A canadian field test of finnish ayrshires: growth and reproductive performance

International audienc

A generic method for estimating and smoothing multispecies biodiversity indices using intermittent data

Biodiversity indicators summarise extensive, complex ecological data sets and are important in influencing government policy. Component data consist of time-varying indices for each of a number of different species. However, current biodiversity indicators suffer from multiple statistical shortcomings. We describe a state-space formulation for new multispecies biodiversity indicators, based on rates of change in the abundance or occupancy probability of the contributing individual species. The formulation is flexible and applicable to different taxa. It possesses several advantages, including the ability to accommodate the sporadic unavailability of data, incorporate variation in the estimation precision of the individual species’ indices when appropriate, and allow the direct incorporation of smoothing over time. Furthermore, model fitting is straightforward in Bayesian and classical implementations, the latter adopting either efficient Hidden Markov modelling or the Kalman filter. Conveniently, the same algorithms can be adopted for cases based on abundance or occupancy data—only the subsequent interpretation differs. The procedure removes the need for bootstrapping which can be prohibitive. We recommend which of two alternatives to use when taxa are fully or partially sampled. The performance of the new approach is demonstrated on simulated data, and through application to three diverse national UK data sets on butterflies, bats and dragonflies. We see that uncritical incorporation of index standard errors should be avoided

UK experience of liver transplantation for erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is characterised by excess production of free protoporphyrin from the bone marrow, most commonly due to deficiency of the enzyme ferrochelatase. Excess protoporphyrin gives rise to the cutaneous photosensitivity characteristic of the disease, and in a minority of patients leads to end-stage liver disease necessitating liver transplantation (LT). There is limited information regarding the timing, impact and long-term outcome of LT in such patients, thus we aimed to identify the indications and outcomes of all transplants performed for EPP in the UK using data from the UK Transplant Registry. Between 1987 and 2009, five patients underwent LT for EPP liver disease. Median follow-up was 60 months, and there were two deaths at 44 and 95 months from causes unrelated to liver disease. The remaining recipients are alive at 22.4 years, 61 months and 55 months after transplant. A high rate of postoperative biliary stricturing requiring multiple biliary interventions was observed. Recurrent EPP-liver disease occurred in 4/5 (80%) of patients but graft failure has not been observed. Given the role of biliary obstruction in inducing EPP-mediated liver damage, we suggest that consideration should be given for construction of a Roux loop at the time of transplant. Thus we demonstrate that although EPP liver transplant recipients have a good long-term survival, comparable to patients undergoing LT for other indications, biliary complications and disease recurrence are almost universal, and bone marrow transplantation should be considered where possible

Size and shape constancy in consumer virtual reality

With the increase in popularity of consumer virtual reality headsets, for research and other applications, it is important to understand the accuracy of 3D perception in VR. We investigated the perceptual accuracy of near-field virtual distances using a size and shape constancy task, in two commercially available devices. Participants wore either the HTC Vive or the Oculus Rift and adjusted the size of a virtual stimulus to match the geometric qualities (size and depth) of a physical stimulus they were able to refer to haptically. The judgments participants made allowed for an indirect measure of their perception of the egocentric, virtual distance to the stimuli. The data show under-constancy and are consistent with research from carefully calibrated psychophysical techniques. There was no difference in the degree of constancy found in the two headsets. We conclude that consumer virtual reality headsets provide a sufficiently high degree of accuracy in distance perception, to allow them to be used confidently in future experimental vision science, and other research applications in psychology

Anti-müllerian hormone is not associated with cardiometabolic risk factors in adolescent females

<p>Objectives: Epidemiological evidence for associations of Anti-Müllerian hormone (AMH) with cardiometabolic risk factors is lacking. Existing evidence comes from small studies in select adult populations, and findings are conflicting. We aimed to assess whether AMH is associated with cardiometabolic risk factors in a general population of adolescent females.</p> <p>Methods: AMH, fasting insulin, glucose, HDLc, LDLc, triglycerides and C-reactive protein (CRP) were measured at a mean age 15.5 years in 1,308 female participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Multivariable linear regression was used to examine associations of AMH with these cardiometabolic outcomes.</p> <p>Results: AMH values ranged from 0.16–35.84 ng/ml and median AMH was 3.57 ng/ml (IQR: 2.41, 5.49). For females classified as post-pubertal (n = 848) at the time of assessment median (IQR) AMH was 3.81 ng/ml (2.55, 5.82) compared with 3.25 ng/ml (2.23, 5.05) in those classed as early pubertal (n = 460, P≤0.001). After adjusting for birth weight, gestational age, pubertal stage, age, ethnicity, socioeconomic position, adiposity and use of hormonal contraceptives, there were no associations with any of the cardiometabolic outcomes. For example fasting insulin changed by 0% per doubling of AMH (95%CI: −3%,+2%) p = 0.70, with identical results if HOMA-IR was used. Results were similar after additional adjustment for smoking, physical activity and age at menarche, after exclusion of 3% of females with the highest AMH values, after excluding those that had not started menarche and after excluding those using hormonal contraceptives.</p> <p>Conclusion: Our results suggest that in healthy adolescent females, AMH is not associated with cardiometabolic risk factors.</p&gt

Using equity premium survey data to estimate future wealth

We present the first systematic methods for combining different experts' responses to equity premium surveys. These techniques are based on the observation that the survey data are approximately gamma distributed. This distribution has convenient analytical properties that enable us to address three important problems that investment managers must face. First, we construct probability density functions for the future values of equity index tracker funds. Second, we calculate unbiased and minimum least square error estimators of the future value of these funds. Third, we derive optimal asset allocation weights between equities and the risk-free asset for risk-averse investors. Our analysis allows for both herding and biasedness in expert responses. We show that, unless investors are highly uncertain about expert biases or forecasts are very highly correlated, many investment decisions can be based solely on the mean of the survey data minus any expected bias. We also make recommendations for the design of future equity premium surveys

Caste-specific demography and phenology in bumblebees; modelling BeeWalk data

We present novel dynamic mixture models for the monitoring of bumblebee populations on an unprecedented geographical scale, motivated by the UK citizen science scheme BeeWalk. The models allow us for the First time to estimate bumblebee phenology and within-season productivity, defined as the number of individuals in each caste per colony in the population in that year, from citizen science data. All of these parameters are estimated separately for each caste, giving a means of considerable ecological detail in examining temporal changes in the complex life-cycle of a social insect in the wild. Due to the dynamic nature of the models, we are able to produce population trends for a number of UK bumblebee species using the available time-series. Via an additional simulation exercise, we show the extent to which useful information will increase if the survey continues, and expands in scale, as expected. Bumblebees are extraordinarily important components of the ecosystem, providing pollination services of vast economic impact and functioning as indicator species for changes in climate or land-use. Our results demonstrate the changes in both phenology and productivity between years and provide an invaluable tool for monitoring bumblebee populations, many of which are in decline, in the UK and around the world

African Americans, Gentrification, and Neoliberal Urbanization: the Case of Fort Greene, Brooklyn

This article examines the gentrification of Fort Greene, which is located in the western part of black Brooklyn, one of the largest contiguous black urban areas in the USA. Between the late 1960s and 2003, gentrification in Fort Greene followed the patterns discovered by scholars of black neighborhoods; the gentrifying agents were almost exclusively black and gentrification as a process was largely bottom-up because entities interested in the production of space were mostly not involved. Since 2003, this has changed. Whites have been moving to Fort Greene in large numbers and will soon represent the numerical majority. Public and private interventions in and around Fort Greene have created a new top-down version of gentrification, which is facilitating this white influx. Existing black residential and commercial tenants are replaced and displaced in the name of urban economic development