Color Breaking Baryogenesis

We propose a scenario that generates the observed baryon asymmetry of the Universe through a multi--step phase transition in which SU(3) color symmetry is first broken and then restored. A spontaneous violation of $B-L$ conservation leads to a contribution to the baryon asymmetry that becomes negligible in the final phase. The baryon asymmetry is therefore produced exclusively through the electroweak mechanism in the intermediate phase. We illustrate this scenario with a simple model that reproduces the observed baryon asymmetry. We discuss how future electric dipole moment and collider searches may probe this scenario, though future EDM searches would require an improved sensitivity of several orders of magnitude.Comment: Updated to comply with referees suggestions and mirror published versio

Observing the Dimensionality of Our Parent Vacuum

It seems generic to have vacua with lower dimensionality than ours. We consider the possibility that the observable universe originated in a transition from one of these vacua. Such a universe has anisotropic spatial curvature. This may be directly observable through its late-time effects on the CMB if the last period of slow-roll inflation was not too long. These affect the entire sky, leading to correlations which persist up to the highest CMB multipoles, thus allowing a conclusive detection above cosmic variance. Further, this anisotropic curvature causes different dimensions to expand at different rates. This leads to other potentially observable signals including a quadrupolar anisotropy in the CMB which limits the size of the curvature. Conversely, if isotropic curvature is observed it may be evidence that our parent vacuum was at least 3+1 dimensional. Such signals could reveal our history of decompactification, providing evidence for the existence of vastly different vacua.Comment: 30 pages, 2 figures. v2: minor changes to agree with published versio

Social Knowledge and Social Norms

Social knowledge, for the most part, is knowledge through testimony. This essay separates knowledge from justification, characterizes testimony as a source of belief, explains why testimony is a source of knowledge, canvasses arguments for anti-reductionism and for reductionism in the reductionism vs. anti-reductionism debate, addresses counterexamples to knowledge transmission, defends a safe basis account of testimonial knowledge, and turns to social norms as a partial explanation for the reliability of testimony

A review of bovine Johne's disease control activities in 6 endemically infected countries

Mycobacterium avium subspecies paratuberculosis (MAP) is endemic in the bovine populations of many countries and can cause a significant reduction in animal welfare and production efficiency making control desirable. Effective control has proved very difficult to achieve despite multiple regionally coordinated programmes being in existence since the 1920s. The international community increasingly recognises the value in learning from the collective experiences of existing programmes to improve the effectiveness of control. The aim of this review is to outline key aspects of bovine Johne's disease control activities across 6 endemically infected countries to facilitate comparison of current international practice. The background, control activities and monitoring components of programmes in Australia, Canada, Denmark, the Netherlands, the United Kingdom and the United States of America were individually reviewed. Factual accuracy of each review was checked by individuals involved in the respective programmes before the reviews were condensed and combined into a single document presented here, with the complete reviews of each programme available as supplementary material. There was considerable heterogeneity in key aspects of control activity design including goals, responses to declining participation, herd classification, recommended control measures and associated test requirements. The data presented will be of interest to organisations that are involved in developing new or existing regionally coordinated BJD control activities

Does Knowledge Entail Justification?

Robert Audi’s Seeing, Knowing, & Doing argues that knowledge does not entail justification, given a broadly externalist conception of knowledge and an access internalist conception of justification, where justification requires the ability to cite one’s grounds or reasons. On this view, animals and small children can have knowledge while lacking justification. About cases like these and others, Audi concludes that knowledge does not entail justification. But the access internalist sense of “justification” is but one of at least two ordinary senses of the term. On a broader or looser sense, “justification” means “being in the right” where that involves meeting a standard or norm. I argue that the beliefs of animals and small children can then meet standards or norms associated with truth and knowledge such that their beliefs may count as justified in this broader or looser sense. I then question whether knowledge fails to entail justification on this broader sense

Breeding for improved nitrogen use efficiency in oilseed rape

Oilseed rape has a high requirement for nitrogen (N) fertiliser relative to its seed yield. This paper uses published and unpublished work to explore the extent to which the N use efficiency (seed yield ÷ N supply) of oilseed rape could be improved without reducing seed yield. It was estimated that if the concentration of N in the stem and pod wall at crop maturity could be reduced from 1.0 to 0.6%, the root length density increased to 1 cm/cm3 to 100 cm soil depth and the post flowering N uptake increased by 20 kg N/ha then the fertiliser requirement could be reduced from 191 to 142 kg N/ha and the N use efficiency could be increased from 15.2 to 22.4 kg of seed dry matter per kg N. Genetic variation was found for all of the traits that were estimated to be important for N use efficiency. This indicates that there is significant scope for plant breeders to reduce N use efficiency in oilseed rape