Do Gifts Increase Consent to Home-based HIV Testing? A Difference-in-differences Study in Rural KwaZulu-Natal, South Africa

Background Despite the importance of HIV testing for controlling the HIV epidemic, testing rates remain low. Efforts to scale-up testing coverage and frequency in hard-to-reach and at-risk populations commonly focus on home-based HIV testing. This study evaluates the effect of a gift (a food voucher for families, worth US$ 5) on consent rates for home-based HIV testing.
Methods We use data on 18,478 men and women who participated in the 2009 and 2010 population-based HIV surveillance carried out by the Wellcome Trust Africa Centre for Health and Population Studies in rural KwaZulu-Natal, South Africa. Our quasi-experimental difference-in-differences approach controls for unobserved confounding in estimating the causal effect of the intervention on HIV testing consent rates.
Results Allocation of the gift to a family in 2010 increased the probability of family members consenting to test in 2010 by 25 percentage points (95% CI 21-30; p<0.001). The intervention effect persisted, slightly attenuated, in the year following the intervention (2011), further increasing intervention value for money.
Conclusions In HIV hyperendemic settings a gift can be highly effective at increasing consent rates for home-based HIV testing. Given the importance of HIV testing for treatment uptake and individual health, as well as for HIV treatment-and-prevention strategies and for monitoring the population impact of the HIV response, gifts should be considered as a supportive intervention for HIV testing initiatives where consent rates have been low.

Effect of fretting on fatigue performance of Ti-1023 titanium alloy

The plain fatigue and fretting fatigue tests of Ti-1023 titanium alloy were performed using a high-frequency push-pull fatigue testing machine. Both σmax versus number of cycles to failure curves were obtained for comparative analysis of the fretting effect on fatigue performance of the titanium alloy. Meanwhile, by analyzing the fracture of plain fatigue and fretting fatigue, the fretting scar and the fretting debris observed by scanning electron microscopy (SEM), the mechanism of fretting fatigue failure of Ti-1023 titanium alloy is discussed. The fretting fatigue strength of Ti-1023 titanium alloy is 175 MPa under 10 MPa contact pressure, which is 21% of plain fatigue strength (836 MPa). Under fretting condition, the Ti-1023 titanium alloy fatigue fracture failure occurs in a shorter fatigue life. When it comes to σmax versus number of cycles to failure curves, data points in the range of 106–107 cycles under plain fatigue condition moved to the range of 105–106 under fretting fatigue condition. The integrity of the fatigue specimen surface was seriously damaged under the effect of fretting. With the alternating stress loaded on specimen, the stress concentrated on the surface of fretting area, which brought earlier the initiation and propagation of crack.

Influence of embedded length on strength of BFRP rods bonded parallel to the grain in low grade timber by pullout-bending tests

Bonded-in rod connections in timber possess many desirable attributes in terms of efficiency, manufacture, performance, aesthetics and cost. In recent years research has been conducted on such connections using fibre reinforced polymers (FRPs) as an alternative to steel. This research programme investigates the pull-out capacity of Basalt FRP rods bonded-in in low grade Irish Sitka Spruce. Embedded length is thought to be the most influential variable contributing to pull- out capacity of bonded-in rods after rod diameter. Previous work has established an optimum embedded length of 15 times the hole diameter. However, this work only considered the effects of axial stress on the bond using a pull-compression testing system which may have given an artificially high pull out capacity as bending effects were neglected. A hinge system was utilised that allows the effects of bending force to be taken in to consideration along with axial forces in a pull-out test. This paper describes an experimental programme where such pull-bending tests were carried out on samples constructed of 12mm diameter BFRP bars with a 2mm glueline thickness and embedded lengths between 80mm and 280mm bonded-in to low-grade timber with an epoxy resin. Nine repetitions of each were tested. A clear increase in pull-out strength was found with increasing embedded length.

Identification of synergists that potentiate the action of polymyxin B against Burkholderia cenocepacia

Burkholderia cenocepacia and other members of the Burkholderia cepacia complex (Bcc) are highly multidrug-resistant bacteria that cause severe pulmonary infections in patients with cystic fibrosis. A screen of 2686 compounds derived from marine organisms identified molecules that could synergize with polymyxin B to inhibit growth of B. cenocepacia. At 1 μg/ml, five compounds synergized with polymyxin B and inhibited the growth of B. cenocepacia by more than 70% compared to growth in polymyxin B alone. Follow-up testing revealed that one compound from the screen, the aminocoumarin antibiotic novobiocin, synergized with polymyxin B and colistin against tobramycin-resistant clinical isolates of B. cenocepacia and Burkholderia multivorans. In parallel, we show that novobiocin sensitivity is common among Bcc species and these bacteria are even more susceptible to an alternative aminocoumarin, clorobiocin, which also had an additive effect with polymyxin B against B. cenocepacia. These studies support using aminocoumarin antibiotics to treat Bcc infections and show that synergizers can be found to increase the efficacy of antimicrobial peptides and polymyxins against Bcc bacteria.

Testing the possible negative association of type 1 diabetes and atopic disease by analysis of the interleukin 4 receptor gene

Variations in the interleukin 4 receptor A (IL4RA) gene have been reported to be associated with atopy, asthma, and allergy, which may occur less frequently in subjects with type 1 diabetes (T1D). Since atopy shows a humoral immune reactivity pattern, and T1D results from a cellular (T lymphocyte) response, we hypothesised that alleles predisposing to atopy could be protective for T1D and transmitted less often than the expected 50% from heterozygous parents to offspring with T1D. We genotyped seven exonic single nucleotide polymorphisms (SNPs) and the -3223 C>T SNP in the putative promoter region of IL4RA in up to 3475 T1D families, including 1244 Finnish T1D families. Only the -3223 C>T SNP showed evidence of negative association (P=0.014). There was some evidence for an interaction between -3233 C>T and the T1D locus IDDM2 in the insulin gene region (P=0.001 in the combined and P=0.02 in the Finnish data set). We, therefore, cannot rule out a genetic effect of IL4RA in T1D, but it is not a major one.

The push and pull between religion and ethnicity: The case of loyalists in Northern Ireland

This paper uses a case study of a largely religiously non-practising group, working class loyalists in Northern Ireland, to explore the relationship between religion and ethnicity in divided societies. It finds that loyalists often turn to religion habitually in times of insecurity to provide justification for conflict. But religion does not just prop up deeper ethnic identities. Religion has meaning and content itself that is sometimes tension with oppositional ethnic identities and, in some cases, can transform them totally. This produces a complex set of relationships in which religion and ethnicity push and pull against one another in the lives of individuals, neither dominating fully over the other.

Pull-out behaviour of axially loaded basalt fibre reinforced polymer (BFRP) rods bonded parallel to the grain of glulam elements

Synopsis: Bonded-in rod timber joints off er several advantages over conventional types of joint, including high local force transfer, very stiff connections, and improved ?re and aesthetic properties since the connection is completely hidden in the insulating timber members. More recently, the use of ?bre reinforced polymer (FRP) as a connecting rod, alternative to steel rods, in bonded-in rod connections for timber structures has been investigated. However, the investigation into the behaviour of such joints is limited, in particular, connections involving basalt ?bre reinforced polymers (BFRP) bars - which is the primary focus of this research. This paper presents an experimental programme conducted to investigate the behaviour of bonded-in BFRP bars loaded parallel to the grain of glulam members. Tensile pull-out tests were conducted to examine the effect of bonded length and bond stress-slip on the structural capacity of the connection. An analytical design expression for predicting pull-out capacity is proposed and the results have been compared with some established design equations. It was found that pull-out load increased approximately linearly with the bonded length, up to maximum which occurred at a bonded length of 15 times the hole diameter, and did not increase beyond this bonded length. The most signi?cant failure modes were failure at the timber/adhesive interface followed by pullout of the BFRP rod. Increased bonded lengths resulted in higher bond slip values compared to lower equivalent bonded lengths. The proposed design model gave the best predictions of pull-out capacity compared with other existing models.

Using solute/ micro organism comparative tracer testing to investigate hydrogeological heterogeneity in a fluvioglacial sand and gravel aquifer.

Groundwater drawn from fluvioglacial sand and gravel aquifers form the principal source of drinking water in many part of central Western Europe. High population densities and widespread organic agriculture in these same areas constitute hazards that may impact the microbiological quality of many potable supplies. Tracer testing comparing two similarly sized bacteria (E.coli and P. putida) and the smaller bacteriophage (H40/1) with the response of non-reactive solute tracer (uranine) at the decametre scale revealed that all tracers broke through up to 100 times more quickly than anticipated using conventional rules of thumb. All microbiological tracer responses were less disperse than the solute, although bacterial peak relative concentrations consistently exceeded those of the solute tracer at one sampling location reflecting exclusion processes influencing micro biological tracer migration. Relative recoveries of H40/1 and E.coli proved consistent at both monitoring wells, while responses of H40/1 and P.putida differed. Examination of exposures of the upper reaches of the aquifer in nearby sand and gravel quarries revealed the aquifer to consist of laterally extensive layers of open framework (OW) gravel enveloped in finer grained gravelly sand. Granulometric analysis of these deposits suggested that the OW gravel was up to two orders of magnitude more permeable than the surrounding deposits giving rise to the preferential flow paths. By contrast fine grained lenses of silty sand within the OW gravels are suspected to play an important role in the exclusion processes that permit solutes to access them but exclude larger micro organisms.

Numbered-up gas-liquid micro/milli channels reactor with modular flow distributor

Gas-liquid processing in microreactors remains mostly restricted to the laboratory scale due to the complexity and expenditure needed for an adequate numbering-up with a uniform flow distribution. Here, the numbering-up is presented for multi-phase (gas-liquid) flow in microreactor suitable for a production capacity of kg/h. Based on the barrier channels concept, the barrier-based micro/milli reactor (BMMR) is designed and fabricated to deliver flow non-uniformity of less than 10%. The BMMR consists of eight parallel channels all operated in the Taylor flow regime and with a liquid flow rate up to 150. mL/min. The quality of the flow distribution is reported by studying two aspects. The first aspect is the influence of different viscosities, surface tensions and flow rates. The second aspect is the influence of modularity by testing three different reaction channels type: (1) square channels fabricated in a stainless steel plate, (2) square channels fabricated in a glass plate, and (3) circular channels (capillaries) made of stainless steel. Additionally, the BMMR is compared to that of a single channel regard the slug and bubble lengths and bubble generation frequency. The results pave the ground for bringing multi-phase flow in microreactor one step closer for large scale production via numbering-up. © 2012 Elsevier B.V.

Pull-out behaviour of axially loaded Basalt Fibre Reinforced Polymer (BFRP) rods bonded perpendicular to the grain of glulam elements

The behaviour of Basalt Fibre Reinforced Polymer (BFRP) loaded perpendicular to glulam timber elements was investigated. It was found that pull-out load increased approximately linearly with the bonded length up to maximum which occurred at a bonded length of 250 mm (~15 times the hole diameter) and did not increase beyond this bonded length. Failure mode of the samples was mostly shear fracture which was located at the cylindrical zone at the timber/adhesive interface. Increased bonded lengths resulted in corresponding decrease in interfacial bond stress. At 250 mm bonded length, the pull-out capacity of the proposed design model was about 2% lower than that of the tests. The results also showed that the bond stress of the theoretical model (at the ascending and descending branches) of the stress–slip curve was approximately 5–10% of that of the experiment.

Fetal Umbilical Artery Doppler Pulsatility Index as a Predictor of Cardiovascular Risk Factors in Children - A Long-Term Follow Up Study

Abstract Objective To determine if high umbilical artery Doppler (UAD) pulsatility index (PI) is associated with cardio-vascular (CV) risk-factors in children at age 12 years. Methods We studied 195 children at age 12 years who had had in-utero UAD studies performed at 28 weeks gestation. The children were grouped according to whether their umbilical Doppler PI was high (indicating poor feto-placental circulation) or normal. At age 12 years we assessed CV risk factors, including anthropometric measures, blood pressure, pulse wave velocity (a measure of arterial compliance), cardio-respiratory fitness and homocysteine and cholesterol serum levels. Results Compared with children with a normal UAD PI (N=88), the children (N=107) with high UAD PI had higher resting pulse rate (p=0.04), higher pulse wave velocity (p=0.046), higher serum homocysteine levels (p=0.032) and reduced arterial compliance (7.58 v 8.50 m/sec, p=0.029) using univariate analysis. These differences were not present when adjusting for cofounders was modelled. Conclusion High PI on UAD testing in-utero may be associated with increased likelihood of some cardio-vascular risk factors at age 12-years but confounding variables may be as important. Our study raises possible long-term benefits of in-utero UAD measurements.

Measuring specific parameters in pretensioned concrete members using a single testing technique

Pretensioned concrete members are designed and manufactured by using at least two materials: concrete and prestressing reinforcement. Also, two main stages must be considered: prestress transfer and member loading. Hence, the behavior of these members depends strongly on the reinforcement-to-concrete bond performance and prestress losses. In this paper, a testing technique to measure the specific parameters related with the involved phenomena is presented. The testing technique is based on the analysis of series of specimens varying in embedment length to simulate several cross sections at only one end of a pretensioned concrete member. Each specimen is characterized by means of the sequential release of the prestress transfer (detensioning) and the pull-out (loading) operation. The test provides data on prestressing force, transmission length (initial and long-term), anchorage length (without and with slip), reinforcement slips, bond stresses, longitudinal concrete strains, concrete modulus of elasticity, and prestress losses (instantaneous and time-dependent).

Pull-out behaviour of steel grid soil reinforcement embedded in silty sand

This paper investigates the pull-out behaviour (particularly the bearing resistance) of a steel grid reinforcement embedded in silty sand using laboratory tests and numerical analyses. It is demonstrated that the various common analytical equations for calculating the bearing component of pull-out resistance give a wide range of calculated values, up to about 200% disparity. The disparity will increase further if the issue of whether to use the peak or critical state friction angle is brought in. Furthermore, these equations suggest that the bearing resistance factor, N, is only a function of soil friction angle which is not consistent with some design guidelines. In this investigation, a series of large scale laboratory pull-out tests under different test pressures were conducted. The test results unambiguously confirmed that the N factor is a function of test pressure. A modified equation for calculating N is also proposed. To have more in-depth understanding of the pull-out behaviour, the tests were modelled numerically. The input parameters for the numerical analysis were obtained from laboratory triaxial tests. The analysis results were compared with the experimental results. Good agreement between experimental and numerical results was achieved if the strain-softening behaviour from peak strength to critical state condition was captured by the soil model used. © 2013 Elsevier Ltd.