178 research outputs found

    Ballistic Performance of Alumina and Zirconia-toughened Alumina Against 7.62 Armour Piercing Projectile

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    A study was carried out to compare the ballistic performance of high purity alumina and zirconia-toughened alumina (ZTA) using depth of penetration (DoP) test configuration against 7.62 mm armour piercing (AP) ammunition. The effect of tile thickness on the differential efficiency factor (DEF) was studied for tile thickness in the range of 3 mm to 6 mm for alumina tiles and 3 mm to 5 mm for ZTA tiles. The DEF is found to increase as tile thickness increases. An analysis on the failed shots showed that the residual shot weight does not follow a single linear relationship with ceramic tile thickness unlike the residual DoP for all thicknesses of tiles. Post-ballistic analysis on ceramic powder for particle size distribution was carried out and the results are presented.Defence Science Journal, Vol. 64, No. 5, September 2014, pp.477-483, DOI:http://dx.doi.org/10.14429/dsj.64.674

    Counting reducible, powerful, and relatively irreducible multivariate polynomials over finite fields

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    We present counting methods for some special classes of multivariate polynomials over a finite field, namely the reducible ones, the s-powerful ones (divisible by the s-th power of a nonconstant polynomial), and the relatively irreducible ones (irreducible but reducible over an extension field). One approach employs generating functions, another one uses a combinatorial method. They yield exact formulas and approximations with relative errors that essentially decrease exponentially in the input size.Comment: to appear in SIAM Journal on Discrete Mathematic

    Neuronal expression in Drosophila of an evolutionarily conserved metallophosphodiesterase reveals pleiotropic roles in longevity and odorant response

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    Evolutionarily conserved genes often play critical roles in organismal physiology. Here, we describe multiple roles of a previously uncharacterized Class III metallophosphodiesterase in Drosophila, an ortholog of the MPPED1 and MPPED2 proteins expressed in the mammalian brain. dMpped, the product of CG16717, hydrolyzed phosphodiester substrates including cAMP and cGMP in a metal-dependent manner. dMpped is expressed during development and in the adult fly. RNA-seq analysis of dMppedKO flies revealed misregulation of innate immune pathways. dMppedKO flies showed a reduced lifespan, which could be restored in Dredd hypomorphs, indicating that excessive production of antimicrobial peptides contributed to reduced longevity. Elevated levels of cAMP and cGMP in the brain of dMppedKO flies was restored on neuronal expression of dMpped, with a concomitant reduction in levels of antimicrobial peptides and restoration of normal life span. We observed that dMpped is expressed in the antennal lobe in the fly brain. dMppedKO flies showed defective specific attractant perception and desiccation sensitivity, correlated with the overexpression of Obp28 and Obp59 in knock-out flies. Importantly, neuronal expression of mammalian MPPED2 restored lifespan in dMppedKO flies. This is the first description of the pleiotropic roles of an evolutionarily conserved metallophosphodiesterase that may moonlight in diverse signaling pathways in an organism

    Raman Scattering Study of Ba-doped C60 with t1g States

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    Raman spectra are reported for Ba doped fullerides, BaxC60(x=3,4,and 6). The lowest frequency Hg modes split into five components for Ba4C60 and Ba6C60 even at room temperature, allowing us a quantitative analysis based on the electron-phonon couping theory. For the superconducting Ba4C60, the density of states at the Fermi energy was derived as 7 eV-1, while the total value of electron-phonon coupling \lambda was found to be 1.0, which is comparable to that of K3C60. The tangential Ag(2) mode, which is known as a sensitive probe for the degree of charge transfer on C60 molecule, shows a remarkable shift depending on the Ba concentration, being roughly consistent with the full charge transfer from Ba to C60. An effect of hybridization between Ba and C60 \pi orbitals is also discussed.Comment: 15 pages, 6 figures submitted to Phys. Rev. B (December 1,1998

    Zinc intake, status and indices of cognitive function in adults and children: a systematic review and meta-analysis

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    In developing countries, deficiencies of micronutrients are thought to have a major impact on child development; however, a consensus on the specific relationship between dietary zinc intake and cognitive function remains elusive. The aim of this systematic review was to examine the relationship between zinc intake, status and indices of cognitive function in children and adults. A systematic literature search was conducted using EMBASE, MEDLINE and Cochrane Library databases from inception to March 2014. Included studies were those that supplied zinc as supplements or measured dietary zinc intake. A meta-analysis of the extracted data was performed where sufficient data were available. Of all of the potentially relevant papers, 18 studies met the inclusion criteria, 12 of which were randomised controlled trials (RCTs; 11 in children and 1 in adults) and 6 were observational studies (2 in children and 4 in adults). Nine of the 18 studies reported a positive association between zinc intake or status with one or more measure of cognitive function. Meta-analysis of data from the adult’s studies was not possible because of limited number of studies. A meta-analysis of data from the six RCTs conducted in children revealed that there was no significant overall effect of zinc intake on any indices of cognitive function: intelligence, standard mean difference of <0.001 (95% confidence interval (CI) –0.12, 0.13) P=0.95; executive function, standard mean difference of 0.08 (95% CI, –0.06, 022) P=0.26; and motor skills standard mean difference of 0.11 (95% CI –0.17, 0.39) P=0.43. Heterogeneity in the study designs was a major limitation, hence only a small number (n=6) of studies could be included in the meta-analyses. Meta-analysis failed to show a significant effect of zinc supplementation on cognitive functioning in children though, taken as a whole, there were some small indicators of improvement on aspects of executive function and motor development following supplementation but high-quality RCTs are necessary to investigate this further

    Effects of self-management, education and specific exercises, delivered by health professionals, in patients with osteoarthritis of the knee

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    <p>Abstract</p> <p>Background</p> <p>An education self-management program for people with osteoarthritis (OA) of the knee was designed to be delivered by health professionals, incorporating their knowledge and expertise. Improvement in quality of life, health status and pain in response to this program has previously been demonstrated in an uncontrolled pilot study. To more rigorously test the effectiveness of the program we will undertake a randomised controlled trial of people with OA of the knee offering specific self-administered exercises and education, in accordance with the principles of self-management.</p> <p>Aim: To determine whether an education self management program for subjects with Osteoarthritis (OA) of the knee (OAK program) implemented by health professionals in a primary health care setting can achieve and maintain clinically meaningful improvements compared standard medical management in a control group.</p> <p>Methods</p> <p>The effects of standard medical management will be compared with the effects of the OAK program in a single-blind randomized study.</p> <p><it>Participants: </it>146 male and female participants with established OA knee will be recruited. Volunteers with coexistent inflammatory joint disease or serious co-morbidities will be excluded.</p> <p><it>Interventions: </it>Participants will be randomized into either intervention or control groups (delayed start). The intervention group will complete the OA knee program and both groups will be followed for 6 months.</p> <p><it>Measurements: </it>Assessments will be at baseline, 8 weeks and 6 months. SF-36, WOMAC and VAS pain questionnaires will be completed. Isometric quadriceps and hamstring strength will be measured using a dynamometer; knee range of movement using a goniometer; and physical function will be determined by a modified timed up and go test. Data will be analysed using repeated measures ANOVA.</p> <p>Discussion</p> <p>While there is evidence to support the effectiveness of SM programs for people with hypertension, diabetes and asthma, the evidence available for treatment of arthritis remains equivocal. The aim of this study is to determine the effectiveness of a disease specific self-management program for people with OA knee.</p> <p>The study design includes all the important features of a clinical experimental study to minimize bias so the results of the study will provide a high level of evidence. People with OA of the knee have identified pain and problems with daily activities as the most important problems associated with their condition. The outcome measures selected specifically address these issues and have demonstrated validity and are responsive within the range of change expected in response to the intervention. Hence the results of the study will reflect their priorities.</p> <p>The results of the study will provide evidence to guide clinicians and funding bodies seeking to establish priorities regarding the provision of this disease specific program.</p> <p>Trial registration</p> <p>ACTR number: 12607000080426</p

    Assessment of the proportion of neonates and children in low and middle income countries with access to a healthcare facility: A systematic review

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    <p>Abstract</p> <p>Background</p> <p>Comprehensive antenatal, perinatal and early postnatal care has the potential to significantly reduce the 3.58 million neonatal deaths that occur annually worldwide. This paper systematically reviews data on the proportion of neonates and children < 5 years of age that have access to health facilities in low and middle income countries. Gaps in available data by WHO region are identified, and an agenda for future research and advocacy is proposed.</p> <p>Methods</p> <p>For this paper, "utilization" was used as a proxy for "access" to a healthcare facility, and the term "facility" was used for any clinic or hospital outside of a person's home staffed by a "medical professional". A systematic literature search was conducted for published studies of children up to 5 years of age that included the neonatal age group with an illness or illness symptoms in which health facility utilization was quantified. In addition, information from available Demographic and Health Surveys (DHS) was extracted.</p> <p>Results</p> <p>The initial broad search yielded 2,239 articles, of which 14 presented relevant data. From the community-based neonatal studies conducted in the Southeast Asia region with the goal of enhancing care-seeking for neonates with sepsis, the 10-48% of sick neonates in the studies' control arms utilized a healthcare facility. Data from cross-sectional surveys involving young children indicate that 12 to 86% utilizing healthcare facilities when sick. From the DHS surveys, a global median of 58.1% of infants < 6 months were taken to a facility for symptoms of ARI.</p> <p>Conclusions</p> <p>There is a scarcity of data regarding the access to facility-based care for sick neonates/young children in many areas of the world; it was not possible to generalize an overall number of neonates or young children that utilize a healthcare facility when showing signs and symptoms of illness. The estimate ranges were broad, and there was a paucity of data from some regions. It is imperative that researchers, advocates, and policy makers join together to better understand the factors affecting health care utilization/access for newborns in different settings and what the barriers are that prevent children from being taken to a facility in a timely manner.</p

    Telehealth as a Means of Enabling Health Equity.

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    The goal of this paper is to provide a consensus review on telehealth delivery prior to and during the COVID-19 pandemic to develop a set of recommendations for designing telehealth services and tools that contribute to system resilience and equitable health.MethodsThe IMIA-Telehealth Working Group (WG) members conducted a two-step approach to understand the role of telehealth in enabling global health equity. We first conducted a consensus review on the topic followed by a modified Delphi process to respond to four questions related to the role telehealth can play in developing a resilient and equitable health system.ResultsFifteen WG members from eight countries participated in the Delphi process to share their views. The experts agreed that while telehealth services before and during COVID-19 pandemic have enhanced the delivery of and access to healthcare services, they were also concerned that global telehealth delivery has not been equal for everyone. The group came to a consensus that health system concepts including technology, financing, access to medical supplies and equipment, and governance capacity can all impact the delivery of telehealth services.ConclusionTelehealth played a significant role in delivering healthcare services during the pandemic. However, telehealth delivery has also led to unintended consequences (UICs) including inequity issues and an increase in the digital divide. Telehealth practitioners, professionals and system designers therefore need to purposely design for equity as part of achieving broader health system goals

    Scaling up community mobilisation through women's groups for maternal and neonatal health: experiences from rural Bangladesh

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    Background: Program coverage is likely to be an important determinant of the effectiveness of community interventions to reduce neonatal mortality. Rigorous examination and documentation of methods to scale-up interventions and measure coverage are scarce, however. To address this knowledge gap, this paper describes the process and measurement of scaling-up coverage of a community mobilisation intervention for maternal, child and neonatal health in rural Bangladesh and critiques this real-life experience in relation to available literature on scaling-up.Methods: Scale-up activities took place in nine unions in rural Bangladesh. Recruitment and training of those who deliver the intervention, communication and engagement with the community and other stakeholders and active dissemination of intervention activities are described. Process evaluation and population survey data are presented and used to measure coverage and the success of scale-up.Results: The intervention was scaled-up from 162 women's groups to 810, representing a five-fold increase in population coverage. The proportion of women of reproductive age and pregnant women who were engaged in the intervention increased from 9% and 3%, respectively, to 23% and 29%.Conclusions: Examination and documentation of how scaling-up was successfully initiated, led, managed and monitored in rural Bangladesh provide a deeper knowledge base and valuable lessons.Strong operational capabilities and institutional knowledge o
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