scholarly journals Biased competition in the absence of input bias revealed through corticostriatal computation

2019 ◽  
Vol 116 (17) ◽  
pp. 8564-8569 ◽  
Author(s):  
Salva Ardid ◽  
Jason S. Sherfey ◽  
Michelle M. McCarthy ◽  
Joachim Hass ◽  
Benjamin R. Pittman-Polletta ◽  
...  
Keyword(s):  
Firing Rate ◽  
Rhythmic Activity ◽  
High Strength ◽  
Downstream Processing ◽  
Projection Neurons ◽  
Biased Competition ◽  
Cortical Input ◽  
Neuronal Ensembles ◽  
Input Strength ◽  
Selection Of

Classical accounts of biased competition require an input bias to resolve the competition between neuronal ensembles driving downstream processing. However, flexible and reliable selection of behaviorally relevant ensembles can occur with unbiased stimulation: striatal D1 and D2 spiny projection neurons (SPNs) receive balanced cortical input, yet their activity determines the choice between GO and NO-GO pathways in the basal ganglia. We here present a corticostriatal model identifying three mechanisms that rely on physiological asymmetries to effect rate- and time-coded biased competition in the presence of balanced inputs. First, tonic input strength determines which one of the two SPN phenotypes exhibits a higher mean firing rate. Second, low-strength oscillatory inputs induce higher firing rate in D2 SPNs but higher coherence between D1 SPNs. Third, high-strength inputs oscillating at distinct frequencies can preferentially activate D1 or D2 SPN populations. Of these mechanisms, only the latter accommodates observed rhythmic activity supporting rule-based decision making in prefrontal cortex.

scholarly journals Biased competition in the absence of input bias: predictions from corticostriatal computation

2018 ◽  
Author(s):  
Salva Ardid ◽  
Jason S. Sherfey ◽  
Michelle M. McCarthy ◽  
Joachim Hass ◽  
Benjamin R. Pittman-Polletta ◽  
...  
Keyword(s):  
Decision Making ◽  
Rhythmic Activity ◽  
High Strength ◽  
Downstream Processing ◽  
Biased Competition ◽  
Rule Based ◽  
Cortical Input ◽  
Neuronal Ensembles ◽  
Input Strength ◽  
Selection Of

Classical accounts of biased competition (BC) require an input bias to resolve the competition between neuronal ensembles driving downstream processing. However, flexible and reliable selection of behaviorally-relevant ensembles can occur with unbiased stimulation: striatal D1 and D2 spiny projecting neurons (SPNs) receive balanced cortical input, yet their activity determines the choice between GO and NO-GO pathways in the basal ganglia. We present a corticostriatal model identifying three mechanisms that rely on physiological asymmetries to effect rate- and time-coded BC in the presence of balanced inputs. First, tonic input strength determines which SPN phenotype exhibit higher mean firing rate (FR). Second, low strength oscillatory inputs induce higher FR in D2 SPNs but higher coherence between D1 SPNs. Third, high strength inputs oscillating at distinct frequencies preferentially activate D1 or D2 SPN populations. Of these mechanisms, the latter accommodates observed rhythmic activity supporting rule-based decision making in prefrontal cortex.

Musical Features that Aid Sleep

2020 ◽  
pp. 102986492097216
Author(s):  
Gaelen Thomas Dickson ◽  
Emery Schubert
Keyword(s):  
Information Retrieval ◽  
Online Survey ◽  
Music Information Retrieval ◽  
Rhythmic Activity ◽  
Main Frequency ◽  
Middle Range ◽  
Major Mode ◽  
Information Retrieval Methods ◽  
Music Information ◽  
Selection Of

Background: Music is thought to be beneficial as a sleep aid. However, little research has explicitly investigated the specific characteristics of music that aid sleep and some researchers assume that music described as generically sedative (slow, with low rhythmic activity) is necessarily conducive to sleep, without directly interrogating this assumption. This study aimed to ascertain the features of music that aid sleep. Method: As part of an online survey, 161 students reported the pieces of music they had used to aid sleep, successfully or unsuccessfully. The participants reported 167 pieces, some more often than others. Nine features of the pieces were analyzed using a combination of music information retrieval methods and aural analysis. Results: Of the pieces reported by participants, 78% were successful in aiding sleep. The features they had in common were that (a) their main frequency register was middle range frequencies; (b) their tempo was medium; (c) their articulation was legato; (d) they were in the major mode, and (e) lyrics were present. They differed from pieces that were unsuccessful in aiding sleep in that (a) their main frequency register was lower; (b) their articulation was legato, and (c) they excluded high rhythmic activity. Conclusion: Music that aids sleep is not necessarily sedative music, as defined in the literature, but some features of sedative music are associated with aiding sleep. In the present study, we identified the specific features of music that were reported to have been successful and unsuccessful in aiding sleep. The identification of these features has important implications for the selection of pieces of music used in research on sleep.

scholarly journals Advanced High Strength Steel in Auto Industry: an Overview

2014 ◽  
Vol 4 (4) ◽  
pp. 686-689 ◽  
Author(s):  
N. Baluch ◽  
Z. M. Udin ◽  
C. S. Abdullah
Keyword(s):  
Automotive Industry ◽  
High Strength Steel ◽  
Low Cost ◽  
High Strength ◽  
Direct Result ◽  
Advanced High Strength Steel ◽  
Geometrical Form ◽  
Cost Efficient ◽  
Safety Attributes ◽  
Selection Of

The world’s most common alloy, steel, is the material of choice when it comes to making products as diverse as oil rigs to cars and planes to skyscrapers, simply because of its functionality, adaptability, machine-ability and strength. Newly developed grades of Advanced High Strength Steel (AHSS) significantly outperform competing materials for current and future automotive applications. This is a direct result of steel’s performance flexibility, as well as of its many benefits including low cost, weight reduction capability, safety attributes, reduced greenhouse gas emissions and superior recyclability. To improve crash worthiness and fuel economy, the automotive industry is, increasingly, using AHSS. Today, and in the future, automotive manufacturers must reduce the overall weight of their cars. The most cost-efficient way to do this is with AHSS. However, there are several parameters that decide which of the AHSS types to be used; the most important parameters are derived from the geometrical form of the component and the selection of forming and blanking methods. This paper describes the different types of AHSS, highlights their advantages for use in auto metal stampings, and discusses about the new challenges faced by stampers, particularly those serving the automotive industry.

scholarly journals Opposing Influence of Sensory and Motor Cortical Input on Striatal Circuitry and Choice Behavior

2018 ◽  
Author(s):  
Christian R. Lee ◽  
Alex J. Yonk ◽  
Joost Wiskerke ◽  
Kenneth G. Paradiso ◽  
James M. Tepper ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Dorsal Striatum ◽  
Behavioral Effect ◽  
Projection Neurons ◽  
Cortical Input ◽  
Optogenetic Stimulation ◽  
Main Input ◽  
Opposing Effects ◽  
Stimulation Of

SummaryThe striatum is the main input nucleus of the basal ganglia and is a key site of sensorimotor integration. While the striatum receives extensive excitatory afferents from the cerebral cortex, the influence of different cortical areas on striatal circuitry and behavior is unknown. Here we find that corticostriatal inputs from whisker-related primary somatosensory (S1) and motor (M1) cortex differentially innervate projection neurons and interneurons in the dorsal striatum, and exert opposing effects on sensory-guided behavior. Optogenetic stimulation of S1-corticostriatal afferents in ex vivo recordings produced larger postsynaptic potentials in striatal parvalbumin (PV)-expressing interneurons than D1- or D2-expressing spiny projection neurons (SPNs), an effect not observed for M1-corticostriatal afferents. Critically, in vivo optogenetic stimulation of S1-corticostriatal afferents produced task-specific behavioral inhibition, which was bidirectionally modulated by striatal PV interneurons. Optogenetic stimulation of M1 afferents produced the opposite behavioral effect. Thus, our results suggest opposing roles for sensory and motor cortex in behavioral choice via distinct influences on striatal circuitry.

Nanomaterials and Nanocomposites Thermal and Mechanical Properties Modelling

2019 ◽  
pp. 234-256 ◽  
Author(s):  
Siddhartha Kosti
Keyword(s):  
Thermal Properties ◽  
Structural Properties ◽  
Base Material ◽  
High Strength ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Weight Percentage ◽  
Structural Applications ◽  
Glass Frp ◽  
Selection Of

This chapter deals with the modelling of nanomaterial and nanocomposite mechanical and thermal properties. Enrichment in the technology requires materials having higher thermal properties or higher structural properties. Nanomaterials and nanocomposites can serve this purpose accurately for aerospace or thermal applications and structural applications respectively. The thermal system requires materials having high thermal conductivity while structural system requires materials having high strength. Selection of the material for particular application is very critical and requires knowledge and experience. Al, Cu, TiO2, Al2O3, etc. are considered for thermal applications while epoxy-glass, FRP, etc. are considered for structural applications. Modelling of these nanomaterials and nanocomposites is done with the help of different mathematical models available in the literature. Results show that addition of the nanoparticle/composite in the base material can enhance the thermal and structural properties. Results also show that amount of weight percentage added also affects the properties.

Nanomaterials and Nanocomposites Thermal and Mechanical Properties Modelling

2021 ◽  
pp. 180-199
Author(s):  
Siddhartha Kosti
Keyword(s):  
Thermal Properties ◽  
Structural Properties ◽  
Base Material ◽  
High Strength ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Weight Percentage ◽  
Structural Applications ◽  
Glass Frp ◽  
Selection Of

This chapter deals with the modelling of nanomaterial and nanocomposite mechanical and thermal properties. Enrichment in the technology requires materials having higher thermal properties or higher structural properties. Nanomaterials and nanocomposites can serve this purpose accurately for aerospace or thermal applications and structural applications respectively. The thermal system requires materials having high thermal conductivity while structural system requires materials having high strength. Selection of the material for particular application is very critical and requires knowledge and experience. Al, Cu, TiO2, Al2O3, etc. are considered for thermal applications while epoxy-glass, FRP, etc. are considered for structural applications. Modelling of these nanomaterials and nanocomposites is done with the help of different mathematical models available in the literature. Results show that addition of the nanoparticle/composite in the base material can enhance the thermal and structural properties. Results also show that amount of weight percentage added also affects the properties.

An assessment into mechanical properties and microstructural behavior of TIG welded Ti-6Al-4V titanium alloy

2020 ◽  
Vol 10 (3) ◽  
pp. 281-292 ◽  
Author(s):  
Saurabh Dewangan ◽  
Suraj Kumar Mohapatra ◽  
Abhishek Sharma
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weight Ratio ◽  
High Strength ◽  
Hardness Test ◽  
Content Type ◽  
Ti Alloys ◽  
Microstructure And Mechanical Properties ◽  
Grade 5 ◽  
Selection Of

PurposeTitanium (Ti) alloys are in high demand in manufacturing industries all over the world. The property like high strength to weight ratio makes Ti alloys highly recommended for aerospace industries. Ti alloys possess good weldability, and therefore, they were extensively investigated with regard to strength and metallurgical properties of welded joint. This study aims to deal with the analysis of strength and microstructural changes in Ti-6Al-4V (Grade 5) alloy after tungsten inert gas (TIG) welding.Design/methodology/approachTwo pair of Ti alloy plates were welded in two different voltages, i.e. 24 and 28 V, with keeping the current constant, i.e. 80 A It was a random selection of current and voltage values to check the performance of welded material. Both the welded plates were undergone through some mechanical property analysis like impact test, tensile test and hardness test. In addition, the microstructure of the welded joints was also analyzed.FindingsIt was found that hardness and tensile properties gets improved with an increment in voltage, but this effect was reverse for impact toughness. A good corroboration between microstructure and mechanical properties, such as tensile strength, hardness and toughness, was reported in this work. Heat distribution in both the welded plates was simulated through ANSYS software to check the temperature contour in the plates.Originality/valueA good corroboration between microstructure and mechanical properties, such as tensile strength, hardness and toughness, was reported in this study.

Life Extending Advanced Component Repairs — Field Operating Experience

2000 ◽  
Author(s):  
Lloyd A. Cooke
Keyword(s):  
Powder Metallurgy ◽  
Gas Turbine ◽  
Operating Experience ◽  
High Strength ◽  
Operating Environment ◽  
Repair Materials ◽  
New Generation ◽  
Filler Metals ◽  
Selection Of ◽  
Repair Techniques

Advanced repair technologies have been introduced to the gas turbine industry over recent years. An increasing selection of coating systems is available which can be tailored to the specific operating environment. Automated welding systems and the use of custom weld filler metals for enhanced component life provide a means of reliably welding the new generation of high strength turbine blade alloys. Powder metallurgy processes have been introduced as an alternative to welding and have been used to upgrade certain components by employing higher strength repair materials than the original castings. In the paper, these and other technologies are assessed based on engine operating experience with direct comparison to the conventional repair techniques which they have replaced.

On the Materials Requirements for a Solar Solid-Expansion Machine

2000 ◽  
Vol 122 (3) ◽  
pp. 154-157
Author(s):  
B. J. Brinkworth
Keyword(s):  
Figure Of Merit ◽  
High Strength ◽  
Solar Thermal ◽  
Low Alloy Steels ◽  
Expansion Engine ◽  
Alloy Steels ◽  
Thermal Histories ◽  
Engineering Alloys ◽  
Selection Of

An outline is given of the mechanical and thermal histories of the working substance for a generic stand-alone solar thermal solid-expansion engine. A Figure-of-merit for the selection of materials is devised and evaluated, showing that high-strength engineering alloys figure best for this duty, with the carbon and low-alloy steels a practical choice. [S0199-6231(00)00403-2]

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