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Association of Reticular Pseudodrusen and Early Onset Drusen  [PDF]
Flore De Bats,Benjamin Wolff,Martine Mauget-Fa?sse,Isabelle Meunier,Philippe Denis,Laurent Kodjikian
ISRN Ophthalmology , 2013, DOI: 10.1155/2013/273085
Abstract: Purpose. To report an association between reticular pseudodrusen, located above the retinal pigment epithelium (RPE), and Early Onset Drusen (EOD) as described using Spectral-Domain Optical Coherence Tomography (SD-OCT). Methods. Eight patients (16 eyes) with EOD were examined. EOD were classified into three entities called Large Colloid Drusen (LCD), Malattia Leventinese (ML), and Cuticular Drusen (CD). Best-corrected visual acuity, fundus examination, color fundus photographs, fundus autofluorescence (FAF), fluorescein angiography (FA), indocyanine green angiography (ICGA), and SD-OCT were performed in all study patients. Results. Four patients had LCD, 2 had ML, and 2 had CD. Reticular pseudodrusen were observed with SD-OCT in all study patients; all these patients had hyperreflective lesions above and below the RPE. Conclusion. Early Onset Drusen appear to be associated with reticular pseudodrusen. SD-OCT is helpful in distinguishing the location of the deposits that are above and below the RPE in EOD. Further studies are needed to understand the role of reticular pseudodrusen in the pathophysiology of EOD. 1. Introduction “Soft drusen” are defined as deposits located between the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch’s membrane [1]. These lesions usually appear after the age of 50 and are usually associated with AMD [2]. Younger people can have similar deposits called “Early Onset Drusen” (EOD). These lesions have been recently classified into three entities called Large Colloid Drusen (LCD), Malattia Leventinese (ML), and Cuticular Drusen (CD) [3]. Recent papers have described the multimodal morphological features of EOD as deposits classically located under the RPE similar to the soft drusen observed in AMD [4–6]. Reticular pseudodrusen, frequently associated with AMD, have been described using SD-OCT. Our purpose was to report a frequent association of reticular pseudodrusen, located above the RPE, and EOD using Spectral-Domain Optical Coherence Tomography (SD-OCT). 2. Patients and Methods Patients with Early Onset Drusen underwent a comprehensive ophthalmologic examination which included best-corrected visual acuity (BCVA), fundus examination, color fundus photographs, multicolor images, fundus autofluorescence (FAF), fluorescein angiography (FA), indocyanine green angiography (ICGA), and Spectral-Domain (Cirrus, Carl Zeiss-Meditec, Dublin, CA, USA; and Spectralis Heidelberg Retinal Angiography OCT, Heidelberg Engineering, Heidelberg, Germany) Optical Coherence Tomography (SD-OCT). Informed consent was
Variation of MODIS reflectance and vegetation indices with viewing geometry and soybean development
Breunig, Fábio M.;Galv?o, Lênio S.;Formaggio, Ant?nio R.;Epiphanio, José C.N.;
Anais da Academia Brasileira de Ciências , 2012, DOI: 10.1590/S0001-37652012005000018
Abstract: directional effects introduce a variability in reflectance and vegetation index determination, especially when large field-of-view sensors are used (e.g., moderate resolution imaging spectroradiometer - modis). in this study, we evaluated directional effects on modis reflectance and four vegetation indices (normalized difference vegetation index - ndvi; enhanced vegetation index - evi; normalized difference water index - ndwi1640 and ndwi2120) with the soybean development in two growing seasons (2004-2005 and 2005-2006). to keep the reproductive stage for a given cultivar as a constant factor while varying viewing geometry, pairs of images obtained in close dates and opposite view angles were analyzed. by using a non-parametric statistics with bootstrapping and by normalizing these indices for angular differences among viewing directions, their sensitivities to directional effects were studied. results showed that the variation in modis reflectance between consecutive phenological stages was generally smaller than that resultant from viewing geometry for closed canopies. the contrary was observed for incomplete canopies. the reflectance of the first seven modis bands was higher in the backscattering. except for the evi, the other vegetation indices had larger values in the forward scattering direction. directional effects decreased with canopy closure. the ndvi was lesser affected by directional effects than the other indices, presenting the smallest differences between viewing directions for fixed phenological stages.
Measurement of Quantum Fluctuations in Geometry  [PDF]
Craig J. Hogan
Physics , 2007, DOI: 10.1103/PhysRevD.77.104031
Abstract: A particular form for the quantum indeterminacy of relative spacetime position of events is derived from the limits of measurement possible with Planck wavelength radiation. The indeterminacy predicts fluctuations from a classically defined geometry in the form of ``holographic noise'' whose spatial character, absolute normalization, and spectrum are predicted with no parameters. The noise has a distinctive transverse spatial shear signature, and a flat power spectral density given by the Planck time. An interferometer signal displays noise due to the uncertainty of relative positions of reflection events. The noise corresponds to an accumulation of phase offset with time that mimics a random walk of those optical elements that change the orientation of a wavefront. It only appears in measurements that compare transverse positions, and does not appear at all in purely radial position measurements. A lower bound on holographic noise follows from a covariant upper bound on gravitational entropy. The predicted holographic noise spectrum is estimated to be comparable to measured noise in the currently operating interferometer GEO600. Because of its transverse character, holographic noise is reduced relative to gravitational wave effects in other interferometer designs, such as LIGO, where beam power is much less in the beamsplitter than in the arms.
STUDY OF MINORITY CARRIER LIFETIME IN SEMICONDUCTORS BY CONTACTLESS MEASUREMENT METHOD:MICROWAVE REFLECTANCE TECHNIQUE
非接触式半导体少子寿命测试方法——微波反射法

Wang Zhengqiu,Gong Haimei,Li Yanjin,Zhou Baoqing,Fang Jiaxiong,
王正秋
,龚海梅

红外与毫米波学报 , 1996,
Abstract: A contactless method of microwave reflectance (MR) measurement for the minority carrier lifetime in semiconductors was introduced and compared with the photoconduction decay (PCD) measurement method.
Optic disc drusen presenting as papilledema: a case report  [PDF]
S Sitaula,M Thapa,AK Sharma
Journal of Chitwan Medical College , 2014, DOI: 10.3126/jcmc.v4i1.10848
Abstract: Optic disc drusens, which are congenital anomalies of optic nerve head, are depositions of mucopolysaccharides and pro-teinaceous material within the optic nerve head. They are usually bilateral and diagnosed incidentally during routine fundus examination where they may be mistaken for papilledema. We report a case of 63 year old female referred to the neuro-ophthalmology department with the clinical suspicion of disc edema. Simple noninvasive investigations like ultrasound B-scan, fundus autofluorescene along with the newer test like spectral domain optical coherence tomography helped us to diagnose it as a case of pseudopapilledema, as optic disc drusen. Thus, a high index of suspicion along with the ancillary tests is helpful in differentiating optic disc drusen from true papilledema. DOI: http://dx.doi.org/10.3126/jcmc.v4i1.10848 Journal of Chitwan Medical College 2014; 4(1): 42-44
In Situ Focused Beam Reflectance Measurement (FBRM), Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and Raman Characterization of the Polymorphic Transformation of Carbamazepine  [PDF]
Yingying Zhao,Ying Bao,Jingkang Wang,Sohrab Rohani
Pharmaceutics , 2012, DOI: 10.3390/pharmaceutics4010164
Abstract: The objective of this work was to study the polymorphic transformation of carbamazepine from Form II to Form III in 1-propanol during seeded isothermal batch crystallization. First, the pure Form II and Form III were obtained and characterized. Then their solubilities and metastable zone limits were measured by in-situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and focused beam reflectance measurement (FBRM). A transition temperature at about 34.2 °C was deduced suggesting the enantiotropic nature of this compound over the studied temperature range. To quantify the polymorph ratio during the transformation process, a new in-situ quantitative method was developed to measure the fraction of Form II by Raman spectroscopy. Successful tracking of the nucleation of the stable form and the transformation from Form II to Form III during isothermal crystallization was achieved by Raman spectroscopy and FBRM. The results from these three in-situ techniques, FBRM, FTIR and Raman were consistent with each other. The results showed a strong dependency on the amount of seeds added during isothermal crystallization.
Abundant Lipid and Protein Components of Drusen  [PDF]
Lan Wang,Mark E. Clark,David K. Crossman,Kyoko Kojima,Jeffrey D. Messinger,James A. Mobley,Christine A. Curcio
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0010329
Abstract: Drusen are extracellular lesions characteristic of aging and age-related maculopathy, a major retinal disease of the elderly. We determined the relative proportions of lipids and proteins in drusen capped with retinal pigment epithelium (RPE) and in RPE isolated from non-macular regions of 36 human retinas with grossly normal maculas obtained <6 hr after death.
Rapid and accurate measurement of the specific surface area of snow using infrared reflectance at 1310 and 1550 nm  [PDF]
J.-C. Gallet,F. Domine,C. S. Zender,G. Picard
The Cryosphere Discussions , 2009,
Abstract: Even though the specific surface area (SSA) of snow is a crucial variable to determine the chemical and climatic impact of the snow cover, few data are available on snow SSA because current measurement methods are not simple to use in the field or do not have a sufficient accuracy. We propose here a novel determination method based on the measurement of the hemispherical reflectance of snow in the infrared using the DUFISSS instrument (DUal Frequency Integrating Sphere for Snow SSA measurement). DUFISSS uses 1310 and 1550 nm radiation provided by laser diodes, an integrating sphere 15 cm in diameter, and InGaAs photodiodes. For SSA<60 m2 kg 1, we use the 1310 nm radiation, reflectance is in the range 15 to 50% and the accuracy is 10%. For SSA>60 m2 kg 1, snow is usually of low to very low density (typically 30 to 100 kg m 3) and this produces artifacts caused by the e-folding length of light in snow being too long. We therefore use 1550 nm radiation for SSA>60 m2 kg 1. Reflectance is then in the range 5 to 12%, and the accuracy is 12%. No effect of crystal shape on reflectance was detected. We propose empirical equations to determine SSA from reflectance at both wavelengths, with that for 1310 nm taking into account the snow density. DUFISSS has been tested in the Alps to measure the snow area index (SAI) of the Alpine snowpack in a south facing area at 2100 m elevation. This was done by measuring the SSA, thickness and density of the seven main layers of the snowpack in just 30 min, and a value of 5350 was found, significantly greater than in Arctic and subarctic regions. DUFISSS can now be used to help study issues related to polar and Alpine atmospheric chemistry and climate.
Measurement of influence geometry of floor convector on his performance  [cached]
Gre??ák T.,Kapjor A.,Hu?vár J.
EPJ Web of Conferences , 2013, DOI: 10.1051/epjconf/20134501036
Abstract: The report deals with experimental measurement of influence geometry bath floor convector on his performance in the thermostatic chamber in natural convection. Purpose is to find influence of slope bath of floor convector on his performance.
Measurement of the specific surface area of snow using infrared reflectance in an integrating sphere at 1310 and 1550 nm
J.-C. Gallet,F. Domine,C. S. Zender,G. Picard
The Cryosphere , 2009,
Abstract: Even though the specific surface area (SSA) and the snow area index (SAI) of snow are crucial variables to determine the chemical and climatic impact of the snow cover, few data are available on the subject. We propose here a novel method to measure snow SSA and SAI. It is based on the measurement of the hemispherical infrared reflectance of snow samples using the DUFISSS instrument (DUal Frequency Integrating Sphere for Snow SSA measurement). DUFISSS uses the 1310 or 1550 nm radiation of laser diodes, an integrating sphere 15 cm in diameter, and InGaAs photodiodes. For SSA<60 m2 kg 1, we use the 1310 nm radiation, reflectance is between 15 and 50% and the accuracy of SSA determination is 10%. For SSA>60 m2 kg 1, snow is usually of low density (typically 30 to 100 kg m 3), resulting in insufficient optical depth and 1310 nm radiation reaches the bottom of the sample, causing artifacts. The 1550 nm radiation is therefore used for SSA>60 m2 kg 1. Reflectance is then in the range 5 to 12% and the accuracy on SSA is 12%. We propose empirical equations to determine SSA from reflectance at both wavelengths, with that for 1310 nm taking into account the snow density. DUFISSS has been used to measure the SSA of snow and the SAI of snowpacks in polar and Alpine regions.
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