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Juglans cathayensis is an endangered plant species and listed as a class H protected species of the national government of China. In order to grasp the current state of J. cathayensis populations and predict the population dynamics in the future, a large-sample investigation was conducted in the sample plots along different altitude gradients in four valleys in J. cathayensis conservation area. According to the diameter at breast height (DBH) class of the trees, the age class structures of the populations were analyzed, and static life tables for J. cathayensis populations in different habitats along the altitude gradient was constructed by smoothing out technique, and comparative fluctuations cycles of the populations in different habitats were carried out by spectral analysis. The results showed that DBH decreased gradually with the increasing altitude. The population was composed of 19 age classes in the low-altitude habitat (1241-1380 m) with the maximum DBH of 91.7 cm, 18 age classes in the middle-altitude habitat (1381-1490 m) with the maximum DBH of 82.8 cm, and 13 age classes in the high-altitude habitat (1491-1670 m) with the maximum DBH of 58.9 cm. Life expectancies of J. cathayensis populations were fluctuant for the same age class at different altitudes and for different age classes at the same altitude. In the three altitude-different habitats, the survival curves of the populations trended toward Deevey- H type and the age structures of the populations were expanding. The eurves of mortality showed three peaks, and the mortality rates of 9 age elasses at 1241-1380 m and 1491-1670 mabove sea levels were the highest, being 55.9% and 89.8%, respectively, and the mortality rate of 12 age elasses at 1381-1490 m above sea level was the highest (79.4%). The population dynamics was significantly affected by the fundamental wave of biological characteristic throughout the life cycle of J. cathayensis population, and small cycles of multi-harmonic superposition with large cycles were presented. J. cathayensis is a long lifespan tree and a major dominant species in this conservation area. The natural regeneration of its current populations is good. If not strong anthropogenic disturbances or severe natural disasters, J. cathayensis would maintain the dominant position in the community. [ABSTRACT FROM AUTHOR]

To adapt ecological environment, typical clonal plants can occur continuously by means of buds. The changes in the bud bank and bud flow in the heterogeneous habitats become the foundation for deep understanding the characteristics of vegetative propagation. By sampling soil from the unit area, a comparative analysis was performed for rhizome bud population dynamics of Phragmites australis community in both meadow soil and saline-alkali soil habitats in meadow grassland of Northeast China. The one-age class rhizome buds formed in the current year were used as input, with the other age classes rhizome buds as output, counting the dormancy buds and death buds. The results showed that the storage, input, output, dormancy, death and the input rates of P. australis rhizome bud populations in meadow soil habitat were significantly higher than that in saline-alkali habitat. There was no significant difference in output rate between the two habitats. The dormant rate in saline-alkali habitat was significantly greater than that in meadow soil habitat. The death rates remained at relatively low levels in both, less than 2%. With the going of growing season, the input buds and input rate of bud bank increased in the two habitats, while the output buds remained relatively stable. The output rate increased first and decreased later, the dormancy buds and dormant rate decreased. Bud bank and bud flow were positively related to soil moisture, soil organic matter and soil available nitrogen content. However, they were negatively related to soil pH value and soil available phosphorus content. Bud bank and bud flow had a similar seasonal variation . Constantly for both habitats, P. australis populations generated new rhizome buds supplied to the bud bank and kept a stable output to maintain their vegetative propagation. [ABSTRACT FROM AUTHOR]

The dynamic variation characteristics of seed bank and the main factors influencing the fate of Prunus divaricata seeds under the pressure of rodent predation and litter coverage were investigated with artificial soil seed banks from September, 2010 to April, 2013. It was found that there was about 48.3% of seeds germinated under the rodent predation disturbance conditions, 50% of the seeds was predated in situ or removed, and only about 4% decayed. The artificial seed bank formed a short-term persistent soil seed bank without any rodent predation disturbance, and the seeds could germinate even though they had been stored in the seed bank for three years. Soil burial provided a lower predation pressure and promoted the recruitment of wild P. divaricata seedlings, removal and predation in situ by animals was an important factor affecting the fate of seeds. At the same time, seeds removed and foraged in situ in the control and litter coverage samples were significantly less than that in the bare soil samples. Ground coverage reduced the removal and predation of seeds by rodents, but the effect was not enough to result in more seedlings. Rodent predation and removal were the main factors that could affect the seed fate and dynamics of seed bank. [ABSTRACT FROM AUTHOR]

Species diversity pattern is a hot topic in the forward field of international biodiversity research. Taking a degraded successional series (six communities distributed in 144 isolated patches) of fragmented Leymus chinensis meadow in Songnen Plain as test objects, this paper studied the spatial patterns of alpha, beta, and gamma diversities and related mechanisms. Eighty seven plant species were recorded, but none of them were distributed across all patches. L. chinensis + Kalimeris integrifolia community or L. chinensis community had higher alpha, beta, and gamma diversities, with more rare species and endemic species, while Kochia sieversiana community had lower alpha, beta, and gamma diversities, with few rare species and no endemic species. The gamma diversity showed significant positive correlation with a diversity, but no correlation with beta diversity. There was a significant power function correlation between the a diversity and the area of single patch of the six communities, but no correlation between the beta diversity (Bray-Curtis similarity index, Sjk ) and the area of single patch of the communities except for L. chinensis + K. integrifolia. Both the alpha angamma diversity showed significant correlations with the mean patch area and total patch area, but the p3beta diversity did not. The higher the species richness in the communities, the more the rare species and endemic species, the larger the possibility of species depopulation in local patches was. The importance of beta diversity for shaping species diversity pattern was related to the degree of habitat fragmentation. [ABSTRACT FROM AUTHOR]

In 2003 and 2006, investigations were made on the age structures of Spodiopogon sibiricus populations as well as the matter productivities and vegetative reproduction capacities of different age-class modules of the populations on the weedy meadow and elm woodland in Songnen Plain of Northeast China. At the two habitats, the tillers of S. sibiricus all consisted of 2-3 age classes, and the rhizomes all composed of 4 age classes. Both the tillers and the rhizomes had the greatest proportion of 1-or 2-year-old, and the age structures were of expansive or stable. The 1-or 2-year-old tiller-node buds were dominant, and the rhizome topmost buds occupied 29.4% -45.0%, being of significance to the population regeneration in the next year. The 1-or 2-year-old modules of the tillers and rhizomes had the highest matter productivity and vegetative reproduction capacity, and the rhizomes had higher vegetative reproduction capacity than the tiller-nodes. [ABSTRACT FROM AUTHOR]

The reproductive tillers of Elymus excelsus population in Songnen Plain were randomly marked with labels every other four days (five times in total) at early earring stage, and the marked tillers were harvested at dough stage, with the differences of their quantitative characteristics as well as the relationships between the quantitative characteristics and the shortened time of reproductive growth were analyzed. With the shortened time of reproductive growth, the quantitative characteristics of the reproductive tillers decreased gradually, which was not beneficial to the reproductive growth,reproductive allocation, and fruiting of reproductive tillers. The later the earring time, the larger the impact on fruiting and reproductive allocation was. When the reproductive growth time was shortened by 16 days, the grain biomass, setting penentage, reproductive allocation玉, and reproductive allocation 域decreased by 99郾4%, 98郾8%, 54郾3%, and 99郾2%, respectively. With the shortened time of reproductive growth, the tiller height decreased linearly, spike biomass, reproductive allocation 玉, and setting penentage decreased exponentially, tiller biomass, spike length, and floret number decreased powerly, and grain biomass, grain number, and reproductive allocation域decreased logarithmically. [ABSTRACT FROM AUTHOR]

By the method of randomly digging up whole ramet tuft while maintaining natural integrity, large samples of Cynodon dactylon clones were collected from a grape orchard abandoned for 2 years without any management in the Yili River Valley Plain of Xinjiang, aimed to quantitatively analyze the growth patterns of their modules. The results showed that the average ramet number of test 30 clones reached 272.6 ± 186.6, among which, vegetative ramets occupied 82.3%, being 4.3 times higher than reproductive ones. The total biomass of the clones was 45.4 ± 40.0 g, in which, rhizomes accounted for 54.4%, while the vegetative ramets, stolons, and reproductive ramets occupied 21.0%,14.8%, and 9.4% of the total, respectively. The accumulative length of rhizomes and stolons reached 5.1 ± 4.7 m and 3.3 ± 3.4 m, while the bud number on stolons and rhizomes was 291.5 ± 246.8 and 78.8 ± 87.4, respectively. The bud number on stolons and rhizomes was positively correlated to the quantitative characters of vegetative ramets, reproductive ramets, stolons, and rhizomes (P0.01), indicating that in Yili River Valley Plain, C. dactylon clone could achieve and maintain its continuous renovation via rhizome buds. [ABSTRACT FROM AUTHOR]

The choroid plexus is composed of epithelial cells situated on the basal layer. The tight junctions between adjacent choroid plexus epithelial cells establish the blood-cerebrospinal fluid barrier. This barrier, in conjunction with the blood-brain barrier, is crucial for the homeostasis of the brain microenvironment. The choroid plexus epithelium secretes cerebrospinal fluid, growth factors, neuropeptides, and lipids into the ventricles and also serves as a gateway for immune cells to enter the brain. The pathophysiology of aging and neurodegenerative diseases remains largely enigmatic, with an increasing body of research linking the choroid plexus to the etiology of these age-related disorders. In this review, we summarize the known relationship between the choroid plexus epithelium and age-related diseases, aiming to provide new therapeutic clues for these disorders.

Carbon (C), nitrogen (N), and phosphorus (P) are important nutrients, and their ecological stoichiometric characteristics can reflect the quality and fertility capacity of soil, which is critical to understanding the stable mechanisms of estuarine wetland ecosystems. Under global changes, the increase in salinity and flooding caused by sea level rise will lead to changes in biogeochemical processes in estuarine wetlands, which is expected to affect the ecological stoichiometric characteristics of soil C, N, and P and ultimately interfere with the stability of wetland ecosystems. However, it remains unclear how the C, N, and P ecological stoichiometric characteristics respond to the water-salt environment in estuarine wetlands. We differentiated changes in the C, N, and P ecological stoichiometric characteristics through an ex-situ culture experiment for 23 months in the Yellow River Estuary Wetland. The five sites with distinct tidal hydrology were selected to manipulate translocation of soil cores from the freshwater marsh to high-, middle-, and low-tidal flats in June 2019. The results showed that soil water content (SWC); electrical conductivity (EC); and C, N, and P ecological stoichiometric characteristics of freshwater marsh soil significantly changed after translocation for 23 months. SWC decreased on the high- and middle-tidal flats ( P <0.05) and increased on the low-tidal flat ( P <0.05). EC increased to different degrees on all three tidal flats ( P <0.05). Soil total organic carbon (TOC) and total nitrogen (TN) were significantly lower on the high-tidal flat ( P <0.05), whereas total phosphorus (TP) was significantly lower on the middle- and high-tidal flats ( P <0.05). C:N was decreased on the high- and middle-tidal flats ( P <0.05); C:P and N:P were lower on the high-tidal flat; and all C, N, and P ecological stoichiometric characteristics showed no change on the low-tidal flat ( P >0.05). Pearson's analysis showed that the ecological stoichiometric characteristics of C, N, and P were related to some properties of soil over the culture sites. The PLS-SEM model showed that the water-salt environment had different effects on soil C:N, C:P, and N:P through the main pathways of negative effects on soil TOC and TP. The results suggest that sea level rise may impact the C, N, and P ecological stoichiometric characteristics in freshwater marsh soil, resulting in some possible changes in the nutrient cycles of estuarine wetlands.

Aim: To evaluate the accuracy, efficiency, and reliability of a handheld infrared eccentric autorefractor (hICA) with artificial intelligence (AI) by comparing its refraction measurements to those recorded using hICA and a clinical table-mounted automatic refractor (TAR)., Methods: A cross-sectional study using three optometers, including hICA with or without AI and TAR, for refractometry of adults (aged 19-49 years old) with no signs of ocular disease or trauma in the absence of cycloplegia. Right and left eye refraction data were recorded, including the spherical equivalent (SE), diopter of spherical power (DS), diopter of cylindrical power (DC) decomposed into vectors J0 and J45, and measurement times. To avoid analytical difficulties associated with the interdependence of observations between eyes from the same individual, the Generalized Estimation Equation was used to compare the SE, DS, J0 and J45 measurements, and the times thereof, among the different groups. The intraclass correlation coefficient (ICC) and Spearman's rank correlation coefficient were used to evaluate correlations among the measurements recorded by the three different instruments. Bland-Altman were used to analyze the precision of the equipment by the agreement., Results: A total of 70 patients (140 eyes; mean age: 31.37y; range: 19-49y) were assessed using refractometry. In a brightly lit environment, there was no significant difference between the mean SE recorded using TAR and that recorded using hICA with AI or without AI (both P >0.05). In an intense-light environment, hICA equipped with AI showed a better detection rate than without AI. Light intensity had a greater effect on dioptric measurements recorded using hICA without AI ( P <0.001) than on those recorded using the one equipped with AI ( P <0.05). Measurement times varied significantly between the different light intensities and instruments ( P <0.05)., Conclusion: For the normal human eyes, AI may improve the accuracy, efficiency, and reliability of measurements recorded using hICA in various light environments., (International Journal of Ophthalmology Press.)

The perennial clonal grasses rely mainly on vegetative reproduction to achieve continuous regeneration. Buds and juvenile tillers formed by buds are potential populations for vegetative reproduction. We compared the composition and size of potential population of Leymus chinensis in the enclosure meadow, long-term mowing meadow, enclosing sand-covered meadow, and forest-grassland, with excavation sampling by unit area and using vegetative reproduction generations to classify the age of tillers, rhizomes and various types of buds and juvenile tillers. The results showed that at the end of the growing season, potential population of L. chinensis was composed of rhizome buds and buds of tiller growing upwards at different ages, as well as juvenile tillers on the tillers and rhizomes. Across the four habitats, the potential population of tillers of L. chinensis was composed of 3-4 age classes, and the rhizomes' potential population consisted of four age classes, of which the potential population formed by rhizomes accounted for 68.3% of the total potential population. The potential population produced by 1st age class tillers and rhizomes accounted for 60.2% of the total, which was the main part of the potential population composition and the main source of population renewal. The potential population of tillers was the most abundant in long-term mowing meadow. The potential population of rhizomes was the most abundant in enclosing sand-covered meadow. The vegetative fertility of tillers and rhizomes was the highest in young age. The vegetative fertility of rhizomes was 10.0 times as that of tillers, which dominated the vegetative reproduction of L. chinensis. The potential population composition of L. chinensis varied greatly across different habitats, reflecting the divergent adaptation to habitat variation.