Publications by authors named "Mikhail Alexandrov"

Background: Сervicomedullary ependymoma (CME) is a rare tumor of the central nervous system. The CME treatment strategy is insufficiently represented in the literature and is a complex task for neurosurgeons.

Observations: The authors describe an infrequent case of a large multisegmental CME that extended from the medulla oblongata to the cervical spinal cord at the level of the sixth cervical vertebra in a 21-year-old female.

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Background: Chronic cerebral ischemia (CCI) is a form of cerebrovascular disease manifested as a vascular cognitive impairment (VCI). The management of the patients with CCI is determined by a healthy lifestyle and early therapy aimed at correcting and preventing this disease. Divaza is a drug with endothelial protective and nootropic effects.

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The Research Scanning Polarimeter (RSP) is an airborne along-track scanner measuring the polarized and total reflectances with high angular resolution. It allows for accurate characterization of liquid water cloud droplet sizes using the rainbow structure in the polarized reflectance. RSP's observations also provide constraints on the cumulus cloud's 2D cross section, yielding estimates of its geometric shape.

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Article Synopsis
  • The cloud droplet number concentration (N) is crucial for understanding cloud physics and aerosol-cloud interactions, but current satellite methods to retrieve N are limited and uncertain.
  • A review highlights a total relative uncertainty of 78% in pixel-level retrievals for specific cloud types, which decreases to 54% for larger area averages, but accuracy against in situ observations is better than indicated by retrievals.
  • Dominant errors in retrieving N stem from inaccuracies in cloud droplet effective radius (r), and improving these retrievals is essential; the review also suggests recommendations and explores new methods for better N estimates using both satellite and ground-based data.
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We present, for the first time, a quantitative retrieval error-propagation study for a bistatic high spectral resolution lidar (HSRL) system intended for detailed quasi-global monitoring of aerosol properties from space. Our results demonstrate that supplementing a conventional monostatic HSRL with an additional receiver flown in formation at a scattering angle close to 165° dramatically increases the information content of the measurements and allows for a sufficiently accurate characterization of tropospheric aerosols. We conclude that a bistatic HSRL system would far exceed the capabilities of currently flown or planned orbital instruments in monitoring global aerosol effects on the environment and on the Earth's climate.

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A novel model for the variability in aerosol optical thickness (AOT) is presented. This model is based on the consideration of AOT fields as realizations of a stochastic process, that is the exponent of an underlying Gaussian process with a specific autocorrelation function. In this approach AOT fields have lognormal PDFs and structure functions having the correct asymptotic behavior at large scales.

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Remote sensing of aerosol optical properties is difficult, but multi-angle, multi-spectral, polarimetric instruments have the potential to retrieve sufficient information about aerosols that they can be used to improve global climate models. However, the complexity of these instruments means that it is difficult to intuitively understand the relationship between instrument design and retrieval success. We apply a Bayesian statistical technique that relates instrument characteristics to the information contained in an observation.

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Background: Recovery of post-stroke deficits can be achieved by modulating neuroplasticity with non-invasive brain stimulation. To evaluate potential effects of repetitive transorbital alternating current stimulation (rtACS) on stroke recovery we carried out a randomized, drug-controlled clinical trial.

Methods: Ninety-eight patients that had suffered ischemic stroke 21.

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Shadow-band radiometers in general, and especially the Multi-Filter Rotating Shadow-band Radiometer (MFRSR), are widely used for atmospheric optical depth measurements. The major programs running MFRSR networks in the United States include the Department of Energy Atmospheric Radiation Measurement (ARM) Program, U.S.

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