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  1. Age, Sex, and Telomere Dynamics in a Long-Lived Seabird with Male-Biased Parental Care

    PubMed Central

    Young, Rebecca C.; Kitaysky, Alexander S.; Haussmann, Mark F.; Descamps, Sebastien; Orben, Rachael A.; Elliott, Kyle H.; Gaston, Anthony J.

    2013-01-01

    The examination of telomere dynamics is a recent technique in ecology for assessing physiological state and age-related traits from individuals of unknown age. Telomeres shorten with age in most species and are expected to reflect physiological state, reproductive investment, and chronological age. Loss of telomere length is used as an indicator of biological aging, as this detrimental deterioration is associated with lowered survival. Lifespan dimorphism and more rapid senescence in the larger, shorter-lived sex are predicted in species with sexual size dimorphism, however, little is known about the effects of behavioral dimorphism on senescence and life history traits in species with sexual monomorphism. Here we compare telomere dynamics of thick-billed murres (Urialomvia), a species with male-biased parental care, in two ways: 1) cross-sectionally in birds of known-age (0-28 years) from one colony and 2) longitudinally in birds from four colonies. Telomere dynamics are compared using three measures: the telomere restriction fragment (TRF), a lower window of TRF (TOE), and qPCR. All showed age-related shortening of telomeres, but the TRF measure also indicated that adult female murres have shorter telomere length than adult males, consistent with sex-specific patterns of ageing. Adult males had longer telomeres than adult females on all colonies examined, but chick telomere length did not differ by sex. Additionally, inter-annual telomere changes may be related to environmental conditions; birds from a potentially low quality colony lost telomeres, while those at more hospitable colonies maintained telomere length. We conclude that sex-specific patterns of telomere loss exist in the sexually monomorphic thick-billed murre but are likely to occur between fledging and recruitment. Longer telomeres in males may be related to their homogamous sex chromosomes (ZZ) or to selection for longer life in the care-giving sex. Environmental conditions appeared to be the

  2. Sex and age differences in hibernation patterns of common hamsters: adult females hibernate for shorter periods than males.

    PubMed

    Siutz, Carina; Franceschini, Claudia; Millesi, Eva

    2016-08-01

    In this study, we investigated the timing and duration of hibernation as well as body temperature patterns in free-ranging common hamsters (Cricetus cricetus) with regard to sex and age differences. Body temperature was recorded using subcutaneously implanted data loggers. The results demonstrate that although immergence and vernal emergence sequences of sex and age groups resembled those of most hibernators, particularly adult females delayed hibernation onset until up to early January. Thus, in contrast to other hibernators, female common hamsters hibernated for shorter periods than males and correspondingly spent less time in torpor. These sex differences were absent in juvenile hamsters. The period between the termination of hibernation and vernal emergence varied among individuals but did not differ between the sex and age groups. This period of preemergence euthermy was related to emergence body mass: individuals that terminated hibernation earlier in spring and had longer euthermic phases prior to emergence started the active season in a better condition. In addition, males with longer periods of preemergence euthermy had larger testes at emergence. In conclusion, females have to rely on sufficient food stores but may adjust the use of torpor in relation to the available external energy reserves, whereas males show a more pronounced energy-saving strategy by hibernating for longer periods. Nonetheless, food caches seem to be important for both males and females as indicated by the euthermic preemergence phase and the fact that some individuals, mainly yearlings, emerged with a higher body mass than shortly before immergence in autumn. PMID:27138337

  3. High-glucose diets have sex-specific effects on aging in C. elegans: toxic to hermaphrodites but beneficial to males.

    PubMed

    Liggett, Marjorie R; Hoy, Michael J; Mastroianni, Michael; Mondoux, Michelle A

    2015-06-01

    Diet and sex are important determinants of lifespan. In humans, high sugar diets, obesity, and type 2 diabetes correlate with decreased lifespan, and females generally live longer than males. The nematode Caenorhabditis elegans is a classical model for aging studies, and has also proven useful for characterizing the response to high-glucose diets. However, studies on male animals are lacking. We found a surprising dichotomy: glucose regulates lifespan and aging in a sex-specific manner, with beneficial effects on males compared to toxic effects on hermaphrodites. High-glucose diet resulted in greater mobility with age for males, along with a modest increase in median lifespan. In contrast, high-glucose diets decrease both lifespan and mobility for hermaphrodites. Understanding sex-specific responses to high-glucose diets will be important for determining which evolutionarily conserved glucose-responsive pathways that regulate aging are "universal" and which are likely to be cell-type or sex-specific. PMID:26143626

  4. Sentencing Male Sex Offenders Under the Age of 14: A Law Reform Advocacy Journey in Hong Kong.

    PubMed

    Ng, Wai-Ching Irene; Cheung, Monit; Ma, Anny Kit-Ying

    2015-01-01

    The common law presumption that a boy under the age of 14 is incapable of sexual intercourse has provoked controversial debates in Hong Kong. This article describes a 6-step advocacy journey to examine how community efforts have helped modify this law so that juvenile male sexual offenders under the age of 14 who have committed the crime of having sexual intercourse with underage females can be sentenced to receive appropriate treatment. Seven court cases provided by the magistrates' courts in Hong Kong were used in this advocacy effort for the removal of the presumption in July 2012. Although this effort has yet to reveal signs of effectiveness, it represents greater public awareness about providing rehabilitation appropriate for juvenile sex offenders through a formal sentence. Restorative justice, as opposed to retributive or punitive justice, places an emphasis on rehabilitation of the offender and restoration of victims to a place of wholeness. PMID:26061020

  5. Sex Steroid Actions in Male Bone

    PubMed Central

    Laurent, Michaël R.; Claessens, Frank; Gielen, Evelien; Lagerquist, Marie K.; Vandenput, Liesbeth; Börjesson, Anna E.; Ohlsson, Claes

    2014-01-01

    Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority. PMID:25202834

  6. Sexual Experience Changes Sex Hormones But Not Hypothalamic Steroid Hormone Receptor Expression in Young and Middle-aged Male Rats

    PubMed Central

    Wu, Di; Gore, Andrea C.

    2009-01-01

    Testosterone is well known to regulate sexual behavior in males, but this is dependent upon prior sexual experience. Aging is associated with decreased libido and changes in testosterone, but the role of experience in these age-related processes has not been systematically studied. We examined effects of age and sexual experience on serum hormones (total testosterone, free testosterone, estradiol, LH) and on numbers of androgen receptor (AR) and estrogen receptor α (ERα) immunoreactive cells in the hypothalamus. Extensive sexual experience was given to male rats at 4 months of age. Rats were euthanized at either 4 months (young) or 12 months (middle-aged (MA)). Comparable sexually naïve male rats were handled and placed into the testing arena but did not receive any sexual experience. Thus, we had four groups: young-naïve, young-experienced, MA-naïve and MA-experienced. Serum hormone levels were assayed, and numbers of AR and ERα cells were quantified stereologically in the medial preoptic nucleus (MPN) and the anteroventral periventricular nucleus (AVPV). Sexually experienced males had significantly elevated serum testosterone and free testosterone in both age groups. Both total and free testosterone were higher, and estradiol lower, in middle-aged than young rats. Experience did not alter either AR or ERα expression in the preoptic brain regions studied. Aging was associated with increased expression of AR, but no change in ERα. These results show that sexual experience can induce short-term and long-term alterations in serum hormones but these effects are not manifested upon their receptors in the hypothalamus. PMID:19559704

  7. Sex-specific parental care strategies via nestling age: females pay more attention to nestling demands than males do in the horned lark, Eremophila alpestris.

    PubMed

    Liu, Chang-Jing; Du, Bo; Liu, Nai-Fa; Bao, Shi-Jie; Zhang, Shengxiang

    2014-06-01

    In many species, nestling demands vary continuously during early development and both parents have different parental care strategies at each nestling age. Sexual conflict arises when each parent expects its partner investing more in parental care. It is largely unknown how the two parents respond to the dynamics of nestling demands and resolve the sexual conflict during nestling period, especially on Qinghai-Tibetan Plateau. To address this question, we monitored parental care behaviors of horned larks (Eremophila alpestris) using video-recording systems. We found that male horned larks invested less in parental care, but had a larger body size than females, which is consistent with the parental investment hypothesis. Only the female brooded nestlings, but both parents contributed to feeding efforts. Feeding rates of males and females were negatively correlated, indicating that they used evolutionarily stable strategies. Strategies of parental care via nestling age were sex-specific. Females continuously adjusted care behaviors to follow the dynamics of nestling demands as nestling age increased, such as decreasing brood attentiveness and increasing feeding rate. By contrast, male feeding rate showed no significant correlation with nestling age, but increased with the synchrony feeding rate. We suggest the synchrony feeding behavior may act as a control measure for females to promote and assess the males' contribution. We consider low mating opportunities drive males to act as assistants for females, and correspondingly cause males to pay less attention to nestling demands than females. PMID:24882094

  8. Research directions in male sex work.

    PubMed

    Browne, J; Minichiello, V

    1996-01-01

    This paper provides a critical review of the literature relating to male sex work and outlines approaches to theorizing about and researching male sex work. The adequacy of these models to explain the male sex work industry is discussed. The literature reveals that earlier studies conceptualized male sex work as deviance and focused on the individual sex worker and his reasons for engaging in sex work. Although the research agenda has recently moved away from the individual sex worker towards the sex work industry, the focus of the investigation continues to be from a deviance rather than a work perspective. A number of aspects of male sex work have received little attention in the literature. These include the interpersonal dialogues and power relations that constitute the commercial sexual negotiation, the role of political and economic forces, and expressions of male sexuality within the practice of commercial sex. The paper suggests future research directions and argues that researchers need to draw on the strengths of the male sex work community in order to promote safe sex practices in commercial researchers need to draw on the strengths of the male sex work community in order to promote safe sex practices in commercial sexual settings. PMID:8905528

  9. Cigarette smoking and male sex are independent and age concomitant risk factors for the development of ocular sarcoidosis in a new orleans sarcoidosis population

    PubMed Central

    Janot, Adam C.; Huscher, Dörte; Walker, McCall; Grewal, Harmanjot K.; Yu, Mary; Lammi, Matthew R.; Saketkoo, Lesley Ann

    2016-01-01

    Introduction Sarcoidosis is a multi-organ system granulomatous disease of unknown origin with an incidence of 1–40/100,000. Though pulmonary manifestations are predominant, ocular sarcoidosis (OS) affects 25–50% of patients with sarcoidosis and can lead to blindness. Methods A retrospective, single-center chart review of sarcoidosis cases investigated variables associated with the development of OS. Inclusion criteria were biopsy-proven sarcoidosis, disease duration greater than 1 year, documented smoking status on chart review and documentation of sarcoid-related eye disease. Multivariate analysis identified independent risk factors for OS. Results Of 269 charts reviewed, 109 patients met inclusion criteria. The OS group had a significantly higher proportion of smokers (71.4%) than without OS (42.0%, p=0.027) with no difference (p=0.61) in median number of pack years. Male sex was significantly higher in the OS group (57.1% versus 26.1%, p=0.009). Median duration of sarcoidosis was higher in the OS group (10 versus 4 years, p=0.031). Multivariate regression identified tobacco exposure (OR=5.25, p=0.007, 95% CI 1.58–17.41), male sex (OR=7.48, p=0.002, 95% CI 2.15–26.01), and age (OR=1.114, p=0.002, 95% CI 1.04–1.19) as concomitant risk factors for the development of OS. Conclusion To date, there are few dedicated investigations of risk factors for OS, especially smoking. This investigation identified male sex, age, and tobacco exposure as independent risk factors for OS. Though disease duration did not withstand regression analysis in this moderately sized group, age at chart review suggests screening for OS should not remit but rather intensify in aging patients with sarcoidosis. PMID:26278693

  10. Sex-dependent nutritional programming: fish oil intake during early pregnancy in rats reduces age-dependent insulin resistance in male, but not female, offspring.

    PubMed

    Sardinha, Fatima L C; Fernandes, Flavia S; Tavares do Carmo, Maria G; Herrera, Emilio

    2013-02-15

    Prenatal and early postnatal nutritional status may predispose offspring to impaired glucose tolerance and changes in insulin sensitivity in adult life. The long-term consequences of changes in maternal dietary fatty acid composition were determined in rats. From day 1 until day 12 of pregnancy, rats were given isocaloric diets containing 9% nonvitamin fat based on soybean, olive, fish (FO), linseed, or palm oil. Thereafter, they were maintained on the standard diet; offspring were studied at different ages. Body weight at 4, 8, and 12 mo and lumbar adipose tissue and liver weights at 12 mo did not differ between females on the different diets, whereas in males the corresponding values were all lower in the offspring from the FO group compared with the other dietary groups. Plasma glucose concentrations (both basal and after an oral glucose load) did not change with sex or dietary group, but plasma insulin concentrations were lower in females than in males and, in males, were lowest in the FO group. Similar relations were found with both the homeostasis model assessment of insulin resistance and insulin sensitivity index. In conclusion, the intake of more n-3 fatty acids (FO diet) during early pregnancy reduced both fat accretion and age-related decline in insulin sensitivity in male offspring but not in females. It is proposed that the lower adiposity caused by the increased n-3 fatty acids during the intrauterine life was responsible of the lower insulin resistance in male offspring. PMID:23255588

  11. Sex chromosome aneuploidy and aging.

    PubMed

    Stone, J F; Sandberg, A A

    1995-10-01

    Loss of an X chromosome in females and of the Y chromosome in males are phenomena associated with aging. X chromosome loss occurs in and may be limited to PHA stimulated peripheral lymphocytes. In males, the loss of the Y is most evident in bone marrow cells, but also occurs to a lesser extent in PHA stimulated peripheral lymphocytes. X chromosome loss is associated with premature centromere division leading to anaphase lag and elimination in micronuclei. The mechanism of Y chromosome loss has not been elucidated. No pathological consequence of either X or Y chromosome loss has been convincingly demonstrated. With the advent of FISH technology, measurement of sex chromosome aneuploidy may prove to be a convenient assay for cellular senecence and aging. PMID:7565866

  12. Speech tempo and fundamental frequency patterns: a case study of male monozygotic twins and an age- and sex-matched sibling.

    PubMed

    Whiteside, Sandra P; Rixon, Emma

    2013-12-01

    This case study describes an investigation into the speaking characteristics of a set of male monozygotic (MZ) twins (T1 and T2) and an age- and sex-matched sibling (S). Measures of speech tempo and fundamental frequency (F0) were analysed in the speech samples of a reading passage. Results showed significant between-sibling differences for sentence durations and F0 parameters; however, Euclidean distance (ED) measures revealed the smallest distances between the F0 parameters of the MZ twins. The smallest ED values were also observed between T1 and T2 for word durations, pause durations, all-voiced sample durations, and all the all-voiced sample F0 parameters. Greater similarities were observed across all three siblings for the speech tempo and dynamic F0 parameters. PMID:23194081

  13. Is higher risk sex common among male or female youths?

    PubMed

    Berhan, Yifru; Berhan, Asres

    2015-01-01

    There are several studies that showed the high prevalence of high-risk sexual behaviors among youths, but little is known how significant the proportion of higher risk sex is when the male and female youths are compared. A meta-analysis was done using 26 countries' Demographic and Health Survey data from and outside Africa to make comparisons of higher risk sex among the most vulnerable group of male and female youths. Random effects analytic model was applied and the pooled odds ratios were determined using Mantel-Haenszel statistical method. In this meta-analysis, 19,148 male and 65,094 female youths who reported to have sexual intercourse in a 12-month period were included. The overall OR demonstrated that higher risk sex was ten times more prevalent in male youths than in female youths. The practice of higher risk sex by male youths aged 15-19 years was more than 27-fold higher than that of their female counterparts. Similarly, male youths in urban areas, belonged to a family with middle to highest wealth index, and educated to secondary and above were more than ninefold, eightfold and sixfold at risk of practicing higher risk sex than their female counterparts, respectively. In conclusion, this meta-analysis demonstrated that the practice of risky sexual intercourse by male youths was incomparably higher than female youths. Future risky sex protective interventions should be tailored to secondary and above educated male youths in urban areas. PMID:26726839

  14. Rogue Males: Sex Differences in Psychology Students

    ERIC Educational Resources Information Center

    Sander, Paul; Sanders, Lalage

    2006-01-01

    Introduction: This paper reports a preliminary study into the commitment and academic confidence of male students in undergraduate psychology, prompted by our own observations of the performance of male students and the literature on sex differences in education. Method: Using an analytical survey, level 1 psychology students at a new university…

  15. Male pygmy hippopotamus influence offspring sex ratio

    PubMed Central

    Saragusty, Joseph; Hermes, Robert; Hofer, Heribert; Bouts, Tim; Göritz, Frank; Hildebrandt, Thomas B.

    2012-01-01

    Pre-determining fetal sex is against the random and equal opportunity that both conceptus sexes have by nature. Yet, under a wide variety of circumstances, populations shift their birth sex ratio from the expected unity. Here we show, using fluorescence in situ hybridization, that in a population of pygmy hippopotamus (Choeropsis liberiensis) with 42.5% male offspring, males bias the ratio of X- and Y-chromosome-bearing spermatozoa in their ejaculates, resulting in a 0.4337±0.0094 (mean±s.d.) proportion of Y-chromosome-bearing spermatozoa. Three alternative hypotheses for the shifted population sex ratio were compared: female counteract male, female indifferent, or male and female in agreement. We conclude that there appears little or no antagonistic sexual conflict, unexpected by prevailing theories. Our results indicate that males possess a mechanism to adjust the ratio of X- and Y-chromosome-bearing spermatozoa in the ejaculate, thereby substantially expanding currently known male options in sexual conflict. PMID:22426218

  16. Identifying sex and age of akiapolaau

    USGS Publications Warehouse

    Pratt, T.K.; Fancy, S.G.; Harada, C.K.; Lindsey, G.D.; Jacobi, J.D.

    1994-01-01

    Methods for identifying the sex and age of the Akiapolaau (Hemignathus munroi), an endangered honeycreeper found only on the island of Hawaii, were developed by examination and measurement of 73 museum specimens and 24 live birds captured in mist nests. Akiapolaau probably undergo a single annual molt, with most birds molting between February and July. The mottled juvenal plumage is replaced by a first basic plumage characterized by yellowish-gray or yellowish-green underparts and often by retained wingbars. Male Akiapolaau may not attain adult plumage until their third molt. In adult females, only the throat and upper breast become yellow, whereas in adult males the superciliaries, cheeks, and entire underparts are yellow. Adult males have greater exposed culmen, gonys, wing chord, tail, and tarsus lengths than do females. Akiapolaau in first prebasic molt or older can be identified as to sex by culmen length, that of males being >23.4 mm.

  17. Sex differences in cardiovascular ageing.

    PubMed

    Merz, Allison A; Cheng, Susan

    2016-06-01

    Despite recent progress in identifying and narrowing the gaps in cardiovascular outcomes between men and women, general understanding of how and why cardiovascular disease presentations differ between the sexes remains limited. Sex-specific patterns of cardiac and vascular ageing play an important role and, in fact, begin very early in life. Differences between the sexes in patterns of age-related cardiac remodelling are associated with the relatively greater prevalence in women than in men of heart failure with preserved ejection fraction. Similarly, sex variation in how vascular structure and function change with ageing contributes to differences between men and women in how coronary artery disease manifests typically or atypically over the adult life course. Both hormonal and non-hormonal factors underlie sex differences in cardiovascular ageing and the development of age-related disease. The midlife withdrawal of endogenous oestrogen appears to augment the age-related increase in cardiovascular risk seen in postmenopausal compared with premenopausal women. However, when compared with intrinsic biological differences between men and women that are present throughout life, this menopausal transition may not be as substantial an actor in determining cardiovascular outcomes. PMID:26917537

  18. A comparison of sex offenders against female and male minors.

    PubMed

    Freund, K; Watson, R; Rienzo, D

    1987-01-01

    Male sex offenders against minors were grouped according to age and sex of victims, and according to whether they had offended against one or more than one minor. Cases of incest or courtship disorder were not included in the study. Among offenders against female children, the number of one-case offenders was substantially larger than that of multicase offenders. The opposite was true of offenders against male children, and there was no significant difference between one-case and multicase offenders against female or male early adolescents. If these counts reflect corresponding prevalences within sex offenders against minors in a Western cultural setting, some inferences can be made from these comparisons. PMID:3694689

  19. Determining age and sex of American coots

    USGS Publications Warehouse

    Eddleman, William R.; Knopf, Fritz L.

    1985-01-01

    Reliable techniques for age and sex determination of migrating and wintering American Coots (Fulica americana) have not been available. Breeding coots can be ages through age 3 by tarsal color (birds 4 years and older were placed in a 4+ age class) (Crawford 1978), and males and females have sex-specific behaviors and calls while on breeding territories (Gullion 1950, 1952). Externally, juvenile coots differ from adults in having gray (as opposed to white) bills and brown (as opposed to red) eyes to an age of 75 days (Gullion 1954-394). Bill color changes to white by about 120 days. No quantitative data have been available, however, on the proportion of juveniles retaining these traits throughout fall and early winter. Nonbreeding coots can be ages as juvenile or adult by internal examination of the thickness of the wall of the bursa of Fabricius, although bursal depth does not predictably decline with age (Fredrickson 1968). Attempts to sex coots by single external measurements of combinations of measurements have met with mixed success. Eight-five percent of 101 fall migrants in Wisconsin could be sexed by the length of the metatarsus-midtoe including claw by using 139.5 mm as a cutoff point (Burton 1959), whereas 88% of 67 coots in California were correctly sexed by the length of the metatarsus-midtoe without claw using 127.5 mm as the cutoff point (Gullion 1952). Two-hundred-thirty-two of 291 coots collected in Iowa, however, were in the zone of overlap between the sexes for this measurement (Fredrickson 1968). Previous studies attempting to develop aging and sexing techniques for American Coots have been limited to a few study sites or to 1 season or year, often failing to take geographical, annual, and seasonal morphological variation into account (e.g., Visser 1976, Fjeldsa 1977). We designed the present study to refine and quantify external and internal age and sex criteria for postbreeding coots, with the objective of defining techniques applicable for all

  20. Woodcock age and sex determination from wings

    USGS Publications Warehouse

    Martin, F.W.

    1964-01-01

    Age of woodcock (Philohela minor) can be accurately determined throughout the year by differences in pattern, color, and wear of secondary feathers. Immature woodcock retain most secondaries during the postjuvenal molt that begins in July or August and ends in October. In contrast, subadults (first-year adults) and older woodcock molt all secondaries during the postnuptial molt beginning in June or July and ending in October. Retention of juvenal secondaries by immatures and molt of these feathers by adults form the basis for age determination. Sex of woodcock can be accurately determined by width of the outer three primaries, which are conspicuously narrower on males.

  1. Sex differences in nutrient-dependent reproductive ageing.

    PubMed

    Maklakov, Alexei A; Hall, Matthew D; Simpson, Stephen J; Dessmann, Josephine; Clissold, Fiona J; Zajitschek, Felix; Lailvaux, Simon P; Raubenheimer, David; Bonduriansky, Russell; Brooks, Robert C

    2009-06-01

    Evolutionary theories of aging predict that fitness-related traits, including reproductive performance, will senesce because the strength of selection declines with age. Sexual selection theory predicts, however, that male reproductive performance (especially sexual advertisement) will increase with age. In both bodies of theory, diet should mediate age-dependent changes in reproductive performance. In this study, we show that the sexes exhibit dramatic, qualitative differences in age-dependent reproductive performance trajectories and patterns of reproductive ageing in the cricket Teleogryllus commodus. In females, fecundity peaked early in adulthood and then declined. In contrast, male sexual advertisement increased across the natural lifespan and only declined well beyond the maximum field lifespan. These sex differences were robust to deviations from sex-specific dietary requirements. Our results demonstrate that sexual selection can be at least as important as sex-dependent mortality in shaping the signal of reproductive ageing. PMID:19627271

  2. Age and Sex Differences in Interaction with a Human Infant.

    ERIC Educational Resources Information Center

    Blakemore, Judith E. O.

    1981-01-01

    Examines sex differences in vocalizations and play behaviors displayed toward an infant by preschoolers, preadolescents, and adults. Preschoolers showed less interaction than older subjects. Males talked and played less with the baby than did females at all ages; however, among adult subjects, no sex-role effects were found. (Author/RH)

  3. Sex and age identification of palila

    USGS Publications Warehouse

    Jeffrey, J.J.; Fancy, S.G.; Lindsey, G.D.; Banko, P.C.; Pratt, T.K.; Jacobi, J.D.

    1993-01-01

    Methods to sex and age Palila (Loxioides bailleui), an endangered Hawaiian finch restricted to subalpine woodlands on Hawai'i, were identified on the basis of measurements and plumage characteristics of 17 museum specimens and 96 known-age, live Palila. Palila undergo a single annual molt during September-December following the breeding season. Presence of a complete or partial wingbar distinguishes hatch-year and second-year Palila from after-second-year birds. Adult male Palila are distinguished from females by a distinct napeline and lt 30% gray feathers intermixed with yellow feathers on the head. The black or gray feathers of the lores and chin of males are darker than those on the back, whereas the lores and chin of females are lighter or of the same shade as back feathers.

  4. The female mid-life sex change applicant: a comparison with younger female transsexuals and older male sex change applicants.

    PubMed

    Roback, H B; Lothstein, L M

    1986-10-01

    This paper reports on a survey approach to the study of the aging (40 years of age and older) female requesting sex reassignment surgery (SRS). A profile of 13 cases presenting at a cross-section of gender identity clinics in North America is presented. The mid-life SRS applicant is also compared on selected characteristics with a younger female transsexual group and with the aging male sex change applicant. Findings suggest that the mid-life female SRS applicant is closely akin to the aging, conflicted homosexual, whereas the mid-life male SRS applicant appears more closely associated with the aging transvestite. PMID:3789904

  5. Age and sex identification of Akohekohe

    USGS Publications Warehouse

    Simon, John C.; Pratt, T.K.; Berlin, Kim E.; Kowalsky, James R.

    1998-01-01

    We present methods to determine the age and sex of Akohekohe (Palmeria dolei), an endangered Hawaiian honeycreeper, developed on the basis of 45 museum specimens and 91 live birds captured on the island of Maui. Akohekohe retained all Juvenal primaries, some Juvenal secondaries, and some body feathers after the first prebasic molt; they attained full adult plumage after the second prebasic molt. Retention of brown Juvenal body feathers, especially on the head, distinguished most birds in the first basic plumage from adults, which have a full complement of distinctive, black lanceolate body feathers with white, gray, or orange tips. Male Akohekohe were heavier than females and had longer wing, tail, and tarsometatarsus lengths. We present a linear discriminant function to sex both adults and juveniles using lengths of their wing and tarsometatarsus.

  6. Sex and Age Differences in the Endorsement of Sex Stereotypes Associated with Driving.

    PubMed

    Pravossoudovitch, Karyn; Martha, Cécile; Cury, François; Granié, Marie-Axelle

    2015-01-01

    Sex and age differences are particularly pronounced in car accidents. Current psychological research is exploring the relationship between risky driving and compliance with sex stereotypes, notably conformity with social expectations concerning masculinity. Some studies have already shown that sex stereotypes associated with driving (SSAD) may influence driving behaviors. The aim of this research was to explore the participants' sex and age differences in SSAD endorsement. A questionnaire was developed and validated on four dimensions of SSAD: male's driving skills and female's compliance with traffic rules, courtesy behind the wheel, and risk avoidance in driving. SSAD endorsement was measured for 291 licensed drivers from 18 to 64 years of age. Results revealed that females endorsed the female's risk avoidance stereotype more (p < .05), whereas males endorsed the male drivers (driving skills) stereotype more (p < .05). Results also revealed that the endorsement of male's driving skills decreases with age (p < .01) and the endorsement of female's courtesy increases with age among all participants (p = .01), while the endorsement of female's compliance with traffic rules increases with age only among female participants (p < .05). The results are discussed in terms of in-group/out-group relations and sex and age differences. PMID:26695552

  7. Male age mediates reproductive investment and response to paternity assurance

    PubMed Central

    Benowitz, Kyle M.; Head, Megan L.; Williams, Camellia A.; Moore, Allen J.; Royle, Nick J.

    2013-01-01

    Theory predicts that male response to reduced paternity will depend on male state and interactions between the sexes. If there is little chance of reproducing again, then males should invest heavily in current offspring, regardless of their share in paternity. We tested this by manipulating male age and paternity assurance in the burying beetle Nicrophorus vespilloides. We found older males invested more in both mating effort and parental effort than younger males. Furthermore, male age, a component of male state, mediated male response to perceived paternity. Older males provided more prenatal care, whereas younger males provided less prenatal care, when perceived paternity was low. Adjustments in male care, however, did not influence selection acting indirectly on parents, through offspring performance. This is because females adjusted their care in response to the age of their partner, providing less care when paired with older males than younger males. As a result offspring, performance did not differ between treatments. Our study shows, for the first time, that a male state variable is an important modifier of paternity–parental care trade-offs and highlights the importance of social interactions between males and females during care in determining male response to perceived paternity. PMID:23782889

  8. Sex Genotype and Sex Phenotype Contribute to Growth Differences Between Male and Female Channel Catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish have an XX:XY genotypic system of sex determination, and until the present study, the influence of sex genotype on growth could not be distinguished from sex phenotype. Genotypic male fish (XY) were produced by mating normal (XX) female fish with YY male fish. A subsample from eac...

  9. Understanding the New Context of the Male Sex Work Industry

    ERIC Educational Resources Information Center

    Scott, John; Minichiello, Victor; Marino, Rodrigo; Harvey, Glenn P.; Jamieson, Maggie; Browne, Jan

    2005-01-01

    The article reviews past and recent research on male sex work to offer a context to understand violence in the industry. It provides a critical review of research to show, first, the assumptions made about male sex workers and violence and, second, how such discourses have shaped thinking on the topic. The article presents a case study and…

  10. Sex behaviour of male Japanese tourists in Bangkok, Thailand.

    PubMed

    Yokota, Fumihiko

    2006-01-01

    This paper explores why Japanese men engage in potentially risky commercial sexual behaviours while on holiday in Thailand. Semi-structured, in-depth interviews were conducted with 30 heterosexual male Japanese tourists, aged 19-36, who paid for sex with Thai women. Study participants were recruited at guesthouses in Bangkok. Analysis revealed eight main factors that encourage participation in commercial sex: a sense of freedom and anonymity during "time-out" spent travelling in a foreign country; a sense that there are permissive norms governing commercial sex in Thailand; the perceived sexual desirability of Thai women, a sense of economic and racial superiority relative to Thai women; a sense of loneliness or feeling in need of companionship; peer influence; the widespread availability of inexpensive sexual services in Thailand; and sexual desire or need. Findings indicate that Japanese male sexual conduct reflects individual drives while on holiday, in the context of interactions among Japanese peers, shaped by Thailand's socio-cultural environment. PMID:16641061

  11. Aging changes in the male reproductive system

    MedlinePlus

    ... decreases. The level of the male sex hormone, testosterone stays the same or decreases gradually. There may ... less intense. This may be related to decreased testosterone level. It may also result from psychological or ...

  12. Prevalence and Behavioral Correlates of Depression and Anxiety Among Male Sex Workers in Vietnam

    PubMed Central

    Goldsamt, Lloyd A.; Clatts, Michael C.; Giang, Le Minh; Yu, Gary

    2015-01-01

    Objectives This study assessed depression and anxiety symptoms, and their association with high-risk sexual and drug behaviors, among male sex workers in three Vietnamese cities. Methods Male sex workers ages 16 to 35 completed an interview that included the CES-D to assess depressive symptoms and the BAI to assess anxiety symptoms, as well as questions assessing drug and sexual risk practices. Results A majority of participants reported depressive symptomatology although fewer report symptoms of anxiety. Risky sexual and drug use practices predicted both types of symptoms. Conclusions Mental distress is associated with drug and sexual risk among male sex workers. PMID:25984252

  13. Sex-different response in growth traits to resource heterogeneity explains male-biased sex ratio

    NASA Astrophysics Data System (ADS)

    Matsushita, Michinari; Takao, Mikako; Makita, Akifumi

    2016-08-01

    In dioecious plants, differences in growth traits between sexes in a response to micro-environmental heterogeneity may affect sex ratio bias and spatial distributions. Here, we examined sex ratios, stem growth traits and spatial distribution patterns in the dioecious clonal shrub Aucuba japonica var. borealis, in stands with varying light intensities. We found that male stems were significantly more decumbent (lower height/length ratio) but female stems were upright (higher height/length ratio). Moreover, we found sex-different response in stem density (no. of stems per unit area) along a light intensity gradient; in males the stem density increased with increases in canopy openness, but not in females. The higher sensitivity of males in increasing stem density to light intensity correlated with male-biased sex ratio; fine-scale sex ratio was strongly male-biased as canopy openness increased. There were also differences between sexes in spatial distributions of stems. Spatial segregation of sexes and male patches occupying larger areas than female patches might result from vigorous growth of males under well-lit environments. In summary, females and males showed different growth responses to environmental variation, and this seemed to be one of possible causes for the sex-differential spatial distributions and locally biased sex ratios.

  14. Patterns of ectoparasitism in North American red squirrels (Tamiasciurus hudsonicus): Sex-biases, seasonality, age, and effects on male body condition

    PubMed Central

    Patterson, Jesse E.H.; Neuhaus, Peter; Kutz, Susan J.; Ruckstuhl, Kathreen E.

    2015-01-01

    Within many species, males are often more heavily parasitised than females. Several hypotheses have been proposed to explain this phenomenon, including immunocompetence handicaps, sexual size dimorphism and behavioural differences. Here we set out to test the latter two hypotheses and make inferences about the former by assessing patterns of ectoparasitism across various life-history stages in a population of North American red squirrels (Tamiasciurus hudsonicus). We also conducted an ectoparasite removal experiment to investigate the effects of ectoparasites on male body condition. We found that males were more intensely parasitized than females, but only during the mating period. There was no difference in ectoparasite intensity between male and female juveniles at birth or at emergence, suggesting that ectoparasites do not exploit male red squirrels for longer-range natal dispersal. Male red squirrels in our population were slightly heavier than females, however we did not find any evidence that this dimorphism drives male-biased ectoparasitism. Finally, we could not detect an effect of ectoparasite removal on male body mass. Our results lend support to the hypothesis that ectoparasites exploit their male hosts for transmission and that male red squirrels are important for the transmission dynamics of ectoparasites in this population; however, the mechanisms (i.e., immunocompetence, testosterone) are not known. PMID:26236631

  15. Food item use by coyote sex and age classes

    SciTech Connect

    Cypher, B.L.; Spencer, K.A.; Scrivner, J.H.

    1995-10-01

    Food item use by coyotes was compared between sexes and among age classes at the Naval Petroleum Reserves, California. Item use did not differ significantly between males and females. Although leporid was the item most frequently used by all age classes, item use differed significantly between pups (< 1 year), yearlings (1 year), and adults (> 1 year), probably due to differential use of secondary items. Variation in item use among age classes could potentially bias results of coyote food habit studies.

  16. Identification of Sex-Specific Markers Reveals Male Heterogametic Sex Determination in Pseudobagrus ussuriensis.

    PubMed

    Pan, Zheng-Jun; Li, Xi-Yin; Zhou, Feng-Jian; Qiang, Xiao-Gang; Gui, Jian-Fang

    2015-08-01

    Comprehending sex determination mechanism is a first step for developing sex control breeding biotechnologies in fish. Pseudobagrus ussuriensis, one of bagrid catfishes in Bagridae, had been observed to have about threefold size dimorphism between males and females, but its sex determination mechanism had been unknown. In this study, we firstly used the amplified fragment length polymorphism (AFLP)-based screening approach to isolate a male-specific DNA fragment and thereby identified a 10,569 bp of male-specific sequence and a 10,365 bp of female-related sequence by genome walking in the bagrid catfish, in which a substantial genetic differentiation with 96.35 % nucleotide identity was revealed between them. Subsequently, a high differentiating region of 650 bp with only 70.26 % nucleotide identity was found from the corresponding two sequences, and three primer pairs of male-specific marker, male and female-shared marker with different length products in male and female genomes, and female-related marker were designed. Significantly, when these markers were used to identify genetic sex of the bagrid catfish, only male individuals was detected to amplify the male-specific marker fragment, and female-related marker was discovered to produce dosage association in females and in males. Our current data provide significant genetic evidence that P. ussuriensis has heterogametic XY sex chromosomes in males and homogametic XX sex chromosomes in females. Therefore, sex determination mechanism of P. ussuriensis is male heterogametic XX/XY system. PMID:25981673

  17. Shadow of domestic violence and extramarital sex cohesive with spousal communication among males in Nepal

    PubMed Central

    2014-01-01

    Background Public health and human right issues are challenging in low and middle income countries. The main objectives of this paper were to determine the prevalence and factors associated with domestic violence, extramarital sex, and spousal communication among male. Methods A cross-sectional study among 2466 married males in Kathmandu, Nepal was conducted using random sampling method. Adjusted odds ratios (AORs) and 95% confidence intervals (CI) of associated factors were estimated by stepwise backward likelihood ratio method. Results Prevalence of domestic violence was 63.14% (95% CI 61.20-65.05), extramarital sex was 32.12% (95% CI 30.27-34.00), and spousal communication was 48.87% (95% CI 46.85-50.90). Nearly one in five male (18.20%) had not used condom during extramarital sex. Interestingly, male who had more than three or equal children were less likely to have perpetrated domestic violence compared with those who had less children. Older male aged 25 and above were more likely (AORs = 1.55, 95% CI 1.19-2.03) to have extramarital sex compared with male aged 24 or below. Those male who had studied secondary or higher level of education were less likely to have extramarital sex compared to those who had primary level or no education. Male who had higher income were more likely to have spousal communication compared to those who had less income. Surprisingly, those male who had extramarital sex were less likely to have spousal communication compared with those was not involved in extramarital sex. Conclusion Practice of domestic violence and extramarital sex is quite common among married male in Nepal, where spousal communication is sparse. These findings can be used to advocate for immediate attention and activities needs to be endorsed by policymakers and programmers. PMID:24924872

  18. Variably male-biased sex ratio in a marine bird with females larger than males.

    PubMed

    Torres, R; Drummond, H

    1999-01-01

    When the costs of rearing males and females differ progeny sex ratios are expected to be biased toward the less expensive sex. Blue-footed booby (Sula nebouxii) females are larger and roughly 32% heavier than males, thus presumably more costly to rear. We recorded hatching and fledging sex ratios in 1989, and fledging sex ratios during the next 5 years. In 1989, the sample of 751 chicks showed male bias at hatching (56%) and at fledging (57% at 90 days). Fledging sex ratios during the five subsequent reproductive seasons were at unity (1 year) or male-biased, varying from 56% to 70%. Male bias was greater during years when mean sea surface temperature was warmer and food was presumably in short supply. During two warm-water years (only) fledging sex ratio varied with hatching date. Proportions of male fledglings increased with date from 0.48 to 0.73 in 1994, and from 0.33 to 0.79 in 1995. Similar results were obtained when the analysis was repeated using only broods with no nestling mortality, suggesting that the overall increase in the proportion of males over the season was the result of sex ratio adjustments at hatching. The male-biased sex ratio, and the increased male bias during poor breeding conditions supports the idea that daughters may be more costly than sons, and that their relative cost increases in poor conditions. PMID:20135156

  19. Sex mosaics in a male dimorphic ant Cardiocondyla kagutsuchi

    NASA Astrophysics Data System (ADS)

    Yoshizawa, Juri; Mimori, Kohei; Yamauchi, Katsusuke; Tsuchida, Koji

    2009-01-01

    Gynandromorphy, or the development of organisms with a combination of male and female morphological features, is common in Hymenoptera. The underlying mechanism is likely associated with the sex-determination system, and studying this phenomenon should lead to a deeper understanding of both embryonic development and sex determination. The reproductive capabilities of gynandromorphs (hereafter, sex mosaics) remain unclear. We studied gynandromorphy in the Malaysian ant Cardiocondyla kagutsuchi, which has sex mosaics of queens (gynandromorphs; mosaic of queens and winged male) and workers (ergatandromorphs; mosaic of worker and wingless ergatoid male). These sex mosaics were classified into seven morphological categories. Most individuals had more male than female body areas. Behavioral observations revealed that sex mosaics behave more in accordance with the “sex” of their brain than that of the reproductive organs (gaster). Relative DNA quantities showed that both female and male regions contained haploid and diploid nuclei, irrespective of their phenotypic appearance, indicating that external appearance did not reflect internal tissues. Nearly one third of the adults were sex mosaics and they were not infected with Wolbachia. Our results suggest that the production of sex mosaics in this species does not pose a substantial cost to colonies and that the underlying causes are therefore not strongly selected against.

  20. Male mutation rates and the cost of sex for females

    NASA Astrophysics Data System (ADS)

    Redfield, Rosemary J.

    1994-05-01

    ALTHOUGH we do not know why sex evolved, the twofold cost of meiosis for females provides a standard against which postulated benefits of sex can be evaluated1. The most reliable benefit is sex's ability to reduce the impact of deleterious mutations2,3. But deleterious mutations may themselves generate a large and previously overlooked female-specific cost of sex. DNA sequence comparisons have confirmed Haldane's suggestion that most mutations arise in the male germ line4,5; recent estimates of α, the ratio of male to female mutation rates, are ten, six and two in humans, primates and rodents, respectively6-8. Consequently, male gametes may give progeny more mutations than the associated sexual recombination eliminates. Here I describe computer simulations showing that the cost of male mutations can easily exceed the benefits of recombination, causing females to produce fitter progeny by parthenogenesis than by mating. The persistence of sexual reproduction by females thus becomes even more problematic.

  1. Age and sex graded helminth infections in a Nigerian village.

    PubMed

    Arinola, O; Fawole, O

    1995-02-01

    Prevalence of helminth parasites was carried out in both male and female villagers graded into three age groups (5-14 years, 15-25 years, 26-55 years). Children between 5 and 14 years of age had the highest prevalence of Ascaris, Schistosoma haematobium and Trichuris while the villagers between 26-55 years of age had lowest prevalence of these parasites. However, hookworms were highly common among the villagers aged between 26 and 55 years and least common among the school children aged between 5 and 14 years. Female children between the ages of 5 and 14 years and males of the same age group were highly infested with Ascaris and Trichuris. This finding in a Nigerian village suggested that helminth infestation is age and sex dependent which is therefore a factor of the frequency in host-parasite contact determined by mode of life of the parasites and the hosts. PMID:7796748

  2. [Changes in bones in the aging males].

    PubMed

    Grzegorzewska, Alicja E

    2007-08-01

    The report contains a summary of results on bone changes in aging male, presented during the 2nd CSSAM/ISAM North American Congress on the Aging Male. It was shown that age-related osteoporosis can be slowed in men by substitutive treatment with testosterone. Taking into account such therapy, one should remember about its adverse effects. PMID:18044351

  3. Group Work Practice with Transgendered Male to Female Sex Workers.

    ERIC Educational Resources Information Center

    Klein, Rebecca

    1999-01-01

    Examines group work with transgendered male-to-female adolescents who engage in sex work. Provides an overview of the role that sex work plays in the lives of some transgendered youth, using case examples, and offers guidance for those utilizing group work approaches with transgendered adolescents. Discusses homelessness and institutionalization,…

  4. A prospective analysis of juvenile male sex offenders: characteristics and recidivism rates as adults.

    PubMed

    Vandiver, Donna M

    2006-05-01

    This research assesses the recidivism rates of a sample of 300 registered male sex offenders who were juveniles at the time of their initial arrest for a sex offense. This sample is followed for 3 to 6 years after they reached adulthood; recidivism rates are assessed during their adulthood only. The typical juvenile is a 15-year-old Caucasian male who was arrested for sexual assault or indecency with a child. The majority of the victims are females with an average age of 8. Although only 13 are rearrested during the follow-up period for a sex offense, more than half of the sample is arrested at least once for a nonsexual offense. The results of a Cox regression indicate that victim age, offender age, and victim sex are significant predictors of recidivism during adulthood. PMID:16574639

  5. Hands as Sex Cues: Sensitivity Measures, Male Bias Measures, and Implications for Sex Perception Mechanisms

    PubMed Central

    Gaetano, Justin; van der Zwan, Rick; Blair, Duncan; Brooks, Anna

    2014-01-01

    Sex perceptions, or more particularly, sex discriminations and sex categorisations, are high-value social behaviours. They mediate almost all inter-personal interactions. The two experiments reported here had the aim of exploring some of the basic characteristics of the processes giving rise to sex perceptions. Experiment 1 confirmed that human hands can be used as a cue to an individual’s sex even when colour and texture cues are removed and presentations are brief. Experiment 1 also showed that when hands are sexually ambiguous observers tend to classify them as male more often than female. Experiment 2 showed that “male bias” arises not from sensitivity differences but from differences in response biases. Observers are conservative in their judgements of targets as female but liberal in their judgements of targets as male. These data, combined with earlier reports, suggest the existence of a sex-perception space that is cue-invariant. PMID:24603615

  6. Hands as sex cues: sensitivity measures, male bias measures, and implications for sex perception mechanisms.

    PubMed

    Gaetano, Justin; van der Zwan, Rick; Blair, Duncan; Brooks, Anna

    2014-01-01

    Sex perceptions, or more particularly, sex discriminations and sex categorisations, are high-value social behaviours. They mediate almost all inter-personal interactions. The two experiments reported here had the aim of exploring some of the basic characteristics of the processes giving rise to sex perceptions. Experiment 1 confirmed that human hands can be used as a cue to an individual's sex even when colour and texture cues are removed and presentations are brief. Experiment 1 also showed that when hands are sexually ambiguous observers tend to classify them as male more often than female. Experiment 2 showed that "male bias" arises not from sensitivity differences but from differences in response biases. Observers are conservative in their judgements of targets as female but liberal in their judgements of targets as male. These data, combined with earlier reports, suggest the existence of a sex-perception space that is cue-invariant. PMID:24603615

  7. Behavioral and psychosocial correlates of anal sex among male clients of female sex workers in Tijuana, Mexico.

    PubMed

    Semple, Shirley J; Strathdee, Steffanie A; Pitpitan, Eileen V; Chavarin, Claudia; Patterson, Thomas L

    2015-05-01

    Most studies of heterosexual sex risk practices have focused on condomless vaginal sex despite evidence that condomless anal sex has a significantly higher risk of HIV transmission. The present study focused on male clients' anal sex practices with female sex workers (FSWs) in Tijuana, Mexico, where an HIV epidemic is growing among high-risk groups. Logistic regression analyses were used to identify psychosocial and behavioral correlates of anal sex among male clients. Our sample of HIV-negative men (N = 400) was predominantly Latino (87.5 %), born in Mexico (78.8 %), never married (36.8 %) or in a regular or common-law marriage (31.5 %), and employed (62.8 %), with an average age and education of 37.8 and 9.2 years, respectively. Eighty-nine percent identified as heterosexual and 11 % as bisexual. By design, 50 % of the sample resided in Tijuana and the other 50 % in San Diego County. Nearly half (49 %) reported at least one incident of anal sex with a FSW in Tijuana in the past 4 months; of those participants, 85 % reported that one or more of their anal sex acts with FSWs had been without a condom. In a multivariate model, anal sex with a FSW in the past 4 months was associated with bisexual identification, methamphetamine use with FSWs, repeat visits to the same FSW, higher scores on perceived stigma about being a client of FSWs, and sexual compulsivity. Prevention programs are needed that address the behavioral and psychosocial correlates of heterosexual anal sex in order to reduce HIV/STI transmission risk among male clients, FSWs, and their sexual network members. PMID:25795530

  8. [Sex Specificity in Age-Related Thyroid Hormone Responsiveness].

    PubMed

    Suzuki, Satoru

    2016-01-01

    Similar to other systems, the endocrine system is affected by aging. Thyroid hormone, the action of which is affected by many factors, has been shown to be associated with longevity. The most useful marker for assessment of the thyroid hormone action is the TSH level. Although age and sex are believed to modify the pituitary set point or response to the free thyroid hormone concentration, the precise age- and sex-dependent responses to thyroid hormone have yet to be reported. In this lecture, molecular aspects of resistance to thyroid hormone are initially overviewed. After presentation of the evidence that the TSH-thyroid hormone axis is evolutionarily modified, and that negative feedback mechanisms may start to play roles in homeostatic regulation at the time of delivery, the rationale of age-dependent thyroid hormone resistance is introduced. To assess the age- and sex-dependent resistance to thyroid hormone, the index is provided by the formula based on the relationship between thyroid hormone and TSH levels. The index is calculated by the results of thyroid function tests obtained from the two individual clinical groups. From the results, there were negative relationships between the free T3 resistance index and age in males of both groups, while there were no apparent relationships in females. These findings indicate that there is a male-specific response to thyroid hormone with aging. Furthermore, the specific features of the response may not be affected by environmental factors such as the presence of disorders or medical treatments. PMID:27192800

  9. Age and sex selectivity in trapping mule deer

    SciTech Connect

    Garrott, R.A.; White, G.C.

    1982-01-01

    A mule deer (Odocoileus hemionus) trapping experiment is described using modified Clover traps in which changes in the placement of bait and height of the trap door modified the ratio of adult does to male and female fawns captured. The mechanisms responsible for the changes in age-sex capture ratios are discussed and indicate that modified Clover traps selectivity capture mule deer, thus introducing bias into population sampling. (JMT)

  10. Combined Effect of Fetal Sex and Advanced Maternal Age on Pregnancy Outcomes

    PubMed Central

    Weissmann-Brenner, Alina; Simchen, Michal J.; Zilberberg, Eran; Kalter, Anat; Dulitzky, Mordechai

    2015-01-01

    Background Fetal sex and maternal age are each known to affect outcomes of pregnancies. The objective of the present study was to investigate the influence of the combination of maternal age and fetal sex on pregnancy outcomes in term and post-term singleton pregnancies. Material/Methods This was a retrospective study on term singleton pregnancies delivered between 2004 and 2008 at the Chaim Sheba Medical Center. Data collected included maternal age, fetal sex, and maternal and neonatal complications. The combined effect of fetal sex and maternal age on complications of pregnancy was assessed by multivariable logistic regression models. Results The study population comprised 37,327 pregnancies. The risk of operative deliveries increased with maternal age ≥40 and in pregnancies with male fetuses. The risk of maternal diabetes and of longer hospitalization increased as maternal age increased, and in women <40 carrying male fetuses. The risk of hypertensive disorders increased in pregnancies with males as maternal age advanced. The risk of shoulder dystocia and neonatal respiratory complications increased in male neonates born to women<40. The risk of neonatal hypoglycemia increased in males for all maternal ages. Conclusions Risk assessment for fetal sex and advanced maternal age were given for different pregnancy complications. Knowledge of fetal sex adds value to the risk assessment of pregnancies as maternal age increases. PMID:25892459

  11. [Male impotence in old age].

    PubMed

    Pentimone, F; Del Corso, L

    1994-05-01

    Normal aging does not induce impotence, but only modifies the physiology of the erection which, however, allows good sexual intercourse. Impotence, found in 55.0% of the over 75 men, is due to organic or psychogenic causes: above all, penile arterial insufficiency and the collateral effects of drugs for the diseases which often affect the elderly, are the main factors. PMID:8028756

  12. The Sicker Sex: Understanding Male Biases in Parasitic Infection, Resource Allocation and Fitness

    PubMed Central

    Córdoba-Aguilar, Alex; Munguía-Steyer, Roberto

    2013-01-01

    The “sicker sex” idea summarizes our knowledge of sex biases in parasite burden and immune ability whereby males fare worse than females. The theoretical basis of this is that because males invest more on mating effort than females, the former pay the costs by having a weaker immune system and thus being more susceptible to parasites. Females, conversely, have a greater parental investment. Here we tested the following: a) whether both sexes differ in their ability to defend against parasites using a natural host-parasite system; b) the differences in resource allocation conflict between mating effort and parental investment traits between sexes; and, c) effect of parasitism on survival for both sexes. We used a number of insect damselfly species as study subjects. For (a), we quantified gregarine and mite parasites, and experimentally manipulated gregarine levels in both sexes during adult ontogeny. For (b), first, we manipulated food during adult ontogeny and recorded thoracic fat gain (a proxy of mating effort) and abdominal weight (a proxy of parental investment) in both sexes. Secondly for (b), we manipulated food and gregarine levels in both sexes when adults were about to become sexually mature, and recorded gregarine number. For (c), we infected male and female adults of different ages and measured their survival. Males consistently showed more parasites than females apparently due to an increased resource allocation to fat production in males. Conversely, females invested more on abdominal weight. These differences were independent of how much food/infecting parasites were provided. The cost of this was that males had more parasites and reduced survival than females. Our results provide a resource allocation mechanism for understanding sexual differences in parasite defense as well as survival consequences for each sex. PMID:24194830

  13. Observations on sex ratio and behavior of males in Xyleborinus saxesenii Ratzeburg (Scolytinae, Coleoptera)

    PubMed Central

    H.W. Biedermann, Peter

    2010-01-01

    Abstract Strongly female-biased sex ratios are typical for the fungalfeeding haplodiploid Xyleborini (Scolytinae, Coleoptera), and are a result of inbreeding and local mate competition (LMC). These ambrosia beetles are hardly ever found outside of trees, and thus male frequency and behavior have not been addressed in any empirical studies to date. In fact, for most species the males remain undescribed. Data on sex ratios and male behavior could, however, provide important insights into the Xyleborini’s mating system and the evolution of inbreeding and LMC in general. In this study, I used in vitro rearing methods to obtain the first observational data on sex ratio, male production, male and female dispersal, and mating behavior in a xyleborine ambrosia beetle. Females of Xyleborinus saxesenii Ratzeburg produced between 0 and 3 sons per brood, and the absence of males was relatively independent of the number of daughters to be fertilized and the maternal brood sex ratio. Both conformed to a strict LMC strategy with a relatively precise and constant number of males. If males were present they eclosed just before the first females dispersed, and stayed in the gallery until all female offspring had matured. They constantly wandered through the gallery system, presumably in search of unfertilized females, and attempted to mate with larvae, other males, and females of all ages. Copulations, however, only occurred with immature females. From galleries with males, nearly all females dispersed fertilized. Only a few left the natal gallery without being fertilized, and subsequently went on to produce large and solely male broods. If broods were male-less, dispersing females always failed to found new galleries. PMID:21594184

  14. Converging Evidence of Ubiquitous Male Bias in Human Sex Perception.

    PubMed

    Gaetano, Justin; van der Zwan, Rick; Oxner, Matthew; Hayward, William G; Doring, Natalie; Blair, Duncan; Brooks, Anna

    2016-01-01

    Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males-an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers' race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli--while still tending to accept stimuli as male--were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception. PMID:26859570

  15. Employment Discrimination: Age, Sex and National Origin.

    ERIC Educational Resources Information Center

    Carter, David G.; Lawson, Miriam

    Chapter 17 of a book on school law is an historical review of judicial decisions and legislative enactments that apply to employment. The purpose of the chapter is to analyze those cases concerned with discrimination because of sex, age, or national origin, and to discuss the decisions of the U.S. Supreme Court in these areas. Not until the…

  16. Teeth, Sex, and Testosterone: Aging in the World's Smallest Primate

    PubMed Central

    Zohdy, Sarah; Gerber, Brian D.; Tecot, Stacey; Blanco, Marina B.; Winchester, Julia M.; Wright, Patricia C.; Jernvall, Jukka

    2014-01-01

    Mouse lemurs (Microcebus spp.) are an exciting new primate model for understanding human aging and disease. In captivity, Microcebus murinus develops human-like ailments of old age after five years (e.g., neurodegeneration analogous to Alzheimer's disease) but can live beyond 12 years. It is believed that wild Microcebus follow a similar pattern of senescence observed in captive animals, but that predation limits their lifespan to four years, thus preventing observance of these diseases in the wild. Testing whether this assumption is true is informative about both Microcebus natural history and environmental influences on senescence, leading to interpretation of findings for models of human aging. Additionally, the study of Microcebus longevity provides an opportunity to better understand mechanisms of sex-biased longevity. Longevity is often shorter in males of species with high male-male competition, such as Microcebus, but mouse lemurs are sexually monomorphic, suggesting similar lifespans. We collected individual-based observations of wild brown mouse lemurs (Microcebus rufus) from 2003–2010 to investigate sex-differences in survival and longevity. Fecal testosterone was measured as a potential mechanism of sex-based differences in survival. We used a combination of high-resolution tooth wear techniques, mark-recapture, and hormone enzyme immunoassays. We found no dental or physical signs of senescence in M. rufus as old as eight years (N = 189, ages 1–8, mean = 2.59±1.63 SE), three years older than captive, senescent congeners (M. murinus). Unlike other polygynandrous vertebrates, we found no sex difference in age-dependent survival, nor sex or age differences in testosterone levels. While elevated male testosterone levels have been implicated in shorter lifespans in several species, this is one of the first studies to show equivalent testosterone levels accompanying equivalent lifespans. Future research on captive aged individuals can determine

  17. Myth Information and Bizarre Beliefs of Male Juvenile Sex Offenders.

    ERIC Educational Resources Information Center

    Lakey, Joyce F.

    1992-01-01

    Describes mythical beliefs, thinking errors, and faulty attitudes collected from a group of 67 male juvenile sex offenders. Addresses four major thinking errors: pretentiousness, uniqueness, failure to assume responsibility, and distorted values. Notes that therapists need this information to develop effective treatment strategies for replacing…

  18. Black Male Masculinity and Same-Sex Friendships.

    ERIC Educational Resources Information Center

    Harris, Shanette M.

    1992-01-01

    Examines how African-American alternative masculine behaviors are expressed within same-sex peer groups and friendships. It is proposed that African-American males have adopted an alternative style of masculinity to cope with social and interpersonal pressures, even though it can sometimes be dysfunctional and associated with negative…

  19. The Male Sex Role: A Selected and Annotated Bibliography.

    ERIC Educational Resources Information Center

    Grady, Kathleen E.; And Others

    This bibliography, containing more than 250 entries, presents research and theoretical perspectives into the male sex role. Articles were chosen for their usefulness to researchers, with emphasis on scientific and data-based research literature. All the annotations use a standard format including subjects, method, findings and comments. Articles…

  20. Mallard age and sex determination from wings

    USGS Publications Warehouse

    Carney, S.M.; Geis, A.D.

    1960-01-01

    This paper describes characters on the wing plumage of the mallard that indicate age and sex. A key outlines a logical order in which to check age and sex characters on wings. This method was tested and found to be more than 95 percent reliable, although it was found that considerable practice and training with known-age specimens was required to achieve this level of accuracy....The implications of this technique and the sampling procedure it permits are discussed. Wing collections could provide information on production, and, if coupled with a banding program could permit seasonal population estimates to be calculated. In addition, representative samples of wings would provide data to check the reliability of several other waterfowl surveys.

  1. Serotonin modulation of cerebral glucose metabolism: sex and age effects.

    PubMed

    Munro, Cynthia A; Workman, Clifford I; Kramer, Elisse; Hermann, Carol; Ma, Yilong; Dhawan, Vijay; Chaly, Thomas; Eidelberg, David; Smith, Gwenn S

    2012-11-01

    The serotonin system is implicated in a variety of psychiatric disorders whose clinical presentation and response to treatment differ between males and females, as well as with aging. However, human neurobiological studies are limited. Sex differences in the cerebral metabolic response to an increase in serotonin concentrations were measured, as well as the effect of aging, in men compared to women. Thirty-three normal healthy individuals (14 men/19 women, age range 20-79 years) underwent two resting positron emission tomography studies with the radiotracer [18F]-2-deoxy-2-fluoro-D-glucose ([(18)F]-FDG) after placebo and selective serotonin reuptake inhibitor (SSRI, citalopram) infusions on two separate days. Results indicated that women demonstrated widespread areas of increased cortical glucose metabolism with fewer areas of decrease in metabolism in response to citalopram. Men, in contrast, demonstrated several regions of decreased cortical metabolism, but no regions of increased metabolism. Age was associated with greater increases in women and greater decreases in men in most brain regions. These results support prior studies indicating that serotonin function differs in men and women across the lifespan. Future studies aimed at characterizing the influences of age and sex on the serotonin system in patients with psychiatric disorders are needed to elucidate the relationship between sex and age differences in brain chemistry and associated differences in symptom presentation and treatment response. PMID:22836227

  2. Males on demand: the environmental-neuro-endocrine control of male sex determination in daphnids.

    PubMed

    LeBlanc, Gerald A; Medlock, Elizabeth K

    2015-11-01

    Branchiopod crustaceans (e.g., Daphnia sp.) and some other taxa utilize both asexual and sexual reproduction to maximize population sustainability. The decision to switch from asexual to sexual reproduction is triggered by environmental cues that foretell a potentially detrimental change in environmental conditions. This review describes the cascade of events beginning with environmental cues and ending with changes in gene expression that dictate male sex determination in daphnids, the initial event in the switch to sexual reproduction. Several environmental cues have been identified which, either in isolation or in combination, stimulate male sex determination. These cues are typically associated with change of season, exhaustion of resources or loss of habitat. Maternal daphnids receive and respond to these cues, we propose, through the secretion of neuropeptides, which suppress (hyperglycemic hormone-like neuropeptides, allatostatin) or stimulate (allatotropin) the male sex differentiation program. In response, maternal daphnids produce the male sex-determining hormone, methyl farnesoate. Methyl farnesoate binds to a protein MET that dimerizes with the protein SRC forming an active transcription factor. This complex then regulates the expression of genes, primarily doublesex (dsx), involved in programming the single-celled embryo to develop into a male. In the absence of methyl farnesoate programming, the embryo develops into a female. Epigenetic modifications of the genome as a possible mode of methyl farnesoate action and the utility of this model to decipher the role of epigenetics in sex differentiation in other species are discussed. PMID:26237283

  3. Masculinity and relationship agreements among male same-sex couples.

    PubMed

    Wheldon, Christopher W; Pathak, Elizabeth B

    2010-09-01

    Extradyadic sex is a significant source of risk for sexually transmitted infections (STIs) among men in same-sex relationships. Nonmonogamous sexual agreements are common among male same-sex couples and may serve as effective targets for risk reduction interventions; however, there is a dearth of research reporting on the social and cultural determinants of explicit nonmonogamous agreements. In this study, it was hypothesized that attitudes toward dominant cultural standards of masculinity (i.e., normative masculinity) would be associated with the types of sexual agreements negotiated among gay male couples. An Internet-based survey was used to collect data from 931 men for this analysis. Results indicated that men who reported high endorsement of normative masculinity were more likely to be in nonmonogamous relationships. Furthermore, high endorsement of normative masculinity was predictive of relationship agreements characterized as the most sexually permissive. These findings indicate that rather than simply predicting nonmonogamy in gay male couples, attitudes toward masculinity may be indirectly related to increased risk of STIs by influencing the types of sexual agreements negotiated. This is the first empirical study to emphasize the role of masculinity as an explanatory factor of same-sex relationship agreements. PMID:19626535

  4. Converging Evidence of Ubiquitous Male Bias in Human Sex Perception

    PubMed Central

    Gaetano, Justin; van der Zwan, Rick; Oxner, Matthew; Hayward, William G.; Doring, Natalie; Blair, Duncan; Brooks, Anna

    2016-01-01

    Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males–an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers’ race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli–while still tending to accept stimuli as male–were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception. PMID:26859570

  5. Spatial distribution of intracortical porosity varies across age and sex

    PubMed Central

    Nirody, Jasmine A.; Cheng, Karen P.; Parrish, Robin M.; Burghardt, Andrew J.; Majumdar, Sharmila; Link, Thomas M.; Kazakia, Galateia J.

    2015-01-01

    Cortical bone porosity is a major determinant of strength, stiffness, and fracture toughness of cortical tissue. The goal of this work was to investigate changes in spatial distribution and microstructure of cortical porosity associated with aging in men and women. The specific aims were to: 1) develop an automated technique for spatial analysis of cortical microstructure based on HR-pQCT data, and; 2) apply this technique to explore sex- and age-specific spatial distribution and microstructure of porosity within the cortex. We evaluated HR-pQCT images of the distal tibia from a cross-sectional cohort of 145 individuals, characterizing detectable pores as being in the endosteal, midcortical, or periosteal layers of the cortex. Metrics describing porosity, pore number, and pore size were quantifiedwithin each layer and compared across sexes, age groups, and cortical layers. The elderly cohort (65–78 years, n=22) displayed higher values than the young cohort (20–29 years, n=29) for all parameters both globally and within each layer. While all three layers displayed significant age-related porosity increases, the greatest difference in porosity between the young and elderly cohort was in the midcortical layer (+344%, p < 0.001). Similarly, the midcortical layer reflected the greatest differences between young and elderly cohorts in both pore number (+243%, p < 0.001) and size (+28%, p < 0.001). Females displayed greater age-related changes in porosity and pore number than males. Females and males displayed comparable small to non-significant changes with age in pore size. In summary, considerable variability exists in the spatial distribution of detectable cortical porosity at the distal tibia, and this variability is dependent on age and sex. Intracortical pore distribution analysis may ultimately provide insight into both mechanisms of pore network expansion and biomechanical consequences of pore distribution. PMID:25701139

  6. The use of the Internet by gay and bisexual male escorts: sex workers as sex educators.

    PubMed

    Parsons, J T; Koken, J A; Bimbi, D S

    2004-11-01

    While prior studies have targeted street-based male sex workers as potential vectors of disease transmission, the number of men who work independently through Internet chat-rooms and other online endeavors has steadily increased. It is likely that these men differ substantially from their street-based counterparts in terms of sexual risk behaviors with their clients. The purpose of this study was to explore the ways in which the Internet has impacted the work of male escorts and their sexual practices with clients. Semi-structured qualitative interviews and quantitative surveys were administered to 46 such men. Less than half the men reported unprotected anal sex with clients. The qualitative data lend support to this finding, in that the majority talked about refusing any unsafe sex with clients, and many reported taking the extra step of educating their clients about the dangers of risky sex. Some of the escorts described the methods used to incorporate safer sex practices into sessions with their clients. Internet-based male escorts can play an important role as potential sex educators on the front lines of the fight against HIV and other sexually transmitted infections. PMID:15511734

  7. Transgenerational sex determination: the embryonic environment experienced by a male affects offspring sex ratio

    PubMed Central

    Warner, Daniel A.; Uller, Tobias; Shine, Richard

    2013-01-01

    Conditions experienced during embryonic development can have lasting effects, even carrying across generations. Most evidence for transgenerational effects comes from studies of female mammals, with much less known about egg-laying organisms or paternally-mediated effects. Here we show that offspring sex can be affected by the incubation temperature its father experiences years earlier. We incubated eggs of an Australian lizard with temperature-dependent sex determination under three thermal regimes; some eggs were given an aromatase inhibitor to produce sons at temperatures that usually produce only daughters. Offspring were raised to maturity and freely interbred within field enclosures. After incubating eggs of the subsequent generation and assigning parentage, we found that the developmental temperature experienced by a male significantly influences the sex of his future progeny. This transgenerational effect on sex ratio may reflect an epigenetic influence on paternally-inherited DNA. Clearly, sex determination in reptiles is far more complex than is currently envisaged. PMID:24048344

  8. Greater memory impairment in dementing females than males relative to sex-matched healthy controls.

    PubMed

    Gale, Shawn D; Baxter, Leslie; Thompson, Juliann

    2016-01-01

    Previously we demonstrated sex differences in episodic memory in healthy elderly and suggested that normative data be separated by sex. The present study extended the exploration of sex differences on memory measures into two clinical populations, mild cognitive impairment (MCI) and Alzheimer's disease (AD). Seventy-six subjects with MCI and 101 subjects with AD diagnosed by a multidisciplinary team were included. These two groups were also compared to a group of 177 healthy elderly control participants. Sex differences on the Rey Auditory Verbal Learning Test (RAVLT; total and delayed recall) raw scores and Brief Visuospatial Memory Test-Revised (BVMT-R) were demonstrated within the healthy but not the MCI or AD groups. Calculating z scores by sex for both dementing groups based on the healthy controls suggested a larger performance gap between healthy and dementing women than between healthy and dementing men. MCI females were on average 0.48 standard deviations lower for total verbal learning compared to healthy female controls than were MCI males when compared to healthy male controls. For verbal delayed recall the gap was even larger (SD = 1.09). Similarly, on the BVMT-R, a measure of visual memory, the difference was 0.60 standard deviations for total visual learning and 0.99 standard deviations for delayed recall. This same sex difference, with females showing greater impairment compared to the controls group than did the males, was also present within the AD group. The greater memory impairment in dementing females rather than males when compared to sex-matched healthy controls was unlikely to be due to more severe illness since females performed equivalently to males on the Clinical Dementia Rating Scale, Mini-Mental Status Examination, and Dementia Rating Scale, and were also similar for age, education, and apolipoprotein status. The present study suggested relatively greater memory impairment in females with MCI or AD than in controls. PMID:26735615

  9. Assisted reproduction in a cohort of same-sex male couples and single men.

    PubMed

    Grover, Stephanie A; Shmorgun, Ziva; Moskovtsev, Sergey I; Baratz, Ari; Librach, Clifford L

    2013-08-01

    To date, there is limited published data on same-sex male couples and single men using assisted reproduction treatment to build their families. The objective of this retrospective study was to better understand treatment considerations and outcomes for this population when using assisted reproduction treatment. A total of 37 same-sex male couples and eight single men (seven homosexual and one heterosexual) who attended the CReATe Fertility Centre for assisted reproduction services were studied. There was a 21-fold increase in the number of same-sex male couples and single men undergoing assisted reproduction treatment since 2003. The mean age was 46years (24-58). Twenty-eight couples (76%) chose to use spermatozoa from both partners to fertilize their donated oocytes. Most men (32 same-sex male couples and seven single men; 87%) obtained oocytes from an anonymous donor, whereas five couples and one single man (13%) had a known donor. Anonymous donors who were open to be contacted by the child after the age of 18 were selected by 67% of patients. Of all 25 deliveries, eight (32%) were sets of twins. All of the twins were half genetic siblings. PMID:23768615

  10. Sex-role orientation and work adaptation of male nurses.

    PubMed

    Krausz, M; Kedem, P; Tal, Z; Amir, Y

    1992-10-01

    Three competing hypotheses regarding the influence of sex-role orientation on work-stress (pressure and strain at work) and work-attraction (work centrality and satisfaction) adaptation of 154 male nurses were contrasted. The findings reveal that even in a female-dominated profession, masculine-type male nurses were, on the whole, the best adapted type while the feminine-type male nurses were the least. The androgynous-type nurses, though ranking high in pressure and strain stemming from their work, nevertheless ranked highest in work satisfaction. In contrast, the undifferentiated were not stressed nor pressured at work, but they did not enjoy their work. These analyses were repeated for 54 female nurses. Among the female nurses no significant differences were found between the four sex role orientations, indicating that the differences found among the male nurses stemmed from the special situation in which a male nurse finds himself. It is suggested that change in the nature of the nursing profession into more "masculine" tasks also may partially explain the results. PMID:1529123

  11. Sex ratio bias, male aggression, and population collapse in lizards.

    PubMed

    Le Galliard, Jean-François; Fitze, Patrick S; Ferrière, Régis; Clobert, Jean

    2005-12-13

    The adult sex ratio (ASR) is a key parameter of the demography of human and other animal populations, yet the causes of variation in ASR, how individuals respond to this variation, and how their response feeds back into population dynamics remain poorly understood. A prevalent hypothesis is that ASR is regulated by intrasexual competition, which would cause more mortality or emigration in the sex of increasing frequency. Our experimental manipulation of populations of the common lizard (Lacerta vivipara) shows the opposite effect. Male mortality and emigration are not higher under male-biased ASR. Rather, an excess of adult males begets aggression toward adult females, whose survival and fecundity drop, along with their emigration rate. The ensuing prediction that adult male skew should be amplified and total population size should decline is supported by long-term data. Numerical projections show that this amplifying effect causes a major risk of population extinction. In general, such an "evolutionary trap" toward extinction threatens populations in which there is a substantial mating cost for females, and environmental changes or management practices skew the ASR toward males. PMID:16322105

  12. Multiple risks among male and transgender sex workers in Pakistan.

    PubMed

    Collumbien, Martine; Chow, Jaime; Qureshi, Ayaz Ahmed; Rabbani, Aliya; Hawkes, Sarah

    2008-01-01

    Using data from a qualitative study and a subsequent quantitative survey among 918 male and transgender sex workers (MTSW), we explore the context of multiple risks they face. We show that over one-fifth of MTSW have sex with IDU clients. Combined with high levels of risk behavior and very low levels of risk reduction and knowledge, the extent of sexual networking with men who inject drugs contributes further to the sex workers' health risks. Our findings suggest that isolated interventions with single-risk groups are unlikely to be sufficient to control the spread of the epidemic in Pakistan. We highlight the need for integrated approaches to risk reduction programs among MTSW and IDUs. PMID:19856740

  13. Purpose-in-Life Test: Age and Sex Differences

    ERIC Educational Resources Information Center

    Meier, Augustine; Edwards, Henry

    1974-01-01

    This study examined age and sex differences, and the interaction of age x sex, with respect to "meaning in life" as defined by Frankl and measured by the Purpose-in-Life Test (PIL) developed by Crumbaugh and Maholick. (Author)

  14. Risk factors for HIV and syphilis infection among male sex workers who have sex with men: a cross-sectional study in Hangzhou, China, 2011

    PubMed Central

    Luo, Yan; Zhu, Chunyan; Chen, Shuchang; Geng, Qingshan; Fu, Rong; Li, Xiting; Xu, Ke; Cheng, Jie; Ding, Jianming

    2015-01-01

    Objective To investigate the prevalence and risk factors of HIV and syphilis infection among men who have sex with men (MSM) in male sex workers (MSW). Design Cross-sectional survey. Setting Hangzhou, China. Participants 259 MSW in MSM were recruited by respondent-driven sampling from May 2011 to December 2011.The inclusion criteria were: (1) age ≥18 years; (2) engaging in sex with men in the previous year and (3) willing to cooperate in the implementation of the study. Outcome measures HIV-related knowledge, high-risk behaviour and condom use. Results Among these MSW in MSM, 23.2% were infected with HIV and/or syphilis, 8.9% were infected only with HIV, 12.7% only with syphilis and 1.5% with HIV/syphilis co-infection; 96.6% sold sex to males, 8.9% bought sex from males and 15.4% sold sex to females; 49.0% had non-commercial sex behaviours with males and 24.3% with females. The rate of condom use while having commercial sex with clients was 86.9% and 53.3% (selling anal and oral sex to males, respectively), 95.5% (buying sex from males) and 77.5% (selling sex to females), respectively. Regarding their non-commercial sex behaviour, the rate of condom use was 77.2% (with males) and 49.2% (with females), respectively. Multivariate analysis showed that age >30 years (OR 1.055; 95% CIs 1.015 to 1.095) and having ≥10 non-commercial male sex partners (OR, 1.573; 95% CI 1.018 to 2.452) were significantly associated with HIV/syphilis infection, while heterosexuality (OR, 0.238; 95% CI 0.066 to 0.855) was significantly associated with a low HIV/syphilis infection rate. Conclusions The MSW in MSM population in Hangzhou has a high prevalence of HIV/syphilis infection, poor perceived risks of HIV and more engagement in unsafe sex with its clients and partners, in addition to a low rate of condom use. These risk factors may account for their relatively high infection rate of HIV/syphilis. PMID:25922096

  15. Relative age effect in Japanese male athletes.

    PubMed

    Nakata, Hiroki; Sakamoto, Kiwako

    2011-10-01

    The present study investigated the relative age effect, a biased distribution of elite athletes' birthdates, in Japanese male athletes. Japan applies a unique annual-age grouping for sport and education, which is from April 1 to March 31 of the following year. A total of 4,318 male athletes was evaluated from 12 sports: baseball, soccer, basketball, volleyball, handball, golf, horse racing, rugby, American football, sumo, Ekiden (track and field in long distance), and badminton. They played in the top level of Japanese leagues for each sport in 2010. The distribution of the birth dates was examined in each sport and showed significant relative age effect in baseball, soccer, volleyball, Ekiden, basketball, sumo, and horse racing, but not in all sports. The findings suggest that although the school year in Japan starts on April 1, significant relative age effects are observed in some sporting events. PMID:22185072

  16. Age, sex and reproductive status affect boldness in dogs.

    PubMed

    Starling, Melissa J; Branson, Nicholas; Thomson, Peter C; McGreevy, Paul D

    2013-09-01

    Boldness in dogs is believed to be one end of the shy-bold axis, representing a super-trait. Several personality traits fall under the influence of this super-trait. Previous studies have found that boldness is affected by breed and breed groups, influences performance in sporting dogs, and is affected in some cases by the sex of the dogs. This study investigated the effects of dog age, sex and reproductive status on boldness in dogs by way of a dog personality survey circulated amongst Australian dog owners. Age had a significant effect on boldness (F=4.476; DF=16,758; P<0.001), with boldness decreasing with age in years. Males were bolder than females (F=19.219; DF=1,758; P<0.001) and entire dogs were bolder than neutered dogs (F=4.330; DF=1,758; P<0.038). The study indicates how behaviour may change in adult dogs as they age and adds to the literature on how sex and reproductive status may affect personality in dogs. PMID:23778256

  17. Age, APOE and sex: Triad of risk of Alzheimer's disease.

    PubMed

    Riedel, Brandalyn C; Thompson, Paul M; Brinton, Roberta Diaz

    2016-06-01

    Age, apolipoprotein E ε4 (APOE) and chromosomal sex are well-established risk factors for late-onset Alzheimer's disease (LOAD; AD). Over 60% of persons with AD harbor at least one APOE-ε4 allele. The sex-based prevalence of AD is well documented with over 60% of persons with AD being female. Evidence indicates that the APOE-ε4 risk for AD is greater in women than men, which is particularly evident in heterozygous women carrying one APOE-ε4 allele. Paradoxically, men homozygous for APOE-ε4 are reported to be at greater risk for mild cognitive impairment and AD. Herein, we discuss the complex interplay between the three greatest risk factors for Alzheimer's disease, age, APOE-ε4 genotype and chromosomal sex. We propose that the convergence of these three risk factors, and specifically the bioenergetic aging perimenopause to menopause transition unique to the female, creates a risk profile for AD unique to the female. Further, we discuss the specific risk of the APOE-ε4 positive male which appears to emerge early in the aging process. Evidence for impact of the triad of AD risk factors is most evident in the temporal trajectory of AD progression and burden of pathology in relation to APOE genotype, age and sex. Collectively, the data indicate complex interactions between age, APOE genotype and gender that belies a one size fits all approach and argues for a precision medicine approach that integrates across the three main risk factors for Alzheimer's disease. PMID:26969397

  18. The scent of inbreeding: a male sex pheromone betrays inbred males

    PubMed Central

    van Bergen, Erik; Brakefield, Paul M.; Heuskin, Stéphanie; Zwaan, Bas J.; Nieberding, Caroline M.

    2013-01-01

    Inbreeding depression results from mating among genetically related individuals and impairs reproductive success. The decrease in male mating success is usually attributed to an impact on multiple fitness-related traits that reduce the general condition of inbred males. Here, we find that the production of the male sex pheromone is reduced significantly by inbreeding in the butterfly Bicyclus anynana. Other traits indicative of the general condition, including flight performance, are also negatively affected in male butterflies by inbreeding. Yet, we unambiguously show that only the production of male pheromones affects mating success. Thus, this pheromone signal informs females about the inbreeding status of their mating partners. We also identify the specific chemical component (hexadecanal) probably responsible for the decrease in male mating success. Our results advocate giving increased attention to olfactory communication as a major causal factor of mate-choice decisions and sexual selection. PMID:23466986

  19. Sex difference and postnatal change of maternal behavioral patterns in juvenile male and female rats.

    PubMed

    Shima, Satoshi; Urano, Aya; Korányi, Lajos; Yamanouchi, Korehito

    2005-06-01

    Juvenile rats are known to show certain elements of maternal behavior. In this experiment, to investigate sex difference and postnatal change of retrieving and pup-cleaning (licking) behaviors in juvenile rats, these behaviors were recorded using new observation method at 20, 30 and 45 days of age in female and male Wistar rats. At 20 days of age, maternal behavior was observed in a common plastic observation cage (test A) and then test B was performed. In the test B, observation was carried out using a cage with a wooden box that was open on one side, helping the juveniles to establish a nest. As the results of day 20, most rats in all groups showed licking behavior in both the test A and B. The incidence of retrieving behavior increased from the test A to the test B with the box in both sexes, especially in males (p<0.01). The box is thought to play a facilitative role in induction of retrieving. Moreover, the incidence in males was higher than that in females in the test B (p<0.001). At 30 and 45 days of age, only a test B with box was performed. The incidences of licking and retrieving behaviors at 30 days of age were decreased significantly compared to those at 20 days of age in both sexes(p<0.001). Further decrease from 30 days to 45 days was observed. These results suggest that in juvenile rat, incidence of retrieving behavior in males is higher than that in females but there is no sex difference in incidence of licking behavior. Potency to show these behaviors decreases acutely before puberty in rats. PMID:15988166

  20. Large-Scale Age-Dependent Skewed Sex Ratio in a Sexually Dimorphic Avian Scavenger

    PubMed Central

    Lambertucci, Sergio A.; Carrete, Martina; Donázar, José Antonio; Hiraldo, Fernando

    2012-01-01

    Age-dependent skewed sex ratios have been observed in bird populations, with adult males generally outnumbering females. This trend is mainly driven by higher female mortality, sometimes associated with anthropogenic factors. Despite the large amount of work on bird sex ratios, research examining the spatial stability of adult sex ratios is extremely scarce. The Andean condor (Vultur gryphus) is the only bird of prey with strong sexual dimorphism favouring males (males are 30% heavier than females). By examining data from most of its South-American range, we show that while the juvenile sex ratio is balanced, or even female-skewed, the sex ratio becomes increasing male-skewed with age, with adult males outnumbering females by >20%, and, in some cases by four times more. This result is consistent across regions and independent of the nature of field data. Reasons for this are unknown but it can be hypothesized that the progressive disappearance of females may be associated with mortality caused by anthropogenic factors. This idea is supported by the asymmetric habitat use by the two sexes, with females scavenging in more humanized areas. Whatever the cause, male-skewed adult sex ratios imply that populations of this endangered scavenger face higher risks of extinction than previously believed. PMID:23029488

  1. Osteoporosis in the aging male: Treatment options

    PubMed Central

    Tuck, Stephen P; Datta, Harish K

    2007-01-01

    In elderly women, loss in bone mass and micro-architectural changes are generally attributed to the onset of menopause. Men do not experience menopause, they do, however, experience age-related acceleration in bone loss and micro-architecture deterioration. The incidence of osteoporotic fractures in elderly men, just as in aged women, increases exponentially with age; the rise in men, however, is some 5–10 years later than in women. Up to 50% of male osteoporotics have no identifiable etiology; however elderly males have much higher likelihood of having an identifiable secondary cause than younger men. Therefore, clinical and laboratory evaluation of aged male osteoporotics must be thorough and should be aimed at identifying lifestyle or conditions contributing to bone loss and fragility. It is essential to identify and treat secondary causes and ensure adequate vitamin D and calcium intake before embarking upon treatment with pharmacological agents. The evidence from a limited number of trials suggests that bisphosphonates, especially alendronate and risedronate, are effective in improving BMD, and seem to be the treatments of choice in aged men with osteoporosis. In cases where bisphosphonates are contra-indicated or ineffective, teriparatide or alternatives such as strontium should be considered. PMID:18225452

  2. Osteoporosis in the aging male: treatment options.

    PubMed

    Tuck, Stephen P; Datta, Harish K

    2007-01-01

    In elderly women, loss in bone mass and micro-architectural changes are generally attributed to the onset of menopause. Men do not experience menopause, they do, however, experience age-related acceleration in bone loss and micro-architecture deterioration. The incidence of osteoporotic fractures in elderly men, just as in aged women, increases exponen-tially with age; the rise in men, however, is some 5-10 years later than in women. Up to 50% of male osteoporotics have no identifiable etiology; however elderly males have much higher likelihood of having an identifiable secondary cause than younger men. Therefore, clinical and laboratory evaluation of aged male osteoporotics must be thorough and should be aimed at identifying lifestyle or conditions contributing to bone loss and fragility. It is essential to identify and treat secondary causes and ensure adequate vitamin D and calcium intake before embarking upon treatment with pharmacological agents. The evidence from a limited number of trials suggests that bisphosphonates, especially alendronate and risedronate, are effective in improving BMD, and seem to be the treatments of choice in aged men with osteoporosis. In cases where bisphosphonates are contra-indicated or ineffective, teriparatide or alternatives such as strontium should be considered. PMID:18225452

  3. An evaluation of sex-age-kill (SAK) model performance

    USGS Publications Warehouse

    Millspaugh, Joshua J.; Skalski, John R.; Townsend, Richard L.; Diefenbach, Duane R.; Boyce, Mark S.; Hansen, Lonnie P.; Kammermeyer, Kent

    2009-01-01

    The sex-age-kill (SAK) model is widely used to estimate abundance of harvested large mammals, including white-tailed deer (Odocoileus virginianus). Despite a long history of use, few formal evaluations of SAK performance exist. We investigated how violations of the stable age distribution and stationary population assumption, changes to male or female harvest, stochastic effects (i.e., random fluctuations in recruitment and survival), and sampling efforts influenced SAK estimation. When the simulated population had a stable age distribution and λ > 1, the SAK model underestimated abundance. Conversely, when λ < 1, the SAK overestimated abundance. When changes to male harvest were introduced, SAK estimates were opposite the true population trend. In contrast, SAK estimates were robust to changes in female harvest rates. Stochastic effects caused SAK estimates to fluctuate about their equilibrium abundance, but the effect dampened as the size of the surveyed population increased. When we considered both stochastic effects and sampling error at a deer management unit scale the resultant abundance estimates were within ±121.9% of the true population level 95% of the time. These combined results demonstrate extreme sensitivity to model violations and scale of analysis. Without changes to model formulation, the SAK model will be biased when λ ≠ 1. Furthermore, any factor that alters the male harvest rate, such as changes to regulations or changes in hunter attitudes, will bias population estimates. Sex-age-kill estimates may be precise at large spatial scales, such as the state level, but less so at the individual management unit level. Alternative models, such as statistical age-at-harvest models, which require similar data types, might allow for more robust, broad-scale demographic assessments.

  4. [Mating choice of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae): influence of male ageing on mating success].

    PubMed

    Silva Neto, Alberto M da; Dias, Vanessa S; Joachim-Bravo, Iara S

    2009-01-01

    The objective of this study was to evaluate the effect of male ageing on male pheromone release and mating success of Ceratitis capitata (Wiedemann). The effects of male ageing on mating were evaluated on five and 21 d-old males by assessing their mating success (males chosen by a female for copulation) and the amount of males releasing the sex pheromone. The mating success was evaluated by using several ratios of young to older males by increasing the number of older males:young males from 1:1 to 5:1. The mating success of the 1:1 ratio was also evaluated in field cages. The evaluation of the mating success (in the 1:1 ratio) showed a clear preference of the females for young males. Sex pheromone emission was much more common on young than older males. Even in cases were older males were more abundant (ratios 2:1 and 3:1), females still chose the young males. However, females could not distinguish young from older males in ratios of 4:1 or 5:1. Our data indicate that the ageing of C. capitata males has a considerable negative effect on their reproductive success, especially if they are found in a proportion any lower than 3:1. PMID:19943002

  5. Social context, sexual risk perceptions and stigma: HIV vulnerability among male sex workers in Mombasa, Kenya.

    PubMed

    Okal, Jerry; Luchters, Stanley; Geibel, Scott; Chersich, Matthew F; Lango, Daniel; Temmerman, Marleen

    2009-11-01

    Knowledge about sexual practices and life experiences of men having sex with men in Kenya, and indeed in East Africa, is limited. Although the impact of male same-sex HIV transmission in Africa is increasingly acknowledged, HIV prevention initiatives remain focused largely on heterosexual and mother-to-child transmission. Using data from ten in-depth interviews and three focus group discussions (36 men), this analysis explores social and behavioural determinants of sexual risks among men who sell sex to men in Mombasa, Kenya. Analysis showed a range and variation of men by age and social class. First male same-sex experiences occurred for diverse reasons, including love and pleasure, as part of sexual exploration, economic exchange and coercion. Condom use is erratic and subject to common constraints, including notions of sexual interference and motivations of clients. Low knowledge compounds sexual risk taking, with a widespread belief that the risk of HIV transmission through anal sex is lower than vaginal sex. Traditional family values, stereotypes of abnormality, gender norms and cultural and religious influences underlie intense stigma and discrimination. This information is guiding development of peer education programmes and sensitisation of health providers, addressing unmet HIV prevention needs. Such changes are required throughout Eastern Africa. PMID:19484638

  6. Substance Use among Male Sex Workers in Vietnam: Prevalence, Onset, and Interactions with Sexual Risk

    PubMed Central

    Yu, Gary; Clatts, Michael C.; Goldsamt, Lloyd A.; Giang, Le Minh

    2014-01-01

    Background HIV research in Vietnam has focused primarily on its large heroin injector population. Data on men who have sex with men [MSM], particularly the large and growing population of men who exchange sex for money or other material rewards, male sex workers [MSWs], is very limited. Methods Data derive from a cross-sectional study of MSW, age 16-35, recruited using community sampling methods in three cities in 2010-2011, including Hanoi, Ho Chi Minh City [HCMC], and Nha Trang City (n=710). Assessments included demographic characteristics, substance use, sexual risk, and use of health services. A series of “event” questions were used to assess the influence of alcohol and drugs on sexual risk. Results Both tobacco and alcohol are initiated at a young age and most participants currently use both substances overall across all three cities. While alcohol and tobacco use precede the initiation of sex work, stimulant and opiate use are initiated following the initiation of sex work. There was substantial overlap between substance use and sexual risk, and this overlap was strongest in sexual events involving male and female elective partners rather than sex work clients. Conclusion Although rates of HIV infection in this group are low, this may be an artifact of the young age of the sample. High rates of drug use, including alcohol, tobacco and illicit drugs, coupled with high rates of ulcerative STIs such as HPV, suggest the potential for rapid amplification of STI/HIV risk among MSW and their complex sex partnering networks. PMID:25488636

  7. Looking, Smiling, Laughing, and Moving in Restaurants: Sex and Age Differences.

    ERIC Educational Resources Information Center

    Adams, Robert M.; Kirkevold, Barbara

    Body movements and facial expressions of males and females in a restaurant setting were examined, with the goal of providing differences in frequency as a function of age and sex. The subjects (N-197 males and N=131 females) were seated in three Seattle fast food restaurants and were selected on a semi-random basis and then observed for three…

  8. New pleasures and old dangers: reinventing male sex work.

    PubMed

    Minichiello, Victor; Scott, John; Callander, Denton

    2013-01-01

    Understandings of male sex workers (MSWs) shift with technological, conceptual, and social changes. Research has historically constructed MSWs as psychologically unstable, desperate, or destitute victims and their clients as socially deviant perverts. These perceptions, however, are no longer supported by contemporary research and changing societal perceptions of the sex industry, challenging how we understand and describe "escorts." The changing understandings of sexuality and the increasing power of the Internet are both important forces behind recent changes in the structure and organization of MSWs. The growth in the visibility and reach of escorts has created opportunities to form an occupational account of MSWs that better accounts for the dynamic and diverse nature of the MSW experience in the early 21st century. Recent changes in the structure and organization of male sex work have provided visibility to the increasingly diverse geographical distribution of MSW, the commodification of race and racialized desire, new populations of heterosexual men and women as clients, and the successful dissemination of safer sexual messages to MSWs through online channels. This article provides a broad overview of the literature on MSWs, concentrating its focus on studies that have emerged over the past 20 years and identifying areas for future research. PMID:23480072

  9. Sex education and rehabilitation with schizophrenic male outpatients.

    PubMed

    Lukoff, D; Gioia-Hasick, D; Sullivan, G; Golden, J S; Nuechterlein, K H

    1986-01-01

    Research indicates that schizophrenic patients lack intimate relationships and show a high rate of sexual dysfunction. Despite increasing awareness of the rights of handicapped persons to sexual expression, the treatment of schizophrenic patients rarely addresses their sexuality. A sex education program for recent-onset male schizophrenic patients attending an outpatient clinic was developed in response to several incidents involving patients' inappropriate sexual behaviors. To enhance our understanding of the current sexual functioning and needs of these patients, sex histories were taken. Almost all of the 16 patients interviewed were sexually active, with autoerotic activity predominating. Sixty-three percent of the patients reported orgasmic and/or erectile dysfunctions. Other studies have linked sexual dysfunction to the side effects of antipsychotic medications. The objectives of the sex education program were: to provide information; to clarify values; to overcome sexual dysfunction; and to enhance intimacy skills. The authors used role playing, modeling, group exercises, and explicit sex therapy audiovisual material to improve patients' intimacy skills. Patients participated actively and used the group to explore sexual issues. No exacerbations of symptoms were observed among patients participating in the program. PMID:3027886

  10. Age-concordant and age-discordant sexual behavior among gay and bisexual male adolescents.

    PubMed

    Bruce, Douglas; Harper, Gary W; Fernández, M Isabel; Jamil, Omar B

    2012-04-01

    There is evidence that risks for HIV and sexually transmitted infections among adolescent females are higher for those with older male sexual partners. Yet, little empirical research has been conducted with male adolescents who engage in sexual activity with older men. In this article, we summarize in a number of ways the range of sexual activity reported by an ethnically diverse sample of 200 gay and bisexual male youth (15-22 years old) in Chicago and Miami. A general pattern of progression from oral sex with men to both receptive and insertive anal sex with men appeared to characterize the sample during their adolescence. Further, there appeared to be a high degree of "versatile" positioning among the sexually active gay and bisexual young men, in both age-discrepant and age-concordant dyads. Risk analysis revealed having primarily age-concordant partners to be a significant predictor of sexual risk behavior. HIV risk among young gay and bisexual men engaging in sexual activity with older men may occur not only within a distinct biological context from their heterosexual counterparts, but also in a social context that may not as rigidly bound to traditional assumptions about age, gender, and power. The significant associations among participants with partners who were the same age and the risk behavior measures in this analysis have implications for HIV prevention efforts. PMID:21290255

  11. Shoe midsole hardness, sex and age effects on lower extremity kinematics during running.

    PubMed

    Nigg, Benno M; Baltich, Jennifer; Maurer, Christian; Federolf, Peter

    2012-06-01

    Previous studies investigating the effects of shoe midsole hardness on running kinematics have often used male subjects from within a narrow age range. It is unknown whether shoe midsole hardness has the same kinematic effect on male and female runners as well as runners from different age categories. As sex and age have an effect on running kinematics, it is important to understand if shoe midsole hardness affects the kinematics of these groups in a similar fashion. However, current literature on the effects of sex and age on running kinematics are also limited to a narrow age range distribution in their study population. Therefore, this study tested the influence of three different midsole hardness conditions, sex and age on the lower extremity kinematics during heel-toe running. A comprehensive analysis approach was used to analyze the lower-extremity kinematic gait variables for 93 runners (male and female) aged 16-75 years. Participants ran at 3.33±0.15 m/s on a 30 m-long runway with soft, medium and hard midsoles. A principal component analysis combined with a support vector machine showed that running kinematics based on shoe midsole hardness, sex, and age were separable and classifiable. Shoe midsole hardness demonstrated a subject-independent effect on the kinematics of running. Additionally, it was found that age differences affected the more dominant movement components of running compared to differences due to the sex of a runner. PMID:22507350

  12. An Investigation into the Effect of Respondent Gender, Victim Age, and Perpetrator Treatment on Public Attitudes towards Sex Offenders, Sex Offender Treatment, and Sex Offender Rehabilitation

    ERIC Educational Resources Information Center

    Rogers, Paul; Hirst, Lindsay; Davies, Michelle

    2011-01-01

    In this study the authors examine the effect respondent gender, victim age, and offender treatment programs have upon public attitudes towards sex offenders. A community sample of 235 participants were asked to read a hypothetical vignette involving the sexual assault of a 10-, 15-, or 20-year-old female by a 35-year-old male who subsequently…

  13. A case of sex reversal syndrome with sex-determining region (XX male).

    PubMed

    Yamamoto, M; Yokoi, K; Katsuno, S; Hibi, H; Miyake, K

    1995-12-01

    We examined a 32-year-old man with a 4-year history of infertility. The man's sex life, male hair pattern, and penis were normal, and he had no history of erection problems. Left and right testicular volumes were 2 ml and 3 ml, respectively. Semen analysis showed no sperm. The endocrine panel revealed increased serum luteinizing hormone and follicle-stimulating hormone levels, and a normal serum testosterone level. A testicular biopsy demonstrated that both Leydig cell and Sertoli cell hyperplasia were present, and that no germ cells were found in the tubules. A chromosome analysis done on the peripheral blood lymphocytes revealed a karyotype of 46, XX. We identified the sex-determining region, Y, by polymerase chain reaction using Y-specific probes in this patient. The diagnosis was XX male. PMID:8725494

  14. Male sex workers: practices, contexts, and vulnerabilities for HIV acquisition and transmission.

    PubMed

    Baral, Stefan David; Friedman, M Reuel; Geibel, Scott; Rebe, Kevin; Bozhinov, Borche; Diouf, Daouda; Sabin, Keith; Holland, Claire E; Chan, Roy; Cáceres, Carlos F

    2015-01-17

    Male sex workers who sell or exchange sex for money or goods encompass a very diverse population across and within countries worldwide. Information characterising their practices, contexts where they live, and their needs is limited, because these individuals are generally included as a subset of larger studies focused on gay men and other men who have sex with men (MSM) or even female sex workers. Male sex workers, irrespective of their sexual orientation, mostly offer sex to men and rarely identify as sex workers, using local or international terms instead. Growing evidence indicates a sustained or increasing burden of HIV among some male sex workers within the context of the slowing global HIV pandemic. Several synergistic facilitators could be potentiating HIV acquisition and transmission among male sex workers, including biological, behavioural, and structural determinants. Criminalisation and intersectional stigmas of same-sex practices, commercial sex, and HIV all augment risk for HIV and sexually transmitted infections among male sex workers and reduce the likelihood of these people accessing essential services. These contexts, taken together with complex sexual networks among male sex workers, define this group as a key population underserved by current HIV prevention, treatment, and care services. Dedicated efforts are needed to make those services available for the sake of both public health and human rights. Evidence-based and human rights-affirming services dedicated specifically to male sex workers are needed to improve health outcomes for these men and the people within their sexual networks. PMID:25059939

  15. Correlates of self-efficacy for condom use among male clients of female sex workers in Tijuana, Mexico.

    PubMed

    Volkmann, Tyson; Wagner, Karla D; Strathdee, Steffanie A; Semple, Shirley J; Ompad, Danielle C; Chavarin, Claudia V; Patterson, Thomas L

    2014-05-01

    Male clients of female sex workers (FSWs) in Tijuana, Mexico engage in high levels of unprotected sex. While behavioral change theories posit that self-efficacy predicts condom use, correlates of self-efficacy for condom use remain largely unstudied. We examined these correlates among male clients of FSWs in Tijuana. Eligible male clients were at least 18 years of age, HIV-negative, lived in Tijuana or San Diego, reported unprotected sex with a Tijuana FSW at least once in the past 4 months, and agreed to be treated for sexually transmitted infections (STIs). Participants completed an interviewer-administered questionnaire including demographics, substance use, psychosocial and psychosexual characteristics (e.g., outcome expectancies for negotiation of safer sex, social support, and sexual sensation seeking), and sexual behaviors. Participants also underwent HIV/STI testing. A stepwise hierarchical multiple regression analysis identified correlates of self-efficacy for condom use. Of 393 male clients, median age was 37 years. Participants were mostly Spanish-speaking and employed. Factors independently associated with higher self-efficacy for condom use were higher positive outcome expectancies for negotiation of safer sex, lower sexual sensation seeking scores, and higher social support scores. Both psychosocial and psychosexual factors may influence self-efficacy for condom use among male clients of FSWs. These factors represent central constructs in sociocognitive models that explain behavioral change and could be intervention targets for improving self-efficacy for condom use and, ultimately, safer sex behavior. PMID:23842786

  16. A Note on Sex Differences in Mental Rotation in Different Age Groups

    ERIC Educational Resources Information Center

    Geiser, Christian; Lehmann, Wolfgang; Eid, Michael

    2008-01-01

    A large number of studies have reported average performance differences in favor of males in mental rotation tasks. However, it is still unclear to what extent the magnitude of the sex differences varies across age, and whether the differences increase with age. In this study, we reanalyzed data from a cross-sectional investigation of N = 1624…

  17. Secondary infertility and the aging male, overview

    PubMed Central

    Al–Hawsawi, Khalid; Motair, Wael; Bawa, Abdallah Makhloof

    2014-01-01

    Introduction Old men preparing themselves for marriage late in their lives might face infertility. Infertility in this group of men should be considered from a wider perspective, as they face any age–related health troubles that include, but are not limited to, androgen deficiency and psychological disorders that impede early conception. This review aims to shed light on the proper approach to this minority of secondarily infertile men. Material and methods A comprehensive electronic English literature search was conducted, using various medical websites and books, for the factors that cause infertility in senior fathers. The physiology of geriatric males, together with their common comorbidities, were discussed. Results Old men presenting with secondary infertility should be approached differently. Aging, itself, has a significant impact on male sexual function, sperm parameters, and fertility; all of which contribute to poor fecundability, decreased fertilizing capacity, increased time to pregnancy, increased rate of DNA damage, high abortion rates and increased prevalence of fetal developmental failures. The complexity and the unknowns of the aging male physiology, together with the interaction of obstinate diseases the patient might have, make the issue very difficult to tackle. Conclusions Management should include the conventional way of treating young sufferers and further target the underlying causes, if known, along with the provision of geriatric, psychologic, and andrologic support. PMID:25140235

  18. Sex disparity in colonic adenomagenesis involves promotion by male hormones, not protection by female hormones.

    PubMed

    Amos-Landgraf, James M; Heijmans, Jarom; Wielenga, Mattheus C B; Dunkin, Elisa; Krentz, Kathy J; Clipson, Linda; Ederveen, Antwan G; Groothuis, Patrick G; Mosselman, Sietse; Muncan, Vanesa; Hommes, Daniel W; Shedlovsky, Alexandra; Dove, William F; van den Brink, Gijs R

    2014-11-18

    It recently has been recognized that men develop colonic adenomas and carcinomas at an earlier age and at a higher rate than women. In the Apc(Pirc/+) (Pirc) rat model of early colonic cancer, this sex susceptibility was recapitulated, with male Pirc rats developing twice as many adenomas as females. Analysis of large datasets revealed that the Apc(Min/+) mouse also shows enhanced male susceptibility to adenomagenesis, but only in the colon. In addition, WT mice treated with injections of the carcinogen azoxymethane (AOM) showed increased numbers of colonic adenomas in males. The mechanism underlying these observations was investigated by manipulation of hormonal status. The preponderance of colonic adenomas in the Pirc rat model allowed a statistically significant investigation in vivo of the mechanism of sex hormone action on the development of colonic adenomas. Females depleted of endogenous hormones by ovariectomy did not exhibit a change in prevalence of adenomas, nor was any effect observed with replacement of one or a combination of female hormones. In contrast, depletion of male hormones by orchidectomy (castration) markedly protected the Pirc rat from adenoma development, whereas supplementation with testosterone reversed that effect. These observations were recapitulated in the AOM mouse model. Androgen receptor was undetectable in the colon or adenomas, making it likely that testosterone acts indirectly on the tumor lineage. Our findings suggest that indirect tumor-promoting effects of testosterone likely explain the disparity between the sexes in the development of colonic adenomas. PMID:25368192

  19. Age and sex-related changes in rat brain mitochondrial function.

    PubMed

    Guevara, Rocío; Gianotti, Magdalena; Roca, Pilar; Oliver, Jordi

    2011-01-01

    Aging is responsible for the decline in the function of mitochondria and their increase in size and number--adaptive mechanism to restore mitochondrial function. Estrogens increase mitochondrial function, especially in female rats. The aim of this study was to determine the age-related changes in rat brain mitochondrial function focusing on sex differences. Cellular and mitochondrial protein and DNA content, mitochondrial oxidative and phosphorylative function in male and female rat brain from four different age groups (6, 12, 18 and 24 months old) were analyzed. Mitochondria protein/DNA content decreased with aging shifting toward lesser mitochondrial functional capacity and the mitochondria number increased. A sex dimorphism was determined, with female rat brain showing mitochondria with greater functional capacity than males. These sex differences gradually increased during aging. PMID:21471708

  20. A psychosocial study of male-to-female transgendered and male hustler sex workers in São Paulo, Brazil.

    PubMed

    Prado Cortez, Fernanda Cestaro; Boer, Douglas Pieter; Baltieri, Danilo Antonio

    2011-12-01

    This study examined sociodemographic variables, personality characteristics, and alcohol and drug misuse among male sex workers in the city of Santo André, São Paulo, Brazil. A total of 45 male-to-female transgender sex workers and 41 male hustlers were evaluated in face-to-face interviews at their place of work from 2008 to 2010. A "snowball" sampling procedure was used to access this hard-to-reach population. Male-to-female transgender sex workers reported fewer conventional job opportunities, fewer school problems, and higher harm avoidance and depression levels than male hustlers. Also, transgender sex workers reported earning more money through sex work and more frequently living in hostels with peers than their counterparts. As biological male sex workers are a heterogeneous population, attempts to classify them into distinctive groups should be further carried out as a way to better understand and identify their behavior, design effective health interventions, and consequently minimize the likelihood of unintended adverse outcomes. Our study showed that gender performance can be an important variable to be considered by researchers and policy makers when working with sex workers and developing HIV/AIDS prevention and public health programs, given that transgender and male sex workers not only display distinctive behavior and physical appearance but also reveal differences on specific psychological measures, such as personality traits and depression levels. We recommend that counselors working with this population strike a balance between facilitating self-disclosure and establishing more evidence-based directive interventions. PMID:21667231

  1. Sex, eyes, and vision: male/female distinctions in ophthalmic disorders.

    PubMed

    Eisner, Alvin

    2015-02-01

    There is growing recognition: (1) that sex (male and female) and sex hormones (androgens and estrogens) are important for physiologic functions outside those pertaining expressly to reproduction, and (2) that both classes of sex hormones are active in both sexes, and moreover are produced locally in non-gonadal tissues throughout the body. The visual system, in addition to being of tremendous inherent importance, is unique in a very distinctive way; it possesses an organ - the eye - having a window allowing its interior to be examined with exquisite precision and control in both laboratory and clinical settings. Plus, many diseases manifest in the eye or are exclusive to the eye. This special issue of Current Eye Research contains 12 review articles, each addressing a different topical area important for Sex, Eyes, and Vision: Male/Female Distinctions in Ophthalmic Disorders. Of course, the distinctions between topical areas are blurred, and the overlap between the various lines of knowledge and investigation likewise is substantial. Eye diseases can be both neurodegenerative and involve altered blood flow, for instance. In fact, the thematic overlap is greater yet, in that the articles for this special issue address matters of interest to clinicians and scientists who may identify more with women's health or sex & gender fields than with eye & vision fields. Nevertheless, because this special issue needs a home, the following 12 topical areas each have here their own dedicated review: age-related maculopathy, central nervous system function and cognition & perception, diabetic retinopathy, dry eye, glaucoma, inherited diseases, lens and cataract, neuro-ophthalmology, ocular blood flow, ocular inflammatory disorders, optical coherence tomography, and sex/gender eye care disparities. This overview article itself raises additional points expressly concerning: (1) the estrogen therapy timing hypothesis, and (2) breast cancer treatment with aromatase inhibitors. PMID

  2. Sex chromosome recombination failure, apoptosis, and fertility in male mice.

    PubMed

    Faisal, Imrul; Kauppi, Liisa

    2016-06-01

    Lack of crossing-over in meiosis can trigger an apoptotic response at metaphase I by the spindle assembly checkpoint (SAC). In contrast to females, segregation of sex chromosomes in males poses a particular challenge as recombination and chiasma formation is restricted to the pseudoautosomal region, the small region of homology between X and Y chromosomes. Existing data indicate that low levels of crossover failure in male meiosis can be tolerated without compromising fertility, while high levels of X-Y dissociation (in ≥70 % of cells) result in widespread apoptosis and subsequent infertility, demonstrated earlier, e.g., in Spo11β-only mice. Here, we explore the threshold of X-Y recombination failure frequency that is compatible with fertility. We show that in Spo11β-only(mb) mice with a mixed genetic background, in contrast to Spo11β-only mice with a C57BL/6 background, X-Y pairing fails in ~50 % of cells but this still allows for sperm production without any overt impact on fertility. We also review data on apoptosis and fertility from other achiasmate mouse models and propose that the incidence of homolog dissociation that can be tolerated in vivo without compromising male fertility lies between 50 and 70 %. PMID:26440410

  3. Male prostitutes and safe sex: different settings, different risks.

    PubMed

    de Graaf, R; Vanwesenbeeck, I; van Zessen, G; Straver, C J; Visser, J H

    1994-01-01

    Twenty-seven male prostitutes were interviewed extensively about their work and considerations relating to safe sex with clients. Important differences were found between street prostitutes and those working at home. Street-workers were more likely to be using hard drugs, to have a heterosexual preference, to have no other occupation, to have more clients, but less steady ones, and to have a more negative working attitude. Sexual techniques most often practised were manual and oral contact; however, most prostitutes also practised either insertive or receptive anal intercourse. Homosexual male prostitutes reported more receptive anal intercourse than did their heterosexual male colleagues; but no such differences were found in insertive anal intercourse. Prostitutes were most likely to have had anal intercourse with steady clients, with clients whom they trusted regarding condom use, or with clients they felt sexually attracted to; and also when in dire need of drugs. Of those who had practised anal intercourse in the previous year, a minority had not consistently used condoms. The same factors that encourage anal intercourse also appear conducive to unprotected intercourse. PMID:7948084

  4. Sex and species recognition by wild male southern white rhinoceros using contact pant calls.

    PubMed

    Cinková, Ivana; Policht, Richard

    2016-03-01

    Recognition of information from acoustic signals is crucial in many animals, and individuals are under selection pressure to discriminate between the signals of conspecifics and heterospecifics or males and females. Here, we first report that rhinos use information encoded in their calls to assess conspecifics and individuals of closely related species. The southern (Ceratotherium simum) and critically endangered northern (C. cottoni) white rhinos are the most social out of all the rhinoceros species and use a contact call pant. We found that southern white rhino pant calls provide reliable information about the caller's sex, age class and social situation. Playback experiments on wild territorial southern white rhinoceros males revealed that they responded more strongly to the pant calls of conspecific females compared to the calls of other territorial males. This suggests that pant calls are more important form of communication between males and females than between territorial males. Territorial southern males also discriminated between female and territorial male calls of northern species and reacted more intensively to the calls of northern than southern males. This might be caused by a novelty effect since both species naturally live in allopatry. We conclude that white rhinos can directly benefit from assessing individuals at long distances using vocal cues especially because their eyesight is poor. Pant calls thus likely play a significant role in their social relationships and spatial organization. In addition, better understanding of vocal communication in white rhinos might be helpful in conservation management particularly because of their low reproduction in captivity. PMID:26577089

  5. Bayesian Reconstruction of Two-Sex Populations by Age: Estimating Sex Ratios at Birth and Sex Ratios of Mortality1

    PubMed Central

    Wheldon, Mark C.; Raftery, Adrian E.; Clark, Samuel J.; Gerland, Patrick

    2014-01-01

    Summary The original version of Bayesian reconstruction, a method for estimating age-specific fertility, mortality, migration and population counts of the recent past with uncertainty, produced estimates for female-only populations. Here we show how two-sex populations can be similarly reconstructed and probabilistic estimates of various sex ratio quantities obtained. We demonstrate the method by reconstructing the populations of India from 1971 to 2001, Thailand from 1960 to 2000, and Laos from 1985 to 2005. We found evidence that in India, sex ratio at birth exceeded its conventional upper limit of 1.06, and, further, increased over the period of study, with posterior probability above 0.9. In addition, almost uniquely, we found evidence that life expectancy at birth (e0) was lower for females than for males in India (posterior probability for 1971–1976 equal to 0.79), although there was strong evidence for a narrowing of the gap through to 2001. In both Thailand and Laos, we found strong evidence for the more usual result that e0 was greater for females and, in Thailand, that the difference increased over the period of study. PMID:26612972

  6. Age-Dependent Male Mating Investment in Drosophila pseudoobscura

    PubMed Central

    Dhole, Sumit; Pfennig, Karin S.

    2014-01-01

    Male mating investment can strongly influence fitness gained from a mating. Yet, male mating investment often changes with age. Life history theory predicts that mating investment should increase with age, and males should become less discriminatory about their mate as they age. Understanding age-dependent changes in male behavior and their effects on fitness is important for understanding how selection acts in age-structured populations. Although the independent effects of male or female age have been studied in many species, how these interact to influence male mating investment and fitness is less well understood. We mated Drosophila pseudoobscura males of five different age classes (4-, 8-, 11-, 15-, 19-day old) to either young (4-day) or old (11-day) females, and measured copulation duration and early post-mating fecundity. Along with their independent effects, we found a strong interaction between the effects of male and female ages on male mating investment and fitness from individual matings. Male mating investment increased with male age, but this increase was more prominent in matings with young females. Male D. pseudoobscura made smaller investments when mating with old females. The level of such discrimination based on female age, however, also changed with male age. Intermediate aged males were most discriminatory, while the youngest and the oldest males did not discriminate between females of different ages. We also found that larger male mating investments resulted in higher fitness payoffs. Our results show that male and female ages interact to form a complex pattern of age-specific male mating investment and fitness. PMID:24586373

  7. Sex differences in orbitofrontal connectivity in male and female veterans with TBI.

    PubMed

    McGlade, Erin; Rogowska, Jadwiga; Yurgelun-Todd, Deborah

    2015-09-01

    More female soldiers are now serving in combat theaters than at any other time. However, little is known about possible sex differences underlying the neuropathology and manifestation of one of modern war's signature injuries, traumatic brain injury (TBI). The paucity of information regarding sex differences in TBI is particularly evident when examining changes in executive function and emotion regulation associated with post concussive events. The current study objective was to observe whether patterns of orbitofrontal (OFC) functional connectivity would differ between female veterans with TBI and their male counterparts. The study further sought to determine whether OFC connectivity might be differentially associated with clinical measures of aggression and hostility. Seventeen female veterans and 24 male veterans, age 18 to 25, who met criteria for TBI completed resting state magnetic resonance imaging (MRI) and clinical assessment measures. Imaging data were analyzed using left and right seed regions of the OFC, and regression analyses were conducted to observe the relationship between resting state connectivity and self-reported aggression. Females and males in this study differed in OFC connectivity, with females demonstrating greater connectivity between left and right OFC and parietal and occipital regions and males demonstrating greater connectivity between left and right OFC and frontal and temporal regions. Significant associations between resting state connectivity and clinical measures were found only in male veterans. These findings suggest that TBI may interact with sex-specific patterns of brain connectivity in male and female veterans and exert divergent effects on clinical profiles of aggression post-injury. PMID:25864195

  8. Sex- and age-related variations of the somatotype in a Chuvasha population.

    PubMed

    Kalichman, L; Kobyliansky, E

    2006-01-01

    The aim of this large, cross-sectional study was to describe the age- and sex-related variations of the somatotype, employing Heath and Carter's method, in a Chuvasha population residing in a rural region in central Russia. The investigated sample included 802 males aged 18-89 years (mean 46.9) and 738 females aged 18-90 years (mean 48.6). We evaluated the age and sex differences by one-way ANOVA with somatotype components as dependent variables and sex or age groups as grouping variables. Sex differences of somatotypes appear to be the strongest for endomorphy, with generally higher values in women. Endomorphy in males remained virtually unchanged after 30 years of age, but endomorphy in females kept increasing up to the 6th decade, and then subsequently decreased. Virtually no differences were noted in mesomorphy and a very small difference in ectomorphy between males and females aged 18-30 years. A reduction of sexual dimorphism in all somatotype components after age 70 was also observed. The largest difference of all somatotype components appeared between age groups 18-30 and 31-40 years. Thereafter, somatotypes remained practically unchanged. Mesomorphy continued to increase until the 5th decade in both sexes, while in females, endomorphy continuously increased until their 6th decade. In the 7th and 8th decades, a decrease in mean values was observed. Mesomorphy and ectomorphy showed opposite age-related trends. Results of our study clearly suggest that in physique investigations, the somatotypes need to be studied in each sex separately, and in studies of young people, they need also to be adjusted to age. PMID:16574118

  9. Aging male bodies, health and the reproduction of age relations.

    PubMed

    Pietilä, Ilkka; Ojala, Hanna; King, Neal; Calasanti, Toni

    2013-08-01

    This article explores the ways in which a group of male factory workers uses bodies as bases for hierarchical categorization of men by age in their talk of mundane aspects of their lives. Analysis of interviews about health (4 focus groups and 5 personal interviews) with Finnish working-class men under 40 years old shows that they portray age groups to which they do not belong as careless, even irresponsible toward health and its maintenance. As they categorize youth and old people by age, they leave themselves unmarked by it, providing no vocabulary to describe their own group. Despite their tendency to distance themselves particularly from old people, they also distinguish among older men by familiarity, providing relatively nuanced accounts of their fathers' aging. We discuss the marking of age groups in terms of social inequality and talk of fathers in terms of intergenerational relations. Even family ties among men of diverse ages involve ageism, which familiarity serves both to mitigate and to make less visible. This article documents the maintenance of age inequality in everyday, mundane behavior. PMID:23849422

  10. Sex differences in DNA methylation and expression in zebrafish brain: a test of an extended 'male sex drive' hypothesis.

    PubMed

    Chatterjee, Aniruddha; Lagisz, Malgorzata; Rodger, Euan J; Zhen, Li; Stockwell, Peter A; Duncan, Elizabeth J; Horsfield, Julia A; Jeyakani, Justin; Mathavan, Sinnakaruppan; Ozaki, Yuichi; Nakagawa, Shinichi

    2016-09-30

    The sex drive hypothesis predicts that stronger selection on male traits has resulted in masculinization of the genome. Here we test whether such masculinizing effects can be detected at the level of the transcriptome and methylome in the adult zebrafish brain. Although methylation is globally similar, we identified 914 specific differentially methylated CpGs (DMCs) between males and females (435 were hypermethylated and 479 were hypomethylated in males compared to females). These DMCs were prevalent in gene body, intergenic regions and CpG island shores. We also discovered 15 distinct CpG clusters with striking sex-specific DNA methylation differences. In contrast, at transcriptome level, more female-biased genes than male-biased genes were expressed, giving little support for the male sex drive hypothesis. Our study provides genome-wide methylome and transcriptome assessment and sheds light on sex-specific epigenetic patterns and in zebrafish for the first time. PMID:27259666

  11. Age, sex and other factors in radiation carcinogenesis

    SciTech Connect

    Fry, R.J.M.; Carnes, B.A.

    1988-01-01

    It has been held for a long time that the young are more susceptible than adults to the induction of cancer by radiation. The data in support of that contention are accumulating especially from human studies. In an exposed population a significant fraction of the total population risk may be attributed to the risk associated with those who were young at the time of exposure. Since cancer may not appear for decades after exposure estimates of risk may require models for projecting the lifetime risk. Two such models, additive or absolute risk and multiplicative or relative risk have been used. The appropriateness of the latter model is supported by the finding in mice of a positive relationship between natural incidence and the susceptibility for induction by radiation of solid cancer. The choice of model for leukemias is not clear cut. The incidence of cancer increases with age, but the susceptibility for induction decreases. The incidence of cancers increases to a peak and then begins to decline at different ages, dependent on the type of cancer. Sex-dependent differences in both the natural incidence and the susceptibility for induction of cancer are not restricted to sex organs. For example, the susceptibility for the induction by radiation for myeloid leukemia is greater in males than females, whereas in the case of thymic lymphoma it is vice versa. 25 refs., 5 figs., 3 tabs.

  12. The Size Advantage Model of Sex Allocation in the Protandrous Sex-Changer Crepidula fornicata: Role of the Mating System, Sperm Storage, and Male Mobility.

    PubMed

    Broquet, Thomas; Barranger, Audrey; Billard, Emmanuelle; Bestin, Anastasia; Berger, Rémy; Honnaert, Gaelle; Viard, Frédérique

    2015-09-01

    Sequential hermaphroditism is adaptive when the reproductive value of an individual varies with size or age, and this relationship differs between males and females. In this case, theory shows that the lifetime reproductive output of an individual is increased by changing sex (a hypothesis referred to as the size-advantage model). Sex-linked differences in size-fitness curves can stem from differential costs of reproduction, the mating system, and differences in growth and mortality between sexes. Detailed empirical data is required to disentangle the relative roles of each of these factors within the theory. Quantitative data are also needed to explore the role of sperm storage, which has not yet been considered with sequential hermaphrodites. Using experimental rearing and paternity assignment, we report relationships between size and reproductive success of Crepidula fornicata, a protandrous (male-first) gastropod. Male reproductive success increased with size due to the polygamous system and stacking behavior of the species, but females nonetheless had greater reproductive success than males of the same size, in agreement with the size-advantage theory. Sperm storage appeared to be a critical determinant of success for both sexes, and modeling the effect of sperm storage showed that it could potentially accelerate sex change in protandrous species. PMID:26655357

  13. Maximal lactate values following competitive performance varying according to age, sex and swimming style.

    PubMed

    Avlonitou, E

    1996-03-01

    Peak blood lactate concentration for a given individual in a given event could be considered as indicator of exercise effort, especially if the race is fast as it occurs following competitive swimming events. The present study attempts to describe the postcompetition lactate profile across all the swimming distances and strokes according to the age and sex of the swimmer. Blood samples (100 micro lambda) were taken from an arterialized fingertip of a total of 337 swimmers (171 males and 166 females) at the end of 3rd and 6th minutes of competition over 50 to 1500 meter distances and for the following 3 age group divisions: AGE1 = > 18 years of age, AGE2 = 16-17 years of age and AGE3 = 14-15 years of age. For AGE1 group the subjects who were picked up for testing were all the first three who met the criteria for this age category in the OPEN winter and summer National and Provincial Championships. For AGE2 and AGE3 groups the subjects who were picked up for testing were ranked among the first three in their age group winter and summer National and Provincial Championships. Results showed that the highest mean peak lactate values for groups AGE2 and AGE3 were recorded in 200 medley event for both sexes while for group AGE1 the highest mean peak lactate value was recorded in 200 and 400 meter medley events for males and females respectively. On the other hand, the lowest mean lactate value was recorded in long distance events of 1500 and 800 meters for males and females respectively and for all the age group divisions. Furthermore, swimming performance was related to peak lactate values which subsequently was independent of sex but dependent on age with higher lactate values and older age documented by the subjects with faster times. PMID:8699834

  14. Neuropsychological Sex Differences Associated with Age of Initiated Use Among Young Adult Cannabis Users

    PubMed Central

    Crane, Natania A.; Schuster, Randi Melissa; Mermelstein, Robin J.; Gonzalez, Raul

    2015-01-01

    Introduction Earlier initiation of cannabis use is associated with poorer neuropsychological functioning across several domains. Given well-documented sex differences in neuromaturation during adolescence, initiation of cannabis use during this time may affect neuropsychological functioning differently for males and females. Method In the current study, we examined sex differences in the relationship between age of initiated cannabis use and neuropsychological performance after controlling for amount of lifetime cannabis use in 44 male and 25 female young adult cannabis users. Results We found that an earlier age of initiated use was related to poorer episodic memory, especially immediate recall, in females, but not in males. On the other hand, we found that, surprisingly, an earlier age of initiated use was associated with better decision-making overall. However, exploratory analyses found sex-specific factors associated with decision-making and age of initiated use, specifically that ADHD symptoms in females may drive the relationship between an earlier age of initiated use and better decision-making. Further, an earlier age of initiated use was associated with less education, a lower IQ, and fewer years of mother’s education for females, but more lifetime cannabis use for males. Conclusions Taken together, our findings suggest there are sex-differences in the associations between age of initiated cannabis use and neuropsychological functioning. The current study provides preliminary evidence that males and females may have different neuropsychological vulnerabilities that place them at risk for initiating cannabis use and continued cannabis use, highlighting the importance of examining the impact of cannabis on neuropsychological functioning separately for males and females. PMID:25832823

  15. Elevated Mortality among Birds in Chernobyl as Judged from Skewed Age and Sex Ratios

    PubMed Central

    Møller, Anders Pape; Bonisoli-Alquati, Andrea; Rudolfsen, Geir; Mousseau, Timothy A.

    2012-01-01

    Background Radiation has negative effects on survival of animals including humans, although the generality of this claim is poorly documented under low-dose field conditions. Because females may suffer disproportionately from the effects of radiation on survival due to differences in sex roles during reproduction, radiation-induced mortality may result in male-skewed adult sex ratios. Methodology/Principal Finding We estimated the effects of low-dose radiation on adult survival rates in birds by determining age ratios of adults captured in mist nets during the breeding season in relation to background radiation levels around Chernobyl and in nearby uncontaminated control areas. Age ratios were skewed towards yearlings, especially in the most contaminated areas, implying that adult survival rates were reduced in contaminated areas, and that populations in such areas could only be maintained through immigration from nearby uncontaminated areas. Differential mortality in females resulted in a strongly male-skewed sex ratio in the most contaminated areas. In addition, males sang disproportionately commonly in the most contaminated areas where the sex ratio was male skewed presumably because males had difficulty finding and acquiring mates when females were rare. The results were not caused by permanent emigration by females from the most contaminated areas because none of the recaptured birds had changed breeding site, and the proportion of individuals with morphological abnormalities did not differ significantly between the sexes for areas with normal and higher levels of contamination. Conclusions/Significance These findings are consistent with the hypothesis that the adult survival rate of female birds is particularly susceptible to the effects of low-dose radiation, resulting in male skewed sex ratios at high levels of radiation. Such skewed age ratios towards yearlings in contaminated areas are consistent with the hypothesis that an area exceeding 30,000 km2 in

  16. Competition and Habitat Quality Influence Age and Sex Distribution in Wintering Rusty Blackbirds

    PubMed Central

    Mettke-Hofmann, Claudia; Hamel, Paul B.; Hofmann, Gerhard; Zenzal Jr., Theodore J.; Pellegrini, Anne; Malpass, Jennifer; Garfinkel, Megan; Schiff, Nathan

    2015-01-01

    Bird habitat quality is often inferred from species abundance measures during the breeding and non-breeding season and used for conservation management decisions. However, during the non-breeding season age and sex classes often occupy different habitats which suggest a need for more habitat-specific data. Rusty Blackbird (Euphagus carolinus) is a forested wetland specialist wintering in bottomland hardwood forests in the south-eastern U. S. and belongs to the most steeply declining songbirds in the U.S. Little information is available to support priority birds such as the Rusty Blackbird wintering in this threatened habitat. We assessed age and sex distribution and body condition of Rusty Blackbirds among the three major habitats used by this species in the Lower Mississippi Alluvial Valley and also measured food availability. Overall, pecan groves had the highest biomass mainly driven by the amount of nuts. Invertebrate biomass was highest in forests but contributed only a small percentage to overall biomass. Age and sex classes were unevenly distributed among habitats with adult males primarily occupying pecan groves containing the highest nut biomass, females being found in forests which had the lowest nut biomass and young males primarily staying in forest fragments along creeks which had intermediate nut biomass. Males were in better body condition than females and were in slightly better condition in pecan groves. The results suggest that adult males occupy the highest quality habitat and may competitively exclude the other age and sex classes. PMID:25946335

  17. Competition and habitat quality influence age and sex distribution in wintering rusty blackbirds.

    PubMed

    Mettke-Hofmann, Claudia; Hamel, Paul B; Hofmann, Gerhard; Zenzal, Theodore J; Pellegrini, Anne; Malpass, Jennifer; Garfinkel, Megan; Schiff, Nathan; Greenberg, Russell

    2015-01-01

    Bird habitat quality is often inferred from species abundance measures during the breeding and non-breeding season and used for conservation management decisions. However, during the non-breeding season age and sex classes often occupy different habitats which suggest a need for more habitat-specific data. Rusty Blackbird (Euphagus carolinus) is a forested wetland specialist wintering in bottomland hardwood forests in the south-eastern U. S. and belongs to the most steeply declining songbirds in the U.S. Little information is available to support priority birds such as the Rusty Blackbird wintering in this threatened habitat. We assessed age and sex distribution and body condition of Rusty Blackbirds among the three major habitats used by this species in the Lower Mississippi Alluvial Valley and also measured food availability. Overall, pecan groves had the highest biomass mainly driven by the amount of nuts. Invertebrate biomass was highest in forests but contributed only a small percentage to overall biomass. Age and sex classes were unevenly distributed among habitats with adult males primarily occupying pecan groves containing the highest nut biomass, females being found in forests which had the lowest nut biomass and young males primarily staying in forest fragments along creeks which had intermediate nut biomass. Males were in better body condition than females and were in slightly better condition in pecan groves. The results suggest that adult males occupy the highest quality habitat and may competitively exclude the other age and sex classes. PMID:25946335

  18. Sex- and age-related variation in metal content of penguin feathers.

    PubMed

    Squadrone, Stefania; Abete, Maria Cesarina; Brizio, Paola; Monaco, Gabriella; Colussi, Silvia; Biolatti, Cristina; Modesto, Paola; Acutis, Pier Luigi; Pessani, Daniela; Favaro, Livio

    2016-03-01

    The presence of xenobiotics, such as metals, in ecosystems is concerning due to their durability and they pose a threat to the health and life of organisms. Moreover, mercury can biomagnify in many marine food chains and, therefore, organisms at higher trophic levels can be adversely impacted. Although feathers have been used extensively as a bio-monitoring tool, only a few studies have addressed the effect of both age and sex on metal accumulation. In this study, the concentrations of trace elements were determined in the feathers of all members of a captive colony of African Penguins (Spheniscus demersus) housed in a zoological facility in Italy. Tests were performed by inductively coupled plasma-mass spectrometry to detect aluminum, arsenic, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, selenium, tin, vanadium, and zinc. Mercury was detected by a direct mercury analyzer. Sexing was performed by a molecular approach based on analyzing the chromo-helicase-DNA-binding1 gene, located on the sex chromosomes. Sex- and age-related differences were studied in order to investigate the different patterns of metal bioaccumulation between male and female individuals and between adults and juveniles. Juvenile females had significantly higher arsenic levels than males, while selenium levels increased significantly with age in both sexes. Penguins kept in controlled environments-given that diet and habitat are under strict control-represent a unique opportunity to determine if and how metal bioaccumulation is related to sex and age. PMID:26597735

  19. Age and Sex Ratios in a High-Density Wild Red-Legged Partridge Population.

    PubMed

    Nadal, Jesús; Ponz, Carolina; Margalida, Antoni

    2016-01-01

    The dynamics of a wild red-legged partridge population were examined over a 14-year period in Spain to identify patterns in age and sex ratios in relation to weather parameters, and to assess the importance of these parameters in population dynamics and management. The results gave age ratios of 1.07 (but 2.13 in July counts), juvenile sex ratios of 1.01 and adult sex ratios of 1.47. Overall, 12% more females were hatched and female juvenile mortality was 7.3% higher than in males. Sex differential mortality explains the 19.2% deficit in adult females, which are more heavily predated than males during the breeding period. Accordingly, age ratios are dependent on sex ratios and both are density dependent. Over time, ratios and density changes appear to be influenced by weather and management. When the habitat is well conserved, partridge population dynamics can be explained by a causal chain: weather operates on net primary production, thereby affecting partridge reproduction and predation and, as a result, age and sex ratios in the October population. A reduction in the impact of predation (i.e. the effects of ground predators on eggs, chicks and breeding females) is the key factor to improve the conservation of partridge populations and associated biological processes. PMID:27508503

  20. Age and Sex Ratios in a High-Density Wild Red-Legged Partridge Population

    PubMed Central

    Nadal, Jesús; Ponz, Carolina; Margalida, Antoni

    2016-01-01

    The dynamics of a wild red-legged partridge population were examined over a 14-year period in Spain to identify patterns in age and sex ratios in relation to weather parameters, and to assess the importance of these parameters in population dynamics and management. The results gave age ratios of 1.07 (but 2.13 in July counts), juvenile sex ratios of 1.01 and adult sex ratios of 1.47. Overall, 12% more females were hatched and female juvenile mortality was 7.3% higher than in males. Sex differential mortality explains the 19.2% deficit in adult females, which are more heavily predated than males during the breeding period. Accordingly, age ratios are dependent on sex ratios and both are density dependent. Over time, ratios and density changes appear to be influenced by weather and management. When the habitat is well conserved, partridge population dynamics can be explained by a causal chain: weather operates on net primary production, thereby affecting partridge reproduction and predation and, as a result, age and sex ratios in the October population. A reduction in the impact of predation (i.e. the effects of ground predators on eggs, chicks and breeding females) is the key factor to improve the conservation of partridge populations and associated biological processes. PMID:27508503

  1. Age and sex differences in behaviors mediated by the ventromedial hypothalamus.

    PubMed

    Nisbett, R E; Braver, A; Jusela, G; Kezur, D

    1975-02-01

    Age and sex differences in behaviors mediated by the ventromedial hypothalamus (VMH) were examined in the rat. Circadian rhythm, emotionality, and taste responsiveness (except for responsiveness to quinine adulteration) were found to shift, in one or both sexes, toward a pattern suggesting decreased VMH functioning with increasing age. A post hoc analysis of the configuration of positive and negative results suggests that, for those behaviors known to show both immediate and sustained effects of VMH lesion, male rats show a marked trend toward the lesioned pattern of behavior with increasing age, whereas females show weaker or nonexistent age trends in the same behaviors. For those behaviors that have been shown to change only during the static, obese phase, or for which data re controversial as to whether changes take place as a result of the VMH lesion at all, this age and sex pattern does not emerge. PMID:1150946

  2. Autosomal gsdf acts as a male sex initiator in the fish medaka

    PubMed Central

    Zhang, Xi; Guan, Guijun; Li, Mingyou; Zhu, Feng; Liu, Qizhi; Naruse, Kiyoshi; Herpin, Amaury; Nagahama, Yoshitaka; Li, Jiale; Hong, Yunhan

    2016-01-01

    Sex is pivotal for reproduction, healthcare and evolution. In the fish medaka, the Y-chromosomal dmy (also dmrt1bY) serves the sex determiner, which activates dmrt1 for male sex maintenance. However, how dmy makes the male decision via initiating testicular differentiation has remained unknown. Here we report that autosomal gsdf serves a male sex initiator. Gene addition and deletion revealed that gsdf was necessary and sufficient for maleness via initiating testicular differentiation. We show that gsdf transcription is activated directly by dmy. These results establish the autosomal gsdf as the first male sex initiator. We propose that dmy determines maleness through activating gsdf and dmrt1 without its own participation in developmental processes of sex initiation and maintenance. gsdf may easily become a sex determiner or other autosomal genes can be recruited as new sex determiners to initiate gsdf expression. Our findings offer new insights into molecular mechanisms underlying sex development and evolution of sex-controlling genes in vertebrates. PMID:26813267

  3. Identifying sex and age of apapane and iiwi on Hawaii

    USGS Publications Warehouse

    Fancy, S.G.; Pratt, T.K.; Lindsey, G.D.; Harada, C.K.; Parent, A.H., Jr.; Jacobi, J.D.

    1993-01-01

    Methods to determine the sex and age of Apapane (Himatione sanguinea) and Iiwi (Vestiaria coccinea) were developed on the basis of 189 museum specimens and 91 live birds captured in mist nets on the Island of Hawaii (USA). Both species retain all juvenal primaries and some juvenal secondaries and body feathers after the first prebasic molt and attain full adult plumage after the second prebasic molt. Apapane in their first basic plumage retain some buff-edged juvenal secondaries (particularly secondaries five and six) and sometimes retain a few gray-brown feathers on the head. The first basic plumage of Iiwi is characterized by secondaries 6-9 being longer and darker than secondaries 1-4 and the presence of a few yellowish juvenal body feathers with black spots at the tips. Adult male Apapane and Iiwi have longer wing, tail, exposed culmen, culmen and tarso-metatarsus lengths than females. Linear discriminant functions are presented to sex adult Apapane and Iiwi from lengths of their wing chord and exposed culmen.

  4. Female and Male Sex Offenders: A Comparison of Recidivism Patterns and Risk Factors

    ERIC Educational Resources Information Center

    Freeman, Naomi J.; Sandler, Jeffrey C.

    2008-01-01

    Few studies have empirically validated the assertion that female and male sex offenders are vastly different. Therefore, utilizing a matched sample of 780 female and male sex offenders in New York State, the current study explored differences and similarities of recidivism patterns and risk factors for the two offender groups. Results suggested…

  5. Heterosexuals' Attitudes toward Lesbianism and Male Homosexuality: Their Affective Orientation toward Sexuality and Sex Guilt.

    ERIC Educational Resources Information Center

    Yarber, William L.; Yee, Bernadette

    1983-01-01

    A study sought to determine if a relationship existed between heterosexual college students' attitudes toward lesbianism and male homosexuality and their feelings about their own sexuality, including sex guilt. High sex guilt proved to be related to negative attitudes toward homosexuals of both sexes. (Authors/PP)

  6. Romanticism as a function of age, sex, and ethnicity.

    PubMed

    Regan, Pamela C; Anguiano, Carlos

    2010-12-01

    This study examined the association between romanticism (operationalized as mean score on the Romantic Beliefs Scale) and age, sex, and ethnicity in a large community sample (N = 436). Age was negatively correlated with romanticism scores; as age increased, romanticism scores decreased. No sex differences were found; men and women had similar, moderate scores. Although ethnicity largely was unrelated to romanticism, Asian/Pacific Islander participants were significantly more romantic than were African-American participants. PMID:21323155

  7. Age- and sex-specific mortality and population structure in sea otters

    USGS Publications Warehouse

    Bodkin, J.L.; Burdin, A.M.; Ryazanov, D.A.

    2000-01-01

    We used 742 beach-cast carcasses to characterize age- and sex-specific sea otter mortality during the winter of 1990-1991 at Bering Island, Russia. We also examined 363 carcasses recovered after the 1989 grounding of the T/V Exxon Valdez, to characterize age and sex composition in the living western Prince William Sound (WPWS) sea otter population. At Bering Island, mortality was male-biased (81%), and 75% were adults. The WPWS population was female-biased (59%) and most animals were subadult (79% of the males and 45% of the females). In the decade prior to 1990-1991 we found increasing sea otter densities (particularly among males), declining prey resources, and declining weights in adult male sea otters at Bering Island. Our findings suggest the increased mortality at Bering Island in 1990-1991 was a density-dependent population response. We propose male-maintained breeding territories and exclusion of juvenile females by adult females, providing a mechanism for potentially moderating the effects of prey reductions on the female population. Increased adult male mortality at Bearing Island in 1990-1991 likely modified the sex and age class structure there toward that observed in Prince William Sound.

  8. Male Clients of Male Sex Workers in China: An Ignored High-Risk Population

    PubMed Central

    Chen, Lei; Mahapatra, Tanmay; Fu, Gengfeng; Huang, Shujie; Zheng, Heping; Tucker, Joseph D.; Yang, Bin; Zhao, Jinkou; Detels, Roger

    2016-01-01

    Background: There is a high prevalence of HIV/syphilis among male sex workers, but no formal study has ever been conducted focusing on male clients of male sex workers (MCM). A detailed investigation was thus called for, to determine the burden and sociobehavioral determinants of HIV and syphilis among these MCM in China. Methods: As part of a multicenter cross-sectional study, using respondent-driven and snowball sampling, 2958 consenting adult men who have sex with men (MSM) were recruited, interviewed, and tested for HIV and syphilis between 2008 and 2009. The distributions of sociodemographic characteristics, risk behaviors, and HIV/syphilis prevalence were determined and compared between MCM and other MSM. Results: Among recruited MSM, 5.0% (n = 148) were MCM. HIV prevalences for MCM and other MSM were 7.4% and 7.7%, whereas 18.9% and 14.0% were positive for syphilis, respectively. Condomless anal intercourse (CAI) was reported by 59.5% of MCM and 48.2% of MSM. Multiple logistic regression revealed that compared with other MSM, MCM were more likely to have less education [for ≤elementary level, adjusted odds ratio (aOR) = 3.13, 95% confidence interval (95% CI): 1.42 to 6.90], higher income (for >500 US Dollars per month, aOR = 2.97, 95% CI: 1.53 to 5.77), more often found partners at parks/restrooms (aOR = 4.01, 95% CI: 2.34 to 6.85), reported CAI (aOR = 1.49, 95% CI: 1.05 to 2.10), reported a larger sexual network (for ≥10, aOR = 2.70, 95% CI: 1.44 to 5.07), and higher odds of syphilis (aOR = 1.54, 95% CI: 1.00 to 2.38). Conclusions: The greater frequency of risk behaviors and high prevalence of HIV and syphilis indicated that HIV/syphilis prevention programs in China need to pay special attention to MCM as a distinct subgroup, which was completely ignored until date. PMID:26871882

  9. From Client to Pimp: Male Violence against Female Sex Workers

    ERIC Educational Resources Information Center

    Karandikar, Sharvari; Prospero, Moises

    2010-01-01

    The present study explores intimate partner violence (IPV) among female sex workers from the red-light area based in Mumbai, India. Using a grounded theory approach, in-depth interviews were conducted with ten sex workers to explore their experiences of IPV in the context of commercial sex work. Narratives were analyzed and themes constructed. A…

  10. An Investigation of Sex-Related Slang Vocabulary and Sex-Role Orientation Among Male and Female University Students

    ERIC Educational Resources Information Center

    Kutner, Nancy G.; Brogan, Donna

    1974-01-01

    Undergraduate males, undergraduate females, and graduate student nurses (female) were asked to list all the slang expressions they knew for 17 sex-related stimulus words. Males listed a significantly larger total number of slang expressions than either female group. (Author)

  11. Selective aggressiveness in European free-tailed bats ( Tadarida teniotis): influence of familiarity, age and sex

    NASA Astrophysics Data System (ADS)

    Ancillotto, Leonardo; Russo, Danilo

    2014-03-01

    Bats are highly social mammals that often form large groups and represent good models to test the role played by individual status in shaping social relationships. Social cohesion relies on the ability of group and individual recognition, which is mediated by a range of sensorial cues. In this study, we selected the European free-tailed bat Tadarida teniotis as a model species to test the effects of familiarity, sex and age on aggressiveness and mutual tolerance. We hypothesize that T. teniotis is able to recognize group members and exhibit selective aggressiveness, and thus we predict fewer aggressive events and more amicable encounters between colony mates than between strangers. As female bats are generally more sociable and perform prolonged parental care to juveniles even after weaning, we hypothesize that sex and age of bats have significant influences on aggressive behaviours and thus predict that females will perform more amicable behaviours than males and that adults of both sexes will be less aggressive towards juveniles. Our results confirm that T. teniotis is able to discriminate between familiar and stranger individuals, showing higher rates of aggressive behaviours towards the latter. Females are more prone to exhibit amicable behaviours, particularly during same-sex interactions, while males show higher level of aggressiveness. Juveniles are subjected to fewer aggressive behaviours by adults of both sexes. Familiarity appears crucial for T. teniotis in determining the degree of aggressiveness during social interactions but the rate of aggressive events is also influenced by intrinsic individual factors such as sex and age.

  12. Fluorochemicals used in food packaging inhibit male sex hormone synthesis

    SciTech Connect

    Rosenmai, A.K.; Nielsen, F.K.; Pedersen, M.; Hadrup, N.; Trier, X.; Christensen, J.H.; Vinggaard, A.M.

    2013-01-01

    synthesis of male sex hormones. ► Generally, levels of estrogens and cortisol stayed unaffected or increased. ► The effect on steroid synthesis was specific on gene expression of Bzrp and CYP19.

  13. Influence of host fruit and conspecifics on the release of the sex pheromone By Toxotrypana curvicauda males (Diptera: Tephritidae).

    PubMed

    Robledo, Norma; Arzuffi, René

    2012-04-01

    The release of tephritid sex pheromones depends significantly on the age of the male, the social context (presence of conspecifics) and chemical context (host volatiles). In this study, the influence of host fruit and conspecific (males and females) on the emission of the pheromonal compound 2-methyl-6-vinylpyrazine (2,6 mvp) by Toxotrypana curvicauda (Gerstaecker) males was investigated under laboratory conditions. Males were divided into one control group (nonexposed to treatment) and five experimental groups were placed 1 hr before volatile collection with: 1) host fruit (unripe papaya), 2) two females, 3) two males, 4) host fruit plus two females, and 5) host fruit plus two males. The volatiles were sampled by means of solid phase microextraction and analyzed with gas chromatography-mass spectrometry, with a focus on 2,6 mvp. Males emitted volatiles from the first day after adult emergence. The maximum peak and the temporal pattern of 2,6 mvp release were modified by the presence of host fruit and conspecific males or females. On day 5, males in the presence of fruit maintained a constant release of 2,6 mvp while the presence of conspecific caused a decrease of pheromone release. The release of 2,6 mvp was increased significantly in males exposed to both types of stimuli simultaneously. The stimuli (fruit and conspecifics) modified the release of 2,6 mvp, however the effect depended on male age. PMID:22507013

  14. Sexual practices, partner concurrency and high rates of sexually transmissible infections among male sex workers in three cities in Vietnam

    PubMed Central

    Clatts, Michael C.; Goldsamt, Lloyd A.; Giang, Le Minh; Yu, Gary

    2015-01-01

    Background This paper examines sexual practices, partner concurrency and sexually transmissible infections (STI)/HIV infection among male sex workers (MSWs) in Vietnam. Methods Six hundred and fifty-four MSWs, aged 16–35 years, were recruited in Hanoi, Nha Trang and Ho Chi Minh City between 2009 and 2011. Survey measures included demographic characteristics, drug use, types of sexual partners and sexual practices. Subjects were screened for STIs, including HIV. Results MSWs in Ho Chi Minh City (33%) were more likely than those from the other two sites to be current users of one or more types of illegal drugs (P < 0.001). MSWs with both male and female elective partners (compared with other partnership types) were more likely to have anal sex with male client partners (P < 0.001), elective male partners (P = 0.045) and elective female partners (P = 0.025). At last sex with a male client partner, only 30% used a condom during anal intercourse. At last sex with an elective female partner, only 31% used a condom during vaginal sex and only 3% during anal sex. Although rates of HIV are low (4%), other STIs are high, including chlamydia (17%), gonorrhoea (29%) and human papillomavirus (33%). Most (57.3%) have never been tested for HIV and only 17% have ever disclosed to a healthcare provider that they have sex with men. Conclusions Complex patterns of sexual concurrency, coupled with high rates of STIs, signal the urgent need for health services interventions among MSWs, both to improve individual health outcomes and to reduce secondary STI/HIV transmission among sexual partner networks. PMID:25622225

  15. Unreported Male Sex Partners Among Men with Newly Diagnosed HIV Infection - North Carolina, 2011-2013.

    PubMed

    Wu, Hsiu; Hightow-Weidman, Lisa B; Gay, Cynthia L; Zhang, Xinjian; Beagle, Steve; Hall, Laura; Jackson, Tonyka; Marmorino, Jenni; Do, Ann N; Peters, Philip J

    2015-09-25

    Human immunodeficiency virus (HIV) prevention interventions, such as preexposure prophylaxis (PrEP), are often targeted to men who have sex with men (MSM) who self-report high-risk behaviors. Data from a prospective study evaluating methods to detect acute HIV infection among a primarily young (aged <25 years) and black or African American (African American) population from North Carolina were analyzed. In the study, participants were asked about risk behaviors during pretest counseling (at the time of testing) and then during a partner services interview (at HIV diagnosis). Participants whose disclosure of sexual risk behaviors during pretest counseling was different from their disclosure of sexual risk behaviors during their partner services interview were identified, and factors associated with these discordant responses were examined. Among 113 HIV-infected men, 26 (23.0%) did not disclose male sex partners at pretest counseling, but subsequently did disclose this information during their partner services interview. When compared with men who disclosed having male partners at pretest counseling, these 26 MSM who did not disclose male partners during pretest counseling were found to have a similar number of male partners during contact tracing, but were more likely to have a female partner (30.8% versus 6.9%). In addition, the proportions of MSM found to have at least one HIV-infected partner were similar for both groups (MSM who disclosed having male partners during pretest counseling and those who did not). To better customize HIV prevention interventions for MSM, HIV prevention programs might consider using novel strategies to accurately assess risk in this population. PMID:26401589

  16. Variations in Dream Recall Frequency and Dream Theme Diversity by Age and Sex

    PubMed Central

    Nielsen, Tore

    2012-01-01

    We assessed dream recall frequency (DRF) and dream theme diversity (DTD) with an internet questionnaire among a cohort of 28,888 male and female participants aged 10–79 years in a cross-sectional design. DRF increased from adolescence (ages 10–19) to early adulthood (20–29) and then decreased again for the next 20 years. The nature of this decrease differed for males and females. For males, it began earlier (30–39), proceeded more gradually, and reached a nadir earlier (40–49) than it did for females. For females, it began later (40–49), dropped more abruptly, and reached nadir later (50–59). Marked sex differences were observed for age strata 10–19 through 40–49 and year-by-year analyses estimated the window for these differences to be more precisely from 14 to 44 years. DTD decreased linearly with age for both sexes up to 50–59 and then dropped even more sharply for 60–79. There was a sex difference favoring males on this measure but only for ages 10–19. Findings replicate, in a single sample, those from several previous studies showing an increase in DRF from adolescence to early adulthood, a subsequent decrease primarily in early and middle adulthood, and different patterns of age-related decrease in the two sexes. Age-related changes in sleep structure, such as decreasing %REM sleep which parallel the observed dream recall changes, might help explain these findings, but these sleep changes are much smaller and more gradual in nature. Changes in the phase and amplitude of circadian rhythms of REM propensity and generational differences in life experiences may also account for some part of the findings. That decreases in DTD parallel known age-related decreases in episodic and autobiographical memory may signify that this new diversity measure indexes an aspect of autobiographical memory that also influences dream recall. PMID:22783222

  17. Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing.

    PubMed

    Immonen, E; Collet, M; Goenaga, J; Arnqvist, G

    2016-03-01

    Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex differences in the efficacy of selection on mitonuclear genotypes that should result in differences between females and males in mitochondrial genetic effects. Mitonuclear genotype of a focal individual may also indirectly affect trait expression in the mating partner. We tested these predictions in the seed beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis not only affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners (fecundity, egg size, longevity). These results demonstrate important consequences of sex-specific mitonuclear epistasis for both mating partners, consistent with a role for mitonuclear genetic constraints upon sex-specific adaptive evolution. PMID:26732015

  18. Sternal Gland Scent-Marking Signals Sex, Age, Rank, and Group Identity in Captive Mandrills.

    PubMed

    Vaglio, Stefano; Minicozzi, Pamela; Romoli, Riccardo; Boscaro, Francesca; Pieraccini, Giuseppe; Moneti, Gloriano; Moggi-Cecchi, Jacopo

    2016-02-01

    Mandrills are one of the few Old World primates to show scent-marking. We combined ethological and chemical approaches to improve our understanding of this behavior in 3 zoo-managed groups. We observed the olfactory behavior performed by adults and adolescents (N = 39) for 775h. We investigated the volatile components of sternal scent-marks using gas chromatography-mass spectrometry and compared volatile profiles with traits of the signaler. Males marked more than females and within each sex the frequency of scent-marking was related to age and dominance status, but alpha males scent-marked most frequently and particularly in specific areas at the enclosure boundaries. We identified a total of 77 volatile components of sternal gland secretion, including compounds functioning as male sex pheromones in other mammals, in scent-marks spontaneously released on filter paper by 27 male and 18 female mandrills. We confirmed our previous findings that chemical profiles contain information including sex, male age and rank, and we also found that odor may encode information about group membership in mandrills. Our results support the hypotheses that scent-marking signals the status of the dominant male as well as playing territorial functions but also suggest that it is part of sociosexual communication. PMID:26708734

  19. Hormetic protection of Drosophila melanogaster middle-aged male flies from heat stress by mildly stressing them at young age

    NASA Astrophysics Data System (ADS)

    Bourg, Éric

    2005-06-01

    Previous studies have shown that exposing flies to hypergravity (3g or 5g) for the first 2 weeks of adult life slightly increases longevity of male flies and survival time at 37°C for both sexes, and delays an age-linked behavioral change. The present experiment tested whether the hypergravity could also protect flies from four successive deleterious non-lethal heat shocks at 4 and 5 weeks of age. Males that lived in hypergravity for the first 2 weeks of adult life lived slightly longer (ca. +15% or 1.2 day) after heat shocks (30 min or 45 min at 37°C) than flies that always lived at 1g, but this positive effect of hypergravity was not observed in females. Therefore, hypergravity exposure at young age can help the male flies recovering from a heat shock at older ages.

  20. Sex chromosomes and male ornaments: a comparative evaluation in ray-finned fishes

    PubMed Central

    Mank, Judith E; Hall, David W; Kirkpatrick, Mark; Avise, John C

    2005-01-01

    Theory predicts that the mechanism of genetic sex determination can substantially influence the evolution of sexually selected traits. For example, female heterogamety (ZZ/ZW) can favour the evolution of extreme male traits under Fisher's runaway model of sexual selection. We empirically test whether the genetic system of sex determination has played a role in the evolution of exaggerated male ornaments in actinopterygiian fishes, a clade in which both female-heterogametic and male-heterogametic systems of sex determination have evolved multiple times. Using comparative methods both uncorrected and corrected for phylogenetic non-independence, we detected no significant correlation between sex-chromosome systems and sexually selected traits in males. Results suggest that sex-determination mechanism is at best a relatively minor factor affecting the outcomes of sexual selection in ray-finned fishes. PMID:16555792

  1. Double-strand break repair on sex chromosomes: challenges during male meiotic prophase

    PubMed Central

    Lu, Lin-Yu; Yu, Xiaochun

    2015-01-01

    During meiotic prophase, DNA double-strand break (DSB) repair-mediated homologous recombination (HR) occurs for exchange of genetic information between homologous chromosomes. Unlike autosomes or female sex chromosomes, human male sex chromosomes X and Y share little homology. Although DSBs are generated throughout male sex chromosomes, homologous recombination does not occur for most regions and DSB repair process is significantly prolonged. As a result, male sex chromosomes are coated with many DNA damage response proteins and form a unique chromatin structure known as the XY body. Interestingly, associated with the prolonged DSB repair, transcription is repressed in the XY body but not in autosomes, a phenomenon known as meiotic sex chromosome inactivation (MSCI), which is critical for male meiosis. Here using mice as model organisms, we briefly summarize recent progress on DSB repair in meiotic prophase and focus on the mechanism and function of DNA damage response in the XY body. PMID:25565522

  2. Sex-Biased Temporal Gene Expression in Male and Female Floral Buds of Seabuckthorn (Hippophae rhamnoides)

    PubMed Central

    Chawla, Aseem; Stobdan, Tsering; Srivastava, Ravi B.; Jaiswal, Varun; Chauhan, Rajinder S.; Kant, Anil

    2015-01-01

    Seabuckthorn is an economically important dioecious plant in which mechanism of sex determination is unknown. The study was conducted to identify seabuckthorn homologous genes involved in floral development which may have role in sex determination. Forty four putative Genes involved in sex determination (GISD) reported in model plants were shortlisted from literature survey, and twenty nine seabuckthorn homologous sequences were identified from available seabuckthorn genomic resources. Of these, 21 genes were found to differentially express in either male or female flower bud stages. HrCRY2 was significantly expressed in female flower buds only while HrCO had significant expression in male flowers only. Among the three male and female floral development stages (FDS), male stage II had significant expression of most of the GISD. Information on these sex-specific expressed genes will help in elucidating sex determination mechanism in seabuckthorn. PMID:25915052

  3. Perceived stigma of purchasing sex among Latino and non-Latino male clients of female sex workers in Tijuana, Mexico

    PubMed Central

    Pitpitan, Eileen V.; Strathdee, Steffanie A.; Semple, Shirley J.; Wagner, Karla D.; Chavarin, Claudia V.; Earnshaw, Valerie A.; Patterson, Thomas L.

    2013-01-01

    HIV prevention efforts must be comprehensive in their understanding of the factors involved in HIV risk. Male clients, who have received less research attention than female sex workers (FSWs), may experience stigma as a function of purchasing sex. Perceived stigma may be related to poor psychological outcomes, risky psychosexual characteristics, and higher drug and sexual risk behavior among male clients of FSWs. However, perceived stigma of purchasing sex may differ between clients of different ethnic groups. In the present study, we examine the correlates of perceived stigma of purchasing sex among Latino vs. non-Latino male clients of FSWs in Tijuana, Mexico. Using time-location sampling, we recruited 375 male clients (323 Latino, 52 non-Latino) in Tijuana who completed a computerized survey on various measures. We measured perceived stigma of purchasing sex using three items we developed for this study. Using linear regression analyses we found that perceived stigma was associated with greater guilt, a greater feeling of escape from everyday life, and more negative condom attitudes among Latino clients. This was not found among non-Latino clients. Features of Latino culture, like machismo, and how they may relate to stigma of purchasing sex are discussed. PMID:23979714

  4. Acute effects of sex-specific sex hormones on heat shock proteins in fast muscle of male and female rats.

    PubMed

    Romani, William A; Russ, David W

    2013-10-01

    Heat shock protein (HSP) expression and sex hormone levels have been shown to influence several aspects of skeletal muscle physiology (e.g., hypertrophy, resistance to oxidative stress), suggesting that sex hormone levels can effect HSP expression. This study evaluated the effects of differing levels of sex-specific sex hormones (i.e., testosterone in males and estrogen in females) on the expression of 4: HSP70, HSC70, HSP25, and αB-crystallin in the quadriceps muscles of male and female rats. Animals were assigned to 1 of 3 groups (n = 5 M and F/group). The first group (Ctl) consisted of typically cage-housed animals that served as controls. The second group (H) was gonadectomized and received either testosterone (males) or estradiol (females) via injection for 12 consecutive days. The third group (Gx) was gonadectomized and injected as above, but with vehicle only, rather than hormones. Significant sex by condition interactions (P < 0.05 by two-way MANOVA) were found for all 4 proteins studied, except for HSP70, which exhibited a significant effect of condition only. The expression of all HSPs was greater (1.9-2.5-fold) in males vs. females in the Ctl group, except for HSP70, which was no different. Generally, gonadectomy appeared to have greater effects in males than females, but administration of the exogenous sex hormones tended to produce more robust relative changes in females than males. There were no differences in myosin composition in any of the groups, suggesting that changes in fiber type were not a factor in the differential protein expression. These data may have implications for sex-related differences in muscular responses to exercise, disuse, and injury. PMID:23821238

  5. “In different situations, in different ways”: Male sex work in St. Petersburg, Russia

    PubMed Central

    Niccolai, Linda M; King, Elizabeth J; Eritsyan, Ksenia; Safiullina, Liliya; Rusakova, Maia M

    2013-01-01

    We conducted a qualitative study of male sex work in St. Petersburg Russia with a focus on social vulnerabilities, HIV risk perception, and HIV-related behaviours. In-depth interviews were conducted with individuals knowledgeable about male sex work through their profession (n=8) and with male sex workers themselves (n=12). Male sex work involves a variety of exchanges including expensive vacations, negotiated monetary amounts, or simply access to food. Methods to find clients included the Internet, social venues (e.g. gay clubs and bars), and public places (e.g. parks). Use of the Internet greatly facilitated male sex work in a variety of ways. It was used by both individuals and agencies to find clients, and appeared to be increasing. Men often reported not being professionally connected to other male sex workers and limited disclosure about their work. Many were aware of the work-related risks to personal safety including violence and robbery by clients. Perceived risk for HIV was mostly abstract, and several exceptions to condom use with clients were noted. Alcohol use was reported as moderate but consumed frequently in association with work. These data suggest that the most salient risks for male sex workers include professional isolation, threats to personal safety, limited perceived HIV risk, and sub-optimal levels of condom use. PMID:23464743

  6. No Need to Discriminate? Reproductive Diploid Males in a Parasitoid with Complementary Sex Determination

    PubMed Central

    Elias, Jan; Mazzi, Dominique; Dorn, Silvia

    2009-01-01

    Diploid males in hymenopterans are generally either inviable or sterile, thus imposing a severe genetic load on populations. In species with the widespread single locus complementary sex determination (sl-CSD), sex depends on the genotype at one single locus with multiple alleles. Haploid (hemizygous) individuals are always males. Diploid individuals develop into females when heterozygous and into males when homozygous at the sex determining locus. Our comparison of the mating and reproductive success of haploid and diploid males revealed that diploid males of the braconid parasitoid Cotesia glomerata sire viable and fertile diploid daughters. Females mated to diploid males, however, produced fewer daughters than females mated to haploid males. Nevertheless, females did not discriminate against diploid males as mating partners. Diploid males initiated courtship display sooner than haploid males and were larger in body size. Although in most species so far examined diploid males were recognized as genetic dead ends, we present a second example of a species with sl-CSD and commonly occurring functionally reproductive diploid males. Our study suggests that functionally reproductive diploid males might not be as rare as hitherto assumed. We argue that the frequent occurrence of inbreeding in combination with imperfect behavioural adaptations towards its avoidance promote the evolution of diploid male fertility. PMID:19551142

  7. Age-graded risks for commercial sexual exploitation of male and female youth.

    PubMed

    Reid, Joan A; Piquero, Alex R

    2014-06-01

    Emerging evidence indicates male youth are affected by commercial sexual exploitation (CSE). However, most studies investigating risk markers influencing age of onset of CSE have focused on vulnerabilities of girls and women. Using a sample of 1,354 serious youthful offenders (of whom approximately 8% of males and females reported being paid for sex), the current study assessed whether risks associated with age of onset of CSE for girls and young women operated similarly in boys and young men. Findings showed that African American male youth were at heightened risk for CSE, while female youth of all races/ethnicities were at similar risk. For all youth, maternal substance use and earlier age of first sex were associated with early age of onset of CSE. For male youth, experiencing rape and substance use dependency were associated with early age of onset. Psychotic symptoms, likely experienced as social alienation, were associated with both early and late age of onset. For all youth, lower educational attainment was associated with CSE beginning in later adolescence or young adulthood. In addition, substance use dependency was linked to late age of onset for female youth. Implications of the study findings for theory development and application to CSE are noted. PMID:24366965

  8. Climatic influence on demographic parameters of a tropical seabird varies with age and sex.

    PubMed

    Oro, Daniel; Torres, Roxana; Rodríguez, Cristina; Drummond, Hugh

    2010-04-01

    In marine ecosystems climatic fluctuation and other physical variables greatly influence population dynamics, but differential effects of physical variables on the demographic parameters of the two sexes and different age classes are largely unexplored. We analyzed the effects of climate on the survival and recruitment of both sexes and several age classes of a long-lived tropical seabird, the Blue-footed Booby (Sula nebouxii), using long-term observations on marked individuals. Results demonstrated a complex interaction between yearly fluctuations in climate (both local and global indexes, during both winter and breeding season) and the sex and age of individuals. Youngest birds' survival and recruitment were commonly affected by local climate, whereas oldest birds' parameters tended to be constant and less influenced by environmental variables. These results confirm the theoretical prediction that sex- and age-related variation in life-history demographic traits is greater under poor environmental conditions, and they highlight the importance of including variability in fitness components in demographic and evolutionary models. Males and females showed similar variation in survival but different recruitment patterns, in relation to both age and the spatial scale of climatic influence (local or global). Results indicate different life-history tactics for each sex and different ages, with birds likely trying to maximize their fitness by responding to the environmental contingencies of each year. PMID:20462134

  9. Male Sex Roles in Magazine Advertising, 1959-1979.

    ERIC Educational Resources Information Center

    Skelly, Gerald U.; Lundstrom, William J.

    1981-01-01

    Advertising featuring men appears to be moving gradually toward a decrease in sex-role stereotyping, although the progress is obviously slow. Of the 660 advertisements examined, only 13 were in the category showing men performing nonstereotypic roles capably or acknowledging that the sexes are fully equal. (PD)

  10. Hazardous Drinking and HIV-risk-related Behaviour among Male Clients of Female Sex Workers in Tijuana, Mexico

    PubMed Central

    Goodman-Meza, David; Pitpitan, Eileen V.; Semple, Shirley J.; Wagner, Karla D.; Chavarin, Claudia V.; Strathdee, Steffanie A.; Patterson, Thomas L.

    2015-01-01

    Background and Objectives Male clients of female sex workers (FSWs) are at high risk for HIV. Whereas the HIV risks of alcohol use are well understood, less is known about hazardous alcohol use among male clients of FSWs, particularly in Mexico. We sought to identify risk factors for hazardous alcohol use and test associations between hazardous alcohol use and HIV risk behaviour among male clients in Tijuana. Method Male clients of FSWs in Tijuana (n = 400) completed a quantitative interview in 2008. The AUDIT was used to characterize hazardous alcohol use. Multivariate logistic regression was used to determine independent associations of demographic and HIV risk variables with hazardous alcohol use (vs. non-hazardous). Results Forty percent of our sample met criteria for hazardous alcohol use. Variables independently associated with hazardous drinking were reporting any sexually transmitted infection (STI), having sex with a FSW while under the influence of alcohol, being younger than 36 years of age, living in Tijuana, and ever having been jailed. Hazardous drinkers were less likely ever to have been deported or to have shared injection drugs. Discussion and Conclusions Hazardous alcohol use is associated with HIV risk, including engaging in sex with FSWs while intoxicated and having an STI among male clients of FSWs in Tijuana. Scientific Significance We systematically described patterns and correlates of hazardous alcohol use among male clients of FSWs in Tijuana, Mexico. The results suggest that HIV/STI risk reduction interventions must target hazardous alcohol users, and be tailored to address alcohol use. PMID:25066863

  11. Sex and age mortality responses in zinc acetate-treated mice

    SciTech Connect

    Hogan, G.R.; Cole, B.S.; Lovelace, J.M.

    1987-07-01

    In regard to trace metal treatment or exposure, a number of variables are known to affect the expression of toxicity concerning its time course and degree. For example, known variables are route of administration, anionic component of the test substance, and sex and age of the recipient animal. Concerning the latter, little, if any, data have been reported dealing with sex- and age-related responses to excess zinc in mammalian systems. The primary purpose of the short communication presented here focuses on the determination of median lethal dose in sexually immature, i.e., juvenile, and adult female and male mice following a single zinc acetate insult. In addition, variation of lethality responses was examined with the age and sex groups to a divided treatment of a lethal dosage of zinc acetate, the injections of which were separated by various intervals.

  12. Sex and Age Differences in Mortality in Southern China, 2004-2010.

    PubMed

    Yu, Leibin; Lin, Xinqin; Liu, Haiyan; Shi, Jian; Nong, Quanxing; Tang, Hongyang; Mao, Zongfu

    2015-07-01

    The purpose of this study was to describe the mortality patterns in the southern provinces of China, and to provide epidemiologic data on sex and age differences of death outcomes. Reliable mortality and population data from January 2004 to December 2010 were obtained from 12 Disease Surveillance Point (DSP) sites in four provinces of China. Death data from all causes and respiratory disease, chronic obstructive pulmonary disease (COPD), pneumonia and influenza, circulatory disease, and ischemic heart disease, were stratified by year, month of death occurrence and sex, seven age groups, and summarized by descriptive statistics. The mean annual mortality rates of the selected 12 DSP sites in the southernmost provinces of China were 543.9 (range: 423.9-593.6) deaths per 100,000 population. The death rates show that noted sex differences were higher in the male population for all-cause, COPD and circulatory diseases. Pneumonia and influenza death rates present a different sex- and age-related distribution, with higher rates in male aged 65-74 years; whereas the death rates were opposite in elderly aged ≥75 years, and relatively higher in young children. This study had practical implications for recommending target groups for public health interventions. PMID:26184261

  13. Sex and Age Differences in Mortality in Southern China, 2004–2010

    PubMed Central

    Yu, Leibin; Lin, Xinqin; Liu, Haiyan; Shi, Jian; Nong, Quanxing; Tang, Hongyang; Mao, Zongfu

    2015-01-01

    The purpose of this study was to describe the mortality patterns in the southern provinces of China, and to provide epidemiologic data on sex and age differences of death outcomes. Reliable mortality and population data from January 2004 to December 2010 were obtained from 12 Disease Surveillance Point (DSP) sites in four provinces of China. Death data from all causes and respiratory disease, chronic obstructive pulmonary disease (COPD), pneumonia and influenza, circulatory disease, and ischemic heart disease, were stratified by year, month of death occurrence and sex, seven age groups, and summarized by descriptive statistics. The mean annual mortality rates of the selected 12 DSP sites in the southernmost provinces of China were 543.9 (range: 423.9–593.6) deaths per 100,000 population. The death rates show that noted sex differences were higher in the male population for all-cause, COPD and circulatory diseases. Pneumonia and influenza death rates present a different sex- and age-related distribution, with higher rates in male aged 65–74 years; whereas the death rates were opposite in elderly aged ≥75 years, and relatively higher in young children. This study had practical implications for recommending target groups for public health interventions. PMID:26184261

  14. Fundamental frequency perturbation indicates perceived health and age in male and female speakers

    NASA Astrophysics Data System (ADS)

    Feinberg, David R.

    2001-05-01

    There is strong support for the idea that healthy vocal chords are able to produce fundamental frequencies (F0) with minimal perturbation. Measures of F0 perturbation have been shown to discriminate pathological versus healthy populations. In addition to measuring vocal chord health, F0 perturbation is a correlate of real and perceived age. Here, the role of jitter (periodic variation in F0) and shimmer (periodic variation in amplitude of F0) in perceived health and age in a young adult (males aged 18-33, females aged 18-26), nondysphonic population was investigated. Voices were assessed for health and age by peer aged, opposite-sex raters. Jitter and shimmer were measured with Praat software (www.praat.org) using various algorithms (jitter: DDP, local, local absolute, PPQ5, and RAP; shimmer: DDA, local, local absolute, APQ3, APQ5, APQ11) to reduce measurement error, and to ascertain the robustness of the findings. Male and female voices were analyzed separately. In both sexes, ratings of health and age were significantly correlated. Measures of jitter and shimmer correlated negatively with perceived health, and positively with perceived age. Further analysis revealed that these effects were independent in male voices. Implications of this finding are that attributions of vocal health and age may reflect actual underlying condition.

  15. Sex-specific plasticity and genotype × sex interactions for age and size of maturity in the sheepshead swordtail, Xiphophorus birchmanni.

    PubMed

    Boulton, K; Rosenthal, G G; Grimmer, A J; Walling, C A; Wilson, A J

    2016-03-01

    Responses to sexually antagonistic selection are thought to be constrained by the shared genetic architecture of homologous male and female traits. Accordingly, adaptive sexual dimorphism depends on mechanisms such as genotype-by-sex interaction (G×S) and sex-specific plasticity to alleviate this constraint. We tested these mechanisms in a population of Xiphophorus birchmanni (sheepshead swordtail), where the intensity of male competition is expected to mediate intersexual conflict over age and size at maturity. Combining quantitative genetics with density manipulations and analysis of sex ratio variation, we confirm that maturation traits are dimorphic and heritable, but also subject to large G×S. Although cross-sex genetic correlations are close to zero, suggesting sex-linked genes with important effects on growth and maturation are likely segregating in this population, we found less evidence of sex-specific adaptive plasticity. At high density, there was a weak trend towards later and smaller maturation in both sexes. Effects of sex ratio were stronger and putatively adaptive in males but not in females. Males delay maturation in the presence of mature rivals, resulting in larger adult size with subsequent benefit to competitive ability. However, females also delay maturation in male-biased groups, incurring a loss of reproductive lifespan without apparent benefit. Thus, in highly competitive environments, female fitness may be limited by the lack of sex-specific plasticity. More generally, assuming that selection does act antagonistically on male and female maturation traits in the wild, our results demonstrate that genetic architecture of homologous traits can ease a major constraint on the evolution of adaptive dimorphism. PMID:26688295

  16. Sexual hazards, life experiences and social circumstances among male sex workers in Nigeria.

    PubMed

    Okanlawon, Kehinde; Adebowale, Ayo Stephen; Titilayo, Ayotunde

    2013-01-01

    The sexual health and rights needs of male sex workers in Nigeria remain poorly understood and served. Men who sell sex are at high risk of discrimination and violation because of laws criminalising same-sex activity and sex work. This paper examines the experiences, social circumstances, vulnerabilities and sexual hazards experienced by male sex workers in Nigeria. In-depth interviews were used to explore the experiences of six male sex workers who were selected by means of convenience sampling from among those who came for counselling. Findings reveal that economic disadvantage drives some men to engage in sex work and risky sexual behaviour. Subsequently, sex work may put their lives and health at risk as a result of violation by the police and clients, including ritual murder. Men's extreme vulnerability points to the need for appropriate interventions to improve well-being. Sexual health and rights programmes must identify ways of making male sex workers less vulnerable to abuse, and devise strategies for protecting their health and human rights, while empowering them economically to reduce their dependency on often risky sexual behaviour for livelihoods. PMID:23252939

  17. Sex difference in pathology of the ageing gut mediates the greater response of female lifespan to dietary restriction.

    PubMed

    Regan, Jennifer C; Khericha, Mobina; Dobson, Adam J; Bolukbasi, Ekin; Rattanavirotkul, Nattaphong; Partridge, Linda

    2016-01-01

    Women live on average longer than men but have greater levels of late-life morbidity. We have uncovered a substantial sex difference in the pathology of the aging gut in Drosophila. The intestinal epithelium of the aging female undergoes major deterioration, driven by intestinal stem cell (ISC) division, while lower ISC activity in males associates with delay or absence of pathology, and better barrier function, even at old ages. Males succumb to intestinal challenges to which females are resistant, associated with fewer proliferating ISCs, suggesting a trade-off between highly active repair mechanisms and late-life pathology in females. Dietary restriction reduces gut pathology in aging females, and extends female lifespan more than male. By genetic sex reversal of a specific gut region, we induced female-like aging pathologies in males, associated with decreased lifespan, but also with a greater increase in longevity in response to dietary restriction. PMID:26878754

  18. The Role of Clitoral Anatomy in Female to Male Sex Reassignment Surgery

    PubMed Central

    2014-01-01

    Introduction. Controversies on clitoral anatomy and its role in female sexual function still make clitoral reconstructive surgery very challenging. We evaluated the role of clitoral anatomic features in female to male sex reassignment surgery. Material and Methods. The study included 97 female transsexuals, aged from 18 to 41 years, who underwent single stage metoidioplasty between March 2008 and January 2013. The operative technique involved vaginectomy, the release of clitoral ligaments and urethral plate, urethroplasty by combining buccal mucosa graft and genital flaps, and scrotoplasty with insertion of testicle prostheses. Postoperative questionnaire was used to evaluate aesthetic, functional, and sexual outcome. Results. The mean followup was 30 months. The mean length of the neophallus was 7 cm, compared to mean preoperative length of the hypertrophied clitoris of 3.3 cm. Complications occurred in 27.84% of all patients, related mostly to urethroplasty. Voiding while standing was achieved in all cases. None of the patients had problems in sexual arousal, masturbation, or orgasms. Conclusion. Accurate knowledge of the clitoral anatomy, physiology, and neurovascular supply is crucial for a successful outcome of female to male sex reassignment surgery. Our approach appears to ensure overall satisfaction and high quality of sexual life. PMID:24982953

  19. Markers of sexually transmitted diseases in seminal fluid of male clients of female sex workers.

    PubMed Central

    Worm, A M; Lauritzen, E; Jensen, I P; Jensen, J S; Christiansen, C B

    1997-01-01

    OBJECTIVES: To screen for certain STD markers in a group of male clients of female sex workers. METHOD: Condoms with seminal fluid were collected at 10 "massage parlours" in Copenhagen. The seminal fluid samples were examined for HIV antibodies, markers of hepatitis B virus (HBV), Chlamydia trachomatis, and Mycoplasma genitalium. RESULTS: All samples (n = 332) were negative for HIV antibodies. Out of 327 samples examined for HBV markers 32 (9.8%) were positive for HBV core antibodies, one of which was also positive for HBV antigen. C trachomatis could be demonstrated in six out of 122 (4.9%) samples and M genitalium in one out of 122 samples. CONCLUSIONS: The finding of a C trachomatis prevalence of 4.9% is considerable higher than expected in men with a presumed age of 35-55 years. The demonstration of a prevalence of HBV markers of 9.8% indicates that these clients have an increased risk of HBV infection, a finding that further consolidates the recommendation of HBV vaccination of sex workers. As shown in this study, STD transmission in commercial sex may also have the client as the source. PMID:9389951

  20. Sex recognition and mate choice by male western toads, Bufo boreas.

    PubMed

    Marco; Kiesecker; Chivers; Blaustein

    1998-06-01

    In field-based choice experiments, we examined sex recognition and mate choice in male western toads, Bufo boreas. When given a simultaneous choice between a male and a female of equal size, males did not discriminate between the sexes and attempted to amplex a male or a female with equal frequency. When a test male clasped a stimulus male, the stimulus male uttered a release call that caused the test male to release the stimulus male. Male-male amplexus never lasted more than 3 s, but male-female amplexus was tenacious and prolonged. Furthermore, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones, but they did not discriminate between gravid females or non-gravid females of equal size. In choice tests that excluded chemical cues, males jumped more frequently towards large females than small ones. Given that females are significantly larger than males, selecting larger individuals as potential mates increases the probability that males amplex with a female. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9642006

  1. Age- and sex-related variations in vocal-tract morphology and voice acoustics during adolescence.

    PubMed

    Markova, Diana; Richer, Louis; Pangelinan, Melissa; Schwartz, Deborah H; Leonard, Gabriel; Perron, Michel; Pike, G Bruce; Veillette, Suzanne; Chakravarty, M Mallar; Pausova, Zdenka; Paus, Tomáš

    2016-05-01

    Distinct differences in the human voice emerge during adolescence, with males producing deeper and more resonant voices than females by the end of sexual maturation. Using magnetic resonance images of heads and voice recordings obtained in 532 typically developing adolescents, we investigate what might be the drivers of this change in voice, and the subjective judgment of the voice "maleness" and "femaleness". We show clear sex differences in the morphology of voice-related structures during adolescence, with males displaying strong associations between age (and puberty) and both vocal-fold and vocal-tract length; this was not the case in female adolescents. At the same time, males (compared with females) display stronger associations between age (and puberty) with both fundamental frequency and formant position. In males, vocal morphology was a mediator in the relationship between bioavailable testosterone and acoustic indices. Subjective judgment of the voice sex could be predicted by the morphological and acoustic parameters in males only: the length of vocal folds and its acoustic counterpart, fundamental frequency, is a larger predictor of subjective "maleness" of a voice than vocal-tract length and formant position. PMID:27062936

  2. The influence of averageness on judgments of facial attractiveness: no own-age or own-sex advantage among children attending single-sex schools.

    PubMed

    Vingilis-Jaremko, Larissa; Maurer, Daphne; Gao, Xiaoqing

    2014-04-01

    We examined how recent biased face experience affects the influence of averageness on judgments of facial attractiveness among 8- and 9-year-old children attending a girls' school, a boys' school, and a mixed-sex school. We presented pairs of individual faces in which one face was transformed 50% toward its group average, whereas the other face was transformed 50% away from that average. Across blocks, the faces varied in age (adult, 9-year-old, or 5-year-old) and sex (male or female). We expected that averageness might influence attractiveness judgments more strongly for same-age faces and, for children attending single-sex schools, same-sex faces of that age because their prototype(s) should be best tuned to the faces they see most frequently. Averageness influenced children's judgments of attractiveness, but the strength of the influence was not modulated by the age of the face, nor did the effects of sex of face differ across schools. Recent biased experience might not have affected the results because of similarities between the average faces of different ages and sexes and/or because a minimum level of experience with a particular group of faces may be adequate for the formation of a veridical prototype and its influence on judgments of attractiveness. The results suggest that averageness affects children's judgments of the attractiveness of the faces they encounter in everyday life regardless of age or sex of face. PMID:24326246

  3. Sex-related differences and age of peak performance in breaststroke versus freestyle swimming

    PubMed Central

    2013-01-01

    Background Sex-related differences in performance and in age of peak performance have been reported for freestyle swimming. However, little is known about the sex-related differences in other swimming styles. The aim of the present study was to compare performance and age of peak performance for elite men and women swimmers in breaststroke versus freestyle. Methods Race results were analyzed for swimmers at national ranked in the Swiss high score list (during 2006 through 2010) and for international swimmers who qualified for the finals of the FINA World Swimming Championships (during 2003 through 2011). Results The sex-related difference in swimming speed was significantly greater for freestyle than for breaststroke over 50 m, 100 m, and 200 m race distances for Swiss swimmers, but not for FINA finalists. The sex-related difference for both freestyle and breaststroke swimming speeds decreased significantly with increasing swimming distance for both groups. Race distance did not affect the age of peak performance by women in breaststroke, but age of peak performance was four years older for FINA women than for Swiss women. Men achieved peak swimming performance in breaststroke at younger ages for longer race distances, and the age of peak swimming performance was six years older for FINA men than for Swiss men. In freestyle swimming, race distance did not affect the age of peak swimming performance for Swiss women, but the age of peak swimming performance decreased with increasing race distance for Swiss men and for both sexes at the FINA World Championships. Conclusions Results of the present study indicate that (i) sex-related differences in swimming speed were greater for freestyle than for breaststroke for swimmers at national level, but not for swimmers at international level, and (ii) both female and male swimmers achieved peak swimming speeds at younger ages in breaststroke than in freestyle. Further studies are required to better understand differences

  4. Naked at Our Age: Talking out Loud about Senior Sex

    ERIC Educational Resources Information Center

    Davis, Melanie

    2012-01-01

    "Naked at Our Age" is an excellent resource for sexually interested and/or active adults over the age of 60. The book combines the author's personal reflections, questions and stories shared by older adults, and advice from sex therapists, sexuality educators, the author, and health care providers. The breadth of topics makes the book useful to…

  5. Sex- and Gonad-Affecting Scent Compounds and 3 Male Pheromones in the Rat

    PubMed Central

    Sun, Lixing; Zhang, Jin-Hua; Feng, Zhi-Yong

    2008-01-01

    This study was aimed at identifying sex pheromones of the rat (Rattus norvegicus). We characterized the volatiles and semivolatiles of rat preputial gland and voided urine by using gas chromatography–mass spectrometry (GC–MS) and quantified them by their GC areas (abundances) and percentage of GC areas (relative abundances). Although all the compounds other than 4-heptanone and phenol detected were shared by males and females, the quantities for some of these sex-common compounds exhibited sexual dimorphism and decreased with gonadectomy. Thus, these compounds might be sex pheromones. Among them, squalene from preputial glands and 2-heptanone and 4-ethyl phenol from urine were 3 major compounds. They were richer in males and could be suppressed by castration. Adding any of the 3 compounds (at a concentration higher than its physiological level in male urine) to castrated male urine (CMU) increased the attractiveness of CMU to sex-naive females. Adding the 3 together (at the levels in normal male urine) to CMU significantly increased the attractiveness of CMU to females. However, such combination did not fully restore females' preference for urine from intact males, suggesting that some other trace compounds such as 4-heptanone and phenol might also play some roles in sex attractiveness. Thus, squalene, 2-heptanone, and 4-ethyl phenol were indeed male pheromone molecules in rats. Our study also indicates that E,E-β-farnesene and E-α-farnesene, both richer in females than males, might be putative female pheromones. PMID:18515819

  6. Sex- and gonad-affecting scent compounds and 3 male pheromones in the rat.

    PubMed

    Zhang, Jian-Xu; Sun, Lixing; Zhang, Jin-Hua; Feng, Zhi-Yong

    2008-09-01

    This study was aimed at identifying sex pheromones of the rat (Rattus norvegicus). We characterized the volatiles and semivolatiles of rat preputial gland and voided urine by using gas chromatography-mass spectrometry (GC-MS) and quantified them by their GC areas (abundances) and percentage of GC areas (relative abundances). Although all the compounds other than 4-heptanone and phenol detected were shared by males and females, the quantities for some of these sex-common compounds exhibited sexual dimorphism and decreased with gonadectomy. Thus, these compounds might be sex pheromones. Among them, squalene from preputial glands and 2-heptanone and 4-ethyl phenol from urine were 3 major compounds. They were richer in males and could be suppressed by castration. Adding any of the 3 compounds (at a concentration higher than its physiological level in male urine) to castrated male urine (CMU) increased the attractiveness of CMU to sex-naive females. Adding the 3 together (at the levels in normal male urine) to CMU significantly increased the attractiveness of CMU to females. However, such combination did not fully restore females' preference for urine from intact males, suggesting that some other trace compounds such as 4-heptanone and phenol might also play some roles in sex attractiveness. Thus, squalene, 2-heptanone, and 4-ethyl phenol were indeed male pheromone molecules in rats. Our study also indicates that E,E-beta-farnesene and E-alpha-farnesene, both richer in females than males, might be putative female pheromones. PMID:18515819

  7. Core groups and the transmission of HIV: learning from male sex workers.

    PubMed

    Parker, Melissa

    2006-01-01

    A growing and substantial body of research suggests that female sex workers play a disproportionately large role in the transmission of HIV in many parts of the world, and they are often referred to as core groups by epidemiologists, mathematical modellers, clinicians and policymakers. Male sex workers, by contrast, have received little attention and it is not known whether it is helpful to conceptualize them as a core group. This paper draws upon ethnographic research documenting social and sexual networks in London and looks at the position of five male sex workers within a network comprising 193 men and seven women (as well as 1378 anonymous sexual contacts and 780 commercial contacts). In so doing, it suggests that there is no evidence to show that male sex workers are more or less likely to acquire or transmit HIV in the course of commercial sex compared with other types of sexual relationships. In addition, men engaging in non-commercial sex all reported having unprotected sex in a variety of contexts and relationships and there is no evidence to suggest that men who are not sex workers play less of a role in the transmission of HIV. In short, these data suggest that it would be inappropriate to conceptualize male sex workers as a core group. This is not to suggest that public policy should continue to overlook male sex workers. New and inventive approaches are required to reach out to a vulnerable but diverse group of men, selling sex for a variety of reasons; even if these men are no more vulnerable to acquiring and/or transmitting HIV than other men and women that form part of their network. PMID:16321168

  8. Histological and sex steroid hormone receptor changes in testes of immature, mature, and aged chickens.

    PubMed

    González-Morán, María Genoveva; Guerra-Araiza, Christian; Campos, María G; Camacho-Arroyo, Ignacio

    2008-11-01

    Sex steroid hormone receptors play a central role in the regulation of reproduction in male chickens. In this work, we evaluated by histomorphometric methods and Western blot analysis changes in the number of the different cell populations and in the content of sex steroid hormone receptors in testes from immature (1.5-month-old), mature (12-month-old), and aged (48-month-old) chickens. The number of Sertoli cells, germ cells, and Leydig cells per area of testicular tissue markedly changed according to chicken age. The highest number of Sertoli and Leydig cells was found in testes of immature chickens, with a dramatic decrease in those of mature chickens; however, the number of germ cells was the highest in mature chickens in comparison with other ages. The content of androgen receptor diminished in testes of mature and aged animals in comparison with that of immature chickens. In contrast, the content of estrogen receptor alpha and progesterone receptor was higher in testes of mature animals than in other ages. Both progesterone receptor isoforms were expressed in a similar proportion in testes of immature and mature animals. Interestingly, progesterone receptor isoform A was the predominant isoform in aged animals. These results suggest that there are marked age-dependent changes in chicken testes histology and in sex steroid hormone receptors content that should contribute to sex steroid hormone actions, in this tissue throughout the lifespan of chickens. PMID:18815005

  9. Sex ratio and spatial distribution of male and female Antennaria dioica (Asteraceae) plants

    NASA Astrophysics Data System (ADS)

    Varga, Sandra; Kytöviita, Minna-Maarit

    2011-09-01

    Sex ratio, sex spatial distribution and sexual dimorphism in reproduction and arbuscular mycorrhizal colonisation were investigated in the dioecious clonal plant Antennaria dioica (Asteraceae). Plants were monitored for five consecutive years in six study plots in Oulanka, northern Finland. Sex ratio, spatial distribution of sexes, flowering frequency, number of floral shoots and the number and weight of inflorescences were recorded. In addition, intensity of mycorrhizal fungi in the roots was assessed. Both sexes flowered each year with a similar frequency, but the overall genet sex ratio was strongly female-biased. The bivariate Ripley's analysis of the sex distribution showed that within most plots sexes were randomly distributed except for one plot. Sexual dimorphism was expressed as larger floral and inflorescence production and heavier inflorescences in males. In addition, the roots of both sexes were colonised to a similar extent by arbuscular mycorrhizal fungi. The female sex-biased flowering ratios reported are not consistent among years and cannot be explained in terms of spatial segregation of the sexes or sex lability. The possible reasons for the female-biased sex ratio are discussed.

  10. HIV Risk and Social Networks Among Male-to-Female Transgender Sex Workers in Boston, Massachusetts

    PubMed Central

    Reisner, Sari L.; Mimiaga, Matthew J.; Bland, Sean; Mayer, Kenneth H.; Perkovich, Brandon; Safren, Steven A.

    2013-01-01

    Male-to-female transgender individuals who engage in sex work constitute a group at high risk for HIV infection in the United States. This mixed-methods formative study examined sexual risk among preoperative transgender male-to-female sex workers (N = 11) in Boston. More than one third of the participants were HIV-infected and reported a history of sexually transmitted diseases. Participants had a mean of 36 (SD = 72) transactional male sex partners in the past 12 months, and a majority reported at least one episode of unprotected anal sex. Qualitative themes included (a) sexual risk, (b) motivations for engaging in sex work, (c) consequences of sex work, (d) social networks (i.e., “trans mothers,” who played a pivotal role in initiation into sex work), and (e) potential intervention strategies. Results suggest that interventions with transgender male-to-female sex workers must be at multiple levels and address the psychosocial and environmental contexts in which sexual risk behavior occurs. PMID:19732696

  11. A Prospective Analysis of Juvenile Male Sex Offenders: Characteristics and Recidivism Rates as Adults

    ERIC Educational Resources Information Center

    Vandiver, Donna M.

    2006-01-01

    This research assesses the recidivism rates of a sample of 300 registered male sex offenders who were juveniles at the time of their initial arrest for a sex offense. This sample is followed for 3 to 6 years after they reached adulthood; recidivism rates are assessed during their adulthood only. The typical juvenile is a 15-year-old Caucasian male…

  12. Age at reproductive maturity and effect of age and time of day on sex sttraction in the potato psyllid Bactericera cockerelli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potato psyllid, Bactericera (= Paratrioza) cockerelli (Šulc) (Hemiptera: Triozidae), is a major pest of potato. Studies were conducted to determine the age at which both males and females reach reproductive maturity and the effect of age and time of day on sex attraction. Adult B. cockerelli r...

  13. Prevalence and correlates of sexual risk among male and female sex workers in Tijuana, Mexico.

    PubMed

    Katsulis, Yasmina; Durfee, Alesha

    2012-01-01

    We investigated prevalence and correlates of sexual risk behaviours among male and female sex workers in Tijuana, Mexico, the busiest border crossing area on the US - Mexico border, analysing survey data from a purposive, cross-sectional sample of male and female sex workers who worked in a range of indoor and outdoor settings. Logistic regression was used to determine factors that were associated with sexual risk-taking, defined as failing to use a condom with last client. In bivariate regression models, gender, work setting (e.g., indoor vs. outdoor), poverty, engaging in survival sex, marital status and perceived drug addiction were correlated with sexual risk. When controlling for work location, housing insecurity, poverty, survival sex, marital status and perceived drug addiction, male sex workers were still 10 times more likely than female sex workers (FSW) to engage in sex without a condom during their last encounter with a client. And, although FSW were significantly more likely than males to have used a condom with a client, they were significantly less likely than males to have used a condom with their regular partner. Future research should further examine how gender shapes sexual risk activities in both commercial and non-commercial relationships. PMID:22304493

  14. Identification of a sex pheromone from male yellow mealworm beetles, Tenebrio molitor.

    PubMed

    Bryning, Gareth P; Chambers, John; Wakefield, Maureen E

    2005-11-01

    The sex pheromone released by the adult female Tenebrio molitor, 4-methyl-1-nonanol, is well known. In addition, there is evidence that adult males release a pheromone that attracts females. The purpose of the present study was to isolate and identify male-released pheromone(s). Emissions from virgin adult males and females were collected on filter paper and extracted with pentane. Extracts were analyzed by gas chromatography-mass spectrometry. One male-specific compound was detected and identified as (Z)-3-dodecenyl acetate (Z3-12:Ac). In arena bioassays, E3-12:Ac was attractive to females only, at 1 and 10 microg doses. E3-12:Ac was also attractive to females at a 10-microg dose. The presence of both male and female pheromones, each attracting the opposite sex, may contribute to maintaining a high-density population of both sexes. PMID:16273437

  15. Aging changes in the male reproductive system

    MedlinePlus

    ... a scarlike tissue. This condition, called benign prostatic hypertrophy (BPH), affects about 50% of men. BPH may ... Many physical age-related changes, such as prostate enlargement or testicular atrophy, are not preventable. Getting treated ...

  16. Effects of age and sex on the structural, chemical and technological characteristics of mule duck meat.

    PubMed

    Baeza, E; Salichon, M R; Marche, G; Wacrenier, N; Dominguez, B; Culioli, J

    2000-07-01

    1. The aim of the study was to analyse the effect of age and sex on the chemical, structural and technological characteristics of mule duck meat. 2. Ten males and 10 females were weighed and slaughtered at 8, 10, 11, 12 and 13 weeks of age. Weight, pH value, colour, tenderness and juice loss of breast muscle were determined. 3. The activities of 3 enzymes (citrate synthase, beta-hydroxyacyl CoA dehydrogenase, lactate dehydrogenase) which indicate muscular metabolic activity were assayed. 4. Chemical composition (moisture, lipids, proteins, minerals, lipid and phospholipid classes, fatty acid composition) of breast muscle was analysed. 5. Fibre type, fibre type percentage and cross-sectional areas were determined using histochemistry and an image analysis system. 6. For growth performance and muscular structure, the ideal slaughter age of mule ducks is 10 weeks of age. Chemical and technological analysis indicated that muscular maturity in Pectoralis major was reached at 11 weeks of age, but, at this age, breast lipid content is high. Moreover, after 10 weeks of age, food costs rapidly increased. 7. Lastly, sexual dimorphism for body weight is minor. In this study, at any given age, no significant differences between males and females were shown. Thus, it is possible to rear both sexes together and to slaughter them at the same age. PMID:11081424

  17. Adolescent and young adult male sex offenders: understanding the role of recidivism.

    PubMed

    Riser, Diana K; Pegram, Sheri E; Farley, Julee P

    2013-01-01

    The current review explores the complex paths that can lead to adolescent and young adult males becoming sexually abusive. Because sexual abuse is an ongoing issue in our society that is often oversimplified, this article distinguishes between the various risk factors that predict sexually abusive behavior and types of sex offenders, particularly recidivistic offenders. It is imperative to focus on adolescents and young adults who sexually abuse because they represent a particularly important intervention point in preventing sexual abuse in comparison to older age groups and address the importance of differentiating among youths who sexually abuse, particularly between one-time offenders and recidivistic offenders. Implications for addressing these differences are discussed. PMID:23350537

  18. Sex chromosome loss and aging: In situ hybridization studies on human interphase nuclei

    SciTech Connect

    Guttenbach, M.; Koschorz, B.; Bernthaler, U.

    1995-11-01

    A total of 1,000 lymphocyte interphase nuclei per proband from 90 females and 138 males age 1 wk to 93 years were analyzed by in situ hybridization for loss of the X and Y chromosomes, respectively. Both sex chromosomes showed an age-dependent loss. In males, Y hypoploidy was very low up to age 15 years (0.05%) but continuously increased to a frequency of 1.34% in men age 76-80 years. In females, the baseline level for X chromosome loss is much higher than that seen for the Y chromosome in males. Even prepubertal females show a rate of X chromosome loss on the order of 1.5%-2.5%, rising to {approximately}4.5%-5% in women older than 75 years. Dividing the female probands into three biological age groups on the basis of sex hormone function (<13 years, 13-51 years, and >51 years), a significant correlation of X chromosome loss versus age could clearly be demonstrated in women beyond age 51 years. Females age 51-91 years showed monosomy X at a rate from 3.2% to 5.1%. In contrast to sex chromosomal loss, the frequency of autosomal monosomies does not change during the course of aging: chromosome 1 and chromosome 17 monosomic cells were found with a constant incidence of 1.2% and 1%, respectively. These data also indicate that autosome loss in interphase nuclei is not a function of chromosome size. 34 refs., 5 figs., 6 tabs.

  19. Stroke sensitivity in the aged: sex chromosome complement vs. gonadal hormones

    PubMed Central

    McCullough, Louise D.; Mirza, Mehwish A.; Xu, Yan; Bentivegna, Kathryn; Steffens, Eleanor B.; Ritzel, Rodney; Liu, Fudong

    2016-01-01

    Stroke is a sexually dimorphic disease. Elderly women not only have higher stroke incidence than age-matched men, but also have poorer recovery and higher morbidity and mortality after stroke. In older, post-menopausal women, gonadal hormone levels are similar to that of men. This suggests that tissue damage and functional outcomes are influenced by biologic sex (XX vs. XY) rather than the hormonal milieu at older ages. We employed the Four Core Genotype (FCG) mouse model to study the contribution of sex chromosome complement and gonadal hormones to stroke sensitivity in aged mice in which the testis determining gene (Sry) is removed from the Y chromosome, allowing for the generation of XX males and XY females. XXF, XXM, XYF, XYM and XYwt aged mice were subjected to middle cerebral artery occlusion (MCAO). XXF and XXM mice had significantly larger infarct volumes than XYF and XYM cohorts respectively. There was no significant difference in hormone levels among aged FCG mice. XXF/XXM mice also had more robust microglial activation and higher serum levels of pro-inflammatory cytokines than XYF/XYM cohort respectively. We concluded that the sex chromosome complement contributes to ischemic sensitivity in aged animals and leads to sex differences in innate immune responses. PMID:27405096

  20. Women's motivations to have sex in casual and committed relationships with male and female partners.

    PubMed

    Armstrong, Heather L; Reissing, Elke D

    2015-05-01

    Women report a wide variety of reasons to have sex (e.g., Meston & Buss, 2010), and while it is reasonable to assume that those reasons may vary based on the context of the relationship, this assumption has not yet been tested. The purpose of this study was to explore how relationship type, sexual attraction, and the gender of one's partner interact and affect the sexual motivations of women. A total of 510 women (361 who reported exclusively other-sex attraction and 149 who reported same-sex/bisexual attraction) completed the YSEX? questionnaire. Participants rated their sexual motivations for casual sex and sex in a committed relationship with male and/or female partners, depending on reported sexual attraction. Results showed that relationship type affected reported motivation for sex: physical motivations were more strongly endorsed for casual sex, whereas emotional motivations were more strongly endorsed for sex in committed relationships. No significant differences in motivation were reported between women who reported same-sex attraction and those who did not. Women who reported bisexual attraction and identified as being lesbian, bisexual, or another sexual minority reported no significant differences in motivation for sex with male or female partners. The results of this study highlight the importance of relationship context when discussing sexual motivation and suggest a high degree of similarity in motivation for women, regardless of sexual orientation or gender of partner. PMID:25567073

  1. Differences in Gay Male Couples' Use of Drugs and Alcohol With Sex by Relationship HIV Status.

    PubMed

    Mitchell, Jason W

    2016-07-01

    Prior studies with men who have sex with men have documented a strong association between substance use with sex and risk for acquisition of HIV. However, few studies have been conducted about gay male couples' use of substances with sex, despite the fact that between one third and two thirds of men who have sex with men acquire HIV from their relationship partners. The present study sought to (1) describe whether one or both partners in the male couple uses substances with sex-by substance type-within and/or outside of their relationship, and (2) assess whether differences exist in those who use substances with sex within and outside the relationship by the couples' HIV status. Dyadic data for this analysis were collected in the United States from a nation-wide cross-sectional Internet study about male couples' relationships and behaviors. Couple-level descriptive and comparative analyses were employed with 361 male couples. Except for alcohol, most couples did not use substances with sex. Of those who did, rates of who used it with sex and substance type within the relationship varied; most couples only had one partner who used substances with sex outside the relationship. Significantly higher proportions of concordantly HIV-negative and HIV-positive couples had both partners who used substances (all types) with sex within their relationship over discordant couples. Most couples had one partner who used outside the relationship; only marijuana and erectile dysfunction medication use with sex significantly differed by couples' HIV status. Findings indicate the need to conduct additional research for prevention development. PMID:25424504

  2. Age at death estimation from bone histology in Malaysian males.

    PubMed

    Nor, Faridah Mohd; Pastor, Robert F; Schutkowski, Holger

    2014-10-01

    Estimation of age from microscopic examination of human bone utilizes bone remodeling. This allows 2 regression equation to be determined in a specific population based on the variation in osteon turnover in different populations. The aim of this study was to provide age estimation for Malaysian males. Ground undecalcified cross sections were prepared from long limb bones of 50 deceased males aged between 21 and 78 years. Ten microstructural parameters were measured and subjected to multivariate regression analysis. Results showed that osteon count had the highest correlation with age (R = 0.43), and age was estimated to be within 10.94 years of the true value in 98% of males. Cross validation of the equation on 50 individuals showed close correspondence of true ages with estimated ages. Further studies are needed to validate and expand these results. PMID:24189643

  3. The sperm of aging male bustards retards their offspring's development.

    PubMed

    Preston, Brian T; Saint Jalme, Michel; Hingrat, Yves; Lacroix, Frederic; Sorci, Gabriele

    2015-01-01

    Understanding whether the sperm of older males has a diminished capacity to produce successful offspring is a key challenge in evolutionary biology. We investigate this issue using 10 years of reproductive data on captive long-lived houbara bustards (Chlamydotis undulata), where the use of artificial insemination techniques means parents can only influence offspring quality via their gametes. Here we show that paternal aging reduces both the likelihood that eggs hatch and the rate at which chicks grow, with older males producing the lightest offspring after the first month. Surprisingly, this cost of paternal aging on offspring development is of a similar scale to that associated with maternal aging. Fitting with predictions on germline aging, the sperm of immature males produce the fastest growing offspring. Our findings thus indicate that any good genes benefit that might be offered by older 'proven' males will be eroded by aging of their germline DNA. PMID:25647605

  4. The sperm of aging male bustards retards their offspring's development

    PubMed Central

    Preston, Brian T.; Saint Jalme, Michel; Hingrat, Yves; Lacroix, Frederic; Sorci, Gabriele

    2015-01-01

    Understanding whether the sperm of older males has a diminished capacity to produce successful offspring is a key challenge in evolutionary biology. We investigate this issue using 10 years of reproductive data on captive long-lived houbara bustards (Chlamydotis undulata), where the use of artificial insemination techniques means parents can only influence offspring quality via their gametes. Here we show that paternal aging reduces both the likelihood that eggs hatch and the rate at which chicks grow, with older males producing the lightest offspring after the first month. Surprisingly, this cost of paternal aging on offspring development is of a similar scale to that associated with maternal aging. Fitting with predictions on germline aging, the sperm of immature males produce the fastest growing offspring. Our findings thus indicate that any good genes benefit that might be offered by older ‘proven' males will be eroded by aging of their germline DNA. PMID:25647605

  5. No Sex or Age Difference in Dead-Reckoning Ability among Tsimane Forager-Horticulturalists.

    PubMed

    Trumble, Benjamin C; Gaulin, Steven J C; Dunbar, Matt D; Kaplan, Hillard; Gurven, Michael

    2016-03-01

    Sex differences in reproductive strategy and the sexual division of labor resulted in selection for and maintenance of sexual dimorphism across a wide range of characteristics, including body size, hormonal physiology, behavior, and perhaps spatial abilities. In laboratory tasks among undergraduates there is a general male advantage for navigational and mental-rotation tasks, whereas studies find female advantage for remembering item locations in complex arrays and the locations of plant foods. Adaptive explanations of sex differences in these spatial abilities have focused on patterns of differential mate search and routine participation in distinct subsistence behaviors. The few studies to date of spatial ability in nonindustrial populations practicing subsistence lifestyles, or across a wider age range, find inconsistent results. Here we examine sex- and age-based variation in one kind of spatial ability related to navigation, dead-reckoning, among Tsimane forager horticulturalists living in lowland Bolivia. Seventy-three participants (38 male) aged 6-82 years pointed a handheld global positioning system (GPS) unit toward the two nearest communities and the more distant market town. We find no evidence of sex differences in dead reckoning (p = 0.47), nor do we find any evidence of age-related decline in dead-reckoning accuracy (p = 0.28). Participants were significantly more accurate at pointing toward the market town than toward the two nearest villages despite its being significantly farther away than the two nearest communities. Although Tsimane do show sexual dimorphism in foraging tasks, Tsimane women have extensive daily and lifetime travel, and the local environment lacks directional cues that typically enhance male navigation. This study raises the possibility that greater similarity in mobility patterns because of overlapping subsistence strategies and activities may result in convergence of some male and female navigation abilities. PMID

  6. Motivational Counseling: Implications for Counseling Male Juvenile Sex Offenders

    ERIC Educational Resources Information Center

    Patel, Samir H.; Lambie, Glenn W.; Glover, Michelle Muenzenmeyer

    2008-01-01

    Juvenile sex offenders (JSOs) often appear unmotivated to change, which thus necessitates a therapeutic approach that matches "resistant" client characteristics. In this article, the authors review common traits of JSOs, introduce motivational counseling as an effective treatment modality, and offer a case illustration. (Contains 1 table and 1…

  7. The Profile and Treatment of Male Adolescent Sex Offenders.

    ERIC Educational Resources Information Center

    Lakey, Joyce F.

    1994-01-01

    Outlines characteristics of sex offenders, including family and school histories, sexual attitudes, social skills and relationships, delinquent behaviors, psychiatric diagnoses, and cognitive distortions based on mythical beliefs. Treatment requires correction of thinking errors and promotion of accountability, empathy, education, morality,…

  8. Activity of cholinesterases of blood and heart in rats of different sex and age during muscular loads and hypokinesia

    NASA Technical Reports Server (NTRS)

    Rozanova, V. D.; Antonova, G. A.

    1979-01-01

    The activity of acetylcholinesterase (Ache) and butyrilcholinesterase (Bche) in the blood and the heart of 3 and 13 month old control male rats is considerably lower than in female rats. In 25 month old rats, no sex differences in the Ache and Bche were revealed in the heart. In 3 and 13 month old male and female rats, under conditions of muscular exercises, the Ache and Bche activity is lower, and in hypokinetic male rats -- higher than that in respective control animals. In all the rats, irrespective of sex, age, and motor conditions, Ache and Bche activity tended to decrease from the sinoatrial node to the heart apex.

  9. Ageism, Sex, and Age: A Factorial Survey Approach.

    ERIC Educational Resources Information Center

    Baker, Paul M.

    1983-01-01

    Uses the factorial survey approach to measure directly the perceived status of various ages, and of both males and females. Results indicate that there is an inverted U-curve of status across the life span, and that the perceived status of females is lower than that of males in the midlife period. (Author/CT)

  10. Sex workers’ non-commercial male partners who inject drugs report higher risk sexual behaviors

    PubMed Central

    Robertson, Angela M.; Syvertsen, Jennifer L.; Palinkas, Lawrence A.; Vera, Alicia; Rangel, Gudelia; Martinez, Gustavo; Strathdee, Steffanie A

    2014-01-01

    Female sex workers (FSWs) are less likely to use condoms with non-commercial male partners than clients. We compare non-commercial male partners who do and do not inject drugs in Tijuana and Ciudad Juárez, Mexico. Sexual risk behaviors were more prevalent among injectors, who could promote HIV/STI transmission in this region. PMID:24275732

  11. The Tyranny of Surveillance: Male Teachers and the Policing of Masculinities in a Single Sex School

    ERIC Educational Resources Information Center

    Martino, Wayne; Frank, Blye

    2006-01-01

    This paper draws on research into male teachers in one single sex high school in the Australian context to highlight how issues of masculinity impact on their pedagogical practices and relationships with boys. The study is situated within the broader international field of research on male teachers, masculinities and schooling in Australia, the UK…

  12. Mental Health and Sexual Identity in a Sample of Male Sex Workers in the Czech Republic

    PubMed Central

    Bar-Johnson, Michael; Weiss, Petr

    2014-01-01

    Background Previous qualitative research has examined male sex workers in the Czech Republic, but this mapping study is the first to investigate male sex work in a quantitative research design and focus on the mental health of these sex workers. This study also examines male sex workers’ mental health problems in relation to their sexual identity or orientation. Material/Methods A sample of Czech male sex workers (N=40) were examined on a range of sexual and psychological variables using a quantitative survey administered face-to-face. The study employed locally validated versions of Beck’s Depression Inventory and Zung’s Self-Report Anxiety Scale. Results The results indicate that for homosexuals, working as a male sex worker is not related to any serious mental health problems. However, those identifying as heterosexual and bisexual more frequently reported symptoms of depression and bisexuals showed significantly more anxiety. Conclusions These findings suggest sexual identity is an important issue to consider when addressing the mental health needs of this population. PMID:25239091

  13. Androgen Deficiency and Dry Eye Syndrome in the Aging Male

    PubMed Central

    Azcarate, Patrick M.; Venincasa, Vincent D.; Feuer, William; Stanczyk, Frank; Schally, Andrew V.; Galor, Anat

    2014-01-01

    Purpose. To evaluate the relationship between androgen levels and subjective and objective measures of dry eye syndrome (DES). Methods. A total of 263 male patients from the Miami Veterans Affairs Medical Center eye clinic aged ≥50 were recruited for this prospective cross-sectional study. Patients completed Dry Eye Questionnaire 5, underwent tear film evaluation, and had serum androgen levels measured. The correlations between androgen levels, DES composite scores, DES symptoms, and global, lipid, and aqueous tear film parameters were evaluated. Results. Two hundred sixty-three patients with a mean age of 69 (50–95) were examined. There was no linear association between composite DES scores (generated using latent class analysis) and androgen levels. However, eyes with high DES scores (0.95–1.0) had higher levels of sex hormone-binding globulin (P = 0.03) and lower levels of dehydroepiandrosterone sulfate (DHEAS) (P = 0.02), androstenedione (A) (P = 0.02), and androstane-3α,17β-diol glucuronide (P = 0.03) compared to eyes with intermediate (0.05–0.95) or low (0–0.05) scores. There were no strong correlations between tear film measures and androgen levels. Regarding global parameters, a weak inverse correlation was found between corneal staining and A (r = −0.17, P = 0.009). For lipid parameters, a weak correlation existed between tear breakup time (TBUT) and A (r = 0.15, P = 0.02). When considering aqueous and lipid deficiency independently, the association between TBUT and A existed only with aqueous tear deficiency (r = 0.66, P = 0.002). Regarding aqueous parameters, a weak correlation existed between Schirmer test and DHEAS (r = 0.13, P = 0.047) and A (r = 0.21, P = 0.001). Conclusions. There was a weak correlation between higher levels of androstenedione and healthier global, lipid, and aqueous tear film parameters. PMID:24994872

  14. A qualitative study on commercial sex behaviors among male clients in Sichuan Province, China

    PubMed Central

    Yang, Cui; Latkin, Carl A.; Liu, Peng; Nelson, Kenrad E.; Wang, Cunlin; Luan, Rongsheng

    2015-01-01

    Males who seek commercial sex have been identified as an important “bridging population” in the transmission of HIV. There is little information on the HIV-related risk perceptions and behaviors among commercial sex male clients (CSMCs) in China. This study reports qualitative findings from six focus groups and 41 in-depth interviews with CSMCs in Sichuan Province, China. Commercial sex visits were described as a group activity and associated with patterns of social-network specific interactions and norms. Primary motivations for visiting female sex workers included peer pressure, stress reduction, and fulfilling a need for an intimate and emotional support. Male clients’ decisions about condom use were influenced by their perceived norms of condom use, susceptibility of HIV infection, and the condom policy and availability in the establishments. Implications of these findings for further research and interventions are discussed. PMID:20390503

  15. Age and Sex Differences in Controlled Force Exertion Measured by a Computing Bar Chart Target-Pursuit System

    ERIC Educational Resources Information Center

    Nagasawa, Yoshinori; Demura, Shinichi

    2009-01-01

    This study aimed to examine the age and sex differences in controlled force exertion measured by the bar chart display in 207 males (age 42.1 [plus or minus] 19.8 years) and 249 females (age 41.7 [plus or minus] 19.1 years) aged 15 to 86 years. The subjects matched their submaximal grip strength to changing demand values, which appeared as a…

  16. An oral male courtship pheromone terminates the response of Nasonia vitripennis females to the male-produced sex attractant.

    PubMed

    Ruther, Joachim; Hammerl, Theresa

    2014-01-01

    Sex pheromones are crucial for mate finding in many animals. Long-range attraction, mate recognition, and the elicitation of sexual receptiveness during courtship are typically mediated by different compounds. It is widely unknown, however, how the different components of a species' pheromone system influence each other. Here, we demonstrated in the parasitoid wasp Nasonia vitripennis that females quickly cease to respond to the male sex attractant after they contact a male's oral secretion during courtship. We used this behavioral switch to monitor the fractionation of head extracts from male wasps for identification of the bioactive compounds as a blend of ethyl oleate, ethyl linoleate, and ethyl α-linolenate. This is the first identification of a cephalic courtship pheromone in parasitic Hymenoptera. Plasticity in pheromone-mediated sexual behavior of female insects has hitherto been attributed to the transfer of bioactive proteinaceous molecules with the male ejaculate. The pheromone interaction reported here sheds new light on the sexual communication of insects by showing that the sex pheromone response of females can be terminated by males independent of sperm transfer. PMID:24369389

  17. Medical management of erectile dysfunction in aging males: Is it too late to treat?

    PubMed Central

    Zhang, Kai; Xu, Ben; Liu, De-Feng; Wang, Xiao-Feng; Zhu, Ji-Chuan; Jin, Jie; Jiang, Hui

    2014-01-01

    Erectile dysfunction (ED) is a common disorder among aging males. However, most aging males refuse to seek medical help and believe that ED is an irreversible event in the aging process. The purpose of this study was to describe the current medical management of ED in aging males and to examine whether it is too late to treat this disorder in these elderly men. From 2007 to 2008, 4507 patients diagnosed with ED were gathered from 46 centers in China; 4241 completed the study, 3837 of whom were treated with sildenafil. The 3837 patients were divided into five groups based on age (group A: 20–30 years; group B: 31–40 years; group C: 41–50 years; group D: 51–60 years; and group E: >60 years). After comparing pre- and posttreatment International Index of Erectile Function-Erectile Function domain (IIEF-EF) questionnaires, Erection Hardness Scale (EHS), and IIEF Q13 (“How satisfied have you been with your overall sex life?”), we discovered that the aging males had worse erectile function, erection hardness, and sexual satisfaction than the younger males (P < 0.001). After treatment, the improvement rates in the IIEF-EF, EHS, and IIEF Q13 scores were 107.0%, 83.1%, and 116.5%, respectively. The magnitude of these changes demonstrated significant differences among groups (P < 0.001). Accordingly, aging males are likely to benefit more from medical treatment. We propose that aging males should be informed that age is not a limiting factor for medical ED management, and it is never too late to treat. PMID:24369150

  18. Testosterone deficiency in the aging male

    PubMed Central

    McBride, J. Abram; Carson, Culley C.; Coward, Robert M.

    2016-01-01

    Treatment for hypogonadism is on the rise, particularly in the aging population. Yet treatment in this population represents a unique challenge to clinicians. The physiology of normal aging is complex and often shares the same, often vague, symptoms of hypogonadism. In older men, a highly prevalent burden of comorbid medical conditions and polypharmacy complicates the differentiation of signs and symptoms of hypogonadism from those of normal aging, yet this differentiation is essential to the diagnosis of hypogonadism. Even in older patients with unequivocally symptomatic hypogonadism, the clinician must navigate the potential benefits and risks of treatment that are not clearly defined in older men. More recently, a greater awareness of the potential risks associated with treatment in older men, particularly in regard to cardiovascular risk and mortality, have been appreciated with recent changes in the US Food and Drug Administration recommendations for use of testosterone in aging men. The aim of this review is to provide a framework for the clinician evaluating testosterone deficiency in older men in order to identify correctly and treat clinically significant hypogonadism in this unique population while minimizing treatment-associated harm. PMID:26834840

  19. Phf7 controls male sex determination in the Drosophila germline

    PubMed Central

    Yang, Shu Yuan; Baxter, Ellen M.; Van Doren, Mark

    2013-01-01

    Summary Establishment of germline sexual identity is critical for production of male and female germline stem cells, and sperm vs. eggs. Here we identify PHD Finger Protein 7 (PHF7) as an important factor for male germline sexual identity in Drosophila. PHF7 exhibits male-specific expression in early germ cells, germline stem cells and spermatogonia. It is required for germline stem cell maintenance and gametogenesis in males, whereas ectopic expression in female germ cells ablates the germline. Strikingly, expression of PHF7 promotes spermatogenesis in XX germ cells when they are present in a male soma. PHF7 homologs are also specifically expressed in the mammalian testis, and human PHF7 rescues Drosophila Phf7 mutants. PHF7 associates with chromatin and both the human and fly proteins bind histone H3 N-terminal tails with a preference for dimethyl lysine 4 (H3K4me2). We propose that PHF7 acts as a conserved epigenetic “reader” that activates the male germline sexual program. PMID:22595675

  20. Human male sex determination and sexual differentiation: pathways, molecular interactions and genetic disorders.

    PubMed

    Kucinskas, Laimutis; Just, Walter

    2005-01-01

    The complex mechanisms are responsible for male sex determination and differentiation. The steps of formation of the testes are dependent on a series of Y-linked, X-linked and autosomal genes actions and interactions. After formation of testes the gonads secrete hormones, which are essential for the formation of the male genitalia. Hormones are transcription regulators, which function by specific receptors. Ambiguous genitalia are result of disruption of genetic interaction. This review describes the mechanisms, which lead to differentiation of male sex and ways by which the determination and differentiation may be interrupted by naturally occurring mutations, causing different syndromes and diseases. PMID:16160410

  1. Antiretroviral Therapy as a Factor Protective against Anal Dysplasia in HIV-Infected Males Who Have Sex with Males

    PubMed Central

    Hidalgo-Tenorio, Carmen; Rivero-Rodriguez, Mar; Gil-Anguita, Concepción; Lopez De Hierro, Mercedes; Palma, Pablo; Ramírez-Taboada, Jessica; Esquivias, Javier; López-Ruz, Miguel Angel; Javier-Martínez, Rosario; Pasquau-Liaño, Juan

    2014-01-01

    Objectives Chronic infection with oncogenic HPV genotype is associated with the development of anal dysplasia. Antiretroviral therapy (ART) has been shown to decrease the incidence of cervical carcinoma in women with HIV. We sought to: 1) describe the prevalence and grade of anal dysplasia and HPV infection in our study subjects; 2) analyze the grade of correlation between anal cytology, PCR of high-risk HPV, and histology; 3) identify the factors associated with the appearance of ≥AIN2 lesions. Design Cross-sectional, prospective study. Methods A cohort of HIV-positive males (n = 140, mean age  = 37 years) who have sex with males (MSM) had epidemiological, clinical and analytical data collected. Anal mucosa samples were taken for cytology, HPV PCR genotyping, and anoscopy for histological analysis. Results Within the cohort, 77.1% were being treated with ART, 8.5% anoscopy findings were AIN2, and 11.4% carcinoma in situ; 74.2% had high-risk (HR), 59.7% low-risk (LR) HPV genotypes and 46.8% had both. The combination of cytology with PCR identifying HR-HPV better predicts the histology findings than either of these factors alone. Logistic regression highlighted ART as a protective factor against ≥AIN2 lesions (OR: 0.214; 95%CI: 0.054–0.84). Anal/genital condylomas (OR: 4.26; 95%CI: 1.27–14.3), and HPV68 genotype (OR: 10.6; 95%CI: 1.23–91.47) were identified as risk factors. Conclusions In our cohort, ART has a protective effect against dysplastic anal lesions. Anal/genital warts and HPV68 genotype are predictors of ≥AIN2 lesions. Introducing PCR HPV genotype evaluation improves screening success over that of cytology alone. PMID:24676139

  2. Female Choice or Male Sex Drive? The Advantages of Male Body Size during Mating in Drosophila Melanogaster.

    PubMed

    Jagadeeshan, Santosh; Shah, Ushma; Chakrabarti, Debarti; Singh, Rama S

    2015-01-01

    The mating success of larger male Drosophila melanogaster in the laboratory and the wild has been traditionally been explained by female choice, even though the reasons are generally hard to reconcile. Female choice can explain this success by virtue of females taking less time to mate with preferred males, but so can the more aggressive or persistent courtships efforts of large males. Since mating is a negotiation between the two sexes, the behaviors of both are likely to interact and influence mating outcomes. Using a series of assays, we explored these negotiations by testing for the relative influence of male behaviors and its effect on influencing female courtship arousal threshold, which is the time taken for females to accept copulation. Our results show that large males indeed have higher copulation success compared to smaller males. Competition between two males or an increasing number of males had no influence on female sexual arousal threshold;-females therefore may have a relatively fixed 'arousal threshold' that must be reached before they are ready to mate, and larger males appear to be able to manipulate this threshold sooner. On the other hand, the females' physiological and behavioral state drastically influences mating; once females have crossed the courtship arousal threshold they take less time to mate and mate indiscriminately with large and small males. Mating quicker with larger males may be misconstrued to be due to female choice; our results suggest that the mating advantage of larger males may be more a result of heightened male activity and relatively less of female choice. Body size per se may not be a trait under selection by female choice, but size likely amplifies male activity and signal outputs in courtship, allowing them to influence female arousal threshold faster. PMID:26658421

  3. Age-Specific Sex-Related Differences in Infections: A Statistical Analysis of National Surveillance Data in Japan

    PubMed Central

    Eshima, Nobuoki; Tokumaru, Osamu; Hara, Shohei; Bacal, Kira; Korematsu, Seigo; Karukaya, Shigeru; Uruma, Kiyo; Okabe, Nobuhiko; Matsuishi, Toyojiro

    2012-01-01

    Background To prevent and control infectious diseases, it is important to understand how sex and age influence morbidity rates, but consistent clear descriptions of differences in the reported incidence of infectious diseases in terms of sex and age are sparse. Methods and Findings Data from the Japanese surveillance system for infectious diseases from 2000 to 2009 were used in the analysis of seven viral and four bacterial infectious diseases with relatively large impact on the Japanese community. The male-to-female morbidity (MFM) ratios in different age groups were estimated to compare incidence rates of symptomatic reported infection between the sexes at different ages. MFM ratios were >1 for five viral infections out of seven in childhood, i.e. male children were more frequently reported as infected than females with pharyngoconjunctival fever, herpangina, hand-foot-and-mouth disease, mumps, and varicella. More males were also reported to be infected with erythema infectiosum and exanthema subitum, but only in children 1 year of age. By contrast, in adulthood the MFM ratios decreased to <1 for all of the viral infections above except varicella, i.e. adult women were more frequently reported to be infected than men. Sex- and age-related differences in reported morbidity were also documented for bacterial infections. Reported morbidity for enterohemorrhagic Escherichia coli infection was higher in adult females and females were reportedly more infected with mycoplasma pneumonia than males in all age groups up to 70 years. Conclusions Sex-related differences in reported morbidity for viral and bacterial infections were documented among different age groups. Changes in MFM ratios with age may reflect differences between the sexes in underlying development processes, including those affecting the immune, endocrine, and reproductive systems, or differences in reporting rates. PMID:22848753

  4. Age- and sex-related changes in the normal human ear.

    PubMed

    Sforza, Chiarella; Grandi, Gaia; Binelli, Miriam; Tommasi, Davide G; Rosati, Riccardo; Ferrario, Virgilio F

    2009-05-30

    The objective of this study was to supply information about: (1) normal sex-related dimensions of ears (linear distances and ratios, area); (2) left-right symmetry; and (3) growth changes between childhood and old age. The three-dimensional coordinates of several soft-tissue landmarks on the ears and face were obtained by a non-invasive, computerized electromagnetic digitizer in 497 male and 346 female healthy subjects aged 4-73 years. From the landmarks, paired ear width and length, the relevant ratios, ear areas and angles relative to the facial midline, as well as indices of left-right symmetry, were calculated, and averaged for age and sex. Comparisons were performed by factorial analysis of variance. All ear dimensions were significantly larger in men than in women (p<0.001). A significant effect of age was found (p<0.001), with larger values in older individuals. The ear width-to-length ratio and the sagittal angle of the auricle significantly decreased as a function of age (p<0.001) but without sex-related differences. On average, the three-dimensional position of ears was symmetric, with symmetry coefficients ranging between 92% and 96%. Asymmetry was found in the sagittal angle of the auricle (both sexes), in the ear width-to-length ratio and ear width (men only). Data collected in the present investigation could serve as a data base for the quantitative description of human ear morphology and position during normal growth, development and aging. Forensic applications (evaluations of traumas, craniofacial alterations, teratogenic-induced conditions, facial reconstruction, aging of living and dead persons, personal identification) may also benefit from age- and sex-based data banks. PMID:19356871

  5. Age- and Sex-Dependency of Laser Speckle Flowgraphy Measurements of Optic Nerve Vessel Microcirculation

    PubMed Central

    Aizawa, Naoko; Kunikata, Hiroshi; Nitta, Fumihiko; Shiga, Yukihiro; Omodaka, Kazuko; Tsuda, Satoru; Nakazawa, Toru

    2016-01-01

    Purpose To investigate the relationship between various characteristics of a normal population and laser speckle flowgraphy (LSFG) measurements of mean blur rate (MBR) in the optic nerve head (ONH). Methods A total of 189 eyes of 189 normal subjects (93 male, 96 female, mean age 45 ± 14 years old, age range: 20–72) without any history of hypertension, hyperlipidemia or diabetes were enrolled. ONH microcirculation was measured with LSFG and overall MBR (MA), vessel-area MBR (MV), and tissue-area MBR (MT) were derived from these measurements. The statistical association of these measurements with characteristics such as sex, age, intraocular pressure (IOP) and systolic blood pressure (SBP) was then determined. Results There was a trend towards decreased IOP and MV and increased SBP with age (P = 0.002, P = 0.035, and P = 0.006, respectively). Furthermore, IOP, MV and SBP were correlated with age (r = -0.23, P = 0.011; r = -0.24, P < 0.001; and r = 0.30, P < 0.001, respectively). Separate multiple regression analyses of independent contributing factors revealed that sex and IOP contributed to MA (P < 0.001 and P = 0.002, respectively), sex, IOP, and age contributed to MV (P < 0.001, P = 0.003, and P = 0.024, respectively), while only IOP contributed to MT (P = 0.003). Conclusion In a normal population, MBR was affected by IOP in both the large vessel and capillary areas of the ONH, but not by SBP. MV was also affected by age and sex, while MT was stable independent of age or sex. PMID:26872348

  6. Male facial attractiveness and masculinity may provide sex- and culture-independent cues to semen quality.

    PubMed

    Soler, C; Kekäläinen, J; Núñez, M; Sancho, M; Álvarez, J G; Núñez, J; Yaber, I; Gutiérrez, R

    2014-09-01

    Phenotype-linked fertility hypothesis (PLFH) predicts that male secondary sexual traits reveal honest information about male fertilization ability. However, PLFH has rarely been studied in humans. The aim of the present study was to test PLFH in humans and to investigate whether potential ability to select fertile partners is independent of sex or cultural background. We found that on the contrary to the hypothesis, facial masculinity was negatively associated with semen quality. As increased levels of testosterone have been demonstrated to impair sperm production, this finding may indicate a trade-off between investments in secondary sexual signalling (i.e. facial masculinity) and fertility or status-dependent differences in investments in semen quality. In both sexes and nationalities (Spanish and Colombian), ranked male facial attractiveness predicted male semen quality. However, Spanish males and females estimated facial images generally more attractive (gave higher ranks) than Colombian raters, and in both nationalities, males gave higher ranks than females. This suggests that male facial cues may provide culture- and sex-independent information about male fertility. However, our results also indicate that humans may be more sensitive to facial attractiveness cues within their own populations and also that males may generally overestimate the attractiveness of other men to females. PMID:25056484

  7. Age- and sex-related changes in the normal human external nose.

    PubMed

    Sforza, Chiarella; Grandi, Gaia; De Menezes, Marcio; Tartaglia, Gianluca M; Ferrario, Virgilio F

    2011-01-30

    The objective of this study was to measure: (1) normal sex-related dimensions of external nose (linear distances, ratios, angles, volume and surface area); and (2) growth changes between childhood and old age. The three-dimensional coordinates of several soft-tissue landmarks on the external nose were obtained by a non-invasive, computerized digitizer in 519 male and 340 female healthy subjects aged 4-73 years. The subjects were divided into 11 non-overlapping age groups: for children and preadolescent subjects, 2-year spans were used, while larger intervals were used for adolescent and adult subjects. From the landmarks, nasal volume and external surface area; nasal and alar base widths, nasal height, nasal bridge length, philtrum length, nasal tip protrusion, right and left nostril lengths, superior and inferior nostril widths; nasal tip protrusion-to-nasal height, and nasal width-to-nasal height ratios; nasal convexity, alar slope, and nasal tip angles were calculated, and averaged for age and sex. Comparisons were performed by factorial analysis of variance. On average, men had larger nasal external volume and area, linear distances and nasal width-to-height ratio than women (p<0.01); no sex differences were found for the angles and the nasal tip protrusion-to-nasal height ratio. Age significantly influenced all analyzed measurements (p<0.001): nasal volume, area, linear distances increased from childhood to old age, while the nasal tip angle decreased as a function of age. No consistent age related patterns were found for the ratios and the nasal convexity and alar slope angles. Men and women had different age related patterns, with significant sex by age interactions (p<0.001). Overall, in most occasions male increments in nasal dimensions were larger than female ones. Data collected in the present investigation could serve as a database for the quantitative description of human nasal morphology during normal growth, development and aging. Forensic

  8. Shear Wave Elastography of Passive Skeletal Muscle Stiffness: Influences of Sex and Age throughout Adulthood

    PubMed Central

    Eby, Sarah F.; Cloud, Beth A.; Brandenburg, Joline E.; Giambini, Hugo; Song, Pengfei; Chen, Shigao; LeBrasseur, Nathan K.; An, Kai-Nan

    2014-01-01

    Background Numerous structural and compositional changes – related not only to age, but also activity level and sex – may affect skeletal muscle stiffness across the adult age-span. Measurement techniques available thus far have largely limited passive stiffness evaluations to those of entire joints and muscle-tendon units. Shear wave elastography is an increasingly popular ultrasound technique for evaluating the mechanical properties of skeletal muscle tissue. The purpose of this study was to quantify the passive stiffness, or shear modulus, of the biceps brachii throughout adulthood in flexed and extended elbow positions. We hypothesized that shear modulus would be higher in males relative to females, and with advanced age in both sexes. Methods Shear wave elastography quantified biceps brachii stiffness at 90° elbow flexion and full extension in a large sample of adults between 21–94 years old (n=133; 47 males). Findings Regression analysis found sex and age were significant parameters for older adults (>60 years) in full extension. As expected, shear modulus values increased with advancing age; however, shear modulus values for females tended to be higher than those for males. Interpretation This study begins to establish normative trends for skeletal muscle shear modulus throughout adulthood. Specifically, this work establishes for the first time that the higher passive joint torque often found in males relative to females likely relates to parameters other than muscle shear modulus. Indeed, perhaps increases in skeletal muscle passive stiffness, though potentially altering the length-tension curve, serve a protective role – maintaining the tendon-muscle-tendon length-tension curve within a functional range. PMID:25483294

  9. Sex- and age-related mortality profiles during famine: testing the 'body fat' hypothesis.

    PubMed

    Speakman, John R

    2013-11-01

    During famines females generally have a mortality advantage relative to males, and the highest levels of mortality occur in the very young and the elderly. One popular hypothesis is that the sex differential in mortality may reflect the greater body fatness combined with lower metabolism of females, which may also underpin the age-related patterns of mortality among adults. This study evaluated the 'body fat' hypothesis using a previously published and validated mathematical model of survival during total starvation. The model shows that at a given body weight females would indeed be expected to survive considerably longer than males in the absence of food. At a mass of 70 kg for example a female aged 30 would survive for 144 days compared with life expectancy of only 95 days for a male of the same age and weight. This effect is contributed to by both the higher body fatness and lower metabolism of the females at a given body weight. However, females are generally smaller than males and in addition to a sex effect there was also a major effect of body size - heavier individuals survive longer. When this body size effect was removed by considering survival in relation to BMI the sex effect was much reduced, and could be offset by a relatively small difference in pre-famine BMI between the sexes. Nevertheless, combining these predictions with observed mean BMIs of males and females across 48 countries at the low end of the obesity spectrum suggests that in the complete absence of food females would survive on average about 40% longer (range 6 to 64.5%) than males. The energy balance model also predicted that older adult individuals should survive much longer than younger adult individuals, by virtue of their lower resting metabolic rates and lower activity levels. Observations of the female survival advantage in multiple famines span a much wider range than the model prediction (5% to 210%). This suggests in some famines body fatness may be a significant factor

  10. Age-based discrimination of rival males in western bluebirds.

    PubMed

    Akçay, Çağlar; Arnold, J Andrew; Hambury, Katherine L; Dickinson, Janis L

    2016-09-01

    Adaptive social behavior frequently involves discriminating between classes of individuals such as relatives versus non-relatives, older versus younger individuals, or individuals of different status. In the absence of spatial cues, this discrimination may be based on signals that correlate with fitness-related traits (e.g., older or high-status males may sing higher performance songs) or with identity, for example, when receivers distinguish and classify signalers based on their unique signal structure. Here, we examine vocal age-based discrimination in western bluebirds (Sialia mexicana), a North American songbird in which older males have a significant advantage in obtaining extra-pair fertilizations, and therefore pose a significantly higher threat to paternity than younger males. We asked whether western bluebird males showed a higher response to playback of songs of older males compared to younger males relative to their own age. We prepared song stimuli by removing three potential signals of age that have been identified as important in other species: (1) note consistency (which was achieved by playing a single instance of each note repeatedly), (2) note repertoire size, and (3) singing rate (the latter two were equalized across conditions). Even in the absence of these potential signals of age, young males responded more strongly to playback of older males' songs than to young males' songs, suggesting that they are able to discriminate between age classes relative to the threat they pose. Further research is required to determine whether this discrimination is based on individual recognition or signal features that are correlated with age. PMID:27271774

  11. Fetal Habituation Performance: Gestational Age and Sex Effects

    ERIC Educational Resources Information Center

    McCorry, Noleen K.; Hepper, Peter G.

    2007-01-01

    Habituation is the decrement in response to repeated stimulation. Fetal habituation performance may reflect the functioning of the central nervous system (CNS) prenatally. However, basic characteristics of the prenatal habituation phenomena remain unclear, such as the relationship with gestational age (GA) and fetal sex. The current study…

  12. Effect of Withania somnifera (L.) Dunal on Sex Hormone and Gonadotropin Levels in Addicted Male Rats

    PubMed Central

    Rahmati, Batool; Ghosian Moghaddam, Mohammad Hassan; Khalili, Mohsen; Enayati, Ehsan; Maleki, Maryam; Rezaeei, Saeedeh

    2016-01-01

    Background Opioid consumption has been widely increasing across the globe; how- ever, it can cause adverse effects on the body. Morphine, an opioid, can reduce sex hor- mones and fertility. Withania somnifera (WS) is a traditional herb used to improve sexual activities. This study strives to investigate the effect of WS on sex hormones and gonado- tropins in addicted male rats. Materials and Methods In this experimental study, forty-eight male National Maritime Research Institute (NMRI) rats were randomly divided into four groups: i. Control group, ii. WS-treated control group, iii. Addicted group, and iv. WS-treated addicted group. Wa- ter-soluble morphine was given to rats for 21 days to induce addiction, concurrently the treated groups (2 and 4) also received WS plant-mixed pelleted food (6.25%). At the end of the treatment, the sex hormone and gonadotropin levels of the rats’ sera were deter- mined in all the groups. Results Except for follicle-stimulating hormone (FSH), morphine reduced most of the gonadotropin and sex hormone levels. Whereas WS caused a considerable increase in the hormones in the treated addicted group, there was only a slight increase in the treated control group. Conclusion WS increased sex hormones and gonadotropins-especially testosterone, es- trogen, and luteinizing hormone-in the addicted male rats and even increased the proges- terone level, a stimulant of most sex hormones in addicted male rats. PMID:27441058

  13. Alcohol Use Among Female Sex Workers and Male Clients: An Integrative Review of Global Literature

    PubMed Central

    Li, Qing; Li, Xiaoming; Stanton, Bonita

    2010-01-01

    Aims: To review the patterns, contexts and impacts of alcohol use associated with commercial sex reported in the global literature. Methods: We identified peer-reviewed English-language articles from 1980 to 2008 reporting alcohol consumption among female sex workers (FSWs) or male clients. We retrieved 70 articles describing 76 studies, in which 64 were quantitative (52 for FSWs, 12 for male clients) and 12 qualitative. Results: Studies increased over the past three decades, with geographic concentration of the research in Asia and North America. Alcohol use was prevalent among FSWs and clients. Integrating quantitative and qualitative studies, multilevel contexts of alcohol use in the sex work environment were identified, including workplace and occupation-related use, the use of alcohol to facilitate the transition into and practice of commercial sex among both FSWs and male clients, and self-medication among FSWs. Alcohol use was associated with adverse physical health, illicit drug use, mental health problems, and victimization of sexual violence, although its associations with HIV/sexually transmitted infections and unprotected sex among FSWs were inconclusive. Conclusions: Alcohol use in the context of commercial sex is prevalent, harmful among FSWs and male clients, but under-researched. Research in this area in more diverse settings and with standardized measures is required. The review underscores the importance of integrated intervention for alcohol use and related problems in multilevel contexts and with multiple components in order to effectively reduce alcohol use and its harmful effects among FSWs and their clients. PMID:20089544

  14. Effects of age and sex on the pharmacokinetics of LCZ696, an angiotensin receptor neprilysin inhibitor.

    PubMed

    Gan, Lu; Langenickel, Thomas; Petruck, Jesika; Kode, Kiran; Rajman, Iris; Chandra, Priya; Zhou, Wei; Rebello, Sam; Sunkara, Gangadhar

    2016-01-01

    LCZ696, a novel angiotensin receptor neprilysin inhibitor, is in development for the treatment of heart failure. Administration of LCZ696 results in systemic exposure to sacubitril (inactive prodrug of LBQ657), LBQ657 (neprilysin inhibitor), and valsartan (angiotensin II receptor blocker). We investigated the potential effects of age and sex on the pharmacokinetics of LCZ696 analytes (LBQ657 and valsartan) in an open-label, single oral dose (400 mg), parallel-group study in healthy subjects. Among 36 enrolled subjects, there were 19 male and 17 female subjects; 18 subjects were 18-45 years old (young), and 18 subjects were 65 years of age or older (elderly). Compared with young subjects, the AUCinf and T1/2 for LBQ657 were 42% and 30% greater, respectively, in elderly subjects. The Cmax for LBQ657 was similar between age groups. The AUCinf, Cmax, and T1/2 for valsartan were 30%, 24% greater, and 3.35 hours longer, respectively, in the elderly when compared with young subjects. All pharmacokinetic parameters of LCZ696 analytes (LBQ657 and valsartan) were similar between male and female subjects, indicating no effect on the pharmacokinetics of LCZ696 analytes based on sex. Considering the magnitude of change and its clinical significance, dose adjustment based on age or sex is not considered necessary. PMID:26073563

  15. Does breeding population trajectory and age of nesting females influence disparate nestling sex ratios in two populations of Cooper's hawks?

    PubMed

    Rosenfield, Robert N; Stout, William E; Giovanni, Matthew D; Levine, Noah H; Cava, Jenna A; Hardin, Madeline G; Haynes, Taylor G

    2015-09-01

    Offspring sex ratios at the termination of parental care should theoretically be skewed toward the less expensive sex, which in most avian species would be females, the smaller gender. Among birds, however, raptors offer an unusual dynamic because they exhibit reversed size dimorphism with females being larger than males. And thus theory would predict a preponderance of male offspring. Results for raptors and birds in general have been varied although population-level estimates of sex ratios in avian offspring are generally at unity. Adaptive adjustment of sex ratios in avian offspring is difficult to predict perhaps in part due to a lack of life-history details and short-term investigations that cannot account for precision or repeatability of sex ratios across time. We conducted a novel comparative study of sex ratios in nestling Cooper's hawks (Accipiter cooperii) in two study populations across breeding generations during 11 years in Wisconsin, 2001-2011. One breeding population recently colonized metropolitan Milwaukee and exhibited rapidly increasing population growth, while the ex-Milwaukee breeding population was stable. Following life-history trade-off theory and our prediction regarding this socially monogamous species in which reversed sexual size dimorphism is extreme, first-time breeding one-year-old, second-year females in both study populations produced a preponderance of the smaller and cheaper sex, males, whereas ASY (after-second-year), ≥2-year-old females in Milwaukee produced a nestling sex ratio near unity and predictably therefore a greater proportion of females compared to ASY females in ex-Milwaukee who produced a preponderance of males. Adjustment of sex ratios in both study populations occurred at conception. Life histories and selective pressures related to breeding population trajectory in two age cohorts of nesting female Cooper's hawk likely vary, and it is possible that these differences influenced the sex ratios we documented for

  16. Sex recognition and mate choice by male Bufo gargarizans in central China.

    PubMed

    Yu, Tong Lei; Sharma, Manmohan D

    2012-06-01

    Mate choice is important for successful reproduction, and consequently species have evolved various ways to choose potential high-quality mates. Anuran mate choice and underlying processes have been the subject of several recent investigations, however we are far from a complete understanding of mate choice in this system. In the present study, when given a simultaneous choice between a male and a female of identical size, males did not discriminate between the sexes, and attempted to clasp a male or a female with equal frequency. Test males only released the stimulus toad when a release call was emitted by the stimulus male. When two males with distinct size differences were provided with a male, the male chose the larger one. Moreover, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones. These results suggest that male Bufo gargarizans can discriminate between the sexes, probably based on male release calls, and prefer to mate with larger individual using visual cues. PMID:22639803

  17. Age and Sex Differences in Rates of Influenza-Associated Hospitalizations in Hong Kong.

    PubMed

    Wang, Xi-Ling; Yang, Lin; Chan, Kwok-Hung; Chan, King-Pan; Cao, Pei-Hua; Lau, Eric Ho-Yin; Peiris, J S Malik; Wong, Chit-Ming

    2015-08-15

    Few studies have explored age and sex differences in the disease burden of influenza, although men and women probably differ in their susceptibility to influenza infections. In this study, quasi-Poisson regression models were applied to weekly age- and sex-specific hospitalization numbers of pneumonia and influenza cases in the Hong Kong SAR, People's Republic of China, from 2004 to 2010. Age and sex differences were assessed by age- and sex-specific rates of excess hospitalization for influenza A subtypes A(H1N1), A(H3N2), and A(H1N1)pdm09 and influenza B, respectively. We found that, in children younger than 18 years, boys had a higher excess hospitalization rate than girls, with the male-to-female ratio of excess rate (MFR) ranging from 1.1 to 2.4. MFRs of hospitalization associated with different types/subtypes were less than 1.0 for adults younger than 40 years except for A(H3N2) (MFR = 1.6), while all the MFRs were equal to or higher than 1.0 in adults aged 40 years or more except for A(H1N1)pdm09 in elderly persons aged 65 years or more (MFR = 0.9). No MFR was found to be statistically significant (P < 0.05) for hospitalizations associated with influenza type/subtype. There is some limited evidence on age and sex differences in hospitalization associated with influenza in the subtropical city of Hong Kong. PMID:26219977

  18. Manual control age and sex differences in 4 to 11 year old children.

    PubMed

    Flatters, Ian; Hill, Liam J B; Williams, Justin H G; Barber, Sally E; Mon-Williams, Mark

    2014-01-01

    To what degree does being male or female influence the development of manual skills in pre-pubescent children? This question is important because of the emphasis placed on developing important new manual skills during this period of a child's education (e.g. writing, drawing, using computers). We investigated age and sex-differences in the ability of 422 children to control a handheld stylus. A task battery deployed using tablet PC technology presented interactive visual targets on a computer screen whilst simultaneously recording participant's objective kinematic responses, via their interactions with the on-screen stimuli using the handheld stylus. The battery required children use the stylus to: (i) make a series of aiming movements, (ii) trace a series of abstract shapes and (iii) track a moving object. The tasks were not familiar to the children, allowing measurement of a general ability that might be meaningfully labelled 'manual control', whilst minimising culturally determined differences in experience (as much as possible). A reliable interaction between sex and age was found on the aiming task, with girls' movement times being faster than boys in younger age groups (e.g. 4-5 years) but with this pattern reversing in older children (10-11 years). The improved performance in older boys on the aiming task is consistent with prior evidence of a male advantage for gross-motor aiming tasks, which begins to emerge during adolescence. A small but reliable sex difference was found in tracing skill, with girls showing a slightly higher level of performance than boys irrespective of age. There were no reliable sex differences between boys and girls on the tracking task. Overall, the findings suggest that prepubescent girls are more likely to have superior manual control abilities for performing novel tasks. However, these small population differences do not suggest that the sexes require different educational support whilst developing their manual skills. PMID

  19. Effects of age and sex on neuromuscular-mechanical determinants of muscle strength.

    PubMed

    Wu, Rui; Delahunt, Eamonn; Ditroilo, Massimiliano; Lowery, Madeleine; De Vito, Giuseppe

    2016-06-01

    The aim of this study was to concurrently assess the effect of age on neuromuscular and mechanical properties in 24 young (23.6 ± 3.7 years) and 20 older (66.5 ± 3.8 years) healthy males and females. Maximal strength of knee extensors (KE) and flexors (KF), contractile rate of torque development (RTD) and neural activation of agonist-antagonist muscles (surface EMG) were examined during maximal voluntary isometric contraction (MVIC). Tissue stiffness (i.e. musculo-articular stiffness (MAS) and muscle stiffness (MS)) was examined via the free-oscillation technique, whereas muscle architecture (MA) of the vastus lateralis and subcutaneous fat were measured by ultrasonography. Males exhibited a greater age-related decline for KE (47.4 %) and KF (53.1 %) MVIC, and RTD (60.4 %) when compared to females (32.9, 42.6 and 34.0 %, respectively). Neural activation of agonist muscles during KE MVIC falls markedly with ageing; however, no age and sex effects were observed in the antagonist co-activation. MAS and MS were lower in elderly compared with young participants and in females compared with males. Regarding MA, main effects for age (young 23.0 ± 3.3 vs older 19.5 ± 2.0 mm) and sex (males 22.4 ± 3.5 vs females 20.4 ± 2.7 mm) were detected in muscle thickness. For fascicle length, there was an effect of age (young 104.6 ± 8.8 vs older 89.8 ± 10.5 mm), while for pennation angle, there was an effect of sex (males 13.3 ± 2.4 vs females 11.5 ± 1.7°). These findings suggest that both neuromuscular and mechanical declines are important contributors to the age-related loss of muscle strength/function but with some peculiar sex-related differences. PMID:27189591

  20. Caries Experience Differs between Females and Males across Age Groups in Northern Appalachia

    PubMed Central

    Shaffer, John R.; Leslie, Elizabeth J.; Feingold, Eleanor; Govil, Manika; McNeil, Daniel W.; Crout, Richard J.; Weyant, Robert J.; Marazita, Mary L.

    2015-01-01

    Sex disparities in dental caries have been observed across many populations, with females typically exhibiting higher prevalence and more affected teeth. In this study we assessed the sex disparities in two Northern Appalachian populations from West Virginia (WV, N = 1997) and Pennsylvania (PA, N = 1080) by comparing caries indices between males and females across four phases of dental development: primary dentition in children aged 1–5 years, mixed dentition in children aged 6–11 years, permanent dentition in adolescents aged 12–17 years, and permanent dentition in adults aged 18–59 years. No significant sex differences were observed for children aged 1–5 years. Contrary to national and international trends, WV girls aged 6–11 years had 1.5 fewer affected teeth than boys (p < 0.001). However, by ages 12–17, caries indices in the WV girls matched those in boys. In both WV and PA adults, women and men had similar total counts of affected teeth (i.e., DMFT), although women had more dental restorations (p < 0.001) and men had more current decay (p < 0.001). These results suggest that in some Appalachian populations, young girls benefit from protection against caries that is lost during adolescence and that adult women utilize dental health care to a greater degree than men. PMID:26106416

  1. Caries Experience Differs between Females and Males across Age Groups in Northern Appalachia.

    PubMed

    Shaffer, John R; Leslie, Elizabeth J; Feingold, Eleanor; Govil, Manika; McNeil, Daniel W; Crout, Richard J; Weyant, Robert J; Marazita, Mary L

    2015-01-01

    Sex disparities in dental caries have been observed across many populations, with females typically exhibiting higher prevalence and more affected teeth. In this study we assessed the sex disparities in two Northern Appalachian populations from West Virginia (WV, N = 1997) and Pennsylvania (PA, N = 1080) by comparing caries indices between males and females across four phases of dental development: primary dentition in children aged 1-5 years, mixed dentition in children aged 6-11 years, permanent dentition in adolescents aged 12-17 years, and permanent dentition in adults aged 18-59 years. No significant sex differences were observed for children aged 1-5 years. Contrary to national and international trends, WV girls aged 6-11 years had 1.5 fewer affected teeth than boys (p < 0.001). However, by ages 12-17, caries indices in the WV girls matched those in boys. In both WV and PA adults, women and men had similar total counts of affected teeth (i.e., DMFT), although women had more dental restorations (p < 0.001) and men had more current decay (p < 0.001). These results suggest that in some Appalachian populations, young girls benefit from protection against caries that is lost during adolescence and that adult women utilize dental health care to a greater degree than men. PMID:26106416

  2. Chemosterilization of male sea lampreys (Petromyzon marinus) does not affect sex pheromone release

    USGS Publications Warehouse

    Siefkes, Michael J.; Bergstedt, Roger A.; Twohey, Michael B.; Li, Weiming

    2003-01-01

    Release of males sterilized by injection with bisazir is an important experimental technique in management of sea lamprey (Petromyzon marinus), an invasive, nuisance species in the Laurentian Great Lakes. Sea lampreys are semelparous and sterilization can theoretically eliminate a male's reproductive capacity and, if the ability to obtain mates is not affected, waste the sex products of females spawning with him. It has been demonstrated that spermiating males release a sex pheromone that attracts ovulating females. We demonstrated that sterilized, spermiating males also released the pheromone and attracted ovulating females. In a two-choice maze, ovulating females increased searching behavior and spent more time in the side of the maze containing chemical stimuli from sterilized, spermiating males. This attraction response was also observed in spawning stream experiments. Also, electro-olfactograms showed that female olfactory organs were equally sensitive to chemical stimuli from sterilized and nonsterilized, spermiating males. Finally, fast atom bombardment mass spectrometry showed that extracts from water conditioned with sterilized and nonsterilized, spermiating males contained the same pheromonal molecule at similar levels. We concluded that injection of bisazir did not affect the efficacy of sex pheromone in sterilized males.

  3. The weaker sex? The propensity for male-biased piglet mortality.

    PubMed

    Baxter, Emma M; Jarvis, Susan; Palarea-Albaladejo, Javier; Edwards, Sandra A

    2012-01-01

    For the most part solutions to farm animal welfare issues, such as piglet mortality, are likely to lie within the scientific disciplines of environmental design and genetic selection, however understanding the ecological basis of some of the complex dynamics observed between parent and offspring could make a valuable contribution. One interesting, and often discussed, aspect of mortality is the propensity for it to be sex-biased. This study investigated whether known physiological and behavioural indicators of piglet survival differed between the sexes and whether life history strategies (often reported in wild or feral populations) relating to parental investment were being displayed in a domestic population of pigs. Sex ratio (proportion of males (males/males+females)) at birth was 0.54 and sex allocation (maternal investment measured as piglet birth weight/litter weight) was statistically significantly male-biased at 0.55 (t(35) = 2.51 P = 0.017), suggesting that sows invested more in sons than daughters during gestation. Despite this investment in birth weight, a known survival indicator, total pre-weaning male mortality was statistically significantly higher than female mortality (12% vs. 7% respectively z = 2.06 P = 0.040). Males tended to suffer from crushing by the sow more than females and statistically significantly more males died from disease-related causes. Although males were born on average heavier, with higher body mass index and ponderal index, these differences were not sustained. In addition male piglets showed impaired thermoregulation compared to females. These results suggest male-biased mortality exists despite greater initial maternal investment, and therefore reflects the greater susceptibility of this sex to causal mortality factors. Life history strategies are being displayed by a domestic population of pigs with sows in this study displaying a form of parental optimism by allocating greater resources at birth to males and

  4. The Weaker Sex? The Propensity for Male-Biased Piglet Mortality

    PubMed Central

    Baxter, Emma M.; Jarvis, Susan; Palarea-Albaladejo, Javier; Edwards, Sandra A.

    2012-01-01

    For the most part solutions to farm animal welfare issues, such as piglet mortality, are likely to lie within the scientific disciplines of environmental design and genetic selection, however understanding the ecological basis of some of the complex dynamics observed between parent and offspring could make a valuable contribution. One interesting, and often discussed, aspect of mortality is the propensity for it to be sex-biased. This study investigated whether known physiological and behavioural indicators of piglet survival differed between the sexes and whether life history strategies (often reported in wild or feral populations) relating to parental investment were being displayed in a domestic population of pigs. Sex ratio (proportion of males (males/males+females)) at birth was 0.54 and sex allocation (maternal investment measured as piglet birth weight/litter weight) was statistically significantly male-biased at 0.55 (t35 = 2.51 P = 0.017), suggesting that sows invested more in sons than daughters during gestation. Despite this investment in birth weight, a known survival indicator, total pre-weaning male mortality was statistically significantly higher than female mortality (12% vs. 7% respectively z = 2.06 P = 0.040). Males tended to suffer from crushing by the sow more than females and statistically significantly more males died from disease-related causes. Although males were born on average heavier, with higher body mass index and ponderal index, these differences were not sustained. In addition male piglets showed impaired thermoregulation compared to females. These results suggest male-biased mortality exists despite greater initial maternal investment, and therefore reflects the greater susceptibility of this sex to causal mortality factors. Life history strategies are being displayed by a domestic population of pigs with sows in this study displaying a form of parental optimism by allocating greater resources at birth to males and

  5. Identification of a sex attractant pheromone for male winterform pear psylla, Cacopsylla pyricola.

    PubMed

    Guédot, Christelle; Millar, Jocelyn G; Horton, David R; Landolt, Peter J

    2009-12-01

    Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), a major economic pest of pears, uses a female-produced sex attractant pheromone. We compared the chemical profiles obtained from cuticular extracts of diapausing and post-diapause winterform males and females to isolate and identify the pheromone. Post-diapause females produced significantly more of the cuticular hydrocarbon, 13-methylheptacosane, than post-diapause males and diapausing females. In olfactometer assays, conspecific males were attracted to synthetic racemic 13-methylheptacosane, whereas females were not, indicating that the behavioral response to this chemical is sex-specific. Furthermore, 13-methylheptacosane was as attractive to males as a cuticular extract of females, suggesting that this chemical was largely responsible for the female attractiveness. A field study showed that males but not females were attracted to 13-methylheptacosane, confirming the olfactometer results. This study provides evidence that 13-methylheptacosane is a sex attractant pheromone for C. pyricola winterform males. This is the first identification of a sex pheromone in the Psylloidea. Our results open the path to developing monitoring tools and possibly new strategies for integrated pest management of this insect. PMID:20063206

  6. A review of bufflehead sex and age criteria with notes on weights

    USGS Publications Warehouse

    Henny, C.J.; Carter, J.L.; Carter, Barbara J.

    1981-01-01

    Summary: Buftleheads Bucephala albeola were collected along the Oregon coast during the hunting season. Birds were first sexed and aged upon cloacal and internal characteristics. Results were then compared with data derived from wing plumage. A small change was made in Carney's (1964) wing plumage key to improve its accuracy. Although only a few studies have been made of Bufflehead weights, it seems that in at least several of these, some immature males have been included in the female category. This mistake has probably resulted from the extremely small penis in the immatures. The foot web length shows potential as a simple sexing criterion during the fall and winter for immatures which are the most difficult to sex under field conditions.

  7. Age of sex-determining mechanisms in vertebrates.

    PubMed

    WITSCHI, E

    1959-08-14

    Certain characteristic patterns of physiologic sex determination are not causally linked with types of genic and chromosomal constitution (XX-XY or ZW-ZZ). The observed widespread but not universal parallelism in the distribution of genetic and physiologic patterns among vertebrate groups expresses genealogic relationship. On the basis of this interpretation one may estimate the approximate evolutionary age of the mechanism of genetic sex determination. It is concluded that in all tetrapod vertebrates these mechanisms originated during the Jurassic period. Environmental conditions seem to affect the progress of this evolution. PMID:13675759

  8. Sex Reassignment Surgery in the Female-to-Male Transsexual

    PubMed Central

    Monstrey, Stan J.; Ceulemans, Peter; Hoebeke, Piet

    2011-01-01

    In female-to-male transsexuals, the operative procedures are usually performed in different stages: first the subcutaneous mastectomy which is often combined with a hysterectomy-ovarectomy (endoscopically assisted). The next operative procedure consists of the genital transformation and includes a vaginectomy, a reconstruction of the horizontal part of the urethra, a scrotoplasty and a penile reconstruction usually with a radial forearm flap (or an alternative). After about one year, penile (erection) prosthesis and testicular prostheses can be implanted when sensation has returned to the tip of the penis. The authors provide a state-of-the-art overview of the different gender reassignment surgery procedures that can be performed in a female-to-male transsexual. PMID:22851915

  9. Brief Report: Parental Age and the Sex Ratio in Autism

    ERIC Educational Resources Information Center

    Anello, Alene; Reichenberg, Abraham; Luo, Xiaodong; Schmeidler, James; Hollander, Eric; Smith, Christopher J.; Puleo, Connor M.; Kryzak, Lauren A.; Silverman, Jeremy M.

    2009-01-01

    The male-to-female (M:F) ratio for autism spectrum disorders (ASD), typically about 4:1, appears to decrease with increasing paternal age, but this relationship has not been systematically tested. With 393 ASD cases from families with two or more ASD cases, we categorized paternal age into five age groups (less than 30, 30-34, 35-39, 40-44, 45+)…

  10. Age and sex suicide rates in the Eastern Mediterranean Region based on global burden of disease estimates for 2000.

    PubMed

    Rezaeian, M

    2007-01-01

    Suicide was estimated to be the 25th leading cause of death in the WHO Eastern Mediterranean Region in the year 2000. Using data from the WHO global burden of disease project, estimated rates of suicidal deaths were plotted for different sex and age groups. Overall rates of suicide were higher in females than males in age groups 5-14 and 15-29 years. The peak age for suicides among females was 15-29 years (8.6 per 100,000) and for males 60+ years (100,000). As a proportion of all deaths due to injury, suicides were substantially higher in females than males. Females in high-income countries had the lowest rates of suicide in all age groups and males in high-income countries had a lower rate than males in low- and middle-income countries. PMID:17955778

  11. Age and Sex Effects on Corpus Callosum Morphology Across the Lifespan

    PubMed Central

    Prendergast, Daniel; Ardekani, Babak; Ikuta, Toshikazu; John, Majnu; Peters, Bart; DeRosse, Pamela; Wellington, Robin; Malhotra, Anil K.; Szeszko, Philip R.

    2015-01-01

    The corpus callosum (CC) is the largest inter-hemispheric white matter tract in the human brain, and is characterized by pronounced differences in morphology among individuals. There are limited data, however, regarding typical development, sex differences, and the neuropsychological correlates of individual differences within CC subregions. Magnetic resonance (MR) imaging exams were collected in a large cohort (N = 305) of healthy individuals (ages 8 to 68). We used a highly reliable program to automatically identify the mid-sagittal plane and obtain CC subregion measures according to approaches described by Witelson (1989) and Hampel (1998) and a measure of whole CC shape (i.e., circularity). CC measurement parameters, including area, perimeter, length, circularity and CC subregion area values were generally characterized by inverted U-shaped curves across the observed age range. Peak values for CC subregions were observed between ages 32 and 45, and descriptive linear correlations were consistent with sharper area changes in development. We also observed differing age-associated changes across the lifespan between males and females in the CC subregion corresponding to the genu (Witelson’s subregion 2), as well as CC circularity. Mediation analysis using path modeling indicated that genu area mediated the relationship between age and processing speed for females, and the relationship between age and visual learning and executive functioning for males. Taken together, our findings implicate sex differences in CC morphology across the lifespan that are localized to the genu, which appear to mediate neuropsychological functions. PMID:25833103

  12. Influence of sex, smoking and age on human hprt mutation frequencies and spectra.

    PubMed Central

    Curry, J; Karnaoukhova, L; Guenette, G C; Glickman, B W

    1999-01-01

    Examination of the literature for hprt mutant frequencies from peripheral T cells yielded data from 1194 human subjects. Relationships between mutant frequency, age, sex, and smoking were examined, and the kinetics were described. Mutant frequency increases rapidly with age until about age 15. Afterward, the rate of increase falls such that after age 53, the hprt mutant frequency is largely stabilized. Sex had no effect on mutant frequency. Cigarette smoking increased mean mutant frequency compared to nonsmokers, but did not alter age vs. mutant frequency relationships. An hprt in vivo mutant database containing 795 human hprt mutants from 342 individuals was prepared. No difference in mutational spectra was observed comparing smokers to nonsmokers, confirming previous reports. Sex affected the frequency of deletions (>1 bp) that are recovered more than twice as frequently in females (P = 0. 008) compared to males. There is no indication of a significant shift in mutational spectra with age for individuals older than 19 yr, with the exception of A:T --> C:G transversions. These events are recovered more frequently in older individuals. PMID:10388825

  13. Clover root exudate produces male-biased sex ratios and accelerates male metamorphic timing in wood frogs

    PubMed Central

    Lambert, Max R.

    2015-01-01

    In amphibians, abnormal metamorph sex ratios and sexual development have almost exclusively been considered in response to synthetic compounds like pesticides or pharmaceuticals. However, endocrine-active plant chemicals (i.e. phytoestrogens) are commonly found in agricultural and urban waterways hosting frog populations with deviant sexual development. Yet the effects of these compounds on amphibian development remain predominantly unexplored. Legumes, like clover, are common in agricultural fields and urban yards and exude phytoestrogen mixtures from their roots. These root exudates serve important ecological functions and may also be a source of phytoestrogens in waterways. I show that clover root exudate produces male-biased sex ratios and accelerates male metamorphosis relative to females in low and intermediate doses of root exudate. My results indicate that root exudates are a potential source of contaminants impacting vertebrate development and that humans may be cultivating sexual abnormalities in wildlife by actively managing certain plant species. PMID:27019728

  14. Clover root exudate produces male-biased sex ratios and accelerates male metamorphic timing in wood frogs.

    PubMed

    Lambert, Max R

    2015-12-01

    In amphibians, abnormal metamorph sex ratios and sexual development have almost exclusively been considered in response to synthetic compounds like pesticides or pharmaceuticals. However, endocrine-active plant chemicals (i.e. phytoestrogens) are commonly found in agricultural and urban waterways hosting frog populations with deviant sexual development. Yet the effects of these compounds on amphibian development remain predominantly unexplored. Legumes, like clover, are common in agricultural fields and urban yards and exude phytoestrogen mixtures from their roots. These root exudates serve important ecological functions and may also be a source of phytoestrogens in waterways. I show that clover root exudate produces male-biased sex ratios and accelerates male metamorphosis relative to females in low and intermediate doses of root exudate. My results indicate that root exudates are a potential source of contaminants impacting vertebrate development and that humans may be cultivating sexual abnormalities in wildlife by actively managing certain plant species. PMID:27019728

  15. The role of non-coding RNAs in male sex determination and differentiation.

    PubMed

    Rastetter, Raphael H; Smith, Craig A; Wilhelm, Dagmar

    2015-09-01

    A complex network of gene regulation and interaction drives male sex determination and differentiation. While many important protein-coding genes that are necessary for proper male development have been identified, many disorders in human sex development are still unexplained at the molecular level. This suggests that key factors and regulatory mechanisms are still unknown. In recent years, extensive data have shown that different classes of non-coding RNAs (ncRNAs) play a role in almost all developmental and physiological pathways. Here we review what is known about their role in male sex determination and differentiation not only in mammals, but also other species. While for some processes a key role for ncRNA has been identified, we are still far from having a complete picture. PMID:25995439

  16. AIDS knowledge, risk behaviors, and factors related to condom use among male commercial sex workers and male tourist clients in Bali, Indonesia.

    PubMed

    Ford, K; Wirawan, D N; Fajans, P; Thorpe, L

    1995-07-01

    Interviews conducted in 1992-93 with 80 male commercial sex workers in Bali, Indonesia, and 100 of their tourist clients revealed low levels of accurate knowledge about acquired immunodeficiency syndrome (AIDS) and widespread high-risk sexual behaviors. Although most male sex workers were aware of AIDS, 30% did not know that healthy-appearing persons could be infected. The mean number of clients in the week preceding the interview was 2.8 (range, 0-12); 61% had engaged in anal intercourse in that period. Condom use with clients averaged 48% for receptive anal intercourse, 55% for insertive anal intercourse, and 14-17% for oral intercourse; these rates were 19%, 33%, and 0%, respectively, for unpaid partners. Only 30% of clients serviced by male prostitutes insisted on condom use. Factors related to condom use with commercial clients were condom beliefs, self-efficacy, perceived susceptibility to infection, and knowledge of sexually transmitted diseases. The tourist clients, 60% of whom were from Europe and 25% from Australia, were significantly older (mean age, 38.4 years) than the sex workers. 64% reported a history of STD infection, primarily gonorrhea. In the week before the interview, clients had an average of 1.7 paid and 0.3 unpaid partners and 53% engaged in anal intercourse. Condom use was 75% for receptive and 69% for insertive anal intercourse. Although 87% of tourists brought condoms to Bali, only 62% knew of a local source. Factors related to condom use with a commercial sex worker were condom beliefs and self-efficacy. PMID:7546421

  17. Methods of suicide by age: sex and race differences among the young and old.

    PubMed

    McIntosh, J L; Santos, J F

    The elderly have the highest suicide rate in the United States. In partial explanation of this finding, a common statement in the suicide literature is that older persons tend to use more drastic and effective methods of suicide. However, little, if any, data have been presented in defense of this explanation. In order to investigate the validity of this contention, annual official statistics for specific methods of suicide (firearms, hanging, poisons) by age for different sex and racial groups (whites, blacks, nonwhites excluding black) were examined from 1960 to 1978. Comparisons among the age-sex-race groups, along with trends over time and differences in the methods employed, were noted. For white males, blacks of both sexes, and nonwhites excluding black females, the findings confirmed the use of more violent methods by the elderly than by the young in terms of the proportion of suicides by firearms and/or hanging. Less support and, in fact, opposite results for method-related age differences were obtained for white females and nonwhites excluding black males. Another general finding was an increase in the use of firearms for most of the groups studied. The need for data for specific groups within the nonwhite category excluding blacks is apparent both from the available literature and from the present findings. Possible explanations and implications of the observed results are discussed. PMID:3830918

  18. Being male or living with a female: fear for partners by sex and sexual orientation.

    PubMed

    Drakulich, Kevin M; Rose, Kristin

    2013-06-01

    While substantial research attention has been paid to the disproportionately high levels of fear of crime among women relative to men, less attention has been paid to the apparent mirror of this: that men have disproportionately more concern for female partners than women do for male partners. The work that does exist on fear for partners has focused exclusively on different-sex partnerships. The present article proposes and explores several explanations for sex differences in fear for partners among different-sex as well as same-sex partnerships. The analysis uses a sample of persons who live with a partner (155 in same-sex and 2,817 in different-sex partnerships) from a Seattle survey that includes measures of altruistic fear, as well as measures of personal, familial, sexual assault, and sexual identity bias victimizations. Results suggest that female partners inspire more fear regardless of the sex of the respondents, that sex differences persist even after perceptions of danger are accounted for, and that personal fears and fears for children are positively associated with fears for partners and do not explain sex differences in such fears. These results are more consistent with explanations rooted in gendered perceptions of vulnerability and the shadow of sexual assault than explanations rooted in the differential gender socialization of men as protectors or of a limited capacity for fear. PMID:23277470

  19. Male and female mate choice affects offspring quality in a sex-role-reversed pipefish.

    PubMed

    Sandvik, M; Rosenqvist, G; Berglund, A

    2000-11-01

    Where both sexes invest substantially in offspring, both females and males should discriminate between potential partners when choosing mates. The degree of choosiness should relate to the costs of choice and to the potential benefits to be gained. We measured offspring quality from experimentally staged matings with preferred and non-preferred partners in a sex-role-reversed pipefish, Syngnathus typhle L. Here, a substantial male investment in offspring results in a lower potential reproductive rate in males than in females, and access to males limits female reproductive success rather than vice versa. Thus, males are choosier than females and females compete more intensely over mates than do males. Broods from preferred matings were superior at escaping predation, when either males or females were allowed to choose a partner. However, only 'choosing' females benefited in terms of faster-growing offspring. Our results have important implications for mate-choice research: here we show that even the more competitive and less choosy sex may contribute significantly to sexual selection through mate choice. PMID:11413626

  20. Age- and Sex-Specific Mortality Associated With the 1918–1919 Influenza Pandemic in Kentucky

    PubMed Central

    Viboud, Cécile; Eisenstein, Jana; Reid, Ann H.; Janczewski, Thomas A.; Morens, David M.; Taubenberger, Jeffery K.

    2013-01-01

    Background. The reasons for the unusual age-specific mortality patterns of the 1918–1919 influenza pandemic remain unknown. Here we characterize pandemic-related mortality by single year of age in a unique statewide Kentucky data set and explore breakpoints in the age curves. Methods. Individual death certificates from Kentucky during 1911–1919 were abstracted by medically trained personnel. Pandemic-associated excess mortality rates were calculated by subtracting observed rates during pandemic months from rates in previous years, separately for each single year of age and by sex. Results. The age profile of excess mortality risk in fall 1918 was characterized by a maximum among infants, a minimum at ages 9–10 years, a maximum at ages 24–26 years, and a second minimum at ages 56–59 years. The excess mortality risk in young adults had been greatly attenuated by winter 1919. The age breakpoints of mortality risk did not differ between males and females. Conclusions. The observed mortality breakpoints in male and female cohorts born during 1859–1862, 1892–1894, and 1908–1909 did not coincide with known dates of historical pandemics. The atypical age mortality patterns of the 1918–1919 pandemic cannot be explained by military crowding, war-related factors, or prior immunity alone and likely result from a combination of unknown factors. PMID:23230061

  1. Sex-dependent dominance at a single locus maintains variation in age at maturity in salmon.

    PubMed

    Barson, Nicola J; Aykanat, Tutku; Hindar, Kjetil; Baranski, Matthew; Bolstad, Geir H; Fiske, Peder; Jacq, Céleste; Jensen, Arne J; Johnston, Susan E; Karlsson, Sten; Kent, Matthew; Moen, Thomas; Niemelä, Eero; Nome, Torfinn; Næsje, Tor F; Orell, Panu; Romakkaniemi, Atso; Sægrov, Harald; Urdal, Kurt; Erkinaro, Jaakko; Lien, Sigbjørn; Primmer, Craig R

    2015-12-17

    Males and females share many traits that have a common genetic basis; however, selection on these traits often differs between the sexes, leading to sexual conflict. Under such sexual antagonism, theory predicts the evolution of genetic architectures that resolve this sexual conflict. Yet, despite intense theoretical and empirical interest, the specific loci underlying sexually antagonistic phenotypes have rarely been identified, limiting our understanding of how sexual conflict impacts genome evolution and the maintenance of genetic diversity. Here we identify a large effect locus controlling age at maturity in Atlantic salmon (Salmo salar), an important fitness trait in which selection favours earlier maturation in males than females, and show it is a clear example of sex-dependent dominance that reduces intralocus sexual conflict and maintains adaptive variation in wild populations. Using high-density single nucleotide polymorphism data across 57 wild populations and whole genome re-sequencing, we find that the vestigial-like family member 3 gene (VGLL3) exhibits sex-dependent dominance in salmon, promoting earlier and later maturation in males and females, respectively. VGLL3, an adiposity regulator associated with size and age at maturity in humans, explained 39% of phenotypic variation, an unexpectedly large proportion for what is usually considered a highly polygenic trait. Such large effects are predicted under balancing selection from either sexually antagonistic or spatially varying selection. Our results provide the first empirical example of dominance reversal allowing greater optimization of phenotypes within each sex, contributing to the resolution of sexual conflict in a major and widespread evolutionary trade-off between age and size at maturity. They also provide key empirical evidence for how variation in reproductive strategies can be maintained over large geographical scales. We anticipate these findings will have a substantial impact on

  2. A cause for concern: male couples' sexual agreements and their use of substances with sex.

    PubMed

    Mitchell, Jason W; Boyd, Carol; McCabe, Sean; Stephenson, Rob

    2014-07-01

    Substance use is strongly associated with HIV risk among gay men. Many gay couples establish sexual agreements. However, little is known about gay couples' use of substances with sex, and whether substance use is associated with couples' agreements. The present study assessed whether gay couples' use of substances with sex was associated with their establishment of, type of, and adherence to, a sexual agreement. Dyadic data from 275 HIV-negative US gay couples were collected online in a nation-wide, cross-sectional study, and analyzed at the couple-level. Findings revealed that couples with an established agreement, and a recently broken agreement, were more likely to have used amyl nitrates and marijuana with sex within their relationship. This same trend was also noted, but for alcohol use with sex outside of couples' relationships. Further research is urgently needed to examine the fluidity of HIV-negative gay male couples' sexual agreements and substance use with sex. PMID:24584415

  3. A cause for concern: Male couples' sexual agreements and their use of substances with sex

    PubMed Central

    Mitchell, Jason W.; Boyd, Carol; McCabe, Sean; Stephenson, Rob

    2015-01-01

    Substance use is strongly associated with HIV risk among gay men. Many gay couples establish sexual agreements. However, little is known about gay couples’ use of substances with sex, and whether substance use is associated with couples’ agreements. The present study assessed whether gay couples’ use of substances with sex was associated with their establishment of, type of, and adherence to, a sexual agreement. Dyadic data from 275 HIV-negative US gay couples were collected online in a nation-wide, cross-sectional study, and analyzed at the couple-level. Findings revealed that couples with an established agreement, and a recently broken agreement, were more likely to have used amyl nitrates and marijuana with sex within their relationship. This same trend was also noted, but for alcohol use with sex outside of couples’ relationships. Further research is urgently needed to examine the fluidity of HIV-negative gay male couples’ sexual agreements and substance use with sex. PMID:24584415

  4. Multicolor FISH studies of male non-disjunction: Evidence for a paternal age effect

    SciTech Connect

    Griffin, D.K.; Millie, E.A.; Sheean, L.A.

    1994-09-01

    Approximately 5-10% of autosomal trisomies and the majority of sex chromosome aneuploidies are paternally derived, thus paternal non-disjunction is an important contributor to human chromosomal syndromes. We have been using multicolor FISH to screen for aneuploidy in sperm of normal males and to determine whether there is, among individuals or among chromosomes, variation in the likelihood of non-disjunction. Our initial studies based on analysis of 5000 sperm scored per chromosome in nine males identified significant differences in disomy rates for chromosomes 16, 18 and the sex chromosomes. We have now extended those analyses to a new series of 10 donors aged 22 to 45 to confirm or refute our observations of chromosome-specific differences in rates of disomy; to determine if the size of the centromeric (alpha satellite) sequences is related to non-disjunction frequency; and to determine if there is a paternal as well as a maternal age effect on non-disjunction. For these studies, we have used 3 color FISH for chromosomes 18 and the X and Y chromosomes to now score {approximately}20,000 sperm for each of 10 new donors. Our results provide little evidence for an effect of the size of the Y chromosome centromere on the frequency of sex chromosome disomy. However, we have found considerable variation in rates of disomy among individuals and have confirmed significant differences among chromosomes in the likelihood of non-disjunction; i.e., the rate of non-disjunction of the sex chromosomes is 3.5 -4 times greater than that of chromosome 18 and meiosis II errors are significantly more likely for the Y chromosome than for the X chromosome. Specifically, we have identified increases in the frequency of disomy 18 and both meiosis I (XY) and meiosis II (XX and YY) sex chromosome disomy although the effect is only significant for total sex chromosome disomy.

  5. Sex-differential placentation immunological interactions between male conceptus and gravida during normal pregnancy.

    PubMed

    Vernier, M C

    1975-01-01

    7,773 placentae of newborns were analyzed in order to test a hypothesis of specific immunological concepto-maternal interactions due to maleness and occurring during normal pregnancy. An association between placental weight of newborn male and the sex of conceptuses of previous pregnancies was found which supports the hypothesis. No such an association was found for female newborn. The confirmation of these results could open new avenues in the study of sex-differential survival of the conceptus throughout gestation. PMID:1148342

  6. Sex Differences in Participation, Performance, and Age of Ultramarathon Runners.

    PubMed

    Senefeld, Jonathon; Smith, Carolyn; Hunter, Sandra K

    2016-07-01

    The sex difference in marathon running is increased with lower participation of women than men, but whether this occurs for ultramarathon running is not known. The study purpose was to determine whether the sex difference in performance widens among lower-placed runners and the association between the sex difference in running speed and participation rates. The top-10 ultramarathon running times, age at performance date, and the number of men and women finishers were analyzed from 20 races (45-160 km) in the US Track and Field Ultra Running Grand Prix. Men were faster than women for all events (18.7% ± 5.8%, P < .001). The sex difference in speed was the least for 100 km (14.9% ± 4.2%) and greatest for 45-50 km (19.3% ± 5.8%). The top-10 men were younger than the top-10 women (37.7 ± 3.2 and 39.0 ± 3.1 y, respectively, P < .001). The sex difference in speed increased with finishing place (1st place 15.6% ± 6.6% vs 10th 20.8% ± 5.6%, P < .001). Association analysis showed that the sex difference in speed was largest when there were fewer women than men finishers in a race; the strength of the association was greatest for the 80-km distance and least for the 160-km. Lower participation rates of women than men in the lower-distance ultramarathons and less depth among lower-placed women runners inflate the sex difference in ultramarathon performance. PMID:26561864

  7. [Mortality evolution in the Czech Socialist Republic, by sex and age in 1950-1984].

    PubMed

    Rychtarikova, J

    1987-01-01

    Postwar mortality evolution in the Czech Socialist Republic has run through 2 different stages with the turning point being 1960. Since about the beginning of the 1960s, the mortality level in the Czech Socialist Republic has quickly declined for both sexs and in each age category. The rate of decline has slowed with increasing age. Since the 1960s, the mortality of the older population has ceased to decline or has worsened; with men, this phenomenon spread even as low as 40 years old. Infant and child mortality, male mortality under 40 years of age, and female mortality under 50 years of age positively contributed to a longer life span, except between 1960 and 1970. The present mortality situation in the Czech Socialist Republic is the result of the unfavorable developments of the last 20 years, especially in the decade 1960-1970. The present age structure of mortality is characterized by higher infant mortality, higher male mortality above 40 years of age, and higher female mortality at 50-55 years of age. A certain improvement observed in the last few years is relative, as the mortality of the male population over 30 is the same today as it was 35 years ago and the mortality of the female population is the same as it was in the mid-1960s. PMID:12314972

  8. Behavioral and physiological female responses to male sex ratio bias in a pond-breeding amphibian

    PubMed Central

    2012-01-01

    Introduction The phenomenon of sexual conflict has been well documented, and in populations with biased operational sex ratios the consequences for the rarer sex can be severe. Females are typically a limited resource and males often evolve aggressive mating behaviors, which can improve individual fitness for the male while negatively impacting female condition and fitness. In response, females can adjust their behavior to minimize exposure to aggressive mating tactics or minimize the costs of mating harassment. While male-male competition is common in amphibian mating systems, little is known about the consequences or responses of females. The red-spotted newt (Notophthalmus viridescens) is a common pond-breeding amphibian with a complex, well-studied mating system where males aggressively court females. Breeding populations across much of its range have male-biased sex ratios and we predicted that female newts would have behavioral mechanisms to mitigate mating pressure from males. We conducted four experiments examining the costs and behavioral responses of female N. viridescens exposed to a male-biased environment. Results In field enclosures, we found that female newts exposed to a male-biased environment during the five-month breeding season ended with lower body condition compared to those in a female-biased environment. Shorter-term exposure to a male-biased environment for five weeks caused a decrease in circulating total leukocyte and lymphocyte abundance in blood, which suggests females experienced physiological stress. In behavioral experiments, we found that females were more agitated in the presence of male chemical cues and females in a male-biased environment spent more time in refuge than those in a female-biased environment. Conclusions Our results indicate that male-biased conditions can incur costs to females of decreased condition and potentially increased risk of infection. However, we found that females can also alter their behavior and

  9. Mating system and sex ratios of a pollinating fig wasp with dispersing males.

    PubMed Central

    Greeff, Jaco M

    2002-01-01

    Recent studies have used sex ratios to quantify the mating systems of organisms, the argument behind it being that more female-biased sex ratios are an indication of higher local mate competition, which goes hand-in-hand with higher levels of inbreeding. Although qualitative tests of the effects of mating systems on sex ratios abound, there is a dearth of studies that quantify both the mating system and the sex ratio. I use a colour dimorphism with a simple Mendelian inheritance to quantify the mating system of an unusual fig-pollinating wasp in which males disperse to obtain matings on non-natal mating patches. In qualitative agreement with initial expectations, the sex ratios of single foundresses are found to be higher than those of regular species. However, by quantifying the mating system, it is shown that the initial expectation is incorrect and this species' sex ratio is a poor predictor of its mating system (it underestimates the frequency of sib-mating). The species has a very high variance in sex ratio suggesting that excess males can simply avoid local mate competition (and hence a lowered fitness to their mother) by dispersing to other patches. PMID:12495498

  10. Hypotestosteronaemia in the aging male: should we treat it?

    PubMed

    Christe, Nora; Meier, Christoph A

    2015-01-01

    The term male hypogonadism is defined as the failure to maintain physiological concentrations of testosterone, a physiological quantity of sperm or the combination of both. Aetiologically, androgen deficiency can originate from the testes (primary hypogonadism) or from the hypothalamic-pituitary regulation of the testicular function (secondary hypogonadism). The causes of hypogonadism are very diverse and may be genetically determined (e.g. Klinefelter's syndrome) or acquired (tumours, infections, haemochromatosis). Classical hypogonadism linked to an underlying disease, such as a pituitary tumour, is a distinct indication for androgen substitution. But how about the aging male? It is known that there is a highly variable age-related decline in testosterone levels; whether this represents a variation of normality or has a true disease value requiring therapy has been disputed over more than a decade. The key questions surrounding this debate concern not only the age-dependent threshold for serum testosterone but, more importantly, the risks and benefits of testosterone replacement therapy in the aging male. We searched the literature for randomised controlled trials of testosterone administration in aging males with a size of at least 100 patients and a follow-up of at least 6 months, and identified eight studies. These studies mostly tried to evaluate the effect of testosterone on bone density, muscle strength and body composition, rather than clinically meaningful endpoints. Moreover, these trials have provided evidence for relevant cardiovascular adverse events in elderly men. This supports the need for further studies to define the treatment threshold for testosterone levels in the aging male, as well as with regard to the long-term risks and relevant benefits of testosterone therapy in this population. Until we have more solid data in aging males, testing for testosterone deficiency and testosterone replacement should remain reserved for patients with

  11. The trap of sex in social insects: from the female to the male perspective.

    PubMed

    Beani, Laura; Dessì-Fulgheri, Francesco; Cappa, Federico; Toth, Amy

    2014-10-01

    The phenotype of male Hymenoptera and the peculiar role of males has been neglected and greatly understudied, given the spectacular cooperative behavior of female social insects. In social insects there has been considerable progress in understanding the molecular mechanisms behind haplodiploid sex determination but, beyond that, very little is known concerning the neural, endocrine, and genetic correlates of sexual selection in males. An opportunity is being missed: the male phenotype in Hymenoptera is a natural experiment to compare the drives of natural versus sexual selection. In contrast to females, males do not work, they usually display far from the nest to gain mates, compete among rivals in nuptial flights or for a symbolic territory at leks, and engage in direct or ritualized conflicts. By comparing the available data on male paper wasps with studies on other social Hymenoptera, we summarize what we currently know about the physical, hormonal, neural and behavioral traits in a model system appropriate to examine current paradigms on sexual selection. Here we review male behavior in social Hymenoptera beyond sex stereotypes: the subtle role of "drones" in the colony, the lack of armaments and ornaments, the explosive mating crowds, the "endurance" race, the cognitive bases of the "choosy" male and his immune defense. Social insect males are not just simple-minded mating machines, they are shaped, constrained and perhaps trapped by sexual selection. PMID:25280909

  12. Kcne4 deletion sex- and age-specifically impairs cardiac repolarization in mice.

    PubMed

    Crump, Shawn M; Hu, Zhaoyang; Kant, Ritu; Levy, Daniel I; Goldstein, Steve A N; Abbott, Geoffrey W

    2016-01-01

    Myocardial repolarization capacity varies with sex, age, and pathology; the molecular basis for this variation is incompletely understood. Here, we show that the transcript for KCNE4, a voltage-gated potassium (Kv) channel β subunit associated with human atrial fibrillation, was 8-fold more highly expressed in the male left ventricle compared with females in young adult C57BL/6 mice (P < 0.05). Similarly, Kv current density was 25% greater in ventricular myocytes from young adult males (P < 0.05). Germ-line Kcne4 deletion eliminated the sex-specific Kv current disparity by diminishing ventricular fast transient outward current (Ito,f) and slowly activating K(+) current (IK,slow1). Kcne4 deletion also reduced Kv currents in male mouse atrial myocytes, by >45% (P < 0.001). As we previously found for Kv4.2 (which generates mouse Ito,f), heterologously expressed KCNE4 functionally regulated Kv1.5 (the Kv α subunit that generates IKslow1 in mice). Of note, in postmenopausal female mice, ventricular repolarization was impaired by Kcne4 deletion, and ventricular Kcne4 expression increased to match that of males. Moreover, castration diminished male ventricular Kcne4 expression 2.8-fold, whereas 5α-dihydrotestosterone (DHT) implants in castrated mice increased Kcne4 expression >3-fold (P = 0.01) to match noncastrated levels. KCNE4 is thereby shown to be a DHT-regulated determinant of cardiac excitability and a molecular substrate for sex- and age-dependent cardiac arrhythmogenesis. PMID:26399785

  13. Bias in the reporting of sex and age in biomedical research on mouse models.

    PubMed

    Flórez-Vargas, Oscar; Brass, Andy; Karystianis, George; Bramhall, Michael; Stevens, Robert; Cruickshank, Sheena; Nenadic, Goran

    2016-01-01

    In animal-based biomedical research, both the sex and the age of the animals studied affect disease phenotypes by modifying their susceptibility, presentation and response to treatment. The accurate reporting of experimental methods and materials, including the sex and age of animals, is essential so that other researchers can build on the results of such studies. Here we use text mining to study 15,311 research papers in which mice were the focus of the study. We find that the percentage of papers reporting the sex and age of mice has increased over the past two decades: however, only about 50% of the papers published in 2014 reported these two variables. We also compared the quality of reporting in six preclinical research areas and found evidence for different levels of sex-bias in these areas: the strongest male-bias was observed in cardiovascular disease models and the strongest female-bias was found in infectious disease models. These results demonstrate the ability of text mining to contribute to the ongoing debate about the reproducibility of research, and confirm the need to continue efforts to improve the reporting of experimental methods and materials. PMID:26939790

  14. Bias in the reporting of sex and age in biomedical research on mouse models

    PubMed Central

    Flórez-Vargas, Oscar; Brass, Andy; Karystianis, George; Bramhall, Michael; Stevens, Robert; Cruickshank, Sheena; Nenadic, Goran

    2016-01-01

    In animal-based biomedical research, both the sex and the age of the animals studied affect disease phenotypes by modifying their susceptibility, presentation and response to treatment. The accurate reporting of experimental methods and materials, including the sex and age of animals, is essential so that other researchers can build on the results of such studies. Here we use text mining to study 15,311 research papers in which mice were the focus of the study. We find that the percentage of papers reporting the sex and age of mice has increased over the past two decades: however, only about 50% of the papers published in 2014 reported these two variables. We also compared the quality of reporting in six preclinical research areas and found evidence for different levels of sex-bias in these areas: the strongest male-bias was observed in cardiovascular disease models and the strongest female-bias was found in infectious disease models. These results demonstrate the ability of text mining to contribute to the ongoing debate about the reproducibility of research, and confirm the need to continue efforts to improve the reporting of experimental methods and materials. DOI: http://dx.doi.org/10.7554/eLife.13615.001 PMID:26939790

  15. Sex differences in metabolic aging of the brain: insights into female susceptibility to Alzheimer's disease.

    PubMed

    Zhao, Liqin; Mao, Zisu; Woody, Sarah K; Brinton, Roberta D

    2016-06-01

    Despite recent advances in the understanding of clinical aspects of sex differences in Alzheimer's disease (AD), the underlying mechanisms, for instance, how sex modifies AD risk and why the female brain is more susceptible to AD, are not clear. The purpose of this study is to elucidate sex disparities in brain aging profiles focusing on 2 major areas-energy and amyloid metabolism-that are most significantly affected in preclinical development of AD. Total RNA isolated from hippocampal tissues of both female and male 129/C57BL/6 mice at ages of 6, 9, 12, or 15 months were comparatively analyzed by custom-designed Taqman low-density arrays for quantitative real-time polymerase chain reaction detection of a total of 182 genes involved in a broad spectrum of biological processes modulating energy production and amyloid homeostasis. Gene expression profiles revealed substantial differences in the trajectory of aging changes between female and male brains. In female brains, 44.2% of genes were significantly changed from 6 months to 9 months and two-thirds showed downregulation. In contrast, in male brains, only 5.4% of genes were significantly altered at this age transition. Subsequent changes in female brains were at a much smaller magnitude, including 10.9% from 9 months to 12 months and 6.1% from 12 months to 15 months. In male brains, most changes occurred from 12 months to 15 months and the majority were upregulated. Furthermore, gene network analysis revealed that clusterin appeared to serve as a link between the overall decreased bioenergetic metabolism and increased amyloid dyshomeostasis associated with the earliest transition in female brains. Together, results from this study indicate that: (1) female and male brains follow profoundly dissimilar trajectories as they age; (2) female brains undergo age-related changes much earlier than male brains; (3) early changes in female brains signal the onset of a hypometabolic phenotype at risk for AD. These

  16. Knee joint examinations by magnetic resonance imaging: The correlation of pathology, age, and sex

    PubMed Central

    Avcu, Serhat; Altun, Ersan; Akpinar, Ihsan; Bulut, Mehmet Deniz; Eresov, Kemal; Biren, Tugrul

    2010-01-01

    Aims: The aim of our study was to investigate the incidence and coexistence of multiple knee joint pathologies and the distribution of knee joint pathologies according to age and sex. Patients and Methods: A retrospective analysis was performed using the clinical data of patients evaluated with magnetic resonance imaging (MRI) of the knee joint. Data from 308 patients examined between August 2002 and July 2003 were included into this study. A Pearson correlation analysis was performed to examine the relationship between the pathological findings and the age and sex of the patients. Results: The ages of the patients ranged between 1 and 74 years (mean: 43.3 years). Age was significantly correlated with meniscal degeneration and tears, medial collateral ligament degeneration, parameniscal cyst, and chondromalacia patellae. There was a significant correlation between male gender and anterior cruciate ligament injury. Meniscal injury was significantly correlated with bursitis, as well as medial collateral ligament injury. Bone bruise was significantly correlated with medial collateral ligament injury, lateral collateral ligament injury, Baker's cyst, and anterior cruciate ligament injury. Chondromalacia patellae was significantly correlated with anterior cruciate ligament injury, patellae alta, and osteochondral lesion. Bursitis (in 53.2% of the patients) followed by grade-II meniscal degeneration (in 43% of the patients) were the most common knee pathologies observed by MRI. Conclusions: MRI findings of select knee pathologies are significantly correlated with each other and the age and sex of the patient. PMID:22624141

  17. Suicide mortality trends by sex, age and method in Taiwan, 1971–2005

    PubMed Central

    Lin, Jin-Jia; Lu, Tsung-Hsueh

    2008-01-01

    Background Method-specific suicide trends varied across countries, and studies of the trends in different countries can contribute to the understanding of the epidemiology of suicide. The purpose of this study was to examine the changes in suicide trends by sex, age and method in the years 1971 to 2005 in Taiwan. Methods Mortality data files of suicide and undetermined deaths for the years 1971–2005 were obtained for analyses. Age-, sex- and method-specific suicide rates were calculated by four age groups (15–24, 25–44, 45–64 and 65 and above) and five suicide methods (solids/liquids poisoning, other gases poisoning, hanging, jumping, and others). Results Both sexes experienced downward trends from 1971 to 1993, and then an upward trend since 1993. People aged 65 years and above had the highest suicide rates throughout the study periods. However, males aged 25–64 years experienced the steepest increasing trends. As to suicide methods, an annual increase, since 1991, of people jumping from heights to commit suicide, and a marked increase, since 1998, of people completing suicide by poisoning with other gases (mainly charcoal-burning) were observed. Conclusion Suicide by means of charcoal-burning and jumping from heights has become a serious public health problem in Taiwan. Preventive measures to curb these increasing trends are urgently needed. PMID:18179723

  18. Age-dependent female responses to a male ejaculate signal alter demographic opportunities for selection

    PubMed Central

    Fricke, Claudia; Green, Darrell; Mills, Walter E.; Chapman, Tracey

    2013-01-01

    A central tenet of evolutionary explanations for ageing is that the strength of selection wanes with age. However, data on age-specific expression and benefits of sexually selected traits are lacking—particularly for traits subject to sexual conflict. We addressed this by using as a model the responses of Drosophila melanogaster females of different ages to receipt of sex peptide (SP), a seminal fluid protein transferred with sperm during mating. SP can mediate sexual conflict, benefitting males while causing fitness costs in females. Virgin and mated females of all ages showed significantly reduced receptivity in response to SP. However, only young virgin females also showed increased egg laying; hence, there was a narrow demographic window of maximal responses to SP. Males gained significant ‘per mating’ fitness benefits only when mating with young females. The pattern completely reversed in matings with older females, where SP transfer was costly. The overall benefits of SP transfer (hence opportunity for selection) therefore reversed with female age. The data reveal a new example of demographic variation in the strength of selection, with convergence and conflicts of interest between males and ageing females occurring over different facets of responses to a sexually antagonistic trait. PMID:23843383

  19. Age- and sex-associated plasma proteomic changes in growth hormone receptor gene-disrupted mice.

    PubMed

    Ding, Juan; Berryman, Darlene E; Jara, Adam; Kopchick, John J

    2012-08-01

    Growth hormone receptor gene-disrupted (GHR-/-) mice are dwarf, insulin sensitive, and long lived despite being obese. In order to identify characteristics associated with their increased longevity, we studied age-related plasma proteomic changes in these mice. Male and female GHR-/- mice and their littermate controls were followed longitudinally at 8, 16, and 24 months of ages for plasma proteomic analysis. Relative to control littermates, GHR-/- mice had increased levels of apolipoprotein A-4 and retinol-binding protein-4 and decreased levels of apolipoprotein E, haptoglobin, and mannose-binding protein-C. Female GHR-/- mice showed decreased inflammatory cytokines including interleukin-1β and monocyte chemotactic protein-1. Additionally, sex differences were found in specific isoforms of apolipoprotein E, RBP-4, haptoglobin, albumin, and hemoglobin subunit beta. In conclusion, we find plasma proteomic changes in GHR-/- mice that favor a longer life span as well as sex differences indicative of an improved health span in female mice. PMID:22156438

  20. Effects of age and sex on hormonal responses to weightlessness simulation

    NASA Technical Reports Server (NTRS)

    Larochelle, F.; Leach, C.; Vernikos-Danellis, J.

    1982-01-01

    The effects of horizontal bedrest on the excretion of catecholamines, aldosterone, and cortisol by human subjects grouped by age and sex are examined. The responses are assessed by assays of 24-hr urine samples collected throughout the studies. In 36-45-yr-olds, the excretion of epinephrine increases, whereas it decreases in the 46-55- and 56-65-yr-old groups. Norepinephrine excretion decreases (5-27%) in all groups during bedrest. Aldosterone excretion increases in the younger two groups of both males (19 and 6%) and females (47 and 9%). A slight decrease is observed in 56-65-yr-old males (6%), whereas excretion in females is unchanged. Cortisol excretion increases in the youngest groups of both men (12%) and women (13%) but decreases in the 56-65-yr-old groups (6 and 5%). For the two groups of intermediate age (46-55 yr), excretion in females decreases (15%), whereas in males it increases (19%). It is believed that hormone measurements may be of value in explaining variation in stress tolerance due to age and/or sex during space flight.

  1. Treatment of changes on male sex organs with CO2 and Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Wozniak, Jakub; Rzymski, Pawel; Opala, Tomasz; Wilczak, Maciej; Sajdak, Stefan

    2003-10-01

    The aim of our study was to evaluate treatment of changes on male sex organs with CO2 and Nd:YAG lasers. Material consisted of 34 male patients of Diagnostic and Observational Department of Gynecologic and Obstetrical University Hospital in Poznan, Poland treated between 1998 and 2002. Results of treatment with both lasers were similar when comparing therapeutic effect and side effects. No complication was noticed and the observed differences were not statistically significant.

  2. Operational sex ratio and density do not affect directional selection on male sexual ornaments and behavior.

    PubMed

    Head, Megan L; Lindholm, Anna K; Brooks, Robert

    2008-01-01

    Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on male sexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity for sexual selection due to increased sexual coercion experienced by females. How OSR, density, and any resultant changes in the opportunity for sexual selection actually affect selection on male sexual traits is unclear. In this study, we independently manipulated OSR and density in the guppy (Poecilia reticulata) without altering the number of males present. We recorded male and female behavior and used DNA microsatellite data to assign paternity to offspring and estimate male reproductive success. We then used linear selection analyses to examine the effects of OSR and density on directional sexual selection on male behavioral and morphological traits. We found that females were pursued more by males in male-biased treatments, despite no change in individual male behavior. There were no differences in sexual behavior experienced by females or performed by males in relation to density. Neither OSR nor density significantly altered the opportunity for sexual selection. Also, Although there was significant multivariate linear selection operating on males, neither OSR nor density altered the pattern of sexual selection on male traits. Our results suggest that differences in either OSR or density (independent of the number of males present) are unlikely to alter directional evolutionary change in male sexual traits. PMID:18067568

  3. "Aging males" symptoms and general health of adult males: a cross-sectional study.

    PubMed

    Yuen, John W; Ng, Chi-Fai; Chiu, Peter Ka Fung; Teoh, Jeremy Yuen Chun; Yee, C H

    2016-06-01

    A cross-sectional study was conducted to explore the prevalence and severity of health-related complaints perceived by adult males of Hong Kong by using the Hong Kong Traditional Chinese versions of the Aging males' symptoms (AMS) scale and the 5-dimensional and 3-level European Quality of life (EQ-5D-3L) questionnaire. A total of 825 adult males aged 40 years or above were surveyed, and observed that 80% of the population was living with little-to-mild levels of aging symptoms with mean total scores ranged between 26.02 ± 7.91 and 32.99 ± 7.91 in different age groups. Such symptoms were correlated with age, especially for the somato-vegetative and sexual symptoms. The most severe AMS symptoms were observed in the oldest age group at 70 years or above, with 76%, 34% and 70% living with moderate-to-severe levels of somato-vegetative, psychological and sexual symptoms, respectively. The result was highly correlated with the EQ-5D-3L questionnaire. Secondly, the Hong Kong Aging males' symptoms (AMS) scale was shown to have good reliability with test-retest coefficient at 0.79 (ranged 0.66-0.87) and Cronbach's alpha coefficient at 0.88 (ranged 0.70-0.84). In summary, the population of Hong Kong male adults was commonly living with little-to-mild levels of aging symptoms, whereas their severity was correlated with age. PMID:27068128

  4. A sex-specific transcription factor controls male identity in a simultaneous hermaphrodite.

    PubMed

    Chong, Tracy; Collins, James J; Brubacher, John L; Zarkower, David; Newmark, Phillip A

    2013-01-01

    Evolutionary transitions between hermaphroditic and dioecious reproductive states are found in many groups of animals. To understand such transitions, it is important to characterize diverse modes of sex determination utilized by metazoans. Currently, little is known about how simultaneous hermaphrodites specify and maintain male and female organs in a single individual. Here we show that a sex-specific gene, Smed-dmd-1 encoding a predicted doublesex/male-abnormal-3 (DM) domain transcription factor, is required for specification of male germ cells in a simultaneous hermaphrodite, the planarian Schmidtea mediterranea. dmd-1 has a male-specific role in the maintenance and regeneration of the testes and male accessory reproductive organs. In addition, a homologue of dmd-1 exhibits male-specific expression in Schistosoma mansoni, a derived, dioecious flatworm. These results demonstrate conservation of the role of DM domain genes in sexual development in lophotrochozoans and suggest one means by which modulation of sex-specific pathways can drive the transition from hermaphroditism to dioecy. PMID:23652002

  5. Strategies for recruiting steady male partners of female sex workers for HIV research

    PubMed Central

    Fleming, Paul J.; Barrington, Clare; Perez, Martha; Donastorg, Yeycy; Kerrigan, Deanna

    2014-01-01

    Steady male partners of female sex workers (FSW) are a key population for HIV prevention, but researchers face challenges finding and recruiting this population. We conducted forty in-depth interviews with FSW and steady male partners of FSW in Santo Domingo, Dominican Republic about how to engage steady male partners in HIV research. Participants cautioned that male partners might be unwilling to participate because of discomfort disclosing intimate information and cultural norms of masculinity. They recommended inviting male partners to research offices, instead of venue-based recruitment, because it was more private and trust-promoting. Most participants suggested that FSW could refer their partners or men could refer their friends who have FSW partners. Participants emphasized that referrals could break down trust-related barriers that prevent male partners from participating. Establishing an environment of respect and trust in the research setting can aid referral processes as individuals who participate communicate their positive experiences to their networks. PMID:25192901

  6. Strategies for recruiting steady male partners of female sex workers for HIV research.

    PubMed

    Fleming, Paul J; Barrington, Clare; Perez, Martha; Donastorg, Yeycy; Kerrigan, Deanna

    2015-02-01

    Steady male partners of female sex workers (FSW) are a key population for HIV prevention, but researchers face challenges finding and recruiting this population. We conducted 40 in-depth interviews with FSW and steady male partners of FSW in Santo Domingo, Dominican Republic about how to engage steady male partners in HIV research. Participants cautioned that male partners might be unwilling to participate because of discomfort disclosing intimate information and cultural norms of masculinity. They recommended inviting male partners to research offices, instead of venue-based recruitment, because it was more private and trust-promoting. Most participants suggested that FSW could refer their partners or men could refer their friends who have FSW partners. Participants emphasized that referrals could break down trust-related barriers that prevent male partners from participating. Establishing an environment of respect and trust in the research setting can aid referral processes as individuals who participate communicate their positive experiences to their networks. PMID:25192901

  7. Male Sex Workers: Practices, Contexts, and Vulnerabilities for HIV acquisition and transmission

    PubMed Central

    Baral, Stefan David; Friedman, M. Reuel; Geibel, Scott; Rebe, Kevin; Bozhinov, Borche; Diouf, Daouda; Sabin, Keith; Holland, Claire E.; Chan, Roy; Caceres, Carlos

    2015-01-01

    Summary Male sex workers (MSW) who sell/exchange sex for money or goods comprise an extremely diverse population across and within countries worldwide. Information characterizing their practices, contexts where they live, and their needs is very limited, as these men are generally included as subsets of larger studies focused on gay men and other men who have sex with men (MSM) or even female sex workers. MSW, regardless of their sexual orientation, mostly offer sex to men, and rarely identify as sex workers, using local or international terms instead. There is growing evidence of a sustained or increasing burden of HIV among some MSW in the context of the slowing global HIV pandemic. There are several synergistic facilitator spotentiating HIV acquisition and transmission among MSW, including biological, behavioural, and structural determinants. The criminalization and intersectional stigmas of same-sex practices, commercial sex, and HIV all increase HIV and STI risk for MSW and decrease their likelihood of accessing essential services. These contexts, taken together with complex sexual networks among MSW, define them as a key population underserved by current HIV prevention, treatment, and care services. Dedicated efforts are needed to make those services available for the sake of both public health and human rights. PMID:25059939

  8. Diagnosis of prolactinoma in two male-to-female transsexual subjects following high-dose cross-sex hormone therapy.

    PubMed

    Cunha, F S; Domenice, S; Câmara, V L; Sircili, M H P; Gooren, L J G; Mendonça, B B; Costa, E M F

    2015-08-01

    Male-to-female transsexual persons use oestrogens + antiandrogens to adapt their physical bodies to the female sex. Doses are usually somewhat higher than those used by hypogonadal women receiving oestrogen replacement. Particularly in cases of self-administration of cross-sex hormones, doses may be very high. Oestrogens are powerful stimulators of synthesis and release of prolactin and serum prolactin levels are usually somewhat increased following oestrogen treatment. Prolactinomas have been reported in male-to-female transsexual persons, both after use of high and conventional doses of oestrogens but remain rare events. We report two new cases of prolactinomas in male-to-female transsexual persons, one in a 41-year-old subject who had used nonsupervised high-dose oestrogen treatment since the age of 23 years and another one in a 42 year old who had initiated oestrogen treatment at the age of 17 years. Their serum prolactin levels were strongly increased, and the diagnosis of a pituitary tumour was confirmed by imaging techniques. Both cases responded well to treatment with cabergoline treatment whereupon serum prolactin normalised. Our two cases are added to the three cases of prolactinomas in the literature in persons who had used supraphysiological doses of oestrogens. PMID:25059808

  9. Age- and sex-related changes in the soft tissues of the orbital region.

    PubMed

    Sforza, Chiarella; Grandi, Gaia; Catti, Francesca; Tommasi, Davide G; Ugolini, Alessandro; Ferrario, Virgilio F

    2009-03-10

    The orbital region plays a predominant role in the evaluation of the craniofacial complex. In the current study information about normal sex-related dimensions of the orbital region, and growth, development and aging, were provided. The three-dimensional coordinates of several soft-tissue landmarks on the orbits and face were obtained by a non-invasive, computerized electromagnetic digitizer in 531 male and 357 female healthy subjects aged 4-73 years. From the landmarks, biocular and intercanthal widths, paired height and inclination of the orbit relative to both the true horizontal (head in natural head position) and Frankfurt plane, length and inclination of the eye fissure, the relevant ratios, soft-tissue orbital area, were calculated, and averaged for age and sex. Comparisons were performed by factorial analysis of variance. Biocular and intercanthal widths, length of the eye fissure, soft-tissue orbital area, and the inclination of the orbit relative to the true horizontal, were significantly larger in men than in women (p<0.01), with a significant effect of age (p<0.001), and significant agexsex interactions (p<0.001). Orbital height, and the height-to-width ratio increased as a function of age (p<0.001), but without gender-related differences. The inclination of the orbit relative to Frankfurt plane, and the inclination of the eye fissure did not differ between men and women, but modified as a function of age (p<0.001), with different sex-related patterns (sexxage interaction, p<0.001). On average, the paired measurements were symmetric, with similar values within each sex and age group. Overall, when compared to literature data, some differences were found due to both ethnicity, and different instruments. Nevertheless, during childhood, adolescence, and young adulthood, the age-related trends for linear dimensions were similar to those found in previous studies, while no previous data exist for older adults. During aging an increment in soft-tissue orbital

  10. The Sex Determination Gene transformer Regulates Male-Female Differences in Drosophila Body Size

    PubMed Central

    Rideout, Elizabeth J.; Narsaiya, Marcus S.; Grewal, Savraj S.

    2015-01-01

    Almost all animals show sex differences in body size. For example, in Drosophila, females are larger than males. Although Drosophila is widely used as a model to study growth, the mechanisms underlying this male-female difference in size remain unclear. Here, we describe a novel role for the sex determination gene transformer (tra) in promoting female body growth. Normally, Tra is expressed only in females. We find that loss of Tra in female larvae decreases body size, while ectopic Tra expression in males increases body size. Although we find that Tra exerts autonomous effects on cell size, we also discovered that Tra expression in the fat body augments female body size in a non cell-autonomous manner. These effects of Tra do not require its only known targets doublesex and fruitless. Instead, Tra expression in the female fat body promotes growth by stimulating the secretion of insulin-like peptides from insulin producing cells in the brain. Our data suggest a model of sex-specific growth in which body size is regulated by a previously unrecognized branch of the sex determination pathway, and identify Tra as a novel link between sex and the conserved insulin signaling pathway. PMID:26710087

  11. The Sex Determination Gene transformer Regulates Male-Female Differences in Drosophila Body Size.

    PubMed

    Rideout, Elizabeth J; Narsaiya, Marcus S; Grewal, Savraj S

    2015-12-01

    Almost all animals show sex differences in body size. For example, in Drosophila, females are larger than males. Although Drosophila is widely used as a model to study growth, the mechanisms underlying this male-female difference in size remain unclear. Here, we describe a novel role for the sex determination gene transformer (tra) in promoting female body growth. Normally, Tra is expressed only in females. We find that loss of Tra in female larvae decreases body size, while ectopic Tra expression in males increases body size. Although we find that Tra exerts autonomous effects on cell size, we also discovered that Tra expression in the fat body augments female body size in a non cell-autonomous manner. These effects of Tra do not require its only known targets doublesex and fruitless. Instead, Tra expression in the female fat body promotes growth by stimulating the secretion of insulin-like peptides from insulin producing cells in the brain. Our data suggest a model of sex-specific growth in which body size is regulated by a previously unrecognized branch of the sex determination pathway, and identify Tra as a novel link between sex and the conserved insulin signaling pathway. PMID:26710087

  12. Aggressive behavior of the male parent predicts brood sex ratio in a songbird

    NASA Astrophysics Data System (ADS)

    Szász, Eszter; Garamszegi, László Zsolt; Hegyi, Gergely; Szöllősi, Eszter; Markó, Gábor; Török, János; Rosivall, Balázs

    2014-08-01

    Brood sex ratio is often affected by parental or environmental quality, presumably in an adaptive manner that is the sex that confers higher fitness benefits to the mother is overproduced. So far, studies on the role of parental quality have focused on parental morphology and attractiveness. However, another aspect, the partner's behavioral characteristics, may also be expected to play a role in brood sex ratio adjustment. To test this hypothesis, we investigated whether the proportion of sons in the brood is predicted by the level of territorial aggression displayed by the father, in the collared flycatcher ( Ficedula albicollis). The proportion of sons in the brood was higher in early broods and increased with paternal tarsus length. When controlling for breeding date and body size, we found a higher proportion of sons in the brood of less aggressive fathers. Male nestlings are more sensitive to the rearing environment, and the behavior of courting males may often be used by females to assess their future parental activity. Therefore, adjusting brood sex ratio to the level of male aggression could be adaptive. Our results indicate that the behavior of the partner could indeed be a significant determinant in brood sex ratio adjustment, which should not be overlooked in future studies.

  13. The role of sexually explicit material in the sexual development of same-sex-attracted Black adolescent males.

    PubMed

    Arrington-Sanders, Renata; Harper, Gary W; Morgan, Anthony; Ogunbajo, Adedotun; Trent, Maria; Fortenberry, J Dennis

    2015-04-01

    Sexually explicit material (SEM) (including Internet, video, and print) may play a key role in the lives of Black same-sex sexually active youth by providing the only information to learn about sexual development. There is limited school- and/or family-based sex education to serve as models for sexual behaviors for Black youth. We describe the role SEM plays in the sexual development of a sample of Black same-sex attracted (SSA) young adolescent males ages 15-19. Adolescents recruited from clinics, social networking sites, and through snowball sampling were invited to participate in a 90-min, semi-structured qualitative interview. Most participants described using SEM prior to their first same-sex sexual experience. Participants described using SEM primarily for sexual development, including learning about sexual organs and function, the mechanics of same-gender sex, and to negotiate one's sexual identity. Secondary functions were to determine readiness for sex; to learn about sexual performance, including understanding sexual roles and responsibilities (e.g., "top" or "bottom"); to introduce sexual performance scripts; and to develop models for how sex should feel (e.g., pleasure and pain). Youth also described engaging in sexual behaviors (including condom non-use and/or swallowing ejaculate) that were modeled on SEM. Comprehensive sexuality education programs should be designed to address the unmet needs of young, Black SSA men, with explicit focus on sexual roles and behaviors that may be inaccurately portrayed and/or involve sexual risk-taking (such as unprotected anal intercourse and swallowing ejaculate) in SEM. This work also calls for development of Internet-based HIV/STI prevention strategies targeting young Black SSA men who may be accessing SEM. PMID:25677334

  14. Street Life and Drug Risk Behaviors Associated with Exchanging Sex Among Male Street Children in Lahore, Pakistan

    PubMed Central

    Towe, Vivian L.; Hasan, Salman ul; Zafar, S. Tariq; Sherman, Susan G.

    2009-01-01

    Background Throughout the developing world, children living on urban streets is a byproduct of economic deprivation. In Lahore, Pakistan, there are an estimated 5,000–7,000 street children. Purpose The study examined HIV risk behaviors and factors associated with exchanging sex among male street children in Lahore, Pakistan. Methods The survey was conducted from August 2003 to March 2004 among 565 registrants, ages 5–19, of Project Smile, a program that aimed to enhance the lives of street children in Lahore. We analyzed the frequency of and correlates of recent (past three months) sex exchange for money, drugs, or goods. Multivariate log-binomial regression was used to evaluate the independent effect of covariates on exchange sex. Results Approximately 40% of participants reported having exchanged sex during the past three months. In multivariate analysis, the factors associated with exchanging sex were living on the street for longer than 48 months (Prevalence Ratio [PR]=1.36, 95% Confidence Interval [CI]: 0.99–1.85), reporting ever having used drugs (PR=1.87, 1.10–3.16), cutting one’s self (PR=1.66, 95% CI: 1.26–2.19), and having heard of HIV/AIDS (PR=1.36, 95% CI: 1.03–1.80) after adjusting for demographic and street life variables. Conclusions We found high rates of sex exchange among a sample of street children in Lahore, Pakistan. The finding that children who have heard about HIV/AIDS are more likely to exchange sex suggests that children at HIV risk talk about HIV, but accuracy of their conversations is unclear. Street children in Pakistan are in great need of HIV education and safe alternatives for generating income. PMID:19237107

  15. Identification of a Sex Attractant Pheromone for Male Winterform Pear Psylla, Cacopsylla pyricola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), a major economic pest of pears, have been shown to use a female-produced sex attractant pheromone. We compared the chemical profiles obtained from cuticular extracts of diapausing and post-diapause winterform males and females, with...

  16. Sex hormones, sexual activity and plasma anticonvulsant levels in male epileptics.

    PubMed Central

    Toone, B K; Wheeler, M; Nanjee, M; Fenwick, P; Grant, R

    1983-01-01

    Testosterone, LH, FSH, PRL, and sex hormone binding globulin (SHBG) were measured in 72 male epileptic patients on chronic anticonvulsant drug regimes. Sexual activity was estimated and plasma anticonvulsants measured. Total testosterone (TT), LH, FSH, PRL, and SHBG were increased; free testosterone (FT) was decreased. Sexual activity appeared diminished particularly in relation to reduced FT. PMID:6413659

  17. Adolescent and Young Adult Male Sex Offenders: Understanding the Role of Recidivism

    ERIC Educational Resources Information Center

    Riser, Diana K.; Pegram, Sheri E.; Farley, Julee P.

    2013-01-01

    The current review explores the complex paths that can lead to adolescent and young adult males becoming sexually abusive. Because sexual abuse is an ongoing issue in our society that is often oversimplified, this article distinguishes between the various risk factors that predict sexually abusive behavior and types of sex offenders, particularly…

  18. Does Sex (Female versus Male) Influence the Impact of Class Attendance on Examination Performance?

    ERIC Educational Resources Information Center

    Cortright, Ronald N.; Lujan, Heidi L.; Cox, Julie H.; DiCarlo, Stephen E.

    2011-01-01

    The "conventional wisdom" is that grades are related to class attendance, i.e., students who attend classes more frequently obtain better grades and class attendance dramatically contributes to enhanced learning. However, the influence of sex (female vs. male) on this relationship is understudied. Furthermore, there have been several studies…

  19. Male Sex Roles and Epithets for Ethnic Women in American Slang.

    ERIC Educational Resources Information Center

    Allen, Irving Lewis

    1984-01-01

    Research shows that derogatory names used for women of ethnic outgroups (1) are aimed disproportionately at women of racial minorities; (2) stereotype physical differences between ethnic groups; (3) make derogatory sexual allusions, often using food and animal metaphors; and (4) display the strains of traditional male sex roles in ethnic and…

  20. Sex of the cell dictates its response: differential gene expression and sensitivity to cell death inducing stress in male and female cells.

    PubMed

    Penaloza, Carlos; Estevez, Brian; Orlanski, Shari; Sikorska, Marianna; Walker, Roy; Smith, Catherine; Smith, Brandon; Lockshin, Richard A; Zakeri, Zahra

    2009-06-01

    Sexual dimorphisms are typically attributed to the hormonal differences arising once sex differentiation has occurred. However, in some sexually dimorphic diseases that differ in frequency but not severity, the differences cannot be logically connected to the sex hormones. Therefore, we asked whether any aspect of sexual dimorphism could be attributed to chromosomal rather than hormonal differences. Cells taken from mice at d 10.5 postconception (PC) before sexual differentiation, at d 17.5 PC after the first embryonic assertion of sexual hormones, and at postnatal day 17 (puberty) were cultured and exposed to 400 microM ethanol or 20 microM camptothecin or to infection with influenza A virus (multiplicity of infection of 5). The results showed that untreated male and female cells of the same age grew at similar rates and manifested similar morphology. However, they responded differently to the applied stressors, even before the production of fetal sex hormones. Furthermore, microarray and qPCR analyses of the whole 10.5 PC embryos also revealed differences in gene expression between male and female tissues. Likewise, the exposure of cells isolated from fetuses and adolescent mice to the stressors and/or sex hormones yielded expression patterns that reflected chromosomal sex, with ethanol feminizing male cells and masculinizing female cells. We conclude that cells differ innately according to sex irrespective of their history of exposure to sex hormones. These differences may have consequences in the course of sexually dimorphic diseases and their therapy. PMID:19190082

  1. Adverse Childhood Experiences in the Lives of Male Sex Offenders: Implications for Trauma-Informed Care.

    PubMed

    Levenson, Jill S; Willis, Gwenda M; Prescott, David S

    2016-06-01

    This study explored the prevalence of childhood trauma in a sample of male sexual offenders (N = 679) using the Adverse Childhood Experience (ACE) scale. Compared with males in the general population, sex offenders had more than 3 times the odds of child sexual abuse (CSA), nearly twice the odds of physical abuse, 13 times the odds of verbal abuse, and more than 4 times the odds of emotional neglect and coming from a broken home. Less than 16% endorsed zero ACEs and nearly half endorsed four or more. Multiple maltreatments often co-occurred with other types of household dysfunction, suggesting that many sex offenders were raised within a disordered social environment. Higher ACE scores were associated with higher risk scores. By enhancing our understanding of the frequency and correlates of early adverse experiences, we can better devise trauma-informed interventions that respond to the clinical needs of sex offender clients. PMID:24872347

  2. Oxytocin's effect on resting-state functional connectivity varies by age and sex.

    PubMed

    Ebner, Natalie C; Chen, Huaihou; Porges, Eric; Lin, Tian; Fischer, Håkan; Feifel, David; Cohen, Ronald A

    2016-07-01

    The neuropeptide oxytocin plays a role in social cognition and affective processing. The neural processes underlying these effects are not well understood. Modulation of connectivity strength between subcortical and cortical regions has been suggested as one possible mechanism. The current study investigated effects of intranasal oxytocin administration on resting-state functional connectivity between amygdala and medial prefrontal cortex (mPFC), as two regions involved in social-cognitive and affective processing. Going beyond previous work that largely examined young male participants, our study comprised young and older men and women to identify age and sex variations in oxytocin's central processes. This approach was based on known hormonal differences among these groups and emerging evidence of sex differences in oxytocin's effects on amygdala reactivity and age-by-sex-modulated effects of oxytocin in affective processing. In a double-blind design, 79 participants were randomly assigned to self-administer either intranasal oxytocin or placebo before undergoing resting-state functional magnetic resonance imaging. Using a targeted region-to-region approach, resting-state functional connectivity strength between bilateral amygdala and mPFC was examined. Participants in the oxytocin compared to the placebo group and men compared to women had overall greater amygdala-mPFC connectivity strength at rest. These main effects were qualified by a significant three-way interaction: while oxytocin compared to placebo administration increased resting-state amygdala-mPFC connectivity for young women, oxytocin did not significantly influence connectivity in the other age-by-sex subgroups. This study provides novel evidence of age-by-sex differences in how oxytocin modulates resting-state brain connectivity, furthering our understanding of how oxytocin affects brain networks at rest. PMID:27032063

  3. Morphometric analysis of variation in the sternum with sex and age.

    PubMed

    Weaver, Ashley A; Schoell, Samantha L; Nguyen, Callistus M; Lynch, Sarah K; Stitzel, Joel D

    2014-11-01

    Age and sex-related variations in sternum morphology may affect the thoracic injury tolerance. Male and female sternum size and shape variation was characterized for ages 0-100 from landmarks collected from 330 computed tomography scans. Homologous landmarks were analyzed using Procrustes superimposition to produce age and sex-specific functions of 3D-sternum morphology representing the combined size and shape variation and the isolated shape variation. Significant changes in the combined size and shape variation and isolated shape variation of the sternum were found to occur with age in both sexes. Sternal size increased from birth through age 30 and retained a similar size for ages 30-100. The manubrium expanded laterally from birth through age 30, becoming wider in relation to the sternal body. In infancy, the manubrium was 1.1-1.2 times the width of the sternal body and this width ratio increased to 1.6-1.8 for adults. The manubrium transformed from a circular shape in infancy to an oval shape in early childhood. The distal sternal body became wider in relation to the proximal sternal body from birth through age 30 and retained this characteristic throughout adulthood. The most dramatic changes in sternum morphology occur in childhood and young adulthood when the sternum is undergoing ossification. The lesser degree of ossification in the pediatric sternum may be partly responsible for the prevalence of thoracic organ injuries as opposed to thoracic skeletal injuries in pediatrics. Sternum fractures make up a larger portion of thoracic injury patterns in adults with fully ossified sternums. The lack of substantial size or shape changes in the sternum from age 30-100 suggests that the increased incidence of sternal fracture seen in the elderly may be due to cortical thickness or bone mineral density changes in the sternum as opposed to morphological changes. PMID:24935890

  4. Aerobic capacity in wild satin bowerbirds: repeatability and effects of age, sex and condition.

    PubMed

    Chappell, Mark A; Savard, Jean-Francois; Siani, Jennifer; Coleman, Seth W; Keagy, Jason; Borgia, Gerald

    2011-10-01

    Individual variation in aerobic capacity has been extensively studied, especially with respect to condition, maturity or pathogen infection, and to gain insights into mechanistic foundations of performance. However, its relationship to mate competition is less well understood, particularly for animals in natural habitats. We examined aerobic capacity [maximum rate of O2 consumption (VO2,max) in forced exercise] in wild satin bowerbirds, an Australian passerine with a non-resource based mating system and strong intermale sexual competition. We tested for repeatability of mass and VO2,max, differences among age and sex classes, and effects of several condition indices. In adult males, we examined interactions between aerobic performance and bower ownership (required for male mating success). There was significant repeatability of mass and VO2,max within and between years, but between-year repeatability was lower than within-year repeatability. VO2,max varied with an overall scaling to mass(0.791), but most variance in VO2,max was not explained by mass. Indicators of condition (tarsus and wing length asymmetry, the ratio of tarsus length to mass) were not correlated to VO2,max. Ectoparasite counts were weakly correlated to VO2,max across all age-sex classes but not within any class. Adult males, the cohort with the most intense levels of mating competition, had higher VO2,max than juvenile birds or adult females. However, there was no difference between the VO2,max of bower-owning males and that of males not known to hold bowers. Thus one major factor determining male reproductive success was not correlated to aerobic performance. PMID:21900466

  5. The Leicester cerebral haemodynamics database: normative values and the influence of age and sex.

    PubMed

    Patel, Nikil; Panerai, Ronney B; Haunton, Victoria; Katsogridakis, Emmanuel; Saeed, Nazia P; Salinet, Angela; Brodie, Fiona; Syed, Nazia; D'Sa, Schnell; Robinson, Thompson G

    2016-09-01

    Normative values of physiological parameters hold significance in modern day clinical decision-making. Lack of such normative values has been a major hurdle in the translation of research into clinical practice. A large database containing uniform recordings was constructed to allow more robust estimates of normative ranges and also assess the influence of age and sex. Doppler recordings were performed on healthy volunteers in the same laboratory, using similar protocols and equipment. Beat-to-beat blood pressure, heart-rate, electrocardiogram, and end-tidal CO2 were measured continuously. Bilateral insonation of the middle cerebral arteries (MCAs) was performed using TCD following a 15 min stabilisation, and a 5 min baseline recording. Good quality Doppler recordings for both MCAs were obtained in 129 participants (57 female) with a median age of 57 years (range 20-82). Age was found to influence baseline haemodynamic and transfer function analysis parameters. Cerebral blood flow velocity and critical closing pressure were the only sex-related differences found, which was significantly higher in females than males. Normative values for cerebral haemodynamic parameters have been defined in a large, healthy population. Such age/sex-defined normal values can be used to reduce the burden of collecting additional control data in future studies, as well as to identify disease-associated changes. PMID:27511128

  6. Mandibular ramus length as an indicator of chronological age and sex.

    PubMed

    de Oliveira, Fernando Toledo; Soares, Mariana Quirino Silveira; Sarmento, Viviane Almeida; Rubira, Cassia Maria Fischer; Lauris, José Roberto Pereira; Rubira-Bullen, Izabel Regina Fischer

    2015-01-01

    Age and sex estimation is crucial in forensic investigations, whether in legal situations that involve living people or to identify mortal remains. The aim of this study was to establish reference values in a Brazilian population to estimate age and sex by measuring the length of the mandibular ramus on lateral cephalometric radiographs, and to determine the probability that an individual being is 18 years or older, based on the results that were obtained. Two hundred and eighteen scanned lateral cephalograms of individuals between 6 and 20 years of age (101 males and 117 females) were measured with reference to mandibular ramus length (the distance between Condylion superior (Cs) and Gonion (Go)) using ImageJ 1.41 software (NIH, Bethesda, MA, USA). The results showed that sexual dimorphism was not observed until 16 years and, based on the ramus length measurements in this sample, it is possible to predict sex with an accuracy of only 54 %. There was a positive correlation between age and ramus length (r = 0.90; p < 0.001). From the linear regression analysis, one formula was derived; therefore, it was possible to calculate the individual's age, given his or her ramus length. The results showed that if an individual's ramus length is 7.0 cm or more, then there is an 81.25 % chance that the individual is 18 years old or older. In conclusion, the mandibular ramus length was not effective in discriminating sex. Mandibular length is strongly related to chronological age and can be used to predict whether an individual is 18 years or older with high degree of expected accuracy. PMID:25270589

  7. When sex work becomes your everything: The complex linkages between economy and affection among male sex workers in Peru

    PubMed Central

    Bayer, Angela M.; Garvich, Mijail; Díaz, David A.; Sánchez, Hugo; García, Patricia J.; Coates, Thomas J.

    2014-01-01

    In Peru, there are few studies on male sex workers (MSWs) and existing studies explore limited sub-groups or offer limited information about MSWs’ perspectives. This study provides in-depth perspectives from 40 MSWs who work in downtown Lima (Cercado) and in surrounding urban neighborhoods (non-Cercado) through interviews on their identities, lives and HIV/STI risks and vulnerabilities. Findings are that entry into sex work links economy and affection, particularly among Cercado MSWs. Continued sex work cements this link, making it difficult to exit sex work and establish goals. Ties between economics and affections influence MSWs’ perceived HIV/STI risks, vulnerabilities and prevention practices. Although Cercado MSWs report higher HIV/STI risks and vulnerabilities than non-Cercado peers, they report fewer prevention practices given inability to buy condoms and acceptance of client offers of higher payment, especially clients they feel affection for. MSWs need support to strengthen their self-perceptions and define and pursue their goals in order to improve their HIV/STI prevention practices, health and well-being. PMID:24368712

  8. The Association between the Levels of Serum Ferritin and Sex Hormones in a Large Scale of Chinese Male Population

    PubMed Central

    Zhang, Haiying; Gao, Yong; Tan, Aihua; Zhang, Shijun; Xiao, Qiang; Zhang, Bing; Huang, Lulu; Ye, Bingbing; Qin, Xue; Wu, Chunlei; Lu, Zheng; Zhang, Youjie; Liao, Ming; Yang, Xiaobo; Mo, Zengnan

    2013-01-01

    Background The ferritin is an important participant of iron-storage but its regulation and related factors were not well defined. The present objective was to explore the potential association between serum ferritin levels and sex hormones. Methods 1999 Chinese men in the Fangchenggang Area Male Health and Examination Survey (FAMHES) were recruited in this cross-sectional study. Levels of serum ferritin, total testosterone (free testosterone was calculated from the total one), estradiol and sex hormone-binding protein were detected in venous blood samples. The effects of age, BMI, smoking as well as alcohol consumption were analyzed on ferritin levels, respectively, and then the Pearson’s correlation analysis was used to evaluate the association between ferritin levels and sex hormones adjusting for the above factors. Results The age, BMI and alcohol consumption significantly affected serum ferritin levels, but there was no significant difference between smokers and nonsmokers. Ferritin levels were significantly and negatively associated with total testosterone (R = −0.205, P< 0.001), sex hormone-binding protein (R = −0.161, P<0.001) and free testosterone (R = −0.097, P<0.001). After age and alcohol consumption were adjusted, the above associations were still significant (R = −0.200, −0.181 and −0.083, respectively, all P<0.001). However, there was only borderline negative association between ferritin levels and estradiol (adjusted R = −0.039, P = 0.083). Conclusion The large scale of epidemic results showed the significantly negative associations between serum ferritin levels and sex hormones, which may provide more clues to explore the potential regulation and biological mechanism of ferritin. PMID:24146788

  9. Sex and Age Aspects in Patients Suffering From Out-Of-Hospital Cardiac Arrest

    PubMed Central

    Piegeler, Tobias; Thoeni, Nils; Kaserer, Alexander; Brueesch, Martin; Sulser, Simon; Mueller, Stefan M.; Seifert, Burkhardt; Spahn, Donat R.; Ruetzler, Kurt

    2016-01-01

    Abstract Cardiopulmonary resuscitation (CPR) is indicated in patients suffering from out-of-hospital cardiac arrest. Several studies suggest a sex- and age-based bias in the treatment of these patients. This particular bias may have a significant impact on the patient's outcome. However, the reasons for these findings are still unclear and discussed controversially. Therefore, the aim of this study was to retrospectively analyze treatment and out-of-hospital survival rates for potential sex- and age-based differences in patients requiring out-of-hospital CPR provided by an emergency physician in the city of Zurich, Switzerland. A total of 3961 consecutive patients (2003–2009) were included in this retrospective analysis to determine the frequency of out-of-hospital CPR and prehospital survival rate, and to identify potential sex- and age-based differences regarding survival and treatment of the patients. Seven hundred fifty-seven patients required CPR during the study period. Seventeen patients had to be excluded because of incomplete or inconclusive documentation, resulting in 743 patients (511 males, 229 females) undergoing further statistical analysis. Female patients were significantly older, compared with male patients (68 ± 18 [mean ± SD] vs 64 ± 18 years, P = .012). Men were resuscitated slightly more often than women (86.4% vs 82.1%). Overall out-of-hospital mortality rate was found to be 81.2% (492/632 patients) with no differences between sexes (82.1% for males vs 79% for females, odds ratio 1.039, 95% confidence interval 0.961–1.123). No sex differences were detected in out-of-hospital treatment, as assessed by the different medications administered, initial prehospital Glasgow Coma Scale, and prehospital suspected leading diagnosis. The data of our study demonstrate that there was no sex-based bias in treating patients requiring CPR in the prehospital setting in our physician-led emergency ambulance service. PMID:27149475

  10. Sex- and age- specific relations between economic development, economic inequality and homicide rates in people aged 0-24 years: a cross-sectional analysis.

    PubMed Central

    Butchart, Alexander; Engström, Karin

    2002-01-01

    OBJECTIVE: To test whether relations between economic development, economic inequality, and child and youth homicide rates are sex- and age-specific, and whether a country's wealth modifies the impact of economic inequality on homicide rates. METHODS: Outcome variables were homicide rates around 1994 in males and females in the age ranges 0-4, 5-9, 10-14, 15-19 and 20-24 years from 61 countries. Predictor variables were per capita gross domestic product (GDP), GINI coefficient, percentage change in per capita gross national product (GNP) and female economic activity as a percentage of male economic activity. Relations were analysed by ordinary least squares regression. FINDINGS: All predictors explained significant variances in homicide rates in those aged 15-24. Associations were stronger for males than females and weak for children aged 0-9. Models that included female economic inequality and percentage change in GNP increased the effect in children aged 0-9 and the explained variance in females aged 20-24. For children aged 0-4, country clustering by income increased the explained variance for both sexes. For males aged 15-24, the association with economic inequality was strong in countries with low incomes and weak in those with high incomes. CONCLUSION: Relations between economic factors and child and youth homicide rates varied with age and sex. Interventions to target economic factors would have the strongest impact on rates of homicide in young adults and late adolescent males. In societies with high economic inequality, redistributing wealth without increasing per capita GDP would reduce homicide rates less than redistributions linked with overall economic development. PMID:12471400

  11. Sex- and age-specific trends in antibiotic resistance patterns of Escherichia coli urinary isolates from outpatients

    PubMed Central

    2013-01-01

    Background Urinary tract infections (UTIs) are one of the most common infections treated in ambulatory care settings, however the epidemiology differs by age and sex. The incidence of UTI is far greater in females than males, and infection in pediatric patients is more often due to anatomical abnormalities. The purpose of this research was to describe age- and sex-specific trends in antibiotic susceptibility to common urinary anti-infectives among urinary isolates of Escherichia coli from ambulatory primary care patients in a regional health maintenance organization. Methods Clinical microbiology data were collected for all urine cultures from patients with visits to primary care clinics in a regional health maintenance organization between 2005 and 2010. The first positive culture for E. coli tested for antibiotic susceptibilities per patient per year was included in the analysis dataset. The frequency of susceptibility to ampicillin, amoxicillin-clavulanate, ciprofloxacin, nitrofurantoin, and trimethoprim/sulfamethoxazole (TMP/SMX) was calculated for male and female patients. The Cochrane-Mantel-Haenzel test was used to test for differences in age-stratified susceptibility to each antibiotic between males and females. Results A total of 43,493 E. coli isolates from 34,539 unique patients were identified for study inclusion. After stratifying by age, E. coli susceptibility to ampicillin, amoxicillin-clavulanate, ciprofloxacin, and nitrofurantoin differed significantly between males and females. However, the magnitude of the differences was less than 10% for all strata except amoxicillin-clavulanate susceptibility in E. coli isolated from males age 18–64 compared to females of the same age. Conclusions We did not observe clinically meaningful differences in antibiotic susceptibility to common urinary anti-infectives among E. coli isolated from males versus females. These data suggest that male sex alone should not be used as an indication for empiric use of

  12. Stigma, social inequality, and HIV risk disclosure among Dominican male sex workers☆

    PubMed Central

    Padilla, Mark; Castellanos, Daniel; Guilamo-Ramos, Vincent; Reyes, Armando Matiz; Sánchez Marte, Leonardo E.; Soriano, Martha Arredondo

    2010-01-01

    Some quantitative behavioral studies in the USA have concluded that bisexually behaving Latino men are less likely than White men to disclose to their female partners that they have engaged in same-sex risk behavior and/or are HIV-positive, presumably exposing female partners to elevated risk for HIV infection. Nevertheless, very little theoretical or empirical research has been conducted to understand the social factors that promote or inhibit sexual risk disclosure among Latino men who have sex with men (MSM), and much of the existing literature has neglected to contextualize disclosure patterns within broader experiences of stigma and social inequality. This paper examines decisions about disclosure of sex work, same-sex behavior, and sexual risk for HIV among male sex workers in two cities in the Dominican Republic. Data derive from long-term ethnography and qualitative in-depth interviews with 72 male sex workers were used to analyze the relationships among experiences of stigma, social inequality, and patterns of sexual risk disclosure. Thematic analysis of interviews and ethnographic evidence revealed a wide range of stigma management techniques utilized by sex workers to minimize the effects of marginality due to their engagement in homosexuality and sex work. These techniques imposed severe constraints on men’s sexual risk disclosure, and potentially elevated their own and their female partners’ vulnerability to HIV infection. Based on the study’s findings, we conclude that future studies of sexual risk disclosure among ethnic minority MSM should avoid analyzing disclosure as a decontextualized variable, and should seek to examine sexual risk communication as a dynamic social process constrained by hierarchical systems of power and inequality. PMID:18410986

  13. Sociodemographic characteristics and HIV risk behaviour patterns of male sex workers in Madrid, Spain.

    PubMed

    Belza, M J; Llácer, A; Mora, R; Morales, M; Castilla, J; de la Fuente, L

    2001-10-01

    This paper describes the sociodemographic and work characteristics, prevalence of HIV infection and associated risk behaviours among male sex workers (MSWs) in Madrid (Spain). Using an anonymous semi-structured questionnaire, educators attached to a mobile unit under a street-based prostitution programme surveyed 84 MSWs from several Madrid areas. Of the total surveyed: 35% were immigrants, mean age was 23 years, mean period in prostitution was four years; 21% had no primary education; 16% had injected drugs at some time; 11% reported private sexual relationships exclusively with women; 89% always used condoms in anal practices with clients; and 41% were in sexual relationships with their partners. Only 11% had ever used fortified condoms. In the preceding month, 37% had experienced condom failure, 82% without having used any lubricant. In all, 67% reported having undergone HIV testing, with a higher percentage of positive results among injecting (60%) versus non-injecting drug users (17%). Immigrants had a lower level of education, made less use of condoms, had more condom failures and, in their private lives, a greater proportion reported sexual relationships exclusively with women. In Spain, MSWs should be included in HIV prevention programmes, which ought to be specifically adapted to immigrants. Priority should be given to reducing the condom failure rate in anal intercourse, by improving access to fortified condoms. PMID:11571014

  14. Stigma in Male Depression and Suicide: A Canadian Sex Comparison Study.

    PubMed

    Oliffe, John L; Ogrodniczuk, John S; Gordon, Susan J; Creighton, Genevieve; Kelly, Mary T; Black, Nick; Mackenzie, Corey

    2016-04-01

    Stigma in men's depression and suicide can restrict help-seeking, reduce treatment compliance and deter individuals from confiding in friends and family. In this article we report sex comparison findings from a national survey of English-speaking adult Canadians about stigmatized beliefs concerning male depression and suicide. Among respondents without direct experience of depression or suicide (n = 541) more than a third endorsed the view that men with depression are unpredictable. Overall, a greater proportion of males endorsed stigmatizing views about male depression compared to female respondents. A greater proportion of female respondents endorsed items indicating that men who suicide are disconnected, lost and lonely. Male and female respondents with direct personal experience of depression or suicide (n = 360) strongly endorsed stigmatizing attitudes toward themselves and a greater proportion of male respondents indicated that they would be embarrassed about seeking help for depression. PMID:26733336

  15. Synergistic Disruption of External Male Sex Organ Development by a Mixture of Four Antiandrogens

    PubMed Central

    Christiansen, Sofie; Scholze, Martin; Dalgaard, Majken; Vinggaard, Anne Marie; Axelstad, Marta; Kortenkamp, Andreas; Hass, Ulla

    2009-01-01

    Background By disrupting the action of androgens during gestation, certain chemicals present in food, consumer products, and the environment can induce irreversible demasculinization and malformations of sex organs among male offspring. However, the consequences of simultaneous exposure to such chemicals are not well described, especially when they exert their actions by differing molecular mechanisms. Objectives To fill this gap, we investigated the effects of mixtures of a widely used plasticizer, di(2-ethylhexyl) phthalate (DEHP); two fungicides present in food, vinclozolin and prochloraz; and a pharmaceutical, finasteride, on landmarks of male sexual development in the rat, including changes in anogenital distance (AGD), retained nipples, sex organ weights, and malformations of genitalia. These chemicals were chosen because they disrupt androgen action with differing mechanisms of action. Results Strikingly, the effect of combined exposure to the selected chemicals on malformations of external sex organs was synergistic, and the observed responses were greater than would be predicted from the toxicities of the individual chemicals. In relation to other hallmarks of disrupted male sexual development, including changes in AGD, retained nipples, and sex organ weights, the combined effects were dose additive. When the four chemicals were combined at doses equal to no observed adverse effect levels estimated for nipple retention, significant reductions in AGD were observed in male offspring. Conclusions Because unhindered androgen action is essential for human male development in fetal life, these findings are highly relevant to human risk assessment. Evaluations that ignore the possibility of combination effects may lead to considerable underestimations of risks associated with exposures to chemicals that disrupt male sexual differentiation. PMID:20049201

  16. Correlates of HIV, STIs and Associated High Risk Behaviors among Male Clients of Female Sex Workers in Tijuana, Mexico

    PubMed Central

    Patterson, Thomas L.; Goldenberg, Shira; Gallardo, Manuel; Lozada, Remedios; Semple, Shirley J.; Orozovich, Prisci; Abramovitz, Daniela; Strathdee, Steffanie A.

    2009-01-01

    Objectives To determine sociodemographic and behavioral correlates of HIV infection among male clients of FSWs in Tijuana. Methods 400 men aged 18 or older who had paid or traded for sex with a FSW in Tijuana during the past 4 months were recruited in Tijuana’s “zone of tolerance,” where prostitution is practiced openly under a municipal permit system. Efforts were made to balance the sample between residents of the U.S. (San Diego County) and of Mexico (Tijuana). Participants underwent interviews and testing for HIV, syphilis, gonorrhea, and Chlamydia. Logistic regression identified correlates of HIV infection. Results Mean age was 36.6. One quarter had injected drugs within the previous 4 months. Lifetime use of heroin, cocaine and methamphetamine was 36%, 50% and 64%, respectively. Men had frequented FSWs for an average of 11 years, visiting FSWs an average of 26 times last year. In the past four months, one half reported having unprotected sex with an FSW; 46% reported frequently being high when having sex with an FSW. Prevalence of HIV, syphilis, gonorrhea, and Chlamydia was 4%, 2%, 2.5% and 7.5%; 14.2% were positive for at least one infection. Factors independently associated with HIV infection were living in Mexico, ever using methamphetamine, living alone, and testing positive for syphilis. Conclusions Male clients of FSWs in Tijuana had a high sex and drug risk profile. While STI prevalence was lower than among FSWs, HIV prevalence was comparable, suggesting the need for interventions among clients to prevent spread of HIV and STIs. PMID:19584699

  17. Co-occurrence of antisocial behavior and substance use: testing for sex differences in the impact of older male friends, low parental knowledge and friends' delinquency.

    PubMed

    McAdams, Tom A; Salekin, Randall T; Marti, C Nathan; Lester, Whiney S; Barker, Edward D

    2014-04-01

    Delinquency and substance use (SU) are commonly comorbid during adolescence. In the present study we investigate this co-morbidity with 3 main objectives: 1. Evaluate reciprocal relationships between delinquency/SU across early adolescence. 2. Assess the impact of older male friends, low parental knowledge and friends' delinquency on subsequent development and inter-relationships of delinquency and SU. 3. Evaluate sex differences in these relationships. We applied cross-lagged structural equation models to the analysis of a longitudinal sample (n=3699). Findings demonstrated: (1) At ages 13-14 delinquency predicted SU more so than vice versa but effects became equal between ages 14 and 15. (2) Low parental knowledge and friends' delinquency predicted delinquency and SU. Older male friends predicted ASB. (3) Sex differences were present. For example, in the absence of antisocial friends low parent knowledge at age 12 indirectly predicted increased age 15 SU for girls more than boys. PMID:24636685

  18. Ploidy, sex and crossing over in an evolutionary aging model

    NASA Astrophysics Data System (ADS)

    Lobo, Matheus P.; Onody, Roberto N.

    2006-02-01

    Nowadays, many forms of reproduction coexist in nature: Asexual, sexual, apomictic and meiotic parthenogenesis, hermaphroditism and parasex. The mechanisms of their evolution and what made them successful reproductive alternatives are very challenging and debated questions. Here, using a simple evolutionary aging model, we give a possible scenario. By studying the performance of populations where individuals may have diverse characteristics-different ploidies, sex with or without crossing over, as well as the absence of sex-we find an evolution sequence that may explain why there are actually two major or leading groups: Sexual and asexual. We also investigate the dependence of these characteristics on different conditions of fertility and deleterious mutations. Finally, if the primeval organisms on Earth were, in fact, asexual individuals we conjecture that the sexual form of reproduction could have more easily been set and found its niche during a period of low-intensity mutations.

  19. Evolution of male age-specific reproduction under differential risks and causes of death: males pay the cost of high female fitness.

    PubMed

    Chen, H-Y; Spagopoulou, F; Maklakov, A A

    2016-04-01

    Classic theories of ageing evolution predict that increased extrinsic mortality due to an environmental hazard selects for increased early reproduction, rapid ageing and short intrinsic lifespan. Conversely, emerging theory maintains that when ageing increases susceptibility to an environmental hazard, increased mortality due to this hazard can select against ageing in physiological condition and prolong intrinsic lifespan. However, evolution of slow ageing under high-condition-dependent mortality is expected to result from reallocation of resources to different traits and such reallocation may be hampered by sex-specific trade-offs. Because same life-history trait values often have different fitness consequences in males and females, sexually antagonistic selection can preserve genetic variance for lifespan and ageing. We previously showed that increased condition-dependent mortality caused by heat shock leads to evolution of long-life, decelerated late-life mortality in both sexes and increased female fecundity in the nematode, Caenorhabditis remanei. Here, we used these cryopreserved lines to show that males evolving under heat shock suffered from reduced early-life and net reproduction, while mortality rate had no effect. Our results suggest that heat-shock resistance and associated long-life trade-off with male, but not female, reproduction and therefore sexually antagonistic selection contributes to maintenance of genetic variation for lifespan and fitness in this population. PMID:26801472

  20. Age- and sex-dependent change in stratum corneum sphingolipids.

    PubMed

    Denda, M; Koyama, J; Hori, J; Horii, I; Takahashi, M; Hara, M; Tagami, H

    1993-01-01

    We measured six stratum corneum sphingolipid species (ceramides 1-6) in 26 males and 27 females, and found a significant change in their percentage composition only among female subjects of different age groups. There was a significant increase in ceramide 1 and 2 with a corresponding decrease in ceramide 3 and 6 from prepubertal age to adulthood. Thereafter the ratio of ceramide 2 to total sphingolipids decreased with age in contrast to ceramide 3 which showed an increase. Such a pattern of change in the aging population is different from that observed in scaly skin experimentally induced by tape stripping. The present results suggest a significant influence of female hormones on the composition of stratum corneum sphingolipids. Moreover, the different patterns of change in sphingolipid composition of stratum corneum lipids between scales from inflammatory skin and those from aged skin also suggest that epidermal biosynthesis of sphingolipids is influenced by epidermal proliferative activity. PMID:8304781

  1. Incidence of Major Depressive Disorder: Variation by Age and Sex in Low-Income Individuals

    PubMed Central

    Lee, Chun-Te; Chiang, Yi-Cheng; Huang, Jing-Yang; Tantoh, Disline M.; Nfor, Oswald N.; Lee, Jia-Fu; Chang, Cheng-Chen; Liaw, Yung-Po

    2016-01-01

    Abstract Major depressive disorder (MDD), the most prevalent mental disorder is a global public health issue. The aim of this study was to assess the association between low income and major depressive disorder (MDD) by age and sex. The National Health Insurance Research Database (NHIRD) of Taiwan was used to retrieve data. A total of 1,743,948 participants were eligible for the study. Low-income individuals were identified from 2001 and 2003 (specifically, Group Insurance Applicants, ie, category“51” or “52”) and followed from 2004 to 2010. MDD was identified using the ICD-9-CM 296.2 and 296.3 codes. Among non-low-income individuals, the MDD incidence rates increased with age in both males and females, that is, 0.35, 0.93, 0.97, 1.40 per 10,000 person-months for males and 0.41, 1.60, 1.89, 1.95 per 10,000 person-months for females aged 0 to 17, 18 to 44, 45 to 64, and ≥65 years, respectively. Low-income females (18–44 years) and males (45–64 years) had the highest incidence of MDD, which was 3.90 and 3.04, respectively, per 10,000 person-months. Among low and non-low-income individuals, the MDD incidence rates were higher in the females than males in all age groups. Males aged 45 to 64 and 0 to 17 years had highest hazard ratios (HR) of 2.789 (95% confidence interval [CI], 1.937–4.014) and 2.446 (95% CI, 1.603–3.732), respectively. The highest HRs for females were 2.663 (95% CI, 1.878–3.775) and 2.219 (CI, 1.821–2.705) in the 0 to 17 and 18- to 44-year age groups. Low income was not found to serve as a risk factor for the development of MDD in males and females aged ≥65 years. Among the non-low-income males and females, the incidence rates of MDD were found to increase with age. Low income was found to serve as a significant risk factor for MDD only in individuals under age 65. PMID:27082549

  2. Apolipoprotein E and Alzheimer disease: genotype-specific risks by age and sex.

    PubMed Central

    Bickeböller, H; Campion, D; Brice, A; Amouyel, P; Hannequin, D; Didierjean, O; Penet, C; Martin, C; Pérez-Tur, J; Michon, A; Dubois, B; Ledoze, F; Thomas-Anterion, C; Pasquier, F; Puel, M; Demonet, J F; Moreaud, O; Babron, M C; Meulien, D; Guez, D; Chartier-Harlin, M C; Frebourg, T; Agid, Y; Martinez, M; Clerget-Darpoux, F

    1997-01-01

    The distribution of apolipoprotein E (APOE) genotypes as a function of age and sex has been examined in a French population of 417 Alzheimer disease (AD) patients and 1,030 control subjects. When compared to the APOE epsilon3 allele, an increased risk associated with the APOE epsilon4 allele (odds ratio [OR] [epsilon4] = 2.7 with 95% confidence interval [CI] = 2.0-3.6; P < .001) and a protective effect of the APOE epsilon2 allele (OR[epsilon2] = 0.5 with 95% CI = 0.3-0.98; P = .012) were retrieved. An effect of the epsilon4 allele dosage on susceptibility was confirmed (OR[epsilon4/epsilon4] vs. the epsilon3/epsilon3 genotype = 11.2 [95% CI = 4.0-31.6]; OR[epsilon3/epsilon4] vs. the epsilon3/epsilon3 genotype = 2.2 [95% CI = 1.5-3.5]). The frequency of the epsilon4 allele was lower in male cases than in female cases, but, since a similar difference was found in controls, this does not lead to a difference in OR between sex. ORs for the epsilon4 allele versus the epsilon3 allele, OR(epsilon4), were not equal in all age classes: OR(epsilon4) in the extreme groups with onset at < 60 years or > 79 years were significantly lower than those from the age groups 60-79 years. In epsilon3/epsilon4 individuals, sex-specific lifetime risk estimates by age 85 years (i.e., sex-specific penetrances by age 85 years) were 0.14 (95% CI 0.04-0.30) for men and 0.17 (95% CI 0.09-0.28) for women. PMID:9012418

  3. Apolipoprotein E and Alzheimer disease: Genotype-specific risks by age and sex

    SciTech Connect

    Bickeboeller, H. |; Babron, M.C.; Clerget-Darpoux, F.

    1997-02-01

    The distribution of apolipoprotein E (APOE) genotypes as a function of age and sex has been examined in a French population of 417 Alzheimer disease (AD) patients and 1,030 control subjects. When compared to the APOE {epsilon}3 allele, an increased risk associated with the APOE {epsilon}4 allele (odds ratio [OR] [{epsilon}4] = 2.7 with 95% confidence interval [CI] = 2.0-3.6; P < .001) and a protective effect of the APOE {epsilon}2 allele (OR[{epsilon}2] = 0.5 with 95% CI = 0.3-0.98; P = .012) were retrieved. An effect of the {epsilon}4 allele dosage on susceptibility was confirmed (OR[{epsilon}4/{epsilon}4] vs. the {epsilon}3/{epsilon}3 genotype = 11.2 [95% CI = 4.0-31.6]; OR[{epsilon}3/{epsilon}4] vs. the {epsilon}3/{epsilon}3 genotype = 2.2 [95% Cl = 1.5-3.5]). The frequency of the {epsilon}4 allele was lower in male cases than in female cases, but, since a similar difference was found in controls, this does not lead to a difference in OR between sex. ORs for the {epsilon}4 allele versus the {epsilon}3 allele, OR({epsilon}4), were not equal in all age classes: OR({epsilon}4) in the extreme groups with onset at < 60 years or > 79 years were significantly lower than those from the age groups 60-79 years. In {epsilon}3/{epsilon}4 individuals, sex-specific lifetime risk estimates by age 85 years (i.e., sex-specific penetrances by age 85 years) were 0.14 (95% CI 0.04-0.30) for men and 0.17 (95% CI 0.09-0.28) for women. 53 refs., 1 fig., 3 tabs.

  4. Total Testosterone and Calculated Estimates for Free and Bioavailable Testosterone: Influence of Age and Body Mass Index and Establishment of Sex-Specific Reference Ranges.

    PubMed

    Deutschbein, T; Mann, K; Petersenn, S

    2015-10-01

    Measurement of sex steroids is required to evaluate gonadal function, but normative data are lacking (especially for estimates of physiologically active testosterone). Using modern immunoassays, this study established sex-specific reference ranges (2.5% and 97.5% percentiles) for total testosterone (TOT), bioactive testosterone Vermeulen (BTV), free androgen index (FAI), free testosterone Sartorius (FTS), free testosterone Vermeulen (FTV), and sex hormone binding globulin (SHBG). In the comparative study, subjects were grouped by age (18-30; 31-50; >50 years), BMI (<25; 25-30; >30 kg/m(2)), and sex. Study participants were selected in such a way that each group comprised 12 subjects (e.g., 12 males between 18 and 30 years with a BMI of <25 kg/m(2), and so on), resulting in a total of 216 controls (108 males, 108 females; age: 40.3 ± 1.0; BMI: 27.8 ± 0.4). Multiple stepwise regression analyses were performed (covariates: age, BMI, sex), and sex-specific reference ranges were applied to 50 males (age: 46.1 ± 2.3; BMI: 27.4 ± 0.7) with suspected hypogonadism. Regression analysis identified the strongest predictor of each parameter apart from sex, resulting in age-specific (males: FAI, SHBG, BTV, FTV; females: TOT, FTS, SHBG), BMI-specific (males: TOT, FTS; females: FAI, BTV, FTV) and overall cutoffs for both sexes. In male patients, overall agreement between the results derived from the estimates (i.e., BTV, FTS, FTV) was high (with discordant results in only 4%). In summary, if both the endocrine workup and the clinical presentation were taken into account, the newly established reference ranges allowed reliable identification of hypogonadal males. PMID:25565093

  5. Age and sex determination of juvenile band-tailed pigeons

    USGS Publications Warehouse

    White, J.A.; Braun, C.E.

    1978-01-01

    Captive band-tailed pigeons (Columbafasciata) were studied to document progression of molts and plumages from juvenal to adult age. Immature pigeons began the post-juvenal molt at 35 days which continued up to 340 days. The only 3 plumage characters useful for identification and estimation of age were presence of juvenal lesser, middle, and greater secondary coverts, juvenal secondaries, and juvenal primaries. While juvenal primaries were still present, hatching dates could be estimated up to 252 days (N = 84). Secondary feather presence and molt stage could be used to identify juvenile pigeons for more than 340 days (N = 24). Using coloration of the crown and breast feathers, 96 percent of the immature pigeons examined (106 of 110) at 80 days of age were classified accurately as to sex.

  6. [Electrophysiological and behavioral responses of male Apamea apameoides (Draudt) (Lepidoptera: Noctuidae) to sex pheromone components].

    PubMed

    Zhang, Ai-Liang; Zhou, Zhang-Ting; Zhang, Ya-Bo; Zhou, Zhi-Feng; Shen, Zhi-Lian; Wang, Hao-Jie; Shu, Jin-Ping

    2014-10-01

    The sex pheromone gland extracts collected from calling females of Apamea apameoides (Lepidoptera: Noctuidae) were analyzed with GC-MS, the electrophysiological and behavioral responses of the male adults to serial dilutions of sex pheromone components and their synthetic blends were investigated with Y-tube olfactometer in laboratory and in bamboo forest field. The results indicated that (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol were the functional components in the sex pheromone gland extracts. Electroantennogram (EAG) recordings showed that sex pheromone gland extracts, (Z)-11-hexadecenyl acetate, (Z)-11-hexadecen-1-ol and the mixture of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol all could elicit strong EAG responses, and the average EAG values increased with the increasing concentration of the sex pheromone. The blends of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol at the ratio of 57:43 elicited a higher EAG value than each singular component did. The results of behavioral assay by Y-tube olfactometer accorded with those of EAG responses on the whole, and the mixture of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol at the ratio of 57:43 was more attractive than each component alone. In field tests with silicone rubber as pheromone dispensers (concentration = 10(4) ng · uL(-1)), the average number of male adults captured per trap by the mixture was (48.5 ± 6.7). PMID:25796914

  7. Electrophysiological and behavioral responses of Diaphania glauculalis males to female sex pheromone.

    PubMed

    Ma, Tao; Liu, Zhi Tao; Zhang, Yuan Yuan; Sun, Zhao Hui; Li, Yi Zhen; Wen, Xiu Jun; Chen, Xiao Yang

    2015-10-01

    The aim of this study is to identify the pheromone active component of female moths, Diaphania glauculalis, an important pest of Anthocephalus chinensis in China. The sex pheromone was extracted from sex pheromone gland extracts of virgin female moth of D. glauculalis using n-hexane, and the pheromone gland extracts of females were analyzed using coupled gas chromatography-electroantennogram detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS). The sex pheromone active components were based on the comparison the retention time and mass spectrum, with suitable synthetic compounds. (E)-11-hexadecenal (E11-16:Ald) and (E,E)-10,12-hexadecadienal (E10E12-16:Ald) were identified as the major sex pheromone components in the females. Their biological activities were evaluated in a series of electroantennogram (EAG) experiments and four-arm olfactometer assays using synthetic compounds. D. glauculalis males could be attracted by any single component, but a mixture of the E11-16:Ald and E10E12-16:Ald in a ratio of 5:5 elicited a substantial response, demonstrating that the binary blend is essential in male attraction. We therefore conclude that the aldehyde compounds, a mixture of E11-16:Ald and E10E12-16:Ald, comprise the sex pheromone components of D. glauculalis, which might be applied for insect field trapping. PMID:26002369

  8. Morphometric analysis of variation in the ribs with age and sex.

    PubMed

    Weaver, Ashley A; Schoell, Samantha L; Stitzel, Joel D

    2014-08-01

    Rib cage morphology changes with age and sex are expected to affect thoracic injury mechanisms and tolerance, particularly for vulnerable populations such as pediatrics and the elderly. The size and shape variation of the external geometry of the ribs was characterized for males and females aged 0-100 years. Computed tomography (CT) scans from 339 subjects were analyzed to collect between 2700 and 10 400 homologous landmarks from each rib. Rib landmarks were analyzed using the geometric morphometric technique known as Procrustes superimposition. Age- and sex-specific functions of 3D rib morphology were produced representing the combined size and shape variation and the isolated shape variation. Statistically significant changes in the size and shape variation (P < 0.0001) and shape variation (P < 0.0053) of all 24 ribs were found to occur with age in males and females. Rib geometry, location, and orientation varied according to the rib level. From birth through adolescence, the rib cage experienced an increase in size, a decrease in thoracic kyphosis, and inferior rotation of the ribs relative to the spine within the sagittal plane. From young adulthood into elderly age, the rib cage experienced increased thoracic kyphosis and superior rotation of the ribs relative to the spine within the sagittal plane. The increased roundedness of the rib cage and horizontal angling of the ribs relative to the spine with age influences the biomechanical response of the thorax. With the plane of the rib oriented more horizontally, loading applied in the anterior-posterior direction will result in increased deformation within the plane of the rib and an increased risk for rib fractures. Thus, morphological changes may be a contributing factor to the increased incidence of rib fractures in the elderly. The morphological functions derived in this study capture substantially more information on thoracic skeleton morphology variation with age and sex than is currently available

  9. Morphometric analysis of variation in the ribs with age and sex

    PubMed Central

    Weaver, Ashley A; Schoell, Samantha L; Stitzel, Joel D

    2014-01-01

    Rib cage morphology changes with age and sex are expected to affect thoracic injury mechanisms and tolerance, particularly for vulnerable populations such as pediatrics and the elderly. The size and shape variation of the external geometry of the ribs was characterized for males and females aged 0–100 years. Computed tomography (CT) scans from 339 subjects were analyzed to collect between 2700 and 10 400 homologous landmarks from each rib. Rib landmarks were analyzed using the geometric morphometric technique known as Procrustes superimposition. Age- and sex-specific functions of 3D rib morphology were produced representing the combined size and shape variation and the isolated shape variation. Statistically significant changes in the size and shape variation (P < 0.0001) and shape variation (P < 0.0053) of all 24 ribs were found to occur with age in males and females. Rib geometry, location, and orientation varied according to the rib level. From birth through adolescence, the rib cage experienced an increase in size, a decrease in thoracic kyphosis, and inferior rotation of the ribs relative to the spine within the sagittal plane. From young adulthood into elderly age, the rib cage experienced increased thoracic kyphosis and superior rotation of the ribs relative to the spine within the sagittal plane. The increased roundedness of the rib cage and horizontal angling of the ribs relative to the spine with age influences the biomechanical response of the thorax. With the plane of the rib oriented more horizontally, loading applied in the anterior-posterior direction will result in increased deformation within the plane of the rib and an increased risk for rib fractures. Thus, morphological changes may be a contributing factor to the increased incidence of rib fractures in the elderly. The morphological functions derived in this study capture substantially more information on thoracic skeleton morphology variation with age and sex than is currently available in

  10. Differential sex- and age-related migration of Bluethroats Luscinia svecica at Eilat, Israel

    NASA Astrophysics Data System (ADS)

    Markovets, Mikhail L.; Zduniak, Piotr; Yosef, Reuven

    2008-07-01

    This paper examines the phenology and biometrics of Bluethroats staging in the Eilat region. This is of special interest because of the extreme conditions with which this temperate zone breeding species has to contend because Eilat is a desert habitat and is the last green area before the crossing of the deserts in autumn or after it in spring. Data were collected during 20 spring and 18 autumn migration seasons in the years 1984-2003, and a total of 7,464 Bluethroat were recorded. The number of trapped birds was much higher in autumn than in spring. The majority of Bluethroats caught in both the autumn and spring migrations were juveniles. We found differences in sex ratio in the individual age classes only in the autumn wherein among both adults and juveniles, males were in greater numbers. We also found significant differences in the dates of ringed birds from different sex-age classes in the spring and in autumn migrations. In spring, males from both age classes were caught earlier than females. In autumn, adult birds arrived earlier than juveniles. We think that it is important to identify and conserve the high quality stopover habitats such as Eilat wherein not only Bluethroats have been shown to stopover but also several hundred other species.

  11. The Effect of Sex and Age on Small Intestinal Transit Times in Humans.

    PubMed

    Fischer, Monika; Fadda, Hala M

    2016-02-01

    This study utilizes a novel approach of small bowel video capsule endoscopy for investigating the influence of sex and age on small intestinal transit times (SITT) in humans. A total of 81 outpatients undergoing investigations with the small bowel video capsule endoscope (SB-VCE) and meeting inclusion criteria were included in this study. Following an overnight fast, patients swallowed the SB-VCE with a glass of water. SITT were calculated from the first duodenal image to the first cecal image. This study showed that the SB-VCE provides accurate and reliable measurements of SITT under real-life conditions. A large inter-individual variability in SITT was observed, with times ranging from 50 to 460 min. This variability can have implications on drug absorption and bioavailability. The median SITT were 219 min for females and 191 min for males. Although SITT were 28 min longer in females than males, this difference was not found to be statistically significant (p = 0.66). No correlation was found between age and SITT (Pearson correlation coefficient 0.19). Therefore, any drug bioavailability differences of modified release dosage preparations that are observed between adult patient groups of different age or sex are unlikely to be attributable to SITT. PMID:26308649

  12. Age, Sex, and Religious Beliefs Impact the Attitude towards Cord Blood Banking.

    PubMed

    Sundell, Inger Birgitta; Setzer, Teddi J

    2015-01-01

    In this study, a self-administered questionnaire was used to assess opinions about stem cell research and cord blood banking. Three attitudes were examined: willingness to accept cord blood banking, willingness to accept embryonic stem cell research, and religious belief system. A total of 90 Wayne State University students enrolled in the study in response to an invitation posted on a web page for the university. Sex distribution among study participants was 79 females and eight males; three declined to state their sex. Support for cord blood banking was high (> 70%) among students. Students over the age of 25 years of age were more (85%) positive than students 18 to 24 years old (57%). They prefered a public cord blood bank over a private cord blood bank. Atheist/agnostic or spiritual/not religious students (> 90%), Catholic students (78%) and Christian students (58%) support cord blood banking. Age, sex and religion seems influence the student's attitude towards stem cell research and cord blood banking. PMID:26665936

  13. A longitudinal analysis of sex differences in math and spatial skills in primary school age children☆

    PubMed Central

    Lachance, Jennifer A.; Mazzocco, Michèle M.M.

    2009-01-01

    We report on a longitudinal study designed to assess possible sex differences in math achievement, math ability, and math-related tasks during the primary school age years. Participants included over 200 children from one public school district. Annual assessments included measures of math ability, math calculation achievement scores, rapid naming and decoding tasks, visual perception tests, visual motor tasks, and reading skills. During select years of the study we also administered tests of counting and math facts skills. We examined whether girls or boys were overrepresented among the bottom or top performers on any of these tasks, relative to their peers, and whether growth rates or predictors of math-related skills differed for boys and girls. Our findings support the notion that sex differences in math are minimal or nonexistent on standardized psychometric tests routinely given in assessments of primary school age children. There was no persistent finding suggesting a male or female advantage in math performance overall, during any single year of the study, or in any one area of math or spatial skills. Growth rates for all skills, and early correlates of later math performance, were comparable for boys and girls. The findings fail to support either persistent or emerging sex differences on non-specialized math ability measures during the primary school age years. PMID:20463851

  14. A longitudinal analysis of sex differences in math and spatial skills in primary school age children.

    PubMed

    Lachance, Jennifer A; Mazzocco, Michèle M M

    2006-01-01

    We report on a longitudinal study designed to assess possible sex differences in math achievement, math ability, and math-related tasks during the primary school age years. Participants included over 200 children from one public school district. Annual assessments included measures of math ability, math calculation achievement scores, rapid naming and decoding tasks, visual perception tests, visual motor tasks, and reading skills. During select years of the study we also administered tests of counting and math facts skills. We examined whether girls or boys were overrepresented among the bottom or top performers on any of these tasks, relative to their peers, and whether growth rates or predictors of math-related skills differed for boys and girls. Our findings support the notion that sex differences in math are minimal or nonexistent on standardized psychometric tests routinely given in assessments of primary school age children. There was no persistent finding suggesting a male or female advantage in math performance overall, during any single year of the study, or in any one area of math or spatial skills. Growth rates for all skills, and early correlates of later math performance, were comparable for boys and girls. The findings fail to support either persistent or emerging sex differences on non-specialized math ability measures during the primary school age years. PMID:20463851

  15. Embryonic temperature and gonadal sex organize male-typical sexual and aggressive behavior in a lizard with temperature-dependent sex determination.

    PubMed

    Rhen, T; Crews, D

    1999-10-01

    Temperature during embryonic development determines gonadal sex in the leopard gecko, Eublepharis macularius. Moreover, both embryonic temperature and gonadal sex influence adult behavior. Yet it remains unclear whether the effects of embryonic temperature and gonadal sex on behavior are irreversibly organized during development. To address this question, we gonadectomized adult females and males generated from a temperature that produces mostly females (30 C) and a temperature that produces mostly males (32.5 C). Females and males from both temperatures were then treated with equivalent levels of various sex steroids. We found that both embryonic temperature and gonadal sex had persistent effects on the expression of male-typical sexual and aggressive behaviors. For example, adult females do not scent mark and display very little courtship and mounting behavior even when treated with levels of hormones (primarily androgens) that activate these behaviors in males. In contrast, species-typical aggressive displays were less sex specific and were activated by both dihydrotestosterone and testosterone (T) in males and by T in females. Nevertheless, the average duration of aggressive displays was significantly shorter in T-treated females than that in T-treated males. With regard to submissive behavior, androgens decreased flight behavior in males, but had no effect in females. Embryonic temperature had enduring effects on certain behaviors in males. For instance, males from a male-biased embryonic temperature scent-marked more than males from a female-biased embryonic temperature when treated with dihydrotestosterone or T. Conversely, and across hormone treatments, males from a female-biased embryonic temperature mounted more than males from a male-biased embryonic temperature. Finally, treatment with 17beta-estradiol decreased submissive behavior in males from a male-biased embryonic temperature compared with that in males from a female-biased embryonic temperature

  16. Variance in age-specific sex composition of Pacific halibut catches, and comparison of statistical and genetic methods for reconstructing sex ratios

    NASA Astrophysics Data System (ADS)

    Loher, Timothy; Woods, Monica A.; Jimenez-Hidalgo, Isadora; Hauser, Lorenz

    2016-01-01

    Declines in size at age of Pacific halibut Hippoglossus stenolepis, in concert with sexually-dimorphic growth and a constant minimum commercial size limit, have led to the expectation that the sex composition of commercial catches should be increasingly female-biased. Sensitivity analyses suggest that variance in sex composition of landings may be the most influential source of uncertainty affecting current understanding of spawning stock biomass. However, there is no reliable way to determine sex at landing because all halibut are eviscerated at sea. In 2014, a statistical method based on survey data was developed to estimate the probability that fish of any given length at age (LAA) would be female, derived from the fundamental observation that large, young fish are likely female whereas small, old fish have a high probability of being male. Here, we examine variability in age-specific sex composition using at-sea commercial and closed-season survey catches, and compare the accuracy of the survey-based LAA technique to genetic markers for reconstructing the sex composition of catches. Sexing by LAA performed best for summer-collected samples, consistent with the hypothesis that the ability to characterize catches can be influenced by seasonal demographic shifts. Additionally, differences between survey and commercial selectivity that allow fishers to harvest larger fish within cohorts may generate important mismatch between survey and commercial datasets. Length-at-age-based estimates ranged from 4.7% underestimation of female proportion to 12.0% overestimation, with mean error of 5.8 ± 1.5%. Ratios determined by genetics were closer to true sample proportions and displayed less variability; estimation to within < 1% of true ratios was limited to genetics. Genetic estimation of female proportions ranged from 4.9% underestimation to 2.5% overestimation, with a mean absolute error of 1.2 ± 1.2%. Males were generally more difficult to assign than females: 6.7% of

  17. Effects of α-zearalanol on spermatogenesis and sex hormone levels of male mice

    PubMed Central

    Bo, Cunxiang; Zhao, Wei; Jia, Qiang; Yang, Zhifeng; Sai, Linlin; Zhang, Fang; Du, Zhongjun; Yu, Gongchang; Xie, Lin; Zhang, Zhenling

    2015-01-01

    Aims: To investigate the mechanisms of α-zearalanol (Zeranol)-induced male reproductive toxicity, the effects of Zeranol on spermatogenesis and sex hormone levels of male mice were studied. Methods: Forty healthy sexually mature male Kunming mice were randomly divided into four groups. The mice were mock-treated or treated with Zeranol 25, 50 or 100 mg/kg via oral gavage for 35 days. The epididymal sperms were counted and their morphology and motility were analyzed. The testicles were examined by light and electron microscopy. The levels of serum/testicular testosterone (T), serum follicle stimulating hormone (FSH) and serum luteinizing hormone (LH) were determined by radioimmunoassay. Results: Zeranol decreased the epididymal sperm count and sperm motility in a dose depend manner. While there were not significant differences in the sperm malformation rates between the Zeranol treated groups and the control group. Furthermore, Zeranol could decrease the weight and the organ coefficient of the seminal vesicles and the testicles and lead to significant pathological changes of the testicles. Zeranol could also decrease the levels of serum T, FSH, LH as well as the levels of testicular T of male mice. Conclusions: Zeranol induced reproductive toxicity in adult male mice. It could damage spermatogenesis via its direct effects on the testicles and interfere with sex hormone levels of male mice through its effects on the hypothalamic-pituitary-testicular axis. PMID:26884912

  18. Sex differences in cognitive ageing: testing predictions derived from life-history theory in a dioecious nematode.

    PubMed

    Zwoinska, Martyna K; Kolm, Niclas; Maklakov, Alexei A

    2013-12-01

    Life-history theory maintains that organisms allocate limited resources to different traits to maximize fitness. Learning ability and memory are costly and known to trade-off with longevity in invertebrates. However, since the relationship between longevity and fitness often differs between the sexes, it is likely that sexes will differentially resolve the trade-off between learning and longevity. We used an established associative learning paradigm in the dioecious nematode Caenorhabditis remanei, which is sexually dimorphic for lifespan, to study age-related learning ability in males and females. In particular, we tested the hypothesis that females (the shorter-lived sex) show higher learning ability than males early in life but senesce faster. Indeed, young females outperformed young males in learning a novel association between an odour (butanone) and food (bacteria). However, while learning ability and offspring production declined rapidly with age in females, males maintained high levels of these traits until mid-age. These results not only demonstrate sexual dimorphism in age-related learning ability but also suggest that it conforms to predictions derived from the life-history theory. PMID:24120565

  19. Apolipoprotein E and Sex Bias in Cerebrovascular Aging of Men and Mice.

    PubMed

    Finch, Caleb E; Shams, Sara

    2016-09-01

    Alzheimer disease (AD) research has mainly focused on neurodegenerative processes associated with the classic neuropathologic markers of senile plaques and neurofibrillary tangles. Additionally, cerebrovascular contributions to dementia are increasingly recognized, particularly from cerebral small vessel disease (SVD). Remarkably, in AD brains, the apolipoprotein E (ApoE) ɛ4 allele shows male excess for cerebral microbleeds (CMBs), a marker of SVD, which is opposite to the female excess of plaques and tangles. Mouse transgenic models add further complexities to sex-ApoE ɛ4 allele interactions, with female excess of both CMBs and brain amyloid. We conclude that brain aging and AD pathogenesis cannot be understood in humans without addressing major gaps in the extent of sex differences in cerebrovascular pathology. PMID:27546867

  20. Sex differences with aging in the fatigability of dynamic contractions.

    PubMed

    Yoon, Tejin; Doyel, Ryan; Widule, Claire; Hunter, Sandra K

    2015-10-01

    This study determined the sex difference with aging in fatigability of the elbow flexor muscles during a dynamic fatiguing task, and explored the associated mechanisms. We compared fatigability of the elbow flexor muscles in 18 young (20.2 ± 1 years: 9 men) and 36 old adults (73.5 ± 1 years: 16 men) during and in recovery from repeated dynamic contractions (~60°/s) with a load equivalent to 20% of maximal voluntary isometric contraction (MVIC) torque until failure. Transcranial magnetic stimulation (TMS) was used to assess supraspinal fatigue (an increase in the superimposed twitch, SIT) and the peak rate of muscle relaxation. Time to failure was briefer for the men than the women (6.1 ± 2.1 vs. 9.7 ± 5.5 min, respectively; P=0.02) with no difference between young and old adults (7.2 ± 2.9 vs. 8.4 ± 5.2 min, respectively, P=0.45) and no interaction (P>0.05). The relative decline in peak relaxation rate with fatigability was similar for young and old adults (P=0.11), but greater for men than women (P=0.046). Supraspinal fatigue increased for all groups and was associated with the time to failure (P<0.05). Regression analysis however, indicated that the time to failure was best predicted by the peak relaxation rate (baseline values and slowing with fatigability) (r(2)=0.55). Rate-limiting contractile mechanisms (e.g. excitation-contraction coupling) were responsible for the increased fatigability of the elbow flexors of men compared with women for a dynamic fatiguing task of slow angular velocity, and this sex difference was maintained with aging. The age difference in fatigability for the dynamic task was diminished for both sexes relative to what is typically observed with isometric fatiguing contractions. PMID:26159162

  1. Experience-independent sex differences in newborn macaques: Females are more social than males

    PubMed Central

    Simpson, Elizabeth A.; Nicolini, Ylenia; Shetler, Melissa; Suomi, Stephen J.; Ferrari, Pier F.; Paukner, Annika

    2016-01-01

    Human females exhibit greater social interest and skills relative to males, appearing in infancy, suggesting biological roots; however, male and female infants may be treated differently, potentially causing or amplifying sex differences. Here, we tested whether sex differences in social motivation emerge in infant monkeys (n = 48) reared in a controlled postnatal environment. Compared to males, females at 2–3 weeks looked more at conspecifics’ faces (d = 0.65), especially the eyes (d = 1.09), and at 4–5 weeks exhibited more affiliative behaviors (d = 0.64), including gesturing, looking, and proximity to familiar and unfamiliar human caretakers. In sum, converging evidence from humans and monkeys suggests that female infants are more social than males in the first weeks of life, and that such differences may arise independent of postnatal experience. Individual differences in social interest have wide-ranging developmental consequences, impacting infants’ social interaction quality and opportunities for learning. Understanding the evolution of sex differences and their developmental emergence is necessary to best support infants with varying levels of sociality. PMID:26794858

  2. Hombre Seguro (Safe Men): a sexual risk reduction intervention for male clients of female sex workers

    PubMed Central

    2014-01-01

    Background Male clients of female sex workers (FSWs) are at risk of HIV and other sexually transmitted infections (STIs). We conducted a two-arm randomized controlled trial to test the efficacy of a sexual risk reduction intervention for male clients of FSWs in Tijuana, Mexico. Methods/Design Male clients of FSWs who were at least 18, were HIV-negative at baseline, and reported recent unprotected sex with FSWs were randomized to the Hombre Seguro sexual risk reduction intervention, or a time-attention didactic control condition. Each condition lasted approximately one hour. Participants underwent interviewer-administered surveys and testing for HIV and other STIs at baseline, and at 4, 8, and 12 month follow-ups. Combined HIV/STI incidence and unprotected vaginal and anal sex acts with FSWs were the primary outcomes. Discussion A total of 400 participants were randomized to one of the two conditions. Analyses indicated that randomization was successful; there were no significant differences between the participants in the two conditions at baseline. Average follow-up was 84% across both conditions. This is the first study to test the efficacy of a sexual risk reduction intervention for male clients of FSWs using the rigor of a randomized controlled trial. Trial registration NCT01280838, Date of registration: January 19, 2011. PMID:24885949

  3. Experience-independent sex differences in newborn macaques: Females are more social than males.

    PubMed

    Simpson, Elizabeth A; Nicolini, Ylenia; Shetler, Melissa; Suomi, Stephen J; Ferrari, Pier F; Paukner, Annika

    2016-01-01

    Human females exhibit greater social interest and skills relative to males, appearing in infancy, suggesting biological roots; however, male and female infants may be treated differently, potentially causing or amplifying sex differences. Here, we tested whether sex differences in social motivation emerge in infant monkeys (n = 48) reared in a controlled postnatal environment. Compared to males, females at 2-3 weeks looked more at conspecifics' faces (d = 0.65), especially the eyes (d = 1.09), and at 4-5 weeks exhibited more affiliative behaviors (d = 0.64), including gesturing, looking, and proximity to familiar and unfamiliar human caretakers. In sum, converging evidence from humans and monkeys suggests that female infants are more social than males in the first weeks of life, and that such differences may arise independent of postnatal experience. Individual differences in social interest have wide-ranging developmental consequences, impacting infants' social interaction quality and opportunities for learning. Understanding the evolution of sex differences and their developmental emergence is necessary to best support infants with varying levels of sociality. PMID:26794858

  4. Influence of personality, age, sex, and estrous state on chimpanzee problem-solving success

    PubMed Central

    Hopper, Lydia M.; Price, Sara A.; Freeman, Hani D.; Lambeth, Susan P.; Schapiro, Steven J.

    2015-01-01

    Despite the importance of individual problem solvers for group- and individual-level fitness, the correlates of individual problem-solving success are still an open topic of investigation. In addition to demographic factors, such as age or sex, certain personality dimensions have also been revealed as reliable correlates of problem-solving by animals. Such correlates, however, have been little-studied in chimpanzees. To empirically test the influence of age, sex, estrous state, and different personality factors on chimpanzee problem-solving, we individually tested 36 captive chimpanzees with two novel foraging puzzles. We included both female (N = 24) and male (N = 12) adult chimpanzees (aged 14–47 years) in our sample. We also controlled for the females’ estrous state—a potential influence on cognitive reasoning—by testing cycling females both when their sexual swelling was maximally tumescent (associated with the luteinizing hormone surge of a female’s estrous cycle) and again when it was detumescent. Although we found no correlation between the chimpanzees’ success with either puzzle and their age or sex, the chimpanzees’ personality ratings did correlate with responses to the novel foraging puzzles. Specifically, male chimpanzees that were rated highly on the factors Methodical, Openness (to experience), and Dominance spent longer interacting with the puzzles. There was also a positive relationship between the latency of females to begin interacting with the two tasks and their rating on the factor Reactivity/Undependability. No other significant correlations were found, but we report tentative evidence for increased problem-solving success by the females when they had detumescent estrous swellings. PMID:24322874

  5. Acoustic features of male baboon loud calls: Influences of context, age, and individuality

    NASA Astrophysics Data System (ADS)

    Fischer, Julia; Hammerschmidt, Kurt; Cheney, Dorothy L.; Seyfarth, Robert M.

    2002-03-01

    The acoustic structure of loud calls (``wahoos'') recorded from free-ranging male baboons (Papio cynocephalus ursinus) in the Moremi Game Reserve, Botswana, was examined for differences between and within contexts, using calls given in response to predators (alarm wahoos), during male contests (contest wahoos), and when a male had become separated from the group (contact wahoos). Calls were recorded from adolescent, subadult, and adult males. In addition, male alarm calls were compared with those recorded from females. Despite their superficial acoustic similarity, the analysis revealed a number of significant differences between alarm, contest, and contact wahoos. Contest wahoos are given at a much higher rate, exhibit lower frequency characteristics, have a longer ``hoo'' duration, and a relatively louder ``hoo'' portion than alarm wahoos. Contact wahoos are acoustically similar to contest wahoos, but are given at a much lower rate. Both alarm and contest wahoos also exhibit significant differences among individuals. Some of the acoustic features that vary in relation to age and sex presumably reflect differences in body size, whereas others are possibly related to male stamina and endurance. The finding that calls serving markedly different functions constitute variants of the same general call type suggests that the vocal production in nonhuman primates is evolutionarily constrained.

  6. Brain levels of sex steroid hormones in men and women during normal aging and in Alzheimer’s disease

    PubMed Central

    Rosario, Emily R.; Chang, Lilly; Head, Elizabeth H.; Stanczyk, Frank Z.; Pike, Christian J.

    2009-01-01

    We examined the relationships between normal aging, Alzheimer’s disease (AD), and brain levels of sex steroid hormones in men and women. In postmortem brain tissue from neuropathologically normal, postmenopausal women, we found no age-related changes in brain levels of either androgens or estrogens. In comparing women with and without AD at different ages, brain levels of estrogens and androgens were lower in AD cases aged 80 years and older but not significantly different in the 60–79 year age range. In male brains, we observed that normal aging was associated with significant decreases in androgens but not estrogens. Further, in men aged 60–79 years, brain levels of testosterone but not estrogens were lower in cases with mild neuropathological changes as well as those with advanced AD neuropathology. In male cases over age 80, brain levels hormones did not significantly vary by neuropathological status. To begin investigating the relationships between hormone levels and indices of AD neuropathology, we measured brain levels of soluble β-amyloid (Aβ). In male cases with mild neuropathological changes, we found an inverse relationship between brain levels of testosterone and soluble Aβ. Collectively, these findings demonstrate sex-specific relationships between normal, age-related depletion of androgens and estrogens in men and women, which may be relevant to development of AD. PMID:19428144

  7. Prenatal cocaine exposure decreases nigrostriatal dopamine release in vitro: effects of age and sex.

    PubMed

    Glatt, Stephen J; Trksak, George H; Cohen, Ori S; Simeone, Benjamin P; Jackson, Denise

    2004-08-01

    The present study examined the effects of prenatal cocaine (PCOC) exposure, age, sex, and estrous phase on the functional development of nigrostriatal dopamine (DA) neurons. Striatal tissue was obtained from prepubescent and adult rats of both sexes after bidaily exposure to saline (1 ml/kg) or cocaine (20 mg/kg/ml saline) from embryonic days 15-21. Tissue levels, basal release, and electrically evoked (1 or 8 Hz) overflow of endogenous DA and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), as well as their efflux in response to superfusion with the DA transport blocker, nomifensine (10 microM), were measured from superfused striatal slices. Generally, these measures were highest in tissue from males and adults. Tissue DA and DOPAC levels and the rate of DA turnover were unaffected by PCOC exposure. Slices from PCOC-exposed juvenile and adult male rats exhibited significantly reduced basal and electrically evoked DA release at both stimulation intensities, in conjunction with higher levels of presynaptic DA reuptake. Female rats were largely spared from the effects of PCOC exposure, and measures did not vary with estrous phase. These findings demonstrate that the effects of PCOC exposure on various parameters of nigrostriatal DA neuronal function are not uniform across age, sex, or phases of the estrous cycle. These novel alterations in nigrostriatal DA transmission are in need of independent replication, but they may have profound implications for behavioral activities regulated by these neurons and, thus, may provide a basis for sex-selective effects of PCOC in exposed humans. Possible mechanisms of deleterious effects of PCOC exposure in select groups are discussed. PMID:15170820

  8. Effects of aging on the male reproductive system.

    PubMed

    Gunes, Sezgin; Hekim, Gulgez Neslihan Taskurt; Arslan, Mehmet Alper; Asci, Ramazan

    2016-04-01

    The study aims to discuss the effects of aging on the male reproductive system. A systematic review was performed using PubMed from 1980 to 2014. Aging is a natural process comprising of irreversible changes due to a myriad of endogenous and environmental factors at the level of all organs and systems. In modern life, as more couples choose to postpone having a child due to various socioeconomic reasons, research for understanding the effects of aging on the reproductive system has gained an increased importance. Paternal aging also causes genetic and epigenetic changes in spermatozoa, which impair male reproductive functions through their adverse effects on sperm quality and count as, well as, on sexual organs and the hypothalamic-pituitary-gonadal axis. Hormone production, spermatogenesis, and testes undergo changes as a man ages. These small changes lead to decrease in both the quality and quantity of spermatozoa. The offspring of older fathers show high prevalence of genetic abnormalities, childhood cancers, and several neuropsychiatric disorders. In addition, the latest advances in assisted reproductive techniques give older men a chance to have a child even with poor semen parameters. Further studies should investigate the onset of gonadal senesce and its effects on aging men. PMID:26867640

  9. HIV and STI Prevalence and Risk Factors Among Male Sex Workers and Other Men Who Have Sex With Men in Nairobi, Kenya

    PubMed Central

    Muraguri, Nicholas; Tun, Waimar; Okal, Jerry; Broz, Dita; Raymond, H. Fisher; Kellogg, Timothy; Dadabhai, Sufia; Musyoki, Helgar; Sheehy, Meredith; Kuria, David; Kaiser, Reinhard; Geibel, Scott

    2016-01-01

    Previous surveys of men who have sex with men (MSM) in Africa have not adequately profiled HIV status and risk factors by sex work status. MSM in Nairobi, Kenya, were recruited using respondent-driven sampling, completed a behavioral interview, and were tested for HIV and sexually transmitted infections. Overlapping recruitment among 273 male sex workers and 290 other MSM was common. Sex workers were more likely to report receptive anal sex with multiple partners (65.7% versus 18.0%, P < 0.001) and unprotected receptive anal intercourse (40.0% versus 22.8%, P = 0.005). Male sex workers were also more likely to be HIV infected (26.3% versus 12.2%, P = 0.007). PMID:25501346

  10. HIV and STI prevalence and risk factors among male sex workers and other men who have sex with men in Nairobi, Kenya.

    PubMed

    Muraguri, Nicholas; Tun, Waimar; Okal, Jerry; Broz, Dita; Raymond, H Fisher; Kellogg, Timothy; Dadabhai, Sufia; Musyoki, Helgar; Sheehy, Meredith; Kuria, David; Kaiser, Reinhard; Geibel, Scott

    2015-01-01

    : Previous surveys of men who have sex with men (MSM) in Africa have not adequately profiled HIV status and risk factors by sex work status. MSM in Nairobi, Kenya, were recruited using respondent-driven sampling, completed a behavioral interview, and were tested for HIV and sexually transmitted infections. Overlapping recruitment among 273 male sex workers and 290 other MSM was common. Sex workers were more likely to report receptive anal sex with multiple partners (65.7% versus 18.0%, P < 0.001) and unprotected receptive anal intercourse (40.0% versus 22.8%, P = 0.005). Male sex workers were also more likely to be HIV infected (26.3% versus 12.2%, P = 0.007). PMID:25501346

  11. An exploratory study of HIV risk behaviours and testing among male sex workers in Beirut, Lebanon

    PubMed Central

    Aunon, Frances M.; Wagner, Glenn J.; Maher, Rabih; Khouri, Danielle; Kaplan, Rachel L.; Mokhbat, Jacques

    2015-01-01

    Male sex workers (MSW) are a particularly high-risk subset of men who have sex with men in Lebanon and report higher numbers of sex partners and lower rates of condom use. The purpose was to explore the factors influencing sexual risk behaviors and HIV testing among MSW. Qualitative interviews were conducted with 16 MSW living in Beirut and working in bathhouses (hammam) or as escorts; content analysis identified emergent themes. Escorts reported more consistent condom use with clients and HIV testing than hammam MSW, with influential factors including HIV risk knowledge and perceived risk susceptibility, job security, and internalized stigma and related feelings of self-worth and fatalism regarding health and HIV risk. In contrast, both groups of MSW typically opted not to condoms with nonclient sex partners, in an effort to differentiate sex for work versus pleasure. The uptake of HIV testing was limited by concerns about the confidentiality of the test results and fear of repercussions of a positive test result for their health and employment. The respondents described an insular existence within the sex work culture, in part to limit exposure to stigma, which has implications for access to support as well as the influence of peer norms regarding sexual risk behavior and health seeking behaviors such as HIV testing. Further research is needed to tailor prevention and HIV testing efforts to reflect the distinct sexual health “cultures” that distinguish these two populations of MSW in Lebanon. PMID:25950906

  12. An Exploratory Study of HIV Risk Behaviors and Testing among Male Sex Workers in Beirut, Lebanon.

    PubMed

    Aunon, Frances M; Wagner, Glenn J; Maher, Rabih; Khouri, Danielle; Kaplan, Rachel L; Mokhbat, Jacques

    2015-01-01

    Male sex workers (MSW) are a particularly high-risk subset of men who have sex with men in Lebanon and report higher numbers of sex partners and lower rates of condom use. The purpose was to explore the factors influencing sexual risk behaviors and HIV testing among MSW. Qualitative interviews were conducted with 16 MSW living in Beirut and working in bathhouses (hammam) or as escorts; content analysis identified emergent themes. Escorts reported more consistent condom use with clients and HIV testing than hammam MSW, with influential factors including HIV risk knowledge and perceived risk susceptibility, job security, and internalized stigma and related feelings of self-worth and fatalism regarding health and HIV risk. In contrast, both groups of MSW typically opted not to condoms with nonclient sex partners, in an effort to differentiate sex for work versus pleasure. The uptake of HIV testing was limited by concerns about the confidentiality of the test results and fear of repercussions of a positive test result for their health and employment. The respondents described an insular existence within the sex work culture, in part to limit exposure to stigma, which has implications for access to support as well as the influence of peer norms regarding sexual risk behavior and health seeking behaviors such as HIV testing. Further research is needed to tailor prevention and HIV testing efforts to reflect the distinct sexual health "cultures" that distinguish these two populations of MSW in Lebanon. PMID:25950906

  13. Sex differences in age-related changes on peripheral warm and cold innocuous thermal sensitivity.

    PubMed

    Inoue, Yoshimitsu; Gerrett, Nicola; Ichinose-Kuwahara, Tomoko; Umino, Yasue; Kiuchi, Saeko; Amano, Tatsuro; Ueda, Hiroyuki; Havenith, George; Kondo, Narihiko

    2016-10-01

    Cutaneous thermal sensitivity to a warm and cold stimulus was compared amongst 12 older (OF, 65.2±1.0year) and 29 younger (YF, 21.6±0.2years) female participants, and 17 older (OM, 66.2±1.5years) and 13 younger (YM, 21.2±0.4years) male participants to examine the effects of ageing and sex. In a neutral condition (27.5°C, 50% RH) during rest, warm and cold thermal sensitivity was measured on eight body regions (forehead, chest, back, forearm, hand, thigh, calf, and foot). Using the method of limits, a thermal stimulator was applied to the skin at an adapting temperature and either increased or decreased at a constant rate (0.3°C/s) until the participants detected the temperature with a push button. Thermal sensitivity declined with ageing to both a cold (older: 1468.6±744.7W/m(2), younger: 869.8±654.7W/m(2), p<0.001) and warm (older: 2127.0±1208.3W/m(2), younger: 1301.7±1055.2W/m(2), p<0.001) innocuous stimulus. YF and OF were more sensitive than YM and OM to both a warm and cold stimulus (p<0.05). There was no interaction between age and sex suggesting that whilst thermal sensitivity decreases with age the decrease is similar between the sexes (p>0.05). There was an interaction between temperatures, age and location and it seemed that cold thermal sensitivity was more homogenous for young and older participants however warm thermal sensitivity was more heterogeneous especially in the younger participants (p<0.05). Although the pattern was not similar between ages or sexes it was evident that the forehead was the most sensitive region to a warm and cold stimulus. Interestingly the decline in sensitivity observed with ageing occurred for all locations but was attenuated at the forehead in both males and females (p>0.05). PMID:27237043

  14. Characteristics of sex partners and sexual partnership correlates of inconsistent condom use among male injection drug users in India.

    PubMed

    Tun, Waimar; Bhattacharya, Aruna; Apicella, Louis; Shasikumar Singh, Yumnam; Lewis, Dean

    2014-07-01

    Previous studies have established the risky behaviors of IDUs in India, and that IDUs are sexually active; however, there is a need to better understand the nature of sexual partnerships of IDUs. A total of 783 (Delhi) and 766 (Imphal) male IDUs were recruited into the study through respondent-driven sampling. We examined characteristics of sex partners of male IDUs and individual and sexual partnership characteristics associated with unprotected sex in Delhi and Imphal. While 16.8% of sexual partnerships in Delhi were male-to-male, there were almost no male-to-male partnerships in Imphal. The majority of partners of male IDUs in Delhi (82.5%) and Imphal (92.3%) do not inject drugs, with the exception of male partners of male IDUs in Delhi. Commercial partners (females: 58.3%; males: 71.3%) were the most common type of sex partners of male IDUs in Delhi, while regular partners (65.2%) were the most common type of sex partners in Imphal. In Delhi, characteristics of sex partners significantly associated with unprotected sex were being male/transgender (AOR 2.2; 95% CI: 1.2-4.0), being a regular (AOR 5.1; 95% CI: 2.8-9.4) or non-regular partner (AOR 2.7; 95% CI: 1.7- 4.5), and sharing needles/syringes with the index IDU (AOR 2.8; 95% CI: 1.4-5.3). In Imphal, partner characteristics associated with unprotected sex were being a regular (AOR 10.1; 95% CI: 41-25.1) or non-regular partner (AOR 3.4; 95% CI: 1.5-7.6), and living outside of town or state (AOR 3.3; 95% CI: 1.2-9.6). Enhanced understanding of disassortative sexual mixing and context of unprotected sex within sexual partnerships may enhance sexual risk reduction interventions for IDUs. PMID:25427360

  15. Evidence of female-produced sex pheromone of Adelphocoris suturalis (Hemiptera: Miridae): effect of age and time of day.

    PubMed

    Zhang, Zhilin; Luo, Jing; Lu, Chong; Zhao, Bo; Meng, Juan; Chen, Lizhen; Lei, Chaoliang

    2011-08-01

    After the reduction in the use of broad-spectrum insecticides, Adelphocoris suturalis (Hemiptera: Miridae) has become an important pest of transgenic cotton, Gossypium hirsutum L., in China. A. suturalis is a highly mobile insect, moving rapidly in and out of crop fields, and traps baited with sex pheromones may be useful in monitoring and controlling its numbers. However, little is currently known regarding the chemical communication based on sex pheromones by this species. To use the synthesized sex pheromone effectively as part of the integrated pest management, some fundamental biological parameters under which the pheromone is produced must be understood. In this study, attractiveness of adult females or males of A. suturalis to conspecific individuals was examined by Y-tube bioassay; we also investigated the female sexually mature age and circadian rhythm of male attraction to females of A. suturalis in the field in 2008 and 2010. Y-tube bioassay results indicated that only males were attracted to odors from sexually mature virgin females. Two-year field trapping experiments showed that 4-18-d-old virgin females effectively attracted males, and males were attracted to virgin females during the scotophase, with a peak between 1900 and 2300 hours. These results improve our understanding of the sexual communication behavior of A. suturalis and provide evidence of female-produced sex pheromone in this species. PMID:21882682

  16. Cisgender male and transgender female sex workers in South Africa: gender variant identities and narratives of exclusion.

    PubMed

    Samudzi, Zoe; Mannell, Jenevieve

    2016-01-01

    Sex workers are often perceived as possessing 'deviant' identities, contributing to their exclusion from health services. The literature on sex worker identities in relation to health has focused primarily on cisgender female sex workers as the 'carriers of disease', obscuring the experiences of cisgender male and transgender sex workers and the complexities their gender identities bring to understandings of stigma and exclusion. To address this gap, this study draws on 21 interviews with cisgender male and transgender female sex workers receiving services from the Sex Workers Education and Advocacy Taskforce in Cape Town, South Africa. Our findings suggest that the social identities imposed upon sex workers contribute to their exclusion from public, private, discursive and geographic spaces. While many transgender female sex workers described their identities using positive and empowered language, cisgender male sex workers frequently expressed shame and internalised stigma related to identities, which could be described as 'less than masculine'. While many of those interviewed felt empowered by positive identities as transgender women, sex workers and sex worker-advocates, disempowerment and vulnerability were also linked to inappropriately masculinised and feminised identities. Understanding the links between gender identities and social exclusion is crucial to creating effective health interventions for both cisgender men and transgender women in sex work. PMID:26242843

  17. Age-related sex differences in language lateralization: A magnetoencephalography study in children.

    PubMed

    Yu, Vickie Y; MacDonald, Matt J; Oh, Anna; Hua, Gordon N; De Nil, Luc F; Pang, Elizabeth W

    2014-09-01

    It is well supported by behavioral and neuroimaging studies that typical language function is lateralized to the left hemisphere in the adult brain and this laterality is less well defined in children. The behavioral literature suggests there maybe be sex differences in language development, but this has not been examined systematically with neuroimaging. In this study, magnetoencephalography was used to investigate the spatiotemporal patterns of language lateralization as a function of age and sex. Eighty typically developing children (46 female, 34 male; 4-18 years) participated in an overt visual verb generation task. An analysis method called differential beamforming was used to analyze language-related changes in oscillatory activity referred to as low-gamma event-related desynchrony (ERD). The proportion of ERD over language areas relative to total ERD was calculated. We found different patterns of laterality between boys and girls. Boys showed left-hemisphere lateralization in the frontal and temporal language-related areas across age groups, whereas girls showed a more bilateral pattern, particularly in frontal language-related areas. Differences in patterns of ERD were most striking between boys and girls in the younger age groups, and these patterns became more similar with increasing age, specifically in the preteen years. Our findings show sex differences in language lateralization during childhood; however, these differences do not seem to persist into adulthood. We present possible explanations for these differences. We also discuss the implications of these findings for presurgical language mapping in children and highlight the importance of examining the question of sex-related language differences across development. PMID:25069054

  18. Odour-Mediated Orientation of Beetles Is Influenced by Age, Sex and Morph

    PubMed Central

    Arnold, Sarah E. J.; Stevenson, Philip C.; Belmain, Steven R.

    2012-01-01

    The behaviour of insects is dictated by a combination of factors and may vary considerably between individuals, but small insects are often considered en masse and thus these differences can be overlooked. For example, the cowpea bruchid Callosobruchus maculatus F. exists naturally in two adult forms: the active (flight) form for dispersal, and the inactive (flightless), more fecund but shorter-lived form. Given that these morphs show dissimilar biology, it is possible that they differ in odour-mediated orientation and yet studies of this species frequently neglect to distinguish morph type, or are carried out only on the inactive morph. Along with sex and age of individual, adult morph could be an important variable determining the biology of this and similar species, informing studies on evolution, ecology and pest management. We used an olfactometer with motion-tracking to investigate whether the olfactory behaviour and orientation of C. maculatus towards infested and uninfested cowpeas and a plant-derived repellent compound, methyl salicylate, differed between morphs or sexes. We found significant differences between the behaviour of male and female beetles and beetles of different ages, as well as interactive effects of sex, morph and age, in response to both host and repellent odours. This study demonstrates that behavioural experiments on insects should control for sex and age, while also considering differences between adult morphs where present in insect species. This finding has broad implications for fundamental entomological research, particularly when exploring the relationships between physiology, behaviour and evolutionary biology, and the application of crop protection strategies. PMID:23145074

  19. Intensity-dependent effect of ageing on fatigue during intermittent contractions of the human calf muscle in males and females.

    PubMed

    Reilly, Heather; Egana, Mikel; Green, Simon

    2015-09-01

    Ageing reduces fatigue during submaximal intermittent contractions, but the influence of intensity on this ageing effect in males and females is not clear. Younger males (n = 8; 23 ± 2 years), younger females (n = 8; 22 ± 1 years), older males (n = 8; 67 ± 5 years) and older females (n = 10; 64 ± 7 years) completed intermittent calf contractions at four submaximal intensities (30-70 %MVC) for up to 20 min. MVC was assessed during exercise at 30-60 s intervals and its linear rate of decline represented fatigue. Individual relationships between intensity and fatigue (%MVC min(-1)) were fitted to a biphasic function consisting of a linear and nonlinear component. There was no age × sex × intensity interaction for fatigue (3-way ANOVA, P = 0.46). However, there were significant interactive effects of age and sex on endurance at 70 %MVC, fatigue at 70 %MVC and the linear component of the intensity-fatigue relationship. Endurance was lower and fatigue and its linear component were greater (P < 0.05) in younger males compared with other groups, but not different between younger and older females. This suggests that there is an intensity-dependent effect of human ageing on fatigue during submaximal exercise that is specific to males. PMID:25911632

  20. Relationship of oral cancer with age, sex, site distribution and habits.

    PubMed

    Patel, Mandakini Mansukh; Pandya, Amrish N

    2004-04-01

    Many studies are carried out regarding age incidence, tobacco smoking and sites of oral cancer, but in Gujarat tobacco chewing in form of Gutkha is more common than smoking and start during preteen years. Tobacco chewing causing chronic inflammation, submucous fibrosis and oral cancer. This study was conducted on 504 patients to find out if there is increasing incidence of oral cancer in lower age group and its relation with sex as well which site was commonly affected. There was statistically significant increase in oral cancer in lower age group, and anatomically anterior part of oral cavity showed involvement in 61.32% of cases. Though males were affected more but female cases were 25%. So tobacco chewing has got detrimental effect on oral cavity. PMID:16295466

  1. Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps.

    PubMed

    Diao, Wenwen; Mousset, Mathilde; Horsburgh, Gavin J; Vermeulen, Cornelis J; Johannes, Frank; van de Zande, Louis; Ritchie, Michael G; Schmitt, Thomas; Beukeboom, Leo W

    2016-01-01

    A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences. PMID:27172207

  2. Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps

    PubMed Central

    Diao, Wenwen; Mousset, Mathilde; Horsburgh, Gavin J.; Vermeulen, Cornelis J.; Johannes, Frank; van de Zande, Louis; Ritchie, Michael G.; Schmitt, Thomas; Beukeboom, Leo W.

    2016-01-01

    A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences. PMID:27172207

  3. A Sex-Linked Gene Controlling the Onset of Sexual Maturity in Female and Male Platyfish (XIPHOPHORUS MACULATUS), Fecundity in Females and Adult Size in Males

    PubMed Central

    Kallman, Klaus D.; Borkoski, Valerie

    1978-01-01

    A sex-linked gene, P, controls the onset of sexual maturity in the platyfish, Xiphophorus maculatus. The activity of this gene is correlated with the age and size at which the gonadotropic zone of the adenohypophysis differentiates and becomes physiologically active. Immature fish of all genotypes grow at the same rate; however, as adults, males with "early" genotypes are significantly smaller than males of "late" genotypes, since growth rate declines strongly under the influence of androgenic hormone. Five alleles, P1... P5, have been identified from natural populations that under controlled conditions cause gonad maturation between eight and 73 weeks. P1P1 males become mature at eight weeks and 21 mm, P2P2 and P3P3 males between eleven and 13.5 weeks and 25 to 29 mm, and P4P4 males at 25 weeks and 37 mm. Since P5 is X-linked, no males homozygous for P5 could be produced. The difference between P2 and P3 is largely based upon their interaction with P5. P3P5 males mature at 17.5 weeks and 33.5 mm and P2P5 males at 28 weeks and 38 mm. The rate of transformation of the unmodified anal fin into a gonopodium, which is under androgenic control, is directly related to the age at initiation of sexual maturity, ranging from 3.2 weeks in P1P1 males to seven weeks in P2P 5 males. These differences may reflect different levels of circulating gonadotropic and androgenic hormones.—In two genotypes of females, initiation of vitellogenesis was closely correlated with size and this critical size was independent of age (e.g., 21 mm for P1P1 ). In a third genotype (P1P5) the minimum size for vitellogenesis decreased with increasing age, so that females would mature as early as eleven weeks, provided they had attained at least 29 mm, but at 25 weeks even females as small as 23 mm possessed ripe gonads. For P5P5 females, which become mature between 34 and 73 weeks of age, there is no correlation between size and initiation of vitellogenesis. In all four genotypes of females examined

  4. Sex steroid and prolactin profiles in male American black bears (Ursus americanus) during denning.

    PubMed

    Tsubota, T; Garshelis, D L; Nelson, R A; Bahr, J M

    1999-01-01

    Serum sex steroid and prolactin profiles were examined in the male American black bear, Ursus americanus during denning. Sera collected in December and the following March from 8 denning male black bears in Minnesota, U.S.A. were assayed for testosterone, estradiol-17 beta and prolactin. Eight bears were confirmed to be the denning mode based on a serum urea to creatinine ratio less than 10. Serum testosterone concentrations tended to increase from December to the subsequent March whereas serum estradiol-17 beta concentrations tended to decrease during this period. There were few changes in serum prolactin concentrations between December and March. These findings suggest that spermatogenesis and testicular steroidogenesis initiated during denning may be influenced by changes in serum sex steroid concentrations in the American black bear. PMID:10027172

  5. Selection on male sex pheromone composition contributes to butterfly reproductive isolation

    PubMed Central

    Bacquet, P. M. B.; Brattström, O.; Wang, H.-L.; Allen, C. E.; Löfstedt, C.; Brakefield, P. M.; Nieberding, C. M.

    2015-01-01

    Selection can facilitate diversification by inducing character displacement in mate choice traits that reduce the probability of maladaptive mating between lineages. Although reproductive character displacement (RCD) has been demonstrated in two-taxa case studies, the frequency of this process in nature is still debated. Moreover, studies have focused primarily on visual and acoustic traits, despite the fact that chemical communication is probably the most common means of species recognition. Here, we showed in a large, mostly sympatric, butterfly genus, a strong pattern of recurrent RCD for predicted male sex pheromone composition, but not for visual mate choice traits. Our results suggest that RCD is not anecdotal, and that selection for divergence in male sex pheromone composition contributed to reproductive isolation within the Bicyclus genus. We propose that selection may target olfactory mate choice traits as a more common sensory modality to ensure reproductive isolation among diverging lineages than previously envisaged. PMID:25740889

  6. Agency-Based Male Sex Work: A Descriptive Focus on Physical, Personal, and Social Space

    PubMed Central

    Smith, Michael D.; Grov, Christian; Seal, David W.

    2009-01-01

    Thirty male sex workers (MSWs) from a single agency participated in a qualitative interview about social and occupational aspects of their lives. MSWs established physical (defined areas where clients were not invited) and psychological (limitations of relationship with clients, other escorts, and the agency manager) boundaries to construct personal and professional space regarding sex work. Physical and psychological boundaries often were blended (e.g., bringing friends/family to the agency, utilizing the agency as a “drop-in community center”). The agency further mitigated negative aspects of sex work by providing job training, social support, stigma management, and dual-use space. Actors co-created a context wherein business could be conducted while meeting MSWs' psychosocial needs. PMID:19779572

  7. Influence of sex and age on PCBs accumulation in the commercial fish Chelon labrosus

    NASA Astrophysics Data System (ADS)

    Baptista, Joana; Pato, Pedro; Tavares, Sílvia; Duarte, Armando C.; Pardal, Miguel A.

    2013-05-01

    Thicklip grey mullet, Chelon labrosus, is an important commercial fish species and has been studied worldwide. However, no recent studies have been made regarding polychlorinated biphenyls (PCBs) in wild C. labrosus. Due to that, the concentration of 13 PCBs congeners was measured in muscles and livers, of males and females, of C. labrosus of different ages, allowing the estimation of PCB bioaccumulation throughout the species lifespan, in the Mondego estuary, a southern European temperate estuary. Male muscle sample concentrations ranged from 32 to 96 ng g- 1 (lipid wt.) and in females from 32 to 62 ng g- 1 (lipid wt.). In male liver sample concentrations ranged from 106 to 158 ng g- 1 (lipid wt.), while female concentrations ranged from 88 to 129 ng g- 1 (lipid wt.). The most abundant congeners presenting higher percentages in all samples were CB 138, 153 and 180. No significant differences were found between the concentrations in both sexes, but muscle and liver PCB concentrations in males tended to increase with age whereas in females concentrations remained stable throughout the species lifespan. Significant differences were found between concentrations in muscle and liver.

  8. Coming of Age in the Kisspeptin Era: Sex differences, Development, and Puberty

    PubMed Central

    Kauffman, Alexander S.

    2010-01-01

    The status of the neuroendocrine reproductive axis differs dramatically between early development, puberty, and various stages of adulthood, and also differs in several critical ways between the sexes, including its earlier pubertal activation in females than males and the presence of neural circuitry that generates preovulatory hormone surges in females but not males. The reproductive axis is controlled by various hormonal and neural pathways that converge upon forebrain gonadotropin-releasing hormone (GnRH) neurons, and many of the critical age and sex differences in the reproductive axis likely reflect differences in the “upstream” circuits and factors that regulate the GnRH system. Recently, the neural kisspeptin system has been implicated as an important regulator of GnRH neurons. Here I discuss the evidence supporting a critical role of kisspeptin signaling at different stages of life, including early postnatal and pubertal development, as well as in adulthood, focusing primarily on information gleaned from mammalian studies. I also evaluate key aspects of sexual differentiation and development of the brain as it relates to the Kiss1 system, with special emphasis on rodents. In addition to discussing recent advances in the field of kisspeptin biology, this paper will highlight a number of unanswered questions and future challenges for kisspeptin investigators, and will stress the importance of studying the kisspeptin system in both males and females, as well as in multiple species. PMID:20083160

  9. A meta-analysis of sex differences in cyber-bullying behavior: the moderating role of age.

    PubMed

    Barlett, Christopher; Coyne, Sarah M

    2014-01-01

    The current research used meta-analysis to determine whether (a) sex differences emerged in cyber-bullying frequency, (b) if age moderated any sex effect, and (c) if any additional moderators (e.g., publication year and status, country and continent of data collection) influenced the sex effect. Theoretically, if cyber-bullying is considered a form of traditional bullying and aggression, males are likely to cyber-bully more than females. Conversely, if cyber-bullying is considered relational/indirect aggression, females will be slightly more likely to cyber-bully than males. Results from 122 effect size estimates showed that males were slightly more likely to cyber-bully than females; however, age moderated the overall effect. Specifically, females were more likely to report cyber-bullying during early to mid-adolescence than males, while males showed higher levels of cyber-bullying during later adolescence than females. Publication status and year and continent and country of data collection also moderated the overall effect. PMID:25098968

  10. Female-to-male sex reversal in mice caused by transgenic overexpression of Dmrt1.

    PubMed

    Zhao, Liang; Svingen, Terje; Ng, Ee Ting; Koopman, Peter

    2015-03-15

    Genes related to Dmrt1, which encodes a DNA-binding DM domain transcription factor, act as triggers for primary sex determination in a broad range of metazoan species. However, this role is fulfilled in mammals by Sry, a newly evolved gene on the Y chromosome, such that Dmrt1 has become dispensable for primary sex determination and instead maintains Sertoli cell phenotype in postnatal testes. Here, we report that enforced expression of Dmrt1 in XX mouse fetal gonads using a Wt1-BAC transgene system is sufficient to drive testicular differentiation and male secondary sex development. XX transgenic fetal gonads showed typical testicular size and vasculature. Key ovarian markers, including Wnt4 and Foxl2, were repressed. Sertoli cells expressing the hallmark testis-determining gene Sox9 were formed, although they did not assemble into normal testis cords. Other bipotential lineages differentiated into testicular cell types, including steroidogenic fetal Leydig cells and non-meiotic germ cells. As a consequence, male internal and external reproductive organs developed postnatally, with an absence of female reproductive tissues. These results reveal that Dmrt1 has retained its ability to act as the primary testis-determining trigger in mammals, even though this function is no longer normally required. Thus, Dmrt1 provides a common thread in the evolution of sex determination mechanisms in metazoans. PMID:25725066

  11. Relationship dynamics and sexual risk behaviour of male partners of female sex workers in Kampala, Uganda.

    PubMed

    Mbonye, Martin; Siu, Godfrey E; Kiwanuka, Thadeus; Seeley, Janet

    2016-07-01

    Regular male partners of female sex workers (FSWs) represent an important population to reach with HIV-prevention interventions. This paper discusses the relationship dynamics and HIV/sexually transmitted infection risk behaviour of men involved with self-identified FSWs in Kampala. Between 2011 and 2014 we conducted repeat in-depth interviews with 42 male partners of FSWs attending a clinic for women at high risk of HIV-infection in Kampala. Men publicly struggled with the stigma of dating women who are considered to be engaged in a shamed profession, but privately saw meaning in these relationships. In coping with the stigma, some described the work of their partners in terms that distanced them from sex work, while others struggled to have the control that "being a man" demanded since they could not monitor all movements of their partners. Dealing with HIV disclosure was hard and seeking support was difficult for some of the men, leading to missed opportunities and guilt. Despite challenges, relationships with sex workers offered men some benefits such as access to much needed care and treatment. A few men also admitted to being motivated by material and financial benefits from sex workers who they perceived as being rich and this was one factor that helped them sustain the relationships. These findings offer insights into the complex relationship dynamics within high risk sexual partnerships. However, the findings suggest that effective interventions that are couple centred can be established to promote better health. PMID:27399044

  12. Awareness of Human Papillomavirus Vaccine Among Adolescent African American Males Who Have Sex with Males: a Pilot Study.

    PubMed

    Onyeabor, Onyekachi S; Martin, Nicolle; Orish, Verner N; Sanyaolu, Adekunle O; Iriemenam, Nnaemeka C

    2015-09-01

    African American adolescent males who have sex with males (MSMs) have a high prevalence of sexually transmitted diseases (STDs) that has been directly linked to lack of access to primary care providers and reluctance to disclose their sexuality. The human papillomavirus (HPV) is the most common STD with more than 40 different serotypes and can lead to anal/genital warts as well as oral and genital cancers. The HPV vaccine if taken prior to an adolescent becoming sexually active serves a prophylactic function. The HPV vaccine is approved by the Food and Drug Administration (FDA) for girls and boys; however, HPV vaccination rates among adolescents within different minority and underserved communities have been disappointing even though these groups are disproportionately infected with the HPV virus and certain male-specific cancers. Little is known about the uptake of the vaccine among African American MSMs and thus the aim of this study. This qualitative study is based on the health belief model and assessed participants' level of awareness of HPV, the HPV vaccine, and HPV-related illnesses among 24 African American male adolescents between 16 and 18 years old who self identify as MSMs. As part of a larger study, two focus groups were conducted for African American MSMs. Participants failed to understand their potential risk for HPV given the higher rates of STD infection experienced by MSMs. They expressed very little knowledge of the HPV vaccine and are also not aware of the complications of HPV virus infection. However, they were very eager to know more about the virus and the vaccine. This study demonstrates the need for the development of health communication intervention and more research targeting African American MSMs and also the need for policy change towards making the HPV vaccine routine for males especially adolescents at no cost. PMID:26863459

  13. Aging differently: diet- and sex-dependent late-life mortality patterns in Drosophila melanogaster.

    PubMed

    Zajitschek, Felix; Jin, Tuo; Colchero, Fernando; Maklakov, Alexei A

    2014-06-01

    Diet effects on age-dependent mortality patterns are well documented in a large number of animal species, but studies that look at the effects of nutrient availability on late-life mortality plateaus are lacking. Here, we focus on the effect of dietary protein content (low, intermediate, and high) on mortality trajectories in late life in the fruit fly Drosophila melanogaster. According to the two theories that are mainly implicated in explaining the deceleration of mortality rate in late life (the heterogeneity/frailty theory and the Hamiltonian theory), we predict, in general, the occurrence of late-life mortality deceleration under most circumstances, independent of sex and dietary regime. However, the heterogeneity theory of late life is more flexible in allowing no mortality deceleration to occur under certain circumstances compared with the Hamiltonian theory. We applied a novel statistical approach based on Bayesian inference of age-specific mortality rates and found a deceleration of late-life mortality rates on all diets in males but only on the intermediate (standard) diet in females. The difference in mortality rate deceleration between males and females on extreme diets suggests that the existence of mortality plateaus in late life is sex and diet dependent and, therefore, not a universal characteristic of large enough cohorts. PMID:24170671

  14. A re-examination of cremains weight: sex and age variation in a Northern California sample.

    PubMed

    Van Deest, Traci L; Murad, Turhon A; Bartelink, Eric J

    2011-03-01

    The reduction of modern commercially cremated remains into a fine powder negates the use of traditional methods of skeletal analysis. The literature on the use of cremains weight for estimating aspects of the biologic profile is limited, often with conflicting results. This study re-evaluates the value of weight in the assessment of biologic parameters from modern cremated remains. A sample of adults was collected in northern California (n = 756), with a cremains weight averaging 2737.1 g. Males were significantly heavier than females (mean = 3233.2 g versus mean = 2238.3 g, respectively; p<0.001). Comparison of this sample with other previously reported samples from southern California, Florida, and Tennessee indicates a consistent sex difference, with the most similar mean values to the Tennessee study. Although cremains weight decreases with age as expected, the relationship is weak; thus, cremains weight cannot accurately predict age-at-death. While sex estimation shows considerable accuracy (86.3% for males and 80.9% for females), sectioning points may be population specific. PMID:21265835

  15. Age, actuarial risk, and long-term recidivism in a national sample of sex offenders.

    PubMed

    Nicholaichuk, Terry P; Olver, Mark E; Gu, Deqiang; Wong, Stephen C P

    2014-10-01

    Age at release has become an increasing focus of study with regard to evaluating risk in the sex offender population and has been repeatedly shown to be an important component of the risk assessment equation. This study constitutes an extension of a study of sex offender outcomes prepared for the Evaluation Branch, Correctional Service of Canada. The entire cohort of 2,401 male federally incarcerated sexual offenders who reached their warrant expiry date (WED) within 1997/1998, 1998/1999, and 1999/2000 fiscal years were reviewed for the study. Sexual and violent reconviction information was obtained from CPIC criminal records over an average of 12.0 years (SD = 1.7) follow-up. This study focused upon the cohort of sex offenders who were 50 years or older at time of release (N = 542). They were stratified according to risk using a brief actuarial scale (BARS) comprising six binary variables. For the most part, older offenders showed low base rates of sexual recidivism regardless of the risk band into which they fell. The exception was a small group of elderly offenders (n = 20) who fell into the highest risk band, and who showed high levels of sexual recidivism. The results of this combination of cross-sectional and longitudinal analyses of elderly sexual offenders may have important implications for offender management, particularly in light of the increasing numbers of offenders in Canada who fall into the over 50 age cohort. PMID:23818657

  16. Sex Ratio Meiotic Drive as a Plausible Evolutionary Mechanism for Hybrid Male Sterility

    PubMed Central

    Zhang, Linbin; Xiao, Hailian; Tao, Yun

    2015-01-01

    Biological diversity on Earth depends on the multiplication of species or speciation, which is the evolution of reproductive isolation such as hybrid sterility between two new species. An unsolved puzzle is the exact mechanism(s) that causes two genomes to diverge from their common ancestor so that some divergent genes no longer function properly in the hybrids. Here we report genetic analyses of divergent genes controlling male fertility and sex ratio in two very young fruitfly species, Drosophila albomicans and D. nasuta. A majority of the genetic divergence for both traits is mapped to the same regions by quantitative trait loci mappings. With introgressions, six major loci are found to contribute to both traits. This genetic colocalization implicates that genes for hybrid male sterility have evolved primarily for controlling sex ratio. We propose that genetic conflicts over sex ratio may operate as a perpetual dynamo for genome divergence. This particular evolutionary mechanism may largely contribute to the rapid evolution of hybrid male sterility and the disproportionate enrichment of its underlying genes on the X chromosome – two patterns widely observed across animals. PMID:25822261

  17. Sex- and age-specific differences in relaxin family peptide receptor expression within the hippocampus and amygdala in rats.

    PubMed

    Meadows, K L; Byrnes, E M

    2015-01-22

    Relaxin is an essential pregnancy-related hormone with broad peripheral effects mediated by activation of relaxin-like family peptide 1 receptors (RXFP1). More recent studies suggest an additional role for relaxin as a neuropeptide, with RXFP1 receptors expressed in numerous brain regions. Neurons in an area of the brainstem known as the nucleus incertus (NI) produce relaxin 3 (RLN3), the most recently identified neuropeptide in the relaxin family. RLN3 has been shown to activate both RXFP1 and relaxin-like family peptide receptor 3 (RXFP3) receptor subtypes. Studies suggest wide-ranging neuromodulatory effects of both RXFP1 and RXFP3 activation, although to date the majority of studies have been conducted in young males. In the current study, we examined potential sex- and age-related changes in RLN3 gene expression in the NI as well as RXFP1 and RXFP3 gene expression in the dorsal hippocampus (HI), ventral hippocampus (vHI) and amygdala (AMYG) using young adult (9-12weeks) and middle-aged (9-12months) male and female rats. In addition, regional changes in RXFP1 and RXFP3 protein expression were examined in the CA1, CA2/CA3 and dentate gyrus (DG) as well as within basolateral (BLA), central (CeA), and medial (MeA) amygdaloid nuclei. In the NI, RLN3 showed an age-related decrease in males. In the HI, only the RXFP3 receptor showed an age-related change in gene expression, however, both receptor subtypes showed age-related changes in protein expression that were region specific. Additionally, while gene and protein expression of both receptors increased with age in AMYG, these effects were both region- and sex-specific. Finally, overall males displayed a greater number of cells that express the RXFP3 protein in all of the amygdaloid nuclei examined. Cognitive and emotional processes regulated by activity within the HI and AMYG are modulated by both sex and age. The vast majority of studies exploring the influence of sex on age-related changes in the HI and AMYG have

  18. Sex ratio of congenital abnormalities in the function of maternal age: a population-based study.

    PubMed

    Csermely, Gyula; Urbán, Robert; Czeizel, Andrew E; Veszprémi, Béla

    2015-05-01

    Maternal age effect is well-known in the origin of numerical chromosomal aberrations and some isolated congenital abnormalities (CAs). The sex ratio (SR), i.e. number of males divided by the number of males and females together, of most CAs deviates from the SR of newborn population (0.51). The objective of this analysis was to evaluate the possible association of maternal age with the SR of isolated CAs in a population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. First, SR of 24 CA entities/groups was estimated in 21,494 patients with isolated CA. In the next step SR of different maternal age groups was compared to the mean SR of the given CA-groups. The SR of four CA-groups showed some deviation in certain maternal age groups. Cases with anencephaly had female excess in young mothers (<25 years). Cases with skull's CAs particularly craniosynostosis had a male excess in cases born to women over 30 years. Two other CA groups (cleft lip ± palate and valvar pulmonic stenosis within the group of right-sided obstructive defect of heart) had significant deviation in SR of certain maternal age groups from the mean SR, but these deviations were not harmonized with joining age groups and thus were considered as a chance effect due to multiple testing. In conclusion, our study did not suggest that in general SR of isolated CAs might be modified by certain maternal age groups with some exception such as anencephaly and craniosynostosis. PMID:25354028

  19. "Come on Baby. You Know I Love You": African American Women's Experiences of Communication with Male Partners and Disclosure in the Context of Unwanted Sex.

    PubMed

    Gutzmer, Kyle; Ludwig-Barron, Natasha T; Wyatt, Gail E; Hamilton, Alison B; Stockman, Jamila K

    2016-05-01

    We examined African American women's experiences of communication with their male intimate partners a couple of hours before and after an incident of unwanted sex. We also examined women's experiences of disclosure following an incident of unwanted sex. Semi-structured qualitative interviews were conducted with a community-based sample of sexually active African American women (n = 19) reporting at least one incident of sexual coercion (i.e., being pressured into unwanted sex without consent) by an intimate male partner since the age of 18. Our analysis was guided by "the sexual division of power" from Connell's (1987) theory of gender and power. Data were analyzed inductively by examining the interviews for common themes in the following domains: communication before the unwanted sex, communication after the unwanted sex, and disclosure to others. Men pressured partners for unwanted sex through verbal and non-verbal tactics, ranging from pestering and blunt requests for sex to verbal bullying and violence. Many women responded by clearly saying no. However, many women also described eventually ceasing to resist their partners and engaging in unwanted sex. After the unwanted sex, men actively and passively avoided discussing the incident. Although many women discussed the unwanted sex with family and friends, less women disclosed to trained professionals. In some cases, women did not discuss the incident with anyone at all. These findings indicate that, when addressing sexual violence against women, there is a need to target men as well as the norms of masculinity that underpin physical and sexual violence against women. PMID:26892099

  20. Persuasion Tactics Used by College Age Females on College Age Males.

    ERIC Educational Resources Information Center

    Hanson, Erika J.; Pollard, Gloria D.; Williams, Christina M.

    This paper researched persuasive tactics used by college age females on college age males. Previous evidence indicates that nonverbal persuasion is more effective than verbal persuasion. The topics explored in previous research on persuasion consisted of physical attractiveness, indirect knowledge of influence, tactics used by children and college…

  1. Persistence of an extreme male-biased adult sex ratio in a natural population of polyandrous bird.

    PubMed

    Kosztolányi, A; Barta, Z; Küpper, C; Székely, T

    2011-08-01

    In a number of insects, fishes and birds, the conventional sex roles are reversed: males are the main care provider, whereas females focus on matings. The reversal of typical sex roles is an evolutionary puzzle, because it challenges the foundations of sex roles, sexual selection and parental investment theory. Recent theoretical models predict that biased parental care may be a response to biased adult sex ratios (ASRs). However, estimating ASR is challenging in natural populations, because males and females often have different detectabilities. Here, we use demographic modelling with field data from 2101 individuals, including 579 molecularly sexed offspring, to provide evidence that ASR is strongly male biased in a polyandrous bird with male-biased care. The model predicts 6.1 times more adult males than females (ASR=0.860, proportion of males) in the Kentish plover Charadrius alexandrinus. The extreme male bias is consistent between years and concordant with experimental results showing strongly biased mating opportunity towards females. Based on these results, we conjecture that parental sex-role reversal may occur in populations that exhibit extreme male-biased ASR. PMID:21749544

  2. Age- and sex-related changes in vibrotactile sensitivity of hand and face in neurotypical adults.

    PubMed

    Venkatesan, Lalit; Barlow, Steven M; Kieweg, Douglas

    2015-01-01

    Sensory perception decreases with age, and is altered as a function of sex. Very little is known about the age- and sex-related changes in vibrotactile detection thresholds (VDTs) of the face relative to the glabrous hand. This study utilized a single-interval up/down (SIUD) adaptive procedure to estimate the VDT for mechanical stimuli presented at 5, 10, 50, 150, 250, and 300 Hz at two sites on the face, including the right non-glabrous surface of the oral angle and the right lower lip vermilion; and on the hand on the glabrous surface of the distal phalanx of the right dominant index finger. Eighteen right-handed healthy younger adults and 18 right-handed healthy older adults participated in this study. VDTs were significantly different between the three stimulus sites (p < 0.0001), and dependent on stimulus frequency (p < 0.0001) and the sex of the participants (p < 0.005). VDTs were significantly higher for older adults when compared to younger adults for the finger stimulation condition (p < 0.05). There were significant differences (p < 0.05) in cheek and lower lip VDTs between male and female subjects. Difference in the VDTs between the three stimulation sites is presumed to reflect the unique typing and distribution of mechanoreceptors in the face and hand. Age-related differences in finger skin sensitivity are likely due to changes in the physical structure of skin, changes in the number and morphology of the mechanoreceptors, differences in the functional use of the hand, and its central representation. Sex-related differences in the VDTs may be due to the differences in tissue conformation and thickness, mechanoreceptor densities, skin hydration, or temperature characteristics. PMID:25248543

  3. Male Prison Inmates With Gender Dysphoria: When Is Sex Reassignment Surgery Appropriate?

    PubMed

    Osborne, Cynthia S; Lawrence, Anne A

    2016-10-01

    Gender dysphoria (GD), a feeling of persistent discomfort with one's biologic sex or assigned gender, is estimated to be more prevalent in male prison inmates than in nonincarcerated males; there may be 3000-4000 male inmates with GD in prisons in the United States. An increasing number of U.S. prison systems now offer gender dysphoric inmates diagnostic evaluation, psychotherapy, cross-sex hormone therapy, and opportunities, albeit limited, to enact their preferred gender role. Sex reassignment surgery (SRS), however, has not been offered to inmates except in response to litigation. In the first case of its kind, the California Department of Corrections and Rehabilitation recently agreed to provide SRS to an inmate and developed policy guidelines for its future provision. In other recent cases, U.S. courts have ruled that male inmates with GD are entitled to SRS when it is medically necessary. Although these decisions may facilitate the provision of SRS to inmates in the future, many U.S. prison systems will probably remain reluctant to offer SRS unless legally compelled to do so. In this review, we address the medical necessity of SRS for male inmates with GD. We also discuss eligibility criteria and the practical considerations involved in providing SRS to inmates. We conclude by offering recommendations for physicians, mental health professionals, and prison administrators, designed to facilitate provision of SRS to inmates with GD in a manner that provides humane treatment, maximizes the likelihood of successful outcomes, minimizes risk of regret, and generates data that can help inform future decisions. PMID:26979819

  4. Hyoid bone fusion and bone density across the lifespan: prediction of age and sex.

    PubMed

    Fisher, Ellie; Austin, Diane; Werner, Helen M; Chuang, Ying Ji; Bersu, Edward; Vorperian, Houri K

    2016-06-01

    The hyoid bone supports the important functions of swallowing and speech. At birth, the hyoid bone consists of a central body and pairs of right and left lesser and greater cornua. Fusion of the greater cornua with the body normally occurs in adulthood, but may not occur at all in some individuals. The aim of this study was to quantify hyoid bone fusion across the lifespan, as well as assess developmental changes in hyoid bone density. Using a computed tomography imaging studies database, 136 hyoid bones (66 male, 70 female, ages 1-to-94) were examined. Fusion was ranked on each side and hyoid bones were classified into one of four fusion categories based on their bilateral ranks: bilateral distant non-fusion, bilateral non-fusion, partial or unilateral fusion, and bilateral fusion. Three-dimensional hyoid bone models were created and used to calculate bone density in Hounsfield units. Results showed a wide range of variability in the timing and degree of hyoid bone fusion, with a trend for bilateral non-fusion to decrease after age 20. Hyoid bone density was significantly lower in adult female scans than adult male scans and decreased with age in adulthood. In sex and age estimation models, bone density was a significant predictor of sex. Both fusion category and bone density were significant predictors of age group for adult females. This study provides a developmental baseline for understanding hyoid bone fusion and bone density in typically developing individuals. Findings have implications for the disciplines of forensics, anatomy, speech pathology, and anthropology. PMID:27114259

  5. Sex difference in pathology of the ageing gut mediates the greater response of female lifespan to dietary restriction

    PubMed Central

    Regan, Jennifer C; Khericha, Mobina; Dobson, Adam J; Bolukbasi, Ekin; Rattanavirotkul, Nattaphong; Partridge, Linda

    2016-01-01

    Women live on average longer than men but have greater levels of late-life morbidity. We have uncovered a substantial sex difference in the pathology of the aging gut in Drosophila. The intestinal epithelium of the aging female undergoes major deterioration, driven by intestinal stem cell (ISC) division, while lower ISC activity in males associates with delay or absence of pathology, and better barrier function, even at old ages. Males succumb to intestinal challenges to which females are resistant, associated with fewer proliferating ISCs, suggesting a trade-off between highly active repair mechanisms and late-life pathology in females. Dietary restriction reduces gut pathology in aging females, and extends female lifespan more than male. By genetic sex reversal of a specific gut region, we induced female-like aging pathologies in males, associated with decreased lifespan, but also with a greater increase in longevity in response to dietary restriction. DOI: http://dx.doi.org/10.7554/eLife.10956.001 PMID:26878754

  6. Perceptions about HIV and condoms and consistent condom use among male clients of commercial sex workers in the Philippines.

    PubMed

    Regan, Rotrease; Morisky, Donald E

    2013-04-01

    Because consistent condom use is an effective strategy in the prevention of sexually transmitted infections and HIV transmission, it is important to examine social cognitive influences of consistent condom use not only among female sex workers (FSWs) but also among their male clients, for whom less is known. Because little is known about how HIV knowledge and condom attitudes affect condom use among male clients of FSWs in the Philippines, the main objective was to determine what characteristics (age, education, HIV knowledge, marital status) as well as attributes taken from protection motivation theory (perceived vulnerability, perceived severity, response efficacy) are significantly associated with consistent condom use among male clients of FSWs. Logistic regression analyses showed that the odds of using condoms consistently with an FSW are 13% higher for those with more years of education (adjusted odds ratio [AOR] = 1.13; 95% confidence interval [CI] = 1.03, 1.23), higher versus lower perception of severity of HIV/AIDS (AOR = 1.97; 95% CI = 1.04, 3.73), and had a higher score for response efficacy of condoms (AOR = 1.14; 95% CI = 1.03, 1.27). Future HIV/AIDS prevention interventions that address condom use among male clients should promote educational attainment and focus on awareness of the enduring negative health consequences of acquiring HIV/AIDS, as well as cultivate positive attitudes toward the efficacy of condom use, using creative social marketing strategies. PMID:22773598

  7. Mating-induced differential coding of plant odour and sex pheromone in a male moth.

    PubMed

    Barrozo, Romina B; Jarriault, David; Deisig, Nina; Gemeno, Cesar; Monsempes, Christelle; Lucas, Philippe; Gadenne, Christophe; Anton, Sylvia

    2011-05-01

    Innate behaviours in animals can be influenced by several factors, such as the environment, experience, or physiological status. This behavioural plasticity originates from changes in the underlying neuronal substrate. A well-described form of plasticity is induced by mating. In both vertebrates and invertebrates, males experience a post-ejaculatory refractory period, during which they avoid new females. In the male moth Agrotis ipsilon, mating induces a transient inhibition of responses to the female-produced sex pheromone. To understand the neural bases of this inhibition and its possible odour specificity, we carried out a detailed analysis of the response characteristics of the different neuron types from the periphery to the central level. We examined the response patterns of pheromone-sensitive and plant volatile-sensitive neurons in virgin and mated male moths. By using intracellular recordings, we showed that mating changes the response characteristics of pheromone-sensitive antennal lobe (AL) neurons, and thus decreases their sensitivity to sex pheromone. Individual olfactory receptor neuron (ORN) recordings and calcium imaging experiments indicated that pheromone sensory input remains constant. On the other hand, calcium responses to non-pheromonal odours (plant volatiles) increased after mating, as reflected by increased firing frequencies of plant-sensitive AL neurons, although ORN responses to heptanal remained unchanged. We suggest that differential processing of pheromone and plant odours allows mated males to transiently block their central pheromone detection system, and increase non-pheromonal odour detection in order to efficiently locate food sources. PMID:21488987

  8. Genetic manipulation of sex ratio for the large-scale breeding of YY super-male and XY all-male yellow catfish (Pelteobagrus fulvidraco (Richardson)).

    PubMed

    Liu, Hanqin; Guan, Bo; Xu, Jiang; Hou, Changchun; Tian, Hua; Chen, Hongxi

    2013-06-01

    Yellow catfish has become one of the most important freshwater aquaculture species in China. The mono-sex male yellow catfish has important application value in aquaculture because the male grows generally faster than the sibling females under the same conditions. This study has screened YY super-male and YY physiological female yellow catfish by sex reversal, gynogenesis, and progeny testing, which can help to achieve the large-scale production of YY super-male and XY all-male. From 2008 to 2010, about 123,000 YY super-male were produced, and about 81 million XY all-male fry were produced with 100% male rate by random sampling. Therefore, these results indicate that YY super-male and YY physiological female yellow catfish can be viable and fertile. We conclude that the mono-sex breeding technique by YY super-male yellow catfish is stable and reliable, which has great potential for application in yellow catfish aquaculture. PMID:23053056

  9. Frequency distribution analysis of activation times and regional fibrosis in murine Scn5a+/− hearts: The effects of ageing and sex

    PubMed Central

    Jeevaratnam, Kamalan; Rewbury, Rebecca; Zhang, Yanmin; Guzadhur, Laila; Grace, Andrew A.; Lei, Ming; Huang, Christopher L.-H.

    2012-01-01

    Both Brugada Syndrome (BrS) and progressive cardiac conduction defect (PCCD) are associated respectively with diffuse and discrete alterations in conduction pathways affected by ageing and sex. This study assessed for contributions of such processes to the mechanism of conduction changes in Scn5a+/− and WT hearts stratified by age (3 and 12 months) and sex. In vivo electrocardiographic chest-lead assessment demonstrated greater incidences of bundle branch block in all Scn5a+/− mice compared to WT. Frequency analysis of right ventricular (RV) epicardial activation obtained from a 64-channel multi-electrode array demonstrated greater prominence of late conducting components in Scn5a+/− compared to WT male, and in male compared to female Scn5a+/− following stratification by genotype and sex. Similar differences were observed between old male Scn5a+/− and young male Scn5a+/−, old female Scn5a+/−, and old male WT, following stratification by genotype, age and sex. These findings directly correlated with histomorphometric assessment of regional fibrosis in both septa and free walls preferentially involving the RV. We demonstrate complex alterations in conduction distributions suggesting a conversion of normal to slow-conducting tissue, modulated by ageing and sex, coupled with fibrosis in Scn5a+/− hearts. These features suggest an overlap between pathophysiological processes related to BrS and PCCD in Scn5a+/− hearts. PMID:22968175

  10. Age and sex-specific mortality of wild and captive populations of a monogamous pair-bonded primate (Aotus azarae).

    PubMed

    Larson, Sam M; Colchero, Fernando; Jones, Owen R; Williams, Lawrence; Fernandez-Duque, Eduardo

    2016-03-01

    In polygynous primates, a greater reproductive variance in males have been linked to their reduced life expectancy relative to females. The mortality patterns of monogamous pair-bonded primates, however, are less clear. We analyzed the sex differences in mortality within wild (NMales  = 70, NFemales  = 73) and captive (NMales  = 25, NFemales  = 29) populations of Azara's owl monkeys (Aotus azarae), a socially and genetically monogamous primate exhibiting biparental care. We used Bayesian Survival Trajectory Analysis (BaSTA) to test age-dependent models of mortality. The wild and captive populations were best fit by the logistic and Gompertz models, respectively, implying greater heterogeneity in the wild environment likely due to harsher conditions. We found that age patterns of mortality were similar between the sexes in both populations. We calculated life expectancy and disparity, the latter a measure of the steepness of senescence, for both sexes in each population. Males and females had similar life expectancies in both populations; the wild population overall having a shorter life expectancy than the captive one. Furthermore, captive females had a reduced life disparity relative to captive males and to both sexes in the wild. We interpret this pattern in light of the hazards associated with reproduction. In captivity, where reproduction is intensely managed, the risks associated with gestation and birth are tempered so that there is a reduction in the likelihood of captive females dying prematurely, decreasing their overall life disparity. PMID:25866126

  11. Androgens in a female primate: Relationships with reproductive status, age, dominance rank, fetal sex and secondary sexual color.

    PubMed

    Setchell, Joanna M; Smith, Tessa E; Knapp, Leslie A

    2015-08-01

    A comprehensive understanding of the role of androgens in reproduction, behavior and morphology requires the examination of female, as well as male, hormone profiles. However, we know far less about the biological significance of androgens in females than in males. We investigated the relationships between fecal androgen (immunoreactive testosterone) levels and reproductive status, age, dominance rank, fetal sex and a secondary sexual trait (facial color) in semi-free-ranging female mandrills (Mandrillus sphinx), using samples collected from 19 reproductively mature females over 13months. Fecal androgens varied with reproductive status, being highest during gestation. Fecal androgens began to increase at 3months of gestation, and peaked at 5months. This pattern is more similar to that found in a platyrrhine than in other cercopithecine species, suggesting that such patterns are not necessarily phylogenetically constrained. Fecal androgens did not vary systematically with rank, in contrast to the relationship we have reported for male mandrills, and in line with sex differences in how rank is acquired and maintained. Offspring sex was unrelated to fecal androgens, either prior to conception or during gestation, contrasting with studies of other primate species. Mean facial color was positively related to mean fecal androgens across females, reflecting the same relationship in male mandrills. However, the relationship between color and androgens was negative within females. Future studies of the relationship between female androgens and social behavior, reproduction and secondary sexual traits will help to elucidate the factors underlying the similarities and differences found between the sexes and among studies. PMID:25936819

  12. The Male-Female Health-Survival Paradox and Sex Differences in Cohort Life Expectancy in Utah, Denmark and Sweden 1850-1910

    PubMed Central

    Lindahl-Jacobsen, Rune; Hanson, Heidi A.; Oksuzyan, Anna; Mineau, Geraldine P.; Christensen, Kaare; Smith, Ken R.

    2013-01-01

    Purpose In Utah, prevalence of unhealthy male risk behaviours are lower than in most other male populations while women experience higher mortality risk due to higher fertility rates. Therefore, we hypothesize that the Utah sex differential in mortality would be small and less than in Sweden and Denmark. Methods Life tables from Utah, Denmark and Sweden, were used to calculate cohort life expectancies for men and women born 1850-1910. Results The sex difference in cohort life expectancy was similar or larger in Utah when compared to Denmark and Sweden. The change over time in the sex differences in cohort life expectancy was approximately two years smaller for active Mormons in Utah than for other groups suggesting lifestyle as an important component for the overall change seen in cohort life expectancy. Sex differences in cohort life expectancy at age 50 were similar for individuals actively affiliated with the Church of Jesus Christ of Latter-day Saints and for Denmark and Sweden. Conclusions The hypothesis that a smaller sex difference in cohort life expectancies in Utah would be detected in relation to Denmark and Sweden was not supported. In Utah the male-female differences in life expectancy remain substantial pointing towards biological mechanisms, or other unmeasured risk factors. PMID:23453386

  13. The value of outside support for male and female politicians involved in a political sex scandal.

    PubMed

    Stewart, Dennis D; Rose, Roger P; Rosales, Felixia M; Rudney, Philip D; Lehner, Tasha A; Miltich, Gemma; Snyder, Cassie; Sadecki, Brianna

    2013-01-01

    This research examined how third party statements impact the evaluation of male and female politicians caught in a scandal (i.e., extramarital affair). Governor's sex was crossed with three types of support statements: third party supportive (TPS), third party non-supportive (TPNS), and governor self-supportive (GSS). In Experiment 1, a female politician was evaluated more positively than a male politician. The TPS and the GSS conditions were both evaluated more positively than the TPNS condition. Experiment 2's design was similar to Experiment l's, except it involved multiple affairs. In Experiment 2, participants used the third party's statements as an information source and thus reduced their use of gender stereotypes in the TPS and TPNS conditions compared to the GSS condition. We also found that male respondents gave more negative evaluations of the female governor than female respondents. Implications for the gender stereotype and social influence literatures are discussed. PMID:23724705

  14. Age, sex and APOE ε4 effects on memory, brain structure and β-amyloid across the adult lifespan

    PubMed Central

    Jack, Clifford R.; Wiste, Heather J.; Weigand, Stephen D.; Knopman, David S.; Vemuri, Prashanthi; Mielke, Michelle M.; Lowe, Val; Senjem, Matthew L.; Gunter, Jeffrey L.; Machulda, Mary M.; Gregg, Brian E.; Pankratz, Vernon S.; Rocca, Walter A.; Petersen, Ronald C.

    2015-01-01

    Importance Typical cognitive aging may be defined as age associated changes in cognitive performance in individuals who remain free of dementia. Ideally the full adult age spectrum should be included to assess brain imaging findings associated with typical aging. Objective To compare age, sex and Apolipoprotein E (APOE ε4) effects on memory, brain structure (adjusted hippocampal volume, HVa) and amyloid PET in cognitively normal individuals aged 30 to 95 years old. Design, Setting, and Participants Cross sectional observational study (Marc 2006 to October 2014) at an academic medical center. We studied 1246 cognitively normal subjects; 1209 participants aged 50–95 years old enrolled in a population-based study of cognitive aging and 37 self-selected volunteers aged 30–49. Main Outcomes and Measures Memory, HVa, and amyloid PET Results Overall, memory worsened from age 30 years through the 90s. HVa worsened gradually from 30 years to the mid-60s and more steeply beyond that age. The median amyloid PET was low until age 70 years and increased thereafter. Memory was worse in men than women overall (p<0.001) and more specifically beyond age 40 years. HVa was lower in men than women overall (p<0.001) and more specifically beyond age 60 years. There was no sex difference in amyloid PET at any age. Within each sex, memory performance and HVa were not different by APOE ε4 at any age. From age 70 years onward APOE ε4 carriers had significantly greater median amyloid PET load than noncarriers. However the ages at which 10% of the population were amyloid PET positive were 57 years for APOE ε4 carriers and 64 years for non-carriers. Conclusions and Relevance Male sex is associated with worse memory and HVa among cognitively normal individuals while APOE ε4 is not. In contrast, APOE ε4 is associated with greater amyloid PET values (from age 70 years onward) while sex is not. Worsening memory and HVa occur at earlier ages than abnormal amyloid PET. Therefore

  15. A spatiotemporal analysis of aggregate labour force behaviour by sex and age across the European Union

    NASA Astrophysics Data System (ADS)

    Elhorst, J. Paul

    2008-06-01

    This study investigates the causes of variation in age-specific male and female labour force participation rates using annual data from 154 regions across ten European Union member states for the period 1983-1997. Regional participation rates appear to be strongly correlated in time, weakly correlated in space and to parallel their national counterparts. An econometric model is designed consistent with these empirical findings. To control for potential endogeneity of the explanatory variables, we use an instrumental variables estimation scheme based on a matrix exponential spatial specification of the error terms. Many empirical studies of aggregate labour force behaviour have ignored population distribution effects, relying instead on the representative-agent paradigm. In order for representative-agent models to accurately describe aggregate behaviour, all marginal reactions of individuals to changes in aggregate variables must be identical. It turns out that this condition cannot apply to individuals across different sex/age groups.

  16. The role of male age, sperm age and mating history on fecundity and fertilization success in the hide beetle.

    PubMed Central

    Jones, Therésa M.; Elgar, Mark A.

    2004-01-01

    Models of age-related mate choice predict female preference for older males as they have proven survival ability. However, these models rarely address differences in sperm age and male mating history when evaluating the potential benefits to females from older partners. We used a novel experimental design to assess simultaneously the relative importance of these three parameters in the hide beetle, Dermestes maculatus. In a two-part experiment we first explored age-related male mating success and subsequently examined the consequences of male age, sperm age and male mating history on female fecundity and fertilization success. In a competitive mating environment, intermediate-age males gained significantly higher mating success than younger or older males. To test the consequences for females of aged-related male mating success, a second set of females were mated to males varying in age (young, intermediate-age and old), in numbers of matings and in timing of the most recent mating. We found that male age had a significant impact on female fecundity and fertilization success. Females mated to intermediate-age males laid more eggs and attained consistently higher levels of fertilization success than females with young and old mates. A male's previous mating history determined his current reproductive effort; virgin males spent longer in copula than males with prior mating opportunities. However, differences in copulation duration did not translate into increased fecundity or fertilization success. There was also little evidence to suggest that fertilization success was dependent on the age of a male's sperm. The experiment highlights the potential direct benefits accrued by females through mating with particular aged males. Such benefits are largely ignored by traditional viability models of age-related male mating success. PMID:15306356

  17. Male-biased sex ratios of fish embryos near a pulp mill: temporary recovery after a short-term shutdown.

    PubMed Central

    Larsson, D G Joakim; Förlin, Lars

    2002-01-01

    In a previous study we showed that broods from the viviparous eelpout Zoarces viviparus were significantly male biased in 1998 in the vicinity of a large kraft pulp mill on the Swedish Baltic coast. One suggested hypothesis was that masculinizing compounds in the effluent were affecting gonadal differentiation of the embryos, resulting in skewed sex ratios. In this article, we present further evidence for a causal relationship between the exposure to the effluent and the male-biased sex ratios. Analyses of historical samples showed that the eelpout produced male-biased broods close to the mill in 1997 in addition to 1998. During 1999, the mill was shut down for 17 days, coinciding with the period when the gonads of the eelpout embryos differentiate. Subsequently, in the fall of 1999, the sex ratios were no longer male biased; however, the following year (2000), a significant male bias reappeared. Investigations at 13 sites for up to 4 years showed a relatively stable sex ratio around 50/50, with the exceptions by the mill and with few observations of deviating ratios at other sites. Several reports document endocrine disturbances in fish near pulp and paper mills, including the expression of male secondary sex characters in female fish. The repeatedly identified male bias at the investigated mill, the normalization after mill shutdown, and the reappearance the following year indicate that pulp mill effluents also can affect sex ratios of nearby fish. PMID:12153752

  18. Age- and Sex-Related Characteristics of Tonic Gaba Currents in the Rat Substantia Nigra Pars Reticulata

    PubMed Central

    Hasson, H.; Bojar, M.; Moshé, S. L.; Galanopoulou, A. S.

    2015-01-01

    Previous studies have shown that the pharmacologic effects of GABAergic drugs and the postsynaptic phasic GABAAergic inhibitory responses in the anterior part of the rat substantia nigra pars reticulata (SNRA) are age- and sex-specific. Here, we investigate whether there are age- and sex-related differences in the expression of the δ GABAA receptor (GABAAR) subunit and GABAAR mediated tonic currents. We have used δ-specific immunochemistry and whole cell patch clamp to study GABAAR mediated tonic currents in the SNRA of male and female postnatal day (PN) PN5-9, PN11-16, and PN25-32 rats. We observed age-related decline, but no sex-specific changes, in bicuculline (BIM) sensitive GABAAR tonic current density, which correlated with the decline in δ subunit in the SNRA between PN15 and 30. Furthermore, we show that the GABAAR tonic currents can be modified by muscimol (GABAAR agonist; partial GABACR agonist), THIP (4,5,6,7-tetrahydroisoxazolo (5,4-c)pyridin-3-ol: α4β3δ GABAARs agonist and GABACR antagonist), and zolpidem (α1-subunit selective GABAAR agonist) in age-and sex-dependent manner specific for each drug. We propose that the emergence of the GABAAR-sensitive anticonvulsant effects of the rat SNRA during development may depend upon the developmental decline in tonic GABAergic inhibition of the activity of rat SNRA neurons, although other sex-specific factors are also involved. PMID:25645446

  19. Age- and sex-related characteristics of tonic GABA currents in the rat substantia nigra pars reticulata.

    PubMed

    Chudomel, O; Hasson, H; Bojar, M; Moshé, S L; Galanopoulou, A S

    2015-04-01

    Previous studies have shown that the pharmacologic effects of GABAergic drugs and the postsynaptic phasic GABAAergic inhibitory responses in the anterior part of the rat substantia nigra pars reticulata (SNRA) are age- and sex-specific. Here, we investigate whether there are age- and sex-related differences in the expression of the δ GABAA receptor (GABAAR) subunit and GABAAR mediated tonic currents. We have used δ-specific immunochemistry and whole cell patch clamp to study GABAAR mediated tonic currents in the SNRA of male and female postnatal day (PN) PN5-9, PN11-16, and PN25-32 rats. We observed age-related decline, but no sex-specific changes, in bicuculline (BIM) sensitive GABAAR tonic current density, which correlated with the decline in δ subunit in the SNRA between PN15 and 30. Furthermore, we show that the GABAAR tonic currents can be modified by muscimol (GABAAR agonist; partial GABACR agonist), THIP (4,5,6,7-tetrahydroisoxazolo (5,4-c)pyridin-3-ol: α4β3δ GABAARs agonist and GABACR antagonist), and zolpidem (α1-subunit selective GABAAR agonist) in age- and sex-dependent manner specific for each drug. We propose that the emergence of the GABAAR-sensitive anticonvulsant effects of the rat SNRA during development may depend upon the developmental decline in tonic GABAergic inhibition of the activity of rat SNRA neurons, although other sex-specific factors are also involved. PMID:25645446

  20. Regional variation of intracortical porosity in the midshaft of the human femur: age and sex differences

    PubMed Central

    Thomas, C David L; Feik, Sophie A; Clement, John G

    2005-01-01

    This study investigated age and sex differences in patterns of porosity distribution in the midshaft of the human femur. Cross-sections were obtained from 168 individuals from a modern Australian population. The sample comprised 73 females and 95 males, aged between 20 and 97 years. Microradiographs were made of 100-µm sections and pore and bone areas were determined using image processing software. Initially the sample was divided by age: young (20–44 years), middle (45–64 years) and old (65+ years), but it was found that analysis on the basis of the ratio of medullary area to total subperiosteal area gave clearer results. The cortex was divided into three rings radially and into octants circumferentially and the porosity of each segment was calculated. Results showed that a pattern with raised porosity in the posterior and anterolateral regions, and with greater porosity in the inner parts of the cortex, becomes more pronounced with age. In males this pattern develops steadily; in females there are much greater differences between the middle and older groups than earlier in life. The patterns observed are consistent with progressive bone loss occurring along a neutral axis of the cortex where bending stress is lowest and the mechanical advantage of the bone is least. PMID:15730477

  1. How to make a sexy snake: estrogen activation of female sex pheromone in male red-sided garter snakes.

    PubMed

    Parker, M Rockwell; Mason, Robert T

    2012-03-01

    Vertebrates indicate their genetic sex to conspecifics using secondary sexual signals, and signal expression is often activated by sex hormones. Among vertebrate signaling modalities, the least is known about how hormones influence chemical signaling. Our study species, the red-sided garter snake (Thamnophis sirtalis parietalis), is a model vertebrate for studying hormonal control of chemical signals because males completely rely on the female sex pheromone to identify potential mates among thousands of individuals. How sex hormones can influence the expression of this crucial sexual signal is largely unknown. We created two groups of experimental males for the first experiment: Sham (blank implants) and E2 (17β-estradiol implants). E2 males were vigorously courted by wild males in outdoor bioassays, and in a Y-maze E2 pheromone trails were chosen by wild males over those of small females and were indistinguishable from large female trails. Biochemically, the E2 pheromone blend was similar to that of large females, and it differed significantly from Shams. For the second experiment, we implanted males with 17β-estradiol in 2007 but removed the implants the following year (2008; Removal). That same year, we implanted a new group of males with estrogen implants (Implant). Removal males were courted by wild males in 2008 (implant intact) but not in 2009 (removed). Total pheromone quantity and quality increased following estrogen treatment, and estrogen removal re-established male-typical pheromone blends. Thus, we have shown that estrogen activates the production of female pheromone in adult red-sided garter snakes. This is the first known study to quantify both behavioral and biochemical responses in chemical signaling following sex steroid treatment of reptiles in the activation/organization context. We propose that the homogametic sex (ZZ, male) may possess the same targets for activation of sexual signal production, and the absence of the activator (17

  2. Gender differences in chronic HBsAg carriers in Italy: Evidence for the independent role of male sex in severity of liver disease.

    PubMed

    Stroffolini, Tommaso; Esvan, Rozenn; Biliotti, Elisa; Sagnelli, Evangelista; Gaeta, Giovanni Battista; Almasio, Piero Luigi

    2015-11-01

    It has been shown that sexual hormones have an opposite effect on hepatic fibrosis progression and hepatocellular carcinoma development. Sex differences among 2,762 chronic HBsAg carriers consecutively referring Italian hospitals in 2001 and in 2007 have been evaluated, particularly focusing on the role of gender on severity of liver disease. The overall sex ratio (males/females) was 2.6. Females were more likely born abroad and new diagnosis cases; but less likely HIV coinfected. No sex difference was observed regarding coinfection with other hepatitis viruses. The sex ratio linearly increased with increasing severity of liver disease, being 1.3 in normal ALT, 2.8 in chronic hepatitis, 3.6 in liver cirrhosis, and 6.8 in hepatocellular carcinoma. Adjustment by multiple logistic regression analysis for the confounding effect of age, alcohol intake, HDV infection, HCV infection, and BMI shows that male gender is an independent predictor of the likelihood of more severe liver disease (O.R. 1.7; C.I. 95% = 1.3-2.1). HBV-DNA levels resulted not associated with the outcome of chronic HBV infection. Despite some potential risk factors associated with liver disease, such as HBV genotype or mutations, not having been controlled for due to lack of availability, the observed sex disparity in the outcome of chronic HBV infection may support biological observation that HBV infection could be considered a sex hormone-responsive virus. PMID:26037919

  3. Continuity in sex-typed behavior from preschool to adolescence: a longitudinal population study of boys and girls aged 3-13 years.

    PubMed

    Golombok, Susan; Rust, John; Zervoulis, Karyofyllis; Golding, Jean; Hines, Melissa

    2012-06-01

    Sex-typed behavior was assessed at age 3 using the Pre-School Activities Inventory, and at age 13 using the Multidimensional Gender Identity Scale, in 54 masculine boys, 57 masculine girls, 75 feminine boys, 65 feminine girls, 61 control boys, and 65 control girls. At age 13, girls who had been masculine at age 3 felt less similar to other girls, were less content being a girl, and had greater self-efficacy for male-typed activities than control girls, and girls who had been feminine at age 3 had greater self-efficacy for female-typed activities. Boys who had been feminine at age 3 felt less similar to other boys and had lower self-efficacy for male-typed activities than control boys at age 13, and boys who had been masculine at age 3 felt more competent in agentic roles. Thus, sex-typed behavior at age 3 predicted sex-typed behavior at age 13. It was concluded that the degree of sex-typed behavior shown by preschool children is a good indicator of their degree of sex-typed behavior following the transition to adolescence. PMID:21681691

  4. Stone Composition as a Function of Age and Sex

    PubMed Central

    Rule, Andrew D.; Krambeck, Amy E.; Williams, James C.; Bergstralh, Eric J.; Mehta, Ramila A.; Moyer, Thomas P.

    2014-01-01

    Background and objectives Kidney stones are heterogeneous but often grouped together. The potential effects of patient demographics and calendar month (season) on stone composition are not widely appreciated. Design, setting, participants, & measurements The first stone submitted by patients for analysis to the Mayo Clinic Metals Laboratory during 2010 was studied (n=43,545). Stones were classified in the following order: any struvite, any cystine, any uric acid, any brushite, majority (≥50%) calcium oxalate, or majority (≥50%) hydroxyapatite. Results Calcium oxalate (67%) was the most common followed by hydroxyapatite (16%), uric acid (8%), struvite (3%), brushite (0.9%), and cystine (0.35%). Men accounted for more stone submissions (58%) than women. However, women submitted more stones than men between the ages of 10–19 (63%) and 20–29 (62%) years. Women submitted the majority of hydroxyapatite (65%) and struvite (65%) stones, whereas men submitted the majority of calcium oxalate (64%) and uric acid (72%) stones (P<0.001). Although calcium oxalate stones were the most common type of stone overall, hydroxyapatite stones were the second most common before age 55 years, whereas uric acid stones were the second most common after age 55 years. More calcium oxalate and uric acid stones were submitted in the summer months (July and August; P<0.001), whereas the season did not influence other stone types. Conclusions It is well known that calcium oxalate stones are the most common stone type. However, age and sex have a marked influence on the type of stone formed. The higher number of stones submitted by women compared with men between the ages of 10 and 29 years old and the change in composition among the elderly favoring uric acid have not been widely appreciated. These data also suggest increases in stone risk during the summer, although this is restricted to calcium oxalate and uric acid stones. PMID:25278549

  5. Age and growth of the mutton hamlet Alphestes afer, with a review of the size and age of sex change among epinephelids.

    PubMed

    Marques, S; Ferreira, B P

    2016-07-01

    This paper presents results on the age, growth and population structure of a small grouper, the mutton hamlet Alphestes afer, and discusses the observed size and age structure patterns in relation to reproductive strategies among the epinephelids. Ages were determined by examination of sectioned otoliths, which showed a distinct pattern of alternating translucent and opaque zones that formed annually, as validated with tetracycline labelling. The von Bertalanffy growth function was adjusted to the length-at-age data of the males and females, but no significant differences were observed between the resulting parameters. The females, however, were older at given sizes and attained larger sizes and ages, with a maximum observed longevity of 13 years and a total length (LT ) of 26 cm, while the males attained maximum longevities of only 10 years and a 22 cm maximum LT . The LT and age range for the sex change was 16-25 cm and 3-11 years. The total mortality rate (Z) was estimated to be 0·55 for females and 0·82 for males. With the males younger and smaller than the females, this species differed from the pattern commonly observed for protogynous epinephelids. Males had slower growth after maturation, probably due to energy allocation to sperm production during sexual development. This study shows that demography is an important tool to understand the pathways for reproductive strategies in grouper populations. PMID:27073155

  6. Effects of age and sex on cerebrovascular function in the rat middle cerebral artery

    PubMed Central

    2014-01-01

    Background Although the mechanisms underlying the beneficial effects of estrogen on cerebrovascular function are well known, the age-dependent deleterious effects of estrogen are largely unstudied. It was hypothesized that age and sex interact in modulating cerebrovascular reactivity to vasopressin (VP) by altering the role of prostanoids in vascular function. Methods Female (F) Sprague–Dawley rats approximating key stages of “hormonal aging” in humans were studied: premenopausal (mature multigravid, MA, cyclic, 5–6 months) and postmenopausal (reproductively senescent, RS, acyclic, 10–12 months). Age-matched male (M) rats were also studied. Reactivity to VP (10−12–10−7 M) was measured in pressurized middle cerebral artery segments in the absence or presence of selective inhibitors of COX-1 (SC560, SC, 1 μM) or COX-2 (NS398, NS, 10 μM). VP-stimulated release of PGI2 and TXA2 were measured using radioimmunoassay of 6-keto-PGF1α and TXB2 (stable metabolites, pg/mg dry wt/45 min). Results In M, there were no changes in VP-induced vasoconstriction with age. Further, there were no significant differences in basal or in low- or high-VP-stimulated PGI2 or TXA2 production in younger or older M. In contrast, there were marked differences in cerebrovascular reactivity and prostanoid release with advancing age in F. Older RS F exhibited reduced maximal constrictor responses to VP, which can be attributed to enhanced COX-1 derived dilator prostanoids. VP-induced vasoconstriction in younger MA F utilized both COX-1 and COX-2 derived constrictor prostanoids. Further, VP-stimulated PGI2 and TXA2 production was enhanced by endogenous estrogen and decreased with advancing age in F, but not in M rats. Conclusions This is the first study to examine the effects of age and sex on the mechanisms underlying cerebrovascular reactivity to VP. Interestingly, VP-mediated constriction was reduced by age in F, but was unchanged in M rats. Additionally, it was observed

  7. Age- and Sex-Associated Effects on Acute-Phase Proteins in Göttingen Minipigs

    PubMed Central

    Christoffersen, Berit Ø; Jensen, Søren J; Ludvigsen, Trine P; Nilsson, Sara K; Grossi, Anette B; Heegaard, Peter M H

    2015-01-01

    Göttingen minipigs are a useful model for diseases having an inflammatory component, and the associated use of acute-phase proteins (APP) as biomarkers of inflammation warrants establishment of their reference ranges. The objective of this study was to establish reference values for selected APP in Göttingen minipigs and to investigate the effects of age, sex, and various stimuli on these ranges. Serum concentrations of C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin, pig major acute-phase protein (PMAP), albumin, and porcine α-1 acid glycoprotein (PAGP) were evaluated in 4 age groups (6, 16, 24 and 40–48 wk) of male and female Göttingen minipigs. In addition, minipigs were tested under 2 housing conditions, after acute LPS challenge, and after diet-induced obesity with and without mild diabetes. Changing the pigs to a new environment induced significant increases in CRP, PMAP, haptoglobin and PAGP and a decrease in albumin. An acute LPS stimulus increased CRP, PMAP, haptoglobin, and SAA; PAGP was unchanged and albumin decreased. Obese pigs with and without diabetes showed increases in CRP and PAGP, albumin decreased, and haptoglobin and SAA were unchanged. PMAP was increased only in obese pigs without diabetes. In conclusion, reference values for CRP, PMAP, haptoglobin, SAA, PAGP and albumin were established for male and female Göttingen minipigs of different ages. These APP were influenced by age and sex, underlining the importance of considering these factors when designing and interpreting studies including aspects of inflammation. In addition, an APP response was verified after both acute and chronic stimuli. PMID:26310463

  8. Estimating ages of white-tailed deer: Age and sex patterns of error using tooth wear-and-replacement and consistency of cementum annuli

    USGS Publications Warehouse

    Samuel, Michael D.; Storm, Daniel J.; Rolley, Robert E.; Beissel, Thomas; Richards, Bryan J.; Van Deelen, Timothy R.

    2014-01-01

    The age structure of harvested animals provides the basis for many demographic analyses. Ages of harvested white-tailed deer (Odocoileus virginianus) and other ungulates often are estimated by evaluating replacement and wear patterns of teeth, which is subjective and error-prone. Few previous studies however, examined age- and sex-specific error rates. Counting cementum annuli of incisors is an alternative, more accurate method of estimating age, but factors that influence consistency of cementum annuli counts are poorly known. We estimated age of 1,261 adult (≥1.5 yr old) white-tailed deer harvested in Wisconsin and Illinois (USA; 2005–2008) using both wear-and-replacement and cementum annuli. We compared cementum annuli with wear-and-replacement estimates to assess misclassification rates by sex and age. Wear-and-replacement for estimating ages of white-tailed deer resulted in substantial misclassification compared with cementum annuli. Age classes of females were consistently underestimated, while those of males were underestimated for younger age classes but overestimated for older age classes. Misclassification resulted in an impression of a younger age-structure than actually was the case. Additionally, we obtained paired age-estimates from cementum annuli for 295 deer. Consistency of paired cementum annuli age-estimates decreased with age, was lower in females than males, and decreased as age estimates became less certain. Our results indicated that errors in the wear-and-replacement techniques are substantial and could impact demographic analyses that use age-structure information. 

  9. Sex- and age-related differences in the timing and body condition of migrating Reed Warblers Acrocephalus scirpaceus and Sedge Warblers Acrocephalus schoenobaenus

    NASA Astrophysics Data System (ADS)

    Jakubas, Dariusz; Wojczulanis-Jakubas, Katarzyna

    2010-05-01

    The migration strategies of birds may vary strongly between species and also between age and/or sex groups. We studied the autumn migration and body condition of molecularly sexed Reed Warblers Acrocephalus scirpaceus and Sedge Warblers Acrocephalus schoenobaenus (211 and 208 ind., respectively) at a stopover site on Lake Druzno, Northern Poland, in 2008. Immature male Reed Warblers were caught significantly later than females (median dates 9 days later), but in the Sedge Warbler, both sexes of immatures migrated at about the same time. Adult males and females of both species did not differ in their time of migration. Adult and immature males of both species were larger (wing length and body mass) than females. In both species, fat reserves were similar in both sexes of both age classes. Adults of both sexes of Reed and Sedge Warbler were generally caught earlier than immatures. In both species, the body mass and fat reserves of immatures were generally less than in adults. The autumn protogyny of immature Reed Warblers may allow smaller females to limit competition with bigger males during migration and at the wintering grounds. In the Sedge Warbler, which tends to match its migration to peak of occurrence of superabundant food at stopover sites, both sexes gain an advantage from migrating at the same time. Since part of the measured wing length variation in both species was explained by sex differences, temporal trends in wing length recorded at stopover sites should be interpreted with caution.

  10. [Sleep habits of medical students, physicians and nurses regarding age, sex, shift work and caffein consumption].

    PubMed

    Pecotić, Renata; Valić, Maja; Kardum, Goran; Sevo, Vana; Dogas, Zoran

    2008-01-01

    The aim of this study was to evaluate sleep habits of nurses, medical students, and physicians and to explore whether they are influenced by age, sex, shift work, and caffeine consumption. The questionnaire was derived from the MEDSleep Survey. A total of 453 respondents were surveyed: second-year medical students (130); physicians at the postgraduate study program (68); specialists (162); nurses (93). Results of our study indicate that hours of sleep needed for feeling rested depends on age and gender. Younger respondents and women in the study need longer sleep to feel rested (7.5 hours and more) than older ones and males who need less than 7.5 hours of sleep. Among medical professionals a need for sleep differs related to work demands and work schedule. Nurses need more sleep than physicians (chi2 = 38.57, p < 0.001). Female nurses need more sleep for feeling rested than female physicians (chi2 = 18.18, p < 0.001), and sleep longer during the weeknights (chi2 = 33.78, p < 0.001) and weekends (chi2 = 28.06, p < 0.001). The respondents that consume caffeine have more trouble staying awake while listening to lectures or learning (chi2 = 9.37, p = 0.009), and while driving a car (chi2 = 14.56, p = 0.001). The results indicate that sleep habits are related to age, sex and caffeine consumption. PMID:18592966

  11. Differences in Relationship Characteristics Between HIV-Negative Male Couples Who Used and Did Not Use Substances with Sex.

    PubMed

    Mitchell, Jason W

    2016-03-01

    Although substance use is linked to HIV seroconversion, little is known about male couples substance use with sex. The present study sought to: describe whether neither, one, or both partners in the couple used a particular substance with sex within or outside their relationship; assess, by substance type used with sex, whether relationship factors differed between these groups of couples. Dyadic data from 83 behaviorally non-monogamous HIV-negative male couples were used with multinomial regression models. Those who used with sex within the relationship varied by substance type; outside the relationship, most only had one partner who used with sex. Couples with one or both partners who used substances with sex within or outside the relationship were more likely to have higher commitment to their relationship yet less likely to trust their main partner; mixed results were found regarding communication. Further research is warranted toward the need for preventive intervention development. PMID:26223222

  12. Sex differences in recovery from PTSD in male and female interpersonal assault survivors

    PubMed Central

    Galovski, Tara E.; Blain, Leah M.; Chappuis, Courtney; Fletcher, Thomas

    2013-01-01

    Men and women differ in exposure to trauma and the development of posttraumatic stress disorder (PTSD); however, research regarding sex differences in recovery from PTSD has been sparse. This study evaluated the treatment response trajectory for 69 male and female interpersonal assault survivors, using a modified Cognitive Processing Therapy (CPT) protocol that allowed survivors to receive up to18 sessions of CPT, with treatment end determined by therapy progress. Few sex differences were observed in trauma history, baseline PTSD and depressive severity, Axis I comorbidity, anger, guilt and dissociation. Women did report more sexual assault in adulthood and elevated baseline guilt cognitions, whereas men reported more baseline anger directed inward. Attrition and total number of sessions did not differ by sex. Over the course of treatment and follow-up, men and women demonstrated similar rates of change in PTSD and depressive symptoms. However, medium effect sizes on both of these primary outcomes at the 3-month follow-up assessment favored women. Several differences in the slope of change emerged on secondary outcomes such that women evidenced more rapid gains on global guilt, guilt cognitions, anger/irritability, and dissociation. Results suggest that male survivors may warrant additional attention to address these important clinical correlates. PMID:23510841

  13. Fine structure and meiotic behaviour of the male multiple sex chromosomes in the genus Alouatta.

    PubMed

    Solari, A J; Rahn, M I

    2005-01-01

    The meiotic cytology and fine structure of the sex multiples in males from two species of the genus Alouatta are presented and compared with descriptions from other species of this genus. As shown in pachytene by synaptonemal complex analysis and in metaphase I by spreading, there is a quadrivalent in male meiosis in A. caraya, which is formed by an X(1)X(2)Y(1)Y(2) complex, while in A. palliata there is a trivalent formed by an X(1)X(2)Y(1) complex. Chromosome painting with human probes shows that A. caraya sex multiples share the same components as those of A. seniculus sara and A. seniculus arctoidea. However, as shown here for A. palliata and by others in A. fusca, there are differences among the multiples of some species. It is shown that in this genus there are several varieties of sex multiples that share some features, and that the origin of these multiples is most probably a primitive development in the genus Alouatta. PMID:15545739

  14. Age- and sex-related effects in German cockroaches fed an allopurinol diet (Dictyoptera: Blattellidae).

    PubMed

    Suiter, D R; Koehler, P G; Patterson, R S

    1993-09-01

    The effects of feeding several ages of adult and nymphal German cockroaches a laboratory rat chow diet containing 0.10% allopurinol were investigated. All cockroaches fed the allopurinol diet suffered increased mortality. The range of LT50 values (the time required to kill 50% of an experimental cohort) for four ages of nymphs (1-8, 16-23, 21-28, and 28-35 d old following hatch) continuously fed the allopurinol diet was 1.36 wk (4.72-6.08 wk). Regardless of sex, young adult (1-7 d old following eclosion) cockroaches fed the allopurinol diet died significantly sooner than older adults (28-35 d old following eclosion); males died significantly sooner than females. All females fed the allopurinol diet as nymphs aborted their oothecae. Although an initial ootheca were hatched from cockroaches fed the allopurinol diet as adults, all subsequent oothecae were aborted. Untreated females mated with allopurinol-fed males experienced successful reproduction, but allopurinol-fed females mated with either allopurinol- or control diet-fed males failed to reproduce. Evidence suggests that cockroaches suffer increased mortality and reproductive failure from increased levels of hypoxanthine and xanthine. PMID:8254639

  15. Aging and male reproductive function: a mitochondrial perspective.

    PubMed

    Amaral, Sandra; Amaral, Alexandra; Ramalho-Santos, Joao

    2013-01-01

    Researching the effects of aging in the male reproductive system is not trivial. Not only are multiple changes at molecular, cellular and endocrine levels involved, but any findings must be discussed with variable individual characteristics, as well as with lifestyle and environmental factors. Age-related changes in the reproductive system include any aspect of reproductive function, from deregulation of the hypothalamic-pituitary-gonadal axis and of local auto/paracrine interactions, to effects on testicular stem cells, defects in testicular architecture and spermatogenesis, or sperm with decreased functionality. Several theories place mitochondria at the hub of cellular events related to aging, namely regarding the accumulation of oxidative damage to cells and tissues, a process in which these organelles play a prominent role, although alternative theories have also emerged. However, oxidative stress is not the only process involved in mitochondrial-related aging; mitochondrial energy metabolism, changes in mitochondrial DNA or in mitochondrial-dependent testosterone production are also important. Crucially, all these issues are likely interdependent. We will review evidence that suggests that mitochondria constitute a common link between aging and fertility loss. PMID:23277044

  16. Age estimation from the acetabulum in South African black males.

    PubMed

    Botha, D; Pretorius, S; Myburgh, J; Steyn, M

    2016-05-01

    Anthropologists are constantly seeking to improve methods for age estimation in the human skeleton. A new method was introduced about a decade ago that assesses the morphological changes that take place in the acetabulum as an individual ages. The pelvis is usually well preserved in forensic cases, which makes this method potentially valuable as an adult age indicator. This method employs seven variables, each with its own set of phases. To test the accuracy and reliability of this method, 100 black South African male acetabula from the Pretoria Bone Collection were assessed based on the criteria described in the original study. Box plots and transition curves were constructed to establish whether progression with age was visible and how it could possibly be modelled. Inter-observer reliability was also assessed by making use of Fleiss's Kappa statistic. Five specimens were used as out-of-sample examples for which maximum likelihood (point) estimates were calculated. The results demonstrated that middle and older individuals' age estimates were vastly underestimated. Inter-observer repeatability was poor, which suggested that the classification system most likely needs to be modified. A discussion and recommendation is given for improvement of reliability and repeatability of this method. PMID:26662190

  17. Measurement non-invariance of DSM-IV narcissistic personality disorder criteria across age and sex in a population-based sample of Norwegian twins

    PubMed Central

    KUBARYCH, THOMAS S.; AGGEN, STEVEN H.; KENDLER, KENNETH S.; TORGERSEN, SVEN; REICHBORN-KJENNERUD, TED; NEALE, MICHAEL C.

    2013-01-01

    We investigated measurement non-invariance of DSM-IV narcissistic personality disorder (NPD) criteria across age and sex in a population-based cohort sample of 2794 Norwegian twins. Age had a statistically significant effect on the factor mean for NPD. Sex had a statistically significant effect on the factor mean and variance. Controlling for these factor level effects, item-level analysis indicated that the criteria were functioning differently across age and sex. After correcting for measurement differences at the item level, the latent factor mean effect for age was no longer statistically significant. The mean difference for sex remained statistically significant after correcting for item threshold effects. The results indicate that DSM-IV NPD criteria perform differently in males and females and across age. Differences in diagnostic rates across groups may not be valid without correcting for measurement non-invariance. PMID:20632257

  18. Effect of age, sex and physiological stages on hematological indices of Banni buffalo (Bubalus bubalis)

    PubMed Central

    Patel, Mehul D.; Lateef, Abdul; Das, Hemen; Patel, Ajay S.; Patel, Ajay G.; Joshi, Axay B.

    2016-01-01

    Aim: To determine the physiological baseline values for hematological indices of Banni buffalo (Bubalus bubalis) as well as to assess their alteration due to age, sex and physiological stages. Materials and Methods: A total of 42 clinically healthy Banni buffaloes were categorized into seven groups (n=6): Group I (male calves ≤1 year), Group II (bulls >1 year), Group III (female calves ≤1 year), Group IV (pregnant lactating buffaloes), Group V (non-pregnant lactating buffaloes), Group VI (pregnant dry buffaloes), and Group VII (non-pregnant dry buffaloes). Blood samples collected aseptically from all the experimental groups were analyzed employing automated hematology analyzer. The data obtained were statistically analyzed; the mean and standard deviations were calculated and set as the reference values. Results: The erythrocytic indices viz. total erythrocytes count (TEC), hemoglobin, and packed cell volume (PCV) were significantly higher in bulls as compared to that of male calves unlike mean corpuscular volume, mean corpuscular hemoglobin (MCH), and MCH concentration. The female calves had higher TEC and PCV than the adult buffaloes irrespective of sex. The total leukocyte count (TLC) and neutrophil counts in male calves were significantly lower than the bulls unlike the eosinophil, while monocyte and basophil remained unchanged with age. The TLC, differential leukocyte count and platelet count varied non-significantly among the adult female groups at different physiological stages. However, neutrophils were found to be apparently higher in lactating buffaloes. Conclusion: The present study would be helpful for physiological characterization of this unique buffalo breed of Gujarat. Further, data generated may be a tool for monitoring the health and prognosis as well as diagnosis of diseases. PMID:27051182

  19. Where have all the females gone? Male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) in alpine lakes

    NASA Astrophysics Data System (ADS)

    Žibrat, U.; Brancelj, A.

    2009-04-01

    In populations with both males and females sex-ratio is one of the driving forces of population dynamics. It influences fecundity, inbreeding and social interactions. Sex-ratio is affected by several biotic and abiotic factors, either by selective killing of one sex or by inducing migrations. In alpine lakes of Triglav National Park, Slovenia, an extremely male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) was regularly observed since 1992. We analysed population dynamics and sex-ratio of A. alpinus in three alpine lakes (Jezero v Ledvicah, Rjavo jezero and Zgornje Kriško jezero) from Triglav National Park in Slovenia. In addition to seasonal dynamics we also researched long-term changes in sex-ratio (in a period of 11 years from autumn samples) as a result of increased air-temperature, and zooplankton diurnal vertical migrations. Adults of both sexes were found to appear at the same time in the water collumn with males prevailing throughout the season. A similar trend was found in copepodites CV. The percent of adult females began increasing in late summer, when there were no more copepodites and recrutation from copepodites CV to adults stopped, while male mortality increased. All cohorts of A. alpinus were found to perform diurnal vertical migrations. Both adult and CV females remained close to the bottom during the day and migrated vertically during the night. Results of the long-term study show no changes in sex-ratio in autumn.

  20. Sex differences in the genetic architecture of lifespan in a seed beetle: extreme inbreeding extends male lifespan

    PubMed Central

    Bilde, Trine; Maklakov, Alexei A; Meisner, Katrine; la Guardia, Lucia; Friberg, Urban

    2009-01-01

    Background Sex differences in lifespan are ubiquitous throughout the animal kingdom but the causes underlying this phenomenon remain poorly understood. Several explanations based on asymmetrical inheritance patterns (sex chromosomes or mitochondrial DNA) have been proposed, but these ideas have rarely been tested experimentally. Alternatively, sexual dimorphism in lifespan could result from sex-specific selection, caused by fundamental differences in how males and females optimize their fitness by allocating resources into current and future reproduction. Results Here we used sex-specific responses to inbreeding to study the genetic architecture of lifespan and mortality rates in Callosobruchus maculatus, a seed beetle that shows sexual dimorphism in lifespan. Two independent assays revealed opposing sex-specific responses to inbreeding. The combined data set showed that inbred males live longer than outbred males, while females show the opposite pattern. Both sexes suffered reduced fitness measured as lifetime reproductive success as a result of inbreeding. Conclusion No model based on asymmetrical inheritance can explain increased male lifespan in response to inbreeding. Our results are however compatible with models based on sex-specific selection on reproductive strategies. We therefore suggest that sex-specific differences in lifespan in this species primarily result from sexually divergent selection. PMID:19200350

  1. Diversity of commercial sex among men and male-born trans people in three Peruvian cities.

    PubMed

    Nureña, César R; Zúñiga, Mario; Zunt, Joseph; Mejía, Carolina; Montano, Silvia; Sánchez, Jorge L

    2011-11-01

    In Peru, commercial sex involving men and male-born travestis, transgenders and transsexuals (CSMT) is usually represented as a dangerous practice carried out on the streets by people experiencing economic hardship and social exclusion. However, in reality little is known about the complexities of this practice in Peru. This paper presents findings from an ethnographic study of the characteristics, patterns and sociocultural aspects of CSMT in three Peruvian cities. The study included participant observation in sex work venues and interviews with 42 sex workers and 25 key informants. We found that CSMT in Peru takes many forms (some not previously described in the country) and is practised in different places by people from various socioeconomic levels. In many cases, the practice appears linked to ideals of social mobility, migratory experiences and other economic activities. In addition, the increasing use of the Internet and mobile phones has changed patterns of sex work in Peru. We review the implications of these findings for future research and public health interventions. PMID:21936651

  2. Dgcr8 and Dicer are essential for sex chromosome integrity during meiosis in males

    PubMed Central

    Modzelewski, Andrew J.; Hilz, Stephanie; Crate, Elizabeth A.; Schweidenback, Caterina T. H.; Fogarty, Elizabeth A.; Grenier, Jennifer K.; Freire, Raimundo; Cohen, Paula E.; Grimson, Andrew

    2015-01-01

    ABSTRACT Small RNAs play crucial roles in regulating gene expression during mammalian meiosis. To investigate the function of microRNAs (miRNAs) and small interfering RNAs (siRNAs) during meiosis in males, we generated germ-cell-specific conditional deletions of Dgcr8 and Dicer in mice. Analysis of spermatocytes from both conditional knockout lines revealed that there were frequent chromosomal fusions during meiosis, always involving one or both sex chromosomes. RNA sequencing indicates upregulation of Atm in spermatocytes from miRNA-deficient mice, and immunofluorescence imaging demonstrates an increased abundance of activated ATM kinase and mislocalization of phosphorylated MDC1, an ATM phosphorylation substrate. The Atm 3′UTR contains many potential microRNA target sites, and, notably, target sites for several miRNAs depleted in both conditional knockout mice were highly effective at promoting repression. RNF8, a telomere-associated protein whose localization is controlled by the MDC1–ATM kinase cascade, normally associates with the sex chromosomes during pachytene, but in both conditional knockouts redistributed to the autosomes. Taken together, these results suggest that Atm dysregulation in microRNA-deficient germ lines contributes to the redistribution of proteins involved in chromosomal stability from the sex chromosomes to the autosomes, resulting in sex chromosome fusions during meiotic prophase I. PMID:25934699

  3. Diversity of commercial sex among men and male-born trans people in three Peruvian cities

    PubMed Central

    Zúñiga, Mario; Zunt, Joseph; Mejía, Carolina; Montano, Silvia; Sánchez, Jorge L.

    2011-01-01

    In Peru, commercial sex involving men and male-born travestis, transgenders and transsexuals (CSMT) is usually represented as a dangerous practice carried out on the streets by people experiencing economic hardship and social exclusion. However, in reality little is known about the complexities of this practice in Peru. This paper presents findings from an ethnographic study of the characteristics, patterns and socio-cultural aspects of CSMT in three Peruvian cities. The study included participant observation in sex work venues and interviews with 42 sex workers and 25 key informants. We found that CSMT in Peru takes many forms (some not previously described in the country) and is practised in different places by people from various socioeconomic levels. In many cases, the practice appears linked to ideals of social mobility, migratory experiences and other economic activities. In addition, the increasing use of the internet and mobile phones has changed patterns of sex work in Peru. We review the implications of these findings for future research and public health interventions. PMID:21936651

  4. Body-image perceptions across sex and age groups.

    PubMed

    Cullari, S; Rohrer, J M; Bahm, C

    1998-12-01

    Weight dissatisfaction, body dissatisfaction, and body-image distortion measures were used with 98 fifth and eighth graders and 57 undergraduate students. Measures included the Piers-Harris Self-concept Scale and the Kids Eating Disorder Survey for the young children, the Interpersonal Behavior Survey, and a seven-item mistaken beliefs scale for the college sample. Body dissatisfaction and Body-image distortion were assessed with a figure-drawing procedure. Significant differences in both weight dissatisfaction and body dissatisfaction were found between males and females in the eighth grade and undergraduate groups. There were no significant sex differences in body-image distortion in the fifth or eighth grades, but significant differences in body-image distortion between men and women were found in the college sample. The direction of body-image distortion for both the 20 men and the 37 women was consistent with their ideal weight. In the college sample, there was a significant correlation between body-image dissatisfaction and self-confidence for the women but not for the men. PMID:9885045

  5. Effects of sex role attitudes and similarity on men's rejection of male homosexuals.

    PubMed

    Krulewitz, J E; Nash, J E

    1980-01-01

    The present study investigated reactions to homosexuals as a function of perceived attitude similarity and subjects' sex role attitudes. Male subjects, preselected on the basis of their profeminist, moderate, or antifeminist scores on the Attitude Toward Feminism Scale were assigned at random to one of the four experimental conditions. Using a standard attraction paradigm design, subjects rated a bogus "partner," who was represented as either homosexual or heterosexual and as having attitudes either similar or dissimilar to theirs. Consistent with predictions, similar partners were liked more than dissimilar partners, and heterosexual partners were liked more than homosexuals. Homosexuals were seen as more dissimilar to the subjects in all conditions. Further, liberals were more accepting of homosexuals and dissimilar partners than were traditionals. The results are discussed in terms of the relationship between sex role attitudes and tolerance of dissimilarity. PMID:7373510

  6. Modeling the suppression of sea lamprey populations by use of the male sex pheromone

    USGS Publications Warehouse

    Klassen, Waldemar; Adams, Jean V.; Twohey, Michael B.

    2005-01-01

    The suppression of sea lamprey populations, Petromyzon marinus (Linnaeus), was modeled using four different applications of the male sex pheromone: (1) pheromone-baited traps that remove females from the spawning population, (2) pheromone-baited decoys that exhaust females before they are able to spawn, (3) pheromone-enhanced sterile males that increase the proportion of non-fertile matings, and (4) camouflaging of the pheromone emitted by calling males to make it difficult for females to find a mate. The models indicated that thousands of traps or hundreds of thousands of decoys would be required to suppress a population of 100,000 animals. The potential efficacy of pheromone camouflages is largely unknown, and additional research is required to estimate how much pheromone is needed to camouflage the pheromone plumes of calling males. Pheromone-enhanced sterile males appear to be a promising application in the Great Lakes. Using this technique for three generations each of ca. 7 years duration could reduce sea lamprey populations by 90% for Lakes Huron and Ontario and by 98% for Lake Michigan, based on current trapping operations that capture 20 to 30% of the population each year.

  7. The fatty acid elongase Bond is essential for Drosophila sex pheromone synthesis and male fertility

    PubMed Central

    Ng, Wan Chin; Chin, Jacqueline S. R.; Tan, Kah Junn; Yew, Joanne Y.

    2015-01-01

    Insects use a spectacular variety of chemical signals to guide their social behaviours. How such chemical diversity arises is a long-standing problem in evolutionary biology. Here we describe the contribution of the fatty acid elongase Bond to both pheromone diversity and male fertility in Drosophila. Genetic manipulation and mass spectrometry analysis reveal that the loss of bond eliminates the male sex pheromone (3R,11Z,19Z)-3-acetoxy-11,19-octacosadien-1-ol (CH503). Unexpectedly, silencing bond expression severely suppresses male fertility and the fertility of conspecific rivals. These deficits are rescued on ectopic expression of bond in the male reproductive system. A comparative analysis across six Drosophila species shows that the gain of a novel transcription initiation site is correlated with bond expression in the ejaculatory bulb, a primary site of male pheromone production. Taken together, these results indicate that modification of cis-regulatory elements and subsequent changes in gene expression pattern is one mechanism by which pheromone diversity arises. PMID:26369287

  8. The effects of adult sex ratio on mating competition in male and female guppies (Poecilia reticulata) in two wild populations.

    PubMed

    Chuard, Pierre J C; Brown, Grant E; Grant, James W A

    2016-08-01

    When competing for mates, males typically exhibit higher rates of intrasexual aggression and courtship than females. Operational sex ratio, represented here by adult sex ratio (ASR) as a proxy, is likely the best predictor of this competition, which typically increases between members of one sex as members of the opposite sex become rarer. Moreover, in populations subject to high predation, males often decrease mating competitive behaviour due to predation risk. We explored the combined effects of ASR and population of origin (low vs. high ambient predation risk) on mating competition in male and female wild-caught Trinidadian guppies. Both male and female aggression rates increased with ASR, but the increase for males was only significant in the low-predation population. In regard to male mating tactics, courtship propensity was unaffected by ASR, while the propensity to sneak increased at male-biased ASRs. Guppies from a high predation population had lower aggression rates than their low predation counterpart, but male courtship and sneaking attempts did not differ between populations. Surprisingly, females were just as aggressive as males when competing for mates. These results highlight the trade-offs between antipredator and agonistic behaviour, which may affect sexual selection pressures in wild populations. PMID:27208810

  9. The impact of sex hormone concentrations on decision-making in females and males.

    PubMed

    Derntl, Birgit; Pintzinger, Nina; Kryspin-Exner, Ilse; Schöpf, Veronika

    2014-01-01

    Human decision-making has been frequently studied and sex differences have been reported. Interestingly, previous results of hormone concentration on decision-making are somewhat inconsistent, regarding the impact of menstrual cycle phase in women or the influence of testosterone concentration on decision-making in women and men. However, the influence of the female sex hormone concentration (estradiol, progesterone) and the impact of oral contraceptive intake have rarely been examined and data regarding the effect of daytime variations of male testosterone are lacking. Moreover if personality factors such as sensation seeking, impulsivity, and anxiety influence decision-making, sex-specific effects, act as modulators is unclear. In the present study 71 women and 45 men were enrolled. All participants performed an evaluated decision-making task measuring risk-taking behavior on the basis of contingencies (Haegler et al., 2010), which can be carried out several times without a learning effect. Saliva samples were collected to obtain estradiol, progesterone, and testosterone levels. Additionally, all participants completed questionnaires measuring various personality factors. Data analysis revealed no sex differences in decision-making and no significant impact of testosterone concentration on behavioral performance in women or men. However, a significant negative correlation between progesterone concentration of women in the luteal phase and their performance in the risk-averse condition was obtained. Interestingly, a significant correlation between trait anxiety and decision-making occurred in females and males. Despite similar risky decision-making of women and men and no influence of testosterone concentration, menstrual cycle phase showed an effect on risk taking in women. In contrary to other studies, our findings provide rather subtle evidence for hormonal influences in decision-making, which may be primarily explained by task factors. PMID:25414632

  10. The impact of sex hormone concentrations on decision-making in females and males

    PubMed Central

    Derntl, Birgit; Pintzinger, Nina; Kryspin-Exner, Ilse; Schöpf, Veronika

    2014-01-01

    Human decision-making has been frequently studied and sex differences have been reported. Interestingly, previous results of hormone concentration on decision-making are somewhat inconsistent, regarding the impact of menstrual cycle phase in women or the influence of testosterone concentration on decision-making in women and men. However, the influence of the female sex hormone concentration (estradiol, progesterone) and the impact of oral contraceptive intake have rarely been examined and data regarding the effect of daytime variations of male testosterone are lacking. Moreover if personality factors such as sensation seeking, impulsivity, and anxiety influence decision-making, sex-specific effects, act as modulators is unclear. In the present study 71 women and 45 men were enrolled. All participants performed an evaluated decision-making task measuring risk-taking behavior on the basis of contingencies (Haegler et al., 2010), which can be carried out several times without a learning effect. Saliva samples were collected to obtain estradiol, progesterone, and testosterone levels. Additionally, all participants completed questionnaires measuring various personality factors. Data analysis revealed no sex differences in decision-making and no significant impact of testosterone concentration on behavioral performance in women or men. However, a significant negative correlation between progesterone concentration of women in the luteal phase and their performance in the risk-averse condition was obtained. Interestingly, a significant correlation between trait anxiety and decision-making occurred in females and males. Despite similar risky decision-making of women and men and no influence of testosterone concentration, menstrual cycle phase showed an effect on risk taking in women. In contrary to other studies, our findings provide rather subtle evidence for hormonal influences in decision-making, which may be primarily explained by task factors. PMID:25414632

  11. Relationship characteristics and HIV transmission risk in same-sex male couples in HIV serodiscordant relationships.

    PubMed

    Starks, Tyrel J; Gamarel, Kristi E; Johnson, Mallory O

    2014-01-01

    Unprotected anal intercourse (UAI) remains a main risk factor for HIV among men who have sex with men (MSM) and this is of particular concern for partners of HIV serodiscordant status. However, HIV transmission risk has been demonstrated to vary by the sexual position adopted among partners. Guided by interdependence theory, this study examined how relational factors were differentially associated with risk taking (HIV-positive/insertive and HIV-negative/receptive) and strategic positioning (HIV-positive/receptive and HIV-negative/insertive) UAI within serodiscordant same-sex male couples. HIV-positive men and their HIV-negative partners (n couples = 91; n individuals = 182) simultaneously but independently completed computerized questionnaires and HIV-positive men had blood drawn for viral load. A minority of couples (30 %) engaged in risk taking and/or strategic positioning unprotected anal sex. Results of multinomial logistic regression indicated that HIV-negative partners' levels of relationship commitment were positively associated with the odds of engaging in strategic positioning sexual behaviors. For HIV-negative partners, reports of relationship intimacy, and sexual satisfaction were negatively associated with odds of reporting risk taking behavior. In contrast, HIV-positive partners' reported sexual satisfaction was positively associated with odds of engaging in risk taking behavior. Findings suggested that aspects of relational quality may be differentially associated with sexual decision making for same-sex male couples in serodiscordant relationships. Study findings lend support for the incorporation of discussions of HIV risk reduction strategies, enhancing communication between partners, and support for general relationship functioning in HIV care. PMID:24243004

  12. Spontaneous running activity in male rats - Effect of age

    NASA Technical Reports Server (NTRS)

    Mondon, C. E.; Dolkas, C. B.; Sims, C.; Reaven, G. M.

    1985-01-01

    Variations in the intensity and the patterns of spontaneous running activity in wheel cages were studied in male rats aged 7 weeks to one year. Daily running records were obtained for periods of 12 mo, and 24-hour recordings were made for selected runners in order to study variations in running activity during the day. The data indicate that for rats running over two miles/day, the maximum running intensity can be divided into two groups: a group of high achievers running 8 miles/day; and a group of moderate achievers running 4.8 miles/day. For both groups spontaneous activity reached a maximum after 4-5 weeks. An hourly pattern of running activity during the day was identified in rats of increasing age who averaged 9.0, 4.5, 2.6, and 1.2 miles/day, respectively. Progressive losses were observed in both the speed and the duration of spontaneous running as the rats increased in age, with the intensity of exercise falling below 2 miles/day after 7-8 months of age.

  13. Pathophysiology of Benign Prostatic Hyperplasia in the Aging Male Population

    PubMed Central

    Lepor, Herbert

    2005-01-01

    Nearly all men will develop histological benign prostatic hyperplasia by the age of 80, but the degree of prostatic enlargement resulting from the hyperplasia is highly variable. Historically, it has often been assumed that the pathophysiology of lower urinary tract symptoms (LUTS) in men is the result of bladder outlet obstruction associated with prostatic enlargement. The observation that prostatic enlargement, bladder outlet obstruction, and LUTS are all age-dependent has been interpreted to indicate that these phenomena were causally related, but there is insufficient evidence for this. Undoubtedly, some men' prostatic enlargement causes obstruction and symptoms. Based upon the available data, however, this subset appears to be extremely small. Because of the many urological and nonurological conditions that cause LUTS and age-dependent changes in bladder and neurological function, it is unlikely that there exists a single dominant etiology for the aging male population. If this is the case, then the optimal management of LUTS will require different and possibly combination therapies. PMID:16986052

  14. Plant odorants interfere with detection of sex pheromone signals by male Heliothis virescens

    PubMed Central

    Pregitzer, Pablo; Schubert, Marco; Breer, Heinz; Hansson, Bill S.; Sachse, Silke; Krieger, Jürgen

    2012-01-01

    In many insects, mate finding relies on female-released sex pheromones, which have to be deciphered by the male olfactory system within an odorous background of plant volatiles present in the environment of a calling female. With respect to pheromone-mediated mate localization, plant odorants may be neutral, favorable, or disturbing. Here we examined the impact of plant odorants on detection and coding of the major sex pheromone component, (Z)-11-hexadecenal (Z11-16:Ald) in the noctuid moth Heliothis virescens. By in vivo imaging the activity in the male antennal lobe (AL), we monitored the interference at the level of olfactory sensory neurons (OSN) to illuminate mixture interactions. The results show that stimulating the male antenna with Z11-16:Ald and distinct plant-related odorants simultaneously suppressed pheromone-evoked activity in the region of the macroglomerular complex (MGC), where Z11-16:Ald-specific OSNs terminate. Based on our previous findings that antennal detection of Z11-16:Ald involves an interplay of the pheromone binding protein (PBP) HvirPBP2 and the pheromone receptor (PR) HR13, we asked if the plant odorants may interfere with any of the elements involved in pheromone detection. Using a competitive fluorescence binding assay, we found that the plant odorants neither bind to HvirPBP2 nor affect the binding of Z11-16:Ald to the protein. However, imaging experiments analyzing a cell line that expressed the receptor HR13 revealed that plant odorants significantly inhibited the Z11-16:Ald-evoked calcium responses. Together the results indicate that plant odorants can interfere with the signaling process of the major sex pheromone component at the receptor level. Consequently, it can be assumed that plant odorants in the environment may reduce the firing activity of pheromone-specific OSNs in H. virescens and thus affect mate localization. PMID:23060749

  15. Age- and sex-specific spatio-temporal patterns of colorectal cancer mortality in Spain (1975-2008)

    PubMed Central

    2014-01-01

    In this paper, space-time patterns of colorectal cancer (CRC) mortality risks are studied by sex and age group (50-69, ≥70) in Spanish provinces during the period 1975-2008. Space-time conditional autoregressive models are used to perform the statistical analyses. A pronounced increase in mortality risk has been observed in males for both age-groups. For males between 50 and 69 years of age, trends seem to stabilize from 2001 onward. In females, trends reflect a more stable pattern during the period in both age groups. However, for the 50-69 years group, risks take an upward trend in the period 2006-2008 after the slight decline observed in the second half of the period. This study offers interesting information regarding CRC mortality distribution among different Spanish provinces that could be used to improve prevention policies and resource allocation in different regions. PMID:25136264

  16. Permanent and functional male-to-female sex reversal in d-rR strain medaka (Oryzias latipes) following egg microinjection of o,p'-DDT.

    PubMed Central

    Edmunds, J S; McCarthy, R A; Ramsdell, J S

    2000-01-01

    Complete sex reversal of fish is accomplished routinely in aquaculture practices by exposing fish to exogenous sex steroids during gonadal differentiation. A variety of environmental chemicals are also active at sex steroid receptors and theoretically possess the potential to alter normal sexual differentiation in fish. However, in controlled environmental chemical exposures to date, only partial alterations of fish sexual phenotype have been observed. Here we report complete, permanent, and functional male-to-female sex reversal in the Japanese medaka (Oryzias latipes, d-rR strain) after a onetime embryonic exposure to the xenoestrogen o, p'-DDT. d-rR strain medaka are strict gonochorists that possesses both sex-linked pigmentation, which distinguishes genotypic sex, and sexually dimorphic external secondary sexual characteristics, which distinguish phenotypic sex. We directly microinjected the xenoestrogen o, p'-DDT into the egg yolks of medaka at fertilization to parallel the maternal transfer of lipophilic contaminants to the embryo. At 10 weeks of age, microinjected medaka were examined for mortality and sex reversal. A calculated embryonic dose of 511 +/- 22 ng/egg o, p'-DDT (mean +/- standard error) resulted in 50% mortality. An embryonic exposure of 227 +/- 22 ng/egg o, p'-DDT resulted in 86% (6 of 7) sex reversal of genetic males to a female phenotype (XY females). XY females were distinguished by sex-linked male pigmentation accompanying female secondary sexual characteristics. Histologic examination of the gonads confirmed active ovaries in 100% of the XY females. In 10-day breeding trials in which XY females were paired with normal XY males, 50% of the XY females produced fertilized embryos; this represents a comparable breeding success rate to normal XX females. Fertilized eggs produced from XY females hatched to viable larvae. These results clearly indicate that a weakly estrogenic pesticide, o, p'-DDT, when presented during the critical period of

  17. Effects of Age and Sex on the Development of Personal Space Schemata Towards Body Build

    ERIC Educational Resources Information Center

    Lerner, Richard M.; And Others

    1975-01-01

    This study assessed personal space schemata of children towards stimulus figures representing male and female body build stereotypes. Greater spatial distances were used towards the Endomorph than other physique types and significant sex differences were found. (GO)

  18. Does sex (female versus male) influence the impact of class attendance on examination performance?

    PubMed

    Cortright, Ronald N; Lujan, Heidi L; Cox, Julie H; DiCarlo, Stephen E

    2011-12-01

    The "conventional wisdom" is that grades are related to class attendance, i.e., students who attend classes more frequently obtain better grades and class attendance dramatically contributes to enhanced learning. However, the influence of sex (female vs. male) on this relationship is understudied. Furthermore, there have been several studies examining the impact of attendance on course grades that challenge the conventional wisdom. To address these issues, we determined the effect of class attendance on examination scores for female and male students enrolled in our undergraduate exercise physiology class of 51 students (20 female students and 31 male students). The experiment was designed not to interfere with the normal conduct of the course. Attendance was recorded in each class, and, although regular attendance was encouraged, it was not required and did not factor into the final grades. The final grade reflected the average days of attendance for female students only. Specifically, female students earning a grade above the class average attended 89 ± 4% of the classes; however, female students earning a grade below the class average attended only 64 ± 6% of the classes. In sharp contrast, there was no difference in the number of classes attended for male students earning grades above or below the class average (84 ± 3% vs. 79 ± 5%). Accordingly, some male students were absent frequently but scored above the class average, whereas other male students attended many classes but scored below the class average. Thus, the influence of regular attendance on examination performance is more important for female students than male students. PMID:22139780

  19. [Mutagenic effect of human adenovirus type I on the somatic and sex cells of male mice].

    PubMed

    Podol'skaia, S V

    1986-01-01

    Human adenovirus 1 was studied for its effect on the chromosomal apparatus both in bone marrow cells and male sex cells of mice. Chromosome aberrations were most early detected in spermatocytes of the 1st order mice infected with human adenovirus 1. In bone marrow cells of mice the highest level of chromosome aberrations was observed 30, 60, 90 days after the inoculation, which corresponds to a more frequent detection of the adenoviral antigen. The UV-irradiated-virus caused chromosome aberrations in the later periods after the inoculation which might be induced by the virus reactivation in a cell. PMID:3705168

  20. Burden of HIV and Syphilis: A Comparative Evaluation between Male Sex Workers and Non-Sex-Worker Men Who Have Sex with Men in Urban China

    PubMed Central

    Tang, Weiming; Mahapatra, Tanmay; Liu, Fengying; Fu, Gengfeng; Yang, Bin; Tucker, Joseph D.; Zhao, Jinkou; Detels, Roger

    2015-01-01

    Background The increasing burden of sexually transmitted infections (STIs) including HIV and syphilis among male sex workers (MSWs) is a major global concern. The aim of our study was to evaluate the difference between MSWs and non-commercial MSMs in China. Methods During 2008-09, in a cross-sectional study, 2618 adult MSM were recruited through respondent-driven and snowball sampling from seven cities of China. Information regarding socio-demographics, risk behaviors, HIV-related knowledge and STI-related symptoms were collected and participants were tested for HIV and syphilis. Results Among 2618 participating MSM, 9.97% sold sex to males. HIV prevalence was 7.45% (6.13% among MSWs and 7.59% among non-MSW MSM) and syphilis prevalence was 14.32% (10.73% for MSWs and 14.72% for non-MSW MSM). Compared to non-MSW MSM, MSWs were more likely to be younger (adjusted odds ratio: aOR = 0.91, 95% confidence interval: 95%CI=0.88-0.93), never married (aOR = 4.38, 95% CI = 2.38-6.80), less educated, heterosexual (aOR = 13.04, 95% CI = 6.08-27.95), less knowledgeable regarding HIV (aOR = 0.70, 95% CI=0.51-0.96), experiencing symptoms of STI (aOR = 2.16, 95% CI = 1.47-3.19), engaging in condomless vaginal intercourse (aOR = 2.16, 95% CI = 1.47-3.19) and less likely to engage in condomless anal intercourse (aOR = 0.62, 95% CI = 0.46-0.85). Conclusions High HIV and syphilis prevalence warranted urgent intervention targeting MSWs as a separate sentinel group for efficient surveillance owing to their different distribution from non-MSW MSM. Although male sex workers and non-commercial homosexuals have similar rates of HIV and syphilis, MSWs have different characteristics which should be considered in designing intervention programs targeting them. PMID:25961721

  1. Differences in Retinal Structure and Function between Aging Male and Female Sprague-Dawley Rats are Strongly Influenced by the Estrus Cycle

    PubMed Central

    Chaychi, Samaneh; Polosa, Anna; Lachapelle, Pierre

    2015-01-01

    Purpose Biological sex and age are considered as two important factors that may influence the function and structure of the retina, an effect that might be governed by sexual hormones such as estrogen. The purpose of this study was to delineate the influence that biological sex and age exert on the retinal function and structure of rodents and also clarify the effect that the estrus cycle might exert on the retinal function of female rats. Method The retinal function of 50 normal male and female albino Sprague-Dawley (SD) rats was investigated with the electroretinogram (ERG) at postnatal day (P) 30, 60, 100, 200, and 300 (n = 5–6 male and female rats/age). Following the ERG recording sessions, retinal histology was performed in both sexes. In parallel, the retinal function of premenopausal and menopausal female rats aged P540 were also compared. Results Sex and age-related changes in retinal structure and function were observed in our animal model. However, irrespective of age, no significant difference was observed in ERG and retinal histology obtained from male and female rats. Notwithstanding the above we did however notice that between P60 and P200 there was a gradual increase in ERG amplitudes of female rats compared to males. Furthermore, the ERG of premenopausal female rats aged 18 months old (P540) was larger compared to age-matched menopausal female rats as well as that of male rats. Conclusion Our results showed that biological sex and age can influence the retinal function and structure of albino SD rats. Furthermore, we showed that cycled female rats have better retinal function compared to the menopausal female rats suggesting a beneficial effect of the estrus cycle on the retinal function. PMID:26317201

  2. Correlation of patient's mental attitude with age, sex, and educational level: A survey

    PubMed Central

    Choudhary, Shweta; Kumar, Ajit; Arora, Himanshu

    2016-01-01

    Objective: The aim of this study was to determine any relationship, if exists, between the patient's mental attitude with age, sex, or educational qualification. Methods: A total of 200 patients who attended the outpatient department during a span of 1 year, for the fabrication of new complete dentures, were chosen for the study. After completing a routine case history and examination, a questionnaire was filled by the clinician as answered by the patient. Participants were evaluated and categorized based on the questionnaire and clinical experience during treatment according to a predefined classification of determining mental attitudes. Outcomes from the survey were correlated with participant gender, age, and educational status. Results: The male to female ratio was 83:117, out of the 200 enrolled participants. The results from the questionnaire showed that females were found to be more exacting (P = 0.007) in nature, while males, on the other hand, revealed more indifferent attitude (P = 0.02); both differences being statistically significant. Of the three age group categories: Participants in the age group of 45–54 years revealed a significant inclination toward an exacting attitude when compared with other age groups (P < 0.001). In regards to educational status, an illiterate or minimally educated group significantly outnumbered the college graduates in the indifferent attitude group (P < 0.001). Conclusions: Within the limitations of this study, it could be said that the mental attitudes of patients could vary according to gender, age, and educational status, which could affect patient cooperation and satisfaction with oral rehabilitation, eventually manipulating the overall success of the treatment rendered. PMID:27011735

  3. Sex-specific age association with primary DNA transfer.

    PubMed

    Manoli, Panayiotis; Antoniou, Antonis; Bashiardes, Evy; Xenophontos, Stavroulla; Photiades, Marinos; Stribley, Vaso; Mylona, Michalis; Demetriou, Christiana; Cariolou, Marios A

    2016-01-01

    Practicing forensic scientists who are called to provide expert witness testimony are often asked to explain both the presence and the absence of DNA on objects that have been handled by perpetrators with bare hands. Unwashed hands, depending on what they have come in contact with previously, may become the vehicle of both primary and secondary transfer of DNA. In this study, we investigated the propensity of primary and secondary transfer of DNA from unwashed bare hands of 128 individuals onto plastic tubes. Our experiments, carried out in triplicate, have shown that DNA was not detected on all the touched tubes, secondary transfer of DNA, through unwashed hands, was small, and in the majority of cases primary DNA transfer could be distinguished from secondary DNA transfer. A statistically significant association was demonstrated between percent DNA profile deposited on plastic tubes, through unwashed hands, and the age of male individuals. PMID:26582043

  4. Differential Interactions of Sex Pheromone and Plant Odour in the Olfactory Pathway of a Male Moth

    PubMed Central

    Deisig, Nina; Kropf, Jan; Vitecek, Simon; Pevergne, Delphine; Rouyar, Angela; Sandoz, Jean-Christophe; Lucas, Philippe; Gadenne, Christophe

    2012-01-01

    Most animals rely on olfaction to find sexual partners, food or a habitat. The olfactory system faces the challenge of extracting meaningful information from a noisy odorous environment. In most moth species, males respond to sex pheromone emitted by females in an environment with abundant plant volatiles. Plant odours could either facilitate the localization of females (females calling on host plants), mask the female pheromone or they could be neutral without any effect on the pheromone. Here we studied how mixtures of a behaviourally-attractive floral odour, heptanal, and the sex pheromone are encoded at different levels of the olfactory pathway in males of the noctuid moth Agrotis ipsilon. In addition, we asked how interactions between the two odorants change as a function of the males' mating status. We investigated mixture detection in both the pheromone-specific and in the general odorant pathway. We used a) recordings from individual sensilla to study responses of olfactory receptor neurons, b) in vivo calcium imaging with a bath-applied dye to characterize the global input response in the primary olfactory centre, the antennal lobe and c) intracellular recordings of antennal lobe output neurons, projection neurons, in virgin and newly-mated males. Our results show that heptanal reduces pheromone sensitivity at the peripheral and central olfactory level independently of the mating status. Contrarily, heptanal-responding olfactory receptor neurons are not influenced by pheromone in a mixture, although some post-mating modulation occurs at the input of the sexually isomorphic ordinary glomeruli, where general odours are processed within the antennal lobe. The results are discussed in the context of mate localization. PMID:22427979

  5. Plasma electrophoretic profiles and hemoglobin binding protein reference intervals in the eastern box turtle (Terrapene carolina carolina) and influences of age, sex, season, and location.

    PubMed

    Flower, Jennifer E; Byrd, John; Cray, Carolyn; Allender, Matthew C

    2014-12-01

    Evaluation of plasma electrophoretic profiles and acute phase protein concentrations may play a valuable role in health assessment of reptiles; however, little is known about reference intervals in free-ranging eastern box turtles (Terrapene carolina carolina). The purpose of this study was to establish reference intervals of protein electrophoretic profiles and hemoglobin binding protein ([HBP] as determined by a haptoglobin assay) in free-ranging eastern box turtles and to assess any possible correlations between varying age class (adults vs. juvenile), sex (male, female, or unknown), season (spring, summer, or fall), or location (Tennessee vs. Illinois). Blood samples were obtained from 324 eastern box turtles from 2010 to 2012 at three sites in Illinois and one site in Tennessee, USA. Significant differences were observed with total protein (sex, season, state, Illinois location), albumin (age class, season, state, Illinois location), α-1 globulins (sex, season, Illinois location), α-2 globulins (sex, season, state, Illinois location), β globulins (age class, sex, season, state, Illinois location), γ globulins (sex, season state, Illinois location), and hemoglobin binding protein (age class, sex, state, Illinois location). The use of electrophoretic profiles and acute phase proteins is a relatively new concept in reptilian medicine, and this study allowed for establishment of references intervals in the eastern box turtle and emphasized differences that occured based on age, sex, season, and location. Future research in this area can now build on these data to determine changes in population health over time or alterations due to specific environmental or disease threats. PMID:25632671

  6. Social Deficits in Male Children and Adolescents with Sex Chromosome Aneuploidy: A Comparison of XXY, XYY, and XXYY Syndromes

    ERIC Educational Resources Information Center

    Cordeiro, Lisa; Tartaglia, Nicole; Roeltgen, David; Ross, Judith

    2012-01-01

    We compare social skills in three groups of males with sex chromosome aneuploidies (SCAs) using the Social Responsiveness Scale (SRS). Participants included males with XXY (N = 102, M = 10.08 years), XYY (N = 40, M = 9.93 years), and XXYY (N = 32, M = 11.57 years). XXY had lower (better) SRS scores compared to XYY and XXYY. Scores were not…

  7. Traumagenic Dynamics in Adult Women Survivors of Childhood Sexual Abuse vs. Adolescent Male Sex Offenders with Similar Histories.

    ERIC Educational Resources Information Center

    Edwards, Carla; Hendrix, Rebecca

    2001-01-01

    Female childhood sexual abuse survivors and adolescent male sexual offenders with a history of childhood sexual abuse were assessed using the Trauma-Related Beliefs Questionnaire. Results suggested that male sex offenders hold high levels of traumagenic beliefs common in females, especially related to trust and betrayal. (Author)

  8. Androgenic control of male-typical behavior, morphology and sex recognition is independent of the mode of sex determination: A case study on Lichtenfelder's gecko (Eublepharidae: Goniurosaurus lichtenfelderi).

    PubMed

    Golinski, Alison; Kubička, Lukáš; John-Alder, Henry; Kratochvíl, Lukáš

    2015-06-01

    Previous work on lizards has shown that many sexually dimorphic traits depend on testosterone (T), but the details of this control can vary among species. Here, we tested the role of T on the expression of morphological, physiological, and behavioral traits in Lichtenfelder's gecko (Goniurosaurus lichtenfelderi), from the lizard family Eublepharidae notable for interspecific variation in sexually dimorphic traits and the mode of sex determination. Experiments included three groups of males (intact control, surgically castrated, castrated with T replacement) and two groups of females (intact control, T supplemented). In males, castration caused reductions in 1) the size of hemipenes, 2) offensive aggression, 3) male sexual behavior in a neutral arena, 4) activity of precloacal glands, and 5) loss of male chemical cues for sex recognition. These reductions were not observed in castrated males with T replacement. Interestingly, castrated males performed sexual behavior in their home cages, which shows that the effect of T depends on the environmental context. Notably, tail vibration, previously reported as a courtship behavior in other eublepharids, is displayed by males of G. lichtenfelderi during interactions with conspecifics of both sexes, suggesting an evolutionary shift in the meaning of this signal. In females, T induced growth of hemipenes and male-typical courtship but did not induce precloacal pore activity, aggression, or mounting. In comparison to previous reports on Eublepharis macularius, our results indicate that effects of T do not depend on the mode of sex determination. Further, our results extend our understanding of the complexity of control of male traits and illustrate how lability in the effects of T can be a general mechanism causing evolutionary changes in the components of suites of functionally correlated traits. PMID:25967849

  9. Incorporating harvest rates into the sex-age-kill model for white-tailed deer

    USGS Publications Warehouse

    Norton, Andrew S.; Diefenbach, Duane R.; Rosenberry, Christopher S.; Wallingford, Bret D.

    2013-01-01

    Although monitoring population trends is an essential component of game species management, wildlife managers rarely have complete counts of abundance. Often, they rely on population models to monitor population trends. As imperfect representations of real-world populations, models must be rigorously evaluated to be applied appropriately. Previous research has evaluated population models for white-tailed deer (Odocoileus virginianus); however, the precision and reliability of these models when tested against empirical measures of variability and bias largely is untested. We were able to statistically evaluate the Pennsylvania sex-age-kill (PASAK) population model using realistic error measured using data from 1,131 radiocollared white-tailed deer in Pennsylvania from 2002 to 2008. We used these data and harvest data (number killed, age-sex structure, etc.) to estimate precision of abundance estimates, identify the most efficient harvest data collection with respect to precision of parameter estimates, and evaluate PASAK model robustness to violation of assumptions. Median coefficient of variation (CV) estimates by Wildlife Management Unit, 13.2% in the most recent year, were slightly above benchmarks recommended for managing game species populations. Doubling reporting rates by hunters or doubling the number of deer checked by personnel in the field reduced median CVs to recommended levels. The PASAK model was robust to errors in estimates for adult male harvest rates but was sensitive to errors in subadult male harvest rates, especially in populations with lower harvest rates. In particular, an error in subadult (1.5-yr-old) male harvest rates resulted in the opposite error in subadult male, adult female, and juvenile population estimates. Also, evidence of a greater harvest probability for subadult female deer when compared with adult (≥2.5-yr-old) female deer resulted in a 9.5% underestimate of the population using the PASAK model. Because obtaining

  10. Identification and validation of a new male sex-specific ISSR marker in pointed gourd (Trichosanthes dioica Roxb.).

    PubMed

    Adhikari, Sinchan; Saha, Soumen; Bandyopadhyay, Tapas Kumar; Ghosh, Parthadeb

    2014-01-01

    The aim of the present study was to develop a genetic sex marker for the pointed gourd (Trichosanthes dioica Roxb.) to allow gender determination at any stage in the life cycle. Screening of genomic DNA with intersimple sequence repeat (ISSR) primers was used to discover sex-specific touch-down polymerase chain reaction (Td-PCR) amplification products. Using pooled DNA from male and female genotypes and 42 ISSR primers, a putative male specific marker (~550 bp) was identified. DNA marker specific to male is an indication of existence of nonepigenetic factors involved in gender development in pointed gourd. The ISSR technique has proved to be a reliable technique in gender determination of pointed gourd genotypes at the seedling phenophase. The sex marker developed here could also be used as a starting material towards sequence characterization of sex linked genes for better understanding the developmental as well as evolutionary pathways in sexual dimorphism. PMID:25538949

  11. Identification and Validation of a New Male Sex-Specific ISSR Marker in Pointed Gourd (Trichosanthes dioica Roxb.)

    PubMed Central

    Adhikari, Sinchan; Saha, Soumen; Bandyopadhyay, Tapas Kumar

    2014-01-01

    The aim of the present study was to develop a genetic sex marker for the pointed gourd (Trichosanthes dioica Roxb.) to allow gender determination at any stage in the life cycle. Screening of genomic DNA with intersimple sequence repeat (ISSR) primers was used to discover sex-specific touch-down polymerase chain reaction (Td-PCR) amplification products. Using pooled DNA from male and female genotypes and 42 ISSR primers, a putative male specific marker (~550 bp) was identified. DNA marker specific to male is an indication of existence of nonepigenetic factors involved in gender development in pointed gourd. The ISSR technique has proved to be a reliable technique in gender determination of pointed gourd genotypes at the seedling phenophase. The sex marker developed here could also be used as a starting material towards sequence characterization of sex linked genes for better understanding the developmental as well as evolutionary pathways in sexual dimorphism. PMID:25538949

  12. Symptoms and lung function decline in a middle-aged cohort of males and females in Australia

    PubMed Central

    Abramson, Michael J; Kaushik, Sonia; Benke, Geza P; Borg, Brigitte M; Smith, Catherine L; Dharmage, Shyamali C; Thompson, Bruce R

    2016-01-01

    Background The European Community Respiratory Health Survey is a major international study designed to assess lung health in adults. This Australian follow-up investigated changes in symptoms between sexes and the roles of asthma, smoking, age, sex, height, and change in body mass index (ΔBMI) on lung function decline (LFD), which is a major risk factor for chronic obstructive pulmonary disease (COPD). Methods LFD was measured as the rate of decline over time in FEV1 (mL/year) (ΔFEV1) and FVC (ΔFVC) between 1993 and 2013. Multiple linear regression was used to estimate associations between risk factors and LFD, separately for males and females. Multiple logistic regression was used to assess sex differences and changes in respiratory symptoms over time. Results In Melbourne, 318 subjects (53.8% females) participated. The prevalence of most respiratory symptoms had either remained relatively stable over 20 years or decreased (significantly so for wheeze). The exception was shortness of breath after activity, which had increased. Among the 262 subjects who completed spirometry, current smoking declined from 20.2% to 7.3%. Overall mean (± standard deviation) FEV1 declined by 23.1 (±17.1) and FVC by 22.9 (±20.2) mL/year. Predictors of ΔFEV1 in males were age, maternal smoking, and baseline FEV1; and in females they were age, ΔBMI, baseline FEV1, and pack-years in current smokers. Decline in FVC was predicted by baseline FVC, age, and ΔBMI in both sexes; however, baseline FVC predicted steeper decline in females than males. Conclusion Most respiratory symptoms remained stable or decreased over time in both sexes. Age, baseline lung function, and change in BMI were associated with the rate of decline in both sexes. However, obesity and personal smoking appear to put females at higher risk of LFD than males. Health promotion campaigns should particularly target females to prevent COPD. PMID:27307725

  13. Sex and condom use in a large jail unit for men who have sex with men (MSM) and male-to-female transgenders.

    PubMed

    Harawa, Nina T; Sweat, Jeffery; George, Sheba; Sylla, Mary

    2010-08-01

    Few data are available on factors contributing to sexual activity and condom use in custody settings, particularly among self-identified sexual minority prisoners. To address this gap, we undertook a study of sexual behavior and condom use of 101 randomly-selected men who have sex with men (MSM) and male-to-female transgender inmates in a segregated Los Angeles jail unit that has weekly condom access. Most survey participants (53%) reported anal sex during custody. Although 65% of these reported using condoms, 75% also reported having sex without condoms. Qualitative interviews (n=17) indicate a wide range of reasons for participating in protected and unprotected sex during custody, the use of cues within the custody environment to assess potential partners' HIV status, and support for increased condom availability. Findings also indicate that high-risk sex occurs frequently in this unit and that condom distribution likely prevents a substantial amount of related HIV/STD risk. PMID:20693745

  14. Human gastric alcohol dehydrogenase activity: effect of age, sex, and alcoholism.

    PubMed Central

    Seitz, H K; Egerer, G; Simanowski, U A; Waldherr, R; Eckey, R; Agarwal, D P; Goedde, H W; von Wartburg, J P

    1993-01-01

    As various isoenzymes of gastric alcohol dehydrogenase exist and as the effect of sex and age on these enzymes is unknown, this study measured the activity of gastric alcohol dehydrogenase at high and low ethanol concentrations in endoscopic biopsy specimens from a total of 290 patients of various ages and from 10 patients with chronic alcoholism. Gastric alcohol dehydrogenase was also detected by immunohistological tests in biopsy specimens from 40 patients by the use of a polyclonal rabbit antibody against class I alcohol dehydrogenase. A significant correlation was found between the immunohistological reaction assessed by the intensity of the colour reaction in the biopsy specimen and the activity of alcohol dehydrogenase measured at 580 mM ethanol. While alcohol dehydrogenase activity measured at 16 mM ethanol was not significantly affected by age and sex, both factors influenced alcohol dehydrogenase activity measured at 580 mM ethanol. Young women below 50 years of age had significantly lower alcohol dehydrogenase activities in the gastric corpus and antrum when compared with age matched controls (SEM) (6.4 (0.7) v 8.8 (0.6) nmol/min/mg protein; p < 0.001 and 6.0 (1.3) v 9.5 (1.3) nmol/min/mg protein; p < 0.001). Over 50 years of age this sex difference was no longer detectable, as high Km gastric alcohol dehydrogenase activity decreases with age only in men and not in women. In addition, extremely low alcohol dehydrogenase activities have been found in gastric biopsy specimens from young male alcoholics (2.2 (0.5) nmol/min/mg protein), which returned to normal after two to three weeks of abstinence. The activity of alcohol dehydrogenase in the human stomach measured at 580 mM ethanol is decreased in young women, in elderly men, and in the subject with alcoholism. This decrease in alcohol dehydrogenase activity may contribute to the reduced first pass metabolism of ethanol associated with raised ethanol blood concentrations seen in these people. Images Figure

  15. The Sex Attractant Pheromone of Male Brown Rats: Identification and Field Experiment.

    PubMed

    Takács, Stephen; Gries, Regine; Zhai, Huimin; Gries, Gerhard

    2016-05-10

    Trapping brown rats is challenging because they avoid newly placed traps in their habitat. Herein, we report the identification of the sex pheromone produced by male brown rats and its effect on trap captures of wild female brown rats. Collecting urine- and feces-soiled bedding material of laboratory-kept rats and comparing the soiled-bedding odorants of juvenile and adult males, as well as of adult males and females, we found nine compounds that were specific to, or most prevalent in, the odor profiles of sexually mature adult males. When we added a synthetic blend of six of these compounds (2-heptanone, 4-heptanone, 3-ethyl-2-heptanone, 2-octanone, 2-nonanone, 4-nonanone) to one of two paired food-baited trap boxes, these boxes attracted significantly more laboratory-strain female rats in laboratory experiments, and captured ten times more wild female rats in a field experiment than the corresponding control boxes. Our data show that the pheromone facilitates captures of wild female brown rats. PMID:27060700

  16. Prenatal sex hormones, digit ratio, and face shape in adult males

    PubMed Central

    Weinberg, S. M.; Parsons, T. E.; Raffensperger, Z. D.; Marazita, M. L.

    2014-01-01

    Objectives Several reports have demonstrated a relationship between second to fourth digit ratio (2D:4D) and facial shape, suggesting that prenatal sex hormones play a role in the development of the craniofacial complex. Using 3D surface imaging and geometric morphometrics, we test the hypothesis that decreased digit ratio (indicative of increased prenatal androgen exposure) is associated with a more masculine facial phenotype. Methods 3D facial surface images and digit measures were collected on a sample of 151 adult males. Facial landmarks collected from the images were aligned by Procrustes superimposition and the resulting shape coordinates regressed on 2D:4D. Variations in facial shape related to 2D:4D were visualized with deformable surface warps. Results A significant statistical relationship was observed between facial shape variation and 2D:4D (p = 0.0084). Lower 2D:4D ratio in adult males was associated with increased facial width relative to height, increased mandibular prognathism, greater nasal projection, and increased upper and lower lip projection. Conclusions A statistical relationship between 2D:4D and facial shape in adult males was observed. Faces tended to look more masculine as 2D:4D decreased, suggesting a biologically plausible link between prenatal androgen exposure and the development of male facial characteristics. PMID:25257381

  17. The Gulf War era multiple sclerosis cohort: age and incidence rates by race, sex and service.

    PubMed

    Wallin, Mitchell T; Culpepper, William J; Coffman, Parisa; Pulaski, Sarah; Maloni, Heidi; Mahan, Clare M; Haselkorn, Jodie K; Kurtzke, John F

    2012-06-01

    We characterize here a new nationwide incident cohort of multiple sclerosis from the US military-veteran population. This cohort provides an update to the only other US nationwide incidence study of multiple sclerosis performed during the 1970s. Medical records and data from the Department of Defense and Department of Veterans Affairs for cases of multiple sclerosis who served in the military between 1990, the start of the Gulf War era, and 2007 and who were service-connected for this disorder by the Department of Veterans Affairs from 1990 on, were reviewed. A total of 2691 patients were confirmed as having multiple sclerosis: 2288 definite, 190 possible, 207 clinically isolated syndrome and six neuromyelitis optica. Overall racial categories were White, Black and other, which included all Hispanics. There were 1278 White males and 556 females; 360 Black males and 296 females; and 200 others, 153 (77%) of whom were Hispanic. Mean age at onset of 30.7 years did not differ significantly by race or sex. Age at onset was 17-50 years in 99%, the same age range as 99% of the military. Average annual age specific (age 17-50 years) incidence rates per 100 000 for the entire series were 9.6 with 95% confidence interval of 9.3-10.0. Rates for Blacks were highest at 12.1 with confidence interval 11.2-13.1, Whites were 9.3 (interval 8.9-9.8) and others 6.9 (interval 6.0-7.9). For 83 Hispanics defined for 2000-07, the rate was 8.2 (interval 6.5-10.1). Much smaller numbers gave rates of 3.3 for Asian/Pacific Islanders and 3.1 for native Americans. Rates by sex for Whites were 7.3 and 25.8 male and female, respectively, for Blacks 8.4 and 26.3, and for Hispanics 6.6 and 17.0. Rates by service were high for Air Force (10.9) and Army (10.6), medium for Navy (9.1) and Coast Guard (7.9), and low for Marines (5.3). Relative risk of multiple sclerosis was 3.39 female:male and 1.27 Black:White. These new findings indicate that females of all races now have incidence rates for multiple

  18. Effect of Age, Sex, and Race Distance on Front Crawl Stroke Parameters in Subelite Adolescent Swimmers During Competition.

    PubMed

    Dormehl, Shilo J; Osborough, Conor D

    2015-08-01

    The aims of this study were to determine the effect of age, sex and race distance on velocity (v), stroke rate (SR), stroke length (SL) and stroke index (SI) of subelite adolescent swimmers in competition, and to investigate their pacing strategies during the 100-m and 200-m events. Video footage of 112 adolescent swimmers (56 female; 56 male), competing in the 100-m and 200-m freestyle events, in two age groups (12-14; 15-18 years) was recorded and subsequently analyzed. A MANOVA showed that all stroke parameters significantly differed between sexes and between race distances. The older adolescents had a higher v, a longer SL and a greater SI (p < .01) than the younger adolescents. There were significant interaction effects between age and sex for v, SL and SI. Most adolescents had a SL that was within 7% of that reported for 1992 Olympians, but had up to 16% lower SRs. Separate Friedman's ANOVAs showed that SL differed between successive race quarters for both age groups, both sexes and both race distances. It is likely that physical immaturity, inexperience in competition pacing and within-race fatigue strongly influence the performances of subelite adolescent front crawl swimmers. PMID:25902554

  19. Haematology and blood chemistry of Cebus apella in relation to sex and age.

    PubMed

    Riviello, M C; Wirz, A

    2001-12-01

    An effective health care program entails the prevention, diagnosis and treatment of medical problems. A knowledge of baseline values in clinically normal individuals is essential for determining the limits between good health and disease and for understanding the changes produced by pathogenic agents. However, very little information is currently available concerning the blood chemistry and haematological values of different species of monkeys, particularly new-world primates. The values of some haematological and chemical parameters in Cebus apella were determined. The aim of the present work was to verify the effect of age and sex on normal blood values. Blood samples were collected once a year for two successive years from 36 monkeys living in large captive social groups. Significant differences between males and females were found for AST, GGT, urea nitrogen and creatinine, erythrocytes, haemoglobin and haematocrit. Significant differences between juveniles and adults were found for calcium, AST, alkaline phosphatase, inorganic phosphorus, glucose, neutrophils, lymphocytes and serum protein parameters. PMID:11990530

  20. The epidemiology of HIV and syphilis among male commercial sex workers in northern Thailand.

    PubMed

    Kunawararak, P; Beyrer, C; Natpratan, C; Feng, W; Celentano, D D; de Boer, M; Nelson, K E; Khamboonruang, C

    1995-05-01

    The first confirmed case of human immunodeficiency virus (HIV) infection in Thailand was that of a Thai male commercial sex worker (CSW) in 1985. Since that time, this disease has manifested itself among injecting drug users, female sex workers, and in the general heterosexual and homosexual population. This paper reports the findings of a 5-year Thai study in which 1172 male CSWs were studied at least once. The purpose of the study was to identify the prevalence, incidence, and risk behaviors of CSWs regarding HIV and syphilis. The HIV prevalence increased from 1.4% in 1989 to 20.1% by 1993. Overall, the HIV prevalence for the 5-year period was statistically significant at 16.6%. Syphilis for this same period was 7.6% HIV infections were confirmed using enzyme-linked immunosorbent assay (ELISA). Multivariate analysis was calculated using multiple logistic regression. All CSWs in this study were provided with HIV pre-test counseling, were subjected to HIV and syphilis serology, were given condoms, and were provided with a referral for post-test counseling. Of the 1172 men seen, 219 (18.6%) were seen more than once. 27 cases of HIV infection were confirmed in the latter group (12.3%). Heterosexual men were found to be at lower risk of contracting an HIV infection than homosexual men. PMID:7639978

  1. Gentamicin Induced Nephrotoxicity: The Role of Sex Hormones in Gonadectomized Male and Female Rats

    PubMed Central

    Eshraghi-Jazi, Fatemeh; Talebi, Ardeshir; Moslemi, Fatemeh

    2016-01-01

    Background. Gentamicin (GM) induced nephrotoxicity may be sex hormones related. The effects of sex hormones on GM induced nephrotoxicity in gonadectomized rats were investigated. Methods. Ovariectomized rats received 0.25, 0.5, or 1 mg/kg/week of estradiol (ES) alone or accompanied with 10 mg/kg/week of progesterone (Pro) for two weeks followed by GM (100 mg/kg/day) for 9 days. Castrated rats were also treated with 10, 50, or 100 mg/kg/week of testosterone (TS) for two weeks and then received GM. In addition, a single castrated group received 0.25 mg/kg/week of ES plus GM. Results. GM increased the serum levels of blood urea nitrogen (BUN) and creatinine (Cr) and kidney tissue damage score (KTDS) (P < 0.05). TS had no effect on the serum levels of BUN and Cr and KTDS, while low dose of ES intensified these parameters in male (P < 0.05). ES (0.5 mg/kg) without Pro ameliorated KTDS in female (P < 0.05) while ES (1 mg/kg) with or without Pro exacerbated the BUN values and Cr values, KTDS, and body weight loss (P < 0.05). Conclusion. ES (0.5 mg/kg) without Pro ameliorated kidney damage induced by GM in female while neither TS nor ES had beneficial effect on nephrotoxicity induced by GM in male, although ES aggravated it. PMID:27213082

  2. Associations between sex, body weight, age, and ultrasonographically determined adrenal gland thickness in dogs with non-adrenal gland illness.

    PubMed

    Bento, Pedro L; Center, Sharon A; Randolph, John F; Yeager, Amy E; Bicalho, Rodrigo C

    2016-03-15

    OBJECTIVE To determine whether body weight, age, or sex was associated with ultrasonographically determined adrenal gland thickness (AT) in dogs with non-adrenal gland illness. DESIGN Retrospective cross-sectional study. ANIMALS 266 dogs (22 sexually intact and 119 castrated males and 19 sexually intact and 106 spayed females representing 12 breeds) with non-adrenal gland illness. PROCEDURES Thickness of the caudal pole of the left and right adrenal glands was measured on longitudinal ultrasonographic images. Dogs were stratified into age and body weight categories to investigate associations with AT. RESULTS AT was significantly lower in dogs that weighed ≤ 12 kg (26.4 lb) than in dogs that weighed > 12 kg and left AT increased with age. Both left and right AT were larger in male than in female dogs that weighed > 12 to ≤ 20 kg, and left AT was larger in male than in female dogs that weighed > 20 to ≤ 30 kg. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that body weight, age, and sex were significantly associated with AT, indicating that these variables should be considered when evaluating AT in dogs with non-adrenal gland illness and when developing reference intervals for AT in dogs. Further, findings indicated that dogs with non-adrenal gland illness that weigh ≤ 12 kg should have an AT no greater than 0.62 cm, whereas dogs that weigh > 12 kg should have an AT no greater than 0.72 cm. PMID:26953919

  3. HIV prevalence and risk behaviors among male clients of female sex workers in Yunnan, China

    PubMed Central

    Jin, Xia; Smith, Kumi; Chen, Ray Y.; Ding, Guowei; Yao, Yan; Wang, Haibo; Qian, Han-Zhu; Chang, Dongfang; Wang, Guixiang; Wang, Ning

    2009-01-01

    Objectives To assess the prevalence and risk factors of HIV among male clients of female sex workers in China. Methods Convenience sampling methods were used to recruit 315 clients using FSW-client and client-client networks. Subjects provided information on socio-demographic characteristics and sexual and drug behavior patterns. Blood samples were collected for HIV testing and urine samples for opiate testing. Results Overall HIV prevalence was 6.0%; among drug users it was 30.8%. 33.7% of respondents reported that they always use condoms in commercial sex and 63.5% that they used a condom in the last commercial sex episode. Drug use (OR: 6.1; 95% CI: 1.7–21.4) and lack of a regular sexual partner (OR: 6.3; 95% CI: 1.8–21.9) were significantly associated with HIV infection. Conclusions Clients of FSWs serve as potential bridges for HIV transmission from the high-risk FSWs to the low-risk general population, making them a key target for intervention. High HIV prevalence rates among clients in Kaiyuan is particularly alarming given their risk behavior patterns including high rates of partner exchange, low condom use rates, and drug using behaviors. Innovative interventions are needed to reduce the risk of HIV among clients and reduce the bridge of transmission to the general population. PMID:19730110

  4. Evaluation of Age, Sex, and Race Bias in the Personality Inventory for Children (PIC).

    ERIC Educational Resources Information Center

    Kline, Rex B.; Lachar, David

    1992-01-01

    Whether the external validity of the Personality Inventory for Children (PIC) was moderated by age, sex, or race was studied using 1,333 children and adolescents referred for mental health services. Race and sex generally did not moderate the relation of PIC scales to symptom checklists. Some relationships were age modified. (SLD)

  5. Age Group and Sex of Students. Fall 1974. Report No. 8-75.

    ERIC Educational Resources Information Center

    State Univ. of New York, Albany. Central Staff Office of Institutional Research.

    There has been considerable discussion in the literature of higher education regarding significant changes in student body characteristics. The data in this document examines distribution of students at the State University of New York system by age group and sex. Tables array four fundamental student characteristics: age, sex, level…

  6. Surprising Lack of Sex Differences in Normal Cognitive Aging in Twins

    ERIC Educational Resources Information Center

    Finkel, Deborah; Reynolds, Chandra A.; Berg, Stig; Pedersen, Nancy L.

    2006-01-01

    Sex differences in the etiology of normal cognitive functioning in aging remain largely unexplored. We conducted an investigation of genetic and environmental contributions to sex differences in level of cognitive performance and rate of decline in the Swedish Adoption/Twin Study of Aging (SATSA) (Finkel & Pedersen, 2004) data set. Behavioral…

  7. Physical Attractiveness, Age, and Sex as Determinants of Reactions to Resumes.

    ERIC Educational Resources Information Center

    Quereshi, M. Y.; Kay, Janet P.

    1986-01-01

    Physical attractiveness, age, and sex were manipulated to determine their effect on the evaluation of 54 hypothetical applicants' resumes for three different jobs by 60 Master's in Business Administration students. Physical attractiveness favorably influenced the suitability ratings for all jobs; raters' sex and age were not significant but…

  8. Methods of Suicide by Age: Sex and Race Differences among the Young and Old.

    ERIC Educational Resources Information Center

    McIntosh, John L.; Santos, John F.

    1986-01-01

    Annual official statistics for specific methods of suicide (firearms, hanging, poisons) by age for different sex and racial groups (Whites, Blacks, non-Whites excluding Black) were examined from 1960 to 1978. Comparisons among the age-sex-race groups, along with trends over time and differences in the methods employed, were noted. (Author/ABL)

  9. The balancing act: exploring stigma, economic need and disclosure among male sex workers in Ho Chi Minh City, Vietnam.

    PubMed

    Closson, Elizabeth F; Colby, Donn J; Nguyen, Thi; Cohen, Samuel S; Biello, Katie; Mimiaga, Matthew J

    2015-01-01

    In Vietnam, there is an emerging HIV epidemic among men who have sex with men (MSM). Male sex workers engage in high-risk sexual behaviours that make them particularly vulnerable to HIV infection. In 2010, 23 MSM in Ho Chi Minh City (HCMC) who recently received payment for sex with another man completed in-depth qualitative interviews exploring motivations for sex work, patterns of sex work disclosure and experiences of social stigma. Interviews were recorded, transcribed and translated into English and analysed using a qualitative descriptive approach. Low wages, unstable employment and family remittances were motivating factors for MSM in HCMC to sell sex. Participants described experiences of enacted and felt social stigma related to their involvement in sex work. In response, they utilised stigma management techniques aimed at concealment of involvement in sex work. Such strategies restricted sexual communication with non-paying sex partners and potentially limited their ability to seek social support from family and friends. Departing from decontextualized depictions of sex work disclosure, our findings describe how decisions to reveal involvement in sex work are shaped by social and structural factors such as social stigma, techniques to minimise exposure to stigma, economic imperatives and familial responsibilities. PMID:25555192

  10. The balancing act: Exploring stigma, economic need and disclosure among male sex workers in Ho Chi Minh City, Vietnam

    PubMed Central

    Closson, Elizabeth F.; Colby, Donn J.; Nguyen, Thi; Cohen, Samuel S.; Biello, Katie; Mimiaga, Matthew J.

    2014-01-01

    In Vietnam, there is an emerging HIV epidemic among men who have sex with men (MSM). Male sex workers (MSWs) engage in high-risk sexual behaviours that make them particularly vulnerable to HIV infection. In 2010, 23 MSM in Ho Chi Minh City (HCMC) who recently received payment for sex with another man completed in-depth qualitative interviews exploring motivations for sex work, patterns of sex work disclosure and experiences of social stigma. Interviews were recorded, transcribed and translated into English and analysed using a qualitative descriptive approach. Low wages, unstable employment, and family remittances were motivating factors for MSM in HCMC to sell sex. Participants described experiences of enacted and felt social stigma related to their involvement in sex work. In response, they utilized stigma management techniques aimed at concealment of involvement in sex work. Such strategies restricted sexual communication with non-paying sex partners and potentially limited their ability to seek social support from family and friends. Departing from decontextualized depictions of sex work disclosure, our findings describe how decisions to reveal involvement in sex work are shaped by social and structural factors such as social stigma, techniques to minimize exposure to stigma, economic imperatives and familial responsibilities. PMID:25555192

  11. Low Serum Albumin Level, Male Sex, and Total Gastrectomy Are Risk Factors of Severe Postoperative Complications in Elderly Gastric Cancer Patients

    PubMed Central

    Kang, Sung Chan; Kim, Hyun Il

    2016-01-01

    Purpose It is well known that old age is a risk factor for postoperative complications. Therefore, this study aimed to explore the risk factors for poor postoperative surgical outcomes in elderly gastric cancer patients. Materials and Methods Between January 2006 and December 2015, 247 elderly gastric cancer patients who underwent curative gastrectomy were reviewed. In this study, an elderly patient was defined as a patient aged ≥65 years. All possible variables were used to explore the risk factors for poor early surgical outcomes in elderly gastric cancer patients. Results Based on multivariate analyses of preoperative risk factors, preoperative low serum albumin level (<3.5 g/dl) and male sex showed statistical significance in predicting severe postoperative complications. Additionally, in an analysis of surgery-related risk factors, total gastrectomy was a risk factor for severe postoperative complications. Conclusions Our study findings suggest that low serum albumin level, male sex, and total gastrectomy could be risk factors of severe postoperative complications in elderly gastric cancer patients. Therefore, surgeons should work carefully in cases of elderly gastric cancer patients with low preoperative serum albumin level and male sex. We believe that efforts should be made to avoid total gastrectomy in elderly gastric cancer patients. PMID:27104026

  12. Study of the effect of age changes on lip print pattern and its reliability in sex determination.

    PubMed

    Randhawa, K; Narang, R S; Arora, P C

    2011-12-01

    Cheiloscopy, a forensic investigation technique, deals with the study of elevations and depressions which form a characteristic pattern on the external surface of the lips. The objective of the study was to determine the most common lip patterns in North Indian population, to evaluate whether sex determination is possible on the basis of lip prints and to ascertain if there is any co-relation between advancing age and its effect on lip pattern. A total of 600 subjects, 289 males and 311 females were selected and divided into three age groups (group 1: 1-20 years, group 2: 21-40 years, group 3: 40 years and above). Statistical analysis (applying Chi square test) showed very highly significant difference for different lip patterns (p < 0.0001) in males and females in group 2 and no significant difference in group 1 and group 3. The most predominant pattern in the entire study population was Type I (32.33%). Age changes like immaturity of lips in younger age and diminished anatomic details and tonicity in older age can have a considerable effect on the lip pattern, thereby making the correct identification of sex in these age groups debatable. PMID:22717913

  13. Effects of age, sex, and genotype on high-sensitivity metabolomic profiles in the fruit fly, Drosophila melanogaster

    PubMed Central

    Hoffman, Jessica M; Soltow, Quinlyn A; Li, Shuzhao; Sidik, Alfire; Jones, Dean P; Promislow, Daniel E L

    2014-01-01

    Researchers have used whole-genome sequencing and gene expression profiling to identify genes associated with age, in the hope of understanding the underlying mechanisms of senescence. But there is a substantial gap from variation in gene sequences and expression levels to variation in age or life expectancy. In an attempt to bridge this gap, here we describe the effects of age, sex, genotype, and their interactions on high-sensitivity metabolomic profiles in the fruit fly, Drosophila melanogaster. Among the 6800 features analyzed, we found that over one-quarter of all metabolites were significantly associated with age, sex, genotype, or their interactions, and multivariate analysis shows that individual metabolomic profiles are highly predictive of these traits. Using a metabolomic equivalent of gene set enrichment analysis, we identified numerous metabolic pathways that were enriched among metabolites associated with age, sex, and genotype, including pathways involving sugar and glycerophospholipid metabolism, neurotransmitters, amino acids, and the carnitine shuttle. Our results suggest that high-sensitivity metabolomic studies have excellent potential not only to reveal mechanisms that lead to senescence, but also to help us understand differences in patterns of aging among genotypes and between males and females. PMID:24636523

  14. Lead-induced modifications of immune responses in aging male and female mice

    SciTech Connect

    Genova, T.F.

    1982-01-01

    This study was designed to analyze the effects of lead intoxication on the immunological responses of aging male and female Balb/c mice. Both males and females on the lead diet exhibited a loss of weight after one week of treatment. The animals began to gain weight again after eight or fifteen weeks for males and females respectively. Although both groups continued to gain weight at a rate consistent with control animals, they never reached the same weights as their same-sex control counterparts. Immunofluorescent staining indicated the presence of greater renal pathology in lead-fed animals as compared to controls. Lead-fed males demonstrated the greatest pathology of any group. Both T and B cell mitogenic responses declined during the early phases of the experiment. This was followed, at age 25-27 weeks, by an increase in activity to levels greater than those of control animals. The depression and subsequent increase in mitogenic responses was mirrored in the ability of T cells to regulate B cell plaque formation when stimulated with sheep red blood cells. T cell function returned to control levels in coincidence with the increase in T and B cell mitogenicity. The return of T cell functionality to control levels coincides with the increased mitogenesis noted in T and B cell populations and the onset of weight gains by lead-fed animals. This coincidence suggests the occurrence of a physiological or immunological change which is compensating for the continued lead intoxication. One such change may be a lead induced reduction in the number or function of a T cell subset, eg. T suppressors.

  15. Annual changes in serum sex steroids in male and female black (Ursus americanus) and polar (Ursus maritimus) bears.

    PubMed

    Palmer, S S; Nelson, R A; Ramsay, M A; Stirling, I; Bahr, J M

    1988-06-01

    The adaptation of black and polar bears to their environments is proportional to the severity of climate and food restriction. Both black and polar bears mate during the spring, despite differences in their recent metabolic state. Reproductive activity in black bears follows 4 mo of torpor, whereas reproduction in polar bears occurs prior to torpor. The goals of this study were to measure the annual changes in serum sex steroids in male and female black and polar bears, and to determine if changes in serum levels of these steroids were associated with metabolic condition or photoperiod. Serum testosterone (T) concentrations were elevated during spring in black and polar bears. Moreover, this increase in serum T in polar bears during spring was correlated with age and testis size. Serum progesterone (P4) concentrations increased in pregnant polar bears in fall coincident with the time of expected implantation. No increases in serum P4 were observed in nonpregnant black and polar bears. Serum estradiol (E2) was elevated in nonpregnant and pregnant polar bears 2 mo prior to the time of expected implantation. We found that serum sex steroids measured in black and polar bears change independent of torpor. Therefore, our results suggest that photoperiod may be a more important regulator of serum steroid levels and reproduction than metabolic condition. PMID:3408772

  16. Male Sex is Associated with a Reduced Alveolar Epithelial Sodium Transport

    PubMed Central

    Kaltofen, Till; Haase, Melanie; Thome, Ulrich H.; Laube, Mandy

    2015-01-01

    Respiratory distress syndrome (RDS) is the most frequent pulmonary complication in preterm infants. RDS incidence differs between genders, which has been called the male disadvantage. Besides maturation of the surfactant system, Na+ transport driven alveolar fluid clearance is crucial for the prevention of RDS. Na+ transport is mediated by the epithelial Na+ channel (ENaC) and the Na,K-ATPase, therefore potential differences in their expression or activity possibly contribute to the gender imbalance observed in RDS. Fetal distal lung epithelial (FDLE) cells of rat fetuses were separated by sex and analyzed regarding expression and activity of the Na+ transporters. Ussing chamber experiments showed a higher baseline short-circuit current (ISC) and amiloride-sensitive ΔISC in FDLE cells of female origin. In addition, maximal amiloride-sensitive ΔISC and maximal ouabain-sensitive ΔISC of female cells were higher when measured in the presence of a permeabilized basolateral or apical membrane, respectively. The number of FDLE cells per fetus recoverable during cell isolation was also significantly higher in females. In addition, lung wet-to-dry weight ratio was lower in fetal and newborn female pups. Female derived FDLE cells had higher mRNA levels of the ENaC- and Na,K-ATPase subunits. Furthermore, estrogen (ER) and progesterone receptor (PR) mRNA levels were higher in female cells, which might render female cells more responsive, while concentrations of placenta-derived sex steroids do not differ between both genders during fetal life. Inhibition of ER-β abolished the sex differences in Na+ transport and female cells were more responsive to estradiol stimulation. In conclusion, a higher alveolar Na+ transport, possibly attributable to a higher expression of hormone receptors in female FDLE cells, provides an explanation for the well known sex-related difference in RDS occurrence and outcome. PMID:26291531

  17. In Search of Emerging Same-Sex Sexuality: Romantic Attractions at Age 13 Years.

    PubMed

    Li, Gu; Hines, Melissa

    2016-10-01

    Sex-typed behavior in childhood is significantly related to sexual orientation in adulthood. In addition, same-sex attractions in early adolescence are more non-exclusive than in adulthood and can differ from later same-sex orientations. However, little research has focused on romantic attractions as they emerge during early adolescence. Drawing a sample from the Avon Longitudinal Study of Parents and Children (197 girls, 204 boys), the current study examined whether same-sex romantic attractions at age 13 years were exclusive, and whether they were predicted by sex-typed behavior at age 3.5 years. No young adolescents in this sample reported exclusive same-sex attractions, and increased same-sex attractions were not significantly related to reduced other-sex sexualities. Childhood sex-typed behavior did not significantly predict early same-sex attractions, suggesting that early same-sex attractions differ from later same-sex orientations. The current study highlights the importance of studying the development of sexuality beginning prior to adulthood. PMID:27091185

  18. Prevalence and associated factors of condomless receptive anal intercourse with male clients among transgender women sex workers in Shenyang, China

    PubMed Central

    Cai, Yong; Wang, Zixin; Lau, Joseph TF; Li, Jinghua; Ma, Tiecheng; Liu, Yan

    2016-01-01

    Introduction Globally, transgender women sex workers have a high prevalence of HIV and condomless receptive anal intercourse with male clients (CRAIMC). We investigated the prevalence of CRAIMC and factors associated with CRAIMC among transgender women sex workers in China. Methods In 2014, we anonymously interviewed 220 transgender women sex workers face to face in Shenyang, China. Those who self-reported as HIV negative or as having unknown HIV serostatus were invited to take up free, anonymous HIV rapid testing (n=183); 90 did so. Using CRAIMC in the last month as the dependent variable, three types of associated factors were investigated, in addition to background factors: feminizing medical interventions, sex work and perceptions related to condom use. Univariate and multiple logistic regression models were fitted. Results Of the participants, 16.8% self-reported as HIV positive and 9.1% were detected to be HIV positive through free HIV testing; 26.8% had had CRAIMC in the last month, 45.5% had performed sex work in other Chinese cities (last year), and 23.2% had had condomless anal intercourse with men who were non-clients. In the adjusted analysis, significant factors associated with CRAIMC (last month) included the following: 1) any feminizing medical intervention performed (adjusted odds ratio, AOR: 2.22); 2) sex-work-related factors, including recruitment of male clients most often at hotels (AOR: 5.02) and charge per episode of transactional sex (201 to 400 RMB, AOR: 0.27; reference group: ≤100 RMB); and 3) perceptions related to condom use, including perceived transgender identity's impact on condomless sex such as wearing feminine attire, concern about exposing their status as a transgender woman to male clients (AOR: 1.20) and perceived self-efficacy of consistent condom use with male clients (AOR: 0.56). Perceived self-efficacy of consistent condom use with male clients fully mediated the association between perceived transgender identity's impact

  19. Middle-age male mice have increased severity of experimental autoimmune encephalomyelitis and are unresponsive to testosterone therapy.

    PubMed

    Matejuk, Agata; Hopke, Corwyn; Vandenbark, Arthur A; Hurn, Patricia D; Offner, Halina

    2005-02-15

    Treatment with sex hormones is known to protect against experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, little is known about how age affects the course of EAE or response to hormone treatment. This study demonstrates striking differences between middle-age vs young C57BL/6 male mice in the clinical course of EAE and response to both testosterone (T4) and estrogen (E2) hormone therapy. Unlike young males that developed an acute phase of EAE followed by a partial remission, middle-age males suffered severe chronic and unremitting EAE that was likely influenced by alterations in the distribution and function of splenic immunocytes and a significant reduction in suppressive activity of CD4+CD25+ regulatory T cells in the spleen and spinal cord. Middle-age males had reduced numbers of splenic CD4+ T cells that were generally hypoproliferative, but enhanced numbers of splenic macrophages and MHC class II-expressing cells, and increased secretion of the proinflammatory factors IFN-gamma and MCP-1. Surprisingly, middle-age males were unresponsive to the EAE-protective effects of T4 and had only a transient benefit from E2 treatment; young males were almost completely protected by both hormone treatments. T4 treatment of young males inhibited proliferation of myelin oligodendrocyte glycoprotein 35-55-specific T cells and secretion of TNF-alpha and IFN-gamma. The effects of T4 in vivo and in vitro were reversed by the androgen receptor antagonist, flutamide, indicating that the regulatory effects of T4 were mediated through the androgen receptor. These data are the first to define age-dependent differences in EAE expression and response to hormone therapy. PMID:15699175

  20. The usefulness of age and sex to predict all-cause mortality in patients with dilated cardiomyopathy: a single-center cohort study

    PubMed Central

    Li, Xiaoping; Cai, Chi; Luo, Rong; Jiang, Rongjian; Zeng, Jie; Tang, Yijia; Chen, Yang; Fu, Michael; He, Tao; Hua, Wei

    2015-01-01

    Objective Recent studies have shown that sex and age are associated with outcomes in patients with cardiomyopathy. The purpose of this study was to determine the all-cause mortality of dilated cardiomyopathy (DCM) by age and sex. Methods and results The patients were divided into non-elderly (age <60 years, n=811) and elderly (age ≥60 years, n=331) groups. No difference in the all-cause mortality rate was observed between elderly and non-elderly patients (27.2% vs 22.2%, log-rank χ2=2.604, P=0.107). Furthermore, no significant difference in mortality was observed between the male and female patients (23.3% vs 24.5%, log-rank χ2=0.707, P=0.400). However, subgroup analysis revealed that elderly male patients exhibited a higher mortality rate than non-elderly male patients (29.4% vs 21.3%, log-rank χ2=5.898, P=0.015), while no difference was observed between the elderly female patients and non-elderly female patients. In the Cox analysis, neither age nor sex was a significant independent predictor of all-cause mortality in patients with DCM. Conclusion In conclusion, no significant difference in mortality between male and female patients or between the elderly and non-elderly patients was observed. Only among males was a difference in mortality observed; elderly male patients experienced greater mortality than that of non-elderly male patients. No effect of age or sex on all-cause mortality was observed in patients with DCM. PMID:26396507

  1. Baseline sacroiliac joint magnetic resonance imaging abnormalities and male sex predict the development of radiographic sacroiliitis.

    PubMed

    Akar, Servet; Isik, Sibel; Birlik, Bilge; Solmaz, Dilek; Sari, Ismail; Onen, Fatos; Akkoc, Nurullah

    2013-10-01

    We evaluated the relationship between the baseline sacroiliac joint (SIJ) magnetic resonance imaging (MRI) findings and the development of radiographic sacroiliitis and tested their prognostic significance in cases of ankylosing spondylitis. Patients who had undergone an SIJ MRI at the rheumatology department were identified. Individuals for whom pelvic X-rays were available after at least 1 year of MRI were included in the analysis. All radiographs and MRI examinations were scored by two independent readers. Medical records of the patients were reviewed to obtain potentially relevant demographic and clinical data. We identified 1,069 SIJ MRIs, and 328 fulfilled our inclusion criteria. Reliability analysis revealed moderate to good inter- and intra-observer agreement. On presentation data, 14 cases were excluded because they had unequivocal radiographic sacroiliitis at baseline. After a mean of 34.8 months of follow-up, 24 patients developed radiographic sacroiliitis. The presence of active sacroiliitis (odds ratio (OR) 15.1) and structural lesions on MRI (OR 8.3), male sex (OR 4.7), fulfillment of Calin's inflammatory back pain criteria (P = 0.001), and total MRI activity score (P < 0.001) were found to be related to the development of radiographic sacroiliitis. By regression modeling, the presence of bot