Low frequency measurements of synchrotron absorbing HII regions and modeling of observed synchrotron emissivity

Cosmic rays (CRs) and magnetic fields are dynamically important components in the Galaxy, and their energy densities are comparable to that of the turbulent interstellar gas. The interaction of CRs and Galactic magnetic fields produces synchrotron radiation clearly visible in the radio regime. Detailed measurements of synchrotron radiation averaged over the line-of-sight (LOS), so-called synchrotron emissivities, can be used as a tracer of the CR density and Galactic magnetic field (GMF) strength. Our aim is to model the synchrotron emissivity in the Milky Way using a 3 dimensional dataset instead of LOS-integrated intensity maps on the sky. Using absorbed HII regions we can measure the synchrotron emissivity over a part of the LOS through the Galaxy, changing from a 2 dimensional to a 3 dimensional view. Performing these measurements on a large scale is one of the new applications of the window opened by current low frequency arrays. Using various simple axisymmetric emissivity models and a number of GMF-based emissivity models we can simulate the synchrotron emissivities and compare them to the observed values in the catalog. We present a catalog of low-frequency absorption measurements of HII regions, their distances and electron temperatures, compiled from literature. These data show that the axisymmetric emissivity models are not complex enough, but the GMF-based emissivity models deliver a reasonable fit. These models suggest that the fit can be improved by either an enhanced synchrotron emissivity in the outer reaches of the Milky Way, or an emissivity drop near the Galactic center. State-of-the-art GMF models plus a constant CR density model cannot explain low-frequency absorption measurements, but the fits improved with slight (ad-hoc) adaptations. It is clear that more detailed models are needed, but the current results are very promising.Comment: 14 pages, 9 figures, accepted for publication in A&

Stability Analysis for Hybrid Automata Using Conservative Gains

This paper presents a stability analysis approach for a class of hybrid\ud automata. It is assumed that the dynamics in each location of the hybrid automaton is linear and asymptotically stable, and that the guards on the transitions are hyperplanes in the state space. For each pair of ingoing and outgoing transitions in a location a conservative estimate is made of the gain via a Lyapunov function for the dynamics in that location. It is shown how the choice of the Lyapunov function can be optimized to obtain the best possible estimate. The calculated conservative gains are used in defining a so-called gain automaton that forms the basis of an algorithmic criterion for the stability of the hybrid automaton

Simulation of propofol anaesthesia for intracranial decompression using brain hypothermia treatment

<p>Abstract</p> <p>Background</p> <p>Although propofol is commonly used for general anaesthesia of normothermic patients in clinical practice, little information is available in the literature regarding the use of propofol anaesthesia for intracranial decompression using brain hypothermia treatment. A novel propofol anaesthesia scheme is proposed that should promote such clinical application and improve understanding of the principles of using propofol anaesthesia for hypothermic intracranial decompression.</p> <p>Methods</p> <p>Theoretical analysis was carried out using a previously-developed integrative model of the thermoregulatory, hemodynamic and pharmacokinetic subsystems. Propofol kinetics is described using a framework similar to that of this model and combined with the thermoregulation subsystem through the pharmacodynamic relationship between the blood propofol concentration and the thermoregulatory threshold. A propofol anaesthesia scheme for hypothermic intracranial decompression was simulated using the integrative model.</p> <p>Results</p> <p>Compared to the empirical anaesthesia scheme, the proposed anaesthesia scheme can reduce the required propofol dosage by more than 18%.</p> <p>Conclusion</p> <p>The integrative model of the thermoregulatory, hemodynamic and pharmacokinetic subsystems is effective in analyzing the use of propofol anaesthesia for hypothermic intracranial decompression. This propofol infusion scheme appears to be more appropriate for clinical application than the empirical one.</p

Catechol O-methyl transferase and dopamine D2 receptor gene polymorphisms: evidence of positive heterosis and gene–gene interaction on working memory functioning.

The COMT Va

Polarized point sources in the LOFAR Two-meter Sky Survey: A preliminary catalog

The polarization properties of radio sources at very low frequencies (h45m–15h30m right ascension, 45°–57° declination, 570 square degrees). We have produced a catalog of 92 polarized radio sources at 150 MHz at 4.′3 resolution and 1 mJy rms sensitivity, which is the largest catalog of polarized sources at such low frequencies. We estimate a lower limit to the polarized source surface density at 150 MHz, with our resolution and sensitivity, of 1 source per 6.2 square degrees. We find that our Faraday depth measurements are in agreement with previous measurements and have significantly smaller errors. Most of our sources show significant depolarization compared to 1.4 GHz, but there is a small population of sources with low depolarization indicating that their polarized emission is highly localized in Faraday depth. We predict that an extension of this work to the full LOTSS data would detect at least 3400 polarized sources using the same methods, and probably considerably more with improved data processing

Genomweite polygene Werte revolutionieren die Intelligenzforschung

Intelligence — the ability to learn, reason and solve problems — predicts all important life outcomes and is highly heritable. Recent genome-wide association studies have identified inherited genome sequence differences that account for five percent of the variance in intelligence and thus, for ten percent of its heritability. These findings open new avenues for research into the causes and consequences of intelligence using genome-wide polygenic scores that aggregate the effects of thousands of DNA variants

Normal forms and internal regularization of nonlinear differential-algebraic control systems

In this article, we propose two normal forms for nonlinear differential-algebraic control systems (DACSs) under external feedback equivalence, using a notion called maximal controlled invariant submanifold. The two normal forms simplify the system structures and facilitate understanding the various roles of variables for nonlinear DACSs. Moreover, we study when a given nonlinear DACS is internally regularizable, that is, when there exists a state feedback transforming the DACS into a differential-algebraic equation (DAE) with internal regularity, the latter notion is closely related to the existence and uniqueness of solutions of DAEs. We also revise a commonly used method in DAE solution theory, called the geometric reduction method. We apply this method to DACSs and formulate it as an algorithm, which is used to construct maximal controlled invariant submanifolds and to find internal regularization feedbacks. Two examples of mechanical systems are used to illustrate the proposed normal forms and to show how to internally regularize DACSs

Mentaal welbevinden van de jeugd: lessen uit de coronacrisis: Een nieuw overzicht van de onderzoeksliteratuur

Dit rapport biedt een overzicht van onderzoeken naar de belangrijkste gevolgen van de coronacrisis en daaraan gerelateerde maatregelen op het mentaal welbevinden van kinderen, jongeren en jongvolwassenen in Nederland. Doel is ook om de bevindingen uit alle beschikbare onderzoeken door jongeren en onderzoekers gezamenlijk te laten duiden. We kijken in dit rapport naar verschillende aspecten van mentaal welbevinden. Zoals kwaliteit van leven, depressie, angst en psychosomatische klachten, waaronder stress. Ook kijken we naar wat er tijdens de coronacrisis gebeurde in de sociale omgeving van jongeren. Bijvoorbeeld in het gezin, onder leeftijdsgenoten, hun vrijetijdsbesteding, op school en werk. Daarnaast beschouwen we hoe het toekomstperspectief van jongeren zich heeft ontwikkeld tijdens de coronacrisis en hoe jongeren zelf aankijken tegen het coronabelei

The relation between ADHD symptoms and fine motor control: a genetic study

Previous research has shown that fine motor control (MC) performance, measured with a computerized task, was less accurate in children with ADHD and in their unaffected siblings, compared to healthy children. This might indicate a shared genetic etiology between MC and ADHD; it was therefore suggested that MC could serve as endophenotype for ADHD. We examined the association between ADHD symptoms (AS) and MC in a genetically informative design that can distinguish between a genetic and a nongenetic familial etiology for the association. Participants were 12-year-old twins and their siblings (N = 409). AS were rated on a continuous scale with the Strengths and Weaknesses of ADHD and Normal behavior scale (SWAN). MC accuracy and stability was measured with the computerized pursuit task of the Amsterdam Neuropsychological Tasks (ANT). Analyses were performed with Structural Equation Modelling. AS were weakly associated with MC accuracy of the left and right hand (r =-.10/-.10). No association with MC stability was found (r =-.01/-.03). AS were highly heritable (75%), while MC accuracy of the right hand and MC stability showed no genetic influences. For MC accuracy of the left hand, variance was explained by genetic (10%), common environmental (23%), and unique environmental variances. The association between MC accuracy of the left hand and AS was explained by a shared genetic influence but the genetic correlation was low (r =-.14). The phenotypic and genetic associations between AS and computerized MC were weak, suggesting that fine MC is not a proper endophenotype for ADHD. © 2010 Psychology Press