keyword
MENU ▼
Read by QxMD icon Read
search

Dynamed

keyword
https://www.readbyqxmd.com/read/29342400/a-unifying-framework-of-synaptic-and-intrinsic-plasticity-in-neural-populations
#1
Johannes Leugering, Gordon Pipa
A neuronal population is a computational unit that receives a multivariate, time-varying input signal and creates a related multivariate output. These neural signals are modeled as stochastic processes that transmit information in real time, subject to stochastic noise. In a stationary environment, where the input signals can be characterized by constant statistical properties, the systematic relationship between its input and output processes determines the computation carried out by a population. When these statistical characteristics unexpectedly change, the population needs to adapt to its new environment if it is to maintain stable operation...
January 17, 2018: Neural Computation
https://www.readbyqxmd.com/read/29342397/imaging-the-spatiotemporal-dynamics-of-cognitive-processes-at-high-temporal-resolution
#2
I Tal, M Abeles
This letter presents a noninvasive imaging technique that captures the exact timing and locations of cortical activity sequences that are specific to a cognitive process. These precise spatiotemporal sequences can be detected in the human brain as specific time-position pattern associated with a cognitive specific time-position pattern associated with a cognitive task. They are consistent with direct measurements of population activity recorded in nonhuman primates, thus suggesting that specific time-position patterns associated with a cognitive task can be identified...
January 17, 2018: Neural Computation
https://www.readbyqxmd.com/read/29342355/convergence-of-kirkwood-buff-integrals-of-ideal-and-non-ideal-aqueous-solutions-using-molecular-dynamics-simulations
#3
Jasmin Milzetti, Divya Nayar, Nico F A van der Vegt
The computation of Kirkwood-Buff integrals (KBIs) using molecular simulations of closed systems is challenging due to finite system-size effects. One of the problems involves the incorrect asymptotic behavior of the radial distribution function. Corrections to rectify such effects have been proposed in the literature. This study reports a systematic comparison of the proposed corrections (as given by Ganguly et al. J. Chem. Theory Comput. 2013, 9, 1347-1355 and Krueger et al. J. Phys. Chem. Lett. 2013, 4, 4-7) to assess the asymptotic behavior of the RDFs, the KBIs as well as the estimation of thermodynamic quantities for ideal urea--water and non-ideal modified-urea--water mixtures using molecular dynamics simulations...
January 17, 2018: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29342354/a-highly-dynamic-loop-of-the-pseudomonas-aeruginosa-pa14-type-iv-pilin-is-essential-for-pilus-assembly
#4
Ylan Nguyen, Stephen Boulton, E Tyler McNicholl, Madoka Akimoto, Hanjeong Harvey, Francisca Aidoo, Giuseppe Melacini, Lori L Burrows
Type IVa pili (T4aP) are long, thin surface filaments involved in attachment, motility, biofilm formation, and DNA uptake. They are important virulence factors for many bacteria, including Pseudomonas aeruginosa, an opportunistic pathogen and common cause of hospital-acquired infections. Each helical filament contains thousands of monomers of the major pilin subunit, PilA. Each P. aeruginosa strain expresses one of five phylogenetically distinct major pilins, which vary in sequence and the nature of their associated accessory protein(s)...
January 17, 2018: ACS Infectious Diseases
https://www.readbyqxmd.com/read/29342349/membrane-allostery-and-unique-hydrophobic-sites-promote-enzyme-substrate-specificity
#5
Varnavas D Mouchlis, Yuan Chen, J Andrew McCammon, Edward A Dennis
We demonstrate that lipidomics coupled with molecular dynamics reveals unique phospholipase A2 specificity toward membrane phospholipid substrates. We discovered unexpected head-group and acyl-chain specificity for three-major human phospholipases A2. These differences between each enzyme's specificity coupled with molecular dynamicsbased structural and binding studies revealed unique active site and interfacial surface binding moieties for each enzyme that explains the observed specificity at a hitherto inaccessible structural level...
January 17, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29342326/mixed-fluorotryptophan-substitutions-at-the-same-residue-expand-the-versatility-of-%C3%A2-%C3%A2-f-protein-nmr-spectroscopy
#6
Calem Kenward, Kyungsoo Shin, Jan Rainey
The strategy of applying fluorine NMR to characterize ligand binding to a membrane protein prepared with mixtures of tryptophans substituted with F at different positions on the indole ring was tested. The ¹⁹F NMR behavior of 4-, 5-, 6-, and 7-fluorotryptophan were directly compared as a function of both micellar environment and fragment size for two overlapping apelin receptor (AR/APJ) segments - one with a single transmembrane (TM) helix and two tryptophan residues, the other with three TM helices and two additional tryptophan residues...
January 17, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29342285/serial-participation-and-the-ethics-of-phase-1-healthy-volunteer-research
#7
Rebecca L Walker, Marci D Cottingham, Jill A Fisher
Phase 1 healthy volunteer clinical trials-which financially compensate subjects in tests of drug toxicity levels and side effects-appear to place pressure on each joint of the moral framework justifying research. In this article, we review concerns about phase 1 trials as they have been framed in the bioethics literature, including undue inducement and coercion, unjust exploitation, and worries about compromised data validity. We then revisit these concerns in light of the lived experiences of serial participants who are income-dependent on phase 1 trials...
January 12, 2018: Journal of Medicine and Philosophy
https://www.readbyqxmd.com/read/29342280/epigenetic-differentiation-of-natural-populations-of-lilium-bosniacum-associated-with-contrasting-habitat-conditions
#8
V Zoldoš, I Biruš, E Muratovic, Z Šatovic, A Vojta, O Robin, F Pustahija, F Bogunic, V Vicic Bockor, S Siljak-Yakovlev
Epigenetic variation in natural populations with contrasting habitats might be an important element, in addition to the genetic variation, in plant adaptation to environmental stress. Here, we assessed genetic, epigenetic and cytogenetic structure of the three Lilium bosniacum populations growing on distinct habitats. One population was growing under habitual ecological conditions for this species and the other two were growing under stress associated with high altitude and serpentine soil. Amplified fragment length polymorphism (AFLP) and methylation-sensitive amplification polymorphism (MSAP) analyses revealed that the three populations did not differentiate genetically, but were clearly separated in the three distinct clusters according to DNA methylation profiles...
January 12, 2018: Genome Biology and Evolution
https://www.readbyqxmd.com/read/29342276/a-predictive-quantitative-model-of-spiking-activity-and-stimulus-secretion-coupling-in-oxytocin-neurons
#9
Jorge Maícas-Royo, Gareth Leng, Duncan J MacGregor
Oxytocin neurons of the rat hypothalamus project to the posterior pituitary where they secrete their products into the bloodstream. The pattern and quantity of that release depends on the afferent inputs to the neurons, on their intrinsic membrane properties, and on non-linear interactions between spiking activity and exocytosis: a given number of spikes will trigger more secretion when they arrive close together. Here we present a quantitative computational model of oxytocin neurons that can replicate the results of a wide variety of published experiments...
January 12, 2018: Endocrinology
https://www.readbyqxmd.com/read/29342238/rhythmic-spontaneous-activity-mediates-the-age-related-decline-in-somatosensory-function
#10
Rachel K Spooner, Alex I Wiesman, Amy L Proskovec, Elizabeth Heinrichs-Graham, Tony W Wilson
Sensory gating is a neurophysiological process whereby the response to a second stimulus in a pair of identical stimuli is attenuated, and it is thought to reflect the capacity of the CNS to preserve neural resources for behaviorally relevant stimuli. Such gating is observed across multiple sensory modalities and is modulated by age, but the mechanisms involved are not understood. In this study, we examined somatosensory gating in 68 healthy adults using magnetoencephalography (MEG) and advanced oscillatory and time-domain analysis methods...
January 12, 2018: Cerebral Cortex
https://www.readbyqxmd.com/read/29342178/chaos-and-multi-scroll-attractors-in-rcl-shunted-junction-coupled-jerk-circuit-connected-by-memristor
#11
Jun Ma, Ping Zhou, Bashir Ahmad, Guodong Ren, Chunni Wang
In this paper, a new four-variable dynamical system is proposed to set chaotic circuit composed of memristor and Josephson junction, and the dependence of chaotic behaviors on nonlinearity is investigated. A magnetic flux-controlled memristor is used to couple with the RCL-shunted junction circuit, and the dynamical behaviors can be modulated by changing the coupling intensity between the memristor and the RCL-shunted junction. Bifurcation diagram and Lyapunov exponent are calculated to confirm the emergence of chaos in the improved dynamical system...
2018: PloS One
https://www.readbyqxmd.com/read/29342156/specialized-attachment-structure-of-the-fish-pathogenic-oomycete-saprolegnia-parasitica
#12
Svetlana Rezinciuc, Jose Vladimir Sandoval-Sierra, Yolanda Ruiz-León, Pieter van West, Javier Diéguez-Uribeondo
The secondary cysts of the fish pathogen oomycete Saprolegnia parasitica possess bundles of long hooked hairs that are characteristic to this economically important pathogenic species. Few studies have been carried out on elucidating their specific role in the S. parasitica life cycle and the role they may have in the infection process. We show here their function by employing several strategies that focus on descriptive, developmental and predictive approaches. The strength of attachment of the secondary cysts of this pathogen was compared to other closely related species where bundles of long hooked hairs are absent...
2018: PloS One
https://www.readbyqxmd.com/read/29342146/a-theory-of-how-active-behavior-stabilises-neural-activity-neural-gain-modulation-by-closed-loop-environmental-feedback
#13
Christopher L Buckley, Taro Toyoizumi
During active behaviours like running, swimming, whisking or sniffing, motor actions shape sensory input and sensory percepts guide future motor commands. Ongoing cycles of sensory and motor processing constitute a closed-loop feedback system which is central to motor control and, it has been argued, for perceptual processes. This closed-loop feedback is mediated by brainwide neural circuits but how the presence of feedback signals impacts on the dynamics and function of neurons is not well understood. Here we present a simple theory suggesting that closed-loop feedback between the brain/body/environment can modulate neural gain and, consequently, change endogenous neural fluctuations and responses to sensory input...
January 17, 2018: PLoS Computational Biology
https://www.readbyqxmd.com/read/29342142/midbrain-circuits-that-set-locomotor-speed-and-gait-selection
#14
V Caggiano, R Leiras, H Goñi-Erro, D Masini, C Bellardita, J Bouvier, V Caldeira, G Fisone, O Kiehn
Locomotion is a fundamental motor function common to the animal kingdom. It is implemented episodically and adapted to behavioural needs, including exploration, which requires slow locomotion, and escape behaviour, which necessitates faster speeds. The control of these functions originates in brainstem structures, although the neuronal substrate(s) that support them have not yet been elucidated. Here we show in mice that speed and gait selection are controlled by glutamatergic excitatory neurons (GlutNs) segregated in two distinct midbrain nuclei: the cuneiform nucleus (CnF) and the pedunculopontine nucleus (PPN)...
January 17, 2018: Nature
https://www.readbyqxmd.com/read/29342141/monitoring-t-cell-dendritic-cell-interactions-in-vivo-by-intercellular-enzymatic-labelling
#15
Giulia Pasqual, Aleksey Chudnovskiy, Jeroen M J Tas, Marianna Agudelo, Lawrence D Schweitzer, Ang Cui, Nir Hacohen, Gabriel D Victora
Interactions between different cell types are essential for multiple biological processes, including immunity, embryonic development and neuronal signalling. Although the dynamics of cell-cell interactions can be monitored in vivo by intravital microscopy, this approach does not provide any information on the receptors and ligands involved or enable the isolation of interacting cells for downstream analysis. Here we describe a complementary approach that uses bacterial sortase A-mediated cell labelling across synapses of immune cells to identify receptor-ligand interactions between cells in living mice, by generating a signal that can subsequently be detected ex vivo by flow cytometry...
January 17, 2018: Nature
https://www.readbyqxmd.com/read/29342132/centimetre-scale-electron-diffusion-in-photoactive-organic-heterostructures
#16
Quinn Burlingame, Caleb Coburn, Xiaozhou Che, Anurag Panda, Yue Qu, Stephen R Forrest
The unique properties of organic semiconductors, such as flexibility and lightness, are increasingly important for information displays, lighting and energy generation. But organics suffer from both static and dynamic disorder, and this can lead to variable-range carrier hopping, which results in notoriously poor electrical properties, with low electron and hole mobilities and correspondingly short charge-diffusion lengths of less than a micrometre. Here we demonstrate a photoactive (light-responsive) organic heterostructure comprising a thin fullerene channel sandwiched between an electron-blocking layer and a blended donor:C70 fullerene heterojunction that generates charges by dissociating excitons...
January 17, 2018: Nature
https://www.readbyqxmd.com/read/29342113/mitochondria-oxidative-stress-and-the-kynurenine-system-with-a-focus-on-ageing-and-neuroprotection
#17
REVIEW
Katalin Sas, Elza Szabó, László Vécsei
In this review, the potential causes of ageing are discussed. We seek to gain insight into the main physiological functions of mitochondria and discuss alterations in their function and the genome, which are supposed to be the central mechanisms in senescence. We conclude by presenting the potential modulating role of the kynurenine pathway in the ageing processes. Mitochondrial dynamics are supposed to have important physiological roles in maintaining cell homeostasis. During ageing, a decrease in mitochondrial dynamics was reported, potentially compromising the function of mitochondria...
January 17, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29342092/metabolic-alterations-in-cancer-cells-and-the-emerging-role-of-oncometabolites-as-drivers-of-neoplastic-change
#18
REVIEW
Zhengqiu Zhou, Elochukwu Ibekwe, Yevgen Chornenkyy
The mitochondrion is an important organelle and provides energy for a plethora of intracellular reactions. Metabolic dysregulation has dire consequences for the cell, and alteration in metabolism has been identified in multiple disease states-cancer being one. Otto Warburg demonstrated that cancer cells, in the presence of oxygen, undergo glycolysis by reprogramming their metabolism-termed "aerobic glycolysis". Alterations in metabolism enable cancer cells to gain a growth advantage by obtaining precursors for macromolecule biosynthesis, such as nucleic acids and lipids...
January 17, 2018: Antioxidants (Basel, Switzerland)
https://www.readbyqxmd.com/read/29342083/regulation-of-mitochondrial-dynamics-by-proteolytic-processing-and-protein-turnover
#19
REVIEW
Sumaira Ali, Gavin P McStay
The mitochondrial network is a dynamic organization within eukaryotic cells that participates in a variety of essential cellular processes, such as adenosine triphosphate (ATP) synthesis, central metabolism, apoptosis and inflammation. The mitochondrial network is balanced between rates of fusion and fission that respond to pathophysiologic signals to coordinate appropriate mitochondrial processes. Mitochondrial fusion and fission are regulated by proteins that either reside in or translocate to the inner or outer mitochondrial membranes or are soluble in the inter-membrane space...
January 17, 2018: Antioxidants (Basel, Switzerland)
https://www.readbyqxmd.com/read/29342080/comparisons-of-different-models-on-dynamic-recrystallization-of-plate-during-asymmetrical-shear-rolling
#20
Tao Zhang, Lei Li, Shi-Hong Lu, Hai Gong, Yun-Xin Wu
Asymmetrical shear rolling with velocity asymmetry and geometry asymmetry is beneficial to enlarge deformation and refine grain size at the center of the thick plate compared to conventional symmetrical rolling. Dynamic recrystallization (DRX) plays a vital role in grain refinement during hot deformation. Finite element models (FEM) coupled with microstructure evolution models and cellular automata models (CA) are established to study the microstructure evolution of plate during asymmetrical shear rolling. The results show that a larger DRX fraction and a smaller average grain size can be obtained at the lower layer of the plate...
January 17, 2018: Materials
keyword
keyword
103148
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"