Nutrient utilisation, growth and chemical body composition of pre-weaned lambs reared artificially : effects of feeding milk replacer and pellets : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, Manawatū, New Zealand

Listed in 2016 Dean's List of Exceptional ThesesUnderstanding how nutrient supply controls lamb growth is important in improving the efficiency of nutrient utilisation. Estimation of metabolisable energy (ME) requirements for lamb maintenance and growth pre-weaning has been limited to milk-only fed lambs. This is due, at least in part, to the difficulty of measuring pasture intake in pre-weaned lambs, which restricts the determination of nutrient balances and nutrient use efficiencies. The aims of this thesis were to: 1) evaluate the effect of various milk and pellets combinations on lamb growth, organ development, body composition and utilisation of energy for maintenance and growth, 2) derive equations for predicting feed intake, and 3) develop a growth simulation model for use as a tool to develop feeding strategies for lambs. Lambs were offered various diet combinations from age one day until slaughter at 18 kg live weight (LW). Addition of solid feed to the milk diet of pre-weaned lambs improved their growth rates, efficiency of gain and enhanced rumen development. Increasing daily ME intake from 1.5 times maintenance to ad libitum at a constant protein to energy ratio did not alter the total chemical body composition of the lambs fed to a fixed LW. Increasing the crude protein content of milk replacer, and therefore the corresponding protein to energy ratio, increased average daily gain and efficiency of gain in lambs. Further, the protein content in the empty bodies of lambs increased whilst fat content decreased. Growth and body composition of lambs were unaffected by altered pellet protein content. The study also showed that lambs fed in excess of their protein and energy requirements reached maximum potential protein deposition rates. Based on a model developed, overestimating the maintenance energy requirements of milk-only fed lambs underestimated their daily fat deposition rates and underestimating the maintenance requirements of lamb offered milk and ad libitum access to pellets over estimated their daily fat deposition. A greater percentage increase in fat deposited in gain increased the energy requirements for gain in the lambs. This study has contributed to the knowledge on rearing lambs artificially with various combinations of milk and pellets. The findings will provide a useful platform for future studies aiming to develop feeding strategies to improve pre-weaning lamb growth

Structured Dependence Modelling:A Bayesian Framework for Data-Driven Validation of Psychometric Measurement Instruments

This thesis presents Structured Dependence Modelling (SDM), a novel Bayesian matrix-based framework developed for the data-driven validation of psychometric instruments. SDM implements a dependence-based representation of the theorized latent variable models that underlie psychometric measurement instruments. Unlike traditional methods such as Item Response Theory (IRT) and Structural Equation Modelling (SEM), the latent variables are not directly modelled. Instead, their anticipated effect on the statistical dependence among exam items, response times, and other psychometric data is specified through a structured variance-covariance matrix. The proposed framework addresses the computational inefficiencies often encountered with current Bayesian matrix-based approaches in psychometric applications, particularly as the latent variable structures grow in complexity. In SDM this issue is tackled with a truncation function for the prior distribution of matrix parameters, dynamically enforcing boundaries to maintain the positive-definiteness of the structured matrix in the multidimensional parameter space. Gibbs-samplers and a gradient-based Hamilton Monte Carlo (HMC) algorithm are developed that scale to complex psychometric models and high-dimensional data. For inference-making with SDMs, objective Bayes factors and posterior credible intervals for matrix parameters are derived. In simulation studies, SDMs outperformed IRT- and SEM-based methods at testing the dimensionality of categorical response and response time data. The results were obtained with sample sizes that are common in data-driven validation studies for the psychometric properties of measurement instruments. Empirical examples demonstrate the applicability of the proposed framework to real-world, hierarchically nested response and process data from digital assessments. The thesis concludes with a reflection on the objectives of my PhD research, assessing the benefits and limitations of the proposed framework and suggesting potential future directions for its development and application

Magnetically Induced Metallic Phase in Superconducting Tantalum Films

We have studied the electronic transport properties of homogeneously disordered superconducting tantalum thin films in magnetic fields. The films exhibit three distinct transport regimes in the zero temperature limit which we identify as superconducting, metallic, and insulating phases. The metallic phase is unexpected. The transport characteristics of this metallic phase are found to be similar to those of MoGe films and high mobility dilute two-dimensional electrons or holes confined in semiconductor interface or transistor geometry.Comment: four pages, four figure

Attention Shaping: a Reward-Based Learning Method to Enhance Skills Training Outcomes in Schizophrenia

Disturbances in sustained attention commonly interfere with the ability of persons with schizophrenia to benefit from evidence-based psychosocial treatments. Cognitive remediation interventions have thus far demonstrated minimal effects on attention, as have medications. There is thus a gap between the existence of effective psychosocial treatments and patients’ ability to effectively engage in and benefit from them. We report on the results of a multisite study of attention shaping (AS), a behavioral intervention for improving attentiveness and learning of social skills among highly distractible schizophrenia patients. Patients with chronic schizophrenia who were refractory to skills training were assigned to receive either the UCLA Basic Conversation Skills Module (BCSM) augmented with AS (n = 47) or in the standard format (n = 35). AS, a reward-based learning procedure, was employed to facilitate patients’ meeting clearly defined and individualized attentiveness and participation goals during each session of a social skills training group. Primary outcome measures were observational ratings of attentiveness in each session and pre- and post-BCSM ratings of social skill and symptoms. Patients receiving social skills training augmented with AS demonstrated significantly more attentiveness in group sessions and higher levels of skill acquisition; moreover, significant relationships were found between changes in attentiveness and amount of skills acquired. Changes in attentiveness were unrelated to level or change in antipsychotic medication dose. AS is an effective example of supported cognition, in that cognitive abilities are improved within the environmental context where the patient is experiencing difficulty, leading to gains in both attention and functional outcome

Contrasting physical properties of black carbon in urban Beijing between winter and summer

Black carbon (BC) is known to have major impacts on both human health and climate. The populated megacity represents the most complex anthropogenic BC emissions where the sources and related impacts are very uncertain. This study provides source attribution and characterization of BC in the Beijing urban environment during the joint UK–China APHH (Air Pollution and Human Health) project, in both winter (November–December 2016) and summer (May–June 2017). The size-resolved mixing state of BC-containing particles was characterized by a single-particle soot photometer (SP2) and their mass spectra was measured by a soot particle aerosol mass spectrometer (SP-AMS). The refractory BC (rBC) mass loading was around a factor of 2 higher in winter relative to summer, and more variable coatings were present, likely as a result of additional surface emissions from the residential sector and favourable condensation in the cold season. The characteristics of the BC were relatively independent of air mass direction in summer, whereas in winter air masses from the Northern Plateau were considerably cleaner and contained less-coated and smaller BC, but the BC from the Southern Plateau had the largest core size and coatings. We compare two online source apportionment methods using simultaneous measurements made by the SP2, which measures physical properties of BC, and the chemical approach using the positive matrix factorization (PMF) of mass spectra from the SP-AMS for the first time. A method is proposed to isolate the BC from the transportation sector using a mode of small BC particles (core diameter Dc0.18 µm and ct  200 nm) to the total rBC mass increased with pollution level in winter but was minor in summer. These large BC particles importantly enhanced the absorption efficiency at high pollution levels – in winter when PM1 > 100 µg m−3 or BC > 2 µg m−3, the absorption efficiency of BC increased by 25 %–70 %. The reduction of emissions of these large BC particles and the precursors of the associated secondary coating will be an effective way of mitigating the heating effect of BC in urban environments

Breast Cancer Risk and Breast-Cancer-Specific Mortality following Risk-Reducing Salpingo-Oophorectomy in BRCA Carriers : A Systematic Review and Meta-Analysis

Funding This research was funded by Rosetrees Trust, grant number CF1\100001, and Barts Charity, grant number ECMG1C3R. The funders had no role in the study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the article for publication.Peer reviewedPublisher PD

Describing Healthcare Service Delivery in a Ryan White Funded HIV Clinic: A Bayesian Mixed Method Case Study

This dissertation describes health care delivery in a Ryan White Program (RWP) HIV clinic, with a focus on medical home care, using the Bayesian Case Study Method (BCSM). The RWP funds medical care for uninsured HIV patients and Pappas and colleagues (2014) suggested enhanced HIV care build upon medical home models of care rooted in the RWP. However, little research describes how RWP clinics operate as medical homes. This study developed the BCSM to describe medical home care at a RWP clinic. The BCSM combines a case study framework with Bayesian statistics for a novel approach to mixed method, descriptive studies. Roberts (2002) and Voils (2009) used mixed-method Bayesian approaches and this dissertation contributes to this work. For this study, clinic staff and patients participated in interviews and surveys. I used Bayes’ Theorem to combine interview data, by use of subjective priors, with survey data to produce Bayesian posterior means that indicate the extent to which medical home care was provided. Subjective priors facilitate the inclusion of valuable stakeholder belief in posteriors. Using the BCSM, posterior means succinctly describe qualitative and quantitative data, in a way other methods of mixing data do not, which is useful for decision makers. Posterior means indicated that coordinated, comprehensive, and ongoing care was provided at the clinic; however, accessible care means were lower reflecting an area in need of improvement. Interview data collected for subjective priors captured detailed service delivery descriptions. For example, interview data described how medical and support services were coordinated and highlighted the role of social determinants of health (SDH). Namely, coordinated and comprehensive services that addressed SDH, such as access to housing, food, and transportation, were necessary for patients to focus on their HIV and utilize healthcare. This case study addressed a gap in the literature regarding descriptions of how RWP clinics provide medical home care. For domains with high posterior means, the associated interview data can be used to plan HIV care in non-RWP settings. Future research should describe other RWP HIV medical homes so this information can be used to plan enhanced HIV care across the healthcare system

Attention Shaping: a Reward-Based Learning Method to Enhance Skills Training Outcomes in Schizophrenia

Disturbances in sustained attention commonly interfere with the ability of persons with schizophrenia to benefit from evidence-based psychosocial treatments. Cognitive remediation interventions have thus far demonstrated minimal effects on attention, as have medications. There is thus a gap between the existence of effective psychosocial treatments and patients’ ability to effectively engage in and benefit from them. We report on the results of a multisite study of attention shaping (AS), a behavioral intervention for improving attentiveness and learning of social skills among highly distractible schizophrenia patients. Patients with chronic schizophrenia who were refractory to skills training were assigned to receive either the UCLA Basic Conversation Skills Module (BCSM) augmented with AS (n = 47) or in the standard format (n = 35). AS, a reward-based learning procedure, was employed to facilitate patients’ meeting clearly defined and individualized attentiveness and participation goals during each session of a social skills training group. Primary outcome measures were observational ratings of attentiveness in each session and pre- and post-BCSM ratings of social skill and symptoms. Patients receiving social skills training augmented with AS demonstrated significantly more attentiveness in group sessions and higher levels of skill acquisition; moreover, significant relationships were found between changes in attentiveness and amount of skills acquired. Changes in attentiveness were unrelated to level or change in antipsychotic medication dose. AS is an effective example of supported cognition, in that cognitive abilities are improved within the environmental context where the patient is experiencing difficulty, leading to gains in both attention and functional outcome