scholarly journals Microbiota mediated plasticity promotes thermal adaptation in Nematostella vectensis

2021 ◽  
Author(s):  
Laura Baldassarre ◽  
Hua Ying ◽  
Adam Reitzel ◽  
Sebastian Fraune
Keyword(s):  
High Temperature ◽  
Environmental Changes ◽  
Genetic Recombination ◽  
Thermal Adaptation ◽  
Nematostella Vectensis ◽  
Next Generation ◽  
Host Genotype ◽  
Wide Range ◽  
Long Term Experiment ◽  
The Impact

At the current rate of climate change, it is unlikely that multicellular organisms will be able to adapt to changing environmental conditions through genetic recombination and natural selection alo. Thus, it is critical to understand alternative mechanisms that allow organisms to cope with rapid environmental changes. Here, we used the sea anemone Nematostella vectensis as model to investigate the microbiota as putative source of rapid adaptation. Living in estuarine ecosystems, highly variable aquatic environments, N. vectensis has evolved the capability of surviving in a wide range of temperatures and salinities. In a long-term experiment, we acclimated polyps of Nematostella to low, medium and high temperatures, in order to test the impact of microbiota-mediated plasticity on animal acclimation. Using the same animal clonal line, propagated from a single polyp, allowed us to eliminate effects of the host genotype. Interestingly, the higher thermal tolerance of animals acclimated to high temperature, could be transferred to non-acclimated animals through microbiota transplantation. In addition, offspring survival was highest from mothers acclimated to high temperature, indicating the transmission of thermal resistance to the next generation. Microbial community analyses of the F1 generation revealed the transmission of the acclimated microbiota to the next generation. These results indicate that microbiota plasticity can contribute to animal thermal acclimation and its transmission to the next generation may represent a rapid mechanism for thermal adaptation.

scholarly journals THE FRENCH 47TH INFANTRY REGIMENT DURING THE FIRST WORLD WAR: AN ENVIRONMENTAL APPROACH

2021 ◽  
pp. 17-26
Author(s):  
E. Le Gall ◽  
Keyword(s):  
Environmental Changes ◽  
First World War ◽  
World War ◽  
Physical Strain ◽  
French Army ◽  
Wide Range ◽  
The First World War ◽  
Warfare Agents ◽  
The Impact ◽  
First World

The First World War can be examined from the perspective of traditional military history as well as the perspective of the relationship between combatants and the environment. The author reveals based on a wide range of archival materials, printed media and ego-documents (diaries, memoirs, letters) the question of combat peculiarities of the 47th Infantry Regiment of the French Army considering with the influence of environmental conditions on the soldiers. The author demonstrates the dependence of the regiment's intensity and efficiency of combat operations on the terrain, weather and climate changes on the Western Front of the First World War. In the first phase of the conflict, soldiers were extremely vulnerable to even the slightest temperature changes (extreme heat, cold) due to their uniforms' problems. Physical strain from long marches across unfamiliar terrain and an extended stay in the trenches also harmed their health. The combat unit's active influence on the environment is also emphasised, with the pollution of the battlefield by sewage, leftover ammunition and weapons. The soldiers' health being adversely affected by the polluted environment (above all, the spread of contagious diseases, poisoning by chemical and metal warfare agents) is also considered. Severe environmental changes during battles also made combat operations more difficult. Thus, during the First World War, both the soldiers of the 47th Infantry Regiment of the French Army and all the other poilus became hostages to a severely altered environment due to the impact of millions of combatants.

scholarly journals A lattice-automaton bioturbation simulator with coupled physics, chemistry, and biology in marine sediments (eLABS v0.2)

2019 ◽  
Vol 12 (10) ◽  
pp. 4469-4496
Author(s):  
Yoshiki Kanzaki ◽  
Bernard P. Boudreau ◽  
Sandra Kirtland Turner ◽  
Andy Ridgwell
Keyword(s):  
Marine Sediments ◽  
Environmental Changes ◽  
Benthic Fauna ◽  
Benthic Organism ◽  
Numerical Representation ◽  
Biological Engineering ◽  
Spatial And Temporal Scales ◽  
Wide Range ◽  
Sediment Mixing ◽  
The Impact

Abstract. Seawater–sediment interaction is a crucial factor in carbon and nutrient cycling on a wide range of spatial and temporal scales. This interaction is mediated not just through geochemistry but also via biology. Infauna vigorously mix sediment particles, enhance porewater–seawater exchange, and consequently, facilitate chemical reactions. In turn, the ecology and activity of benthic fauna are impacted by their environment, amplifying the sensitivity of seawater–sediment interaction to environmental change. However, numerical representation of the bioturbation of sediment has often been treated simply as an enhanced diffusion of solutes and solids. Whilst reasonably successful in representing the mixing of bulk and predominantly oxic marine sediments, the diffusional approach to bioturbation is limited by a lack of environmental sensitivity. To better capture the mechanics and effects of sediment bioturbation, we extend a published bioturbation model (Lattice-Automaton Bioturbation Simulator; LABS) by adopting a novel method to simulate realistic infaunal behavior that drives sediment mixing. In this new model (extended LABS – eLABS), simulated benthic organism action is combined with a deterministic calculation of water flow and oxygen and organic matter concentration fields to better reflect the physicochemical evolution of sediment in response to bioturbation. The predicted burrow geometry and mixing intensity thus attain a dependence on physicochemical sedimentary conditions. This interplay between biology, chemistry, and physics is important to mechanistically explain empirical observations of bioturbation and to account for the impact of environmental changes. As an illustrative example, we show how higher organic rain can drive more intense sediment mixing by “luring” benthic organisms deeper into sediments, while lower ambient dissolved oxygen restricts the oxic habitat depth and hence tends to reduce bulk mixing rates. Our model, with its oxygen and food availability controls, is a new tool to interpret the trace fossil record, e.g., burrows, as well as to explore biological engineering of past marine environments.

Use of Electrothermal Explosion and Electro-Thermal Analyser (ETA-100) for the Study the Kinetics of Fast High-Temperature Reactions in SHS-Ceramic Systems

2010 ◽  
Vol 63 ◽  
pp. 203-212
Author(s):  
A.S. Shteinberg ◽  
A.A. Berlin
Keyword(s):  
High Temperature ◽  
Rate Constants ◽  
High Speed ◽  
Dissimilar Materials ◽  
Isothermal Kinetics ◽  
Hard Alloys ◽  
Wide Range ◽  
Static Conditions ◽  
The Impact ◽  
Kinetics Of

Due to the lack of specialty kinetic methods and instruments, the kinetics of fast hightemperature reactions SHS-ceramic systems has not been adequately studied. Recently, we have developed a number of methods of so-called non-isothermal kinetics (NIK) and designed instruments allowing one to obtain information about reactions of ceramic systems in a wide range of practically important temperatures and rates. The use of one of the NIK-methods (called electrothermal analysis based on the phenomena of electro thermal explosion) allows one to study kinetics of SHS of some ceramic materials characterized by the total reaction time ~ 10 μs. In ETE, both samples pressed from reagents powders or cylindrical samples made from tightly rolled foils were studied. The joule heating was accompanied by high-speed scanning of the non-stationary temperature field on its surface. Description and technical characteristics of the specialty device electrothermoanalyzer ETA-100 manufactured by ALOFT are given. Kinetic parameters of fast EM reactions for the temperatures up to 3600 K can be measured by ETE method using ETA-100. New kinetic data for fast high-temperature gasless SHS yielding individual and composite materials (including refractory carbides and borides of transition metals, silicon and boron carbides, some refractory oxides and hard alloys) are presented. At high-speed impact of the samples, the reaction rate constants were found to exceed the combustion rate constants (measured by ETA-100) by many orders of magnitude. It was concluded that the kinetic mechanisms of the corresponding fast reactions in the static conditions and under the impact are dramatically different. It was shown that SHS in ETE mode has a significant potential as a modern practical method to be used for welding of refractory and dissimilar materials, production of coarse superabrasives, etc.

scholarly journals A lattice-automaton bioturbation simulator for the coupled physics, chemistry, and biology of marine sediments (eLABS v0.1)

2019 ◽  
Author(s):  
Yoshiki Kanzaki ◽  
Bernard P. Boudreau ◽  
Sandra Kirtland Turner ◽  
Andy Ridgwell
Keyword(s):  
Marine Sediments ◽  
Environmental Changes ◽  
Benthic Fauna ◽  
Benthic Organism ◽  
Numerical Representation ◽  
Biological Engineering ◽  
Spatial And Temporal Scales ◽  
Wide Range ◽  
Sediment Mixing ◽  
The Impact

Abstract. Seawater-sediment interaction is a crucial factor in the dynamics of carbon and nutrient cycling on a wide range of spatial and temporal scales. This interaction is mediated not just through geochemistry, but also via biology. Infauna vigorously mix sediment particles, enhance porewater-seawater exchange and consequently facilitate chemical reactions. In turn, the ecology and activity of benthic fauna are impacted by their environment, amplifying the sensitivity of seawater-sediment interaction to environmental change. However, numerical representation of the bioturbation of sediment has often been treated simply as an enhanced diffusion of solutes and solids. Whilst reasonably successful in representing the mixing of bulk and predominantly oxic marine sediments, the diffusional approach to bioturbation is limited by lacking an environmental sensitivity. To better capture the mechanics and effects of sediment bioturbation, we summarize and extend a published bioturbation model (acronym: LABS) that adopts a novel lattice automaton method to simulate the behaviors of infauna that drive sediment mixing. In this new model (eLABS), simulated benthic organism behavior is combined with a deterministic calculation of water flow and oxygen and organic matter concentration fields to better reflect the physicochemical evolution of sediment. The predicted burrow geometry and mixing intensity thus attain a dependence on physicochemical sedimentary conditions. Such an interplay between biology, chemistry and physics can be important to mechanistically explain empirical observations of bioturbation and to account for the impact of environmental changes. As an illustrative example, we show how higher organic rain can drive more intense sediment mixing by luring benthic organisms deeper into sediments, while lower ambient dissolved oxygen restricts the oxic habitat depth and hence tends to reduce bulk mixing rates. Finally, our model, with its oxygen and food availability controls, represents a new tool to interpret the geological record of trace fossils, e.g., burrows, as well as to mechanistically explore biological engineering of early marine environments.

scholarly journals Experimental warming reduces gut prokaryotic diversity, survival and thermal tolerance of the eastern subterranean termite, Reticulitermes flavipes (Kollar)

2020 ◽  
Author(s):  
Rachel A. Arango ◽  
Sean D. Schoville ◽  
Cameron R. Currie ◽  
Camila Carlos-Shanley
Keyword(s):  
High Temperature ◽  
Environmental Changes ◽  
Reticulitermes Flavipes ◽  
Bacterial Symbionts ◽  
Integral Role ◽  
Potential Link ◽  
Microbial Symbionts ◽  
Temperature Exposure ◽  
Eastern Subterranean Termite ◽  
The Impact

AbstractUnderstanding the effects of environmental disturbances on the health and physiology of insects is crucial in predicting the impact of climate change on their distribution, abundance, and ecology. As microbial symbionts have been shown to play an integral role in a diversity of functions within the insect host, research examining how organisms adapt to environmental fluctuations should include their associated microbiota. Previous studies have shown that temperature affects the diversity of protists in termite gut, but less is known about the bacterial symbionts. In this study, subterranean termites (Reticulitermes flavipes (Kollar)) were exposed to three different temperature treatments characterized as low (15 °C), medium (27 °C), and high (35 °C). Results showed low temperature exposed termites had significantly lower CTmin and significantly higher SCP values compared to termites from medium or high temperature groups. This suggests that pre-exposure to cold allowed termites to stay active longer in decreasing temperatures but caused termites to freeze at higher temperatures. High temperature exposure had the most deleterious effects on termites with a significant reduction in termite survival as well as reduced ability to withstand cold stress. The microbial community of high temperature exposed termites showed a reduction in bacterial richness and decreased relative abundance of Spirochaetes, Elusimicrobia, and methanogenic Euryarchaeota. Our results indicate a potential link between gut bacterial symbionts and termite’s physiological response to environmental changes and highlight the need to consider microbial symbionts in studies relating to insect thermosensitivity.

scholarly journals Experimental Warming Reduces Survival, Cold Tolerance, and Gut Prokaryotic Diversity of the Eastern Subterranean Termite, Reticulitermes flavipes (Kollar)

2021 ◽  
Vol 12 ◽  
Author(s):  
Rachel A. Arango ◽  
Sean D. Schoville ◽  
Cameron R. Currie ◽  
Camila Carlos-Shanley
Keyword(s):  
High Temperature ◽  
Environmental Changes ◽  
Reticulitermes Flavipes ◽  
Prokaryotic Diversity ◽  
Integral Role ◽  
Potential Link ◽  
Microbial Symbionts ◽  
Temperature Exposure ◽  
Eastern Subterranean Termite ◽  
The Impact

Understanding the effects of environmental disturbances on insects is crucial in predicting the impact of climate change on their distribution, abundance, and ecology. As microbial symbionts are known to play an integral role in a diversity of functions within the insect host, research examining how organisms adapt to environmental fluctuations should include their associated microbiota. In this study, subterranean termites [Reticulitermes flavipes (Kollar)] were exposed to three different temperature treatments characterized as low (15°C), medium (27°C), and high (35°C). Results suggested that pre-exposure to cold allowed termites to stay active longer in decreasing temperatures but caused termites to freeze at higher temperatures. High temperature exposure had the most deleterious effects on termites with a significant reduction in termite survival as well as reduced ability to withstand cold stress. The microbial community of high temperature exposed termites also showed a reduction in bacterial richness and decreased relative abundance of Spirochaetes, Elusimicrobia, and methanogenic Euryarchaeota. Our results indicate a potential link between gut bacterial symbionts and termite’s physiological response to environmental changes and highlight the need to consider microbial symbionts in studies relating to insect thermosensitivity.

Impacts of Multiple Stressors on a Benthic Foraminiferal Community: A Long-Term Experiment Assessing Response to Ocean Acidification, Hypoxia and Warming

2021 ◽  
Vol 8 ◽  
Author(s):  
Joan M. Bernhard ◽  
Johannes C. Wit ◽  
Victoria R. Starczak ◽  
David J. Beaudoin ◽  
William G. Phalen ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Environmental Changes ◽  
Multiple Stressors ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Species Responses ◽  
Combined Impact ◽  
The Impact

Ocean chemistry is changing as a result of human activities. Atmospheric carbon dioxide (CO2) concentrations are increasing, causing an increase in oceanic pCO2 that drives a decrease in oceanic pH, a process called ocean acidification (OA). Higher CO2 concentrations are also linked to rising global temperatures that can result in more stratified surface waters, reducing the exchange between surface and deep waters; this stronger stratification, along with nutrient pollution, contributes to an expansion of oxygen-depleted zones (so called hypoxia or deoxygenation). Determining the response of marine organisms to environmental changes is important for assessments of future ecosystem functioning. While many studies have assessed the impact of individual or paired stressors, fewer studies have assessed the combined impact of pCO2, O2, and temperature. A long-term experiment (∼10 months) with different treatments of these three stressors was conducted to determine their sole or combined impact on the abundance and survival of a benthic foraminiferal community collected from a continental-shelf site. Foraminifera are well suited to such study because of their small size, relatively rapid growth, varied mineralogies and physiologies. Inoculation materials were collected from a ∼77-m deep site south of Woods Hole, MA. Very fine sediments (<53 μm) were used as inoculum, to allow the entire community to respond. Thirty-eight morphologically identified taxa grew during the experiment. Multivariate statistical analysis indicates that hypoxia was the major driving factor distinguishing the yields, while warming was secondary. Species responses were not consistent, with different species being most abundant in different treatments. Some taxa grew in all of the triple-stressor samples. Results from the experiment suggest that foraminiferal species’ responses will vary considerably, with some being negatively impacted by predicted environmental changes, while other taxa will tolerate, and perhaps even benefit, from deoxygenation, warming and OA.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

THE IMPACT OF LEADERSHIP PRACTICES TO TEAM MEMBERS’ SATISFACTION

2009 ◽  
Vol 8 (1) ◽  
Author(s):  
Chalimah .
Keyword(s):  
Conflict Resolution ◽  
Leadership Practices ◽  
Hotel Industry ◽  
Leader Behavior ◽  
Team Leader ◽  
Shop Floor ◽  
Team Members ◽  
Top Executives ◽  
Wide Range ◽  
The Impact

eamwork is becoming increasingly important to wide range of operations. It applies to all levels of the company. It is just as important for top executives as it is to middle management, supervisors and shop floor workers. Poor teamwork at any level or between levels can seriously damage organizational effectiveness. The focus of this paper was therefore to examine whether leadership practices consist of team leader behavior, conflict resolution style and openness in communication significantly influenced the team member’s satisfaction in hotel industry. Result indicates that team leader behavior and the conflict resolution style significantly influenced team member satisfaction. It was surprising that openness in communication did not affect significantly to the team members’ satisfaction.

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