Does age matter? Sexual event-level analysis of age-disparate sexual partners among gay, bisexual and other men who have sex with men (GBM) in Vancouver, Canada.

BACKGROUND: To determine factors associated with age-disparate sexual partners among Vancouver gay, bisexual and other men who have sex with men (GBM). METHODS: Sexually active GBM aged ≥16 years were recruited from February 2012 to February 2014. Participants self-completed a questionnaire on demographics, attitudes and sexual behaviour and substance use at last sexual event with five most recent partners. Two generalised linear mixed models identified factors associated with: (1) 'same-age' (referent), 'younger' or 'much-younger' and (2) 'same-age' (referent), 'older' or 'much-older' partners. Statistical interactions between age and HIV status were tested. RESULTS: Participants (n=719) were predominantly gay (85.1%), White (75.0%), HIV-negative/unknown status (72.9%) with median age of 33 years (Q1,Q3: 26,47). A minority of sexual events were reported with much-older/much-younger partners (13.7%). In the multivariable models, GBM reporting older partners were more likely to be Asian or Latino, have greater Escape Motivation scores, report their partner used erectile dysfunction drugs (EDDs) and have received something for sex; compared with condom-protected insertive anal sex, participants with older partners were more likely to report condomless insertive anal sex with a serodiscordant or unknown status partner or no insertive anal sex. GBM reporting older partners were less likely to be bisexual-identified, have given something for sex and report event-level alcohol and EDD use. GBM reporting younger partners were more likely to have annual incomes >$30 000 and have met their partner online. As per significant statistical interactions, age-disparate relations were more common for younger HIV-positive and older HIV-negative GBM. CONCLUSIONS: Differences among age-disparate partners highlight important targets for health promotion and future research.

Awareness and use of nonoccupational post-exposure prophylaxis among men who have sex with men in Vancouver, Canada.

OBJECTIVES: Nonoccupational post-exposure prophylaxis (nPEP) is a strategy to reduce the risk of HIV infection in those with high-risk exposure. This study characterized nPEP awareness among gay, bisexual and other men who have sex with men (MSM) in Metro Vancouver, British Columbia, Canada after a pilot nPEP programme established in 2012. METHODS: Momentum Health Study participants were MSM aged ≥16 years recruited via respondent-driven sampling (RDS) who completed a computer-assisted self-interview. Stratifying patients by HIV status, we used multivariable logistic regression with backward selection to identify factors associated with nPEP awareness. All analyses were RDS-adjusted. RESULTS: A total of 51.9% (112 of 173) of HIV-positive and 48.5% (272 of 500) of HIV-negative participants had heard of nPEP. Only 3% (five of 106) of HIV-negative participants who reported recent high-risk sex used nPEP. Generally, nPEP awareness was higher for participants who engaged in sexual activities with increased HIV transmission potential. Factors associated with greater awareness among HIV-negative participants included recent alcohol use, higher communal sexual altruism, previous sexually transmitted infection diagnosis, and greater perceived condom use self-efficacy. Other factors associated with greater awareness among HIV-negative participants included white race/ethnicity, gay sexual identity, more formal education, lower personal sexual altruism, and Vancouver residence. Greater nPEP awareness among HIV-positive participants was associated with greater perceived agency to ask sexual partners' HIV status and more frequently reporting doing so, a higher number of lifetime receptive sex partners, and greater access to condoms. CONCLUSIONS: Following implementation of an nPEP pilot programme, nPEP awareness among HIV-negative MSM was 51% and use was 3%. These data support the need to expand access to and actively promote nPEP services.

Branched isomeric 1,2,3-triazolium-based ionic liquids: new insight into structure-property relationships.

A series of four isomeric 1,2,3-triazolium-based ionic liquids (ILs) with vary degree of branching were synthesized and characterized to investigate the effect of ion branching on thermal and physical properties of the resulting IL. It was found that increased branching led to a higher ionicity and higher viscosity. The thermal properties were also altered significantly and spectral changes in the near edge X-ray absorption fine structure (NEXAFS) spectra show that branching affects intermolecular interaction. While the ionicity and viscosity varying linearly with branching, the MDSC and NEXAFS measurements show that the cation shape has a stronger influence on the melting temperature and absorptive properties than the number of branched alkyl substituents.

Associations of Perceived Discrimination With Impaired Functioning in a Population Sample With Psychological Distress.

OBJECTIVE: To test associations between perceived discrimination based on mental health status and impaired functioning in a population sample with psychological distress. METHODS: Interviews were conducted with a sample of respondents to the California Health Interview Survey with mild, moderate, or severe psychological distress. Perceived discrimination was assessed using 14 items covering four domains in which discrimination is reported: social, partner, institutional, and work. Associations of perceived discrimination scores (total score and domain scores) with impaired functioning, measured by the likelihood and number of days out of role, were estimated with statistical adjustment for demographic characteristics and serious psychological distress. RESULTS: Discrimination domain scores are significantly correlated (r ranging from .34 to .65).Total discrimination score is associated with having days out of role (OR = 1.20, 95% CI = 1.10-1.30) and with number of days out of role (5.5 days) after adjustment for demographics and psychological distress. The high correlation among the domain scores makes the attribution of association to particular domains uncertain. Removal of the effect of discrimination using model-based simulation reduces past-year days out of role by 39.4 (SE 11.3) days. CONCLUSIONS: This observational study supports the suggestion that discrimination against people with mental illness contributes to their impaired functioning in a diverse range of social roles. The results provide preliminary evidence that reduction in discrimination against people with mental illness could improve social functioning and work productivity. Correlations among domain scores make it difficult to draw conclusions about domain-specific associations.

Drug-plasma protein binding in Kutchin Athapaskan indians.

Free fractions of diazepam (D alpha), warfarin (W alpha), and methadone (M alpha) were measured in plasma obtained from 37 Kutchin Athapaskan Indians. Mean D alpha (3.42%) varied directly with free fatty acid concentration (r = 0.65, P less than 0.001) and was higher than previously found in other groups. These higher levels of fatty acids were associated with lower W alpha (r = -0.43, P = 0.007), and W alpha rose with time after a meal (r = 0.42, P = 0.01) when fatty acids usually fall. Mean W alpha was 0.72% and increased with age (r = 0.47, P = 0.004). In multivariate analysis, age, fatty acids, and time after the last meal together accounted for 42% of intersubject variation in W alpha. W alpha and D alpha were inversely correlated (r = -0.33, P = 0.04), a result of the strong effects of fatty acids in these drugs. In contrast to both D alpha and W alpha, intersubject differences in M alpha correlated inversely with alpha 1-acid glycoprotein concentration (r = -0.50, P = 0.001), but not fatty acids.

Children's understanding of psychiatric hospitalization.

The authors summarize the results of what they believe to be the first systematic study of children's concepts of their own psychiatric hospitalization. They found that children 6-12 years old are able to gain progressive insight into their problems and the roles that therapeutic staff (doctors and nurses) play in treatment. These findings provide new information about the child's point of view and cognitive understanding of psychiatric hospitalization, illness, and treatment. The findings suggest that preadmission legal hearings addressing the child's understanding of the nature of psychiatric hospitalization would not be meaningful.

Inkjet printing for high-throughput cell patterning.

The adaptation of inkjet printing technology to the complex fields of tissue engineering and biomaterial development presents the potential to increase progress in these emerging technologies through the implementation of this high-throughput capability via automated processes to enable precise control and repeatability. In this paper, a method of applying high-throughput inkjet printing to control cellular attachment and proliferation by precise, automated deposition of collagen is presented. The results indicate that commercial inkjet printing technology can be used to create viable cellular patterns with a resolution of 350 microm through the deposition of biologically active proteins. This method demonstrates a combination of off-the-shelf inkjet printing and biomaterials and has potential to be adapted to tissue engineering and colony patterning applications. Adapting this method into the three-dimensional construction of cellular structures for eventual high-throughput tissue engineering using a bottom-up approach is possible.

Sedentism and child health among Rendille pastoralists of northern Kenya.

Many nomadic pastoralists of Africa are settling near towns and famine-relief centers in response to drought-induced livestock loss, loss of pasture land, increased involvement in market economies and political turmoil including civil war. The present study uses measurements of child health, particularly morbidity, dietary and growth patterns, to evaluate the consequences of sedentism for three Rendille communities of northern Kenya. A nutritional and health survey utilizing interviews, anthropometric measurements, physical examinations and hemoglobin measurements was conducted for 105 mothers and their 174 children under six years of age in three Rendille communities, one fully nomadic and two sedentary, in July 1990, a year of above average rainfall, and again in June 1992, a drought year. Results indicate that while the nomadic Rendille community of Lewogoso shares similar morbidity patterns with its sedentary counterparts and had similar numbers of malnourished children during the wet year, the sedentary communities had significantly more malnutrition among children under six during the dry year. Moreover, the children in the settled town of Korr had significantly higher levels of anemia. Differences in malnutrition are attributed to distinctive dietary regimes: during the drought, nomadic children consumed three times as much milk as the sedentary children, while settled children's diets concentrated on starches, fat and sugar. This study suggests that the pastoral nomadic diet, particularly one dependent on camels' milk, offers children better resistance to the pressures of drought and supports findings that the subsistence base of mixed-species pastoralism is superior to sedentary alternatives with respect to child health.

Severe local hypothermia from laparoscopic gas evaporative jet cooling: a mechanism to explain clinical observations.

BACKGROUND AND OBJECTIVES: Explanations for laparoscopic-induced hypothermia fail to explain clinical observations. It is possible that water evaporation occurs from the jet stream of gas inflation resulting in tissue surface super-cooling leading to tissue damage and drying. METHODS: Theoretical calculations based on thermal conductivity, mass transfer effects and heat flux considerations correlated closely with synthetic and tissue experiments. Thermocouple measurements at a rate of 15 data points per second were performed. RESULTS: Cooling rates of 10 to 25 degrees centigrade per second for high flow rates were found based on gas flow rate and effective size of gas delivery site. These rapid temperature drops extended beyond a 2 cm2 diameter. CONCLUSIONS: Evaporative cooling accounts for significant hypothermia. The cooling is dependent on the lack of water vapor in the gases currently used during laparoscopy. Cooling rates are independent of height from tissue and geometry of delivery port. Heating and hydrating the gas to a physiologic condition eliminates hypothermia and tissue dessication.

Demography and computer simulation in historic village population reconstruction.

"Demographic anthropology has given rise to methodological advances in the analysis of single community populations. However, the obstacles of small data bases and incomplete vital-event registration remain. This paper details one approach to these problems; the principles of community demography are incorporated with computer simulation methodology, with the goals of validating the internal consistency of and determining demographic secular trends from data commonly utilized in anthropological investigations." The approach is tested on data for the 250 inhabitants of Old Crow Village, Yukon Territory, Canada, in 1978.

The delineation of fertility strategies in a tribal population of India: the Koyas of Koraput District, Orissa.

PIP: Demographic data collected for a tribal population of India, the Koyas of Koraput District, Orissa, were examined in light of 2 models of reproductive behavior associated with the economic value of children: the replacement effect and son survivorship motivation. Both models are united in the concept that infant/child mortality affects subsequent fertility. The database consists of retrospective fertility histories of Koya women who had completed their reproductive period. The total number was 260, with the total offspring numbering 1407. 2 distinct cohorts of women were formed for the purpose of analysis, separated only by the criterion of offspring survival: women who had experienced infant child mortality (129 women with 739 children); and women who completed their reproductive period without suffering offspring loss of this nature (132 women with 668 children). The cohort without child loss had a mean parity of 5.10, lower than the average parity of 5.73 recorded for the cohort whose reproductive histories included at least 1 infant/child death. Age specific marital fertility and birth interval analyses indicated that this differential was because of biological, not behavioral, factors. The age pattern of fertility of females suffering offspring mortality failed to demonstrate a high rate of childbearing in the later age intervals of the reproductive period, a characteristic pattern of couples attempting to "replace" lost offspring. Birth interval analysis pointed to biological "interval effect," whereby infant/child mortality caused a cessation of lactation and hence a shortening of postpartum amenorrhea. Computer simulation further indicated that the higher fertility differential of the cohort experiencing offspring loss still did not result in high son survivorship values. The findings agree with earlier studies indicating that for predemographic transitional populations, economically motivated fertility strategies are ineffectual.^ieng

Proximate and distal variables in the demography of Rendille pastoralists.

PIP: Following the widespread application and success of Bongaarts¿ proximate fertility framework in the 1980s, anthropologists and demographers have shown increased interest in the delineation of distal fertility variables, alternatively called ¿higher-order¿ variables by cultural ecologists or ¿ultimate¿ variables by evolutionary ecologists. This shift in focus raises at least four immediate issues: 1) confusion over the role and effect of culture on individual members¿ behavior; 2) whether the individual or group forms the basic unit of analysis; 3) discordance between external and internal perspectives of demographic regimes; and 4) difficulty comparing and evaluating quantitative survey-based data with qualitative information derived from focus groups or key informants. To solve these issues, this paper presents one approach that features the assessment of anthropological and demographic data collected for Rendille pastoralists of northern Kenya. The approach stresses the potential for interplay between aggregate patterns of demographic events, most commonly represented by proximate variable analysis of survey-derived data, and qualitative data arising from key informants or small focus groups.^ieng

Drought and economic differentiation among Ariaal pastoralists of Kenya.

PIP: In 1985, anthropologists interviewed stock owners from 38 households in Lewogoso Lukumai settlement in northern Kenya which were the same households studied in 1976 to determine whether the 1984 drought increased wealth differences between the rich and poor in this community of Ariaal pastoralists. They compared the 1985 post drought herd size and species specific losses to the 1976 predrought counts. Rich households tended to be polygynous, had large herd sizes, and more camels and cattle. The results confirmed that the drought did indeed reduce herd size. Camels were less likely to die than were cattle and small stock (goats and sheep) 18.3% died vs. 51.2% and 49.8% respectively. Poor households tended to own small stock. Large stock represented wealth and prestige. The rich experienced the most loss of animals, yet they did not have the same adverse consequences as did the poor. As a result of the drought, the number of poor households rose from 7-15 and the number of sufficient status households from 12-15. Only 8 of the 19 original rich households remained rich. Yet none of the 11 remaining families became poor following the drought. Yet, of the original 11 sufficient households, 67% became poor and all of the original poor households remained poor. In addition to differential herd composition and differential herd loss, differential participation in the case market resulted brought about considerable urban migration. Thus drought did not equalize household inequalities but indeed exacerbated them.^ieng

Indian tribal fertility patterns from Orissa.

PIP: Researchers used 1954 vital statistics from 23 villages of the Juang tribe in Orissa, India to determine if the historic view of a distinctive marital fertility pattern maintains tribal fertility differentials and to test the hypothesis that the death of an infant or child brings about a quick return of fecundity through cessation of lactation. They also examined demographic data collected in the 1980s from the Koya Dora tribe in Orissa, India and such data on Bangladeshi women. The Juang population had a total marital fertility rate of about 6 and a life expectancy at birth of 35.9 years. The Juangs had a higher proportion of 15-19 year old married women than the Koya Doras (17.4% vs. 12%). Further the Juangs exhibited a higher index of proportion married than the Koya Doras (97% vs. 87%). The researchers also compared the biological interval effect for pre and postmenopausal Koya Dora women, Bangladeshi women, and Juan women. For Juan Women, the interval of live births that resulted in infant or child mortality was 31.9 months compared to 36.9 months for those that resulted in survival (p.001). The biological replacement effect stood at 0.14. The biological replacement effect for pre and postmenopausal Koya Dora women and Bangladeshi women were 0.25, 0.32, and 0.28 respectively. In conclusion, the 2 leading factors for Juang fertility included almost universal marriage and early marriage and birth spacing dependent upon child survival or mortality.^ieng

Demography of the Juang tribal population of Orissa.

Demographic analysis of genealogical data collected in 1954 for 23 Juang villages was undertaken employing indirect estimation techniques and computer projection methodology. Results indicated that this group did not feature the historically high fertility levels associated with Indian tribal groups, although fertility was higher than previously reported for the Juang. The population did feature a mortality differential, with worse mortality conditions than the Indian national population at this time. Reversed sexual mortality differentials, common in South Asian populations, were also present for the Juang. Computer projection investigation revealed a steadily growing population, in contrast to some Indian tribal groups faced with extinction.

Child mortality levels and survival patterns from southern Sudan.

Data from a 1985 survey in two major population centres in Southern Sudan, Juba and Wau, were analysed in order to assess childhood mortality levels and the effect of UNICEF's health care programme. There are continuing high levels of childhood mortality. Logistic regression analysis shows significant positive associations between child survival and immunization, oral rehydration therapy and maternal education.

PIP: Data from a 1985 survey in 2 urban centers in Sudan, Juba and Wau, were analyzed to assess childhood mortality levels and the effect of UNICEF's health care program. A sample of 5120 mothers (Juba, 3061 and Wau, 2059) with 21,509 children were collected from the towns. Logistic regression analysis was used to delineate determinants of child survival. The child mortality measures denote continued high infant and child mortality levels for Southern Sudan. 3 components of the UNICEF program were significantly associated with child survival: oral rehydration therapy, maternal education and immunization. The study concludes that maternal education is the most important determinant of child survival, affecting both the cure and prevention of child ill- health. (Author's modified).