Slow Growth Rate Research Articles

Rapid nucleation and growth of tetrafluoroethane hydrate enhanced by bubble and gas cycling

The application of hydrate technology is predominantly limited by the rapid nucleation and stable formation of hydrates, which could be promoted by the disturbance of bubbles. In this study, the effect of bubble generation and different bubble sizes on the nucleation and growth characteristics of R134a hydrates were investigated. The impact of three methods (depressurization-induced R134a vaporization, depressurization combined with stirring and gas cycling bubbling) of bubble effect and size on the nucleation, growth characteristics, and stability of R134a hydrate formation were explored. The research results indicate that utilizing only the depressurization method to induce R134a vaporization and bubble formation leads to a gas consumption rate of 19.6 mmol/min, which is 868 times higher than that in a pure water system. Furthermore, refining bubble size through stirring under depressurization conditions further augments the gas conversion rate by 8.6 %, and the optimal temperature for R134a hydrate formation is identified to be as low as 4 °C. Importantly, utilizing gas cycling as a means to generate bubbles enables uniform and rapid nucleation and growth of hydrates. Within a short 10 min, R134a hydrates was rapidly and stably formed, achieving a formation rate 35 times faster compared to the boiling-condensation method. In comparison to stirring-depressurization, the gas cycling method further increases the gas consumption rate by 10 %. The drawback of slow nucleation and growth rates in hydrates, as well as the need to enhance their stability, is addressed by the gas cycling method.

On-target, dual aminopeptidase inhibition provides cross-species antimalarial activity.

To combat the global burden of malaria, development of new drugs to replace or complement current therapies is urgently required. Here, we show that the compound MMV1557817 is a selective, nanomolar inhibitor of both Plasmodium falciparum and Plasmodium vivax aminopeptidases M1 and M17, leading to inhibition of end-stage hemoglobin digestion in asexual parasites. MMV1557817 can kill sexual-stage P. falciparum, is active against murine malaria, and does not show any shift in activity against a panel of parasites resistant to other antimalarials. MMV1557817-resistant P. falciparum exhibited a slow growth rate that was quickly outcompeted by wild-type parasites and were sensitized to the current clinical drug, artemisinin. Overall, these results confirm MMV1557817 as a lead compound for further drug development and highlights the potential of dual inhibition of M1 and M17 as an effective multi-species drug-targeting strategy.IMPORTANCEEach year, malaria infects approximately 240 million people and causes over 600,000 deaths, mostly in children under 5 years of age. For the past decade, artemisinin-based combination therapies have been recommended by the World Health Organization as the standard malaria treatment worldwide. Their widespread use has led to the development of artemisinin resistance in the form of delayed parasite clearance, alongside the rise of partner drug resistance. There is an urgent need to develop and deploy new antimalarial agents with novel targets and mechanisms of action. Here, we report a new and potent antimalarial compound, known as MMV1557817, and show that it targets multiple stages of the malaria parasite lifecycle, is active in a preliminary mouse malaria model, and has a novel mechanism of action. Excitingly, resistance to MMV15578117 appears to be self-limiting, suggesting that development of the compound may provide a new class of antimalarial.

Rational construction of genome-minimized Streptomyces host for the expression of secondary metabolite gene clusters

Streptomyces offer a wealth of naturally occurring compounds with diverse structures, many of which possess significant pharmaceutical values. However, new product exploration and increased yield of specific compounds in Streptomyces have been technically challenging due to their slow growth rate, complex culture conditions and intricate genetic backgrounds. In this study, we screened dozens of Streptomyces strains inhabiting in a plant rhizosphere for fast-growing candidates, and further employed CRISPR/Cas-based engineering techniques for stepwise refinement of a particular strain, Streptomyces sp. A-14 that harbors a 7.47 Mb genome. After strategic removal of nonessential genomic regions and most gene clusters, we reduced its genome size to 6.13 Mb, while preserving its growth rate to the greatest extent. We further demonstrated that cleaner metabolic background of this engineered strain was well suited for the expression and characterization of heterologous gene clusters, including the biosynthetic pathways of actinorhodin and polycyclic tetramate macrolactams. Moreover, this streamlined genome is anticipated to facilitate directing the metabolic flux towards the production of desired compounds and increasing their yields.

Interfacial Reactions between Sn-Based Solders and n-Type Bi2(Te,Se)3 Thermoelectric Material.

This study investigated the interfacial reactions between n-type Bi2(Te,Se)3 thermoelectric material, characterized by a highly-oriented (110) plane, and pure Sn and Sn-3.0Ag-0.5Cu (wt.%) solders, respectively. At 250 °C, the liquid-state Sn/Bi2(Te,Se)3 reactions resulted in the formation of both SnTe and BiTe phases, with Bi-rich particles dispersed within the SnTe phase. The growth of the SnTe phase exhibited diffusion-controlled parabolic behavior over time. In contrast, the growth rate was considerably slower compared to that observed with p-type (Bi,Sb)2Te3. Solid-state Sn/Bi2(Te,Se)3 reactions conducted between 160 °C and 200 °C exhibited similar interfacial microstructures. The SnTe phase remained the primary reaction product, embedded with tiny Bi-rich particles, revealing a diffusion-controlled growth. However, the BiTe layer had no significant growth. Further investigation into growth kinetics of intermetallic compounds and microstructural evolution was conducted to elucidate the reaction mechanism. The slower growth rates in Bi2(Te,Se)3, compared to the reactions with (Bi,Sb)2Te3, could be attributed to the strong suppression effect of Se on SnTe growth. Additionally, the interfacial reactions of Bi2(Te,Se)3 with Sn-3.0Ag-0.5Cu were also examined, showing similar growth behavior to those observed with Sn solder. Notably, compared with Ag, Cu tends to diffuse towards the interfacial reaction phases, resulting in a high Cu solubility within the SnTe phase.

PSI-8 Impact of feeding level on boars from selection to entering the boar stud on trainability and growth measurements

Abstract The objective of this study was to determine if restricting feed in boars at selection impacts growth of boars or training for semen collection. Duroc boars (n = 25) randomly allotted at 6 mo of age to receive one of two levels of restricted feeding (1.8 kg/d, n = 12 or 2.72 kg/d, n = 13) of a corn-soybean meal-based diet formulated to meet NRC (2012) requirements. Diets were fed for 9 wk before training for semen collection where body weight (BW), body condition score (BCS), flank-flank tape measurements, Knauer sow caliper, loin muscle depth, backfat depth, and scrotal width and length were collected every 3 wk. Training for semen collection was conducted 5 d/wk for 2 wk. Boars were given 10 min in the collection pen to successfully mount the dummy and start collection each training session. Training was scored on a scale of 1-5, 1 = no interest and 5 = successful collection. After three successful collections in a row, boars were considered fully trained. All boars had their first production collection on wk 12. Data were analyzed using PROC MIXED and PROC FREQ chi-square in SAS 9.4 with boar serving as experimental unit. Weeks were analyzed individually and overall changes were evaluated. Significance was determined at P < 0.05 and a trend was observed at 0.05 < P ≤ 0.10. Boars fed 2.72 kg/d had increased BW on wk 9 (P < 0.05) and wk 12 (163.6 kg vs 149.8 kg, SE = 2.17; P < 0.001), increased BW gain wk 1-9 (P < 0.01), wk 9-12 (P < 0.001), and overall (49.8 kg vs 34.4 kg, SE = 1.60; P < 0.0001). The 2.72 kg/d boars also had increased backfat depth on wk 9 (P < 0.01) and wk 12 (8.4 mm vs 7.5 mm, SE = 0.17; P < 0.001), larger caliper scores on wk 12 (P < 0.01), greater flank-flank distance on wk 9 (P < 0.01), and increased BCS on wk 12 (3.2 vs 2.7, SE = 0.14; P < 0.01). No differences were observed for loin muscle depth, or scrotal width and length. Feeding level did not affect trainability with approximately 92% of boars being trained at the end of the two-week period in both feeding levels. Boars fed 2.72 kg/d had increased semen volume (128 mL vs 81 mL, SE = 12.1; P < 0.01) on their first production collection on wk 12 with no effects on other semen quality parameters. Overall, feeding boars 1.8 kg/d for 12 weeks following selection resulted in lower body weight and composition measures indicating limit feeding boars at selection could be used to slow growth rates, potentially decreasing structural issues, and increasing longevity of growing boars in the boar stud, with no effects on training for semen collection. Future research is needed to investigate the long-term impacts of the degree of limit feeding growing boars following selection on lifetime semen quality and quantity. Keywords boar, management, nutrition

50 Feeding a multi-carbohydrase improves mortality, morbidity and variability of growing pigs fed varying levels of dried distiller’s grains with solubles

Abstract The objective was to determine the effects of Rovabio Advance 10 P, a multi-carbohydrase, on growth performance, mortality, and morbidity of growing pigs fed 15% or 35% dried distiller’s grains with solubles (DDGS). In the trial, 1,220 DNA pigs were fed from 32 kg to 134 kg body weight (BW). Four diets were fed: 15% DDGS (LO), 15% DDGS with Rovabio Advance (LO+), 35% DDGS (HI), and 35% DDGS with Rovabio Advance (HI+). Each pen had approximately 30 pigs each with 10 pens per dietary treatment. Pig BW and feed were measured as were the number and BW of dead pigs (mortality) and other pig removals (morbidity). Pigs were harvested beginning on d 105 and weekly thereafter through d 126. No significant (P > 0.16) interactions between DDGS level and Rovabio Advance were observed. Feeding greater levels of DDGS tended to reduce average daily gain (ADG), final BW and carcass weight (P < 0.09) and reduced mortality and morbidity (P = 0.1). Greater levels of DDGS also reduced cost of gain and improved income over feed (P < 0.04). Feeding Rovabio Advance reduced mortality and morbidity (P = 0.08), reduced standard deviation of carcass weight (P = 0.02), improved carcass price (P = 0.02), and improved income over feed (P = 0.02). Feeding greater levels DDGS slowed growth rate but improved cost of gain and profitability. Rovabio Advance improved mortality and morbidity and reduced variability resulting in improved profitability.

Recent advancements in harnessing biodiesel from microalgae through attached growth systems

Conventional microalgal cultivation method relied on suspended growth or attached growth that uses inert solid surfaces, requiring the addition of external carbon sources to promote microalgal growth. The inert solid substrates for attached microalgae pose constraints on the maximal capabilities of these microorganisms as it does not possess the ability to provide the necessary nutritional support required for optimal microalgal growth. As a result, microalgae are obliged to only rely on the solid substrate as a means of attachment, without any further nutritional provisions. Slower growth rates, larger resource requirements, and exorbitant operating expenses had prompted the exploration of an alternative strategy, i.e; the innovative use of solid organic waste as nutritional source cum attachment platform. The findings of this review unveil key insights into microalgae cultivation system, offering a solution to economic challenges in the production phase. This innovation not only promotes economic feasibility and sustainability, but also contributes to economically viable and environmentally sustainable biofuel production.

Unraveling the adaptive strategies of Mycoplasma hominis through proteogenomic profiling of clinical isolates.

Mycoplasma hominis (M. hominis) belongs to the class Mollicutes, characterized by a very small genome size, reduction of metabolic pathways, including transcription factors, and the absence of a cell wall. Despite this, they adapt well not only to specific niches within the host organism but can also spread throughout the body, colonizing various organs and tissues. The adaptation mechanisms of M. hominis, as well as their regulatory pathways, are poorly understood. It is known that, when adapting to adverse conditions, Mycoplasmas can undergo phenotypic switches that may persist for several generations. To investigate the adaptive properties of M. hominis related to survival in the host, we conducted a comparative phenotypic and proteogenomic analysis of eight clinical isolates of M. hominis obtained from patients with urogenital infections and the laboratory strain H-34. We have shown that clinical isolates differ in phenotypic features from the laboratory strain, form biofilms more effectively and show resistance to ofloxacin. The comparative proteogenomic analysis revealed that, unlike the laboratory strain, the clinical isolates possess several features related to stress survival: they switch carbon metabolism, activating the energetically least advantageous pathway of nucleoside utilization, which allows slowing down cellular processes and transitioning to a starvation state; they reconfigure the repertoire of membrane proteins; they have integrative conjugative elements in their genomes, which are key mediators of horizontal gene transfer. The upregulation of the methylating subunit of the restriction-modification (RM) system type I and the additional components of RM systems found in clinical isolates suggest that DNA methylation may play a role in regulating the adaptation mechanisms of M. hominis in the host organism. It has been shown that based on the proteogenomic profile, namely the genome sequence, protein content, composition of the RM systems and additional subunits HsdM, HsdS and HsdR, composition and number of transposable elements, as well as the sequence of the main variable antigen Vaa, we can divide clinical isolates into two phenotypes: typical colonies (TC), which have a high growth rate, and atypical (aTC) mini-colonies, which have a slow growth rate and exhibit properties similar to persisters. We believe that the key mechanism of adaptation of M. hominis in the host is phenotypic restructuring, leading to a slowing down cellular processes and the formation of small atypical colonies. This is due to a switch in carbon metabolism and activation the pathway of nucleoside utilization. We hypothesize that DNA methylation may play a role in regulating this switch.

An economic indicator of the orbital debris environment

The continued growth of orbital debris increases potential losses faced by commercial operators in Earth's orbits. Yet, there is no commonly accepted measure that describes the orbital debris environment from an economic perspective. This study begins to fill that gap by developing an Orbital Debris Economic Loss Index (ODELI) that measures and tracks the changes in the expected negative economic impact of orbital debris on satellite operators, both in aggregate and in specific orbits. Such information is valuable to the stakeholders, such as policymakers, commercial operators, and the public, in communicating valuable information about the economic state of the orbital debris environment.We illustrate the calculation of the index utilizing the data from 2012 to 2022. The analysis is based on the publicly available data and the Meteoroid and Space Debris Terrestrial Environment Reference (MASTER) orbital debris environment model. Our analysis suggests that the aggregate expected economic damage to Earth's orbits is increasing at a slower rate than the growth rate of the number of satellites or trackable pieces of debris objects. The slower rate of growth in ODELI indices from 2012 to 2022 is explained by a decrease in the average mass of satellites, a reduction in the real cost of placing satellites in orbit, and a commercial preference to launch satellites into orbits with lower debris density.The estimates of annual expected economic losses from debris collisions increased from $86 million to $107 million from 2012 to 2022, and the losses are concentrated in the low-Earth orbit (LEO). However, LEO had the smallest rate of increase in ODELI compared to other orbits. Medium-Earth orbit (MEO), which has the smallest contribution to the combined expected economic losses from debris on the Earth's orbits, experienced the fastest rate of increase in ODELI during the same period.

In situ decrease in rhodolith growth associated with Arctic climate change.

Rhodoliths built by crustose coralline algae (CCA) are ecosystem engineers of global importance. In the Arctic photic zone, their three-dimensional growth emulates the habitat complexity of coral reefs but with a far slower growth rate, growing at micrometers per year rather than millimeters. While climate change is known to exert various impacts on the CCA's calcite skeleton, including geochemical and structural alterations, field observations of net growth over decade-long timescales are lacking. Here, we use a temporally explicit model to show that rising ocean temperatures over nearly 100 years were associated with reduced rhodolith growth at different depths in the Arctic. Over the past 90 years, the median growth rate was 85 μm year-1 but each °C increase in summer seawater temperature decreased growth by a mean of 8.9 μm (95% confidence intervals = 1.32-16.60 μm °C-1, p < .05). The decrease was expressed for rhodolith occurrences in 11 and 27 m water depth but not at 46 m, also having the shortest time series (1991-2015). Although increasing temperatures can spur plant growth, we suggest anthropogenic climate change has either exceeded the population thermal optimum for these CCA, or synergistic effects of warming, ocean acidification, and/or increasing turbidity impair rhodolith growth. Rhodoliths built by calcitic CCA are important habitat providers worldwide, so decreased growth would lead to yet another facet of anthropogenic habitat loss.

Effects of vitamin C dosage levels on growth and survival rate of sidat fish (Anguilla bicolor, McClelland, 1844)

Eel is a species with high economic value, but its slow growth and low survival rate are problems that need to be addressed through the development of effective cultivation technology. This study aimed to investigate the effects of vitamin C dosage on the growth and survival of eels (Anguilla bicolor). This study was conducted at the UPR. Mina Mandiri, Beutong District, Nagan Raya Regency, during the period August to October 2023. The method used was a completely randomized design with four treatment levels and three replications, namely 0, 200, 300, and 400 mg/kg feed. ANOVA results showed that the dose of vitamin C had a significant effect on the growth and survival of eels (P &lt; 0.05). Further tests using Duncan's method showed significant differences between treatments in growth parameters, but there was no significant difference in survival. The 200 mg/kg feed dose showed the highest and optimal results in terms of increasing the growth and survival of eel fish.Keywords: Culture technology; eel; growth; vitamin C

Using Passive Surveillance to Maintain Elimination as a Public Health Problem for Neglected Tropical Diseases: A Model-Based Exploration.

Great progress is being made toward the goal of elimination as a public health problem for neglected tropical diseases such as leprosy, human African trypanosomiasis, Buruli ulcer, and visceral leishmaniasis, which relies on intensified disease management and case finding. However, strategies for maintaining this goal are still under discussion. Passive surveillance is a core pillar of a long-term, sustainable surveillance program. We use a generic model of disease transmission with slow epidemic growth rates and cases detected through severe symptoms and passive detection to evaluate under what circumstances passive detection alone can keep transmission under control. Reducing the period of infectiousness due to decreasing time to treatment has a small effect on reducing transmission. Therefore, to prevent resurgence, passive surveillance needs to be very efficient. For some diseases, the treatment time and level of passive detection needed to prevent resurgence is unlikely to be obtainable. The success of a passive surveillance program crucially depends on what proportion of cases are detected, how much of their infectious period is reduced, and the underlying reproduction number of the disease. Modeling suggests that relying on passive detection alone is unlikely to be enough to maintain elimination goals.

The CHY-type zinc finger protein MoChy1 is involved in polarized growth, conidiation, autophagy and pathogenicity of Magnaporthe oryzae

Polarized growth is critical for the development of filamentous phytopathogens, and the CHY-type zinc finger protein Chy1 regulates microtubule assembly to influence polarized growth and thereby affect plant infections. However, the biological role of a Chy1 homolog MoChy1 remains unknown in Magnaporthe oryzae. We found here that the MoChy1-GFP was distributed in the cytoplasm outside the vacuole in hyphae and localized mainly to the vacuole compartments as the appressorium matured. The Mochy1 mutants showed an extremely slow growth rate, curved and branched mycelium, reduced conidiation, and a smaller size in the appressorium. Meanwhile, the Mochy1 mutants showed increased sensitivity to benomyl, damaged microtubule cytoskeleton, and mislocalized polarisome protein MoSpa2 and chitin synthase MoChs6 in hyphae. Compared to Guy11, the Mochy1 mutants exhibited increased sensitivity to H2O2, impaired ability to eliminate host-derived ROS and reduced penetration into host plants, resulting in a strong reduction in pathogenicity of Mochy1 mutants. Furthermore, the Mochy1 mutants also exhibited defects in chitin distribution, osmotic stress tolerance, and septin ring organization during appressorium differentiation and fungal development. Nonselective autophagy was negatively regulated in Mochy1 mutants compared to Guy11. In summary, MoChy1 plays multiple roles in fungal polar growth and full virulence of M. oryzae.

Expression of PDLIM5 Spliceosomes and Regulatory Functions on Myogenesis in Pigs

Expression of PDLIM5 Spliceosomes and Regulatory Functions on Myogenesis in Pigs

Impact of greening trends on biogenic volatile organic compound emissions in China from 1985 to 2022: Contributions of afforestation projects

The rapid expansion of green areas in China has enhanced carbon sinks, but it also presents challenges regarding increased biogenic volatile organic compound (BVOC) emissions. This study examines the impact of greening trends on BVOC emissions in China from 1985 to 2001 and from 2001 to 2022, focusing on evaluating long-term trends in BVOC emissions within eight afforestation project areas during these two periods. Emission factors for 62 dominant tree species and provincial Plant Functional Types were updated. The BVOC emission inventories were developed for China at a spatial resolution of 27 km × 27 km using the Model of Emissions of Gases and Aerosols from Nature. The national BVOC emissions in 2018 were estimated at 54.24 Tg, with isoprene, monoterpenes, sesquiterpenes, and other BVOC contributing 26.94 Tg, 2.29 Tg, 0.44 Tg, and 24.57 Tg, respectively. Over the past 37 years, BVOC emissions experienced a slow growth rate of 1.7 % (0.79 Tg) during 1985–2001, followed by a significant increase of 12 % (6 Tg) from 2001 to 2022. BVOC emissions in the eight afforestation project areas increased by 2 % and 20 % during the two periods. From 2001 to 2022, at the regional scale, the Shelterbelt program for the middle reaches of the Yellow River area exhibited the largest rate of increase (43 %) in BVOC emissions. The Shelterbelt program for the upper and middle reaches of the Yangtze River made the most largest contribution (45 %) to the national increase in BVOC emissions. Afforestation projects have shifted towards planting more broadleaf trees than needleleaf trees from 2001 to 2022, and there also showed a change from herbaceous plants to broadleaf trees. These trends have led to higher average emission factors for vegetation, resulting in increased BVOC emissions. It underscores the importance of considering BVOC emissions when evaluating afforestation initiatives, emphasizing the need to balancing ecological benefits with potential atmospheric consequences.

Effects of 2 wintering practices on behavioral and physiological indicators of welfare of nonlactating, pregnant dairy cattle in a pasture-based system

In countries with pasture-based dairy systems and relatively cold winters, such as New Zealand, it is common to manage pregnant, nonlactating cows on forage crop paddocks rather than pasture, due to slow pasture growth rates. Wintering dairy cattle on grazed crops can compromise welfare if wet and muddy underfoot conditions occur, which can reduce lying. This study investigated behavioral and physiological indicators of welfare of cows under 2 wintering practices: cows managed on and grazed kale crop (Brassica oleracea), and cows managed on pasture with baled hay. Following dry-off (d 0), 80 cows were randomly assigned to 1 of the 2 wintering practices (40 cows/practice) and monitored between d 4 and 32 (phase 1). During this period, lying and stepping behavior was continuously recorded using leg-based accelerometers. Blood samples were obtained at d 0 and 32 for measurements of thyroxine (T4), nonesterified fatty acids (NEFA), white blood cells (WBC), and red blood cells. All data for phase 1 were presented descriptively due to the lack of treatment replication. Daily mean air temperature during this period was 5.2°C (range: 0.0-10.7°C), and rainfall was 1.1 mm/d (range: 0-5.6mm/d). Between d 4 and 32, cows in both groups spent similar amounts of time lying (pasture with hay cows: 8.9 h/24 h ± 2.57, kale crop cows: 8.7 h/24 h ± 3.06, mean ± SEM). Both groups reduced their lying on wet and cold days, and there was evidence of rebound lying once unfavorable weather conditions stopped. Cows on kale crop had numerically higher NEFA and lower WBC compared with cows managed on pasture, although most physiological values were within normal ranges. In a second phase of the study (d 34 and 35), cows were managed under controlled, replicated conditions in the 2 wintering practices using typical on-farm stocking rates (2 or 4 cows per group in the pasture with hay and kale crop treatments, respectively; n = 10 groups/treatment). During this period, cow behavior, skin and surface temperatures, hygiene scores, feed intakes, and ground conditions were measured. Weather conditions during the 48-h exposure were mostly cold and dry (mean air temperature: 7.8°C, range: -2.2 to 20.5°C). Cows managed on pasture with hay spent more time lying down on the first day of exposure; however, this was likely due to less space being available to kale cows on this day. Cows managed on pasture with hay ruminated more than cows on kale crop on both days of observations (d 1: 37.9% vs. 30.9% of observations, d 2: 36.8% vs. 28.7% of observations for pasture with hay and kale crop groups, respectively) and were lying more often in postures indicative of greater thermal comfort. Cows managed on pasture with hay had higher skin and surface temperatures compared with cows on kale crop, whereas cows on kale crop had dirtier coats. Results suggest that opportunities for thermal comfort were greater for cows managed on pasture with hay bales, which may be due to increased rumination activities and more insulated lying areas.

High-temperature oxidation behavior of TA15 aerospace titanium alloy at 500 °C and 800 °C

This study investigates the high-temperature oxidation behavior and performance of TA15 Ti alloy subjected to 500 and 800 °C service conditions. The oxidation process, microstructural evolution, mechanical property changes, and comprehensive performance were analyzed. At 500 °C, the alloy developed a distinctive blue-colored surface primarily composed of Ti6O, indicating a slow growth rate of the oxide layer. In contrast, the 800 °C condition led to severe oxidation with notable TiO2 and Al2O3 phases and extensive peeling of the oxidation layer. Microstructural analysis revealed that at 500 °C, there was minimal surface oxidation, and the microstructure showed a shallow heat-affected zone. At 800 °C, repeated oxidation and peeling cycles resulted in grain growth and a significant decrease in the β-phase proportion. Mechanical property assessments indicated an increase in micro Vickers hardness at both temperatures, with the 800 °C sample exhibiting higher values. However, tensile strength decreased significantly at 800 °C due to the severe oxidation layer peeling, reducing the effective thickness during tensile testing. In summary, TA15 demonstrated good high-temperature service performance at 500 °C, while at 800 °C, severe oxidation and peeling adversely affected the overall performance. This research provides insights into the differential high-temperature behavior of TA15, crucial for applications in elevated temperature environments.

Exceptionally high levels of total mercury in deep-sea sharks of the Southeastern Mediterranean sea over the last ∼ 40 years

Deep-sea habitats are currently recognized as a hot spot for mercury (Hg) accumulation from anthropogenic sources, resulting in elevated concentrations of total mercury (THg) in deep-sea megafauna. Among them, deep-sea sharks (Class Chondrichthyes) are characterized by high trophic position and extended longevity and are, therefore, at high risk for mercury contamination. Despite this, sharks are overexploited by fishing activity in increasingly deeper water, worldwide, imposing health risks to human consumption. While it is imperative to better understand long-term mercury contamination in deep-sea megafauna, few historical data sets exist to capture this process. Here we explore four decades (1985–2022) of THg accumulation in five species of deep-sea sharks (G. melastomus, E. spinax, S. rostratus, C. granulosus, and D. licha) of the ultra-oligotrophic Southeastern Mediterranean Sea (SEMS) sampled during 19 research cruises. We exhibited exceptionally high THg levels (per length/weight), the highest as 16.6 μg g−1 (wet wt.), almost entirely (98.9 %; n = 298 specimens) exceeding the limit for safe consumption (0.3–0.5 μg THg g−1 wet wt.). The maximal THg levels of the long-lived species D. licha and C. granulosus in the SEMS were enriched by a factor of ∼ 7 and >10 compared to counterpart species from other oceanic areas, respectively. We attribute this to the ultra-oligotrophic conditions of the SEMS, which cause slower growth rates and dwarfism in deep-sea sharks, resulting in an extended exposure time to mercury contamination. In the long-lived species, C. granulosus and D. licha, a temporal increase of average THg levels of ∼ 80 % was recorded between 1987–1999 and 2021–2022. This likely reflects the long-term accumulation of historical anthropogenic Hg in deep-sea environments, which is further amplified in marginal seas such as the Mediterranean, impacted by global air pollution crossroads and surrounded by land-based pollution sources. Future consumption of products from deep-sea sharks is potentially high risk to human health.

Femtosecond laser-induced ultrafast growth of volcanic-shaped graphene micropillars

Surface micropillars are capable of significantly altering material properties, including anti-reflection, structural color, wettability, and adhesion. Conventional methods for fabricating micropillars are both time-intensive and material-consuming. Recently, a nature-inspired light-induced self-growth method has been proposed to avoid the drawbacks of conventional methods. However, this method suffers from slow growth rates (slower than 3.3 × 102 μm/s) and restricted precursor material (limited to heat-shrinkable shape-memory polymer). Herein, we developed the light-induced method based on femtosecond laser thermal accumulation engineering and realized the self-growth of micropillars on thermal-stable polymers. By inducing localized carbonization rather than heat shrinkage with a high repetition rate laser, given the instantaneous release of large amounts of gases and highly localized stresses during laser carbonization, unique graphene micropillars grow rapidly and spontaneously from the polyimide surface with a growth rate of 4.5 × 103 μm/s. The growth rate of micropillars is increased by an order of magnitude compared to previously reported light-induced methods. Furthermore, the dimensions of these micropillars, including height, diameter, and spacing, can be precisely controlled by modulating the heat accumulation. Last but not least, solar absorbers and light-driven actuators are flexibly fabricated using this method, demonstrating its practical applicability.

An overview of productivity management in Ghana

Improving productivity at the individual, enterprise, and national levels is the surest and quickest way to create wealth and enhance the competitiveness and agility of indigenous enterprises. This paper evaluates the extent to which productivity management has made positive impacts on the growth of economies and poverty alleviation. It also identifies stakeholders' roles and strategies in productivity movements in Asia, Europe, Botswana, and Ghana. Results of the study show that Ghana has relatively lower productivity indices than Asian countries. This accounts for one of the factors responsible for the slow growth rate of the Ghanaian economy and the uncompetitive nature of its indigenous enterprises. Recommendations are made to improve productivity levels in Ghana to catalyze the country's efforts towards the attainment of middle-income economy by 2015.