Whole-genome sequencing highlights conservative genomic strategies of a stress-tolerant, long-lived scleractinian coral, Porites australiensis Vaughan, 1918

Massive corals of the genus Porites, common, keystone reef builders in the Indo-Pacific Ocean, are distinguished by their relative stress tolerance and longevity. In order to identify genetic bases of these attributes, we sequenced the complete genome of a massive coral, Porites australiensis. We developed a genome assembly and gene models of comparable quality to those of other coral genomes. Proteome analysis identified sixty Porites skeletal matrix protein genes, all of which show significant similarities to genes from other corals and even to those from a sea anemone, which has no skeleton. Nonetheless, 30% of its skeletal matrix proteins were unique to Porites, and were not present in the skeletons of other corals. Comparative genomic analyses showed that genes widely conserved among other organisms are selectively expanded in Porites. Specifically, comparisons of transcriptomic responses of P. australiensis and Acropora digitifera, a stress-sensitive coral, reveal significant differences in regard to genes that respond to increased water temperature, and some of the genes expanded exclusively in Porites may account for the different thermal tolerances of these corals. Taken together, widely shared genes may have given rise to unique biological characteristics of Porites, massive skeletons and stress tolerance.

Relative Stress Analysis of Gas Turbine Blade for Various Alloying Materials

Gas turbines provide a reliable and efficient production of power in both pilot power plants and aircraft propulsion. The operating cost of the modern gas turbines is greatly influenced by the durability of hot section components. To cope up with the increasing temperature, there has been an evolution of new generation blade materials. At elevated temperature conditions, thermal stress and resulting deformations can affect the power developed and efficiency. In this paper a finite element simulation has been made on a fixed blade profile to explore various factors affecting the turbine blade. Variety of existing and new generation materials have been considered a under a boundary condition of constant high pressure and high Operating temperature was varied between 1000°C-1400°C. The development of stress and deformation along with the heat flux have been studied for finding the most effective manufacturing alloy for gas turbines.

Thermoresistance in black yeasts is associated with halosensitivity and HPP tolerance, but not with UV tolerance or sanitizer tolerance

Black yeasts can survive extreme conditions in food production owing to their polyextremotolerant character. However, significant strain-to-strain variation in black yeast thermoresistance has been observed. In this study, we assessed the variability in tolerance to nonthermal interventions among a collection of food-related black yeast strains. Variation in tolerance to UV light treatment, high pressure processing, sanitizers, and osmotic pressure was observed within each species. The two strains previously shown to possess high thermotolerance, Exophiala phaeomuriformis FSL-E2-0572 and Exophiala dermatitidis YB-734, were also the most HPP tolerant, but were the least halotolerant. Meanwhile, Aureobasidium pullulans FSL-E2-0290 was the most UV and sanitizer tolerant, but had been shown to have relatively low thermoresistance. Fisher’s exact tests showed that thermoresistance in black yeasts was associated with HPP tolerance and inversely with halotolerance, but no association was found with UV tolerance or sanitizer tolerance. Collectively, the relative stress tolerance among strains varied across interventions. Given this variation, a broad range of different food products are susceptible to black yeast spoilage. Additionally, different strains should be selected in challenge studies specific to the intervention. (1312/2000 characters)

Vertical divergence of the atmospheric momentum flux near the sea surface at a coastal site

Motivated by previous studies, we examine the underestimation of the sea-surface stress due to the stress divergence between the surface and the atmospheric observational level. We analyze flux measurements collected over a six-year period at a coastal tower in the Baltic Sea encompassing a wide range of fetch values. Results are posed in terms of the vertical divergence of the stress scaled by the stress at the lowest observational level. The magnitude of this relative stress divergence increases with increasing stability and decreases with increasing instability, possibly partly due to the impact of stability on the boundary-layer depth. The magnitude of the relative stress divergence increases modestly with decreasing wave age. The divergence of the heat flux is not well correlated with the divergence of the momentum flux evidently due to the greater influence of advection on the temperature. Needed improvement of the conceptual framework and needed additional measurements are noted.

Effect of Sheets’ Thickness and Rivet Geometry on Mechanical Properties of Orbital Riveted Aluminium Joints: Experimental and Numerical Analysis

Orbital riveting is an innovative joining technology used in various industrial fields. Despite its diffusion in recent years, it has not been accompanied by an equivalent interest from the scientific community, which has neglected the aspects of process optimization and joint performance. In this experimental/numerical study, six different configurations of orbital riveted joints were realised and tested to determine the effects of sheet thickness and rivet geometry on the mechanical properties of the joints and their failure modes. The results showed that the configuration of the joint significantly affects both its resistance and fracture mechanism. Moreover, it was possible to identify a transition between different failure modes by changing the rivet diameter. A non-optimal joint geometry favours a premature fracture at very low load (i.e., S9A21 batch with net tension fracture). The highest mechanical resistance was found in the S8A15 batch, which experienced unbuttoning failure. In order to better correlate the joint geometry with the mechanical behaviour and the relative stress distribution, a simplified numerical FEM was validated with the experimental results.

Between Catastrophes: God, Nature and Humanity

Critical responses to the pandemic have divided between the need to control and defeat it and fears of a new medicalisation of human existence. In the short-term the first response is right, but in the long-term the second. The ideological division on this issue on the left roughly correlates with a relative stress on the power of the market on the one hand or the power of the state on the other. But these are two halves of the same picture: the mechanisation of human life and the artificial rendering of the natural scarce and threatening. The tendencies that give rise to pandemics and those which exult in increasing total control are the same. Resistance can only come from a resistance to liberal mechanising as such. This requires the double sense that we are as spirits located within nature and yet as spirits transcend nature, which the theological doctrine of creation upholds. The challenge is to create a new global consensus and shared metaphysical politics around this legacy.

Elevated CO2 and temperature effect on growth and physiology of Chenopodium album L.

A study was conducted in open top chambers (OTCs) to understand the effect of elevated temperature (ambient+2±0.5oC) and elevated CO2 (550±50 ppm) individually and in combination on Chenopodium album. Impact of the climate variables was studied in terms of selected plant attributes, viz., leaf area, RGR etc. Study showed that elevated temperature as well as elevated CO2 individually and in combination had significant positive effect on growth and development, rate of photosynthesis, and water use efficiency of the Chenopodium album. Rate of transpiration and stomatal conductance increased marginally in plants grown at elevated temperature, but a marked decrease was evident at elevated CO2 individually and in combination with elevated temperature as compared that in plants grown in ambient conditions in the Chenopodium album. No significant changes were observed in relative water content and relative stress injury under any of the Chenopodium album. Treatments changes were evident with respect to the activity of antioxidant enzymes and nitrate reductase and peptide banding pattern using SDS-PAGE. This research was conducted to examine the joint effects of increased temperature and elevated CO2 level onChenopodium album (C3 weed). Results from this experiment suggested that rising (CO2) could alter physiochemical response for growth and development of Chenopodium album and it is well defined competitors with different crops in current changing climate conditions.

Hot Deformation Behavior of a Ni-Based Superalloy with Suppressed Precipitation

Inconel®718 is a well-known nickel-based super-alloy used for high-temperature applications after thermomechanical processes followed by heat treatments. This work describes the evolution of the microstructure and the stresses during hot deformation of a prototype alloy named IN718WP produced by powder metallurgy with similar chemical composition to the matrix of Inconel®718. Compression tests were performed by the thermomechanical simulator Gleeble®3800 in a temperature range from 900 to 1025 °C, and strain rates scaled from 0.001 to 10 s−1. Flow curves of IN718WP showed similar features to those of Inconel®718. The relative stress softening of the IN718WP was comparable to standard alloy Inconel®718 for the highest strain rates. Large stress softening at low strain rates may be related to two phenomena: the fast recrystallization rate, and the coarsening of micropores driven by diffusion. Dynamic recrystallization grade and grain size were quantified using metallography. The recrystallization grade increased as the strain rate decreased, although showed less dependency on the temperature. Dynamic recrystallization occurred after the formation of deformation bands at strain rates above 0.1 s−1 and after the formation of subgrains when deforming at low strain rates. Recrystallized grains had a large number of sigma 3 boundaries, and their percentage increased with strain rate and temperature. The calculated apparent activation energy and strain rate exponent value were similar to those found for Inconel®718 when deforming above the solvus temperature.

Experimental Study on the Troperty Degradation and Failure Mech- Anism of Weakly Cemented Sandstone Under Dry-wet Cycles

Taking the weakly cemented sandstone of Erdos, China, as the research object, the evolution law between the relative stress of weakly cemented sandstone and the multiparameters of the acoustic emission under different dry-wet cycles was explored, and the critical failure identification mode of weakly cemented sandstone under dry-wet cycles was established. The results show that as the number of dry-wet cycles increases, the wave velocity loss rate gradually increases. Overall, the longitudinal wave loss rate is larger than the shear wave loss rate, indicating that the longitudinal wave is more sensitive to the degradation of weakly cemented sandstone. With an increase in the number of dry-wet cycles, the fracture crack is mainly caused by the main crack penetration failure, and the secondary crack is significantly reduced. The fractal dimension decreases with an increase in the dry-wet cycles and reaches its maximum at 0 dry-wet cycles, which means that 0 dry-wet cycles witness the most complex morphology of fractures within the weakly cemented sandstone. This finding indicates that the dry-wet cycle inhibits the generation and expansion of fractures. The event rate appears to be close to 0 before the rupture, and then the platform oscillates, followed by a sudden increase. The acoustic emission b-value is relatively high during the initial stage and then decreases, which is the initial damage process. The elastoplastic phase rises again, the peak stage decreases rapidly, and the weakly cemented sandstone undergoes unstable damage. The change in the acoustic emission entropy value is exactly the opposite of the b-value change law. When the weakly cemented sandstone reaches the critical failure state under different dry-wet cycles, the relative stress value is 95%. The test results provide new methods and a basis for the damage evolution mechanism and fracture prediction of weakly cemented sandstone under dry-wet cycles.

Mechanical Evaluation of Collapse Risk for Osteonecrosis of Femoral Head Post-Medical Treatment

Background: Early-stage osteonecrosis of the femoral head can progressively induce the bone collapse and the accuracy of the collapse risk evaluation is limited. This study aims to propose a potential collapse indicator by biomechanical evaluating the treatment effectiveness. Methods: Six patient-specific models pre- (initial presentation) and post- medical treatment were established and elastic properties of the bone were assigned with a function of spatial-variant Hounsfield unit values. Morphological and mechanical analyses were compared between pre- and post-treatment models. Results: In the morphological study, four cases show the reduced ratio of low-density necrotic volume, but not consistent with one-year follow-up results. In the mechanical analysis, the equivalent stress variation near the Ward triangle shows consistency in the one-year outcome. Moreover, a parameter - relative stress index, the ratio between the mean volume stress index and the mean volume equivalent stress, is proposed. A smaller value of the relative stress index indicates stronger bone compressive strength and its variation is consistent with the follow-up results. Conclusions: Results implicate that to evaluate the effectiveness of medical treatments, the morphologic analysis should be considered but the mechanical capability and the loading transfer path through the necrotic and viable bone play a more important role.