36 research outputs found
Impact of antenna correlation on the performance of partial relay selection
Antenna correlation is generally viewed as an obstacle to realize the desired performance of a wireless system. In this article, we investigate the performance of partial relay selection in the presence of antenna correlation. We consider both channel state information (csi)-assisted and fixed gain amplify-and-forward (AF) relay schemes. The source and the destination are equipped with multiple antennas communicating via the best first hop signal-to-noise ratio (SNR) relay. We derived the closed form expression for outage probability, average symbol error rate (SER) for both schemes. Further, an exact expression is derived for the ergodic capacity in the csi-assisted relay case and an approximated expression is considered for the fixed gain case. Moreover, we provide simple asymptotic results and show that the diversity order of the system remains unchanged with the effect of antenna correlation for both types of relay schemes
A randomized trial of multivitamin supplementation in children with tuberculosis in Tanzania
Children with tuberculosis often have underlying nutritional deficiencies. Multivitamin supplementation has been proposed as a means to enhance the health of these children; however, the efficacy of such an intervention has not been examined adequately. 255 children, aged six weeks to five years, with tuberculosis were randomized to receive either a daily multivitamin supplement or a placebo in the first eight weeks of anti-tuberculous therapy in Tanzania. This was only 64% of the proposed sample size as the trial had to be terminated prematurely due to funding constraints. They were followed up for the duration of supplementation through clinic and home visits to assess anthropometric indices and laboratory parameters, including hemoglobin and albumin. There was no significant effect of multivitamin supplementation on the primary endpoint of the trial: weight gain after eight weeks. However, significant differences in weight gain were observed among children aged six weeks to six months in subgroup analyses (n=22; 1.08 kg, compared to 0.46 kg in the placebo group; 95% CI=0.12, 1.10; p=0.01). Supplementation resulted in significant improvement in hemoglobin levels at the end of follow-up in children of all age groups; the median increase in children receiving multivitamins was 1.0 g/dL, compared to 0.4 g/dL in children receiving placebo (p<0.01). HIV-infected children between six months and three years of age had a significantly higher gain in height if they received multivitamins (n=48; 2 cm, compared to 1 cm in the placebo group; 95% CI=0.20, 1.70; p=0.01; p for interaction by age group=0.01). Multivitamin supplementation for a short duration of eight weeks improved the hematological profile of children with tuberculosis, though it didn't have any effect on weight gain, the primary outcome of the trial. Larger studies with a longer period of supplementation are needed to confirm these findings and assess the effect of multivitamins on clinical outcomes including treatment success and growth failure. CLINICALTRIALS.GOV IDENTIFIER: NCT00145184
Testing Developmental Pathways to Antisocial Personality Problems
This study examined the development of antisocial personality problems (APP) in young adulthood from disruptive behaviors and internalizing problems in childhood and adolescence. Parent ratings of 507 childrenâs (aged 6â8Â years) symptoms of attention deficit hyperactivity disorder, oppositional defiant disorder, and anxiety, were linked to self-ratings of adolescentsâ (aged 14â16Â years) symptoms of depression, substance use, conduct problems, and somatic problems, to predict self-ratings of APP in young adulthood (age 20â22Â years). The findings suggested a hierarchical development of antisocial behavior problems. Despite being positively associated with conduct problems in adolescence, neither internalizing problems nor substance use added to the prediction of APP in young adulthood from conduct problems in adolescence. The developmental pathways to APP in young adulthood did not differ by gender
Insomnia symptoms and repressive coping in a sample of older Black and White women
BACKGROUND: This study examined whether ethnic differences in insomnia symptoms are mediated by differences in repressive coping styles. METHODS: A total of 1274 women (average age = 59.36 ± 6.53 years) participated in the study; 28% were White and 72% were Black. Older women in Brooklyn, NY were recruited using a stratified, cluster-sampling technique. Trained staff conducted face-to-face interviews lasting 1.5 hours acquiring sociodemographic data, health characteristics, and risk factors. A sleep questionnaire was administered and individual repressive coping styles were assessed. Fisher's exact test and Spearman and Pearson analyses were used to analyze the data. RESULTS: The rate of insomnia symptoms was greater among White women [74% vs. 46%; Ï(2 )= 87.67, p < 0.0001]. Black women scored higher on the repressive coping scale than did White women [Black = 37.52 ± 6.99, White = 29.78 ± 7.38, F(1,1272 )= 304.75, p < 0.0001]. We observed stronger correlations between repressive coping and insomnia symptoms for Black [r(s )= -0.43, p < 0.0001] than for White women [r(s )= -0.18, p < 0.0001]. Controlling for variation in repressive coping, the magnitude of the correlation between ethnicity and insomnia symptoms was substantially reduced. Multivariate adjustment for differences in sociodemographics, health risk factors, physical health, and health beliefs and attitudes had little effect on the relationships. CONCLUSION: Relationships between ethnicity and insomnia symptoms are jointly dependent on the degree of repressive coping, suggesting that Black women may be reporting fewer insomnia symptoms because of a greater ability to route negative emotions from consciousness. It may be that Blacks cope with sleep problems within a positive self-regulatory framework, which allows them to deal more effectively with sleep-interfering psychological processes to stressful life events and to curtail dysfunctional sleep-interpreting processes
Perceptions of body size, obesity threat and the willingness to lose weight among black South African adults: a qualitative study
BACKGROUND: The obesity epidemic is associated with rising rates of cardiovascular disease (CVD) among adults,
particularly in countries undergoing rapid urbanisation and nutrition transition. This study explored the perceptions
of body size, obesity risk awareness, and the willingness to lose weight among adults in a resource-limited urban
community to inform appropriate community-based interventions for the prevention of obesity.
METHOD: This is a descriptive qualitative study. Semi-structured focus group discussions were conducted with
purposively selected black men and women aged 35â70 years living in an urban South African township. Weight
and height measurements were taken, and the participants were classified into optimal weight, overweight and
obese groups based on their body mass index (Kg/m2). Participants were asked to discuss on perceived obesity
threat and risk of cardiovascular disease. Information on body image perceptions and the willingness to lose excess
body weight were also discussed. Discussions were conducted in the local language (isiXhosa), transcribed and
translated into English. Data was analysed using the thematic analysis approach.
RESULTS: Participants generally believed that obesity could lead to health conditions such as heart attack, stroke,
diabetes, and hypertension. However, severity of obesity was perceived differently in the groups. Men in all groups
and women in the obese and optimal weight groups perceived obesity to be a serious threat to their health,
whereas the overweight women did not. Obese participants who had experienced chronic disease conditions
indicated strong perceptions of risk of obesity and cardiovascular disease. Obese participants, particularly men,
expressed willingness to lose weight, compared to the men and women who were overweight. The belief that
overweight is ânormalâ and not a disease, subjective norms, and inaccessibility to physical activity facilities,
negatively influenced participantsâ readiness to lose weight.
CONCLUSION: Low perception of threat of obesity to health particularly among overweight women in this
community indicates a considerable challenge to obesity control. Community health education and promotion
programmes that increase awareness about the risk associated with overweight, and improve the motivation for
physical activity and maintenance of optimal body weight are needed.IS
âI attend at Vanguard and I attend here as wellâ: barriers to accessing healthcare services among older South Africans with HIV and non-communicable diseases
Background: HIV and non-communicable disease (NCD) are syndemic within sub-Saharan Africa especially among
older persons. The two epidemics interact with one another within a context of poverty, inequality and inequitable
access to healthcare resulting in an increase in those aged 50 and older living with HIV and experiencing an NCD comorbidity.
We explore the challenges of navigating healthcare for older persons living with HIV and NCD co-morbidity.
Methods: In-depth semi-structured interviews were conducted with a small sample of older persons living with HIV
(OPLWH). The perspectives of key informants were also sought to triangulate the evidence of OPLWH. The research
took place in two communities on the outskirts of Cape Town, South Africa. All interviews were conducted by a
trained interviewer and transcribed and translated for analysis. Thematic content analysis guided data analysis.
Results: OPLWH experienced an HIV-NCD syndemic. Our respondents sought care and accessed treatment for both
HIV and other chronic (and acute) conditions, though these services were provided at different health facilities or by
different health providers. Through the syndemic theory, it is possible to observe that OPLWH and NCDs face a
number of physical and structural barriers to accessing the healthcare system. These barriers are compounded by
separate appointments and spaces for each condition. These difficulties can exacerbate the impact of their ill-health
and perpetuate structural vulnerabilities. Despite policy changes towards integrated care, this is not the experience of
OPLWH in these communities.
Conclusions: The population living with HIV is aging increasing the likelihood that those living with HIV will also be
living with other chronic conditions including NCDs. Thus, it is essential that health policy address this basic need to
integrate HIV and NCD care
Brain E-Learner
The objective of this extended abstract is to present Brain e-Learning System -which ^vas developed and tested final year undergraduate project at the department of Electronic and Telecommunication Engineering university Moratuwa, Sri Lanka. The Brain e-Learning System is an integrated on-line system for remote education covering aspects of Medical Image Analysis, Remote patient monitoring, Video/Audio Conferencing and Brain E-Learning materials. It provides user-friendly web interface and optimized functionality with three different access medical students, medical consultants and administrato