Dyslexia and Cerebral Dysfunction

Children with slow visual-motor responses to visual-temporal response tests also have brain dysfunctions in the mobile and motor areas (6, 4). If the left parietal cortex does not participate in these dysfunctions, then this child will also have difficulties in reading. Furthermore, we could say that the brain dysfunctions that are detected by visual-motor tests and that the performance in them is low, are accompanied by difficulties in reading. Aim: In this study we want to show the function of the child's brain in dyslexia. Method: We followed the most up-to-date literature on the subject: neuropsychology and dyslexia. Conclusions: brain organization and its relationship to dyslexia is a major problem for Neuropsychology and Neurolinguistics.

Strategies for improved temporal response of glass-based optical switches

We present an optimization of the dynamics of integrated optical switches based on thermal phase shifters. These devices have been fabricated in the volume of glass substrates by femtosecond laser micromachining and are constituted by an integrated Mach–Zehnder interferometer and a superficial heater. Simulations, surface micromachining and innovative layouts allowed us to improve the temporal response of the optical switches down to a few milliseconds. In addition, taking advantage of an electrical pulse shaping approach where an optimized voltage signal is applied to the heater, we proved a switching time as low as 78 µs, about two orders of magnitude shorter with respect to the current state of the art of thermally-actuated optical switches in glass.

Dyslexia and Cerebral Dysfunction

Children with slow visual-motor responses to visual-temporal response tests also have brain dysfunctions in the mobile and motor areas [6,4]. If the left parietal cortex does not participate in these dysfunctions, then this child will also have difficulties in reading. Furthermore, we could say that the brain dysfunctions that are detected by visual-motor tests and that the performance in them is low, are accompanied by difficulties in reading. Aim: In this study we want to show the function of the child’s brain in dyslexia. Method: We followed the most up-to-date literature on the subject: neuropsychology and dyslexia. Conclusions: brain organization and its relationship to dyslexia is a major problem for Neuropsychology and Neurolinguistics.

Spatial–Temporal Response of Reactive Oxygen Species and Salicylic Acid Suggest Their Interaction in Pumpkin Rootstock-Induced Chilling Tolerance in Watermelon Plants

Grafting with pumpkin rootstock could improve chilling tolerance in watermelon, and salicylic acid (SA) as a signal molecule is involved in regulating plant tolerance to chilling and other abiotic stresses. To clarify the mechanism in pumpkin rootstock-induced systemic acquired acclimation in grafted watermelon under chilling stress, we used self-grafted (Cl/Cl) and pumpkin rootstock-grafted (Cl/Cm) watermelon seedlings to study the changes in lipid peroxidation, photosystem II (PSII) activity and antioxidant metabolism, the spatio–temporal response of SA biosynthesis and H2O2 accumulation to chilling, and the role of H2O2 signal in SA-induced chilling tolerance in grafted watermelon. The results showed that pumpkin rootstock grafting promoted SA biosynthesis in the watermelon scions. Chilling induced hydrolysis of conjugated SA into free SA in the roots and accumulation of free SA in the leaves in Cl/Cm plants. Further, pumpkin rootstock grafting induced early response of antioxidant enzyme system in the roots and increased activities of ascorbate peroxidase and glutathione reductase in the leaves, thus maintaining cellular redox homeostasis. Exogenous SA improved while the inhibition of SA biosynthesis reduced chilling tolerance in Cl/Cl seedlings. The application of diphenyleneiodonium (DPI, inhibitor of NADPH oxidase) and dimethylthiourea (DMTU, H2O2 scavenger) decreased, while exogenous H2O2 improved the PSII activity in Cl/Cl plants under chilling stress. Additionally, the decrease of the net photosynthetic rate in DMTU- and DPI-pretreated Cl/Cl plants under chilling conditions could be alleviated by subsequent application of H2O2 but not SA. In conclusion, pumpkin rootstock grafting induces SA biosynthesis and redistribution in the leaves and roots and participates in the regulation of antioxidant metabolism probably through interaction with the H2O2 signal, thus improving chilling tolerance in watermelon.

Ratcheting and recovery of adhesively bonded joints under tensile cyclic loading

Polymers in general, and adhesives in particular, can exhibit nonlinear viscoelastic–viscoplastic response. Prior work has shown that this complex behavior can be described using analytical models, which provided good agreement with measured creep and recovery response. Under cyclic loading, however, some adhesives exhibit a temporal response different from what would be expected from their creep behavior. Ratcheting describes the accumulation of deformation from cyclic loading. The failure surfaces of adhesives subjected to creep and cyclic loads provide evidence of failure modes that depend on the loading history, suggesting a cause for the change in temporal response. The following considers two approaches to describe the ratcheting behavior of adhesives. Given the reduced time dependence, the first approach involved a nonlinear viscoelastic–plastic model. The second approach used a nonlinear viscoelastic–viscoplastic model, calibrated from the cyclic response, rather than the creep response. While both models showed good agreement with experiment for long exposure to cyclic loading, only the viscoelastic–viscoplastic model agreed with experiment for both short and long loading histories.

The impulse response of optic flow-sensitive descending neurons to roll m-sequences

ABSTRACT When animals move through the world, their own movements generate widefield optic flow across their eyes. In insects, such widefield motion is encoded by optic lobe neurons. These lobula plate tangential cells (LPTCs) synapse with optic flow-sensitive descending neurons, which in turn project to areas that control neck, wing and leg movements. As the descending neurons play a role in sensorimotor transformation, it is important to understand their spatio-temporal response properties. Recent work shows that a relatively fast and efficient way to quantify such response properties is to use m-sequences or other white noise techniques. Therefore, here we used m-sequences to quantify the impulse responses of optic flow-sensitive descending neurons in male Eristalis tenax hoverflies. We focused on roll impulse responses as hoverflies perform exquisite head roll stabilizing reflexes, and the descending neurons respond particularly well to roll. We found that the roll impulse responses were fast, peaking after 16.5–18.0 ms. This is similar to the impulse response time to peak (18.3 ms) to widefield horizontal motion recorded in hoverfly LPTCs. We found that the roll impulse response amplitude scaled with the size of the stimulus impulse, and that its shape could be affected by the addition of constant velocity roll or lift. For example, the roll impulse response became faster and stronger with the addition of excitatory stimuli, and vice versa. We also found that the roll impulse response had a long return to baseline, which was significantly and substantially reduced by the addition of either roll or lift.

Neural entrainment is strongest to the spectral flux of slow music and depends on familiarity and beat salience

Neural activity in the auditory system synchronizes to sound rhythms, and brain environment synchronization is thought to be fundamental to successful auditory perception. Sound rhythms are often operationalized in terms of the sound's amplitude envelope. We hypothesized that, especially for music, the envelope might not best capture the complex spectrotemporal fluctuations that give rise to beat perception and synchronize neural activity. This study investigated 1) neural entrainment to different musical features, 2) tempo dependence of neural entrainment, and 3) dependence of entrainment on familiarity, enjoyment, and ease of beat perception. In this electroencephalography study, 37 human participants listened to tempo modulated music (1 to 4 Hz). Independent of whether the analysis approach was based on temporal response functions (TRFs) or reliable components analysis (RCA), the spectral flux of music, as opposed to the amplitude envelope, evoked strongest neural entrainment. Moreover, music with slower beat rates, high familiarity, and easy to perceive beats elicited the strongest neural response. Based on the TRFs, we could decode music stimulation tempo, but also perceived beat rate, even when the two differed. Our results demonstrate the importance of accurately characterizing musical acoustics in the context of studying neural entrainment, and demonstrate the sensitivity of entrainment to musical tempo, familiarity, and beat salience.