Reciprocal regulation of A-to-I RNA editing and the vertebrate nervous system

The fine control of molecules mediating communication in the nervous system is key to adjusting neuronal signaling during development and in maintaining the stability of established networks in the face of altered sensory input. To prevent the culmination of pathological recurrent network excitation or debilitating periods of quiescence, adaptive alterations occur in the signaling molecules and ion channels that control membrane excitability and synaptic transmission. However, rather than encoding (and thus "hardwiring") modified gene copies, the nervous systems of metazoa have opted for expanding on post-transcriptional pre-mRNA splicing by altering key encoded amino acids using a conserved mechanism of A-to-I RNA editing: the enzymatic deamination of adenosine to inosine. Inosine exhibits similar base-pairing properties to guanosine with respect to tRNA codon recognition, replication by polymerases, and RNA secondary structure (i.e.,: forming-capacity). In addition to recoding within the open reading frame, adenosine deamination also occurs with high frequency throughout the non-coding transcriptome, where it affects multiple aspects of RNA metabolism and gene expression. Here, we describe the recoding function of key RNA editing targets in the mammalian central nervous system and their potential to be regulated. We will then discuss how interactions of A-to-I editing with gene expression and alternative splicing could play a wider role in regulating the neuronal transcriptome. Finally, we will highlight the increasing complexity of this multifaceted control hub by summarizing new findings from high-throughput studies. © 2013 Penn, Balik and Greger

Mixed Reality Architecture: a dynamic architectural topology

Architecture can be shown to structure patterns of co-presence and in turn to be structured itself by the rules and norms of the society present within it. This two-way relationship exists in a surprisingly stable framework, as fundamental changes to buildings are slow and costly. At the same time, change within organisations is increasingly rapid and buildings are used to accommodate some of that change. This adaptation can be supported by the use of telecommunication technologies, overcoming the need for co-presence during social interaction. However, often this results in a loss of accountability or ‘civic legibility’, as the link between physical location and social activity is broken. In response to these considerations, Mixed Reality Architecture (MRA) was developed. MRA links multiple physical spaces across a shared 3D virtual world. We report on the design of MRA, including the key concept of the Mixed Reality Architectural Cell, a novel architectural interface between architectural spaces that are remote to each other. An in-depth study lasting one year and involving six office-based MRACells, used video recordings, the analysis of event logs, diaries and an interview survey. This produced a series of ethnographic vignettes describing social interaction within MRA in detail. In this paper we concentrate on the topological properties of MRA. It can be shown that the dynamic topology of MRA and social interaction taking place within it are fundamentally intertwined. We discuss how topological adjacencies across virtual space change the integration of the architectural spaces that MRA is installed in. We further reflect on how the placement of MRA technology in different parts of an office space (deep or shallow) impacts on the nature of that particular space. Both the above can be shown to influence movement through the building and social interaction taking place within it. These findings are directly relevant to new buildings that need to be designed to accommodate organisational change in future but also to existing building stock that might be very hard to adapt. We are currently expanding the system to new sites and are planning changes to the infrastructure of MRA as well as its interactional interface

Spin Waves in Ferromagnetic Metals and the Dynamical Form of the Landau Quasi-particle Theory

Spin waves in ferromagnetic metals dynamical form of Landau quasi-particle theor

Mixed Reality Architecture: Concept, Construction, Use

Mixed Reality Architecture (MRA) dynamically links and overlays physical and virtual spaces. This paper investigates the topology of and the relationships between the components of MRA. As a phenomenon, MRA takes its place in a long history of technologies that have influenced conditions for social interaction as well as the environment we build around us. However, by providing a flexible spatial topology spanning physical and virtual environments it presents new opportunities for social interaction across electronic media. An experimental MRA is described that allowed us to study some of the emerging issues in this field. It provided material for the development of a framework describing virtual and physical spaces, the links between those and the types of mixed reality structure that we can envisage it being possible to design using these elements. We propose that by re-introducing a level of spatiality into communication across physical and virtual environments MRA will support everyday social interaction, and may convert digital communication media from being socially conservative to a more generative form familiar from physical space

Studies on Ciliates from Mollusks of Iowa

The ciliates which live a commensal life on the gills and in the mantle cavities of mollusks include several species of peritrichs, but most of them belong to a suborder of holotrichs called Thigmotricha (Chatton and Lwoff, 1922). Very little work has been done on the geographical distribution and host-specificity of the ciliates of mollusks. Emphasis has been placed rather upon the taxonomic and morphological features

Food Commercials and Kids: Characterizing Advertising Content of Children's Online Television Programs

Internet marketing has gained attention as a new medium to advertise food products to children. This study examines the prevalence of food marketing during children's television programs that are available on the internet. While food is the largest product category advertised, commercials make up a smaller portion of episode time online compared to previous reports of television advertising.Internet Food Marketing, Childhood Obesity, Content Analysis, Food Consumption/Nutrition/Food Safety, Marketing,

Post-Meiotic Intra-Testicular Sperm Senescence in a Wild Vertebrate

There is growing interest in sperm senescence, both in its underlying mechanisms and evolutionary consequences, because it can impact the evolution of numerous life history traits. Previous studies have documented various types of sperm senescence, but evidence of post-meiotic intra-testicular sperm senescence in wild animals is lacking. To assess such senescence, we studied within-season changes in sperm motility in the common toad (Bufo bufo), where males produce all sperm prior to the breeding season. We found that males exposed to experimentally induced re-hibernation at the start of the breeding season, that is to experimentally lowered metabolic rates, stored sperm of significantly higher motility than males that were kept under seminatural conditions without females throughout the breeding season. This finding indicates that re-hibernation slows normal rates of sperm ageing and constitutes the first evidence to our knowledge of post-meiotic intra-testicular sperm senescence in a wild vertebrate. We also found that in males kept in seminatural conditions, sperm motility was positively related to the number of matings a male achieved. Thus, our results suggest that post-meiotic intratesticular sperm senescence does not have a genetically fixed rate and may be modulated by temperature and possibly by mating opportunities