Analysis of metabolic flux in felid spermatozoa using metabolomics and 13C-based fluxomics†.

Spermatozoa from three feline species-the domestic cat (Felis catus), the cheetah (Acinonyx jubatus), and the clouded leopard (Neofelis nebulosa)-were analyzed using metabolomic profiling and 13C-based fluxomics to address questions raised regarding their energy metabolism. Metabolic profiles and utilization of 13C-labeled energy substrates were detected and quantified using gas chromatography-mass spectrometry (GC-MS). Spermatozoa were collected by electroejaculation and incubated in media supplemented with 1.0 mM [U13C]-glucose, [U13C]-fructose, or [U13C]-pyruvate. Evaluation of intracellular metabolites following GC-MS analysis revealed the uptake and utilization of labeled glucose and fructose in sperm, as indicated by the presence of heavy ions in glycolytic products lactate and pyruvate. Despite evidence of substrate utilization, neither glucose nor fructose had an effect on the sperm motility index of ejaculated spermatozoa from any of the three felid species, and limited entry of pyruvate derived from these hexose substrates into mitochondria and the tricarboxylic acid cycle was detected. However, pathway utilization was species-specific for the limited number of individuals (four to seven males per species) assessed in these studies. An inhibitor of fatty acid beta-oxidation (FAO), etomoxir, altered metabolic profiles of all three felid species but decreased motility only in the cheetah. While fluxomic analysis provided direct evidence that glucose and fructose undergo catabolic metabolism, other endogenous substrates such as endogenous lipids may provide energy to fuel motility.

Rates and determinants of HIV-attributable mortality among rural female sex workers in Northern Karnataka, India.

Female sex workers (FSWs) have among the highest rates of HIV infection in India. However, little is known about their HIV-specific mortality rates. In total, 1561 FSWs participated in a cohort study in Karnataka. Outcome data (mortality) were available on 1559 women after 15 months of follow-up. To gather details on deaths, verbal autopsy (VA) questionnaires were administered to key informants. Two physicians reviewed the VA reports and assigned underlying causes of death. Forty-seven deaths were reported during the follow-up (overall mortality rate was 2.44 per 100 person-years), with VA data available on 45 women. Thirty-five (75.6%) of these women were known to be HIV-positive, but only 42.5% were on antiretroviral therapy (ART). Forty deaths were assessed to be HIV-related, for an HIV-attributable mortality rate of 2.11 deaths per 100 person-years. Absence of a current regular partner (incidence rate ratio: 2.79; 95% confidence interval [CI]: 1.39-5.60) and older age (1.06; 1.01-1.11) were associated with increased HIV-attributable mortality. Reported duration in sex work was not related to HIV-attributable mortality. We found a high HIV-related mortality rate among this cohort of FSWs; nearly 10 times that of national mortality rates among women of a similar age group. Older age, but not reported duration in sex work, was associated with increased mortality, and suggests HIV acquisition prior to self-reported initiation into sex work. Despite significant efforts, there remain considerable gaps in HIV prevention near or before entry into sex work, as well as access and uptake of HIV treatment among FSWs.

High-risk sex among mobile female sex workers in the context of jatras (religious festivals) in Karnataka, India.

Jatras (religious festivals) represent venues for female sex workers (FSWs) to meet potential clients in an environment of anonymity. Data from a survey conducted among 1499 mobile FSWs in Karnataka, India were analysed using bivariate and multivariate analysis. Overall, 31% of mobile FSWs reported attending jatras in the previous year. Women who sold sex at jatras tended to practice sex work in public places, in their own homes or on highways. Jatra attendees reported lower condom use with their last commercial sexual partners at their usual places of sex work. Jatra-related mobility was a significant predictor of non-condom use at their usual place of residence, after controlling for sociodemographic, sex work-related, HIV vulnerability and programme exposure variables. Moreover, only 13% of FSWs used condoms consistently at jatras. Condom availability and accessibility at jatras should be a priority for HIV prevention programmes, and such programmes should make efforts to introduce outreach activities at jatras.

The role of collectives in STI and HIV/AIDS prevention among female sex workers in Karnataka, India.

This paper evaluates the role of female sex worker (FSW) collectives in the state of Karnataka, India, regarding their facilitating effect in increasing knowledge and promoting change towards safer sexual behaviour. In 2002 a state-wide survey of FSWs was administered to a stratified sample of 1,512 women. Following the survey, a collectivization index was developed to measure the degree of involvement of FSWs in collective-related activities. The results indicate that a higher degree of collectivization was associated with increased knowledge and higher reported condom use. Reported condom use was higher with commercial clients than with regular partners or husbands among all women and a gradient was observed in most outcome variables between women with low, medium and high collectivization index scores. Collectivization seems to have a positive impact in increasing knowledge and in empowering FSWs in Karnataka to adopt safer sex practices, particularly with commercial clients. While these results are encouraging, they may be confounded by social desirability, selection and other biases. More longitudinal and qualitative studies are required to better understand the nature of sex worker collectives and the benefits that they can provide.

Factors influencing continuation of IUD use in south India: evidence from a multivariate analysis.

This paper studies the correlates of IUD continuation, particularly in relation to quality of service provided in Karnataka, South India, by using a discrete-time logit model. Provision of follow-up services had a moderate influence on continuation, and medical check-up at insertion influenced the experience of side effects. But these effects were trivial in comparison with the overriding influence of motivational variables and of reported side effects. The IUD is retained for a limited duration in rural India where it is used mainly as a spacing device by lowly motivated young women who discontinue the method at the slightest feeling of discomfort or abnormality. If the IUD were recommended to older women for limiting childbearing by emphasizing its reversibility, it would enhance the method's popularity and improve the levels of contraceptive use among younger women.

PIP: In northern Karnataka, South India, the IUD is the most popular reversible contraceptive method but has a low continuation rate. The determinants of this pattern, with special emphasis on the role of programmatic factors, were investigated through an analysis of data from several small-scale follow-up studies of family planning acceptors conducted by the Population Research Center. A total of 713 IUD acceptors (461 rural and 252 urban) were interviewed in these studies. The mean age of IUD acceptors was 25 years; they averaged 2.3 children. 75% of rural and 58% of urban respondents had selected the IUD for spacing reasons. 45% reported IUD-related side effects such as irregular bleeding. Only 35% of respondents had their original IUD in situ at the time of follow-up and 57% had requested removal, primarily because of side effects. A multinomial logit model identified the level of motivation to use the method and the experience of real or perceived side effects as the most significant determinants of IUD continuation; unexpectedly, the quality of services provided before and after insertion was not as influential. Medical check-ups at insertion moderately reduced the experience of side effects. Women who selected the IUD for child spacing had significantly higher discontinuation rates at 3 months and were more likely to complain about side effects than those who chose the method for other reasons. A policy shift toward recommending the IUD to older, high-parity women for limiting purposes should be considered. Such a strategy might encourage contraceptive use among women who do not want more children but are concerned about child mortality and thus reluctant to undergo sterilization.

A comparative study of immigrant and non-immigrant families in Canada with special reference to income, 1986.

PIP: "A comparison of immigrant and non-immigrant families in Canada based on unpublished data from the 1986 Census of Canada indicates that immigrant families have stronger family ties and higher income than their nonimmigrant counterparts. This could be partly because immigrant families contain higher proportions of their members at prime working ages, higher proportions with three or more employment income recipients and higher proportions working full year full time.... The multivariate analysis of family income indicates that age and family type have overwhelming effects and that place of birth is third in importance." (EXCERPT)^ieng

Visible minority fertility in Canada, 1981-1986.

PIP: This study uses Canadian vital records and the 1981 and 1986 census to analyze levels and trends in fertility among minorities during 1981-86. The number of births for 1981 and 1986 were derived by averaging the annual number of births by birthplace and age of the mother over the periods 1980-82 and 1985-87. The authors calculated age specific fertility rates, the total fertility rate, and the mean age of the mother by birth place for Canada and regions by visible minority group for 1981 and 1986. Visible minority groups include Chinese, Indian/Pakistani, other Asians, Latin Americans, Caribbeans, and Africans. Regions include Maritime Provinces, Quebec, Ontario, and other provinces. Findings indicate that Canadian-born mothers had the lowest fertility rates in 1981 and 1986. The highest fertility rate in 1981 was 2.7 children/woman among other Asians, followed by 2.6 children/woman among Indians or Pakistanis. The Chinese had the lowest fertility rate of 1.8 children/woman. In 1986, the highest fertility was 2.5 children/woman among the Indians or Pakistanis, followed by 2.4 children/woman among the Chinese and Latin Americans. The lowest fertility was 2.2 children/woman among other Asians. Fertility rates varied widely during 1981 compared to 1986. Fertility declined for all minorities, with the exception of the Chinese and Africans. Fertility variations were greatest for the Chinese during 1981-86 and smallest for the Canadian-born. The mean age of childbearing increased by more than a year, with the exception of Chinese women, where the mean age decreased. The highest mean age was among Latin American women in 1981 and among other Asians in 1986. Other Asians had the highest relative index of total fertility. In 1986, minority women, excluding Chinese and African women, living in Quebec had the highest fertility. Caribbean-born women living in other provinces had lower fertility than Canadian-born women.^ieng

Land development and transmigrant farmers in Southern Sumatra, Indonesia.

"This paper discusses...the impact of land ownership on the transmigrant farmer's participation in new land development for irrigated paddy fields, taking Lampung Province (the pioneer settlement of the transmigration programme) as the specific area of reference. Special attention is focused on the case of the Way Rarem Irrigation Project in the northern part of Lampung, Southern Sumatra.... There is no evidence in this analysis to support the hypothesis that the income level of the farmer contributes to the progress of land development. The ethnicity or province of origin is also insignificant in its effect on land development. Similarly, transmigration status does not show any significant relation to land development." (SUMMARY IN FRE AND SPA)

The seasonality of births in Canada.

Earlier studies on the seasonality of births indicate that a major peak occurs in August and September and a minor peak in January and February. This study uses the 1984 Canadian Fertility Survey data on reproductive history to examine birth and pregnancy seasonalities, and shows that the 'worst' months for births are January and February and the 'best' months are March, April and May. There is no systematic pattern in the seasonality of pregnancies, possibly because effective birth control allows couples to plan the timing of births.

Spouse selection in Canada, 1921-78: an examination by age, sex and religion.

PIP: This paper presents time series data on spouse selection in Canada for the period 1921-1978. Homogamous and endogamous trends are examined by age, sex, and religion. In the case of religious endogamy, most groups have shown decreasing proportions of marriages. There are also considerable differences in rates of endogamy among religious groups, and these differences have largely persisted over time. Until 1971, the proportions of brides marrying older and younger grooms decreased, while the proportion marrying the same age increased, after which these trends reversed. Younger males increasingly tended to select brides of their own age group until the 1960s, while older males have been increasingly heterogamous since World War II. While these changes in spouse selection have been examined with respect to changes in the unmarried population, the relation between the 2 trends is not clear, and it is difficult to account fully for the observed trends in spouse selection with respect to age.^ieng

Dynamics of fertility and labour force participation of Canadian women in 1971 and 1981: a cohort approach.

The authors analyze the relationship between labor force participation and fertility in Canada using data from the Public Use Sample Tapes from the 1971 and 1981 censuses. Factors considered include age, religion, educational status, and marital status. The authors conclude that "labour force participation of women seems to have less influence on fertility compared to [the] fertility effect on labour force participation."

Ethnic fertility differences in Canada, 1926-71: an examination of assimilation hypothesis.

PIP: The changing pattern of fertility differences among ethnic groups in Canada during the period 1926-71 is studied. 2 specific questions are addressed. The 1st is do ethnic groups assimilate the fertility patterns of the general Canadian population over time, e.g. are the fertility differences disappearing? Secondly, is the extent of assimilation in fertility greater in urban than in rural areas? The indirectly standardized general fertility rates, calculated by using the ethnic age distribution data from the censuses of 1931 to 1971, indicate a tendency for the population to become more homogeneous during times of increasing fertility, thus supporting the assimilative possibilities, whereas in times of declining fertility there is a tendency for the population to become more heterogeneous. The data also seem to support weaker assimilatory tendencies in rural areas than in urban areas during only the most recent period, 1966-71, and not in earlier periods.^ieng

Ethnicity and migration in Canada.

"This study focuses on the relationship between ethnicity and geographic mobility in Canada by examining 1971 census data. Several competing hypotheses are extracted from the literature on the social demography of ethnic and minority groups and evaluated for their efficacy in explaining the observed differences in geographic mobility. The results from a multivariate analysis suggest that the causal mechanisms involving ethnic, characteristic factors and the propensity to move are varied and interconnected; hence, both ethnic and social demographic characteristics are important sources of migration differentials. The article concludes by providing a theoretical model for further examination of ethnicity and migration."