Are your students safe to learn? The role of lecturer’s authentic leadership in the creation of psychologically safe environments and their impact on academic performance:The role of teacher's authentic leadership on the creation of psychologically safe environments and their impact on academic performance

As the role of students and lecturers in higher education changes, several questions emerge about the role of each of them on students? academic performance. This includes questions regarding the impact of the relationships between students, lecturer?s characteristics and the social environment on students? performance. To address these questions, this article reports a study of the impact of lecturer authentic leadership, psychological safety and network density on academic performance. It explores the relationship between network density, psychological safety and lecturer authentic leadership. A questionnaire was distributed to undergraduate students. A positive impact of lecturer authentic leadership and psychological safety on academic performance was found. Students from high-density groups tended to show better academic performance, higher psychological safety and tended to see their lecturers as being more authentic. A reflection on the role of the lecturer in higher education settings is presented. It also presents some recommendations on how student academic performance can be improved by the adoption of specific behaviours by their lecturer

Cellulose acetate in wound dressings formulations: potentialities and electrospinning capability

Série: IFMBE Proceedings, vol. 76Any open wound is a potential site for microorganisms’ invasion since their presence around us is inevitable. Skin wound healing relies on a series of complex physiochemical processes that remain a big challenge for healthcare professionals, particularly when the wounds are colonized by bacteria. Wound dressings play a major role in wound healing as they manage the wounded site, controlling the moisture balance and protecting the wound from repeated trauma, and by preventing possible infections from developing into more serious complications. Recently, bioactive dressings loaded with drugs and/or antimicrobial agents, allowing for a continuous and sustainable release of these molecules at the wounded site, have appeared in the market. Antimicrobial resistance is a growing health care problem, requiring more effective solutions than antibiotics. As such, nano- and microfibrous mats produced via electrospinning technique and loaded with natural-origin antimicrobial agents have attracted a lot of attention. Various polymers have been applied to engineer nanofibrous electrospun dressings. However, the environment impact of the synthesis and processing methods of synthetic polymers is undesirable. Therefore, the application of cellulose-derived materials (highly abundant polymer of natural-origin) becomes crucial as a green alternative to produce electrospun wound dressings with superior wettability, breathability and high capacity to promote cell proliferation, at relatively low costs. In this paper, different biomolecules loaded onto cellulose acetate (CA)-based polymeric nanofibers were investigated, and their antimicrobial properties were highlighted as alternatives to conventional antibiotics.Authors acknowledge the Portuguese Foundation for Science and Technology (FCT), FEDER funds by means of Competitive Factors Operational Program (POCI) for funding the projects POCI-01-0145-FEDER-028074 and UID/CTM/00264/2019

Endothelin receptor B antagonists decrease glioma cell viability independently of their cognate receptor

Background: Endothelin receptor antagonists inhibit the progression of many cancers, but research into their influence on glioma has been limited. Methods: We treated glioma cell lines, LN-229 and SW1088, and melanoma cell lines, A375 and WM35, with two endothelin receptor type B (ETRB)-specific antagonists, A-192621 and BQ788, and quantified viable cells by the capacity of their intracellular esterases to convert non-fluorescent calcein AM into green-fluorescent calcein. We assessed cell proliferation by labeling cells with carboxyfluorescein diacetate succinimidyl ester and quantifying the fluorescence by FACS analysis. We also examined the cell cycle status using BrdU/propidium iodide double staining and FACS analysis. We evaluated changes in gene expression by microarray analysis following treatment with A-192621 in glioma cells. We examined the role of ETRB by reducing its expression level using small interfering RNA (siRNA). Results: We report that two ETRB-specific antagonists, A-192621 and BQ788, reduce the number of viable cells in two glioma cell lines in a dose- and time-dependent manner. We describe similar results for two melanoma cell lines. The more potent of the two antagonists, A-192621, decreases the mean number of cell divisions at least in part by inducing a G2/M arrest and apoptosis. Microarray analysis of the effects of A-192621 treatment reveals up-regulation of several DNA damage-inducible genes. These results were confirmed by real-time RT-PCR. Importantly, reducing expression of ETRB with siRNAs does not abrogate the effects of either A-192621 or BQ788 in glioma or melanoma cells. Furthermore, BQ123, an endothelin receptor type A (ETRA)-specific antagonist, has no effect on cell viability in any of these cell lines, indicating that the ETRB-independent effects on cell viability exhibited by A-192621 and BQ788 are not a result of ETRA inhibition. Conclusion: While ETRB antagonists reduce the viability of glioma cells in vitro, it appears unlikely that this effect is mediated by ETRB inhibition or cross-reaction with ETRA. Instead, we present evidence that A-192621 affects glioma and melanoma viability by activating stress/DNA damage response pathways, which leads to cell cycle arrest and apoptosis. This is the first evidence linking ETRB antagonist treatment to enhanced expression of DNA damage-inducible genes

Tamoxifen Is Effective in the Treatment of Leishmania amazonensis Infections in Mice

Leishmaniasis is an antropozoonotic disease with a wide range of clinical manifestations. In humans, signs of disease vary from skin and mucosal ulcers to enlargement of internal organs such as the liver and spleen. The unicellular parasite Leishmania amazonensis is able to infect humans and cause localized or diffuse skin lesions. The treatment for this disease is difficult, as it requires prolonged and painful applications of toxic drugs that are poorly tolerated. Therefore, a key area in leishmaniasis research is the study of new therapeutic schemes and less toxic drugs. The present report is based on the investigation of tamoxifen's activity (a compound that has been in clinical use since the 1970s for the treatment of breast cancer) in the treatment of mice experimentally infected with L. amazonensis. We observed that infected mice treated with 20 mg/kg/day of tamoxifen for 15 days showed a significant clinical and parasitological response, with reduction in the size of lesions and ulcers and decreased numbers of parasites. These promising results pave the way for further testing of this drug as a new alternative in the chemotherapy of leishmaniasis

Feeding spectra and activity of the freshwater crab Trichodactylus kensleyi (Decapoda: Brachyura: Trichodactylidae) at La Plata basin

Background: In inland water systems, it is important to characterize the trophic links in order to identify the ‘trophic species’ and, from the studies of functional diversity, understand the dynamics of matter and energy in these environments. The aim of this study is to analyze the natural diet of Trichodactylus kensleyi of subtropical rainforest streams and corroborate the temporal variation in the trophic activity during day hours. Results: A total of 15 major taxonomic groups were recognized in gut contents. The index of relative importance identified the following main prey items in decreasing order of importance: vegetal remains, oligochaetes, chironomid larvae, and algae. A significant difference was found in the amount of full stomachs during day hours showing a less trophic activity at midday and afternoon. The index of relative importance values evidenced the consumption of different prey according to day moments. Results of the gut content indicate that T. kensleyi is an omnivorous crab like other trichodactylid species. Opportunistic behavior is revealed by the ingestion of organisms abundant in streams such as oligochaetes and chironomid larvae. The consumption of allochthonous plant debris shows the importance of this crab as shredder in subtropical streams. However, the effective assimilation of plant matter is yet unknown in trichodactylid crabs. Conclusions: This research provides knowledge that complements previous studies about trophic relationships of trichodactylid crabs and supported the importance of T. kensleyi in the transference of energy and matter from benthic community and riparian sources to superior trophic levels using both macro- and microfauna.Fil: Williner, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; ArgentinaFil: de Azevedo Carvalho, Debora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Collins, Pablo Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentin

Structural basis for native agonist and synthetic inhibitor recognition by the Pseudomonas aeruginosa quorum sensing regulator PqsR (MvfR)

Bacterial populations co-ordinate gene expression collectively through quorum sensing (QS), a cell-to-cell communication mechanism employing diffusible signal molecules. The LysR-type transcriptional regulator (LTTR) protein PqsR (MvfR) is a key component of alkyl-quinolone (AQ)-dependent QS in Pseudomonas aeruginosa. PqsR is activated by 2-alkyl-4-quinolones including the Pseudomonas quinolone signal (PQS; 2-heptyl-3-hydroxy-4(1H)-quinolone), its precursor 2-heptyl-4- hydroxyquinoline (HHQ) and their C9 congeners, 2-nonyl-3-hydroxy-4(1H)-quinolone (C9-PQS) and 2-nonyl-4-hydroxyquinoline (NHQ). These drive the autoinduction of AQ biosynthesis and the up-regulation of key virulence determinants as a function of bacterial population density. Consequently, PqsR constitutes a potential target for novel antibacterial agents which attenuate infection through the blockade of virulence. Here we present the crystal structures of the PqsR co-inducer binding domain (CBD) and a complex with the native agonist NHQ. We show that the structure of the PqsR CBD has an unusually large ligand-binding pocket in which a native AQ agonist is stabilized entirely by hydrophobic interactions. Through a ligand-based design strategy we synthesized and evaluated a series of 50 AQ and novel quinazolinone (QZN) analogues and measured the impact on AQ biosynthesis, virulence gene expression and biofilm development. The simple exchange of two isosteres (OH for NH2) switches a QZN agonist to an antagonist with a concomitant impact on the induction of bacterial virulence factor production. We also determined the complex crystal structure of a QZN antagonist bound to PqsR revealing a similar orientation in the ligand binding pocket to the native agonist NHQ. This structure represents the first description of an LTTR-antagonist complex. Overall these studies present novel insights into LTTR ligand binding and ligand-based drug design and provide a chemical scaffold for further anti-P. aeruginosa virulence drug development by targeting the AQ receptor PqsR

Viunalikeviruses are environmentally common agents of horizontal gene transfer in pathogens and biocontrol bacteria.

Bacteriophages have been used as natural biocontrol and therapeutic agents, but also as biotechnological tools for bacterial engineering. We showed recently that the transducing bacteriophage ϕMAM1 is a ViI-like phage and a member of the new genus, 'Viunalikevirus'. Here, we show that four additional ViI-like phages and three new environmentally isolated viunalikeviruses, all infecting plant and human pathogens, are very efficient generalised transducers capable of transducing chromosomal markers at frequencies of up to 10(-4) transductants per plaque-forming unit. We also demonstrate the interstrain transduction of plasmids and chromosomal markers, including genes involved in anabolism, genes for virulence and genes encoding secondary metabolites involved in biocontrol. We propose that all viunalikeviruses are likely to perform efficient horizontal gene transfer. Viunalikeviruses therefore represent useful agents for functional genomics and bacterial engineering, and for chemical and synthetic biology studies, but could be viewed as inappropriate choices for phage therapy.This research was supported by the EU Marie-Curie Intra-European Fellowship for Career Development (FP7- PEOPLE-2011-IEF) grant number 298003.This is the version of record of the article "Viunalikeviruses are environmentally common agents of horizontal gene transfer in pathogens and biocontrol bacteria" published in ISME Journal on August 2104 under the NPG Open Access option. The published version of record is available on the journal website at http://dx.doi.org/10.1038/ismej.2014.15

Reference Gene Selection for Quantitative Real-time PCR Normalization in Quercus suber

The use of reverse transcription quantitative PCR technology to assess gene expression levels requires an accurate normalization of data in order to avoid misinterpretation of experimental results and erroneous analyses. Despite being the focus of several transcriptomics projects, oaks, and particularly cork oak (Quercus suber), have not been investigated regarding the identification of reference genes suitable for the normalization of real-time quantitative PCR data. In this study, ten candidate reference genes (Act, CACs, EF-1α, GAPDH, His3, PsaH, Sand, PP2A, ß-Tub and Ubq) were evaluated to determine the most stable internal reference for quantitative PCR normalization in cork oak. The transcript abundance of these genes was analysed in several tissues of cork oak, including leaves, reproduction cork, and periderm from branches at different developmental stages (1-, 2-, and 3-year old) or collected in different dates (active growth period versus dormancy). The three statistical methods (geNorm, NormFinder, and CV method) used in the evaluation of the most suitable combination of reference genes identified Act and CACs as the most stable candidates when all the samples were analysed together, while ß-Tub and PsaH showed the lowest expression stability. However, when different tissues, developmental stages, and collection dates were analysed separately, the reference genes exhibited some variation in their expression levels. In this study, and for the first time, we have identified and validated reference genes in cork oak that can be used for quantification of target gene expression in different tissues and experimental conditions and will be useful as a starting point for gene expression studies in other oaks

Household exposure to pesticides and bladder exstrophy in a newborn baby boy: a case report and review of the literature

© 2009 Martin et al; licensee Cases Network Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Farseer-NMR: automatic treatment, analysis and plotting of large, multi-variable NMR data

We present Farseer-NMR (https://git.io/vAueU), a software package to treat, evaluate and combine NMR spectroscopic data from sets of protein-derived peaklists covering a range of experimental conditions. The combined advances in NMR and molecular biology enable the study of complex biomolecular systems such as flexible proteins or large multibody complexes, which display a strong and functionally relevant response to their environmental conditions, e.g. the presence of ligands, site-directed mutations, post translational modifications, molecular crowders or the chemical composition of the solution. These advances have created a growing need to analyse those systems’ responses to multiple variables. The combined analysis of NMR peaklists from large and multivariable datasets has become a new bottleneck in the NMR analysis pipeline, whereby information-rich NMR-derived parameters have to be manually generated, which can be tedious, repetitive and prone to human error, or even unfeasible for very large datasets. There is a persistent gap in the development and distribution of software focused on peaklist treatment, analysis and representation, and specifically able to handle large multivariable datasets, which are becoming more commonplace. In this regard, Farseer-NMR aims to close this longstanding gap in the automated NMR user pipeline and, altogether, reduce the time burden of analysis of large sets of peaklists from days/weeks to seconds/minutes. We have implemented some of the most common, as well as new, routines for calculation of NMR parameters and several publication-quality plotting templates to improve NMR data representation. Farseer-NMR has been written entirely in Python and its modular code base enables facile extension