Glucocorticoids (GCS) are known to modulate cardiovascular response during stress conditions. The present study was aimed to test the hypothesis that permissive and/or stimulating effect of GCs is essential for the maintenance of peripheral vascular resistance and for the adequate response of cardiovascular system to stressor exposure. The effects of acute pharmacological adrenalectomy (PhADX) on humoral and cardiovascular parameters were studied in adult Wistar rats under the basal conditions and during the acute restraint stress. Acute PhADX was performed by the administration of metyrapone and aminoglutethimide (100 mg/kg s.c. of each drug) resulting in a suppression of endogenous glucocorticoid synthesis. Blood pressure (BP), heart rate (HR) and core body temperature were measured using radiotelemetry. BP responses to administration of vasoactive agents were determined in pentobarbital-anesthetized animals. PhADX considerably attenuated stress-induced increase of BP, HR and core body temperature. PhADX did not abolish BP and HR lowering effects of ganglionic blocker pentolinium indicating preserved sympathetic function in PhADX rats. BP response to exogenous norepinephrine administration was attenuated in PhADX rats, suggesting reduced sensitivity of cardiovascular system. Suppression of corticosterone synthesis by PhADX increased basal plasma levels of ACTH, aldosterone and plasma renin activity in unstressed animals but there was no further increase of these hormones following stressor exposure. In conclusion, PhADX attenuated stress-induced rise of blood pressure, heart rate and core body temperature indicating an important permissive and/or stimulating role of glucocorticoids in the maintenance of the adequate response of cardiovascular system and thermoregulation to several stimuli including acute exposure to stressor.
72 to 120 h of soil flooding of barley plants (Hordeum vulgare L. cv. Alfa) led to a noticeable decrease in the rates of CO2 assimilation and transpiration, and in chlorophyll and dry mass contents. Stomatal conductance decreased following flooding without appreciable changes in the values of intercellular CO2 concentrations. A drop in the activity of ribulose-1,5-bisphosphate carboxylase (EC 4.1.1.39) and of the photorespiratory enzymes phosphoglycollate phosphatase (EC 3.1.3.18) and glycollate oxidase (EC 1.1.3.1) was observed, while the activity of phosphoenolpyruvate carboxylase (EC 4.1.1.31) increased in all flooded plants. Flooding of barley plants caused an increase in proline content and in leaf acidity. and R. Y. Yordanova, L. P. Popova.
A greenhouse experiment was conducted to study the indirect effects of soil salinity on a caterpillar that induces gall formation on a non-halophilic plant. Larvae of Epiblema scudderiana (Clemens) were allowed to feed on potted goldenrods (Solidago altissima L.) treated with 3 concentrations of NaCl (0, 8,000, 16,000 PPM). Experiments were also carried out with the larvae of two species of leaf beetles, Trirhabda borealis Blake, a leaf-chewer, and Microrhopala vittata F., a leaf-miner, to determine the influence of feeding guild. Adding salt to the soil affected both the plant and insect herbivores. The biomass of roots and shoots as well as root/shoot ratios of salt-stressed plants were lower, relative to controls. The biomass of the fully grown larvae and galls were decreased for the plants treated with the highest salt concentration. The percentage of biomass allocated to the gall was increased by soil salinity. All gall-inducing larvae completed their development (from second to final instar) even though their biomass was significantly reduced in the 16,000 PPM treatment. Soil salinity increased nitrogen concentrations in both gall and stem (normal) tissues but the levels were always higher in the gall. The salt treatments also increased sodium and potassium concentrations in galls and stems. Interestingly, sodium concentrations as well as the ratio of sodium ions to potassium ions increased more rapidly in the stem compared with the gall. Responses of folivorous insects to salt-stressed plants varied. Leaf-chewing larvae ate smaller amounts of plant tissue with high salt content compared with control, which also resulted in shorter feeding periods. The performance of the leaf-mining insect was not affected. However, it was able to complete its larval development within a smaller portion of the leaves. This study showed that soil salinity has a strong negative effect on S. altissima, especially on root development. Conversely, salt stress effects seemed to be progressively decreasing from the stem to the gall to the gall-inducer, which suggests that the gall tissue might act as a buffer against drastic changes in the mineral balance of the host plant. Nevertheless, it seems that unless the host plant dies, larvae of E. scudderiana can always produce a gall in which they can complete their development. On the other hand, leaf-chewing insects appeared to be sensitive to salt-rich tissues since they were deterred by them. Leaf-miners could complete their development with fewer food without any effect on their growth, suggesting that the peculiar tissues on which they feed within leaves became more abundant or nutritious in salt-treated plants.
Objectives. The global pandemic of COVID-19 represents a major stressor in the lives of health-care professionals. The present study investigat-ed experienced stress and self-reported trauma symptoms among Slovak nurses during the fall of 2020, aiming to describe the extent of expe-rienced stress and trauma, and explain the vari-ation in trauma symptoms using psychosocial predictors. Sample and settings. An online form measuring traumatic stress symptoms, social support, cop-ing strategies, sleep quality and overall experi-enced stress was distributed among nurses and other healthcare professionals. 565 participants responded between November 12th and Decem-ber 20th 2020. Statistical analyses. Several multiple linear re-gressions with demographic and psychosocial predictors were performed to explain variation in traumatic symptoms.Results. The present data shows that 83% of medical nurses perceived increased stress and more than 62% experienced trauma symptoms. Traumatic symptoms could be partly explained based on the participants’ age, perceived social support, and used coping strategies. Higher so-cial support and strategies of acceptance and positive reframing were related to fewer trauma symptoms, while avoidance strategies, such as self-distraction, self-blame, venting, and behav-ioral disengagement to more trauma symptoms. In line with the present findings, professional psychosocial support is important to alleviate stress and prevent traumatization in healthcare workers after the COVID-19 crisis.Limitations. Data were collected via an online form, with a sample consisting of mostly nurses and women lacking data on other medical pro-fessions and men. Finally, traumatic symptoms develop slowly, therefore it is not possible to measure their recovery at this point. and Globálna pandémia ochorenia covid-19 pred-stavuje závažný stresor v životoch zdravot-níckych pracovníkov. Táto štúdia skúmala prežívaný stres a traumatické symptómy u slo-venských zdravotných sestier počas jesene 2020, s cieľom popísať ich rozsah a vysvetliť variáciu v symptómoch traumy na základe psy-chosociálnych prediktorov. Zber dát prebiehal prostredníctvom online formulára distribuova-ného zdravotným sestrám. Súčasťou formulára boli škály na meranie symptómov traumatické-ho stresu (TSQ-10), prežívanej sociálnej opory (MSPSS), copingových stratégií (Brief COPE), kvality spánku (PSQI) a celkového prežívaného stresu (PSS-10). Počas zhoršujúcej sa druhej vlny pandémie, medzi 12. novembrom a 20. decembrom 2020 na formulár odpovedalo 565 zdravotných sestier. Na vysvetlenie variácie traumatických symptómov bolo vytvorených niekoľko lineárnych regresných modelov ob-sahujúcich demografické a psychosociálne prediktory. Získané dáta ukázali, že 83 % zdra-votných sestier vnímalo v danom období, že sú pod zvýšenou mierou stresu, a viac ako 62 % sa prejavovalo traumatickými symptómami. Traumatické symptómy možno čiastočne vy-svetliť na základe veku participantov, vnímanej sociálnej opory a použitých stratégií zvládania. Vyššia sociálna podpora a stratégie prijatia a pozitívneho prerámcovania súviseli s men-ším počtom traumatických symptómov, zatiaľ čo vyhýbavé stratégie, ako sú sebarozptýlenie, sebaobviňovanie, ventilovanie a odangažované správanie, súviseli s väčším množstvom trau-matických symptómov. Limitmi výskumu sú zber prostredníctvom online formulára, vzorka zložená prevažne zo sestier ženského pohlavia, bez údajov o iných zdravotníckych profesiách a o mužoch. Napokon, traumatické symptómy sa vyvíjajú pomaly, preto v tomto bode nie je možné zmerať ich zotavenie. V súlade so súčas-nými zisteniami je dôležitá odborná psychoso-ciálna podpora na zmiernenie stresu a preven-ciu traumatizácie zdravotníckych pracovníkov po kríze covid-19.
The extrinsic proteins of photosystem II in plants (PsbO, PsbP and PsbQ) are known to be targets of stress. In previous work, differential regulation of hypothetical isoforms of these proteins was observed in Nicotiana benthamiana upon viral infection. Each of these proteins is encoded by a multigene family in this species: there are at least four genes encoding PsbO and PsbP and two encoding PsbQ. The results of structural and functional analyses suggest that PsbO and PsbP isoforms could show differences in activity, based on significant substitutions in their primary structure. Two psbQ sequences were isolated which encode identical mature proteins. and M. I. Pérez-Bueno ... [et al.].
Experimentální a kazuistické studie prokázaly bezprostřední i dlouhodobé důsledky výživy na psychické zdraví a chování člověka. Tato srovnávací studie se zaměřila na zkoumání souvislostí mezi stravovacími zvyklostmi a zvládáním stresu. Výzkumné otázky zjišťovaly statistickou významnost rozdílů mezi lidmi stravujícími se makrobioticky a osobami stravujícími se způsobem většinové populace ve výsledcích dotazníku SOC (Antonovsky, 1993) a dotazníku PVS (Kobasa, 1985). Výzkumný soubor byl vybrán metodou kvót a činil 64 probandů. Kontrolní skupina byla sestavena metodou párování podle věku, pohlaví, vzdělání a stylu stravování. T – test pro dva nezávislé výběry ukázal statisticky signifikantní rozdíly ve výsledných celkových skórech dotazníku SOC (p<0,05) i dotazníku PVS (p<0,01). and Experimental and case studies proved immediate and long term effects of nutrition on human behavior and mental health. This comparative study focused on the connection between eating habits and coping with stress. Research questions identified statistically significant differences between people eating macrobiotics and those with majority eating habits in results of the Sense of Coherence Scale (Antonovsky, 1993) and Personal Views Survey (Kobasa, 1985). The research was done using the quota sample of university students of humanities (N = 64, 32 males, 32 females, age 20 - 30). The control group was composed with the method of pairing according to age, sex, education and dietary behavior. T-test for independent samples showed statistically significant differences in total scores of the Sense of Coherence Scale (p<0,05) and Personal Views Survey (p<0,01).
Problematice stresu je věnována značná pozornost. Proto je třeba mít k dispozici jednoduchý a přitom spolehlivý nástroj umožňující stanovit aktuální hladinu stresu. Cílem tohoto příspěvku je představit prvotní psychometrické ověření české verze Škály vnímaného stresu vyvinuté původně Cohenem v roce 1983, která je v tomto směru jednou z nejčastěji užívaných metod. Ověření dotazníku obsahujícího 10 položek bylo realizováno na vzorku zahrnujícím 358 respondentů z řad studentů vysokých škol. Statistické zpracování zahrnovalo mimo jiné i stanovení vnitřní konzistence dotazníku a konfirmační faktorovou analýzu. Česká verze dotazníku vykazovala vysokou míru vnitřní konzistence, když Cronbachovo alfa bylo 0,871. Konfirmační faktorová analýza potvrdila v literatuře preferovanou dvoufaktorovou strukturu dotazníku a ukázala, že uvedený model dosahuje vyhovujících výsledků v absolutních i relativních indexech shody modelu s daty stejně jako v indexech vystihujících úspornost modelu. Česká verze Škály vnímaného stresu je tak reliabilním a validním nástrojem umožňujícím měření aktuální hladiny vnímaného stresu. and Recently, a great attention has been devoted to stress. Thus, it is worth to have a simple and reliable tool measuring the current level of perceived stress. The aim of this paper is to present a validation of the Czech version of the Perceived Stress Scale which was developed by Cohen in 1983 and is a widely used instrument in this field. Verification of the questionnaire containing 10 items was carried out on a group of 358 university students. The statistical analysis included besides other things determination of the internal consistency and confirmatory factor analysis. The Czech version exhibited a high level of internal consistency with Cronbach´s alpha of 0.871. Confirmatory factor analysis revealed a two-factor structure preferred also in the literature and showed adequate values of both absolute and relative fit indices as well as indices of parsimony. The Czech version of the Perceived Stress Scale is valid and reliable instrument enabling measurement of perceived stress.
Sonic booms or disruptive explosions cause differing response in wildlife. In May 2021, when missiles were fired at urban areas in Israel, we observed the responses of breeding common swifts (Apus apus). In both nests, the initial boom resulted in a startled awakening of the swifts. In one case, a parent engaged in displacement behaviour of feeding the young while in the second case a parent tried to clamber up the walls. Our data support earlier studies that although auditory booms are disruptive, they do not result in nest abandonment or nest failure.
The effects of UV-B radiation (1 W m-2, 1 and 2 h) on PSII activity, chloroplast structure, and H2O2 contents in leaves of 26-d-old Arabidopsis thaliana phyA phyB double mutant (DMut) compared with the wild type (WT) were investigated. UV-B decreased PSII activity and affected the H2O2 content in WT and DMut plants grown under white light (WL). The chloroplast structure changes in DMut plants exposed to UV were more significant than that in WT. Reductions in maximal and real quantum photochemical yields and increase in the value of thermal dissipation of absorbed light energy per PSII RC and the amount of QB-nonreducing centers of PSII were bigger in mutant compared to WT plants grown both under WL and red light. Such difference in action of UV-B on WT and DMut can be explained by higher content of UV-absorbing pigments and carotenoids in WT leaves compared with DMut., V. D. Kreslavski, A. N. Shmarev, V. Yu. Lyubimov, G. A. Semenova, S. K. Zharmukhamedov, G. N. Shirshikova, A. Yu. Khudyakova, S. I. Allakhverdiev., and Obsahuje bibliografické odkazy
Uranium deposits, between which gas storage are being designed, the Rožná deposit and Olší deposit, are situated on the east edge of the Strážek Moldanubicum in Bohemian Masiff. Based on structural analysis it was possible to carry out the first rough prediction of potential weak zones in the rock mass. The structural analysis was also one of the supporting materials for determining the geometry and design method for the mine workings for the gas storage and for the advancing exploration of the gas storage region. Until now, the measurement of foliation planes and discontinuity planes in the survey crosscut V1-XXI and in a survey connecting gate GR1-XXI has been carried out. The results of interpretation of the measurement and monitoring of ductile elements (foliations) and joints (ruptures) as well as dislocations interpretation from the mine maps can be summarized and quoted in the contribution., Jiří Ptáček, Rostislav Melichar, Antonín Hájek, Petr Koníček, Kamil Souček, Lubomír Staš, Petr Kříž and Josef Lazárek., and Obsahuje bibliografii