scholarly journals Relationships between plant community productivity and diversity vary with trampling disturbance in an Inner-Mongolian steppe

Author(s):  
Yinzhan Liu ◽  
Luna Zhang ◽  
Yangyang Han ◽  
Anqun Chen ◽  
Renhui Miao ◽  
...  

Abstract The relationship between diversity and productivity of plant communities is an important issue in grassland restoration. However, the degree to which this relationship varies during the restoration stage after trampling disturbance is not clear. Here, we conducted a five-year study in a steppe after 4-year trampling to detect restoration patterns of plant community and investigate variation in diversity-productivity relationships. Our results showed that community cover, abundance, height, and productivity recovered quickly after the trampling disturbance ceased. However, the recovery of diversity was slower than biomass in the steppe. In addition, grass, annual, and biennial recovery was more rapidly than the recovery of forbs in the steppe. Moreover, following the restoration process, the positive correlation between productivity and diversity was decoupled, and a negative correlation between productivity and diversity developed. Our finding provides the key evidence for the asynchronous relation between productivity and diversity, and reveals that grass restored more rapidly than forbs in plant community restoration after disturbance. This study indicates that the trade-off between plant community structure and function can vary with the restoration process, and implicates that future modeling and experimental studies should focus on the different responses of productivity and diversity in plant community restoration.

Author(s):  
Gianmarco Secco ◽  
◽  
Marzia Delorenzo ◽  
Francesco Salinaro ◽  
Caterina Zattera ◽  
...  

AbstractBedside lung ultrasound (LUS) can play a role in the setting of the SarsCoV2 pneumonia pandemic. To evaluate the clinical and LUS features of COVID-19 in the ED and their potential prognostic role, a cohort of laboratory-confirmed COVID-19 patients underwent LUS upon admission in the ED. LUS score was derived from 12 fields. A prevalent LUS pattern was assigned depending on the presence of interstitial syndrome only (Interstitial Pattern), or evidence of subpleural consolidations in at least two fields (Consolidation Pattern). The endpoint was 30-day mortality. The relationship between hemogasanalysis parameters and LUS score was also evaluated. Out of 312 patients, only 36 (11.5%) did not present lung involvment, as defined by LUS score < 1. The majority of patients were admitted either in a general ward (53.8%) or in intensive care unit (9.6%), whereas 106 patients (33.9%) were discharged from the ED. In-hospital mortality was 25.3%, and 30-day survival was 67.6%. A LUS score > 13 had a 77.2% sensitivity and a 71.5% specificity (AUC 0.814; p < 0.001) in predicting mortality. LUS alterations were more frequent (64%) in the posterior lower fields. LUS score was related with P/F (R2 0.68; p < 0.0001) and P/F at FiO2 = 21% (R2 0.59; p < 0.0001). The correlation between LUS score and P/F was not influenced by the prevalent ultrasound pattern. LUS represents an effective tool in both defining diagnosis and stratifying prognosis of COVID-19 pneumonia. The correlation between LUS and hemogasanalysis parameters underscores its role in evaluating lung structure and function.


2018 ◽  
Vol 66 ◽  
pp. S260
Author(s):  
A.R. Carter ◽  
D.L. Santos Ferreira ◽  
A. Taylor ◽  
N. Chaturvedi ◽  
A.D. Hughes ◽  
...  

Author(s):  
Lorenza González-Mariscal ◽  
Antonia Avila ◽  
Abigail Betanzos

Open Heart ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. e000831 ◽  
Author(s):  
Melissa Suzanne Burroughs Peña ◽  
Katrina Swett ◽  
Robert C Kaplan ◽  
Krista Perreira ◽  
Martha Daviglus ◽  
...  

ObjectiveTo describe the relationship of household secondhand smoke (SHS) exposure and cardiac structure and function.MethodsParticipants (n=1069; 68 % female; age 45–74 years) without history of tobacco use, coronary artery disease or severe valvular disease were included. Past childhood (starting at age <13 years), adolescent/adult and current exposure to household SHS was assessed. Survey linear regression analyses were used to model the relationship of SHS exposure and echocardiographic measures of cardiac structure and function, adjusting for covariates (age, sex, study site, alcohol use, physical activity and education).ResultsSHS exposure in childhood only was associated with reduced E/A velocity ratio (β=−0.06 (SE 0.02), p=0.008). SHS exposure in adolescence/adult only was associated with increased left ventricular ejection fraction (LVEF) (1.2 (0.6), p=0.04), left atrial volume index (1.7 (0.8), p=0.04) and decreased isovolumic relaxation time (−0.003 (0.002), p=0.03). SHS exposure in childhood and adolescence/adult was associated with worse left ventricular global longitudinal strain (LVGLS) (two-chamber) (0.8 (0.4), p= 0.049). Compared with individuals who do not live with a tobacco smoker, individuals who currently live with at least one tobacco smoker had reduced LVEF (−1.4 (0.6), p=0.02), LVGLS (average) (0.9 (0.40), p=0.03), medial E′ velocity (−0.5 (0.2), p=0.01), E/A ratio (−0.09 (0.03), p=0.003) and right ventricular fractional area change (−0.02 (0.01), p=0.01) with increased isovolumic relaxation time (0.006 (0.003), p=0.04).ConclusionsPast and current household exposure to SHS was associated with abnormalities in cardiac systolic and diastolic function. Reducing household SHS exposure may be an opportunity for cardiac dysfunction prevention to reduce the risk of future clinical heart failure.


Author(s):  
Mark Lorch

This chapter examines proteins, the dominant proportion of cellular machinery, and the relationship between protein structure and function. The multitude of biological processes needed to keep cells functioning are managed in the organism or cell by a massive cohort of proteins, together known as the proteome. The twenty amino acids that make up the bulk of proteins produce the vast array of protein structures. However, amino acids alone do not provide quite enough chemical variety to complete all of the biochemical activity of a cell, so the chapter also explores post-translation modifications. It finishes by looking as some dynamic aspects of proteins, including enzyme kinetics and the protein folding problem.


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