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https://www.readbyqxmd.com/read/28441634/spatial-enhancement-of-ecg-using-diagnostic-similarity-score-based-lead-selective-multi-scale-linear-model
#1
Jiss J Nallikuzhy, S Dandapat
In this work, a new patient-specific approach to enhance the spatial resolution of ECG is proposed and evaluated. The proposed model transforms a three-lead ECG into a standard twelve-lead ECG thereby enhancing its spatial resolution. The three leads used for prediction are obtained from the standard twelve-lead ECG. The proposed model takes advantage of the improved inter-lead correlation in wavelet domain. Since the model is patient-specific, it also selects the optimal predictor leads for a given patient using a lead selection algorithm...
April 11, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28440270/refined-genetic-maps-reveal-sexual-dimorphism-in-human-meiotic-recombination-at-multiple-scales
#2
Claude Bhérer, Christopher L Campbell, Adam Auton
In humans, males have lower recombination rates than females over the majority of the genome, but the opposite is usually true near the telomeres. These broad-scale differences have been known for decades, yet little is known about differences at the fine scale. By combining data sets, we have collected recombination events from over 100,000 meioses and have constructed sex-specific genetic maps at a previously unachievable resolution. Here we show that, although a substantial fraction of the genome shows some degree of sexually dimorphic recombination, the vast majority of hotspots are shared between the sexes, with only a small number of putative sex-specific hotspots...
April 25, 2017: Nature Communications
https://www.readbyqxmd.com/read/28436399/identification-of-patients-with-preeclampsia-from-normal-subjects-using-wavelet-based-spectral-analysis-of-heart-rate-variability
#3
A Hossen, A Barhoum, D Jaju, V Gowri, K Al-Hashmi, M O Hassan, L Al-Kharusi
BACKGROUND: The spectral analysis of the heart rate variability (HRV) shows a decrease in the power of the high frequency (HF) component in preeclamptic pregnancy compared with normal pregnancy; such a decrease is associated with an increase in the low frequency (LF) and the very low frequency (VLF) power. The physiological interpretation is that preeclamptic pregnancy is associated with a facilitation of sympathetic regulation and an attenuation of parasympathetic influence of HR compared with non-pregnancy and normal pregnancy...
April 14, 2017: Technology and Health Care: Official Journal of the European Society for Engineering and Medicine
https://www.readbyqxmd.com/read/28432822/focal-liver-lesions-segmentation-and-classification-in-nonenhanced-t2-weighted-mri
#4
Ilias Gatos, Stavros Tsantis, Maria Karamesini, Stavros Spiliopoulos, Dimitris Karnabatidis, John D Hazle, George C Kagadis
PURPOSE: To automatically segment and classify focal liver lesions (FLLs) on nonenhanced T2-weighted magnetic resonance imaging (MRI) scans using a computer-aided diagnosis (CAD) algorithm. METHODS: 71 FLLs (30 benign lesions, 19 hepatocellular carcinomas, and 22 metastases) on T2-weighted MRI scans were delineated by the proposed CAD scheme. The FLL segmentation procedure involved wavelet multiscale analysis to extract accurate edge information and mean intensity values for consecutive edges computed using horizontal and vertical analysis that were fed into the subsequent fuzzy C-means algorithm for final FLL border extraction...
April 22, 2017: Medical Physics
https://www.readbyqxmd.com/read/28432621/comparison-of-air-pollution-in-shanghai-and-lanzhou-based-on-wavelet-transform
#5
Yana Su, Yongzhong Sha, Guangyu Zhai, Shengliang Zong, Jiehua Jia
For a long-period comparative analysis of air pollution in coastal and inland cities, we analyzed the continuous Morlet wavelet transform on the time series of a 5274-day air pollution index in Shanghai and Lanzhou during 15 years and studied the multi-scale variation characteristic, main cycle, and impact factor of the air pollution time series. The analysis showed that (1) air pollution in the two cities was non-stationary and nonlinear, had multiple timescales, and exhibited the characteristics of high in winter and spring and low in summer and autumn...
April 21, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28429754/real-time-detection-of-tsunami-ionospheric-disturbances-with-a-stand-alone-gnss-receiver-a-preliminary-feasibility-demonstration
#6
Giorgio Savastano, Attila Komjathy, Olga Verkhoglyadova, Augusto Mazzoni, Mattia Crespi, Yong Wei, Anthony J Mannucci
It is well known that tsunamis can produce gravity waves that propagate up to the ionosphere generating disturbed electron densities in the E and F regions. These ionospheric disturbances can be studied in detail using ionospheric total electron content (TEC) measurements collected by continuously operating ground-based receivers from the Global Navigation Satellite Systems (GNSS). Here, we present results using a new approach, named VARION (Variometric Approach for Real-Time Ionosphere Observation), and estimate slant TEC (sTEC) variations in a real-time scenario...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28428848/modeling-activity-patterns-of-wildlife-using-time-series-analysis
#7
Jindong Zhang, Vanessa Hull, Zhiyun Ouyang, Liang He, Thomas Connor, Hongbo Yang, Jinyan Huang, Shiqiang Zhou, Zejun Zhang, Caiquan Zhou, Hemin Zhang, Jianguo Liu
The study of wildlife activity patterns is an effective approach to understanding fundamental ecological and evolutionary processes. However, traditional statistical approaches used to conduct quantitative analysis have thus far had limited success in revealing underlying mechanisms driving activity patterns. Here, we combine wavelet analysis, a type of frequency-based time-series analysis, with high-resolution activity data from accelerometers embedded in GPS collars to explore the effects of internal states (e...
April 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28426817/evaluation-of-machine-learning-algorithms-and-structural-features-for-optimal-mri-based-diagnostic-prediction-in-psychosis
#8
Raymond Salvador, Joaquim Radua, Erick J Canales-Rodríguez, Aleix Solanes, Salvador Sarró, José M Goikolea, Alicia Valiente, Gemma C Monté, María Del Carmen Natividad, Amalia Guerrero-Pedraza, Noemí Moro, Paloma Fernández-Corcuera, Benedikt L Amann, Teresa Maristany, Eduard Vieta, Peter J McKenna, Edith Pomarol-Clotet
A relatively large number of studies have investigated the power of structural magnetic resonance imaging (sMRI) data to discriminate patients with schizophrenia from healthy controls. However, very few of them have also included patients with bipolar disorder, allowing the clinically relevant discrimination between both psychotic diagnostics. To assess the efficacy of sMRI data for diagnostic prediction in psychosis we objectively evaluated the discriminative power of a wide range of commonly used machine learning algorithms (ridge, lasso, elastic net and L0 norm regularized logistic regressions, a support vector classifier, regularized discriminant analysis, random forests and a Gaussian process classifier) on main sMRI features including grey and white matter voxel-based morphometry (VBM), vertex-based cortical thickness and volume, region of interest volumetric measures and wavelet-based morphometry (WBM) maps...
2017: PloS One
https://www.readbyqxmd.com/read/28425485/red-light-improves-spermatozoa-motility-and-does-not-induce-oxidative-dna-damage
#9
Daryl Preece, Kay W Chow, Veronica Gomez-Godinez, Kyle Gustafson, Selin Esener, Nicole Ravida, Barbara Durrant, Michael W Berns
The ability to successfully fertilize ova relies upon the swimming ability of spermatozoa. Both in humans and in animals, sperm motility has been used as a metric for the viability of semen samples. Recently, several studies have examined the efficacy of low dosage red light exposure for cellular repair and increasing sperm motility. Of prime importance to the practical application of this technique is the absence of DNA damage caused by radiation exposure. In this study, we examine the effect of 633 nm coherent, red laser light on sperm motility using a novel wavelet-based algorithm that allows for direct measurement of curvilinear velocity under red light illumination...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28421394/waveform-integrity-in-atrial-fibrillation-the-forgotten-issue-of-cardiac-electrophysiology
#10
Miguel Martínez-Iniesta, Juan Ródenas, Raúl Alcaraz, José J Rieta
Atrial fibrillation (AF) is the most common arrhythmia in clinical practice with an increasing prevalence of about 15% in the elderly. Despite other alternatives, catheter ablation is currently considered as the first-line therapy for the treatment of AF. This strategy relies on cardiac electrophysiology systems, which use intracardiac electrograms (EGM) as the basis to determine the cardiac structures contributing to sustain the arrhythmia. However, the noise-free acquisition of these recordings is impossible and they are often contaminated by different perturbations...
April 18, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28413931/glucose-variations-and-activity-are-strongly-coupled-in-sleep-and-wake-in-young-adults-with-type-1-diabetes
#11
Sarah S Farabi, David W Carley, Lauretta Quinn
BACKGROUND: Glucose variations are common throughout sleep and wakefulness in people with type 1 diabetes mellitus (T1DM). The objective of this investigation was to characterize the time-varying coupling between glucose and unstructured physical activity over a 60-hr period in young adults with T1DM. The hypothesis was that coupling would differ during sleep versus wakefulness and would exhibit circadian variations. METHOD: Young adults with T1DM treated with an insulin pump participated in the study...
May 2017: Biological Research for Nursing
https://www.readbyqxmd.com/read/28407564/processing-of-acoustic-signals-via-wavelet-choi-williams-analysis-in-three-point-bending-load-of-carbon-epoxy-and-glass-epoxy-composites
#12
Nima Beheshtizadeh, Amir Mostafapour
In this article, acoustic emission method was used for monitoring of flexural loading of GFRP (Glass fiber/epoxy composite) and CFRP (Carbon fiber/epoxy composite) via one acoustical sensor. In order to signal processing, various methods were employed such as wavelet transform, Short time Fourier transform, Choi - Williams transform and etc. Using two signal processing methods, wavelet transform and Choi - Williams transform, for monitoring of GFRP and CFRP specimens, determines strengths and weaknesses of each method and appointed the best analysis for signal processing of three point bending load of this type of composites...
April 5, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28406916/applications-of-fractional-lower-order-s-transform-time-frequency-filtering-algorithm-to-machine-fault-diagnosis
#13
Junbo Long, Haibin Wang, Daifeng Zha, Peng Li, Huicheng Xie, Lili Mao
Stockwell transform(ST) time-frequency representation(ST-TFR) is a time frequency analysis method which combines short time Fourier transform with wavelet transform, and ST time frequency filtering(ST-TFF) method which takes advantage of time-frequency localized spectra can separate the signals from Gaussian noise. The ST-TFR and ST-TFF methods are used to analyze the fault signals, which is reasonable and effective in general Gaussian noise cases. However, it is proved that the mechanical bearing fault signal belongs to Alpha(α) stable distribution process(1 < α < 2) in this paper, even the noise also is α stable distribution in some special cases...
2017: PloS One
https://www.readbyqxmd.com/read/28393884/novel-wavelet-real-time-analysis-of-neurovascular-coupling-in-neonatal-encephalopathy
#14
Lina F Chalak, Fenghua Tian, Beverley Adams-Huet, Diana Vasil, Abbot Laptook, Takashi Tarumi, Rong Zhang
Birth asphyxia constitutes a major global public health burden for millions of infants, despite hypothermia therapy. There is a critical need for real time surrogate markers of therapeutic success, to aid in patient selection and/or modification of interventions in neonatal encephalopathy (NE). This is a proof of concept study aiming to quantify neurovascular coupling (NVC) using wavelet analysis of the dynamic coherence between amplitude-integrated electroencephalography (aEEG) and near-infrared spectroscopy in NE...
April 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28391823/location-of-mammograms-roi-s-and-reduction-of-false-positive
#15
Luis Antonio Salazar-Licea, Jesús Carlos Pedraza-Ortega, Alberto Pastrana-Palma, Marco A Aceves-Fernandez
BACKGROUND AND OBJECTIVE: There are many work related with segmentation techniques, including nearest neighbor algorithm, fuzzy rules, morphological filters, image entropy, thresholding, machine learning, wavelet analysis, and so on. Such methods carry out the segmentation, but take a lot of processing time by modifying the content of the image or showing discern problems in homogeneous areas, and the segmentation technique is designed to work efficiently only with the techniques used...
May 2017: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/28389269/estimation-of-reproduction-number-and-non-stationary-spectral-analysis-of-dengue-epidemic
#16
Murali Krishna Enduri, Shivakumar Jolad
In this work we analyze the post monsoon Dengue outbreaks by analyzing the transient and long term dynamics of Dengue incidences and its environmental correlates in Ahmedabad city in western India from 2005 to 2012. We calculate the reproduction number Rp using the growth rate of post monsoon Dengue outbreaks and biological parameters like host and vector incubation periods and vector mortality rate, and its uncertainties are estimated through Monte-Carlo simulations by sampling parameters from their respective probability distributions...
April 5, 2017: Mathematical Biosciences
https://www.readbyqxmd.com/read/28387685/investigation-of-heart-rate-variability-of-patients-undergoing-coronary-artery-bypass-grafting-cabg
#17
A Hossen, D Jaju, M Al-Abri, H Al-Sabti, M Mukaddirov, M Hassan, K Al-Hashmi
BACKGROUND: Myocardial revascularization by coronary artery bypass grafting (CABG) is an effective measure for reducing symptoms and mortality in patients with unstable or severe coronary artery disease (CAD). Autonomic function can be estimated non-invasively using heart rate variability (HRV). HRV of patients undergoing CABG is investigated before and after CABG using a soft-decision wavelet based spectral analysis. OBJECTIVE: The main purpose of this work is to evaluate non-invasively HRV in patients undergoing CABG before operation; and to monitor the status of patients through HRV investigation on day 6 and day 30 after the CABG operation...
2017: Technology and Health Care: Official Journal of the European Society for Engineering and Medicine
https://www.readbyqxmd.com/read/28387247/identification-of-the-driving-forces-of-climate-change-using-the-longest-instrumental-temperature-record
#18
Geli Wang, Peicai Yang, Xiuji Zhou
The identification of causal effects is a fundamental problem in climate change research. Here, a new perspective on climate change causality is presented using the central England temperature (CET) dataset, the longest instrumental temperature record, and a combination of slow feature analysis and wavelet analysis. The driving forces of climate change were investigated and the results showed two independent degrees of freedom -a 3.36-year cycle and a 22.6-year cycle, which seem to be connected to the El Niño-Southern Oscillation cycle and the Hale sunspot cycle, respectively...
April 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28386231/bifurcation-in-blood-oscillatory-rhythms-for-patients-with-ischemic-stroke-a-small-scale-clinical-trial-using-laser-doppler-flowmetry-and-computational-modeling-of-vasomotion
#19
Alexey Goltsov, Anastasia V Anisimova, Maria Zakharkina, Alexander I Krupatkin, Viktor V Sidorov, Sergei G Sokolovski, Edik Rafailov
We describe application of spectral analysis of laser Doppler flowmetry (LDF) signals to investigation of cerebrovascular haemodynamics in patients with post-acute ischemic stroke (AIS) and cerebrovascular insufficiency. LDF was performed from 3 to 7 days after the onset of AIS on forehead in the right and left supraorbital regions in patients. Analysis of LDF signals showed that perfusion in the microvasculature in AIS patients was lower than that in patients with cerebrovascular insufficiency. As a result of wavelet analysis of the LDF signals we obtained activation of the vasomotion in the frequency range of myogenic oscillation of 0...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28385192/fault-detection-of-feed-water-treatment-process-using-pca-wd-with-parameter-optimization
#20
Shirong Zhang, Qian Tang, Yu Lin, Yuling Tang
Feed water treatment process (FWTP) is an essential part of utility boilers; and fault detection is expected for its reliability improvement. Classical principal component analysis (PCA) has been applied to FWTPs in our previous work; however, the noises of T(2) and SPE statistics result in false detections and missed detections. In this paper, Wavelet denoise (WD) is combined with PCA to form a new algorithm, (PCA-WD), where WD is intentionally employed to deal with the noises. The parameter selection of PCA-WD is further formulated as an optimization problem; and PSO is employed for optimization solution...
April 3, 2017: ISA Transactions
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