A case investigation into causes of premature rutting failures in rehabilitated asphalt pavements in Tanzania

Tanzania was faced with high incidences of premature rutting failures on their asphalt pavements. Some pavements experienced failures within one to two years after construction/rehabilitation. The objective of this investigation was to identify the factors which contributed to the observed failures on five rehabilitated road sections on a national highway in Tanzania. Pavement temperature data collection, traffic surveys, visual inspection, rut depth measurements, and Falling Weight Deflectometer tests constituted the main activities of the field investigation reported in this paper. Laboratory study included a visual assessment of cores extracted from the studied road sections to determine both physical and engineering properties including density, stiffness, strength, aggregate shape properties, grading and physio-chemical tests on the recovered binders. The results of the study indicated that the degree and extent of rutting on the investigated road sections was rated as severe., i.e., rutting ranged from 38 to 138 mm on the five sections when compared to the acceptable threshold value of 15 mm for high volume roads in Tanzania. The elastic deflection results indicated that the underlying layers of the pavement system were generally in a sound condition, which validated the suggestion that the rutting observed was mostly confined to the asphalt concrete layers. Factors such as relatively high axle loads, poor asphalt mixes and possibly inadequate quality control during construction and rehabilitation were suspected to contribute to the rutting on the sections. Practical measures recommended to the roads agency to avert future occurrences are provided in this paper.The Tanzania National Roads Agency.https://www.astm.org/products-services/standards-and-publications/journal-of-testing-and-evaluation.htmlhj2024Civil EngineeringSDG-09: Industry, innovation and infrastructur

Community Resources and Educational Opportunities in Detroit: Baseline Assessment of Academic Progress Using the 2005-2009 Cohort of High School Students

This baseline report was prepared for the Detroit Schools-Higher Education Consortium. The report provided research support for educational improvement efforts by this consortium of universities and community-­based organizations working in collaboration with Detroit schools.This research report contributes a community resource theory of change applied to a Detroit Public Schools (DPS) case study of high school students. The research study examines changes in Detroit Education from 2000 to 2010, including policy and demographic changes. We also examined the impact of community resources on educational opportunities using a 2005-2009 student cohort database, Census data, and information on community resources. We examined three student outcomes: on-time graduation rate, grade point average (GPA), and school transfer during high school. The study proposes and tests a community resources theory of educational opportunity supporting Detroit students. The results support a community resource theory of change that includes more community-school partnerships in neighborhoods.Ford Foundationhttps://deepblue.lib.umich.edu/bitstream/2027.42/150103/1/Detroit Baseline Assessment Report (2019).pdfDescription of Detroit Baseline Assessment Report (2019).pdf : Main Working Repor

Fermented Food for Life: Stories of Inspiration, Struggle & Success

The Fermented Food for Life” project aims to improve food and nutrition security by increasing local production, distribution and consumption of health-promoting probiotic fermented yoghurt in Kenya, Tanzania, and Uganda, targeting to reach 250,000 consumers in the three countries by its end in June 2018. A pro-poor value chain-based business model was identified as a common approach to achieve project’s main objective. In Uganda, over 100 production units of probiotic yoghurt are up and running across the whole country reaching at least 60,000 regular consumers. The project supported also the establishment of 58 production units in Tanzania and 37 in Kenya, producing in total around 14,000 litres of probiotic yoghurt per week. In Tanzania and Uganda, 56% of production units are owned by women, and 68% of all people involved in probiotic yoghurt production and sales are female. The project has also provided a unique opportunity for employment of rural youth involved in the distribution of yoghurt. Partners in project’s implementation include Heifer International, Jomo Kenyatta University of Agriculture and Technology, University of Western Ontario and Yoba for Life Foundation. The project is undertaken with the financial support of Canada’s International Development Research Centre (IDRC), www.idrc.ca and the Government of Canada, provided through Global Affairs Canada (GAC), www.international.gc.ca Collected here are stories about the Fermented Food for Life project

T Cells Specific for a Mycobacterial Glycolipid Expand after Intravenous Bacillus Calmette-Guérin Vaccination

Intradermal vaccination with Mycobacterium bovis bacillus Calmette-Guérin (BCG) protects infants from disseminated tuberculosis, and i.v. BCG protects nonhuman primates (NHP) against pulmonary and extrapulmonary tuberculosis. In humans and NHP, protection is thought to be mediated by T cells, which typically recognize bacterial peptide Ags bound to MHC proteins. However, during vertebrate evolution, T cells acquired the capacity to recognize lipid Ags bound to CD1a, CD1b, and CD1c proteins expressed on APCs. It is unknown whether BCG induces T cell immunity to mycobacterial lipids and whether CD1-restricted T cells are resident in the lung. In this study, we developed and validated Macaca mulatta (Mamu) CD1b and CD1c tetramers to probe ex vivo phenotypes and functions of T cells specific for glucose monomycolate (GMM), an immunodominant mycobacterial lipid Ag. We discovered that CD1b and CD1c present GMM to T cells in both humans and NHP. We show that GMM-specific T cells are expanded in rhesus macaque blood 4 wk after i.v. BCG, which has been shown to protect NHP with near-sterilizing efficacy upon M. tuberculosis challenge. After vaccination, these T cells are detected at high frequency within bronchoalveolar fluid and express CD69 and CD103, markers associated with resident memory T cells. Thus, our data expand the repertoire of T cells known to be induced by whole cell mycobacterial vaccines, such as BCG, and show that lipid Ag-specific T cells are resident in the lungs, where they may contribute to protective immunity

Introducing a multi-site program for early diagnosis of HIV infection among HIV-exposed infants in Tanzania

<p>Abstract</p> <p>Background</p> <p>In Tanzania, less than a third of HIV infected children estimated to be in need of antiretroviral therapy (ART) are receiving it. In this setting where other infections and malnutrition mimic signs and symptoms of AIDS, early diagnosis of HIV among HIV-exposed infants without specialized virologic testing can be a complex process. We aimed to introduce an Early Infant Diagnosis (EID) pilot program using HIV DNA Polymerase Chain Reaction (PCR) testing with the intent of making EID nationally available based on lessons learned in the first 6 months of implementation.</p> <p>Methods</p> <p>In September 2006, a molecular biology laboratory at Bugando Medical Center was established in order to perform HIV DNA PCR testing using Dried Blood Spots (DBS). Ninety- six health workers from 4 health facilities were trained in the identification and care of HIV-exposed infants, HIV testing algorithms and collection of DBS samples. Paper-based tracking systems for monitoring the program that fed into a simple electronic database were introduced at the sites and in the laboratory. Time from birth to first HIV DNA PCR testing and to receipt of test results were assessed using Kaplan-Meier curves.</p> <p>Results</p> <p>From October 2006 to March 2007, 510 HIV-exposed infants were identified from the 4 health facilities. Of these, 441(87%) infants had an HIV DNA PCR test at a median age of 4 months (IQR 1 to 8 months) and 75(17%) were PCR positive. Parents/guardians for a total of 242(55%) HIV-exposed infants returned to receive PCR test results, including 51/75 (68%) of those PCR positive, 187/361 (52%) of the PCR negative, and 4/5 (80%) of those with indeterminate PCR results. The median time between blood draw for PCR testing and receipt of test results by the parent or guardian was 5 weeks (range <1 week to 14 weeks) among children who tested PCR positive and 10 weeks (range <1 week to 21 weeks) for those that tested PCR negative.</p> <p>Conclusions</p> <p>The EID pilot program successfully introduced systems for identification of HIV-exposed infants. There was a high response as hundreds of HIV-exposed infants were registered and tested in a 6 month period. Challenges included the large proportion of parents not returning for PCR test results. Experience from the pilot phase has informed the national roll-out of the EID program currently underway in Tanzania.</p

Multiple Origins and Regional Dispersal of Resistant dhps in African Plasmodium falciparum Malaria

Cally Roper and colleagues analyze the distribution of sulfadoxine resistance mutations and flanking microsatellite loci to trace the emergence and dispersal of drug-resistant Plasmodium falciparum malaria in Africa

The costs of introducing artemisinin-based combination therapy: evidence from district-wide implementation in rural Tanzania

BACKGROUND\ud \ud The development of antimalarial drug resistance has led to increasing calls for the introduction of artemisinin-based combination therapy (ACT). However, little evidence is available on the full costs associated with changing national malaria treatment policy. This paper presents findings on the actual drug and non-drug costs associated with deploying ACT in one district in Tanzania, and uses these data to estimate the nationwide costs of implementation in a setting where identification of malaria cases is primarily dependant on clinical diagnosis.\ud \ud METHODS\ud \ud Detailed data were collected over a three year period on the financial costs of providing ACT in Rufiji District as part of a large scale effectiveness evaluation, including costs of drugs, distribution, training, treatment guidelines and other information, education and communication (IEC) materials and publicity. The district-level costs were scaled up to estimate the costs of nationwide implementation, using four scenarios to extrapolate variable costs.\ud \ud RESULTS\ud \ud The total district costs of implementing ACT over the three year period were slightly over one million USD, with drug purchases accounting for 72.8% of this total. The composite (best) estimate of nationwide costs for the first three years of ACT implementation was 48.3 million USD (1.29 USD per capita), which varied between 21 and 67.1 million USD in the sensitivity analysis (2003 USD). In all estimates drug costs constituted the majority of total costs. However, non-drug costs such as IEC materials, drug distribution, communication, and health worker training were also substantial, accounting for 31.4% of overall ACT implementation costs in the best estimate scenario. Annual implementation costs are equivalent to 9.5% of Tanzania's recurrent health sector budget, and 28.7% of annual expenditure on medical supplies, implying a 6-fold increase in the national budget for malaria treatment.\ud \ud CONCLUSION\ud \ud The costs of implementing ACT are substantial. Although drug purchases constituted a majority of total costs, non-drug costs were also considerable. It is clear that substantial external resources will be required to facilitate and sustain effective ACT delivery across Tanzania and other malaria-endemic countries

Secure Communication for the IoT : EDHOC and (Group) OSCORE Protocols

Communication security of an Internet-of-Things (IoT) product depends on the variety of protocols employed throughout its lifetime. The underlying low-power radio communication technologies impose constraints on maximum transmission units and data rates. Surpassing maximum transmission unit thresholds has an important effect on the efficiency of the solution: transmitting multiple fragments over low-power IoT radio technologies is often prohibitively expensive. Furthermore, IoT communication paradigms such as one-to-many require novel solutions to support the applications executing on constrained devices. Over the last decade, the Internet Engineering Task Force (IETF) has been working through its various Working Groups on defining lightweight protocols for Internet-of-Things use cases. “Lightweight” refers to the minimal processing overhead, memory footprint and number of bytes in the air, compared to the protocol counterparts used for non-constrained devices in the Internet. This article overviews the standardization efforts in the IETF on lightweight communication security protocols. It introduces EDHOC, a key exchange protocol, as well as OSCORE and Group OSCORE, application data protection protocols adapted for securing IoT applications. The article additionally highlights the design considerations taken into account during the design of these protocols, an aspect not present in the standards documents. Finally, we present an evaluation of these protocols in terms of the message sizes, and we compare them with the non-constrained counterpart, the (D)TLS protocol. We demonstrate that the novel key exchange protocol EDHOC achieves ×5 reduction over DTLS 1.3 authenticated with pre-shared keys in terms of total number of bytes transmitted over the air, while keeping the benefits of authentication with asymmetric credentials

Assessment of traffic data for road rehabilitation design : a case study of the Korogwe-Mombo road section in Tanzania

Traffic loading is one of key inputs for new and rehabilitation designs of pavement. Heavy vehicles cause the most structural damage to pavements; hence, as part of the pavement design process, heavy vehicle volume, and axle load surveys are typically carried out to assist with the accurate estimation of the cumulative traffic loading over a design period. Traffic volumes, axle loads, and the ultimate cumulative traffic loading often fluctuate due to factors such as varying motorist population and economic activities along the length of the road. This paper presents a comparative assessment of traffic loading estimated for the rehabilitation design in 2005, and the actual measured site-specific traffic loading in 2015. The design traffic loading was also compared with the projected future traffic loading for the Korogwe-Mombo road section along the T2 trunk road that connects Tanzania’s business hub of Dar es Salaam with the northern regional cities. The study found, inter alia, that the cumulative traffic loading based on the 2015 measured site-specific traffic data is approximately 2.8 times higher than the design traffic loading based on the 2005 traffic data, which illustrates the importance of using accurate and reliable site-specific traffic data during pavement design. The implications of the findings for rehabilitation design are presented in this paper, along with discussions on the contribution of heavy traffic loading to rutting/permanent deformation that occurred on the surface asphalt layer along the Korogwe-Mombo road section. To improve the accurate determination of traffic loading, traffic studies should ideally be conducted over a long period (typically over one year). However, this is not practical and cost effective when traditional manual methods are used. Hence, it is recommended that road agencies should consider the use of portable automated traffic and Weigh-In-Motion (WIM) monitoring systems.The Tanzania National Roads Agency (TANROADS), the South African Council for Scientific and Industrial Research (CSIR) and the South African National Research Foundation (NRF).https://www.astm.org/DIGITAL_LIBRARY/JOURNALS/TESTEVALam2020Civil Engineerin