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https://www.readbyqxmd.com/read/29667885/radiomics-approach-to-prediction-of-occult-mediastinal-lymph-node-metastasis-of-lung-adenocarcinoma
#1
Yan Zhong, Mei Yuan, Teng Zhang, Yu-Dong Zhang, Hai Li, Tong-Fu Yu
OBJECTIVE: The purpose of this study was to evaluate the prognostic impact of radiomic features from CT scans in predicting occult mediastinal lymph node (LN) metastasis of lung adenocarcinoma. MATERIALS AND METHODS: A total of 492 patients with lung adenocarcinoma who underwent preoperative unenhanced chest CT were enrolled in the study. A total of 300 radiomics features quantifying tumor intensity, texture, and wavelet were extracted from the segmented entire-tumor volume of interest of the primary tumor...
April 18, 2018: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/29665147/detrimental-effects-of-a-novel-flow-regime-on-the-functional-trajectory-of-an-aquatic-invertebrate-metacommunity
#2
Albert Ruhi, Xiaoli Dong, Courtney H McDaniel, Darold P Batzer, John L Sabo
Novel flow regimes resulting from dam operations and overallocation of freshwater resources are an emerging consequence of global change. Yet, anticipating how freshwater biodiversity will respond to surging flow regime alteration requires overcoming two challenges in environmental flow science: shifting from local to riverscape-level understanding of biodiversity dynamics, and from static to time-varying characterizations of the flow regime. Here, we used time-series methods (wavelets and multivariate autoregressive models) to quantify flow-regime alteration and to link time-varying flow regimes to the dynamics of multiple local communities potentially connected by dispersal (i...
April 17, 2018: Global Change Biology
https://www.readbyqxmd.com/read/29650316/seesway-a-free-web-based-system-for-analysing-and-exploring-standing-balance-data
#3
Ross A Clark, Yong-Hao Pua
BACKGROUND AND OBJECTIVES: Computerised posturography can be used to assess standing balance, and can predict poor functional outcomes in many clinical populations. A key limitation is the disparate signal filtering and analysis techniques, with many methods requiring custom computer programs. This paper discusses the creation of a freely available web-based software program, SeeSway (www.rehabtools.org/seesway), which was designed to provide powerful tools for pre-processing, analysing and visualising standing balance data in an easy to use and platform independent website...
June 2018: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/29650304/the-design-and-validation-of-a-hybrid-digital-signal-processing-plug-in-for-traditional-cochlear-implant-speech-processors
#4
Fatemeh Hajiaghababa, Hamid R Marateb, Saeed Kermani
BACKGROUND AND OBJECTIVE: Cochlear implants (CIs) are electronic devices restoring partial hearing to deaf individuals with profound hearing loss. In this paper, a new plug-in for traditional IIR filter-banks (FBs) is presented for cochlear implants based on wavelet neural networks (WNNs). Having provided such a plug-in for commercially available CIs, it is possible not only to use available hardware in the market but also to optimize their performance compared with the-state-of-the-art...
June 2018: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/29628883/achieving-accurate-automatic-sleep-staging-on-manually-pre-processed-eeg-data-through-synchronization-feature-extraction-and-graph-metrics
#5
Panteleimon Chriskos, Christos A Frantzidis, Polyxeni T Gkivogkli, Panagiotis D Bamidis, Chrysoula Kourtidou-Papadeli
Sleep staging, the process of assigning labels to epochs of sleep, depending on the stage of sleep they belong, is an arduous, time consuming and error prone process as the initial recordings are quite often polluted by noise from different sources. To properly analyze such data and extract clinical knowledge, noise components must be removed or alleviated. In this paper a pre-processing and subsequent sleep staging pipeline for the sleep analysis of electroencephalographic signals is described. Two novel methods of functional connectivity estimation (Synchronization Likelihood/SL and Relative Wavelet Entropy/RWE) are comparatively investigated for automatic sleep staging through manually pre-processed electroencephalographic recordings...
2018: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/29626837/accurate-interpolation-of-3d-fields-in-charged-particle-optics
#6
Michal Horák, Viktor Badin, Jakub Zlámal
Standard 3D interpolation polynomials often suffer from numerical errors of the calculated field and lack of node points in the 3D solution. We introduce a novel method for accurate and smooth interpolation of arbitrary electromagnetic fields in the vicinity of the optical axis valid up to 90% of the bore radius. Our method combines Fourier analysis and Gaussian wavelet interpolation and provides the axial multipole field functions and their derivatives analytically. The results are accurate and noiseless, usually up to the 5th derivative...
March 29, 2018: Ultramicroscopy
https://www.readbyqxmd.com/read/29626238/primary-central-nervous-system-lymphoma-and-atypical-glioblastoma-differentiation-using-radiomics-approach
#7
Hie Bum Suh, Yoon Seong Choi, Sohi Bae, Sung Soo Ahn, Jong Hee Chang, Seok-Gu Kang, Eui Hyun Kim, Se Hoon Kim, Seung-Koo Lee
OBJECTIVES: To evaluate the diagnostic performance of magnetic resonance (MR) radiomics-based machine-learning algorithms in differentiating primary central nervous system lymphoma (PCNSL) from non-necrotic atypical glioblastoma (GBM). METHODS: Seventy-seven patients (54 individuals with PCNSL and 23 with non-necrotic atypical GBM), diagnosed from January 2009 to April 2017, were enrolled in this retrospective study. A total of 6,366 radiomics features, including shape, volume, first-order, texture, and wavelet-transformed features, were extracted from multi-parametric (post-contrast T1- and T2-weighted, and fluid attenuation inversion recovery images) and multiregional (enhanced and non-enhanced) tumour volumes...
April 6, 2018: European Radiology
https://www.readbyqxmd.com/read/29614430/a-novel-wavelet-sequences-based-on-deep-bidirectional-lstm-network-model-for-ecg-signal-classification
#8
Özal Yildirim
Long-short term memory networks (LSTMs), which have recently emerged in sequential data analysis, are the most widely used type of recurrent neural networks (RNNs) architecture. Progress on the topic of deep learning includes successful adaptations of deep versions of these architectures. In this study, a new model for deep bidirectional LSTM network-based wavelet sequences called DBLSTM-WS was proposed for classifying electrocardiogram (ECG) signals. For this purpose, a new wavelet-based layer is implemented to generate ECG signal sequences...
March 28, 2018: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/29611066/application-of-wavelet-analysis-to-detect-dysfunction-in-cerebral-blood-flow-autoregulation-during-experimental-hyperhomocysteinaemia
#9
Valery V Aleksandrin, Alexander V Ivanov, Edward D Virus, Polina O Bulgakova, Aslan A Kubatiev
The purpose of the present study was to investigate the use of laser Doppler flowmetry (LDF) signals coupled with spectral wavelet analysis to detect endothelial link dysfunction in the autoregulation of cerebral blood flow in the setting of hyperhomocysteinaemia (HHcy). Fifty-one rats were assigned to three groups (intact, control, and HHcy) according to the results of biochemical assays of homocysteine level in blood plasma. LDF signals on the rat brain were recorded by LAKK-02 device to measure the microcirculatory blood flow...
April 3, 2018: Lasers in Medical Science
https://www.readbyqxmd.com/read/29607682/epileptic-seizure-detection-based-on-time-frequency-images-of-eeg-signals-using-gaussian-mixture-model-and-gray-level-co-occurrence-matrix-features
#10
Yang Li, Weigang Cui, Meilin Luo, Ke Li, Lina Wang
The electroencephalogram (EEG) signal analysis is a valuable tool in the evaluation of neurological disorders, which is commonly used for the diagnosis of epileptic seizures. This paper presents a novel automatic EEG signal classification method for epileptic seizure detection. The proposed method first employs a continuous wavelet transform (CWT) method for obtaining the time-frequency images (TFI) of EEG signals. The processed EEG signals are then decomposed into five sub-band frequency components of clinical interest since these sub-band frequency components indicate much better discriminative characteristics...
January 25, 2018: International Journal of Neural Systems
https://www.readbyqxmd.com/read/29603330/a-clinical-decision-support-system-using-ultrasound-textures-and-radiologic-features-to-distinguish-metastasis-from-tumor-free-cervical-lymph-nodes-in-patients-with-papillary-thyroid-carcinoma
#11
Ali Abbasian Ardakani, Reza Reiazi, Afshin Mohammadi
OBJECTIVES: This study investigated the potential of a clinical decision support approach for the classification of metastatic and tumor-free cervical lymph nodes (LNs) in papillary thyroid carcinoma on the basis of radiologic and textural analysis through ultrasound (US) imaging. METHODS: In this research, 170 metastatic and 170 tumor-free LNs were examined by the proposed clinical decision support method. To discover the difference between the groups, US imaging was used for the extraction of radiologic and textural features...
March 30, 2018: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/29601879/thermal-restraint-of-a-bacterial-exopolysaccharide-of-shallow-vent-origin
#12
Maria Teresa Caccamo, Vincenzo Zammuto, Concetta Gugliandolo, Claire Madeleine-Perdrillat, Antonio Spanò, Salvatore Magazù
To dynamically characterize the thermal properties of the fructose-rich exopolysaccharide (EPS1-T14), produced by the marine thermophilic Bacillus licheniformis T14, the Attenuated Total Reflectance Fourier Transform Infra-Red spectroscopy was coupled to variable temperature ranging from ambient to 80 °C. The spectra were analyzed by the following innovative mathematical tools: i) non-ideal spectral deviation, ii) OH-stretching band frequency center shift, iii) spectral distance, and iv) wavelet cross-correlation analysis...
March 27, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29601577/an-open-source-tool-for-automatic-spatiotemporal-assessment-of-calcium-transients-and-local-signal-close-to-noise-activity-in-calcium-imaging-data
#13
Juan Prada, Manju Sasi, Corinna Martin, Sibylle Jablonka, Thomas Dandekar, Robert Blum
Local and spontaneous calcium signals play important roles in neurons and neuronal networks. Spontaneous or cell-autonomous calcium signals may be difficult to assess because they appear in an unpredictable spatiotemporal pattern and in very small neuronal loci of axons or dendrites. We developed an open source bioinformatics tool for an unbiased assessment of calcium signals in x,y-t imaging series. The tool bases its algorithm on a continuous wavelet transform-guided peak detection to identify calcium signal candidates...
March 30, 2018: PLoS Computational Biology
https://www.readbyqxmd.com/read/29600896/wavelet-decomposition-analysis-is-a-clinically-relevant-strategy-to-evaluate-cerebrovascular-buffering-of-blood-pressure-after-spinal-cord-injury
#14
Saqib Saleem, Diana Vucina, Zoe Sarafis, Amanda H X Lee, Jordan W Squair, Otto F Barak, Geoff B Coombs, Tanja Mijacika, Andrei V Krassioukov, Philip N Ainslie, Zeljko Dujic, Yu-Chieh Tzeng, Aaron A Phillips
The capacity of cerebrovasculature to buffer changes in blood pressure (BP) is crucial to prevent stroke, the incidence of which is 3-4 fold elevated after spinal cord injury (SCI). Disruption of descending sympathetic pathways within the spinal cord due to cervical SCI may result in impaired cerebrovascular buffering. Only linear analyses of cerebrovascular buffering of BP, such as transfer function, have been utilized in SCI research. This approach does not account for inherent non-linearity and non-stationarity components of cerebrovascular regulation, often depends on perturbations of BP to increase the statistical power, and does not account for influence of arterial CO2 tension...
March 30, 2018: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/29596496/radiogenomics-analysis-identifies-correlations-of-digital-mammography-with-clinical-molecular-signatures-in-breast-cancer
#15
Jose-Gerardo Tamez-Peña, Juan-Andrés Rodriguez-Rojas, Hugo Gomez-Rueda, Jose-Maria Celaya-Padilla, Roxana-Alicia Rivera-Prieto, Rebeca Palacios-Corona, Margarita Garza-Montemayor, Servando Cardona-Huerta, Victor Treviño
In breast cancer, well-known gene expression subtypes have been related to a specific clinical outcome. However, their impact on the breast tissue phenotype has been poorly studied. Here, we investigate the association of imaging data of tumors to gene expression signatures from 71 patients with breast cancer that underwent pre-treatment digital mammograms and tumor biopsies. From digital mammograms, a semi-automated radiogenomics analysis generated 1,078 features describing the shape, signal distribution, and texture of tumors along their contralateral image used as control...
2018: PloS One
https://www.readbyqxmd.com/read/29593828/electrocardiogram-delineation-in-a-wistar-rat-experimental-model
#16
Pedro David Arini, Sergio Liberczuk, Javier Gustavo Mendieta, Martín Santa María, Guillermo Claudio Bertrán
Background and Objectives: The extensive use of electrocardiogram (ECG) recordings during experimental protocols using small rodents requires an automatic delineation technique in the ECG with high performance. It has been shown that the wavelet transform (WT) based ECG delineator is a suitable tool to delineate electrocardiographic waveforms. The aim of this work is to implement and evaluate the ECG waves delineation in Wistar rats applying WT. We also describe the ECG signal of the Wistar rats giving the characteristics of its spectrum among other useful information...
2018: Computational and Mathematical Methods in Medicine
https://www.readbyqxmd.com/read/29584664/comparison-of-portable-and-bench-top-spectrometers-for-mid-infrared-diffuse-reflectance-measurements-of-soils
#17
Christopher Hutengs, Bernard Ludwig, András Jung, Andreas Eisele, Michael Vohland
Mid-infrared (MIR) spectroscopy has received widespread interest as a method to complement traditional soil analysis. Recently available portable MIR spectrometers additionally offer potential for on-site applications, given sufficient spectral data quality. We therefore tested the performance of the Agilent 4300 Handheld FTIR (DRIFT spectra) in comparison to a Bruker Tensor 27 bench-top instrument in terms of (i) spectral quality and measurement noise quantified by wavelet analysis; (ii) accuracy of partial least squares (PLS) calibrations for soil organic carbon (SOC), total nitrogen (N), pH, clay and sand content with a repeated cross-validation analysis; and (iii) key spectral regions for these soil properties identified with a Monte Carlo spectral variable selection approach...
March 27, 2018: Sensors
https://www.readbyqxmd.com/read/29577781/kurtosis-based-detection-of-intracranial-high-frequency-oscillations-for-the-identification-of-the-seizure-onset-zone
#18
Lucia Rita Quitadamo, Roberto Mai, Francesca Gozzo, Veronica Pelliccia, Francesco Cardinale, Stefano Seri
Pathological High-Frequency Oscillations (HFOs) have been recently proposed as potential biomarker of the seizure onset zone (SOZ) and have shown superior accuracy to interictal epileptiform discharges in delineating its anatomical boundaries. Characterization of HFOs is still in its infancy and this is reflected in the heterogeneity of analysis and reporting methods across studies and in clinical practice. The clinical approach to HFOs identification and quantification usually still relies on visual inspection of EEG data...
January 15, 2018: International Journal of Neural Systems
https://www.readbyqxmd.com/read/29574805/investigation-of-the-relationship-between-electrical-stimulation-frequency-and-muscle-frequency-response-under-submaximal-contractions
#19
Caluê Papcke, Eddy Krueger, Marcia Olandoski, Guilherme Nunes Nogueira-Neto, Percy Nohama, Eduardo Mendonça Scheeren
Neuromuscular electrical stimulation (NMES) is a common tool that is used in clinical and laboratory experiments and can be combined with mechanomyography (MMG) for biofeedback in neuroprostheses. However, it is not clear if the electrical current applied to neuromuscular tissues influences the MMG signal in submaximal contractions. The objective of this study is to investigate whether the electrical stimulation frequency influences the mechanomyographic frequency response of the rectus femoris muscle during submaximal contractions...
March 25, 2018: Artificial Organs
https://www.readbyqxmd.com/read/29573688/coupling-hydrological-modeling-and-support-vector-regression-to-model-hydropeaking-in-alpine-catchments
#20
Gabriele Chiogna, Giorgia Marcolini, Wanying Liu, Teresa Pérez Ciria, Ye Tuo
Water management in the alpine region has an important impact on streamflow. In particular, hydropower production is known to cause hydropeaking i.e., sudden fluctuations in river stage caused by the release or storage of water in artificial reservoirs. Modeling hydropeaking with hydrological models, such as the Soil Water Assessment Tool (SWAT), requires knowledge of reservoir management rules. These data are often not available since they are sensitive information belonging to hydropower production companies...
March 21, 2018: Science of the Total Environment
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