977 resultados para Male Sperm Priority


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The aim of this study was to determine the effect of long-term cryopreservation on physiological characteristics, the antioxidant activities and lipid peroxidation of red seabream sperm which were respectively cryopreserved with 15% dimethylsulfoxide (Me2SO) for 1 month, 13 months, 26 months, 48 months and 73 months. The motility and fertility of post-thaw sperm decreased with the storage time going on. The highest motility (87.67 +/- 2.52%) was obtained in sperm cryopreserved for 1 month and the lowest (50.67 +/- 5.31%) was in sperm for 73 months. There were no significant differences (p < 0.05) in fertilization rates of sperm cryopreserved for 1 month (71.33 +/- 8.84%), 13 months (69.22 +/- 1.02%) and 26 months (60.33 +/- 2.33%); however, the sperm fertility decreased significantly for 48 months (47.22 +/- 3.89%) and 73 months (39.56 +/- 0.69%) storage. In addition, superoxide dismutase (SOD) activities of sperm were at a stable level for less than 26 months storage, then, decreased significantly after 48 months storage. Catalase (CAT) activities of sperm cryopreserved for 13 months, 26 months, 48 months and 73 months were significantly lower than that for 1 month. There were no significant differences in the malondialdehyde (MDA) level of sperm for less than 13 months storage. After 26 months storage, the concentration of MDA increased significantly, and the highest concentration (3.22 +/- 0.05 nmol/mgprot) was obtained in 73 months storage sperm. (C) 2010 Elsevier Inc. All rights reserved.

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A nnual changes of the rep roduct ive act ivity in adult male p lateau p ika (Ochotona curzoniae) , a small endemic mammal in Q inghai2T ibet P lateau, w ere invest igated from J anuary to December, 1991. A ll of the animals w ere k illed and decap itated during the nigh t (23:00~ 24:00) and the p lasma, p ineal glands, testes ep ididym is, sem inal vesicles, deferent ducts were co llected and used for biochemical, and histo logical studies. Significant changes associated with seasonal cycles were found. (1) In February~ early April, the restoration phase, the weights of testes, epididym ides and deferent ducts were increased; the process of sperm atogenesis was strengthened and testo sterone level in plasma was increased, but the pineal weight and its melatonin content were decreased. (2) During the middle of April~ late May, the sexually active phase, a significant elevation of gonadal activity was observed. In this period, gonadalw eights were increased, spermatogenesis was completed, pineal weights were decreased and melatonin contents were fluctuated at alow level. These results suggested the increasing in sexual activity as well as in the ability of testo sterone secretion. (3) A striking reduction of test icular activity appears in June~A ugust. In this inhibition phase, gonada lweight, process of sperm atogenesis, plasma testo sterone level were decreased while the pineal weight and pineal melatonin content were increased. (4) During Sep tember~ J anuary, the sexually quiescent phase, declining in weights of testes and epididymides, arrest of spermatogenesis, decreasing of plasma testo sterone concent ration, fluctuating in pineal weights and increasing in pinealmelatonin level were observed. Our findings indicated that the male pikas under natural conditions exhibited an annual rep roductive cycle. A possible relationship between pineal activity and reproductive function was also suggested.

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We examined breeding behavior responses of male root votes (Microtus oeconomus) to temporal risk of predation by using acute and chronic exposure to predator odor. The 2 series of exposure experiments provided 2 types of temporal patterns of risk: continuous safety with a brief period of risk and Sustained risk with a brief period of safety. Male root votes that were acutely exposed to predator odor for I h suppressed their breeding behavior, but bred immediately after exposure to control odor for I h. Those chronically exposed to predator odor for 20 days maintained behavioral suppression during the 1-h period of exposure to control odor. Acutely exposed males did not change their physiological patterns of breeding, but those chronically exposed to predator odor had reduced testosterone concentration and epididymis index. Our results indicate that breeding behavior in a given situation depends on the overall patterns of risk experienced by male root votes, and the acute and chronic stress responses that affect reproduction are responsible for different behavioral responses to the 2 types of temporal patterns of risk. We also discuss the reasons for conflicting results about breeding suppression of votes between previous studies in the laboratory and the field.

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O selénio (Se) é um micronutriente essencial para o crescimento, desenvolvimento e normal metabolismo dos animais, incluindo o ser humano. É parte integrante de um conjunto de proteínas, as selenoproteínas, com ação antioxidante (protegendo as membranas celulares contra danos dos radicais livres), envolvidas no metabolismo das hormonas da tiróide, na regulação do crescimento e viabilidade celular, nas funções do sistema imune e na reprodução. É introduzido na dieta alimentar (principalmente nas formas de selenometionina e selenocisteína) através das plantas, e de produtos que delas derivam, que assimilam os compostos de selénio presentes no solo. Uma vez que a quantidade de selénio existente nos solos é muito variável, o teor nos alimentos vai depender da sua origem geográfica e, por consequência, a ingestão de selénio varia entre regiões e países. Baixos níveis de selénio estão associados a um declínio na função imune e problemas cognitivos. A deficiência de Se pode também ocasionar problemas musculares e cardiomiopatia. Concentrações reduzidas foram observadas em indíviduos com crises epiléticas e também em casos de pré-eclampsia. A deficiência de selénio pode também desenvolver-se durante a nutrição parenteral. Atualmente, a Dose Diária Recomendada (DDR) é de 55 μg/dia para homens e mulheres adultos e saudáveis. No entanto, existem evidências clínicas de que a ingestão em doses superiores (200-300 μg/dia) pode ter um papel benéfico na prevenção de alguns tipos de cancro e doenças cardiovasculares, na melhoria da resposta imunológica, como neuroprotetor e na fertilidade. O Se desempenha um papel importante na fertilidade masculina, sendo necessário na biossíntese da testosterona e na formação e normal desenvolvimento dos espermatozóides. Em mulheres grávidas o Se, ajuda a prevenir complicações antes e durante o parto e promove o normal desenvolvimento do feto. Como antioxidante o selénio vai combater os danos provocados pelos radicais livres, impedindo que estes exerçam o seu papel prejudicial no organismo. Sendo o sistema imunológico muito suscetível aos danos provocados pelo stress oxidativo, o Se vai exercer efeitos benéficos combatendo os danos por ele causados. Relativamente à capacidade viral, não é possível saber com exatidão qual a quantidade de Se necessária ou concentração ideal no plasma para evitar a ocorrência e desenvolvimento de infeções virais. No entanto, sabe-se que tem um efeito benéfico em pacientes HIV positivos e em indivíduos infetados com o vírus da hepatite (B ou C) contra a progressão para o neoplasia de fígado. Em teoria, a nível cardiovascular, este elemento pode exercer um efeito protetor, embora alguns estudos epidemiológicos não tenham mostrado uma associação clara entre o risco cardiovascular e os níveis selénio. A nível cerebral o Se vai atuar como neuroprotetor, prevenindo o aparecimento de patologias como demência e doença de Alzheimer. Apesar destes indicadores, a maioria dos países europeus, incluindo Portugal, regista uma deficiente ingestão de selénio por parte da população. A suplementação poderá constituir uma opção para garantir os níveis nutricionais recomendados e/ou ser utilizada com o objetivo de prevenir algumas doenças e o envelhecimento. No entanto o selénio pode também ser tóxico se ingerido em excesso, estando a dose máxima admissível fixada em 400 μg/dia. A intoxicação por selénio é chamada selenose e os sintomas comuns incluem: hálito a alho, distúrbios gastrointestinais, perda de cabelo, descamação das unhas, danos neurológicos e fadiga. Assim, atualmente acredita-se que enquanto indivíduos com baixo nível de Se podem obter benefícios da suplementação, esta pode ser prejudicial aqueles com valores normais ou elevados.

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We consider the general problem of synchronizing the data on two devices using a minimum amount of communication, a core infrastructural requirement for a large variety of distributed systems. Our approach considers the interactive synchronization of prioritized data, where, for example, certain information is more time-sensitive than other information. We propose and analyze a new scheme for efficient priority-based synchronization, which promises benefits over conventional synchronization.

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At Vita Columbae VC 2.17, Adomnán has severely misunderstood a written source which originally described how Columba ordered one party to a dispute, an alleged maleficus ‘evil-doer’ called Silnán, to milk a sick cow in order to settle the dispute by demonstrating that its contaminated milk was the real, hidden cause of the harm which had occasioned the dispute. Adomnán misread a description of a bos maculosus ‘pock-marked bovine’ to refer to a bos masculus ‘male bovine’, and proceeded to misunderstand the story as the description of some form of contest between Columba and a maleficus ‘sorcerer’.

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Background: Irritable bowel syndrome (IBS) is a common disorder that affects 10–15% of the population. Although characterised by a lack of reliable biological markers, the disease state is increasingly viewed as a disorder of the brain-gut axis. In particular, accumulating evidence points to the involvement of both the central and peripheral serotonergic systems in disease symptomatology. Furthermore, altered tryptophan metabolism and indoleamine 2,3-dioxygenase (IDO) activity are hallmarks of many stress-related disorders. The kynurenine pathway of tryptophan degradation may serve to link these findings to the low level immune activation recently described in IBS. In this study, we investigated tryptophan degradation in a male IBS cohort (n = 10) and control subjects (n = 26). Methods: Plasma samples were obtained from patients and healthy controls. Tryptophan and its metabolites were measured by high performance liquid chromatography (HPLC) and neopterin, a sensitive marker of immune activation, was measured using a commercially available ELISA assay. Results: Both kynurenine levels and the kynurenine:tryptophan ratio were significantly increased in the IBS cohort compared with healthy controls. Neopterin was also increased in the IBS subjects and the concentration of the neuroprotective metabolite kynurenic acid was decreased, as was the kynurenic acid:kynurenine ratio. Conclusion: These findings suggest that the activity of IDO, the immunoresponsive enzyme which is responsible for the degradation of tryptophan along this pathway, is enhanced in IBS patients relative to controls. This study provides novel evidence for an immune-mediated degradation of tryptophan in a male IBS population and identifies the kynurenine pathway as a potential source of biomarkers in this debilitating condition.

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The origin of eusociality in haplo-diploid organisms such as Hymenoptera has been mostly explained by kin selection. However, several studies have uncovered decreased relatedness values within colonies, resulting primarily from multiple queen matings (polyandry) and/or from the presence of more than one functional queen (polygyny). Here, we report on the use of microsatellite data for the investigation of sociogenetic parameters, such as relatedness, and levels of polygyny and polyandry, in the ant Pheidole pallidula. We demonstrate, through analysis of mother-offspring combinations and the use of direct sperm typing, that each queen is inseminated by a single male. The inbreeding coefficient within colonies and the levels of relatedness between the queens and their mate are not significantly different from zero, indicating that matings occur between unrelated individuals. Analyses of worker genotypes demonstrate that 38% of the colonies are polygynous with 2-4 functional queens, and suggest the existence of reproductive skew, i.e. unequal respective contribution of queens to reproduction. Finally, our analyses indicate that colonies are genetically differentiated and form a population exhibiting significant isolation-by-distance, suggesting that some colonies originate through budding.

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OBJECTIVE: This study compared self-reported subjective life expectancy (i.e., probability of living to age 75) for normal-weight, overweight, and obese weight groups to examine whether individuals are internalizing information about the health risks due to excessive weight. RESEARCH METHODS AND PROCEDURES: Using data from the Health and Retirement Study, a total of 9035 individuals 51 to 61 years old were analyzed by BMI category. The primary outcome measure was individuals' reports about their own expectations of survival to age 75. Absolute and relative risks of survival were compared with published estimates of survival to age 75. RESULTS: Consistently, higher levels of BMI were associated with lower self-estimated survival probabilities. Differences relative to normal weight ranged from 4.9% (p < 0.01) for male nonsmokers to 8.8% (p < 0.001) for female nonsmokers. However, these differences were substantially less than those obtained from published survival curve estimates, suggesting that obese individuals tended to underestimate mortality risks. DISCUSSION: Individuals appeared to underestimate the mortality risks of excessive weight; thus, knowledge campaigns about the risks of obesity should remain a top priority.

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Calorie restriction (CR) has been established as the only non-genetic method of altering longevity and attenuating biological changes associated with aging. This nutritional paradigm has been effective in nematodes, flies, rodents, dogs and possibly non-human primates. Its long history notwithstanding, little is known regarding the exact mechanism(s) of CR action or its potential impact on the hypothalamic-pituitary-gonadal (HPG) axis. The objectives of this project were to: 1) analyze neuroendocrine changes to the HPG axis that occur with aging and 2) evaluate the effects of moderate CR on reproductive function in male rhesus macaques. Pituitary gene expression profiling, semi-quantitative RT-PCR (sqRT-PCR) and immunohistochemistry showed circadian clock mechanism components present in three age categories of macaques, demonstrated age differences in expression for Per2, indicated differential expression of Per2 and Bmal1 at opposing time points and revealed daily rhythmic expression of REV-ERBα protein. These data indicate the ability of the macaque pituitary to express core-clock genes, their protein products, and to do so in a 24-hour rhythm. Young Adult CON and CR pituitary gene expression profiles detected potential differential expression in <150 probesets. A decline in>TSHR and CGA was detected in CR macaques as measured by sqRT-PCR. Other genes investigated showed no diet-induced changes. Young Adult CON and CR testicular gene expression profiles detected potential differential expression in <300 probesets although mRNA expression was not altered based on sqRT-PCR and real-time RT-PCR. Age-related>and/or diet-induced changes in HSD17β3, INSL3, CSNK1E and CGA were observed in a separate experiment with CGA in Old Adult CR subjects returning to youthful levels. Semen samples were collected from Young Adult CON and CR macaques. Normal spermiogram measures, ZP-binding, AR assay and SCSA® were conducted and indicated no differences between CON and CR-treated animals. Both groups exhibited similar daily testosterone profiles with no differences in mean or maximum levels; however, daily minimum testosterone levels were lower in CON animals. It appears that moderate CR had limited impact on neuroendocrine or reproductive function in male rhesus macaques based on our selected endpoints. Thus, advantageous CR health benefits can be achieved without obvious negative consequences to the HPG axis.

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The Bateson-Dobzhansky-Muller model posits that hybrid incompatibilities result from genetic changes that accumulate during population divergence. Indeed, much effort in recent years has been devoted to identifying genes associated with hybrid incompatibilities, often with limited success, suggesting that hybrid sterility and inviability are frequently caused by complex interactions between multiple loci and not by single or a small number of gene pairs. Our previous study showed that the nature of epistasis between sterility-conferring QTL in the Drosophila persimilis-D. pseudoobscura bogotana species pair is highly specific. Here, we further dissect one of the three QTL underlying hybrid male sterility between these species and provide evidence for multiple factors within this QTL. This result indicates that the number of loci thought to contribute to hybrid dysfunction may have been underestimated, and we discuss how linkage and complex epistasis may be characteristic of the genetics of hybrid incompatibilities. We further pinpoint the location of one locus that confers hybrid male sterility when homozygous, dubbed "mule-like", to roughly 250 kilobases.

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Males of many insect species feed their partner during courtship and mating. Studies of male nutrient donation in various systems have established that nuptial feeding has evolved mostly through sexual selection. Although there is extensive diversity in form, the function of nuptial gifts is typically limited to either facilitating copulation or increasing ejaculate transfer, depending on the time at which the gift is consumed by females. Unlike other insects, the Hawaiian swordtail cricket Laupala (Gryllidae: Trigonidiinae) exhibits serial transfer of nuptial gifts. Males transfer multiple spermless 'micro' spermatophores over several hours before mating at the end of the day (i.e. before the transfer of a single sperm-containing 'macro' spermatophore). By experimental manipulation of male microspermatophore donation, I tested several hypotheses pertaining to the adaptive significance of nuptial gifts in this system. I found that microspermatophore transfer improves insemination, by causing the female reproductive tract to take in more sperm. This result reveals a previously undocumented function for premating nuptial gift donation among insects. Enhanced sperm transfer due to microspermatophore donation may represent male manipulation or an internal mechanism of post-copulatory choice by females. I also performed experimental manipulation of male photoperiod to investigate how time and gender influence nuptial gift production and mating behavior. I found that the timing of mating is limited in males but not females and that the time of pair formation has consequences for the degree of nuptial gift donation, which suggests that both mating timing and microspermatophore number is important for male reproductive success. Finally, I observed the mating behavior of several trigonidiine taxa for a comparative analysis of sexual behavior and found that other genera also utilize spermless microspermatophores, which suggests that microspermatophore donation may be a common nuptial gift strategy among swordtail crickets. The elaborate nuptial feeding behavior of Hawaiian swordtail crickets prior to mating represents a newly discovered strategy to increase male insemination success rather than mating success. Based on this unexpected result, it is worth exploring whether courtship behaviors in other cricket or insect mating systems have also evolved to increase sperm uptake.

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As part of a long-term study on howling monkey behavior and social dynamics, a known natal male was observed taking over his group from his putative sire. Due to the accidental death of one of the adult males, this natal male had matured in a one-male group and had never observed juvenile male emigration nor adult male immigration and associated behaviors. Nevertheless, the behaviors associated with the takeover were indistinguishable from those of an immigrant male, including disappearance of immatures, one of whom was found with extensive injuries. While it cannot be said that the natal male inherited these behaviors from his presumed father, it can be said that he exhibited species-typical behaviors associated with male takeover in the absence of observational learning. © 1994 Japan Monkey Centre.

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The aggression animals receive from conspecifics varies between individuals across their lifetime. As poignantly evidenced by infanticide, for example, aggression can have dramatic fitness consequences. Nevertheless, we understand little about the sources of variation in received aggression, particularly in females. Using a female-dominant species renowned for aggressivity in both sexes, we tested for potential social, demographic, and genetic patterns in the frequency with which animals were wounded by conspecifics. Our study included 243 captive, ring-tailed lemurs (Lemur catta), followed from infancy to adulthood over a 35-year time span. We extracted injury, social, and life-history information from colony records and calculated neutral heterozygosity for a subset of animals, as an estimate of genetic diversity. Focusing on victims rather than aggressors, we used General Linear Models to explain bite-wound patterns at different life stages. In infancy, maternal age best predicted wounds received, as infants born to young mothers were the most frequent infanticide victims. In adulthood, sex best predicted wounds received, as males were three times more likely than females to be seriously injured. No relation emerged between wounds received and the other variables studied. Beyond the generally expected costs of adult male intrasexual aggression, we suggest possible additive costs associated with female-dominant societies - those suffered by young mothers engaged in aggressive disputes and those suffered by adult males aggressively targeted by both sexes. We propose that infanticide in lemurs may be a costly by-product of aggressively mediated, female social dominance. Accordingly, the benefits of female behavioral 'masculinization' accrued to females through priority of access to resources, may be partially offset by early costs in reproductive success. Understanding the factors that influence lifetime patterns of conspecific wounding is critical to evaluating the fitness costs associated with social living; however, these costs may vary substantially between societies.

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PURPOSE/BACKGROUND: Dynamic balance is an important component of motor skill development. Poor dynamic balance has previously been associated with sport related injury. However, the vast majority of dynamic balance studies as they relate to sport injury have occurred in developed North American or European countries. Thus, the purpose of this study was to compare dynamic balance in adolescent male soccer players from Rwanda to a matched group from the United States. METHODS: Twenty-six adolescent male soccer players from Rwanda and 26 age- and gender-matched control subjects from the United States were screened using the Lower Quarter Y Balance Test during their pre-participation physical. Reach asymmetry (cm) between limbs was examined for all reach directions. In addition, reach distance in each direction (normalized to limb length, %LL) and the composite reach score (also normalized to %LL) were examined. Dependent samples t-tests were performed with significant differences identified at p<0.05. RESULTS: Twenty-six male soccer players from Rwanda (R) were matched to twenty-six male soccer players from the United States (US). The Rwandan soccer players performed better in the anterior (R: 83.9 ± 3.2 %LL; US: 76.5 ± 6.6 %LL, p<0.01), posterolateral (R: 114.4 ± 8.3 %LL ; US: 106.5 ± 8.2 %LL, p<0.01) and composite (R: 105.6 ± 1.3 %LL; US: 97.8 ± 6.2 %LL, p<0.01) reach scores. No significant differences between groups were observed for reach asymmetry. CONCLUSIONS: Adolescent soccer players from Rwanda exhibit superior performance on a standardized dynamic balance test as comparison to similar athletes from the United States. The examination of movement abilities of athletes from countries of various origins may allow for a greater understanding of the range of true normative values for dynamic balance. LEVELS OF EVIDENCE: 3b.