489 research outputs found
Genetic variation of oaks (Quercus spp.) in Switzerland. 3. Lack of impact of postglacial recolonization history on nuclear gene loci
Get PDFQuercus petraea, Quercus pubescens and Quercus robur are closely related and interfertile white oaks native to Switzerland. The three species are known to share identical cpDNA haplotypes, which are indicative of the postglacial. recolonization history of populations. Only two haplotypes are common in Switzerland. We compared variation of cpDNA and of isozymes in 28 oak populations from Switzerland in order to assess the impact of the postglacial population history on current genetic structures of nuclear controlled isozyme gene loci. Species delineation was based on Principal Component Analysis of leaf morphological traits. The species status of populations was reflected at isozyme gene loci, but differentiation between populations with different cpDNA haplotypes and hence different recolonization history was very low at enzyme gene loci for all species. Thus, glacial and postglacial population history was not reflected at nuclear gene loci on the temporal and spatial scale covered by the present study. Extensive gene flow through pollen among populations is likely to have blurred a previously existing genetic differentiation at biparentally inherited gene loci that possibly evolved in the different glacial refugia of the above mentioned cpDNA haplotypes
Uncovering the limits of uniqueness in sampled Gabor phase retrieval: A dense set of counterexamples in L2(ℝ)
No full textSampled Gabor phase retrieval — the problem of recovering a square-integrable signal from the magnitude of its Gabor transform sampled on a lattice — is a fundamental problem in signal processing, with important applications in areas such as imaging and audio processing. Recently, a classification of square-integrable signals which are not phase retrievable from Gabor measurements on parallel lines has been presented. This classification was used to exhibit a family of counterexamples to uniqueness in sampled Gabor phase retrieval. Here, we show that the set of counterexamples to uniqueness in sampled Gabor phase retrieval is dense in L2(ℝ), but is not equal to the whole of L2(ℝ) in general. Overall, our work contributes to a better understanding of the fundamental limits of sampled Gabor phase retrieval.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Analysi
Gabor Frames for Model Sets
No full textWe generalize three main concepts of Gabor analysis for lattices to the setting of model sets: fundamental identity of Gabor analysis, Janssen’s representation of the frame operator and Wexler–Raz biorthogonality relations. Utilizing the connection between model sets and almost periodic functions, as well as Poisson’s summations formula for model sets we develop a form of a bracket product that plays a central role in our approach. Furthermore, we show that, if a Gabor system for a model set admits a dual which is of Gabor type, then the density of the model set has to be greater than one.© The Author(s) 201
A fast learning algorithm for Gabor transformation
Get PDFAn adaptive learning approach for the computation of the coefficients of the generalized nonorthogonal 2-D Gabor transform representation is introduced in this correspondence. The algorithm uses a recursive least squares (RLS) type algorithm. The aim is to achieve minimum mean squared error for the reconstructed image from the set of the Gabor coefficients. The proposed RLS learning offers better accuracy and faster convergence behavior when compared with the least mean squares (LMS)-based algorithms. Applications of this scheme in image data reduction are also demonstrated
Palmprint Identification Using Gabor and Wide Principal Line Features
No full textAbstractIn this paper proposed palmprint identification using Gabor features, Gabor and Wide Principal Line Image (WPLI) features. Extracted a fixed size ROI from palmprint images. Resize the extracted ROI into 64 x 64. Apply the Gabor filters to extract the features from the resized ROI. Dissimilarity distance is used to measure the dissimilarity between the query palmprint and database palmprint images. Experiments were conducted on Polyu Palmprint Database using Gabor features, Gabor and WPLI features. Experimental results shows that the proposed approach using Gabor and WPLI features obtains better results compared with the existing methods
A pilot clinical trial with losartan in Myhre syndrome
No full textIntroduction Myhre syndrome (MS) is an ultra-rare disorder due to pathogenic variants in the SMAD4 gene that encodes a protein regulating the TGF-beta pathway and extra-cellular matrix (ECM) homeostasis. Main clinical features of MS include thickening of skin and joint stiffness. Previous studies showed that losartan improved ECM deposition in MS fibroblasts.Materials and methods Four molecularly confirmed MS subjects (mean age 23.8 +/- 17 years) were evaluated for: (a) skin thickness by Rodnan score, (b) joint range of motion (ROM) by goniometry, and (c) speckle-tracking echocardiogram. Following baseline evaluations, three MS individuals received losartan for 12 months and pre-defined endpoints were monitored after 6 and 12 months of treatment.Results At baseline, Rodnan scores were increased, joint ROM was reduced, and speckle-tracking echocardiogram revealed reduced myocardial strain. In three MS subjects, improvements in skin thickness, joint ROM and to a lesser extent of myocardial strain, were observed after 6 and 12 months of losartan treatment.Conclusions Although further long-term controlled clinical trials with a larger number of affected individuals are needed, the present study suggests that losartan might improve skin, joint and heart abnormalities of MS
Clinical sequencing: is WGS the better WES?
Get PDFCurrent clinical next-generation sequencing is done by using gene panels and exome analysis, both of which involve selective capturing of target regions. However, capturing has limitations in sufficiently covering coding exons, especially GC-rich regions. We compared whole exome sequencing (WES) with the most recent PCR-free whole genome sequencing (WGS), showing that only the latter is able to provide hitherto unprecedented complete coverage of the coding region of the genome. Thus, from a clinical/technical point of view, WGS is the better WES so that capturing is no longer necessary for the most comprehensive genomic testing of Mendelian disorders
The Mind/Body Connection
No full textPhysician and award winning author, Dr Gabor Mate, discusses his research at the intersection of addiction, science, psychology, and compassionhttps://digitalcommons.ciis.edu/publicprograms/1030/thumbnail.jp
Density of Gabor Systems Via the Short Time Fourier Transform
No full textWe apply a new approach to the study of the density of Gabor systems, and obtain a simple and straightforward proof to Ramanathan and Steger’s well-known result regarding the density of Gabor frames and Gabor Riesz sequences. Moreover, this point of view allows us to extend this result in several directions. The approach we use was first observed by Olevskii and the third author in their study of exponential systems, here we develop and simplify it further
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