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Mild cognitive impairment (MCI) is a condition that impairs activities of daily living, and often transforms to dementia. Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) show promise in improving cognitive functions in MCI patients. In this meta-analysis, we aimed to compare the effects of rTMS and tDCS on memory functions in MCI patients. We explored eight databases from their inception to March 16, 2024. We obtained 11 studies with 406 patients with MCI. We used the standardized mean difference (SMD) with a 95% confidence interval (CI) to synthesize the effect size. rTMS and tDCS significantly improved memory functions in MCI patients (SMD = 0.61; 95% CI: 0.41–0.82; p

Ship piping arrangement is a nondeterministic polynomial problem. Based on the advantages of the grey wolf optimization (GWO) algorithm, which is simple, easy to implement, and has few adjustment parameters and fast convergence speed, the study adopts the grey wolf optimization (GWO) algorithm to solve the ship piping arrangement problem. First, a spatial model of ship piping arrangement is established. The grid cell model and the simplified piping arrangement environment model are established using the raster method. Considering the piping arrangement constraint rules, the mathematical optimization model of piping arrangement is constructed. Secondly, the grey wolf optimization algorithm was optimized and designed. A nonlinear convergence factor adjustment strategy is adopted for its convergence factor. Powell’s algorithm is introduced to improve its local search capability, which solves the problem that the grey wolf algorithm easily falls into the local optimum during the solving process. Simulation experiments show that compared with the standard grey wolf algorithm, the improved algorithm can improve the path layout effect by 38.03% and the convergence speed by 36.78%. The improved algorithm has better global search ability, higher solution stability, and faster convergence speed than the standard grey wolf optimization algorithm. At the same time, the algorithm is applied to the actual ship design, and the results meet the design expectations. The improved algorithm can be used for other path-planning problems.

Vegetation change has a non-negligible role in the impact of ecosystem services (ESs). Quantitative assessment of vegetation ecosystem services is the basis for sustainable regional development. Using the Chinese Loess Plateau (LP) as the study area, this study firstly analysed the spatial and temporal characteristics of vegetation change and used a Geodetector model to reveal the driving mechanism. Next, this study applied the InVEST model to quantitatively assess the four services of carbon storage, habitat quality, soil conservation and water yield, and explored the vegetation ecosystem service balance through vegetation type transfer. The results showed that (1) there was a trend towards an increase in the area of all vegetation types, with sparse vegetation being the most pronounced. Areas of damaged vegetation were concentrated in urban and peripheral areas, as well as wasteland and bare ground. (2) Annual precipitation, soil types and cumulative afforestation area ratio were the main drivers of vegetation change on the LP. (3) Restoration of woodland enhanced carbon storage, habitat quality and soil retention services for vegetation on the LP, while water yield decreased by 31.66%. The restoration of vegetation area did not enhance all ecosystem services. This study may provide a reference and basis for the sustainable management of regional ecosystems.

Accumulation of vegetation biomass is a crucial process for carbon fixation in the early stage of afforestation and a primary driving force for subsequent ecological functions. Accurately assessing the storage and allocation of elements in plantations is essential for their management and estimating carbon sink capacity. However, current knowledge of the storage and allocation patterns of elements within plant organs at the community level is limited. To clarify the distribution patterns of elements in plant organs at the community level, we measured the biomass within plant organs of five typical plantations in the early stage of afforestation in the loess hilly-gully region. We assessed the main drivers of element accumulation and distribution by employing redundancy analysis and random forest. Results revealed significant differences in biomass storages among plantations and a significant effect of plantation type on the storages of elements within plant organs. Furthermore, the dominant factors influencing C–N–P storage and allocation at the community level were found to be inconsistent. While the storage of elements was mainly influenced by stand openness, total soil nitrogen, and plant diversity, the allocation of elements in organs was mainly influenced by stand openness and soil water content. Overall, the spatial structure of the community had an important influence on both element storage and allocation, but soil conditions played a more important role in element allocation than in storage. Random forest results showed that at the community level, factors influencing element storage and allocation within plant organs often differed. The regulation of elemental storage could be regulated by the major growth demand resources, while the allocation was regulated by other limiting class factors, which often differed from those that had a significant effect on element storage. The differences in plant organ elemental storage and allocation drivers at the community level reflect community adaptation strategies and the regulation of resources by ecosystems in combination with plants. Our study provides valuable insights for enhancing plantation C sink estimates and serves as a reference for regulating element storage and allocation at the local scale.

The forest ecosystem is the ecosystem with the largest terrestrial carbon pool in the world. Afforestation, cutting and tending mutually affect the forest carbon source and the carbon sink. However, few studies have explored the effects of larch plantation management on soil aggregate stability and soil aggregate carbon storage. The effects of the four thinning intensities (unmanaged control (CK), 15% reduction, mild thinning (LT), 30% reduction, intermediate thinning (MT), and 50% reduction, severe thinning (HT)) on soil aggregate stability and carbon storage were investigated in Larix principis-rupprechtii plantations in North China. The results showed that soil aggregates with a particle size of >2 mm or 1–2 mm under all thinning intensities were the most abundant. At the same time, organic carbon and labile carbon were mainly distributed in >0.25 mm soil aggregates. The MT treatment corresponded with the highest organic carbon and labile carbon levels. The distribution of soil macro aggregates was greatly affected by stand density, while the distribution of micro aggregates was most affected by nutrient-related factors. Forest thinning reduces the stability of soil aggregates, though intermediate thinning can improve the carbon sequestration potential of soil aggregates. These findings will provide essential evidence for carbon sequestration of soil aggregates in plantations after thinning, and provide reference for those formulating plantation management strategies in North China.

Nitrogen (N), phosphorus (P), and potassium (K) play an essential role in plant growth, development and reproduction. The pattern of nutrient stoichiometry across various plant organs and plant life forms can reflect the trade-off of plant growth strategies. However, there is a lack of systematic research on plant nutrient stoichiometry and the influence of environmental factors. Therefore, the main forest type Quercus wutaishanica community was considered as the object for this study and samples of different life forms (trees, shrubs, herbs) and different organs (leaves, stems, roots, seeds) were collected in northern China. First, we analyzed N/P/K stoichiometry among different organs and different life forms in the Quercus wutaishanica natural community. Second, we explored the influence of environmental factors on N/P/K stoichiometry and clarified the relative contributions of variables among different life forms. The results showed that the distributions of nutrient stoichiometry in different life forms and organs were different. As the most active organ, the content of elements in leaves was significantly higher than that in other organs. Among them, P was the main limitation in leaves and roots; N was the main limitation in stems and seeds in this area. Environmental factors had different effects on the N/P/K stoichiometry of different life forms. The nutrient stoichiometry in trees was mainly affected by topographical factors; the nutrient stoichiometry in shrubs and herbs was mainly affected by soil factors. Therefore, the differences in N, P, and K stoichiometry may be caused by the growth environment and the plant’s own adaptation strategies. All of these studies provide new insight for studying the homeostasis system within plants and communities by means of stoichiometry. This study is expected to guide the management and protection of the natural community, make the natural community give more ecological functions, and provide support for the cultivation of artificial forests in the future.