American oil palm from Brazil: genetic diversity, population structure, and core collection.

The American oil palm [Elaeis oleifera (Knuth) Cortés] has pronounced importance in oil palm breeding programs. Here, a germplasm bank (GB) of E. oleifera plants collected in the Amazon rainforest in Brazil was submitted to single nucleotide polymorphism (SNP) marker identification, selection, and use, aiming to characterize genetic diversity and population structure and to design a core collection (CC). Five hundred and fifty-three plants from 206 subsamples, collected at 19 localities spread throughout six geographic regions, were submitted to genotyping-by-sequencing analysis. A set of 1,827 high-quality SNP markers was then selected and used to run the genetic diversity and population structure analysis. The genetic diversity found is of moderate degree, and probably only a small portion of the species diversity is represented in the collection. The possible reason for that is the collecting strategy used, which collected subsamples only around the most prominent watercourses in the region. The average degree of genetic differentiation among subsamples is very high, indicating the presence of high interpopulation differentiation. The collection showed a low level of endogamy. The low average gene flow found indicates that genetic isolation caused by drift is occurring, and there is a need to review the conservation strategy. A set of 245 SNPs distributed throughout all 16 chromosomes was used to design CC based on maximizing the strategy of diversity. The optimal adjustment of the validated parameters, maintained while taking fewest subsamples, led to the choice of a model containing 20% of the entire collection as the ideal to form the CC

Early Empiric Antibiotic Use Is Associated With Delayed Feeding Tolerance in Preterm Infants: A Retrospective Analysis

The causative factors of neonatal feeding intolerance are poorly understood, but potentially related to clinical practices such as empiric antibiotic usage. The objective of this study was to evaluate whether early empiric antibiotic exposure negatively affects preterm infants' enteral feeding tolerance. Data from infants without risk factors for sepsis, 500 to 1499 g birth weight and 24 to 34 weeks gestational age were analyzed. The primary outcomes were the empiric antibiotic exposure effects on the infants' total parenteral nutrition usage duration and prevalence of necrotizing enterocolitis (NEC). Among the 901 infants included, 67 were exposed to early empiric antibiotic. A 50% increase in parenteral nutrition usage duration and a 4-fold greater prevalence of NEC was seen in the early empiric antibiotic-exposed neonates, when compared with control infants (P<0.01). Early empiric antibiotic exposure appears to negatively influence preterm infant feeding tolerance and possibly contributes to NEC.Brazilian Ministry of HealthUniv Sao Paulo, Fac Med Ribeirao Preto, Sao Paulo, BrazilUniv Sao Paulo, Fac Med Sau Paulo, Sao Paulo, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, BrazilInst Med Integral Prof Fernando Figueira IMIP, Recife, PE, BrazilUniv Fed Maranhao, Hosp Univ, Sao Luis, BrazilUniv Estadual Campinas, Fac Ciencias Med, Sao Paulo, BrazilUNESP, Fac Med Botucatu, Botucatu, SP, BrazilFiocruz MS, Inst Fernandes Figueira, Rio De Janeiro, BrazilPUC Porto Alegre, Fac Med, Porto Alegre, RS, BrazilUniv Fed Rio Grande do Sul, Porto Alegre, RS, BrazilUniv Estado Rio De Janeiro, Rio De Janeiro, BrazilUniv Fed Minas Gerais, Belo Horizonte, MG, BrazilUniv Fed Uberlandia, Uberlandia, MG, BrazilFac Ciencias Med Minas Gerais, Belo Horizonte, MG, BrazilUniv Sao Paulo, Hosp Univ, Sao Paulo, BrazilHosp Estadual Sumare, Sumare, BrazilHosp Geral Pirajussara, Taboao De Serra, BrazilHosp Estadual Diadema, Diadema, BrazilUniv Estadual Londrina, Londrina, BrazilUniv Fed Parana, Curitiba, Parana, BrazilUniv Toronto, Toronto, ON, CanadaUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, BrazilBrazilian Ministry of HealthWeb of Scienc

Sensitivity of South American tropical forests to an extreme climate anomaly

NERC Knowledge Exchange Fellowship (NE/V018760/1) to E.N.H.C.The tropical forest carbon sink is known to be drought sensitive, but it is unclear which forests are the most vulnerable to extreme events. Forests with hotter and drier baseline conditions may be protected by prior adaptation, or more vulnerable because they operate closer to physiological limits. Here we report that forests in drier South American climates experienced the greatest impacts of the 2015–2016 El Niño, indicating greater vulnerability to extreme temperatures and drought. The long-term, ground-measured tree-by-tree responses of 123 forest plots across tropical South America show that the biomass carbon sink ceased during the event with carbon balance becoming indistinguishable from zero (−0.02 ± 0.37 Mg C ha−1 per year). However, intact tropical South American forests overall were no more sensitive to the extreme 2015–2016 El Niño than to previous less intense events, remaining a key defence against climate change as long as they are protected.Publisher PDFPeer reviewe