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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.
1

Examining the Parent-Adolescent Bond and Parent-Offspring Marijuana Communication on Marijuana Use and Problems: A Test of Primary Socialization Theory

Zaharakis, Nikola 01 January 2015 (has links)
Marijuana use among American young adults is rising, and perceptions of harm are declining. Individual states continue to enact more lenient marijuana use and possession laws. Marijuana use is associated with many serious negative outcomes. Thus, marijuana use among this age group has become a public health concern. According to Primary Socialization Theory, parents exert their influence on youth behavior through the parent-adolescent bond and through communication. Previous researchers have identified parent-offspring communication about alcohol and tobacco as a potentially important target of prevention efforts. Little research has yet explored marijuana communication and its potential influence on use-related outcomes. This study sought to model the influence of the parent-adolescent bond and parent-offspring communication about marijuana on marijuana use and problems related to use. In order to model this influence, the Communication about Marijuana (CAM) measure first was developed. In Study 1, an initial pool of items tapping marijuana communication was tested using a sample of 18-25 year old (M=20.22) undergraduate students (N=433). Confirmatory factor analyses were performed to test the fit of the data to the proposed model. In Study 2, a revised CAM measure was tested with a second sample of 18-25 year old (M=20.40) undergraduate students (N=432). The final measure included four content topic factors comprising 9 items, and 3 descriptive items tapping communication context. Structural equation models were specified to model the parent-adolescent bond and marijuana communication content on student self-reported past year marijuana use and marijuana use problems. Results suggested that the parent-adolescent bond was protective on marijuana use frequency, while models including only the manifest variable parental support better fit the data with regard to marijuana use problems. Communication content was somewhat differentially related to outcomes. Discussions encouraging abstinence, offering advice on peer pressure and monitoring use were related to more frequent use. Communication that conveyed disappointment about marijuana use and offered advice about peer pressure and choosing non-using friends was related to more marijuana use problems. Positive relations between communication and use outcomes were unexpected, but may reflect reactive parenting. Results and implications for future research are discussed in the context of the extant literature.
2

Parental investment in canaries and zebra finches

Kilner, Rebecca Mary January 1996 (has links)
No description available.
3

Effect of Broiler Breeder Nutrition on Reproductive and Offspring Performance

Moraes, Thania Gislaine Vasconcelos de Unknown Date
No description available.
4

Exploring the impact of maternal obesity on offspring renal morphology and later life health

Pinnock, Adele Grace January 2018 (has links)
It is well established that exposure to adverse environments in early life including both maternal under and over-nutrition predisposes individuals to similar adverse traditionally adult onset diseases such as the metabolic syndrome. Epidemiological observations and animal models have highlighted that early life exposure to maternal under-nutrition has a detrimental effect on offspring kidney health. The prevalence of chronic kidney disease has increased rapidly in recent years, concurrently with the growing obesity epidemic. Obesity is now prevalent in all age groups within the population including women of child-bearing age. Despite this, the effect of early life exposure to maternal obesity on long-term kidney health has not been investigated in humans. Studies in animals have demonstrated that exposure to early life under-nutrition programs the offspring kidney. Offspring exposed to maternal calorie restriction or a low protein diet typically display a reduced number of nephrons and increased glomerular areas. No studies to date have investigated the effect of maternal obesity on early life kidney and glomerular morphology. To address this, as part of this thesis, kidney morphology was assessed at weaning in male mice exposed to maternal diet-induced obesity throughout gestation and lactation. There was no effect of maternal diet on the number of nephrons counted within a distinct region in the offspring kidneys. However, glomerular density was decreased and glomerular area was increased in offspring exposed to maternal obesity. Alterations in renal morphology in early life have been linked to hypertension and renal disease in adulthood in both epidemiological and animal studies. Therefore, a second aim of this thesis was to assess blood pressure, renal function and markers of renal damage in offspring exposed to maternal obesity throughout the life-course. Post-pubescent male offspring (8 weeks of age) exposed to maternal obesity displayed increased blood pressure but no signs of renal dysfunction or damage. However, by six months of age offspring exposed to maternal obesity had increased glomerulosclerosis and tubulointerstitial fibrosis. The obesity epidemic is attributed to a shift in behaviours towards consumption of energy dense foods and inactivity. In addition, evidence from human and animal studies has highlighted that exposure to maternal obesity primes offspring to prefer sugary and fatty foods and to consume more calories. As such, offspring exposed to maternal obesity are likely to encounter an obesogenic environment in later life. A third aim of this thesis was therefore to determine the effect of maternal obesity in combination with a post-weaning obesogenic diet on offspring kidney health. To address this aim, offspring either exposed to an obesogenic diet or control diet throughout pregnancy and lactation were weaned onto either an obesogenic or control diet themselves. Six month old offspring exposed to a post-weaning obesity alone displayed indices of renal dysfunction and damage including glomerulosclerosis and tubulointerstitial fibrosis. Importantly, exposure to maternal obesity exacerbated the renal fibrosis in offspring exposed to a post-weaning obesogenic diet. With the growing prevalence of maternal obesity globally, there is great interest in determining an effective intervention to prevent adverse health outcomes in exposed individuals. The Ozanne laboratory has shown that maternal exercise in obese dams during pregnancy reduces maternal serum insulin and offspring insulin to control levels, highlighting that maternal exercise may be a promising intervention to limit adult-onset diseases in offspring exposed to early life obesity. The final aim of this thesis was to therefore assess the effect of exercise during an obese pregnancy on markers of offspring renal development during late gestation. Gene markers of ureteric bud branching, an important precursor of nephrogenesis, were increased in fetuses exposed to maternal obesity with exercise as opposed to obesity alone. Additionally one of these gene markers correlated negatively with maternal insulin levels. Protein markers indicative of an active ureteric bud branching pathway were also increased in offspring exposed to maternal obesity with exercise. In conclusion, studies conducted in this thesis demonstrate that offspring exposed to maternal obesity show alterations in renal morphology in early life and are predisposed for renal disease in later life, especially when they are challenged with a post-weaning obesogenic diet. Maternal exercise might be an effective intervention to rescue offspring renal morphology and later life health associated with maternal obesity, however this requires further investigation. These results have important implications for future generations within the setting of an ever increasing obesity epidemic and a growing prevalence of chronic kidney diseases.
5

Cloning and Adoption: A Reply to Levy and Lotz

Strong, Carson 01 February 2008 (has links)
In previous articles I discussed the ethics of human reproductive cloning, focusing on a possible future scenario in which reproductive cloning can be accomplished without an elevated risk of anomalies to the children who are created. I argued that in such a scenario it would be ethically permissible for infertile couples to use cloning as a way to have genetically related children and that such use should not be prohibited. In 'Reproductive Cloning and a (Kind of) Genetic Fallacy', Neil Levy and Mianna Lotz raise objections to my conclusions. They disagree with the view, for which I argued, that some couples can have defensible reasons for desiring genetically related children. They also offer several new arguments against reproductive cloning, including an argument that it would diminish the number of adoptions, thereby adversely affecting the welfare of children who need to be adopted. In this paper I point out that Levy and Lotz's criticisms misconstrue my arguments and that there are serious problems with their arguments for prohibiting infertile couples from using cloning, including their argument from adoption.
6

Socio-Behavioral Correlates of 6- to 11-year-old Offspring of Alcohol Consuming Parents

Bacon, Jan Garver 01 May 1989 (has links)
There is a lack of simple random sample based research into whether there are social skill and behavior problem differences for six- to eleven-year-old boys and girls which correlate with rates of parental alcohol consumption, social sequelae of parental alcohol consumption, reported level of marital conflict, and extended family history of alcoholism. This simple random sample study correlates the above variables with T scores on the behavior problem and social competence scales of the Achenbach Child Behavior Checklist and Child Behavior Checklist - Teacher's Report Form for six- to eleven-year-old children (N=lOO). Behavior problem scales include disorders of affect, thought, and conduct, and attentional problems. Social competence scales include measures of activity level, social involvement, and school performance and working hard, behaving appropriately, learning, and happiness at school. Variables which demonstrate high correlations (p ≤ .05) are also examined using multiple regression. Both males and females are shown to be impacted both in magnitude and pervasiveness of effect. The single most affected dependent variable for both males and females is delinquent behaviors. Dad's score on the Michigan Alcoholism Screening Test is the independent variable that most frequently predicts the largest amount of variance in regression equations.
7

Melatonin Implants during Pregnancy on Maternal Hemodynamics and Growth of Offspring in Beef Cattle

McCarty, Keelee Jae 04 May 2018 (has links)
Melatonin is a strong antioxidant that has previously been observed to increase uteroplacental blood flow and increase postnatal calf growth when supplemented during gestation. The objective of the current study was to examine the effects of melatonin implants on uterine blood flow and subsequent offspring growth. Commercial beef heifers and cows were artificially inseminated and assigned to one of two treatment groups supplemented with (MEL) or without (CON) melatonin from days 180 to 240 of gestation. Total uterine artery blood flow was increased in MEL- versus CON-treated cattle. Fetal and birth weight were not different between treatments. However, at castration, body weight was increased in calves from MEL-treated dams compared with CON-treated dams. Further research on placental vascularization and the mechanism in which melatonin impacts angiogenic factors is necessary to understand the relationship between melatonin and compensatory growth that occurs in postnatal offspring.
8

Survival and Cell Acquisition Rates After Preimplantation Embryo Biopsy: Use of Two Mechanical Techniques and Two Mouse Strains

Roudebush, William E., Kim, Jong G., Minhas, Brijinder S., Dodson, Melvin G. 01 January 1990 (has links)
Two strains of mouse embryos at the four- and eight-cell stages had biopsy specimens obtained by means of two different mechanical techniques: aspiration and displacement. Embryos and biopsy specimen cells were evaluated for survival and development. Blastomere acquisition rates were significantly higher with the displacement biopsy technique; however, no difference in survival or developmental rates was found in blastomere biopsy specimens removed from either four-cell or eight-cell embryos. A maximum of one blastomere can be removed from a four-cell embryo, whereas three blastomeres can be taken at biopsy from an eight-cell mouse embryo without significantly affecting embryo development, although mouse strain differences were noted. Intact, viable, biopsied blastomeres will develop in vitro when cocultured with morphologically intact embryos. Births of live offspring after embryo biopsy are reported.
9

CHILDREN OF PARENTS DIAGNOSED WITH BIPOLAR DISORDER: AN INVESTIGATION OF THE BEHAVIOURAL, STRUCTURAL AND FUNCTIONAL CORRELATES OF RISK / NEURAL CORRELATES OF RISK IN CHILDREN OF PARENTS WITH BIPOLAR DISORDER

HANFORD, Lindsay 11 1900 (has links)
Emotion processing and regulatory deficits have been well established in individuals diagnosed with bipolar disorder (BD). Both structural and functional neural deficits have been associated with the presence of psychiatric symptoms in BD. In Chapter 2, we reviewed cortical thickness deficits found in patients with BD. It is unclear however, how early these deficits appear; whether they contribute to risk, or whether these deficits develop as a consequence of the onset of symptoms. To address this, many researchers have turned to high-risk offspring populations. These high-risk offspring are at much greater risk of developing BD by virtue of having a parent diagnosed with BD. Moreover, the presence of anxiety, depression or ADHD related symptoms in this population suggest these children are at even greater risk to develop BD. By comparing high-risk offspring with and without the symptoms can help to elicudate neural correlates associated with risk and resilience for BD. It was the aim of this thesis research to investigate the behavioural, structural and functional correlates of risk. Specifically, presented in this thesis, we compared the gray matter integrity, through volume (Chapter 3) and cortical thickness (Chapter 4) techniques, in symptomatic and asymptomatic high-risk offspring to healthy children of healthy parents. We also compared the ability of these offspring to perform an emotion-labelling task (Chapter 5) and engage in emotional conflict monitoring and conflict adaptation during an fMRI scan (Chapter 6). Altogether, our results provide evidence for the presence of gray matter volume, emotion labelling, and conflict monitoring and conflict adaptation functional deficits in high-risk offspring compared to healthy children of healthy parents. With the exception of cortical thickness, we found that the deficits between symptomatic and asymptomatic high-risk offspring were comparable. This suggests that behavioural, structural and functional deficits may reflect neural correlates of risk and are not associated with the presence of symptoms. / Thesis / Doctor of Philosophy (PhD)
10

Does Parental Bonding and Its Interaction with Child Temperament Influence Facial Affect Recognition in High-Risk Offspring for Developing Anxiety Disorders?

Ruci, Lorena January 2017 (has links)
Purpose: This thesis investigated whether perceived parental care and overprotection predicted accuracy of face emotion recognition in psychiatrically healthy youth. The study also examined whether child gender and having a parent with a history of anxiety moderated the relationship between parental bonding and facial emotion recognition, and whether behavioural inhibition mediated this relationship. Methods: The sample comprised 176 males and females aged 7-18 years. Participants completed the Parental Bonding Instrument, Childhood Self-Report of Inhibition, and the Ekman emotion recognition task. Results: Child gender and parental history of anxiety moderated the relationship between perceived parenting style and affect recognition. In boys, overprotection by father predicted deficits in recognizing fearful faces; in children with parental anxiety, low paternal care predicted deficits in recognizing angry faces; and in boys with parental anxiety, negative maternal bonding predicted deficits in recognizing expressions of surprise. Also, maternal overprotection predicted intensity of subjective anxiety while viewing expressions of surprise and happiness for all offspring, and behaviour inhibition mediated these relationships. Implications: The present study provides preliminary evidence that parental bonding interacts with risk group and gender in predicting accuracy of facial affect recognition in healthy youth. Further research is needed to confirm these findings and determine whether the interaction between gender, risk group and deficits in social cognition increase risk for developing pathological anxiety.

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