WaveScript: A Case-Study in Applying a Distributed Stream-Processing Language

Applications that combine live data streams with embedded, parallel,and distributed processing are becoming more commonplace. WaveScriptis a domain-specific language that brings high-level, type-safe,garbage-collected programming to these domains. This is made possibleby three primary implementation techniques. First, we employ a novelevaluation strategy that uses a combination of interpretation andreification to partially evaluate programs into stream dataflowgraphs. Second, we use profile-driven compilation to enable manyoptimizations that are normally only available in the synchronous(rather than asynchronous) dataflow domain. Finally, we incorporatean extensible system for rewrite rules to capture algebraic propertiesin specific domains (such as signal processing).We have used our language to build and deploy a sensor-network for theacoustic localization of wild animals, in particular, theYellow-Bellied marmot. We evaluate WaveScript's performance on thisapplication, showing that it yields good performance on both embeddedand desktop-class machines, including distributed execution andsubstantial parallel speedups. Our language allowed us to implementthe application rapidly, while outperforming a previous Cimplementation by over 35%, using fewer than half the lines of code.We evaluate the contribution of our optimizations to this success

Estimating malaria parasite density: assumed white blood cell count of 10,000/μl of blood is appropriate measure in Central Ghana.

BACKGROUND: White blood cells count (WBCc) is a bedrock in the estimation of malaria parasite density in malaria field trials, interventions and patient management. White blood cells are indirectly and relatively used in microscopy to estimate the density of malaria parasite infections. Due to frequent lack of facilities in some malaria-endemic countries, in order to quantify WBCc of patients, an assumed WBCc of 8.0 X 10(9)/L has been set by the World Health Organization to help in estimating malaria parasite densities. METHODS: This comparative analysis study, in Central Ghana, compiled laboratory data of 5,902 Plasmodium falciparum malaria parasite positive samples. Samples were obtained from consented participants of age groups less than five years. Full blood counts (FBC) of participants' samples were analysed using the ABX Micros 60 Haematology Analyzer. Blood slides were read by two competent microscopists to produce concordant results. All internal and external quality control measures were carried out appropriately. Parasite densities were calculated using participants' absolute WBCc and assumed WBCc of 5,000 to 10,000 per microlitre of blood. RESULTS: From the 5,902 Pf malaria positive samples, the mean (SD) WBCc and geometric mean parasite density were 10.4 (4.6) × 10(9)/L and 7,557/μL (95% CI 7,144/μL to 7,994/μL) respectively. The difference in the geometric mean parasite densities calculated using absolute WBCs and compared to densities with assumed WBCs counts were significantly lower for 5.0 × 10(9)/L; 3,937/μL, 6.0 × 10(9)/L; 4,725/μL and 8.0 × 10(9)/L; 6,300/μL. However, the difference in geometric mean parasite density, 7,874/μL (95 % CI, 7,445/μL to 8,328/μL), with assumed WBCc of 10.0 × 10(9)/L was not significant. CONCLUSION: Using the assumed WBCc of 8.0 X 10(9)/L or lower to estimate malaria parasite densities in Pf infected children less than five years old could result in significant underestimation of parasite burden. Assumed WBCc of 10.0 × 10(9)/L at 95 % CI of geometric mean of parasite density statistically agreed with the parasite densities produce by the absolute WBCc of participants. The study suggests where resources are limited, use of assumed WBCc of 10.0 × 10(9)/L of blood to estimate malaria parasite density in central Ghana. Preferably, absolute WBCc should be used in drug efficacy and vaccine trials

Helicobacter pylori and cancer among adults in Uganda

Data from Africa on infection with Helicobacter pylori (H. pylori) are sparse. Therefore, as part of an epidemiological study of cancer in Uganda, we investigated the prevalence and determinants of antibodies against H. pylori among 854 people with different cancer types and benign tumours. Patients were recruited from hospitals in Kampala, Uganda, interviewed about various demographic and lifestyle factors and tested for antibodies against H. pylori. In all patients combined, excluding those with stomach cancer (which has been associated with H. pylori infection), the prevalence of antibodies was 87% (723/833) overall, but declined with increasing age (p = 0.02) and was lower among people who were HIV seropositive compared to seronegative (p <0.001). Otherwise, there were few consistent epidemiological associations. Among those with stomach cancer, 18/21 (86%) had anti-H. pylori antibodies (odds ratio 0.8, 95% confidence intervals 0.2–2.9, p = 0.7; estimated using all other patients as controls, with adjustment for age, sex and HIV serostatus). No other cancer site or type was significantly associated with anti-H. pylori antibodies. The prevalence of H. pylori reported here is broadly in accord with results from other developing countries, although the determinants of infection and its' role in the aetiology of gastric cancer in Uganda remain unclear

A cohort study of low birth weight and health outcomes in the first year of life, Ghana.

OBJECTIVE: To investigate the effect of birth weight on infant mortality, illness and care seeking in rural Ghana. METHODS: Using randomized controlled trial data, we compared infants weighing 2.00-2.49, 1.50-1.99 and < 1.50 kg with non-low-birth-weight infants. We generated adjusted mortality hazard ratios (aHR), adjusted illness rate ratios (aRR) and adjusted odds ratios (aOR) for health-facility admissions and absence of care seeking for four time periods: infancy, the neonatal period, early infancy and late infancy - represented by ages of 0-364, 0-27, 28-182 and 183-364 days, respectively. FINDINGS: Among 22 906 infants, compared with non-low-birth-weight infants: (i) infants weighing 2.00-2.49, 1.50-1.99 and < 1.50 kg were about two (aHR: 2.13; 95% confidence interval, CI: 1.76-2.59), eight (aHR: 8.21; 95% CI: 6.26-10.76) and 25 (aHR: 25.38; 95% CI: 18.36-35.10) times more likely to die in infancy, respectively; (ii) those born weighing < 1.50 kg were about 48 (aHR: 48.45; 95% CI: 32.81-71.55) and eight (aHR: 8.42; 95% CI: 3.09-22.92) times more likely to die in the neonatal period and late infancy, respectively; (iii) those born weighing 1.50-1.99 kg (aRR: 1.57; 95% CI: 1.27-1.95) or < 1.50 kg (aRR: 1.58; 95% CI: 1.13-2.21) had higher neonatal illness rates; and (iv) for those born weighing 1.50-1.99 kg, care was less likely to be sought in the neonatal period (aOR: 3.30; 95% CI: 1.98-5.48) and early infancy (aOR : 1.74; 95% CI: 1.26-2.39). CONCLUSION: For low-birth-weight infants in Ghana, strategies to minimize mortality and improve care seeking are needed

The relevance of knowledge, perception, and factors that influence contraceptive use among married women living in Uaddara Barracks, Ghana

Background: Contraceptive use has many advantages for personal growth and societal advancement, but there is still the problem of unmet needs for women, which highlights the gap between women\u27s reproductive intentions and contraceptive use. This study investigated knowledge, perceptions, and factors that influence contraceptive use among married women living in a military base in Ghana. Methods: This cross-sectional study involved 350 married women between the ages of 20 and 58 years at the Uaddara Barracks, Kumasi. A structured questionnaire was used to collect information on the background, knowledge, perceptions on contraceptive use, and contraceptive methods used by participants. Data was entered into an Excel sheet and analysed using R version 4.2.1. Results: Most of the participants were between the age range of 36 and 40 years (25.5%). Almost all study participants (97.4%), had heard about contraceptives with 80.6% showing a high level of knowledge on contraceptives. The majority of the women (84.6%) had previously used some form of contraceptives and 53.1% presently do. More than half of the participants (69.4%) had a positive perception of contraceptive use; 80.6% responded it was their own decision to use contraceptives, and 80.3% had the support of their husbands. Husbands\u27 support of contraception resulted in a 5 times higher usage of contraceptives among women (aOR = 5.35; p \u3c 0.001) while women who were married to military men were 45% (aOR = 0.45; p = 0.007) less likely to use contraceptive when compared to civilian wives. Demographic characteristics like being above 40 years (aOR = 0.25; p = 0.014), being a housewife (aOR = 0.42; p = 0.043) and working in the private sector (aOR = 0.33; p = 0.015) were significantly linked with less contraceptive use. Conclusion: The study showed that women used contraceptives at a rate that was much higher than the national norm at the Uaddara Barracks, demonstrating the beneficial influence men had on women\u27s contraceptive use. This thereby underscores the need for interventional policies that prioritized the male as much as women, while emphasizing the benefits of contraceptive use to the family and not just as an awareness program only

Contraceptive use and associated factors among sexually active female adolescents in Atwima Kwanwoma District, Ashanti region-Ghana

Introduction:&nbsp;unintended pregnancies and adolescent childbearing are on the increase in Sub-Saharan Africa. In Ghana, 14% of adolescents aged 15-19 are already mothers or pregnant with their first child. Most of these pregnancies are associated with poor outcomes such as miscarriages, stillbirths, unsafe abortions and other complications that might result in infant or mortality. In addition, sexually-active adolescents (16-19 years) are at higher risk of contracting STIs. Evidence suggest that contraceptive use help reduce fertility rate and adolescent reproductive health. This study therefore sought to understand the magnitude and associated factors that influence female adolescents' use of contraceptive in the Atwima Kwanwoma District, Ghana. Methods:&nbsp;a descriptive and analytic cross-sectional study design was used for this study. Using a structured questionnaire, data were collected from randomly sampled 200 sexually active female adolescents; aged 16-19 for a three month period; June to September 2017. The questionnaire elicited data on the socio-demographic characteristics of respondents, their knowledge and perception, use of contraceptives and factors influencing their contraceptive use. Data were analyzed using STATA version 12.1 software. Results:&nbsp;ninety-five percent of the respondents exhibited some knowledge about contraceptives, but this high knowledge did not translate into its use as the prevalence rate was 18%. Condom was the most widely used contraceptive (33%) and perceived side effects of contraceptives was found to be the main reason for not using the contraceptives (53.66%). Marital status and the participants who were staying with both parents were found to be associated with contraceptive use with their p-values of 0.023 and 0.002 respectively. Conclusion:&nbsp;considering the fact that contraceptive knowledge does not necessarily translate into use, further studies (qualitative), are needed to understand why high knowledge levels are not associated with high usage patterns

Lateral line ablation by ototoxic compounds results in distinct rheotaxis profiles in larval zebrafish

The zebrafish lateral line is an established model for hair cell organ damage, yet few studies link mechanistic disruptions to changes in biologically relevant behavior. We used larval zebrafish to determine how damage via ototoxic compounds impact rheotaxis. Larvae were treated with CuS

Compiling Tree Transforms to Operate on Packed Representations

When written idiomatically in most programming languages, programs that traverse and construct trees operate over pointer-based data structures, using one heap object per-leaf and per-node. This representation is efficient for random access and shape-changing modifications, but for traversals, such as compiler passes, that process most or all of a tree in bulk, it can be inefficient. In this work we instead compile tree traversals to operate on pointer-free pre-order serializations of trees. On modern architectures such programs often run significantly faster than their pointer-based counterparts, and additionally are directly suited to storage and transmission without requiring marshaling. We present a prototype compiler, Gibbon, that compiles a small first-order, purely functional language sufficient for tree traversals. The compiler transforms this language into intermediate representation with explicit pointers into input and output buffers for packed data. The key compiler technologies include an effect system for capturing traversal behavior, combined with an algorithm to insert destination cursors. We evaluate our compiler on tree transformations over a real-world dataset of source-code syntax trees. For traversals touching the whole tree, such as maps and folds, packed data allows speedups of over 2x compared to a highly-optimized pointer-based baseline

Neonatal vaccination of low birthweight infants in Ghana.

OBJECTIVES: Global vaccination policy advocates for identifying and targeting groups who are underserved by vaccination to increase equity and uptake. We investigated whether birth weight and other factors are determinants of neonatal BCG vaccination in order to identify infants underserved by vaccination. METHODS: We used logistic regression to calculate adjusted ORs (AORs) for the association between birth weight (categorised as non-low birth weight (NLBW) (≥2.50 kg) and low birth weight (LBW) (2-2.49 kg, 1.50-1.99 kg and 0.19). Facility-born infants were vaccinated at a mean of 6 days, suggesting that they were not vaccinated in the facility at birth but were referred for vaccination. CONCLUSIONS: LBW is a risk factor for neonatal under-vaccination, even for facility-born infants. Ensuring vaccination at facility births would substantively improve timing and equitable BCG vaccination