A group theoretic approach to shear-free radiating stars

A systematic analysis of the junction condition, relating the radial pressure with the heat flow in a shear-free relativistic radiating star, is undertaken. This is a highly nonlinear partial differential equation in general. We obtain the Lie point symmetries that leave the boundary condition invariant. Using a linear combination of the symmetries, we transform the junction condition into ordinary differential equations. We present several new exact solutions to the junction condition. In each case we can identify the exact solution with a Lie point generator. Some of the solutions obtained satisfy the linear barotropic equation of state. As a special case we regain conformally flat models which were found previously. Our analysis highlights the interplay between Lie algebras, nonlinear differential equations and application to relativistic astrophysics.Comment: 11 pages, Submitted for publication, minor revision

Internally Displaced Persons & Covid-19 Under International Law

The issue of Internally Displaced Persons (IDP) has been overshadowed by global attention on those who flee across an international border, recognized as refugees. In most cases, the only difference between IDPs and refugees is crossing an international border. This research examines the plight of (IDPs) from the perspective of international law and the additional vulnerabilities the Covid 19 pandemic brought them. The rapid growth of IDPs due to wars and disasters is concerning. Furthermore, the challenges for these already vulnerable IDPs are exacerbated by the Covid-19 global pandemic. The authority to regulate IDPs and their rights is left to the sovereign nations they reside in. However, sovereignty is also grounds for not intervening internationally. This research will critically review international and regional conventions, commentaries, and other legal materials to expose the black hole of legal protections for IDPs. Whether existing legal frameworks and international institutions effectively protect their rights. This research will thoroughly analyze primary sources to demonstrate: (1) the vulnerability of IDPs; (2) the international legal framework available for their protection; (3) international institutions that offer humanitarian relief to guarantee the respect of the rights of the affected population; and (4) the added challenges of IDPs during the Covid-19 outbreak. (5) recommendations for the respect of human rights of IDPs. The research findings reveal the inconsistencies between the international rights granted to IDPs and their implementation

Implications of Urban Development-Induced Resettlement on Poor Households in Addis Ababa

This article examines the outcomes of recent slum resettlement projects on the socio-economic well-being of the relocated people in Addis Ababa. Drawing on qualitative methods involving observation, in-depth interviews and focus group discussions, the paper examines the benefits and challenges of urban development projects on the lives of poor relocated households. The empirical findings demonstrate that although relocated household benefited in terms of an improved quality of new houses, the city upgrading projects have negatively affected these families. Differential quality of housing and increasing costs of rent, income loss, changing schools for children, health problems and loss of savings were experienced. The study concludes that urban redevelopment and resettlement plans need to include the implications of relocation on the lives and livelihood opportunities of poor households.Keywords: Urban development; resettlement; poor households; livelihoods; social networks,Addis Abab

Perception of High School Students towards Voluntary HIV Counseling and Testing, using Health Belief Model in Butajira, SNNPR

Background: Voluntary counseling and testing (VCT) for HIV is one of the strategies for HIV/AIDS prevention, and yet, there is very little information on what influences the services in Ethiopia. Objective: To assess the perception and attitude of students towards VCT services using the Health Belief Model. Methods: A cross sectional descriptive study was conducted in January 2006, among Butajira senior secondary school students where a multi stage sampling method was used. Results: About ninety seven percent of the students had heard about VCT services but less than one fifth of them had undergone VCT. Eighty two percent of the students were willing to undergo VCT. It was shown that willingness to VCT was significantly associated with perceived susceptibility [AOR=0.37(0.28, 0.89)], perceived barrier [AOR= 0.45 (0.23, 0.89)] and perceived benefit [AOR=1.79 (1.44, 2.49)]. Conclusions: The majority of students had heard about VCT and revealed willingness to undergo VCT. High perceived susceptibility and barriers were associated with low willingness to undergo VCT. On the other hand, students with high perceived benefits showed better willingness to undergo VCT. It is recommended that messages onVCT give emphasis on personal susceptibility to HIV/AIDS and benefits of VCT

A cross-sectional study on bovine trypanosomosis in Jawi district of Amhara Region, Northwest Ethiopia

A cross-sectional study was carried out from December 2008 to March 2009 in Jawi district of Amhara Regional State northwest Ethiopia to assess the prevalence of bovine trypanosomosis. Blood sample was collected randomly from a total of 300 cattle through piercing of the marginal ear vein to determine the prevalence and measure PCV values for the assessment of anemia. During sampling age, sex and body condition of the animals were recorded to infer risk factors for the occurrence of the disease. The buffy coat technique was em ployed for the detection of trypanosome and to measure PCV values. Thin blood smear was made from positive samples for species identification of the parasite. The prevalence of trypanosomosis was found to be 11.33% (95% CI: 0.08 - 0.15%) in Jawi district of which higher prevalence with species of trypanosome was detected to be for T. congolense (65%) than T. vivax (35%). The prevalence showed no significant difference in susceptibility between sex categories and in age groups. The infection rate between body condition score in parasitaemic and aparasitaemic animals was significantly different (P< 0.05) that poor body conditioned animals were more affected by trypanosomes than good conditioned animals. The mean PCV values in parasitaemic animals was 24.29% +5.58SD while in aparasitaemic animals 27.46% +5.67SD with a statistical significant difference (

A retrospective study on prevalence and antimicrobial susceptibility patterns of bacterial isolates from urinary tract infections in Tikur Anbessa Specialized Teaching Hospital Addis Ababa, Ethiopia, 2011

Introduction: Urinary tract infection is an inflammation of the urinary tract that occurs when micro organisms, usually bacteria from digestive tract or  vagina cling to the opening of the urethra and begin to multiply. An estimated 150 million urinary tract infections occur annually worldwide. Indiscriminate use of antibiotics has resulted in the emergence of drug resistant pathogens now.Objective: To determine the prevalence and drug susceptibility patterns of bacterial pathogens involved in urinary tract infections within the last three years, January 1st 2008 to December 30th 2010 in Tikur Anbesa Specialized Teaching Hospital of Addis Ababa, Ethiopia.Method: An institution-based retrospective cross sectional population survey was conducted in the clinical laboratory for diagnosis of patients visiting Tikur Anbessa Specialized Teaching Hospital. Collected secondary data were entered and analyzed using SPSS version 17 computer software package. Percentages and ratios were calculated in tables. P-value was used to see statistical significance (p&lt;0.05).Results: Out of 3254 recorded patient’s data 3182 results were taken and analyzed. The overall prevalence of urinary tract infection was 23.32 % and the highest prevalence was obtained among age groups 21-30 years (27.16%). The bacterial pathogens isolated were predominantly, Escherchia coli: 361 (44.62%), followed by Klebsella Spp: 136 (16.81%), Coaggulase negative Staphylococci Spp: 49 (6.06%) and Entrococci Spp: 41 (5.06%). The invitro drug sensitivity testing showed that both gram negative and gram-positive organisms were extremely resistant to Ampiciline: (83.93%), Amoxicillin: (78.87%) and Tetracycline: (77.75%).Conclusion: the prevalence of urinary tract infection was high, and the drug resistance rate was extremely high. For this reason, it is necessary to minimize the rate of urinary tract infections, and to constantly monitor susceptibility patterns of specific pathogens to commonly used antimicrobial agents before antibiotic therapy initiation