Feed represents a substantial proportion of production costs in the dairy industry and is a useful target for improving overall system efficiency and sustainability. The objective of this study was to develop methodology to estimate the economic value for a feed efficiency trait and the associated methane production relevant to Canada. The approach quantifies the level of economic savings achieved by selecting animals that convert consumed feed into product while minimizing the feed energy used for inefficient metabolism, maintenance and digestion. We define a selection criterion trait called Feed Performance (FP) as a 1 kg increase in more efficiently used feed in a first parity lactating cow. The impact of a change in this trait on the total lifetime value of more efficiently used feed via correlated selection responses in other life stages is then quantified. The resulting improved conversion of feed was also applied to determine the resulting reduction in output of emissions (and their relative value based on a national emissions value) under an assumption of constant methane yield, where methane yield is defined as kg methane/kg dry matter intake (DMI). Overall, increasing the FP estimated breeding value by one unit (i.e. 1 kg of more efficiently converted DMI during the cow’s first lactation) translates to a total lifetime saving of 3.23 kg in DMI and 0.055 kg in methane with the economic values of CAD $0.82 and CAD $0.07, respectively. Therefore, the estimated total economic value for FP is CAD $0.89/unit. The proposed model is robust and could also be applied to determine the economic value for feed efficiency traits within a selection index in other production systems and countries.

Objectives: Previous research has demonstrated an association between emotion recognition and apathy in several neurological conditions involving fronto-striatal pathology, including Parkinson’s disease and brain injury. In line with these findings, we aimed to determine whether apathetic participants with early Huntington’s disease (HD) were more impaired on an emotion recognition task compared to non-apathetic participants and healthy controls. Methods: We included 43 participants from the TRACK-HD study who reported apathy on the Problem Behaviours Assessment – short version (PBA-S), 67 participants who reported no apathy, and 107 controls matched for age, sex, and level of education. During their baseline TRACK-HD visit, participants completed a battery of cognitive and psychological tests including an emotion recognition task, the Hospital Depression and Anxiety Scale (HADS) and were assessed on the PBA-S. Results: Compared to the non-apathetic group and the control group, the apathetic group were impaired on the recognition of happy facial expressions, after controlling for depression symptomology on the HADS and general disease progression (Unified Huntington’s Disease Rating Scale total motor score). This was despite no difference between the apathetic and non-apathetic group on overall cognitive functioning assessed by a cognitive composite score. Conclusions: Impairment of the recognition of happy expressions may be part of the clinical picture of apathy in HD. While shared reliance on frontostriatal pathways may broadly explain associations between emotion recognition and apathy found across several patient groups, further work is needed to determine what relationships exist between recognition of specific emotions, distinct subtypes of apathy and underlying neuropathology. (JINS, 2019, 25, 453–461)

Applying high-resolution electron backscatter diffraction (HR-EBSD) to materials without regions that are amenable to the acquisition of backgrounds for static flat fielding (background subtraction) can cause analysis problems. To address this difficulty, the efficacy of electron beam induced deposition (EBID) of material as a source for an amorphous background signal is assessed and found to be practical. Using EBID material for EBSD backgrounds allows single crystal and large-grained samples to be analyzed using HR-EBSD for strain and small angle rotation measurement.

In the first part of this paper we define a partial ordering on the set of all homogeneous identities and find necessary and sufficient conditions that an identity does not imply any identity lower than it in the partial ordering (we call such an identity irreducible). Perhaps the most interesting property established for irreducible identities is that they are skew-symmetric in any two variables of the same odd degree and symmetric in any two variables of the same even degree. The results of the first section are applied to commutative algebras in the remainder of the paper.

The main result of this paper is the following.

Theorem 1. Let A be a simple, commutative, finite-dimensional algebra containing an idempotent over a field of characteristic 0, and let the algebra A' obtained from A by adjoining a unity element satisfy an identity of degree ≦ 4 not implied by commutativity. Then either A is a Jordan algebra or A is two-dimensional over an appropriate field E.

We use simultaneous multi-wavelength BVRI-JHK photometric observations of cataclysmic variables (CVs) to determine the inclination angles of the systems, together with phase-resolved spectroscopy to calculate the K2 and vsini. We then calculate the masses of the system components. We are using these data to construct mass-radius diagrams of the secondaries in an effort to resolve some of the debate over their evolutionary history.

We combine HST and ground-based parallaxes for cataclysmic variables (CVs) to examine their outburst energetics, as well as the nature of their secondary stars. Harrison et al. (2004) have recently published parallaxes for WZ Sge, YZ Cnc, and RU Peg, and have reanalyzed the HST parallaxes for U Gem, SS Aur, and SS Cyg. Combined with existing HST parallaxes for RW Tri (MeArthur et al. 1999), TV Col (MeArthur et al. 2001), EX Hya and V1223 Sgr (Beuermann et al. 2004a,b), ten high-quality parallaxes are available to constrain the various types of outbursts of CVs. In addition, Thorstensen (2003) has published ground-based parallaxes for fourteen CV systems.

We report the breeding success of four species of burrow-nesting petrels at sub-Antarctic Marion Island where house mice Mus musculus are the sole introduced mammal. Feral cats Felis catus were present on Marion for four decades from 1949, killing millions of seabirds and greatly reducing petrel populations. Cats were eradicated by 1991, but petrel populations have shown only marginal recoveries. We hypothesize that mice are suppressing their recovery through depredation of petrel eggs and chicks. Breeding success for winter breeders (grey petrels Procellaria cinerea (34±21%) and great-winged petrels Pterodroma macroptera (52±7%)) were lower than for summer breeders (blue petrels Halobaena caerulea (61±6%) and white-chinned petrels Procellaria aequinoctialis (59±6%)) and among winter breeders most chick fatalities were of small chicks up to 14 days old. We assessed the extent of mouse predation by monitoring the inside of 55 burrow chambers with video surveillance cameras (4024 film days from 2012–16) and recorded fatal attacks on grey (3/18 nests filmed, 17%) and great-winged petrel chicks (1/19, 5%). Our results show that burrow-nesting petrels are at risk from mouse predation, providing further motivation for the eradication of mice from Marion Island.

In 2011 the Incidence Assay Critical Path Working Group reviewed the current state of HIV incidence assays and helped to determine a critical path to the introduction of an HIV incidence assay. At that time the Consortium for Evaluation and Performance of HIV Incidence Assays (CEPHIA) was formed to spur progress and raise standards among assay developers, scientists and laboratories involved in HIV incidence measurement and to structure and conduct a direct independent comparative evaluation of the performance of 10 existing HIV incidence assays, to be considered singly and in combinations as recent infection test algorithms. In this paper we report on a new framework for HIV incidence assay evaluation that has emerged from this effort over the past 5 years, which includes a preliminary target product profile for an incidence assay, a consensus around key performance metrics along with analytical tools and deployment of a standardized approach for incidence assay evaluation. The specimen panels for this evaluation have been collected in large volumes, characterized using a novel approach for infection dating rules and assembled into panels designed to assess the impact of important sources of measurement error with incidence assays such as viral subtype, elite host control of viraemia and antiretroviral treatment. We present the specific rationale for several of these innovations, and discuss important resources for assay developers and researchers that have recently become available. Finally, we summarize the key remaining steps on the path to development and implementation of reliable assays for monitoring HIV incidence at a population level.