The Effect of the Environment on alpha-Al_2O_3 (0001) Surface Structures

We report that calculating the Gibbs free energy of the alpha-Al_2O_3 (0001) surfaces in equilibrium with a realistic environment containing both oxygen and hydrogen species is essential for obtaining theoretical predictions consistent with experimental observations. Using density-functional theory we find that even under conditions of high oxygen partial pressure, the metal terminated surface is surprisingly stable. An oxygen terminated alpha-Al_2O_3 (0001) surface becomes stable only if hydrogen is present on the surface. In addition, including hydrogen on the surface resolves discrepancies between previous theoretical work and experimental results with respect to the magnitude and direction of surface relaxations.Comment: 4 pages including 2 figures. Submitted to Phys. Rev. Lett. Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Women living with HIV, diabetes and/or hypertension multi-morbidity in Uganda: a qualitative exploration of experiences accessing an integrated care service

Purpose: Women experience a triple burden of ill-health spanning non-communicable diseases (NCDs), reproductive and maternal health conditions and human immunodeficiency virus (HIV) in sub-Saharan Africa. Whilst there is research on integrated service experiences of women living with HIV (WLHIV) and cancer, little is known regarding those of WLHIV, diabetes and/or hypertension when accessing integrated care. Our research responds to this gap. Design/methodology/approach: The INTE-AFRICA project conducted a pragmatic parallel arm cluster randomised trial to scale up and evaluate “one-stop” integrated care clinics for HIV-infection, diabetes and hypertension at selected primary care centres in Uganda. A qualitative process evaluation explored and documented patient experiences of integrated care for HIV, diabetes and/or hypertension. In-depth interviews were conducted using a phenomenological approach with six WLHIV with diabetes and/or hypertension accessing a “one stop” clinic. Thematic analysis of narratives revealed five themes: lay health knowledge and alternative medicine, community stigma, experiences of integrated care, navigating personal challenges and health service constraints. Findings: WLHIV described patient pathways navigating HIV and diabetes/hypertension, with caregiving responsibilities, poverty, travel time and cost and personal ill health impacting on their ability to adhere to multi-morbid integrated treatment. Health service barriers to optimal integrated care included unreliable drug supply for diabetes/hypertension and HIV linked stigma. Comprehensive integrated care is recommended to further consider gender sensitive aspects of care. Originality/value: This study whilst small scale, provides a unique insight into the lived experience of WLHIV navigating care for HIV and diabetes and/or hypertension, and how a “one stop” integrated care clinic can support them (and their children) in their treatment journeys

Management\u27s Perspective on Critical Success Factors Affecting Mobile Learning in Higher Education Institutions - An Empirical Study

Mobile learning (m-Learning) is considered to be one of the fastest growing learning platforms. The immense interest in m-Learning is attributed to the incredible rate of growth of mobile technology and its proliferation into every aspect of modern life. Despite this, m-Learning has not experienced a similar adoption rate in the education sector, chiefly higher education. Researchers have attempted to explain this anomaly by conducting several studies in the area. However, mostly the research in m-Learning is examined from the perspective of the students and educators. In this research, it is contended that there is a third important stakeholder group whose opinion is equally important in determining the success of m-Learning: the university management. Although diversified by nature, heads of departments, deans, and information technology system administrators are nevertheless considered members of any university management. The results of the research show that university commitment to m-Learning, university learning practices, and change management practices were the factors critical to the success of m-Learning, from the university management perspective

Women living with HIV, diabetes and/or hypertension multimorbidity in Uganda: A qualitative exploration of experiences accessing a ‘one stop’ integrated care service.

Purpose: Women experience a triple burden of ill-health spanning non-communicable diseases (NCDs), reproductive and maternal health conditions and human immunodeficiency virus (HIV) in sub-Saharan Africa.. Whilst there is research on integrated service experiences of women living with HIV (WLHIV) and cancer, little is known regarding those of WLHIV, diabetes and/or hypertension when accessing integrated care. Design: The INTE-AFRICA project conducted a pragmatic parallel arm cluster randomised trial to scale up and evaluate ‘one-stop’ integrated care clinics for HIV-infection, diabetes and hypertension at selected primary care centres in Uganda. A qualitative process evaluation explored and documented patient experiences of integrated care for HIV, diabetes and/or hypertension. In-depth interviews were conducted using a phenomenological approach with six WLHIV with diabetes and/or hypertension accessing a ‘one stop’ clinic. Thematic analysis of narratives revealed five themes: lay health knowledge and alternative medicine; community stigma; experiences of integrated care; navigating personal challenges and health service constraints. Findings: WLHIV described patient pathways navigating HIV and diabetes/hypertension, with caregiving responsibilities, poverty, travel time and cost and personal ill health impacting on their ability to adhere to multi-morbid integrated treatment. Health service barriers to optimal integrated care included unreliable drug supply for diabetes/hypertension and HIV linked stigma. Comprehensive integrated care is recommended to further consider gender sensitive aspects of care. Originality: This study whilst small scale, provides a unique insight into the lived experience of WLHIV navigating care for HIV and diabetes and/or hypertension, and how a ‘one stop’ integrated care clinic can support them (and their children) in their treatment journeys

Pharmacy Participation in Non-Prescription Syringe Sales in Los Angeles and San Francisco Counties, 2007

Increasing sterile syringe access for injection drug users (IDUs) is one way to prevent HIV and hepatitis C virus (HCV) transmission in this population. In 2005, California Senate Bill 1159 allowed counties to adopt the Disease Prevention Demonstration Project (DPDP). Where enacted, the DPDP allows pharmacies that register with the county to sell up to ten syringes to adults without a prescription. In the current study, we describe pharmacy participation in nonprescription syringe sales (NPSS) in two counties in California and examine factors associated with NPSS. Telephone and in-person interviews were conducted in Los Angeles (LA) and San Francisco (SF) with 238 pharmacies in 2007 (n = 67 in SF; n = 171 in LA). Quantitative survey items captured pharmacy registration with the county, pharmacy policies/practices, episodes and conditions of NPSS and refusals to sell, potential negative consequences of NPSS, and staff attitudes regarding HIV and HCV prevention for IDUs. Overall, 42% of pharmacies reported NPSS (28% in LA and 81% in SF), although only 34% had registered with the county (17% in LA and 76% in SF). Many pharmacies required proof of a medical condition (80% in LA and 30% in SF) and refused NPSS if the customer was a suspected IDU (74% in LA, 33% in SF). Few negative consequences of NPSS were reported. In multivariate logistic regression analysis, we found that the odds of NPSS were significantly higher among pharmacists who thought syringe access was important for preventing HIV among IDUs [adjusted odds ratio (AOR) = 2.95; 95% confidence interval (CI) = 1.10–7.92], were chain pharmacies (AOR = 12.5; 95% CI = 4.55–33.33), and were located in SF (AOR = 4.88; 95% CI = 1.94–12.28). These results suggest that NPSS were influenced by pharmacists’ perception. NPSS might be increased through greater educational efforts directed at pharmacists, particularly those in non-chain pharmacies

Cryptococcus neoformans Capsular Enlargement and Cellular Gigantism during Galleria mellonella Infection

We have studied infection of Cryptococcus neoformans in the non-vertebrate host Galleria mellonella with particular interest in the morphological response of the yeast. Inoculation of C. neoformans in caterpillars induced a capsule-independent increase in haemocyte density 2 h after infection. C. neoformans manifested a significant increase in capsule size after inoculation into the caterpillar. The magnitude of capsule increase depended on the temperature, being more pronounced at 37°C than at 30°C, which correlated with an increased virulence of the fungus and reduced phagocytosis at 37°C. Capsule enlargement impaired phagocytosis by haemocytes. Incubation of the yeast in G. mellonella extracts also resulted in capsule enlargement, with the polar lipidic fraction having a prominent role in this effect. During infection, the capsule decreased in permeability. A low proportion of the cells (<5%) recovered from caterpillars measured more than 30 µm and were considered giant cells. Giant cells recovered from mice were able to kill the caterpillars in a manner similar to regular cells obtained from in vivo or grown in vitro, establishing their capacity to cause disease. Our results indicate that the morphological transitions exhibited by C. neoformans in mammals also occur in a non-vertebrate host system. The similarities in morphological transitions observed in different animal hosts and in their triggers are consistent with the hypothesis that the cell body and capsular responses represent an adaptation of environmental survival strategies to pathogenesis

Mitochondrial phylogeography and population structure of the cattle tick Rhipicephalus appendiculatus in the African Great Lakes region

Abstract Background The ixodid tick Rhipicephalus appendiculatus is the main vector of Theileria parva, wich causes the highly fatal cattle disease East Coast fever (ECF) in sub-Saharan Africa. Rhipicephalus appendiculatus populations differ in their ecology, diapause behaviour and vector competence. Thus, their expansion in new areas may change the genetic structure and consequently affect the vector-pathogen system and disease outcomes. In this study we investigated the genetic distribution of R. appendiculatus across agro-ecological zones (AEZs) in the African Great Lakes region to better understand the epidemiology of ECF and elucidate R. appendiculatus evolutionary history and biogeographical colonization in Africa. Methods Sequencing was performed on two mitochondrial genes (cox1 and 12S rRNA) of 218 ticks collected from cattle across six AEZs along an altitudinal gradient in the Democratic Republic of Congo, Rwanda, Burundi and Tanzania. Phylogenetic relationships between tick populations were determined and evolutionary population dynamics models were assessed by mismach distribution. Results Population genetic analysis yielded 22 cox1 and 9 12S haplotypes in a total of 209 and 126 nucleotide sequences, respectively. Phylogenetic algorithms grouped these haplotypes for both genes into two major clades (lineages A and B). We observed significant genetic variation segregating the two lineages and low structure among populations with high degree of migration. The observed high gene flow indicates population admixture between AEZs. However, reduced number of migrants was observed between lowlands and highlands. Mismatch analysis detected a signature of rapid demographic and range expansion of lineage A. The star-like pattern of isolated and published haplotypes indicates that the two lineages evolve independently and have been subjected to expansion across Africa. Conclusions Two sympatric R. appendiculatus lineages occur in the Great Lakes region. Lineage A, the most diverse and ubiquitous, has experienced rapid population growth and range expansion in all AEZs probably through cattle movement, whereas lineage B, the less abundant, has probably established a founder population from recent colonization events and its occurrence decreases with altitude. These two lineages are sympatric in central and eastern Africa and allopatric in southern Africa. The observed colonization pattern may strongly affect the transmission system and may explain ECF endemic instability in the tick distribution fringes

Development of an In Vitro Model for the Multi-Parametric Quantification of the Cellular Interactions between Candida Yeasts and Phagocytes

We developed a new in vitro model for a multi-parameter characterization of the time course interaction of Candida fungal cells with J774 murine macrophages and human neutrophils, based on the use of combined microscopy, fluorometry, flow cytometry and viability assays. Using fluorochromes specific to phagocytes and yeasts, we could accurately quantify various parameters simultaneously in a single infection experiment: at the individual cell level, we measured the association of phagocytes to fungal cells and phagocyte survival, and monitored in parallel the overall phagocytosis process by measuring the part of ingested fungal cells among the total fungal biomass that changed over time. Candida albicans, C. glabrata, and C. lusitaniae were used as a proof of concept: they exhibited species-specific differences in their association rate with phagocytes. The fungal biomass uptaken by the phagocytes differed significantly according to the Candida species. The measure of the survival of fungal and immune cells during the interaction showed that C. albicans was the more aggressive yeast in vitro, destroying the vast majority of the phagocytes within five hours. All three species of Candida were able to survive and to escape macrophage phagocytosis either by the intraphagocytic yeast-to-hyphae transition (C. albicans) and the fungal cell multiplication until phagocytes burst (C. glabrata, C. lusitaniae), or by the avoidance of phagocytosis (C. lusitaniae). We demonstrated that our model was sensitive enough to quantify small variations of the parameters of the interaction. The method has been conceived to be amenable to the high-throughput screening of mutants in order to unravel the molecular mechanisms involved in the interaction between yeasts and host phagocytes

The structure and features of the SMS language used in the written work of Communication English I students at a university in South Africa

Employing an explanatory design, this study set out to investigate the morphosyntactic structures of the SMS language of Communication English I students, and the types of SMS language features used in their written work at a university of technology in South Africa. The study randomly sampled 90 undergraduate students (M = 40; F = 50) enrolled for a national diploma programme during the first academic semester in 2013. Their ages ranged from 19–22 years; they all spoke English as a second language, whilst having one of the five black South African languages as their home language. The study had two types of data: participants’ mobile phone text messages (in two sets), and their writing samples. Two of the findings of the study are: the morphological structure of the textisms used in the participants’ text messages deviated from that applicable to formal, standard English, whereas much of their syntactic structure did not; and, the frequency and proportion of textisms in participants’ writing samples were lower than that reported in studies by Freudenberg (2009) and Rosen et al. (2010)