Large-scale Stressors Research Articles

Assessment of Psychological Distress and Perceived Social Support in the Patients of COVID-Associated Mucormycosis

Abstract Background/ Objective: Coronavirus disease (COVID) 2019-associated mucormycosis is an aggressive fungal infection with an unpredictable outcome and poor prognosis, including a permanent vision loss. It could potentially trigger and amplify mental health problems, and the social support has been known to buffer the negative impact of such a large-scale stressor on mental health. Therefore, the present study aimed to estimate the prevalence and severity of depression, anxiety, and stress with the level of perceived social support and correlation between them in patients with COVID-associated mucormycosis. Materials and Methods: This was a cross-sectional, observational study conducted on 100 patients of mucormycosis at a tertiary care hospital, and the patients were enrolled by a convenience sampling method on the basis of inclusion and exclusion criteria. Depression, anxiety, and Stress Scale-21 items, and Multidimensional Scale of Perceived Social Support with a self-constructed semi-structured pro-forma were used to collect the required data. Results: The prevalence of depression, anxiety, and stress was found to be 49%, 80%, and 56%, respectively. 8.0% perceived low, 65.0% perceived medium, and 27.0% perceived a high social support. No correlation between depression, anxiety, and stress with the perceived social support was found. Conclusions: Our study highlights the burden of psychological issues in mucormycosis patients. Psychiatric implications can be of paramount importance while dealing with pandemics, and therefore, a routine mental health assessment and timely psychological and social interventions can reduce the adverse impact on mental health outcomes.

Exposure to the Indian Ocean Tsunami shapes the HPA-axis resulting in HPA “burnout” 14 years later

Despite significant research on the effects of stress on the hypothalamic-pituitary-adrenal (HPA) axis, questions remain regarding long-term impacts of large-scale stressors. Leveraging data on exposure to an unanticipated major natural disaster, the 2004 Indian Ocean tsunami, we provide causal evidence of its imprint on hair cortisol levels fourteen years later. Data are drawn from the Study of the Tsunami Aftermath and Recovery, a population-representative longitudinal study of tsunami survivors who were living along the coast of Aceh, Indonesia, when the tsunami hit. Annual rounds of data, collected before, the year after and 2 y after the disaster provide detailed information about tsunami exposures and self-reported symptoms of post-traumatic stress. Hair samples collected 14 y after the tsunami from a sample of adult participants provide measures of cortisol levels, integrated over several months. Hair cortisol concentrations are substantially and significantly lower among females who were living, at the time of the tsunami, in communities directly damaged by the tsunami, in comparison with similar females living in other, nearby communities. Differences among males are small and not significant. Cortisol concentrations are lowest among those females living in damaged communities who reported elevated post-traumatic stress symptoms persistently for two years after the tsunami, indicating that the negative effects of exposure were largest for them. Low cortisol is also associated with contemporaneous reports of poor self-rated general and psychosocial health. Taken together, the evidence points to dysregulation in the HPA axis and "burnout" among these females fourteen years after exposure to the disaster.

A gender comparison of psychological distress among medical students in Nigeria during the Coronavirus pandemic: a cross-sectional survey.

The Coronavirus disease (COVID-19) pandemic as a large scale stressor could have negative effects on the mental health of medical students. Since gender differences in mental health may exist, it is important to see if a large scale stressor like the pandemic may be associated with variances in the psychological distress between both genders. To assess and compare the psychological distress of male and female medical students during the COVID-19 pandemic. A cross-sectional survey was carried out among 1010 medical students from three universities in southwestern Nigeria within the first six months of the first reported case of the COVID-19 pandemic. The respondents were purposively selected. Data was obtained online on participants' demographic and psychological distress using the General Health Questionnaire 12 (GHQ-12). Data was analyzed using the SPSS version 21, student t and chi-square tests were used to assess gender differences, and multivariate regression to assess the predictors of psychological distress among both genders. p values less than 0.05were considered statistically significant. Overall, female participants (OR=1.455, 95% CI= 1.095-1.936) were twice more likely to have experienced psychological distress than males during the COVID-19 pandemic. Age (OR=0.922, 95% CI= 0.867-0.979), being in pre-clinical years (OR= 1.394, 95% CI= 1.004-1.938), having a family income less than 100,000 naira (OR= 1.379, 95% CI=1.442-6.723) a previous history of mental illness (OR=3.077, 95% CI= 1.430-6.615) and having a relative/acquaintance diagnosed with COVID 19(OR=1.646, 95% CI= 1.062-2.551) were independently associated with psychological distress among the respondents. When comparing both genders, among females, age (OR=0.886, 95% CI= 0.803-0.978), family income less than 100,000 naira (OR=1.898, 95% CI= 1.306-2.759) and a previous history of mental illness (OR=5.266, 95% CI= 1.894-14.635) were associated with psychological distress, while, being in pre-clinical years (OR= 1.713, 95% CI= 1.052-2.790) was associated with psychological distress among males. Females had more psychological distress compared to male students. It is recommended that gender-specific interventions addressing psychological distress among medical students are instituted.

The Benefits of Living With Close Others: A Longitudinal Examination of Mental Health Before and During a Global Stressor.

For better or worse, the people one lives with may exert a powerful influence on one's mental health, perhaps especially during times of stress. The COVID-19 pandemic-a large-scale stressor that prompted health recommendations to stay home to reduce disease spread-provided a unique context for examining how the people who share one's home may shape one's mental health. A seven-wave longitudinal study assessed mental health month to month before and during the pandemic (February through September 2020) in two diverse samples of U.S. adults (N = 656; N = 544). Preregistered analyses demonstrated that people living with close others (children and/or romantic partners) experienced better well-being before and during the pandemic's first 6 months. These groups also experienced unique increases in ill-being during the pandemic's onset, but parents' ill-being also recovered more quickly. These findings highlight the crucial protective function of close relationships for mental health both generally and amid a pandemic.

A metric-based analysis on the effects of riparian and catchment landuse on macroinvertebrates

Woody riparian vegetation along rivers and streams provides multiple functions beneficial for aquatic macroinvertebrate communities. They retain fine sediments, nutrients and pesticides, improve channel hydromorphology, control water temperature and primary production through shading and provide leaves, twigs and large wood.In a recent conceptual model (Feld et al., 2018), woody riparian functions were considered either independent from large-scale landuse stressors (e.g. shading, input of organic matter), or dependent on landuse at larger spatial scales (e.g. fine sediment, nutrient and pesticide retention).We tested this concept using high-resolution data on woody riparian vegetation cover and empirical data from 1017 macroinvertebrate sampling sites in German lowland and mountain streams. Macroinvertebrate metrics indicative for individual functions were used as response variables in structural equation models (SEM), representing the hierarchical structure between the different considered stressors at different spatial scales: catchment, upstream riparian, local riparian and local landuse cover along with hydromorphology and water quality.The analysis only partly confirmed the conceptual model: Biotic integrity and water quality were strongly related to large-scale stressors as expected (absolute total effect 0.345–0.541), but against expectations, fine sediments retention, considered scale-dependent in the conceptual model, was poorly explained by large-scale stressors (absolute total effect 0.027–0.231). While most functions considered independent from large-scale landuse were partly explained by riparian landuse cover (absolute total effect 0.023–0.091) they also were nonetheless affected by catchment landuse cover (absolute total effect 0.017–0.390).While many empirical case studies at smaller spatial scales clearly document the positive effects of restoring woody riparian vegetation, our results suggest that most effects of riparian landuse cover are possibly superimposed by larger-scale stressors. This does not negate localized effects of woody riparian vegetation but helps contextualize limitations to successful restoration measures targeting the macroinvertebrate community.

САМОСПРИЙНЯТТЯ ЗМІН СПОСОБУ ЖИТТЯ ТА БЛАГОПОЛУЧЧЯ, ЗУМОВЛЕНИХ СОЦІАЛЬНИМ ДИСТАНЦІЮВАННЯМ ПІД ЧАС COVID-19 СЕРЕД СТУДЕНТІВ-МЕДИКІВ (дослідження у Львові, Україна)

Social distancing related to the coronavirus disease (COVID-19) pandemic caused by SARS COV2 is an important precautionary measure, implemented by WHO approximately 1 year ago. At the same time, it is a large-scale stressor that has led to multiple changes in the lifestyle around the world. In this crisis, the well-being and health of medical students who belong to the individuals with a high risk of distress in the population are very important for society. The purpose of this research is to study the impact of COVID-19-related stay-at-home policy, social isolation, online academic learning, and working on the medical students' lifestyle and well-being focusing on their self-perception of telecommunication technologies, social media, as well as on the psychophysiological state, and eating behavior of medical students of Danylo Halytsky Lviv National Medical University (LNMU). Methods. A prospective, cohort study was carried out on 273 medical students of the LNMU via an anonymous online survey using Google Forms. 273 people of different ethnicities answered the original questionnaire, which includes: 1) general questions (age, gender, ethnicity, family, education, work, and economic status); 2) issues related to the use of social media; 3) questions about the impact of social distancing on lifestyle; 4) the scale of stress perception. Results: The cohort for the study consisted of 166 women and 107 men in the following age groups: from 17 to 24 — 92 %, 25–31 — 4 %, 35–44 — 2 %, and over 45 years — 2 %. Ethnic groups included Asian — 47 %, Caucasian — 41 %, African — 7 %, Hispanic — 3 %, and multiracial people — 2 %. Social exclusion during COVID-19 was found to be caused by a change in the use of social media, more time spent on using them by all respondents. Among these, 88 % acknowledge that social media have a great impact and 71 % of responders learn basic information about the pandemic via social media. However, 52 % doubt the reliability of the information. The feeling of anxiety, panic, which characterized the perception of stress caused by information on social media, was reported by 56 % of respondents. Almost all respondents changed their lifestyle, which was characterized by physical inactivity and changed eating behavior. About 60 % of respondents reported overeating in the evening and at night (19:00 — 5:00) and almost half of all respondents reported weight gain in the last year. All respondents know about the benefits of physical activity to overcome signs of psycho-emotional stress, but only about 10 % of respondents exercise regularly. There were no differences in the responses from students belonging to the Caucasian group or other ethnicities. Conclusions. The lifestyle of student youth, their eating behavior, and psycho-emotional state are being modified during COVID-19. Social media is an important informative factor in the context of social exclusion and the fight against chronic stress

Drought effects on invertebrate metapopulation dynamics and quasi-extinction risk in an intermittent river network.

Ecological communities can remain stable in the face of disturbance if their constituent species have different resistance and resilience strategies. In turn, local stability scales up regionally if heterogeneous landscapes maintain spatial asynchrony across discrete populations-but not if large-scale stressors synchronize environmental conditions and biological responses. Here, we hypothesized that droughts could drastically decrease the stability of invertebrate metapopulations both by filtering out poorly adapted species locally, and by synchronizing their dynamics across a river network. We tested this hypothesis via multivariate autoregressive state-space (MARSS) models on spatially replicated, long-term data describing aquatic invertebrate communities and hydrological conditions in a set of temperate, lowland streams subject to seasonal and supraseasonal drying events. This quantitative approach allowed us to assess the influence of local (flow magnitude) and network-scale (hydrological connectivity) drivers on invertebrate long-term trajectories, and to simulate near-future responses to a range of drought scenarios. We found that fluctuations in species abundances were heterogeneous across communities and driven by a combination of hydrological and stochastic drivers. Among metapopulations, increasing extent of dry reaches reduced the abundance of functional groups with low resistance or resilience capacities (i.e. low ability to persist in situ or recolonize from elsewhere, respectively). Our simulations revealed that metapopulation quasi-extinction risk for taxa vulnerable to drought increased exponentially as flowing habitats contracted within the river network, whereas the risk for taxa with resistance and resilience traits remained stable. Our results suggest that drought can be a synchronizing agent in riverscapes, potentially leading to regional quasi-extinction of species with lower resistance and resilience abilities. Better recognition of drought-driven synchronization may increase realism in species extinction forecasts as hydroclimatic extremes continue to intensify worldwide.

The Watershed Architecture of the Mississippi River Basin

Designers have a three-part responsibility owed to their object of study: to appreciate, to speculate, and to collaborate. This is particularly true for the professional engagement with spaces on the scale of river basins which impact and prioritize certain design decisions on a whole different level. Adequate responses to the ongoing transformations brought forward by large-scale anthropogenic stressors across entire river systems cannot continue to be dominated with hardline and static interventions. Rather, there is a need for alternative outsets, one that begins to design with adaptive and dynamic negotiations. By looking at the example of the Mississippi River Basin, this essay proposes a new integrated water-based design methodology titled “Way Beyond Bigness: The Need for a Watershed Architecture,” an interdisciplinary strategy to rethink the management of river systems for a sustainable future.

Temporal trends and determinants of fish biomass in two contrasting natural lake systems: insights from a spring long-term monitoring scheme

Freshwater fish declines are triggered by a suite of anthropogenic threats, including habitat degradation, climate and land use change, biological invasions, pollution and overfishing. Robust monitoring schemes are needed to understand and detect any effects of different factors on freshwater fish abundance and to be able to predict and respond to potential stressors. Here, we used standardized biomass-per-unit-effort (BPUE) data deriving from gillnet sampling over a 34-year period in the two Prespa Lakes and determined species trends using general additive models coupled with structural change models. Furthermore, the influence of seven environmental variables was assessed for each fish species using an analytical approach based on random forests. We showed that the total annual BPUE is increasing in Lake Mikri Prespa whereas it is stable in Megali Prespa and that the relative BPUE of introduced species in the former is increasing through the years. Differences in the lakes' trophic status were reflected in species trend patterns. Random forests showed that air temperature, the introduction of the invasiveLepomis gibbosus, predation and water management played a role in shaping species biomass in Mikri Prespa whereas abiotic factors are the main drivers of biomass changes in Megali Prespa. Our results provide empirical evidence on the importance of long-term monitoring in distinguishing between direct and indirect effects of large-scale stressors on fish abundance as well as insights towards sustaining the integrity of fish communities.

Relations of COVID-19-Related Stressors and Social Support With Chinese College Students' Psychological Response During the COVID-19 Pandemic.

This study examines the main and interactive relations of stressors and social support with Chinese college students' psychological symptoms (e.g., anxiety, depression) during the COVID-19 pandemic. All the constructs are assessed by self-report in an anonymous survey during the pandemic outbreak. The results show that the number of stressors has a positive relation with psychological symptoms, and social support has a negative relation with psychological symptoms. In addition, social support serves as a buffer against the negative impact of stressors. These findings hold implications for university counseling services during times of acute, large-scale stressors. Specifically, effective screening procedures should be developed to identify students who experience large number of stressors and provide suitable psychological intervention for them.

Kelp forests

Vergés and Campbell introduce the kelp forest ecosystem.

Online Mental Health Survey in a Medical College in China During the COVID-19 Outbreak.

BackgroundThe outbreak of coronavirus disease 2019 (COVID-19) in Wuhan, Hubei province, has led to the quarantine of many residents in their homes, in order to mitigate its spread. Some of these people developed mental health problems, and many solutions have been put in place to address the mental health issues of patients and health professionals affected by the disease. However, not much attention has been given to students, particularly those from medical school. The present study aims to conduct an online survey to investigate the mental health status of students from a medical college in Hubei province.Materials and MethodsThe WeChat-based survey program Questionnaire Star, which contained questions from Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), was utilized for the present study.ResultsA total of 217 students participated in the survey. Among these students, 127 were female and 90 were male. Furthermore, 77 students (35.5%) who participated in the survey were in a state of depression, and 48 (22.1%) were in a state of anxiety. The majority of students who were in depressed (n=75) or anxiety (n=46) states had mild or moderate states. There were no significant differences in students in terms of gender, geographical location, and grade, for the prevalence of depression and anxiety.ConclusionThe present study implies that universities need to take measures to prevent, identify, and deal with mental health problems among students during large-scale stressors.

Regional versus local drivers of water quality in the Windermere catchment, Lake District, United Kingdom: The dominant influence of wastewater pollution over the past 200years.

Freshwater ecosystems are threatened by multiple anthropogenic stressors acting over different spatial and temporal scales, resulting in toxic algal blooms, reduced water quality and hypoxia. However, while catchment characteristics act as a 'filter' modifying lake response to disturbance, little is known of the relative importance of different drivers and possible differentiation in the response of upland remote lakes in comparison to lowland, impacted lakes. Moreover, many studies have focussed on single lakes rather than looking at responses across a set of individual, yet connected lake basins. Here we used sedimentary algal pigments as an index of changes in primary producer assemblages over the last ~200years in a northern temperate watershed consisting of 11 upland and lowland lakes within the Lake District, United Kingdom, to test our hypotheses about landscape drivers. Specifically, we expected that the magnitude of change in phototrophic assemblages would be greatest in lowland rather than upland lakes due to more intensive human activities in the watersheds of the former (agriculture, urbanization). Regional parameters, such as climate dynamics, would be the predominant factors regulating lake primary producers in remote upland lakes and thus, synchronize the dynamic of primary producer assemblages in these basins. We found broad support for the hypotheses pertaining to lowland sites as wastewater treatment was the main predictor of changes to primary producer assemblages in lowland lakes. In contrast, upland headwaters responded weakly to variation in atmospheric temperature, and dynamics in primary producers across upland lakes were asynchronous. Collectively, these findings show that nutrient inputs from point sources overwhelm climatic controls of algae and nuisance cyanobacteria, but highlights that large-scale stressors do not always initiate coherent regional lake response. Furthermore, a lake's position in its landscape, its connectivity and proximity to point nutrients are important determinants of changes in production and composition of phototrophic assemblages.

Effect of stress on cardiometabolic health 12 years after the Indian Ocean tsunami: a quasi-experimental longitudinal study

BackgroundStress is associated with elevated cardiometabolic health risks, but establishing a causal mechanism is challenging, and evidence of the longer-term effects of large-scale stressors on health is limited. To fill these gaps, we investigated the effect of elevated stress from direct exposure to the 2004 Indian Ocean tsunami on diabetes risk 12 years later. The Indian Ocean tsunami destroyed the built and natural environment along coastal Aceh, Indonesia, killed 5% of the population, and caused very high levels of post-traumatic stress among those who were exposed. MethodsIn a quasi-experimental research design, we focused on respondents who were living, at the time of the tsunami, in districts that had a vulnerable coastline in Aceh, Indonesia. Using unique, population-representative, longitudinal survey data collected before and after the tsunami (the Study of the Tsunami Aftermath and Recovery), we compared diabetes incidence in adults directly exposed to the trauma of the tsunami with diabetes incidence in adults not directly exposed. Specifically, adults who were living, at the time of the tsunami, in communities that were heavily damaged were compared with those living in other communities in the same districts that were not damaged. We collected biomarker data 12 years after the tsunami, including levels of glycated haemoglobin (HbA1c), from respondents who were still living in a randomly selected sample of baseline communities, as well as from baseline respondents who had moved elsewhere. FindingsOf 4538 respondents aged 20–65 years for whom biomarker data were collected, 6·7% were diabetic (HbA1c ≥6·5%) and, of the 1882 respondents aged 40–65 years, 12·2% were diabetic. Among men in this older age group, when controlling for age, those who were living in heavily damaged communities at the time of the tsunami were 6 percentage points more likely to be diabetic than those who were living in communities that were not damaged (p=0·008). There was no evidence of elevated diabetes incidence among younger men or among women living in heavily damaged communities: the difference between the exposed and unexposed groups was small (–0·3 percentage points) and not significant (p=0·77) for these respondents InterpretationExposure to mortality and destruction at the community level is unlikely to explain these differences in diabetes incidence among the exposed and unexposed by age group and sex. It is likely that the loss of livelihood took a greater toll on the cardiometabolic health of older men, who faced greater difficulty rebuilding their wealth later in the life course than did younger men and women of all ages. The results suggest an important economic pathway by which stress-related exposures can affect cardiometabolic health. FundingWellcome Trust (OPOH 106853/A/15/Z), the National Institute on Aging (R01 AG031266), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01 HD052762), the National Science Foundation (CMS-0527763), and the World Bank.

Calcium decline reduces population growth rates of zooplankton in field mesocosms

Regional calcium (Ca) decline, a legacy of acid deposition and logging, is a potential threat to aquatic organisms. Lake surveys and laboratory studies indicate that Ca-rich daphniids are likely most susceptible, allowing for competitive release of other taxa with low Ca demand. Indeed, dramatic shifts in zooplankton community structure have been documented in lakes where Ca has declined, amid multiple other stressors. Given the perceived threat of this large-scale stressor, manipulative studies are needed to evaluate causal relationships between Ca decline and zooplankton community structure. We analysed per capita growth rates of zooplankton from three independent mesocosm experiments where we manipulated aqueous Ca concentrations to reflect current and future Ca concentrations. In two experiments where Ca concentration was reduced to 0.6 or 0.9 mg/L, we observed reduced growth rates for several taxa, including daphniids, bosminids, and copepods. No effect of Ca was detected in the experiment where Ca concentrations ranged from 1.2 to 2.5 mg/L, a gradient representing 68% of lakes in south-central Ontario. These results suggest that future Ca decline in soft-water Canadian Shield lakes may be accompanied by shifts in community structure and overall declines in zooplankton production.

The Role of Daily Hassles and Distress Tolerance in Predicting Cigarette Craving During a Quit Attempt

Ecological momentary assessment (EMA) has shown that smoking behavior is linked to transient variables in the smoker's immediate context. Such research suggests that daily hassles (e.g., losing one's keys) may be more likely to lead to cigarette craving and eventual lapse than infrequent, large-scale stressors (e.g., death of a loved one) among individuals attempting to quit smoking. However, individual differences in distress tolerance (DT) may moderate the relationship between daily hassles and daily cigarette craving during a quit attempt. A sample of 56 veterans and community members drawn from a larger smoking-cessation study completed structured interviews and paper-and-pencil questionnaires during an initial laboratory visit and, directly following a quit attempt, were monitored via EMA. Multilevel modeling was used to examine the relationship between daily hassles and daily cigarette craving and to determine whether DT moderated this relationship. Daily hassles were positively associated with daily cigarette craving, and this association was moderated by individual differences in DT, such that the lower one's DT, the stronger the relationship between daily hassles and daily cigarette craving. This model explained 13% of the intraindividual variability and 8% of the interindividual variability in daily cigarette craving. Smoking-cessation interventions may be strengthened by targeting smokers' individual responses to contextual factors, such as by helping smokers develop skills to cope more effectively with distress prior to and during the quit phase.

Reach-scale channel sensitivity to multiple human activities and natural events: Lower Santa Clara River, California, USA

Understanding the cumulative impact of natural and human influences on the sensitivity of channel morphodynamics, a relative measure between the drivers for change and the magnitude of channel response, requires an approach that accommodates spatial and temporal variability in the suite of primary stressors. Multiple historical data sources were assembled to provide a reach-scale analysis of the lower Santa Clara River (LSCR) in Ventura County, California, USA. Sediment supply is naturally high due to tectonic activity, earthquake-generated landslides, wildfires, and high magnitude flow events during El Niño years. Somewhat typically for the region, the catchment has been subject to four reasonably distinct land use and resource management combinations since European-American settlement. When combined with analysis of channel morphological response (quantifiable since ca. 1930), reach-scale and temporal differences in channel sensitivity become apparent. Downstream reaches have incised on average 2.4m and become narrower by almost 50% with changes focused in a period of highly sensitive response after about 1950 followed by forced insensitivity caused by structural flood embankments and a significant grade control structure. In contrast, the middle reaches have been responsive but are morphologically resilient, and the upstream reaches show a mildly sensitive aggradational trend. Superimposing the natural and human drivers for change reveals that large scale stressors (related to ranching and irrigation) have been replaced over time by a suite of stressors operating at multiple spatial scales. Lower reaches have been sensitive primarily to ‘local’ scale impacts (urban growth, flood control, and aggregate mining) whereas, upstream, catchment-scale influences still prevail (including flow regulation and climate-driven sediment supply factors). These factors illustrate the complexity inherent to cumulative impact assessment in fluvial systems, provide evidence for a distinct Anthropocene fluvial response, and underpin the enormity of the challenge faced in trying to sustainably manage and restore rivers.

Effects of fishing, market price, and climate on two South American clam species

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 469:71-85 (2012) - DOI: https://doi.org/10.3354/meps10016 Effects of fishing, market price, and climate on two South American clam species Leonardo Ortega1, Juan Carlos Castilla2, Marco Espino3, Carmen Yamashiro3, Omar Defeo1,4,* 1Dirección Nacional de Recursos Acuáticos (DINARA), Constituyente 1497, 11200 Montevideo, Uruguay 2Departamento de Ecología, Facultad de Ciencias Biológicas and Centro Interdisciplinario de Cambio Global, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile 3Instituto del Mar del Perú, Apartado 22, Callao, Perú 4Unidad de Ciencias del Mar (UNDECIMAR), Facultad de Ciencias, Iguá 4225, 11400 Montevideo, Uruguay *Corresponding author. Email: odefeo@dinara.gub.uy ABSTRACT: Coastal shellfish are being threatened by several drivers acting at multiple temporal and spatial scales, including fishing, climate, and globalization of markets. We evaluated large-scale and long-term combined effects of fishing, climate, and economic variables on 2 congeneric clams that inhabit sandy beaches of the Pacific (Mesodesma donacium) and the Atlantic (M. mactroides) in South America. Bioeconomic and climatic variables, such as coastal sea surface temperature anomalies (SSTA) and broad-scale climatic indices (Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation), were related to variations in clam populations in a differential way according to latitude and oceanographic features. For M. donacium, the nature and sign of the relationships between landings and explanatory predictors markedly differed between bioclimatic units. El Niño Southern Oscillation events negatively affected landings in Peru and northern Chile, whereas landings increased in southern Chile and showed a positive correlation with increasing SSTA, suggesting a positive effect at the southernmost edge of the species distribution. Long-term trends in the abundance of M. mactroides were related to fishing intensity and SSTA. As anticipated by basic economic theory, deficit of supply relative to demand, exacerbated by very low harvesting costs, pushed the price up and has driven these clam species to levels close to extinction (anthropogenic Allee effect). The lack of response of the stocks to long-term closures suggests that these systems exceeded critical thresholds (tipping points). Information on early warnings of tipping points is needed to help manage coastal shellfisheries that are increasingly threatened by long-lasting and large-scale stressors. KEY WORDS: Intertidal clams · Sandy beaches · Climate variability · Fisheries bioeconomics Full text in pdf format Supplementary material PreviousNextCite this article as: Ortega L, Castilla JC, Espino M, Yamashiro C, Defeo O (2012) Effects of fishing, market price, and climate on two South American clam species. Mar Ecol Prog Ser 469:71-85. https://doi.org/10.3354/meps10016 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 469. Online publication date: November 26, 2012 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2012 Inter-Research.

Relations of SARS-related stressors and coping to Chinese college students' psychological adjustment during the 2003 Beijing SARS epidemic.

This study examined the main and interactive relations of stressors and coping related to severe acute respiratory syndrome (SARS) with Chinese college students' psychological adjustment (psychological symptoms, perceived general health, and life satisfaction) during the 2003 Beijing SARS epidemic. All the constructs were assessed by self-report in an anonymous survey during the final period of the outbreak. Results showed that the relations of stressors and coping to psychological adjustment varied by domain of adjustment. Regression analyses suggested that the number of stressors and use of avoidant coping strategies positively predicted psychological symptoms. Active coping positively predicted life satisfaction when controlling for stressors. Moreover, all types of coping served as a buffer against the negative impact of stressors on perceived general health. These findings hold implications for university counseling services during times of acute, large-scale stressors. In particular, effective screening procedures should be developed to identify students who experience a large number of stressors and thus are at high risk for developing mental health problems. Intervention efforts that target coping should be adapted to take account of the uncontrollability of stressors and clients' cultural preferences for certain coping strategies. A multidimensional battery of psychological adjustment should be used to monitor clients' psychological adjustment to stressors and evaluate the efficacy of intervention.

Characterization of biological responses under different environmental conditions: A hierarchical modeling approach

A natural river system is organized as a nested hierarchy of interconnected habitats with specific environmental conditions to which the biological community has adapted. Due to this hierarchical structure, identifying the role of different stressors on the biological community is a formidable task. Efforts trying to link stressors to biological integrity have always been bound to the geographic scale of the selected study area, leading to scale-specific results. In this research, an attempt is made to lift this limitation and develop a hierarchical, scale-sensitive methodology that can identify the significant environmental stressors to the biological community at different scales. Sites with similar background environmental conditions are clustered using self-organizing maps (SOM). This is used to identify stressors which affect the biological community throughout the area of study – called environmental gradients or large-scale stressors. Subsequently, these clusters of similar observations (sampling sites) are progressively sub-divided using environmental variables with a significant but localized effect on the biological community – called small-scale stressors. A parent group of sites is split only when the resulting sub-groups have significantly different biological responses. At the end of this recursive sites decomposition procedure, the original set of observations is organized as a tree of environmentally homogeneous groups of observations characterized by unique biological responses to multiple stressors with different geographic extents. The developed hierarchical analysis methodology has been validated using a large-size dataset of environmental observations from the State of Ohio. Our results show that habitat degradation and increased nutrient loading are the large-scale stressors with a widespread impact in Ohio. Other stressors, such as heavy metals, pH or nitrate concentrations have significant albeit localized effects on biological integrity.