447 research outputs found
On Rigidity of 3d Asymptotic Symmetry Algebras
We study rigidity and stability of infinite dimensional algebras which are
not subject to the Hochschild-Serre factorization theorem. In particular, we
consider algebras appearing as asymptotic symmetries of three dimensional
spacetimes, the BMS3, u(1) Kac-Moody and Virasoro algebras. We construct and
classify the family of algebras which appear as deformations of BMS3, u(1)
Kac-Moody and their central extensions by direct computations and also by
cohomological analysis. The Virasoro algebra appears as a specific member in
this family of rigid algebras; for this case stabilization procedure is inverse
of the In\"on\"u-Wigner contraction relating Virasoro to BMS3 algebra. We
comment on the physical meaning of deformation and stabilization of these
algebras and relevance of the family of rigid algebras we obtainComment: 50 pages, one figure and two tables; v2: minor improvements,
references adde
Evaluating the effects of climate on weathering processes of rocks based on Peltier models in Kermanshah province
Weathering is a result of physical, chemical and biological factors, all of which affect the rocks but do not cause Material Handling. The existence of pores and crevices and cracks in the rocks expose the rocks to physical and chemical attack, gradual wracking and being weathered. This study has been based on Louis Peltier’s models in which two mean annual temperature and precipitation variables are used. Peltier identified seven models using these two variables which can describe different types of weathering phenomena. Among these models, two models related to weathering regimes and morphogenetic regimes were evaluated in case of Kermanshah province and the regimes related to each station were determined from the related diagrams. Climate data such as mean annual temperature and precipitation and eight synoptic stations which had appropriate data and statistical length were taken from meteorological organization and then were recorded in a database in GIS environment for studying and zoning of the weathering status and geomorphological regions in Kermanshah. Then, the regimes relating to each station were determined from Peltier models after evaluation of temperature and precipitation processes in the study area which were recorded in the database after giving weighted value to them and then the related maps were generated in ARC map environment. The obtained results showed that most parts of Kermanshah province are semi-arid regions. Chemical weathering along with glacial action to moderate chemical weathering take place in in Kermanshah province in terms of weathering status.Keywords: Weathering regimes, Peltier model, morphogenetic regions, Kermanshah
Species identification reveals mislabeling of important fish products in Iran by DNA barcoding
This study reports on the molecular identification of fish species from processed products which had a priori been classified as belonging to 5 important species in Iran for human consumption. DNA barcoding using direct sequencing of an approximately 650bp of mitochondrial Cytochrome oxidase subunit I (COI) gene revealed incorrect labeling of Narrow-barred Spanish mackerel samples. High occurrence of fraudulent fishery products, if left unchecked, can pose a negative impact on the economy. This investigation adds further concern on the trading of processed fish products in Iran from both health and conservation points of view
PP-173 Protein variations of Cryptosporidium spp. from different sources after proliferation in experimentally immunosuppressed mice
Pan-cancer classifications of tumor histological images using deep learning
Histopathological images are essential for the diagnosis of cancer type and selection of optimal treatment. However, the current clinical process of manual inspection of images is time consuming and prone to intra- and inter-observer variability. Here we show that key aspects of cancer image analysis can be performed by deep convolutional neural networks (CNNs) across a wide spectrum of cancer types. In particular, we implement CNN architectures based on Google Inception v3 transfer learning to analyze 27815 H&E slides from 23 cohorts in The Cancer Genome Atlas in studies of tumor/normal status, cancer subtype, and mutation status. For 19 solid cancer types we are able to classify tumor/normal status of whole slide images with extremely high AUCs (0.995±0.008). We are also able to classify cancer subtypes within 10 tissue types with AUC values well above random expectations (micro-average 0.87±0.1). We then perform a cross-classification analysis of tumor/normal status across tumor types. We find that classifiers trained on one type are often effective in distinguishing tumor from normal in other cancer types, with the relationships among classifiers matching known cancer tissue relationships. For the more challenging problem of mutational status, we are able to classify TP53 mutations in three cancer types with AUCs from 0.65-0.80 using a fully-trained CNN, and with similar cross-classification accuracy across tissues. These studies demonstrate the power of CNNs for not only classifying histopathological images in diverse cancer types, but also for revealing shared biology between tumors. We have made software available at: https://github.com/javadnoorb/HistCNNFirst author draf
Examination of value added of conservation and restoration of urban historic textures in district 12 of Tehran
The growth of urban populations in recent decades requires physical elements such as residential, commercial and cultural spaces and the development of infrastructure such as streets and highways, which will open a new horizon to the historic texture of cities and how to preserve and restore them. The development of new urban textures along with the lack of attention to the historic texture and the transformation of the form and structure of the old neighborhoods of the city, promotes the expansion of new physical elements and the oblivion of historic elements. In this research, first, various management dimensions and then issues related to the restoration and conservation of historic textures, problems with these types of textures, issues procedures and legal and historic measures are discussed, then by using the field survey in the direction of achieving quantitative and qualitative findings and in the format of statistical methods an using the questionnaire, the required data for the research are collected from managers and citizens and the results will be presented in the form of a chart. In this regard, four hypotheses are tested and are finally concluded and summed up. This research seeks to answer the question of whether restoring and conserving the historic texture of the District 12 of Tehran municipality could be achieved through the formulation of management strategies or not
Working memory and response inhibition in patients with bipolar I disorder during euthymic period
Background: Several cognitive domains, including attention, memory, and executive functions are impaired in bipolar disorder. Objectives: This study aimed to investigate two executive functions (working memory and response inhibition) in patients with bipolar I disorder during remission of the symptoms. Patients and Methods: In this case-control design, 30 bipolar I patients (18 to 45 years old) were matched with 30 ones in the control group in terms of age, gender, and education. The patients were selected from Roozbeh Psychiatric Hospital (a hospital affiliated to Tehran University of Medical Sciences) from May to October 2013. They were evaluated and contrasted using working memory (Spatial Span and Spatial Working Memory (SSP and SWM)) and response inhibition (Stop Signal Task (SST)) tests. Results: We used independent t-tests for comparing and contrasting 2 groups on total and sub-scales scores of these 3 tests. In terms of SWM test there was a significant difference in between-group error between the two groups (P = 0.05); there was also a meaningful difference between the strategies used by two groups (P = 0.05). In SSP test, a significant difference appeared between averages of span length of the two groups. In the first and last item delays, there was also a clear difference, but the total error index was not noticeably different. In SST test, the direction error indicator in start-stop trials indicated a major difference, while in successful stops ratio, the case group had a lower ratio. In addition, reaction time to stop signs in bipolar group was meaningfully lower than the control group. Conclusion: In conclusion, even during remission phase, executive dysfunction is detectable at least in some areas in patients with bipolar disorder. © 2015, Mazandaran University of Medical Sciences
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