Analysis of 16S rRNA and mxaF genes revealing insights into Methylobacterium niche-specific plant association

The genus Methylobacterium comprises pink-pigmented facultative methylotrophic (PPFM) bacteria, known to be an important plant-associated bacterial group. Species of this group, described as plant-nodulating, have the dual capacity of producing cytokinin and enzymes, such as pectinase and cellulase, involved in systemic resistance induction and nitrogen fixation under specific plant environmental conditions. The aim hereby was to evaluate the phylogenetic distribution of Methylobacterium spp. isolates from different host plants. Thus, a comparative analysis between sequences from structural (16S rRNA) and functional mxaF (which codifies for a subunit of the enzyme methanol dehydrogenase) ubiquitous genes, was undertaken. Notably, some Methylobacterium spp. isolates are generalists through colonizing more than one host plant, whereas others are exclusively found in certain specific plant-species. Congruency between phylogeny and specific host inhabitance was higher in the mxaF gene than in the 16S rRNA, a possible indication of function-based selection in this niche. Therefore, in a first stage, plant colonization by Methylobacterium spp. could represent generalist behavior, possibly related to microbial competition and adaptation to a plant environment. Otherwise, niche-specific colonization is apparently impelled by the host plant

Important issues for feminist nutrition research – a case study from the savanna of West Africa

SUMMARY Nutrition education usually aims to change the practices of individual mothers. It may divert attention from real problems, increase anxiety or be dangerously inappropriate. This article argues that nutritionists should work at the community, policy and planning levels to create an environment where good nutrition becomes possible. The author describes her experiences with nutrition education, intersectoral cooperation, and nutritional monitoring. She summarises crucial issues for nutritional research and stresses the importance of learning from the mothers and taking their expressed needs as the major research orientation. RESUMEN Problemas importantes para la investigación de la nutrición feminista. Un estudio de caso en la sabana de Africa Occidental En general, la educación en nutrición intenta cambiar las prácticas de las madres a nivel individual. No obstante, puede distraeer la atencion de los problemas reales, incrementar la ansiedad en incluso resultar peligrosamente inadecuada. Este articulo argumenta que los nutricionistas deberian trabajar en los niveles de comunidad, planificación y politica para crear un ambiente en que la buena nutrición sea factible. La autora describe sus experiencias en educación nutricional, cooperación intersectorial y control de nutrición, resumen problemas cruciales para la investigación en esta área y enfatiza la importancia que tiene el aprender de las madres y adoptar sus necesidades explicitas como la orientación principal en la investigación. RESUMES L'importance de la recherche sur la nutrítion fémìnine: une étude de cas particulier dans la Savane d'Afrique de l'Quest L'enseignement de la nutrition a généralernent pour but de changer les habitudes de chaque mére. Il peut détourner l'attention des vrais problèmes augmenter l'anxiété ou être dangereusement inadéquat. Cet article soutient le fait que les hygiénistes alimentaires devraient tiavailler au niveau de la communauté, de la politique et de la planification afin de créer un environnement favorable a la bonne nutrition. L'auteur décrit ses experiences en ce qui concerne l'enseignement de la nutrition. la coopération íntersectorielle et la contrôle nutritionnel. Elle rèsume les points cruciaux pour les chercheurs en nutrition et souligne l'importance d'apprendre a partir des mères et de prendre leurs besoins comme ligne de conduite principale de la recherche

Identifying new isatin derivatives with GSK-3 inhibition capacity through molecular docking and bioassays

The semi-synthesis of 11 isatin derivatives was achieved through bimolecular nucleophilic substitution and click chemistry. Seven new compounds were obtained. All chemical structures were determined by infrared spectroscopy (IR), nuclear magnetic resonance spectrometry (NMR) and high-resolution mass spectrometry (HRMS) data. These derivatives were evaluated for their anti-GSK-3 activity and all isatin derivatives (N-alkyl and 1,2,3-triazolic) exhibited strong inhibitory activity, with 2b and 4h exhibiting remarkable potency. In addition, docking studies were performed with 2b and 2e models to unravel the molecular mechanism underlying the polar interactions on the GSK-3 ATP-binding site.This study was funded by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brasil (CAPES), Finance Code 001, by the National Council of Scientific and Technological Development (CNPq) and Foundation of Support to Research and Innovation of Espírito Santo (FAPES PPE-Agro No. 76418880/16). We also would like to acknowledge INCTBioNat (CNPq 465637/2014-0) for additional support and NCQP-UFES, as well as the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020, Programa Operacional Regional do Norte. L. R. R. also acknowledges her sabbatical leave fellowship (SFRH/BSAB/142991/2018) funded by FCT. D. F. is recipient of a doctoral fellowship (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020, Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

GREAT3 results I: systematic errors in shear estimation and the impact of real galaxy morphology

We present first results from the third GRavitational lEnsing Accuracy Testing (GREAT3) challenge, the third in a sequence of challenges for testing methods of inferring weak gravitational lensing shear distortions from simulated galaxy images. GREAT3 was divided into experiments to test three specific questions, and included simulated space- and ground-based data with constant or cosmologically-varying shear fields. The simplest (control) experiment included parametric galaxies with a realistic distribution of signal-to-noise, size, and ellipticity, and a complex point spread function (PSF). The other experiments tested the additional impact of realistic galaxy morphology, multiple exposure imaging, and the uncertainty about a spatially-varying PSF; the last two questions will be explored in Paper II. The 24 participating teams competed to estimate lensing shears to within systematic error tolerances for upcoming Stage-IV dark energy surveys, making 1525 submissions overall. GREAT3 saw considerable variety and innovation in the types of methods applied. Several teams now meet or exceed the targets in many of the tests conducted (to within the statistical errors). We conclude that the presence of realistic galaxy morphology in simulations changes shear calibration biases by $\sim 1$ per cent for a wide range of methods. Other effects such as truncation biases due to finite galaxy postage stamps, and the impact of galaxy type as measured by the S\'{e}rsic index, are quantified for the first time. Our results generalize previous studies regarding sensitivities to galaxy size and signal-to-noise, and to PSF properties such as seeing and defocus. Almost all methods' results support the simple model in which additive shear biases depend linearly on PSF ellipticity.Comment: 32 pages + 15 pages of technical appendices; 28 figures; submitted to MNRAS; latest version has minor updates in presentation of 4 figures, no changes in content or conclusion

In vitro Antiplasmodial Activities of Alkaloids Isolated from Roots of Worsleya procera (Lem.) Traub (Amaryllidaceae)

A combined phytochemical, crystallographic and biological study of Worsleya procera roots was performed. Fifteen alkaloids were identified by gas chromatography mass spectrometry (GC-MS) and seven of them were isolated. The structures of the alkaloids were elucidated by spectroscopic methods, and a detailed crystallographic study of tazettine was carried out. The isolated alkaloids and the obtained extracts were tested in vitro against Plasmodium falciparum (3D7 and K1 strains) and human hepatocarcinoma cells (HepG2) to assess their antiplasmodial and cytotoxic effects, respectively. One of the isolated alkaloid derivatives, lycorine, exhibited antiplasmodial activity against both sensitive (3D7) and resistant (K1) parasite strains in the low micromolar range (half-maximal sample inhibitory concentration (IC50) values of 2.5 and 3.1 µM, respectively) and displayed a low cytotoxicity profile, with a selectivity index greater than 100. Our findings indicate that lycorine is a hit for antimalarial drug discovery. Keywords: isoquinolinic alkaloids; Amaryllidaceae; Plasmodium falciparum; lycorine; tazettin

Analysis of 16S rRNA and mxaF genes reveling insights into Methylobacterium niche-specific plant association

The genus Methylobacterium comprises pink-pigmented facultative methylotrophic (PPFM) bacteria, known to be an important plant-associated bacterial group. Species of this group, described as plant-nodulating, have the dual capacity of producing cytokinin and enzymes, such as pectinase and cellulase, involved in systemic resistance induction and nitrogen fixation under specific plant environmental conditions. The aim hereby was to evaluate the phylogenetic distribution of Methylobacterium spp. isolates from different host plants. Thus, a comparative analysis between sequences from structural (16S rRNA) and functional mxaF (which codifies for a subunit of the enzyme methanol dehydrogenase) ubiquitous genes, was undertaken. Notably, some Methylobacterium spp. isolates are generalists through colonizing more than one host plant, whereas others are exclusively found in certain specific plant-species. Congruency between phylogeny and specific host inhabitance was higher in the mxaF gene than in the 16S rRNA, a possible indication of function-based selection in this niche. Therefore, in a first stage, plant colonization by Methylobacterium spp. could represent generalist behavior, possibly related to microbial competition and adaptation to a plant environment. Otherwise, niche-specific colonization is apparently impelled by the host plant

The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 Msun stellar mass limit

Spectroscopic analyses of H-rich WN5-6 stars within the young star clusters NGC 3603 and R136 are presented, using archival HST & VLT spectroscopy, & high spatial resolution near-IR photometry. We derive high T* for the WN stars in NGC 3603 (T*~42+/-2 kK) & R136 (T*~53+/-3 kK) plus clumping-corrected dM/dt ~ 2-5x10^-5 Msun/yr which closely agree with theoretical predictions. These stars make a disproportionate contribution to the global budget of their host clusters. R136a1 alone supplies ~7% of N(LyC) of the entire 30 Dor region. Comparisons with stellar models calculated for the main-sequence evolution of 85-500 Msun suggest ages of ~1.5 Myr & M_init in the range 105 - 170 Msun for 3 systems in NGC 3603, plus 165-320 Msun for 4 stars in R136. Our high stellar masses are supported by dynamical mass determinations for the components of NGC 3603 A1. We consider the predicted L_X of the R136 stars if they were close, colliding wind binaries. R136c is consistent with a colliding wind binary system. However, short period, colliding wind systems are excluded for R136a WN stars if mass ratios are of order unity. Widely separated systems would have been expected to harden owing to early dynamical encounters with other massive stars in such a dense environment. From simulated star clusters, whose constituents are randomly sampled from the Kroupa IMF, both clusters are consistent with a tentative upper mass limit of ~300 Msun. The Arches cluster is either too old, exhibits a deficiency of very massive stars, or more likely stellar masses have been underestimated - M_init for the most luminous stars in the Arches cluster approach 200 Msun according to contemporary stellar & photometric results. The potential for stars greatly exceeding 150 Msun within metal-poor galaxies suggests that such pair-instability SNe could occur within the local universe, as has been claimed for SN 2007bi (abridged).Comment: 20 pages, 14 figures, accepted for MNRAS. Version with higher resolution figures is available from http://pacrowther.staff.shef.ac.uk/R136.pdf See also http://www.eso.org/public/news/eso1030/ from Wed 21 from noon (CEST

Genome Sequence of Streptomyces sp. Strain RTd22, an Endophyte of the Mexican Sunflower

We report here the complete genome sequence of Streptomyces sp. strain RTd22, an endophytic actinobacterium that was isolated from the roots of the Mexican sunflower Tithonia diversifolia. The bacterium’s 11.1-Mb linear chromosome is predicted to encode a large number of unknown natural products

Avaliação do índice de estresse percebido dos alunos do curso de medicina, durante os diferentes ciclos de estágio do internato / Evaluation of the perceived stress index of medical students during the different internship cycles

Introdução: A resposta de estresse pode ser definida como uma experiência de desconforto emocional, acompanhada por mudanças bioquímicas, fisiológicas e comportamentais. As alterações fisiológicas desencadeadas pelo estresse no organismo humano podem proporcionar distúrbios psicológicos e cognitivos no indivíduo, o que afeta diretamente sua qualidade de vida e, no caso dos estudantes, o aprendizado. Dessa forma, o estresse crônico é uma condição que representa uma barreira para o bem-estar e educação do estudante de Medicina, principalmente durante os ciclos de estágios realizados no internato. Objetivo: Avaliar o índice de estresse percebido dos alunos do quinto e sexto ano do curso de Medicina, em cada um dos ciclos de estágio do internato. Materiais e Métodos: O estudo é descritivo transversal com abordagem quantitativa. A Escala de Percepção de Estresse - 10 (EPS-10) foi o instrumento utilizado para coleta de dados, e foi aplicada durante os diferentes ciclos de estágio durante o segundo semestre de 2020 e o primeiro semestre de 2021. Resultados: Obteve-se maior percepção de estresse por parte dos alunos no ciclo de Pediatria, quando comparado com os ciclos de Saúde Coletiva e Multidisciplinar. O mesmo ocorreu com o ciclo de Ginecologia e Obstetrícia, quando comparado com os mesmos dois ciclos. Conclusão: Nossos resultados sugerem diferenças no estresse percebido dos alunos durante os diferentes ciclos de estágio, apesar destas diferenças não terem sido identificadas para todas as áreas

Defensive interactions in soccer small-sided games: an integrated approach between the fundamental tactical principles and the social network analysis

This study aimed to 1) present a new analysis of the interactions between the tactical principles of defensive coverage and delay using the Social Network Analysis (SNA); 2) compare the defensive cooperation patterns presented by players of different categories during a 3vs.3 soccer small-sided games SSG; 3) compare the level of defensive prominence presented by defenders, midfielders, and forwards in 3vs.3 SSG within and between different categories. Twenty-eight soccer athletes from U-13 (n=14) and U-14 (n=14) categories of a sports club performed 3vs.3 SSG for the analysis of the defensive tactical principles. Defensive interactions were considered successful defensive coverage and a delay actions performed within the same time interval. Macro (density and clustering coefficient) and micro (degree centrality, degree prestige and page rank) analyses were used as SNA measures. Results indicated no significant differences between categories for the macro and micro analyses. Only in the U-14 category, midfielders presented higher prominence levels than the other playing positions (p=0.004). We concluded that U-13 and U-14 athletes are not different regarding defensive cooperation patterns. A higher positional tactical knowledge obtained through deliberate practice is essential to induce different defensive interactions between playing positions, as shown by significant differences only in the U-14 category