Outer Retinal Structure in Best Vitelliform Macular Dystrophy

Importance Demonstrating the utility of adaptive optics scanning light ophthalmoscopy (AOSLO) to assess outer retinal structure in Best vitelliform macular dystrophy (BVMD). Objective To characterize outer retinal structure in BVMD using spectral-domain optical coherence tomography (SD-OCT) and AOSLO. Design, Setting, and Participants Prospective, observational case series. Four symptomatic members of a family with BVMD with known BEST1 mutation were recruited at the Advanced Ocular Imaging Program research lab at the Medical College of Wisconsin Eye Institute, Milwaukee. Intervention Thickness of 2 outer retinal layers corresponding to photoreceptor inner and outer segments was measured using SD-OCT. Photoreceptor mosaic AOSLO images within and around visible lesions were obtained, and cone density was assessed in 2 subjects. Main Outcome and Measure Photoreceptor structure. Results Each subject was at a different stage of BVMD, with photoreceptor disruption evident by AOSLO at all stages. When comparing SD-OCT and AOSLO images from the same location, AOSLO images allowed for direct assessment of photoreceptor structure. A variable degree of retained photoreceptors was seen within all lesions. The photoreceptor mosaic immediately adjacent to visible lesions appeared contiguous and was of normal density. Fine hyperreflective structures were visualized by AOSLO, and their anatomical orientation and size were consistent with Henle fibers. Conclusions and Relevance The AOSLO findings indicate that substantial photoreceptor structure persists within active lesions, accounting for good visual acuity in these patients. Despite previous reports of diffuse photoreceptor outer segment abnormalities in BVMD, our data reveal normal photoreceptor structure in areas adjacent to clinical lesions. This study demonstrates the utility of AOSLO for understanding the spectrum of cellular changes that occur in inherited degenerations such as BVMD. Photoreceptors are often significantly affected at various stages of inherited degenerations, and these changes may not be readily apparent with current clinical imaging instrumentation

Effects of the protonophore carbonyl-cyanide m-chlorophenylhydrazone on intracytoplasmic membrane assembly in Rhodobacter sphaeroides

AbstractThe effect of carbonyl-cyanide m-chlorophenyl-hydrazone (CCCP) on intracytoplasmic membrane (ICM) assembly was examined in the purple bacterium Rhodobacter sphaeroides. CCCP blocks generation of the electrochemical proton gradient required for integral membrane protein insertion. ICM formation was induced for 8h, followed by a 4-h exposure to CCCP. Measurements of fluorescence induction/relaxation kinetics showed that CCCP caused a diminished quantum yield, a cessation in expansion of the functional absorption cross-section and a 4- to 10-fold slowing in the electron transfer turnover rate. ICM vesicles (chromatophores) and an upper-pigmented band (UPB) containing ICM growth initiation sites, were isolated and subjected to clear-native electrophoresis. Proteomic analysis of the chromatophore gel bands indicated that CCCP produced a 2.7-fold reduction in spectral counts in the preferentially assembled light-harvesting 2 (LH2) antenna, while the RC-LH1 complex, F1FO-ATPase and pyridine nucleotide transhydrogenase decreased by 1.7–1.9-fold. For 35 soluble enzymes, the ratio of 0.99 for treated/control proteins demonstrated that protein synthesis was unaffected by CCCP, suggesting that the membrane complex decline arose from the turnover of unassembled apoproteins. In the UPB fraction, an ~2-fold accumulation was observed for the preprotein translocase SecY, the SecA translocation ATPase, SecD and SecF insertion components, and chaperonins DnaJ and DnaK, consistent with the possibility that these factors, which act early in the assembly process, have accumulated in association with nascent polypeptides as stabilized assembly intermediates

Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction

With the unprecedented photometric precision of the Kepler Spacecraft, significant systematic and stochastic errors on transit signal levels are observable in the Kepler photometric data. These errors, which include discontinuities, outliers, systematic trends and other instrumental signatures, obscure astrophysical signals. The Presearch Data Conditioning (PDC) module of the Kepler data analysis pipeline tries to remove these errors while preserving planet transits and other astrophysically interesting signals. The completely new noise and stellar variability regime observed in Kepler data poses a significant problem to standard cotrending methods such as SYSREM and TFA. Variable stars are often of particular astrophysical interest so the preservation of their signals is of significant importance to the astrophysical community. We present a Bayesian Maximum A Posteriori (MAP) approach where a subset of highly correlated and quiet stars is used to generate a cotrending basis vector set which is in turn used to establish a range of "reasonable" robust fit parameters. These robust fit parameters are then used to generate a Bayesian Prior and a Bayesian Posterior Probability Distribution Function (PDF) which when maximized finds the best fit that simultaneously removes systematic effects while reducing the signal distortion and noise injection which commonly afflicts simple least-squares (LS) fitting. A numerical and empirical approach is taken where the Bayesian Prior PDFs are generated from fits to the light curve distributions themselves.Comment: 43 pages, 21 figures, Submitted for publication in PASP. Also see companion paper "Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves" by Martin C. Stumpe, et a

Determining Optimum Soil Type and Salinity for Rearing the Federally Endangered Salt Creek Tiger Beetle, \u3ci\u3eCicindela (Ellipsoptera) nevadica lincolniana\u3c/i\u3e Casey (Coleoptera: Carabidae: Cicindelinae)

Effective rearing methods are needed to recover the federally endangered Salt Creek tiger beetle, Cicindela (Ellipsoptera) nevadica lincolniana Casey, a subspecies that occurs exclusively in saline wetlands and seeps along Little Salt Creek in Lancaster County, Nebraska. Experiments were initiated to determine soil type and salinity concentrations appropriate for stimulating female oviposition in laboratory settings to produce larvae and/or adults for reintroduction to native habitats. In 2013, there were highly significant differences between native soil and a sand/loess soil mixture, but no differences between two salinity levels, 0.354 M and 0.5 M. In 2014, using only a sand/loess soil mixture, there were again no differences between the test salinity levels. A sand/loess soil mixture of either 0.354M or 0.5M salinity was determined to be optimum for egg production

Determining Optimum Soil Type and Salinity for Rearing the Federally Endangered Salt Creek Tiger Beetle, \u3ci\u3eCicindela (Ellipsoptera) nevadica lincolniana\u3c/i\u3e Casey (Coleoptera: Carabidae: Cicindelinae)

Effective rearing methods are needed to recover the federally endangered Salt Creek tiger beetle, Cicindela (Ellipsoptera) nevadica lincolniana Casey, a subspecies that occurs exclusively in saline wetlands and seeps along Little Salt Creek in Lancaster County, Nebraska. Experiments were initiated to determine soil type and salinity concentrations appropriate for stimulating female oviposition in laboratory settings to produce larvae and/or adults for reintroduction to native habitats. In 2013, there were highly significant differences between native soil and a sand/loess soil mixture, but no differences between two salinity levels, 0.354 M and 0.5 M. In 2014, using only a sand/loess soil mixture, there were again no differences between the test salinity levels. A sand/loess soil mixture of either 0.354M or 0.5M salinity was determined to be optimum for egg production

Exploring the transcriptional landscape of plant circadian rhythms using genome tiling arrays

BACKGROUND Organisms are able to anticipate changes in the daily environment with an internal oscillator know as the circadian clock. Transcription is an important mechanism in maintaining these oscillations. Here we explore, using whole genome tiling arrays, the extent of rhythmic expression patterns genome-wide, with an unbiased analysis of coding and noncoding regions of the Arabidopsis genome. RESULTS As in previous studies, we detected a circadian rhythm for approximately 25% of the protein coding genes in the genome. With an unbiased interrogation of the genome, extensive rhythmic introns were detected predominantly in phase with adjacent rhythmic exons, creating a transcript that, if translated, would be expected to produce a truncated protein. In some cases, such as the MYB transcription factor AT2G20400, an intron was found to exhibit a circadian rhythm while the remainder of the transcript was otherwise arrhythmic. In addition to several known noncoding transcripts, including microRNA, trans-acting short interfering RNA, and small nucleolar RNA, greater than one thousand intergenic regions were detected as circadian clock regulated, many of which have no predicted function, either coding or noncoding. Nearly 7% of the protein coding genes produced rhythmic antisense transcripts, often for genes whose sense strand was not similarly rhythmic. CONCLUSIONS This study revealed widespread circadian clock regulation of the Arabidopsis genome extending well beyond the protein coding transcripts measured to date. This suggests a greater level of structural and temporal dynamics than previously known

Sources of color variation on firing porcelain

The final color matching of porcelain crowns depends upon the accuracy of the original shade matching by the dentist and variables introduced during processing. Possible sources of processing variables include thickness and color of the opaque, thickness, color, and translucency of the body and enamel layers, firing temperature, and number of firings (Miller, 1987). These processing variables can lead to an error in shade match. The purpose of this study was to quantify, in CIE [Delta]E units: (1) the shade variations when the same batches are fired, (2) the shade variations between different batches, and (3) the differences in color produced by the multiple firing. Three lots of six shades of four commercial brands were included in this study. The color variation of the opaque samples (mean [Delta]E was 0.46) was generally lower than that of the body/opaque samples (mean [Delta]E was 0.86). The average color variation for three different batches of the body/opaque samples was 1.44. The average color difference produced as a result of multiple firings was 1.00 after six firings, compared with the color after three firings.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29247/1/0000304.pd