Read by QxMD icon Read

inverse dynamics

Guan Wang, Junfei Zhao, Cees Haringa, Wenjun Tang, Jianye Xia, Ju Chu, Yingping Zhuang, Siliang Zhang, Amit T Deshmukh, Walter van Gulik, Joseph J Heijnen, Henk J Noorman
In a 54 m3 large-scale penicillin fermentor, the cells experience substrate gradient cycles at the timescales of global mixing time about 20-40 s. Here, we used an intermittent feeding regime (IFR) and a two-compartment reactor (TCR) to mimic these substrate gradients at laboratory-scale continuous cultures. The IFR was applied to simulate substrate dynamics experienced by the cells at full scale at timescales of tens of seconds to minutes (30 s, 3 min and 6 min), while the TCR was designed to simulate substrate gradients at an applied mean residence time (τc) of 6 min...
January 15, 2018: Microbial Biotechnology
Satoshi Inoue, Kanya Kusano, Jörg Büchner, Jan Skála
Solar eruptions are well-known drivers of extreme space weather, which can greatly disturb the Earth's magnetosphere and ionosphere. The triggering process and initial dynamics of these eruptions are still an area of intense study. Here we perform a magnetohydrodynamic simulation taking into account the observed photospheric magnetic field to reveal the dynamics of a solar eruption in a real magnetic environment. In our simulation, we confirmed that tether-cutting reconnection occurring locally above the polarity inversion line creates a twisted flux tube, which is lifted into a toroidal unstable area where it loses equilibrium, destroying the force-free state, and driving the eruption...
January 12, 2018: Nature Communications
Octavio M Palacios-Gimenez, Diogo Milani, Bernardo Lemos, Elio R Castillo, Dardo A Martí, Erica Ramos, Cesar Martins, Diogo C Cabral-de-Mello
BACKGROUND: Neo-sex chromosome systems arose independently multiple times in evolution, presenting the remarkable characteristic of repetitive DNAs accumulation. Among grasshoppers, occurrence of neo-XY was repeatedly noticed in Melanoplinae. Here we analyzed the most abundant tandem repeats of R. bergii (2n = 22, neo-XY♂) using deep Illumina sequencing and graph-based clustering in order to address the neo-sex chromosomes evolution. RESULTS: The analyses revealed ten families of satDNAs comprising about ~1% of the male genome, which occupied mainly C-positive regions of autosomes...
January 8, 2018: BMC Evolutionary Biology
Min Xu, Jin Shen, John C Thomas, Yu Huang, Xinjun Zhu, Luis A Clementi, Jorge R Vega
In particle size measurement with dynamic light scattering (DLS), it is difficult to get an accurate recovery of a bimodal particle size distribution (PSD) with a peak position ratio less than ~2:1, especially when large particles (>350nm) are present. This is due to the inherent noise in the autocorrelation function (ACF) data and the scarce utilization of PSD information during the inversion process. In this paper, the PSD information distribution in the ACF data is investigated. It was found that the initial decay section of the ACF contains more information, especially for a bimodal PSD...
January 8, 2018: Optics Express
Wei-Feng Hsu, Shih-Chih Lin
This paper presents a novel approach to optimizing the design of phase-only computer-generated holograms (CGH) for the creation of binary images in an optical Fourier transform system. Optimization begins by selecting an image pixel with a temporal change in amplitude. The modulated image function undergoes an inverse Fourier transform followed by the imposition of a CGH constraint and the Fourier transform to yield an image function associated with the change in amplitude of the selected pixel. In iterations where the quality of the image is improved, that image function is adopted as the input for the next iteration...
January 1, 2018: Applied Optics
Jian Zhang, Zhaofeng Ding, Cheng Tan, Kevin Huang, Oscar O Bernal, Pei-Chun Ho, Gerald D Morris, Adrian D Hillier, Pabitra K Biswas, Stephen P Cottrell, Hui Xiang, Xin Yao, Douglas E MacLaughlin, Lei Shu
The origin of the pseudogap region below a temperature T* is at the heart of the mysteries of cuprate high-temperature superconductors. Unusual properties of the pseudogap phase, such as broken time-reversal and inversion symmetry are observed in several symmetry-sensitive experiments: polarized neutron diffraction, optical birefringence, dichroic angle-resolved photoemission spectroscopy, second harmonic generation, and polar Kerr effect. These properties suggest that the pseudogap region is a genuine thermodynamic phase and are predicted by theories invoking ordered loop currents or other forms of intra-unit-cell (IUC) magnetic order...
January 2018: Science Advances
Tatsuya Ohtonari, Nobuharu Nishihara, Shinzo Ota, Akio Tanaka
OBJECTIVE: We investigated CSF dynamics at CCJ using Time-SLIP MRI to demonstrate the significance of ventral and dorsal combined CSF dynamics in assessing CSF flow disturbance in patients with CM-I. METHODS: Fifteen examinations were performed in nine cases of CM-I (three females patients; mean age, 24.7 years; age range, 11-46 years) before or after craniocervical decompression. The longitudinal maximum movement of the caudal edge of tagged mid-sagittal CSF at CCJ was measured as a LOM, and total on the ventral and dorsal sides was defined as total LOM...
January 8, 2018: World Neurosurgery
Yeon Soo Kim, Seung Hong Choi, Roh-Eul Yoo, Koung Mi Kang, Tae Jin Yun, Ji-Hoon Kim, Chul-Ho Sohn, Sung-Hye Park, Jae-Kyung Won, Tae Min Kim, Chul-Kee Park, Il Han Kim
To evaluate whether the cerebral blood volume (CBV) measurement with leakage correction from dynamic susceptibility contrast perfusion weighted imaging can be useful in predicting prognosis for primary central nervous system lymphoma (PCNSL). 46 PCNSL patients were included and classified by radiation therapy (RT) stratification into RT (n = 30) and non-RT (n = 16) groups. The corresponding histogram parameters of normalized CBV (nCBV) maps with or without leakage correction were calculated on contrast-enhanced T1 weighted image (CE T1WI) or on fluid attenuated inversion recovery image...
January 11, 2018: Scientific Reports
Xuan Zhang, Xiaofeng Fang, Jiansheng Li, Shunlong Pan, Xiuyun Sun, Jinyou Shen, Weiqing Han, Lianjun Wang, Shuaifei Zhao
Arsenic-contaminated water has significant adverse impacts on human health and ecosystems. We developed a new adsorptive membrane by modifying the porous support layer of a phase inversion formed membrane for arsenic removal. Iron oxide (Fe3O4) microspheres were immobilized in the support layer of the membrane by reverse filtration, followed by dopamine polymerization. The prepared adsorptive membrane was compared with a virgin membrane without Fe3O4 microspheres and a Fe3O4 blended membrane in terms of membrane structures and separation performance...
January 3, 2018: Journal of Colloid and Interface Science
Alex Albaugh, Teresa Head-Gordon, Anders M N Niklasson
Generalized extended Lagrangian Born-Oppenheimer molecular dynamics (XLBOMD) methods provides a framework for fast iteration-free simulations of models that normally require expensive electronic ground state optimizations prior to the force evaluations at every time step. XLBOMD uses dynamically driven auxiliary degrees of freedom that fluctuate about a ground state along with an approximate 'shadow' potential for which an easily obtained, variationally optimized ground state approximates the true reference potential...
January 9, 2018: Journal of Chemical Theory and Computation
Douglas J McCauley, Gabriel Gellner, Neo D Martinez, Richard J Williams, Stuart A Sandin, Fiorenza Micheli, Peter J Mumby, Kevin S McCann
Classically, biomass partitioning across trophic levels was thought to add up to a pyramidal distribution. Numerous exceptions have, however, been noted including complete pyramidal inversions. Elevated levels of biomass top-heaviness (i.e. high consumer/resource biomass ratios) have been reported from Arctic tundra communities to Brazilian phytotelmata, and in species assemblages as diverse as those dominated by sharks and ants. We highlight two major pathways for creating top-heaviness, via: (1) endogenous channels that enhance energy transfer across trophic boundaries within a community and (2) exogenous pathways that transfer energy into communities from across spatial and temporal boundaries...
January 9, 2018: Ecology Letters
Rasmus Fonseca, Dominik Budday, Henry van den Bedem
The function of protein, RNA, and DNA is modulated by fast, dynamic exchanges between three-dimensional conformations. Conformational sampling of biomolecules with exact and nullspace inverse kinematics, using rotatable bonds as revolute joints and noncovalent interactions as holonomic constraints, can accurately characterize these native ensembles. However, sampling biomolecules remains challenging owing to their ultra-high dimensional configuration spaces, and the requirement to avoid (self-) collisions, which results in low acceptance rates...
January 5, 2018: Journal of Computational Chemistry
Kristin Willeford, Justin M Stanek, Todd A McLoda
CONTEXT:   Ankle sprains are one of the most common injuries in the physically active population. Previous researchers have shown that supporting the ankle with taping or bracing is effective in preventing ankle sprains. However, no authors have compared the effects of self-adherent tape and lace-up ankle braces on ankle range of motion (ROM) and dynamic balance in collegiate football players. OBJECTIVE:   To examine the effectiveness of self-adherent tape and lace-up ankle braces in reducing ankle ROM and improving dynamic balance before and after a typical collegiate football practice...
January 9, 2018: Journal of Athletic Training
Zhongwu Li, Yinghua Qiu, Kun Li, Jingjie Sha, Tie Li, Yunfei Chen
Extensive molecular dynamics simulations are employed to optimize nanopore size and surface charge density in order to obtain high ionic selectivity and high water throughput for seawater desalination systems. It is demonstrated that with the help of surface charge exclusion, nanopores with diameter as large as 3.5 nm still have high ionic selectivity. The mechanism of the salt rejection in a surface-charged nanopore is mainly attributed to the ion concentration difference between the cations and anions induced by the surface charges...
January 7, 2018: Journal of Chemical Physics
Axel Fun, Thomas Leitner, Linos Vandekerckhove, Martin Däumer, Alexander Thielen, Bernd Buchholz, Andy I M Hoepelman, Elizabeth H Gisolf, Pauline J Schipper, Annemarie M J Wensing, Monique Nijhuis
BACKGROUND: Emergence of resistance against integrase inhibitor raltegravir in human immunodeficiency virus type 1 (HIV-1) patients is generally associated with selection of one of three signature mutations: Y143C/R, Q148K/H/R or N155H, representing three distinct resistance pathways. The mechanisms that drive selection of a specific pathway are still poorly understood. We investigated the impact of the HIV-1 genetic background and population dynamics on the emergence of raltegravir resistance...
January 5, 2018: Retrovirology
Go Hirabayashi, Yukihiko Ogihara, Shoichi Tsukakoshi, Kiyoshi Daimatsu, Masaaki Inoue, Kiyoyasu Kurahashi, Koichi Maruyama, Tomio Andoh
BACKGROUND: Pressure-controlled inverse inspiratory to expiratory ratio ventilation (PC-IRV) is thought to be beneficial for reducing the dead space volume. OBJECTIVE: To investigate the effects of PC-IRV on the components of dead space during robot-assisted laparoscopic radical prostatectomy (RLRP). DESIGN: A randomised crossover study of three different ventilator modes. SETTING: A single university hospital from September 2014 to April 2015...
January 4, 2018: European Journal of Anaesthesiology
Zhuo Wang, Zhaogang Dong, Hai Zhu, Lei Jin, Ming-Hui Chiu, Lain-Jong Li, Qing-Hua Xu, Goki Eda, Stefan A Maier, Andrew T S Wee, Cheng-Wei Qiu, Joel K W Yang
Monolayer two-dimensional transition metal dichalcogenides (2D TMDCs) exhibit promising characteristics in miniaturized nonlinear optical frequency converters, due to their inversion asymmetry and large second-order nonlinear susceptibility. However, these materials usually have a very short light interaction lengths with the pump laser because they are atomically thin, such that second-harmonic generation (SHG) is generally inefficient. In this paper, we fabricate a judiciously structured 150-nm-thick planar surface consisting of monolayer tungsten diselenide and sub-20-nm-wide gold trenches on flexible substrates, reporting ~7000-fold SHG enhancement without peak broadening or background in the spectra as compared to WSe2 on as-grown sapphire substrates...
January 4, 2018: ACS Nano
Parul Jain, Dipanshu Bansal, Gyaneshwar Sharma, Anupam Bhattacharya, Babita Ingale, Olivier Delaire, Ratnamala Chatterjee
The low temperature magnetic behaviour of the multiferroic quadruple perovskite CaMn7O12 is investigated. The magneto-caloric effect in this material is presented for the first time. Along with the established magnetic transitions, TN1 ~ 90 K and TN2 ~ 45 K, an anomaly at 20 K is observed in our dc magnetization, ac susceptibility and dielectric measurements; below which, an inverse magnetocaloric effect (MCE) is also observed in our -ΔSM (T) plots. The neutron scattering measurements show minimal change between 10 K and 30 K in static correlations, but a clear change in energy and linewidth of the magnetic excitations is evident...
January 4, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Imraan A Faruque, Florian T Muijres, Kenneth M Macfarlane, Andrew Kehlenbeck, J Sean Humbert
This paper presents "optimal identification," a framework for using experimental data to identify the optimality conditions associated with the feedback control law implemented in the measurements. The technique compares closed loop trajectory measurements against a reduced order model of the open loop dynamics, and uses linear matrix inequalities to solve an inverse optimal control problem as a convex optimization that estimates the controller optimality conditions. In this study, the optimal identification technique is applied to two examples, that of a millimeter-scale micro-quadrotor with an engineered controller on board, and the example of a population of freely flying Drosophila hydei maneuvering about forward flight...
January 3, 2018: Biological Cybernetics
Xiaokai Nie, Daniel Coca
The paper introduces a matrix-based approach to estimate the unique one-dimensional discrete-time dynamical system that generated a given sequence of probability density functions whilst subjected to an additive stochastic perturbation with known density.
January 2018: Communications in Nonlinear Science & Numerical Simulation
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"