Exact analysis of weighted centroid localization

Source localization of primary users (PUs) is a geolocation spectrum awareness feature that can be very useful in enhancing the functionality of cognitive radios (CRs). When the cooperating CRs have limited information about the PU, weighted centroid localization (WCL) based on received signal strength (RSS) measurements represents an attractive low-complexity solution. In this paper, we propose a new analytical framework to calculate the exact performance of WCL in the presence of shadowing, based on results of the ratio of two quadratic forms in normal variables. In particular, we derive an exact expression for the root mean square error (RMSE) of the two-dimensional location estimate. Numerical results confirm that the derived framework is able to predict the performance of WCL capturing all the essential aspects of propagation as well as CR network spatial topology

The changing role of the primary school teacher in Swaziland in the context of HIV/AIDS: teacher as caretaker and economic provider.

Swaziland has the world’s highest HIV prevalence with 26% of adults aged 15-49 years living with HIV. There are approximately 17,000 Swazi children aged 0 to 14 years living with HIV. This qualitative study explored the experiences of Swazi teachers supporting learners living with or affected by HIV/AIDS, with a specific focus on the extent to which teachers are aware of the “Rights of the Child” in their teaching and approaches. Important themes emerged from thematic analysis including the following: teachers provided more than education to learners living with and affected by HIV, including material goods and additional time, in some cases at the expense of other learners. In the era of HIV/AIDS, the teacher has become the emotional caretaker and economic provider in addition to the predictable role of educator in Swaziland. Education curricula in HIV-burdened countries need to modify training programmes and support services available to teachers to accommodate the complex role that teachers play in caring for learners living with and affected by HIV

Mozwane or party in motion : A driver for HIV infection among adolescents in Botswana

Session presented on Saturday, July 23, 2016 and Sunday, July 24, 2016: Introduction: Adolescents have low rates of HIV infection but are at high risk of adverse sexual health outcomes because of early engagement in unsafe sexual behaviors. The concept of \u27Mozwane\u27 or \u27party in motion\u27 has been identified by adolescents in Gaborone, Botswana as one of the drivers of adolescent sexuality problems. We explored the concept further to inform a proposed adolescent HIV, sexually transmitted infections (STI) and pregnancy prevention intervention. Methods: This was part of a larger cross-sectional qualitative study, conducted between December 2011 and January 2012, on adolescents\u27 sexual behavior, to inform an adolescent HIV, sexually transmitted infections (STI) and pregnancy prevention intervention. Forty adolescents selected through purposive sampling from high schools in Gaborone participated in a focus group discussion. The discussions for this part of the study focused on the understanding \u27Mozwane\u27, examples of its usage, the associated antecedents and consequences and what it meant in the context of HIV, STI and pregnancy prevention. Adolescents and parents/guardians gave written informed consent. Approval was obtained from the Ministry of Health Research and Development Committee, Ministry of Education and Skills Development, and University of Botswana Research and Development office. Results: The participants were aged between 15 and 18 years. They explained that \u27Mozwane\u27 is a common activity among adolescents. It involves collecting contributions to hire transport (a minibuses or combis) on weekends to look for fun parties around the city, without the knowledge of parents. They also use the contributions to purchase alcohol. During travel they\u27d have moving parties, drink, take drugs, and exchange sex, with the combi driver also participating. They agreed that this increased their risk for HIV, STIs and pregnancy. Discussion and conclusion: The results documented additional sexuality risks of adolescents and the need for focused education for adolescents and parents. There is need for further countrywide research on the concept and risk perception of adolescents related to this behavior. Key words: \u27Mozwane\u27, \u27party in motion\u27, adolescents, sexuality risks, weekend parties

Blind localization of radio emitters in wireless communications

The proliferation of wireless services is expected to increase the demand for radio spectrum in the foreseeable future. Given the limitations of the radio spectrum, it is evident that the current fixed frequency assignment policy fails to accommodate this increasing demand. Thus, the need for innovative technologies that can scale to accommodate future demands both in terms of spectrum efficiency and high reliable communication. Cognitive radio (CR) is one of the emerging technologies that offers a more flexible use of frequency bands allowing unlicensed users to exploit and use portions of the spectrum that are temporarily unused without causing any potential harmful interference to the incumbents. The most important functionality of a CR system is to observe the radio environment through various spectrum awareness techniques e.g., spectrum sensing or detection of spectral users in the spatio-temporal domain. In this research, we mainly focus on one of the key cognitive radio enabling techniques called localization, which provides crucial geo-location of the unknown radio transmitter in the surrounding environment. Knowledge of the user’s location can be very useful in enhancing the functionality of CRs and allows for better spectrum resource allocations in the spatial domain. For instance, the location-awareness feature can be harnessed to accomplish CR tasks such as spectrum sensing, dynamic channel allocation and interference management to enable cognitive radio operation and hence to maximize the spectral utilization. Additionally, geo-location can significantly expand the capabilities of many wireless communication applications ranging from physical layer security, geo-routing, energy efficiency, and a large set of emerging wireless sensor network and social networking applications. We devote the first part of this research to explore a broad range of existing cooperative localization techniques and through Monte-Carlo simulations analyze the performance of such techniques. We also propose two novel techniques that offer better localization performance with respect to the existing ones. The second and third parts of this research put forth a new analytical framework to characterize the performance of a particular low-complexity localization technique called weighted centroid localization (WCL), based on the statistical distribution of the ratio of two quadratic forms in normal variables. Specifically, we evaluate the performance of WCL in terms of the root mean square error (RMSE) and cumulative distribution function (CDF). The fourth part of this research focuses on studying the bias of the WCL and also provides solutions for bias correction. Throughout this research, we provide a case study analysis to evaluate the performance of the proposed approaches under changing channel and environment conditions. For the new theoretical framework, we compare analytical and Monte-Carlo simulation results of the performance metric of interest. A key contribution in our analysis is that we present not only the accurate performance in terms of the RMSE and CDF, but a new analytical framework that takes into consideration the finite nature of the network, overcoming the limitations of asymptotic results based on the central limit theorem. Remarkably, the numerical results unfold that the new analytical framework is able to predict the performance of WCL capturing all the essential aspects of propagation as well as the cognitive radio network spatial topology. Finally, we present conclusions gained from this research and possible future directions

Impediments for the Uptake of the Botswana Government's Male Circumcision Initiative for HIV Prevention

Botswana remains one of the countries with high prevalence of HIV infection with a population prevalence rate of 17.6 in 2008. In 2009, the Ministry of Health launched male circumcision as an additional strategy to the already existing HIV preventive efforts. The purpose of this paper is to share what the participants of a survey to evaluate a short-term male circumcision communication strategy in seven health districts of Botswana reported as impediments for the program's uptake. Qualitative data were obtained from 32 key informants and 36 focus group discussions in 2011. Content analysis method was used to analyze data and to derive themes and subthemes. Although male circumcision was generally acceptable to communities in Botswana, the uptake of the program was slow, and participants attributed that to a number of challenges or impediments that were frustrating the initiative. The impediments were organized into sociocultural factors, knowledge/informational factors, and infrastructural and system factors

Shaping the Role of sub-Saharan African Nurses and Midwives: Stakeholder’s perceptions of the Nurses’ and Midwives’ tasks and roles

To explore the role expectations of different stakeholders in the health care system on the roles and tasks that nurses and midwives perform, in order to clarify and strengthen these roles and shape the future of nursing education and practice in sub-Saharan Africa. Qualitative focus group discussions were held with different stakeholders (nurses, health service managers, patients and their caregivers, community members and leaders and other health professionals) in eight African countries in order to establish their role expectations of nurses and midwives. Three questions about their role expectations and the interviews were taped, transcribed, and translated into English and analysed. There was consensus amongst the stakeholders regarding eight role functions: taking care of patients; giving health information; managing the care environment; advocating for patients; services and policies; providing emergency care; collaborating with other stakeholders; and providing midwifery care to women, infants and their families. There was disagreement amongst the stakeholders about the role of diagnosis and prescribing treatment. Nursing derives its mandate from communities it serves, and the roles expected must therefore form part of nursing regulation, education and practice standards. Health planners must use these as a basis for job descriptions and rewards. Once these are accepted in the training and regulation of nursing, they must be marketed so that recipients are aware thereof.Om die rol verwagtings van verskillende rolspelers in die gesondheidsisteem aangaande die rolle en take van die verpleegkundiges en vroedvroue te ondersoek, om daardeur uitklaring en helderheid en bekragtiging van hierdie rolle te verkry, waardeur die toekoms van verpleeg-onderwys en praktyk in sub-Sahara Afrika gevorm kan word. Kwalitatiewe fokus groepe is met verskillende rolspelers (verpleegkundiges, gesondheidsdiens bestuurders, pasiënte en hulle versorgers, lede van die gemeenskap, leiers en lede van andere gesondheidsprofessies) in agt Afrika lande gehou om hul rolverwagtings van verpleegkundiges en vroedvroue te bepaal. Drie vrae is oor die rolverwagtings gevra. Die onderhoude is opgeneem, getranskribeer, in Engels vertaal, en geanaliseer. Daar was konsensus tussen rolspelers oor agt rol funksies: versorging van pasiënte; die gee van gesondheidsinligting; bestuur van die sorgomgewing; voorspraak vir pasiënte; dienste en beleid; voorsiening van nooddienste; samewerking met ander rolspelers; en voorsiening aan moeder en kindersorg vir vroue en hul gesinne. Ooreenstemming is nie bereik aangaande die rol van diagnose en voorskryf van behandeling nie. Verpleging kry sy mandaat van die gemeenskappe wat gedien word en daarom behoort die rolverwagtings deel te vorm van verpleeg-regulasie, onderwys en praktyk- standaarde. Gesondheidsdiensbeplanners behoort hierdie verwagtings as basis te gebruik vir werksbeskrywings en erkenning. Na die aanvaarding van hierdie verwagtings in verpleegopleiding en regulering, moet dit bekend gemaak word sodat die gemeenskap daarvan bewus is. </jats:p

Study on the relationship between lineaments and borehole specific capacity in a fractured and karstified limestone area in Vietnam

For a karstified limestone area in NW Vietnam, the relationship between the distribution of lineaments and borehole specific capacity is determined, resulting in the conclusion that not only the borehole geomorphological-hydrogeological position but also the lineament distribution influences the specific capacity. No significant spatial well yield patterns are evident in this highly fractured-karstified region. The supposition is that lineaments caused by geotectonic activities affect the local variability in borehole specific capacity. Sixteen pumping tests in conjunction with a comprehensive lineament analysis are used to prove this relationship. The boreholes and lineaments are classified into two groups according to their similarity in geomorphological-hydrogeological features. Lineaments tend to be less detectable in discharge areas (lowland, wide and flat valleys) in contrast to the high density in recharge areas (highland narrow-mountainous ravines). In addition, the presence of a stream network in the former can act as a recharge source to the underlain karstic groundwater system. Consequently, boreholes that are in the discharge areas with a lower density of lineaments often produce high yield. For recharge areas with a high density of lineaments, a good correlation is found between lineament density and borehole specific capacity