Soil salinization severely restricts plant growth and threatens ecological sustainability, particularly in soda saline-alkali regions such as the Songnen Plain. Asteraceae plants are widely used in vegetation restoration due to their strong ecological adaptability. In this study, Tagetes erecta L., Cadendula officinalis L., and Leucanthemum maximum (Ramood) DC were selected as experimental materials. Two types of stress (salt and alkali) were applied at five concentration levels each (excluding the distilled-water control), which respectively constituted a salinity gradient and an alkalinity gradient. Seed germination parameters, seedling growth traits, and physiological indicators were measured, and field validation was conducted in areas with mild, moderate, and severe saline-alkali soils in the Songnen Plain. T. erecta L. showed optimal germination at the low concentration of salt and alkalinity (25 mmol/L), exhibiting a “low promotion and high inhibition” pattern, and maintained relatively high vigor under high stress. L. maximum had the highest germination rate under non stress conditions but was highly sensitive to increasing salt and alkalinity, while its root growth remained relatively stable under salt stress. C. officinalis L. was highly sensitive to alkali stress. Alkali stress consistently exerted stronger inhibitory effects on seed germination and seedling growth than salt stress. Field validation further demonstrated that T. erecta L. maintained a significantly higher survival rate under severe saline-alkali conditions (HS) compared to L. maximum and C. officinalis L. ( p < 0.05). This study identified interspecific differences in saline-alkali tolerance among three Asteraceae species, offering a data basis and scientific reference for plant selection and breeding in ecological restoration and landscaping of saline-alkali areas.
Yeast Saccharomyces cerevisiae is a widespread model system in which mechanisms of prion induction and elimination have been identified. New and safe substances and methods are being sought to eliminate prions from cells. In this research, we applied guanidinium hydrochloride (GuHCl) alone and in combination with pulsed electric field treatment against [ PSI + ] prion. The analysis of cell culture optical density and doubling time showed that the method of [ PSI + ] prion elimination increases cell doubling time, with combined treatment having a more severe impact on cell growth than GuHCl treatment alone. Additionally, we found that both elimination methods can impact the optical culture density achieved by [ psi − ] cells. However, the cells in which the [ PSI + ] prion has been eliminated by GuHCl alone are able to reach the same optical density as unaffected [ psi − ] cells and a higher optical density than the affected [ psi − ] cells by GuHCl alone. These findings suggest that the presence and subsequent removal of the [ PSI + ] prion influence early exponential growth, revealing lasting effects on cell growth dynamics that are distinct from previously reported effects on stationary phase survival. This work highlights how prion elimination strategies, including chemical and electric field treatments, can impact post-curing growth behavior in yeast cells.
Biting behavior by males during mating has been widely documented in elasmobranchs; however, its characteristics in the whale shark, Rhincodon typus , remain poorly understood. In this study, we recorded a pectoral fin biting event by a male directed toward a female at Okinawa Churaumi Aquarium on May 12, 2020, using surveillance cameras. Subsequently, we monitored the healing process of the resulting scars through underwater observations and post-mortem tissue analyses over 13 months. The bite marks initially appeared as open wounds, which closed within approximately 4 weeks, and were followed by the regeneration of dermal denticles and progressive melanization that persisted for more than 13 months. Additionally, 523 bite marks (233 dorsal and 290 ventral) were digitized and analyzed using orientation-based analysis and Gaussian mixture model clustering. Three distinct clusters were identified among bite marks attributed to this single documented interaction event, suggesting that variation in jaw orientation or repositioning may have occurred during the event. In this individual, wound closure occurred within approximately 4 weeks, providing a preliminary reference for the temporal interpretation of recent injuries, while melanized scars remained externally visible for more than 13 months. These observations provide a preliminary framework for evaluating pectoral fin bite marks as potential indicators of male–female interaction history in whale sharks, although validation across additional individuals is required. These findings provide a foundation for future studies integrating behavioral observations and scar-based assessments in both ex situ and in situ contexts.
Background Tropical estuaries are exposed to multiple sources of impact within a background of strong natural environmental gradients. Monitoring and managing these ecosystems is challenging because gradients in salinity and hydrodynamics overlap with intense, spatially localized anthropogenic pressures. Benthic biotic indices provide standardized tools for assessing the ecological health of estuaries and are sensitive to multiple impact sources, but as these indices are based on regional taxa assignments, they need testing to verify their capacity to indicate soft-bottom assemblages under stress. Although these indices have been applied across a broad latitudinal range, their performance remain less established in the tropics. Methods We quantified macroinfaunal abundance, richness, diversity and assemblage composition across 64 stations in two tropical estuaries of southeastern Brazil, calculated the AZTI Marine Biotic Index (AMBI) and Multivariate AZTI Marine Biotic Index (M-AMBI), and evaluated their associations with salinity, sediment grain size, organic-matter quality, fecal sterols and trace and major elements. We then quantified multivariate associations between macrofaunal assemblages, benthic ecological indices and environmental gradients. Results Benthic ecological status was spatially heterogeneous, with localized Poor/Bad and High/Good indices within estuarine sectors. Community composition was associated with salinity, sediment grain size, organic-matter quality and fecal sterols. Multivariate tests identified significant associations between community variation and salinity, biopolymeric carbon, sterols, total organic carbon, total nitrogen, fine sediments and selected metals. Overall, the indices captured pronounced station-level variation in both urban and less-developed estuaries, and reveal their value to identify stress within tropical estuaries of Brazil.
Background This study aimed to evaluate the antibacterial action of N-acetylcysteine (NAC), calcium hydroxide Ca(OH) 2 , chlorhexidine digluconate (CHX), and their combinations against five obligate anaerobic bacteria including Fusobacterium nucleatum, Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia , and Parvimonas micra in planktonic and biofilm forms. Methods Eight experimental groups were evaluated in this study including saline solution (SS) (control group), Ca(OH) 2 , CHX, NAC, NAC + Ca(OH) 2 , NAC + CHX, Ca(OH) 2 + CHX, and NAC + Ca(OH) 2 + CHX. The anti-planktonic evaluation was performed by determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) following Clinical and Laboratory Standards Institute guidelines (CLSI M11). The antibiofilm was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and crystal violet (CV) assays. Data were analyzed statistically considering a significant level of ( α ≤ 0.05). Results It was found that the MIC and MBC values of the tested intracanal medications ranged from 1.95–500 mg/mL. MTT and CV assays showed significant, species-dependent antibiofilm activity. CHX was most effective against F. nucleatum ; NAC-based medications, especially combined with Ca(OH) 2 and/or CHX, were superior against P. endodontalis, P. intermedia , and P. micra . Ca(OH) 2 -containing groups were particularly effective against P. gingivalis . Therefore, NAC + Ca(OH) 2 and NAC + Ca(OH) 2 + CHX can be considered as effective combinations of intracanal medication against different obligate anaerobic bacteria.
