2,588 research outputs found
Robustness analysis of signaling transduction networks based on Monte-Carlo method
The dynamic behaviors of cell system were deep ly affected by structural complexity of cell signal transduction networks and uncertainty of kinetics parameters. How to quantitatively determinate the relation between system behaviors and parameters variations was an important p roblem of systems biology. In order to study robustness of NF - κB signal transduction networks, the parameters of system model were assigned to subject to stochastic distributions. Then, robustness of system output signal NF - κBn with respect to 64 parameters variations and amp litude variation of step input signal IKK was studied by means of Monte - Carlo method. The simulation results demonstrate that the oscillation behavior of system output signal NF - κBn is closely relative to 6 key rate constantswhose robustness isweak, and the amp litude variation of step input signal IKKmakes a great impact on the oscillation behavior of system output
Viral vector platforms within the gene therapy landscape
Throughout its 40-year history, the field of gene therapy has been marked by many transitions. It has seen great strides in combating human disease, has given hope to patients and families with limited treatment options, but has also been subject to many setbacks. Treatment of patients with this class of investigational drugs has resulted in severe adverse effects and, even in rare cases, death. At the heart of this dichotomous field are the viral-based vectors, the delivery vehicles that have allowed researchers and clinicians to develop powerful drug platforms, and have radically changed the face of medicine. Within the past 5 years, the gene therapy field has seen a wave of drugs based on viral vectors that have gained regulatory approval that come in a variety of designs and purposes. These modalities range from vector-based cancer therapies, to treating monogenic diseases with life-altering outcomes. At present, the three key vector strategies are based on adenoviruses, adeno-associated viruses, and lentiviruses. They have led the way in preclinical and clinical successes in the past two decades. However, despite these successes, many challenges still limit these approaches from attaining their full potential. To review the viral vector-based gene therapy landscape, we focus on these three highly regarded vector platforms and describe mechanisms of action and their roles in treating human disease
Shot noise of a multiwalled carbon nanotube field effect transistor
We have investigated shot noise in a 6−nm-diameter, semiconducting multiwalled carbon nanotube field effect transistor at 4.2 K over the frequency range of 600–950 MHz. We find a transconductance of 3–3.5 μS for optimal positive and negative source-drain voltages V. For the gate referred input voltage noise, we obtain 0.2 and 0.3 μV/√Hz for V > 0 and V < 0, respectively. As effective charge noise, this corresponds to (2–3)×10 exp −5 e/√Hz.Peer reviewe
Higgs boson decays to meson in the fragmentation-function approach
In the paper, we present a calculation of the decay widths for the Higgs
boson decays to the , , and mesons
using the fragmentation-function approach. In the calculation, the
fragmentation functions up to order based on the nonrelativistic
QCD factorization theory are used, and the decay widths for and at the partonic level are calculated up to order . The large
logarithms of are resummed up to next-to-leading logarithmic
accuracy by solving the evolution equations for the running quark masses and
the fragmentation functions. Compared to the leading-order decay widths based
on the nonrelativistic QCD approach, the decay widths based on the
fragmentation-function approach that include the higher-order QCD corrections
are reduced significantly. Our numerical results show that there are about
events via the Higgs decays to be produced at the HL-LHC
with , and about events via the Higgs decays
to be produced at the HE-LHC with .Comment: 12 pages, 9 figure
Price Limits and Stock Market Volatility in China
This paper explores the effects of price limits on the stock market of China during global market turmoils. The characteristics of stocks that hit the price limits more frequently under market turmoil are investigated. It is found that the price limit system increases volatility significantly during the downward price movement. Moreover, price limit delays the efficient price discovery for upward and downward price movements. Finally, actively-traded stocks with a higher positive correlation with the entire market in the property industry hit the price limits more frequently
A large calcium-imaging dataset reveals a systematic V4 organization for natural scenes
The visual system evolved to process natural scenes, yet most of our
understanding of the topology and function of visual cortex derives from
studies using artificial stimuli. To gain deeper insights into visual
processing of natural scenes, we utilized widefield calcium-imaging of primate
V4 in response to many natural images, generating a large dataset of
columnar-scale responses. We used this dataset to build a digital twin of V4
via deep learning, generating a detailed topographical map of natural image
preferences at each cortical position. The map revealed clustered functional
domains for specific classes of natural image features. These ranged from
surface-related attributes like color and texture to shape-related features
such as edges, curvature, and facial features. We validated the model-predicted
domains with additional widefield calcium-imaging and single-cell resolution
two-photon imaging. Our study illuminates the detailed topological organization
and neural codes in V4 that represent natural scenes.Comment: 39 pages, 14 figure
Statistical Analysis of High-Resolution Coherent Monopulse Radar Sea Clutter
A statistical analysis that properly characterizes sea clutter processes is indispensable both for optimum detection algorithm design and for performance prediction problems in maritime surveillance applications. In this paper, we present the statistical analysis of experimental sea clutter data collected by a high-resolution coherent monopulse radar. First, we present the amplitude statistical analyses for these clutter data. The results show that the K, Pareto, and CIG distributions can each provide good fits to the clutter data for three channels of monopulse radar. The analyses on the variations of the K distribution parameters with range suggest that the scale parameter is closely associated with the clutter powers and that the shape parameter is influenced by the sea state. Then, we focus on the correlation properties. The averaged results suggest that the temporal and spatial correlation properties are similar for the clutter of all three channels. Moreover, the clutter between the sum and difference channels is almost completely correlated in elevation and is lowly correlated in azimuth. Finally, we perform a spectral analysis, highlighting the temporal and spatial variabilities of Doppler spectra. It is found that the individual Doppler spectra in all three channels can be represented by Gaussian-shaped power spectral densities, and their centroid and width can be modeled as two separate stage linear functions of spectrum intensity
Introductory Notes to Algebraic Statistics
These are the notes of a short course on algebraic
statistics, a new discipline across the fields of statistical modeling
and computational commutativa algebra. The basics of the
theory are provided together with brief reference to applications to
design of experiments, to exponential and graphical models, and
to computational biology
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