An Examination of Fine Motor Control In Children with ADHD

Attention-Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by symptoms of inattention, hyperactivity impulsivity, or both. Although fine motor difficulties are frequently found in children diagnosed with ADHD, often they are not identified and are undertreated. The present study examined fine motor control in children with ADHD in several ways, including through the use of digitizing technology, and compared it to that of control children. Thirty-eight children with ADHD and 28 control children in grades four through eight were administered a measure of handwriting (Test of Handwriting Skills - Revised; THS-R), a pattern completion task (Repeated Patterns Test; RPT), and a measure of fine motor skills (Bruininks Oseretsky Test of Motor Proficiency - Second Edition; BOT-2) on a digitizing tablet. Groups were compared on peak vertical velocity, variability of peak vertical velocity, normalized jerk, and mean stylus pressure. Results of the present study indicated that better quality of writing was associated with slower writing speed in children with ADHD, whereas in control children better quality writing was associated with greater stylus pressure, slower writing speed, and less variability in writing speed. No group differences were found on either a measure of fluency or stylus pressure when examining children\u27s writing between different levels of constraint. Both groups demonstrated the most fluent writing between 2 cm spaced lines, which appear to represent a level that facilitates the maximal amount of writing fluency in children in grades four through eight. Lastly, results indicated that there were no stylus pressure differences between groups for either novel or motorically complex material

Mix design considerations of foamed bitumen mixtures with reclaimed asphalt pavement material

In the present work, a mix design parametric study was carried out with the aim of proposing a practical and consistent mix design procedure for foamed bitumen mixtures (FBMs). The mix design parameters that were adopted in the study are mixing and compaction water content (MWC), compaction effort using a gyratory compactor and aggregate temperature. This parametric study was initially carried out on FBMs with virgin limestone aggregate without reclaimed asphalt pavement (RAP) material and a mix design procedure was proposed. This proposed methodology was also found to apply to FBMs with RAP. A detailed consideration was also given to characterising the RAP material so as to understand its contribution to the mechanical properties of FBMs. Optimum MWC was achieved by optimising mechanical properties such as indirect tensile stiffness modulus and indirect tensile strength (ITS-dry and ITS-wet). A rational range of 75–85% of optimum water content obtained by the modified Proctor test was found to be the optimum range of MWC that gives optimum mechanical properties for FBMs. It was also found that the presence of RAP influenced the design foamed bitumen content, which means that treating RAP as black rock in FBM mix design is not appropriate. To study the influence of bitumen and water during compaction, modified Proctor compaction and gyratory compaction were employed on mixes with varying amounts of water and bitumen. By this, the work also evaluated the validity of the total fluid (water + bitumen) concept that is widely used in bitumen–emulsion-treated mixes, and found it not to be applicable

Predation on an Upper Trophic Marine Predator, the Steller Sea Lion: Evaluating High Juvenile Mortality in a Density Dependent Conceptual Framework

The endangered western stock of the Steller sea lion (Eumetopias jubatus) – the largest of the eared seals – has declined by 80% from population levels encountered four decades ago. Current overall trends from the Gulf of Alaska to the Aleutian Islands appear neutral with strong regional heterogeneities. A published inferential model has been used to hypothesize a continuous decline in natality and depressed juvenile survival during the height of the decline in the mid-late 1980's, followed by the recent recovery of juvenile survival to pre-decline rates. However, these hypotheses have not been tested by direct means, and causes underlying past and present population trajectories remain unresolved and controversial. We determined post-weaning juvenile survival and causes of mortality using data received post-mortem via satellite from telemetry transmitters implanted into 36 juvenile Steller sea lions from 2005 through 2011. Data show high post-weaning mortality by predation in the eastern Gulf of Alaska region. To evaluate the impact of such high levels of predation, we developed a conceptual framework to integrate density dependent with density independent effects on vital rates and population trajectories. Our data and model do not support the hypothesized recent recovery of juvenile survival rates and reduced natality. Instead, our data demonstrate continued low juvenile survival in the Prince William Sound and Kenai Fjords region of the Gulf of Alaska. Our results on contemporary predation rates combined with the density dependent conceptual framework suggest predation on juvenile sea lions as the largest impediment to recovery of the species in the eastern Gulf of Alaska region. The framework also highlights the necessity for demographic models based on age-structured census data to incorporate the differential impact of predation on multiple vital rates

The Effects of Handling and Anesthetic Agents on the Stress Response and Carbohydrate Metabolism in Northern Elephant Seals

Free-ranging animals often cope with fluctuating environmental conditions such as weather, food availability, predation risk, the requirements of breeding, and the influence of anthropogenic factors. Consequently, researchers are increasingly measuring stress markers, especially glucocorticoids, to understand stress, disturbance, and population health. Studying free-ranging animals, however, comes with numerous difficulties posed by environmental conditions and the particular characteristics of study species. Performing measurements under either physical restraint or chemical sedation may affect the physiological variable under investigation and lead to values that may not reflect the standard functional state of the animal. This study measured the stress response resulting from different handling conditions in northern elephant seals and any ensuing influences on carbohydrate metabolism. Endogenous glucose production (EGP) was measured using [6-3H]glucose and plasma cortisol concentration was measured from blood samples drawn during three-hour measurement intervals. These measurements were conducted in weanlings and yearlings with and without the use of chemical sedatives—under chemical sedation, physical restraint, or unrestrained. We compared these findings with measurements in adult seals sedated in the field. The method of handling had a significant influence on the stress response and carbohydrate metabolism. Physically restrained weanlings and yearlings transported to the lab had increased concentrations of circulating cortisol (F11, 46 = 25.2, p<0.01) and epinephrine (F3, 12 = 5.8, p = 0.01). Physical restraint led to increased EGP (t = 3.1, p = 0.04) and elevated plasma glucose levels (t = 8.2, p<0.01). Animals chemically sedated in the field typically did not exhibit a cortisol stress response. The combination of anesthetic agents (Telazol, ketamine, and diazepam) used in this study appeared to alleviate a cortisol stress response due to handling in the field without altering carbohydrate metabolism. Measures of hormone concentrations and metabolism made under these conditions are more likely to reflect basal values

PLBD: protein–ligand binding database of thermodynamic and kinetic intrinsic parameters

We introduce a protein–ligand binding database (PLBD) that presents thermodynamic and kinetic data of reversible protein interactions with small molecule compounds. The manually curated binding data are linked to protein–ligand crystal structures, enabling structure–thermodynamics correlations to be determined. The database contains over 5500 binding datasets of 556 sulfonamide compound interactions with the 12 catalytically active human carbonic anhydrase isozymes defined by fluorescent thermal shift assay, isothermal titration calorimetry, inhibition of enzymatic activity and surface plasmon resonance. In the PLBD, the intrinsic thermodynamic parameters of interactions are provided, which account for the binding-linked protonation reactions. In addition to the protein–ligand binding affinities, the database provides calorimetrically measured binding enthalpies, providing additional mechanistic understanding. The PLBD can be applied to investigations of protein–ligand recognition and could be integrated into small molecule drug design

Lateral and cross-well transport of highly and moderately excited carriers in Si1-xGex/Si superlattices

Picosecond transient reflectometry and dynamic grating techniques have been applied to investigate the perpendicular and parallel transport of optically excited carriers in strained-layer Si0.83Ge0.17/Si superlattices. We present results of the carrier ambipolar diffusivity and effective lifetime measurements in the layered structure and substrate within the 10(17)-10(20) cm(-3) density range. The combined experimental data are discussed in terms of parallel and perpendicular diffusion of carriers, interface recombination, and lattice heating. The estimated lateral and cross-well diffusion constants are 10 and 0.16 cm(2)/s at room temperature, respectively. (C) 1998 American Institute of Physics

Stimulated emission of optically excited MOVPE grown ZnCdSe-ZnSe GRINSCH quantum well

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