Levels Of Environmental Stress Research Articles

Summer aridity rather than management shapes fitness-related functional traits of the threatened mountain plant Arnica montana.

Semi‐natural mountain grasslands are increasingly exposed to environmental stress under climate change. However, which are the environmental factors that limit plants in these grasslands? Also, is the present management effective against these changes? Fitness‐related functional traits may offer a way to detect changes in performance and provide new insights into their vulnerability to climate change. We investigated changes in performance and variability of functional traits of the mountain grassland target species Arnica montana along a climate gradient in Central German low mountain ranges. This gradient represents at its lower end climate conditions that are expected at its upper end under future climate change. We measured vegetative, generative, and physiological traits to account for multiple ways of plant responses to the environment. Using mixed effects and multivariate models, we evaluated changes in trait values among individuals as well as the variability of their populations in order to assess performance under changing summer aridity and different management regimes. Fitness‐related performance of most traits showed strongly positive associations with reduced summer aridity at higher elevations, while only specific leaf area and leaf dry matter content showed no association. This suggests a higher performance level at less arid montane sites and that the physiological traits are less sensitive to this climate change factor. The coefficient of variation of almost all traits declined steadily with decreasing site aridity. We suggest that this reduced variability indicates a lower environmental stress level for A. montana toward its environmental optimum at montane elevations, especially because the trait performance increased simultaneously. Surprisingly, management factors and habitat characteristics had only low influence on both trait performance and variability. In summary, summer aridity had a stronger effect to shape the trait performance and variability of A. montana under increased environmental stress than management and other habitat characteristics.

Effects of functional diversity and salinization on zooplankton productivity: an experimental approach

Quantifying the interactions between functional diversity and environmental change is important for understanding the effects of biodiversity on ecosystem processes. This study aims to evaluate zooplankton secondary production and biomass in an experiment with different levels of functional diversity and environmental stress in the form of increased salinity. It is expected that communities that are more functionally diverse will present higher secondary production and biomass, even under conditions of environmental stress. To test this hypothesis, a mesocosm experiment with two factors was performed: low and high diversity and with and without salt totaling four possible combinations of treatments over the duration of 4 weeks. The high functional diversity treatments showed higher zooplankton secondary production and biomass than those of the low diversity treatments, even under salt addition. The salinity decreased zooplankton production and functional diversity, but its effects were more pronounced in the low than in the high diversity communities. However, in the low diversity treatments the zooplankton biomass and production were maintained due to the dominance of species with certain traits. In summary, our study contributed to understanding the role of zooplankton functional diversity on ecosystem processes in the face of environmental changes promoted by increased salinity.

Inducible versus constitutive antioxidant defenses in algae along an environmental stress gradient

Optimal defense theory (ODT) predicts that antiherbivore defenses should be constitutive when plants are frequently attacked and inducible when the probability of attack is low. Like antiherbivore defenses, antioxidant defenses can be inducible or constitutive. We hypothesized the ODT predictions should apply to antioxidant defenses; thus, species inhabiting environments where oxidative stresses occur frequently should produce constitutive antioxidant defenses, whereas species in environments where stresses occur less frequently should produce inducible defenses. We tested this hypothesis by attempting to induce production of the antioxidant precursor dimethylsulfoniopropionate (DMSP) in 4 ulvoid algae species that experience different levels of environmental stress because they are zoned along a tidal gradient. The 2 lower intertidal speciesUlvaria obscuraandUlva fenestrata, which experience oxidative stresses less frequently, induced DMSP production in response to applications of the chemical oxidant hydrogen peroxide within 7 d, whereas the higher intertidal speciesUlva linzaandUlva intestinalis, which regularly experience oxidative stress, did not have increased DMSP concentrations. This study demonstrates a novel waterborne signaling mechanism for DMSP induction in marine macroalgae and provides evidence of selection for inducible antioxidant defenses in organisms experiencing less frequent environmental stresses.

A global perspective on the climate‐driven growth synchrony of neighbouring trees

AbstractAimPrevious work demonstrated the global variability of synchrony in tree growth within populations, that is, the covariance of the year‐to‐year variability in growth of individual neighbouring trees. However, there is a lack of knowledge about the causes of this variability and its trajectories through time. Here, we examine whether climate can explain variation in within‐population synchrony (WPS) across space but also through time and we develop models capable of explaining this variation. These models can be applied to the global tree cover under current and future climate change scenarios.LocationGlobal.Time period1901–2012.Major taxa studiedTrees.MethodsWe estimated WPS values from a global tree‐ring width database consisting of annual growth increment measurements from multiple trees at 3,579 sites. We used generalized linear mixed effects models to infer the drivers of WPS variability and temporal trends of global WPS. We then predicted WPS values across the global extent of tree cover. Finally, we applied our model to predict future WPS based on the RCP 8.5 (2045–2065 period) emission scenario.ResultsAreas with the highest WPS are characterized by a combination of environments with both high mean annual temperature (>10°C) and low precipitation (<300 mm). Average WPS across all temperate forests has decreased historically and will continue to decrease. Potential implications of these patterns include changes in forest dynamics, such as higher tree growth and productivity and an increase in carbon sequestration. In contrast, the WPS of tropical forests of Central and South America will increase in the near future owing to reduced annual precipitation.Main conclusionsClimate explains WPS variability in space and time. We suggest that WPS might have value as an integrative ecological measure of the level of environmental stress to which forests are subjected and therefore holds potential for diagnosing effects of global climate change on tree growth.

Assessing spatial patterns of soil erosion in a high‐latitude rangeland

AbstractHigh‐latitude areas are experiencing rapid change: we therefore need a better understanding of the processes controlling soil erosion in these environments. We used a spatiotemporal approach to investigate soil erosion in Svalbarðstunga, Iceland (66°N, 15°W), a degraded rangeland. We used three complementary datasets: (a) high‐resolution unmanned‐aerial vehicle imagery collected from 12 sites (total area ~0.75 km2); (b) historical imagery of the same sites; and (c) a simple, spatially‐explicit cellular automata model. Sites were located along a gradient of increasing altitude and distance from the sea, and varied in erosion severity (5–47% eroded). We found that there was no simple relationship between location along the environmental gradient and the spatial characteristics of erosion. Patch‐size frequency distributions lacked a characteristic scale of variation, but followed a power‐law distribution on five of the 12 sites. Present total eroded area is poorly related to current, site‐scale levels of environmental stress, but the number of small erosion patches did reflect site‐level stress. Small (<25 m2) erosion patches clustered near large patches. The model results suggested that the large‐scale patterns observed likely arise from strong, local interactions, which mean that erosion spreads from degraded areas. Our findings suggest that contemporary erosion patterns reflect historical stresses, as well as current environmental conditions. The importance of abiotic processes to the growth of large erosion patches and their relative insensitivity to current environmental conditions makes it likely that the total eroded area will continue to increase, despite a warming climate and reducing levels of grazing pressure.

Hypoxia-induced elevated NDRG1 mediates apoptosis through reprograming mitochondrial fission in HCC.

Hypoxia, as a form of stress, plays a critical role in oncogenesis, including metabolic reprogramming. Mitochondrial, the centers of energy production, re-balance mitochondria dynamic to maintain cell survival during high levels of environmental stresses. NDRG1 is a hypoxia-inducible protein that is involved in various human cancers, including HCC. However, little is known about whether NDRG1 participants in the quality control of mitochondrial in times of stress. Here, we firstly showed that how NDRG1 exerted its role through mediating mitochondrial dynamic in HCC cells under hypoxia. Initially, we identified that NDRG1 expression varies with oxygen content. NDRG1 silencing notably induced cell apoptosis under hypoxia, while no obviously change of wildtype cells in hypoxia compared with that in normoxia. Further analysis revealed that NDRG1 silencing in HCC cells led to increase of pro apoptotic protein BAX and decrease in anti-apoptotic proteins Bcl-2 and Bclx, which meant mitochondrial damage were induced. In the analysis of mitochondria, we found that more released cytochrome c located in cytosolic with NDRG1 knockdown in hypoxia, which may be due to mitochondria division. And the following experiment proved that more fragmented mitochondria were presented in NDRG1 silencing cells, as well as destroyed mitochondrial membrane potential with evidence by JC-1 was verified. Moreover, these trends could be reversed by Mdivi1. Further research showed that NDRG1 silencing disrupt hypoxia-enhanced aerobic glycolysis through effectively decreased glucose uptake, lactate output and ECAR value. In sum, we provide the first direct evidence that NDRG1-driven change in mitochondrial dynamics and aerobic glycolysis maintain cells survival in HCC during hypoxia.

Здатність деревних видів акумулювати важкі метали в умовах нафтозабруднених ґрунтів

Досліджено особливості акумуляції хімічних елементів деревними рослинами в умовах впливу Битків-Бабчинського нафтового родовища. Рентгенофлуоресцентним методом встановлено концентрацію алюмінію, цинку, титану, феруму, стронцію, нікелю, купруму, арсену, брому, рубідію, молібдену, паладію, аргентуму, плюмбуму, ванадію у сухій масі листкових пластинок клена гостролистого, бука лісового, ліщини звичайної, берези повислої, липи серцелистої та осики, що зростають у забрудненому нафтопродуктами довкіллі. За допомогою програм CorelDRAW та ImageJ розраховано частку некротизованої тканини асиміляційних органів деревних рослин в умовах впливу родовища. Встановлено прямо пропорційну залежність між ураженням листкових пластинок дерев некрозами та накопиченням хімічних елементів рослинами. Зафіксовано відсутність арсену, брому, молібдену, паладію, аргентуму, плюмбуму, ванадію у листках клена, бука, липи. Виявлено зростання вмісту хімічних елементів у асиміляційних органах дослідних дерев у такому ряді: Mo → Pb → Pd → Ag → Br → As → V → Ni → Rb → Cu → Sr → Ti → Zn → Fe → Al. Частка некротизації листків в умовах Битків-Бабчинського нафтового родовища зростає у ряді дослідних рослин: бук → клен → липа → осика → береза → ліщина. Максимальною акумулятивною здатністю хімічних елементів володіє ліщина, мінімальною – бук та клен. Враховуючи значні кумулятивні ресурси ліщини, доцільно використовувати вид як фіторемедіант забрудненого хімічними елементами довкілля. Клен та бук належать до рослин-елімінаторів, які вибірково та в невеликих кількостях поглинають токсиканти з довкілля, що зумовлено наявністю у цих видів потужних протекторних механізмів. Береза, липа та осика відзначаються цінними біоіндикаторними характеристиками та їх можна використовувати для оцінювання екологічного напруження середовища.

Enhanced phytochemical composition and biological activities of grape (Vitis vinifera L.) Stems growing in low altitude regions

The influence of altitude (ranging from 120−730 m) on different grape stem samples of the Região Demarcada do Douro (Portugal), upon their chemical and biological properties, was studied over two consecutive vintages.Grape stem samples revealed a significantly higher phenolic concentration at lower altitude regions (ranging from 78.02 ± 0.70–103.49 ± 4.36 mg of Gallic Acid g−1 in contrast to concentrations between 32.35 ± 3.35 and 88.32 ± 1.75 mg of Gallic Acid g−1), and, consequently, higher antioxidant activities (0.73 ± 0.00 - 0.85 ± 0.04 against 0.24 ± 0.06 - 0.75 ± 0.01 mmol Trolox g−1) regardless of the vintage. Furthermore, and as expected, a year-to-year variation was verified as there was a significant increase of these parameters from 2017 to 2018, except for the antimicrobial activity, which demonstrated not to be severally affected by the climate conditions of each year of study, however, the high altitude generally induced a lower activity in the samples, which was confirmed by the multivariate analysis.Altitude, along with the season, demonstrated a major impact on secondary metabolites of grape stems, inducing their concentrations at low altitude sites, related to higher environmental stress levels, such as, precipitation, whereby these factors must always be taken into consideration in future industrial applications.

Urban-greenway factors’ influence on older adults’ psychological well-being: A case study of Taichung, Taiwan

In Taiwan, about 80 % of the population lives in urban areas, and as the number of older adults inches toward 20 % of the total population by 2026, Taiwan is expected to become a super-aged society. Because urban green spaces are critical for maintaining older adults’ physio-psychological health, maintenance of these spaces can assist the aging-in-place process. Urban greenways not only provide physical environments that support leisure activities, but also create a social environment in which older adults can develop place attachment. These areas improve older adults’ psychological well-being. By contrast, urban environmental stressors (e.g., noise and air pollution) may affect older residents’ well-being negatively. Therefore, this study developed a structural equation model to examine the relationship between physical environment and well-being from urban greenways in Taichung, and it examined how local older residents’ place attachment and perceived environmental stressors influence this relationship. Our dataset included 13 greenways and 769 participants older than 55 living in the vicinity of these greenways. The results indicate that participants perceive lower levels of environmental stress when their local greenway quality is better, enhancing levels of well-being and place attachment, as reported by older adult residents. Since urban greenways are linear public spaces adjacent to roads, greenway designers and planners should place more emphasis on environmental quality to help create high-quality and easy-to-maintain public spaces where older adults can enjoy the outdoors and improve their well-being without worrying about environmental stressors.

Factors Affecting Stress Levels in Hospitalized Patients after Implementation of Fast.track Protocol in Hepatopancreatobiliary Surgery

Objective:The objective was to explore factors affecting stress levels in hospitalized patients after implementation of fast-track (FT) protocol in hepatopancreatobiliary surgery.Methods:This was a prospective cross-sectional study, where 90 patients were included. Exploration of environmental postoperative stress levels was conducted by serum adrenocorticotropic hormone and cortisol levels, the Intensive Care Unit Environmental Stressor Scale, and three self-reported Numeric Analog Scale questions, with regard to emotional/stress level, specifically “How sad do you feel right now?” “How stressed do you feel right now?” and “How optimistic do you feel right now, about the future?” at 3 time points: (T1) Before surgery, (T2) the day of surgery, and (T3) the 3rd postoperative day. The trial profile is conformed according to the CONSORT guidelines. Statistical analysis was carried out by SPSS software version 22 (IBM SPSS software, Chicago, Illinois, USA) at a significance level of 0.05.Results:Serum cortisol T2 levels were positively correlated with the day of removal the drainage tube (rho = 0.235, P = 0.027). Furthermore, serum cortisol T3 levels were positively correlated with age and body mass index and negatively with the day of drainage tube removal (rho = 0.231, P = 0.028, rho = 0.235, P = 0.026, and rho = −0.279, P = 0.008, respectively).Conclusions:The findings of this study highlight that after evaluation of stress levels; nurses could interfere and reduce stress levels, knowing the factors which cause the increased stress levels, after the implementation of FT protocols.

Are all patterns created equal? Cooperation is more likely in spatially simple habitats

AbstractCooperative behaviours, such as aggregation with neighbouring conspecifics, can enhance resilience in habitats where risks (i.e. predation, physical disturbances) are high, exerting positive feedback loops to maintain a healthy population. At the same time, cooperation behaviours can involve some extra energy expenditures and increasing resource competition. For sessile reefs, like mussels, simulation models predict increased cooperation under increasing levels of environmental stress. Predation risk is viewed as a behaviour‐modifying stressor, but its role on cooperation mechanisms, such as likelihood of reciprocity, has not yet been empirically tested. This study harnesses this framework to understand how cooperation changes under different perceived levels of predation risk, using mussel beds as model of a complex “self‐organised” system. Hence, we assessed the context dependency of cooperation response in different “landscapes of fear,” created by changes in predator cues, substratum availability and body size. Our experiments demonstrated that i) cooperation in a mussel bed system increases when predator cues are present, but that this relationship was found to be both, ii) strongly context‐dependent, particularly upon substratum availability and iii) size‐dependent. That is, while cooperation is in general greater for larger individuals, the response to risk results in greater cooperation when alternative attachment substratum is absent, meaning that simpler landscapes may be perceived as riskier. The context dependency of structural complexity is also an essential finding to consider in a changing world where habitats are losing complexity and cooperative strategies should be maximised.

Community assembly processes along a sub-Mediterranean elevation gradient: analyzing the interdependence of trait community weighted mean and functional diversity

Community-weighted mean (CWM) and functional diversity (FD) describe the two aspects of plant communities’ functional structure. While they have been often used separately to infer assembly processes, their covariation can actually provide useful insights into the prevalence of a particular assembly process over the other. We propose a framework where positive or negative covariation of these indices can be related to different assembly processes along an environmental gradient. We tested this framework in grassland communities along elevation gradient in Central Apennines by collecting species cover and traits of the most abundant species and calculating the effect size CWM and FD. We performed major axis regression for each effect size of CWM-FD relationship for different belts along the elevation gradient. The observation that Plant Height showed a positive CWM-FD relationship only under more stressful conditions indicates that there may be a tendency towards habitat filtering. Seed Mass showing positive covariation in each belt may indicate the presence of both habitat filtering and limiting similarity acting with different intensity depending on the environmental stress level. Negative covariation between CWM-Plant Height and Seed Mass-FD under less stress suggests biotic filter, while positive covariation between CWM-Plant Height and both Seed Mass and SLA FD under stressful conditions suggests the presence of habitat filtering. Ultimately, the relationship of CWM and FD may provide information on how different communities assemble along an environmental gradient. Moreover, combining the information of CWM with the FD and environmental stress level might help to identify the processes behind the same functional pattern.

Recovery ability of lowshore sessile assemblages in a highly contaminated post-industrial area

The inheritance of environmental contamination left by abandoned industrial plants is widespread globally. Here we compared the patterns of recovery of lowshore algal and invertebrate assemblages between the post-industrial site of Bagnoli-Coroglio and four reference sites distributed along the coast in the Gulf of Naples, southern Tyrrhenian Sea. The structure of whole assemblages, richness of taxa and abundance of individual taxa were followed during one year since an event of experimental disturbance consisting in the removal of all erect organisms from the rocky substrate. Our main findings suggest that the examined benthic assemblages recovered effectively and quickly after a pulse disturbance and, contrarily to initial expectations, that this ability was comparable between the post-industrial site and the reference sites. This result is discussed in terms of several plausible processes and mechanisms, including the general capability of intertidal organisms to recover from physical disturbance, the potential high level of environmental stress affecting the reference sites too, the chance that the most intense impacts of contamination remained restricted to the sediments of the post-industrial site without propagating to adjacent rocky habitats, and the large natural variability of reference sites that may have masked weak effects of the historical contamination. Irrespective of the actual causes, we emphasize the need for including natural variability of the examined system in any future restoration interventions, to guarantee representation of the range of variation of target organisms and of their underlying processes, and to avoid confounding the intended post-industrial impact with the effects of other natural and anthropogenic processes.

Correlations between a Flexible Parental Visiting Environment and Parental Stress in Neonatal Intensive Care Units

The purpose of this study was to examine the correlation between a flexible parental visiting environment and parental stress in neonatal intensive care units (NICUs). The study participants included 60 parents of premature infants in NICUs. Structured questionnaires and interviews, as well as observations by researchers using a caregiving behavior checklist, were used to measure the flexibility of the parental visiting environment and parents' stress levels. Quantitative and qualitative data were collected concurrently and were initially analyzed as separate data sets. Data collection extended from March 11, 2018 to June 30. 2018 and the data were analyzed using descriptive statistics, the independent t-test, one-way analysis of variance, and Pearson correlation coefficients. There was a negative correlation (r=-.30, p=.021) between parental stress and the total number of visits in 7 days. We also found that the average duration of each visit and the number of caregiving behaviors performed by parents were positively correlated (r=.73, p<.001). When designing a flexible visiting environment for parents, parents should be encouraged to visit their babies. By doing so, stress can be reduced both for babies and for parents. Therefore, it is suggested that the related polices and regulations in South Korea should be changed to provide more a flexible visiting environment to promote better parent-child attachment and family adjustment.

The Draft Genome of Kochia scoparia and the Mechanism of Glyphosate Resistance via Transposon-Mediated EPSPS Tandem Gene Duplication.

Increased copy number of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene confers resistance to glyphosate, the world’s most-used herbicide. There are typically three to eight EPSPS copies arranged in tandem in glyphosate-resistant populations of the weed kochia (Kochia scoparia). Here, we report a draft genome assembly from a glyphosate-susceptible kochia individual. Additionally, we assembled the EPSPS locus from a glyphosate-resistant kochia plant by sequencing select bacterial artificial chromosomes from a kochia bacterial artificial chromosome library. Comparing the resistant and susceptible EPSPS locus allowed us to reconstruct the history of duplication in the structurally complex EPSPS locus and uncover the genes that are coduplicated with EPSPS, several of which have a corresponding change in transcription. The comparison between the susceptible and resistant assemblies revealed two dominant repeat types. Additionally, we discovered a mobile genetic element with a FHY3/FAR1-like gene predicted in its sequence that is associated with the duplicated EPSPS gene copies in the resistant line. We present a hypothetical model based on unequal crossing over that implicates this mobile element as responsible for the origin of the EPSPS gene duplication event and the evolution of herbicide resistance in this system. These findings add to our understanding of stress resistance evolution and provide an example of rapid resistance evolution to high levels of environmental stress.

Microhabitats can be recruitment refuges and sinks

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 626:15-27 (2019) - DOI: https://doi.org/10.3354/meps13070 Microhabitats can be recruitment refuges and sinks Paul E. Carnell1,2,*, Michael A. Sams3, Michael J. Keough1 1School of BioSciences, The University of Melbourne, VIC 3010, Australia 2Deakin University, Geelong, Australia. School of Life and Environmental Sciences, Centre for Integrative Ecology, (Burwood Campus), 221 Burwood Highway, Burwood, VIC 3125, Australia 3Environment Protection Authority, Ernest Jones Drive, Macleod, VIC 3085, Australia *Corresponding author: paul.carnell@deakin.edu.au ABSTRACT: Recruitment is an important demographic bottleneck in the life history of many plant and animal species. Microhabitats provided by surfaces or plants or animals can reduce mortality during this critical life-history period. We investigated how microhabitats influence post-settlement processes on a range of ascidians, bryozoans and barnacles. We compared post-settlement mortality and growth on surfaces that were flat or were covered by artificial barnacle mimics or live adult barnacle microhabitats. We also tested whether the effects of surface type changed under different levels of environmental stress by manipulating the orientation of treatments. Orientation had the strongest influence on survival, growth and recruitment, with individuals on downwards-facing surfaces performing the best and those on upwards-facing surfaces with significantly higher mortality. The bryozoan Watersipora subatra had higher survival in microhabitats, but was not influenced by surface orientation. In contrast, barnacles showed increased mortality in microhabitats on upwards-facing panels, but were not affected by other orientations. The presence of adult barnacles caused decreased growth of barnacle recruits, but had no effect on the bryozoan. In comparison, the ascidians (Botryllus sclosseri and Diplosoma listerianum) were mostly not influenced by microhabitats. The high rates of sedimentation on upwards-facing surfaces provide the most plausible answer for the strong influences of surface orientation on survival and growth. While microhabitats can act as refuges for some species, the same microhabitat type can lead to higher mortality in other species. The response of each species to microhabitats ultimately depends on the source of mortality at each site. KEY WORDS: Post-settlement mortality · Habitat characteristics · Settlement · Environmental variability · Ascidian · Bryozoan · Barnacle Full text in pdf format PreviousNextCite this article as: Carnell PE, Sams MA, Keough MJ (2019) Microhabitats can be recruitment refuges and sinks. Mar Ecol Prog Ser 626:15-27. https://doi.org/10.3354/meps13070 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 626. Online publication date: September 12, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.

Effect of Landscape Elements on the Symmetry and Variance of the Spatial Distribution of Individual Birds within Foraging Flocks of Geese

Behavioural instability is a newly coined term used for measuring asymmetry of bilateral behavioural traits as indicators of genetic or environmental stress. However, this concept might also be useful for other types of data than bilateral traits. In this study, behavioural instability indices of expected behaviour were evaluated as an indicator for environmental stress through the application of aerial photos of foraging flocks of geese. It was presumed that geese would increase anti-predator behaviour through the dilution effect when foraging near the following landscape elements: wind turbines, hedgerows, and roads. On this presumption, it was hypothesized that behavioural instability of spatial distribution in flocks of geese could be used as indicators of environmental stress. Asymmetry in spatial distribution was measured for difference in flock density across various distances to disturbing landscape elements through the following indices; behavioural instability of symmetry and behavioural instability of variance. The behavioural instability indices showed clear tendencies for changes in flock density and variance of flock density for geese foraging near wind turbines, hedgerows, and roads indicating increasing environmental stress levels. Thus, behavioural instability has proven to be a useful tool for monitoring environmental stress that does not need bilateral traits to estimate instability but can be applied for indices of expected behaviour.

Interaction of Photoprotective and Acclimation Mechanisms in Ulva rigida (Chlorophyta) in Response to Diurnal Changes in Solar Radiation in Southern Chile.

Species of the genus Ulva (Chlorophyta) are regarded as opportunistic organisms, which efficiently adjust their metabolism to the prevailing environmental conditions. In this study, changes in chlorophyll-a fluorescence-based photoinhibition of photosynthesis, electron transport rates, photosynthetic pigments, lipid peroxidation, total phenolic compounds, and antioxidant metabolism were investigated during a diurnal cycle of natural solar radiation in summer (for 12h) under two treatments: photosynthetically active radiation (PAR: 400-700nm) and PAR+ ultraviolet (UV) radiation (280-700nm). In the presence of PAR alone, Ulva rigida showed dynamic photoinhibition, and photosynthetic parameters and pigment concentrations decreased with the intensification of the radiation. On the other hand, under PAR+UV conditions a substantial decline up to 43% was detected and an incomplete fluorescence recovery, also, P-I curve values remained low in relation to the initial condition. The phenolic compounds increased their concentration only in UV radiation treatments without showing a correlation with the antioxidant activity. The enzimatic activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX) increased over 2-fold respect at initial values during the onset of light intensity. In contrast, catalase (CAT) increased its activity rapidly in response to the radiation stress to reach maxima at 10a.m. and decreasing during solar. The present study suggests that U.rigida is capable of acclimating to natural radiation stress relies on a concerted action of various physiological mechanisms that act at different times of the day and under different levels of environmental stress.

Surface roughness condition of field-aged polymer insulators at different installation area

&lt;span&gt;This paper presents surface degradation assessment based on surface roughness condition for various field-aged high voltage polymer insulators that were installed at different locations. The measurement of arithmetical mean surface roughness is done, and statistical analysis is implemented in this study. Three groups of insulators labeled as 6 years, 12 years, 18 years, and with their respective controlled samples are tested using a surface roughness tester. Data measurements from the testing are analyzed in conjunction with visual observation to investigate an indication of surface degradation within the groups. Further statistical analysis is applied for the comparison of the surface roughness conditions. In order to observe the environmental stress factors that will affect the roughness condition, within the installation area, the virtual three-dimensional mapping program represented the Earth based on satellite imagery is utilized. The correlation analysis on all that three groups has indicated the positive outcomes with the roughness increased with respect to the age of insulator that located in quite similar environmental stress conditions. Regardless of the age of an insulator, the degradation due to surface roughness condition can be used to indicate what levels of environmental stress around the installation area have.&lt;/span&gt;

Uncovering a mitochondrial unfolded protein response in corals and its role in adapting to a changing world.

The Anthropocene will be characterized by increased environmental disturbances, leading to the survival of stress-tolerant organisms, particularly in the oceans, where novel marine diseases and elevated temperatures are re-shaping ecosystems. These environmental changes underscore the importance of identifying mechanisms which promote stress tolerance in ecologically important non-model species such as reef-building corals. Mitochondria are central regulators of cellular stress and have dedicated recovery pathways including the mitochondrial unfolded protein response, which increases the transcription of protective genes promoting protein homeostasis, free radical detoxification and innate immunity. In this investigation, we identify a mitochondrial unfolded protein response in the endangered Caribbean coral Orbicella faveolata, by performing in vivo functional replacement using a transcription factor (Of-ATF5) originating from a coral in the model organism Caenorhabditis elegans. In addition, we use RNA-seq network analysis and transcription factor-binding predictions to identify a transcriptional network of genes likely to be regulated by Of-ATF5 which is induced during the immune challenge and temperature stress. Overall, our findings uncover a conserved cellular pathway which may promote the ability of reef-building corals to survive increasing levels of environmental stress.