Meiotic recombination counteracts male-biased mutation (male-driven evolution).

PubMed

Mawaribuchi, Shuuji; Ito, Michihiko; Ogata, Mitsuaki; Oota, Hiroki; Katsumura, Takafumi; Takamatsu, Nobuhiko; Miura, Ikuo

2016-01-27

Meiotic recombination is believed to produce greater genetic variation despite the fact that deoxyribonucleic acid (DNA)-replication errors are a major source of mutations. In some vertebrates, mutation rates are higher in males than in females, which developed the theory of male-driven evolution (male-biased mutation). However, there is little molecular evidence regarding the relationships between meiotic recombination and male-biased mutation. Here we tested the theory using the frog Rana rugosa, which has both XX/XY- and ZZ/ZW-type sex-determining systems within the species. The male-to-female mutation-rate ratio (α) was calculated from homologous sequences on the X/Y or Z/W sex chromosomes, which supported male-driven evolution. Surprisingly, each α value was notably higher in the XX/XY-type group than in the ZZ/ZW-type group, although α should have similar values within a species. Interestingly, meiotic recombination between homologous chromosomes did not occur except at terminal regions in males of this species. Then, by subdividing α into two new factors, a replication-based male-to-female mutation-rate ratio (β) and a meiotic recombination-based XX-to-XY/ZZ-to-ZW mutation-rate ratio (γ), we constructed a formula describing the relationship among a nucleotide-substitution rate and the two factors, β and γ. Intriguingly, the β- and γ-values were larger and smaller than 1, respectively, indicating that meiotic recombination might reduce male-biased mutations. © 2016 The Author(s).

Male sexuality.

PubMed

Ginsberg, Terrie B

2010-05-01

It should be recognized that sexuality in the aging male is of such import that a complete sexual history must be performed. By taking a complete sexual history, facts can be obtained that will allow for appropriate focus relating to a holistic evaluation and will enable us to dispel antiquated sexual myths pertaining to the aging male. If initiated by the history taker, questions concerning sexuality may be discussed more comfortably by the patient. Erectile dysfunction, male sexual response cycle, testosterone, sexually transmitted diseases, human immunodeficiency virus, long-term illness, along with religion and culture are explored in this article with the aim of improving one's knowledge base, self reflection, and awareness of the importance of male sexuality. A complete understanding and appreciation of the aging male's medical history, surgical history, social history, and emotional history as well as his sexual, cultural, and religious concepts will allow the health care provider to better analyze information, and to recommend and provide appropriate advice and treatment to the aging male patient. Copyright 2010 Elsevier Inc. All rights reserved.

Responses of female rock lizards to multiple scent marks of males: effects of male age, male density and scent over-marking.

PubMed

Martín, José; López, Pilar

2013-03-01

Scent-marked substrates may inform conspecifics on the characteristics of territorial males. Scent-marks of male Carpetan rock lizards (Iberolacerta cyreni) affect space use of females, which by selecting an area may increase the probability of mating with the male that has scent-marked that area. However, males do not hold exclusive territories, and scent-marks of different individual males are often together. This may provide complex information from multiple sources on the social structure. Here, we examined female preference in response to scent marks of various males and combinations in a laboratory experiment. Females preferred areas scent-marked by territorial old males against those scent-marked by young satellite-sneaker males. This reflected the known preference of females for mating with old males. In a second experiment, females preferred areas scent-marked by two males to areas of similar size marked by a single male. This may increase the probability of obtaining multiple copulations with different males, which may favour sperm competition and cryptic female choice, or may be a way to avoid infertile males. Finally, when we experimentally over-marked the scent-marks of an old male with scent-marks of a young male, females did not avoid, nor prefer, the over-marked area, suggesting that the quality of the old male may override the presence of a satellite male. We suggest that, irrespective of the causes underlying why a female selects a scent-marked area, this strategy may affect her reproductive success, which may have the same evolutionary consequences that "direct" mate choice decisions of other animals. Copyright © 2013 Elsevier B.V. All rights reserved.

Graduating Black Males

ERIC Educational Resources Information Center

Bell, Edward Earl

2010-01-01

Background: The graduation numbers for Black males are dismal, chilling, and undeniably pathetic. The nation graduates only 47% of Black males who enter the 9th grade. The infusion of federal dollars and philanthropic support will not stop the trajectory of Black males who drop out of school. Black males face an upheaval educational battle;…

Assortative sexual mixing patterns in male-female and male-male partnerships in Melbourne, Australia: implications for HIV and sexually transmissible infection transmission.

PubMed

Chow, Eric P F; Read, Tim R H; Law, Matthew G; Chen, Marcus Y; Bradshaw, Catriona S; Fairley, Christopher K

2016-10-01

Assortative mixing patterns have become a new and important focus in HIV/sexually transmissible infection (STI) research in recent years. There are very limited data on sexual mixing patterns, particularly in an Australian population. Male-female and male-male partnerships attending the Melbourne Sexual Health Centre (MSHC) between 2011 and 2014 were included. Correlation of age between two individuals within a partnership was examined by using Spearman's rank correlation. The Newman's assortativity coefficient was used as an aggregate quantitative measurement of sexual mixing for number of partners and condom use. 1165 male-female and 610 male-male partnerships were included in the analysis. There was a strong positive correlation of age in both male-female (rho=0.709; P<0.001) and male-male partnerships (rho=0.553; P<0.001). The assortative mixing pattern for number of partners was similar in male-female (r=0.255; 95% CI: 0.221-0.289) and male-male partnerships (r=0.264; 95% CI: 0.218-0.309). There was a stronger assortative mixing pattern for condom use in male-male (r=0.517, 95% CI: 0.465-0.569) compared with male-female (r=0.382; 95% CI: 0.353-0.412) partnerships. Male-female and male-male partnerships have a high assortativity mixing pattern for age, number of partners and condom use. The sexual mixing pattern is not purely assortative, and hence it may lead to increased HIV and STI transmission in certain risk groups.

Visual perceptions of male obesity: a cross-cultural study examining male and female lay perceptions of obesity in Caucasian males.

PubMed

Robinson, Eric; Hogenkamp, Pleunie S

2015-05-16

Obesity is now common and this may have altered visual perceptions of what constitutes a 'normal' and therefore healthy weight. The present study examined cross-cultural differences in male and female participants' ability to visually identify the weight status of photographed Caucasian males. Five hundred and fifty three male and female young adults from the US (high obesity prevalence), UK and Sweden (lower obesity prevalence) participated in an online study. Participants judged the weight status of a series of photographed healthy weight, overweight and obese (class I) Caucasian males and rated the extent to which they believed each male should consider losing weight. There was a strong tendency for both male and female participants to underestimate the weight status of the photographed overweight and obese males. Photographed males were frequently perceived as being of healthier weight than they actually were. Some modest cross-cultural differences were also observed; US participants were worse at recognising obesity than UK participants (p < 0.05) and were also significantly more likely to believe that the photographed obese males did not need to consider losing weight, in comparison to both the UK and Swedish participants (ps < 0.05). No cross-cultural differences were observed for perceptions or attitudes towards the photographed healthy weight or overweight males. The weight status of overweight and obese (class I) Caucasian males is underestimated when judged by males and females using visual information alone. This study provides initial evidence of modest cross-cultural differences in attitudes toward, and the ability to recognise, obesity in Caucasian males.

Mutation of Drosophila dopamine receptor DopR leads to male-male courtship behavior.

PubMed

Chen, Bin; Liu, He; Ren, Jing; Guo, Aike

2012-07-06

In Drosophila, dopamine plays important roles in many biological processes as a neuromodulator. Previous studies showed that dopamine level could affect fly courtship behaviors. Disturbed dopamine level leads to abnormal courtship behavior in two different ways. Dopamine up-regulation induces male-male courtship behavior, while down-regulation of dopamine level results in increased sexual attractiveness of males towards other male flies. Until now, the identity of the dopamine receptor involved in this abnormal male-male courtship behavior remains unknown. Here we used genetic approaches to investigate the role of dopamine receptors in fly courtship behavior. We found that a dopamine D1-like receptor, DopR, was involved in fly courtship behavior. DopR mutant male flies display male-male courtship behavior. This behavior is mainly due to the male's increased propensity to court other males. Expression of functional DopR successfully rescued this mutant phenotype. Knock-down of D2-like receptor D2R and another D1-like receptor, DAMB, did not induce male-male courtship behavior, indicating the receptor-type specificity of this phenomenon. Our findings provide insight into a possible link between dopamine level disturbance and the induced male-male courtship behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

Male-Male Clasping May Be Part of an Alternative Reproductive Tactic in Xenopus laevis

PubMed Central

Rhodes, Heather J.; Stevenson, Rachel J.; Ego, Courtney L.

2014-01-01

Male Xenopus laevis frogs have been observed to clasp other males in a sustained, amplectant position, the purpose of which is unknown. We examined three possible hypotheses for this counter-intuitive behavior: 1) clasping males fail to discriminate the sex of the frogs they clasp; 2) male-male clasping is an aggressive or dominant behavior; or 3) that males clasp other males to gain proximity to breeding events and possibly engage in sperm competition. Our data, gathered through a series of behavioral experiments in the laboratory, refute the first two hypotheses. We found that males did not clasp indiscriminately, but showed a sex preference, with most males preferentially clasping a female, but a proportion preferentially clasping another male. Males that clasped another male when there was no female present were less likely to “win” reproductive access in a male-male-female triad, indicating that they did not establish dominance through clasping. However, those males did gain proximity to oviposition by continued male-male clasping in the presence of the female. Thus, our findings are consistent with, but cannot confirm, the third hypothesis of male-male clasping as an alternative reproductive tactic. PMID:24849114

Coevolution of female ovulatory signals and male-male competition in primates.

PubMed

Nakahashi, Wataru

2016-03-07

Visual signals of ovulation vary among primate species. Although slight ovulatory signals are considered primate ancestral traits of which some species still exhibit, some show prominent swelling of their perineal skin (exaggerated sexual swellings) and others do not exhibit any signals of ovulation (concealed ovulation). These signals strongly affect male mating behaviors. I develop an evolutionary model of female ovulatory signals and male-male competition. I assume that each male allocates his effort between attraction of females and male-male competition for dominance. Each female gains a benefit if she is fertile and free from the alpha male who always guards one of the most fertile females in the group, but suffers a cost if she expresses a different ovulatory signal from an ancestral trait. I show that various types of ovulatory signals may evolve and can be multistable. Male-male competition becomes intense when the signal honestly indicates ovulation. Ovulatory signals may evolve to be less exaggerated in unimale groups than in multimale groups and monogamy is more likely to evolve when ovulation is concealed. These results may partly explain why various types of primate ovulatory signals evolved and how they have affected primate societies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hybrid male sterility and genome-wide misexpression of male reproductive proteases.

PubMed

Gomes, Suzanne; Civetta, Alberto

2015-07-06

Hybrid male sterility is a common barrier to gene flow between species. Previous studies have posited a link between misregulation of spermatogenesis genes in interspecies hybrids and sterility. However, in the absence of fully fertile control hybrids, it is impossible to differentiate between misregulation associated with sterility vs. fast male gene regulatory evolution. Here, we differentiate between these two possibilities using a D. pseudoobscura species pair that experiences unidirectional hybrid sterility. We identify genes uniquely misexpressed in sterile hybrid male reproductive tracts via RNA-seq. The sterile male hybrids had more misregulated and more over or under expressed genes relative to parental species than the fertile male hybrids. Proteases were the only gene ontology class overrepresented among uniquely misexpressed genes, with four located within a previously identified hybrid male sterility locus. This result highlights the potential role of a previously unexplored class of genes in interspecific hybrid male sterility and speciation.

Male Contraception

PubMed Central

Amory, John K.

2016-01-01

NARRATIVE ABSTRACT Although female contraceptives are very effective at preventing unintended pregnancy, some women cannot use them due to health conditions or side effects, leaving some couples without effective contraceptive options. In addition, many men wish to take active responsibility for family planning. Thus, there is a great need for male contraceptives to prevent unintended pregnancy, of which 80–90 million occur annually. At present, effective male contraceptive options are condoms and vasectomy, which are not ideal for all men. Therefore, efforts are under way to develop novel male contraceptives. This paper will briefly review the advantages and disadvantages of condoms and vasectomies, and then discuss the research directed towards the development of novel methods of male contraception. PMID:27678037

Hybrid male sterility and genome-wide misexpression of male reproductive proteases

PubMed Central

Gomes, Suzanne; Civetta, Alberto

2015-01-01

Hybrid male sterility is a common barrier to gene flow between species. Previous studies have posited a link between misregulation of spermatogenesis genes in interspecies hybrids and sterility. However, in the absence of fully fertile control hybrids, it is impossible to differentiate between misregulation associated with sterility vs. fast male gene regulatory evolution. Here, we differentiate between these two possibilities using a D. pseudoobscura species pair that experiences unidirectional hybrid sterility. We identify genes uniquely misexpressed in sterile hybrid male reproductive tracts via RNA-seq. The sterile male hybrids had more misregulated and more over or under expressed genes relative to parental species than the fertile male hybrids. Proteases were the only gene ontology class overrepresented among uniquely misexpressed genes, with four located within a previously identified hybrid male sterility locus. This result highlights the potential role of a previously unexplored class of genes in interspecific hybrid male sterility and speciation. PMID:26146165

Male tolerance and male–male bonds in a multilevel primate society

PubMed Central

Patzelt, Annika; Kopp, Gisela H.; Ndao, Ibrahima; Kalbitzer, Urs; Zinner, Dietmar

2014-01-01

Male relationships in most species of mammals generally are characterized by intense intrasexual competition, with little bonding among unrelated individuals. In contrast, human societies are characterized by high levels of cooperation and strong bonds among both related and unrelated males. The emergence of cooperative male–male relationships has been linked to the multilevel structure of traditional human societies. Based on an analysis of the patterns of spatial and social interaction in combination with genetic relatedness data of wild Guinea baboons (Papio papio), we show that this species exhibits a multilevel social organization in which males maintain strong bonds and are highly tolerant of each other. Several “units” of males with their associated females form “parties,” which team up as “gangs.” Several gangs of the same “community” use the same home range. Males formed strong bonds predominantly within parties; however, these bonds were not correlated with genetic relatedness. Agonistic interactions were relatively rare and were restricted to a few dyads. Although the social organization of Guinea baboons resembles that of hamadryas baboons, we found stronger male–male affiliation and more elaborate greeting rituals among male Guinea baboons and less aggression toward females. Thus, the social relationships of male Guinea baboons differ markedly from those of other members of the genus, adding valuable comparative data to test hypotheses regarding social evolution. We suggest that this species constitutes an intriguing model to study the predictors and fitness benefits of male bonds, thus contributing to a better understanding of the evolution of this important facet of human social behavior. PMID:25201960

Male contraception.

PubMed

Amory, John K

2016-11-01

Although female contraceptives are very effective at preventing unintended pregnancy, some women can not use them because of health conditions or side-effects, leaving some couples without effective contraceptive options. In addition, many men wish to take active responsibility for family planning. Thus, there is a great need for male contraceptives to prevent unintended pregnancies, of which 80-90 million occur annually. At present, effective male contraceptive options are condoms and vasectomy, which are not ideal for all men. Therefore, efforts are under way to develop novel male contraceptives. This paper briefly reviews the advantages and disadvantages of condoms and vasectomies and then discusses the research directed toward development of novel methods of male contraception. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Hierarchical chemosensory regulation of male-male social interactions in Drosophila

PubMed Central

Wang, Liming; Han, Xiaoqing; Mehren, Jennifer; Hiroi, Makoto; Billeter, Jean-Christophe; Miyamoto, Tetsuya; Amrein, Hubert; Levine, Joel D.; Anderson, David J.

2011-01-01

Pheromones regulate male social behaviors in Drosophila, but the identities and behavioral role(s) of these chemosensory signals, and how they interact, are incompletely understood. Here we show that (Z)-7-tricosene (7-T), a male-enriched cuticular hydrocarbon (CH) previously shown to inhibit male-male courtship, is also essential for normal levels of aggression. The opposite influences of 7-T on aggression and courtship are independent, but both require the gustatory receptor Gr32a. Surprisingly, sensitivity to 7-T is required for the aggression-promoting effect of 11-cis-vaccenyl acetate (cVA), an olfactory pheromone, but 7-T sensitivity is independent of cVA. 7-T and cVA therefore regulate aggression in a hierarchical manner. Furthermore, the increased courtship caused by depletion of male CHs is suppressed by a mutation in the olfactory receptor Or47b. Thus, male social behaviors are controlled by gustatory pheromones that promote and suppress aggression and courtship, respectively, and whose influences are dominant to olfactory pheromones that enhance these behaviors. PMID:21516101

Reduction of dopamine level enhances the attractiveness of male Drosophila to other males.

PubMed

Liu, Tong; Dartevelle, Laurence; Yuan, Chunyan; Wei, Hongping; Wang, Ying; Ferveur, Jean-François; Guo, Aike

2009-01-01

Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this behavior is mainly due to the increased male attractiveness or decreased aversiveness towards other males, but not to their enhanced propensity to court other males. Chemical signal input probably plays a crucial role in the male-male courtship induced by the courtees with reduction of dopamine. Our finding provides insight into the relationship between the dopamine reduction and male-male courtship behavior, and hints dopamine level is important for controlling Drosophila courtship behavior.

Reduction of Dopamine Level Enhances the Attractiveness of Male Drosophila to Other Males

PubMed Central

Liu, Tong; Dartevelle, Laurence; Yuan, Chunyan; Wei, Hongping; Wang, Ying; Ferveur, Jean-François; Guo, Aike

2009-01-01

Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this behavior is mainly due to the increased male attractiveness or decreased aversiveness towards other males, but not to their enhanced propensity to court other males. Chemical signal input probably plays a crucial role in the male-male courtship induced by the courtees with reduction of dopamine. Our finding provides insight into the relationship between the dopamine reduction and male-male courtship behavior, and hints dopamine level is important for controlling Drosophila courtship behavior. PMID:19238209

Androgen responses to reproductive competition of males pursuing either fixed or plastic alternative reproductive tactics.

PubMed

von Kuerthy, Corinna; Ros, Albert F H; Taborsky, Michael

2016-11-15

Alternative reproductive tactics (ARTs), which can be plastic or fixed for life, may be characterized by distinct hormonal profiles. The relative plasticity hypothesis predicts flexible androgen regulation for adult males pursuing plastic tactics, but a less flexible regulation for males using a fixed tactic throughout life. Furthermore, androgen profiles may respond to changes in the social environment, as predicted by the social reciprocity models of hormone/behaviour interactions. The cichlid fish Lamprologus callipterus provides a rare opportunity to study the roles of androgens for male ARTs within a single species, because fixed and plastic ARTs coexist. We experimentally exposed males to competitors pursuing either the same or different tactics to test predictions of the relative plasticity and the social reciprocity models. Androgen profiles of different male types partly comply with predictions derived from the relative plasticity hypothesis: males of the plastic bourgeois/sneaker male trajectory showed different 11-ketotestosterone (11-KT) levels when pursuing either bourgeois or parasitic sneaker male behaviours. Surprisingly, males pursuing the fixed dwarf male tactic showed the highest free and conjugated 11-KT and testosterone (T) levels. Our experimental social challenges significantly affected the free 11-KT levels of bourgeois males, but the androgen responses did not differ between challenges involving different types of competitors. Furthermore, the free T-responses of the bourgeois males correlated with their aggressive behaviour exhibited against competitors. Our results provide new insights into the endocrine responsiveness of fixed and plastic ARTs, confirming and refuting some predictions of both the relative plasticity and the social reciprocity models. © 2016. Published by The Company of Biologists Ltd.

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

"Promotores'" Perspectives on a Male-to-Male Peer Network

ERIC Educational Resources Information Center

Macia, Laura; Ruiz, Hector Camilo; Boyzo, Roberto; Documet, Patricia Isabel

2016-01-01

Little documentation exists about male community health workers ("promotores") networks. The experiences of "promotores" can provide input on how to attract, train, supervise and maintain male "promotores" in CHW programs. We present the experience and perspectives of "promotores" who participated in a male…

Sneaker Males Affect Fighter Male Body Size and Sexual Size Dimorphism in Salmon.

PubMed

Weir, Laura K; Kindsvater, Holly K; Young, Kyle A; Reynolds, John D

2016-08-01

Large male body size is typically favored by directional sexual selection through competition for mates. However, alternative male life-history phenotypes, such as "sneakers," should decrease the strength of sexual selection acting on body size of large "fighter" males. We tested this prediction with salmon species; in southern populations, where sneakers are common, fighter males should be smaller than in northern populations, where sneakers are rare, leading to geographical clines in sexual size dimorphism (SSD). Consistent with our prediction, fighter male body size and SSD (fighter male∶female size) increase with latitude in species with sneaker males (Atlantic salmon Salmo salar and masu salmon Oncorhynchus masou) but not in species without sneakers (chum salmon Oncorhynchus keta and pink salmon Oncorhynchus gorbuscha). This is the first evidence that sneaker males affect SSD across populations and species, and it suggests that alternative male mating strategies may shape the evolution of body size.

Triadic awareness predicts partner choice in male-infant-male interactions in Barbary macaques.

PubMed

Kubenova, Barbora; Konecna, Martina; Majolo, Bonaventura; Smilauer, Petr; Ostner, Julia; Schülke, Oliver

2017-03-01

Social knowledge beyond one's direct relationships is a key in successfully manoeuvring the social world. Individuals gather information on the quality of social relationships between their group companions, which has been termed triadic awareness. Evidence of the use of triadic awareness in natural contexts is limited mainly to conflict management. Here we investigated triadic awareness in wild Barbary macaques (Macaca sylvanus) in the context of bridging interactions defined as male-infant-male interactions whereby a male (initiator, holder) presents an infant to another male (receiver, non-holder) in order to initiate an affiliative interaction with that male. Analyses based on 1263 h of focal observations on ten infants of one wild social group in Morocco supported the hypothesis that males use their knowledge of the relationship between infants and other adult males when choosing a male as a partner for bridging interactions. Specifically, (i) the number of bridging interactions among holder-infant-receiver triads was positively affected by the strength of the infant-receiver relationship and (ii) when two males were available as bridging partners, a male was more likely to be chosen as the receiver the stronger his social relationship with the infant relative to the other available male. This demonstrates that non-human primates establish triadic awareness of temporary infant-male relationships and use it in a naturally occurring affiliative context. Our results contribute to the discussion about the mechanism underlying the acquisition of triadic awareness and the benefits of its usage, and lend support to hypotheses linking social complexity to the evolution of complex cognition.

Male and female voices activate distinct regions in the male brain.

PubMed

Sokhi, Dilraj S; Hunter, Michael D; Wilkinson, Iain D; Woodruff, Peter W R

2005-09-01

In schizophrenia, auditory verbal hallucinations (AVHs) are likely to be perceived as gender-specific. Given that functional neuro-imaging correlates of AVHs involve multiple brain regions principally including auditory cortex, it is likely that those brain regions responsible for attribution of gender to speech are invoked during AVHs. We used functional magnetic resonance imaging (fMRI) and a paradigm utilising 'gender-apparent' (unaltered) and 'gender-ambiguous' (pitch-scaled) male and female voice stimuli to test the hypothesis that male and female voices activate distinct brain areas during gender attribution. The perception of female voices, when compared with male voices, affected greater activation of the right anterior superior temporal gyrus, near the superior temporal sulcus. Similarly, male voice perception activated the mesio-parietal precuneus area. These different gender associations could not be explained by either simple pitch perception or behavioural response because the activations that we observed were conjointly activated by both 'gender-apparent' and 'gender-ambiguous' voices. The results of this study demonstrate that, in the male brain, the perception of male and female voices activates distinct brain regions.

Male contraceptive technology for nonhuman male mammals.

PubMed

Bowen, R A

2008-04-01

Contraceptive techniques applied to males have potential to mitigate diverse instances of overpopulation in human and animal populations. Different situations involving different species dictate that there is no ideal male contraceptive, and emphasizes the value of varying approaches to reducing male fertility. A majority of work in this field has focused on non-surgically destroying the testes or obstructing the epididymis, and suppressing gonadotropin secretion or inducing immune responses to reproductive hormones or sperm-specific antigens. Injection of tissue-destructive agents into the testes or epididymides can be very effective, but often is associated with unacceptable inflammatory responses and sometimes pain. Hormonal vaccines are often not efficacious and provide only short-term contraception, although GnRH vaccines may be an exception to this generality. Finally, there are no clearly effective contraceptive vaccines based on sperm antigens. Although several techniques have been developed to the point of commercialization, none has yet been widely deployed other than surgical castration.

Genetic evidence for monogamy in the dwarf seahorse, Hippocampus zosterae.

PubMed

Rose, Emily; Small, Clayton M; Saucedo, Hector A; Harper, Cristin; Jones, Adam G

2014-01-01

Syngnathid fishes (pipefishes, seahorses, and seadragons) exhibit a wide array of mating systems ranging from monogamy with long-term pair bonds to more promiscuous mating systems, such as polyandry and polygynandry. Some seahorses, including the dwarf seahorse Hippocampus zosterae, have been found to be socially monogamous. Although several seahorse species have also been shown to be genetically monogamous, parentage analysis has not yet been applied to the dwarf seahorse. We developed 8 novel microsatellites for the dwarf seahorse to conduct genetic parentage analysis to confirm that this species is indeed monogamous. Using 4 selected loci and a total of 16 pregnant male seahorses, with 8 collected in Florida and 8 sampled in Texas, we genotyped all of the offspring within each male's brood to determine the maternal contributions to each brood. We found a maximum of 4 alleles per locus segregating within each pregnant male's brood, a pattern consistent with each brood having exactly 1 mother and 1 father. These results support previous laboratory-based behavioral studies and indicate that the dwarf seahorse, H. zosterae, is genetically monogamous. © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Estrogens in Male Physiology.

PubMed

Cooke, Paul S; Nanjappa, Manjunatha K; Ko, CheMyong; Prins, Gail S; Hess, Rex A

2017-07-01

Estrogens have historically been associated with female reproduction, but work over the last two decades established that estrogens and their main nuclear receptors (ESR1 and ESR2) and G protein-coupled estrogen receptor (GPER) also regulate male reproductive and nonreproductive organs. 17β-Estradiol (E2) is measureable in blood of men and males of other species, but in rete testis fluids, E2 reaches concentrations normally found only in females and in some species nanomolar concentrations of estrone sulfate are found in semen. Aromatase, which converts androgens to estrogens, is expressed in Leydig cells, seminiferous epithelium, and other male organs. Early studies showed E2 binding in numerous male tissues, and ESR1 and ESR2 each show unique distributions and actions in males. Exogenous estrogen treatment produced male reproductive pathologies in laboratory animals and men, especially during development, and studies with transgenic mice with compromised estrogen signaling demonstrated an E2 role in normal male physiology. Efferent ductules and epididymal functions are dependent on estrogen signaling through ESR1, whose loss impaired ion transport and water reabsorption, resulting in abnormal sperm. Loss of ESR1 or aromatase also produces effects on nonreproductive targets such as brain, adipose, skeletal muscle, bone, cardiovascular, and immune tissues. Expression of GPER is extensive in male tracts, suggesting a possible role for E2 signaling through this receptor in male reproduction. Recent evidence also indicates that membrane ESR1 has critical roles in male reproduction. Thus estrogens are important physiological regulators in males, and future studies may reveal additional roles for estrogen signaling in various target tissues. Copyright © 2017 the American Physiological Society.

Condition-dependent female preference for male genitalia length is based on male reproductive tactics.

PubMed

Hernandez-Jimenez, Armando; Rios-Cardenas, Oscar

2017-12-06

There is extensive morphological variation of male genitalia across animals with internal fertilization, even among closely related species. Most studies attempting to explain this extraordinary diversity have focused on processes that occur post-copula (e.g. sperm competition, cryptic female choice). Only a few studies have focused on the pre-copula process of female preference. In addition, the extent to which this variation could be associated with the use of different reproductive tactics has yet to be explored. Here, we show that female preference for male genitalia length in two livebearing fishes depends on the type of reproductive tactic of the males being evaluated as well as the body condition of the female. In a species where all males coax females to acquire matings (courters), females preferred males with short genitalia. In a species with genetically influenced alternative reproductive tactics (courter males that only court and produce courter sons, sneaker males that use the coercive tactic of sneak chase and produce sneaker sons), female preference depended on an interaction between male tactic and female condition: females in good condition preferred courter males with short genitalia, and sneaker males with long genitalia. Our results suggest that female preference for male traits favourable to their sons may be an important factor contributing to the diversification of male genitalia. Despite the contrasting selection for genitalia length that our female preference tests suggest, we found no significant differences in genitalia length between coaxing (courters) and coercive (sneakers) males. Our study represents a starting point to more clearly understand the role of alternative reproductive tactics and variation in female mate preference in the evolution of male genitalia. © 2017 The Author(s).

[Male pseudohermaphroditism].

PubMed

Fukutani, K

1997-11-01

Male pseudohermaphroditism is a condition of sex differentiation disorders in which the gonads are tests, but the genital ducts and/or external genitalia are incompletely masculinized. This syndrome is caused by a failure of the sequential process in embryonal development of the testis. In the presence of functioning testis the Müllerian ducts regress, while the mesonephric ducts and urogenital sinus differentiate into the internal and external male genitalia. Male pseudohermaphroditism is classified to subtypes according to etiological factors: (1) testicular unresponsiveness to hCG and LH; (2) defect in testosterone biosynthesis; (3) end-organ resistance to androgen; (4) defects in the intracellular metabolism of testosterone; (5) aberrations in testicular organogenesis; (6) defects in anti-Müllerian hormone.

Male-Male Mounting Behaviour in Free-Ranging Golden Snub-Nosed Monkeys (Rhinopithecus roxellana).

PubMed

Fang, Gu; Dixson, Alan F; Qi, Xiao-Guang; Li, Bao-Guo

2018-01-01

An all-male band of golden snub-nosed monkeys (Rhinopithecus roxellana) was observed for 3 months in the Qinling Mountains of China, in order to collect data on the frequencies and contextual significance of male-male mounting behaviour. Mounts occurred in a variety of affiliative, dominance-related and sexual contexts, which differed depending upon the ages of the males involved. Mounting behaviour in this group was mainly initiated by adults. Juveniles mounted each other in affiliative contexts (during play and prior to grooming). Adult males mounted subadult and juvenile partners in a greater variety of sociosexual contexts (dominance/rank-related interactions; reconciliation following agonistic encounters, and sometimes as a prelude to receiving grooming). However, subadults and juveniles were never observed to mount adults. In one dyad, involving an adult male and a subadult partner, mounting was more frequent and prolonged, and included bouts of deep pelvic thrusting. Two mounts resulted in anal intromissions and, in 1 case, the subadult partner exhibited seminal emission. Given that the study took place during the annual mating peak period of R. roxellana, it is possible that this unusual male-male sexual activity was related to the absence of mating opportunities for those adults that were excluded from 1-male units. © 2018 S. Karger AG, Basel.

Female sticklebacks use male coloration in mate choice and hence avoid parasitized males

NASA Astrophysics Data System (ADS)

Milinski, Manfred; Bakker, Theo C. M.

1990-03-01

AN important problem in evolutionary biology since the time of Darwin has been to understand why females preferentially mate with males handicapped by secondary sexual ornaments1-3. One hypothesis of sexual selection theory is that these ornaments reliably reveal the male's condition4-6, which can be affected for example by parasites4,7-13. Here we show that in the three-spined stickleback (Gasterosteus aculeatus) the intensity of male red breeding coloration positively correlates with physical condition. Gravid females base their active mate choice on the intensity of the male's red coloration. Choice experiments under green light prevent the use of red colour cues by females, and males that were previously preferred are now chosen no more than randomly, although the courtship behaviour of the males remains unchanged. Parasitieation causes a deterioration in the males' condition and a decrease in the intensity of their red coloration. Tests under both lighting conditions reveal that the females recognize the formerly parasitized males by the lower intensity of their breeding coloration. Female sticklebacks possibly select a male with a good capacity for paternal care14 but if there is additive genetic variation for parasite resistance, then they might also select for resistance genes, as proposed by Hamilton and Zuk4.

Heterosexual men's anger in response to male homosexuality: effects of erotic and non-erotic depictions of male-male intimacy and sexual prejudice.

PubMed

Hudepohl, Adam D; Parrott, Dominic J; Zeichner, Amos

2010-01-01

The present study compared effects of erotic and non-erotic depictions of male-male intimacy on the experience of anger in heterosexual men. Data came from three independent laboratory studies designed to elicit anger in response to erotic or non-erotic depictions of male-male and male-female intimacy. All participants completed a measure of sexual prejudice and anger was assessed before and after viewing the erotic or non-erotic video. Among high-prejudiced men, viewing erotic and non-erotic intimate behavior between two men elicited significant increases in anger relative to viewing comparable behavior between a male-female dyad. In contrast, among low-prejudiced men, viewing erotic, but not non-erotic, intimate behavior between two men elicited significant increases in anger relative to viewing comparable behavior between a male-female dyad. Implications for understanding heterosexual men's anger, and aggression, toward gay men were discussed.

Heterosexual Men's Anger in Response to Male Homosexuality: Effects of Erotic and Non-Erotic Depictions of Male-Male Intimacy and Sexual Prejudice

PubMed Central

Hudepohl, Adam D.; Parrott, Dominic J.; Zeichner, Amos

2010-01-01

The present study compared effects of erotic and non-erotic depictions of male-male intimacy on the experience of anger in heterosexual men. Data came from three independent laboratory studies designed to elicit anger in response to erotic or non-erotic depictions of male-male and male-female intimacy. All participants completed a measure of sexual prejudice and anger was assessed before and after viewing the erotic or non-erotic video. Among high-prejudiced men, viewing erotic and non-erotic intimate behavior between two men elicited significant increases in anger relative to viewing comparable behavior between a male-female dyad. In contrast, among low-prejudiced men, viewing erotic, but not non-erotic, intimate behavior between two men elicited significant increases in anger relative to viewing comparable behavior between a male-female dyad. Implications for understanding heterosexual men's anger, and aggression, toward gay men were discussed. PMID:20818528

Male depression in females?

PubMed

Möller-Leimkühler, Anne Maria; Yücel, Mete

2010-02-01

Scientific evidence for a male-typed depression ("male depression") is still limited, but mainly supports this concept with respect to single externalizing symptoms or symptom clusters. In particular, studies on non-clinical populations including males and females are lacking. The present study aims at assessing general well-being, the risk and the symptoms of male depression dependent on biological sex and gender-role orientation on instrumental (masculine) and expressive (feminine) personality traits in an unselected community sample of males and females. Students (518 males, 500 females) of the Ludwig-Maximilians-University of Munich, Germany, were asked to participate in a "stress study" and complete the following self-report questionnaires: the WHO-5 Well-being Index [Bech, P., 1998. Quality of Life in the Psychiatric Patient. Mosby-Wolfe, London], the Gotland Scale for Male Depression [Walinder, J., Rutz, W., 2001. Male depression and suicide. International Clinical Psychopharmacology 16 (suppl 2), 21-24] and the German Extended Personal Attribute Questionnaire [Runge, T.E., Frey, D., Gollwitzer, P.M., et al., 1981. Masculine (instrumental) and feminine (expressive) traits. A comparison between students in the United States and West Germany. Journal of Cross-Cultural Psychology 12, 142-162]. General well-being of the students was significantly lower compared to population norms. Contrary to expectations, female students had a greater risk of male depression than male students (28.9% vs. 22.4%; p<0.05). Overall, prototypic depressive symptoms as well as externalizing symptoms were more pronounced in females. In the subgroup of those at risk for male depression, biological sex and kind of symptoms were unrelated. Principal component analyses revealed a similar symptom structure for males and females. Low scores on masculinity/instrumentality significantly predicted higher risk of male depression, independent of biological sex. The study sample is not

Male Body Practices.

PubMed

Lefkowich, Maya; Oliffe, John L; Hurd Clarke, Laura; Hannan-Leith, Madeline

2017-03-01

The pressure on boys and men to engage in extensive body practices (e.g., closely monitored eating and exercise habits) and achieve ideal male bodies has grown significantly over the past 20 years. Central to the depiction of ideal male bodies and body practices are both the pursuit and achievement of lean and well-defined muscles. The labels "pitches," "purchases," and "performativities" were inductively derived from the literature, and used to describe the multifaceted connections between masculinities, muscularity, and idealized male body practices. "Pitches" distil how popular culture posture norms of masculinity, and manly bodies and behaviors attainable and necessary. "Purchases" refer to men's diverse buy-in to dominant discourses about acceptable male bodies and practices. "Performativities" chronicle how men embody and navigate gender norms as they evaluate their own bodies, behaviors, and eating habits and those of their peers. Based on findings from the current scoping review, future research could benefit from fully linking masculinities with the drive for muscularity to address health and social risks associated with the pursuit of the idealized male body. In highlighting the plurality of masculinities and the complexity of men's diverse identities, health care providers can better reach and support men. Focusing on, and celebrating, a wider range of male bodies could help recenter dominant discourses about how and whose bodies and experiences are idealized. The current scoping review article offers an overview of how masculinities and muscularity have been linked to male body practices, and recommendations to advance this emergent field.

Male Body Practices

PubMed Central

Lefkowich, Maya; Oliffe, John L.; Hurd Clarke, Laura; Hannan-Leith, Madeline

2016-01-01

The pressure on boys and men to engage in extensive body practices (e.g., closely monitored eating and exercise habits) and achieve ideal male bodies has grown significantly over the past 20 years. Central to the depiction of ideal male bodies and body practices are both the pursuit and achievement of lean and well-defined muscles. The labels “pitches,” “purchases,” and “performativities” were inductively derived from the literature, and used to describe the multifaceted connections between masculinities, muscularity, and idealized male body practices. “Pitches” distil how popular culture posture norms of masculinity, and manly bodies and behaviors attainable and necessary. “Purchases” refer to men’s diverse buy-in to dominant discourses about acceptable male bodies and practices. “Performativities” chronicle how men embody and navigate gender norms as they evaluate their own bodies, behaviors, and eating habits and those of their peers. Based on findings from the current scoping review, future research could benefit from fully linking masculinities with the drive for muscularity to address health and social risks associated with the pursuit of the idealized male body. In highlighting the plurality of masculinities and the complexity of men’s diverse identities, health care providers can better reach and support men. Focusing on, and celebrating, a wider range of male bodies could help recenter dominant discourses about how and whose bodies and experiences are idealized. The current scoping review article offers an overview of how masculinities and muscularity have been linked to male body practices, and recommendations to advance this emergent field. PMID:27645513

Male-male competition and female choice are differentially affected by male call acoustics in the serrate-legged small treefrog, Kurixalus odontotarsus.

PubMed

Zhu, Bicheng; Wang, Jichao; Zhao, Longhui; Chen, Qinghua; Sun, Zhixin; Yang, Yue; Brauth, Steven E; Tang, Yezhong; Cui, Jianguo

2017-01-01

The evolution of exaggerated vocal signals in anuran species is an important topic. Males and females have both evolved the ability to discriminate communication sounds. However, the nature of sexual dimorphism in cognition and sensory discrimination and in the evolution and limitation of sexual signal exaggeration remain relatively unexplored. In the present study, we used male calls of varied complexity in the serrate-legged small treefrog, Kurixalus odontotarsus , as probes to investigate how both sexes respond to variations in call complexity and how sex differences in signal discrimination play a role in the evolution of sexual signal exaggeration. The compound calls of male K. odontotarsus consist of a series of one or more harmonic notes (A notes) which may be followed by one or more short broadband notes (B notes). Male playback experiments and female phonotaxis tests showed that increasing the number of A notes in stimulus calls elicits increased numbers of response calls by males and increases the attractiveness of the stimulus calls to females. The addition of B notes, however, reduces male calling responses. Moreover, call stimuli which contain only B notes suppress spontaneous male calling responses. Phonotaxis experiments show that females prefer calls with greater numbers of A notes and calls containing both A notes and B notes, but do not prefer calls with only B notes. Male-male competition and female choice appear to have played different roles in the evolution and limitation of signal complexity in K. odontotarsus . These results provide new insights into how exaggerated compound signals evolve and how signal complexity may be limited in anurans.

Postnatal nutrition influences male attractiveness and promotes plasticity in male mating preferences

NASA Astrophysics Data System (ADS)

Noguera, José C.; Metcalfe, Neil B.; Monaghan, Pat

2017-12-01

Poor early-life nutrition could reduce adult reproductive success by negatively affecting traits linked to sexual attractiveness such as song complexity. If so, this might favor strategic mate choice, allowing males with less complex songs to tailor their mating tactics to maximize the reproductive benefits. However, this possibility has been ignored in theoretical and empirical studies. By manipulating the micronutrient content of the diet (e.g., low or high) during the postnatal period of male zebra finches, we show for the first time (1) that males reared on a poor (low) micronutrient diet had less complex songs as adults; (2) that these males, in contrast to the high micronutrient diet group, were more selective in their mating strategies, discriminating against those females most likely to reduce their clutch size when paired with males having less complex songs; and (3) that by following different mating strategies, males reared on the contrasting diets obtained similar reproductive benefits. These results suggest that early-life dietary conditions can induce multiple and long-lasting effects on male and female reproductive traits. Moreover, the results seem to reflect a previously unreported case of adaptive plasticity in mate choice in response to a nutritionally mediated reduction in sexual attractiveness.

An increase in estradiol facilitates the onset of paternal behavior in the dwarf hamster (Phodopus campbelli).

PubMed

Romero-Morales, Luis; Martínez-Torres, Martín; Cárdenas, Mario; Álvarez, Carmen; Carmona, Agustín; Cedillo, Benita; Loya-Zurita, Eduardo; Luis, Juana

2018-03-01

In the dwarf hamster (Phodopus campbelli), activational effects of testosterone (T) and estradiol (E 2 ) in the regulation of paternal behavior have been repeatedly rejected because peripheral concentrations of E 2 do not change across the reproductive cycle of males. Further, castration no affected paternal behavior despite that both T and E 2 concentrations decreased significantly. However, the role of these hormones has not been evaluated in models of castration and hormonal replacement in virgin males. Here, we analysed the effects of E 2 and T in paternal behavior in virgin male dwarf hamster (Phodopus campbelli). Thirty paternal (PAT) males were bilaterally castrated; of them, 10 were implanted with T, 10 with E 2 and 10 males received no treatment. Other 10 PAT males underwent sham-castration. Seventeen aggressive (AGG) males were also bilaterally castrated; of these, 10 AGG received E 2 replacement, 7 were not treated. Other 7 AGG males were submitted to sham-castration. Following treatments, paternal behavior tests were conducted again. T and E 2 levels in plasma were quantified by radioimmunoassay (RIA). The results showed that the treatments did not affect the paternal behavior of males that were initially paternal. Neither castration nor sham-castration surgery affected the behavior of AGG males. However, when these males were treated with E 2 and the concentrations of this hormone increase significantly they became paternal. Our data suggest that an increase in E 2 levels shifted infanticidal behavior to paternal behavior in dwarf hamster. Copyright © 2018 Elsevier Inc. All rights reserved.

Prostatitis and male infertility.

PubMed

Alshahrani, Saad; McGill, John; Agarwal, Ashok

2013-11-01

The prostate gland plays an important role in male reproduction. Inflammation of the prostate gland (prostatitis) is a common health problem affecting many young and middle aged men. Prostatitis is considered a correctable cause of male infertility, but the pathophysiology and appropriate treatment options of prostatitis in male infertility remain unclear. This literature review will focus on current data regarding prostatitis and its impact on male infertility. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Free-Ranging Male Koalas Use Size-Related Variation in Formant Frequencies to Assess Rival Males

PubMed Central

Charlton, Benjamin D.; Whisson, Desley A.; Reby, David

2013-01-01

Although the use of formant frequencies in nonhuman animal vocal communication systems has received considerable recent interest, only a few studies have examined the importance of these acoustic cues to body size during intra-sexual competition between males. Here we used playback experiments to present free-ranging male koalas with re-synthesised bellow vocalisations in which the formants were shifted to simulate either a large or a small adult male. We found that male looking responses did not differ according to the size variant condition played back. In contrast, male koalas produced longer bellows and spent more time bellowing when they were presented with playbacks simulating larger rivals. In addition, males were significantly slower to respond to this class of playback stimuli than they were to bellows simulating small males. Our results indicate that male koalas invest more effort into their vocal responses when they are presented with bellows that have lower formants indicative of larger rivals, but also show that males are slower to engage in vocal exchanges with larger males that represent more dangerous rivals. By demonstrating that male koalas use formants to assess rivals during the breeding season we have provided evidence that male-male competition constitutes an important selection pressure for broadcasting and attending to size-related formant information in this species. Further empirical studies should investigate the extent to which the use of formants during intra-sexual competition is widespread throughout mammals. PMID:23922967

Vocal communication between male Xenopus laevis.

PubMed

Tobias, Martha L; Barnard, Candace; O'Hagan, Robert; Horng, Sam H; Rand, Masha; Kelley, Darcy B

2004-02-01

This study focuses on the role of male-male vocal communication in the reproductive repertoire of the South African clawed frog, Xenopus laevis . Six male and two female call types were recorded from native ponds in the environs of Cape Town, South Africa. These include all call types previously recorded in the laboratory as well as one previously unidentified male call: chirping. The amount of calling and the number of call types increased as the breeding season progressed. Laboratory recordings indicated that all six male call types were directed to males; three of these were directed to both sexes and three were directed exclusively to males. Both female call types were directed exclusively to males. The predominant call type, in both field and laboratory recordings, was the male advertisement call. Sexual state affected male vocal behaviour. Male pairs in which at least one male was sexually active (gonadotropin injected) produced all call types, whereas pairs of uninjected males rarely called. Some call types were strongly associated with a specific behaviour and others were not. Clasped males always growled and clasping males typically produced amplectant calls or chirps; males not engaged in clasping most frequently advertised. The amount of advertising produced by one male was profoundly affected by the presence of another male. Pairing two sexually active males resulted in suppression of advertisement calling in one; suppression was released when males were isolated after pairing. Vocal dominance was achieved even in the absence of physical contact (clasping). We suggest that X. laevis males gain a reproductive advantage by competing for advertisement privileges and by vocally suppressing neighbouring males.

Older males signal more reliably.

PubMed Central

Proulx, Stephen R; Day, Troy; Rowe, Locke

2002-01-01

The hypothesis that females prefer older males because they have higher mean fitness than younger males has been the centre of recent controversy. These discussions have focused on the success of a female who prefers males of a particular age class when age cues, but not quality cues, are available. Thus, if the distribution of male quality changes with age, such that older males have on average genotypes with higher fitness than younger males, then a female who mates with older males has fitter offspring, which allows the female preference to spread through a genetic correlation. We develop a general model for male display in a species with multiple reproductive bouts that allows us to identify the conditions that promote reliable signalling within an age class. Because males have opportunities for future reproduction, they will reduce their levels of advertising compared with a semelparous species. In addition, because higher-quality males have more future reproduction, they will reduce their advertising more than low-quality males. Thus, the conditions for reliable signalling in a semelparous organism are generally not sufficient to produce reliable signalling in species with multiple reproductive bouts. This result is due to the possibility of future reproduction so that, as individuals age and the opportunities for future reproduction fade, signalling becomes more reliable. This provides a novel rationale for female preference for older mates; older males reveal more information in their sexual displays. PMID:12495495

Influence of male morphology on male mating status and behavior during interunit encounters in western lowland gorillas.

PubMed

Caillaud, Damien; Levréro, Florence; Gatti, Sylvain; Ménard, Nelly; Raymond, Michel

2008-04-01

The western lowland gorilla (Gorilla gorilla gorilla) is one of the most sexually dimorphic primate species. Mature males are twice the size of females and have grey fur on their backs and a fibrous, adipose crest on their heads. Such traits are likely to have evolved by sexual selection, either because they confer advantages during male-male fights or because females prefer males with more dimorphic traits. We developed photogrammetric methods for distance collection of morphological data from silverback males frequenting the Lokoué forest clearing in Odzala-Kokoua National Park, Republic of the Congo. Body length, head-crest size, musculature development, and extent of the grey color on the back were assessed in 87 nonbreeding and breeding mature males. Behavioral data were also collected during 312 male-male encounters involving 67 mature males in order to estimate their level of aggressiveness. The number of females belonging to a mature male positively correlated with the male crest size, body length, and musculature. Whereas morphological variables did not significantly affect the intensity of male-male encounters, the number of females attending male-male encounters strongly affected the number of agonistic displays by the two males. We discuss the mechanisms through which males with more exaggerated traits could obtain a mating advantage, namely male-male fights or female mate choice. (c) 2007 Wiley-Liss, Inc.

Relative importance of male and territory quality in pairing success of male rock ptarmigan (Lagopus mutus)

USGS Publications Warehouse

Bart, Jonathan; Earnst, Susan L.

1999-01-01

We studied pairing success in male rock ptarmigan (Lagopus mutus) in northern Alaska to learn whether males obtaining more females possessed phenotypic traits that influenced female choice directly, whether these traits permitted males to obtain territories favored by females, or whether both processes occurred. The number of females per male varied from zero to three. Several male and territory traits were significantly correlated with number of females per male. We used multiple regression to obtain a single measure of male quality and a single measure of territory quality. These measures of male and territory quality correlated with each other and with male pairing success. We used path analysis to separate direct effects of male quality on pairing success from indirect effects due to high-quality males obtaining high-quality territories. Both direct and indirect pathways had significant effects on pairing success, and direct and indirect effects of male traits on pairing success were about equal. This study illustrates an analytical approach for estimating the relative importance of direct and indirect causal relationships in natural systems.

Sneaker "jack" males outcompete dominant "hooknose" males under sperm competition in Chinook salmon (Oncorhynchus tshawytscha).

PubMed

Young, Brent; Conti, David V; Dean, Matthew D

2013-12-01

In a variety of taxa, males deploy alternative reproductive tactics to secure fertilizations. In many species, small "sneaker" males attempt to steal fertilizations while avoiding encounters with larger, more aggressive, dominant males. Sneaker males usually face a number of disadvantages, including reduced access to females and the higher likelihood that upon ejaculation, their sperm face competition from other males. Nevertheless, sneaker males represent an evolutionarily stable strategy under a wide range of conditions. Game theory suggests that sneaker males compensate for these disadvantages by investing disproportionately in spermatogenesis, by producing more sperm per unit body mass (the "fair raffle") and/or by producing higher quality sperm (the "loaded raffle"). Here, we test these models by competing sperm from sneaker "jack" males against sperm from dominant "hooknose" males in Chinook salmon. Using two complementary approaches, we reject the fair raffle in favor of the loaded raffle and estimate that jack males were ∼1.35 times as likely as hooknose males to fertilize eggs under controlled competitive conditions. Interestingly, the direction and magnitude of this skew in paternity shifted according to individual female egg donors, suggesting cryptic female choice could moderate the outcomes of sperm competition in this externally fertilizing species.

Within-male melanin-based plumage and bill elaboration in male house sparrows.

PubMed

Václav, Radovan

2006-12-01

If there is a cost to producing a dark color patch, the size of a patch may not correspond with its pigment concentration. The plumage of male house sparrows represents a case of dark, melanin-based ornamentation, but also a case of neglecting the composite nature of dark signals in birds. Here, I investigated what kind of associations exist between the brightness, chroma, and hue of dark integumentary patches and the size of a secondary sexual trait, the bib, in male house sparrows. I found that males with a larger bib also had a darker bib and bill, and a more saturated bib, bill, epaulets, head crown, and breast than small-bibbed males. Male bib coloration in terms of brightness and chroma was more strongly related to bib size than the coloration of other integumentary patches. However, with respect to hue, only the hue of the bill and cheeks was related to bib size. My results indicate that size, brightness, and chroma of the bib, but also chroma of other deeply colored patches, convey redundant information about the signaler's quality in male house sparrows.

Will male advertisement be a reliable indicator of paternal care, if offspring survival depends on male care?

PubMed Central

Kelly, Natasha B.; Alonzo, Suzanne H.

2009-01-01

Existing theory predicts that male signalling can be an unreliable indicator of paternal care, but assumes that males with high levels of mating success can have high current reproductive success, without providing any parental care. As a result, this theory does not hold for the many species where offspring survival depends on male parental care. We modelled male allocation of resources between advertisement and care for species with male care where males vary in quality, and the effect of care and advertisement on male fitness is multiplicative rather than additive. Our model predicts that males will allocate proportionally more of their resources to whichever trait (advertisement or paternal care) is more fitness limiting. In contrast to previous theory, we find that male advertisement is always a reliable indicator of paternal care and male phenotypic quality (e.g. males with higher levels of advertisement never allocate less to care than males with lower levels of advertisement). Our model shows that the predicted pattern of male allocation and the reliability of male signalling depend very strongly on whether paternal care is assumed to be necessary for offspring survival and how male care affects offspring survival and male fitness. PMID:19520802

Will male advertisement be a reliable indicator of paternal care, if offspring survival depends on male care?

PubMed

Kelly, Natasha B; Alonzo, Suzanne H

2009-09-07

Existing theory predicts that male signalling can be an unreliable indicator of paternal care, but assumes that males with high levels of mating success can have high current reproductive success, without providing any parental care. As a result, this theory does not hold for the many species where offspring survival depends on male parental care. We modelled male allocation of resources between advertisement and care for species with male care where males vary in quality, and the effect of care and advertisement on male fitness is multiplicative rather than additive. Our model predicts that males will allocate proportionally more of their resources to whichever trait (advertisement or paternal care) is more fitness limiting. In contrast to previous theory, we find that male advertisement is always a reliable indicator of paternal care and male phenotypic quality (e.g. males with higher levels of advertisement never allocate less to care than males with lower levels of advertisement). Our model shows that the predicted pattern of male allocation and the reliability of male signalling depend very strongly on whether paternal care is assumed to be necessary for offspring survival and how male care affects offspring survival and male fitness.

[Acceptability of male circumcision among male miners in Baise of Guangxi].

PubMed

Luo, Hao; Liang, Xu; Chen, Jian; Yang, Xiao-bo; Jiang, Jun-jun; Deng, Wei; Zou, Yun-feng; Wei, Bo; Zhang, Zhi-yong; Liu, Zhi-hao; Liang, Hao

2011-06-01

To investigate the acceptability of male circumcision among male miners in Baise, Guangxi, China. A questionnaire-based survey on the willingness to be circumcised (WTC) and its influential factors were conducted among Guangxi male miners recruited by random cluster sampling. Of 569 subjects who were surveyed, 143 (25.13%) expressed their willingness to be circumcised. Univariate analysis showed that marital status, education level, and the awareness of the hazards of phimosis and redundant prepuce and reasons for circumcision were significantly different between WTC group and the non-WTC group (all P<0.05). Furthermore, the incidence of phimosis or redundant prepuce also significantly differed between these two groups (P=0.0001). Logistic regression analysis found marital status (OR=0.498ì95%CI=0.272-0.913), history of foreskin disease (OR=8.181, 95%CI=4.252-15.741), and awareness of the risk that a redundant prepuce may cause smegma (OR=1.713ì95%CI=1.090-2.693) were significantly correlated with the male miners WTC. Male miners in this area have low WTC. Education on the basic knowledge of acquired immunodeficiency syndrome and circumcision may help promote the application of circumcision.

Sexually selected nest-building--Pomatoschistus minutus males build smaller nest-openings in the presence of sneaker males.

PubMed

Svensson, O; Kvarnemo, C

2003-09-01

Both natural selection and sexual selection may act on nest-building. We tested experimentally how different regimes of egg-predation and male-male competition influence nest-building before mating, using the marine fish sand goby, Pomatoschistus minutus. Males with sneaker males present built the smallest nest-openings, smaller than males held alone or with Pomatoschistus microps males (which may predate eggs and compete over nest-sites but not compete over fertilizations). Males with visual access to other nest-building males tended also to build smaller openings than males held alone or with P. microps. Males with egg-predators present built nests with openings not differing significantly from any other treatment. Our results indicate that the small nest-openings found in the sneaker male treatment are sexually selected through protection against sneaking or by female choice. Across treatments, time span before a male started to build his nest also explained variation in nest-opening width; males starting late built larger nest-openings.

Phylogeny of Courtship and Male-Male Combat Behavior in Snakes

PubMed Central

Senter, Phil; Harris, Shannon M.; Kent, Danielle L.

2014-01-01

Background Behaviors involved in courtship and male-male combat have been recorded in a taxonomically broad sample (76 species in five families) of snakes in the clade Boidae + Colubroidea, but before now no one has attempted to find phylogenetic patterns in such behaviors. Here, we present a study of phylogenetic patterns in such behaviors in snakes. Methodology/Principal Findings From the literature on courtship and male-male combat in snakes we chose 33 behaviors to analyze. We plotted the 33 behaviors onto a phylogenetic tree to determine whether phylogenetic patterns were discernible. We found that phylogenetic patterns are discernible for some behaviors but not for others. For behaviors with discernible phylogenetic patterns, we used the fossil record to determine minimum ages for the addition of each behavior to the courtship and combat behavioral repertoire of each snake clade. Conclusions/Significance The phylogenetic patterns of behavior reveal that male-male combat in the Late Cretaceous common ancestors of Boidae and Colubridae involved combatants raising the head and neck and attempting to topple each other. Poking with spurs was added in Boidae. In Lampropeltini the toppling behavior was replaced by coiling without neck-raising, and body-bridging was added. Phylogenetic patterns reveal that courtship ancestrally involved rubbing with spurs in Boidae. In Colubroidea, courtship ancestrally involved chin-rubbing and head- or body-jerking. Various colubroid clades subsequently added other behaviors, e.g. moving undulations in Natricinae and Lampropeltini, coital neck biting in the Eurasian ratsnake clade, and tail quivering in Pantherophis. The appearance of each group in the fossil record provides a minimum age of the addition of each behavior to combat and courtship repertoires. Although many gaps in the story of the evolution of courtship and combat in snakes remain, this study is an important first step in the reconstruction of the evolution of these

Phylogeny of courtship and male-male combat behavior in snakes.

PubMed

Senter, Phil; Harris, Shannon M; Kent, Danielle L

2014-01-01

Behaviors involved in courtship and male-male combat have been recorded in a taxonomically broad sample (76 species in five families) of snakes in the clade Boidae + Colubroidea, but before now no one has attempted to find phylogenetic patterns in such behaviors. Here, we present a study of phylogenetic patterns in such behaviors in snakes. From the literature on courtship and male-male combat in snakes we chose 33 behaviors to analyze. We plotted the 33 behaviors onto a phylogenetic tree to determine whether phylogenetic patterns were discernible. We found that phylogenetic patterns are discernible for some behaviors but not for others. For behaviors with discernible phylogenetic patterns, we used the fossil record to determine minimum ages for the addition of each behavior to the courtship and combat behavioral repertoire of each snake clade. The phylogenetic patterns of behavior reveal that male-male combat in the Late Cretaceous common ancestors of Boidae and Colubridae involved combatants raising the head and neck and attempting to topple each other. Poking with spurs was added in Boidae. In Lampropeltini the toppling behavior was replaced by coiling without neck-raising, and body-bridging was added. Phylogenetic patterns reveal that courtship ancestrally involved rubbing with spurs in Boidae. In Colubroidea, courtship ancestrally involved chin-rubbing and head- or body-jerking. Various colubroid clades subsequently added other behaviors, e.g. moving undulations in Natricinae and Lampropeltini, coital neck biting in the Eurasian ratsnake clade, and tail quivering in Pantherophis. The appearance of each group in the fossil record provides a minimum age of the addition of each behavior to combat and courtship repertoires. Although many gaps in the story of the evolution of courtship and combat in snakes remain, this study is an important first step in the reconstruction of the evolution of these behaviors in snakes.

Diploid male dynamics under different numbers of sexual alleles and male dispersal abilities.

PubMed

Faria, Luiz R R; Soares, Elaine Della Giustina; Carmo, Eduardo do; Oliveira, Paulo Murilo Castro de

2016-09-01

Insects in the order Hymenoptera (bees, wasps and ants) present an haplodiploid system of sexual determination in which fertilized eggs become females and unfertilized eggs males. Under single locus complementary sex-determination (sl-CSD) system, the sex of a specimen depends on the alleles at a single locus: when diploid, an individual will be a female if heterozygous and male if homozygous. Significant diploid male (DM) production may drive a population to an extinction scenario called "diploid male vortex". We aimed at studying the dynamics of populations of a sl-CSD organism under several combinations of two parameters: male flight abilities and number of sexual alleles. In these simulations, we evaluated the frequency of DM and a genetic diversity measure over 10,000 generations. The number of sexual alleles varied from 10 to 100 and, at each generation, a male offspring might fly to another random site within a varying radius R. Two main results emerge from our simulations: (i) the number of DM depends more on male flight radius than on the number of alleles; (ii) in large geographic regions, the effect of males flight radius on the allelic diversity turns out much less pronounced than in small regions. In other words, small regions where inbreeding normally appears recover genetic diversity due to large flight radii. These results may be particularly relevant when considering the population dynamics of species with increasingly limited dispersal ability (e.g., forest-dependent species of euglossine bees in fragmented landscapes).

Male Sling and Artificial Urethral Sphincter for Male Stress Urinary Incontinence Among Certifying American Urologists.

PubMed

Liu, Joceline S; Hofer, Matthias D; Milose, Jaclyn; Oberlin, Daniel T; Flury, Sarah C; Morey, Allen F; Gonzalez, Chris M

2016-01-01

To examine case volume characteristics among certifying urologists performing male sling and artificial urinary sphincter (AUS) procedures to evaluate practice patterns in male stress urinary incontinence (SUI). Six-month case log data of certifying urologists (2003-2013) were obtained from the American Board of Urology. Cases specifying Current Procedural Terminology code for male sling, AUS, and removal or revision of either procedure in males ≥18 years were analyzed. Among 1615 urologists (568 certifying and 1047 recertifying) logging at least 1 male incontinence procedure, 2109 (48% of all procedures) male sling and 2284 (52%) AUS cases were identified. The mean age of patients undergoing AUS was 74.9 years and the mean age of patients undergoing sling procedures was 67.3 years (P <.001). An increase in male incontinence procedures from 2003 to 2013 was demonstrated. The rate of male sling procedure increased from 32.7% of incontinence surgeries in 2004 to 45.5% in 2013 (P <.001). Academically affiliated urologists are 1.5 times more likely to perform AUS than male sling for SUI (P <.001). Median number of slings performed was 2 (range 1-40), with 32.7% placing slings exclusively. A small group of certifying urologists (3.4%) accounted for 22% of all male slings placed. This same cohort logged 10.2% of all AUS performed. Surgical management of male SUI varies widely across states (P <.001), with slings performed between 21% and 70% of the time. Overall the number of male incontinence procedures has increased over time, with a growing proportion of male slings. Most slings and AUS cases are performed by a small number of high-volume surgeons. Copyright © 2015 Elsevier Inc. All rights reserved.

Factors affecting aggressive behaviour of spawning migratory males towards mature male parr in masu salmon Oncorhynchus masou.

PubMed

Watanabe, M; Maekawa, K

2010-07-01

This study examined whether dominant migratory males (adopting fighter tactics) of the masu salmon Oncorhynchus masou would more aggressively attack large mature male parr (adopting sneaker tactics) as large mature male parr are expected to have the potential to cause a greater decrease in fertilization success. The frequency of aggressive behaviour was not related to the body size of males, and it increased with the frequency of interactions with mature male parr. The fertilization success of mature male parr was much lower than migratory males, and no relationship was observed between fertilization success and aggressive behaviour. The low fertilization success of mature male parr, despite infrequent aggressive behaviour by migratory males, indicates that there might be little benefit for migratory males to attack mature male parr more aggressively according to their body size.

Early-Life Social Isolation Influences Mouse Ultrasonic Vocalizations during Male-Male Social Encounters.

PubMed

Keesom, Sarah M; Finton, Caitlyn J; Sell, Gabrielle L; Hurley, Laura M

2017-01-01

Early-life social isolation has profound effects on adult social competence. This is often expressed as increased aggression or inappropriate displays of courtship-related behaviors. The social incompetence exhibited by isolated animals could be in part due to an altered ability to participate in communicatory exchanges. House mice (Mus musculus) present an excellent model for exploring this idea, because social isolation has a well-established influence on their social behavior, and mice engage in communication via multiple sensory modalities. Here, we tested the prediction that social isolation during early life would influence ultrasonic vocalizations (USVs) emitted by adult male mice during same-sex social encounters. Starting at three weeks of age, male mice were housed individually or in social groups of four males for five weeks, after which they were placed in one of three types of paired social encounters. Pair types consisted of: two individually housed males, two socially housed males, or an individually housed and a socially housed male ("mixed" pairs). Vocal behavior (USVs) and non-vocal behaviors were recorded from these 15-minute social interactions. Pairs of mice consisting of at least one individually housed male emitted more and longer USVs, with a greater proportional use of USVs containing frequency jumps and 50-kHz components. Individually housed males in the mixed social pairs exhibited increased levels of mounting behavior towards the socially housed males. Mounting in these pairs was positively correlated with increased number and duration of USVs as well as increased proportional use of spectrally more complex USVs. These findings demonstrate that USVs are part of the suite of social behaviors influenced by early-life social isolation, and suggest that altered vocal communication following isolation reflects reduced social competence.

Early-Life Social Isolation Influences Mouse Ultrasonic Vocalizations during Male-Male Social Encounters

PubMed Central

Finton, Caitlyn J.; Sell, Gabrielle L.; Hurley, Laura M.

2017-01-01

Early-life social isolation has profound effects on adult social competence. This is often expressed as increased aggression or inappropriate displays of courtship-related behaviors. The social incompetence exhibited by isolated animals could be in part due to an altered ability to participate in communicatory exchanges. House mice (Mus musculus) present an excellent model for exploring this idea, because social isolation has a well-established influence on their social behavior, and mice engage in communication via multiple sensory modalities. Here, we tested the prediction that social isolation during early life would influence ultrasonic vocalizations (USVs) emitted by adult male mice during same-sex social encounters. Starting at three weeks of age, male mice were housed individually or in social groups of four males for five weeks, after which they were placed in one of three types of paired social encounters. Pair types consisted of: two individually housed males, two socially housed males, or an individually housed and a socially housed male (“mixed” pairs). Vocal behavior (USVs) and non-vocal behaviors were recorded from these 15-minute social interactions. Pairs of mice consisting of at least one individually housed male emitted more and longer USVs, with a greater proportional use of USVs containing frequency jumps and 50-kHz components. Individually housed males in the mixed social pairs exhibited increased levels of mounting behavior towards the socially housed males. Mounting in these pairs was positively correlated with increased number and duration of USVs as well as increased proportional use of spectrally more complex USVs. These findings demonstrate that USVs are part of the suite of social behaviors influenced by early-life social isolation, and suggest that altered vocal communication following isolation reflects reduced social competence. PMID:28056078

The agricultural contaminant 17β-trenbolone disrupts male-male competition in the guppy (Poecilia reticulata).

PubMed

Tomkins, Patrick; Saaristo, Minna; Bertram, Michael G; Tomkins, Raymond B; Allinson, Mayumi; Wong, Bob B M

2017-11-01

Despite a growing literature highlighting the potential impact of human-induced environmental change on mechanisms of sexual selection, relatively little is known about the effects of chemical pollutants on male-male competition. One class of environmental pollutant likely to impact male competitive interactions is the endocrine-disrupting chemicals (EDCs), a large and heterogeneous group of chemical contaminants with the potential to influence morphology, physiology and behaviour at minute concentrations. One EDC of increasing concern is the synthetic, androgenic steroid 17β-trenbolone, which is used globally to promote growth in beef cattle. Although 17β-trenbolone has been found to cause severe morphological and behavioural abnormalities in fish, its potential impact on male-male competition has yet to be investigated. To address this, we exposed wild male guppies (Poecilia reticulata) to an environmentally realistic concentration of 17β-trenbolone (average measured concentration: 8 ng/L) for 21 days using a flow-through system. We found that, in the presence of a competitor, 17β-trenbolone-exposed males carried out more frequent aggressive behaviours towards rival males than did unexposed males, as well as performing less courting behaviour and more sneak (i.e., coercive) mating attempts towards females. Considering that, by influencing mating outcomes, male-male competition has important consequences for population dynamics and broader evolutionary processes, this study highlights the need for greater understanding of the potential impact of EDCs on the mechanisms of sexual selection. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Demand for male contraception.

PubMed

Dorman, Emily; Bishai, David

2012-10-01

The biological basis for male contraception was established decades ago, but despite promising breakthroughs and the financial burden men increasingly bear due to better enforcement of child support policies, no viable alternative to the condom has been brought to market. Men who wish to control their fertility must rely on female compliance with contraceptives, barrier methods, vasectomy or abstinence. Over the last 10 years, the pharmaceutical industry has abandoned most of its investment in the field, leaving only nonprofit organisations and public entities pursuing male contraception. Leading explanations are uncertain forecasts of market demand pitted against the need for critical investments to demonstrate the safety of existing candidate products. This paper explores the developments and challenges in male contraception research. We produce preliminary estimates of potential market size for a safe and effective male contraceptive based on available data to estimate the potential market for a novel male method.

Male fertility: psychiatric considerations.

PubMed

Hall, Elise; Burt, Vivien K

2012-02-01

To examine: 1) current knowledge on normal biologic variation of seminal parameters; 2) how stress and psychological factors affect sperm quality in fertile and infertile males; and 3) how mental illness and psychopharmacologic agents can affect male fertility. English-language Medline, Embase, and Psycinfo were searched for relevant publications (from 1970 to January 2011) for systematic review. None. None. None. Possible effects of stress, mood, and psychotropic medications on male factor fertility. Male-factor infertility is influenced by myriad factors (obesity, tobacco, etc.). Stress alone may reduce testosterone levels and spermatogenesis. Infertility assessment and treatment can lead to distress and negatively affect sperm samples. Available research has failed to control for potentially confounding variables. Although some trends have been identified, larger-scale studies that adequately control all confounding variables are needed before conclusions can be made about the relationship between stress, psychotropic agents, and male infertility. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

[Obesity and male infertility].

PubMed

Heráček, J; Sobotka, V; Urban, M

2012-10-01

The authors present a review on the effects of obesity on male fertility. Current scientific findings suggest an elevated risk of infertility among couples in which the male partner is obese. In obese men can be found reduced serum levels of androgens and SHBG and increased estrogen levels without compensatory increase in FSH. Among other impacts of male obesity that may contribute to increased risk of infertility are altered retention and metabolism of environmental toxins, lifestyle, sexual dysfunction, genetic factors, excessive secretion of hormones derived from adipose tissue, oxidative stress, sperm specific proteomic changes or elevated levels of cytokines. The increasing prevalence of obesity calls for greater clinical awareness of its impact on male fertility.

Quantifying male attractiveness.

PubMed Central

McNamara, John M; Houston, Alasdair I; Marques Dos Santos, Miguel; Kokko, Hanna; Brooks, Rob

2003-01-01

Genetic models of sexual selection are concerned with a dynamic process in which female preference and male trait values coevolve. We present a rigorous method for characterizing evolutionary endpoints of this process in phenotypic terms. In our phenotypic characterization the mate-choice strategy of female population members determines how attractive females should find each male, and a population is evolutionarily stable if population members are actually behaving in this way. This provides a justification of phenotypic explanations of sexual selection and the insights into sexual selection that they provide. Furthermore, the phenotypic approach also has enormous advantages over a genetic approach when computing evolutionarily stable mate-choice strategies, especially when strategies are allowed to be complex time-dependent preference rules. For simplicity and clarity our analysis deals with haploid mate-choice genetics and a male trait that is inherited phenotypically, for example by vertical cultural transmission. The method is, however, easily extendible to other cases. An example illustrates that the sexy son phenomenon can occur when there is phenotypic inheritance of the male trait. PMID:14561306

Obesogens and male fertility.

PubMed

Cardoso, A M; Alves, M G; Mathur, P P; Oliveira, P F; Cavaco, J E; Rato, L

2017-01-01

In the last decades, several studies evidenced a decrease in male fertility in developed countries. Although the aetiology of this trend in male reproductive health remains a matter of debate, environmental compounds that predispose to weight gain, namely obesogens, are appointed as contributors because of their action as endocrine disruptors. Obesogens favour adipogenesis by an imbalance of metabolic processes and can be found virtually everywhere. These compounds easily accumulate in tissues with high lipid content. Obesogens change the functioning of male reproductive axis, and, consequently, the testicular physiology and metabolism that are pivotal for spermatogenesis. The disruption of these tightly regulated metabolic pathways leads to adverse reproductive outcomes. Notably, adverse effects of obesogens may also promote disturbances in the metabolic performance of the following generations, through epigenetic modifications passed by male gametes. Thus, unveiling the molecular pathways by which obesogens induce toxicity that may end up in epigenetic modifications is imperative. Otherwise, a transgenerational susceptibility to metabolic diseases may be favoured. We present an up-to-date overview of the impact of obesogens on testicular physiology, with a particular focus on testicular metabolism. We also address the effects of obesogens on male reproductive parameters and the subsequent consequences for male fertility. © 2016 World Obesity Federation.

Sperm competition games: a general model for precopulatory male-male competition.

PubMed

Parker, Geoff A; Lessells, Catherine M; Simmons, Leigh W

2013-01-01

Reproductive males face a trade-off between expenditure on precopulatory male-male competition--increasing the number of females that they secure as mates--and sperm competition--increasing their fertilization success with those females. Previous sperm allocation models have focused on scramble competition in which males compete by searching for mates and the number of matings rises linearly with precopulatory expenditure. However, recent studies have emphasized contest competition involving precopulatory expenditure on armaments, where winning contests may be highly dependent on marginal increases in relative armament level. Here, we develop a general model of sperm allocation that allows us to examine the effect of all forms of precopulatory competition on sperm allocation patterns. The model predicts that sperm allocation decreases if either the "mate-competition loading,"a, or the number of males competing for each mating, M, increases. Other predictions remain unchanged from previous models: (i) expenditure per ejaculate should increase and then decrease, and (ii) total postcopulatory expenditure should increase, as the level of sperm competition increases. A negative correlation between a and M is biologically plausible, and may buffer deviations from the previous models. There is some support for our predictions from comparative analyses across dung beetle species and frog populations. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Seminal fluid enhances competitiveness of territorial males' sperm in a fish with alternative male reproductive tactics.

PubMed

Poli, Federica; Locatello, Lisa; Rasotto, Maria B

2018-05-29

The most common adaptation to sperm competition in males is represented by an increase in the sperm number and/or quality released at mating, to raise their probability of egg fertilization. However, rapidly mounting evidence highlights that seminal fluid may directly influence the competitive fertilization success of a male by affecting either own and/or rival sperm performances. In the black goby, Gobius niger , an external fertilizer with guard-sneaker mating tactics and high sperm competition level, sneaker males' ejaculates contain less seminal fluid and more sperm, that are also of better quality, than those of territorial males. However, territorial males, gain a higher paternity success inside natural nests. Here, we ask whether the seminal fluid can contribute to territorial males' reproductive success by enhancing their sperm performances and/or by decreasing those of sneaker males. Using sperm and seminal fluid manipulation and in vitro fertilization tests, we found that own seminal fluid influences the velocity and fertilization ability of sperm only in territorial males, making them as faster as those of sneakers and with similar fertilization rate. Moreover, both sneaker and territorial males' sperm remain unaffected by the seminal fluid of rival males. Thus, black goby males respond to the different level of sperm competition faced by differently allocating in sperm and non-sperm components of the ejaculate, with sneakers primarily investing in sperm of intrinsic high quality and territorial males relying on the effect of seminal fluid to increase the lower intrinsic quality of their sperm. © 2018. Published by The Company of Biologists Ltd.

Could Circumcision of HIV-Positive Males Benefit Voluntary Medical Male Circumcision Programs in Africa? Mathematical Modeling Analysis

PubMed Central

Awad, Susanne F.; Sgaier, Sema K.; Lau, Fiona K.; Mohamoud, Yousra A.; Tambatamba, Bushimbwa C.; Kripke, Katharine E.; Thomas, Anne G.; Bock, Naomi; Reed, Jason B.; Njeuhmeli, Emmanuel; Abu-Raddad, Laith J.

2017-01-01

Background The epidemiological and programmatic implications of inclusivity of HIV-positive males in voluntary medical male circumcision (VMMC) programs are uncertain. We modeled these implications using Zambia as an illustrative example. Methods and Findings We used the Age-Structured Mathematical (ASM) model to evaluate, over an intermediate horizon (2010–2025), the effectiveness (number of VMMCs needed to avert one HIV infection) of VMMC scale-up scenarios with varying proportions of HIV-positive males. The model was calibrated by fitting to HIV prevalence time trend data from 1990 to 2014. We assumed that inclusivity of HIV positive males may benefit VMMC programs by increasing VMMC uptake among higher risk males, or by circumcision reducing HIV male-to-female transmission risk. All analyses were generated assuming no further antiretroviral therapy (ART) scale-up. The number of VMMCs needed to avert one HIV infection was projected to increase from 12.2 VMMCs per HIV infection averted, in a program that circumcises only HIV-negative males, to 14.0, in a program that includes HIV-positive males. The proportion of HIV-positive males was based on their representation in the population (e.g. 12.6% of those circumcised in 2010 would be HIV-positive based on HIV prevalence among males of 12.6% in 2010). However, if a program that only reaches out to HIV-negative males is associated with 20% lower uptake among higher-risk males, the effectiveness would be 13.2 VMMCs per infection averted. If improved inclusivity of HIV-positive males is associated with 20% higher uptake among higher-risk males, the effectiveness would be 12.4. As the assumed VMMC efficacy against male-to-female HIV transmission was increased from 0% to 20% and 46%, the effectiveness of circumcising regardless of HIV status improved from 14.0 to 11.5 and 9.1, respectively. The reduction in the HIV incidence rate among females increased accordingly, from 24.7% to 34.8% and 50.4%, respectively

Could Circumcision of HIV-Positive Males Benefit Voluntary Medical Male Circumcision Programs in Africa? Mathematical Modeling Analysis.

PubMed

Awad, Susanne F; Sgaier, Sema K; Lau, Fiona K; Mohamoud, Yousra A; Tambatamba, Bushimbwa C; Kripke, Katharine E; Thomas, Anne G; Bock, Naomi; Reed, Jason B; Njeuhmeli, Emmanuel; Abu-Raddad, Laith J

2017-01-01

The epidemiological and programmatic implications of inclusivity of HIV-positive males in voluntary medical male circumcision (VMMC) programs are uncertain. We modeled these implications using Zambia as an illustrative example. We used the Age-Structured Mathematical (ASM) model to evaluate, over an intermediate horizon (2010-2025), the effectiveness (number of VMMCs needed to avert one HIV infection) of VMMC scale-up scenarios with varying proportions of HIV-positive males. The model was calibrated by fitting to HIV prevalence time trend data from 1990 to 2014. We assumed that inclusivity of HIV positive males may benefit VMMC programs by increasing VMMC uptake among higher risk males, or by circumcision reducing HIV male-to-female transmission risk. All analyses were generated assuming no further antiretroviral therapy (ART) scale-up. The number of VMMCs needed to avert one HIV infection was projected to increase from 12.2 VMMCs per HIV infection averted, in a program that circumcises only HIV-negative males, to 14.0, in a program that includes HIV-positive males. The proportion of HIV-positive males was based on their representation in the population (e.g. 12.6% of those circumcised in 2010 would be HIV-positive based on HIV prevalence among males of 12.6% in 2010). However, if a program that only reaches out to HIV-negative males is associated with 20% lower uptake among higher-risk males, the effectiveness would be 13.2 VMMCs per infection averted. If improved inclusivity of HIV-positive males is associated with 20% higher uptake among higher-risk males, the effectiveness would be 12.4. As the assumed VMMC efficacy against male-to-female HIV transmission was increased from 0% to 20% and 46%, the effectiveness of circumcising regardless of HIV status improved from 14.0 to 11.5 and 9.1, respectively. The reduction in the HIV incidence rate among females increased accordingly, from 24.7% to 34.8% and 50.4%, respectively. Improving inclusivity of males in VMMC

Male Reproductive System (For Teens)

MedlinePlus

... genes come from the father's sperm and the mother's egg, which are produced by the male and female reproductive systems. What Is the Male Reproductive System? Most species have two sexes: male and female. Each sex has its own ...

Assessment of Male Reproductive Toxicity##

EPA Science Inventory

This review covers all aspects of male reproductive toxicology. It begins with an overview of male reproductive biology and then transitions to the considerations of conducting male reproductive toxicology studies. We discuss multigenerational study as proposed in EPAs harmoniz...

Increased Male-Male Mounting Behaviour in Desert Locusts during Infection with an Entomopathogenic Fungus.

PubMed

Clancy, Lisa M; Cooper, Amy L; Griffith, Gareth W; Santer, Roger D

2017-07-18

Same-sex sexual behaviour occurs across diverse animal taxa, but adaptive explanations can be difficult to determine. Here we investigate male-male mounting (MMM) behaviour in female-deprived desert locust males infected with the entomopathogenic fungus Metarhizium acridum. Over a four-week period, infected locusts performed more MMM behaviours than healthy controls. Among infected locusts, the probability of MMM, and the duration of time spent MMM, significantly increased with the mounting locust's proximity to death. In experimental trials, infected locusts were also significantly more likely than controls to attempt to mount healthy males. Therefore, we demonstrate that MMM is more frequent among infected than healthy male locusts, and propose that this may be explained by terminal reproductive effort and a lowered mate acceptance threshold in infected males. However, during experimental trials mounting attempts were more likely to be successful if the mounted locusts were experimentally manipulated to have a reduced capacity to escape. Thus, reduced escape capability resulting from infection may also contribute to the higher frequency of MMM among infected male locusts. Our data demonstrate that pathogen infection can affect same-sex sexual behaviour, and suggest that the impact of such behaviours on host and pathogen fitness will be a novel focus for future research.

[Lobular breast cancer in males].

PubMed

Akimov, O V

1992-01-01

Mammary carcinoma occurs in males about 100 times more seldom than in females. 1/30 of all mammary carcinoma in males is lobular cancer. One such observation of lobular carcinoma in a male of 58 developing against the background of fibroadenomatosis is described.

Rival male chemical cues evoke changes in male pre- and post-copulatory investment in a flour beetle

PubMed Central

Lane, Sarah M.; Solino, Joanna H.; Mitchell, Christopher; Blount, Jonathan D.; Okada, Kensuke; Hunt, John

2015-01-01

Males can gather information on the risk and intensity of sperm competition from their social environment. Recent studies have implicated chemosensory cues, for instance cuticular hydrocarbons (CHCs) in insects, as a key source of this information. Here, using the broad-horned flour beetle (Gnatocerus cornutus), we investigated the importance of contact-derived rival male CHCs in informing male perception of sperm competition risk and intensity. We experimentally perfumed virgin females with male CHCs via direct intersexual contact and measured male pre- and post-copulatory investment in response to this manipulation. Using chemical analysis, we verified that this treatment engendered changes to perfumed female CHC profiles, but did not make perfumed females “smell” mated. Despite this, males responded to these chemical changes. Males increased courtship effort under low levels of perceived competition (from 1–3 rivals), but significantly decreased courtship effort as perceived competition rose (from 3–5 rivals). Furthermore, our measurement of ejaculate investment showed that males allocated significantly more sperm to perfumed females than to control females. Together, these results suggest that changes in female chemical profile elicited by contact with rival males do not provide males with information on female mating status, but rather inform males of the presence of rivals within the population and thus provide a means for males to indirectly assess the risk of sperm competition. PMID:26167098

Sneaker “jack” males outcompete dominant “hooknose” males under sperm competition in Chinook salmon (Oncorhynchus tshawytscha)

PubMed Central

Young, Brent; Conti, David V; Dean, Matthew D

2013-01-01

In a variety of taxa, males deploy alternative reproductive tactics to secure fertilizations. In many species, small “sneaker” males attempt to steal fertilizations while avoiding encounters with larger, more aggressive, dominant males. Sneaker males usually face a number of disadvantages, including reduced access to females and the higher likelihood that upon ejaculation, their sperm face competition from other males. Nevertheless, sneaker males represent an evolutionarily stable strategy under a wide range of conditions. Game theory suggests that sneaker males compensate for these disadvantages by investing disproportionately in spermatogenesis, by producing more sperm per unit body mass (the “fair raffle”) and/or by producing higher quality sperm (the “loaded raffle”). Here, we test these models by competing sperm from sneaker “jack” males against sperm from dominant “hooknose” males in Chinook salmon. Using two complementary approaches, we reject the fair raffle in favor of the loaded raffle and estimate that jack males were ∼1.35 times as likely as hooknose males to fertilize eggs under controlled competitive conditions. Interestingly, the direction and magnitude of this skew in paternity shifted according to individual female egg donors, suggesting cryptic female choice could moderate the outcomes of sperm competition in this externally fertilizing species. PMID:24455130

Male pattern baldness (image)

MedlinePlus

Male pattern baldness is a sex-linked characteristic that is passed from mother to child. A man can more accurately predict his chances of developing male pattern baldness by observing his mother's father than ...

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.

Male Weaponry in a Fighting Cricket

PubMed Central

Judge, Kevin A.; Bonanno, Vanessa L.

2008-01-01

Sexually selected male weaponry is widespread in nature. Despite being model systems for the study of male aggression in Western science and for cricket fights in Chinese culture, field crickets (Orthoptera, Gryllidae, Gryllinae) are not known to possess sexually dimorphic weaponry. In a wild population of the fall field cricket, Gryllus pennsylvanicus, we report sexual dimorphism in head size as well as the size of mouthparts, both of which are used when aggressive contests between males escalate to physical combat. Male G. pennsylvanicus have larger heads, maxillae and mandibles than females when controlling for pronotum length. We conducted two experiments to test the hypothesis that relatively larger weaponry conveys an advantage to males in aggressive contests. Pairs of males were selected for differences in head size and consequently were different in the size of maxillae and mandibles. In the first experiment, males were closely matched for body size (pronotum length), and in the second, they were matched for body mass. Males with proportionately larger weaponry won more fights and increasing differences in weaponry size between males increased the fighting success of the male with the larger weaponry. This was particularly true when contests escalated to grappling, the most intense level of aggression. However, neither contest duration nor intensity was related to weaponry size as predicted by models of contest settlement. These results are the first evidence that the size of the head capsule and mouthparts are under positive selection via male-male competition in field crickets, and validate 800-year-old Chinese traditional knowledge. PMID:19107188

Effect of mating activity and dominance rank on male masturbation among free-ranging male rhesus macaques

PubMed Central

Dubuc, Constance; Coyne, Sean P.; Maestripieri, Dario

2013-01-01

The adaptive function of male masturbation is still poorly understood, despite its high prevalence in humans and other animals. In non-human primates, male masturbation is most frequent among anthropoid monkeys and apes living in multimale-multifemale groups with a promiscuous mating system. In these species, male masturbation may be a non-functional by-product of high sexual arousal or be adaptive by providing advantages in terms of sperm competition or by decreasing the risk of sexually transmitted infections. We investigated the possible functional significance of male masturbation using behavioral data collected on 21 free-ranging male rhesus macaques (Macaca mulatta) at the peak of the mating season. We found some evidence that masturbation is linked to low mating opportunities: regardless of rank, males were most likely to be observed masturbating on days in which they were not observed mating, and lower-ranking males mated less and tended to masturbate more frequently than higher-ranking males. These results echo the findings obtained for two other species of macaques, but contrast those obtained in red colobus monkeys (Procolobus badius) and Cape ground squirrels (Xerus inauris). Interestingly, however, male masturbation events ended with ejaculation in only 15% of the observed masturbation time, suggesting that new hypotheses are needed to explain masturbation in this species. More studies are needed to establish whether male masturbation is adaptive and whether it serves similar or different functions in different sexually promiscuous species. PMID:24187414

Effect of mating activity and dominance rank on male masturbation among free-ranging male rhesus macaques.

PubMed

Dubuc, Constance; Coyne, Sean P; Maestripieri, Dario

2013-11-01

The adaptive function of male masturbation is still poorly understood, despite its high prevalence in humans and other animals. In non-human primates, male masturbation is most frequent among anthropoid monkeys and apes living in multimale-multifemale groups with a promiscuous mating system. In these species, male masturbation may be a non-functional by-product of high sexual arousal or be adaptive by providing advantages in terms of sperm competition or by decreasing the risk of sexually transmitted infections. We investigated the possible functional significance of male masturbation using behavioral data collected on 21 free-ranging male rhesus macaques ( Macaca mulatta ) at the peak of the mating season. We found some evidence that masturbation is linked to low mating opportunities: regardless of rank, males were most likely to be observed masturbating on days in which they were not observed mating, and lower-ranking males mated less and tended to masturbate more frequently than higher-ranking males. These results echo the findings obtained for two other species of macaques, but contrast those obtained in red colobus monkeys ( Procolobus badius ) and Cape ground squirrels ( Xerus inauris ). Interestingly, however, male masturbation events ended with ejaculation in only 15% of the observed masturbation time, suggesting that new hypotheses are needed to explain masturbation in this species. More studies are needed to establish whether male masturbation is adaptive and whether it serves similar or different functions in different sexually promiscuous species.

French MALE UAV Program

DTIC Science & Technology

2003-09-02

ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) MoD- France 8...1French Air Force MINISTÈRE DE LA DÉFENSE 1 SIDM CONOPS 2 FAF IMAGERY ARCHITECTURE 3 FUTURE FRENCH MALE UAV PROGRAM FRENCH MALE UAV PROGRAM Report...2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE French Male UAV Program 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

Visual perception of male body attractiveness.

PubMed

Fan, J; Dai, W; Liu, F; Wu, J

2005-02-07

Based on 69 scanned Chinese male subjects and 25 Caucasian male subjects, the present study showed that the volume height index (VHI) is the most important visual cue to male body attractiveness of young Chinese viewers among the many body parameters examined in the study. VHI alone can explain ca. 73% of the variance of male body attractiveness ratings. The effect of VHI can be fitted with two half bell-shaped exponential curves with an optimal VHI at 17.6 l m(-2) and 18.0 l m(-2) for female raters and male raters, respectively. In addition to VHI, other body parameters or ratios can have small, but significant effects on male body attractiveness. Body proportions associated with fitness will enhance male body attractiveness. It was also found that there is an optimal waist-to-hip ratio (WHR) at 0.8 and deviations from this optimal WHR reduce male body attractiveness.

Male scent-marking pheromone of Bombus ardens ardens (Hymenoptera; Apidae) attracts both conspecific queens and males

NASA Astrophysics Data System (ADS)

Kubo, Ryohei; Harano, Ken-ichi; Ono, Masato

2017-10-01

To explore the role of the volatiles emitted from male labial gland (LG) of the bumblebee Bombus ardens ardens, we investigated the responses of virgin queens and males to volatiles using a gas chromatography-electroantennographic detector (GC-EAD) system and Y-tube olfactometer. GC-EAD analysis revealed that citronellol, the main compound detected in the male LG, caused clear electrophysiological responses in the antennae of B. a. ardens virgin queens and males although two minor compounds elicited antennal responses when applied in a high concentration. Behavioral tests using a Y-tube olfactometer showed that queens and males were significantly attracted to both LG extracts and citronellol more than to the solvent alone. This is the first study to demonstrate that citronellol as a major compound of male scent-marking pheromone in B. a. ardens functions as a sex attractant for queens. The results also suggest that this compound has another function as a trail marker used by males.

Sexy males and choosy females on exploded leks: correlates of male attractiveness in the Little Bustard.

PubMed

Jiguet, Frédéric; Bretagnolle, Vincent

2014-03-01

In their choice of mates, females may use alternative tactics, including a comparative assessment of males in a population, using one or several relative preference criteria. Traits involved in female choice should presumably be variable between, but not within males, thus potentially providing reliable cues of male identity and quality for prospecting females. In lekking species, sexual selection is usually intense, and females can freely choose mates. Studying the Little Bustard Tetrax tetrax, a bird with an exploded lek mating system, we first identified male phenotypic traits that showed higher among, than within variation (plumage pattern, display rates and call structure). Among those and other traits (ornaments and their symmetry, body condition, lek spatial organization and territory quality), we identified phenotypic traits that correlated with male attractiveness toward females. At least four phenotypic male traits were correlated with female attraction, i.e. body condition, lek attendance, ornamental symmetry and display rates. Traits related to the initial female attraction on male territory seem to differ from traits related to the decision of females to stay in the territory of attractive males. Copyright © 2014 Elsevier B.V. All rights reserved.

Review of bulimia nervosa in males.

PubMed

Carlat, D J; Camargo, C A

1991-07-01

The authors describe the distribution of bulimia nervosa among males and identify characteristics that distinguish male bulimics from their female counterparts. Potential references were identified through an English-language literature search using MEDLINE (1966 to April 1990) and through extensive manual searching of textbooks and reviews. All published works with original data or hypotheses concerning bulimia in males were included. Bulimia affects approximately 0.2% of adolescent boys and young adult men, and males account for 10%-15% of all bulimic subjects identified in community-based studies. Compared to their female counterparts, male bulimics appear to have a later age of onset; higher prevalences of premorbid obesity, homosexuality, and asexuality; and less concern with strict weight control. These findings are discussed from biological, psychological, and cultural perspectives to develop a fuller understanding of the pathogenesis of bulimia in males. Bulimia in males has received relatively little attention in the literature. Future research should focus on more rigorous analytic studies that include matched comparison groups of female bulimic and male nonbulimic subjects. Such studies would not only benefit male bulimics but might provide insight into the nature of bulimia in both sexes.

[Osteopontin and male reproduction].

PubMed

Liu, Qian; Xie, Qing-Zhen

2012-05-01

Osteopontin (OPN) is an extracellular matrix protein with multifunctions, expressed in various tissues and body fluids, involved in various physiological and pathological processes. It is also detected in the reproductive tract of both males and females, and participates in the implantation, development and differentiation of embryos. Recent studies have indicated that OPN is closely related with male fertility and may affect sperm quality and fertilization. An insight into the functions of OPN may help to explain the mechanisms of male infertility and improve the success rate of assisted reproductive technology.

Nuclear-cytoplasmic male-sterility in diploid dandelions.

PubMed

van der Hulst, R G M; Meirmans, P; van Tienderen, P H; van Damme, J M M

2004-07-01

Male-sterility was found in diploid dandelions from two widely separated populations from France, and its inheritance was analysed by crossing a diploid male-sterile dandelion to diploid sexuals and triploid apomicts. Nuclear genetic variation, found in full-sib families, segregated for male-fertility, partial male-sterility, and full male-sterility, and also segregated for small-sized versus normally sized pollen. The crossing results are best explained by a cytoplasmic male-sterility factor in combination with two dominant restorer genes. Involvement of the cytoplasmic male-sterility factor was further investigated by chloroplast haplotyping. Male-sterility was exclusively associated with a rare chloroplast haplotype (designated 16b). This haplotype was found in seven male-sterile plants and one (apparently restored) male-fertile individual but does not occur in 110 co-existing male-fertile plants and not in several hundreds of individuals previously haplotyped. Apomicts with cytoplasmic male sterility were generated in some test crosses. This raises the question as to whether the male sterility found in natural dandelion apomicts, is of cytoplasmic or of nuclear genetic nature. As many breeding systems in Taraxacum are involved in shaping population structure, it will be difficult to predict the evolutionary consequences of nuclear-cytoplasmic male-sterility for this species complex.

Ovipositional response elicited by normal, irradiated, F$sub 1$ male progeny, or castrated male Trichoplusia ni (Lepidoptera: Noctuidae)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karpenko, C.P.; North, D.T.

1973-11-01

The ovipositional response of untreated Trichoplusia ni (Hubner) females that had mated to unirradiated, irradiated, F/sub 1/ male progeny from irradiated males, or castrated males was studied. Females that mated with irradiated males or F/sub 1/ sons of irradiated males oviposited fewer eggs than females that mated with control males, when all females had received a normal quantity of eupyrene and apyrene sperm. Irradiated males and F/sub 1/ sons of irradiated males that transferred an apparently normal sperm complement elicited significantly better oviposition from untreated females than did treated males that transferred mostly apyrene sperm, apyrene sperm only, or nomore » sperm. Males in the latter categories elicited a better ovipositional response from the untreated females than was observed in virgin females. Normal eupyrene sperm and possibly at least 1 accessory fiuid are required to initiate a completely normal ovipositional response in cabbage looper females. The accessory secretion triggers a significant increase in oviposition, but the greatest increase occurs when males contribute normal amounts of eupyrene sperm. The initiation of oviposition and female receptivity may be closely related in this species. (auth)« less

[Inheritance of reversions to male fertility in male-sterile sorghum hybrids with 9E cytoplasm male sterility induced by environmental conditions].

PubMed

Elkonin, L A; Gerashchenkov, G A; Domanina, I V; Rozhnova, N A

2015-03-01

Heritable phenotypic alterations occurring during plant ontogenesis under the influence of environmental factors are among the most intriguing genetic phenomena. It was found that male-sterile sorghum hybrids in the 9E cytoplasm from the F1 and F2 generations, which were obtained by crossing CMS lines with different fertile lines grown in field conditions, were transferred to greenhouse produce fertile tillers. Lines created by the self-pollination of revertant tillers exhibit complete male fertility upon cultivation under various environments (in the field, Tdry plot,(y) Tirrigated plot(y)). In a number of test-crosses of revertants to CMS lines in the 9E cytoplasm, restoration of male fertility in F1 hybrids was found, indicating that revertants possess functional fertility-restoring genes. A high positive correlation was found between the fertility level of the test-cross hybrids and the hydrothermal coefficient (the ratio of the sum of precipitation to the sum of temperatures) during the booting stage and pollen maturation (r = 0.75...0.91; P<0.01), suggesting that a high level of plant water availability is needed for the expression of fertility-restoring genes of revertants. These data show that the fertility-restoring genes for the 9E cytoplasm are dominant in conditions of high water availability and recessive in drought conditions; reversions to male fertility are due to up-regulation of fertility-restoring genes by a high level of water availability. Comparative MSAP-analysis of DNA of male-sterile and male-fertile test-cross hybrids using HpaII/MspI restrictases and primers to polygalacturonase gene ADPG2, which is required for cell separation during reproductive development, and gene MYB46, the transcription factor regulating secondary wall biosynthesis, revealed differences in the number and the length of amplified fragments. Changes in the methylation of these genes in conditions of drought stress are apparently the reason for male sterility of

Let's Hear It from the Males: Issues Facing Male Primary School Teachers

ERIC Educational Resources Information Center

Cushman, P.

2005-01-01

As the number of male teachers in primary schools continues to decrease, the resultant gender imbalance has become the focus of increased discussion and debate. While the reasons for the decline in the number of males enrolling in teacher education are complex and multi-faceted, four factors which have been identified as contributing to the…

Turn it off! the effects of exposure to male-male erotic imagery on heterosexuals' attitudes toward gay men.

PubMed

Golom, Frank D; Mohr, Jonathan J

2011-01-01

Despite the recent proliferation of lesbian, gay, and bisexual (LGB) thematic content in U.S. media, there have been relatively few empirical investigations examining its impact on heterosexuals' attitudes toward LGB individuals. This study examined the effect of one type of content, male-male homoerotic imagery, on male and female heterosexuals' attitudes toward, stereotypes about, and affective reactions to gay men. One hundred ninety-eight undergraduate students were assigned to either a male-male or male-female erotica condition, and their corresponding attitudes toward gay men were assessed. Results revealed that the effect of erotic imagery (male-male vs. male-female) on participants' stereotype and affect scores differed for men and women at varying levels of sexual anxiety. The implications of these findings are discussed in light of the literature on exposure to erotic imagery and attitudes toward gay men. In particular, the study highlights the need for additional research that acknowledges within-gender heterogeneity with respect to antigay attitude valence, extremity, and function.

Lethal fighting in nematodes is dependent on developmental pathway: male-male fighting in the entomopathogenic nematode Steinernema longicaudum.

PubMed

Zenner, Annemie N R L; O'Callaghan, Kathryn M; Griffin, Christine T

2014-01-01

Aggressive encounters occur between competitors (particularly males) throughout the animal kingdom, and in some species can result in severe injury and death. Here we describe for the first time lethal interactions between male nematodes and provide evidence that the expression of this behaviour is developmentally controlled. Males of the entomopathogenic nematode Steinernema longicaudum coil around each other, resulting in injuries, paralysis and frequently death. The probability of death occurring between pairs of males was affected by the developmental pathway followed, being much greater among males that had passed through the infective juvenile (IJ, or dauer) stage than among males that had not. Post-IJ males are found only in newly colonised hosts, typically with few competing males present. Killing those few competitors may secure valuable resources (both females and a host cadaver for nourishment of offspring). Non-IJ males develop in subsequent generations within a host cadaver, where the presence of many closely related male competitors increases the risk:benefit ratio of fighting. Thus, passage through the IJ stage primes males for enhanced aggression in circumstances where this is more likely to result in increased reproductive success. Fighting occurred between males developing in mixed-sex social groups, indicating that it is an evolved trait and not an abnormal response to absence of females. This is supported by finding high mortality of males, but not of females, across a range of population densities in insect cadavers. We propose that these nematodes, with their relatively simple organization, may be a useful model for studies of aggression.

Experience-Dependent Plasticity in Accessory Olfactory Bulb Interneurons following Male-Male Social Interaction.

PubMed

Cansler, Hillary L; Maksimova, Marina A; Meeks, Julian P

2017-07-26

Chemosensory information processing in the mouse accessory olfactory system guides the expression of social behavior. After salient chemosensory encounters, the accessory olfactory bulb (AOB) experiences changes in the balance of excitation and inhibition at reciprocal synapses between mitral cells (MCs) and local interneurons. The mechanisms underlying these changes remain controversial. Moreover, it remains unclear whether MC-interneuron plasticity is unique to specific behaviors, such as mating, or whether it is a more general feature of the AOB circuit. Here, we describe targeted electrophysiological studies of AOB inhibitory internal granule cells (IGCs), many of which upregulate the immediate-early gene Arc after male-male social experience. Following the resident-intruder paradigm, Arc -expressing IGCs in acute AOB slices from resident males displayed stronger excitation than nonexpressing neighbors when sensory inputs were stimulated. The increased excitability of Arc -expressing IGCs was not correlated with changes in the strength or number of excitatory synapses with MCs but was instead associated with increased intrinsic excitability and decreased HCN channel-mediated I H currents. Consistent with increased inhibition by IGCs, MCs responded to sensory input stimulation with decreased depolarization and spiking following resident-intruder encounters. These results reveal that nonmating behaviors drive AOB inhibitory plasticity and indicate that increased MC inhibition involves intrinsic excitability changes in Arc -expressing interneurons. SIGNIFICANCE STATEMENT The accessory olfactory bulb (AOB) is a site of experience-dependent plasticity between excitatory mitral cells (MCs) and inhibitory internal granule cells (IGCs), but the physiological mechanisms and behavioral conditions driving this plasticity remain unclear. Here, we report studies of AOB neuronal plasticity following male-male social chemosensory encounters. We show that the plasticity

Rogue Males? Approaches to Study and Academic Performance of Male Psychology Students

ERIC Educational Resources Information Center

Sanders, Lalage; Sander, Paul; Mercer, Jenny

2009-01-01

This three-year longitudinal study explored the approach to study and academic performance of a group of male psychology undergraduates. In induction week, 112 new psychology students completed the survey. Later in the year, some of the males were interviewed in small groups. Performance was measured from marks at the end of Years 1 and 3. In Year…

Male sex steroids and hormonal control of male courtship behavior in the yellow-bellied slider turtle, Trachemys scripta

USGS Publications Warehouse

Garstka, W.R.; Cooper, W.E.; Wasmund, K.W.; Lovich, J.E.

1991-01-01

Survey of androgens and estrogens in serum, liver and testes of male yellow-bellied slider turtles, Trachemys (= Pseudemys) scripta, a species exhibiting dissociated gametogenesis age-dependent melanism, revealed the presence of numerous androgen precursors, androgens, androgen metabolites, and estrogens in quantities varying with season, tissue, and male coloration.The most commonly found and abundant androgens in all males were dehydroepiandrosterone (DHEA) and androstenedione, which were present at significantly higher levels in testes than in serum or liver.Epitestosterone was found in the serum and liver of only melanistic males; testosterone was only rarely recovered.Behavioral testing of castrated male turtles implanted with various androgens, as well as intact and sham-operated controls, revealed that melanistic males courted more frequently than nonmelanistic males, and that exogenous testosterone was most effective in inducing courtship behavior in castrated males.

Condoms - male

MedlinePlus

... Rubbers; Male condoms; Contraceptive - condom; Contraception - condom; Barrier method - condom ... infections.) Latex rubber Polyurethane Condoms are the only method of birth control for men that are not ...

Short amplexus duration in a territorial anuran: a possible adaptation in response to male-male competition.

PubMed

Chuang, Ming-Feng; Bee, Mark A; Kam, Yeong-Choy

2013-01-01

Mating duration is a reproductive behaviour that can impact fertilization efficiency and offspring number. Previous studies of factors influencing the evolution of mating duration have focused on the potential role of internal sperm competition as an underlying source of selection; most of these studies have been on invertebrates. For vertebrates with external fertilization, such as fishes and frogs, the sources of selection acting on mating duration remain largely unknown due, in part, to the difficulty of observing complete mating behaviours in natural conditions. In this field study, we monitored breeding activity in a population of the territorial olive frog, Rana adenopleura, to identify factors that affect the duration of amplexus. Compared with most other frogs, amplexus was short, lasting less than 11 min on average, which included about 8 min of pre-oviposition activity followed by 3 min of oviposition. We evaluated the relationship between amplexus duration and seven variables: male body size, male condition, operational sex ratio (OSR), population size, clutch size, territory size, and the coverage of submerged vegetation in a male's territory. We also investigated the influence of these same variables, along with amplexus duration, on fertilization rate. Amplexus duration was positively related with clutch size and the degree of male-bias in the nightly OSR. Fertilization rate was directly related to male body size and inversely related to amplexus duration. Agonistic interactions between males in amplexus and intruding, unpaired males were frequent. These interactions often resulted in mating failure, prolonged amplexus duration, and reduced fertilization rates. Together, the pattern of our findings indicates short amplexus duration in this species may be an adaptive reproductive strategy whereby males attempt to reduce the risks of mating and fertilization failures and territory loss resulting from male-male competition.

Hybrid male sterility between Drosophila willistoni species is caused by male failure to transfer sperm during copulation.

PubMed

Civetta, Alberto; Gaudreau, Chelsea

2015-05-01

The biological concept of species stresses the importance of understanding what mechanisms maintain species reproductively isolated from each other. Often such mechanisms are divided into premating and postmating, with the latest being the result of either prezygotic or postzygotic isolation barriers. Drosophila willistoni quechua and Drosophila willistoni willistoni are two subspecies that experience reproductive isolation. When a D. w. quechua female is crossed with a D. w. willistoni male, the hybrid males (F1QW) are unable to father progeny; however, the reciprocal cross produces fertile hybrids. Thus, the mechanism of isolation is unidirectional hybrid male sterility. However, the sterile F1QW males contain large amounts of motile sperm. Here we explore whether pre-copulatory or post-copulatory pre-zygotic mechanisms serve as major deterrents in the ability of F1QW males to father progeny. Comparisons of parental and hybrid males copulation durations showed no significant reduction in copulation duration of F1QW males. Interrupted copulations of the parental species confirmed that sperm transfer occurs before the minimum copulation duration registered for F1QW males. However, we found that when females mate with F1QW males, sperm is not present inside the female storage organs and that the lack of sperm in storage is due to failure to transfer sperm rather than spillage or active sperm dumping by females. Sterility of F1QW hybrid males is primarily driven by their inability to transfer sperm during copulation.

Impact of inflammation on male fertility.

PubMed

Sarkar, Oli; Bahrainwala, Jamila; Chandrasekaran, Sambamurthy; Kothari, Shiva; Mathur, Premendu P; Agarwal, Ashok

2011-01-01

The male uro-genital tract is susceptible to gram-negative bacterial infections that produce a state of inflammation, particularly in the testis and epididymis. Development of germline stem cells into motile spermatozoa takes place in these organs and thus any impairment therein has a direct effect on male fertility. A number of factors are known to impair male fertility including environmental and chemical factors, lifestyle, and infections. The last is a little-known and poorly understood cause of male sub-/infertility. The presence of the pro-inflammatory cytokines like tumor necrosis factor-alpha (TNF- alpha), interleukin-1alpha (IL-1alpha) and interleukin-1beta (IL-1beta) in the male uro-genital tract following bacterial infections suggests that such infections could have cytokine-mediated anti-fertility effects. Furthermore, inflammation has been associated with elevated levels of reactive oxygen species and oxidative stress both of which affect male fertility. The present article summarizes the effects of inflammation on the testis, epididymis and spermatozoa. We review the correlations between inflammation and oxidative stress vis-à-vis spermatogenesis and discuss the implications of infections on male fertility/infertility and assisted reproductive technologies for the male.

Male Adolescent Contraceptive Utilization.

ERIC Educational Resources Information Center

Finkel, Madelon Lubin; Finkel, David J.

1978-01-01

The contraceptive utilization of a sample of sexually active, urban, high school males (Black, Hispanic, and White) was examined by anonymous questionnaire. Contraceptive use was haphazard, but White males tended to be more effective contraceptors than the other two groups. Reasons for nonuse were also studied. (Author/SJL)

Inheritance of steroid-independent male sexual behavior in male offspring of B6D2F1 mice.

PubMed

McInnis, Christine M; Bonthuis, Paul J; Rissman, Emilie F; Park, Jin Ho

2016-04-01

The importance of gonadal steroids in modulating male sexual behavior is well established. Individual differences in male sexual behavior, independent of gonadal steroids, are prevalent across a wide range of species, including man. However, the genetic mechanisms underlying steroid-independent male sexual behavior are poorly understood. A high proportion of B6D2F1 hybrid male mice demonstrates steroid-independent male sexual behavior (identified as "maters"), providing a mouse model that opens up avenues of investigation into the mechanisms regulating male sexual behavior in the absence of gonadal hormones. Recent studies have revealed several proteins that play a significant factor in regulating steroid-independent male sexual behavior in B6D2F1 male mice, including amyloid precursor protein (APP), tau, and synaptophysin. The specific goals of our study were to determine whether steroid-independent male sexual behavior was a heritable trait by determining if it was dependent upon the behavioral phenotype of the B6D2F1 sire, and whether the differential expression of APP, tau, and synaptophysin in the medial preoptic area found in the B6D2F1 sires that did and did not mate after gonadectomy was similar to those found in their male offspring. After adult B6D2F1 male mice were bred with C57BL/6J female mice, they and their male offspring (BXB1) were orchidectomized and identified as either maters or "non-maters". A significant proportion of the BXB1 maters was sired only from B6D2F1 maters, indicating that the steroid-independent male sexual behavior behavioral phenotype of the B6D2F1 hybrid males, when crossed with C57BL/6J female mice, is inherited by their male offspring. Additionally, APP, tau, and synaptophysin were elevated in in the medial preoptic area in both the B6D2F1 and BXB1 maters relative to the B6D2F1 and BXB1 non-maters, respectively, suggesting a potential genetic mechanism for the inheritance of steroid-independent male sexual behavior. Copyright

Inheritance of steroid-independent male sexual behavior in male offspring of B6D2F1 mice

PubMed Central

McInnis, Christine M.; Bonthuis, Paul J.; Rissman, Emilie F.; Park, Jin Ho

2016-01-01

The importance of gonadal steroids in modulating male sexual behavior is well established. Individual differences in male sexual behavior, independent of gonadal steroids, are prevalent across a wide range of species, including man. However, the genetic mechanisms underlying steroid-independent male sexual behavior are poorly understood. A high proportion of B6D2F1 hybrid male mice demonstrate steroid-independent male sexual behavior (identified as “maters”), providing a mouse model that opens up avenues of investigation into the mechanisms regulating male sexual behavior in the absence of gonadal hormones. Recent studies have revealed several proteins that play a significant factor in regulating steroid-independent male sexual behavior in B6D2F1 male mice, including amyloid precursor protein (APP), tau, and synaptophysin. The specific goals of our study were to determine whether steroid-independent male sexual behavior was a heritable trait by determining if it was dependent upon the behavioral phenotype of the B6D2F1 sire, and whether the differential expression of APP, tau, and synaptophysin in the medial preoptic area found in the B6D2F1 sires that did and did not mate after gonadectomy was similar to those found in their male offspring. After adult B6D2F1 male mice were bred with C57BL/6J female mice, they and their male offspring (BXB1) were orchidectomized and identified as either maters or “non-maters.” A significant proportion of the BXB1 maters were sired only from B6D2F1 maters, indicating that the steroid-independent male sexual behavior behavioral phenotype of the B6D2F1 hybrid males, when crossed with C57BL/6J female mice, is inherited by their male offspring. Additionally, APP, tau, and synaptophysin were elevated in in the medial preoptic area in both the B6D2F1 and BXB1 maters relative to the B6D2F1 and BXB1 non-maters, respectively, suggesting a potential genetic mechanism for the inheritance of steroid-independent male sexual behavior

Pheromone evolution and sexual behavior in Drosophila are shaped by male sensory exploitation of other males.

PubMed

Ng, Soon Hwee; Shankar, Shruti; Shikichi, Yasumasa; Akasaka, Kazuaki; Mori, Kenji; Yew, Joanne Y

2014-02-25

Animals exhibit a spectacular array of traits to attract mates. Understanding the evolutionary origins of sexual features and preferences is a fundamental problem in evolutionary biology, and the mechanisms remain highly controversial. In some species, females choose mates based on direct benefits conferred by the male to the female and her offspring. Thus, female preferences are thought to originate and coevolve with male traits. In contrast, sensory exploitation occurs when expression of a male trait takes advantage of preexisting sensory biases in females. Here, we document in Drosophila a previously unidentified example of sensory exploitation of males by other males through the use of the sex pheromone CH503. We use mass spectrometry, high-performance liquid chromatography, and behavioral analysis to demonstrate that an antiaphrodisiac produced by males of the melanogaster subgroup also is effective in distant Drosophila relatives that do not express the pheromone. We further show that species that produce the pheromone have become less sensitive to the compound, illustrating that sensory adaptation occurs after sensory exploitation. Our findings provide a mechanism for the origin of a sex pheromone and show that sensory exploitation changes male sexual behavior over evolutionary time.

Male skin and ingredients relevant to male skin care.

PubMed

Draelos, Z D

2012-03-01

Male skin care needs are heavily influenced by the need to remove facial hair on a regular basis. Facial skin issues associated with poor hair removal approaches are common and include razor burn and irritation. This paper evaluates current research on shaving technology and how careful ingredient selection can contribute to male skin health. The importance of maintaining hair softness during the shave and restoring facial hydration post-shave is discussed. Data are presented on how post-shave moisturizers containing glycerine and emollients can create an environment for improved barrier function which can be further improved by incorporating specific ingredients such as niacinamide. © 2012 The Author. BJD © 2012 British Association of Dermatologists.

Fishery Induces Sperm Depletion and Reduction in Male Reproductive Potential for Crab Species under Male-Biased Harvest Strategy

PubMed Central

Pardo, Luis Miguel; Rosas, Yenifer; Fuentes, Juan Pablo; Riveros, Marcela Paz; Chaparro, Oscar Roberto

2015-01-01

Sperm depletion in males can occur when polygynous species are intensively exploited under a male-biased management strategy. In fisheries involving crabs species, the effects of this type of management on the reproductive potential is far from being understood. This study tests whether male-biased management of the principal Chilean crab fishery is able to affect the potential capacity of Metacarcinus edwardsii males to transfer sperm to females. Five localities in southern Chile, recording contrasting crab fishery landing, were selected to assess the potential of sperm depletion triggered by fishery. Seasonally, male crabs from each locality were obtained. Dry weight and histological condition of vasa deferentia and the Vaso-Somatic Index (VSI) were determined in order to use them as proxies for sperm depletion and male reproductive condition. A manipulative experiment was performed in the laboratory to estimate vasa deferentia weight and VSI from just-mated males in order to obtain a reference point for the potential effects of the fishery on sperm reserves. Sperm storage capacity is significantly affected by fisheries; during the mating season vasa deferentia from localities with low fishery intensity were heavier than those from high intensity fisheries, and these differences were even more evident in large males. Histological section showed that this disparity in vasa deferentia weight was explained principally by differences in the quantity of spermatophores rather than other seminal material. VSI was always higher in males from localities with low fishery intensity. Males from localities with high fishery intensity showed little capacity to recover sperm reserves and the VSI of these males remained below the values of the just-mated males. Detriment in the capacity of males to transfer sperm is the first step to sperm limitation in an exploited population, thus detection of sperm depletion can be an alert to introduce changes in the current management of

Promotores' perspectives on a male-to-male peer network.

PubMed

Macia, Laura; Ruiz, Hector Camilo; Boyzo, Roberto; Documet, Patricia Isabel

2016-06-01

Little documentation exists about male community health workers (promotores) networks. The experiences of promotores can provide input on how to attract, train, supervise and maintain male promotores in CHW programs. We present the experience and perspectives of promotores who participated in a male promotores network assisting Latino immigrant men in an emerging Latino community. All promotores in this community-based participatory study received payment for work 10 hours a week. We conducted qualitative interviews with all promotores starting the program, after 5 and 13 months. Three main themes emerged: 1) Men decided to become promotores to help others, yet appreciated being paid. 2) Promotores' learning experience was ongoing and was facilitated by a cooperative dynamic among them. Learning how to listen was crucial for promotores 3) Promotores experienced difficulty separating their personal lives form their role as a promotor We conclude that paying promotores facilitates the fulfillment of their drive to serve the community. Enhancing listening abilities needs to be part of promotores' training curricula. Finally, it is advisable to build a project with many opportunities for promotores and project staff to share professional and non-professional time and discuss their challenges. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Gender-disturbed males.

PubMed

Levine, S B

1993-01-01

Adolescent and adult cross-dressing or "transvestism" is the most common antecedent behavioral pattern among those who request sex reassignment surgery. Transvestites are actually a diverse group of men who differ in their gender identities, orientation, and intention. They do, however, have in common a soothing image of themselves as women. Because of this, whether cross-dressing occurs among masculine or feminine males or heterosexuals, homosexuals, bisexuals, or asexuals, or among those with paraphilia, the behavior should be considered the expression of their consciously felt femininity. The confusing differences among cross-dressing males may be explained by their diversity along three dimensions: 1) the ambition for heterosexual intercourse; 2) the natural history of their sexual arousal to female clothing; 3) their current capacity to integrate their masculine and feminine strivings into separate compartments. When cross-dressers give up all vestiges of male gender role behaviors and successfully live and work full time as women, the appropriate descriptive term for them becomes "transsexual."

Homophobia, perceived fathering, and male intimate relationships.

PubMed

Devlin, P K; Cowan, G A

1985-10-01

This study examined the relationships among homophobia, perceived fathering, and male intimacy with significant male and female best friends. A questionnaire, administered to 130 adult heterosexual males, included McDonald and Game's homophobia measure (ATHMS), eight intimacy scales, and four scales measuring subjects' recollections of their fathers' parenting styles. Correlations of ATHMS and individual intimacy scales revealed a significant relationship between homophobia and intimacy in male-male relationships. Homophobia was related to male-female intimacy on those measures which reflected subjects' perception of their female partner's sensitivity to them. Although homophobia was related to perception of the father as enforcing sex roles, none of the perceived fathering variables were directly related to intimacy with males. The findings provide evidence for a direct relationship between male homophobia and lack of intimacy in friendships between men.

Primate Socioecology: New Insights from Males

NASA Astrophysics Data System (ADS)

Kappeler, Peter M.

Primate males have only recently returned to the center stage of socioecological research. This review surveys new studies that examine variation in the behavior of adult males and their role in social evolution. It is shown that group size, composition, and social behavior are determined not only by resource distribution, predation risk, and other ecological factors, but that life history traits and social factors, especially those related to sexual coercion, can have equally profound consequences for social systems. This general point is illustrated by examining male behavior at three levels: the evolution of permanent associations between males and females, the causes and consequences of variation in the number of males between group-living species, and the determinants of social relationships within and between the sexes. Direct and indirect evidence reviewed in connection with all three questions indicates that the risk of infanticide has been a pervasive force in primate social evolution. Several areas are identified for future research on male life histories that should contribute to a better understanding of male reproductive strategies and corresponding female counterstrategies.

Non-therapeutic infant male circumcision

PubMed Central

Alkhenizan, Abdullah; Elabd, Kossay

2016-01-01

Objectives: To review the evidence of the benefits and harms of infant male circumcision, and the legal and ethical perspectives of infant male circumcision. Methods: We conducted a systematic search of the literature using PubMed, EMBASE, and the Cochrane library up to June 2015. We searched the medical law literature using the Westlaw and Lexis Library law literature resources up to June 2015. Results: Male circumcision significantly reduced the risk of urinary tract infections by 87%. It also significantly reduced transmission of human immunodeficiency virus among circumcised men by 70%. Childhood and adolescent circumcision is associated with a 66% reduction in the risk of penile cancer. Circumcision was associated with 43% reduction of human papilloma virus infection, and 58% reduction in the risk of cervical cancer among women with circumcised partners compared with women with uncircumcised partners. Male infant circumcision reduced the risk of foreskin inflammation by 68%. Conclusion: Infant male circumcision should continue to be allowed all over the world, as long as it is approved by both parents, and performed in facilities that can provide appropriate sterilization, wound care, and anesthesia. Under these conditions, the benefits of infant male circumcision outweigh the rare and generally minor potential harms of the procedure. PMID:27570848

A males only clinic session.

PubMed

Stupples, A

1980-01-01

The pressure to establish the Dunedin (New Zealand) Male Advice Clinic came from members of the Psychology Department of the University of Otago as a result of a study of attitudes towards the use and purchase of contraceptives among the local young people. The study findings and the suggestions made for the establishment of a male advice center are summarized. 3 samples were studied: a university sample (N=80); a sample of high school students (N=243); and a general population sample (N=70). The males in all samples were questioned regarding the process of purchasing contraceptives. The study findings indicated that embarrassment functioned as an impediment to obtaining contraceptive supplies. 76% of the university sample, 36% of the school sample, and 57% of the general population thought that males needed advice in choosing condoms. The male advice center would be open to anyone but designed specifically to cater to young men who anticipate or are already engaged in sexual intercourse. Services available would include contraceptive advice, contraceptive supplies, and sexual advice and counseling. Initial interest in the Dunedin Male Advice Clinic was considerable, but the question remained as to whether the group for whom the clinic was intended was really reached.

Female qualities in males: vitellogenin synthesis induced by ovary transplants into the male silkworm, Bombyx mori.

PubMed

Yang, Congwen; Lin, Ying; Shen, Guanwang; Chen, Enxiang; Wang, Yanxia; Luo, Juan; Zhang, Haiyan; Xing, Runmiao; Xia, Qingyou

2014-10-10

Female qualities in males are common in vertebrates but have not been extensively reported in insects. Vitellogenin (Vg) is highly expressed in the female fat body and is generally required for the formation of yolk proteins in the insect egg. Vg upregulation is generally regarded as a female quality in female oviparous animals. In this study, we found that Bombyx mori Vg (BmVg) is especially highly expressed in the female pupa. Downregulation of the BmVg gene in the female pupa by RNA interference (RNAi) interfered with egg formation and embryonic development, showing the importance of BmVg in these processes. So, we used BmVg as a biomarker for female qualities in the silkworm. Hematoxylin-eosin staining and immunofluorescence histochemistry showed that ovary transplants induced BmVg synthesis in the male pupa fat body. Ovaries transplanted into male silkworms produced only a few eggs with deformed yolk granules. These results suggested that the amount of BmVg in the male silkworm was insufficient for eggs to undergo complete embryonic development. After 17-beta-estradiol was used to treat male pupae and male pupal fat bodies, BmVg was upregulated in vivo and in vitro. These findings indicated that the male silkworm has innate female qualities that were induced by a transplanted ovary and 17β-estradiol. However, in silkworms, female qualities in males are not as complete as in females. Copyright © 2014 Elsevier Inc. All rights reserved.

Steinach and Young, Discoverers of the Effects of Estrogen on Male Sexual Behavior and the "Male Brain".

PubMed

Södersten, Per

2015-01-01

In the 1930s, Eugen Steinach's group found that estradiol induces lordosis in castrated rats and reduces the threshold dose of testosterone that is necessary for the induction of ejaculation, and that estradiol-treated intact rats display lordosis as well as mounting and ejaculation. The bisexual, estrogen-sensitive male had been demonstrated. Another major, albeit contrasting, discovery was made in the 1950s, when William Young's group reported that male guinea pigs and prenatally testosterone-treated female guinea pigs are relatively insensitive to estrogen when tested for lordosis as adults. Reduced estrogen sensitivity was part of the new concept of organization of the neural tissues mediating the sexual behavior of females into tissues similar to those of males. The importance of neural organization by early androgen stimulation was realized immediately and led to the discovery of a variety of sex differences in the brains of adult animals. By contrast, the importance of the metabolism of testosterone into estrogen in the male was recognized only after a delay. While the finding that males are sensitive to estrogen was based on Bernhard Zondek's discovery in 1934 that testosterone is metabolized into estrogen in males, the finding that males are insensitive to estrogen was based on the hypothesis that testosterone-male sexual behavior is the typical relationship in the male. It is suggested that this difference in theoretical framework explains the discrepancies in some of the reported results.

Male identity in mental health nursing.

PubMed

Holyoake, Dean-David

To explore the cultural meaning associated with male mental health nurses. An ethnographic approach was used to discover the meaning informants attach to the cultural norms, values and rules that govern their behaviour. Data were collected through participant observation and in-depth interviews with informants. Data were analysed using emerging domains and taxonomies regarding male nurse issues. This involved grouping terms, words and everyday reflections collected from the male mental health nurses. These lists of data (taxonomies) enabled the researcher to identify in-depth cultural themes about the attitudes, behaviours and symbolism typically associated with male nurses. A number of cultural themes emerged, including the notion of 'soft masculinity', which provided some insight into male nurses' experiences of working in a female-dominated workplace. A recurring theme was the need for male nurses to demonstrate gentleness and caring while maintaining a balanced sense of masculine identity.

Review on research of suppression male fertility and male contraceptive drug development by natural products.

PubMed

Bajaj, Vijay Kumar; Gupta, Radhey S

2013-08-01

Male contraceptive development in the present scenario is most viable aspect of research due to uncontrolled population growth in the world. In this respect investigators are busy to find out a safe male contraceptive drug. Researchers have started their finding for a suitable drug from natural sources because these are safe and easily acceptable for common man, most of natural sources are plants and their products. In this review 137 plants and their effects on reproduction and reproductive physiology are summarized. Some of them have intense effect on male reproductive system and do not produce any side effects. Reproductive toxicological studies are also important aspects of these kinds of researches, so it is important that drugs are safe and widely acceptable. An ideal male contraceptive can influence semen, testes, hormone level, accessory reproductive organs and general physiology of animals and produced some alterations. Many plants in this review are showing antifertility as well as antispermatogenic effects, so these may be used for further study for contraceptives development but it is important to find out the mechanism of reaction and further laboratory and clinical research on some plants are needed for final male contraceptive drug development. In conclusion this review will help for finding suitable plant products for male contraceptive clinical and laboratory studies.

Male factor infertility: a twin study.

PubMed

Cloonan, Yona K; Holt, Victoria L; Goldberg, Jack

2007-05-01

There is a considerable body of literature on the causes of female infertility, but far less is known about male factor infertility. We conducted a classical twin study to estimate the genetic influence on 12-month male factor infertility. The study used the Vietnam Era Twin (VET) Registry, which includes male twin pairs born between 1939 and 1957, and who served in the US military between 1965 and 1975. In 1987, a health survey was mailed to all twins and obtained a 74% response rate. The current analyses comprised 1795 complete pairs in which both twins were married only once. Proband-wise concordance rates, tetrachoric correlations, and a bivariate probit model were used to calculate estimates of familial clustering and heritability for male factor infertility. The proband concordance rate for male factor infertility was 38% [95% CI 32.8, 42.4] in monozygotic (MZ) pairs and 33% [95% CI 28.0, 38.6] in dizygotic (DZ) pairs. The tetrachoric correlations for male infertility were 0.15 in MZ and 0.04 in DZ pairs. This pattern provides evidence of familial clustering, although genetic influence was not evident (P = 0.21). The current study identified that 12-month male factor infertility clustered within families. However, results suggest that factors unique to individual twins may play a more prominent role in male infertility than additive genetic effects or the common environment.

Sexy faces in a male paper wasp.

PubMed

de Souza, André Rodrigues; Alberto Mourão Júnior, Carlos; do Nascimento, Fabio Santos; Lino-Neto, José

2014-01-01

Sexually selected signals are common in many animals, though little reported in social insects. We investigated the occurrence of male visual signals mediating the dominance relationships among males and female choice of sexual partner in the paper wasp Polistes simillimus. Males have three conspicuous, variable and sexually dimorphic traits: black pigmentation on the head, a pair of yellow abdominal spots and body size differences. By conducting behavioral assays, we found that none of the three visual traits are associated with male-male dominance relationship. However, males with higher proportion of black facial pigmentation and bigger yellow abdominal spots are more likely chosen as sexual partners. Also, after experimentally manipulating the proportion of black pigment on males' face, we found that females may evaluate male facial coloration during the choice of a sexual partner. Thus, the black pigmentation on P. simillimus male's head appears to play a role as a sexually selected visual signal. We suggest that sexual selection is a common force in Polistes and we highlight the importance of this group as a model for the study of visual communication in insects.

Self-Concept and Psychological Adjustment Differences Between Self-Identified Male Transexuals and Male Homosexuals

ERIC Educational Resources Information Center

Roback, Howard B.; And Others

1977-01-01

Self-concept and adjustment data from anatomical males seeking sexual reassignment surgery were compared with that from a male homosexual group. Findings indicated that the homosexual group had a better self-image and was better adjusted than the sex change group. (Author)

Males do not see only red: UV wavelengths and male territorial aggression in the three-spined stickleback ( Gasterosteus aculeatus)

NASA Astrophysics Data System (ADS)

Rick, Ingolf P.; Bakker, Theo C. M.

2008-07-01

Animal colour signals serve important functions in intraspecific interactions, including species recognition, mate choice and agonistic behaviour. An increasing interest concerns ultraviolet (UV) wavelengths, for instance studies on the effect of UV in mating decisions. More recently, some studies also established that UV signals affect intrasexual interactions. We studied the role of UV during aggressive encounters between male three-spined sticklebacks ( Gasterosteus aculeatus), a species in which UV has an effect on female and male mate choice and shoaling behaviour. To that aim, we compared the aggressive response of a territorial male to male intruders, either seen in UV-including (UV+) or UV-lacking (UV-) conditions. Our prediction was that, if UV wavelengths are used in male-male competition, a territorial male should show less competitive behaviour towards an intruder representing a lower threat, i.e. the one presented without UV light. Male sticklebacks showed significantly lower levels of aggression towards male opponents lacking an UV component to their coloration than male opponents possessing this colour component. Discrimination was not influenced by a difference in brightness between the UV+ and UV- stimuli. Finally, we present some reflectance-spectrophotometrical data of two skin regions (cheek and abdomen) of the experimental males and analysed relationships between colorimetric variables, body variables and behaviour. Our study emphasises that UV visual cues are of importance in different communicational tasks in the three-spined stickleback.

Attracting, Recruiting and Retaining Male Teachers: Policy Issues in the Male Teacher Debate

ERIC Educational Resources Information Center

Mills, Martin; Martino, Wayne; Lingard, Bob

2004-01-01

Frequent calls for more male teachers are being made in English-speaking countries. Many of these calls are based upon the fact that the teaching profession has become (even more) 'feminized' and the presumption that this has had negative effects for the education of boys. The employment of more male teachers is sometimes suggested as a way to…

Male Hypogonadism

MedlinePlus

... Erectile dysfunction Infertility Decrease in beard and body hair growth Decrease in muscle mass Development of breast tissue ( ... Enlarged male breasts (gynecomastia) Decreased beard and body hair growth Osteoporosis By Mayo Clinic Staff . Mayo Clinic Footer ...

[Male breast cancer].

PubMed

Beyrouti, Mohamed I; Kharrat Koubaa, Madiha; Affes, Najmeddine; Ben Ali, Issam; Abbes, Imed; Frikha, Mounir; Daoud, Jamel; Kechaou, Mohamed; Jlidi, Rachid

2003-01-01

This study has been realized to determine epidemiological profile and clinico-pathologic aspects of male breast cancer in the south of Tunisia. We has counted and analysed all male breast cancers diagnosed in the general surgery department of the Sfax university teaching hospital with proof pathologic or to defect cytologic of malignancy, between 1989 and 2000. In the court of these years 23 new cases of mammary cancer has been diagnosed at the man. The average patient age was 68 years (extremes 40 and 95 years). According to TNM classification of 1988, 4.3% were classified T1, 26.1% T2, 8.6% T3 and 61% T4; 22% of tumors were M1. Histology found: 3 in-situ carcinomas (13%), 18 ductular infiltrating carcinomas (79%), 1 papillary cystadenocarcinoma, and 1 neuro-endocrin tumor. The clinic profile of male breast cancer in our country rest again relatively little frequent and its clinic profile resist alarming. To get better prognosis it is important to increase information and to promote early detection.

Seasonal resource value and male size influence male aggressive interactions in the leaf footed cactus bug, Narnia femorata.

PubMed

Nolen, Zachary J; Allen, Pablo E; Miller, Christine W

2017-05-01

In animal contests, resource value (the quality of a given resource) and resource holding potential (a male's absolute fighting ability) are two important factors determining the level of engagement and outcome of contests. Few studies have tested these factors simultaneously. Here, we investigated whether natural, seasonal differences in cactus phenology (fruit quality) influence interactions between males in the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae). We also considered whether males were more likely to interact when they were similar in size, as predicted by theory. Finally, we examined if male size relative to the size of an opponent predicted competitive success. We found that males have more interactions on cactus with high value ripe fruit, as we predicted. Further, we found that males that were closer in size were more likely to interact, and larger males were more likely to become dominant. Copyright © 2017 Elsevier B.V. All rights reserved.

Sexy Faces in a Male Paper Wasp

PubMed Central

de Souza, André Rodrigues; Alberto Mourão Júnior, Carlos; Santos do Nascimento, Fabio; Lino-Neto, José

2014-01-01

Sexually selected signals are common in many animals, though little reported in social insects. We investigated the occurrence of male visual signals mediating the dominance relationships among males and female choice of sexual partner in the paper wasp Polistes simillimus. Males have three conspicuous, variable and sexually dimorphic traits: black pigmentation on the head, a pair of yellow abdominal spots and body size differences. By conducting behavioral assays, we found that none of the three visual traits are associated with male-male dominance relationship. However, males with higher proportion of black facial pigmentation and bigger yellow abdominal spots are more likely chosen as sexual partners. Also, after experimentally manipulating the proportion of black pigment on males' face, we found that females may evaluate male facial coloration during the choice of a sexual partner. Thus, the black pigmentation on P. simillimus male's head appears to play a role as a sexually selected visual signal. We suggest that sexual selection is a common force in Polistes and we highlight the importance of this group as a model for the study of visual communication in insects. PMID:24849073

African American Males Navigate Racial Microaggressions

ERIC Educational Resources Information Center

Hotchkins, Bryan K.

2016-01-01

Background/Context: High school educational environments find Black males experience systemic racial microaggressions in the form of discipline policies, academic tracking and hegemonic curriculum (Allen, Scott, & Lewis, 2013). Black males in high school are more likely than their White male peers to have high school truancies and be viewed as…

The evolution of postpairing male mate choice.

PubMed

Lyu, Nan; Servedio, Maria R; Lloyd, Huw; Sun, Yue-Hua

2017-06-01

An increasing number of empirical studies in animals have demonstrated male mate choice. However, little is known about the evolution of postpairing male choice, specifically which occurs by differential allocation of male parental care in response to female signals. We use a population genetic model to examine whether such postpairing male mate choice can evolve when males face a trade-off between parental care and extra-pair copulations (EPCs). Specifically, we assume that males allocate more effort to providing parental care when mated to preferred (signaling) females, but they are then unable to allocate additional effort to seek EPCs. We find that both male preference and female signaling can evolve in this situation, under certain conditions. First, this evolution requires a relatively large difference in parental investment between males mated to preferred versus nonpreferred females. Second, whether male choice and female signaling alleles become fixed in a population versus cycle in their frequencies depends on the additional fecundity benefits from EPCs that are gained by choosy males. Third, less costly female signals enable both signaling and choice alleles to evolve under more relaxed conditions. Our results also provide a new insight into the evolution of sexual conflict over parental care. © 2017 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

Technology, normalisation and male sex work.

PubMed

MacPhail, Catherine; Scott, John; Minichiello, Victor

2015-01-01

Technological change, particularly the growth of the Internet and smart phones, has increased the visibility of male escorts, expanded their client base and diversified the range of venues in which male sex work can take place. Specifically, the Internet has relocated some forms of male sex work away from the street and thereby increased market reach, visibility and access and the scope of sex work advertising. Using the online profiles of 257 male sex workers drawn from six of the largest websites advertising male sexual services in Australia, the role of the Internet in facilitating the normalisation of male sex work is discussed. Specifically we examine how engagement with the sex industry has been reconstituted in term of better informed consumer-seller decisions for both clients and sex workers. Rather than being seen as a 'deviant' activity, understood in terms of pathology or criminal activity, male sex work is increasingly presented as an everyday commodity in the market place. In this context, the management of risks associated with sex work has shifted from formalised social control to more informal practices conducted among online communities of clients and sex workers. We discuss the implications for health, legal and welfare responses within an empowerment paradigm.

Sexual selection on male size drives the evolution of male-biased sexual size dimorphism via the prolongation of male development.

PubMed

Rohner, Patrick T; Blanckenhorn, Wolf U; Puniamoorthy, Nalini

2016-06-01

Sexual size dimorphism (SSD) arises when the net effects of natural and sexual selection on body size differ between the sexes. Quantitative SSD variation between taxa is common, but directional intraspecific SSD reversals are rare. We combined micro- and macroevolutionary approaches to study geographic SSD variation in closely related black scavenger flies. Common garden experiments revealed stark intra- and interspecific variation: Sepsis biflexuosa is monomorphic across the Holarctic, while S. cynipsea (only in Europe) consistently exhibits female-biased SSD. Interestingly, S. neocynipsea displays contrasting SSD in Europe (females larger) and North America (males larger), a pattern opposite to the geographic reversal in SSD of S. punctum documented in a previous study. In accordance with the differential equilibrium model for the evolution of SSD, the intensity of sexual selection on male size varied between continents (weaker in Europe), whereas fecundity selection on female body size did not. Subsequent comparative analyses of 49 taxa documented at least six independent origins of male-biased SSD in Sepsidae, which is likely caused by sexual selection on male size and mediated by bimaturism. Therefore, reversals in SSD and the associated changes in larval development might be much more common and rapid and less constrained than currently assumed. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Why Do Cuckolded Males Provide Paternal Care?

PubMed Central

Griffin, Ashleigh S.; Alonzo, Suzanne H.; Cornwallis, Charlie K.

2013-01-01

In most species, males do not abandon offspring or reduce paternal care when they are cuckolded by other males. This apparent lack of adjustment of paternal investment with the likelihood of paternity presents a potential challenge to our understanding of what drives selection for paternal care. In a comparative analysis across birds, fish, mammals, and insects we identify key factors that explain why cuckolded males in many species do not reduce paternal care. Specifically, we show that cuckolded males only reduce paternal investment if both the costs of caring are relatively high and there is a high risk of cuckoldry. Under these circumstances, selection is expected to favour males that reduce paternal effort in response to cuckoldry. In many species, however, these conditions are not satisfied and tolerant males have outcompeted males that abandon young. PMID:23555193

Male-to-male sex among men who inject drugs in Delhi, India: overlapping HIV risk behaviours.

PubMed

Armstrong, Gregory; Jorm, Anthony F; Samson, Luke; Joubert, Lynette; Singh, Shalini; Kermode, Michelle

2015-04-01

HIV among people who inject drugs (PWID) is a major public health challenge in India. This paper examines PWID in Delhi who also have male-to-male sex with a focus on overlapping HIV risk behaviours and the psychosocial correlates of a history of male-to-male anal sex. We analysed data collected in April-May of 2012 from a community-based sample of 420 male PWID in Delhi obtained using time location sampling. One third (37%) of the men reported a history of anal sex with men, among whom just 16% used a condom at last anal sex. Almost all (93%) participants who had a history of anal sex with men also had sex with women. Chi-square tests revealed that a history of anal sex with men was associated with a higher number of female sexual partners and sharing of needles and syringes. Additionally, unprotected sex at last sex with a male partner was significantly associated with unprotected sex at last sex with regular and paid female partners. Multivariate binary logistic regression revealed that the psychosocial correlates of a history of anal sex with other men were: being aged 18-24 (OR = 2.4, p = 0.014), illiteracy (OR = 1.9, p = 0.033), having never been married (OR = 2.6, p = 0.007), a main source of income of crime/begging (OR = 3.1, p = 0.019), a duration of injecting drug use greater than 20 years (OR = 3.4, p = 0.035) and suicidal ideation (OR = 1.7, p = 0.048). Male-to-male sex was associated with psychosocial vulnerability, including a longer history of injecting drug use, suicidal ideation and socio-economic disadvantage. Given the extent of overlapping HIV risk behaviours, HIV programs for PWID would benefit from a strong focus on prevention of sexual HIV transmission, especially among male injectors who also have sex with other men. Copyright © 2014 Elsevier B.V. All rights reserved.

Hormonal Approaches to Male contraception

PubMed Central

Wang, Christina; Swerdloff, Ronald S.

2010-01-01

Purpose of review Condoms and vasectomy are male controlled family planning methods but suffer from limitations in compliance (condoms) and limited reversibility (vasectomy); thus many couples desire other options. Hormonal male contraceptive methods have undergone extensive clinical trials in healthy men and shown to be efficacious, reversible and appear to be safe. Recent Findings The success rate of male hormonal contraception using injectable testosterone alone is high and comparable to methods for women. Addition of progestins to androgens improved the rate of suppression of spermatogenesis. Supported by government or non-government organizations, current studies aim to find the best combination of testosterone and progestins for effective spermatogenesis suppression and to explore other delivery methods for these hormones. Translation of these advances to widespread use in the developed world will need the manufacturing and marketing skills of the pharmaceutical industry. Availability of male contraceptives to the developing world may require commitments of governmental and non-governmental agencies. In a time when imbalance of basic resources and population needs are obvious, this may prove to be a very wise investment. Summary Male hormonal contraception is efficacious, reversible and safe for the target population of younger men in stable relationships. Suppression of spermatogenesis is achieved with a combination of an androgen and a progestin. Partnership with industry will accelerate the marketing of a male hormonal contraceptive. Research is ongoing on selective androgen and progesterone receptor modulators that suppress spermatogenesis, minimize potential adverse events while retaining the androgenic actions. PMID:20808223

Hormonal approaches to male contraception.

PubMed

Wang, Christina; Swerdloff, Ronald S

2010-11-01

Condoms and vasectomy are male-controlled family planning methods but suffer from limitations in compliance (condoms) and limited reversibility (vasectomy); thus many couples desire other options. Hormonal male contraceptive methods have undergone extensive clinical trials in healthy men and shown to be efficacious, reversible and appear to be well tolerated. The success rate of male hormonal contraception using injectable testosterone alone is high and comparable to methods for women. Addition of progestins to androgens improved the rate of suppression of spermatogenesis. Supported by government or nongovernment organizations, current studies aim to find the best combination of testosterone and progestins for effective spermatogenesis suppression and to explore other delivery methods for these hormones. Translation of these advances to widespread use in the developed world will need the manufacturing and marketing skills of the pharmaceutical industry. Availability of male contraceptives to the developing world may require commitments of governmental and nongovernmental agencies. In a time when imbalance of basic resources and population needs are obvious, this may prove to be a very wise investment. Male hormonal contraception is efficacious, reversible and well tolerated for the target population of younger men in stable relationships. Suppression of spermatogenesis is achieved with a combination of an androgen and a progestin. Partnership with industry will accelerate the marketing of a male hormonal contraceptive. Research is ongoing on selective androgen and progesterone receptor modulators that suppress spermatogenesis, minimize potential adverse events while retaining the androgenic and gonadotropin suppressive actions.

Graduating Black Males: A Generic Qualitative Study

ERIC Educational Resources Information Center

Bell, Edward E.

2014-01-01

Black males face a difficult educational battle. Across America, graduation statistics for Black males are sobering. The purpose of this study was to explore why Black males drop out of school and to examine the current employment status of the study participants. The research took place in rural North Carolina. Fifteen Black American male high…

Blood-feeding of Tunga penetrans males.

PubMed

Witt, L H; Linardi, P M; Meckes, O; Schwalfenberg, S; Ribeiro, R A; Feldmeier, H; Heukelbach, J

2004-12-01

The jigger Tunga penetrans (Linnaeus, 1758: type-species of the family Tungidae) is the smallest known species of flea (Siphonaptera), causing serious ectoparasitosis of humans and domestic animals. The adult female Tunga lodges in the epidermis of the mammalian host, grows by neosomy, becomes gravid and expels eggs. Relatively little is known about the free-living male Tunga adults. Among impoverished communities of Fortaleza in north-east Brazil, we observed T. penetrans males as well as females penetrating the skin of human hosts. After penetrating the epidermis for a few hours, evidently for capillary feeding from the dermis, males withdrew their mouthparts and crawled away, whereas the females remained completely embedded, hypertrophying to become gravid, eventually dying in situ after oviposition. Caged rats were placed on the sandy soil and examined periodically for Tunga infestation. On five rats we obtained 140 females embedded and we detected 75 males biting, with rat erythrocytes observed in the proventriculus and midgut of all five males dissected and examined microscopically. This confirms that T. penetrans males are hamatophagous ectoparasites of mammals.

Where Are All the Males?: A Mixed Methods Inquiry into Male Study Abroad Participation

ERIC Educational Resources Information Center

Lucas, James M.

2009-01-01

Study abroad represents a powerful tool for internationalizing students' higher education experience; however, current participation numbers indicate that male students go on study abroad programs at half the rate of female students. This rate reflects broader engagement trends for male college students, who have fallen behind female participation…

Ultrasonography of the male breast.

PubMed

Draghi, F; Tarantino, C C; Madonia, L; Ferrozzi, G

2011-09-01

The male breast has been insufficiently explored in the medical literature, particularly that dealing with ultrasonography, although this topic is almost as vast and varied as that of the female breast. The purpose of this article is to provide a schematic review of the most frequent breast lesions encountered in males and their sonographic appearances. After a brief introduction on the anatomy of the male breast, the authors review the non-neoplastic (gynecomastia, pseudogynecomastia, cysts, inflammatory diseases, and Mondor disease) and neoplastic (benign and malignant) lesions encountered in this organ.

Ultrasonography of the male breast

PubMed Central

Draghi, F.; Tarantino, C.C.; Madonia, L.; Ferrozzi, G.

2011-01-01

The male breast has been insufficiently explored in the medical literature, particularly that dealing with ultrasonography, although this topic is almost as vast and varied as that of the female breast. The purpose of this article is to provide a schematic review of the most frequent breast lesions encountered in males and their sonographic appearances. After a brief introduction on the anatomy of the male breast, the authors review the non-neoplastic (gynecomastia, pseudogynecomastia, cysts, inflammatory diseases, and Mondor disease) and neoplastic (benign and malignant) lesions encountered in this organ. PMID:23397020

Ultrasonic Songs of Male Mice

PubMed Central

Guo, Zhongsheng

2005-01-01

Previously it was shown that male mice, when they encounter female mice or their pheromones, emit ultrasonic vocalizations with frequencies ranging over 30–110 kHz. Here, we show that these vocalizations have the characteristics of song, consisting of several different syllable types, whose temporal sequencing includes the utterance of repeated phrases. Individual males produce songs with characteristic syllabic and temporal structure. This study provides a quantitative initial description of male mouse songs, and opens the possibility of studying song production and perception in an established genetic model organism. PMID:16248680

Male swordtails court with an audience in mind.

PubMed

Fisher, Heidi S; Rosenthal, Gil G

2007-02-22

Females are usually considered to be the target of male courtship behaviour. In nature, however, social interactions rarely occur without other observers; thus, it is conceivable that some male courtship behaviours are directed not towards females, but rather towards male rivals. The northern swordtail, Xiphophorus birchmanni, is a freshwater fish found in high densities in natural streams. Males court by swimming close to and in parallel with the female, raising their large sail-like dorsal fin, and quivering briefly. Here, we show that females prefer males that display small dorsal fins to those with large ones, and that males are less aggressive to other males with large dorsal fins. Male swordtails also raise their dorsal fins more frequently when courting in the presence of other males. These results suggest that, despite female avoidance of large dorsal fins, males that raise their fin during courtship benefit by intimidating potential competitors; the intended receivers of this signal are thus males, not females. Intrasexual selection can therefore offset the forces of intersexual selection, even in a courtship display.

Attraction of Male Nymphs to Adult Male Volatiles in the Bronze Bug Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae).

PubMed

Calvo, M V; Groba, H F; Martínez, G; Sellanes, C; Rossini, C; González, A

2017-12-23

The bronze bug, Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae), is an exotic emerging pest in Eucalyptus commercial forests in South America, Africa and southern Europe. Information on the chemical communication system and reproductive ecology of this insect is scant, and it may be relevant for designing management strategies for eucalypt plantations. Adults and nymphs usually aggregate in the field, possibly by means of chemical signals. Males emit large amounts of 3-methyl-2-butenyl butyrate, which attracts conspecific adult males but not females. The ecological role of this putative male aggregation pheromone remains unknown. Here, we report olfactometer bioassays showing that late-instar male nymphs are also attracted to synthetic 3-methyl-2-butenyl butyrate and to adult male volatile extracts, which contain this compound as the major component. As previously shown for adult females, nymphs that moulted into females were not attracted to either volatile stimulus. The intra-gender attraction of nymphs and adults may be related to the exploitation of food resources, or as a reproductive strategy for newly emerged males. Further studies on the reproductive behaviour and mating system of T. peregrinus will contribute to understanding the ecological significance of male-male, adult-nymph attraction, as well as the practical applications that may result from these findings.

Sexual orientation, theory of mind and empathy: a comparison of male homosexual and male and female heterosexuals.

PubMed

Shapouri, Soheil; Nejati, Vahid; Eftekhar Ardebili, Mehrdad

2015-01-01

Researchers have been investigating similarities of and differences between homosexuals and heterosexuals for past few decades. Several studies have shown that in the particular domain (e.g., spatial ability), male homosexuals would resemble female heterosexuals better than male heterosexuals. Executive function, however, has received more attention than social cognition in this line of research. This study focuses on theory of mind and empathy as two important components of social cognition in male homosexuals (N=14), male heterosexuals (N=15) and female heterosexuals (N=14). Applying Reading the Mind in the Eyes test and the Empathy Quotient, no significant difference between groups was identified. This study suggests that similarities of male homosexuals and female heterosexuals may be confined to executive function and not extended to some social cognition abilities like theory of mind or empathy.

Sex steroid levels in XY males and sex-reversed XX males, of rainbow trout (Oncorhynchus mykiss), during the reproductive cycle.

PubMed

Espinosa, E; Josa, A; Gil, L; González, N

2011-02-01

In this study, the annual cycle of the gonadal steroids testosterone (T), 11-ketotestosterone (11-KT), 17β-oestradiol (E2) and 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) was determined using radioimmunoassay and then compared, for XY males (n=35) and sex-reversed XX males (n=27) rainbow trout, to establish possible endocrinology differences. Both in XY males and sex-reversed XX males, significant correlation was shown between body weight and T (r=0.5046 and 0.34078, respectively; p<0.0001) or KT (r=0.52494 and 0.43545, respectively; p<0.0001) concentrations. Plasma androgen levels in XY and sex-reversed XX males were similar and showed an intense seasonal variation. The highest levels for T and 11-KT were detected from December to April with a peak in January (51.67 ± 5.11 and 61.95 ± 4.25 ng/ml, for XY males and 57.1 ± 5.82 and 59.27 ± 4.84 ng/ml, respectively, for XX males). In addition, there was a positive correlation (p<0.0001) between T and 11-KT levels for XY males (r=0.7533) and sex-reversed XX males (r=0.6019). Concentrations of DHP in XY males also showed seasonal variation with a peak in February (25.18 ± 12.99 ng/ml). However, DHP levels in sex-reversed XX males were undetectable (<0.1 ng/ml) over the year. Levels of E2 were undetectable through the year in both groups of trout. In conclusion, the androgenic and oestrogenic profiles of sex-reversed XX males were similar to those observed in XY males. The only difference in the annual gonadal steroid cycle between XY and sex-reversed XX males was in the DHP profile. © 2009 Blackwell Verlag GmbH.

Neighborhood Characteristics as Predictors of Male to Female and Female to Male Partner Violence

ERIC Educational Resources Information Center

Caetano, Raul; Ramisetty-Mikler, Suhasini; Harris, T. Robert

2010-01-01

This article examines the association between neighborhood characteristics at the census tract-level, couples' perceived neighborhood social cohesion and informal social control, and male-to-female (MFPV) and female-to-male (FMPV) partner violence in the United States. Data come from a second wave of interviews (2000) with a national sample of…

Beyond the Condom: Frontiers in Male Contraception

PubMed Central

Roth, Mara Y.; Amory, John K.

2016-01-01

Nearly half of all pregnancies worldwide are unplanned, despite numerous contraceptive options available. No new contraceptive method has been developed for men since the invention of condom. Nevertheless, more than 25% of contraception worldwide relies on male methods. Therefore, novel effective methods of male contraception are of interest. Herein we review the physiologic basis for both male hormonal and nonhormonal methods of contraception. We review the history of male hormonal contraception development, current hormonal agents in development, as well as the potential risks and benefits of male hormonal contraception options for men. Nonhormonal methods reviewed will include both pharmacological and mechanical approaches in development, with specific focus on methods which inhibit the testicular retinoic acid synthesis and action. Multiple hormonal and nonhormonal methods of male contraception are in the drug development pathway, with the hope that a reversible, reliable, safe method of male contraception will be available to couples in the not too distant future. PMID:26947703

Beyond the Condom: Frontiers in Male Contraception.

PubMed

Roth, Mara Y; Amory, John K

2016-05-01

Nearly half of all pregnancies worldwide are unplanned, despite numerous contraceptive options available. No new contraceptive method has been developed for men since the invention of condom. Nevertheless, more than 25% of contraception worldwide relies on male methods. Therefore, novel effective methods of male contraception are of interest. Herein we review the physiologic basis for both male hormonal and nonhormonal methods of contraception. We review the history of male hormonal contraception development, current hormonal agents in development, as well as the potential risks and benefits of male hormonal contraception options for men. Nonhormonal methods reviewed will include both pharmacological and mechanical approaches in development, with specific focus on methods which inhibit the testicular retinoic acid synthesis and action. Multiple hormonal and nonhormonal methods of male contraception are in the drug development pathway, with the hope that a reversible, reliable, safe method of male contraception will be available to couples in the not too distant future. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A review of eating disorders in males.

PubMed

Raevuori, Anu; Keski-Rahkonen, Anna; Hoek, Hans W

2014-11-01

Research in eating disorders in males has been active lately compared to the past. This review aims to provide an overview of the recently published studies of eating disorders in males. Publication of the Diagnostic and Statistical Manual of Mental Disorders, 5th edition has outlined more sex-neutral diagnostic criteria for eating disorders. Data of socioeconomic factors, prenatal influences, clinical characteristics, assessment, and mortality for eating disorders have been reported independently for males. Unlike in females, higher parental education showed no association with eating disorders in males, but twin or triplet status and lower gestational age at birth had an independent association with anorexia nervosa in males. Contrary to earlier suggestions, no differences in eating disorder symptoms such as binging, vomiting, or laxative abuse were observed between the sexes. Yet, males tended to score lower on eating disorder symptom measures than females. High rates of premorbid overweight and higher BMIs at various stages of eating disorders have been confirmed repeatedly. Higher age and lower BMI at admission, and restrictive anorexia nervosa subtype predicted fatal outcome for anorexia nervosa in males. Contemporary research provides grounds for improved recognition, diagnosis, and treatment for males suffering from eating disorders.

Comparison of male and female foot shape.

PubMed

Luo, Gangming; Houston, Vern L; Mussman, Martin; Garbarini, Maryanne; Beattie, Aaron C; Thongpop, Chaiya

2009-01-01

Morphological and geometric differences between male and female feet can be the decisive factor of whether well-fitting, functional, and comfortable footwear is available for both men and women. Optical scans, plaster wrap casts, and a set of manual measurements from the right feet of 51 female participants, aged 20 to 59 years (32 +/- 10.2 years), and 39 male participants, aged 22 to 71 years (47.1 +/- 12.1 years), were taken to determine which parameters were the most significant in characterizing pedal geometry and which had the largest difference between male and female feet. Analysis showed that the heel-to-ball length (ball length) of the male participants' feet (181.5 mm) was significantly longer, on average, than that of the female participants' feet (165.0 mm). The width of the male paticipants' feet at the ball, instep, and heel regions, as well as the ball circumference, normalized by the ball length, were all significantly larger on average, than the female test participants' feet. However, toe region, instep, and medial and lateral malleoli heights were larger, on average, for the female participants than for the male. The results show that female feet differ in size and shape from male feet and are not algebraically scaled, smaller versions of male feet, as is often assumed. The study shows that the average male participants' feet are longer than that of the female participants' feet, while the female feet are relatively narrower but higher than those of the male participants.

Bodice Rippers without the Bodice: Ten Male-on-Male Romances for a Core Collection

ERIC Educational Resources Information Center

Thomas, Devon

2011-01-01

One of the hottest growing segments of the romance genre is male-on-male (M/M) romance--gay romantic fiction mostly written and read by straight women. Featuring traditional romance conventions, including mistaken identities, star-crossed lovers, and happy endings, these stories show both physical and emotional intimacy between men. M/M builds on…

Comparison of reproductive traits of regular and irradiated male desert locust Schistocerca gregaria (Orthoptera: Acrididae): Evidence of last-male sperm precedence

PubMed Central

Dushimirimana, Severin; Hance, Thierry; Damiens, David

2012-01-01

Summary The sterile insect technique (SIT) is increasingly used to control pest insect populations. The success of SIT control programs depends on the ability to release sterile males and on the capacity of sterile males to compete with wild males to inseminate wild females. In this study, we evaluated the mating performance of Schistocerca gregaria (Försk.) males irradiated with 4 Gray. We compared reproductive traits, such as duration of precopulation time, mating duration, quantity of sperm stored by females after copulation, number of females mated successively and postmating competition of irradiated males with non-irradiated males. Irradiated males were able to mate but the resulting number of offspring was dramatically reduced compared to the average number of offspring observed during a regular mating. During a single copulation, irradiated males transferred fewer sperm than regular males but, theoretically, this quantity is enough to fertilize all the eggs produced by a female during its reproductive life. Irradiated males also had the ability to remove sperm from a previous mating with unirraditated males. This new information on the mating strategies helps explain the post-copulation guarding behaviour of S. gregaria. PMID:23213413

Supplementation of Male Pheromone on Rock Substrates Attracts Female Rock Lizards to the Territories of Males: A Field Experiment

PubMed Central

Martín, José; López, Pilar

2012-01-01

Background Many animals produce elaborated sexual signals to attract mates, among them are common chemical sexual signals (pheromones) with an attracting function. Lizards produce chemical secretions for scent marking that may have a role in sexual selection. In the laboratory, female rock lizards (Iberolacerta cyreni) prefer the scent of males with more ergosterol in their femoral secretions. However, it is not known whether the scent-marks of male rock lizards may actually attract females to male territories in the field. Methodology/Principal Findings In the field, we added ergosterol to rocks inside the territories of male lizards, and found that this manipulation resulted in increased relative densities of females in these territories. Furthermore, a higher number of females were observed associated to males in manipulated plots, which probably increased mating opportunities for males in these areas. Conclusions/Significance These and previous laboratory results suggest that female rock lizards may select to settle in home ranges based on the characteristics of scent-marks from conspecific males. Therefore, male rock lizards might attract more females and obtain more matings by increasing the proportion of ergosterol when scent-marking their territories. However, previous studies suggest that the allocation of ergosterol to secretions may be costly and only high quality males could afford it, thus, allowing the evolution of scent-marks as an honest sexual display. PMID:22253895

Male Choice in the Stream-Anadromous Stickleback Complex

PubMed Central

McKinnon, Jeffrey S.; Hamele, Nick; Frey, Nicole; Chou, Jennifer; McAleavey, Leia; Greene, Jess; Paulson, Windi

2012-01-01

Studies of mating preferences and pre-mating reproductive isolation have often focused on females, but the potential importance of male preferences is increasingly appreciated. We investigated male behavior in the context of reproductive isolation between divergent anadromous and stream-resident populations of threespine stickleback, Gasterosteus aculeatus, using size-manipulated females of both ecotypes. Specifically, we asked if male courtship preferences are present, and if they are based on relative body size, non-size aspects of ecotype, or other traits. Because male behaviors were correlated with each other, we conducted a principal components analysis on the correlations and ran subsequent analyses on the principal components. The two male ecotypes differed in overall behavioral frequencies, with stream-resident males exhibiting consistently more vigorous and positive courtship than anadromous males, and an otherwise aggressive behavior playing a more positive role in anadromous than stream-resident courtship. We observed more vigorous courtship toward smaller females by (relatively small) stream-resident males and the reverse pattern for (relatively large) anadromous males. Thus size-assortative male courtship preferences may contribute to reproductive isolation in this system, although preferences are far from absolute. We found little indication of males responding preferentially to females of their own ecotype independent of body size. PMID:22701589

Male-to-male transmission in extended pedigrees with multiple cases of autism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hallmayer, J.; Spiker, D.; Lotspeich, L.

Despite strong genetic influences in autism, the true mode of inheritance remains unknown. Sex differences in autism have been described in both singleton and multiplex families: boys outnumber girls by 3 or 4 to 1, and so a sex-linked mode of transmission must also be considered. The key characteristic of X-linkage is that all sons of affected men are unaffected (no male-to-male transmission). In the present study, which is part of an ongoing linkage project in autism, we describe 77 multiplex autism families, 11 of who are affected cousin or half-sibling families. By using these families, it is possible tomore » trace the path of genetic transmission and observe whether the hypothesis of X-linkage is tenable. Of 11 extended pedigrees from 77 multiplex families, six show male-to-male transmission; in these families, X-linkage can be excluded as the genetic basis for their autism. The data from the other five families are compatible with either an autosomal or an X-linked mode of transmission. The key point to emerge, then, is that autism cannot be exclusively an X-linked disorder; there must be an autosomal mode of transmission at least in some families. Thus we must consider the alternative hypotheses that autism is either entirely autosomal, or it is genetically heterogeneous, involving at least one autosomal locus with gender-specific expression, as well as a possible locus on the X-chromosome. 28 refs., 1 fig.« less

Testosterone and reproductive effort in male primates

PubMed Central

Muller, Martin N.

2016-01-01

Considerable evidence suggests that the steroid hormone testosterone mediates major life-history trade-offs in vertebrates, promoting mating effort at the expense of parenting effort or survival. Observations from a range of wild primates support the “Challenge Hypothesis,” which posits that variation in male testosterone is more closely associated with aggressive mating competition than with reproductive physiology. In both seasonally and non-seasonally breeding species, males increase testosterone production primarily when competing for fecund females. In species where males compete to maintain long-term access to females, testosterone increases when males are threatened with losing access to females, rather than during mating periods. And when male status is linked to mating success, and dependent on aggression, high-ranking males normally maintain higher testosterone levels than subordinates, particularly when dominance hierarchies are unstable. Trade-offs between parenting effort and mating effort appear to be weak in most primates, because direct investment in the form of infant transport and provisioning is rare. Instead, infant protection is the primary form of paternal investment in the order. Testosterone does not inhibit this form of investment, which relies on male aggression. Testosterone has a wide range of effects in primates that plausibly function to support male competitive behavior. These include psychological effects related to dominance striving, analgesic effects, and effects on the development and maintenance of the armaments and adornments that males employ in mating competition. PMID:27616559

Testosterone and reproductive effort in male primates.

PubMed

Muller, Martin N

2017-05-01

Considerable evidence suggests that the steroid hormone testosterone mediates major life-history trade-offs in vertebrates, promoting mating effort at the expense of parenting effort or survival. Observations from a range of wild primates support the "Challenge Hypothesis," which posits that variation in male testosterone is more closely associated with aggressive mating competition than with reproductive physiology. In both seasonally and non-seasonally breeding species, males increase testosterone production primarily when competing for fecund females. In species where males compete to maintain long-term access to females, testosterone increases when males are threatened with losing access to females, rather than during mating periods. And when male status is linked to mating success, and dependent on aggression, high-ranking males normally maintain higher testosterone levels than subordinates, particularly when dominance hierarchies are unstable. Trade-offs between parenting effort and mating effort appear to be weak in most primates, because direct investment in the form of infant transport and provisioning is rare. Instead, infant protection is the primary form of paternal investment in the order. Testosterone does not inhibit this form of investment, which relies on male aggression. Testosterone has a wide range of effects in primates that plausibly function to support male competitive behavior. These include psychological effects related to dominance striving, analgesic effects, and effects on the development and maintenance of the armaments and adornments that males employ in mating competition. Copyright © 2016 Elsevier Inc. All rights reserved.

Male circumcision and HIV infection risk.

PubMed

Krieger, John N

2012-02-01

Male circumcision is being promoted to reduce human immunodeficiency virus type 1 (HIV) infection rates. This review evaluates the scientific evidence suggesting that male circumcision reduces HIV infection risk in high-risk heterosexual populations. We followed the updated International Consultation on Urological Diseases evidence-based medicine recommendations to critically review the scientific evidence on male circumcision and HIV infection risk. Level 1 evidence supports the concept that male circumcision substantially reduces the risk of HIV infection. Three major lines of evidence support this conclusion: biological data suggesting that this concept is plausible, data from observational studies supported by high-quality meta-analyses, and three randomized clinical trials supported by high-quality meta-analyses. The evidence from these biological studies, observational studies, randomized controlled clinical trials, meta-analyses, and cost-effectiveness studies is conclusive. The challenges to implementation of male circumcision as a public health measure in high-risk populations must now be faced.

Switching photo-stimulated males between groups of goats does not improve the reproductive response during the male effect.

PubMed

Loya-Carrera, J; Bedos, M; Ponce-Covarrubias, J L; Hernández, H; Chemineau, P; Keller, M; Delgadillo, J A

2014-04-01

We aimed to determine whether the daily exchange of photo-stimulated males among subgroups of females improved the reproductive response of anestrous goats exposed to males. Bucks were rendered sexually active during the rest season by exposure to 2.5 months of long days from November 1st. In April, males (n=3) were put in contact with three subgroups of anestrous goats (one male per 12 females) where they remained throughout the study, constituting the fixed-group. Other males (n=3) were put in contact with three subgroups of females (one male per 11-12 females) and were rotated daily among them, constituting the rotated-group. The sexual behavior of all males was registered from 08:00 to 09:00 on days 0, 1, 2, and 8 after exchanging the males from the subgroups of females. Ovulation and pregnancy rates were determined by transrectal ultrasonography. The occurrences of ano-genital sniffing, nudging (days 1, 2, and 8), and mounting attempts (days 2 and 8) were greater in the rotated than in the fixed-group (P<0.01). The proportions of females that ovulated did not differ among goats from the fixed (92%) and rotated-group (94%; P>0.05). The proportion of pregnant females and the fertility at kidding did not differ between those from the rotated (79% and 59%) and fixed-group (83% and 61%; P>0.05). We conclude that the daily exchange of photo-stimulated males among subgroups induced an increase of their sexual behavior, but does not improve the pregnancy rates in seasonal anestrous goats. Copyright © 2014 Elsevier B.V. All rights reserved.

Paget disease of the male nipple.

PubMed

El Harroudi, T; Tijami, F; El Otmany, A; Jalil, A

2010-01-01

Breast cancer occurring in the mammary gland of men is infrequent. It accounts for 0.8% of all breast cancers, which is less than one per cent of all newly diagnosed male cancers and 0.2% of male cancer deaths. However, Paget disease of the male nipple is extremely rare. We report a single case of Paget disease with infiltrative ductal carcinoma of the breast in a 61-year-old man.

Male gametogenesis without centrioles.

PubMed

Riparbelli, Maria Giovanna; Callaini, Giuliano

2011-01-15

The orientation of the mitotic spindle plays a central role in specifying stem cell-renewal by enabling interaction of the daughter cells with external cues: the daughter cell closest to the hub region is instructed to self-renew, whereas the distal one starts to differentiate. Here, we have analyzed male gametogenesis in DSas-4 Drosophila mutants and we have reported that spindle alignment and asymmetric divisions are properly executed in male germline stem cells that lack centrioles. Spermatogonial divisions also correctly proceed in the absence of centrioles, giving rise to cysts of 16 primary spermatocytes. By contrast, abnormal meiotic spindles assemble in primary spermatocytes. These results point to different requirements for centrioles during male gametogenesis of Drosophila. Spindle formation during germ cell mitosis may be successfully supported by an acentrosomal pathway that is inadequate to warrant the proper execution of meiosis. Copyright © 2010 Elsevier Inc. All rights reserved.

Managing Male Mammary Maladies

PubMed Central

Fentiman, Ian S.

2018-01-01

This review examines the symptoms, need for referral and management of the benign breast conditions which afflict males, together with the steps that are necessary to exclude or confirm male breast cancer. The most common complaint is gynaecomastia, either true or pseudo, and the majority of these cases need reassurance without over-investigation. Drugs that induce breast enlargement are described in order that, when possible, a medication switch can be made. Men receiving endocrine therapy for prostate cancer may develop painful gynaecomastia and this can be relieved with tamoxifen. All men with breast cancer need mammography as part of their work-up but this should not be used as a screening technique for symptomatic males. Because of lack of lobular development, both cysts and fibroadenomas are very rare in men; but those with nipple discharge need referral and investigation as some will have underlying malignancy. PMID:29322112

Sources of male chauvinism in the TAT.

PubMed

Potkay, C R; Merrens, M R

1975-10-01

Potential sources of antifemale bias in TAT stimuli were evaluated by having 358 undergraduate subjects rate 17 male and 17 female TAT figures on 7-point anchored scales. Data from the five independent rating conditions were examined by 2 x 2 ANOVA. Biases toward greater Mental Health and Intelligence for female figures were seen to be insufficient counterbalancers of biases toward greater Cultural Favorability and Identification for male figures. Achievement status was rated equivalently. TAT stimuli appeared to show a "built in" source of male chauvinism systematically "pulling" male-sex identification. Potential for unfavorable clinical evaluation was seen to be greater for female TAT subjects compared with male subjects.

Rights and representations: querying the male-to-male sexual subject in India.

PubMed

Boyce, Paul; Khanna, Akshay

2011-01-01

Same-sex sexualities in India have been portrayed in research and activism as socially marginal and minoritarian. Whilst proceeding from a commitment to the political utility of such a view, this paper questions such a standpoint. Drawing on ethnographic research conducted in different sites, the paper considers male-to-male sexualities as enacted and implicated in the production of ostensibly heteronormative spaces. This, in turn, raises questions about the representation of the queer or same-sex sexual subject in law and HIV prevention, especially in the context of post-colonial perspectives on sexuality.

Eating Disorders in Adolescent Males

ERIC Educational Resources Information Center

Ray, Shannon L.

2004-01-01

Research indicates that the primary onset of eating disorders occurs in adolescence and that there is a growing prevalence of adolescent males with eating disorders. This article describes the eating disorders of anorexia nervosa and bulimia nervosa as they relate to adolescent males. Diagnostic criteria, at-risk groups, and implications for…

Latino Males in Higher Education

ERIC Educational Resources Information Center

Excelencia in Education, 2016

2016-01-01

This 2016 fact sheet profiles the status of Latino males in higher education, providing information on population, college enrollment, and educational attainment. While college enrollment among Latino males continues to increase, they still lag behind Latino females in college enrollment--a disparity that increases as the level of higher education…

Effects of playing a violent video game as male versus female avatar on subsequent aggression in male and female players.

PubMed

Yang, Grace S; Huesmann, L Rowell; Bushman, Brad J

2014-01-01

Previous research has shown that violent video games can increase aggression in players immediately after they play. The present research examines the effects of one subtle cue within violent video games that might moderate these effects-whether the avatar is male or female. One common stereotype is that males are more aggressive than females. Thus, playing a violent video game as a male avatar, compared to a female avatar, should be more likely to prime aggressive thoughts and inclinations in players and lead to more aggressive behavior afterwards. Male and female university students (N = 242) were randomly assigned to play a violent video game as a male or female avatar. After gameplay, participants gave an ostensible partner who hated spicy food hot sauce to eat. The amount of hot sauce given was used to measure aggression. Consistent with priming theory, results showed that both male and female participants who played a violent game as a male avatar behaved more aggressively afterwards than those who played as female avatar. The priming effects of the male avatar were somewhat stronger for male participants than for female participants, suggesting that male participants identified more with the male avatar than did the female participants. These results are particularly noteworthy because they are consistent with another recent experiment showing that playing a violent game as an avatar with a different stereotypically aggressive attribute (black skin color) stimulates more aggression than playing as an avatar without the stereotypically aggressive attribute (Yang et al., 2014, Social Psychological and Personality Science). © 2014 Wiley Periodicals, Inc.

Male-only systemic lupus.

PubMed

Aggarwal, Rachna; Namjou, Bahram; Li, Shibo; D'Souza, Anil; Tsao, Betty P; Bruner, Benjamin F; James, Judith A; Scofield, R Hal

2010-07-01

Systemic lupus erythematosus (SLE) is more common among women than men, a ratio of about 10 to 1. We undertook this study to describe familial male SLE within a large familial SLE cohort. SLE families (2 or more patients) were identified from the Lupus Multiplex Registry and Repository. Genomic DNA and blood samples were obtained using standard methods. Autoantibodies were determined by multiple methods. Medical records were abstracted for SLE clinical data. Fluorescent in situ hybridization (FISH) was performed with X and Y centromere-specific probes, and a probe specific for the Toll-like receptor 7 gene on the X chromosome. Among 523 SLE families, we found 5 families in which all the SLE patients were male. FISH found no yaa gene equivalent in these families. SLE-unaffected primary female relatives from the 5 families with only-male SLE patients had a statistically increased rate of positive antinuclear antibodies compared to SLE-unaffected female relatives in other families. White men with SLE were 5 times more likely to have an offspring with SLE than White women with SLE, but there was no difference in this likelihood among Black men. Because women in the all-male families had positive antinuclear antibodies, and men are more likely to have children with SLE, these data suggest genetic susceptibility factors that act only in men.

Construction of a male sterility system for hybrid rice breeding and seed production using a nuclear male sterility gene

PubMed Central

Chang, Zhenyi; Chen, Zhufeng; Wang, Na; Xie, Gang; Lu, Jiawei; Yan, Wei; Zhou, Junli; Tang, Xiaoyan; Deng, Xing Wang

2016-01-01

The breeding and large-scale adoption of hybrid seeds is an important achievement in agriculture. Rice hybrid seed production uses cytoplasmic male sterile lines or photoperiod/thermo-sensitive genic male sterile lines (PTGMS) as female parent. Cytoplasmic male sterile lines are propagated via cross-pollination by corresponding maintainer lines, whereas PTGMS lines are propagated via self-pollination under environmental conditions restoring male fertility. Despite huge successes, both systems have their intrinsic drawbacks. Here, we constructed a rice male sterility system using a nuclear gene named Oryza sativa No Pollen 1 (OsNP1). OsNP1 encodes a putative glucose–methanol–choline oxidoreductase regulating tapetum degeneration and pollen exine formation; it is specifically expressed in the tapetum and miscrospores. The osnp1 mutant plant displays normal vegetative growth but complete male sterility insensitive to environmental conditions. OsNP1 was coupled with an α-amylase gene to devitalize transgenic pollen and the red fluorescence protein (DsRed) gene to mark transgenic seed and transformed into the osnp1 mutant. Self-pollination of the transgenic plant carrying a single hemizygous transgene produced nontransgenic male sterile and transgenic fertile seeds in 1:1 ratio that can be sorted out based on the red fluorescence coded by DsRed. Cross-pollination of the fertile transgenic plants to the nontransgenic male sterile plants propagated the male sterile seeds of high purity. The male sterile line was crossed with ∼1,200 individual rice germplasms available. Approximately 85% of the F1s outperformed their parents in per plant yield, and 10% out-yielded the best local cultivars, indicating that the technology is promising in hybrid rice breeding and production. PMID:27864513

Tobacco and Alcohol in Relation to Male Breast Cancer: An Analysis of the Male Breast Cancer Pooling Project Consortium

PubMed Central

Cook, Michael B.; Guénel, Pascal; Gapstur, Susan M.; van den Brandt, Piet A.; Michels, Karin B.; Casagrande, John T.; Cooke, Rosie; Van Den Eeden, Stephen K.; Ewertz, Marianne; Falk, Roni T.; Gaudet, Mia M.; Gkiokas, George; Habel, Laurel A.; Hsing, Ann W.; Johnson, Kenneth; Kolonel, Laurence N.; La Vecchia, Carlo; Lynge, Elsebeth; Lubin, Jay H.; McCormack, Valerie A.; Negri, Eva; Olsson, Håkan; Parisi, Dominick; Petridou, Eleni Th.; Riboli, Elio; Sesso, Howard D.; Swerdlow, Anthony; Thomas, David B.; Willett, Walter C.; Brinton, Louise A.

2015-01-01

Background The etiology of male breast cancer is poorly understood, partly due to its relative rarity. Although tobacco and alcohol exposures are known carcinogens, their association with male breast cancer risk remains ill-defined. Methods The Male Breast Cancer Pooling Project consortium provided 2,378 cases and 51,959 controls for analysis from 10 case-control and 10 cohort studies. Individual participant data were harmonized and pooled. Unconditional logistic regression was used to estimate study design-specific (case-control/cohort) odds ratios (OR) and 95% confidence intervals (CI), which were then combined using fixed effects meta-analysis. Results Cigarette smoking status, smoking pack-years, duration, intensity, and age at initiation were not associated with male breast cancer risk. Relations with cigar and pipe smoking, tobacco chewing, and snuff use were also null. Recent alcohol consumption and average grams of alcohol consumed per day were also not associated with risk; only one sub-analysis of very high recent alcohol consumption (>60 grams/day) was tentatively associated with male breast cancer (ORunexposed referent=1.29, 95%CI:0.97–1.71; OR>0–<7 g/day referent=1.36, 95%CI:1.04–1.77). Specific alcoholic beverage types were not associated with male breast cancer. Relations were not altered when stratified by age or body mass index. Conclusions In this analysis of the Male Breast Cancer Pooling Project we found little evidence that tobacco and alcohol exposures were associated with risk of male breast cancer. Impact Tobacco and alcohol do not appear to be carcinogenic for male breast cancer. Future studies should aim to assess these exposures in relation to subtypes of male breast cancer. PMID:25515550

Tobacco and alcohol in relation to male breast cancer: an analysis of the male breast cancer pooling project consortium.

PubMed

Cook, Michael B; Guénel, Pascal; Gapstur, Susan M; van den Brandt, Piet A; Michels, Karin B; Casagrande, John T; Cooke, Rosie; Van Den Eeden, Stephen K; Ewertz, Marianne; Falk, Roni T; Gaudet, Mia M; Gkiokas, George; Habel, Laurel A; Hsing, Ann W; Johnson, Kenneth; Kolonel, Laurence N; La Vecchia, Carlo; Lynge, Elsebeth; Lubin, Jay H; McCormack, Valerie A; Negri, Eva; Olsson, Håkan; Parisi, Dominick; Petridou, Eleni Th; Riboli, Elio; Sesso, Howard D; Swerdlow, Anthony; Thomas, David B; Willett, Walter C; Brinton, Louise A

2015-03-01

The etiology of male breast cancer is poorly understood, partly due to its relative rarity. Although tobacco and alcohol exposures are known carcinogens, their association with male breast cancer risk remains ill-defined. The Male Breast Cancer Pooling Project consortium provided 2,378 cases and 51,959 controls for analysis from 10 case-control and 10 cohort studies. Individual participant data were harmonized and pooled. Unconditional logistic regression was used to estimate study design-specific (case-control/cohort) ORs and 95% confidence intervals (CI), which were then combined using fixed-effects meta-analysis. Cigarette smoking status, smoking pack-years, duration, intensity, and age at initiation were not associated with male breast cancer risk. Relations with cigar and pipe smoking, tobacco chewing, and snuff use were also null. Recent alcohol consumption and average grams of alcohol consumed per day were also not associated with risk; only one subanalysis of very high recent alcohol consumption (>60 g/day) was tentatively associated with male breast cancer (ORunexposed referent = 1.29; 95% CI, 0.97-1.71; OR>0-<7 g/day referent = 1.36; 95% CI, 1.04-1.77). Specific alcoholic beverage types were not associated with male breast cancer. Relations were not altered when stratified by age or body mass index. In this analysis of the Male Breast Cancer Pooling Project, we found little evidence that tobacco and alcohol exposures were associated with risk of male breast cancer. Tobacco and alcohol do not appear to be carcinogenic for male breast cancer. Future studies should aim to assess these exposures in relation to subtypes of male breast cancer. ©2014 American Association for Cancer Research.

Construction of a male sterility system for hybrid rice breeding and seed production using a nuclear male sterility gene.

PubMed

Chang, Zhenyi; Chen, Zhufeng; Wang, Na; Xie, Gang; Lu, Jiawei; Yan, Wei; Zhou, Junli; Tang, Xiaoyan; Deng, Xing Wang

2016-12-06

The breeding and large-scale adoption of hybrid seeds is an important achievement in agriculture. Rice hybrid seed production uses cytoplasmic male sterile lines or photoperiod/thermo-sensitive genic male sterile lines (PTGMS) as female parent. Cytoplasmic male sterile lines are propagated via cross-pollination by corresponding maintainer lines, whereas PTGMS lines are propagated via self-pollination under environmental conditions restoring male fertility. Despite huge successes, both systems have their intrinsic drawbacks. Here, we constructed a rice male sterility system using a nuclear gene named Oryza sativa No Pollen 1 (OsNP1). OsNP1 encodes a putative glucose-methanol-choline oxidoreductase regulating tapetum degeneration and pollen exine formation; it is specifically expressed in the tapetum and miscrospores. The osnp1 mutant plant displays normal vegetative growth but complete male sterility insensitive to environmental conditions. OsNP1 was coupled with an α-amylase gene to devitalize transgenic pollen and the red fluorescence protein (DsRed) gene to mark transgenic seed and transformed into the osnp1 mutant. Self-pollination of the transgenic plant carrying a single hemizygous transgene produced nontransgenic male sterile and transgenic fertile seeds in 1:1 ratio that can be sorted out based on the red fluorescence coded by DsRed Cross-pollination of the fertile transgenic plants to the nontransgenic male sterile plants propagated the male sterile seeds of high purity. The male sterile line was crossed with ∼1,200 individual rice germplasms available. Approximately 85% of the F1s outperformed their parents in per plant yield, and 10% out-yielded the best local cultivars, indicating that the technology is promising in hybrid rice breeding and production.

Adolescent male health

PubMed Central

Westwood, Michael; Pinzon, Jorge

2008-01-01

Although adolescent males have as many health issues and concerns as adolescent females, they are much less likely to be seen in a clinical setting. This is related to both individual factors and the health care system itself, which is not always encouraging and set up to provide comprehensive male health care. Working with adolescent boys involves gaining the knowledge and skills to address concerns such as puberty and sexuality, substance use, violence, risk-taking behaviours and mental health issues. The ability to engage the young male patient is critical, and the professional must be comfortable in initiating conversation about a wide array of topics with the teen boy, who may be reluctant to discuss his concerns. It is important to take every opportunity with adolescent boys to talk about issues beyond the presenting complain, and let them know about confidential care. The physician can educate teens about the importance of regular checkups, and that they are welcome to contact the physician if they are experiencing any concerns about their health or well-being. Parents of preadolescent and adolescent boys should be educated on the value of regular health maintenance visits for their sons beginning in their early teen years. PMID:19119350

Social Control of Hypothalamus-Mediated Male Aggression.

PubMed

Yang, Taehong; Yang, Cindy F; Chizari, M Delara; Maheswaranathan, Niru; Burke, Kenneth J; Borius, Maxim; Inoue, Sayaka; Chiang, Michael C; Bender, Kevin J; Ganguli, Surya; Shah, Nirao M

2017-08-16

How environmental and physiological signals interact to influence neural circuits underlying developmentally programmed social interactions such as male territorial aggression is poorly understood. We have tested the influence of sensory cues, social context, and sex hormones on progesterone receptor (PR)-expressing neurons in the ventromedial hypothalamus (VMH) that are critical for male territorial aggression. We find that these neurons can drive aggressive displays in solitary males independent of pheromonal input, gonadal hormones, opponents, or social context. By contrast, these neurons cannot elicit aggression in socially housed males that intrude in another male's territory unless their pheromone-sensing is disabled. This modulation of aggression cannot be accounted for by linear integration of environmental and physiological signals. Together, our studies suggest that fundamentally non-linear computations enable social context to exert a dominant influence on developmentally hard-wired hypothalamus-mediated male territorial aggression. Copyright © 2017 Elsevier Inc. All rights reserved.

Establishment of a novel dwarf rat strain: cartilage calcification insufficient (CCI) rats

PubMed Central

TANAKA, Masami; WATANABE, Minoru; YOKOMI, Izuru; MATSUMOTO, Naoki; SUDO, Katsuko; SATOH, Hitoshi; IGARASHI, Tsuneo; SEKI, Azusa; AMANO, Hitoshi; OHURA, Kiyoshi; RYU, Kakei; SHIBATA, Shunichi; NAGAYAMA, Motohiko; TANUMA, Jun-ichi

2014-01-01

Rats with dwarfism accompanied by skeletal abnormalities, such as shortness of the limbs, tail, and body (dwarf rats), emerged in a Jcl-derived Sprague-Dawley rat colony maintained at the Institute for Animal Experimentation, St. Marianna University Graduate School of Medicine. Since the dwarfism was assumed to be due to a genetic mutation based on its frequency, we bred the dwarf rats and investigated their characteristics in order to identify the causative factors of their phenotypes and whether they could be used as a human disease model. One male and female that produced dwarf progeny were selected, and reproduction was initiated by mating the pair. The incidence of dwarfism was 25.8% among the resultant litter, and dwarfism occurred in both genders, suggesting that it was inherited in an autosomal recessive manner. At 12 weeks of age, the body weights of the male and female dwarf rats were 40% and 57% of those of the normal rats, respectively. In soft X-ray radiographic and histological examinations, shortening and hypoplasia of the long bones, such as the tibia and femur, were observed, which were suggestive of endochondral ossification abnormalities. An immunohistochemical examination detected an aggrecan synthesis disorder, which might have led to delayed calcification and increased growth plate thickening in the dwarf rats. We hypothesized that the principal characteristics of the dwarf rats were systemically induced by insufficient cartilage calcification in their long bones; thus, we named them cartilage calcification insufficient (CCI) rats. PMID:25736479

Cost of reproduction in Callosobruchus maculatus: effects of mating on male longevity and the effect of male mating status on female longevity.

PubMed

Paukku, Satu; Kotiaho, Janne S

2005-11-01

One of the most studied life-history trade-offs is that resulting from the cost of reproduction: a trade-off arises when reproduction diverts limited resources from other life-history traits. We examine the cost of reproduction in male, and the effect of male mating status on female Callosobruchus maculatus seed beetles. Cost of reproduction for male C. maculatus was manifested as reduced longevity. There was also a positive relationship between male body size and male longevity. Females mated to males that had already copulated twice did not live as long as females mated to males that had copulated once or not at all. The third copulation of males also lasted longer than the two previous ones. We conclude that even though the cost of reproduction for males has been studied much less than that in females, there is growing evidence that male reproductive effort is more complex than has traditionally been thought.

Asymmetric reproductive character displacement in male aggregation behaviour

PubMed Central

Pfennig, Karin S.; Stewart, Alyssa B.

2011-01-01

Reproductive character displacement—the evolution of traits that minimize reproductive interactions between species—can promote striking divergence in male signals or female mate preferences between populations that do and do not occur with heterospecifics. However, reproductive character displacement can affect other aspects of mating behaviour. Indeed, avoidance of heterospecific interactions might contribute to spatial (or temporal) aggregation of conspecifics. We examined this possibility in two species of hybridizing spadefoot toad (genus Spea). We found that in Spea bombifrons sympatric males were more likely than allopatric males to associate with calling males. Moreover, contrary to allopatric males, sympatric S. bombifrons males preferentially associated with conspecific male calls. By contrast, Spea multiplicata showed no differences between sympatry and allopatry in likelihood to associate with calling males. Further, sympatric and allopatric males did not differ in preference for conspecifics. However, allopatric S. multiplicata were more variable than sympatric males in their responses. Thus, in S. multiplicata, character displacement may have refined pre-existing aggregation behaviour. Our results suggest that heterospecific interactions can foster aggregative behaviour that might ultimately contribute to clustering of conspecifics. Such clustering can generate spatial or temporal segregation of reproductive activities among species and ultimately promote reproductive isolation. PMID:21177683

Sexual size dimorphism, canine dimorphism, and male-male competition in primates: where do humans fit in?

PubMed

Plavcan, J Michael

2012-03-01

Sexual size dimorphism is generally associated with sexual selection via agonistic male competition in nonhuman primates. These primate models play an important role in understanding the origins and evolution of human behavior. Human size dimorphism is often hypothesized to be associated with high rates of male violence and polygyny. This raises the question of whether human dimorphism and patterns of male violence are inherited from a common ancestor with chimpanzees or are uniquely derived. Here I review patterns of, and causal models for, dimorphism in humans and other primates. While dimorphism in primates is associated with agonistic male mate competition, a variety of factors can affect male and female size, and thereby dimorphism. The causes of human sexual size dimorphism are uncertain, and could involve several non-mutually-exclusive mechanisms, such as mate competition, resource competition, intergroup violence, and female choice. A phylogenetic reconstruction of the evolution of dimorphism, including fossil hominins, indicates that the modern human condition is derived. This suggests that at least some behavioral similarities with Pan associated with dimorphism may have arisen independently, and not directly from a common ancestor.

[Environmental factors and male fertility].

PubMed

Köhn, F-M; Schuppe, H C

2016-07-01

The identification of potential environmental hazards may have clinical relevance for diagnosis of male infertility. Knowledge about these factors will improve prevention of fertility disorders. Apart from drugs or factors related to lifestyle such as alcohol and tobacco smoke, various environmental and occupational agents, both chemical and physical, may impair male reproductive functions. With regard to the complex regulation of the male reproductive system, the available information concerning single exogenous factors and their mechanisms of action in humans is limited. This is also due to the fact that extrapolation of results obtained from experimental animal studies remains difficult. Nevertheless, the assessment of relevant exposures to reproductive toxicants should be carefully evaluated during diagnostic procedures of andrological patients.

HIV risks among two types of male migrants in Shanghai, China: money boys vs. general male migrants.

PubMed

He, Na; Wong, Frank Y; Huang, Z Jennifer; Ding, Yingying; Fu, Chaowei; Smith, Brian D; Young, Darwin; Jiang, Qingwu

2007-12-01

To examine HIV/AIDS-related knowledge, attitudes and behaviours among 'money boys' and general male migrants in Shanghai, China. A quantitative cross-sectional design with self-administered paper-and-pencil instruments was used. A total of 239 money boys were enrolled using community popular opinion leader and respondent-driven sampling methods, and 100 general male migrants were enrolled through venue-based sampling. Compared to general male migrants, money boys were significantly younger, better educated, more likely to be single, earned a higher income, suffered greater stress, and were less satisfied with life in Shanghai. Both groups had substantial misconceptions about HIV/AIDS, although general male migrants were less well informed. Furthermore, both groups reported low rates of condom use, regardless of who their sexual partners were. Money boys were more likely to use alcohol, had more sexual partners and more casual sex partners, and were more likely to engage in other sexual risks. Moreover, they were likely to be the victims of sexual violence at the hands of their clients. More than half of the money boys had been tested for HIV and 3% self-reported to be HIV-positive, whereas only 1% of the general male migrants had ever been tested and all self-reported to be HIV-negative. Infection with other sexually transmitted diseases was also reported by money boys. This study suggests an urgent need to implement HIV/AIDS prevention and intervention programs targeting male migrants, especially money boys and their clients. Some recommendations for conducting interventions among the male migrant population in China are suggested.

Empowering Young Black Males--III: A Systematic Modular Training Program for Black Male Children & Adolescents.

ERIC Educational Resources Information Center

Lee, Courtland C.

This series of five interrelated modules is an update and revision of "Saving the Native Son: Empowerment Strategies for Young Black Males (1996)." It offers specific strategies for empowering young African American males to help them achieve optimal educational and social success. Empowerment is a developmental process by which people who are…

Complementary transcriptome and proteome profiling in cabbage buds of a recessive male sterile mutant provides new insights into male reproductive development.

PubMed

Ji, Jialei; Yang, Limei; Fang, Zhiyuan; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao; Liu, Yumei; Li, Zhansheng

2018-05-15

Plant male reproductive development is a very complex biological process that involves multiple metabolic pathways. To reveal novel insights into male reproductive development, we conducted an integrated profiling of gene activity in the developing buds of a cabbage recessive genetic male sterile mutant. Using RNA-Seq and label-free quantitative proteomics, 2881 transcripts and 1245 protein species were identified with significant differential abundance between the male sterile line 83121A and its isogenic maintainer line 83121B. Analyses of function annotations and correlations between transcriptome and proteome and protein interaction networks were also conducted, which suggested that the male sterility involves a complex regulatory pattern. Moreover, several key biological processes, such as fatty acid metabolism, tapetosome biosynthesis, amino acid metabolism and protein synthesis and degradation were identified as being of relevance to male reproductive development. A large number of protein species involved in sporopollenin synthesis, amino acid synthesis, ribosome assembly, protein processing in endoplasmic reticulum and lipid transfer were observed to be significantly down-accumulated in 83121A buds, indicating their potential roles in the regulation of cabbage microspore abortion. In summary, the conjoint analysis of the transcriptome and proteome provided a global picture regarding the molecular dynamics in male sterile buds of 83121A. Male sterile mutants are excellent materials for the study of plant male reproductive development. This study revealed the molecular dynamics of recessive male sterility in cabbage at the transcriptome and proteome levels, which deepens our understanding of the metabolic pathways involved in male development. Moreover, the male sterility-related genes identified in this study could provide a reference for the artificial regulation of cabbage fertility by using genetic engineering technology, which may result in potential

Male infertility and its genetic causes.

PubMed

Miyamoto, Toshinobu; Minase, Gaku; Okabe, Kimika; Ueda, Hiroto; Sengoku, Kazuo

2015-10-01

Infertility is a serious social problem in advanced nations, with male factor infertility accounting for approximately half of all cases of infertility. Here, we aim to discuss our laboratory results in the context of recent literature on critical genes residing on the Y chromosome or autosomes that play important roles in human spermatogenesis. The PubMed database was systematically searched using the following keywords: 'genetics of male factor infertility'; 'male infertility genes', 'genetics of spermatogenesis' to retrieve information for this review. Striking progress has recently been made in the elucidation of mechanisms of spermatogenesis using knockout mouse models. This information has, in many cases, not been directly translatable to humans. Nevertheless, mutations in several critical genes have been shown to cause male infertility. We discuss here the contribution to male factor infertility of a number of genes identified in the azoospermia factor (AZF) region on the Y chromosome, as well as the autosomally located genes: SYKP3, KLHL10, AURKC and SPATA16. Non-obstructive azoospermia is the most severe form of azoospermia. However, the presence of spermatozoa can only be confirmed through procedures, which may prove to be unnecessary. Elucidation of the genes underlying male factor infertility, and thereby a better understanding of the mechanisms that cause it, will result in more tailored, evidence-based decisions in treatment of patients. © 2015 Japan Society of Obstetrics and Gynecology.

[Male sexual and reproductive rights].

PubMed

Diaz, A M

1998-06-01

In late 1997, PROFAMILIA began a study of the role of male sexual and reproductive rights as part of the construction of new masculine identities. The work was approached from the disciplines of law and sociology. Patriarchy, as a system of domination, permeated most cultures, giving men a position of power in relation to women and leading to a series of violent and self-destructive male behaviors. The patriarchal system imposed aggressive, promiscuous, risky, and irresponsible behaviors on men, which created a climate for sexual abuse, unwanted pregnancy, propagation of sexually transmitted diseases, and violence against women. Changes in female roles have created the need for changes in male roles. The most visible sexual and reproductive needs of men were studied through literature reviews and semistructured questionnaires with PROFAMILIA clients. Among the needs identified were a new type of male participation in family and domestic life, a new content for male sexual freedom, greater participation of men in reproductive decisions and in raising their children, and new ways of relating to others and sharing feelings and emotions. The need to avoid behaviors that put health at risk was also identified. A review of the evolution of existing sexual and reproductive rights and of the documents that constitute their ethical and juridical framework led to the conclusion that the construction of new rights specifically for men is not necessary, or juridically possible, in the current historical context.

21 CFR 876.5160 - Urological clamp for males.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Urological clamp for males. 876.5160 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males. (a) Identification. A urological clamp for males is a device used to close the urethra of a male to...

General Information about Male Breast Cancer

MedlinePlus

... Male Breast Cancer Treatment (PDQ®)–Patient Version General Information about Male Breast Cancer Go to Health Professional ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

Sexually Antagonistic Selection in Human Male Homosexuality

PubMed Central

Camperio Ciani, Andrea; Cermelli, Paolo; Zanzotto, Giovanni

2008-01-01

Several lines of evidence indicate the existence of genetic factors influencing male homosexuality and bisexuality. In spite of its relatively low frequency, the stable permanence in all human populations of this apparently detrimental trait constitutes a puzzling ‘Darwinian paradox’. Furthermore, several studies have pointed out relevant asymmetries in the distribution of both male homosexuality and of female fecundity in the parental lines of homosexual vs. heterosexual males. A number of hypotheses have attempted to give an evolutionary explanation for the long-standing persistence of this trait, and for its asymmetric distribution in family lines; however a satisfactory understanding of the population genetics of male homosexuality is lacking at present. We perform a systematic mathematical analysis of the propagation and equilibrium of the putative genetic factors for male homosexuality in the population, based on the selection equation for one or two diallelic loci and Bayesian statistics for pedigree investigation. We show that only the two-locus genetic model with at least one locus on the X chromosome, and in which gene expression is sexually antagonistic (increasing female fitness but decreasing male fitness), accounts for all known empirical data. Our results help clarify the basic evolutionary dynamics of male homosexuality, establishing this as a clearly ascertained sexually antagonistic human trait. PMID:18560521

Quantitative genetic models of sexual selection by male choice.

PubMed

Nakahashi, Wataru

2008-09-01

There are many examples of male mate choice for female traits that tend to be associated with high fertility. I develop quantitative genetic models of a female trait and a male preference to show when such a male preference can evolve. I find that a disagreement between the fertility maximum and the viability maximum of the female trait is necessary for directional male preference (preference for extreme female trait values) to evolve. Moreover, when there is a shortage of available male partners or variance in male nongenetic quality, strong male preference can evolve. Furthermore, I also show that males evolve to exhibit a stronger preference for females that are more feminine (less resemblance to males) than the average female when there is a sexual dimorphism caused by fertility selection which acts only on females.

Male infertility and its causes in human.

PubMed

Miyamoto, Toshinobu; Tsujimura, Akira; Miyagawa, Yasushi; Koh, Eitetsu; Namiki, Mikio; Sengoku, Kazuo

2012-01-01

Infertility is one of the most serious social problems facing advanced nations. In general, approximate half of all cases of infertility are caused by factors related to the male partner. To date, various treatments have been developed for male infertility and are steadily producing results. However, there is no effective treatment for patients with nonobstructive azoospermia, in which there is an absence of mature sperm in the testes. Although evidence suggests that many patients with male infertility have a genetic predisposition to the condition, the cause has not been elucidated in the vast majority of cases. This paper discusses the environmental factors considered likely to be involved in male infertility and the genes that have been clearly shown to be involved in male infertility in humans, including our recent findings.

Genetic causes of male infertility.

PubMed

Stouffs, Katrien; Seneca, Sara; Lissens, Willy

2014-05-01

Male infertility, affecting around half of the couples with a problem to get pregnant, is a very heterogeneous condition. Part of patients are having a defect in spermatogenesis of which the underlying causes (including genetic ones) remain largely unknown. The only genetic tests routinely used in the diagnosis of male infertility are the analyses for the presence of Yq microdeletions and/or chromosomal abnormalities. Various other single gene or polygenic defects have been proposed to be involved in male fertility. Yet, their causative effect often remains to be proven. The recent evolution in the development of whole genome-based techniques may help in clarifying the role of genes and other genetic factors involved in spermatogenesis and spermatogenesis defects. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Steinach and Young, Discoverers of the Effects of Estrogen on Male Sexual Behavior and the “Male Brain”1,2

PubMed Central

2015-01-01

Abstract In the 1930s, Eugen Steinach’s group found that estradiol induces lordosis in castrated rats and reduces the threshold dose of testosterone that is necessary for the induction of ejaculation, and that estradiol-treated intact rats display lordosis as well as mounting and ejaculation. The bisexual, estrogen-sensitive male had been demonstrated. Another major, albeit contrasting, discovery was made in the 1950s, when William Young’s group reported that male guinea pigs and prenatally testosterone-treated female guinea pigs are relatively insensitive to estrogen when tested for lordosis as adults. Reduced estrogen sensitivity was part of the new concept of organization of the neural tissues mediating the sexual behavior of females into tissues similar to those of males. The importance of neural organization by early androgen stimulation was realized immediately and led to the discovery of a variety of sex differences in the brains of adult animals. By contrast, the importance of the metabolism of testosterone into estrogen in the male was recognized only after a delay. While the finding that males are sensitive to estrogen was based on Bernhard Zondek’s discovery in 1934 that testosterone is metabolized into estrogen in males, the finding that males are insensitive to estrogen was based on the hypothesis that testosterone–male sexual behavior is the typical relationship in the male. It is suggested that this difference in theoretical framework explains the discrepancies in some of the reported results. PMID:26601123

Cultural factors affecting urban Mexican male homosexual behavior.

PubMed

Carrier, J M

1976-03-01

Some aspects of the mestizoized urban culture in Mexico are linked to male homosexuality in support of the theory that cultural factors play an important role in the kind of life styles and sex practices of males involved in homosexual behavior. The following factors are considered relevant: the sharp dichotomization of gender roles, dual categorization of females as good or bad, separate social networks maintained by males before and after marriage, proportion of unmarried males, and distribution of income. One result of the sharp dichotomization of male and female gender roles is the widely held belief that effeminate males generally prefer to play the female role rather than the male. Effeminacy and homosexuality are also linked by the belief that as a result of this role preference effeminate males are sexually interested only in masculine males with whom they play the passive sex role. The participation of masculine males in homosexual encounters is related in part to a relatively high level of sexual awareness in combination with the lack of stigmatization of the insertor sex role and in part to the restraints placed on alternative sexual outlets by available income and/or marital status. Males involved in homosexual behavior in Mexico operate in a sociocultural environment which gives rise to expectations that they should play either the insertee or insertor sex role but not both and that they should obtain ultimate sexual satisfaction with anal intercourse rather than fellatio. In spite of cultural imperatives, however, individual preferences stemming from other variables such as personality needs, sexual gratification, desires of wanted partners, and amount of involvement may override the imperatives with resulting variations in sexual behavior patterns.

Current medical management of endocrine-related male infertility

PubMed Central

Ring, Joshua D; Lwin, Aye A; Köhler, Tobias S

2016-01-01

Male factor contributes to 50%–60% of overall infertility but is solely responsible in only 20% of couples. Although most male factor infertility is ascertained from an abnormal semen analysis, other male factors can be contributory especially if the sample returns normal. Male infertility can be due to identifiable hormonal or anatomical etiologies that may be reversible or irreversible. This manuscript will highlight existing guidelines and our recommendations for hormone evaluation for male infertility and empiric therapies including multivitamins, estrogen receptor modulators (clomiphene), estrogen conversion blockers (anastrozole), and hormone replacement. PMID:27098657

Male pattern baldness

MedlinePlus

... baldness. Medicines that treat male pattern baldness include: Minoxidil (Rogaine), a solution that is applied directly to ... slows hair loss. It works slightly better than minoxidil. Hair loss returns when you stop using this ...

Male greater sage-grouse detectability on leks

Treesearch

Aleshia L. Fremgen; Christopher P. Hansen; Mark A. Rumble; R. Scott Gamo; Joshua J. Millspaugh

2016-01-01

It is unlikely all male sage-grouse are detected during lek counts, which could complicate the use of lek counts as an index to population abundance. Understanding factors that influence detection probabilities will allow managers to more accurately estimate the number of males present on leks. We fitted 410 males with global positioning system and very high...

The occurrence of female-to-male partner violence among male intimate partner violence offenders mandated to treatment: a brief research report.

PubMed

Crane, Cory A; Hawes, Samuel W; Mandel, Dolores L; Easton, Caroline J

2014-01-01

Little is known about the perceived perpetration of female-to-male intimate partner violence by victims of male offenders mandated to treatment. Sixty-eight male perpetrators of partner violence completed measures of dyadic violent and aggressive responding at intake and at a 12-week follow-up. Approximately 20% of male offenders reported partner violence perpetration and 30% reported victimization with bidirectional violence as the most common configuration of couple violence. Maladaptive responses to conflict were prevalent across partners. Significant and highly correlated reductions in aversive behaviors were detected across the assessment period for both males and their female partners. Results are interpreted within the context of motivational models of female-to-male partner violence and current treatment approaches.

Melatonin and male reproduction.

PubMed

Li, Chunjin; Zhou, Xu

2015-06-15

Melatonin is a neurohormone secreted by the pineal gland whose concentrations in the body are regulated by both the dark-light and seasonal cycles. The reproductive function of seasonal breeding animals is clearly influenced by the circadian variation in melatonin levels. Moreover, a growing body of evidence indicates that melatonin has important effects in the reproduction of some non-seasonal breeding animals. In males, melatonin affects reproductive regulation in three main ways. First, it regulates the secretion of two key neurohormones, GnRH and LH. Second, it regulates testosterone synthesis and testicular maturation. Third, as a potent free radical scavenger that is both lipophilic and hydrophilic, it prevents testicular damage caused by environmental toxins or inflammation. This review summarizes the existing data on the possible biological roles of melatonin in male reproduction. Overall, the literature data indicate that melatonin affects the secretion of both gonadotropins and testosterone while also improving sperm quality. This implies that it has important effects on the regulation of testicular development and male reproduction. Copyright © 2015. Published by Elsevier B.V.

Investigating Instructional Practices of an African American Male Mathematics Teacher with Underachieving African American Male Students

ERIC Educational Resources Information Center

Muhammad, Rhonda K.

2012-01-01

This qualitative study examined the instructional practices of an experienced African American mathematics teacher to determine his perceived capabilities in augmenting academic proficiency for his African American male students. Provided in this descriptive case study are the lived experiences of an African American male teacher working to move…

Advances in Male Contraception

PubMed Central

Page, Stephanie T.; Amory, John K.; Bremner, William J.

2008-01-01

Despite significant advances in contraceptive options for women over the last 50 yr, world population continues to grow rapidly. Scientists and activists alike point to the devastating environmental impacts that population pressures have caused, including global warming from the developed world and hunger and disease in less developed areas. Moreover, almost half of all pregnancies are still unwanted or unplanned. Clearly, there is a need for expanded, reversible, contraceptive options. Multicultural surveys demonstrate the willingness of men to participate in contraception and their female partners to trust them to do so. Notwithstanding their paucity of options, male methods including vasectomy and condoms account for almost one third of contraceptive use in the United States and other countries. Recent international clinical research efforts have demonstrated high efficacy rates (90–95%) for hormonally based male contraceptives. Current barriers to expanded use include limited delivery methods and perceived regulatory obstacles, which stymie introduction to the marketplace. However, advances in oral and injectable androgen delivery are cause for optimism that these hurdles may be overcome. Nonhormonal methods, such as compounds that target sperm motility, are attractive in their theoretical promise of specificity for the reproductive tract. Gene and protein array technologies continue to identify potential targets for this approach. Such nonhormonal agents will likely reach clinical trials in the near future. Great strides have been made in understanding male reproductive physiology; the combined efforts of scientists, clinicians, industry and governmental funding agencies could make an effective, reversible, male contraceptive an option for family planning over the next decade. PMID:18436704

Lycopene and male infertility

PubMed Central

Durairajanayagam, Damayanthi; Agarwal, Ashok; Ong, Chloe; Prashast, Pallavi

2014-01-01

Excessive amounts of reactive oxygen species (ROS) cause a state of oxidative stress, which result in sperm membrane lipid peroxidation, DNA damage and apoptosis, leading to decreased sperm viability and motility. Elevated levels of ROS are a major cause of idiopathic male factor infertility, which is an increasingly common problem today. Lycopene, the most potent singlet oxygen quencher of all carotenoids, is a possible treatment option for male infertility because of its antioxidant properties. By reacting with and neutralizing free radicals, lycopene could reduce the incidence of oxidative stress and thus, lessen the damage that would otherwise be inflicted on spermatozoa. It is postulated that lycopene may have other beneficial effects via nonoxidative mechanisms in the testis, such as gap junction communication, modulation of gene expression, regulation of the cell cycle and immunoenhancement. Various lycopene supplementation studies conducted on both humans and animals have shown promising results in alleviating male infertility—lipid peroxidation and DNA damage were decreased, while sperm count and viability, and general immunity were increased. Improvement of these parameters indicates a reduction in oxidative stress, and thus the spermatozoa is less vulnerable to oxidative damage, which increases the chances of a normal sperm fertilizing the egg. Human trials have reported improvement in sperm parameters and pregnancy rates with supplementation of 4–8 mg of lycopene daily for 3–12 months. However, further detailed and extensive research is still required to determine the dosage and the usefulness of lycopene as a treatment for male infertility. PMID:24675655

Endocrinological correlates of male bimaturism in wild Bornean orangutans.

PubMed

Marty, Pascal R; van Noordwijk, Maria A; Heistermann, Michael; Willems, Erik P; Dunkel, Lynda P; Cadilek, Manuela; Agil, Muhammad; Weingrill, Tony

2015-11-01

Among primates, orangutans are unique in having pronounced male bimaturism leading to two fully adult morphs that differ in both physical appearance and behavior. While unflanged males have a female-like appearance, flanged males have the full suite of secondary sexual characteristics, including cheek flanges and a large throat sac. So far, hormonal correlates of arrested development in unflanged males and the expression of secondary sexual characteristics in flanged males have only been studied in zoo-housed individuals. In this study, we investigated fecal androgen and glucocorticoid metabolites as hormonal correlates of male bimaturism in 17 wild adult Bornean orangutans (Pongo pygmaeus) in Central Kalimantan, Indonesia. We predicted and found higher androgen levels in flanged males compared to unflanged males, probably due to ongoing strong competition among flanged males who meet too infrequently to establish a clear linear dominance hierarchy. Furthermore, we found no difference in fecal glucocorticoid metabolite concentrations between flanged and unflanged males, indicating that social stress is unlikely to explain arrested development in unflanged wild orangutans. The only actively developing male in our study showed significantly higher androgen levels during the period of development than later as a fully flanged male. This supports earlier findings from zoo studies that elevated androgen levels are associated with the development of secondary sexual characteristics. © 2015 Wiley Periodicals, Inc.

Song and Male Quality in Prairie Warblers

Treesearch

Bruce E. Byers; Michael E. Akresh; David I. King; W. Koenig

2016-01-01

To determine if the songs of male prairie warblers could potentially reveal to female listeners information about the quality of singers, we compared various aspects of prairie warbler song structure and performance to attributes that might reflect a male singer's potential to enhance the fitness of his mate. We found that all the tested male attributes—arrival...

Male victims of sexual assault: phenomenology, psychology, physiology.

PubMed

Bullock, Clayton M; Beckson, Mace

2011-01-01

Myths, stereotypes, and unfounded beliefs about male sexuality, in particular male homosexuality, are widespread in legal and medical communities, as well as among agencies providing services to sexual assault victims. These include perceptions that men in noninstitutionalized settings are rarely sexually assaulted, that male victims are responsible for their assaults, that male sexual assault victims are less traumatized by the experience than their female counterparts, and that ejaculation is an indicator of a positive erotic experience. As a result of the prevalence of such beliefs, there is an underreporting of sexual assaults by male victims; a lack of appropriate services for male victims; and, effectively, no legal redress for male sexual assault victims. By comparison, male sexual assault victims have fewer resources and greater stigma than do female sexual assault victims. Many male victims, either because of physiological effects of anal rape or direct stimulation by their assailants, have an erection, ejaculate, or both during the assault. This is incorrectly understood by assailant, victim, the justice system, and the medical community as signifying consent by the victim. Studies of male sexual physiology suggest that involuntary erections or ejaculations can occur in the context of nonconsensual, receptive anal sex. Erections and ejaculations are only partially under voluntary control and are known to occur during times of extreme duress in the absence of sexual pleasure. Particularly within the criminal justice system, this misconception, in addition to other unfounded beliefs, has made the courts unwilling to provide legal remedy to male victims of sexual assault, especially when the victim experienced an erection or an ejaculation during the assault. Attorneys and forensic psychiatrists must be better informed about the physiology of these phenomena to formulate evidence-based opinions.

The Occurrence of Female-to-Male Partner Violence Among Male Intimate Partner Violence Offenders Mandated to Treatment: A Brief Research Report

PubMed Central

Crane, Cory A.; Hawes, Samuel W.; Mandel, Dolores; Easton, Caroline J.

2014-01-01

Little is known about the perceived perpetration of female-to-male intimate partner violence by victims of male offenders mandated to treatment. Sixty-eight male perpetrators of partner violence completed measures of dyadic violent and aggressive responding at intake and at a 12 week follow-up. Approximately 20% of male offenders reported partner violence perpetration and 30% reported victimization with bi-directional violence as the most common configuration of couple violence. Maladaptive responses to conflict were prevalent across partners. Significant and highly correlated reductions in aversive behaviors were detected across the assessment period for both males and their female partners. Results are interpreted within the context of motivational models of female-to-male partner violence and current treatment approaches. PMID:25750479

The form of sexual selection arising from male-male competition depends on the presence of females in the social environment.

PubMed

Procter, D S; Moore, A J; Miller, C W

2012-05-01

Sexual selection arises from social interactions, and if social environments vary so too should sexual selection. For example, male-male competition often occurs either in the presence or in the absence of females, and such changes in the social environment could affect the form and strength of sexual selection. Here we examine how the presence of a female influences selection arising from male-male competition in a leaf-footed cactus bug, Narnia femorata, which has a resource defence mating system. Males compete for territories on cacti because females lay eggs on the cactus plants. Females are not always present when this competition first occurs; however, the presence or absence of the female matters. We found that both the form and strength of selection on male traits, those traits that influenced success in intrasexual competition, depended on the social context. When a female was not present, male size and the area of the sexually dimorphic hind legs was only marginally important to winning a contest. However, males with larger overall size and leg area were more likely to win in the presence of a female. There was also positive quadratic selection on these traits when a female was present with both the largest and the smallest males winning. The implication is unexpected alternative strategies when females are present. Our results support the notion that sexual selection should be studied under all relevant social contexts. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

Genetics Home Reference: familial male-limited precocious puberty

MedlinePlus

... male-limited precocious puberty Familial male-limited precocious puberty Printable PDF Open All Close All Enable Javascript ... expand/collapse boxes. Description Familial male-limited precocious puberty is a condition that causes early sexual development ...

Clinical Use of Aromatase Inhibitors in Adult Males.

PubMed

Tan, Ronny B W; Guay, Andre T; Hellstrom, Wayne J G

2014-04-01

There is a growing interest in the treatment of late-onset hypogonadism, another name for the study of testosterone deficiency in an older age group. Initial attempts at testosterone replacement have also brought attention to the possible adverse effects on the patients' cardiovascular risk factors and their prostate health. The "female" hormone estradiol is no longer considered as the feminizing hormone, as it has been identified to have an effect on the sexual and general well-being of adult males. Urologists and endocrinologists alike have started to pay attention to the serum T/E 2 (testosterone : estradiol) ratio that appears to be more important than the respective individual hormonal levels. Therein lies the possible role of aromatase inhibitors (AIs) in restoring the normal balance of serum testosterone and estradiol levels for the adequate treatment of late-onset hypogonadism, while limiting the potential adverse effects. Currently, other established clinical indications of AIs include the treatment of breast cancer in female patients and developmental growth problems in pediatric patients. This review evaluates the role of AIs as a treatment option for late-onset hypogonadism and the evidence for its other clinical uses in men, including its possible adverse effects. A literature review was performed with regards to the use of aromatase inhibitors in adult males, the role of estrogens in adult males, as well as adverse effect of AIs on bone health in adult males. To evaluate the evidence for the use of AIs in adult males to treat late-onset hypogonadism, obesity-related hypogonadotropic hypogonadism, gynecomastia, and male subfertility. To evaluate the evidence for the possible adverse effects on the bone health of adult males with the use of AIs. Currently there is no literature to recommend the use of AIs in adult males to treat late-onset hypogonadism, obesity-related hypogonadotropic hypogonadism, gynecomastia, or male subfertility, although some

"Brothers Gonna Work It Out:" Understanding the Pedagogic Performance of African American Male Teachers Working with African American Male Students

ERIC Educational Resources Information Center

Brown, Anthony L.

2009-01-01

Drawing from ethnographic data, this paper explores how African American male teachers working with African American male students performed their pedagogy. This paper highlights how teachers' understanding of African American males social and educational needs shaped their pedagogical performance. Interestingly however, teachers' performance was…

Declining Minamata male birth ratio associated with increased male fetal death due to heavy methylmercury pollution.

PubMed

Sakamoto, M; Nakano, A; Akagi, H

2001-10-01

The purpose of this retrospective study was to examine the effect of methylmercury pollution on the sex ratio of offspring at birth and of fetuses at stillbirth in Minamata City, Japan, in the 1950s when severe and widespread methylmercury pollution was experienced. In 4 of 5 years from 1955 to 1959 when methylmercury pollution was most severe, lower numbers of male offspring at birth were observed in the city population. The offspring sex distributions from 1950 to 1969 by 5-year period were calculated in the overall population of Minamata City, in the most prevalent area, in fishermen (most heavily exposed occupation group) and among Minamata disease patients using data from birth certificates. We also similarly calculated the sex ratio of stillborn fetuses in the city population using Kumamoto Prefecture's vital statistics on still-birth. Decreases in male births were observed in offspring in the overall city population, in fishermen, and in maternal Minamata disease patients in the city in 1955-1959, when the methylmercury pollution was most severe. An increase in the proportion of male stillborn fetuses in the city was observed at the time. It is possible that male fetuses were more susceptible to the pollution than their female counterparts, and this could be a cause for the lower numbers of male offspring at birth. Copyright 2001 Academic Press.

Dominance relationships among siamang males living in multimale groups.

PubMed

Morino, Luca

2016-03-01

Intense intolerance among males is considered to be an important mechanism maintaining the uni-male organization traditionally attributed to socially monogamous gibbons. Long-term field work, however, has revealed the existence of stable, socially polyandrous groups in at least two populations, raising questions about the mechanism that allows two adult males to co-reside in the same group. I collected 21 months of behavioral data on 7 two-male groups of wild siamangs (Symphalangus syndactylus) in southern Sumatra (Indonesia) to test the hypothesis that dominance relationships regulate the interactions of adult male siamangs and ultimately facilitate multi-male social groups. A dominant male could clearly be identified in each dyad, based on a consistent direction of agonistic interactions, displacements and the maintenance of an advantageous position in the canopy. Males identified as dominant enjoyed greater social access to the resident female and monopolized copulations. These results suggest that gibbons possess the psycho-social flexibility to regulate intra-sexual aggression and live in multi-male social units under certain social conditions. I discuss the effects that relatedness between males and female choice have in determining this grouping pattern, and the role of male intolerance in the maintenance of primate mating systems. © 2015 Wiley Periodicals, Inc.

Heat stress affects male reproduction in a parasitoid wasp.

PubMed

Nguyen, Thanh Manh; Bressac, Christophe; Chevrier, Claude

2013-03-01

In insects, reproductive success and survival are affected by temperature. Reproduction is more sensitive than other physiological traits. While the effects of heat stress on females are well known, the effects on males are less clear. Hymenopteran parasitoids are valuable for studying the consequences of heat stress on male reproduction. In these species, through arrhenotoquous parthenogenesis, the sex ratio of the offspring is directly dependent on the sperm stock acquired by females during copulation. In the lab, heat temperature treatments (32-44°C) were applied for 3 days in the pupal stage of Anisopteromalus calandrae males, and development was completed at 30°C. Three different effects were observed depending on the temperature: mortality above 42°C, sterility of emerging males at 40°C, and sub-fertility at 38°C. This sub-fertility is characterized by a dramatic decrease in male sperm supplies, of up to 7% compared to control males. In the course of ageing, the sperm stock of sub-fertile males increases but never reaches the level of control males. Survival was significantly higher in control (30°C) males than those treated at 38°C. Male mating ability was similar whatever the treatment (control and 38°C), but females mated with 38°C-treated males stored 100 times less sperm on average than those mated with control males. The offspring sex ratio of females mated with 38°C-treated males was strongly male biased. The physiological mechanisms are as yet unknown. The relationship between temperature, sperm stock and sex ratio should be taken into account in the management of parasitoids for integrated pest management. Copyright © 2012 Elsevier Ltd. All rights reserved.

Male Zuska's disease.

PubMed

Johnson, Shepard P; Kaoutzanis, Christodoulos; Schaub, George A

2014-04-04

Subareolar abscess of the male breast is a rare condition, which can be complicated by a fistula from the areolar skin into a lactiferous duct. In 1951, Zuska et al first characterised this entity in women. Literature on mammillary fistulas in men is scarce and therefore standardisation of treatment does not exist. We present two cases of recurrent subareolar abscesses with draining fistulas. Both patients were successfully treated by complete excision of the lactiferous duct fistula, and continue to do well with no evidence of disease recurrence. When male patients present with a draining subareolar abscess, one should have a high index of suspicion for a mammillary fistula. Failure to identify and surgically excise the fistula may lead to recurrence of the abscess and prolonged morbidity. The most effective management of this uncommon entity includes complete excision of the lactiferous duct fistula.

Male breast cancer in Tripoli, Libya.

PubMed

El-Habbash, Manal M; Alwindi, Abukris A

2009-08-01

To study the epidemiology, characteristics, and survival of male breast cancer patients. This non-randomized retrospective study includes male patients with breast cancer confirmed by biopsy. A total of 1568 breast cancer patients were registered in the Oncology Department, Tripoli Medical Center, Tripoli, Libya between January 1990 to June 2008. Twenty-two patients were male (1.4%). The mean age of male breast cancer patients was 61 years. They tend to have advanced local disease, as 65% of them were tumor (T)3 and T4, and 93.3% have positive lymph nodes. The preferred surgical treatment was mastectomy and axillary clearance in 65%, and 85% had invasive duct carcinoma. Regarding hormone receptor status, 70% were estrogen and progesterone positive. A total of 71% received chemotherapy as anthracycline based. During follow up, the overall recurrence rate was 47%. The bone was the most common site of relapse (37.5%). Overall survival rate was 82.4% at first, 76.5% at second, and 57% at fifth year. Two patients were brothers, and one of them developed multiple myeloma during follow up. In comparison to female patients with breast cancer, male patients are older, and have more advanced and more hormone positive disease.

Male pregnancy and biparental immune priming.

PubMed

Roth, Olivia; Klein, Verena; Beemelmanns, Anne; Scharsack, Jörn P; Reusch, Thorsten B H

2012-12-01

In vertebrates, maternal transfer of immunity via the eggs or placenta provides offspring with crucial information on prevailing pathogens and parasites. Males contribute little to such transgenerational immune priming, either because they do not share the environment and parasite pressure of the offspring or because sperm are too small for transfer of immunity. In the teleost group of Syngnathids (pipefish, seahorses, and sea dragons), males brood female eggs in a placenta-like structure. Such sex-role-reversed species provide a unique opportunity to test for adaptive plasticity in immune transfer. Here, males and females should both influence offspring immunity. We experimentally tested paternal effects on offspring immunity by examining immune cell proliferation and immune gene expression. Maternal and paternal bacterial exposure induced offspring immune defense 5 weeks after hatching, and this effect persisted in 4-month-old offspring. For several offspring immune traits, double parental exposure (maternal and paternal) enhanced the response, whereas for another group of immune traits, the transgenerational induction already took place if only one parent was exposed. Our study shows that sex role reversal in connection with male pregnancy opens the door for biparental influences on offspring immunity and may represent an additional advantage for the evolution of male pregnancy.

Amyloid beta precursor protein regulates male sexual behavior.

PubMed

Park, Jin Ho; Bonthius, Paul J; Tsai, Houng-Wei; Bekiranov, Stefan; Rissman, Emilie F

2010-07-28

Sexual behavior is variable between individuals, ranging from celibacy to sexual addictions. Within normal populations of individual men, ranging from young to middle aged, testosterone levels do not correlate with libido. To study the genetic mechanisms that contribute to individual differences in male sexual behavior, we used hybrid B6D2F1 male mice, which are a cross between two common inbred strains (C57BL/6J and DBA/2J). Unlike most laboratory rodent species in which male sexual behavior is highly dependent upon gonadal steroids, sexual behavior in a large proportion of these hybrid male mice after castration is independent of gonadal steroid hormones and their receptors; thus, we have the ability to discover novel genes involved in this behavior. Gene expression arrays, validation of gene candidates, and transgenic mice that overexpress one of the genes of interest were used to reveal genes involved in maintenance of male sexual behavior. Several genes related to neuroprotection and neurodegeneration were differentially expressed in the hypothalamus of males that continued to mate after castration. Male mice overexpressing the human form of one of these candidate genes, amyloid beta precursor protein (APP), displayed enhanced sexual behavior before castration and maintained sexual activity for a longer duration after castration compared with controls. Our results reveal a novel and unexpected relationship between APP and male sexual behavior. We speculate that declining APP during normal aging in males may contribute to the loss of sexual function.

Male recombination in Brazilian populations of Drosophila ananassae.

PubMed

Goñi, Beatriz; Matsuda, Muneo; Tobari, Yoshiko N

2016-07-01

With few exceptions, spontaneous crossing over does not normally occur in male Drosophila. Drosophila ananassae males show considerable amounts of crossing over. In wild males of D. ananassae from Asian (2008) and Brazilian populations (1986 and 2007) variable frequencies of meiotic crossing over, estimated from chiasmata counts, suggested the existence of factors controlling male crossing over in these populations. To corroborate for such prediction, we present data on spontaneous recombination in F1 males of D. ananassae heterozygous for chromosomes of the same Brazilian populations (1986) and marker chromosomes using three testers stocks. Mean recombination value was low, although high variability existed between individual frequencies. Recombination frequencies between lines in each tester stock were not significantly different, excepting when the 3ple-px and 3ple-cy testers were compared (p < 0.05). These two testers differ in respect to the regional distribution of crossovers. The occurrence of recombination in chromosomes 2 and 3 in F1 males tested with e(65) se; bri ru was not related, suggesting they are under independent genetic control. Our data are consistent with proposed genetic factors controlling male crossing over in the tester stocks and to the presence of enhancers and suppressors of male crossing over segregating in the Brazilian populations (1986).

Senescent sperm performance in old male birds.

PubMed

Møller, A P; Mousseau, T A; Rudolfsen, G; Balbontín, J; Marzal, A; Hermosell, I; De Lope, F

2009-02-01

Senescence is the deterioration of the phenotype with age caused by negative effects of mutations acting late in life or the physiological deterioration of vital processes. Birds have traditionally been assumed to senescence slowly despite their high metabolic rates, high blood sugar levels and high body temperature. Here we investigate the patterns of age-related performance of sperm of a long distance migrant, the barn swallow Hirundo rustica, varying in age from 1 to 6 years, analysed by the computer-assisted sperm analysis equipment. Sperm showed deteriorating performance in terms of linear movement, track velocity, straight line velocity and reduced proportions of rapidly moving, progressive and motile sperm with age. In a second series of experiments, we assessed performance of sperm from the same males in neutral medium and in medium derived from the reproductive tract of females in an attempt to test if sperm of old males performed relatively better in female medium, as expected from extra-pair paternity being negatively related to male age, but not to female age. Older males showed consistently better performance in female medium than in neutral medium in terms of track velocity, straight line velocity and reduced proportions of rapidly moving, progressive and motile sperm, whereas young males showed better performance in neutral medium. These results provide evidence of declining sperm performance for important reproductive variables not only with age, but also with the sperm of old males performing differentially better in female medium than young males.

Male Reproductive Cancers and Infertility: A Mutual Relationship

PubMed Central

Tvrda, Eva; Agarwal, Ashok; Alkuhaimi, Nawaf

2015-01-01

Reproductive dysfunction and malignancies related to the male gender represent a serious health concern, whose incidence has significantly risen over the past years. Prior to treatment, testicular or prostate cancer patients often display poor semen characteristics similar to subfertile or infertile patients. This fact is underscored by cases where the malignancy is often diagnosed in males who undergo a general fertility screening. This review aims to examine the associations between male infertility and reproductive cancers focusing on common etiologies and biological mechanisms underlining these pathologies. Furthermore, we discuss compelling epidemiological data hypothesizing that male reproductive failure may act as a precursor of future andrological malignancies, including testicular or prostate cancer, thus providing a stimulus for a more specific research in male reproductive health and emphasizing the importance of this relation for physicians taking care of male patients with a reproductive disease. PMID:25837470

Male Hormonal Contraception: Looking Back and Moving Forward

PubMed Central

Roth, Mara Y.; Page, Stephanie T.; Bremner, William J.

2015-01-01

Despite numerous contraceptive options available to women, approximately half of all pregnancies in the United States and worldwide are unplanned. Women and men support the development of reversible male contraception strategies, but none have been brought to market. Herein we review the physiologic basis for male hormonal contraception, the history of male hormonal contraception development, currents agents in development, as well as the potential risks and benefits of male hormonal contraception for men. PMID:26453296

Low Testosterone Correlates with Delayed Development in Male Orangutans

PubMed Central

Emery Thompson, Melissa; Zhou, Amy; Knott, Cheryl D.

2012-01-01

Male orangutans (Pongo spp.) display an unusual characteristic for mammals in that some adult males advance quickly to full secondary sexual development while others can remain in an adolescent-like form for a decade or more past the age of sexual maturity. Remarkably little is understood about how and why differences in developmental timing occur. While fully-developed males are known to produce higher androgen levels than arrested males, the longer-term role of steroid hormones in male life history variation has not been examined. We examined variation in testosterone and cortisol production among 18 fully-developed (“flanged”) male orangutans in U.S. captive facilities. Our study revealed that while testosterone levels did not vary significantly according to current age, housing condition, and species origin, males that had undergone precocious development had higher testosterone levels than males that had experienced developmental arrest. While androgen variation had previously been viewed as a state-dependent characteristic of male developmental status, our study reveals that differences in the physiology of early and late developing males are detectable long past the developmental transition and may instead be trait-level characteristics associated with a male’s life history strategy. Further studies are needed to determine how early in life differences in testosterone levels emerge and what consequences this variation may have for male behavioral strategies. PMID:23077585

Is Male Androphilia a Context-Dependent Cross-Cultural Universal?

PubMed

Hames, Raymond; Garfield, Zachary; Garfield, Melissa

2017-01-01

The cross-cultural ethnographic literature has traditionally used the label male "homosexuality" to describe sexual relationships between biological males without considering whether or not the concept encompasses primary sexual attraction to adult males. Although male androphilia seems to be found in all national populations, its universal existence in tribal populations has been questioned. Our goal is to review previous cross-cultural classifications and surveys of male same sex behavior to present a system that does justice to its varied expressions, especially as it is informed by contemporary sexuality research. Previous comparative research does not effectively distinguish male same sex behavior from male androphilia. Using the standard cross-cultural sample (SCCS) as a sampling frame and the ethnographic sources in the human relations area files and elsewhere, we present distributional data on various forms of male same sex behavior. The SCCS is useful because it is designed to be representative of all historically known social formations and the sample is designed to reduce similarities as a consequence of common descent or historical origin as well as reduce the probability of diffusion of sociocultural practices from one culture to another. Our results show that male same sex behavior as well as male androphilia is much more common than previously estimated in the SCCS. With our findings, we make an argument that male androphilia is a context-dependent cross-cultural universal.

New frontiers in nonhormonal male contraception.

PubMed

Cheng, C Yan; Mruk, Dolores D

2010-11-01

The world's population is nearing 6.8 billion, and we are in need of a male contraceptive that is safe, effective, reversible and affordable. Hormonal approaches, which employ different formulations of testosterone administered in combination with other hormones, have shown considerable promise in clinical trials, and they are currently at the forefront of research and development. However, the long-term effects of using hormones throughout a male's reproductive life for contraception are unknown, and it may take decades before this information becomes available. Because of this, many investigators are aiming to bring a nonhormonal male contraceptive to the consumer market. Indeed, there are several distinct but feasible avenues in which fertility can be regulated without affecting the hypothalamus-pituitary-testis axis. In this review, we discuss several approaches for fertility control involving the testis that one day may lead to the development of a nonhormonal male contraceptive. Copyright © 2010 Elsevier Inc. All rights reserved.

Ocean acidification changes the male fitness landscape.

PubMed

Campbell, Anna L; Levitan, Don R; Hosken, David J; Lewis, Ceri

2016-08-17

Sperm competition is extremely common in many ecologically important marine taxa. Ocean acidification (OA) is driving rapid changes to the marine environments in which freely spawned sperm operate, yet the consequences of OA on sperm performance are poorly understood in the context of sperm competition. Here, we investigated the impacts of OA (+1000 μatm pCO2) on sperm competitiveness for the sea urchin Paracentrotus lividus. Males with faster sperm had greater competitive fertilisation success in both seawater conditions. Similarly, males with more motile sperm had greater sperm competitiveness, but only under current pCO2 levels. Under OA the strength of this association was significantly reduced and there were male sperm performance rank changes under OA, such that the best males in current conditions are not necessarily best under OA. Therefore OA will likely change the male fitness landscape, providing a mechanism by which environmental change alters the genetic landscape of marine species.

Ocean acidification changes the male fitness landscape

NASA Astrophysics Data System (ADS)

Campbell, Anna L.; Levitan, Don R.; Hosken, David J.; Lewis, Ceri

2016-08-01

Sperm competition is extremely common in many ecologically important marine taxa. Ocean acidification (OA) is driving rapid changes to the marine environments in which freely spawned sperm operate, yet the consequences of OA on sperm performance are poorly understood in the context of sperm competition. Here, we investigated the impacts of OA (+1000 μatm pCO2) on sperm competitiveness for the sea urchin Paracentrotus lividus. Males with faster sperm had greater competitive fertilisation success in both seawater conditions. Similarly, males with more motile sperm had greater sperm competitiveness, but only under current pCO2 levels. Under OA the strength of this association was significantly reduced and there were male sperm performance rank changes under OA, such that the best males in current conditions are not necessarily best under OA. Therefore OA will likely change the male fitness landscape, providing a mechanism by which environmental change alters the genetic landscape of marine species.

New approaches to male non-hormonal contraception.

PubMed

Nya-Ngatchou, Jean-Jacques; Amory, John K

2013-03-01

A non-hormonal male contraceptive is a contraceptive that does not involve the administration of hormones or hormone blockers. This review will focus on the use of lonidamine derivatives and inhibitors of retinoic acid biosynthesis and function as approaches to male non-hormonal contraception. Two current lonidamine derivatives, adjudin and H2-gamendazole, are in development as male contraceptives. These potent anti-spermatogenic compounds impair the integrity of the apical ectoplasmic specialization, resulting in premature spermiation and infertility. Another approach to male contraceptive development is the inhibition of retinoic acid in the testes, as retinoic acid signaling is necessary for spermatogenesis. The administration of the retinoic acid receptor antagonist BMS-189453 reversibly inhibits spermatogenesis in mice. Similarly, oral dosing of WIN 18,446, which inhibits testicular retinoic acid biosynthesis, effectively contracepts rabbits. Hopefully, one of these approaches to non-hormonal male contraception will prove to be safe and effective in future clinical trials. Copyright © 2013 Elsevier Inc. All rights reserved.

New approaches to male non-hormonal contraception

PubMed Central

Nya-Ngatchou, Jean-Jacques; Amory, John K.

2012-01-01

A non-hormonal male contraceptive is a contraceptive that does not involve the administration of hormones or hormone blockers. This review will focus on the use of lonidamine derivatives and inhibitors of retinoic acid biosynthesis and function as approaches to male non-hormonal contraception. Two current lonidamine derivatives, Adjudin and H2-gamendazole, are in development as male contraceptives. These potent anti-spermatogenic compounds impair the integrity of the apical ectoplasmic specialization, resulting in premature spermiation and infertility. Another approach to male contraceptive development is the inhibition of retinoic acid in the testes, as retinoic acid signaling is necessary for spermatogenesis. The administration of the retinoic acid receptor antagonist BMS-189453 reversibly inhibits spermatogenesis in mice. Similarly, oral dosing of WIN 18,446, which inhibits testicular retinoic acid biosynthesis, effectively contracepts rabbits. Hopefully, one of these approaches to non-hormonal male contraception will prove to be safe and effective in future clinical trials. PMID:22995542

Survivorship of male and female Bactrocera dorsalis in the field and the effect of male annihilation technique

USDA-ARS?s Scientific Manuscript database

Male Annihilation Technique (MAT) is a key component of the Oriental fruit fly Bactrocera dorsalis Hendel (Diptera: Tephritidae) management because of the “strong” attraction of males to the lure methyl eugenol. The optimal application density for MAT has not been investigated for this economically ...

Alternative routes to the leader male role in a multi-level society: follower vs. solitary male strategies and outcomes in hamadryas baboons.

PubMed

Pines, Mathew; Saunders, Julian; Swedell, Larissa

2011-07-01

The nested one-male units (OMUs) of the hamadryas baboon are part of a complex social system in which "leader" males achieve near exclusive mating access by forcibly herding females into permanent consortships. Within this multi-level social system (troops, bands, clans and OMUs) are two types of prereproductive males--the follower and solitary male--whose different trajectories converge on the leader role. Here we compare OMU formation strategies of followers, who associate with a particular OMU and may have social access to females, with those of solitary males, who move freely within the band and do not associate regularly with OMUs. Data were derived from 42 OMU formations (16 by followers and 26 by solitary males) occurring over 8 years in a hamadryas baboon band at the Filoha site in Ethiopia. "Initial units" (IUs) with sexually immature females (IU strategy) were formed by 44% of followers and 46% of solitary males. The remaining followers took over mature females when their leader was deposed (challenge strategy) or disappeared (opportunistic strategy), or via a seemingly peaceful transfer (inheritance strategy). Solitary males took over mature females from other clans and bands, but mainly from old, injured or vanished leaders within their clan (via both the challenge and opportunistic strategies). Former followers of an OMU were more successful at taking over females from those OMUs than any other category of male. Despite this advantage enjoyed by ex-follower leaders, ex-solitary leaders were equally capable of increasing their OMU size at a comparable rate in their first 2 years as a leader. These results demonstrate the potential for males to employ both multiple roles (follower vs. solitary male) and multiple routes (IU, inheritance, challenge, opportunistic) to acquire females and become a leader male in a mating system characterized by female defense polygyny in a competitive arena. © 2011 Wiley-Liss, Inc.

Remote copulation: male adaptation to female cannibalism.

PubMed

Li, Daiqin; Oh, Joelyn; Kralj-Fiser, Simona; Kuntner, Matjaz

2012-08-23

Sexual cannibalism by females and associated male behaviours may be driven by sexual conflict. One such male behaviour is the eunuch phenomenon in spiders, caused by total genital emasculation, which is a seemingly maladaptive behaviour. Here, we provide the first empirical testing of an adaptive hypothesis to explain this behaviour, the remote copulation, in a highly sexually cannibalistic orb-web spider Nephilengys malabarensis. We demonstrate that sperm transfer continues from the severed male organ into female genitals after the male has been detached from copula. Remote copulation increases the total amount of sperm transferred, and thus probably enhances paternity. We conclude that the mechanism may have evolved in response to sexual cannibalism and female-controlled short copulation duration.

Family correlates of male childhood gender disturbance.

PubMed

Rekers, G A; Mead, S L; Rosen, A C; Brigham, S L

1983-03-01

In the context of a review of adult cases of gender disturbance, a clinical study was pursued on the status of fathers, father-substitutes, and older male siblings for 46 boys with deviations in male role development. Significantly fewer male role models were found in the family backgrounds of the severely gender-disturbed boys as compared to the mild-to-moderately gender-disturbed boys. Male childhood gender disturbance was also found to be correlated with a high incidence of psychiatric problems in both the mothers and fathers and with atypical patterns of the boys' involvement with their mothers and fathers, as measured by the Bene-Anthony Family Relations Test and the Rekers Behavior Checklist for Childhood Gender Problems.

Minority Male Mentoring: A Program Evaluation

ERIC Educational Resources Information Center

Deas, Antoine T.

2017-01-01

This study analyzed the effectiveness of a minority male mentoring program at a public two-year institution of higher education in South Carolina. To assist in investigating the successfulness of African American males at the institution, data regarding graduation rates, grade point averages, developmental course completion, and campus involvement…

Male Reproductive Toxicology: Environmental Exposures vs Reproductive Competence

EPA Science Inventory

Like the lecture this chapter begins with an overview of male reproductive biology and transitions into male reproductive toxicology. It ends with a brief discussion of the strengths and weaknesses in male reproductive toxicology and epidemiology today. This chapter is highly il...

Sexual selection favours male parental care, when females can choose

PubMed Central

Alonzo, Suzanne H.

2012-01-01

Explaining the evolution of male care has proved difficult. Recent theory predicts that female promiscuity and sexual selection on males inherently disfavour male care. In sharp contrast to these expectations, male-only care is often found in species with high extra-pair paternity and striking variation in mating success, where current theory predicts female-only care. Using a model that examines the coevolution of male care, female care and female choice; I show that inter-sexual selection can drive the evolution of male care when females are able to bias mating or paternity towards parental males. Surprisingly, female choice for parental males allows male care to evolve despite low relatedness between the male and the offspring in his care. These results imply that predicting how sexual selection affects parental care evolution will require further understanding of why females, in many species, either do not prefer or cannot favour males that provide care. PMID:22171082

Parental physical abuse and sexual orientation in males.

PubMed

Harry, J

1989-06-01

Because male homosexuals have usually been found to have poorer relationships with their fathers than male heterosexuals, and because children who are disappointments to their parents are more likely to be physically abused than other children, it was hypothesized that gays are more likely than heterosexual men to have been physically abused by parents. This hypothesis was tested comparing 17 gay male college students and 67 heterosexual male college students. Gay males were found to have been more abused during adolescence. Abuse was related to a history of childhood femininity, to having poor relationships with fathers, and to having engaged in gay sex during adolescence. A history of childhood femininity and engaging in gay sex may provoke parental abuse.

Proteomic Analysis of Male-Fertility Restoration in CMS Onion

USDA-ARS?s Scientific Manuscript database

The production of hybrid-onion seed is dependent on cytoplasmic-genic male sterility (CMS) systems. For the most commonly used CMS, male-sterile (S) cytoplasm interacts with a dominant allele at one nuclear male-fertility restoration locus (Ms) to condition male fertility. We are using proteomics ...

Is male rhesus macaque red color ornamentation attractive to females?

PubMed Central

Dubuc, Constance; Allen, William L.; Maestripieri, Dario; Higham, James P.

2014-01-01

Male sexually-selected traits can evolve through different mechanisms: conspicuous and colorful ornaments usually evolve through inter-sexual selection, while weapons usually evolve through intra-sexual selection. Male ornaments are rare among mammals in comparison to birds, leading to the notion that female mate choice generally plays little role in trait evolution in this taxon. Supporting this view, when ornaments are present in mammals they typically indicate social status and are products of male-male competition. This general mammalian pattern, however, may not apply to rhesus macaques (Macaca mulatta). Males of this species display conspicuous skin coloration, but this expression is not correlated to dominance rank, and is therefore unlikely to have evolved due to male-male competition. Here, we investigate whether male color expression influences female proceptivity towards males in the Cayo Santiago free-ranging rhesus macaque population. We collected face images of 24 adult males varying in dominance rank and age at the peak of the mating season, and modeled these to rhesus macaque visual perception. We also recorded female socio-sexual behaviors towards these males. Results show that dark red males received more sexual solicitations, by more females, than pale pink ones. Together with previous results, our study suggests that male color ornaments are more likely to be a product of inter- rather than intra-sexual selection. This may especially be the case in rhesus macaques due to the particular characteristics of male-male competition in this species. PMID:25246728

EGFR ligands exert diverging effects on male reproductive organs.

PubMed

Schneider, Marlon R; Gratao, Ana A; Dahlhoff, Maik; Boersma, Auke; Hrabé de Angelis, Martin; Hoang-Vu, Cuong; Wolf, Eckhard; Klonisch, Thomas

2010-02-01

While the EGFR and most of its ligands are expressed in the male reproductive tract, their functions in male reproduction are poorly understood. Interestingly, male transgenic mice overexpressing EGF are sterile, and transgenic mice overexpressing TGFA, another EGFR ligand, show an enlarged coagulation gland (anterior prostate) due to severe hyperplasia with focal dysplasia. We studied the male reproductive tract of transgenic mice overexpressing betacellulin (BTC-tg) under the control of a promoter conferring widespread transgene expression. Despite strong overexpression of BTC in different parts of the male reproductive tract, the gross appearance and histology of the reproductive organs of BTC-tg males were normal and the same were true for sperm parameters and the in vitro fertilization rate. Collectively, our findings demonstrate that excess of BTC exerts no deleterious effects on the structure or function of the male reproductive tract in mice and indicates unique, non-overlapping functions of specific EGFR ligands in male reproduction. Copyright 2009 Elsevier Inc. All rights reserved.

Genetic complexity underlying hybrid male sterility in Drosophila.

PubMed

Sawamura, Kyoichi; Roote, John; Wu, Chung-I; Yamamoto, Masa-Toshi

2004-02-01

Recent genetic analyses of closely related species of Drosophila have indicated that hybrid male sterility is the consequence of highly complex synergistic effects among multiple genes, both conspecific and heterospecific. On the contrary, much evidence suggests the presence of major genes causing hybrid female sterility and inviability in the less-related species, D. melanogaster and D. simulans. Does this contrast reflect the genetic distance between species? Or, generally, is the genetic basis of hybrid male sterility more complex than that of hybrid female sterility and inviability? To clarify this point, the D. simulans introgression of the cytological region 34D-36A to the D. melanogaster genome, which causes recessive male sterility, was dissected by recombination, deficiency, and complementation mapping. The 450-kb region between two genes, Suppressor of Hairless and snail, exhibited a strong effect on the sterility. Males are (semi-)sterile if this region of the introgression is made homozygous or hemizygous. But no genes in the region singly cause the sterility; this region has at least two genes, which in combination result in male sterility. Further, the males are less fertile when heterozygous with a larger introgression, which suggests that dominant modifiers enhance the effects of recessive genes of male sterility. Such an epistatic view, even in the less-related species, suggests that the genetic complexity is special to hybrid male sterility.

Genetic complexity underlying hybrid male sterility in Drosophila.

PubMed Central

Sawamura, Kyoichi; Roote, John; Wu, Chung-I; Yamamoto, Masa-Toshi

2004-01-01

Recent genetic analyses of closely related species of Drosophila have indicated that hybrid male sterility is the consequence of highly complex synergistic effects among multiple genes, both conspecific and heterospecific. On the contrary, much evidence suggests the presence of major genes causing hybrid female sterility and inviability in the less-related species, D. melanogaster and D. simulans. Does this contrast reflect the genetic distance between species? Or, generally, is the genetic basis of hybrid male sterility more complex than that of hybrid female sterility and inviability? To clarify this point, the D. simulans introgression of the cytological region 34D-36A to the D. melanogaster genome, which causes recessive male sterility, was dissected by recombination, deficiency, and complementation mapping. The 450-kb region between two genes, Suppressor of Hairless and snail, exhibited a strong effect on the sterility. Males are (semi-)sterile if this region of the introgression is made homozygous or hemizygous. But no genes in the region singly cause the sterility; this region has at least two genes, which in combination result in male sterility. Further, the males are less fertile when heterozygous with a larger introgression, which suggests that dominant modifiers enhance the effects of recessive genes of male sterility. Such an epistatic view, even in the less-related species, suggests that the genetic complexity is special to hybrid male sterility. PMID:15020468

Factors affecting the reproductive success of dominant male meerkats.

PubMed

Spong, Göran F; Hodge, Sarah J; Young, Andrew J; Clutton-Brock, Tim H

2008-05-01

Identifying traits that affect the reproductive success of individuals is fundamental for our understanding of evolutionary processes. In cooperative breeders, a dominant male typically restricts mating access to the dominant female for extended periods, resulting in pronounced variation in reproductive success among males. This may result in strong selection for traits that increase the likelihood of dominance acquisition, dominance retention and reproductive rates while dominant. However, despite considerable research on reproductive skew, few studies have explored the factors that influence these three processes among males in cooperative species. Here we use genetic, behavioural and demographic data to investigate the factors affecting reproductive success in dominant male meerkats (Suricata suricatta). Our data show that dominant males sire the majority of all offspring surviving to 1 year. A male's likelihood of becoming dominant is strongly influenced by age, but not by weight. Tenure length and reproductive rate, both important components of dominant male reproductive success, are largely affected by group size and composition, rather than individual traits. Dominant males in large groups have longer tenures, but after this effect is controlled, male tenure length also correlates negatively to the number of adult females in the group. Male reproductive rate also declines as the number of intra- and extra-group competitors increases. As the time spent in the dominant position and reproductive rate while dominant explain > 80% of the total variance in reproductive success, group composition thus has major implications for male reproductive success.

The visible human male: a technical report.

PubMed Central

Spitzer, V; Ackerman, M J; Scherzinger, A L; Whitlock, D

1996-01-01

The National Library of Medicine's Visible Human Male data set consists of digital magnetic resonance (MR), computed tomography (CT), and anatomic images derived from a single male cadaver. The data set is 15 gigabytes in size and is available from the National Library of Medicine under a no-cost license agreement. The history of the Visible Human Male cadaver and the methods and technology to produce the data set are described. PMID:8653448

Differences in nutrient intakes and physical activity levels of Japanese and Australian Caucasian males living in Australia and Japanese males living in Japan.

PubMed

Kagawa, Masaharu; Saito, Yoko; Kerr, Deborah; Uchida, Hayato; Binns, Colin W

2006-01-01

The aim of the study was to determine the nutritional status and nutrient intakes of young Japanese males living in Australia and compared with Japanese males living in Japan and Australian Caucasian males. Four-day dietary records were obtained from 65 Japanese living in Australia (JA), 81 Japanese living in Japan (JJ), and 70 Australian Caucasian males (AA) aged 18-30 years old, together with body composition and physical activity level assessments using anthropometry and the questionnaire. Australian males were significantly taller and heavier than the Japanese counterparts and also showed a greater percent body fat (%BF) and height-corrected sum of skinfolds compared with Japanese males living in Japan (%BF: JJ = 16.6 +/- 5.2, AA = 18.7 +/- 5.6; height corrected sum of skinfolds: JJ = 78.8 +/- 37.3, AA = 96.0 +/- 39.5) (P<0.05). A greater proportion of Australian Caucasian males (98.6%) were involved in vigorous physical exercise than Japanese males (JA = 72.3%; JJ = 85.2%). The JA group consumed a greater amount of energy from protein and fat sources as well as greater calcium, iron, dietary fibre and niacin equivalents intakes than the JJ group (P<0.05). The results suggest that Japanese males living in Australia consumed more energy-dense westernised diet than Japanese males living in Japan. Because of lower physical activity level than Australian males, consumption of energy-dense diet may increase the risk of weight gain among Japanese males who stay in Australia for a long-term.

Male and Female Dominance in Communication.

ERIC Educational Resources Information Center

Octigan, Mary Withrow

This study explores male/female patterns of dominance in dyadic speech communication in order to determine the influence of speaker's sex, speaker's commitment to the women's movement, and observer feedback on those patterns. College students (30 males and 30 females) responded to an "attitudes-toward-women" questionnaire and were classified as…

Sex-Role Affiliation among Male Alcoholics.

ERIC Educational Resources Information Center

Penick, Elizabeth C.; And Others

1984-01-01

Compared sex role attributes of male alcoholic veterans to those of 81 nonalcoholic veterans and 386 college students. Results showed male alcoholics were sex-typed more frequently as feminine than masculine. Results were interpreted as a consequence, not a cause of the disorder and were considered reversible with sustained sobriety. (JAC)

Looking at the Male Librarian Stereotype.

ERIC Educational Resources Information Center

Dickinson, Thad E.

2002-01-01

Discussion of library profession stereotypes focuses on academic male librarians. Topics include the position of the early academic librarians and the environment in which they worked; the beginnings of reference service; women in academic libraries; men in a feminized profession; and current images of male librarians in motion pictures and…

Male Zuska's disease

PubMed Central

Johnson, Shepard P; Kaoutzanis, Christodoulos; Schaub, George A

2014-01-01

Subareolar abscess of the male breast is a rare condition, which can be complicated by a fistula from the areolar skin into a lactiferous duct. In 1951, Zuska et al first characterised this entity in women. Literature on mammillary fistulas in men is scarce and therefore standardisation of treatment does not exist. We present two cases of recurrent subareolar abscesses with draining fistulas. Both patients were successfully treated by complete excision of the lactiferous duct fistula, and continue to do well with no evidence of disease recurrence. When male patients present with a draining subareolar abscess, one should have a high index of suspicion for a mammillary fistula. Failure to identify and surgically excise the fistula may lead to recurrence of the abscess and prolonged morbidity. The most effective management of this uncommon entity includes complete excision of the lactiferous duct fistula. PMID:24706699

Seasonal variation in male alternative reproductive tactics.

PubMed

Monroe, M J; Amundsen, T; Utne-Palm, A C; Mobley, K B

2016-12-01

Genetic parentage analyses reveal considerable diversity in alternative reproductive behaviours (e.g. sneaking) in many taxa. However, little is known about whether these behaviours vary seasonally and between populations. Here, we investigate seasonal variation in male reproductive behaviours in a population of two-spotted gobies (Gobiusculus flavescens) in Norway. Male two-spotted gobies guard nests, attract females and care for fertilized eggs. We collected clutches and nest-guarding males early and late in the breeding season in artificial nests and used microsatellite markers to reconstruct parentage from a subset of offspring from each nest. We hypothesized that mating, reproductive success and sneaking should be more prevalent early in the breeding season when competition for mates among males is predicted to be higher. However, parentage analyses revealed similar values of mating, reproductive success and high frequencies of successful sneaking early (30% of nests) and late (27% of nests) in the season. We also found that multiple females with eggs in the same nest were fertilized by one or more sneaker males, indicating that some males in this population engage in a satellite strategy. We contrast our results to previous work that demonstrates low levels of cuckoldry in a population in Sweden. Our results demonstrate marked stability in both the genetic mating system and male alternative reproductive tactics over the breeding season. However, sneaking rates may vary geographically within a species, likely due to local selection influencing ecological factors encountered at different locations. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Lifestyle causes of male infertility.

PubMed

Durairajanayagam, Damayanthi

2018-03-01

To examine the potential effects of lifestyle factors on male reproductive health. Evidence of a global decline in human sperm quality over recent decades has been accumulating. Environmental, occupational, and modifiable lifestyle factors may contribute to this decline. This review focuses on key lifestyle factors that are associated with male infertility such as smoking cigarettes, alcohol intake, use of illicit drugs, obesity, psychological stress, advanced paternal age, dietary practices, and coffee consumption. Other factors such as testicular heat stress, intense cycling training, lack of sleep and exposure to electromagnetic radiation from mobile phone use are briefly discussed. A comprehensive literature search was performed to identify and synthesise all relevant information, mainly from within the last decade, on the major lifestyle factors associated with male infertility and semen quality. Database searches were limited to reports published in English only. A manual search of bibliographies of the reports retrieved was conducted to identify additional relevant articles. In all, 1012 articles were identified from the database search and after reviewing the titles and abstract of the reports, 104 articles met the inclusion criteria. Of these, 30 reports were excluded as the full-text could not be retrieved and the abstract did not have relevant data. The remaining 74 reports were reviewed for data on association between a particular lifestyle factor and male infertility and were included in the present review. The major lifestyle factors discussed in the present review are amongst the multiple potential risk factors that could impair male fertility. However, their negative impact may well be mostly overcome by behaviour modification and better lifestyle choices. Greater awareness and recognition of the possible impact of these lifestyle factors are important amongst couples seeking conception.

Psychological aspects of male fertility treatment.

PubMed

Mikkelsen, Alice Toft; Madsen, Svend Aage; Humaidan, Peter

2013-09-01

To explore and to identify the possible need for psychological communicative support in men undergoing fertility treatment. Male infertility affects many aspects of a man's life and may cause a life crisis. Although infertility treatment is now commonplace in men, they often feel remote and disconnected from the treatment process. A descriptive survey. A questionnaire with structured and open-ended questions was completed by 210 Danish men undergoing fertility treatment. The questionnaire covered three issues: individual perception of male infertility, gender equality issues, and communication with health professionals in the clinic. Data were collected during 2008. Of the participants, 28% believed that their reduced sperm quality affected their perception of masculinity. 46% stated that equal involvement between partners was a very important element of the treatment; however, 63% said that the health professionals communicated primarily with their female partner. Finally, 62% found that there was a need for a deeper dialogue with the nurses concerning male infertility and 72% lacked information about the psychological consequences of male infertility. In general, participants wanted a more open and balanced dialogue about infertility treatment and the role of the male partner during this process. Infertile men want health professionals to view them on equal terms with their partner. When treating the infertile man, there is a further need to develop more inclusive communication skills. © 2012 Blackwell Publishing Ltd.

Male circumcision and risk of male-to-female HIV-1 transmission: a multinational prospective study in African HIV-1-serodiscordant couples.

PubMed

Baeten, Jared M; Donnell, Deborah; Kapiga, Saidi H; Ronald, Allan; John-Stewart, Grace; Inambao, Mubiana; Manongi, Rachel; Vwalika, Bellington; Celum, Connie

2010-03-13

Male circumcision reduces female-to-male HIV-1 transmission risk by approximately 60%. Data assessing the effect of circumcision on male-to-female HIV-1 transmission are conflicting, with one observational study among HIV-1-serodiscordant couples showing reduced transmission but a randomized trial suggesting no short-term benefit of circumcision. Data collected as part of a prospective study among African HIV-1-serodiscordant couples were analyzed for the relationship between circumcision status of HIV-1-seropositive men and risk of HIV-1 acquisition among their female partners. Circumcision status was determined by physical examination. Cox proportional hazards analysis was used. A total of 1096 HIV-1-serodiscordant couples in which the male partner was HIV-1-infected were followed for a median of 18 months; 374 (34%) male partners were circumcised. Sixty-four female partners seroconverted to HIV-1 (incidence 3.8 per 100 person-years). Circumcision of the male partner was associated with a nonstatistically significant approximately 40% lower risk of HIV-1 acquisition by the female partner (hazard ratio 0.62, 95% confidence interval 0.35-1.10, P = 0.10). The magnitude of this effect was similar when restricted to the subset of HIV-1 transmission events confirmed by viral sequencing to have occurred within the partnership (n = 50, hazard ratio 0.57, P = 0.11), after adjustment for male partner plasma HIV-1 concentrations (hazard ratio 0.60, P = 0.13), and when excluding follow-up time for male partners who initiated antiretroviral therapy (hazard ratio 0.53, P = 0.07). Among HIV-1-serodiscordant couples in which the HIV-1-seropositive partner was male, we observed no increased risk and potentially decreased risk from circumcision on male-to-female transmission of HIV-1.

Thriving Latino Males in Selective Predominantly White Institutions

ERIC Educational Resources Information Center

Pérez, David; Sáenz, Victor B.

2017-01-01

Researchers focus disproportionately on the underperformance of Latino males in higher education. In response to this research gap, this study explores how Latino males conceptualized and embodied success at selective, predominantly White institutions. Using qualitative data available from "The National Study on Latino Male Achievement in…

The Priorities of Iranian Male Adolescents Health Needs.

PubMed

Zare, Elham; Simbar, Masoumeh; Shahhosseini, Zohreh; Alavi Majd, Hamid

2017-07-01

Health in the adolescence period guarantees the next generation's health. The assessment of health needs is the first stage for the implementation of health promotion interventions. This study aimed to assess the priorities of male adolescent's health needs in Tehran, Iran, in year 2015. This cross-sectional correlational study was conducted with 1,200 male adolescents aged between 13 and 18 years. Single male adolescents studying in public guidance and high schools in Tehran, Iran, in year 2015 were chosen using a random multistage sampling method. Data were collected using the male adolescent health need assessment scale. The data were analyzed using descriptive and inferential statistics. It was found that while the lowest score was for the domain of sexual health, other domains had average or higher than average scores. More attention should be paid to the sexual health needs of male adolescents. Policy makers need to design strategies that help meet the health needs of male adolescents.

The Petit Rat (pet/pet), a New Semilethal Mutant Dwarf Rat with Thymic and Testicular Anomalies

PubMed Central

Chiba, Junko; Suzuki, Katsushi; Suzuki, Hiroetsu

2008-01-01

The petit rat (pet/pet) is a recently discovered semilethal mutant dwarf. The neonatal pet/pet rats had a low body weight and small thymus and testis. During the first 3 d after birth, 50% of the male and 80% of the female pet/pet pups were lost or found dead. Surviving pet/pet rats showed marked retardation of postnatal growth, and their body weights were 41% (female rats) and 32% (male rats) of those of normal rats at the adult stage. The pet/pet rats exhibited proportional dwarfism, and their longitudinal bones were shorter than those of controls without skeletal malformations. Most organs of male pet/pet rats, especially the thymus, testis, adipose tissue surrounding the kidney, and accessory sex organs, weighed markedly less at 140 d of age than did those of their normal counterparts. The thymus of pet/pet rats was small with abnormal thymic follicles. Testes from pet/pet rats exhibited 2 patterns of abnormal histology. Spermatogenesis was present in testes that were only slightly anomalous, but the seminiferous tubules were reduced in diameter. In severely affected testes, most of the seminiferous tubules showed degeneration, and interstitial tissue was increased. Plasma growth hormone concentrations did not differ between pet/pet and normal male rats. The dwarf phenotype of pet/pet rats was inherited as an autosomal recessive trait. These results indicate that the pet/pet rat has a semilethal growth-hormone-independent dwarf phenotype that is accompanied by thymic and testicular anomalies and low birth weight. PMID:19149412

The petit rat (pet/pet), a new semilethal mutant dwarf rat with thymic and testicular anomalies.

PubMed

Chiba, Junko; Suzuki, Katsushi; Suzuki, Hiroetsu

2008-12-01

The petit rat (pet/pet) is a recently discovered semilethal mutant dwarf. The neonatal pet/pet rats had a low body weight and small thymus and testis. During the first 3 d after birth, 50% of the male and 80% of the female pet/pet pups were lost or found dead. Surviving pet/pet rats showed marked retardation of postnatal growth, and their body weights were 41% (female rats) and 32% (male rats) of those of normal rats at the adult stage. The pet/pet rats exhibited proportional dwarfism, and their longitudinal bones were shorter than those of controls without skeletal malformations. Most organs of male pet/pet rats, especially the thymus, testis, adipose tissue surrounding the kidney, and accessory sex organs, weighed markedly less at 140 d of age than did those of their normal counterparts. The thymus of pet/pet rats was small with abnormal thymic follicles. Testes from pet/pet rats exhibited 2 patterns of abnormal histology. Spermatogenesis was present in testes that were only slightly anomalous, but the seminiferous tubules were reduced in diameter. In severely affected testes, most of the seminiferous tubules showed degeneration, and interstitial tissue was increased. Plasma growth hormone concentrations did not differ between pet/pet and normal male rats. The dwarf phenotype of pet/pet rats was inherited as an autosomal recessive trait. These results indicate that the pet/pet rat has a semilethal growth-hormone-independent dwarf phenotype that is accompanied by thymic and testicular anomalies and low birth weight.

Male Anorexia Nervosa: A New Focus.

ERIC Educational Resources Information Center

Crosscope-Happel, Cindy; Hutchins, David E.; Getz, Hildy G.; Hayes, Gerald L.

2000-01-01

Although anorexia nervosa affects over one million males yearly, it is often misdiagnosed or overlooked by mental health and medical practitioners. This article brings the problem to the forefront and outlines features that are unique to these males. Greater recognition of the disorder can lead to more accurate diagnoses and, subsequently, better…

Remote copulation: male adaptation to female cannibalism

PubMed Central

Li, Daiqin; Oh, Joelyn; Kralj-Fišer, Simona; Kuntner, Matjaž

2012-01-01

Sexual cannibalism by females and associated male behaviours may be driven by sexual conflict. One such male behaviour is the eunuch phenomenon in spiders, caused by total genital emasculation, which is a seemingly maladaptive behaviour. Here, we provide the first empirical testing of an adaptive hypothesis to explain this behaviour, the remote copulation, in a highly sexually cannibalistic orb-web spider Nephilengys malabarensis. We demonstrate that sperm transfer continues from the severed male organ into female genitals after the male has been detached from copula. Remote copulation increases the total amount of sperm transferred, and thus probably enhances paternity. We conclude that the mechanism may have evolved in response to sexual cannibalism and female-controlled short copulation duration. PMID:22298805

Male Reproductive System

MedlinePlus

... sexual intercourse. The male reproductive system also produces sex hormones, which help a boy develop into a sexually mature man during puberty . ... Understanding Early Sexual Development Questions and Answers About Sex Talking to Your ... Torsion For Boys: Trouble "Down There" Boys and Puberty All About ...

Male mate choice influences female promiscuity in Soay sheep.

PubMed

Preston, B T; Stevenson, I R; Pemberton, J M; Coltman, D W; Wilson, K

2005-02-22

In most animal species, males are predicted to compete for reproductive opportunities, while females are expected to choose between potential mates. However, when males' rate of reproduction is constrained, or females vary widely in 'quality', male mate choice is also predicted to occur. Such conditions exist in the promiscuous mating system of feral Soay sheep on St Kilda, Scotland, where a highly synchronized mating season, intense sperm competition and limitations on sperm production constrain males' potential reproductive rate, and females vary substantially in their ability to produce successful offspring. We show that, consistent with predictions, competitive rams focus their mating activity and siring success towards heavier females with higher inclusive fitness. To our knowledge, this is the first time that male mate choice has been identified and shown to lead to assortative patterns of parentage in a natural mammalian system, and occurs despite fierce male-male competition for mates. An additional consequence of assortative mating in this population is that lighter females experience a series of unstable consorts with less adept rams, and hence are mated by a greater number of males during their oestrus. We have thus also identified a novel male-driven mechanism that generates variation in female promiscuity, which suggests that the high levels of female promiscuity in this system are not part of an adaptive female tactic to intensify post-copulatory competition between males.

Nontraditional Black Male Undergraduates: A Call to Action

ERIC Educational Resources Information Center

Goings, Ramon B.

2017-01-01

Institutions of higher education have witnessed an influx of nontraditional Black college students generally, and males specifically. However, there is limited research that investigates the academic and social experiences of nontraditional Black males. As universities seek to improve the academic retention and graduation rates of Black males,…

[The function of ERα in male reproductive system].

PubMed

Dong, Yu-Hang; Wei, Jin-Hua; Li, Zhen

2014-12-01

Estrogen receptors (ERs), including two sub-types ERα and ERβ, belong to the steroid hormone superfamily of nuclear receptors. ERα distributes in the male reproductive system and plays a crucial role in the regulation of male reproduction through estrogen-dependent and -independent ways. In this article, we mainly reviewed the molecular structure, mode of action and location of ERα in the male reproductive system, and explored the mechanism of ERα in regulating the male reproductive system by analyzing different animal models of disrupted ERα.

Male hormonal contraception: looking back and moving forward.

PubMed

Roth, M Y; Page, S T; Bremner, W J

2016-01-01

Despite numerous contraceptive options available to women, approximately half of all pregnancies in the United States and worldwide are unplanned. Women and men support the development of reversible male contraception strategies, but none have been brought to market. Herein we review the physiologic basis for male hormonal contraception, the history of male hormonal contraception development, currents agents in development as well as the potential risks and benefits of male hormonal contraception for men. © 2015 American Society of Andrology and European Academy of Andrology.

Male-male competition and parental care in collared flycatchers (Ficedula albicollis): an experiment controlling for differences in territory quality.

PubMed

Qvarnström, A; Grifffith, S C; Gustafsson, L

2000-12-22

Females are known to benefit from mate choice in several different ways but the relationship between these benefits has received little attention. The quality of resources provided by males, such as nest sites, and paternal care are often assumed to covary positively However, because the location of the nest affects the cost of parental care, these two benefits from mate choice can easily be confounded. To investigate the provisioning ability of successful competitors while controlling for differences in territory quality we removed early-settled pairs of collared flycatchers (Ficedula albicollis) and allowed replacement by later-arriving males or floaters (i.e.'poor competitors'). A control group of early-settled males (i.e. 'good competitors') had their females removed. Females paired to good competitors enjoyed a significantly higher reproductive success and tended to receive more parental assistance from their mates compared with females mated to poor competitors. Thus, some males seem able not only to compete successfully over resources but also to feed their offspring at a relatively higher rate. An alternative explanation, that poor competitors invested less in offspring quality in response to a lower share of paternity, could be rejected. The rate of extra-pair paternity did not differ between the two treatment groups. Our results suggest that male- male competition can sometimes facilitate female choice of superior care-givers. Thus, a female's benefit from choosing a competitive male may not be restricted to the quality of the resource he defends but can also include superior paternal care.

Exclusion of broiler breeder females from male feeders with a male only grill. 1. Behavioral and technical aspects of design and development.

PubMed

Brake, J; Khamidullin, T N; Fisinin, V I

1993-03-01

A series of experiments was conducted in order to develop a feeder grill that would allow broiler breeder males, but not females, to eat. Females are typically excluded from male feeders by increasing the height of the feeder. However, male feeder heights that exclude most females increase the time required for males to consume a given amount of feed 19 to 60%. Typical male feeder height from floor to feeder pan lip in commercial practice is 55 cm, which is about the distance from floor to the head of the male in an erect posture. Females measure about 40 cm in an erect posture. Because the necks of males (8.0 cm) are longer than those of females (6.3 cm), the lip of male feeder pans was extended horizontally 12.7 cm with a wire mesh on the assumption that females could not stretch their necks enough to reach the feed. However, the females learned quickly to perch on the extended lip and eat. Total exclusion of females from the male feeder, regardless of feeder height, was achieved by placing a horizontal upper mesh 5.6 to 10.2 cm above the extended lip, and connecting the upper mesh to the lower extended lip of the feeder with vertical bars spaced 5.1 cm apart. The horizontal upper mesh prevented perching by females and the 5.1-cm spacing of the vertical bars allowed males but not females to reach the feed by inserting their heads and necks up to their shoulders.(ABSTRACT TRUNCATED AT 250 WORDS)

Augmenting effects of gestational arsenite exposure of C3H mice on the hepatic tumors of the F₂ male offspring via the F₁ male offspring.

PubMed

Nohara, Keiko; Okamura, Kazuyuki; Suzuki, Takehiro; Murai, Hikari; Ito, Takaaki; Shinjo, Keiko; Takumi, Shota; Michikawa, Takehiro; Kondo, Yutaka; Hata, Kenichiro

2016-01-01

Gestational exposure can affect the F2 generation through exposure of F1 germline cells. Previous studies reported that arsenite exposure of only F0 females during their pregnancy increases hepatic tumors in the F1 males in C3H mice, whose males are predisposed spontaneously to develop hepatic tumors later in life. The present study addressed the effects of gestational arsenite exposure on tumorigenesis of the F2 males in C3H mice. Expression analysis of several genes in the normal livers at 53 and 80 weeks of age clearly showed significant changes in the F2 males obtained by crossing gestational arsenite-exposed F1 (arsenite-F1) males and females compared to the control F2 males. Some of the changes were shown to occur in a late-onset manner. Then the tumor incidence was assessed at 75-82 weeks of age in the F2 males obtained by reciprocal crossing between the control and arsenite-F1 males and females. The results demonstrated that the F2 males born to arsenite-F1 males developed tumors at a significantly higher rate than the F2 males born to the control F1 males, irrespective of exposure of F1 females. Gene expressions of hepatocellular carcinoma markers β-catenin (CTNNB1) and interleukin-1 receptor antagonist in the tumors were significantly upregulated in the F2 males born to arsenite-F1 males compared to those born to the control F1 males. These results show that arsenite exposure of only F0 pregnant mice causes late-onset changes and augments tumors in the livers of the F2 males by affecting the F1 male offspring. Copyright © 2015 John Wiley & Sons, Ltd.

Reduced fecundity in male ALS gene-carriers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, W.G.; Lustenberger, A.; Lucek, P.R.

1995-11-06

In order to study genetic aspects in multicase families, 89 amyotrophic lateral sclerosis (ALS) and 214 Parkinson disease (PD) kindreds were analyzed in parallel studies. Obligate gene-carriers were identified as described previously. There were fewer children per gene-carrier male (2.42) than per gene-carrier female (3.25, Student`s t-test, P<.0003) for ALS but not for other diseases. The data taken together suggest that fecundity in ALS gene-carriers was reduced in males, possibly as a result of reduced fertility. Since childbearing is usually accomplished well before the onset of neurological symptoms in ALS, and since reduced fecundity was found in male ALS gene-carriers,more » these findings raise the possibility that an ALS gene might have a pleiotrophic effect on fertility in males occurring decades before the onset of neurological symptoms. Evidence is presented linking reactive oxygen species to reduced fertility in males. Alternatively, decreased or nonfunctional androgen receptors could play a role. 22 refs., 1 fig., 2 tabs.« less

[The prevalence of snoring in male pilots].

PubMed

Wang, Wan-er; Zhu, Guang-qing; Zhang, Ji-dong; Li, Rong; Wang, Yan-yan; Zhang, Yu-zhen; Liu, Ju-qin; He, Quan-ying

2008-09-01

To investigate and analysis the prevalence and risk factors of snoring and excessive daytime sleepiness among male pilots. 1108 subjects were derived from a random sample of pilots. They were asked to answer the questions from a questionnaire concerning their snoring and daytime sleepiness, etc. 1054 questionnaire were available for evaluation. The overall prevalence of snoring among male pilots was 51.04% (538/1054), while moderate and severe snorers accounted for 26.28% (227/1054). The prevalence of snoring among male pilots aged over 30 yr was 63.68% (426/669). The prevalence and severity of snoring increase with age and BMI. Age, overweight and obesity, alcohol ingestion and family history of snoring were associated with the prevalence and severity of snoring. There was significant difference in Epworth sleepiness scale scores among without snoring group and various severity of snoring groups (chi2 = 16.948, P < 0.05). The prevalence of snoring is high in male pilots. The Epworth sleepiness scale score increase with increasing degree of snoring. Doctors should pay more attention to snoring in male pilot.

A novel herbicide-inducible male sterility system.

PubMed

Zhang, Jinhui; Zhang, Wenlu; Yen, Yang; Long, Hai; Deng, Guangbing; Pan, Zhifen; Yu, Maoqun

2010-11-01

Heterosis is a phenomenon that first-generation offspring perform better than their parents. Conventional breeding methods have their shortcomings. It would be optimal to construct inducible male sterile plants. We developed a novel system for creating male sterile transgenic plants by downregulating the specific expression of the glyphosate tolerance CP4 EPSPS gene in male reproductive tissues. Transcriptional repression was achieved by manipulating DNA binding proteins with their specific corresponding sites. We transferred the CP4 EPSPS gene driven by a modified CaMV 35S promoter with three tetracycline operator copies in the vicinity of the TATA box and tetracycline repressor gene under the control of an anther-specific promoter Osg6B to Arabidopsis thaliana. As a result, we successfully obtained controllable transgenic plants: the whole plant could tolerate exposure of glyphosate but the male tissue was sensitive. The novel inducible male sterility system is applied and easy to handle, so it might be applicable to a wide range of crop plants. 2010 Society of Chemical Industry

Alpha male replacements and delayed dispersal in crested macaques (Macaca nigra).

PubMed

Marty, Pascal R; Hodges, Keith; Agil, Muhammad; Engelhardt, Antje

2017-07-01

In species with a high male reproductive skew, competition between males for the top dominant position is high and escalated fights are common between competitors. As a consequence, challenges incur potentially high costs. Selection should favor males who time an alpha male challenge to maximize chances of a successful outcome minimizing costs. Despite the importance of alpha male replacements for individual males, we know little about the timing of challenges and the condition of the challenger. We investigated the timing and process of alpha male replacements in a species living in multi-male groups with high male reproductive skew, the crested macaque. We studied four wild groups over 6 years in the Tangkoko Reserve, North Sulawesi, Indonesia, during which 16 alpha male replacements occurred. Although unusual for cercopithecines, male crested macaques delayed their natal dispersal until they attained maximum body mass and therefore fighting ability whereupon they emigrated and challenged the alpha male in another group. Accordingly, all observed alpha male replacements were from outside males. Ours is the first report of such a pattern in a primate species living in multi-male groups. Although the majority of alpha male replacements occurred through direct male-male challenges, many also took place opportunistically (i.e., after the alpha male had already been injured or had left the group). Furthermore, alpha male tenures were very short (averaging ca. 12 months). We hypothesize that this unusual pattern of alpha male replacements in crested macaques is related to the species-specific combination of high male reproductive skew with a large number of males per group. Am. J. Primatol. 79:e22448, 2017. © 2015 The Authors. American Journal of Primatology Published by Wiley Periodicals, Inc. © 2015 The Authors. American Journal of Primatology Published by Wiley Periodicals, Inc.

Professional career development for male nurses.

PubMed

Yang, Cheng-I; Gau, Meei-Ling; Shiau, Shu-Jen; Hu, Wei-Herng; Shih, Fu-Jin

2004-12-01

The aim of this paper is to report a study to: (a) explore Taiwanese male nurses' motivations for becoming a nurse; (b) reveal their professional developmental process in nursing; (c) understand the difficulties hindering their professional development from both professional and gender aspects; and (d) identify the strategies they use to cope with these difficulties. Hindered by historical, cultural, economic and warfare factors, the proportion of male nurses in Taiwan remains low. Taiwanese male nurses' career development process has not been well investigated yet. A descriptive qualitative research design was used, with a convenience sample of 15 male nurses (mean age 30.8 years) with a Bachelor's degree in Nursing Science. Data were collected by semi-structured interviews and analysed by content analysis. Taiwanese male nurses' entrance into the nursing profession involved three phases: pre-study, study and employment. The difficulties encountered during career development were related to the gender expectations of patients and the general public. The nurses received support more from superiors than from colleagues. The strategies they used included (a) improving their professional knowledge and skills to obtain higher levels of satisfaction and better opportunities for promotion; (b) thinking aggressively about job promotion; (c) choosing specialist departments as appropriate environments for graduate study and personal growth; and (d) changing their professional track for personal growth. Based on the nature of nursing work and clinical experiences, Taiwanese male nurses believed that nursing was a profession suitable for both men and women. Their preparation for career development started at the pre-study phase. The major strategies they used were related to a strong desire for personal growth and professional promotion. Finally, a conceptual framework was developed to depict this complex phenomenon.

[Causes and Factors of Male Infertility].

PubMed

Kolesnikova, L I; Kolesnikov, S I; Kurashova, N A; Bairova, T A

2015-01-01

The preservation of reproductive health of the population is an important factor of demographic policy of the state. According to some authors from 14 to 30% of couples of reproductive age suffer from infertility, malefactor in such marriages is detected in more than half of the cases. As you know, in recent years there has been a significant deterioration in the main indicators of reproductive function of men. Increased the number of andrological diseases, morphological disorders of the male reproductive system, almost halved the production of sperm in men of reproductive age. The reason probably lies behind a whole range ofstressfactors, such as medical ignorance, uncontrolled and inappropriate use of medication, metabolic disturbances, lack of vitamins and minerals, the impact of industrial pollutants, as well as the growth of addictive disorders (alcoholism, smoking and drug addiction). The forms of infertility differ according to its etiology and severity from minor changes to complete spermatogenesis dysfunction of the gonads, and can also occur due to genetic disorders. The lack of analysis of the relationship between clinical and genetic-biochemical components in men with infertility makes it impossible to understand the pathogenesis of infertility and to assess the risks of male infertility. High level of current medicine does not always guarantee an identification of the cause of male infertility. The article analyzes data from the review of specialized literature on the diagnosis and etiopathogenesis of male infertility. Frequency and clinical signs of pathology of the male reproductive system depend on the combinatorial effects of environmental influences, manifested most often in mutually reinforcing effect. A combination of several, seemed to be imperceptible factors makes the risk of development of male reproductive pathology very high. This situation compels specialists to conduct comprehensive studies on the men reproductive potential.

Male Teacher Shortage: Black Teachers' Perspectives

ERIC Educational Resources Information Center

Martino, Wayne; Rezai-Rashti, Goli M.

2010-01-01

In this paper the authors draw on the perspectives of black teachers to provide a more nuanced analysis of male teacher shortage. Interviews with two Caribbean teachers in Toronto, Canada, are employed to illuminate the limits of an explanatory framework that foregrounds the singularity of gender as a basis for advocating male teachers as role…

Self-Disclosure in Male-Female Encounters.

ERIC Educational Resources Information Center

Pellegrini, Robert J.; And Others

Male and female subjects identified as very attractive or very unattractive worked in an interview-like situation with a listener of the opposite sex who was presented so as to maximize or minimize his or her natural attractiveness. Intimacy of self-disclosure was found to be significantly greater for females than for males, significantly greater…

Male versus Female Attitudes toward Stuttering

ERIC Educational Resources Information Center

St. Louis, Kenneth O.

2012-01-01

Purpose: The study investigated the extent to which differences existed between public attitudes of males versus females. Method: One hundred adults, 50 males and 50 females, were chosen at random from each of 50 study samples comprising a total of 3371 respondents in a database archive who had completed the "Public Opinion Survey of Human…

Evidence for volatile male-produced pheromone in banana weevilCosmopolites sordidus.

PubMed

Budenberg, W J; Ndiege, I O; Karago, F W

1993-09-01

Females of the banana weevil,Cosmopolites sordidus, were attracted to and made longer visits to live conspecific males, trapped volatiles from males, and dissected male hindguts in a still-air olfactometer. Male weevils were attracted to volatiles trapped from males and made longer visits to live males and volatiles from males. Live females, collected volatiles from females and female hindguts, elicited small or no behavioral responses from either sex. Electroantennogram (EAG) responses from both male and female antennae were elicited by collected volatiles from males and by dichloromethane extracts of male hindguts and bodies but not by surface washes of males. No significant EAG responses were given to equivalent material from females. It is therefore suggested that male banana weevils release an aggregation pheromone via their hindgut.

Plasma kisspeptin levels in male cases with hypogonadism.

PubMed

Kotani, Masato; Katagiri, Fumihiko; Hirai, Tsuyoshi; Kagawa, Jiro

2014-01-01

The hypothalamic hormone kisspeptin (metastin) regulates human reproduction by modulating gonadotropin-releasing hormone (GnRH) secretion. Kisspeptin is detected in peripheral blood, although GnRH is not. In this study, we measured plasma kisspeptin levels in four male cases with hypogonadism and seven normal male controls using enzyme immunoassay (EIA) to elucidate the clinical implications of kisspeptin levels in male hypogonadism. The results showed a variety of plasma kisspeptin levels: 6.0 fmol/mL in a male with isolated hypogonadotropic hypogonadism (IHH), 43.2 fmol/mL in a male with Kallmann's syndrome, 40.7 fmol/mL in a male with azoospermia, 323.2 fmol/mL in a male with hypergonadotropic hypogonadism, and 12.3 ± 2.5 fmol/mL (mean ± SD) in seven normal controls. Except for the case with IHH, the plasma kisspetin levels were elevated in the three cases with Kallmann's syndrome, azoospermia, and hypergonadotropic hypogonadism. The reason why the three cases had high values was their lesions were downstream of the kisspeptin neuron in the hypothalamic-pituitary-gonadal axis, suggesting that elevated kisspeptin levels were implicated in hypothalamic kisspeptin secretion under decreased negative feedback of gonadal steroids. The result that the plasma kisspeptin levels were decreased by gonadotropin therapy in the case with Kallmann's syndrome supported this hypothesis. In conclusion, to measure plasma kisspeptin levels could be useful for better understanding of male hypogonadism.

Mammographic appearances of male breast disease.

PubMed

Appelbaum, A H; Evans, G F; Levy, K R; Amirkhan, R H; Schumpert, T D

1999-01-01

Various male breast diseases have characteristic mammographic appearances that can be correlated with their pathologic diagnoses. Male breast cancer is usually subareolar and eccentric to the nipple. Margins of the lesions are more frequently well defined, and calcifications are rarer and coarser than those occurring in female breast cancer. Gynecomastia usually appears as a fan-shaped density emanating from the nipple, gradually blending into surrounding fat. It may have prominent extensions into surrounding fat and, in some cases, an appearance similar to that of a heterogeneously dense female breast. Although there are characteristic mammographic features that allow breast cancer in men to be recognized, there is substantial overlap between these features and the mammographic appearance of benign nodular lesions. The mammographic appearance of gynecomastia is not similar to that of male breast cancer, but in rare cases, it can mask malignancy. Gynecomastia can be mimicked by chronic inflammation. All mammographically lucent lesions of the male breast appear to be benign, similar to such lesions in the female breast.

Original Research: Metabolic alterations from early life thyroxine replacement therapy in male Ames dwarf mice are transient.

PubMed

Darcy, Justin; Fang, Yimin; Hill, Cristal M; McFadden, Sam; Sun, Liou Y; Bartke, Andrzej

2016-10-01

Ames dwarf mice are exceptionally long-lived due to a Prop1 loss of function mutation resulting in deficiency of growth hormone, thyroid-stimulating hormone and prolactin. Deficiency in thyroid-stimulating hormone and growth hormone leads to greatly reduced levels of circulating thyroid hormones and insulin-like growth factor 1, as well as a reduction in insulin secretion. Early life growth hormone replacement therapy in Ames dwarf mice significantly shortens their longevity, while early life thyroxine (T4) replacement therapy does not. Possible mechanisms by which early life growth hormone replacement therapy shortens longevity include deleterious effects on glucose homeostasis and energy metabolism, which are long lasting. A mechanism explaining why early life T4 replacement therapy does not shorten longevity remains elusive. Here, we look for a possible explanation as to why early life T4 replacement therapy does not impact longevity of Ames dwarf mice. We found that early life T4 replacement therapy increased body weight and advanced the age of sexual maturation. We also find that early life T4 replacement therapy does not impact glucose tolerance or insulin sensitivity, and any deleterious effects on oxygen consumption, respiratory quotient and heat production are transient. Lastly, we find that early life T4 replacement therapy has long-lasting effects on bone mineral density and bone mineral content. We suggest that the transient effects on energy metabolism and lack of effects on glucose homeostasis are the reasons why there is no shortening of longevity after early life T4 replacement therapy in Ames dwarf mice. © 2016 by the Society for Experimental Biology and Medicine.

The male handicap: male-biased mortality explains skewed sex ratios in brown trout embryos.

PubMed

Morán, P; Labbé, L; Garcia de Leaniz, C

2016-12-01

Juvenile sex ratios are often assumed to be equal for many species with genetic sex determination, but this has rarely been tested in fish embryos due to their small size and absence of sex-specific markers. We artificially crossed three populations of brown trout and used a recently developed genetic marker for sexing the offspring of both pure and hybrid crosses. Sex ratios (SR = proportion of males) varied widely one month after hatching ranging from 0.15 to 0.90 (mean = 0.39 ± 0.03). Families with high survival tended to produce balanced or male-biased sex ratios, but SR was significantly female-biased when survival was low, suggesting that males sustain higher mortality during development. No difference in SR was found between pure and hybrid families, but the existence of sire × dam interactions suggests that genetic incompatibility may play a role in determining sex ratios. Our findings have implications for animal breeding and conservation because skewed sex ratios will tend to reduce effective population size and bias selection estimates. © 2016 The Authors.

Coming of Age: African American Male Rites-of-Passage.

ERIC Educational Resources Information Center

Hill, Paul, Jr.

An overview is provided of issues confronting the African American male, along with a strategy to nurture a new generation of African American males. Chapters 1 and 2 focus on the social status and new demographics of the African American male and the external threats that are devastating to the African American male and the African American…

Alpha male replacements and delayed dispersal in crested macaques (Macaca nigra)

PubMed Central

Hodges, Keith; Agil, Muhammad; Engelhardt, Antje

2015-01-01

In species with a high male reproductive skew, competition between males for the top dominant position is high and escalated fights are common between competitors. As a consequence, challenges incur potentially high costs. Selection should favor males who time an alpha male challenge to maximize chances of a successful outcome minimizing costs. Despite the importance of alpha male replacements for individual males, we know little about the timing of challenges and the condition of the challenger. We investigated the timing and process of alpha male replacements in a species living in multi‐male groups with high male reproductive skew, the crested macaque. We studied four wild groups over 6 years in the Tangkoko Reserve, North Sulawesi, Indonesia, during which 16 alpha male replacements occurred. Although unusual for cercopithecines, male crested macaques delayed their natal dispersal until they attained maximum body mass and therefore fighting ability whereupon they emigrated and challenged the alpha male in another group. Accordingly, all observed alpha male replacements were from outside males. Ours is the first report of such a pattern in a primate species living in multi‐male groups. Although the majority of alpha male replacements occurred through direct male‐male challenges, many also took place opportunistically (i.e., after the alpha male had already been injured or had left the group). Furthermore, alpha male tenures were very short (averaging ca. 12 months). We hypothesize that this unusual pattern of alpha male replacements in crested macaques is related to the species‐specific combination of high male reproductive skew with a large number of males per group. Am. J. Primatol. 79:e22448, 2017. © 2015 The Authors. American Journal of Primatology Published by Wiley Periodicals, Inc. PMID:26194621

As Boys Become Men: Learning New Male Roles.

ERIC Educational Resources Information Center

Thompson, Doug

Designed for use in junior and senior high schools, this booklet focuses on the male role stereotype. Each of the eight sections contains activities, student objectives, and background information: (1) "What's Feminine and What's Masculine?" examines male and female sex role stereotypes; (2) "A Real Man" evaluates male role stereotypes; (3) "Men…

Male-mediated developmental toxicity.

PubMed

Anderson, Diana; Schmid, Thomas E; Baumgartner, Adolf

2014-01-01

Male-mediated developmental toxicity has been of concern for many years. The public became aware of male-mediated developmental toxicity in the early 1990s when it was reported that men working at Sellafield might be causing leukemia in their children. Human and animal studies have contributed to our current understanding of male-mediated effects. Animal studies in the 1980s and 1990s suggested that genetic damage after radiation and chemical exposure might be transmitted to offspring. With the increasing understanding that there is histone retention and modification, protamine incorporation into the chromatin and DNA methylation in mature sperm and that spermatozoal RNA transcripts can play important roles in the epigenetic state of sperm, heritable studies began to be viewed differently. Recent reports using molecular approaches have demonstrated that DNA damage can be transmitted to babies from smoking fathers, and expanded simple tandem repeats minisatellite mutations were found in the germline of fathers who were exposed to radiation from the Chernobyl nuclear power plant disaster. In epidemiological studies, it is possible to clarify whether damage is transmitted to the sons after exposure of the fathers. Paternally transmitted damage to the offspring is now recognized as a complex issue with genetic as well as epigenetic components.

Social recognition is context dependent in single male prairie voles

PubMed Central

Zheng, Da-Jiang; Foley, Lauren; Rehman, Asad; Ophir, Alexander G.

2013-01-01

Single males might benefit from knowing the identity of neighbouring males when establishing and defending boundaries. Similarly, males should discriminate between individual females if this leads to more reproductive opportunities. Contextual social cues may alter the value of learning identity. Knowing the identity of competitors that intrude into an animal’s territory may be more salient than knowing the identity of individuals on whose territory an animal is trespassing. Hence, social and environmental context could affect social recognition in many ways. Here we test social recognition of socially monogamous single male prairie voles, Microtus ochrogaster. In experiment 1 we tested recognition of male or female conspecifics and found that males discriminated between different males but not between different females. In experiment 2 we asked whether recognition of males is influenced when males are tested in their own cage (familiar), in a clean cage (neutral) or in the home cage of another male (unfamiliar). Although focal males discriminated between male conspecifics in all three contexts, individual variation in recognition was lower when males were tested in their home cage (in the presence of familiar social cues) compared to when the context lacked social cues (neutral). Experiment 1 indicates that selective pressures may have operated to enhance male territorial behaviour and indiscriminate mate selection. Experiment 2 suggests that the presence of a conspecific cue heightens social recognition and that home-field advantages might extend to social cognition. Taken together, our results indicate social recognition depends on the social and possibly territorial context. PMID:24273328

Social recognition is context dependent in single male prairie voles.

PubMed

Zheng, Da-Jiang; Foley, Lauren; Rehman, Asad; Ophir, Alexander G

2013-11-01

Single males might benefit from knowing the identity of neighbouring males when establishing and defending boundaries. Similarly, males should discriminate between individual females if this leads to more reproductive opportunities. Contextual social cues may alter the value of learning identity. Knowing the identity of competitors that intrude into an animal's territory may be more salient than knowing the identity of individuals on whose territory an animal is trespassing. Hence, social and environmental context could affect social recognition in many ways. Here we test social recognition of socially monogamous single male prairie voles, Microtus ochrogaster . In experiment 1 we tested recognition of male or female conspecifics and found that males discriminated between different males but not between different females. In experiment 2 we asked whether recognition of males is influenced when males are tested in their own cage (familiar), in a clean cage (neutral) or in the home cage of another male (unfamiliar). Although focal males discriminated between male conspecifics in all three contexts, individual variation in recognition was lower when males were tested in their home cage (in the presence of familiar social cues) compared to when the context lacked social cues (neutral). Experiment 1 indicates that selective pressures may have operated to enhance male territorial behaviour and indiscriminate mate selection. Experiment 2 suggests that the presence of a conspecific cue heightens social recognition and that home-field advantages might extend to social cognition. Taken together, our results indicate social recognition depends on the social and possibly territorial context.

Review: neuroestrogen regulation of socio-sexual behavior of males.

PubMed

Ubuka, Takayoshi; Tsutsui, Kazuyoshi

2014-01-01

It is thought that estrogen (neuroestrogen) synthesized by the action of aromatase in the brain from testosterone activates male socio-sexual behaviors, such as aggression and sexual behavior in birds. We recently found that gonadotropin-inhibitory hormone (GnIH), a hypothalamic neuropeptide, inhibits socio-sexual behaviors of male quail by directly activating aromatase and increasing neuroestrogen synthesis in the preoptic area (POA). The POA is thought to be the most critical site of aromatization and neuroestrogen action for the regulation of socio-sexual behavior of male birds. We concluded that GnIH inhibits socio-sexual behaviors of male quail by increasing neuroestrogen concentration beyond its optimal concentration in the brain for expression of socio-sexual behavior. On the other hand, it has been reported that dopamine and glutamate, which stimulate male socio-sexual behavior in birds and mammals, inhibit the activity of aromatase in the POA. Multiple studies also report that the activity of aromatase or neuroestrogen is negatively correlated with changes in male socio-sexual behavior in fish, birds, and mammals including humans. Here, we review previous studies that investigated the role of neuroestrogen in the regulation of male socio-sexual behavior and reconsider the hypothesis that neuroestrogen activates male socio-sexual behavior in vertebrates. It is considered that basal concentration of neuroestrogen is required for the maintenance of male socio-sexual behavior but higher concentration of neuroestrogen may inhibit male socio-sexual behavior.

Review: neuroestrogen regulation of socio-sexual behavior of males

PubMed Central

Ubuka, Takayoshi; Tsutsui, Kazuyoshi

2014-01-01

It is thought that estrogen (neuroestrogen) synthesized by the action of aromatase in the brain from testosterone activates male socio-sexual behaviors, such as aggression and sexual behavior in birds. We recently found that gonadotropin-inhibitory hormone (GnIH), a hypothalamic neuropeptide, inhibits socio-sexual behaviors of male quail by directly activating aromatase and increasing neuroestrogen synthesis in the preoptic area (POA). The POA is thought to be the most critical site of aromatization and neuroestrogen action for the regulation of socio-sexual behavior of male birds. We concluded that GnIH inhibits socio-sexual behaviors of male quail by increasing neuroestrogen concentration beyond its optimal concentration in the brain for expression of socio-sexual behavior. On the other hand, it has been reported that dopamine and glutamate, which stimulate male socio-sexual behavior in birds and mammals, inhibit the activity of aromatase in the POA. Multiple studies also report that the activity of aromatase or neuroestrogen is negatively correlated with changes in male socio-sexual behavior in fish, birds, and mammals including humans. Here, we review previous studies that investigated the role of neuroestrogen in the regulation of male socio-sexual behavior and reconsider the hypothesis that neuroestrogen activates male socio-sexual behavior in vertebrates. It is considered that basal concentration of neuroestrogen is required for the maintenance of male socio-sexual behavior but higher concentration of neuroestrogen may inhibit male socio-sexual behavior. PMID:25352775

Male adolescent sexual and reproductive health care.

PubMed

Marcell, Arik V; Wibbelsman, Charles; Seigel, Warren M

2011-12-01

Male adolescents' sexual and reproductive health needs often go unmet in the primary care setting. This report discusses specific issues related to male adolescents' sexual and reproductive health care in the context of primary care, including pubertal and sexual development, sexual behavior, consequences of sexual behavior, and methods of preventing sexually transmitted infections (including HIV) and pregnancy. Pediatricians are encouraged to address male adolescent sexual and reproductive health on a regular basis, including taking a sexual history, performing an appropriate examination, providing patient-centered and age-appropriate anticipatory guidance, and delivering appropriate vaccinations. Pediatricians should provide these services to male adolescent patients in a confidential and culturally appropriate manner, promote healthy sexual relationships and responsibility, and involve parents in age-appropriate discussions about sexual health with their sons.

Male-male competition, female mate choice and their interaction: determining total sexual selection.

PubMed

Hunt, John; Breuker, Casper J; Sadowski, Jennifer A; Moore, Allen J

2009-01-01

Empirical studies of sexual selection typically focus on one of the two mechanisms of sexual selection without integrating these into a description of total sexual selection, or study total sexual selection without quantifying the contributions of all of the mechanisms of sexual selection. However, this can provide an incomplete or misleading view of how sexually selected traits evolve if the mechanisms of sexual selection are opposing or differ in form. Here, we take a two-fold approach to advocate a direction for future studies of sexual selection. We first show how a quantitative partitioning and examination of sexual selection mechanisms can inform by identifying illustrative studies that describe both male-male competition and female mate choice acting on the same trait. In our sample, the most common trait where this occurred was body size, and selection was typically linear. We found that male-male competition and female mate choice can be reinforcing or opposing, although the former is most common in the literature. The mechanisms of sexual selection can occur simultaneously or sequentially, and we found they were more likely to be opposing when the mechanisms operated sequentially. The degree and timing that these mechanisms interact have important implications for the operation of sexual selection and needs to be considered in designing studies. Our examples highlight where empirical data are needed. We especially lack standardized measures of the form and strength of selection imposed by each mechanism of sexual selection and how they combine to determine total sexual selection. Secondly, using quantitative genetic principles, we outline how the selection imposed by individual mechanisms can be measured and combined to estimate the total strength and form of sexual selection. We discuss the evolutionary consequences of combining the mechanisms of sexual selection and interpreting total sexual selection. We suggest how this approach may result in

Male Educational Leadership in Greek Primary Schools: A Theoretical Framework Based on Experiences of Male School Leaders

ERIC Educational Resources Information Center

Brinia, Vassiliki

2011-01-01

Purpose: The purpose of this paper can be summarized in the following research questions: How do male school leaders perceive the role of an educational leader and educational leadership in general? What are some of the male school leaders' leadership styles and features? What distinctive factors influence and hinder the leadership process for men…

One-male units and clans in a colony of hamadryas baboons (Papio hamadryas hamadryas): effect of male number and clan cohesion on feeding success.

PubMed

Colmenares, Fernando; Esteban, Marta M; Zaragoza, Félix

2006-01-01

In the multilevel societies of hamadryas baboons, adult males can be attached to single one-male units (OMUs) or to clans containing several such OMUs. This paper examines the effect of male number and rivalry between males within a clan on their ability to compete for access to a clumped food resource. The data come from a study of a multilevel colony of hamadryas baboons (Papio hamadryas hamadryas) housed at the Madrid Zoo. The colony consisted of 12 harem-holding males and 40 sexually mature females, and was organized into five single OMUs and two clans (containing three and four OMUs, respectively). The top-ranking male of one of the clans was removed and later reintroduced, so the study involved an analysis of the composition of clans and OMUs and of the males' use of the feeding area across three study periods: preseparation, separation, and reintroduction. The findings reported indicate that both males and females derived clear advantages in the context of contest competition for access to clumped food if they were members of clans, because the males and females from large clans had a feeding advantage over those from smaller clans and single OMUs. Furthermore, rivalry among males within the clan reduced their ability to compete for food against males outside their clan. This paper provides empirical evidence for one of the potential advantages that hamadryas males may enjoy if they are attached to clans, and also provides empirical support for the general hypothesis that a large number of males in a group may provide fitness-related benefits to the group members, provided they are able to cooperate with each other. 2006 Wiley-Liss, Inc.

French Interim MALE UAV Program

DTIC Science & Technology

2003-09-02

MINISTÈRE DE LA DÉFENSE June, 13th 2002 Lcl Monsterleet FAF Staff J. Caron EADS S&DE-ISR FRENCH INTERIM MALE UAV PROGRAM 4 INDUSTRIAL STATUS Report...2003 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE French Interim Male UAV Program 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) EADS

Twentieth century surge of excess adult male mortality

PubMed Central

Beltrán-Sánchez, Hiram; Finch, Caleb E.; Crimmins, Eileen M.

2015-01-01

Using historical data from 1,763 birth cohorts from 1800 to 1935 in 13 developed countries, we show that what is now seen as normal—a large excess of female life expectancy in adulthood—is a demographic phenomenon that emerged among people born in the late 1800s. We show that excess adult male mortality is clearly rooted in specific age groups, 50–70, and that the sex asymmetry emerged in cohorts born after 1880 when male:female mortality ratios increased by as much as 50% from a baseline of about 1.1. Heart disease is the main condition associated with increased excess male mortality for those born after 1900. We further show that smoking-attributable deaths account for about 30% of excess male mortality at ages 50–70 for cohorts born in 1900–1935. However, after accounting for smoking, substantial excess male mortality at ages 50–70 remained, particularly from cardiovascular disease. The greater male vulnerability to cardiovascular conditions emerged with the reduction in infectious mortality and changes in health-related behaviors. PMID:26150507

Gap junctional communication in the male reproductive system.

PubMed

Pointis, Georges; Fiorini, Céline; Defamie, Norah; Segretain, Dominique

2005-12-20

Male fertility is a highly controlled process that allows proliferation, meiosis and differentiation of male germ cells in the testis, final maturation in the epididymis and also requires functional male accessory glands: seminal vesicles, prostate and corpus cavernosum. In addition to classical endocrine and paracrine controls, mainly by gonadotropins LH and FSH and steroids, there is now strong evidence that all these processes are dependent upon the presence of homocellular or heterocellular junctions, including gap junctions and their specific connexins (Cxs), between the different cell types that structure the male reproductive tract. The present review is focused on the identification of Cxs, their distribution in the testis and in different structures of the male genital tract (epididymis, seminal vesicle, prostate, corpus cavernosum), their crucial role in the control of spermatogenesis and their implication in the function of the male accessory glands, including functional smooth muscle tone. Their potential dysfunctions in some testis (spermatogenic arrest, seminoma) and prostate (benign hyperplasia, adenocarcinoma) diseases and in the physiopathology of the human erectile function are also discussed.

Male fighting and "territoriality" within colonies of the ant Cardiocondyla venustula.

PubMed

Frohschammer, Sabine; Heinze, Jürgen

2009-01-01

The ant genus Cardiocondyla is characterized by a bizarre male polymorphism with wingless fighter males and winged disperser males. Winged males have been lost convergently in several clades, and in at least one of them, wingless males have evolved mutual tolerance. To better understand the evolutionary pathways of reproductive tactics, we investigated Cardiocondyla venustula, a species, which in a phylogenetic analysis clusters with species with fighting and species with mutually tolerant, wingless males. Wingless males of C. venustula use their strong mandibles to kill freshly eclosed rival males and also engage in short fights with other adult males, but in addition show a novel behavior hitherto not reported from social insect males: they spread out in the natal nest and defend "territories" against other males. Ant males therefore show a much larger variety of reproductive tactics than previously assumed.

Male fighting and ``territoriality'' within colonies of the ant Cardiocondyla venustula

NASA Astrophysics Data System (ADS)

Frohschammer, Sabine; Heinze, Jürgen

2009-01-01

The ant genus Cardiocondyla is characterized by a bizarre male polymorphism with wingless fighter males and winged disperser males. Winged males have been lost convergently in several clades, and in at least one of them, wingless males have evolved mutual tolerance. To better understand the evolutionary pathways of reproductive tactics, we investigated Cardiocondyla venustula, a species, which in a phylogenetic analysis clusters with species with fighting and species with mutually tolerant, wingless males. Wingless males of C. venustula use their strong mandibles to kill freshly eclosed rival males and also engage in short fights with other adult males, but in addition show a novel behavior hitherto not reported from social insect males: they spread out in the natal nest and defend “territories” against other males. Ant males therefore show a much larger variety of reproductive tactics than previously assumed.

Male-to-female aggression in cage-housed common pheasants (Phasianus colchicus) during the breeding season was not related to male plasma testosterone level.

PubMed

Zapletal, D; Macháček, M; Suchý, P; Straková, E; Vitula, F

2018-06-01

1. The aim of this study was to investigate if male-to-female aggression of common pheasants in the course of the breeding season was related to the concentration of plasma testosterone and/or other biochemical plasma indicators in male pheasants housed in breeding cages. The influence of season on the concentration of testosterone and biochemical indicators was also investigated. 2. Males were divided into non-aggressive and aggressive groups during the breeding season based on ethological evaluation. At the beginning, in the middle and at the end of the breeding season, a blood sample was taken from all males on the same day and the concentration of selected biochemical indicators and the total circulating testosterone in the plasma were determined. 3. Male-to-female aggression during the breeding season of pheasants was not influenced by the total plasma testosterone of males. 4. The concentration of total plasma testosterone in males decreased gradually during the breeding season. 5. Male-to-female aggression of pheasants did not have a significant effect on any of the assessed biochemical indicators. 6. The influence of the breeding season affected the activities of alanine aminotransferase and aspartate aminotransferase as well as the concentrations of glucose, magnesium, potassium and chloride in the blood plasma of cage-housed male pheasants.

Pheromonal regulation of male mouse ultrasonic courtship (Mus musculus).

PubMed

Nyby, J; Wysocki, C J; Whitney, G; Dizinno, G

1977-05-01

Biochemicals from several sites on the body of female house mice (Mus musculus) were found to elicit 70-kHz ultrasonic calls from male mice. Experiment 1 demonstrated that an anaesthetized female wrapped in an odour-impermeable plastic bag elicited ultrasounds from males when either the front or rear of their body was left exposed. In experiment 2 cotton swabs rubbed on the face and cheeks of females but not from males elicited ultrasonic calls from males. The results of experiment 3 suggested that female vaginal odours also elicit calls. Experiments 4 and 5 demonstrated that males will also emit ultrasounds in response to female but not male urine. The source and chemical nature of this 'ultrasound-releasing pheromone' remain to be discovered.

In Hindsight and Now Again: Black Male Teachers' Recollections on the Suffering of Black Male Youth in US Public Schools

ERIC Educational Resources Information Center

Pabon, Amber Jean-Marie

2017-01-01

This article draws from data in a larger qualitative study on the lives of black male teachers in US public urban schools. I examine their schooling experiences as black male youth. By coupling theories of social suffering with life history methodology, this research analyzes how three black male teachers experienced frustration, marginalization,…

Characterization of Reproductive Dormancy in Male Drosophila melanogaster

PubMed Central

Kubrak, Olga I.; Kučerová, Lucie; Theopold, Ulrich; Nylin, Sören; Nässel, Dick R.

2016-01-01

Insects are known to respond to seasonal and adverse environmental changes by entering dormancy, also known as diapause. In some insect species, including Drosophila melanogaster, dormancy occurs in the adult organism and postpones reproduction. This adult dormancy has been studied in female flies where it is characterized by arrested development of ovaries, altered nutrient stores, lowered metabolism, increased stress and immune resistance and drastically extended lifespan. Male dormancy, however, has not been investigated in D. melanogaster, and its physiology is poorly known in most insects. Here we show that unmated 3–6 h old male flies placed at low temperature (11°C) and short photoperiod (10 Light:14 Dark) enter a state of dormancy with arrested spermatogenesis and development of testes and male accessory glands. Over 3 weeks of diapause we see a dynamic increase in stored carbohydrates and an initial increase and then a decrease in lipids. We also note an up-regulated expression of genes involved in metabolism, stress responses and innate immunity. Interestingly, we found that male flies that entered reproductive dormancy do not attempt to mate females kept under non-diapause conditions (25°C, 12L:12D), and conversely non-diapausing males do not mate females in dormancy. In summary, our study shows that male D. melanogaster can enter reproductive dormancy. However, our data suggest that dormant male flies deplete stored nutrients faster than females, studied earlier, and that males take longer to recover reproductive capacity after reintroduction to non-diapause conditions. PMID:27932997

Does egg colouration reflect male condition in birds?

NASA Astrophysics Data System (ADS)

Martínez-Padilla, Jesús; Dixon, Heather; Vergara, Pablo; Pérez-Rodríguez, Lorenzo; Fargallo, Juan A.

2010-05-01

How colouration provides information about individuals in birds has been a central issue in recent decades. Although much information has been derived, little is known about the adaptive significance of egg colouration in birds. A recent idea suggests that biliverdin- and porphyrin-pigmented eggs may act as a post-mating sexual signal for males to assess female quality. In birds, it is common for males to influence prelaying female condition by courtship feeding. Using Eurasian kestrels, a species that lays protoporphyrin-pigmented eggs, we descriptively assessed the influence of male feeding on egg pigmentation by considering female phenotype, condition, breeding parameters and male body condition. We found that older females and females with greyer tails (an index of individual quality) produce highly pigmented eggs. However, male body condition was the only variable that explained egg colouration when considered together with the female-related variables. Therefore, females that mated with males in better condition laid highly pigmented eggs. With the same species, we also explored the cost of producing protoporphyrin-pigmented eggs using a food-supply experiment before the laying period. Food supplementation did not increase egg pigmentation, but hatching success and egg mass were positively related to egg colouration only in food supplied pairs. We suggest that egg colouration might be costly to produce and probably suggests egg quality. However, this cost cannot be explained by female quality, but by male condition instead. In general, our results do not support the theory that egg colouration is a post-mating sexual signal in species where males determine female condition at the time of laying.

Divergent sexual selection via male competition: ecology is key.

PubMed

Lackey, A C R; Boughman, J W

2013-08-01

Sexual selection and ecological differences are important drivers of speciation. Much research has focused on female choice, yet the role of male competition in ecological speciation has been understudied. Here, we test how mating habitats impact sexual selection and speciation through male competition. Using limnetic and benthic species of threespine stickleback fish, we find that different mating habitats select differently on male traits through male competition. In mixed habitat with both vegetated and open areas, selection favours two trait combinations of male body size and nuptial colour: large with little colour and small with lots of colour. This matches what we see in reproductively isolated stickleback species, suggesting male competition could promote trait divergence and reproductive isolation. In contrast, when only open habitat exists, selection favours one trait combination, large with lots of colour, which would hinder trait divergence and reproductive isolation. Other behavioural mechanisms in male competition that might promote divergence, such as avoiding aggression with heterospecifics, are insufficient to maintain separate species. This work highlights the importance of mating habitats in male competition for both sexual selection and speciation. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

The Voices of Young Black Males

ERIC Educational Resources Information Center

Sparrow, Tracey; Sparrow, Abby

2012-01-01

What do young black males say about what stands in the way of their academic success? Rather than rely on scholarly researchers to answer this question, the authors talked with a number of black males between ages 13 and 22 in Washington D.C., and Milwaukee, Wis., to learn what they had to say. These young men rarely talked about schools or…

Suffering in Silence: The Male Incest Victim.

ERIC Educational Resources Information Center

Nasjleti, Maria

1980-01-01

The reasons why boys who are victims of incest remain silent are explored in terms of the special meaning of victimization to males. Males' inability to express helplessness and vulnerability is identified as a major contributing factor. (CM)

Sexual selection of male parental care in giant water bugs

PubMed Central

Ohba, Shin-ya; Okuda, Noboru; Kudo, Shin-ichi

2016-01-01

Paternal care can be maintained under sexual selection, if it helps in attracting more mates. We tested the hypothesis in two giant water bug species, Appasus major and Appasus japonicus, that male parental care is sexually selected through female preference for caring males. Females were given an opportunity to choose between two males. In the first test of female mate choice, one male carried eggs on its back, while the other did not. The egg status was switched between these two males in the second test. The experiment revealed that females of both species preferred caring males (i.e. egg-bearing) to non-caring males. Nonetheless, the female mate preference for egg-bearing males was stronger in A. major than in A. japonicus. Our results suggest that sexual selection plays an important role in maintaining elaborate paternal care in giant water bugs, but the importance of egg-bearing by males in female mate choice varies among species. PMID:27293778

Different responses to soy and estradiol in the reproductive system of prepubertal male rats and neonatal male pigs

USDA-ARS?s Scientific Manuscript database

Concerns have been raised regarding the safety of soy infant formula based on phytochemical components such as genistein, structurally similar to estradiol (E2). To examine potential estrogenic actions on male development, we fed weanling male rats casein-based or soy protein isolate (SPI)-based die...

Facing Aggression: Cues Differ for Female versus Male Faces

PubMed Central

Geniole, Shawn N.; Keyes, Amanda E.; Mondloch, Catherine J.; Carré, Justin M.; McCormick, Cheryl M.

2012-01-01

The facial width-to-height ratio (face ratio), is a sexually dimorphic metric associated with actual aggression in men and with observers' judgements of aggression in male faces. Here, we sought to determine if observers' judgements of aggression were associated with the face ratio in female faces. In three studies, participants rated photographs of female and male faces on aggression, femininity, masculinity, attractiveness, and nurturing. In Studies 1 and 2, for female and male faces, judgements of aggression were associated with the face ratio even when other cues in the face related to masculinity were controlled statistically. Nevertheless, correlations between the face ratio and judgements of aggression were smaller for female than for male faces (F1,36 = 7.43, p = 0.01). In Study 1, there was no significant relationship between judgements of femininity and of aggression in female faces. In Study 2, the association between judgements of masculinity and aggression was weaker in female faces than for male faces in Study 1. The weaker association in female faces may be because aggression and masculinity are stereotypically male traits. Thus, in Study 3, observers rated faces on nurturing (a stereotypically female trait) and on femininity. Judgements of nurturing were associated with femininity (positively) and masculinity (negatively) ratings in both female and male faces. In summary, the perception of aggression differs in female versus male faces. The sex difference was not simply because aggression is a gendered construct; the relationships between masculinity/femininity and nurturing were similar for male and female faces even though nurturing is also a gendered construct. Masculinity and femininity ratings are not associated with aggression ratings nor with the face ratio for female faces. In contrast, all four variables are highly inter-correlated in male faces, likely because these cues in male faces serve as “honest signals”. PMID:22276184

Facing aggression: cues differ for female versus male faces.

PubMed

Geniole, Shawn N; Keyes, Amanda E; Mondloch, Catherine J; Carré, Justin M; McCormick, Cheryl M

2012-01-01

The facial width-to-height ratio (face ratio), is a sexually dimorphic metric associated with actual aggression in men and with observers' judgements of aggression in male faces. Here, we sought to determine if observers' judgements of aggression were associated with the face ratio in female faces. In three studies, participants rated photographs of female and male faces on aggression, femininity, masculinity, attractiveness, and nurturing. In Studies 1 and 2, for female and male faces, judgements of aggression were associated with the face ratio even when other cues in the face related to masculinity were controlled statistically. Nevertheless, correlations between the face ratio and judgements of aggression were smaller for female than for male faces (F(1,36) = 7.43, p = 0.01). In Study 1, there was no significant relationship between judgements of femininity and of aggression in female faces. In Study 2, the association between judgements of masculinity and aggression was weaker in female faces than for male faces in Study 1. The weaker association in female faces may be because aggression and masculinity are stereotypically male traits. Thus, in Study 3, observers rated faces on nurturing (a stereotypically female trait) and on femininity. Judgements of nurturing were associated with femininity (positively) and masculinity (negatively) ratings in both female and male faces. In summary, the perception of aggression differs in female versus male faces. The sex difference was not simply because aggression is a gendered construct; the relationships between masculinity/femininity and nurturing were similar for male and female faces even though nurturing is also a gendered construct. Masculinity and femininity ratings are not associated with aggression ratings nor with the face ratio for female faces. In contrast, all four variables are highly inter-correlated in male faces, likely because these cues in male faces serve as "honest signals".

Differences in personality traits between male-to-female and female-to-male gender identity disorder subjects.

PubMed

Miyajima, Eiichi; Taira, Naoki; Koda, Munenaga; Kondo, Tsuyoshi

2014-12-15

The present study aimed to investigate differences in personality traits among male-to-female (MtF), female-to-male (FtM) gender identity disorder (GID) subjects and non-transsexual male (M) and female (F) controls. Subjects were 72 MtF and 187 FtM GID subjects without psychiatric comorbidities together with 184 male and 159 female non-transsexual controls. Personality traits were assessed using a short version of the Temperament and Character Inventory (TCI-125). Group comparisons were made by two-way ANOVA. Statistical significances were observed as follows: 1) lower novelty seeking in FtM than in M or MtF, 2) higher reward dependence in FtM than in M, 3) higher cooperativeness in FtM than in M or MtF, 4) the highest self-transcendence in MtF among all the groups. The highest self-transcendence in MtF subjects may reflect their vulnerable identity and constrained adaptation to society as the minority. Nevertheless, higher reward dependence and cooperativeness in FtM subjects can be related to more determined motivation for the treatments of GID and might promise better social functioning and adjustment than MtF subjects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effect of Chinese Herbal Medicine on Male Infertility.

PubMed

Jiang, Dan; Coscione, Alberto; Li, Lily; Zeng, Bai-Yun

2017-01-01

Male infertility normally refers a male's inability to cause pregnancy in a fertile female partner after 1 year of unprotected intercourse. Male infertility in recent years has been attracting increasing interest from public due to the evidence in decline in semen quality. There are many factors contributing to the male infertility including abnormal spermatogenesis; reproductive tract anomalies or obstruction; inadequate sexual and ejaculatory functions; and impaired sperm motility, imbalance in hormone levels, and immune system dysfunction. Although conventional treatments such as medication, surgical operation, and advanced techniques have helped many male with infertility cause pregnancy in their female partners, effectiveness is not satisfactory and associated with adverse effects. Chinese herbal medicine (CHM) has been used to improve male infertility in China for a very long time and has now been increasingly popular in Western countries for treating infertility. In this chapter we summarized recent development in basic research and clinical studies of CHM in treating male infertility. It has showed that CHM improved sperm motility and quality, increased sperm count and rebalanced inadequate hormone levels, and adjusted immune functions leading to the increased number of fertility. Further, CHM in combination with conventional therapies improved efficacy of conventional treatments. More studies are needed to indentify the new drugs from CHM and ensure safety, efficacy, and consistency of CHM. © 2017 Elsevier Inc. All rights reserved.

Male chest enhancement: pectoral implants.

PubMed

Benito-Ruiz, J; Raigosa, J M; Manzano-Surroca, M; Salvador, L

2008-01-01

The authors present their experience with the pectoral muscle implant for male chest enhancement in 21 patients. The markings and technique are thoroughly described. The implants used were manufactured and custom made. The candidates for implants comprised three groups: group 1 (18 patients seeking chest enhancement), group 2 (1 patient with muscular atrophy), and group 3 (2 patients with muscular injuries). Because of the satisfying results obtained, including significant enhancement of the chest contour and no major complications, this technique is used for an increasing number of male cosmetic surgeries.

[Male sexuality in the elderly].

PubMed

Rinnab, L; Schrader, A J; Schrader, M; Zengerling, F

2012-10-01

Male sexuality in the elderly is an important issue with a growing relevance. In contrast to the assumption of an asexual state when becoming older, recent representative surveys show that the majority of men maintain sexual desires and fantasies into old age. Sexual activity primarily depends on the availability of a partner and on maintaining intimacy and sexuality in the face of changes in the sexual response cycle and increasing comorbidity. This review aims to clarify the normal aging process, the sexual behavior of aging males and the prevalence of sexual dysfunction.

Management practices for male calves on Canadian dairy farms.

PubMed

Renaud, D L; Duffield, T F; LeBlanc, S J; Haley, D B; Kelton, D F

2017-08-01

Morbidity, mortality, and antimicrobial use and resistance are major concerns in the rearing of male dairy calves, so information to support disease prevention is important. The objective of this cross-sectional study was to describe management practices associated with the care of male calves during their first days of life on Canadian dairy farms. A survey was completed by dairy producers across Canada between March 1 and April 30, 2015. The survey included 192 questions covering producer background, farm characteristics, biosecurity practices, disease prevalence, calf health, animal welfare, lameness, milking hygiene, reproduction, and Internet and social media use. A total of 1,025 surveys were completed online, by telephone, or by mail, representing 9% of all dairy farms in Canada. Five percent of respondents (n = 49) answered that they had euthanized at least 1 male calf at birth in the previous year, and blunt force trauma was commonly used in these cases. The majority of respondents always fed colostrum to male calves; however, 9% (n = 80) did not always feed colostrum. Almost 40% (n = 418) of respondents reported always dipping the navels of male calves, 12% (n = 123) vaccinated male calves, and 17% (n = 180) did not provide the same quantity of feed to male calves as heifer calves. The care of male calves differed greatly depending on the geographical region of the respondents. However, some regional effects may be confounded by economic conditions and the logistics of marketing male dairy calves in different parts of the country. Herd size was another important variable in many aspects of the management of male calves on dairy farms. Larger herd sizes were more likely to use an appropriate method of euthanasia at birth but were less likely to always feed colostrum to their male calves or feed them the same as female calves. Familiarity with the Code of Practice for the Care and Handling of Dairy Cattle (National Farm Animal Care Council) by respondents

Idiopathic Subareolar Breast Abscess in a Male Patient

PubMed Central

Ranga, Upasana; Veeraiyan, Saveetha

2015-01-01

We present a case of left breast abscess in a young male patient who presented with acute onset swelling left breast. Imaging studies helped in accurate diagnosis and the case was managed by subareolar incision and drainage. Subareolar breast abscess is an uncommon entity in male and should be kept as a differential diagnosis for male breast swellings. PMID:25738061

A new public health context to understand male sex work.

PubMed

Minichiello, Victor; Scott, John; Callander, Denton

2015-03-24

Researching male sex work offers insight into the sexual lives of men and women while developing a more realistic appreciation for the changing issues associated with male sex work. This type of research is important because it not only reflects a growing and diversifying consumer demand for male sex work, but also because it enables the construction of knowledge that is up-to-date with changing ideas around sex and sexualities. This paper discusses a range of issues emerging in the male sex industry. Notably, globalisation and technology have contributed to the normalisation of male sex work and reshaped the landscape in which the male sex industry operates. As part of this discussion, we review STI and HIV rates among male sex workers at a global level, which are widely disparate and geographically contextual, with rates of HIV among male sex workers ranging from 0% in some areas to 50% in others. The Internet has reshaped the way that male sex workers and clients connect and has been identified as a useful space for safer sex messages and research that seeks out hidden or commonly excluded populations. We argue for a public health context that recognises the emerging and changing nature of male sex work, which means programs and policies that are appropriate for this population group. Online communities relating to male sex work are important avenues for safer sexual messages and unique opportunities to reach often excluded sub-populations of both clients and male sex workers. The changing structure and organisation of male sex work alongside rapidly changing cultural, academic and medical discourses provide new insight but also new challenges to how we conceive the sexualities of men and male sex workers. Public health initiatives must reflect upon and incorporate this knowledge.

XX/XY Sex Chromosomes in the South American Dwarf Gecko (Gonatodes humeralis).

PubMed

Gamble, Tony; McKenna, Erin; Meyer, Wyatt; Nielsen, Stuart V; Pinto, Brendan J; Scantlebury, Daniel P; Higham, Timothy E

2018-05-11

Sex-specific genetic markers identified using restriction site-associated DNA sequencing, or RADseq, permits the recognition of a species' sex chromosome system in cases where standard cytogenetic methods fail. Thus, species with male-specific RAD markers have an XX/XY sex chromosome system (male heterogamety) while species with female-specific RAD markers have a ZZ/ZW sex chromosome (female heterogamety). Here, we use RADseq data from 5 male and 5 female South American dwarf geckos (Gonatodes humeralis) to identify an XX/XY sex chromosome system. This is the first confidently known sex chromosome system in a Gonatodes species. We used a low-coverage de novo G. humeralis genome assembly to design PCR primers to validate the male-specificity of a subset of the sex-specific RADseq markers and describe how even modest genome assemblies can facilitate the design of sex-specific PCR primers in species with diverse sex chromosome systems.

Addressing the Crisis of African American Males in Community Colleges: The Impact of Leadership & Black Male Initiatives

ERIC Educational Resources Information Center

Harewood, Wayne R.

2013-01-01

The word "crisis" has been used to describe the impact of the current educational system (K-12) upon the lives of African American males. Black males are the group most likely to be negatively stereotyped, the most likely to drop out of K-12, the most likely to be harshly punished, and the most likely to be labeled as a trouble maker.…

Male dominance rank and reproductive success in chimpanzees, Pan troglodytes schweinfurthii.

PubMed

Wroblewski, Emily E; Murray, Carson M; Keele, Brandon F; Schumacher-Stankey, Joann C; Hahn, Beatrice H; Pusey, Anne E

2009-01-01

Competition for fertile females determines male reproductive success in many species. The priority of access model predicts that male dominance rank determines access to females, but this model has been difficult to test in wild populations, particularly in promiscuous mating systems. Tests of the model have produced variable results, probably because of the differing socioecological circumstances of individual species and populations. We tested the predictions of the priority of access model in the chimpanzees of Gombe National Park, Tanzania. Chimpanzees are an interesting species in which to test the model because of their fission-fusion grouping patterns, promiscuous mating system and alternative male mating strategies. We determined paternity for 34 offspring over a 22-year period and found that the priority of access model was generally predictive of male reproductive success. However, we found that younger males had higher success per male than older males, and low-ranking males sired more offspring than predicted. Low-ranking males sired offspring with younger, less desirable females and by engaging in consortships more often than high-ranking fathers. Although alpha males never sired offspring with related females, inbreeding avoidance of high-ranking male relatives did not completely explain the success of low-ranking males. While our work confirms that male rank typically predicts male chimpanzee reproductive success, other factors are also important; mate choice and alternative male strategies can give low-ranking males access to females more often than would be predicted by the model. Furthermore, the success of younger males suggests that they are more successful in sperm competition.

The Influence of Sexual Orientation on the Perceived Fit of Male Applicants for Both Male- and Female-Typed Jobs.

PubMed

Clarke, Heather M; Arnold, Kara A

2018-01-01

Research demonstrates the bias faced by individuals engaged in occupations that are perceived as inconsistent with their gender. The lack of fit model and role congruity theory explain how gender stereotypes give rise to the perception that an individual lacks the attributes necessary to be successful in a gender-incongruent job. Men employed in jobs traditionally held by women are perceived as wimpy and undeserving of respect. The majority of studies in this area have, however, failed to account for the sexual orientation of the individual being rated. Therefore, we carried out an experiment where 128 adults with experience in recruitment and selection, recruited through Qualtrics, rated heterosexual and gay male applicants applying for a gender-typed job. The heterosexual male was rated less effectual, less respect-worthy, and less hirable in the female-typed job condition than in the male-typed job condition. The gay male applicant, however, was rated similarly on all criteria across job gender-types, suggesting the gay male applicant was viewed as androgynous rather than high in femininity and low in masculinity as inferred by implicit inversion theory. The implications of these findings are discussed.

The Influence of Sexual Orientation on the Perceived Fit of Male Applicants for Both Male- and Female-Typed Jobs

PubMed Central

Clarke, Heather M.; Arnold, Kara A.

2018-01-01

Research demonstrates the bias faced by individuals engaged in occupations that are perceived as inconsistent with their gender. The lack of fit model and role congruity theory explain how gender stereotypes give rise to the perception that an individual lacks the attributes necessary to be successful in a gender-incongruent job. Men employed in jobs traditionally held by women are perceived as wimpy and undeserving of respect. The majority of studies in this area have, however, failed to account for the sexual orientation of the individual being rated. Therefore, we carried out an experiment where 128 adults with experience in recruitment and selection, recruited through Qualtrics, rated heterosexual and gay male applicants applying for a gender-typed job. The heterosexual male was rated less effectual, less respect-worthy, and less hirable in the female-typed job condition than in the male-typed job condition. The gay male applicant, however, was rated similarly on all criteria across job gender-types, suggesting the gay male applicant was viewed as androgynous rather than high in femininity and low in masculinity as inferred by implicit inversion theory. The implications of these findings are discussed. PMID:29774007

Lived Experiences of Novice Male Nurses in Taiwan.

PubMed

Cheng, Mei-Li; Tseng, Ying-Hua; Hodges, Eric; Chou, Fan-Hao

2016-11-03

Nursing remains a female-dominated profession around the world. The masculinity and male identity of men who choose nursing careers is questioned by the general public in many countries. Few studies report the situation of novice male nurses at their first year. The purpose of this study was to explore the lived experience of novice male nurses when they first enter the workplace. A qualitative descriptive study was conducted using purposive and snowball sampling for recruitment. Fourteen participants, 21 to 25 years old, were recruited, all of whom had at least 5 months of work experience. On average, in-depth, face-to-face interviews lasted 1 hour, with more than one follow-up telephone interview per participant. The following six themes emerged from the transcribed verbatim data based on content analysis: choosing appropriate work departments based on personality and needs, facing the pressure and frustration of independent work, getting help, obtaining acceptance among female cliques, reflecting on the relationship between gender and profession, and concerns about dependents and financial needs. This study addresses masculinity issues and gender stereotyping. In addition, male nurses were very concerned about their career options and development and the likelihood of promotion. This research not only has implications for better understanding of novice male nurses' needs and the challenges in their social life but also makes suggestions for nursing practice to attract and keep more male nurses in the nursing profession. The results illustrate how culturally congruent nursing care can be achieved when we more concern male nurses' role pressure and address traditional gender sensitivity to promote male nurses' career development. © The Author(s) 2016.

Smoking and Male Infertility: An Evidence-Based Review

PubMed Central

Harlev, Avi; Gunes, Sezgin Ozgur; Shetty, Amit; du Plessis, Stefan Simon

2015-01-01

Many studies have reported that the contents of cigarette smoke negatively affect sperm parameters, seminal plasma, and various other fertility factors. Nevertheless, the actual effect of smoking on male fertility is not clear. The effect of smoking on semen parameters is based on the well-established biological finding that smoking increases the presence of reactive oxygen species, thereby resulting in oxidative stress (OS). OS has devastating effects on sperm parameters, such as viability and morphology, and impairs sperm function, hence reducing male fertility. However, not all studies have come to the same conclusions. This review sheds light upon the arguable association between smoking and male fertility and also assesses the impact of non-smoking routes of tobacco consumption on male infertility. It also highlights the evidence that links smoking with male infertility, including newly emerging genetic and epigenetic data, and discusses the clinical implications thereof. PMID:26770934

Decline in male circumcision in South Korea.

PubMed

Kim, DaiSik; Koo, Sung-Ae; Pang, Myung-Geol

2012-12-11

To investigate the changing circumcision rate in South Korea in the last decade and to propose underlying causes for this change, in the context of the present fluctuating world-wide trends in circumcision. From 2009 to 2011, 3,296 South Korean males (or their parents) aged 0-64 years were asked about their circumcision status, their age at circumcision, and their information level regarding circumcision. We employed non-probability sampling considering the sensitive questions on the study theme. Currently the age-standardized circumcision rate for South Korean males aged 14-29 is found to be 75.8%. In an earlier study performed in 2002, the rate for the same age group was 86.3%. Of particular interest, males aged 14-16 show a circumcision rate of 56.4%, while the same age group 10 years ago displayed a much higher percentage, at 88.4%. In addition, the extraordinarily high circumcision rate of 95.2% found 10 years ago for the 17-19 age group is now reduced to 74.4%. Interestingly, of the circumcised males, the percentage circumcised in the last decade was only 25.2%; i.e., the majority of the currently circumcised males had undergone the operation prior to 2002, indicating that the actual change in the last decade is far greater. Consistent with this conjecture, the 2002 survey showed that the majority of circumcised males (75.7%) had undergone the operation in the decade prior to that point. Focusing on the flagship age group of 14-16, this drop suggests that, considering the population structure of Korean males, approximately one million fewer circumcision operations have been performed in the last decade relative to the case of non-decline. This decline is strongly correlated with the information available through internet, newspapers, lectures, books, and television: within the circumcised population, both the patients and their parents had less prior knowledge regarding circumcision, other than information obtained from person to person by oral communication

Male brush-turkeys attempt sexual coercion in unusual circumstances.

PubMed

Wells, David A; Jones, Darryl N; Bulger, David; Brown, Culum

2014-07-01

Sexual coercion by males is generally understood to have three forms: forced copulation, harassment and intimidation. We studied Australian brush-turkeys, Alectura lathami, to determine whether some male behaviours towards females at incubation mounds could be classified as aggressive, whether males were attempting sexual coercion and, if so, whether the coercion was successful. We found that some male behaviours towards females were significantly more likely to be followed by the cessation of female mound activity, and hence could be classified as aggressive, while others were significantly more likely to be followed by the commencement of female mound activity, and hence could be classified as enticing. Copulation was preceded by higher rates of male enticement and by higher rates of certain types of male aggression. It therefore seemed that males were attempting sexual coercion. There was little evidence, however, that this combination of coercion and enticement was successful in obtaining copulations. While forced copulation did occur, it was infrequent, and no evidence could be found for intimidation. We conclude that harassment is the primary form of sexual coercion by male brush-turkeys. Although sexual coercion is understood to be a sub-optimal tactic, brush-turkey sexual coercion was employed as a primary tactic by dominant males who owned incubation mounds. One possible explanation for this apparent paradox is that aggression is the default solution for social conflicts in this species, and hence can be interpreted as a behavioural syndrome. Copyright © 2014 Elsevier B.V. All rights reserved.

Individual recognition based on communication behaviour of male fowl.

PubMed

Smith, Carolynn L; Taubert, Jessica; Weldon, Kimberly; Evans, Christopher S

2016-04-01

Correctly directing social behaviour towards a specific individual requires an ability to discriminate between conspecifics. The mechanisms of individual recognition include phenotype matching and familiarity-based recognition. Communication-based recognition is a subset of familiarity-based recognition wherein the classification is based on behavioural or distinctive signalling properties. Male fowl (Gallus gallus) produce a visual display (tidbitting) upon finding food in the presence of a female. Females typically approach displaying males. However, males may tidbit without food. We used the distinctiveness of the visual display and the unreliability of some males to test for communication-based recognition in female fowl. We manipulated the prior experience of the hens with the males to create two classes of males: S(+) wherein the tidbitting signal was paired with a food reward to the female, and S (-) wherein the tidbitting signal occurred without food reward. We then conducted a sequential discrimination test with hens using a live video feed of a familiar male. The results of the discrimination tests revealed that hens discriminated between categories of males based on their signalling behaviour. These results suggest that fowl possess a communication-based recognition system. This is the first demonstration of live-to-video transfer of recognition in any species of bird. Copyright © 2016 Elsevier B.V. All rights reserved.

Mating competitiveness of sterile male Anopheles coluzzii in large cages.

PubMed

Maïga, Hamidou; Damiens, David; Niang, Abdoulaye; Sawadogo, Simon P; Fatherhaman, Omnia; Lees, Rosemary S; Roux, Olivier; Dabiré, Roch K; Ouédraogo, Georges A; Tripet, Fréderic; Diabaté, Abdoulaye; Gilles, Jeremie R L

2014-11-26

Understanding the factors that account for male mating competitiveness is critical to the development of the sterile insect technique (SIT). Here, the effects of partial sterilization with 90 Gy of radiation on sexual competitiveness of Anopheles coluzzii allowed to mate in different ratios of sterile to untreated males have been assessed. Moreover, competitiveness was compared between males allowed one versus two days of contact with females. Sterile and untreated males four to six days of age were released in large cages (~1.75 sq m) with females of similar age at the following ratios of sterile males: untreated males: untreated virgin females: 100:100:100, 300:100:100, 500:100:100 (three replicates of each) and left for two days. Competitiveness was determined by assessing the egg hatch rate and the insemination rate, determined by dissecting recaptured females. An additional experiment was conducted with a ratio of 500:100:100 and a mating period of either one or two days. Two controls of 0:100:100 (untreated control) and 100:0:100 (sterile control) were used in each experiment. When males and females consort for two days with different ratios, a significant difference in insemination rate was observed between ratio treatments. The competitiveness index (C) of sterile males compared to controls was 0.53. The number of days of exposure to mates significantly increased the insemination rate, as did the increased number of males present in the untreated: sterile male ratio treatments, but the number of days of exposure did not have any effect on the hatch rate. The comparability of the hatch rates between experiments suggest that An. coluzzii mating competitiveness experiments in large cages could be run for one instead of two days, shortening the required length of the experiment. Sterilized males were half as competitive as untreated males, but an effective release ratio of at least five sterile for one untreated male has the potential to impact the fertility of

Highly Competitive Reindeer Males Control Female Behavior during the Rut

PubMed Central

Body, Guillaume; Weladji, Robert B.; Holand, Øystein; Nieminen, Mauri

2014-01-01

During the rut, female ungulates move among harems or territories, either to sample mates or to avoid harassment. Females may be herded by a male, may stay with a preferred male, or aggregate near a dominant male to avoid harassment from other males. In fission-fusion group dynamics, female movement is best described by the group’s fission probability, instead of inter-harem movement. In this study, we tested whether male herding ability, female mate choice or harassment avoidance influence fission probability. We recorded group dynamics in a herd of reindeer Rangifer tarandus equipped with GPS collars with activity sensors. We found no evidence that the harassment level in the group affected fission probability, or that females sought high rank (i.e. highly competitive and hence successful) males. However, the behavior of high ranked males decreased fission probability. Male herding activity was synchronous with the decrease of fission probability observed during the rut. We concluded that male herding behavior stabilized groups, thereby increasing average group size and consequently the opportunity for sexual selection. PMID:24759701

[Impact of cell phone radiation on male reproduction].

PubMed

Kang, Ning; Shang, Xue-Jun; Huang, Yu-Feng

2010-11-01

With the popularized use cell phones, more and more concern has been aroused over the effects of their radiation on human health, particularly on male reproduction. Cell phone radiation may cause structural and functional injuries of the testis, alteration of semen parameters, reduction of epididymal sperm concentration and decline of male fertility. This article presents an overview on the impact of cell phone radiation on male reproduction.

Commentary: Causes and consequences of male adult sexual assault.

PubMed

Wall, Barry W

2011-01-01

Bullock and Beckson add to a growing body of literature on the negative consequences of adult sexual assault on male victims. There are similarities as well as important differences between male sexual assault victims and their female counterparts. Their analyses of societal contributions and myths about adult male sexual assault and of the difficulties that male victims experience in accessing and interacting with the medical and legal systems improve professional understanding of this complex subject.

Male-mediated developmental toxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Diana

2005-09-01

In recent years, the public has become more aware that exposure of males to certain agents can adversely affect their offspring and cause infertility and cancer. The hazards associated with exposure to ionising radiation have been recognised for nearly a century, but interest was aroused when a cluster of leukaemia cases was identified in young children living in Seascale, close to the nuclear processing plant at Sellafield in West Cumbria. There was a civil court case on behalf of two of the alleged victims of paternal irradiation at Seascale against British Nuclear Fuels. The case foundered on 'the balance ofmore » probabilities'. Nevertheless, there was support for paternal exposure from Japanese experimental X-ray studies in mice. The tumours were clearly heritable as shown by F2 transmission. Also, effects of a relatively non-toxic dose of radiation (1Gy) on cell proliferation transmitted to the embryo were manifested in the germ line of adult male mice even after two generations. In addition in humans, smoking fathers appear to give rise to tumours in the F{sub 1} generation. Using rodent models, developmental abnormalities/congenital malformations and tumours can be studied after exposure of males in an extended dominant lethal assay and congenital malformations can be determined which have similar manifestations in humans. The foetuses can also be investigated for skeletal malformations and litters can be allowed to develop to adulthood when tumours, if present, can be observed. Karyotype analysis can be performed on foetuses and adult offspring to determine if induced genetic damage can be transmitted. Using this study design, cyclophosphamide, 1,3-butadiene and urethane have been examined and each compound produced positive responses: cyclophosphamide in all endpoints examined, 1,3-butadiene in some and urethane only produced liver tumours in F{sub 1} male offspring. This suggests the endpoints are determined by independent genetic events. The results

Primary Teacher Trainee Perspectives on a Male-Only Support Group: Moving Male Trainee Teachers beyond the "Freak Show"

ERIC Educational Resources Information Center

Warwick, Jane; Warwick, Paul; Hopper, Bev

2012-01-01

This paper reports the perspectives of male trainees on mechanisms instituted to support them during their Post-Graduate Certificate of Education in Early Years and Primary Education in England. The male trainees were interviewed towards the end of their training, using semi-structured interviews that provided scope for pursuing several lines of…

Male-specific sesquiterpenes from Phyllotreta flea beetles

USDA-ARS?s Scientific Manuscript database

Flea beetles in several genera are known to possess male-specific sesquiterpenes, at least some of which serve as aggregation pheromones that attract both sexes. In continuing research on the chemical ecology of Phyllotreta flea beetles, six new male-specific sesquiterpenes were identified, one fro...

Insurance coverage for male infertility care in the United States.

PubMed

Dupree, James M

2016-01-01

Infertility is a common condition experienced by many men and women, and treatments are expensive. The World Health Organization and American Society of Reproductive Medicine define infertility as a disease, yet private companies infrequently offer insurance coverage for infertility treatments. This is despite the clear role that healthcare insurance plays in ensuring access to care and minimizing the financial burden of expensive services. In this review, we assess the current knowledge of how male infertility care is covered by insurance in the United States. We begin with an appraisal of the costs of male infertility care, then examine the state insurance laws relevant to male infertility, and close with a discussion of why insurance coverage for male infertility is important to both men and women. Importantly, we found that despite infertility being classified as a disease and males contributing to almost half of all infertility cases, coverage for male infertility is often excluded from health insurance laws. Excluding coverage for male infertility places an undue burden on their female partners. In addition, excluding care for male infertility risks missing opportunities to diagnose important health conditions and identify reversible or irreversible causes of male infertility. Policymakers should consider providing equal coverage for male and female infertility care in future health insurance laws.

Insurance coverage for male infertility care in the United States

PubMed Central

Dupree, James M

2016-01-01

Infertility is a common condition experienced by many men and women, and treatments are expensive. The World Health Organization and American Society of Reproductive Medicine define infertility as a disease, yet private companies infrequently offer insurance coverage for infertility treatments. This is despite the clear role that healthcare insurance plays in ensuring access to care and minimizing the financial burden of expensive services. In this review, we assess the current knowledge of how male infertility care is covered by insurance in the United States. We begin with an appraisal of the costs of male infertility care, then examine the state insurance laws relevant to male infertility, and close with a discussion of why insurance coverage for male infertility is important to both men and women. Importantly, we found that despite infertility being classified as a disease and males contributing to almost half of all infertility cases, coverage for male infertility is often excluded from health insurance laws. Excluding coverage for male infertility places an undue burden on their female partners. In addition, excluding care for male infertility risks missing opportunities to diagnose important health conditions and identify reversible or irreversible causes of male infertility. Policymakers should consider providing equal coverage for male and female infertility care in future health insurance laws. PMID:27030084

Genital size: a common adolescent male concern.

PubMed

Lee, Peter A; Reiter, Edward O

2002-02-01

Long before adolescence, males hear insinuations about adequacy of penis size. This concern may heighten during teen years and persist to varying degrees into adulthood. Men tend to underestimate their own penis size. This chapter provides objective information about anatomy and growth of the penis, including data about normal sizes. Published data indicate that, although full growth may be reached at different ages during adolescence, size is similar for most adult males. Hopefully, this information will provide the basis for teenaged males to develop a healthy perspective and to avoid intimidation by unfounded claims about sexual enhancement or size enlargement techniques.

Ectopic Male Breast Cancer: A Case Report

PubMed Central

Samanta, Dipti Rani; Upadhyay, Ashish; Sheet, Saikat; Senapati, Surendra Nath

2015-01-01

Carcinoma of male breast constitutes 1% of total breast malignancy. Carcinoma arising from ectopic breast tissue in male is an extremely rare entity and can be misdiagnosed. Ectopic breast tissue may be supernumerary or aberrant one. Despite morphologic difference, ectopic breast tissue presents characteristics analogous to orthoptic breast in terms of functional and pathologic degeneration. Most of the ectopic breast tissue occurs in thoracic or abdominal portion of milk line. If found in a location outside the milk line, it proves a diagnostic dilemma. We are reporting a case of 60-year-old male who presented with a fixed mass of size 10cm×8cm, in right chest wall infraclavicular area of 6 months duration. Histopathology of the mass revealed invasive duct carcinoma. He had no evidence of malignant or occult primary lesion in the bilateral mammary glands. Due to the paucity of the literature, incidence of ectopic male breast cancer and its management is not well understood. There is high probability of misdiagnosis of this disease. To the best of our knowledge this is the first described case of ectopic male breast cancer in the chest wall, not along the milk line, which is being reported here for documentation. PMID:26436033

Transcript levels of ten caste-related genes in adult diploid males of Melipona quadrifasciata (Hymenoptera, Apidae) - A comparison with haploid males, queens and workers

PubMed Central

Borges, Andreia A.; Humann, Fernanda C.; Oliveira Campos, Lucio A.; Tavares, Mara G.; Hartfelder, Klaus

2011-01-01

In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males. PMID:22215977

Transcript levels of ten caste-related genes in adult diploid males of Melipona quadrifasciata (Hymenoptera, Apidae) - A comparison with haploid males, queens and workers.

PubMed

Borges, Andreia A; Humann, Fernanda C; Oliveira Campos, Lucio A; Tavares, Mara G; Hartfelder, Klaus

2011-10-01

In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males.

Long distance transport of irradiated male Glossina palpalis gambiensis pupae and its impact on sterile male yield.

PubMed

Pagabeleguem, Soumaïla; Seck, Momar Talla; Sall, Baba; Vreysen, Marc J B; Gimonneau, Geoffrey; Fall, Assane Gueye; Bassene, Mireille; Sidibé, Issa; Rayaissé, Jean-Baptiste; Belem, Adrien M G; Bouyer, Jérémy

2015-05-01

The application of the sterile insect technique (SIT) requires mass-production of sterile males of good biological quality. The size of the project area will in most cases determine whether it is more cost effective to produce the sterile flies locally (and invest in a mass-rearing facility) or import the sterile flies from a mass-rearing facility that is located in another country. This study aimed at assessing the effect of long distance transport of sterile male Glossina palpalis gambiensis pupae on adult male fly yield. The male pupae were produced at the Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES), Bobo-Dioulasso, Burkina Faso, and shipped with a commercial courier service in insulated transport boxes at a temperature of ±10°C to Senegal (±36 h of transport). Upon arrival in the insectary in Dakar, the pupae were transferred to an emergence room and the flies monitored for 3-6 days. The results showed that the used system of isothermal boxes that contained phase change material packs (S8) managed to keep the temperature at around 10°C which prevented male fly emergence during transport. The emergence rate was significantly higher for pupae from batch 2 (chilled at 4°C for one day in the source insectary before transport) than those from batch 1 (chilled at 4°C for two days in the source insectary before transport) i.e. an average (±sd) of 76.1 ± 13.2% and 72.2 ± 14.3%, respectively with a small proportion emerging during transport (0.7 ± 1.7% and 0.9 ± 2.9%, respectively). Among the emerged flies, the percentage with deformed (not fully expanded) wings was significantly higher for flies from batch 1 (12.0 ± 6.3%) than from batch 2 (10.7 ± 7.5%). The amount of sterile males available for release as a proportion of the total pupae shipped was 65.8 ± 13.3% and 61.7 ± 14.7% for batch 1 and 2 pupae, respectively. The results also showed that the temperature inside the

Male contraception: history and development.

PubMed

Kogan, Paul; Wald, Moshe

2014-02-01

Although the twentieth century has seen great strides in the development of female contraception, not a single new agent has been introduced as an approved method for common use for male contraception. Condoms (considered uncomfortable by some) and vasectomy (a permanent invasive procedure) are the only options provided to men, leaving an undue burden on women to bear contraceptive responsibility. Significant developments have, however, been made with regard to hormonal and nonhormonal contraception, and minor, reversible, procedural contraception. This article reviews the currently available, soon to be available, and theoretically possible methods of male contraception. Copyright © 2014 Elsevier Inc. All rights reserved.

The interrelationship between genes, microprolactinoma and male homosexuality.

PubMed

Roper, Walter Geoffrey

2016-09-01

This hypothesis clearly proposes the true and previously undiscovered cause of male homosexuality or bisexuality and in most cases the predictability in infancy of the development of this sexuality in adulthood. It is based on compelling new evidence which has accumulated over many years. The fetal and neonatal periods are of the utmost importance in human development because they encompass critical periods which must be adhered to, for normal development. Biological variations may occur during these times, without implying the process of disease. This paper takes into account new paediatric hormonal and other evidence which has accumulated in the past two decades concerning the causation of male homosexuality or bisexuality. It includes indirect genetic influence which has now been shown to be present. It also includes the implications of infant male breast development in regard to sexuality. It is asserted that the major cause of male homosexuality is due to failure of masculinisation of the male brain due to temporary but critical prolactin secretion from microprolactinoma present in their pituitary glands. Genes appear to be involved in the production of these tumours and sometimes in their demise. The assessment of their numbers at any one time in infancy has not been correctly addressed. Secondly, there is absolutely compulsive evidence concerning increased male infant breast development and the true nature of "Witch's Milk" and how it is produced and the profound implications of its presence in male neonates. It adds much persuasion to the causation of male homosexuality as enunciated in this paper. Measurement of testosterone levels at exactly and precisely the right time, are able to predict homosexual or bisexual development in adults. This knowledge would be of great help to parents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Testosterone treatment diminishes sickness behavior in male songbirds.

PubMed

Ashley, Noah T; Hays, Quentin R; Bentley, George E; Wingfield, John C

2009-06-01

Males of many vertebrate species are typically more prone to disease and infection than female conspecifics, and this sexual difference is partially influenced by the immunosuppressive properties of testosterone (T) in males. T-induced immunosuppression has traditionally been viewed as a pleiotropic handicap, rather than an adaptation. Recently, it has been hypothesized that suppression of sickness behavior, or the symptoms of infection, may have adaptive value if sickness interferes with the expression of T-mediated behaviors important for male reproductive success. We conduct a classic hormone replacement experiment to examine if T suppresses sickness behavior in a seasonally-breeding songbird, Gambel's white-crowned sparrow (Zonotrichia leucophrys gambelii). Triggered experimentally by bacterial lipopolysaccharide (LPS), sickness behavior includes decreased activity, anorexia, and weight loss. Gonadectomized (GDX) males that were treated with silastic implants filled with T exhibited suppression of behavioral and physiological responses to LPS compared to GDX and sham-GDX controls given empty implants. Sickness responses of control groups were statistically indistinguishable. T-implanted birds had significantly higher plasma T than control groups and levels were within the range associated with aggressive interactions during male-to-male contests. These findings imply that suppression of sickness behavior could occur when T is elevated to socially-modulated levels. Alternatively, it is possible that this suppressive effect is mediated through a stress-induced mechanism, as corticosterone levels were elevated in T-implanted subjects compared to controls. We propose that males wounded and infected during contests may gain a brief selective advantage by suppressing sickness responses that would otherwise impair competitive performance. The cost of immunosuppression would be manifested in males through an increased susceptibility to disease, which is presumably

Reproductive inefficiency in male black-footed ferrets (Mustela nigripes).

PubMed

Wolf, K.N.; Wildt, D.E.; Vargas, A.; Marinari, P.E.; Ottinger, M.A.; Howard, J.G.

2000-01-01

The black-footed ferret (Mustela nigripes), once considered extinct, has benefited from captive breeding and subsequent reintroduction into native habitat. A high proportion of females (>90%) exhibit estrus in captivity during the spring breeding season. However, many males considered to be prime-breeding age (1-3 years old) fail to sire offspring. Breeding records in 1995 revealed that 40 of 73 males (55%) managed under the Black-Footed Ferret Species Survival Plan did not reproduce, despite being provided opportunity. The present study was conducted to determine the incidence and etiology of male reproductive failure in 1996 and 1997. In 1996, 38 of 69 (55%) 1- to 3-year-old males failed to sire offspring. Likewise, 35 of 60 (58%) males did not reproduce in 1997. Overall, 21% of adult males failed to sire young in three consecutive breeding seasons (1995-1997). Electroejaculate traits (ejaculate volume, sperm concentration, motility, morphology, and acrosomal integrity) from 29 proven breeder males were not different (P > 0.05) from those of 23 males that did not sire young (nonproven breeders). However, six categories of reproductive failure were identified for the 73 prime-breeding age, nonproven males: 1) underdeveloped testes (22%); 2) improper breeding position with the female (25%); 3) excessive aggression toward estrous females (9%); 4) copulation with no sperm detected at postcoital lavage (19%); 5) copulation with sperm in the vaginal lavage but no resulting pregnancy (18%); and 6) copulation with no vaginal lavage performed and no resulting pregnancy (7%). These data indicate that combined behavioral and physiologic factors, but not overall sperm quality, influence reproductive performance in male black-footed ferrets managed in captivity. Zoo Biol 19:517-528, 2000. Copyright 2000 Wiley-Liss, Inc.

Three-dimensional adult male head and skull contours.

PubMed

Lee, Calvin; Loyd, Andre M; Nightingale, Roger; Myers, Barry S; Damon, Andrew; Bass, Cameron R

2014-01-01

Traumatic brain injury (TBI) is a major public health issue, affecting millions of people annually. Anthropomorphic test devices (ATDs) and finite element models (FEMs) provide a means of understanding factors leading to TBI, potentially reducing the occurrence. Thus, there is a need to ensure that these tools accurately model humans. For example, the Hybrid III was not based on 3-dimensional human head shape data. The objective of this study is to produce average head and skull contours for an average U.S. male that can be used for ATDs and FEMs. Computed tomography (CT) scans of adult male heads were obtained from a database provided by the University of Virginia Center for Applied Biomechanics. An orthographic viewer was used to extract head and skull contours from the CT scans. Landmarks were measured graphically using HyperMesh (Altair, HyperWorks). To determine the head occipital condyle (OC) centroid, surface meshes of the OCs were made and the centroid of the surfaces was calculated. The Hybrid III contour was obtained using a MicroScribe Digitizer (Solution Technologies, Inc., Oella, MD). Comparisons of the average male and ATD contours were performed using 2 methods: (1) the midsagittal and midcoronal ATD contours relative to the OC centroid were compared to the corresponding 1 SD range of the average male contours; (2) the ATD sagittal contour was translated relative to the average male sagittal contour to minimize the area between the 2 contours. Average male head and skull contours were created. Landmark measurements were made for the dorsum sellae, nasion skin, nasion bone, infraorbital foramen, and external auditory meatus, all relative to the OC centroid. The Hybrid III midsagittal contour was outside the 1 SD range for 15.2 percent of the average male head contour but only by a maximum distance of 1.5 mm, whereas the Hybrid III midcoronal head contour was outside the 1 SD range for 12.2 percent of the average male head contour by a maximum distance

Engaging Black Males on Their Own Terms: What Schools Can Learn from Black Males Who Produce Hip-Hop

ERIC Educational Resources Information Center

Irby, Decoteau J.; Petchauer, Emery; Kirkland, David

2013-01-01

Education scholars and practitioners have much to learn about engagement and motivation of Black males by directing their inquiries to more organic sites of hip-hop cultural production outside of schools. One such site is the hip-hop's informal labor economy where Black males engage in earning money through hip-hop cultural production. Labor…

Expression of sunflower cytoplasmic male sterility-associated open reading frame, orfH522 induces male sterility in transgenic tobacco plants.

PubMed

Nizampatnam, Narasimha Rao; Doodhi, Harinath; Kalinati Narasimhan, Yamini; Mulpuri, Sujatha; Viswanathaswamy, Dinesh Kumar

2009-03-01

Sterility in the universally exploited PET1-CMS system of sunflower is associated with the expression of orfH522, a novel mitochondrial gene. Definitive evidence that ORFH522 is directly responsible for male sterility is lacking. To test the hypothesis that ORFH522 is sufficient to induce male sterility, a set of chimeric constructs were developed. The cDNA of orfH522 was cloned in-frame with yeast coxIV pre-sequence, and was expressed under tapetum-specific promoter TA29 (construct designated as TCON). For developing control vectors, orfH522 was cloned without the transit peptide under TA29 promoter (TON) or orfH522 was cloned with or without transit peptide under the constitutive CaMV35S promoter (SCOP and SOP). Among several independent transformants obtained with each of the gene cassettes, one third of the transgenics (6/17) with TCON were completely male sterile while more than 10 independent transformants obtained with each of the control vectors were fertile. The male sterile plants were morphologically similar to fertile plants, but had anthers that remained below the stigmatic surface at anthesis. RT-PCR analysis of the sterile plants confirmed the anther-specific expression of orfH522 and bright-field microscopy demonstrated ablation of the tapetal cell layer. Premature DNA fragmentation and programmed cell death was observed at meiosis stage in the anthers of sterile plants. Stable transmission of induced male sterility trait was confirmed in test cross progeny. This constitutes the first report at demonstrating the induction of male sterility by introducing orfH522 gene that could be useful for genetic engineering of male sterility.

Sex hormones and the elderly male voice.

PubMed

Gugatschka, Markus; Kiesler, Karl; Obermayer-Pietsch, Barbara; Schoekler, Bernadette; Schmid, Christoph; Groselj-Strele, Andrea; Friedrich, Gerhard

2010-05-01

The objective was to describe influences of sex hormones on the male voice in an elderly cohort. Sixty-three elderly males were recruited to undergo assessment of voice parameters, stroboscopy, voice-related questionnaires, a blood draw, and an ultrasound examination of the laryngeal skeleton. The group was divided into men with normal hormonal status and men with lowered levels of sex hormones, called hypogonades. Depending on the level of androgens, voice parameters did not differ. In subjects with decreased levels of estrogens, a significant increase in mean fundamental frequency, as well as changes of highest and lowest frequency plus a shift of the frequency range could be detected. We could detect significant changes of voice parameters depending on status of estrogens in elderly males. Androgens appear to have no impact on the elderly male voice. To our knowledge, this is the first prospective study that correlates sex hormones with voice parameters in elderly men. (c) 2010 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Zika Virus in the Male Reproductive Tract.

PubMed

Stassen, Liesel; Armitage, Charles W; van der Heide, David J; Beagley, Kenneth W; Frentiu, Francesca D

2018-04-16

Arthropod-borne viruses (arboviruses) are resurging across the globe. Zika virus (ZIKV) has caused significant concern in recent years because it can lead to congenital malformations in babies and Guillain-Barré syndrome in adults. Unlike other arboviruses, ZIKV can be sexually transmitted and may persist in the male reproductive tract. There is limited information regarding the impact of ZIKV on male reproductive health and fertility. Understanding the mechanisms that underlie persistent ZIKV infections in men is critical to developing effective vaccines and therapies. Mouse and macaque models have begun to unravel the pathogenesis of ZIKV infection in the male reproductive tract, with the testes and prostate gland implicated as potential reservoirs for persistent ZIKV infection. Here, we summarize current knowledge regarding the pathogenesis of ZIKV in the male reproductive tract, the development of animal models to study ZIKV infection at this site, and prospects for vaccines and therapeutics against persistent ZIKV infection.

Bladder catheterization, male (image)

MedlinePlus

... kept empty (decompressed) and urinary flow assured. The balloon holds the catheter in place for a duration of time. Catheterization in males is slightly more difficult and uncomfortable than in females because of the longer urethra.

Proteomic Analysis of Pachytene Spermatocytes of Sterile Hybrid Male Mice.

PubMed

Wang, Lu; Guo, Yueshuai; Liu, Wenjing; Zhao, Weidong; Song, Gendi; Zhou, Tao; Huang, Hefeng; Guo, Xuejiang; Sun, Fei

2016-09-01

Incompatibilities in interspecific hybrids, such as reduced hybrid fertility and lethality, are common features resulting from reproductive isolation that lead to speciation. Subspecies crosses of house mice produce offspring in which one sex is infertile or absent, yet the molecular mechanisms of hybrid sterility are poorly understood. In this study, we observed extensive asynapsis of chromosomes and disturbance of the sex body in pachytene spermatocytes of sterile F1 males (PWK/Ph female × C57BL/6J male). We report the high-confidence identification of 4005 proteins in the pachytene spermatocytes of fertile F1 males (PWK/Ph male × C57BL/6J female) and sterile F1 males (PWK/Ph female × C57BL/6J male), of which 215 were upregulated and 381 were downregulated. Bioinformatics analysis of the proteome led to the identification of 43 and 59 proteins known to be essential for male meiosis and spermatogenesis in mice, respectively. Characterization of the proteome of pachytene spermatocytes associated with hybrid male sterility provides an inventory of proteins that is useful for understanding meiosis and the mechanisms of hybrid male infertility. © 2016 by the Society for the Study of Reproduction, Inc.

Biology of male fertility control: an overview of various male contraceptive approaches.

PubMed

Tulsiani, D R; Abou-Haila, A

2015-04-01

The population of our planet continues to grow at an alarming rate. If the growth continues at the present rate, the estimated current world population of about seven billion is expected to double in the next forty years. Accumulated data from surveys by the United Nations Population Control Division suggest that a majority of today's young men in many countries are willing to have fewer children than their parents did. However, the contraceptive options available to them have not changed in several decades. In spite of the general agreement that men, like women, must take full responsibility of their fertility, the availability of safe, reversible and affordable contraceptives for men have lagged behind because of the complexity of the science of the male reproductive system. Thus, the contraceptive needs of millions of men/couples go unmet every single day and results in millions of unwanted pregnancies. In this article, we intend to discuss new hormonal and non-hormonal contraceptive approaches that are at various stages of research and development and may someday provide new contraceptives for men. In addition, we intend to discuss many details of three safe, effective, affordable and reversible vas-based approaches that are inching closer to being approved for use by millions of men in multiple countries. Finally, our intention is to discuss the male contraceptive pill that will soon be available to men only in Indonesia. The availability of these male contraceptives will allow both men and women to take full control of their fertility and participate in slowing down the growth of world population.

Systems Toxicology of Male Reproductive Development ...

EPA Pesticide Factsheets

Adverse trends in male reproductive health have been reported for increased rates of testicular germ cell tumor, low semen quality, cryptorchidism, and hypospadias. An association with prenatal environmental exposure has been inferred from human and animal studies underlying male reproductive developmental defects. The present study established the links between environmental chemicals, molecular targets, and adverse outcomes using U.S. EPA animal study (ToxRefDB) and high-throughput screening (ToxCast) databases. This systems-based approach revealed a phenotypic hierarchy across 63 chemicals and a pleiotropic in vitro bioactivity profile. Although estrogenic and anti-androgenic activities have been extensively studied in male reproductive developmental toxicity, the present study showed these receptor targets to be only a subset of the potential landscape of molecular targets. A variety of chemical (e.g. phthalates, conazoles, carbamates, and phenol compounds) and bioactivity (e.g. nuclear receptors, vascular remodeling proteins, and cytochrome-P450 reductases) clusters further suggested multiple pathways leading to the adverse outcomes. This points to the need for multi-scale systems models to predict whether the occurrence of one adverse outcome may predict the risk of another. Imbalances in androgen and estrogen signaling have been a general focus in male reproductive toxicology research. While a number of recent studies have demonstrated that both hormonal

Male facial appearance signals physical strength to women.

PubMed

Fink, Bernhard; Neave, Nick; Seydel, Hanna

2007-01-01

Previous studies showed that male faces with extreme features that are likely to be associated with testosterone (T) are perceived as dominant and masculine. Women were reported to prefer masculinized male faces, as they may consider T markers to be an "honest" indication of good health. However, it is also likely that female preferences for certain male faces arise from the fact that dominant- and masculine-looking males are signaling characteristics which may be beneficial in intrasexual conflict, and thereby also indicate potential achievers of high status, an important factor in female mate selection. Although numerous studies were built on this assumption, nothing is known about the relationship between perceived facial dominance and physical strength in men. We measured hand-grip strength, as a measure of overall physical strength, in a sample of 32 male students, and recorded age, body weight, and height. Seventy-nine women rated facial images of these men for dominance, masculinity, and attractiveness. After controlling for age and body weight, hand-grip strength was found to correlate significantly positively with all three measures. The present data thus support the supposition that a male's physical strength is also signaled via facial characteristics of dominance and masculinity, which are considered attractive by women.

Ageing and inflammation in the male reproductive tract.

PubMed

Frungieri, M B; Calandra, R S; Bartke, A; Matzkin, M E

2018-05-08

Ageing is usually characterised by a mild chronic proinflammatory state. Despite the tight association between both processes, the phenomenon has recently been termed inflammageing. Inflammation in the male reproductive tract is frequently linked with bacterial or virus infections but also with a broad range of noninfectious processes. Prostatitis, epididymitis and orchitis, among others, can lead to infertility. However, in spite of the inflammation theory of disease, chronic inflammation in male urogenital system does not always cause symptoms. With advancing age, inflammatory processes are commonly observed in the male reproductive tract. Nevertheless, the incidence of inflammation in reproductive organs and ducts varies greatly among elderly men. Inflammageing is considered a predictor of pathogenesis and the development of age-related diseases. This article briefly summarises the current state of knowledge on inflammageing in the male reproductive tract. Yet, the precise aetiology of inflammageing in the male urogenital system, and its potential contribution not only to infertility but most importantly to adverse health outcomes remains almost unknown. Thus, further investigations are required to elucidate the precise cross-links between inflammation and male reproductive senescence, and to establish the impact of anti-inflammatory drug treatments on elder men's general health status. © 2018 Blackwell Verlag GmbH.

Perceptions of Credibility of Male and Female Syndicated Political Columnists.

ERIC Educational Resources Information Center

Andsager, Julie L.

1990-01-01

Examines perceptions of the credibility of male and female syndicated political columnists. Finds that college students exhibited little prejudice against female versus male bylines in political interpretive columns. Finds a small tendency for male readers to evaluate male bylines higher in stereotypical ways, but female readers do not do this.…

Educating African American Males: A Dream Deferred.

ERIC Educational Resources Information Center

Milwaukee Public Schools, WI.

This document presents recommendations of the Milwaukee (Wisconsin) African American Male Task Force (MAAMTF), which reviewed from January through April of 1990 current educational efforts and recommended strategies by which schools could better address African American males' needs. The MAAMTF recommendations are to be implemented in two phases.…

[Research progress on molecular genetics of male homosexuality].

PubMed

Tu, Dan; Xu, Ruiwei; Zhao, Guanglu; Wang, Binbin; Feng, Tiejian

2016-08-01

Sexual orientation is influenced by both environmental factors and biological factors. Family and twin studies have shown that genetic factors play an important role in the formation of male homosexuality. Genome-wide scan also revealed candidate chromosomal regions which may be associated with male homosexuality, but so far no clearly related genes have been found. This article reviews the progress of relevant studies and candidate genes which are related to male homosexuality.

Males and Eating Disorders

MedlinePlus

... Bar Home Current Issue Past Issues Males and Eating Disorders Past Issues / Spring 2008 Table of Contents For ... this page please turn Javascript on. Photo: PhotoDisc Eating disorders primarily affect girls and women, but boys and ...

Sensory regulation of C. elegans male mate-searching behaviour

PubMed Central

Barrios, Arantza; Nurrish, Stephen; Emmons, Scott W.

2009-01-01

Summary How do animals integrate internal drives and external environmental cues to coordinate behaviours? We address this question studying mate-searching behaviour in C. elegans. C. elgans males explore their environment in search of mates (hermaphrodites) and will leave food if mating partners are absent. However, when mates and food coincide, male exploratory behaviour is suppressed and males are retained on the food source. We show that the drive to explore is stimulated by male specific neurons in the tail, the ray neurons. Periodic contact with the hermaphrodite detected through ray neurons changes the male’s behaviour during periods of no contact and prevents the male from leaving the food source. The hermaphrodite signal is conveyed by male-specific interneurons that are post-synaptic to the rays and that send processes to the major integrative center in the head. This study identifies key parts of the neural circuit that regulates a sexual appetitive behaviour in C. elegans. PMID:19062284

Male-on-male intimate partner violence and sexual risk behaviors among money boys and other men who have sex with men in Shanghai, China.

PubMed

Dunkle, Kristin L; Wong, Frank Y; Nehl, Eric J; Lin, Lavinia; He, Na; Huang, Jennifer; Zheng, Tony

2013-05-01

Intimate partner violence (IPV) is known to increase HIV risk among heterosexual women, but less is known about IPV and HIV among men who have sex with men (MSM), with almost no data from non-Western countries. This study examined the prevalence of IPV and links between IPV and HIV risks among MSM in Shanghai, China. A cross-sectional sample of 404 money boys (male sex workers) and other MSM were recruited via respondent-driven sampling. Overall, 51% of the sample reported emotional, physical, or sexual abuse from a male sexual partner. Money boys reported more overall abuse than did other MSM, and more were likely than other MSM to report experiencing multiple types of abuse. MSM who reported violence or abuse from male partners reported more overall sexual risk behavior, and specifically, more unprotected sex and more sex linked to alcohol and other substance use. The association between experience of abuse from male partners and increased HIV risk did not differ between money boys and other Chinese MSM. We conclude that violence and abuse from male partners are highly prevalent among Chinese MSM, and that experience of violence from male sexual partners is linked to increased HIV risk. HIV prevention targeting Chinese MSM must address the increased risk associated with experience of male-on-male IPV. Future research should explore links between HIV risk and MSM's perpetration of violence against male partners, as well as exploring the role of violence in the male-female relationships of men who have sex with and men and women.

Self-efficacy, male rape myth acceptance, and devaluation of emotions in sexual trauma sequelae: Findings from a sample of male veterans.

PubMed

Voller, Emily; Polusny, Melissa A; Noorbaloochi, Siamak; Street, Amy; Grill, Joseph; Murdoch, Maureen

2015-11-01

Sexual trauma is an understudied but regrettably significant problem among male Veterans. As in women, sexual trauma often results in serious mental health consequences for men. Therefore, to guide potential future interventions in this important group, we investigated associations among self-efficacy, male rape myth acceptance, devaluation of emotions, and psychiatric symptom severity after male sexual victimization. We collected data from 1,872 Gulf War era Veterans who applied for posttraumatic stress disorder (PTSD) disability benefits using standard mailed survey methods. The survey asked about history of childhood sexual abuse, sexual assault during the time of Gulf War I, and past-year sexual assault as well as Veterans' perceived self-efficacy, male rape myth acceptance, devaluation of emotions, PTSD, and depression symptoms. Structural equation modeling revealed that self-efficacy partially mediated the association between participants' sexual trauma history and psychiatric symptoms. Greater male rape myth acceptance and greater devaluation of emotions were directly associated with lower self-efficacy, but these beliefs did not moderate associations between sexual trauma and self-efficacy. In this population, sexual trauma, male rape myth acceptance, and devaluation of emotions were associated with lowered self-efficacy, which in turn was associated with more severe psychiatric symptoms. Implications for specific, trauma-focused treatment are discussed. (c) 2015 APA, all rights reserved).

Improving Educational Outcomes for Minority Males in Our Schools

ERIC Educational Resources Information Center

Gardner, Ralph, III; Rizzi, Gleides Lopes; Council, Morris, III

2014-01-01

This article examines the academic underachievement and disproportionate special education placement of minority males. Causes and consequences for poor academic performance by minority males are reviewed. The Individuals with Disabilities Education Act and No Child Left Behind Act are discussed in relation to minority male academic achievement.…

Females exceed males in mercury concentrations of burbot Lota lota

USGS Publications Warehouse

Madenjian, Charles P.; Stapanian, Martin A.; Cott, Peter A.; Krabbenhoft, David P.; Edwards, William; Ogilvie, Lynn M.; Mychek-Londer, Justin G.; DeWild, John F.

2015-01-01

Examination of differences in contaminant concentrations between sexes of fish, across several fish species, may reveal clues for important behavioral and physiological differences between the sexes. We determined whole-fish total mercury (Hg) concentrations of 25 male and 25 female adult burbot Lota lota captured in Lake Erie during summer 2011, and of 14 male and 18 female adult burbot captured in Great Slave Lake (Northwest Territories, Canada) during winter 2013. On average, females were 22 % greater in Hg concentration than males. This difference was probably not due to a greater feeding rate by females, because results from previous studies based on polychlorinated biphenyl (PCB) determinations of these same burbot indicated that males fed at a substantially greater rate than females. Based on our determinations of Hg concentrations in the gonads and somatic tissue of five ripe females and five ripe males, this difference was not attributable to changes in Hg concentration immediately after spawning due to release of gametes. Further, bioenergetics modeling results from previous studies indicated that growth dilution would not explain any portion of this observed difference in Hg concentrations between the sexes. We, therefore, conclude that this difference was most likely due to a substantially faster rate of Hg elimination by males compared with females. Male burbot exhibit among the greatest gonadosomatic indices (GSIs) of all male fishes, with their testes accounting for between 10 and 15 % of their body weight when the fish are in ripe condition. Androgens have been linked to enhanced Hg elimination rates in other vertebrates. If androgen production is positively related to GSI, then male burbot would be expected to have among the greatest androgen levels of all fishes. Thus, we hypothesize that male burbot eliminate Hg from their bodies faster than most other male fishes, and this explains the greater Hg concentration in females compared with males.

Comparison of circadian rhythms in male and female humans

NASA Technical Reports Server (NTRS)

Winget, C. M.; Deroshia, C. W.; Vernikos-Danellis, J.; Rosenblatt, W. S.; Hetherington, N. W.

1977-01-01

Heart rate (HR) and rectal temperature (RT) data were obtained from 12 female and 27 male subjects. The subjects were housed in a facility where the environment was controlled. Human male and female RT and HR exhibit a circadian rhythm with an excursion of about 1.2 C and 30 beats/min, respectively. The acrophases, amplitudes, and level crossings are only slightly different between the sexes. The male HR and RT circadian wave forms are more stable than those of the females. However, the actual RT and HR of males were always lower than that of females at all time points around the clock. The HR during sleep in females is 15 per cent below the daily mean heart rate and in males, 22 per cent.

The Decision for Male versus Female Sterilization.

ERIC Educational Resources Information Center

Clark, Margaret Pruitt; And Others

1979-01-01

The increasing popularity of sterilization underscores the need for knowledge about couples choosing male and female procedures. This research delineates four sets of variables that may be important for the decision and examines their relationship with the choice of male or female procedure among a sample of married couples. (Author)

Black Males in College: An Endangered Species?

ERIC Educational Resources Information Center

Fuhrmann, Barbara S.; And Others

Because relatively few black males successfully complete college, this study sought to determine how black male freshmen at a predominantly white university differed from other freshmen in their values, aspirations, and assumptions about college life. In the fall of 1989, the ACT Entering Student Survey, plus 30 locally developed questions, was…

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…

Teaching About Women to Male-Identified Students.

ERIC Educational Resources Information Center

Turkel, Kathleen Doherty

1986-01-01

The female students taking women's studies courses today are different from those in the early 1970s. Many are unconsciously male-identified--fully buying into predominant male viewpoints--and thus fail to recognize the connections which exist between the general conditions restricting the opportunities and welfare of women and their own…

The Changing Experiences of Bisexual Male Adolescents

ERIC Educational Resources Information Center

Morris, Max; McCormack, Mark; Anderson, Eric

2014-01-01

Drawing on in-depth interviews with 15 openly bisexual male youth from sixth forms across the UK, this article documents positive experiences of bisexual male youth in school: participants had positive coming out experiences and did not encounter significant discrimination or harassment because of their sexual identity. Participants attribute this…

Male Communication Problems in the Student Body.

ERIC Educational Resources Information Center

Borisoff, Deborah

This paper summarizes seven "truths" imparted about male sex traits and sex-role stereotypes that stem from extant research reflecting primarily a dual-culture perspective. The paper includes relevant research findings and insights from male students that suggest that some of the conclusions about men's communication should be revisited.…

Gifted Male Readers: Current Understandings and Suggestions for Future Research

ERIC Educational Resources Information Center

Pagnani, Alexander R.

2013-01-01

Research literature concerning gifted male readers relies primarily on more extensive bodies of work regarding gifted males and male readers. Studied as a whole, the two halves portray a worrisome state of affairs for gifted male readers, who lag behind their female counterparts in the same patterns found across the ability spectrum. This literacy…

Spontaneous male death during copulation in an orb-weaving spider.

PubMed Central

Foellmer, Matthias W; Fairbairn, Daphne J

2003-01-01

Males of some cannibalistic species of spiders and insects appear to sacrifice themselves by allowing the female to eat them, and the adaptive significance of such drastic terminal reproductive investment has recently been demonstrated for a spider. Typically, the female has to kill the male, but it has been suggested that males of some species in the cannibalistic orb-weaving spider genus Argiope may die in copula without female 'collaboration'. Here, we provide the first experimental evidence to our knowledge of programmed sudden death after onset of copulation in males of the spider Argiope aurantia. Our observations reveal that males invariably die during the insertion of their second pedipalp, regardless of whether they mate with newly moulted, defenceless females or with older mature females that often attack them. We determined experimentally that the death of males is triggered immediately upon insertion of the second palp, when males become unresponsive, and heartbeat ceases within minutes of insertion. We discuss the possible adaptive significance of programmed death during copulation, and argue that male death has evolved in a context other than sexual cannibalism. PMID:14667377

Fertility of the male alpaca: effect of daily consecutive breeding.

PubMed

Bravo, P W; Solis, P; Ordoñez, C; Alarcon, V

1997-04-01

The fertility of the male alpaca under different frequencies of daily consecutive matings was evaluated. Fifteen adult male Huacaya alpacas were divided randomly into three groups of five each to breed lactating female alpacas. The schedule of daily matings was two, four and six consecutive breeding per group and for nine consecutive days. Ovulation was determined by progesterone at seven days after breeding. Pregnancy was determined by ultrasonography at 15 and 30 days after breeding. Two hundred and eighty females were bred with some males not fulfilling their schedule of breeding. There were differences (P < 0.05) in the fertility rate of males breeding two and four times daily (76%) in contrast to 59% for males breeding six times. There were also differences (P < 0.05) in the fertility of individual males. Length of copulation was affected (P < 0.05) by schedule of matings, day of breeding and male. Ovulation was independent of length of copulation. Overall, it seems the fertility of the male alpaca is affected significantly when consecutive matings are over four times a day and for nine consecutive days.

Gene-environment interaction and male reproductive function

PubMed Central

Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L.; Rylander, Lars; Giwercman, Aleksander

2010-01-01

As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism, but the number of studies is still limited. This type of interaction studies may improve our understanding of normal physiology and help us to identify the risk factors to male reproductive malfunction. We also shortly discuss other aspects of gene-environment interaction specifically associated with the issue of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity in the offspring. PMID:20348940

Dispersal of Engineered Male Aedes aegypti Mosquitoes.

PubMed

Winskill, Peter; Carvalho, Danilo O; Capurro, Margareth L; Alphey, Luke; Donnelly, Christl A; McKemey, Andrew R

2015-11-01

Aedes aegypti, the principal vector of dengue fever, have been genetically engineered for use in a sterile insect control programme. To improve our understanding of the dispersal ecology of mosquitoes and to inform appropriate release strategies of 'genetically sterile' male Aedes aegypti detailed knowledge of the dispersal ability of the released insects is needed. The dispersal ability of released 'genetically sterile' male Aedes aegypti at a field site in Brazil has been estimated. Dispersal kernels embedded within a generalized linear model framework were used to analyse data collected from three large scale mark release recapture studies. The methodology has been applied to previously published dispersal data to compare the dispersal ability of 'genetically sterile' male Aedes aegypti in contrasting environments. We parameterised dispersal kernels and estimated the mean distance travelled for insects in Brazil: 52.8 m (95% CI: 49.9 m, 56.8 m) and Malaysia: 58.0 m (95% CI: 51.1 m, 71.0 m). Our results provide specific, detailed estimates of the dispersal characteristics of released 'genetically sterile' male Aedes aegypti in the field. The comparative analysis indicates that despite differing environments and recapture rates, key features of the insects' dispersal kernels are conserved across the two studies. The results can be used to inform both risk assessments and release programmes using 'genetically sterile' male Aedes aegypti.

Pediatric sports injuries: a comparison of males versus females.

PubMed

Stracciolini, Andrea; Casciano, Rebecca; Levey Friedman, Hilary; Stein, Cynthia J; Meehan, William P; Micheli, Lyle J

2014-04-01

There is still much that we do not know about differences in sports injuries between young male and female athletes and the factors that may increase the risk for injuries in this regard. To describe and compare differences between males and females in pediatric sports-related injuries. Cross-sectional study; Level of evidence, 3. A retrospective chart review was performed using a 5% random sampling (N = 2133) of medical records of children aged 5 to 17 years seen over 10 years in a sports medicine clinic at a large academic pediatric hospital. Information was collected and analyzed on age, sex, height, weight, injury type (overuse vs acute/traumatic), location of injury, and sports involvement. Overall, female athletes had a higher percentage of overuse injuries (62.5%) compared with traumatic injuries (37.5%); the opposite was seen in male athletes (41.9% vs. 58.2%, respectively; P < .001). Looking at specific areas of injury, female athletes sustained more injuries to the lower extremity (65.8%) and spine (11.3%) as compared with male athletes (53.7% and 8.2%, respectively). Male patients had a greater percentage of injuries to the upper extremity (29.8%) as compared with female patients (15.1%). The type of hip/pelvis injuries differed greatly by sex, with females sustaining more overuse (90.9%) and soft tissue injuries (75.3%) versus males, who suffered injuries that tended to be traumatic (58.3%) and bony (55.6%) in nature. Males were more likely than females to participate in team and contact/collision sports. The percentage of females with patellofemoral knee pain was approximately 3 times greater than that of males (14.3% vs. 4.0%, respectively; P < .001). Males were twice as likely as females to be diagnosed with osteochondritis dissecans (8.6% vs. 4.3%, respectively; P < .001) and fractures (19.5% vs. 8.2%, respectively; P < .001). The percentage of males and females who sustained an anterior cruciate ligament injury was almost equal (10.0% and 8

Chromosomal disorders and male infertility

PubMed Central

Harton, Gary L; Tempest, Helen G

2012-01-01

Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain largely undiscovered. Nevertheless, more and more genetic factors associated with infertility are being identified. This review will focus on our current understanding of the chromosomal basis of male infertility specifically: chromosomal aneuploidy, structural and numerical karyotype abnormalities and Y chromosomal microdeletions. Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans. Aneuploidy is predominantly maternal in origin, but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts. Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm. Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed, as well as the application of preimplantation genetic diagnosis (PGD) in such cases. Clinical recommendations where possible will be made, as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility. PMID:22120929

Chromosomal disorders and male infertility.

PubMed

Harton, Gary L; Tempest, Helen G

2012-01-01

Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain largely undiscovered. Nevertheless, more and more genetic factors associated with infertility are being identified. This review will focus on our current understanding of the chromosomal basis of male infertility specifically: chromosomal aneuploidy, structural and numerical karyotype abnormalities and Y chromosomal microdeletions. Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans. Aneuploidy is predominantly maternal in origin, but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts. Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm. Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed, as well as the application of preimplantation genetic diagnosis (PGD) in such cases. Clinical recommendations where possible will be made, as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.

Male Diaphorina citri searching responses to vibrational communication signals

USDA-ARS?s Scientific Manuscript database

Prototype devices have been developed that mimic D. citri female replies to male communication signals and lure males to a trap. The objective is to trap a high proportion of males that have landed on a host tree and have begun searching for females. This presentation describes the construction and ...

Amygdala and socio-sexual behavior in male zebra finches.

PubMed

Ikebuchi, Maki; Hasegawa, Toshikazu; Bischof, Hans-Joachim

2009-01-01

Neuroanatomical studies including pathway tracing and cytochemical characterizations have suggested that the avian nucleus taeniae of the amygdala (TnA) might be homologous to a part of the mammalian medial amygdala. Recent behavioral observations in TnA-lesioned birds also reported deficits in the control of motivational aspects of behavior, advancing the concept of homology of the structure in the two classes of animals. To further examine the functional role of TnA, we used a highly social, monogamous song bird species, the zebra finch, for our experiments. Male birds received a focal lesion of TnA, and several aspects of socio-sexual behavior of these animals were compared with control bird behavior. We found that zebra finch males with TnA lesions were never chosen as sexual partners by a female in a triadic situation with another male because they showed less sexually motivated behavior. Because such sexually motivated behavior was shown in dyadic situations with a lesioned male and a female, however, and females in this situation also showed pair bonding behavior towards the lesioned males, TnA might be involved in other behaviors, not just sexual behavior towards females. Instead, it might play a role in the control of a variety of social encounters including male-female and male-male interactions. This research clearly indicates that TnA, by its involvement in the control of socio-sexual behavior, is functionally comparable with the mammalian medial amygdala. 2009 S. Karger AG, Basel.

Do Tetranychus urticae males avoid mating with familiar females?

PubMed

Yoshioka, T; Yano, S

2014-07-01

The two-spotted spider mite, Tetranychus urticae, usually lives in kin groups under common webs. Because only the first mating results in fertilisation in female T. urticae, adult males guard quiescent deutonymph females, those at the stage immediately before maturation, to ensure paternity. Therefore, the cost of precopulatory guarding time seems considerable for males. Moreover, the fitness indices of daughters from intra-population crosses were significantly lower than those of daughters from inter-population crosses, indicating that inbreeding depression exists in T. urticae. Therefore, we hypothesised that T. urticae males should be choosy in guarding familiar females to avoid inbreeding depression. Furthermore, webs should be a key element of the environment shared by familiar individuals. In this study, we demonstrated the inbreeding avoidance mechanism of T. urticae males in relation to webs produced by familiar females (known webs) or unfamiliar females (unknown webs). Regardless of surrounding webs (known or unknown), males preferred unfamiliar to familiar females. We further examined whether males detect unfamiliar females by their webs. When males had experienced a female's web without encountering that female, they subsequently preferred females that did not produce the surrounding webs in which the choice experiment was conducted. Results suggest that putative kin recognition for inbreeding avoidance in T. urticae males is based on the relationship between webs and females, and not on the discrimination of webs in shared environments. © 2014. Published by The Company of Biologists Ltd.

Polygyny, mate-guarding, and posthumous fertilization as alternative male mating strategies.

PubMed

Zamudio, K R; Sinervo, B

2000-12-19

Alternative male mating strategies within populations are thought to be evolutionarily stable because different behaviors allow each male type to successfully gain access to females. Although alternative male strategies are widespread among animals, quantitative evidence for the success of discrete male strategies is available for only a few systems. We use nuclear microsatellites to estimate the paternity rates of three male lizard strategies previously modeled as a rock-paper-scissors game. Each strategy has strengths that allow it to outcompete one morph, and weaknesses that leave it vulnerable to the strategy of another. Blue-throated males mate-guard their females and avoid cuckoldry by yellow-throated "sneaker" males, but mate-guarding is ineffective against aggressive orange-throated neighbors. The ultradominant orange-throated males are highly polygynous and maintain large territories; they overpower blue-throated neighbors and cosire offspring with their females, but are often cuckolded by yellow-throated males. Finally, yellow-throated sneaker males sire offspring via secretive copulations and often share paternity of offspring within a female's clutch. Sneaker males sire more offspring posthumously, indicating that sperm competition may be an important component of their strategy.

Polygyny, mate-guarding, and posthumous fertilization as alternative male mating strategies

PubMed Central

Zamudio, Kelly R.; Sinervo, Barry

2000-01-01

Alternative male mating strategies within populations are thought to be evolutionarily stable because different behaviors allow each male type to successfully gain access to females. Although alternative male strategies are widespread among animals, quantitative evidence for the success of discrete male strategies is available for only a few systems. We use nuclear microsatellites to estimate the paternity rates of three male lizard strategies previously modeled as a rock-paper-scissors game. Each strategy has strengths that allow it to outcompete one morph, and weaknesses that leave it vulnerable to the strategy of another. Blue-throated males mate-guard their females and avoid cuckoldry by yellow-throated “sneaker” males, but mate-guarding is ineffective against aggressive orange-throated neighbors. The ultradominant orange-throated males are highly polygynous and maintain large territories; they overpower blue-throated neighbors and cosire offspring with their females, but are often cuckolded by yellow-throated males. Finally, yellow-throated sneaker males sire offspring via secretive copulations and often share paternity of offspring within a female's clutch. Sneaker males sire more offspring posthumously, indicating that sperm competition may be an important component of their strategy. PMID:11106369

The Success of Vocationally Trained Women in Traditionally Male Occupations.

ERIC Educational Resources Information Center

Pucel, David J.

A study was conducted to examine the ability of women who enroll in traditionally male occupations to receive equal training and equal employment benefits to those of males enrolled in the same programs. (A traditionally male occupation was defined as an occupation which employed 80% or more males.) The eight programs included in the study were…

Artificial selection on male genitalia length alters female brain size.

PubMed

Buechel, Séverine D; Booksmythe, Isobel; Kotrschal, Alexander; Jennions, Michael D; Kolm, Niclas

2016-11-30

Male harassment is a classic example of how sexual conflict over mating leads to sex-specific behavioural adaptations. Females often suffer significant costs from males attempting forced copulations, and the sexes can be in an arms race over male coercion. Yet, despite recent recognition that divergent sex-specific interests in reproduction can affect brain evolution, sexual conflict has not been addressed in this context. Here, we investigate whether artificial selection on a correlate of male success at coercion, genital length, affects brain anatomy in males and females. We analysed the brains of eastern mosquitofish (Gambusia holbrooki), which had been artificially selected for long or short gonopodium, thereby mimicking selection arising from differing levels of male harassment. By analogy to how prey species often have relatively larger brains than their predators, we found that female, but not male, brain size was greater following selection for a longer gonopodium. Brain subregion volumes remained unchanged. These results suggest that there is a positive genetic correlation between male gonopodium length and female brain size, which is possibly linked to increased female cognitive ability to avoid male coercion. We propose that sexual conflict is an important factor in the evolution of brain anatomy and cognitive ability. © 2016 The Author(s).

Do pheromones reveal male immunocompetence?

PubMed Central

Rantala, Markus J; Jokinen, Ilmari; Kortet, Raine; Vainikka, Anssi; Suhonen, Jukka

2002-01-01

Pheromones function not only as mate attractors, but they may also relay important information to prospective mates. It has been shown that vertebrates can distinguish, via olfactory mechanisms, major histocompatibility complex types in their prospective mates. However, whether pheromones can transmit information about immunocompetence is unknown. Here, we show that female mealworm beetles (Tenebrio molitor) prefer pheromones from males with better immunocompetence, indicated by a faster encapsulation rate against a novel antigen, and higher levels of phenoloxidase in haemolymph. Thus, the present study indicates that pheromones could transmit information about males' parasite resistance ability and may work as a reliable sexual ornament for female choice. PMID:12204128

Behaviour of Arctic charr Salvelinus alpinus during an induced mating season in captivity: how male relative size influences male behavioural investment and female preference over time.

PubMed

Bolgan, M; O'Brien, J; Picciulin, M; Manning, L; Gammell, M

2017-04-01

The behaviour of sexually mature Arctic charr Salvelinus alpinus specimens (fifth farm generation) was observed in captivity for four consecutive days. Only agonistic interactions between males of different size were facilitated on the first 2 days, while both agonistic and courtship interactions were possible from the third day up to the end of the experiment. The reliability of behavioural analysis was assessed in order to reduce the possibility of observer errors within the generated datasets. The behavioural investment of big males, small males and females was analysed using general linear models (two-way repeated measures ANOVAs with time and male size as factors). A peak in the agonistic interactions between males occurred during the first day of interactions, where the agonistic investment of big males was significantly higher than that of small males. This resulted in an increased investment in submissive behaviour by the small males, who consistently performed submissive behaviours from the second day of interactions up to the end of the trial. Big males were found to invest significantly more than small males in courtship behaviours for the duration of the trial. Even though females performed inter-sexual behaviours towards both big and small males for the entire observation period, female interaction rate towards big males was higher than towards small males. This study suggests that both male investment in mating behaviour and female preference might be related to male characteristics such as body length and that S. alpinus behavioural patterns and mate choice cues might be strongly context-related and characterized by high levels of behavioural plasticity (i.e. presence-absence of certain behavioural units or potential reversal of a mate choice cue) within the same species. Finally, in light of this, some conservation measures are discussed. In particular, effective management plans should take into account the high level of behavioural plasticity

Sexual Arousal Patterns of Autogynephilic Male Cross-Dressers.

PubMed

Hsu, Kevin J; Rosenthal, A M; Miller, David I; Bailey, J Michael

2017-01-01

Men's sexual arousal patterns have been an important window into the nature of their erotic interests. Autogynephilia is a natal male's paraphilic tendency to be sexually aroused by the thought or image of being a woman. Autogynephilic arousal per se is difficult to assess objectively, because it is inwardly focused. However, assessing sexual arousal patterns of autogynephilic males in response to external stimuli is also potentially useful. For example, there is substantial association between autogynephilia and gynandromorphophilia (GAMP), or sexual attraction to gynandromorphs (GAMs), colloquially "she-males." GAMP men's sexual arousal patterns in response to GAM, female, and male stimuli have recently been characterized. In the present study, we extended this understanding by comparing the sexual arousal patterns of autogynephilic male cross-dressers, GAMP men, heterosexual men, and homosexual men. Erotic stimuli included sexually explicit videos of men, women, and GAMs. Autogynephilic men were much more similar in their arousal patterns to heterosexual and GAMP men than to homosexual men. However, similar to GAMP men, autogynephilic men showed increased arousal by GAM stimuli relative to female stimuli compared with heterosexual men.

What does testosterone do for red deer males?

PubMed Central

Malo, A.F.; Roldan, E.R.S.; Garde, J.J.; Soler, A.J.; Vicente, J.; Gortazar, C.; Gomendio, M.

2008-01-01

Testosterone has been proposed to have a dual effect, enhancing sexual traits while depressing parasite resistance in males. Here, we test this hypothesis in red deer, examining males from captive populations during the whole annual cycle and males from natural populations during the breeding season. We first explored the effects of body size, age and sampling date on testosterone to avoid confounding effects. Our results show that in captive populations seasonal changes in testosterone levels were mirrored by changes in testes size, and that during the rut there was a strong correlation between both. In natural populations, males with higher testosterone levels had larger testes, improved sperm quality, smaller burr diameter, stronger antlers, higher haematocrit levels, and increased nematode parasite load. By contrast, no significant relationship was found between testosterone and spleen size or tick parasite load. We conclude that testosterone (i) improves males' reproductive investment and physical stamina, (ii) improves antler strength but reduces burr diameter, and (iii) imposes a cost in terms of depressed parasite resistance. PMID:19129132

The Vanishing Latino Male in Higher Education

ERIC Educational Resources Information Center

Saenz, Victor B.; Ponjuan, Luis

2009-01-01

Latino male students are "vanishing" from the American education pipeline, a trend that is especially evident at the secondary and postsecondary levels. The question of why Latino males are vanishing from America's colleges is complex, and this scholarly article explores some of the socio-cultural factors, peer dynamics, and labor force demands…

Why do Adolescent Girls Idolize Male Celebrities?

ERIC Educational Resources Information Center

Engle, Yuna; Kasser, Tim

2005-01-01

Girls often idolize male celebrities, but this phenomenon has been studied little. The authors therefore assessed celebrity idolization among 142 junior high school girls and found that girls who strongly idolized a male celebrity had more experience dating, reported secure and preoccupied attachments to same-age boys, and were rated higher in…

Aesthetic surgery of the male genitalia.

PubMed

Alter, Gary J; Salgado, Christopher J; Chim, Harvey

2011-08-01

Appearance of the male genitalia is linked with self-esteem and sexual identity. Aesthetic surgery of the male genitalia serves to correct perceived deficiencies as well as physical deformities, which may cause psychological distress. Attention to patient motivation for surgery and to surgical technique is key to achieving optimal results. In this review, the authors describe aesthetic surgical techniques for treatment of penile and scrotal deficiencies. They also discuss techniques for revision in patients with previous surgery.

Female perception of male body odor.

PubMed

Sergeant, Mark J T

2010-01-01

Olfaction is one of the most crucial forms of communication among nonhuman animals. Historically, olfaction has been perceived as being of limited importance for humans, but recent research has documented that not only do humans have sensitive olfactory abilities, but also odors have the potential to influence our physiology and behavior. This chapter reviews research on olfactory communication among humans, focusing on the effects of male bodily odors on female physiology and behavior. The process of body odor production and the detection of olfactory signals are reviewed, focusing on potential sex differences in these abilities. The effects of male body odors on female physiological and behavioral effects of body odors are considered. Finally, with specific regard to female mate choice, evidence regarding the influence of the major histocompatibility complex and fluctuating asymmetry on male olfactory cues is reviewed. Copyright © 2010 Elsevier Inc. All rights reserved.

New frontiers in nonhormonal male contraception

PubMed Central

Cheng, C. Yan; Mruk, Dolores D.

2015-01-01

The world’s population is nearing 6.8 billion, and we are in need of a male contraceptive that is safe, effective, reversible and affordable. Hormonal approaches, which employ different formulations of testosterone administered in combination with other hormones, have shown considerable promise in clinical trials, and they are currently at the forefront of research and development. However, the long-term effects of using hormones throughout a male’s reproductive life for contraception are unknown, and it may take decades before this information becomes available. Because of this, many investigators are aiming to bring a nonhormonal male contraceptive to the consumer market. Indeed, there are several distinct but feasible avenues in which fertility can be regulated without affecting the hypothalamus-pituitary-testis axis. In this review, we discuss several approaches for fertility control involving the testis that one day may lead to the development of a nonhormonal male contraceptive. PMID:20933122

Clinical assessment of the male fertility

PubMed Central

Khatun, Amena; Rahman, Md Saidur

2018-01-01

The evaluation of infertility in males consists of physical examination and semen analyses. Standardized semen analyses depend on the descriptive analysis of sperm motility, morphology, and concentration, with a threshold level that must be surpassed to be considered a fertile spermatozoon. Nonetheless, these conventional parameters are not satisfactory for clinicians since 25% of infertility cases worldwide remain unexplained. Therefore, newer tests methods have been established to investigate sperm physiology and functions by monitoring characteristics such as motility, capacitation, the acrosome reaction, reactive oxygen species, sperm DNA damage, chromatin structure, zona pellucida binding, and sperm-oocyte fusion. After the introduction of intracytoplasmic sperm injection technique, sperm maturity, morphology, and aneuploidy conditions have gotten more attention for investigating unexplained male infertility. In the present article, recent advancements in research regarding the utilization of male fertility prediction tests and their role and accuracy are reviewed. PMID:29564308

Age-Related Changes in Children's Hedonic Response to Male Body Odor.

ERIC Educational Resources Information Center

Stevenson, Richard J.; Repacholi, Betty M.

2003-01-01

Examined children's and adolescents' ability to identify male sweat and other odors and their rating of odors for liking. Found that only female adolescents could identify and disliked male sweat. When cued about odor identity, both male and female adolescents disliked male sweat more than children. Concluded that dislike for male sweat odor may…

Decoding Ventromedial Hypothalamic Neural Activity during Male Mouse Aggression

PubMed Central

Dollar, Piotr; Perona, Pietro

2014-01-01

The ventromedial hypothalamus, ventrolateral area (VMHvl) was identified recently as a critical locus for inter-male aggression. Optogenetic stimulation of VMHvl in male mice evokes attack toward conspecifics and inactivation of the region inhibits natural aggression, yet very little is known about its underlying neural activity. To understand its role in promoting aggression, we recorded and analyzed neural activity in the VMHvl in response to a wide range of social and nonsocial stimuli. Although response profiles of VMHvl neurons are complex and heterogeneous, we identified a subpopulation of neurons that respond maximally during investigation and attack of male conspecific mice and during investigation of a source of male mouse urine. These “male responsive” neurons in the VMHvl are tuned to both the inter-male distance and the animal's velocity during attack. Additionally, VMHvl activity predicts several parameters of future aggressive action, including the latency and duration of the next attack. Linear regression analysis further demonstrates that aggression-specific parameters, such as distance, movement velocity, and attack latency, can model ongoing VMHvl activity fluctuation during inter-male encounters. These results represent the first effort to understand the hypothalamic neural activity during social behaviors using quantitative tools and suggest an important role for the VMHvl in encoding movement, sensory, and motivation-related signals. PMID:24760856

Anterior cruciate ligament rupture: differences between males and females.

PubMed

Sutton, Karen M; Bullock, James Montgomery

2013-01-01

The rate of anterior cruciate ligament (ACL) rupture is three times higher in female athletes than in male athletes. Intrinsic factors such as increased quadriceps angle and increased posterior tibial slope may predispose girls and women to ACL injury. Compared with males, females have smaller notch widths and smaller ACL cross-sectional area; however, no conclusive correlation between ACL size and notch dimension exists, especially in relation to risk of ACL injury. Female athletes who land with the knees in inadequate flexion and in greater-than-normal valgus and external rotation are at increased risk of ACL injury. No conclusive link has been made between ACL injury and the menstrual cycle. Neuromuscular intervention protocols have been shown to reduce the rate of injury in girls and women. Females are more likely than males to have a narrow A-shaped intercondylar notch, and special surgical considerations are required in such cases. Following ACL reconstruction, female athletes are more likely than male athletes to rupture the contralateral ACL; however, males and females are equally likely to rupture the reconstructed knee. Although self-reported outcomes in the first 2 years following reconstruction are worse for females than for males, longer-term studies demonstrate no difference between males and females.

African American Male Student-Athletes: Identity and Academic Performance

ERIC Educational Resources Information Center

O'Brien, Kathryn Mary

2012-01-01

The purpose of the current research was to examine racial, male and athletic identities and their individual and collective impact on the academic performance of African American male Division I student-athletes (AAMSAs). Data was collected using the Multidimensional Inventory of Black Identity (MIBI), the Male Role Norms Scale (MRNS), and the…

Assessment of environmental factors affecting male fertility

PubMed Central

Dixon, R. L.; Sherins, R. J.; Lee, I. P.

1979-01-01

Exposure to drinking water containing as much as 500 ppm aluminum chloride for periods of 30, 60, and 90 days had no apparent effect on male reproductive processes. In an attempt to correlate enzyme activity with particular spermatogenic cell types, postnatal development of testicular enzymes was studied. Eight enzymes were selected: hyaluronidase (H), lactate dehydrogenase isoenzyme-X (LDH-X), dehydrogenases of sorbitol (SDH), α-glycerophosphate (GPDH), glucose-6-phosphate (G6PDH), malate (MDH), glyceraldehyde-3-phosphate (G3PDH), and isocitrate (ICDH). Enzyme specific activities in testicular homogenates were determined. Two types of enzyme developmental patterns were observed. One was represented by H, LDH-X, SDH, and GPDH; and the other by G6PDH, MDH, G3PDH, and ICDH. The former was characterized by a change in enzyme activities from low in newborn to high in adult while in the latter this pattern was reversed. The two complementary enzyme systems crossed each other at puberty. Prior to puberty, only spermatogonial cells are present; sperm differentiation initiated at puberty adds spermatocytes and spermatids to the testicular cell population. Male rats were exposed to borax in their diet for periods of 30 and 60 days. Concentrations of boron were 0, 500, 1000, and 2000 ppm. At the end of each experimental period, the specific activities of the selected enzymes were determined in the testis and prostate. Correlations of enzyme activity with testicular histology and androgen activities of the male accessory organs were sought. In addition, plasma FSH, LH, and testosterone levels were measured to assess pituitary-testicular interaction. Plasma and testicular boron concentrations were determined and a minimum boron concentration which induced germinal aplasia and male infertility was estimated. In both 30 and 60 day feeding studies, male rats receiving 500 ppm failed to demonstrate any significant adverse effects. In contrast, male rats receiving 100 and 2000 ppm

Alternative phenotypes of male mating behaviour in the two-spotted spider mite.

PubMed

Sato, Yukie; Sabelis, Maurice W; Egas, Martijn; Faraji, Farid

2013-09-01

Severe intraspecific competition for mates selects for aggressive individuals but may also lead to the evolution of alternative phenotypes that do not act aggressively, yet manage to acquire matings. The two-spotted spider mite, Tetranychus urticae, shows male mate-guarding behaviour and male-male combat for available females. This may provide opportunity for weaker males to avoid fighting by adopting alternative mating behaviour such as sneaker or satellite tactics as observed in other animals. We investigated male precopulatory behaviour in the two-spotted spider mite by means of video-techniques and found three types of male mating behaviour: territorial, sneaker and opportunistic. Territorial and sneaker males associate with female teleiochrysales and spend much time guarding them. Territorial males are easily disturbed by rival males and engage themselves in fights with them. However, sneaker males are not at all disturbed by rival males, never engage in fights and, strikingly, never face attack by territorial males. Opportunistic males wander around in search of females that are in the teleiochrysalis stage but very close to or at emergence. To quickly classify any given mate-guarding male as territorial or sneaker we developed a method based on the instantaneous response of males to disturbance by a live male mounted on top of a brush. We tested this method against the response of the same males to natural disturbance by two or three other males. Because this method proved to be successful, we used it to collect territorial and sneaker males, and subjected them to morphological analysis to assess whether the various behavioural phenotypes are associated with different morphological characters. However, we found no statistical differences between territorial and sneaker males, concerning the length of the first legs, the stylets, the pedipalps or the body.

Final height in elite male artistic gymnasts.

PubMed

Georgopoulos, Neoklis A; Theodoropoulou, Anastasia; Roupas, Nikolaos D; Armeni, Anastasia K; Koukkou, Eftychia; Leglise, Michel; Markou, Kostas B

2012-01-01

Elite male artistic gymnasts (AG) are exposed to high levels of physical and psychological stress during adolescence and experience a significant late maturation in both linear growth and pubertal development. The aim of the present study was to determine the impact of intensive physical training on the adult final height in elite male AG. This study is unique in character, as all variables were measured on the field of competition. The study was prospective and longitudinal; however, the current analysis of data is cross-sectional. Data from 86 elite male AG were obtained during the gymnastics competitions of European and World Championships. Clinical evaluation included height and weight measurements, as well as assessment of pubic hair and genital development according to Tanner's stages of pubertal development. The laboratory investigation included determination of skeletal maturation. All athletes completed a questionnaire that included questions on personal (onset and intensity of training, number of competitions per year) and family data (paternal and maternal heights). Male AG were below the 50th percentile for both final height and weight. Elite male AG had final height standard deviation score (SDS) lower than their genetic predisposition. Final height SDS was correlated positively with target height SDS (r = 0.430, p < 0.001) and weight SDS (r = 0.477, p < 0.001) and negatively to the intensity of training (r = -0.252, p = 0.022). The main factors influencing final height, by multiple regression analysis were weight SDS (p < 0.001) and target height SDS (p = 0.003). In elite maleAG, final height falls short of genetic predisposition, still well within normal limits. Considering medical and psychological risks in general, and based on the results of this research project, the International Federation of Gymnastics has increased the age limit for participants in international gymnastics competitions by 1 year.

Safety of a new compact male intermittent catheter: randomized, cross-over, single-blind study in healthy male volunteers.

PubMed

Bagi, Per; Hannibalsen, Jane; Permild, Rikke; Stilling, Sine; Looms, Dagnia K

2011-01-01

A new compact male intermittent catheter was compared with a regular intermittent male catheter in terms of safety and acceptability. In this randomized, single-blind, cross-over study, healthy male volunteers were catheterized twice with a compact catheter and twice with a regular catheter. 28 participants were enrolled. Mean ± SD discomfort (visual analogue scale; primary objective) was 2.25 ± 1.5 and 2.52 ± 1.8 for the compact and regular catheters, respectively (difference -0.27; 95% confidence interval -0.73 to 0.19); there was no significant difference in hematuria (p = 0.54) or discomfort/stinging/pain at first micturition (p = 0.56). During insertion, handling was easier (p = 0.0001) and touching the coating was necessary less often (2.2 vs. 81.3% of catheterizations; p < 0.0001) with the compact catheter; it was preferred by nurses for 20 of 23 participants. No adverse events were reported. Short-term safety of the new compact catheter was at least as good as that of the regular male intermittent catheter and handling was improved. Copyright © 2011 S. Karger AG, Basel.

The Sexual Stereotype of the Black Male.

ERIC Educational Resources Information Center

Davis, Gary L.; Cross, Herbert J.