Education, Employment and Earnings of Secondary School-Leavers in Tanzania: Evidence from a Tracer Study

The extent of information on labour market outcomes and the earnings of educated groups in Tanzania, and Sub-Saharan Africa more generally, are limited. This is particularly so for individuals who fail to gain access to wage employment and are required to rely on exploiting self-employment opportunities. The current paper, using a recently completed tracer survey of secondary school completers, analyses the impact of education and training on individual welfare through the estimation of earnings equations. Our empirical evidence suggests that the rates of return to educational qualifications are not negligible and, at the margin, provide an investment incentive. However, we find little evidence of human capital effects in the earnings determination process in the self-employment sector. Information contained in the tracer survey allowed the introduction of controls for father’s educational background and a set of school fixed effects designed to proxy for school quality and potential labour market network effects. The analysis shows that the inclusion of these controls tends to reduce the estimated rates of return to educational qualifications. This emphasizes the potential confounding role of school quality/network effects and parental background for rate of return analysis. We would argue that a failure to control for such background variables potentially leads to an over-statement in the estimated returns to education. A comparison of our results with evidence from other countries in the region shows that despite an extremely small secondary and university education system the private rates of return to education in the Tanzanian wage employment sector are relatively low.

University Research Supports Groundwater Availability Studies of the Hueco Bolson Aquifer, El Paso/Juarez Area

Water supply and water quality problems facing the City of El Paso and Ciudad Juarez are complex and interrelated. The twin cities share the water resources of the Hueco Bolson, a Tertiary and Quaternary basin fill aquifer that spans the international border. The binational metroplex is located at the junction between the western edge of Texas and the northernmost part of Chihuahua, Mexico. Over-pumping of the Hueco Bolson aquifer has resulted in drawdown of the water table, encroachment of brackish groundwater, and the early retirement of wells. In response to these issues, Mexican and American universities formed a partnership to study the surface and ground-water resources of the El Paso/Juarez area. Governmental agencies are participating in the project by providing existing data, access to water wells, and other support services. The research team is applying a suite of isotopic tracers to provide an understanding of the spatial dynamics of the aquifers by tracing water from areas of recharge to regions of discharge. The team is also using a variety of geochemical and isotopic tracers to answer questions about increasing salinity in the developed parts of the aquifer. With an increased understanding of the flowpaths of the aquifer systems, the team is addressing stream-aquifer interactions between the groundwater systems and the Rio Grande. By combining an understanding of isotopic and geochemical changes in the river system with the information about the groundwater systems, the team is calculating fluxes of water and solutes from the groundwater system to the river system. Finally, this geochemical and isotopic information is being used by the municipal partners to constrain physical and management models of groundwater to utilize the fresh and saline water resources of the Hueco Bolson more effectively

Development of a double-pole double-throw radio frequency micro electro-mechanical systems switch using an ‘S’ shaped pivot

This paper investigates the design of a novel pivot for a seesaw, RF MEMS, double-pole double-throw (DPDT) switch, which has been developed to operate within mobile communication systems and devices. The pivot employs a unique ‘S’ structure at the nano scale, in the form of a, which helps to keep von-Mises stresses below 21 MPa. The pivot requires less pulling force than similar designs due to its flexibility which allows the beam and contacts a greater space of separation while the switch is off. This in turn results in improved contact isolation of greater than −77 dB at 5 GHz. The RF MEMS switch is an improvement over the previously published paper (Al-Amin et al. in International symposium on microelectronics, vol 2013, no 1, pp 000831–000835, 2013. doi:10.1109/ECS.2014.6892558), since the pulling force of the electrostatic plates can be generated with a voltage which is greatly reduced from 14 to 8 V using the same electrostatic plate area size. The switch is a progression from SPST and DPDT seesaw switching since it provides improved flexibility over the previously described devices. With the redesign of the pivot the switch attains a greater ‘air-gap’ between the contacts when open-circuited which therefore allows for improved isolation during the off-state

Spread, circulation, and evolution of the Middle East respiratory syndrome coronavirus

The Middle East respiratory syndrome coronavirus (MERS-CoV) was first documented in the Kingdom of Saudi Arabia (KSA) in 2012 and, to date, has been identified in 180 cases with 43% mortality. In this study, we have determined the MERS-CoV evolutionary rate, documented genetic variants of the virus and their distribution throughout the Arabian peninsula, and identified the genome positions under positive selection, important features for monitoring adaptation of MERS-CoV to human transmission and for identifying the source of infections. Respiratory samples from confirmed KSA MERS cases from May to September 2013 were subjected to whole-genome deep sequencing, and 32 complete or partial sequences (20 were ≥99% complete, 7 were 50 to 94% complete, and 5 were 27 to 50% complete) were obtained, bringing the total available MERS-CoV genomic sequences to 65. An evolutionary rate of 1.12 × 10−3 substitutions per site per year (95% credible interval [95% CI], 8.76 × 10−4; 1.37 × 10−3) was estimated, bringing the time to most recent common ancestor to March 2012 (95% CI, December 2011; June 2012). Only one MERS-CoV codon, spike 1020, located in a domain required for cell entry, is under strong positive selection. Four KSA MERS-CoV phylogenetic clades were found, with 3 clades apparently no longer contributing to current cases. The size of the population infected with MERS-CoV showed a gradual increase to June 2013, followed by a decline, possibly due to increased surveillance and infection control measures combined with a basic reproduction number (R0) for the virus that is less than 1

Mineral maturity and crystallinity index are distinct characteristics of bone mineral

The purpose of this study was to test the hypothesis that mineral maturity and crystallinity index are two different characteristics of bone mineral. To this end, Fourier transform infrared microspectroscopy (FTIRM) was used. To test our hypothesis, synthetic apatites and human bone samples were used for the validation of the two parameters using FTIRM. Iliac crest samples from seven human controls and two with skeletal fluorosis were analyzed at the bone structural unit (BSU) level by FTIRM on sections 2–4 lm thick. Mineral maturity and crystallinity index were highly correlated in synthetic apatites but poorly correlated in normal human bone. In skeletal fluorosis, crystallinity index was increased and maturity decreased, supporting the fact of separate measurement of these two parameters. Moreover, results obtained in fluorosis suggested that mineral characteristics can be modified independently of bone remodeling. In conclusion, mineral maturity and crystallinity index are two different parameters measured separately by FTIRM and offering new perspectives to assess bone mineral traits in osteoporosis

Block of death-receptor apoptosis protects mouse cytomegalovirus from macrophages and is a determinant of virulence in immunodeficient hosts.

The inhibition of death-receptor apoptosis is a conserved viral function. The murine cytomegalovirus (MCMV) gene M36 is a sequence and functional homologue of the human cytomegalovirus gene UL36, and it encodes an inhibitor of apoptosis that binds to caspase-8, blocks downstream signaling and thus contributes to viral fitness in macrophages and in vivo. Here we show a direct link between the inability of mutants lacking the M36 gene (ΔM36) to inhibit apoptosis, poor viral growth in macrophage cell cultures and viral in vivo fitness and virulence. ΔM36 grew poorly in RAG1 knockout mice and in RAG/IL-2-receptor common gamma chain double knockout mice (RAGγC(-/-)), but the depletion of macrophages in either mouse strain rescued the growth of ΔM36 to almost wild-type levels. This was consistent with the observation that activated macrophages were sufficient to impair ΔM36 growth in vitro. Namely, spiking fibroblast cell cultures with activated macrophages had a suppressive effect on ΔM36 growth, which could be reverted by z-VAD-fmk, a chemical apoptosis inhibitor. TNFα from activated macrophages synergized with IFNγ in target cells to inhibit ΔM36 growth. Hence, our data show that poor ΔM36 growth in macrophages does not reflect a defect in tropism, but rather a defect in the suppression of antiviral mediators secreted by macrophages. To the best of our knowledge, this shows for the first time an immune evasion mechanism that protects MCMV selectively from the antiviral activity of macrophages, and thus critically contributes to viral pathogenicity in the immunocompromised host devoid of the adaptive immune system