Disentangling the complex association between female genital cutting and HIV among Kenyan women

Female genital cutting (FGC) is a widespread cultural practice in Africa and the Middle East, with a number of potential adverse health consequences for women. It was hypothesised by Kun (1997) that FGC increases the risk of HIV transmission through a number of different mechanisms. Using the 2003 data from the Kenyan Demographic and Health Survey (KDHS), this study investigates the potential association between FGC and HIV. The 2003 KDHS provides a unique opportunity to link the HIV test results with a large number of demographic, social, economic and behavioural characteristics of women, including women’s FGC status. It is hypothesised that FGC increases the risk of HIV infection if HIV/AIDS is present in the community. A multilevel binary logistic regression technique is used to model the HIV status of women, controlling for selected individual characteristics of women and interaction effects. The results demonstrate evidence of a statistically significant association between FGC and HIV, after controlling for the hierarchical structure of the data, potential confounding factors, and interaction effects. The results show that women who had had FGC and a younger or the same age first union partner have higher odds of being HIV positive than women with a younger or same age first union partner but without FGC; whereas women who had had FGC and an older first union partner have lower odds of being HIV positive than women with an older first union partner but without FGC. The findings suggest the behavioural pathway of association between FGC and HIV as well as an underlying complex interplay of bio-behavioural and social variables being important in disentangling the association between FGC and HIV

The correlates of natural method use in Moldova: is natural method use associated with poverty and isolation?

Natural method use is often associated with high levels of unwanted births and induced abortions. This study investigates the correlates of natural method use in Moldova, a country with one of the highest proportions of natural contraceptive users in Europe. We hypothesize that economic and spatial disadvantage increase the reliance on natural methods whereas exposure to FP programs decreases the probability of natural method use. The analysis considers a sub-sample of 5860 sexually-active women from the 2005 Demographic and Health Survey. Results from multilevel multinomial models, controlling for relevant characteristics and data structure, show that economic disadvantage increases the probability of natural method use; but the overall effect is small. Higher FP media exposure reduces natural method use; however this effect attenuates with age. We conclude that FP efforts directed towards the poorest may have limited impact, but interventions targeted at older women could reduce the burden of unwanted pregnancies

Does early childbearing and a sterilization-focused family planning programme in India fuel population growth?

Recent stagnation in the reduction of infant mortality in India can arguably be attributed to early child bearing practices and the lack of progress in lengthening birth intervals. Meanwhile, family planning efforts have been particularly successful in the southern states such as Andhra Pradesh, although family limitation is almost exclusively by means of sterilisation at increasingly younger ages. This paper examines the population impact of the unprecedented convergence of early childbearing trajectories in India and quantifies the potential implications stemming from the neglect of strategies that encourage delaying and spacing of births. The effects of adopting a ‘later, longer and fewer’ family planning strategy are compared with the continuation of fertility concentrated in the younger age groups. Results from the cohort component population projections suggest that a policy encouraging later marriage and birth spacing would achieve a future total population which is about 52 million less in 2050 than if the current early fertility trajectory is continued.census, family planning, fertility, India, National Family Health Surveys, population policies, population projections, Sample Registration Systems, sterilisation

Global funding trends for malaria research in sub-Saharan Africa: a systematic analysis

Background Total domestic and international funding for malaria is inadequate to achieve WHO global targets in burden reduction by 2030. We describe the trends of investments in malaria-related research in sub-Saharan Africa and compare investment with national disease burden to identify areas of funding strength and potentially neglected populations. We also considered funding for malaria control. Methods Research funding data related to malaria for 1997–2013 were sourced from existing datasets, from 13 major public and philanthropic global health funders, and from funding databases. Investments (reported in US$) were considered by geographical area and compared with data on parasite prevalence and populations at risk in sub- Saharan Africa. 45 sub-Saharan African countries were ranked by amount of research funding received. Findings We found 333 research awards totalling US$814·4 million. Public health research covered $308·1 million (37·8$275·2 million (33·8%). Tanzania ($107·8 million [13·2$97·9 million [12·0%]), and Kenya ($92·9 million [11·4%]) received the highest sum of research investment and the most research awards. Malawi, Tanzania, and Uganda remained highly ranked after adjusting for national gross domestic product. Countries with a reasonably high malaria burden that received little research investment or funding for malaria control included Central African Republic (ranked 40th) and Sierra Leone (ranked 35th). Congo (Brazzaville) and Guinea had reasonably high malaria mortality, yet Congo (Brazzaville) ranked 38th and Guinea ranked 25th, thus receiving little investment. Interpretation Some countries receive reasonably large investments in malaria-related research (Tanzania, Kenya, Uganda), whereas others receive little or no investments (Sierra Leone, Central African Republic). Research investments are typically highest in countries where funding for malaria control is also high. Investment strategies should consider more equitable research and operational investments across countries to include currently neglected and susceptible populations

Diversity of Forest Litter-Inhabiting Ants Along Elevations in the Wayanad Region of the Western Ghats

Litter ant diversity and abundance in relation to biotic and abiotic factors were analyzed at five primary forest sites lying between 300 to 1650 meter above mean sea level in the Wayanad region of the Western Ghats in Kerala, southern India. Ant abundance and species richness peaked at mid-elevations influenced by the presence of favourable physical conditions and abundance of prey resources. Dominance of ants preferring termites and Collembola as prey at sites rich in their specific prey resources indicate the influence of local prey resource availability in determining ant distribution. Dominant species (Tapinoma sp. and Solenopsis sp.) had wider distributions, being present at all elevations. Physical factors (slope of the terrain, rainfall, moisture, humidity, temperature) and prey resource availability (insect larvae, termites, Collembola) influenced ant species abundance at a regional scale, whereas at local scales, site specific variations in the relationship between abundance of ants and prey-predators and physical factors were recorded. The present study highlights the need to consider site-specific abiotic and biotic factors while examining the distribution patterns of litter ants along altitudinal gradients in other regions of the Western Ghats, which is a recognised hot spot of biodiversity with wide regional variation in vegetation types and faunal distribution patterns

Stress relaxation behavior of organically modified montmorillonite filled natural rubber/nitrile rubber nanocomposites

International audienceTo reduce material consumption, it is important to have reinforced material with longer life time. Incorporation of nanoparticles to reinforce and compatibilize polymer blends is one of the widely undergoing research areas in polymer science technology. A series of natural rubber and nitrile rubber (NR/NBR) nanocomposite vulcanazite, reinforced with two different organically modified clay (OMt) were prepared. To predict the performance of a material over long periods of time, stress relaxation studies with both the reinforced systems were done. The effects of loading, blend composition, filler polarity and temperature on stress relaxation of OMt reinforced NR/NBR nanocomposites were carefully measured. Based on the stress relaxation measurements, it was observed that due to its polarity difference, O1Mt (Mt modified with dimethyl, benzyl, HT modification provided by Southern Clay Products) was preferentially located at the NBR phase while O2Mt (Mt modified with mercapto silane provided by English India Clay) had more affinity with natural rubber in the NR/NBR nanocomposites. The preferential localization of OMt has been analyzed by HRTEM. The nature of interaction of the nanoclay was found to influence the stress relaxation rate. NR/NBR nanocomposites with higher filler loading showed higher rates of relaxation rate due to the presence of more filler-filler interactions. At 70 degrees C, the viscosity ratio was found to influence the reinforcement, and consequently relaxation rate of the 50/50 NR/NBR nanocomposites. It was found that the rearrangements of the polymer chains are dependent on the blend composition, temperature, filler/polymer interactions etc. To explain and predict observed phenomena, the stretched-exponential Kohlrausch equation and Maxwell-Weichert model were used. For both models, the experimental curve fitted well with the theoretical models. (C) 2013 Elsevier B.V. All tights reserved

Tight Junction Protein Claudin-7 Is Essential for Intestinal Epithelial Stem Cell Self-Renewal and Differentiation

Background & Aims: Claudin-7 (Cldn7) is a tight junction (TJ) membrane protein located at the apical TJ and basolateral side of intestinal epithelial cells. Deletion of Cldn7 by gene targeting leads to the inflammatory bowel disease–like phenotype in mice, which includes weight loss, diarrhea, mucosa ulceration, and severe intestinal epithelial damage. In this study, we test our hypothesis that Cldn7 plays a critical role in regulating intestinal crypt stem cell functions. Methods: Gene expression microarray, quantitative reverse-transcription polymerase chain reaction, in situ hybridization, histologic examinations, immunoblotting, 3-dimensional organoid culture, and various treatments to rescue Cldn7-deficient organoid defects were conducted using global Cldn7 knockout mice and inducible, conditional Cldn7 knockout mice. Results: Gene deletion of Cldn7 in intestines showed significant alteration of expression profiles with striking down-regulation of intestinal crypt stem cell markers such as Olfm4, dislocated proliferative cells, and disrupted epithelial cell differentiation. In addition, the isolated Cldn7-deficient crypts where the stem cells reside were either unable to survive at all or formed defective spheroids, highlighting the functional impairment of crypt stem cells in the absence of Cldn7. Remarkably, the Cldn7-expressing organoids with buddings underwent rapid cell degeneration within days after turning off Cldn7 expression in the culture. We identified that activation of Wnt/β-catenin signaling rescued the organoid defects caused by Cldn7 deletion. Conclusions: In this study, we show that Cldn7 is indispensable in controlling Wnt/β-catenin signaling–dependent intestinal epithelial stem cell survival, self-renewal, and cell differentiation. This study could open a door to study roles of TJ proteins in stem cell regulations in other tissues and organs

Two-dimensional 1H and 1H-detected NMR study of a heterogeneous biocatalyst using fast MAS at high magnetic fields

Abstract Nuclear magnetic resonance (NMR) is a powerful tool for investigating atomic-scale structure in heterogeneous or composite materials where long-range order is absent. In this work solid-state 1H and 1H-detected NMR experiments were performed with fast magic angle spinning (νR = 75 kHz) and at high magnetic fields (B0 = 20 T) and used to gain structural insight into a heterogeneous biocatalyst consisting of an enzyme, human carbonic anhydrase II (hCA II), covalently immobilized on epoxy-functionalized silica. Two-dimensional 1H-1H NOESY-type correlation experiments were able to provide information on 1H environments in silica, epoxy-silica and the immobilized enzyme. Two distinct signals originating from water protons were observed: water associated with the surface of the silica and the water associated with the immobilized enzyme. Additional two-dimensional 1H-1H double–single quantum (DQ-SQ) correlation experiments suggested that the immobilized enzyme is not in close contact with the silica surface. Most significantly, comparison of two-dimensional 1H-15N spectra of the immobilized enzyme and the solution-state enzyme confirmed that the structural integrity of the protein is well preserved upon covalent immobilization

High-resolution structural characterization of a heterogeneous biocatalyst using solid-state NMR

Solid-state magic-angle spinning (MAS) NMR spectroscopy was employed to investigate structural detail in an enzyme, hu- man carbonic anhydrase II (hCA II) in uniformly 15N and selectively (15N leucine) enriched states, covalently immobilized on epoxy- functionalized silica. The immobilized hCA II retained 71% of its specific enzymatic activity when compared to the free enzyme in solution. Based on the one- and two-dimensional 1H, 13C, 15N and 29Si MAS NMR spectra, chemical shift assignments could be obtained from the silica support, covalent linker and the immobilized enzyme. The successful covalent immobilization of the enzyme on epoxy-silica was confirmed by the appearance of signals from the aromatic and carbonyl groups in the immobilized enzyme in addition to signals from the modified sup- port. Most notably, our MAS NMR results suggest that the covalent immobilization of the hCA II on epoxy-silica does not significantly affect the structural integrity of the protein