Quantum physical relevance of the Einstein tensor

Taking quantum physics as well as large scale astronomical observations into account, a spacetime metric is introduced, such that the nonlinear part of the Einstein tensor contains effects of the order of Planck's constant.Comment: to appear in Brazilian Journal of Physic

Driving with retinitis pigmentosa

Background: To establish the proportion of patients with retinitis pigmentosa (RP) meeting the Australian fitness to drive (FTD) visual standards. Methodology: A prospective consecutive case series of patients with a clinical or genetic diagnosis of RP. Data on age at symptom onset, current driving status, inheritance pattern, better eye visual acuity (BEVA), binocular Esterman visual field (BEVF) parameters, genotype and ability to meet the driving standards based on BEVA and BEVF were collected. Outcome measures included the proportion of RP patients overall meeting the standards and clinical predictors for passing. A sub-analysis was performed on those RP patients who reported to drive. Change in BEVA and BEVF parameters across age in specific genotype groups was assessed. Results: Overall, 228 patients with RP had a BEVF assessment. Only 39% (89/228) met the driving standards. Younger age at the time of testing was the only significant predictor (p \u3c 0.01) for passing. Of the 55% of RP patients who reported to drive, 52% (65/125) met the standards, decreasing to 14% in the 56- to 65-year-old age group. RP patients harbouring mutations in HK1 or RHO genes may have slower rates of decline in their VF parameters. Conclusion: Nearly 40% of RP patients met the driving standards. However, almost 50% of RP drivers were unaware of their failure to meet the current standards. BEVF testing is essential in the assessment of RP patients who are still driving. Phenotype and genotype predictors for passing the standards warrant further investigation. Abbreviation: FTD, fitness to drive; IRD, inherited retinal disease; RP, retinitis pigmentosa; RHO, rhodopsin; HK1, hexokinase 1; PRPF31 pre-mRNA processing factor 31; RPGR, retinitis pigmentosa GTPase regulator; VF, visual field; BEVA, better eye visual acuity; BEVF, binocular Esterman visual field

The 21Na(p,gamma)22Mg Reaction and Oxygen-Neon Novae

The 21Na(p,gamma)22Mg reaction is expected to play an important role in the nucleosynthesis of 22Na in Oxygen-Neon novae. The decay of 22Na leads to the emission of a characteristic 1.275 MeV gamma-ray line. This report provides the first direct measurement of the rate of this reaction using a radioactive 21Na beam, and discusses its astrophysical implications. The energy of the important state was measured to be E$_{c.m.}$= 205.7 $\pm$ 0.5 keV with a resonance strength $\omega\gamma = 1.03\pm0.16_{stat}\pm0.14_{sys}$ meV.Comment: Accepted for publication in Physical Review Letter

Veganism

Narrowly understood, veganism is the practice of excluding all animal products from one’s diet, with the exception of human milk. More broadly, veganism is not only a food ethics, but it encompasses all other areas of life. As defined by the Vegan Society when it became an established charity in the UK in 1979, veganism is best understood as “a philosophy and way of living which seeks to exclude – as far as is possible and practicable – all forms of exploitation of, and cruelty to, animals for food, clothing or any other purpose; and by extension, promotes the development and use of animal-free alternatives for the benefit of humans, animals and the environment”. There are two main moral justifications for veganism, both of which rely on a common assumption: that sentience, i.e., the capacity to feel pleasure and pain, is the necessary and sufficient trait to be morally considerable. In what follows, I present these two justifications and a third one which, although less popular, captures some core intuitions among vegans. I then present a challenge faced by veganism and two arguments that reject it as discriminatory, and briefly conclude

An extrinsic component parameter extraction method for high power RF LDMOS transistors

A new extrinsic network and extrinsic parameter extraction methodology is developed for high power RF LDMOS transistor modeling. This new method uses accurate manifold deembedding using electromagnetic simulation, and optimization of the extrinsic network parameter values over a broad frequency range. The new extrinsic network accommodates feedback effects which are observed in high power transistors. This improved methodology allows us to achieve a good agreement between measured and modeled S-parameters in the frequency range of 0.5 to 6 GHz for different bias conditions. Large-signal verification of this new model shows a very good match with measurements at 2.14 GHz. © 2008 IEEE

Genotype-specific lesion growth rates in stargardt disease

Reported growth rates (GR) of atrophic lesions in Stargardt disease (STGD1) vary widely. In the present study, we report the longitudinal natural history of patients with confirmed bial-lelic ABCA4 mutations from five genotype groups: c.6079C \u3e T, c.[2588G \u3e C;5603A \u3e T], c.3113C \u3e T, c.5882G \u3e A and c.5603A \u3e T. Fundus autofluorescence (AF) 30◦ × 30◦ images were manually seg-mented for boundaries of definitely decreased autofluorescence (DDAF). The primary outcome was the effective radius GR across five genotype groups. The age of DDAF formation in each eye was calculated using the x-intercept of the DDAF effective radius against age. Discordance between age at DDAF formation and symptom onset was compared. A total of 75 eyes from 39 STGD1 patients (17 male [44%]; mean ± SD age 45 ± 19 years; range 21–86) were recruited. Patients with c.3113C \u3e T or c.6079C \u3e T had a significantly faster effective radius GR at 0.17 mm/year (95% CI 0.12 to 0.22; p \u3c 0.001 and 0.14 to 0.21; p \u3c 0.001) respectively, as compared to those patients harbouring c.5882G \u3e A at 0.06 mm/year (95% CI 0.03–0.09), respectively. Future clinical trial design should consider the effect of genotype on the effective radius GR and the timing of DDAF formation relative to symptom onset

The narrative model of therapeutic change: an exploratory study tracking innovative moments and protonarratives using state space grids

Despite the popularity of narrative approaches to the change in psychotherapy, a better understanding of how narrative transformation facilitates therapeutic change is needed. Research on innovative moments (IMs) has explored how IMs in psychotherapy evolve over time. We expand on past studies by exploring how IMs become aggregated in narrative threads, termed protonarratives, which come to constitute an alternative self-narrative at the conclusion of therapy. The results suggest that the good outcome case had a different pattern of IM integration within protonarratives, revealing greater flexibility than the poor outcome case. These results support the heuristic value of the concept of the protonarrative

Analysis of the outer retinal bands in ABCA4 and PRPH2-associated retinopathy using OCT

Purpose: To evaluate the outer retinal bands using OCT in ABCA4- and PRPH2-associated retinopathy and develop a novel imaging biomarker to differentiate between these 2 genotypes. Design: Multicenter case-control study. Participants: Patients with a clinical and genetic diagnosis of ABCA4- or PRPH2-associated retinopathy and an age-matched control group. Methods: Macular OCT was used to measure the thickness of the outer retinal bands 2 and 4 by 2 independent examiners at 4 retinal loci. Main Outcome Measures: Outcome measures included the thicknesses of band 2, band 4, and the band 2/band 4 ratio. Linear mixed modeling was used to make comparisons across the 3 groups. Receiver operating characteristic (ROC) analysis determined the optimal cutoff for the band 2/band 4 ratio to distinguish PRPH2- from ABCA4-associated retinopathy. Results: We included 45 patients with ABCA4 variants, 45 patients with PRPH2 variants, and 45 healthy controls. Band 2 was significantly thicker in patients with PRPH2 compared with ABCA4 (21.4 vs. 15.9 m, P \u3c 0.001) variants, whereas band 4 was thicker in patients with ABCA4 variants than those with PRPH2 variants (27.5 vs. 21.7 m, P \u3c 0.001). Similarly, the band 2/band 4 ratio was significantly different (1.0 vs. 0.6 for PRPH2 vs. ABCA4, P \u3c 0.001). The area under the ROC curve was 0.87 for either band 2 ( \u3e 18.58 m) or band 4 ( \u3c 26.17 μm) alone and 0.99 (95% confidence interval: 0.97–0.99) for the band 2/band 4 ratio with a cutoff threshold of 0.79, providing 100% specificity. Conclusions: We report an altered outer retinal band profile whereby the band 2/band 4 ratio was able to discriminate between PRPH2- and ABCA4-associated retinopathy. This may have future clinic utility in predicting the genotype and provide further insight into the anatomic correlate of band 2. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article

Sibling concordance in symptom onset and atrophy growth rates in Stargardt disease using ultra-widefield fundus autofluorescence

Purpose: To investigate concordance in symptom onset, area of dark autofluorescence (DAF), and growth rate (GR) between Stargardt disease siblings at an age-matched time point. Methods: In this retrospective longitudinal study of sibling pairs with identical biallelic ABCA4 variants, age at symptom onset, best-corrected visual acuity, atrophy area, and effective radius of DAF on ultra-widefield fundus autofluorescence were recorded. Absolute intersibling differences for both eyes were compared with absolute interocular differences using the Mann-Whitney test. Results: Overall 39 patients from 19 families were recruited. In 16 families, age-matched best-corrected visual acuity and DAF were compared between siblings. In 8 families, DAF GR was compared. The median (range) absolute difference in age at symptom onset between siblings was 3 (0-35) years. Absolute intersibling differences in age-matched best-corrected visual acuity were greater than interocular differences (P = 0.01). Similarly, absolute intersibling differences in DAF area and radius were greater than interocular differences (P = 0.04 for area and P = 0.001 for radius). Differences between absolute interocular and intersibling GR were not statistically significant (P = 0.44 for area GR and P = 0.61 for radius GR). Conclusion: There was significant discordance in age-matched best-corrected visual acuity and DAF beyond the expected limits of interocular asymmetry. Lack of significant intersibling differences in GR warrants further investigation