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Shallow lake sediments have huge potential for carbon storage, but they are vulnerable to various environmental changes and are highly susceptible to becoming a source of carbon emissions. Understanding the amount of sediment carbon storage can provide information about the potential of shallow lakes in mitigating climate change. In this study, sediment sampling was conducted at 12 study sites in Chaohu Lake, China, and sediment water content, grain size, bulk density, and sediments organic carbon (SOC) content were examined in five layers along the vertical direction, respectively, and the distribution and storage of SOC were estimated. The results showed that the surface sediments in the west lake area of Chaohu Lake would release 66,300 t of SOC to the overlying water body in the future. The sediments in the middle lake area and the east lake area will absorb another 15,900 t and 17,300 t of TOC from the water body in the future, respectively. Overall, the lake-wide sediments will release 33,100 t of SOC into the water body in the future. In addition, the results of the study also indicate that human activities are another major influence on the change in organic carbon stocks in lake sediments, and therefore, proactive measures for the restoration and protection of lake sediments are essential because increasing the SOC stocks in the sediments and maintaining the lakes in a sustainable manner can contribute to the crucial role they play in mitigating climate change.

Available energy partitioning in the canopy and at the soil surface under the control of biophysical environment critically influences agricultural water resources management and the regional climate. Drip irrigation technology has been extensively promoted in arid regions and is gradually replacing conventional border irrigation technology, which alters the soil surface hydrothermal conditions and influences the available energy partitioning both in canopy and at the soil surface through biophysical processes. The water-saving effect of drip irrigation has been well studied previously, however, its biophysical controls of available energy partitioning in canopy and soil surface remain insufficiently understood. In this study, we made continuous comparative measurements in two maize fields with border irrigation and drip irrigation during the growing seasons in the period 2014–2018 by simultaneously using eddy covariance systems, sap flow gauges and micro-lysimeters. We found that drip irrigation increased transpiration by 10% and reduced soil evaporation by 40% during the partial canopy period, and these values decreased to 1% and 26%, respectively as the crop developed to complete canopy cover period. However, drip irrigation increased sensible heat fluxes both in canopy and soil surface by 93% and 46%, respectively during the partial canopy period, and by 10% and 231%, respectively during the complete canopy period. The soil moisture drives the discrepancy of available energy partitioning in both canopy and soil surface between two fields. Slow-release effect of the drip irrigation in replacing warm air in soil pores enhanced thermal convection in soil surface, small irrigation volume and small moisture area decreased evaporation loss, and frequent irrigation and sufficient soil moisture induced stable energy interaction between canopy and soil surface, therefore enhancing more sensible heat directed to canopy and soil surface in drip irrigated field. The results enhanced understanding of ecohydrology processes in agroecosystems and provided valuable information for agricultural water resource management.

Abstract Irrigation is the dominant section of human water use, exerting essential impacts on hydrological processes and water resources. To more realistically simulate irrigation processes in water‐rich regions, an irrigation scheme is incorporated into a land surface‐hydrological model. It calculates the irrigation water requirement according to meteorological conditions, cropping area and growing stage, and root‐zone soil moisture, and determines the irrigation water withdrawal based on the available water resources as well as describing water extraction and irrigation processes in the model. The coupled model is applied to the Yangtze River Basin (YRB) in China, and verified using the observed daily river discharge from 1987 to 1990, evapotranspiration and irrigation amounts from 1999 to 2003. The results first show that the model can well reproduce hydrological processes within the basin, and the simulated irrigation largely agrees with the observation, in terms of annual irrigation and its spatial pattern. Second, inclusion of irrigation processes allows the model to better estimate evapotranspiration, with relative biases decreased from about −10% to −3%. It is also found that in comparison to arid/semi‐arid areas, although presenting a less effect on river discharge and groundwater, the irrigation in the YRB significantly alters hydrological processes through water redistribution. The irrigation‐induced evapotranspiration increment and runoff decrease indicate a shift in the surface water and energy balance, implying a potential effect on the atmosphere. Therefore, representing irrigation processes properly is important, particularly for understanding the coupling effect of the nature‐human system and improving the hydrological prediction accuracy.

Abstract Background It is beneficial for society to discover the risk factors associated with surgery and to carry out some early interventions for patients with these risk factors. Few studies specifically explored the relationship between bone marrow lesions (BMLs) and long-term incident joint surgery. Objective To investigate the association between BML severity observed in knee osteoarthritis (OA) patients’ first MRI examination and incident knee surgery within 5 years. Additionally, to assess the predictive value of BMLs for the incident knee surgery. Design Retrospective cohort study. Methods We identified patients diagnosed with knee OA and treated at our institution between January 2015 and January 2018, and retrieved their baseline clinical data and first MRI examination films from the information system. Next, we proceeded to determine the Max BML grades, BML burden grades and Presence BML grades for the medial, lateral, patellofemoral, and total compartments, respectively. Multi-variable logistic regression models examined the association of the BML grades with 5-year incident knee surgery. Positive and negative predictive values (PPVs and NPVs) were determined for BML grades referring to 5-year incident knee surgery. Results Totally, 1011 participants (knees) were found eligible to form the study population. Within the 5 years, surgery was performed on 74 knees. Max BML grade 2 and grade 3 of medial, patellofemoral and total compartments were strongly and significantly associated with incident surgery. None of the BML grades from lateral compartment was associated with incident surgery. The PPV was low and NPV was high for BMLs. Conclusions BMLs found in the first MRI examination were associated with 5-year incident joint surgery, except for those allocated in lateral compartments. The high NPVs imply that patients without BMLs have a low risk of requiring surgery within 5 years.

ObjectiveTo investigate whether depression and exposure to anti-depressant medication are independent risk factors for incident knee surgery and opioid use in knee osteoarthritis (KOA) patients.MethodsWe identified all patients who visited our outpatient department and were clinically diagnosed with KOA between January 2010 and January 2018. We retrieved their demographic, clinical, and radiographic data from the database of our hospital. Next, we analyzed the effect of depression and anti-depressant medication on the incident knee surgery and opioid use in KOA patients.ResultsA total of 4,341 KOA patients were found eligible to form the study population. Incident knee surgery and opioid use for the purpose of treating osteoarthritis were observed in 242 and 568 patients, respectively. Incident knee surgery was significantly associated with age (OR [95%CI], 1.024 [1.009–1.039], P = 0.002), BMI (OR [95%CI], 1.090 [1.054–1.128], P < 0.001), baseline K-L grade 3 (OR [95%CI], 1.977 [1.343–2.909], P = 0.001), baseline K-L grade 4 (OR [95%CI], 1.979 [1.241–3.157], P = 0.004), depression (OR [95%CI], 1.670 [1.088–2.563], P = 0.019), and exposure to anti-depressant medication (OR [95%CI], 2.004 [1.140–3.521], P = 0.016). Incident opioid use was significantly associated with depression (OR [95%CI], 1.554 [1.089–2.215], P = 0.015) and exposure to anti-depressant medication (OR [95%CI], 1.813 [1.110–2.960], P = 0.017).ConclusionDepression and anti-depressant drug exposure were independently associated with incident knee surgery, highlighting the need for more attention on comorbid depression in KOA management.

ObjectiveThe objective of this study is to investigate whether alcohol exposure and specific alcoholic drinks are independent risk factors for incident knee surgery in knee osteoarthritis (KOA) patients.MethodsWe identified all patients who were clinically diagnosed as KOA between January 2010 and January 2018 in our outpatient department. Demographic, clinical, and radiographic data were collected from the database of our hospital. Next, we analyzed the association between alcohol consumption and incident knee surgery.ResultsA total of 4,341 KOA patients completed the current study and were included in the final analysis. Incident knee surgery for the purpose of treating osteoarthritis was observed in 242 patients. Incident knee surgery was significantly associated with age (OR [95%CI], 1.023 [1.009–1.039], P = 0.002), BMI (OR [95%CI], 1.086 [1.049–1.123], P < 0.001), baseline K-L grade 3 (OR [95%CI], 1.960 [1.331–2.886], P = 0.001), baseline K-L grade 4 (OR [95%CI], 1.966 [1.230–3.143], P = 0.005), 7.1–14 drinks per week (OR [95%CI], 2.013 [1.282–3.159], P = 0.002), >14 standard drinks per week (OR [95%CI], 2.556 [1.504–4.344], P = 0.001), and the most common alcoholic drink produced by pea (OR [95%CI], 3.133 [1.715–5.723], P < 0.001).ConclusionKOA patients who consumed more than seven standard drinks per week were at substantial risk of incident knee surgery. In addition, alcoholic drink produced by pea is also an independent risk factor.