Although nest reuse is most commonly associated with costs such as nest instability and increased ectoparasite loads,contrary evidence supports the possibility that nest reuse might provide an adaptive function in the form of time and energy savings. The Cave Swallow (Petrochelidon fulva), which nests under bridges and culverts in east-central Texas, chooses predominately to reuse nests when old nests are available. I conducted a field experiment involving bridge pairs and single bridges, in which I applied a treatment of nest removal to one bridge of each pair and one half of each single bridge in order to test whether control bridges and nests exhibited increased productivity from the availability of old nests. I found that a higher percentage of young fledged from control bridges and more fledged per clutch from control bridges. Small sample sizes diminished the ability to detect differences within the single bridge experiment. Results from this research support the time-energy savings concept and may be reconciled with conflicting research through fundamental differences between studies in immunity to ectoparasites, infestation type, and nest microclimate.

Data from 75 F2 Brahman-Hereford cows of four specific breed combinations, F2 HB (produced by F1 HB sires x F1 HB dams, where “HB” refers to cattle sired by Hereford bulls and out of Brahman cows), F2 BH (produced by F1 BH sires x F1 BH dams), HB x BH and BH x HB, were evaluated for maternal performance at the Texas A&M Research Center near McGregor. Differences between breed combinations were analyzed for calf crop born (CCB), calf crop weaned (CCW), calf survival (CS), birth weight (BW), weaning weight (WW), and cow weight at palpation (PW). The adjusted means for F2 HB, F2 BH, HB x BH, and BH x HB were 0.84 ± 0.06, 0.57 ± 0.07, 0.82 ± 0.06, and 0.62 ± 0.08, respectively, for CCW. F2 HB cows had a 0.27 ± 0.09 higher percent calf crop weaned than F2 BH cows (P < 0.01) and a 0.22 ± 0.11 higher percent calf crop weaned than BH x HB cows (P < 0.05). HB x BH cows had a 0.25 ± 0.08 higher percent calf crop weaned than F2 BH (P < 0.01) and a 0.20 ± 0.10 higher percent calf crop weaned than BH x HB cows (P < 0.05). As 6-year-olds, the adjusted means for cow weight at palpation for F2 HB, F2 BH, HB x BH, and BH x HB cows were 523.65 ± 20.49 kg, 602.61 ± 23.63 kg, 492.84 ± 16.98 kg, and 515.93 ± 22.96 kg, respectively. Averaged across all ages, HB x BH cows weighed 56.59 ± 15.29 kg less than F2 BH cows (P < 0.001) and 41.11 ± 18.92 kg less than BH x HB cows (P < 0.05). Also, F2 HB cows weighed 40.45 ± 17.68 kg less than F2 BH cows (P < 0.05). In this herd, HB-sired cows had higher reproductive efficiency than BH-sired cows. Also, HB-sired cows tended to be lighter than BH-sired cows. Although these differences existed, exact causes could not be determined primarily due to confounding between the birth year of the cow and the sire breed of the cow.

Phocid seals (true seals, Order Carnivora, Family Phocidae) use a diverse array of breeding habitats and strategies, and produce many vocalizations. Therefore, phocids are well suited as subjects for study of reproductive strategies and the role of vocalizations in species mating at sea. However, the amount of information is still limited for aquatically breeding pinnipeds. Using underwater audio and video recordings of Weddell seals (Leptonychotes weddellii) interacting in McMurdo Sound, I compared the frequencies of vocalizations and behaviors of males and females during the mating season. I also investigated differences in these frequencies based on the social context. Finally, I identified patterns of vocalizations and behaviors to help determine the behavioral context of calls and used this information as a basis for considering the degree of ritualization in Weddell seal displays. Mews, growls, knocks, and trills were found to be almost exclusively male-specific. The territorial male produced chirps more often when another male was present in its territory; whereas, mews and growls were more frequent when one or more free-ranging females were present. Several vocal and behavioral padeparture of the territorial male into or from the breathing hole. In the context of an evolutionary-based model of communication, these findings suggest that low-frequency vocalizations and stereotyped displays produced by territorial males may have been favored by sexual selection: they may provide reliable information to females about the fitness of the signaler and influence their choice of mate. They may also help in limiting conflicts between the territorial male and females over access to the breathing hole.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

Thesis (M.S.W.)--York University, 1998. Graduate Programme in Social Work. / Typescript. Includes bibliographical references (leaves 186-205). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ39237

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 15, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Raymond D. Semlitsch Vita. Includes bibliographical references.

In this field study, female social workers perspectives have been collected, on interventions regarding sexual and reproductive health in the public sector in Argentina. The purpose was primary empirical and secondary to analyze empirical data using critical theory. The methodology was qualitative and the theoretical framework was created using an abductive approach. Thirteen female social workers were interviewed in the municipality of general Pueyrredón, in the province of Buenos Aires. Empirical data was categorized using the hermeneutic approach; described and analyzed using critical theory. Results presented challenges regarding lack of accessibility, continuity and accountability, from the nation, the province and the municipality. Moreover, results show challenges on how to target vulnerable groups, adolescents, people with low intellectual disability, people from neighboring countries, and from the north of Argentina. In addition, there were challenges on how to increase correct use and use of contraceptives. Suggestions were to make interventions more adaptable and creative. Stressed challenges were regarding male involvement in sexual and reproductive health decisions, gender violence, the patriarchal society, and the macho culture. Critical theory highlighted challenges created by Argentina’s societal structures, structures that contribute to oppression of service users, making them powerless and marginalized. By increasing the knowledge of critical social work theory in social work education, there would be more tools for social workers to use it in practice. When using critical social work theory all levels in a society shall be included. Specific policies and interventions are requested to battle female discrimination.

Behavioral isolation is an important barrier to gene flow, contributing to the formation and maintenance of animal species. Nevertheless, hybridization occurs more commonly than is generally recognized, occurring in over ten percent of animal species in the wild. Although the genetic consequences of hybridization are of considerable interest given their evolutionary implications, the reasons that animals choose to mate with other species are less clear. I apply mate choice theory to the question of hybridization, using wood warblers (family Parulidae) and swordtail fishes (genus Xiphophorus) as study systems. Over half of the 45 species of North American wood warbler have produced hybrids. Using comparative methods, I address the questions: Do ecological and demographic factors predict hybridization in this family? Similarly, how do phylogeny, song similarity, and sympatry with congeners correlate with hybridization? As with North American wood warblers, behavioral isolation is also considered of primary importance in isolating sympatric species of swordtail fishes. Two species, X. birchmanni and X. malinche, hybridize in several locations in the wild. Through experimentation with these and other Xiphophorus species, I investigate some of the factors that cause female mate choice to vary, possibly contributing to hybridization. Specifically, I address the following questions: Do females become less choosy when predation risk is high, or encounter rates with conspecifics are low? Are female preferences for conspecifics innate, or can they be modified by experience? And, do female preferences for conspecifics vary among species, populations, or experiments? These studies illustrate the utility of treating hybridization as just another possible outcome of variation in mate choice. I find that warbler hybridization correlates with ecological and other variables, that female swordtails become more responsive to heterospecifics when mate choice is costly, and that female preferences for conspecifics are species- and context-dependent. As animal hybridization can have important evolutionary consequences, studying the factors that contribute to this variation can enhance our understanding of the evolutionary process. / text

This dissertation begins with the finding that in the United States Black women are four times as likely to die due to pregnancy related complications than their white counterparts as well as the finding that Black children are 2 to 2.5 times as likely to die before their first birthday. Given this, the project examines the intersections between Black women’s reproductive experiences and the condition of reproductive health and access in the state of Texas. In order to accomplish this, the research situates the grassroots organizing work of a collective of mothers of color alongside national and state level legislation and data about maternal and infant health disparities. The work not only situates ethnographic experiences within the larger repertoire of quantitative health literature on disparities but it also historicizes the work alongside Black Feminist theories of the body, history, and Black women’s reproduction. Drawing from extended participant observations, interviews, focus groups, policy research, statistics, and archival work, this project unpacks the large disparity that exists in maternal and infant health outcomes for African-American women and the ways in which policy, community organizing, and other geo-political factors contribute to, mediate, or remedy this phenomenon. Given the data presented, this projects suggests that (re)creating supportive communities and support networks may be an effective way of mediating stress caused by long-term exposures to racism and ultimately healing the negative maternal health outcomes for black women. / text

Recently, progress was made in collecting, classifying, and characterizing the genetic diversity of type 2 porcine reproductive and respiratory syndrome virus (PRRSV) using all known and publically available sequencing information. Despite this voluminous attempt, these analyses were largely na?ve of the Canadian contribution to circulating viruses. This represented a vital omission in the study of molecular epidemiology due to the fact that Canada had recorded the earliest evidence of the existence of type 2 PRRSV. To this end, the genetic diversity and evolutionary aspects of PRRSVs distributed in the Province of Ontario in Canada were characterized to abridge this existing knowledge gap on type 2 PRRSV. Genotyping of type 2 strains is primarily based on either a phylogenetic or restriction fragment length polymorphism (RFLP) approach. Classification of Ontario PRRSV field isolates (n = 505) from 1999 to 2010, based on a global type 2 PRRSV ORF5 phylogenetic framework, revealed genetic diversity comparable to PRRSV in the USA, with sequences assigned to five of nine lineages (1, 2, 5, 8 and 9). A majority (~85%) of these isolates were typed to the first two lineages (1 and 2). Despite a relatively smaller sample size to the USA, the topology of the phylogenetic tree indicated Canadian origins of these two lineages. Mapping RFLP patterns of Ontario isolates onto the phylogenetic tree revealed numerous examples of different patterns located within the same phylogenetic cluster. Examples of the non-specificity of RFLP patterns to any particular lineage or sub-lineage were abound. Statistical analysis showed occurrences where similar RFLP patterns masked diverse genetic distances and instances of close genetic proximity with divergent RFLP patterns. An examination of the most abundant 15 RFLP patterns revealed that the discrepancy between RFLP typing and genetic distances was not attributable to a single or few patterns but was rather a permeating feature. Importantly, the tree topology also indicated a Canadian ancestry for the highly virulent MN184-related strains that first emerged in 2001 in the USA. Selective pressure analyses highlighted a handful of positively selected sites most of which were located in the ORF5 ectodomains of outbreak strains, implicating the host immune system as the possible selective agent. This was in contrast to the closely-related Ontario strains which were subject to strong purifying selection. A broader survey of transmission dynamics in North America unveiled a higher virus flow from Canada to the USA with the primary targets being the Lake States and Corn Belt. In turn, these regions served to disseminate viruses to other swine production regions in the USA. Virus flow from the USA to Canada occurred on a much smaller scale. Collectively, extensive genetic diversity prevails in type 2 PRRSV in one region of the North American swine industry and it is not described adequately by RFLP typing which might have some value in differentiating strains at the local farm level, instead. For diagnostic and research purposes, phylogenetic typing should be the preferred method. Finally, stronger surveillance needs to be adopted to minimize cross-border virus transmission. / published_or_final_version / Biological Sciences / Master / Master of Philosophy