Facing extremes: archaeal surface-layer (glyco)proteins

Microbiology ◽  
2003 ◽  
Vol 149 (12) ◽  
pp. 3347-3351 ◽  
Author(s):  
Jerry Eichler
Keyword(s):  
Surface Layer ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Protein Biosynthesis ◽  
Extreme Environments ◽  
Archaeal Protein ◽  
The Face ◽  
Micro Organisms ◽  
Physical Challenges ◽  
Insight Into

Archaea are best known in their capacities as extremophiles, i.e. micro-organisms able to thrive in some of the most drastic environments on Earth. The protein-based surface layer that envelopes many archaeal strains must thus correctly assemble and maintain its structural integrity in the face of the physical challenges associated with, for instance, life in high salinity, at elevated temperatures or in acidic surroundings. Study of archaeal surface-layer (glyco)proteins has thus offered insight into the strategies employed by these proteins to survive direct contact with extreme environments, yet has also served to elucidate other aspects of archaeal protein biosynthesis, including glycosylation, lipid modification and protein export. In this mini-review, recent advances in the study of archaeal surface-layer (glyco)proteins are discussed.

The Relationship between Seeker and Spiritual Guide as portrayed in contemporary Western Sufi Autobiographies

2011 ◽  
Vol 5 (2) ◽  
pp. 297-332
Author(s):  
Kate Zebiri
Keyword(s):  
Life Writing ◽  
New Age ◽  
The Self ◽  
Individual Autonomy ◽  
Religious Authority ◽  
The Face ◽  
The Relationship ◽  
Insight Into ◽  
Continuity And Discontinuity

This article aims to explore the Shaykh-mur?d (disciple) or teacher-pupil relationship as portrayed in Western Sufi life writing in recent decades, observing elements of continuity and discontinuity with classical Sufism. Additionally, it traces the influence on the texts of certain developments in religiosity in contemporary Western societies, especially New Age understandings of religious authority. Studying these works will provide an insight into the diversity of expressions of contemporary Sufism, while shedding light on a phenomenon which seems to fly in the face of contemporary social and religious trends which deemphasize external authority and promote the authority of the self or individual autonomy.

scholarly journals Ecotoxicological Assessment of Microplastics in Freshwater Sources—A Review

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 56
Author(s):  
Martina Miloloža ◽  
Dajana Kučić Grgić ◽  
Tomislav Bolanča ◽  
Šime Ukić ◽  
Matija Cvetnić ◽  
...  
Keyword(s):  
Complex Problem ◽  
Living Standards ◽  
Way Of Life ◽  
Inorganic Pollutants ◽  
Ecotoxicological Assessment ◽  
Characterization Methods ◽  
Special Concern ◽  
Micro Organisms ◽  
Insight Into

High living standards and a comfortable modern way of life are related to an increased usage of various plastic products, yielding eventually the generation of an increased amount of plastic debris in the environment. A special concern is on microplastics (MPs), recently classified as contaminants of emerging concern (CECs). This review focuses on MPs’ adverse effects on the environment based on their bioactivity. Hence, the main topic covered is MPs’ ecotoxicity on various aquatic (micro)organisms such as bacteria, algae, daphnids, and fish. The cumulative toxic effects caused by MPs and adsorbed organic/inorganic pollutants are presented and critically discussed. Since MPs’ bioactivity, including ecotoxicity, is strongly influenced by their properties (e.g., types, size, shapes), the most common classification of MPs types present in freshwater are provided, along with their main characteristics. The review includes also the sources of MPs discharge in the environment and the currently available characterization methods for monitoring MPs, including identification and quantification, to obtain a broader insight into the complex problem caused by the presence of MPs in the environment.

scholarly journals Stochasticity and heterogeneity in host–vector models

2007 ◽  
Vol 4 (16) ◽  
pp. 851-863 ◽  
Author(s):  
Alun L Lloyd ◽  
Ji Zhang ◽  
A.Morgan Root
Keyword(s):  
Branching Process ◽  
Moment Equations ◽  
Demographic Stochasticity ◽  
The Face ◽  
Process Methodology ◽  
The Impact ◽  
Malaria Model ◽  
Heterogeneous Transmission ◽  
Insight Into ◽  
Stochastic Extinction

Demographic stochasticity and heterogeneity in transmission of infection can affect the dynamics of host–vector disease systems in important ways. We discuss the use of analytic techniques to assess the impact of demographic stochasticity in both well-mixed and heterogeneous settings. Disease invasion probabilities can be calculated using branching process methodology. We review the use of this theory for host–vector infections and examine its use in the face of heterogeneous transmission. Situations in which there is a marked asymmetry in transmission between host and vector are seen to be of particular interest. For endemic infections, stochasticity leads to variation in prevalence about the endemic level. If these fluctuations are large enough, disease extinction can occur via endemic fade-out. We develop moment equations that quantify the impact of stochasticity, providing insight into the likelihood of stochastic extinction. We frame our discussion in terms of the simple Ross malaria model, but discuss extensions to more realistic host–vector models.

Design and topological optimization of rear pressure bulkhead for a typical aircraft

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Marshal Thakran ◽  
Meenakshi ◽  
Jitender Sharma ◽  
Charles Gilbert Martin
Keyword(s):  
Numerical Analysis ◽  
Significant Influence ◽  
Design Methodology ◽  
Structural Integrity ◽  
Topological Optimization ◽  
Content Type ◽  
Iterative Design ◽  
Practical Implications ◽  
Insight Into ◽  
Selection Of

Purpose The purpose of this paper is to evaluate the model of a rear pressure bulkhead with different design optimizations to meet the pressurized cabin requirements of an aircraft. Design/methodology/approach This paper presents the results of the static analysis of a dome-shaped rear pressure bulkhead model designed in Catia-v5. Numerical analysis of model meshed in hyper-mesh and solved using Opti-Struct for iterative design optimizations. Findings All the iterative models are analyzed at 9 Psi. Rear pressure bulkhead designed with L-section stringer shows better results than the model optimized with T-section stringer for the same thickness. The model optimized with L-shaped stinger also reduces the weight of the bulkhead without affecting the structural integrity. Practical implications It has been concluded in this paper that the selection of specific shapes of the stringers shows a significant influence on weight reduction. Originality/value This paper provides a topical, technical insight into the design and development of a rear pressure bulkhead. It also outlines the future development of dome-shaped rear pressure bulkhead.

scholarly journals Recent advancements in shape optimization of aero spiked high speed re-entry vehicle using CFD

2018 ◽  
Vol 172 ◽  
pp. 01007
Author(s):  
Harish Panjagala ◽  
E L N Rohit Madhukar ◽  
I Ravi Kiran
Keyword(s):  
High Speed ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Thermal Protection ◽  
Space Vehicle ◽  
Protection Systems ◽  
Ultimate Outcome ◽  
Increasing Demand ◽  
Space Activities ◽  
Intense Heat

Due to increasing demand of High Speed Re-entry vehicles for Space activities within the world, a serious issue associated with the method of deceleration down a vehicle is by the intense heat generated because of development of stronger shocks at the nose. The price of thermal protection systems (TPS) to cut back the warmth generated by the return vehicles is extremely high. In this paper, the ultimate outcome is to cut back the aero heating which is achieved by introducing a spike at frontal region of the nose. Additionally, this spike avoids the deterioration and preserves the structural integrity of space vehicle over elevated temperatures. Further, four totally different geometries of tip specifically Blunt, Slender, Snap and Pan for the aerospike has been introduced and their impact on performance is evaluated and compared with the vehicle having TPS. Hence, usage of aerospike in return vehicles is the most successful and economical over different protection system.

scholarly journals Development of Creep-Resistant, Alumina-Forming Ferrous Alloys for High-Temperature Structural Use

2018 ◽  
Author(s):  
Y. Yamamoto ◽  
M. P. Brady ◽  
G. Muralidharan ◽  
B. A. Pint ◽  
P. J. Maziasz ◽  
...  
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Extreme Environments ◽  
Alloy Design ◽  
Austenitic Steels ◽  
Strength Development ◽  
Second Phase ◽  
Ferrous Alloys ◽  
Steel Alloys ◽  
Structural Applications

This paper overviews recent advances in developing novel alloy design concepts of creep-resistant, alumina-forming Fe-base alloys, including both ferritic and austenitic steels, for high-temperature structural applications in fossil-fired power generation systems. Protective, external alumina-scales offer improved oxidation resistance compared to chromia-scales in steam-containing environments at elevated temperatures. Alloy design utilizes computational thermodynamic tools with compositional guidelines based on experimental results accumulated in the last decade, along with design and control of the second-phase precipitates to maximize high-temperature strengths. The alloys developed to date, including ferritic (Fe-Cr-Al-Nb-W base) and austenitic (Fe-Cr-Ni-Al-Nb base) alloys, successfully incorporated the balanced properties of steam/water vapor-oxidation and/or ash-corrosion resistance and improved creep strength. Development of cast alumina-forming austenitic (AFA) stainless steel alloys is also in progress with successful improvement of higher temperature capability targeting up to ∼1100°C. Current alloy design approach and developmental efforts with guidance of computational tools were found to be beneficial for further development of the new heat resistant steel alloys for various extreme environments.

scholarly journals Analysis of Broadband Antenna Radiation Pulses

2018 ◽  
Vol 22 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Aleksander Cherenkov ◽  
Taras Hutsol ◽  
Igor Garasymchuk ◽  
Jurii Pancyr ◽  
Dmytro Terenov ◽  
...  
Keyword(s):  
Protein Biosynthesis ◽  
Biological Effects ◽  
Pulse Repetition Frequency ◽  
Ultrastructural Changes ◽  
Broadband Antenna ◽  
Resonant Character ◽  
Growth Changes ◽  
Operation Cycle ◽  
Micro Organisms

AbstractElectromagnetic energy can alter metabolic and biosynthetic processes and under certain parameters of pulsed EMF it can change pulse repetition frequency, operation cycle, power, exposure, as well as it can slow down and inhibit cell growth. MW irradiation range of RNA and DNA – containing virus reduces their infectivity. Inhibition of bacterial cultures growth, changes in phagocytic activity of protein biosynthesis, ultrastructural changes in the cells when exposed to EMF EHF. It was found in experiments with micro-organisms that biological effects of EMF on microorganisms wore a resonant character. One of the basic mechanisms of inhibitory action of EHF radiation on harmful microorganisms is the role of membranes in biological reactions of microorganisms on the EMR.

scholarly journals Preference Falsification Revisited: How Psychological Science Can Offer Insight into Motivated Belief Misrepresentation and Collective Misunderstanding

2021 ◽  
Author(s):  
Jacob Elder ◽  
Yrian Derreumaux;Derreumaux ◽  
Brent Hughes
Keyword(s):  
Social Dynamics ◽  
Theoretical Framework ◽  
Political Polarization ◽  
Social Connections ◽  
Future Research ◽  
Group Norms ◽  
Political Climate ◽  
Psychological Science ◽  
The Face ◽  
Insight Into

Throughout life, people sometimes lie to curry favor or mitigate disharmony with others, a tendency that may be exacerbated under moments of elevated tension. This phenomenon is captured by the economic theoretical framework of Preference Falsification, which describes why people misrepresent their beliefs in the face of social pressures, and how misrepresentation accumulates to broader misunderstandings that can fuel political polarization. We describe why the current political climate may foster motivations to misrepresent beliefs, as individuals are increasingly siloed into like-minded communities with strong pressures to conform to group norms. Next, we adopt a psychological lens to understand and integrate three motivations that underlie individual misrepresentation – relating to an individual’s intrinsic preference, their reputational concern, and their desire for expression – and describe how individual acts of misrepresentation can propagate across social connections to establish misrepresented beliefs as public consensus. Finally, we outline inroads for examining Preference Falsification using psychological methods that may be uniquely suited to elucidate the different social dynamics and issues that elicit this behavior, with the goal of spurring future research. Ultimately, we argue that fostering a more ideologically pluralistic and socially interconnected society may offer one route to reducing misrepresentation and collective misunderstanding, and thereby attenuate polarization and intergroup antipathy.

Unique Archaeal Small RNAs

2018 ◽  
Vol 52 (1) ◽  
pp. 465-487 ◽  
Author(s):  
José Vicente Gomes-Filho ◽  
Michael Daume ◽  
Lennart Randau
Keyword(s):  
Noncoding Rna ◽  
Genome Rearrangement ◽  
Rna Binding ◽  
Elevated Temperatures ◽  
Rna Binding Proteins ◽  
Current Knowledge ◽  
Extreme Environments ◽  
Noncoding Rnas ◽  
Hyperthermophilic Archaea ◽  
Rna Modification

Advances in genome-wide sequence technologies allow for detailed insights into the complexity of RNA landscapes of organisms from all three domains of life. Recent analyses of archaeal transcriptomes identified interaction and regulation networks of noncoding RNAs in this understudied domain. Here, we review current knowledge of small, noncoding RNAs with important functions for the archaeal lifestyle, which often requires adaptation to extreme environments. One focus is RNA metabolism at elevated temperatures in hyperthermophilic archaea, which reveals elevated amounts of RNA-guided RNA modification and virus defense strategies. Genome rearrangement events result in unique fragmentation patterns of noncoding RNA genes that require elaborate maturation pathways to yield functional transcripts. RNA-binding proteins, e.g., L7Ae and LSm, are important for many posttranscriptional control functions of RNA molecules in archaeal cells. We also discuss recent insights into the regulatory potential of their noncoding RNA partners.

Changing minds about climate change: a pervasive role for domain-general metacognition

2021 ◽  
Author(s):  
Manos Tsakiris ◽  
Neza Vehar ◽  
Stephen M Fleming ◽  
Sophie De Beukelaer ◽  
Max Rollwage
Keyword(s):  
Climate Change ◽  
Climate Science ◽  
Social Effects ◽  
Negative Evidence ◽  
Prior Beliefs ◽  
Domain Specific ◽  
The Face ◽  
Metacognitive Abilities ◽  
Insight Into

Updating one’s beliefs about the causes and effects of climate change is crucial for altering attitudes and behaviours. Importantly, metacognitive abilities - insight into the (in)correctness of one’s beliefs- play a key role in the formation of polarized beliefs. We investigated the role of domain-general and domain-specific metacognition in updating prior beliefs about climate change across the spectrum of climate change scepticism. We also considered the role of how climate science is communicated in the form of textual or visuo-textual presentations. We show that climate change scepticism is associated with differences in domain-general as well as domain-specific metacognitive abilities. Moreover, domain-general metacognitive sensitivity influenced belief updating in an asymmetric way : lower domain-general metacognition decreased the updating of prior beliefs, especially in the face of negative evidence. Our findings highlight the role of metacognitive failures in revising erroneous beliefs about climate change and point to their adverse social effects.

Sign in / Sign up

Export Citation Format

Share Document