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Structure variation

Tejaswy Pailla, Werner Jiang, Benjamin Dichter, Edward F Chang, Vikash Gilja, Tejaswy Pailla, Werner Jiang, Benjamin Dichter, Edward F Chang, Vikash Gilja, Vikash Gilja, Werner Jiang, Tejaswy Pailla, Benjamin Dichter, Edward F Chang
Brain Computer Interfaces (BCIs) assist individuals with motor disabilities by enabling them to control prosthetic devices with their neural activity. Performance of closed-loop BCI systems can be improved by using design strategies that leverage structured and task-relevant neural activity. We use data from high density electrocorticography (ECoG) grids implanted in three subjects to study sensory-motor activity during an instructed speech task in which the subjects vocalized three cardinal vowel phonemes...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Shiyu Liu, Hao Nan, Nemat Dolatsha, Amin Arbabian, Shiyu Liu, Hao Nan, Nemat Dolatsha, Amin Arbabian, Hao Nan, Nemat Dolatsha, Amin Arbabian, Shiyu Liu
Available data on the dielectric properties of biological tissue across a frequency range adds an extra degree of freedom of contrast besides the baseline structural information obtained by conventional imaging techniques. In this paper, we propose a new methodology to non-invasively extract the normalized effective conductivity of samples over a large frequency range using microwave-induced thermoacoustic (TA) signals. Additionally, a calibration approach has been adopted to remove the frequency dependency of the experimental setup errors as well as the RF power variation...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Oznur Sengel, Olcay Kursun, Oznur Sengel, Olcay Kursun, Olcay Kursun, Oznur Sengel
Clustering is an unsupervised data mining tool and in bioinformatics, clustering genome sequences is used to group related biological sequences when there is no additional supervision. Sequence clusters are often related with gene/protein families, which can shed some light onto determining tertiary structures. To extract such hidden and valuable structures in a data set of genome sequences can benefit from better clustering methods such as the recently popular Spectral Clustering. In this study, we apply spectral clustering and its improved variations to sequence clustering task in our efforts to develop a novel approach for improving it...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Yong Zhang, Tina VanRiper, Brian Rague, Drew Weidman, Yong Zhang, Tina VanRiper, Brian Rague, Drew Weidman, Tina VanRiper, Drew Weidman, Brian Rague, Yong Zhang
In this project, fluid flow and fluid-structure interaction are studied for the human lower gastrointestinal (GI) region. The study consists of two steps. First, we apply meshing methods to discretize both the human lower GI model and the catheter model at sufficient resolution suitable for importing into a Finite Element Analysis (FEA) tool. For model discretization, 3D models of the colon reconstructed from human MRI slices are used to obtain the valid inlet and outlet boundary surfaces. To resolve the viscous boundary layer in flow studies, a special structure of the near-wall volumetric mesh is built by triangular prisms that construct quasi-structured, multiple near-boundary sub-layers...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
George D O'Clock, George D O'Clock, George D O'Clock
Cellular engineering involves modification and control of cell properties, and requires an understanding of fundamentals and mechanisms of action for cellular derived product development. One of the keys to success in cellular engineering involves the quality and validity of results obtained from cell chemical signaling pathway assays. The accuracy of the assay data cannot be verified or assured if the effect of positive feedback, nonlinearities, and interrelationships between cell chemical signaling pathway elements are not understood, modeled, and simulated...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Ameneh Boroomand, Edward Li, Mohammad Javad Shafiee, Masoom A Haider, Farzad Khalvati, Alexander Wong, Ameneh Boroomand, Edward Li, Mohammad Javad Shafiee, Masoom A Haider, Farzad Khalvati, Alexander Wong, Alexander Wong, Mohammad Javad Shafiee, Edward Li, Masoom A Haider, Ameneh Boroomand, Farzad Khalvati
Magnetic resonance (MR) images of higher quality is demanded for helping with more accurate and earlier diagnosis of different diseases. The overall quality of MR images is limited due to the existence of different degradation factors such as (1) MR aberrations due to intrinsic properties of the MR scanner, (2) magnetic field inhomogeneity, and (3) inherent MRI noise. Correcting each MRI degradation factor could be solely useful for the quality enhancement of MR imaging with a limited impact. Here, we propose a unified Bayesian based compensated MR imaging (CMRI) system which jointly corrects for the different aforementioned MR aberrations as well as MR noise and hence generates compensated MR (CMR) images with a higher quality...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Angelica I Aviles, Thomas Widlak, Alicia Casals, Habib Ammari, Angelica I Aviles, Thomas Widlak, Alicia Casals, Habib Ammari, Habib Ammari, Thomas Widlak, Angelica I Aviles, Alicia Casals
Estimation of the cardiac motion is very important in order to detect heart diseases. This work presents a cardiac motion estimation approach using ultrafast ultrasound data. We optimize a variational framework which has the benefits of combining low-rank data representation with topology preservation. We show through the analysis of experimental results that this combination offers a radical reduction in computational time and noise while ensuring preservation of the anatomical structure of the heart under complex deformations...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Ying Li, Jing Qin, Stanley Osher, Wentai Liu, Ying Li, Jing Qin, Stanley Osher, Wentai Liu, Jing Qin, Stanley Osher, Ying Li, Wentai Liu
EEG source imaging is able to reconstruct sources in the brain from scalp measurements with high temporal resolution. Due to the limited number of sensors, it is very challenging to locate the source accurately with high spatial resolution. Recently, several total variation (TV) based methods have been proposed to explore sparsity of the source spatial gradients, which is based on the assumption that the source is constant at each subregion. However, since the sources have more complex structures in practice, these methods have difficulty in recovering the current density variation and locating source peaks...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
José M Gualberto, Kathleen J Newton
The large mitochondrial genomes of angiosperms are unusually dynamic because of recombination activities involving repeated sequences. These activities generate subgenomic forms and extensive genomic variation even within the same species. Such changes in genome structure are responsible for the rapid evolution of plant mitochondrial DNA and for the variants associated with cytoplasmic male sterility and abnormal growth phenotypes. Nuclear genes modulate these processes, and over the past decade, several of these genes have been identified...
February 9, 2017: Annual Review of Plant Biology
Juliana Menger, William E Magnusson, Marti J Anderson, Martin Schlegel, Guy Pe'er, Klaus Henle
Tropical bird assemblages display patterns of high alpha and beta diversity and, as tropical birds exhibit strong habitat specificity, their spatial distributions are generally assumed to be driven primarily by environmental heterogeneity and interspecific interactions. However, spatial distributions of some Amazonian forest birds are also often restricted by large rivers and other large-scale topographic features, suggesting that dispersal limitation may also play a role in driving species' turnover. In this study, we evaluated the effects of environmental characteristics, topographic and spatial variables on variation in local assemblage structure and diversity of birds in an old-growth forest in central Amazonia...
2017: PloS One
Elizaveta A Suturina, Joscha Nehrkorn, Joseph M Zadrozny, Junjie Liu, Mihail Atanasov, Thomas Weyhermüller, Dimitrios Maganas, Stephen Hill, Alexander Schnegg, Eckhard Bill, Jeffrey R Long, Frank Neese
The magnetic properties of pseudotetrahedral Co(II) complexes spawned intense interest after (PPh4)2[Co(SPh)4] was shown to be the first mononuclear transition-metal complex displaying slow relaxation of the magnetization in the absence of a direct current magnetic field. However, there are differing reports on its fundamental magnetic spin Hamiltonian (SH) parameters, which arise from inherent experimental challenges in detecting large zero-field splittings. There are also remarkable changes in the SH parameters of [Co(SPh)4](2-) upon structural variations, depending on the counterion and crystallization conditions...
February 22, 2017: Inorganic Chemistry
Steven C Hayden, Ann Junghans, Jaroslaw Majewski, Millicent Anne Firestone
Neutron reflectometry was used to monitor structural variations in surface supported DMPC bilayers induced by the addition of Triton X-100, a surfactant commonly used to aid solubilization of membrane proteins, and the co-addition of a membrane spanning non-ionic amphiphilic triblock copolymer, (PEO117-PPO47-PEO117, Pluronic F98). Surfactant addition causes slight compression of the bilayer thickness and the creation of a distinct EO layer that increases the hydrophilic layer proximal to the supporting substrate (i...
February 22, 2017: Biomacromolecules
Carla Maya Neckles, Sandra Eltschkner, Jason Ellsworth Cummings, Maria Hirschbeck, Fereidoon Daryaee, Gopal R Bommineni, Zhuo Zhang, Lauren A Spagnuolo, Weixuan Yu, Shabnam Davoodi, Richard A Slayden, Caroline Kisker, Peter J Tonge
There is growing awareness of the link between drug-target residence time and in vivo drug activity, and there are increasing efforts to determine the molecular factors that control the lifetime of a drug-target complex. Rational alterations in drug-target residence time require knowledge of both the ground and transition states on the inhibition reaction coordinate, and we have determined the structure-kinetic relationship for 22 ethyl or hexyl substituted diphenyl ethers that are slow-binding inhibitors of bpFabI1, the enoyl-ACP reductase FabI1 from Burkholderia pseudomallei...
February 22, 2017: Biochemistry
Yooun Heo, Songbai Hu, Pankaj Sharma, Kwang Eun Kim, Byung-Kweon Jang, Claudio Cazorla, Chan-Ho Yang, Jan Seidel
In this study, we report the effect of doping in morphotropic BiFeO3 (BFO) thin films on mechanical properties, revealing variations in the elasticity across the competing phases and their boundaries. Spectroscopic force-distance (F-D) curves and force mapping images by AFM are used to characterize the structure and elastic properties of three BFO thin film materials (pure-BFO, Ca-doped BFO, La-doped BFO). We show that softening behaviour is observed in isovalent La-doped BFO, whereas hardening is seen in aliovalent Ca-doped BFO...
February 22, 2017: ACS Nano
Francois-Marie Allioux, Christopher J Garvey, Christine Rehm, Blaise L Tardy, Raymond Riley Dagastine, Peter D Hodgson, Lingxue Kong, Ludovic Francis Dumée
Ion-exchange membranes are composite separation materials increasingly used in a variety of electro-membranes and electro-chemical processes. Although promising for solvent reclamation, to date, their main applications are limited to aqueous environments due to physico-chemical and microstructural changes of the materials upon exposure to non-aqueous and mixed solvents solutions, affecting long term stability and separation performance. In the present work, the structural changes of commercial and novel hybrid ion-exchange membranes in mixed methanol/water and ethanol/water solutions are assessed for the first time using ultra-and small-angle neutron scattering techniques...
February 22, 2017: ACS Applied Materials & Interfaces
Fuqian Yang
Electrochemical charging of an electrochemical system results in Maxwell stress and a variation in the surface energy of the electrode. The charging-induced variation in the surface energy of the electrode and Maxwell stress introduce mechanical deformation and create stresses in the electrode. To relax the strain energy stored in the electrode, surface cracking and buckling can occur. Under the condition that the charging-induced change in the surface energy is the dominant factor controlling the in-plane deformation of a planar electrode, i...
February 22, 2017: Physical Chemistry Chemical Physics: PCCP
Ayhan Yurtsever, Delia Fernández-Torre, Jo Onoda, Masayuki Abe, Seizo Morita, Yoshiaki Sugimoto, Rubén Pérez
Noble metal nanostructures dispersed on metal oxide surfaces have applications in diverse areas such as catalysis, chemical sensing, and energy harvesting. Their reactivity, chemical selectivity, stability, and light absorption properties are controlled by the interactions at the metal/oxide interface. Single-atom metal adsorbates on the rutile TiO2(110)-(1 × 1) surface have become a paradigmatic model to characterize those interactions and to understand the unique electronic properties of these supported nanostructures...
February 22, 2017: Nanoscale
Dóra Papp, János Sarka, Tamás Szidarovszky, Attila G Császár, Edit Mátyus, Majdi Hochlaf, Thierry Stoecklin
Rotational-vibrational states of the Ar·NO(+) cationic complex are computed, below, above, and well above the complex's first dissociation energy, using variational nuclear motion and close-coupling scattering computations. The HSLH potential energy surface used in this study (J. Chem. Phys., 2011, 135, 044312) is characterized by a first dissociation energy of D0 = 887.0 cm(-1) and supports 200 bound vibrational states. The bound-state vibrational energies and the corresponding wave functions allow the interpretation of the scarcely available experimental results about the intermonomer vibrational motion of the complex...
February 22, 2017: Physical Chemistry Chemical Physics: PCCP
Weihan Li, Shuhe Hu, Xiangyu Luo, Zhongling Li, Xizhen Sun, Minsi Li, Fanfan Liu, Yan Yu
Red phosphorus (P) has attracted intense attention as promising anode material for high-energy density sodium-ion batteries (NIBs), owing to its high sodium storage theoretical capacity (2595 mAh g(-1) ). Nevertheless, natural insulating property and large volume variation of red P during cycling result in extremely low electrochemical activity, leading to poor electrochemical performance. Herein, the authors demonstrate a rational strategy to improve sodium storage performance of red P by confining nanosized amorphous red P into zeolitic imidazolate framework-8 (ZIF-8) -derived nitrogen-doped microporous carbon matrix (denoted as P@N-MPC)...
February 22, 2017: Advanced Materials
Christos Lampros, Costas Papaloukas, Themis Exarchos, Dimitrios I Fotiadis
The limitation of most HMMs is their inherent high dimensionality. Therefore we developed several variations of low complexity models that can be applied even to protein families with a few members. In this chapter we present these variations. All of them include the use of a hidden Markov model (HMM), with a small number of states (called reduced state-space HMM), which is trained with both amino acid sequence and secondary structure of proteins whose 3D structure is known and it is used for protein fold classification...
2017: Methods in Molecular Biology
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