Taraxacum kok-saghyz is a promising source of natural rubber. To achieve controlled cultivation, in vitro growth methods are proposed. Stimulating the growth of T. kok-saghyz under in vitro conditions is a critical task that will ensure the economic viability of producing natural rubber from this species. The authors suggest adding a filtrate of the culture liquid from the actinomycete Streptomyces tauricus 19/97 M - after cold sterilization - to the nutrient medium used for in vitro cultivation and for treating rubber seeds. Currently, the use of actinomycete metabolites to stimulate rubber plant growth is unprecedented. The aim of this study was to evaluate the effects of metabolites from the S. tauricus 19/97M strain on various parameters, including germination energy, seed germination, explant growth (measured by the mass of the green parts and leaf surface area), and the mass of isolated roots exhibiting the "hairy roots" phenotype of the T. kok-saghyz plant under in vitro conditions. The study utilized the culture liquid of the S. tauricus 19/97M strain, which contained a mixture of metabolites. To obtain secondary metabolites, liquid-phase cultivation of the strain was carried out using a modified starch-ammonium medium with the following composition: starch - 12.5 g/L, (NH₄)₂SO₄ - 2 g/L, NaCl - 1 g/L, K₂HPO₄ - 1 g/L, MgSO₄ × 7H₂O - 1 g/L, and a pH 7.2 buffer solution (KH₂PO₄/NaOH) - 1000 mL. Cultivation was conducted in 250 mL flasks containing 100 mL of nutrient medium for 6 days on a thermostated orbital shaker (IKA KS 4000, Germany) at 160 rpm and 27°C. Sterilization was carried out by ultrafiltration using a membrane filter with a pore diameter of 0.22 µm (Millipore, Germany). The dry substance content in the filtrate was normalized to 34.3 ± 1.7 mg/mL. Biological activity on seeds was assessed by germinating seeds between layers of filter paper moistened with sterile water (control) or with the addition of 0.5, 1, 2, or 10% filtrate in experimental samples. Roots exhibiting the "hairy roots" phenotype were grown on a liquid, hormone-free half-strength Murashige-Skoog (1/2 MS) medium, while explants were cultured on MS agar nutrient medium supplemented with vitamins according to Butenko. In these media, the S. tauricus filtrate was added at concentrations of 0.5, 1, 2, and 5% relative to the volume of the nutrient medium. Data on the effects of metabolites on germination energy and overall germination are presented in the histograms shown in Figures 3A and 3B, respectively. The results indicate a significant increase in both germination energy and seed germination only at culture liquid filtrate concentrations exceeding 1%, with the greatest enhancement observed at a 10% concentration. Specifically, the percentage of germinated seeds in the control group was 16% of the total T. kok-saghyz seeds, whereas treatment with a 10% filtrate solution increased seed germination by 1.46 times, reaching 26.5%. Evaluation of overall germination further confirmed the positive effect of the more concentrated solution on growth parameters. In the control, 41.5% of seeds germinated, while in the experiment using the 10% filtrate solution, germination increased to 68%, representing a 1.6-fold increase compared to the control. When studying the influence of metabolites on the growth parameters of T. kok-saghyz plant explants, it was observed that a 5% filtrate from the culture liquid of S. tauricus reduced the leaf area compared to the control, indicating an inhibitory effect. The total leaf area measured 35.3 ± 1.69 cm², whereas the control measured 44.05 ± 2.10 cm². The maximum leaf area was achieved with the addition of 1% filtrate, reaching 66.9 ± 1.69 cm², which is 1.5 times (51%) greater than the control value. It was also noted that plants with larger leaf areas had fewer leaves on the stem. All differences in leaf area were statistically significant both among the experimental groups and compared to the control. It should be noted that the total mass of the green part of the plant in the experiment did not exhibit as pronounced a peak increase as observed in studies on root biomass accumulation and total leaf area (Fig. 6). A significant increase in mass was observed at filtrate concentrations of 0.5, 1, and 2%, amounting to a 36% increase relative to the control, with no statistically significant differences among these concentrations. However, when filtrate containing metabolites was added at a concentration of 5% to the nutrient medium, inhibition of plant mass accumulation was observed. Similar to the findings on total leaf area, the corresponding plant mass values at this concentration were lower than those of the control. The assessment of root biomass increase using the weight method demonstrated the overall stimulatory effect of metabolites from the strain S. tauricus 19/97M on the growth of "hairy roots". The most pronounced positive effect was observed with the addition of 1% filtrate; the biomass of Taraxacum kok-saghyz roots increased from the initial root mass to 12.94 ± 1.20 g, representing a 60% increase compared to the control. All results showed significant differences both among themselves and in comparison to the control roots grown on standard MS medium. The article contains 8 Figures and 24 References. The Authors declare no conflict of interest.
Forty subjects of both sexes, aged 15 to 45 years and free of acute or chronic diseases during the study period, participated in this investigation to examine the relationships between rhythmic activity indices and the electrical properties of the human myocardium in response to functional tests (FT) targeting parasympathetic and sympathetic activity. Although the study of parasympathetic and sympathetic influences on cardiac function is one of the most promising areas of modern physiology, the extensive literature in this field typically focuses primarily on analyzing heart rate (HR) responses and RR intervals in relation to heart rate variability. The ECG was recorded using the VNR-Rhythm device (Neurosoft, Russia) in the standard lead II position while the subjects were standing. Recordings were taken before (control 1 and 2, prior to each test) and after the functional test (FT), which involved the use of KSP and PM. In each case, 50 cardiac cycles were recorded, but only the first 10 cycles were analyzed. The durations of the PP intervals and TP segments were measured in millimeters and then converted to seconds. The heart rates of 40 participants in the study ranged from 57 to 140 beats per minute. Among them, one person had a heart rate below 60 beats per minute; eight had rates between 60 and 69; seven between 70 and 79; six between 80 and 89; and eighteen had rates of 90 or above. In response to the CSP stimulus, the heart rate decreased by an average of 19%, while it increased by 34% under the influence of the PM (Table 1). The duration of the PP interval increased by 27% in response to the KSP and decreased by 24% following PM stimulation (Table 2). A strong correlation was observed between the PP interval at baseline and its changes in response to both KSP and PM (Fig. 1B). At low heart rates (HR), the pulse pressure (PP) interval is typically prolonged and gradually decreases by a factor of 2.5 as the HR increases. In response to the KSP, as the PP duration shortens, the deviation from the control condition increases. Conversely, in response to the PM, there is no consistent dependence on either low or high PP levels. The results of this study indicate that the duration of the TP segment undergoes the most significant changes in response to both KSP and PM. On average, the TP segment duration increases by 83% compared to the control in response to KSP and decreases by 54% in response to PM. The correlation between changes in the TP segment and changes in the control is moderate but above average (Fig. 1B). The TP segment duration exhibits a stronger dependence on the effects of KSP at both high and low HR and PP values. Notably, among the forty participants, ten exhibited an exceptionally high response to CSP - up to a 367% increase - which significantly exceeds the group average. Of these ten individuals, nine had a control heart rate of 90 bpm or higher (Table 2). These findings suggest that parasympathetic exercise therapy induces an action potential (AP) characterized by a slower rhythm and prolonged ECG element durations, whereas sympathetic exercise therapy produces an AP with a faster rhythm and shortened ECG element durations. Thus, it has been demonstrated that in response to parasympathetic and sympathetic functional tests, changes in the rhythmic activity and electrical properties of the human myocardium occur almost immediately. Individuals with bradycardia exhibit a more pronounced reaction to sympathetic stimuli, whereas those with tachycardia respond more strongly to parasympathetic stimuli. An opposite type of reaction is observed in each case. This phenomenon is undoubtedly of clinical interest. The article contains 1 Figure, 2 Tables, and 29 References. The Authors declare no conflict of interest.
Wind power is a rapidly developing sector of energy production that utilizes a renewable resource - wind. In recent years, concerns have arisen regarding the negative environmental impacts of energy production, particularly on bird populations. Numerous studies from the USA and Europe document such effects on birds. However, in Russia, research on this issue remains limited. The objective of this study is to examine the current status of the fauna and bird populations within the Kola Wind Farm area and to assess the wind farm's impact on them. The Kola Wind Farm is the world's largest wind farm located beyond the Arctic Circle. It is situated in the northern part of the Kola Peninsula (68.84270° N, 34.83970° E), approximately 80 km east of Murmansk (Fig. 1). The facility comprises 57 G132-3.55 MW turbines, each with an installed capacity of 3.55 MW, resulting in a total capacity of 201 MW. The wind farm covers an area of 257 hectares, with approximately 60 km of grader roads. In December 2022, the first phase of the wind power plant, with a capacity of 170 MW (84% of the design capacity), was commissioned for commercial operation. By March 2023, the wind farm had reached 100% of its installed capacity. Most of the wind farm territory lies within the tundra zone, where shrub-lichen communities predominate. A small section of forest-tundra, characterized by birch crooked forests, is located in the western part of the site. Field studies were conducted on August 14-17 and September 24-27, 2023, as well as June 3-9 and July 9-14, 2024. These studies covered the post-nesting migration and autumn bird migration seasons (August and September 2023), as well as the spring passage, arrival, and the beginning and peak of nesting (June and July 2024). The total duration of the studies was 20 days, encompassing more than 150 hours of observation. Birds were detected and identified visually using binoculars, as well as by their calls, nests, remains, and signs of activity. Nesting density was estimated by counting nesting sites, followed by recalculating the data per square kilometer. A total of 33 randomly configured plots, covering a combined area of 11.09 km² (ranging from 0.07 to 1.83 km² each), were evenly distributed throughout the wind farm territory. Surveys were conducted during the onset (June) and peak (July) of the nesting period. Species accounting for 10% or more of the total population density were classified as dominant, while those with a density of at least 1 individual per km² were considered background species. Species representing 6-9% of the total population density were classified as subdominant. During ornithological studies conducted from 2023 to 2024, 55 bird species representing 9 orders and 20 families were recorded within the territory of the Kola Wind Farm. Among these, 38 species were confirmed or presumed to be nesting, 10 species were observed during migration, and 7 species visited the wind farm during the nesting period from adjacent areas (Table 1). The total bird population density in the wind farm area during the 2024 nesting season was 463 individuals per km² (Table 2). The most abundant species were Calcarius lapponicus (20% of the total population density), Anthus pratensis (15%), and Tringa glareola (10%). Secondary species included Pluvialis apricaria (8%), Philomachus pugnax (7%), and both Lagopus lagopus and Calidris alpina (6% each). The maximum bird species diversity (48 species) in the wind farm area was observed in June. In July, the number of species decreased to 35. In August and September, 28 and 16 species were recorded, respectively, which is due to the migration of some migratory species to wintering grounds. The overall population density also consistently decreased from 463 and 178 individuals/km² during the early (June) and peak (July) nesting periods, respectively, to values not exceeding 100 individuals/km² in August (the period of post-nesting migrations) and no more than 20 individuals/km² in September (autumn migration). Six species found in the area - Branta leucopsis, Cygnus cygnus, Circus macrourus, Falco rusticolus, Grus grus, and Numenius arquata - are listed in the Red Data Books of Russia and Murmansk Oblast. Circus macrourus was recorded on the territory of the wind farm more than ten years after its only previous sighting on the Kola Peninsula and significantly further north. This may indirectly suggest episodic nesting of the species in the tundra of the Kola Peninsula, including within the Kola Wind Farm and its surrounding areas. The death of one bird (Stercorarius longicaudus), likely caused by a collision with an operational wind turbine, was recorded. Bird fatalities resulting from the wind turbines at the Kola Wind Farm appear to be infrequent. The local bird population is relatively sparse, with migration occurring over a broad front and at a relatively low intensity. No facilities that typically attract large concentrations of birds - such as solid waste dumps, livestock farms, or slaughterhouses - were found within a 15-20 km radius of the wind farm. Bird mortality resulting from the impact of the Kola Wind Farm may be significantly higher in years of high rodent abundance. For example, the number of vole-eating birds in 2024 was low due to the low abundance of lemmings, which was rated as 1 on a 5-point scale. The negative impact of the wind farm on fauna and bird populations is also evident in the transformation of natural ecosystems caused by the construction and operation of wind turbines, infrastructure facilities, and the road network. Additionally, the presence of substantial construction and technical waste pollutes the natural habitats of birds. Other contributing factors include poaching and the intrusion of synanthropic species - such as Corvus cornix (hooded crow), Corvus corax (common raven), and stray dogs - which actively destroy the nests of many avian species. The article contains 6 Figures, 2 Tables, and 33 References. The Authors declare no conflict of interest.
The importance of rapid adaptation in sports is determined by the athlete's body's ability to adjust quickly to physical exertion. Engaging in physical activity alters the concentration of biologically active substances that influence muscle metabolism; this change is one of the factors that contribute to fatigue, ultimately leading to a decline in motor performance. One indicator of the biochemical changes induced by physical activity is serotonin (5-HT). Numerous studies have demonstrated that the concentration of 5-HT in the blood of athletes increases with the intensity of motor activity. Therefore, the rise in serotonin levels during physical exercise represents a compensatory adaptive response of the body. Thus, the aim of this study is to determine the role of serotonin in the mechanisms underlying the rapid adaptation of the muscular system in football players subjected to extreme physical load. The study group consisted of 16- to 17-year-old football players, while the control group included 16- to 17-year-old young men who were not involved in sports. Before and immediately after physical exercise to failure, the subjects' serotonin concentrations in blood plasma and platelets, as well as 5-hydroxyindoleacetic acid levels in blood plasma, were measured using high-performance liquid chromatography with electrochemical detection (HPLC-ED). Additionally, bioelectrical potentials of the rectus femoris muscle were recorded before and immediately after maximal exercise using interference surface electromyography (EMG) on a 4-channel electroneuromyograph Synapsis (Neurosoft, Russia). A specific physiological response in young athletes subjected to load until failure was demonstrated by a significantly higher serotonin concentration per milligram of platelet protein compared to the control group. In athletes, serotonin levels increased from 130.1 (65.3; 195.7) pmol/mg before the load to 170 (100.9; 266.7) pmol/mg after the load (n = 22, p < 0.05). In contrast, the control group showed no significant change, with levels of 90.3 (65.7; 142.2) pmol/mg before and 88.6 (65; 124.4) pmol/mg after the load (n = 17) (Fig. 1c). This suggests that football training enhances serotonin uptake into platelets, likely due to increased activity and expression of the serotonin transporter (SERT) in the platelet membrane, serving as an adaptive mechanism to high physical demands. Both the football players and the control group exhibited a statistically significant increase in plasma serotonin levels after exercise (athletes: before exercise 5.6 (4.1; 8.2) pmol/mL, after exercise 8.2 (5.6; 10.9) pmol/mL, n = 22, p < 0.05; controls: before exercise 4.1 (2.7; 9.4) pmol/mL, after exercise 12 (5.4; 25.1) pmol/mL, n = 17, p < 0.05) (Table 1). In young men not engaged in sports, this indicator increased by 2.9 times, reflecting an inadequate physiological response to physical exertion. Such a pronounced rise in blood 5-HT concentration may promote blood clot formation due to serotonin's ability to activate 5-HT2A receptors on platelet membranes, thereby triggering platelet activation. The 5-HT/5-HIAA ratio in both athletes and controls also increased significantly after the maximal exercise test, indicating enhanced serotonergic system activity (athletes: before exercise 0.28 ± 0.15, after exercise 0.36 ± 0.19, n = 22, p < 0.05; controls: before exercise 0.24 ± 0.22, after exercise 0.65 ± 0.5, n = 17, p < 0.05) (Table 1). The increase in the recruitment of new motor units involved in the task is indicated by the rise in maximum EMG amplitude (athletes: before the load 2.74 ± 1.12 mV, after the load 3.10 ± 1.55 mV, n = 22, p < 0.05; control: before the load 2.17 ± 0.63 mV, after the load 2.24 ± 0.78 mV, n = 17, p < 0.05) (Table 2). This increase, observed when measuring a fatigued muscle under static tension, is explained by a gradual decline in the contractile capacity of muscle fibers. To compensate, additional motor units are recruited, enabling the muscle to maintain significant force output. The correlation analysis revealed that the serotonin concentration in the blood plasma of football players was significantly correlated with the maximum amplitude of the bioelectrical activity of the rectus femoris muscle (r = 0.668, n = 22, p < 0.05), the average EMG amplitude (r = 0.643, n = 22, p < 0.05), and the area under the EMG curve (r = 0.695, n = 22, p < 0.05), indicating a strong positive relationship. One proposed explanation for the association between serotonin levels and the bioelectrical activity indices of the rectus femoris muscle in football players is that it reflects the mechanism by which 5-HT influences muscle fatigue and reduces physical performance. Motor neurons in the anterior horns of the spinal cord form synaptic contacts with the axons of serotonergic neurons originating from the raphe nuclei. However, 5-HT1A receptors have been identified outside the serotonergic synaptic innervation of these motor neurons. Activation of 5-HT1A receptors by serotonin promotes the efflux of potassium ions through G protein-coupled inwardly rectifying potassium channels (GIRK3), resulting in tonic hyperpolarization. Additionally, this activation inhibits Na⁺ channels involved in action potential generation. This mechanism reduces the excitability of spinal motor neurons in response to elevated serotonin levels, contributing to fatigue and diminishing the capacity to perform prolonged motor tasks. In general, sports activities in football players likely promote an effective system for serotonin uptake into platelets, due to increased activity and expression of SERT in the platelet membrane. This appears to be an adaptive mechanism in response to intense physical exertion. In the control group, a high 5-HT/5-HIAA ratio following extreme muscle exertion indicates low adaptability to physical work, likely due to disrupted activity of the MAO enzyme and the SERT transporter. This disruption may subsequently lead to local thrombus formation. The observed correlations in athletes suggest that high concentrations of serotonin, by acting on motor neurons, induce muscle fatigue, thereby limiting further physical exertion. However, this hypothesis requires additional investigation. The article contains 2 Figures, 2 Tables, and 21 References. The Authors declare no conflict of interest.
Levels of organochlorine pesticides were determined in Comephorus baicalensis (Pallas, 1776), a pelagic sculpin from Lake Baikal. In this study, gas chromatography-mass spectrometry (GC/MS) was used to measure concentrations of organochlorine pesticides (OCPs). The highest concentrations recorded over the entire study period (2000-2023) were for dichlorodiphenyltrichloroethane and its metabolites (1362-4133 ng/g lipid weight), while the concentrations of other OCPs were significantly lower. Decreasing trends were observed for the concentrations of pentachlorobenzene, hexachlorobenzene, trans-chlordane, cis-chlordane, dichlorodiphenyltrichloroethane and its metabolites. No significant trends (p < 0.05) were detected via the Mann-Kendall test for α-hexachlorocyclohexane, cis-heptachlor epoxide, oxychlordane, trans-nonachlor, cis-nonachlor, dieldrin and endrin. The southern basin of the lake continues to receive higher levels of dichlorodiphenyltrichloroethane compounds than the middle and northern basins. The article contains 3 Figures, 2 Tables, and 36 References. The Authors declare no conflict of interest.
