Pain-Related Anxiety in the Prediction of Chronic Low-Back Pain Distress

This study evaluated the relation of particular aspects of pain-related anxiety to characteristics of chronic pain distress in a sample of 76 individuals with low-back pain. Consistent with contemporary cognitive-behavioral models of chronic pain, the cognitive dimension of the Pain Anxiety Symptoms Scale (PASS; McCracken, Zayfert, and Gross, 1992, Pain 50:67-73) was uniquely predictive of cognitive-affective aspects of chronic pain, including affective distress, perceived lack of control, and pain severity. In contrast, the escape and avoidance dimension of the PASS was more predictive of behavioral interference in life activities. Overall, the findings are discussed within the context of identifying particular pain-related anxiety mechanisms contributing to differential aspects of pain-related distress and clinical impairment.     

Visual attention in adults with developmental dyslexia: Evidence from manual reaction time and saccade latency

Two studies were conducted to investigate visual attention deficits in dyslexia. In Experiment 1, adults with dyslexia and age- and IQ-matched controls completed a simple cueing task; participants responded to briefly presented (20 ms) eccentric targets (3°, 6°, or 9°) with a key press. In Experiment 2, the same participants completed a saccade version of the task, and saccade amplitude, accuracy, and latency were measured. The results revealed comparable performance between the groups on the manual reaction time task. The groups also performed similarly in saccade accuracy and latency. Moreover, neither group showed a visual field asymmetry in their performance, with the exception that adults with dyslexia showed longer saccade latency for 9° targets presented to their left visual field than did controls. However, on the latter measure, the majority (78%) of those with dyslexia performed within the range of the control group. Correlational analyses revealed associations between reading and phoneme awareness in both groups, but phoneme awareness was not associated with visual attention in adult dyslexics. Together, the results are not compatible with a visual attention deficit in adult dyslexia, while they provide support for the phonological deficit hypothesis.     

Lamellar stack formation and degradative behaviors of hydrolytically degraded poly(ε-caprolactone) and poly(glycolide-ε-caprolactone) blended fibers

Electrospun fibrous mats have gained popularity in bioengineering over the past decade, but few papers detail their degradative mechanisms. To address this, blends of hydrophobic poly(ε-caprolactone) (PCL) and hydrophilic PGA-PCL-PGA triblock copolymer were electrospun into aligned fibrous mats to assess the copolymers' mechanical and degradative properties. Increased hydrophilic triblock content led to enhanced morphological uniformity of fiber, tightening of fiber diameters, increased storage and Young's modulus, and decreased elongation. The corresponding decrease in hydrophobic PCL content led to faster hydrolytic degradation rate, as reflected by enhanced decrease in mass, molecular weight, and modulus loss at 25, 37, and 45°C. The activation energy for hydrolytic degradation for 15:85 PCL: triblock copolymer was approximately half that of 85:15 PCL: triblock copolymer. Detailed examination of fiber morphology and crystallinity revealed initial surface erosion followed by the evolution of crystalline lamellar stacks and bulk degradation at 37°C. Because of the high surface to volume and short diffusion length scale of the small diameter fibers, surface and bulk degradation may both contribute to the hydrolytic degradative behavior of these electrospun fibrous mats. Electrospun mats' distinct architecture that embodies high specific surface to volume and interfiber porous ultrastructures that lead to their unique degradative behaviors hold much potential for significant impact in the field of tissue engineering and controlled drug delivery.