Correction to: Life cycle assessment of electricity generation: a review of the characteristics of existing literature

The International Journal of Life Cycle Assessment - The original version of this article unfortunately contained a mistake which was missed during typesetting. The figures of Graph 1 and...     

High-Resolution Fractionation of Signaling Endosomes Containing Different Receptors

Receptor endocytosis is regulated by ligand binding, and receptors may signal after endocytosis in signaling endosomes. We hypothesized that signaling endosomes containing different types of receptors may be distinct from one another and have different physical characteristics. To test this hypothesis, we developed a high-resolution organelle fractionation method based on mass and density, optimized to resolve endosomes from other organelles. Three different types of receptors undergoing ligand-induced endocytosis were localized predominately in endosomes that were resolved from one another using this method. Endosomes containing activated receptor tyrosine kinases (RTKs), TrkA and EGFR, were similar to one another. Endosomes containing p75^NTR (in the tumor necrosis receptor superfamily) and PAC1 (a G-protein-coupled receptor) were distinct from each other and from RTK endosomes. Receptor-specific endosomes may direct the intracellular location and duration of signal transduction pathways to dictate response to signals and determine cell fate.     

A method for characterizing Cas9 variants via a one-million target sequence library of self-targeting sgRNAs

Detailed target-selectivity information and experiment-based efficacy prediction tools are primarily available for Streptococcus pyogenes Cas9 (SpCas9). One obstacle to develop such tools is the rarity of accurate data. Here, we report a method termed ‘Self-targeting sgRNA Library Screen’ (SLS) for assaying the activity of Cas9 nucleases in bacteria using random target/sgRNA libraries of self-targeting sgRNAs. Exploiting more than a million different sequences, we demonstrate the use of the method with the SpCas9-HF1 variant to analyse its activity and reveal motifs that influence its target-selectivity. We have also developed an algorithm for predicting the activity of SpCas9-HF1 with an accuracy matching those of existing tools. SLS is a facile alternative to the much more expensive and laborious approaches used currently and has the capability of delivering sufficient amount of data for most of the orthologs and variants of SpCas9.     

Evaluation of baits for trapping of Neotropical flower chafer beetles (Coleoptera: Scarabaeoidea: Cetoniinae)

The lack of a standardized protocol to efficiently capture flower chafer beetles (Coleoptera: Scarabaeoidea: Cetoniinae) in the wild limits studies regarding the ecology of the group, as well as systematic collections seeking species surveys for taxonomic studies, especially in the Neotropical region. We investigate the efficiency of different baits to capture flower chafer beetles in the Brazilian Cerrado: (i) banana; (ii) banana + sugarcane juice; (iii) pineapple; (iv) pineapple + sugarcane juice; (v) sugarcane juice; or (vi) water (control). From January to December 2014, we sampled these beetles using a typical aerial fruit‐baited trap, every 15 days in ten sites of Brazilian Cerrado, in Aquidauana, Mato Grosso do Sul, Brazil. Traps baited with banana + sugarcane juice, pineapple + sugarcane juice and sugarcane juice alone sampled the greatest species richness and abundance of flower chafer beetles when compared to the other baits used. Our results indicated the importance of sugarcane juice, either used in isolation or as a coadjutant in the fermentation process of the tested fruits for efficient sampling of flower chafer beetle biodiversity. Finally, studies that investigate the addition of other substances in the fermentation process of the fruits, as well as the attractiveness of other native or exotic fruits that are widely distributed in the Neotropical region, can advance our knowledge of sampling of these beetles.     

Establishment of the nuclear location of Dictyostelium discoideum plasmids

The nuclear location of the Dictyostelium discoideum plasmids was studied using a biochemical approach based on the presence of plasmid sequences in nucleosomes. This analysis revealed that all four of the known plasmids (Ddp1, Ddp2, Ddp3, Ddp5) are present in chromatin. This evidence establishes that the D. discoideum plasmids are not cytoplasmic but located in the nucleus. D. discoideum is unique among eukaryotes in possessing a group of nonhomologous endogenous plasmids in its nucleus. These plasmids are excellent starting material for construction of nuclear transformation and expression vectors. Such vectors upon transformation into D. discoideum are also present in chromatin as expected for DNA located in the nucleus.