The Thermal Agitated Phase Transitions on the Ti32 Nanocluster: a Molecular Dynamics Simulation Study

Molecular dynamics simulations were performed to investigate the stability with respect to increasing the simulated temperature from 300 to 2400 K of an isolated cluster composed of 32 titanium atoms. The interatomic interactions were modelled using Gupta potentials as implemented within the classical molecular dynamics simulation software DL_POLY. The radial distribution functions (RDF), diffusion coefficient, and density profiles were examined to study the structural changes as a function of temperature. It was found that the Ti32 nanocluster exhibits temperature structural transition. The icosahedron and pentagonal bi-pyramid structures were found to be the most dominant building block fragments. Deformation of the nanocluster was also measured by diffusion coefficient, and it was found that the Ti32 are mobile above the bulk melting point. The phase transitions from solid to liquid have been identified by a simple jump in the total energy curve, with the predicted melting temperature near the bulk melting point (1941.15 K). As expected, the RDF’s and density profile peaks decrease with increasing temperature

Women’s perspectives on the measures that need to be taken to increase the use of health-care facility delivery service among slums women, Addis Ababa, Ethiopia: a qualitative study

Abstract Background Global strategies to target high maternal mortality ratios are focused on providing skilled attendance at delivery along with access to emergency obstetric care. Research that examines strategies to increase facility-based skilled birth attendance among slum residents in Addis Ababa, Ethiopia, is limited. Objective The study aimed to explore women's perspectives on the measures that need to be taken to increase the use of the facility—delivery service among slums women, Addis Ababa, Ethiopia Methods Qualitative exploratory and descriptive research designs were used. Participants in the study were women in the reproductive age group (18–49 years of age) living in the slum areas of Addis Ababa, Ethiopia. A purposive sampling strategy was used to select study participants. Potential participants' names were gathered from health facilities and followed to their homes for the study. Four audio-recorded focus group discussions [FGDs] were conducted with 32 participants from the three public health centers and one district hospital. The number of participants in FGDs was between 6 and 10 women. Data were analyzed simultaneously with data collection. Thematic analysis was used in data analysis, which entails three interconnected stages: data reduction, data display, and data conclusion. In addition, thematic analysis entailed evaluating the structure and content of textual data, identifying data themes, coding the themes, and then interpreting the structure and content of the themes. A codebook was first devised, discussed, and adopted by the writers before they could use this technique. Using the codebook, the theme codes were then manually produced. To explain the study results, verbatim excerpts from participants were given. The researcher used Techs' eight steps of qualitative data analysis method for analyzing the data. A multi-level life-course framework of facility-based delivery in low- and middle-income countries (LMICs) developed by Bohren et al. was used to frame the current study and link the findings of the study to the body of knowledge. Results The FGDs included a total of 32 participants. The mean age of the overall sample was 32.6 years (± SD = 5.2). Participants' educational characteristics indicate that the majority (24 out of 32) was found to have no formal education, and two-thirds of participants were found to have one to five children. Three-fourths of them attended the ANC twice and they all gave birth to their last child at home. Two themes emerged from the analysis of focus group data, namely provision of quality, respectful and dignified midwifery care, and lack of awareness about facility delivery. These themes were described as a rich and comprehensive account of the views and suggestions made by focused antenatal care [FANC] participants on measures required to improve the use of the facility-delivery services. The findings of the study raise concerns about the effectiveness of FANC in encouraging facility-deliveries since FANC participants had not used health facilities for their last childbirth. According to the findings of the focus groups, women who took part in this study identified measures required to increase the use of health facility-delivery services among FANC participants in Addis Ababa's slum residents. It is to be expected that diligent counseling during antenatal care about birth plans would facilitate prompt arrival at facilities consistent with the desires of women.Plain language summary Global strategies for targeting high maternal mortality levels are based on ensuring eligible delivery attendance along with access to obstetric emergency care. Research examining strategies to increase facility-based skilled birth attendance among slum residents in Addis Ababa, Ethiopia, is minimal. The study aimed to examine women's perspectives on measures needed to improve the use of health facility-based delivery services. A qualitative research design, both exploratory and descriptive, was used. Women in the reproductive age group (18–49 years of age) living in the slum areas of Addis Ababa, Ethiopia, participated in the study. The study used a purposeful sampling method. Four audio-recorded focus group discussions [FGDs] were conducted with 32 participants. In FGDs, the number of participants was between 6 and 10 women. Data were analyzed in conjunction with data collection. For the research, thematic analysis was performed. Two issues arose from the review of data from focus group interviews, namely quality care provision, respectful and dignified midwifery care, and lack of awareness about facility delivery. These themes were identified as a detailed and comprehensive account of the views and suggestions of focused antenatal care [FANC] participants on steps needed to enhance the use of health facility-based delivery services. According to the results of the focus groups, among FANC participants in the slum residents of Addis Ababa, women who took part in this study identified steps needed to increase the use of health facility-based delivery services. It is to be expected that diligent counseling during antenatal care about birth plans would facilitate prompt arrival at facilities consistent with the desires of women

Thermodynamically accessible titanium clusters TiN, N = 2–32

We have performed a genetic algorithm search on the tight-binding interatomic potential energy surface (PES) for small TiN (N = 2–32) clusters. The low energy candidate clusters were further refined using density functional theory (DFT) calculations with the PBEsol exchange–correlation functional and evaluated with the PBEsol0 hybrid functional. The resulting clusters were analysed in terms of their structural features, growth mechanism and surface area. The results suggest a growth mechanism that is based on forming coordination centres by interpenetrating icosahedra, icositetrahedra and Frank–Kasper polyhedra. We identify centres of coordination, which act as centres of bulk nucleation in medium sized clusters and determine the morphological features of the cluster

The thermal agitated phase transitions on the Ti32 nanocluster: a molecular dynamics simulation study

Molecular dynamics simulations were performed to investigate the stability with respect to increasing the simulated temperature from 300 to 2400 K of an isolated cluster composed of 32 titanium atoms. The interatomic interactions were modelled using Gupta potentials as implemented within the classical molecular dynamics simulation software DL_POLY. The radial distribution functions (RDF), diffusion coefficient, and density profiles were examined to study the structural changes as a function of temperature. It was found that the Ti32 nanocluster exhibits temperature structural transition. The icosahedron and pentagonal bi-pyramid structures were found to be the most dominant building block fragments. Deformation of the nanocluster was also measured by diffusion coefficient, and it was found that the Ti32 are mobile above the bulk melting point. The phase transitions from solid to liquid have been identified by a simple jump in the total energy curve, with the predicted melting temperature near the bulk melting point (1941.15 K). As expected, the RDF's and density profile peaks decrease with increasing temperatur

THE VLT LEGA-C spectroscopic survey:the physics of galaxies at a lookback time of 7 Gyr

The Large Early Galaxy Census (LEGA-C) is a Public Spectroscopic Survey of ~3200 K-band selected galaxies at redshifts z = 0.6 − 1.0 with stellar masses ${M}_{*}\gt {10}^{10}\quad {M}_{\odot }$, conducted with VIMOS on ESO's Very Large Telescope. The survey is embedded in the COSMOS field (R.A. = 10h00; $\mathrm{decl}.\;=\;+2\;\mathrm{deg}$). The 20 hr long integrations produce high-signal-to-noise ratio continuum spectra that reveal ages, metallicities and velocity dispersions of the stellar populations. LEGA-C's unique combination of sample size and depth will enable us for the first time to map the stellar content at large lookback time, across galaxies of different types and star formation activity. Observations started in 2014 December and are planned to be completed by mid 2018, with early data releases of the spectra and value-added products. In this paper we present the science case, the observing strategy, an overview of the data reduction process and data products, and a first look at the relationship between galaxy structure and spectral properties, as it existed 7 Gyr ago

An evaluation of classification systems for stillbirth

<p>Abstract</p> <p>Background</p> <p>Audit and classification of stillbirths is an essential part of clinical practice and a crucial step towards stillbirth prevention. Due to the limitations of the ICD system and lack of an international approach to an acceptable solution, numerous disparate classification systems have emerged. We assessed the performance of six contemporary systems to inform the development of an internationally accepted approach.</p> <p>Methods</p> <p>We evaluated the following systems: Amended Aberdeen, Extended Wigglesworth; PSANZ-PDC, ReCoDe, Tulip and CODAC. Nine teams from 7 countries applied the classification systems to cohorts of stillbirths from their regions using 857 stillbirth cases. The main outcome measures were: the ability to retain the important information about the death using the <it>InfoKeep </it>rating; the ease of use according to the <it>Ease </it>rating (both measures used a five-point scale with a score <2 considered unsatisfactory); inter-observer agreement and the proportion of unexplained stillbirths. A randomly selected subset of 100 stillbirths was used to assess inter-observer agreement.</p> <p>Results</p> <p><it>InfoKeep </it>scores were significantly different across the classifications (<it>p </it>≤ 0.01) due to low scores for Wigglesworth and Aberdeen. CODAC received the highest mean (SD) score of 3.40 (0.73) followed by PSANZ-PDC, ReCoDe and Tulip [2.77 (1.00), 2.36 (1.21), 1.92 (1.24) respectively]. Wigglesworth and Aberdeen resulted in a high proportion of unexplained stillbirths and CODAC and Tulip the lowest. While <it>Ease </it>scores were different (<it>p </it>≤ 0.01), all systems received satisfactory scores; CODAC received the highest score. Aberdeen and Wigglesworth showed poor agreement with kappas of 0.35 and 0.25 respectively. Tulip performed best with a kappa of 0.74. The remainder had good to fair agreement.</p> <p>Conclusion</p> <p>The Extended Wigglesworth and Amended Aberdeen systems cannot be recommended for classification of stillbirths. Overall, CODAC performed best with PSANZ-PDC and ReCoDe performing well. Tulip was shown to have the best agreement and a low proportion of unexplained stillbirths. The virtues of these systems need to be considered in the development of an international solution to classification of stillbirths. Further studies are required on the performance of classification systems in the context of developing countries. Suboptimal agreement highlights the importance of instituting measures to ensure consistency for any classification system.</p

Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.

BACKGROUND: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. METHODS: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. FINDINGS: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. INTERPRETATION: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. FUNDING: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.The SHINE trial is funded by the Bill & Melinda Gates Foundation (OPP1021542 and OPP113707); UK Department for International Development; Wellcome Trust, UK (093768/Z/10/Z, 108065/Z/15/Z and 203905/Z/16/Z); Swiss Agency for Development and Cooperation; US National Institutes of Health (2R01HD060338-06); and UNICEF (PCA-2017-0002)

Alcohol use amongst learners in rural high school in South Africa

Background: Drinking behaviour by adolescents is a significant public health challenge nationally and internationally. Alcohol use has serious challenges that continue to deprive adolescents of their normal child growth and development. Drinking is associated with dangers that include fighting, crime, unintentional accidents, unprotected sex, violence and others. Aim: The aim of the study is to investigate drinking patterns, and factors contributing to drinking, amongst secondary school learners in South Africa. Method: The sample included 177 male (46.6%) and 206 female (53.4%) respondents in the age range from 15–23 years, selected by stratified random sampling. Results: The results indicated that 35.5% of male and 29.7% of female respondents used alcohol. Both male and female respondents consumed six or more alcohol units (binge drinking) within 30 days; on one occasion the consumption was 17.5% and 15.9% respectively. It was found that alcohol consumption increases with age, 32.2% of 15–17 year-olds and 53.2% of 18–20 year-olds consumed different types of alcohol. It was deduced that 28.9% respondents reported that one of the adults at home drank alcohol regularly, and 9.3% reported that both their parents drank alcohol daily. It was found that 27.6% of the respondents agreed that friends made them conform to drinking. The tenth and eleventh grade reported 15.2% of male and 13.9% of female respondents were aware that alcohol can be addictive. Conclusion: This study found that age, gender, parental alcohol use and peer pressure were found to be the major contributing factors to alcohol use amongst learners Prevention campaigns such as introducing the harmful effects of alcohol use amongst learners are of utmost importance in reducing alcohol use amongst learners in South Africa

Engineering of Ti

Bimetallic transition metal nanoclusters have attracted significant attention in recent years due to their wide range of applications such as heterogeneous catalysts, electrochemistry and alloy design. However many studies were reported on pure transition metal nanoclusters and bimetallic of late transition metal nanoclusters. In this study the density functional theory (DFT) with PBEsol exchange correlation functional was employed to investigate the structural and electronic properties of TiN-1Os (N = 2-16) nanoclusters. The calculations showed that osmium impurity mostly prefers to be encapsulated by titanium nanoclusters. The binding energies gradually decrease with the cluster size N. The Os dopant was found to enhance the binding energy of titanium nanoclusters. The relative stability or second order energies showed that Ti6Os and Ti12Os clusters are the most stable. Interestingly, osmium dopant converted the nanocluster with 13 atoms to be the most stable. Furthermore, the dissociation energy or first order energies showed an excellent correlation with the relative stability trend. The HOMO-LUMO revealed the lowest energy gap at Ti12Os (N = 13) which correlates well with the predicted binding energy, relative stability and dissociation energy

A situational analysis of child-headed households in South Africa

The aftermath of the HIV and AIDS pandemic has resulted in great suffering in terms of loss of income, poor quality of life, morbidity and mortality, with children being destitute and orphaned at an alarming rapid rate. Families and communities are currently unable to cope with the effects of HIV and AIDS with special emphasis on the care and support of the affected orphans and vulnerable children, who as a result have been compelled to look after themselves giving rise to a new type of family, the child-headed household. The emergence of this type of family requires government’s response in terms of care and support. The purpose of this study was to provide a broad picture of the location, prevalence, composition, functions, needs and challenges of child-headed households in South Africa, and explore available and required services, resources and safety nets for children in child-headed households. An exploratory and descriptive design was used for the purpose. The sample consisted of children heading households and those living in the households that are headed by children; government departments responsible for child welfare, such as, the Departments of Social Development, Health, Education and Agriculture; non-profit organisations and communities where these households are predominant. From the data collected, it was found that the rights of the affected children were compromised. Those heading the households were often not at school and were responsible for domestic chores. The households needed food, clothes, money, shelter, and education. Government in attempting to address these needs required clear policies which will provide a distinction between orphaned and vulnerable children and child-headed households.The study recommended a collaborative approach as it was shown that there was no single model of best practice to appropriately and effectively address the needs of child-headed households