A non-singular black hole model as a possible end-product of gravitational collapse

In this paper we present a non-singular black hole model as a possible end-product of gravitational collapse. The depicted spacetime which is type [II,(II)], by Petrov classification, is an exact solution of the Einstein equations and contains two horizons. The equation of state in the radial direction, is a well-behaved function of the density and smoothly reproduces vacuum-like behavior near r=0 while tending to a polytrope at larger r, low density, values. The final equilibrium configuration comprises of a de Sitter-like inner core surrounded by a family of 2-surfaces of matter fields with variable equation of state. The fields are all concentrated in the vicinity of the radial center r=0. The solution depicts a spacetime that is asymptotically Schwarzschild at large r, while it becomes de Sitter-like for vanishing r. Possible physical interpretations of the macro-state of the black hole interior in the model are offered. We find that the possible state admits two equally viable interpretations, namely either a quintessential intermediary region or a phase transition in which a two-fluid system is in both dynamic and thermodynamic equilibrium. We estimate the ratio of pure matter present to the total energy and in both (interpretations) cases find it to be virtually the same, being 0.83. Finally, the well-behaved dependence of the density and pressure on the radial coordinate provides some insight on dealing with the information loss paradox.Comment: 12 Pages, 1 figure. Accepted for publication in Phys. Rev.

Ebola Viral Hemorrhagic Disease Outbreak in West Africa- Lessons from Uganda.

Background: There has been a rapid spread of Ebola Viral Hemorrhagic disease in Guinea, Liberia and Sierra Leone since March 2014. Since this is the first time of a major Ebola outbreak in West Africa; it is possible there is lack of understanding of the epidemic in the communities, lack of experience among the health workers to manage the cases and limited capacities for rapid response. The main objective of this article is to share Uganda’s experience in controlling similar Ebola outbreaks and to suggest some lessons that could inform the control of the Ebola outbreak in West Africa.Methods: The article is based on published papers, reports of previous Ebola outbreaks, response plans and experiences of individuals who have participated in the control of Ebola epidemics in Uganda.Lessons learnt: The success in the control of Ebola epidemics in Uganda has been due to high political support, effective coordination through national and district task forces. In addition there has been active surveillance, strong community mobilization using village health teams and other community resources persons, an efficient laboratory system that has capacity to provide timely results. These have coupled with effective case management and infection control and the involvement of development partners who commit resources with shared responsibility.Conclusion: Several factors have contributed to the successful quick containment of Ebola outbreaks in Uganda. West African countries experiencing Ebola outbreaks could draw some lessons from the Uganda experience and adapt them to contain the Ebola epidemic.Key words: Ebola, viral hemorrhagic fever, West Africa, lessons, Ugand

Time evolution of a non-singular primordial black hole

There is growing notion that black holes may not contain curvature singularities (and that indeed nature in general may abhor such spacetime defects). This notion could have implications on our understanding of the evolution of primordial black holes (PBHs) and possibly on their contribution to cosmic energy. This paper discusses the evolution of a non-singular black hole (NSBH) based on a recent model [1]. We begin with a study of the thermodynamic process of the black hole in this model, and demonstrate the existence of a maximum horizon temperature T_{max}, corresponding to a unique mass value. At this mass value the specific heat capacity C changes signs to positive and the body begins to lose its black hole characteristics. With no loss of generality, the model is used to discuss the time evolution of a primordial black hole (PBH), through the early radiation era of the universe to present, under the assumption that PBHs are non-singular. In particular, we track the evolution of two benchmark PBHs, namely the one radiating up to the end of the cosmic radiation domination era, and the one stopping to radiate currently, and in each case determine some useful features including the initial mass m_{f} and the corresponding time of formation t_{f}. It is found that along the evolutionary history of the universe the distribution of PBH remnant masses (PBH-RM) PBH-RMs follows a power law. We believe such a result can be a useful step in a study to establish current abundance of PBH-MRs.Comment: To appear in Int. J. Mod. Phys.

'It is like a tomato stall where someone can pick what he likes': structure and practices of female sex work in Kampala, Uganda.

BACKGROUND: Effective interventions among female sex workers require a thorough knowledge of the context of local sex industries. We explore the organisation of female sex work in a low socio-economic setting in Kampala, Uganda. METHODS: We conducted a qualitative study with 101 participants selected from an epidemiological cohort of 1027 women at high risk of HIV in Kampala. Repeat in-depth life history and work practice interviews were conducted from March 2010 to June 2011. Context specific factors of female sex workers' day-to-day lives were captured. Reported themes were identified and categorised inductively. RESULTS: Of the 101 women, 58 were active self-identified sex workers operating in different locations within the area of study and nine had quit sex work. This paper focuses on these 67 women who gave information about their involvement in sex work. The majority had not gone beyond primary level of education and all had at least one child. Thirty one voluntarily disclosed that they were HIV-positive. Common sex work locations were streets/roadsides, bars and night clubs. Typically sex occurred in lodges near bars/night clubs, dark alleyways or car parking lots. Overall, women experienced sex work-related challenges at their work locations but these were more apparent in outdoor settings. These settings exposed women to violence, visibility to police, a stigmatising public as well as competition for clients, while bars provided some protection from these challenges. Older sex workers tended to prefer bars while the younger ones were mostly based on the streets. Alcohol consumption was a feature in all locations and women said it gave them courage and helped them to withstand the night chill. Condom use was determined by clients' willingness, a woman's level of sobriety or price offered. CONCLUSIONS: Sex work operates across a variety of locations in the study area in Kampala, with each presenting different strategies and challenges for those operating there. Risky practices are present in all locations although they are higher on the streets compared to other locations. Location specific interventions are required to address the complex challenges in sex work environments

Consensus and contention in the priority setting process: examining the health sector in Uganda.

Health priority setting is a critical and contentious issue in low-income countries because of the high burden of disease relative to the limited resource envelope. Many sophisticated quantitative tools and policy frameworks have been developed to promote transparent priority setting processes and allocative efficiency. However, low-income countries frequently lack effective governance systems or implementation capacity, so high-level priorities are not determined through evidence-based decision-making processes. This study uses qualitative research methods to explore how key actors' priorities differ in low-income countries, using Uganda as a case study. Human resources for health, disease prevention and family planning emerge as the common priorities among actors in the health sector (although the last of these is particularly emphasized by international agencies) because of their contribution to the long-term sustainability of health-care provision. Financing health-care services is the most disputed issue. Participants from the Ugandan Ministry of Health preferentially sought to increase net health expenditure and government ownership of the health sector, while non-state actors prioritized improving the efficiency of resource use. Ultimately it is apparent that the power to influence national health outcomes lies with only a handful of decision-makers within key institutions in the health sector, such as the Ministries of Health, the largest bilateral donors and the multilateral development agencies. These power relations reinforce the need for ongoing research into the paradigms and strategic interests of these actors

Social and Cultural Factors Affecting Uptake of Interventions for Malaria in Pregnancy in Africa: A Systematic Review of the Qualitative Research

Malaria during pregnancy (MiP) results in adverse birth outcomes and poor maternal health. MiP-related morbidity and mortality is most pronounced in sub-Saharan Africa, where recommended MiP interventions include intermittent preventive treatment, insecticide-treated bednets and appropriate case management. Besides their clinical efficacy, the effectiveness of these interventions depends on the attitudes and behaviours of pregnant women and the wider community, which are shaped by social and cultural factors. Although these factors have been studied largely using quantitative methods, qualitative research also offers important insights. This article provides a comprehensive overview of qualitative research on social and cultural factors relevant to uptake of MiP interventions in sub-Saharan Africa.A systematic search strategy was employed: literature searches were undertaken in several databases (OVID SP, IS Web of Knowledge, MiP Consortium library). MiP-related original research, on social/cultural factors relevant to MiP interventions, in Africa, with findings derived from qualitative methods was included. Non-English language articles were excluded. A meta-ethnographic approach was taken to analysing and synthesizing findings. Thirty-seven studies were identified. Fourteen concentrated on MiP. Others focused on malaria treatment and prevention, antenatal care (ANC), anaemia during pregnancy or reproductive loss. Themes identified included concepts of malaria and risk in pregnancy, attitudes towards interventions, structural factors affecting delivery and uptake, and perceptions of ANC.Although malaria risk is associated with pregnancy, women's vulnerability is often considered less disease-specific and MiP interpreted in locally defined categories. Furthermore, local discourses and health workers' ideas and comments influence concerns about MiP interventions. Understandings of ANC, health worker-client interactions, household decision-making, gender relations, cost and distance to health facilities affect pregnant women's access to MiP interventions and lack of healthcare infrastructure limits provision of interventions. Further qualitative research is however required: many studies were principally descriptive and an in-depth comparative approach is recommended

Neutrinos in a vacuum dominated cosmology

We explore the dynamics of neutrinos in a vacuum dominated cosmology. First we show that such a geometry will induce a phase change in the eigenstates of a massive neutrino and we calculate the phase change. We also calculate the delay in the neutrino flight times in this geometry. Applying our results to the presently observed background vacuum energy density, we find that for neutrino sources further than $1.5 Gpc$ away both effects become non-trivial, being of the order of the standard relativistic corrections. Such sources are within the obsevable Hubble Deep Field. The results which are theoretically interesting are also potentially useful, in the future, as detection techniques improve. For example such effects on neutrinos from distant sources like supernovae could be used, in an independent method alternative to standard candles, to constrain the dark energy density and the deceleration parameter. The discussion is extended to investigate Caianiello's inertial or maximal acceleration (MA) effects of such a vacuum dominated spacetime on neutrino oscillations. Assuming that the MA phenomenon exists, we find that its form as generated by the presently observed vacuum energy density would still have little or no measurable effect on neutrino phase evolution.Comment: 10 pages, LaTeX, no figure

An integrated approach to emergency triage assessment and treatment in Uganda

Background: Reducing mortality among patients who present to primary referral facilities in need of emergency care requires efficient triage and immediate correct management known more commonly as Emergency Triage, Assessment and Treatment (ETAT). Integrated Management of Infectious Disease (IMID) training and on-site support (OSS) have been the tools used to build capacity among mid-level practitioners who have been found to be lacking in ETAT skills in the region.Objective: To investigate the use of Integrated Management of Infectious Disease (IMID) training and on-site support (OSS) tools to improve ETAT in health care facilities in rural Uganda.Design: Randomized mixed methods evaluation.Setting: Thirty-six facilities in Uganda were randomized 1:1 to arm A (IMID and OSS) and arm B (IMID alone).Subjects: Two mid-level practitioners, (clinical officers or senior nurses), from each facility participated in offsite IMID training. Staff at 18 facilities in arm A participated in OSS (two days each month of outreach and quality improvement for nine months).Results: Time series data on facility performance of three ETAT indicators were compared over 14 months and data on mortality among pediatric inpatients were compared across arms. Improvements differed across facilities and indicators, but steady improvement in triage occurred in arm A, with convergence across arms in the management of emergency patients. Analysis of baseline indicators and improvements demonstrated that facilities could improve their performance regardless of their starting point.Conclusion: IMID and OSS both improved the management of patients with an acute illness presenting to rural health facilities