Loss of αA or αB-Crystallin Accelerates Photoreceptor Cell Death in a Mouse Model of P23H Autosomal Dominant Retinitis Pigmentosa

Inherited retinal degenerations (IRD) are a leading cause of visual impairment and can result from mutations in any one of a multitude of genes. Mutations in the light-sensing protein rhodopsin (RHO) is a leading cause of IRD with the most common of those being a missense mutation that results in substitution of proline-23 with histidine. This variant, also known as P23H-RHO, results in rhodopsin misfolding, initiation of endoplasmic reticulum stress, the unfolded protein response, and activation of cell death pathways. In this study, we investigate the effect of α-crystallins on photoreceptor survival in a mouse model of IRD secondary to P23H-RHO. We find that knockout of either αA- or αB-crystallin results in increased intraretinal inflammation, activation of apoptosis and necroptosis, and photoreceptor death. Our data suggest an important role for the ⍺-crystallins in regulating photoreceptor survival in the P23H-RHO mouse model of IRD.     

Exploring regression structure with graphics

Summary We investigate the extent to which it may be possible to carry out a regression analysis using graphics alone, an idea that we refer to asgraphical regression. The limitations of this idea are explored. It is shown that graphical regression is theoretically possible with essentially no constraints on the conditional distribution of the response given the predictors, but with some conditions on marginal distribution of the predictors. Dimension reduction subspaces and added variable plots play a central role in the development. The possibility of useful methodology is explored through two examples. Read before the Spanish Statistical Society at a meeting organized by the Carlos III University of Madrid on Wednesday, April 21, 1993     

Performance of upgraded JET neutral beam injectors

The JET neutral beam injection (NBI) system is undergoing an upgrade of both beam power and pulse duration, which will be completed in 2011. In order to obtain an early assessment of the performance of the upgraded injectors, two positive ion neutral injectors (PINIs) with modified ion source and accelerator configuration were installed on Octant 8 Neutral Injector Box and successfully commissioned in summer 2009. Both PINIs were routinely delivering ～2 MW of deuterium neutral beam power during the JET experimental campaign in autumn 2009. These early tests allowed us to predict with confidence that the JET NBI upgrade objective of injecting 34 MW of total deuterium neutral beam power into the JET plasma will be achieved.     

A limit on retrieval-induced forgetting.

Retrieving some members of a memory set impairs later recall of semantically related but not unrelated members (M. C. Anderson, R. A. Bjork, & E. L. Bjork, 1994; M. C. Anderson & B. A. Spellman, 1995). The authors investigated whether this retrieval-induced forgetting effect would generalize to testing procedures other than category-cued recall. Although the authors demonstrated a retrieval-induced forgetting effect using a category-cued recall task, they failed to show retrieval-induced forgetting on several different memory tests that used item-specific cues, including a category-plus-stem-cued recall test, a category-plus-fragment-cued recall test, a fragment-cued recall test, and a fragment completion task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microbial Sensory Rhodopsins: Photochemistry and Function

The review covers recent progress on microbial sensory rhodopsins, visual pigment-like retinylidene photoreceptors that function in phototaxis by archaeons, such as Halobacterium salinarium, and by unicellular eukaryotic algae, such as Chlamydomonas reinhardtii. Six demonstrably different sensory rhodopsins are known in halophilic archaea. The best characterized is sensory rhodopsin I (SR-I), a color-sensitive receptor that relays attractant and repellent photosignals to a tightly bound transducer protein HtrI (halobacterial transducer for sensory rhodopsin I). New advances in the mechanism of signal transduction by the SR-I/HtrI complex from molecular-biological and biophysical approaches are summarized. Effects of HtrI on light-induced proton transfers in the receptor are discussed for their possible role in signaling. Current knowledge concerning the growing family of related archaeal sensory rhodopsins is presented. The evidence for a sensory rhodopsin in phototaxis by C. reinhardtii and other unicellular eukaryotic algae is reviewed. The molecular information is more limited than for the archaeal organisms, but the physiological information is rich and complex. Compelling data exist for a single retinal-containing receptor mediating both phototaxis and photophobic responses in C. reinhardtii. From retinal analog studies, the isomeric configuration and ring/chain conformation of the retinal in the receptor appear to be identical to those of the archaeal sensory rhodopsins. Also, photoisomerization from all-trans- to 13-cis-retinal appears to be the trigger for signaling, as in the archaeal pigments. Conflicting early studies suggesting an 11-cis-retinal chromophore and signaling without photoisomerization are analyzed and possible explanations for those reports are suggested. As a general conclusion, the microbial sensory rhodopsins provide an opportunity to explore photochemistry and protein/protein interaction in photosensory transduction in genetically tractable organisms.     

Mental model organization.

Previous research (G. A. Radvansky and R. T. Zacks; see record 1992-04153-001) has shown that the fan effect is mediated not by the number of nominal associations paired with a concept but by the number of mental models into which related concepts are organized. Specifically, newly learned "facts" about different objects in one location are integrated into a single mental model and no fan effect is produced, whereas facts about one object in different locations are not integrated and a fan effect is produced. In 6 experiments the authors investigated several factors' influence on location-based organization preferences. No impact on either article type (definite or indefinite) or object transportability was found. However, animate sentence subjects (people) reduced preference for location-based organizations. A clear person-based organization emerged by using locations that typically contain only a single person (e.g., phone booth) to make location-based situations less plausible. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related differences in cognition: The role of distraction control.

The ability to ignore or control the processing of distracting information may underlie many age-related and individual differences in cognitive abilities. Using a large sample of adults aged 18 to 87 years, this article presents data examining the mediating role of distraction control in the relationship between age and higher order cognition. The reading with distraction task (Connelly, Hasher, & Zacks, 1991) has been used as a measure of the access function of distraction control. Results of this study suggest that distraction control, as measured by this paradigm, plays an important role in mediating age-related effects on measures of working memory and matrix reasoning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distributions of Sequential and Two-Stage Stopping Times for Fixed-Width Confidence Intervals in Bernoulli Trials: Application in Reliability

Abstract

Albert N. Shiryaev's reminiscence of 50-years old results is astonishing. They look much more modern than their age. Here, some notes on statistics literature peculiarities, a fix of the stationary density figure, and some relations to discrete time numerics are provided.     

Aging, distraction, and the benefits of predictable location.

Three experiments examined the impact on reading time for younger and older adults in the absence vs. presence of distraction (marked by font type) in either fixed predictable locations (Experiments 1 and 2) or unpredictable locations (Experiment 3) . Consistent with earlier work (S. L. Connelly, L. Hasher, & R. T. Zacks; see record 1992-18667-001), older adults were markedly disrupted, relative to young adults, when distraction was present in unpredictable locations. When the location of distraction was fixed, however, the very large disadvantage that older adults otherwise experienced (slowed by as much as 46 s) diminished substantially (to as little as 2 s). Fixed location also eliminated the relatedness effect, by which older adults are especially susceptible to distraction from meaningfully related material. (PsycINFO Database Record (c) 2010 APA, all rights reserved)