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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Reproductive strategies in feral fowl, Gallus gallus

Pizzari, Tommaso 1999 (has links)
No description available.

Male adaptations to sperm competition in the sand martin Riparia riparia

Nicholls, E. Henry 2000 (has links)
No description available.

The Vocal Communication of Tibetan Macaques in Mt. Huangshan, China: their Vocal Repertoire, Call Functions, and Congeneric Comparisons in the Genus Macaca 中国の黄山におけるチベットモンキーの音声コミュニケーション:音声レパートリーおよび音声機能,マカク属内種間比較

Sofia, Kaliope Bernstein 24 November 2016 (has links)
付記する学位プログラム名: 霊長類学・ワイルドライフサイエンス・リーディング大学院 Kyoto University (京都大学) 0048 新制・課程博士 博士(理学) 甲第20045号 理博第4230号 新制||理||1609(附属図書館) 京都大学大学院理学研究科生物科学専攻 (主査)准教授 Michael Alan Huffman, 准教授 後藤 幸織, 教授 平井 啓久 学位規則第4条第1項該当

Reproductive physiology of the female cat : with special reference to cervical patency, sperm distribution and hysterography

Chatdarong, Kaywalee 2003 (has links) (PDF)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. Härtill 4 uppsatser.

Competition, coercion, and choice: The sex lives of female olive baboons (Papio anubis)

Walz, Jessica Terese, Walz 29 September 2016 (has links)
No description available.

Reprodukční chování slíďáků rodu Alopecosa (Araneae: Lycosidae) Reproductive behaviour of wolf spiders of the genus Alopecosa (Araneae: Lycosidae)

Just, Pavel 2015 (has links)
In my master's thesis, I deal with reproduction of central European wolf spiders of the genus Alopecosa. Here I present patterns and duration of courtship behaviour and copulation of 15 members of the genus Alopecosa. Such information were never published before. I recognized 17 courtship elements, six of them are described here for the first time. Duration of copulation, number of palpal insertions and number of hematodochal expansions of 15 species were examined. The obtained data were analyzed, courtship and copulations among species and species groups are discussed. Courtship behaviour of two sibling species, A. striatipes and A. mariae, is compared, as well as differences in reproduction of Czech and Italian populations of A. accentuata. Based on courtship behaviour, I propose placing Alopecosa psammophila in a striatipes group. Stridulatory apparatus on male pedipalps was not detected, however, some pegs on vetral side of the abdomen in males of Alopecosa pinteroum were found. These pegs could serve as a source of vibratory signals. The thesis provides some new remarks on ecology of members of the genus Alopecosa and contains faunistical information, including those on the recent occurrence of some of the rarest Czech spiders.

Comparative studies of the reproductive strategies of New Zealand grapsid crabs (Brachyura : Grapsidae) and the effects of parasites on their reproductive success

Brockerhoff, Annette Maria 2002 (has links)
The reproductive strategies of four intertidal grapsid crabs, Hemigrapsus sexdentatus, H. crenulatus, Cyclograpsus lavauxi, and Helice cressa, were studied in the field and laboratory, with emphasis on mating behaviour, duration of female receptivity, and sperm competition. Mating occurred in all species during the intermoult on the days prior to oviposition, when the gonoporo opercula of females became temporarily mobile. Female Helice crassa mated up to three weeks after oviposition, but in all other species mating typically ceased at egg-laying. Male Hemigrapsus pp. used a female-centered competition strategy in which they searched for and defended receptive females until they laid eggs. In contrast, male C. lavauxi searched for and intercepted receptive females only for the duration of copulation and then pursued other receptive females (a mating system termed encounter rate competition with pure search and interception). Male Helice crassa searched for receptive females in their immediate neighbourhood and mated with them briefly on the substrate or in the burrow after which the female left (a mating system termed encounter rate competition with neighbourhoods of dominance). The mating season was short and highly synchronous for Hemigrapsus exdentatus and Cyclograpsus lavauxi and asynchronous for Hemigrapsus crenulatus and Helice crassa. In the laboratory, the mean duration of receptivity for females housed with three males varied between 4.1 and 12.4 days, and the copulation frequency of females varied before oviposition between 2.1 and 24.3 times (mean) depending on the species. Female Hemigrapsus spp. isolated from males stayed receptive significantly longer than females held continuously with males. This suggests that females are able to control the duration of their receptivity, and therefore the time available for mating, according to the absence or presence of males. The operational sex ratio (OSR) had no effect on the duration of female receptivity, but female Hemigrapsus crenulatus mated more often when several males were competing for access. Therefore, male-male competition increased the number of matings per female and hence sperm competition within the female spermathecae. Larger males mated significantly more often than smaller males in all species. However, male size did not affect ejaculate size, meaning that small and large males transferred similar-sized ejaculates, e.g., in Hemigrapsus spp. Males of the two Hemigrapsus species followed a different strategy of sperm allocation. Male H. crenulatus, which are typically confronted with a high mating frequency of the female and a long, asynchronous mating season, distributed similar-sized ejaculates, irrespective of female size. By contrast, male H. sexdentatus, which experience a comparatively lower risk of sperm competition during a short, synchronised mating season, invested larger ejaculates for larger females than for smaller females. In addition, the size of the first and second ejaculates transferred to a female by a male H. crenulatus were not significantly different, whereas the first was larger than the second for H. sexdentatus. A parasitological survey was undertaken of the four grapsid crabs and the presence, seasonal variation and relationship with host gender and size of parasites determined. Four internal parasites were discovered: Nectonema zealandica n. Sp. (Nematomorpha: Nectonematoidea), portunion sp. (Isopoda: Entoniscidae), Profilicollis novaezelandensis n. sp. and profilicollis antarcticus (Acanthocephala: P olymorphidae). Portunion sp. castrated its female hosts, but not the males thereby creating a more male-biased sex ratio. Males parasitised with portunion sp. were equally successful during male-male competition and the number of matings they achieved. The above findings are important for our current understanding of mating strategies in Grapsidae, which are more diverse than previously thought. Females with a restricted duration of sexual receptivity have some control over their receptive period and can therefore influence the OSR and the extent of male-male competition. As females mated multiple times during their receptive period, sperm competition is a common feature in Grapsidae. However, males employed different tactics in regards to sperm competition such as longer mating duration (e.g., C. lavauxi), high number of matings (Helice crassa), or post-copulatory mate guarding until oviposition (Hemigrapsus spp.).

Dissociated Functional Pathways for Appetitive and Consummatory Reproductive Behaviors in Male Syrian Hamsters (Mesocricetus auratus)

Been, Laura E 21 November 2011 (has links)
In many species, including Syrian hamsters, male reproductive behavior depends on the perception of odor cues from conspecifics in the environment. Volatile odor cues are processed primarily by the main olfactory system, whereas non-volatile cues are processed primarily by the accessory olfactory system. Together, these two chemosensory systems mediate appetitive reproductive behaviors, such as attraction to female odors, and consummatory reproductive behaviors, such as copulation, in male Syrian hamsters. Main and accessory olfactory information are first integrated in the medial amygdala (MA), a limbic nucleus that is critical for the expression of reproductive behaviors. MA is densely interconnected with other ventral forebrain nuclei that receive chemosensory information and are sensitive to steroid hormones. Specifically, several lines of evidence suggest that MA may generate behavioral responses to socio-sexual odors via functional connections with the posterior bed nucleus of the stria terminalis (BNST) and medial preoptic area (MPOA). It is unknown, however, how these three nuclei act as functional circuit to adaptively regulate appetitive and consummatory reproductive behaviors. Therefore, the overarching goal of this dissertation was to determine how BNST and MPOA function, both uniquely and as a circuit with MA, to generate attraction to female odors and copulatory behaviors in male Syrian hamsters. We found that BNST is required for attraction to female odors, but not for copulation, in sexually-naïve males. In contrast, MPOA is required for both attraction to female odors and for copulation in sexually-naïve males. Surprisingly, prior sexual experience mitigated the requirement of BNST and MPOA for these behaviors. Next, we found that MA preferentially transmits female odor information to BNST and to MPOA, whereas BNST relays female and male odor information equivalently to MPOA. Finally, we found that the functional connections between MA and BNST are required for attraction to female odors but not for copulation, whereas the functional connections between MA and MPOA are required for copulation but not for attraction to female odors. Ultimately, these data may uncover a fundamental mechanism by which this ventral forebrain circuit regulates appetitive and consummatory reproductive behaviors across many species and modalities.

Mechanisms of reproductive interference in seed beetles: experimental tests of alternative hypotheses マメゾウムシ2種における繁殖干渉の機構:対立仮説の実験的検証

Kyogoku, Daisuke 23 March 2015 (has links)
Kyoto University (京都大学) 0048 新制・課程博士 博士(理学) 甲第18826号 理博第4084号 新制||理||1587(附属図書館) 31777 京都大学大学院理学研究科生物科学専攻 (主査)教授 曽田 貞滋, 准教授 渡辺 勝敏, 教授 高橋 淑子 学位規則第4条第1項該当

Association between perceived social support and induced abortion: A study in maternal health centers in Lima, Peru

Sánchez-Siancas, Luis E., Rodríguez-Medina, Angélica, Piscoya, Alejandro, Bernabe-Ortiz, Antonio 12 April 2018 (has links)
Objectives This study aimed to assess the association between perceived social support and induced abortion among young women in Lima, Peru. In addition, prevalence and incidence of induced abortion was estimated. Methods/Principal findings A cross-sectional study enrolling women aged 18–25 years from maternal health centers in Southern Lima, Peru, was conducted. Induced abortion was defined as the difference between the total number of pregnancies ended in abortion and the number of spontaneous abortions; whereas perceived social support was assessed using the DUKE-UNC scale. Prevalence and incidence of induced abortion (per 100 person-years risk) was estimated, and the association of interest was evaluated using Poisson regression models with robust variance. A total of 298 women were enrolled, mean age 21.7 (± 2.2) years. Low levels of social support were found in 43.6% (95%CI 38.0%–49.3%), and 17.4% (95%CI: 13.1%–21.8%) women reported at least one induced abortion. The incidence of induced abortion was 2.37 (95%CI: 1.81–3.11) per 100 person-years risk. The multivariable model showed evidence of the association between low perceived social support and induced abortion (RR = 1.94; 95%CI: 1.14–3.30) after controlling for confounders. Conclusions There was evidence of an association between low perceived social support and induced abortion among women aged 18 to 25 years. Incidence of induced abortion was similar or even greater than rates of countries where abortion is legal. Strategies to increase social support and reduce induced abortion rates are needed.

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