Suchergebnisse

AbstractIn this study, 15 sampling sites were set up in Dongting Lake, a typical river-connected lake in China, to investigate water quality and diatioms in March, June, September and December from year 2017 to 2022. Seven diatom indices, including relative abundance of diatoms (RAD), percentage motile diatoms (PMD), generic diatom index (GDI), diatom quotient (DU), pollution tolerance index for diatoms (PTI), trophic diatom index (TDI), and Pampean diatom index (IDP), were selected to screen the adaptability of water quality assessment comparing with the Nemero index (NI), which is simple to calculate and has always been the main method for water quality assessment in Dongting Lake. The results from 2017 to 2019 showed that the diatom density in Dongting Lake ranged from 0.7 × 104 to 85.5 × 104 ind./L, with a certain decreasing trend. The spatial and temporal changes of some water quality factors were obvious, just like the temperature of water (WT), ammonia nitrogen (NH4+–N), dissolved oxygen (DO) and the comprehensive trophic level index (∑TLI) ranged from 45.99 to 50.72, with an average value of 47.85, indicating that the overall condition of Dongting Lake was medium nutrition. Correlation analysis showed that PTI, RAD and PMD could represent the information of DU, GDI, TDI and IDP, and were significantly positively correlated with DO (p < 0.01), while significantly negatively correlated with electrical conductivity (Cond), potassium permanganate (CODMn), biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr) and ∑TLI (p < 0.001). The index verification results from year 2020 to 2022 showed that PTI, RAD and PMD were all significantly positively correlated with NI (p < 0.001). Taking into account the data integrity of the index calculation and the difficulty degree, RAD was finally selected as the biological indicator for evaluating the water quality of Dongting Lake. The results of this study provide a new path or alternative method for water quality assessment of the river-connected lakes.

PurposeDrawing on social network and information diffusion theories, the authors study the impact of the structural characteristics of a seller's local social network on her promotion effectiveness in social commerce.Design/methodology/approachThe authors define a local social network as one formed by a focal seller, her directly connected users and all links among these users. Using data from a large social commerce website in China, the authors build econometric models to investigate how the density, grouping and centralization of local social networks affect the number of likes received by products posted by sellers.FindingsLocal social networks with low density, grouping and centralization are associated with more likes on sellers' posted products. The negative effects of grouping and centralization are reduced when density is high.Originality/valueThe paper deepens the understanding of the determinants of social commerce success from a network structure perspective. In particular, it draws attention to the role of sellers' local social networks, forming a foundation for future research on social commerce.

As it is the second-largest freshwater lake downstream of the Three Gorges Dam and an important international wetland for migratory birds, there have been concerns about the ecological water health of Dongting Lake for a long time. In the present study, we studied the evolutionary characteristics of water quality in Dongting Lake in three recent years. Moreover, the evolution rules and dominant groups of the phytoplankton community were explored, and the major influencing factors of phytoplankton and their distribution were assessed based on the field survey and detection data from 2017 to 2019. The results indicated that the water quality of Dongting Lake improved in recent years. The concentration of dissolved oxygen (DO) increased by 6.91%, whereas the concentrations of the five-day biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), ammonia nitrogen (NH4+–N), total phosphorus (TP), and total nitrogen (TN) decreased by 17.5%, 13.0%, 33.8%, 7.6%, and 13.3%, respectively. The mean phytoplankton density reached 4.15 × 105 cells·L−1 in September 2017, whereas it was only 1.62 × 105 cells·L−1 in December 2018. There were 15 dominant species belonging to Cyanobacteria, Chlorophyta, Bacillariophyta, Cryptophyta, and Miozoa. Moreover, Fragilaria radians (Kützing) D.M.Williams & Round and Aulacoseiragranulata (Ehrenberg) Simonsen were the dominant populations in all seasons. The Pearson and linear regression analysis also indicated that the composition and distribution of phytoplankton in Dongting Lake were mainly affected by electrical conductivity (Cond), BOD5, potassium permanganate (CODMn), and CODCr, especially in Eastern Dongting Lake. Of course, NH4+–N, TN, and TP were also the main factors affecting the density and species of the phytoplankton community, especially in Western Dongting Lake. Finally, we suggested that local government could take "The relationship between Yangtze River and Dongting Lake", "The relationship between the seven fed rivers and Dongting Lake", and "The relationship ...

Abstract

Aims
To identify and group hospitalization trajectory of alcohol use disorder (AUD) patients and its associations with service utilization, healthcare quality and hospital-level variations.


Methods
Inpatients with AUD as the primary diagnosis from 2012 to 2014 in Beijing, China, were identified. Their discharge medical records were extracted and analyzed using the sequence analysis and the cluster analysis.


Results
Eight-hundred thirty-one patients were included, and their hospitalization patterns were grouped into four clusters: short stay (n = 565 (67.99%)), mean psychiatric length of stay in 3 years: (32.25 ± 18.69), repeated short stay (n = 211 (25.39%), 137.76 ± 88.8 days), repeated long stay (n = 41 (4.93%), 405.44 ± 146.54 days), permanent stay (n = 14 (1.68%), 818.14 ± 225.22 days). The latter two clusters (6.61% patients) used 37.26% of the total psychiatric hospital days and 33.65% of the total psychiatric hospitalization expenses. All the patients in the permanent stay cluster and 41.77% of the patients in the short stay cluster were readmitted at least once within 3 years. Two-hundred thirty-four patients (28.16%) were admitted at least once for non-psychiatric reasons, primarily for diseases of circulatory and digestive systems. Cluster composition varied significantly among different hospitals.


Conclusion
Hospitalization pattern of patients with AUD varies greatly, and while most (&gt;2/3) hospitalizations were short stay, those with repeated long stay and permanent stay used more than one third of the hospital days and expenses. Our findings suggest interventions targeting at certain patients may be more effective in reducing resource utilization.