The Complexity of Infinite Computations In Models of Set Theory

We prove the following surprising result: there exist a 1-counter B\"uchi automaton and a 2-tape B\"uchi automaton such that the \omega-language of the first and the infinitary rational relation of the second in one model of ZFC are \pi_2^0-sets, while in a different model of ZFC both are analytic but non Borel sets. This shows that the topological complexity of an \omega-language accepted by a 1-counter B\"uchi automaton or of an infinitary rational relation accepted by a 2-tape B\"uchi automaton is not determined by the axiomatic system ZFC. We show that a similar result holds for the class of languages of infinite pictures which are recognized by B\"uchi tiling systems. We infer from the proof of the above results an improvement of the lower bound of some decision problems recently studied by the author

The relationship between corpus callosum size and forebrain volume

Using high-resolution in vivo magnetic resonance morphometry we measured forebrain volume (FBV), midsagittal size of the corpus callosum (CC) and four CC subareas in 120 young and healthy adults (49 women, 71 men). We found moderate linear and quadratic correlations, indicating that the CC and all CC subareas increase with FBV both in men and women (multiple r2 ranging from 0.10 to 0.28). Allometric equations revealed that these increases were less than proportional to FBV (r2 ranging from 0.02 to 0.30). Absolute CC measurements, as well as CC subareas relative to total CC or FBV (the latter measures termed the CC ratios), were further analyzed with regard to possible effects of handedness, gender, or handedness by gender interaction. Contrary to previous reports, left-handers did not show larger CC measurements compared to right-handers. The only apparent influence of gender was on the CC ratios, which were larger in women. However, smaller brains had larger CC ratios which were mainly independent of gender, a result of the less than proportional increase of callosal size with FBV. We suggest that the previously described gender differences in CC anatomy may be better explained by an underlying effect of brain size, with larger brains having relatively smaller callosa. This lends empirical support to the hypothesis that brain size may be an important factor influencing interhemispheric connectivity and lateralizatio

Molecular evolution of RRM-containing proteins and glycine-rich RNA-binding proteins in plants

*Abstract*

*Background:*
In angiosperms, RNA-binding proteins with an RNA recognition motif (RRM)-type RNA interaction domain play an important role in developmental and environmental responses. Despite their pivotal role, a comprehensive analysis of their number and diversity has only been performed in _Arabidopsis_ so far.

*Results:*
Here we present a detailed phylogenetic analysis of RRM-containing proteins in plants, the red algae _Cyanidioschyzon merolae_ and cyanobacteria. We identified two major events during the diversification of the RRM in plants, one at the emergence of green plants, and the other at the water-to-land transition. We focused on proteins that combine a single RRM with a glycine-rich stretch, known as glycine-rich RNA-binding proteins (GRPs). We found that GRPs are present in cyanobacteria, however plant and cyanobacterial GRPs are not of monophyletic origin. We provide evidence that plant GRPs form a polyphyletic group.
 
*Conclusion:*
Our work provides insights into the origin of GRPs in plants. We determined that the RRM from plants and cyanobacteria do not have a common origin. We could also determine that the acquisition of the glycine-rich stretch has happened at least on three separate occasions during the evolution of GRPs. One event led to the emergence of cyanobacterial GRPs, while later acquisition events led to the emergence of GRPs in the green lineage. No GRPs were found in red or marine green algae. We found a subgroup of GRPs exclusive to land plants, and its appearance may be linked to challenges related to the water-to-land transition.
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Topologies Refining the Cantor Topology on X ω

International audienceThe space of one-sided infinite words plays a crucial rôle in several parts of Theoretical Computer Science. Usually, it is convenient to regard this space as a metric space, the Cantor-space. It turned out that for several purposes topologies other than the one of the Cantor-space are useful, e.g. for studying fragments of first-order logic over infinite words or for a topological characterisation of random infinite words. It is shown that both of these topologies refine the topology of the Cantor-space. Moreover, from common features of these topologies we extract properties which characterise a large class of topologies. It turns out that, for this general class of topologies, the corresponding closure and interior operators respect the shift operations and also, to some respect, the definability of sets of infinite words by finite automata

Do pain-related beliefs influence adherence to multidisciplinary rehabilitation? A systematic review

OBJECTIVES: To understand how pain-related cognitions predict and influence treatment retention and adherence during and after a multidisciplinary rehabilitation program. METHODS: Electronic databases including Medline, CINAHL, PsycINFO, Academic Search Complete, and Scopus were used to search three combinations of keywords: chronic pain, beliefs, and treatment adherence. RESULTS: The search strategy yielded 591 results, with an additional 12 studies identified through reference screening. 81 full-text papers were assessed for eligibility and 10 papers met the inclusion and exclusion criteria for this review. The pain-related beliefs that have been measured in relation to treatment adherence include: pain-specific self-efficacy, perceived disability, catastrophizing, control beliefs, fear-avoidance beliefs, perceived benefits and barriers, as well as other less commonly measured beliefs. The most common pain-related belief investigated in relation to treatment adherence was pain-related self-efficacy. Findings for the pain-related beliefs investigated among the studies were mixed. Collectively, all of the aforementioned pain-related beliefs, excluding control beliefs, were found to influence treatment adherence behaviours. DISCUSSION: The findings suggest that treatment adherence is determined by a combination of pain-related beliefs either supporting or inhibiting chronic pain patients\u27 ability to adhere to treatment recommendations over time. In the studies reviewed, self-efficacy appears to be the most commonly researched predictor of treatment adherence, its effects also influencing other pain-related beliefs. More refined and standardised methodologies, consistent descriptions of pain-related beliefs and methods of measurement will improve our understanding of adherence behaviours

HYBRID MEMBRANE-PSA SYSTEM FOR SEPARATING OXYGEN FROMAR

A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc...) and represents a significant advance compared to current technologies

The acoustic cut-off frequency of the Sun and the solar magnetic activity cycle

The acoustic cut-off frequency -the highest frequency for acoustic solar eigenmodes- is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value, acoustic disturbances are no longer trapped but traveling waves. Interference amongst them give rise to higher-frequency peaks -the pseudomodes- in the solar acoustic spectrum. The pseudomodes are shifted slightly in frequency with respect to p modes making possible the use of pseudomodes to determine the acoustic cut-off frequency. Using data from GOLF and VIRGO instruments on board the SOHO spacecraft, we calculate the acoustic cut-off frequency using the coherence function between both the velocity and intensity sets of data. By using data gathered by these instruments during the entire lifetime of the mission (1996 till the present), a variation in the acoustic cut-off frequency with the solar magnetic activity cycle is found.Comment: Paper accepted in ApJ. 26 Pages, 9 figure

Hourly resolved cloud modification factors in the ultraviolet

Cloud impacts on the transfer of ultraviolet (UV) radiation through the atmosphere can be assessed by using a cloud modification factor (CMF). CMF, which is based on total global solar irradiation (SOL<sub>CMF</sub>), has proved to be a solid basis to derive CMFs for the UV radiation (UV<sub>CMF</sub>). This is an advantage, because total global irradiance, the basis for SOL<sub>CMF</sub>, is frequently measured and forecasted by numerical weather prediction systems and includes all relevant effects for radiation transmission, such as cloud optical depth, different cloud layers, multiple reflection, as well as the distinct difference as to whether the solar disc is obscured by clouds or not. In the UV range clouds decrease the irradiance to a lesser extent than in the visible and infrared spectral range. Thus the relationship between CMFs for solar radiation and for UV-radiation is not straight forward, but will depend on whether, for example, the solar zenith angle (SZA) and wavelength band or action spectrum in the UV have been taken into consideration. Den Outer et al. provide a UV<sub>CMF</sub> algorithm on a daily basis, which accounts for these influences. It requires as input a daily SOL<sub>CMF</sub> and the SZA at noon. The calculation of SOL<sub>CMF</sub> uses the clear-sky algorithm of the European Solar Radiation Atlas to account for varying turbidity impacts. The algorithm's capability to derive hourly UV<sub>CMFs</sub> based on the SZA at the corresponding hour and its worldwide applicability is validated for erythemal UV using observational data retrieved from the databases of the COST-Action 726 on "Long-term changes and climatology of UV radiation over Europe" and the USDA UV-B Monitoring Program. The clear-sky part of the models has proved to be of good quality. Accumulated to daily doses it forms a tight cluster of points to the highest measured daily sums. All sky model performances for hourly resolution are shown to be comparable in accuracy with the well performing daily models of the COST-726 model intercomparison

Capping protein modulates the dynamic behavior of actin filaments in response to phosphatidic Acid in Arabidopsis.

International audienceRemodeling of actin filament arrays in response to biotic and abiotic stimuli is thought to require precise control over the generation and availability of filament ends. Heterodimeric capping protein (CP) is an abundant filament capper, and its activity is inhibited by membrane signaling phospholipids in vitro. How exactly CP modulates the properties of filament ends in cells and whether its activity is coordinated by phospholipids in vivo is not well understood. By observing directly the dynamic behavior of individual filament ends in the cortical array of living Arabidopsis thaliana epidermal cells, we dissected the contribution of CP to actin organization and dynamics in response to the signaling phospholipid, phosphatidic acid (PA). Here, we examined three cp knockdown mutants and found that reduced CP levels resulted in more dynamic activity at filament ends, and this significantly enhanced filament-filament annealing and filament elongation from free ends. The cp mutants also exhibited more dense actin filament arrays. Treatment of wild-type cells with exogenous PA phenocopied the actin-based defects in cp mutants, with an increase in the density of filament arrays and enhanced annealing frequency. These cytoskeletal responses to exogenous PA were completely abrogated in cp mutants. Our data provide compelling genetic evidence that the end-capping activity of CP is inhibited by membrane signaling lipids in eukaryotic cells. Specifically, CP acts as a PA biosensor and key transducer of fluxes in membrane signaling phospholipids into changes in actin cytoskeleton dynamics

Thermal, chemical and morphological properties of carbon fibres derived from chemically pre-treated wool fibres

In this work, the feasibility of using wool fibre as a carbon fibre precursor was explored as well as whether chemical treatments to wool fibre can increase the carbon fibre yield and properties of the produced carbon fibres. Wool fibres were treated with a range of chemicals including lignin, tannic acid, polystyrene sulphonate, and chlorine in conjunction with a polyamide resin. The treated fibres were stabilised in air at 160 C followed by pyrolysis at 800 C under a nitrogen atmosphere. The resulting carbon fibres were characterised in terms of carbon yield, tensile strength, surface roughness, porosity, crystal structure and surface hydrophobicity. The carbon fibre yield was 16.7% for the untreated while the lignin pre-treatment increased the carbon yield up to 25.8%. Generally the surface of the carbon fibre made from both untreated and treated fibre exhibited high hydrophilicity except the lignin and chlorine/polyamide resintreated fibre which showed hydrophobicity. Although the tensile strength achieved for the various produced carbon fibre was poor compared to a commercially available pitch-based carbon fibre, the developed carbon fibre still can be utilised in thermoplastic composite manufacturing