185 research outputs found

    Reservoir computing for macroeconomic forecasting with mixed-frequency data

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    Macroeconomic forecasting has recently started embracing techniques that can deal with large-scale datasets and series with unequal release periods. Mixed-data sampling (MIDAS) and dynamic factor models (DFMs) are the two main state-of-the-art approaches to modeling series with non-homogeneous frequencies. We introduce a new framework, called the multi-frequency echo state network (MFESN), based on a relatively novel machine learning paradigm called reservoir computing. Echo state networks (ESNs) are recurrent neural networks formulated as nonlinear state-space systems with random state coefficients where only the observation map is subject to estimation. MFESNs are considerably more efficient than DFMs and can incorporate many series, as opposed to MIDAS models, which are prone to the curse of dimensionality. All methods are compared in extensive multistep forecasting exercises targeting U.S. GDP growth. We find that our MFESN models achieve superior or comparable performance over MIDAS and DFMs at a much lower computational cost

    Search for potential gastric cancer markers using miRNA databases and gene expression analysis

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    Aim: The aim of this study was to identify genes that are differentially expressed in gastric tumors and to analyze the association of their expression level with tumor clinicopathologic features. Methods: In the present research, we used bioinformatic-driven search to identify miRNA that are down-regulated in gastric tumors and to find their potential targets. Then, the expression levels of some of the target mRNAs were investigated using reverse transcription polymerase chain reaction (RT-PCR) analysis. Results: As a result of the bioinformatics analysis, fifteen genes were found to be potentially differentially expressed between the tumors and normal gastric tissue. Five of them were chosen for the further analysis (WNT4, FGF12, EFEMP1, CTGF, and HSPG2) due to their important role in cell proliferation and differentiation. Expression levels of these genes were evaluated in our collection of frozen tissue samples of gastric tumor and paired normal stomach epithelia. Increased FGF12 expression was observed in diffuse type of gastric cancer while WNT4 mRNA was found to be down-regulated in intestinal type of gastric cancer. Besides, CTGF gene overexpression was revealed in diffuse type of stomach cancer in comparison with that in intestinal type. Up-regulation of CTGF was also associated with lymph node metastasis. Conclusions: The findings show its expedient to perform further investigations in order to clarify diagnostic and prognostic value of CTGF, FGF12, and WNT4’s in stomach cancer as well as the role of these genes in carcinogenesis

    WOUND HEALING EFFECT OF POLYHEXAMETHYLENE GUANIDINE HYDROCHLORIDE HYDROGELAT BURNS

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    This article considers the wound-healing effect of a hydrogel based on polyhexamethyleneguanidine hydrochloride under conditions of thermal shock modeling. The presence of gelling properties in combination with the high biocidal activity of polyguanidins opens the prospect of obtaining an effective single-component external agent, which is very important for antimicrobial chemotherapy of wounds and burns, as in their treatment there is a high probability of infecting the wound with microorganisms causing various infectious diseases. Previously, we developed a method for the preparation of a hydrogel based on polyhexamethyleneguanidine hydrochloride, which involves the cross-linking of the amino-end groups of the branched polymer with formaldehyde, resulting in a cross-linked polymer, which is a lump-like mass. The mechanical treatment of the hydrogel makes it possible to give the material an ointment form that is convenient for application to the skin. An experiment on the evaluation of the wound healing action of hydrogel was carried out under the conditions of modeling a thermal burn. The comparative preparation was multicomponent gel "Levomekol", in which polyethylene oxide was used as the basis. It was established that the hydrogel activates the growth of antioxidants and leukocytes in the blood of animals in dynamics on the 10th, 17th and 24th day of the experiment, amounting to 56.4 %, 33.8 % and 20.9 %, and of leukocytes - 27.7 %, 19.6 %; 6,2 % in relation to the norm. The method of contrast radiography of penetrating wounds showed that the daily reduction in the wound area is most pronounced in the hydrogel group, which indicates a pronounced reparative effect

    Acute Toxicity of Hydrogel Polyhexamethylene Guanidine Hydrochloride

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    Background. Previously, we have shown that the polyhexamethylene guanidine hydrochloride hydrogel exhibits a pronounced wound healing. At the same time, no studies of the toxic effect of the hydrogel on animals have been conducted. Aim of the research. In the framework of this work, the acute toxicity of the hydrogel polyhexamethylene guanidine hydrochloride was studied in laboratory animals with intragastric administration. Materials and methods. The polyhexamethylene guanidine hydrochloride hydrogel was obtained by crosslinking the amino end groups with formaldehyde. An acute toxicity study was carried out (P 1.2.3156-13, GOST 32644-2014 and the Guidelines for conducting preclinical studies of drugs) in an experiment on outbred mice with a single addition of the test substance in different doses (1000, 3000, 5000, 8000 mg/kg) with fixing indicators (appearance, behavior, condition of the body hair coat, water and food consumption, excretion, body weight and its growth) during 14 days. After the animals were withdrawn from the experiment, autopsy, macroscopic evaluation and weighing of the internal organs were performed. The results showed that with the introduction of the test substance into the animal organism, death during the observation period (14 days) did not occur. It was not possible to determine the semi-lethal dose for the test compound. Conclusion. The conducted studies allow us to conclude that this substance is practically non-toxic and can be classified as hazard class V. Further research will be directed to the formation of hydrogel compositions with medicinal substances

    Shotgun metagenomic data on the human stool samples to characterize shifts of the gut microbial profile after the Helicobacter pylori eradication therapy

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    © 2017 The Authors The shotgun sequencing data presented in this report are related to the research article named “Gut microbiome shotgun sequencing in assessment of microbial community changes associated with H. pylori eradication therapy” (Khusnutdinova et al., 2016) [1]. Typically, the H. pylori eradication protocol includes a prolonged two-week use of the broad-spectrum antibiotics. The presented data on the whole-genome sequencing of the total DNA from stool samples of patients before the start of the eradication, immediately after eradication and several weeks after the end of treatment could help to profile the gut microbiota both taxonomically and functionally. The presented data together with those described in Glushchenko et al. (2017) [2] allow researchers to characterize the metagenomic profiles in which the use of antibiotics could result in dramatic changes in the intestinal microbiota composition. We perform 15 gut metagenomes from 5 patients with H. pylori infection, obtained through the shotgun sequencing on the SOLiD 5500 W platform. Raw reads are deposited in the ENA under project ID PRJEB21338

    The influence of biological products and growth regulators on the yield and quality indicators of pea seeds of various varieties

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    Abstract Peas are an important agricultural crop of great importance in human and animal nutrition. Peas, being a legume crop, help replenish nitrogen reserves in the soil. In field studies of the Federal State Budgetary Scientific Institution of the Federal Scientific Center of Legumes and Goat Crops (Oryol region), the influence of various growth regulators and biological products on the yield and quality indicators of pea seeds of the Nord and Multik varieties was studied. Pea plants are grown on dark gray forest, medium loamy soil of average cultivation. Before sowing, pea seeds were treated with solutions of Kornevin, Albit and Epin-extra by soaking for 5 hours. Solutions of the drugs were used at a concentration of 10-6 M, then dried and treated with Rizotorfin before sowing. Growth rates during the growing season and the yield of pea plants were determined. The content of protein, starch and amylose in starch was determined in the seeds. Research results have shown that the yield of pea plants depends on weather conditions. Under favorable weather conditions, the highest yield was obtained from the pea variety Nord (42.2 c/ha) in the variant with seed treatment with Kornevin, and in the Multik variety (43.0 c/ha) when treated with Rizotorfin. In arid conditions, the highest yield of peas of the Nord variety was obtained using the preparations Epin-extra and Kornevin. The highest yield of peas of the Multik variety was obtained using the preparations Rizotorfin, Kornevin and Epin-Extra. The research results, confirmed by statistical evaluation, showed that bioregulators and growth regulators help stimulate the amount of nitrogen supplied to plants, as well as the synthetic processes of protein synthesis. This contributed to improving the quality of seeds and green mass

    The influence of agrotechnologies of organic farming on the content of humus, phosphorus and potassium in the soil

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    Abstract Organic agriculture is becoming an increasingly popular direction in modern agriculture. At the same time, some researchers and practitioners still have doubts about the ability of this technology to maintain the balance of nutrients in the soil. The article is a contribution to the study of the influence of long-term organic farming on agrochemical soil parameters. The aim of the study was to study the influence of organic farming technology on the content of humus, mobile forms of potassium and mobile forms of phosphorus in the soil of the most important components for fertility – humus, mobile forms of potassium and mobile forms of phosphorus in the non-carbonate chernozems of Western Siberia. The chernozems of Western Siberia are characterized by a high content of humus and nutrients, have optimal properties for agricultural crops. A statistically processed comparison of the quantitative content of humus, mobile forms of potassium and mobile forms of phosphorus in fields with long-term use of organic farming technology, and in similar fields where this technology was not used, was carried out. The article includes a brief geographical, geological, climatic characteristics of the place of the experiment, a description of the applied agricultural technologies and fertilizers. As a result, it was found that the use of organic farming technology has a positive effect on the state of soils, which is confirmed by an increase in the content of humus, mobile forms of potassium and mobile forms of phosphorus

    Radiative emission of solar features in the Ca II K line: comparison of measurements and models

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    We study the radiative emission of various types of solar features, such as quiet Sun, enhanced network, plage, and bright plage regions, identified on filtergrams taken in the Ca II K line. We analysed fulldisk images obtained with the PSPT, by using three interference filters that sample the Ca II K line with different bandpasses. We studied the dependence of the radiative emission of disk features on the filter bandpass. We also performed a NLTE spectral synthesis of the Ca II K line integrated over the bandpass of PSPT filters. The synthesis was carried out by utilizing both the PRD and CRD with the most recent set of semi empirical atmosphere models in the literature and some earlier atmosphere models. We measured the CLV of intensity values for various solar features identified on PSPT images and compared the results obtained with those derived from the synthesis. We find that CRD calculations derived using the most recent quiet Sun model, on average, reproduce the measured values of the quiet Sun regions slightly more accurately than PRD computations with the same model. This may reflect that the utilized atmospheric model was computed assuming CRD. Calculations with PRD on earlier quiet Sun model atmospheres reproduce measured quantities with a similar accuracy as to that achieved here by applying CRD to the recent model. We also find that the median contrast values measured for most of the identified bright features, disk positions, and filter widths are, on average, a factor 1.9 lower than those derived from PRD simulations performed using the recent bright feature models. The discrepancy between measured and modeled values decreases by 12% after taking into account straylight effects on PSPT images. PRD computations on either the most recent or the earlier atmosphere models of bright features reproduce measurements from plage and bright plage regions with a similar accuracy.Comment: 14 pages, 18 figures, accepted by A&
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