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https://www.readbyqxmd.com/read/28738410/no-large-population-of-unbound-or-wide-orbit-jupiter-mass-planets
#1
Przemek Mróz, Andrzej Udalski, Jan Skowron, Radosław Poleski, Szymon Kozłowski, Michał K Szymański, Igor Soszyński, Łukasz Wyrzykowski, Paweł Pietrukowicz, Krzysztof Ulaczyk, Dorota Skowron, Michał Pawlak
Planet formation theories predict that some planets may be ejected from their parent systems as result of dynamical interactions and other processes. Unbound planets can also be formed through gravitational collapse, in a way similar to that in which stars form. A handful of free-floating planetary-mass objects have been discovered by infrared surveys of young stellar clusters and star-forming regions as well as wide-field surveys, but these studies are incomplete for objects below five Jupiter masses. Gravitational microlensing is the only method capable of exploring the entire population of free-floating planets down to Mars-mass objects, because the microlensing signal does not depend on the brightness of the lensing object...
July 24, 2017: Nature
https://www.readbyqxmd.com/read/28735732/assessment-of-mri-issues-for-a-new-cerebral-spinal-fluid-shunt-gravitational-valve-gv
#2
Daniel Moghtader, Hans-Joachim Crawack, Christoph Miethke, Zinah Dörlemann, Frank G Shellock
PURPOSE: A gravitational valve (GV) may be used to treat hydrocephalus, offering possible advantages that include avoidance of over drainage and long-term complications. Because a GV is made from metal, there are potential safety and other problems related to the use of MRI. The objective of this investigation was to evaluate MRI-related issues (i.e., magnetic field interactions, heating, and artifacts) for a newly developed, metallic GV. METHODS: Tests were performed on the GV (GAV 2...
July 20, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28731751/inferences-about-supernova-physics-from-gravitational-wave-measurements-gw151226-spin-misalignment-as-an-indicator-of-strong-black-hole-natal-kicks
#3
Richard O'Shaughnessy, Davide Gerosa, Daniel Wysocki
The inferred parameters of the binary black hole GW151226 are consistent with nonzero spin for the most massive black hole, misaligned from the binary's orbital angular momentum. If the black holes formed through isolated binary evolution from an initially aligned binary star, this misalignment would then arise from a natal kick imparted to the first-born black hole at its birth during stellar collapse. We use simple kinematic arguments to constrain the characteristic magnitude of this kick, and find that a natal kick v_{k}≳50  km/s must be imparted to the black hole at birth to produce misalignments consistent with GW151226...
July 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28731750/coupling-constant-corrections-in-a-holographic-model-of-heavy-ion-collisions
#4
Sašo Grozdanov, Wilke van der Schee
We initiate a holographic study of coupling-dependent heavy ion collisions by analyzing, for the first time, the effects of leading-order, inverse coupling constant corrections. In the dual description, this amounts to colliding gravitational shock waves in a theory with curvature-squared terms. We find that, at intermediate coupling, nuclei experience less stopping and have more energy deposited near the light cone. When the decreased coupling results in an 80% larger shear viscosity, the time at which hydrodynamics becomes a good description of the plasma created from high energy collisions increases by 25%...
July 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28729671/linking-rheology-and-printability-for-dense-and-strong-ceramics-by-direct-ink-writing
#5
Amin M'Barki, Lydéric Bocquet, Adam Stevenson
Direct ink writing of dense and strong ceramic objects remains an important open challenge. We develop a universal dimensionless criterion for printing such objects. Boehmite, an Al2O3 precursor, was used to assess the rheological properties leading to dense structures in ceramics manufactured by direct ink writing. Boehmite suspensions undergo time dependent gelation, thus providing a rheological laboratory of flow behaviours that can be correlated with printability requirements. We measured the evolution of rheological properties over several days and quantified the deformation of simple printed shapes at different aging times...
July 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28729390/walking-economy-is-predictably-determined-by-speed-grade-and-gravitational-load
#6
Lindsay W Ludlow, Peter G Weyand
The metabolic energy human walking requires can vary by more than 10-fold depending on the speed, surface gradient and load carried. Although the mechanical factors determining economy are generally considered to be numerous and complex, we tested a minimum-mechanics hypothesis that only three variables are needed for broad, accurate prediction: speed, surface grade, and total gravitational load. We first measured steady-state rates of oxygen uptake in 20 healthy adult subjects during unloaded treadmill trials from 0...
July 20, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28726830/gravitational-waves-stellar-palaeontology
#7
Ilya Mandel, Alison Farmer
No abstract text is available yet for this article.
July 19, 2017: Nature
https://www.readbyqxmd.com/read/28726829/experimental-signatures-of-the-mixed-axial-gravitational-anomaly-in-the-weyl-semimetal-nbp
#8
Johannes Gooth, Anna C Niemann, Tobias Meng, Adolfo G Grushin, Karl Landsteiner, Bernd Gotsmann, Fabian Menges, Marcus Schmidt, Chandra Shekhar, Vicky Süß, Ruben Hühne, Bernd Rellinghaus, Claudia Felser, Binghai Yan, Kornelius Nielsch
The conservation laws, such as those of charge, energy and momentum, have a central role in physics. In some special cases, classical conservation laws are broken at the quantum level by quantum fluctuations, in which case the theory is said to have quantum anomalies. One of the most prominent examples is the chiral anomaly, which involves massless chiral fermions. These particles have their spin, or internal angular momentum, aligned either parallel or antiparallel with their linear momentum, labelled as left and right chirality, respectively...
July 19, 2017: Nature
https://www.readbyqxmd.com/read/28724575/a-multidirectional-gravity-assist-algorithm-that-enhances-locomotor-control-in-patients-with-stroke-or-spinal-cord-injury
#9
Jean-Baptiste Mignardot, Camille G Le Goff, Rubia van den Brand, Marco Capogrosso, Nicolas Fumeaux, Heike Vallery, Selin Anil, Jessica Lanini, Isabelle Fodor, Grégoire Eberle, Auke Ijspeert, Brigitte Schurch, Armin Curt, Stefano Carda, Jocelyne Bloch, Joachim von Zitzewitz, Grégoire Courtine
Gait recovery after neurological disorders requires remastering the interplay between body mechanics and gravitational forces. Despite the importance of gravity-dependent gait interactions and active participation for promoting this learning, these essential components of gait rehabilitation have received comparatively little attention. To address these issues, we developed an adaptive algorithm that personalizes multidirectional forces applied to the trunk based on patient-specific motor deficits. Implementation of this algorithm in a robotic interface reestablished gait dynamics during highly participative locomotion within a large and safe environment...
July 19, 2017: Science Translational Medicine
https://www.readbyqxmd.com/read/28722158/gravitropism-interferes-with-hydrotropism-via-counteracting-auxin-dynamics-in-cucumber-roots-clinorotation-and-spaceflight-experiments
#10
Keita Morohashi, Miki Okamoto, Chiaki Yamazaki, Nobuharu Fujii, Yutaka Miyazawa, Motoshi Kamada, Haruo Kasahara, Ikuko Osada, Toru Shimazu, Yasuo Fusejima, Akira Higashibata, Takashi Yamazaki, Noriaki Ishioka, Akie Kobayashi, Hideyuki Takahashi
Roots of land plants show gravitropism and hydrotropism in response to gravity and moisture gradients, respectively, for controlling their growth orientation. Gravitropism interferes with hydrotropism, although the mechanistic aspects are poorly understood. Here, we differentiated hydrotropism from gravitropism in cucumber roots by conducting clinorotation and spaceflight experiments. We also compared mechanisms regulating hydrotropism and auxin-regulated gravitropism. Clinorotated or microgravity (μG)-grown cucumber seedling roots hydrotropically bent toward wet substrate in the presence of moisture gradients, but they grew straight in the direction of normal gravitational force at the Earth's surface (1G) on the ground or centrifuge-generated 1G in space...
July 19, 2017: New Phytologist
https://www.readbyqxmd.com/read/28711436/a-simple-method-for-rapid-microbial-identification-from-positive-monomicrobial-blood-culture-bottles-through-matrix-assisted-laser-desorption-ionization-time-of-flight-mass-spectrometry
#11
Jung-Fu Lin, Mao-Cheng Ge, Tsui-Ping Liu, Shih-Cheng Chang, Jang-Jih Lu
BACKGROUND AND PURPOSE: Rapid identification of microbes in the bloodstream is crucial in managing septicemia because of its high disease severity, and direct identification from positive blood culture bottles through matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) can shorten the turnaround time. Therefore, we developed a simple method for rapid microbiological identification from positive blood cultures by using MALDI-TOF MS. METHODS: We modified previously developed methods to propose a faster, simpler and more economical method, which includes centrifugation and hemolysis...
June 30, 2017: Journal of Microbiology, Immunology, and Infection, Wei Mian Yu Gan Ran za Zhi
https://www.readbyqxmd.com/read/28710569/low-shear-modeled-microgravity-grown-penicillium-chrysogenum-mediated-biosynthesis-of-silver-nanoparticles-with-enhanced-antimicrobial-activity-and-its-anticancer-effect-in-human-liver-cancer-and-fibroblast-cells
#12
Sunirmal Sheet, Yesupatham Sathishkumar, Allur Subramaniyam Sivakumar, Kwan Seob Shim, Yang Soo Lee
Gravitational force and shear forces induce various changes in gene expression and metabolite production of microorganisms. Previous reports have shown that there are differences in the expression of different sets of proteins and enzymes under microgravity conditions compared to normal gravity. The aim of this study is to utilize culture filtrates of Penicillium chrysogenum grown under microgravity and normal conditions to synthesize silver nanoparticles and to examine whether there is any difference between their physiochemical and biological function...
July 14, 2017: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/28709228/direct-numerical-simulation-of-an-arbitrarily-shaped-particle-at-a-fluidic-interface
#13
Gregory Lecrivain, Ryoichi Yamamoto, Uwe Hampel, Takashi Taniguchi
A consistent formulation is presented for the direct numerical simulation of an arbitrarily shaped colloidal particle at a deformable fluidic interface. The rigid colloidal particle is decomposed into a collection of solid spherical beads and the three-phase boundaries are replaced with smoothly spreading interfaces. The major merit of the present formulation lies in the ease with which the geometrical decomposition of the colloidal particle is implemented, yet allows the dynamic simulation of intricate three-dimensional colloidal shapes in a binary fluid...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28707940/ultralight-dark-matter-resonates-with-binary-pulsars
#14
Diego Blas, Diana López Nacir, Sergey Sibiryakov
We consider the scenario where dark matter (DM) is represented by an ultralight classical scalar field performing coherent periodic oscillations. We point out that such DM perturbs the dynamics of binary systems either through its gravitational field or via direct coupling to ordinary matter. This perturbation gets resonantly amplified if the frequency of DM oscillations is close to a (half-)integer multiple of the orbital frequency of the system and leads to a secular variation of the orbital period. We suggest using binary pulsars as probes of this scenario and estimate their sensitivity...
June 30, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28704262/effect-of-upper-body-position-on-arterial-stiffness-influence-of-hydrostatic-pressure-and-autonomic-function
#15
Elizabeth C Schroeder, Alexander J Rosenberg, Thessa I M Hilgenkamp, Daniel W White, Tracy Baynard, Bo Fernhall
OBJECTIVE: To evaluate changes in arterial stiffness with positional change and whether the stiffness changes are due to hydrostatic pressure alone or if physiological changes in vasoconstriction of the conduit arteries play a role in the modulation of arterial stiffness. METHODS: Thirty participants' (male = 15, 24 ± 4 years) upper bodies were positioned at 0, 45, and 72° angles. Pulse wave velocity (PWV), cardio-ankle vascular index, carotid beta-stiffness index, carotid blood pressure (cBP), and carotid diameters were measured at each position...
July 12, 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28703213/tricks-to-mute-quantum-noise-aid-hunt-for-gravitational-waves
#16
Elizabeth Gibney
No abstract text is available yet for this article.
July 12, 2017: Nature
https://www.readbyqxmd.com/read/28702971/history-of-venous-leg-ulcers
#17
S Gianfaldoni, U Wollina, J Lotti, R Gianfaldoni, T Lotti, M G Roccia
To retrieve the history of venous ulcers and of skin lesions in general, we must go back to the appearance of human beings on earth. It is interesting to note that cutaneous injuries evolved parallel to human society. An essential first step in the pathogenesis of ulcers was represented by the transition of the quadruped man to Homo Erectus. This condition was characterized by a greater gravitational pressure on the lower limbs, with consequences on the peripheral venous system. Furthermore, human evolution was characterized by an increased risk of traumatic injuries, secondary to his natural need to create fire and hunt (e...
July 13, 2017: Journal of Biological Regulators and Homeostatic Agents
https://www.readbyqxmd.com/read/28701719/dynamic-gene-expression-response-to-altered-gravity-in-human-t-cells
#18
Cora S Thiel, Swantje Hauschild, Andreas Huge, Svantje Tauber, Beatrice A Lauber, Jennifer Polzer, Katrin Paulsen, Hartwin Lier, Frank Engelmann, Burkhard Schmitz, Andreas Schütte, Liliana E Layer, Oliver Ullrich
We investigated the dynamics of immediate and initial gene expression response to different gravitational environments in human Jurkat T lymphocytic cells and compared expression profiles to identify potential gravity-regulated genes and adaptation processes. We used the Affymetrix GeneChip® Human Transcriptome Array 2.0 containing 44,699 protein coding genes and 22,829 non-protein coding genes and performed the experiments during a parabolic flight and a suborbital ballistic rocket mission to cross-validate gravity-regulated gene expression through independent research platforms and different sets of control experiments to exclude other factors than alteration of gravity...
July 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28697483/under-oil-superhydrophilic-wetted-pvdf-electrospun-modified-membrane-for-continuous-gravitational-oil-water-separation-with-outstanding-flux
#19
M Obaid, Hend Omar Mohamed, Ahmed S Yasin, Mohamed A Yassin, Olfat A Fadali, HakYong Kim, Nasser A M Barakat
Water in the world is becoming an increasingly scarce commodity and the membrane technology is a most effective strategy to address this issue. However, the fouling and low flux of the polymeric membrane remains the big challenges. Novel modified Polyvinylidene fluoride (PVDF) membrane was introduced, in this work, using a novel treatment technique for an electrospun polymeric PVDF membrane to be used in oil/water separation systems. The Characterizations of the modified and pristine membranes showed distinct changes in the phase and crystal structure of the membrane material as well as the wettability...
June 28, 2017: Water Research
https://www.readbyqxmd.com/read/28693882/bone-density-and-cross-sectional-geometry-of-the-proximal-femur-are-bilaterally-elevated-in-elite-cricket-fast-bowlers
#20
Matthew J Lees, Clive B Beggs, Matthew J Barlow, Zoe H Rutherford, Kunwar Bansil, Lisa Gannon, Karen Hind
The skeleton of a cricket fast bowler is exposed to a unique combination of gravitational and torsional loading in the form of substantial ground reaction forces delivered through the front landing foot, and anterior-posterior shear forces mediated by regional muscle contractions across the lumbo-pelvic region. The objectives of this study were to compare the hip structural characteristics of elite fast bowlers with recreationally active age-matched controls, and to examine unilateral bone properties in fast bowlers...
July 7, 2017: Journal of Clinical Densitometry
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