Amazon tree dominance across forest strata

The forests of Amazonia are among the most biodiverse plant communities on Earth. Given the immediate threats posed by climate and land-use change, an improved understanding of how this extraordinary biodiversity is spatially organized is urgently required to develop effective conservation strategies. Most Amazonian tree species are extremely rare but a few are common across the region. Indeed, just 227 ‘hyperdominant’ species account for >50% of all individuals >10 cm diameter at 1.3 m in height. Yet, the degree to which the phenomenon of hyperdominance is sensitive to tree size, the extent to which the composition of dominant species changes with size class and how evolutionary history constrains tree hyperdominance, all remain unknown. Here, we use a large floristic dataset to show that, while hyperdominance is a universal phenomenon across forest strata, different species dominate the forest understory, midstory and canopy. We further find that, although species belonging to a range of phylogenetically dispersed lineages have become hyperdominant in small size classes, hyperdominants in large size classes are restricted to a few lineages. Our results demonstrate that it is essential to consider all forest strata to understand regional patterns of dominance and composition in Amazonia. More generally, through the lens of 654 hyperdominant species, we outline a tractable pathway for understanding the functioning of half of Amazonian forests across vertical strata and geographical locations

Estimating the xenobiotics mixtures toxicity on aquatic organisms: the use of alpha-level of the fuzzy number.

Abstract: Agricultural practices that use various xenobiotics can contaminate surface water and groundwater with xenobiotics mixtures concentrations which cause serious risks to water quality and to the health of aquatic organisms that inhabit them. Xenobiotics in water when present as mixtures can exacerbate or reduce the toxic effects in aquatic organisms, when compared to the toxic effects of each individual component concentrations of the xenobiotics mixture. The objective of this study is to develop a mathematical method using ?-level of the fuzzy numbers with less accounts and simpler calculations to sort ecotoxicological effects in aquatic organisms of xenobiotics mixtures concentrations occurring in water, classifying them into antagonistic, additive or synergistic and also establishing the magnitude of the effects of concentrations of mixtures. The proposed method in this paper using fuzzy numbers can be suggested in protocols established by regulatory agencies to classify ecotoxicological effects of xenobiotics mixtures in water

Hypertension and renin-angiotensin system blockers are not associated with expression of angiotensin-converting enzyme 2 (ACE2) in the kidney

AIMS: Angiotensin-converting enzyme 2 (ACE2) is the cellular entry point for severe acute respiratory syndrome coronavirus (SARS-CoV-2)-the cause of coronavirus disease 2019 (COVID-19). However, the effect of renin-angiotensin system (RAS)-inhibition on ACE2 expression in human tissues of key relevance to blood pressure regulation and COVID-19 infection has not previously been reported. METHODS AND RESULTS: We examined how hypertension, its major metabolic co-phenotypes, and antihypertensive medications relate to ACE2 renal expression using information from up to 436 patients whose kidney transcriptomes were characterized by RNA-sequencing. We further validated some of the key observations in other human tissues and/or a controlled experimental model. Our data reveal increasing expression of ACE2 with age in both human lungs and the kidney. We show no association between renal expression of ACE2 and either hypertension or common types of RAS inhibiting drugs. We demonstrate that renal abundance of ACE2 is positively associated with a biochemical index of kidney function and show a strong enrichment for genes responsible for kidney health and disease in ACE2 co-expression analysis. CONCLUSION: Our results indicate that neither hypertension nor antihypertensive treatment is likely to alter the expression of the key entry receptor for SARS-CoV-2 in the human kidney. Our data further suggest that in the absence of SARS-CoV-2 infection, kidney ACE2 is most likely nephro-protective but the age-related increase in its expression within lungs and kidneys may be relevant to the risk of SARS-CoV-2 infection

Development of genomic SSR markers and molecular characterization of Magnaporthe oryzae isolates from wheat in Brazil.

Magnaporthe oryzae, the causal agent of wheat blast, was characterized on a molecular level with 38 newly isolated genomic SSR loci. Among the 31 wheat isolates analyzed, 15 polymorphic loci were detected, with an average of 1.7 alleles per locus, 28.9% of them being highly or reasonably informative. The number of polymorphic loci was higher in isolates from Londrina in the Brazilian state of Parana´ and Coromandel in Minas Gerais compared with Goiânia in Goiás and São Borja in Rio Grande do Sul. The rice isolate was clearly different from the wheat isolates, and the size difference in polymorphic SSR loci between one isolate from wheat and one isolate from rice was associated with the number of repeats. Some isolates collected from different states and in different years demonstrated similarities of 100%. The markers developed here are useful for the genetic analysis of M. oryzae isolated from wheat, and isolates representing the variability detected in the field can be used to search for better wheat blast resistance.2014Genetic variability Magnaporthe oryzae Microsatellite Wheat blas