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Background: Long working hours and effort-reward imbalance (ERI) among medical workers may contribute to poor mental health and reduced productivity. However, the potential mechanisms among them are not well understood. This study aimed to explore the role of depressive symptoms and ERI in the relationship between long working hours and presenteeism among village doctors. Methods: We conducted a cross-sectional study in Jiangsu Province, eastern China. 705 village doctors were assessed for working hours, ERI (the Effort-Reward Imbalance Questionnaire, ERI questionnaire), presenteeism (6-item Stanford Presenteeism Scale, SPS-6 Scale), and depressive symptoms (12-item General Health Questionnaire, GHQ-12). A moderated mediation model was used to test the role of depressive symptoms (M), and ERI (W) in the relationship between long working hours (X) and presenteeism (Y). Results: 45.11% of the village doctors worked more than 55 h per week, and 55.89% were exposed to ERI. The prevalence of depressive symptoms among Chinese village doctors was 40.85%. Long working hours (≥ 55 h per week) were significantly associated with presenteeism behaviors (β = 2.17, P < 0.001). Mediation analysis demonstrated that depressive symptoms (GHQ score > 3) could partly mediate the relationship between long working hours and presenteeism (indirect effect β = 0.64, P < 0.001). Moderated mediation further indicated that the interaction of long working hours and ERI was significantly and positively associated with depressive symptoms, which in turn predicted elevated presenteeism behaviors. Conclusions: Depressive symptoms had a mediating role in the association of long working hours with presenteeism behaviors among Chinese village doctors and ERI augment their negative effects. [ABSTRACT FROM AUTHOR]

• Using biomanipulation to restore a eutrophic highland lake in subtropical China was tested. • Fish removal led to increased abundance of cladoceran (Daphnia spp., especially Bosmina spp.). • Enhanced top-down control was found leading to lower phytoplankton and cyanobacterial biomass. • Fish removal may be a feasible additional restoration tool to nutrient loading reduction such lakes. Removal of planktivorous fish is used extensively in northern temperate lakes to reduce phytoplankton abundance via enhanced zooplankton grazing. However, whether this method would work also in large subtropical highland lakes to alleviate cyanobacterial blooms is unknown. We conducted a one-year pilot in situ experiment where we removed a substantial biomass of fish in a fenced-in area, followed by a 3-year whole-lake experiment where the dominant fish species (Japanese smelt) was removed in Lake Erhai in southwest China. The fencing experiments showed that between July and November, when the biomass of the removed stock reached 4 g/m2, the zooplankton biomass inside the fence increased significantly compared to a control fence. In the full-lake experiment, we found that sustained removal of Japanese smelt led to an increase in the biomass of cladocerans (Daphnia spp. but especially of Bosmina spp.) and a significant decrease in the biomass of Cyanobacteria and Chlorophyta. Additionally, a marked increase in the ratio of zooplankton to phytoplankton biomass, as well as an increase in the body size of cladocerans, emphasising the importance of enhanced top-down control for mitigating cyanobacterial blooms following extensive fish removal. Our results reveal that removal of small fish (here Japanese smelt) can lead to a reduction of the phytoplankton and cyanobacteria biomass through a trophic cascade in highland deep subtropical lakes. Thus fish removal may be a feasible additional restoration tool to external nutrient loading reduction in such lakes. [Display omitted] [ABSTRACT FROM AUTHOR]

Introductions or alien species invasions will induce changes in aquatic ecosystems but are rarely reported in Chinese highland lakes. The Japanese smelt (Hypomesus nipponensis) invaded and has become a dominant fish species in Lake Erhai, a highland lake in southwestern China, since 2016. Here, we engineered Ecopath models for two different periods, 2008–2009 (preinvasion) and 2016–2018 (postinvasion), in Lake Erhai to model ecosystem impacts from the Japanese smelt invasion. In the dynamic Ecosim model based on the 2016–2018 Ecopath model, we ran three 50-year scenarios to simulate the potential effects of Japanese smelts on the system. Our results showed competition between invasive and native species as well as changes in trophic structures, highlighting the impacts of the invasive species over time. The lake ecosystem additionally experienced significant degradation after invasion, mainly reflected in several related indicators, such as total biomass/total system throughput (TB/TST), total primary production/total biomass (TPP/TB), total primary production/total respiration (TPP/TR), Finn's mean path length (FML), Finn's cycling index (FCI) and the Connectance Index (CI). The simulation results indicated that the relative biomass of icefish (Neosalanx taihuensis), bighead carp (Hypophthalmichthys nobilis), sharpbelly (Hemiculter leucisculus), and zooplankton were significantly affected by increasing the strength of the top-down control of the Japanese smelt on its prey. It is also important to do ecological regulation of planktivorous fishes in the studied Lake Erhai, especially the Japanese smelt. • Ecosystem impact of invasive Japanese smelt in Lake Erhai was studied. • Food web models were developed before and after the fish invasion. • Invasive fish reduced zooplankton biomass, whereby affected others fish by food webs. • It is also important to do ecological regulation of Japanese smelt in Lake Erhai. [ABSTRACT FROM AUTHOR]

The introduction of non-native fish species is known to have adverse effects on aquatic ecosystems, but their effect on plateau lakes is not well studied. In this study, we examined the effect of the Japanese smelt (Hypomesus nipponensis) invasion on the fish assemblage in Lake Erhai, a subtropical plateau lake in southwestern China. Through cluster analysis and non-metric multidimensional scaling (NMDS), we found a significant fish assemblage shift: the population of sharpbelly (Hemiculter leucisculus) fell by 67% in catch per unit effort (CPUE) from 2.262 to 0.741; topmouth gudgeon (Pseudorasbora parva) fell by 52% from 0.61 to 0.29; and icefish (Neosalanx taihuensis) plummeted by 88% from 0.736 to 0.088. Meanwhile, the numbers for crucian carp (Carassius auratus) improved by almost 185% from 1.82 to 3.36. A Pearson correlation analysis showed that these four species significantly correlated with the invasion of the Japanese smelt: sharpbelly (−0.71), topmouth gudgeon (−0.71), icefish (−0.62), and crucian carp (0.81). This study documented the expansion of invasive fish and their effects on native species over time, thus providing a case study of invasive fish as well as a theoretical basis for further research into interspecies interactions. [ABSTRACT FROM AUTHOR]

Background: As stroke has become the leading cause of death and disability in China, it has induced a heavy disease burden on society, families, and patients. Despite much attention within the literature, the effect of multiple risk factors on length of stay (LOS) and inpatient costs in China is still not fully understood., Aim: To analyse the association between the number of risk factors combined and inpatient costs among adults with stroke and explore the mediating effect of LOS on inpatient costs., Methods: A retrospective cross-sectional study was conducted among stroke patients in a tertiary hospital in Nantong City from January 2018 to December 2019. Lifestyle factors (smoking status, exercise), personal disease history (overweight, hypertension, dyslipidemia, diabetes mellitus, atrial fibrillation), family history of stroke, and demographic characteristics were interviewed by trained nurses. Inpatient costs and LOS were extracted from electronic medical records. Hierarchical multiple linear regression models and mediation analysis were used to examine the direct and indirect effects of the number of risk factors combined for stroke on inpatient costs., Results: A total of 620 individuals were included, comprising 391 ischaemic stroke patients and 229 haemorrhagic stroke patients, and the mean age was 63.2 years, with 60.32% being male. The overall mean cost for stroke inpatients was 30730.78 CNY ($ 4444.91), and the average length of stay (LOS) was 12.50 days. Mediation analysis indicated that the greater number of risk factors was not only directly related to higher inpatient costs (direct effect = 0.16, 95%CI:[0.11,0.22]), but also indirectly associated with inpatient cost through longer LOS (indirect effect = 0.08, 95% CI: [0.04,0.11]). Furthermore, patients with high risk of stroke had longer LOS than those in low-risk patients, which in turn led to heavier hospitalization expenses., Conclusions: Both the greater number of risk factors and high-risk rating among stroke patients increased the length of stay and inpatient costs. Preventing and controlling risk behaviors of stroke should be strengthened., (© 2024. The Author(s).)