Modeling the Personal Space of Virtual Agents for Behavior Simulation

In this paper we propose a mathematical model for the concept of personal space (PS) and apply it to simulate the non-verbal communication between agents in virtual worlds. The distance between two persons reflects the type of their relationship. Human-like autonomous virtual agents should be equipped with such capability to simulate natural interactions. We define three types of relationships; (1) stranger relationship, (2) business relationship, and (3) friendly relationship. First we model the space around an agent as a probability distribution function which reflects at each point in the space the importance of that point to the agent. The agent updates dynamically this function according to(1) his relation with the other agent, (2) his face orientation, and(3) the evolution of the relationship over time as a stranger agent may become a friend. We demonstrate the concept on a multi-agent platform and show that space-aware agents exhibit better natural behavior

HIV and STI Prevalence among Female Sex Workers in Côte d'Ivoire: Why Targeted Prevention Programs Should Be Continued and Strengthened

Objective: To assess condom use and prevalence of STIs and HIV among female sex workers (FSWs), as part of a comprehensive monitoring and evaluation plan of a nationwide sex worker prevention project in Côte d’Ivoire. Design and Methods: Cross sectional surveys were conducted among FSWs attending five project clinics in Abidjan and San Pedro (2007), and in Yamoussoukro and Gagnoa (2009). A standardized questionnaire was administered in a face-toface interview, which included questions on socio-demographic characteristics, sexual behaviour and condom use. After the interview, the participants were asked to provide samples for STI and HIV testing. Results: A total of 1110 FSWs participated in the surveys. There were large differences in socio-demographic and behavioural characteristics between FSW coming for the first time as compared to FSW coming on a routine visit. The prevalence of N. gonorrhoeae or C.trachomatis was 9.1%, 11.8 % among first vs. 6.9 % routine attendees (p = 0.004). The overall HIV prevalence was 26.6%, it was lower among first time attendees (17.5 % as compared to 33.9 % for routine attendees, p,0.001). The HIV prevalence among first attendees was also lower than the proportion of HIV positive tests from routine testing and counselling services in the same clinics. Conclusions: The results show a relatively high STI and HIV prevalence among FSWs in different cities in Côte d’Ivoire. In th

Down syndrome and postoperative complications after paediatric cardiac surgery: a propensity-matched analysis

OBJECTIVESThe incidence of congenital heart disease is approximately 50%, mostly related to endocardial cushion defects. The aim of our study was to investigate the postoperative complications that occur after paediatric cardiac surgery.METHODSOur perioperative data were analysed in paediatric patients with Down syndrome undergoing cardiac surgery. We retrospectively analysed the data from 2063 consecutive paediatric patients between January 2003 and December 2008. After excluding the patients who died or had missing data, the analysed database (before propensity matching) contained 129 Down patients and 1667 non-Down patients. After propensity matching, the study population comprised 222 patients and 111 patients had Down syndrome.RESULTSBefore propensity matching, the occurrences of low output syndrome (21.2 vs 32.6%, P = 0.003), pulmonary complication (14 vs 28.7%, P < 0.001) and severe infection (11.9 vs 22.5%, P = 0.001) were higher in the Down group. Down patients were more likely to have prolonged mechanical ventilation [median (interquartile range) 22 (9-72) h vs 49 (24-117) h, P = 0.007]. The total intensive care unit length of stay [6.9 (4.2-12.4) days vs 8.3 (5.3-13.2) days, P = 0.04] and the total hospital length of stay [17.3 (13.3-23.2) days vs 18.3 (15.1-23.6) days, P = 0.05] of the Down patients were also longer. Mortality was similar in the two groups before (3.58 vs 3.88%, P = 0.86) and after (5.4 vs 4.5%, P = 1.00) propensity matching. After propensity matching, there was no difference in the occurrence of adverse events.CONCLUSIONSAfter propensity matching Down syndrome was not associated with increased mortality or complication rate following congenital cardiac surgery

Non-Sexual Transmission of Trichomonas vaginalis in Adolescent Girls Attending School in Ndola, Zambia

OBJECTIVES: To identify risk factors for trichomoniasis among young women in Ndola, Zambia. METHOD: The study was a cross-sectional study among adolescent girls aged 13-16 years in Ndola, Zambia. Study participants were recruited from schools in selected administrative areas that represented the different socio-economic strata in town. Consenting participants were interviewed about their socio-demographic characteristics; sexual behaviour; and hygiene practices. Self-administered vaginal swabs were tested for Trichomonas vaginalis. HSV-2 antibodies were determined on serum to validate the self-reported sexual activity. RESULTS: A total of 460 girls participated in the study. The overall prevalence of trichomoniasis was 27.1%, 33.9% among girls who reported that they had ever had sex and 24.7% among virgins. In multivariate analysis the only statistically significant risk factor for trichomoniasis was inconsistent use of soap. For the virgins, none of the risk factors was significantly associated with trichomoniasis, but the association with use of soap (not always versus always) and type of toilet used (pit latrine/bush versus flush toilet) was of borderline significance. CONCLUSION: We found a high prevalence of trichomoniasis in girls in Ndola who reported that they had never had sex. We postulate that the high prevalence of trichomoniasis in virgins in Ndola is due to non-sexual transmission of trichomoniasis via shared bathing water and inconsistent use of soap

Stress from Nucleotide Depletion Activates the Transcriptional Regulator HEXIM1 to Suppress Melanoma

Studying cancer metabolism gives insight into tumorigenic survival mechanisms and susceptibilities. In melanoma, we identify HEXIM1, a transcription elongation regulator, as a melanoma tumor suppressor that responds to nucleotide stress. HEXIM1 expression is low in melanoma. Its overexpression in a zebrafish melanoma model suppresses cancer formation, while its inactivation accelerates tumor onset in vivo. Knockdown of HEXIM1 rescues zebrafish neural crest defects and human melanoma proliferation defects that arise from nucleotide depletion. Under nucleotide stress, HEXIM1 is induced to form an inhibitory complex with P-TEFb, the kinase that initiates transcription elongation, to inhibit elongation at tumorigenic genes. The resulting alteration in gene expression also causes anti-tumorigenic RNAs to bind to and be stabilized by HEXIM1. HEXIM1 plays an important role in inhibiting cancer cell-specific gene transcription while also facilitating anti-cancer gene expression. Our study reveals an important role for HEXIM1 in coupling nucleotide metabolism with transcriptional regulation in melanoma

Energy metabolism, altered proteins, sirtuins and ageing: converging mechanisms?

The predominant molecular symptom of ageing is the accumulation of altered gene products. Nutritional studies show that ageing in animals can be significantly influenced by dietary restriction. Genetics has revealed that ageing may be controlled by changes in intracellular NAD/NADH ratio regulating sirtuin activity. Physiological and other approaches indicate that mitochondria may also regulate ageing. A mechanism is proposed which links diet, exercise and mitochondria-dependent changes in NAD/NADH ratio to intracellular generation of altered proteins. It is suggested that ad libitum feeding conditions decrease NAD availability which also decreases metabolism of the triose phosphate glycolytic intermediates, glyceraldehyde-3-phosphate and dihydroxyacetone-phosphate, which can spontaneously decompose into methylglyoxal (MG). MG is a highly toxic glycating agent and a major source of protein advanced-glycosylation end-products (AGEs). MG and AGEs can induce mitochondrial dysfunction and formation of reactive oxygen species (ROS), as well as affect gene expression and intracellular signalling. In dietary restriction–induced fasting, NADH would be oxidised and NAD regenerated via mitochondrial action. This would not only activate sirtuins and extend lifespan but also suppress MG formation. This proposal can also explain the apparent paradox whereby increased aerobic activity suppresses formation of glycoxidized proteins and extends lifespan. Variation in mitochondrial DNA composition and consequent mutation rate, arising from dietary-controlled differences in DNA precursor ratios, could also contribute to tissue differences in age-related mitochondrial dysfunction

“No good man will ever want me”. How structural social inequality increases women’s vulnerability to HIV transmission: a qualitative study from Bandung, Indonesia

Understanding the pathways that expose women to HIV transmission are vital in improving HIV prevention, especially among a “hidden” group of women without pre-established known risk for HIV. We investigated the pathways which place certain women at greater risk for HIV in a qualitative exploratory study with theoretical sampling using an emergent theory study design in an urban setting in Indonesia. We conducted semi-structured interviews with 47 HIV-infected women, one focus group discussion with five young women who occassionally engage in sex work, participant observation at six sex work venues and two midwife clinics, and 11 informal interviews with midwives, nurses, and obstetricians. Our research found that many women not characterized as belonging to a “high-risk group” or “key population” were nevertheless at increased risk for HIV. A history of sexual abuse, premarital sex, divorce, or involvement in sex work, often precipitated by poverty coupled with discriminatory public health policies further heightened women’s exposure to HIV. While reaching at-risk populations is a key strategy in HIV prevention, a novel and more tailored approach is needed to reach more hidden categories of women with less apparent risk behavior yet considerable risk for HIV infection