A magnetic resonance imaging study of planum temporale asymmetry in men with developmental dyslexia

The influence of ionic strength and composition on the binding and inhibition of human leukocyte elastase by glycosaminoglycans with variable degree and position of sulfation was investigated. The kinetic mechanism of inhibition had a hyperbolic, mixed-type character with a competitive component that was promoted by low ionic strength, reduced by phosphate ions, and which also depended on the substrate and glycosaminoglycan structure. Enzyme binding was a cooperative phenomenon that varied with ionic strength and composition. The inhibition patterns correlated with the cationic character of elastase and with the distribution of arginines on its molecular surface, most notably with residues located in the vicinity of the substrate binding region. The order of affinity for elastase binding was chondroitin 4-sulfate < chondroitin 6-sulfate < dermatan sulfate, iduronate-containing derivatives being superior with respect to the glucuronate-containing counterparts. Additional sulfation at both the 4- and 6- positions or at the N- and 4-positions of the N-acetylgalactosamine moiety decidedly improved the inhibitory efficiency. The results highlight a fundamental physiological role of enzyme-glycosaminoglycan interactions. In the azurophil granule of the human polymorphonuclear neutrophil, elastase and other enzymes are bound to a matrix of chondroitin 4-sulfate because this is the only glycosaminoglycan that simultaneously offers good binding for enzyme compartmentalization together with prompt release from the bound state at the onset of phagocytosis.     

Experimental Study of Cassava Sun Drying

ABSTRACT

Sun drying experiments were performed to compare drying of cassava chips in sheet-metal trays with drying on mesh wire trays: In the sheet-metal trays, there was air flow across the top of the bed chips, while the mesh wire trays permitted air to flow through the bed. Drying rate was faster and more uniform in the trays with through-flow air circulation. Higher temperatures were reached by chips in the sheet-metal trays than those in the mesh wire trays because of contact heating, but the drying rate was lower because of the reduced air flow.     

EXPERIMENTAL STUDY OF CASSAVA SUN DRYING

ABSTRACT

Experiments were carried out in Davis, California, USA to compare sun drying of a bed of cassava chips placed in wire mesh trays with those placed in trays made of sheet metal. The wire mesh permitted wind to blow easily through the bed of chips, while the sheet metal constrained the wind to flow across the top of the bed, Drying was faster in the wire mesh trays; the chips reached a moisture content for safe storage after 27 hours of drying, while those in the sheet metal trays took 35 hours. The uniformity of drying was also markedly better in the wire mesh trays. Higher temperatures were attained in the chips contained in the sheet metal trays due to contact heat transfer between the trays and the chips. However the restricted air flow around the chips in the sheet metal trays led them to dry slower than those in the wire mesh trays.     

Point-source suppression for atmospheric wave extraction from airglow imaging measurements

Spectroscopic images of atmospheric chemiluminescent airglow contain fundamental diagnostic information about the structure and dynamics of the upper atmosphere. However, westward movement of stars causes non-negligible contamination in the two-dimensional horizontal wavenumber spectra extracted from all-sky airglow images. The conventional star-removing scheme is not effective in attenuating the star artifacts in the spectra of emission intensities of gravity wave perturbation, hindering the subsequent calculation of the angular spectra and the momentum fluxes of the profiles. To address this problem, a gradient-based edge detection algorithm for locating and attenuating the undesired star signal is developed. Comparatively, this algorithm is more effective than the conventional star-removing methods. The algorithm is validated in the context of experimentally obtained spectra.     

Flexible Transparent Hierarchical Nanomesh for Rose Petal‐Like Droplet Manipulation and Lossless Transfer

Precise manipulation of water is a key step in numerous natural and synthetic processes. Here, a new flexible and transparent hierarchical structure is determined that allows ultra‐dexterous manipulation and lossless transfer of water droplets. A 3D nanomesh is fabricated in one step by scalable electrospinning of low‐cost polystyrene solutions. Optimal structures are composed of a mesh of dense nanofiber layers vertically separated by isolated mesoporous microbeads. This results in a highly adhesive superhydrophobic wetting that perfectly mimics rose petal‐like structures. Structural–functional correlations are obtained over all key process parameters enabling robust tailoring of the wetting properties from hydrophilic to lotus‐like Cassie‐Baxter and rose‐like Cassie‐impregnating states. A mechanistic model of the droplet adhesion and release dynamics is obtained alongside the first demonstration of a mechanically induced transfer of microdroplets between two superhydrophobic coatings. This low‐temperature reaction‐free material structure demonstrates a facile means to fabricate impenetrable residue‐less rose petal‐like surfaces with superhydrophobic contact angles of 152 ± 2° and effective adhesion strength of 113 ± 20 μN. This is a significant step toward parallel, multistep droplet manipulation with applications ranging from flexible on‐paper devices to microfluidics and portable/wearable biosensors.     

Locomotion of autistic adults

OBJECTIVE: To assess gait in patients with autism. DESIGN: Clinical and physiologic assessment. SETTING: Research hospital. PATIENTS AND SUBJECTS: Five adults with autism and five healthy, age-matched control subjects. MAIN OUTCOME MEASURE(S): Clinical and biomechanical assessment. RESULTS: Clinical assessment showed mild clumsiness in four patients and upper limb posturing during gait in three patients. The velocity of gait, step length, cadence, step width, stance time, and vertical ground reaction forces were normal in all patients. The only significant abnormality was decreased range of motion of the ankle. Some patients exhibited slightly decreased knee flexion in early stance. Clinically, the gait appeared to be irregular in three patients, but the variability was not significantly increased. CONCLUSIONS: The findings in patients with autism indicate a nonspecific, neurological disturbance involving the motor system. The normal velocity of gait and the normal step length argue against a parkinsonian-type disturbance, whereas the clinical picture suggests a disturbance of the cerebellum.     

Functional connectivity of the angular gyrus in normal reading and dyslexia

The classic neurologic model for reading, based on studies of patients with acquired alexia, hypothesizes functional linkages between the angular gyrus in the left hemisphere and visual association areas in the occipital and temporal lobes. The angular gyrus also is thought to have functional links with posterior language areas (e.g., Wernicke's area), because it is presumed to be involved in mapping visually presented inputs onto linguistic representations. Using positron emission tomography , we demonstrate in normal men that regional cerebral blood flow in the left angular gyrus shows strong within-task, across-subjects correlations (i.e., functional connectivity) with regional cerebral blood flow in extrastriate occipital and temporal lobe regions during single word reading. In contrast, the left angular gyrus is functionally disconnected from these regions in men with persistent developmental dyslexia, suggesting that the anatomical disconnection of the left angular gyrus from other brain regions that are part of the "normal" brain reading network in many cases of acquired alexia is mirrored by its functional disconnection in developmental dyslexia.     

Current trends in modelling research for turbulent aerodynamic flows

The engineering tools of choice for the computation of practical engineering flows have begun to migrate from those based on the traditional Reynolds-averaged Navier-Stokes approach to methodologies capable, in theory if not in practice, of accurately predicting some instantaneous scales of motion in the flow. The migration has largely been driven by both the success of Reynolds-averaged methods over a wide variety of flows and the inherent limitations of the method itself. Practitioners, emboldened by their ability to predict a wide variety of statistically steady equilibrium turbulent flows, have now turned their attention to flow control and non-equilibrium flows, i.e. separation control. This review gives some current priorities in traditional Reynolds-averaged modelling research as well as some methodologies being applied to a new class of turbulent flow control problem.