Novel form of adaptation in mouse retinal rods speeds recovery of phototransduction

Photoreceptors of the retina adapt to ambient light in a manner that allows them to detect changes in illumination over an enormous range of intensities. We have discovered a novel form of adaptation in mouse rods that persists long after the light has been extinguished and the rod's circulating dark current has returned. Electrophysiological recordings from individual rods showed that the time that a bright flash response remained in saturation was significantly shorter if the rod had been previously exposed to bright light. This persistent adaptation did not decrease the rate of rise of the response and therefore cannot be attributed to a decrease in the gain of transduction. Instead, this adaptation was accompanied by a marked speeding of the recovery of the response, suggesting that the step that rate-limits recovery had been accelerated. Experiments on knockout rods in which the identity of the rate-limiting step is known suggest that this adaptive acceleration results from a speeding of G protein/effector deactivation

Precessionless spin transport wire confined in quasi-two-dimensional electron systems

We demonstrate that in an inversion-asymmetric two-dimensional electron system 2DES with both Rashba and Dresselhaus spin-orbit couplings taken into account, certain transport directions on which no spin precession occurs can be found when the injected spin is properly polarized. By analyzing the expectation value of spin with respect to the injected electron state on each space point in the 2DES, we further show that the adjacent regions with technically reachable widths along these directions exhibit nearly conserved spin. Hence a possible application in semiconductor spintronics, namely, precessionless spin transport wire, is proposed.Comment: 3 pages, 4 figures, to be appeared in Journal of Applied Physics, Proceedings of the 50th MMM Conferenc

Dual task measures in older adults with and without cognitive impairment: Response to simultaneous cognitive-exercise training and minimal clinically important difference estimates

BACKGROUND: Responsiveness and minimal clinically important difference (MCID) are critical indices to understand whether observed improvement represents a meaningful improvement after intervention. Although simultaneous cognitive-exercise training (SCET; e.g., performing memory tasks while cycling) has been suggested to enhance the cognitive function of older adults, responsiveness and MCID have not been established. Hence, we aimed to estimate responsiveness and MCIDs of two dual task performance involving cognition and hand function in older adults with and without cognitive impairment and to compare the differences in responsiveness and MCIDs of the two dual task performance between older adults with and without cognitive impairment. METHODS: A total of 106 older adults completed the Montreal Cognitive Assessment and two dual tasks before and after SCET. One dual task was a combination of Serial Sevens Test and Box and Block Test (BBT), and the other included frequency discrimination and BBT. We used effect size and standardized response mean to indicate responsiveness and used anchor- and distribution-based approaches to estimating MCID ranges. When conducting data analysis, all participants were classified into two cognitive groups, cognitively healthy (Montreal Cognitive Assessment ≥ 26) and cognitively impaired (Montreal Cognitive Assessment \u3c 26) groups, based on the scores of the Montreal Cognitive Assessment before SCET. RESULTS: In the cognitively healthy group, Serial Seven Test performance when tasked with BBT and BBT performance when tasked with Serial Seven Test were responsive to SCET (effect size = 0.18-0.29; standardized response mean = 0.25-0.37). MCIDs of Serial Seven Test performance when tasked with BBT ranged 2.09-2.36, and MCIDs of BBT performance when tasked with Serial Seven Test ranged 3.77-5.85. In the cognitively impaired group, only frequency discrimination performance when tasked with BBT was responsive to SCET (effect size = 0.37; standardized response mean = 0.47). MCIDs of frequency discrimination performance when tasked with BBT ranged 1.47-2.18, and MCIDs of BBT performance when tasked with frequency discrimination ranged 1.13-7.62. CONCLUSIONS: Current findings suggest that a change in Serial Seven Test performance when tasked with BBT between 2.09 and 2.36 corrected number (correct responses - incorrect responses) should be considered a meaningful change for older adults who are cognitively healthy, and a change in frequency discrimination performance when tasked with BBT between 1.47 and 2.18 corrected number (correct responses - incorrect responses) should be considered a meaningful change for older adults who are cognitively impaired. Clinical practitioners may use these established MCIDs of dual tasks involving cognition and hand function to interpret changes following SCET for older adults with and without cognitive impairment. TRIAL REGISTRATION: NCT04689776, 30/12/2020

Use of CD-ROMs in Spanish Libraries

A study was carried out in public, academic, special and government libraries and info rmati on centres in Western Europe during 1989 on the use of CD - ROMs and optical products. Following a brief account of the background to the survey, the paper analyses the results in more depth for libraries and information centres in Spain and compare, theee reeults where relevant with the overall total European response as well as those from individual countriea. lt is evident that optical products in general and CD - ROMs in particular are not yet in widespread use in libraries.Se llevó a cabo un estudio acerca de la utilización del CD-ROM en las bibliotecas públicas, académicas y centros de documentación de los países de Europa Occidental durante 1989. Se analizan con más detenimiento los resultados obtenidos en bibliotecas españolas, comparándolas con el resto de Europa, llegándose a la conclusión de que los productos ópticos en general, y el CD-ROM en particular no se emplean habitualmente en las bibliotecas española

Personality Facets and Customer Loyalty in Online Games

Online games have attracted numerous customers and brought stable revenues to game providers. However, some customers frequently switch to other games, and thus, it is important to identify which customers are likely loyal customers. The literature has identified openness, conscientiousness, and extraversion as predictors for loyalty in online games (Teng, Huang, Jeng, Chou, & Hu, 2008). However, the three broad traits contain multiple facets. Thus research addressing the three broad traits may mix the influences of multiple facets. Thus this study investigates the influences of personality facets on online game customer skill, challenge, flow experience, and loyalty. The sample comprised 994 online gamers. This study employed structural equation modeling for analysis, and found that (1) ideas and achievement striving are positively related to skill, (2) achievement striving, competence, and excitement-seeking are positively related to challenge, (3) gregariousness is positively related to interdependence, (4) fantasy, skill, challenge, and interdependence are positively related to customer likelihood of experiencing flow, and (5) experienced flow is positively related to customer loyalty. The study findings suggest managers improve gamer skill and challenge when gamers are in their early stages in online games, boosting their likelihood of experiencing flow and thus building their loyalty. Managers are also suggested to target individuals who are high in personality facets such as ideas, achievement striving, competence, excitement- seeking, to effectively build a loyal customer base. Educators are also suggested to notice students who are high in those personality facets, because these students may continuously play online games when they begin to play

Modeling the dynamic characteristics of human ossicles

The dynamic characteristics of human ossicle responses to stimulus frequencies of 125 Hz, 250 Hz, 500 Hz, 750 Hz, 1 kHz, 2 kHz, 3 kHz, 4 kHz, 5 kHz, 6 kHz, 7 kHz and 8 kHz were analyzed using a 3D image model that was constructed using the finite element method. The 3D image model of the ossicle chain was based on images previously obtained from highresolution computed tomography (CT) scans of the middle ear region of patients. The displacement at the footplate in the 3D model showed essentially no response when the ossicles were subjected to sound stimuli with frequencies above 2 kHz. However, the ossicles responded to sound stimuli with frequencies below 1 kHz, and the vibration of the ossicles was equivalent to the amplitude of the sound stimuli

Assessment, Evaluation, and Programming System for Infants and Children: What are Salient Development and Research Factors to Consider?

Early childhood professionals are increasingly pressed to use evidence-based measures when assessing young children. Professional time and resources to investigate research is limited, and takes time away from the delivery of direct services. The literature review is to describe the progression of a widely used curriculum-based assessment (CBA), the Assessment, Evaluation, and Programming System for Infants and Children (AEPS). In addition to sharing the development of this early childhood measure, we identified 19 studies from the available research found in various databases that have investigated the evidence supporting the use of this measure. Findings have implications for the validity, reliability, and utility of the AEPS

A Perfect Match Condition for Point-Set Matching Problems Using the Optimal Mass Transport Approach

We study the performance of optimal mass transport--based methods applied to point-set matching problems. The present study, which is based on the L2 mass transport cost, states that perfect matches always occur when the product of the point-set cardinality and the norm of the curl of the nonrigid deformation field does not exceed some constant. This analytic result is justified by a numerical study of matching two sets of pulmonary vascular tree branch points whose displacement is caused by the lung volume changes in the same human subject. The nearly perfect match performance verifies the effectiveness of this mass transport--based approach.Read More: http://epubs.siam.org/doi/abs/10.1137/12086443