Search Results (7)

Soil organic carbon (SOC) and total nitrogen (TN) are fundamental indicators of soil fertility and long-term agricultural sustainability. However, intensive cultivation, residue removal, and imbalanced fertilization have resulted in substantial declines in SOC and TN across many agroecosystems, particularly in Northeast China. This study investigated SOC and TN dynamics within the 0–35 cm profile of four representative soils in Northeast China under a continuous maize cropping system. Five treatments were assessed: conventional tillage (CT), deep tillage (DT), deep tillage with straw (SDT), deep tillage with organic fertilizer (MDT), and deep tillage combined with straw and organic fertilizer (SMDT). Compared with DT, organic amendment treatments increased SOC and TN contents in the 0–20 cm layer by 9.41–57.57% and 5.29–60.76%, respectively. The SMDT treatment achieved the highest SOC and TN stocks (65.03 Mg ha⁻¹ and 7.91 Mg ha⁻¹) and enhanced nutrient accumulation in the 20–35 cm layer. In the subsoil, the ratio of soil C and N (C/N) under SMDT increased by 3.11%, 11.08%, 2.10%, and −7.01% across the four soils, indicating improved C–N balance and reduced nutrient stratification. SOC and TN stocks were linearly correlated with cumulative C input, confirming that organic amendments were among the main drivers of C and N sequestration. Mantel and path analyses further revealed that clay content and mean annual precipitation enhanced SOC and TN storage by improving soil structure and C–N balance through increased C input and reduced bulk density. Overall, deep tillage combined with amendments strengthened C–N coupling, improved soil fertility, and provided a mechanistic basis for reconstructing fertile tillage layers and sustaining productivity in Northeast China. Full article

As the fundamental unit of soil structure, soil aggregates play a crucial role in enhancing soil carbon and nitrogen storage, thereby supporting soil fertility and overall health, particularly in fragile karst regions. This study aims to quantify the effects of various ecological construction measures on soil aggregate stability, including focusing on geometric mean diameter (GMD), mean weight diameter (MWD), and K values, as well as aggregate-related organic carbon (SOC) and total nitrogen (TN), soil mechanical composition, and aggregate content. The ecological construction measures examined include plantation forests (Y7th–rgl), restored forests (Y6th–zr), fruit forests (Y6th–jgl), and contour reverse slope terraces (Y1th–crt). Compared to sloping farmland, contour reverse slope terraces, with their distinctive priority induction function, significantly increased the content of medium-fine particle aggregates, greater than 87%. Among the ecological construction measures, plantation forests exhibited the highest aggregate stability, with an average increase ranging from 8% to 157%. Notably, microaggregates, regardless of size, possessed the highest carbon and nitrogen contents, contributing significantly to soil carbon and nitrogen pools. Furthermore, both plantation and contour reverse slope terrace treatments demonstrated an equal contribution of carbon and nitrogen across all aggregate sizes. The partial least squares path modeling (PLS-PM) analysis indicates that land use type and the content of carbon and nitrogen pools are the primary factors influencing soil aggregate stability. These findings suggest that plantations are particularly effective in enhancing soil and water conservation in fragile karst areas, while the contour reverse slope terrace method shows potential for stabilizing soil structure over extended time scales due to its unique “preferential entrainment” function. Full article

Traumatic brain injury (TBI), a major global health burden, disrupts the neurological system due to accidents and other incidents. While the Glasgow coma scale (GCS) gauges neurological function, it falls short as the sole predictor of overall mortality in TBI patients. This highlights the need for comprehensive outcome prediction, considering not just neurological but also systemic factors. Existing approaches relying on newly developed biomolecules face challenges in clinical implementation. Therefore, we investigated the potential of readily available clinical indicators, like the blood urea nitrogen-to-albumin ratio (BAR), for improved mortality prediction in TBI. In this study, we investigated the significance of the BAR in predicting all-cause mortality in TBI patients. In terms of research methodologies, we gave preference to machine learning methods due to their exceptional performance in clinical support in recent years. Initially, we obtained data on TBI patients from the Medical Information Mart for Intensive Care database. A total of 2602 patients were included, of whom 2260 survived and 342 died in hospital. Subsequently, we performed data cleaning and utilized machine learning techniques to develop prediction models. We employed a ten-fold cross-validation method to obtain models with enhanced accuracy and area under the curve (AUC) (Light Gradient Boost Classifier accuracy, 0.905 ± 0.016, and AUC, 0.888; Extreme Gradient Boost Classifier accuracy, 0.903 ± 0.016, and AUC, 0.895; Gradient Boost Classifier accuracy, 0.898 ± 0.021, and AUC, 0.872). Simultaneously, we derived the importance ranking of the variable BAR among the included variables (in Light Gradient Boost Classifier, the BAR ranked fourth; in Extreme Gradient Boost Classifier, the BAR ranked sixth; in Gradient Boost Classifier, the BAR ranked fifth). To further evaluate the clinical utility of BAR, we divided patients into three groups based on their BAR values: Group 1 (BAR < 4.9 mg/g), Group 2 (BAR ≥ 4.9 and ≤10.5 mg/g), and Group 3 (BAR ≥ 10.5 mg/g). This stratification revealed significant differences in mortality across all time points: in-hospital mortality (7.61% vs. 15.16% vs. 31.63%), as well as one-month (8.51% vs. 17.46% vs. 36.39%), three-month (9.55% vs. 20.14% vs. 41.84%), and one-year mortality (11.57% vs. 23.76% vs. 46.60%). Building on this observation, we employed the Cox proportional hazards regression model to assess the impact of BAR segmentation on survival. Compared to Group 1, Groups 2 and 3 had significantly higher hazard ratios (95% confidence interval (CI)) for one-month mortality: 1.77 (1.37–2.30) and 3.17 (2.17–4.62), respectively. To further underscore the clinical potential of BAR as a standalone measure, we compared its performance to established clinical scores, like sequential organ failure assessment (SOFA), GCS, and acute physiology score III(APS-III), using receiver operator characteristic curve (ROC) analysis. Notably, the AUC values (95%CI) of the BAR were 0.67 (0.64–0.70), 0.68 (0.65–0.70), and 0.68 (0.65–0.70) for one-month mortality, three-month mortality, and one-year mortality. The AUC value of the SOFA did not significantly differ from that of the BAR. In conclusion, the BAR is a highly influential factor in predicting mortality in TBI patients and should be given careful consideration in future TBI prediction research. The blood urea nitrogen-to-albumin ratio may predict mortality in TBI patients. Full article

The rate of change in the relative amount of active and passive carbon (AC and PC) due to the land management practices (cropping systems combined with tillage) may vary with soil types depending on their level of chemical and/or physical protection from the decomposition but has rarely been directly measured. We have quantified the C storage potentiality of different soil types, namely old alluvial Inceptisol of Malda and recent alluvial Entisol of Coochbehar in West Bengal (subtropical eastern India) under the influence of different cropping systems (rice-maize: RM and rice-wheat: RW) and tillage practices (zero-tillage: ZT and conventional tillage: CT). The key objective was to demonstrate the short-term impact of conservation agriculture (CA) on soil C dynamics over the conventional practice. Research revealed that after short-term CA, total organic carbon (TOC), AC, PC, and total nitrogen (TN) showed significant (p < 0.05) improvement under the RM cropping system over the RW. The highest TOC content under the RM cropping system was recorded in the sites of Malda over the Coochbehar sites. The ZT significantly (p < 0.05) enhanced the TOC in the upper layers (0–5 and 5–10 cm) and the CT showed improvements in the lower depths (10–20 cm). We observed some irregular variations in the interactions of the cropping system and tillage with respect to different sites. However, the ZT performed better in improving C fractions under RM and RW as compared to CT. The TOC and TN stocks were maximum in the lower depth which was evident in both soil types. The TOC linearly regressed on TN accounted for 94.2% variability (R² = 0.942) of the C accumulation in soil and vice-versa. The PC was in a significant relationship with TN (R² = 0.943), but AC was moderately regressed (R² = 0.851). Lower stratification ratio values in Coochbehar soils (sandy loam in texture) indicated higher profile distribution of AC and PC in the soil profile; while in the Inceptisol, accumulation of the C fractions on the soil surface due to heavy texture resulted in the higher stratification values. The novelty of this study is that old alluvial Inceptisol showed a comparatively greater amount of AC and PC storage capability in comparison with the new alluvial Entisol. Conclusively, our study demonstrated that the adoption of conservation agriculture (CA practice/ZT) in cropping systems with higher C biomass input would significantly enhance the AC and PC fractions; however, the amount of storage is highly governed by the soil type and climatic factors. Full article

In this paper, a series of field surveys were carried out along the Nestos River watershed (NE Greece) to assess the influence of two hydropower dams (Thissavros and Platanovrisi) upon the hydrology, hydrochemistry and nutrients stoichiometry of the river. Results showed that Nestos hydrology, downstream of the reservoirs, is entirely governed by the man-induced hydropower-driven dam retention/release policy. Dams’ operation increased the retention of dissolved inorganic nitrogen (DIN) and total suspended solids (TSS) significantly, affecting their downstream fluxes, even under water release regime. On the contrary, dams’ construction and operation did not seem to influence the downstream fluxes of dissolved inorganic phosphorus (DIP) and silica (DSi), although these elements also depended on the releasing policy. DIN retention, combined with the dependence of DIP to the water level of Thissavros, resulted in alteration of the N:P ratio at the downstream part. Almost all nutrients were stored at the bottom layer of Thissavros reservoir, especially under the summer stratification regime. Platanovrisi reservoir acts as a buffer zone between Thissavros and the Nestos downstream part. Anoxic conditions in the reservoirs favour the transformation of nitrates into ammonia and the remineralization of phosphorus from sediments, creating a degraded environment for freshwater fauna. Full article

Background: The Glasgow-Blatchford Score (GBS) is one of the most widely used scoring systems for predicting clinical outcomes for gastrointestinal bleeding (GIB). However, the clinical significance of the GBS in predicting GIB in patients with heart failure (HF) remains unclear. Methods and Results: We conducted a prospective observational study in which we collected the clinical data of a total of 2236 patients (1130 men, median 70 years old) who were admitted to Fukushima Medical University Hospital for acute decompensated HF. During the post-discharge follow-up period of a median of 1235 days, seventy-eight (3.5%) patients experienced GIB. The GBS was calculated based on blood urea nitrogen, hemoglobin, systolic blood pressure, heart rate, and history of hepatic disease. The survival classification and regression tree analysis revealed that the accurate cut-off point of the GBS in predicting post-discharge GIB was six points. The patients were divided into two groups: the high GBS group (GBS > 6, n = 702, 31.4%) and the low GBS group (GBS ≤ 6, n = 1534, 68.6%). The Kaplan–Meier analysis showed that GIB rates were higher in the high GBS group than in the low GBS group. Multivariate Cox proportional hazards analysis adjusted for age, malignant tumor, and albumin indicated that a high GBS was an independent predictor of GIB (hazards ratio 2.258, 95% confidence interval 1.326–3.845, p = 0.003). Conclusions: A high GBS is an independent predictor and useful risk stratification score of post-discharge GIB in patients with HF. Full article

Between May and July 2018, Ireland experienced an exceptional heat wave, which broke long-term temperature and drought records. These calm, stable conditions were abruptly interrupted by a second extreme weather event, Atlantic Storm Hector, in late June. Using high-frequency monitoring data, coupled with fortnightly biological sampling, we show that the storm directly affected the stratification pattern of Lough Feeagh, resulting in an intense mixing event. The lake restabilised quickly after the storm as the heatwave continued. During the storm there was a three-fold reduction in Schmidt stability, with a mixed layer deepening of 9.5 m coinciding with a two-fold reduction in chlorophyll a but a three-fold increase in total zooplankton biomass. Epilimnetic respiration increased and net ecosystem productivity decreased. The ratio of total nitrogen:total phosphorus from in-lake versus inflow rivers was decoupled, leading to a cascade effect on higher trophic levels. A step change in nitrogen:phosphorus imbalances suggested that the zooplankton community shifted from phosphorus to nitrogen nutrient constraints. Such characterisations of both lake thermal and ecological responses to extreme weather events are relatively rare but are crucial to our understanding of how lakes are changing as the impacts of global climate change accelerate. Full article