Экономный алгоритм нахождения средних минимальных расстояний

Let £o,..., £n be strings drawn from some finite alphabet. In this paper we describe an algorithm for finding mean minimum distances between strings io,..., £s for all s ^ n. The complexity of the algorithm is O(nm), where m is the length of strings.Пусть заданы n + 1 строк £0 ... , £n с символами из некоторого конечного алфавита. В работе предлагается алгоритм нахождения величин среднего значения fc-го минимального расстояния между строками £о,... , £s для всех значений

Построение оценки энтропии для специальной метрики и произвольной функции

The paper proposes a generalization of entropy as in [1]. At first, to constract the estimator, we select the metrics on the space of sequances. This metrics is based on a matrix that can be interpreted as an edge coloring of a complete graph with loops. A generalization consists in that instead of using the logarithm in the estimation of the entropy, we apply a similar function which may be arbitrary at the given range. The proposed function is not monotone, so the task of optimizing the average deviation which is a quadratic optimization problem, is solved in the whole space and not on the simplex. The main properties of the estimator, such as asymptotic unbiasedness and power decrease dispersion, are proved in a similar way.В статье предлагается обобщение оценки энтропии, предложенной в работе [1]. Для построения оценки сначала выбирается метрика на пространстве последовательностей. Эта метрика строится по матрице, которую можно интерпретировать как реберную раскраску полного графа с петлями. Обобщение состоит в том, что вместо логарифма в оценке энтропии применяется похожая функция, которая может быть произвольной на заданном интервале. Предлагаемая функция не является монотонной, поэтому задача оптимизации среднего отклонения, которая является задачей квадратичной оптимизации, решается на всем пространстве, а не на симплексе. Основные свойства оценки, такие как, асимптотическая несмещенность и степенное убывание дисперсии, доказываются аналогичным образом

Смещение оценки энтропии для симметричных мер Бернулли и слабой метрики

We consider symmetric Bernoulli measures and new weak metrics and obtain a closed-form expression of the entropy estimator bias.Для симметричной меры Бернулли и новой слабой метрики найдено смещение оценки энтропии

The cyclic stability of rubber-like behaviour in stress-induced martensite aged Ni49Fe18Ga27Co6 (at.%) single crystals

In present work, the cyclic stability of the rubber-like behaviour (RLB) was investigated in Ni49Fe18Ga27Co6 (at. %) single crystals. Crystals were aged in the martensite phase at 423 K for 1 h under a compressive stress of 450 MPa, applied along the [110]B2[100]L10-direction. The RLB was induced by a preliminary chemical stabilization of the oriented L10-martensite during stress-induced martensite aging (SIM-aging) and following the reversible reorientation of martensitic variants under a compressive stress applied along the [001]B2[001]L10-direction. The high cyclic stability of the RLB was obtained in 200 loading/unloading cycles, due to the low reorientation stresses of the L10-martensite variants (no higher than 140 MPa) and the high strength properties of the L10-martensite (~1.6 GPa). The irreversible strain after 200 cycles did not exceed 0.6%. An increase in the number of cycles did not lead to the effect of destabilization of the L10-martensite

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

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)

Democratization in a passive dendritic tree : an analytical investigation

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

Orientation dependence of superelasticity in quenched high-nickel Ti51.8Ni single crystals

The orientation dependence of the functional and mechanical properties of quenched Ti-51.8at.%Ni single crystals, undergoing a strain-glass transition upon cooling/heating was investigated. It was found that a compressive stress above 800 MPa leads to the B2-B190 martensitic transformation (MT), regardless of orientation. In the high-strength [0 0 1]-orientation, superelasticity (SE) was observed at 203–248 K, with a reversible strain of 2.3%. Degradation of SE at deforming stresses r > 1000 MPa was associated with the formation of {1 1 3}B2 twins during the reverse MT. In the low-strength 1 1 1-orientation, the formation of stress-induced B190 -martensite occurred simultaneously with the plastic deformation of the B2-phase (due to the formation of reorientation bands and dislocation slip) and a reversible strain was not observed

Ontogenetic Development of Neural and Muscular Rhythmic Activity and Its Regulation in Mammals during Perinatal Period

This review covers our recent advantages in studying the ontogenetic aspects of physiological mechanisms underlying regulation of rhythmic behavior. We have revealed that excitation patterns that emerged at early stages of phylogenetic development of life forms contribute greatly to the rhythmic activity of living vertebrates and invertebrates. These patterns govern spontaneous excitation, which is easily observed during the early stage of ontogenesis. The intensity and patterns of rhythmic activity are determined by nature and kinetics of certain metabolic reactions. During perinatal and sometimes postnatal periods (as in prematurely born animals), endogenic rhythmicity of developing physiological structures is strongly pronounced due to relatively stable living conditions. This rhythmic behavior is coordinated within an entire organism. Its integration in multiple systems is driven by amplitude and frequency modulation yielding rhythms of various frequency ranges. Indeed, it is the complex and conjoint functioning of physiological systems that maintains homeostasis in developing organisms. We present the results of our authentic research concerning the evolution and ontogeny of regulatory mechanisms of motor, cardiovascular, and respiratory systems. The aspects of intact and disrupted development are considered, involving the changes in dopaminergic, norepinephrinergic, and cholinergic system activation

On parasite fauna of the European beaver

The purpose of the research is identification of the current parasitological situation for Eurasian beavers inhabiting the Central Russia.Materials and methods. The work was carried out on hunting farms and in specially protected areas of the Central Russia. Potentially infective material was collected, recorded and preserved from animals during 2015–2021. The age of the animals was determined by their weight and physiological state of the rodents’ teeth and internal organs, and the sex was determined by their genitals. The animals were examined according to the method of complete and partial helminthological dissection per Skryabin.Results and discussion. A total of 41 animals were examined. Three forms of parasitism on animals were identified in natural habitat, namely, the trematode Stichorchis subtriquetrus, the nematode Travassosius rufus, and the ectoparasite Platypsyllus castoris. The stichorchosis causative agent localized in the animal’s large intestine was diagnosed in 35 rodents (85.4%). The helminth infection was 96% in the Eurasian beaver and 68.7% in the Canadian beaver. The nematode infection in stomach was detected in 31 animals (75.6%). The infection by T. rufus was 88% in the Eurasian beaver, and 56.3% in the Canadian beaver. The infected animals were delivered from the Vladimir, Moscow, Ryazan, Tula and Yaroslavl Regions. The beaver beetle P. castoris was found in 6 animals (14.6%). The infection rate was 8% in the Eurasian beaver, and 25% in the Canadian beaver. Animals with wingless arthropods have been identified in the Moscow and Ryazan Regions

Association Between Genetic Variants on Chromosome 15q25 Locus and Objective Measures of Tobacco Exposure

Background: Two single-nucleotide polymorphisms, rs1051730 and rs16969968, located within the nicotinic acetylcholine receptor gene cluster on chromosome 15q25 locus, are associated with heaviness of smoking, risk for lung cancer, and other smoking-related health outcomes. Previous studies have typically relied on self-reported smoking behavior, which may not fully capture interindividual variation in tobacco exposure. / Methods: We investigated the association of rs1051730 and rs16969968 genotype (referred to as rs1051730–rs16969968, because these are in perfect linkage disequilibrium and interchangeable) with both self-reported daily cigarette consumption and biochemically measured plasma or serum cotinine levels among cigarette smokers. Summary estimates and descriptive statistical data for 12 364 subjects were obtained from six independent studies, and 2932 smokers were included in the analyses. Linear regression was used to calculate the per-allele association of rs1051730–rs16969968 genotype with cigarette consumption and cotinine levels in current smokers for each study. Meta-analysis of per-allele associations was conducted using a random effects method. The likely resulting association between genotype and lung cancer risk was assessed using published data on the association between cotinine levels and lung cancer risk. All statistical tests were two-sided. / Results: Pooled per-allele associations showed that current smokers with one or two copies of the rs1051730–rs16969968 risk allele had increased self-reported cigarette consumption (mean increase in unadjusted number of cigarettes per day per allele = 1.0 cigarette, 95% confidence interval [CI] = 0.57 to 1.43 cigarettes, P = 5.22 × 10−6) and cotinine levels (mean increase in unadjusted cotinine levels per allele = 138.72 nmol/L, 95% CI = 97.91 to 179.53 nmol/L, P = 2.71 × 10−11). The increase in cotinine levels indicated an increased risk of lung cancer with each additional copy of the rs1051730–rs16969968 risk allele (per-allele odds ratio = 1.31, 95% CI = 1.21 to 1.42). / Conclusions: Our data show a stronger association of rs1051730–rs16969968 genotype with objective measures of tobacco exposure compared with self-reported cigarette consumption. The association of these variants with lung cancer risk is likely to be mediated largely, if not wholly, via tobacco exposure