Differential acclimation responses to irradiance and temperature in two co-occurring seaweed species in Arctic fjords

Arctic fjord systems experience large amplitudes of change in temperature and radiation regime due to climate warming and the related decrease in sea ice. The resultant increase in irradiance entering the water column influences photosynthetic activity of benthic and pelagic primary producers. The subtidal brown alga Desmarestia aculeata and the intertidal red alga Palmaria palmata populate the cold-temperate coasts of the North Atlantic, reaching the polar zone. To evaluate their acclimation potential, we collected both species in Kongsfjorden, Svalbard (78.9°N, 11.9°E), during the Arctic summer and exposed specimens to two different PAR levels (50 and 500 μmol photons m−2 s−1) and temperatures (0, 4 and 8 °C) for 21 days. Photosynthetic parameters and biochemical features (pigment concentration and antioxidants) were assessed. In general, high irradiance was the factor that generated a negative effect for D. aculeata and P. palmata in the photosynthetic parameters of the photosynthesis–irradiance curve and Fv/Fm. The pigment concentration in both species tended to decrease with increasing irradiance. Antioxidant level showed different trends for both species: in D. aculeata, antioxidant potential increased with high irradiance and temperature, while in P. palmata, it only increased with high irradiance. Both species showed responses to the interaction of irradiance and temperature, although D. aculeata was more sensitive to high irradiance than P. palmata. Our study shows how these species, which have similar geographical distribution in the North Atlantic and the Arctic but belong to different taxonomic lineages, have similar strategies of acclimation, although they respond differently to ecophysiological parameters.

Database of hourly and daily sums of total radiation at Russian antarctic stations: analysis of changes in total radiation for the entire period of observations in Antarctica

Given the significant changes in the climate on the planet as a whole, databases and archives of data on the main climate-forming characteristics of the atmosphere, collected over long periods of time in various regions of the globe and, in particular, in the polar regions, acquire a special role. Total solar radiation is one of the most important parameters affecting the energy balance of the Earth-atmosphere system. We have created a database (DB) of hourly and daily sums of total radiation (Q) at the Russian Antarctic stations, designed to study the radiation regime of the Antarctic, from the beginning of actinometric observations to 2019. The information presented in the database was collected at five Antarctic stations — Bellingshausen, Vostok Mirny, Novolazarevskaya and Progress. The database has undergone a state registration procedure and is registered under No. 2020621401. The article gives a description of the structure of the DB and presents detailed information for each station. To provide an example of how database information can be used, characteristics of the total radiation in different parts of the Antarctic continent are obtained. Thus, it is found that the average monthly amounts of Q in the continental part of Antarctica on the high plateau (Vostok station) in conditions of minimal cloudiness and high transparency during the Antarctic summer are maximum and average 1240 MJ/m2. At the same time, at the tip of the Antarctic Peninsula (Bellingshausen station) during the same period, the average monthly amounts of Q due to the almost constantly present cloud cover do not exceed 570 MJ/m2. In the coastal areas at the three remaining stations, the average monthly amounts of total radiation range from 908 MJ/m2 (Progress) to 950 MJ/m2 (Mirny). Estimates of variability characteristics of daily, monthly, and annual sums of total radiation at all the five stations for the entire observation period up to 2019 were also obtained. The absence of statistically significant long-term trends in the annual and monthly sums of total radiation at all the stations under consideration was noted. The results of their analysis indicate that there are no significant changes in the inflow of total solar radiation to the Antarctic surface over more than sixty years of actinometric observations.

Time distribution of thunderstorms observed at Odesa AMSC at the beginning of the 21st century

The article presents the results of the research of thunderstorm activity at Odesa AMSC for the period of 2000-2019. Under conditions of intense warming, thunderstorm activity responds to the changes of temperature, humidity, radiation regime and atmospheric composition. Modern climate changes that are characterized by rising air temperatures have a decisive influence on the conditions under which dangerous weather phenomena are formed, thus monitoring of the thunderstorms formation in Ukraine is of great importance. The research includes the analysis of synoptic conditions of thunderstorm activity formation such as air-mass processes, frontal activity, and studies daily and daytime variability of the number of thunderstorm cases for the given period. The results of everyday meteorological observations of atmospheric phenomena conducted by Odesa AMSC within the period of 2000-2019 were used as input data to determine the characteristics of thunderstorm activity over city of Odesa. In order to identify the presence, time and duration of thunderstorm activity aviation weather diaries AV-6 were also reviewed. Certain synoptic materials were used to analyze the types of phenomena. Such materials include interactive database ARMsyn, surface synoptic charts for the periods of observation before and during the thunderstorms. It was established that during the period under study air-mass thunderstorms were formed in 370 cases of thunderstorm activity observed at the given observation post. Frontal thunderstorms occur less often: 241 cases over 20 years. The largest number of such thunderstorms is cold front thunderstorms amounting to 129 cases. 75 of them were identified as occlusion front thunderstorms. The least frequent were warm front thunderstorms – only 37 cases constituting 15% of the total number of frontal formations. During the studied period a total number of 620 thunderstorm cases was recorded, 195 of which are dry thunderstorms. Considerable attention is paid to the daily and daytime variability of thunderstorm cases number recorded by Odesa AMSC. With relation to the daily variation, more thunderstorms are observed during daytime amounting to 393 cases, 130 of which are dry thunderstorms. Night thunderstorms amount to 227 cases, 65 of which are dry thunderstorms. With relation to daytime distribution, more thunderstorms were detected in the afternoon.

Exposure to 2.45 GHz Radiation Triggers Changes in HSP-70, Glucocorticoid Receptors and GFAP Biomarkers in Rat Brain

Brain tissue may be especially sensitive to electromagnetic phenomena provoking signs of neural stress in cerebral activity. Fifty-four adult female Sprague-Dawley rats underwent ELISA and immunohistochemistry testing of four relevant anatomical areas of the cerebrum to measure biomarkers indicating induction of heat shock protein 70 (HSP-70), glucocorticoid receptors (GCR) or glial fibrillary acidic protein (GFAP) after single or repeated exposure to 2.45 GHz radiation in the experimental set-up. Neither radiation regime caused tissue heating, so thermal effects can be ruled out. A progressive decrease in GCR and HSP-70 was observed after acute or repeated irradiation in the somatosensory cortex, hypothalamus and hippocampus. In the limbic cortex; however, values for both biomarkers were significantly higher after repeated exposure to irradiation when compared to control animals. GFAP values in brain tissue after irradiation were not significantly different or were even lower than those of nonirradiated animals in all brain regions studied. Our results suggest that repeated exposure to 2.45 GHz elicited GCR/HSP-70 dysregulation in the brain, triggering a state of stress that could decrease tissue anti-inflammatory action without favoring glial proliferation and make the nervous system more vulnerable.

Intracanopy Lighting in Phytocenoses and Photobiological Efficiency of Radiation in Photoculture Conditions

The review is devoted to the study of the internal radiation regime in the canopies cultivated under controlled environmental conditions. The expediency of using canopies as an object of research for evaluating the photobiological efficiency of radiation in light culture conditions is justified. The appropriateness of light measurements in multi-tiered canopies is shown, taking into account the role of leaves of different tiers in the formation of an economically useful crop. The main requirements for light devices for their use in measuring artificial radiation in light culture conditions are considered, and a brief analysis of the existing instrument base for performing these studies is given. A number of examples show the complexity and ambiguity of the internal structure of the light field that is forming within canopies in light culture conditions. Conceptual approaches to the choice of spectral and energy characteristics of artificial irradiation for plant light culture are proposed and justified. The necessity of taking into account the light conditions of leaves of different tiers when choosing the spectral and energy characteristics of light sources for the cultivation of multi-tiered canopies is justified. Techniques, methods, and light sources used for additional intracanopy lighting are analysed. The efficiency of using side illumination of plant canopies and conditions for its implementation are considered. The advantages of the volume distribution of canopies on the most common multi-tiered lighting installations are discussed. Based on the presented material, we consider ways to improve methodological approaches for evaluating the photobiological effectiveness of artificial radiation in light culture conditions for canopies of cultivated plants, taking into account the features of their architectonics and internal radiation regime.

Assessment of the Thermal Radiation Regime of the Crane Operator Workplace for Making the Reasonable Choice of the Climate System of the Metallurgical Crane Cabin

The tendency of increasing of radiation sources power in metallurgy leads to an increase in the level of thermal radiation at the crane operator workplaces. The state of their health is characterized by a decrease in physical performance, the occurrence of colds, and occupational diseases of the cardiovascular and respiratory systems. Therefore, it is necessary to evaluate the thermal radiation regime of the crane operator workplace for further justification of the choice of the method and means of thermal protection. To assess the thermal irradiation of the metallurgical crane cabin, along with the method of building the thermal irradiation plot, the finite element method was used which was integrated into the automated software package ANSYS, into its plug-in Fluid Flow (Fluent) designed to build models of convective energy transfer by a liquid or gas flow. Flow turbulence is described by the Shear Stress Transport (SST) model. The article examines the thermal radiation situation in the steelmaking shop, which determines the choice of means to ensure an optimal microclimate at the crane operator workplace. It was revealed that the thermal radiation and the temperature of the railings of the metallurgical crane cabin significantly exceed the maximum permissible level, as a result of which it became impossible to choose a climate system that provides for a comfortable air temperature inside the cabin. To reduce the thermal load on the designed climate system, thermal protection elements are introduced into the design of the metallurgical crane cabin, such as a heat-reflecting screen of the floor and side wall and double glazing of the front wall. Then a high-temperature industrial air conditioner was selected, the efficiency of which was confirmed by the results of computer simulation. Thus, for a reasonable choice of the climate system of a metallurgical crane cabin, it is required to have rational combination of the methods and means of thermal protection used at the equipment design stage.

Influence of heliogeophysical factors on patients with myocardial infarction

Introduction: Global climate change is already affecting the health, living conditions, and livelihoods of people on all continents. According to many researchers, the deterioration of the patient's condition is manifested after a solar flare, with the onset of a magnetic storm. Aim: The aim of the article is to study the influence of heliogeophysical factors on the development and outcomes of myocardial infarction. Material and methods: Using data on the effect of space weather on a person from France, Germany, China, Israel, Lithuania, Georgia, a number of Russian clinics – wherever patients with ischemic heart disease were observed, during magnetic storms. Results and discussion: An in-depth study of mortality from myocardial infarction in various climatic and geographical regions showed the dependence of the number of deaths on the season of the year and sharp fluctuations in individual meteorological parameters of the weather to a much greater extent in the year of solar activity. Conclusions: It was found that patients with cardiovascular diseases (CVD) are especially susceptible to heliogeophysical disturbances. The number and severity of CVD depend on many environmental factors (atmospheric pressure, air temperature, cloud amount, ionisation, radiation regime, etc.), a reliable and stable relationship of CVD is revealed with chromospheric flares and geomagnetic storms.

Changes in the radiation regime and photosynthesis in the crown of an apple tree when pruning for perennial wood

The article presents data on the study of the radiation regime and photosynthesis net productivity in the crown of an apple tree in connection with the regenerative pruning of old-aged trees. The object of the research was an apple tree of the Antonovka obyknovennaya variety, a seed stock (seedlings of cultivated varieties), planted in 1987. The test plot soil is leached chernozem. Options: 1. Established pruning (control); 2. Pruning for 5-6 year-old wood; 3. Pruning for 7-8 year-old wood. The experiment was arranged inrandomized blocks of 6 accounting trees in 3 replicates. The regenerative pruning was carried out in spring 2016. Every year damaged branches were removed in the control variant, while “wolf-like” shoots were thinned in other variants. The solar output was accounted within the daytime with the 2-hour interval from the northern and southern sides of the apple tree crown in its center, as well as under the crown at a distance of 1, 2 and 3 meters from the periphery to the center of the crown. The measurements were carried out after the growth activity cessation in the fine weather in August with a universal albedometer M-69 coming with a galvanometer GSA-1. The net productivity of leaves was determined by the method of A. S. Ovsyannikov in parallel, taking into account solar radiation. It is revealed that the regenerative pruning has a considerable impact on the performance of the solar output. The greatest arrival of solar radiation is noted on the periphery of the crown. In the treatment with pruning branches for 5-6 year-old wood, this parameter was 10.5-13.5 % higher than in the control variant. Pruning branches for 7-8 year-old wood improved lighting conditions by 27.6-31.7 % compared to the control. In the lower part of the crown, the radiation regime is less favorable for the photosynthesis process relative to the central part of the crown. Regenerative pruning increased the photosynthesis productivity significantly. In the central part of the crown, the highest parameters of the net photosynthesis productivity were observed on the periphery on the southern side when pruning for 7-8 year-old wood - 7.81 g of dry basis/m2 *day.