Emotion regulation has important implications for individual and relationship health. Psychophysiological responses, such as respiratory sinus arrhythmia (RSA), can serve as a key indicator of ...emotion regulation processes subsequent to a stressor and may be the process by which couples confer health benefits. Moreover, partners in romantic relationships can mutually impact physiological states both during times of stress and times of support. The current study examined physiological reactivity through RSA during a laboratory stress‐induction (i.e., stressful‐film trauma analog) and recovery within the context of a romantic relationship. Sex, relationship health, and individual mental health indicators were examined as moderators of reactivity and recovery. Forty‐five (n = 90 individuals) community couples, primarily White (n = 75, 83.3%), heterosexual (n = 63, 70.0%), and dating (n = 67, 74.4%), were examined. Both partners' RSA were measured continuously through a series of baseline tasks, a stressful‐film task, and a post‐film interaction task. Reactivity and recovery trajectories were moderated by sex, study task (i.e., baseline, film, and post‐film), and individual mental health (ps < .05). Repeated‐measures actor partner interdependence modeling analyses revealed a strong self‐regulatory (i.e., actor) effect across all tasks as well as co‐regulation (i.e., partner effects) during the post‐film interaction task. Findings provided some evidence of stress transmission to the non‐exposed partner. This study offers initial evidence of self‐ and co‐regulation following a laboratory stress‐induction and potential predictors and moderations of the set point and stability of these regulatory dynamics. Implications and future directions are discussed.
Psychophysiological responses, such as respiratory sinus arrhythmia, can serve as a key indicator of emotion regulation processes following acute stress and may be one of the processes by which couples confer health benefits. Our findings provide a novel and nuanced understanding of self‐ and co‐regulation dynamics as well as potential stress transmission within the context of a romantic relationship following acute stress induction. Moreover, several moderators of physiological reactivity and recovery trajectories were identified by using a trauma‐analog paradigm.
•Dislocation, amorphous and nanocrystal are the mechanisms of plastic deformation of tungsten.•Tungsten surface forms nanocrystals under UEVC compared with common cutting.•The instantaneous shear ...stress of UEVC is three times that of common cutting.•The relationship between shear stress and microstructure evolution in UEVC is given.•The microstructure evolution mechanism of tungsten induced by UEVC is revealed.
Ultrasonic elliptical vibration cutting (UEVC) technology has been utilized for ultra-precision machining of difficult-to-machine metal materials such as tungsten. Nevertheless, the microstructure evolution mechanism of tungsten under the synergistic effect of ultrasonic and mechanical loads remains unclear, particularly at the atomic/nano scale. Additionally, the plastic deformation mechanism of tungsten differs from that of other metallic materials due to its low dislocation mobility (brittle at room temperature). Hence, the molecular dynamics simulation of UEVC for single crystal tungsten was established to study its mechanisms in plastic deformation and microstructure evolution under stress induction in this study. The results indicated that the main plastic deformation mechanisms including dislocation slip, amorphous phase transformation and nanocrystal were found during the tungsten removal, and accompanied by some extent of lattice distortion. The instantaneous shear stress of UEVC reached 16.88 GPa. Compared with common cutting (CC), the formation of nanocrystals mainly occurred in UEVC because the instantaneous shear stress exceeded the critical shear stress of multiple slip systems during cutting. Similarly, the high dislocation density and high plastic deformation degree of the machined zone in UEVC were also attributed to the high shear stress. The dynamic recrystallization of tungsten induced by UEVC was realized from dislocation slip to the formation of dense dislocation walls, followed by the formation of sub-grain boundaries, and finally to the formation of nanocrystals.
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•Astaxanthin production in H. pluvialis induced by high light intensity and 15% CO2.•Effective astaxanthin induction achieved without using nutrient deficient media.•The reported ...astaxanthin production approach has economical and efficient merits.
In this study, an economical two-stage method was proposed for the production of natural astaxanthin from Haematococcus pluvialis without a medium replacement step. In stage 1, H. pluvialis were grown under low light illumination until they reached optimal biomass. In stage 2, cells were switched to astaxanthin induction conditions utilizing the combination of high light illumination and elevated carbon dioxide levels (5 or 15%). The introduction of CO2 altered the C/N balance creating a nutrient deficiency without a change of media. The resulting astaxanthin yield was 2–3 times that of using either stressor alone. This astaxanthin induction method has many advantages over current methods including no medium replacement and a short induction time of less than four days.
Stressful experiences are abundant in university and students with a history of nonsuicidal self-injury (NSSI) may be hyper-reactive to stress. While brief mindfulness inductions have been proposed ...as a buffer against acute stress, whether they function differently in students with a history of NSSI remains in question. This study sought to explore the impact of an online mindfulness induction on (a) two facets of state mindfulness (i.e., mind and body) and (b) state stress, following a stress induction task, in university students with versus without a history of NSSI. Participants were Canadian university students with (n = 82; Mage = 21.30 years, SD = 2.92; 87.8% female) and without (n = 82; Mage = 21.71 years, SD = 3.18; 87.8% female) a history of NSSI, matched on gender, age, and faculty, who completed baseline (T1) measures of state stress and state mindfulness. Participants were randomly assigned to complete a mindfulness induction or an active control task. All participants then underwent a stress induction, and again completed measures of state stress and state mindfulness (T2). Results from three-way mixed ANOVAs revealed that state stress increased from T1 to T2 for all participants, regardless of group or condition. Among those assigned to the control condition, state mindfulness of the body was lower at T2 for participants with a history of NSSI compared to those without such a history. However, participants with a history of NSSI who completed the mindfulness induction reported greater state mindfulness of the body at T2 than students with a history of NSSI who completed an active control task. Findings highlight the unique response of university students with a history of NSSI to a brief mindfulness induction. Implications are discussed in the context of future research and clinical applications.
•The underlying neural mechanisms of cannabis use disorder (CUD) are unclear.•Distress intolerance (DI) is believed to be a psychological risk factor for CUD.•N2 is an inhibitory control-related ...event-related potential associated with DI.•In this longitudinal study, participants received a DI or a control intervention.•Blunted N2 after acute stress acts as a stable marker of CUD severity.
The prevalence of cannabis use in the US has increased within the past two decades. Moreover, cannabis use disorder (CUD) is associated with significant disability, but the underlying neural mechanisms of CUD are unclear. Distress intolerance (DI), a psychological risk factor for CUD, may confer risk in part via impaired inhibitory control (IC) capacity during acute stress. DI and cannabis use problems have been associated with altered N2 amplitude, an IC-related event-related potential, in prior cross-sectional studies, but whether altered N2 is a state marker of CUD severity, a pathoplastic factor responsive to intervention and predictive of CUD symptom change over time, or an enduring trait-like vulnerability is unclear. In this secondary analysis, we tested the impact of a DI-targeted intervention on acute stress-related modulation of the N2 and whether pre-intervention N2 predicted CUD symptom change through follow-up.
Sixty participants were randomly assigned to a DI-targeted or control intervention. Participants completed an IC task before and after a stress induction at pre- and post-intervention lab visits while EEG activity was recorded.
The DI intervention did not alter the N2 compared to a control intervention. Pre-intervention post-stress IC-related N2 was associated with worse CUD severity but did not predict changeover time.
Findings are consistent with blunted N2 after acute stress acting as a stable marker of CUD severity rather than a pathoplastic factor predictive of CUD trajectory. Future research should investigate whether stress-related blunting of N2 is a consequence of severe CUD or a pre-existing vulnerability.
Compared to the in-person Trier Social Stress Test (TSST), virtual reality (VR) variants reduce resource-intensity and improve standardization but induce stress with smaller effect sizes. However, ...higher cortisol reactivity is given for more immersive TSST-VRs. Immersivity depends on the VR-system, but perceived immersion may be targeted by exposure to, or interaction with the VR. We investigated whether stress reactivity towards the openly accessible OpenTSST VR can be enhanced by prior exposure to a sensorimotor game completed in VR as mediated by increased immersion. Therefore, N = 58 healthy participants underwent the OpenTSST VR or its inbuilt control condition (placebo TSST-VR, pTSST-VR). Beforehand, participants completed a sensorimotor game either in VR or in real life. Stress was measured by means of self-reports, salivary cortisol concentrations, and salivary alpha-amylase (sAA) activity. Perceived immersion was assessed with the Igroup Presence Questionnaire (IPQ). The TSST-VR-group showed higher subjective stress than the pTSST-VR-group. Even though area under the curve measures indicated significant differences in cortisol levels between TSST-VR and pTSST-VR, this effect was not replicated in omnibus-analyses. Likewise, sAA was not responsive to stress. Our data suggests the OpenTSST VR does not reliably trigger physiological stress reactivity. Likewise, participants playing the VR-game before exposure to the TSST-VR did not show enhanced stress reactivity. Importantly, playing the VR-game did not lead to increased immersion (indicated by the IPQ), either. The key question resulting from our study is which manipulation may be fruitful to obtain a comparable stress response toward the TSST-VR compared to the in-person TSST.Compared to the in-person Trier Social Stress Test (TSST), virtual reality (VR) variants reduce resource-intensity and improve standardization but induce stress with smaller effect sizes. However, higher cortisol reactivity is given for more immersive TSST-VRs. Immersivity depends on the VR-system, but perceived immersion may be targeted by exposure to, or interaction with the VR. We investigated whether stress reactivity towards the openly accessible OpenTSST VR can be enhanced by prior exposure to a sensorimotor game completed in VR as mediated by increased immersion. Therefore, N = 58 healthy participants underwent the OpenTSST VR or its inbuilt control condition (placebo TSST-VR, pTSST-VR). Beforehand, participants completed a sensorimotor game either in VR or in real life. Stress was measured by means of self-reports, salivary cortisol concentrations, and salivary alpha-amylase (sAA) activity. Perceived immersion was assessed with the Igroup Presence Questionnaire (IPQ). The TSST-VR-group showed higher subjective stress than the pTSST-VR-group. Even though area under the curve measures indicated significant differences in cortisol levels between TSST-VR and pTSST-VR, this effect was not replicated in omnibus-analyses. Likewise, sAA was not responsive to stress. Our data suggests the OpenTSST VR does not reliably trigger physiological stress reactivity. Likewise, participants playing the VR-game before exposure to the TSST-VR did not show enhanced stress reactivity. Importantly, playing the VR-game did not lead to increased immersion (indicated by the IPQ), either. The key question resulting from our study is which manipulation may be fruitful to obtain a comparable stress response toward the TSST-VR compared to the in-person TSST.
Since the COVID-19 pandemic, working environments and private lives have changed dramatically. Digital technologies and media have become more and more important and have found their way into nearly ...all private and work environments. Communication situations have been largely relocated to virtual spaces. One of these scenarios is digital job interviews. Job interviews are usually-also in the non-digital world-perceived as stressful and associated with biological stress responses. We here present and evaluate a newly developed laboratory stressor that is based on a digital job interview-scenario.
= 45 healthy people participated in the study (64.4% female; mean age: 23.2 ± 3.6 years; mean body mass index = 22.8 ± 4.0 kg/m
). Salivary alpha-amylase (sAA) and cortisol were assessed as measures for biological stress responses. Furthermore, perceived stress was rated at the time points of the saliva samplings. The job interviews lasted between 20 and 25 min. All materials, including instructions for the experimenter (i.e., the job interviewer) and the data set used for statistical analysis, as well as a multimodal data set, which includes further measures, are publicly available.
Typical subjective and biological stress-response patterns were found, with peak sAA and perceived stress levels observed immediately after the job interviews and peak cortisol concentrations 5 min afterwards. Female participants experienced the scenario as more stressful than male participants. Cortisol peaks were higher for participants who experienced the situation as a threat in comparison to participants who experienced it as a challenge. Associations between the strength of the stress response with further person characteristics and psychological variables such as BMI, age, coping styles, and personality were not found.
Overall, our method is well-suited to induce biological and perceived stress, mostly independent of person characteristics and psychological variables. The setting is naturalistic and easily implementable in standardized laboratory settings.
Oxidative stress is an important cause of respiratory diseases associated with exposure to PM2.5. Accordingly, acellular methods for assessing the oxidative potential (OP) of PM2.5 have been ...evaluated extensively for use as indicators of oxidative stress in living organisms. However, OP-based assessments only reflect the physicochemical properties of particles and do not consider particle-cell interactions. Therefore, to determine the potency of OP under various PM2.5 scenarios, oxidative stress induction ability (OSIA) assessments were performed using a cell-based method, the heme oxygenase-1 (HO-1) assay, and the findings were compared with OP measurements obtained using an acellular method, the dithiothreitol assay. For these assays, PM2.5 filter samples were collected in two cities in Japan. To quantitatively determine the relative contribution of the quantity of metals and subtypes of organic aerosols (OA) in PM2.5 to the OSIA and the OP, online measurements and offline chemical analysis were also performed. The findings showed a positive relationship between the OSIA and OP for water-extracted samples, confirming that the OP is generally well suited for use as an indicator of the OSIA. However, the correspondence between the two assays differed for samples with a high water-soluble (WS)–Pb content, which had a higher OSIA than would be expected from the OP of other samples. The results of reagent-solution experiments showed that the WS-Pb induced the OSIA, but not the OP, in 15-min reactions, suggesting a reason for the inconsistent relationship between the two assays across samples. Multiple linear regression analyses and reagent-solution experiments showed that WS transition metals and biomass burning OA accounted for approximately 30–40% and 50% of the total OSIA or the total OP of water-extracted PM2.5 samples, respectively. This is the first study to evaluate the association between cellular oxidative stress assessed by the HO-1 assay and the different subtypes of OA.
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•Oxidative stress induced by PM2.5 was evaluated by cellular and acellular methods.•Biomass burning was mainly responsible for oxidative stress by PM2.5 in urban areas.•Cellular and acellular methods for oxidative stress were generally comparable.•Acellular methods occasionally underestimated PM with high Pb content.•Reaction time is an important consideration in comparisons of both methods.
•Tomato, potato and eggplant are important solanum crops severely affected by drought.•Water stress can be induced and assessed with several methods and conditions.•The review highlights the ...advantages and disadvantages of each method for the three crops.•Effects on growth, biomass, physiological and biochemical traits are reviewed.•The effect of combined stress and the potential of wild relatives are considered.
The genus Solanum encompasses several economically important vegetable crops, such as tomato, potato, and eggplant, which are crucial for ensuring food security. Higher temperatures and reduced precipitation are becoming more frequent due to climate change in numerous regions, fostering drought spells and the likelihood of water stress in Solanum crops resulting in decreased yields. Appropriate evaluation techniques are required by researchers and breeders to evaluate the impact of drought on the performance of Solanum crops and identify more tolerant genotypes. This review examines the most important approaches for inducing water stress in Solanum crops, such as withholding irrigation, adjusting field capacity levels, applying evapotranspiration criteria, and utilizing polyethylene glycol as an osmotic agent. We highlight the benefits and drawbacks of each method, enabling researchers and breeders to choose the most suitable conditions for their specific objectives and goals. Additionally, we address the challenges of combining water stress with other types of stress that frequently occur simultaneously in the field and the effects that biostimulants can have in mitigating water stress in Solanum crops. We also provide an in-depth analysis of the impact of water deficit on growth and biomass, as well as on physiological and biochemical traits, and new phenotyping tools that allow the study of stress tolerance in the three major crops belonging to the Solanum genus. Finally, the review discusses the possibility of utilizing wild species to improve water stress tolerance in these Solanum crops.
This investigation centers on the synthesis of a polysaccharide-protein blend produced by an isolated native strain (99.12 % phylogenetic affinity with Bacillus arachidis SY8(T)). The primary ...objective was to investigate the production of extracellular polymeric substances (EPS) under diverse stress conditions, encompassing exposure to heavy metal ions, salt, and toxic agents. Additionally, the impact of environmental parameters, namely pH, inoculation percentage, and time, on the production was investigated. Subsequently, the study examined the biosorption potential of the EPS produced for Pb(II), Cu(II), and Mn(II). The EPS obtained was thoroughly characterized via various tests. Rheological evaluations of an EPS solution (2 wt%) confirmed its pseudo-plastic and non-Newtonian fluid properties, while TGA analysis demonstrated its thermal stability up to 600 °C. Additional analyses, including GPC, FTIR, and H-NMR, provide further insights into the produced EPS. The best conditions for EPS production are determined: 5 % NaCl salt, serving as an effective stress inducer, and 37 °C, pH 6, with a 5 % inoculation, over 96 h. EPS demonstrates remarkable removal efficiencies of 99.9, 99.4 and 78.9 % for Pb(II), Cu(II), and Mn(II), respectively. These findings highlight the potential of EPS as an effective agent for removing heavy metal ions.
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•Biosynthesis of EPS by B. arachidics (isolated from soil) was performed.•EPS production was increased from 1.8 to 7.8 g/l in the presence of 5 % NaCl.•Conditional factors played a pivotal role in influencing EPS production.•In-depth EPS characterization provides comprehensive insights into its properties.•Significant heavy metal removal (e.g. 99.43 % for Cu(II)) demonstrated EPS efficacy.
