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https://www.readbyqxmd.com/read/28107539/towards-cost-effective-operational-monitoring-systems-for-complex-waters-analyzing-small-scale-coastal-processes-with-optical-transmissometry
#1
Marta Ramírez-Pérez, Rafael Gonçalves-Araujo, Sonja Wiegmann, Elena Torrecilla, Raul Bardaji, Rüdiger Röttgers, Astrid Bracher, Jaume Piera
The detection and prediction of changes in coastal ecosystems require a better understanding of the complex physical, chemical and biological interactions, which involves that observations should be performed continuously. For this reason, there is an increasing demand for small, simple and cost-effective in situ sensors to analyze complex coastal waters at a broad range of scales. In this context, this study seeks to explore the potential of beam attenuation spectra, c(λ), measured in situ with an advanced-technology optical transmissometer, for assessing temporal and spatial patterns in the complex estuarine waters of Alfacs Bay (NW Mediterranean) as a test site...
2017: PloS One
https://www.readbyqxmd.com/read/28107493/white-matter-abnormalities-in-two-different-subtypes-of-amnestic-mild-cognitive-impairment
#2
Jianghong Liu, Peipeng Liang, Linlin Yin, Ni Shu, Tengda Zhao, Yi Xing, Fangyu Li, Zhilian Zhao, Kuncheng Li, Ying Han
White matter (WM) degeneration has been found during the course of cognitive decline in both Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI), however, it is unclear whether there are different WM microstructural abnormalities between two subtypes of aMCI, including single domain aMCI (aMCI-s) and multiple domain aMCI (aMCI-m). Thirty-two patients of aMCI single-domain (aMCI-s), twenty-three patients of aMCI multiple-domain (aMCI-m) and twenty-three healthy normal controls (NC) participated in this study...
2017: PloS One
https://www.readbyqxmd.com/read/28106559/abca1-deficiency-affects-basal-cognitive-deficits-and-dendritic-density-in-mice
#3
Nicholas F Fitz, Alexis Y Carter, Victor Tapias, Emilie L Castranio, Ravindra Kodali, Iliya Lefterov, Radosveta Koldamova
ATP-binding cassette transporter A1 (ABCA1) mediates cholesterol efflux to lipid-free apolipoproteins and regulates the generation of high density lipoproteins. Previously, we have shown that lack of Abca1 significantly increases amyloid deposition and cognitive deficits in Alzheimer's disease model mice expressing human amyloid-β protein precursor (APP). The goal of this study was to determine if ABCA1 plays a role in memory deficits caused by amyloid-β (Aβ) oligomers and examine neurite architecture of pyramidal hippocampal neurons...
January 18, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28106118/small-window-parametric-imaging-based-on-information-entropy-for-ultrasound-tissue-characterization
#4
Po-Hsiang Tsui, Chin-Kuo Chen, Wen-Hung Kuo, King-Jen Chang, Jui Fang, Hsiang-Yang Ma, Dean Chou
Constructing ultrasound statistical parametric images by using a sliding window is a widely adopted strategy for characterizing tissues. Deficiency in spatial resolution, the appearance of boundary artifacts, and the prerequisite data distribution limit the practicability of statistical parametric imaging. In this study, small-window entropy parametric imaging was proposed to overcome the above problems. Simulations and measurements of phantoms were executed to acquire backscattered radiofrequency (RF) signals, which were processed to explore the feasibility of small-window entropy imaging in detecting scatterer properties...
January 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28105471/riemannian-statistical-analysis-of-cortical-geometry-with-robustness-to-partial-homology-and-misalignment
#5
Suyash P Awate, Richard M Leahy, Anand A Joshi
Typical studies of the geometry of the cerebral cortical structure focus on either cortical folding or thickness. They rely on spatial normalization, but use cortical descriptors that are sensitive to misregistration arising from the well-known problems of partial homologies between subject brains and local optima in nonlinear registration. In contrast to these approaches, we propose a novel framework for studying the geometry of the entire cortical sheet, subsuming its folding and thickness characteristics...
October 2016: Medical Image Computing and Computer-assisted Intervention: MICCAI ..
https://www.readbyqxmd.com/read/28105469/qin-dawg-validation-of-gradient-nonlinearity-bias-correction-workflow-for-quantitative-diffusion-weighted-imaging-in-multicenter-trials
#6
Dariya I Malyarenko, Lisa J Wilmes, Lori R Arlinghaus, Michael A Jacobs, Wei Huang, Karl G Helmer, Bachir Taouli, Thomas E Yankeelov, David Newitt, Thomas L Chenevert
Previous research has shown that system-dependent gradient nonlinearity (GNL) introduces a significant spatial bias (nonuniformity) in apparent diffusion coefficient (ADC) maps. Here, the feasibility of centralized retrospective system-specific correction of GNL bias for quantitative diffusion-weighted imaging (DWI) in multisite clinical trials is demonstrated across diverse scanners independent of the scanned object. Using corrector maps generated from system characterization by ice-water phantom measurement completed in the previous project phase, GNL bias correction was performed for test ADC measurements from an independent DWI phantom (room temperature agar) at two offset locations in the bore...
December 2016: Tomography: a Journal for Imaging Research
https://www.readbyqxmd.com/read/28104506/assessing-the-risk-of-dengue-virus-transmission-in-a-non-endemic-city-surrounded-by-endemic-and-hyperendemic-areas
#7
Tsz Ho Kwan, Shui Shan Lee, Denise Pui Chung Chan, Manton Cheung, Kai Man Kam
OBJECTIVE: To assess the potential risk of dengue transmission in a non-endemic city using a spatial epidemiological approach METHODS: Past dengue exposure of the general population was examined by dengue virus (DENV) IgG testing of archived samples of voluntary blood donors. Vector intensities were determined by local Ovitrap Index (OI). Analyses were made in context of population statistics at both district and sub-district levels. RESULTS: The overall prevalence of DENV IgG was low at 2...
January 16, 2017: International Journal of Infectious Diseases: IJID
https://www.readbyqxmd.com/read/28103550/estimating-the-accuracy-level-among-individual-detections-in-clustered-microcalcifications
#8
Maria Sainz de Cea, Robert Nishikawa, Yongyi Yang
Computerized detection of clustered microcalcifica tions (MCs) in mammograms often suffers from the occurrence of false positives (FPs), which can vary greatly from case to case. We investigate how to apply statistical estimation to determine the number of FPs that are present in a detected MC lesion. First, we describe the number of true positives (TPs) by a Poisson-Binomial probability distribution, wherein a logistic regression model is trained to determine the probability for an individual detected MC to be a TP based on its detector output...
January 17, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28102157/sexual-dimorphism-of-acetabular-anatomy-based-on-three-dimensional-computed-tomography-image-of-pelvises
#9
Bartosz Musielak, Michał Rychlik, Marek Jóźwiak
BACKGROUND: The study aimed to compare sex differences in the morphology and spatial orientation of pelvic acetabula to advance the understanding of hip anatomy. MATERIAL AND METHODS: The study was based on three-dimensional reconstructions of computed tomography images of 50 female and 50 male acetabula. The images were used for spatial analysis of hip acetabula relative to the base of the sacral bone as the plane of reference. Statistical analysis was performed to compare angles relevant to the actual axis of the acetabulum (inclination angle, anteversion angle, tilt angle) as well as the volume and inner surface area of the acetabulum...
October 28, 2016: Ortopedia, Traumatologia, Rehabilitacja
https://www.readbyqxmd.com/read/28101431/non-invasive-terahertz-imaging-of-tissue-water-content-for-flap-viability-assessment
#10
Neha Bajwa, Joshua Au, Reza Jarrahy, Shijun Sung, Michael C Fishbein, David Riopelle, Daniel B Ennis, Tara Aghaloo, Maie A St John, Warren S Grundfest, Zachary D Taylor
Accurate and early prediction of tissue viability is the most significant determinant of tissue flap survival in reconstructive surgery. Perturbation in tissue water content (TWC) is a generic component of the tissue response to such surgeries, and, therefore, may be an important diagnostic target for assessing the extent of flap viability in vivo. We have previously shown that reflective terahertz (THz) imaging, a non-ionizing technique, can generate spatially resolved maps of TWC in superficial soft tissues, such as cornea and wounds, on the order of minutes...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28101397/statistical-parametric-mapping-of-stimuli-evoked-changes-in-total-blood-flow-velocity-in-the-mouse-cortex-obtained-with-extended-focus-optical-coherence-microscopy
#11
Paul J Marchand, Arno Bouwens, Tristan Bolmont, Vincent K Shamaei, David Nguyen, Daniel Szlag, Jérôme Extermann, Theo Lasser
Functional magnetic resonance (fMRI) imaging is the current gold-standard in neuroimaging. fMRI exploits local changes in blood oxygenation to map neuronal activity over the entire brain. However, its spatial resolution is currently limited to a few hundreds of microns. Here we use extended-focus optical coherence microscopy (xfOCM) to quantitatively measure changes in blood flow velocity during functional hyperaemia at high spatio-temporal resolution in the somatosensory cortex of mice. As optical coherence microscopy acquires hundreds of depth slices simultaneously, blood flow velocity measurements can be performed over several vessels in parallel...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28099997/on-joint-estimation-of-gaussian-graphical-models-for-spatial-and-temporal-data
#12
Zhixiang Lin, Tao Wang, Can Yang, Hongyu Zhao
In this article, we first propose a Bayesian neighborhood selection method to estimate Gaussian Graphical Models (GGMs). We show the graph selection consistency of this method in the sense that the posterior probability of the true model converges to one. When there are multiple groups of data available, instead of estimating the networks independently for each group, joint estimation of the networks may utilize the shared information among groups and lead to improved estimation for each individual network...
January 18, 2017: Biometrics
https://www.readbyqxmd.com/read/28098799/occurrence-of-emerging-micropollutants-in-water-systems-in-gauteng-mpumalanga-and-north-west-provinces-south-africa
#13
Elijah M M Wanda, Hlengilizwe Nyoni, Bhekie B Mamba, Titus A M Msagati
The ubiquitous occurrence of emerging micropollutants (EMPs) in water is an issue of growing environmental-health concern worldwide. However, there remains a paucity of data regarding their levels and occurrence in water. This study determined the occurrence of EMPs namely: carbamazepine (CBZ), galaxolide (HHCB), caffeine (CAF), tonalide (AHTN), 4-nonylphenol (NP), and bisphenol A (BPA) in water from Gauteng, Mpumalanga, and North West provinces, South Africa using comprehensive two-dimensional gas chromatography coupled to high resolution time-of-flight mass spectrometry (GCxGC-HRTOFMS)...
January 13, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28097371/high-resolution-diffusion-weighted-imaging-for-solitary-orbital-tumors-3d-turbo-field-echo-with-diffusion-sensitized-driven-equilibrium-dsde-tfe-preparation-technique
#14
Akio Hiwatashi, Osamu Togao, Koji Yamashita, Kazufumi Kikuchi, Hiroshi Yoshikawa, Makoto Obara, Hiroshi Honda
PURPOSE: To differentiate cystic from solid solitary intraorbital tumors using 3D turbo field echo with diffusion-sensitized driven-equilibrium preparation without contrast material. MATERIALS AND METHODS: This retrospective study was approved by our institutional review boards, and written informed consent was waived. A total of 26 patients with intraorbital tumors were studied. Motion probing gradients were conducted at one direction with b‑values of 0 and 500 s/mm(2)...
January 17, 2017: Clinical Neuroradiology
https://www.readbyqxmd.com/read/28097060/why-choose-random-forest-to-predict-rare-species-distribution-with-few-samples-in-large-undersampled-areas-three-asian-crane-species-models-provide-supporting-evidence
#15
Chunrong Mi, Falk Huettmann, Yumin Guo, Xuesong Han, Lijia Wen
Species distribution models (SDMs) have become an essential tool in ecology, biogeography, evolution and, more recently, in conservation biology. How to generalize species distributions in large undersampled areas, especially with few samples, is a fundamental issue of SDMs. In order to explore this issue, we used the best available presence records for the Hooded Crane (Grus monacha, n = 33), White-naped Crane (Grus vipio, n = 40), and Black-necked Crane (Grus nigricollis, n = 75) in China as three case studies, employing four powerful and commonly used machine learning algorithms to map the breeding distributions of the three species: TreeNet (Stochastic Gradient Boosting, Boosted Regression Tree Model), Random Forest, CART (Classification and Regression Tree) and Maxent (Maximum Entropy Models)...
2017: PeerJ
https://www.readbyqxmd.com/read/28096851/acetylcholinesterase-inhibitor-improves-learning-and-memory-impairment-induced-by-toxoplasma-gondii-infection
#16
Hossein Mahmoudvand, Vahid Sheibani, Hossein Keshavarz, Saeedeh Shojaee, Khadijeh Esmaeelpour, Naser Ziaali
BACKGROUND: Here, we established the mouse models of chronic toxoplasmosis by T. gondii Tehran strain to provide a good understanding about defining the possible association between T. gondii exposure and learning and memory impairments. Moreover, as secondary objective of the present study, we hypothesized whether administration of an acetylcholinesterase (AChE) inhibitor could reduce learning and memory impairments induced by T. gondii infection. METHODS: Twenty-four male BALB/c mice were used to establishment of latent toxoplasmosis...
April 2016: Iranian Journal of Parasitology
https://www.readbyqxmd.com/read/28095725/geospatial-clustering-in-sugar-sweetened-beverage-consumption-among-boston-youth
#17
Kosuke Tamura, Dustin T Duncan, Jessica K Athens, Marie A Bragg, Michael Rienti, Jared Aldstadt, Marc A Scott, Brian Elbel
The objective was to detect geospatial clustering of sugar-sweetened beverage (SSB) intake in Boston adolescents (age = 16.3 ± 1.3 years [range: 13-19]; female = 56.1%; White = 10.4%, Black = 42.6%, Hispanics = 32.4%, and others = 14.6%) using spatial scan statistics. We used data on self-reported SSB intake from the 2008 Boston Youth Survey Geospatial Dataset (n = 1292). Two binary variables were created: consumption of SSB (never versus any) on (1) soda and (2) other sugary drinks (e...
January 17, 2017: International Journal of Food Sciences and Nutrition
https://www.readbyqxmd.com/read/28095199/multiway-array-decomposition-of-eeg-spectrum-implications-of-its-stability-for-the-exploration-of-large-scale-brain-networks
#18
Mareček Radek, Martin Lamoš, René Labounek, Marek Bartoň, Tomáš Slavíček, Michal Mikl, Ivan Rektor, Milan Brázdil
Multiway array decomposition methods have been shown to be promising statistical tools for identifying neural activity in the EEG spectrum. They blindly decompose the EEG spectrum into spatial-temporal-spectral patterns by taking into account inherent relationships among signals acquired at different frequencies and sensors. Our study evaluates the stability of spatial-temporal-spectral patterns derived by one particular method, parallel factor analysis (PARAFAC). We focused on patterns' stability over time and in population and divided the complete data set containing data from 50 healthy subjects into several subsets...
January 17, 2017: Neural Computation
https://www.readbyqxmd.com/read/28092533/linear-system-models-for-ultrasonic-imaging-intensity-signal-statistics
#19
Craig Abbey, Yang Zhu, Sara Bahramian, Michael Insana
Despite a great deal of work characterizing the statistical properties of radio-frequency backscattered ultrasound signals, less is known about the statistical properties of demodulated intensity signals. Analysis of intensity is made more difficult by a strong nonlinearity that arises in the process of demodulation. This limits our ability to characterize the spatial resolution and noise properties of B-mode ultrasound images. In this work, we generalize earlier results on two-point intensity covariance using a multivariate systems approach...
January 16, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28092023/white-matter-alterations-in-college-football-players-a-longitudinal-diffusion-tensor-imaging-study
#20
Michael Christian Mayinger, Kian Merchant-Borna, Jakob Hufschmidt, Marc Muehlmann, Isabelle Ruth Weir, Boris-Stephan Rauchmann, Martha Elizabeth Shenton, Inga Katharina Koerte, Jeffrey John Bazarian
The aim of this study was to evaluate longitudinal changes in the diffusion characteristics of brain white matter (WM) in collegiate athletes at three time points: prior to the start of the football season (T1), after one season of football (T2), followed by six months of no-contact rest (T3). Fifteen male collegiate football players and 5 male non-athlete student controls underwent diffusion MR imaging and computerized cognitive testing at all three timepoints. Whole-brain tract-based spatial statistics (TBSS) were used to compare fractional anisotropy (FA), radial diffusivity (RD), axial diffusivity (AD), and trace between all timepoints...
January 14, 2017: Brain Imaging and Behavior
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