator transition can be studied using electrical o elastic networks. We present an expression for the mean breakdown strength of such networks.First, we intro- duce a method to evaluate the redistribution of current due to the removal of a finite number of elements from a hyper-cubic network of conducatances.It is used to determine the reduction of breakdown strength due to a fracture of size $\kappa$.Numerical analysis is used to show that the analogous reduction due to random removal of elements from electrical and elastic networks follow a similar form.One possible application, namely the use of bone density as a diagnostic tools for osteorosporosis,is discussed.Comment: one compressed file includes: 9 PostScrpt figures and a text fil

Perceptions of successful ageing in Sri Lankan older people: A qualitative study

Background. This study explores the opinions and views of Sri Lankan older people about successful ageing. Methods. 30 females and 28 males aged 63 to 85 (median, 69) years recruited from 4 locations in a southern district in Sri Lanka participated in 8 focus groups (4 in rural and 4 in urban). Each focus group contained a single sex of participants so as to enable women to express their views freely. Discussions were audio recorded and transcribed. Transcripts were independently reviewed by the researchers and recurring themes were identified and coded using a content analysis approach. Analytic memos were prepared to elaborate on the themes and identify exemplary quotes. Results. Four major themes related to successful ageing were identified: (1) being physically active and healthy, (2) being free from burdens and responsibilities, (3) having fulfilling family relationships, and (4) pursuing spiritual development. In addition, a living environment conducive to physical activity and charitable work, and living with children were identified as facilitators of successful ageing. Economic hardship, having unsettled and vulnerable children, disrespect by the community, limited access to health care, and negative attitudes of health service providers towards older people were identified as important barriers to successful ageing. Conclusions. Strategies that can improve the quality of life of Sri Lankan older people include increased community awareness of population ageing and expectations of older people, a strengthened primary health care system that caters to their needs, and development of support systems for home-based care

Care-giving expectations and challenges among elders and their adult children in Southern Sri Lanka

The elderly population in Sri Lanka is growing rapidly. Elders are traditionally cared for in the homes of their adult children, but the shifting socio-economic environment in Sri Lanka challenges this arrangement. This paper describes the dynamics of elder-care-giver relationships in Southern Sri Lanka. Data included four focus group discussions and five in-depth interviews with elderly, and ten in-depth interviews with adult children of the elderly. Discussion guide topics included care-giving arrangements, and roles/responsibilities of elders and care-givers. Using a grounded theory approach, a comprehensive analytic memo was developed and discussed to explore emerging themes on the care-giver dynamic. Both elders and care-givers felt that elders should be taken care of in the home by their children. They pointed to a sense of duty and role modelling of parental care-giving that is passed down through generations. Even as elders desired support from their children, they feared losing their independence, and saw financial autonomy as important for maintaining relationship balance. Care-giving challenges included: households where both the adult child and his/her spouse worked outside the home; households where elders had a disproportionate amount of household work; economically stressed households; and lack of direct communication between elders and care-givers regarding conflicts. Results point to strong values around caring for elderly in the home, but identify challenges to this arrangement in the future

A dynamical model reveals gene co-localizations in nucleus

Co-localization of networks of genes in the nucleus is thought to play an important role in determining gene expression patterns. Based upon experimental data, we built a dynamical model to test whether pure diffusion could account for the observed co-localization of genes within a defined subnuclear region. A simple standard Brownian motion model in two and three dimensions shows that preferential co-localization is possible for co-regulated genes without any direct interaction, and suggests the occurrence may be due to a limitation in the number of available transcription factors. Experimental data of chromatin movements demonstrates that fractional rather than standard Brownian motion is more appropriate to model gene mobilizations, and we tested our dynamical model against recent static experimental data, using a sub-diffusion process by which the genes tend to colocalize more easily. Moreover, in order to compare our model with recently obtained experimental data, we studied the association level between genes and factors, and presented data supporting the validation of this dynamic model. As further applications of our model, we applied it to test against more biological observations. We found that increasing transcription factor number, rather than factory number and nucleus size, might be the reason for decreasing gene co-localization. In the scenario of frequency-or amplitude-modulation of transcription factors, our model predicted that frequency-modulation may increase the co-localization between its targeted genes

The NCI-60 methylome and its integration into CellMiner

A unique resource for systems pharmacology and genomic studies is the NCI-60 cancer cell line panel, which provides data for the largest publicly available library of compounds with cytotoxic activity (∼21,000 compounds), including 108 FDA-approved and 70 clinical trial drugs as well as genomic data, including whole-exome sequencing, gene and miRNA transcripts, DNA copy number, and protein levels. Here, we provide the first readily usable genome-wide DNA methylation database for the NCI-60, including 485,577 probes from the Infinium HumanMethylation450k BeadChip array, which yielded DNA methylation signatures for 17,559 genes integrated into our open access CellMiner version 2.0 (https://discover.nci.nih.gov/cellminer). Among new insights, transcript versus DNA methylation correlations revealed the epithelial/mesenchymal gene functional category as being influenced most heavily by methylation. DNA methylation and copy number integration with transcript levels yielded an assessment of their relative influence for 15,798 genes, including tumor suppressor, mitochondrial, and mismatch repair genes. Four forms of molecular data were combined, providing rationale for microsatellite instability for 8 of the 9 cell lines in which it occurred. Individual cell line analyses showed global methylome patterns with overall methylation levels ranging from 17% to 84%. A six-gene model, including PARP1, EP300, KDM5C, SMARCB1, and UHRF1 matched this pattern. In addition, promoter methylation of two translationally relevant genes, Schlafen 11 (SLFN11) and methylguanine methyltransferase (MGMT), served as indicators of therapeutic resistance or susceptibility, respectively. Overall, our database provides a resource of pharmacologic data that can reinforce known therapeutic strategies and identify novel drugs and drug targets across multiple cancer type