Stress Resistance in an Extreme Environment: Lessons Learnt from a Temperate Symbiotic Sea Anemone

Extreme Environment ◽

Sea Anemone ◽

Tide Pool ◽

Highly Sensitive ◽

Wide Range ◽

Symbiotic Dinoflagellates ◽

Global Concern ◽

<p>Coral bleaching, the loss of symbiotic dinoflagellates (zooxanthellae) or their photosynthetic pigments in response to environmental stress, is of huge global concern. In contrast to tropical corals, which are highly sensitive to fluctuations in environmental parameters such as temperature, light and salinity, zooxanthellate invertebrates in temperate waters rarely bleach despite highly variable conditions. In this study, we tested the effects of salinity with combined effects of light and temperature stress on the photophysiology and stability of the temperate symbiotic sea anemone, Anthopleura aureoradiata, through chlorophyll fluorescence. In the field it was demonstrated that A. aureoradiata was resilient to abiotic fluctuations of considerable magnitude in the intertidal zone. Salinity was revealed to range naturally between a winter low of 30 and summer high of 40 ppt in an elevated tide pool with no measurable effects on the photophysiology of A. aureoradiata residing within. In a controlled environment, only extreme high and low salinities had an effect on the zooxanthellar photosystem, with a wide range of tolerance between 15-50 ppt dependent on the levels of temperature and light. Both high and low light, and temperature, also impacted upon photophysiology. Moreover, each of these variables independently, as well as combined, exacerbated the impact of salinity stress. In addition, the duration of exposure played an important role in the survival of this symbiosis, with only 48-96 h exposure to the extreme salinities of 5, 10, 55 and 60 ppt inducing irreversible photosynthetic failure, bleaching and death. Thus, the data supports the idea that this anemone-zooxanthellar symbiosis is highly resilient to considerable amounts of abiotic stress, a likely a function of the robust photophysiology of its zooxanthellae. This resilience to bleaching suggests that A. aureoradiata and its zooxanthallae have evolved a combination of powerful defensive mechanisms to help aid against the heterogenous environment from which they come. I will present an overview of these osmoregulatory mechanisms, photoacclimatory strategies and behaviours that this symbiosis likely deploys in order to combat environmentally realistic ranges in abiotic factors. Further studies would be necessary to deduce whether it is the host or zooxanthellae which are responsible for the breakdown of this symbiosis.</p>

Stress Resistance in an Extreme Environment: Lessons Learnt from a Temperate Symbiotic Sea Anemone

10.26686/wgtn.16973977 ◽

2021 ◽

Author(s):

◽

Milena Sylwia Palka

Keyword(s):

Abiotic Factors ◽

Extreme Environment ◽

Sea Anemone ◽

Tide Pool ◽

Highly Sensitive ◽

Wide Range ◽

Symbiotic Dinoflagellates ◽

Global Concern ◽

Design relations for predicting surface-ice clearing capacity of open channels

Canadian Journal of Civil Engineering ◽

10.1139/l00-081 ◽

2000 ◽

Vol 27 (6) ◽

pp. 1230-1239 ◽

Cited By ~ 4

Author(s):

I Morin ◽

R D Townsend ◽

B Morse

Keyword(s):

Operating Conditions ◽

Water Current ◽

Ambient Conditions ◽

Navigation Channel ◽

Wide Range ◽

Ice Concentration ◽

Wind Characteristics ◽

Surface Ice ◽

Numerical simulations are performed to evaluate the impact of various hydraulic and environmental parameters on the ice clearing capacity of a Lac St-Pierre navigation channel. The Lagrangian particle-dynamics (Pdyn) model is used to simulate a wide range of "operating" conditions that are representative of conditions observed on Lac St-Pierre. Simple relationships are developed that express both ice velocity and flux as functions of the geometry of the channel (width and plan-form shape) and ambient conditions (ice concentration, thickness, water current, wind magnitude and direction). These relationships reflect the importance of wind characteristics and areal ice concentration in regard to predicting both surface ice velocities and flux.Key words: ice clearing, channel geometry, ambient conditions.

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

A discussion on deformation of solids by the impact of liquids, and its relation to rain damage in aircraft and missiles, to blade erosion in steam turbines, and to cavitation erosion - Damage to solids caused by cavitation

10.1098/rsta.1966.0048 ◽

1966 ◽

Vol 260 (1110) ◽

pp. 245-255 ◽

Cited By ~ 15

Keyword(s):

Mechanical Properties ◽

Cavitation Erosion ◽

Cavitation Resistance ◽

Steam Turbines ◽

Single Event ◽

Cavitation Damage ◽

Erosion Damage ◽

Highly Sensitive ◽

Wide Range ◽

This paper describes the early stages of cavitation damage observed in cavitating venturi tunnels. The cavitating fluids were water and mercury, and a wide range of specimen materials were used. The damage was found to consist of single-event symmetical craters and irregular fatigue-type failures. The degree of damage was highly sensitive to minor flow perturbations, and this is discussed. The effect of stress level in the specimen before testing, and relations between cavitation resistance and the mechanical properties of the materials are considered.

Plant-microbe Cross-talk in the Rhizosphere: Insight and Biotechnological Potential

The Open Microbiology Journal ◽

10.2174/1874285801509010001 ◽

2015 ◽

Vol 9 (1) ◽

pp. 1-7 ◽

Cited By ~ 47

Author(s):

Shyamalina Haldar ◽

Sanghamitra Sengupta

Keyword(s):

Developmental Stages ◽

Biological Activities ◽

Abiotic Factors ◽

Host Genotype ◽

Nature Restoration ◽

Microbiological Techniques ◽

Microbe Interactions ◽

Structural Principles ◽

Rhizosphere, the interface between soil and plant roots, is a chemically complex environment which supports the development and growth of diverse microbial communities. The composition of the rhizosphere microbiome is dynamic and controlled by multiple biotic and abiotic factors that include environmental parameters, physiochemical properties of the soil, biological activities of the plants and chemical signals from the plants and bacteria which inhabit the soil adherent to root-system. Recent advancement in molecular and microbiological techniques has unravelled the interactions among rhizosphere residents at different levels. In this review, we elaborate on various factors that determine plant-microbe and microbe-microbe interactions in the rhizosphere, with an emphasis on the impact of host genotype and developmental stages which together play pivotal role in shaping the nature and diversity of root exudations. We also discuss about the coherent functional groups of microorganisms that colonize rhizosphere and enhance plant growth and development by several direct and indirect mechanisms. Insights into the underlying structural principles of indigenous microbial population and the key determinants governing rhizosphere ecology will provide directions for developing techniques for profitable applicability of beneficial microorganisms in sustainable agriculture and nature restoration.

Influence of environmental parameters on bacterial lipids in soils from the French Alps: implications for paleo-reconstructions

10.5194/egusphere-egu2020-501 ◽

2020 ◽

Author(s):

Pierre Véquaud ◽

Sylvie Derenne ◽

Sylvie Collin ◽

Christelle Anquetil ◽

Jérôme Poulenard ◽

...

Keyword(s):

Lipid Membrane ◽

Lacustrine Sediments ◽

Soil Types ◽

Major Influence ◽

French Alps ◽

Wide Range ◽

Main Driver ◽

The One ◽

<p>Microorganisms can modify the composition of their lipid membrane in response to variations in environmental parameters. This is the case for bacterial lipids such as glycerol dialkyl tetraethers (GDGT) and 3-hydroxy fatty acids (3-OH FAs), both used for temperature and pH reconstructions in terrestrial paleoenvironmental studies. However, a major concern with these proxies is that their structure may be influenced by other environmental parameters than temperature or pH. The present study aimed at identifying and quantifying the influence of environmental parameters such as soil moisture, vegetation types and soil types on bacterial GDGTs and 3-OH FAs. These lipids were analyzed in 49 soil samples collected between 200 m and 3,000 m altitude in the French Alps. The soils cover a wide range of temperature (0 &#176;C to 15 &#176;C) and pH (3 to 8) and are representative of the diversity of soils and vegetation encountered along the investigated altitudinal transects. Using this new well-documented and unique dataset, the GDGT-pH correlation was confirmed, but the one between 3-OH FAs and pH was lower than in previous studies. For the temperature, correlations were lower than in previous studies for the GDGTs and absent for the 3-OH FAs. These observations could be explained thanks to different statistical analyses. Redundancy analysis (RDA) showed that pH is the main driver of the variability of 3-OH FAs and GDGTs, explaining 20.5 % and 56 % of the distribution of these bacterial lipids, respectively, followed by the altitude (8 % influence on the distribution of 3-OH FAs, and 11 % on GDGTs) and granulometry (5 % impact on 3-OH FAs and 7.5 % on GDGTs). Taken together, these results highlight the major influence of the vegetation cover and soil types on the distribution of bacterial lipids. Indeed, we quantified and explained for the first time the impact of the different environmental factors (temperature, vegetation, soil type&#8230;) on the distribution of bacterial lipids. This novel comprehension of the impacts of environmental parameters will allow to refine the use of proxies based on these compounds. These results pave the way for new types of applications of GDGTs and 3-OH FAs as environmental proxies in paleosoils, peat or lacustrine sediments.</p>

Evening home lighting adversely impacts the circadian system and sleep

Scientific Reports ◽

10.1038/s41598-020-75622-4 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Sean W. Cain ◽

Elise M. McGlashan ◽

Parisa Vidafar ◽

Jona Mustafovska ◽

Simon P. N. Curran ◽

...

Keyword(s):

Energy Efficient ◽

Light Sensitivity ◽

Circadian System ◽

Light Environment ◽

The Sun ◽

Individual Level ◽

Highly Sensitive ◽

Wide Range ◽

Specific Individual ◽

Abstract The regular rise and fall of the sun resulted in the development of 24-h rhythms in virtually all organisms. In an evolutionary heartbeat, humans have taken control of their light environment with electric light. Humans are highly sensitive to light, yet most people now use light until bedtime. We evaluated the impact of modern home lighting environments in relation to sleep and individual-level light sensitivity using a new wearable spectrophotometer. We found that nearly half of homes had bright enough light to suppress melatonin by 50%, but with a wide range of individual responses (0–87% suppression for the average home). Greater evening light relative to an individual’s average was associated with increased wakefulness after bedtime. Homes with energy-efficient lights had nearly double the melanopic illuminance of homes with incandescent lighting. These findings demonstrate that home lighting significantly affects sleep and the circadian system, but the impact of lighting for a specific individual in their home is highly unpredictable.

Study of Temporal Variations in Species–Environment Association through an Innovative Multivariate Method: MixSTATICO

Sustainability ◽

10.3390/su13115924 ◽

2021 ◽

Vol 13 (11) ◽

pp. 5924

Author(s):

Mariela González-Narváez ◽

María José Fernández-Gómez ◽

Susana Mendes ◽

José-Luis Molina ◽

Omar Ruiz-Barzola ◽

...

Keyword(s):

Environmental Changes ◽

Abiotic Factors ◽

Skeletonema Costatum ◽

Species Conservation ◽

Biological Indicators ◽

Temporal Variations ◽

Multivariate Method ◽

Eastern Equatorial Pacific ◽

The study of biotic and abiotic factors and their interrelationships is essential in the preservation of sustainable marine ecosystems and for understanding the impact that climate change can have on different species. For instance, phytoplankton are extremely vulnerable to environmental changes and thus studying the factors involved is important for the species’ conservation. This work examines the relationship between phytoplankton and environmental parameters of the eastern equatorial Pacific, known as one of the most biologically rich regions in the world. For this purpose, a new multivariate method called MixSTATICO has been developed, allowing mixed-type data structured in two different groups (environment and species) to be related and measured on a space–time scale. The results obtained show how seasons have an impact on species–environment relations, with the most significant association occurring in November and the weakest during the month of May (change of season). The species Lauderia borealis, Chaetoceros didymus and Gyrodinium sp. were not observed in the coastal profiles during the dry season at most stations, while during the rainy season, the species Dactyliosolen antarcticus, Proboscia alata and Skeletonema costatum were not detected. Using MixSTATICO, species vulnerable to specific geographical locations and environmental variations were identified, making it possible to establish biological indicators for this region.

Relationship between Environmental Conditions and Structure of Macroinvertebrate Community in a Hydromorphologically Altered Pre-Alpine River

Water ◽

10.3390/w12112987 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2987

Author(s):

Igor Zelnik ◽

Tjaša Muc

Keyword(s):

Plant Species ◽

Environmental Conditions ◽

Riparian Zone ◽

Abiotic Factors ◽

Macroinvertebrate Community ◽

Alien Plant Species ◽

Alien Plant ◽

Invasive Alien Plant ◽

Wide Range

Hydromorphological alterations influence a wide range of environmental conditions as well as riparian vegetation and the structure of the macroinvertebrate community. We studied relationships between the structure and diversity of the macroinvertebrate community and hydromorphological and other environmental conditions in the river Gradaščica (central Slovenia). The Gradaščica river is a pre-Alpine torrential river that has been morphologically altered by humans. A selection of abiotic factors was measured, the ecomorphological status of the river was assessed, vegetation in the riparian zone was surveyed and benthic macroinvertebrates were sampled. Correlations between diversity and the structure of the macroinvertebrate community, environmental parameters and occurrence of invasive alien plant species in the riparian zone were identified. The significance of the influence of environmental parameters on the structure of the macroinvertebrate community was examined. We found that hydromorphological alterations in the river have had a significant influence on the diversity and composition of the macroinvertebrate community because of changes of flow velocity and the spread of invasive alien plant species that has followed those changes. Factors that also significantly influence the composition of macroinvertebrate community are distance from the source and conductivity. Our findings suggest minimization of further human hydromorphological changes of watercourses could prevent the loss of biodiversity of riverine ecosystems.

The Impact of Environmental Factors on the Efficacy of Chemical Communication in the Burying Beetle (Coleoptera: Silphidae)

Journal of Insect Science ◽

10.1093/jisesa/ieaa061 ◽

2020 ◽

Vol 20 (4) ◽

Author(s):

Johanna Chemnitz ◽

Christian von Hoermann ◽

Manfred Ayasse ◽

Sandra Steiger

Keyword(s):

Land Use ◽

Biotic Interactions ◽

Burying Beetle ◽

Human Land Use ◽

Wide Range ◽

Nicrophorus Vespilloides ◽

Insect Sex Pheromones ◽

Animal Communities ◽

Abstract There is growing evidence that a wide range of insect sex pheromones are condition dependent and play a fundamental role in mate choice. However, the effectiveness of pheromonal communication might not only depend on internal factors of the sender, but also on attributes of the microhabitat, in which the signaler chooses to emit its chemical signal. For example, the degree of anthropogenic land use might affect how successful the signal is transmitted, as land use has been shown to affect animal communities and the complexity of biotic interactions. To test the hypothesis that parameters of the microenvironment determine males’ ability to attract females via their sex pheromone, we used the burying beetle Nicrophorus vespilloides Herbst (Coleoptera: Silphidae) as our model system. We exposed 144 males across differently managed forest stands and analyzed the impact of 29 environmental parameters. Our data revealed that human land use intensity had no effect on a male’s attractiveness. However, the harvested tree biomass positively affected the proportion of competitors attracted. Furthermore, we found that soil characteristics were important factors determining the amount and body size of females a male was able to attract. Consequently, we present evidence that the environmental context of a signaling male influences the effectiveness of chemical signaling either because it affects the transmission process or the prevailing abundance of potential signal receivers. Thus, our results demonstrate that males need to make careful decisions about the location where they emit their pheromone, as this choice of microhabitat has an impact on their fitness.

In situ AFM visualization of Li–O2 battery discharge products during redox cycling in an atmospherically controlled sample cell

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.10.94 ◽

2019 ◽

Vol 10 ◽

pp. 930-940 ◽

Cited By ~ 2

Author(s):

Kumar Virwani ◽

Younes Ansari ◽

Khanh Nguyen ◽

Francisco José Alía Moreno-Ortiz ◽

Jangwoo Kim ◽

...

Keyword(s):

Electrochemical Impedance ◽

Double Layers ◽

In Situ Observation ◽

Force Microscopy ◽

Atomic Force ◽

Highly Sensitive ◽

Wide Range ◽

Battery Discharge ◽

The in situ observation of electrochemical reactions is challenging due to a constantly changing electrode surface under highly sensitive conditions. This study reports the development of an in situ atomic force microscopy (AFM) technique for electrochemical systems, including the design, fabrication, and successful performance of a sealed AFM cell operating in a controlled atmosphere. Documentation of reversible physical processes on the cathode surface was performed on the example of a highly reactive lithium–oxygen battery system at different water concentrations in the solvent. The AFM data collected during the discharge–recharge cycles correlated well with the simultaneously recorded electrochemical data. We were able to capture the formation of discharge products from correlated electrical and topographical channels and measure the impact of the presence of water. The cell design permitted acquisition of electrochemical impedance spectroscopy, contributing information about electrical double layers under the system’s controlled environment. This characterization method can be applied to a wide range of reactive surfaces undergoing transformations under carefully controlled conditions.