Individual variability in the behaviour and morphology of larval Atlantic cod (Gadus morhua, L.)

Individuals both within and between populations can vary markedly in a number of traits, including behaviour, life-history patterns and morphology. These differences do not simply reflect noise around a mean, but reflect real and important variability that can have a number of important implications. Such individual variability is especially prevalent among larval fish, which undergo significant changes in size, anatomy, physiology and morphology as they develop into adults. The potential for fish to develop differing behaviours and morphologies has important implications in the aquaculture environment. For example, some fish may be aggressive and/or cannibalistic while others are not, or some fish may have a propensity to take risks while others shy away from risk. Elucidation of the mechanisms underlying these differences could enable the farmer to mitigate the development of behaviours and morphologies that are not conducive with welfare and production. Such information would be especially useful in the rearing of species such as Atlantic cod, which are highly cannibalistic in the larval and early juvenile period of development. The purpose of the work outlined in this thesis was to elucidate certain aspects of individual variability in predominantly larval cod that relate to the culture of this species. An introduction to the subject area is provided in Chapter 1. Fish husbandry techniques followed the standard procedure employed at the two study sites and are described in detail in chapter 2. This chapter also describes the morphometric technique used to analyse morphology, principal component analysis of linear measurements, and discusses the reasons for adopting this technique. Chapters 3 and 4 examine morphological development in larval cod reared under standard culture conditions and using common commercial feeds, for the purpose of elucidating developments in trophic morphology that could potentially relate to the development of cannibalism in this species. Chapter 3 specifically examines patterns of change in head shape in larval Atlantic cod and the extent to which head development varies within a cohort, while chapter 4 examines the effect of diet on the development of head morphology in larval cod. The former of these studies identified clear and consistent patterns of growth in various measures of head structure (and especially eye diameter). This was with the exception of jaw width, which developed in opposition to these measures. Periods of rapid change in head morphology coincided with points at which the larval diet changed and may have been caused by this change. Growth of the head and the post cranium was highly variable, especially in the latter stages of larval development and investment in head growth relative to post-cranial growth increased over the first two thirds of larval development, remaining constant thereafter. The second of these studies found that fish fed different prey types developed different head morphology. Specifically, fish fed small prey developed more fragile heads and larger eyes relative to jaw width than fish fed larger prey. Analysis of the head morphology of dead fish indicated that at least some of these differences resulted, not from the death of certain morphotypes, but from a phenotypically plastic response to the different diets. The morphology of a small number of cannibalistic larvae analysed during the study indicated that fish fed the larger prey developed morphology comparable with that of cannibalistic morphs. In the study detailed in chapter 5, aggressive interactions in larval cod were quantified in order to determine whether these interactions represented an early form of cannibalism or a battle for resources. Attacks where characterised by brief, one-way, nips by an attacker to a victim. Fish also commonly exhibited a pattern of burst swimming (darts) that appeared to reflect a generalised escape response. This darting behaviour was not affected by the presence of food, but was more common in fish fed the higher prey densities. Conversely, overall levels of prey did not affect the incidence of aggressive attacks, although analysis was confounded by a decline in levels of aggression with increasing fish density. The frequency of nips was highest when food was absent and nips were preferentially directed at the tail of victims, to victims of a smaller or similar size than the attacker and to victims that showed abnormal body posture. These findings indicated that at least some attacks by larval cod represented an early attempt at cannibalism. Chapter 6 details a study in which differences in the risk taking behaviour of one-year old cod of different stock and/or family origin were examined. Fish of North-eastern Arctic stock origin were found to be more prone to take risks than fish of Norwegian coastal stock origin. Furthermore, although there were no significant differences in risk-taking between families of North-eastern Arctic stock origin, a weakly significant difference existed between families of fish originating from coastal stock. The weight and condition of fish was significantly smaller in fish that emerged to escape than in fish that avoided risk and these factors may have contributed to the observed behavioural differences between stocks and families. Cortisol levels did not vary between risk avoiders or risk takers, but were significantly higher in control fish of North-eastern Arctic stock origin compared to control fish of coastal origin. These results provided evidence for a heritable component to risk-taking in cod. The results of the aforementioned studies have important implications, particularly for the culture of cod and these implications are discussed in Chapter 7, together with a summary of the objectives and findings of each study. The future studies that are prompted by these findings are also considered

Pubs in Public Life: A Place for Liquor Spaces in the City of Vancouver

Vancouver liquor licensing bylaws has been described by members of the media, industry, government and general public as overly restrictive, especially in the areas of hours ofservice, geographical distribution and the cultural diversity ofpublic liquor spaces. According to the City of Vancouver, the objective of city stewardship is to provide for the social, economic and physical well-being of citizens. A consultation of both academic research and the Vancouver community suggests that public liquor consumption sites can contribute positively to the social, economic and physical well- being of citizens. This paper explores how a reexamination and considered relaxation of liquor licensing bylaws could strengthen the viability and vitality of Vancouver.&nbsp

Post-implementation assessment of novel rodent control devices for protection of high elevation endangered species at Hawai`i Volcanoes National Park

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.Invasive species, including rats, threaten the existence of many of Hawai`i’s native species pushing them to the brink of extinction. Hawai`i Volcanoes National Park has a long history of successfully managing ecosystems and providing rare species habitat through systematic invasive species control. Landscape level rodent control is prohibitively expensive; however, localized control has proven cost-effective while providing significant resource benefit. A trapping program using self-resetting Goodnature® A24 technology was implemented at two remote sites in Hawai`i Volcanoes National Park in an effort to protect five endangered plant species and three endangered bird species from black rat (Rattus rattus) predation. This trapping method has been successfully implemented on other islands, but implementation requirements are site specific. Techniques and maintenance schedules were investigated specifically for subalpine dry shrubland environments and also high elevation wet forest environments. Trap performance, recommended grid spacing, and a new chocolate long-life lure formula were evaluated over the course of this investigation. Apparent rodent control trends and subsequent native species responses were captured over the course of four months by conducting biweekly trap visits and analyzing motion triggered camera footage. Clear declines in rodent activity were documented at each site during the four month intensive monitoring period. At least 38 rodents were removed from the subalpine dry shrubland test site during this period, while at the high elevation wet forest site at least 102 rodents were removed. It is suspected that the number of total kills was underestimated using available monitoring techniques. Trapping activity appeared to prevent major damage to flowers and diminish damage to fruit of endangered Campanulaceae species at the forested test site, however it is unclear what effect trapping efforts had on native bird species at the subalpine shrubland site. Management recommendations differ by site. For subalpine shrubland sites, trap spacing should not exceed 100m x 100m to control M. musculus or R. rattus; tighter spacing may be necessary. In high elevation wet forests spacing traps at 50m x 50m is recommended to effectively reduce R. rattus populations. Pre-baiting traps is not advised to minimize potential damage done by rodents gnawing on depressurized traps. Concurrent trapping for feral cats and other scavengers, or strategic trapping schedules, are recommended to mitigate potential secondary predator attraction for sensitive sites such as Hawaiian petrel nesting areas. Schedule of trap maintenance should include monthly lure checks and ‘refreshment’ squeezes, regardless of site ecosystem. Scent of the lure diminishes between refreshment visits in arid environments and may be masked by algae or mold in wet environments. Use of the Goodnature® automatic lure pump should be considered to potentially alleviate this issue. In both environments standard lure bottles were found to last through the 16 week monitoring period. Lure was found to remain attractive to rodents, after refreshment squeezes as long as 36 weeks after deployment at the forested site. Trap maintenance should be scheduled to check CO2 status no later than 12 weeks after deployment, regardless of site ecosystem, to detect exhausted CO2 or malfunctioning traps, and at monthly maintenance visits if possible. Use of a surrogate pest such as a rubber rat to test fire through the trap shroud is advised to accurately simulate a strike, and ensure functionality of digital strik

AphasiaBank: Preliminary Lexical, Morphosyntactic, and Error Analyses

AphasiaBank collects and analyzes samples of the discourse of individuals with aphasia and normal participants across a range of tasks. The goal of AphasiaBank is to assemble a large repository of video-recorded discourse samples, transcribed in a format that facilitates extensive computerized language analyses. This paper outlines the AphasiaBank protocol and presents core analyses of language samples from 15 normal adults and 15 individuals with aphasia using selected analyses for lexicon, morphosyntax, errors, and repetition

Experiences of a Novice Researcher Conducting Focus Group Interviews

The purpose of this paper is to report what I learned about how to conduct focus group interviews that produce insightful, revealing and informative data.  I will discuss my experiences facilitating focus group interviews as a novice researcher and compare these experiences with the literature.  I planned the focus groups in collaboration with a research team, recruited participants from various units at the local tertiary care hospital and set up the meeting rooms for the groups.  I then facilitated the focus groups with the support of an assistant.  Following the focus groups, I documented my field notes, as well as my personal reflective memos.  I downloaded the audio recordings, de-identified the written transcripts, and reviewed them for accuracy prior to analysis.  A number of concepts emerged that merit particular attention: challenges with recruitment, the use of field notes and reflective memos, the benefits and limitations of using a flip chart, importance of professional support, using homogenous groups, and attending to the set-up of the environment.  As the focus group interview becomes an increasingly popular data collection method in qualitative research, my experiences could inform the preparation of other novice researchers as they undertake their own focus groups

Integration of a 3D Variational data assimilation scheme with a coastal area morphodynamic model of Morecambe Bay

This paper describes the implementation of a 3D variational (3D-Var) data assimilation scheme for a morphodynamic model applied to Morecambe Bay, UK. A simple decoupled hydrodynamic and sediment transport model is combined with a data assimilation scheme to investigate the ability of such methods to improve the accuracy of the predicted bathymetry. The inverse forecast error covariance matrix is modelled using a Laplacian approximation which is calibrated for the length scale parameter required. Calibration is also performed for the Soulsby-van Rijn sediment transport equations. The data used for assimilation purposes comprises waterlines derived from SAR imagery covering the entire period of the model run, and swath bathymetry data collected by a ship-borne survey for one date towards the end of the model run. A LiDAR survey of the entire bay carried out in November 2005 is used for validation purposes. The comparison of the predictive ability of the model alone with the model-forecast-assimilation system demonstrates that using data assimilation significantly improves the forecast skill. An investigation of the assimilation of the swath bathymetry as well as the waterlines demonstrates that the overall improvement is initially large, but decreases over time as the bathymetry evolves away from that observed by the survey. The result of combining the calibration runs into a pseudo-ensemble provides a higher skill score than for a single optimized model run. A brief comparison of the Optimal Interpolation assimilation method with the 3D-Var method shows that the two schemes give similar results

Translational recoding as a feedback controller : systems approaches reveal polyamine-specific effects on the antizyme ribosomal frameshift

Peer reviewedPublisher PD

Risk of herpes zoster after exposure to varicella to explore the exogenous boosting hypothesis: self controlled case series study using UK electronic healthcare data.

OBJECTIVE: To assess the magnitude and duration of any hypothesised protective effect of household exposure to a child with varicella on the relative incidence of herpes zoster in adults. DESIGN: Self controlled case series. SETTING: UK general practices contributing to Clinical Practice Research Datalink. PARTICIPANTS: 9604 adults (≥18 years) with a diagnosis of herpes zoster (in primary care or hospital records) between 1997 and 2018, who during their observation period lived with a child (<18 years) with a diagnosis of varicella. MAIN OUTCOME MEASURES: Relative incidence of herpes zoster in the 20 years after exposure to a child with varicella in the household compared with baseline time (all other time, excluding the 60 days before exposure). RESULTS: 6584 of the 9604 adults with herpes zoster (68.6%) were women. Median age of exposure to a child with varicella was 38.3 years (interquartile range 32.3-48.8 years) and median observation period was 14.7 (11.1-17.7) years. 4116 adults developed zoster in the baseline period, 433 in the 60 days before exposure and 5055 in the risk period. After adjustment for age, calendar time, and season, strong evidence suggested that in the two years after household exposure to a child with varicella, adults were 33% less likely to develop zoster (incidence ratio 0.67, 95% confidence interval 0.62 to 0.73) compared with baseline time. In the 10-20 years after exposure, adults were 27% less likely to develop herpes zoster (0.73, 0.62 to 0.87) compared with baseline time. A stronger boosting effect was observed among men than among women after exposure to varicella. CONCLUSIONS: The relative incidence of zoster was lower in the periods after exposure to a household contact with varicella, with modest but long lasting protective effects observed. This study suggests that exogenous boosting provides some protection from the risk of herpes zoster, but not complete immunity, as assumed by previous cost effectiveness estimates of varicella immunisation

Age-Related Kidney Transplant Outcomes: Health Disparities Amplified in Adolescence

IMPORTANCE The transition from pediatric to adult health care is a vulnerable time for patients with chronic conditions. We need to better understand the factors affecting the health of kidney transplant recipients during this transition. OBJECTIVE To determine the age at which renal transplant recipients are at greatest risk for graft loss. DESIGN, SETTING, AND PARTICIPANTS We performed a retrospective analysis of 168 809 first kidney-only transplant events from October 1987 through October 2010, in recipients up to age 55 years as reported by the Organ Procurement Transplantation Network Standard Transplant Analysis and Research Database. Recipient age at transplant was the primary predictor studied. Confounder and effect modifier covariates were identified and studied using Cox proportional hazard models. EXPOSURE Kidney-only transplant. MAIN OUTCOMES AND MEASURES Patient and renal graft survival, along with death-censored and non―death-censored information. RESULTS A total of 168 809 renal transplant events met the inclusion criteria. Recipients who received their first kidney transplant at age 14 to 16 years were at the highest risk of graft loss, with inferior outcomes starting at 1 and amplifying at 3, 5, and 10 years after transplant. Black adolescents were at disproportionately high risk of graft failure. The variables that had significant interaction with recipient age were donor type (deceased vs living) and insurance type (government vs private). Among 14-year-old recipients, the risk of death was 175% greater in the deceased donor-government insurance group vs the living donor―private insurance group (hazard ratio, 0.92 [95% CI, 0.90-0.94] vs 0.34 [95% CI, 0.33-0.36]), whereas patient survival rates in the living donor―government insurance and deceased donor―private insurance groups were nearly identical (hazard ratio, 0.61 [95% CI, 0.58-0.63] vs 0.54 [95% CI, 0.51-0.56]). CONCLUSIONS AND RELEVANCE Recipients aged 14 to 16 years have the greatest risk of kidney allograft failure. Black adolescents and those with government insurance are at even higher risk. Private insurance reduces risk of death across all ages. Comprehensive programs are needed for adolescents, especially for those at greater risk, to reduce graft loss during the transition from adolescence to adulthood