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https://www.readbyqxmd.com/read/28222374/diuron-causes-sinking-retardation-and-physiochemical-alteration-in-marine-diatoms-thalassiosira-pseudonana-and-skeletonema-marinoi-dohrnii-complex
#1
Mst Ruhina Margia Khanam, Yohei Shimasaki, Md Zahangir Hosain, Koki Mukai, Michito Tsuyama, Xuchun Qiu, Rumana Tasmin, Hiroshi Goto, Yuji Oshima
The present research investigated the effect of diuron on sinking rate and the physiochemical changes in two marine diatoms, Thalassiosira pseudonana (single-celled species) and Skeletonema marinoi-dohrnii complex (chain-forming species). The results revealed that the sinking rate of both diatoms exposed to diuron at a level of 50% effective concentration for growth (EC50) decreased significantly compared with the control. Photosynthetic performance (Fv/Fm and PIABS) of both diatoms also decreased significantly with diuron exposure...
February 10, 2017: Chemosphere
https://www.readbyqxmd.com/read/28221733/regional-lung-ventilation-pattern-in-preschool-children-with-bronchopulmonary-dysplasia-is-modified-by-bronchodilator-response
#2
Wojciech Durlak, Małgorzata Klimek, Przemko Kwinta
BACKGROUND: Bronchopulmonary dysplasia (BPD) remains a significant long-term complication of prematurity. A standardized method of pulmonary function testing is still not available in preschool children with BPD. We investigated the feasibility of Electrical Impedance Segmentography (EIS) monitoring in this group and the impact of bronchodilator response (BDR) to salbutamol on the pattern of lung ventilation. METHODS: We conducted a follow-up study of 4-year-old premature children who had been treated in the tertiary NICU...
March 2017: Pediatric Pulmonology
https://www.readbyqxmd.com/read/28216688/computed-tomographic-measurement-of-canine-urine-concentration
#3
Allison L Zwingenberger, Danielle D Carrade Holt
Computed tomography (CT) is able to measure the attenuation of urine in Hounsfield units (HU) on abdominal imaging studies. This study was designed to measure the correlation of urine attenuation with urine specific gravity in urine samples of 40 dogs, providing a noninvasive measure of urine concentration. The HU of urine explained 72% of the variance in measured urine specific gravity [R(2) = 0.72, F(1,38) = 95.55, P < 0.001]. This noninvasive measurement can be used to estimate urine concentration in dogs undergoing abdominal CT imaging...
February 2017: Canadian Veterinary Journal. la Revue Vétérinaire Canadienne
https://www.readbyqxmd.com/read/28214845/simulated-microgravity-promotes-angiogenesis-through-rhoa-dependent-rearrangement-of-the-actin-cytoskeleton
#4
Fei Shi, Yong-Chun Wang, Ze-Bing Hu, Hong-Yu Xu, Jing Sun, Yuan Gao, Xiao-Tao Li, Chang-Bin Yang, Chao Xie, Cheng-Fei Li, Shu Zhang, Jiang-Dong Zhao, Xin-Sheng Cao, Xi-Qing Sun
BACKGROUND/AIMS: Microgravity leads to hydrodynamic alterations in the cardiovascular system and is associated with increased angiogenesis, an important aspect of endothelial cell behavior to initiate new vessel growth. Given the critical role of Rho GTPase-dependent cytoskeleton rearrangement in cell migration, small GTPase RhoA might play a potential role in microgravity-induced angiogenesis. METHODS: We examined the organization of actin filaments by FITC-conjugated phalloidin staining, as well as the expression and activity of RhoA by quantitative PCR and Western blot, in human umbilical vein endothelial cells (HUVECs) under normal gravity and simulated microgravity...
January 20, 2017: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/28213759/convection-of-a-colloidal-suspension-in-a-hele-shaw-cell
#5
B L Smorodin, I N Cherepanov, S N Ishutov, B I Myznikova
The results of a theoretical study are presented dealing with convective heat and mass transfer in a colloidal suspension through a Hele-Shaw cell heated from below. The numerical analysis, based on a multi-component model, reveals that for a certain range of parameter values the dynamical regimes of travelling waves as well as oscillatory fingering formation are stable. The bifurcation phenomena and nonlinear evolution of spatiotemporal patterns that develop in the colloid suspension are modeled and discussed, paying special attention to the combined effects of gravity sedimentation, thermal diffusion with positive separation ratio and convection...
February 2017: European Physical Journal. E, Soft Matter
https://www.readbyqxmd.com/read/28212709/erythrocyte-deformability-and-aggregation-responses-to-intermittent-and-continuous-artificial-gravity-exposure
#6
Grau Marijke, Abeln Vera, Vogt Tobias, Bloch Wilhelm, Schneider Stefan
Artificial gravity protocols are used to improve g-tolerance of aviators and discussed as countermeasure during prolonged space flight. Little is known about the impact of artificial gravity on the red blood cells (RBC). The purpose of the study was to test how artificial gravity affects RBC deformability and aggregation, which are important determinants of microcirculation. Nine male subjects were exposed to two hypergravity protocols using a short arm human centrifuge: a continuous (CONT) protocol with constant +2Gz for 30min and an intermittent (INTER) protocol with repeated intervals of +2Gz and rest...
February 2017: Life Sciences in Space Research
https://www.readbyqxmd.com/read/28212219/drug-infusion-systems-technologies-performance-and-pitfalls
#7
Uoo R Kim, Robert A Peterfreund, Mark A Lovich
This review aims to broadly describe drug infusion technologies and raise subtle but important issues arising from infusion therapy that can potentially lead to patient instability and morbidity. Advantages and disadvantages of gravity-dependent drug infusion are described and compared with electromechanical approaches for precise control of medication infusion, including large-volume peristaltic and syringe pumps. This review discusses how drugs and inert carriers interact within infusion systems and outlines several complexities and potential sources of drug error...
February 16, 2017: Anesthesia and Analgesia
https://www.readbyqxmd.com/read/28211734/positivity-of-curvature-squared-corrections-in-gravity
#8
Clifford Cheung, Grant N Remmen
We study the Gauss-Bonnet (GB) term as the leading higher-curvature correction to pure Einstein gravity. Assuming a tree-level ultraviolet completion free of ghosts or tachyons, we prove that the GB term has a nonnegative coefficient in dimensions greater than 4. Our result follows from unitarity of the spectral representation for a general ultraviolet completion of the GB term.
February 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28211720/dynamical-response-near-quantum-critical-points
#9
Andrew Lucas, Snir Gazit, Daniel Podolsky, William Witczak-Krempa
We study high-frequency response functions, notably the optical conductivity, in the vicinity of quantum critical points (QCPs) by allowing for both detuning from the critical coupling and finite temperature. We consider general dimensions and dynamical exponents. This leads to a unified understanding of sum rules. In systems with emergent Lorentz invariance, powerful methods from quantum field theory allow us to fix the high-frequency response in terms of universal coefficients. We test our predictions analytically in the large-N O(N) model and using the gauge-gravity duality and numerically via quantum Monte Carlo simulations on a lattice model hosting the interacting superfluid-insulator QCP...
February 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28211707/relativistic-magnetic-reconnection-in-kerr-spacetime
#10
Felipe A Asenjo, Luca Comisso
The magnetic reconnection process is analyzed for relativistic magnetohydrodynamical plasmas around rotating black holes. A simple generalization of the Sweet-Parker model is used as a first approximation to the problem. The reconnection rate, as well as other important properties of the reconnection layer, has been calculated taking into account the effect of spacetime curvature. Azimuthal and radial current sheet configurations in the equatorial plane of the black hole have been studied, and the case of small black hole rotation rate has been analyzed...
February 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28211459/gravitational-body-forces-focus-north-american-intraplate-earthquakes
#11
Will Levandowski, Mark Zellman, Rich Briggs
Earthquakes far from tectonic plate boundaries generally exploit ancient faults, but not all intraplate faults are equally active. The North American Great Plains exemplify such intraplate earthquake localization, with both natural and induced seismicity generally clustered in discrete zones. Here we use seismic velocity, gravity and topography to generate a 3D lithospheric density model of the region; subsequent finite-element modelling shows that seismicity focuses in regions of high-gravity-derived deviatoric stress...
February 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/28208688/the-impact-of-heat-exposure-and-sleep-restriction-on-firefighters-work-performance-and-physiology-during-simulated-wildfire-suppression
#12
Grace E Vincent, Brad Aisbett, Brianna Larsen, Nicola D Ridgers, Rod Snow, Sally A Ferguson
This study was designed to examine the effects of ambient heat on firefighters' physical task performance, and physiological and perceptual responses when sleep restricted during simulated wildfire conditions. Thirty firefighters were randomly allocated to the sleep restricted (n = 17, SR; 19 °C, 4-h sleep opportunity) or hot and sleep restricted (n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Firefighters performed two days of simulated, intermittent, self-paced work circuits comprising six firefighting tasks...
February 12, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28208391/band-instability-in-near-critical-fluids-subjected-to-vibration-under-weightlessness
#13
T Lyubimova, A Ivantsov, Y Garrabos, C Lecoutre, G Gandikota, D Beysens
Periodical patterns (bands) developing at the interface of two immiscible fluids under vibration parallel to interface are observed under zero-gravity conditions. Fluids are slightly below their liquid-vapor critical point where they behave in a scaled, universal manner. In addition, liquid and vapor densities are close and surface tension is very low. Linear stability analyses and direct numerical simulation show that this instability, although comparable to the frozen wave instability observed in a gravity field, is nonetheless noticeably different when gravity becomes zero...
January 2017: Physical Review. E
https://www.readbyqxmd.com/read/28205656/an-autonomous-lab-on-a-chip-for-space-flight-calibration-of-gravity-induced-transcellular-calcium-polarization-in-single-cell-fern-spores
#14
J Park, M L Salmi, W W A Wan Salim, A Rademacher, B Wickizer, A Schooley, J Benton, A Cantero, P F Argote, M Ren, M Zhang, D M Porterfield, A J Ricco, S J Roux, J L Rickus
This report describes the development of lab-on-a-chip device designed to measure changes in cellular ion gradients that are induced by changes in gravitational (g) forces. The bioCD presented here detects differential calcium ion concentrations outside of individual cells. The device includes sufficient replicates for statistical analysis of the gradients around multiple single cells and around control wells that are empty or include dead cells. In the data presented, the degree of the cellular response correlates with the magnitude of the g-force applied via rotation of the bioCD...
February 16, 2017: Lab on a Chip
https://www.readbyqxmd.com/read/28205642/evaporation-of-inclined-water-droplets
#15
Jin Young Kim, In Gyu Hwang, Byung Mook Weon
When a drop is placed on a flat substrate tilted at an inclined angle, it can be deformed by gravity and its initial contact angle divides into front and rear contact angles by inclination. Here we study on evaporation dynamics of a pure water droplet on a flat solid substrate by controlling substrate inclination and measuring mass and volume changes of an evaporating droplet with time. We find that complete evaporation time of an inclined droplet becomes longer as gravitational influence by inclination becomes stronger...
February 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28203640/tsunami-mitigation-by-resonant-triad-interaction-with-acoustic-gravity-waves
#16
Usama Kadri
Tsunamis have been responsible for the loss of almost a half million lives, widespread long lasting destruction, profound environmental effects, and global financial crisis, within the last two decades. The main tsunami properties that determine the size of impact at the shoreline are its wavelength and amplitude in the ocean. Here, we show that it is in principle possible to reduce the amplitude of a tsunami, and redistribute its energy over a larger space, through forcing it to interact with resonating acoustic-gravity waves...
January 2017: Heliyon
https://www.readbyqxmd.com/read/28202207/catastrophic-varus-collapse-of-the-tibia-in-obese-total-knee-arthroplasty
#17
Thomas K Fehring, Keith A Fehring, Lucas A Anderson, Jesse E Otero, Bryan D Springer
BACKGROUND: Mechanical complications have been underemphasized in reports on total knee arthroplasty (TKA) in obese patients. Noticing an increased prevalence of varus collapse of the tibia in obese total knee patients, we sought to determine if variability in proximal tibial cancellous bone strength played a role in failure. We attempted to define a cancellous threshold above which alternative methods of fixation should be used. METHODS: One thousand one hundred six revision TKAs from 2004-2014 identified 35 patients with varus collapse of the tibia, defined as a change in component position of >10°...
January 30, 2017: Journal of Arthroplasty
https://www.readbyqxmd.com/read/28199884/three-dimensional-growth-of-human-endothelial-cells-in-an-automated-cell-culture-experiment-container-during-the-spacex-crs-8-iss-space-mission-the-spheroids-project
#18
Jessica Pietsch, Samuel Gass, Stefano Nebuloni, David Echegoyen, Stefan Riwaldt, Christin Baake, Johann Bauer, Thomas J Corydon, Marcel Egli, Manfred Infanger, Daniela Grimm
Human endothelial cells (ECs) were sent to the International Space Station (ISS) to determine the impact of microgravity on the formation of three-dimensional structures. For this project, an automatic experiment unit (EU) was designed allowing cell culture in space. In order to enable a safe cell culture, cell nourishment and fixation after a pre-programmed timeframe, the materials used for construction of the EUs were tested in regard to their biocompatibility. These tests revealed a high biocompatibility for all parts of the EUs, which were in contact with the cells or the medium used...
February 7, 2017: Biomaterials
https://www.readbyqxmd.com/read/28196150/a-statistical-model-for-monitoring-shell-disease-in-inshore-lobster-fisheries-a-case-study-in-long-island-sound
#19
Kisei R Tanaka, Samuel L Belknap, Jared J Homola, Yong Chen
The expansion of shell disease is an emerging threat to the inshore lobster fisheries in the northeastern United States. The development of models to improve the efficiency and precision of existing monitoring programs is advocated as an important step in mitigating its harmful effects. The objective of this study is to construct a statistical model that could enhance the existing monitoring effort through (1) identification of potential disease-associated abiotic and biotic factors, and (2) estimation of spatial variation in disease prevalence in the lobster fishery...
2017: PloS One
https://www.readbyqxmd.com/read/28194945/class-type-separation-of-the-polar-and-apolar-components-of-petroleum
#20
William J Robson, Paul A Sutton, Paul McCormack, Neil P Chilcott, Steven J Rowland
Identification of the heteroatom (nitrogen, sulphur, and oxygen)- containing compounds of petroleum is of key importance when considering industrial and environmental issues associated with crude oil production. The more commonly performed methods of crude oil fractionation are often insufficient in the extent to which they separate oils, not allowing defined 'molecular' fractions to be obtained. Methods capable of performing a class type separation are uncommon and are often extensive, and resource and time intensive...
February 8, 2017: Analytical Chemistry
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