Important Stressors Research Articles

After the storm, the calm never came: Hurricane Maria-related stressors and PTSD symptoms among Puerto Rican youth.

Youth may develop posttraumatic stress disorder (PTSD) following a hurricane. Triaging of mental health services is crucial to effectively deliver trauma-focused interventions following natural disasters. Given the increased likelihood of hurricanes due to the current climate crisis, this study sought to examine the dose-response effect between hurricane-related stressors and PTSD, identify a cumulative stressor cutoff score based on the number of hurricane-related stressors experienced, and identify important individual hurricane-related stressors in explaining PTSD symptoms among youth. Participants included 92,293 youth (Grades 3-12) who completed a needs-based assessment in schools across Puerto Rico 5-9 months following Hurricane Maria. Machine learning analyses were used to examine the relationship between hurricane-related stressors and the severity and elevated levels of PTSD. Youth who endorsed more disaster-related exposures exhibited greater severity and elevated levels of PTSD symptoms. A cutoff of seven or more cumulative stressors best discriminated between youth with elevated and nonelevated PTSD symptoms. Three high-value stressors were identified that best explained the variance in PTSD severity scores and provided acceptable accuracy in classifying youth by elevated versus nonelevated PTSD status: fear of dying, fights, or violence in the home or neighborhood and difficulties accessing food or water. Hurricane-related stressors explained 20.1% of variance in PTSD severity scores and accurately classified 77.6% of youth with elevated PTSD, with the relative importance of stressors varying between outcomes. Implications for triaging care for comprehensive trauma treatment, policies affecting disaster response efforts, and directions for future natural disaster research are discussed. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Investigating stress, anxiety, and coping strategies among higher education students in extreme contexts: insights from Romania during the COVID-19 pandemic

BackgroundUsing the perspective of the recent COVID-19 pandemic, which represents a public health challenge that also affects education and the psychological well-being of students, this paper aims to assess the vulnerability to anxiety and stress of the Romanian students from the Faculty of Administration and Business of the University of Bucharest pursuing their degrees in administration and business.MethodsOur study is based on the results of the survey that was administered to a sample of 422 students (39.6% females and 60.4% males) selected from the pool of 2000 recruited respondents. We employed the ANOVA/linear Dependent Dirichlet Process mixture model to explain the causes of stress and anxiety after various grouping variables represented by gender, specialisation, as well as labour market status.ResultsOur results revealed that more than 80% of the students in the sample yielded medium and high vulnerability to stress, while 64% of the respondents were affected by severe anxiety (high frequency of psychological, social, and physical problems that were difficult for them to control). The most important stressors were the fear of getting infected and social distancing, while self-control was considered the most effective coping strategy by 62.6% of employed students.ConclusionsThese results allow us to provide practical recommendations for effectively coping with stress and anxiety among students in Romania and beyond and to help stakeholders and policymakers design strategies for strengthening students’ resilience, mental health, and well-being in case of future pandemics or other extreme contexts.

Stereotype Threat at Work: A Meta-Analysis.

Stereotype threat refers to the concern of being judged based on stereotypes about one's social group. This preregistered meta-analysis examines the correlates of stereotype threat in the workplace (k = 61 independent samples, N = 40,134). Results showed that stereotype threat was positively related to exhaustion, identity separation, negative affect, turnover intentions, and behavioral coping, and negatively related to career aspirations, job satisfaction, organizational commitment, job engagement, job performance, positive affect, self-efficacy, and work authenticity. In addition, moderator analyses for constructs represented in at least k = 10 samples in the focal analyses showed that relations did not differ for measures of stereotype threat and stigma consciousness. However, the negative relationships between stereotype threat and career aspirations, job satisfaction, and job engagement were stronger for older employees compared with female employees as the stereotyped group. Overall, the findings suggest that stereotype threat constitutes an important stressor in the workplace.

Holding the Line - Mental Well-Being, Stressors, and Coping in Crisis Supporters.

Background: Crisis supporters can experience numerous stressors in their role that can impact their own mental well-being. The area remains underexplored in research, particularly relating to substance use, and new trends in the role such as working remotely or the impact of providing chat-based support. Aims: This study identifies crisis support-related stressors, as well as levels of mental well-being and substance use, and factors associated with mental well-being. Method: Participants (n = 422) were recruited from four leading crisis support services and via social media advertising. They responded to an online survey, assessing demographics, stressors, mental well-being (compassion fatigue, compassion satisfaction, and psychological distress), substance use, and coping styles. Results: Findings identified several important stressors (e.g., argumentative callers) and moderate to high rates of compassion fatigue and psychological distress. High levels of compassion satisfaction were reported, and levels of risky substance use were low. Problem-focused coping emerged as a key factor related to positive mental well-being, while emotion-focused, avoidant coping, remote work, and providing chat-based support were linked to negative well-being. Limitations: The study's cross-sectional design and convenience sample limit causal inferences and generalizability. Conclusion: The findings reveal significant stressors and challenges in crisis supporters that require consideration and intervention.

Integrating RNA-seq and population genomics to elucidate salt tolerance mechanisms in flax (Linum usitatissimum L.).

Salinity is an important abiotic environmental stressor threatening agricultural productivity worldwide. Flax, an economically important crop, exhibits varying degrees of adaptability to salt stress among different cultivars. However, the specific molecular mechanisms underlying these differences in adaptation have remained unclear. The objective of this study was to identify candidate genes associated with salt tolerance in flax using RNA-Seq combined with population-level analysis. To begin with, three representative cultivars were selected from a population of 200 flax germplasm and assessed their physiological and transcriptomic responses to salt stress. The cultivar C121 exhibited superior osmoregulation, antioxidant capacity, and growth under salt stress compared to the other two cultivars. Through transcriptome sequencing, a total of 7,459 differentially expressed genes associated with salt stress were identified, which were mainly enriched in pathways related to response to toxic substances, metal ion transport, and phenylpropanoid biosynthesis. Furthermore, genotyping of the 7,459 differentially expressed genes and correlating them with the phenotypic data on survival rates under salt stress allowed the identification of 17 salt-related candidate genes. Notably, the nucleotide diversity of nine of the candidate genes was significantly higher in the oil flax subgroup than in the fiber flax subgroup. These results enhance the fundamental understanding of salt tolerance mechanisms in flax, provide a basis for a more in-depth exploration of its adaptive responses to salt stress, and facilitate the scientific selection and breeding of salt-tolerant varieties.

Artificial Light at Night Advances the Onset of Vocal Activity in Both Male and Female Great Tits During the Breeding Season, While Noise Pollution Has Less Impact and Only in Females.

Artificial light at night (ALAN) and noise pollution are two important stressors associated with urbanisation that can have a profound impact on animal behaviour and physiology, potentially disrupting biological rhythms. Although the influence of ALAN and noise pollution on daily activity patterns of songbirds has been clearly demonstrated, studies often focus on males, and the few that examined females have not included the potential influence of males on female activity patterns. Using free-living pairs of great tits (Parus major) as a model, we examined for the first time the effects of ALAN and noise pollution and their interaction on the onset of (vocal) activity in both members of a pair. We focused on the egg-laying phase, when both sexes are most vocally active. The onset of male dawn song, female emergence time from the nest box and the onset of female calling in the nest box were measured and used as a proxy for the chronotype. The repeatabilities for all chronotype proxies were high, with higher repeatabilities for males. Consistent with previous studies, ALAN advanced the onset of male dawn song, while it did not elicit a strong response in female emergence time. Additionally, our results suggest an indirect effect of ALAN on the onset of female vocal activity via acoustic interaction with the male. Noise pollution advanced the emergence time in females, while an interaction between ALAN and noise pollution was found for the onset of female calling. In agreement with previous studies, several covariables were shown to have an influence on the activity onset. Taking several proxies for chronotype into account, this study has provided robust evidence of effects of ALAN on male and female cavity-nesting songbirds during the egg-laying period.

Effects of inorganic nitrogen enrichment on soil CH4 and CO2 production in freshwater and mesohaline marshes across six estuaries in China

Eutrophication is an important environmental stressor in coastal wetlands that alters ecosystem processes including primary production and the carbon cycle. However, how different nitrogen eutrophication scenarios may affect CH4 and CO2 production along a salinity gradient in coastal wetlands is poorly known. We collected the surface soil samples from both tidal freshwater and mesohaline Phragmites australis marshes in six main estuaries in China and conducted inorganic nitrogen enrichment anaerobic incubation experiments. Background soil CH4 and CO2 production rates were strongly correlated with total nitrogen but not salinity. On average, nitrate enrichment decreased soil CH4 and CO2 production rates by ca. 20 % in freshwater marsh and 16–43 % in mesohaline marshes, whereas ammonium enrichment decreased CO2 production by ca. 26–30 % but had no effect on CH4 production. Salinity was not an important mitigating factor in either eutrophication scenario. In most cases, nitrogen addition decreased the extracellular enzyme activities of β-1,4-glucosidase and cellobiohydrolase, but increased the activity of β-N-acetyl glucosaminidase, phenol oxidase and peroxidase. Nitrate addition decreased the mcrA gene abundance on average by 34–35 % but ammonium addition had insignificant effect. Total nitrogen availability was an important driver of CH4 and CO2 production rates in these tidally influenced coastal wetlands. Our results showed that tidal marshes with salinity < 15 ppt had similar soil CH4 production rates, and increasing inorganic nitrogen eutrophication might lower soil microbial carbon gas production in both tidal freshwater and mesohaline marshes.

Integrating social, climate and environmental changes to confront accelerating global aging

IntroductionThe global increase in the aging population presents critical challenges for healthcare systems, social security, and economic stability worldwide. Although the studies of the global rate of aging have increased more than four times in the past two decades, few studies have integrated the potential combined effects of socio-economic, climatic, and environmental factors.MethodsWe calculated the geographic heterogeneity of aging population growth rates from 218 countries between 1960 and 2022. Public databases were then integrated to assess the impacts of seven global stressors: socio-economic vulnerability, temperature, drought, seasonality, climate extremes, air pollution, and greening vulnerability on growth rates of aging population (a totally 156 countries). Linear regression models were primarily used to test the statistically significant effects of these stressors on the rate of aging, and multiple model inference was then used to test whether the number of stressors exceeding specific thresholds (e.g., > 25, 50, and 75%) was consistently significant in the best models. The importance of stressors and the number of stressors exceeding thresholds was verified using random forest models for countries experiencing different population aging rates.ResultsOur analysis identified significant heterogeneity in growth rates of aging population globally, with many African countries exhibiting significantly lower aging rates compared with Europe. High socio-economic vulnerability, increased climate risks (such as high temperature and intensive extreme climate), and decreased environmental quality were found to significantly increase growth rates of the aging population (P < 0.05). The positive combined impacts of these stressors were diminished at medium–high levels of stressors (i.e., relative to their maximum levels observed in nature). The number of global stressors exceeding the 25% threshold emerged as an important predictor of global aging rates. Demographic changes in regions with relatively rapid aging (e.g., Africa and Asia) are more sensitive to climate change (e.g., extreme climate and drought) and the number of global stressors, and regions with low to medium rates of aging (e.g., Europe and the Americas) are more sensitive to socio-economic vulnerability and environmental stability (e.g., drought, green fragility and air pollution).ConclusionsOur findings underscore that policy tools or methods must be developed that consider the holistic dimension of the global factor. Further investigations are essential to understand the complex interactions between multiple stressors and their combined effects on global aging.

Enrollment to exams: Perceived stress dynamics among first-year physics students

The current dropout rate in physics studies in Germany is about 60%, with the majority of dropouts occurring in the first year. Consequently, the physics study entry phase poses a significant challenge for many students. Students’ stress perceptions can provide more profound insights into the processes and challenges during that period. In a panel study featuring 67 measuring points involving up to 128 participants at each point, we investigated students’ stress perceptions with the perceived stress questionnaire (PSQ), identified underlying sources of stress, and assessed self-estimated workloads across two different cohorts. This examination occurred almost every week during the first semester, and for one cohort also in the second semester, yielding a total of 3241 PSQ data points and 5823 stressors. The PSQ data indicate a consistent stress trajectory across all three groups studied that is characterized by significant dynamics between measuring points, spanning from M=20.1,SD=15.9 to M=63.6,SD=13.4 on a scale from 0 to 100. Stress levels rise in the first weeks of the lecture, followed by stable, elevated stress levels until the exams and a relaxation phase afterward during the lecture-free time and Christmas vacation. In the first half of the lecture period, students primarily indicated the weekly exercise sheets, the physics lab course, and math courses as stressors; later on, preparation for exams and the exams themselves emerged as the most important stressors. Together with the students’ self-estimated workloads that correlate with the PSQ scores, we can create a coherent picture of stress perceptions among first-year physics students, which builds the basis for supportive measures and interventions. Published by the American Physical Society 2024

Local cryptic diversity in salinity adaptation mechanisms in the wild outcrossing Brassica fruticulosa

It is normally supposed that populations of the same species should evolve shared mechanisms of adaptation to common stressors due to evolutionary constraint. Here, we describe a system of within-species local adaptation to coastal habitats, Brassica fruticulosa, and detail surprising strategic variability in adaptive responses to high salinity. These different adaptive responses in neighboring populations are evidenced by transcriptomes, diverse physiological outputs, and distinct genomic selective landscapes. In response to high salinity Northern Catalonian populations restrict root-to-shoot Na+ transport, favoring K+ uptake. Contrastingly, Central Catalonian populations accumulate Na+ in leaves and compensate for the osmotic imbalance with compatible solutes such as proline. Despite contrasting responses, both metapopulations were salinity tolerant relative to all inland accessions. To characterize the genomic basis of these divergent adaptive strategies in an otherwise non-saline-tolerant species, we generate a long-read-based genome and population sequencing of 18 populations (nine inland, nine coastal) across the B. fruticulosa species range. Results of genomic and transcriptomic approaches support the physiological observations of distinct underlying mechanisms of adaptation to high salinity and reveal potential genetic targets of these two very recently evolved salinity adaptations. We therefore provide a model of within-species salinity adaptation and reveal cryptic variation in neighboring plant populations in the mechanisms of adaptation to an important natural stressor highly relevant to agriculture.

Parental Preferences and Shared Decision-Making for the Management of Febrile Young Infants.

To inform shared decision-making by identifying parental preferences for the management of their febrile young infant. This was a sequential explanatory mixed-methods study using a cross-sectional questionnaire (May 2020-May 2022) followed by qualitative focus groups (September-December 2022) with parents of infants aged ≤60 days evaluated for fever at a tertiary pediatric hospital. Parental expectations, stressors, and desired level of decisional involvement were assessed using multiple-choice and 6-point-Likert scales. Questionnaire results informed the qualitative naturalistic inquiry into parents' decision-making experiences and preferences regarding the need for lumbar puncture (LP) and hospitalization. Among 432 parents (64.9% response), few anticipated the need for LP (10.2%) or hospitalization (20.8%), and these were selected as the most stressful aspects of management. No parent identified lack of decisional involvement as the most important stressor, although nearly all (97.5%) wanted to be involved in management decisions. Six focus groups with a subset of 17 parents revealed 4 main themes: (1) varying preferences for decisional involvement depending on the strength of the medical recommendation; (2) importance of involving parents in their infant's medical care; (3) need for tailored information; and (4) importance of supportive relationships. Parents reported feeling involved in discussions about their infant's care but that decisions regarding LP and hospitalization were usually made by the medical team. Parents of febrile young infants identified LP and hospitalization as the most unexpected and stressful aspects of care. Understanding individual family expectations and tailoring information based on the strength of medical recommendation is necessary to guide shared decision-making.

Microplastic Leachate Negatively Affects Fertilization in the Coral Montipora capitata.

Microplastic pollution is an emerging stressor of concern to coral reef ecosystems, which are already threatened by additional global and local level anthropogenic stressors. The effects of ingesting microplastics alone on corals have been well studied, but the effects of the chemical composition of these particles have been understudied. Many microplastic-associated chemicals are endocrine disrupters potentially posing a threat to organismal reproduction. Therefore, the goal of this study was to determine if differences exist between the effects of microplastics themselves and microplastic leachate on Montipora capitata fertilization due to changes in fatty acid quantity and composition. Assays were conducted two years in a row which exposed M. capitata gamete bundles to either one of four types of recently manufactured, virgin microspheres (nylon, polypropylene, high-density polyethylene, or low-density polyethylene) at three concentrations (50, 100, or 200 particles/L) or microplastic leachates, presumably including plastic additives from these microspheres. Gamete fertilization was not impacted by microplastic particles themselves, but some of the microplastic leachate treatments with the same polymer type significantly reduced fertilization rates for M. capitata. Additionally, a total of 17 fatty acids were seen in both years, but neither fatty acid quantity nor composition correlated with observed declines in fertilization. Instead, fertilization and fatty acid data independently varied by concentration and polymer type, likely due to the presence of different chemicals. This study is the first to directly test the toxicity of microplastic leachate to coral reproduction. These findings show that microplastic-associated chemicals are an important stressor affecting successful coral fertilization and fatty acid quantity and composition and provide evidence for the negative effects of microplastic leachate to coral reproduction. Thus, plastic additives could pose an additional threat to coral replenishment and persistence in coral reef ecosystems.

The effect of neurotransmitters on the course of functional gastrointestinal disorders associated with emotional volitional disturbances caused by stress in children

Background. The medico-social significance of functional gastrointestinal disorders (FGID) in children is due to their prevalence and impact on the quality of life of patients. According to the biopsychosocial model, FGID are heterogeneous diseases that arise as a result of a complex interaction of biological, psychoemotional, and psychosocial factors. Objective: based on the gene­ralization of available literature data, to highlight the influence of serotonin and melatonin neurotransmitters on the course of FGIR associated with emotional volitional disturbances caused by stress in children. Materials and methods. Modern domestic and international scientific literature on the influence of serotonin and melatonin on the course of FGIR associated with emotional volitional disturbances caused by stress in children was reviewed and analyzed. To search for literary sources, the Scopus, PubMed, ResearchGate, Wiley Online Library, and Google Scholar databases were studied for 2016–2024, a total of 98 sources. Results. Modern etiopathogenetic factors for the occurrence of FGIR in children are described, with the key components of their biopsychosocial model highligh­ted. The influence of stressors on the development of mental disorders in children with FGIR, in particular emotional and volitional changes, is considered. We have demonstrated the role of serotonin and melatonin in the regulation of mood, emotions, sleep, beha­vior, anxiety, depression, etc. The importance of these neurotransmitters in the occurrence of gastrointestinal symptoms in FGIR is highlighted with modern approaches to the management of children with FGIR associated with emotional volitional disturbances caused by stress being considered. A promising therapeutic direction is identified — the use of supplements of certain neurotransmitters (in particular, serotonin and melatonin) in children with this pathology. Conclusions. The analyzed literature data demonstrate the heterogeneity of FGIR in children and the importance of stressors in their development. Neurotransmitters play a significant role in the formation of the response to stress and the course of FGIR associated with emotional volitional disturbances caused by stress in children. Data on the effectiveness of serotonin and melatonin supplementation in children with FGIR are few, so there is a need for further research on this issue in order to improve the effectiveness of treatment and the quality of life of these patients.

Challenges and Opportunities in the Sustainable Improvement of Carrot Production.

From an agricultural perspective, carrots are a significant tap root vegetable crop in the Apiaceae family because of their nutritional value, health advantages, and economic importance. The edible part of a carrot, known as the storage root, contains various beneficial compounds, such as carotenoids, anthocyanins, dietary fiber, vitamins, and other nutrients. It has a crucial role in human nutrition as a significant vegetable and raw material in the nutraceutical, food, and pharmaceutical industries. The cultivation of carrot fields is susceptible to a wide range of biotic and abiotic hazards, which can significantly damage the plants' health and decrease yield and quality. Scientific research mostly focuses on important biotic stressors, including pests, such as nematodes and carrot flies, as well as diseases, such as cavity spots, crown or cottony rot, black rot, and leaf blight, caused by bacteria, fungi, and oomycetes. The emerging challenges in the field include gaining a comprehensive understanding of the interaction between hosts and pathogens in the carrot-pathogen system, identifying the elements that contribute to disease development, expanding knowledge of systemic treatments, exploring host resistance mechanisms, developing integrated control programs, and enhancing resistance through breeding approaches. In fact, the primary carrot-growing regions in tropical and subtropical climates are experiencing abiotic pressures, such as drought, salinity, and heat stress, which limit carrot production. This review provides an extensive, up-to-date overview of the literature on biotic and abiotic factors for enhanced and sustainable carrot production, considering the use of different technologies for the shelf-life extension of carrots. Therefore, it addresses the current issues in the carrot production chain, opening new perspectives for the exploration of carrots both as a food commodity and as a source of natural compounds.

Stressors for bus commuters and ways of improving bus journeys

Based on the people-environment conceptual framework, this paper measures the level of transport stress experienced by bus commuters and examines its relationship with a wide range of environmental and personal stressors, as well as different stress responses. A total of 28 environmental stressors, 9 personal stressors, 4 time-related stressors and 6 stated stress responses are examined. The data were collected through a large-scale online questionnaire survey among bus commuters of a major franchised bus company in Hong Kong (n = 5,908). A factor analysis and a structural equation model (SEM) are conducted to unveil the interlinkages among bus-related environmental stressors, personal stressors, travel characteristics, perceived transport stress and stated stress responses. Results indicate that bus commuters reported an average stress level of 47.10 out of 100 (SD = 29.50). The average transport stress level is lower than money, work and family stress but higher than relationship stress. Spatially, there are great variations within the city, with notably higher stress levels for some new towns in Northwest New Territories and the central business district during evening commutes. Based on the SEM results, the number of bus transfers (β = 0.05) and travel time (β = 0.06) are strongly associated with transport stress. Poor bus stop environment (β = 0.14), crowding at bus stops and compartments (β = 0.13), hostile attitudes of passengers and drivers (β = 0.08), and unreliable waiting and travel time (β = 0.08) are important environmental stressors. Many of these factors have not been closely examined in previous studies. In relation to health, transport stress is positively associated with negative physical (β = 0.43) and emotional (β = 0.48) responses. Feeling exhausted, irritated and anxiety were the most commonly reported responses to transport stress. To enhance bus commutes, priorities should be given to improving the bus stop environment, reducing crowding throughout the bus journeys, and alleviating road congestion. Overall, the empirical findings from this large-scale study on transport stress can help governments to formulate targeted measures to enhance the quality of public transit services and to support sustainable urban transport.

Effects of improved on-farm crop storage on DNA methylation of mothers and their infants: evidence from a randomized controlled trial in Kenya

BackgroundStress during pregnancy can lead to adverse maternal and infant health outcomes through epigenetic changes in the hypothalamic–pituitary–adrenal axis. Among farmers in low-income countries, one important stressor is food insecurity, which can be reduced using hermetic storage bags. This study aimed to determine, for the first time, whether a hermetic storage bag intervention during pregnancy positively affects maternal and infant DNA methylation of the hypothalamic–pituitary–adrenal axis-related genes FKBP5 and NR3C1. We further analyzed whether anthropometrics, stress, and mental health were associated with DNA methylation.MethodsThis study was part of a larger matched-pair randomized controlled trial focusing on the impact of improved on-farm storage on food security, poverty, and net income of smallholder farming households. A total of N = 149 mothers were recruited by telephone and invited to attend a study appointment at health facilities in Kakamega County, Western Kenya, with their infants in April or May 2021. During the appointment, anthropometric measurements were taken, questionnaires on stress and mental health were administered, and saliva samples were collected. Logistic and multiple linear regression were used to examine the effect of the intervention and related measures on DNA methylation.ResultsMothers in the intervention group showed higher mean NR3C1 methylation levels than those in the control group, corrected for multiple testing. Maternal postpartum body mass index was positively associated with infant NR3C1 CpG3 DNA methylation. The more stressful life events a mother had experienced in the previous 12 months (including during pregnancy), the lower her FKBP5 CpG3 methylation levels.ConclusionsFood insecurity and stressful life events during pregnancy seem to exert significant effects on maternal DNA methylation. While these stressors did not appear to impact infant DNA methylation in the present study, maternal postpartum body mass index was significantly related to infant methylation. These findings suggest that while infants may be protected from excessive maternal glucocorticoids by placental barrier activity, maternal metabolic status is still reflected in their epigenetic make-up.Trial registration This study was part of a larger matched-pair randomized controlled trial on the impact of improved on-farm crop storage on welfare, nutrition, and human health. Registration can be found in the American Economic Association (AEA) RCT Registry, RCT ID: AEARCTR-0005845.

Relative energy and perceived impact of vessel-generated waves in fetch-limited environments

Houser C, Carswell A, Chittle B, Johnson G, Caschera A, Smith A. 2024. Relative energy and perceived impact of vessel-generated waves in fetch-limited environments. Lake Reserv Manag. 40:285–302 Vessel-generated waves (or wakes) are perceived as an important stressor in both marine and freshwater systems, and they are an increasingly important focus of coastal management. Recent studies suggest that wakes account for a significant portion of the total wave energy in fetch-limited environments and in turn have the potential to resuspend sediment, erode shorelines, degrade water quality, damage infrastructure, and disrupt aquatic ecosystems, in addition to being considered a safety hazard and a nuisance. To assess the relative contribution of wakes to the total wave energy, monitoring was completed at 32 sites across 7 fetch-limited lakes in Ontario, Canada between 2020 and 2023. The percent wake energy was inversely related to the average fetch length, with deviations to the relationship dependent on whether the site was open, an embayment or along a narrow section of the lake. A survey of property owners and residents suggests that the perceived impact of wakes also varies with the fetch length. Shoreline erosion and degraded water quality were identified as primary impacts of wakes in lakes with the smallest average fetch, but very few respondents provided direct evidence of boat wake impacts. Most respondents described vessel operation, experience of the vessel operator and conflict over different boating uses as the primary issues associated with wakes. While boat wakes may contribute a significant portion of the wave energy in fetch-limited lakes, further research is required to determine when and where they may represent a physical and ecological stressor rather than being just a nuisance.

Evaluating the time to detect biological effects of ocean acidification and warming: an example using simulations of purple sea urchin settlement

Ocean acidification (OA) and ocean warming driven by climate change are important stressors for marine species and systems, but documenting and detecting their long-term impacts on biological responses outside of laboratory settings are challenging due to natural variability caused by complex processes and interactions. We used settlement of purple sea urchins Strongylocentrotus purpuratus in the Southern California Bight (USA) over 6 yr as an example data set to parameterize a simulation model for exploring the time needed to detect environmental effects on a biological response. A generalized linear model was used to describe an index of urchin settlement as functions of pH, sea surface temperature (SST), sea surface salinity (SSS), and spatio-temporal factors, demonstrating that settlement was negatively associated with pH (i.e. lower settlement at higher pH) and positively associated with SST and SSS. Monte Carlo simulations were developed from this base model under a variety of alternative scenarios to estimate the time to detect: (1) annual trends in pH and SST time series, (2) pH and SST effects on urchin settlement, and (3) annual trends in urchin settlement. Time to detect pH and SST effects was predominantly influenced by the underlying strength of the relationships and the model uncertainty. Time to detect annual trends in settlement was more sensitive to the severity of long-term OA and warming trends, which had cumulative (at times opposing) effects. This study highlights the variable time scales (2-60+ yr) that may be necessary to detect biological responses to OA and ocean warming and the sensitivity to different assumptions of the study system.

Development and validation of a questionnaire, the REST-Q Fire, to identify teamwork-related resources and stressors in firefighting operations.

In the complex work environments of firefighting teams, it is often human error or difficulties in teamwork that lead to dangerous situations. To prevent these, it is essential to know the teamwork-related stressors and resources in firefighting operations. A measurement tool is needed to evaluate these stressors and resources. A successive instrument development process was conducted to identify the relevant teamwork-related stressors and resources in firefighting operations. First, interviews with experienced firefighters, and second, a document analysis were conducted and evaluated to provide an overview of the teamwork-related stressors and resources. Thereupon, a questionnaire, the REST-Q Fire, was developed asking about the experienced frequency and intensity of the identified teamwork-related stressors and resources in firefighting operations. Afterwards, an online study with firefighters was conducted (N = 491). CFAs confirmed the assumed structure of the REST-Q Fire and a positive correlation of the intensity of stressors with stress was shown (r = .19 - .27). Further, the resources were overall more frequently and intensively perceived than the stressors. The most important stressors were 'behavior of leaders' (M (SD)frequency = 2.80 (0.83), M (SD)intensity = 3.59 (1.12)), and 'behavior of team members' (M (SD)frequency = 2.77 (0.75), M (SD)intensity = 3.59 (1.05)). The most important resources, on the other hand, were 'knowledge about skills and behavior of team members' (M (SD)frequency = 3.96 (0.63), M (SD)intensity = 4.24 (0.78)), 'watch out for/ check on each other' (M (SD)frequency = 3.96 (0.70), M (SD)intensity = 4.20 (0.80)), and 'reliability of team members' (M (SD)frequency = 3.96 (0.51), M (SD)intensity = 4.16 (0.73)). As a result, training needs for trainees in the fire service and experienced firefighters were derived.

Effect and mechanism of biochar-based hydrogel to alleviate drought stress in tobacco

Drought is an important abiotic stressor that adversely affects agricultural production, resulting in decreased crop yields and food insecurity. The objective of this study was to develop a novel hydrogel-based composite (S-B-AA) by incorporating biochar into hydrogel (S-AA) and evaluating its effects on tobacco plants under drought stress. The S-B-AA hydrogel exhibited enhanced water absorption and retention capabilities compared to the S-AA hydrogel. Under drought stress conditions, the S-B-AA hydrogel effectively increased the total water content, relative water content, and free water content of tobacco leaves, while reducing the bound water content and water saturation deficit. Additionally, it improved the stomatal status of tobacco leaves, significantly enhanced the photosynthetic capacity of tobacco seedlings, and promoted biomass accumulation. Moreover, the S-B-AA hydrogel alleviated the excessive accumulation of reactive oxygen species (ROS) induced by drought stress in tobacco seedlings, thereby alleviating ROS damage to cell membranes. It also reduced antioxidant enzyme activity and the levels of the signaling molecule H2S, while minimizing the impact of drought stress on tobacco osmotic regulation. Transcriptome analysis revealed that S-B-AA up-regulated 2826 DEGs and down-regulated 5225 DEGs compared to the control group. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis demonstrated that the differentially expressed genes were predominantly enriched in the mitogen-activated protein kinase (MAPK) signaling pathway, plant hormone signaling pathway, and photosynthesis pathway. This study provides a theoretical basis and practical guidance for the application of S-B-AA hydrogel in agriculture and environmental protection.