Egg quality and fecundity in rainbow trout: the determining factors and mechanisms of control

This thesis considers the factors involved in the determination of egg quality and fecundity in farmed stocks of rainbow trout ( Salmo gairdneri R) • Measurements of egg quality, ie. percentage survivals of eggs and fry, from the production batches of eggs of seven fish farms, showed mean survivals of 70% to eying but levels of only 35% to 4.5g fry (approx. 130 days post-fertilisation). Under optimum conditions survivals may reach 85% suggesting that husbandry methods exert significant influences on egg quality. Chemical analyses of the protein, fat, vitellogenin, ash, amino acids, free fatty acid and mineral levels of eggs of varying quality and from parents of different strains showed compositional differences even between individuals of the same stock. However, none of these differences were correlated with egg quality. Egg size showed similar variations but, again under hatchery conditions there was no correlation with differences in egg quality. The only factor which has been shown to exert a significant influence on egg quality is the time of stripping after ovulation. At 1 0°C eggs should be removed from gravid females within ten days of ovulation to achieve optimum egg and fry survival. Studies of egg production from approximately 10,000 broodstock revealed that total fecundity and egg size increased and relative fecundity decreased with increasing fish size. In general, most fish appeared to produce a constant volume of eggs. This is consistent with a hypothesis that egg size can only be increased by parallel reductions in fecundity. Feeding broodstock at half-ration (0.35% body weight day- 1 ) did not affect egg quality but reduced total fecundity and egg size and increased relative fecundity when compared with eggs produced by fish on full-ration. Comparisons of regressions of total fecundity against fish weight for three strains using ANOCO revealed that one strain was significantly more fecund than two other strains considered. Trout of the same strain maintained on different farms behaved similarly suggesting there was some reproducibility of strain characteristics.

Parental diet, pregnancy outcomes and offspring health:metabolic determinants in developing oocytes and embryos

The periconceptional period, embracing the terminal stages of oocyte growth and post-fertilisation development up to implantation, is sensitive to parental nutrition. Deficiencies or excesses in a range of macro- and micronutrients during this period can lead to impairments in fertility, fetal development and long-term offspring health. Obesity and genotype-related differences in regional adiposity are associated with impaired liver function and insulin resistance, and contribute to fatty acid-mediated impairments in sperm viability and oocyte and embryo quality, all of which are associated with endoplasmic reticulum stress and compromised fertility. Disturbances to maternal protein metabolism can elevate ammonium concentrations in reproductive tissues and disturb embryo and fetal development. Associated with this are disturbances to one-carbon metabolism, which can lead to epigenetic modifications to DNA and associated proteins in offspring that are both insulin resistant and hypertensive. Many enzymes involved in epigenetic gene regulation use metabolic cosubstrates (e.g. acetyl CoA and S-adenosyl methionine) to modify DNA and associated proteins, and so act as 'metabolic sensors' providing a link between parental nutritional status and gene regulation. Separate to their genomic contribution, spermatozoa can also influence embryo development via direct interactions with the egg and by seminal plasma components that act on oviductal and uterine tissues. © IETS 2014.

Tissue transglutaminase:a mediator and predictor of chronic allograft nephropathy?

Background. The precise mechanisms underlying the development of chronic allograft nephropathy (CAN) and the associated renal fibrosis remain uncertain. The protein-crosslinking enzyme, tissue transglutaminase (tTg), has recently been implicated in renal fibrosis. Methods. We investigated the involvement of tTg and its crosslink product, [epsilon]-([gamma]-glutamyl) lysine, in 23 human kidney allografts during the early posttransplantation period and related these to changes of CAN that developed in 8 of them. Sequential biopsies were investigated using immunohistochemical, immunofluorescence, and in situ enzyme activity techniques. Results. From implantation, tTg (+266%) and [epsilon]-([gamma]-glutamyl) lysine crosslink (+256.3%) staining increased significantly (P <0.001) in a first renal biopsy performed within 3 months from transplantation. This was paralleled by elevated tTg in situ activity. The eight patients who developed CAN had further increases in immunostainable tTg (+197.2%, P <0.001) and [epsilon]-([gamma]-glutamyl) lysine bonds (+465%, P <0.01) that correlated with interstitial fibrosis (r=0.843, P =0.009 and r=0.622, P =0.05, respectively). The staining for both was predominantly located within the mesangium and the renal interstitium. Both implantation and first biopsies showed tTg and [epsilon]-([gamma]-glutamyl) lysine crosslinking levels in patients who developed CAN to be twice the levels of those with stable renal function. Cox regression analysis suggested the intensity of the early tTg staining was a better predictor of inferior allograft survival that other histologic markers (hazard ratio=4.48, P =0.04). Conclusions. tTg and [epsilon]-([gamma]-glutamyl) lysine crosslink correlated with the initiation and progression of scarring on sequential biopsies from renal-allograft recipients who experienced CAN. Elevated tTg may offer an early predictor of the development of CAN, whereas tTg manipulation may be an attractive therapeutic target

Parental confidence in managing food allergy:development of the Food Allergy Self-Efficacy Scale for parents (FASE-P)

Background: Food allergy is often a life-long condition that requires constant vigilance in order to prevent accidental exposure and avoid potentially life-threatening symptoms. Parents’ confidence in managing their child’s food allergy may relate to the poor quality of life anxiety and worry reported by parents of food allergic children. Objective: The aim of the current study was to develop and validate the first scale to measure parental confidence (self-efficacy) in managing food allergy in their child. Methods: The Food Allergy Self-Efficacy Scale for Parents (FASE-P) was developed through interviews with 53 parents, consultation of the literature and experts in the area. The FASE-P was then completed by 434 parents of food allergic children from a general population sample in addition to the General Self-Efficacy Scale (GSES), the Food Allergy Quality of Life Parental Burden Scale (FAQL-PB), the General Health Questionnaire (GHQ12) and the Food Allergy Impact Measure (FAIM). A total of 250 parents completed the re-test of the FASE-P. Results: Factor and reliability analysis resulted in a 21 item scale with 5 sub-scales. The overall scale and sub-scales has good to excellent internal consistency (α’s of 0.63-0.89) and the scale is stable over time. There were low to moderate significant correlations with the GSES, FAIM and GHQ12 and strong correlations with the FAQL-PB, with better parental confidence relating to better general self-efficacy, better quality of life and better mental health in the parent. Poorer self-efficacy was related to egg and milk allergy; self-efficacy was not related to severity of allergy. Conclusions and clinical relevance: The FASE-P is a reliable and valid scale for use with parents from a general population. Its application within clinical settings could aid provision of advice and improve targeted interventions by identifying areas where parents have less confidence in managing their child’s food allergy.

A seismic shift? An evaluation of the impact of new media on perceptions of freedom of expression and privacy

New media platforms have changed the media landscape forever, as they have altered our perceptions of the limits of communication, and reception of information. Platforms such as Facebook, Twitter and WhatsApp enable individuals to circumvent the traditional mass media, converging audience and producer to create millions of ‘citizen journalists’. This new breed of journalist uses these platforms as a way of, not only receiving news, but of instantaneously, and often spontaneously, expressing opinions and venting and sharing emotions, thoughts and feelings. They are liberated from cultural and physical restraints, such as time, space and location, and they are not constrained by factors that impact upon the traditional media, such as editorial control, owner or political bias or the pressures of generating commercial revenue. A consequence of the way in which these platforms have become ingrained within our social culture is that habits, conventions and social norms, that were once informal and transitory manifestations of social life, are now infused within their use. What were casual and ephemeral actions and/or acts of expression, such as conversing with friends or colleagues or swapping/displaying pictures, or exchanging thoughts that were once kept private, or maybe shared with a select few, have now become formalised and potentially permanent, on view for the world to see. Incidentally, ‘traditional’ journalists and media outlets are also utilising new media, as it allows them to react, and disseminate news, instantaneously, within a hyper-competitive marketplace. However, in a world where we are saturated, not only by citizen journalists, but by traditional media outlets, offering access to news and opinion twenty-four hours a day, via multiple new media platforms, there is increased pressure to ‘break’ news fast and first. This paper will argue that new media, and the culture and environment it has created, for citizen journalists, traditional journalists and the media generally, has altered our perceptions of the limits and boundaries of freedom of expression dramatically, and that the corollary to this seismic shift is the impact on the notion of privacy and private life. Consequently, this paper will examine what a reasonable expectation of privacy may now mean, in a new media world.

Do gender and year of study affect the ability of the theory of planned behaviour to predict binge-drinking intentions and episodes?

Background: The present study tested the utility of the theory of planned behaviour (TPB), augmented with anticipated regret, as a model to predict binge-drinking intentions and episodes among female and male undergraduates and undergraduates in different years of study. Method: Undergraduate students (N = 180, 54 males, 126 females, 60 per year of study) completed baseline measures of demographic variables, binge-drinking episodes (BDE), TPB constructs and anticipated regret. BDE were assessed one-week later. Results: The TPB accounted for 60% of the variance in female undergraduates' intentions and 54% of the variance in male undergraduates' intentions. The TPB accounted for 57% of the variance in intentions in first-year undergraduates, 63% of the variance in intentions in second-year undergraduates and 68% of the variance in intentions in final-year undergraduates. Follow-up BDE was predicted by intentions and baseline BDE for female undergraduates as well as second- and final-year undergraduates. Baseline BDE predicted male undergraduates’ follow-up BDE and first-year undergraduates’ follow-up BDE. Conclusion: Results show that while the TPB constructs predict undergraduates’ binge-drinking intentions, intentions only predict BDE in female undergraduates, second- and final-year undergraduates. Implications of these findings for interventions to reduce binge drinking are outlined.