Read by QxMD icon Read

Grid cells

Nina Jendrike, Annette Baumstark, Stefan Pleus, Christina Liebing, Alexandra Beer, Frank Flacke, Cornelia Haug, Guido Freckmann
BACKGROUND: Self-monitoring of blood glucose (SMBG) is important in diabetes therapy; however, not all SMBG systems are sufficiently accurate. In addition, some SMBG systems are influenced by the user's hematocrit value. METHODS: System accuracy and hematocrit influence was evaluated for four SMBG systems with built-in insulin dose advisors (Accu-Chek® Aviva Expert [1], FreeStyle InsuLinx [2], FreeStyle Precision Neo [3], MyStar DoseCoach® [4]) based on International Organization for Standardization (ISO) 15197:2013 section 6...
April 2018: Diabetes Technology & Therapeutics
João M Medeiros, Désirée Böck, Gregor L Weiss, Romain Kooger, Roger A Wepf, Martin Pilhofer
Electron cryotomography is able to visualize macromolecular complexes in their cellular context, in a frozen-hydrated state, and in three dimensions. The method, however, is limited to relatively thin samples. Cryo-focused ion beam (FIB) milling is emerging as a powerful technique for sample thinning prior to cryotomography imaging. Previous cryo-FIB milling reports utilized custom-built non-standard equipment. Here we present a workflow and the required commercially available instrumentation to either implement the method de novo, or as an upgrade of pre-existing dual beam milling instruments...
April 6, 2018: Ultramicroscopy
Charles W Bangley, Lee Paramore, Simon Dedman, Roger A Rulifson
Estuaries function as important nursery and foraging habitats for many coastal species, including highly migratory sharks. Pamlico Sound, North Carolina, is one of the largest estuaries in the continental United States and provides a variety of potential habitats for sharks. In order to identify and spatially delineate shark habitats within Pamlico Sound, shark catch and environmental data were analyzed from the 2007-2014 North Carolina Division of Marine Fisheries (NCDMF) gillnet and longline surveys conducted within the estuary...
2018: PloS One
Jeremiah P Hartner, Laura A Schrader
Spatial memory processing requires functional interaction between the hippocampus and the medial entorhinal cortex (MEC). The grid cells of the MEC are most abundant in layer II and rely on a complex network of local inhibitory interneurons to generate spatial firing properties. Stress can cause spatial memory deficits in males, but the specific underlying mechanisms affecting the known memory pathways remain unclear. Stress activates both the autonomic nervous system and the hypothalamic-pituitary-adrenal axis to release norepinephrine (NE) and glucocorticoids, respectively...
2018: Frontiers in Synaptic Neuroscience
Stefan Sellman, Kimberly Tsao, Michael J Tildesley, Peter Brommesson, Colleen T Webb, Uno Wennergren, Matt J Keeling, Tom Lindström
Numerical models for simulating outbreaks of infectious diseases are powerful tools for informing surveillance and control strategy decisions. However, large-scale spatially explicit models can be limited by the amount of computational resources they require, which poses a problem when multiple scenarios need to be explored to provide policy recommendations. We introduce an easily implemented method that can reduce computation time in a standard Susceptible-Exposed-Infectious-Removed (SEIR) model without introducing any further approximations or truncations...
April 6, 2018: PLoS Computational Biology
Rebecca Saive, Harry A Atwater
We report on a computational study exploring the design of mesoscale metallic front contacts for solar cells. We investigated silver contact structures with circle, triangle and square cross-sections for various length scales and surface coverages. We found that for 'nanoscale' contacts with widths between 10 nm and 1000 nm, resonant coupling actually impairs light absorption in the semiconductor. Conversely, for 'mesoscale' contact widths > 1000 nm, the light interaction is determined by the geometric shadowing...
March 19, 2018: Optics Express
Zhouhui Xia, Peng Gao, Teng Sun, Haihua Wu, Yeshu Tan, Tao Song, Shuit-Tong Lee, Baoquan Sun
Silicon (Si)/organic heterojunction solar cells based on poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) and n-type Si have attracted wide interests because they promise cost-effective and high-efficiency. However, the limited conductivity of PEDOT:PSS leads to an inefficient hole transport efficiency for the heterojunction device. Therefore, a high dense top-contact metal grid electrode is required to assure the efficient charge collection efficiency. Unfortunately, the large metal grid coverage ratio electrode would lead to undesirable optical loss...
April 2, 2018: ACS Applied Materials & Interfaces
Juan Prada, Manju Sasi, Corinna Martin, Sibylle Jablonka, Thomas Dandekar, Robert Blum
Local and spontaneous calcium signals play important roles in neurons and neuronal networks. Spontaneous or cell-autonomous calcium signals may be difficult to assess because they appear in an unpredictable spatiotemporal pattern and in very small neuronal loci of axons or dendrites. We developed an open source bioinformatics tool for an unbiased assessment of calcium signals in x,y-t imaging series. The tool bases its algorithm on a continuous wavelet transform-guided peak detection to identify calcium signal candidates...
March 30, 2018: PLoS Computational Biology
Yury M Kulikov, Eduard E Son
In present paper we recall the canonical Taylor-Green vortex problem solved by in-house implementation of the novel CABARET numerical scheme in weakly compressible formulation. The simulations were carried out on the sequence of refined grids with [Formula: see text], [Formula: see text], [Formula: see text] cells at various Reynolds numbers corresponding to both laminar ([Formula: see text]) and turbulent ([Formula: see text]) vortex decay scenarios. The features of the numerical method are discussed in terms of the kinetic energy dissipation rate and integral enstrophy curves, temporal evolution of the spanwise vorticity, energy spectra and spatial correlation functions...
March 27, 2018: European Physical Journal. E, Soft Matter
Beatriz E Amendola, Naipy C Perez, Xiaodong Wu, Jesus Manuel Blanco Suarez, Jiade J Lu, Marco Amendola
The Lattice Radiotherapy (LRT) technique is mainly based on the GRID technology with the improved feature of the 3D treatment delivery. A 72 year old male presented with left shoulder pain due to a 6 cm pulmonary mass in the left upper lobe (LUL) histologically proven Non-Small Cell Lung Cancer (NSCLC) stage IIIA. In July 2011 he was treated in our center with LRT followed by conventional fractionated Volumetric Modulated Arc Therapy (VMAT) combined with chemotherapy. Clinical and imaging follow up of 6 years demonstrated continued improvement and the patient is currently with no evidence of disease (NED)...
February 2018: Clinical and Translational Radiation Oncology
Julija Krupic, Marius Bauza, Stephen Burton, John O'Keefe
Grid cells are neurons active in multiple fields arranged in a hexagonal lattice and are thought to represent the "universal metric for space." However, they become nonhomogeneously distorted in polarized enclosures, which challenges this view. We found that local changes to the configuration of the enclosure induce individual grid fields to shift in a manner inversely related to their distance from the reconfigured boundary. The grid remained primarily anchored to the unchanged stable walls and showed a nonuniform rescaling...
March 9, 2018: Science
Laura Moyal, Esther Blumen-Ohana, Marc Blumen, Cybele Blatrix, Frederic Chabolle, Jean-Philippe Nordmann
AIMS: To compare optic disc perfusion, radial peripapillary capillaries (RPC) and macular vascular density, between normal subjects and subjects with obstructive sleep apnea syndrome (OSAS) using spectral-domain OCT angiography (OCTA). METHODS: Sixteen eyes of patients with mild OSAS, 17 eyes with moderate OSAS, 20 eyes with severe OSAS on polygraphy and 28 controls were evaluated with OCTA RT XR Avanti (AngioVue software, Optovue Inc., Fremont, CA). Optic nerve head (ONH), RPC and macular vessel density were measured...
March 25, 2018: Graefe's Archive for Clinical and Experimental Ophthalmology
Muhammed S Alluwimi, William H Swanson, Victor E Malinovsky, Brett J King
Purpose: Prior studies suggested the use of customized perimetric locations in glaucoma; these studies were limited by imaging only the superficial depths of the retinal nerve fiber layer (RNFL) and by prolonged perimetric testing. We aimed to develop a rapid perimetric test guided by high-resolution images of RNFL bundles. Methods: We recruited 10 patients with glaucoma, ages 56 to 80 years, median 68 years, and 10 controls, ages 55 to 77 years, median 68 years...
March 2018: Translational Vision Science & Technology
Karthik Soman, Vignesh Muralidharan, V Srinivasa Chakravarthy
Spatial cells in the hippocampal complex play a pivotal role in the navigation of an animal. Exact neural principles behind these spatial cell responses have not been completely unraveled yet. Here we present two models for spatial cells namely the Velocity Driven Oscillatory Network and Locomotor Driven Oscillatory Network. Both models have basically three stages in common such as direction encoding stage, path integration stage and a stage of unsupervised learning of path integration values. In the first model, the following three stages are implemented: head direction layer, frequency modulation by a layer of oscillatory neurons, and an unsupervised stage that extracts the Principal Components from the oscillator outputs...
March 25, 2018: European Journal of Neuroscience
Fang Liu, Robert M Hoffman
The stem cell marker, nestin, is expressed in the hair follicle, both in cells in the bulge area (BA) and the dermal papilla (DP). Nestin-expressing hair follicle-associated-pluripotent (HAP) stem cells of both the BA and DP have been previously shown to be able to form neurons, heart muscle cells, and other non-follicle cell types. The ability of the nestin-expressing HAP stem cells from the BA and DP to repair spinal cord injury was compared. Nestin-expressing HAP stem cells from both the BA and DP grew very well on Gelfoam® ...
2018: Methods in Molecular Biology
Magdalene I Schlesiger, Brittney L Boublil, Jena B Hales, Jill K Leutgeb, Stefan Leutgeb
The high storage capacity of the episodic memory system relies on distinct representations for events that are separated in time and space. The spatial component of these computations includes the formation of independent maps by hippocampal place cells across environments, referred to as global remapping. Such remapping is thought to emerge by the switching of input patterns from specialized spatially selective cells in medial entorhinal cortex (mEC), such as grid and border cells. Although it has been shown that acute manipulations of mEC firing patterns are sufficient for inducing hippocampal remapping, it remains unknown whether specialized spatial mEC inputs are necessary for the reorganization of hippocampal spatial representations...
March 20, 2018: Cell Reports
Alessia Ongaro, Luca Giovanni Campana, Monica De Mattei, Paolo Di Barba, Fabrizio Dughiero, Michele Forzan, Maria Evelina Mognaschi, Agnese Pellati, Carlo Riccardo Rossi, Clara Bernardello, Elisabetta Sieni
Electrochemotherapy is an emerging local treatment for the management of superficial tumors and, among these, also chest wall recurrences from breast cancer. Generally, the treatment of this peculiar type of tumor requires the coverage of large skin areas. In these cases, electrochemotherapy treatment by means of standard small size needle electrodes (an array of 0.73 cm spaced needles, which covers an area of 1.5 cm2 ) is time-consuming and can allow an inhomogeneous coverage of the target area. We have previously designed grid devices suitable for treating an area ranging from 12 to 200 cm2 ...
January 1, 2018: Technology in Cancer Research & Treatment
Poorna Subramanian, Sahand Pirbadian, Mohamed Y El-Naggar, Grant J Jensen
Bacterial nanowires have garnered recent interest as a proposed extracellular electron transfer (EET) pathway that links the bacterial electron transport chain to solid-phase electron acceptors away from the cell. Recent studies showed that Shewanella oneidensis MR-1 produces outer membrane (OM) and periplasmic extensions that contain EET components and hinted at their possible role as bacterial nanowires. However, their fine structure and distribution of cytochrome electron carriers under native conditions remained unclear, making it difficult to evaluate the potential electron transport (ET) mechanism along OM extensions...
March 19, 2018: Proceedings of the National Academy of Sciences of the United States of America
J J García-Medina, M Del-Rio-Vellosillo, A Palazón-Cabanes, M Tudela-Molino, C Gómez-Molina, A Guardiola-Fernández, M P Villegas-Pérez
OBJECTIVES: To evaluate changes in retinal layers of the macula (mRLs) using OCT posterior pole program (PPP) in primary open-angle glaucoma (POAG). MATERIAL AND METHODS: The study included 128 patients with POAG and 103 healthy controls who had PPP maps (macular grid 8×8) drawn by SD-OCT. Only one eye per patient was studied. The 9 mRLs were automatically segmented by prototype software, obtaining: a macular retinal nerve fibre layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform+nuclear layer, photoreceptor layer, retinal pigment epithelium (RPE), outer retina and RPE+outer retina...
March 16, 2018: Archivos de la Sociedad Española de Oftalmología
Matthias Stangl, Johannes Achtzehn, Karin Huber, Caroline Dietrich, Claus Tempelmann, Thomas Wolbers
A progressive loss of navigational abilities in old age has been observed in numerous studies, but we have only limited understanding of the neural mechanisms underlying this decline [1]. A central component of the brain's navigation circuit are grid cells in entorhinal cortex [2], largely thought to support intrinsic self-motion-related computations, such as path integration (i.e., keeping track of one's position by integrating self-motion cues) [3-6]. Given that entorhinal cortex is particularly vulnerable to neurodegenerative processes during aging and Alzheimer's disease [7-14], deficits in grid cell function could be a key mechanism to explain age-related navigational decline...
March 12, 2018: Current Biology: CB
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"