Non-backtracking walks reveal compartments in sparse chromatin interaction networks

Chromatin communities stabilized by protein machinery play essential role in gene regulation and refine global polymeric folding of the chromatin fiber. However, treatment of these communities in the framework of the classical network theory (stochastic block model, SBM) does not take into account intrinsic linear connectivity of the chromatin loci. Here we propose the "polymer" block model, paving the way for community detection in polymer networks. On the basis of this new model we modify the non-backtracking flow operator and suggest the first protocol for annotation of compartmental domains in sparse single cell Hi-C matrices. In particular, we prove that our approach corresponds to the maximum entropy principle. The benchmark analyses demonstrates that the spectrum of the polymer non-backtracking operator resolves the true compartmental structure up to the theoretical detectability threshold, while all commonly used operators fail above it. We test various operators on real data and conclude that the sizes of the non-backtracking single cell domains are most close to the sizes of compartments from the population data. Moreover, the found domains clearly segregate in the gene density and correlate with the population compartmental mask, corroborating biological significance of our annotation of the chromatin compartmental domains in single cells Hi-C matrices

Sewage treatment

The basic function of the wastewater treatment plant is to speed up the natural processes by which water purifies itself. In earlier years, the natural treatment process in streams and lakes was adequate to perform basic wastewater treatment. As our population and industry grew, increased levels of treatment became necessary before discharging domestic wastewater

Secondary caries prevention by considering the features of enamel prisms location during filling of carious cavity

Enamel is the hardest substance in the human body and contains the highest percentage of minerals (96%), with water and organic material composing the rest. The objective: to improve the quality of carious dental cavities filling in patients by determining the regularities of enamel prisms direction and quality of “enamel-filling”connection in topographically different parts of permanent human canines crown. Materials and methods. 40 permamnnet canines with intact enamel, removed because of trauma or orthodontic indications; 89 caries patients. Results. Angulation and direction of enamel prisms in different parts, surfaces and layers of a human permanent canines has been revealed. Conclusions. Features of different parts of enamel prisms inclination in toporgathically different parts of a human permanent canines has been shown. It has been revealed that the efficiency of a filling and enamel coalescence depends on the prevailing direction of enamel prisms in different parts of canine crown. Taking into account the peculiarities of enamel prisms location in the tooth crown at carious cavity preparation, increases the effectiveness of secondary caries prevention

Association between IL-1β, IL-8, IL-10 and VEGF polymorphisms and risk of odontogenic maxillofacial infections

Background. Nowadays it is being reported an increased number of cases of generalization of odontogenic infections which are caused by dental caries, periodontal diseases and other oral diseases. The beginning and progression of diseases depend on individual genetic profile of patient, but data about the role of genetic factors in purulent-inflammatory diseases of maxillofacial area pathogenesis are limited now. The aim of this study was to assess the possible association between IL-1β, IL-8, IL-10 and VEGF polymorphisms and risk of odontogenic maxillofacial infections. Materials and methods 80 patients with odontogenic maxillofacial infection (with and without diabetes mellitus) and 20 donors were examined. All patients’ with odontogenic maxillofacial infection groups were operated and received antibiotic and detoxification therapy. Polymorphism in IL-1B +3954C/T (rs1143634), IL-8 -251T/A (rs4073), IL-10 -1082G/A (rs1800896) and VEGF -634 G/C (rs 2010963) were assessed by polymerase chain reaction. Odds ratio (OR) with 95% confidence interval (CI), Chi-square test were used for statistical analyses. Results. No association observed between VEGF -634 G/C polymorphism and risk of odontogenic maxillofacial infections in patient without diabetes mellitus using all the genetic models. In patients with diabetes mellitus observed association between VEGF -634 G/C polymorphism and odontogenic maxillofacial infections in the codominant (OR=0,429, 95%СІ 0,185-0,994, р=0,046), heterozygous (OR=0,167, 95%СІ 0,048-0,574, р=0,004)and recessive (OR=0,194, 95%СІ 0,061-0,619, р=0,005) models. Polimorphism IL-1B +3954C/T increased the risk of odontogenic maxillofacial infections in patient without diabetes mellitus in the codominant (OR=0,059, 95%СІ 0,023-0,151,

Chemical composition of the enamel of permanent canine teeth

Досліджено вміст кальцію, фосфору та фтору в поверхневих, серединних і глибоких шарах емалі в нижній, середній, верхній частинах коронки постійних іклів людини на бокових, оральній та вестибулярній поверхнях. Топографічно різні ділянки коронки постійних іклів людини мають однаковий вміст кальцію та фосфору. У поверхневих шарах емалі постійних іклів міститься більше фтору, ніж у серединних і глибоких.The aim of the current research is to measure the level of Ca, P and F in the different zones of enamel of the permanent human canine teeth. 40 permanent human canine teeth with sound enamel were used for the research. The level of Ca, P and F was measured by the method of the comparative dispersion of double refraction. The different regions of the crown of human permanent canine teeth exhibited no significant differences in Calcium and Phosphorus level in the crystallites. The content of Fluoride in the crystallites is higher in the outer enamel layers of the permanent canine teeth in comparison to the middle and inner ones

Особенности химического состава эмали постоянных премоляров человека

Досліджено вміст кальцію, фосфору та фтору в поверхневих, серединних та глибоких шарах емалі в нижній, середній, верхній частинах коронки постійних премолярів людини на бокових, оральній та вестибулярній сторонах. Топографічно різні ділянки коронки постійних премолярів людини мають однаковий вміст кальцію та фосфору. В поверхневих шарах емалі постійних премолярів міститься більше фтору, ніж в серединних та глибоких.The aim of the current research is to measure the content of Ca, P and F in the different zones of enamel of the permanent human premolar teeth Materials and methods. 40 permanent human premolar teeth with sound enamel were used for the research. The content of Ca, P and F was measured by the method of the comparative dispersion of double refraction. Results. There were no statistically significant differences estimated between the values of Calcium content in the crystallites in the different regions of human permanent premolar teeth enamel. There was no difference in the content of Calcium in the enamel crystallites at the lateral, lingual and vestibular surfaces of the permanent premolar teeth, as well as in the upper, middle and lower third of their crown. Moreover, the Calcium content did not change from the dentin-enamel junction towards the outer enamel surface. The same results were obtained while comparing the values of Phosphorus content in enamel crystallites in the different regions of permanent premolar teeth enamel. The average Calcium oxide mass fraction in permanent premolar teeth enamel comprised 54,43 %, the average Phosphorus pentoxide mass fraction – 38,44 %. The content of Fluoride ions is 2,9-3,5 times higher in the outer enamel layers of the permanent premolar teeth in comparison to the middle and inner ones. Conclusion. The different regions of the crown of human permanent premolar teeth exhibited no significant differences in Calcium and Phosphorus contents in the crystallites. The content of Fluoride in the crystallites is higher in the outer enamel layers of the permanent premolar teeth in comparison to the middle and inner ones.Исследовано содержание кальция, фосфора и фтора в поверхностных, срединных и глубоких слоях эмали в нижней, средней, верхней частях коронки постоянных премоляров человека на боковых, оральной и вестибулярной сторонах. В топографически различных участках коронки постоянных премоляров человека содержится одинаковое количество кальция и фосфора. В поверхностных слоя

Physical Principles of Retroviral Integration in the Human Genome

Some retroviruses, including HIV, insert their DNA in a non-random manner in the host genome through a poorly understood selection mechanism. Here the authors develop a biophysical model of retroviral integration, identifying previously unnoticed universal principles that regulate this phenomenon

Combined acousto-electromagnetic antennas for radioacoustic sounding of the atmosphere

History of the development of combined acousto-electromagnetic antennas for the atmosphere radioacoustic sounding equipment is briefly considered. Advantages and shortages of combined reflector antennas and combined PAAs are pointed out. The modulation effect of sounding electromagnetic radiation at the sound frequency, which is inherent in the combined antennas, is analyzed. Particular attention is given to the statistical aspects of acoustic PAA operation - to the influence of randomness in the sources distribution in antennas on their radiation patterns

Non-backtracking walks reveal compartments in sparse chromatin interaction networks

Abstract Chromatin communities stabilized by protein machinery play essential role in gene regulation and refine global polymeric folding of the chromatin fiber. However, treatment of these communities in the framework of the classical network theory (stochastic block model, SBM) does not take into account intrinsic linear connectivity of the chromatin loci. Here we propose the polymer block model, paving the way for community detection in polymer networks. On the basis of this new model we modify the non-backtracking flow operator and suggest the first protocol for annotation of compartmental domains in sparse single cell Hi-C matrices. In particular, we prove that our approach corresponds to the maximum entropy principle. The benchmark analyses demonstrates that the spectrum of the polymer non-backtracking operator resolves the true compartmental structure up to the theoretical detectability threshold, while all commonly used operators fail above it. We test various operators on real data and conclude that the sizes of the non-backtracking single cell domains are most close to the sizes of compartments from the population data. Moreover, the found domains clearly segregate in the gene density and correlate with the population compartmental mask, corroborating biological significance of our annotation of the chromatin compartmental domains in single cells Hi-C matrices