Shielding gas, metal vapors, and gases trapped inside powders during atomization can result in gas porosity, which is known to degrade the fatigue strength and tensile properties of components made by laser powder bed fusion additive manufacturing. Post-processing and trial-and-error adjustment of processing conditions to reduce porosity are time-consuming and expensive. Here, we combined mechanistic modeling and experimental data analysis and proposed an easy-to-use, verifiable, dimensionless gas porosity index to mitigate pore formation. The results from the mechanistic model were rigorously tested against independent experimental data. It was found that the index can accurately predict the occurrence of porosity for commonly used alloys, including stainless steel 316, Ti-6Al-4V, Inconel 718, and AlSi10Mg, with an accuracy of 92%. In addition, experimental data showed that the amount of pores increased at a higher value of the index. Among the four alloys, AlSi10Mg was found to be the most susceptible to gas porosity, for which the value of the gas porosity index can be 5 to 10 times higher than those for the other alloys. Based on the results, a gas porosity map was constructed that can be used in practice for selecting appropriate sets of process variables to mitigate gas porosity without the need for empirical testing.

The concept of language teacher immunity is a relatively new notion that has been introduced in the field of language teacher psychology. It is imperative that teachers have their inherent immunity strengthened since they have never been intrinsically protected against fluctuations that are unanticipated and beyond their control. In order to achieve this goal, the present research used a quantitative approach in order to investigate the possible effects of teacher immunity on their psychological well-being, buoyancy, and engagement. This study was conducted by sending out three questionnaires to a total of 384 primary language teachers. On the basis of the findings, it was concluded that teacher immunity has the potential to serve as a significant predictor of English as a foreign language (EFL) teachers\' psychological well-being, buoyancy, and engagement. The research\'s conclusions may have substantial implications for education in terms of advancing psychological well-being, buoyancy, and engagement.

The aim of this work is to create a new type of gravimeter that can function effectively in the challenging conditions of space, specifically on the surfaces of planets and moons. The proposed device, called a diamagnetically stabilized magnetically levitated gravimeter (DSMLG), uses magnetic forces to balance a test mass against the force of gravity, allowing for accurate measurements. A diamagnetically stabilized levitation structure comprises a floating magnet, diamagnetic material, and a lifting magnet. The floating magnet levitates between two diamagnetic plates without the need for external energy input due to the interaction between the magnetic forces of the floating magnet and the stabilizing force of the diamagnetic material. This structure allows for stable levitation of the floating magnet without requiring additional energy. The goal is to design a gravimeter that is lightweight, requires minimal power, can withstand extreme temperatures and shocks, and has a low data rate. The authors envision this gravimeter being used on various robotic spacecraft, such as landers and rovers, to study the interiors of rocky and icy celestial bodies. This paper reports on the results of a finite element model analysis of the DSMLG and the strength of the resulting diamagnetic spring. The findings contribute to the understanding of the levitation characteristics of diamagnetically stabilized structures and provide valuable insights for their practical applications, including in the development of the proposed DSMLG.

A macrourid, Coryphaenoides yaquinae sp. inc., was observed to be attracted to bait and exhibiting normal foraging behaviour during a period of 80 min within view of a baited video camera on the sea floor at 7259 m - the deepest ever observation of a fish species with a swim bladder. The buoyancy provided by an oxygen-filled swim bladder at 74.4 MPa pressure was estimated to be 0.164 N, at a theoretical energy cost of 20 kJ, 200 times less than the cost of equivalent lipid buoyancy. During normal metabolism, 192 days would be required to fill the swimbladder. At these depths, oxygen is very incompressible, so changes in volume during ascent or descent are small. However, swimbladder function is crucially dependent on a very low rate of diffusion of oxygen across the swimbladder wall. The oxygen in the swimbladder could theoretically sustain aerobic metabolism for over 1 year but is unlikely to be used as a reserve.

Understanding the ontogeny of diving behaviour in marine megafauna is crucial owing to its influence on foraging success, energy budgets, and mortality. We compared the ontogeny of diving behaviour in two closely related species-northern elephant seals (Mirounga angustirostris, n = 4) and southern elephant seals (Mirounga leonina, n = 9)-to shed light on the ecological processes underlying migration. Although both species have similar sizes and behaviours as adults, we discovered that juvenile northern elephant seals have superior diving development, reaching 260 m diving depth in just 30 days, while southern elephant seals require 160 days. Similarly, northern elephant seals achieve dive durations of approximately 11 min on their first day of migration, while southern elephant seals take 125 days. The faster physiological maturation of northern elephant seals could be related to longer offspring dependency and post-weaning fast durations, allowing them to develop their endogenous oxygen stores. Comparison across both species suggests that weaned seal pups face a trade-off between leaving early with higher energy stores but poorer physiological abilities or leaving later with improved physiology but reduced fat stores. This trade-off might be influenced by their evolutionary history, which shapes their migration behaviours in changing environments over time.

Animals influence how they disperse in the environment by sensing local cues and adapting how they move. However, controlling dispersal can present a particular challenge early in life when animals tend to be more limited in their capacities to sense and move. To what extent and by what mechanisms can newly hatched fish control how they disperse? Here, we reveal hatchling sensorimotor mechanisms for controlling dispersal by combining swim tracking and precise sensory manipulations of a model species, zebrafish. In controlled laboratory experiments, if we physically constrained hatchlings or blocked sensations of motion through vision and the lateral line, hatchlings responded by elevating their buoyancy and passively moving with faster surface currents. Complementarily, in stagnant water, hatchlings covered more ground using hyperstable swimming, strongly orienting based on graviception. Using experimentally calibrated hydrodynamic simulations, we show that these hatchling behaviors nearly tripled diffusivity and made dispersal robust to local conditions, suggesting this multisensory strategy may provide important advantages for early life in a variable environment.

If it were possible to purchase tumour-spheroids as a standardised product, ready for direct use in assays, this may contribute to greater research reproducibility, potentially reducing costs and accelerating outcomes. Herein, we describe a workflow where uniformly sized cancer tumour-spheroids are mass-produced using microwell culture, cryopreserved with high viability, and then cultured in neutral buoyancy media for drug testing. C4-2B prostate cancer or MCF-7 breast cancer cells amalgamated into uniform tumour-spheroids after 48 h of culture. Tumour-spheroids formed from 100 cells each tolerated the cryopreservation process marginally better than tumour-spheroids formed from 200 or 400 cells. Post-thaw, tumour-spheroid metabolic activity was significantly reduced, suggesting mitochondrial damage. Metabolic function was rescued by thawing the tumour-spheroids into medium supplemented with 10 µM N-Acetyl-l-cysteine (NAC). Following thaw, the neutral buoyancy media, Happy Cell ASM, was used to maintain tumour-spheroids as discrete tissues during drug testing. Fresh and cryopreserved C4-2B or MCF-7 tumour-spheroids responded similarly to titrations of Docetaxel. This protocol will contribute to a future where tumour-spheroids may be available for purchase as reliable and reproducible products, allowing laboratories to efficiently replicate and build on published research, in many cases, making tumour-spheroids simply another cell culture reagent.

The aim of this study was to identify the existence of some relationships between certain psychomotor behaviors, which we consider specific to swimming, and learning to execute the technique of some swimming styles (front crawl and backstroke). The study was carried out for 10 months and included 76 children (40 boys and 36 girls) aged between 6 and 9 years who practice recreational swimming in a city in Romania. Several tools were used: the Tapping test for manual dexterity, the Goodenough test for body schema, the Flamingo test for static balance, and the horizontal buoyancy test for body balance on the water. The results indicated better ratings on all psychomotor behaviors analyzed according to gender (in favor of girls compared to boys). The levels of all analyzed psychomotor behaviors have a direct relationship to the subjects\' age. Also, we identified moderate positive correlations for manual dexterity (rs = 0.63 in the front crawl style; rs = 0.57 in the backstroke style) and strong correlations for body schema, static balance and buoyancy, coordination with the learning of the two swimming styles (r or rs between 0.77 and 0.85). In conclusion, psychomotor behaviors can be predictors for learning swimming styles.

Larval zebrafish achieve neutral buoyancy by swimming up to the surface and taking in air through their mouths to inflate their swim bladders. We define this behavior as \'surfacing\'. Little is known about the sensory basis for this underappreciated behavior of larval fish. A strong candidate is the mechanosensory lateral line, a hair cell-based sensory system that detects hydrodynamic information from sources such as water currents, predators, prey and surface waves. However, a role for the lateral line in mediating initial inflation of the swim bladder has not been reported. To explore the connection between the lateral line and surfacing, we used a genetic mutant (lhfpl5b-/-) that renders the zebrafish lateral line insensitive to mechanical stimuli. We observed that approximately half of these lateral line mutants over-inflate their swim bladders during initial inflation and become positively buoyant. Thus, we hypothesized that larval zebrafish use their lateral line to moderate interactions with the air-water interface during surfacing to regulate swim bladder inflation. To test the hypothesis that lateral line defects are responsible for swim bladder over-inflation, we showed that exogenous air is required for the hyperinflation phenotype and transgenic rescue of hair cell function restores normal inflation. We also found that chemical ablation of anterior lateral line hair cells in wild-type larvae causes hyperinflation. Furthermore, we show that manipulation of lateral line sensory information results in abnormal inflation. Finally, we report spatial and temporal differences in the surfacing behavior between wild-type and lateral line mutant larvae. In summary, we propose a novel sensory basis for achieving neutral buoyancy where larval zebrafish use their lateral line to sense the air-water interface and regulate initial swim bladder inflation.

The goal of the present work was to invent an apigenin-stacked gastroretentive microsponge to target H. pylori. The quasi-emulsion technique was used to prepare microsponges, which were then tested for various physicochemical properties, in-vivo gastric retention, and in-vitro anti-H. pylori study. The microsponge that demonstrated a comparatively good product yield (76.23 ± 0.84), excellent entrapment efficiency (97.84 ± 0.85), sustained in-vitro gastric retention period, and prolonged drug release were chosen for further investigations. The microsponge\'s SEM analysis showed that it had a spherical form, porous surface, and interconnected spaces. No drug-polymer interactions were detected in the FTIR investigation. Apigenin was found to be dispersed in the microsponge\'s polymeric matrix according to DSC & XRD investigations. Moreover, the microsponge in the rat\'s stomach floated for 4 h, according to the ultrasonography. The antibacterial activity of apigenin against H. pylori was nearly two folds more than the pure apigenin and had a more sustained release in the best microsponge, according to the in vitro MIC data, when compared to pure apigenin. To sum up, the developed gastroretentive microsponge with apigenin offers a viable alternative for the efficient targeting of H. pylori. But more preclinical & clinical studies of our best microsponge would yield considerably more fruitful results.