Gravitational microlensing and the search for extrasolar planets

Includes bibliographical references.This project is aimed at tackling binary gravitational microlensing events. Since the early conception of gravitational lensing before Einstein’s General Theory of Relativity, physicists and astronomers of the early 18th century speculated that light, if treated as particle, can be affected by gravitational field. Gravitational Microlensing is defined as a phenomenon occurring when light coming from a distant (source) star is bent by the gravitational field of an intervening mass (lens) creating multiple image of the source which cannot be resolved. In this project, We applied a model for binary lens microlensing events. We analysed data obtained from different observatories: PLAXET, which includes SAAO, Sutherland, Canopus and Perth observatories, OGLE, Danish Telescope, LaSilla. For the observed microlensing target OGLE-2011-BLG-265, analysis of the data using the program supplied by Keith Horne, using different minimization schemes and algorithms, I found best fit model to be a binary lens with mass ratio q = 0.0042 and separation of components is found to be u = 1.034 where in this case the separation falls under an intermediate binary lens topology. Finally, the deviation from the point-source point-lens microlensing events on the light curve and small mass ratio suggested a planetary system. I also calculated the time, tp, that the source needs to cross the diameter of the planet Einstein Ring radius, which is related to the mass ratio, and is found to be 3.30 days

Prevalence and factors affecting use of long acting and permanent contraceptive methods in Jinka town, Southern Ethiopia: a cross sectional study

Introduction: In Ethiopia, knowledge of contraceptive methods is high though there is low contraceptive prevalence rate. This study was aimed to assess prevalence and associated factors of long acting and permanent contraceptive methods in Jinka town, southern Ethiopia. Methods: Community based cross sectional survey was conducted to assess the prevalence and factors affecting long acting and permanent methods of contraceptives utilization from March to April 2008. Eight hundred child bearing age women were participated in the quantitative study and 32 purposively selected focus group discussants were participated in the qualitative study. Face to face interview was used for data collection. Data were analyzed by SPSS version 13.0 statistical software. Descriptive statistics and logistic regression were computed to analyze the data. Results: The prevalence of long acting and permanent contraceptive method was 7.3%. Three fourth  (76.1%) of the women have ever heard about implants and implant 28 (50%) were the most widely used method. Almost two third of women had intention to use long acting and permanent methods. Knowledge of contraceptive and age of women have significant association with the use of long acting and permanent contraceptive methods.Conclusion: The overall prevalence of long acting and permanent contraceptive method was low.  Knowledge of contraceptive and age of women have significant association with use of long acting and permanent contraceptive. Extensive health information should be provided.Key words: Long acting, permanent, contraceptive, women, Ethiopi

Perception of fertility regulation in a remote community, South Ethiopia

Abstract: This exploratory study was conducted to describe the traditional methods of contraception and community perception of fertility regulation in a remote rural community of Ethiopia. In-depth interviews were conducted with "key informants" selected from the rural communities of Bensa district, South Ethiopia. Selection of key informants was purposive with the aim of obtaining knowledgeable and articulate individuals. Four categories of individuals were interviewed: elderly men, elderly women, women in reproductive age, and community health workers. The findings are described in three categories: contraception methods, sexual norms and premarital sex, and desired family size. The results showed that, in Bensa Community, postpartum sexual abstinence and prolonged breast-feeding are the main means of fertility regulation. Cultural values regarding sex(postpartum and premarital abstinences) are being disregarded now adays. On the other hand, the effects of unregulated fertility on population growth and societal resources are well perceived by the community. The community expressed willingness to accept modern family planning methods to regulate fertility. Further studies, however, are recommended for a better understanding of the issues using a mixture of quantitative and qualitative research methods. [Ethiop. J. Health Dev. 1999;13(3):217-221

Brain magnetic resonance imaging findings in patients with developmental delay in Addis Ababa, Ethiopia

BACKGROUND: Developmental delay is a major health problem throughout the world causing significant individual disability. Even though physical examination and patient history are the most important and basic evaluations of patients with developmental delay, additional investigations are usually required in supporting or reaching a diagnosis among which is neuroimaging. This study aims to assess brain Magnetic resonance imaging (MRI) patterns in patients presented with developmental delay.METHOD: A retrospective analysis of 164 patients who had undergone brain Magnetic Resonance Imaging (MRI) evaluation for the developmental delay was done. The study was conducted between March to November 2021 G.C at Tikur Anbessa Specialized Hospital (TASH). The patients’ clinical history and magnetic resonance imaging reports were reviewed from their medical records. All patients with developmental delay who had brain MRI evaluation at TASH and at one private diagnostic center in Addis Ababa were included in the study.RESULTS: A total of 164 patients were included in this study of which 95(57.9%) were male and 69(42.1%) female patients were seen. A total of 120 patients (73.2%) showed abnormal brain MRI studies. Previous neurovascular insults were the most common abnormalities seen in 75(45.7%) patients followed by imaging findings of congenital and developmental abnormalities seen in 20(12.2%) patients.CONCLUSION: Brain MRI is an important input in the evaluation of patients with developmental delay. It can give evidence for the cause of developmental delay, especially in the diagnosis of perinatal/hypoxic-ischemic insults, and congenital and developmental malformations

Assessment of efficacy and quality of two albendazole brands commonly used against soil-transmitted helminth infections in school children in Jimma Town, Ethiopia

Background : There is a worldwide upscale in mass drug administration (MDA) programs to control the morbidity caused by soil-transmitted helminths (STHs): Ascaris lumbricoides, Trichuris trichiura and hookworm. Although anthelminthic drugs which are used for MDA are supplied by two pharmaceutical companies through donation, there is a wide range of brands available on local markets for which the efficacy against STHs and quality remain poorly explored. In the present study, we evaluated the drug efficacy and quality of two albendazole brands (Bendex and Ovis) available on the local market in Ethiopia. Methodology/Principal Findings : A randomized clinical trial was conducted according to the World Health Organization (WHO) guidelines to assess drug efficacy, by means of egg reduction rate (ERR), of Bendex and Ovis against STH infections in school children in Jimma, Ethiopia. In addition, the chemical and physicochemical quality of the drugs was assessed according to the United States and European Pharmacopoeia, encompassing mass uniformity of the tablets, amount of active compound and dissolution profile. Both drugs were highly efficacious against A. lumbricoides (>97%), but showed poor efficacy against T. trichiura (similar to 20%). For hookworms, Ovis was significantly (p < 0.05) more efficacious compared to Bendex (98.1% vs. 88.7%). Assessment of the physicochemical quality of the drugs revealed a significant difference in dissolution profile, with Bendex having a slower dissolution than Ovis. Conclusion/Significance : The study revealed that differences in efficacy between the two brands of albendazole (ABZ) tablets against hookworm are linked to the differences in the in-vitro drug release profile. Differences in uptake and metabolism of this benzimidazole drug among different helminth species may explain that this efficacy difference was only observed in hookworms and not in the two other species. The results of the present study underscore the importance of assessing the chemical and physicochemical quality of drugs before conducting efficacy assessment in any clinical trials to ensure appropriate therapeutic efficacy and to exclude poor drug quality as a factor of reduced drug efficacy other than anthelminthic resistance. Overall, this paper demonstrates that "all medicines are not created equal"

Neglected Tropical Diseases (NTD) service availability at health facilities in Ethiopia: Evidence from 2014 Ethiopian service provision assessment

Background: Neglected tropical diseases (NTDs) are a group of infections which are especially endemic in low-income populations in developing regions of Africa, Asia, and the Americas. In sub-Saharan Africa, the impact of these diseases as a group is comparable to malaria and tuberculosis. The diseases recognized as neglected tropical diseases by the World Health Organization (WHO) are: Chagas disease, Cysticercosis and taeniasis, Dengue fever, Dracunculiasis, Echinococcosis, Human African trypanosomiasis, Leishmaniasis, Leprosy, Lymphatic filariasis, Onchocerciasis, Rabies, Schistosomiasis, Soil-transmitted helminthiasis, Trachoma, and Yaws. Most of these diseases are either preventable through mass drug administration (MDA) and proper hygiene and sanitation, or treatable through systematic case finding and management. This study was conducted with the aim of assessing the availability of services for neglected tropical diseases management at health facilities in Ethiopia.Method: The assessment is part of the 2014 Ethiopian Service Provision Assessment Plus (ESPA+) Survey. A total of 873 health facilities were assessed for this analysis. All Hospitals, selected health centre, and private clinics were assessed if they provide services for Neglected Tropical Diseases.Result: More than half of all health facilities offer services for both soil transmitted helminthes (64 percent), and services for trachoma (60 percent). About four of every ten health facilities offer services for schistosomiasis. On the other hand, services for onchocerciasis, leishmanianis and lymphatic filariases were available in less than a third of all health facilities (27%, 25% and 24%, respectively).Conclusion and recommendation: Even though, the availability of service for neglected tropical disease in health facilities is relatively good in general, there should be equitable distribution of neglected tropical disease service provision among regions. And private facilities should give emphasis for the provision of these services. Key words: Service Availability, NTDs, SPA+, Ethiopia

Magnitude, risk factors and outcomes of stroke at Debre Markos Referral Hospital, Northwest Ethiopia:a retrospective observational study

Background: Stroke is one of the leading causes of death and disability in developing countries. The burden of stroke has varied widely in different areas, and there is a paucity of information about stroke in the selected study area. Objectives: To assess the burden, risk factors, and outcomes of stroke at Debre Markos Referral Hospital, Northwest Ethiopia Patients and methods: A hospital-based retrospective observational study was conducted in the medical ward of Debre Markos Referral Hospital from March 2017 to April 2019. A pretested checklist was used to extract relevant data from the chart of stroke patients. All statistical analyses were performed in the SPSS version 20 software. Results: From a total of 2100 admissions in the medical ward, 162 of them were stroke patients, giving the in-hospital magnitude of 7.7%. The in-hospital case fatality rate was 8.6%. Additionally, 27.2% of patients were improved and 39.5% of them were referred. There was a significant association between types of stroke and risk factors such as sex, comorbid hypertension, hyperlipidemia, and atrial fibrillation (P ≤ 0.05). Conclusion: The in-hospital period prevalence of stroke was 7.7%. Ischemic stroke was the most common type of stroke. Hypertension and hyperlipidemia were the leading identified risk factors for stroke. The overall in-hospital mortality was lower than previous studies in sub-Saharan African countries. Therefore, effective strategies and guidelines for the prevention and control of stroke and its risk factors are needed

Association between a complex community intervention and quality of health extension workers' performance to correctly classify common childhood illnesses in four regions of Ethiopia.

BACKGROUND: Due to low care utilization, a complex intervention was done for two years to optimize the Ethiopian Health Extension Program. Improved quality of the integrated community case management services was an intermediate outcome of this intervention through community education and mobilization, capacity building of health workers, and strengthening of district ownership and accountability of sick child services. We evaluated the association between the intervention and the health extension workers' ability to correctly classify common childhood illnesses in four regions of Ethiopia. METHODS: Baseline and endline assessments were done in 2016 and 2018 in intervention and comparison areas in four regions of Ethiopia. Ill children aged 2 to 59 months were mobilized to visit health posts for an assessment that was followed by re-examination. We analyzed sensitivity, specificity, and difference-in-difference of correct classification with multilevel mixed logistic regression in intervention and comparison areas at baseline and endline. RESULTS: Health extensions workers' consultations with ill children were observed in intervention (n = 710) and comparison areas (n = 615). At baseline, re-examination of the children showed that in intervention areas, health extension workers' sensitivity for fever or malaria was 54%, 68% for respiratory infections, 90% for diarrheal diseases, and 34% for malnutrition. At endline, it was 40% for fever or malaria, 49% for respiratory infections, 85% for diarrheal diseases, and 48% for malnutrition. Specificity was higher (89-100%) for all childhood illnesses. Difference-in-differences was 6% for correct classification of fever or malaria [aOR = 1.45 95% CI: 0.81-2.60], 4% for respiratory tract infection [aOR = 1.49 95% CI: 0.81-2.74], and 5% for diarrheal diseases [aOR = 1.74 95% CI: 0.77-3.92]. CONCLUSION: This study revealed that the Optimization of Health Extension Program intervention, which included training, supportive supervision, and performance reviews of health extension workers, was not associated with an improved classification of childhood illnesses by these Ethiopian primary health care workers. TRIAL REGISTRATION: ISRCTN12040912, http://www.isrctn.com/ISRCTN12040912