38 research outputs found

    Soil degradation regulates the effects of litter decomposition on soil microbial nutrient limitation: Evidence from soil enzymatic activity and stoichiometry

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    Soil microorganisms could obtain energy and nutrients during litter decomposition with the help of soil extracellular enzymes. The litter types were among the most critical factors that affect soil extracellular enzyme activities. However, how litter types modulate the soil extracellular enzyme activity with grassland gradation is unclear. Here, we conducted a 240-day experiment of two different types of litter decomposition on soil extracellular enzyme activity and stoichiometry in different degraded grasslands. We found that C-acquiring enzyme activity and the enzyme stoichiometry of C/N were higher in Chloris virgata litter than in Leymus chinensis litter at lightly degraded level and C-acquiring enzyme activity in C. virgata was 16.96% higher than in L. chinensis. P-acquiring enzyme activity had the same trend with litter types in moderately and highly degraded levels and it was 20.71% and 30.89% higher in C. virgata than that in L. chinensis, respectively. The change of the enzyme stoichiometry with litter types was only showed in the enzyme stoichiometry of C/N at lightly degraded level, suggesting that litter types only affected the microbial C limitation in lightly degraded grassland. Almost all soil extracellular enzyme activities and extracellular enzyme stoichiometry, except the enzyme stoichiometry of N/P, decreased with grassland degraded level increasing. All vector angles were less than 45° suggesting that soil microorganisms were limited by N rather than by P during the decomposition process. Enzyme vector analysis revealed that soil microbial communities were co-limited by C and N during litter decomposition. Moreover, based on Random Forest (explaining more than 80%), we found that soil total nitrogen, total carbon, total phosphorus, dissolved organic C, pH and EC were important factors affecting soil enzyme activities by degradation levels. Our results emphasized that degradation levels could modulate the influences of litter types on soil extracellular enzyme activity. Our study enhanced our understanding in resource requirements for microbial communities to litter resources in degraded grassland and helped us to provide new ideas for improving degraded grassland ecosystems

    Stronger microbial nutrient limitations in subsoil along the precipitation gradient of agroecosystem: insights from soil enzyme activity and stoichiometry

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    IntroductionSoil extracellular enzymes are central in terrestrial ecosystem responses to climate change, and their research can be crucial for assessing microbial nutrient demand. However, the effects of climate-induced precipitation patterns on soil microbial nutrient demand in different soil profiles of agroecosystems are rarely studied.MethodsHere, we present how the precipitation gradient affects soil enzymes related to carbon (C), nitrogen (N) and phosphorus (P) cycling and identified microbial nutrient limitation determinants at five depth intervals (0–10, 10–20, 20–30, 30–40, and 40–50 cm) in seven agroecosystems.Results and DiscussionWe found that N- and P-acquiring enzymes have a tendency to decrease or increase, respectively, but C-acquiring enzymes did not change along the precipitation gradient throughout soil profiles. Soil pH and moisture were the most important factors affecting the enzyme activity in 0–50 cm. Our results also revealed a crucial soil boundary (at 20 cm) that differentiated responses of microbial nutrient limitation to precipitation changes. In the topsoil (0–20 cm), the stoichiometry of soil nutrients did not vary with precipitation. Microbial P limitation was exacerbated with increased precipitation, which was controlled by soil pH and moisture in the topsoil. In contrast, in the subsoil (20–50 cm), soil nutrient stoichiometry decreased with increasing precipitation, and microbial C and P limitation displayed a positive correlation with precipitation. Furthermore, microbial P limitation tended to be stronger in the subsoil than in the topsoil along the precipitation gradient. Microbial C and P limitation was regulated by the soil nutrients and their stoichiometry in the subsoil. Our study is an essential step in soil enzyme activity and stoichiometry response to precipitation in agroecosystems and provides novel insights into understanding microbial nutrient limitation mechanisms in soil profiles along the precipitation gradient

    The effects of weight loss and improved metabolic health status on the risk of non-alcoholic fatty liver disease—results from a prospective cohort in China

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    BackgroundThe impact of weight loss and/or improved metabolic status on the risk of non-alcoholic fatty liver disease (NAFLD) has yet to be determined.MethodsA total of 35,322 participants without NAFLD were followed. NAFLD risk was compared between consistently metabolically healthy non-obese (MHNO) and non-MHNO who lost weight to become non-obese and/or improved their metabolic health, using Cox proportional hazards and logistic regression models.ResultsFollowing 148,186 person-years, 8,409 participants had onset NAFLD, with an incidence rate of 56.75 (95% CI: 55.57, 57.94) per 1,000 person-years. Metabolically healthy obese (MHO), metabolically unhealthy obese (MUO), and metabolically unhealthy non-obese (MUNO) at baseline were associated with increased NAFLD risk, with hazard ratios of 4.48 (95%CI:4.24, 4.73), 8.85 (95%CI:7.95, 9.84), and 10.70 (95%CI:9.73, 11.78). Weight loss and/or metabolic status improvements could significantly reduce NAFLD risk by 79.46 to 41.46%. Specifically, after weight loss from MHO to MHNO, the reduction in NAFLD risk [OR decreased from 12.01 (95%CI:9.40, 15.35) to 4.14 (95%CI:3.08, 5.57)] was greater than that of the MUNO subgroup whose metabolic status improved to MHNO [OR decreased from 5.53 (95%CI:5.15, 5.94) to 2.71 (95%CI:2.50, 3.93)]. In the MUO subgroup, the group with the greatest risk reduction of NAFLD was the weight and metabolic state both improvement group [MUO to MHNO, OR decreased from 22.74 (95%CI:17.61, 29.37) to 4.67 (95%CI:3.05, 7.16)], followed by the weight loss only group [MUO to MUNO, OR decreased to 6.83 (95%CI:4.87, 9.57)], and finally the group with the least and insignificant risk reduction was the metabolic state improvement group [MUO to MHO, OR decreased to 13.38 (95%CI:9.17,19.53)]. NAFLD risk was negatively correlated with the duration of improvement (p < 0.001).ConclusionIndividuals with non-MHNO were more likely to develop NAFLD than those with consistent MHNO, but metabolic improvements and weight loss can alleviate the risk. Their NAFLD risk was negatively correlated with improvement duration. However, it remained higher than in individuals with consistent MHNO at an average follow-up of 4.2 years

    Dietary Corn Bran Altered the Diversity of Microbial Communities and Cytokine Production in Weaned Pigs

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    Corn bran (CB) has been used as an ingredient for pigs, but the underlying mechanisms that improve gut health is less clear. This study was conducted to investigate effects of dietary CB on growth performance, nutrient digestibility, plasma indices related to gut hormones and immunity, gut microbiota composition, and fermentation products in weaned pigs. A total of 60 weaned pigs were allocated to two dietary treatments, and piglets in each group received control (CON) diet or 5% CB diet for 28 days. Growth performance, nutrient digestibility, indices of gut hormones and immunity in plasma were evaluated. Microbiota composition in feces was determined using 16S rRNA amplicon sequencing, and fermentation products were measured by high-performance ion chromatography. The results showed that dietary CB did not affect growth performance, nutrient digestibility, gut hormones, or fermentation products in the trial (P > 0.05). There was an increased response to CB inclusion on interleukin-10 production (P < 0.05). On day 28, piglets fed dietary CB had a higher shannon index (P < 0.05). The population of the Firmicutes in CB treatment were decreased (P < 0.05), while the percentage of the Bacteroidetes were increased (P < 0.05). In particular, the populations of Eubacterium corprostanoligenes, Pevotella, and Fibrobacter related to polysaccharide fermentation of cereal bran were increased (P < 0.05). In conclusion, a post-weaning diet containing 5% CB increased intestinal microbial diversity, especially higher richness of fibrolytic bacteria, and promoted anti-inflammatory response to some extent in piglets, these changes should facilitate the adaptation of the digestive system of piglets in the subsequent growing phases

    Role of external forcing in the time-varying trends of global-mean surface temperature under current and future climates

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    The decadal-scale global-mean surface temperature (GMST) trend fluctuates between rapid-warming, slow-warming and cooling under the combined action of external forcing (EX) and internal variability. However, the principal contributors to the time-varying trends of GMST across decadal scales in current and future climates remain elusive. Here, by leveraging observations and initial-condition large ensembles, we unravel that historical GMST trend fluctuations are predominantly driven by EX on timescales exceeding ∼9 years within the current climate, with anthropogenic and volcanic aerosols being the primary drivers. However, in the warming climate, the significant contribution of EX on decadal scales is projected to decrease. This is primarily due to anthropogenic aerosol mitigation efforts and the absence of unpredictable volcanism. Despite the continuous increase in greenhouse gases, these factors are expected to delay the emergence of EX-dominance to ∼14-year timescale. Our results quantitatively underscore the pivotal role of the EX in modulating GMST trend fluctuations and its potential weakening at decadal scales in the warming climate, indicating that predicting near-term changes in GMST may become less certain in the future

    A Method for Evaluating User Interface Satisfaction Using Facial Recognition Technology and a PSO-BP Neural Network

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    User satisfaction serves as a crucial reference for iteratively optimizing software interface designs. This paper introduces a comprehensive measurement model of user satisfaction, employing Notability and Goodnotes for case studies. The proposed model incorporates facial recognition technology to gauge the intensity of users’ facial expressions while interacting with various functions of the target interface. Additionally, an experimental observation method is employed to gather objective data, including task completion time, task success rates, and operational procedures, alongside users’ subjective evaluations. Leveraging objective data as input and subjective ratings as output, a user satisfaction prediction model based on a PSO-BP neural network has been devised. The results demonstrate an impressive accuracy rate of 86.26%, indicating a high accuracy in subjective perception prediction. This model has proven to be effective for measuring user satisfaction and evaluating software interface usability. Moreover, this research contributes to expanding the repertoire of user interface satisfaction evaluation methods, enhancing the objectivity of measurements and surpassing the efficiency of conventional experimental evaluation techniques. The proposed model holds practical significance for software interface usability assessment and optimization design

    Nirvana: A Qualitative Study of Posttraumatic Growth in Adolescents and Young Adults with Inflammatory Bowel Disease

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    (1) Background: Psychosomatic discomfort is prevalent among adolescents and young adults (AYAs) with inflammatory bowel disease (IBD). Post-traumatic growth (PTG) has been a protective factor in earlier research. However, little is known regarding PTG among AYAs with IBD. This study investigates the generation of PTG in adolescents and young adults with inflammatory bowel disease (IBD) and finds positive coping skills employed in clinical nursing practice. (2) Methods: In 2021, 32 individuals were interviewed utilizing a semi-structured interview guide. This study used qualitative content analysis. (3) Results: The interviews revealed five themes: spiritual change, internalized supportiveness, cognitive re-shaping, externalized behaviors, and future-oriented thinking. (4) Conclusions: The research revealed the presence of PTG in AYAs with IBD. To give tailored care to patients, medical professionals must monitor the state of their PTG development in a planned and focused manner

    China’s Successful Recruitment of Healthcare Professionals to the Worst-Hit City: A Lesson Learned

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    The outbreak of coronavirus disease in 2019 (COVID-19) in Wuhan has led Chinese health authorities to recruit healthcare providers from the least-affected areas to provide care to the infected patients in Wuhan. We took further steps to explain some plausible reasons for their experiences. We used interpretative phenomenological analysis (IPA) to understand the subjective experiences, as well as the reasons for these experiences among the healthcare providers who had traveled from the least-affected parts of China to render aid during Wuhan’s COVID-19 outbreak. Using purposive and snowball sampling, healthcare professionals were recruited from three major hospitals in Jiangsu province. Semi-structured interviews were conducted from 1 September to 14 November 2020 in face-to-face contexts. Ten nurses and four doctors provided their informed consent for the study. The primary superordinate theme from the responses highlighted how social identity and individual needs were challenged by each individual’s professional ethics. COVID-19 not only presents significant risks to the health of nurses and medical doctors; it further challenges their emotional and psychosocial wellbeing. Care should be taken in allocating support and help, with the careful deployment of professional values and beliefs, so that any human resource as precious as medical doctors and nurses can be protected

    Gender Bias and the Lack of Equity in Pandemic Nursing in China: A Qualitative Study

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    There has long been a gender bias in medicine. This qualitative study aims to identify the experience of sexism among frontline female nurses and further explore their expectations and possible strategies to get rid of gender bias. This is a descriptive phenomenological study of 23 female nurses with 11 ± 3.98 years of experience who spent 36 ± 6.50 days at the frontline during the initial COVID-19 outbreak. We employed Colaizzi’s phenomenological analysis method to understand the subjective experiences, revealing the following themes: (a) materialization of gender identity; (b) incoordinate relationships; (c) future voice of female nurses. The gender bias experienced by female frontline nurses further challenges their emotional identity and self-identity. Therefore, it is important to require extensive consciousness-raising and policy support to defend female nurses’ rights

    Mediation effect of gut microbiota on the relationship between physical activity and carotid plaque

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    BackgroundPhysical activity has been shown to have an effect on Carotid plaque (CP) which is a predictor of Cardiovascular disease (CVD). Studies have shown that physical activity can alter the composition of gut microbiota, whether its influence on CP was mediated by gut microbiota has yet to be proved.MethodsWe conducted a case–control study involving 30 CP patients and 31 controls. Logistic regression was used to analyze the association between CP and physical activity. LefSe was used to explore the association between gut microbiota and physical activity as well as CP, and PhyloMed was used to examine the mediating effect of gut microbiota in the association between physical activity and CP.ResultsAfter adjusting for potential confounders, adequate physical activity showed a significant association with a decreased risk of CP (ORadj: 0.25, 95%CI: 0.06, 0.97). CP was associated with enrichment in the order Bacteroidales within the phylum Bacteroidetes and the predominant microbiota in individuals without plaque was the order Clostridiales (LDA scores >3). Individuals with adequate physical activity had a higher abundance of the order Clostridiales, while the order Bacteroidetes was enriched in individuals with inadequate physical activity (LDA scores >3). The PhyloMed revealed a significant mediation effect of gut microbiota in the association between physical activity and CP (p = 0.03).ConclusionAdequate physical activity was significantly associated with a decreased risk of CP, and this association was mediated by an increase in the abundance of gut microbiota in the order Clostridiales
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