576 research outputs found
The influence of cisplatin on transcriptional profile of tumor-associated macrophages of breast cancer and colon cancer
In the present study we demonstrated the whole transcriptome analysis of model tumor-associate
Analysis of negative magnetoresistance. Statistics of closed paths. I. Theory
Statistics of closed paths in two-dimensional (2D) systems, which just
determines the interference quantum correction to conductivity and anomalous
magnetoconductance, has been studied by computer simulation of a particle
motion over the plane with randomly distributed scatterers. Both ballistic and
diffusion regimes have been considered. The results of simulation have been
analyzed in the framework of diffusion approximation. They are used for
calculation of the magnetic field dependence of magnetoconductance in the model
2D system. It is shown that the anomalous magnetoconductance can be in
principle described by the well known expression, obtained in the diffusion
approximation, but with the prefactor less than unity and phase breaking length
which differs from true value.Comment: 10 pages, 12 figures, to be published in Phys.Rev.
The Outburst of the Blazar AO 0235+164 in 2006 December: Shock-in-Jet Interpretation
We present the results of polarimetric ( band) and multicolor photometric
() observations of the blazar AO 0235+16 during an outburst in 2006
December. The data reveal a short timescale of variability (several hours),
which increases from optical to near-IR wavelengths; even shorter variations
are detected in polarization. The flux density correlates with the degree of
polarization, and at maximum degree of polarization the electric vector tends
to align with the parsec-scale jet direction. We find that a variable component
with a steady power-law spectral energy distribution and very high optical
polarization (30-50%) is responsible for the variability. We interpret these
properties of the blazar withina model of a transverse shock propagating down
the jet. In this case a small change in the viewing angle of the jet, by
, and a decrease in the shocked plasma compression by a factor of
1.5 are sufficient to account for the variability.Comment: 22 pages, 8 figures, accepted for Ap
Economic Aspects of Emergency Transition to Distance Education, or The Price of Going Online in Higher Education
As Russian universities switched to distance education in March 2020 to prevent COVID-19 from spreading, self‑paying students started questioning the fairness of tuition fees during the pandemic. They fled petitions, emphasizing that distance learning could not be equated to traditional classroom‑based learning, that educational services were not delivered to the full extent, and that educational quality had decreased. On those grounds, students required cutting tuition fees down to the size of those in part‑time or extramural education. To understand whether universities can afford making this step, we undertake to measure the price that they have paid for the transition to distance learning. For this purpose, we use data from a survey of faculty teaching and curriculum organization practices carried out at a federal university between March 23, 2020 and June 21, 2020, which involved 4,099 faculty members, as well as financial records of some departments within that university. Findings show that teaching workload reduced by 15% with distance learning during the pandemic, and the number of contact hours decreased 1.7 times. However, the overall amount of faculty workload increased by 50%, first of all due to a 2.4-time rise in curriculum organization activities. Therefore, the transition to distance education led to a significant increase in faculty workload, given that contact hours were preserved. Furthermore, the university invested heavily in the transition to distance learning and continuity of educational processes during the pandemic, in particular by financing the establishment of a new department for digitalization of learning processes. An inference is made that distance education imposed by the pandemic has not been reduced to part‑time or extramural studies. Decisions about cutting tuition fees for self‑paying students should be made at the institutional level, with due regard for faculty workload and digitization costs. © 202
Diffusion and ballistic contributions of the interaction correction to the conductivity of a two-dimensional electron gas
The results of an experimental study of interaction quantum correction to the
conductivity of two-dimensional electron gas in AB semiconductor
quantum well heterostructures are presented for a wide range of
-parameter (), where is the transport
relaxation time. A comprehensive analysis of the magnetic field and temperature
dependences of the resistivity and the conductivity tensor components allows us
to separate the ballistic and diffusion parts of the correction. It is shown
that the ballistic part renormalizes in the main the electron mobility, whereas
the diffusion part contributes to the diagonal and does not to the off-diagonal
component of the conductivity tensor. We have experimentally found the values
of the Fermi-liquid parameters describing the electron-electron contribution to
the transport coefficients, which are found in a good agreement with the
theoretical results.Comment: 11 pages, 11 figure
Risk Assessment at the Cosmetic Product Manufacturer by Expert Judgment Method
A case study was performed in a cosmetic product manufacturer. We have identified the main risk factors of occupational accidents and their causes. Risk of accidents is assessed by the expert judgment method. Event tree for the most probable accident is built and recommendations on improvement of occupational health and safety protection system at the cosmetic product manufacturer are developed. The results of this paper can be used to develop actions to improve the occupational safety and health system in the chemical industry
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