Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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Screening chloroplast regions in Calophyllum brasiliense (Calophyllaceae) for suitability for population genetic analyses

The uniparental inheritance and conserved structure of the chloroplast genome among many angiosperms makes it suitable for constructing gene lineages and inferring population histories based on these relationships. However, the analysis of a single chloroplast region to solve population issues has not yielded the desired amount of variability due to the low mutation rate. Therefore, it is necessary to screen and carefully analyze chloroplast intergenic or intronic regions to select the most appropriate for studying the genetic variability in the chloroplast genome of a particular taxon. In this context, the aim of this work was to characterize 8 regions in Calophyllum brasiliense using 11 selected primer pairs and to evaluate their usefulness for phylogeographic analysis. Intergenic spacers petA-psbJ, petG-trnP and rpl32-trnL and the trnL intron demonstrated potentially informative sites. The combination of these 4 regions will allow the analysis of genetic population structure and the integration of historical aspects to inform strategies for conserving C. brasiliense, especially for highly impacted populations and those at risk of local extinction.Laboratorio de Sistemática y Biología Evolutiv

RcgA and RcgR, Two Novel Proteins Involved in the Conjugative Transfer of Rhizobial Plasmids

Castellani LG, Luchetti A, Nilsson JF, et al. RcgA and RcgR, Two Novel Proteins Involved in the Conjugative Transfer of Rhizobial Plasmids. mBio. 2022.Rhizobia are Gram-negative bacteria that are able to establish a nitrogen-fixing symbiotic interaction with leguminous plants. Rhizobia genomes usually harbor several plasmids which can be transferred to other organisms by conjugation. Two main mechanisms of the regulation of rhizobial plasmid transfer have been described: quorum sensing (QS) and the rctA/rctB system. Nevertheless, new genes and molecules that modulate conjugative transfer have recently been described, demonstrating that new actors can tightly regulate the process. In this work, by means of bioinformatics tools and molecular biology approaches, two hypothetical genes are identified as playing key roles in conjugative transfer. These genes are located between conjugative genes of plasmid pRfaLPU83a from Rhizobium favelukesii LPU83, a plasmid that shows a conjugative transfer behavior depending on the genomic background. One of the two mentioned genes, rcgA, is essential for conjugation, while the other, rcgR, acts as an inhibitor of the process. In addition to introducing this new regulatory system, we show evidence of the functions of these genes in different genomic backgrounds and confirm that homologous proteins from non-closely related organisms have the same functions. These findings set up the basis for a new regulatory circuit of the conjugative transfer of plasmids. IMPORTANCE: Extrachromosomal DNA elements, such as plasmids, allow for the adaptation of bacteria to new environments by conferring new determinants. Via conjugation, plasmids can be transferred between members of the same bacterial species, different species, or even to organisms belonging to a different kingdom. Knowledge about the regulatory systems of plasmid conjugative transfer is key in understanding the dynamics of their dissemination in the environment. As the increasing availability of genomes raises the number of predicted proteins with unknown functions, deeper experimental procedures help to elucidate the roles of these determinants. In this work, two uncharacterized proteins that constitute a new regulatory circuit with a key role in the conjugative transfer of rhizobial plasmids were discovered

Graves' disease TSHR-stimulating antibodies (TSAbs) induce the activation of immature thymocytes: a clue to the riddle of TSAbs generation?

Graves' disease (GD) is an autoimmune thyroid disease defined by the production of stimulating autoantibodies to the thyroid-stimulating hormone receptor (TSHR) (TSAbs) that induce a sustained state of hyperthyroidism in patients. We previously demonstrated that TSHR, the target of this autoimmune response, is also a key susceptibility gene for GD, probably acting through thymic-dependent central tolerance. We also showed that TSHR is, unexpectedly, expressed in thymocytes. In this report, we confirm the expression of TSHR in thymocytes by protein immunoblotting and quantitative PCR, and show that expression is confined to maturing thymocytes. Using functional assays, we show that thymic TSHR is functional and that TSAbs can stimulate thymocytes through this receptor. This new activity of TSAbs on thymocytes may: 1) explain GD-associated thymic enlargement (hyperplasia), and 2) suggest the provocative hypothesis that the continuous stimulation of thymocytes by TSAbs could lead to a vicious cycle of iterative improvement of the affinity and stimulating capability of initially low-affinity antibacterial (e.g., Yersinia) Abs cross-reactive with TSHR, eventually leading to TSAbs. This may help to fill one of the gaps in our present understanding of unusual characteristics of TSAbs

Exopolysaccharide Characterization of Rhizobium favelukesii LPU83 and Its Role in the Symbiosis With Alfalfa

Castellani LG, Luchetti A, Nilsson JF, et al. Exopolysaccharide Characterization of Rhizobium favelukesii LPU83 and Its Role in the Symbiosis With Alfalfa. Frontiers in Plant Science. 2021;12: 642576.One of the greatest inputs of available nitrogen into the biosphere occurs through the biological N2-fixation to ammonium as result of the symbiosis between rhizobia and leguminous plants. These interactions allow increased crop yields on nitrogen-poor soils. Exopolysaccharides (EPS) are key components for the establishment of an effective symbiosis between alfalfa and Ensifer meliloti, as bacteria that lack EPS are unable to infect the host plants. Rhizobium favelukesii LPU83 is an acid-tolerant rhizobia strain capable of nodulating alfalfa but inefficient to fix nitrogen. Aiming to identify the molecular determinants that allow R. favelukesii to infect plants, we studied its EPS biosynthesis. LPU83 produces an EPS I identical to the one present in E. meliloti, but the organization of the genes involved in its synthesis is different. The main gene cluster needed for the synthesis of EPS I in E. meliloti, is split into three different sections in R. favelukesii, which probably arose by a recent event of horizontal gene transfer. A R. favelukesii strain devoided of all the genes needed for the synthesis of EPS I is still able to infect and nodulate alfalfa, suggesting that attention should be directed to other molecules involved in the development of the symbiosis

On the positive fundamental value of money with short-sale constraints

Money, Short-sale constraints, Fundamental value, Asset pricing bubbles, (Technically) incomplete financial markets, Financial recognizability and insurance services, D52, E41, G12,