96 research outputs found
Analisa Kepuasan Konsumen Di Restaurant “X” Di Surabaya
Penelitian ini ditunjukan untuk menganalisa tingkat kesenjangan antara harapan dari konsumen terhadap Kenyataan yang diterima oleh konsumen dan mengukur tingkat kepuasan konsumen di Restoran “X” dengan menggunakan atribut DINESERV. Penelitian ini menggunakan Importance Performance Analysis(IPA). Hasil dari penelitian ini adalah kesenjangan antara harapan dan Kenyataan yang diukur menggunakan atribut DINESERV adalah Kenyataan yang diterima oleh konsumen sangat tidak sesuai dengan harapan konsumen dan konsumen sangat tidak puas terutama dengan atribut Convenience Restoran yaitu Jarak dari Restoran “X” di Surabay
Molecular Dynamics Simulations with Quantum Mechanics/Molecular Mechanics and Adaptive Neural Networks
Direct
molecular dynamics (MD) simulation with ab initio quantum mechanical
and molecular mechanical (QM/MM) methods is very powerful for studying
the mechanism of chemical reactions in a complex environment but also
very time-consuming. The computational cost of QM/MM calculations
during MD simulations can be reduced significantly using semiempirical
QM/MM methods with lower accuracy. To achieve higher accuracy at the
ab initio QM/MM level, a correction on the existing semiempirical
QM/MM model is an attractive idea. Recently, we reported a neural
network (NN) method as QM/MM-NN to predict the potential energy difference
between semiempirical and ab initio QM/MM approaches. The high-level
results can be obtained using neural network based on semiempirical
QM/MM MD simulations, but the lack of direct MD samplings at the ab
initio QM/MM level is still a deficiency that limits the applications
of QM/MM-NN. In the present paper, we developed a dynamic scheme of
QM/MM-NN for direct MD simulations on the NN-predicted potential energy
surface to approximate ab initio QM/MM MD. Since some configurations
excluded from the database for NN training were encountered during
simulations, which may cause some difficulties on MD samplings, an
adaptive procedure inspired by the selection scheme reported by Behler
[Behler Int. J. Quantum Chem. 2015, 115, 1032; Behler Angew. Chem., Int. Ed. 2017, 56, 12828] was employed with some adaptions to update
NN and carry out MD iteratively. We further applied the adaptive QM/MM-NN
MD method to the free energy calculation and transition path optimization
on chemical reactions in water. The results at the ab initio QM/MM
level can be well reproduced using this method after 2–4 iteration
cycles. The saving in computational cost is about 2 orders of magnitude.
It demonstrates that the QM/MM-NN with direct MD simulations has great
potentials not only for the calculation of thermodynamic properties
but also for the characterization of reaction dynamics, which provides
a useful tool to study chemical or biochemical systems in solution
or enzymes
Quantum Mechanics/Molecular Mechanics Method Combined with Hybrid All-Atom and Coarse-Grained Model: Theory and Application on Redox Potential Calculations
We
developed a new multiresolution method that spans three levels
of resolution with quantum mechanical, atomistic molecular mechanical,
and coarse-grained models. The resolution-adapted all-atom and coarse-grained
water model, in which an all-atom structural description of the entire
system is maintained during the simulations, is combined with the
ab initio quantum mechanics and molecular mechanics method. We apply
this model to calculate the redox potentials of the aqueous ruthenium
and iron complexes by using the fractional number of electrons approach
and thermodynamic integration simulations. The redox potentials are
recovered in excellent accordance with the experimental data. The
speed-up of the hybrid all-atom and coarse-grained water model renders
it computationally more attractive. The accuracy depends on the hybrid
all-atom and coarse-grained water model used in the combined quantum
mechanical and molecular mechanical method. We have used another multiresolution
model, in which an atomic-level layer of water molecules around redox
center is solvated in supramolecular coarse-grained waters for the
redox potential calculations. Compared with the experimental data,
this alternative multilayer model leads to less accurate results when
used with the coarse-grained polarizable MARTINI water or big multipole
water model for the coarse-grained layer
Resolution-Adapted All-Atomic and Coarse-Grained Model for Biomolecular Simulations
We develop here an adaptive multiresolution
method for the simulation
of complex heterogeneous systems such as the protein molecules. The
target molecular system is described with the atomistic structure
while maintaining concurrently a mapping to the coarse-grained models.
The theoretical model, or force field, used to describe the interactions
between two sites is automatically adjusted in the simulation processes
according to the interaction distance/strength. Therefore, all-atomic,
coarse-grained, or mixed all-atomic and coarse-grained models would
be used together to describe the interactions between a group of atoms
and its surroundings. Because the choice of theory is made on the
force field level while the sampling is always carried out in the
atomic space, the new adaptive method preserves naturally the atomic
structure and thermodynamic properties of the entire system throughout
the simulation processes. The new method will be very useful in many
biomolecular simulations where atomistic details are critically needed
Detailed characteristics of all eligible studies for the association with TGF gene polymorphisms and PE.
<p>*Genotype for 869 T>C, TT/TC/CC; 915 G>C, GG/GC/CC; 800 G>A, GG/GA/AA; 509 C>T, CC/CT/TT.</p>a<p>Significant differences was found in allelic frequencies between preeclamptic and control groups.</p>b<p>No significant differences was found in allelic frequencies between preeclamptic and control groups.</p
Thermodynamic properties of solvated peptides from selective integrated tempering sampling with a new weighting factor estimation algorithm
<p>Conformational sampling under rugged energy landscape is always a challenge in computer simulations. The recently developed integrated tempering sampling, together with its selective variant (SITS), emerges to be a powerful tool in exploring the free energy landscape or functional motions of various systems. The estimation of weighting factors constitutes a critical step in these methods and requires accurate calculation of partition function ratio between different thermodynamic states. In this work, we propose a new adaptive update algorithm to compute the weighting factors based on the weighted histogram analysis method (WHAM). The adaptive-WHAM algorithm with SITS is then applied to study the thermodynamic properties of several representative peptide systems solvated in an explicit water box. The performance of the new algorithm is validated in simulations of these solvated peptide systems. We anticipate more applications of this coupled optimisation and production algorithm to other complicated systems such as the biochemical reactions in solution.</p
(Top) RTs for painful stimuli (left) and non-painful stimuli (right) in auditory tasks; (Bottom) RTs for painful stimuli (left) and non-painful stimuli (right) in visual tasks.
<p>Data are presented as mean values (more details see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174109#pone.0174109.s004" target="_blank">S1 Table</a>). Error bars represent standard error of the mean. Significant effect at p< 0.01 is marked by two asterisks.</p
Responses to others’ pain in adults with autistic traits: The influence of gender and stimuli modality
<div><p>Individuals with autism-spectrum disorder (ASD) exhibit impairments in response to others’ pain. Evidence suggests that features of autism are not restricted to individuals with ASD, and that autistic traits vary throughout the general population. To investigate the association between autistic traits and the responses to others’ pain in typically developing adults, we employed the Autism-Spectrum Quotient (AQ) to quantify autistic traits in a group of 1670 healthy adults and explored whether 60 participants (30 males and 30 females) with 10% highest AQ scores (High-AQ) would exhibit difficulties in the responses to others’ pain relative to 60 participants (30 males and 30 females) with 10% lowest AQ scores (Low-AQ). This study included a Visual Task and an Auditory Task to test behavioral differences between High-AQ and Low-AQ groups’ responses to others’ pain in both modalities. For the Visual Task, participants were instructed to respond to pictures depicting others’ pain. They were instructed to judge the stimuli type (painful or not), judge others’ pain intensity, and indicate the unpleasantness they personally felt. For the Auditory Task, experimental procedures were identical to the Visual Task except that painful voices were added. Results showed the High-AQ group was less accurate than the Low-AQ group in judging others’ pain. Moreover, relative to Low-AQ males, High-AQ males had significantly longer reaction times in judging others’ pain in the Auditory Task. However, High-AQ and Low-AQ females showed similar reaction times in both tasks. These findings demonstrated identification of others’ pain by healthy adults is related to the extent of autistic traits, gender, and modality.</p></div
Polymorphisms and Plasma Level of Transforming Growth Factor-Beta 1 and Risk for Preeclampsia: A Systematic Review
<div><p>Background</p><p>Transforming growth factor-beta 1 (TGF-β1) is thought to be involved in the pathogenesis of preeclampsia (PE), but the results are inconsistent among studies. This article aims to compile an overview of the studies about the associations of TGF-β 1 polymorphism and plasma level with PE risk and to provide recommendations for future research.</p><p>Methods and Results</p><p>The databases PubMed, Embase and Web of Science were searched up to December 2013. Five studies investigating the associations of four polymorphisms with the risks of PE were involved. A meta-analysis was conducted for the 869T>C polymorphism and PE risk. The results show that genotype TT of 869T>C polymorphism is a protective factor of PE (pooled odds ratio = 0.73, 95% CI: 0.56, 0.95). Eight case-control studies reported the plasma level of TGF-β 1. The substantial heterogeneity among studies may be attributed to the differences in the blood sample processing and the TGF-β 1 analysis kits. The results suggest that plasma TGF-β 1 level in the second trimester was significantly lower in the PE group than in the normal pregnancy group, but was significantly higher in the PE group during the third trimester.</p><p>Conclusions</p><p>The current results support that the TGF-β 1 869 T>C polymorphism was associated with the risk of PE. However, the number of eligible studies is small and more studies are needed to clarify whether this association can be detected on larger sample sizes and different populations. Owing to the heterogeneity between studies, no conclusion on the association between plasma TGF-β 1 level and PE risk can be drawn from this review. Further studies about the TGF-β 1 levels at different stages of pregnancy and the development of TGF-β 1 assay methodology are required to reveal the role of TGF-β 1 in the pathological development of PE.</p></div
PRISMA flow diagram of study selection process (a) articles involving TGF-beta 1 genetic variants and (b) articles involving plasma concentration of TGF-beta1.
<p>PRISMA flow diagram of study selection process (a) articles involving TGF-beta 1 genetic variants and (b) articles involving plasma concentration of TGF-beta1.</p
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