Influence of social stability on the sex determination process in false clown anemonefish (Amphiprion ocellaris)

ABSTRACT

To evaluate the involvement of plasma cortisol in sex determination in hermaphrodite protandrous sex-changing fish, sexually immature false clown anemonefish (Amphiprion ocellaris) were kept in groups of 3 individuals for 360 days. Observations of time-course changes of diurnal behaviour and plasma concentrations of cortisol, oestradiol, and 11-ketotestosterone were evaluated. The social hierarchy of the experimental groups was assumed to become stable during the middle period of the experiment, but unstable at the beginning and at the end according to the increase or decrease in the frequencies of agonistic behaviours. The plasma concentration of cortisol increased as the social hierarchy became unstable and oestradiol showed the opposite trend to cortisol. These results suggest that in protandrous anemonefish sex determination induced by social interaction is mediated by cortisol. The stability of the social hierarchy is considered to be very important for the sex determination process.     

A comparative study of determinants of uxorilocal marriage in two counties of China

Abstract

A strictly maintained patrilineal family system makes virilocal marriage almost universal and uxorilocal marriage rare in the history of rural China. Uxorilocal marriage can be divided into two types that may be termed, respectively, contingent and institutional. The former preserves family lineages in families without a son and occurs when uxorilocal marriage is uncommon. The latter serves practical economic purposes in families with sons and occurs when uxorilocal marriage is relatively prevalent. Using data from a survey in two counties of Shaanxi—Lueyang, where both kinds of uxorilocal marriage are prevalent, and Sanyuan, where uxorilocal marriage is rare and usually contingent—this paper employs logistic regression models in a quantitative comparative study of determinants of uxorilocal marriage in rural China. We show that the purposes and prevalence of the two types of uxorilocal marriage differ and that their determinants are also different in the two counties. In Sanyuan, the determinants are only a couple's sibling composition, membership in a large family clan, and educational level. In Lueyang, in addition to those determinants in Sanyuan, important contributions to the type of uxorilocal marriage include a couple's parental marriage type, age at marriage, adoption status, marriage arrangement, and their attitudes toward uxorilocal marriage. The results indicate the potential importance of encouraging uxorilocal marriage in rural areas as a means of mitigating demographic and social problems related to son preference, such as high sex ratio at birth and lack of old‐age security, which are projected for China's future.     

The influence of cultural factors on the demography and pattern of gene flow from the Makiritare to the Yanomama Indians

A single village of Yanomama Indians was found to have frequencies of Di^a of 0.06 and of Ap^a of 0.08, in contrast to 40 other villages whereDi^a was absent and Ap^a quite rare. The source of these genes was identified as a village of Makiritare Indians, but the two allele frequencies were approximately the same or even higher in the Yanomama than in the Makiritare village. Demographic, social and cultural parameters affecting marriage and reproduction in the two tribes explain this. Genealogical relationships and informants' accounts collected in the field, when viewed against the traditional marriage practices, reproductive advantages of headmen, and differential treatment of captured women, indicate that the mating and reproduction parameters inherent in tribal social organization of this kind constitute an essential part of the explanation of the genetic findings. It is argued that mating systems of this sort are such that the probability of a new gene introduced by a captive surviving in the recipient population is a function of the sex of the initial carrier. The implications for tribalization and potentially radical changes in allele frequencies are briefly explored by considering aspects of settlement pattern and population fissioning known to characterize the tribes in question. Finally, it is shown that genetic sampling from a single location can and does result in unrepresentative allele frequencies when this single sample is taken to characterize the tribe as a whole.     

Characteristics of Resting-State Functional Connectivity in HIV-Associated Neurocognitive Disorder

BackgroundHIV-associated neurocognitive disorder (HAND) can occur in patients without prior AIDS defining illness and can be debilitating. This study aimed to evaluate the difference in the patterns of intrinsic brain activity between patients with or without HAND for deepening our understanding of HAND.MethodsWe evaluated 24 HIV-infected individuals, 12 with previously diagnosed HAND and 12 previously diagnosed without HAND, and 11 seronegative individuals. These individuals then underwent repeat NP testing and a functional brain MRI scan. For functional MRI analysis, seed-based analysis with bilateral precuneus cortex seed was applied.ResultsAmong the 12 individuals with previously diagnosed HAND, 3 showed improvement of their neurocognitive function and 1 was excluded for worsening liver disease. Among the 12 patients who previously had normal neurocognitive function, 2 showed neurocognitive impairment. Overall, the HAND group, who had impaired cognitive function at the time of MRI scan, showed significant decrease of resting status functional connectivity between bilateral precuneus and prefrontal cortex (PFC) compared with nonHAND group, those who had normal neurocognitive function (Corrected P<0.05). The functional connectivity with the right inferior frontal operculum and right superior frontal gyrus was positively correlated with memory and learning ability.ConclusionsThis cross-sectional study found a significant difference in fMRI patterns between patients with and without HAND. Decreased functional connectivity between precuneus and PFC could be possible functional substrate for cognitive dysfunction in HIV patients, which should be characterized in a longitudinal study.     

Same Sex Marriage and the Perceived Assault on Opposite Sex Marriage

Background

Marriage benefits both individuals and societies, and is a fundamental determinant of health. Until recently same sex couples have been excluded from legally recognized marriage in the United States. Recent debate around legalization of same sex marriage has highlighted for anti-same sex marriage advocates and policy makers a concern that allowing same sex couples to marry will lead to a decrease in opposite sex marriages. Our objective is to model state trends in opposite sex marriage rates by implementation of same sex marriages and other same sex unions.

Methods and Findings

Marriage data were obtained for all fifty states plus the District of Columbia from 1989 through 2009. As these marriage rates are non-stationary, a generalized error correction model was used to estimate long run and short run effects of same sex marriages and strong and weak same sex unions on rates of opposite sex marriage. We found that there were no significant long-run or short run effects of same sex marriages or of strong or weak same sex unions on rates of opposite sex marriage.

Conclusion

A deleterious effect on rates of opposite sex marriage has been argued to be a motivating factor for both the withholding and the elimination of existing rights of same sex couples to marry by policy makers–including presiding justices of current litigation over the rights of same sex couples to legally marry. Such claims do not appear credible in the face of the existing evidence, and we conclude that rates of opposite sex marriages are not affected by legalization of same sex civil unions or same sex marriages.     

Social and biological determinants of age at first marriage in Taiwan, 1970

Abstract

This study examines the social and biological determinants of age at first marriage in two townships in northern Taiwan, one very rural and traditional and the other urban and modernized. For a sample of 5,707 once‐married women a path analysis was performed in which age at first marriage was considered a function of age, educational attainment, urban origin, premarital labor‐force participation, and age at menarche. Age at menarche, with a positive effect on the dependent variable, was the most important direct cause of age at first marriage. Although exogenous variables associated with modernization (urban origin, educational attainment and younger age) had a positive direct effect on age at first marriage, they also had a negative indirect effect on age at first marriage through their negative direct effect on age at menarche.     

Evaluating Sex and Gender Competencies in the Medical Curriculum: A Case Study

BackgroundSex and gender differences exist in the manifestation and prevalence of many conditions and diseases. Yet many clinician training programs neglect to integrate this information across their curricula.ObjectiveThis study aimed to measure the sex and gender medical knowledge of medical students enrolled in a program without an explicit directive to integrate sex and gender differences across a block system of core subjects.MethodsA forced-choice instrument consisting of 35 multiple-choice and true or false questions was adapted from an evaluation tool used in the European Curriculum in Gender Medicine held at Charité Hospital, Berlin, in September 2010.ResultsFourth-year (response rate 93%) and second-year (response rate 70%) students enrolled in Mayo Medical School completed the instrument. More than 50% of students in both classes indicated that topics related to sex and gender were covered in gynecology, cardiology, and pediatrics, and <20% of students indicated inclusion of such topics in nephrology, neurology, and orthopedics. More than twice as many second-year students indicated that topics dealing with sex and gender were included in immunology course material compared with fourth-year students. A consensus of written comments indicated that concepts of sex and gender-based medicine need to be embedded into existing curriculum, with an emphasis on clinically relevant information.ConclusionsAlthough this study represents only one medical school in the United States, information regarding sex and gender aspects of medicine is not consistently included in this curriculum without an explicit directive. These results can provide guidance for curriculum improvement to train future physicians.     

Microhabitat use and social structure in Linnet Carduelis cannabina and Corn Bunting Miliaria calandra at a winter roost in central Spain

Capsule Both species selected particular patches for roosting, and Linnets but not Corn Buntings showed a social structure with males occupying the preferred roosting positions.

Aims To evaluate microhabitat preferences of Linnet and Corn Bunting within a winter communal roost, and to examine roost structure according to sex, age and body size.

Methods We captured Linnets and Corn Buntings along a habitat gradient in a reed-bed in central Spain when they were coming to roost. Each bird was sexed, aged, and several body traits were measured. We also characterized the habitat patches where the birds were trapped and grouped patches according to their similarity.

Results Three groups of patches were defined according to reed structure. Linnets preferred patches with low density of high and thick shoots, while Corn Buntings preferably used patches with intermediate values for these variables. Interspecific competition for preferred positions was not evident. Male Linnets were proportionately more abundant in the preferred patches, and individuals in lower body condition, independent of sex, age or body size, occupied the non-preferred patches. Male Corn Buntings were less abundant, bigger in size, and showed better condition than females, although differences in body size and condition were not apparent among patches within the roost.

Conclusion Our results suggest that among-patch differences in structure and location within a reed-bed generate microhabitats that differ in quality for roosting passerines. This habitat heterogeneity in turn seems to be responsible for the social spatial structure observed in Linnets, in which females and individuals in poor physiological condition were displaced, possibly through competition, towards non-preferred positions. The relatively small body size of Linnets compared to Corn Buntings might explain Linnets' preference for patches that seem to provide more protection against harsh weather conditions.     

The marriage squeeze in Colombia, 1973–2005: The role of excess male death

Abstract

Colombia has been characterized by extreme levels of civil violence throughout the latter part of the twentieth century, and the burden of excess mortality attributable to this violence has been borne primarily by young men. Populations with a large violent death burden are likely to experience consequences in terms of (1) marriage markets, (2) the dynamics of family formation and dissolution, and (3) patterns of parental investment in offspring. Using data from national censuses and household surveys, we calculate a measure of the marital sex ratio in order to explore the impact of differential male mortality on marriage markets in Colombia. Overall, Colombia is characterized by a female biased sex ratio at all ages. This relative excess of women is particularly pronounced in certain departments of the Central and Pacific regions which have been especially affected by civil violence. We suggest that the low sex ratios which characterized Colombia are partially responsible for the increasingly high frequency of consensual unions and, potentially, female‐biased rural‐urban migration.     

Clinical implications of genetic susceptibility to diabetes mellitus

Abstract

Relatively little attention has been given to the interpretation of age‐at‐marriage differences in fertility. This paper discusses possible demographic and sociological sources of this differential. The argument is made that sociological interpretations deserve increased attention since most of the observed differential persists after control for likely demographic components (premarital pregnancy, unwanted fertility, and subfecundity) and for correlated social and background variables (education of self and parents, religion, farm background, number of siblings, whether respondent's parental family was intact, and husband's age at marriage). Multiple‐classification analysis is employed. The analysis concludes by noting that age at first birth has an even stronger relationship with fertility than age at marriage and that the sociological dimensions of age relevant to age at marriage are even more appropriate to age at entrance into motherhood.     

Book notes

Abstract

Marriage in Indian society is a religious duty. Consanguineous marriage is common, where individuals prefer to marry within their clan (a unilateral kin group based on either matrilineal or patrilineal descent). Keeping in mind that this form of marriage has certain disadvantages for social and biological as well as demographic aspects of individuals and families, the present study examines the influence of mate selection (i.e., close relatives, distant relatives, not related) on female age at marriage, pregnancy wastages, and survival status of the first child. The study was designed based on the information collected on a sample size of 3,948 married women aged 13–49 in Tamil Nadu, India, by the National Family Health Survey (NFHS), 1992. Results suggest that 48 per cent of women in Tamil Nadu marry their relatives. This practice of marrying relatives is high in rural areas, among Hindus, Scheduled Castes/tribes, and illiterate women as compared to urban areas, among non‐Hindus, non‐SC/ST, and educated women, respectively. The bivariate analysis reveals that women marrying their close relatives had low age at marriage and experienced a higher per cent of pregnancy wastage and child loss (first child) as compared to those women marrying their distant relatives or nonrelatives. The result is found to be consistent even after controlling for selected background variables through multivariate techniques (applied separately for age at marriage, pregnancy wastages, and the survival status of first child). Hence, this study suggests that steps should be taken to inform people about the problems of marrying close relatives through appropriate IEC programs in Tamil Nadu.     

Proximal Spacing Between Individuals in a Group of Woolly Monkeys (Lagothrix lagotricha) in Tinigua National Park, Colombia

I studied proximal spacing within a group of woolly monkeys (Lagothrix lagotricha) during 7 months at Parque Nacional Tinigua, Colombia. I collected a total of 1188 instantaneous samples on focal individuals, recording the number and age/sex class of individuals that were in contact with, <2 m from, <5 m from the focal animal. The results indicate that proximate spacing reflects social affinities and is related to mother–infant relationship and social grooming. Subadult females and adult males are the sex/age classes with the lowest number of individuals in proximity. There are low proximity between adult females and between adult males and high frequencies of nearness between mother and offspring. Associations between males and females were usually low, but in some cases males showed preferences for a given female. There was a relatively gradual increase in spacing between mothers and their offspring as they became older. Old juvenile males were associated chiefly with other males—mostly subadults—whereas juvenile females maintained some proximity only to their mothers. There are also differences in spacing behavior according to different activity types.     

High serum riboflavin is associated with the risk of sporadic colorectal cancer

BackgroundExperimental results indicate that riboflavin is involved in tumorigenesis. Data regarding the relationship between riboflavin and colorectal cancer (CRC) are limited, and findings vary between observational studies.DesignThis was a case–control retrospective study.ObjectiveThis study aimed to evaluate the associations between serum riboflavin level and sporadic CRC risk.MethodsIn total, 389 participants were enrolled in this study – including 83 CRC patients without family history and 306 healthy controls – between January 2020 and March 2021 at the Department of Colorectal Surgery and Endoscope Center at Xinhua Hospital, Shanghai Jiao Tong University School of Medicine. Age, sex, body mass index, history of polyps, disease conditions (e.g., diabetes), medications, and eight other vitamins were used as confounding factors. Adjusted smoothing spline plots, subgroup analysis, and multivariate logistic regression analysis were conducted to estimate the relative risk between serum riboflavin levels and sporadic CRC risk. After fully adjusting for the confounding factors, an increased risk of colorectal cancer was suggested for individuals with higher levels of serum riboflavin (OR = 1.08 (1.01, 1.15), p = 0.03) in a dose–response relationship.ConclusionsOur results support the hypothesis that higher levels of riboflavin may play a role in facilitating colorectal carcinogenesis. The finding of high levels of circulating riboflavin in patients with CRC warrants further investigation.     

The effects of social isolation on steroid hormone levels are modulated by previous social status and context in a cichlid fish

Social isolation is a major stressor which impacts the physiology, behaviour and health of individuals in gregarious species. However, depending on conditional and contextual factors, such as social status and group composition, social isolation may be perceived differently by different individuals or even by the same individuals at different times. Here we tested the effects of social status (territorial vs. non-territorial) and previous group composition (i.e. type of social group: mixed sex group with two territorial males, TT vs. mixed sex group with one territorial and one non-territorial male, TnT) on the hormonal response (androgens and cortisol) to social isolation in a cichlid fish (Oreochromis mossambicus). The different steroid hormones measured responded differentially to social isolation, and their response was modulated by social factors. Social isolation elicited a decrease of 11-keto formation only in territorial males, whereas non-territorial males present a non-significant trend for increasing KT levels. Testosterone did not respond to social isolation. Cortisol only increased in isolated individuals from TnT groups irrespective of social status (i.e. both in territorials and non-territorials). These results suggest that it is the perception of social isolation and not the objective structure of the situation that triggers the hormonal response to isolation.     

Habitat Patch Size,Facultative Monogamy and Sex Change in a Coral-dwelling Fish, <Emphasis Type="Italic">Caracanthus unipinna</Emphasis>

Synopsis We investigated the inter-relationships between coral colony size, social group size, mating system, and patterns of sex allocation in the pygmy coral croucher, Caracanthus unipinna (Caracanthidae), an obligate coral-dwelling fish. Histological examination of the gonads from all individuals in social groups revealed that the predominant mating system was harem polygyny. However, both group size and mating system co-varied with coral colony size, with pair forming and monogamy occurring on small corals and group forming and harem polygyny on large corals. This species therefore displays mating system plasticity in response to varying habitat patch size. Within-group sexual size dimorphism and individual gonad structure indicate that C. unipinna is also likely to be a protogynous hermaphrodite. These social and reproductive features of C. unipinna contrast with some other coral-dwelling fishes, which display a lack of social and mating system plasticity in response to habitat patch size, and either bi-directional or protandrous sex change. Possible reasons for this dichotomy include differences in spawning mode, parental care and levels of intrasexual aggression.     

Association between Polymorphism of the Interleukin-13 Gene and Susceptibility to Hepatocellular Carcinoma in the Chinese Population

ObjectiveInterleukin-13 (IL-13) is a potent pleiotropic cytokine that is produced by activated CD4 T cells. This study was undertaken to determine the relationship between two IL-13 gene single nucleotide polymorphisms (SNP rs1800925 and SNP rs20541) and the incidence of hepatitis B virus-related (HBV) hepatocellular carcinoma (HCC).MethodThree hundred and ninety-eight HBV-positive individuals (192 HCC and 206 patients with chronic hepatitis) and one hundred and ninety-two healthy participants from the First Affiliated Hospital of Guangxi Medical University were enrolled in this study.ResultsThe results showed no significant differences between the genotype and allele frequencies of the IL-13 gene rs1800925 and rs20541 polymorphisms and chronic hepatitis B risk after adjusting for age, sex, tobacco use, and alcohol intake using binary logistic regression analyses. Regarding the rs20541 SNP, the GA genotype was significantly related to a decreased risk of HCC after adjusting for age, sex, tobacco use, and alcohol intake using binary logistic regression analyses (The odds ratio (OR) = 0.54, 95% confidence intervals (CI) 0.34–0.87). The adjusted OR for the GA and AA genotypes combined was 0.68 (95% CI 0.39–0.90).ConclusionThis study indicates that the functional IL-13 rs20541 polymorphism may contribute to the risk of HCC and that the rs20541 polymorphism is a protective factor for HCC.     

Understanding the High Prevalence of HIV and Other Sexually Transmitted Infections among Socio-Economically Vulnerable Men Who Have Sex with Men in Jamaica

ObjectivesThis study estimates HIV prevalence among men who have sex with men (MSM) in Jamaica and explores social determinants of HIV infection among MSM.DesignAn island-wide cross-sectional survey of MSM recruited by peer referral and outreach was conducted in 2011. A structured questionnaire was administered and HIV/STI tests done. We compared three groups: MSM who accepted cash for sex within the past 3 months (MSM SW), MSM who did not accept cash for sex (MSM non-SW), and MSM with adverse life events (ever raped, jailed, homeless, victim of violence or low literacy).ResultsHIV prevalence among 449 MSM was 31.4%, MSM SW 41.1%, MSM with adverse life events 38.5%, 17 transgender MSM (52.9%), and MSM non-SW without adverse events 21.0%. HIV prevalence increased with age and number of adverse life events (test for trend P < 0.001), as did STI prevalence (P = 0.03). HIV incidence was 6.7 cases/100 person-years (95% CI: 3.74, 12.19). HIV prevalence was highest among MSM reporting high-risk sex; MSM SW who had been raped (65.0%), had a STI (61.2%) and who self identified as female (55.6%). Significant risk factors for HIV infection common to all 3 subgroups were participation in both receptive and insertive anal intercourse, high-risk sex, and history of a STI. Perception of no or little risk, always using a condom, and being bisexual were protective.ConclusionHIV prevalence was high among MSM SW and MSM with adverse life events. Given the characteristics of the sample, HIV prevalence among MSM in Jamaica is probably in the range of 20%. The study illustrates the importance of social vulnerability in driving the HIV epidemic. Programs to empower young MSM, reduce social vulnerability and other structural barriers including stigma and discrimination against MSM are critical to reduce HIV transmission.     

Movements,status, access to nectar,and spatial organisation of the tui

Abstract

Movements of tui (Prosthetnadera novaeseelandiae) breeding on Tiritiri Matangi Island were followed and related to changes in nectar access. The island has limited nectar sources and birds must move to gain access to nectar year round. All tui leave the island, although the extent and timing of movement varies for different individuals. Tui return for breeding but again the timing of the return varies for individuals. Nectar sources were typically concentrated in both time and space, and access was related to individual asymmetries such as sex, residential status and age. These same asymmetries also relate to the timing of individuals movements, and where individuals nest relative to nectar sources. At concentrated food sources, access was determined by an absolute social hierarchy. Although tui defend exclusive feeding territories, breeding territories are not exclusive and access to nectar is determined by distance to nest site. Such variability in spatial organisation is related to a continuum concept of social organisation.     

Book review: Advances in Human Palaeopathology

Severe dental wear and tooth loss is often assumed to impede the processing, breakdown, and energetic conversion of food items, thereby negatively impacting individual health, reproduction, and survival. Ring‐tailed lemurs at the Beza Mahafaly Special Reserve demonstrate exceptionally high frequencies of severe dental wear and antemortem tooth loss, yet often survive multiple years with these impairments. To test the hypothesis that these lemurs mitigate tooth loss through behavioral adjustments, we collected 191 h of observational data from 16 focal subjects, eight without tooth loss and eight with between 3% and 44% loss. These data indicate dentally‐impaired ring‐tailed lemurs show compensatory behaviors consistent with the demands of living in a social group. During early afternoon (12:00–14:30 h) individuals with loss showed trends towards higher frequencies of foraging and grooming, while individuals without loss rested significantly more often. Individuals with >10% loss (n = 7) showed higher frequencies of feeding, foraging, and grooming, and lower frequencies of resting during this period than individuals with <10% loss (n = 9). Individuals with tooth loss maintained relatively higher levels of feeding and foraging throughout the day. These individuals licked tamarind fruit at higher frequencies, likely spending more time softening it before ingestion. These individuals did not demonstrate longer feeding bouts overall, although bouts involving tamarinds were significantly longer. Individuals with marked toothcomb wear engaged in higher rates of certain types of allogrooming, demonstrating that social behaviors are used to compensate for reduced grooming efficiency. These data have implications for interpreting behavioral responses to dental impairment in the fossil record. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.