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Skew deviation

Kohei Aoki, Yotaro Izumi, Wataru Watanabe, Yuji Shimizu, Hisato Osada, Norinari Honda, Toshihide Itoh, Mitsuo Nakayama
BACKGROUND: While many studies have evaluated the change in lung volume before and after lung resection and correlated this with pulmonary function test results, there is very little evidence on the changes in ventilation perfusion ratio (V/Q) before versus after lung resection. In the present pilot study, we evaluated if V/Q mapping can be constructed using dual energy CT images. METHODS: Thirty-one lung cancer patients planned for pulmonary resection were included in this study...
May 18, 2018: Journal of Cardiothoracic Surgery
Douglas Curran-Everett
Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This thirteenth installment of Explorations in Statistics explores the log transformation, an established technique that rescales the actual observations from an experiment so that the assumptions of some statistical analysis are better met. A general assumption in statistics is that the variability of some response Y is homogeneous across groups or across some predictor variable X. If the variability-the standard deviation-varies in rough proportion to the mean value of Y, a log transformation can equalize the standard deviations...
June 1, 2018: Advances in Physiology Education
Sainan Cheng, Mengjie Fang, Chen Cui, Xiuyu Chen, Gang Yin, Sanjay K Prasad, Di Dong, Jie Tian, Shihua Zhao
OBJECTIVES: To evaluate the prognostic value of texture features based on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) images in hypertrophic cardiomyopathy (HCM) patients with systolic dysfunction. METHODS: 67 HCM patients with systolic dysfunction (41 male and 26 female, mean age ± standard deviation, 46.20 years ± 13.38) were enrolled. All patients underwent 1.5 T CMR cine and LGE imaging. Texture features were extracted from LGE images...
May 4, 2018: European Radiology
Gianna S Monti, Peter Filzmoser, Roland C Deutsch
The guidelines for setting environmental quality standards are increasingly based on probabilistic risk assessment due to a growing general awareness of the need for probabilistic procedures. One of the commonly used tools in probabilistic risk assessment is the species sensitivity distribution (SSD), which represents the proportion of species affected belonging to a biological assemblage as a function of exposure to a specific toxicant. Our focus is on the inverse use of the SSD curve with the aim of estimating the concentration, HCp, of a toxic compound that is hazardous to p% of the biological community under study...
May 3, 2018: Risk Analysis: An Official Publication of the Society for Risk Analysis
Angela Jinsook Oh, Bryan Alexander Lanzman, Yaping Joyce Liao
Purpose: Midline structural defects in the neural axis can give rise to neuro-ophthalmic symptoms. We report a rare case of keyhole aqueduct syndrome presenting after two years of severe cough due to gastroesophageal reflux disease. Observations: A 58-year-old woman with a 2-year history of daily, severe cough presented to the neuro-ophthalmology clinic with progressive diplopia and oscillopsia. Examination revealed a 1-2 Hz down-beating nystagmus in primary gaze that worsened with left, right, and down gazes...
June 2018: American Journal of Ophthalmology Case Reports
Jasmine A Oliver, Omar Zeidan, Sanford L Meeks, Amish P Shah, Jason Pukala, Patrick Kelly, Naren R Ramakrishna, Twyla R Willoughby
PURPOSE: To describe the commissioning of AIRO mobile CT system (AIRO) for adaptive proton therapy on a compact double scattering proton therapy system. METHODS: A Gammex phantom was scanned with varying plug patterns, table heights, and mAs on a CT simulator (CT Sim) and on the AIRO. AIRO-specific CT-stopping power ratio (SPR) curves were created with a commonly used stoichiometric method using the Gammex phantom. A RANDO anthropomorphic thorax, pelvis, and head phantom, and a CIRS thorax and head phantom were scanned on the CT Sim and AIRO...
April 6, 2018: Journal of Applied Clinical Medical Physics
Azuka Ocheli, Anthony Uwaoma Okoro, Ovie Benjamin Ogbe, Godwin Okumagbe Aigbadon
Integrated granulometric and pebble morphometric study of Late Cretaceous rocks of the Benin Flank, Nigeria, were used to delineate depositional process and environment of the rocks in the study area. Granulometric analysis reveals that the sandstones of the Lokoja Bassange Formation have an average graphic mean (Mz) of 0.59Φ (coarse grains), inclusive graphic standard deviation (δi) of 1.36Φ (poorly sorted), graphic kurtosis (Ka) of 1.12Φ (leptokurtic), and inclusive graphic skewness (Ski) of - 0.14Φ (stongly coarse skewed)...
April 17, 2018: Environmental Monitoring and Assessment
Katja N De Paepe, Frederik De Keyzer, Pascal Wolter, Oliver Bechter, Daan Dierickx, Ann Janssens, Gregor Verhoef, Raymond Oyen, Vincent Vandecaveye
BACKGROUND: Correct staging and treatment initiation in malignant lymphoma depends on accurate lymph node characterization. However, nodal assessment based on conventional and diffusion-weighted (DWI) MRI remains challenging, particularly in smaller nodes. PURPOSE: To evaluate first-order apparent diffusion coefficient (ADC) texture parameters compared to mean ADC for lymph node characterization in non-Hodgkin lymphoma (NHL) using whole-body DWI (WB-DWI). STUDY TYPE: Retrospective...
April 14, 2018: Journal of Magnetic Resonance Imaging: JMRI
Robert A Zucker, Raul Gonzalez, Sarah W Feldstein Ewing, Martin P Paulus, Judith Arroyo, Andrew Fuligni, Amanda Sheffield Morris, Mariana Sanchez, Thomas Wills
Neurodevelopmental maturation takes place in a social environment in addition to a neurobiological one. Characterization of social environmental factors that influence this process is therefore an essential component in developing an accurate model of adolescent brain and neurocognitive development, as well as susceptibility to change with the use of marijuana and other drugs. The creation of the Culture and Environment (CE) measurement component of the ABCD protocol was guided by this understanding. Three areas were identified by the CE Work Group as central to this process: influences relating to CE Group membership, influences created by the proximal social environment, influences stemming from social interactions...
March 17, 2018: Developmental Cognitive Neuroscience
Thomas Weymuth, Jonny Proppe, Markus Reiher
Semiclassical dispersion corrections developed by Grimme and coworkers have become indispensable in applications of Kohn--Sham density functional theory. A deeper understanding of the underlying parameterization might be crucial for well-founded further improvements of this successful approach. To this end, we present an in-depth assessment of the fit parameters present in semiclassical (D3-type) dispersion corrections by means of a statistically rigorous analysis. We find that the choice of the cost function generally has a small effect on the empirical parameters of D3-type dispersion corrections with respect to the reference set under consideration...
April 3, 2018: Journal of Chemical Theory and Computation
Hae Young Kim, Young Hoon Kim, Gabin Yun, Won Chang, Yoon Jin Lee, Bohyoung Kim
PURPOSE: To retrospectively investigate whether texture features obtained from preoperative CT images of advanced gastric cancer (AGC) patients could be used for the prediction of occult peritoneal carcinomatosis (PC) detected during operation. MATERIALS AND METHODS: 51 AGC patients with occult PC detected during operation from January 2009 to December 2012 were included as occult PC group. For the control group, other 51 AGC patients without evidence of distant metastasis including PC, and whose clinical T and N stage could be matched to those of the patients of the occult PC group, were selected from the period of January 2011 to July 2012...
2018: PloS One
Sébastien Mulé, Gérard Thiefin, Charlotte Costentin, Carole Durot, Alain Rahmouni, Alain Luciani, Christine Hoeffel
Purpose To determine whether texture features on pretreatment contrast material-enhanced computed tomographic (CT) images can help predict overall survival (OS) and time to progression (TTP) in patients with advanced hepatocellular carcinoma (HCC) treated with sorafenib. Materials and Methods This retrospective study included 92 patients with advanced HCC treated with sorafenib between January 2009 and April 2015 at two independent university hospitals. Sixty-four of the 92 patients (70%) (six women, 58 men; median age, 66 years) were included from institution 1 and constituted a training cohort; 28 patients (30%) (five women, 23 men; median age, 64 years) were included from institution 2 and constituted a validation cohort...
March 27, 2018: Radiology
Khaireddine Ben Mansour, Philippe Gorce, Nasser Rezzoug
The purpose of the current study was to define the impact of regular practice of Nordic walking on the gait of the elderly. Thereby, we aimed to determine whether the gait characteristics of active elderly persons practicing Nordic walking are more similar to healthy adults than that of the sedentary elderly. Comparison was made based on parameters computed from three inertial sensors during walking at a freely chosen velocity. Results showed differences in gait pattern in terms of the amplitude computed from acceleration and angular velocity at the lumbar region (root mean square), the distribution (Skewness) quantified from the vertical and Euclidean norm of the lumbar acceleration, the complexity (Sample Entropy) of the mediolateral component of lumbar angular velocity and the Euclidean norm of the shank acceleration and angular velocity, the regularity of the lower limbs, the spatiotemporal parameters and the variability (standard deviation) of stance and stride durations...
March 27, 2018: Journal of Sports Sciences
Shaun Marshall, Charles Potter, David Medich
A recent analysis of historical radionuclide resuspension datasets confirmed the general applicability of the Anspaugh and modified Anspaugh models of resuspension factors following both controlled and disastrous releases. While observations appear to have larger variance earlier in time, previous studies equally weighted the data for statistical fit calculations; this could induce a positive skewing of resuspension coefficients in the early time-period. A refitting is performed using a relative instrumental weighting of the observations...
May 2018: Health Physics
Elizabeth L Irving, Carolyn M Machan, Sharon Lam, Patricia K Hrynchak, Linda Lillakas
PURPOSE: To investigate mean ocular refraction (MOR) and astigmatism, over the human age range and compare severity of refractive error to earlier studies from clinical populations having large age ranges. METHODS: For this descriptive study patient age, refractive error and history of surgery affecting refraction were abstracted from the Waterloo Eye Study database (WatES). Average MOR, standard deviation of MOR and astigmatism were assessed in relation to age...
March 19, 2018: Journal of Optometry
G Benito, J C Sáez, J B Blázquez, J Quiñones
The most interesting events in Radiological Monitoring Network correspond to higher values of H*(10). The higher doses cause skewness in the probability density function (PDF) of the records, which there are not Gaussian anymore. Within this work the probability of having a dose >2 standard deviations is proposed as surveillance of higher doses. Such probability is estimated by using the Hermite polynomials for reconstructing the PDF. The result is that the probability is ~6 ± 1%, much >2.5% corresponding to Gaussian PDFs, which may be of interest in the design of alarm level for higher doses...
March 15, 2018: Radiation Protection Dosimetry
Ha-Rim Park, Soo-Kyung Cho, Seul Gi Im, Sun-Young Jung, Dalho Kim, Eun Jin Jang, Yoon-Kyoung Sung
Background/Aims: To evaluate the treatment patterns of knee osteoarthritis (OA) patients in South Korea. Methods: Using the Korean nationwide claims database, all knee OA patients in Korea during 2014 were identified by the knee OA diagnostic code (M17) or any OA diagnostic code (M15 to M19) in combination with a procedure for a knee X-ray. Patterns of medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids (CSs), analgesics, and symptomatic slow acting drugs for OA (SYSADOA) were analyzed...
March 21, 2018: Korean Journal of Internal Medicine
Vinit Baliyan, Hamed Kordbacheh, Bimal Parameswaran, Balaji Ganeshan, Dushyant Sahani, Avinash Kambadakone
PURPOSE: To study the impact of keV levels of virtual monoenergetic images generated from rapid kVp-switching dual-energy CT (rsDECT) on CT texture analysis (CTTA). METHODS: This study included 30 consecutive patients (59.3 ± 12 years; range 34-77 years; 17M:13F) who underwent portal venous phase abdominal CT on a rsDECT scanner. Axial 5-mm monoenergetic images at 5 energy levels (40/50/60/70/80 keV) were created and CTTA of liver was performed. CTTA comprised a filtration-histogram technique with different spatial scale filter (SSF) values (0-6)...
March 14, 2018: Abdominal Radiology
S Eh Shirmovsky, D V Shulga
The paper investigates microtubules lattice properties taking into consideration elastic, dipole-dipole interaction of tubulins and viscosity. A microtubule is modeled as a system of bound tubulins, forming a skewed hexagonal two-dimensional lattice. Wave frequencies and group velocities have been calculated. Calculations have been performed for various directions of wave front propagation: helix, along the protofilament, and anti-helix. Three different wave polarization directions have been considered. It has been shown that the direction of the wave polarization influences the frequency and wave group velocity values in the lattice considerably...
April 2018: Bio Systems
Bahram Javidi, Adam Markman, Siddharth Rawat
We investigate the use of compact, lensless, single random phase encoding (SRPE) and double random phase encoding (DRPE) systems for automatic cell identification when multiple cells, either of the same or mixed classes, are in the field of view. A microscope glass slide containing the sample is inputted into the single or double random phase encoding system, which is then illuminated by a coherent or partially coherent light source generating a unique opto-biological signature (OBS) that is captured by an image sensor...
March 1, 2018: Applied Optics
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