Motor kinematic differences in children with autism sepectrum disorder : ecological gameplay with a sensorised toy

Background Evidence suggests gross motor differences are present in children with Autism Spectrum Disorder (ASD) from birth. Trevarthen and Delafield-Butt (2013) proposed that one of the early markers of ASD are abnormalities in the development of intentional movements, which are present before the manifestations of symptoms typically associated with autism, like deficiencies in social interaction and communication. A growing body of literature demonstrates kinematic and action patterns differences in children and adults with ASD. However, these experiments typically require expensive laboratory-based optical motion tracking systems. Here, we developed bespoke, sensorised wooden cubes for motor assessment of children’s play and report on the kinematic and action pattern differences of the children with autism compared to children developing typically. Objectives A description of ASD-specific action patterns and kinematics using sensorised toys. Methods Participants. Children 3 to 5 years diagnosed with ASD (n = 15) recruited from the Scottish Centre for Autism, Glasgow, UK. Children 3 to 5 years old developing typically recruited from nurseries in Glasgow, UK. Adults 20 to 25 years old without ASD recruited from Glasgow, UK. The study was approved by the University of Strathclyde Ethics Committee and consent obtained from the parents of children or the adults. In the case of the children with ASD, pre-screening with Vineland-II, AQ-Child and Leiter-R Brief IQ was performed. Procedure. The children were seated at a table and instructed to play two simple games that involved moving the cube from one position to another: a Serially Organized Action (SOA) game and a Single Repetitive Action (SRA) game. The first required complex motor sequencing and engagement with the experimenter, while the second consisted of a simple repetitive movement. Each game produced a single measured movement to a goal with 25 iterations or repetitions to yield 50 movements in total. An electronic board inside the cubes was equipped with tri-axial magnetometer, gyroscope and accelerometer wirelessly transferred the cube’s motion data to a laptop. The signal (raw motion data) was extracted through a Matlab-based platform and analysed. Data Analysis. Kinematic features of movement duration; maximum value of acceleration, velocity, and jerk during each movement; time to maximum value; % duration to maximum value; and the acceleration, velocity, and jerk action patterns profiles were calculated. Results The jerk profile of children with ASD was significantly different, showing increased maximum jerk, reduced time to maximum value and & duration to maximum value, and lower variability than typically developing children. Further, movement duration was shorter compared to age-matched typically developing children, and maximum velocity was significantly higher in children with ASD compared to children developing typically. Conclusion The increased jerk values and onset times in the ASD group are a particularly interesting finding that support new data appearing by other groups. It appeared, especially in the SRA game, that when moving the cube from one position to the next, the children with autism impacted on the surface of the table with greater velocity and typically included the resulting force immediately into to the next movement, giving it a greater jerk value in a shorter span of time that typically children. Typically developing children, on the other hand, paused for a moment (>100 ms) before commencing the next movement. Further, children with autism did not enjoy the SRA game, but they did enjoy the simpler, more repetitive SOA one. The repetitive simplicity of the SOA game and its resulting jerk profile appears to report on a particular behavioural motor feature distinct to ASD, namely stopping an action and starting a new one, while also describing an underlying motor difference that may contribute to it

An enhanced CRISPR repressor for targeted mammalian gene regulation.

The RNA-guided endonuclease Cas9 can be converted into a programmable transcriptional repressor, but inefficiencies in target-gene silencing have limited its utility. Here we describe an improved Cas9 repressor based on the C-terminal fusion of a rationally designed bipartite repressor domain, KRAB-MeCP2, to nuclease-dead Cas9. We demonstrate the system's superiority in silencing coding and noncoding genes, simultaneously repressing a series of target genes, improving the results of single and dual guide RNA library screens, and enabling new architectures of synthetic genetic circuits

Polarization of Dust Emission in Clumpy Molecular Clouds and Cores

Grain alignment theory has reached the stage where quantitative predictions of the degree of alignment and its variations with optical depth are possible. With the goal of studying the effect of clumpiness on the sub-millimeter and far infrared polarization we computed the polarization due to alignment via radiative torques within clumpy models of cores and molecular clouds. Our models were based upon a highly inhomogeneous simulation of compressible magnetohydrodynamic turbulence. The P-I relations for our models reproduce those seen in observations. We show that the degree of polarization observed is extremely sensitive to the upper grain size cut-off, and is less sensitive to changes in the radiative anisotropy. Furthermore, despite a variety of dust temperatures along a single line of sight through our core and amongst dust grains of different sizes, the assumption of isothermality amongst the aligned grains does not introduce a significant error. Our calculations indicate that sub-mm polarization vectors can be reasonably good tracers for the underlying magnetic field structure, even for relatively dense clouds (A_V~10 to the cloud center). The current predictive power of the grain alignment theory should motivate future polarization observations using the next generation of multi-wavelength sub-mm polarimeters such as those proposed for SOFIA.Comment: 39 pages. 15 figures. Submitted to Ap

A scenario of planet erosion by coronal radiation

Context: According to theory, high-energy emission from the coronae of cool stars can severely erode the atmospheres of orbiting planets. No observational tests of the long term effects of erosion have yet been made. Aims: To analyze the current distribution of planetary mass with X-ray irradiation of the atmospheres in order to make an observational assessment of the effects of erosion by coronal radiation. Methods: We study a large sample of planet-hosting stars with XMM-Newton, Chandra and ROSAT; make a careful identification of X-ray counterparts; and fit their spectra to make accurately measurements of the stellar X-ray flux. Results: The distribution of the planetary masses with X-ray flux suggests that erosion has taken place: most surviving massive planets, (M_p sin i >1.5 M_J), have been exposed to lower accumulated irradiation. Heavy erosion during the initial stages of stellar evolution is followed by a phase of much weaker erosion. A line dividing these two phases could be present, showing a strong dependence on planet mass. Although a larger sample will be required to establish a well-defined erosion line, the distribution found is very suggestive. Conclusions: The distribution of planetary mass with X-ray flux is consistent with a scenario in which planet atmospheres have suffered the effects of erosion by coronal X-ray and EUV emission. The erosion line is an observational constraint to models of atmospheric erosion.Comment: A&A 511, L8 (2010). 4 pages, 3 figures, 1 online table (included). Language edited; corrected a wrong unit conversion (g/s -> M_J/Gyr); corrected values in column 12 of Table 1 (slightly underestimated in first version), and Figure 2 updated accordingl

Foliar lead uptake by lettuce exposed to atmospheric fallouts

Metal uptake by plants occurs by soil−root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 ± 50 mg Pb kg−1 (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination

Cosmic-ray propagation in molecular clouds

Cosmic-rays constitute the main ionising and heating agent in dense, starless, molecular cloud cores. We reexamine the physical quantities necessary to determine the cosmic-ray ionisation rate (especially the cosmic ray spectrum at E < 1 GeV and the ionisation cross sections), and calculate the ionisation rate as a function of the column density of molecular hydrogen. Available data support the existence of a low-energy component (below about 100 MeV) of cosmic-ray electrons or protons responsible for the ionisation of diffuse and dense clouds. We also compute the attenuation of the cosmic-ray flux rate in a cloud core taking into account magnetic focusing and magnetic mirroring, following the propagation of cosmic rays along flux tubes enclosing different amount of mass and mass-to-flux ratios. We find that mirroring always dominates over focusing, implying a reduction of the cosmic-ray ionisation rate by a factor of 3-4 depending on the position inside the core and the magnetisation of the core.Comment: To appear in "Cosmic Rays in Star-Forming Environments", Proceedings of the 2nd Session of the Sant Cugat Forum on Astrophysics. D. F. Torres and O. Reimer (Editors), 2013, Springer, 25 pages, 11 figure

Performance of the TOTEM Detectors at the LHC

The TOTEM Experiment is designed to measure the total proton-proton cross-section with the luminosity-independent method and to study elastic and diffractive pp scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the interaction point IP5, two tracking telescopes, T1 and T2, are installed on each side of the IP in the pseudorapidity region 3.1 < = |eta | < = 6.5, and special movable beam-pipe insertions - called Roman Pots (RP) - are placed at distances of +- 147 m and +- 220 m from IP5. This article describes in detail the working of the TOTEM detector to produce physics results in the first three years of operation and data taking at the LHC.Comment: 40 pages, 31 figures, submitted to Int. J. Mod. Phys.

Construction and Performance of Large-Area Triple-GEM Prototypes for Future Upgrades of the CMS Forward Muon System

At present, part of the forward RPC muon system of the CMS detector at the CERN LHC remains uninstrumented in the high-\eta region. An international collaboration is investigating the possibility of covering the 1.6 < |\eta| < 2.4 region of the muon endcaps with large-area triple-GEM detectors. Given their good spatial resolution, high rate capability, and radiation hardness, these micro-pattern gas detectors are an appealing option for simultaneously enhancing muon tracking and triggering capabilities in a future upgrade of the CMS detector. A general overview of this feasibility study will be presented. The design and construction of small (10\times10 cm2) and full-size trapezoidal (1\times0.5 m2) triple-GEM prototypes will be described. During detector assembly, different techniques for stretching the GEM foils were tested. Results from measurements with x-rays and from test beam campaigns at the CERN SPS will be shown for the small and large prototypes. Preliminary simulation studies on the expected muon reconstruction and trigger performances of this proposed upgraded muon system will be reported.Comment: 7 pages, 25 figures, submitted for publication in conference record of the 2011 IEEE Nuclear Science Symposium, Valencia, Spai