292 research outputs found

    Reducing microscopy-based malaria misdiagnosis in a low-resource area of Tanzania

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    Misdiagnosis of malaria is a major problem in Africa leading not only to incorrect individual level treatment, but potentially the acceleration of the spread of drug resistance in low-transmission areas. In this paper we report on the outcomes of a simple intervention that utilized a social entrepreneurship approach (SEA) to reduce misdiagnosis associated with hospital-based microscopy of malaria in a low-transmission area of rural Tanzania. A pre-post assessment was conducted on patients presenting to the hospital outpatient department with malaria and non-malaria like symptoms in January 2009 (pre-intervention) and June 2009 (post-intervention). All participants were asked a health seeking behavior questionnaire and blood samples were taken for local and quality control microscopy. Multivariate logistic regression was conducted to determine magnitude of misdiagnosis with local microscopy pre- versus- post intervention. Local microscopy pre-intervention specificity was 29.5% (95% CI = 21.6% – 38.4%) whereas the post intervention specificity was 68.6% (95% CI = 60.2% - 76.2%). Both pre and post intervention sensitivity were difficult to determine due to an unexpected low number of true positive cases. The proportion of participants misdiagnosed pre-intervention was 70.2% (95%CI = 61.3%-78.0%) as compared to 30.6% (95%CI = 23.2%–38.8%) post-intervention. This resulted in a 39.6% reduction in misdiagnosis of malaria at the local hospital. The magnitude of misdiagnosis for the pre-intervention participants was 5.3 (95%CI = 3.1–9.3) that of the post-intervention participants. In conclusion, this study provides evidence that a simple intervention can meaningfully reduce the magnitude of microscopy-based misdiagnosis of malaria for those individuals seeking treatment for uncomplicated malaria. We anticipate that this intervention will facilitate a valuable and sustainable change in malaria diagnosis at the local hospital

    Self-repair ability of evolved self-assembling systems in cellular automata

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    Self-repairing systems are those that are able to reconfigure themselves following disruptions to bring them back into a defined normal state. In this paper we explore the self-repair ability of some cellular automata-like systems, which differ from classical cellular automata by the introduction of a local diffusion process inspired by chemical signalling processes in biological development. The update rules in these systems are evolved using genetic programming to self-assemble towards a target pattern. In particular, we demonstrate that once the update rules have been evolved for self-assembly, many of those update rules also provide a self-repair ability without any additional evolutionary process aimed specifically at self-repair

    Infrastructure and Foreign Direct Investment Inflows in South Africa: An Engle-Granger Error Correction Model Approach

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    The aim of this study was to examine the impacts of infrastructure quality and infrastructure investment on foreign direct investment in South Africa over the period 1970-2015. Time series annual data on foreign direct investment, infrastructure quality, infrastructure investment, financial market development, market size, macroeconomic stability and trade openness indicators were collected from relevant sources. Unit root tests were done using Augmented Dickey-Fuller and Phillips Perron methods, while cointegration was tested using the Johansen cointegration approach. The Engle-Granger error correction model was used to compute long-run and short-run estimates of the model. Results of the first step long-run segment show that trade openness, market size and infrastructure quality had statistically significant and positive impacts on FDI inflows. Macroeconomic stability had a significant and negative impact on FDI inflows, while financial market development and infrastructure investment had insignificant and negative impacts on FDI inflows. In the short run, the error correction term shows that 50.7% of disequilibrium in FDI inflows was corrected within a period of one year. Market size, macroeconomic stability and infrastructure investment had statistically significant and negative impacts on FDI inflows into South Africa over the sample period under review. Infrastructure quality, financial development and trade openness had positive but insignificant impacts on FDI inflows into the country. The estimated model passed all the diagnostic and stability tests. Keywords: Foreign direct investment (FDI) inflows, infrastructure quantity, infrastructure quality, Engle-Granger Error Correction Model DOI: 10.7176/JESD/12-12-02 Publication date:June 30th 202

    Foreign Direct Investment and Economic Growth in South Africa: A Vector Error Correction (VEC) Model Approach

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    The objective of this research study was to examine the influence of foreign direct investment on economic growth in South Africa during the period 1994-2014. Time series annual data on real gross domestic product (GDP) growth, foreign direct investment, and terms of trade were sourced from the South African Reserve Bank (SARB) historical macroeconomic statistics online database. Unit root and cointegration properties of data were analysed using Augmented Dickey-Fuller and Johansen cointegration test techniques, respectively. The Vector Error Correction model was applied to compute long-run and short-run parameters of endogenous variables in the model. Results of the long-run section of the cointegrating equation show that for every 1 percent rise in foreign direct investment, there was a statistically significant rise in growth of gross domestic product by about 0.05 percentage points during the period 1994-2014. Results of the error correction component of the gross domestic product growth equation show that about 62 percent of the deviance from the long-run stability pathway was rectified in the first year after the deviation occurred. Results of the impulse response functions indicate that a one standard deviation in foreign direct investment had a statistically significant and positive effect on future gross domestic product growth after the first year. Keywords: Foreign direct investment (FDI), gross domestic product (GDP) growth, Vector Error Correction (VEC) model DOI: 10.7176/JESD/12-12-01 Publication date:June 30th 202

    NiO Nanofibers as a Candidate for a Nanophotocathode

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    p-type NiO nanofibers have been synthesized from a simple electrospinning and sintering procedure. For the first time, p-type nanofibers have been electrospun onto a conductive fluorine doped tin oxide (FTO) surface. The properties of the NiO nanofibers have been directly compared to that of bulk NiO nanopowder. We have observed a p-type photocurrent for a NiO photocathode fabricated on an FTO substrate

    Genomic and proteomic : clinical interest

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    Pathological Features of Breast Cancer seen in Northwestern Tanzania: A Nine Years Retrospective Study.

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    Breast cancer is more common in Western Countries compared to African populations. However in African population, it appears that the disease tends to be more aggressive and occurring at a relatively young age at the time of presentation. The aim of this study was to describe the trend of Breast Cancer in Northwestern Tanzania. This was a retrospective study which involved all cases of breast cancer diagnosed histologically at Bugando Medical Center from 2002 to 2010. Histological results and slides were retrieved from the records in the Pathology department, clinical information and demographic data for patients were retrieved from surgical wards and department of medical records. Histology slides were re-evaluated for the histological type, grade (By modified Bloom-Richardson score), and presence of necrosis and skin involvement. Data was entered and analyzed by SPSS computer software version 15. There were 328 patients histologically confirmed to have breast cancer, the mean age at diagnosis was 48.7 years (+/- 13.1). About half of the patients (52.4%) were below 46 years of age, and this group of patients had significantly higher tendency for lymph node metastasis (p = 0.012). The tumor size ranged from 1 cm to 18 cm in diameter with average (mean) of 5.5 cm (+/- 2.5), and median size of 6 cm. Size of the tumor (above 6 cm in diameter) and presence of necrosis within the tumor was significantly associated with high rate of lymph node metastasis (p = 0.000). Of all patients, 64% were at clinical stage III (specifically IIIB) and 70.4% had lymph node metastasis at the time of diagnosis. Only 4.3% of the patients were in clinical stage I at the time of diagnosis. Majority of the patients had invasive ductal carcinoma (91.5%) followed by mucinous carcinoma (5.2%), Invasive lobular carcinoma (3%) and in situ ductal carcinoma (0.3%). In all patients, 185 (56.4%) had tumor with histological grade 3. Breast cancer in this region show a trend towards relative young age at diagnosis with advanced stage at diagnosis and high rate of lymph node metastasis. Poor Referral system, lack of screening programs and natural aggressive biological behavior of tumor may contribute to advanced disease at the time of diagnosis

    Preferences and priorities for relapsed multiple myeloma treatments among patients and caregivers in the United States

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    Introduction/Background: This study aimed to describe patient and caregiver preferences for treatments of relapsed or refractory multiple myeloma (MM). Materials and Methods: A survey including discrete-choice experiment (DCE) and best-worst scaling (BWS) exercises was conducted among US patients with relapsed or refractory MM and their caregivers. The DCE included six attributes with varying levels including progression-free survival (PFS), toxicity, and mode and frequency of administration. In addition, the impact of treatment cost was assessed using a fixed-choice question. The BWS exercise included 18 items (modes and frequency of administration, additional treatment convenience, and toxicity items). The survey was administered online to patients recruited from the Multiple Myeloma Research Foundation CoMMpass study (NCT01454297). Results: The final samples consisted of 94 patients and 32 caregivers. Avoiding severe nerve damage was most important to patients, followed by longer PFS. Caregivers considered PFS to be the most important attribute. We estimate that a third or more of patients were cost-sensitive, meaning their treatment preference was altered based on cost implications. Caregivers were not cost-sensitive. The three most bothersome treatment features in the BWS exercise were risk of kidney failure, lowering white blood cell counts, and weakening the immune system. Conclusion: Patients with relapsed or refractory MM and their caregivers consider many factors including efficacy, toxicity, mode/frequency of administration, and cost in their decisions regarding treatment options. The study provides a basis for future Research on patient and caregiver treatment preferences, which could be incorporated into shared decision-making with physicians

    POEtic Tissue: An Integrated Architecture for Bio-inspired Hardware

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    It is clear to all, after a moments thought, that nature has much wemight be inspired by when designing our systems, for example: robustness, adaptability and complexity, to name a few. The implementation of bio-inspired systems in hardware has however been limited, and more often than not been more a matter of artistry than engineering. The reasons for this are many, but one of the main problems has always been the lack of a universal platform, and of a proper methodology for the implementation of such systems. The ideas presented in this paper are early results of a new research project, "Reconfigurable POEtic Tissue". The goal of the project is the development of a hardware platform capable of implementing systems inspired by all three major axes (phylogenesis, ontogenesis, and epigenesis) of bio-inspiration, in digital hardware
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