Do the Subjective Visual Vertical and the Subjective Haptic Vertical Probe a Common Estimate of Gravitational Upright?

In the subjective visual vertical (SVV) and the subjective haptic vertical (SHV) task, participants must judge the alignment of a probe rod with perceived gravitational vertical by sight or by touch. Previous research suggests that as the body is roll-tilted, SVV and SHV show a systematic, distinct pattern of errors, although reports vary. The purpose of this research was to identify whether SVV and SHV probe the same underlying representation of gravity. In Experiment 1, I confirmed that SVV and SHV errors are divergent by comparing the two measures in the same participants. In Experiment 2, I varied the tilt of the head and body separately and applied galvanic vestibular stimulation to introduce vestibular noise. I found these manipulations had differential effects on SVV and SHV. Experiment 3 showed that when neck afferents were stimulated, SVV and SHV integrate optimally, pointing to two distinct underlying estimates of gravity vertical

Where Are Your Fingers?

How do we know how our fingers are oriented in space? Contributions to limb and finger perception include afferent sensory signals from the muscles, joints, skin, as well as vision and other senses, and top-down assumptions about the bodys dimensions. A growing body of literature has examined the perception of finger and hand position and dimensions in a bid to understand how the limbs are represented in the brain. However, no studies have examined perception of the orientation of the fingers. A comprehensive model of highly articulated body parts must include perception of their orientation as well as their position. This dissertation seeks to fill an existing gap in the literature by exploring contributions to finger orientation perception, using a novel line-matching task. In Chapter 3 I provide evidence that vestibular disruption using galvanic vestibular stimulation (GVS) leads to an inward rotation of perceived finger orientation, and provide some evidence that finger orientation perception may not be accurate at baseline. In Chapter 4 I show that left- and right-handers may have differ- ent strategies for finger orientation perception, and provide evidence for an outward rotational bias that increases as the hands are placed further laterally from the body midline. In Chapter 5, I show that the way the probe line is initially displayed has a significant impact on performance, specifically on asymmetries of responses for the two hands and the compression of responses across the test range. I further show that the outward bias observed in Chapter 4 might be due to order of hand placement and differences in muscle strain across conditions. In Chapters 6 and 7, I show no difference in orientation perception for the ring and index fingers, but find an overall inward rotation of orientation estimates for palm-down hand postures, compared to palm-up postures. My research clearly shows that perceived finger orientation, as measured in my line-matching paradigm, is highly context-dependent. I discuss this in the greater context of the limb perception literature and outline some of the questions which much still be addressed in order to arrive at a comprehensive model of hand and finger perception

Digital Three-Dimensional Atlas of Quail Development Using High-Resolution MRI

We present an archetypal set of three-dimensional digital atlases of the quail embryo based on microscopic magnetic resonance imaging (µMRI). The atlases are composed of three modules: (1) images of fixed ex ovo quail, ranging in age from embryonic day 5 to 10 (e05 to e10); (2) a coarsely delineated anatomical atlas of the µMRI data; and (3) an organ system–based hierarchical graph linked to the anatomical delineations. The atlas is designed to be accessed using SHIVA, a free Java application. The atlas is extensible and can contain other types of information including anatomical, physiological, and functional descriptors. It can also be linked to online resources and references. This digital atlas provides a framework to place various data types, such as gene expression and cell migration data, within the normal three-dimensional anatomy of the developing quail embryo. This provides a method for the analysis and examination of the spatial relationships among the different types of information within the context of the entire embryo

Seroprevalence of rubella antibodies and determinants of susceptibility to rubella in a cohort of pregnant women in Canada, 2008–2011

Long term control of rubella and congenital rubella syndrome relies on high population-level immunity against rubella, particularly among women of childbearing age. In Canada, all pregnant women should be screened so that susceptible new mothers can be offered vaccination for rubella before discharge. This study was undertaken to estimate rubella susceptibility in a cohort of pregnant women in Canada and to identify associated socio-economic and demographic factors. Biobanked plasma samples were obtained from the Maternal-Infant Research on Environmental Chemicals (MIREC) study, in which pregnant women were recruited between 2008 and 2011. Socio-demographic characteristics and obstetric histories were collected. Second trimester plasma samples (n = 1,752) were tested for rubella-specific IgG using an in-house enzyme-linked immunosorbent assay. The percentage of women with IgG titers <5 IU/mL, 5–10 IU/mL, and 10 IU/mL were 2.3%, 10.1%, and 87.6%, respectively. Rates of seronegativity, defined as <5 IU/mL, were 3.1% in women who had no previous live birth and 1.6% in women who had given birth previously. Among the latter group, seronegativity was higher in women with high school education or less (adjusted OR (aOR) 5.93, 95% CI 2.08–16.96) or with a college or trade school diploma (aOR 3.82, 95% CI 1.45–10.12), compared to university graduates, and those born outside Canada (aOR 2.60, 95% CI 1.07–6.31). In conclusion, a large majority of pregnant women were found to be immune to rubella. Further research is needed to understand inequalities in vaccine uptake or access, and more effort is needed to promote catch-up measles-mumps-rubella vaccination among socioeconomically disadvantaged and immigrant women of childbearing age

Most Likely Transformations

We propose and study properties of maximum likelihood estimators in the class of conditional transformation models. Based on a suitable explicit parameterisation of the unconditional or conditional transformation function, we establish a cascade of increasingly complex transformation models that can be estimated, compared and analysed in the maximum likelihood framework. Models for the unconditional or conditional distribution function of any univariate response variable can be set-up and estimated in the same theoretical and computational framework simply by choosing an appropriate transformation function and parameterisation thereof. The ability to evaluate the distribution function directly allows us to estimate models based on the exact likelihood, especially in the presence of random censoring or truncation. For discrete and continuous responses, we establish the asymptotic normality of the proposed estimators. A reference software implementation of maximum likelihood-based estimation for conditional transformation models allowing the same flexibility as the theory developed here was employed to illustrate the wide range of possible applications.Comment: Accepted for publication by the Scandinavian Journal of Statistics 2017-06-1

The impact of advertising patient and public involvement on trial recruitment: embedded cluster randomised recruitment trial

BACKGROUND Patient and public involvement in research (PPIR) may improve trial recruitment rates, but it is unclear how. Where trials use PPIR to improve design and conduct, many do not communicate that clearly to potential participants. Better communication of PPIR might encourage patient enrolment, as trials may be perceived as more socially valid, relevant, and trustworthy. We aimed to evaluate the impact on recruitment of directly advertising PPIR to potential trial participants. METHODS A cluster trial, embedded within a host trial ('EQUIP') recruiting service users diagnosed with severe mental illness. The intervention was informed by a systematic review, a qualitative study, social comparison theory and a stakeholder workshop including service users and carers. Adopting Participatory Design approaches, we co-designed the recruitment intervention with PPIR partners using a leaflet to advertise the PPIR in EQUIP and sent potential participants invitations with the leaflet (intervention group) or not (control group). Primary outcome was the proportion of patients enrolled in EQUIP. Secondary outcomes included the proportions of patients who positively responded to the trial invitation. RESULTS 34 community mental health teams were randomised and 8182 service users invited. For the primary outcome, 4% of patients in the PPIR group were enrolled versus 5.3% of the control group. The intervention was ineffective for improving recruitment rates (adjusted OR= 0.75, 95% CI= 0.53 to 1.07, p=0.113). For the secondary outcome of positive response, the intervention was not effective, with 7.3% of potential participants in the intervention group responding positively versus 7.9% of the control group (adjusted OR=0.74, 95% CI= 0.53 to 1.04, p=0.082). We did not find a positive impact of directly advertising PPIR on any other outcomes. CONCLUSION To our knowledge, this is the largest ever embedded trial to evaluate a recruitment or PPIR intervention. Advertising PPIR did not improve enrolment rates, or any other outcome. It is possible that rather than advertising PPIR being the means to improve recruitment, PPIR may have an alternative impact on trials by making them more attractive, acceptable and patient-centred. We discuss potential reasons for our findings and implications for recruitment practice and research

Population-specific gene expression responses to hybridization between farm and wild Atlantic salmon

Because of intrinsic differences in their genetic architectures, wild populations invaded by domesticated individuals could experience population-specific consequences following introgression by genetic material of domesticated origin. Expression levels of 16 000 transcripts were quantified by microarrays in liver tissue from farm, wild, and farm-wild backcross (i.e. F1 farm-wild hybrid × wild; total n = 50) Atlantic salmon (Salmo salar) raised under common environmental conditions. The wild populations and farm strain originated from three North American rivers in eastern Canada (Stewiacke, Tusket, and Saint John rivers, respectively). Analysis of variance revealed 177 transcripts with different expression levels among the five strains compared. Five times more of these transcripts were differentiated between farmed parents and Tusket backcrosses (n = 53) than between Stewiacke backcrosses and their farmed parents (n = 11). Altered biological processes in backcrosses also differed between populations both in number and in the type of processes impacted (metabolism vs immunity). Over-dominant gene expression regulation in backcrosses varied considerably between populations (23% in Stewiacke vs 44% in Tusket). Hence, the consequences of introgression of farm genetic material on gene expression depended on population-specific genetic architectures. These results support the need to evaluate impacts of farm-wild genetic interactions at the population scale

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Advancing the research agenda on food systems governance and transformation

The food systems upon which humanity depends face multiple interdependent environmental, social and economic threats in the 21st Century. Yet, the governance of these systems, which determines to a large extent the ability to adapt and transform in response to these challenges, is underresearched. This perspective piece synthesises the findings of two recent reviews of food systems governance and transformations and proposes a comprehensive research agenda for the coming years. These reviews highlight the influence of governance on food systems, methodological obstacles to explaining the effectiveness of governance in realising food sustainability, and conditions that have historically supported food system transformations. We argue that the following steps are key to improving our knowledge of the role of governance in food systems: (1) developing more comparable research designs for building generalisable explanations of the governance elements that are most effective in realising food systems goals; (2) using the lens of polycentricity to help disentangle complex governance networks; (3) giving greater attention to the conditions and pre-conditions associated with historical food system transformations; (4) identifying adaptations that strengthen or weaken path dependency; and, (5) focusing research on how transformations can be supported by institutions that facilitate collective action and stakeholder agency

Highs and Lows of Sympathetic Neuro-cardiovascular Transduction: Influence of Altitude Acclimatization and Adaptation

High-altitude (>2500m) exposure results in increased muscle sympathetic nervous activity (MSNA) in acclimatizing lowlanders. However, little is known about how altitude affects MSNA in 66 indigenous high-altitude populations. Additionally, the relationship between MSNA and blood 67 pressure regulation (i.e., neurovascular transduction) at high-altitude is unclear. We sought to 68 determine 1) how high-altitude effects neuro-cardiovascular transduction and 2) whether 69 differences exist in neuro-cardiovascular transduction between low and high-altitude 70 populations. Measurements of MSNA (microneurography), mean arterial blood pressure (MAP; 71 finger photoplethysmography), and heart rate (electrocardiogram) were collected in: I) 72 lowlanders (n=14) at low (344m) and high-altitude (5050m), II) Sherpa highlanders (n=8; 73 5050m), and III) Andean (with and without excessive erythrocytosis) highlanders (n=15; 74 4300m). Cardiovascular responses to MSNA burst sequences (i.e. singlet, couplet, triplet, and 75 quadruplets) were quantified using custom software (coded in MATLAB, v2015b). Slopes were 76 generated for each individual based on peak responses and normalized total MSNA. High 77 altitude reduced neuro-cardiovascular transduction in lowlanders (MAP slope: high-altitude, 78 0.0075±0.0060 vs low-altitude, 0.0134±0.080; p=0.03). Transduction was elevated in Sherpa 79 (MAP slope, 0.012±0.007) compared to Andeans (0.003±0.002; p=0.001). MAP transduction 80 was not statistically different between acclimatizing lowlanders and Sherpa (MAP slope, p=0.08) 81 or Andeans (MAP slope, p=0.07). When accounting for resting MSNA (ANCOVA), transduction 82 was inversely related to basal MSNA (bursts/min) independent of population (RRI, r= 0.578 83 p<0.001; MAP, r= -0.627 p<0.0001). Our results demonstrate transduction is blunted in 84 individuals with higher basal MSNA, suggesting blunted neuro-cardiovascular transduction is a 85 physiological adaptation to elevated MSNA rather than an effect or adaptation specific to 86 chronic hypoxic exposure