The Psychophysical Assessment of Hierarchical Magno-, Parvo- and Konio-Cellular Visual Stream Dysregulations in Migraineurs.

Introduction: Although conscious, image-forming illusions have been noted in migraine, few studies have specifically sought to collectively evaluate the role of all three parallel visual processing streams in the retinogeniculostriate pathway involved with image-forming vision and their implications in the development of migraine symptoms.

Methods: We psychophysically assessed the functionality of the inferred magnocellular (MC), parvocellular (PC), and koniocellular (KC) streams at different hierarchical loci across three clinical groups: individuals who experience migraine with aura (MA; n=13), experience migraine without aura (MWO; n=14), and Controls (n=15). Participants completed four experiments: Experiment 1 designed to assess retinal short-wavelength-sensitive (S-) cone sensitivities; Experiment 2 intended to measure postretinal temporal and spatiochromatic contrast sensitivities; Experiment 3 intended to assess postretinal spatiotemporal achromatic contrast sensitivities; and Experiment 4 designed to measure thalamocortical color discriminations along the three cone-excitation axes.

A Pilot Study Evaluating the Effectiveness of Platelet-Rich Plasma Therapy for Treating Degenerative Tendinopathies: A Randomized Control Trial with Synchronous Observational Cohort.

Objective: This pilot study aimed to inform future research evaluating the effectiveness of Platelet Rich Plasma (PRP) injection for tendinopathy.

Design: Randomized control trial (RCT) and synchronous observational cohort studies. For the RCT, consecutive consenting patients treated at an academic sports medicine clinic were randomly assigned to either a PRP or placebo control group.

How learning transfers: a study of how graduates of a faculty education fellowship influenced the behaviors and practices of their peers and organizations.

Purpose: Faculty development programs have been criticized for their limited assessment methods, focused only on the learners and limited to satisfaction measures or self-reported behavior changes. Assessment of organizational impact is lacking. This study explored the impact of faculty education fellowship graduates on their organization and how that impact occurred.

Long-term sequelae of electrical injury.

Objective: To summarize the current evidence-based knowledge about the long-term sequelae of injuries from electrical current.

Quality Of Evidence: MEDLINE was searched for English-language articles published in the past 20 years using the following search terms: electrical, injuries, wound, trauma, accident, sequelae, long-term, follow-up, and aftereffects. For obvious reasons, it is unethical to randomly study electrical injury in controlled clinical trials.

Implementing the leadership development plans of faculty education fellows: a structured approach.

The literature about medical education faculty fellowship programs, which have grown in popularity, quantifies program characteristics, provides exemplars, and reports on delivery strategies. Evaluation is generally limited to satisfaction measures, with a few longitudinal studies of postprogram achievements, but none on the process of making these changes.The authors describe the development of faculty members' postfellowship leadership plans and a structured process to support plan implementation.

Double-phase conjugate mirror in nominally undoped Sn2P2S6.

Coherent oscillation is achieved in the geometry of a double-phase conjugate mirror in nominally undoped Sn2P2S6 with 647 nm radiation of a Kr+ laser. The specific temporal dynamics of oscillation with modulated intensity and periodic 0-pi-0-pi variations of the oscillation wave phase is similar to that observed earlier using a semilinear oscillator geometry. The described oscillator ensures submillisecond delay time in the appearance of the phase conjugate wave.

Observation of bright spatial photorefractive solitons in a planar strontium barium niobate waveguide.

We have obtained stationary bright spatial solitons in a planar photorefractive strontium barium niobate waveguide for visible light ranging from 514.5 to 780 nm. Even for larger wavelengths (lambda=1047 nm) strong self-focusing of the beam was observed; however, input power had to be some orders of magnitude higher than for visible light for self-focusing to occur.

Contrast sensitivity in seasonal and nonseasonal depression.

Background: Psychophysics has been used for the early diagnosis of many diseases that affect the visual pathway including those not usually considered vision-related (e.g., Parkinson's disease).

An evaluation of Think First Saskatchewan: a head and spinal cord injury prevention program.

Objectives: To identify youth behaviour with regards to injury prevention, to assess the awareness of severity and susceptibility to brain and spinal cord injury, and to evaluate the impact of the Think First Saskatchewan school visit program on students' knowledge of brain and spinal cord injury prevention.

Methods: A controlled, pre- and post-test design, self-report questionnaire was administered to 1,257 grade 6 and 7 students. Descriptive statistics and chi-square were used for data analysis.

Temporal development of photorefractive solitons up to telecommunication wavelengths in strontium-barium niobate waveguides.

We experimentally investigate the temporal development of photorefractive solitons in strontium-barium niobate waveguides at visible and infrared wavelengths. The development times in the infrared are shown to be comparable with those in the visible. The results are compared with predictions of a previously published model.

Dimerization of the Epstein-Barr virus ZEBRA protein in the yeast two-hybrid system. Comparison Of a ZEBRA variant with the B95-8 form.

Epstein-Barr virus (EBV) is a herpes virus associated with several human tumors. The EBV protein, ZEBRA, is a transactivator of the basic leucine zipper family (bZip). It binds to specific sequences on DNA and is able to interact with cellular proteins such as p53.

Color perception within a chromatic context: the effect of short-wavelength light on color appearance.

Light at the boundary of a uniform test field (contrast) has a qualitatively different effect on color perception than light in more remote noncontiguous regions (context). Basic properties of color perception with contextual short-wavelength light are assessed here with a 1 degree test field surrounded by either contiguous or noncontiguous 440 or 491 nm light (32 td). Contrasting stimuli are 3 or 5 degrees adapting fields, a thin 1 degree i.

Color perception within a chromatic context: changes in red/green equilibria caused by noncontiguous light.

We measured changes in the color appearance of one light caused by another light presented in a well-separated region. Observers viewed a 1 degrees test field superimposed on a 3 degrees, 540 or 660 nm adapting field (32 or 320 td). The change in appearance due to noncontiguous light was determined by surrounding the 3 degrees adapting field with a continguous 3 degrees i.

Foveal cone detection statistics in color-normals and dichromats.

We measured for six male observers, the psychometric functions for the detection of two simultaneously presented points of light. The test stimuli were two 1 min point sources separated by 17 min arc, and pulsed for 0.5 msec.

Muscarine receptor types mediating autoinhibition of acetylcholine release and sphincter contraction in the guinea-pig iris.

The potencies of several muscarine receptor antagonists in blocking either the autoinhibition of acetylcholine release or the muscarinic contraction of the sphincter muscle upon acetylcholine release were investigated in the guinea-pig iris. The agonist at pre- or postjunctional muscarine receptors was acetylcholine released upon field stimulation (5.5 Hz, 2 min) of the irides preloaded with 14C-choline.

Different muscarine receptors mediate the prejunctional inhibition of [3H]-noradrenaline release in rat or guinea-pig iris and the contraction of the rabbit iris sphincter muscle.

To investigate the muscarine receptor type mediating inhibition of [3H]-noradrenaline release from the isolated rat and guinea-pig iris we have determined the potency of antimuscarinic drugs to antagonize the methacholine-induced inhibition of [3H]-noradrenaline overflow evoked by field stimulation (3 Hz, 2 min). The prejunctional apparent affinities were compared with those obtained for postjunctional muscarine receptors mediating the methacholine-induced contraction of the isolated rabbit iris sphincter muscle. Prejunctional apparent affinity constants of pirenzepine (6.

Instrument myopia conceptions, misconceptions, and influencing factors.

The literature on instrument myopia is reviewed, with the review organized around three principal objectives. One is to describe and discuss various factors that may influence the degree to which instrument myopia is manifested, including monocular vs. binocular viewing, age, direction of focus, illumination level, fatigue, magnification, astigmatic variations, optical decentration, perceived proximity of the target and peripheral surround, and experience.

Comparison of subjective lens preference to objective refractive error measurements in pigtail macaques.

Two measurements can be taken to determine the refractive error in human beings: a subjective, lens preference measurement and objective retinoscopy. This study determined the subjective refractive error in eight pigtailed monkeys by placing lenses of different powers in front of peepholes in a solid wall cage and recording the amount of time each subject used the holes. Retinoscopy measurements were then taken and compared to the subjective findings to determine the degree of similarity between these two refraction methods.

Overaccommodation, underaccommodation, and the clinical phoropter: a study of instrument myopia and related effects.

To explore the degree to which a phoropter can induce overaccommodation (instrument myopia) and/or underaccommodation , 19 college-age subjects participated in a series of measurements of accommodation response. Accommodation responses were assessed while subjects looked through a phoropter (both with standard 19-mm viewing apertures and through 2-mm artificial pupils) and when no phoropter was present. Subjects were tested both monocularly and binocularly, and under three stimulus conditions (near target, far target, and total darkness).