Variceal Hemorrhage: Decompression, Obliteration, or Both?

Variceal hemorrhage is a morbid condition that frequently mandates the involvement of interventional radiology to achieve successful and sustained hemostasis. Primary image-guided therapies for variceal hemorrhage include a transjugular intrahepatic portosystemic shunt and transvenous obliteration. Knowledge of variceal pathophysiology and anatomy, current techniques, and the evidence supporting therapeutic selection is paramount to successful patient outcomes. The purpose of this review is to provide the reader a framework of the available literature on image-guided management of bleeding varices to assist in clinical management.

TXM-Sandbox: an open-source software for transmission X-ray microscopy data analysis

A transmission X-ray microscope (TXM) can investigate morphological and chemical information of a tens to hundred micrometre-thick specimen on a length scale of tens to hundreds of nanometres. It has broad applications in material sciences and battery research. TXM data processing is composed of multiple steps. A workflow software has been developed that integrates all the tools required for general TXM data processing and visualization. The software is written in Python and has a graphic user interface in Jupyter Notebook. Users have access to the intermediate analysis results within Jupyter Notebook and have options to insert extra data processing steps in addition to those that are integrated in the software. The software seamlessly integrates ImageJ as its primary image viewer, providing rich image visualization and processing routines. As a guide for users, several TXM specific data analysis issues and examples are also presented.

Identification of disjunctive dislocations as one of the parameters for estimating a territory seismicity of North Sakhalin

The north of Sakhalin Island is characterized by frequent earthquakes and many disjunctive dislocations. One of the catastrophic earthquakes occurred in the settlement of Neftegorsk. The level of modern technologies makes it possible to track the change in environmental parameters accompanying dangerous natural processes with a high degree of certainty. The article proposes an interpretating technology for disjunctive dislocations detecting, which differs from the existing ones with the complex use and summation of satellite image data using image processing methods widely applied in “computer vision”. The study aims to compile and describe a map of discontinuous faults of the village of Neftegorsk, located in the northern part of Sakhalin Island, using the developed decoding technology and geophysical data. Methods: Identification methods used in the work: 1) methods of primary image processing (correction, transformation, resolution change, cropping, visualization); 2) a set of “contextual” and “autonomous” methods of lineament analysis, with the help of which a series of images is processed (canny, erosion, Hough’s algorithm); 3) methods for constructing maps of discontinuous faults (summation, sequential linking). Results. Using the developed technology, a map of discontinuous faults in the area of the Neftegorsk earthquake was constructed. The implementation of the technology makes it possible to provide the monitoring data on discontinuous faults to organizations that are engaged in seismic zoning, construction and operation of objects for various purposes, including mineral deposits.

Leveraging autoencoders in change vector analysis of optical satellite images

Various applications in remote sensing demand automatic detection of changes in optical satellite images of the same scene acquired over time. This paper investigates how to leverage autoencoders in change vector analysis, in order to better delineate possible changes in a couple of co-registered, optical satellite images. Let us consider both a primary image and a secondary image acquired over time in the same scene. First an autoencoder artificial neural network is trained on the primary image. Then the reconstruction of both images is restored via the trained autoencoder so that the spectral angle distance can be computed pixelwise on the reconstructed data vectors. Finally, a threshold algorithm is used to automatically separate the foreground changed pixels from the unchanged background. The assessment of the proposed method is performed in three couples of benchmark hyperspectral images using different criteria, such as overall accuracy, missed alarms and false alarms. In addition, the method supplies promising results in the analysis of a couple of multispectral images of the burned area in the Majella National Park (Italy).

Influence of Using a Contrast-Enhanced CT Image as the Primary Image on CyberKnife Brain Radiosurgery Treatment Plans

Background and PurposeThis study aimed to quantify the differences between pre- and post-contrast agent (CA) CT for CyberKnife brain SRS plans.Materials and MethodsTwenty-five patients were retrospectively analyzed. They were divided into two categories, inhomogeneous cases (13 patients) and homogeneous cases (12 patients), according to whether the tumor was close to the cavity and inhomogeneous tissues or not. The pre-CA and post-CA plans were designed and calculated using the same monitor unit and paths as those in the ray-tracing algorithm, respectively.ResultsThe CT number difference of tumor between pre- and post-CA was significant (on average, 24.78 ± 18.56 HU, P-value < 0.01). The deviation value of the target was the largest at approximately 37 HU (inhomo-) and 13 HU (homo-) (P < 0.01), and the values of the organs at risk (OARs) were not statistically significant (P-value > 0.05). However, it was not statistically significant for the dose difference between the two groups with the injection of CA (P-value > 0.05). The absolute effective depth difference generally remained at a level of 1 mm, but the dose difference was quitely fluctuated sometimes more than 20%. The absolute effective depth difference of the inhomo-case (0.62 mm) was larger than that of the homo-case (0.37 mm) on median, as well as the variation amplitude (P-value < 0.05). Moreover, the relative dose differences between the two cases were 0.38% (inhomo-) and 0.2% (homo-), respectively (P-value < 0.05). At the criterion of 1 mm/1%, the gamma pass rate of the homo-case (95.89%) was larger than that of the inhomo-case (93.79%). For the OARs, except for the cochlea, the two cases were almost the same (>98.85%). The tumor control probability of the target was over 99.99% before and after injection of a CA, as well as the results for the homo-case and inhomo-case.ConclusionsConsidering the difference of evaluation indexes between pre- and post-CA images, we recommended plain CT to be employed as the primary image for improving the CK treatment accuracy of brain SRS, especially when the target was close to CA-sensitive OARs and cavity.

The Importance of Socio-Economic Primary and Secondary Images for Thailand’s Tourism: A Case Study of Swedish Tourists

Swedish tourists constitute one of the most important markets for Thailand’s tourism industry. On average, Swedish tourists stay in Thailand 9 days and spend 101 euros per day. Their image of Thailand plays a significant role in deciding to visit or revisit Thailand. The socio-economic primary image consists of five factors: safety and security, feeling at home during their visit to Thailand, money value, the trip exceeding their expectation, and the ease of making trip arrangements. These are crucial factors that determine the level of satisfaction tourists experience during their trip. These factors also help determine whether the tourists visit Thailand again in the future.

Predictors of correct interpretation of English and Bulgarian idioms by Russian speakers

During intercultural communication, it is crucial to interpret correctly and to use appropriately foreign idioms which are culturally marked and reflect linguistic and cultural identity of a speech community. Interlocutors should be aware of the cultural and historical precedents that gave rise to the primary image underlying idiomatic expressions and thus created their unique phraseological worldview. The aim of the research is to find out what is a better predictor of correct idiom interpretation - degree of proficiency in a foreign language or degree of genealogical kinship between the native and foreign languages. The topicality of the research is justified by the need for a deeper understanding of linguistic and cultural identity of native and foreign-language speakers, with a view to facilitate and enhance cross-cultural communication. The working hypothesis is that due to the close genealogical kinship between Russian and Bulgarian and the users advanced level of English, the number of correctly interpreted idioms may vary within a statistically significant medium range. The total sample comprises 5000 idioms (2500 English and 2500 Bulgarian ones). The subsample used in the experiment comprises 60 idioms (30 English and 30 Bulgarian ones) selected from The Oxford Dictionary of Idioms and Nov fraseologichen rechnik na bylgarskiya jezik (Нов фразеологичен речник на българския език) by means of stratified systematic sampling. The main methods used in the research include (1) comparative linguistic and cultural analyses, (2) scientific experimentation, (3) systematic and stratified sampling, and (4) a paired t-test. The experimental research and the paired t-test have proved our hypothesis and demonstrated that Russian participants correctly decode more Bulgarian than English idioms, with intergroup variation being statistically significant. Research findings have implications for cultural linguistics. Since translation loans (calques), isomorphic idioms, and idioms dating back to a common source are interpreted more quickly and more accurately than idioms which contain unique or culturally-loaded elements, such as old-fashioned words or proper names, access to cultural precedents that served as prototypes of set expressions contributes to a more seamless code-switching and enables communicants to penetrate deeper the mentality of a specific linguacultural community and thus become aware of the variability of cultural cognition and conceptualisation.

Hybrid Compact Polarimetric SAR for Environmental Monitoring with the RADARSAT Constellation Mission

Canada’s successful space-based earth-observation (EO) radar program has earned widespread and expanding user acceptance following the launch of RADARSAT-1 in 1995. RADARSAT-2, launched in 2007, while providing data continuity for its predecessor’s imaging capabilities, added new polarimetric modes. Canada’s follow-up program, the RADARSAT Constellation Mission (RCM), launched in 2019, while providing continuity for its two predecessors, includes an innovative suite of polarimetric modes. In an effort to make polarimetry accessible to a wide range of operational users, RCM uses a new method called hybrid compact polarization (HCP). There are two essential elements to this approach: (1) transmit only one polarization, circular; and (2) receive two orthogonal polarizations, for which RCM uses H and V. This configuration overcomes the conventional dual and full polarimetric system limitations, which are lacking enough polarimetric information and having a small swath width, respectively. Thus, HCP data can be considered as dual-pol data, while the resulting polarimetric classifications of features in an observed scene are of comparable accuracy as those derived from the traditional fully polarimetric (FP) approach. At the same time, RCM’s HCP methodology is applicable to all imaging modes, including wide swath and ScanSAR, thus overcoming critical limitations of traditional imaging radar polarimetry for operational use. The primary image data products from an HCP radar are different from those of a traditional polarimetric radar. Because the HCP modes transmit circularly polarized signals, the data processing to extract polarimetric information requires different approaches than those used for conventional linearly polarized polarimetric data. Operational users, as well as researchers and students, are most likely to achieve disappointing results if they work with traditional polarimetric processing tools. New tools are required. Existing tutorials, older seminar notes, and reference papers are not sufficient, and if left unrevised, could succeed in discouraging further use of RCM polarimetric data. This paper is designed to provide an initial response to that need. A systematic review of studies that used HCP SAR data for environmental monitoring is also provided. Based on this review, HCP SAR data have been employed in oil spill monitoring, target detection, sea ice monitoring, agriculture, wetland classification, and other land cover applications.

Отражение стереотипных представлений о русских людях в практике преподавания русского языка как иностранного (на примере китайских учебников)

В статье анализируются китайские учебники русского языка с точки зрения отражения в них стереотипных представлений о поведении русского человека в различных бытовых ситуациях. Материал ограничен темами первого года обучения, в течение которого у китайских студентов языковых факультетов закладываются основы знаний о русской культуре, это темы «Семья», «О себе», «Учёба», «Рабочий день», «В гостях», «Отдых», «У врача», «В кафе», «Магазины, покупки». Авторы привлекают внимание к спорным моментам в учебном материале, требующем специального комментария преподавателя русского языка. В статье анализируются как положительные, так и отрицательные стереотипы, которые служат основой для создания первичного образа представителя русской культуры. При анализе материала был использован сопоставительный метод. русский язык как иностранный, русский язык в Китае, стереотипные представления, китайские учебники русского языка, «Русский язык в университетах (Восток)», стереотипы о русских именах, внешность русских, поведение и привычки русских людей, устаревшая информация The article analyzes Chinese textbooks of the Russian language from the point of view of their reflection of stereotypical ideas about the behavior of a Russian person in various everyday situations. The material is limited to the topics of the first year of study, during which Chinese students of language faculties learn the basics of knowledge about Russian culture. The list of topics includes: “Family”, “About Me”, “Study”, “Workday”, “Away”, “Rest”, “At the doctor”, “In a cafe”, and “Supermarkets, purchases”. The authors draw attention to controversial points in the educational material, requiring special commentary from the Russian language teacher. The article analyzes both positive and negative stereotypes, which are the basis for creating the primary image of a representative of Russian culture. The image of a Russian person represented in first-year textbooks is not ideal, both advantages and vices are noted. The authors also point out that some of the material in the Chinese textbooks no longer corresponds to today’s Russian reality and needs to be corrected. A comparative method is used in the analysis of the material. Russian as a foreign language, Russian language in China, stereotypes, Chinese textbooks of the Russian language, “Russian language at universities (East)”, stereotypes about Russian names, Russian appearance, behavior and habits of Russian people, outdated information

A Long Timescale Stimulus History Effect in the Primary Visual Cortex

Responses of neurons in the primary visual cortex (V1) are often understood as encoding the current visual stimulus. Yet, some studies indicate that temporal contingency effects exist in the responses of neurons in early sensory areas. We explored if the recent stimulus history would alter the response of V1 layer 2/3 pyramidal cells in head-fixed awake mice during presentation of sequences of complex images. The activity of individual neurons was sparse, such that either one or none of the images in the sequence typically yielded a strong response. We then substituted an image preceding this primary image in order to determine if responses to the primary image were affected. We found that the amplitude of the neuron’s response could be significantly altered by substitutions up to five images back from the primary image, even when the substituted image elicited virtually no response by itself. This stimulus history effect was heterogeneous across the population, with some cells showing facilitation and others suppression. For individual cells, the history effect was robust and reproducible across days. Our data show that responses of V1 neurons not only reflect the current stimulus but also encode, through their response amplitude, information about multiple images previously presented as far as 1000 msec in the past. This might enable V1 to retain information about the extended trajectory of past stimuli and perform complex temporal computations that are as of yet not appreciated.