Search results for "Function"

Nanohybrid surface based on covalent linkage of amino-functionalized silica nanoparticles on EAA polymeric substrate

2011

Narratives of children with high-functioning autism spectrum disorder: A meta-analysis

2016

Abstract Background The aim of this meta-analysis was to analyze the narrative performance of children and adolescents with high-functioning Autism Spectrum Disorders (ASD) in terms of microstructure, macrostructure and internal state language. Method A systematic literature search yielded 24 studies that met the predetermined inclusion criteria. Effect sizes for each study were calculated for eight variables and analyzed using a random effects model. Intellectual ability, age and type of narrative were considered as potential moderators. Results Results revealed that the children with ASD performed significantly worse than their peers on all the variables considered. Conclusions Findings a…

Spēles naratīva analīze: “Half Life” franšīze

2022

Pētījuma galvenais mērķis ir atklāt, kā stāstījumu tehnikas pielietotas video spēļu franšīzē Half-Life. Pētījumam izvēlētas četras franšīzes Half-Life un Half-Life 2 spēles. Teorētiskajā daļā tika apskatīts, kā stāstījumu jēdzieni ir pielāgojami video spēļu pētījumam. Izvēlēto video spēļu analīze parādīja, ka stāstījumu izteiksmes līdzekļi un struktūras var tikt pielietotas arī izvēlētajām video spēlēm, dažām no tām stingri neievērojot avotu teorētiskos ierobežojumus. Pētījuma rezultāti nodrošina plašāku video spēļu stāstījumu izpētes iespējas.

Comparison of different theory models and basis sets in the calculation of 13C NMR chemical shifts of natural products.

2004

The influence of the calculation method in mimicking experimental 13C NMR chemical shifts of 15 low-polarity natural products singularly containing 10–20 carbon atoms was investigated by employing different quantum chemistry approaches and basis sets, both in the preliminary geometry optimizations and in the following single-point 13C GIAO calculations of the NMR chemical shifts. The geometries of the involved species were optimized at the PM3, HF, B3LYP and mPW1PW91 levels whereas the 13C NMR parameters were determined at the HF, B3LYP and mPW1PW91 levels. Different combinations of basis sets were also tested. The consistency and efficiency of the considered combinations of geometry optimi…

Four-Component Relativistic DFT Calculations of C-13 Chemical Shifts of Halogenated Natural Substances

2015

We have calculated the (13) C NMR chemical shifts of a large ensemble of halogenated organic molecules (81 molecules for a total of 250 experimental (13) C NMR data at four different levels of theory), ranging from small rigid organic compounds, used to benchmark the performance of various levels of theory, to natural substances of marine origin with conformational degrees of freedom. Carbon atoms bonded to heavy halogen atoms, particularly bromine and iodine, are known to be rather challenging when it comes to the prediction of their chemical shifts by quantum methods, due to relativistic effects. In this paper, we have applied the state-of-the-art four-component relativistic density funct…

Medicinal and aromatic plants in agricultural research, when considering criteria of multifunctionality and sustainability

2022

Over the last twenty years, agriculture has witnessed significant changes in terms of energy requirements, advanced technologies and practices. This is in response to the impacts of crop production on the climate and environment and increasing awareness of the importance of agricultural sustainability through organic farming. Agriculture encompasses complex production systems and certain aspects of multifunctionality and sustainability have become fundamental for these systems. Agricultural activity can provide various functions in agro-ecosystems, such as producing food, managing natural resources, and conserving landscape and plant biodiversity; contributing to the cultural, historical an…

A Catalyst Designed for the Enantioselective Construction of Methyl- and Alkyl-Substituted Tertiary Stereocenters

2015

Tertiary methyl-substituted stereocenters are present in numerous biologically active natural products. Reported herein is a catalytic enantioselective method for accessing these chiral building blocks using the Mukaiyama-Michael reaction between silyl ketene thioacetals and acrolein. To enable remote enantioface control on the nucleophile, a new iminium catalyst, optimized by three-parameter tuning and by identifying substituent effects on enantioselectivity, was designed. The catalytic process allows rapid access to chiral thioesters, amides, aldehydes, and ketones bearing an α-methyl stereocenter with excellent enantioselectivities, and allowed rapid access to the C4-C13 segment of (-)-b…

Blends of Semiflexible Polymers: Interplay of Nematic Order and Phase Separation

2021

Mixtures of semiflexible polymers with a mismatch in either their persistence lengths or their contour lengths are studied by Density Functional Theory and Molecular Dynamics simulation. Considering lyotropic solutions under good solvent conditions, the mole fraction and pressure is systematically varied for several cases of bending stiffness κ (the normalized persistence length) and chain length N. For binary mixtures with different chain length (i.e., NA=16, NB=32 or 64) but the same stiffness, isotropic-nematic phase coexistence is studied. For mixtures with the same chain length (N=32) and large stiffness disparity (κB/κA=4.9 to 8), both isotropic-nematic and nematic-nematic unmixing oc…

Hyper-flexible Convolutional Neural Networks based on Generalized Lehmer and Power Means

2022

Convolutional Neural Network is one of the famous members of the deep learning family of neural network architectures, which is used for many purposes, including image classification. In spite of the wide adoption, such networks are known to be highly tuned to the training data (samples representing a particular problem), and they are poorly reusable to address new problems. One way to change this would be, in addition to trainable weights, to apply trainable parameters of the mathematical functions, which simulate various neural computations within such networks. In this way, we may distinguish between the narrowly focused task-specific parameters (weights) and more generic capability-spec…

Transcranial Magnetic Stimulation and Neuroimaging Coregistration

2013

The development of neuroimaging techniques is one of the most impressive advancements in neuroscience. The main reason for the widespread use of these instruments lies in their capacity to provide an accurate description of neural activity during a cognitive process or during rest. This important advancement is related to the possibility to selectively detect changes of neuronal activity in space and time by means of different biological markers. Specifically, functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and nearinfrared spectroscopy (NIRS) use metabolic markers of ongoing neuronal activity to provide a…