Protein-RNA interactions: a structural analysis

A detailed computational analysis of 32 protein-RNA complexes is presented. A number of physical and chemical properties of the intermolecular interfaces are calculated and compared with those observed in protein-double-stranded DNA and protein-single-stranded DNA complexes. The interface properties of the protein-RNA complexes reveal the diverse nature of the binding sites. van der Waals contacts played a more prevalent role than hydrogen bond contacts, and preferential binding to guanine and uracil was observed. The positively charged residue, arginine, and the single aromatic residues, phenylalanine and tyrosine, all played key roles in the RNA binding sites. A comparison between protein-RNA and protein-DNA complexes showed that whilst base and backbone contacts (both hydrogen bonding and van der Waals) were observed with equal frequency in the protein-RNA complexes, backbone contacts were more dominant in the protein-DNA complexes. Although similar modes of secondary structure interactions have been observed in RNA and DNA binding proteins, the current analysis emphasises the differences that exist between the two types of nucleic acid binding protein at the atomic contact level

Self-Employment and Risk Preference

We explore the relationship between self-employment and attitudes towards financial risk using individual level data drawn from the U.S. Survey of Consumer Finances (SCF) and the U.S. Panel Study of Income Dynamics (PSID). Both surveys include questions, which enable us to construct measures of an individual´s willingness to take risk allowing us to explore the implications of interpersonal differences in risk preference for the probability and success of self-employment. Our empirical findings suggest that willingness to take financial risk is positively associated with both the incidence and success of self-employment. We find that this relationship is particularly pronounced in cases where the individual actually started the business. Finally, we exploit the panel aspect of the PSID and find evidence consistent with a causal relationship between attitudes towards risk and self-employment with attitudes towards risk measured over 1969-1972 (i.e. prior to becoming self-employed) having a statistically significant positive influence on the probability of self-employment in 1996

Cognitive support for older people from multimedia options

If older users of multimedia displays could select among presentation options, would they choose display combinations that supported their performance? After three short touch-screen tasks which measured the perceptual and cognitive abilities of 50 older adults, they answered questions about a route on an online map that could be accompanied by written and/or spoken text. Half the participants saw animated routes; and they were less accurate answering questions than those who saw static routes but this did not affect people’s multimedia choices which, although diverse, were systematic. Spoken text was more often selected by people who had lower scores on the spatial working memory task, than by the older adults with higher scores. This suggests that older people with cognitive limitations recognise ways in which multimedia information can be supportive

Effects of focal frontal lesions on response inhibition

This study examined the performance of 38 normal subjects and 43 patients with focal lesions of the frontal lobes on a simple go-nogo task where the probability of the nogo stimulus was either 75% or 25%. Patients with lesions to the superior medial parts of the frontal lobes, in particular to the left superior portion of Brodmann area 6 (which includes the supplementary motor areas and the premotor areas for the right hand) had an increased number of false alarms (incorrect responses to the nogo stimulus). These results indicate that area 6 is specifically involved in the inhibition of response. Patients with lesions to the right anterior cingulate (areas 24 and 32) were slower and more variable in their reaction time. These findings could be explained by an inability to sustain stimulus-response contingencies. Lesions to the right ventrolateral prefrontal cortex (Brodmann areas 44, 45, 47) also increased the variability of response, perhaps by disrupting monitoring performance

Incidence of symptomatic toxoplasma eye disease: aetiology and public health implications.

Ocular disease is the commonest disabling consequence of toxoplasma infection. Incidence and lifetime risk of ocular symptoms were determined by ascertaining affected patients in a population-based, active reporting study involving ophthalmologists serving a population of 7.4 million. Eighty-seven symptomatic episodes were attributed to toxoplasma infection. Bilateral visual acuity of 6/12 or less was found in seven episodes (8%) and was likely to have been transient in most cases. Black people born in West Africa had a 100-fold higher incidence of symptoms than white people born in Britain. Only two patients reported symptoms before 10 years of age. The estimated lifetime risk of symptoms in British born individuals (52% of all episodes) was 18/100000 (95% confidence interval: 10.8-25.2). The low risk and mild symptoms in an unscreened British population indicate limited potential benefits of prenatal or postnatal screening. The late age at presentation suggests a mixed aetiology of postnatally acquired and congenital infection for which primary prevention may be appropriate, particularly among West Africans

Quantum phases in entropic dynamics

In the Entropic Dynamics framework the dynamics is driven by maximizing entropy subject to appropriate constraints. In this work we bring Entropic Dynamics one step closer to full equivalence with quantum theory by identifying constraints that lead to wave functions that remain single-valued even for multi-valued phases by recognizing the intimate relation between quantum phases, gauge symmetry, and charge quantization.Comment: Presented at MaxEnt 2017, the 37th International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering (July 9-14, 2017, Jarinu, Brazil

Plasma electrons above Saturn's main rings: CAPS observations

We present observations of thermal ( similar to 0.6 - 100eV) electrons observed near Saturn's main rings during Cassini's Saturn Orbit Insertion (SOI) on 1 July 2004. We find that the intensity of electrons is broadly anticorrelated with the ring optical depth at the magnetic footprint of the field line joining the spacecraft to the rings. We see enhancements corresponding to the Cassini division and Encke gap. We suggest that some of the electrons are generated by photoemission from ring particle surfaces on the illuminated side of the rings, the far side from the spacecraft. Structure in the energy spectrum over the Cassini division and A-ring may be related to photoelectron emission followed by acceleration, or, more likely, due to photoelectron production in the ring atmosphere or ionosphere

Interfacial instability in electrified plane Couette flow

The dynamics of a plane interface separating two sheared, density and viscosity matched fluids in the vertical gap between parallel plate electrodes are studied computationally. A Couette profile is imposed onto the fluids by moving the rigid plates at equal speeds in opposite directions. In addition, a vertical electric field is applied to the shear flow by impressing a constant voltage difference on the electrodes. The stability of the initially flat interface is a very subtle balance between surface tension, inertia, viscosity and electric field effects. Under unstable conditions, the potential difference in the fluid results in an electrostatic pressure that amplifies disturbance waves on the two-fluid interface at characteristic wave lengths. Various mechanisms determining the growth rate of the most unstable mode are addressed in a systematic parameter study. The applied methodology involves a combination of numerical simulation and analytical work. Linear stability theory is employed to identify unstable parametric conditions of the perturbed Couette flow. Particular attention is given to the effect of the applied electric field on the instability of the perturbed two-fluid interface. The normal mode analyses are followed up by numerical simulations. The applied method relies on solving the governing equations for the fluid mechanics and the electrostatics in a one-fluid approximation by using a finite-volume technique combined with explicit tracking of the evolving interface. The numerical results confirm those of linear theory and, furthermore, reveal a rich array of dynamical behaviour. The elementary fluid instabilities are finger-like structures of interpenetrating fluids. For weakly unstable situations a single fingering instability emerges on the interface. Increasing the growth rates causes the finger to form a drop-like tip region connected by a long thinning fluids neck. Even more striking fluid motion occurs at higher values of the electric field parameter for which multiple fluid branches develop on the interface. For a pair of perfect dielectrics the vertical electric field was found to enhance interfacial motion irrespective of the permittivity ratio, while in leaky dielectrics the electric field can either stabilize or destabilize the interface, depending on the conductivity and permittivity ratio between the fluids.</jats:p

IRIS: Supporting & Managing the Research Life-cycle

IRIS is a new Current Research Information System (CRIS) developed by Cineca to upgrade and replace two previous solutions that have been used by Italian universities in the last 10 years. At the end of 2015, sixty-three Italian institutions are using IRIS. One of the main components of IRIS is DSpace-CRIS, an open source solution that can also be used as a standalone system, and as such is now installed in seven institutions outside Italy. The many solutions that IRIS provides include support for national research assessment exercises, institutional repositories (IR) and an expert finder. Both IRIS and DSpace-CRIS are compliant with the Common European Research Information Format (CERIF), allowing easy interchange and benchmarking with other CERIF compliant systems. New IRIS functionality includes Open Researcher and Contributor ID (ORCID) push / pull interoperability. IRIS has five different modules integrated together through standard protocols and interfaces.published_or_final_versio

The Dropping of In-Medium Hadron Mass in Holographic QCD

We study the baryon density dependence of the vector meson spectrum using the D4/D6 system together with the compact D4 baryon vertex. We find that the vector meson mass decreases almost linearly in density at low density for small quark mass, but saturates to a finite non-zero value for large density. We also compute the density dependence of the $\eta\prime$ mass and the $\eta\prime$ velocity. We find that in medium, our model is consistent with the GMOR relation up to a few times the normal nuclear density. We compare our hQCD predictions with predictions made based on hidden local gauge theory that is constructed to model QCD.Comment: 20 pages, 7 figure