19 research outputs found
Ваlance of thyroid hormones in conditions of the growing normobaric hypoxia in persons with different degrees of adaptation to the loads of anaerobic character
Objective: is to study the reaction of the pituitary-thyroid system in conditions of acutely increasing normobaric hypoxia in healthy individuals. Materials and methods: a dynamic study of the reaction of the pituitary-thyroid system under conditions of acutely increasing normobaric hypoxia in 24 healthy individuals with varying degrees of adaptation to physical activities of anaerobic nature was carried out. The study of changes in hormonal background was conducted by radioimmune method. In the training of 12 rowing athletes (average age 22±0.7 years) of the main group, anaerobic loads were widely used. The comparison group consisted of 12 conditionally healthy men (average age 21.5±0.6 years) who were not involved in sports Results: with the development of hypoxic state in individuals who train under anaerobic exercise conditions, there was a significant increase in blood plasma T3 with a decrease in the concentration of T4, and TTG increase during last minutes before the termination of the hypoxic load, followed by an increase in the recovery period of blood T4. In untrained individuals, at the beginning of the hypoxic state, there was an increase in the concentration of T3 with an unreliable decrease in the content of T4. Starting from 5 minutes of the study, the content of plasma T4 increased, with a simultaneous increase in the amount of TTG, and the content of T3 decreased. Conclusion: according to the results of the conducted study, there is a specific reaction on the part of thyroid hormones in response to normobaric hypoxia, aimed at economizing intracellular oxidative processes and the formation of a structural trace of adaptation. Systematic exercises with intensive physical anaerobic workouts increase the adaptive capacity of the thyroid system
Комплексы жесткокрылых из четвертичных отложений р. Кизиха - самые южные позднеплейстоценовые насекомые Западно-Сибирской равнины
Two sites with insect remains were found in an exposure on the bank of Kizikha river, in the Rubtsovskii District of the Altaiskii Krai of Russia, Kizikha-1 with radiocarbon age 13455±150 14C BP (SPb-1347), and Kizikha-2 with the age 26094±400 14C BP (SPb-1418). This period is coincides with Sartan stadial and Kargin interstadial (MIS 2 and MIS 3). This is the southernmost late Pleistocene insect bearing deposit found in West Siberia. The fragments in both sites are represented mainly by Coleoptera. Beetle fauna from the site Kizikha-1 is represented by 34 species from 9 families. The majority of fragments belong to weevils and ground beetles. 28 species from 8 families are found in Kizikha-2 site, the majority of fragments belong to Carabidae. 7 species found in the sites, Dyschiriodes rufimanus, Cymindis cf. rostowtzowi (Carabidae), Cidnopus cf. parallelus, Pristilophus punctatissimus (Elateridae), Hemitrichapion alexsandri (Brentidae), Paophilus albilaterus and Otiorhynchus sushkini (Curculionidae), are recorded in Pleistocene deposits for the first time. Sub-fossil insect assemblages of the two sites coincides with the late Pleistocene “Otiorhynchus-type” sub-fossil insect fauna from southeastern part of West-Siberian Plain (Zinovyev, 2011; Legalov et al., 2016) with characteristics as follows: dominance of steppe species, presence of halophile species, lack of forest species. Most of these species are absent in the contemporary regional fauna. The complex of eastern species and presence of endemics of Altai-Sayan Mountain system is also characteristic to the both studied sites. Specifics of the deposit assemblages in comparison with the other late Pleistocene fauna of West Siberian Plain is in high share of meadow species that could be explained by taphonomic condition of sedimentation or microclimatic conditions caused by close location to Altai mountains. Analysis of sub-fossil insect fragments showed that open landscapes with zonal steppe and sparse meadow vegetation near rivers and in depressions were typical for this area. In comparison to contemporary conditions climate was dry and cold, but Kizikha-2 (end of MIS 3) was formed in more mild climate conditions than Kizikha-1 (end of MIS 2). Results gained from Kizikha-1 and Kizikha-2 sites are complementing data on latitudinal-zonal distribution of beetles found in late Pleistocene deposits in West Siberian Plain
Changes in Biomass and Diversity of Soil Macrofauna along a Climatic Gradient in European Boreal Forests
Latitudinal gradients allow insights into the factors that shape ecosystem structure and delimit ecosystem processes, particularly climate. We asked whether the biomass and diversity of soil macrofauna in boreal forests change systematically along a latitudinal gradient spanning from 60° N to 69° N. Invertebrates (3697 individuals) were extracted from 400 soil samples (20 × 20 cm, 30 cm depth) collected at ten sites in 2015–2016 and then weighed and identified. We discovered 265 species living in soil and on the soil surface; their average density was 0.486 g d·w·m−2. The species-level diversity decreased from low to high latitudes. The biomass of soil macrofauna showed no latitudinal changes in early summer but decreased towards the north in late summer. This variation among study sites was associated with the decrease in mean annual temperature by ca 5 °C and with variation in fine root biomass. The biomass of herbivores and fungivores decreased towards the north, whereas the biomass of detritivores and predators showed no significant latitudinal changes. This variation in latitudinal biomass patterns among the soil macrofauna feeding guilds suggests that these guilds may respond differently to climate change, with poorly understood consequences for ecosystem structure and functions
New Data on the Distribution of Southern Forests for the West Siberian Plain during the Late Pleistocene: A Paleoentomological Approach
Subfossil remains of insects and branchiopod crustaceans (Cladocera and Notostraca) found in three late Pleistocene deposits in the Novosibirsk region in the vicinity of the village of Suzun have been described. The calibrated radiocarbon dates for these deposits were 24,893-25,966 cal BP (Suzun-1), 20,379-20,699 cal BP (Suzun-2), and 27,693-28,126 cal BP (Nizhny Suzun), which correspond to the onset of marine isotope stage 2 (MIS 2). The insect assemblages of these deposits are mainly represented by Coleoptera, which are noteworthy for high taxonomic and ecological diversity. At least 194 beetle species from 21 families have been found altogether. Of them, 74 species were found in the Pleistocene deposits of Western Siberia for the first time. All deposits were similar in species composition of beetles; Carabidae and Curculionidae prevailed everywhere. The ecological composition was dominated by steppe and tundra-steppe species; aquatic and riparian groups were also well represented. The Cladoceran and notostracan taxa revealed in Suzun-1 and Suzun-2 are characteristic of recent steppes rather than the forest zone of Western Siberia. The studied entomocomplexes are congruent with the periglacial Otiorhynchus-type fauna that inhabited the southern part of the West Siberian Plain at the end of the Pleistocene and had no close contemporary analogues. Cold and dry conditions, as well as the prevailing open landscapes of the tundra-steppe type, were the reconstructed conditions for this fauna. At the same time, the Suzun-1 and Suzun-2 entomocomplexes had a distinctive feature, namely a high proportion of forest species associated with both coniferous and deciduous trees. According to these data, at the beginning of MIS 2 in the Upper Ob region, spruce forests with the participation of small-leaved species (birch) were present. They were probably confined to river valleys and were not widely distributed
Insects and molluscs of the Late Pleistocene at the Gornovo site (Southern Ural foreland, Russia): New data on palaeoenvironment reconstructions
The paper presents new data on the subfossil insects and molluscs, as well a new radiocarbon date for the Gornovo site in the Southern Fore-Urals. As a result, the stratigraphic interpretation of the sediments of the lower part of the first above floodplain terrace of the Belaya River is corrected and they are assigned to the Tabulda Horizon (MIS 3) of the Upper Pleistocene in the regional scheme of the Fore-Urals Quaternary. The malacofauna of the locality is represented by 27 species of terrestrial and freshwater molluscs. The composition of molluscs in the deposits of MIS 3 indicates the succession of deposit accumulation in the river valley from the stage of reservoirs that periodically connecting with the river to the stage of the overgrown oxbow lake. Single occurrence of mollusc shells in the loams of MIS 2 is a result of sharp climate change. New insect material includes 136 species of Coleoptera from 17 families, as well as Heteroptera and Hymenoptera representatives. 29 species of beetles (Carabidae, Histeridae, Scarabaeidae, Elateridae, Tenebrionidae, Chrysomelidae, Brentidae and Curculionidae) are recorded for the Pleistocene for the first time. The insect assemblages from Gornovo site are assigned to periglacial and humid boreal faunal types. The entomofauna of the periglacial type has no analogues in the recent fauna; it corresponds to the deposits assigned to the middle of MIS 3. This entomofauna is characteristic to the MIS 2 and MIS 3 insect assemblages from the south of West Siberian Plain. Based on entomological data, the climate of the middle of MIS 3 of the Southern Fore-Urals is reconstructed as dry and cold, extracontinental, with mean July temperature not exceeding +15 °C. Steppe landscapes likely prevailed in open areas and coniferous forests were restricted to river valleys. Beetles from deposits dated to end of MIS 3 are assigned to the fauna of the boreal humid type. These insect assemblages are significantly poorer in diversity than periglacial type assemblages and are represented mainly by near water and forest Coleoptera. Based on these species, meadow and forest landscapes were reconstructed. The reconstructed mean air temperature of July ranged from +16 to +19 °C. This suggests a trend towards more mild conditions in the region connected to the climate warming at the end of MIS 3. It is likely that humidification during this period was regional, determined by the proximity of the site to the Southern Urals Mountains. © 2021 Elsevier Ltd and INQU
Changes in Biomass and Diversity of Soil Macrofauna along a Climatic Gradient in European Boreal Forests
Latitudinal gradients allow insights into the factors that shape ecosystem structure and delimit ecosystem processes, particularly climate. We asked whether the biomass and diversity of soil macrofauna in boreal forests change systematically along a latitudinal gradient spanning from 60° N to 69° N. Invertebrates (3697 individuals) were extracted from 400 soil samples (20 × 20 cm, 30 cm depth) collected at ten sites in 2015–2016 and then weighed and identified. We discovered 265 species living in soil and on the soil surface; their average density was 0.486 g d·w·m−2. The species-level diversity decreased from low to high latitudes. The biomass of soil macrofauna showed no latitudinal changes in early summer but decreased towards the north in late summer. This variation among study sites was associated with the decrease in mean annual temperature by ca 5 °C and with variation in fine root biomass. The biomass of herbivores and fungivores decreased towards the north, whereas the biomass of detritivores and predators showed no significant latitudinal changes. This variation in latitudinal biomass patterns among the soil macrofauna feeding guilds suggests that these guilds may respond differently to climate change, with poorly understood consequences for ecosystem structure and functions.</p
Анализ моделей патрулирования области беспилотными летательными аппаратами для обслуживания мобильных абонентов
The number of areas in which unmanned aerial vehicles (UAVs) are used is increasing and one of such areas is the use of UAVs to expand communication networks in remote areas or in places with a high network load. The use of UAVs for these purposes can ensure uniform coverage of the communication area and provide a higher and more stable data transfer rate. One of these tasks is to patrol the area with aircraft, for example, at public events or to collect various environmental data. The paper considers two models of UAV movement, the effectiveness of which is estimated from the point of view of the probability of user coverage.Количество сфер, в которых используются беспилотные летальные аппараты (БПЛА) постоянно увеличивается, и одной из них является использование БПЛА для расширения сетей связи в удалённых областях или в местах с высокой нагрузкой на сеть. Использование БПЛА в этих целях может обеспечить равномерное покрытия зоны предоставления связи и обеспечить более высокую и стабильную скорость передачи данных. Одной из задач является патрулирование области летательными аппаратами, например, на массовых мероприятиях или для сбора различных данных об окружающей среде или обстановке. В работе рассмотрены две модели перемещения БПЛА, эффективность которых оценена с точки зрения вероятности покрытия пользователей
Can Larvae of Forest Click Beetles (Coleoptera: Elateridae) Feed on Live Plant Roots?
The life histories of many soil-dwelling invertebrates remain poorly studied. The larvae of two click beetle species, Athous subfuscus and Dalopius marginatus, which are most abundant in European boreal forests, are both classified as omnivorous and are included in lists of root-damaging pests. Nevertheless, we are not aware of any direct proof of their ability (or inability) to consume plant roots. In this study, we asked whether these larvae actually feed on the roots of forest plants in the absence of other food sources. Live roots of boreal forest plants, including trees (Betula pubescens, Picea abies and Pinus sylvestris) and grass (Deschampsia flexuosa), were offered to click beetle larvae in a two-month microcosm experiment. The weight of roots placed in vials with the wireworms did not decrease, indicating that the larvae of these click beetle species did not feed on live roots, even in the absence of other food sources. This suggests that the feeding niches of A. subfuscus and D. marginatus larvae are narrower than previously thought and do not include live plant tissues. Therefore, these click beetle species should be excluded from the lists of forest pests damaging tree roots