States of ignorance and ignorance of states: Examining the Quantum Principal Principle

Earman (2018) has recently argued that the Principal Principle, a principle of rationality connecting objective chance and credence, is a theorem of quantum probability theory. This paper critiques Earman's argument, while also offering a positive proposal for how to understand the status of the Principal Principle in quantum probability theory.     

Mutations in a gene encoding a new oxygen-regulated photoreceptor protein cause dominant retinitis pigmentosa.

The autosomal dominant retinitis pigmentosa (RP) locus, designated RP1, has been mapped through linkage studies to a 4-cM interval at 8q11-13. Here we describe a new photoreceptor-specific gene that maps in this interval and whose expression is modulated by retinal oxygen levels in vivo. This gene consists of at least 4 exons that encode a predicted protein of 2,156 amino acids. A nonsense mutation at codon 677 of this gene is present in approximately 3% of cases of dominant RP in North America. We also detected two deletion mutations that cause frameshifts and introduce premature termination codons in three other families with dominant RP. Our data suggest that mutations in this gene cause dominant RP, and that the encoded protein has an important but unknown role in photoreceptor biology.     

Defending the genome from the enemy within: mechanisms of retrotransposon suppression in the mouse germline

The viability of any species requires that the genome is kept stable as it is transmitted from generation to generation by the germ cells. One of the challenges to transgenerational genome stability is the potential mutagenic activity of transposable genetic elements, particularly retrotransposons. There are many different types of retrotransposon in mammalian genomes, and these target different points in germline development to amplify and integrate into new genomic locations. Germ cells, and their pluripotent developmental precursors, have evolved a variety of genome defence mechanisms that suppress retrotransposon activity and maintain genome stability across the generations. Here, we review recent advances in understanding how retrotransposon activity is suppressed in the mammalian germline, how genes involved in germline genome defence mechanisms are regulated, and the consequences of mutating these genome defence genes for the developing germline.     

Effect of partition coefficient on microsegregation during solidification of aluminium alloys

In the modeling of microsegregation, the partition coefficient is usually calculated using data from the equilibrium phase diagrams. The aim of this study was to experimentally and theoretically analyze the partition coefficient in binary aluminum-copper alloys. The samples were analyzed by differential thermal analysis (DTA), which were melted and quenched from different temperatures during solidification. The mass fraction and composition of phases were measured by image processing and scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectroscopy (EDS) unit. These data were used to calculate as the experimental partition coefficients with four different methods. The experimental and equilibrium partition coefficients were used to model the concentration profile in the primary phase. The modeling results show that the profiles calculated by the experimental partition coefficients are more consistent with the experimental profiles, compared to those calculated using the equilibrium partition coefficients.     

Developing Managers as Healing Agents in Organizations: A Co-Operative Inquiry Approach

This action research examines how a health service manager, with a clinical background, sought to develop his clinical skills in a management context. When asked to undertake an evaluation of an addiction counseling service, he found that there was evidence of systemic ill-health expressed through feelings of powerlessness, hurt, and alienation among the staff of the service. The article describes how the manager used action research, and in particular co-operative inquiry, to become an agent of healing in his own place of work. It illustrates how the co-operative inquiry process can be used to help individuals or groups to overcome feelings of alienation and powerlessness in organizations. By dealing with these feelings through a process of co-operative inquiry the conditions necessary to improve systemic health can be created to help develop a service and meet service objectives It explores the neglected subject of how managers can be agents of healing in organizations.     

Effects of artificial shading on distribution and abundance of juvenile chinook salmon ( Oncorhynchus tshawytscha )

The influence of artificial shade on the distribution and abundance of juvenile chinook salmon was studied in a side channel of the South Fork Salmon River, Idaho. Fish biomass and abundance were greater in shaded than in unshaded areas when compared to both cumulative incident light reaching the study sections during the 72-hour test runs and instantaneous incident light conditions at the end of the 72-hour test runs. Because conditions may be atypical at the time of instantaneous light measurement, we prefer cumulative incident light for relating light and shade conditions to daytime distribution (abundance and biomass) of juvenile chinook salmon.