Stress exposure, perceived stress, protective psychosocial factors, and health status in Ukraine after the full-scale invasion.

The concept of stress as a cause of ill health has received much attention in social sciences. The distinction between stress exposure and perceived stress emphasizes the importance of cognitive dimension of stress. This quantitative study (N = 213) conducted in Ukraine in November 2022 collected self-reported cognitive data on stress exposure, perceived stress, and self-rated heath. The goals of the study included (1) testing if stress exposure and perceived stress differ in terms of breadth and depth of their impact; (2) isolating psychosocial factors that reduce stress; and (3) testing if individuals who have relocated within Ukraine or abroad to escape the war had worse health outcomes than those who remained at their domiciles. The results suggest that while perceived stress was a stronger predictor of negative health outcomes, optimism and social support served as protective psychosocial factors. Having moved abroad predicted higher stress levels and more adverse health symptoms.

Lipid accumulation by Coelastrella multistriata (Scenedesmaceae, Sphaeropleales) during nitrogen and phosphorus starvation.

A novel freshwater strain of Coelastrella multistriata MZ-Ch23 was discovered in Tula region, Russia. The identification is based on morphological features, phylogenetic analysis of SSU rDNA gene and ITS1-5.8S rDNA-ITS2 region and predicted secondary structure of the ITS2. Phylogenetic analysis places the novel strain in the "core" Coelastrella clade within the Chlorophyceae. This is the first record of Coelastrella multistriata in the algal flora of Russia. Cultivation experiments were carried out to evaluate growth dynamics of the newly identified strain and the impact of nitrogen and/or phosphorus depletion on the fatty acid profiles and lipid productivity. On the fully supplemented Bold's basal medium and under phosphorus-depleted conditions as well, the fatty acid profiles were dominated by α-linolenic acid (29.4-38.1% of total fatty acids). Depletion of either nitrogen or both nitrogen and phosphorus was associated with increased content of oleic acid (32.9-33.7%) and linoleic acid (11.9%). Prolongation of the growth to two months (instead of 25 days) resulted in increased content and diversity of very long-chain fatty acids including saturated species. The total very long-chain fatty acid content of 9.99% achieved in these experiments was 1.9-12.3-fold higher than in stress experiments. The highest variation was observed for oleic acid (3.4-33.7%). The novel strain showed the ability to accumulate lipids in amounts up to 639.8 mg L-1 under nitrogen and phosphorus starvation, which exceeds the previously obtained values for most Coelastrella strains. Thus, the newly identified MZ-Ch23 strain can be considered as a potential producer of omega-3 fatty acids on fully supplemented Bold's basal medium or as a source of biomass with high content of saturated and monounsaturated fatty acids after nitrogen and phosphorus starvation.

Influence of Light Conditions on Microalgae Growth and Content of Lipids, Carotenoids, and Fatty Acid Composition.

Microalgae are a valuable natural resource for a variety of value-added products. The growth of microalgae is determined by the impact of many factors, but, from the point of view of the implementation of autotrophic growth, light is of primary importance. This work presents an overview of the influence of light conditions on the growth of microalgae, the content of lipids, carotenoids, and the composition of fatty acids in their biomass, taking into account parameters such as the intensity, duration of lighting, and use of rays of different spectral composition. The optimal light intensity for the growth of microalgae lies in the following range: 26-400 µmol photons m-2 s-1. An increase in light intensity leads to an activation of lipid synthesis. For maximum lipid productivity, various microalgae species and strains need lighting of different intensities: from 60 to 700 µmol photons m-2 s-1. Strong light preferentially increases the triacylglyceride content. The intensity of lighting has a regulating effect on the synthesis of fatty acids, carotenoids, including ß-carotene, lutein and astaxanthin. In intense lighting conditions, saturated fatty acids usually accumulate, as well as monounsaturated ones, and the number of polyunsaturated fatty acids decreases. Red as well as blue LED lighting improves the biomass productivity of microalgae of various taxonomic groups. Changing the duration of the photoperiod, the use of pulsed light can stimulate microalgae growth, the production of lipids, and carotenoids. The simultaneous use of light and other stresses contributes to a stronger effect on the productivity of algae.