Coupling of Liquid and Surface Chemistry in Urea SCR Systems

Close-coupled selective catalytic reduction (SCR) systems are one method to deal with tightening emission legislation for NO$_x$ in internal combustion engines. Due to smaller mixing sections and at unfavourable boundary conditions, however, urea-water solution (UWS) droplets can impact on the SCR catalyst itself. To investigate this phenomenon further, this work develops a modeling capability of this process. Established mechanism for NH$_3$-SCR and HNCO hydrolysis from literature is integrated into DETCHEM$^{CHANNEL}$ and a 2D COMSOL model to simulate the influence in the SCR Channel. Simulations are validated against end-of-pipe experiments from literature and spatially resolved concentration profiles from a hot gas test rig with very good agreement. Finally, a channel simulation is coupled with a model to describe the catalytic decomposition of an urea droplet. The coupled simulation is able to simulate the influence of UWS droplet impact onto a catalyst channel. Fast droplet decomposition causes a peak in NH$_3$ and HNCO in the single channel and thus increases NO$_x$ conversion. However, the overall uniformity and efficiency are decreased, which is why droplet impact on the catalyst should be strictly avoided

A Qualitative Study of Perceived Risk for HIV Transmission among Police Officers in Dar es Salaam, Tanzania.

Understanding people's views about HIV transmission by investigating a specific population may help to design effective HIV prevention strategies. In addition, knowing the inherent sexual practices of such a population, as well as the risky circumstances that may facilitate HIV transmission, is crucial for the said strategies to become effective. In this article, we report how police officers in Dar es Salaam, Tanzania, perceived the problem of HIV and AIDS in their local context, particularly in relation to unsafe sexual practices. The study was done with the view to recommending ways by which HIV transmission could be minimised within the police force. The study was conducted among members of the police force in Dar es Salaam, Tanzania. Eight focus group discussions (FGDs) were conducted, with a total of 66 participants who were mixed in terms of age, gender, and marital status. Some of these were caregivers to patients with AIDS. Data were analysed using the interpretive description approach. The participants believed that both individual sexual behaviour and work-related circumstances were sources of HIV infection. They also admitted that they were being tempted to engage in risky sexual practices because of the institutional rules that prohibit officers from getting married during their training and for three years after. Nevertheless, as members of the Police Force, they stressed the fact that the risky sexual behaviour that exposes them to HIV is not limited to the force; it is rather a common problem that is faced by the general population. However, they complained, the nature of their job exposes them to road accident victims, subjecting them further to possible infection, especially when they have to handle these road accident casualties without proper protective gear. Individual sexual behaviour and job-related circumstances are worth investigating if proper advice is to be given to the police regarding HIV prevention strategies. In order to improve the lives of these police officers, there is a need to review the existing institutional rules and practices to accommodate individual sexual needs. In addition, improving their working environment may minimize the risk of HIV transmission from handling casualties in emergency situations

A Qualitative Exploration of the Mental Health and Psychosocial Contexts of HIV-Positive Adolescents in Tanzania

Although 85% of HIV-positive adolescents reside in sub-Saharan Africa, little is known about the psychosocial and mental health factors affecting their daily well-being. Identifying these contextual variables is key to development of culturally appropriate and effective interventions for this understudied and high-risk population. The purpose of this study was to identify salient psychosocial and mental health challenges confronted by HIV-positive youth in a resource-poor Tanzanian setting. A total of 24 qualitative interviews were conducted with a convenience sample of adolescents aged 12–24 receiving outpatient HIV care at a medical center in Moshi, Tanzania. All interviews were audio-recorded, transcribed, and coded using thematic analysis. Psychosocial challenges identified included loss of one or more parents, chronic domestic abuse, financial stressors restricting access to medical care and education, and high levels of internalized and community stigma among peers and other social contacts. Over half of youth (56%) reported difficulties coming to terms with their HIV diagnosis and espoused related feelings of self-blame. These findings highlight the urgent need to develop culturally proficient programs aimed at helping adolescents cope with these manifold challenges. Results from this study guided the development of Sauti ya Vijana (The Voice of Youth), a 10-session group mental health intervention designed to address the psychosocial and mental health needs of HIV-positive Tanzanian youth

Evidencing the clinical and economic burden of musculoskeletal disorders in Tanzania: Paving the way for urgent rheumatology service development

Since 1990, there has been a dramatic rise in noncommunicable diseases (NCDs) within low-and middleincome countries (LMICs); the burden of NCDs in LMICs rose from accounting for 39% of disability-adjusted life years in 1990 to 66% in 2019 [1]. In response to this growing burden, global, regional and national health institutions have become increasingly active in orchestrating a response to NCDs. The global response to NCDs has prioritized cardiovascular disease, cancer, chronic respiratory disease and diabetes, with the World Health Organization Regional Office in Africa adding region-specific NCD burdens, such as sickle cell disease, to broaden priorities [2]. Amidst this galvanization of efforts to tackle NCDs, musculoskeletal (MSK) conditions have been relatively overlooked and neglected, resulting in an urgent need for service development to respond to MSK conditions in LMICs [1]

Trends in HIV-1 prevalence and risk behaviours over 15 years in a rural population in Kilimanjaro region of Tanzania

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Use of antibiotics in poultry and poultry farmers- a cross-sectional survey in Pakistan

BackgroundAntimicrobial resistance (AMR) which has been ascribed to be due to community carriage of antibiotic-resistant bacteria is highly prevalent in the WHO South-East Asia region. One of the major reasons for this is the misuse of antibiotics in animal farming practices and at the community level, which threatens both human and animal health. However, this problem of antibiotic misuse in poultry farms and in respective farmers is not well studied in countries like Pakistan.MethodsWe conducted a cross-sectional study in rural Punjab to explore the current practices of antibiotic use in poultry and poultry farmers, associated factors, their healthcare-seeking behavior and biosecurity practices.ResultsIn the context of antibiotic use for poultry, 60% comprised of Colistin sulfate and Amoxicillin trihydrate whereas Colistin is considered as the last resort antibiotic. In addition, the significant consumption of antibiotics in poultry farms (60%) and poultry farmers (50%) was without prescription by either human health physicians or veterinarians. Most of the farms (85%) had no wastewater drainage system, which resulted in the direct shedding of poultry waste and antibiotic residue into the surrounding environment. The lack of farmers’ education, professional farm training and farming experience were the most significant factors associated with antibiotic use and knowledge of AMR.ConclusionOur study findings show that it is necessary for an integrated AMR policy with the inclusion of all poultry farmers to be educated, a mass awareness program to be undertaken and that strict antibiotic usage guidelines be available to them. Such initiatives are also important to ensure food safety and farm biosecurity practices

Multi-country evaluation of the durability of pyrethroid plus piperonyl-butoxide insecticide-treated nets: study protocol

BACKGROUND: Mass distributions of long-lasting insecticidal nets (LLINs) have contributed to large reductions in the malaria burden. However, this success is in jeopardy due in part to the increasing pyrethroid-resistant mosquito population as well as low LLINs coverage in various areas because the lifespan of LLINs is often shorter than the interval between replenishment campaigns. New insecticide-treated nets (ITNs) containing pyrethroid and piperonyl-butoxide (PBO) have shown a greater reduction in the incidence of malaria than pyrethroid LLINs in areas with pyrethroid-resistant mosquitoes. However, the durability (attrition, bio-efficacy, physical integrity and chemical retainment) of pyrethroid-PBO ITNs under operational settings has not been fully characterized. This study will measure the durability of pyrethroid-PBO ITNs to assess whether they meet the World Health Organization (WHO) three years of operational performance criteria required to be categorized as "long-lasting". METHODS: A prospective household randomized controlled trial will be conducted simultaneously in Tanzania, India and Cote d'Ivoire to estimate the field durability of three pyrethroid-PBO ITNs (Veeralin(R), Tsara(R) Boost, and Olyset(R) Plus) compared to a pyrethroid LLIN: MAGNet(R). Durability monitoring will be conducted up to 36 months post-distribution and median survival in months will be calculated. The proportion of ITNs: (1) lost (attrition), (2) physical integrity, (3) resistance to damage score, (4) meeting WHO bio-efficacy (>/= 95% knockdown after 1 h or >/= 80% mortality after 24 h for WHO cone bioassay, or >/= 90% blood-feeding inhibition or >/= 80% mortality after 24 h for WHO Tunnel tests) criteria against laboratory-reared resistant and susceptible mosquitoes, and insecticidal persistence over time will be estimated. The non-inferiority of Veeralin(R) and Tsara(R) Boost to the first-in-class, Olyset(R) Plus will additionally be assessed for mortality, and the equivalence of 20 times washed ITNs compared to field aged ITNs will be assessed for mortality and blood-feeding inhibition endpoints in the Ifakara Ambient Chamber Test, Tanzania. CONCLUSION: This will be the first large-scale prospective household randomized controlled trial of pyrethroid-PBO ITNs in three different countries in East Africa, West Africa and South Asia, simultaneously. The study will generate information on the replenishment intervals for PBO nets

The impacts of COVID-19 and its policy response on access and utilization of maternal and child health services in Tanzania: A mixed methods study.

The SARS-Cov-2 virus (COVID-19) has had a global social and economic impact. Despite the growing evidence, its effects on access and delivery of maternal and child health services in low-income countries are still unclear. This cross-sectional case study was conducted in Mjini Magharibi, Chake Chake, and Ilala districts in Tanzania to help fill this gap. The study combined qualitative and quantitative data collection methods, providing an account of the evolution of the pandemic and the associated control measures in Tanzania. We drew from 34 in-depth interviews, 60 semi-structured interviews, and 14 focus group discussions with key informants, patients, and health providers, and complemented the findings with a review of pandemic reports and health facility records. We followed the Standards for Reporting Qualitative Research (SRQR) to provide an account of the findings. Our account of the pandemic shows that there was at times an inconsistent policy response in Tanzania, with diverse control measures adopted at various stages of the epidemic. There was a perception that COVID-19 services were prioritized during the epidemic at the expense of regular ones. There were reports of reorganisation of health facilities, reallocation of staff, rescheduled antenatal and postnatal clinics, and reduced time for health education and child monitoring. Scarcity of essential commodities was reported, such as vaccines, equipment, and medical supplies. Such perceptions were in part supported by the routine utilization evidence in the three districts, showing a lower uptake of antenatal, postnatal, family planning, and immunization services, as well as fewer institutional deliveries. Our findings suggest that, although the policy response in Tanzania was erratic, it was rather fear of the pandemic itself and diversion of resources to control COVID-19, that may have contributed most to lower the utilization of mother and child services. For future emergencies, it will be crucial to ensure the policy response does not weaken the population's demand for services