Measurement of retinal blood vessel caliber using two different segmentation methods

In this paper, we explore two different retinal vessel segmentationmethods for the reliable estimation of vessels caliber in retinal images inorder to assess vascular changes as an aid for the diagnosis of the ocularmanifestations of several systemic diseases, namely diabetic retinopathyand hypertensive retinopathy

An automatic graph-based method for retinal blood vessel classification

In this paper, we present an automatic approach to classify retinal vessels intoartery and vein classes by analyzing the extracted graph from the vasculature treeand deciding on the type of intersection points (bifurcation, crossing or meetingpoints). The results obtained by the proposed method were compared withmanual classification on 40 images of the INSPIRE-AVR dataset

Classifier-based cell segmentation from confocal microscopy images

In vivo observation and tracking of cell division in theArabidopsis thaliana root meristem, by time-lapse confocalmicroscopy, is central to biology research. This paper discussesan automatic cell segmentation method, which selectsthe best cell candidates from a starting watershed segmentation.The selection of individual cells is obtained usinga Support Vector Machine (SVM) classifier, based on theshape and edge strength of the cells contour. The result isan improved segmentation, which is largely pruned of badlysegmented cell

Computer-aided diagnosis system for the assessment of retinal vascular changes

This paper presents an automatic application that provides several retinal image analysis functionalities, namely vessel segmentation, vessel width estimation, artery/vein classification and optic disc segmentation. A pipeline of these methods allows the computation of important vessel related indexes, namely the Central Retinal Arteriolar Equivalent (CRAE), Central Retinal Venular Equivalent (CRVE) and Arteriolar-to-Venular Ratio (AVR), as well as various geometrical features associated with vessel bifurcations. The results for AVR estimation were assessed using the images of INSPIRE-AVR dataset; for this dataset, the mean error of the measured AVR values with respect to the reference was identical to the one achieved by a medical expert. The estimation of the CRAE, CRVE and AVR values on 480 images from 120 subjects have shown a significant correlation between right and left eyes and also between images of same eye acquired with different camera fields of view

The Arabidopsis bZIP19 and bZIP23 Activity Requires Zinc Deficiency – Insight on Regulation From Complementation Lines

All living organisms require zinc as an essential micronutrient. Maintaining appropriate intracellular zinc supply, and avoiding deficiency or toxic excess, requires a tight regulation of zinc homeostasis. In Arabidopsis, bZIP19 and bZIP23 (basic-leucine zipper) transcription factors are the central regulators of the zinc deficiency response. Their targets include members of the ZIP (Zrt/Irt-like Protein) transporter family, involved in cellular zinc uptake, which are up-regulated at zinc deficiency. However, the mechanisms by which these transcription factors are regulated by cellular zinc status are not yet known. Here, to further our insight, we took advantage of the zinc deficiency hypersensitive phenotype of the bzip19 bzip23 double mutant, and used it as background to produce complementation lines of each Arabidopsis F-bZIP transcription factor, including bZIP24. On these lines, we performed complementation and localization studies, analyzed the transcript level of a subset of putative target genes, and performed elemental tissue profiling. We find evidence supporting that the zinc-dependent activity of bZIP19 and bZIP23 is modulated by zinc at protein level, in the nucleus, where cellular zinc sufficiency represses their activity and zinc deficiency is required. In addition, we show that these two transcription factors are functionally redundant to a large extent, and that differential tissue-specific expression patterns might, at least partly, explain distinct regulatory activities. Finally, we show that bZIP24 does not play a central role in the Zn deficiency response. Overall, we provide novel information that advances our understanding of the regulatory activity of bZIP19 and bZIP23.</p

Correction of geometrical distortions in bands of chromatography images

This paper presents a methodology for correcting band distortions in Thin-LayerChromatography (TLC) images. After the segmentation of image lanes, theintensity profile of each lane column is spatially aligned with a reference profileusing a modified version of the Correlation Optimized Warping (COW)algorithm. The proposed band correction methodology was assessed using 105profiles of TLC lanes. A set of features for band characterization was extractedfrom each lane profile, before and after band distortion correction, and was usedas input for three distinct one-class classifiers aiming at band identification. In allcases, the best results of band classification were obtained for the set lanes afterband distortion correction

Dimensionamento à flambagem distorcional via MRD de colunas metálicas perfuradas em perfil rack

The present work aims to verify the distorcional curves of the MRD regarding the safety conditions in the design of commercial rack section columns with and without perforations under the action of a centered compression load and the lengths in which the distortional buckling occurs, employing for this purpose computational numerical analyzes via MEF. These sections are widely used in industrial storage systems, known as pallet carriers, and also have drills, which influence the resistance and dimensioning. These holes allow the fitting of the constituent parts of the structure and the achievement of different structural configurations, so that the improvement of the analysis of the columns considering them allows a more precise dimensioning and can generate an even greater reduction of the costs in the manufacture and assembly, Thus increasing the benefits of using these profiles. The first step consists in evaluating the modal behavior of the solid section, in addition to determining the lengths and critical loads of the distortional buckling mode through GBTul. After this phase, the modeling of solid and perforated columns with shell elements in the ANSYS is performed, applying the initial imperfections to perform the non-linear analyzes of elastic-elastic and elastic-plastic buckling, obtaining the ultimate load. Finally, the numerical results obtained in this dissertation are compared with the predictions obtained through the Direct Resistance Method (DSM), which is included in ABNT NBR 14762: 2010 (Annex C), in addition to the proposal of SCHAFER & MOEN (2008,2011), currently present in AISI S100: 2016, and by LANDESMANN et. al (2017).O presente trabalho objetiva a verificação das curvas distorcionais do MRD quanto às condições de segurança no dimensionamento de colunas de seção rack comerciais com e sem perfurações sob a ação de uma carga de compressão centrada e nos comprimentos em que ocorra a flambagem distorcional, empregando para tal análises numéricas computacionais via MEF. Tais seções são amplamente utilizadas em sistemas de estocagem industrial, conhecidas como porta-pallets e, possuem ainda furações, que influenciam na resistência e dimensionamento. Esses furos permitem o encaixe das peças constituintes da estrutura e a obtenção de diferentes configurações estruturais, de forma que o aprimoramento das análises das colunas os considerando permite um dimensionamento mais preciso e pode vir a gerar uma redução ainda maior dos custos na fabricação e montagem, aumentando assim os benefícios da utilização desses perfis. A primeira etapa consiste na avaliação do comportamento modal da seção maciça, além da determinação dos comprimentos e das cargas críticas do modo de flambagem distorcional através do GBTul. Após essa fase é realizada a modelagem das colunas maciças e perfuradas com elementos de casca no ANSYS, aplicando-se as imperfeições iniciais para efetuar as análises não-lineares de pós-flambagem elástica e elasto-plástica, obtendo a carga última. Finalmente, os resultados numéricos obtidos nesta dissertação são comparados com as previsões obtidas através do Método da Resistência Direta (MRD), que consta na ABNT NBR 14762:2010 (Anexo C), além da proposta de SCHAFER & MOEN (2008,2011), presente atualmente na AISI S100:2016, e de LANDESMANN et. al (2017)

A robust anisotropic edge detection method for carotid ultrasound image processing

The conference was held in Belgrade, Serbia, 3-5 September 2018.[Absctract]: A new approach for robust edge detection on B-mode ultrasound images of the carotid artery is proposed in this paper. The proposed method uses anisotropic Gaussian derivative filters along with non-maximum suppression over the overall artery wall orientation in local regions. The anisotropic filters allow using a wider integration scale along the edges while preserving the edge location precision. They also perform edge continuation, resulting in the connection of isolated edge points along linear segments, which is a valuable feature for the segmentation of the artery wall layers. However, this usually results in false edges being detected near convex contours and isolated points. The use of non-maximum suppression over pooled local orientations is proposed to solve this issue. Experimental results are provided to demonstrate that the proposed edge detector outperforms other common methods in the detection of the lumen-intima and media-adventia layer interfaces of the carotid vessel walls. Additionally, the resulting edges are more continuous and precisely located.This work is funded by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and the European Regional Development Fund (ERDF), within the project ”NanoSTIMA: Macro-to-Nano Human Sensing: Towards Integrated Multimodal Health Monitoring and Analytics/NORTE- 01-0145-FEDER-000016”

The Arabidopsis bZIP19 and bZIP23 Activity Requires Zinc Deficiency – Insight on Regulation From Complementation Lines

All living organisms require zinc as an essential micronutrient. Maintaining appropriate intracellular zinc supply, and avoiding deficiency or toxic excess, requires a tight regulation of zinc homeostasis. In Arabidopsis, bZIP19 and bZIP23 (basic-leucine zipper) transcription factors are the central regulators of the zinc deficiency response. Their targets include members of the ZIP (Zrt/Irt-like Protein) transporter family, involved in cellular zinc uptake, which are up-regulated at zinc deficiency. However, the mechanisms by which these transcription factors are regulated by cellular zinc status are not yet known. Here, to further our insight, we took advantage of the zinc deficiency hypersensitive phenotype of the bzip19 bzip23 double mutant, and used it as background to produce complementation lines of each Arabidopsis F-bZIP transcription factor, including bZIP24. On these lines, we performed complementation and localization studies, analyzed the transcript level of a subset of putative target genes, and performed elemental tissue profiling. We find evidence supporting that the zinc-dependent activity of bZIP19 and bZIP23 is modulated by zinc at protein level, in the nucleus, where cellular zinc sufficiency represses their activity and zinc deficiency is required. In addition, we show that these two transcription factors are functionally redundant to a large extent, and that differential tissue-specific expression patterns might, at least partly, explain distinct regulatory activities. Finally, we show that bZIP24 does not play a central role in the Zn deficiency response. Overall, we provide novel information that advances our understanding of the regulatory activity of bZIP19 and bZIP23