Coy Males and Seductive Females in the Sexually Cannibalistic Colonial Spider, Cyrtophora citricola

PubMed Central

Yip, Eric C.; Berner-Aharon, Na’ama; Smith, Deborah R.; Lubin, Yael

2016-01-01

The abundance of sperm relative to eggs selects for males that maximize their number of mates and for females that choose high quality males. However, in many species, males exercise mate choice, even when they invest little in their offspring. Sexual cannibalism may promote male choosiness by limiting the number of females a male can inseminate and by biasing the sex ratio toward females because, while females can reenter the mating pool, cannibalized males cannot. These effects may be insufficient for male choosiness to evolve, however, if males face low sequential encounter rates with females. We hypothesized that sexual cannibalism should facilitate the evolution of male choosiness in group living species because a male is likely to encounter multiple receptive females simultaneously. We tested this hypothesis in a colonial orb-weaving spider, Cyrtophora citricola, with a high rate of sexual cannibalism. We tested whether mated females would mate with multiple males, and thereby shift the operational sex ratio toward females. We also investigated whether either sex chooses mates based on nutritional state and age, and whether males choose females based on reproductive state. We found that females are readily polyandrous and exhibit no mate choice related to male feeding or age. Males courted more often when the male was older and the female was younger, and males copulated more often with well-fed females. The data show that males are choosier than females for the traits we measured, supporting our hypothesis that group living and sexual cannibalism may together promote the evolution of male mate choice. PMID:27249787

Coy Males and Seductive Females in the Sexually Cannibalistic Colonial Spider, Cyrtophora citricola.

PubMed

Yip, Eric C; Berner-Aharon, Na'ama; Smith, Deborah R; Lubin, Yael

2016-01-01

The abundance of sperm relative to eggs selects for males that maximize their number of mates and for females that choose high quality males. However, in many species, males exercise mate choice, even when they invest little in their offspring. Sexual cannibalism may promote male choosiness by limiting the number of females a male can inseminate and by biasing the sex ratio toward females because, while females can reenter the mating pool, cannibalized males cannot. These effects may be insufficient for male choosiness to evolve, however, if males face low sequential encounter rates with females. We hypothesized that sexual cannibalism should facilitate the evolution of male choosiness in group living species because a male is likely to encounter multiple receptive females simultaneously. We tested this hypothesis in a colonial orb-weaving spider, Cyrtophora citricola, with a high rate of sexual cannibalism. We tested whether mated females would mate with multiple males, and thereby shift the operational sex ratio toward females. We also investigated whether either sex chooses mates based on nutritional state and age, and whether males choose females based on reproductive state. We found that females are readily polyandrous and exhibit no mate choice related to male feeding or age. Males courted more often when the male was older and the female was younger, and males copulated more often with well-fed females. The data show that males are choosier than females for the traits we measured, supporting our hypothesis that group living and sexual cannibalism may together promote the evolution of male mate choice.

Choosy Moral Punishers

PubMed Central

Clavien, Christine; Tanner, Colby J.; Clément, Fabrice; Chapuisat, Michel

2012-01-01

The punishment of social misconduct is a powerful mechanism for stabilizing high levels of cooperation among unrelated individuals. It is regularly assumed that humans have a universal disposition to punish social norm violators, which is sometimes labelled “universal structure of human morality” or “pure aversion to social betrayal”. Here we present evidence that, contrary to this hypothesis, the propensity to punish a moral norm violator varies among participants with different career trajectories. In anonymous real-life conditions, future teachers punished a talented but immoral young violinist: they voted against her in an important music competition when they had been informed of her previous blatant misconduct toward fellow violin students. In contrast, future police officers and high school students did not punish. This variation among socio-professional categories indicates that the punishment of norm violators is not entirely explained by an aversion to social betrayal. We suggest that context specificity plays an important role in normative behaviour; people seem inclined to enforce social norms only in situations that are familiar, relevant for their social category, and possibly strategically advantageous. PMID:22720012

Evolution of male and female choice in polyandrous systems.

PubMed

Puurtinen, Mikael; Fromhage, Lutz

2017-03-29

We study the evolution of male and female mating strategies and mate choice for female fecundity and male fertilization ability in a system where both sexes can mate with multiple partners, and where there is variation in individual quality (i.e. in the availability of resources individuals can allocate to matings, mate choice and production of gametes). We find that when the cost of mating differs between sexes, the sex with higher cost of mating is reluctant to accept matings and is often also choosy, while the other sex accepts all matings. With equal mating costs, the evolution of mating strategies depends on the strength of female sperm limitation, so that when sperm limitation is strong, males are often reluctant and choosy, whereas females tend to accept available matings. Male reluctance evolves because a male's benefit per mating diminishes rapidly as he mates too often, hence losing out in the process of sperm competition as he spends much of his resources on mating costs rather than ejaculate production. When sperm limitation is weaker, females become more reluctant and males are more eager to mate. The model thus suggests that reversed sex roles are plausible outcomes of polyandry and limited sperm production. Implications for empirical studies of mate choice are discussed. © 2017 The Author(s).

Hemiclonal analysis of interacting phenotypes in male and female Drosophila melanogaster

PubMed Central

2014-01-01

Background Identifying the sources of variation in mating interactions between males and females is important because this variation influences the strength and/or the direction of sexual selection that populations experience. While the origins and effects of variation in male attractiveness and ornamentation have received much scrutiny, the causes and consequences of intraspecific variation in females have been relatively overlooked. We used cytogenetic cloning techniques developed for Drosophila melanogaster to create “hemiclonal” males and females with whom we directly observed sexual interaction between individuals of different known genetic backgrounds and measured subsequent reproductive outcomes. Using this approach, we were able to quantify the genetic contribution of each mate to the observed phenotypic variation in biologically important traits including mating speed, copulation duration, and subsequent offspring production, as well as measure the magnitude and direction of intersexual genetic correlation between female choosiness and male attractiveness. Results We found significant additive genetic variation contributing to mating speed that can be attributed to male genetic identity, female genetic identity, but not their interaction. Furthermore we found that phenotypic variation in copulation duration had a significant male-associated genetic component. Female genetic identity and the interaction between male and female genetic identity accounted for a substantial amount of the observed phenotypic variation in egg size. Although previous research predicts a trade-off between egg size and fecundity, this was not evident in our results. We found a strong negative genetic correlation between female choosiness and male attractiveness, a result that suggests a potentially important role for sexually antagonistic alleles in sexual selection processes in our population. Conclusion These results further our understanding of sexual selection because they

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.

Job shop fails choosy nurses.

PubMed

1993-10-13

Only 181 people have used the Clearing House set up to find jobs for redundant London nurses. And almost a quarter have rejected the posts which it says are suitable for them, with 21 per cent of employers turning down candidates selected by the initiative.

Terminal Investment Strategies and Male Mate choice: Extreme Tests of Bateman.

PubMed

Andrade, Maydianne C B; Kasumovic, Michael M

2005-11-01

Bateman's principle predicts the intensity of sexual selection depends on rates of increase of fecundity with mating success for each sex (Bateman slopes). The sex with the steeper increase (usually males) is under more intense sexual selection and is expected to compete for access to the sex under less intense sexual selection (usually females). Under Bateman and modern refinements of his ideas, differences in parental investment are key to defining Bateman slopes and thus sex roles. Other theories predict sex differences in mating investment, or any expenditures that reduce male potential reproductive rate, can also control sex roles. We focus on sexual behaviour in systems where males have low paternal investment but frequently mate only once in their lifetimes, after which they are often killed by the female. Mating effort (=terminal investment) is high for these males, and many forms of investment theory might predict sex role reversal. We find no qualitative evidence for sex role reversal in a sample of spiders that show this extreme male investment pattern. We also present new data for terminally-investing redback spiders (Latrodectus hasselti). Bateman slopes are relatively steep for male redbacks, and, as predicted by Bateman, there is little evidence for role reversal. Instead, males are competitive and show limited choosiness despite wide variation in female reproductive value. This study supports the proposal that high male mating investment coupled with low parental investment may predispose males to choosiness but will not lead to role reversal. We support the utility of using Bateman slopes to predict sex roles, even in systems with extreme male mating investment.

Males choose to keep their heads: Preference for lower risk females in a praying mantid.

PubMed

Avigliano, Esteban; Scardamaglia, Romina C; Gabelli, Fabián M; Pompilio, Lorena

2016-08-01

Male reproductive success is obviously mate limited, which implies that males should rarely be choosy. One extreme case of a reproductive (or mating) cost is sexual cannibalism. Recent research has proposed that male mantids (Parastagmatoptera tessellata) are choosy and not complicit in cannibalism and that they modify behavior towards females based on the risk imposed by them. Since female cannibalism depends on females' energetic state (i.e. hunger) we investigated whether male mantids are capable of using environmental cues that provide information regarding the energetic state of females to make their mate choices. Under laboratory conditions, males were confronted individually with three options: a female eating a prey, a female without a prey, and a male eating a prey (as a control for the presence of prey). Each subject comprising a choice was harnessed and placed in the corners of a triangular experimental arena at an equidistant distance from the focal male. The prey was a middle size cricket that subjects ate in approximately twenty minutes. The behavior of focal males was recorded for six hours. Females were under the same deprivation regime and, in line with previous studies, consuming one cricket did not significantly increase females' abdomen girth. Male mantids significantly preferred females that were eating a prey. In all cases choices were made after the females consumed the whole prey. This suggests that males did not use the prey as a direct way to avoid being cannibalized by keeping the female busy. The preference for females that had recently fed may have evolved because of the potential reduction in sexual cannibalism. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification and molecular profiling of DC-SIGN-like from big belly seahorse (Hippocampus abdominalis) inferring its potential relevancy in host immunity.

PubMed

Jo, Eunyoung; Elvitigala, Don Anushka Sandaruwan; Wan, Qiang; Oh, Minyoung; Oh, Chulhong; Lee, Jehee

2017-12-01

Dendritic-cell-specific ICAM-3-grabbing non-integrin (DC-SIGN) is a C-type lectin that functions as a pattern recognition receptor by recognizing pathogen-associated molecular patterns (PAMPs). It is also involved in various events of the dendritic cell (DC) life cycle, such as DC migration, antigen capture and presentation, and T cell priming. In this study, a DC-SIGN-like gene from the big belly seahorse Hippocampus abdominalis (designated as ShDCS-like) was identified and molecularly characterized. The putative, complete ORF was found to be 1368 bp in length, encoding a protein of 462 amino acids with a molecular mass of 52.6 kDa and a theoretical isoelectric point of 8.26. The deduced amino acid sequence contains a single carbohydrate recognition domain (CRD), in which six conserved cysteine residues and two Ca 2+ -binding site motifs (QPN, WND) were identified. Based on pairwise sequence analysis, ShDCS-like exhibits the highest amino acid identity (94.6%) and similarity (97.4%) with DC-SIGN-like counterpart from tiger tail seahorse Hippocampus comes. Quantitative real-time PCR revealed that ShDCS-like mRNA is transcribed universally in all tissues examined, but with abundance in kidney and gill tissues. The basal mRNA expression of ShDCS-like was modulated in blood cell, kidney, gill and liver tissues in response to the stimulation of healthy fish with lipopolysaccharides (LPS), Edwardsiella tarda, or Streptococcus iniae. Moreover, recombinant ShDCS-like-CRD domain exhibited detectable agglutination activity against different bacteria. Collectively, these results suggest that ShDCS-like may potentially involve in immune function in big belly seahorses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of a 1-cysteine peroxiredoxin from big-belly seahorse (Hippocampus abdominalis); insights into host antioxidant defense, molecular profiling and its expressional response to septic conditions.

PubMed

Godahewa, G I; Perera, N C N; Elvitigala, Don Anushka Sandaruwan; Jayasooriya, R G P T; Kim, Gi-Young; Lee, Jehee

2016-10-01

1-cysteine peroxiredoxin (Prx6) is an antioxidant enzyme that protects cells by detoxifying multiple peroxide species. This study aimed to describe molecular features, functional assessments and potential immune responses of Prx6 identified from the big-belly seahorse, Hippocampus abdominalis (HaPrx6). The complete ORF (666 bp) of HaPrx6 encodes a polypeptide (24 kDa) of 222 amino acids, and harbors a prominent peroxiredoxin super-family domain, a peroxidatic catalytic center, and a peroxidatic cysteine. The deduced amino acid sequence of HaPrx6 shares a relatively high amino acid sequence similarity and close evolutionary relationship with Oplegnathus fasciatus Prx6. The purified recombinant HaPrx6 protein (rHaPrx6) was shown to protect plasmid DNA in the Metal Catalyzed Oxidation (MCO) assay and, together with 1,4-Dithiothreitol (DTT), protected human leukemia THP-1 cells from extracellular H2O2-mediated cell death. In addition, quantitative real-time PCR revealed that HaPrx6 mRNA was constitutively expressed in 14 different tissues, with the highest expression observed in liver tissue. Inductive transcriptional responses were observed in liver and kidney tissues of fish after treating them with bacterial stimuli, including LPS, Edwardsiella tarda, and Streptococcus iniae. These results suggest that HaPrx6 may play an important role in the immune response of the big-belly seahorse against microbial infection. Collectively, these findings provide structural and functional insights into HaPrx6. Copyright © 2016 Elsevier Ltd. All rights reserved.

Manganese-superoxide dismutase (MnSOD), a role player in seahorse (Hippocampus abdominalis) antioxidant defense system and adaptive immune system.

PubMed

Perera, N C N; Godahewa, G I; Lee, Seongdo; Kim, Myoung-Jin; Hwang, Jee Youn; Kwon, Mun Gyeong; Hwang, Seong Don; Lee, Jehee

2017-09-01

Manganese superoxide dismutase (MnSOD) is a metaloenzyme that catalyzes dismutation of the hazardous superoxide radicals into less hazardous H 2 O 2 and H 2 O. Here, we identified a homolog of MnSOD from big belly seahorse (Hippocampus abdominalis; HaMnSOD) and characterized its structural and functional features. HaMnSOD transcript possessed an open reading frame (ORF) of 672 bp which codes for a peptide of 223 amino acids. Pairwise alignment showed that HaMnSOD shared highest identity with rock bream MnSOD. Results of the phylogenetic analysis of HaMnSOD revealed a close proximity with rock bream MnSOD which was consistent with the result of homology alignment. The intense expression of HaMnSOD was observed in the ovary, followed by the heart and the brain. Further, immune related responses of HaMnSOD towards pathogenic stimulation were observed through bacterial and viral challenges. Highest HaMnSOD expression in response to stimulants Edwardsiella tarda, Streptococcus iniae, lipopolysaccharide (LPS), and polyinosinic-polycytidylic acid (Poly I:C) was observed in the late stage in the blood tissue. Xanthine/xanthine oxidase assay (XOD assay) indicated the ROS-scavenging ability of purified recombinant HaMnSOD (rHaMnSOD). The optimum conditions for the SOD activity of rHaMnSOD were pH 9 and the 25 °C. Collectively, the results obtained through the expressional analysis profiles and the functional assays provide insights into potential immune related and antioxidant roles of HaMnSOD in the big belly seahorse. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular cloning, biochemical characterization, and expression analysis of two glutathione S-transferase paralogs from the big-belly seahorse (Hippocampus abdominalis).

PubMed

Tharuka, M D Neranjan; Bathige, S D N K; Lee, Jehee

2017-12-01

Glutathione S-transferases (GSTs, EC 2.5.1.18) are important Phase II detoxifying enzymes that catalyze hydrophobic, electrophilic xenobiotic substance with the conjugation of reduced glutathione (GSH). In this study, GSTμ and GSTρ paralogs of GST in the big belly seahorse (Hippocampus abdominalis; HaGSTρ, HaGSTμ) were biochemically, molecularly, functionally characterized to determine their detoxification range and protective capacities upon different pathogenic stresses. HaGSTρ and HaGSTμ are composed of coding sequences of 681bp and 654bp, which encode proteins 225 and 217 amino acids, with predicted molecular masses of 26.06kDa and 25.74kDa respectively. Sequence analysis revealed that both HaGSTs comprise the characteristic GSH-binding site in the thioredoxin-like N-terminal domain and substrate binding site in the C-terminal domain. The recombinant HaGSTρ and HaGSTμ proteins catalyzed the model GST substrate 1-chloro-2, 4-dinitrobenzene (CDNB). Enzyme kinetic analysis revealed different K m and V max values for each rHaGST, suggesting that they have different conjugation rates. The optimum conditions (pH, temperature) and inhibitory assays of each protein demonstrated different optimal ranges. However, HaGSTμ was highly expressed in the ovary and gill, whereas HaGSTρ was highly expressed in the gill and pouch. mRNA expression of HaGSTρ and HaGSTμ was significantly elevated upon lipopolysaccharide, Poly (I:C), and Edwardsiella tarda challenges in liver and in blood cells as well as with Streptococcus iniae challenge in blood cells. From these collective experimental results, we propose that HaGSTρ and HaGSTμ are effective in detoxifying xenobiotic toxic agents, and importantly, their mRNA expression could be stimulated by immunological stress signals in the aquatic environment. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

Genotype-by-Environment Interactions for Female Mate Choice of Male Cuticular Hydrocarbons in Drosophila simulans

PubMed Central

Ingleby, Fiona C.; Hunt, John; Hosken, David J.

2013-01-01

Recent research has highlighted the potential importance of environmental and genotype-by-environment (G×E) variation in sexual selection, but most studies have focussed on the expression of male sexual traits. Consequently, our understanding of genetic variation for plasticity in female mate choice is extremely poor. In this study we examine the genetics of female mate choice in Drosophila simulans using isolines reared across two post-eclosion temperatures. There was evidence for G×Es in female choosiness and preference, which suggests that the evolution of female mate choice behaviour could differ across environments. However, the ranked order of preferred males was consistent across females and environments, so the same males are favoured by mate choice in spite of G×Es. Our study highlights the importance of taking cross-environment perspectives in order to gain a more comprehensive understanding of the operation of sexual selection. PMID:23825675

Pedicled rectus abdominis muscle and fascia flap sling the bulbar urethra for treatment for male-acquired urinary incontinence: report of ten cases.

PubMed

Xu, Yue-Min; Zhang, Xin-Ru; Xie, Hong; Song, Lu-Jie; Feng, Chao; Fei, Xiao-Fang

2014-03-01

Male urinary incontinence is relatively common complication of radical prostatectomy and of posterior urethroplasty following traumatic pelvic fracture. Here, we investigate the use of pedicled rectus abdominis muscle and fascia flap sling of the bulbar urethra for treatment for male-acquired urinary incontinence. Ten patients with acquired urinary incontinence were included in the study. Urinary incontinence was secondary to TURP in three patients and was secondary to posterior urethroplasty performed following traumatic pelvic fracture in seven patients. Pedicled rectus abdominalis muscle and fascial flaps, approximately 2.5 cm wide and 15 cm long, were isolated. The flaps were inserted into a perineal incision through a subcutaneous tunnel. The free end of the flap was sectioned to form two muscle strips, each 3 cm in length, and inserted into the space between bulbar urethra and corpus cavernosa. After adequate sling tension had been achieved, the two strips of muscle were anastomosed around the bulbar urethra using a 2-zero polyglactin suture. The patients were followed up for between 12 and 82 months (mean 42.8 months). Complete continence was achieved with good voiding in seven of the 10 patients. In other three patients achieved good voiding following catheter removal, but incontinence was only moderately improved. A pedicled rectus muscle fascial sling of the bulbar urethra is an effective and safe treatment for male patients with mild to moderate acquired urinary incontinence, but it may not be suitable for severe incontinence or for patients with weak rectus abdominalis muscles.

Sexual selection for male dominance reduces opportunities for female mate choice in the European bitterling (Rhodeus sericeus).

PubMed

Reichard, M; Bryja, J; Ondracková, M; Dávidová, M; Kaniewska, P; Smith, C

2005-04-01

Sexual selection involves two main mechanisms: intrasexual competition for mates and intersexual mate choice. We experimentally separated intrasexual (male-male interference competition) and intersexual (female choice) components of sexual selection in a freshwater fish, the European bitterling (Rhodeus sericeus). We compared the roles of multiple morphological and behavioural traits in male success in both components of sexual competition, and their relation to male reproductive success, measured as paternity of offspring. Body size was important for both female choice and male-male competition, though females also preferred males that courted more vigorously. However, dominant males often monopolized females regardless of female preference. Subordinate males were not excluded from reproduction and sired some offspring, possibly through sneaked ejaculations. Male dominance and a greater intensity of carotenoid-based red colouration in their iris were the best predictors of male reproductive success. The extent of red iris colouration and parasite load did not have significant effects on female choice, male dominance or male reproductive success. No effect of parasite load on the expression of red eye colouration was detected, though this may have been due to low parasite prevalence in males overall. In conclusion, we showed that even though larger body size was favoured in both intersexual and intrasexual selection, male-male interference competition reduced opportunities for female choice. Females, despite being choosy, had limited control over the paternity of their offspring. Our study highlights the need for reliable measures of male reproductive success in studies of sexual selection.

Diseases of captive yellow seahorse Hippocampus kuda Bleeker, pot-bellied seahorse Hippocampus abdominalis Lesson and weedy seadragon Phyllopteryx taeniolatus (Lacépède).

PubMed

LePage, V; Young, J; Dutton, C J; Crawshaw, G; Paré, J A; Kummrow, M; McLelland, D J; Huber, P; Young, K; Russell, S; Al-Hussinee, L; Lumsden, J S

2015-05-01

Seahorses, pipefish and seadragons are fish of the Family Syngnathidae. From 1998 to 2010, 172 syngnathid cases from the Toronto Zoo were submitted for post-mortem diagnostics and retrospectively examined. Among the submitted species were yellow seahorses Hippocampus kuda Bleeker (n=133), pot-bellied seahorses Hippocampus abdominalis Lesson (n=35) and weedy seadragons Phyllopteryx taeniolatus (Lacépède; n=4). The three most common causes of morbidity and mortality in this population were bacterial dermatitis, bilaterally symmetrical myopathy and mycobacteriosis, accounting for 24%, 17% and 15% of cases, respectively. Inflammatory processes were the most common diagnoses, present in 117 cases. Seven neoplasms were diagnosed, environmental aetiologies were identified in 46 cases, and two congenital defects were identified. © 2014 John Wiley & Sons Ltd.

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

PubMed

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

2014-10-01

The phenotype of male Hymenoptera and the peculiar role of males has been neglected and greatly understudied, given the spectacular cooperative behavior of female social insects. In social insects there has been considerable progress in understanding the molecular mechanisms behind haplodiploid sex determination but, beyond that, very little is known concerning the neural, endocrine, and genetic correlates of sexual selection in males. An opportunity is being missed: the male phenotype in Hymenoptera is a natural experiment to compare the drives of natural versus sexual selection. In contrast to females, males do not work, they usually display far from the nest to gain mates, compete among rivals in nuptial flights or for a symbolic territory at leks, and engage in direct or ritualized conflicts. By comparing the available data on male paper wasps with studies on other social Hymenoptera, we summarize what we currently know about the physical, hormonal, neural and behavioral traits in a model system appropriate to examine current paradigms on sexual selection. Here we review male behavior in social Hymenoptera beyond sex stereotypes: the subtle role of "drones" in the colony, the lack of armaments and ornaments, the explosive mating crowds, the "endurance" race, the cognitive bases of the "choosy" male and his immune defense. Social insect males are not just simple-minded mating machines, they are shaped, constrained and perhaps trapped by sexual selection. Copyright © 2014 Elsevier Ltd. All rights reserved.

Males of a Strongly Polygynous Species Consume More Poisonous Food than Females

PubMed Central

Bravo, Carolina; Bautista, Luis Miguel; García-París, Mario; Blanco, Guillermo; Alonso, Juan Carlos

2014-01-01

We present evidence of a possible case of self-medication in a lekking bird, the great bustard Otis tarda. Great bustards consumed blister beetles (Meloidae), in spite of the fact that they contain cantharidin, a highly toxic compound that is lethal in moderate doses. In addition to anthelminthic properties, cantharidin was effective against gastrointestinal bacteria that cause sexually-transmitted diseases. Although both sexes consumed blister beetles during the mating season, only males selected them among all available insects, and ingested more and larger beetles than females. The male-biased consumption suggests that males could use cantharidin to reduce their parasite load and increase their sexual attractiveness. This plausibly explains the intense cloaca display males perform to approaching females, and the meticulous inspection females conduct of the male's cloaca, a behaviour only observed in this and another similar species of the bustard family. A white, clean cloaca with no infection symptoms (e.g., diarrhoea) is an honest signal of both, resistance to cantharidin and absence of parasites, and represents a reliable indicator of the male quality to the extremely choosy females. Our results do not definitely prove, but certainly strongly suggest that cantharidin, obtained by consumption of blister beetles, acts in great bustards as an oral anti-microbial and pathogen-limiting compound, and that males ingest these poisonous insects to increase their mating success, pointing out that self-medication might have been overlooked as a sexually-selected mechanism enhancing male fitness. PMID:25337911

On the role of individual differences in female odor and ultrasonic vocalizations for male's choice of partner.

PubMed

Snoeren, Eelke M; Helander, Lars R; Iversen, Eric E; Ågmo, Anders

2014-06-10

Intrasexual competition for access to a female mate is believed to be unusual in wild male rats, which suggests that female choosiness could be important. Even if competition is unusual, males still have to inevitably approach one partner first for copulation. In females, it has been shown that females spend longer time with one male compared to the others when tested in a multiple partner paradigm. The male mate preference was investigated in this study. In addition, the role of ultrasonic vocalizations (USVs) and female odors in the male's initial choice to approach one female instead of another was studied in this experiment. Male rats could choose between three different sexually receptive females. The experiment started with a 15-minute period with inaccessible females followed by a 15-minute period with accessible females in which the males could copulate with the females of his choice. The results showed that male rats spent more time with the female of 1st entry over the second or third females visited. No differences were found in USV subtype patterns emitted by the different females or the number of sniff episodes towards the different female chambers. Thus, the present experiments did not offer any evidence suggesting that USVs or individual differences in female odors play any role in male mate choice. Other factors that were not investigated in this study might be involved in male mate selection, but it should also be considered that mate selection could be random. Copyright © 2014 Elsevier Inc. All rights reserved.

Personality differentially affects individual mate choice decisions in female and male Western mosquitofish (Gambusia affinis).

PubMed

Chen, Bo-Jian; Liu, Kai; Zhou, Lin-Jun; Gomes-Silva, Guilherme; Sommer-Trembo, Carolin; Plath, Martin

2018-01-01

Consistent individual differences in behavioral tendencies (animal personality) can affect individual mate choice decisions. We asked whether personality traits affect male and female mate choice decisions similarly and whether potential personality effects are consistent across different mate choice situations. Using western mosquitofish (Gambusia affinis) as our study organism, we characterized focal individuals (males and females) twice for boldness, activity, and sociability/shoaling and found high and significant behavioral repeatability. Additionally, each focal individual was tested in two different dichotomous mate choice tests in which it could choose between computer-animated stimulus fish of the opposite sex that differed in body size and activity levels, respectively. Personality had different effects on female and male mate choice: females that were larger than average showed stronger preferences for large-bodied males with increasing levels of boldness/activity (i.e., towards more proactive personality types). Males that were larger than average and had higher shoaling tendencies showed stronger preferences for actively swimming females. Size-dependent effects of personality on the strength of preferences for distinct phenotypes of potential mating partners may reflect effects of age/experience (especially in females) and social dominance (especially in males). Previous studies found evidence for assortative mate choice based on personality types or hypothesized the existence of behavioral syndromes of individuals' choosiness across mate choice criteria, possibly including other personality traits. Our present study exemplifies that far more complex patterns of personality-dependent mate choice can emerge in natural systems.

First comparative characterization of three distinct ferritin subunits from a teleost: Evidence for immune-responsive mRNA expression and iron depriving activity of seahorse (Hippocampus abdominalis) ferritins.

PubMed

Oh, Minyoung; Umasuthan, Navaneethaiyer; Elvitigala, Don Anushka Sandaruwan; Wan, Qiang; Jo, Eunyoung; Ko, Jiyeon; Noh, Gyeong Eon; Shin, Sangok; Rho, Sum; Lee, Jehee

2016-02-01

Ferritins play an indispensable role in iron homeostasis through their iron-withholding function in living beings. In the current study, cDNA sequences of three distinct ferritin subunits, including a ferritin H, a ferritin M, and a ferritin L, were identified from big belly seahorse, Hippocampus abdominalis, and molecularly characterized. Complete coding sequences (CDS) of seahorse ferritin H (HaFerH), ferritin M (HaFerM), and ferritin L (HaFerL) subunits were comprised of 531, 528, and 522 base pairs (bp), respectively, which encode polypeptides of 177, 176, and 174 amino acids, respectively, with molecular masses of ∼20-21 kDa. Our in silico analyses demonstrate that these three ferritin subunits exhibit the typical characteristics of ferritin superfamily members including iron regulatory elements, domain signatures, and reactive centers. The coding sequences of HaFerH, M, and L were cloned and the corresponding proteins were overexpressed in a bacterial system. Recombinantly expressed HaFer proteins demonstrated detectable in vivo iron sequestrating (ferroxidase) activity, consistent with their putative iron binding capability. Quantification of the basal expression of these three HaFer sequences in selected tissues demonstrated a gene-specific ubiquitous spatial distribution pattern, with abundance of mRNA in HaFerM in the liver and predominant expression of HaFerH and HaFerL in blood. Interestingly, the basal expression of all three ferritin genes was found to be significantly modulated against pathogenic stress mounted by lipopolysaccharides (LPS), poly I:C, Streptococcus iniae, and Edwardsiella tarda. Collectively, our findings suggest that the three HaFer subunits may be involved in iron (II) homeostasis in big belly seahorse and that they are important in its host defense mechanisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Insights into the multifunctional role of natural killer enhancing factor-A (NKEF-A/Prx1) in big-belly seahorse (Hippocampus abdominalis): DNA protection, insulin reduction, H2O2 scavenging, and immune modulation activity.

PubMed

Godahewa, G I; Perera, N C N; Lee, Jehee

2018-02-05

Natural killer enhancing factor A (NKEF-A), also known as peroxiredoxin 1 (Prx1), is a well-known antioxidant involved in innate immunity. Although NKEF-A/Prx1 has been studied in different fish species, the present study broadens the knowledge of NKEF-A gene in terms of molecular structure, function, and immune responses in fish species. Hippocampus abdominalis NKEF-A (HaNKEF-A) cDNA encoded a putative protein of 198 amino acids containing a thioredoxin_2 domain, VCP motifs, and three conserved cysteine residues including peroxidatic and resolving cysteines. Amino acid sequence comparison and phylogenetic breakdown showed the higher sequence identity and closer evolutionary position of HaNKEF-A to those of other fish counterparts. A recombinant protein of HaNKEF-A was shown to i) protect supercoiled DNA against mixed catalyzed oxidation, ii) reduce insulin disulfide bonds, and iii) scavenge extracellular H 2 O 2 . Results of in vitro assays demonstrated the concentration dependent antioxidant function of recombinant HaNKEF-A. In addition, qPCR assessments revealed that the HaNKEF-A transcripts were constitutively expressed in fourteen tissues with the highest expression in liver. As an innate immune response, HaNKEF-A transcripts were up-regulated in liver post injection of LPS, Edwardsiella tarda, Streptococcus iniae, and polyinosinic-polycytidylic acid. Thus, HaNKEF-A can safeguards big-belly seahorse from oxidative damage and pathogenic infections. This study provides insight into the functions of NKEF-A/Prx1 in fish species. Copyright © 2017 Elsevier B.V. All rights reserved.

Low reproductive skew despite high male-biased operational sex ratio in a glass frog with paternal care.

PubMed

Mangold, Alexandra; Trenkwalder, Katharina; Ringler, Max; Hödl, Walter; Ringler, Eva

2015-09-03

Reproductive skew, the uneven distribution of reproductive success among individuals, is a common feature of many animal populations. Several scenarios have been proposed to favour either high or low levels of reproductive skew. Particularly a male-biased operational sex ratio and the asynchronous arrival of females is expected to cause high variation in reproductive success among males. Recently it has been suggested that the type of benefits provided by males (fixed vs. dilutable) could also strongly impact individual mating patterns, and thereby affecting reproductive skew. We tested this hypothesis in Hyalinobatrachium valerioi, a Neotropical glass frog with prolonged breeding and paternal care. We monitored and genetically sampled a natural population in southwestern Costa Rica during the breeding season in 2012 and performed parentage analysis of adult frogs and tadpoles to investigate individual mating frequencies, possible mating preferences, and estimate reproductive skew in males and females. We identified a polygamous mating system, where high proportions of males (69 %) and females (94 %) reproduced successfully. The variance in male mating success could largely be attributed to differences in time spent calling at the reproductive site, but not to body size or relatedness. Female H. valerioi were not choosy and mated indiscriminately with available males. Our findings support the hypothesis that dilutable male benefits - such as parental care - can favour female polyandry and maintain low levels of reproductive skew among males within a population, even in the presence of direct male-male competition and a highly male-biased operational sex ratio. We hypothesize that low male reproductive skew might be a general characteristic in prolonged breeders with paternal care.

Copper-zinc-superoxide dismutase (CuZnSOD), an antioxidant gene from seahorse (Hippocampus abdominalis); molecular cloning, sequence characterization, antioxidant activity and potential peroxidation function of its recombinant protein.

PubMed

Perera, N C N; Godahewa, G I; Lee, Jehee

2016-10-01

Copper-zinc-superoxide dismutase (CuZnSOD) from Hippocampus abdominalis (HaCuZnSOD) is a metalloenzyme which belongs to the ubiquitous family of SODs. Here, we determined the characteristic structural features of HaCuZnSOD, analyzed its evolutionary relationships, and identified its potential immune responses and biological functions in relation to antioxidant defense mechanisms in the seahorse. The gene had a 5' untranslated region (UTR) of 67 bp, a coding sequence of 465 bp and a 3' UTR of 313 bp. The putative peptide consists of 154 amino acids. HaCuZnSOD had a predicted molecular mass of 15.94 kDa and a theoretical pI value of 5.73, which is favorable for copper binding activity. In silico analysis revealed that HaCuZnSOD had a prominent Cu-Zn_superoxide_dismutase domain, two Cu/Zn signature sequences, a putative N-glycosylation site, and several active sites including Cu(2+) and Zn(2+) binding sites. The three dimensional structure indicated a β-sheet barrel with 8 β-sheets and two short α-helical regions. Multiple alignment analyses revealed many conserved regions and active sites among its orthologs. The highest amino acid identity to HaCuZnSOD was found in Siniperca chuatsi (87.4%), while Maylandia zebra shared a close relationship in the phylogenetic analysis. Functional assays were performed to assess the antioxidant, biophysical and biochemical properties of overexpressed recombinant (r) HaCuZnSOD. A xanthine/XOD assay gave optimum results at pH 9 and 25 °C indicating these may be the best conditions for its antioxidant action in the seahorse. An MTT assay and flow cytometry confirmed that rHaCuZnSOD showed peroxidase activity in the presence of HCO3(-). In all the functional assays, the level of antioxidant activity of rHaCuZnSOD was concentration dependent; metal ion supplementation also increased its activity. The highest mRNA expressional level of HaCuZnSOD was found in blood. Temporal assessment under pathological stress showed a delay

Standardised classification of pre-release development in male-brooding pipefish, seahorses, and seadragons (Family Syngnathidae)

PubMed Central

2012-01-01

Background Members of the family Syngnathidae share a unique reproductive mode termed male pregnancy. Males carry eggs in specialised brooding structures for several weeks and release free-swimming offspring. Here we describe a systematic investigation of pre-release development in syngnathid fishes, reviewing available data for 17 species distributed across the family. This work is complemented by in-depth examinations of the straight-nosed pipefish Nerophis ophidion, the black-striped pipefish Syngnathus abaster, and the potbellied seahorse Hippocampus abdominalis. Results We propose a standardised classification of early syngnathid development that extends from the activation of the egg to the release of newborn. The classification consists of four developmental periods – early embryogenesis, eye development, snout formation, and juvenile – which are further divided into 11 stages. Stages are characterised by morphological traits that are easily visible in live and preserved specimens using incident-light microscopy. Conclusions Our classification is derived from examinations of species representing the full range of brooding-structure complexity found in the Syngnathidae, including tail-brooding as well as trunk-brooding species, which represent independent evolutionary lineages. We chose conspicuous common traits as diagnostic features of stages to allow for rapid and consistent staging of embryos and larvae across the entire family. In view of the growing interest in the biology of the Syngnathidae, we believe that the classification proposed here will prove useful for a wide range of studies on the unique reproductive biology of these male-brooding fish. PMID:23273265

Standardised classification of pre-release development in male-brooding pipefish, seahorses, and seadragons (Family Syngnathidae).

PubMed

Sommer, Stefan; Whittington, Camilla M; Wilson, Anthony B

2012-12-29

Members of the family Syngnathidae share a unique reproductive mode termed male pregnancy. Males carry eggs in specialised brooding structures for several weeks and release free-swimming offspring. Here we describe a systematic investigation of pre-release development in syngnathid fishes, reviewing available data for 17 species distributed across the family. This work is complemented by in-depth examinations of the straight-nosed pipefish Nerophis ophidion, the black-striped pipefish Syngnathus abaster, and the potbellied seahorse Hippocampus abdominalis. We propose a standardised classification of early syngnathid development that extends from the activation of the egg to the release of newborn. The classification consists of four developmental periods - early embryogenesis, eye development, snout formation, and juvenile - which are further divided into 11 stages. Stages are characterised by morphological traits that are easily visible in live and preserved specimens using incident-light microscopy. Our classification is derived from examinations of species representing the full range of brooding-structure complexity found in the Syngnathidae, including tail-brooding as well as trunk-brooding species, which represent independent evolutionary lineages. We chose conspicuous common traits as diagnostic features of stages to allow for rapid and consistent staging of embryos and larvae across the entire family. In view of the growing interest in the biology of the Syngnathidae, we believe that the classification proposed here will prove useful for a wide range of studies on the unique reproductive biology of these male-brooding fish.

Exaggerated sexual swellings and male mate choice in primates: testing the reliable indicator hypothesis in the Amboseli baboons.

PubMed

Fitzpatrick, Courtney L; Altmann, Jeanne; Alberts, Susan C

2015-06-01

The paradigm of competitive males vying to influence female mate choice has been repeatedly upheld, but, increasingly, studies also report competitive females and choosy males. One female trait that is commonly proposed to influence male mate choice is the exaggerated sexual swelling displayed by females of many Old World primate species. The reliable indicator hypothesis posits that females use the exaggerated swellings to compete for access to mates, and that the swellings advertise variation in female fitness. We tested the two main predictions of this hypothesis in a wild population of baboons ( Papio cynocephalus) . First, we examined the effect of swelling size on the probability of mate-guarding ('consortship') by the highest-ranking male and the behavior of those males that trailed consorshipts ('follower males'). Second, we asked whether a female's swelling size predicted several fitness measures. We found that high-ranking males do not prefer females with larger swellings (when controlling for cycle number and conception) and that females with larger swellings did not have higher reproductive success. Our study-the only complete test of the reliable indicator hypothesis in a primate population-rejects the idea that female baboons compete for mates by advertising heritable fitness differences. Furthermore, we found unambiguous evidence that males biased their mating decisions in favor of females who had experienced more sexual cycles since their most recent pregnancy. Thus, rather than tracking the potential differences in fitness between females, male baboons appear to track and target the potential for a given reproductive opportunity to result in fertilization.

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 ...

Exaggerated sexual swellings and male mate choice in primates: testing the reliable indicator hypothesis in the Amboseli baboons

PubMed Central

Fitzpatrick, Courtney L.; Altmann, Jeanne; Alberts, Susan C.

2015-01-01

The paradigm of competitive males vying to influence female mate choice has been repeatedly upheld, but, increasingly, studies also report competitive females and choosy males. One female trait that is commonly proposed to influence male mate choice is the exaggerated sexual swelling displayed by females of many Old World primate species. The reliable indicator hypothesis posits that females use the exaggerated swellings to compete for access to mates, and that the swellings advertise variation in female fitness. We tested the two main predictions of this hypothesis in a wild population of baboons (Papio cynocephalus). First, we examined the effect of swelling size on the probability of mate-guarding (‘consortship’) by the highest-ranking male and the behavior of those males that trailed consorshipts (‘follower males’). Second, we asked whether a female’s swelling size predicted several fitness measures. We found that high-ranking males do not prefer females with larger swellings (when controlling for cycle number and conception) and that females with larger swellings did not have higher reproductive success. Our study—the only complete test of the reliable indicator hypothesis in a primate population—rejects the idea that female baboons compete for mates by advertising heritable fitness differences. Furthermore, we found unambiguous evidence that males biased their mating decisions in favor of females who had experienced more sexual cycles since their most recent pregnancy. Thus, rather than tracking the potential differences in fitness between females, male baboons appear to track and target the potential for a given reproductive opportunity to result in fertilization. PMID:26752790

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

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.

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 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.

Mate choice screening in captive solitary carnivores: The role of male behavior and cues on mate preference and paternity in females of a model species, American mink (Neovison vison).

PubMed

Noer, Christina Lehmkuhl; Balsby, Thorsten Johannes Skovbjerg; Anistoroaei, Razvan; Stelvig, Mikkel; Dabelsteen, Torben

2017-12-01

Mate choice studies suggest that choosy females benefit from increased fecundity, litter size, and offspring survival. Thus, providing females with the opportunity to choose among potential mates, deemed genetically suitable based on studbook data, might improve breeding management in production and zoo animals and thereby the sustainability of captive populations. Investigating mate preference via odor from potential mates before animal transfer is a proposed strategy for incorporating mate choice into breeding management. In this study, we test whether olfactory cues and signals from males can be used to assess and measure female mate preference in American mink. Eighteen females were subjected to a 4-day stimulus test in which females showed a preference for one of two males' urine and feces. Subsequently, each female was subjected to a 10-day mate preference test involving the same two males of the first test. Paternity tests revealed that 13 females had offspring, which could be assigned to only one male, suggesting that these females performed a mate choice. In nine of these females preference during the stimulus test was directed toward the male that fathered their offspring. Our results suggest that even though there was a preference difference in scent stimulus trials from potential mates this preference was not predictive of eventual mate preference or paternity. Other factors such as aspects of male behavior seem to play a role, when the mates are introduced. Our study supports that mate preference and mate choice are complex matters influenced by multiple cues and signals. © 2017 Wiley Periodicals, Inc.

[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 contraception

PubMed Central

Chao, Jing; Page, Stephanie T.; Anderson, Richard A.

2015-01-01

Clear evidence shows that many men and women would welcome new male methods of contraception, but none have become available. The hormonal approach is based on suppression of gonadotropins and thus of testicular function and spermatogenesis, and has been investigated for several decades. This approach can achieve sufficient suppression of spermatogenesis for effective contraception in most men, but not all; the basis for these men responding insufficiently is unclear. Alternatively, the nonhormonal approach is based on identifying specific processes in sperm development, maturation and function. A range of targets has been identified in animal models, and targeted effectively. This approach, however, remains in the pre-clinical domain at present. There are, therefore, grounds for considering that safe, effective and reversible methods of contraception for men can be developed. PMID:24947599

Male contraception.

PubMed

Chao, Jing; Page, Stephanie T; Anderson, Richard A

2014-08-01

Clear evidence shows that many men and women would welcome new male methods of contraception, but none have become available. The hormonal approach is based on suppression of gonadotropins and thus of testicular function and spermatogenesis, and has been investigated for several decades. This approach can achieve sufficient suppression of spermatogenesis for effective contraception in most men, but not all; the basis for these men responding insufficiently is unclear. Alternatively, the non-hormonal approach is based on identifying specific processes in sperm development, maturation and function. A range of targets has been identified in animal models, and targeted effectively. This approach, however, remains in the pre-clinical domain at present. There are, therefore, grounds for considering that safe, effective and reversible methods of contraception for men can be developed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Male hypogonadism.

PubMed

Basaria, Shehzad

2014-04-05

Male hypogonadism is a clinical syndrome that results from failure to produce physiological concentrations of testosterone, normal amounts of sperm, or both. Hypogonadism may arise from testicular disease (primary hypogonadism) or dysfunction of the hypothalamic-pituitary unit (secondary hypogonadism). Clinical presentations vary dependent on the time of onset of androgen deficiency, whether the defect is in testosterone production or spermatogenesis, associated genetic factors, or history of androgen therapy. The clinical diagnosis of hypogonadism is made on the basis of signs and symptoms consistent with androgen deficiency and low morning testosterone concentrations in serum on multiple occasions. Several testosterone-replacement therapies are approved for treatment and should be selected according to the patient's preference, cost, availability, and formulation-specific properties. Contraindications to testosterone-replacement therapy include prostate and breast cancers, uncontrolled congestive heart failure, severe lower-urinary-tract symptoms, and erythrocytosis. Treatment should be monitored for benefits and adverse effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

Choosy Cannibals Preferentially Consume Siblings with Relatively Low Fitness Prospects.

PubMed

Dugas, Matthew B; McCormack, Larkin; Gadau, Alice; Martin, Ryan A

2016-07-01

When an individual can selfishly cannibalize a relative or altruistically set it free, the benefits of altruism will be positively associated with the relative's fitness prospects (the benefits it receives from altruism). We tested the prediction that altruism should be preferentially directed toward high-quality relatives using larvae of the New Mexican spadefoot toad (Spea multiplicata), a species in which tadpoles plastically express omnivore and carnivore ecomorphs. In a no-choice design, we presented carnivores with sibling or nonsibling omnivores varying in developmental stage, which is positively associated with survival in this toad's ephemeral larval environment. There was a significant interaction between relatedness and developmental stage on the probability of cannibalism: carnivores were overall more likely to cannibalize less developed omnivores, but this effect was exaggerated when the potential victim was a sibling. This evidence that altruists favor relatives with high fitness prospects highlights the numerous factors shaping altruism's payoffs.

Male osteoporosis.

PubMed

Rocchietti March, M; Pisani, D; Aliberti, G

2009-12-01

Osteoporosis is a worldwide major public health problem, defined as "a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility and susceptibility to fractures". Osteoporosis is diagnosed by bone mineral density measurement (T-score of -2.5 or below) also in men. However, most of the studies carried out in the last decade focused on pathogenesis, diagnosis and treatment of osteoporosis in women. In spite of this, recent epidemiological and observational studies have shown that osteoporosis in men is an increasingly important clinical issue. In part because the world population is aging, it is likely that the total number of hip fractures in men in 2025 will be similar to current estimates in women. Furthermore 25-33% of men in some populations will sustain osteoporotic fractures in their lifetime. Nevertheless, male osteoporosis is still underdiagnosed and further studies are required to clarify the pathogenesis and find out the right therapy. Prevention and early diagnosis are, nowadays, the best ways of treatment.

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;…

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 ...

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.

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.

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.

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)

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

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.

The Evolution of Mutual Mate Choice under Direct Benefits.

PubMed

Courtiol, Alexandre; Etienne, Loïc; Feron, Romain; Godelle, Bernard; Rousset, François

2016-11-01

In nature, the intensity of mate choice (i.e., choosiness) is highly variable within and between sexes. Despite growing empirical evidence of male and/or mutual mate choice, theoretical investigations of the joint evolution of female and male choosiness are few. In addition, previous approaches have often assumed an absence of trade-off between the direct benefits per mating and the lower mating rate that results from being choosy. Here we model the joint evolution of female and male choosiness when it is solely ruled by this fundamental trade-off. We show that this trade-off can generate a diversity of stable combinations of choosiness. Mutual mate choice can evolve only if both females and males exhibit long latency after mating. Furthermore, we show that an increase in choosiness in one sex does not necessarily prevent the evolution of mutual mate choice; the outcome depends on details shaping the trade-off: the life history, the decision rule for mate choice, and how the fecundity of a pair is shaped by the quality of both individuals. Last, we discuss the power of the sensitivity of the relative searching time (i.e., of the proportion of a lifetime spent searching for mates) as a predictor of the joint evolution of choosiness.

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.

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

[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.

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 ...

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 ...

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.

[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.

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.

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 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.

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

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...

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 ...

Sexually Aggressive College Males

ERIC Educational Resources Information Center

Kanin, Eugene J.

1971-01-01

The accumulated evidence of this paper suggests that sex aggression is largely the consequence of a particular type of socialization coupled with appropriate situational factors. These males tend to be generally aggressive; they show a strong tendency to deny love feeling for their mothers; their peers tend to stress sexual activity. (Author/BY)

Understanding African American Males

ERIC Educational Resources Information Center

Bell, Edward Earl

2010-01-01

The purpose of this study was to assess the socialization skills, self-esteem, and academic readiness of African American males in a school environment. Discussions with students and the School Perceptions Questionnaire provided data for this investigation. The intended targets for this investigation were African American students; however, there…

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 ...

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

Empowering Young Black Males

ERIC Educational Resources Information Center

Kafele, Baruti K.

2012-01-01

Of all the challenges we face in education today, the author can think of none greater than the challenge of motivating, educating, and empowering black male learners. The fact that this group of students is in crisis is evident on multiple levels, starting with graduation rates. According to the Schott Foundation (2008), the U.S. high school…

Educating African American Males

ERIC Educational Resources Information Center

Bell, Edward E.

2010-01-01

Background: Schools across America spend money, invest in programs, and sponsor workshops, offer teacher incentives, raise accountability standards, and even evoke the name of Obama in efforts to raise the academic achievement of African American males. Incarceration and college retention rates point to a dismal plight for many African American…

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

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

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.

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

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

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."

[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.

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.

Mating and male pheromone kill Caenorhabditis males through distinct mechanisms.

PubMed

Shi, Cheng; Runnels, Alexi M; Murphy, Coleen T

2017-03-14

Differences in longevity between sexes is a mysterious yet general phenomenon across great evolutionary distances. To test the roles of responses to environmental cues and sexual behaviors in longevity regulation, we examined Caenorhabditis male lifespan under solitary, grouped, and mated conditions. We find that neurons and the germline are required for male pheromone-dependent male death. Hermaphrodites with a masculinized nervous system secrete male pheromone and are susceptible to male pheromone killing. Male pheromone-mediated killing is unique to androdioecious Caenorhabditis , and may reduce the number of males in hermaphroditic populations; neither males nor females of gonochoristic species are susceptible to male pheromone killing. By contrast, mating-induced death, which is characterized by germline-dependent shrinking, glycogen loss, and ectopic vitellogenin expression, utilizes distinct molecular pathways and is shared between the sexes and across species. The study of sex- and species-specific regulation of aging reveals deeply conserved mechanisms of longevity and population structure regulation.

Gynecomastia in Adolescent Males

PubMed Central

Lemaine, Valerie; Cayci, Cenk; Simmons, Patricia S.; Petty, Paul

2013-01-01

Gynecomastia is defined as an enlargement of the male breast. It is often benign, and can be the source of significant embarrassment and psychological distress. A general medical history and careful physical examination are essential to distinguish normal developmental variants from pathological causes. Treatment is geared toward the specific etiology when identified. In the majority of cases of pubertal gynecomastia, observation and reassurance are the mainstays of therapy as the condition usually resolves naturally. Pharmacological treatment and surgery are recommended only in selected cases. PMID:24872741

Sexual Selection on male cuticular hydrocarbons via male-male competition and female choice.

PubMed

Lane, S M; Dickinson, A W; Tregenza, T; House, C M

2016-07-01

Traditional views of sexual selection assumed that male-male competition and female mate choice work in harmony, selecting upon the same traits in the same direction. However, we now know that this is not always the case and that these two mechanisms often impose conflicting selection on male sexual traits. Cuticular hydrocarbons (CHCs) have been shown to be linked to both social dominance and male attractiveness in several insect species. However, although several studies have estimated the strength and form of sexual selection imposed on male CHCs by female mate choice, none have established whether these chemical traits are also subject to sexual selection via male-male competition. Using a multivariate selection analysis, we estimate and compare sexual selection exerted by male-male competition and female mate choice on male CHC composition in the broad-horned flour beetle Gnatocerus cornutus. We show that male-male competition exerts strong linear selection on both overall CHC abundance and body size in males, while female mate choice exerts a mixture of linear and nonlinear selection, targeting not just the overall amount of CHCs expressed but the relative abundance of specific hydrocarbons as well. We discuss the potential implications of this antagonistic selection with regard to male reproductive success. © 2016 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

[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.

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

Meiosis in male Drosophila

PubMed Central

McKee, Bruce D.; Yan, Rihui; Tsai, Jui-He

2012-01-01

Meiosis entails sorting and separating both homologous and sister chromatids. The mechanisms for connecting sister chromatids and homologs during meiosis are highly conserved and include specialized forms of the cohesin complex and a tightly regulated homolog synapsis/recombination pathway designed to yield regular crossovers between homologous chromatids. Drosophila male meiosis is of special interest because it dispenses with large segments of the standard meiotic script, particularly recombination, synapsis and the associated structures. Instead, Drosophila relies on a unique protein complex composed of at least two novel proteins, SNM and MNM, to provide stable connections between homologs during meiosis I. Sister chromatid cohesion in Drosophila is mediated by cohesins, ring-shaped complexes that entrap sister chromatids. However, unlike other eukaryotes Drosophila does not rely on the highly conserved Rec8 cohesin in meiosis, but instead utilizes two novel cohesion proteins, ORD and SOLO, which interact with the SMC1/3 cohesin components in providing meiotic cohesion. PMID:23087836

Sport and male sexuality.

PubMed

Sgrò, P; Di Luigi, L

2017-09-01

The relationships between sport and sexuality in males are of great social and clinical interest, because of sports and motor activities that highly promote social and sexual relationships. Even if few literature exist, two main questions should be taken into account: whether and how physical exercise and sport positively or negatively influence sexual health and behavior and/or whether and how sexual behavior may affect a sub-sequent sport performance. Physical exercise and sport per se can influence, positively or negatively, the hypothalamic-pituitary-testicular axis function and, consequently, the individual's reproductive and/or sexual health. This depends on individual factors such as genetic and epigenetic ones and on different variables involved in the practice of sport activities (type of sport, intensity and duration of training, doping and drug use and abuse, nutrition, supplements, psychological stress, allostatic load, etc.). If well conducted, motor and sport activities could have beneficial effects on sexual health in males. Among different lifestyle changes, influencing sexual health, regular physical activity is fundamental to antagonize the onset of erectile dysfunction (ED). However, competitive sport can lead both reproductive and/or sexual tract damages and dysfunctions, transient (genital pain, hypoesthesia of the genitalia, hypogonadism, DE, altered sexual drive, etc.) or permanent (hypogonadism, DE, etc.), by acting directly (traumas of the external genitalia, saddle-related disorders in cyclists, etc.) or indirectly (exercise-related hypogonadism, drug abuse, doping, stress, etc.). Sexual activities shortly performed before a sport competition could differently influence sport performance. Due to the few existing data, it is advisable to avoid an absolute pre-competition sexual abstinence.

Slow stamen movement in a perennial herb decreases male-male and male-female interference.

PubMed

Wang, Lingyan; Bao, Yu; Wang, Hanxi; He, Chunguang; Wang, Ping; Sheng, Lianxi; Tang, Zhanhui

2017-07-01

Approximately 80 % of angiosperm species produce hermaphroditic flowers, which face the problem of male - male sexual interference (one or more anthers gets in the way of disseminating pollen from other anthers) or male - female sexual interference (the pistil interferes with disseminating pollen from the anthers by preventing the anther from touching a pollinator, or the anther prevents pollinator from depositing outcross pollen on the stigma). Slow stamen movement in hermaphrodite flowers has been interpreted as an adaptation for reducing male - male sexual interference. Using slow stamen movement in Lychnis cognata (Caryophyllaceae), this study presents new evidence that this phenomenon can reduce both male - male and male - female sexual interference. Ten stamens in L. cognata flowers vertically elongated their filaments in two batches and displayed similar patterns in pollen dispensing. More importantly, 10 stamens bend out of the floral centre by curving the filament also in 2 batches and pollen grains located at the flower centre displayed the highest viability. Thus, three stages of stamen movement can be identified, comprising two male stages (M1 and M2) and one female stage (F). We found that the main pollinator for L. cognata, Bhutanitis yulongensis (Papilionodae) generally preferred M1 flowers. Manipulation experiments show that vertical stamen movement enabled the anthers to dehisce at different times to prolong the presentation of pollen grains. Horizontal movement of the stamen decreased both male - male and male - female interference. However, vertical stamen movement had a minor role in increasing amount of pollen received by the stigma. This study provides the first direct experimental evidence of concurrent male - male and male - female interference in a flower. We suggest that the selection pressure to reduce such interference might be a strong force in floral evolution. We also propose that other selective pressure, including pollen

Mating and male pheromone kill Caenorhabditis males through distinct mechanisms

PubMed Central

Shi, Cheng; Runnels, Alexi M; Murphy, Coleen T

2017-01-01

Differences in longevity between sexes is a mysterious yet general phenomenon across great evolutionary distances. To test the roles of responses to environmental cues and sexual behaviors in longevity regulation, we examined Caenorhabditis male lifespan under solitary, grouped, and mated conditions. We find that neurons and the germline are required for male pheromone-dependent male death. Hermaphrodites with a masculinized nervous system secrete male pheromone and are susceptible to male pheromone killing. Male pheromone-mediated killing is unique to androdioecious Caenorhabditis, and may reduce the number of males in hermaphroditic populations; neither males nor females of gonochoristic species are susceptible to male pheromone killing. By contrast, mating-induced death, which is characterized by germline-dependent shrinking, glycogen loss, and ectopic vitellogenin expression, utilizes distinct molecular pathways and is shared between the sexes and across species. The study of sex- and species-specific regulation of aging reveals deeply conserved mechanisms of longevity and population structure regulation. DOI: http://dx.doi.org/10.7554/eLife.23493.001 PMID:28290982

Management of male osteoporosis.

PubMed

Cortet, B; Vasseur, J; Grardel, B; Catanzariti, L; Marchandise, X; Delcambre, B

2001-05-01

The objective of this study was to evaluate the efficacy of treatments for male osteoporosis selected based on the cause of the disease. Sixty-three men with osteoporosis (T-score at the lumbar spine and/or femoral neck lower than -2.5) with a mean age of 53+/-11 years were studied. Forty-three (68.3%) had a history of fracturing without trauma (vertebral fractures, 37 patients, 57%). Treatments were as follows: idiopathic osteoporosis: calcium and vitamin D supplements (N = 10) or cyclical etidronate for 2 weeks followed by calcium and vitamin D supplements for 76 days (N = 29); moderate idiopathic phosphate diabetes: calcitriol and phosphate (N = 15); idiopathic hypercalciuria: hydrochlorothiazide (N = 6); and hypogonadism: testosterone (N = 3). Percentage change in bone mineral density (mean +/- standard error of the mean) after 18 months: calcium and vitamin D (lumbar spine: 0.6+/-2; femoral neck: 2.2+/-2.2); etidronate (lumbar spine: 3.6+/-1.4*; femoral neck: 0.5+/-1); calcitriol (lumbar spine: 7.0+/-3.5*; femoral neck: 0.0+/-1.4); thiazide diuretic (lumbar spine: 1+/-3.2; femoral neck: -2.3+/-3.7); and testosterone (lumbar spine: 6.8+/-6.4; femoral neck: 2.5+/-2.7), where *P < 0.05 versus baseline. Gastrointestinal side effects occurred in three patients (4.8%), including two on calcitriol-phosphate therapy and one on etidronate therapy. Of the six (9.5%) patients who experienced incident fractures, four were on etidronate, one on calcitriol-phosphate, and one on calcium-vitamin D. No patients discontinued their treatment because of side effects. Etidronate and the combination of calcitriol-phosphate produce a significant increase in lumbar spine bone mass in men with idiopathic osteoporosis or moderate idiopathic phosphate diabetes.

Coaching the alpha male.

PubMed

Ludeman, Kate; Erlandson, Eddie

2004-05-01

Highly intelligent, confident, and successful, alpha males represent about 70% of all senior executives. Natural leaders, they willingly take on levels of responsibility most rational people would find overwhelming. But many of their quintessential strengths can also make alphas difficult to work with. Their self-confidence can appear domineering. Their high expectations can make them excessively critical. Their unemotional style can keep them from inspiring their teams. That's why alphas need coaching to broaden their interpersonal tool kits while preserving their strengths. Drawing from their experience coaching more than 1,000 senior executives, the authors outline an approach tailored specifically for the alpha. Coaches get the alpha's attention by inundating him with data from 360-degree feedback presented in ways he will find compelling--both hard-boiled metrics and vivid verbatim comments from colleagues about his strengths and weaknesses. A 360-degree assessment is a wake-up call for most alphas, providing undeniable proof that their behavior doesn't work nearly as well as they think it does. That paves the way for a genuine commitment to change. In order to change, the alpha must venture into unfamiliar--and often uncomfortable--psychological territory. He must admit vulnerability, accept accountability not just for his own work for others', connect with his underlying emotions, learn to motivate through a balance of criticism and validation, and become aware of unproductive behavior patterns. The goal of executive coaching is not simply to treat the alpha as an individual problem but to improve the entire team dynamic. Initial success creates an incentive to persevere, and the virtuous cycle reverberates throughout the entire organization.

Host plant choice in the comma butterfly-larval choosiness may ameliorate effects of indiscriminate oviposition.

PubMed

Gamberale-Stille, Gabriella; Söderlind, Lina; Janz, Niklas; Nylin, Sören

2014-08-01

In most phytophagous insects, the larval diet strongly affects future fitness and in species that do not feed on plant parts as adults, larval diet is the main source of nitrogen. In many of these insect-host plant systems, the immature larvae are considered to be fully dependent on the choice of the mothers, who, in turn, possess a highly developed host recognition system. This circumstance allows for a potential mother-offspring conflict, resulting in the female maximizing her fecundity at the expense of larval performance on suboptimal hosts. In two experiments, we aimed to investigate this relationship in the polyphagous comma butterfly, Polygonia c-album, by comparing the relative acceptance of low- and medium-ranked hosts between females and neonate larvae both within individuals between life stages, and between mothers and their offspring. The study shows a variation between females in oviposition acceptance of low-ranked hosts, and that the degree of acceptance in the mothers correlates with the probability of acceptance of the same host in the larvae. We also found a negative relationship between stages within individuals as there was a higher acceptance of lower ranked hosts in females who had abandoned said host as a larva. Notably, however, neonate larvae of the comma butterfly did not unconditionally accept to feed from the least favorable host species even when it was the only food source. Our results suggest the possibility that the disadvantages associated with a generalist oviposition strategy can be decreased by larval participation in host plant choice. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Choosy Wolves? Heterozygote Advantage But No Evidence of MHC-Based Disassortative Mating.

PubMed

Galaverni, Marco; Caniglia, Romolo; Milanesi, Pietro; Lapalombella, Silvana; Fabbri, Elena; Randi, Ettore

2016-03-01

A variety of nonrandom mate choice strategies, including disassortative mating, are used by vertebrate species to avoid inbreeding, maintain heterozygosity and increase fitness. Disassortative mating may be mediated by the major histocompatibility complex (MHC), an important gene cluster controlling immune responses to pathogens. We investigated the patterns of mate choice in 26 wild-living breeding pairs of gray wolf (Canis lupus) that were identified through noninvasive genetic methods and genotyped at 3 MHC class II and 12 autosomal microsatellite (STR) loci. We tested for deviations from random mating and evaluated the covariance of genetic variables at functional and STR markers with fitness proxies deduced from pedigree reconstructions. Results did not show evidences of MHC-based disassortative mating. Rather we found a higher peptide similarity between mates at MHC loci as compared with random expectations. Fitness values were positively correlated with heterozygosity of the breeders at both MHC and STR loci, whereas they decreased with relatedness at STRs. These findings may indicate fitness advantages for breeders that, while avoiding highly related mates, are more similar at the MHC and have high levels of heterozygosity overall. Such a pattern of MHC-assortative mating may reflect local coadaptation of the breeders, while a reduction in genetic diversity may be balanced by heterozygote advantages. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

"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…

Male tolerance and male-male bonds in a multilevel primate society.

PubMed

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

2014-10-14

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.

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…

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

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

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.

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.

[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.

[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.

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.

[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.

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.

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.

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

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

Male Responses to Female Aggression.

ERIC Educational Resources Information Center

Russell, Gordon W.; And Others

1988-01-01

Randomly assigned 60 male undergraduates to view film clip of professional lady wrestlers or of mud wrestling, or to no-film control. Both films produced negative changes in mood states, principally increase in aggression and decrease in social affection. Viewing films did not produce changes in men's acceptance of interpersonal violence against…

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.

Black Male Labor Force Participation.

ERIC Educational Resources Information Center

Baer, Roger K.

This study attempts to test (via multiple regression analysis) hypothesized relationships between designated independent variables and age specific incidences of labor force participation for black male subpopulations in 54 Standard Metropolitan Statistical Areas. Leading independent variables tested include net migration, earnings, unemployment,…

Promoting Flexibility in Male Roles.

ERIC Educational Resources Information Center

Moody, Charles D., Comp.; Linn, Eleanor, Ed.

1986-01-01

In this publication issues are discussed which pertain to male roles and fatherhood. "From the Desk of the Director" (Charles D. Moody, Sr.) discusses the need for increased role flexibility for men in general and black men in particular. The lead article, "Equity: A Question in Balance" (D. Groves Dugger), delves into the causes and consequences…

Male Depression: Understanding the Issues

MedlinePlus

... 2015;15:1135. Gagnon M, et al. Male depression and suicide: What NPs should know. The Nurse Practitioner. 2015;40:50. Rice SM, et al. Men's perceived barriers to help seeking for depression: Longitudinal findings relative to symptom onset and duration. ...

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.

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.

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.

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.

Male-mimicking females increase male-male interactions, and decrease male survival and condition in a female-polymorphic damselfly.

PubMed

Gering, Eben J

2017-05-01

Biologists are still discovering diverse and powerful ways sexual conflicts shape biodiversity. The present study examines how the proportion of females in a population that exhibit male mimicry, a mating resistance trait, influences conspecific males' behavior, condition, and survival. Like most female-polymorphic damselflies, Ischnura ramburii harbors both "andromorph" females, which closely resemble males, and sexually dimorphic "gynomorph" counterparts. There is evidence that male mimicry helps andromorphs evade detection and harassment, but males can also learn to target locally prevalent morph(s) via prior mate encounters. I hypothesized that the presence of male mimics could therefore predispose males to mate recognition errors, and thereby increase rates of costly male-male interactions. Consistent with this hypothesis, male-male interaction rates were highest in mesocosms containing more andromorph (vs. gynomorph) females. Males in andromorph-biased mesocosms also had lower final body mass and higher mortality than males assigned to gynomorph-majority treatments. Male survival and body mass were each negatively affected by mesocosm density, and mortality data revealed a marginally significant interaction between andromorph frequency and population density. These findings suggest that, under sufficiently crowded conditions, female mating resistance traits such as male mimicry could have pronounced indirect effects on male behavior, condition, and survival. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

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…

Some dynamics of male chauvinism.

PubMed

Woods, S M

1976-01-01

Male chauvinism was studied in the psychoanalytic therapy of 11 men. It refers to the maintenance of fixed beliefs and attitudes of male superiority, associated with overt or covert depreciation of women. Challenging chauvinist attitudes often results in anxiety or other symptoms. It is frequently not investigated in psychotherapy because it is ego-syntonic, parallels cultural attitudes, and because therapists often share similar bias or neurotic conflict. Chauvinism was found to represent an attempt to ward off anxiety and shame arising from one or more of four prime sources: unresolved infantile strivings and regressive wishes, hostile envy of women, oedipal anxiety, and power and dependency conflicts related to masculine self-esteem. Mothers were more important than fathers in the development of chauvinism, and resolution was sometimes associated with decompensation in wives.

Male reprotoxicity and endocrine disruption

PubMed Central

Campion, Sarah; Catlin, Natasha; Heger, Nicholas; McDonnell, Elizabeth V.; Pacheco, Sara E.; Saffarini, Camelia; Sandrof, Moses A.; Boekelheide, Kim

2013-01-01

Mammalian reproductive tract development is a tightly regulated process that can be disrupted following exposure to drugs, toxicants, endocrine disrupting chemicals or other compounds via alterations to gene and protein expression or epigenetic regulation. Indeed, the impacts of developmental exposure to certain toxicants may not be fully realized until puberty or adulthood when the reproductive tract becomes sexually mature and altered functionality is manifested. Exposures that occur later in life, once development is complete, can also disrupt the intricate hormonal and paracrine interactions responsible for adult functions, such as spermatogenesis. In this chapter, the biology and toxicology of the male reproductive tract is explored, proceeding through the various life stages including in utero development, puberty, adulthood and senescence. Special attention is given to the discussion of endocrine disrupting chemicals, chemical mixtures, low dose effects, transgenerational effects, and potential exposure-related causes of male reproductive tract cancers. PMID:22945574

Novel Therapy for Male Hypogonadism.

PubMed

Carrasquillo, Robert; Chu, Kevin; Ramasamy, Ranjith

2018-06-09

Hypogonadism and the treatment of low testosterone is increasingly a subject of medical inquiry and controversy. The few treatments that are FDA-approved such as testosterone topicals, injections, and pellets create significant demand from patients for treatments with more convenient means of administration, fewer adverse effects, and the ability to maintain male fertility. Off-label drugs are in abundant use for low testosterone, including selective estrogen receptor modulators, gonadotropins, and aromatase inhibitors. In this review, we summarize the evidence in support of commonly used treatments for male hypogonadism, as well as discuss recent updates in the development of novel therapeutics. New therapies include nasal testosterone, new oral testosterone formulations, anabolic-androgenic steroids, and selective androgen receptor modulators.

Childhood indicators of male homosexuality.

PubMed

Whitam, F L

1977-03-01

Questionnaires were administered to 206 male homosexuals and 78 male heterosexuals. The most important aspects of the questionnaire dealt with six "childhood indicators" of later adult homosexuality: (1) interest in dolls, (2) cross-dressing, (3) preference for company of girls rather than boys in childhood games, (4) preference for company of older women rather than older men, (5) being regarded by other boys as a sissy, (6) sexual interest in other boys rather than girls in childhood sex play. Significant differences were found between homosexuals and heterosexuals with respect to all six indicators. Moreover, it was found that the stronger one's homosexual orientation the greater was the number of childhood indicators. It is concluded that there are behavioral aspects related to one's sexual orientation which may begin to emerge early in childhood.

Epigenetic disorders and male subfertility.

PubMed

Boissonnas, Céline Chalas; Jouannet, Pierre; Jammes, Hélène

2013-03-01

To provide a link between epigenetics and male subfertility at the DNA, histone-protamine, and RNA levels and its consequences on fertilization and embryo development. Review of the relevant literature. University-based clinical and research laboratories. Fertile and infertile men. None. Critical review of the literature. Epigenetic markers can be modified in infertile patients. Epigenetic modifications include methylation loss or gain on the global level and on imprinted genes, high levels of histone retention in spermatozoa, and deficiencies in some transcripts involved in spermatogenesis. Interestingly, these abnormalities are all linked together, because DNA methylation maintenance depends on DNA histone-protamine configuration which itself is stabilized by spermatozoal RNAs. The paternal genome has long been considered to be silent and passive in embryo formation. The epigenetic processes associated with the paternal DNA genome highlights its importance in male fertility as well as for embryo development. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

[Male contraception and its perspectives].

PubMed

Belaisch, J

1982-11-01

Doctors specializing in male contraception are aware of the very real difficulties hindering the development of an effective method in this field. Others believe that the reason this type of contraception is lagging behind is male chauvinism or a certain fear that men have of losing their virility along with their fertilizing capacity. Since available methods of contraception (condom, vasectomy) have low levels of acceptability and reversibility, research has proceeded along other avenues. 1) Gossypol reduces the number and motility of spermatozoa but its general side effects are not exceptional. 2) Restraining hormonal action (progrestogens, LH-RH agonists) also reduce testicular function and for this reason, require simultaneous administration of androgens. Thus far this has not been resolved; azoospermia is not obtained in every case and when it is, it does not necessarily last. 3) A method involving the epididymis, with a view to preventing spermatozoa from acquiring their normal motility and fertilizing capacity by affecting protein and enzyme synthesis, is also being studied. Perhaps, as has been suggested by the Bicetre Hospital research team, we should be content with methods applicable to certain categories of men. Male contraception would then develop step by step rather than by huge bounds as female contraception. full text

Male contraception: another Holy Grail.

PubMed

Murdoch, Fern E; Goldberg, Erwin

2014-01-15

The idea that men should participate in family planning by playing an active role in contraception has become more acceptable in recent years. Up to the present the condom and vasectomy have been the main methods of male contraception. There have been and continue to be efforts to develop an acceptable hormonal contraceptive involving testosterone (T) suppression. However the off target affects, delivery of the analogs and the need for T replacement have proven difficult obstacles to this technology. Research into the development of non-hormonal contraception for men is progressing in several laboratories and this will be the subject of the present review. A number of promising targets for the male pill are being investigated. These involve disruption of spermatogenesis by compromising the integrity of the germinal epithelium, interfering with sperm production at the level of meiosis, attacking specific sperm proteins to disrupt fertilizing ability, or interfering with the assembly of seminal fluid components required by ejaculated sperm for acquisition of motility. Blocking contractility of the vas deferens smooth muscle vasculature to prevent ejaculation is a unique approach that prevents sperm from reaching the egg. We shall note the lack of interest by big pharma with most of the support for male contraception provided by the NIH. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Sexual dysfunction and male infertility.

PubMed

Lotti, Francesco; Maggi, Mario

2018-05-01

Infertility affects up to 12% of all men, and sexual dysfunction occurs frequently in men of reproductive age, causing infertility in some instances. In infertile men, hypoactive sexual desire and lack of sexual satisfaction are the most prevalent types of sexual dysfunction, ranging from 8.9% to 68.7%. Erectile dysfunction and/or premature ejaculation, evaluated with validated tools, have a prevalence of one in six infertile men, and orgasmic dysfunction has a prevalence of one in ten infertile men. In addition, infertile men can experience a heavy psychological burden. Infertility and its associated psychological concerns can underlie sexual dysfunction. Furthermore, general health perturbations can lead to male infertility and/or sexual dysfunction. Erectile dysfunction and male infertility are considered proxies for general health, the former underlying cardiovascular disorders and the latter cancerous and noncancerous conditions. The concept that erectile dysfunction in infertile men might be an early marker of poor general health is emerging. Finally, medications used for general health problems can cause sperm abnormalities and sexual dysfunction. The treatment of some causes of male infertility might improve semen quality and reverse infertility-related sexual dysfunction. In infertile men, an investigation of sexual, general, and psychological health status is advisable to improve reproductive problems and general health.

Surgical treatment for male prolactinoma

PubMed Central

Song, Yi-Jun; Chen, Mei-Ting; Lian, Wei; Xing, Bing; Yao, Yong; Feng, Ming; Wang, Ren-Zhi

2017-01-01

Abstract A total of 184 cases of surgically treated male prolactinoma were analyzed retrospectively to summarize the outcome of this surgical intervention. We analyzed the general characteristics, clinical manifestations, hormone levels, imaging features, preoperative treatments, surgical outcomes, pathology results, and follow-up records for all included patients. The most common clinical manifestations included sexual dysfunction (47.4%), headache (55.9%), and visual disturbance (46.7%). Serum prolactin levels ranged from 150 to 204,952 ng/mL. Tumor size varied from 6 to 70 mm. Pituitary adenomas grew in a parasellar pattern with visual deficits occurring 40.7% of the time. After surgical therapy, 88.6% of patients achieved symptom relief, and 98.4% experienced an immediate postoperative decline in prolactin level. Fifty-seven patients (31.0%) achieved initial remission, and 26 patients (45.6%) experienced recurrence. Hence, our results suggest that in male prolactinoma characterized by a large pituitary diameter and high serum prolactin level, tumor size predicts the degree of gross resection. The prognostic predictors included preoperative tumor growth pattern and Ki-67 index. Citation: Yi-jun S, Mei-ting C, Wei L, Bing X, Yong Y, Ming F, Ren-zhi W. (2016) Surgical treatment for male prolactinoma: a retrospective study of 184 cases PMID:28079813

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-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.

Male factor infertility and ART

PubMed Central

Tournaye, Herman

2012-01-01

For years, the management and treatment of male factor infertility has been ‘experience' and not ‘evidence' based. Although not evidence-based, current clinical practice involves extensive use of assisted reproductive techniques (ART). Where specific treatments are not indicated or have failed, ART have become popular adjunctive treatments for alleviating male factor infertility. According to the limited evidence available, intrauterine insemination (IUI) may be considered as a first-line treatment in a couple in which the female partner has a normal fertility status and at least 1×106 progressively motile spermatozoa are recovered after sperm preparation. If no pregnancy is achieved after 3–6 cycles of IUI, optimized in vitro fertilization (IVF) can be proposed. When less than 0.5×106 progressively motile spermatozoa are obtained after seminal fluid processing or sperm are recovered surgically from the testis or epididymis, intracytoplasmic sperm injection (ICSI) should be performed. Although the outcome of no other ART has ever been scrutinized as much before, no large-scale ‘macroproblems' have as yet been observed after ICSI. Yet, ICSI candidates should be rigorously screened before embarking on IVF or ICSI, and thoroughly informed of the limitations of our knowledge on the hereditary aspects of male infertility and the safety aspects of ART. PMID:22179511

Triptolide: a potential male contraceptive.

PubMed

Lue, Y; Sinha Hikim, A P; Wang, C; Leung, A; Baravarian, S; Reutrakul, V; Sangsawan, R; Chaichana, S; Swerdloff, R S

1998-01-01

The antifertility effect of triptolide and other related compounds, isolated from Tripterygium wilfordii, has been demonstrated in male rats. The exact sites and mechanism of action of triptolide remain unknown. Our objectives were to determine whether triptolide at selected dose levels that induce infertility has any detrimental effects on the testes and to determine the sites and the possible mechanisms of its action. Groups of six adult male Sprague-Dawley rats were given oral administration of either vehicle (control group) or triptolide (50 or 100 microg/kg body weight) daily for 35 or 70 days. Body weight gain was normal in all treated groups. All six rats treated with a high dosage of triptolide were infertile during the second (63-70 days) mating trial. A lower dose (50 microg) of triptolide gave intermediate fertility values. Plasma levels of luteinizing hormone, follicle-stimulating hormone, testosterone, and intratesticular testosterone were not significantly different between control and triptolide-treated groups. Cauda epididymal sperm content was decreased by 68% and the motility, which averaged 58.2% in the control rat, was reduced to almost zero. No effects of triptolide were observed on testis and accessory organs weight, volumes of tubular lumen and the total Leydig cells, tubule diameter, and the number of Sertoli cells, spermatogonia, preleptotene (PL), and pachytene (P) spermatocytes. There were, however, modest but significant decreases in tubule volume and the number of round spermatids at stages VII-VIII. No changes in the germ cell apoptotic index measured at stages VII-VIII and XIV-I were noted between controls and rats rendered infertile with a high dose of triptolide. Thus, triptolide, at a dose level that induces complete infertility in the adult rats, has minimal adverse effects on the testes and acts primarily on the epididymal sperm making triptolide an attractive lead as a post-testicular male contraceptive.

Male homosexuality: nature or culture?

PubMed

Jannini, Emmanuele A; Blanchard, Ray; Camperio-Ciani, Andrea; Bancroft, John

2010-10-01

Debate continues on whether or not male homosexuality (MH) is a result of biological or cultural factors. The debate persists despite the fact that these two sides have different abilities to create a scientific environment to support their cause. Biological theorists produced evidence, however, that these are not always robust. On the other hand, social theorists, without direct evidence confirming their positions, criticize, with good argument, methods and results of the other side. The aim of this Controversy is to understand the reasons of both perspectives. Two scientists (R.B. and A.C.C.) with expertise in the area of biology of MH were asked to contribute their opinions. The nurture position is discussed by a third expert in sexology (J.B.). Expert opinion supported by the critical review of the currently available literature. The role of the Controversy's editor (E.A.J.) is to highlight the strengths and weaknesses of both sides. The two experts of the biological issue answer with their data to the questions: “Is male homosexuality partly explainable by immunology?” and “How is male homosexuality a Darwinian paradox?”, respectively. Genetic and immunological factors, birth order, and fertility of relatives are largely discussed. Finally, the expert sustaining the idea that culture and experiences are important determining factors in sexual orientation used a psychosocial and holistic perspective to explain his position. The JSM's readers should recognize that there are several biological factors in MH. However, these findings do not seem to be able to explain all cases of homosexuality. Some others may be due to particular environmental factors. The issue is complicated and multifactorial, suggesting that further research should be undertaken to produce the final answer to the question raised in this Controversy section.

Male sexual dysfunction in Asia

PubMed Central

Ho, Christopher CK; Singam, Praveen; Hong, Goh Eng; Zainuddin, Zulkifli Md

2011-01-01

Sex has always been a taboo subject in Asian society. However, over the past few years, awareness in the field of men's sexual health has improved, and interest in sexual health research has recently increased. The epidemiology and prevalence of erectile dysfunction, hypogonadism and premature ejaculation in Asia are similar in the West. However, several issues are specific to Asian males, including culture and beliefs, awareness, compliance and the availability of traditional/complementary medicine. In Asia, sexual medicine is still in its infancy, and a concerted effort from the government, relevant societies, physicians and the media is required to propel sexual medicine to the forefront of health care. PMID:21643001

Male-mediated developmental toxicity

SciTech Connect

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

Job strain and male fertility.

PubMed

Hjollund, Niels Henrik I; Bonde, Jens Peter E; Henriksen, Tine Brink; Giwercman, Aleksander; Olsen, Jørn

2004-01-01

Job strain, defined as high job demands and low job control, has not previously been explored as a possible determinant of male fertility. We collected prospective data on job strain among men, and describe the associations with semen quality and probability of conceiving a clinical pregnancy during a menstrual cycle. Danish couples (N = 399) who were trying to become pregnant for the first time were followed for up to 6 menstrual periods. All men collected semen samples, and a blood sample was drawn from both partners. Job demand and job control were measured by a self-administered questionnaire at entry, and in each cycle the participants recorded changes in job control or job demand during the previous 30 days. In adjusted analyses, no associations were found between any semen characteristic or sexual hormones and any job strain variable. The odds for pregnancy were not associated with job strain. Psychologic job strain encountered in normal jobs in Denmark does not seem to affect male reproductive function.

Neural circuitry coordinating male copulation

PubMed Central

Pavlou, Hania J; Lin, Andrew C; Neville, Megan C; Nojima, Tetsuya; Diao, Fengqiu; Chen, Brian E; White, Benjamin H; Goodwin, Stephen F

2016-01-01

Copulation is the goal of the courtship process, crucial to reproductive success and evolutionary fitness. Identifying the circuitry underlying copulation is a necessary step towards understanding universal principles of circuit operation, and how circuit elements are recruited into the production of ordered action sequences. Here, we identify key sex-specific neurons that mediate copulation in Drosophila, and define a sexually dimorphic motor circuit in the male abdominal ganglion that mediates the action sequence of initiating and terminating copulation. This sexually dimorphic circuit composed of three neuronal classes – motor neurons, interneurons and mechanosensory neurons – controls the mechanics of copulation. By correlating the connectivity, function and activity of these neurons we have determined the logic for how this circuitry is coordinated to generate this male-specific behavior, and sets the stage for a circuit-level dissection of active sensing and modulation of copulatory behavior. DOI: http://dx.doi.org/10.7554/eLife.20713.001 PMID:27855059

Personality impairment in male pedophiles.

PubMed

Cohen, Lisa J; McGeoch, Pamela G; Watras-Gans, Sniezyna; Acker, Sara; Poznansky, Olga; Cullen, Ken; Itskovich, Yelena; Galynker, Igor

2002-10-01

Despite the large body of literature on the psychological sequelae of childhood sexual abuse, the literature on the psychopathology of pedophiles is surprisingly underdeveloped. The present article explores the hypothesis that pedophiles evidence deficits in interpersonal functioning (lack of assertiveness and empathy, passive-aggressiveness) and in self-concept, which might contribute to the motivation for pedophilic acts, as well as elevated sociopathy, impulsivity, and propensity for cognitive distortions, which might underlie the inhibitory failure. Twenty male heterosexual pedophiles (DSM-IV criteria) recruited from an outpatient clinic for sex offenders were compared with 24 demographically similar, healthy male controls using 3 personality instruments: the Millon Clinical Multiaxial Inventory-II, the Dimensional Assessment of Personality Impairment-Questionnaire, and the Temperament and Character Inventory. The data suggested that pedophiles have impaired interpersonal functioning, specifically, reduced assertiveness and elevated passive-aggressiveness, as well as impaired self-concept. Regarding disinhibitory traits, pedophiles demonstrated elevated sociopathy and propensity for cognitive distortions. Our data are consistent with previous reports of pathologic personality traits in pedophiles and lend support to a hypothesis that such pathology is related to both motivation for and failure to inhibit pedophilic behavior. Such information could potentially have important treatment implications.

AdVance male sling

PubMed Central

Chung, Amanda S. J.; Suarez, Oscar A.

2017-01-01

The AdVance sling (American Medical Systems, Minnetonka, MN, United States of America) is a synthetic transobturator sling, which is a safe and effective minimally invasive treatment for mild to moderate stress urinary incontinence (SUI) in male patients. This article provides a step-by-step description of our technique for placement of the AdVance male sling, including details and nuances gained from surgical experience, advice for avoidance of complications and discussion on management of complications and sling failures. Patient selection is very important, including exclusion and preoperative treatment of urethral stenosis and bladder dysfunction. Previous pelvic radiation is a poor prognostic factor. In brief, the steps of sling placement are: (I) mobilization of the corpus spongiosum (CS); (II) marking and mobilization of the central tendon; (III) passage of the helical trocar needles exiting at the apex of the angle between the CS and inferior pubic ramus; (IV) fixation of the broad part of the sling body to the CS at the previous mark; (V) cystoscopy during sling tensioning; (VI) placement of a Foley urethral catheter; (VII) Subcutaneous tunnelling of the sling arms back toward the midline; (VIII) wound closure. The most common early postoperative complication is urinary retention but long-term retention is extremely rare. Management of sling failures include placement of an artificial urinary sphincter, repeat AdVance sling, urethral bulking agent or ProACT device. PMID:28904900

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

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.

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)

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 ...

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.

Males collectively defend their one-male units against bachelor males in a multi-level primate society.

PubMed

Xiang, Zuo-Fu; Yang, Bang-He; Yu, Yang; Yao, Hui; Grueter, Cyril C; Garber, Paul A; Li, Ming

2014-07-01

Group-level male-male co-operation, which has been documented in several primate and non-primate societies, may be mutualistically advantageous to the participants when confronted with threats such as takeovers and cuckoldry by external males. Co-operation among members of distinct social units-while universal among humans-is extremely rare in non-human primates. We present the first observations of collective action or co-operation among males of different one-male units (OMU) in a multi-level society of Rhinopithecus roxellana. A total of 59 instances of male co-operation were recorded. Male co-operation included coordinated chasing, joint vigilance, and patrolling behavior directed at lone adult males trying to enter an OMU. Male co-operation was significantly more frequent during the mating season when the risk of incursions and extra-group paternity was higher. Paternity of infants born in the subsequent birth season and kin relationships among resident males were identified using microsatellite genotype. All infants were sired by OMU males, which we interpret as possible evidence for their success at thwarting mating attempts by satellite males. OMU males were principally unrelated suggesting that male co-operation is best understood in terms of the mutual direct benefits individuals obtain through collective action. Our findings lend support to the bachelor threat hypothesis in which the cooperative behavior of several individuals is more effective than the lone action of a single individual in providing mate defense. Our research has implications for understanding male bonding, higher-level collective action, and the evolution of social co-operation in human societies. © 2013 Wiley Periodicals, Inc.

Males adjust their signalling behaviour according to experience of male signals and male-female signal duets.

PubMed

Rebar, D; Rodríguez, R L

2016-04-01

Sexual signals are conspicuous sources of information about neighbouring competitors, and species in which males and females signal during pair formation provide various sources of public information to which individuals can adjust their behaviour. We performed two experiments with a duetting vibrational insect, Enchenopa binotata treehoppers (Hemiptera: Membracidae), to ask whether males adjust their signalling behaviour according to (1a) their own experience of competitors' signals, (1b) how females adjust their mate preferences on the basis of their experience of male signals (described in prior work), and/or (2) their own experience of female response signals to competitors' signals. We presented males with synthetic male signals of different frequencies and combinations thereof for 2 weeks. We recorded males a day after their last signal exposure, finding that (1a) male signal rate increased in response to experience of attractive competitors, but that (1b) male signal frequency did not shift in a manner consistent with how females adjust their mate preferences in those experience treatments. Second, we presented males with different male-female duets for 2 weeks, finding that (2) male signal length increased from experience of female duets with attractive competitors. Males thus make two types of adjustment according to two sources of public information: one provided by experience of male signals and another by experience of female responses to male signals. Signalling plasticity can generate feedback loops between the adjustments that males and females make, and we discuss the potential consequences of such feedback loops for the evolution of communication systems. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

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...

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…

Male reproductive health and yoga

PubMed Central

Sengupta, Pallav; Chaudhuri, Prasenjit; Bhattacharya, Koushik

2013-01-01

Now-a-days reproductive health problems along with infertility in male is very often observed. Various Assisted Reproductive Technologies have been introduced to solve the problem, but common people cannot afford the cost of such procedures. Various ayurvedic and other alternative medicines, along with regular yoga practice are proven to be not only effective to enhance the reproductive health in men to produce a successful pregnancy, but also to regulate sexual desire in men who practice celibacy. Yoga is reported to reduce stress and anxiety, improve autonomic functions by triggering neurohormonal mechanisms by the suppression of sympathetic activity, and even, today, several reports suggested regular yoga practice from childhood is beneficial for reproductive health. In this regard the present review is aimed to provide all the necessary information regarding the effectiveness of yoga practice to have a better reproductive health and to prevent infertility. PMID:23930026

Physiology of male sexual function.

PubMed

deGroat, W C; Booth, A M

1980-02-01

The male sexual response cycle consists of excitement, plateau, orgasm, and resolution. The initial event, penile erection, is produced by arteriolar dilatation and increased blood flow to the erectile tissue of the penis. Erection is a reflex response initiated by visual, olfactory, or imaginative stimuli impinging upon supraspinal centers or by genital stimulation that in turn activates spinal reflex mechanisms. Sacral parasympathetic and thoracolumbar sympathetic nerves provide the efferent vasodilator input to the penis. Parasympathetic nerves also stimulate secretion from the seminal vesicles and prostate and Cowper's glands during the plateau phase. The orgasmic phase is characterized by seminal emission and ejaculation and the accompanying sensations. Emission of semen into the urethra depends on sympathetic nerves that elicit contractions of smooth muscles in the vas deferens, seminal vesicles, and prostate. Rhythmic contractions of striated muscle (bulbocavernosus and ischiocavernosus) generated by efferent pathways in the pudendal nerve eject semen from the urethra.

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.

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

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

The Puzzle of Male Chronophilias.

PubMed

Seto, Michael C

2017-01-01

In this article, I return to the idea that pedophilia, a sexual interest in prepubescent children, can be considered a sexual orientation for age, in conjunction with the much more widely acknowledged and discussed sexual orientation for gender. Here, I broaden the scope to consider other chronophilias, referring to paraphilias for age/maturity categories other than young sexually mature adults. The puzzle of chronophilias includes questions about etiology and course, how chronophilias are related to each other, and what they can tell us about how human (male) sexuality is organized. In this article, I briefly review research on nepiophilia (infant/toddlers), pedophilia (prepubescent children), hebephilia (pubescent children), ephebophilia (postpubescent, sexually maturing adolescents), teleiophilia (young sexually mature adults, typically 20s and 30s), mesophilia (middle-aged adults, typically 40s and 50s), and gerontophilia (elderly adults, typically 60s and older) in the context of a multidimensional sexual orientations framework. Relevant research, limitations, and testable hypotheses for future work are identified.

The Rett syndrome in males.

PubMed

Philippart, M

1990-01-01

Two young males in their thirties are reported with a clinical history and examination indistinguishable from typical females with the Rett syndrome. Both had normal early development. The first patient had a regression by the end of the second year. He was late in walking, had prominent hand-wringing from the age of 4 years, and non-progressive dystonia from the age of 14 years. He is still ambulatory. Seizures which started at the age of 18 months have been easily controlled. The second patient has had a severe seizure disorder since the age of 7 months. In his early teens, he lost ambulation and his height and weight fell below the 2nd percentile. He has severe foot dystonia without spasticity. Both patients have a normal head size and no evidence of atrophy on a CT scan of the brain. Both had kyphoscoliosis in their teens. It is difficult to evaluate the incidence of such cases. Little attention being paid to the normal early development, they hide behind vague diagnoses such as cerebral palsy, static encephalopathy, and behavior disorder. Dystonia is often confused with spasticity, the lack of paralysis is not appreciated, apraxia and hand wringing are assumed to be self-stimulatory behaviors.

Male hypogonadism and metabolic syndrome.

PubMed

Naifar, M; Rekik, N; Messedi, M; Chaabouni, K; Lahiani, A; Turki, M; Abid, M; Ayedi, F; Jamoussi, K

2015-06-01

The role of androgens in cardiovascular disease is still controversial in men. In this study, we investigated metabolic disorders in Tunisian hypogonadal men compared with healthy controls. Forty hypogonadal men and 80 control subjects were enrolled. Patients with a history of pre-existing panhypopituitarism, thyroid dysfunction or inflammatory disease were excluded. Glycaemia, glycated haemoglobin (HbA1c), high-sensitive C-reactive protein (hsCRP), lipid profile, insulin, testosterone and gonadotrophins were measured. Insulin resistance was assessed by homoeostasis model assessment of insulin resistance (Homa IR). Waist circumference, body mass index and blood pressure were significantly higher in patients compared with controls. Glycemia, HbA1c, fasting serum insulin and Homa IR were significantly increased among hypogonadal men. In univariate analysis, testosterone levels were inversely correlated with body mass index, waist circumference, blood pressure, glycaemia, HbA1C, insulin, Homa IR and hsCRP. In multivariate analysis including all significant variables, initial testosterone level was the only independent risk factor for developing dyslipidaemia. With logistic regression, male hypogonadism was an independent risk factor for MS (P < 0.001). We conclude that low testosterone level plays a central role in the development of metabolic syndrome. Further prospective data are required to establish the causative link. © 2014 Blackwell Verlag GmbH.

Sexual Violence Among Male Inmates.

PubMed

Hilinski-Rosick, Carly M; Freiburger, Tina L

2018-04-01

Inmate misconduct has been a widely studied topic for many decades. General studies of misconduct have found that there are certain factors that contribute to misconduct, including age, gender, sentence length, and facility type. Few studies, however, have examined the factors predicting sexual offenses in a prison conduct. Although many studies of victims of sexual offenses in prison have been conducted, there is a lack of studies examining the perpetrators of prison sexual violence. The current study attempted to expand this body of literature by examining the correlates of sexual misconduct among a sample of male inmates incarcerated in the state of North Carolina during 2010. Deprivation and importation theories of inmate behavior were used to guide the analysis, and measures of deprivation and importation factors were both included in the analytical models. Findings indicate that Black, nonmarried, younger inmates, who had more previous incarcerations and had been incarcerated longer, had greater odds of having a sexual infraction. Additional findings, as well as policy implications, are discussed.

[Hormone regulation of male fertility].

PubMed

Anselmo, J G

1975-01-01

An innocuous, sure, reversible means of male fertility control which does not disturb the libido is being sought. 20 healthy volunteers from ages 20 to 36 participated, using a 2nd form of protection when necessary. 10 received implants of 60 mg testosterone equally divided into 3 tubes, and began oral ingestion of 100 mg weekly, divided into daily doses, of R2323 (13-ethyl-17-hydroxy-gonen 4,9,11, trien-3-one) until the sperm became ineffective. Then oral doses were given according to personal requirements from 50 to 25 mg. The 2nd series of 10 received no testosterone implants, but followed the same scheme for oral ingestion. All patients but 1 reduced their sperm count and 80% were low enough to consider the sperm inactive. For those who used the hormone treatment as the only protection against pregnancy, no pregnancy occurred. Of the 1st group, 2 had excessive weight gain, 3 felt their libido reduced, and 1 had pain in the nipples and 1 had pain in the hepatic region. Recuperation of normal sperm characteristics was slow, especially motility and vitality. The spermogram is so altered during treatment that any accidental pregnancy could result in a defective egg and serious complications. It should definitely be avoided.

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.

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.

Youth masculinities: compelling male heterosexuality.

PubMed

Richardson, Diane

2010-12-01

This article seeks to extend understandings of heterosexual masculine identities through an examination of young men's constructions of what motivates young men to engage in heterosexual practices and relationships, and what not having sex might mean for them. Using the masculinity literature and work on heterosexuality to frame the discussion and to contextualize the findings, it explores the complex dynamics that frame the relationship between masculinity and heterosexuality. Specifically, how dominant or 'hegemonic' discourses of heterosexuality shape young men's identities, beliefs and behaviour. It considers these questions using empirical data from a qualitative study of young people living in close-knit working-class communities in the North East of England, with a specific focus on cultural and social attitudes towards sexuality and sexual practices. Peer group networks are a key site for the construction and (re)production of masculinity and, therefore, an important arena within which gendered social approval and acceptance is both sought and gained. In this article, I explore the reasons why young men engage in specific types of heterosexual practice in order to gain social approval. A central question is the extent to which heterosexuality is compelling for young men. That young men do feel compelled to behave in certain ways sexually, behaviours that they may be uncomfortable with and/or dislike, and the fact that they feel they are restricted in terms of how they can talk about their experiences within their peer group networks, demonstrates the power of dominant discourses of masculinity in everyday life. This is addressed through an examination of the restrictive effects of normative discourses about male heterosexuality, including their privatizing effects, which suggest that youth masculinities are often experienced in ways that are highly contradictory requiring young men to adopt a range of strategies to deal with this.

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.

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

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

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.

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.

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.

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

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

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.

The Sexual Stereotype of the Black Male.

ERIC Educational Resources Information Center

Davis, Gary L.; Cross, Herbert J.

This paper presents the results of a study to examine the existence of sexual stereotyping of black males by white college students. Subjects were 180 male and 180 female white undergraduates; they were tested in sexually segregated groups. Each read one of three types of pornographic stories (hard-core, erotic realism, or sexual fantasy). The…

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.…

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…

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.

Adolescent Male Attitudes about Singing in Choir

ERIC Educational Resources Information Center

Lucas, Mark

2011-01-01

The purpose of this study was to investigate the factors that influence adolescent males to enroll in school choir as an elective class and to assess their attitudes about singing in general, self-concept of their own voices, and perception of others' view of adolescent males' participation in choir. Data were obtained from 101 adolescent males…

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…

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…

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.

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…

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…

[Mechanisms of electromagnetic radiation damaging male reproduction].

PubMed

Xue, Lei; Chen, Hao-Yu; Wang, Shui-Ming

2012-08-01

More and more evidence from over 50 years of researches on the effects of electromagnetic radiation on male reproduction show that a certain dose of electromagnetic radiation obviously damages male reproduction, particularly the structure and function of spermatogenic cells. The mechanisms of the injury may be associated with energy dysmetabolism, lipid peroxidation, abnormal expressions of apoptosis-related genes and proteins, and DNA damage.

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)

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 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…

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)

Communities for and with Black Male Students

ERIC Educational Resources Information Center

Jett, Christopher C.; Stinson, David W.; Williams, Brian A.

2015-01-01

The social and educational status of black male youth in the United States has been receiving increasing attention. In February 2014, President Barack Obama announced a new national initiative--My Brother's Keeper--for helping black boys and male youth or, to speak more generally, boys and young men of color, to "stay on track; providing the…

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…

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…

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.

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 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.…

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 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…

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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

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.

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.

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

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).

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.

Pictorial essay: Mammography of the male breast

PubMed Central

Popli, Manju Bala; Popli, V; Bahl, P; Solanki, Y

2009-01-01

Mammography is an imaging modality that is widely perceived to be of use only in women for the detection and diagnosis of breast pathologies. Here, we present a pictorial essay on the mammographic spectrum of male breast pathologies. PMID:19881102

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.

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.

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.

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

Reproductive physiology of the male camelid.

PubMed

Bravo, P W; Johnson, L W

1994-07-01

The physiology of reproduction with emphasis on endocrinology of llamas and alpacas is addressed. Information regarding male anatomy, puberty, testicular function, semen description, and sexual behavior is also included.

Aging changes in the male reproductive system

MedlinePlus

... 004017.htm Aging changes in the male reproductive system To use the sharing features on this page, ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

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.

Pharmacologic development of male hormonal contraceptive agents.

PubMed

Roth, M Y; Amory, J K

2011-01-01

The world population continues to increase dramatically despite the existence of contraceptive technology. The use of male hormonal contraception may help in preventing un intended pregnancies and managing future population growth. Male hormonal contraception relies on the administration of exogenous hormones to suppress spermatogenesis. Clinical trials have tested several regimens using testosterone, alone or in combination with a progestin. These regimens were shown to be >90% effective in preventing conception and were not associated with serious adverse events.

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.

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

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.

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 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.

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.

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

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.

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-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.

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.

Progesterone Impairs Social Recognition in Male Rats

PubMed Central

Auger, Catherine J.

2012-01-01

The influence of progesterone in the brain and on the behavior of females is fairly well understood. However, less is known about the effect of progesterone in the male system. In male rats, receptors for progesterone are present in virtually all vasopressin (AVP) immunoreactive cells in the bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA). This colocalization functions to regulate AVP expression, as progesterone and/or progestin receptors (PR)s suppresses AVP expression in these same extrahypothalamic regions in the brain. These data suggest that progesterone may influence AVP-dependant behavior. While AVP is implicated in numerous behavioral and physiological functions in rodents, AVP appears essential for social recognition of conspecifics. Therefore, we examined the effects of progesterone on social recognition. We report that progesterone plays an important role in modulating social recognition in the male brain, as progesterone treatment lead to a significant impairment of social recognition in male rats. Moreover, progesterone appears to act on PRs to impair social recognition, as progesterone impairment of social recognition is blocked by a PR antagonist, RU-486. Social recognition is also impaired by a specific progestin agonist, R5020. Interestingly, we show that progesterone does not interfere with either general memory or olfactory processes, suggesting that progesterone seems critically important to social recognition memory. These data provide strong evidence that physiological levels of progesterone can have an important impact on social behavior in male rats. PMID:22366506

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

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.

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.

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.

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.

[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.

Progesterone impairs social recognition in male rats.

PubMed

Bychowski, Meaghan E; Auger, Catherine J

2012-04-01

The influence of progesterone in the brain and on the behavior of females is fairly well understood. However, less is known about the effect of progesterone in the male system. In male rats, receptors for progesterone are present in virtually all vasopressin (AVP) immunoreactive cells in the bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA). This colocalization functions to regulate AVP expression, as progesterone and/or progestin receptors (PR)s suppress AVP expression in these same extrahypothalamic regions in the brain. These data suggest that progesterone may influence AVP-dependent behavior. While AVP is implicated in numerous behavioral and physiological functions in rodents, AVP appears essential for social recognition of conspecifics. Therefore, we examined the effects of progesterone on social recognition. We report that progesterone plays an important role in modulating social recognition in the male brain, as progesterone treatment leads to a significant impairment of social recognition in male rats. Moreover, progesterone appears to act on PRs to impair social recognition, as progesterone impairment of social recognition is blocked by a PR antagonist, RU-486. Social recognition is also impaired by a specific progestin agonist, R5020. Interestingly, we show that progesterone does not interfere with either general memory or olfactory processes, suggesting that progesterone seems critically important to social recognition memory. These data provide strong evidence that physiological levels of progesterone can have an important impact on social behavior in male rats. Copyright © 2012 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

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.

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

Sexual Homicide by Older Male Offenders.

PubMed

Myers, Wade C; Chan, Heng Choon Oliver; Mariano, Timothy Y; Safarik, Mark E; Geberth, Vernon J

2017-07-01

Recent research has expanded our understanding of sexual homicide offenders (SHOs). However, little exists beyond case reports for older SHOs. We characterized male SHOs ≥ 55 years, comparing them to typical adult male SHOs who are in their 20s. Analysis of 37 years (1976-2012) of US Supplementary Homicide Reports data provided a large SHO sample (N = 3453). Three case reports provide clinical context for the diverse nature and patterns of older SHOs. Only 32 older male SHOs and no older female SHOs were identified. Murders by older SHOs accounted for only 0.5% of US sexual homicides. Unlike typical SHOs that generally target young adult females, over two-thirds of older SHO victims were ≥40 years, and one-third were ≥55 years. Sexual homicides by older SHOs, like sexual homicide in general, decreased over the study period. These crimes, while exceedingly rare, do occur, warranting special consideration. © 2017 American Academy of Forensic Sciences.

[Astaxanthin in male reproduction: Advances in studies].

PubMed

Liu, Wei; Kang, Xiao-Fang; Shang, Xue-Jun

2016-10-01

Astaxanthin (AST) is a carotenoid with a strong antioxidant activity and has many biological functions, such as anti-inflammation, immune regulation, anti-tumor, anti-oxidation, anti-aging, and anti-apoptosis. Recent studies show that AST can effectively regulate the dynamic balance between oxidation and antioxidants in the male reproductive system, protect sperm mitochondrial function, ameliorate testicular heat stress and reproductive poison damage, promote the occurrence of sperm capacitation and acrosome reaction, regulate reproductive endocrine hormone balance, and act favorably on primary infertility or metabolic syndrome-related infertility. It also helps the treatment of late-onset hypogonadism and prostate health care. This review updates the studies of AST in male reproductive health and provides some new ideas for the prevention and treatment of male reproductive problems.

Interventional Radiology of Male Varicocele: Current Status

SciTech Connect

Iaccarino, Vittorio, E-mail: vittorio.iaccarino@unina.it; Venetucci, Pietro

2012-12-15

Varicocele is a fairly common condition in male individuals. Although a minor disease, it may cause infertility and testicular pain. Consequently, it has high health and social impact. Here we review the current status of interventional radiology of male varicocele. We describe the radiological anatomy of gonadal veins and the clinical aspects of male varicocele, particularly the physical examination, which includes a new clinical and ultrasound Doppler maneuver. The surgical and radiological treatment options are also described with the focus on retrograde and antegrade sclerotherapy, together with our long experience with these procedures. Last, we compare the outcomes, recurrence andmore » persistence rates, complications, procedure time and cost-effectiveness of each method. It clearly emerges from this analysis that there is a need for randomized multicentre trials designed to compare the various surgical and percutaneous techniques, all of which are aimed at occlusion of the anterior pampiniform plexus.« less

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.

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.

[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.

Systemic lupus erythematosus in a male patient

NASA Astrophysics Data System (ADS)

Sibarani, H.; Zubir, Z.

2018-03-01

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder with a broad spectrum of clinical presentations. Female to male ratio is approximately 9:1.A 20 years old male was admitted to HAM Hospital 3 months ago with chief complaint pain in both knees joint. After anamneses, physical examination and laboratory test the patient was diagnosed with systemic lupus erythematosus. The patient tested positive for ANA and anti-ds-DNA antibody test. The patient was with giving non-biologic DMARDS @myfortic 360mg, methylprednisolone, chloroquine and other symptomatic drugs.

Clinical trials in male hormonal contraception.

PubMed

Nieschlag, Eberhard

2010-11-01

Research has established the principle of hormonal male contraception based on suppression of gonadotropins and spermatogenesis. All hormonal male contraceptives use testosterone, but only in East Asian men can testosterone alone suppress spermatogenesis to a level compatible with contraceptive protection. In Caucasians, additional agents are required of which progestins are favored. Clinical trials concentrate on testosterone combined with norethisterone, desogestrel, etonogestrel or depot-medroxyprogesterone acetate. The first randomized, placebo-controlled clinical trial performed by the pharmaceutical industry demonstrated the effectiveness of a combination of testosterone undecanoate and etonogestrel in suppressing spermatogenesis in volunteers. Copyright © 2010 Elsevier Inc. All rights reserved.

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

Brain activation during human male ejaculation revisited.

PubMed

Georgiadis, Janniko R; Reinders, A A T Simone; Van der Graaf, Ferdinand H C E; Paans, Anne M J; Kortekaas, Rudie

2007-04-16

In a prior [O]-H2O positron emission tomographic study we reported brain regions involved in human male ejaculation. Here, we used another, more recently acquired data set to evaluate the methodological approach of this previous study, and discovered that part of the reported activation pattern was not related to ejaculation. With a new analysis of these ejaculation data, we now demonstrate ejaculation-related activations in the deep cerebellar nuclei (dentate nucleus), anterior vermis, pons, and ventrolateral thalamus, and, most importantly, ejaculation-related deactivations throughout the prefrontal cortex. This revision offers a new and more accurate insight into the brain regions involved in human male ejaculation.

Breast Abscess Mimicking Breast Carcinoma in Male.

PubMed

Gochhait, Debasis; Dehuri, Priyadarshini; Umamahesweran, Sandyya; Kamat, Rohan

2018-01-01

Male breast can show almost all pathological entities described in female breast. Inflammatory conditions of the breast in male are not common; however, occasionally, it can be encountered in the form of an abscess. Clinically, gynecomastia always presents as a symmetric unilateral or bilateral lump in the retroareolar region, and any irregular asymmetric lump raises a possibility of malignancy. Radiology should be used as a part of the triple assessment protocol for breast lump along with fine-needle aspiration cytology for definite diagnosis and proper management.

Vulnerable discipline: experiences of male competitive bodybuilders.

PubMed

Bjørnestad, Jone; Kandal, Øyvind; Anderssen, Norman

2014-09-01

The aim was to understand experiences of male competitive bodybuilders from a non-pathologizing perspective. Six male Norwegian competitive bodybuilders were interviewed. The interviews were analysed using a meaning condensation procedure resulting in five themes: being proud of capacity for discipline, seeing a perfectionist attitude as a necessary evil, experiencing recognition within the bodybuilding community, being stigmatized outside the bodybuilding community and going on stage to display a capacity for willpower and discipline. We suggest that bodybuilders may be stigmatized for breaking social norms: by their distinctive appearance, by the way they handle suspected drug use and by challenging gender norms. © The Author(s) 2013.

Alienation of sexuality in male erotic dancing.

PubMed

Boden, David M

2007-01-01

This ethnographic study investigates a male-for-male gender arrangement of erotic dancing. Analysis of the data suggests that the men in this occupation understand their labor as titillation, a pleasurable erotic flirtation, for the entertainment of the consumer. Central to the performance is a constructed sexuality that is not reflective of the desires of the dancer but, rather, those of the consumer. The alienation of the dancer from his sexuality may result in behaviors and encounters that violate his normative and moral expectations.

Infective factors of male infertility among Nigerians.

PubMed

Ogunbanjo, B O; Osoba, A O; Ochei, J

1989-03-01

Seminal fluid from 782 Nigerian males with complaints of infertility were examined with respect to infective agents and indices such as sperm count, motility and the presence of a significant number of pus cells. Various infective agents were recovered from 54 (7%) of the patients, while in 25% of the remaining patients, a significant number of pus cells was present, with associated abnormal seminal fluid indices. Our findings indicate that seminal fluids constitute an important medium for the spread of various infective agents, and that genital infections by these infective agents, sexually and non-sexually transmitted, may be responsible for a good percentage of infertility cases in Nigerian males.

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 ...

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…

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…

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…

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)

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…

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…

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…

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.

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…

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).

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…

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.

MMPI Profiles of Males with Abnormal Sex Chromosome Complements

ERIC Educational Resources Information Center

Rosen, M.; And Others

1971-01-01

Nine males with Klinefelter's syndrome (XXY) and seven XYY males, located primarily in prisons and psychiatric hospitals, were administered the Minnesota Multiphasic Personality Inventory. (Author/KW)

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

Sex Steroid Actions in Male Bone

PubMed Central

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

2014-01-01

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

Tenure's Impact: Male versus Female Viewpoints

ERIC Educational Resources Information Center

Premeaux, Shane R.; Mondy, R. Wayne

2002-01-01

The attitudes of male and female university professors at AACSB (The Association to Advance Collegiate Schools of Business) International accredited business schools differ substantially regarding certain aspects of traditional tenure. This survey of 1,306 professors at 307 AACSB International accredited schools in 48 states and Canada examines a…

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.

Exploring the Spiritual Lives of Adolescent Males

ERIC Educational Resources Information Center

Bynum, Kai

2016-01-01

This study explores how adolescent males in secular boys' schools perceive spirituality and how these perceptions relate to their emotional intelligence. I examined the relationship between spirituality and emotion by inviting the boys to reflect on how the two impact their lives, relationships, and behaviors. My study was designed to provide the…

Still so Few Male Teachers: Now What?

ERIC Educational Resources Information Center

Johnson, Shaun Patrick

2010-01-01

A shortage of male teachers at all levels of public education is not a new phenomenon. Gender disparities in teaching have been around for more than a century in the United States. While roughly 39 percent of all elementary and secondary public school teachers were men as early as 1869, only 29 percent of teachers were men by the turn of the…

Nonparticipatory Stiffness in the Male Perioral Complex

ERIC Educational Resources Information Center

Chu, Shin-Ying; Barlow, Steven M.; Lee, Jaehoon

2009-01-01

Purpose: The objective of this study was to extend previous published findings in the authors' laboratory using a new automated technology to quantitatively characterize nonparticipatory perioral stiffness in healthy male adults. Method: Quantitative measures of perioral stiffness were sampled during a nonparticipatory task using a…

Update on the male hormonal contraceptive agents.

PubMed

Walton, Melanie; Anderson, Richard A

2004-09-01

There remains a need for new acceptable and effective male contraceptives to increase the choice for couples throughout the world. There have been no recent advances in available male contraceptive methods although a number of promising approaches have been identified, of which the hormonal approach is currently undergoing clinical investigation. In recent years the pace of research in this area has quickened significantly with increasing interest and now investment by the pharmaceutical industry. This is vital if the work undertaken so far by the public sector is to be transformed into a commercial reality. The hormonal approach is based on suppression of pituitary gonadotropin secretion resulting in a reversible reduction in spermatogenesis with azoospermia in all men being the ultimate aim. Without stimulation by luteinising hormone from the pituitary, testicular testosterone production also ceases. Therefore, androgen administration to restore physiological levels is an essential component of all male hormonal contraceptive regimes. Male hormonal contraceptives can consist of testosterone alone, or either a progestogen or gonadotropin-releasing hormone antagonist with 'add-back' testosterone. This article reviews the current state of progress in this field.

Restoring Self-Esteem in Adolescent Males

ERIC Educational Resources Information Center

Hendel, Andrea

2006-01-01

When presented with the words self-esteem, it is most common in our society to immediately think of girls. It is not often that people ponder the effects of body image, athleticism, success, or even friendships for boys. Unfortunately in overlooking these concepts, we are doing a disservice to our male youth. This article addresses the effects of…

Studying Adolescent Male Sexuality: Where Are We?

ERIC Educational Resources Information Center

Smith, Laureen H.; Guthrie, Barbara J.; Oakley, Deborah J.

2005-01-01

This article critically reviews the literature about adolescent males' sexuality in order to describe the state of the science and to identify promising concepts and research designs that have the potential to guide the next generation of research. A critique was conducted on 94 peer-reviewed studies of sexual behaviors that included a sample of…

Suspect osteogenesis imperfecta in a male kitten

PubMed Central

Evason, Michelle D.; Taylor, Susan M.; Bebchuk, Trevor N.

2007-01-01

A 4.5-month-old, male domestic shorthair was presented with bilateral femoral fractures after falling from a low height. Radiographs revealed reduced radio-opacity and thin cortices of all long bones. A presumptive diagnosis of osteodystrophy, secondary to osteogenesis imperfecta, was made on postmortem examination. PMID:17436908

Causes of Male Dropout Rate in Pakistan

ERIC Educational Resources Information Center

Ud Din, Muhammad Naseer; Dad, Hukam; Iqbal, Javid; Shah, Syed Shafqat Ali; Niazi, Muhammad Imran

2011-01-01

This study aimed to seek the cause of male students' dropout rate at the primary level of F.R. Peshawar. The main objectives of the study were: 1) to study the teacher problems and attitudes of the dropouts, 2) to determine the factors that cause dropouts, 3) to study the government's strategy of dropouts, and 4) to provide suggestions to overcome…

Queer Decisions? Gay Male Students' University Choices

ERIC Educational Resources Information Center

Taulke-Johnson, Richard

2010-01-01

This article examines the reported influences on the university choices of 17 gay male undergraduate students attending a UK institution. It is argued that this process is strongly mediated by, and, therefore, has to be considered in relation to, class. Data analysis provides insight into the factors gay students say are important in selecting…

Health Problems and Male Firearm Suicide

ERIC Educational Resources Information Center

Hempstead, Katherine; Nguyen, Tuan; David-Rus, Richard; Jacquemin, Bretta

2013-01-01

Drawing on constructs of masculinity as it relates to both gun ownership and men's health, we use a rich data set, the New Jersey Violent Death Reporting System as well as hospital discharge data, to analyze 3,413 completed male suicides between the years of 2003 and 2009. We test the hypotheses that the use of firearms is more common when…

Interpersonal polyvictimization and mental health in males.

PubMed

Burns, Carol Rhonda; Lagdon, Susan; Boyda, David; Armour, Cherie

2016-05-01

A consistent conclusion within the extant literature is that victimization and in particular polyvictimization leads to adverse mental health outcomes. A large body of literature exists as it pertains to the association between victimisation and mental health in studies utilising samples of childhood victims, female only victims, and samples of male and female victims; less research exists as it relates to males victims of interpersonal violence. The aim of the current study was therefore to identify profiles of interpersonal victimizations in an exclusively male sample and to assess their differential impact on a number of adverse mental health outcomes. Using data from 14,477 adult males from Wave 2 of the NESARC, we identified interpersonal victimization profiles via Latent Class Analysis. Multinomial Logistic Regression was subsequently utilized to establish risk across mental health disorders. A 4-class solution was optimal. Victimisation profiles showed elevated odds ratios for the presence of mental health disorders; suggesting that multiple life-course victimisation typologies exists, and that victimization is strongly associated with psychopathology. Several additional notable findings are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Crossing Uncertain Terrain: Messages from Male Academics

ERIC Educational Resources Information Center

Keamy, Ron Kim

2008-01-01

In this paper, comments made by a group of senior male academics in Australian universities about their leadership behaviours, are considered. Whereas the majority of the men in the study spoke about gender relations, and sometimes feminism in their workplaces, only two of the men engaged in discourses of gender and/or feminism, as well as…

The Cultural Bind on the American Male

ERIC Educational Resources Information Center

Chenoweth, Gene

2012-01-01

In this article, the author talks about the cultural bind on the American male. The process starts with conception. If the spermatozoid that fertilizes the egg contains only X chromosomes a girl will be produced. If a single Y chromosome out of the 24 produced by the father is included, the baby will be a boy. From this point on the girls have a…

Legalization of Employment Discrimination against White Males.

ERIC Educational Resources Information Center

Fontham, Michael R.

1978-01-01

The intervention of government to require speeial treatment of designated groups on the basis of race, color, or sex is inconsistent with principles of equal treatment under American law. Regardless of past discrimination against certain classes, governmental determination to favor them at the expense of White males is not justified. (Author/WI)

Male Teachers' Experiences of Own Aggression

ERIC Educational Resources Information Center

Botha, Johan; Myburgh, Chris; Poggenpoel, Marie

2013-01-01

We describe an exploratory, descriptive, and contextual study on the lived experiences of 17 male teachers' own aggression in the Gert Sibande district in Mpumalanga province. Individual phenomenological interviews were used to collect data from these volunteers for this qualitative research. The data were analysed by means of an open coding…

Stress and Identity among Black Males.

ERIC Educational Resources Information Center

Stokes, DeVon R.

Twenty Black American males' reactions to slides depicting interracial climate and/or racial oppression were investigated by recording physiological responses, specifically, galvanic skin potential (GSP) and heart rate (HR). Participants were also given the Myers/Stokes Identity Scale (MSIS) to ascertain their reaction to oppression and, based on…

Orthodontic treatment need in Asian adult males.

PubMed

Soh, Jen; Sandham, Andrew

2004-12-01

Orthodontic treatment in adults has gained social and professional acceptance in recent years. An assessment of orthodontic treatment need helps to identify individuals who will benefit from treatment and safeguard their interest. The purpose of this study was to assess the objective and subjective levels of orthodontic treatment need in a sample of orthodontically untreated adult Asian males. A sample of male army recruits (n = 339, age 17-22 years, Chinese = 258, Malay = 60, Indian = 21) with no history of orthodontic treatment or craniofacial anomalies participated in the study on a voluntary basis with informed consent. Impressions for study models were taken. Objective treatment need was assessed based on study model analysis using the Index of Orthodontic Treatment Need (IOTN). Questionnaires were used to assess subjective treatment need based on subjective esthetic component (EC) ratings. Fifty percentage of the sample had a definite need for orthodontic treatment (dental health component [DHC] grades 4 and 5), whereas 29.2% had a moderate need for treatment (DHC grades 3). The occlusal trait most commonly identified was dental crossbite. Malay males had the highest percentage with a definite need for treatment for both dental health and esthetic reasons in comparison with Chinese and Indian males. However, there was no difference in the level of treatment need among the ethnic groups (P > .05). No correlation between objective and subjective EC scores was found (P > .05). A high level of investigator-identified treatment need was not supported by a similar level of subject awareness among the adult sample.

Estimation of temporary emigration in male toads

USGS Publications Warehouse

Muths, E.; Scherer, R. D.; Corn, P.S.; Lambert, B.A.

2006-01-01

Male boreal toads (Bufo boreas) are thought to return to the breeding site every year but, if absent in a particular year, will be more likely to return the following year. Using Pollock's robust design we estimated temporary emigration (the probability a male toad is absent from a breeding site in a given year) at three locations in Colorado, USA: two in Rocky Mountain National Park and one in Chaffee County. We present data that suggest that not all male toads return to the breeding site every year. Our analyses indicate that temporary emigration varies by site and time (for example, from 1992 to 1998, the probability of temporary emigration ranged from 10% to 29% and from 3% to 95% at Lost Lake and Kettle Tarn, respectively). Although the results provide weak evidence that males are more likely to return after a year's hiatus, a general pattern of state-dependent temporary emigration was not supported. We also hypothesized relationships between temporary emigration and a number of weather variables. While some competitive models included weather covariates, imprecise and variable estimates of the effects of these covariates precluded fully defining their impact on temporary emigration. ?? 2006 by the Ecological Society of America.

Male Psychopaths and Their Criminal Careers.

ERIC Educational Resources Information Center

Hare, Robert D.; And Others

1988-01-01

Examined criminal histories of male psychopaths and nonpsychopaths, exploring time in prison and conviction rates for five-year periods between ages of 16 and 45. Criminal activities of nonpsychopaths were relatively constant over years; activities of psychopaths remained high until around age 40, then declined dramatically. Results are consistent…

Classroom Techniques for Black Male Student Retention.

ERIC Educational Resources Information Center

Gardenhire, John Fouts

This paper describes and encourages the application of 20 classroom techniques to enhance the retention and success of black male college students. Though retention enhancement programs work best when institution-wide support and commitment are behind them, the techniques described here can be implemented in the classroom with significant results…

Male sexuality in theory and practice.

PubMed

Kelly, Daniel

2004-06-01

Male sexuality is a complex phenomenon shaped by personal, cultural,and social factors. This article has argued that male sexual function is an important consideration in conditions such as prostate cancer. There are surely other conditions where it is understood even more poorly. Although theorists tend to explore male sexuality in relation to vague concepts such as power, phallocentrism, and aggression, sexuality becomes a personal reality in illness contexts. Using insights from a study into prostate cancer, it has been suggested that men assess embodied risks, such as impotence, in highly individual ways. The uncertainty that characterizes this cancer further compounds the difficulties involved, despite attempts of professionals to provide adequate levels of information and support. Researchers and practitioners alike should begin to question the gap between theoretical constructions of male sexuality and its reality in healthcare situations. More attention should be paid to understanding the importance of sexual function for men who are living with conditions such as prostate cancer. Those men who face up to the threat of such embodied changes, and who learn to cope with physical and emotional (and sexual) vulnerability, may learn to evaluate their lives in new ways. As Kenneth, one of the participants in this study said of his experience of cancer, "It just seems unnecessary for them to have to go through that to learn and understand themselves and be honest with themselves about what is really important."

Social Stress and Mortality Among Nonwhite Males

ERIC Educational Resources Information Center

Dennis, Ruth E.

1977-01-01

The leading causes of death for young black males are accidents, homicide and suicide. Stress arising from socioeconomic conditions precipitates these events. Heart disease and cancer, other major causes of death, are also thought to be environmentally related. The author proposes the development of new types of social institutions to remedy the…

Learning from Black Male Teachers Who Thrive

ERIC Educational Resources Information Center

El-Mekki, Sharif

2018-01-01

For many reasons, it's crucial to bring more black men into the U.S. teaching workforce. The author's group--The Fellowship: Black Male Educators for Social Justice--works toward that end in Philadelphia. Four teacher leaders from The Fellowship share their stories of what drew them into teaching.

Male reproductive health and environmental xenoestrogens.

PubMed Central

Toppari, J; Larsen, J C; Christiansen, P; Giwercman, A; Grandjean, P; Guillette, L J; Jégou, B; Jensen, T K; Jouannet, P; Keiding, N; Leffers, H; McLachlan, J A; Meyer, O; Müller, J; Rajpert-De Meyts, E; Scheike, T; Sharpe, R; Sumpter, J; Skakkebaek, N E

1996-01-01

Male reproductive health has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality has been reported from Belgium, Denmark, France, and Great Britain. The incidence of testicular cancer has increased during the same time incidences of hypospadias and cryptorchidism also appear to be increasing. Similar reproductive problems occur in many wildlife species. There are marked geographic differences in the prevalence of male reproductive disorders. While the reasons for these differences are currently unknown, both clinical and laboratory research suggest that the adverse changes may be inter-related and have a common origin in fetal life or childhood. Exposure of the male fetus to supranormal levels of estrogens, such as diethlylstilbestrol, can result in the above-mentioned reproductive defects. The growing number of reports demonstrating that common environmental contaminants and natural factors possess estrogenic activity presents the working hypothesis that the adverse trends in male reproductive health may be, at least in part, associated with exposure to estrogenic or other hormonally active (e.g., antiandrogenic) environmental chemicals during fetal and childhood development. An extensive research program is needed to understand the extent of the problem, its underlying etiology, and the development of a strategy for prevention and intervention. Images Figure 3. A Figure 3. B Figure 3. C Figure 3. D Figure 3. E Figure 3. F PMID:8880001

Male Adolescent Bullying and the School Shooter

ERIC Educational Resources Information Center

Reuter-Rice, Karin

2008-01-01

An extensive review of the literature reveals that adolescent male victims of peer bullying suffer somatic and emotional consequences from being victimized. Limited research on school shooters found that a significant number of them were adolescents who were targets of bullies and claimed their shootings were in response to their victimization. To…

Stressors Affecting the Male Divorced Client.

ERIC Educational Resources Information Center

Krick, Robert L.; And Others

A literature review of the Educational Resources and Information Center (ERIC), Psychological Abstracts, and Dissertation Abstracts International was conducted to examine research data and observations concerning the problems faced by males during and after divorce. Based on a scheme of divorce elements developed by Bohannon (1970) these problems…

A Global Overview of Male Escort Websites.

PubMed

Kumar, Navin; Minichiello, Victor; Scott, John; Harrington, Taylor

2017-01-01

This article details a preliminary dataset of global male escort sites to give insight into the scale of the online market. We conducted a content analysis of 499 Web sites and also measured traffic to these sites. Our analysis examined the structural characteristics of escort services, geographical and regulatory contexts, and resilience of such services. Results suggest that most sites are independent and not affiliated to escort agencies, and the majority cater to male escorts soliciting male clients, with a number of sites for female clientele and couples. These Web sites are dispersed globally, with Asian, European, and South American countries the major hubs in the market and a small number of large multinational sites based in the United States and Europe figuring as a major presence in markets. Although still subject to high levels of regulation in many parts of the world, the data suggest that male escorting is becoming more visible in diverse cultural contexts as measured by the number of Web sites appearing in public spaces.

Male-Female Differences in Formal Thought.

ERIC Educational Resources Information Center

Linn, Marcia C.

Two studies were conducted to clarify the influence of experiences and aptitudes on male-female differences in formal thought. Participants were 788 seventh-, ninth-, and eleventh-graders in three school districts differing in location, socioeconomic composition, and course offerings. Formal thought was measured with tasks involving proportional…

Male Students' Separate Education

ERIC Educational Resources Information Center

Sheymardanov, Shamil

2018-01-01

The paper deals with application of separate education theory as a factor contributing to the increase in the level of the male students' training. The topicality of the paper is concluded in the fact that in the modern society the pedagogical concept of separate education is considered to be outdated. Alongside with that, some experiments in…

ATRAZINE ALTERS STEROIDOGENESIS IN MALE WISTAR RATS

EPA Science Inventory

We have reported that atrazine (ATR, 200 mg/kg x 30 d) causes increased serum estrone (E) and estradiol (E2) in male wistar rats (Toxicol. Sci. 2000, 58:50-59). This study evaluates the short-term effects of ATR on E, E2 and their precursors in the steroidogenic pathway. Sixty-da...

Male Rape Victim and Perpetrator Blaming

ERIC Educational Resources Information Center

Sleath, Emma; Bull, Ray

2010-01-01

One of four possible vignettes manipulated by (a) level of rape myth contained within them (low vs. high) and (b) type of rape (stranger vs. acquaintance) was presented to participants followed by scales measuring victim blame, perpetrator blame, belief in a just world, sex-role egalitarian beliefs, and male rape myth acceptance. Victim blaming…

The osteoporotic male: Overlooked and undermanaged?

PubMed Central

Madeo, Bruno; Zirilli, Lucia; Caffagni, Giovanni; Diazzi, Chiara; Sanguanini, Alessia; Pignatti, Elisa; Carani, Cesare; Rochira, Vincenzo

2007-01-01

Age-related bone loss in men is a poorly understood phenomenon, although increasing data on the pathophysiology of bone in men is becoming available. Most of what we know on bone pathophysiology derives from studies on women. The well-known association between menopause and osteoporosis is far from been disproven. However, male osteoporosis is a relatively new phenomenon. Its novelty is in part compensated for by the number of studies on female osteoporosis and bone pathophysiology. On the other hand, the deeper understanding of female osteoporosis could lead to an underestimation of this condition in the male counterpart. The longer life-span exposes a number of men to the risk of mild-to-severe hypogonadism which in turn we know to be one of the pathogenetic steps toward the loss of bone mineral content in men and in women. Hypogonadism might therefore be one among many corrigible risk factors such as cigarette smoking and alcohol abuse against which clinicians should act in order to prevent osteoporosis and its complications. Treatments with calcium plus vitamin D and bisphophonates are widely used in men, when osteoporosis is documented and hypogonadism has been excluded. The poor knowledge on male osteoporosis accounts for the lack of well shared protocols for the clinical management of the disease. This review focuses on the clinical approach and treatment strategy for osteoporosis in men with particular attention to its relationship with male hypogonadism. PMID:18044181

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

African American Males: Leaving the Nightmare.

ERIC Educational Resources Information Center

Gill, Wali

The plight of African American males has become a problem of alarming proportions in the United States. This paper reports serious disadvantage and risk for this group in terms of education, employment, poverty levels, family disintegration, criminal status, health, and death rates. The paper contends that the crisis for African American males…

Brief Report: Trichotillomania in an Autistic Male.

ERIC Educational Resources Information Center

Hamdan-Allen, Ghada

1991-01-01

This report describes trichotillomania (the irresistible urge to pull one's own body hair) in a young male with autism who was treated successfully with Fluoxetine, a serotonergic antidepressant. The possible etiologic interrelations and treatment implications of this kind of comorbidity are presented. (JDD)

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.

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

Coffee consumption and periodontal disease in males.

PubMed

Ng, Nathan; Kaye, Elizabeth Krall; Garcia, Raul I

2014-08-01

Coffee is a major dietary source of antioxidants as well as of other anti-inflammatory factors. Given the beneficial role of such factors in periodontal disease, whether coffee intake is associated with periodontal disease in adult males was explored. Existing data collected by a prospective, closed-panel cohort study of aging and oral health in adult males was used. Participants included the 1,152 dentate males in the Veterans Affairs (VA) Dental Longitudinal Study who presented for comprehensive medical and dental examinations from 1968 to 1998. Mean age at baseline was 48 years; males were followed for up to 30 years. Participants are not VA patients; rather, they receive their medical and dental care in the private sector. Periodontal status was assessed by probing depth (PD), bleeding on probing, and radiographic alveolar bone loss (ABL), measured on intraoral periapical radiographs with a modified Schei ruler method. Moderate-to-severe periodontal disease was defined as cumulative numbers of teeth exhibiting PD ≥4 mm or ABL ≥40%. Coffee intake was obtained from participant self-reports using the Cornell Medical Index and food frequency questionnaires. Multivariate repeated-measures generalized linear models estimated mean number of teeth with moderate-to-severe disease at each examination by coffee intake level. It was found that higher coffee consumption was associated with a small but significant reduction in number of teeth with periodontal bone loss. No evidence was found that coffee consumption was harmful to periodontal health. Coffee consumption may be protective against periodontal bone loss in adult males.

The visual system of male scale insects

NASA Astrophysics Data System (ADS)

Buschbeck, Elke K.; Hauser, Martin

2009-03-01

Animal eyes generally fall into two categories: (1) their photoreceptive array is convex, as is typical for camera eyes, including the human eye, or (2) their photoreceptive array is concave, as is typical for the compound eye of insects. There are a few rare examples of the latter eye type having secondarily evolved into the former one. When viewed in a phylogenetic framework, the head morphology of a variety of male scale insects suggests that this group could be one such example. In the Margarodidae (Hemiptera, Coccoidea), males have been described as having compound eyes, while males of some more derived groups only have two single-chamber eyes on each side of the head. Those eyes are situated in the place occupied by the compound eye of other insects. Since male scale insects tend to be rare, little is known about how their visual systems are organized, and what anatomical traits are associated with this evolutionary transition. In adult male Margarodidae, one single-chamber eye (stemmateran ocellus) is present in addition to a compound eye-like region. Our histological investigation reveals that the stemmateran ocellus has an extended retina which is formed by concrete clusters of receptor cells that connect to its own first-order neuropil. In addition, we find that the ommatidia of the compound eyes also share several anatomical characteristics with simple camera eyes. These include shallow units with extended retinas, each of which is connected by its own small nerve to the lamina. These anatomical changes suggest that the margarodid compound eye represents a transitional form to the giant unicornal eyes that have been described in more derived species.

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.

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

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.

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.

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.

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).

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

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.

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.

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…

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...

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…

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…

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.…

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 ...

Male contraceptive research steps back into spotlight.

PubMed

Bonn, D

1999-01-23

The goal of male hormonal contraception is to block spermatogenesis by suppressing the secretion of pituitary gonadotropins. Prospects are good for the development of such a male contraceptive, with at least one hormonal contraceptive for men potentially available within 5-7 years. Finding an acceptable, reversible, and preferably long-lasting hormonal contraceptive for men is a top priority of the World Health Organization (WHO). Considerable evidence suggests that an androgen, with or without a progestogen, can provide effective contraception and is well tolerated. Schering and Organon are planning to collaborate with WHO in developing hormonal contraception for men. Fred Wu of the University of Manchester, UK, will soon begin a trial comparing the effectiveness of new injectable testosterone undecanoate and testosterone buciclate formulations, with or without synthetic progestogens.

Role of complimentary therapy for male LUTS.

PubMed

Cheetham, Philippa J

2013-12-01

Phytotherapy, the use of plant based extracts (derived from fruits, seeds, roots, or bark) as medicines or health-promoting agents are often used as first-line treatments for bothersome male lower urinary tract symptoms (LUTS). Their use, either as monotherapy or in conjunction with conventional pharmaceutical treatments is becoming increasingly popular worldwide. There are now over 30 of these phytotherapeutic compounds available, with saw palmetto and pygeum being the most widely used. This paper discusses the mechanism of action, reported efficacies and potential side effects of a number of the most common phytotherapies being used for male LUTS, as well as summarizes outcome data relevant to these agents from the most current peer-reviewed publications.

Predictors of Disordered Eating in Young Males.

PubMed

Doumit, R; Abi Kharma, J; Sanchez-Ruiz, M J; Zeeni, N

2018-02-01

Recent findings suggest that disordered eating (DE) symptomatology may be underestimated in the male population. The present study examined depressive symptomatology as a potential mediator of the relationships between body image dissatisfaction, strategies to change body weight and muscles, media pressure, and DE (emotional, restrained and emotional eating) in 260 male undergraduates who completed a self-reported questionnaire. Path analyses indicated that media influence and strategies to decrease body weight had direct positive effects on depressive symptomatology, which in turn predicted emotional eating. Media influence had a direct positive effect on emotional eating, whereas strategies to decrease body weight did not exhibit a direct effect on emotional eating. Therefore, the latter pathway was removed from the model. The link between media pressure, strategies to decrease body weight and emotional eating was partially mediated by depressive symptomatology. The present findings can inform the development and implementation of prevention and education programs for DE in schools and universities.

Acoustic passaggio pedagogy for the male voice.

PubMed

Bozeman, Kenneth Wood

2013-07-01

Awareness of interactions between the lower harmonics of the voice source and the first formant of the vocal tract, and of the passive vowel modifications that accompany them, can assist in working out a smooth transition through the passaggio of the male voice. A stable vocal tract length establishes the general location of all formants, including the higher formants that form the singer's formant cluster. Untrained males instinctively shorten the tube to preserve the strong F1/H2 acoustic coupling of voce aperta, resulting in 'yell' timbre. If tube length and shape are kept stable during pitch ascent, the yell can be avoided by allowing the second harmonic to rise above the first formant, creating the balanced timbre of voce chiusa.

[Male Urinary Incontinence--a Taboo Issue].

PubMed

Kozomara-Hocke, Marko; Hermanns, Thomas; Poyet, Cédric

2016-03-02

Male urinary incontinence is an underestimated and frequently not broached issue. The urinary incontinence is divided into stress-, urge incontinence and hybrid forms as well as overflow incontinence. The fact that there are increasingly more men over 60 means that the prevalence of the urinary incontinence is up to 40%, and urinary incontinence will increasingly gain importance in daily routine practice. Many investigations and therapies can be realized by the general practitioner. Already simple therapy approaches can lead to a considerable clinical improvement of male urinary incontinence. If the initial therapy fails or pathological results (i. e. microhaematuria, recurrent urinary tract infections, raised residual urine and so on) are found, the patient should be referred to a urologist.

[The male genital in legal medicine].

PubMed

Albrecht, K; Schultheiss, D

2006-02-01

Pathomorphological findings for the male genital are an exception among forensic cases. In earlier publications they were usually published as individual cases. A significant percentage are the so-called fertility- and potency medical certificates, which are usually commissioned for doubtful paternity cases. Old forensic writings about genital injuries distinguish--apart from the necessity of a complete dissection--between "deadly as such" and "accidentally deadly" injuries. Another group consists of reports about self-inflicted genital mutilation, e.g. among prison inmates or soldiers of the last world wars to become an invalid. When it was necessary to identify a corpse, e.g. in cases of progressive decomposition, Merkel recommended in 1945 the representation of the so-called "Schnepfenkopf" (snipe head; colliculus seminalis) in the lesser pelvis. In this article a medical and forensic review of forensically relevant findings of the male genital is presented and illustrated with historical cases.

Male homosexuality and spirit possession in Brazil.

PubMed

Fry, P

1985-01-01

This paper examines the relationship between male homosexuality and the Afro-Brazilian possession cults in Belém do Parà. After a discussion of the literature follows a description of the cults' beliefs, rites and social organization. Male sex roles are then discussed and the two categories, bicha and man, analyzed. It is noted that there is no term which is equivalent to the western category of "homosexual" in this taxonomic system. After putting forward folk explanations for the presence of many bichas in the cults, an analysis is put forward of the social rewards available to bichas within these cults, and the structural relationship between homosexuality and these regions in terms of their congruent marginality vis-à-vis "normal society."

Male genital leiomyomas showing androgen receptor expression.

PubMed

Suárez-Peñaranda, José Manuel; Vieites, Begoña; Evgenyeva, Elena; Vázquez-Veiga, Hugo; Forteza, Jeronimo

2007-12-01

Genital leiomyoma in men include those superficial leiomyomas arising in the scrotum and the areola. They are unusual neoplasms: few cases have been reported in the literature and they usually escape clinical diagnosis. Three cases of male genital leiomyomas are reported: two in the scrotum and one in the areola. They were all conservatively excised and the behaviour was completely benign in all cases. Histopathological examination showed the typical findings of superficial leiomyomas, with some minor differences between cases arising in the scrotum and those from the areola. Immunohistochemical findings not only confirmed the smooth muscle nature of all cases but also showed unequivocal immunostaining for androgen receptors in the leiomyomas from the scrotum. Immunostaining for androgen receptors in scrotal leiomyomas is, as far as we are aware, a previously unknown characteristic of male genital leiomyomas. This finding supports the role of steroid hormones in the growth of genital leiomyomas, similar to leiomyomas found in other locations.

Protein requirements in male adolescent soccer players.

PubMed

Boisseau, N; Vermorel, M; Rance, M; Duché, P; Patureau-Mirand, P

2007-05-01

Few investigations have studied protein metabolism in children and adolescent athletes which makes difficult the assessment of daily recommended dietary protein allowances in this population. The problematic in paediatric competitors is the determination of additional protein needs resulting from intensive physical training. The aim of this investigation was to determine protein requirement in 14-year-old male adolescent soccer players. Healthy male adolescent soccer players (N = 11, 13.8 +/- 0.1 year) participated in a short term repeated nitrogen balance study. Diets were designed to provide proteins at three levels: 1.4, 1.2 and 1.0 g protein per kg body weight (BW). Nutrient and energy intakes were assessed from 4 day food records corresponding to 4 day training periods during 3 weeks. Urine was collected during four consecutive days and analysed for nitrogen. The nitrogen balances were calculated from mean daily protein intake, mean urinary nitrogen excretion and estimated faecal and integumental nitrogen losses. Nitrogen balance increased with both protein intake and energy balance. At energy equilibrium, the daily protein intake needed to balance nitrogen losses was 1.04 g kg(-1) day(-1). This corresponds to an estimated average requirement (EAR) for protein of 1.20 g kg(-1) day(-1) and a recommended daily allowance (RDA) of 1.40 g kg(-1) day(-1) assuming a daily nitrogen deposition of 11 mg kg(-1). The results of the present study suggest that the protein requirements of 14-year-old male athletes are above the RDA for non-active male adolescents.

Sexual reflexes in male and female rats.

PubMed

Chung, S K; McVary, K T; McKenna, K E

1988-12-05

A novel preparation for the study of male and female sexual function in anesthetized, acutely spinalized rats is reported. In both sexes, the coitus reflex (the neuromuscular concomitants of sexual climax) could be elicited by mechanical stimulation of the distal urethra. It is concluded that the spinal sexual circuitry is essentially similar in both sexes and that the coitus reflex is generated by a hormone-insensitive spinal pattern generator and is triggered by a simple peripheral stimulus.

Expensive Egos: Narcissistic Males Have Higher Cortisol

PubMed Central

Reinhard, David A.; Konrath, Sara H.; Lopez, William D.; Cameron, Heather G.

2012-01-01

Background Narcissism is characterized by grandiosity, low empathy, and entitlement. There has been limited research regarding the hormonal correlates of narcissism, despite the potential health implications. This study examined the role of participant narcissism and sex on basal cortisol concentrations in an undergraduate population. Methods and Findings Participants were 106 undergraduate students (79 females, 27 males, mean age 20.1 years) from one Midwestern and one Southwestern American university. Narcissism was assessed using the Narcissistic Personality Inventory, and basal cortisol concentrations were collected from saliva samples in a laboratory setting. Regression analyses examined the effect of narcissism and sex on cortisol (log). There were no sex differences in basal cortisol, F(1,97) = .20, p = .65, and narcissism scores, F(1,97) = .00, p = .99. Stepwise linear regression models of sex and narcissism and their interaction predicting cortisol concentrations showed no main effects when including covariates, but a significant interaction, β = .27, p = .04. Narcissism was not related to cortisol in females, but significantly predicted cortisol in males. Examining the effect of unhealthy versus healthy narcissism on cortisol found that unhealthy narcissism was marginally related to cortisol in females, β = .27, p = .06, but significantly predicted higher basal cortisol in males, β = .72, p = .01, even when controlling for potential confounds. No relationship was found between sex, narcissism, or their interaction on self-reported stress. Conclusions Our findings suggest that the HPA axis is chronically activated in males with unhealthy narcissism. This constant activation of the HPA axis may have important health implications. PMID:22292062

Endocrine approaches to male fertility control.

PubMed

Knuth, U A; Nieschlag, E

1987-02-01

As in the female, gametogenesis in the male is under the control of luteinizing hormone (LH) and follicle stimulating hormone (FSH). Their suppression should inhibit spermatogenesis. If a non-androgenic substance is used to suppress gonadotrophins, androgens must be supplemented to maintain virility, potency and metabolic processes. To avoid administration of several substances, testosterone and its esters were used to develop a male antifertility agent. Although azoospermia can be induced in a high proportion of men with administration of testosterone esters alone, this effect is not uniform. Even frequent injections with testosterone enanthate at weekly intervals fail to inhibit spermatogenesis in all participants. Combinations of gestagenic compounds with testosterone esters show a somewhat better effect, but again azoospermia is only achieved in around 50% of participants. LHRH analogues, although considered by many to offer a realistic potential for male fertility regulation, have not been proven to be successful for this purpose so far. Animal studies in monkeys and preliminary clinical trials demonstrate that agonistic analogues of LHRH have to be given continuously by pump or implant to achieve a pronounced effect on spermatogenesis. But even under these provisions, results in clinical trials have been worse than effects achieved with testosterone/gestagen combinations. Whether new antagonistic compounds offer a better potential awaits clinical trials. Studies in non-human primates demonstrate that testosterone by itself can maintain and initiate spermatogenesis. Based on these findings one could postulate an attenuating effect of high serum androgen levels after supplementation with available testosterone esters. Trials of alternative androgenic substances with slow-release characteristics and without high serum levels after single injections, like 19-nortestosterone hexyloxyphenylpropionate (19NT-HPP), tend to support this theory. With slow

[Cutaneous manifestations of male breast cancer].

PubMed

Hali, Fouzia; Khadir, Khadija; Idhammou, Wassima; Bensardi, Fatima-Zahra; Lefriyekh, Mohamed-Rachid; Benider, Abdelatif; Zamiati, Soumia; Benchikhi, Hakima

2011-11-01

The appearance of skin symptoms in male breast is the main reason for consultation in our context. The aim of this study is to describe the various cutaneous manifestations of male breast cancer through a series of cases collected in a dermatology department. A retrospective study was conducted in the dermatology department at the CHU Ibn Rochd January 1988 to December 2009. All cases of male breast cancer initially diagnosed in dermatology were included. The various epidemiological, clinical, histological and therapeutic data were collected from medical records. Twenty cases were collected. The mean age was 61.25 years. Skin invasion by tumor was found in all patients, and it was the reason for consultation. It was a cutaneous involvement at the nipple and areola (17 cases) and at the periareolar skin (three cases). The clinical appearance of skin involvement was vegetative type in 12 cases, infiltrating with nipple retraction in five cases and nodule with skin change in three cases. The average period of consultation was 25 months. The axillary lymph nodes were noted in 11 patients and distant metastases in eight patients. The cutaneous metastases outside breast were noted in six patients. The histological types were: infiltrating ductal carcinoma in 15 cases (75%), papillary carcinoma in two cases (10%) and non-specific carcinoma in three cases (15%). The treatment was surgery in 14 patients and consisted of radical mastectomy with complete axillary nodal dissection according to Patey. Complementary therapies, chemotherapy or radiotherapy, were indicated in 14 patients. Our single-center study with dermatological recruitment illustrates the frequency and variety of skin disease in male breast cancer and demonstrates that they are still the main reason for consultation in our context. Better information for public and practitioners would allow earlier diagnosis and a more favourable prognosis. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Male infertility in a private Kenyan hospital.

PubMed

Muthuuri, J M

2005-07-01

To study the incidence and aetiology of male infertility in Mombasa, Kenya. Retrospective study. The Mombasa Hospital Private Clinics, from January 1996 to 2001. Forty three men, aged between 21 and 55 years, referred to me with the chief complaint of infertility of unknown cause. Patients were managed conservatively and operatively. Histological and laboratory evaluations. Of the 43 patients observed, ten (23%) presented with signs of hypogonadism, fifteen (35%) with signs of acute and sub-acute inflammatory process (pain and swelling), four (9%) and prolactinaemia, two (5%) had signs of gonadotropin insufficiency and another two (5%) patients had varicocoeles. We did not establish the cause in ten (23%) patients. Male infertility in Mombasa appears to be primarily due to hypogonadism (23%), although in an equal proportion the cause is not obvious (idiopathic). A significant number of the infertility cases can be attributed to easily treatable conditions such as infections and infestations (16%). The sample available is however not big enough to warrant any major conclusions as to the overall male infertility status in establishing possible avenues for future research.

Male reproductive strategy and decreased longevity.

PubMed

Vinogradov, A E

1998-06-01

An explanation of the inter-gender difference in longevity consistent with the 'disposable soma' theory of ageing is proposed. It is based on the concept of r-K selection as applied to the inter-gender situation. The concept predicts that the gender with a higher potential reproductive rate (males) should invest relatively less in somatic maintenance, which in its turn should result in a lower longevity according to the 'disposable soma' theory of ageing. In females, which are interpreted as K-selected organisms, the reproductive strategy strongly depends on steady, secure constitution designed for oocyte/embryo bearing and is therefore closely related to somatic maintenance, whereas in (r-selected) males it has a greater behavioural component--risky, variable, with a greater potential productive success at the expense of somatic maintenance. The higher metabolic and growth rates, a higher premature mortality and a longer period of sexual competence of males also find explanation as a complex of r-selected traits.

Male Batterers’ Alcohol Use and Gambling Behavior

PubMed Central

Febres, Jeniimarie; Shorey, Ryan; Strong, David; Ninnemann, Andrew; Elmquist, Joanna; Andersen, Shawna M.; Bucossi, Meggan; Schonbrun, Yael C.; Temple, Jeff R.; Stuart, Gregory L.

2012-01-01

Little work has examined the interrelations among intimate partner violence (IPV), alcohol use, and gambling behavior, and no studies have examined these relationships among males court-ordered to batterer intervention programs (BIPs). The aim of the current investigation was to explore the associations between IPV, alcohol use, and gambling behavior among 341 males court-mandated to attend BIPs utilizing self-report measures. Voluntary, anonymous questionnaires were administered and completed during regularly scheduled BIP sessions. Compared to the general population, a higher percentage of the sample met criteria for pathological gambling (9%), and problem gambling (17%). Further, males exhibiting pathological gambling were more likely to be hazardous drinkers, and hazardous drinkers were more likely to exhibit pathological gambling. Additionally, pathological gamblers were at an increased risk for the perpetration of both physical and sexual aggression. Finally, gambling behavior uniquely predicted the perpetration of sexual aggression above and beyond alcohol use, impulsivity, and relationship satisfaction. The implications of these results for future research and intervention are discussed. PMID:21516369

Male lifespan and the secondary sex ratio.

PubMed

Catalano, Ralph; Bruckner, Tim

2006-01-01

Literature speculating on the fetal origins of later life morbidity often invokes the "damaged cohort" theory, i.e., that maternal responses to exogenous shocks induce "stress reactivity" in fetuses and thereby shorten the lifespan of males in utero during stressful times. A rival, or "culled cohort," theory posits that exogenous shocks to gravid females induce spontaneous abortions of frail male fetuses, leaving relatively hardy survivors who enjoy, on average, lifespans longer than males in less stressed birth cohorts. A recent test based on archival data from Sweden supported the culled cohort theory. Several characteristics of the Swedish data, however, raise questions regarding the external validity of the findings. We repeat the test with data from Denmark, Iceland, and England and Wales. We use time-series methods that control for trends, seasonal cycles, and other forms of autocorrelation that could confound the test. None of the results supports the "damaged cohort" theory. Consistent with the Swedish findings and with evolutionary theory, we find support in Iceland and England and Wales for the "culled cohort" theory. We discuss the implications of our findings for basic research as well as for public health.

Osteoporosis in the aging male: Treatment options

PubMed Central

Tuck, Stephen P; Datta, Harish K

2007-01-01

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

The evolution of humor from male aggression.

PubMed

Shuster, Sam

2012-01-01

The response to seeing a man riding a unicycle was reported to be consistently related to the viewer's sex and stage of physical development. To see if this observation was universal, observations of responses were collected from 23 male and 9 female unicyclists aged 15-69 years, with 2-40 years cycling experience across four continents. With two exceptions among men, the findings were the same as those originally reported: children showed interest and curiosity, young girls showed little interest, while adult women showed a kindly, concerned, praising response. By contrast, boys showed physical aggression, which became more verbal, merging in the later teens to the snide, aggressive, stereotyped humorous response shown by adult males, which became less frequent in elderly men. The universality of the response across different individuals, environments, and dates of observation suggests an endogenous mechanism, and the association with masculine development relates this to androgen. The theoretical consequences are discussed. It is concluded that humor develops from aggression in males and is evolutionarily related to sexual selection.

Participants in urban Mexican male homosexual encounters.

PubMed

Carrier, J M

1971-12-01

Preliminary data are presented on 53 urban Mexican males interviewed during 1970-1971 in a study of homosexual encounters in a large Mexican city. These data are compared with data from recent studies in the United States and England of male homosexual behavior. Although preliminary and limited, the Mexican data indicate that cultural factors are important determinants of life styles and sex practices of homosexual males. Forty-eight of the 53 (90%) preferred and usually practiced anal intercourse, four preferred oral contacts, and one preferred mutual masturbation. Interviewees were also grouped according to major type of sex activity during the first sustained year of homosexual activity after puberty. One intragroup comparison indicates significant differences between anal active and anal passive interviewees. For example, as children anal passive subjects had significantly more homosexual contacts with adults; they also considered themselves more effeminate and as children were more involved with female sex-typed activities. Comparison of data from the English and United States studies with the present data suggests that preference for a particular sexual technique is not as developed in the former two countries; when there is a preference, it is not usually for anal intercourse.

Subtotal obstruction of the male reproductive tract.

PubMed

Dohle, G R; van Roijen, J H; Pierik, F H; Vreeburg, J T M; Weber, R F A

2003-03-01

Bilateral obstruction of the male reproductive tract is suspected in men with azoospermia, normal testicular volume and normal FSH. A testicular biopsy is required to differentiate between an obstruction and a testicular insufficiency. Unilateral or subtotal bilateral obstructions and epididymal dysfunction may cause severe oligozoospermia in men with a normal spermatogenesis. However, information on spermatogenesis in oligozoospermic men is lacking, since testicular biopsy is not routinely performed. Men with a sperm concentration of <1 x 10(6) spermatozoa/ml were investigated for possible partial obstruction by performing a testicular biopsy under local anaesthesia. Spermatogenesis was determined by the Johnsen scoring method. A testicular biopsy was performed in 78 men with severe oligozoospermia. The medical history showed male accessory gland infection in 12.8%, previous hernia repair in 14.1% and a history of cryptorchidism in 12.8%. A normal or slightly disturbed spermatogenesis (Johnsen score >8) was present in 39/78 (50%) of the men. Hernia repair occurred more often in men with normal spermatogenesis. A varicocele was predominantly seen in men with a disturbed spermatogenesis. FSH was significantly lower ( P<0.0001) in men with normal spermatogenesis. Subtotal obstruction of the male reproductive tract is a frequent cause of severe oligozoospermia in men with a normal testicular volume and a normal FSH. In other cases, an epididymal dysfunction might explain the oligozoospermia in men with a normal testicular biopsy score.

Sexual confusion among certain college males.

PubMed

Goff, J L

1990-01-01

In dealing with college age (18-22) males, clinical observations have shown a fairly common inability to successfully form intimate relationships with same-age females. This problem often appears to be due to an inability to bond and trust that is rooted in the formative years in the nuclear home. When this happens, the young male frequently develops a fear of being sexually abnormal, perhaps even homosexual. This manifests itself in shame, anxiety, depression, denial, reaction formation, performance anxiety, concern about being found out, isolation, substance abuse and, occasionally, acting out. Getting such persons to admit these fears is generally extremely difficult, requiring gentle and empathetic, but persistent, probing on the part of the therapist. Therapy consists of understanding and acceptance by the client that these fears are most often reactive, that they are commonly held, and that when they are seen in proper perspective, they often diminish. The present paper reviews some of the literature on sexual developmental issues of the adolescent male as a backdrop for this problem. The specific difficulties related to reactive homophobia are explored, and some therapeutic approaches suggested.

Eppin: a molecular strategy for male contraception.

PubMed

Wang, Zengjun; Widgren, E E; Richardson, R T; Orand, M G

2007-01-01

New male contraceptives, both hormonal and non-hormonal, have many obstacles to overcome before they reach the market as a product. For hormonal contraceptives the long-term efficacy of oligospermia in a large population of unselected men remains to be determined. For nonhormonal contraception target selection remains a primary goal. Immunocontraception, which showed great promise for many years, has recently lost its appeal. Nevertheless, immunocontraception can be utilised as a strategy, particularly in primates, to discern the function of target molecules in the male. As an example, we discuss Eppin, an epididymal protease inhibitor that coats the surface of human spermatozoa. Because Eppin is predicted to be a serine protease inhibitor with chymotrypsin-like specificity and binds semenogelin, the natural substrate of PSA (prostate specific antigen, a serine protease), we investigated whether Eppin would modulate PSA activity and the hydrolysis of semenogelin. Additionally, because antibodies to Eppin provide contraception in male monkeys, we investigated whether antibodies to Eppin would inhibit the PSA hydrolysis of semenogelin. Eppin is a specific inhibitor of PSA activity that requires leucine 87, Eppin's P1 reactive site. Although Eppin modulates the hydrolysis of semenogelin by PSA, antibodies to Eppin do not inhibit PSA activity.

Anthropometric characteristics of elite male junior rowers

PubMed Central

Bourgois, J.; Claessens, A.; Vrijens, J.; Philippaerts, R.; Van Renterghem, B.; Thomis, M.; Janssens, M.; Loos, R.; Lefevre, J.

2000-01-01

During the 1997 Fédération Internationale des Sociétés d'Aviron World Junior Rowing Championships, anthropometric data on 383 male junior rowers were assessed. With 430 participating athletes, the sample represented 89% of the population. In addition to age, 27 dimensions were measured: body mass, six heights or lengths, four breadths, 10 girths, and six skinfolds. The elite male junior rowers were tall (187.4 (5.8) cm; mean (SD)) and heavy (82.2 (7.4) kg), with larger length, breadth, and girth dimensions than a nationally representative sample of Belgian boys of the same chronological age. A rowing specific anthropometric profile chart with norms was constructed. The stature of the junior rowers is similar to that of adult heavyweight elite rowers, except that the junior rowers are lighter. Compared with non-finalists, finalists are heavier (but still lighter than the adult heavyweight elite rower) and taller, with greater length, breadth (except for the bicristal diameter), and girth dimensions. Key Words: anthropometry; body size; males; junior; rowers PMID:10854024

Human male infertility and its genetic causes.

PubMed

Miyamoto, Toshinobu; Minase, Gaku; Shin, Takeshi; Ueda, Hiroto; Okada, Hiroshi; Sengoku, Kazuo

2017-04-01

Infertility affects about 15% of couples who wish to have children and half of these cases are associated with male factors. Genetic causes of azoospermia include chromosomal abnormalities, Y chromosome microdeletions, and specific mutations/deletions of several Y chromosome genes. Many researchers have analyzed genes in the AZF region on the Y chromosome; however, in 2003 the SYCP3 gene on chromosome 12 (12q23) was identified as causing azoospermia by meiotic arrest through a point mutation. We mainly describe the SYCP3 and PLK4 genes that we have studied in our laboratory, and add comments on other genes associated with human male infertility. Up to now, The 17 genes causing male infertility by their mutation have been reported in human. Infertility caused by nonobstructive azoospermia (NOA) is very important in the field of assisted reproductive technology. Even with the aid of chromosomal analysis, ultrasonography of the testis, and detailed endocrinology, only MD-TESE can confirm the presence of immature spermatozoa in the testes. We strongly hope that these studies help clinics avoid ineffective MD-TESE procedures.

Xenoesterogens and male infertility: myth or reality?

PubMed

Rozati, R; Reddy, P P; Reddanna, P; Mujtaba, R

2000-12-01

To evaluate the role of polychlorinated biphenyls (PCBs) as a potential environmental hazard in the deterioration of male fertility. Fifty-three males were studied. After a thorough case history evaluation and relevant clinical and laboratory investigations, PCBs were estimated in the seminal plasma of 21 infertile men with "Unexplained Male Factor" and 32 fertile controls. Peak retention times of the eluants were compared with those of the commercially available standard PCB Mix, and the results confirmed spectrophotometrically. Seminal PCB concentrations were compared between i) fertile and infertile men and ii) men from different areas and diets. The relationship between PCB concentrations and measures of sperm quality such as the total motile sperm count, was assessed. PCBs were detected in seminal plasma of infertile men but absent from controls. Sperm quantity and quality were significantly lower in infertile men compared to controls. The highest average PCB concentrations were found in fish-eating urban dwellers, and followed in succession by fish-eating rural dwellers, non fish-eating urban dwellers and non fish-eating rural dwellers. The total motile sperm counts were inversely proportional to the PCB concentrations and were significantly lower than those of the respective controls. PCBs may be instrumental in the deterioration of sperm quantity and quality, a contaminated fish diet being the main source of exposure.

Game Performance Evaluation in Male Goalball Players

PubMed Central

Molik, Bartosz; Morgulec-Adamowicz, Natalia; Kosmol, Andrzej; Perkowski, Krzysztof; Bednarczuk, Grzegorz; Skowroński, Waldemar; Gomez, Miguel Angel; Koc, Krzysztof; Rutkowska, Izabela; Szyman, Robert J

2015-01-01

Goalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg), body height (cm), the arm span (cm) and length of the body in the defensive position (cm). The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03) and the sum of good defense (p = 0.04). The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04), the sum of penalty defenses (p = 0.01), and fouls (p = 0.01). The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level. PMID:26834872

Conceptual model of male military sexual trauma.

PubMed

Elder, William B; Domino, Jessica L; Rentz, Timothy O; Mata-Galán, Emma L

2017-08-01

Male sexual trauma is understudied, leaving much to be known about the unique mental health needs of male survivors. This study examined veteran men's perceptions of the effects of military sexual trauma. Military sexual trauma was defined as physically forced, verbally coerced, or substance-incapacitated acts experienced during military service. Interviews were conducted with 21 male veterans who reported experiencing military sexual trauma. Data were drawn together using a grounded theory methodology. Three categories emerged from data analysis, including (a) types of military sexual trauma (being touched in a sexual way against their will [N = 18]; sexual remarks directed at them [N = 15]; being physically forced to have sex [N = 13]); (b) negative life effects (difficulty trusting others [N = 18]; fear of abandonment [N = 17]; substance use [N = 13]; fear of interpersonal violence [N = 12]; conduct and vocational problems [N = 11]; irritability/aggression [N = 8]; insecurity about sexual performance [N = 8]; difficulty managing anger [N = 8]); and (c) posttraumatic growth (N = 15). Results from this study suggest sexual trauma in the military context may affect systems of self-organization, specifically problems in affective, self-concept, and relational domains, similar to symptoms of those who have experienced prolonged traumatic stressors. This model can be used by clinicians to select treatments that specifically target these symptoms and promote posttraumatic growth. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

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 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.

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.

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

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.

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

Male partner reproductive coercion among women veterans.

PubMed

Rosenfeld, Elian A; Miller, Elizabeth; Zhao, Xinhua; Sileanu, Florentina E; Mor, Maria K; Borrero, Sonya

2018-02-01

Male partner reproductive coercion is defined as male partners' attempts to promote pregnancy through interference with women's contraceptive behaviors and reproductive decision-making. Male partners may try to promote pregnancy through birth control sabotage such as taking away or destroying their partners' contraceptives, refusing to wear condoms, and/or verbally pressuring their partners to abstain from contraceptive use. Reproductive coercion is associated with an elevated risk for unintended pregnancy. Women who experience intimate partner violence, who are in racial/ethnic minorities, and who are of lower socioeconomic status are more likely to experience reproductive coercion. Women veterans who use Veterans Affairs for health care may be particularly vulnerable to reproductive coercion because they are disproportionally from racial/ethnic minority groups and experience high rates of intimate partner violence. We sought to examine the prevalence, correlates, and impact of reproductive coercion among women veterans who are served by the Veterans Affairs healthcare system. We analyzed data from a national telephone survey of women veterans aged 18-44 years, with no history of sterilization or hysterectomy, who had received care within the Veterans Affairs system in the previous 12 months. Participants who had sex with men in the last year were asked if they experienced male partner reproductive coercion. Adjusted logistic regression was used to examine the relationship between participant characteristics and male partner reproductive coercion and the relationship between reproductive coercion and the outcomes of contraceptive method used at last sex and pregnancy and unintended pregnancy in the last year. Among the 1241 women veterans in our study cohort, 11% reported experiencing male partner reproductive coercion in the past year. Black women, younger women, and single women were more likely to report reproductive coercion than their white, older, and

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.

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.

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.

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

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.

Hypopituitarism patterns among adult males with prolactinomas.

PubMed

Peng, Junxiang; Qiu, Mingxing; Qi, Songtao; Li, Danling; Peng, Yuping

2016-05-01

The objective of this study was to characterize hypopituitarism in adult males with prolactinomas. We retrospectively analyzed the records of 102 consecutive patients, classified under three categories based on adenoma size at diagnosis: 1.0-2.0cm (group A), 2.1-4.0cm (group B), and >4.0cm (group C). Further, 76 patients had successful outcomes at follow-up. We compared different forms of pituitary hormone dysfunction (growth hormone deficiency, hypogonadism, hypothyroidism, and hypocortisolism) based on the maximal adenoma diameter. Serum prolactin levels were significantly correlated with the maximal adenoma diameter (r=0.867; P=0.000). Of the patients, 89.2% presented with pituitary failure, which included 74.5% with growth hormone deficiency, 71.6% with hypogonadism, 28.4% with hypothyroidism, and 12.7% with hypocortisolism. The three groups did not differ significantly (P>0.05) in the incidence of hypopituitarism, including the extent of pituitary axis deficiency, at presentation and following treatment. However, there was a statistically significant difference in the degree of hypogonadism in cases of acquired pituitary insufficiency at diagnosis (P=0.000). In adult males with prolactin-secreting adenomas, the most common form of pituitary hormone dysfunction was growth hormone deficiency and hypogonadism, whereas hypocortisolism was less common. The maximal adenoma diameter and prolactin secretion did not determine hormone insufficiency in adult males with prolactinomas, but these factors did affect the degree of both hypogonadism and hypothyroidism. Smaller tumors were found to recur more frequently than large tumors, and recovery was more common in cases of growth hormone deficiency and hypogonadism. Copyright © 2016 Elsevier B.V. All rights reserved.

Addison's disease presenting as male infertility.

PubMed

Kowal, Brian F; Turco, John; Nangia, Ajay K

2006-04-01

To present a case of primary male infertility with severe oligospermia and hyperpigmented skin as the main presenting clinical signs. Case report. University-affiliated teaching hospital. A 32-year-old male with severe oligospermia and his 31-year-old female partner with normal cycles. Hydrocortisone, fludrocortisone, methimazole, and eventual IVF. Improved semen analysis, correction of Addison's disease, correction of hyperthyroidism, and ART pregnancy. Severe oligospermia of 5 million per milliliter with 15% motility and ACTH level of 2,800 pg/mL on presentation. Endocrinology evaluation revealed cortisol of <0.1 microg/dL, and Cortrosyn test showed no response (Addison's disease). The patient was incidentally found to have a thyroid stimulating hormone level of <0.1 microIU/mL, T4 of 9.5 microg/dL, Free T4 Index calculation of 11.6 microg/dL, and quantitative triiodothyronine of 273 ng/dL on presentation. His Addison's disease was managed with hydrocortisone and fludrocortisone, and his hyperthyroidism, with methimazole. Semen parameters increased to 34 million per milliliter with 45% motility and 5% Kruger morphology 1 year after initial presentation. Hormone parameters normalized. Rather than allowing for more time for natural conception or IUI, the couple decided to proceed with IVF because of insurance coverage before semen parameters normalized. This is the first reported case of Addison's disease presenting as male infertility with hyperpigmentation of the skin being the only other presenting sign. The underlying etiology of the Addison's in this case remains uncertain, but it is presumed because of autoimmunity. Addison's disease may be associated with hyperthyroidism, and hyperthyroidism may have contributed to the oligospermia. This case highlights why men with abnormal semen parameters should be thoroughly evaluated before proceeding with assisted reproduction.

The control of male sexual responses.

PubMed

Courtois, Frédérique; Carrier, Serge; Charvier, Kathleen; Guertin, Pierre A; Journel, Nicolas Morel

2013-01-01

Male sexual responses are reflexes mediated by the spinal cord and modulated by neural circuitries involving both the peripheral and central nervous system. While the brain interact with the reflexes to allow perception of sexual sensations and to exert excitatory or inhibitory influences, penile reflexes can occur despite complete transections of the spinal cord, as demonstrated by the reviewed animal studies on spinalization and human studies on spinal cord injury. Neurophysiological and neuropharmacological substrates of the male sexual responses will be discussed in this review, starting with the spinal mediation of erection and its underlying mechanism with nitric oxide (NO), followed by the description of the ejaculation process, its neural mediation and its coordination by the spinal generator of ejaculation (SGE), followed by the occurrence of climax as a multisegmental sympathetic reflex discharge. Brain modulation of these reflexes will be discussed through neurophysiological evidence involving structures such as the medial preoptic area of hypothalamus (MPOA), the paraventricular nucleus (PVN), the periaqueductal gray (PAG), and the nucleus para-gigantocellularis (nPGI), and through neuropharmacological evidence involving neurotransmitters such as serotonin (5-HT), dopamine and oxytocin. The pharmacological developments based on these mechanisms to treat male sexual dysfunctions will complete this review, including phosphodiesterase (PDE-5) inhibitors and intracavernous injections (ICI) for the treatment of erectile dysfunctions (ED), selective serotonin reuptake inhibitor (SSRI) for the treatment of premature ejaculation, and cholinesterase inhibitors as well as alpha adrenergic drugs for the treatment of anejaculation and retrograde ejaculation. Evidence from spinal cord injured studies will be highlighted upon each step.

Delivery of Confidential Care to Adolescent Males

PubMed Central

Rubin, Susan E.; McKee, M. Diane; Campos, Giselle; O’Sullivan, Lucia F.

2014-01-01

Purpose Primary care providers’ (PCPs’) provision of time alone with an adolescent without the parents present (henceforth referred to as “confidential care”) has a significant impact on adolescents’ disclosure of risk behavior. To inform the development of interventions to improve PCPs’ delivery of confidential care, we obtained the perspectives of adolescent males and their mothers about the health care concerns of adolescent males and the provision of confidential care. Methods This focus-group study (5 groups: 2 with adolescent males and 2 with mothers) used standard qualitative methods for analysis. We recruited mother/son dyads who had been seen at urban primary care practices. Results Adolescents’ health concerns focused on pregnancy and sexually transmitted infections; mothers took a broader view. Many adolescents felt that PCPs often delivered safe sex counseling in a superficial, impersonal manner that did not add much value to what they already knew, and that their PCP’s principal role was limited to performing sexually transmitted infection testing. Though adolescents cited a number of advantages of confidential care and disclosure, they expressed some general mistrust in PCPs and concerns about limits of confidentiality. Rapport and relationship building with their PCP are key elements to adolescents’ comfort and increased disclosure. Overall, mothers viewed confidential care positively, especially in the context of continuity of care, but many felt excluded. Conclusions To increase adolescents’ perception of the relevance of primary care and to foster disclosure during health encounters, our participants described the critical nature of a strong doctor–patient relationship and positive physician demeanor and personalized messages, especially in the context of a continuity relationship. Regular, routine inclusion of confidential care time starting early in adolescence, as well as discussion of the purpose and limitations of

Erectile Dysfunction in the Older Adult Male.

PubMed

Mola, Joanna R

2015-01-01

Erectile dysfunction (ED) in the older adult male is a significant problem affecting more than 75% of men over 70 years of age in the United States. Older men have an increased likelihood of developing ED due to chronic disease, comorbid conditions, and age-related changes. Research has demonstrated that while the prevalence and severity of ED increases with age, sexual desire often remains unchanged. This article discusses the clinical picture of ED, including relevant pathophysiology, clinical presentation, and evaluation and treatment options.

Male contraception: what is on the horizon?

PubMed

Blithe, Diana

2008-10-01

Male contraception remains an important area of research. Methods can inhibit sperm production or can be targeted to inhibit sperm functions such as motility, orientation or interaction with the egg. Hormonal methods appear to be safe and effective in proof of concept studies but efforts are underway to improve delivery options or lead time until full efficacy is achieved. Nonhormonal methods are based on numerous targets that impact sperm production or function. Several agents that inhibit the sperm-specific or testis-specific targets have been identified and studies in animals have shown promising results.

Retirement and primary cardiac arrest in males.

PubMed Central

Siscovick, D S; Strogatz, D S; Weiss, N S; Rennert, G

1990-01-01

We investigated the association between retirement and primary cardiac arrest (PCA) in 126 male cases and controls, 25-75 years of age, without prior heart disease or comorbidity. After adjustment for age alone, retirement was not associated with an increased risk of PCA, (OR = 1.1; 95% confidence intervals = 0.5, 2.4). This lack of association was not uniform across age strata, however. In 10 of 19 discordant pairs 60 or more years of age, the control subject had been retired; in all seven discordant pairs under 60, the case had been retired (lower 95% CI of the relative risk = 1.9). PMID:2297069

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.

[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.

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.

Effects of psychological stress on male fertility.

PubMed

Nargund, Vinod H

2015-07-01

Psychological stress can be defined as any uncomfortable 'emotional experience' accompanied by predictable biochemical, physiological and behavioural changes or responses. Many clinical studies looking at the effects of psychological stress on male fertility have shown that stress is associated with reduced paternity and abnormal semen parameters. Enough scientific evidence exists to suggest that psychological stress could severely affect spermatogenesis, mainly as a result of varying testosterone secretion. The hypothalamic-pituitary-adrenal axis has a direct inhibitory action on the hypothalamic-pituitary-gonadal (HPG) axis and Leydig cells in the testes. The newly discovered hormone, gonadotropin-inhibitory hormone (GnIH), also has an inhibitory effect on the HPG axis. Inhibition of the HPG axis results in a fall in testosterone levels, which causes changes in Sertoli cells and the blood-testis barrier, leading to the arrest of spermatogenesis. Germ cells also become vulnerable to gonadotoxins and oxidation. However, the extent and severity of the effects of psychological stress on human testes is difficult to study and data mostly come from animal models. Despite this limitation, stress as a causative factor in male infertility cannot be ignored and patients should be made aware of its effects on testicular function and fertility and helped to manage them.

Recent methodological advances in male hormonal contraception

PubMed Central

Liu, Peter Y.; Swerdloff, Ronald S.; Wang, Christina

2010-01-01

Landmark WHO-sponsored trials showed decades ago that male hormonal contraception (MHC) is an effective male-directed contraceptive approach. Considerable progress has been made particularly in the last 5 years, establishing for the first time the reversibility of MHC and its short-term safety. Methodological advances in recent years include: the pooling of information and individual-level integrated analysis; the first-time use of centralized semen analysis and fluorescence to detect low sperm concentrations; the establishment of sperm quality reference ranges in fertile men; the measurement of blood steroid concentrations by gas or chromatography/mass spectrometry; and the inclusion of placebo groups to delineate clearly possible adverse effects of androgens and progestins in men. We report integrated analyses of factors that are important in predicting suppression and recovery of spermatogenesis after MHC clinical trials for the past 15 years. These are the best data available and will provide guidance and reassurance for the larger scale Phase III specific regimen efficacy studies that will be required to bring MHC to the population (market). PMID:20933121

Progress and prospects in male hormonal contraception

PubMed Central

Amory, John K.

2009-01-01

Purpose of review Testosterone functions as a contraceptive by suppressing the secretion of luteinizing hormone and follicle-stimulating hormone from the pituitary. Low concentrations of these hormones deprive the testes of the signals required for spermatogenesis and results in markedly decreased sperm concentrations and effective contraception in a majority of men. Male hormonal contraception is well tolerated and acceptable to most men. Unfortunately, testosterone-alone regimens fail to completely suppress spermatogenesis in all men, meaning that in some the potential for fertility remains. Recent findings Because of this, novel combinations of testosterone and progestins, which synergistically suppress gonadotropins, have been studied. Two recently published testosterone/progestin trials are particularly noteworthy. In the first, a long-acting injectable testosterone ester, testosterone decanoate, was combined with etonogestrel implants and resulted in 80–90% of subjects achieving a fewer than 1 million sperm per milliliter. In the second, a daily testosterone gel was combined with 3-monthly injections of depot medroxyprogesterone acetate producing similar results. Summary Testosterone-based hormone combinations are able to reversibly suppress human spermatogenesis; however, a uniformly effective regimen has remained elusive. Nevertheless, improvements, such as the use of injectable testosterone undecanoate, may lead to a safe, reversible and effective male contraceptive. PMID:18438174

[Male hormonal contraception: past, present, future].

PubMed

Pásztor, Norbert; Hegyi, Borbála Eszter; Badó, Attila; Németh, Gábor

2017-11-01

In certain regions of the world the enormous rate of population growth raises economic and public health concerns and widely accessible contraceptive methods would be desired. In contrast, in other countries the use of effective contraception is a question of individual preferences. Today, most of the reliable contraceptive methods are applied by women, while the options for male methods are quite limited. It is well known that significant portion of pregnancies are still unplanned and several data revealed men's willingness to take part in family planning. Based on these needs, remarkable efforts have been made to develop a suitable hormonal contraceptive agent for men. With the exogenous suppression of follicle stimulating hormone and luteinizing hormone secretion, the inhibition of the testicular testosterone production and the spermatogenesis can be achieved. In the beginning, testosterone-derivatives, or testosterone-progestin combinations were administered, later synthetic androgen agents were developed. Despite of these efforts, unfortunately, there is no safe, widely feasible male hormonal contraception to date, but in the future this goal can be achieved by solving the key hurdles. Orv Hetil. 2017; 158(46): 1819-1830.

[Male contraception - the current state of knowledge].

PubMed

Zdrojewicz, Zygmynt; Kasperska, Karolina; Lewandowska, Marta

2016-08-01

Contraception is important from a health, psychological and socioeconomic point of view. Due to the fact that male-based contraceptive methods are mostly represented by condoms and vasectomy, researchers are working on the new solutions, which could let the men be more involved in a conscious family planning. In this review we will present the current state of knowledge on this subject. There is a lot going on in the field of hormonal contraception. Studies including testosterone, progestins, synthetic androgens and other derivatives are on a different stages of clinical trials and mostly demonstrate high efficacy rates. Recent discovers of Izumo and Juno proteins, essential for the fertilization process, give hope for an easily reversible, non-hormonal method. Researchers are also trying to interfere with the process of spermatogenesis using BRDT inhibitor - JQ1, or neutralize the sperm by injecting styrene maleic anhydride (SMA) into the lumen of the vas deferens. The other studies explore processes involved in proper sperm motility. A vaccine which induces an immune response to the reproductive system is also an interesting method. The latest research use ultrasound waves and mechanical device which blocks the patency of vas deferens. The aim of the study current state of knowledge male contraception. © 2016 MEDPRESS.

Recent methodological advances in male hormonal contraception.

PubMed

Liu, Peter Y; Swerdloff, Ronald S; Wang, Christina

2010-11-01

Landmark WHO-sponsored trials showed decades ago that male hormonal contraception (MHC) is an effective male-directed contraceptive approach. Considerable progress has been made particularly in the last 5 years, establishing for the first time the reversibility of MHC and its short-term safety. Methodological advances in recent years include the pooling of information and individual-level integrated analysis; the first-time use of centralized semen analysis and fluorescence to detect low sperm concentrations; the establishment of sperm quality reference ranges in fertile men; the measurement of blood steroid concentrations by gas chromatography/mass spectrometry; and the inclusion of placebo groups to delineate clearly possible adverse effects of androgens and progestins in men. We report integrated analyses of factors that are important in predicting suppression and recovery of spermatogenesis after MHC clinical trials for the past 15 years. These are the best data available and will provide guidance and reassurance for the larger-scale Phase III specific regimen efficacy studies that will be required to bring MHC to the population (market). Copyright © 2010 Elsevier Inc. All rights reserved.

Traditional plant aphrodisiacs and male sexual dysfunction.

PubMed

Bella, Anthony J; Shamloul, Rany

2014-06-01

There has been a long history of man’s fascination with better and stronger sex drive and performance across different cultures. Several literature texts from the Hindu, Egyptian, Chinese and Roman civilizations document the human endless search for substances that can enhance sexual experiences and/or treat erectile dysfunction. This review will discuss the current research done on the most popular plant aphrodisiacs and provide evidence to support or discourage the use of any of them to enhance sexual desire and/or function in men. We review the current evidence on the use of natural substances as aphrodisiacs. We found very little evidence to support the use of plant aphrodisiacs in the treatment of male sexual dysfunction. The vast majority of studies were conducted on animals with very few clinical studies. Available data suggest a beneficial effect of ginseng as a pro-sexual supplement and not an independent treatment for male sexual dysfunction. Trans-culturally, many herbal therapies show some potential benefits in improving men’s sexual function; however, adequate studies on the specific benefits and health risks associated with their use are needed. We strongly recommend the design and execution of well-controlled clinical studies to determine the efficacy and safety of plant aphrodisiacs. Copyright © 2013 John Wiley & Sons, Ltd.

Mammary fibroadenomatous hyperplasia in a male cat

PubMed Central

Mayayo, Saray Lorna; Bo, Stefano; Pisu, Maria Carmela

2018-01-01

Case summary Mammary fibroadenomatous hyperplasia (MFH) is a benign pathology characterised by extensive proliferation of the ductal epithelium and mammary stroma. It typically occurs in young female cats, and seems to result from hypersensitivity to progesterone. A 2-year-old entire male European Shorthair cat presented to the veterinary clinic with enlargement of several mammary glands, which had developed within the previous 10 days. There was no prior administration of progestin in the cat’s medical history. Diagnostic tests were performed to assess the basal progesterone concentration and the concentration after stimulation with gonadotropin-releasing hormone, which ruled out the presence of functional ovarian tissue. Histological examination of the testes excluded hormone-secreting testicular tumours. Histological examination of the mammary gland confirmed the diagnosis of MFH. Treatment was started with aglepristone, a selective competitor for progesterone receptors, administered subcutaneously at 15 mg/kg at days 1, 2, 8 and 15. A reduction in the size of the mammary glands was evident 6 days after the first administration, with complete remission observed after 4 weeks. Relevance and novel information To the best of our knowledge, this is the first full report of MFH in a male cat. Although the origin of the progestins responsible for MFH in this case could not be confirmed, in the light of the diagnostic tests performed and the results obtained, accidental contact with hormone-like substances seems to be the only plausible explanation for the cat’s clinical signs. Inhibitor therapy was successful. PMID:29568542

Mammary fibroadenomatous hyperplasia in a male cat.

PubMed

Mayayo, Saray Lorna; Bo, Stefano; Pisu, Maria Carmela

2018-01-01

Mammary fibroadenomatous hyperplasia (MFH) is a benign pathology characterised by extensive proliferation of the ductal epithelium and mammary stroma. It typically occurs in young female cats, and seems to result from hypersensitivity to progesterone. A 2-year-old entire male European Shorthair cat presented to the veterinary clinic with enlargement of several mammary glands, which had developed within the previous 10 days. There was no prior administration of progestin in the cat's medical history. Diagnostic tests were performed to assess the basal progesterone concentration and the concentration after stimulation with gonadotropin-releasing hormone, which ruled out the presence of functional ovarian tissue. Histological examination of the testes excluded hormone-secreting testicular tumours. Histological examination of the mammary gland confirmed the diagnosis of MFH. Treatment was started with aglepristone, a selective competitor for progesterone receptors, administered subcutaneously at 15 mg/kg at days 1, 2, 8 and 15. A reduction in the size of the mammary glands was evident 6 days after the first administration, with complete remission observed after 4 weeks. To the best of our knowledge, this is the first full report of MFH in a male cat. Although the origin of the progestins responsible for MFH in this case could not be confirmed, in the light of the diagnostic tests performed and the results obtained, accidental contact with hormone-like substances seems to be the only plausible explanation for the cat's clinical signs. Inhibitor therapy was successful.

Mental Rotation Performance in Male Soccer Players

PubMed Central

Jansen, Petra; Lehmann, Jennifer; Van Doren, Jessica

2012-01-01

It is the main goal of this study to investigate the visual-spatial cognition in male soccer players. Forty males (20 soccer players and 20 non-athletes) solved a chronometric mental rotation task with both cubed and embodied figures (human figures, body postures). The results confirm previous results that all participants had a lower mental rotation speed for cube figures compared to embodied figures and a higher error rate for cube figures, but only at angular disparities greater than 90°. It is a new finding that soccer–players showed a faster reaction time for embodied stimuli. Because rotation speed did not differ between soccer-players and non-athletes this finding cannot be attributed to the mental rotation process itself but instead to differences in one of the following processes which are involved in a mental rotation task: the encoding process, the maintanence of readiness, or the motor process. The results are discussed against the background of the influence on longterm physical activity on mental rotation and the context of embodied cognition. PMID:23119073

Alternative delivery of male accessory gland products

PubMed Central

2014-01-01

To increase fertilization success, males transfer accessory gland products (Acps). Several species have evolved unconventional Acps transfer modes, meaning that Acps are transferred separately from the sperm. By surveying the sperm-free Acps transfer cases, we show that these animals have evolved a common strategy to deliver Acps: they all inject Acps directly through the partner’s body wall into the hemolymph. Our review of this mode of Acps transfer reveals another striking similarity: they all transfer sperm in packages or via the skin, which may leave little room for Acps transfer via the conventional route in seminal fluid. We synthesise the knowledge about the function, and the effects in the recipients, of the Acps found in the widely diverse taxa (including earthworms, sea slugs, terrestrial snails, scorpions and salamanders) that inject these substances. Despite the clearly independent evolution of the injection devices, these animals have evolved a common alternative strategy to get their partners to accept and/or use their sperm. Most importantly, the evolution of the injection devices for the delivery of Acps highlights how the latter are pivotal for male reproductive success and, hence, strongly influence sexual selection. PMID:24708537

True polyploid meiosis in the human male.

PubMed

Pearson, Peter L; Madan, Kamlesh

2018-05-21

Polyploidy does not usually occur in germinal cells of mammals and other higher vertebrates. We describe a unique example of mosaic autotetraploidy in the meiosis of a human male. Although the original observations were made in the late 1960s, we did not publish them at that time, because we expected to detect further examples that could be described together. However, this did not occur and we have now decided to make the observations available to demonstrate that polyploidy in mammalian male meiosis can arise at a higher frequency than expected by random polyploidization of individual meiotic cells, by either DNA duplication or cell fusion prior to synapsis. This is the first description of a population of primary spermatocytes exhibiting multivalent formation at leptotene /diakinesis in human spermatogenesis, with ring, chain, frying pan and other types of quadrivalents, typical of autotetraploidy. As many of the polyploid configurations showed apoptotic breakdown, it is likely that diploid and/or aneuploid spermatozoa would have rarely or never resulted from this mosaic autotetraploid meiosis.

Vitamin D and male reproductive system.

PubMed

Costanzo, Pablo R; Knoblovits, Pablo

2016-12-01

Vitamin D deficiency is a highly prevalent worldwide condition and affects people of all ages. The most important role of vitamin D is the regulation of intestinal calcium absorption and metabolism of calcium and phosphorus to maintain muscle and bone homeostasis. Furthermore, in recent years it has been discovered that the vitamin D receptor (VDR) is widely distributed in many organs and tissues where vitamin D can perform other actions that include the modulation of the immune response, insulin secretion, anti-proliferative effect on cells of vascular smooth muscle, modulation of the renin-angiotensin-aldosterone system and regulates cell growth in several organs. The VDR is widely distributed in the male reproductive system. Vitamin D induces changes in the spermatozoa's calcium and cholesterol content and in protein phosphorylation to tyrosine/threonine residues. These changes could be involved in sperm capacitation. Vitamin D seems to regulate aromatase expression in different tissues. Studies analyzing seasonal variations of sex steroids in male populations yield conflicting results. This is probably due to the wide heterogeneity of the populations included according to age, systemic diseases and obesity.

Impulsivity and eating behavior in males

PubMed

Jáuregui-Lobera, Ignacio; Santiago, María José

2017-02-01

Introduction: Impulsivity is a personality trait related with the control of behaviour and emotions and it is found in different psychopathological alterations, including those referred to eating behaviour. Objective: The aim of this study was to analyse the relationship among the infl uence of the aesthetic body shape model, eating behaviour (and risk for specific disorders), body mass index and impulsivity. Method: A total of 178 males were included in the study, with a mean age of 20.18 ± 2.48. Height and weight were assessed in order to obtain the body mass index. All participants fulfilled the following questionnaires: Barratt Impulsivity Scale (BIS-11), Questionnaire of Infl uences on the Body Shape Model for males (CIMEC-V) and the Eating Attitudes Test (EAT-40). Results: With respect to possible cases of eating disorders, 5.06% were found. Scores of some items of BIS-11 correlated significantly with the EAT-40 and CIMEC-V scores. Overweight participants (39.89%) showed higher level of impulsivity as well as those with EAT-40 scores above the cut-off point for that test. Conclusions: The assessment of impulsivity from a psychological point of view might be a preventive tool with regards to disordered eating behaviours. Respecting the patients with eating disorders/overweight/obesity, that assessment might be a relevant aspect in order to improve the therapeutical approach.

Predictive Toxicology and Computer Simulation of Male ...

EPA Pesticide Factsheets

The reproductive tract is a complex, integrated organ system with diverse embryology and unique sensitivity to prenatal environmental exposures that disrupt morphoregulatory processes and endocrine signaling. U.S. EPA’s in vitro high-throughput screening (HTS) database (ToxCastDB) was used to profile the bioactivity of 54 chemicals with male developmental consequences across ~800 molecular and cellular features. The in vitro bioactivity on molecular targets could be condensed into 156 gene annotations in a bipartite network. These results highlighted the role of estrogen and androgen signaling pathways in male reproductive tract development, and importantly, broadened the list of molecular targets to include GPCRs, cytochrome-P450s, vascular remodeling proteins, and retinoic acid signaling. A multicellular agent-based model was used to simulate the complex interactions between morphoregulatory, endocrine, and environmental influences during genital tubercle (GT) development. Spatially dynamic signals (e.g., SHH, FGF10, and androgen) were implemented in the model to address differential adhesion, cell motility, proliferation, and apoptosis. Under control of androgen signaling, urethral tube closure was an emergent feature of the model that was linked to gender-specific rates of ventral mesenchymal proliferation and urethral plate endodermal apoptosis. A systemic parameter sweep was used to examine the sensitivity of crosstalk between genetic deficiency and envi

Multiscale Systems Modeling of Male Reproductive Tract ...

EPA Pesticide Factsheets

The reproductive tract is a complex, integrated organ system with diverse embryology and unique sensitivity to prenatal environmental exposures that disrupt morphoregulatory processes and endocrine signaling. U.S. EPA’s in vitro high-throughput screening (HTS) database (ToxCastDB) was used to profile the bioactivity of 54 chemicals with male developmental consequences across ~800 molecular and cellular features [Leung et al., accepted manuscript]. The in vitro bioactivity on molecular targets could be condensed into 156 gene annotations in a bipartite network. These results highlighted the role of estrogen and androgen signaling pathways in male reproductive tract development, and importantly, broadened the list of molecular targets to include GPCRs, cytochrome-P450s, vascular remodeling proteins, and retinoic acid signaling. A multicellular agent-based model was used to simulate the complex interactions between morphoregulatory, endocrine, and environmental influences during genital tubercle (GT) development. Spatially dynamic signals (e.g., SHH, FGF10, and androgen) were implemented in the model to address differential adhesion, cell motility, proliferation, and apoptosis. Urethral tube closure was an emergent feature of the model that was linked to gender-specific rates of ventral mesenchymal proliferation and urethral plate endodermal apoptosis, both under control of androgen signaling [Leung et al., manuscript in preparation]. A systemic parameter sweep w

The epididymis, cytoplasmic droplets and male fertility.

PubMed

Cooper, Trevor G

2011-01-01

The potential of spermatozoa to become motile during post-testicular maturation, and the relationship between the cytoplasmic droplet and fertilizing capacity are reviewed. Post-testicular maturation of spermatozoa involves the autonomous induction of motility, which can occur in vivo in testes with occluded excurrent ducts and in vitro in testicular explants, and artefactual changes in morphology that appear to occur in the testis in vitro. Both modifications may reflect time-dependent oxidation of disulphide bonds of head and tail proteins. Regulatory volume decrease (RVD), which counters sperm swelling at ejaculation, is discussed in relation to loss of cytoplasmic droplets and consequences for fertility. It is postulated that: (i) fertile males possess spermatozoa with sufficient osmolytes to drive RVD at ejaculation, permitting the droplet to round up and pinch off without membrane rupture; and (ii) infertile males possess spermatozoa with insufficient osmolytes so that RVD is inadequate, the droplet swells and the resulting flagellar angulation prevents droplet loss. Droplet retention at ejaculation is a harbinger of infertility caused by failure of the spermatozoon to negotiate the uterotubal junction or mucous and reach the egg. In this hypothesis, the epididymis regulates fertility indirectly by the extent of osmolyte provision to spermatozoa, which influences RVD and therefore droplet loss. Man is an exception, because ejaculated human spermatozoa retain their droplets. This may reflect their short midpiece, approximating head length, permitting a swollen droplet to extend along the entire midpiece; this not only obviates droplet migration and flagellar angulation but also hampers droplet loss.

New male contraceptive entering clinical trials worldwide.

PubMed

1989-10-01

250 men are participating in a clinical trial of a reversible male testosterone contraceptive at the University of Washington in Seattle and at 9 other centers in Europe, Asia, and Australia. Clinicians inject the WHO-developed testosterone enanthate (200 mg) into these men once a week. The testosterone contraceptive instructs the pituitary gland to deactivate 2 hormones which normally maintain the testes' function resulting in a temporary stop of spermatogenesis just like the female oral contraceptive instructs the pituitary gland to suppress ovulation. Tests of 5 ejaculates in preliminary trials have indicated that 50-60% of the men experience azoospermia. Investigators are concerned with the possibility that ejaculates during normal intercourse may contain enough sperm to impregnate the partner. An investigator at the University of Washington believes this clinical trial of 250 men will determine whether this is indeed the case. The concern about contraceptive failure is the main problem with contraceptive testosterone. The minor side effects include weight gain which may be due to increased muscle mass and some sodium retention, acne, and possible reduction of libido but that has not yet occurred in the 250 men in the clinical trial. This contraceptive testosterone does not remain active for long periods of time if administered orally. Researchers are now developing a newer form of the contraceptive which will increase the intervals between administrations from 1 week to 3 months. An investigator from Seattle guesses that this male contraceptive will not be available for marketing in the US until at least 1994.

The pharmacotherapy of male hypogonadism besides androgens.

PubMed

Corona, Giovanni; Rastrelli, Giulia; Ratrelli, Giulia; Maggi, Mario

2015-02-01

Adulthood male hypogonadism (HG) is the most common form of HG. Although testosterone (T) replacement therapy (TRT) is the most common way of treating HG, other options are available depending on patient's needs and expectations. We analyze alternative options to TRT as a medical intervention in treating HG. Gonadotropin (Gn) therapy is the treatment of choice in men with secondary HG (sHG), who require fertility. Gonadotropin-releasing hormone therapy represents an alternative to Gn for inducing spermatogenesis in patients with sHG, however, its use is limited by the poor patient compliance and high cost. In obese HG men, lifestyle modifications and, in particular, weight loss should be the first step. Recent data suggest that antiestrogens represent a successful treatment for sHG. Other potential therapeutic options include the stimulation of hypothalamic activity (i.e., kisspeptin and neurokinin-B agonists). Conversely, the possibility of increasing Leydig cell steroid production, independently from Gn stimulation, seems unreliable. Understanding the nature of male HG and patient's needs are mandatory before choosing among treatment options. For primary HG only TRT is advisable, whereas for the secondary form several alternative possibilities can be offered.

An update on male hypogonadism therapy

PubMed Central

Surampudi, Prasanth; Swerdloff, Ronald S; Wang, Christina

2014-01-01

Introduction Men who have symptoms associated with persistently low serum total testosterone level should be assessed for testosterone replacement therapy. Areas covered Acute and chronic illnesses are associated with low serum testosterone and these should be recognized and treated. Once the diagnosis of male hypogonadism is made, the benefits of testosterone treatment usually outweigh the risks. Without contraindications, the patient should be offered testosterone replacement therapy. The options of testosterone delivery systems (injections, transdermal patches/gels, buccal tablets, capsules and implants) have increased in the last decade. Testosterone improves symptoms and signs of hypogonadism such as sexual function and energy, increases bone density and lean mass and decreases visceral adiposity. In men who desire fertility and who have secondary hypogonadism, testosterone can be withdrawn and the patients can be placed on gonadotropins. New modified designer androgens and selective androgen receptor modulators have been in preclinical and clinical trials for some time. None of these have been assessed for the treatment of male hypogonadism. Expert opinion Despite the lack of prospective long-term data from randomized, controlled clinical trials of testosterone treatment on prostate health and cardiovascular disease risk, the available evidence suggests that testosterone therapy should be offered to symptomatic hypogonadal men. PMID:24758365

An update on male hypogonadism therapy.

PubMed

Surampudi, Prasanth; Swerdloff, Ronald S; Wang, Christina

2014-06-01

Men who have symptoms associated with persistently low serum total testosterone level should be assessed for testosterone replacement therapy. Acute and chronic illnesses are associated with low serum testosterone and these should be recognized and treated. Once the diagnosis of male hypogonadism is made, the benefits of testosterone treatment usually outweigh the risks. Without contraindications, the patient should be offered testosterone replacement therapy. The options of testosterone delivery systems (injections, transdermal patches/gels, buccal tablets, capsules and implants) have increased in the last decade. Testosterone improves symptoms and signs of hypogonadism such as sexual function and energy, increases bone density and lean mass and decreases visceral adiposity. In men who desire fertility and who have secondary hypogonadism, testosterone can be withdrawn and the patients can be placed on gonadotropins. New modified designer androgens and selective androgen receptor modulators have been in preclinical and clinical trials for some time. None of these have been assessed for the treatment of male hypogonadism. Despite the lack of prospective long-term data from randomized, controlled clinical trials of testosterone treatment on prostate health and cardiovascular disease risk, the available evidence suggests that testosterone therapy should be offered to symptomatic hypogonadal men.

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.

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.

Male Scientists’ Competing Devotions to Work and Family: Changing Norms in a Male-Dominated Profession

PubMed Central

Damaske, Sarah; Ecklund, Elaine Howard; Lincoln, Anne E.; White, Virginia Johnston

2014-01-01

Using in-depth interviews with 74 men across different ranks in biology and physics at prestigious US universities, we ask to what extent changing norms of fatherhood and a flexible workplace affect men working in a highly male-dominated profession and what variation exists in family forms. We conceptualize four typologies of men: those forgoing children, egalitarian partners, neo-traditional dual-earners, and traditional breadwinners. Findings suggest male scientists hold strong work devotions yet a growing number seek egalitarian relationships, which they frame as reducing their devotion to work. The majority of men find the all-consuming nature of academic science conflicts with changing fatherhood norms. PMID:25419040

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

Comparisons of voice onset time for trained male singers and male nonsingers during speaking and singing.

PubMed

McCrea, Christopher R; Morris, Richard J

2005-09-01

This study was designed to examine the temporal acoustic differences between male trained singers and nonsingers during speaking and singing across voiced and voiceless English stop consonants. Recordings were made of 5 trained singers and 5 nonsingers, and acoustically analyzed for voice onset time (VOT). A mixed analysis of variance showed that the male trained singers had significantly longer mean VOT than did the nonsingers during voiceless stop production. Sung productions of voiceless stops had significantly longer mean VOTs than did the spoken productions. No significant differences were observed for the voiced stops, nor were any interactions observed. These results indicated that vocal training and phonatory task have a significant influence on VOT.

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.

Leading Causes of Death in Males United States, 2010

MedlinePlus

... Submit What’s this? Submit Button Leading Causes of Death in Males and Females, United States Recommend on ... and previous listings for the leading causes of death for males and females in the United States. ...

METHOXYCHLOR METABOLISM AND VITELLOGENINESIS IN MALE RAINBOW TROUT LIVER SLICES

EPA Science Inventory

Induction of vitellogenesis (VTG) in male fish has become an accepted biomarker for xenoestrogenicity. This study utilized the male rainbow trout liver slice model to determine the estrogenicity of parent compound, methoxychlor (MXC) and metabolites, di-hydroxy methoxychlor (HPTE...

Negotiating "Otherness": A Male Early Childhood Educator's Gender Positioning.

ERIC Educational Resources Information Center

Sumsion, Jennifer

2000-01-01

Describes the gender positioning strategies adopted by a male Australian preschool teacher-director as he faces attitudes that early childhood education is "women's work." Discusses implications of a greater male presence in early childhood education. (JPB)

Taste receptor polymorphisms and male infertility.

PubMed

Gentiluomo, M; Crifasi, L; Luddi, A; Locci, D; Barale, R; Piomboni, P; Campa, D

2017-11-01

Are polymorphisms of taste receptor genes associated with male infertility? This study has showed the associations between three single nucleotide polymorphisms (SNPs) in taste receptors genes (TASR) and male infertility. Recent studies showed the expression of taste receptors in the testis and in spermatozoa, suggesting their possible role in infertility. The vast genetic variability in taste genes results in a large degree of diversity in various human phenotypes. In this study, we genotyped 19 SNPs in 12 taste related genes in a total of 494 Caucasian male patients undergoing semen evaluation at the Centre of Couple Sterility of the Siena University Hospital. Consecutive patients were enrolled during infertility investigations from October 2014 to February 2016. Median age of the patients was 36 years (18-58) and 141 were smokers. Genotyping was performed using the allele-specific PCR. The statistical analysis was carried out using generalized linear model (GLM) to explore the association between age, smoking, the genetic polymorphisms and sperm parameters. We observed that the homozygous carriers of the (G) allele of the TAS2R14-rs3741843 polymorphism showed a decreased sperm progressive motility compared to heterozygotes and (A) homozygotes (P = 0.003). Moreover, the homozygous carriers of the (T) allele of the TAS2R3-rs11763979 SNP showed fewer normal acrosome compared with the heterozygous and the homozygous carriers of the (G) allele (P = 0.002). Multiple comparisons correction was applied and the Bonferroni-corrected critical P-value was = 0.003. The analysis is restricted to SNPs within genes and to men of Caucasian ancestry. In silico analyses strongly point towards a functional effect of the two SNPs: TAS2R14-rs3741843 regulates TAS2R43 expression, a gene that is involved in cilia motility and therefore could influences sperm mobility; the (T) allele of TAS2R3-rs11763979 increases the expression of the WEE2 antisense RNA one gene (WEE2-AS1). According

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 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

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

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.

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.

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…

Psychological Characteristics of Adolescent Males Who Have Been Sexually Abused.

ERIC Educational Resources Information Center

Boisso, Cynthia V.; And Others

While female victims of sexual abuse have received increased attention, male victims continue to be overlooked. Recognition of effects of sexual abuse has been an important step in increasing identification of and treatment for victims of abuse. To assess the characteristics of male victims, sexually abused male (N=13) and female (N=16)…

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…

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 ...

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

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...

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.…

Relative Heights of Males and Females in Children's Drawings.

ERIC Educational Resources Information Center

Cox, Maureen V.; Wright, Rebekah

2000-01-01

Examined in two studies the height of male and female figures in 5- and 7-year-olds' drawings. Found that adult figures were drawn taller than child figures. For boys, mean male and female heights were approximately the same. Girls drew females taller than males because more girls used different structures such as incorporating a skirt or trousers…

Minor Delinquency and Immigration: A Longitudinal Study among Male Adolescents

ERIC Educational Resources Information Center

Titzmann, Peter F.; Silbereisen, Rainer K.; Mesch, Gustavo

2014-01-01

On the basis of general theories of delinquency and the specific situation of immigrants, this longitudinal study investigated predictors of initial levels and rates of change in delinquency among 188 male ethnic German Diaspora immigrants from the former Soviet Union (FSU) in Germany, 237 male native German adolescents, and 182 male Jewish…

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,…

Social Responsibility Personality Differences between Male and Female Communicators.

ERIC Educational Resources Information Center

Hantz, Alan M.; Wright, Donald K.

A study was conducted to explore in what ways, if any, male public relations practitioners differ from their female counterparts in their level of social responsibility. Subjects were 105 public relations practitioners (60% female and 40% male) and 215 college students (71% female and 29% male), who completed the Berkowitz-Lutterman SRS Scale. The…

Perceptions of Child Support and Sexual Activity of Adolescent Males

ERIC Educational Resources Information Center

Huang, Chien-Chung; Han, Wen-Jui

2004-01-01

Using the 1995 new cohort of the National Survey of Adolescent Males, this paper examines the association between perceptions of child support and adolescent males' sexual activity. The results indicate that adolescent males who expect the chance of being required to pay child support is high if one becomes a non-resident father or who has a…

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…

Sex Differences in Judgments of Male and Female Role Stereotypes.

ERIC Educational Resources Information Center

Getz, Sandra K.; Herman, Jeanne B.

This study tests whether or not there are sex differences in judgments of the success of various male and female lifestyles, and if so, what differential standards are applied to males and females. The most interesting result of this study is that college men and women use the same standards to judge the success of male lifestyles but different…

Puzzles in modern biology. I. Male sterility, failure reveals design

PubMed Central

Frank, Steven A.

2016-01-01

Many human males produce dysfunctional sperm. Various plants frequently abort pollen. Hybrid matings often produce sterile males. Widespread male sterility is puzzling. Natural selection prunes reproductive failure. Puzzling failure implies something that we do not understand about how organisms are designed. Solving the puzzle reveals the hidden processes of design. PMID:28004842

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...

How Sexual Orientation and Physical Attractiveness Affect Impressions of Males.

ERIC Educational Resources Information Center

Elman, Donald; And Others

Stereotyped impressions of male homosexuals and the underlying importance of sexuality in social attraction and perceptions were investigated. Male (N=80) and female (N=80) college students responded to either an attractive or an unattractive photo of a male stimulus person, who was identified to half of the subjects as a homosexual. Compared to…

Black Male Perspectives on Their Educational Experiences in High School

ERIC Educational Resources Information Center

Caton, Marcia Theresa

2012-01-01

This study examines the impact of the zero-tolerance policies on Black males' educational experiences and outcomes. Individual interviews were conducted with Black males who dropped out of high school. Using counter-storytelling within a critical race theory framework, Black males discussed the influence of the zero-tolerance policies on their…

Evaluation and treatment of male hypogonadism in primary care.

PubMed

Pickett, Kim Anne

2016-08-18

Male hypogonadism is increasing in prevalence, particularly in the older male population. Signs and symptoms associated with hypogonadism are often nonspecific and may be difficult to categorize. This article discusses parameters for screening patients at risk, reviews how to establish the diagnosis of primary or secondary male hypogonadism, and offers important considerations for treatment of patients with hypogonadism.

Male sex determination: insights into molecular mechanisms

PubMed Central

McClelland, Kathryn; Bowles, Josephine; Koopman, Peter

2012-01-01

Disorders of sex development often arise from anomalies in the molecular or cellular networks that guide the differentiation of the embryonic gonad into either a testis or an ovary, two functionally distinct organs. The activation of the Y-linked gene Sry (sex-determining region Y) and its downstream target Sox9 (Sry box-containing gene 9) triggers testis differentiation by stimulating the differentiation of Sertoli cells, which then direct testis morphogenesis. Once engaged, a genetic pathway promotes the testis development while actively suppressing genes involved in ovarian development. This review focuses on the events of testis determination and the struggle to maintain male fate in the face of antagonistic pressure from the underlying female programme. PMID:22179516

Male contraception: past, present and future.

PubMed

Payne, Christopher; Goldberg, Erwin

2014-01-01

Current contraceptive options available to men include withdrawal, condoms, and vasectomy, each of which has its own drawbacks. In this chapter we will describe the pros and cons for each, as well as methodological and product updates. Statistics from the U.S. Centers for Disease Control on acceptance and satisfaction will be included. Advances in vasectomy and reversal will be presented. Methods to develop new contraceptive technologies fall into two categories: hormonal and non-hormonal. Many targets and strategies have been proposed for non-hormonal male contraception within the testis. Targets include structural components in the testis, as well as enzymes, ion channels and other proteins specific to spermatozoa. Here we provide an overview of the spermatogenic mechanisms and proteins that have received research interest to date. We also discuss potential novel targets, such as ubiquitin specific proteases, that warrant greater research emphasis.

Health needs and concerns of male adolescents.

PubMed

Pinch, W J; Heck, M; Vinal, D

1986-01-01

Lifestyle factors established within the family help determine health-care functioning. Adolescents first may be challenged to meet their own health needs as freshmen in college. A 153-item questionnaire was utilized to examine concerns in the areas of alcohol and other drug use, auto safety, weight and dieting, smoking, sexuality, coping and stress, and selection and utilization of health-care services. One hundred fifty-nine male college students responded. Major problems with alcohol use, auto safety, weight control, stress and sexuality were identified. Positive lifestyle factors that were strongly supported included regular exercise, nonsmoking, regular medical and dental checkups, and the development of some support systems to cope with stress. Health-care services designated by respondents to meet their own needs were significantly different from those services they pointed out as needed for their peers.

Ritual male infant circumcision and human rights.

PubMed

Jacobs, Allan J; Arora, Kavita Shah

2015-01-01

Opponents of male circumcision have increasingly used human rights positions to articulate their viewpoint. We characterize the meaning of the term "human rights." We discuss these human rights arguments with special attention to the claims of rights to an open future and to bodily integrity. We offer a three-part test under which a parental decision might be considered an unacceptable violation of a child's right. The test considers the impact of the practice on society, the impact of the practice on the individual, and the likelihood of adverse impact. Infant circumcision is permissible under this test. We conclude that infant circumcision may be proscribed as violating local norms, even though it does not violate human rights.

Genetic basis of male sexual behavior.

PubMed

Emmons, Scott W; Lipton, Jonathan

2003-01-01

Male sexual behavior is increasingly the focus of genetic study in a variety of animals. Genetic analysis in the soil roundworm Caenorhabditis elegans and the fruit fly Drosophila melanogaster has lead to identification of genes and circuits that govern behaviors ranging from motivation and mate-searching to courtship and copulation. Some worm and fly genes have counterparts with related functions in higher animals and many more such correspondences can be expected. Analysis of mutations in mammals can potentially lead to insights into such issues as monogamous versus promiscuous sexual behavior and sexual orientation. Genetic analysis of sexual behavior has implications for understanding how the nervous system generates and controls a complex behavior. It can also help us to gain an appreciation of how behavior is encoded by genes and their regulatory sequences. Copyright 2003 Wiley Periodicals, Inc.

Male transvestite prostitutes and HIV risk.

PubMed Central

Elifson, K W; Boles, J; Posey, E; Sweat, M; Darrow, W; Elsea, W

1993-01-01

Human immunodeficiency virus (HIV)-1, syphilis, and hepatitis B prevalence and associated risk factors were assessed among male transvestite prostitutes. Structured street-level interviews were conducted with 53 respondents in Atlanta, Ga, from July 1990 through July 1991. Test results from serum samples revealed that 68% were seropositive for HIV-1, 81% had seromarkers for syphilis, and 80% had seromarkers for hepatitis B. Univariate logistic regression analysis indicated that seromarkers for syphilis and Black race were the primary factors associated with HIV-1 infection. The results show that transvestite prostitutes are a heterogenous population and distinct from nontransvestite prostitutes; specific outreach is thus needed. Targeted interventions should address the sexual and drug-use-related HIV risk behaviors of transvestite prostitutes. PMID:8427336

[Synchronous bilateral breast cancer in a male].

PubMed

García-Mejido, José Antonio; Delgado-Jiménez, Carmen; Gutiérrez-Palomino, Laura; Sánchez-Sevilla, Miguel; Iglesias-Bravo, Eva; Caballero-Fernández, Virginia

2013-01-01

male breast cancer is a disease with low incidence, which is further reduced when it comes to bilateral synchronous presentation. There are few published cases in recent years. The aim is to establish guidelines for the management of this disorder that is so rare. a 75-year-old with tumors in both breasts, which were completely resected with removal of palpable nodes. The histopathological study reported ductal carcinoma. The indicated treatment was adjuvant tamoxifen and radiotherapy. The patient is currently in a disease-free period. this is a rare disease, whose main treatment is surgery, hence the importance of early diagnosis. Most cases require adjuvant chemotherapy and radiotherapy because they are usually diagnosed at an advanced stage.

Monitoring Training Load in Indian Male Swimmers

PubMed Central

MAJUMDAR, PRALAY; SRIVIDHYA, SRI

2010-01-01

The present study was initiated to monitor the training load with the magnitude of impact on the hormone concentrations such as testosterone, cortisol and T/C (Testosterone/Cortisol) ratio during the three phases of training (i.e. preparatory, pre-competitive, and competitive phases) in Indian male swimmers preparing for the 2010 Commonwealth Games. Blood samples were collected at the end of each training phase and hormone concentration was determined by ELISA. Our results reveal that testosterone concentration and the T/C ratio significantly decreased and the cortisol concentration increased in the subsequent periodized cycle. Change in hormone concentration was associated with the intensity and duration of individual exercise sessions. The greatest performance enhancement was realized with the lowest plasma cortisol, highest testosterone, and a high T/C ratio. Monitoring of these hormones also have implications for identifying and preventing overreaching in swimmers. PMID:27182335

Aging and sex hormones in males

PubMed Central

Decaroli, Maria Chiara

2017-01-01

ABSTRACT Several large cohort studies have disclosed the trajectories of sex steroids changes overtime in men and their clinical significance. In men the slow, physiological decline of serum testosterone (T) with advancing age overlaps with the clinical condition of overt, pathological hypogonadism. In addition, the increasing number of comorbidities, together with the high prevalence of chronic diseases, all further contribute to the decrease of serum T concentrations in the aging male. For all these reasons both the diagnosis of late-onset hypogonadism (LOH) in men and the decision about starting or not T replacement treatment remain challenging. At present, the biochemical finding of T deficiency alone is not sufficient for diagnosing hypogonadism in older men. Coupling hypogonadal symptoms with documented low serum T represents the best strategy to refine the diagnosis of hypogonadism in older men and to avoid unnecessary treatments. PMID:27831823

The Effect of Male Confederate Presence, Betting, and Accuracy of Play on Males' Gambling on Blackjack

ERIC Educational Resources Information Center

McDougall, Casey L.; Terrance, Cheryl; Weatherly, Jeffrey N.

2011-01-01

Previous research suggests that the actions of a confederate can alter participants' gambling behavior. In the present experiment, male participants played Blackjack either alone or in the presence of a confederate. The confederate either quit early in the session or played for the entire session. Across sessions in which the confederate played…

Black, Male and Teaching: Exploring the Experiences, Perspectives and Teaching Practices of Black Male Teachers

ERIC Educational Resources Information Center

Fant, Tyrie Lavyal

2017-01-01

As America's K-12 student population continues to become more diverse, it is important that the ethnic background of the teacher population reflect this change. A crucial aspect of this diversification effort includes black male teachers. The purpose of this study was to explore and examine the experiences and perspectives of African American male…

[Influence of aging on male sexual health].

PubMed

Seisen, T; Rouprêt, M; Costa, P; Giuliano, F

2012-06-01

With the increase in life expectancy, men's sexual health has become a major concern for elderly couples. Erectile dysfunction (ED) is responsible for a 50 % decrease of sexually active men between 60 and 85. The aim of this study was to identify objective elements to evaluate the influence of age on male sexual health. Data on the effects of aging on men's sexual health have been explored in Medline and Embase using the MeSH keywords: prostate; sexuality and erectile dysfunction; aging. The articles were selected based on their methodology, relevance, date and language of publication. ED concerns 64 % of 70 years old patients and up to 77.5 % after 75 years. The screening of this pathology is based on standardized diagnostic tools. The most used of them remains the "International Index of Erectile function" which, in its simplified version with 5 items (IIEF-5 or SHIM), presents at the cutoff score of 21, a sensitivity of 98 %, a specificity of 88 % and a kappa index of 0.82. The ED is often responsible for a decrease in the quality of life for 60 % of elderly couples wishing to pursue sexual activity. Some diagnostic tools, such as the "Self-Esteem And Relationship" (SEAR) questionnaire or the "Sexual Experience Questionnaire" (SEX-Q) assess individual and couple satisfaction. Physiological aging seems to favor erection disorders by the development of an Androgen Deficiency of the Aging Male (ADAM) but pathological aging appears to be primarily responsible. Cardiovascular or neurological diseases and lower urinary tract symptoms (LUTS) are, with the polymedication, modifiable risk factors of ED to systematically screen in elderly subjects. Many diagnostic tools allow to detect ED and assess the impact on the quality of life of elderly men. The fundamental element of the management of ED is the research of modifiable risk factors including cardiovascular. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Male contraception: a clinically-oriented review.

PubMed

Kanakis, George A; Goulis, Dimitrios G

2015-01-01

Despite the variety of available female contraceptive methods, many pregnancies (~50%) are still undesired. Many men (>60%) want to participate equally with their partner in family planning; however, male contraceptive methods (MCMs) account for only 14% of those used worldwide and no pharmaceutical MCM is available so far. The only two MCMs currently available are condoms, which despite protecting against sexually transmitted diseases have high failure rates (~19%), and vasectomy, which though very efficient (99%) is poorly reversible (<50%). Among MCMs under investigation, male hormonal contraceptives (MHCs) are those that have come closest to commercialization. The action of MHCs relies on the disruption of spermatogenesis that exogenous androgen administration evokes by suppressing the hypophyseal-gonadal axis. Various regimens of androgens as monotherapy or in combination with progestins have been tested in clinical trials achieving a Pearl Index <1.0 (equal to that of the female oral contraceptive pill); however, concerns regarding the variable response rates observed (non-responders: 5-20%), the impracticality of parenteral administration and long-term prostate-associated or cardiovascular morbidity have deflected the interest of the pharmaceutical industry from further research. Non-hormonal contraception methods may be, at least theoretically, more specific by selectively disrupting spermatogenesis and sperm transport or fertilizing ability. Nevertheless, only a few have been tested in clinical trials (Reversible Inhibition of Sperm Under Guidance, RISUG, and Intra Vas Plugs); most of them are still in pre-clinical development or have been abandoned due to toxicity (gossypol). Consequently, until a reliable, safe and practical MCM is developed, women will continue to bear most of the contraception burden.

[Causes and management for male urethral stricture].

PubMed

Chen, Caifang; Zeng, Mingqiang; Xue, Ruizhi; Wang, Guilin; Gao, Zhiyong; Yuan, Wuxiong; Tang, Zhengyan

2018-05-28

To explore the etiology of male urethral stricture, analyze the therapeutic strategies of urethral stricture, and summarize the complicated cases.
 Methods: The data of 183 patients with urethral stricture were retrospectively analyzed, including etiology, obstruction site, stricture length, therapeutic strategy, and related complications.
 Results: The mean age was 49.7 years, the average course was 64.7 months, and the constituent ratio of 51 to 65 years old patients was 38.8% (71/183). The traumatic injury of patients accounted for 52.4% (96/183), in which the pelvic fracture accounted for 35.5% (65/183) and the straddle injury accounted for 16.9% (31/183). There were 54 cases of iatrogenic injury (29.5%). The posterior urethral stricture accounted for 45.9% (84/183), followed by the anterior urethral stricture (44.8%, 82/183) and the stenosis (6.6%, 12/183). A total of 99 patients (54.1%) received the end to end anastomosis, and 40 (21.9%) were treated with intracavitary surgery, such as endoscopic holmium laser, cold knife incision, endoscopic electroknife scar removal, balloon dilation, and urethral dilation. In the patients over 65-years old, the urethral stricture rate was 14.8% and the complication rate (70.4%) for transurethral resection of the prostate (TURP) was significantly higher than that of all samples (P<0.01).
 Conclusion: Both the etiology of male urethral stricture and the treatment strategy have changed and the incidence of traumatic and iatrogenic urethral stricture has increased in recent 3 years. The main treatment of urethral stricture has been transformed from endoscopic surgery into urethroplasty.

Adolescent males' orientation toward paternity and contraception.

PubMed

Marsiglio, W

1993-01-01

Data from a nationally representative sample of 1,880 young men aged 15-19 reveal that neighborhood quality, parental education, race or ethnicity, and attitudes about male gender roles are related to young men's attitudes toward an unplanned pregnancy and to their contraceptive experiences. Young men who live in poor neighborhoods are more likely to be pleased about an unplanned pregnancy than those who have better living conditions (12% vs. 2%) and are also more likely to view impregnating a woman as enhancing their masculinity (8% vs. 3%). Among men with average living conditions, 12% of black adolescents view fathering a child as enhancing their masculinity, compared with 6% of white adolescents; among those with very good living conditions, these proportions were 10% and 2%, respectively. Young men whose parents had less education and those who held traditional male gender role attitudes were also more likely than their counterparts to view fathering a child as enhancing their masculinity. Regarding contraceptive behavior, sexually active black men and Hispanic men were more likely than white men to have discussed contraception with their last partner; black men were more likely to have used an effective contraceptive method the last time they had intercourse; and black men were more likely to have used a condom at last intercourse. However, young men who were aware that they had been responsible for a previous pregnancy were less likely than those who reported no pregnancies to have used an effective contraceptive the last time they had intercourse. These same young men were also more likely to report that fathering a child would please them and enhance their masculinity.

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.

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

"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…

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

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

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.

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 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.

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.