An MPI-based 2D data redistribution library for dense arrays

In HPC, data redistributions (reorganizations) are used in parallel applications to improve performance and/or provide data-locality compatibility with sequences of parallel operations. Data reorganization refers to changing the logical and physical arrangement of data (such as dense arrays or matrices distributed over peer processes in a parallel program). This operation can be achieved by applying transformations such as transpositions or rotations or changing how data is mapped across the process grid P by Q, all of which are accomplished either with message passing or distributed shared memory operations. In this project, we restrict ourselves to a distributed memory model and message passing, not a shared-memory model, nor do we use distributed shared memory APIs. Our primary goal is to generate a library capable of diverse data reorganizations. We aim to develop a high-level Application Programming Interface (API) that directly works with the Message Passing Interface (MPI) to accomplish data redistributions in data-parallel applications and libraries, such as the polymath library, a library of many algorithms all of which implement parallel dense matrix multiplication algorithms with flexible data layouts. Using the reorganization mode of process grid shapes with constant total processes, we plan to observe the performance trends of the polymath dense parallel matrix-multiplication library (which is related research) based on different grid shapes, problem sizes, numbers of processes and decide whether it is more efficient to redistribute data or not to achieve the highest performance. We will test other redistributions for some of the process shapes used with the polymath library to identify how redistribution impacts performance. These tests will provide us with the information to determine if redistribution is worthwhile for non-optimal process layout (as established with the polymath system). Besides changing the shape of the data in terms of its layout on a logical process topology, we also plan to study and demonstrate data transpose algorithms in this library, another useful redistribution mechanism for dense linear algebra in distributed-memory parallel computing

Collective-Optimized FFTs

This paper measures the impact of the various alltoallv methods. Results are analyzed within Beatnik, a Z-model solver that is bottlenecked by HeFFTe and representative of applications that rely on FFTs

Willingness by people living with HIV/AIDS to utilize HIV services provided by Village Health team workers in Kalungu district, central Uganda.

BACKGROUND: Less than one quarter of people in need have access to HIV services in Uganda. This study assessed willingness of people living with HIV/AIDS (PLWHAs) to utilize HIV services provided by Village Health Teams (VHTs) in Kalungu district, central Uganda. METHODS: A cross-sectional study conducted in two health facilities providing anti-retroviral therapy enrolled 312 PLWHAs. Pre-tested semi-structured questionnaires were administered to participants at household level. A forward fitting logistic regression model computed the predictors of willingness of PLWHAs to utilize services provided by VHTs. RESULTS: Overall, 49% were willing to utilize HIV services provided by VHTs increasing to 75.6% if the VHT member was HIV positive. PLWHAs who resided in urban areas were more likely to utilize HIV services provided by VHTs (AOR 0.24, 95%CI 0.06-0.87). Barriers to utilizing HIV services provided by VHTs were: income level > 40 USD (AOR 6.43 95%CI 1.19-34.68), being a business person (AOR 8.71 95%CI 1.23-61.72), peasant (AOR 7.95 95%CI 1.37-46.19), lack of encouragement from: peers (AOR 6.33 95%CI 1.43-28.09), spouses (AOR 4.93 95%CI 1.23-19.82) and community leader (AOR 9.67 95%CI 3.35-27.92). CONCLUSION: Social support could improve willingness by PLWHAs to utilize HIV services provided by VHTs for increased access to HIV services by PLWHA

Willingness by people living with HIV/AIDS to utilize HIV services provided by Village Health team workers in Kalungu district, central Uganda

Background: Less than one quarter of people in need have access to HIV services in Uganda. This study assessed willingness of people living with HIV/AIDS (PLWHAs) to utilize HIV services provided by Village Health Teams (VHTs) in Kalungu district, central Uganda. Methods: A cross-sectional study conducted in two health facilities providing anti-retroviral therapy enrolled 312 PLWHAs. Pre-tested semi-structured questionnaires were administered to participants at household level. A forward fitting logistic regression model computed the predictors of willingness of PLWHAs to utilize services provided by VHTs. Results: Overall, 49% were willing to utilize HIV services provided by VHTs increasing to 75.6% if the VHT member was HIV positive. PLWHAs who resided in urban areas were more likely to utilize HIV services provided by VHTs (AOR 0.24, 95%CI 0.06-0.87). Barriers to utilizing HIV services provided by VHTs were: income level > 40 USD (AOR 6.43 95%CI 1.19-34.68), being a business person (AOR 8.71 95%CI 1.23-61.72), peasant (AOR 7.95 95%CI 1.37-46.19), lack of encouragement from: peers (AOR 6.33 95%CI 1.43-28.09), spouses (AOR 4.93 95%CI 1.23-19.82) and community leader (AOR 9.67 95%CI 3.35-27.92). Conclusion: Social support could improve willingness by PLWHAs to utilize HIV services provided by VHTs for increased access to HIV services by PLWHA

Response of Common Bean Genotypes Grown in Soil with Normal or Limited Moisture, with Special Reference to the Nutrient Phosphorus

Drought and phosphorus deficiency in the soil are the major production limitations of common beans (Phaseolus vulgaris L.) in Sub-Saharan Africa. This study measured the yield responses of low phosphorus-tolerant common beans to drought stress. A field experiment was conducted under two drought conditions codenamed, non-drought-stress (NDS) and drought-stress (DS). The former was located at Mukono Zonal Agricultural Research and Development Institute (MUZARDI) in Mukono District, characterised by rainfall of more than 400 mm season−1. The latter was situated at Wabinyonyi in Nakasongola District, characterised by less than 300 mm season−1; both in central Uganda. Treatments included the two study conditions (NDS and DS); and four test bean genotypes, AFR703-1, AFR 708, JESCA, and MCM 2001, against a local check, K131. A water deficit of 156 mm season−1 was observed in the DS site causing a drought intensity index (DII) of 40%. That pattern contrasted considerably in the NDS site where the actual rainfall did not significantly (p > 0.05) vary from the required water by the bean plant. Whereas genotypes AFR703-1 and AFR708 out-yielded the local check in NDS by 213 and 681 kg ha−1, respectively; their grain yield harvested was comparable to the control yield in DS. When grown under DS, low P-tolerant beans, especially the AFR703-1 and AFR708, survived drought stress through faster development by reducing the number of days to flower, reach physiological maturity and develop seeds. AFR703-1 and AFR708 sufficiently withstand drought stress, and are therefore recommended for inclusion in cropping systems that are characteristically constrained by the combined soils’ P deficiency and/or drought

Conservation Farming and Changing Climate: More Beneficial than Conventional Methods for Degraded Ugandan Soils

The extent of land affected by degradation in Uganda ranges from 20% in relatively flat and vegetation-covered areas to 90% in the eastern and southwestern highlands. Land degradation has adversely affected smallholder agro-ecosystems including direct damage and loss of critical ecosystem services such as agricultural land/soil and biodiversity. This study evaluated the extent of bare grounds in Nakasongola, one of the districts in the Cattle Corridor of Uganda and the yield responses of maize (Zea mays) and common bean (Phaseolus vulgaris L.) to different tillage methods in the district. Bare ground was determined by a supervised multi-band satellite image classification using the Maximum Likelihood Classifier (MLC). Field trials on maize and bean grain yield responses to tillage practices used a randomized complete block design with three replications, evaluating conventional farmer practice (CFP); permanent planting basins (PPB); and rip lines, with or without fertilizer in maize and bean rotations. Bare ground coverage in the Nakasongola District was 187 km2 (11%) of the 1741 km2 of arable land due to extreme cases of soil compaction. All practices, whether conventional or the newly introduced conservation farming practices in combination with fertilizer increased bean and maize grain yields, albeit with minimal statistical significance in some cases. The newly introduced conservation farming tillage practices increased the bean grain yield relative to conventional practices by 41% in PPBs and 43% in rip lines. In maize, the newly introduced conservation farming tillage practices increased the grain yield by 78% on average, relative to conventional practices. Apparently, conservation farming tillage methods proved beneficial relative to conventional methods on degraded soils, with the short-term benefit of increasing land productivity leading to better harvests and food security