Effects Of Extreme Environmental Conditions Research Articles

Freediving, Hypoxia, and Inflammation: Physiological Adaptations and Interactions between HIF and NF-κB

Freediving presents a unique set of physiological challenges and adaptations, making it a subject of interest for researchers studying the effects of extreme environmental conditions on the human body. There is a complex interplay between freediving, hypoxia, immune responses, and inflammation, shedding light on the physiological effects of freediving on the human body. This article describes how HIF and NF-κB interact during hypoxia and inflammation, including their synergistic effects and signaling pathways. The regulatory loop involving these transcription factors is highlighted, providing insight into their linked roles in modulating the cellular response to hypoxia and inflammation.

Effects of isolation and confinement on gastrointestinal microbiota-a systematic review.

The gastrointestinal (GI) microbiota is a complex and dynamic ecosystem whose composition and function are influenced by many internal and external factors. Overall, the individual GI microbiota composition appears to be rather stable but can be influenced by extreme shifts in environmental exposures. To date, there is no systematic literature review that examines the effects of extreme environmental conditions, such as strict isolation and confinement, on the GI microbiota. We conducted a systematic review to examine the effects of isolated and confined environments on the human GI microbiota. The literature search was conducted according to PRISMA criteria using PubMed, Web of Science and Cochrane Library. Relevant studies were identified based on exposure to isolated and confined environments, generally being also antigen-limited, for a minimum of 28 days and classified according to the microbiota analysis method (cultivation- or molecular based approaches) and the isolation habitat (space, space- or microgravity simulation such as MARS-500 or natural isolation such as Antarctica). Microbial shifts in abundance, alpha diversity and community structure in response to isolation were assessed. Regardless of the study habitat, inconsistent shifts in abundance of 40 different genera, mainly in the phylum Bacillota (formerly Firmicutes) were reported. Overall, the heterogeneity of studies was high. Reducing heterogeneity was neither possible by differentiating the microbiota analysis methods nor by subgrouping according to the isolation habitat. Alpha diversity evolved non-specifically, whereas the microbial community structure remained dissimilar despite partial convergence. The GI ecosystem returned to baseline levels following exposure, showing resilience irrespective of the experiment length. An isolated and confined environment has a considerable impact on the GI microbiota composition in terms of diversity and relative abundances of dominant taxa. However, due to a limited number of studies with rather small sample sizes, it is important to approach an in-depth conclusion with caution, and results should be considered as a preliminary trend. The risk of dysbiosis and associated diseases should be considered when planning future projects in extreme environments. https://www.crd.york.ac.uk/prospero/, identifier CRD42022357589.

Biomolecular condensates under extreme martian salt conditions.

Biomolecular condensates formed by liquid–liquid phase separation (LLPS) are considered one of the early compartmentalization strategies of cells, which still prevail today forming non-membraneous compartments in biological cells. Studies of the effect of high pressures, such as those encountered in the subsurface salt lakes of Mars or in the depths of the sub-seafloor on Earth, on biomolecular LLPS will contribute to questions of protocell formation under prebiotic conditions. We investigated the effects of extreme environmental conditions, focusing on highly aggressive Martian salts (perchlorate and sulfate) and high pressure, on the formation of biomolecular condensates of proteins. Our data show that the driving force for phase separation of proteins is not only sensitively dictated by their amino acid sequence but also strongly influenced by the type of salt and its concentration. At high salinity, as encountered in Martian soil and similar harsh environments on Earth, attractive short-range interactions, ion correlation effects, hydrophobic, and π-driven interactions can sustain LLPS for suitable polypeptide sequences. Our results also show that salts across the Hofmeister series have a differential effect on shifting the boundary of immiscibility that determines phase separation. In addition, we show that confinement mimicking cracks in sediments and subsurface saline water pools in the Antarctica or on Mars can dramatically stabilize liquid phase droplets, leading to an increase in the temperature and pressure stability of the droplet phase.

Influence of water absorption on mechanical properties and glass transition temperatures of polyamide6/hexagonal boron nitride composites

PurposeThe absorption of moisture/water can affect the mechanical and thermal properties of polymers and polymer composites as many polymers, mainly polyamide thermoplastics, are sensitive to environmental humidity and can absorb a large amount of moisture. This paper investigates the effect of water molecules' absorption on mechanical and thermal properties of polyamide6/hexagonal boron nitride (PA6/h-BN) composites.Design/methodology/approachThe PA6/h-BN composites were exposed to an open environment and water for 15 days to analyse the effect of humidity/water molecules' absorption on mechanical and thermal properties. The tensile strength, hardness and impact strength of materials were measured and compared. The scanning electron microscopy (SEM), x-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses were utilized to see the influence of water absorption on microstructure, crystallinity and glass transition temperatures.FindingsAfter exposing materials to an open environment and water, the tensile strength and hardness were found to decline, while improvement in impact strength was noticed. SEM characterization revealed the formation of voids/pockets in water-immersed materials. DSC analysis revealed the loss in glass transition temperatures, and XRD analysis revealed the loss in crystallinity of water-immersed materials.Originality/valueEnvironmental conditions vary according to the geographical areas, and it varies in many countries throughout the year. Polyamides are sensitive to the environmental humidity and can absorb a large amount of moisture from the environment. It becomes necessary to test these materials in their original working conditions, and sometimes it is mandatory to see the effects of extreme environmental conditions on a component. In this article, efforts have been made to investigate the influence of extreme humidity/water conditions on thermo-mechanical properties of PA6/h-BN composites.

Biomolecular Condensates under Extreme Martian Salt Conditions

Biomolecular condensates formed by liquid-liquid phase separation (LLPS) are considered one of the early compartmentalization strategies of cells, which still prevail today forming nonmembranous compartments in biological cells. Studies of the effect of high pressures, such as those encountered in the subsurface salt lakes of Mars or in the depths of the subseafloor on Earth, on biomolecular LLPS will contribute to questions of protocell formation under prebiotic conditions. We investigated the effects of extreme environmental conditions, focusing on highly aggressive Martian salts (perchlorate and sulfate) and high pressure, on the formation of biomolecular condensates of proteins. Our data show that the driving force for phase separation of proteins is not only sensitively dictated by their amino acid sequence but also strongly influenced by the type of salt and its concentration. At high salinity, as encountered in Martian soil and similar harsh environments on Earth, attractive short-range interactions, ion correlation effects, hydrophobic, and π-driven interactions can sustain LLPS for suitable polypeptide sequences. Our results also show that salts across the Hofmeister series have a differential effect on shifting the boundary of immiscibility that determines phase separation. In addition, we show that confinement mimicking cracks in sediments and subsurface saline water pools in the Antarctica or on Mars can dramatically stabilize liquid phase droplets, leading to an increase in the temperature and pressure stability of the droplet phase.

Germination responses of Lycium humile, an extreme halophytic Solanaceae: understanding its distribution in saline mudflats of the southern Puna

Although knowledge about halophytic Solanaceae is scarce, it is known that several species within genus Lycium tolerate salinity. Lycium humile grows in highly saline soils in mudflats near saline Andean lakes. This study evaluated the germination responses of L. humile under different scarification methods, photoperiods, temperatures and saline conditions and, simultaneously, tested seedling survival under different iso-osmotic conditions. Dormancy and germination were found to be regulated by interactions with different factors, with the highest germination percentages being obtained by immersion in sulfuric acid, with a temperature of 25 °C and a temperature regime of 5/25 °C, under which seeds were neutrally photoblastic. As osmotic potential of saline solutions decreased, germination also decreased drastically but the seedling survival percentage was higher than 30 % at 600 mM NaCl. No seeds germinated in any of the polyethylene glycol (PEG) solutions and no seedling survival was observed from -1.2 MPa PEG solutions. More than 90 % of seeds incubated in NaCl were able to recover germination after being transferred to distilled water, independently of NaCl treatments. We concluded that the effects of extreme environmental conditions on germination responses and seed tolerance to salinity may determine the occurrence and restricted distribution of L. humile.

Hybrid breeding in wheat: how shaping floral biology can offer new perspectives.

Hybrid breeding in wheat (Triticum aestivum L.) has the potential to deliver major yield increases. This is a requisite to guarantee food security for increasing population demands and to counterbalance the effects of extreme environmental conditions. Successful hybrid breeding in wheat relies on forced outcrossing while preventing self-pollination. To achieve this, research has been directed towards identifying and improving fertility control systems. To maximise cross-pollination and seed set, however, fertility control systems need to be complemented by breeding phenotypically distinct male and female lines. This review summarises existing and novel male sterility systems for wheat hybridisation. We also consider the genetic resources that can be used to alter wheat's floral development and spike morphology, with a focus on the genetic variation already available. Exploiting these resources can lead to enhanced outcrossing, a key requirement in the progress towards hybrid wheat breeding.

Effects of extreme environmental conditions on white‐tailed deer antlers

ABSTRACTAntler size and morphology is the resultant combination of deer age, nutrition, and genetics. Additionally, extreme environmental conditions can affect deer health, which may influence current and future antler metrics. Throughout the antler development season of 2012, the Nebraska, USA, white‐tailed deer (Odocoileus virginianus) herd experienced a combination of extreme environmental conditions including extreme drought and disease, which we hypothesized would negatively affect antler size and morphology. Our objectives were to evaluate whether 1) age‐specific antler metrics differed between deer stressed by an extreme environmental condition year compared with nonextreme condition years, and 2) subsequent age‐specific antler metrics of a cohort born during an extreme environmental condition year differed from those born during nonextreme condition years. We measured antler metrics on harvested white‐tailed deer from central Nebraska for an 8‐year period (2009–2016) that spanned the extreme environmental condition year. Over this same time period, we measured pedicle seal depth on naturally cast antlers. Some trends were apparent for specific antler metrics in particular age groups; but, overall, antler metrics measured from harvested deer were not consistently affected during the extreme environmental condition year. Conversely, pedicle seal depths responded to environmental stressors and were smaller during the extreme environmental condition year compared with nonextreme condition years. We found effects to persist for years following extreme environmental stress—antler metrics of the extreme environmental condition cohort were smaller compared with nonextreme years. These results suggest that stressors caused by extreme environmental conditions can affect deer health and be indexed using sensitive metrics taken on cast antlers. Furthermore, effects on antler metrics can persist, affecting subsequent antler expression for cohorts that experience extreme environmental conditions during their first year of life. © 2019 The Wildlife Society.

Mechanical performance of full scale steel-timber epoxy joints after exposure to extreme environmental conditions

The use of adhesive joints with bonded-in steel rods or plates is of considerable interest nowadays for both new large timber structures design and timber strengthening. Bonded-in joints offer some advantages: high stiffness, high strength, ductile behaviour in some cases, easiness of factory production and possibility of in situ realization. Their use in Service Classess 1 and 2 is possible but not in Service Class 3, due to the extreme conditions. While the effect of the environmental conditions on the wood is well known, their effect on epoxy glue and on the mechanical properties of full scale timber joints requires ad hoc tests. In order to verify the effects of extreme environmental conditions, on the durability of the epoxy resin and on the mechanical behaviour of full scale ordinary joints, different epoxy specimens and timber joints were exposed to various conditions and ageing cycles: immersion in water (demineralized and swimming pool water), high and low temperature treatments cycles, treatments at different temperatures and R.H. Epoxy specimens showed transformation only in the case of immersion in swimming pool water. Full scale timber joints showed a shear strength variation only due to the moisture content variation between 12% and 24%. Joints submerged in water showed a strength reduction higher than the one expected for the reached moisture content, demonstrating that extreme conditions affect not only the timber strength, but also the performance of the full joints.

An efficient design methodology for subsea manifold piping systems based on parametric studies

Subsea manifolds are widely used in the development of oil and gas fields to simplify the subsea system, minimise the number of subsea pipelines/risers and optimise the flow path in a piping system. The piping system is designed to satisfy the requirements for internal pressure, thermal loads, hydrostatic collapse and external operational loads under extreme environmental conditions. At present, however, there are no efficient and well-defined design procedures available that accurately predict the effects of extreme environmental conditions on pressure drop, total deformation, weight and erosion characteristics given varying design parameters considered throughout the piping system. Therefore, it is necessary to develop an new design procedure for subsea manifold piping systems with complicated shapes capable of sustaining erosion inside the piping system. The aim of this study is to develop a design procedure for subsea manifold piping systems based on a variety of parameters of influence under extreme environmental conditions, including high pressure and high temperature. A detailed numerical analysis of nonlinear finite element method and finite volume method is conducted to develop the proposed design procedure based on the results of parametric studies and generates some recommendations for the design of optimal subsea manifold piping configuration systems. The design procedure presented here will assist the design and analysis of subsea manifold piping systems.

Extreme climatic events in relation to global change and their impact on life histories

Abstract Extreme weather conditions occur at an increasing rate as evidenced by higher frequency of hurricanes and more extreme precipitation and temperature anomalies. Such extreme environmental conditions will have important implications for all living organisms through greater frequency of reproductive failure and reduced adult survival. We review examples of reproductive failure and reduced survival related to extreme weather conditions. Phenotypic plasticity may not be sufficient to allow adaptation to extreme weather for many animals. Theory predicts reduced reproductive effort as a response to increased stochasticity. We predict that patterns of natural selection will change towards truncation selection as environmental conditions become more extreme. Such changes in patterns of selection may facilitate adaptation to extreme events. However, effects of selection on reproductive effort are difficult to detect. We present a number of predictions for the effects of extreme weather conditions in need of empirical tests. Finally, we suggest a number of empirical reviews that could improve our ability to judge the effects of extreme environmental conditions on life history.

Events during Early Triassic recovery from the end-Permian extinction

The Palaeozoic–Mesozoic transition is characterized not only by the biggest Phanerozoic mass extinction, at the end of Permian, but also a prolonged period of recovery of the biota during the succeeding Early Triassic. The delayed recovery is generally attributed to the effects of extreme environmental conditions on the Early Triassic ecosystem. However, there has been very little study of the cause and mechanism of the environmental conditions that prevailed during the period of extinction and subsequent recovery. Research on the Permian–Triassic boundary and Lower Triassic, especially that on environmental events at the beginning of the Triassic in South China, indicates that the slowness of the recovery may be the result of three factors: (1) extreme environmental conditions that persisted through the transitional period and which were maintained by, for example, intermittent contemporary volcanism; (2) a passive evolutionary and ecologic strategy of the biota, in which r-selection taxa were dominant and K-selection forms insignificant; (3) an immature, poorly functioning ecosystem, which had difficulty in responding to and withstanding extreme environmental changes. According to data from South China, environmental changes were frequent during the Late Permian, and especially serious at the Permian–Triassic boundary. The Late Permian ecosystem was well structured and fully functioning as a result of a long period of steady development during the late Palaeozoic, and was capable of resisting general environmental changes. However, increasingly frequent and probably more extreme environmental events in the latest Permian may have led to a general collapse of this ecosystem and to the mass extinction at the end of the Permian. The Early Triassic ecosystem was immature, functioned poorly, and was unable to respond effectively to environmental changes, so that persisting extreme environmental conditions slowed ecosystem reconstruction considerably, and the recovery of the biota therefore took a relatively long time. The environmental events at the Permian–Triassic boundary might not be significantly different from those at other Phanerozoic transitions, but they consisted of a series of events that occurred at intervals during the transitional period.

The Hutton TLP: A Preliminary Design

Summary This paper presents a preliminary design for a tension leg platform (TLP) to develop the U.K. Hutton field. A platform (TLP) to develop the U.K. Hutton field. A structural design is described with results of performance analyses and model tests. Designs of the facilities, the tension leg system, the foundations, and the well systems also are included. Introduction The TLP that is being designed for the U. K. Hutton field will support all functional requirements for drilling, oil production, personnel accommodation, and ancillary production, personnel accommodation, and ancillary services. The Hutton field lies 144.8 km (90 miles) northeast of the Shetland Islands in 147-m (482-ft) water depth.The TLP is a floating structure connected to anchors fixed in the seabed by vertical mooring lines (tension legs) at each corner of the platform (Fig. 1). These vertical mooring lines virtually eliminate the vertical plane motions of heave, pitch, and roll, while the lateral movements in surge, sway, and yaw are compliantly restrained. Buoyancy is provided by the vertical columns and the horizontal pontoons connecting the bottoms of these columns. An excess of buoyancy greater than the platform weight keeps the mooring lines in tension for all platform weight keeps the mooring lines in tension for all weather and all loading conditions. Column height is sufficient to support the deck above the wave crest elevations for all tide and wave conditions when the TLP is fixed to the seabed foundations by the tension legs.The TLP is installed permanently in the sense that it can resist the effects of extreme environmental conditions and continue operations in the same manner as conventional fixed platforms. The fabrication, outfitting, hookup, and commissioning of the facilities can be completed in onshore fabrication yards and/or inshore completion sites. All components are designed for a minimum of 20 years' service life. Key components such as tension legs and well riser tensioners are simple and intrinsically reliable, have backups, and are replaceable for inspection and maintenance. Individual well risers connect each well to the TLP. These individually tensioned risers safely and reliably withstand the effects of extreme environmental conditions without the need to be disconnected.In the early 1970's, a team of Conoco engineers analyzed subsea production systems for deep water. As a result, they recommended that designs be developed to provide above-water platform space to accommodate provide above-water platform space to accommodate drilling and production facilities in deep water. The tension leg platform was recognized as a potential system with a cost that should be relatively insensitive to water depth. An intensive study concluded that this concept was feasible and could be designed to be reliable.As a consequence of these studies, another in-depth design study was carried out in 1977 on the application of a TLP for development of the Hutton field. In addition, the application of a semisubmersible early production system was investigated. Following a production system was investigated. Following a comprehensive investigation of alternative development methods, including a steel jacket structure, the team recommended the use of a TLP to develop Hutton. The development plan calls for nine wells to be drilled with a plan calls for nine wells to be drilled with a semisubmersible drilling rig before TLP installation. The remaining wells will be drilled from the TLP while previously completed wells are being produced.The development of new technology is greatly enhanced by application to a specific, real project. TLP development studies prior to the Hutton field design study necessarily included numerous alternative solutions. For example, the TLP could be anchored by a gravity base, driven piles, or drilled and grouted piles. Specific environmental conditions, water depth, and soil characteristics can minimize the consideration of certain alternatives before detailed and costly studies are made. The most feasible or preferred solution can be selected early and designers can proceed directly to detailed engineering studies. Vendor support is obtained more easily for a specific real project for which there is a visible and timely application of their effort.This paper describes a preliminary design for the Hutton TLP. JPT P. 208