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Sample records for male blue-black grassquit

  1. The importance of novelty: male-female interactions among blue-black grassquits in captivity.

    PubMed

    Dias, Raphael I; Oliveira, Rui F; Podos, Jeffrey; Macedo, Regina H

    2014-03-01

    Mate choice is a primary mechanism driving the evolution of sexually selected traits such as elaborate displays and ornaments. In a majority of taxa studied to date, females are seen to actively sample and evaluate multiple males, presumably to optimize mating opportunities. During this process females may encounter males both familiar and novel, a distinction that might influence how mate choice proceeds. Using a socially monogamous passerine, the blue-black grassquit (Volatinia jacarina), we studied how females respond to novel versus familiar ("paired") males, and how encounters with novel males influence subsequent interactions with their paired males. Additionally, we measured the hormonal response of males after visualizing their paired females interacting with novel males. We found that females were attentive to novel males irrespective of these males' phenotypic attributes, suggesting that in these interactions novelty is highly relevant. After exposure to novel males, females tended to respond aggressively towards their paired males; by contrast, the behaviour of males towards their paired females did not change. Moreover, we did not detect any hormonal responses of males to viewing their paired females interacting with novel males. Together these results suggest that the distinction between familiarity and novelty may hold special relevance for females in mate choice, a finding that bears upon our understanding of the evolution of extra-pair paternity and reproductive behaviour.

  2. Emasculation Blues: Black Male Teachers' Perspectives on Gender and Power in the Teaching Profession

    ERIC Educational Resources Information Center

    Brockenbrough, Ed

    2012-01-01

    Background/Context: Over the past decade, a growing chorus of educational stakeholders has called for the recruitment of more Black men into the American teaching profession, casting these men as ideal surrogate father figures for Black youth who may lack adult male role models in their families or communities. Although a small body of scholarly…

  3. Excited states and reduced and oxidized forms of a textile diazo dye, naphthol blue black. Spectral characterization using laser flash photolysis and pulse radiolysis studies

    NASA Astrophysics Data System (ADS)

    Nasr, Chouhaid; Vinodgopal, K.; Hotchandani, Surat; Chattopadhyay, A. K.; Kamat, Prashant V.

    1997-01-01

    The excited singlet and triplet states of a diazo textile dye (Naphthol Blue Black) have been investigated by pico and nanosecond flash photolysis. The excited singlet state shows a difference absorption maximum at 500 nm and has a lifetime of 25-30 ps in ethanol. The triplet excited state generated by triplet-triplet energy transfer shows an absorption maxima at 710-730 nm. The oxidized form as well as the reduced form of the diazo dye have been generated pulse radiolytically by reacting with azide and e aq radicals, respectively. Preliminary results of the photoelectrochemical irreversible reduction of Naphthol Blue Black in colloidal TiO 2 are also reported.

  4. Environmental photochemistry on semiconductor surfaces. Visible light induced degradation of a textile diazo dye, naphthol blue black, on TiO{sub 2} nanoparticles

    SciTech Connect

    Nasr, C.; Hotchandani, S.; Vinodgopal, K.; Fisher, L.; Chattopadhyay, A.K.; Kamat, P.V.

    1996-05-16

    Visible light induced degradation of the textile diazo dye Naphthol Blue Black (NBB) has been carried out on TiO{sub 2} semiconductor nanoparticles. Diffuse reflectance transient absorption and FTIR techniques have been used to elucidate the mechanistic details of the dye degradation. The failure of the dye to degrade on insulator surfaces such as Al{sub 2}O{sub 3} or in the absence of oxygen further highlights the importance of semiconducting properties of support material in controlling the surface photochemical processes. The primary event following visible light excitation is the charge injection from the excited dye molecule into the conduction band of the semiconductor TiO{sub 2}, producing the dye cation radical. This was confirmed by diffuse reflectance laser flash photolysis. The surface-adsorbed oxygen plays an important role in scavenging photogenerated electrons, thus preventing the recombination between the dye cation radical and photoinjected electrons. Diffuse reflectance FTIR study facilitated identification of reaction intermediates and end products of dye degradation. By comparison with the degradation products from other azo dyes such as Chromotrope 2B and Chromotrope 2R we conclude that the NBB is degraded to a colorless naphthaquinone-like end product. 41 refs., 9 figs.

  5. Comprehensive experimental and numerical investigations of the effect of frequency and acoustic intensity on the sonolytic degradation of naphthol blue black in water.

    PubMed

    Ferkous, Hamza; Merouani, Slimane; Hamdaoui, Oualid; Rezgui, Yacine; Guemini, Miloud

    2015-09-01

    In the present work, comprehensive experimental and numerical investigations of the effects of frequency and acoustic intensity on the sonochemical degradation of naphthol blue black (NBB) in water have been carried out. The experiments have been examined at three frequencies (585, 860 and 1140 kHz) and over a wide range of acoustic intensities. The observed experimental results have been discussed using a more realistic approach that combines the single bubble sonochemistry and the number of active bubbles. The single bubble yield has been predicted using a model that combines the bubble dynamics with chemical kinetics consisting of series of chemical reactions (73 reversible reactions) occurring inside an air bubble during the strong collapse. The experimental results showed that the sonochemical degradation rate of NBB increased substantially with increasing acoustic intensity and decreased with increasing ultrasound frequency. The numerical simulations revealed that NBB degraded mainly through the reaction with hydroxyl radical (OH), which is the dominant oxidant detected in the bubble during collapse. The production rate of OH radical inside a single bubble followed the same trend as that of NBB degradation rate. It increased with increasing acoustic intensity and decreased with increasing frequency. The enhancing effect of acoustic intensity toward the degradation of NBB was attributed to the rise of both the individual chemical bubble yield and the number of active bubbles with increasing acoustic intensity. The reducing effect of frequency was attributed to the sharp decrease in the chemical bubble yield with increasing frequency, which would not compensated by the rise of the number of active bubbles with the increase in ultrasound frequency.

  6. Counseling Males.

    ERIC Educational Resources Information Center

    Scher, Murray, Ed.

    1981-01-01

    Contains 16 articles about counseling males including: (1) gender role conflict; (2) sex-role development; (3) counseling adolescent, adult, and gay males; (4) teenage fathers; (5) female therapists and male clients; (6) career development; (7) hypermasculinity; (8) counseling physically abusive men, uncoupling men; (9) group therapy, men's…

  7. Condoms - male

    MedlinePlus

    Prophylactics; Rubbers; Male condoms; Contraceptive - condom; Contraception - condom; Barrier method - condom ... rubber Polyurethane Condoms are the only method of birth control for men that are not permanent. They can ...

  8. Male contraception.

    PubMed

    Wang, Christina; Swerdloff, Ronald S

    2002-04-01

    Currently approved male-directed contraceptive methods include condoms and vas occlusion. Vas occlusion is very effective but is intended to be non-reversible. Condoms have a relatively high failure rate, at least partially due to compliance problems and are not accepted by many couples. The only other male-oriented methods in clinical trials utilize the administration of testosterone alone or its combination with another gonadotropin-suppressing agent such as a progestin or a gonadotropin-releasing hormone antagonist. Studies published in the 1990s demonstrated that a testosterone-containing hormonal contraceptive method suppressed spermatogenesis to azoospermia in most men and severe oligozoospermia in the remaining. The contraceptive efficacy after treatment with testosterone alone was comparable to that of female hormonal methods. Having proven that reversible male contraception is a reality, present trials are attempting to identify the best androgen delivery system and the most effective androgen plus progestin preparation. It is likely that the first marketed male hormonal contraceptive method will be a long-acting (injectable or implant) combination of an androgen plus a progestin. Research is continuing to identify other target areas for male contraceptive development, including agents with post-testicular and epididymal sites of action.

  9. Male circumcision.

    PubMed

    2012-09-01

    Male circumcision consists of the surgical removal of some, or all, of the foreskin (or prepuce) from the penis. It is one of the most common procedures in the world. In the United States, the procedure is commonly performed during the newborn period. In 2007, the American Academy of Pediatrics (AAP) convened a multidisciplinary workgroup of AAP members and other stakeholders to evaluate the evidence regarding male circumcision and update the AAP's 1999 recommendations in this area. The Task Force included AAP representatives from specialty areas as well as members of the AAP Board of Directors and liaisons representing the American Academy of Family Physicians, the American College of Obstetricians and Gynecologists, and the Centers for Disease Control and Prevention. The Task Force members identified selected topics relevant to male circumcision and conducted a critical review of peer-reviewed literature by using the American Heart Association's template for evidence evaluation. Evaluation of current evidence indicates that the health benefits of newborn male circumcision outweigh the risks; furthermore, the benefits of newborn male circumcision justify access to this procedure for families who choose it. Specific benefits from male circumcision were identified for the prevention of urinary tract infections, acquisition of HIV, transmission of some sexually transmitted infections, and penile cancer. Male circumcision does not appear to adversely affect penile sexual function/sensitivity or sexual satisfaction. It is imperative that those providing circumcision are adequately trained and that both sterile techniques and effective pain management are used. Significant acute complications are rare. In general, untrained providers who perform circumcisions have more complications than well-trained providers who perform the procedure, regardless of whether the former are physicians, nurses, or traditional religious providers. Parents are entitled to factually correct

  10. [Male contraception].

    PubMed

    Demery, A

    1987-05-01

    Except for condoms, male contraception is very slightly utilized in France. Several male experimental methods are under study. A synthetic luteinizing hormone-releasing hormone (LHRH) analog has been used successfully in women and offers promise in men of blocking LHRH and thus blocking spermatogenesis. Several nonsteroid substances such an hypertensives and adrenaline would suppress follicle stimulating hormone and luteinizing hormone release, but are too toxic for use. The combination of 40 mcg ethinyl estradiol and 20 mg of methyltestosterone inhibits gonadotropin release and produces azoospermia in men, but at the risk of loss of libido, constant gynecomastia, and testicular atrophy. Several combinations of androgens and progestins have been evaluated. Percutaneous testosterone and medroxyprogesterone acetate appears to be the most effective, with good metabolic tolerance and maintenance of libido and sexual performance. Injections of inhibine, a testicular factor that controls secretion of follicle stimulating hormone by feedback, offer promise of suppressing spermatogenesis without affecting other systems. Numerous substances are known to inhibit spermatogenesis but are to toxic for use or entail an unacceptable loss of libido. Gossypol has been employed as a contraceptive by the Chinese for its action in inhibiting protein synthesis, but it is known to have serious secondary effects. Among male methods currently in use, the condom had a Pearl index of .4-1.6 in the most recent British studies. Coitus interruptus can seriously interfere with sexual pleasure and has a failure rate of 25-30%. Vasectomy is safe, effective, and easy to perform, but is not a reversible method. The combination of 20 mg of medroxyprogesterone acetate in 2 daily doses and 100 mg of testosterone applied in an abdominal spray has given very promising results in 2 small studies in France and merits further development and diffusion.

  11. Male catheterization.

    PubMed

    Hadfield-Law, L

    2001-10-01

    The insertion of catheters into male emergency patients is fairly common practice and is associated with a worryingly high rate of infection. Everyday pressures within the department, along with the added stress of resuscitation can result in inappropriately trained or skilled staff undertaking this procedure. The issue of gender and whether female nurses should catheterize male patients may also affect this vulnerable group of patients. Acquiring the psychomotor skills of inserting a urethral catheter is only one part of preparation for practice. Emergency nurses must know when and when not to resort to catheterization. Choosing the type and size of catheter requires careful judgment. What will you do if insertion proves difficult? Prevention of infection is of paramount importance and there are an increasing number of evidence-based sources of information, which are crucial to formulating procedures and informing every day practice. In the pressured surroundings of A&E departments, it is easy to ignore the vulnerability of men requiring catheterization, both from a physical and psychological point of view. Making the effort to explain the procedure, listen to questions and concerns and record relevant details in the notes, will take only a few extra moments. There is no doubt that urinary catheterization is not without complications. It is associated with significant morbidity and occasionally, mortality.

  12. [Male contraception].

    PubMed

    Demoulin, A

    1984-04-01

    Among the reasons why male hormonal contraception has lagged behind female methods are the necessity of preserving virility, the fact that spermatogenesis is a continuous process, the need to control secondary effects and toxicity, and the requirement that modes of administration be acceptable to both partners. Among currently available reversible mehtods, withdrawal is undoubtedly the most ancient. It is still widespread but cannot be recommended because of its limited effectiveness. The condom is used by about 10% of couples worldwide as a principal or temporary method, but its inter-ference with sensation has limited its acceptance. Condoms are nevertheless highly effective when used with a spermicide. Various androgens are currently under investigation. High doses of testosterone can induce azoospermia without affecting libido but their side effects may be serious. The use of combinations of steroids permits doses to be reduced and offers promise for the future. The combination of oral medroxyprogesterone acetate and percutaneous testosterone is one of the better approaches; the combination is effective and nontoxic but has the disadvantage of percutaneous administration. Gossypol, a pigment extracted from the cotton plant, has been used as a contraceptive in China with a reported efficacy of 99.89%, recovery of fertility within 3 months, and no effect on future fertility. However, its toxicity appears to be significant in the animal and its reversibility is uncertain. A search is on for analogs which would preserve the contraceptive effects while eliminating toxic effects. Several gonadotropin releasing hormone (GnRH) analogs under investigation for their interference with spermatogenesis have given promising results. Several chemicals tested for contraceptive effects have had unacceptably high toxicity. Chinese investigators have reported good results with various physical methods of interfering with sperm production, but their reversibility and innocuity

  13. Male to male transmission of supernumerary nipples.

    PubMed

    Tsukahara, M; Uchida, M; Uchino, S; Fujisawa, R; Kamei, T; Itoh, T

    1997-03-17

    We report on a father and his son with supernumerary nipples. No male-to-male transmission has previously been described with this trait. This observation confirms that this trait is inherited in an autosomal dominant fashion.

  14. Male Reproductive System

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Male Reproductive System KidsHealth > For Parents > Male Reproductive System Print A ... understand your son's reproductive health. continue About the Male Reproductive System Most species have two sexes: male and female. ...

  15. 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 by looking ...

  16. Consistent male-male paternity differences across female genotypes.

    PubMed

    Sherman, Craig D H; Wapstra, Erik; Olsson, Mats

    2009-04-23

    In a recent paper, we demonstrated that male-female genetic relatedness determines male probability of paternity in experimental sperm competition in the Peron's tree frog (Litoria peronii), with a more closely related male outcompeting his rival. Here, we test the hypothesis that a male-male difference in siring success with one female significantly predicts the corresponding difference in siring success with another female. With male sperm concentration held constant, and the proportion of viable sperm controlled statistically, the male-male difference in siring success with one female strongly predicted the corresponding difference in siring success with another female, and alone explained more than 62 per cent of the variance in male-male siring differences. This study demonstrates that male siring success is primarily dictated by among-male differences in innate siring success with less influence of male-female relatedness.

  17. 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.

  18. Chlamydial infections - male

    MedlinePlus

    ... Have sex without wearing a male or female condom Have more than one sexual partner Use drugs ... to have sexual contact, use latex or polyurethane condoms. Remember to: Use condoms for all vaginal, anal, ...

  19. Male Reproductive System

    MedlinePlus

    ... gamete, the egg or ovum, meet in the female's reproductive system to create a baby. Both the male and female reproductive systems are essential for reproduction. Humans pass certain characteristics ...

  20. Oxidative stress & male infertility.

    PubMed

    Makker, Kartikeya; Agarwal, Ashok; Sharma, Rakesh

    2009-04-01

    The male factor is considered a major contributory factor to infertility. Apart from the conventional causes for male infertility such as varicocoele, cryptorchidism, infections, obstructive lesions, cystic fibrosis, trauma, and tumours, a new and important cause has been identified: oxidative stress. Oxidative stress is a result of the imbalance between reactive oxygen species (ROS) and antioxidants in the body. It is a powerful mechanism that can lead to sperm damage, deformity and eventually, male infertility. This review discusses the physiological need for ROS and their role in normal sperm function. It also highlights the mechanism of production and the pathophysiology of ROS in relation to the male reproductive system and enumerate the benefits of incorporating antioxidants in clinical and experimental settings.

  1. Male Breast Cancer

    MedlinePlus

    ... hasn't spread beyond your breast tissue. Radiation therapy Radiation therapy uses high-energy beams to kill ... option for men with advanced breast cancer. Hormone therapy Most men with male breast cancer have tumors ...

  2. Techniques of male circumcision.

    PubMed

    Abdulwahab-Ahmed, Abdullahi; Mungadi, Ismaila A

    2013-01-01

    Male circumcision is a controversial subject in surgical practice. There are, however, clear surgical indications of this procedure. The American Academy of Pediatrics (AAP) recommends newborn male circumcision for its preventive and public health benefits that has been shown to outweigh the risks of newborn male circumcision. Many surgical techniques have been reported. The present review discusses some of these techniques with their merits and drawbacks. This is an attempt to inform the reader on surgical aspects of male circumcision aiding in making appropriate choice of a technique to offer patients. Pubmed search was done with the keywords: Circumcision, technique, complications, and history. Relevant articles on techniques of circumcision were selected for the review. Various methods of circumcision including several devices are in use for male circumcision. These methods can be grouped into three: Shield and clamp, dorsal slit, and excision. The device methods appear favored in the pediatric circumcision while the risk of complications increases with increasing age of the patient at surgery.

  3. Hyperprolactinaemia in male diabetics.

    PubMed Central

    Mooradian, A. D.; Morley, J. E.; Billington, C. J.; Slag, M. F.; Elson, M. K.; Shafer, R. B.

    1985-01-01

    We recently investigated two patients with diabetes and elevated serum prolactin levels in whom no cause of hyperprolactinaemia could be found. For this reason we measured fasting serum prolactin levels in 72 diabetic males and compared the results with those of 63 healthy males and 90 nondiabetic males attending an Impotence Clinic. The diabetic group had significantly higher serum prolactin levels (13.1 +/- 0.9 ng/ml) than the two control groups (9.9 +/- 0.6 ng/ml for normal males and 7.7 +/- 0.3 ng/ml for the non-diabetic impotent group). Eighteen percent of the diabetics studied had serum prolactin levels above the normal range for males (greater than 20 ng/ml). There was no correlation between serum prolactin levels and duration of diabetes, glycosylated haemoglobin level or presence of clinically apparent retinopathy. The correlation between serum prolactin level and fasting plasma glucose was weak though statistically significant (r = 0.26, P less than 0.05). PMID:3991396

  4. 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...

  5. Stages of Male Breast Cancer

    MedlinePlus

    ... Breast & Gynecologic Cancers Breast Cancer Screening Research Male Breast Cancer Treatment (PDQ®)–Patient Version General Information about Male Breast Cancer Go to Health Professional Version Key Points Male ...

  6. Male Breast Cancer

    PubMed Central

    Yalaza, Metin; İnan, Aydın; Bozer, Mikdat

    2016-01-01

    Male breast cancer (MBC) is a rare disease, accounting for less than 1% of all breast cancer diagnoses worldwide. Although breast carcinomas share certain characteristics in both genders, there are notable differences. Most studies on men with breast cancer are very small. Thus, most data on male breast cancer are derived from studies on females. However, when a number of these small studies are grouped together, we can learn more from them. This review emphasizes the incidence, etiology, clinical features, diagnosis, treatment, pathology, survival, and prognostic factors related to MBC.

  7. 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

  8. Eating Disordered Adolescent Males.

    ERIC Educational Resources Information Center

    Eliot, Alexandra O.; Baker, Christina Wood

    2001-01-01

    Described a sample of eating disordered adolescent males who were seen for treatment at Boston Children's Hospital Outpatient Eating Disorders Clinic. Findings suggest the idea that clinicians, coaches, peers, and family should encourage young men to share concerns about body image and weight at an earlier, less severe juncture, with the assurance…

  9. 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

  10. Minority Male Afterschool Program.

    ERIC Educational Resources Information Center

    Dalton, Herbert F., Jr.

    Through a program called the Minority Male Afterschool Program (MMAP), college students at Mississippi Valley State University in Itta Bena (Mississippi) are working one-on-one with high school students. The MMAP is an enrichment program that encourages at-risk African American students aged 12 to 19 to complete high school and pursue…

  11. Male breast cancer.

    PubMed

    Reis, Leonardo Oliveira; Dias, Fernando Gf; Castro, Marcos As; Ferreira, Ubirajara

    2011-06-01

    Male breast cancer (MBC) is a rare disease. However, as global populace ages, there is a trend to MBC increasing. Although aetiology is still unclear, constitutional, environmental, hormonal (abnormalities in estrogen/androgen balance) and genetic (positive family history, Klinefelter syndrome, mutations in BRCA1 and specially BRCA2) risk factors are already known. Clinic manifestation is painless hard and fixed nodule in the subareolar region in 75% of cases, with nipple commitment earlier than in women. Breast cancer has similar prognostic factors in males and females, among which axillary adenopathy (present in 40-55% cases) is the most important one. Although mammography, ultrasonography and scintigraphy can be useful tools in diagnosis; clinical assessment, along with a confirmatory biopsy, remains the main step in the evaluation of men with breast lesions. Infiltrating ductal carcinoma is the most frequent histological type. The established standard of care is modified radical mastectomy followed by tamoxifen for endocrine-responsive positive disease, although other options are being explored. While similarities between breast cancer in males and females exist, it is not appropriate to extrapolate data from female disease to the treatment of male. There is a need for specific multi-institutional trials to better understanding of clinicopathologic features and establishment of optimal therapy for this disease.

  12. 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…

  13. 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…

  14. Male rat sexual behavior.

    PubMed

    Agmo, A

    1997-05-01

    The male rat's sexual behavior constitutes a highly ordered sequence of motor acts involving both striate and smooth muscles. It is spontaneously displayed by most adult made rats in the presence of a sexually receptive female. Although the behavior is important for the survival of the species it is not necessary for survival of the individual. In that way it is different from other spontaneous behaviors such as eating, drinking, avoidance of pain, respiration or thermoregulation. Among other things, this means that it is difficult to talk about sexual deprivation or need. Nevertheless, studies of male sex behavior distinguish sexual motivation (the ease by which behavior is activated, "libido") from the execution of copulatory acts (performance, "potency") (Meisel, R.L. and Sachs, B.D., The physiology of male sexual behavior. In: E. Knobil and J.D. Neill (Eds.), The Physiology of Reproduction, 2nd Edn., Vol. 2, Raven Press, New York, 1994, pp. 3-105 [13]). The hormonal control of male sexual behavior has been extensively studied. It is clear that steroid hormones, androgens and estrogens, act within the central nervous system, modifying neuronal excitability. The exact mechanism by which these hormones activate sex behavior remains largely unknown. However, there exists a considerable amount of knowledge concerning the brain structures important for sexual motivation and for the execution of sex behavior. The modulatory role of some non-steroid hormones is partly known, as well as the consequences of manipulations of several neurotransmitter systems.

  15. 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…

  16. 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.

  17. Newborn male circumcision

    PubMed Central

    Sorokan, S Todd; Finlay, Jane C; Jefferies, Ann L

    2015-01-01

    The circumcision of newborn males in Canada has become a less frequent practice over the past few decades. This change has been significantly influenced by past recommendations from the Canadian Paediatric Society and the American Academy of Pediatrics, who both affirmed that the procedure was not medically indicated. Recent evidence suggesting the potential benefit of circumcision in preventing urinary tract infection and some sexually transmitted infections, including HIV, has prompted the Canadian Paediatric Society to review the current medical literature in this regard. While there may be a benefit for some boys in high-risk populations and circumstances where the procedure could be considered for disease reduction or treatment, the Canadian Paediatric Society does not recommend the routine circumcision of every newborn male. PMID:26435672

  18. Male Genital Lichen Sclerosus

    PubMed Central

    Bunker, Christopher Barry; Shim, Tang Ngee

    2015-01-01

    Male genital lichen sclerosus (MGLSc) is a chronic inflammatory skin disease responsible for male sexual dyspareunia and urological morbidity. An afeared complication is squamous cell carcinoma (SCC) of the penis. The precise etiopathogenesis of MGLSc remains controversial although genetic, autoimmune and infective (such as human papillomavirus (HPV) hepatitis C (HCV), Epstein-Barr virus (EBV) and Borrelia) factors have been implicated: Consideration of all the evidence suggests that chronic exposure of susceptible epithelium to urinary occlusion by the foreskin seems the most likely pathomechanism. The mainstay of treatment is topical ultrapotent corticosteroid therapy. Surgery is indicated for cases unresponsive to topical corticosteroid therapy, phimosis, meatal stenosis, urethral stricture, carcinoma in situ (CIS) and squamous cell carcinoma. PMID:25814697

  19. Male only Systemic Lupus

    PubMed Central

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

    2010-01-01

    Systemic lupus erythematosus (SLE) is more common among women than men with a ratio of about 10 to 1. We undertook this study to describe familial male SLE within a large cohort of familial SLE. SLE families (two or more patients) were obtained 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 five 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 five families with only-male SLE patients had a statistically increased rate of positive ANA 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 were White women with SLE but there was no difference in this likelihood among Black men. These data suggest genetic susceptibility factors that act only in men. PMID:20472921

  20. 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

  1. 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.

  2. Blue-Black or White-Gold? Early Stage Processing and the Color of 'The Dress'

    PubMed Central

    Rabin, Jeff

    2016-01-01

    Purpose In Feb 2015 an image of a dress posted on Tumblr triggered an internet phenomenon: Is the Dress blue and black (BB) or white and gold (WG)? Many claim BB and others insist WG while the true colors are BB. The prevailing theory is that assumptions about the illuminant govern perception of the Dress with WG due to bluish lighting and BB due to yellowish. Our purpose was to determine if early stage optical, retinal and/or neural factors also impact perception of the Dress. Methods Thirty-nine subjects were categorized as BB or WG based on their initial perception of the Dress and their perception reported when viewing the Dress on iPhone 5, iPad, and 22” LCD displays. Macular pigment optical density (MPOD) measured with the QuantifEye™ MPS II and visual brainwaves (VEPs) in response to brief presentations of a transparency of the Dress illuminated by a flashing light were measured on each subject and compared between BB and WG groups. Additionally, CIE chromaticity (color) and luminance (brightness) were measured from multiple areas of the Dress image to determine cone stimulation and contrast. Results Mean MPOD was higher in the WG group (0.49) vs. the BB (0.41, p = 0.04) and median values were higher as well (WG = 0.46, BB = 0.36, p = 0.03). There was no difference in VEP amplitude between groups (p > 0.85) but mean VEP latency was longer in WG (130 msec.) vs. the BB group (107 msec., p = 0.0005). Colorimetry of the Dress showed significantly greater stimulation of blue cones (contrast = 73%) vs. red and green sensitive cones (contrast = 13%). Conclusions Our findings indicate that observers with denser MPOD may be predisposed to perceive the Dress as WG due to great absorption of blue light by the macular pigment. Moreover, the novel, substantial stimulation of blue cones by the Dress may contribute to ambiguity and dichotomous perception since the blue cones are so sparse in the retina. Finally, the delayed WG VEPs indicate distinct neural processing in perception of the consistent with fMRI evidence that the WG percept is processed at higher cortical levels than the BB. These results do not fully explain the dichotomous perception of the Dress but do exemplify the need to consider early stage processing when elucidating ambiguous percepts and figures. PMID:27580077

  3. Male breast carcinoma

    PubMed Central

    Meguerditchian, Ari-Nareg; Falardeau, Maurice; Martin, Ginette

    2002-01-01

    Objective To review the epidemiology, presentation, diagnosis, molecular genetics, treatment and prognosis of male breast cancer. Data sources Articles, written in English or French, selected from the Medline database (1966 to January 2001), corresponding to the key words “male breast cancer,” according to the following criteria: covering institutional experience or comparing diagnostic and treatment modalities, and epidemiologic or general reviews. Study selection Of 198 articles found 50 fulfilled the review criteria. Data synthesis Risk factors included advanced age, a positive family history, Jewish origin, black race, excess exposure to female hormones (Klinefelter’s syndrome), environmental exposure (irradiation), alcohol, obesity, higher socioeconomic or higher educational status and childlessness. Gynecomastia remains a controversial factor, this term being used for both a histologic reality and a physical finding. Advanced disease is characterized by pain, bloody discharge and skin ulceration. There is no definitive diagnostic algorithm. Experience with male breast mammography is limited, and imaging is less informative for patients under 50 years of age. Fine-needle aspiration tends to overestimate the rate of malignancy. The commonest histologic finding is infiltrating ductal adenocarcinoma. Treatment includes modified radical mastectomy, followed by cyclophosphamide–methotrexate–5-fluo-rouracil or 5-fluorouracil–Adriamycin–cyclophosphamide chemotherapy for disease of stage II or greater. Radiotherapy does not seem to add any benefit. The disease is highly receptor-positive; however, many patients discontinue tamoxifen due to side effects. The most important prognostic factors are tumour size, lymphatic invasion and axillary node status. Conclusions Because of the low incidence of male breast cancer, advances will be obtained mainly with the rapid transfer of newly gained knowledge in female mammary neoplasia. The increased use of adjuvant

  4. [Orchitis and male infertility].

    PubMed

    Schuppe, H-C; Pilatz, A; Hossain, H; Meinhardt, A; Bergmann, M; Haidl, G; Weidner, W

    2010-05-01

    Infections and inflammations of the genital tract are considered the most frequent causes of reduced male fertility, but conclusive epidemiological data are not available. In view of the exposure of germ cells to pathogenic components as well as the cells and mediators involved in the inflammatory processes, irreversible damage to spermatogenesis and corresponding decline of ejaculate quality are to be expected, particularly in cases of chronic orchitis. While the consequences of orchitis and epididymo-orchitis that exhibit clinical symptoms due to systemic or local infections are well known, including testicular atrophy and complete loss of fertility, those cases of inflammatory reactions of the testicles that manifest an asymptomatic or subclinical course, or are not even due to an infection, have received little attention until now. However, systematic histopathological analyses have shown a high prevalence of asymptomatic inflammatory reactions in testicular biopsies from infertile men. The mostly focal lymphocytic infiltrates correlate with the degree of damage to spermatogenesis and corresponding clinical and endocrinological parameters of testicular function. Noninvasive diagnostic techniques are not yet available so that chronic asymptomatic inflammations of the testicles as the primary cause or cofactor of male fertility disorders are underestimated. Except for administration of pathogen-specific antibiotics, treatment recommendations are to a large extent still lacking.

  5. Male hormonal contraceptives.

    PubMed

    Amory, J K

    2006-06-01

    Efforts are underway to develop additional forms of contraception for men. The most promising approach to male contraceptive development involves the administration of exogenous testosterone (T). When administered to a man, T functions as a contraceptive by suppressing the secretion of luteinizing hormone and follicle-stimulating hormone from the pituitary, thereby depriving the testes of the signals required for spermatogenesis. After 2-3 months of treatment, low levels of these gonadotropins lead to markedly decreased sperm counts and effective contraception in a majority of men. Hormonal contraception with exogenous T has proven to be free from serious adverse effects and is well tolerated by men. In addition, sperm counts uniformly normalize when the exogenous T is discontinued. Thus, male hormonal is safe, effective and reversible; however, spermatogenesis is not suppressed to zero in all men, meaning that some diminished potential for fertility persists. Because of this recent studies have combined T with progestogens and/or gonadotropin-releasing antagonists to further suppress pituitary gonadotropins and optimize contraceptive efficacy. Current combinations of T and progestogens completely suppress spermatogenesis without severe side effects in 80-90% of men, with significant suppression in the remainder of individuals. Recent trials with newer, long-acting forms of injectable T, which can be administered every 8 weeks, combined with progestogens, administered either orally or by long-acting implant, have yielded promising results and may soon result in the marketing of a safe, reversible and effective hormonal contraceptive for men.

  6. 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

  7. Sport and male sexuality.

    PubMed

    Sgrò, P; Di Luigi, L

    2017-03-22

    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.

  8. [Obesity and male fertility].

    PubMed

    Martini, Ana C; Molina, Rosa I; Ruiz, Rubén D; Fiol de Cuneo, Marta

    2012-01-01

    Obesity and male infertility have increased in the last decades; therefore, a possible association between these pathologies has been explored. Studies inform that obesity may affect fertility through different mechanisms, which alltogether could exert erectile dysfunction and/or sperm quality impairment. These include: 1) hypothalamic-pituitary-testicular (HPG) axis malfunction: obese hormonal profile is characterized by reduction of testosterone, gonadotrophins, SHBG and/or inhibin B concentrations (marker of Sertoli cells function) and hyperestrogenemy (consequence of aromatase overactivity ascribed to adipose tissue increase); 2) increased release of adipose-derived hormones: leptin increase could be responsible for some of the alterations on the HPG axis and could also exert direct deleterious effects on Leydig cells physiology, spermatogenesis and sperm function; 3) proinflammatory adipokines augmentation, higher scrotal temperature (due to fat accumulation in areas surrounding testes) and endocrine disruptors accumulation in adiposites, all of these responsible for the increase in testes oxidative stress and 4) sleep apnea, frequent in obese patients, suppresses the nocturnal testosterone rise needed for normal spermatogenesis. Finally, although controversial, all the above mentioned factors could comprise gametes quality; i.e. decrease sperm density and motility and increase DNA fragmentation, probably disturbing spermatogenesis and/or epididymal function. In summary, although obesity may impair male fertility by some/all of the described mechanisms, the fact is that only a small proportion of obese men are infertile, probably those genetically predisposed or morbidly obese. Nevertheless, it is likely that because the incidence of obesity is growing, the number of men with reduced fertility will increase as well.

  9. Coalitions and male-male behavior in Alouatta palliata.

    PubMed

    Dias, Pedro Américo D; Rangel-Negrin, Ariadna; Veà, Joaquim J; Canales-Espinosa, Domingo

    2010-01-01

    Coalitions influence the establishment and maintenance of social relationships among males in primate species. In this study, we compare the social behavior of males between two groups of Alouatta palliata: a group that was recently taken over by a coalition of two males (Mt), and a group that had a stable composition for at least 9 months (Rh). We predicted that coalition partners would be more cooperative and less competitive than dyads formed by immigrant and long-term resident males, and dyads formed by long-term resident males. Additionally, we predicted that these dyadic trends should be reflected in more competition and less cooperation in the group that was taken over. As predicted, the coalition partners of Mt showed the highest levels of cooperation among all dyads and the second lowest rate of agonism. Cooperation was higher in the group that had a stable composition. Results from this study suggest that the social relationships of male mantled howlers vary as a function of familiarity between males and that in the context of coalitionary takeovers, coalitionary males are highly cooperative. Cooperation is lower in groups recently taken over and competition is more intense, perhaps as a consequence of the process of establishment and reorganization of power relationships within some dyads. In the future, we must determine the frequency of coalitionary takeovers in this population and assess its ultimate consequences for male-male social relationships.

  10. Male-male interactions and mating kinetics in Drosophila.

    PubMed

    Wallace, B

    1990-05-01

    Male-male interaction (K) has been estimated from data on the attrition rate of virgin females per minute in a study of the mating kinetics in Drosophila. K is expressed as the time males expend on other males relative to that expended while searching for, courting, and copulating with females. The value of K in these studies ranged from 0 (approximately) to .695; it was affected both by strain (sepia or ebony D. melanogaster and wild-type D. simulans) and by size of the mating chamber. Host-parasitoid models of ecologists appear to be appropriate for examining mating kinetics in Drosophila.

  11. 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

  12. Dermatoglyphic pattern in male infertility.

    PubMed

    Sontakke, B R; Talhar, S; Ingole, I V; Shende, M R; Pal, A K; Bhattacharaya, T

    2013-06-01

    Dermatoglyphics in infertile male patients were studied and compared with that of age matched controls to see whether any specific dermatoglyphic pattern exists in infertile male patients. Infertile male patients with abnormal semen profile were referred to Cytogenetic Laboratory for karyotyping. We selected twenty-four infertile male patients with abnormal semen profile. Out of twenty-four infertile male patients, nineteen were with normal Karyotype and five patients were with abnormal Karyotype. Loop was the commonest pattern observed in the infertile male patients. All these fingertip and palmar dermatoglyphic findings were compared with that of result on finger and palmar dermatoglyphics of equal number of age matched controls. Statistical evaluation was done with software "EPI- info, version-6.04 d". Infertile males had reduced number of loops as compared to that of controls which was statistically significant. Total whorls were increased in infertile male patients as compared to that of controls which was statistically insignificant. Percentage of true palmar pattern in I 3 and I 4 areas was reduced in infertile male patients as compared to that of controls which was statistically insignificant.

  13. 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.

  14. "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…

  15. 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…

  16. Educating Black Males with Dyslexia

    ERIC Educational Resources Information Center

    Robinson, Shawn Anthony

    2013-01-01

    Much of the scholarship on Black males in the educational literature focuses on the achievement gap; their underrepresentation in gifted and advanced placement programs; their overrepresentation in special education programs and their high rates of school suspensions and expulsions. Although overrepresented in special education, Black males with…

  17. 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…

  18. [Clinical characteristics of male osteoporosis].

    PubMed

    Yamauchi, Mika; Sugimoto, Toshitsugu

    2016-07-01

    As men are less likely than women to develop osteoporosis, male osteoporosis remains poorly understood. However, elderly men have a clearly reduced bone mineral density and increased risk for fractures. In Japan, one in four patients with osteoporosis is male. Male osteoporosis is associated with not only reduction in androgen, but also estrogen, and differs from postmenopausal osteoporosis in that decreased bone formation is involved and that age-related changes in cortical bone structure and perforation of the trabeculae of cancellous bone are unlikely to occur. The proportion of secondary osteoporosis is higher for men than women;therefore, differential diagnosis is important in the diagnosis of male osteoporosis. In addition, it is recommended that bone mineral density be measured at the femoral neck or total hip in men. Men have a worse prognosis following fractures than women, and management of male osteoporosis is highly important for extending healthy life expectancy.

  19. Males disposed to commit rape.

    PubMed

    Freund, K; Scher, H; Racansky, I G; Campbell, K; Heasman, G

    1986-02-01

    The hypothesis that the preferential rape pattern belongs among the courtship disorders like voyeurism, exhibitionism, and toucheurism was tested. The study consisted of two experiments. The first compared 11 rape-prone males, who were most likely afflicted with the preferential rape pattern, with 11 sexually normal controls on penile response to narratives that depicted scenes in which the individual engaged in behavior typical of voyeurs, exhibitionists, or toucheurs. Narratives depicting normal tactile interaction (short of intercourse) with a genuinely participating woman, normal intercourse, and sexually neutral scenes were also presented. The rape-prone males responded more to the voyeuristic situations than did the controls. The standing of the normal intercourse situations on the scale of erotic value, relative to the other above-mentioned situations, was lower for the rape-prone males than for the normal controls. A second experiment compared 12 rape-prone males, who most likely demonstrated the preferential rape pattern, with 12 males with (other) courtship disorders and 12 sexually normal controls. Penile response to narratives depicting the individual involved in pretactile erotic activity, in tactile sexual activity short of intercourse, or in having intercourse was compared. Each situation was presented in two modalities depicting either a genuinely participating woman or a woman fearful of the individual. The penile responses of the rape-prone males, as well as those of males with other courtship disorders, differentiated less between sexual interaction with a fearful woman and such interaction with a participating woman than did the penile responses of normal controls. There was no significant difference in this respect between the rape-prone males and males with other courtship disorders.

  20. Male Reproductive System (For Teens)

    MedlinePlus

    ... gamete, the egg or ovum , meet in the female's reproductive system to create a new individual. Both the male and female reproductive systems are essential for reproduction. Humans, like other organisms, ...

  1. How Effective Is Male Contraception?

    MedlinePlus

    ... Trials Resources and Publications How effective is male contraception? Skip sharing on social media links Share this: ... health care providers to determine which method of birth control is best for them. For men, methods of ...

  2. Male Reproductive System (For Teens)

    MedlinePlus

    ... español Sistema reproductor masculino All living things reproduce. Reproduction — the process by which organisms make more organisms ... male and female reproductive systems are essential for reproduction. Humans, like other organisms, pass certain characteristics of ...

  3. MECP2 mutations in males

    PubMed Central

    Villard, Laurent

    2007-01-01

    Rett syndrome (RS; MIM 312750) is a severe neurological disorder affecting exclusively females. Its prevalence is about 1 in 10 000 female births, and it is a prominent cause of profound mental handicap in women. RS is caused by mutations in the X‐linked methyl CpG‐binding protein 2 (MECP2) gene. These mutations were initially thought to be lethal in males. However, MECP2 mutations are now frequently identified in mentally retarded male patients. The frequency of disease‐causing MECP2 mutations in this population is between 1.3% and 1.7%. Surprisingly, MECP2 mutations in males are responsible for a wide spectrum of neurological disorders, ranging from mild mental retardation to severe neonatal encephalopathy. The aim of this review is to describe the nature of the MECP2 mutations identified in male patients to date and their associated phenotypes. PMID:17351020

  4. Molecular biology of male infertility.

    PubMed

    Feng, H L

    2003-01-01

    About 15% of couples have reduced fertility and in approximately one-half of all cases the reason is male infertility, usually of genetic origin. Thus, in the context of research in genes involved in reproduction and sex determination, genetic anomalies in gametogenesis are being extensively studied. The most frequent pathogenic causes of male infertility are Y-chromosomal microdeletions (8-15%) in the long arm of the Y chromosome, which, by loss of specific DNA segments, leads to loss of vital genes for sperm production. Infertile men, who attend infertility clinics, rise to 15% among those with azoospermia or spermatogenesis problem. The new technique of intracytoplasmic sperm injection has allowed many infertile men to achieve their dreams of fatherhood. However, the spermatogenic defect is genetic anomalies, which might be a potential risk of transmitting this defect to future offspring. Therefore, genetic counseling of all couples with the diagnosis of male infertility is recommended before their enrolment in intrauterine insemination, in vitro fertilization, and intracytoplasmic sperm injection. The important role of genetic abnormalities in the causation of human male infertility is increasingly recognized. While much remains to be learned in this fast-moving field, considerable progress has been made in the clinical delineation of genetic forms of male infertility and in the characterization of the responsible genes and their mutations or deletions. This review should provide insight into the understanding of parthenogenesis of male infertility in the human.

  5. Leptin pharmacokinetics in male mice

    PubMed Central

    Dobos, Robin C; Agnew, Linda L; Smart, Neil A; McFarlane, James R

    2017-01-01

    Pharmacokinetics of leptin in mammals has not been studied in detail and only one study has examined more than one time point in non-mutant mice and this was in a female mice. This is the first study to describe leptin distribution over a detailed time course in normal male mice. A physiologic dose (12 ng) of radiolabelled leptin was injected into adult male mice via the lateral tail vein and tissues were dissected out and measured for radioactivity over a time course of up to two hours. Major targets were the digestive tract, kidneys, skin and lungs. The brain was not a major target, and 0.15% of the total dose was recovered from the brain 5 min after administration. Major differences appear to exist in the distribution of leptin between the male and female mice, indicating a high degree of sexual dimorphism. Although the half-lives were similar between male and female mice, almost twice the proportion of leptin was recovered from the digestive tract of male mice in comparison to that reported previously for females. This would seem to indicate a major difference in leptin distribution and possibly function between males and females. PMID:27998953

  6. Workplace homicides of Texas males.

    PubMed

    Davis, H

    1987-10-01

    A review of Texas death certificates for 1975-84 identified 779 civilian males whose deaths were homicides that occurred in the workplace. Injuries from firearms caused 81 per cent of the deaths. The overall rate of workplace homicide was 2.1/100,000 male workers/year. Males employed in taxicab service had the highest rate of workplace homicide. 78.2/100,000 male workers/year. Males employed in certain retail trade industries, law enforcement, and the private-security industry also had high rates of workplace homicide. Male workers greater than or equal to 65 years old were at especially high risk, with a workplace-homicide rate 3.5 times that of younger workers. A review of medical examiners' records in five urban counties indicated that 32 per cent of victims who had worked in eating-and-drinking places and 5 per cent of other workers had blood or cerebrospinal-fluid alcohol levels greater than or equal to 0.10 g/dl. These results provide a base for designing effective strategies to prevent workplace homicides.

  7. 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.

  8. Estimating age: college males versus convicted male child sex offenders.

    PubMed

    Marsh, Robert; Romero, Sergio; Patrick, Steven

    2013-01-01

    Two samples, male college students and convicted male child sex offenders, are compared on their abilities to accurately estimate the age group of a series of photographs of a sole female ranging in age from 11 to 29. Both samples tend to overestimate the age group of the subject photos, and no significant difference was found between college students and convicted child sex offenders in their ability to estimate the age of females. Both groups are compared demographically, and only limited differences were found. The implications are discussed in regard to theory and prevention of child sexual abuse.

  9. Treatment Options for Male Breast Cancer

    MedlinePlus

    ... Breast & Gynecologic Cancers Breast Cancer Screening Research Male Breast Cancer Treatment (PDQ®)–Patient Version General Information about Male Breast Cancer Go to Health Professional Version Key Points Male ...

  10. Treatment Option Overview (Male Breast Cancer)

    MedlinePlus

    ... Breast & Gynecologic Cancers Breast Cancer Screening Research Male Breast Cancer Treatment (PDQ®)–Patient Version General Information about Male Breast Cancer Go to Health Professional Version Key Points Male ...

  11. General Information about Male Breast Cancer

    MedlinePlus

    ... Breast & Gynecologic Cancers Breast Cancer Screening Research Male Breast Cancer Treatment (PDQ®)–Patient Version General Information about Male Breast Cancer Go to Health Professional Version Key Points Male ...

  12. XYY male and hematologic malignancy.

    PubMed

    Oguma, N; Shigeta, C; Kamada, N

    1996-09-01

    Two cases of XYY male with refractory anemia with excess of blasts are reported, and previous reported XYY males with hematologic malignancy are reviewed. Altogether 26 cases were collected for analysis: acute myeloid leukemia (10), acute lymphocytic leukemia (seven), acute leukemia (two), chronic myelocytic leukemia (three), myelodysplastic syndrome (three), and essential thrombocythemia (one). The age at the time of diagnosis ranged in age from 7.5 to 81 years. In three of six XYY/XY mosaicism cases, XYY clone was associated with malignancy. However, in two cases XYY clone was not involved. The evidence presented here suggests that the event of an XYY male with hematologic malignancy is incidental rather than a genetic etiology.

  13. Familial aspects of male homosexuality.

    PubMed

    Dawood, K; Pillard, R C; Horvath, C; Revelle, W; Bailey, J M

    2000-04-01

    Research has generally supported the existence of familial-genetic factors for male sexual orientation, but has not shed much light on the specific nature of those influences. Gay men with gay brothers provide the opportunity to examine several hypotheses. Sixty-six men, representing 37 gay male sibling pairs, completed questionnaires assessing behavior on various measures including childhood and adult gender nonconformity, timing of awareness of homosexual feelings, self-acceptance, and the quality of family relationships. Consistent with prior findings using twins, gay brothers were similar in their degree of childhood gender non-conformity, suggesting that this variable may distinguish etiologically (e.g., genetically) heterogeneous subtypes. The large majority of gay men with brothers knew about their own homosexual feelings before they learned about their brothers' homosexual feelings, suggesting that discovery of brothers' homosexuality is not an important cause of male homosexuality.

  14. Male anorgasmia treated with oxytocin.

    PubMed

    Ishak, Waguih William; Berman, Daniel S; Peters, Anne

    2008-04-01

    Introduction. This is a case report on male anorgasmia that was successfully treated with oxytocin. Oxytocin is increased during arousal and peaks during orgasm. More recently, a study on humans published in Nature has shown its value in social bonding, increasing trust, and enhancing the sense of well-being. Aim. To test the effectiveness of administering oxytocin in a case of treatment-resistant anorgasmia. Methods. The patient underwent a biopsychosocial evaluation by a psychiatrist trained in sexual medicine and sex therapy for male orgasmic disorder, acquired type. Medical conditions, effect of substances, and psychological issues were ruled out. The patient was properly consented to using oxytocin as an off-label trial. Oxytocin was administered using a nasal spray intracoitally because of its ultra-short half-life. Results. Oxytocin was effective in restoring ejaculation. Conclusions. A case of treatment-resistant male anorgasmia was successfully treated with intracoital administration of intranasal oxytocin.

  15. Age and male erectile responsiveness.

    PubMed

    Solnick, R L; Birren, J E

    1977-01-01

    The purpose of the research was to determine (1) the difference in the rate of penile circumference increase per unit time between a group of young and a group of old normal males when exposed to the same erotic movie and (2) the correlation coefficient between penile shaft temperature increase and penile circumference increase. Ten males aged 19-30 years and ten males aged 48-65 years served as subjects. Each subject placed a thermistor and strain gauge on his penis and both outputs were recorded simultaneously on a two-channel recorder. The younger group responded at an erection rate 5.8 times faster than that of the older group. The correlation coefficient, based on the percent approach to oral temperature (98.6 degrees F) and the percent increase in penile circumference, was 0.75.

  16. Hormonal contraception in the male.

    PubMed

    Anderson, R A

    2000-01-01

    The hormonal approach to male contraception is based on the suppression of gonadotrophin secretion with secondary suppression of spermatogenesis. This can be achieved by administration of testosterone or other androgen alone, but combined administration with a progestogen or GnRH analogue allows the dose of testosterone to be reduced to physiological replacement doses. This approach has been investigated for many years but without identification of a regimen which results in sufficient suppression of spermatogenesis to provide ensured contraception in all men, safely and conveniently. The reasons for this are discussed, and recent developments towards a regimen that fulfills all these criteria are described. Crucial to development of any new product is that it will be used: surveys of both men and women indicate firmly positive attitudes towards a 'male pill'. There are, therefore, grounds for cautious optimism that the next decade may see the introduction of the first novel male contraceptive for several hundred years.

  17. 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.

  18. [Genetic evaluation of male homosexuality].

    PubMed

    Gasztonyi, Z

    1998-02-01

    The family trees of 16 homosexual males are evaluated in the material of their Genetic Counselling Clinic. The familial cluster of three cases corresponded to the X-linked recessive inheritance. The results of family, twin and adoption studies are reviewed and the recent findings of molecular genetic and brain researches are summarised. Male homosexuality comprises of different subgroups, but one major entity is caused by X-linked recessive gene(s). This genetic background represent a predisposition which is triggered or suppressed by external factors.

  19. Male genital trauma in sports.

    PubMed

    Hunter, Stanley R; Lishnak, Timothy S; Powers, Andria M; Lisle, David K

    2013-04-01

    Male genital trauma is a rare but potentially serious sports injury. Although such an injury can occur by many different mechanisms, including falls, collisions, straddle injuries, kicks, and equipment malfunction, the clinical presentation is typically homogeneous, characterized by pain and swelling. Almost all sports-related male genital injury comes from blunt force trauma, with involvement of scrotal structures far more common than penile structures. Most injuries can be treated conservatively, but catastrophic testicular injury must first be ruled out. Despite being relatively uncommon compared with other sports injuries, more than half of all testicular injuries are sustained during sports.

  20. Fertility regulation in the male

    PubMed Central

    de Kretser, D. M.

    1978-01-01

    The current state of research into new methods of male contraception is reviewed, with special emphasis on the efforts of the WHO Special Programme of Research, Development and Research Training in Human Reproduction. The article concentrates mainly on the development of orally administered or injectable substances capable of either (a) interfering with the hormonal control of testicular function, (b) disrupting spermatogenesis by direct influence on testis function, or (c) interfering with the fertilizing ability of the sperm and their transport. It is concluded that, despite the numerous areas of research currently being pursued, the availability of a new male contraceptive remains several years away. PMID:308403

  1. Mammary Malignancy in The Male

    PubMed Central

    Alexander, Leslie L.; Benninghoff, David L.; Camiel, Mortimer R.; Medina, Antonio

    1978-01-01

    Mammary carcinoma in the male, a relatively uncommon disease, represents about 0.9 to 1.5 percent of all breast cancers. 1,2 The authors reviewed 16 cases of male breast cancer seen in a 30-year period at the State University of New York, Kings County Hospital Medical Center in Brooklyn, and the North Shore University Hospital in Manhasset. Epidemiology, etiology, demography, signs and symptoms, management, and prognosis are discussed. A review of pertinent literature is presented. ImagesFigure 1Figure 2 PMID:722829

  2. 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.

  3. Free radicals and male reproduction.

    PubMed

    Agarwal, Ashok; Allamaneni, Shyam S R

    2011-03-01

    Male factor accounts for almost 50% cases of infertility. The exact mechanism of sperm dysfunction is not known in many cases. Extensive research in the last decade has led to the identification of free radicals (reactive oxygen species) as mediators of sperm dysfunction in both specific diagnoses and idiopathic cases of male infertility. Elevated levels of reactive oxygen species are seen in up to 30-80% of men with male infertility. The role of free radicals has been studied extensively in the process of human reproduction. We know now that a certain level of free radicals is necessary for normal sperm function, whereas an excessive level of free radicals can cause detrimental effect on sperm function and subsequent fertilisation and offspring health. Oxidative stress develops when there is an imbalance between generation of free radicals and scavenging capacity of anti-oxidants in reproductive tract. Oxidative stress has been shown to affect both standard semen parameters and fertilising capacity. In addition, high levels of free radicals have been associated with lack of or poor fertility outcome after natural conception or assisted reproduction. Diagnostic techniques to quantify free radicals in infertile patients can assist physicians treating patients with infertility to plan for proper treatment strategies. In vivo anti-oxidants can be used against oxidative stress in male reproductive tract. Supplementation of in vitro anti-oxidants can help prevent the oxidative stress during sperm preparation techniques in assisted reproduction.

  4. Management of male urinary incontinence

    PubMed Central

    Moore, Katie C.; Lucas, Malcolm G.

    2010-01-01

    The majority of male urinary incontinence seen is secondary to sphincter weakness following prostatic surgery. As there is a rising elderly population and increasing numbers of surgical interventions for prostate cancer, incidence of male incontinence is increasing. Hence, management of male incontinence has become a subject of increased interest for urologists. Various non-surgical and surgical approaches have been suggested for this devastating condition. Non-invasive therapies are suggested for early postoperative and mild incontinence. For surgical treatment the artificial urinary sphincter is still labeled the gold standard despite the introduction of several more minimally invasive treatments. However, as yet there is no consensus on the optimal timing and best modality for managing these men. Well designed, centrally funded clinical trials are required to establish which treatment modality to offer and when in the broad spectrum of male incontinence. This review focuses mainly on the management of post-prostatectomy incontinence since the management of other types varies little from the modalities of treatment in women. PMID:20877603

  5. Neural Circuits: Male Mating Motifs.

    PubMed

    Benton, Richard

    2015-09-02

    Characterizing microcircuit motifs in intact nervous systems is essential to relate neural computations to behavior. In this issue of Neuron, Clowney et al. (2015) identify recurring, parallel feedforward excitatory and inhibitory pathways in male Drosophila's courtship circuitry, which might explain decisive mate choice.

  6. Ferocious fighting between male grasshoppers.

    PubMed

    Umbers, Kate D L; Tatarnic, Nikolai J; Holwell, Gregory I; Herberstein, Marie E

    2012-01-01

    Contests among individuals over mating opportunities are common across diverse taxa, yet physical conflict is relatively rare. Due to the potentially fatal consequences of physical fighting, most animals employ mechanisms of conflict resolution involving signalling and ritualistic assessment. Here we provide the first evidence of ubiquitous escalated fighting in grasshoppers. The chameleon grasshopper (Kosciuscola tristis) is an Australian alpine specialist, in which males engage in highly aggressive combat over ovipositing females. We describe discrete agonistic behaviours including mandible flaring, mounting, grappling, kicking and biting, and their use depending on the individual's role as challenger or defender. We show that male role predicts damage, with challengers being more heavily damaged than males defending females (defenders). Challengers also possess wider mandibles than defenders, but are similar in other metrics of body size. Our data suggest that fights escalate between males matched in body size and that mandibles are used as weapons in this species. This system represents an exciting opportunity for future research into the evolution of costly fighting behaviour in an otherwise placid group.

  7. Male Depression: Understanding the Issues

    MedlinePlus

    Diseases and Conditions Depression (major depressive disorder) Male depression is a serious medical condition, but many men try to ignore it or refuse treatment. Learn the signs and symptoms — and what to do. By Mayo Clinic Staff Do you feel irritable, isolated or withdrawn? Do you find yourself working all ...

  8. ASSESSMENT OF MALE REPRODUCTIVE TOXICITY

    EPA Science Inventory

    This chapter reviews the subject of risk assessment in male reproductive toxicology. After providing an overview of the risk assessment process, laboratory test protocols, including those specified by EPA and used by NIEHS are summarized and discussed in detail with respect to t...

  9. 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.

  10. Vicarious Emotional Responses of Macho College Males.

    ERIC Educational Resources Information Center

    Gold, Steven R.; And Others

    1992-01-01

    Explored whether vicarious emotional reactions of macho males reflect a lack of empathy and a tendency to respond with anger. Male subjects (n=107) viewed videotapes of a crying, quiescent, and smiling baby, respectively. Macho males reported more anger and less empathy for the crying baby than did less macho males. (RJM)

  11. Conspicuous Coloration in Males of the Damselfly Nehalennia irene (Zygoptera: Coenagrionidae): Do Males Signal Their Unprofitability to Other Males?

    PubMed Central

    Beatty, Christopher D.; Andrés, José A.; Sherratt, Thomas N.

    2015-01-01

    In damselflies, sexual colour dimorphism is commonly explained as a consequence of selection on traits that increase male attractiveness to females. However, while many species in the damselfly family Coenagrionidae (Insecta: Odonata) are sexually dimorphic, the males do not engage in displays, and male competition for mates resembles a “scramble”. An alternative explanation for the sexual differences in coloration within these species is that sexual dimorphism has evolved as a sex-related warning signal, with males signalling their uprofitability as mates to other males, thereby avoiding harassment from conspecifics. We evaluated an underlying assumption of the theory that male-male harassment rate is influenced by colour by comparing harassment of males of the species Nehalennia irene that had been painted to make them appear: (i) similar to an unaltered male (blue), (ii) different from a male (orange) and (iii) more similar to a female (black). When caged together we found that blue-painted males experienced significantly lower harassment than black-painted males. When unpainted males were caged with each type of painted male we found that blue-painted males and the unpainted males housed in the same cages experienced lower rates of harassment than males housed in cages where some males were painted black, suggesting that a single, reliable signal of unprofitability may benefit the individuals that carry it. While our results do not in themselves demonstrate that sexual colour dimorphism originally evolved as an intra-specific warning signal, they do show that harassment is influenced by coloration, and that such selection could conceivably maintain male coloration as a warning signal. PMID:26587979

  12. 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

  13. Male vs. female mediated teratogenesis

    SciTech Connect

    Manson, J.M.

    1982-04-01

    Different types of reproductive dysfunction with exposure of males and females during different stages of the reproductive process were correlated. It is a well-established principle that teratogenic exposure of the pregnant female, and thus of the embryo, during the organogenesis period of development can lead to birth defects in the offspring. The outcome of this exposure paradigm, as well as the outcomes associated with exposure during other stages of the reproductive process that have received less experimental attention are discussed. Insult to the germ cells of the male during spermatogenesis and to the female during oogenesis can also lead to reproductive dysfunction. The type of adverse outcome, however, is quite different from that occurring with embryonic exposure during the organogenesis period. An overview of this area will be given with the intent of focusing on those types of reproductive dysfunction that are most relevant to environmental exposure of men and women.

  14. Endocrinology of the Aging Male

    PubMed Central

    Wittert, Gary A.

    2011-01-01

    The endocrinology of the aging male is complex, with multiple hormones along the hypothalamic-pituitary-testicular (HPT) axis interacting with one another in feedback. As men age, there is a small and progressive (not precipitous, as in women) decline in several sex hormones, in particular testosterone and dehydroepiandrosterone, and related increases in luteinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin. The importance of these changes is wide-ranging because of the ubiquitous role of sex hormones in male physiology. This chapter discusses the endocrinology of the aging male. We provide an overview of the regulation of the HPT axis with an emphasis on the changes that occur with aging and the measurement of gonadal steroids, including hormone pulsatility, within-subject and circadian variations. The difficulties of assessing the symptoms of late-onset hypogonadism are highlighted. There is a comprehensive discussion of the epidemiology of sex hormone changes, including their age associations, prevalence of symptomatic hypogonadism, secular changes, risk factors, and the association of sex hormones with outcomes. PMID:21397200

  15. Meiotic abnormalities in infertile males.

    PubMed

    Egozcue, J; Sarrate, Z; Codina-Pascual, M; Egozcue, S; Oliver-Bonet, M; Blanco, J; Navarro, J; Benet, J; Vidal, F

    2005-01-01

    Meiotic anomalies, as reviewed here, are synaptic chromosome abnormalities, limited to germ cells that cannot be detected through the study of the karyotype. Although the importance of synaptic errors has been underestimated for many years, their presence is related to many cases of human male infertility. Synaptic anomalies can be studied by immunostaining of synaptonemal complexes (SCs), but in this case their frequency is probably underestimated due to the phenomenon of synaptic adjustment. They can also be studied in classic meiotic preparations, which, from a clinical point of view, is still the best approach, especially if multiplex fluorescence in situ hybridization is at hand to solve difficult cases. Sperm chromosome FISH studies also provide indirect evidence of their presence. Synaptic anomalies can affect the rate of recombination of all bivalents, produce achiasmate small univalents, partially achiasmate medium-sized or large bivalents, or affect all bivalents in the cell. The frequency is variable, interindividually and intraindividually. The baseline incidence of synaptic anomalies is 6-8%, which may be increased to 17.6% in males with a severe oligozoospermia, and to 27% in normozoospermic males with one or more previous IVF failures. The clinical consequences are the production of abnormal spermatozoa that will produce a higher number of chromosomally abnormal embryos. The indications for a meiotic study in testicular biopsy are provided.

  16. Male breast cancer: a review

    PubMed Central

    Fentiman, IS

    2009-01-01

    Male breast cancer (MBC) is rare, with the peak age of onset at 71 years. BRCA2 mutations are more frequent than BRCA1 with 20% of cases giving a family history. Risk factors for MBC are poorly understood and include working in high-ambient temperatures and exhaust fume exposure. MBC is associated with hyperoestrogenic states found in liver disease, Klinefelter’s syndrome, gonadal dysfunction or obesity. Most information on treatment of MBC is derived from large randomized trials carried out in female patients. The small numbers of MBC seen in any unit annually has precluded significant trials being carried out. Diagnosis and treatment of MBC is similar to that of female patients, but men tend to be treated with mastectomy rather than breast-conserving surgery. The mainstay of adjuvant therapy or palliative treatment for advanced disease is endocrine, mostly tamoxifen. Prognosis of male patients is equal to that of stage-matched women, but men tend to fare worse because of delay in presentation, leading to a large proportion of patients presenting with stage III or IV disease. Increased input is needed for psychological support for male breast cancer patients. Specific therapeutic questions about MBC need international trials to obtain meaningful answers. PMID:22276005

  17. Male-mediated developmental toxicity

    PubMed Central

    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. PMID:24369136

  18. 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

  19. Increased male-male courtship in ecdysone receptor deficient adult flies.

    PubMed

    Ganter, Geoffrey K; Walton, Kelsey L; Merriman, Jacob O; Salmon, Mark V; Brooks, Krista M; Maddula, Swathi; Kravitz, Edward A

    2007-05-01

    Male-male courtship is infrequent among mature adult Drosophila melanogaster. After pairs of mature adult males expressing a temperature-sensitive allele of the ecdysone receptor (EcR) gene were treated at a restrictive temperature, however, they engaged in elevated levels of male-male courtship. EcR-deficient males courted wildtype males and females, but were not courted by wildtype males. These results suggest that the ecdysone steroid hormone system may have a role in courtship initiation by adult male fruit flies.

  20. Homosexual behaviour increases male attractiveness to females

    PubMed Central

    Bierbach, David; Jung, Christian T.; Hornung, Simon; Streit, Bruno; Plath, Martin

    2013-01-01

    Male homosexual behaviour—although found in most extant clades across the Animal Kingdom—remains a conundrum, as same-sex mating should decrease male reproductive fitness. In most species, however, males that engage in same-sex sexual behaviour also mate with females, and in theory, same-sex mating could even increase male reproductive fitness if males improve their chances of future heterosexual mating. Females regularly use social information to choose a mate; e.g. male attractiveness increases after a male has interacted sexually with a female (mate choice copying). Here, we demonstrate that males of the tropical freshwater fish Poecilia mexicana increase their attractiveness to females not only by opposite-sex, but likewise, through same-sex interactions. Hence, direct benefits for males of exhibiting homosexual behaviour may help explain its occurrence and persistence in species in which females rely on mate choice copying as one component of mate quality assessment. PMID:23234866

  1. Male-male and male-female aggression may influence mating associations in wild octopuses (Abdopus aculeatus).

    PubMed

    Huffard, Christine L; Caldwell, Roy L; Boneka, Farnis

    2010-02-01

    Abdopus aculeatus engages in frequent aggression and copulation, exhibits male mate-choice, and employs multiple mating tactics. Here we draw upon established hypotheses to compare male-male aggression (MMA) and male-female aggression (MFA), as they relate to their mating behavior in the wild. When contesting for females, males appear to balance mate preference (resource value) with perceived chances of winning contests (resource holding potential). Although males spent more time mating with and contesting for large "Adjacent Guarded" females (those occupying a den within arm's reach of a large "Adjacent Guarding" male), they exhibited higher rates of aggression over nonadjacent "Temporarily Guarded" females that may be more accessible. The major determinant of male-male aggressive success was size, and this factor may dictate the expression of conditional mating tactics in males. "Adjacent Guarding" males were the largest and most aggressively successful males, earning the most time copulating with females. They are considered to have the highest resource holding potential (RHP) in MMA. By contrast, in MFA, some larger individuals fled from smaller individuals, indicating that RHP appears to be a function of both size and sex in intersexual aggression. This result suggests variation in aggressiveness, or potential for severe injury-even sexual cannibalism during MFA. Male-female aggression may also be influenced by the sexual nonreceptivity of some individuals, or attempts by both sexes to increase foraging behavior by delaying mate-guarding activity.

  2. Male-mediated developmental toxicity

    SciTech Connect

    Anderson, Diana . E-mail: d.anderson1@bradford.ac.uk

    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 of 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 from

  3. 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

  4. The epidemiology of male infertility.

    PubMed

    Winters, Brian R; Walsh, Thomas J

    2014-02-01

    The purpose of this review is to integrate understanding of epidemiology and infertility. A primer on epidemiologic science and an example disease for which the design of epidemiologic investigations is readily apparent are provided. Key features of infertility that limit epidemiologic investigation are described and a survey of available data on the epidemiology of infertility provided. Finally, the work that must be completed to move this area of research forward is proposed, and, with this new perspective of "infertility as a disease," improvements envisioned in public health that may be gained through improved understanding of the epidemiology of male infertility.

  5. Aging changes in the male reproductive system

    MedlinePlus

    ... ency/article/004017.htm Aging changes in the male reproductive system To use the sharing features on this page, please enable JavaScript. Aging changes in the male reproductive system may include changes in testicular tissue, sperm production, ...

  6. 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.

  7. 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

  8. Male contraception: expanding reproductive choice.

    PubMed

    Rajalakshmi, M

    2005-11-01

    The development of steroid-based oral contraceptives had revolutionized the availability of contraceptive choice for women. In order to expand the contraceptive options for couples by developing an acceptable, safe and effective male contraceptive, scientists have been experimenting with various steroidal/non-steroidal regimens to suppress testicular sperm production. The non-availability of a long-acting androgen was a limiting factor in the development of a male contraceptive regimen since all currently tested anti-spermatogenic agents also concurrently decrease circulating testosterone levels. A combination regimen of long-acting progestogen and androgen would have advantage over an androgen-alone modality since the dose of androgen required would be much smaller in the combination regimen, thereby decreasing the adverse effects of high steroid load. The progestogen in the combination regimen would act as the primary anti-spermatogenic agent. Currently, a number of combination regimens using progestogen or GnRH analogues combined with androgen are undergoing trials. The side effects of long-term use of androgens and progestogens have also undergone evaluation in primate models and the results of these studies need to be kept in view, while considering steroidal regimens for contraceptive use in men. Efforts are also being made to popularize non-scalpel vasectomy and to develop condoms of greater acceptability. The development of contraceptive vaccines for men, using sperm surface epitopes not expressed in female reproductive tract as source, still requires considerable research efforts.

  9. [Overweight and secretory male infertility].

    PubMed

    Oshakbaev, K P; Abylaĭuly, Zh; Dukenbaeva, B A

    2009-01-01

    We have performed a trial with participation of 60 males aged 23-52. Of them, 30 had secretory male iufertility (SMI) and obesity. The control 30 patients were healthy volunteers. The protocol was performed by two stages. Stage 1 included: investigation of a clinico-laboratory status, of correlation between a sorption function of erythrocytes, endogenic metabolic intoxication (EMI) and spermogram parameters, concentration of serum testosterone in SMI patients. Stage 2 consisted in treatment of the intoxication by reducing body mass. All the infertile men were obese; 30% of them had low glucose tolerance, 46.7% had stage 2 hypertension, 23.3%--seasonal allergic symptoms. The level of organic substances on the surface of erythrocytes in infertile men was higher than in the controls (p < 0.01). A negative correlation was seen between spermogram parameters and organic substances content on erythrocytic surface (p < 0/05), concentration of serum testosterone and the above substances (p < 0.01). The loss of fat tissue by 7-14 kg by infertile men resulted in a positive trend in spermogram parameters and the level of serum testosterone (p < 0.01).

  10. Male facial anthropometry and attractiveness.

    PubMed

    Soler, Caries; Kekäläinen, Jukka; Núñez, Manuel; Sancho, María; Núñez, Javier; Yaber, Iván; Gutiérrez, Ricardo

    2012-01-01

    The symmetry and masculinity of the face are often considered important elements of male facial attractiveness. However, facial preferences are rarely studied on natural faces. We studied the effect of these traits and facial metric parameters on facial attractiveness in Spanish and Colombian raters. In total, 13 metric and 11 asymmetry parameters from natural, unmanipulated frontal face photographs of 50 Spanish men were measured with the USIA semiautomatic anthropometric software. All raters (women and men) were asked to rank these images as potential long-term partners for females. In both sexes, facial attractiveness was negatively associated with facial masculinity, and preference was not associated with facial symmetry. In Spanish raters, both sexes preferred male traits that were larger in the right side of the face, which may reflect a human tendency to prefer a certain degree of facial asymmetry. We did not find such preference in Colombian raters, but they did show stronger preference for facial femininity than Spanish raters. Present results suggest that facial relative femininity, which is expected to signal, eg good parenting and cooperation skills, may be an important signal of mate quality when females seek long-term partners. Facial symmetry appears unimportant in such long-term mating preferences.

  11. Pink or blue ... black and blue? Examining pregnancy as a predictor of intimate partner violence and femicide.

    PubMed

    Taylor, Rae; Nabors, Erin L

    2009-11-01

    This study explores the effect of pregnancy on women's risk of IPV victimization. Previous studies have produced conflicting findings and have been limited by comparing only two categories of IPV. The current study included analyses of the effect of pregnancy on three statuses of IPV: no abuse, nonlethal abuse, and lethal abuse. The data used for this project are taken from the first phase of the Chicago Women's Health Risk Study (CWHRS). Findings suggest that both nonlethal and lethal abuse statuses differ significantly from no abuse in that women's risk of IPV victimization may decrease during pregnancy.

  12. Value Profiles of Male and Female Entrepreneurs.

    ERIC Educational Resources Information Center

    Fernald, Lloyd W., Jr.; Solomon, George T.

    1987-01-01

    Comparison of the values of 86 male and 74 female entrepreneurs found males' highest terminal values being pleasure and true friendship while females' highest terminal values were health and self-respect. High instrumental values for males were ambition and broadmindedness; while for females high instrumental values were honesty and…

  13. Synchronous bilateral breast cancer in a male

    PubMed Central

    Rubio Hernández, María Caridad; Díaz Prado, Yenia Ivet; Pérez, Suanly Rodríguez; Díaz, Ronald Rodríguez; Aleaga, Zaili Gutiérrez

    2013-01-01

    Male breast cancer, which represents only 1% of all breast cancers, is occasionally associated with a family history of breast cancer. Sporadic male breast cancers presenting with another primary breast cancer are extremely rare. In this article, we report on a 70-year-old male patient with bilateral multifocal and synchronous breast cancer and without a family history of breast cancer. PMID:24319497

  14. 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…

  15. Flunitrazepam intake in male offenders.

    PubMed

    Dåderman, Anna M; Edman, Gunnar; Meurling, Ann Wirsén; Levander, Sten; Kristiansson, Marianne

    2012-04-01

    The abuse of flunitrazepam (FZ) compounds is worldwide, and several studies have reflected on the consequences with regard to violence, aggression and criminal lifestyle of FZ users. Criminals take high doses of FZ or some other benzodiazepines to "calm down" before the planned crime. There is support from earlier studies that most likely, all benzodiazepines may increase aggression in vulnerable males. Chronic intake of high doses of FZ increases aggression in male rats. Because psychopathy involves aggression, we have examined whether psychopathy as well as any of the four facets of the Psychopathy Checklist-Revised (PCL-R) (Interpersonal, Affective, Lifestyle and Antisocial) are related to different substance use disorders, with the focus on FZ. We have also examined the relationship between each PCL-R item and FZ use. Participants were 114 male offenders aged 14-35 years, all of whom were convicted for severe, predominantly violent, offences. Substance use, including FZ, was not more common in those who scored high in psychopathy. Use of FZ was more common in offenders who scored high in Facet 4 (Antisocial) of the PCL-R (odds ratio = 4.30, 95% CI 1.86-9.94). Only one of the PCL-R items, "Criminal versatility", was significantly associated with FZ use (odds ratio = 3.7). It may be concluded that intake of FZ has a specific relationship to only one of the facets and not to psychopathy per se. The findings have also important theoretical implications because Facet 4 is not a key factor of the construct of psychopathy. Clinical implications of the article: We have used the new two-factor and four-facet theoretical model of psychopathy in the young offender population, many of them with one or more substance use disorders. The present results suggest that antisocial behavior defined by Facet 4 (poor behavioral control, early behavior problems, juvenile delinquency, revocation of conditional release and criminal versatility) in the studied subjects is more typical

  16. Misexpression of the white (w) gene triggers male-male courtship in Drosophila.

    PubMed Central

    Zhang, S D; Odenwald, W F

    1995-01-01

    We report here that the general ectopic expression of a tryptophan/guanine transmembrane transporter gene, white (w), induces male-male courtship in Drosophila. Activation of a hsp-70/miniwhite (mini-w) transgene in mature males results in a marked change in their sexual behavior such that they begin to vigorously court other mature males. In transformant populations containing equal numbers of both sexes, most males participate, thus forming male-male courtship chains, circles, and lariats. Mutations that ablate the w transgene function also abolish this inducible behavior. Female sexual behavior does not appear to be altered by ectopic w expression. By contrast, when exposed to an active homosexual courtship environment, non-transformant males alter their behavior and actively participate in the male-male chaining. These findings demonstrate that, in Drosophila, both genetic and environmental factors play a role in male sexual behavior. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7777542

  17. Treatment of hypogonadism in males.

    PubMed

    Watson, Sara; Fuqua, John S; Lee, Peter A

    2014-02-01

    The treatment of adolescent males with hypogonadism using testosterone is dependent on the underlying diagnosis as well as the patient's and family's preferences. Those with testicular failure, always a pathologic condition, begin lifelong therapy, while short-term therapy is often begun for those who have a delayed puberty. There is a wide variety of testosterone formulations available, with differences in adverse events sometimes associated with the method of administration. The goals of treatment involve stimulating physical puberty, including achievement of virilization, a normal muscle mass and bone mineral density for age, and improvement in psychosocial wellbeing. While androgen therapy results in physical changes of puberty, the potential for fertility must be considered for those with permanent gonadotropin deficiency. in this population, therapy with gonadotropins or gonadotropin releasing hormone may be effective. For those with testicular failure, fertility may be possible but requires assisted reproductive procedures.

  18. 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

  19. Vocal competition in male Xenopus laevis frogs

    PubMed Central

    Tobias, Martha L.; Corke, Anna; Korsh, Jeremy; Yin, David; Kelley, Darcy B.

    2011-01-01

    Male Xenopus laevis frogs produce underwater advertisement calls that attract gravid females and suppress calling by male competitors. Here we explore whether groups of males establish vocal ranks and whether auditory cues alone suffice for vocal suppression. Tests of male–male pairs within assigned groups reveal linear vocal dominance relations, in which each male has a defined rank. Both the duration over which males interact, as well as the number of competitive opportunities, affect linearity. Linear dominance across the group is stable for about 2 weeks; rank is dynamic. Males engage in physical interactions (clasping) while paired but clasping and vocal rank are not correlated. Playbacks of advertisement calls suppress calling and calls from high- and low-ranking males are equally effective. Thus, auditory cues alone suffice to suppress vocal behavior. Playback intensities equivalent to a nearby male advertising effectively suppress calling while low-intensity playbacks are either ineffective or stimulate vocal behavior. X. laevis advertisement calls are biphasic, composed of alternating fast and slow click trills. Approximately half the males tested are more vocally suppressed by all slow than by all fast trills; thus, these males can distinguish between the two phases. The fully aquatic family Pipidae diverged from terrestrial ancestors approximately 170 mya. Vocal suppression in the X. laevis mating system may represent the translation of an ancient anuran social strategy to underwater life. PMID:21442049

  20. Functional rare males in diploid parthenogenetic Artemia.

    PubMed

    Maccari, M; Gómez, A; Hontoria, F; Amat, F

    2013-09-01

    Functional males that are produced occasionally in some asexual taxa - called 'rare males' - raise considerable evolutionary interest, as they might be involved in the origin of new parthenogenetic lineages. Diploid parthenogenetic Artemia produce rare males, which may retain the ability to mate with females of related sexual lineages. Here, we (i) describe the frequency of male progeny in populations of diploid parthenogenetic Artemia, (ii) characterize rare males morphologically, (iii) assess their reproductive role, using cross-mating experiments with sexual females of related species from Central Asia and characterize the F1 hybrid offspring viability and (iv) confirm genetically both the identity and functionality of rare males using DNA barcoding and microsatellite loci. Our result suggests that these males may have an evolutionary role through genetic exchange with related sexual species and that diploid parthenogenetic Artemia is a good model system to investigate the evolutionary transitions between sexual species and parthenogenetic strains.

  1. 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.

  2. [Brain mechanisms of male sexual function].

    PubMed

    Wang, Ying; Dou, Xin; Li, Jun-Fa; Luo, Yan-Lin

    2011-08-01

    In this paper, we reviewed the brain imaging studies of male sexual function in recent years from three aspects: the brain mechanism of normal sexual function, the brain mechanism of sexual dysfunction, and the mechanism of drug therapy for sexual dysfunction. Studies show that the development stages of male sexual activities, such as the excitement phase, plateau phase and orgasm phase, are controlled by different neural networks. The mesodiencephalic transition zone may play an important role in the start up of male ejaculation. There are significant differences between sexual dysfunction males and normal males in activation patterns of the brain in sexual arousal. The medial orbitofrontal cortex and inferior frontal gyrus in the abnormal activation pattern are correlated with sexual dysfunction males in sexual arousal. Serum testosterone and morphine are commonly used drugs for male sexual dysfunction, whose mechanisms are to alter the activating levels of the medial orbitofrontal cortex, insula, claustrum and inferior temporal gyrus.

  3. The craniofacial complex in 47,XYY males.

    PubMed

    Grön, M; Pietilä, K; Alvesalo, L

    1997-08-01

    Eight adult, Finnish 47,XYY males were compared with population male and female controls and, in addition, three of them were compared with first-degree male relatives. Linear and angular measurements were made from standardized lateral cephalograms of patients and normal population controls from the "Kvantti" study series. In both comparisons the craniofacial dimensions in 47,XYY males were larger than those in population male and female controls. Their craniofacial proportions and plane angles were similar to those of normal men except for a larger lower facial height with posterior rotation of the mandible and a tendency to bimaxillary protrusion, a longer cranial base and a lesser cranial-base angle. Thus the supernumerary Y chromosomal gene(s) in 47,XYY males may result in larger craniofacial dimensions than in normal males, without substantial effects on dimensional ratios and plane angles. This general metric pattern is similar to that observed in relation to many adult body and head dimensions, and the dental arches and tooth crowns, of 47,XYY males. The foramen magnum in 47,XYY males was smaller in the sagittal plane than that of normal males and females.

  4. Cytokinesis in plant male meiosis.

    PubMed

    De Storme, Nico; Geelen, Danny

    2013-03-01

    In somatic cell division, cytokinesis is the final step of the cell cycle and physically divides the mother cytoplasm into two daughter cells. In the meiotic cell division, however, pollen mother cells (PMCs) undergo two successive nuclear divisions without an intervening S-phase and consequently generate four haploid daughter nuclei out of one parental cell. In line with this, the physical separation of meiotic nuclei does not follow the conventional cytokinesis pathway, but instead is mediated by alternative processes, including polar-based phragmoplast outgrowth and RMA-mediated cell wall positioning. In this review, we outline the different cytological mechanisms of cell plate formation operating in different types of PMCs and additionally focus on some important features associated with male meiotic cytokinesis, including cytoskeletal dynamics and callose deposition. We also provide an up-to-date overview of the main molecular actors involved in PMC wall formation and additionally highlight some recent advances on the effect of cold stress on meiotic cytokinesis in plants.

  5. [Male breast cancer: a challenge for urologists].

    PubMed

    Hofer, C; Schmalfeldt, B; Gschwend, J E; Herkommer, K

    2010-09-01

    Male breast cancer (male BC) accounts for <1% of all cancers in men, showing an increasing incidence with a peak in the sixth decade. Overall, men experience a worse prognosis than women, probably due to an advanced stage together with the higher age at diagnosis of male patients. Major risk factors for developing male BC include clinical disorders involving hormonal imbalances (excess of estrogen or a deficiency of testosterone as seen in patients with Klinefelter syndrome) and a positive family history for breast cancer. About 90% of male BC are invasive ductal carcinomas. Standard treatment for localized cancer is surgical removal. Adjuvant radiation and systemic therapy are the same as in women with breast cancer. Male BC expresses hormone receptors in about 90% of cases; therefore, tamoxifen is a therapeutic option. A future challenge for the urologist or andrologist is to diagnose the disease at an early stage to improve prognosis.

  6. 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

  7. The Epidemiology of Male Breast Cancer.

    PubMed

    Ferzoco, Raina M; Ruddy, Kathryn J

    2016-01-01

    Male breast cancer is a rare disease, accounting for only 1% of breast cancer diagnoses in the USA. The current literature suggests that genetic factors including BRCA2 mutations, family history, age, androgen/estrogen imbalance, and environmental exposures may predispose to male breast cancer. In this manuscript, we will review known and possible risk factors for male breast cancer, as well as describe the clinical patterns of the disease.

  8. 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.

  9. Introduction: Ejaculatory problems and male infertility.

    PubMed

    Sigman, Mark

    2015-11-01

    There are a variety of dysfunctions of the ejaculatory process which may negatively impact male fertility but are not commonly discussed. The meanings of the terms used to describe these conditions are often unclear. This month's Views and Reviews define the commonly used and confused terms. The initial article explains normal male function with an emphasis on the ejaculatory process. Following articles discuss the causes, evaluation and management of the male with ejaculatory dysfunction.

  10. Strategic male mating effort and cryptic male choice in a scorpionfly.

    PubMed

    Engqvist, L; Sauer, K P

    2001-04-07

    In animal species with high male mating effort, males often find themselves in a dilemma: by increasing their mating effort, the gain from each copulation increases but simultaneously reduces available resources and, thus, the opportunity for future copulations. Therefore, we expect males to spend less reproductive resources on matings that provide low reproductive potential, thereby saving resources for future copulations, possibly with high-quality females, a sort of cryptic male choice. However, the strength of the trade-off between investment in a current mating and resources available for future matings must not be the same for all males. Males with relatively high mating costs should allocate their limited resources more cautiously than males with more plentiful resources. Here, we examine this prediction in the scorpionfly Panorpa cognata. Prior to copulation, males produce a large salivary mass on which females feed during copulation. We show that the production of larger salivary masses leads to longer copulations. Moreover, the size of the salivary gland and salivary mass increases with increasing male condition. However, males in poor condition make a relatively higher mating investment than males in good condition. We therefore expect male condition to influence cryptic male choice. In accordance with our hypothesis, only males in poor condition choose cryptically, producing larger salivary masses in copulations with females of high fecundity.

  11. Sexually coercive male chimpanzees sire more offspring.

    PubMed

    Feldblum, Joseph T; Wroblewski, Emily E; Rudicell, Rebecca S; Hahn, Beatrice H; Paiva, Thais; Cetinkaya-Rundel, Mine; Pusey, Anne E; Gilby, Ian C

    2014-12-01

    In sexually reproducing animals, male and female reproductive strategies often conflict. In some species, males use aggression to overcome female choice, but debate persists over the extent to which this strategy is successful. Previous studies of male aggression toward females among wild chimpanzees have yielded contradictory results about the relationship between aggression and mating behavior. Critically, however, copulation frequency in primates is not always predictive of reproductive success. We analyzed a 17-year sample of behavioral and genetic data from the Kasekela chimpanzee (Pan troglodytes schweinfurthii) community in Gombe National Park, Tanzania, to test the hypothesis that male aggression toward females increases male reproductive success. We examined the effect of male aggression toward females during ovarian cycling, including periods when the females were sexually receptive (swollen) and periods when they were not. We found that, after controlling for confounding factors, male aggression during a female's swollen periods was positively correlated with copulation frequency. However, aggression toward swollen females was not predictive of paternity. Instead, aggression by high-ranking males toward females during their nonswollen periods was positively associated with likelihood of paternity. This indicates that long-term patterns of intimidation allow high-ranking males to increase their reproductive success, supporting the sexual coercion hypothesis. To our knowledge, this is the first study to present genetic evidence of sexual coercion as an adaptive strategy in a social mammal.

  12. Brood care by male bumble bees

    PubMed Central

    Cameron, Sydney A.

    1985-01-01

    Male Bombus griseocollis (Hymenoptera: Apidae) share in the brood care of nestmates by incubating pupae (usually during the first few days after they emerge as adults). Male posture during incubation of a pupa is identical to that observed for females. Pupae incubated by males were 4°C-6°C above the temperature of unincubated pupae. Although this increase was not as great as that caused by workers or queens, it was an important factor in warming pupae. Incubating males may benefit nestmates incidentally without lowering their own individual fitness. Images PMID:16593608

  13. Modulation of Drosophila male behavioral choice

    PubMed Central

    Certel, Sarah J.; Savella, Mary Grace; Schlegel, Dana C. F.; Kravitz, Edward A.

    2007-01-01

    The reproductive and defensive behaviors that are initiated in response to specific sensory cues can provide insight into how choices are made between different social behaviors. We manipulated both the activity and sex of a subset of neurons and found significant changes in male social behavior. Results from aggression assays indicate that the neuromodulator octopamine (OCT) is necessary for Drosophila males to coordinate sensory cue information presented by a second male and respond with the appropriate behavior: aggression rather than courtship. In competitive male courtship assays, males with no OCT or with low OCT levels do not adapt to changing sensory cues and court both males and females. We identified a small subset of neurons in the suboesophageal ganglion region of the adult male brain that coexpress OCT and male forms of the neural sex determination factor, Fruitless (FruM). A single FruM-positive OCT neuron sends extensive bilateral arborizations to the suboesophageal ganglion, the lateral accessory lobe, and possibly the posterior antennal lobe, suggesting a mechanism for integrating multiple sensory modalities. Furthermore, eliminating the expression of FruM by transformer expression in OCT/tyramine neurons changes the aggression versus courtship response behavior. These results provide insight into how complex social behaviors are coordinated in the nervous system and suggest a role for neuromodulators in the functioning of male-specific circuitry relating to behavioral choice. PMID:17360588

  14. Codependency in male and female helping professionals.

    PubMed

    Martsolf, D S; Hughes-Hammer, C; Estok, P; Zeller, R A

    1999-04-01

    The purpose of this study is to determine and compare the prevalence of codependency in a group of 77 female and a group of 72 male helping professionals. Relatively low rates of codependency were observed in this sample, and the five-factor structure of the Codependency Assessment Tool (CODAT) was replicated. Males showed slightly higher codependency than females on the total CODAT and on the Hiding Self and Family of Origin Issues subscales. The CODAT was shown to be relevant to both males and females. Further research is needed to determine if a general population of male and female subjects would yield similar results.

  15. 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

  16. Testosterone and reproductive effort in male primates.

    PubMed

    Muller, Martin N

    2016-09-08

    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.

  17. The transvestite serpent: why do male garter snakes court (some) other males?

    PubMed

    Shine; Harlow; LeMaster; Moore; Mason

    2000-02-01

    In large mating aggregations of red-sided garter snakes, Thamnophis sirtalis parietalis, in Manitoba, male courtship is directed not only to females, but also to other males with female-like skin lipids ('she-males'). We show that 'she-maleness' is an intrinsic property of a male rather than an artefact of lipid transfer from females, and that male-male courtship is very common in the field. She-males were distinctive in terms of appearance (they were heavier than other males and more often covered with mud), behaviour (they were inactive and rarely courted females) and performance (they were slow crawlers, ineffective courters and easily outcompeted by other males in mating trials). 'She-maleness' was not a characteristic of a particular subset of males, as envisaged in previous work; instead, it was a transitory phase that most (perhaps all) male snakes passed through soon after they first emerged from the winter den. Recently emerged males spent their first day or two relatively inactive, while restoring physiological functions (including locomotor performance and courtship ability). Experimental application of female skin lipids on to males dramatically decreased courtship levels of the recipient snakes. Thus, recently emerged males may derive two kinds of benefit from mimicking female skin lipids. First, female mimicry 'switches off' the male's own (energetically expensive) courtship at a time when that courtship would be unproductive. Second, it may disadvantage his rivals by distracting them from females, and increasing their energy expenditure. Copyright 2000 The Association for the Study of Animal Behaviour.

  18. Male-male competition leads to less abundant but more attractive sperm.

    PubMed

    Zizzari, Z Valentina; van Straalen, Nico M; Ellers, Jacintha

    2013-01-01

    Males employ complex strategies to optimize their reproductive success when faced with male-male competition; for instance, they can adjust the ejaculate characteristics. In copulating species, a male may also strategically adjust his ejaculate expenditure according to female quality. Quantifying the relative contribution of ejaculate plasticity in male reproductive success is often difficult, especially when females exert postcopulatory cryptic choice. One way to quantify the functional significance of ejaculate plasticity is offered by mating systems in which the reproductive partners do not meet each other during insemination. In the collembolan Orchesella cincta, males deposit their ejaculates (spermatophores) irrespective of the presence of females. We tested whether Orchesella males adjust spermatophore number when exposed to the presence of another male and whether changes in spermatophore production influence female choice. We found that Orchesella males display plasticity in spermatophore allocation. Males decreased the spermatophore number when exposed to a rival male. Moreover, females preferentially took up spermatophores of males that were exposed to a competitor. The reduction in spermatophore number suggests, besides an adaptive response to the risk of ejaculate removal by rival males, an optimization strategy owing to the costs of more attractive spermatophores.

  19. Recruiting and Retaining Male Special Education Teachers

    ERIC Educational Resources Information Center

    Rice, Craig J.; Goessling, Deborah Peters

    2005-01-01

    The percentage of male students who complete an undergraduate degree in the field of special education continues to be much lower than that of female graduates. Low status, low salaries, the perception of teaching as women's work, potential complaints of child abuse and sexual harassment, and a lack of male peer groups factor into this low…

  20. Male-Female Sexuality: An Annotated Bibliography.

    ERIC Educational Resources Information Center

    Wilson, Janice

    This annotated bibliography contains over 500 sources on the historical and contemporary development and expression of male and female sexuality. There are 68 topic headings which provide easy access for subject areas. A major portion of the bibliography is devoted to contemporary male-female sexuality. These materials consist of research findings…

  1. 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…

  2. [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.

  3. 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…

  4. 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…

  5. Female choice for male motor skills

    PubMed Central

    Barske, Julia; Schlinger, Barney A.; Wikelski, Martin; Fusani, Leonida

    2011-01-01

    Sexual selection was proposed by Darwin to explain the evolution of male sexual traits such as ornaments and elaborate courtship displays. Empirical and theoretical studies have traditionally focused on ornaments; the reasons for the evolution of elaborate, acrobatic courtship displays remain unclear. We addressed the hypothesis that females choose males on the basis of subtle differences in display performance, indicating motor skills that facilitate survival. Male golden-collared manakins (Manacus vitellinus) perform elaborate, acrobatic courtship displays. We used high-speed cameras to record the displays of wild males and analysed them in relation to male reproductive success. Females preferred males that performed specific display moves at greater speed, with differences of tens of milliseconds strongly impacting female preference. In additional males, we recorded telemetrically the heart rate during courtship using miniature transmitters and found that courtship is associated with profoundly elevated heart rates, revealing a large metabolic investment. Our study provides evidence that females choose their mates on the basis of subtle differences in motor performance during courtship. We propose that elaborate, acrobatic courtship dances evolve because they reflect motor skills and cardiovascular function of males. PMID:21508030

  6. Career Development of Black Males: Case Studies.

    ERIC Educational Resources Information Center

    Chung, Y. Barry; Baskin, Monica L.; Case, Andrew B.

    1999-01-01

    Case studies of six black males explored background, school and work experiences, and career issues. These themes emerged: fathers' financial support and role modeling influenced career development; other male role models affected aspirations; social, especially parental support for education and careers influenced decision making; and racism…

  7. Changing Views on Male Early Childhood Teachers.

    ERIC Educational Resources Information Center

    Robinson, Bryan E.

    1981-01-01

    Traces the changing views on the role and status of male early childhood education teachers in the forties and fifties (male prohibition), the sixties and early seventies (the macho image), and the late seventies and early eighties (the age of androgyny).

  8. Male Categories: Are All Men "Masculine?"

    ERIC Educational Resources Information Center

    England, Eileen M.; Hyland, Diane T.

    Research on gender stereotypes has contrasted males with females, describing males by competency traits and females by traits which denote warmth or emotionality. However, it has become clear that these traits do not satisfactorily describe all members of either sex, since not all men possess only masculine characteristics and not all women…

  9. Young Adult Literature for Young Adult Males.

    ERIC Educational Resources Information Center

    Gill, Sam D.

    1999-01-01

    Argues that young adult literature can play a significant role in the emotional and mental health of an adolescent as well as help young males become more literate. Offers a 19-item annotated list of young adult novels with male protagonists, sorted by themes: nature and adventure stories, sports stories, genre stories, historical stories, and…

  10. Male skin care: shaving and moisturization needs.

    PubMed

    Oblong, John E

    2012-01-01

    Historically, most cosmetic and medical cosmetic research has been focused on the female consumer. Advancements in the development of grooming instruments as well as changing consumer habits and attitudes toward male cosmetic skin care needs support the need to develop a deeper understanding of male skin biology and how that can be used to improve the quality of life relative to societal interactions. Male skin biology has been found to have unique properties that are distinct from females and have a significant impact on the way males groom and maintain their overall appearance. Research to date has found that male skin has a different response profile to such environmental insults as UV, heat, and stress that is based not on just differences in cosmetic or dermatological product usage but also on underlying biological differences. These differences are discussed with the implications to a broader understanding of male facial skin care needs that spans from daily grooming practices to overall health status that impacts higher incidence rate of skin cancer among males. This highlights that male skin care has a holistic need to ensure proper grooming and sunscreen moisturizer usage.

  11. 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…

  12. 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…

  13. Male Roles in Mid-Life.

    ERIC Educational Resources Information Center

    Cohen, Jessica Field

    1979-01-01

    A review of research literature in the area of male roles and middle age suggests that adherence to the traditional male role may be deleterious to readjustment during middle-age transitions. Traditional roles require men to have characteristics that are questioned during the middle years. (Author)

  14. Characteristics Related to Female & Male Leaders

    ERIC Educational Resources Information Center

    Richardson, Agnes M.

    2004-01-01

    The following research investigated gender and the leadership role and determined if there are differences in leadership styles, behaviors, traits, and characteristics between female leaders and male leaders. Literature suggests there are specific gender leadership differences between males and females in leadership styles, behaviors, traits, and…

  15. Approaches to male hypogonadism in primary care

    PubMed Central

    Lawrence, Kristi L.; Stewart, Felicia; Larson, Brandi M.

    2017-01-01

    Abstract: Evidence suggests that providers are not adhering to current testosterone replacement therapy guidelines when treating male hypogonadism. Understanding the diagnosis and management of this condition is further complicated by conflicting recommendations among available guidelines. NPs must select and follow the best guideline recommendations available to optimally treat male hypogonadism. PMID:28085783

  16. Family planning--male responsibility campaign.

    PubMed

    1982-01-01

    At a press conference on March 29, 1982, the Family Planning Association of Hong Kong launched a 1-year campaign to encourage men to assume more responsibility in family planning. The campaign will publicize the message that "real men" share family planning responsibilities with their wives. The campaign was developed in response to the Association's recognition that its male clinics were underutilized. Although the Association established its 1st male clinic in 1960, only 1.3% of the Association's clients in 1981 were men. Futhermore, the number of vasectomies performed in recent years had not increased. The campaign will seek to overcome the prevailing attitude that family planning is a women's issue, the reluctance of men to discuss fertility with their physicians, and various misconceptions about male methods. Activities initiated during the 1st few months of the campaign included 1) broadcasting a 30-second television spot to promote the male responsibility message; 2) setting up a mobile exhibit in railway stations and commercial complexes to inform the public about male birth control methods and about the services offered at the Association's male clinics; 3) giving away items which publicize the male clinics such as stickers, match boxes, condom samples, and literature; and 4) selling T-shirts which promote 2 as the ideal family size. In addition, a contest aimed at publicizing male birth control was undertaken jointly by a television magazine, Durex Products, and the Association. The contest engendered considerable interest and 2600 entries were received from men.

  17. Characteristics of Male Homosexual College Students

    ERIC Educational Resources Information Center

    Fromhart, Michael V.

    1971-01-01

    A limited comparative study of undergraduate homosexual males and control males were compared on referral source, therapy referral, academic interest and achievement, ordinal position, perceived relationship with parents, and personality adjustment as measured by the MMPI. Several differences were found and implications for treatment were…

  18. 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…

  19. How the Male Body Works Sexually

    MedlinePlus

    ... Cancer Sex and the Man With Cancer Cancer, Sex, and the Male Body Cancer and sex When you first found out you had cancer, ... remains. How a man’s body works The male sex organs A man’s genitals and sex organs are ...

  20. 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…

  1. 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…

  2. 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…

  3. Sexual Attractiveness of Males and Females.

    ERIC Educational Resources Information Center

    Taylor, Peggy; And Others

    The most important characteristics for females judging the attractiveness of males, and for males judging females, were eyes, body build and facial complexion. Previously, females tended to place less importance on physical components of attraction for both themselves and men. Possible interpretations are: (1) women have become more egalitarian…

  4. 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…

  5. 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…

  6. 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.

  7. Male Infertility and Its Causes in Human

    PubMed Central

    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. PMID:22046184

  8. 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.

  9. Ocean acidification changes the male fitness landscape

    PubMed Central

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

    2016-01-01

    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. PMID:27531458

  10. Stress promotes maleness in hermaphroditic modular animals

    PubMed Central

    Hughes, R. N.; Manríquez, P. H.; Bishop, J. D. D.; Burrows, M. T.

    2003-01-01

    Sex-allocation theory developed for hermaphroditic plants predicts that impaired phenotype or reduced parental survivorship caused by environmental stress should induce relatively greater allocation to the male function. We provide experimental evidence of stress-induced maleness, already well documented in flowering plants, in a modular animal. By using cloned copies of replicate genotypes, we show that the marine bryozoan Celleporella hyalina increases the ratio of male to female modules in response to diverse environmental stressors. Mating trials confirmed that paternity is determined by fair-raffle sperm competition, which should obviate local mate competition at characteristic population density and promote the advantage of increased male allocation. The demonstrated similarity to plants transcends specific physiological pathways and suggests that stress-induced bias toward male function is a general response of hermaphroditic modular organisms to impaired prospects for parental productivity or survival. PMID:12930903

  11. Developmental trajectories to male borderline personality disorder.

    PubMed

    Goodman, Marianne; Patel, Uday; Oakes, Allison; Matho, Andrea; Triebwasser, Joseph

    2013-12-01

    Due to the higher diagnostic prevalence of borderline personality disorder (BPD) in females, there exists a dearth of literature on the manifestations of BPD in men and minimal information on male developmental trajectories to the disorder. To identify precursors of BPD in males, surveys were administered to parents about their BPD male offspring and non-BPD male siblings. Questions covered aspects of probands' lives from infancy to late adolescence. BPD offspring were identified through self-reported clinical diagnoses and standardized diagnostic criteria embedded within the survey. A total of 263 male offspring (97 meeting strict criteria for BPD and 166 non-BPD siblings) were studied. The authors found that parents describe the early emergence of a constellation of symptoms in their BPD sons that include separation anxiety starting in infancy, body image concerns in childhood, and impulsivity, emptiness, and odd thinking in adolescence. This trajectory differs from the developmental course found in females diagnosed with BPD.

  12. Mucinous carcinoma occurring in the male breast.

    PubMed

    Ishida, Mitsuaki; Umeda, Tomoko; Kawai, Yuki; Mori, Tsuyoshi; Kubota, Yoshihiro; Abe, Hajime; Iwai, Muneo; Yoshida, Keiko; Kagotani, Akiko; Tani, Tohru; Okabe, Hidetoshi

    2014-02-01

    Male breast carcinoma is an uncommon neoplasm, accounting for 0.6% of all breast carcinomas. Invasive ductal carcinoma of no special type is the most common type of male breast carcinoma, and mucinous carcinoma occurring in the male breast is extremely rare. In the present study, we report a case of mucinous carcinoma of the male breast and discuss the clinicopathological features of this type of tumor. A 63-year-old Japanese male presented with a gradually enlarged nodule in the right breast. The resected breast specimen revealed pure mucinous carcinoma and immunohistochemical analyses demonstrated that tumor cells were positive for estrogen receptor (ER), but negative for progesterone receptor (PgR). In addition, HER2 expression was not amplified. Pure mucinous carcinoma is generally associated with a low incidence of lymph node or distant metastases, and excellent disease-free survival in females. However, certain cases of this type of tumor with axillary lymph node metastasis in the male breast have been reported. In addition, the immunoprofiles of mucinous carcinoma in males are fundamentally the same as those in females. More than 90% of cases show positive immunoreactivity for ER and/or PgR, and HER2 expression is not amplified. However, it has been reported that breast cancer in males is more frequently positive for ER than in females, and has less HER2 overexpression. The high rate of hormone receptor-positive breast cancer in males is considered to be due to similar conditions as those in breast cancer in postmenopausal women. The pathogenesis of male breast carcinoma, including mucinous carcinoma, remains unclear; therefore, additional clinicopathological studies are required.

  13. Plastic responses of male Drosophila melanogaster to the level of sperm competition increase male reproductive fitness

    PubMed Central

    Bretman, Amanda; Fricke, Claudia; Chapman, Tracey

    2009-01-01

    Evolutionary and plastic responses by males to the level of sperm competition (SC) are reported across widespread taxa, but direct tests of the consequences for male reproductive success in a competitive context are lacking. We varied male perception of SC to examine the effect on male competitive reproductive success and to test whether the outcomes were as predicted by theory. Exposure to rival males prior to mating increased a male's ejaculate investment (measured as mating duration); by contrast, exposure to rival males in the mating arena decreased mating duration. The results therefore suggested that SC intensity is important in shaping male responses to SC in this system, although the patterns were not strictly in accord with existing theory. We then tested whether males that responded to the level of SC had higher reproductive fitness in a competitive context. We found that males kept with rivals prior to mating again mated for longer; furthermore, they achieved significantly higher paternity share regardless of whether they were the first or second males to mate with a female. The plastic strategies employed by males therefore resulted in significantly increased reproductive success in a competitive context, even following subsequent rematings in which the majority of sperm were displaced. PMID:19324834

  14. 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.

  15. Sexually antagonistic selection in human male homosexuality.

    PubMed

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

    2008-06-18

    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.

  16. 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.

  17. Variations in Antioxidant Genes and Male Infertility

    PubMed Central

    Yu, Bolan; Huang, Zhaofeng

    2015-01-01

    Oxidative stress and reactive oxygen species (ROS) are generated from both endogenous and environmental resources, which in turn may cause defective spermatogenesis and male infertility. Antioxidant genes, which include catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST), nitric oxide synthase (NOS), nuclear factor erythroid 2-related factor 2 (NRF2), and superoxide dismutase (SOD), play important roles in spermatogenesis and normal sperm function. In this review, we discuss the association between variations in major antioxidant genes and male infertility. Numerous studies have suggested that genetic disruption or functional polymorphisms in these antioxidant genes are associated with a higher risk for male infertility, which include low sperm quality, oligoasthenoteratozoospermia, oligozoospermia, and subfertility. The synergistic effects of environmental ROS and functional polymorphisms on antioxidant genes that result in male infertility have also been reported. Therefore, variants in antioxidant genes, which independently or synergistically occur with environmental ROS, affect spermatogenesis and contribute to the occurrence of male infertility. Large cohort and multiple center-based population studies to identify new antioxidant genetic variants that increase susceptibility to male infertility as well as validate its potential as genetic markers for diagnosis and risk assessment for male infertility for precise clinical approaches are warranted. PMID:26618172

  18. 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

  19. Two thresholds, three male forms result in facultative male trimorphism in beetles.

    PubMed

    Rowland, J Mark; Emlen, Douglas J

    2009-02-06

    Male animals of many species deploy conditional reproductive strategies that contain distinct alternative phenotypes. Such facultatively expressed male tactics are assumed to be due to a single developmental threshold mechanism switching between the expression of two alternative phenotypes. However, we discovered a clade of dung beetles that commonly expresses two threshold mechanisms, resulting in three alternative phenotypes (male trimorphism). Once recognized, we found trimorphism in other beetle families that involves different types of male weapons. Evidence that insects assumed to be dimorphic can express three facultative male forms suggests that we need to adjust how we think about animal mating systems and the evolution of conditional strategies.

  20. Conflict over Male Parentage in Social Insects

    PubMed Central

    Keller, Laurent

    2004-01-01

    Mutual policing is an important mechanism that maintains social harmony in group-living organisms by suppressing the selfish behavior of individuals. In social insects, workers police one another (worker-policing) by preventing individual workers from laying eggs that would otherwise develop into males. Within the framework of Hamilton's rule there are two explanations for worker-policing behavior. First, if worker reproduction is cost-free, worker-policing should occur only where workers are more closely related to queen- than to worker-produced male eggs (relatedness hypothesis). Second, if there are substantial costs to unchecked worker reproduction, worker-policing may occur to counteract these costs and increase colony efficiency (efficiency hypothesis). The first explanation predicts that patterns of the parentage of males (male parentage) are associated with relatedness, whereas the latter does not. We have investigated how male parentage varies with colony kin structure and colony size in 50 species of ants, bees, and wasps in a phylogenetically controlled comparative analysis. Our survey revealed that queens produced the majority of males in most of the species and that workers produced more than half of the males in less than 10% of species. Moreover, we show that male parentage does not vary with relatedness as predicted by the relatedness hypothesis. This indicates that intra- and interspecific variation in male parentage cannot be accounted for by the relatedness hypothesis alone and that increased colony efficiency is an important factor responsible for the evolution of worker-policing. Our study reveals greater harmony and more complex regulation of reproduction in social insect colonies than that expected from simple theoretical expectations based on relatedness only. PMID:15328531

  1. Overview and trends in male grooming.

    PubMed

    Elsner, P

    2012-03-01

    The use of cosmetics and medical cosmetic procedures by men has been widely ignored in dermatological research in the past, but it is finding increasing attention. As men are changing their habits and increasingly tend to use cosmetic products, the dermatologist will be asked for expert advice regarding efficacy and safety of cosmetics for male skin. For this service, dermatologists need to be aware of anatomical and physiological differences between male and female skin, about specific environmental stress factors affecting male skin, about cosmetic practices and product use especially regarding shaving, and about the counselling needs in men relating to protective cosmetic use.

  2. 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.

  3. 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.

  4. Male mammals respond to a risk of sperm competition conveyed by odours of conspecific males

    NASA Astrophysics Data System (ADS)

    delBarco-Trillo, Javier; Ferkin, Michael H.

    2004-09-01

    Sperm competition occurs when a female copulates with two or more males and the sperm of those males compete within the female's reproductive tract to fertilize her eggs. The frequent occurrence of sperm competition has forced males of many species to develop different strategies to overcome the sperm of competing males. A prevalent strategy is for males to increase their sperm investment (total number of sperm allocated by a male to a particular female) after detecting a risk of sperm competition. It has been shown that the proportion of sperm that one male contributes to the sperm pool of a female is correlated with the proportion of offspring sired by that male. Therefore, by increasing his sperm investment a male may bias a potential sperm competition in his favour. Here we show that male meadow voles, Microtus pennsylvanicus, increase their sperm investment when they mate in the presence of another male's odours. Such an increase in sperm investment does not occur by augmenting the frequency of ejaculations, but by increasing the amount of sperm in a similar number of ejaculations.

  5. Zinc feeding and fertility of male rats.

    PubMed

    Samanta, K; Pal, B

    1986-01-01

    Supplementation of the diet of adult male rats with 4,000 ppm zinc as ZnSO4 for 30 to 32 days increased the zinc content in the testis and sperm by 25 and 18 per cent respectively, but did not change the same in accessory reproductive tissues, e.g. epididymis, seminal vesicle and prostate. The incidence of conception from mating between normal females and zinc fed males was lower as compared to mating between normal females and control males. This observation indicated reduced fertility of the males resulting from additional zinc ingestion. Motility of the sperm collected from the epididymis (tail) of the zinc treated rats was found to be inhibited. It has been suggested that excess zinc in the sperm was responsible for their poor motility and hence a reduced fertilising capacity.

  6. 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.

  7. Male Pectoral Implants: Radiographic Appearance of Complications

    PubMed Central

    Kuzmiak, Cherie M; Damitz, Lynn; Burke, Rachael; Hwang, Michael

    2016-01-01

    There has been a significant surge in aesthetic chest surgery for men in the last several years. Male chest enhancement is performed with surgical placement of a solid silicone pectoral implant. In the past, male chest correction and implantation were limited to the treatment of men who had congenital absence or atrophy of the pectoralis muscle and pectus excavatum deformity. But today, the popularization of increased chest and pectoral size fostered by body builders has more men desiring chest correction with implantation for non-medical reasons. We present a case of a 44-year-old, male with a displaced left pectoral implant with near extrusion and with an associated peri-implant soft tissue mass and fluid collection. While the imaging of these patients is uncommon, our case study presents the radiographic findings of male chest enhancement with associated complications. PMID:27200162

  8. A Description of Males of Hoplolaimus columbus

    PubMed Central

    Fassuliotis, G.

    1974-01-01

    The male of the Columbia lance nematode, Hoplolaimus columbus, is described and illustrated from a harvested soybean field in Holly Hill, South Carolina. It is morphologically similar to the female, except for reproductive structures. PMID:19308111

  9. DNA methylation in spermatogenesis and male infertility

    PubMed Central

    Cui, Xiangrong; Jing, Xuan; Wu, Xueqing; Yan, Meiqin; Li, Qiang; Shen, Yan; Wang, Zhenqiang

    2016-01-01

    Infertility is a significant problem for human reproduction, with males and females equally affected. However, the molecular mechanisms underlying male infertility remain unclear. Spermatogenesis is a highly complex process involving mitotic cell division, meiosis cell division and spermiogenesis; during this period, unique and extensive chromatin and epigenetic modifications occur to bring about specific epigenetic profiles in spermatozoa. It has recently been suggested that the dysregulation of epigenetic modifications, in particular the methylation of sperm genomic DNA, may serve an important role in the development of numerous diseases. The present study is a comprehensive review on the topic of male infertility, aiming to elucidate the association between sperm genomic DNA methylation and poor semen quality in male infertility. In addition, the current status of the genetic and epigenetic determinants of spermatogenesis in humans is discussed. PMID:27698683

  10. 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.

  11. 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.

  12. Male gamete biology in flowering plants.

    PubMed

    Russell, Scott D; Gou, Xiaoping; Wei, Xiaoping; Yuan, Tong

    2010-04-01

    Flowering plant reproduction is characterized by double fertilization, in which two diminutive brother sperm cells initiate embryo and endosperm. The role of the male gamete, although studied structurally for over a century at various levels, is still being explored on a molecular and cellular level. The potential of the male to influence development has been historically underestimated and the reasons for this are obvious: limitations provided by maternal imprinting, the much greater cellular volume of female gametes and the general paucity of paternal effects. However, as more is known about molecular expression of chromatin-modifying proteins, ubiquitin pathway proteins and transcription factors in sperm cells, as well as their ability to achieve effect by intaglio expression, passing transcripts directly into translation, the role of the male is likely to expand. Much of the expression in the male germline that appears to be distinct from patterns of pollen vegetative cell expression may be the result of chromosomal level regulation of transcription.

  13. The male facelift: considerations and techniques.

    PubMed

    Papel, I D; Lee, E

    1996-07-01

    Facelift in the male patient presents unique challenges with respect to maintenance of normal hairline and management of bearded skin. With careful psychological preparation, surgical planning, and attention to detail, these male characteristics can be retained with a good rejuvenative result. The combination of a deep-plane rhytidectomy technique with modified incisions and endoscopic brow intervention has provided the authors with consistent surgical results. Complications have been minimal, with no significant hematomas, skin loss, or nerve injuries to date.

  14. Lifestyle, environment, and male reproductive health.

    PubMed

    Barazani, Yagil; Katz, Benjamin Farrel; Nagler, Harris Mark; Stember, Doron Sol

    2014-02-01

    A large number of environmental and lifestyle factors may negatively affect spermatogenesis and male fertility. This article enumerates the current state of knowledge regarding those that have been identified, and extrapolates the predicted magnitude of these effects over the next 20 years based on current societal trends. However, it is likely that additional factors have yet to be recognized. Additional research is needed to further define and clarify environmental factors that affect male fertility in order to mitigate their effects.

  15. 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.

  16. 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

  17. Male motion coordination in anopheline mating swarms

    PubMed Central

    Shishika, Daigo; Manoukis, Nicholas C.; Butail, Sachit; Paley, Derek A.

    2014-01-01

    The Anopheles gambiae species complex comprises the primary vectors of malaria in much of sub-Saharan Africa. Most of the mating in these species occurs in swarms composed almost entirely of males. Intermittent, organized patterns in such swarms have been observed, but a detailed description of male-male interactions has not previously been available. We identify frequent, time-varying interactions characterized by periods of parallel flight in data from 8 swarms of Anopheles gambiae and 3 swarms of Anopheles coluzzii filmed in 2010 and 2011 in the village of Donéguébogou, Mali. We use the cross correlation of flight direction to quantify these interactions and to induce interaction graphs, which show that males form synchronized subgroups whose size and membership change rapidly. A swarming model with damped springs between each male and the swarm centroid shows good agreement with the correlation data, provided that local interactions represented by damping of relative velocity between males are included. PMID:25212874

  18. Male pygmy hippopotamus influence offspring sex ratio

    PubMed Central

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

    2012-01-01

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

  19. Roaring function in male goitered gazelles.

    PubMed

    Blank, D A; Ruckstuhl, K; Yang, W

    2014-07-01

    Most of the vocalizations of Antilopinae males are soft and usually only heard from a very close distance. The goitered gazelle is a rare exception to this rule, and during the rutting period territorial males of this species are among the noisiest antelopes. Rutting vocalization is such an essential part of the rutting behavior in goitered gazelle that adult males have a hypertrophic larynx, the muscle tissues of which increase considerably in size during the rut. We were interested in the frequency and variance with which male goitered gazelles emit their calls depending on an animal's age, reproductive status and time of the year in order to understand the main function of the rutting vocalizations. We found that roaring was mostly related to courting displays, while vocalizations during aggressive displays were less frequent in male-male interactions. Acoustic signals likely enhance courtship displays and also may aid in accelerating female ovulation, promoting synchronization of breeding cycles during the mating and birthing periods, which last only several days for most of the females in our population. We discuss the potential benefits of such behaviors and compare it to other species living in similarly extreme environments.

  20. Male urethral diverticulum uncommon entity: Our experience

    PubMed Central

    Thakur, Naveen; Sabale, Vilas Pandurang; Mane, Deepak; Mullay, Abhirudra

    2016-01-01

    Out pouching of the urethral wall could be congenital or acquired. Male urethral diverticulum (UD) is a rare entity. We present 2 cases of acquired and 1 case of congenital male UD. Case 1A: 40 year male presented with SPC and dribbling urine. Clinically he had hard perineal swelling. RGU revealed large diverticulum in proximal bulbar, irregular narrow distal urethra and stricture just beyond diverticulum. Managed with perineal exploration, stone removal, diverticulum repair and urethroplasty using excess diverticular wall. Case 2A: 30 year male with obstructive lower urinary tract symptoms (LUTS). Retrograde urethrogram (RGU) revealed bulbar urethral diverticulum akin to anterior urethral valve, managed endoscopically. 1 year follow up urine stream satisfactory. Case 3A: 27 year male previously operated large proximal bulbar urethral stone with incontinence. RGU large proximal bulbar UD with wide open sphincter. Treated with excision of excess diverticular wall and penile clamp with pelvic exercises for incontinence. Congenital UD develops due to imperfect closure of urethral fold, Acquired UDs occurs secondary to stricture, infection, trauma, long standing impacted urethral stones or scrotal / skin flap urethroplasties. RGU and MCU are the best diagnostic technique to confirm and characterize the UD. Urethral diverticulectomy with urethral reconstruction is the recommended treatment for UD. UD is a rare entity. Especially in males, congenital are even more rare. Management should be individualized. Surgery can involve innovation and/or surgical modifications. We used excess diverticular flap for stricture urethroplasty in one case. PMID:28057997

  1. Male pygmy hippopotamus influence offspring sex ratio.

    PubMed

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

    2012-02-28

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

  2. Familiality of female and male homosexuality.

    PubMed

    Bailey, J M; Bell, A P

    1993-07-01

    We examined data from a large cohort of homosexual and heterosexual females and males concerning their siblings' sexual orientations. As in previous studies, both male and female homosexuality were familial. Homosexual females had an excess of homosexual brothers compared to heterosexual subjects, thus providing evidence that similar familial factors influence both male and female homosexuality. Furthermore, despite the large sample size, homosexual females and males did not differ significantly from each other in their proportions of either homosexual sisters or homosexual brothers. Thus, results were most consistent with the possibility that similar familial factors influence male and female sexual orientation. However, because results conflicted with those of some other studies, and because siblings' sexual orientations were obtained in a manner likely to yield more errors than in these other, smaller studies, further work is needed using large samples and more careful methods before the degree of cofamiliality of male and female homosexuality can be resolved definitively. We also examined whether some parental influences comprised shared environmental effects on sexual orientation. Scales attempting to measure such influences failed to distinguish subjects with homosexual siblings from subjects with only heterosexual siblings and, thus, did not appear to measure shared environmental determinants of sexual orientation.

  3. Male coercive mating in externally fertilizing species: male coercion, female reluctance and explanation for female acceptance

    PubMed Central

    Matsumoto, Yukio; Takegaki, Takeshi

    2016-01-01

    Male coercive mating exerts a strong evolutionary pressure on mating-related traits of both sexes. However, it is extremely rare in externally fertilizing species probably because the male mating behaviour is incomplete until females release their eggs. Here we showed that males of the externally fertilizing fish Rhabdoblennius nitidus coercively confine females to the nests until spawning, and investigated why females accept male coercive mating. The females entered the males’ nests following male courtship displays, but they usually tried to escape when there were no eggs because males tended to cannibalize all the eggs when there were few. Most males that used small, tight nests acquired new eggs but with experimentally enlarged nests, 90% of the males without eggs failed to confine the females. Spawning tended to occur during the early/late spawning period in nests with no eggs (i.e. male coercive mating). In the nests where the first eggs were deposited in the early period, subsequent matings with other females were more likely to occur, whereas in the late period, most parental care of the eggs failed without additional matings. The females that spawned in the late period may have been compelled to accept male coercive mating due to time constraints. PMID:27087584

  4. Male Mosquitoes as Vehicles for Insecticide

    PubMed Central

    Mains, James W.; Brelsfoard, Corey L.; Dobson, Stephen L.

    2015-01-01

    Background The auto-dissemination approach has been shown effective at treating cryptic refugia that remain unaffected by existing mosquito control methods. This approach relies on adult mosquito behavior to spread larvicide to breeding sites at levels that are lethal to immature mosquitoes. Prior studies demonstrate that ‘dissemination stations,’ deployed in mosquito-infested areas, can contaminate adult mosquitoes, which subsequently deliver the larvicide to breeding sites. In some situations, however, preventative measures are needed, e.g., to mitigate seasonal population increases. Here we examine a novel approach that combines elements of autocidal and auto-dissemination strategies by releasing artificially reared, male mosquitoes that are contaminated with an insecticide. Methodology Laboratory and field experiments examine for model-predicted impacts of pyriproxyfen (PPF) directly applied to adult male Aedes albopictus, including (1) the ability of PPF-treated males to cross-contaminate females and to (2) deliver PPF to breeding sites. Principal Findings Similar survivorship was observed in comparisons of PPF-treated and untreated males. Males contaminated both female adults and oviposition containers in field cage tests, at levels that eliminated immature survivorship. Field trials demonstrate an ability of PPF-treated males to transmit lethal doses to introduced oviposition containers, both in the presence and absence of indigenous females. A decline in the Ae. albopictus population was observed following the introduction of PPF-treated males, which was not observed in two untreated field sites. Conclusions/Significance The results demonstrate that, in cage and open field trials, adult male Ae. albopictus can tolerate PPF and contaminate, either directly or indirectly, adult females and immature breeding sites. The results support additional development of the proposed approach, in which male mosquitoes act as vehicles for insecticide delivery

  5. 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

  6. Male-killing bacteria trigger a cycle of increasing male fatigue and female promiscuity.

    PubMed

    Charlat, Sylvain; Reuter, Max; Dyson, Emily A; Hornett, Emily A; Duplouy, Anne; Davies, Neil; Roderick, George K; Wedell, Nina; Hurst, Gregory D D

    2007-02-06

    Sex-ratio distorters are found in numerous species and can reach high frequencies within populations. Here, we address the compelling, but poorly tested, hypothesis that the sex ratio bias caused by such elements profoundly alters their host's mating system. We compare aspects of female and male reproductive biology between island populations of the butterfly Hypolimnas bolina that show varying degrees of female bias, because of a male-killing Wolbachia infection. Contrary to expectation, female bias leads to an increase in female mating frequency, up to a point where male mating capacity becomes limiting. We show that increased female mating frequency can be explained as a facultative response to the depleted male mating resources in female biased populations. In other words, this system is one where male-killing bacteria trigger a vicious circle of increasing male fatigue and female promiscuity.

  7. Drosophila TRPA channel painless inhibits male-male courtship behavior through modulating olfactory sensation.

    PubMed

    Wang, Kaiyu; Guo, Yanmeng; Wang, Fei; Wang, Zuoren

    2011-01-01

    The Drosophila melanogaster TRPA family member painless, expressed in a subset of multidendritic neurons embeding in the larval epidermis, is necessary for larval nociception of noxious heat or mechanical stimuli. However, the function of painless in adult flies remains largely unknown. Here we report that mutation of painless leads to a defect in male-male courtship behavior and alteration in olfaction sensitivity in adult flies. Specific downregulation of the expression of the Painless protein in the olfactory projection neurons (PNs) of the antennal lobes (ALs) resulted in a phenotype resembling that found in painless mutant flies, whereas overexpression of Painless in PNs of painless mutant males suppressed male-male courtship behavior. The downregulation of Painless exclusively during adulthood also resulted in male-male courtship behavior. In addition, mutation of the painless gene in flies caused changes in olfaction, suggesting a role for this gene in olfactory processing. These results indicate that functions of painless in the adult central nervous system of Drosophila include modulation of olfactory processing and inhibition of male-male courtship behavior.

  8. 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.

  9. Interpretation of male rat renal tubule tumors.

    PubMed Central

    Rodgers, I S; Baetcke, K P

    1993-01-01

    Based on an analysis of recent scientific studies, a Technical Panel of the U.S. Environmental Protection Agency's (EPA) Risk Assessment Forum recently advised EPA risk assessors against using information on certain male rat renal tubule tumors to assess human risk under conditions specified in a new Forum report. Risk assessment approaches generally assume that chemicals producing tumors in laboratory animals are a potential cancer hazard to humans. For most chemicals, including classical rodent kidney carcinogens such as N-ethyl-N-hydroxyethylnitrosamine, this extrapolation remains appropriate. Some chemicals, however, induce accumulation of alpha 2u-globulin (alpha 2u-g), a low molecular weight protein, in the male rat kidney. The alpha 2u-g accumulation initiates a sequence of events that appears to lead to renal tubule tumor formation. Female rats and other laboratory mammals administered the same chemicals do not accumulate low molecular weight protein in the kidney, and they do not develop renal tubule tumors. Because humans appear to be more like other laboratory animals than like the male rat, in this special situation, the male rat is not a good model for assessing human risk. The Forum report stresses the need for full scrutiny of a substantial set of data to determine when it is reasonable to presume that renal tumors in male rats are linked to a process involving alpha 2u-g accumulation and to select appropriate procedures for estimating human risks under such circumstances. PMID:7517352

  10. Mammography Findings of Male Breast Diseases

    PubMed Central

    Şafak, Kadihan Yalçın

    2015-01-01

    Over the past 2 decades, the percentage of men presenting with breast complaints has increased from 0.8% to 2.4%, and men now account for 1% of all breast cancer cases. The most common male breast mass is gynecomastia, followed by lipoma and epidermal inclusion cysts. Because there is a paucity of parenchyma as compared with the female breast, the malignancy rapidly progresses to the next stage, with the appearance of secondary signs like nipple retraction, fixation to deeper tissues, skin ulceration or adenopathy. Diagnostic evaluation is needed only when the palpable mass is unilateral, hard, fixed, peripheral to the nipple, or associated with nipple discharge, skin changes, or lymphadenopathy. Male breast cancer usually occurs in a subareolar location or is positioned eccentric to the nipple; occasionally, it occurs in a peripheral position. Secondary signs like skin thickening, nipple retraction, and axillary lymphadenopathy may be seen. Microcalcifications can occur. Mammography can accurately distinguish between malignant and benign male breast disease. Radiologists are generally less familiar with breast disease in males compared with females. In this article, we discuss the clinical, and mammographic features of a variety of benign and malignant diseases that can occur in the male breast.

  11. Impact of Inflammation on Male Reproductive Tract

    PubMed Central

    Azenabor, Alfred; Ekun, Ayodele Oloruntoba; Akinloye, Oluyemi

    2015-01-01

    Fertility in the male is dependent on the proper production of sperm cells. This process, called spermatogenesis is very complex and involves the synchronization of numerous factors. The presence of pro–inflammatory cytokines, tumor necrosis factor-alpha (TNF–α), interleukin–1 alpha (IL–1 α) and interleukin 1 beta (IL–1 β) cytokines in the male reproductive tract (testis, epididymis and sperm) may have certain physiological functions. However, when the levels of these cytokines are higher than normal, as seen in conditions of inflammation, they become very harmful to sperm production. Moreover, inflammation is also associated with oxidative stress and the latter is well known to impair sperm function. Epidemiological studies regarding male infertility have revealed that more and more infertile men suffer from acute or chronic inflammation of the genitourinary tract, which often occurs without any symptoms. The inflammatory reactions within the male genital tract are inevitably connected with oxidative stress. Oxidative stress, especially in sperm, is harmful because it damages sperm DNA and causes apoptosis in sperm. This article reviewed the suggested mechanisms and contribution of inflammation to male infertility. In addition, the review was further strengthened by discussing how inflammation affects both fertility and assisted reproductive technologies (ART). PMID:26913230

  12. Mitochondria, maternal inheritance, and male aging.

    PubMed

    Camus, M Florencia; Clancy, David J; Dowling, Damian K

    2012-09-25

    The maternal transmission of mitochondrial genomes invokes a sex-specific selective sieve, whereby mutations in mitochondrial DNA can only respond to selection acting directly on females. In theory, this enables male-harming mutations to accumulate in mitochondrial genomes when these same mutations are neutral, beneficial, or only slightly deleterious in their effects on females. Ultimately, this evolutionary process could result in the evolution of male-specific mitochondrial mutation loads; an idea previously termed Mother's Curse. Here, we present evidence that the effects of this process are broader than hitherto realized, and that it has resulted in mutation loads affecting patterns of aging in male, but not female Drosophila melanogaster. Furthermore, our results indicate that the mitochondrial mutation loads affecting male aging generally comprise numerous mutations over multiple sites. Our findings thus suggest that males are subject to dramatic consequences that result from the maternal transmission of mitochondrial genomes. They implicate the diminutive mitochondrial genome as a hotspot for mutations that affect sex-specific patterns of aging, thus promoting the idea that a sex-specific selective sieve in mitochondrial genome evolution is a contributing factor to sexual dimorphism in aging, commonly observed across species.

  13. Genetics Home Reference: sensorineural deafness and male infertility

    MedlinePlus

    ... deafness and male infertility sensorineural deafness and male infertility Enable Javascript to view the expand/collapse boxes. ... All Close All Description Sensorineural deafness and male infertility is a condition characterized by hearing loss and ...

  14. Natural variation in plep-1 causes male-male copulatory behavior in C. elegans

    PubMed Central

    Noble, Luke M.; Chang, Audrey; McNelis, Daniel; Kramer, Max; Yen, Mimi; Nicodemus, Jasmine P.; Riccardi, David D.; Ammerman, Patrick; Phillips, Matthew; Islam, Tangirul; Rockman, Matthew V.

    2015-01-01

    Summary In sexual species, gametes have to find and recognize one another. Signaling is thus central to sexual reproduction and involves a rapidly evolving interplay of shared and divergent interests [1-4]. Among Caenorhabditis nematodes, three species have evolved self-fertilization, changing the balance of intersexual relations [5]. Males in these androdioecious species are rare, and the evolutionary interests of hermaphrodites dominate. Signaling has shifted accordingly, with females losing behavioral responses to males [6, 7] and males losing competitive abilities [8, 9]. Males in these species also show variable same-sex and autocopulatory mating behaviors [6, 10]. These behaviors could have evolved by relaxed selection on male function, accumulation of sexually antagonistic alleles that benefit hermaphrodites and harm males [5, 11], or neither of these, because androdioecy also reduces the ability of populations to respond to selection [12-14]. We have identified the genetic cause of a male-male mating behavior exhibited by geographically dispersed C. elegans isolates, wherein males mate with and deposit copulatory plugs on one another's excretory pores. We find a single locus of major effect that is explained by segregation of a loss-of-function mutation in an uncharacterized gene, plep-1, expressed in the excretory cell in both sexes. Males homozygous for the plep-1 mutation have excretory pores that are attractive or receptive to copulatory behavior of other males. As excretory pore plugs are injurious and hermaphrodite activity is compromised in plep-1 mutants, the allele may be unconditionally deleterious, persisting in the population because the species' androdioecious mating system limits the reach of selection. PMID:26455306

  15. High male fertility in males of a subdioecious shrub in hand-pollinated crosses

    PubMed Central

    Wang, Hui; Matsushita, Michinari; Tomaru, Nobuhiro; Nakagawa, Michiko

    2016-01-01

    Female reproductive success in females versus hermaphrodites has been well documented. However, documenting a potential advantage in male fertility of male versus hermaphrodite individuals in subdioecious species is also essential for understanding the evolutionary pathway toward dioecy from hermaphroditism via gynodioecy. Siring success in terms of fruit set, fruit mass, number of seeds and mean seed mass was compared by hand-pollinated crosses in the subdioecious shrub Eurya japonica. The pollen was from male and hermaphrodite individuals, and the pollen recipients were females and hermaphrodites. Seed quality was also evaluated in terms of seed germination rate, seed germination day and seedling survival. Overall, pollen from males sired more fruits of larger size and more seeds than did pollen from hermaphrodites. The male advantage was observed when pollen recipients were females, whereas no effect was found in hermaphrodite recipients. Pollen from males also produced better quality seeds with higher germination rate and sooner germination day. Although these results could also be explained by a higher pollen load for crosses with male pollen donors, we took care to saturate the stigma regardless of the pollen donor. Therefore, these results suggest that male individuals of E. japonica have advantages in male fertility in terms of both quantity and quality. Our previous studies indicated that females exhibit higher female reproductive success compared with hermaphrodites. Thus, both the female and male functions of hermaphrodites are outperformed by females and males, respectively, raising the possibility that the subdioecious E. japonica at this study site is entering the transitional phase to dioecy along the gynodioecy–dioecy pathway. PMID:27658818

  16. Alcohol references on undergraduate males' Facebook profiles.

    PubMed

    Egan, Katie G; Moreno, Megan A

    2011-09-01

    Perceived peer alcohol use is a predictor of consumption in college males; frequent references to alcohol on Facebook may encourage alcohol consumption. Content analysis of college males' Facebook profiles identified references to alcohol. The average age of 225 identified profiles was 19.9 years. Alcohol references were present on 85.3% of the profiles; the prevalence of alcohol was similar across each undergraduate grade. The average number of alcohol references per profile was 8.5 but increased with undergraduate year (p = .003; confidence interval = 1.5, 7.5). Students who were of legal drinking age referenced alcohol 4.5 times more than underage students, and an increase in number of Facebook friends was associated with an increase in displayed alcohol references (p < .001; confidence interval = 0.009, 0.02). Facebook is widely used in the college population; widespread alcohol displays on Facebook may influence social norms and cause increases in male college students' alcohol use.

  17. Occupation-related male infertility: a review.

    PubMed

    Henderson, J; Baker, H W; Hanna, P J

    1986-04-01

    Male infertility is a significant health problem for which few aetiological factors have been identified. The role of occupational exposure is largely unknown but certain substances such as 1,2-dibromo-3-chloropropane, oestrogen, heat, lead and microwaves have been reported to impair spermatogenesis in workers. Other agents which interfere with reproductive performance in experimental animals such as cadmium, manganese, organophosphates and some solvents have not been studied sufficiently for their occupational risks to be fully known. Some occupational exposures, extensively studied, appear to convey little or no risk to male fertility including radiological exposure, anaesthetic gases and Agent Orange. It is clear that the range of substances potentially hazardous to male reproduction is great but the number of agents for which the evidence is unequivocal is very small.

  18. Interventional Radiology of Male Varicocele: Current Status

    SciTech Connect

    Iaccarino, Vittorio 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 and 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.

  19. Chromatin remodelling during male gametophyte development.

    PubMed

    Borg, Michael; Berger, Frédéric

    2015-07-01

    The plant life cycle alternates between a diploid sporophytic phase and haploid gametophytic phase, with the latter giving rise to the gametes. Male gametophyte development encompasses two mitotic divisions that results in a simple three-celled structure knows as the pollen grain, in which two sperm cells are encased within a larger vegetative cell. Both cell types exhibit a very different type of chromatin organization - highly condensed in sperm cell nuclei and highly diffuse in the vegetative cell. Distinct classes of histone variants have dynamic and differential expression in the two cell lineages of the male gametophyte. Here we review how the dynamics of histone variants are linked to reprogramming of chromatin activities in the male gametophyte, compaction of the sperm cell genome and zygotic transitions post-fertilization.

  20. Pilot-error accidents: male vs female.

    PubMed

    Vail, G J; Ekman, L G

    1986-12-01

    In this study, general aviation accident records from the files of the National Transportation Safety Board (NTSB), have been analysed by gender to observe the number and rate of pilot-error related accidents from 1972 to 1981 inclusive. If both females and males have no difference in performance, then data would have indicated similarities of accident rates and types of injuries. Males had a higher rate of accidents than females, and a higher portion of the male accidents resulted in fatalities or serious injuries than for females. Type of certificate, age, total flight time, flight time in type of aircraft, phase of operation, category of flying, degree of injury, specific cause factors, cause factor miscellaneous acts/conditions were analysed, taking the total number of United States Active Civilian General Aviation Pilots into consideration. The data did indicate a difference in all variables.

  1. Male pelvic floor: history and update.

    PubMed

    Dorey, Grace

    2005-08-01

    Our understanding of the male pelvic floor has evolved over more than 2,000 years. Gradually medical science has sought to dispel ancient myths and untruths. The male pelvic floor has many diverse functions. Importantly, it helps to support the abdominal contents, maintains urinary and fecal continence, and plays a major role in gaining and maintaining penile erection. Weakness of the male pelvic floor muscles may cause urinary and fecal incontinence and erectile dysfunction. Function may be restored in each of these areas by a comprehensive pelvic floor muscle training program. Spasm of the pelvic floor muscles may produce pain and require relaxation techniques. Additional research is needed to add further evidence to our knowledge base.

  2. Aesthetic facial surgery for the asian male.

    PubMed

    Lam, Samuel M

    2005-11-01

    Cosmetic surgery of the Asian face has become increasingly popular in the Far East and the West. The Asian male identity has undergone an evolution in Western media toward a more positive change. The standards of beauty have also changed, being defined by more multicultural models and styles of dress than before. To undertake cosmetic surgery of the Asian face, particularly of the Asian male, requires a different psychological understanding of the individual as well as an entirely different surgical technique in most cases. This brief article does not delve into the technical details of each procedure but concentrates on the salient differences in how to approach the Asian male patient for each of the different procedures, including Asian blepharoplasty, augmentation rhinoplasty, lip reduction, dimple fabrication, otoplasty, facial contouring and aging face procedures, and hair restoration.

  3. Male reproductive proteins and reproductive outcomes.

    PubMed

    Ness, Roberta B; Grainger, David A

    2008-06-01

    Male reproductive proteins (MRPs), associated with sperm and semen, are the moieties responsible for carrying male genes into the next generation. Evolutionary biologists have focused on their capacity to control conception. Immunologists have shown that MRPs cause female genital tract inflammation as preparatory for embryo implantation and placentation. These observations argue that MRPs are critically important to reproductive success. Yet the impact of male reproductive proteins on obstetrical outcomes in women is largely unstudied. Epidemiologic and clinical observations suggest that shorter-duration exposure to MRPs prior to conception may elevate the risk for preeclampsia. A limited literature has also linked sexual behavior to bacterial vaginosis and preterm birth. We offer a clinical opinion that MRPs may have broad implications for successful reproduction, potentially involved in the composition of vaginal microflora, risks of preterm birth and preeclampsia, and success of assisted reproduction.

  4. Developmental aspects of the male reproductive system

    PubMed Central

    Davies, Jack

    1978-01-01

    The development of the mammalian reproductive system involves: (1) an indifferent or ambisexual stage, in which both the male (Wolffian) and female (Mullerian) duct systems are present; (2) sexual differentiation, in which the phenotypic sex is expressed by the enhancement of Mullerian structures in the female and Wolffian structures in the male and reciprocal suppression of the opposite duct system; (3) cytodifferentiation, in which the epithelial, stromal and muscular features are regionally established; and (4) actual response to endogenous hormones, especially in mammals, such as the human and guinea pig, in which the differentiated tissues respond according to their capability. Specifically in the male, the onset of sexual differentiation is signaled by the elaboration of an androgenlike material (possibly testosterone) and a Mullerian-inhibiting factor from the testis. In the absence of these two influences, or one of them, the reproductive tract remains essentially female in configuration, a normal situation in the female and in abnormal males in which the urogenital sinus and Wolffian structures are incapable of hormonal responses due to the lack of specific enzymes or receptors. Male differentiation in particular involves enlargement of the penis and its canalization by the urethra, scrotal development and descent of the testis, and the formation of accessory glandular structures from the urogenital sinus or Wolffian ducts (bulbourethral gland, seminal vesicles, ampulla, prostate). Remnants of the Mullerian system may persist at the upper pole of the testis and are normally present (uterus masculinus) in relation to the prostatic part of the urethra. The emergence of the characteristic parts of the male reproductive system in higher mammals in relation to phylogeny and the detailed origin of these in individual ontogeny are described. The use of the guinea pig as a model animal system for the study of transplacental effects of hormones (diethylstilbestrol

  5. Male responsibility for reproductive health. Introduction.

    PubMed

    Ndong, I; Finger, W R

    1998-01-01

    Before the advent of the oral contraceptive pill, men were more involved in family planning and other aspects of reproductive health. Then, if a couple wished to practice family planning, they were largely limited to withdrawal, periodic abstinence, and condom use, all practices which require the man's participation. Hormonal methods for women and the subsequent development of IUDs and modern surgical sterilization fostered the development of a family planning services community focused upon women rather than men. The challenge is now to increase the degree of male responsibility for family planning by expanding services in ways which protect the reproductive health of both men and women, and by encouraging greater sensitivity to gender issues. Adding reproductive health services for men can be done without reducing the level of services available for women. However, while PROFAMILIA clinics, which offer a wide range of male reproductive health services, have found ways to encourage male participation, an enormous gap exists between the rhetoric of promoting male involvement and the actual realities of female-oriented reproductive health programs. Obstacles include men's reluctance to use services, lack of knowledge among men about their own and women's sexuality, lack of communication by men about sexuality in their relationships, male beliefs in sexual myths, health providers' and false assumptions and generalizations about men. The authors discuss the need to encourage men to support women's contraceptive choices, to increase communication between partners, to increase the use of male methods, to improve men's behavior for the prevention of STDs, to address men's reproductive health needs, and to encourage men to become more aware of related family issues.

  6. Inbreeding depression in male gametic performance.

    PubMed

    Losdat, S; Chang, S-M; Reid, J M

    2014-06-01

    One key objective in evolutionary ecology is to understand the magnitude of inbreeding depression expressed across sex-specific components of fitness. One major component of male fitness is fertilization success, which depends on male gametic performance (sperm and pollen performance in animals and plants, respectively). Inbreeding depression in male gametic performance could create sex-specific inbreeding depression in fitness, increase the benefit of inbreeding avoidance and reduce the efficacy of artificial insemination and pollination. However, there has been no assessment of the degree to which inbreeding generally depresses male gametic performance and hence post-copulatory or post-pollination fertilization success. Because inbreeding depression is understood to be a property of diploid entities, it is not clear what degree of inbreeding depression in haploid gametic performance should be expected. Here, we first summarize how inbreeding depression in male gametic performance could potentially arise through gene expression in associated diploid cells and/or reduced genetic diversity among haploid gametes. We then review published studies that estimate the magnitude of inbreeding depression in traits measuring components of sperm or pollen quantity, quality and competitiveness. Across 51 published studies covering 183 study traits, the grand mean inbreeding load was approximately one haploid lethal equivalent, suggesting that inbreeding depresses male gametic performance across diverse systems and traits. However, there was an almost complete lack of explicit estimates from wild populations. Future studies should quantify inbreeding depression in systematic sets of gametic traits under naturally competitive and noncompetitive conditions and quantify the degree to which gamete phenotypes and performance reflect haploid vs. diploid gene expression.

  7. 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)

  8. OLDER MALES, COGNITIVE FUNCTION, AND ALCOHOL CONSUMPTION

    PubMed Central

    McDougall, Graham J.; Becker, Heather; Areheart, Kristopher L.

    2008-01-01

    We investigated the question, how do older men who drink alcohol differ from those who do not drink on measures of cognitive function, memory, affect, and health? Of the nonprobability sample of male participants (N = 60), 35 (58%) of the males reported some degree of alcohol consumption. Eleven men had one or more drinks per day, 14 had one or more drinks per week, and 9 were occasional drinkers. The drinkers reported significantly less depression, had higher self-reported general health and vitality, and had higher cognitive performance, cognitive flexibility, and verbal memory, and greater knowledge of memory processes. PMID:16546934

  9. Predictors of dominance in male Betta splendens.

    PubMed

    Bronstein, P M

    1985-03-01

    The formation of dominance/subordinancy relations in pairs of male Siamese fighting fish was examined in six experiments. Dominant animals typically were those fish that built the largest nests and that attacked an image of a live, displaying male most intensely prior to combat. However, pretest performance on an operant task and reaction to an animal's own mirror image were not useful predictors of subsequent dominance. These findings are consistent with the suggestion that domesticated Bettas have a territorial social strategy that includes both nest-building and fighting behaviors.

  10. Giant Intraperitoneal Multiloculated Pseudocyst in a Male

    PubMed Central

    2016-01-01

    Intraperitoneal pseudocysts are rare and may be difficult to differentiate from other malignant neoplasms. Reports of occurrences are mainly associated with long-term intraperitoneal catheter use, intraperitoneal catheter infections, or major pelvic surgery in females, although there are few reported incidences without prior trauma. We present a case of a male patient found to have a 19 × 15 × 9 cm intraperitoneal pseudocyst with other multiloculated areas and a history of a right inguinal hernia repair. After a thorough review of the literature, this is the first multiloculated nonpancreatic pseudocyst reported in a male patient. PMID:27022497

  11. Hate crimes against gay males: an overview.

    PubMed

    Willis, Danny G

    2004-03-01

    As the United States has become more multicultural and diverse, there has been an increase in violence motivated by hate. Hate crimes against gay males are the most prevalent of the hate crimes based on sexual orientation. Hate crimes have their roots in normative, individual, and societal attitudes and ideologies that lead to intimidation, bullying, teasing, physical assault, rape, and murder. This paper provides an overview of the issues specific to hate crime assaults against gay males. Mental health nurses may find this knowledge useful in developing further nursing inquiry, education, and clinical practice related to hate crime and violence prevention.

  12. 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.

  13. Sex-specific inbreeding depression depends on the strength of male-male competition.

    PubMed

    Janicke, Tim; Vellnow, Nikolas; Sarda, Violette; David, Patrice

    2013-10-01

    Inbreeding depression has become a central theme in evolutionary biology and is considered to be a driving force for the evolution of reproductive morphology, physiology, behavior, and mating systems. Despite the overwhelming body of empirical work on the reproductive consequences of inbreeding, relatively little is known on whether inbreeding depresses male and female fitness to the same extent. However, sex-specific inbreeding depression has been argued to affect the evolution of selfing rates in simultaneous hermaphrodites and provides a powerful approach to test whether selection is stronger in males than in females, which is predicted to be the consequence of sexual selection. We tested for sex-specific inbreeding depression in the simultaneously hermaphroditic freshwater snail Physa acuta by comparing the reproductive performance of both sex functions between selfed and outcrossed focal individuals under different levels of male-male competition. We found that inbreeding impaired both male and female reproductive success and that the magnitude of male inbreeding depression exceeded female inbreeding depression when the opportunity for sperm competition was highest. Our study provides the first evidence for sex-specific inbreeding depression in a hermaphroditic animal and highlights the importance of considering the level of male-male competition when assessing sex differences in inbreeding depression.

  14. 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…

  15. Effects of different male remating intervals on the reproductive success of Choristoneura rosaceana males and females.

    PubMed

    Marcotte, Mireille; Delisle, Johanne; McNeil, Jeremy N

    2007-02-01

    The mass of the spermatophore transferred by a previously mated Choristoneura rosaceana male increases with time elapsed since the last mating but, even after 4 days, it never reaches the mass of the spermatophore of a virgin male. However, spermatophore mass is clearly not a good indicator of the male reproductive investment as the quantity of sperm in the second ejaculate of a previously mated male is the same as that of his first, if he is allowed a 2 (eupyrene sperm) to 3 day (apyrene sperm) recovery period. The interval between the first two matings had no influence on female fecundity or longevity but significantly affected fertility if the male had only 1 day to recover. The length of the post-copulatory refractory period was also shorter in females mated with previously mated males than in those mated with virgins, regardless of the male's remating interval. Furthermore, a significant variation in the eupyrene sperm content of the spermatophore transferred by virgin males had no influence on the length of the female refractory period. Globally, these results support the hypothesis that a factor, other than sperm numbers in the spermatheca, is responsible for maintaining the inhibition of pheromone production in this species.

  16. Negotiating the "White Male Math Myth": African American Male Students and Success in School Mathematics

    ERIC Educational Resources Information Center

    Stinson, David W.

    2013-01-01

    This article shows how equity research in mathematics education can be decentered by reporting the "voices" of mathematically successful African American male students as they recount their experiences with school mathematics, illustrating, in essence, how they negotiated the White male math myth. Using post-structural theory, the…

  17. 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…

  18. 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…

  19. 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…

  20. 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)

  1. 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…

  2. Interactions with heterospecific males do not affect how female Mesocricetus hamsters respond to conspecific males

    PubMed Central

    delBarco-Trillo, Javier; Johnston, Robert E.

    2012-01-01

    Reproductive interference includes any interspecific interaction that reduces the fitness of one or both species involved. There are several types of reproductive interference, but they normally involve the direct cost of interacting or mating with heterospecifics. An indirect cost of interacting with heterospecific individuals is a consequent reduction in successful interactions with conspecifics. We tested the hypothesis that being aggressive towards a heterospecific individual will diminish sexual responses towards conspecifics in later encounters. We used two species of Mesocricetus hamsters (Syrian and Turkish hamsters), whose interspecific interactions have previously been determined. We exposed or both exposed and paired Syrian hamster females with a conspecific or a heterospecific male. Five minutes later, we paired all females with a conspecific male and measured the latency to lordosis, the duration of lordosis and any incidence of aggression. We found that (1) interactions with heterospecific males did not affect how females responded to conspecific males in later encounters and (2) previous pairing of female subjects with either conspecific or heterospecific males promoted a faster sexual response by females in subsequent interactions with conspecific males. Thus, aggressive interactions of Syrian hamster females with heterospecific males, contrary to our initial hypothesis, had a positive effect on subsequent interactions with conspecific males. PMID:23439800

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

    PubMed

    Jiguet, Frédéric; Bretagnolle, Vincent

    2014-03-01

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

  4. 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

  5. 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

    2016-07-29

    Background: 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. Methods: 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. Results: 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. Conclusion: 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.

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

    PubMed

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

    2013-08-07

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

  7. 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…

  8. The Political Economy of Black Male Suicides.

    ERIC Educational Resources Information Center

    Stewart, James B.

    1980-01-01

    Presents a framework which merges economic and sociological insights for studying the increasing suicide rate among Black males. Preliminary empirical analysis of the model indicated that a purely economic model must incorporate extra-economic influences to increase its explanatory power. (MK)

  9. 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…

  10. Food Supplement Usage by Adolescent Males.

    ERIC Educational Resources Information Center

    Fleischer, Barbara; Read, Marsha

    1982-01-01

    Adolescent males (N=568) responded to a questionnaire examining their food supplement usage, types of food supplements consumed, reasons for use and non-use, relationship of use to concern for health, and demographic and external factors influencing supplement use. Presents factors related to food supplement usage. (RC)

  11. The Greeting Behavior of Fragile X Males.

    ERIC Educational Resources Information Center

    Wolff, Peter H.; And Others

    1989-01-01

    The study found that mentally retarded males (N=18) above 12 years of age with a fragile site on the X chromosome exhibited a highly idiosyncratic stereotypic form of gaze avoidance during greeting ceremonies. Results suggest this aberrant greeting behavior may be uniquely associated with this syndrome of mental retardation. (Author/DB)

  12. X chromosome gain in male breast cancer.

    PubMed

    Di Oto, Enrico; Monti, Valentina; Cucchi, Maria C; Masetti, Riccardo; Varga, Zsuzsanna; Foschini, Maria P

    2015-12-01

    Male breast cancer (MBC) is an uncommon disease whose molecular profile is not well known. X chromosome gain has been described as a marker of aggressive behavior in female breast cancer. The aim of this study is to investigate the role of the X chromosome in male breast cancer. Twenty cases of male breast invasive ductal carcinoma were retrieved and compared with 10 cases of gynecomastia. Cases were tested by fluorescence in situ hybridization to assess a cytogenetic profile for the X chromosome. The X chromosome status was compared with histopathologic features and stage at presentation. All MBC cases harbored an X chromosome gain (100%) in a variable percentage of neoplastic cells, ranging from 31% to 85% (mean, 59%). On the contrary, all cases of gynecomastia showed wild X chromosome asset. The patients' age at surgery and tumor grading showed a statistically significant correlation (P = .0188-.04), with the percentages of neoplastic cells showing an X chromosome gain. These data suggest that this X chromosome gain plays a role in the neoplastic transformation of male breast epithelial cells.

  13. 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

  14. Male Influences on Fertility: Needs for Research.

    ERIC Educational Resources Information Center

    Marciano, Teresa Donati

    1979-01-01

    A study comparing the processes of arriving at fertility decisions in marriage shows that the husband's preference for children or for childlessness controls more often than the wife's preference in either case. Using two childless samples and one sample with children, the strong effect of male preference was found. (Author)

  15. Field performance of engineered male mosquitoes.

    PubMed

    Harris, Angela F; Nimmo, Derric; McKemey, Andrew R; Kelly, Nick; Scaife, Sarah; Donnelly, Christl A; Beech, Camilla; Petrie, William D; Alphey, Luke

    2011-10-30

    Dengue is the most medically important arthropod-borne viral disease, with 50-100 million cases reported annually worldwide. As no licensed vaccine or dedicated therapy exists for dengue, the most promising strategies to control the disease involve targeting the predominant mosquito vector, Aedes aegypti. However, the current methods to do this are inadequate. Various approaches involving genetically engineered mosquitoes have been proposed, including the release of transgenic sterile males. However, the ability of laboratory-reared, engineered male mosquitoes to effectively compete with wild males in terms of finding and mating with wild females, which is critical to the success of these strategies, has remained untested. We report data from the first open-field trial involving a strain of engineered mosquito. We demonstrated that genetically modified male mosquitoes, released across 10 hectares for a 4-week period, mated successfully with wild females and fertilized their eggs. These findings suggest the feasibility of this technology to control dengue by suppressing field populations of A. aegypti.

  16. 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…

  17. Sex Bias in Traditionally Male Occupational Programs.

    ERIC Educational Resources Information Center

    Bakshis, Robert; Godshalk, James

    To evaluate potential sources of female sex bias and sex stereotyping within traditionally male occupational programs at the College of DuPage, programs with low female enrollment were selected for study: air conditioning and refrigeration, architectural drafting, auto service, building construction, criminal justice, electronics, fire science,…

  18. Selenium status of idiopathic infertile Nigerian males.

    PubMed

    Akinloye, Oluyemi; Arowojolu, A O; Shittu, O B; Adejuwon, C A; Osotimehin, Babatunde

    2005-04-01

    Selenium concentration in the sera and seminal plasma of 60 infertile males (40 oligospermia and 20 azoospermia) and 40 males with proven evidence of fertility (normospermia; control group) were estimated using atomic absorption spectrophotometry. Results were correlated with spermatogram and hormonal levels in order to determine their relationship and significance in male infertility. The mean serum concentrations of selenium was found to be significantly increased in oligospermic compared to azoospermic subjects and controls (p < 0.01), whereas the seminal plasma level was significantly higher in azoospermic compared to oligospermic subjects and controls (p < 0.001). Thus, the ratio of serum selenium to seminal plasma selenium was 1: 1 in controls, 4: 1 in oligospermia, and 1: 2 in azoospermic subject.A significant inverse correlation was observed between serum selenium level and sperm count (p < 0.01). Similarly, seminal plasma selenium correlated with spermatozoa motility, viability, and morphology. Serum selenium level shows positive correlation with the serum testosterone level (p < 0.01). In conclusion, there appears to be a physiological balance in the distribution of selenium in serum and seminal plasma compartment of control males. A disturbance in this balance has a significant influence on spermatogenesis. Selenium appears to have a positive influence on Leydig cells, thus influencing the secretion of testosterone.

  19. 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)

  20. School-Related Characteristics of Male Juveniles.

    ERIC Educational Resources Information Center

    Sapp, Gary L.; Abbott, Gypsy A.

    School-related characteristics of 256 male juveniles under the jurisdiction of a Family Court system were examined by perusing court records and conducting individual interviews with the juveniles. Results indicated that most juveniles last attended eighth grade, more than 81% had failed at least once, and more than half had fought frequently at…

  1. Sport and the Sexually Abused Male Child

    ERIC Educational Resources Information Center

    Hartill, Mike

    2005-01-01

    Through feminist research in the study of sport, the issue of child sexual abuse has been driven onto the agenda of sports organisations, resulting in considerable practical reform (Brackenridge, 2001). However, the flip-side to this development is that the experience of sexually abused males has been largely ignored. In 1990, Struve claimed, "a…

  2. 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…

  3. Melatonin hormone profile in infertile males.

    PubMed

    Awad, Hosni; Halawa, Fawzy; Mostafa, Taymour; Atta, Hazem

    2006-06-01

    Melatonin is a hormone produced by the pineal gland. There is much controversy about its relationship to the male reproductive process. In this study, seminal plasma as well as the serum melatonin levels were studied in different infertile male groups and were correlated with their semen parameters and hormonal levels. One hundred twenty male cases subdivided into six equal groups were consecutively included; fertile normozoospermic men, oligoasthenozoospermia (OA), OA with leucocytospermia, OA with varicocele, non-obstructive azoospermia (NOA) with high serum follicle stimulating hormone (FSH) and NOA with normal FSH. Semen analysis, estimation of melatonin, FSH, testosterone (T) and prolactin (PRL) hormone was carried out. Mean level of serum melatonin was higher than its corresponding seminal concentrations in all investigated groups with a positive correlation between their levels (r = 0.532, p = 0.01). Serum and seminal plasma melatonin levels in all infertile groups were reduced significantly compared with their levels in the fertile group. The lowest concentrations were in OA with leucocytospermia group. Melatonin in both serum and semen demonstrated significant correlation with sperm motility (r = 607, 0.623 respectively, p = 0.01). Serum melatonin correlated positively with serum PRL (r = 0.611, p = 0.01). It may be concluded that melatonin may be involved in the modulation of reproductive neuroendocrine axis in male infertility. Also, low levels of melatonin in semen were observed in infertile groups having reduced sperm motility, leucocytospermia, varicocele and NOA.

  4. African-American Males: Education or Incarceration.

    ERIC Educational Resources Information Center

    Green, Robert L.

    This paper analyzes the relationship between levels of educational attainment and outcomes for African American males, in particular the likelihood of conflict with the criminal justice system. The analysis begins with a look at society's belief system and political and economic forces, and argues that these have combined to promote failure among…

  5. Sexually transmitted infections: impact on male fertility.

    PubMed

    Ochsendorf, F R

    2008-04-01

    The impact of sexually transmitted diseases (STD) on male fertility is strongly dependent on the local prevalence of the STDs. In Western countries STD-infections are of minor relevance. In other regions, i.e. Africa or South East Asia, the situation appears to be different. Acute urethritis could not be associated with male infertility. Chronic infections (gonorrhoea) can cause urethral strictures and epididymo-orchitis. Chlamydia trachomatis and Neisseria gonorrhoea can be transmitted to the female partner and cause pelvic inflammatory disease with tubal obstruction. Ureaplasma urealyticum may impair spermatozoa (motility, DNA condensation). Trichomonas vaginalis has, if any, only minor influence on male fertility. The relevance of viral infections (HPV, HSV) for male infertility is not resolved. Any STD increases the chances of transmission of the human immunodeficiency virus (HIV). The HIV infection is associated with infectious semen and the risk of virus transmission. Semen quality deteriorates with the progression of immunodeficiency. Special counselling of serodiscordant couples is needed. STDs should be treated early and adequately to prevent late sequelae for both men and women.

  6. Subtyping Male Perpetrators of Intimate Partner Violence

    ERIC Educational Resources Information Center

    Fowler, Katherine A.; Westen, Drew

    2011-01-01

    Domestic violence is a serious problem with far-reaching consequences. This study applies a new methodology to derive subtypes of male perpetrators of intimate partner violence. As part of a larger National Institute of Mental Health (NIMH)-funded study, a national sample of randomly selected psychologists and psychiatrists describe 188 adult male…

  7. 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.

  8. Health Needs and Concerns of Male Adolescents.

    ERIC Educational Resources Information Center

    Pinch, Winifred J.; And Others

    1986-01-01

    Examined male college students' (N=159) concerns in the areas of alcohol and other drug use, automobile safety, weight and dieting, smoking, sexuality, coping and stress, and selection and utilization of health care services. Identified major problems with alcohol use, automobile safety, weight control, stress, and sexuality. Also identified…

  9. City's Black Males Stay in School

    ERIC Educational Resources Information Center

    Aarons, Dakarai I.

    2010-01-01

    School leaders in Baltimore have mounted an offensive over the past three years to keep more students in school and on track. Last month, news came that the effort has produced a welcome dividend: Black male students are driving a marked increase in the district's graduation rate and a decrease in its dropout rate, and showing improvement at a…

  10. 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…

  11. 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...

  12. Career Patterns of Distinguished Male Social Scientists.

    ERIC Educational Resources Information Center

    Blackburn, Robert T.; Havighurst, Robert J.

    Seventy-four male eminent social scientists provided career stage data by which adult development theory was tested. All were born between 1893 and 1903 and met the criteria of a distinguished (and for several still active) scholarly career. The subjects were separated into four groups on the basis of their degree of productivity as of age 60.…

  13. A new orally active male antifertility agent.

    PubMed

    Coppola, J A; Saldarini, R J

    1974-05-01

    CL 88,236 (1-1-amino-3-chloro-2-propanol HC1) was tested orally for antifertility in male rats, mice and hamsters. It was given orally in propylene glycol either daily for 14 days with mating on Days 7-14, (or for 7 days with mating on Days 2, 4, and 6, or for 7 days every other week for 3 weeks in withdrawal tests. In male rats, 5 mg per kg for 14 days reduced number of pregnant females 50%, and at 10-80 mg per kg males were completely sterile. Libido, coitus, and ejaculation were normal, but fragmented sperm, spermatogenic arrest, and granuloma-like epididymal lesions appeared at 40 and 80 mg per kg. Serial matings showed that sterility developed within 6 days and lasted for 1 week after withdrawal. Sterility was maintained by treating rats with CL 88,236 on alternating weeks. Male mice and hamsters were sterilized by 300 mg per kg per day for 14 days, without toxicity. Sterility was apparently mediated by affecting epididymal and vas sperm stores.

  14. Sex chromosome inactivation in the male.

    PubMed

    Yan, Wei; McCarrey, John R

    2009-10-01

    Mammalian females have two X chromosomes, while males have only one X plus a Y chromosome. In order to balance X-linked gene dosage between the sexes, one X chromosome undergoes inactivation during development of female embryos. This process has been termed X-chromosome inactivation (XCI). Inactivation of the single X chromosome also occurs in the male, but is transient and is confined to the late stages of first meiotic prophase during spermatogenesis. This phenomenon has been termed meiotic sex chromosome inactivation (MSCI). A substantial portion ( approximately 15-25%) of X-linked mRNA-encoding genes escapes XCI in female somatic cells. While no mRNA genes are known to escape MSCI in males, approximately 80% of X-linked miRNA genes have been shown to escape this process. Recent results have led to the proposal that the RNA interference mechanism may be involved in regulating XCI in female cells. We suggest that some MSCI-escaping miRNAs may play a similar role in regulating MSCI in male germ cells.

  15. Childhood of Males with the XYY Syndrome

    ERIC Educational Resources Information Center

    Nielsen, Johannes; And Others

    1973-01-01

    Investigated to determine specific intelligence, personality characteristics, and behavioral patterns of boys with the XYY syndrome (a rare pattern of sex chromosome imbalance) were the childhood and adolescence of 20 males, 6- to 58-years of age at time of diagnosis. (Author/MC)

  16. 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…

  17. 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…

  18. 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

  19. Male gender identity and sexual behaviour.

    PubMed

    Chused, J F

    1999-12-01

    One consequence of a heightened interest in intersubjectivity in the current psychoanalytic literature has been a relative neglect of the examination of unconscious fantasies. Presenting material from the analysis of three males, each of whom, in childhood and/or adolescence, hid his penis between his legs and looked at himself in a mirror naked, the author demonstrates the importance of attending to both unconscious fantasies and their manifestations within the interactive field of analysis. The first patient is a young child with a gender identity disorder, whose wish to be like his mother was a response to the emotional loss of her during early childhood. The second patient is an adolescent, whose behaviour in front of a mirror was a manifestation of his desire to possess his mother and be her, to humiliate and sadistically control her, and at the same time, to experience the masochistic sexual gratification of being a seemingly helpless victim. The third patient, a 48-year-old male, came to analysis filled with suicidal impulses and self-hatred related to homosexual impulses. His repeated examination of himself in a mirror, with penis hidden, reflected severe castration anxiety, related to an ambivalent relationship with an angry mother and a longing for attention from an unavailable father. The article closes with a description of the similarities and differences in the dynamics of these three males as well as a discussion of the meaning of similar behaviour in other males seen in consultation.

  20. 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…

  1. 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

  2. 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)

  3. 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…

  4. 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…

  5. 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…

  6. Suspect osteogenesis imperfecta in a male kitten.

    PubMed

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

    2007-03-01

    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.

  7. The Male Midlife Crisis and Career Change.

    ERIC Educational Resources Information Center

    DeBlassie, Richard; Sagal, Karen

    1981-01-01

    Mental, physical, emotional, and spiritual aspects of midlife males are frequently disturbed and have a definite impact on job satisfaction. Three major tasks to be worked on during this time are described: (1) terminating early adulthood; (2) dealing with polarities; and (3) initiating middle adulthood. (Author)

  8. Male Midlife Crisis and Career Change.

    ERIC Educational Resources Information Center

    Kaminski-daRoza, Victoria

    1984-01-01

    The author examines various aspects of male midlife crisis and its effects on the man's career, including the following: What are the implications for an organization, if behavioral changes or dissatisfaction with past patterns extends into the employee's job and leads this same individual to become a dissatisfied employee, to consider a career…

  9. 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…

  10. Male sterility and hybrid seed production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual reproduction in angiosperms is a complex process that includes a portion of the vegetative generation and all of the sexual generation. Coordination of both female and male reproduction ontogenies must occur. An abnormality anywhere in this process may lead to sterility. Genetic (nuclear) and...

  11. Risk factors for male breast cancer.

    PubMed

    Mabuchi, K; Bross, D S; Kessler, I I

    1985-02-01

    To investigate risk factors in male breast cancer, a case-control study of 52 histologically diagnosed cases and 52 controls--matched for age, race, marital status, and hospital--was conducted in 5 U.S. metropolitan areas. Cases were significantly more likely to be Jewish than were the controls, supporting earlier suggestions of an increased risk in Jewish males. A significant association of male breast cancer with mumps infections at age 20 years or older, along with the possible association with antecedent testicular injury and the excess frequency of mumps orchitis among cases, suggests that testicular factors may be important in the development of breast cancer among males. An increased frequency of breast cancer among persons who have worked in blast furnaces, steel works, and rolling mills is of interest because of the possible testicular effect of high environmental temperatures. The observed association between breast cancer and a prior history of swollen breast is difficult to interpret because of potential recall bias, and a possible relationship with military service needs further confirmation.

  12. Epidemiologic methods for investigating male fecundity

    PubMed Central

    Olsen, Jørn; Ramlau-Hansen, Cecilia Høst

    2014-01-01

    Fertility is a couple concept that has been measured since the beginning of demography, and male fecundity (his biological capacity to reproduce) is a component of the fertility rate. Unfortunately, we have no way of measuring the male component directly, although several indirect markers can be used. Population registers can be used to monitor the proportion of childless couples, couples who receive donor semen, trends in dizygotic twinning, and infertility diagnoses. Studies using time-to-pregnancy (TTP) may identify couple subfecundity, and TTP data will correlate with sperm quality and quantity as well as sexual activity and a number of other conditions. Having exposure data available for couples with a fecund female partner would make TTP studies of interest in identifying exposures that may affect male fecundity. Biological indicators such as sperm quality and quantity isolate the male component of fertility, and semen data therefore remain an important source of information for research. Unfortunately, often over half of those invited to provide a sperm sample will refuse, and the study is then subject to a selection that may introduce bias. Because the most important time windows for exposures that impair semen production could be early fetal life, puberty, and the time of ejaculation; longitudinal data over decades of time are required. The ongoing monitoring of semen quality and quantity should continue, and surveys monitoring fertility and waiting TTP should also be designed. PMID:24369129

  13. Genomic Landscape of Developing Male Germ Cells

    PubMed Central

    Lee, Tin-Lap; Pang, Alan Lap-Yin; Rennert, Owen M.; Chan, Wai-Yee

    2010-01-01

    Spermatogenesis is a highly orchestrated developmental process by which spermatogonia develop into mature spermatozoa. This process involves many testis- or male germ cell-specific gene products whose expressions are strictly regulated. In the past decade the advent of high-throughput gene expression analytical techniques has made functional genomic studies of this process, particularly in model animals such as mice and rats, feasible and practical. These studies have just begun to reveal the complexity of the genomic landscape of the developing male germ cells. Over 50% of the mouse and rat genome are expressed during testicular development. Among transcripts present in germ cells, 40% – 60% are uncharacterized. A number of genes, and consequently their associated biological pathways, are differentially expressed at different stages of spermatogenesis. Developing male germ cells present a rich repertoire of genetic processes. Tissue-specific as well as spermatogenesis stage-specific alternative splicing of genes exemplifies the complexity of genome expression. In addition to this layer of control, discoveries of abundant presence of antisense transcripts, expressed psuedogenes, non-coding RNAs (ncRNA) including long ncRNAs, microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), and retrogenes all point to the presence of multiple layers of expression and functional regulation in male germ cells. It is anticipated that application of systems biology approaches will further our understanding of the regulatory mechanism of spermatogenesis.† PMID:19306351

  14. Anabolic steroids abuse and male infertility.

    PubMed

    El Osta, Rabih; Almont, Thierry; Diligent, Catherine; Hubert, Nicolas; Eschwège, Pascal; Hubert, Jacques

    2016-01-01

    For several decades, testosterone and its synthetic derivatives have been used with anabolic and androgenic purposes. These substances were first restricted to professional bodybuilders, but become more and more popular among recreational athletes. Up to date, 3,000,000 anabolic-androgenic steroids (AAS) users have been reported in the United States with an increasing prevalence, making AAS consumption a major public health growing concern. Infertility is defined by the WHO as the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse and a male factor is present in up to 50 % of all infertile couples. Several conditions may be related to male infertility. Substance abuse, including AAS, is commonly associated to transient or persistent impairment on male reproductive function, through different pathways. Herein, a brief overview on AAS is offered. Steroids biochemistry, patterns of use, physiological and clinical issues are enlightened. A further review about fertility outcomes among male AAS abusers is also presented, including the classic reports on transient anabolic steroid-induced hypogonadism (ASIH), and the more recent experimental reports on structural and genetic sperm damage.

  15. 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…

  16. 47,XXX chromosome constitution in a male.

    PubMed

    Bigozzi, U; Simoni, G; Montali, E; Dalpra, L; Rossella, F; Piazzini, M; Borghi, A

    1980-02-01

    An 18-year-old boy with a male phenotype was examined because of testicular hypoplasia. Chromosome analysis using Q- and R-banding techniques and BUdR treatment showed a 47,XXX karotype, in both lymphocytes and fibroblasts. Cytogenetic problems raised by this case are discussed in relation to data from previous published reports.

  17. 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…

  18. The visual system of male scale insects.

    PubMed

    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.

  19. 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.

  20. Explosive neuromuscular performance of males versus females.

    PubMed

    Hannah, Ricci; Minshull, Claire; Buckthorpe, Matthew W; Folland, Jonathan P

    2012-05-01

    The purpose of the study was to investigate sex-related differences in explosive muscular force production, as measured by electromechanical delay (EMD) and rate of force development (RFD), and to examine the physiological mechanisms responsible for any differences. The neuromuscular performance of untrained males (n = 20) and females (n = 20) was assessed during a series of isometric knee extension contractions; explosive and maximal voluntary efforts, as well as supramaximal evoked twitches and octets (eight pulses at 300 Hz). Evoked and voluntary EMD were determined from twitch and explosive contractions. The RFD was recorded over consecutive 50 ms time windows from force onset during evoked and explosive contractions, and normalized to maximal strength. Neuromuscular activity during explosive voluntary contractions was measured with EMG of the superficial knee extensors normalized to maximal M-wave. Muscle size (thickness) and muscle-tendon unit (MTU) stiffness were assessed using ultrasonic images of the vastus lateralis at rest and during ramped contractions. Males and females had similar evoked and voluntary EMD. Males were 33% stronger (P < 0.001) and their absolute RFD was 26-56% greater (all time points P < 0.05) compared with females. Muscle size (P < 0.001) and absolute MTU stiffness were also greater for males (P < 0.05). However, normalized RFD was similar for both sexes during the first 150 ms of the explosive voluntary contractions (P > 0.05). This was consistent with the similar normalized twitch and octet RFD, MTU stiffness and agonist EMG (all P > 0.05). When differences in maximal strength were accounted for, the evoked capacity of the knee extensors for explosive force production and the ability to utilize that capacity during explosive voluntary contractions was similar for males and females.

  1. Infertility in male aquatic invertebrates: a review.

    PubMed

    Lewis, Ceri; Ford, Alex T

    2012-09-15

    As a result of endocrine disruptor studies, there are numerous examples of male related reproductive abnormalities observed in vertebrates. Contrastingly, within the invertebrates there have been considerably less examples both from laboratory and field investigations. This has in part been due to a focus of female related endpoints, inadequate biomarkers and the low number of studies. Whether contaminant induced male infertility is an issue within aquatic invertebrates and their wider communities therefore remains largely unknown and represents a key knowledge gap in our understanding of pollutant impacts in aquatic wildlife. This paper reviews the current knowledge regarding pollutants impacting male infertility across several aquatic invertebrate phyla; which biomarkers are currently being used and where the science needs to be expanded. The limited studies conducted so far have revealed reductions in sperm numbers, examples of poor fertilisation success, DNA damage to spermatozoa and inhibition of sperm motility that can be induced by a range of environmental contaminants. This limited data is mainly comprised from laboratory studies with only a few studies of sperm toxicity in natural populations. Clearly, there is a need for further studies in this area, to include both laboratory and field studies from clean and reference sites, with a focus on broadcast spawners and those with direct fertilisation. Biomarkers developed for measuring sperm quantity and quality in vertebrates are easily transferable to invertebrates but require optimisation for particular species. We discuss how sperm tracking and techniques for measuring DNA strand breaks and sperm viability have been successfully transferred from human infertility clinics to aquatic invertebrate ecotoxicology. Linking sperm toxicity and male infertility effects to higher level impacts on the reproductive biology and dynamics of populations requires a much greater understanding of fertilisation dynamics and

  2. Development of male-fertility-regulating agents.

    PubMed

    Ray, S; Verma, P; Kumar, A

    1991-09-01

    Steroidal, nonsteroidal, plant-derived, gonadotropin-related and immunological agents investigated for control of male fertility are reviewed with brief descriptions of their effects, and illustrations of their structures. The physiology of the male reproductive system is presented as an introduction: an ideal male antifertility agent would inhibit spermatogenesis at the level of the Sertoli cells, without affecting endogenous androgen production by Leydig cells, needed for libido and potency. Androgens down-regulate their own production at physiological levels, but few long-acting orally active derivatives are available. Anti-androgens with mixed androgen and progestin activity, combined with a pure androgen are potentially useful. Androgen-progestin combinations are being tested by WHO as implants. Dozens of miscellaneous nonsteroidal compounds have been discovered serendipitously to have antifertility activity in men or male animals, including alkylating agents antimetabolites, antibiotics, sulfa derivatives, fungicides, trichomonocides, amebicides, alpha blockers, antimalarials, coumarins, and carbohydrate derivatives. Various plant alkaloids have been screened. Those of Hibiscus, Vitex and Plumbago species, as well as Tripterygium wilfordii glycosides, which are being evaluated in combination with gossypol, are mentioned here. Gossypol has been thoroughly tested in China, but rejected because of its side effects, particularly hypokalemic paralysis, its low therapeutic index, and uncertain recovery of fertility. Gonadotropin-releasing hormone (GnRH) agonists and antagonists are being researched in combination with androgens with some success. The GnRH antagonists to date have low activity , or cause histamine-related side effects at higher doses; the androgens require a new route such as a long-acting implant to overcome the need for daily injections. Immunological contraception for males has not progressed beyond the research stage.

  3. Ultrasonic Vocalizations of Male Mice Differ among Species and Females Show Assortative Preferences for Male Calls

    PubMed Central

    Musolf, Kerstin; Meindl, Stefanie; Larsen, Angela L.; Kalcounis-Rueppell, Matina C.; Penn, Dustin J.

    2015-01-01

    Male house mice (Mus musculus) emit ultrasonic vocalizations (USVs) during courtship, which attract females, and we aimed to test whether females use these vocalizations for species or subspecies recognition of potential mates. We recorded courtship USVs of males from different Mus species, Mus musculus subspecies, and populations (F1 offspring of wild-caught Mus musculus musculus, Mus musculus domesticus (and F1 hybrid crosses), and Mus spicilegus), and we conducted playback experiments to measure female preferences for male USVs. Male vocalizations contained at least seven distinct syllable types, whose frequency of occurrence varied among species, subspecies, and populations. Detailed analyses of multiple common syllable types indicated that Mus musculus and Mus spicilegus could be discriminated based on spectral and temporal characteristics of their vocalizations, and populations of Mus musculus were also distinctive regardless of the classification model used. Females were able to discriminate USVs from different species, and showed assortative preferences for conspecific males. We found no evidence that females discriminate USVs of males from a different subspecies or separate populations of the same species, even though our spectral analyses identified acoustic features that differ between species, subspecies, and populations of the same species. Our results provide the first comparison of USVs between Mus species or between Mus musculus subspecies, and the first evidence that male USVs potentially facilitate species recognition. PMID:26309246

  4. The Drosophila over compensating males gene genetically inhibits dosage compensation in males.

    PubMed

    Lim, Chiat Koo; Kelley, Richard L

    2013-01-01

    Male Drosophila are monosomic for the X chromosome, but survive due to dosage compensation. They use the Male Specific Lethal (MSL) complex composed of noncoding roX RNA and histone modifying enzymes to hypertranscribe most genes along the X ∼1.6-1.8 fold relative to each female allele. It is not known how the MSL complex achieves this precise adjustment to a large and diverse set of target genes. We carried out a genetic screen searching for novel factors that regulate dosage compensation in flies. This strategy generated thirty alleles in a previously uncharacterized gene, over compensating males (ocm) that antagonizes some aspect of MSL activity. The mutations were initially recovered because they derepressed an MSL-dependent eye color reporter. Null ocm mutations are lethal to both sexes early in development revealing an essential function. Combinations of hypomorphic ocm alleles display a male specific lethality similar to mutations in the classic msl genes, but ocm males die due to excessive, rather than lack of dosage compensation. Males that die due to very low MSL activity can be partially rescued by ocm mutations. Likewise, males that would die from ocm mutations can be rescued by reducing the dose of various msl and roX genes. ocm encodes a large nuclear protein that shares a novel cysteine rich motif with known transcription factors.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24516141

  6. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:26791621

  8. 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.

  9. 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

  10. Early Resumption of Sex following Voluntary Medical Male Circumcision amongst School-Going Males

    PubMed Central

    2016-01-01

    Voluntary medical male circumcision is an integral part of the South African government’s response to the HIV and AIDS epidemic. Following circumcision, it is recommended that patients abstain from sexual activity for six weeks, as sex may increase the risk of female-to-male HIV transmission and prolong the healing period. This paper investigates the resumption of sexual activity during the healing period among a cohort of school-going males in the KwaZulu-Natal province of South Africa. The analysis for this paper compares two groups of sexually active school-going males: the first group reported having sex during the healing period (n = 40) and the second group (n = 98) reported no sex during the healing period (mean age: 17.7, SD: 1.7).The results show that 29% (n = 40) of young males (mean age: 17.9, SD: 1.8) who were previously sexually active, resumed sexual activity during the healing period, had on average two partners and used condoms inconsistently. In addition, those males that engage in sexual activity during the healing period were less inclined to practice safe sex in the future (AOR = 0.055, p = 0.002) than the group of males who reported no sex during the healing period. These findings suggest that a significant proportion of young males may currently and in the future, subject themselves to high levels of risk for contracting HIV post circumcision. Education, as part of a VMMC campaign, must emphasize the high risk of HIV transmission for both the males their partners during the healing period. PMID:27930720

  11. 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…

  12. Proteomic Analysis of Male-Fertility Restoration in CMS Onion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  13. Proteomic analyses of male-fertility restoration in CMS onion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 a proteomics ...

  14. 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.

  15. Unusual Penetrating Injury to the Male Genitalia

    PubMed Central

    2013-01-01

    Various self-inflicted foreign bodies have been removed from the lower urinary tract and external male genitalia. In many cases foreign bodies were inserted or applied for autoerotic reasons which are frequently associated with mental health disorders. Here the author reports an unusual case of self insertion of a 6-cm long metal needle at penoscrotal junction of the erect penis for sexual pleasure. The stitching needle was inserted by a 20-year old male who was too ashamed to admit the motive at first. The caudal end of the needle was palpable at the root of the penis as it was below the urogenital diaphragm. The needle was successfully removed under fluoroscopic guidance with minor surgical exploration and with no complications. PMID:23610711

  16. Genetic prediction of male pattern baldness

    PubMed Central

    Harris, Sarah E.; Ritchie, Stuart J.; Davies, Gail; Gale, Catharine R.; Porteous, David J.; Deary, Ian J.; Marioni, Riccardo E.

    2017-01-01

    Male pattern baldness can have substantial psychosocial effects, and it has been phenotypically linked to adverse health outcomes such as prostate cancer and cardiovascular disease. We explored the genetic architecture of the trait using data from over 52,000 male participants of UK Biobank, aged 40–69 years. We identified over 250 independent genetic loci associated with severe hair loss (P<5x10-8). By splitting the cohort into a discovery sample of 40,000 and target sample of 12,000, we developed a prediction algorithm based entirely on common genetic variants that discriminated (AUC = 0.78, sensitivity = 0.74, specificity = 0.69, PPV = 59%, NPV = 82%) those with no hair loss from those with severe hair loss. The results of this study might help identify those at greatest risk of hair loss, and also potential genetic targets for intervention. PMID:28196072

  17. Occupational mercury exposure and male reproductive health

    SciTech Connect

    Alcser, K.H.; Brix, K.A.; Fine, L.J.; Kallenbach, L.R.; Wolfe, R.A.

    1989-01-01

    This retrospective cohort study was designed to investigate the relationship of male occupational exposure to elemental mercury and several reproductive outcomes. All subjects worked at least 4 months between 1953 and 1966 at a plant that used elemental mercury; 247 white male employees who had the highest exposures were compared to 255 matched nonexposed employees. Individual exposure to mercury was estimated from urinary mercury measurement records. Information on reproductive history and potential confounding variables was obtained through personal interview with each of the employees and with a subset of their wives. No associations were demonstrated between mercury exposure and decreased fertility or increased rates of major malformations or serious childhood illnesses. After controlling for previous miscarriage history, mercury exposure was not a significant risk factor for miscarriage. Because of this study's potential problems with long-term recall, further studies of the effect of mercury on pregnancy outcome are warranted in other populations.

  18. Peritoneal carcinoma in a male patient.

    PubMed

    Jermann, Monika; Vogt, Peter; Pestalozzi, Bernhard C

    2003-01-01

    Peritoneal carcinoma is a rare primary tumor, described in the literature almost exclusively in women. This report describes our clinicopathological findings in a 51-year-old male patient with peritoneal carcinoma and ascites. Pathologic studies included routine histology, immunohistochemistry and electron microscopy on biopsy and autopsy tumor tissue. After chemotherapy, the patient achieved a complete remission twice, lasting for 14 months and 8 months, respectively, and died after 3 years. His clinical course was similar to that of female patients with peritoneal carcinoma or advanced ovarian cancer. Our case confirms the existence of primary peritoneal carcinoma in males. In addition, it shows that this entity responds to the same chemotherapy as used for ovarian cancer and primary peritoneal carcinoma in females.

  19. Sexual functioning of male anabolic steroid abusers.

    PubMed

    Moss, H B; Panzak, G L; Tarter, R E

    1993-02-01

    The effects of anabolic steroid use on male sexual behavior were assessed using a structured clinical interview administered to male body builders currently using steroids, and to two comparison groups (body builders with a past but not current history of steroid use, and a group of "natural" body builders who had never used steroids). Current anabolic steroid users had a significantly higher coital and orgasmic frequency than did comparison athletes. They also reported a significantly higher incidence of erectile difficulties during the past month. Beliefs concerning the sexually stimulating effects of steroids did not correlate with the frequencies of specific sexual behaviors. The data support the contention that anabolic steroids, as androgenic compounds, enhance sexual desire.

  20. Male factors in ART outcome prediction.

    PubMed

    Brincat, Dale; Catania, Sarah; Wismayer, Pierre Schembri; Calleja-Agius, Jean

    2015-03-01

    Paternal influences on reproduction are significant causing about half of the infertile couples to turn to assisted reproductive techniques. Due to the increasing proportion of infertile couples adopting to conceive by in vitro fertilisation (IVF), predicting outcomes is of ever increasing importance. Since pregnancy rates following IVF are still quite low, prognostic information is very helpful in clinical decisions. Although significant research has been done on the maternal influence, male factor infertility is relatively understudied. To date, potential predictors include: method of fertilisation, age, reactive oxygen species, sperm quality parameters and DNA fragmentation. Predictors under investigation which show promising signs, even though there is no clear cut consensus on the predictive value to date include: folate and homocysteine, anti müllerian hormone measurement, environmental factors, body mass index, smoking, male age, stress, some subsets of antisperm antibodies and epigenetic features.

  1. Polyamines in the male reproductive system.

    PubMed

    Calandra, R S; Rulli, S B; Frungieri, M B; Suescun, M O; González-Calvar, S I

    1996-01-01

    This review covers some common aspects of the biosynthesis, interconversion pathways and biochemical functions of polyamines. A particular emphasis is given in experimental models as well as humans, to their presence in the male gonad, prostate gland, seminal vesicles, epididymis and semen. The interaction between hormones (androgens, LH, FSH and PRL) and the main enzymes involved on the polyamine biosynthesis, and the relationship of these compounds on cell growth and differentiation, are also discussed. In this regard, an attention is offered to the potential role of polyamines during early spermatogenesis stages and the use of some enzymes involved in their biosynthesis as sensitive and specific markers of the action of androgens and antiandrogens in the epididymis. Finally, a special issue is addressed to the controversial information documented on polyamines, their oxidation products and the relationship with male fertility.

  2. Relative age effect in Japanese male athletes.

    PubMed

    Nakata, Hiroki; Sakamoto, Kiwako

    2011-10-01

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

  3. 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.

  4. Masculinity and male sexual behaviour in Mozambique.

    PubMed

    Macia, Manuel; Maharaj, Pranitha; Gresh, Ashley

    2011-11-01

    Like many countries in sub-Saharan Africa, Mozambique is facing a severe HIV epidemic. Evidence suggests that male sexual behaviour is one of the driving forces behind the epidemic. Yet, there is limited understanding of how notions of masculinity influence such behaviour in the context of HIV. Using data collected through focus group discussions and in-depth interviews with sexually active men and women, this paper investigates how notions of masculinity influence the risk of HIV infection among men. The study findings suggest that traditional norms of masculinity, the man as the main provider and figure of authority, continue to exert a strong influence on male attitudes and behaviour. Alternative approaches are urgently needed in HIV programming that take into consideration notions of masculinity in order to reduce risky sexual behaviour.

  5. Amantadine stimulates sexual behavior in male rats.

    PubMed

    Ferraz, M R; Santos, R

    1995-08-01

    The effects of amantadine on sexual behavior, penile erection, and seminal emission of male rats was studied. Amantadine significantly decreased latency of mounts in all doses (1.25 to 50 mg/kg), and decreased the number of mounts and intromission latency at the highest doses used. The lowest dose of amantadine significantly increased ejaculation latency and intromission frequency, while higher doses significantly reduced it, which indicates a biphasic response of the drug. Additionally, seminal emission, erections, and genital grooming were significantly induced by amantadine. Amantadine-induced seminal emissions were impaired by spinal cord transection, which suggests the involvement of supraspinal structures in the drug action. Haloperidol and atropine sulphate significantly reduced seminal emissions and penile erections induced by amantadine. These results demonstrate that amantadine stimulates sexual behavior and genital reflexes in male rats and suggest a facilitatory effect of the drug that probably involves different mechanisms of action.

  6. Recent advances in understanding & managing male infertility

    PubMed Central

    Bieniek, Jared M.; Lo, Kirk C.

    2016-01-01

    Male infertility remains a struggle to definitively diagnose and treat with many men labelled as “idiopathic infertility” and eventually requiring assisted reproductive techniques.  Along those lines, research groups are continuing to explore current social and environmental factors, including the obesity epidemic, and their effects on male fertility potential.  Novel biomarkers of natural fertility status and azoospermia etiology have additionally seen recent attention with ACRV1 and TEX101/ECM1 assays either currently or soon to be commercially available.  Despite these advancements, however, medical treatment options have seen little progress.  Though surgical therapies have similarly seen little transformation, groups are exploring the use of testicular sperm for couples with elevated sperm DNA fragmentation and either planned or previously failed IVF/ICSI.  Concerted collaborative efforts will be needed as we move forward to better understand the challenges men face when struggling to conceive. PMID:27990271

  7. [Sclerosing lipogranuloma of the male genitals].

    PubMed

    Dimitrowa, J; Balabanowa, M; Zarnuschanow, P; Scharow, P

    1989-03-15

    We report on a 23-year-old male patient showing sclerosing lipogranuloma of the genitalia and surface ulceration of the penis. Histologic investigation revealed a granuloma of the foreign body type spreading both dermally and subcutaneously and showing cavities of varying sizes, resembling Swiss cheese, which were partly coated with macrophages. Histochemical tests with Sudan Ill, Sudan-black B and OsO4, as well as chromatographic analysis confirmed the presence of a hydrophobic unpolar lipid, such as liquid paraffin.

  8. Male genitoplasty for 46 XX congenital adrenal hyperplasia patients presenting late and reared as males

    PubMed Central

    Sharma, Shilpa; Gupta, Devendra K.

    2012-01-01

    Aim: To evaluate the clinical profile and management of 46 XX Congenital Adrenal Hyperplasia (CAH) patients presenting with severe virilization and assigned a male gender. Materials and Methods: Of 173 children diagnosed with CAH at the Pediatric Intersex Clinic since 1980, seven children with CAH presented late with severe virilization and were reared as males. All of them were assigned the male sex with removal of the female adnexa. Six were treated with male genitoplasty. Appropriate hormonal supplementation was offered after puberty. Results: The mean age at presentation was 14.2 years (7 – 21). Six patients had presented after puberty, only one at seven years of age. Staged male genitoplasty comprising of chordee correction, male urethroplasty, and bilateral testicular prosthesis was performed. The female adnexa (uterus, ovaries, most of the upper vagina, and the fallopian tubes) were removed. The mental makeup was masculine in six and bigender in one. Bilateral mastectomy was performed at puberty in all. Hormonal treatment comprised of glucocorticoids and testosterone. Six patients were comfortable with the outcome of the masculinizing genitoplasty. One had a short-sized phallus. One had repeated attacks of urinary tract infection arising from the retained lower vaginal pouch. Social adjustments were good in all, except in one who had a bigender mental makeup. Conclusion: CAH patients with severe virilization presenting late and reared as males are extremely rare. However, the assigned gender can be retained adequately as males, meeting the socioeconomic compulsions of the society. The results are satisfactory following appropriate surgical procedures and hormonal supplementation. PMID:23226638

  9. XYY male with essential thrombocythemia in childhood.

    PubMed

    Okada, H; Imai, T; Itoh, S; Isobe, K; Onishi, S

    2000-01-01

    We describe a boy with XYY male accompanied with essential thrombocythemia. This is, to our knowledge, the first complete case report of the kind in the pediatric literature. The patient was asymptomatic, but at age 5 his platelet count had increased to 145.5 x 10(4)/microL, and he was diagnosed as having essential thrombocythemia based on the diagnostic criteria of the Polycythemia Vera Study Group. At that time, it was discovered by chromosome analysis of both bone marrow and peripheral blood cells that he was XYY male. At times during the clinical course when his platelet count was 94.1 x 10(4)/microL, his serum thrombopoietin (measured by enzyme-linked immunosorbent assay) was 1.09 fmol/mL, which was normal for his age. Aspirin was administered, and he remained asymptomatic throughout the course. After 2 years, he underwent a spontaneous remission. Because of the small number of reported cases, we have been unable to determine the relation between XYY males and essential thrombocythemia.

  10. Nonparticipatory Stiffness in the Male Perioral Complex

    PubMed Central

    Chu, Shin-Ying; Lee, Jaehoon

    2008-01-01

    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 computer-controlled linear motor servo programmed to impose a series of tensile displacements over a span of approximately 24 mm at the oral angle in 20 healthy young male adults. Perioral electromyograms were simultaneously sampled to confirm nonparticipation or passive muscle state. Perioral stiffness, derived as a quotient from resultant force (ΔF) and oral span (ΔX), was modeled with regression techniques, and subsequently compared to previously reported perioral stiffness data for female adults. Results Multilevel regression analysis revealed a significant quadratic relation between the perioral stiffness and interangle span; however, no significant difference was found between adult males and females. Conclusion These normative measures will have application to future studies designed to objectively assess the effects of pathology (i.e., progressive neuromotor disease, traumatic brain insult) and intervention (pharmacologic, neurosurgical, and reconstructive surgery of the face [i.e., cleft lip, trauma, missile injuries]) on facial animation and speech kinematics. PMID:19717655

  11. Diseases of the male nipple and areola.

    PubMed

    Krause, Walter

    2011-12-01

    The male nipple-areola-complex (NAC) is a residual organ without physiologic functions in the male. It possesses similar hormone sensitivity and sexual sensitivity as the female organ. The location of the NAC on the chest wall with respect to other surface features is relevant for the male appearance. All known disseminated skin diseases may involve the nipple and areola. A number of specific localized diseases have been described in the literature, such as mammillary eczema, demodicidosis, lymphadenosis cutis benigna, nevoid hyperkeratosis, and thelalgia. Special attention is required if nipple discharge is observed. Areolar sebaceous hyperplasia and nearly all kinds of benign cutaneous tumors occur on the nipple and areola. Malignant tumors such as basal cell carcinoma, melanoma, Paget disease and other forms of breast cancer may also be found. In addition, aberrant mammary tissue may occur with a broad clinical spectrum, while absence of the nipple is an unusual observation and occurs in rare syndromes. The association of aberrant mammary tissue with urinary tract malformations has not been confirmed.

  12. Aging, mitochondria and male reproductive function.

    PubMed

    Amaral, Sandra; Ramalho-Santos, João

    2009-12-01

    The rise in life expectancy over the last century, together with higher maternal and paternal ages and have highlighted the issue of reduced fertility with advancing age. Aging of the male reproductive system is incited by multi-factorial changes at molecular, cellular and regulatory levels, and individual characteristics are highly variable, although strongly influenced by lifestyle and environmental factors. Damage accumulated with age leads to progressive deregulation of the hypothalamic-pituitary-gonadal axis and of local auto/paracrine interactions, thereby inducing changes in target organs such as the testis, penis and prostate. Elderly human males produce less testosterone, have fewer motile sperm and a higher incidence of erectile dysfunction and prostate disorders, all of which contribute to lower fertility. Cellular aging can manifest itself at several levels. Aging cells progressively accumulate "waste" products, resulting in a decreased functionally. Changes to mitochondria are among the most remarkable features observed in aging cells and several theories place mitochondria at the hub of cellular events related to aging, namely in terms of the accumulation of oxidative damage to cells and tissues, a process in which these organelles may play a prominent role, although alternative theories have also emerged. Furthermore, mitochondrial energy metabolism is also crucial for male reproductive function and mitochondria may therefore constitute a common link between aging and fertility loss.

  13. Male batterers' alcohol use and gambling behavior.

    PubMed

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

    2012-03-01

    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.

  14. The psychology of male (non) involvement.

    PubMed

    1977-01-01

    The primary reason for male involvement in family planning is that the current approach of focusing all family planning attention on women is not working. Unwanted pregnancy continues to increase despite the advent of the oral contraceptive and the IUD and despite the great amount of money and effort that have been invested in making women better contraceptors. Whether or not a contraceptive is effectively used depends a lot on the attitude of the man. The great majority of the studies conducted on male attitudes toward ocntraception indicates that boys and men are interested in the subject. Despite the discrepancy between what people say and what they actually do, there is a vast population of men who are receptive to education and guidance. If the approach is right, the majority of men are willing to become involved. The men who are resistant to involvement in family planning are a minority, and probably nothing can be done about this group. Although the majority of men are not resistant, they see no reason for involvement. In the last 20 years men have been taught that contraception is none of their business. This teaching has been done by the media, family planning agencies, some feminist writers and by women themselves. Most of the resistance to male involvement comes from family planning agencies rather than from the men. How to get men involved in actually a small issues. If there is a change in thinking in the agencies and a willingness to involve men, many effective ways will be found.

  15. Male issues of the ileal pouch.

    PubMed

    Kani, Haluk T; Shen, Bo

    2015-03-01

    : Restorative proctocolectomy with ileal pouch-anal anastomosis is the standard surgical treatment modality for patients with ulcerative colitis who require colectomy. There are special issues related to male gender. We performed systemic literature review on the topic, incorporating the experience in our specialized Center for Ileal Pouch Disorders, and provide recommendations for the identification and management for the gender-specific issues in male patients with ileal pouches. Chronic pouchitis, particularly ischemic pouchitis, anastomotic leak, and presacral sinus are more common in male patients than their female counterparts. Sexual dysfunction can occur after pouch surgery, particularly in those with pouch failure. Diagnosis and management of benign and malignant prostate diseases can be challenging due to the altered pelvic anatomy from the surgery. Digital rectal examination for prostate cancer screening is not reliable. Transpouch biopsy of prostate may lead to pouch fistula or abscess. Pelvic radiation therapy may have an adverse impact on the pouch function. In conclusion, sexual dysfunction and enlarged prostate can occur in patients with the ileal pouch. The measurement of serum prostate-specific antigen is a preferred method for the screening of prostate cancer. If biopsy of the prostate is needed, the perineal route is recommended. The risk for pouch dysfunction and the benefit for oncologic survival of pelvic radiation for prostate cancer should be carefully balanced.

  16. The evolution of humor from male aggression

    PubMed Central

    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. PMID:22359467

  17. The medicalisation of male menopause in America.

    PubMed

    Watkins, Elizabeth Siegel

    2007-08-01

    The topic of male menopause occupied space on the medical radar screen from the late 1930s through the mid-1950s, then virtually disappeared for the next four decades, until the late 1990s. By contrast, articles on this subject appeared in American popular magazines and newspapers at a consistent, if low-level, rate throughout the same period. This essay describes how the male menopause became medicalised, not by the driving forces of academic researchers and influential clinicians, but instead by a model perpetuated by lay people and medical popularisers. A medicalised conceptualisation of the body and the life-cycle had become widespread by the second half of the twentieth century, as Americans grew accustomed to regarding their lives through the lens of medicine. People came to expect medicine to provide a cure for any ailment; in the wake of the development of the so-called wonder drugs, no affliction seemed beyond medical and pharmaceutical intervention. A medicalised model had also been effectively produced for understanding and treating the menopause in women; a parallel, if not identical, stage in the life-course of men seemed reasonable. This framework, rather than persuasive evidence from the research laboratory or clinic, helped to medicalise male menopause and provided the basis for its eventual pharmaceuticalisation at the end of the twentieth century.

  18. Evolving ideas about the male refractory period.

    PubMed

    Turley, Kenneth R; Rowland, David L

    2013-08-01

    The male refractory period (MRP) continues to be a topic of discussion and debate within the field of sexual medicine. To date explanations rely on central descending (efferent) influences involving specific neurotransmitter systems. Herein we explore the issue of the male refractory period, identifying problems with current explanations, specifying the parameters of an adequate model, and suggesting possible mechanisms mediating this phenomenon. We review the literature regarding existing explanations for the MRP and look to other systems of physiological regulation that might provide a model for the conceptualization of the MRP. Our approach differs from traditional explanations in that it emphasizes the possible roles of various peripheral, rather than central, feedback (afferent) systems that affect peripheral autonomic functioning and response. Yet our approach is consistent with other peripheral regulatory feedback systems controlling autonomic response related to such processes as heart rate, respiration, and gut motility. Although direct empirical research supporting our approach is lacking, sufficient evidence exists to support the idea that such processes are not only possible but likely with respect to the male refractory period. We suggest several lines of research that might provide empirical support for this approach.

  19. Biological markers of male reproductive toxicology

    SciTech Connect

    Ewing, L.L.; Mattison, D.R.

    1987-10-01

    Reproduction is a complex, stepwise series of processes that begins with gametogenesis, continues through gamete interaction, implantation, embryonic development, growth, parturition, and postnatal adaptation, and is completed with the development and sexual maturation of the newly formed organism. These reproductive processes do not take place in a chemically pristine environment, but rather in an environment increasingly contaminated with the products and by-products of the chemical age in which we live. Some environmental pollutants are known to be carcinogenic, mutagenic, or toxic to the reproductive system, but most have not been adequately tested for reproductive toxicity. Just as reproduction is complex, biological mechanisms underlying toxicology are similarly complex and involve absorption, distribution, metabolism (toxification and/or detoxification), excretion, and repair. The synthesis of these sciences into the relatively nascent science of reproductive toxicology includes teratology, pharmacology, epidemiology, and occupational and environmental health. Female reproductive function (especially pregnancy outcome) has historically been the focus of attention, but there is increasing interest in the effects of chemical exposure on male reproductive function. Several reports have documented the physiology, biochemistry, and toxicology of male mammalian reproduction, and evaluated susceptibility of the male to the effects of exogenous chemicals.

  20. Psychosocial factors associated with male sexual difficulties.

    PubMed

    McCabe, Marita P; Connaughton, Catherine

    2014-01-01

    The role of medical conditions, childhood experiences, and psychological and relationship factors in the development and maintenance of male sexual difficulties is not well understood. Using self-report questionnaires, the current study examined how these factors are associated with male sexual difficulties overall, as well as for each of four separate problems (low sexual desire, erectile difficulties, premature ejaculation, delayed ejaculation). The participants for the study were 331 Australian men from the general population, all of whom were in cohabiting heterosexual relationships and had experienced one or more of the aforementioned sexual problems. Data were collected via an online survey between January 2010 and April 2011. The results demonstrated that medical factors as well as current psychological factors (e.g., performance anxiety) were most likely associated with each male sexual difficulty. These findings are in contrast to those obtained with women, where relationship factors are strongly related to female sexual problems. They would suggest that the targets for sex therapy may be different for men and women, with medical problems and performance anxiety being the primary targets for men.

  1. Male body image following acquired brain injury.

    PubMed

    Howes, Hannah; Edwards, Stephen; Benton, David

    2005-02-01

    The purpose of this study was to investigate body image concerns and psycho-emotional health in males with acquired brain injury (ABI). Using a between subjects study of 25 males with ABI and 25 matched controls, variables were analysed using correlations and 2 x 2 analyses of variance (ANOVAs) with head injury and injury type as independent variables. Body image and psycho-emotional health were evaluated using self-report questionnaires. Disability and cognitive impairment were measured using a mixture of self-report, cognitive testing and clinical notes. Results indicated that males with ABI had significantly lower self-esteem and body dissatisfaction on a number of items relating to physical and sexual functioning. There were significant differences in body image between stroke and TBI, but there was no corresponding relationship with psycho-emotional health. These body image differences might be explained by age. The finding that ABI has a negative effect on body image and that this relates to psycho-emotional health should be investigated further, perhaps being included in future rehabilitation strategies.

  2. 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

  3. Competition for Trophies Triggers Male Generosity

    PubMed Central

    Pan, Xiaofei Sophia; Houser, Daniel

    2011-01-01

    Background Cooperation is indispensable in human societies, and much progress has been made towards understanding human pro-social decisions. Formal incentives, such as punishment, are suggested as potential effective approaches despite the fact that punishment can crowd out intrinsic motives for cooperation and detrimentally impact efficiency. At the same time, evolutionary biologists have long recognized that cooperation, especially food sharing, is typically efficiently organized in groups living on wild foods, even absent formal economic incentives. Despite its evident importance, the source of this voluntary compliance remains largely uninformed. Drawing on costly signaling theory, and in light of the widely established competitive nature of males, we hypothesize that unique and displayable rewards (trophies) out of competition may trigger male generosity in competitive social environments. Principal Findings Here, we use a controlled laboratory experiment to show that cooperation is sustained in a generosity competition with trophy rewards, but breaks down in the same environment with equally valuable but non-unique and non-displayable rewards. Further, we find that males' competition for trophies is the driving force behind treatment differences. In contrast, it appears that female competitiveness is not modulated by trophy rewards. Significance Our results suggest new approaches to promoting cooperation in human groups that, unlike punishment mechanisms, do not sacrifice efficiency. This could have important implications in any domain where voluntary compliance matters — including relations between spouses, employers and employees, market transactions, and conformity to legal standards. PMID:21494668

  4. Labile male morphology and intraspecific male polymorphism in the Philotrypesis fig wasps.

    PubMed

    Jousselin, Emmanuelle; van Noort, Simon; Greeff, Jaco M

    2004-12-01

    We investigate the evolution of male morphology in the fig wasps belonging to the genus Philotrypesis (Chalcidoidea, Sycorectinae). We first reconstruct the phylogenetic relationships of Philotrypesis associated with African figs using nuclear and mitochondrial DNA. We then determine male morphotypes in the species included in our phylogeny and show that intraspecific polymorphism is common. Most species present two types of males and some species have up to three types. These morphotypes are believed to represent alternative mating tactics: some males show morphological adaptations to fighting, others are winged dispersers and others are small sneakers. Mapping out these variations onto our phylogeny reveals that the combination of morphs changes randomly along the branches of the tree. Both parsimony and likelihood approaches indicate that there has been at least one transition from dimorphism to trimorphism, several gains and losses of the small morph and two independent acquisitions of the winged morph. Using maximum likelihood analyses of character evolution, we estimate transition rates for each morph and show that the evolution of each type of morph are not correlated and that forward and backward transition rates are not significantly different. Our results altogether suggest that male morphology is evolutionary labile, it responds quickly to selection imposed by the mating environment. This study, also suggests that seemingly complex phenotypes, such as winged males, can evolve several times and can even be recreated after having been lost.

  5. Management of male-factor infertility.

    PubMed

    Tournaye, Herman J; Cohlen, Ben J

    2012-12-01

    For many years, the management of male-factor infertility has been empirical rather than evidence-based. In current clinical practice, assisted reproductive techniques are the most successful methods of alleviating male-factor infertility. To date, it remains unclear what adjuvant actions can be taken to improve the outcome of assisted reproductive techniques for male-factor infertility. Evidence shows that smoking adversely affects sperm quality to some extent, and the genetic make-up of sperm to a greater extent; however, because of the scarcity and heterogeneity of studies, its effect on in-vitro fertilisation outcome remains largely unknown. Although smoking cessation should be part of the assisted reproductive techniques treatment plan, the benefit of antioxidant treatment in either smokers or non-smokers undergoing assisted reproductive techniques is still under scrutiny. Other lifestyle modifications in subfertile men, such as refraining from moderate alcohol and caffeine consumption, are even more controversial. When embarking on assisted reproductive techniques to alleviate male-factor infertility, intrauterine insemination may be considered as a first-line treatment for couples in whom the female partner has a normal fertility status, and at least 0.8 × 10(6) progressively motile spermatozoa are recovered after sperm preparation. If no pregnancy is achieved after three to six cycles of intrauterine insemination, in-vitro fertilisation can be proposed. When too few progressively motile spermatozoa are obtained after sperm processing for in-vitro fertilisation, or when surgically retrieved sperm are to be used, intracytoplasmic sperm injection is preferable. Although the outcome of no other assisted reproductive techniques has been scrutinised so much, and no large-scale 'macro-problems' have yet been observed after intracytoplasmic sperm injection, malformation rates are reported to be higher compared with the general population. Therefore, candidates

  6. Re-feeding food-deprived male meadow voles affects the sperm allocation of their rival males.

    PubMed

    Vaughn, Ashlee A; Delbarco-Trillo, Javier; Ferkin, Michael H

    2012-12-01

    An individual's nutritional status affects the manner in which same- and opposite-sex conspecifics respond to that individual, which may affect their fitness. Male meadow voles, Microtus pennsylvanicus, increase their sperm allocation if they encounter the scent mark of an unfamiliar male that is not nutritionally challenged. If, however, the scent mark comes from a male that has been food deprived for 24 hours, stud male voles do not increase their sperm allocation. Food deprived males may be viewed as being lower quality and a reduced risk of sperm competition by rival males. We hypothesized that stud males in promiscuous mating systems tailor their sperm allocations depending on whether rival males have been food deprived and then re-fed. We predicted that newly re-fed males will be considered a strong risk of sperm competition because of the potentially high fitness and survival costs associated with food deprivation in males, and that they will cause stud males to increase their sperm allocation. Our results, however, showed that the recovery period from 24 hours of food deprivation was a relatively slow process. It took between 96 hours and 336 hours of re-feeding male scent donors that were food deprived for 24 hours to induce stud males to increase their sperm allocation to levels comparable to when scent donors were not food deprived. Stud male voles may be conserving the amount of sperm allocated until the male scent donors have recovered from food deprivation and subsequent re-feeding.

  7. Sexual selection of male parental care in giant water bugs.

    PubMed

    Ohba, Shin-Ya; Okuda, Noboru; Kudo, Shin-Ichi

    2016-05-01

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

  8. Sigma virus and male reproductive success in Drosophila melanogaster

    PubMed Central

    Pattanaik, Swetapadma; Johnson, Laura; Matos, Luis F.; Brusini, Jérémie; Wayne, Marta L.

    2016-01-01

    The risk of disease transmission can affect female mating rate, and thus sexual conflict. Furthermore, the interests of a sexually transmitted organism may align or diverge with those of either sex, potentially making the disease agent a third participant in the sexual arms race. In Drosophila melanogaster, where sexual conflict over female mating rate is well established, we investigated how a common, non-lethal virus (sigma virus) might affect this conflict. We gave uninfected females the opportunity to copulate twice in no-choice trials: either with two uninfected males, or with one male infected with sigma virus followed by an uninfected male. We assessed whether females respond behaviorally to male infection, determined whether male infection affects either female or male reproductive success, and measured offspring infection rates. Male infection status did not influence time to copulation, or time to re-mating. However, male infection did affect male reproductive success: first males sired a significantly greater proportion of offspring, as well as more total offspring, when they were infected with sigma virus. Thus viral infection may provide males an advantage in sperm competition, or, possibly, females may preferentially use infected sperm. We found no clear costs of infection in terms of offspring survival. Viral reproductive success (the number of infected offspring) was strongly correlated with male reproductive success. Further studies are needed to demonstrate whether virus-induced changes in reproductive success affect male and female lifetime fitness, and whether virus-induced changes are under male, female, or viral control. PMID:27616808

  9. Asymmetric learning to avoid heterospecific males in Mesocricetus hamsters.

    PubMed

    delBarco-Trillo, Javier; Johnston, Robert E

    2012-08-01

    If a female mates with a male of a closely related species, her fitness is likely to decline. Consequently, females may develop behavioral mechanisms to avoid mating with heterospecific males. In some species, one such mechanism is for adult females to learn to discriminate against heterospecific males after exposure to such males. We have previously shown that adult, female Syrian hamsters (Mesocricetus auratus) learn to discriminate against male Turkish hamsters (Mesocricetus brandti) after exposure to a single heterospecific male during 8 days across a wire-mesh barrier. Here we repeated that experiment but this time we exposed female Turkish hamsters to a male Syrian hamster for 8 days and then measured sexual and aggressive behaviors towards that heterospecific male and towards a conspecific male. In contrast to female Syrian hamsters, female Turkish hamsters did not differ in their latency to go into lordosis or in any measure of aggression towards either type of male. Female Turkish hamsters spent less time in lordosis with the heterospecific male, but the percentage of trials in which females copulated with conspecific and heterospecific males did not differ. When comparing females from both species that had been exposed to a heterospecific male for 8days, female Syrian hamsters copulated less and were more aggressive towards the heterospecific male compared to the behavior of female Turkish hamsters. We discuss how this asymmetric response between females of the two species may be due to the much larger geographical range of Turkish hamsters compared to Syrian hamsters.

  10. 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.

  11. 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

  12. Age-Dependent Male Mating Investment in Drosophila pseudoobscura

    PubMed Central

    Dhole, Sumit; Pfennig, Karin S.

    2014-01-01

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

  13. Proteomics, oxidative stress and male infertility.

    PubMed

    Agarwal, Ashok; Durairajanayagam, Damayanthi; Halabi, Jacques; Peng, Jason; Vazquez-Levin, Monica

    2014-07-01

    Oxidative stress has been established as one of the main causes of male infertility and has been implicated in many diseases associated with infertile men. It results from high concentrations of free radicals and suppressed antioxidant potential, which may alter protein expression in seminal plasma and/or spermatozoa. In recent years, proteomic analyses have been performed to characterize the protein profiles of seminal ejaculate from men with different clinical conditions, such as high oxidative stress. The aim of the present review is to summarize current findings on proteomic studies performed in men with high oxidative stress compared with those with physiological concentrations of free radicals, to better understand the aetiology of oxidative stress-induced male infertility. Each of these studies has suggested candidate biomarkers of oxidative stress, among them are DJ-1, PIP, lactotransferrin and peroxiredoxin. Changes in protein concentrations in seminal plasma samples with oxidative stress conditions were related to stress responses and to regulatory pathways, while alterations in sperm proteins were mostly associated to metabolic responses (carbohydrate metabolism) and stress responses. Future studies should include assessment of post-translational modifications in the spermatozoa as well as in seminal plasma proteomes of men diagnosed with idiopathic infertility. Oxidative stress, which occurs due to a state of imbalance between free radicals and antioxidants, has been implicated in most cases of male infertility. Cells that are in a state of oxidative stress are more likely to have altered protein expression. The aim of this review is to better understand the causes of oxidative stress-induced male infertility. To achieve this, we assessed proteomic studies performed on the seminal plasma and spermatozoa of men with high levels of oxidative stress due to various clinical conditions and compared them with men who had physiological concentrations of free

  14. Anaerobic characteristics in male children and adolescents.

    PubMed

    Inbar, O; Bar-Or, O

    1986-06-01

    Only sparse information has been published on the effects of growth, development, and maturation on the ability to perform high intensity, short-term "anaerobic" tasks. Cross-sectional studies on Italian, African, British, and American females and males have indicated an age-related progression in the performance of the Margaria step-running test. Children had a distinctly lower mechanical power output than adolescents and young adults, both in absolute terms and when divided by body weight, or by fat-free mass. Data are presented on some 300 10- to 45-yr-old Israeli males who performed the Wingate anaerobic test by cycling or by arm cranking. Both the peak power at any 5-s period and the mean power throughout the test were lowest in the children, whether expressed in absolute power units or corrected for body weight. Performance progressed with age and reached the highest values at the end of the third decade for cycling and at the end of the second decade for arm cranking. This pattern is unlike that described for maximal O2 uptake per kg body weight which, in males, remains virtually unchanged from childhood to young adulthood. In females, maximal O2 uptake per kg is even higher in children than among adolescents or adults. Biochemical correlates of such a low anaerobic performance in children are their lower maximal lactate concentration in muscle and blood, lower rate of anaerobic glycolysis, and lower levels of acidosis at maximal exercise. The mechanisms for the relatively deficient anaerobic characteristics of children are not clear.

  15. Hospital admissions among male drivers in Denmark

    PubMed Central

    Hannerz, H; Tuchsen, F

    2001-01-01

    OBJECTIVES—To facilitate decisions about interventions and to establish baseline values for future evaluation of preventive efforts, the aim of the present study was to elucidate the disease pattern among male professional drivers in Denmark. The study differentiated between drivers of goods vehicles and drivers of passenger transport.
METHODS—Cohorts of all 20-59 year old Danish male professional drivers in the years 1981, 1986, 1991, and 1994 were formed, to calculate age standardised hospital admission ratios (SHRs) and time trends (1981-97) for many diagnostic aggregations.
RESULTS—SHRs for diseases in practically all systems and organs of the body were higher among professional drivers than they were in the male working population at large. Also drivers of passenger transport, compared with drivers of goods vehicles, had significantly high SHRs due to infectious and parasitic diseases, diseases of the circulatory system, and diseases of the respiratory system, and significantly lower rates of injury. For both driver groups, the SHRs for acute myocardial infarction increased with time whereas the SHR for acute gastritis decreased, and for drivers of passenger transport an increasing SHR for chronic obstructive pulmonary disease, was found over time.
CONCLUSION—Drivers of passenger transport and drivers of goods vehicles differ in their disease patterns. The results support the hypothesis that preventive efforts are needed in both groups, but underline that different strategies are required for different categories of drivers.


Keywords: professional drivers; hospital admissions; surveillance system PMID:11245742

  16. Persistent organic pollutants and male reproductive health

    PubMed Central

    Vested, Anne; Giwercman, Aleksander; Bonde, Jens Peter; Toft, Gunnar

    2014-01-01

    Environmental contaminants such as persistent organic pollutants (POPs) are man-made bioaccumulative compounds with long half-lives that are found throughout the world as a result of heavy use in a variety of consumer products during the twentieth century. Wildlife and animal studies have long suggested adverse effects of exposure to these compounds on human reproductive health, which, according to the endocrine disrupter hypothesis, are ascribed to the compounds’ potential to interfere with endocrine signaling, especially when exposure occurs during certain phases of fetal and childhood development. An extensive number of epidemiological studies have addressed the possible effects of exposure to POPs on male reproductive health, but the results are conflicting. Thus far, most studies have focused on investigating exposure and the different reproductive health outcomes during adulthood. Some studies have addressed the potential harmful effects of fetal exposure with respect to malformations at birth and/or reproductive development, whereas only a few studies have been able to evaluate whether intrauterine exposure to POPs has long-term consequences for male reproductive health with measurable effects on semen quality markers and reproductive hormone levels in adulthood. Humans are not exposed to a single compound at a time, but rather, to a variety of different substances with potential divergent hormonal effects. Hence, how to best analyze epidemiological data on combined exposures remains a significant challenge. This review on POPs will focus on current knowledge regarding the potential effects of exposure to POPs during fetal and childhood life and during adulthood on male reproductive health, including a critical revision of the endocrine disruption hypothesis, a comment on pubertal development as part of reproductive development and a comment on how to account for combined exposures in epidemiological research. PMID:24369135

  17. Acute alcohol exposure markedly influences male fertility and fetal outcome in the male rat.

    PubMed

    Cicero, T J; Nock, B; O'Connor, L; Adams, M L; Sewing, B N; Meyer, E R

    1994-01-01

    Although it is recognized that drugs ingested by pregnant females produce marked cognitive and physiological deficits in their offspring, the possibility that paternal exposure to drugs prior to mating may have adverse effects on fertility and fetal outcome has not received much attention. The purpose of the present studies was to examine whether a single, acute exposure to alcohol influences the subsequent ability of adult male rats to mate and produce healthy and viable litters. Our results showed that a relatively large dose of alcohol 24 hours prior to breeding had little effect on the mating behavior of male rats, but there were markedly fewer pregnancies in females mated with alcohol-exposed male rats than in controls. Of equal importance, we found that, even when conception occurred and live births were produced, there were striking differences in fetal outcome. Alcohol-treated males sired many fewer pups than control males and there was a markedly enhanced mortality rate in their offspring. Collectively, these data suggest that acute paternal alcohol administration 24 hours prior to breeding does not affect mating behavior, but results in a greatly diminished fertility rate and fewer and less viable offspring. These studies suggest that paternal alcohol use may be as important as maternal alcohol abuse as a negative variable in pregnancy and fetal outcome.

  18. Socio-demographic factors intensifying male mating competition exacerbate male mortality rates.

    PubMed

    Kruger, Daniel J

    2010-05-07

    Sex differences in mortality rates stem from a complex set of genetic, physiological, psychological, and social causes whose influences and interconnections are best understood in an integrative evolutionary life history framework. Although there are multiple levels of mechanisms contributing to sex based disparities in mortality rates, the intensity of male mating competition in a population may have a crucial role in shaping the level of excess male mortality. The degree of variation and skew in male reproductive success may shape the intensity of male mating competition, leading to riskier behavioral and physiological strategies. This study examines three socio-demographic factors related to variation in human male reproductive success; polygyny, economic inequality, and the population ratio of reproductively viable men to women across nations with available data. The degrees of economic inequality and polygyny explained unique portions in the sex difference in mortality rates, these predictors accounted for 53% of the variance. The population ratio of reproductively viable men to women did not explain any additional variance. These results demonstrate the association between social conditions and health outcomes in modern nations, as well as the power of an evolutionary life history framework for understanding important social issues.

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

    PubMed

    LeBlanc, Gerald A; Medlock, Elizabeth K

    2015-11-01

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

  20. [Problems with male contraception. 1. Physiological foundations, male contraception (mechanical procedures, contraceptives)].

    PubMed

    Schill, W B

    1978-08-03

    The various aspects of male fertility control are elaborated. A discussion of spermatogenesis and fertilization mechanisms lays the groundwork for determining how these processes can be inhibited. Mechanical male contraceptive methods are coitus interruptus and coitus condomatus. Coitus interruptus can cause neurotic disturbances in both partners and has a failure rate of 10-20/100 use-years. The condom has a failure rate of about 7/100 use-years. Vasectomy is the most practicable operative male contraceptive method. Scrotal hematoma, scrotal abcesses, and congestive epididymitis are possible post-operative complications. 2/3 of the men who have vasectomies develop sperm autoantibodies, and some develop sperm granulomas. Spontaneous recanalization occurs in .8% of the cases. The incipience of azoospermia after vasectomy is dependent on the number of ejaculations but is difficult to predict. Castration and increasing the temperature of the gonads are other operative methods of male contraception. Medicamentive methods of male contraception must be safe, effective, fast, and reversible; they must cause no genetic changes, disturbances in libido or potency, or changes in secondary sex characteristics. Medicamental agents can affect spermatogenesis; the maturation of the spermatozoa; transport, motility, or metabolism of the spermatozoa; capacitation of the spermatozoa; or the penetration enzymes. Heavy metal compounds, cytostatic, or antibiotic compounds are unsuitable as spermatogenic inhibitors due to side effects. 5-Thio-D-Glucose may show promise as an antispermatogenic agent.

  1. 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.

  2. Defective pollen wall contributes to male sterility in the male sterile line 1355A of cotton

    PubMed Central

    Wu, Yuanlong; Min, Ling; Wu, Zancheng; Yang, Li; Zhu, Longfu; Yang, Xiyan; Yuan, Daojun; Guo, Xiaoping; Zhang, Xianlong

    2015-01-01

    To understand the mechanisms of male sterility in cotton (Gossypium spp.), combined histological, biochemical and transcription analysis using RNA-Seq was carried out in the anther of the single-gene recessive genic male sterility system of male sterile line 1355A and male fertile line 1355B, which are near-isogenic lines (NILs) differing only in the fertility trait. A total of 2,446 differentially expressed genes were identified between the anthers of 1355AB lines, at three different stages of development. Cluster analysis and functional assignment of differentially expressed genes revealed differences in transcription associated with pollen wall and anther development, including the metabolism of fatty acids, glucose, pectin and cellulose. Histological and biochemical analysis revealed that a major cellular defect in the 1355A was a thicker nexine, consistent with the RNA-seq data, and further gene expression studies implicated differences in fatty acids synthesis and metabolism. This study provides insight into the phenotypic characteristics and gene regulatory network of the genic male sterile line 1355A in upland cotton. PMID:26043720

  3. Medical male circumcision coverage in Rakai, Uganda.

    PubMed

    Kong, Xiangrong; Kigozi, Godfrey; Ssekasanvu, Joseph; Nalugoda, Fred; Nakigozi, Gertrude; Chang, Larry W; Latkin, Carl; Serwadda, David; Wawer, Maria J; Gray, Ronald H

    2017-03-13

    We assessed medical male circumcision (MMC) scale-up in Rakai, Uganda using population-based surveys during 2007-2014. MMC coverage increased from 28.5 to 52.0%. Coverage was initially lower in 15-19-year-olds but increased in 2014, was higher in married men and in trading communities, and lowest in the sexually inactive. Coverage did not vary by self-perceived risk of HIV or HIV serostatus. Increasing generalized coverage suggested that MMC became normative, but coverage falls short of WHO/Joint United Nations Programme on HIV and AIDS (UNAIDS) 80% targets, indicating the need for demand generation.

  4. [The treatment of anorgasmia in males].

    PubMed

    Vogt, H J

    1975-11-01

    Primary anorgasmia is defined as the inability, in spite of nocturnal pollution and complete erection, ever to achieve orgasm either by masturbation or by sexual intercourse. 30 patients with primary anorgasmia were treated with an electro-vibrator, 26 of them with a positive result. The preceding unsuccessful therapeutical attempts with medicaments and psychotherapy allow the conclusion that with primary male anorgasmia time should not be wasted unnecessarily. Instead, a mechanical ipsation-aid should be employed, regardless of the etiology. Simultaneous intensive psychological guidance including instruction about normal sexual behavior is necessary. Some cases of secundary anorgasmia also react favourably to this treatment.

  5. Intelligence, education, and myopia in males.

    PubMed

    Rosner, M; Belkin, M

    1987-11-01

    We conducted a nationwide study of the relationship among refractive error, intelligence scores, and years of schooling in 157,748 males aged 17 to 19 years. We found a strong association of myopia with both intelligence and years of school attendance. The prevalence of myopia was found to be significantly higher in the more intelligent and more educated groups. By fitting models of logistic regressions, we worked out a formula expressing the relationship among the rate of myopia, years of schooling, and intelligence level. We found that years of schooling and intelligence weigh equally in the relationship with myopia.

  6. Mitochondria and cytoplasmic male sterility in plants.

    PubMed

    Hu, Jun; Huang, Wenchao; Huang, Qi; Qin, Xiaojian; Yu, Changchun; Wang, Lili; Li, Shaoqing; Zhu, Renshan; Zhu, Yingguo

    2014-11-01

    Mitochondria are essential organelles in cells not only because they supply over 90% of the cell's energy but also because their dysfunction is associated with disease. Owing to the importance of mitochondria, there are many questions about mitochondria that must be answered. Cytoplasmic male sterility (CMS) is a mysterious natural phenomenon, and the mechanism of the origin of CMS is unknown. Despite successful utilization of CMS and restoration of fertility (Rf) in practice, the underlying mechanisms of these processes remain elusive. This review summarizes the genes involved in CMS and Rf, with a special focus on recent studies reporting the mechanisms of the CMS and Rf pathways, and concludes with potential working models.

  7. Epigenetic regulation in male germ cells.

    PubMed

    Zamudio, Natasha M; Chong, Suyinn; O'Bryan, Moira K

    2008-08-01

    In recent years, it has become increasingly clear that epigenetic regulation of gene expression is critical during spermatogenesis. In this review, the epigenetic regulation and the consequences of its aberrant regulation during mitosis, meiosis and spermiogenesis are described. The current knowledge on epigenetic modifications that occur during male meiosis is discussed, with special attention on events that define meiotic sex chromosome inactivation. Finally, the recent studies focused on transgenerational and paternal effects in mice and humans are discussed. In many cases, these epigenetic effects resulted in impaired fertility and potentially long-ranging affects underlining the importance of research in this area.

  8. Male Sexual Dysfunction and Chronic Kidney Disease

    PubMed Central

    Edey, Matthew M.

    2017-01-01

    Male sexual dysfunction is common in chronic kidney disease (CKD), particularly in end-stage renal disease. Historically, this cause of considerable morbidity has been under-reported and under-recognized. The ideal approach to diagnosis and management remains unclear due to a paucity of good quality data, but an understanding of the pathophysiology is necessary in order to address the burden of this important complication of CKD. This paper will review the endocrine dysfunction that occurs in renal disease, particularly the hypothalamic–pituitary–gonadal axis, discuss the causes of erectile dysfunction, infertility, and altered body image and libido in these patients and suggest appropriate treatment interventions. PMID:28382300

  9. Molecular mechanisms of male germ cell differentiation.

    PubMed

    Hecht, N B

    1998-07-01

    During spermatogenesis, diploid stem cells differentiate, undergo meiosis, and transform into haploid spermatozoa. As this precisely timed series of events proceeds, chromosomal ploidy is reduced and the nucleosomes of the chromatin are replaced by a transcriptionally quiescent protamine-containing nucleus. The premature termination of transcription during the haploid phase of spermatogenesis necessitates an especially prominent role for posttranscriptional regulation in the temporal and spatial expression of many testis-specific proteins and isozymes. In this review article, discussion will focus on novel mechanisms regulating gene expression in mammalian male germ cells from genome to protein.

  10. Male courtship attractiveness and paternity success in Photinus greeni fireflies.

    PubMed

    Demary, Kristian C; Lewis, Sara M

    2007-02-01

    Although female mate choice and male sperm competition have separately attracted much attention, few studies have addressed how precopulatory and postcopulatory episodes of sexual selection might interact to drive the evolution of male traits. In Photinus fireflies, females preferentially respond to males based on their bioluminescent courtship signals, and females gain direct benefits through male nuptial gifts acquired during multiple matings over several nights. We experimentally manipulated matings of P. greeni fireflies to test the hypothesis that postcopulatory paternity success might be biased toward males that are more attractive during courtship interactions. We first measured male courtship attractiveness to individual females using field behavioral assays. Females were then assigned to two double-mating treatments: (1) least attractive second male-females were first mated with their most attractive male, followed by their least attractive male, or (2) most attractive second male-females mated with males in reverse order. Larval offspring produced by each female following these double matings were genotyped using random amplified polymorphic DNA (RAPD) markers, and male paternity was determined. Contrary to prediction, firefly males that were more attractive to females based on their bioluminescent courtship displays subsequently showed significantly lower paternity, reflecting possible male trade-offs or sexual conflict. Differences in male paternity were not related to male body condition, testes or accessory gland mass, or to variation in female spermathecal size. Additionally, this study suggests that changes in phenotypic selection gradients may occur during different reproductive stages. These results indicate that it is crucial for future studies on sexual selection in polyandrous species to integrate both precopulatory and postcopulatory episodes to fully understand the evolution of male traits.

  11. Male-female relatedness and patterns of male reproductive investment in guppies.

    PubMed

    Fitzpatrick, Luisa J; Gasparini, Clelia; Fitzpatrick, John L; Evans, Jonathan P

    2014-05-01

    Inbreeding can cause reductions in fitness, driving the evolution of pre- and postcopulatory inbreeding avoidance mechanisms. There is now considerable evidence for such processes in females, but few studies have focused on males, particularly in the context of postcopulatory inbreeding avoidance. Here, we address this topic by exposing male guppies (Poecilia reticulata) to either full-sibling or unrelated females and determining whether they adjust investment in courtship and ejaculates. Our results revealed that males reduce their courtship but concomitantly exhibit short-term increases in ejaculate quality when paired with siblings. In conjunction with prior work reporting cryptic female preferences for unrelated sperm, our present findings reveal possible sexually antagonistic counter-adaptations that may offset postcopulatory inbreeding avoidance by females.

  12. Male-Male Competition as a Force in Evolutionary Diversification: Evidence in Haplochromine Cichlid Fish

    PubMed Central

    Dijkstra, Peter D.; Groothuis, Ton G. G.

    2011-01-01

    It has been suggested that intrasexual competition can be a source of negative frequency-dependent selection, causing agonistic character displacement and facilitating speciation and coexistence of (sibling) species. In this paper we synthesise the evidence that male-male and female-female competition contributes to cichlid diversification, showing that competition is stronger among same-coloured individuals than those with different colours. We argue that intrasexual selection is more complex because there are several examples where males do not bias aggression towards their own type. In addition, sibling species or colour morphs often show asymmetric dominance relationships. We briefly discuss potential mechanisms that might promote the maintenance of covariance between colour and aggression-related traits even in the face of gene-flow. We close by proposing several avenues for future studies that might shed more light on the role of intrasexual competition in cichlid diversification. PMID:21785710

  13. 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

  14. Male care and life history traits in mammals

    PubMed Central

    West, Hannah E. R.; Capellini, Isabella

    2016-01-01

    Male care has energetic and opportunity costs, and is more likely to evolve when males gain greater certainty of paternity or when future mating opportunities are scarce. However, little is known about the substantial benefits that males may provide to females and offspring. Using phylogenetic comparative methods and a sample of over 500 mammalian species, we show that mammals in which males carry the offspring have shorter lactation periods, which leads to more frequent breeding events. Provisioning the female is associated with larger litters and shorter lactation. Offspring of species with male care have similar weaning mass to those without despite being supported by a shorter lactation period, implying that they grow faster. We propose that males provide an energetic contribution during the most expensive time of female reproduction, lactation, and that different male care behaviours increase female fecundity, which in turn helps males offset the costs of caring. PMID:27299954

  15. Leading Causes of Death in Males United States, 2010

    MedlinePlus

    ... of Women's Health Health Equity Leading Causes of Death in Males United States Recommend on Facebook Tweet ... and previous listings for the leading causes of death in males in the United States. Please note ...

  16. Stranger and acquaintance sexual assault of adult males.

    PubMed

    Stermac, Lana; Del Bove, Giannetta; Addison, Mary

    2004-08-01

    This study examined victim and assault characteristics and the nature and extent of coercion, violence, and physical injuries among adult male victims of sexual assaults. Client records of three groups presenting to a sexual assault care center were included: males assaulted by a stranger (n = 64), males assaulted by an acquaintance (n = 81), and females assaulted by an acquaintance (n = 106). Study results revealed that male victims of sexual assault tended to be young, single men who reported high rates of vulnerabilities such as homelessness and physical, psychiatric, and cognitive disabilities. Male stranger assailant victims were more likely to experience assaults involving weapons and physical violence. Injuries sustained by victims and services delivered at the sexual assault care center were similar for both male and female clients. The results of this study reveal new information about violence in male sexual assaults and the vulnerability of the male victims.

  17. Testosterone replacement therapy in obese males.

    PubMed

    Drewa, Tomasz; Olszewska-Słonina, Dorota; Chlosta, Piotr

    2011-01-01

    Controversy surrounds testosterone replacement therapy in obese ageing due to no generally accepted lower limits of normal testosterone level and high prevalence of hypogonadal symptoms in the ageing male population and the non-specific nature of these symptoms. Late onset hypogonadism is a clinical and biochemical syndrome associated with advancing age, often coexisting with obesity and metabolic syndrome. High fat and carbohydrates (fructose) consumption is responsible for development of obesity and metabolic syndrome which is one of risk factors for hypogonadism in older men. High fructose intake has been shown to cause dyslipidemia and to impair hepatic insulin sensitivity. Obesity and lack of physical activity negatively influence testosterone level. Low testosterone level should be regarded as an effect of obesity, but reverse relationship has not been proved yet. The management of late-onset hypogonadism symptoms has to be treated by a change of a life style and prevented with healthy nutrition and physical activity. The question related to rational indications for testosterone replacement therapy in obese males seems to be still actual.

  18. Sexual Agreements among Gay Male Couples

    PubMed Central

    Hoff, Colleen H.; Beougher, Sean C.

    2009-01-01

    Many gay male couples make agreements about whether or not to permit sex with outside partners, yet little is known about the development and maintenance of these agreements, their impact on relationships, and whether they are an effective HIV prevention strategy. Using semi-structured, qualitative interviews, 39 gay male couples were asked about their sexual agreements and about other relationship dynamics that might affect their agreements. Analysis revealed a wide range of agreement types, all of which are presented along a continuum rather than as discrete categories. For couples with open agreements, most placed rules or conditions limiting when, where, how often, and with whom outside sex was permitted. Although motivations for having agreements varied, HIV prevention did not rank as a primary factor for any couple. Most couples had congruous agreements; however, a small number reported discrepancies which may increase HIV transmission risk. How couples handled breaks in their agreements also varied, depending on what condition was broken, whether it was disclosed, and the partner's reaction. Additional results include differences in agreement type and motivations for having an agreement based on couple serostatus. Overall, agreements benefited couples by providing boundaries for the relationship, supporting a non-heteronormative identity, and fulfilling the sexual needs of the couple. Future prevention efforts involving gay couples must address the range of agreement types and the meanings couples ascribe to them, in addition to tempering safety messages with the relationship issues that are important to and faced by gay couples. PMID:18686027

  19. Odor compound detection in male euglossine bees.

    PubMed

    Schiestl, F P; Roubik, D W

    2003-01-01

    Male euglossine bees collect fragrances from various sources, which they store and use for as yet unknown purposes. They are attracted, often specifically, to single odor compounds and blends thereof. We used gas chromatography with electroantennographic detection (GC-EAD) and electroantennography (EAG) to investigate the response to 8 odor compounds by males of two euglossine species, Euglossa cybelia Moure and Eulaema polychroma (Mocsàry). In E. cybelia, we recorded EAD reactions in response to 1,8-cineole, methyl benzoate, benzyl actetate, methyl salicylate, eugenol, and methyl cinnamate. E. polychroma responded to the same compounds in EAG experiments, while (1s)(-)alpha-pinene and beta-pinene failed to trigger EAD or EAG responses in the bees. Blends of two compounds triggered larger responses than single compounds in EAG experiments with E. polychroma, however, when alpha-pinene was added, reactions decreased. In the light of existing data on the bees' behavior towards these odor compounds, our work indicates that both peripheral and central nervous processes influence the attraction of euglossine bees to odors.

  20. Molecular analysis of cytoplasmic male sterility

    SciTech Connect

    Hanson, M.R.

    1990-01-01

    The ultimate aims of the project are to understand the molecular mechanism of the disruption in pollen development which occurs in cytoplasmic male sterile plants and to understand the control of respiratory energy flow in the higher plant cell. A mitochondrial locus termed S-pcf segregates with sterility and with an alteration in respiration in Petunia. This cloned locus contains three genes, an abnormal fused gene termed pcf, a gene for a subunit of an NADH dehydrogenase complex, and a small ribosomal subunit protein. The pcf gene is comprised of partial sequences of ATPase subunit 9, cytochrome oxidase subunit II, and an unidentified reading frame. Components of the S-Pcf locus will be introduced into the nuclear of a fertile genotype under the control of appropriate regulatory signals, and polypeptide products of introduced genes will be directed to the mitochondrion with a transit peptide. By examining transgenic plants, we can determine what elements of the locus are critical for altered respiration or sterility. Such knowledge could explain how mitochondrial DNA affects pollen development in the large number of plant species which exhibit the agronomically important trait of male sterility. 10 refs., 3 figs.

  1. Cytoplasmic male sterility in Brassicaceae crops.

    PubMed

    Yamagishi, Hiroshi; Bhat, Shripad R

    2014-05-01

    Brassicaceae crops display strong hybrid vigor, and have long been subject to F1 hybrid breeding. Because the most reliable system of F1 seed production is based on cytoplasmic male sterility (CMS), various types of CMS have been developed and adopted in practice to breed Brassicaceae oil seed and vegetable crops. CMS is a maternally inherited trait encoded in the mitochondrial genome, and the male sterile phenotype arises as a result of interaction of a mitochondrial CMS gene and a nuclear fertility restoring (Rf) gene. Therefore, CMS has been intensively investigated for gaining basic insights into molecular aspects of nuclear-mitochondrial genome interactions and for practical applications in plant breeding. Several CMS genes have been identified by molecular genetic studies, including Ogura CMS from Japanese radish, which is the most extensively studied and most widely used. In this review, we discuss Ogura CMS, and other CMS systems, and the causal mitochondrial genes for CMS. Studies on nuclear Rf genes and the cytoplasmic effects of alien cytoplasm on general crop performance are also reviewed. Finally, some of the unresolved questions about CMS are highlighted.

  2. Mouthparts of male Aedes (Stegomyia) mosquitoes.

    PubMed

    Wahid, Isra; Sunahara, Toshihiko; Mogi, Motoyoshi

    2002-06-01

    Mouthparts of adult males of 17 strains of 8 species from the subgenus Stegomyia of the genus Aedes, including 5 strains of Aedes aegypti and 6 strains of Aedes albopictus, were examined. Lengths of maxillae, mandibles, maxillary palpi, and proboscises were measured under light microscopy and their detailed structures were examined by scanning electron microscopy. Lengths were presented as ratios to proboscis lengths. In contrast to previous reports, mandibles were found in all 5 strains of male Ae. aegypti examined. Variations in maxillary and mandibular lengths were significant among strains, even within Ae. aegypti and Ae. albopictus. High variation of these structures among and within species indicates that the average length of these structures in only 1 species may not be a reliable representative of a subgenus, and those of 1 strain may not be reliable for a species. However, their range in length (maxillae 0.13-0.50, mandibles 0.04-0.17 length of the proboscis) may be regarded as a subgeneric attribute. Maxillae and mandibles distinctly shorter than the proboscis, together with their delicate structures and the large coefficient of variation, suggest that they exist only as vestigial structures. A positive correlation was found between lengths of maxillae and those of mandibles, but mandibles are usually shorter than maxillae. The hypopharynx is discernible from the labium wall by its texture and border, and this suggests that it was a free stylet in the past.

  3. 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.

  4. Male infertility: an obstacle to sexuality?

    PubMed

    Bechoua, S; Hamamah, S; Scalici, E

    2016-05-01

    Interactions between infertility and sexuality are numerous and complex. Infertile men may suffer from sexual dysfunction (SD) when undergoing an assisted reproductive technology programme. We undertook a review both in French and English of the available data on male SD when being diagnosed with a fertility problem with a specific focus on azoospermic men. The review was performed over a 30-year time period using PubMed/Medline. The sexual concerns and needs of infertile/sterile men for whom potential parenting can be compromised were evaluated. When diagnosed with infertility, men usually go through a crisis that can have a deleterious effect on their sexuality with sometimes a feeling of sexual inadequacy. Infertile men will feel stigmatized because they are perceived as being deficient in a specific component of their masculinity. Hence, subsequent SD may occur that can impact the couple sexuality and the infertility management. However, little is known on how the announcement of azoospermia may affect male on a sexual and psychological point of view. The present review suggests that a global management through a healthcare network (biologist, andrologist, sexologist and psychologist) is required which will allow to consider infertility and its subsequent sexual disorders as a whole and not as dichotomized issues.

  5. 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

  6. Male hormonal contraception: looking back and moving forward.

    PubMed

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

    2016-01-01

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

  7. 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

  8. 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…

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

    PubMed

    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.

  10. 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…

  11. 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…

  12. Sexual maturation and aging of adult male mealybug (Hemiptera: Pseudococcidae).

    PubMed

    Mendel, Z; Protasov, A; Jasrotia, P; Silva, E B; Zada, A; Franco, J C

    2012-08-01

    The physiological age of adult males of seven mealybug species was measured in relation to the elongation of the male pair of the waxy caudal filaments. These filaments begin to emerge after eclosion and reached their maximum length from 29.4-46.6 h. The studied males were divided into three age groups, expressed as percentages of the total waxy caudal filaments length. Attraction to a sex pheromone source was significantly higher in the oldest male group (maximum filaments growth) compared with youngest one. Only the oldest male group copulated successfully; few of the younger males tested displayed 'courtship' behavior towards conspecific virgin females. The calculated duration of the sexually active phase of the adult male life cycle varied among species ranging from 34.4 to 46.6 h. There were marked variations in the strength of attraction to a pheromone source according to time of day. There was a continuous decrease in sexual activity from morning to evening. Our findings reveal clear maturation periods for adult males of the seven studied species. The long immature phase of the adult male mealybug is probably also related to several physiological processes that are needed to complete male maturation. The most noticeable change is the elongation of the waxy caudal filaments. However, mating may be performed at any time ambient conditions are suitable. Whereas male mealybug flight towards a pheromone source is restricted to a few hours, the male may continue mating activity throughout its sexually active period.

  13. Development of male-sterile lines for breeding hybrid rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is a self-pollinated crop that depends on male-sterility for F1 hybrid seed production. As an alternative to accessing existing male-sterile lines from other hybrid breeding programs, the program in Arkansas has created its own novel male-sterile sources. These were developed out of germplasm...

  14. Low testosterone correlates with delayed development in male orangutans.

    PubMed

    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.

  15. The evolutionary role of males in C. elegans

    PubMed Central

    Chasnov, Jeffrey R.

    2013-01-01

    Although the nematode worm Caenorhabditis elegans reproduces primarily as a self-fertilizing hermaphrodite, males are maintained in natural populations at low frequency. In this commentary, I discuss the evolutionary forces that maintain males and the role males might play in this mating system. PMID:24058855

  16. 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.

  17. 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

  18. Suppression of Pest Lepidoptera by Releasing Partially Sterile Males

    ERIC Educational Resources Information Center

    Knipling. E. F.

    1970-01-01

    Uses population growth models to calculate the theoretical suppression of reproduction achieved by releasing irradiated male moths carrying genetic sterility factors. Shows that releasing partially sterile males should be more effective than releasing fully sterile males. Discusses the costs and advantages of applying this approach to the control…

  19. The Brotherhood: Empowering Adolescent African-American Males toward Excellence

    ERIC Educational Resources Information Center

    Wyatt, Shelby

    2009-01-01

    A review of the literature reveals that African-American males do not achieve at the same academic levels as their White counterparts. This article reports the effectiveness of a school-based male mentoring program established by a professional school counselor in an urban high school that formed a relationship of support for male students…

  20. Graduate Students' Relationships with Their Male and Female Major Professors.

    ERIC Educational Resources Information Center

    Schroeder, Debra S.; Mynatt, Clifford R.

    1999-01-01

    Performed content analysis of interviews of female students with male and female professors and male students with male and female professors for differences related to student/professor gender combination. Quantitative and qualitative analyses for 40 students showed no differences in professional relationships, but it did reveal some…

  1. 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…

  2. 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.…

  3. 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...

  4. Prolactin daily rhythm in suckling male rabbits

    PubMed Central

    Alvarez, Pilar; Cardinali, Daniel; Cano, Pilar; Rebollar, Pilar; Esquifino, Ana

    2005-01-01

    Background This study describes the 24-h changes in plasma prolactin levels, and dopamine (DA), serotonin (5HT), gamma-aminobutyric acid (GABA) and taurine concentration in median eminence and adenohypophysis of newborn male rabbits. Methods Animals were kept under controlled light-dark cycles (LD 16:8, lights on at 08:00 h), housed in individual metal cages, and fed ad libitum with free access to tap water. On day 1 after parturition, litter size was standardized to 8–9 to assure similar lactation conditions during the experiment. Groups of 6–7 suckling male rabbits were killed by decapitation on day 11 of life at six different time points during a 24-h period. Results Plasma prolactin levels changed significantly throughout the day, showing a peak at the beginning of the active phase (at 01:00 h) and a second maximum during the first part of the resting phase (at 13:00 h). Median eminence DA concentration also changed significantly during the day, peaking at the same time intervals as plasma prolactin. A single maximum (at 13:00 h) was found for adenohypophysial DA concentration. Individual adenohypophysial DA concentrations correlated significantly with their respective plasma prolactin levels. A maximum in median eminence 5HT concentration occurred at 21:00 h whereas adenohypophysial 5HT peaked at 13:00 h. Median eminence 5HT concentration and circulating prolactin correlated inversely. In the median eminence, GABA concentration attained maximal values at 21:00 h, whereas it reached a maximum at 13:00 h in the pituitary gland. Median eminence GABA concentration correlated inversely with circulating prolactin. In the median eminence, taurine values varied in a bimodal way showing two maxima, at the second half of the rest span and of the activity phase, respectively. In the adenohypophysis, minimal taurine levels coincided with the major plasma prolactin peak (at 01:00 h). Circulating prolactin and adenohypophysial taurine levels correlated inversely

  5. 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…

  6. Correlates of negative attitudes toward gay men: sexism, male role norms, and male sexuality.

    PubMed

    Davies, Michelle

    2004-08-01

    Research has shown that heterosexual men are more negative toward gay men than women are on measures of attitudes toward homosexual behaviour and homosexual persons (Kite & Whitley, 1996). Gender differences in attitudes toward gay men's civil rights are less clear. No empirical studies, however, have investigated these findings with a scale that measures specifically these three attitudinal subcomponents. This study was a preliminary test of a scale that measured these subcomponents. In addition, this study investigated the relationship between these subcomponents and other attitudinal measures: hostile sexism, male toughness, and attitudes toward male sexuality. Results revealed that attitudes toward homosexual behaviour and homosexual persons comprised one factor: affective reactions toward gay men. Results showed that men were more negative on affective reactions than women were. No gender differences were revealed on attitudes toward civil rights. I found significant correlations between affective reactions, hostile sexism, male toughness, and male sexuality. I discuss these findings in relation to traditional gender role beliefs and make suggestions for future research.

  7. Speech Rate in Males, Females, and Male-to-Female Transsexuals

    ERIC Educational Resources Information Center

    Van Borsel, John; De Maesschalck, Dorothy

    2008-01-01

    For clinicians treating transsexual clients it is important to address primarily those characteristics whose modification is most relevant to the creation of the desired gender presentation. The present study investigated the extent to which a modification of speech rate is warranted in male-to-female transsexuals. Comparison of speech rate…

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

    SciTech Connect

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

    1996-02-16

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

  9. Relation between male obesity and male infertility in a Tunisian population.

    PubMed

    Hadjkacem Loukil, L; Hadjkacem, H; Bahloul, A; Ayadi, H

    2015-04-01

    Obesity is associated with significant disturbance in the hormonal milieu that can affect the reproductive system. Male infertility affects approximately 6% of reproductive-aged men. It has been suggested that overweight men or men with obese body mass index (BMI) experience prolonged time to pregnancy, although the influence of male BMI on fertility remains understudied. We hypothesised that BMI is inversely correlated with fertility, manifested by reduced sperm concentration and varicocele. Males of mean age 32.74 ± 6.96 years with semen analyses and self-reported BMI were included (n = 98). Patient parameters analysed included age, BMI, pubertal timing, the development of varicocele, and leutinizing hormone, follicle-stimulating hormone and testosterone (n = 18). The mean age of the study population was 32.74 ± 6.96 years. The incidence of azospermia, oligozoospermia, normospermia and the development of varicocele did not vary across BMI categories. Male obesity is not associated with the incidence of sperm concentration and the development of varicocele.

  10. The Drosophila melanogaster hybrid male rescue gene causes inviability in male and female species hybrids.

    PubMed Central

    Barbash, D A; Roote, J; Ashburner, M

    2000-01-01

    The Drosophila melanogaster mutation Hmr rescues inviable hybrid sons from the cross of D. melanogaster females to males of its sibling species D. mauritiana, D. simulans, and D. sechellia. We have extended previous observations that hybrid daughters from this cross are poorly viable at high temperatures and have shown that this female lethality is suppressed by Hmr and the rescue mutations In(1)AB and D. simulans Lhr. Deficiencies defined here as Hmr(-) also suppressed lethality, demonstrating that reducing Hmr(+) activity can rescue otherwise inviable hybrids. An Hmr(+) duplication had the opposite effect of reducing the viability of female and sibling X-male hybrid progeny. Similar dose-dependent viability effects of Hmr were observed in the reciprocal cross of D. simulans females to D. melanogaster males. Finally, Lhr and Hmr(+) were shown to have mutually antagonistic effects on hybrid viability. These data suggest a model where the interaction of sibling species Lhr(+) and D. melanogaster Hmr(+) causes lethality in both sexes of species hybrids and in both directions of crossing. Our results further suggest that a twofold difference in Hmr(+) dosage accounts in part for the differential viability of male and female hybrid progeny, but also that additional, unidentified genes must be invoked to account for the invariant lethality of hybrid sons of D. melanogaster mothers. Implications of our findings for understanding Haldane's rule-the observation that hybrid breakdown is often specific to the heterogametic sex-are also discussed. PMID:10747067

  11. Childhood Predictors of Young Adult Male Crime.

    PubMed

    Ou, Suh-Ruu; Reynolds, Arthur J

    2010-08-01

    The study sample was drawn from the Chicago Longitudinal Study (CLS), an ongoing investigation of a panel of low-income minority children (93% Black) growing up in high-poverty neighborhoods in Chicago. The study sample included 733 males who were active by age 26. Adult criminal records were collected through administrative records and supplemented with self-reports. Outcome measures included incarceration, conviction, and felony conviction by age 26. Probit regression was used to analyze the data. Findings indicated that common childhood predictors were AFDC participation by child's age 3, negative home environment, maltreatment experience, trouble making behavior, and number of school moves. Unique predictors were mother unemployed by child's age 3 for incarceration or jail, four or more children in household by child's age 3 for felony conviction, and mother did not complete high school by child's age 3 and social competence for both incarceration or jail and felony conviction. Implications on crime prevention were discussed.

  12. Reality television and the muscular male ideal.

    PubMed

    Dallesasse, Starla L; Kluck, Annette S

    2013-06-01

    Although researchers have examined the negative effects of viewing reality television (RTV) on women's body image, this research has not been extended to men. Exploring the extent to which RTV depicts men who embody the muscular ideal may enhance our understanding of the potential influence of this media genre. We explored the extent to which RTV depicted men who embodied the muscular ideal using a quantitative content analysis. Based on binomial tests, the primary male cast members of programs airing on networks popular among young adult men during the Fall 2009 broadcast season were more muscular, with lower levels of body fat, than average U.S. men. The chest-to-waist and shoulder-to-waist ratios of these cast members did not differ as a function of program type (i.e., reality drama, endurance, and romance). Young men who view RTV programs included in the present study would be exposed to an unrepresentative muscular ideal.

  13. Skill deficits and male adolescent delinquency.

    PubMed

    Dishion, T J; Loeber, R; Stouthamer-Loeber, M; Patterson, G R

    1984-03-01

    The research literature on juvenile delinquency shows that antisocial adolescents are often lacking in academic, interpersonal, and work skills. Past research on antisocial adolescents has focused primarily on the relationship between single skill deficits and official delinquency. The present report extends this body of literature by investigating the relationship between seven measures of skill and official and self-reported delinquency in a nonclinical sample of 70 white male adolescents. Youths classified as delinquent on the basis of prior police contact had a lower multivariate profile on seven measures of academic, interpersonal, and work skills. Five of the seven measures correlated significantly with both the official and self-reported criteria of delinquency. Academic skill deficits may be the strongest covariates of antisocial behavior.

  14. Management of the male urethra after cystectomy.

    PubMed

    White, Shawn E; Malkowicz, S Bruce

    2010-08-01

    Approximately 70,000 new cases of bladder cancer are diagnosed yearly, of which 52,000 are male patients. In 2009 there were approximately 14,000 deaths attributed to bladder cancer, 10,000 of which were men. Approximately 40% to 45% of all cases are high-grade tumors with half of these being muscle-invasive tumors at the time of diagnosis. With the preponderance of men in this population, there is a need for clear management strategies regarding the retained urethra in those men undergoing radical cystectomy. This article reviews the incidence of urothelial carcinoma in the retained urethra, risk factors for the development of urethral urothelial carcinoma, surveillance strategies, treatment modalities, and outcomes following intervention.

  15. 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.

  16. Dedifferentiated liposarcoma of the adult male breast

    PubMed Central

    Raj, Sean D.; Rogers, Samuel; del Junco, Gerard W.; Sepulveda, Karla

    2015-01-01

    A 66-year-old male presented with a right breast mass, enlarging insidiously over a one-year period after trauma to the site. After the findings were attributed to glandular injury and hematoma, the patient eventually underwent mammographic and ultrasonographic evaluation that demonstrated masses in the breast and the axilla. A subsequent ultrasound-guided biopsy of the breast mass yielded a diagnosis of fibromatosis. However, the imaging features were suggestive of malignancy. Surgical resection was performed and revealed dedifferentiated liposarcoma—a neoplasm with components of well- and poorly differentiated liposarcoma as well as nonlipomatous sarcoma. This tumor type is primarily described in the retroperitoneum and limbs and is especially rare in the breast. We report an unusual case of multifocal primary dedifferentiated liposarcoma involving the breast in a man. PMID:27186240

  17. Dedifferentiated liposarcoma of the adult male breast.

    PubMed

    Raj, Sean D; Rogers, Samuel; Del Junco, Gerard W; Sepulveda, Karla

    2014-01-01

    A 66-year-old male presented with a right breast mass, enlarging insidiously over a one-year period after trauma to the site. After the findings were attributed to glandular injury and hematoma, the patient eventually underwent mammographic and ultrasonographic evaluation that demonstrated masses in the breast and the axilla. A subsequent ultrasound-guided biopsy of the breast mass yielded a diagnosis of fibromatosis. However, the imaging features were suggestive of malignancy. Surgical resection was performed and revealed dedifferentiated liposarcoma-a neoplasm with components of well- and poorly differentiated liposarcoma as well as nonlipomatous sarcoma. This tumor type is primarily described in the retroperitoneum and limbs and is especially rare in the breast. We report an unusual case of multifocal primary dedifferentiated liposarcoma involving the breast in a man.

  18. Male chronic pelvic pain: An update

    PubMed Central

    Smith, Christopher P.

    2016-01-01

    Introduction: Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and interstitial cystitis/bladder pain syndrome collectively referred to as urologic CPPS (UCPPS) is defined by the absence of identifiable bacterial infection as a cause for the chronic pain and urinary symptoms. Methods: A PubMed search of all recent relevant articles using the keywords/phrases: CPPS, CPPS, and male pelvic pain, was conducted. Results: CPPS has a high worldwide prevalence and its negative impact on quality of life compares with or exceeds common chronic morbidities. Triggers include certain comestibles as well as psychosocial factors that promote catastrophizing and illness focused behavior. Several validated tools are currently available to help diagnose and direct targeted therapy. Treatment should begin with the most simple and least invasive based on the presenting clinical phenotype. Conclusions: Although no gold-standard treatment exists, a multidisciplinary approach with multimodal therapy gives the UCPPS patient the best chance of symptom relief. PMID:26941492

  19. Electroencephalographic changes with age in male mice.

    PubMed

    Eleftheriou, B E; Zolovick, A J; Elias, M F

    1975-01-01

    Electroencephalographic (EEG) changes, as measured by the awake state, slow-wave sleep (SWS), rapid-eye movement (REM) patterns and ratio of REM/total sleep, were recorded in aging male mice of DBA/2J and C57BL/6J strains. Results indicate that there is a significant increase in the awake state accompanied by significant decrease in SWS with advancing age for both strains, although these changes appear more pronounced in DBA/2J mice than C57BL/6J mice. Of considerable significance is the finding that REM sleep is absent in mice of DBA/2J strain at 23.5 months of age. Based on these findings, the conclusion was reached that strain DBA/2J ages significantly faster than C57BL/6J. The difference in aging between the two strains emphasizes the need for additional studies dealing with genetic aspects of aging.

  20. A young male with familial hypercholesterolemia

    PubMed Central

    Rahman, Afzalur; Ahmed, Moeen Uddin; Islam, A.K.M. Monwarul; Karim, Aparajita; Sarker, Shafiqul A.

    2012-01-01

    Summary A nine-year-old Bangladeshi male with a body mass index 16.5 kg/m2 presented with progressive tuberous xanthomata on both auricles, elbows, gluteal regions and legs since birth. His father, paternal and maternal grandfather had xanthelasma, however, the siblings had none. Examination of the cardiovascular system was otherwise normal. Laboratory investigations were performed on several occasions since he was 4 years of age and revealed extreme dyslipidaemia with very high total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein B (Apo-B) and lipoprotein(a), and low apolipoprotein-A (Apo-A) levels. Repeated combination of lipid lowering agents with cholestyramine, atorvastatin and ezetimibe were virtually ineffective in improving the lipid profiles. Supplementation therapy with niacin also had no effect. In view of the unavailability in Bangladesh of lipid apheresis, the cornerstone of therapy, the management of the case becomes complicated. PMID:24174835

  1. Obesity and male infertility: a practical approach.

    PubMed

    Hammoud, Ahmad O; Meikle, A Wayne; Reis, Leonardo Oliveira; Gibson, Mark; Peterson, C Matthew; Carrell, Douglas T

    2012-12-01

    Obesity in men is associated with infertility in numerous studies, and the temporal trend for a decline in semen parameters parallels the increasing prevalence of obesity in the developed world. In addition to impaired semen quality, fertility among obese men may be affected by decreased libido and erectile dysfunction. This spectrum of expression of hypogonadism among obese men originates from multiple interacting factors including reduced levels of gonadotropins and testosterone, altered androgen-to-estrogen ratios, insulin resistance, and sleep apnea. No evidence-based treatment that increases the likelihood of pregnancy for the infertility associated with male obesity has been demonstrated to date. Interventions associated with improvement of intermediate outcomes that include the endocrine profile, semen parameters, and sexual function may be appropriately selected based on history, physical findings, as well as endocrine and metabolic evaluation. Among these interventions are weight loss through lifestyle change, relief from sleep apnea, use of aromatase inhibitors, gonadotropin administration, phosphodiesterase inhibitors, and insulin-sensitizing agents.

  2. Male infertility and varicocele: myths and reality

    PubMed Central

    Kantartzi, P D; Goulis, Ch D; Goulis, G D; Papadimas, I

    2007-01-01

    Varicocele is among the most common causes of male infertility. It is also one of the most controversial issues in the field of Andrology, especially regarding why, when and to whom varicocelectomy should be applied. Many experts believe that the surgical repair of varicocele should be applied only in a meticulously selected group of infertile men, although there are no generally accepted criteria. Up to now, the only confirmed prognostic factor for achievement of pregnancy after varicocelectomy is the age of the female partner. Given the wide application of intra - cytoplasmic sperm injection (ICSI) during the last few years, the modern research approaches should compare the benefits of varicocelectomy and ICSI, taking under consideration both the efficacy and the cost-effectiveness of the methods. PMID:19582201

  3. Male pseudohermaphroditism: genetics and clinical delineation.

    PubMed

    Simpson, J L

    1978-10-19

    The genetics and clinical delineation of male pseudohermaphroditism are reviewed. These disorders are categorized initially by their genetic etiology--cytogenetic, Mendelian, or teratogenic. It is especially important to distinguish cytogenetic forms, usually associated with 45,X/46,XY mosaicism, from Mendelian (genetic) forms because in the former the prevalence of gonadoblastomas or dysgerminomas is about 15--20%. Genetic forms include (1) those associated with a multiple malformation pattern, (2) those due to an error in adrenal or testicular hormonal biosynthesis, (3) complete testicular feminization, (4) incomplete testicular feminization, (5) Reifenstein syndrome, (6) pseudovaginal perineoscrotal hypospadias, and (7) agondia, and possibly other conditions. Incomplete testicular feminization and the Reifenstein syndrome may or may not represent varied expressivity of the same trait. The designation pseudovaginal perineoscrotal hypospadias is appropriate only if constellations of clinical features are present and if no metabolic abnormalities are demonstrable. Etiology and available genetic data are reviewed for each of these disorders.

  4. Male bisexual arousal: a matter of curiosity?

    PubMed

    Rieger, Gerulf; Rosenthal, Allen M; Cash, Brian M; Linsenmeier, Joan A W; Bailey, J Michael; Savin-Williams, Ritch C

    2013-12-01

    Conflicting evidence exists regarding whether bisexual-identified men are sexually aroused to both men and women. We hypothesized that a distinct characteristic, level of curiosity about sexually diverse acts, distinguishes bisexual-identified men with and without bisexual arousal. Study 1 assessed men's (n=277) sexual arousal via pupil dilation to male and female sexual stimuli. Bisexual men were, on average, higher in their sexual curiosity than other men. Despite this general difference, only bisexual-identified men with elevated sexual curiosity showed bisexual arousal. Those lower in curiosity had responses resembling those of homosexual men. Study 2 assessed men's (n=72) sexual arousal via genital responses and replicated findings of Study 1. Study 3 provided information on the validity on our measure of sexual curiosity by relating it to general curiosity and sexual sensation seeking (n=83). Based on their sexual arousal and personality, at least two groups of men identify as bisexual.

  5. [Eating disorders in males: a representative survey].

    PubMed

    Kinzl, J F; Traweger, C; Trefalt, E; Mangweth, B; Biebl, W

    1998-12-01

    The present study examined the prevalence of eating disorders in a male representative random sample in Tyrol. The data were collected by telephone. Of the 1000 men, 8 (0.8%) met the DSM-IV diagnostic criteria for binge eating disorder. An additional 42 subjects (4.2%) exhibited a partial binge eating syndrome. These two otherwise widely identical groups of binge eaters were separated only by the DSM-IV frequency criterion. Five subjects (0.5%) met the DSM-IV criteria for the diagnosis of bulimia nervosa, and 94 men (9.4%) reported recurrent overeating. Men with any eating disorder were mostly overweight or obese. The findings show that there is a significant difference in eating disorders between men and women, but certain eating disorders are frequent not only in women but also in men.

  6. Integration of male bisexuality and marriage.

    PubMed

    Coleman, E

    1985-01-01

    Eighteen couples who had originally entered therapy because of conflicts created by the husband's bisexuality were studied to determine the dynamics and adjustment of their marriages. All the couples, to varying degrees, had been openly dealing with the husband's bisexuality for at least two years. Through questionnaires and psychological instruments, couples indicated that openness and communication helped the relationship. The greatest difficulties they encountered were in their sexual relationships. Marital satisfaction and adjustment was found to be negatively correlated with increasing age, number of children, later onset of homosexual activities, increased emotional involvement with male partners, increased numbers of people who know about the husband's homosexual activities, and increased sexual dissatisfaction and conflict. Basically, this study reinforced the notion that some marriages can survive by way of open communication, acceptance and understanding, dynamics which help compensate for the inherent conflicts these couples face.

  7. Oxidative stress and male reproductive health

    PubMed Central

    Aitken, Robert J; Smith, Tegan B; Jobling, Matthew S; Baker, Mark A; De Iuliis, Geoffry N

    2014-01-01

    One of the major causes of defective sperm function is oxidative stress, which not only disrupts the integrity of sperm DNA but also limits the fertilizing potential of these cells as a result of collateral damage to proteins and lipids in the sperm plasma membrane. The origins of such oxidative stress appear to involve the sperm mitochondria, which have a tendency to generate high levels of superoxide anion as a prelude to entering the intrinsic apoptotic cascade. Unfortunately, these cells have very little capacity to respond to such an attack because they only possess the first enzyme in the base excision repair (BER) pathway, 8-oxoguanine glycosylase 1 (OGG1). The latter successfully creates an abasic site, but the spermatozoa cannot process the oxidative lesion further because they lack the downstream proteins (APE1, XRCC1) needed to complete the repair process. It is the responsibility of the oocyte to continue the BER pathway prior to initiation of S-phase of the first mitotic division. If a mistake is made by the oocyte at this stage of development, a mutation will be created that will be represented in every cell in the body. Such mechanisms may explain the increase in childhood cancers and other diseases observed in the offspring of males who have suffered oxidative stress in their germ line as a consequence of age, environmental or lifestyle factors. The high prevalence of oxidative DNA damage in the spermatozoa of male infertility patients may have implications for the health of children conceived in vitro and serves as a driver for current research into the origins of free radical generation in the germ line. PMID:24369131

  8. Human male meiotic sex chromosome inactivation.

    PubMed

    de Vries, Marieke; Vosters, Sanne; Merkx, Gerard; D'Hauwers, Kathleen; Wansink, Derick G; Ramos, Liliana; de Boer, Peter

    2012-01-01

    In mammalian male gametogenesis the sex chromosomes are distinctive in both gene activity and epigenetic strategy. At first meiotic prophase the heteromorphic X and Y chromosomes are placed in a separate chromatin domain called the XY body. In this process, X,Y chromatin becomes highly phosphorylated at S139 of H2AX leading to the repression of gonosomal genes, a process known as meiotic sex chromosome inactivation (MSCI), which has been studied best in mice. Post-meiotically this repression is largely maintained. Disturbance of MSCI in mice leads to harmful X,Y gene expression, eventuating in spermatocyte death and sperm heterogeneity. Sperm heterogeneity is a characteristic of the human male. For this reason we were interested in the efficiency of MSCI in human primary spermatocytes. We investigated MSCI in pachytene spermatocytes of seven probands: four infertile men and three fertile controls, using direct and indirect in situ methods. A considerable degree of variation in the degree of MSCI was detected, both between and within probands. Moreover, in post-meiotic stages this variation was observed as well, indicating survival of spermatocytes with incompletely inactivated sex chromosomes. Furthermore, we investigated the presence of H3K9me3 posttranslational modifications on the X and Y chromatin. Contrary to constitutive centromeric heterochromatin, this heterochromatin marker did not specifically accumulate on the XY body, with the exception of the heterochromatic part of the Y chromosome. This may reflect the lower degree of MSCI in man compared to mouse. These results point at relaxation of MSCI, which can be explained by genetic changes in sex chromosome composition during evolution and candidates as a mechanism behind human sperm heterogeneity.

  9. Human Male Meiotic Sex Chromosome Inactivation

    PubMed Central

    de Vries, Marieke; Vosters, Sanne; Merkx, Gerard; D'Hauwers, Kathleen; Wansink, Derick G.; Ramos, Liliana; de Boer, Peter

    2012-01-01

    In mammalian male gametogenesis the sex chromosomes are distinctive in both gene activity and epigenetic strategy. At first meiotic prophase the heteromorphic X and Y chromosomes are placed in a separate chromatin domain called the XY body. In this process, X,Y chromatin becomes highly phosphorylated at S139 of H2AX leading to the repression of gonosomal genes, a process known as meiotic sex chromosome inactivation (MSCI), which has been studied best in mice. Post-meiotically this repression is largely maintained. Disturbance of MSCI in mice leads to harmful X,Y gene expression, eventuating in spermatocyte death and sperm heterogeneity. Sperm heterogeneity is a characteristic of the human male. For this reason we were interested in the efficiency of MSCI in human primary spermatocytes. We investigated MSCI in pachytene spermatocytes of seven probands: four infertile men and three fertile controls, using direct and indirect in situ methods. A considerable degree of variation in the degree of MSCI was detected, both between and within probands. Moreover, in post-meiotic stages this variation was observed as well, indicating survival of spermatocytes with incompletely inactivated sex chromosomes. Furthermore, we investigated the presence of H3K9me3 posttranslational modifications on the X and Y chromatin. Contrary to constitutive centromeric heterochromatin, this heterochromatin marker did not specifically accumulate on the XY body, with the exception of the heterochromatic part of the Y chromosome. This may reflect the lower degree of MSCI in man compared to mouse. These results point at relaxation of MSCI, which can be explained by genetic changes in sex chromosome composition during evolution and candidates as a mechanism behind human sperm heterogeneity. PMID:22355370

  10. Old-male paternity advantage is a function of accumulating sperm and last-male precedence in a butterfly.

    PubMed

    Kehl, Tobias; Karl, Isabell; Fischer, Klaus

    2013-08-01

    Old-male mating advantage has been convincingly demonstrated in Bicyclus anynana butterflies. This intriguing pattern may be explained by two alternative hypotheses: (i) an increased aggressiveness and persistence of older males during courtship, being caused by the older males' low residual reproductive value; and (ii) an active preference of females towards older males what reflects a good genes hypothesis. Against this background, we here investigate postcopulatory sexual selection by double-mating Bicyclus anynana females to older and younger males, thus allowing for sperm competition and cryptic mate choice, and by genotyping the resulting offspring. Virgin females were mated with a younger virgin (2-3 days old) and afterwards an older virgin male (12-13 days old) or vice versa. Older males had a higher paternity success than younger ones, but only when being the second (=last) mating partner, while paternity success was equal among older and younger males when older males were the first mating partner. Older males produced larger spermatophores with much higher numbers of fertile sperm than younger males. Thus, we found no evidence for cryptic female mate choice. Rather, the findings reported here seem to result from a combination of last-male precedence and the number of sperm transferred upon mating, both increasing paternity success.

  11. "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…

  12. Male-male sexual behavior in Japanese quail: being "on top" reduces mating and fertilization with females.

    PubMed

    Adkins-Regan, Elizabeth

    2014-10-01

    Male Japanese quail (Coturnix japonica) engage in vigorous same-sex sexual interactions that have been interpreted as aggressive behavior reflecting dominance relationships. The consequences of this behavior for reproductive success, and whether it is a form of competition over mating and fertilization, are unclear. Three experiments were conducted to determine the effect of seeing or interacting with another male on a male's subsequent mating and fertilization success with females. A vigorous interaction with another male in which the subject performed more cloacal contact movements (movements to try to make contact with the other bird's cloacal opening) reduced subsequent mating and fertilization success with a female to a similar extent as a prior mating with a different female. Receiving one or more cloacal contacts from another male was less detrimental for subsequent success. The mere presence of another (stimulus) male delayed mating initiation in those male subjects that approached the stimulus first instead of the female. These results do not support the idea that the male "on top" in male-male sexual interactions is the dominant bird who goes on to achieve greater reproductive success. Instead, the results are consistent with male-male sexual behavior as an occasionally costly by-product of strong mating motivation.

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

    PubMed

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

    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.

  14. Counseling parents who are considering newborn male circumcision.

    PubMed

    Mielke, Ruth T

    2013-01-01

    The American Academy of Pediatrics recently issued a statement that the health benefits of newborn male circumcision exceed the risks and therefore justify access to the procedure for families who choose it. Further, clinicians are charged with providing factually correct information that communicates the risks and benefits of elective newborn male circumcision in a nonbiased manner. However, many clinicians lack adequate information to discuss the risks and benefits of male circumcision. The purpose of this review is to highlight evidence on the risks and benefits of newborn male circumcision and provide clinicians with counseling points that can be used to guide discussion with parents considering newborn male circumcision.

  15. 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

  16. Current medical management of endocrine-related male infertility.

    PubMed

    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.

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

    PubMed

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

    2016-06-01

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

  18. Steroid-independent male sexual behavior in B6D2F2 male mice.

    PubMed

    McInnis, Christine M; Venu, Samitha; Park, Jin Ho

    2016-09-01

    It is well established that male sexual behavior (MSB) is regulated by gonadal steroids; however, individual differences in MSB, independent of gonadal steroids, are prevalent across a wide range of species, and further investigation is necessary to advance our understanding of steroid-independent MSB. Studies utilizing B6D2F1 hybrid male mice in which a significant proportion retain MSB after long-term orchidectomy, identified as steroid-independent-maters (SI-maters), have begun to unravel the genetic underpinnings of steroid-independent MSB. A recent study demonstrated that steroid-independent MSB is a heritable behavioral phenotype that is mainly passed down from B6D2F1 hybrid SI-maters when crossed with C57BL6J female mice. To begin to uncover whether the strain of the dam plays a role in the inheritance of steroid-independent MSB, B6D2F1 hybrid females were crossed with B6D2F1 hybrid males. While the present study confirms the finding that steroid-independent MSB is a heritable behavioral phenotype and that SI-mater sires are more likely to pass down some components of MSB than SI-non-maters to their offspring, it also reveals that the B6D2F2 male offspring that were identified as SI-maters that displayed the full repertoire of steroid-independent MSB had the same probability of being sired from either a B6D2F1 SI-mater or SI-non-mater. These results, in conjunction with previous findings, indicate that the specific chromosomal loci pattern that codes for steroid-independent MSB in the B6D2F2 male offspring may result regardless of whether the father was a SI-mater or SI-non-mater, and that the maternal strain may be an important factor in the inheritance of steroid-independent MSB.

  19. 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.

  20. 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

  1. Trade-Offs in Male Display Activity with Lek Size.

    PubMed

    Cestari, César; Loiselle, Bette A; Pizo, Marco Aurélio

    In lek mating systems, males aggregate and defend arenas where they display for females; females select and mate with a male and then solely raise their offspring. Generally, female visits and copulations increase and reproductive variance in male mating success declines with lek size. Here we investigate how male display effort changes across a gradient in lek size. We expect male display effort, an energetically expensive activity, will increase with lek size and male rank due to changes in breeding opportunities and competition among males. We test the interaction of male rank and lek size on display effort using the white-bearded manakin, Manacus manacus (Aves: Pipridae), a well-studied species with a wide geographic distribution in the new world tropics. We used mini-video recorders to simultaneously capture female visits and display behaviors of 41 males distributed over 10 leks. We found that overall display effort increased disproportionately with lek size due to males of both high and low ranks increasing their display effort at larger leks. Our results suggest that increased breeding opportunities and intrasexual competition at larger leks result in males of different ranks investing similarly in increased display effort in order to attract females.

  2. Microchimerism of male origin in a cohort of Danish girls.

    PubMed

    Müller, Amanda Cecilie; Jakobsen, Marianne Antonius; Barington, Torben; Vaag, Allan Arthur; Grunnet, Louise Groth; Olsen, Sjurdur Frodi; Kamper-Jørgensen, Mads

    2015-10-02

    Male microchimerism, the presence of a small number of male cells, in women has been attributed to prior pregnancies. However, male microchimerism has also been reported in women with only daughters, in nulliparous women and prepubertal girls suggesting that other sources of male microchimerism must exist. The aim of the present study was to examine the presence of male microchimerism in a cohort of healthy nulliparous Danish girls aged 10-15 y using DNA extracted from cells from whole blood (buffy coats) and report the association with potential sources of male cells. A total of 154 girls were studied of which 21 (13.6%) tested positive for male microchimerism. There was a tendency that girls were more likely to test positive for male microchimerism if their mothers previously had received transfusion, had given birth to a son or had had a spontaneous abortion. Furthermore, the oldest girls were more likely to test positive for male microchimerism. However, less than half of microchimerism positivity was attributable to these factors. In conclusion, data suggest that male microchimerism in young girls may originate from an older brother either full born or from a discontinued pregnancy or from transfusion during pregnancy. We speculate that sexual intercourse may be important but other sources of male cells likely exist in young girls.

  3. Trade-Offs in Male Display Activity with Lek Size

    PubMed Central

    Cestari, César; Loiselle, Bette A.; Pizo, Marco Aurélio

    2016-01-01

    In lek mating systems, males aggregate and defend arenas where they display for females; females select and mate with a male and then solely raise their offspring. Generally, female visits and copulations increase and reproductive variance in male mating success declines with lek size. Here we investigate how male display effort changes across a gradient in lek size. We expect male display effort, an energetically expensive activity, will increase with lek size and male rank due to changes in breeding opportunities and competition among males. We test the interaction of male rank and lek size on display effort using the white-bearded manakin, Manacus manacus (Aves: Pipridae), a well-studied species with a wide geographic distribution in the new world tropics. We used mini-video recorders to simultaneously capture female visits and display behaviors of 41 males distributed over 10 leks. We found that overall display effort increased disproportionately with lek size due to males of both high and low ranks increasing their display effort at larger leks. Our results suggest that increased breeding opportunities and intrasexual competition at larger leks result in males of different ranks investing similarly in increased display effort in order to attract females. PMID:27680489

  4. Male androphilia in the ancestral environment. An ethnological analysis.

    PubMed

    VanderLaan, Doug P; Ren, Zhiyuan; Vasey, Paul L

    2013-12-01

    The kin selection hypothesis posits that male androphilia (male sexual attraction to adult males) evolved because androphilic males invest more in kin, thereby enhancing inclusive fitness. Increased kin-directed altruism has been repeatedly documented among a population of transgendered androphilic males, but never among androphilic males in other cultures who adopt gender identities as men. Thus, the kin selection hypothesis may be viable if male androphilia was expressed in the transgendered form in the ancestral past. Using the Standard Cross-Cultural Sample (SCCS), we examined 46 societies in which male androphilia was expressed in the transgendered form (transgendered societies) and 146 comparison societies (non-transgendered societies). We analyzed SCCS variables pertaining to ancestral sociocultural conditions, access to kin, and societal reactions to homosexuality. Our results show that ancestral sociocultural conditions and bilateral and double descent systems were more common in transgendered than in non-transgendered societies. Across the entire sample, descent systems and residence patterns that would presumably facilitate increased access to kin were associated with the presence of ancestral sociocultural conditions. Among transgendered societies, negative societal attitudes toward homosexuality were unlikely. We conclude that the ancestral human sociocultural environment was likely conducive to the expression of the transgendered form of male androphilia. Descent systems, residence patterns, and societal reactions to homosexuality likely facilitated investments in kin by transgendered males. Given that contemporary transgendered male androphiles appear to exhibit elevated kin-directed altruism, these findings further indicate the viability of the kin selection hypothesis.

  5. Toxic Effect of Blood Feeding in Male Mosquitoes

    PubMed Central

    Nikbakhtzadeh, Mahmood R.; Buss, Garrison K.; Leal, Walter S.

    2016-01-01

    Blood- and sugar feeding of female mosquitoes has been frequently observed in the laboratory and in the field, but only sugar feeding of males has been reported. Here, we describe for the first time that Culex quinquefasciatus males feed on blood as well. Blood feeding easily happened on a blood-soaked cotton roll and, to a lesser extent, through a thin artificial layer. Mating history of a male specimen does not affect his blood feeding behavior. Male mosquitoes feed on blood even when they have a readily available sugar source. Nevertheless, feeding on blood reduces the survival rate of males to just a few days, as compared to more than a month for mosquitoes fed only on sugar. Comparing survival of male mosquitoes fed on blood only, sugar only, and a combination of both clearly demonstrated that mortality is not affected by malnutrition (reduced sugar levels), but rather due to ingested blood. On average male mosquitoes ingested ca. 0.5 μl of blood, i.e., about 10% of the amount of blood ingested by an engorged female. Although this unexpected observation of blood feeding in the laboratory by male mosquitoes is interesting, structural impairment prevents male feeding on vertebrate blood. In agreement with the literature, male and female proboscises and stylets were in general of similar size, but male mandibles were significantly shorter than female counterparts, thus explaining their inability to pierce through skin layers. PMID:26858651

  6. Comparative reproductive output of androphilic and gynephilic males in samoa.

    PubMed

    Vasey, Paul L; Parker, Jessica L; VanderLaan, Doug P

    2014-02-01

    Debate exists in the behavioral sciences regarding the extent to which androphilic males reproduce compared to their gynephilic counterparts. Quantitative data that might speak to this debate are surprisingly rare. Here, we compared the reproductive output of 235 transgendered, exclusively androphilic Samoan males (known locally as fa'afafine) to that of 447 exclusively gynephilic Samoan males. Samoan gynephilic male participants fathered significantly more children than fa'afafine participants. In fact, none of the fa'afafine in our sample produced offspring. On the basis of this evidence and anecdotal accounts in the anthropological literature, we contend that absence of reproductive output is a near absolute cross-cultural universal characterizing non-Western, transgendered androphilic ("third-gender") males. Models for the evolution of male androphilia must account for how genes associated with this sexual orientation originated in the past and persisted in populations over time despite the fact that the vast majority of androphilic males have no direct reproductive success.

  7. Nectar amino acids enhance reproduction in male butterflies.

    PubMed

    Cahenzli, Fabian; Erhardt, Andreas

    2013-01-01

    After over 30 years of research, it was recently shown that nectar amino acids increase female butterfly fecundity. However, little attention has been paid to the effect of nectar amino acids on male butterfly reproduction. Here, we show that larval food conditions (nitrogen-rich vs. nitrogen-poor host plants) and adult diet quality (nectar with or without amino acids) affected the amount of consumed nectar in Coenonympha pamphilus males. Furthermore, amino acids in the nectar diet of males increased progeny's larval hatching mass, irrespective of paternal larval reserves. Our study takes the whole reproductive cycle of male butterflies into account, and also considers the role of females in passing male nutrients to offspring, as males' realized reproduction was examined indirectly via nuptial gifts, by female performance. With this comprehensive approach, we demonstrate for the first time that nectar amino acids can improve male butterfly reproduction, supporting the old postulate that nectar amino acids generally enhance butterfly fitness.

  8. Tapetum and middle layer control male fertility in Actinidia deliciosa

    PubMed Central

    Falasca, Giuseppina; D'Angeli, Simone; Biasi, Rita; Fattorini, Laura; Matteucci, Maja; Canini, Antonella; Altamura, Maria Maddalena

    2013-01-01

    Background and Aims Dioecism characterizes many crop species of economic value, including kiwifruit (Actinidia deliciosa). Kiwifruit male sterility occurs at the microspore stage. The cell walls of the microspores and the pollen of the male-sterile and male-fertile flowers, respectively, differ in glucose and galactose levels. In numerous plants, pollen formation involves normal functioning and degeneration timing of the tapetum, with calcium and carbohydrates provided by the tapetum essential for male fertility. The aim of this study was to determine whether the anther wall controls male fertility in kiwifruit, providing calcium and carbohydrates to the microspores. Methods The events occurring in the anther wall and microspores of male-fertile and male-sterile anthers were investigated by analyses of light microscopy, epifluorescence, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL assay) and transmission electron microscopy coupled with electron spectroscopy. The possibility that male sterility was related to anther tissue malfunctioning with regard to calcium/glucose/galactose provision to the microspores was also investigated by in vitro anther culture. Key Results Both tapetum and the middle layer showed secretory activity and both degenerated by programmed cell death (PCD), but PCD was later in male-sterile than in male-fertile anthers. Calcium accumulated in cell walls of the middle layer and tapetum and in the exine of microspores and pollen, reaching higher levels in anther wall tissues and dead microspores of male-sterile anthers. A specific supply of glucose and calcium induced normal pollen formation in in vitro-cultured anthers of the male-sterile genotype. Conclusions The results show that male sterility in kiwifruit is induced by anther wall tissues through prolonged secretory activity caused by a delay in PCD, in the middle layer in particular. In vitro culture results support the sporophytic control of male fertility

  9. Effects of age and communication level on eye contact in fragile X males and non-fragile X autistic males.

    PubMed

    Cohen, I L; Vietze, P M; Sudhalter, V; Jenkins, E C; Brown, W T

    1991-01-01

    Dyadic social gaze and eye contact were examined in fragile X [fra(X)] males and in non-fra(X) autistic males as a function of age and level of communicative ability. Lag sequential analysis showed that responsive eye contact was highly correlated with age and communicative ability in non-fra(X) autistic males but not in fra(X) males. Older, more communicative non-fra(X) autistic males exhibited more responsive eye contact than their fra(X) cohorts. Implications of these observations for theory and intervention are discussed.

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

    PubMed Central

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

    2017-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2017-02-06

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

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

    PubMed

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

    2015-01-01

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

  15. Can too strong female choice deteriorate male ornamentation?

    PubMed Central

    Morrell, Lesley J.; Kokko, Hanna

    2004-01-01

    Competition for limited resources can have fundamental implications for population dynamics. However, the effects of resource depletion have rarely been discussed in the context of sexual selection, even though mate choice typically favours males who outperform others in securing access to some limited resource. Here, we develop a model to investigate the question of resource competition as a form of male-male competition in the context of male sexual displays. We phrase our model in terms of male bowerbirds either searching for or stealing resources (ornamental objects) valued by females, and compare the model findings with published studies of time allocation to various activities in different species of bowerbirds. The basic idea of the model, however, extends to cases where the resource is used less directly for the development of sexual ornamentation, such as males excluding others' access to food. We show that if males compete for resources used in sexual displays, intense female preference for high-quality displays can lead to poorer prospects for efficient choice by females. This is because males benefit from excluding others' access to resources used in displays, damaging the overall efficiency of resource use in the population, and the accuracy with which females can judge male ability to gain such resources. The evolution of female choice may therefore have a self-limiting nature when it poses a selection pressure on male resource acquisition. PMID:15306306

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

    PubMed Central

    Ubuka, Takayoshi; Tsutsui, Kazuyoshi

    2014-01-01

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

  17. Insurance coverage for male infertility care in the United States.

    PubMed

    Dupree, James M

    2016-01-01

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

  18. Guarding males protect females from predation in a wild insect.

    PubMed

    Rodríguez-Muñoz, Rolando; Bretman, Amanda; Tregenza, Tom

    2011-10-25

    Males frequently remain in close proximity to their mate immediately postcopulation. This behavior has generally been interpreted as a guarding tactic designed to reduce the likelihood that a rival male can rapidly displace the ejaculate of the guarding male [1, 2]. Such attempts by males to control their mates represent a potential source of conflict [3-5], but guarding behaviors in species where it is difficult for males to control their mates suggest that conflict is not inevitable [6, 7]. We employed a network of infrared video cameras to study a wild population of individually marked and genotyped field crickets (Gryllus campestris). Lone females or males suffer similar rates of predation, but when a pair is attacked, the male allows the female priority access to their burrow, and in doing so dramatically increases his probability of being killed. In compensation for this increased predation risk, paired males mate more frequently and father more of the female's offspring. By staying with a male, females increase the sperm contribution of preferred males as well as reducing their predation risk. In contrast to conclusions based on previous lab studies, our field study suggests that mate guarding can evolve in a context of cooperation rather than conflict between the sexes.

  19. Copulatory courtship signals male genetic quality in cucumber beetles.

    PubMed Central

    Tallamy, Douglas W; Darlington, Mark Burton; Pesek, John D; Powell, Bradford E

    2003-01-01

    In the spotted cucumber beetle, Diabrotica undecimpunctata howardi (Coleoptera: Chrysomelidae), males court females during copulation by stroking them with their antennae. Stroking occurs exclusively during the first stages of copulation, after a male has penetrated a female's vaginal duct but before he is allowed access to her bursa copulatrix. Females accept the spermatophore of fast-stroking males and reject those of slow-stroking males by relaxing or constricting muscles distorting the vaginal duct. Here, we measure the repeatability of stroking behaviour within males, examine the effect of losing one antenna on male attractiveness and test whether such female control results in direct phenotypic benefits for the discriminating female or indirect genetic benefits that appear in her offspring. We also use a half-sibling design to quantify the variance and heritability of stroking speed and endurance. Female beetles were paired with a male that was known to stroke either quickly or slowly. No difference was found in the resulting fecundity or egg-hatching rate of the females, or in the survivorship, development rate, size, age at first reproduction or fecundity of their offspring indicating that no direct benefits are gained by discriminating among males on the basis of stroking speed. There were, however, good-genes benefits for the mates of fast-stroking males. Offspring of fast-stroking fathers were also fast strokers and were more likely to be accepted as mates than offspring of slow-stroking fathers. There was substantial variance among sires in stroking speed and endurance and the heritability of each trait was high. The antennal stroking rate was highly repeatable in successive mating attempts and males with only one antenna were not accepted as mates. The repeatability within males, variability between males and heritability between generations of copulatory stroking combine to provide females with a reliable and honest signal of the genetic quality of

  20. Nicotine alters male reproductive hormones in male albino rats: The role of cessation

    PubMed Central

    Oyeyipo, Ibukun P; Raji, Yinusa; Bolarinwa, Adeyombo F

    2013-01-01

    OBJECTIVES: The use of nicotine through smoking remains a serious health problem. It has been associated with reduced fertility, although the mechanism responsible is still unclear. The present study was designed to investigate whether nicotine-induced infertility is associated with altered male reproductive hormones in male albino rats. MATERIALS AND METHODS: Forty male rats were divided equally into five groups and treated orally for thirty days. Group I, which served as the control received 0.2 ml/kg normal saline, Group II and III received 0.5 mg/kg (low dose) and 1.0 mg/kg (high dose) body weight of nicotine, respectively. The fourth and fifth groups were gavaged with 0.5 mg/kg and 1.0 mg/kg body weight of nicotine but were left untreated for another 30 days. These groups served as the recovery groups. Serum was analyzed for testosterone, luteinizing hormone (LH), follicle stimulating hormones (FSH), and prolactin using radioimmunoassay. RESULTS: Results showed that nicotine administration significantly decreased (P < 0.05) testosterone in the low and high treated groups and FSH in the high dose treated group when compared with the control group. There was a significant increase (P < 0.05) in mean LH and prolactin level in the high dose treated group when compared with the control. However, the values of the recovery groups were comparable with the control. CONCLUSION: The findings in this study suggest that nicotine administration is associated with distorted reproductive hormones in male rats although ameliorated by nicotine cessation. It is plausible that the decreased testosterone level is associated with testicular dysfunction rather than a pituitary disorder. PMID:23869150

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

    PubMed Central

    Labbé, L.

    2016-01-01

    Juvenile sex ratios are often assumed to be equal for many species with genetic sex determination, but this has rarely been tested in fish embryos due to their small size and absence of sex-specific markers. We artificially crossed three populations of brown trout and used a recently developed genetic marker for sexing the offspring of both pure and hybrid crosses. Sex ratios (SR = proportion of males) varied widely one month after hatching ranging from 0.15 to 0.90 (mean = 0.39 ± 0.03). Families with high survival tended to produce balanced or male-biased sex ratios, but SR was significantly female-biased when survival was low, suggesting that males sustain higher mortality during development. No difference in SR was found between pure and hybrid families, but the existence of sire × dam interactions suggests that genetic incompatibility may play a role in determining sex ratios. Our findings have implications for animal breeding and conservation because skewed sex ratios will tend to reduce effective population size and bias selection estimates. PMID:27928001

  2. The Impact of male reproductive skew on kin structure and sociality in multi-male groups.

    PubMed

    Widdig, Anja

    2013-01-01

    Patterns of within-group relatedness are expected to affect the prospects for cooperation among group members through kin selection. It has long been established that dispersal patterns determine the availability of kin and there is ample evidence of matrilineal kin biases in social behavior across primate species. However, in 1979, Jeanne Altmann(1) suggested that mating patterns also influence the structure of within-group relatedness; high male reproductive skew and the frequent replacement of breeding males leads to relatively high levels of paternal relatedness and age-structured paternal sibships within groups. As a consequence of frequent replacement of breeding males, relatedness among offspring of a given female will be reduced to the half- rather than full-sibling level. Depending on the number of sires and degree of relatedness among mothers, members of the same birth cohort may be as closely related as maternal siblings. If animals are able to recognize their paternal kin and exhibit biases in favor of them, this may influence the distribution of cooperation and the intensity of competition within groups of primates. Here, I summarize the evidence that serves as the basis for Altmann's predictions and review evidence regarding whether or not the availability of paternal kin also leads to paternal kin bias among primates.

  3. Photoperiodicity in the male albino laboratory rat.

    PubMed

    Wallen, E P; Turek, F W

    1981-01-29

    Animals inhabiting areas where there are drastic changes in the environment often reproduce only during limited time periods to ensure that young are raised in optimal environmental conditions. The lack of a well defined breeding season in many domesticated animals, presumably because the selective pressures for seasonal breeding have been minimized, suggests that the neuroendocrine events controlling seasonal cyclicity have been bred out of these animals. Little is known about the underlying neuroendocrine changes which may occur during the evolution of a species from a seasonal to a nonseasonal breeder. Whereas the changing photoperiod is the primary environmental cue which initiates and/or terminates the reproductive season in many animals, this is not so in the albino rat Rattus norvegicus, a model nonseasonal breeder. Nevertheless, daylength can influence various reproductive parameters in laboratory rats, suggesting that some of the neuroendocrine components that controlled seasonal breeding previously are still extant in this species. To test this hypothesis, we investigated the effect of daylength on the responsiveness of the neuroendocrine--gonadal axis to the negative-feedback effects of testosterone. This paradigm was chosen because of the important role played by photic-induced changes in steroid feedback sensitivity in the control of seasonal reproduction. We report here that although daylength has very little effect on neuroendocrine--gonadal function in the intact male laboratory rat, it seems that some component(s) of a photoperiodic system involving the pineal gland has been preserved.

  4. Monocular sleep in male domestic chicks.

    PubMed

    Mascetti, Gian Gastone; Bobbo, Daniela; Rugger, Marina; Vallortigara, Giorgio

    2004-08-31

    Behavioural sleep during the first 2 weeks after hatching was studied in male chicks reared with an imprinting object (I-chicks) and in social isolation (NI-chicks). Time spent in sleeping with both eyes closed (binocular sleep) decreased gradually with age in both I-chicks and in NI-chicks whilst the number of episodes of binocular sleep decreased with age in NI-chicks but not in I-chicks. The pattern of monocular sleep (only one eye closed) of both I-chicks and NI-chicks showed no significant bias towards predominant left- or right-eye closure during the first week. During the second week, I-chicks showed a tendency towards more pronounced left-eye closure with a peak on day 10, whilst NI-chicks showed a tendency for more pronounced right-eye closure with peaks on days 9 and 11. In a different group of chicks, changing the colour of the imprinting object on day 8 produced a shift towards right-eye closure. In contrast, the removal of the imprinting object on day 8 did not cause any change in the pattern of monocular sleep. Differences with respect to sleeping patterns previously observed in females chicks are discussed.

  5. [Therapy of male fertility disorders with kallikrein].

    PubMed

    Schill, W B

    1976-11-26

    An overview of the use of kallikrein to treat male sterility is presented. Kallikrein was shown to increase sperm motility in both in vivo and in vitro studies. The vitality and longevity of the sperm are also enhanced. These effects are due to the stimulation of the intracellular concentration of cyclical adenosonemonophosphates in the sperm. Quinine receptors on the sperm surface are assumed to be the mechanism responsible for the kallikrein effect. Kallikrein stimulates spermal penetration of cervical mucus by about 80% and causes a significant increase in total sperm output 3 months from the beginning of treatment. After 2 months of use, kallikrein leads to an increase in the number of normally formed spermatozoa in the ejaculate. Kallikrein is indicated in cases of asthenospermia and oligozoospermia, in some cases of teratozoospermia, in cases of the vegetative-functional congestion syndrome desecribed by Hoffmann, and is recommended in cases of testicular parenchyme damage involving tubulus function. Parenteral administration involves 40 KE (1KE=8mcg) thrice weekly, oral administration 300-600 KE daily. Kallikrein is added directly to the ejaculate in instrumental insemination in cases of therapy-resistant decrease in motility associated with asthenospermia or oligozoospermia. Concentrations of 5 KE per ml ejaculate are used in such cases. Chronic infection, especially in the genital area, and the incidence of dizziness during therapy are contraindications to kellikrein use.

  6. Male Homosexual Preference: Where, When, Why?

    PubMed Central

    Barthes, Julien; Crochet, Pierre-André; Raymond, Michel

    2015-01-01

    Male homosexual preference (MHP) has long been of interest to scholars studying the evolution of human sexuality. Indeed, MHP is partially heritable, induces a reproductive cost and is common. MHP has thus been considered a Darwinian paradox. Several questions arise when MHP is considered in an evolutionary context. At what point did MHP appear in the human evolutionary history? Is MHP present in all human groups? How has MHP evolved, given that MHP is a reproductively costly trait? These questions were addressed here, using data from the anthropological and archaeological literature. Our detailed analysis of the available data challenges the common view of MHP being a “virtually universal” trait present in humans since prehistory. The conditions under which it is possible to affirm that MHP was present in past societies are discussed. Furthermore, using anthropological reports, the presence or absence of MHP was documented for 107 societies, allowing us to conclude that evidence of the absence of MHP is available for some societies. A recent evolutionary hypothesis has argued that social stratification together with hypergyny (the hypergyny hypothesis) are necessary conditions for the evolution of MHP. Here, the link between the level of stratification and the probability of observing MHP was tested using an unprecedented large dataset. Furthermore, the test was performed for the first time by controlling for the phylogenetic non-independence between societies. A positive relationship was observed between the level of social stratification and the probability of observing MHP, supporting the hypergyny hypothesis. PMID:26267276

  7. Oxytocin improves emotion recognition for older males.

    PubMed

    Campbell, Anna; Ruffman, Ted; Murray, Janice E; Glue, Paul

    2014-10-01

    Older adults (≥60 years) perform worse than young adults (18-30 years) when recognizing facial expressions of emotion. The hypothesized cause of these changes might be declines in neurotransmitters that could affect information processing within the brain. In the present study, we examined the neuropeptide oxytocin that functions to increase neurotransmission. Research suggests that oxytocin benefits the emotion recognition of less socially able individuals. Men tend to have lower levels of oxytocin and older men tend to have worse emotion recognition than older women; therefore, there is reason to think that older men will be particularly likely to benefit from oxytocin. We examined this idea using a double-blind design, testing 68 older and 68 young adults randomly allocated to receive oxytocin nasal spray (20 international units) or placebo. Forty-five minutes afterward they completed an emotion recognition task assessing labeling accuracy for angry, disgusted, fearful, happy, neutral, and sad faces. Older males receiving oxytocin showed improved emotion recognition relative to those taking placebo. No differences were found for older females or young adults. We hypothesize that oxytocin facilitates emotion recognition by improving neurotransmission in the group with the worst emotion recognition.

  8. Testicular Biopsy in Evaluation of Male Infertility

    PubMed Central

    Meinhard, Elizabeth; McRae, C. U.; Chisholm, G. D.

    1973-01-01

    Testicular biopsy findings in 100 infertile men were correlated with the clinical findings. Mild or moderately severe tubular lesions were seen in 57 cases and severe changes in 43. Clinical examination and semen analysis were no guide to the severity of the testicular lesion. Though patients with normal sized testes more commonly had mild tubular lesions, many were severe. Patients with small testes more often had severe lesions but some had only mild tubular changes. Biopsy findings in both aspermic and oligospermic patients ranged from normal to a complete loss of germinal tissue. Testicular biopsy is advocated in infertile men for the complete assessment of the case and for identifying those which are potentially treatable. Patients with a severe lesion can be spared further investigations. The choice and results of treatment are discussed, particularly the surgical treatment of varicocele or obstruction. Only patients with a mild or moderate testicular tubular lesion should participate in future trials with drugs for male infertility. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8FIG. 9FIG. 10 PMID:4726930

  9. [Male fertility after chemotherapy during childhood].

    PubMed

    Aubier, F; Patte, C; de Vathaire, F; Tournade, M F; Oberlin, O; Sakiroglu, O; Lemerle, J

    1995-01-01

    Chemotherapy has considerably improved the prognosis of solid tumours in children, but may have very adverse effects, particularly on fertility. A study was conducted at the Gustave Roussy Institute to identify the toxic effect of chemotherapy on male fertility. At present, 205 patients, treated during childhood have entered the study. Basal FSH-LH have been assayed to assess possible germ cell damage although azoosperia can not be eliminated. Results were normal in 127 patients (62%) and increased basal FSH levels were found in 78 (38%). Endocrine function was not altered: all patients were either impubertal or intrapubertal at diagnosis and subsequently achieved normal puberty. Multivariate analysis revealed an obvious toxic effect of 2 alkylating drugs: cyclophosphamide and procarbazine. No toxic effect was observed for vincristine, dohorubicin or actinomycin D. Age and pubertal status at diagnosis were not correlated with toxic effects. At present, no conclusion for other drugs may be made but results high dose metotrexate are promising. For lomustine and cisplatin, less favourable, though nonsignificant, results have been obtained. Complete recovery is possible several years later.

  10. Selenium in human male reproductive organs.

    PubMed

    Oldereid, N B; Thomassen, Y; Purvis, K

    1998-08-01

    The objective of the study was to obtain information on the concentration and distribution of selenium throughout the human male reproductive tract. Material was removed at autopsy from 41 men who had died suddenly and unexpectedly. Semen samples were also provided from 184 men attending an andrology clinic for fertility investigation and from 32 healthy volunteers. Significant positive correlations in the selenium concentration were demonstrated between the different reproductive organs, the testis having the highest concentrations. No correlation was found between the concentration of selenium in the genital organs and liver, kidney or blood, suggesting that its uptake and/or biochemical activity in the reproductive organs may be controlled by similar mechanisms not shared by the other organs. No significant age-dependent changes could be detected in tissue selenium concentrations. In a group of men under fertility investigation, a significant positive correlation was obtained between seminal plasma concentrations of selenium and concentrations of spermatozoa in the same ejaculate. A significant positive correlation between concentrations of zinc and selenium in the same ejaculates indicated that selenium may arise largely from the prostate gland.

  11. Syringocystadenoma papilliferum on the male nipple.

    PubMed

    Shindo, Masahisa; Yamada, Nanako; Yoshida, Yuichi; Yamamoto, Osamu; Morino, Shinichi

    2011-06-01

    Syringocystadenoma papilliferum is a rare benign adnexal tumor that most frequently arises from an organoid nevus on the head and neck. Occurrence of this tumor on the male breast is extremely rare. A 74-year-old Japanese man presented with a nodule on his left nipple. Histopathological findings were typical for syringocystadenoma papilliferum. Ultrastructurally, constituent epithelial cells of the tumor were divided into three types. We focused on one cell type, undifferentiated clear cells, which have been suggested to be pluripotent cells bearing stem cell nature in syringocystadenoma papilliferum. Immunohistochemically, the tumor cells were negative for cytokeratin 15, which is known as a relatively specific marker for multipotent stem cells in the follicular bulge. We speculated that the clear cells are slightly differentiated toward apocrine rather than stem cells. We also ruled out the possibility of a relationship between the clear cells and Toker cells, which have a clear cytoplasm and are present in the areola region. Dermoscopic examination revealed amorphous milky white areas that corresponded to the pathological findings of luminal deposition of the tumor.

  12. RISUG: An intravasal injectable male contraceptive

    PubMed Central

    Lohiya, N.K.; Alam, I.; Hussain, M.; Khan, S.R.; Ansari, A.S.

    2014-01-01

    Over the last two decades RISUG has been drawing attention in the field of male contraception. It promises to sterile men for a period of up to 10-15 years. According to recent studies in animal models, it proves to be completely reversible. Practically, there are no better options available that can assure complete sterility and precise reversibility. Regardless of so much of information available, RISUG is still holding up for many reasons, firstly, the available information engender bewilderment such as what is this copolymer, how does it work and is reversal really possible? Secondly, advancement of this outstanding invention is drastically slow and thirdly, effects of long-term contraception with RISUG and reports on evaluation of anomalies (if any) in F1, F2 progenies, are lacking. In this review the lacunae as well as advances in the development of RISUG in the light of published work and available resources are pointed out. Formulation of the RISUG, its mode of action and clinical trials have been addressed with particular emphasis. PMID:25673546

  13. Male fertility preservation before gonadotoxic therapies

    PubMed Central

    Wyns, C.

    2010-01-01

    Background: Recent advances in cancer therapy have resulted in an increased number of long-term cancer survivors. Unfortunately, aggressive chemotherapy, radiotherapy and preparative regimens for bone marrow transplantation can severely affect male germ cells, including spermatogonial stem cells (SSCs), and lead to permanent loss of fertility. Different options for fertility preservation are dependent on the pubertal state of the patient. Methods: Relevant studies were identified by an extensive Medline search of English and French language articles. Results: Sperm cryopreservation prior to gonadotoxic treatment is a well established method after puberty. In case of ejaculation failure by masturbation, assisted ejaculation methods or testicular tissue sampling should be considered. Although no effective gonadoprotective drug is yet available for in vivo spermatogonial stem cell (SSC) protection in humans, current evidence supports the feasibility of immature testicular tissue (ITT) cryopreservation. The different cryopreservation protocols and available fertility restoration options from frozen tissue, i.e. cell suspension transplantation, tissue grafting and in vitro maturation, are presented. Results obtained in humans are discussed in the light of lessons learned from animal studies. Conclusion: Advances in reproductive technology have made fertility preservation a real possibility in young patients whose gonadal function is threatened by gonadotoxic therapies. The putative indications for such techniques, as well as their limitations according to disease, are outlined. PMID:25302103

  14. On Sexual Apathy in the Male

    PubMed Central

    Greenson, Ralph R.

    1968-01-01

    Ever since World War II, there has been a noticeable change in the sexual behavior and responses in men and women. Women, in general, are becoming sexually more assertive and demanding and men more indifferent and lethargic. In patients of middle age, sexual boredom is particularly pronounced in men, whereas the post-menopausal female becomes more interested in sexual pleasure. In the youth of the “cool” generation, both boys and girls are quite open about sex, but their sexual activities precede emotional involvement. The similarities in dress and behavior of both sexes indicate a wish for a twin rather than a search for a lover. In the age group between 25 and 45, women demand equal orgasms since they have become economically independent and are relatively free of the fear of pregnancy. This seems to have mobilized a deep-seated unconscious fear and hatred of women in the male, making him sexually apathetic. In both sexes there is a growing alienation between romantic love and sex. PMID:5652746

  15. Stature estimation for Bosnian male population.

    PubMed

    Sarajlić, Nermin; Cihlarz, Zdenko; Klonowski, Eva Elvira; Selak, Ivan

    2006-02-01

    Since 1996, the Trotter and Gleser formulae to determine the stature of recovered missing persons in Bosnia and Herzegovina have been used. The purpose of this study is to develop appropriate stature estimation formulae from the length of the femur, tibia and fibula for use in the Bosnia and Herzegovina to help in identifications of the victims. Research was undertaken on 50 male cadavers, of individuals who died between the ages of 23 to 54 years. The cadaver length was measured and the length of the long bones was obtained from X-ray photographs. The length of the cadavers of the individuals who died after age of 45 years was corrected according to Giles' table. This study established that using Trotter and Gleser's formulae underestimate stature of tall people in the current population of Bosnia and Herzegovina. Smallest standard error of estimate is observed in the formula that uses the sum of the length of femur and fibula. There are no statistically significant differences between the length of the bones from the left and right sides of the body. Therefore, formulae developed from the average length of bone pairs are recommended for use.

  16. Epigenetic Remodeling in Male Germline Development

    PubMed Central

    Shen, Qiaoyan

    2016-01-01

    In mammals, germ cells guarantee the inheritance of genetic and epigenetic information across generations and are the origin of a new organism. During embryo development, the blastocyst is formed in the early stage, is comprised of an inner cell mass which is pluripotent, and could give rise to the embryonic stem cells (ESCs). The inner cell mass undergoes demethylation processes and will reestablish a methylated state that is similar to that of somatic cells later in epiblast stage. Primordial germ cells (PGCs) will be formed very soon and accompanied by the process of genome-wide demethylation. With the input of male sex determination genes, spermatogonial stem cells (SSCs) are generated and undergo the process of spermatogenesis. Spermatogenesis is a delicately regulated process in which various regulations are launched to guarantee normal mitosis and meiosis in SSCs. During all these processes, especially during spermatid development, DNA methylation profile and histone modifications are of crucial importance. In this review, we will discuss the epigenetic modifications from zygote formation to mature sperm generation and their significance to these development processes. PMID:27818689

  17. Cohort profile: the European Male Ageing Study.

    PubMed

    Lee, David M; Pye, Stephen R; Tajar, Abdelouahid; O'Neill, Terence W; Finn, Joseph D; Boonen, Steven; Bartfai, Gyorgy; Casanueva, Felipe F; Forti, Gianni; Giwercman, Aleksander; Han, Thang S; Huhtaniemi, Ilpo T; Kula, Krzysztof; Lean, Michael E J; Pendleton, Neil; Punab, Margus; Silman, Alan J; Vanderschueren, Dirk; Wu, Frederick C W

    2013-04-01

    The European Male Ageing Study (EMAS) was designed to examine the hypothesis that inter-individual and regional variability in symptomatic dysfunctions, alterations in body composition and health outcomes in ageing men can be explained by different rates of decline in anabolic hormones, the most important of which being testosterone. Between 2003 and 2005, 3369 community-dwelling men, aged between 40 and 79 years, were recruited from population-based registers in eight European centres to participate in the baseline survey, with follow-up investigations performed a median of 4.3 years later. Largely, identical questionnaire instruments and clinical investigations were used in both phases to capture contemporaneous data on general health (including cardiovascular diseases and chronic conditions), physical and cognitive functioning, mental health, sexual function, quality of life, bone health, chronic pain, disease biomarkers, hormones (sex hormones and metabolic hormones) and genetic polymorphisms. EMAS actively encourages new collaborations, data sharing for validation studies and participation in genetic study consortia. Potential collaborators should contact the principal investigator (F.C.W.W.) in the first instance.

  18. Costs influence male mate choice in a freshwater fish.

    PubMed Central

    Wong, Bob B M; Jennions, Michael D

    2003-01-01

    It is well known that female mate choice decisions depend on the direct costs of choosing (either because of search costs or male-imposed costs). Far less is known about how direct fitness costs affect male mate choice. We conducted an experiment to investigate male mate choice in a fish, the Pacific blue-eye (Pseudomugil signifer). Preferred females were larger, probably because larger females are also more fecund. Males, however, were consistent in their choice of female only when the costs of associating with prospective mates were equal. By contrast, males were far less consistent in their choice when made to swim against a current to remain with their initially preferred mate. Our results suggest that males may also respond adaptively to changes in the costs of choosing. PMID:12952630

  19. Female, but not male, nematodes evolve under experimental sexual coevolution

    PubMed Central

    Fritzsche, K.; Timmermeyer, N.; Wolter, M.; Michiels, N. K.

    2014-01-01

    Coevolution between the sexes is often considered to be male-driven: the male genome is constantly scanned by selection for traits that increase relative male fertilization success. Whenever these traits are harmful to females, the female genome is scanned for resistance traits. The resulting antagonistic coevolution between the sexes is analogous to Red Queen dynamics, where adaptation and counteradaptation keep each other in check. However, the underlying assumption that male trait evolution precedes female trait counteradaptation has received few empirical tests. Using the gonochoristic nematode Caenorhabditis remanei, we now show that 20 generations of relaxed versus increased sexual selection pressure lead to female, but not to male, trait evolution, questioning the generality of a male-driven process. PMID:25339719

  20. Male Reproductive Cancers and Infertility: A Mutual Relationship

    PubMed Central

    Tvrda, Eva; Agarwal, Ashok; Alkuhaimi, Nawaf

    2015-01-01

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

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

    PubMed

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

    2013-11-01

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

  2. Fishery induces sperm depletion and reduction in male reproductive potential for crab species under male-biased harvest strategy.

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  4. [Research progress on molecular genetics of male homosexuality].

    PubMed

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

    2016-08-01

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

  5. [Impact of cell phone radiation on male reproduction].

    PubMed

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

    2010-11-01

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

  6. Erotized Transference in the Male Patient–Female Therapist Dyad

    PubMed Central

    Koo, Martha B.

    2001-01-01

    Little has been published regarding male patients' erotic transferences to female therapists. It has been suggested that male patients do not develop full erotic transferences and rarely experience erotized transferences. The author presents a case report documenting erotization in a male patient–female therapist dyad and reviews current theories on the etiology, therapeutic significance, and treatment strategies indicated for such a transference. PMID:11121005

  7. Properties of maximum likelihood male fertility estimation in plant populations.

    PubMed Central

    Morgan, M T

    1998-01-01

    Computer simulations are used to evaluate maximum likelihood methods for inferring male fertility in plant populations. The maximum likelihood method can provide substantial power to characterize male fertilities at the population level. Results emphasize, however, the importance of adequate experimental design and evaluation of fertility estimates, as well as limitations to inference (e.g., about the variance in male fertility or the correlation between fertility and phenotypic trait value) that can be reasonably drawn. PMID:9611217

  8. Navy Job-Related Male-Female Differences: Annotated Bibliography.

    DTIC Science & Technology

    1982-04-01

    capacity and related measurements. Dyer, K. F. The trend of Lhe male-female performance differential in athletics , swimmning and cycling 1948-76. Journal of...cadets at USAF Academy are well above civilian conteinporaiies in physical fitness. 10. Top female athletes are gradually approaching male performance...differential in athletics , swimming and cycling 1948-76. Journal of Biosocial Science, 1977, 9, 325-338. Top male and female performances in track, swimming and

  9. High proportion of male faeces in jaguar populations.

    PubMed

    Palomares, Francisco; Roques, Séverine; Chávez, Cuauhtémoc; Silveira, Leandro; Keller, Claudia; Sollmann, Rahel; do Prado, Denise Mello; Torres, Patricia Carignano; Adrados, Begoña; Godoy, José Antonio; de Almeida Jácomo, Anah Tereza; Tôrres, Natália Mundim; Furtado, Mariana Malzoni; López-Bao, José Vicente

    2012-01-01

    Faeces provide relevant biological information which includes, with the application of genetic techniques, the sex and identity of individuals that defecated, thus providing potentially useful data on the behaviour and ecology of individuals, as well as the dynamics and structure of populations. This paper presents estimates of the sex ratio of different felid species (jaguar, Panthera onca; puma, Puma concolor; and ocelot/margay, Leopardus pardalis/Leopardus wiedi) as observed in field collected faeces, and proposes several hypotheses that could explain the strikingly high proportion of faeces from male jaguars. The proportion of male and female faeces was estimated using a non-invasive faecal sampling method in 14 study areas in Mexico and Brazil. Faecal samples were genetically analysed to identify the species, the sex and the individual (the latter only for samples identified as belonging to jaguars). Considering the three species, 72.6% of faeces (n = 493) were from males; however, there were significant differences among them, with the proportion from males being higher for jaguars than for pumas and ocelots/margays. A male-bias was consistently observed in all study areas for jaguar faeces, but not for the other species. For jaguars the trend was the same when considering the number of individuals identified (n = 68), with an average of 4.2±0.56 faeces per male and 2.0±0.36 per female. The observed faecal marking patterns might be related to the behaviour of female jaguars directed toward protecting litters from males, and in both male and female pumas, to prevent interspecific aggressions from male jaguars. The hypothesis that there are effectively more males than females in jaguar populations cannot be discarded, which could be due to the fact that females are territorial and males are not, or a tendency for males to disperse into suboptimal areas for the species.

  10. Females exceed males in mercury concentrations of burbot Lota lota

    USGS Publications Warehouse

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

    2015-01-01

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

  11. High Proportion of Male Faeces in Jaguar Populations

    PubMed Central

    Palomares, Francisco; Roques, Séverine; Chávez, Cuauhtémoc; Silveira, Leandro; Keller, Claudia; Sollmann, Rahel; do Prado, Denise Mello; Torres, Patricia Carignano; Adrados, Begoña; Godoy, José Antonio; de Almeida Jácomo, Anah Tereza; Tôrres, Natália Mundim; Furtado, Mariana Malzoni; López-Bao, José Vicente

    2012-01-01

    Faeces provide relevant biological information which includes, with the application of genetic techniques, the sex and identity of individuals that defecated, thus providing potentially useful data on the behaviour and ecology of individuals, as well as the dynamics and structure of populations. This paper presents estimates of the sex ratio of different felid species (jaguar, Panthera onca; puma, Puma concolor; and ocelot/margay, Leopardus pardalis/Leopardus wiedi) as observed in field collected faeces, and proposes several hypotheses that could explain the strikingly high proportion of faeces from male jaguars. The proportion of male and female faeces was estimated using a non-invasive faecal sampling method in 14 study areas in Mexico and Brazil. Faecal samples were genetically analysed to identify the species, the sex and the individual (the latter only for samples identified as belonging to jaguars). Considering the three species, 72.6% of faeces (n = 493) were from males; however, there were significant differences among them, with the proportion from males being higher for jaguars than for pumas and ocelots/margays. A male-bias was consistently observed in all study areas for jaguar faeces, but not for the other species. For jaguars the trend was the same when considering the number of individuals identified (n = 68), with an average of 4.2±0.56 faeces per male and 2.0±0.36 per female. The observed faecal marking patterns might be related to the behaviour of female jaguars directed toward protecting litters from males, and in both male and female pumas, to prevent interspecific aggressions from male jaguars. The hypothesis that there are effectively more males than females in jaguar populations cannot be discarded, which could be due to the fact that females are territorial and males are not, or a tendency for males to disperse into suboptimal areas for the species. PMID:23285226

  12. Sexual selection of male parental care in giant water bugs

    PubMed Central

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

    2016-01-01

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

  13. Cryptic female preference for colorful males in guppies.

    PubMed

    Pilastro, Andrea; Simonato, Martina; Bisazza, Angelo; Evans, Jonathan P

    2004-03-01

    Cryptic female choice (CFC) refers to female-mediated processes occurring during or after copulation that result in biased sperm use in favor of preferred or compatible males. Despite recent empirical support for this hypothesis, evidence that CFC contributes towards the evolution of male body ornaments, in the same way that precopulatory female choice does, is currently lacking. Here, we tested the possibility that CFC selects for increased male attractiveness in the guppy Poecilia reticulata, a freshwater fish exhibiting internal fertilization. Specifically, we examined whether females are able to manipulate the number of sperm transferred or retained at copulation in favor of relatively attractive males. In support of this prediction, we found that following solicited copulations the number of sperm inseminated is influenced exclusively by the female's perception of relative male coloration, independent of any direct manipulation of males themselves. Because females prefer brightly colored males during precopulatory mate choice, our finding that colorful males are also favored as a consequence of enhanced insemination success indicates that cryptic female choice can reinforce precopulatory preferences for extravagant male ornaments.

  14. Primary leiomyosarcoma of the male urethra: a case report

    PubMed Central

    2009-01-01

    Background Cancers of the male urethra constitute less than 1% of all malignant urological tumours, and the occurrence of sarcomas in the urethra is even less frequent. To our knowledge, only one case has been previously described in the English literature. Case presentation We report the clinical features, histology, imaging and treatment of urethral leiomyosarcoma in a male patient. Conclusion The occurrence of sarcoma in the urethra is most unusual, and its appearance as a primary growth in the male urethra is not recorded in the English literature. In conclusion, this case highlights a rare type of primary male urethral malignancy that features a poor prognosis. PMID:19946451

  15. Evidence for partial overlap of male olfactory cues in lampreys

    USGS Publications Warehouse

    Buchinger, Tyler J.; Li, Ke; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas S.

    2016-01-01

    Animals rely on a mosaic of complex information to find and evaluate mates. Pheromones, often comprised of multiple components, are considered to be particularly important for species-recognition in many species. While the evolution of species-specific pheromone blends is well-described in many insects, very few vertebrate pheromones have been studied in a macro-evolutionary context. Here, we report a phylogenetic comparison of multi-component male odours that guide reproduction in lampreys. Chemical profiling of sexually mature males from eleven species of lamprey, representing six of ten genera and two of three families, indicated the chemical profiles of sexually mature male odours are partially shared among species. Behavioural assays conducted with four species sympatric in the Laurentian Great Lakes indicated asymmetric female responses to heterospecific odours, where Petromyzon marinus were attracted to male odour collected from all species tested but other species generally preferred only the odour of conspecifics. Electro-olfactogram recordings from P. marinusindicated that although P. marinus exhibited behavioural responses to odours from males of all species, at least some of the compounds that elicited olfactory responses were different in conspecific male odours compared to heterospecific male odours. We conclude that some of the compounds released by sexually mature males are shared among species and elicit olfactory and behavioural responses in P. marinus, and suggest that our results provide evidence for partial overlap of male olfactory cues among lampreys. Further characterization of the chemical identities of odour components is needed to confirm shared pheromones among species.

  16. Spatial Ability Explains the Male Advantage in Approximate Arithmetic

    PubMed Central

    Wei, Wei; Chen, Chuansheng; Zhou, Xinlin

    2016-01-01

    Previous research has shown that females consistently outperform males in exact arithmetic, perhaps due to the former’s advantage in language processing. Much less is known about gender difference in approximate arithmetic. Given that approximate arithmetic is closely associated with visuospatial processing, which shows a male advantage we hypothesized that males would perform better than females in approximate arithmetic. In two experiments (496 children in Experiment 1 and 554 college students in Experiment 2), we found that males showed better performance in approximate arithmetic, which was accounted for by gender differences in spatial ability. PMID:27014124

  17. Energy requirements for growth in male and female Saanen goats.

    PubMed

    Almeida, A K; Resende, K T; St-Pierre, N; Silva, S P; Soares, D C; Fernandes, M H M R; Souza, A P; Silva, N C D; Lima, A R C; Teixeira, I A M A

    2015-08-01

    The aim of this study was to investigate the energy requirements of female and intact and castrated male Saanen goats. Animals were randomly assigned to 1 of 2 experiments designed to investigate the energy requirements for maintenance and gain. To determine the maintenance requirements, 85 goats were used (26 intact males, 30 castrated males, and 29 females) with an initial BW of 30.3 ± 0.87 kg. Thirty goats (8 intact males, 9 castrated males, and 13 females) were slaughtered to be used as the baseline group. The remaining goats were assigned in a split-plot design using a 3 × 3 factorial arrangement (3 sexes-intact males, castrated males, and females-and 3 DMI levels-ad libitum and restricted fed to 75 or 50% of the ad libitum intake). The NE was obtained using 65 goats (20 intact males, 22 castrated males, and 23 females) fed ad libitum in a completely randomized design. Eight intact males, 9 castrated males, and 13 females were slaughtered at 30.5 ± 1.53 kg BW. Seventeen goats (6 intact males, 6 castrated males, and 5 females) were slaughtered at 38.1 ± 0.49 kg BW. The remaining goats were slaughtered at 44.0 ± 0.50 kg BW. The NE did not differ between the sexes ( = 0.59; 258.5 kJ/kg BW), resulting in a ME for maintenance of 412.4 kJ/kg BW. The estimated energy use efficiency for maintenance was 0.627. During the growth phase, NE differed between the sexes ( < 0.001); intact males, castrated males, and females showed an average NE equal to 15.2, 18.6, and 22.7 MJ/kg of empty weight gain, respectively. The energy requirements for growth differed between the sexes. The difference was found to be due to distinct NE and partial efficiency of ME utilization for growth in intact and castrated males and females during the late growth phase. This study may contribute to adjustments in feeding system energy recommendations regarding the NE and NE found for goats during the late growth phase.

  18. [The function of ERα in male reproductive system].

    PubMed

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

    2014-12-01

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

  19. Infant Male Circumcision: Healthcare Provider Knowledge and Associated Factors

    PubMed Central

    Starzyk, Erin J.; Kelley, Michele A.; Caskey, Rachel N.; Schwartz, Alan; Kennelly, Joan F.; Bailey, Robert C.

    2015-01-01

    Background and Objectives The emerging science demonstrates various health benefits associated with infant male circumcision and adult male circumcision; yet rates are declining in the United States. The American Academy of Pediatrics and the Centers for Disease Control and Prevention recommend that healthcare providers present evidence-based risk and benefit information for infant male circumcision to parent(s) and guardian(s). The purpose of this study was to assess providers’ level of infant male circumcision knowledge and to identify the associated characteristics. Methods An online survey was administered to healthcare providers in the family medicine, obstetrics, and pediatrics medical specialties at an urban academic health center. To assess infant male circumcision knowledge, a 17 point summary score was constructed to identify level of provider knowledge within the survey. Results Ninety-two providers completed the survey. Providers scored high for the following knowledge items: adverse event rates, protects against phimosis and urinary tract infections, and does not prevent hypospadias. Providers scored lower for items related to more recent research: protection against cervical cancer, genital ulcer disease, bacterial vaginosis, and reduction in HIV acquisition. Two models were constructed looking at (1) overall knowledge about male circumcision, and (2) knowledge about male circumcision reduction in HIV acquisition. Pediatricians demonstrated greater overall infant male circumcision knowledge, while obstetricians exhibited significantly greater knowledge for the HIV acquisition item. Conclusion Providers’ knowledge levels regarding the risks and benefits of infant male circumcision are highly variable, indicating the need for system-based educational interventions. PMID:25635664

  20. Male brush-turkeys attempt sexual coercion in unusual circumstances.

    PubMed

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

    2014-07-01

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