Increase in steryl glycoside levels and stimulation of lipid raft formation in azuki bean epicotyls under hypergravity conditions.

Sterols are the main components of the plasma membrane and are involved in various plant membrane functions. Azuki bean (Vigna angularis (Wild.) Ohwi et Ohashi) seedlings were cultivated under hypergravity conditions, and changes in the levels and composition of membrane sterols in their epicotyls were analyzed. Under hypergravity conditions at 300 g, the levels of steryl glycosides and acyl steryl glycosides per unit length and per gram fresh weight greatly increased, which accounted for an increase in the total sterol levels. Stigmasterol, ß-sitosterol, and campesterol were the most abundant sterols. Hypergravity decreased the proportion of stigmasterol but increased that of ß-sitosterol. The fatty chains of acyl steryl glycosides mainly consisted of palmitic acid (C16:0), stearic acid (C18:0), linoleic acid (C18:2), and α-linolenic acid (C18:3), and their proportions were not modified under hypergravity conditions. In addition, the density of membrane microdomains, visualized with anti-Flotillin 1 antibody per unit area, increased by hypergravity, suggesting that lipid raft formation was stimulated. These results support the hypothesis that lipid rafts are involved in plant response and resistance to gravity.

Do media events still unite the host nation's citizens? The case of the Tokyo 2020 Olympic Games.

The Olympic Games are a typical media event and are seen as a festive occasion that monopolizes people's attention through the mass media. The Games and their media coverage have a predetermined schedule that enhances the nation's sense of unity by placing a temporary truce on political conflicts. Governments, especially those of Olympic host countries, tend to take advantage of this effect to garner support for their own policies. However, the effects of such media events may be weakening owing to changes in the media environment and increasing political polarization. Examining the 2020 Tokyo Olympic Games, this case study analyzes a large amount of Twitter data to probe Japanese social media users' attitudes toward the Olympic Games and the relationship of these attitudinal changes with their attitudes toward the political leadership of the prime minister. The results showed that previously negative attitudes toward the Olympic Games improved as people enjoyed the event. However, this positive shift did not appear to be associated with their attitudes toward the prime minister. Users' political predispositions strongly determined their attitudes toward the Olympic Games, indicating that the Olympic Games as a media event had limited implications for support for the administration.

Japanese conservative messages propagate to moderate users better than their liberal counterparts on Twitter.

To examine conservative-liberal differences in the extent to which partisan tweets reach less partisan moderate users in a nonwestern context, we analyzed a network of retweets about former Japanese Prime Minister Shinzo Abe. The analyses consistently demonstrated that partisan tweets originating from the conservative cluster reach a wider range of moderate users than those from the liberal cluster. Network analyses revealed that while the conservative and the liberal clusters' internal structures were similar, the conservative cluster reciprocated the follows from moderate accounts at a higher rate than the liberal cluster. In addition, moderate accounts reciprocated the conservative cluster's following at a higher rate than they did for the liberal cluster. The analysis of tweet content showed no difference in the frequency of hashtag use between conservatives and liberals, but there were differences in the use of emotion words and linguistic expressions. In particular, emotion words related to the propagation of messages, such as those expressing "dislike", were used more frequently by conservatives, while the use of adjectives by conservatives was closer to that of moderate users, indicating that conservative tweets are more palatable for moderate users than liberal tweets.

Dense and influential core promotion of daily viral information spread in political echo chambers.

Despite the intensive study of the viral spread of fake news in political echo chambers (ECs) on social networking services (SNSs), little is known regarding the underlying structure of the daily information spread in these ECs. Moreover, the effect of SNSs on opinion polarisation is still unclear in terms of pluralistic information access or selective exposure to opinions in an SNS. In this study, we confirmed the steady, highly independent nature of left- and right-leaning ECs, both of which are composed of approximately 250,000 users, from a year-long reply/retweet network of 42 million Japanese Twitter users. We found that both communities have similarly efficient information spreading networks with densely connected and core-periphery structures. Core nodes resonate in the early stages of information cascades, and unilaterally transmit information to peripheral nodes. Each EC has resonant core users who amplify and steadily spread information to a quarter of a million users. In addition, we confirmed the existence of extremely aggressive users of ECs who co-reply/retweet each other. The connection between these users and top influencers suggests that the extreme opinions of the former group affect the entire community through the top influencers.

Alteromonas gracilis sp. nov., a marine polysaccharide-producing bacterium.

A novel exopolysaccharide-producing bacterium, designated strain 9a2(T), was isolated from Pacific Ocean sediment. The strain was Gram-stain-negative, motile, strictly aerobic, oxidase- and catalase-positive, and required NaCl for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile consisted mainly of C16 : 1ω7c, C18 : 1ω9c and C16 : 0. The DNA G+C content was 46.6 mol%. 16S rRNA gene sequence analysis suggested that strain 9a2(T) is a member of the genus Alteromonas . Strain 9a2(T) exhibited closest phylogenetic affinity to Alteromonas macleodii NBRC 102226(T) (99.3% 16S rRNA gene sequence similarity), A. marina SW-47(T) (99.3%), A. litorea TF-22(T) (99.0%), A. australica H17(T) (98.7%), A. simiduii BCRC 17572(T) (98.5%), A. stellipolaris LMG 21861(T) (98.3%) and A. hispanica F-32(T) (98.2%). The DNA-DNA reassociation values between strain 9a2(T) and A. macleodii JCM 20772(T), A. marina JCM 11804(T), A. litorea JCM 12188(T), A. australica CIP 109921(T), A. simiduii JCM 13896(T), A. stellipolaris LMG 21861(T) and A. hispanica LMG 22958(T) were below 70%. Strain 9a2(T) contained phosphatidylethanolamine, phosphatidylglycerol and an unidentified polar lipid. Owing to differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene sequences and DNA-DNA relatedness data, the isolate merits classification as representing a novel species, for which the name Alteromonas gracilis sp. nov. is proposed. The type strain of this species is 9a2(T) ( =JCM 30236(T) =NCIMB 14947(T)).

Psychrobacter oceani sp. nov., isolated from marine sediment.

A novel marine bacterium, designated strain 4k5(T), was isolated from a sediment sample of the Pacific Ocean. The strain was Gram-stain-negative, strictly aerobic, non-motile, oxidase-positive and catalase-positive and required Na(+) for growth. Its major isoprenoid quinone was ubiquinone 8 (Q-8), and its cellular fatty acid profile consisted mainly of C18 : 1v9c (71.4%), C16 : 1v7c (9.1%) and C18 : 0. The DNA G+C content was 45.3 mol%. 16S rRNA gene sequence analysis suggested that strain 4k5(T) is a member of the genus Psychrobacter . Strain 4k5(T) exhibited the closely phylogenetic affinity to Psychrobacter pacificensis IFO 16270(T) (99.4% 16S rRNA gene sequence similarity), P. piscatorii T-3-2(T) (97.7%), P. nivimaris 88/2-7(T) (97.7%), P. celer SW-238(T) (97.7%), P. aestuarii SC35(T) (97.6%) and P. vallis CMS39(T) (97.6%). DNA-DNA hybridization between strain 4k5(T) and P. pacificensis NBRC 103191(T), P. piscatorii JCM 15603(T). P. nivimaris DSM 16093(T), P. celer JCM 12601(T), P. aestuarii JCM 16343(T) and P. vallis DSM 15337(T) was 42.5, 47.0, 38.1, 23.7, 9.0 and 27.4%, respectively. Owing to the significant differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on the 16S rRNA gene sequence and DNA-DNA relatedness data, the isolate merits classification within a novel species, for which the name Psychrobacter oceani sp. nov. is proposed. The type strain is 4k5(T) ( = JCM 30235(T) =NCIMB 14948(T)).

Maintenance of Chloroplast Structure and Function by Overexpression of the Rice MONOGALACTOSYLDIACYLGLYCEROL SYNTHASE Gene Leads to Enhanced Salt Tolerance in Tobacco.

In plants, the galactolipids monogalactosyldiacylglycerol (MGDG) and digalactodiacylglycerol (DGDG) are major constituents of photosynthetic membranes in chloroplasts. One of the key enzymes for the biosynthesis of these galactolipids is MGDG synthase (MGD). To investigate the role of MGD in the plant's response to salt stress, we cloned an MGD gene from rice (Oryza sativa) and generated tobacco (Nicotiana tabacum) plants overexpressing OsMGD. The MGD activity in OsMGD transgenic plants was confirmed to be higher than that in the wild-type tobacco cultivar SR1. Immunoblot analysis indicated that OsMGD was enriched in the outer envelope membrane of the tobacco chloroplast. Under salt stress, the transgenic plants exhibited rapid shoot growth and high photosynthetic rate as compared with the wild type. Transmission electron microscopy observation showed that the chloroplasts from salt-stressed transgenic plants had well-developed thylakoid membranes and properly stacked grana lamellae, whereas the chloroplasts from salt-stressed wild-type plants were fairly disorganized and had large membrane-free areas. Under salt stress, the transgenic plants also maintained higher chlorophyll levels. Lipid composition analysis showed that leaves of transgenic plants consistently contained significantly higher MGDG (including 18:3-16:3 and 18:3-18:3 species) and DGDG (including 18:3-16:3, 18:3-16:0, and 18:3-18:3 species) contents and higher DGDG-MGDG ratios than the wild type did under both control and salt stress conditions. These results show that overexpression of OsMGD improves salt tolerance in tobacco and that the galactolipids MGDG and DGDG play an important role in the regulation of chloroplast structure and function in the plant salt stress response.

Specific induction of TaAAPT1, an ER- and Golgi-localized ECPT-type aminoalcoholphosphotransferase, results in preferential accumulation of the phosphatidylethanolamine membrane phospholipid during cold acclimation in wheat.

Cold acclimation requires substantial alteration in membrane property. In contrast to well-documented fatty acid unsaturation during cold acclimation, changes in phospholipid biosynthesis during cold acclimation are less understood. Here, we isolated and characterized two aminoalcoholphosphotransferase (AAPT) cDNAs, TaAAPT1 and TaAAPT2, from wheat. AAPTs utilize diacylglycerols and CDP-choline/ethanolamine as substrates and catalyze the final step of the CDP-choline/ethanolamine pathway for phosphatidylcholine (PC)/phosphatidylethanolamine (PE) synthesis, respectively. Functionality of TaAAPT1 and TaAAPT2 was demonstrated by heterologous expression in a yeast cpt1Delta ept1Delta double mutant that lacks both AAPT activities. Detailed characterization of AAPT activities from the transformed mutant cells indicated that TaAAPT1 is an ECPT-type enzyme with higher ethanolamine phosphotransferase (EPT) activity than choline phosphotransferase (CPT) activity, while TaAAPT2 is a CEPT-type with the opposite substrate preference. Transient expression of GFP-fused TaAAPT1 and TaAAPT2 proteins in wheat and onion cells indicated they are localized to both the endoplasmic reticulum and Golgi apparatus, suggesting that the final synthesis of PE and PC via the CDP-choline/ethanolamine pathway occurs in these organella. Quantitative PCR analyses revealed that TaAAPT1 expression is strongly induced by cold, while TaAAPT2 was constitutively expressed at lower levels. Measurement of phospholipid content in wheat leaves indicated that PE is more prominently increased in response to cold than PC and accordingly PE/PC ratio increased from 0.385 to 0.530 during 14 days of cold acclimation. Together, these data suggested that an increase in the PE/PC ratio during cold acclimation is regulated at the final step of the biosynthetic pathway.

Tobacco smoking produces widespread dominant brain wave alpha frequency increases.

The major pharmacological ingredient in tobacco smoke is nicotine, a mild stimulant known to alter brain electrical activity. The objective of this study was to determine if tobacco smoking in humans produces localized or widespread neocortical dominant alpha electroencephalographic (EEG) frequency increases consistent with nicotine stimulation of the brainstem activating system in animals. Twenty-two male volunteer non-deprived tobacco smokers were studied. They were asked not to smoke for at least 1h before the experiment in mid-morning as part of their usual smoking schedule. In the laboratory, they sham smoked and then smoked their favorite tobacco cigarette. Two experimental sessions (#1 and #2) were conducted, separated by a one to two month interval. In both sessions, there were minor statistically significant increases in the dominant alpha frequencies after sham smoking. In both sessions, after the subjects smoked a favorite tobacco cigarette there was a significant generalized increase in dominant alpha EEG frequencies in most scalp recording sites. This study demonstrates that tobacco smoking produces widespread bilateral neocortical increases in dominant alpha EEG frequencies consistent with the stimulant effects of nicotine on the brainstem reticular activating system.