Objectives: To investigate the correlation of cardiac magnetic resonance (CMR) feature-tracking with conventional CMR parameters in patients with a first anterior ST-segment elevation myocardial infarction (STEMI).Methods: This sub-analysis of OCTAMI (Optical Coherence Tomography Examination in Acute Myocardial Infarction) registry included 129 patients who finished a CMR examination 1 month after a first anterior STEMI. Cine images were applied to calculate both global and segmental left ventricular peak strain parameters. The patients were divided into two groups by left ventricular ejection fraction (LVEF) and compared with 42 healthy controls. Segmental late gadolinium enhancement (LGE) was graded according to LGE transmurality as follows: (1) >0 to ≤ 25%; (2) >25 to ≤ 50%; (3) >50 to ≤ 75%; (4) >75%. Left ventricle was divided into infarcted, adjacent, and remote regions to assess regional function.Results: Compared with controls, global radial (28.39 ± 5.08% vs. 38.54 ± 9.27%, p < 0.05), circumferential (−16.91 ± 2.11% vs. −20.77 ± 2.78%, p < 0.05), and longitudinal (−13.06 ± 2.15 vs. −15.52 ± 2.69, p < 0.05) strains were impaired in STEMI patients with normal LVEF (≥55%). Strain parameters were strongly associated with LGE (radial: r = 0.65; circumferential: r = 0.69; longitudinal: r = 0.61; all p < 0.05). A significant and stepwise impairment of global strains was observed in groups divided by LGE tertiles. Furthermore, segmental strain was different in various degrees of LGE transmurality especially for radial and circumferential strain. Strains of adjacent region were better than infarcted region in radial and circumferential directions and worse than remote region in all three directions.Conclusion: Global and regional strain could stratify different extent and transmurality of LGE, respectively. Although without LGE, adjacent region had impaired strains comparing with remote region.

No abstract

No abstract

No abstract

No abstract

ObjectiveElevated levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) are associated with heart failure-related death in hypertrophic cardiomyopathy (HCM), but the relationship between NT-proBNP level and sudden cardiac death (SCD) in HCM remains undefined.MethodsThe study prospectively enrolled 977 unrelated patients with HCM with available NT-proBNP results who were prospectively enrolled and followed for 3.0±2.1 years. The Harrell’s C-statistic under the receiver operating characteristic curve was calculated to evaluate discrimination performance. A combination model was constructed by adding NT-proBNP tertiles to the HCM Risk-SCD model. The correlation between log NT-proBNP level and cardiac fibrosis as measured by late gadolinium enhancement (LGE) or Masson’s staining was analysed.ResultsDuring follow-up, 29 patients had SCD. Increased log NT-proBNP levels were associated with an increased risk of SCD events (adjusted HR 22.27, 95% CI 10.93 to 65.63, p<0.001). The C-statistic of NT-proBNP in predicting SCD events was 0.80 (p<0.001). The combined model significantly improved the predictive efficiency of the HCM Risk-SCD model from 0.72 to 0.81 (p<0.05), with a relative integrated discrimination improvement of 0.002 (p<0.001) and net reclassification improvement of 0.67 (p<0.001). Furthermore, log NT-proBNP levels were significantly correlated with cardiac fibrosis as detected either by LGE (r=0.257, p<0.001) or by Masson’s trichrome staining in the myocardium (r=0.198, p<0.05).ConclusionNT-proBNP is an independent predictor of SCD in patients with HCM and may help with risk stratification of this disease.

Precipitation is projected to change intensity and seasonal regime under current global projections. However, little is known about how seasonal precipitation changes will affect soil respiration, especially in seasonally dry tropical forests. In a seasonally dry tropical forest in South China, we conducted a precipitation manipulation experiment to simulate a delayed wet season (DW) and a wetter wet season (WW) over a three-year period. In DW, we reduced 60% throughfall in April and May to delay the onset of the wet season and irrigated the same amount water into the plots in October and November to extend the end of the wet season. In WW, we irrigated 25% annual precipitation into plots in July and August. A control treatment (CT) receiving ambient precipitation was also established. Compared with CT, DW significantly increased soil moisture by 54% during October to November, and by 30% during December to April. The treatment of WW did not significantly affect monthly measured soil moisture. In 2015, DW significantly increased leaf area index and soil microbial biomass but decreased fine root biomass. In contrast, WW significantly decreased fine root biomass and forest floor litter stocks. Soil respiration was not affected by DW, which could be attributed to the increased microbial biomass offsetting the decrease in fine root biomass. In contrast, WW significantly increased soil respiration from 3.40 to 3.90 μmol m −2 s −1 in the third year, mainly due to the increased litter decomposition and soil pH (from 4.48 to 4.68). The present study suggests that both a delayed wet season and a wetter wet season will have significant impacts on soil respiration-associated ecosystem components. However, the ecosystem components can respond in different directions to the same change in precipitation, which ultimately affected soil respiration. K E Y W O R D S climate change, precipitation regime, rainfall change, soil CO 2 , tropics S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section. How to cite this article: Yu S, Mo Q, Chen Y, et al. Effects of seasonal precipitation change on soil respiration processes in a seasonally dry tropical forest. Ecol Evol. 2020;10:467-479.

Leaf soluble sugars and starch are important components of nonstructural carbohydrates (NSCs), which are crucial for plant growth, development, and reproduction. Although there is a large body of research focusing on the regulation of plant NSC (soluble sugars and starch) concentrations, the response of foliar NSC concentrations to continuous nitrogen (N) and phosphorus (P) addition is still unclear, especially in tropical forests. Here, we used a long‐term manipulative field experiment to investigate the response of leaf NSC concentrations to continuous N and P addition (3‐, 5‐, and 8‐year fertilization) in a tropical forest in southern China. We found significant species‐specific variation in leaf NSC concentrations in this tropical forest. Phosphorus addition dramatically decreased both leaf soluble sugar and starch concentrations, while N addition had no significant effects on leaf soluble sugar and starch concentrations. These results suggest that, in plants growing in P‐limiting tropical soil, leaf NSC concentrations are regulated by soil P availability rather than N availability. Moreover, the negative relationships between NSC concentrations and leaf mass per area (LMA) revealed that NSCs could supply excess carbon (C) for leaf expansion under P addition. This was further supported by the increased structural P fraction after P fertilization in our previous study at the same site. We conclude that soil P availability strongly regulates leaf starch and soluble sugar concentrations in the tropical tree species included in this study. The response of leaf NSC concentrations to long‐term N and P addition can reflect the close relationships between plant C dynamics and soil nutrient availability in tropical forests. Maintaining relatively higher leaf NSC concentrations in tropical plants can be a potential mechanism for adapting to P‐deficient conditions.