Birch Research Articles

Betulin inhibits the production of inflammatory cytokines in human gingival fibroblasts and ligature-induced periodontitis.

Chronic inflammation of the tissues surrounding and supporting the teeth is known as periodontal disease. Human gingival fibroblasts (HGFs) are among the greatest prevalent cells in gingival tissue and play a crucial role in oral infections. Data from the GSE dataset revealed that the inflammatory cytokines IL-1β, IL-6, and IL-8 were up-regulated in periodontitis patients compared to healthy individuals. Betulin, a lupane-type pentacyclic triterpene alcohol extracted from the birch trees, inhibits lipopolysaccharide (LPS; component of gram-negative bacteria)-induced synthesis of IL-1β, IL-6, and IL-8 in HGFs. We also demonstrated that the MAPK and AP-1 signaling cascades mediate betulin's inhibition of inflammatory cytokine production in HGFs. Importantly, betulin reduces the expression of inflammatory cytokines and prevents the progression of ligature-induced periodontitis in vivo. This study provides evidence that betulin is a promising candidate for the management of periodontal disease.

Host Plant Odour and Sex Pheromone are Integral to Mate Finding in Codling Moth

The great diversity of specialist plant-feeding insects suggests that host plant shifts may initiate speciation, even without geographic barriers. Pheromones and kairomones mediate sexual communication and host choice, and the response to these behaviour-modifying chemicals is under sexual and natural selection, respectively. The concept that the interaction of mate signals and habitat cues facilitates reproductive isolation and ecological speciation is well established, while the traits and the underlying sensory mechanisms remain unknown. The larva of codling moth feeds in apple and other rosaceous fruits. We show for the first time that the response of male moths to female sex pheromone codlemone relies upon presence of pear ester, a kairomone emitted by host fruit. In the non-host tree birch, attraction to pheromone alone is very strongly reduced, but is fully rescued by blending pheromone with kairomone. This affords a mechanism how host plant shifts shape new mate-finding signals that can give rise to assortative mating and reproductive isolation.

Treatment effects of nitrogen and phosphorus addition on foliar traits in six northern hardwood tree species.

Foliar traits can reflect fitness responses to environmental changes, such as changes in nutrient availability. Species may respond differently to these changes due to differences in traits and their plasticity. Traits and community composition together can influence forest nutrient cycling. We compared five traits-foliar N, foliar P, specific leaf area (SLA), leaf dry matter content (LDMC), and leaf carbon isotope ratio (δ13C)-in six northern hardwood tree species (Acer rubrum, Acer saccharum, Betula alleghaniensis, Betula papyrifera, Fagus grandifolia, and Prunus pensylvanica) in a nitrogen (N) and phosphorus (P) fertilization study across 10 mid- and late-successional forest stands in New Hampshire, USA. We also analyzed the response of tree growth to N and P addition. Nutrient addition shifted trait values towards the "acquisitive" side of the spectrum for all traits except δ13C, reflecting a tradeoff between water-use efficiency and nutrient-use efficiency. Treatment responses in relative basal area increment revealed that the Betula species were N-limited, but traits of all species responded to either or both N and P addition in ways that suggest N and P co-limitation. Two species displayed lower foliar P under N addition, and three species displayed lower foliar N under P addition, which also suggests co-limitation. These indications of co-limitation were reflected at the community level. Specific leaf area, LDMC, and δ13C differed with stand age within several species. Examining trait responses of tree species and communities to nutrient availability increases our understanding of biological mechanisms underlying the complex effects of nutrient availability on forests.

Environment of European Last Mammoths: Reconstructing the Landcover of the Eastern Baltic Area at the Pleistocene/Holocene Transition

The Eastern Baltic area stands out as a unique location due to the finds of Europe’s youngest dated mammoth remains (12.6–11.2 ka cal BP). Our study explores the drastic climate and landcover changes during the extinction of these gigantic herbivores at the Pleistocene/Holocene boundary. We used macrofossil analysis to determine the major contemporary terrestrial plant genera present in the area and used corresponding pollen taxa for REVEALS model-based landcover reconstructions. Our results indicate that these last mammoths utilised the open landcover of the Eastern Baltic, which developed as the continental ice sheet retreated during the termination of the last glaciation. Due to climate warming during the initial stages of the Holocene interglacial, the Eastern Baltic became speedily populated by birch and pine forests. The abrupt disappearance of typical forb-dominated tundra indicators, such as Dryas octopetala, and the fast increase in tree birch marked a shift from an open, tundra-like landscape to a forested one, making the environment inhospitable for mammoths even in northernmost Estonia by the beginning of the Holocene. A comparison between the isotopic values of nitrogen (δ15N) and carbon (δ13C) obtained from mammoths’ molars from 14.3 and 11.3 to 43.5 and 39.1 ka cal BP showed that mammoths experienced a decline in the nutritional value of their diet, resulting in their demise in the Eastern Baltic.

Urban Greening and Pollen Allergy: Balancing Health and Environmental Sustainability.

Urban living requires a careful balance between human health and environmental sustainability when selecting urban vegetation. Public gardens and green roofs offer significant environmental benefits, including air filtration, exposure to health-associated microbiota, and mitigation of the urban heat island effect. However, prioritizing allergy-friendly species is crucial to prevent the exacerbation of pollen allergies. This review highlights three primary criteria for selecting vegetation that supports these ecosystem services while minimizing allergy risks. Firstly, reducing the use of many wind-pollinated plants, such as birch trees and grasses, is crucial due to their high pollen production and cross-reactivity with other species, which can exacerbate allergies. In contrast, insect-pollinated plants are generally safer for allergy sufferers. Secondly, cultivating multispecies plant communities with minimal maintenance supports habitats for microbiota and invertebrates, further providing ecosystem services. Lastly, balancing plant gender ratios in urban spaces can help control pollen levels. Together these criteria provide a framework for urban planners to create green spaces that are both environmentally beneficial and allergy friendly. Although this review focuses on European data, the principles discussed have global relevance, reinforcing the need to integrate environmental sustainability with public health considerations in urban planning. Future studies should also investigate the health impacts of plant volatile emissions, explore heat-resistant plant varieties, and assess the ecological risks of invasive species to support sustainable, allergy-friendly urban environments.

Foliage development and resource allocation determine the growth responses of silver birch (Betula pendula) to elevated environmental humidity.

Scenarios for future climate predict an increase in precipitation amounts and frequency of rain events, resulting in higher air humidity and soil moisture at high latitudes, including in northern Europe. We analysed the effects of artificially elevated environmental humidity (air relative humidity and soil moisture) on leaf gas exchange, water relations, growth and phenology of silver birch (Betula pendula) trees growing at the Free Air Humidity Manipulation (FAHM) experimental site situated in the hemiboreal vegetation zone, in eastern Estonia, with no occurring water deficit to the trees. The environmental humidity manipulation did not significantly affect the water relations traits but did affect some leaf gas exchange parameters, growth and phenology of the trees. Elevated air humidity (H) did not influence photosynthetic capacity and stomatal conductance, while the trees exhibited higher stomatal sensitivity to leaf-to-air vapour pressure difference compared to the trees at ambient conditions (C) or at an elevated soil moisture (I). H trees demonstrated reduced height growth and foliage biomass, increased allocation to stem radial growth, and prolonged leaf retention in autumn compared to the C trees. Increased air humidity supports longer leaf retention and growth period, but this does not translate into increased growth parameters at the tree level. The changes in tree growth in response to increasing atmospheric humidity could plausibly be explained by (1) retardation of foliage development and (2) changes in resource allocation, causing a shift in the ratio of photosynthetic to non-photosynthetic tissues in favour of the latter. Under high atmospheric evaporative demand, higher stomatal sensitivity in H trees induces faster stomatal closure, which may result in carbon starvation. A future rise in atmospheric humidity at high latitudes may lead to reduced tree growth and forest productivity, in contrast to the predicted future of forests.

Особенности структуры черничных ельников Большого Соловецкого острова

The research has been carried out in the most typical and widespread plantations for Bolshoy Solovetsky Island – in blueberry spruce forests. Forest management materials and data obtained from sample plots have been used. In the latter, as well as in their buffer zones, the diameters and heights of 325 registered trees have been measured and samples have been taken to study the age structure of the stands. The presence of all forest-forming species of the island has been established in the composition of blueberry spruce forests. The average breed composition is reflected by the formula: 6S2B1P1As (6 spruce trees, 2 birch trees, 1 pine tree, and 1 aspen tree). The majority (76 %) of stands is of 0.6–0.7 density, but at the same time, low-density stands also make up a significant proportion – 21 %, and high-density stands are almost absent. According to archival data, there have been no clear-cuttings on the Solovetsky Islands, with the exception of individual cuttings in the 1920s and 1930s when the Solovetsky Special Purpose Camp existed there. All this, it would seem, has to contribute to the preservation of old trees. However, the average age of spruce stands is 155 years, and the oldest live up to 250 years. This age can be considered the limit for the conditions of the Solovetsky Archipelago. It has been shown that all the stands are of different ages with a different distribution of trees by age classes. There are blueberry spruce forests with a significant gap between tree generations, as well as with a cyclical appearance of the maximum number of trees in certain periods. The following types of age structure have been identified: absolutely uneven-age, stepwise unevenage and cyclically uneven-age. Spruce trees have been found to grow quite well in diameter, but growth in height is inhibited, resulting in the formation of highly tapering trunks. On average, the trees reach their maximum height of about 20 m with a diameter of 30–40 cm. The relative height averages 0.66 m/cm – this is 67 % of the indicator of the mainland spruce forests. It is inversely related to the diameter: the greater it is, the lower is the relative height.

Жирнокислотный состав и активность ацил-липидных десатураз в почках березы повислой в зимне-весенний период в Карелии и Якутии

The dynamics of the fatty acid composition and activity of acyl-lipid desaturases contained in the buds of silver birch Betula pendula Roth have been studied. The places of growth of this tree are located in contrasting natural and climatic conditions: at the same latitude – 62° N, but are separated from each other by more than 5 thousand km in the longitudinal direction – 34° E (the vicinity of Petrozavodsk) and 130° E (the vicinity of Yakutsk). It has been found that, regardless of the place of growth, in the spring-winter period, the total lipids of the buds of silver birch have been characterized by a high content of unsaturated fatty acids. At the same time, significant differences have been revealed in the composition of mono-, di- and trienoic fatty acids, the dynamics of which have largely depended on both the phase of winter-spring plant development and the degree of continentality of the climate. It has been shown that in Karelia, during the exogenous dormancy period (January–March), an increased content of dienoic fatty acids is observed in the lipids of the buds of silver birch, and by the beginning of their breaking (April–May) – trienoic fatty acids, whereas in Yakutia in the winter-spring period monoenoic and dienoic fatty acids steadily prevail. At the same time, a high activity of ω6- and ω3-desaturases (responsible for the synthesis of linoleic С18:2 and С18:3 fatty acids) has been detected in the lipids of the buds of silver birch growing in Karelia, and ω9-desaturase (catalyzing the synthesis of oleic С18:1 fatty acid) in Yakutia. It has been suggested that in permafrost conditions there is a relationship between the expression of genes controlling the formation of ω9-acyl-lipid desaturase and the resistance of the tissues of primordial organs during their intra-bud development to negative temperatures not only of the air, but also of the root-inhabited soil layer. The authors believe that the features identified in the composition of total lipids in the buds of silver birch in Yakutia compared to Karelia can be considered as one of the additional mechanisms that increase the adaptive potential of the species in permafrost conditions and allowing the representatives of the genus Betula L. to expand their area to the northern limit of the distribution of woody vegetation.

Differential Responses of Sap Flow to Environmental Factors Under Contrasting Rainfall Amounts During the Rainy Season in a Boreal Birch Forest

ABSTRACTSap flow dynamics are critical for understanding how vegetation consumes water and adapts to environmental stress. The response of sap flow in boreal birch secondary forests to rainfall variations during the rainy season, however, has been inadequately explored. Our study indicated that photosynthetically active radiation (PAR) and vapour pressure deficit (VPD) are the primary drivers of sap flow density in birch trees across different diameter classes (Fds: small trees, Fdm: medium‐sized trees, Fdl: large trees). Soil water content (SWC) significantly reduces sap flow when it falls below the 0.18 cm3/cm3. Sap flow density increased with PAR and initially with VPD but plateaued at higher VPD levels due to saturation. A hierarchy of sap flow density was observed, with Fdl > Fdm > Fds, each responding differently to PAR, VPD and SWC. With decreasing rainfall across rainy seasons, the influence of PAR on Fds and Fdm weakened, while the influence of VPD strengthened. For Fdl, the impact of VPD peaked and then declined, while the influence of PAR showed an inverse pattern. In the dry season, Fdl was primarily driven by PAR and influenced by VPD and SWC, whereas Fds was mainly controlled by VPD, with minimal effects from PAR and SWC. The response of Fdm to SWC was similar to that of Fdl, but it mirrored the response of Fds to PAR and VPD. These findings suggest that sap flow in boreal birch forests may become increasingly susceptible to SWC stress as global climate change intensifies.

Antidiabetic activity of Inonotus obliquus water extract in alloxan-induced diabetic mice.

The Inonotus obliquus is a medicinal mushroom that grows on mature birch trees and is commonly used in traditional medicine for various ailments. The current study aimed to explore the hypoglycemic, hypolipidemic, and pancreatic protective effects of the water extract of Mongolian natural Inonotus obliquus on alloxan-induced diabetic mice. Alloxan monohydrate (200 mg/kg) was intraperitoneally single injected into C57BL/6 mice to induce diabetes. Alloxan-induced diabetic mice were orally given the water extract of inonotus obliquus (WEIO) at doses of 500 mg/kg and subcutaneously administered with insulatard 0.6 IU for 4weeks. Subsequently, the levels of factors related to blood glucose, insulin and lipids were assessed. WEIO significantly restored body weight, reduced fasting blood glucose levels, improved glucose tolerance ability, and increased insulin levels compared to the control diabetic mice. WEIO also enhanced cholesterol transportation in the liver, correlated with increased HDL-C levels and decreased TC, TG and LDL-C levels. Histologic examinations revealed that WEIO alleviated alloxan-induced pancreatic tissue damage. Natural Mongolian I. Obliquus water extracts have an antihyperglycemic effect and enhance islet cell function in alloxan-induced diabetic mice. It is a good candidate for a hypoglycemic functional food or medicine.

Experimental Infection of Small-Diameter Trees with Chaga (Inonotus obliquus) in a Postagrogenous Birch Forest.

Abstract-In the Plyussky district of the Pskov region, an experiment was carried out to infect birch trees with the Chaga pathogen Inonotus obliquus in an 18-year-old postagrogenic birch forest. After 10 years of the experiment, sterile bodies of Chaga were found on six out of ten trees, swelling of the bark was found in one tree, and one tree died from Phellinus nigricans. Infected trees continued to grow at a rate no different from the rest of the forest. Sterile growths were mainly located above the inoculation site. The study showed that the production of Chaga raw materials can be considered as an additional form of forest management in the Non-Black Earth Region of Russia.

The Medicinal Properties of Anogeissus leiocarpus (African Birch Tree) and the Development of a Drug for Diabetes Mellitus and its Complications: A Review

The Medicinal Properties of Anogeissus leiocarpus (African Birch Tree) and the Development of a Drug for Diabetes Mellitus and its Complications: A Review

Factors and effects of inter-individual variability in silver birch phenology using dense LiDAR time-series

Comprehending and quantifying local variability in plant phenology, alongside its impacts on tree growth, is challenging due to spatially and temporally heterogeneous environmental factors that interact to affect phenological events and periods. Although previous studies have focused on the climatic factors driving phenological events at the stand level, the influences of competition, neighborhood characteristics, species richness, and water availability on plant phenology remain unclear. In the present paper, we used hourly terrestrial LiDAR surveys performed between April 2020 and April 2021 to investigate the influence of local factors (neighborhood and topography) on the phenology of silver birch trees (Betula pendula Roth.). We also examined how phenological events affect growth in tree height and crown area. All response and explanatory variables were estimated using LiDAR time-series data and a field survey campaign. Our findings demonstrate a high within-species variability in plant phenology that is controlled by biotic and abiotic characteristics of the ecosystem. We found that between tree variation in leaf burst, completion of the leaf growth and length of canopy growth period were affected by tree size, neighborhood species richness, level of suppression and competition, which potentially indicate plant responses to light availability. The beginning of senescence, completion of leaf drop, and length of autumn phenology were mostly affected by topographic water index, which reflects water availability and can be linked to nutrient availability and exposure to wind. Furthermore, we demonstrated that an earlier leaf burst, and delayed beginning of senescence were associated with larger absolute growth in canopy area but found no clear relationship between height growth and phenology. Our study highlights the capability of dense, high-quality LiDAR time-series to detect significant phenological variation among individuals of the same species within the same locality, demonstrating the potential of LiDAR time-series as a tool for understanding phenology and its impacts.

Does living close to allergenic street trees affect lung function in German adults?

IntroductionStudies on greenspace and lung function in adults produced divergent results. Some of the adverse findings could be due to long-term exposure to allergenic tree pollen. We investigated whether having more birch trees or more allergenic trees around home is related to worse lung function and whether these exposures confound the association between greenspace and lung function. MethodsThe analytic sample consisted of 874 adults aged 20–44 years at baseline from the German study centers, Erfurt and Hamburg, of the ECRHS cohort study. Spirometric lung function was measured in 1991/92, 2000/01, and 2011/12. We counted trees based on tree registries and classified them into allergenic and non-allergenic. We assessed exposure to greenspace with the normalized difference vegetation index (NDVI), tree cover density, and total number of trees in a 300 m buffer around home. Linear mixed models were used. ResultsThe forced expiratory volume in 1 s (FEV1) and the forced vital capacity (FVC) were decreased in the presence of more birch trees after adjusting for confounders and co-exposures. For every 10 additional birch trees in a 300 m buffer around home, the average change in FEV1 was −27.6 mL (95% confidence interval (CI): [-58.7, 3.5]). For FVC the average change was −28.2 mL (95% CI: [-62.0, 5.6]). No consistent associations were found for allergenic trees, total trees, tree cover density, or NDVI. Unlike other associations, those of birch trees with FEV1 and FVC were not moderated by allergic sensitization to birch pollen, history of asthma symptoms or nasal allergies including hay fever, ozone, NO2, or age. DiscussionLiving close to birch trees had an adverse long-term association with lung function. That tree registries were limited to street trees prevented us from answering the question of a potential confounding of greenspace effects by allergenic neighborhood trees.

Research on Chaga hypoglycemic functional foods

Chaga, also known as Inonotus obliquus (Fr.) Pilát, belongs to the genera Basidiomycotina, Hymenomycetes, Hymenochaetales, Hymenochaetaceae, and Inonotus. Chaga is a brown polypore fungus that mostly grows under the bark of white birch and silver birch trees. It forms sarcoma-like sclerotia when the bark is damaged. It mainly grows in Northern Europe at the 40° to 50° north latitude, Siberia and the Far East in Russia, Hokkaido in Japan, and the Changbai Mountain area of the Heilongjiang Province and Jilin Province in China. Chaga has various pharmacological activities, such as anti-tumor, hypoglycemic, anti-viral, and anti-inflammatory. Inonotus obliquus, an edible fungus with the same origin as medicine and food, has attracted more and more attention. At present, Chaga has become a raw material with great potential for developing functional foods. In this article, Chaga’s blood sugar-lowering function, functional ingredients, and blood sugar-lowering mechanism and the development status of Chaga functional foods are reviewed and Chaga’s future development is analyzed and forecast.

Transcriptome sequencing-based analysis of primary vein development in Betula pendula ‘Dalecarlica’

Keymessage The study revealed the major biological processes occurred at three developmental stages and identified candidate genes involved in primary vein development of birch plants.Vascular tissues usually mirror the surrounding leaf shape and its development plays a fundamental role in plant performance. However, the information of vascular development in birch trees, especially primary vein development, remains unclear. Therefore, we conducted the anatomical observation on primary veins from leaves at different development stages in Betula pendula ‘Dalecarlica’. With the development of primary vein, dynamic changes in mechanical tissue thickness and primary vein diameter were consistent with each other, and the sum of phloem, xylem and cambium thickness was significantly varied. Transcriptome analysis indicated that primary vein development could be divided into three stages, namely Stage I, II and III, which were in aggreement with anatomical observation. Expression of marker genes associated with vascular tissues revealed that pro-vasculature development occurred at Stage I and II, and phloem development occurred at Stage III. GO enrichment analysis of differentially expressed genes (DEGs) showed that shared DEGs at Stage II were mainly engaged in cell division and cell cycle, and shared DEGs at Stage III were mainly engaged in phosphorylation. Decreased cell division and cell cycle as well as activation of lignin biosynthesis might contribute to primary vein development. Combining phenotypic traits, we performed weighted gene co-expression network analysis and identified a cytochrome P450 84A (CYP84A) family gene (BpF5H1). Based on analyses of gene families, expression patterns and yeast-two hybrid assay results, we proposed a potential electron transfer pathway involving BpF5H1 and three cytochrome b5 proteins during primary vein development in B. pendula ‘Dalecarlica’. These results could shed some light on which biological processes occurred during primary vein formation and provide some valuable clues for vascular morphogenesis in woody plants.

Bark Thickness of Forest-forming Species: Modeling and Comparative Analysis

The need to assess the carbon-depositing capacity of a stand, an individual tree and its components is constantly emphasized in the world literature, since mitigation of the effects of climate change has become the highest priority. Since the carbon concentration differs in different tree species and in different components of the tree, including in the stem wood and bark, it is necessary to develop species-specific mathematical models for estimating the proportion of bark in trunks to improve the accuracy of knowledge about the carbon balance of forests. The relationship of bark thickness with both age and diameter of the tree trunk is known, but with respect to its regional variability, the data are contradictory. According to the actual data from 1100 model trees of five forest-forming species, allometric models of a mixed type have been developed. They include as independent variables the age and diameter of the trunk, as well as a binary variable characterising the influence of the growing area itself on the bark thickness of Scots pine, silver birch and Siberian larch, as well as the difference in the thickness of the bark between Siberian spruce and Siberian fir in case of joint growth in mature stands of the taiga zone. At a statistically significant level, it was found that the bark thickness of Scots pine and silver birch trees in the steppe zone is significantly greater compared to the taiga zone, and the bark thickness of Siberian larch trees in the forest-tundra is significantly greater compared to the steppe zone. The bark thickness of Siberian spruce trees is significantly less than that of Siberian fir trees. The ranking of species by bark thickness is included in the paper.

Dammarane-Type 3,4-seco-Triterpenoid from Silver Birch (Betula pendula Roth) Buds Induces Melanoma Cell Death by Promotion of Apoptosis and Autophagy.

Despite unquestionable advances in therapy, melanoma is still characterized by a high mortality rate. For years, high expectations have been raised by compounds of natural origin as a component of pharmacotherapy, particularly by triterpenes found in the bark of birch trees. In this study, 3,4-seco-dammara-4(29),20(21),24(25)-trien-3-oic acid (SDT) was isolated from buds of silver birch and its mechanisms of cell death induction, including apoptosis and autophagy, were determined. Cytotoxicity of SDT was evaluated by the cell viability test and clonogenic assay, whereas induction of apoptosis and autophagy was determined by annexin V staining and Western blot. The results revealed dose- and time-dependent reductions in viability of melanoma cells. Treatment of cells for 48 h led to an increase in the percentage of annexin V-positive cells, activation of caspase-8, caspase-9, and caspase-3, and cleavage of PARP, confirming apoptosis. Simultaneously, it was found that SDT increased the level of autophagy marker LC3-II and initiator of autophagy beclin-1. Pretreatment of cells with caspase-3 inhibitor or autophagy inhibitor significantly reduced the cytotoxicity of SDT and revealed that both apoptosis and autophagy contribute to a decrease in cell viability. These findings suggest that 3,4-seco-dammaranes may become a promising group of natural compounds for searching for anti-melanoma agents.

Regional features of sensitization to various allergens in children with allergic diseases, taking into account the formed exposome.

Background. According to statistical data from the WHO and a number of researchers, up to 40% of the world's population. Assessing the impact of the exposome in the population of the Russian Federation is a crucial issue of national public health care, the solution of which will provide a personalised approach to the treatment and prevention of allergic diseases in the local population. The aim of this study was to evaluate the sensitisation profile in children with allergic diseases from different regions of Russia. Methods. The study included sick children with allergic manifestations from different regions of the Russian Federation. A separate group consisted of children from the Far North regions from 2 to 12 years of age. The concentration of total IgE and allergen-specific immunoglobulins in blood was determined retrospectively on the basis of analyses of results obtained in CDCs performing immunoblotting tests using the Allergy-Q test system. Results. It was found that in more than 60% of cases allergic reactions are represented by combined manifestations. Allergic rhinitis took the second place, up to 65.32% of cases. Atopic dermatitis in the structure of allergic diseases took the third place, which was about 22,06%. The diagnosis of allergic conjunctivitis in our study was established in 15.38% of cases. Less than 5% in the structure of allergies was occupied by urticaria. In the group of household allergens the first place is occupied by cat, then dog and already then house dust. Among respiratory allergens, birch and/or other trees, weeds and mugwort are the leaders. Food sensitisation in children is mainly to milk, egg, fish and seafood. Conclusion. The peculiarities of sensitisation revealed in different regions are easily explained by the formed exposomes. The obtained data can be used to develop measures of prevention, diagnosis and treatment of allergic diseases.

A Novel Meta-Heuristic Algorithm Based on Birch Succession in the Optimization of an Electric Drive with a Flexible Shaft

The paper presents the application of a new bio-inspired metaheuristic optimization algorithm. The popularity and usability of different swarm-based metaheuristic algorithms are undeniable. The majority of known algorithms mimic the hunting behavior of animals. However, the current approach does not satisfy the full bio-diversity inspiration among different organisms. Thus, the Birch-inspired Optimization Algorithm (BiOA) is proposed as a powerful and efficient tool based on the pioneering behavior of one of the most common tree species. Birch trees are known for their superiority over other species in overgrowing and spreading across unrestricted terrains. The proposed two-step algorithm reproduces both the seed transport and plant development. A detailed description and the mathematical model of the algorithm are given. The discussion and examination of the influence of the parameters on efficiency are also provided in detail. In order to demonstrate the effectiveness of the proposed algorithm, its application to selecting the parameters of the control structure of a drive system with an elastic connection is shown. A structure with a PI controller and two additional feedbacks on the torque and speed difference between the drive motor and the working machine was selected. A system with rated and variable parameters is considered. The theoretical considerations and the simulation study were verified on a laboratory stand.