The genetic structure of Drosophila ananassae populations from Asia, Australia and Samoa.
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Information about genetic structure and historical demography of natural populations is central to understanding how natural selection changes genomes. Drosophila ananassae is a widespread species occurring in geographically isolated or partially isolated populations and provides a unique opportunity to investigate population structure and molecular variation. We assayed microsatellite repeat-length variation among 13 populations of D. ananassae to assess the level of structure among the populations and to make inferences about their ancestry and historic biogeography. High levels of genetic structure are apparent among all populations, particularly in Australasia and the South Pacific, and patterns are consistent with the hypothesis that the ancestral populations are from Southeast Asia. Analysis of population structure and use of F-statistics and Bayesian analysis suggest that the range expansion of the species into the Pacific is complex, with multiple colonization events evident in some populations represented by lineages that show no evidence of recent admixture. The demographic patterns show isolation by distance among populations and population expansion within all populations. A morphologically distinct sister species, D. pallidosa, collected in Malololelei, Samoa, appears to be more closely related to some of the D. ananassae populations than many of the D. ananassae populations are to one another. The patterns of genotypic diversity suggest that many of the individuals that we sampled may be morphologically indistinguishable nascent species. (+info)
Birth order and male androphilia in Samoan fa'afafine.
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The manner in which male androphilia is publicly expressed varies cross-culturally. As such, it is unclear whether distinct or common underlying causal processes characterize male androphilia in different cultures. Establishing the existence of cross-cultural universals in male androphilia is one means of ascertaining whether common biological bases underlie this phenomenon despite its culturally distinct forms. The evidence that the number of older biological brothers increases the odds of androphilia in later-born males has been well documented for Western samples (i.e. the fraternal birth order effect); but there is little evidence for this effect in non-Western samples. Here, we compare the birth order of androphilic males (i.e. fa'afafine) and gynephilic males from the politically autonomous Polynesian nation of Independent Samoa. Results indicate that relative to gynephilic males, fa'afafine tend to have more siblings and are generally later born when birth order is quantified using Slater, fraternal and sororal indices. More specifically, fa'afafine tend to have a greater number of older brothers, older sisters and younger brothers. We discuss the observed effects in relation to the differing reproductive patterns exhibited by the mothers of fa'afafine and gynephilic males, and to existing social and biological theories for sexual orientation. (+info)
Haemophilus ducreyi causing chronic skin ulceration in children visiting Samoa.
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Chancroid is a sexually transmitted infection associated with genital ulceration and lymphadenopathy caused by Haemophilus ducreyi. Localized skin infections, in the absence of genital lesions, have not been previously reported. We report 3 cases of lower limb ulceration in children caused by H. ducreyi and postulate that H. ducreyi may be a previously unrecognized cause of chronic skin ulceration. (+info)
Extraordinary flux in sex ratio.
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The ratio of males to females in a species is often considered to be relatively constant, at least over ecological time. Hamilton noted that the spread of "selfish" sex ratio-distorting elements could be rapid and produce a switch to highly biased population sex ratios. Selection against a highly skewed sex ratio should promote the spread of mutations that suppress the sex ratio distortion. We show that in the butterfly Hypolimnas bolina the suppression of sex biases occurs extremely fast, with a switch from a 100:1 population sex ratio to 1:1 occurring in fewer than 10 generations. (+info)
Pacific Islanders' perspectives on heart failure management.
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OBJECTIVE: To identify the health beliefs, attitudes, practices, and social and family relations important in heart failure treatment among Pacific Islanders. METHODS: Four focus groups were convened with 36 Native Hawaiians and Samoans with heart failure and their family caregivers. Thematic data analysis was used to categorize data into four domains: health beliefs and attitudes, preferred health practices, social support systems, and barriers to heart failure care. RESULTS: Common coping styles and emotional experiences of heart failure in this population included avoidance or denial of illness, hopelessness and despair, and reliance on spiritual/religious beliefs as a means of support. Among study participants, more Samoans preferred to be treated by physicians whereas more Native Hawaiians preferred traditional Hawaiian methods of healing. Two types of social support (informational and tangible-instrumental) were identified as important in heart failure care. Barriers to heart failure care included poor knowledge of heart failure, lack of trust in physicians' care, poor physician-patient relations, finances, dietary changes, and competing demands on time. CONCLUSION: The recruitment, retention, and adherence of Pacific Islanders to heart failure interventions is affected by an array of psychosocial and socio-cultural factors. PRACTICE IMPLICATIONS: Interventions might be improved by offering participants accurate and detailed information about heart failure and its treatment, engaging the extended family in providing necessary supports, and providing tools to facilitate physician-patient relationships, among others, within the context of a larger socio-cultural system. (+info)
Results of a randomized trial to increase mammogram usage among Samoan women.
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BACKGROUND: There are no effective breast cancer education programs targeting Samoan women. We tested the effectiveness of a theory-guided, culturally appropriate breast cancer education program (the intervention) designed to increase mammography use among Samoan women. METHODS: This community-based participatory cluster-randomized controlled intervention trial used a parallel two-group design. The sample consisted of 776 women aged 42 and older who had not had a mammogram in the preceding 2 years. The primary outcome was self-reported mammogram use between pretest and posttest. RESULTS: Overall, there was no statistically significant intervention effect, although the odds of self-reported mammogram use were higher in the intervention than the control group (odds ratio (OR), 1.26; 95% confidence interval (95% CI), 0.74, 2.14; P = 0.39). Exploratory subgroup analyses found that the intervention was effective only among women who were aware of mammograms but had never previously obtained one (OR, 1.99; 95% CI, 1.03, 3.85; P = 0.04). Low need for social support and lack of endorsement of culture-specific beliefs about breast cancer were associated with mammogram use in this group. In women unaware of mammography at pretest, high perceived susceptibility to breast cancer and endorsement of culture-specific beliefs were associated with mammogram use. For women who had previously obtained a mammogram, lower self-efficacy was associated with mammogram use. Intervention compared with control group women had significantly higher levels of knowledge of risk factors and lower endorsement of culture-specific beliefs at posttest. CONCLUSIONS: Results suggest that a multifaceted education intervention may improve mammogram usage for certain subgroups of Samoan women. (+info)
Impact of traditional Samoan lifestyle (fa'aSamoa) on cancer screening practices.
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