Revisiting the Mechanism of the Meso-to-α Transition of Isotactic Polypropylene and Ethylene-Propylene Random Copolymers

In this work, we have conducted in situ simultaneous small- and wide-angle X-ray scattering and Raman spectroscopy experiments to investigate the fundamental differences in the mechanism of the mesomorphic to α phase transition of the isotactic polypropylene homopolymer and the random ethylene-propylene copolymer. Via quantitative analysis of the results coming from the three techniques, we found that in the homopolymer, chain interlock and chain extension occur during the transition. However, these processes are not necessary for the transition to occur. Indeed, the presence of randomly distributed ethylene co-units hinders the chain interlock process in the early stages of the phase transition (T > 60 °C) and suppresses the chain elongation process at the later stages (T > 90 °C). Consequently, the mesomorphic to α-phase transition in the random copolymer occurs with inclusion of the ethylene co-units inside the crystal lattice, causing increased lateral interchain distance and larger crystalline sizes. Our results show how differences exist in the way solid phase transitions occur at the molecular scale when co-monomers are included into the macromolecular chains, leading to a better understanding of the thermal behavior of semi-crystalline polymers

Data Mining of Polymer Phase Transitions upon Temperature Changes by Small and Wide-Angle X-ray Scattering Combined with Raman Spectroscopy

The complex physical transformations of polymers upon external thermodynamic changes are related to the molecular length of the polymer and its associated multifaceted energetic balance. The understanding of subtle transitions or multistep phase transformation requires real-time phenomenological studies using a multi-technique approach that covers several length-scales and chemical states. A combination of X-ray scattering techniques with Raman spectroscopy and Differential Scanning Calorimetry was conducted to correlate the structural changes from the conformational chain to the polymer crystal and mesoscale organization. Current research applications and the experimental combination of Raman spectroscopy with simultaneous SAXS/WAXS measurements coupled to a DSC is discussed. In particular, we show that in order to obtain the maximum benefit from simultaneously obtained high-quality data sets from different techniques, one should look beyond traditional analysis techniques and instead apply multivariate analysis. Data mining strategies can be applied to develop methods to control polymer processing in an industrial context. Crystallization studies of a PVDF blend with a fluoroelastomer, known to feature complex phase transitions, were used to validate the combined approach and further analyzed by MVA

Food Insecurity and Intimate Partner Violence in Mwanza, Tanzania: A Longitudinal Analysis

Introduction: Food insecurity is a potential predictor of intimate partner violence. This study (1) describes the prevalence of food insecurity and various forms of intimate partner violence experience among women in Mwanza, Tanzania; and (2) assesses the effect of food insecurity and hunger on various forms of women's experience of intimate partner violence longitudinally. Methods: Women (aged 18–70 years) who reported being in a relationship in the past 12 months, who had participated in the control arms of two randomized controlled trials conducted as part of the MAISHA study were interviewed at four time points (N=1,004 at baseline in 2017). Analyses were conducted in 2022. Associations between food insecurity exposures and intimate partner violence outcomes were assessed, and univariate random effect logistic models were conducted to identify relevant sociodemographic variables (including age, education level, and SES) that were statistically significant. Multivariable random effects logistic models were conducted, including time as a fixed effect, to calculate odds ratios indicating associations between food insecurity exposures and intimate partner violence outcomes. Results: Prevalence of food insecurity was 47.7%, 55.6%, 47.2%, and 50.8% for each of the 4 waves, respectively, with significant difference in proportion of food insecurity between baseline and Wave 2. Multivariable random effects models indicated that food insecurity was associated with increased odds of exposure to all forms of intimate partner violence outcomes, and hunger was significantly associated with increased odds of experience of all intimate partner violence outcomes, apart from controlling behaviors. Conclusions: Results from this longitudinal analysis of food insecurity and women's reports of intimate partner violence experience in a low- and middle-income country setting indicate that food insecurity is significantly associated with all forms of intimate partner violence, apart from controlling behaviors, among women in this sample in Mwanza, Tanzania. Policy and programmatic implications include the need for integrated intimate partner violence prevention programming to take into account household food needs

Understanding mobility and sexual risk behaviour among women in fishing communities of Lake Victoria in East Africa: a qualitative study.

BACKGROUND: HIV-prevalence and incidence is high in many fishing communities around Lake Victoria in East Africa. In these settings, mobility among women is high and may contribute to increased risk of HIV infection and poor access to effective prevention and treatment services. Understanding the nature and patterns of this mobility is important for the design of interventions. We conducted an exploratory study to understand the nature and patterns of women's mobility to inform the design of HIV intervention trials in fishing communities of Lake Victoria. METHODS: This was a cross-sectional formative qualitative study conducted in six purposively selected fishing communities in Kenya, Tanzania and Uganda. Potential participants were screened for eligibility on age (18+ years) and having stayed in the fishing community for more than 6 months. We collected data using introductory and focus group discussions, and in-depth interviews with key informants. Data focused on: history and patterns of mobility, migration in and out of fishing communities and the relationship between mobility and HIV infection. Since the interviews and discussions were not audio-recorded, detailed notes were taken and written up into full scripts for analysis. We conducted a thematic analysis using constant comparison analysis. RESULTS: Participants reported that women in fishing communities were highly mobile for work-related activities. Overall, we categorized mobility as travels over long and short distances or periods depending on the kind of livelihood activity women were involved in. Participants reported that women often travelled to new places, away from familiar contacts and far from healthcare access. Some women were reported to engage in high risk sexual behaviour and disengaging from HIV care. However, participants reported that women often returned to the fishing communities they considered home, or followed a seasonal pattern of work, which would facilitate contact with service providers. CONCLUSION: Women exhibited circular and seasonal mobility patterns over varying distances and duration away from their home communities. These mobility patterns may limit women's access to trial/health services and put them at risk of HIV-infection. Interventions should be tailored to take into account mobility patterns of seasonal work observed in this study

Sandfly Fever Sicilian Virus, Algeria

To determine whether sandfly fever Sicilian virus (SFSV) is present in Algeria, we tested sandflies for phlebovirus RNA. A sequence closely related to that of SFSV was detected in a Phlebotomus ariasi sandfly. Of 60 human serum samples, 3 contained immunoglobulin G against SFSV. These data suggest SFSV is present in Algeria

Disability and intimate partner violence: A cross-sectional study from Mwanza, Tanzania.

BACKGROUND: Women with disabilities are at heightened risk of experiencing intimate partner violence [IPV], although the mechanisms through which disability acts as a risk factor for IPV are not clear. OBJECTIVE: We analyzed cross-sectional data (n = 867) from Wave 3 of the MAISHA longitudinal study, conducted in Mwanza, Tanzania, to i) describe the levels of disability and IPV amongst women, and ii) to assess the association between level and type of disability and IPV experience. METHODS: IPV was assessed using the WHO Multi-Country study instrument. Levels of disability (none, mild and severe) were categorized based on responses to the Washington Group Short Set questions. We fitted logistic regression models to determine the risk of experiencing each type of IPV according to disability level and type of disability. RESULTS: We found significant associations between mild and severe disability and different types of IPV. For example, in multivariate analyses controlling for socio-demographic variables, women reporting severe disability were significantly more likely to report physical and/or sexual IPV, sexual IPV. controlling behaviors, economic IPV, and severe IPV, whereas for mild disability compared to no disability, physical and/or sexual IPV, sexual IPV, and economic IPV were significantly more likely to be reported. Cognitive disability was a significant correlate of all forms of IPV apart from physical IPV. CONCLUSIONS: Our findings that specific types of disability and not others were associated with an elevated risk of IPV exposure indicate the need for nuanced measurement and analysis of the association between disability and IPV

Prevalence of asymptomatic malaria infections in selected military camps in Tanzania

Background: Despite a decrease in malaria burden reported between 2000 and 2015, an increasing trend of malaria transmission has been recently reported in some endemic countries including Tanzania. Periodic monitoring to identify pocket areas for asymptomatic Plasmodium falciparum infection   is vital for malaria elimination efforts. The objective of this study was to determine prevalence of asymptomatic malaria infections among military recruits in selected camps in Tanzania. Methods: A cross-sectional study was conducted in 2015 at four military camps (Bulombora, Mgambo, Ruvu, and Rwamkoma) of National Service located in regions with varying malaria endemicity in Tanzania.  Finger prick blood samples collected from asymptomatic military recruits who had been at the camps for over two months were simultaneously tested using microscopy and malaria rapid diagnostic tests (mRDTs) to detect malaria parasite infections. Results: Malaria parasite prevalence among asymptomatic recruits was 20.3% and 19.4% by microscopy and mRDT respectively. There was moderate agreement (Kappa=0.724) between microscopy and mRDT test results. A significant difference (p<0.001) of malaria parasite prevalence among the four study camps was observed; ranging from 1.9% in Bulombora to 39.4% in Rwamkoma. The geometric mean parasite density was 11,053 asexual parasites/µl and most recruits (56.8%) had 200 to 1999 asexual parasites/µl. P. falciparum was the predominant (99.2%) malaria parasite species. Conclusion: Our study found high prevalence of asymptomatic malaria infections among military recruits in the selected camps, and this varied from one camp to another. The study has highlighted that public residence institutions such as military camps can be potential hotspots for malaria infection and therefore should not be skipped in routine national malaria surveillance system for monitoring trends of infection

Protecting migratory farmers in rural Tanzania using eave ribbons treated with the spatial mosquito repellent, transfluthrin.

BACKGROUND: Many subsistence farmers in rural southeastern Tanzania regularly relocate to distant farms in river valleys to tend to crops for several weeks or months each year. While there, they live in makeshift semi-open structures, usually far from organized health systems and where insecticide-treated nets (ITNs) do not provide adequate protection. This study evaluated the potential of a recently developed technology, eave ribbons treated with the spatial repellent transfluthrin, for protecting migratory rice farmers in rural southeastern Tanzania against indoor-biting and outdoor-biting mosquitoes. METHODS: In the first test, eave ribbons (0.1 m × 24 m each) treated with 1.5% transfluthrin solution were compared to untreated ribbons in 24 randomly selected huts in three migratory communities over 48 nights. Host-seeking mosquitoes indoors and outdoors were monitored nightly (18.00-07.00 h) using CDC light traps and CO2-baited BG malaria traps, respectively. The second test compared efficacies of eave ribbons treated with 1.5% or 2.5% transfluthrin in 12 huts over 21 nights. Finally, 286 farmers were interviewed to assess perceptions about eave ribbons, and their willingness to pay for them. RESULTS: In the two experiments, when treated eave ribbons were applied, the reduction in indoor densities ranged from 56 to 77% for Anopheles arabiensis, 36 to 60% for Anopheles funestus, 72 to 84% for Culex, and 80 to 98% for Mansonia compared to untreated ribbons. Reduction in outdoor densities was 38 to 77% against An. arabiensis, 36 to 64% against An. funestus, 63 to 88% against Culex, and 47 to 98% against Mansonia. There was no difference in protection between the two transfluthrin doses. In the survey, 58% of participants perceived the ribbons to be effective in reducing mosquito bites. Ninety per cent were willing to pay for the ribbons, the majority of whom were willing to pay but less than US$2.17 (5000 TZS), one-third of the current prototype cost. CONCLUSIONS: Transfluthrin-treated eave ribbons can protect migratory rice farmers, living in semi-open makeshift houses in remote farms, against indoor-biting and outdoor-biting mosquitoes. The technology is acceptable to users and could potentially complement ITNs. Further studies should investigate durability and epidemiological impact of eave ribbons, and the opportunities for improving affordability to users

Hand hygiene intervention to optimize helminth infection control: Design and baseline results of Mikono Safi-An ongoing school-based cluster-randomised controlled trial in NW Tanzania.

INTRODUCTION: Soil transmitted helminths (STH) can affect over 50% of children in some parts of Tanzania. Control measures involve annual deworming campaigns in schools, but re-infection is rapid. This paper presents the design and baseline survey results of an ongoing school-based cluster-randomised controlled trial in Kagera region, NW Tanzania. The trial aims to determine whether the effect of routine deworming on the prevalence of Ascaris lumbricoides and Trichuris trichiura infections among school aged children can be sustained when combined with a behaviour change intervention promoting handwashing with water and soap. METHODS: As part of the trial, a total of 16 schools were randomised to receive the intervention (N = 8) or as controls (N = 8). Randomisation was stratified per district and restricted to ensure pre-trial STH prevalence was balanced between study arms. The combination intervention to be tested comprises class-room based teacher-led health education, improvement of handwash stations, coloured nudges to facilitate handwashing and parental engagement sessions. The impact evaluation involves two cross-sectional surveys conducted at baseline and endline. The objectives of the baseline survey were: (i) to confirm whether the deworming campaign was successful, and identify and treat students still infected about 2 weeks after deworming, (ii) to document any baseline differences in STH prevalence between trial arms, and (iii) to assess handwashing behaviours, and access to water and sanitation at school and home. We randomly sampled 35 students per class in Grades 1-6 (an average of 200 children per school), stratified to ensure equal representation between genders. Assenting students were interviewed using a structured questionnaire and asked to provide a stool specimen. RESULTS: Results of the baseline survey conducted about 2 weeks after deworming shows balanced demographic and STH prevalence data across trial arms. We observed a low prevalence of ascariasis (< 5%) as expected; however, the prevalence of trichuriasis was still about 35% in both arms. CONCLUSION: The randomisation procedure was successful in achieving a balanced distribution of demographic characteristics and helminth infections between trial arms. The intervention is being rolled out. The current deworming treatment regimen may need to be revised with regards to the treatment of trichuriasis

Lack of association between genetic variants in the 19q13.32 region and CHD risk in the Algerian population: a population-based nested case-control study

Background: Coronary Heart Disease (CHD) is a major cause of morbidity and mortality over the world; intermediate traits associated with CHD commonly studied can be influenced by a combination of genetic and environmental factors. Objective: We found previously significant association between three genetic polymorphisms, and the lipid profile variations in the Algerian population. Considering these findings, we therefore decided to assess the relationships between these polymorphisms and CHD risk, Methods: We performed a population-based, cross-sectional study, of 787 individuals recruited in the city of Oran, in which, a nested case-control study for MetS, T2D, HBP, obesity and CHD were performed. Subjects were genotyped for four SNP rs7412, rs429358 rs4420638 and rs439401 located in the 19q13.32 region. Results: The T allele of rs439401 confers a high risk of hypertension with an odds ratio (OR) of 1.46 (95% CI [1.12-1.9], p = 0.006) and the G allele of rs4420638 was significantly associated with a decreased risk of obesity, OR 0.48 (95% CI [0.29-0.81], p = 0.004). No associations were found for MetS, T2D and CHD. Conclusion: Although the studied genetic variants were not associated with the risk of CHD, the 19q13.32 locus was associated with some of the cardiometabolic disorders in Algerian subjects