110 research outputs found
Using information-communication technologies in educational process organization
© 2017. revistaESPACIOS.com. The article addresses the influence of informationcommunication technologies on the development and improvement of informational-educational environment of a modern university. It defines the tendencies of further development and methods of information and Internet technologies' application in informationaleducational environment of a university. The article presents and analyzes the results of a survey among students with the aim of revealing the level of activity in using informational-educational environment in the educational process. The following phenomena were defined as the tendencies of the development of informational-educational environment of a university: processes of converting universities' documents, document flows and communication channels to the electronic format; active introduction and use of electronic educational and educational-methodic documents; decrease of expenses related to the support of communication process, increase of its efficiency and accessibility of its results not only for university students and teachers but for the society in general by using the "free ware" type software. Control of students' knowledge is an important stage in the educational process. If the tests are designed correctly, students' knowledge, abilities and skills are reflected in the performance of the control tests' tasks. Knowledge control in the StartExam program is one the possible ways of increasing the efficiency of students' knowledge control and teacher's work capacity
Esophageal Lichen Planus as a Cause of Dysphagia: Literature Review and Clinical Observation
Aim: to analyze the literature data, and to raise awareness of doctors of various specialties about the methods of diagnosis and treatment of esophageal lichen planus (ELP).Key points. In a 67-year-old female patient with complaints of difficulty swallowing solid food and weight loss, esophagogastroduodenoscopy revealed subcompensated stenosis of the middle third of the esophagus and signs of fibrinous esophagitis. Based on the characteristics of the endoscopic picture and the detection of apoptotic Ciwatt bodies in esophageal biopsies, a diagnosis of ELP was established. Treatment with glucocorticosteroids led to relief of symptoms and positive endoscopic dynamics. ELP is rare and the least studied, data on this disease in the literature are presented mainly in the form of clinical observations and analysis of series of cases. Typical clinical manifestations include dysphagia and odynophagia. Despite the low prevalence, ELP can be associated with serious complications: stenosis and esophageal squamous cell carcinoma. Endoscopic examination reveals characteristic signs in the esophagus: swelling, thickening and increased vulnerability of the mucosa, often with fibrin, formation of membranes and strictures. The histological picture is represented by epithelial dyskeratosis with exfoliation, lichenoid lymphocytic infiltration. The most specific histological sign is the presence of apoptotic Civatte bodies. Recommendations for the treatment of ELP are limited to the results of a series of clinical observations and include the prescription of systemic corticosteroids. The issue of supportive therapy is the least studied.Conclusion. Analysis of the literature data and the clinical case demonstrate that lichen planus of the esophagus is one of the rare causes of dysphagia. Characteristic endoscopic and histological signs are key for the diagnosis. The management of patients with esophageal lichen planus is insufficiently defined and today includes taking of glucocorticosteroids, endoscopic dilation of stricture and dynamic endoscopic observation, given the high risk of squamous cell carcinoma in this category of patients
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The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP) contribution to CMIP6: investigation of sea-level and ocean climate change in response to CO₂ forcing
The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP) aims to investigate the spread in simulations of sea-level and ocean climate change in response to CO2 forcing by atmosphere–ocean general circulation models (AOGCMs). It is particularly motivated by the uncertainties in projections of ocean heat uptake, global-mean sea-level rise due to thermal expansion and the geographical patterns of sea-level change due to ocean density and circulation change. FAFMIP has three tier-1 experiments, in which prescribed surface flux perturbations of momentum, heat and freshwater respectively are applied to the ocean in separate AOGCM simulations. All other conditions are as in the pre-industrial control. The prescribed fields are typical of pattern and magnitude of changes in these fluxes projected by AOGCMs for doubled CO2 concentration. Five groups have tested the experimental design with existing AOGCMs. Their results show diversity in the pattern and magnitude of changes, with some common qualitative features. Heat and water flux perturbation cause the dipole in sea-level change in the North Atlantic, while momentum and heat flux perturbation cause the gradient across the Antarctic Circumpolar Current. The Atlantic meridional overturning circulation (AMOC) declines in response to the heat flux perturbation, and there is a strong positive feedback on this effect due to the consequent cooling of sea-surface temperature in the North Atlantic, which enhances the local heat input to the ocean. The momentum and water flux perturbations do not substantially affect the AMOC. Heat is taken up largely as a passive tracer in the Southern Ocean, which is the region of greatest heat input, while the weakening of the AMOC causes redistribution of heat towards lower latitudes. Future analysis of these and other phenomena with the wider range of CMIP6 FAFMIP AOGCMs will benefit from new diagnostics of temperature and salinity tendencies, which will enable investigation of the model spread in behaviour in terms of physical processes as formulated in the models
The Art of Detection
The objective of this work is to recognize object categories in paintings, such as cars, cows and cathedrals. We achieve this by training classifiers from natural images of the objects. We make the following contributions: (i) we measure the extent of the domain shift problem for image-level classifiers trained on natural images vs paintings, for a variety of CNN architectures; (ii) we demonstrate that classificationby-detection (i.e. learning classifiers for regions rather than the entire image) recognizes (and locates) a wide range of small objects in paintings that are not picked up by image-level classifiers, and combining these two methods improves performance; and (iii) we develop a system that learns a region-level classifier on-the-fly for an object category of a user’s choosing, which is then applied to over 60 million object regions across 210,000 paintings to retrieve localised instances of that category
Delayed baroclinic response of the Antarctic circumpolar current to surface wind stress
Author Posting. © Science in China Press, 2008. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Science in China Series D: Earth Sciences 51 (2008): 1036-1043, doi:10.1007/s11430-008-0074-8.Antarctic Circumpolar Current (ACC) responds to the surface windstress via two processes, i.e., instant barotropic process and delayed baroclinic process. This study focuses on the baroclinic instability mechanism in ACC. That is, the strengthening of surface zonal windstress causes the enhanced tilting of the isopycnal surface, which leads to the intense baroclinic instability. Simultaneously, the mesoscale eddies resulting from the baroclinic instability facilitate the transformation of mean potential energy to eddy energy, which causes the remarkable decrease of the ACC volume transport with the 2-year lag time. This delayed negative correlation between the ACC transport and the zonal windstress may account for the steadiness of the ACC transport in these two decades.Supported by NSCF Outstanding Young Scientist Award (Grant No. 40625017) and the National Basic Research Program of China (Grant No. 2006CB403604). The research was also supported by W. Alan Clark Chair from Woods Hole Oceanographic Institution for RXH and NOAA GLERL contribution No. 1462 for J
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Freshwater transport in the coupled ocean-atmosphere system: a passive ocean
Conservation of water demands that meridional ocean and atmosphere freshwater transports (FWT) are of equal magnitude but opposite in direction. This suggests that the atmospheric FWT and its associated latent heat (LH) transport could be thought of as a \textquotedblleft coupled ocean/atmosphere mode\textquotedblright. But what is the true nature of this coupling? Is the ocean passive or active?
Here we analyze a series of simulations with a coupled ocean-atmosphere-sea ice model employing highly idealized geometries but with markedly different coupled climates and patterns of ocean circulation. Exploiting streamfunctions in specific humidity coordinates for the atmosphere and salt coordinates for the ocean to represent FWT in their respective medium, we find that atmospheric FWT/LH transport is essentially independent of the ocean state. Ocean circulation and salinity distribution adjust to achieve a return freshwater pathway demanded of them by the atmosphere. So, although ocean and atmosphere FWTs are indeed coupled by mass conservation, the ocean is a passive component acting as a reservoir of freshwater
Enhanced warming over the global subtropical western boundary currents
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Climate Change 2 (2012): 161-166, doi:10.1038/nclimate1353.Subtropical western boundary currents are warm, fast flowing currents that
form on the western side of ocean basins. They carry warm tropical water to the
mid-latitudes and vent large amounts of heat and moisture to the atmosphere
along their paths, affecting atmospheric jet streams and mid-latitude storms, as
well as ocean carbon uptake. The possibility that these highly energetic and
nonlinear currents might change under greenhouse gas forcing has raised
significant concerns, but detecting such changes is challenging owing to limited
observations. Here, using reconstructed sea surface temperature datasets and
newly developed century-long ocean and atmosphere reanalysis products, we
find that the post-1900 surface ocean warming rate over the path of these
currents is two to three times faster than the global mean surface ocean warming
rate. The accelerated warming is associated with a synchronous poleward shift
and/or intensification of global subtropical western boundary currents in
conjunction with a systematic change in winds over both hemispheres. This enhanced warming may reduce ocean's ability to absorb anthropogenic carbon
dioxide over these regions. However, uncertainties in detection and attribution of
these warming trends remain, pointing to a need for a long-term monitoring
network of the global western boundary currents and their extensions.This work is supported by China National Key Basic Research Project
(2007CB411800) and National Natural Science Foundation Projects (40788002,
40921004). WC is supported by the Australian Climate Change Science program and
the Southeast Australia Climate Initiative. HN is supported in part by the Japanese
Ministry of Education, Culture, Sports, Science and Technology through Grant-in-Aid
for Scientific Research on Innovative Areas #2205 and by the Japanese Ministry of
Environment through Global Environment Research Fund (S-5). MJM is supported by
NOAA’s Climate Program Office.2012-07-2
Rewriting a Deep Generative Model
A deep generative model such as a GAN learns to model a rich set of semantic
and physical rules about the target distribution, but up to now, it has been
obscure how such rules are encoded in the network, or how a rule could be
changed. In this paper, we introduce a new problem setting: manipulation of
specific rules encoded by a deep generative model. To address the problem, we
propose a formulation in which the desired rule is changed by manipulating a
layer of a deep network as a linear associative memory. We derive an algorithm
for modifying one entry of the associative memory, and we demonstrate that
several interesting structural rules can be located and modified within the
layers of state-of-the-art generative models. We present a user interface to
enable users to interactively change the rules of a generative model to achieve
desired effects, and we show several proof-of-concept applications. Finally,
results on multiple datasets demonstrate the advantage of our method against
standard fine-tuning methods and edit transfer algorithms.Comment: ECCV 2020 (oral). Code at https://github.com/davidbau/rewriting. For
videos and demos see https://rewriting.csail.mit.edu
A comparison of the radiosensitisation ability of 22 different element metal oxide nanoparticles using clinical megavoltage X-rays
Background: A wide range of nanoparticles (NPs), composed of different elements and their compounds, are being developed by several groups as possible radiosensitisers, with some already in clinical trials. However, no systematic experimental survey of the clinical X-ray radiosensitising potential of different element nanoparticles has been made. Here, we directly compare the irradiation-induced (10 Gy of 6-MV X-ray photon) production of hydroxyl radicals, superoxide anion radicals and singlet oxygen in aqueous solutions of the following metal oxide nanoparticles: Al2O3, SiO2, Sc2O3, TiO2, V2O5, Cr2O3, MnO2, Fe3O4, CoO, NiO, CuO, ZnO, ZrO2, MoO3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb4O7, Dy2O3, Er2O3 and HfO2. We also examine DNA damage due to these NPs in unirradiated and irradiated conditions.
Results: Without any X-rays, several NPs produced more radicals than water alone. Thus, V2O5 NPs produced around 5-times more hydroxyl radicals and superoxide radicals. MnO2 NPs produced around 10-times more superoxide anions and Tb4O7 produced around 3-times more singlet oxygen. Lanthanides produce fewer hydroxyl radicals than water. Following irradiation, V2O5 NPs produced nearly 10-times more hydroxyl radicals than water. Changes in radical concentrations were determined by subtracting unirradiated values from irradiated values. These were then compared with irradiation-induced changes in water only. Irradiation-specific increases in hydroxyl radical were seen with most NPs, but these were only significantly above the values of water for V2O5, while the Lanthanides showed irradiation-specific decreases in hydroxyl radical, compared to water. Only TiO2 showed a trend of irradiation-specific increase in superoxides, while V2O5, MnO2, CoO, CuO, MoO3 and Tb4O7 all demonstrated significant irradiation-specific decreases in superoxide, compared to water. No irradiation-specific increases in singlet oxygen were seen, but V2O5, NiO, CuO, MoO3 and the lanthanides demonstrated irradiation-specific decreases in singlet oxygen, compared to water. MoO3 and CuO produced DNA damage in the absence of radiation, while the highest irradiation-specific DNA damage was observed with CuO. In contrast, MnO2, Fe3O4 and CoO were slightly protective against irradiation-induced DNA damage.
Conclusions: Beyond identifying promising metal oxide NP radiosensitisers and radioprotectors, our broad comparisons reveal unexpected differences that suggest the surface chemistry of NP radiosensitisers is an important criterion for their success
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