1,729 research outputs found
ПРОБЛЕМИ ФОРМУВАННЯ ЕФЕКТИВНОГО ІМІДЖУ В СУЧАСНІЙ ПОЛІТОЛОГІЇ
Проаналізовані поняття та структура політичного іміджу, визначені компоненти
ефективного іміджу політика, виділені складові елементи та закономірності побудови сучасної
іміджевої стратегії.Analyzed the concept and structure of political image, the image identified components of effective
policy, special elements and patterns of modern image strategy
Combination treatment with cold physical plasma and pulsed electric fields augments ros production and cytotoxicity in lymphoma
New approaches in oncotherapy rely on the combination of different treatments to enhance the efficacy of established monotherapies. Pulsed electric fields (PEFs) are an established method (electrochemotherapy) for enhancing cellular drug uptake while cold physical plasma is an emerging and promising anticancer technology. This study aimed to combine both technologies to elucidate their cytotoxic potential as well as the underlying mechanisms of the effects observed. An electric field generator (0.9–1.0 kV/cm and 100-μs pulse duration) and an atmospheric pressure argon plasma jet were employed for the treatment of lymphoma cell lines as a model system. PEF but not plasma treatment induced cell membrane permeabilization. Additive cytotoxicity was observed for the metabolic activity and viability of the cells while the sequence of treatment in the combination played only a minor role. Intriguingly, a parallel combination was more effective compared to a 15-min pause between both treatment regimens. A combination effect was also found for lipid peroxidation; however, none could be observed in the cytosolic and mitochondrial reactive oxygen species (ROS) production. The supplementation with either antioxidant, a pan-caspase-inhibitor or a ferroptosis inhibitor, all partially rescued lymphoma cells from terminal cell death, which contributes to the mechanistic understanding of this combination treatment. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Cluster update and recognition
We present a fast and robust cluster update algorithm that is especially
efficient in implementing the task of image segmentation using the method of
superparamagnetic clustering. We apply it to a Potts model with spin
interactions that are are defined by gray-scale differences within the image.
Motivated by biological systems, we introduce the concept of neural inhibition
to the Potts model realization of the segmentation problem. Including the
inhibition term in the Hamiltonian results in enhanced contrast and thereby
significantly improves segmentation quality. As a second benefit we can - after
equilibration - directly identify the image segments as the clusters formed by
the clustering algorithm. To construct a new spin configuration the algorithm
performs the standard steps of (1) forming clusters and of (2) updating the
spins in a cluster simultaneously. As opposed to standard algorithms, however,
we share the interaction energy between the two steps. Thus the update
probabilities are not independent of the interaction energies. As a
consequence, we observe an acceleration of the relaxation by a factor of 10
compared to the Swendson and Wang procedure.Comment: 4 pages, 2 figure
Psychology as a natural science in the eighteenth century
Psychology considered as a natural science began as Aristotelian "physics" or "natural philosophy" of the soul. C. Wolff placed psychology under metaphysics, coordinate with cosmology. Scottish thinkers placed it within moral philosophy, but distinguished its "physical" laws from properly moral laws (for guiding conduct). Several Germans sought to establish an autonomous empirical psychology as a branch of natural science. British and French visual theorists developed mathematically precise theories of size and distance perception; they created instruments to test these theories and to measure visual phenomena such as the duration of visual impressions. These investigators typically were dualists who included mental phenomena within nature
Infrared behavior of the gluon propagator in lattice Landau gauge: the three-dimensional case
We evaluate numerically the three-momentum-space gluon propagator in the
lattice Landau gauge, for three-dimensional pure-SU(2) lattice gauge theory
with periodic boundary conditions. Simulations are done for nine different
values of the coupling , from (strong coupling) to (in the scaling region), and for lattice sizes up to . In the
limit of large lattice volume we observe, in all cases, a gluon propagator
decreasing for momenta smaller than a constant value . From our data
we estimate MeV. The result of a gluon propagator
decreasing in the infrared limit has a straightforward interpretation as
resulting from the proximity of the so-called first Gribov horizon in the
infrared directions.Comment: 14 pages, BI-TP 99/03 preprint, correction in the Acknowledgments
section. To appear in Phys.Rev.
Comparison of CT, MRI, and F-18 FDG PET/CT for initial N-staging of oral squamous cell carcinoma: a cost-effectiveness analysis.
BACKGROUND AND PURPOSE
Treatment of oral squamous cell carcinoma (OSCC) is based on clinical exam, biopsy, and a precise imaging-based TNM-evaluation. A high sensitivity and specificity for magnetic resonance imaging (MRI) and F-18 FDG PET/CT are reported for N-staging. Nevertheless, staging of oral squamous cell carcinoma is most often based on computed tomography (CT) scans. This study aims to evaluate cost-effectiveness of MRI and PET/CT compared to standard of care imaging in initial staging of OSCC within the US Healthcare System.
METHODS
A decision model was constructed using quality-adjusted life years (QALYs) and overall costs of different imaging strategies including a CT of the head, neck, and the thorax, MRI of the neck with CT of the thorax, and whole body F-18 FDG PET/CT using Markov transition simulations for different disease states. Input parameters were derived from literature and willingness to pay (WTP) was set to US 239,628 for CT, US 239,131 for F-18 FDG PET/CT whereas the model yielded an effectiveness of 5.29 QALYs for CT, 5.30 QALYs for MRI, and 5.32 QALYs for F-18 FDG PET/CT respectively. F-18 FDG PET/CT was the most cost-effective strategy over MRI as well as CT, and MRI was the cost-effective strategy over CT. Deterministic and probabilistic sensitivity analysis showed high robustness of the model with incremental cost effectiveness ratio remaining below US $100,000/QALY for a wide range of variability of input parameters.
CONCLUSION
F-18 FDG PET/CT is the most cost-effective strategy in the initial N-staging of OSCC when compared to MRI and CT. Despite less routine use, both whole body PET/CT and MRI are cost-effective modalities in the N-staging of OSCC. Based on these findings, the implementation of PET/CT for initial staging could be suggested to help reduce costs while increasing effectiveness in OSCC
Rotational velocities of A-type stars I. Measurement of vsini in the southern hemisphere
Within the scope of a Key Programme determining fundamental parameters of
stars observed by HIPPARCOS, spectra of 525 B8 to F2-type stars brighter than
V=8 have been collected at ESO. Fourier transforms of several line profiles in
the range 4200-4500 A are used to derive vsini from the frequency of the first
zero. Statistical analysis of the sample indicates that measurement error is a
function of vsini and this relative error of the rotational velocity is found
to be about 6% on average. The results obtained are compared with data from the
literature. There is a systematic shift from standard values from Slettebak et
al. (1975), which are 10 to 12% lower than our findings. Comparisons with other
independent vsini values tend to prove that those from Slettebak et al. are
underestimated. This effect is attributed to the presence of binaries in the
standard sample of Slettebak et al., and to the model atmosphere they used.Comment: 17 pages, includes 18 figures, accepted in A&
The Precipitation Imaging Package : Assessment of Microphysical and Bulk Characteristics of Snow
Remote-sensing observations are needed to estimate the regional and global impacts of snow. However, to retrieve accurate estimates of snow mass and rate, these observations require augmentation through additional information and assumptions about hydrometeor properties. The Precipitation Imaging Package (PIP) provides information about precipitation characteristics and can be utilized to improve estimates of snowfall rate and accumulation. Here, the goal is to demonstrate the quality and utility of two higher-order PIP-derived products: liquid water equivalent snow rate and an approximation of volume-weighted density called equivalent density. Accuracy of the PIP snow rate and equivalent density is obtained through intercomparison with established retrieval methods and through evaluation with colocated ground-based observations. The results confirm the ability of the PIP-derived products to quantify properties of snow rate and equivalent density, and demonstrate that the PIP produces physically realistic snow characteristics. When compared to the National Weather Service (NWS) snow field measurements of six-hourly accumulation, the PIP-derived accumulations were biased only +2.48% higher. Additionally, this work illustrates fundamentally different microphysical and bulk features of low and high snow-to-liquid ratio events, through assessment of observed particle size distributions, retrieved mass coefficients, and bulk properties. Importantly, this research establishes the role that PIP observations and higher-order products can serve for constraining microphysical assumptions in ground-based and spaceborne remotely sensed snowfall retrievals.Peer reviewe
SU(2) Landau gluon propagator on a 140^3 lattice
We present a numerical study of the gluon propagator in lattice Landau gauge
for three-dimensional pure-SU(2) lattice gauge theory at couplings beta = 4.2,
5.0, 6.0 and for lattice volumes V = 40^3, 80^3, 140^3. In the limit of large V
we observe a decreasing gluon propagator for momenta smaller than p_{dec} =
350^{+ 100}_{- 50} MeV. Data are well fitted by Gribov-like formulae and seem
to indicate an infra-red critical exponent kappa slightly above 0.6, in
agreement with recent analytic results.Comment: 5 pages with 2 figures and 3 tables; added a paragraph on
discretization effect
The Computational Complexity of Generating Random Fractals
In this paper we examine a number of models that generate random fractals.
The models are studied using the tools of computational complexity theory from
the perspective of parallel computation. Diffusion limited aggregation and
several widely used algorithms for equilibrating the Ising model are shown to
be highly sequential; it is unlikely they can be simulated efficiently in
parallel. This is in contrast to Mandelbrot percolation that can be simulated
in constant parallel time. Our research helps shed light on the intrinsic
complexity of these models relative to each other and to different growth
processes that have been recently studied using complexity theory. In addition,
the results may serve as a guide to simulation physics.Comment: 28 pages, LATEX, 8 Postscript figures available from
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