1,166 research outputs found

    Genetic variability and structure of SNP haplotypes in the DMPK gene in Yakuts and other ethnic groups of northern Eurasia in relation to myotonic dystrophy

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    The genetic variability of the DMPK locus has been studied in relation to six SNP markers (rs2070736, rs572634, rs1799894, rs527221, rs915915, and rs10415988) in Yakuts with myotonic dystrophy (MD) in the Yakut population and in populations of northern Eurasia. Significant differences were observed in the allele frequencies between patients and a population sample of Yakuts for three SNP loci (rs915915, rs1799894, and rs0415988) associated with a high chance of disease manifestation. The odds ratios (OR) of MD development in representatives of the Yakut population for these three loci were 2.59 (95% CI, p = 0,004), 4.99 (95% CI, p = 0.000), and 3.15 (95% CI, p = 0.01), respectively. Haplotype TTTCTC, which is associated with MD, and haplotype GTCCTT, which was observed only in Yakut MD patients (never in MD patients of non-Yakut origin), were revealed. A low level of variability in the locus of DMRK gene in Yakuts (He = 0.283) compared with other examined populations was noted. An analysis of pairwise genetic relationships between populations revealed their significant differentiation for all the examined loci. In addition, a low level of differentiation in territorial groups of Yakut populations (FST = 0.79%), which was related to the high subdivision of the northern Eurasian population (FST = 11.83%), was observed

    The Challenge of Machine Learning in Space Weather Nowcasting and Forecasting

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    The numerous recent breakthroughs in machine learning (ML) make imperative to carefully ponder how the scientific community can benefit from a technology that, although not necessarily new, is today living its golden age. This Grand Challenge review paper is focused on the present and future role of machine learning in space weather. The purpose is twofold. On one hand, we will discuss previous works that use ML for space weather forecasting, focusing in particular on the few areas that have seen most activity: the forecasting of geomagnetic indices, of relativistic electrons at geosynchronous orbits, of solar flares occurrence, of coronal mass ejection propagation time, and of solar wind speed. On the other hand, this paper serves as a gentle introduction to the field of machine learning tailored to the space weather community and as a pointer to a number of open challenges that we believe the community should undertake in the next decade. The recurring themes throughout the review are the need to shift our forecasting paradigm to a probabilistic approach focused on the reliable assessment of uncertainties, and the combination of physics-based and machine learning approaches, known as gray-box.Comment: under revie

    Исследование биосенсорной реакции клеточных субстанций на излучение импульсного газоразрядного генератора для информацинно-волновой терапии

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    У роботі запропоновано використовувати в якості індикатора електромагнітного випромінювання міліметрового діапазону наднизької інтенсивності біологічну реакцію клітин в умовах in vitro. Об'єктом дослідження була суспензія клітин кісткового мозку щурів у фізіологічному розчині. Показано принципову можливість побудови біосенсорів на основі клітинних структур для реєстрації надслабкого випромінювання міліметрового діапазону.Introduction. The biological effects are characterized by a range of millimeter waves in the spectrum of electromagnetic radiation of high frequency. This is due to the fact that the membranes of living cells with dipole oscillate in the millimeter frequency range. The aim. The aim is cell structures using as biosensors of natural electromagnetic radiation in millimeter range with extremely low intensity for the energy and spectral characteristics evaluation of the discharge pulse generator for information-wave therapy. The experimental technique. The study was conducted «in vitro». The suspension of bone marrow cells of rats in saline was the object of irradiation. One of the cell suspensions was seen, as a control and the other three parts were subjected to irradiation of 10, 20 and 30 minutes. The relative number of dead cells was determined in the control sample and the sample irradiated at 30, 60 and 90 minutes as the characteristics of biosensor response. Results of the study. The relative number of dead cells in the irradiated sample is almost twice lower than for the control for all three exposures. Thus, the impact generated electro-magnetic radiation enhances the viability of bone marrow cells of rats. Conclusions. The experiments indirectly support the structure of the frequency spectrum of electromagnetic radiation discharge pulse generator. Also the theoretical possibility of biosensors constructing based on cell structures can be mentioned for registration superweak radiation in millimeter range.В работе предложено использовать в качестве индикатора электромагнитного излучения миллиметрового диапазона сверхнизкой интенсивности биологическую реакцию клеток в условиях in vitro. Объектом исследования была суспензия клеток костного мозга крыс в физиологическом растворе. Показано принципиальную возможность построения биосенсоров на основе клеточных структур для регистрации сверхслабого излучения миллиметрового диапазона

    ИСПОЛЬЗОВАНИЕ ФЛУОРИМЕТРИИ В БЛИЖНЕЙ ИК-ОБЛАСТИ С ФОТОГРАФИЧЕСКОЙ РЕГИСТРАЦИЕЙ СИГНАЛА В МЕТОДЕ «ОТПЕЧАТКОВ ПАЛЬЦЕВ» С ДОБАВКОЙ ФЛУОРОФОРА К ОБЪЕКТУ: ДИСКРИМИНАЦИЯ ЯБЛОЧНЫХ СОКОВ

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    The application of dyes, that fluoresce in the near infrared (NIR, 700-800 nm) region, for the recognition of samples using a fingerprinting method with the addition of fluorophores to the samples (“fluorescent eye”) is proposed. The technique has been successfully applied to the classification of samples of various nature. In the current work, this strategy has been tested on the example of discrimination of 17 samples of apple juice from different manufacturers, purchased at different times. An indolenine series heptamethine carbocyanine dye in the presence of surfactants was used as the added fluorophore, red LEDs were used as an excitation source, and the signal was recorded using a digital camera with an additional IR filter installed; a spectrofluorimeter with a 96-well plate accessory was used to record the spectra. Photographic images were processed using Unscrambler X and Excel software. The results were presented using the following coordinates: intensity of NIR fluorescence - intensity of visible light reflection (using the photographic images). It was found that such presentation allowed the samples to be divided into groups associated with the manufacturer. We have also obtained intrinsic fluorescence spectra, including those with the addition of NIR dye, and these results were processed by the principal component analysis. It was possible to distinguish 5–6 groups of samples by their intrinsic emission, not counting the blank, while the spectra with the addition of the dye allowed to isolate the largest number of groups of samples (9). At the same time, the classification using spectra did not allow juices to be grouped by the producer. Also, obtaining photographs using a visualizer was easier and faster than recording the fluorescence spectra. The joint processing of emission spectra and photographs did not improve the quality of discrimination.Keywords: fingerprinting method, NIR fluorimetry, apple juice, principal component analysisDOI: http://dx.doi.org/10.15826/analitika.2022.26.1.005E.V. Skorobogatov, I.A. Stepanova, V.S. Orekhov, M.K. Beklemishev Department of Chemistry, Lomonosov Moscow State University, Russin Federation, 119991, GSP-1, Moscow, Leninskie gory, 1, building 3Предложено использовать красители, флуоресцирующие в ближней ИК (БИК) области спектра (700–800 нм), для распознавания объектов методом «отпечатков пальцев», основанным на добавке флуорофоров к объекту («флуоресцентный глаз»). Метод успешно применяется в классификации объектов различной природы. В данной работе метод опробован на примере дискриминации 17 образцов яблочного сока разных производителей, выпущенных в разное время. В качестве добавляемого флуорофора использовали гептаметиновый карбоцианиновый краситель индоленинового ряда в присутствии ПАВ, в качестве источника излучения – красные светодиоды, а сигнал регистрировали с помощью цифрового фотоаппарата с дополнительным ИК-светофильтром; для записи спектров применяли спектрофлуориметр с приставкой для 96-луночного флуориметрического планшета. Фотографические изображения обрабатывали с помощью стандартного программного обеспечения Unscrambler X и Excel. Результаты представили в координатах: интенсивность БИК-флуоресценции – интенсивность отражения видимого света (с использованием соответствующих фотографий). Обнаружили, что такое представление позволяет разделить образцы на группы, связанные с производителем. Получали также спектры собственной флуоресценции, в том числе с добавкой БИК-красителя, обрабатывая эти результаты методом главных компонент. По собственной эмиссии можно выделить 5–6 групп образцов, не считая контрольного, тогда как по спектрам с добавкой красителя удается добиться выделения наибольшего числа групп образцов (девять). При этом классификация с использованием спектров не позволяет группировать соки по производителям. Кроме того, получение фотографий с помощью визуализатора проще и экспресснее, чем регистрация спектров флуоресценции. Совместная обработка эмиссионных спектров и фотографий не позволяет повысить качество дискриминации образцов.Ключевые слова: метод «отпечатков пальцев», флуориметрия в ближней ИК-области, яблочный сок, метод главных компонентDOI: http://dx.doi.org/10.15826/analitika.2022.26.1.00

    Численное моделирование влияния вдува газа на эффективность работы устройства без-машинного энергоразделения

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    The paper considers numerical simulation of a non-machine energy separation device with a porous inner tube. The results obtained show that with a flow rate variation up to 30% of general rate the channel efficiency of gas-dynamic non-machine device for energy separation falls by 3-5%. Hence, a heat efficiency loss due to the colder air injection prevails over the increase of heat flow resulting from a recovery factor decrease when the temperature difference between supersonic and subsonic flows rises. So, the use of gas injection (porous inner tube) to improve the efficiency of the non-machine device for energy separation is beside the purpose.The effect when the temperature changes its sign in the non-machine device for energy separation and supersonic flow becomes cooler while a subsonic one is heated has been also simulated. This effect was previously obtained experimentally.The numerical simulation has shown good coincidence with analytical solution in case of the laminar flow regime. The research has shown that with the laminar flow the efficiency of the non-machine device for energy separation can be significantly higher than with the turbulent flow, but its implementation is quite difficult.Представленная статья рассматривает численное моделирование устройства газодинамического безмашинного энергоразделения с внутренней пористой трубой. Полученные результаты показывают, что эффективность устройства газодинамического безмашинного энергоразделения в случае перепуска газа падает (на 3-5 %) при перепуске до 30 %. Отсюда следует, что потеря тепловой эффективности из-за вдува более холодного воздуха превалирует над увеличением теплового потока за счет уменьшения коэффициента восстановления, когда увеличивается разность температур между сверхзвуковым и дозвуковым потоками. Таким образом, использование перепуска (пористой стенки) для улучшения работы устройства нецесообразно.Также получено, что в устройстве газодинамического безмашинного энергоразделения эффект может меняет “знак”: сверхзвуковой поток – охлаждается, а дозвуковой – нагревается.Также численное моделирование показало хорошее совпадение с аналитическим решением при ламинарном режиме течения. Показано, что в случае ламинарного режима течения эффективность устройства газодинамического безмашинного энергоразделения может быть значительно выше, но реализовать это достаточно сложно

    Low-temperature spin relaxation in n-type GaAs

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    Low-temperature electron spin relaxation is studied by the optical orientation method in bulk n-GaAs with donor concentrations from 10^14 cm^{-3} to 5x10^17 cm^{-3}. A peculiarity related to the metal-to-insulator transition (MIT) is observed in the dependence of the spin lifetime on doping near n_D = 2x10^16 cm^{-3}. In the metallic phase, spin relaxation is governed by the Dyakonov-Perel mechanism, while in the insulator phase it is due to anisotropic exchange interaction and hyperfine interactio

    Ethylene supports colonization of plant roots by the mutualistic fungus Piriformospora indica

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    The mutualistic basidiomycete Piriformospora indica colonizes roots of mono- and dicotyledonous plants, and thereby improves plant health and yield. Given the capability of P. indica to colonize a broad range of hosts, it must be anticipated that the fungus has evolved efficient strategies to overcome plant immunity and to establish a proper environment for nutrient acquisition and reproduction. Global gene expression studies in barley identified various ethylene synthesis and signaling components that were differentially regulated in P. indica-colonized roots. Based on these findings we examined the impact of ethylene in the symbiotic association. The data presented here suggest that P. indica induces ethylene synthesis in barley and Arabidopsis roots during colonization. Moreover, impaired ethylene signaling resulted in reduced root colonization, Arabidopsis mutants exhibiting constitutive ethylene signaling, -synthesis or ethylene-related defense were hyper-susceptible to P. indica. Our data suggest that ethylene signaling is required for symbiotic root colonization by P. indica

    Comparative Analysis of the Pathogen Structure in Patients with Community-Acquired and Nosocomial Pneumonia in Medical Organizations of the Rostov, Tyumen Regions and Khabarovsk Territory at the Current Stage of a New Coronavirus Infection Pandemic

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    The aim of the study was to conduct a comparative analysis of the spectrum and antibiotic resistance of secondary pneumonia pathogens isolated in the territories of the Rostov, Tyumen Regions and Khabarovsk Territory against the background of a new coronavirus infection pandemic.Materials and methods. We investigated sputum samples from coronavirus-positive and coronavirus-negative patients with community-acquired pneumonia from medical organizations using bacteriological method, PCR mass spectrometry.Results and discussion. The study of the etiological structure of secondary pneumonia agents isolated from patients in medical organizations of the Southern, Ural and Far Eastern Federal Districts has revealed that the dominant cultures in SARS‑CoV‑2 “+” and SARS‑CoV‑2 “–” patients were yeast and yeast-like fungi. It has been found that under diversity of isolated fungi, Candida albicans species prevailed. The bacterial microflora is represented by a variety of gram-positive and gram-negative bacteria, of which Staphylococcus aureus and Klebsiella pneumoniaе were most often present in sputum. It has also been established that even before hospitalization of patients, community-acquired pneumonia could be caused by microorganisms of the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniaе, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.), which are usually considered as polyantibiotic-resistant pathogens of nosocomial infections. Moreover, in coronavirus-positive patients with secondary community-acquired pneumonia, those pathogens were isolated 2–3 times more frequently than in coronavirus-negative ones. Assessment of sensitivity/resistance of isolated strains to antibacterial drugs has revealed a general trend: the majority of the strains, regardless of the type, were characterized by a narrow spectrum of sensitivity, having 3 or more markers of antibiotic resistance. This confirms the necessity and expediency of microbiological support of the patient during the entire infectious process. The most adequate drugs of choice, providing activity against 60–70 % of strains of the Enterobacteriaceae family, are amikacin and cefoperazone/sulbactam

    Determining significance of pairwise co-occurrences of events in bursty sequences

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    <p>Abstract</p> <p>Background</p> <p>Event sequences where different types of events often occur close together arise, e.g., when studying potential transcription factor binding sites (TFBS, events) of certain transcription factors (TF, types) in a DNA sequence. These events tend to occur in bursts: in some genomic regions there are more genes and therefore potentially more binding sites, while in some, possibly very long regions, hardly any events occur. Also some types of events may occur in the sequence more often than others.</p> <p>Tendencies of co-occurrence of binding sites of two or more TFs are interesting, as they may imply a co-operative role between the TFs in regulatory processes. Determining a numerical value to summarize the tendency for co-occurrence between two TFs can be done in a number of ways. However, testing for the significance of such values should be done with respect to a relevant null model that takes into account the global sequence structure.</p> <p>Results</p> <p>We extend the existing techniques that have been considered for determining the significance of co-occurrence patterns between a pair of event types under different null models. These models range from very simple ones to more complex models that take the burstiness of sequences into account. We evaluate the models and techniques on synthetic event sequences, and on real data consisting of potential transcription factor binding sites.</p> <p>Conclusion</p> <p>We show that simple null models are poorly suited for bursty data, and they yield many false positives. More sophisticated models give better results in our experiments. We also demonstrate the effect of the window size, i.e., maximum co-occurrence distance, on the significance results.</p
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