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Ecological theory posits that temporal stability patterns in plant populations are associated with differences in species ecological strategies. However, empirical evidence is lacking about which traits, or trade-offs, underlie species stability, especially across different biomes. We compiled a worldwide collection of long-term permanent vegetation records (greater than 7000 plots from 78 datasets) from a large range of habitats which we combined with existing trait databases. We tested whether the observed inter-annual variability in species abundance (coefficient of variation) was related to multiple individual traits. We found that populations with greater leaf dry matter content and seed mass were more stable over time. Despite the variability explained by these traits being low, their effect was consistent across different datasets. Other traits played a significant, albeit weaker, role in species stability, and the inclusion of multi-variate axes or phylogeny did not substantially modify nor improve predictions. These results provide empirical evidence and highlight the relevance of specific ecological trade-offs, i.e. in different resource-use and dispersal strategies, for plant populations stability across multiple biomes. Further research is, however, necessary to integrate and evaluate the role of other specific traits, often not available in databases, and intraspecific trait variability in modulating species stability.

The stability of ecological communities is critical for the stable provisioning of ecosystem services, such as food and forage production, carbon sequestration, and soil fertility. Greater biodiversity is expected to enhance stability across years by decreasing synchrony among species, but the drivers of stability in nature remain poorly resolved. Our analysis of time series from 79 datasets across the world showed that stability was associated more strongly with the degree of synchrony among dominant species than with species richness. The relatively weak influence of species richness is consistent with theory predicting that the effect of richness on stability weakens when synchrony is higher than expected under random fluctuations, which was the case in most communities. Land management, nutrient addition, and climate change treatments had relatively weak and varying effects on stability, modifying how species richness, synchrony, and stability interact. Our results demonstrate the prevalence of biotic drivers on ecosystem stability, with the potential for environmental drivers to alter the intricate relationship among richness, synchrony, and stability.

The current study aimed to explore the relationship between social support and the mental health of caregivers in nursing homes, as well as the moderating effect of general self-efficacy and the mediating effect of psychological resilience. A total of 398 caregivers were randomly selected from twelve nursing homes in China, and questionnaires concerning social support, general self-efficacy, psychological resilience and mental health were done. The results showed that: (1) social support significantly predicted the mental health of caregivers in nursing homes; (2) general self-efficacy moderated the relationship between social support and the mental health of caregivers in nursing homes; and (3) psychological resilience completely mediated the moderating effects of general self-efficacy on the relationship between social support and the mental health of caregivers in nursing homes. The findings of the current study indicated that enhancing the general self-efficacy and the psychological resilience of caregivers in nursing homes could effectively maintain their mental health. Finally, the theoretical contribution and practical significance of the current study were discussed., Author(s): Zijing Hong [sup.1] , Wei Zhou [sup.1] , Minghua Song [sup.2] , Yuting Wang [sup.1] , Shen Liu [sup.3] , Lin Zhang [sup.1] Author Affiliations: (1) grid.203507.3, 0000 0000 [...]

In the complex and harsh environment of agriculture, rolling bearings, as the key transmission components in agricultural machinery, are very prone to failure, so research on the intelligent fault diagnosis of agricultural machinery components is critical. Therefore, this paper proposes a new method based on SVD-EDS-GST and ResNet-Vision Transformer (ResViT) for the fault diagnosis of rolling bearings in agricultural machines. Firstly, an experimental platform for rolling bearing failure in agricultural machinery is built, and one-dimensional vibration signals are obtained using acceleration sensors. Next, the signal is preprocessed for noise reduction using singular value decomposition (SVD) combined with the energy difference spectrum (EDS) to solve for the interference of complex noise and redundant components in the vibration signal. Secondly, generalized S-transform (GST) is used to process vibration signals into images. Then, the ResViT model is proposed, where the ResNet34 network is used to replace the image chunking mechanism in the original Vision Transformer model for feature extraction. Finally, an improved Vision Transformer (ViT) is utilized to synthesize global and local information for fault classification. The experimental results show that the proposed method's average accuracy in rolling bearing fault classification for agricultural machinery reaches 99.08%. In addition, compared with SVD-EDS-GST-CNN, SVD-EDS-GST-LSTM, STFT-ViT, GST-ViT, and SVD-EDS-GST-ViT, the accuracy rate was improved by 3.5%, 3.84%, 4.8%, 8.02%, and 0.56%, and the standard deviation was also minimized. [ABSTRACT FROM AUTHOR]

A community functional structure may respond to environmental changes such as nitrogen (N) enrichment by altering intraspecific and interspecific trait variations. However, the relative contributions of both components in determining the community response to N enrichment are unclear. In this study, we measured the plant height (H), leaf area (LA), leaf dry matter content (LDMC), and specific leaf area (SLA) based on a nine-year N addition gradient experiment in an alpine meadow on the Tibetan Plateau. We examined the intraspecific and interspecific variations within and among the communities, the responses of traits in terms of community weighted mean (CWM) and non-weighted mean (CM) to N addition, and the effects of these trait variations on aboveground net primary productivity (ANPP). Our results show that N addition increased the interspecific variation in H while decreasing that of LA within the community, whereas it had no significant effects on the intraspecific variations in the four traits within the community. In contrast, N addition significantly increased the intraspecific variation in H and decreased that of LA among the communities. Moreover, the contribution of intraspecific variation was greater than that of the interspecific variation in terms of CWM for all traits, while the opposite contribution was observed in terms of CM, suggesting that the dominant species would have greater resilience while subdominant species would become less resistant to N addition. Further, intraspecific variations of LA and LDMC within the community played an important role in explaining community productivity. Our results highlight the importance of both intraspecific and interspecific variations in mediating functional trait responses to N enrichment, and intraspecific variation within the communities has important implications for community functioning that should be considered to better understand and predict the responses of the alpine grasslands to N enrichment. [ABSTRACT FROM AUTHOR]

In the field of statistical physics, unidirectional motion of a large number of particles along a single track can be described by totally asymmetric simple exclusion process (TASEP), from which many meaningful properties, such as the appearance of domain wall (defined as the borderline of high particle density and low particle density along the motion track) and boundary layers, can be obtained. However, it is biologically general that a single track may be occupied by different particle species. For example, in cells each microtubule protofilament is usually occupied by different species of motor protein. So previous studies about TASEP that included only one particle species may not be reasonable enough to describe more detailed properties of particle motion processes in a real cell environment. To address this problem, TASEP including two particle species is discussed in this study. Theoretical methods to get particle densities of each species are provided. By which, phase transition related properties of particle densities are obtained. Our analysis shows that domain wall and boundary layers of single species densities always appear simultaneously with those of the total particle density. The height of the domain wall of total particle density is equal to the summation of those of single particle species. Phase diagrams for typical model parameters are also presented. The methods presented in this study can be generalized to analyze TASEP with more particle species. Key words: two-species TASEP, domain wall, boundary layer, molecular motor, phase transition. En physique statistique, le mouvement unidirectionnel d'un grand nombre de particules le long d'une seule trajectoire peut etre decrit par un processus d'exclusion simple totalement asymetrique (PESTA/TASEP). A partir de la nous pouvons obtenir plusieurs proprietes significatives, comme le mur de domaine (defini comme la frontiere entre la haute densite de particules et la basse densite le long de la trajectoire du mouvement) et les couches limites. Cependant, on trouve generalement en biologie qu'une trajectoire simple peut etre occupes par differentes especes de particules. Par exemple, dans les cellules, chaque proto-filament de microtubule est generalement occupe par differents types de proteines moteurs. C'est pourquoi certaines etudes anterieures sur PESTA incluant une seule espece de particules peuvent etre mal adaptees aux proprietes detaillees des mouvements des particules dans l'environnement d'une vraie cellule. Pour corriger ce probleme, nous etudions ici un procede PESTA qui inclut deux especes de particules. Nous donnons les methodes pour les densites de particules des deux especes, a partir desquelles on obtient les proprietes reliees aux transitions de phase des densites des particules de chaque espece. Notre analyse montre que le mur de domaine et les couches limites des densites d'une seule espece apparaissent simultanement avec ceux de la densite totale. Nous presentons les diagrammes de phase pour des parametres de modele typiques. Les methodes presentees ici peuvent etre generalisees pour analyser PESTA avec plus d'especes de particules. [Traduit par la Redaction] Mots-cles : PESTA a deux especes, mur de domaine, couche limite, moteur moleculaire, transition de phase., 1. Introduction In the last decades, several theoretical models have been developed to describe the unidirectional motion of a large number of particles, including the motion of motor proteins along [...]