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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.
11

Spatial differentials in fertility and the 0-6 year sex ratio in India by district, 2001 /

McIlwain, Amber Shevaun, January 1900 (has links)
Thesis (M.S.)--Texas State University-San Marcos, 2007. / Vita. Includes bibliographical references (leaves 56-59).
12

Identifying mating systems of imperiled marine turtles nesting in southern Florida through exclusion analysis to estimate the breeding sex ratio

Unknown Date (has links)
The reproductive behavior of migratory organisms is difficult to characterize as the mating behavior can be difficult to observe. For some species, one sex can be readily observable, but the other may remain hidden, confounding attempts to assess population demographics. For such species, it can be difficult to determine the sex ratio of the population. Without accurate accounts of the numbers of males and females, conservation methods may be insufficient and their performance unclear. Alternative methods of measuring sex ratios therefore must be used to estimate the number of individuals and assess breeding behavior. Here I identified breeding sex ratios (BSR) measured using paternity analysis of offspring through exclusion analysis to quantify the numbers of males contributing. Here I discuss the mating behavior of three species of marine turtle that nest in southern Florida: the loggerhead (Caretta caretta), the leatherback (Dermochelys coriacea), and the green sea turtle (Chelonia mydas) at three beaches (Boca Raton, Juno Beach, and Sanibel Island) from 2013-2017; over 400 nesting females were identified and genotyped and almost 7,000 hatchlings were collected and genotyped. Females from all three species successfully mated with more than one male in all years analyzed demonstrating multiple paternity of clutches. For loggerheads, many male genotypes were identified, suggesting that females likely mate en route to their nesting grounds, inducing a male-biased BSR. Examination of females that were sampled more than once per season (repeats), evidence of sperm storage was found for all nests and some turtles might mate in between nesting events. Leatherback females displayed a higher rate of multiple paternity than was previously published for other Caribbean nesting sites; I hypothesize that this result may be due to a mainland nesting beach effect. The leatherback BSR over all years was approximately 1:1, and one male was identified fathering than two different females’ nests (polygyny). For green turtles, multiple paternity was found and there was evidence of polygyny. Across all three species, evidence for indirect benefits of mating multiply (hatching success or larger hatchlings) was weak or not supported. Together, the four studies contribute to the overall body of reproductive behavior studies. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
13

A study of the sex ratio and fin morphometry of the Thai medaka, Oryzias minutillus, inhabiting suburbs of Bangkok, Thailand

Ngamniyom, Arin, Magtoon, Wichian, Nagahama, Yoshitaka, Sasayama, Yuichi January 2007 (has links)
No description available.
14

THE ECOLOGY AND GENETICS OF THE "SEX-RATIO" TRAIT IN NATURAL POPULATIONS OF DROSOPHILA PSEUDOOBSCURA

Baldwin, David George January 1979 (has links)
No description available.
15

Factors affecting adult sex ratios in bird populations

Venables, Joanne Ceri January 2013 (has links)
No description available.
16

Evidence that maternal diet alters steroid levels and primary offspring sex ration in the zebra finch

Okekpe, Chioma Camille, Mendonça, Mary T., January 2009 (has links)
Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references.
17

Studies on the life history and sex ratio of the harlequin bug, Murgantia histrionica (Hahn) with reference to the significance of the sex ratio /

Streams, Frederick Arthur, January 1962 (has links)
Thesis--Cornell University, 1962. / Includes bibliographical references (leaves 75-94).
18

(A)sexual Life of Liverworts / (A)sexual Life of Liverworts

HOLÁ, Eva January 2015 (has links)
This thesis comprises of two published papers and one accepted manuscript, focused on various aspects of liverwort reproduction. Treated aspects include patterns of asexual reproduction, sex ratio and sex-specic pattern in vegetative growth, and patterns of genetic variation and spatial genetic structure of populations differing in availability of substrate on localities and the population connectivity, and consequently in size, density, and prevailing reproductive mode. These characteristics were studied on representatives of the family Scapaniaceae s.l., belonging to the largest liverwort order Jungermanniales. The results showed that asexual propagules were formed and present in course of the whole growing season and can be considered as a sufficient substitution for sexual reproduction. In contrast with the female-biased sex ratio observed earlier in most dioicous bryophytes, unexpectedly high male-biased sex ratio was observed in the aquatic liverwort, which was speculated to represent a strategy to overcome sperm dilution in aquatic environment. In addition, no size differences between female and male shoots were detected, although the evidence for higher cost of sexual reproduction in females was found. The study of population genetic structure has shown that even small and predominantly asexually reproducing populations are important sources of genetic variation. However, we were able to demonstrate notably low levels of gene flow among populations where habitat fragmentation poses a significant barrier to dispersal of diaspores. The fine scale study of spatial genetic structure revealed a strong aggregation of genotypes, particularly in smaller populations, and at the same time showed that asexual reproduction is an efficient mean of maintaining the populations at not only the short distances, given the spatial extent of clones spanning dozens of meters.
19

Distinguishing Between the Endowment Effect and Buyer's Remorse in a Dating Scenario

January 2014 (has links)
abstract: Previous research on experiences of the endowment effect and buyer's remorse has often failed to compare the two seemingly related phenomena. The current study attempts to provide a framework in which the two can be compared and to offer a possible suggestion as to when it may be beneficial to experience either the endowment effect or buyer's remorse, namely situations of resource scarcity versus abundance. The current study employed an online dating paradigm in which resource scarcity was operationalized as the sex ratio of users on the site. Two hundred and one participants were exposed to a favorable sex ratio, an unfavorable sex ratio, or a no information control condition and asked to bid on potential dates. Once matched with a potential date, participants were asked how willing they would be to give up their date and the minimum amount of points they would request to do so. These dependent variables served as indicators of experiences of the endowment effect or buyer's remorse. Results indicated that the sex ratio of the online dating site did not influence experiences of the endowment effect versus buyer's remorse. Potential mediators and moderators were also investigated although no significant effects were found. Possible reasons for the null results are discussed as well as future directions. / Dissertation/Thesis / M.A. Psychology 2014
20

Does Religion Matter? A study of religion, sex ratio, son preference, and abortion attitude in China

Yunping Tong (9334985) 16 December 2020 (has links)
<p>The sex ratio at birth in China has been increasingly skewed in favor of males since 1980 when the government implemented the one-child policy to control population growth. Existing studies commonly point to economic factors and their weakening effect on the Confucian tradition of son preference to understand the male-biased sex ratio at birth; however, a perspective that heavily focuses on economic factors is limited. In this dissertation, I argue that bringing in religion – a key factor shaping individual attitudes and decisions related to son preference – can shed important light upon sex ratio at birth patterns in China.</p><p>This dissertation is divided into three empirical chapters. The first study explores religious effects on county-level sex ratios at birth using data from the 2000 China Population Census and the 2004 China Economic Census. Findings reveal that greater Daoist presence is associated with more imbalanced sex ratios in the county, while the presence of Islamic and Buddhist places of worship helps mitigate male-biased sex ratios. Study two askes how religious groups vary in their preferences for sons and sex selection decisions using data from the 2010 Chinese General Social Survey (CGSS). Findings suggest that Christians stand out for their weak son preference and refrain from sex selection, while Daoists hold strong son preference and more likely to practice sex selection to have many sons. The last study uses the CGSS data to explore whether religion shapes abortion attitudes among Chinese people. It shows that Islam and Christianity have a strong influence on the disapproval of abortion, and while affiliating with Daoism does not affect one’s approval of abortion, living in a neighborhood with more Daoists significantly reduces one’s approval of abortion.</p><div><p>These studies together demonstrate that religion is an important factor shaping not only individual attitudes and behaviors but also demographic trends in society. This dissertation serves as the first study that investigates the linkage between religion and demographic trends by examining how religion – both individual religious affiliation and religious context in a locality – affects the sex ratio at birth via shaping individual son preferences, sex selection decisions, and abortion attitudes. By highlighting religion – a factor that has been overlooked in demographic studies of China – this study contributes to a more nuanced understanding of imbalanced sex ratios and its determinants.</p></div><p></p>

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