keyword
MENU ▼
Read by QxMD icon Read
search

Manifold

keyword
https://www.readbyqxmd.com/read/28227667/evaluation-of-a-mixed-controller-that-amplifies-spatial-errors-while-reducing-timing-errors
#1
Laura Marchal-Crespo, Tanja Baumann, Daniela Fichmann, Steve Maassen, Jaime E Duarte, Robert Riener, Laura Marchal-Crespo, Tanja Baumann, Daniela Fichmann, Steve Maassen, Jaime E Duarte, Robert Riener, Robert Riener, Steve Maassen, Tanja Baumann, Laura Marchal-Crespo, Daniela Fichmann, Jaime E Duarte
Previous results suggest that haptic guidance enhances learning of the timing components of motor tasks, whereas error amplification is better for learning the spatial components. In this paper we evaluate a novel mixed guidance controller that combines haptic guidance and error amplification to simultaneously promote learning of the timing and spatial components. The controller is realized using a saddle-like force field around the desired movement position. This force field has a stable manifold tangential to the trajectory that guides subjects in velocity related aspects...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226744/toward-a-severity-index-for-rop-an-unsupervised-approach
#2
Peng Tian, Esra Ataer-Cansizoglu, Jayashree Kalpathy-Cramer, Susan Ostmo, Karyn Jonas, R V Paul Chan, J Peter Campbell, Michael F Chiang, Deniz Erdogmus, Peng Tian, Esra Ataer-Cansizoglu, Jayashree Kalpathy-Cramer, Susan Ostmo, Karyn Jonas, R V Paul Chan, J Peter Campbell, Michael F Chiang, Deniz Erdogmus, Michael F Chiang, Esra Ataer-Cansizoglu, Peng Tian, Deniz Erdogmus, J Peter Campbell, Jayashree Kalpathy-Cramer, R V Paul Chan, Susan Ostmo, Karyn Jonas
Retinopathy of prematurity (ROP) is a disease affecting low birth-weight infants and is the major cause of childhood blindness. Although accurate diagnosis is important, there is a high variability among expert decisions mostly due to subjective thresholds. Existing work focused on automated diagnosis of ROP. In this study, we construct a continuous severity index as an alternative to discrete classification. We follow an unsupervised approach by performing nonlinear dimensionality reduction. Instead of extracting several statistics of image features, each image is represented by the probability distribution of its features...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226432/reinforcement-learning-for-stabilizing-an-inverted-pendulum-naturally-leads-to-intermittent-feedback-control-as-in-human-quiet-standing
#3
Kenjiro Michimoto, Yasuyuki Suzuki, Ken Kiyono, Yasushi Kobayashi, Pietro Morasso, Taishin Nomura, Kenjiro Michimoto, Yasuyuki Suzuki, Ken Kiyono, Yasushi Kobayashi, Pietro Morasso, Taishin Nomura, Ken Kiyono, Pietro Morasso, Kenjiro Michimoto, Yasushi Kobayashi, Yasuyuki Suzuki, Taishin Nomura
Intermittent feedback control for stabilizing human upright stance is a promising strategy, alternative to the standard time-continuous stiffness control. Here we show that such an intermittent controller can be established naturally through reinforcement learning. To this end, we used a single inverted pendulum model of the upright posture and a very simple reward function that gives a certain amount of punishments when the inverted pendulum falls or changes its position in the state space. We found that the acquired feedback controller exhibits hallmarks of the intermittent feedback control strategy, namely the action of the feedback controller is switched-off intermittently when the state of the pendulum is located near the stable manifold of the unstable saddle-type upright equilibrium of the inverted pendulum with no active control: this action provides an opportunity to exploit transiently converging dynamics toward the unstable upright position with no help of the active feedback control...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28220764/dimensionality-reduction-based-on-distance-preservation-to-local-mean-dplm-for-spd-matrices-and-its-application-in-bci
#4
Alireza Davoudi, Saeed Shiry Ghidary, Khadijeh Sadatnejad
OBJECTIVE: In this paper, we propose a nonlinear dimensionality reduction algorithm for the manifold of Symmetric Positive Definite (SPD) matrices that considers the geometry of SPD matrices and provides a low dimensional representation of the manifold with high class discrimination in a supervised or unsupervised manner. APPROACH: The proposed algorithm, tries to preserve the local structure of the data by preserving distances to local means (DPLM) and also provides an implicit projection matrix...
February 21, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28218214/antidepressant-effects-of-electroconvulsive-therapy-unrelated-to-the-brain-s-functional-network-connectivity-alterations-at-an-individual-level
#5
Guang-Dong Chen, Feng Ji, Gong-Ying Li, Bo-Xuan Lyu, Wei Hu, Chuan-Jun Zhuo
BACKGROUND: Electroconvulsive therapy (ECT) can alleviate the symptoms of treatment-resistant depression (TRD). Functional network connectivity (FNC) is a newly developed method to investigate the brain's functional connectivity patterns. The first aim of this study was to investigate FNC alterations between TRD patients and healthy controls. The second aim was to explore the relationship between the ECT treatment response and pre-ECT treatment FNC alterations in individual TRD patients...
2017: Chinese Medical Journal
https://www.readbyqxmd.com/read/28214692/multi-view-clustering-via-multi-manifold-regularized-non-negative-matrix-factorization
#6
Linlin Zong, Xianchao Zhang, Long Zhao, Hong Yu, Qianli Zhao
Non-negative matrix factorization based multi-view clustering algorithms have shown their competitiveness among different multi-view clustering algorithms. However, non-negative matrix factorization fails to preserve the locally geometrical structure of the data space. In this paper, we propose a multi-manifold regularized non-negative matrix factorization framework (MMNMF) which can preserve the locally geometrical structure of the manifolds for multi-view clustering. MMNMF incorporates consensus manifold and consensus coefficient matrix with multi-manifold regularization to preserve the locally geometrical structure of the multi-view data space...
February 8, 2017: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/28214347/involvement-of-the-guanine-nucleotide-exchange-factor-vav3-in-central-nervous-system-development-and-plasticity
#7
Annika Ulc, Christine Gottschling, Ina Schäfer, David Wegrzyn, Simon van Leeuwen, Veronika Luft, Jacqueline Reinhard, Andreas Faissner
Small GTP-hydrolysing enzymes (GTPases) of the RhoA family play manifold roles in cell biology and are regulated by upstream guanine nucleotide exchange factors (GEFs). Herein, we focus on the GEFs of the Vav subfamily. Vav1 was originally described as a protooncogene of the hematopoietic lineage. The GEFs Vav2 and Vav3 are more broadly expressed in various tissues. In particular, the GEF Vav3 may play important roles in the developing nervous system during the differentiation of neural stem cells into the major lineages, namely neurons, oligodendrocytes and astrocytes...
February 18, 2017: Biological Chemistry
https://www.readbyqxmd.com/read/28213250/novel-electroanalytical-method-based-on-the-electrostriction-phenomenon-and-its-application-to-determination-of-cr-vi-by-the-flow-injection-technique
#8
Marcin Wieczorek, Jolanta Kochana, Paweł Knihnicki, Karolina Wapiennik, Paweł Kościelniak
The electrostriction phenomenon is observed in membranes of thickness in the nanometer range, e.g. bilayer lipid membranes or self-assembled monolayers. Strong electrical field of 105-106V/cm in intensity appears when applying the potential lower than 1V to these membranes. Electrostatic forces change the dimensions of a dielectric, hence the membrane compression and decrease in thickness are observed. As a result, increase in the membrane capacitance is recorded. The presented work covers development and application of a new analytical method based on the innovative capacitance-to-frequency conversion method and flow technique...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28211496/the-use-of-bright-and-dark-types-of-humour-is-rooted-in-the-brain
#9
Ilona Papousek, Willibald Ruch, Christian Rominger, Elisabeth Kindermann, Katharina Scheidl, Günter Schulter, Andreas Fink, Elisabeth M Weiss
The ways in which humour can be used are related to the manifold interpersonal functions humour can serve, some of which are positive, and some negative. In the present study, phasic changes in the functional coupling of prefrontal and posterior cortex (EEG coherence) during other people's auditory displays of happy and sad mood were recorded to predict people's typical use of humour in social interactions. Greater use of benevolent humour, the intentions of which are in keeping with the characteristics of "laughing-with" humour, was associated with greater decreases of prefrontal-posterior coupling during the processing of happy laughter...
February 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28208588/depicting-binding-mediated-translocation-of-hiv-1-tat-peptides-in-living-cells-with-nanoscale-pens-of-tat-conjugated-quantum-dots
#10
Chien Y Lin, Jung Y Huang, Leu-Wei Lo
Cell-penetrating peptides (CPPs) can translocate across cell membranes, and thus have great potential for the cellular delivery of macromolecular cargoes. However, the mechanism of this cellular uptake process is not yet fully understood. In this study, a time-lapse single-particle light-sheet microscopy technique was implemented to obtain a parallel visualization of the translocating process of individual human immunodeficiency virus 1 (HIV-1) transactivator of transcription (Tat) peptide conjugated quantum dots (TatP-QDs) in complex cellular terrains...
February 10, 2017: Sensors
https://www.readbyqxmd.com/read/28197906/functions-of-sumo-in-the-maintenance-of-genome-stability
#11
Nicola Zilio, Karolin Eifler-Olivi, Helle D Ulrich
Like in most other areas of cellular metabolism, the functions of the ubiquitin-like modifier SUMO in the maintenance of genome stability are manifold and varied. Perturbations of global sumoylation causes a wide spectrum of phenotypes associated with defects in DNA maintenance, such as hypersensitivity to DNA-damaging agents, gross chromosomal rearrangements and loss of entire chromosomes. Consistent with these observations, many key factors involved in various DNA repair pathways have been identified as SUMO substrates...
2017: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/28195376/irreversible-cysteine-selective-protein-labeling-employing-modular-electrophilic-tetrafluoroethylation-reagents
#12
Jiří Václavík, Reinhard Zschoche, Iveta Klimánková, Václav Matoušek, Petr Beier, Donald Hilvert, Antonio Togni
Fluoroalkylation reagents based on hypervalent iodine are widely used to transfer fluoroalkyl moieties to various nucleophiles. However, the transferred groups have so far been limited to simple structural motifs. We herein report a reagent featuring a secondary amine that can be converted to amide, sulfonamide, and tertiary amine derivatives in the last step. The resulting reagents bear manifold functional groups, many of which would not be compatible with the original synthetic pathway. Exploiting this structural versatility and the known high reactivity toward thiols, the new-generation reagents were used in bioconjugation with an artificial retro-aldolase, containing an exposed cysteine and a reactive catalytic lysine...
February 13, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28193273/stub1-chip-mutations-cause-gordon-holmes-syndrome-as-part-of-a-widespread-multisystemic-neurodegeneration-evidence-from-four-novel-mutations
#13
Stefanie Nicole Hayer, Tine Deconinck, Benjamin Bender, Katrien Smets, Stephan Züchner, Selina Reich, Ludger Schöls, Rebecca Schüle, Peter De Jonghe, Jonathan Baets, Matthis Synofzik
BACKGROUND: CHIP, the protein encoded by STUB1, is a central component of cellular protein homeostasis and interacts with several key proteins involved in the pathogenesis of manifold neurodegenerative diseases. This gives rise to the hypothesis that mutations in STUB1 might cause a far more multisystemic neurodegenerative phenotype than the previously reported cerebellar ataxia syndrome. METHODS: Whole exome sequencing data-sets from n = 87 index subjects of two ataxia cohorts were screened for individuals with STUB1 mutations...
February 13, 2017: Orphanet Journal of Rare Diseases
https://www.readbyqxmd.com/read/28192389/synthesis-and-characterization-of-triangulene
#14
Niko Pavliček, Anish Mistry, Zsolt Majzik, Nikolaj Moll, Gerhard Meyer, David J Fox, Leo Gross
Triangulene, the smallest triplet-ground-state polybenzenoid (also known as Clar's hydrocarbon), has been an enigmatic molecule ever since its existence was first hypothesized. Despite containing an even number of carbons (22, in six fused benzene rings), it is not possible to draw Kekulé-style resonant structures for the whole molecule: any attempt results in two unpaired valence electrons. Synthesis and characterization of unsubstituted triangulene has not been achieved because of its extreme reactivity, although the addition of substituents has allowed the stabilization and synthesis of the triangulene core and verification of the triplet ground state via electron paramagnetic resonance measurements...
February 13, 2017: Nature Nanotechnology
https://www.readbyqxmd.com/read/28190641/emergence-of-coordinated-neural-dynamics-underlies-neuroprosthetic-learning-and-skillful-control
#15
Vivek R Athalye, Karunesh Ganguly, Rui M Costa, Jose M Carmena
During motor learning, movements and underlying neural activity initially exhibit large trial-to-trial variability that decreases over learning. However, it is unclear how task-relevant neural populations coordinate to explore and consolidate activity patterns. Exploration and consolidation could happen for each neuron independently, across the population jointly, or both. We disambiguated among these possibilities by investigating how subjects learned de novo to control a brain-machine interface using neurons from motor cortex...
February 22, 2017: Neuron
https://www.readbyqxmd.com/read/28188642/engineering-of-ruthenium-ii-oxy-and-carboxyamido-quinolate-non-innocent-ligand-photosensitizers-for-dye-sensitized-solar-cells
#16
Ken Tue Ngo, Nicholas A Lee, Sashari Pinnace, Jonathan Rochford
An alternative approach towards the replacement of the isothiocyantate ligands of the N3 photosensitizer with light-harvesting bidentate ligands is investigated for application in dye-sensitized solar cells. An in depth theoretical analysis has been applied to inform on the optical and redox properties of four non-innocent ligand platforms which is corroborated with experiment. Taking advantage of the 5- and 7-positions of 8-oxyquinolate, or the carboxyaryl ring system of the N-arylcarboxy-8-amidoquinolate ligand, fluorinated aryl substituents are demonstrated as an effective means to tune complex redox potentials and light harvesting properties...
February 11, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28187966/bioremoval-of-trace-metals-from-rhizosediment-by-mangrove-plants-in-indian-sundarban-wetland
#17
Ranju Chowdhury, Paulo J C Favas, M P Jonathan, Perumal Venkatachalam, P Raja, Santosh Kumar Sarkar
The study accentuated the trace metal accumulation and distribution pattern in individual organs of 13 native mangrove plants along with rhizosediments in the Indian Sundarban Wetland. Enrichment of the essential micronutrients (Mn, Fe, Zn, Cu, Co, Ni) was recorded in all plant organs in comparison to non-essential ones, such as Cr, As, Pb, Cd, Hg. Trunk bark and root/pneumatophore showed maximum metal accumulation efficiency. Rhizosediment recorded manifold increase for most of the trace metals than plant tissue, with the following descending order: Fe>Mn>Zn>Cu>Pb>Ni>Cr>Co>As>Cd>Hg...
February 7, 2017: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/28187426/clustering-of-biological-datasets-in-the-era-of-big-data
#18
Richard Röttger
Clustering is a long-standing problem in computer science and is applied in virtually any scientific field for exploring the inherent structure of datasets. In biomedical research, clustering tools have been utilized in manifold areas, among many others in expression analysis, disease subtyping or protein research. A plethora of different approaches have been developed but there is only little guideline what approach is the optimal in what particular situation. Furthermore, a typical cluster analysis is an entire process with several highly interconnected steps; from preprocessing, proximity calculation, the actual clustering to evaluation and optimization...
December 22, 2016: Journal of Integrative Bioinformatics
https://www.readbyqxmd.com/read/28185401/light-driven-enantioselective-organocatalytic-%C3%AE-benzylation-of-enals
#19
Luca Dell'Amico, Victor M Fernández-Alvarez, Feliu Maseras, Paolo Melchiorre
A photochemical organocatalytic strategy for the direct enantioselective β-benzylation of α,β-unsaturated aldehydes is reported. The chemistry capitalizes upon the light-triggered enolization of 2-alkyl-benzophenones to afford hydroxy-o-quinodinomethanes. These fleeting intermediates are stereoselectively intercepted by chiral iminium ions, transiently formed upon condensation of a secondary amine catalyst with enals. Density functional theory (DFT) studies provided an explanation for why the reaction proceeds through an unconventional Michael-type addition manifold, instead of a classical cycloaddition mechanism and subsequent ring-opening...
February 10, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28184304/the-%C3%AE-ketoglutarate-dehydrogenase-complex-in-cancer-metabolic-plasticity
#20
REVIEW
Renaud Vatrinet, Giulia Leone, Monica De Luise, Giulia Girolimetti, Michele Vidone, Giuseppe Gasparre, Anna Maria Porcelli
Deregulated metabolism is a well-established hallmark of cancer. At the hub of various metabolic pathways deeply integrated within mitochondrial functions, the α-ketoglutarate dehydrogenase complex represents a major modulator of electron transport chain activity and tricarboxylic acid cycle (TCA) flux, and is a pivotal enzyme in the metabolic reprogramming following a cancer cell's change in bioenergetic requirements. By contributing to the control of α-ketoglutarate levels, dynamics, and oxidation state, the α-ketoglutarate dehydrogenase is also essential in modulating the epigenetic landscape of cancer cells...
2017: Cancer & Metabolism
keyword
keyword
37882
1
2
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"