444 research outputs found

    About some economic applications of cohort analysis

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    Nowadays, there is the problem of evaluating the return on advertising costs for industries with a delayed conversion. Cohort analysis is a series of studies which are conducted at certain time intervals. Using cohort analysis we can better assess the effectiveness of advertising channels for industries with a delayed conversion. Cohort analysis can be used to analyze following items: efficiency in the context of "traffic sources", usefulness of changes on the web site; assessment of effectiveness of marketing campaigns; assessment of impact of seasonality on the behavior of the user; the decision-making period. The article presents an overview of tools we can use to collect data for analysis. The article also describes the method of selection and the variants of the cohorts to construct the analysis. For demonstration of the proposed method and calculation variant, there is considered the practical example of building a cohort analysis. Using these method and the example of calculating, the companies with delayed conversion can analyze the effectiveness of Internet advertising for different advertising channels. © 2018 Author(s)

    Activity of lectins of winter wheat seedlings infected with mycoplasma and treated with salicylic acid

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    Changes in activity of soluble and cell wall lectins have been revealed in seedlings of winter wheat Triticum aestivum L. cultivar Mironovskaya 808 after infection with mycoplasma Acholeplasma laidlawii 118. The protective effect of salicylic acid was manifested as negating the bursts of lectin activity induced by mycoplasma infection. © 2005 Pleiades Publishing, Inc

    Change in lectin specificity of winter wheat seedlings in the course of infection with mycoplasms

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    The activity of soluble lectins in leaves and roots of seedlings of winter wheat (Triticum aestivum L.) cultivar Mironovskaya 808 increased 1 day and 2 days, respectively, after infection with the mycoplasma Acholeplasma laidlawii 118. Analysis of acid-soluble proteins of wheat leaves by PAGE revealed the appearance of 22- and 20-kDa polypeptides, the disappearance of a 14-kDa polypeptide, and an increase in the content of polypeptides with molecular weights of 76, 48, 25, and 18 kDa. The 18-kDa polypeptide is a subunit of wheat germ agglutinin. A change in the activity of lectins may be a nonspecific response of plants to infection with the pathogen

    Methods of probe microscopy in the study of topography and elastic properties of cold-resistant elastomers

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    The work was carried out under the financial support of the Russian Science Fund, grant 14-29-00198-П(sample preparation and scanning electron microscopy) and the Federal Agency of Scientific Organizations - Agreement No 007-ГЗ/Ч3363/26 (scanning probe microscopy)

    SYNTHESIS OF 2,6-DIAMINOPYRIDINE-4-NITROPHENOL (2,6DAP4N) COCRYSTAL NANOPARTICLES BY LASER ABLATION METHOD

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    We propose findings for laser ablation of organic materials in liquids as one of the perspective methods of nanoparticles synthesis on their basis. We describe nanoparticles synthesis for 2,6-diaminopyridine-4-nitrophenol (2,6DAP4N) cocrystal by the method of material laser ablation at nanoparticles condensation in liquid (dodecane and polyphenyleneoxide). Laser radiation with wavelength equal to 355 nm, pulse duration - 10 ns, pulse repetition rate - 3.8 kHz, and pulse power density equal to 170 kW/cm2 has been used in the study. Nanoparticles in the form of colloids have been obtained and studied by visible range spectroscopy and optical microscopy. Obtained particles size is around 0.5 μm

    Democratization in a passive dendritic tree : an analytical investigation

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    One way to achieve amplification of distal synaptic inputs on a dendritic tree is to scale the amplitude and/or duration of the synaptic conductance with its distance from the soma. This is an example of what is often referred to as “dendritic democracy”. Although well studied experimentally, to date this phenomenon has not been thoroughly explored from a mathematical perspective. In this paper we adopt a passive model of a dendritic tree with distributed excitatory synaptic conductances and analyze a number of key measures of democracy. In particular, via moment methods we derive laws for the transport, from synapse to soma, of strength, characteristic time, and dispersion. These laws lead immediately to synaptic scalings that overcome attenuation with distance. We follow this with a Neumann approximation of Green’s representation that readily produces the synaptic scaling that democratizes the peak somatic voltage response. Results are obtained for both idealized geometries and for the more realistic geometry of a rat CA1 pyramidal cell. For each measure of democratization we produce and contrast the synaptic scaling associated with treating the synapse as either a conductance change or a current injection. We find that our respective scalings agree up to a critical distance from the soma and we reveal how this critical distance decreases with decreasing branch radius

    Integrated approach to radiodiagnosis of follicular thyroid neoplasia: a retrospective cohort trial

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    Background. An evidence-based diagnostic tactics for follicular thyroid gland neoplasia is lacking to date. First-line priority are radiography diagnostic techniques, which vary in capacities and therefore must be regulated in use.Objectives. An efficacy evaluation of multiparametric ultrasound (US), sonoelastography (SEG) and radionuclide scintigraphy (RS) in diagnosis of follicular thyroid neoplasms (FTN).Methods. Preoperative examination was interpreted in 222 FTN patients (86 with follicular thyroid adenoma, FTA, and 136 with follicular thyroid cancer, FTC) with subsequent surgery. A retrospective statistical data analysis was performed for B-mode US, colour Doppler imaging (CDI), power Doppler imaging (PDI), sonoelastography and Tc-99m pertechnetate scintigraphy.Results. Novel FTN descriptive evidence has been obtained. Particularly, an FTA vs. FTC trait comparison showed no reliable US marker of a node assignment to FTA or FTC. Trials of the national-manufactured TI-RADS system showed its good diagnostic potential: FTN sensitivity 89.55, specificity 77.58 and accuracy 83.52%. A SEG picture of FTN was typically motley-colour and mosaic. Young’s modulus in FTA was 27.5 ± 7.1 kPa, a higher stiffness (62.1 ± 12.1 kPa) in FTC indicated a higher likelihood of malignancy. Scintigraphy exhibited a modest capacity for FTN diagnosis (sensitivity 86.67, specificity 48.08 and accuracy 56.72%). AUC values (0.617) indicate its limited use for differential FTN diagnosis, mainly in hyperfunctioning nodules. Our experience elaborated an original algorithm for radiographic techniques application in FTN diagnosis.Conclusion. Several radiographic methods are warranted in suspected FTN. First-line is multiparametric US B-mode imaging to detect FTN priority markers and US symptom complexes. Sonoelastography is second-line in ambiguous cases to further clarify structure (stiffness) of the thyroid nodule examined. Unlike SEG, scintigraphy assesses the functional traits of thyroid nodule and so has limited indications, an important factor to consider in FTN

    Transcriptional dynamics of colorectal cancer risk associated variation at 11q23.1 correlate with tuft cell abundance and marker expression in silico

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    Colorectal cancer (CRC) is characterised by heritable risk that is not well understood. Heritable, genetic variation at 11q23.1 is associated with increased colorectal cancer (CRC) risk, demonstrating eQTL effects on 3 cis- and 23 trans-eQTL targets. We sought to determine the relationship between 11q23.1 cis- and trans-eQTL target expression and test for potential cell-specificity. scRNAseq from 32,361 healthy colonic epithelial cells was aggregated and subject to weighted gene co-expression network analysis (WGCNA). One module (blue) included 19 trans-eQTL targets and was correlated with POU2AF2 expression only. Following unsupervised clustering of single cells, the expression of 19 trans-eQTL targets was greatest and most variable in cluster number 11, which transcriptionally resembled tuft cells. 14 trans-eQTL targets were found to demarcate this cluster, 11 of which were corroborated in a second dataset. Intra-cluster WGCNA and module preservation analysis then identified twelve 11q23.1 trans-eQTL targets to comprise a network that was specific to cluster 11. Finally, linear modelling and differential abundance testing showed 11q23.1 trans-eQTL target expression was predictive of cluster 11 abundance. Our findings suggest 11q23.1 trans-eQTL targets comprise a POU2AF2-related network that is likely tuft cell-specific and reduced expression of these genes correlates with reduced tuft cell abundance in silico
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