CONSTRAINING THE ATMOSPHERIC COMPOSITION OF THE DAY-NIGHT TERMINATORS OF HD 189733b: ATMOSPHERIC RETRIEVAL WITH AEROSOLS

A number of observations have shown that Rayleigh scattering by aerosols dominates the transmission spectrum of HD 189733b at wavelengths shortward of 1 μm. In this study, we retrieve a range of aerosol distributions consistent with transmission spectroscopy between 0.3-24 μm that were recently re-analyzed by Pont et al. To constrain the particle size and the optical depth of the aerosol layer, we investigate the degeneracies between aerosol composition, temperature, planetary radius, and molecular abundances that prevent unique solutions for transit spectroscopy. Assuming that the aerosol is composed of MgSiO3, we suggest that a vertically uniform aerosol layer over all pressures with a monodisperse particle size smaller than about 0.1 μm and an optical depth in the range 0.002-0.02 at 1 μm provides statistically meaningful solutions for the day/night terminator regions of HD 189733b. Generally, we find that a uniform aerosol layer provide adequate fits to the data if the optical depth is less than 0.1 and the particle size is smaller than 0.1 μm, irrespective of the atmospheric temperature, planetary radius, aerosol composition, and gaseous molecules. Strong constraints on the aerosol properties are provided by spectra at wavelengths shortward of 1 μm as well as longward of 8 μm, if the aerosol material has absorption features in this region. We show that these are the optimal wavelengths for quantifying the effects of aerosols, which may guide the design of future space observations. The present investigation indicates that the current data offer sufficient information to constrain some of the aerosol properties of HD189733b, but the chemistry in the terminator regions remains uncertain.

The Deep Blue Color of HD 189733b: Albedo Measurements with Hubble Space Telescope/Space Telescope Imaging Spectrograph at Visible Wavelengths

We present a secondary eclipse observation for the hot Jupiter HD 189733b across the wavelength range 290-570 nm made using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. We measure geometric albedos of Ag = 0.40 ± 0.12 across 290-450 nm and Ag < 0.12 across 450-570 nm at 1σ confidence. The albedo decrease toward longer wavelengths is also apparent when using six wavelength bins over the same wavelength range. This can be interpreted as evidence for optically thick reflective clouds on the dayside hemisphere with sodium absorption suppressing the scattered light signal beyond ~450 nm. Our best-fit albedo values imply that HD 189733b would appear a deep blue color at visible wavelengths.

Cathodal HD-tDCS on the right V5 improves motion perception in humans

Brain lesions in the visual associative cortex are known to impair visual perception, i.e., the capacity to correctly perceive different aspects of the visual world, such as motion, color, or shapes. Visual perception can be influenced by non-invasive brain stimulation such as transcranial direct current stimulation (tDCS). In a recently developed technique called high definition (HD) tDCS, small HD-electrodes are used instead of the sponge electrodes in the conventional approach. This is believed to achieve high focality and precision over the target area. In this paper we tested the effects of cathodal and anodal HD-tDCS over the right V5 on motion and shape perception in a single blind, within-subject, sham controlled, cross-over trial. The purpose of the study was to prove the high focality of the stimulation only over the target area. Twenty one healthy volunteers received 20 min of 2 mA cathodal, anodal and sham stimulation over the right V5 and their performance on a visual test was recorded. The results showed significant improvement in motion perception in the left hemifield after cathodal HD-tDCS, but not in shape perception. Sham and anodal HD-tDCS did not affect performance. The specific effect of influencing performance of visual tasks by modulating the excitability of the neurons in the visual cortex might be explained by the complexity of perceptual information needed for the tasks. This provokes a "noisy" activation state of the encoding neuronal patterns. We speculate that in this case cathodal HD-tDCS may focus the correct perception by decreasing global excitation and thus diminishing the "noise" below threshold.

Desarrollo de un sistema para la conversión de imágenes de vídeo PAL a imágenes HD

En las ultimas décadas hemos sufrido un gran cambio en el modo, como en la calidad de Vida en el cual se debe a gran medida al avance tan grande que ha habido en el mundo tecnológico. Alguno de estos avances y en el cual tratara el proyecto son la codificaciones y formato de video. En las décadas que llevamos de televisión en color hay dos formatos de video en los cuales han destacado sobre el resto uno que es el sistema de codificación analógico PAL ,que es el sistema de televisión Analógica que se utilizaba en toda Europa (Exceptuando Francia) y en la mayoría de la población mundial. Por otro lado tenemos el otro sistema de video que es el HD aunque el proyecto lleva 40 años existiendo he tomado una mayor importancia ahora con el cambio que se ha habido de pasar de una televisión analógica a una televisión digital. En este proyecto se creara una herramienta capaz de transformar un video en Formato PAL que es un formato que tiene 720 pixeles de longitud y 576 pixeles de altura al formato de video HD que en su caso tiene las dimensiones 1920x 1080 pixeles de longitud y altura respectivamente.

Arabidopsis DELLA and two HD-ZIP transcription factors regulate GA signalling in the epidermis through the L1 cis-element

Gibberellins (GAs) are plant hormones that affect plant growth and regulate gene expression differentially across tissues. To study the molecular mechanisms underlying GA signaling in Arabidopsis thaliana, we focused on a GDSL lipase gene (LIP1) induced by GA and repressed by DELLA proteins. LIP1 contains an L1 box promoter sequence, conserved in the promoters of epidermis-specific genes, that is bound by ATML1, an HD-ZIP transcription factor required for epidermis specification. In this study, we demonstrate that LIP1 is specifically expressed in the epidermis and that its L1 box sequence mediates GA-induced transcription. We show that this sequence is overrepresented in the upstream regulatory regions of GA-induced and DELLA-repressed transcriptomes and that blocking GA signaling in the epidermis represses the expression of L1 box–containing genes and negatively affects seed germination. We show that DELLA proteins interact directly with ATML1 and its paralogue PDF2 and that silencing of both HD-ZIP transcription factors inhibits epidermal gene expression and delays germination. Our results indicate that, upon seed imbibition, increased GA levels reduce DELLA protein abundance and release ATML1/PDF2 to activate L1 box gene expression, thus enhancing germination potential.

Re-Examining the Stop-Signal Task to Test Competing Theories of AD/HD

The current study tested two competing models of Attention-Deficit/Hyperactivity Disorder (AD/HD), the inhibition and state regulation theories, by conducting fine-grained analyses of the Stop-Signal Task and another putative measure of behavioral inhibition, the Gordon Continuous Performance Test (G-CPT), in a large sample of children and adolescents. The inhibition theory posits that performance on these tasks reflects increased difficulties for AD/HD participants to inhibit prepotent responses. The model predicts that putative stop-signal reaction time (SSRT) group differences on the Stop-Signal Task will be primarily related to AD/HD participants requiring more warning than control participants to inhibit to the stop-signal and emphasizes the relative importance of commission errors, particularly "impulsive" type commissions, over other error types on the G-CPT. The state regulation theory, on the other hand, proposes response variability due to difficulties maintaining an optimal state of arousal as the primary deficit in AD/HD. This model predicts that SSRT differences will be more attributable to slower and/or more variable reaction time (RT) in the AD/HD group, as opposed to reflecting inhibitory deficits. State regulation assumptions also emphasize the relative importance of omission errors and "slow processing" type commissions over other error types on the G-CPT. Overall, results of Stop-Signal Task analyses were more supportive of state regulation predictions and showed that greater response variability (i.e., SDRT) in the AD/HD group was not reducible to slow mean reaction time (MRT) and that response variability made a larger contribution to increased SSRT in the AD/HD group than inhibitory processes. Examined further, ex-Gaussian analyses of Stop-Signal Task go-trial RT distributions revealed that increased variability in the AD/HD group was not due solely to a few excessively long RTs in the tail of the AD/HD distribution (i.e., tau), but rather indicated the importance of response variability throughout AD/HD group performance on the Stop-Signal Task, as well as the notable sensitivity of ex-Gaussian analyses to variability in data screening procedures. Results of G-CPT analyses indicated some support for the inhibition model, although error type analyses failed to further differentiate the theories. Finally, inclusion of primary variables of interest in exploratory factor analysis with other neurocognitive predictors of AD/HD indicated response variability as a separable construct and further supported its role in Stop-Signal Task performance. Response variability did not, however, make a unique contribution to the prediction of AD/HD symptoms beyond measures of motor processing speed in multiple deficit regression analyses. Results have implications for the interpretation of the processes reflected in widely-used variables in the AD/HD literature, as well as for the theoretical understanding of AD/HD.

Hot thermal X-ray emission from the Be star HD 119682

We present an analysis of a series of four consecutive Chandra high-resolution transmission gratings observations, amounting to a total of 150 ks, of the Be X-ray source HD 119682 (=1WGA J1346.5–6255), a member of the new class of γ Cas analogs. The Chandra light curve shows significant brightness variations on timescales of hours. However, the spectral distribution appears rather stable within each observation and during the whole campaign. A detailed analysis is not able to detect any coherent pulsation up to a frequency of 0.05 Hz. The Chandra High Energy Transmission Gratings spectrum seems to be devoid of any strong emission line, including Fe Kα fluorescence. The continuum is well described with the addition of two collisionally ionized plasmas of temperatures kT ≈ 15 keV and 0.2 keV, respectively, by the apec model. Models using photoionized plasma components (mekal) or non-thermal components (powerlaw) give poorer fits, providing support for the pure thermal scenario. These two components are absorbed by a single column with N H = (0.20+0.15 –0.03) × 1022 cm–2 compatible with the interstellar value. We conclude that HD 119682 can be regarded as a pole-on γ Cas analog.

Direct support and general support maintenance manual : antenna and microwave equipment including feed assembly AS-2941 ( )/FSC, (NSN 5895-00-639-4793), dehumidifier, desiccant, electric HD-988/G, (NSN 4440-01-018-0080) for satellite communication terminals AN/FSC-78(V) and AN/FSC-79.

Includes index.

Clinical evaluation of the Softec HD aberration-free aspheric intraocular lens

Purpose: To compare distance and near visual performance with a zero-aberration aspheric intraocular lens (IOL) (Softec HD, Lenstec, Inc. FL, USA) with that of an otherwise identical, but spherical IOL (Softec 1). Setting: Department of Ophthalmology, Solihull Hospital, West Midlands, United Kingdom. Methods: This prospective study comprised 37 patients with a Softec 1 spherical IOL implanted in one eye, who underwent phacoemulsification and received the Softec HD aspheric IOL in the fellow eye. One month post-operatively, unaided distance and near vision, residual refraction, best spectacle corrected distance and near visual acuity, reading speed, pseudoaccommodation and photopic contrast sensitivity were recorded. Wavefront analysis enabled comparison of higher order aberrations between the IOLs. Results: Prior to surgery, the Softec 1 and Softec HD eyes were not significantly different. Post-operatively, unaided vision, best spectacle corrected visual acuity and residual refraction were not significantly different between the eyes, nor were there significant differences observed between the measured wavefront aberrations. Once implanted, the range of focus was significantly better in the Softec HD IOL eye than the Softec 1 IOL eye and, although reading speed was equivalent to the Softec 1 eye, the print size at which this could be achieved was significantly smaller. Conclusions: Depth of field was significantly improved with the aspheric IOL compared with the spherical IOL, without any compromise in distance visual performance between the two IOLs.

Differential contributions of the mIPS and PMd in the movement planning of reaches investigated through HD-tDCS

To reach for a target, we must formulate a movement plan - a difference vector of the target position with respect to the starting hand position. While it is known that the medial part of the intraparietal sulcus (mIPS) and the dorsal premotor (PMd) activity reflects aspects of a kinematic plan for a reaching movement, it is unclear whether or how the two regions may differ. We investigated the functional roles of the mIPS and PMd in the planning of reaching movements using high definition transcranial direct current stimulation (HD-tDCS) and examined changes in horizontal endpoint error when participants were subjected to anodal and cathodal stimulation. The left mIPS and PMd were functionally localized with fMRI in each participant using an interleaved center-out pointing and saccade task and mapped onto the scalp using Brainsight. We adopted a randomized, single-blind design and applied anodal and cathodal stimulation (2mA for 20 min; 3cm radius 4x1 electrode placement) during 4 separate visits scheduled at least a week apart. Each participant performed 250 baseline, stimulation, and post-stimulation memory-guided reaches starting from one of two initial hand positions (IHPs) to one of 4 briefly flashed targets (20 cm distant, 5 cm apart horizontally) while fixating on a straight-ahead cross located at the target line. Separate 2-way repeated measures ANOVAs of horizontal endpoint error difference after cathodal tDCS at each stimulation site revealed a significant IHP by target position interaction effect at the left mIPS, and significant IHP and target main effects at the left PMd. Behaviorally, these effects corresponded to IHP-dependent contractions after cathodal mIPS tDCS and IHP-independent contractions after cathodal PMd tDCS. These results suggest that the movement vector is not yet formed at the input level of mIPS, but is encoded at the input of PMd. These results also indicate that tDCS is a viable, useful method in investigating movement planning properties through temporary perturbations of the system.

The HARPS-N Rocky Planet Search. I. HD 219134 b: A transiting rocky planet in a multi-planet system at 6.5 pc from the Sun

We know now from radial velocity surveys and transit space missions thatplanets only a few times more massive than our Earth are frequent aroundsolar-type stars. Fundamental questions about their formation history,physical properties, internal structure, and atmosphere composition are,however, still to be solved. We present here the detection of a systemof four low-mass planets around the bright (V = 5.5) and close-by (6.5pc) star HD 219134. This is the first result of the Rocky Planet Searchprogramme with HARPS-N on the Telescopio Nazionale Galileo in La Palma.The inner planet orbits the star in 3.0935 ± 0.0003 days, on aquasi-circular orbit with a semi-major axis of 0.0382 ± 0.0003AU. Spitzer observations allowed us to detect the transit of the planetin front of the star making HD 219134 b the nearest known transitingplanet to date. From the amplitude of the radial velocity variation(2.25 ± 0.22 ms-1) and observed depth of the transit(359 ± 38 ppm), the planet mass and radius are estimated to be4.36 ± 0.44 M⊕ and 1.606 ± 0.086R⊕, leading to a mean density of 5.76 ± 1.09 gcm-3, suggesting a rocky composition. One additional planetwith minimum-mass of 2.78 ± 0.65 M⊕ moves on aclose-in, quasi-circular orbit with a period of 6.767 ± 0.004days. The third planet in the system has a period of 46.66 ± 0.08days and a minimum-mass of 8.94 ± 1.13 M⊕, at0.233 ± 0.002 AU from the star. Its eccentricity is 0.46 ±0.11. The period of this planet is close to the rotational period of thestar estimated from variations of activity indicators (42.3 ± 0.1days). The planetary origin of the signal is, however, thepreferredsolution as no indication of variation at the corresponding frequency isobserved for activity-sensitive parameters. Finally, a fourth additionallonger-period planet of mass of 71 M⊕ orbits the starin 1842 days, on an eccentric orbit (e = 0.34 ± 0.17) at adistance of 2.56 AU.The photometric time series and radial velocities used in this work areavailable in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr(ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/584/A72