Search

The 3-dimension coordinate datum transformation is very important in geomatics. Generally, there are small angle coordinate transformation model (i.e., Bursa model, et al) and large angle coordinate transformation model (i.e., Rodrigo matrix model, et al). However, these papers only focus on the fixed and static situation regardless of the small or large angle. This paper proposes the conception of coordinate transformation gradient field,which can realize the space coordinate transformation from small angle to arbitrary angle, and from static to dynamical. Based on the equivalent characteristics of the unit quaternion rotation matrix and the Rodrigo matrix, through studying the mathematical relationship between the spatial coordinate transformation and the functional gradient, we derive a functional gradient expression of the arbitrary transformation formula in space. The study shows that the essence of spatial coordinate transformation is a kind of potential field mathematically. This potential field conception can unify all the space coordinate transformations. It is the theoretical foundation for the further study of time continuous space coordinate transformation,and this study gives a new solution for the attitude determination of motion carriers.

Turf quality of Kentucky bluegrass (Poa pratensis L.) often declines during summer when temperatures exceed its optimum range. This study was designed to determine whether application of salicylic acid (SA) to the shoots and soil could improve heat tolerance of Kentucky bluegrass, and to investigate whether SA-induced heat tolerance is related to changes in antioxidant activities. Effects of SA at different concentrations (0, 0.1, 0.25, 0.5, 1, and 1.5 mmol) on heat tolerance were examined in Kentucky bluegrass exposed to 46°C for 72 h in a growth chamber. Influences of SA on the production of active oxygen species (AOS), superoxide anion ([O.sup.*-.sub.2]), and hydrogen peroxide ([H.sub.2][O.sub.2]), and activities of antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT), were examined. Among SA concentrations, 0.25 mmol was most effective in enhancing heat tolerance in Kentucky bluegrass, which was manifested by improved regrowth potential following heat stress of 72 h and maintenance of leaf water content at 77% during the 12-h stress period similar to that under normal temperature conditions. The [O.sub.2] generating rate increased significantly at 6 h of heat stress, and SOD activity increased significantly at 2 h but decreased to the control level at 6 h of heat stress in SA-untreated plants. The SA application suppressed the increase of [O.sub.2]- generating rate and enhanced SOD activity significantly at 2 and 6 h of heat stress, respectively. The SA application decreased [H.sub.2][O.sub.2] level significantly at 2 and 12 h of heat stress, and increased CAT activity significantly within 12 h of heat stress. The results suggest that SA application enhanced heat tolerance in Kentucky bluegrass and SA could be involved in the scavenging of AOS by increasing SOD and CAT activities under heat stress., HEAT STRESS is a major factor limiting growth of cool-season grasses in the warm climatic regions. Heat injury m cool-season turfgrasses has been associated with oxidative stress (Liu and Huang, [...]

Abstract: Silicon (Si) is generally considered a beneficial element for the growth of higher plants, especially for those grown under stressed environments. Recently, the mitigating role of Si in salt stress has received worldwide attention. However, its mechanisms involved remain poorly understood. We studied the effects of Si on plasma membrane fluidity, phospholipids and H+-ATPase activity and reduced glutathione (GSH) concentration with two contrasting barley cultivars differing in their salt tolerance. The results showed that plasma membrane H+-ATPase activity decreased in leaves of plants treated with 120mM NaCl, and this decrease was more obvious in salt-sensitive cultivar (Kepin No. 7) than in salt-tolerant cultivar (Jian 4). Under NaCl stress, plasma membrane fluidity decreased, and the ratio of phospholipids to proteins in plasma membrane vesicles increased. GSH concentration decreased in leaves of plants exposed to 120mM NaCl in salt-sensitive cultivar (but not in salt-tolerant cultivar). Inclusion of 1.0mM Si to the salt treatment increased plasma membrane H+-ATPase activity in both cultivars as compared with the plants treated with 120mM NaCl only. The addition of Si to salt treatment was also found to recover membrane fluidity to control (neither NaCl nor Si added) level, and decrease the ratio of phospholipids to protein. Furthermore, GSH concentration in leaves of salt-treated plants was increased by addition of Si. It is suggested that Si maintain the optimal membrane fluidity and increase GSH concentration, which contributes to reducing oxidative damage to enzymes induced by active oxygen species and enhances plasma membrane H+-ATPase activity under NaCl stress. [Copyright &y& Elsevier]

Summary: In order to analyze the relationship between polyamine oxidative degradation induced by light and the lignin synthesis in cell walls, the activities of diamine oxidases and peroxidase, the contents of H2O2 and lignin, and the growth of hypocotyls in soybean [Glycine max (Linn.) Merr.] grown under light or in darkness were investigated. In comparison with the dark treatment, light irradiation significantly inhibited the growth of soybean hypocotyls and promoted the activities of diamine oxidases and peroxidase as well as the accumulation of H2O2 and lignin. Treatments with the different concentrations of diamine oxidase inhibitors (2-hydroxyethylhydrazine and aminoguanidine) under the light condition inhibited diamine oxidase activity, and decreased the contents of H2O2 and lignin. The results provide evidence for the hypothesis that light irradiation could promote the accumulation of H2O2 and lignin in cell walls by activating polyamine oxidative degradation mediated by diamine oxidases. [Copyright &y& Elsevier]

Objective: This study aims to investigate the oral subgingival microbial community in patients with chronic periodontitis with type 2 diabetes mellitus (CP-T2DM) before and after combined periodontal-endodontic treatment., Methods: A retrospective selection of 88 patients with CP-T2DM (CP-T2DM group) treated at our hospital from May 2021 to June 2022 was conducted. Additionally, 90 patients with CP were selected as the control group (CP group). The study compared the distribution of oral subgingival microbial communities between the two groups and analyzed differences in the distribution of oral subgingival microbial communities in patients with different clinical characteristics within the CP-T2DM group, both before and after treatment., Results: The CP-T2DM group showed lower relative abundances of Cilia and Streptococcus while higher relative abundances of Tannerella and Citrobacter (P < .05) compared to the CP group. Furthermore, the relative abundance of Cilia was found to be negatively correlated with fasting blood glucose (FBG) and HbA1c, whereas the relative abundance of Citrobacter was positively correlated with FBG and HbA1c (P < .05)., Conclusions: Significant differences were observed in the oral subgingival microbial communities distribution between CP-T2DM and CP patients. The relative abundance of ciliate and citrate bacteria was found to be associated with the blood glucose level of patients.

With internationally common-used Glycine max (the salt-tolerant Lee68) and Glycine soja (the salt-sensitive N23232) as reference, this paper studied the polyamines (PAs) contents and polyamine oxidase (PAO) activities in the highly salt-tolerant BB52 (Glycine soja) seedlings, which showed that under 150mmol x L(-1) NaCl stress for 2d, the decrease of Put and Spd contents was more significant, but that of Spd content was less significant in roots of BB52 than in those of Lee68 and N23232. For leaves, the decrease of Put and increase of Spd contents were markedly observed in BB52. The ascent of (Spm + Spd)/Put ratios and descent of Put/PAs ratios showed a positive relation to their salt tolerance. The PAO activity in roots and leaves was all increased, and most obvious in N23232. The relationship between PAs levels in BB52 and its salt tolerance was also discussed.

The salt tolerance of 3 wild soybean (Glycine soja) populations was compared with their relative germination and seedling emergence. The results showed that the salt tolerance of Jiangsu wild soybean (JWS) was the strongest. Under NaCl stress, the dry matter accumulation in wild soybean seedlings decreased, root/shoot ratio increased, and these effects were greater in N23232 (salt-sensitive) than in JWS (salt-tolerant). Determinations on the ion contents in different organs indicated that the Na+ content was higher in stem than in other organs, and the accumulation of Na+ and Cl- in roots was significantly more in JWS than in N23232. The contents of these ions in JWS leaves were much less than those in N23232 leaves. There was no significant difference between selective absorptions of K+ and Na+ (ASK, Na) by the two populations, but the selective transportation of K+ and Na+ (TSK, Na) in stem and leaf was much higher in JWS than in N23232, resulted in the higher K+/Na+ ratio in JWS shoots. It is suggested that the main reason for the salt tolerance in salt-tolerant wild soybean was the accumulation of Na+ and Cl- in roots and stems and the higher selective transportation of K+ from root to shoot.