The structure of thin accretion discs around magnetised stars

Aims: We determine the steady-state of an axisymmetric thin accretion disc with an internal dynamo around a magnetised star. Methods: Starting from the vertically integrated equations of magnetohydrodynamics we derive a single ordinary differential equation for a thin accretion disc around a massive magnetic dipole and integrate this equation numerically from the outside inwards. Results: Our numerical solution shows that the torque between the star and the accretion disc is dominated by the contribution from the dynamo in the disc. The location of the inner edge of the accretion disc varies between $R_{\rm A}$ and $10R_{\rm A}$ depending mainly on the strength and direction of the magnetic field generated by the dynamo in the discComment: 9 pages, 10 figures. The paper is accepted for publication in Astronomy & Astrophysic

Rangeland dynamics in South Omo Zone of Southern Ethiopia: Assessment of rangeland condition in relation to altitude and Grazing types

A study was undertaken in Hamer and Benna-Tsemay districts of the Southern Ethiopia with the objective to determine the condition of the rangelands for grazing animals as influenced by altitude and grazing types. The rangelands in each of the study districts were stratified based on altitude and grazing types. In the study districts, a total of 32, 3, 2, 7 and 29 species of grasses, legumes, sedges, other herbaceous plants and woody species were identified, respectively. The common and/or dominant grass species in the enclosures was Cenchrus ciliaris while in the communal grazing areas they were Cynodon dactylon and Tetrapogon tennulis. In riverside grazing areas, the common and/or dominant grass species was Cynodon dactylon. The total grass biomass of communal, riverside and enclosure areas found in the different altitude categories of the study districts ranged from 398-503; 98-626, and 1,132 – 1,209 kg/ha, respectively. The common and/or dominant woody species in the communal grazing areas were highly palatable species of Acacia tortilis and Grewia bicolor and less palatable Solanum species. In riverside grazing areas, the common and/or dominant woody plants were species of Acacia tortilis, Grewia bicolor, and Solanum species while in the enclosures; Acacia brevispica and Acacia tortilis were found. The woody vegetation density per hectare of communal, riverside and enclosure areas in the different altitude categories of the study districts ranged from 2,501-3,021; 2251-3,021, and 201-700,wd/ha respectively which showed that the communal and riverside grazing areas were bush encroached. The range condition scores ranged from 17.87-20.38 (communal), 22-27 (riverside), 31.05-31.2 (enclosures) which were poor, fair and good condition classes, respectively. Similarly, with regard to the same variable the scored varied from 22-32.87, 19.73-31.43, 17.97-31.44 and 17.87-31.28% in altitudes >1550m, 1250-1550m, 900-1250m, and 550-900m, respectively. The result indicated the need for rangeland improvement measures in communal and riverside grazing areas, in order to attain sustainable livestock production from these areas. Establishment of community based enclosures was found to be one of the ways to improve the condition of the rangelands. The result indicated the need for rangeland improvement measures in communal and riverside grazing areas, in order to attain sustainable livestock production from these areas. Establishment of community based enclosures was found to be one of the ways to improve the condition of the rangeland

Breast Cancer in an Ethiopian Population, Addis Ababa

Background: Breast cancer is a major life-threatening public health problem of great concern. Long-term increases in the incidence of the disease are being observed in both industrialized and developing world.Methods: During 1995-99, 137 biopsy proven breast cancer cases underwent surgical treatment at Tikur Anbessa Hospital, Addis Ababa. Of these cases, records of 125 were retrieved and analyzed to assess the pattern and treatment outcome of the disease.Results: The median age of females was 40 years. The median duration of the presenting symptom on admission was nearly 1 year. Clinically, majority of cases had stage III disease. Invasive ductal carcinoma was the most frequent type. Eighty-nine (71.2%) patients underwent modified radical mastectomy. During a short follow-up, 50 (45.9%) of 109 patients were seen with recurrences. Only 4 cases were seen at 5 or more years.Conclusion: In our series, breast cancer affected mainly young women; patients presented excessively late a probable contributor to the high rate of early relapse. Follow-up was poor. Public education on the importance of regular self breast examination to detect breast cancer should be emphasized

Cactus Potential in Heavy Metal (Pb and Cd) Removal in Water Sample Collected from Rural Area around Adigrat Town

The main objective of this study is to investigate the heavy metals (Pb and Cd) removal capability of cactus powder from water sample using FAAS adsorption techniques by considering the influence of contact time, adsorbent dose and temperature on adsorption of Pb and Cd ions by cactus powder. The results revealed that adsorption of Pb and Cd ions increased as the dose of adsorbent increased at a certain limits. The heavy metal removal capability of cactus powder is affected by the present of NaCl salt. The heavy metal removal capability of cactus powder decreased from 65% up to 7% for Pb, and from 70% up to 14% for Cd as the dose of NaCl increased from 1g to 5g. The decrement in the removal of both Pb and Cd ions from water sample with increasing of NaCl is due to the formation of outer sphere complex with the NaCl salt which screening the functional group of cactus powder from heavy metals. The heavy metal removal capability of cactus powder also increased with contact time. The adsorption rate initially increased from 20% to 58 % for Pb ion, and 17% to 43% for Cd ion when the contact time increased from 30-120 min.  After 120 min there was no significant change in heavy metal removal of both Pb and Cd ions.  This might be due to end point at which adsorption phase reached to equilibrium. The percentage removal of Pb by cactus powder decreased from 65.05% to 29% as the temperature increased from 25 oC to150 oC.  In similar condition, the percentage removal of Cd by cactus powder also decreased from 43% to 31% as the temperature increased from 25 oC to150 oC.  This decrement in percentage removal of both Pb and Cd ions with increase temperature is due to the weak binding interaction between the active site of cactus powder and (Pb, Cd) ions which support physicosorption process. Keywords: Cactus Powder, Heavy Metal, Adsorbent, Adsorbate, Dose, Heavy Metal Removal and Active Site

Assessment of Antidiabetic Medication Adherence and Its Determinants among Ambulatory Patients with Type 2 Diabetes at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia

Poor adherence to treatment of chronic diseases is a worldwide problem of striking magnitude. Adherence to long-term therapy for chronic illnesses in developed countries averages 50%. Poor adherence to recognized standards of diabetes care is the principal cause of development of complications of diabetes and their associated individual, societal and economic costs. Information on adherence to antidiabetic medications among Type 2 diabetes patients in Ethiopia is scanty. This study therefore sought to assess antidiabetic medication adherence and its determinants among 322 ambulatory patients with Type 2 diabetes mellitus attending the diabetic clinic of Tikur Anbessa Specialized Hospital (TASH). It was a cross-sectional study conducted from 1 May-30 June 2014. Assessment of adherence was performed based on patients’ response to the validated four-item Morisky instrument. Adherence rate to antidiabetic medications was found to be 66.8%. Younger age, increased number of prescribed medications and job type (being a farmer/daily laborer) were significantly associated with antidiabetic medication non-adherence. Most of the patients missed their medications because of forgetfulness. Taken together, the findings indicated that adherence to antidiabetic drugs was suboptimal which warrants the need for health care providers engaged in diabetic care to aggressively address the issue. Keywords: TASH, Antidiabetic Medication Adherence, Type 2 Diabetes, Morisky Instrumen

Rickettsial Zoonosis with Particular Reference to Scrub Typhus: A Review Paper

Rickettsiae comprise a group of microorganisms that phylogenetically occupy a position between bacteria and viruses. They are obligate intracellular gram-negative coccobacillary forms that multiply within eukaryotic cells. A general characteristic of rickettsiae is that mammals and arthropods are natural hosts. Scrub typhus is zoonotic rickettsiosis transmitted to humans through the bite of thrombiculid mites. Orientia tsutsugamushi is the causative agent for scrub typhus and humans are accidental hosts and become infected when they are bitten by chiggers infected with the agent. The agent multiply at the inoculation site with the formation of a papule that ulcerates and becomes necrotic, evolving into an eschar, with regional lymphadenopathy that progress to generalized lymphadenopathy within a few days. Scrub typhus may be diagnosed in the laboratory by isolation of the organism; serology and molecular diagnosis (PCR). Tetracycline and Chloramphenicol are proven therapy for the rickettsial diseases. The disease can be prevented by the use of personal protective measures including repellents, people entering an exposed area should wear closed in footwear such as boots with socks, and long trousers. Keywords: Rickettsiae, Scrub typhu

The determinants of agricultural productivity and rural household income in Ethiopia

This paper aims at investigating the determinants of agricultural productivity and rural household income in Ethiopia. Three econometric models namely: Pooled ordinary least square (POLS), fixed effects (FE) and random effects (RE) model were used to examine the relationship between productivity and income; using Ethiopian socio-economic survey of 2011/12 and 2013/14 data, collected by CSA of Ethiopia in collaboration with the World Bank.Results showed that, Land-labor ratio, use of fertilizer, use of pesticide, manure and household size are found to be the most significant variables that affect agricultural labor and land productivity. However, drought has statistically significant and has negative effect on both labor and land productivity by the same magnitude. Labor productivity, non-farm income and land productivity are found to be the most determinants of household income. However, number of dependency ratio is significantly and negatively affects the rural household income. Sex of the household head is the main socio-economic factor for the variation of income among the rural households. The study also concludes that, Labor productivity is the most potent for factor of production and rural household income enhancement. The policy implication of the study is that, increasing land-labor ratio is important for agricultural productivity enhancement and promotion of both farm labor and non-farm income are best focusing to speed up for the enhancement of rural household income.Keywords: Labor productivity, Land productivity; Rural household income, Rural household panel data, Fixed effect mode

MOLECULAR GENETICS OF NODULE NUMBER REGULATION: CLONING, CHARACTERIZATION AND FUNCTIONAL STUDIES OF THE \u3ci\u3eROOT DETERMINED NODULATOR1 (RDN1) \u3c/i\u3eGENE IN \u3ci\u3eMedicago truncatula\u3c/i\u3e

Nitrogen is critical to life. However, the majority of nitrogen on earth (in the atmosphere) is inert and unavailable to nearly all organisms. Metabolically diverse prokaryotes are the only organisms capable of fixing atmospheric nitrogen; rhizobia set up a symbiosis with legume plants allowing the plants to benefit from this ability. Since nodulation and the subsequent nitrogen fixation processes are energy intensive, the host plant must balance hosting of the rhizobia by limiting the number of nodules it forms through a mechanism called Autoregulation of Nodulation (AON). My study of mutants in the model legume Medicago truncatula defective in AON allowed identification of loss-of-function alleles of the ROOT DETERMINED NODULATION1 (RDN1) gene (Medtr5g08952). I identified RDN1 by genetic mapping, transcript profiling, and rescue of the mutant phenotype. RDN1 is predicted to encode a 357-amino acid protein and is a member of an uncharacterized, highly conserved gene family unique to green plants. The promoter drives expression in the vascular cylinder and subcellular localization places RDN1 in the secretory pathway, consistent with a role for RDN1 in intracellular and long distance signaling in plants. I used grafted plants to show that RDN1 regulatory function occurs in the root before the shoot-derived suppression signal regulated by SUNN, another AON gene. Using a combination of gene expression assays, analysis of sunn/rdn1 double mutants and shoot-to-root reciprocal grafting I showed SUNN and RDN1 act in the same signaling pathway. RDN genes from poplar, rice and Arabidopsis can rescue the Mtrdn1 mutant suggesting RDN1 protein function is retained in non-legumes. I report multiple root defects in Arabidopsis and Medicago mutants with defects in RDN genes. Together these findings help establish RDN as a family of proteins with previously uncharacterized regulatory functions involved not only AON but also root growth and lateral root development in land plants. Building on RDN\u27s AON role, I also developed a split root inoculation system to understand the timing of autoregulation of nodulation in M. truncatula and discovered evidence for a previously unknown secondary AON signal

Determinants of Market Participation of Enset (Ensete Ventricosum) Farmers: The Case of Doyogena District, SNNPR, Ethiopia

Enset (Ensete ventricosum) is a traditional staple food crop in many parts of the densely populated south and south-western highlands of Ethiopia. It is a multipurpose crop whose every part is useful, however, kocho and bulla are the two main products processed from the crop. Enset can be dependable source of income in areas where it is grown. Doyogena district, southern Ethiopia, is one of the major producers of enset products. Despite its share in the market, there is limited empirical evidence on its products (kocho and bulla) market participation to design appropriate policies for improving smallholder market participation in the products. Therefore, this study analyzes determinants of kocho and bulla market participation of enset farm households in Doyogena district. Out of 13 kebeles producing enset, three of them were selected randomly for this study. A total of 154 households were selected randomly. Data were obtained through face to face interview and focus group discussion by using pre-tested questionnaire and checklists respectively. Heckman selection model (two-step) was used to estimate determinants of kocho and bulla market participation decision and intensity of participation. Eleven variables were hypothesized to determine market participation decision and intensity of participation of kocho and bulla producers. The model result indicated that, out of 154 producers interviewed, 68.2% and 71.4% of the respondents were kocho and bulla market participants respectively. The model output revealed that age of the household head, nearest market distance and area under enset cultivation as statistically significant determinants of market participation decision and intensity of participation of kocho producers. The model also shows age of household head, family size, nearest market distance and area under enset cultivation as statistically significant determinants of market participation decision and intensity of participation of bulla producers. Therefore, policies that aim in enhancing market participation of enset farmers should take into consideration the difference in response to the various factors that affect kocho and bulla market participation by enset farm households. Keywords: Bulla, Doyogena, enset, kocho, participation, Heckman (two-step) model, SNNPR, Ethiopi