20 research outputs found

    GLL-based Context-Free Path Querying for Neo4j

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    We propose GLL-based context-free path querying algorithm which handles queries in Extended Backus-Naur Form (EBNF) using Recursive State Machines (RSM). Utilization of EBNF allows one to combine traditional regular expressions and mutually recursive patterns in constraints natively. The proposed algorithm solves both the reachability-only and the all-paths problems for the all-pairs and the multiple sources cases. The evaluation on realworld graphs demonstrates that utilization of RSMs increases performance of query evaluation. Being implemented as a stored procedure for Neo4j, our solution demonstrates better performance than a similar solution for RedisGraph. Performance of our solution of regular path queries is comparable with performance of native Neo4j solution, and in some cases our solution requires significantly less memory

    Mathematical programming in Mathcad and Mathematica

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    An article generalizes the long-term work of authors with packages of applied mathematical programs. It discusses and demonstrates the features and methods of solution of mathematical tasks in mathematical package Mathcad and Mathematica: from the simplest ones, included in the set of typical problems of mathematical disciplines for training specialists for shipbuilding, to complex computational tasks and applied problems of professional orientation, which require the construction of a mathematical model and analysis of the results obtained. The examples show the solution of mathematical problems in symbolic form, mathematical studies in the Mathcad and Mathematica environment, and mathematical programming with these packages

    Dynamics of collective modes in an unconventional charge density wave system BaNi2As2

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    BaNi 2As 2 is a non-magnetic analogue of BaFe2 As2 , the parent compound of a prototype pnictide high-temperature superconductor, displaying superconductivity already at ambient pressure. Recent diffraction studies demonstrated the existence of two types of periodic lattice distortions above and below the triclinic phase transition, suggesting the existence of an unconventional charge-density-wave (CDW) order. The suppression of CDW order upon doping results in a sixfold increase in the superconducting transition temperature and enhanced nematic fluctuations, suggesting CDW is competing with superconductivity. Here, we apply time-resolved optical spectroscopy to investigate collective dynamics in BaNi 2 As 2. We demonstrate the existence of several CDW amplitude modes. Their smooth evolution through the structural phase transition implies the commensurate CDW order in the triclinic phase evolves from the high-temperature unidirectional incommensurate CDW, and may indeed trigger the structural phase transition. Excitation density dependence reveals excep- tional resilience of CDW against perturbation, implying an unconventional origin of the underlying electronic instability

    ABOUT NON-TRADITIONAL FEED ADDITIVES INFLUENCE ON SAFETY OF THE YAKUT BREED HORSES LIVE WEIGHT

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    Horse breeding is one of the rapidly developing branches of animal husbandry in Yakutia. Horses of the Yakut breed are only type of farm animals that are kept year-round in harsh conditions of the sharply continental climate of Yakutia. In winter, animals experience a significant lack of nutrients and minerals. This is due to fact that basic diet consists of natural feed winter pasture and hay. Therefore, the goal was to study the effect of complex feed additives from local natural raw materials on the change in live weight and biochemical composition of the blood of animals. This study used standard animal research methods. The use of non-traditional feed additives in feeding of horses contributed to an increase in the supply of nutrients and minerals to the rations. Improving feeding conditions affected the live weight of horses (live weight loss was 5.75 % и 5.45 %). The change caused by inclusion of non-traditional feed additives in the diets of horses had a positive effect on the morphological and biochemical composition of the blood animals. In horses from the experimental groups, an increase was found in the blood in total protein by 0.50 % and 0.30 %, albumin by 0.36 and 0.20 %, globulin by 0.13 and 0.10 %, hemoglobin by 2.91 and 1.33 %, calcium by 3.56 and 1.29%, phosphorus by 5.71 and 1.90 %. Thus, use of experimental non-traditional feed additives in feeding horses in winter contributes to the best preservation of live weight. This is due to the improvement of mineral and vitamin nutrition in a difficult period of deficiency of macro- and microelements, vitamins in the diets of horses. This improves metabolism, which is reflected in the morphological and biochemical composition of blood of horses

    Studying perceptual bias in favor of the from-above Necker cube perspective in a goal-directed behavior

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    When viewing a completely ambiguous image, different interpretations can switch involuntarily due to internal top-down processing. In the case of the Necker cube, an entirely ambiguous stimulus, observers often display a bias in perceptual switching between two interpretations based on their perspectives: one with a from-above perspective (FA) and the other with a from-below perspective (FB). Typically, observers exhibit a priori top-down bias in favor of the FA interpretation, which may stem from a statistical tendency in everyday life where we more frequently observe objects from above. However, it remains unclear whether this perceptual bias persists when individuals voluntarily decide on the Necker cube's interpretation in goal-directed behavior, and the impact of ambiguity in this context is not well-understood. In our study, we instructed observers to voluntarily identify the orientation of a Necker cube while manipulating its ambiguity from low (LA) to high (HA). Our investigation aimed to test two hypotheses: (i) whether the perspective (FA or FB) would result in a bias in response time, and (ii) whether this bias would depend on the level of stimulus ambiguity. Additionally, we analyzed electroencephalogram (EEG) signals to identify potential biomarkers that could explain the observed perceptual bias. The behavioral results confirmed a perceptual bias in favor of the from-above perspective, as indicated by shorter response times. However, this bias diminished for stimuli with high ambiguity. For the LA stimuli, the occipital theta-band power consistently exceeded the frontal theta-band power throughout most of the decision-making time. In contrast, for the HA stimuli, the frontal theta-band power started to exceed the occipital theta-band power during the 0.3-s period preceding the decision. We propose that occipital theta-band power reflects evidence accumulation, while frontal theta-band power reflects its evaluation and decision-making processes. For the FB perspective, occipital theta-band power exhibited higher values and dominated over a longer duration, leading to an overall increase in response time. These results suggest that more information and more time are needed to encode stimuli with a FB perspective, as this template is less common for the observers compared to the template for a cube with a FA perspective

    Возможности контрастной магнитно-резонансной ангиографии в диагностике синдрома диабетической стопы, осложненного гнойно-некротическими процессами

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    Purpose: evaluation of pedal vascularisation in diabetic patients with pedal purulent necrotic processes of using contrast MR-angiography (3D DCE-MRA). Material and methods. 31 diabetic foot of 31 patients (14 male, 17 female; mean age 54.65 ± 15.1) underwent 3d DCE-MRA (Gadobutrol 15 ml) at 1.5 T. Imaging analysis included vascular architectonic’s condition, blood-flow’s speed and character of contrast’s accumulation. Results were compared with white blood cells-scan in identification of pyoinflamation. Osteomyelitis was verified according to operations in 100% cases. Results. All patients were divided in 3 groups: neuropathic (n = 12; 38.7%), neuroischemic (n = 14; 45.2%), ischemic (n = 5; 16.1%) forms of diabetic foot. First-pass MRA detected significantly delay in contrast’s arrival in ischemic group. There were no significant differences between the values of neuropathic and neuroischemic forms of diabetic foot. There was absence of any pedal vessels in patients. Contrast MR-angiography revealed the three types of contrast distribution in soft tissues: uniform, local increase and local absence. Osteomyelitis associated with diffuse enhanced contrast accumulation in all cases. Conclusion. So MRI blood vessel imaging is a promising and valuable method for examining peripheral arterial changes in diabetic foot and may be useful for treatment planning in different forms of diabetic foot.Цель исследования: оценка состояния сосудистого русла у пациентов с синдромом диабетической стопы (СДС), осложненным гнойно-некротическими процессами, по данным контрастной магнитно-резонансной ангиографии (МРА). Материал и методы. Контрастная МРА (Гадобутрол 15 мл) выполнена 31 пациенту (14 мужчин, 17 женщин, средний возраст 54,65 ± 15,1 года) с различными формами СДС с подозрением на остеомиелит (ОМ) на аппарате с напряженностью магнитного поля 1,5 1л. Оценивали архитектонику сосудов стоп, магистральный кровоток, особенности микроциркуляции. Для идентификации воспалительного процесса проведена сцинтиграфия с меченными лейкоцитами 99Tc-эксаметазим. Диагноз ОМ был установлен при проведении оперативного вмешательства в 100% случаев. Результаты. Все пациенты были разделены на 3 группы: с нейропатической (n = 12; 38,7%), смешанной (n = 14; 45,2%), ишемической (n = 5; 16,1%) формами СДС. При оценке времени поступления контрастного средства в сосуды стоп значительно отличалось время поступления при ишемической форме СДС. При нейропатической и смешанной формах СДС были получены близкие показатели. Было выявлено отсутствие визуализации отдельных сосудистых ветвей при ишемической и смешанной формах СДС. При оценке микроциркуляции определялось 3 типа накопления контрастного препарата вне сосудистого русла в мягких тканях: равномерное, локальное повышенное, локальное отсутствие накопления. Гнойно-некротические процессы характеризовались повышенным локальным длительным накоплением контрастного средства во всех случаях. Выводы. МРА является перспективным методом для изучения изменений периферических сосудов у больных СДС и планирования лечения осложненного течения всех форм СДС

    Dimebon Does Not Ameliorate Pathological Changes Caused by Expression of Truncated (1–120) Human Alpha-Synuclein in Dopaminergic Neurons of Transgenic Mice

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    Background: Recent clinical studies have demonstrated that dimebon, a drug originally designed and used as a non-selective antihistamine, ameliorates symptoms and delays progress of mild to moderate forms of Alzheimer’s and Huntington’s diseases. Although the mechanism of dimebon action on pathological processes in degenerating brain is elusive, results of studies carried out in cell cultures and animal models suggested that this drug might affect the process of pathological accumulation and aggregation of various proteins involved in the pathogenesis of proteinopathies. However, the effect of this drug on the pathology caused by overexpression and aggregation of alpha-synuclein, including Parkinson’s disease (PD), has not been assessed. Objective: To test if dimebon affected alpha-synuclein-induced pathology using a transgenic animal model. Methods: We studied the effects of chronic dimebon treatment on transgenic mice expressing the C-terminally truncated (1–120) form of human alpha-synuclein in dopaminergic neurons, a mouse model that recapitulates several biochemical, histopathological and behavioral characteristics of the early stage of PD. Results: Dimebon did not improve balance and coordination of aging transgenic animals or increase the level of striatal dopamine, nor did it prevent accumulation of alpha-synuclein in cell bodies of dopaminergic neurons. Conclusion: Our observations suggest that in the studied model of alpha-synucleinopathy dimebon has very limited effect on certain pathological alterations typical of PD and related diseases

    Memory Effect in the Spatial Series Based on Diamond and Graphite Crystals

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    To study the relation between the structure of a compound and its properties is one of the fundamental trends in chemistry and materials science. A classic example is the well-known influence of the structures of diamond and graphite on their physicochemical properties, in particular, hardness. However, some other properties of these allotropic modifications of carbon, e.g., fractal properties, are poorly understood. In this work, the spatial series (interatomic distance histograms) calculated using the crystal structures of diamond and graphite are investigated. Hurst exponents H are estimated using detrended fluctuation analysis and power spectral density. The values of H are found to be 0.27–0.32 and 0.37–0.42 for diamond and graphite, respectively. The calculated data suggest that the spatial series have long memory with a negative correlation between the terms of the series; that is, they are antipersistent
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