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Regular version of the site
Of all publications in the section: 583
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Article
Pianykh O., Pospelova K., Kamboj N. Journal of Digital Imaging. 2018. Vol. 31. No. 6. P. 768-775.

Humans can determine image quality instantly and intuitively, but the mechanism of human perception of image quality is unknown. The purpose of this work was to identify the most important quantitative metrics responsible for the human perception of digital image quality. Digital images from two different datasets—CT tomography (MedSet) and scenic photographs of trees (TreeSet)—were presented in random pairs to unbiased human viewers. The observers were then asked to select the best-quality image from each image pair. The resulting human-perceived image quality (HPIQ) ranks were obtained from these pairwise comparisons with two different ranking approaches. Using various digital image quality metrics reported in the literature, we built two models to predict the observed HPIQ rankings, and to identify the most important HPIQ predictors. Evaluating the quality of our HPIQ models as the fraction of falsely predicted pairwise comparisons (inverted image pairs), we obtained 70–71% of correct HPIQ predictions for the first, and 73–76%for the second approach. Taking into account that 10–14% of inverted pairs were already present in the original rankings, limitations of the models, and only a few principal HPIQ predictors used, we find this result very satisfactory. We obtained a small set of most significant quantitative image metrics associated with the human perception of image quality. This can be used for automatic image quality ranking, machine learning, and quality-improvement algorithms.

Added: Feb 5, 2019
Article
Kelbert M., Sazonov I., Bocharov G. et al. Mathematical Modelling of Natural Phenomena. 2017. Vol. 12. No. 5. P. 63-77.

Many human infections with viruses such as human immunode ciency virus type 1 (HIV{1) are characterized by low numbers of founder viruses for which the random effects and discrete nature of populations have a strong effect on the dynamics, e.g., extinction versus spread. It remains to be established whether HIV transmission is a stochastic process on the whole. In this study, we consider the simplest (so-called, 'consensus') virus dynamics model and develop a computational methodology for building an equivalent stochastic model based on Markov Chain accounting for random interactions between the components. The model is used to study the evolution of the probability densities for the virus and target cell populations. It predicts the probability of infection spread as a function of the number of the transmitted viruses. A hybrid algorithm is suggested to compute efficiently the dynamics in state space domain characterized by a mix of small and large species densities.

Added: Oct 21, 2017
Article
Cepeda J. A., Niccolai L. M., Eritsyan K. et al. Drug and Alcohol Dependence. 2013. Vol. 132. No. 3. P. 571-579.

Background

In Russia, injection drug use and transmission of blood-borne pathogens such as human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are inextricably linked, however the burden of alcohol use remains unexplored among injection drug users (IDUs).

Methods

Individuals who were 18 years of age and older and had injected drugs in the previous 30 days were recruited in the cities of Novosibirsk and Ivanovo by respondent driven sampling. Consenting individuals were administered a quantitative survey instrument and provided blood samples for serological testing.

Results

In Novosibirsk and Ivanovo, 29% and 35% of respondents were categorized as moderate/heavy drinkers respectively. Individuals reported problems related to alcohol use that affected their physical health (23%), family (55%), and induced financial hardships (43%). In the multivariate analysis, we found that methamphetamine injection in the past 12 months was a strong and significant correlate of moderate/heavy drinking in Novosibirsk (aOR = 5.63 95% CI: [1.01–31.47]) and Ivanovo (aOR = 3.81 95% CI [2.20–6.62]). There was poor agreement between self-reported HCV status and HCV test results (kappa = −0.05 and 0.26 in Novosibirsk and Ivanovo respectively). IDUs who correctly knew their HCV seropositive status in Novosibirsk and IDUs who correctly knew their HCV seronegative status in Ivanovo were significantly more likely to be moderate/heavy drinkers.

Conclusion

Alcohol use is problematic among IDUs who are at high risk for HCV. Future interventions should target IDUs who are moderate/heavy drinkers in order to prevent liver complications resulting from HCV infection.

Added: Mar 12, 2018
Article
Рубцов Ю. П., Goryunov K., Romanov A. et al. Stem Cells International. 2017. P. 1-16.
Added: Apr 10, 2019
Article
Kvasha E. A., Kharkova T. L., Yumaguzin V. Демографическое обозрение. 2014. No. 5. P. 85-108.

The article discusses long-term mortality trends (since 1956) from external causes of death in Russia. Russia has long lagged behind developed countries in this domain. The level of mortality from external causes of death remains high and its structure is still archaic with large contribution of homicides, alcohol poisoning and injuries of undetermined intent.

Excess number of deaths from life tables of Russia and Western European countries is compared. It is shown that in Russia the greatest excess losses are associated with mortality from poisonings among both sexes, suicide among men and homicide among women.

Mortality from external causes, along with mortality from diseases of the circulatory system, has had a significant impact on life expectancy. In general, over the period 1956-2012 the increase in mortality from external causes in the 15-64 age group reduced life expectancy by 2.6 years for males and 0.7 years for females.

The decline, starting in 2003, of mortality from external causes of death has slightly reduced the gap between Russia and developed countries, bringing the current Russian level closer to those levels reached in Russia in the mid-1960s and 1980s. However, given the fluctuations of mortality from external causes, it is premature to say whether the current decline in mortality is robust.

 

Added: Feb 14, 2016
Article
Kvasha E. A. Демографическое обозрение. 2014. No. 5. P. 69-84.

Infant mortality in Russia has been decreasing for several decades. In 2011, however, Russia’s infant mortality rate reached a level (7.4 per 1000 live births) more than three times higher than in countries with minimal levels. In April 2012, Russia adopted new definitions of live births and stillbirths, which are much closer to the corresponding WHO definitions than those used before. The transition to these new definitions was meant to increase the rates of perinatal, early neonatal and infant mortality in general for children weighing up to 1000 grams – those concerned by the changed definition. This paper analyzes the changes in the structure and dynamics of death in children under one year of age since the transition to the new definitions of live births and stillbirths, according to birth weight and period of death based on official and medical statistics. It looks at the possibility of distortion of both infant and perinatal mortality and their components. Particular attention is given to an analysis of the structure of infant mortality by age and cause of death in Russia in comparison with other countries. The regional aspect of changes in infant mortality for 2011-2012 is also studied herein.

Added: May 31, 2016
Article
Shaposhnikov D., Revich B., Bellander T. et al. Epidemiology. 2014. Vol. 25. No. 3. P. 359-364.

Prolonged high temperatures and air pollution from wildfires often occur together, and the two may interact in their effects on mortality. However, there are few data on such possible interactions.

Methods: We analyzed day-to-day variations in the number of deaths in Moscow, Russia, in relation to air pollution levels and temperature during the disastrous heat wave and wildfire of 2010. Corresponding data for the period 2006-2009 were used for comparison. Daily average levels of PM10 and ozone were obtained from several continuous measurement stations. The daily number of nonaccidental deaths from specific causes was extracted from official records. Analyses of interactions considered the main effect of temperature as well as the added effect of prolonged high temperatures and the interaction with PM10

 

Added: Mar 20, 2014
Article
Nazarova M., Piradov M. A., Novikov P. et al. European Journal of Neurology, Supplement. 2015. Vol. 22. No. S1. P. 34-35.

Hand motor recovery prognosis in stroke patients is crucial to develop a realistic individual rehabilitation plan. The aim of this study was to perform a multimodal assessment in chronic ischemic stroke patients and to compare predictive role of corticospinal tract (CST) integrity measured by diffusion tensor imaging (DTI) and navigated TMS (nTMS), and functional condition of the motor cortex measured by functional MRI (fMRI) and multi-muscle nTMS cortical mapping for hand motor recovery.Total of 30 patients with the only chronic supratentorial ischemic stroke and various severity of hand paresis were enrolled (12 females, medium age 50,0±8,0). The assessment included fractional anisotropy FA (index, %) measurement in internal capsule (ic), cerebral peduncle (pc) and pons. Functional assessment included analysis of BOLD response induced by passive motor task, assessment of intracortical inhibition (SICI) and intracortical facilitation (ICF) phenomena in Abductor Pollicis Brevis (APB) and nTMS mapping of APB and Extensor Digitorum Communis (EDC) cortical representations in both hemispheres. A group of 14 healthy volunteers (7 females, mean age 36,6±15,2) completed fMRI and nTMS investigation. A strong correlation between clinical outcome and FA let to consider FA as an available clinical measurement for hand motor prognosis. Significantly higher disinhibition in the unaffected hemisphere (UH) in well recovered and normal SICI in the UH in poorly recovered patients allow to suppose that interhemispheric interaction might change extensively by chronic phase. A software for multi-muscle nTMS mapping was developed, though this approach need deeper exploration.

Added: Feb 17, 2017
Article
Kulikova S., Hertz-Pannier L., Dehaene-Lambertz G. et al. Brain Structure and Function. 2015. Vol. 220. No. 6. P. 3657-3672.

In vivo evaluation of the brain white matter maturation is still a challenging task with no existing gold standards. In this article we propose an original approach to evaluate the early maturation of the white matter bundles, which is based on comparison of infant and adult groups using the Mahalanobis distance computed from four complementary MRI parameters: quantitative qT1 and qT2 relaxation times, longitudinal λ║ and transverse λ⊥ diffusivities from diffusion tensor imaging. Such multi-parametric approach is expected to better describe maturational asynchrony than conventional univariate approaches because it takes into account complementary dependencies of the parameters on different maturational processes, notably the decrease in water content and the myelination. Our approach was tested on 17 healthy infants (aged 3- to 21-week old) for 18 different bundles. It finely confirmed maturational asynchrony across the bundles: the spino-thalamic tract, the optic radiations, the cortico-spinal tract and the fornix have the most advanced maturation, while the superior longitudinal and arcuate fasciculi, the anterior limb of the internal capsule and the external capsule have the most delayed maturation. Furthermore, this approach was more reliable than univariate approaches as it revealed more maturational relationships between the bundles and did not violate a priori assumptions on the temporal order of the bundle maturation. Mahalanobis distances decreased exponentially with age in all bundles, with the only difference between them explained by different onsets of maturation. Estimation of these relative delays confirmed that the most dramatic changes occur during the first post-natal year.

Added: Oct 22, 2015
Article
Kozintseva E., Dragoy O., Malyutina S. et al. Steam-, Spreak- en Taalpathologie. 2013. Vol. 18. P. 98-99.

Key characteristics of non-fluent (Broca, motor) aphasia are, among others, verb finding difficulties and effortful speech output. These characteristics are related to different levels of speech production (lexical retrieval and motor execution). This study was aimed at identifying patterns of its reorganization depending on the locus of the linguistic deficit in patients with non-fluent aphasia.

Added: Nov 16, 2013
Article
Shchekotikhin A., Glazunova V.A., Dezhenkova L. et al. Bioorganic and Medicinal Chemistry. 2007. Vol. 15. No. 7. P. 2651-2659.

The efficacy of anthracycline based anticancer drugs is limited by pleiotropic drug resistance of tumor cells. Aiming at the design of anthracyclinone congeners capable of circumventing drug resistance, we synthesized naphthoindole containing derivatives of tryptophan and tryptamine. In doing so we adapted the traditional, gramine based approach for tryptophan and tryptamine synthesis. The most potent new compound, 3-(2-aminoethyl)-4,11-dihydroxynaphtho[2,3-f]indole-5,10-dione (16), was equally cytotoxic (IC50 within low micromolar concentrations) for human K562 leukemia and HCT116 colon carcinoma cell lines and their isogenic sublines with genetically defined determinants of altered drug response, that is, the expression of the multidrug transporter P-glycoprotein and loss of pro-apoptotic p53. Each of these mechanisms conferred resistance to the reference drug adriamycin. In contrast, naphthotryptamine 16, although less potent than adriamycin, was equally toxic for wild type cell lines and drug resistant counterparts. Moreover, at 3-5 μM 16 inhibited topoisomerase I in vitro. Thus, our novel naphthoindole based derivative of tryptamine gained new activities important for anticancer therapy, namely, suppression of topoisomerase I and the ability to overcome resistance mediated by P-glycoprotein expression and p53 dysfunction. 

Added: Jul 9, 2015
Article
Nikolai Novitski, Huotilainen M., Tervaniemi M. et al. Clinical Neurophysiology. 2007. Vol. 118. P. 412-419.
The precision of sound frequency discrimination in newborn infants in the 250–4000-Hz frequency range was determined using the neonatal electrophysiological mismatch response (MMR), the infant equivalent of adult mismatch negativity (MMN). The electroencephalogram (EEG) was recorded in 11 full-term sleeping newborn infants mostly in active sleep (67% of the time). Pure tones were presented through loudspeakers in an oddball paradigm with a 800-ms stimulus onset asynchrony (SOA). Each stimulus block contained a standard (p = 0.76) of 250, 1000, or 4000 Hz in frequency (in separate blocks) and deviants with a frequency change of either 5% or 20% of the standard (p = 0.12 of each). A positive ERP deflection was found at 200–300 ms from stimulus onset in response to the 20% deviation from the 250, 1000, and 4000 Hz standard frequencies. The amplitude of the response in the 200–300 ms time window was significantly larger for the 20% than 5% deviation. We observed in newborn infants automatic frequency discrimination as reflected by a positive MMR. The newborns were able to discriminate frequency change of 20% in the 250–4000-Hz frequency range, whereas the discrimination of the 5% frequency change was not statistically confirmed. The present data hence suggest that the neonatal frequency discrimination has lower resolution than that in adult and older children data.
Added: Jul 10, 2015
Article
Rykov Y., Meylakhs P., Sinyavskaya Y. American Behavioral Scientist. 2017. Vol. 61. No. 7. P. 688-706.

With rapid growth of online social network sites, the issue of health-related online communities and its social and behavioral implications has become increasingly important for public health. Unfortunately, online communities often become vehicles for promotion of pernicious misinformation, in particular, that HIV virus is a myth (AIDS denialism). This study seeks to explore online users’ behavior and interactions within AIDS-denialist community to identify and estimate the number of those, who potentially are most susceptible to AIDS-denialist arguments—“the risk group” in terms of becoming AIDS denialists. Social network analysis was used for examining the most numerous AIDS-denialist community (over 15,000 members) in the most popular Russian SNS “VK.com.” In addition, content analysis was used for collecting data on attitudes toward AIDS-denialist arguments and participants’ self-disclosed HIV status. Two data sets were collected to analyze friendship ties and communication interactions among community members. We have identified the core of online community—cohesive and dedicated AIDS denialists, and the risk group: users who communicate with core members, and, thus, can be more susceptible to the AIDS-denialist propaganda and their health behaviors (e.g., refusing treatment). Analysis allowed to significantly reduce the target audience for possible intervention campaigns and simultaneously increase the accuracy of determining the risk group composition.

Added: Apr 18, 2017
Article
Shtyrov Y. The Neuroscientist. 2012. Vol. 18. No. 4. P. 312-319.

Humans are unique in developing large lexicons as their communication tool; to achieve this, they are able to learn new words rapidly. However, neural bases of this rapid learning, which may be an expression of a more general cognitive mechanism likely rooted in plasticity at cellular and synaptic levels, are not yet understood. In this update, the author highlights a selection of recent studies that attempted to trace word learning in the human brain noninvasively. A number of brain areas, most notably in hippocampus and neocortex, appear to take part in word acquisition. Critically, the currently available data not only demonstrate the hippocampal role in rapid encoding followed by slow-rate consolidation of cortical word memory traces but also suggest immediate neocortical involvement in the word memory trace formation. Echoing early behavioral studies in ultra-rapid word learning, the reviewed neuroimaging experiments can be taken to suggest that our brain may effectively form new cortical circuits online, as it gets exposed to novel linguistic patterns in the sensory input.

Added: Oct 23, 2014
Article
Egorova N., Pulvermuller F., Shtyrov Y. Brain Topography. 2014. Vol. 27. No. 3. P. 375-392.

The neurobiological basis and temporal dynamics of communicative language processing pose important yet unresolved questions. It has previously been suggested that comprehension of the communicative function of an utterance, i.e. the so-called speech act, is supported by an ensemble of neural networks, comprising lexico-semantic, action and mirror neuron as well as theory of mind circuits, all activated in concert. It has also been demonstrated that recognition of the speech act type occurs extremely rapidly. These findings however, were obtained in experiments with insufficient spatio-temporal resolution, thus possibly concealing important facets of the neural dynamics of the speech act comprehension process. Here, we used magnetoencephalography to investigate the comprehension of Naming and Request actions performed with utterances controlled for physical features, psycholinguistic properties and the probability of occurrence in variable contexts. The results show that different communicative actions are underpinned by a dynamic neural network, which differentiates between speech act types very early after the speech act onset. Within 50-90 ms, Requests engaged mirror-neuron action-comprehension systems in sensorimotor cortex, possibly for processing action knowledge and intentions. Still, within the first 200 ms of stimulus onset (100-150 ms), Naming activated brain areas involved in referential semantic retrieval. Subsequently (200-300 ms), theory of mind and mentalising circuits were activated in medial prefrontal and temporo-parietal areas, possibly indexing processing of intentions and assumptions of both communication partners. This cascade of stages of processing information about actions and intentions, referential semantics, and theory of mind may underlie dynamic and interactive speech act comprehension.

Added: Oct 23, 2014
Article
Koukouli F., Rooy M. E., Tziotis D. et al. Nature Medicine. 2017. Vol. 23. No. 3. P. 347.

The prefrontal cortex (PFC) underlies higher cognitive processes1 that are modulated by nicotinic acetylcholine receptor (nAChR) activation by cholinergic inputs2 . PFC spontaneous default activity3 is altered in neuropsychiatric disorders4 , including schizophrenia5 —a disorder that can be accompanied by heavy smoking6 . Recently, genome-wide association studies (GWAS) identified single-nucleotide polymorphisms (SNPs) in the human CHRNA5 gene, encoding the α5 nAChR subunit, that increase the risks for both smoking and schizophrenia7,8. Mice with altered nAChR gene function exhibit PFC-dependent behavioral deficits9–11, but it is unknown how the corresponding human polymorphisms alter the cellular and circuit mechanisms underlying behavior. Here we show that mice expressing a human α5SNP exhibit neurocognitive behavioral deficits in social interaction and sensorimotor gating tasks. Two-photon calcium imaging in awake mouse models showed that nicotine can differentially influence PFC pyramidal cell activity by nAChR modulation of layer II/III hierarchical inhibitory circuits. In α5- SNP-expressing and α5-knockout mice, lower activity of vasoactive intestinal polypeptide (VIP) interneurons resulted in an increased somatostatin (SOM) interneuron inhibitory drive over layer II/III pyramidal neurons. The decreased activity observed in α5-SNP-expressing mice resembles the hypofrontality observed in patients with psychiatric disorders, including schizophrenia and addiction5,12. Chronic nicotine administration reversed this hypofrontality, suggesting that administration of nicotine may represent a therapeutic strategy for the treatment of schizophrenia, and a physiological basis for the tendency of patients with schizophrenia to self-medicate by smoking13.

Added: Mar 29, 2018
Article
Novatorov E. V. Managerial Marketing eJournal. 2014. Vol. 6. No. 46. P. 31-60.

The author deconstructs the prevailing controversial conceptualization of nonprofit marketing and concludes it rests on three principles: voluntary exchange, an open system organization, and self-interest motivation. Negative case analysis of these principles revealed that alternative principles were ignored in the social science literature. Based on a qualitative analysis a revised conceptualization of non-profit marketing was suggested which incorporated the principles of redistribution and reciprocity, the features of a closed model of formal organization, and public interest motivation. The critical theory approach to the study used non-empirical procedures that included negative case analysis. The paper presents results of negative case analysis.

Added: Nov 11, 2014
Article
Samatov T. R., Galatenko V. V., Block A. et al. Seminars in Cancer Biology. 2016.

The major issues hampering progress in the treatment of cancer patients are distant metastases and drug resistance to chemotherapy. Metastasis formation is a very complex process, and looking at gene signatures alone is not enough to get deep insight into it. This paper reviews traditional and novel approaches to identify gene signature biomarkers and intratumoural fluid pressure both as a novel way of creating predictive markers and as an obstacle to cancer therapy. Finally recently developed in vitro systems to predict the response of individual patient derived cancer explants to chemotherapy are discussed.

Added: Oct 2, 2016
Article
Vasilyeva S., Kuznetsova A., Khalyavina J. et al. Nucleosides, Nucleotides and Nucleic Acids. 2014. Vol. 33. No. 9. P. 615-625.

A series of novel fluorescent pyrimidine nucleosides containing 2,1,3-benzoxadiazole or naphtho[1,2,3-cd]indole-6 (2h)-one fragments was designed and synthesized. Introduction of fluorescent fragments into the position 5 of the uridine or cytidine heterocycle was carried out in two ways: by Sonogashira Coupling Reaction and CuI-catalyzed cycloaddition ("click" reaction). The obtained nucleoside derivatives became fluorescent due to the inserted fragments. The excitation wavelength (440-450 nm) was outside the absorption band of many biomolecules and significantly differed from the emission wavelength (560-600 nm). In addition, the intended nucleoside analogs were shown to kill cultured human tumor cells at submicromolar concentrations

Added: Jul 14, 2015
Article
Korsakov I. N., Kuptsov S. M., Raznometov D. A. et al. International Journal of Advanced Trends in Computer Science and Engineering. 2013. Vol. 2. No. 5. P. 35-40.

Abstract :Telehealth systems demand standardized solutions to be cost effective and to take advantage of middleware operation and interoperability. The plug-&-play and standard-based platform that, either as individual elements or as components, can be incorporated in a simple way into different homecare environments.Many company, not traditionally involved in medical markets, increasing pressure for a standard for Personal Health Devices (PHD). As a result: ISO/IEEE11073 (X73) standards is adapting from Intensive Unit Care (ICU) scope, focused on the Point-Of-Care (PoC), to Personal Health Devices (PHD), focused on ubiquitous environments, implementing high quality sensors, supporting wireless technologies and providing a faster and more reliable communication network resources. This X73-PHD version is for the homecare challenge and might appear the best-positioned international standards to reach this goal. In this article, a X73 compliant agentand manager communication for homecare platform, as a proof of concept, will be explaining all steps implemented as well as on demand agent specific protocol plugins downloaded to X73 Manager.

Added: Mar 20, 2014
Article
Savinskaya O. Qualitative Report. 2016. Vol. 21. No. 1. P. 68-70.

In ‘Doing mental health research with children and adolescents. A Guide to qualitative Methods’ (2014), Michell O’Really and Nicola Parker present a highly practical guide to conduct qualitative research with children what extremely easy to follow. The authors show a research process step-by-step with special attention to communicative, ethical and legal issues. The guide is provided by overview of the theories, the importance of research for evidence construction, and most popular qualitative data collection and analysis techniques. In the last chapter, authors discover the successful practice of knowledge dissemination.

Added: Oct 30, 2015