Self-Reported Visual Ability Versus Task Performance in Individuals With Ultra-Low Vision.

Purpose: Visual functioning questionnaires are commonly used as patient-reported outcome measures to estimate visual ability. Performance measures, on the other hand, provide a direct measure of visual ability. For individuals with ultra-low vision (ULV; visual acuity (VA) <20/1600), the ultra-low vision visual functioning questionnaire (ULV-VFQ) and the Wilmer VRI-a virtual reality-based performance test-estimate self-reported and actual visual ability, respectively, for activities of daily living. But how well do self-reports from ULV-VFQ predict actual task performance in the Wilmer VRI? Methods: We administered a subset of 10 matching items from the ULV-VFQ and Wilmer VRI to 27 individuals with ULV. We estimated item measures (task difficulty) and person measures (visual ability) using Rasch analysis for ULV-VFQ and using latent variable signal detection theory for the Wilmer VRI. We then used regression analysis to compare person and item measure estimates from self-reports and task performance. Results: Item and person measures were modestly correlated between the two instruments, with r2 = 0.47 (P = 0.02) and r2 = 0.36 (P = 0.001), demonstrating that self-reports are an imperfect predictor of task difficulty and performance. Conclusions: While self-reports impose a lower demand for equipment and personnel, actual task performance should be measured to assess visual ability in ULV. Translational Relevance: Visual performance measures should be the preferred outcome measure in clinical trials recruiting individuals with ULV. Virtual reality can be used to standardize tasks.

Semaphorin3A/PlexinA3 association with the Scribble scaffold for cGMP increase is required for apical dendrite development.

The development of the apical dendrite from the leading process of the bipolar pyramidal neuron might be directed by spatially organized extrinsic cues acting on localized intrinsic determinants. The extracellular cues regulating apical dendrite polarization remain elusive. We show that leading process and apical dendrite development are directed by class III Semaphorins and mediated by a localized cGMP-synthesizing complex. The scaffolding protein Scribble that associates with the cGMP-synthesizing enzyme soluble guanylate cyclase (sGC) also associates with the Semaphorin3A (Sema3A) co-receptor PlexinA3. Deletion or knockdown of PlexinA3 and Sema3A or disruption of PlexinA3-Scribble association prevents Sema3A-mediated cGMP increase and causes defects in apical dendrite development. These manipulations also impair bipolar polarity and leading process establishment. Local cGMP elevation or sGC expression rescues the effects of PlexinA3 knockdown or PlexinA3-Scribble complex disruption. During neuronal polarization, leading process and apical dendrite development are directed by a scaffold that links Semaphorin cue to cGMP increase.

Effect of amyloglucosidase hydrolysis on the multi-scale supramolecular structure of corn starch.

The effects of amyloglucosidase digestion on the multi-scale supramolecular structural changes of native corn starch were examined by ultra-small angle neutron scattering (USANS), small angle X-ray scattering (SAXS), particle sizing, and scanning electron microscopy (SEM). Well-defined and spherical pores were formed upon amyloglucosidase digestion as revealed by SEM. The pore polydispersity was determined using USANS by assuming spherical pore morphology with log-normal distribution. Both USANS and SEM measurements demonstrated that the pores become larger and more polydisperse as the digestion time increased. Moreover, SAXS revealed that the lamellar peak area decreased gradually for both thermally and enzymatically treated starches, indicating partial loss of lamellar organisation. Overall, the results demonstrate structural changes occur on multiple length scales upon enzymatic digestion from granular to lamellar with small-angle scattering demonstrated to provide detailed characterization of the resultant microporous structures.