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As the need for teaching Artificial Intelligence (AI) for K-12 is increasing, discussions on what competencies teacher should have for effective teaching of AI is overlooked. In this work, we determine what teacher competencies are necessary for improving the teaching and learning of AI for K-12 with Technological Pedagogical Content Knowledge (TPACK) framework. First, we identify current AI education resources and investigate the core foundations of AI taught to K-12. Based on the findings, we propose teacher competency for K-12 AI education by analyzing AI curricula and resources using the TPACK framework. We conclude that teachers who teach AI to K-12 students require TPACK to construct, prepare an environment, and facilitate project-based classes that solve problems using AI technologies.

TFEB, a key regulator of lysosomal biogenesis and autophagy, is induced not only by nutritional deficiency but also by organelle stress. Here, we find that Tfeb and its downstream genes are upregulated together with lipofuscin accumulation in adipose tissue macrophages (ATMs) of obese mice or humans, suggestive of obesity-associated lysosomal dysfunction/stress in ATMs. Macrophage-specific TFEB-overexpressing mice display complete abrogation of diet-induced obesity, adipose tissue inflammation and insulin resistance, which is independent of autophagy, but dependent on TFEB-induced GDF15 expression. Palmitic acid induces Gdf15 expression through lysosomal Ca2+-mediated TFEB nuclear translocation in response to lysosomal stress. In contrast, mice fed a high-fat diet with macrophage-specific Tfeb deletion show aggravated adipose tissue inflammation and insulin resistance, accompanied by reduced GDF15 level. Finally, we observe activation of TFEB–GDF15 in ATMs of obese humans as a consequence of lysosomal stress. These findings highlight the importance of the TFEB–GDF15 axis as a lysosomal stress response in obesity or metabolic syndrome and as a promising therapeutic target for treatment of these conditions. Kim et al. reveal that TFEB expression is protective in the setting of diet-induced obesity by activating the expression of GDF15 in adipose tissue macrophages in mice and humans.

The NLRP3 inflammasome is activated by mitochondrial damage and contributes to kidney fibrosis. However, it is unknown whether PGC-1α, a key mitochondrial biogenesis regulator, modulates NLRP3 inflammasome in kidney injury. Primary renal tubular epithelial cells (RTECs) were isolated from C57BL/6 mice. The NLRP3 inflammasome, mitochondrial dynamics and morphology, oxidative stress, and cell injury markers were examined in RTECs treated by TGF-β1 with or without Ppargc1a plasmid, PGC-1α activator (metformin), and siPGC-1α. In vivo, adenine-fed and unilateral ureteral obstruction (UUO) mice were treated with metformin. In vitro, TGF-β1 treatment to RTECs suppressed the expressions of PGC-1α and mitochondrial dynamic-related genes. The NLRP3 inflammasome was also activated and the expression of fibrotic and cell injury markers was increased. PGC-1α induction with the plasmid and metformin improved mitochondrial dynamics and morphology and attenuated the NLRP3 inflammasome and cell injury. The opposite changes were observed by siPGC-1α. The oxidative stress levels, which are inducers of the NLRP3 inflammasome, were increased and the expression of TNFAIP3, a negative regulator of NLRP3 inflammasome regulated by PGC-1α, was decreased by TGF-β1 and siPGC-1α. However, PGC-1α restoration reversed these alterations. In vivo, adenine-fed and UUO mice models showed suppression of PGC-1α and TNFAIP3 and dysregulated mitochondrial dynamics. Moreover, the activation of oxidative stress and NLRP3 inflammasome, and kidney fibrosis were increased in these mice. However, these changes were significantly reversed by metformin. This study demonstrated that kidney injury was ameliorated by PGC-1α-induced inactivation of the NLRP3 inflammasome via modulation of mitochondrial viability and dynamics.

Resistive switching memory that uses halide perovskites (HP) has been considered as next-generation storage devices due to low operation voltage and high on/off ratio. However, the memory still faces challenges for stable operation with fast switching speed, which hinders the practical application. Thus, it should be considered from the stage of designing the HP for memory applications. Here, we design the perovskite memory using a high-throughput screening based on first-principles calculations. Total 696 compositions in four different crystal structures are investigated and essential parameters including stability, vacancy formation, and migration are considered as the descriptor. We select dimer-Cs3Sb2I9 as an optimal HP for memory; the device that uses dimer-Cs3Sb2I9 has ultra-fast switching speed (~20 ns) compared to the device that uses layer-Cs3Sb2I9 (>100 ns). The use of lead-free perovskite avoids environmental problems caused by lead in perovskite. These results demonstrate the feasibility to design the memory with ultra-fast switching speed., Halide perovskite has been applied for resistive switching memory devices, but there are challenges remained to achieve practical application. By using high-throughput screening based on first-principles calculations, the authors discover that lead-free dimer-Cs3Sb2I9 meets the requirements, which exhibits switching speed of 20 ns.

Kidney tubular cell death induced by transforming growth factor-β1 (TGF-β1) is known to contribute to diabetic nephropathy, a major complication of diabetes. Caspase-3-dependent apoptosis and caspase-1-dependent pyroptosis are also involved in tubular cell death under diabetic conditions. Recently, ferroptosis, an atypical form of iron-dependent cell death, was reported to cause kidney disease, including acute kidney injury. Ferroptosis is primed by lipid peroxide accumulation through the cystine/glutamate antiporter system X

A metal oxide-heterojunction photocatalyst is developed to harvest sunlight, store the energy in electrons, and apply the stored energy in water treatment. Light-absorbing nanoparticular and nanotubular TiO2 are hybridized with electron-storing WO3 at different weight ratios of TiO2 to WO3 (e.g., TW25 represents a composite of 25 wt% TiO2 and 75 wt% WO3). The ability of the TW composite to utilize the stored electrons is examined for the reduction of hexavalent chromium (Cr(VI)). In the photoelectrochemical (PEC) tests, irradiation using simulated sunlight (AM 1.5, 100 mW cm−2) leads to a rapid shift in the open-circuit potential (OCP) of the TW electrodes to the negative potential region (photocharging process). The termination of irradiation causes a gradual shift of the OCP to the positive potential region over 20 h (discharging process). Spiked Cr(VI) added to the solution with pre-photocharged TW electrodes is efficiently removed; the kinetics of this process depends on the TW composition (25, 50, or 75 wt%), TiO2 morphology (particular or tubular), initial Cr(VI) concentration (0.125 or 0.25 ppm), and whether the conditions are aerated or non-aerated. Based on this knowledge, TW composite-embedded inorganic membranes are synthesized and charged using sunlight. For Cr(VI) removal, single-pass and continuous circulation filtration systems are employed. The fraction of Cr(VI) removed from the circulation system is ∼30% in 4 h, which is 1.5 times that removed using the single-pass filtration system (∼20%). An X-ray photoelectron spectroscopy analysis of the TW membranes used for Cr(VI) removal reveals that Cr is not sorbed in the membrane. The W(VI) in WO3 is partially reduced to W(6−x)+ upon photocharging and is oxidized during the reduction of Cr(VI), leading to the co-existence of W6+ and W(6−x)+.

This study investigated a method for monitoring fish flux though a set net in the coastal South Sea, Korea, using sideward-looking wide angle multi-beam imaging sonar (blueview). This data set was used to examine the impact of changes in diel variation and current speed from a set net. During nighttime, the influx of fish in the set net was significantly 22 times higher than in daytime. The time when high fish flux was observed corresponded to the time of low current speed during nighttime. In contrast, the fish flux was not affecting current speed during daytime. The study provides implications for understanding fish behavior through use of a set net.

Nemopilema nomurai jellyfish, which are believed to complete their development in the East China Sea, have started migrating into the Yellow Sea in recent years. We obtained biomass estimates of this species in the Yellow Sea using bottom trawl fishing gear and sighting surveys over a 5-year period. These methods are effective for obtaining N. nomurai jellyfish density estimates and information about the community distribution near the bottom or surface of the sea. To verify the vertical distributions of giant jellyfish between, we used hydroacoustic equipment, including an optical stereo camera system attached to a towed sledge and an echo counting method with scientific echosounder system. Acoustic and optical data were collected while the vessel moved at 3 knots, from which the distribution and density of N. nomurai jellyfish were analyzed. Subsequently, the camera system was towed from a 7 m mean depth to sea level, with the detection range of the acoustic system extending from an 8 m depth to the bottom surface. The optical and acoustic methods indicated the presence of vertical distribution of 0.113 (inds/m3) and 0.064 (inds/m3), respectively. However, the vertical distribution indicated that around 93% of individuals occurred at a depth range of 10–40 m; thus, a 2.4-fold greater density was estimated by acoustic echo counting compared to the optical method.

Growth differentiation factor 15 (GDF15) is an endocrine hormone belonging to the TGFβ superfamily member. GDF15 administration or GDF15 overexpression has been reported to have anti-obesity and anti-diabetic effects. Although non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) is frequently associated with obesity and insulin resistance, the functional role of endogenous GDF15 and therapeutic effect of GDF15 overexpression in NASH and related metabolic deterioration have not been evaluated. Here, we found that GDF15 expression was increased in the livers of NASH animal models and human subjects with NASH. Elevated expression of GDF15 was due to diet-induced hepatic endoplasmic reticulum (ER) stress. Gdf15-knockout mice exhibited aggravated NASH phenotypes such as increased steatosis, hepatic inflammation, fibrosis, liver injury, and metabolic deterioration. Furthermore, GDF15 directly suppressed expression of fibrosis-related genes and osteopontin (OPN), contributing factors for NASH-related fibrosis, in hepatic stellate cells in vitro and in the liver of mice in vivo. Finally, we found that GDF15-transgenic mice showed attenuation of NASH phenotypes and metabolic deterioration. Therefore, our results suggest that induction of endogenous GDF15 is a compensatory mechanism to protect against the progression of NASH and that GDF15 could be an attractive therapeutic candidate for treatment of NASH and NASH-related metabolic deterioration.

Glycogen synthase kinase-3β (GSK-3β) is involved in the pathogenesis of various kidney diseases. This study was undertaken to examine the changes in GSK-3β activity in podocytes under diabetic conditions and to elucidate the functional role of GSK-3β in podocyte apoptosis. In vivo, 32 rats were injected with either diluent (n = 16, C) or with streptozotocin intraperitoneally (n = 16, DM), and 8 rats from each group were treated with 6-bromoindirubin-3'-oxime (BIO) for 3 months. In vitro, immortalized mouse podocytes were exposed to 5.6 mM glucose or 30 mM glucose (HG) with or without 10 μM BIO. Western blot analysis and TUNEL or Hoechst 33342 staining were performed to identify apoptosis. Urinary albumin excretion was significantly higher in DM rats, and this increase was significantly abrogated in DM rats by BIO treatment. The protein expression of Tyr216-phospho-GSK-3β was significantly increased in DM glomeruli and in cultured podocytes exposed to HG. Western blot analysis revealed that the protein expression of Bax and active fragments of caspase-3 were significantly increased, whereas phospho-Akt, β-catenin, and Bcl-2 protein expression were significantly decreased in DM glomeruli and HG-stimulated podocytes. Apoptosis, determined by TUNEL assay and Hoechst 33342 staining, was also significantly increased in podocytes under diabetic conditions. The changes in the expression of apoptosis-related molecules and the increase in the number of apoptotic cells in DM glomeruli as well as in HG-stimulated podocytes were significantly ameliorated by BIO. These findings suggest that enhanced GSK-3β activity within podocytes under diabetic conditions is associated with podocyte loss in diabetic nephropathy.

Lost or abandoned fishing gear made of synthetic fibers or plastics that do not decompose in the sea. These gear result in “ghost fishing”, that retain their function as fishing gear. To solve this problem, we developed fishing gear made of aliphatic polyester (PBS/PBAT), which is biodegraded by microorganisms after a certain period. The marine fishing performance of the biodegradable material of tubular pots for conger eel was compared with that of commercial pots in the southern coastal sea of Korea, where fishing gear loss rates are high. A comparative analysis of the elastic recovery of different types of funnel material was conducted. Two types of fishing gear were tested: (1) a pot with a body and funnel made of biodegradable materials and (2) a commercial pot made of recycled polyethylene (PE). Then, field experiments were conducted on the two pot types, which were arranged alternately. The funnel rips made of biodegradable material showed better elastic recovery than that of the commercial pot. Marine fishing performance of the biodegradable pots was similar to that of the commercial pots (Mann–Whitney test, p > 0.05). There was also no significant difference in the catch per unit effort (CPUE) by the Mann–Whitney test, p > 0.05. Thus, biodegradable materials represent an environmentally friendly alternative to recycled PE for fabricating tubular pots to catch conger eel.

The thermotolerant methylotrophic yeast Hansenula polymorpha is able to grow at elevated temperature up to 48 °C as one of a few yeast strains which are naturally capable of alcoholic fermentation of xylose, a pentose sugar abundant in lignocellulosic biomass. However, the current level of ethanol production from xylose by H. polymorpha is still very low compared to those of other xylose-fermenting strains. Therefore, it is necessary to analyze and remodel the xylose metabolism in H. polymorpha at the whole genome level to identify and overcome these limits. In the present study, the transcriptomes of H. polymorpha grown on xylose were compared with those of glucose-grown cells under both aerobic and microaerobic conditions. Approximately, two percent of H. polymorpha genes were either up- or down-regulated by more than two-fold during the growth on xylose. The majority of the up-regulated genes were involved in metabolism. Some genes involved in xylose metabolism, such as XYL1, XYL2, and TAL1 were also up-regulated, despite the fact that the differences in their induction level were only about three-fold. On the other hand, the majority of the down-regulated genes were involved in metabolism and cellular transport. Interestingly, some genes involved in glycolysis and ethanol fermentation were also repressed during growth on xylose, suggesting that these genes are good targets for engineering H. polymorpha to improve xylose fermentation.

Recently, the increasing population of giant jellyfish Nemopilema nomurai has negatively affected coastal fisheries in Korea. As a result, the fishing industry has begun developing devices to prevent jellyfish capture. In this study, we assessed the performance of a conical jellyfish exclusion device in the coastal areas of Yokji Island in southern Korea during 2009. After hauling, we measured the length, diameter, and weight of the jellyfish and fish that were captured by the cod end and cover net. We found that the captured species included N. nomurai, silver croakers Pennahia argentata, yellow croakers Larimichthys polyactics, shotted halibut Eopsetta grigorjewi, largehead hairtails Trichiurus lepturus, and melon seeds Psenopsis anomala. The catch ratios of the giant jellyfish that entered the cod end in terms of weight ranged from 0.005 to 0.027. In contrast, the catch ratios of total fish in terms of weight and number were 0.793 and 0.835, respectively. On selectivity analysis of a conical separator for individual fish species, their exclusion ratios were independent of their length, and were similar to their observed exclusion ratios in terms of number. These results indicated that the conical jellyfish exclusion device performs well; however, some improvements are needed to minimize the escape of fish from the net.

Sialidases, or neuraminidases (EC 3.2.1.18), belong to a class of glycosyl hydrolases that release terminal N-acylneuraminate residues from the glycans of glycoproteins, glycolipids, and polysaccharides. In bacteria, sialidases can be used to scavenge sialic acids as a nutrient from various sialylated substrates or to recognize sialic acids exposed on the surface of the host cell. Despite the fact that bacterial sialidases share many structural features, their biochemical properties, especially their linkage and substrate specificities, vary widely. Bacterial sialidases can catalyze the hydrolysis of terminal sialic acids linked by the α(2,3)-, α(2,6)-, or α(2,8)-linkage to a diverse range of substrates. In addition, some of these enzymes can catalyze the transfer of sialic acids from sialoglycans to asialoglycoconjugates via a transglycosylation reaction mechanism. Thus, some bacterial sialidases have been applied to synthesize complex sialyloligosaccharides through chemoenzymatic approaches and to analyze the glycan structure. In this review article, the biochemical features of bacterial sialidases and their potential applications in regioselective hydrolysis reactions as well as sialylation by transglycosylation for the synthesis of sialylated complex glycans are discussed.

Achromobacter xylosoxidans is known to utilize d-glucose via the modified Entner-Doudoroff pathway. Although d-gluconate dehydratase produced from this bacterium was purified and partially characterized previously, a gene that encodes this enzyme has not yet been identified. To obtain protein information on bacterial d-gluconate dehydratase, we partially purified d-gluconate dehydratase in A. xylosoxidans and investigated its biochemical properties. Two degenerate primers were designed based on the N-terminal amino acid sequence of the partially purified d-gluconate dehydratase. Through PCR performed using degenerate primers, a 1,782-bp DNA sequence encoding the A. xylosoxidansd-gluconate dehydratase (gnaD) was obtained. The deduced amino acid sequence of A. xylosoxidans gnaD showed strong similarity with that of proteins belonging to the dihydroxy-acid dehydratase/phosphogluconate dehydratase family (COG0129). This is in contrast to the archaeal d-gluconate dehydratase, which belongs to the enolase superfamily (COG4948). The phylogenetic tree showed that A. xylosoxidansd-gluconate dehydratase is closer to the 6-phosphogluconate dehydratase than the dihydroxy-acid dehydratase. Interestingly, a clade containing A. xylosoxidans enzyme was clustered with proteins annotated as a second and a third dihydroxy-acid dehydratase in the genomes of Clostridium acetobutylicum (Cac_ilvD2) and Streptomyces ceolicolor (Sco_ilvD2, Sco_ilvD3), indicating that the function of these enzymes is the dehydration of d-gluconate.